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authorroot <root@nuedel.(none)>2011-09-26 11:23:06 +0200
committerHarald Welte <laforge@gnumonks.org>2011-10-10 08:38:58 +0200
commitaf48bed556079313074d8a2ea132fd689af8a100 (patch)
treec027cc6e8f93257ddcda20c4f794d83760e443d0
parent8a996b4844f8f89c16ce5062c74942d57f6f73b4 (diff)
Split of LAPDm into a core part and a GSM specific part
Instead of mixing together the GSM layer 1 interface and RSL interface with the implementation of LAPD, the core function of LAPD is now extracted from LAPDm. The core implementation is now in lapd_core.c and lapd_core.h respectively. The lapd_core.c implements exactly one datalink instance for one SAP. The surrounding implementation "lapdm.c" codes/decodes the layer 2 headers and handles multiplexing and datalink instances, as well as translates primitives from/to RSL layer. lapd_core.c can now be used for other LAPD implementations. (ISDN/ABIS)
-rw-r--r--include/osmocom/gsm/Makefile.am2
-rw-r--r--include/osmocom/gsm/lapd_core.h171
-rw-r--r--include/osmocom/gsm/lapdm.h51
-rw-r--r--src/gsm/Makefile.am2
-rw-r--r--src/gsm/lapd_core.c2128
-rw-r--r--src/gsm/lapdm.c1947
6 files changed, 2631 insertions, 1670 deletions
diff --git a/include/osmocom/gsm/Makefile.am b/include/osmocom/gsm/Makefile.am
index 90f19bc5..5971d0c5 100644
--- a/include/osmocom/gsm/Makefile.am
+++ b/include/osmocom/gsm/Makefile.am
@@ -1,6 +1,6 @@
osmogsm_HEADERS = a5.h comp128.h gsm0808.h gsm48_ie.h mncc.h rxlev_stat.h \
gsm0480.h gsm48.h gsm_utils.h rsl.h tlv.h abis_nm.h \
- sysinfo.h prim.h gsm0502.h lapdm.h
+ sysinfo.h prim.h gsm0502.h lapd_core.h lapdm.h
SUBDIRS = protocol
diff --git a/include/osmocom/gsm/lapd_core.h b/include/osmocom/gsm/lapd_core.h
new file mode 100644
index 00000000..0f4e8899
--- /dev/null
+++ b/include/osmocom/gsm/lapd_core.h
@@ -0,0 +1,171 @@
+#ifndef _OSMOCOM_LAPD_H
+#define _OSMOCOM_LAPD_H
+
+#include <stdint.h>
+
+#include <osmocom/core/timer.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/gsm/prim.h>
+
+/*! \defgroup lapd LAPD implementation common part
+ * @{
+ */
+
+/*! \file lapd.h */
+
+/* primitive related sutff */
+
+/*! \brief LAPD related primitives (L2<->L3 SAP)*/
+enum osmo_dl_prim {
+ PRIM_DL_UNIT_DATA, /*!< \brief DL-UNIT-DATA */
+ PRIM_DL_DATA, /*!< \brief DL-DATA */
+ PRIM_DL_EST, /*!< \brief DL-ESTABLISH */
+ PRIM_DL_REL, /*!< \brief DL-RLEEASE */
+ PRIM_DL_SUSP, /*!< \brief DL-SUSPEND */
+ PRIM_DL_RES, /*!< \brief DL-RESUME */
+ PRIM_DL_RECON, /*!< \brief DL-RECONNECT */
+ PRIM_MDL_ERROR, /*!< \brief MDL-ERROR */
+};
+
+/* Uses the same values as RLL, so no conversion for GSM is required. */
+#define MDL_CAUSE_T200_EXPIRED 0x01
+#define MDL_CAUSE_REEST_REQ 0x02
+#define MDL_CAUSE_UNSOL_UA_RESP 0x03
+#define MDL_CAUSE_UNSOL_DM_RESP 0x04
+#define MDL_CAUSE_UNSOL_DM_RESP_MF 0x05
+#define MDL_CAUSE_UNSOL_SPRV_RESP 0x06
+#define MDL_CAUSE_SEQ_ERR 0x07
+#define MDL_CAUSE_UFRM_INC_PARAM 0x08
+#define MDL_CAUSE_SFRM_INC_PARAM 0x09
+#define MDL_CAUSE_IFRM_INC_MBITS 0x0a
+#define MDL_CAUSE_IFRM_INC_LEN 0x0b
+#define MDL_CAUSE_FRM_UNIMPL 0x0c
+#define MDL_CAUSE_SABM_MF 0x0d
+#define MDL_CAUSE_SABM_INFO_NOTALL 0x0e
+#define MDL_CAUSE_FRMR 0x0f
+
+/*! \brief for MDL-ERROR.ind */
+struct mdl_error_ind_param {
+ uint8_t cause; /*!< \brief generic cause value */
+};
+
+/*! \brief for DL-REL.req */
+struct dl_rel_req_param {
+ uint8_t mode; /*!< \brief release mode */
+};
+
+/*! \brief primitive header for LAPD DL-SAP primitives */
+struct osmo_dlsap_prim {
+ struct osmo_prim_hdr oph; /*!< \brief generic primitive header */
+ union {
+ struct mdl_error_ind_param error_ind;
+ struct dl_rel_req_param rel_req;
+ } u; /*!< \brief request-specific data */
+};
+
+/*! \brief LAPD mode/role */
+enum lapd_mode {
+ LAPD_MODE_USER, /*!< \brief behave like user */
+ LAPD_MODE_NETWORK, /*!< \brief behave like network */
+};
+
+/*! \brief LAPD state (Figure B.2/Q.921)*/
+enum lapd_state {
+ LAPD_STATE_NULL = 0,
+ LAPD_STATE_TEI_UNASS,
+ LAPD_STATE_ASS_TEI_WAIT,
+ LAPD_STATE_EST_TEI_WAIT,
+ LAPD_STATE_IDLE,
+ LAPD_STATE_SABM_SENT,
+ LAPD_STATE_DISC_SENT,
+ LAPD_STATE_MF_EST,
+ LAPD_STATE_TIMER_RECOV,
+};
+
+/*! \brief LAPD message format (I / S / U) */
+enum lapd_format {
+ LAPD_FORM_UKN = 0,
+ LAPD_FORM_I,
+ LAPD_FORM_S,
+ LAPD_FORM_U,
+};
+
+/*! \brief LAPD message context */
+struct lapd_msg_ctx {
+ struct lapd_datalink *dl;
+ int n201;
+ /* address */
+ uint8_t cr;
+ uint8_t sapi;
+ uint8_t tei;
+ uint8_t lpd;
+ /* control */
+ uint8_t format;
+ uint8_t p_f; /* poll / final bit */
+ uint8_t n_send;
+ uint8_t n_recv;
+ uint8_t s_u; /* S or repectivly U function bits */
+ /* length */
+ int length;
+ uint8_t more;
+};
+
+struct lapd_cr_ent {
+ uint8_t cmd;
+ uint8_t resp;
+};
+
+struct lapd_history {
+ struct msgb *msg; /* message to be sent / NULL, if histoy is empty */
+ int more; /* if message is fragmented */
+};
+
+/*! \brief LAPD datalink */
+struct lapd_datalink {
+ int (*send_dlsap)(struct osmo_dlsap_prim *dp,
+ struct lapd_msg_ctx *lctx);
+ int (*send_ph_data_req)(struct lapd_msg_ctx *lctx, struct msgb *msg);
+ struct {
+ /*! \brief filled-in once we set the lapd_mode above */
+ struct lapd_cr_ent loc2rem;
+ struct lapd_cr_ent rem2loc;
+ } cr;
+ enum lapd_mode mode; /*!< \brief current mode of link */
+ int use_sabme; /*!< \brief use SABME instead of SABM */
+ int reestablish; /*!< \brief enable reestablish support */
+ int n200, n200_est_rel; /*!< \brief number of retranmissions */
+ struct lapd_msg_ctx lctx; /*!< \brief LAPD context */
+ int maxf; /*!< \brief maximum frame size (after defragmentation) */
+ uint8_t k; /*!< \brief maximum number of unacknowledged frames */
+ uint8_t v_range; /*!< \brief range of sequence numbers */
+ uint8_t v_send; /*!< \brief seq nr of next I frame to be transmitted */
+ uint8_t v_ack; /*!< \brief last frame ACKed by peer */
+ uint8_t v_recv; /*!< \brief seq nr of next I frame expected to be received */
+ uint32_t state; /*!< \brief LAPD state (\ref lapd_state) */
+ int seq_err_cond; /*!< \brief condition of sequence error */
+ uint8_t own_busy; /*!< \brief receiver busy on our side */
+ uint8_t peer_busy; /*!< \brief receiver busy on remote side */
+ int t200_sec, t200_usec; /*!< \brief retry timer (default 1 sec) */
+ int t203_sec, t203_usec; /*!< \brief retry timer (default 10 secs) */
+ struct osmo_timer_list t200; /*!< \brief T200 timer */
+ struct osmo_timer_list t203; /*!< \brief T203 timer */
+ uint8_t retrans_ctr; /*!< \brief re-transmission counter */
+ struct llist_head tx_queue; /*!< \brief frames to L1 */
+ struct llist_head send_queue; /*!< \brief frames from L3 */
+ struct msgb *send_buffer; /*!< \brief current frame transmitting */
+ int send_out; /*!< \brief how much was sent from send_buffer */
+ struct lapd_history *tx_hist; /*!< \brief tx history structure array */
+ uint8_t range_hist; /*!< \brief range of history buffer 2..2^n */
+ struct msgb *rcv_buffer; /*!< \brief buffer to assemble the received message */
+ struct msgb *cont_res; /*!< \brief buffer to store content resolution data on network side, to detect multiple phones on same channel */
+};
+
+void lapd_dl_init(struct lapd_datalink *dl, uint8_t k, uint8_t v_range,
+ int maxf);
+void lapd_dl_exit(struct lapd_datalink *dl);
+void lapd_dl_reset(struct lapd_datalink *dl);
+int lapd_set_mode(struct lapd_datalink *dl, enum lapd_mode mode);
+int lapd_ph_data_ind(struct msgb *msg, struct lapd_msg_ctx *lctx);
+int lapd_recv_dlsap(struct osmo_dlsap_prim *dp, struct lapd_msg_ctx *lctx);
+
+#endif /* _OSMOCOM_LAPD_H */
diff --git a/include/osmocom/gsm/lapdm.h b/include/osmocom/gsm/lapdm.h
index b71feef1..cc9c63fe 100644
--- a/include/osmocom/gsm/lapdm.h
+++ b/include/osmocom/gsm/lapdm.h
@@ -1,11 +1,7 @@
#ifndef _OSMOCOM_LAPDM_H
#define _OSMOCOM_LAPDM_H
-#include <stdint.h>
-
-#include <osmocom/core/timer.h>
-#include <osmocom/core/msgb.h>
-#include <osmocom/gsm/prim.h>
+#include <osmocom/gsm/lapd_core.h>
/*! \defgroup lapdm LAPDm implementation according to GSM TS 04.06
* @{
@@ -15,7 +11,7 @@
/* primitive related sutff */
-/*! \brief LAPDm related primitives */
+/*! \brief LAPDm related primitives (L1<->L2 SAP) */
enum osmo_ph_prim {
PRIM_PH_DATA, /*!< \brief PH-DATA */
PRIM_PH_RACH, /*!< \brief PH-RANDOM_ACCESS */
@@ -68,52 +64,22 @@ enum lapdm_mode {
LAPDM_MODE_BTS, /*!< \brief behave like a BTS (network) */
};
-/*! \brief LAPDm state */
-enum lapdm_state {
- LAPDm_STATE_NULL = 0,
- LAPDm_STATE_IDLE,
- LAPDm_STATE_SABM_SENT,
- LAPDm_STATE_MF_EST,
- LAPDm_STATE_TIMER_RECOV,
- LAPDm_STATE_DISC_SENT,
-};
-
struct lapdm_entity;
/*! \brief LAPDm message context */
struct lapdm_msg_ctx {
struct lapdm_datalink *dl;
int lapdm_fmt;
- uint8_t n201;
uint8_t chan_nr;
uint8_t link_id;
- uint8_t addr;
- uint8_t ctrl;
uint8_t ta_ind;
uint8_t tx_power_ind;
};
/*! \brief LAPDm datalink like TS 04.06 / Section 3.5.2 */
struct lapdm_datalink {
- uint8_t V_send; /*!< \brief seq nr of next I frame to be transmitted */
- uint8_t V_ack; /*!< \brief last frame ACKed by peer */
- uint8_t N_send; /*!< \brief ? set to V_send at Tx time*/
- uint8_t V_recv; /*!< \brief seq nr of next I frame expected to be received */
- uint8_t N_recv; /*!< \brief expected send seq nr of the next received I frame */
- uint32_t state; /*!< \brief LAPDm state (\ref lapdm_state) */
- int seq_err_cond; /*!< \brief condition of sequence error */
- uint8_t own_busy; /*!< \brief receiver busy on our side */
- uint8_t peer_busy; /*!< \brief receiver busy on remote side */
- struct osmo_timer_list t200; /*!< \brief T200 timer */
- uint8_t retrans_ctr; /*!< \brief re-transmission counter */
- struct llist_head send_queue; /*!< \brief frames from L3 */
- struct msgb *send_buffer; /*!< \brief current frame transmitting */
- int send_out; /*!< \brief how much was sent from send_buffer */
- uint8_t tx_hist[8][200]; /*!< \brief tx history buffer */
- int tx_length[8]; /*!< \brief length in history buffer */
- struct llist_head tx_queue; /*!< \brief frames to L1 */
+ struct lapd_datalink dl; /* \brief common LAPD */
struct lapdm_msg_ctx mctx; /*!< \brief context of established connection */
- struct msgb *rcv_buffer; /*!< \brief buffer to assemble the received message */
struct lapdm_entity *entity; /*!< \brief LAPDm entity we are part of */
};
@@ -127,11 +93,6 @@ enum lapdm_dl_sapi {
typedef int (*lapdm_cb_t)(struct msgb *msg, struct lapdm_entity *le, void *ctx);
-struct lapdm_cr_ent {
- uint8_t cmd;
- uint8_t resp;
-};
-
#define LAPDM_ENT_F_EMPTY_FRAME 0x0001
#define LAPDM_ENT_F_POLLING_ONLY 0x0002
@@ -144,12 +105,6 @@ struct lapdm_entity {
enum lapdm_mode mode; /*!< \brief are we in BTS mode or MS mode */
unsigned int flags;
- struct {
- /*! \brief filled-in once we set the lapdm_mode above */
- struct lapdm_cr_ent loc2rem;
- struct lapdm_cr_ent rem2loc;
- } cr;
-
void *l1_ctx; /*!< \brief context for layer1 instance */
void *l3_ctx; /*!< \brief context for layer3 instance */
diff --git a/src/gsm/Makefile.am b/src/gsm/Makefile.am
index f5e46769..c0f72b3f 100644
--- a/src/gsm/Makefile.am
+++ b/src/gsm/Makefile.am
@@ -10,6 +10,6 @@ lib_LTLIBRARIES = libosmogsm.la
libosmogsm_la_SOURCES = a5.c rxlev_stat.c tlv_parser.c comp128.c gsm_utils.c \
rsl.c gsm48.c gsm48_ie.c gsm0808.c sysinfo.c \
gprs_cipher_core.c gsm0480.c abis_nm.c gsm0502.c \
- lapdm.c
+ lapd_core.c lapdm.c
libosmogsm_la_LDFLAGS = -version-info $(LIBVERSION)
libosmogsm_la_LIBADD = $(top_builddir)/src/libosmocore.la
diff --git a/src/gsm/lapd_core.c b/src/gsm/lapd_core.c
new file mode 100644
index 00000000..f7408e54
--- /dev/null
+++ b/src/gsm/lapd_core.c
@@ -0,0 +1,2128 @@
+/* LAPD core implementation */
+
+/* (C) 2010-2011 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2010-2011 by Andreas Eversberg <jolly@eversberg.eu>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+/*! \addtogroup lapd
+ * @{
+ */
+
+/*! \file lapd.c */
+
+/*!
+ * Notes on Buffering: rcv_buffer, tx_queue, tx_hist, send_buffer, send_queue
+ *
+ * RX data is stored in the rcv_buffer (pointer). If the message is complete, it
+ * is removed from rcv_buffer pointer and forwarded to L3. If the RX data is
+ * received while there is an incomplete rcv_buffer, it is appended to it.
+ *
+ * TX data is stored in the send_queue first. When transmitting a frame,
+ * the first message in the send_queue is moved to the send_buffer. There it
+ * resides until all fragments are acknowledged. Fragments to be sent by I
+ * frames are stored in the tx_hist buffer for resend, if required. Also the
+ * current fragment is copied into the tx_queue. There it resides until it is
+ * forwarded to layer 1.
+ *
+ * In case we have SAPI 0, we only have a window size of 1, so the unack-
+ * nowledged message resides always in the send_buffer. In case of a suspend,
+ * it can be written back to the first position of the send_queue.
+ *
+ * The layer 1 normally sends a PH-READY-TO-SEND. But because we use
+ * asynchronous transfer between layer 1 and layer 2 (serial link), we must
+ * send a frame before layer 1 reaches the right timeslot to send it. So we
+ * move the tx_queue to layer 1 when there is not already a pending frame, and
+ * wait until acknowledge after the frame has been sent. If we receive an
+ * acknowledge, we can send the next frame from the buffer, if any.
+ *
+ * The moving of tx_queue to layer 1 may also trigger T200, if desired. Also it
+ * will trigger next I frame, if possible.
+ *
+ * T203 is optional. It will be stated when entering MF EST state. It will also
+ * be started when I or S frame is received in that state . It will be
+ * restarted in the lapd_acknowledge() function, in case outstanding frames
+ * will not trigger T200. It will be stoped, when T200 is started in MF EST
+ * state. It will also be stoped when leaving MF EST state.
+ *
+ */
+
+/* Enable this to test content resolution on network side:
+ * - The first SABM is received, UA is dropped.
+ * - The phone repeats SABM, but it's content is wrong, so it is ignored
+ * - The phone repeats SABM again, content is right, so UA is sent.
+ */
+//#define TEST_CONTENT_RESOLUTION_NETWORK
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+#include <arpa/inet.h>
+
+#include <osmocom/core/logging.h>
+#include <osmocom/core/timer.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/gsm/lapd_core.h>
+
+/* TS 04.06 Table 4 / Section 3.8.1 */
+#define LAPD_U_SABM 0x7
+#define LAPD_U_SABME 0xf
+#define LAPD_U_DM 0x3
+#define LAPD_U_UI 0x0
+#define LAPD_U_DISC 0x8
+#define LAPD_U_UA 0xC
+#define LAPD_U_FRMR 0x11
+
+#define LAPD_S_RR 0x0
+#define LAPD_S_RNR 0x1
+#define LAPD_S_REJ 0x2
+
+#define CR_USER2NET_CMD 0
+#define CR_USER2NET_RESP 1
+#define CR_NET2USER_CMD 1
+#define CR_NET2USER_RESP 0
+
+#define LAPD_HEADROOM 56
+
+#define SBIT(a) (1 << a)
+#define ALL_STATES 0xffffffff
+
+/* UTILITY FUNCTIONS */
+
+struct msgb *lapd_msgb_alloc(int length, const char *name)
+{
+ /* adding space for padding, FIXME: add as an option */
+ if (length < 21)
+ length = 21;
+ return msgb_alloc_headroom(length + LAPD_HEADROOM, LAPD_HEADROOM, name);
+}
+
+static inline uint8_t do_mod(uint8_t x, uint8_t m)
+{
+ return x & (m - 1);
+}
+
+static inline uint8_t inc_mod(uint8_t x, uint8_t m)
+{
+ return (x + 1) & (m - 1);
+}
+
+static inline uint8_t add_mod(uint8_t x, uint8_t y, uint8_t m)
+{
+ return (x + y) & (m - 1);
+}
+
+static inline uint8_t sub_mod(uint8_t x, uint8_t y, uint8_t m)
+{
+ return (x - y) & (m - 1); /* handle negative results correctly */
+}
+
+static void lapd_dl_flush_send(struct lapd_datalink *dl)
+{
+ struct msgb *msg;
+
+ /* Flush send-queue */
+ while ((msg = msgb_dequeue(&dl->send_queue)))
+ msgb_free(msg);
+
+ /* Clear send-buffer */
+ if (dl->send_buffer) {
+ msgb_free(dl->send_buffer);
+ dl->send_buffer = NULL;
+ }
+}
+
+static void lapd_dl_flush_hist(struct lapd_datalink *dl)
+{
+ unsigned int i;
+
+ for (i = 0; i < dl->range_hist; i++) {
+ if (dl->tx_hist[i].msg) {
+ msgb_free(dl->tx_hist[i].msg);
+ dl->tx_hist[i].msg = NULL;
+ }
+ }
+}
+
+static void lapd_dl_flush_tx(struct lapd_datalink *dl)
+{
+ struct msgb *msg;
+
+ while ((msg = msgb_dequeue(&dl->tx_queue)))
+ msgb_free(msg);
+ lapd_dl_flush_hist(dl);
+}
+
+/* Figure B.2/Q.921 */
+const char *lapd_state_names[] = {
+ "LAPD_STATE_NULL",
+ "LAPD_STATE_TEI_UNASS",
+ "LAPD_STATE_ASS_TEI_WAIT",
+ "LAPD_STATE_EST_TEI_WAIT",
+ "LAPD_STATE_IDLE",
+ "LAPD_STATE_SABM_SENT",
+ "LAPD_STATE_DISC_SENT",
+ "LAPD_STATE_MF_EST",
+ "LAPD_STATE_TIMER_RECOV",
+
+};
+
+static void lapd_dl_newstate(struct lapd_datalink *dl, uint32_t state)
+{
+ LOGP(DLLAPD, LOGL_INFO, "new state %s -> %s\n",
+ lapd_state_names[dl->state], lapd_state_names[state]);
+
+ if (state != LAPD_STATE_MF_EST && dl->state == LAPD_STATE_MF_EST) {
+ /* stop T203 on leaving MF EST state, if running */
+ if (osmo_timer_pending(&dl->t203)) {
+ LOGP(DLLAPD, LOGL_INFO, "stop T203\n");
+ osmo_timer_del(&dl->t203);
+ }
+ /* remove content res. (network side) on leaving MF EST state */
+ if (dl->cont_res) {
+ msgb_free(dl->cont_res);
+ dl->cont_res = NULL;
+ }
+ }
+
+ /* start T203 on entering MF EST state, if enabled */
+ if ((dl->t203_sec || dl->t203_usec)
+ && state == LAPD_STATE_MF_EST && dl->state != LAPD_STATE_MF_EST) {
+ LOGP(DLLAPD, LOGL_INFO, "start T203\n");
+ osmo_timer_schedule(&dl->t203, dl->t203_sec, dl->t203_usec);
+ }
+
+ dl->state = state;
+}
+
+static void lapd_t200_cb(void *data);
+static void lapd_t203_cb(void *data);
+static int lapd_send_i(struct lapd_msg_ctx *lctx, int line);
+static int lapd_est_req(struct osmo_dlsap_prim *dp, struct lapd_msg_ctx *lctx);
+
+static void *tall_lapd_ctx = NULL;
+
+/* init datalink instance and allocate history */
+void lapd_dl_init(struct lapd_datalink *dl, uint8_t k, uint8_t v_range,
+ int maxf)
+{
+ int m;
+
+ memset(dl, 0, sizeof(*dl));
+ INIT_LLIST_HEAD(&dl->send_queue);
+ INIT_LLIST_HEAD(&dl->tx_queue);
+ dl->reestablish = 1;
+ dl->n200_est_rel = 3;
+ dl->n200 = 3;
+ dl->t200_sec = 1;
+ dl->t200_usec = 0;
+ dl->t200.data = dl;
+ dl->t200.cb = &lapd_t200_cb;
+ dl->t203_sec = 10;
+ dl->t203_usec = 0;
+ dl->t203.data = dl;
+ dl->t203.cb = &lapd_t203_cb;
+ dl->maxf = maxf;
+ if (k > v_range - 1)
+ k = v_range - 1;
+ dl->k = k;
+ dl->v_range = v_range;
+
+ /* Calculate modulo for history array:
+ * - The history range must be at least k+1.
+ * - The history range must be 2^x, where x is as low as possible.
+ */
+ k++;
+ for (m = 0x80; m; m >>= 1) {
+ if ((m & k)) {
+ if (k > m)
+ m <<= 1;
+ dl->range_hist = m;
+ break;
+ }
+ }
+
+ LOGP(DLLAPD, LOGL_INFO, "Init DL layer: sequence range = %d, k = %d, "
+ "history range = %d\n", dl->v_range, dl->k, dl->range_hist);
+
+ lapd_dl_newstate(dl, LAPD_STATE_IDLE);
+
+ if (!tall_lapd_ctx)
+ tall_lapd_ctx = talloc_named_const(NULL, 1, "lapd context");
+ dl->tx_hist = (struct lapd_history *) talloc_zero_array(tall_lapd_ctx,
+ struct log_info, dl->range_hist);
+}
+
+/* reset to IDLE state */
+void lapd_dl_reset(struct lapd_datalink *dl)
+{
+ if (dl->state == LAPD_STATE_IDLE)
+ return;
+ LOGP(DLLAPD, LOGL_INFO, "Resetting LAPDm instance\n");
+ /* enter idle state (and remove eventual cont_res) */
+ lapd_dl_newstate(dl, LAPD_STATE_IDLE);
+ /* flush buffer */
+ lapd_dl_flush_tx(dl);
+ lapd_dl_flush_send(dl);
+ /* Discard partly received L3 message */
+ if (dl->rcv_buffer) {
+ msgb_free(dl->rcv_buffer);
+ dl->rcv_buffer = NULL;
+ }
+ /* reset Timers */
+ osmo_timer_del(&dl->t200);
+ osmo_timer_del(&dl->t203);
+}
+
+/* reset and de-allocate history buffer */
+void lapd_dl_exit(struct lapd_datalink *dl)
+{
+ /* free all ressources except history buffer */
+ lapd_dl_reset(dl);
+ /* free history buffer list */
+ talloc_free(dl->tx_hist);
+}
+
+/*! \brief Set the \ref lapdm_mode of a LAPDm entity */
+int lapd_set_mode(struct lapd_datalink *dl, enum lapd_mode mode)
+{
+ switch (mode) {
+ case LAPD_MODE_USER:
+ dl->cr.loc2rem.cmd = CR_USER2NET_CMD;
+ dl->cr.loc2rem.resp = CR_USER2NET_RESP;
+ dl->cr.rem2loc.cmd = CR_NET2USER_CMD;
+ dl->cr.rem2loc.resp = CR_NET2USER_RESP;
+ break;
+ case LAPD_MODE_NETWORK:
+ dl->cr.loc2rem.cmd = CR_NET2USER_CMD;
+ dl->cr.loc2rem.resp = CR_NET2USER_RESP;
+ dl->cr.rem2loc.cmd = CR_USER2NET_CMD;
+ dl->cr.rem2loc.resp = CR_USER2NET_RESP;
+ break;
+ default:
+ return -EINVAL;
+ }
+ dl->mode = mode;
+
+ return 0;
+}
+
+/* send DL message with optional msgb */
+static int send_dl_l3(uint8_t prim, uint8_t op, struct lapd_msg_ctx *lctx,
+ struct msgb *msg)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ struct osmo_dlsap_prim dp;
+
+ osmo_prim_init(&dp.oph, 0, prim, op, msg);
+ return dl->send_dlsap(&dp, lctx);
+}
+
+/* send simple DL message */
+static inline int send_dl_simple(uint8_t prim, uint8_t op,
+ struct lapd_msg_ctx *lctx)
+{
+ struct msgb *msg = lapd_msgb_alloc(0, "DUMMY");
+
+ return send_dl_l3(prim, op, lctx, msg);
+}
+
+/* send MDL-ERROR INDICATION */
+static int mdl_error(uint8_t cause, struct lapd_msg_ctx *lctx)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ struct osmo_dlsap_prim dp;
+
+ LOGP(DLLAPD, LOGL_NOTICE, "sending MDL-ERROR-IND cause %d\n",
+ cause);
+ osmo_prim_init(&dp.oph, 0, PRIM_MDL_ERROR, PRIM_OP_INDICATION, NULL);
+ dp.u.error_ind.cause = cause;
+ return dl->send_dlsap(&dp, lctx);
+}
+
+/* send UA response */
+static int lapd_send_ua(struct lapd_msg_ctx *lctx, uint8_t len, uint8_t *data)
+{
+ struct msgb *msg = lapd_msgb_alloc(len, "LAPD UA");
+ struct lapd_msg_ctx nctx;
+ struct lapd_datalink *dl = lctx->dl;
+
+ memcpy(&nctx, lctx, sizeof(nctx));
+ msg->l3h = msgb_put(msg, len);
+ if (len)
+ memcpy(msg->l3h, data, len);
+ /* keep nctx.ldp */
+ /* keep nctx.sapi */
+ /* keep nctx.tei */
+ nctx.cr = dl->cr.loc2rem.resp;
+ nctx.format = LAPD_FORM_U;
+ nctx.s_u = LAPD_U_UA;
+ /* keep nctx.p_f */
+ nctx.length = len;
+ nctx.more = 0;
+
+ return dl->send_ph_data_req(&nctx, msg);
+}
+
+/* send DM response */
+static int lapd_send_dm(struct lapd_msg_ctx *lctx)
+{
+ struct msgb *msg = lapd_msgb_alloc(0, "LAPD DM");
+ struct lapd_msg_ctx nctx;
+ struct lapd_datalink *dl = lctx->dl;
+
+ memcpy(&nctx, lctx, sizeof(nctx));
+ /* keep nctx.ldp */
+ /* keep nctx.sapi */
+ /* keep nctx.tei */
+ nctx.cr = dl->cr.loc2rem.resp;
+ nctx.format = LAPD_FORM_U;
+ nctx.s_u = LAPD_U_DM;
+ /* keep nctx.p_f */
+ nctx.length = 0;
+ nctx.more = 0;
+
+ return dl->send_ph_data_req(&nctx, msg);
+}
+
+/* send RR response / command */
+static int lapd_send_rr(struct lapd_msg_ctx *lctx, uint8_t f_bit, uint8_t cmd)
+{
+ struct msgb *msg = lapd_msgb_alloc(0, "LAPD RR");
+ struct lapd_msg_ctx nctx;
+ struct lapd_datalink *dl = lctx->dl;
+
+ memcpy(&nctx, lctx, sizeof(nctx));
+ /* keep nctx.ldp */
+ /* keep nctx.sapi */
+ /* keep nctx.tei */
+ nctx.cr = (cmd) ? dl->cr.loc2rem.cmd : dl->cr.loc2rem.resp;
+ nctx.format = LAPD_FORM_S;
+ nctx.s_u = LAPD_S_RR;
+ nctx.p_f = f_bit;
+ nctx.n_recv = dl->v_recv;
+ nctx.length = 0;
+ nctx.more = 0;
+
+ return dl->send_ph_data_req(&nctx, msg);
+}
+
+/* send RNR response / command */
+static int lapd_send_rnr(struct lapd_msg_ctx *lctx, uint8_t f_bit, uint8_t cmd)
+{
+ struct msgb *msg = lapd_msgb_alloc(0, "LAPD RNR");
+ struct lapd_msg_ctx nctx;
+ struct lapd_datalink *dl = lctx->dl;
+
+ memcpy(&nctx, lctx, sizeof(nctx));
+ /* keep nctx.ldp */
+ /* keep nctx.sapi */
+ /* keep nctx.tei */
+ nctx.cr = (cmd) ? dl->cr.loc2rem.cmd : dl->cr.loc2rem.resp;
+ nctx.format = LAPD_FORM_S;
+ nctx.s_u = LAPD_S_RNR;
+ nctx.p_f = f_bit;
+ nctx.n_recv = dl->v_recv;
+ nctx.length = 0;
+ nctx.more = 0;
+
+ return dl->send_ph_data_req(&nctx, msg);
+}
+
+/* send REJ response */
+static int lapd_send_rej(struct lapd_msg_ctx *lctx, uint8_t f_bit)
+{
+ struct msgb *msg = lapd_msgb_alloc(0, "LAPD REJ");
+ struct lapd_msg_ctx nctx;
+ struct lapd_datalink *dl = lctx->dl;
+
+ memcpy(&nctx, lctx, sizeof(nctx));
+ /* keep nctx.ldp */
+ /* keep nctx.sapi */
+ /* keep nctx.tei */
+ nctx.cr = dl->cr.loc2rem.resp;
+ nctx.format = LAPD_FORM_S;
+ nctx.s_u = LAPD_S_REJ;
+ nctx.p_f = f_bit;
+ nctx.n_recv = dl->v_recv;
+ nctx.length = 0;
+ nctx.more = 0;
+
+ return dl->send_ph_data_req(&nctx, msg);
+}
+
+/* resend SABM or DISC message */
+static int lapd_send_resend(struct lapd_datalink *dl)
+{
+ struct msgb *msg;
+ uint8_t h = do_mod(dl->v_send, dl->range_hist);
+ int length = dl->tx_hist[h].msg->len;
+ struct lapd_msg_ctx nctx;
+
+ /* assemble message */
+ memcpy(&nctx, &dl->lctx, sizeof(nctx));
+ /* keep nctx.ldp */
+ /* keep nctx.sapi */
+ /* keep nctx.tei */
+ nctx.cr = dl->cr.loc2rem.cmd;
+ nctx.format = LAPD_FORM_U;
+ if (dl->state == LAPD_STATE_SABM_SENT)
+ nctx.s_u = (dl->use_sabme) ? LAPD_U_SABME : LAPD_U_SABM;
+ else
+ nctx.s_u = LAPD_U_DISC;
+ nctx.p_f = 1;
+ nctx.length = length;
+ nctx.more = 0;
+
+ /* Resend SABM/DISC from tx_hist */
+ msg = lapd_msgb_alloc(length, "LAPD resend");
+ msg->l3h = msgb_put(msg, length);
+ if (length)
+ memcpy(msg->l3h, dl->tx_hist[h].msg->data, length);
+
+ return dl->send_ph_data_req(&nctx, msg);
+}
+
+/* reestablish link */
+static int lapd_reestablish(struct lapd_datalink *dl)
+{
+ struct osmo_dlsap_prim dp;
+ struct msgb *msg;
+
+ msg = lapd_msgb_alloc(0, "DUMMY");
+ osmo_prim_init(&dp.oph, 0, PRIM_DL_EST, PRIM_OP_REQUEST, msg);
+
+ return lapd_est_req(&dp, &dl->lctx);
+}
+
+/* Timer callback on T200 expiry */
+static void lapd_t200_cb(void *data)
+{
+ struct lapd_datalink *dl = data;
+
+ LOGP(DLLAPD, LOGL_INFO, "lapd_t200_cb(%p) state=%d\n", dl,
+ (int) dl->state);
+
+ switch (dl->state) {
+ case LAPD_STATE_SABM_SENT:
+ /* 5.4.1.3 */
+ if (dl->retrans_ctr + 1 >= dl->n200_est_rel + 1) {
+ /* send RELEASE INDICATION to L3 */
+ send_dl_simple(PRIM_DL_REL, PRIM_OP_INDICATION,
+ &dl->lctx);
+ /* send MDL ERROR INIDCATION to L3 */
+ mdl_error(MDL_CAUSE_T200_EXPIRED, &dl->lctx);
+ /* flush tx and send buffers */
+ lapd_dl_flush_tx(dl);
+ lapd_dl_flush_send(dl);
+ /* go back to idle state */
+ lapd_dl_newstate(dl, LAPD_STATE_IDLE);
+ /* NOTE: we must not change any other states or buffers
+ * and queues, since we may reconnect after handover
+ * failure. the buffered messages is replaced there */
+ break;
+ }
+ /* retransmit SABM command */
+ lapd_send_resend(dl);
+ /* increment re-transmission counter */
+ dl->retrans_ctr++;
+ /* restart T200 (PH-READY-TO-SEND) */
+ osmo_timer_schedule(&dl->t200, dl->t200_sec, dl->t200_usec);
+ break;
+ case LAPD_STATE_DISC_SENT:
+ /* 5.4.4.3 */
+ if (dl->retrans_ctr + 1 >= dl->n200_est_rel + 1) {
+ /* send RELEASE INDICATION to L3 */
+ send_dl_simple(PRIM_DL_REL, PRIM_OP_CONFIRM, &dl->lctx);
+ /* send MDL ERROR INIDCATION to L3 */
+ mdl_error(MDL_CAUSE_T200_EXPIRED, &dl->lctx);
+ /* flush tx and send buffers */
+ lapd_dl_flush_tx(dl);
+ lapd_dl_flush_send(dl);
+ /* go back to idle state */
+ lapd_dl_newstate(dl, LAPD_STATE_IDLE);
+ /* NOTE: we must not change any other states or buffers
+ * and queues, since we may reconnect after handover
+ * failure. the buffered messages is replaced there */
+ break;
+ }
+ /* retransmit DISC command */
+ lapd_send_resend(dl);
+ /* increment re-transmission counter */
+ dl->retrans_ctr++;
+ /* restart T200 (PH-READY-TO-SEND) */
+ osmo_timer_schedule(&dl->t200, dl->t200_sec, dl->t200_usec);
+ break;
+ case LAPD_STATE_MF_EST:
+ /* 5.5.7 */
+ dl->retrans_ctr = 0;
+ lapd_dl_newstate(dl, LAPD_STATE_TIMER_RECOV);
+ /* fall through */
+ case LAPD_STATE_TIMER_RECOV:
+ dl->retrans_ctr++;
+ if (dl->retrans_ctr < dl->n200) {
+ uint8_t vs = sub_mod(dl->v_send, 1, dl->v_range);
+ uint8_t h = do_mod(vs, dl->range_hist);
+ /* retransmit I frame (V_s-1) with P=1, if any */
+ if (dl->tx_hist[h].msg) {
+ struct msgb *msg;
+ int length = dl->tx_hist[h].msg->len;
+ struct lapd_msg_ctx nctx;
+
+ LOGP(DLLAPD, LOGL_INFO, "retransmit last frame"
+ " V(S)=%d\n", vs);
+ /* Create I frame (segment) from tx_hist */
+ memcpy(&nctx, &dl->lctx, sizeof(nctx));
+ /* keep nctx.ldp */
+ /* keep nctx.sapi */
+ /* keep nctx.tei */
+ nctx.cr = dl->cr.loc2rem.cmd;
+ nctx.format = LAPD_FORM_I;
+ nctx.p_f = 1;
+ nctx.n_send = vs;
+ nctx.n_recv = dl->v_recv;
+ nctx.length = length;
+ nctx.more = dl->tx_hist[h].more;
+ msg = lapd_msgb_alloc(length, "LAPD I resend");
+ msg->l3h = msgb_put(msg, length);
+ memcpy(msg->l3h, dl->tx_hist[h].msg->data,
+ length);
+ dl->send_ph_data_req(&nctx, msg);
+ } else {
+ /* OR send appropriate supervision frame with P=1 */
+ if (!dl->own_busy && !dl->seq_err_cond) {
+ lapd_send_rr(&dl->lctx, 1, 1);
+ /* NOTE: In case of sequence error
+ * condition, the REJ frame has been
+ * transmitted when entering the
+ * condition, so it has not be done
+ * here
+ */
+ } else if (dl->own_busy) {
+ lapd_send_rnr(&dl->lctx, 1, 1);
+ } else {
+ LOGP(DLLAPD, LOGL_INFO, "unhandled, "
+ "pls. fix\n");
+ }
+ }
+ /* restart T200 (PH-READY-TO-SEND) */
+ osmo_timer_schedule(&dl->t200, dl->t200_sec,
+ dl->t200_usec);
+ } else {
+ /* send MDL ERROR INIDCATION to L3 */
+ mdl_error(MDL_CAUSE_T200_EXPIRED, &dl->lctx);
+ /* reestablish */
+ if (!dl->reestablish)
+ break;
+ LOGP(DLLAPD, LOGL_NOTICE, "N200 reached, performing "
+ "reestablishment.\n");
+ lapd_reestablish(dl);
+ }
+ break;
+ default:
+ LOGP(DLLAPD, LOGL_INFO, "T200 expired in unexpected "
+ "dl->state %d\n", (int) dl->state);
+ }
+}
+
+/* Timer callback on T203 expiry */
+static void lapd_t203_cb(void *data)
+{
+ struct lapd_datalink *dl = data;
+
+ LOGP(DLLAPD, LOGL_INFO, "lapd_t203_cb(%p) state=%d\n", dl,
+ (int) dl->state);
+
+ if (dl->state != LAPD_STATE_MF_EST) {
+ LOGP(DLLAPD, LOGL_ERROR, "T203 fired outside MF EST state, "
+ "please fix!\n");
+ return;
+ }
+
+ /* set retransmission counter to 0 */
+ dl->retrans_ctr = 0;
+ /* enter timer recovery state */
+ lapd_dl_newstate(dl, LAPD_STATE_TIMER_RECOV);
+ /* transmit a supervisory command with P bit set to 1 as follows: */
+ if (!dl->own_busy) {
+ LOGP(DLLAPD, LOGL_INFO, "transmit an RR poll command\n");
+ /* Send RR with P=1 */
+ lapd_send_rr(&dl->lctx, 1, 1);
+ } else {
+ LOGP(DLLAPD, LOGL_INFO, "transmit an RNR poll command\n");
+ /* Send RNR with P=1 */
+ lapd_send_rnr(&dl->lctx, 1, 1);
+ }
+ /* start T200 */
+ osmo_timer_schedule(&dl->t200, dl->t200_sec, dl->t200_usec);
+}
+
+/* 5.5.3.1: Common function to acknowlege frames up to the given N(R) value */
+static void lapd_acknowledge(struct lapd_msg_ctx *lctx)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ uint8_t nr = lctx->n_recv;
+ int s = 0, rej = 0, t200_reset = 0, t200_start = 0;
+ int i, h;
+
+ /* supervisory frame ? */
+ if (lctx->format == LAPD_FORM_S)
+ s = 1;
+ /* REJ frame ? */
+ if (s && lctx->s_u == LAPD_S_REJ)
+ rej = 1;
+
+ /* Flush all transmit buffers of acknowledged frames */
+ for (i = dl->v_ack; i != nr; i = inc_mod(i, dl->v_range)) {
+ h = do_mod(i, dl->range_hist);
+ if (dl->tx_hist[h].msg) {
+ msgb_free(dl->tx_hist[h].msg);
+ dl->tx_hist[h].msg = NULL;
+ LOGP(DLLAPD, LOGL_INFO, "ack frame %d\n", i);
+ }
+ }
+
+ if (dl->state != LAPD_STATE_TIMER_RECOV) {
+ /* When not in the timer recovery condition, the data
+ * link layer entity shall reset the timer T200 on
+ * receipt of a valid I frame with N(R) higher than V(A),
+ * or an REJ with an N(R) equal to V(A). */
+ if ((!rej && nr != dl->v_ack)
+ || (rej && nr == dl->v_ack)) {
+ LOGP(DLLAPD, LOGL_INFO, "reset t200\n");
+ t200_reset = 1;
+ osmo_timer_del(&dl->t200);
+ /* 5.5.3.1 Note 1 + 2 imply timer recovery cond. */
+ }
+ /* 5.7.4: N(R) sequence error
+ * N(R) is called valid, if and only if
+ * (N(R)-V(A)) mod 8 <= (V(S)-V(A)) mod 8.
+ */
+ if (sub_mod(nr, dl->v_ack, dl->v_range)
+ > sub_mod(dl->v_send, dl->v_ack, dl->v_range)) {
+ LOGP(DLLAPD, LOGL_NOTICE, "N(R) sequence error\n");
+ mdl_error(MDL_CAUSE_SEQ_ERR, lctx);
+ }
+ }
+
+ /* V(A) shall be set to the value of N(R) */
+ dl->v_ack = nr;
+
+ /* If T200 has been reset by the receipt of an I, RR or RNR frame,
+ * and if there are outstanding I frames, restart T200 */
+ if (t200_reset && !rej) {
+ if (dl->tx_hist[sub_mod(dl->v_send, 1, dl->range_hist)].msg) {
+ LOGP(DLLAPD, LOGL_INFO, "start T200, due to unacked I "
+ "frame(s)\n");
+ t200_start = 1;
+ osmo_timer_schedule(&dl->t200, dl->t200_sec,
+ dl->t200_usec);
+ }
+ }
+
+ /* This also does a restart, when I or S frame is received */
+
+ /* Stop T203, if running */
+ if (osmo_timer_pending(&dl->t203)) {
+ osmo_timer_del(&dl->t203);
+ LOGP(DLLAPD, LOGL_INFO, "stop T203\n");
+ }
+ /* Start T203, if T200 is not running in MF EST state, if enabled */
+ if (!osmo_timer_pending(&dl->t200)
+ && (dl->t203_sec || dl->t203_usec)
+ && (dl->state == LAPD_STATE_MF_EST)) {
+ LOGP(DLLAPD, LOGL_INFO, "start T203\n");
+ osmo_timer_schedule(&dl->t203, dl->t203_sec, dl->t203_usec);
+ }
+}
+
+/* L1 -> L2 */
+
+/* Receive a LAPD U (Unnumbered) message from L1 */
+static int lapd_rx_u(struct msgb *msg, struct lapd_msg_ctx *lctx)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ int length = lctx->length;
+ int rc;
+ uint8_t prim, op;
+
+ switch (lctx->s_u) {
+ case LAPD_U_SABM:
+ case LAPD_U_SABME:
+ prim = PRIM_DL_EST;
+ op = PRIM_OP_INDICATION;
+
+ LOGP(DLLAPD, LOGL_INFO, "SABM(E) received in state %s\n",
+ lapd_state_names[dl->state]);
+ /* 5.7.1 */
+ dl->seq_err_cond = 0;
+ /* G.2.2 Wrong value of the C/R bit */
+ if (lctx->cr == dl->cr.rem2loc.resp) {
+ LOGP(DLLAPD, LOGL_NOTICE, "SABM response error\n");
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_FRM_UNIMPL, lctx);
+ return -EINVAL;
+ }
+
+ /* G.4.5 If SABM is received with L>N201 or with M bit
+ * set, AN MDL-ERROR-INDICATION is sent to MM.
+ */
+ if (lctx->more || length > lctx->n201) {
+ LOGP(DLLAPD, LOGL_NOTICE, "SABM too large error\n");
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_UFRM_INC_PARAM, lctx);
+ return -EIO;
+ }
+
+ switch (dl->state) {
+ case LAPD_STATE_IDLE:
+ break;
+ case LAPD_STATE_MF_EST:
+ LOGP(DLLAPD, LOGL_INFO, "SABM command, multiple "
+ "frame established state\n");
+ /* If link is lost on the remote side, we start over
+ * and send DL-ESTABLISH indication again. */
+ if (dl->v_send != dl->v_recv) {
+ LOGP(DLLAPD, LOGL_INFO, "Remote reestablish\n");
+ mdl_error(MDL_CAUSE_SABM_MF, lctx);
+ break;
+ }
+ /* Ignore SABM if content differs from first SABM. */
+ if (dl->mode == LAPD_MODE_NETWORK && length
+ && dl->cont_res) {
+#ifdef TEST_CONTENT_RESOLUTION_NETWORK
+ dl->cont_res->data[0] ^= 0x01;
+#endif
+ if (memcmp(dl->cont_res, msg->data, length)) {
+ LOGP(DLLAPD, LOGL_INFO, "Another SABM "
+ "with diffrent content - "
+ "ignoring!\n");
+ msgb_free(msg);
+ return 0;
+ }
+ }
+ /* send UA again */
+ lapd_send_ua(lctx, length, msg->l3h);
+ msgb_free(msg);
+ return 0;
+ case LAPD_STATE_DISC_SENT:
+ /* 5.4.6.2 send DM with F=P */
+ lapd_send_dm(lctx);
+ /* reset Timer T200 */
+ osmo_timer_del(&dl->t200);
+ msgb_free(msg);
+ return send_dl_simple(prim, op, lctx);
+ default:
+ /* collision: Send UA, but still wait for rx UA, then
+ * change to MF_EST state.
+ */
+ /* check for contention resoultion */
+ if (dl->tx_hist[0].msg && dl->tx_hist[0].msg->len) {
+ LOGP(DLLAPD, LOGL_NOTICE, "SABM not allowed "
+ "during contention resolution\n");
+ mdl_error(MDL_CAUSE_SABM_INFO_NOTALL, lctx);
+ }
+ lapd_send_ua(lctx, length, msg->l3h);
+ msgb_free(msg);
+ return 0;
+ }
+ /* save message context for further use */
+ memcpy(&dl->lctx, lctx, sizeof(dl->lctx));
+#ifndef TEST_CONTENT_RESOLUTION_NETWORK
+ /* send UA response */
+ lapd_send_ua(lctx, length, msg->l3h);
+#endif
+ /* set Vs, Vr and Va to 0 */
+ dl->v_send = dl->v_recv = dl->v_ack = 0;
+ /* clear tx_hist */
+ lapd_dl_flush_hist(dl);
+ /* enter multiple-frame-established state */
+ lapd_dl_newstate(dl, LAPD_STATE_MF_EST);
+ /* store content resolution data on network side
+ * Note: cont_res will be removed when changing state again,
+ * so it must be allocated AFTER lapd_dl_newstate(). */
+ if (dl->mode == LAPD_MODE_NETWORK && length) {
+ dl->cont_res = lapd_msgb_alloc(length, "CONT RES");
+ memcpy(msgb_put(dl->cont_res, length), msg->l3h,
+ length);
+ LOGP(DLLAPD, LOGL_NOTICE, "Store content res.\n");
+ }
+ /* send notification to L3 */
+ if (length == 0) {
+ /* 5.4.1.2 Normal establishment procedures */
+ rc = send_dl_simple(prim, op, lctx);
+ msgb_free(msg);
+ } else {
+ /* 5.4.1.4 Contention resolution establishment */
+ rc = send_dl_l3(prim, op, lctx, msg);
+ }
+ break;
+ case LAPD_U_DM:
+ LOGP(DLLAPD, LOGL_INFO, "DM received in state %s\n",
+ lapd_state_names[dl->state]);
+ /* G.2.2 Wrong value of the C/R bit */
+ if (lctx->cr == dl->cr.rem2loc.cmd) {
+ LOGP(DLLAPD, LOGL_NOTICE, "DM command error\n");
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_FRM_UNIMPL, lctx);
+ return -EINVAL;
+ }
+ if (!lctx->p_f) {
+ /* 5.4.1.2 DM responses with the F bit set to "0"
+ * shall be ignored.
+ */
+ msgb_free(msg);
+ return 0;
+ }
+ switch (dl->state) {
+ case LAPD_STATE_SABM_SENT:
+ break;
+ case LAPD_STATE_MF_EST:
+ if (lctx->p_f) {
+ LOGP(DLLAPD, LOGL_INFO, "unsolicited DM "
+ "response\n");
+ mdl_error(MDL_CAUSE_UNSOL_DM_RESP, lctx);
+ } else {
+ LOGP(DLLAPD, LOGL_INFO, "unsolicited DM "
+ "response, multiple frame established "
+ "state\n");
+ mdl_error(MDL_CAUSE_UNSOL_DM_RESP_MF, lctx);
+ /* reestablish */
+ if (!dl->reestablish) {
+ msgb_free(msg);
+ return 0;
+ }
+ LOGP(DLLAPD, LOGL_NOTICE, "Performing "
+ "reestablishment.\n");
+ lapd_reestablish(dl);
+ }
+ msgb_free(msg);
+ return 0;
+ case LAPD_STATE_TIMER_RECOV:
+ /* FP = 0 (DM is normal in case PF = 1) */
+ if (!lctx->p_f) {
+ LOGP(DLLAPD, LOGL_INFO, "unsolicited DM "
+ "response, multiple frame established "
+ "state\n");
+ mdl_error(MDL_CAUSE_UNSOL_DM_RESP_MF, lctx);
+ msgb_free(msg);
+ /* reestablish */
+ if (!dl->reestablish)
+ return 0;
+ LOGP(DLLAPD, LOGL_NOTICE, "Performing "
+ "reestablishment.\n");
+ return lapd_reestablish(dl);
+ }
+ break;
+ case LAPD_STATE_DISC_SENT:
+ /* reset Timer T200 */
+ osmo_timer_del(&dl->t200);
+ /* go to idle state */
+ lapd_dl_flush_tx(dl);
+ lapd_dl_flush_send(dl);
+ lapd_dl_newstate(dl, LAPD_STATE_IDLE);
+ rc = send_dl_simple(PRIM_DL_REL, PRIM_OP_CONFIRM, lctx);
+ msgb_free(msg);
+ return 0;
+ case LAPD_STATE_IDLE:
+ /* 5.4.5 all other frame types shall be discarded */
+ default:
+ LOGP(DLLAPD, LOGL_INFO, "unsolicited DM response! "
+ "(discarding)\n");
+ msgb_free(msg);
+ return 0;
+ }
+ /* reset T200 */
+ osmo_timer_del(&dl->t200);
+ /* go to idle state */
+ lapd_dl_newstate(dl, LAPD_STATE_IDLE);
+ rc = send_dl_simple(PRIM_DL_REL, PRIM_OP_INDICATION, lctx);
+ msgb_free(msg);
+ break;
+ case LAPD_U_UI:
+ LOGP(DLLAPD, LOGL_INFO, "UI received\n");
+ /* G.2.2 Wrong value of the C/R bit */
+ if (lctx->cr == dl->cr.rem2loc.resp) {
+ LOGP(DLLAPD, LOGL_NOTICE, "UI indicates response "
+ "error\n");
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_FRM_UNIMPL, lctx);
+ return -EINVAL;
+ }
+
+ /* G.4.5 If UI is received with L>N201 or with M bit
+ * set, AN MDL-ERROR-INDICATION is sent to MM.
+ */
+ if (length > lctx->n201 || lctx->more) {
+ LOGP(DLLAPD, LOGL_NOTICE, "UI too large error "
+ "(%d > N201(%d) or M=%d)\n", length,
+ lctx->n201, lctx->more);
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_UFRM_INC_PARAM, lctx);
+ return -EIO;
+ }
+
+ /* do some length checks */
+ if (length == 0) {
+ /* 5.3.3 UI frames received with the length indicator
+ * set to "0" shall be ignored
+ */
+ LOGP(DLLAPD, LOGL_INFO, "length=0 (discarding)\n");
+ msgb_free(msg);
+ return 0;
+ }
+ rc = send_dl_l3(PRIM_DL_UNIT_DATA, PRIM_OP_INDICATION, lctx,
+ msg);
+ break;
+ case LAPD_U_DISC:
+ prim = PRIM_DL_REL;
+ op = PRIM_OP_INDICATION;
+
+ LOGP(DLLAPD, LOGL_INFO, "DISC received in state %s\n",
+ lapd_state_names[dl->state]);
+ /* flush tx and send buffers */
+ lapd_dl_flush_tx(dl);
+ lapd_dl_flush_send(dl);
+ /* 5.7.1 */
+ dl->seq_err_cond = 0;
+ /* G.2.2 Wrong value of the C/R bit */
+ if (lctx->cr == dl->cr.rem2loc.resp) {
+ LOGP(DLLAPD, LOGL_NOTICE, "DISC response error\n");
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_FRM_UNIMPL, lctx);
+ return -EINVAL;
+ }
+ if (length > 0 || lctx->more) {
+ /* G.4.4 If a DISC or DM frame is received with L>0 or
+ * with the M bit set to "1", an MDL-ERROR-INDICATION
+ * primitive with cause "U frame with incorrect
+ * parameters" is sent to the mobile management entity.
+ */
+ LOGP(DLLAPD, LOGL_NOTICE,
+ "U frame iwth incorrect parameters ");
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_UFRM_INC_PARAM, lctx);
+ return -EIO;
+ }
+ switch (dl->state) {
+ case LAPD_STATE_IDLE:
+ LOGP(DLLAPD, LOGL_INFO, "DISC in idle state\n");
+ /* send DM with F=P */
+ msgb_free(msg);
+ return lapd_send_dm(lctx);
+ case LAPD_STATE_SABM_SENT:
+ LOGP(DLLAPD, LOGL_INFO, "DISC in SABM state\n");
+ /* 5.4.6.2 send DM with F=P */
+ lapd_send_dm(lctx);
+ /* reset Timer T200 */
+ osmo_timer_del(&dl->t200);
+ /* go to idle state */
+ lapd_dl_newstate(dl, LAPD_STATE_IDLE);
+ msgb_free(msg);
+ return send_dl_simple(PRIM_DL_REL, PRIM_OP_INDICATION,
+ lctx);
+ case LAPD_STATE_MF_EST:
+ case LAPD_STATE_TIMER_RECOV:
+ LOGP(DLLAPD, LOGL_INFO, "DISC in est state\n");
+ break;
+ case LAPD_STATE_DISC_SENT:
+ LOGP(DLLAPD, LOGL_INFO, "DISC in disc state\n");
+ prim = PRIM_DL_REL;
+ op = PRIM_OP_CONFIRM;
+ break;
+ default:
+ lapd_send_ua(lctx, length, msg->l3h);
+ msgb_free(msg);
+ return 0;
+ }
+ /* send UA response */
+ lapd_send_ua(lctx, length, msg->l3h);
+ /* reset Timer T200 */
+ osmo_timer_del(&dl->t200);
+ /* enter idle state, keep tx-buffer with UA response */
+ lapd_dl_newstate(dl, LAPD_STATE_IDLE);
+ /* send notification to L3 */
+ rc = send_dl_simple(prim, op, lctx);
+ msgb_free(msg);
+ break;
+ case LAPD_U_UA:
+ LOGP(DLLAPD, LOGL_INFO, "UA received in state %s\n",
+ lapd_state_names[dl->state]);
+ /* G.2.2 Wrong value of the C/R bit */
+ if (lctx->cr == dl->cr.rem2loc.cmd) {
+ LOGP(DLLAPD, LOGL_NOTICE, "UA indicates command "
+ "error\n");
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_FRM_UNIMPL, lctx);
+ return -EINVAL;
+ }
+
+ /* G.4.5 If UA is received with L>N201 or with M bit
+ * set, AN MDL-ERROR-INDICATION is sent to MM.
+ */
+ if (lctx->more || length > lctx->n201) {
+ LOGP(DLLAPD, LOGL_NOTICE, "UA too large error\n");
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_UFRM_INC_PARAM, lctx);
+ return -EIO;
+ }
+
+ if (!lctx->p_f) {
+ /* 5.4.1.2 A UA response with the F bit set to "0"
+ * shall be ignored.
+ */
+ LOGP(DLLAPD, LOGL_INFO, "F=0 (discarding)\n");
+ msgb_free(msg);
+ return 0;
+ }
+ switch (dl->state) {
+ case LAPD_STATE_SABM_SENT:
+ break;
+ case LAPD_STATE_MF_EST:
+ case LAPD_STATE_TIMER_RECOV:
+ LOGP(DLLAPD, LOGL_INFO, "unsolicited UA response! "
+ "(discarding)\n");
+ mdl_error(MDL_CAUSE_UNSOL_UA_RESP, lctx);
+ msgb_free(msg);
+ return 0;
+ case LAPD_STATE_DISC_SENT:
+ LOGP(DLLAPD, LOGL_INFO, "UA in disconnect state\n");
+ /* reset Timer T200 */
+ osmo_timer_del(&dl->t200);
+ /* go to idle state */
+ lapd_dl_flush_tx(dl);
+ lapd_dl_flush_send(dl);
+ lapd_dl_newstate(dl, LAPD_STATE_IDLE);
+ rc = send_dl_simple(PRIM_DL_REL, PRIM_OP_CONFIRM, lctx);
+ msgb_free(msg);
+ return 0;
+ case LAPD_STATE_IDLE:
+ /* 5.4.5 all other frame types shall be discarded */
+ default:
+ LOGP(DLLAPD, LOGL_INFO, "unsolicited UA response! "
+ "(discarding)\n");
+ msgb_free(msg);
+ return 0;
+ }
+ LOGP(DLLAPD, LOGL_INFO, "UA in SABM state\n");
+ /* reset Timer T200 */
+ osmo_timer_del(&dl->t200);
+ /* compare UA with SABME if contention resolution is applied */
+ if (dl->tx_hist[0].msg->len) {
+ if (length != (dl->tx_hist[0].msg->len)
+ || !!memcmp(dl->tx_hist[0].msg->data, msg->l3h,
+ length)) {
+ LOGP(DLLAPD, LOGL_INFO, "**** UA response "
+ "mismatches ****\n");
+ rc = send_dl_simple(PRIM_DL_REL,
+ PRIM_OP_INDICATION, lctx);
+ msgb_free(msg);
+ /* go to idle state */
+ lapd_dl_flush_tx(dl);
+ lapd_dl_flush_send(dl);
+ lapd_dl_newstate(dl, LAPD_STATE_IDLE);
+ return 0;
+ }
+ }
+ /* set Vs, Vr and Va to 0 */
+ dl->v_send = dl->v_recv = dl->v_ack = 0;
+ /* clear tx_hist */
+ lapd_dl_flush_hist(dl);
+ /* enter multiple-frame-established state */
+ lapd_dl_newstate(dl, LAPD_STATE_MF_EST);
+ /* send outstanding frames, if any (resume / reconnect) */
+ lapd_send_i(lctx, __LINE__);
+ /* send notification to L3 */
+ rc = send_dl_simple(PRIM_DL_EST, PRIM_OP_CONFIRM, lctx);
+ msgb_free(msg);
+ break;
+ case LAPD_U_FRMR:
+ LOGP(DLLAPD, LOGL_NOTICE, "Frame reject received\n");
+ /* send MDL ERROR INIDCATION to L3 */
+ mdl_error(MDL_CAUSE_FRMR, lctx);
+ msgb_free(msg);
+ /* reestablish */
+ if (!dl->reestablish)
+ break;
+ LOGP(DLLAPD, LOGL_NOTICE, "Performing reestablishment.\n");
+ rc = lapd_reestablish(dl);
+ break;
+ default:
+ /* G.3.1 */
+ LOGP(DLLAPD, LOGL_NOTICE, "Unnumbered frame not allowed.\n");
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_FRM_UNIMPL, lctx);
+ return -EINVAL;
+ }
+ return rc;
+}
+
+/* Receive a LAPD S (Supervisory) message from L1 */
+static int lapd_rx_s(struct msgb *msg, struct lapd_msg_ctx *lctx)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ int length = lctx->length;
+
+ if (length > 0 || lctx->more) {
+ /* G.4.3 If a supervisory frame is received with L>0 or
+ * with the M bit set to "1", an MDL-ERROR-INDICATION
+ * primitive with cause "S frame with incorrect
+ * parameters" is sent to the mobile management entity. */
+ LOGP(DLLAPD, LOGL_NOTICE,
+ "S frame with incorrect parameters\n");
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_SFRM_INC_PARAM, lctx);
+ return -EIO;
+ }
+
+ if (lctx->cr == dl->cr.rem2loc.resp
+ && lctx->p_f
+ && dl->state != LAPD_STATE_TIMER_RECOV) {
+ /* 5.4.2.2: Inidcate error on supervisory reponse F=1 */
+ LOGP(DLLAPD, LOGL_NOTICE, "S frame response with F=1 error\n");
+ mdl_error(MDL_CAUSE_UNSOL_SPRV_RESP, lctx);
+ }
+
+ switch (dl->state) {
+ case LAPD_STATE_IDLE:
+ /* if P=1, respond DM with F=1 (5.2.2) */
+ /* 5.4.5 all other frame types shall be discarded */
+ if (lctx->p_f)
+ lapd_send_dm(lctx); /* F=P */
+ /* fall though */
+ case LAPD_STATE_SABM_SENT:
+ case LAPD_STATE_DISC_SENT:
+ LOGP(DLLAPD, LOGL_NOTICE, "S frame ignored in this state\n");
+ msgb_free(msg);
+ return 0;
+ }
+ switch (lctx->s_u) {
+ case LAPD_S_RR:
+ LOGP(DLLAPD, LOGL_INFO, "RR received in state %s\n",
+ lapd_state_names[dl->state]);
+ /* 5.5.3.1: Acknowlege all tx frames up the the N(R)-1 */
+ lapd_acknowledge(lctx);
+
+ /* 5.5.3.2 */
+ if (lctx->cr == dl->cr.rem2loc.cmd
+ && lctx->p_f) {
+ if (!dl->own_busy && !dl->seq_err_cond) {
+ LOGP(DLLAPD, LOGL_INFO, "RR frame command "
+ "with polling bit set and we are not "
+ "busy, so we reply with RR frame "
+ "response\n");
+ lapd_send_rr(lctx, 1, 0);
+ /* NOTE: In case of sequence error condition,
+ * the REJ frame has been transmitted when
+ * entering the condition, so it has not be
+ * done here
+ */
+ } else if (dl->own_busy) {
+ LOGP(DLLAPD, LOGL_INFO, "RR frame command "
+ "with polling bit set and we are busy, "
+ "so we reply with RR frame response\n");
+ lapd_send_rnr(lctx, 1, 0);
+ }
+ } else if (lctx->cr == dl->cr.rem2loc.resp
+ && lctx->p_f
+ && dl->state == LAPD_STATE_TIMER_RECOV) {
+ LOGP(DLLAPD, LOGL_INFO, "RR response with F==1, "
+ "and we are in timer recovery state, so "
+ "we leave that state\n");
+ /* V(S) to the N(R) in the RR frame */
+ dl->v_send = lctx->n_recv;
+ /* reset Timer T200 */
+ osmo_timer_del(&dl->t200);
+ /* 5.5.7 Clear timer recovery condition */
+ lapd_dl_newstate(dl, LAPD_STATE_MF_EST);
+ }
+ /* Send message, if possible due to acknowledged data */
+ lapd_send_i(lctx, __LINE__);
+
+ break;
+ case LAPD_S_RNR:
+ LOGP(DLLAPD, LOGL_INFO, "RNR received in state %s\n",
+ lapd_state_names[dl->state]);
+ /* 5.5.3.1: Acknowlege all tx frames up the the N(R)-1 */
+ lapd_acknowledge(lctx);
+
+ /* 5.5.5 */
+ /* Set peer receiver busy condition */
+ dl->peer_busy = 1;
+
+ if (lctx->p_f) {
+ if (lctx->cr == dl->cr.rem2loc.cmd) {
+ if (!dl->own_busy) {
+ LOGP(DLLAPD, LOGL_INFO, "RNR poll "
+ "command and we are not busy, "
+ "so we reply with RR final "
+ "response\n");
+ /* Send RR with F=1 */
+ lapd_send_rr(lctx, 1, 0);
+ } else {
+ LOGP(DLLAPD, LOGL_INFO, "RNR poll "
+ "command and we are busy, so "
+ "we reply with RNR final "
+ "response\n");
+ /* Send RNR with F=1 */
+ lapd_send_rnr(lctx, 1, 0);
+ }
+ } else if (dl->state == LAPD_STATE_TIMER_RECOV) {
+ LOGP(DLLAPD, LOGL_INFO, "RNR poll response "
+ "and we in timer recovery state, so "
+ "we leave that state\n");
+ /* 5.5.7 Clear timer recovery condition */
+ lapd_dl_newstate(dl, LAPD_STATE_MF_EST);
+ /* V(S) to the N(R) in the RNR frame */
+ dl->v_send = lctx->n_recv;
+ }
+ } else
+ LOGP(DLLAPD, LOGL_INFO, "RNR not polling/final state "
+ "received\n");
+
+ /* Send message, if possible due to acknowledged data */
+ lapd_send_i(lctx, __LINE__);
+
+ break;
+ case LAPD_S_REJ:
+ LOGP(DLLAPD, LOGL_INFO, "REJ received in state %s\n",
+ lapd_state_names[dl->state]);
+ /* 5.5.3.1: Acknowlege all tx frames up the the N(R)-1 */
+ lapd_acknowledge(lctx);
+
+ /* 5.5.4.1 */
+ if (dl->state != LAPD_STATE_TIMER_RECOV) {
+ /* Clear an existing peer receiver busy condition */
+ dl->peer_busy = 0;
+ /* V(S) and V(A) to the N(R) in the REJ frame */
+ dl->v_send = dl->v_ack = lctx->n_recv;
+ /* reset Timer T200 */
+ osmo_timer_del(&dl->t200);
+ /* 5.5.3.2 */
+ if (lctx->cr == dl->cr.rem2loc.cmd && lctx->p_f) {
+ if (!dl->own_busy && !dl->seq_err_cond) {
+ LOGP(DLLAPD, LOGL_INFO, "REJ poll "
+ "command not in timer recovery "
+ "state and not in own busy "
+ "condition received, so we "
+ "respond with RR final "
+ "response\n");
+ lapd_send_rr(lctx, 1, 0);
+ /* NOTE: In case of sequence error
+ * condition, the REJ frame has been
+ * transmitted when entering the
+ * condition, so it has not be done
+ * here
+ */
+ } else if (dl->own_busy) {
+ LOGP(DLLAPD, LOGL_INFO, "REJ poll "
+ "command not in timer recovery "
+ "state and in own busy "
+ "condition received, so we "
+ "respond with RNR final "
+ "response\n");
+ lapd_send_rnr(lctx, 1, 0);
+ }
+ } else
+ LOGP(DLLAPD, LOGL_INFO, "REJ response or not "
+ "polling command not in timer recovery "
+ "state received\n");
+ /* send MDL ERROR INIDCATION to L3 */
+ if (lctx->cr == dl->cr.rem2loc.resp && lctx->p_f) {
+ mdl_error(MDL_CAUSE_UNSOL_SPRV_RESP, lctx);
+ }
+
+ } else if (lctx->cr == dl->cr.rem2loc.resp && lctx->p_f) {
+ LOGP(DLLAPD, LOGL_INFO, "REJ poll response in timer "
+ "recovery state received\n");
+ /* Clear an existing peer receiver busy condition */
+ dl->peer_busy = 0;
+ /* V(S) and V(A) to the N(R) in the REJ frame */
+ dl->v_send = dl->v_ack = lctx->n_recv;
+ /* reset Timer T200 */
+ osmo_timer_del(&dl->t200);
+ /* 5.5.7 Clear timer recovery condition */
+ lapd_dl_newstate(dl, LAPD_STATE_MF_EST);
+ } else {
+ /* Clear an existing peer receiver busy condition */
+ dl->peer_busy = 0;
+ /* V(S) and V(A) to the N(R) in the REJ frame */
+ dl->v_send = dl->v_ack = lctx->n_recv;
+ /* 5.5.3.2 */
+ if (lctx->cr == dl->cr.rem2loc.cmd && lctx->p_f) {
+ if (!dl->own_busy && !dl->seq_err_cond) {
+ LOGP(DLLAPD, LOGL_INFO, "REJ poll "
+ "command in timer recovery "
+ "state and not in own busy "
+ "condition received, so we "
+ "respond with RR final "
+ "response\n");
+ lapd_send_rr(lctx, 1, 0);
+ /* NOTE: In case of sequence error
+ * condition, the REJ frame has been
+ * transmitted when entering the
+ * condition, so it has not be done
+ * here
+ */
+ } else if (dl->own_busy) {
+ LOGP(DLLAPD, LOGL_INFO, "REJ poll "
+ "command in timer recovery "
+ "state and in own busy "
+ "condition received, so we "
+ "respond with RNR final "
+ "response\n");
+ lapd_send_rnr(lctx, 1, 0);
+ }
+ } else
+ LOGP(DLLAPD, LOGL_INFO, "REJ response or not "
+ "polling command in timer recovery "
+ "state received\n");
+ }
+
+ /* FIXME: 5.5.4.2 2) */
+
+ /* Send message, if possible due to acknowledged data */
+ lapd_send_i(lctx, __LINE__);
+
+ break;
+ default:
+ /* G.3.1 */
+ LOGP(DLLAPD, LOGL_NOTICE, "Supervisory frame not allowed.\n");
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_FRM_UNIMPL, lctx);
+ return -EINVAL;
+ }
+ msgb_free(msg);
+ return 0;
+}
+
+/* Receive a LAPD I (Information) message from L1 */
+static int lapd_rx_i(struct msgb *msg, struct lapd_msg_ctx *lctx)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ //uint8_t nr = lctx->n_recv;
+ uint8_t ns = lctx->n_send;
+ int length = lctx->length;
+ int rc;
+
+ LOGP(DLLAPD, LOGL_INFO, "I received in state %s\n",
+ lapd_state_names[dl->state]);
+
+ /* G.2.2 Wrong value of the C/R bit */
+ if (lctx->cr == dl->cr.rem2loc.resp) {
+ LOGP(DLLAPD, LOGL_NOTICE, "I frame response not allowed\n");
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_FRM_UNIMPL, lctx);
+ return -EINVAL;
+ }
+
+ if (length == 0 || length > lctx->n201) {
+ /* G.4.2 If the length indicator of an I frame is set
+ * to a numerical value L>N201 or L=0, an MDL-ERROR-INDICATION
+ * primitive with cause "I frame with incorrect length"
+ * is sent to the mobile management entity. */
+ LOGP(DLLAPD, LOGL_NOTICE, "I frame length not allowed\n");
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_IFRM_INC_LEN, lctx);
+ return -EIO;
+ }
+
+ /* G.4.2 If the numerical value of L is L<N201 and the M
+ * bit is set to "1", then an MDL-ERROR-INDICATION primitive with
+ * cause "I frame with incorrect use of M bit" is sent to the
+ * mobile management entity. */
+ if (lctx->more && length < lctx->n201) {
+ LOGP(DLLAPD, LOGL_NOTICE, "I frame with M bit too short\n");
+ msgb_free(msg);
+ mdl_error(MDL_CAUSE_IFRM_INC_MBITS, lctx);
+ return -EIO;
+ }
+
+ switch (dl->state) {
+ case LAPD_STATE_IDLE:
+ /* if P=1, respond DM with F=1 (5.2.2) */
+ /* 5.4.5 all other frame types shall be discarded */
+ if (lctx->p_f)
+ lapd_send_dm(lctx); /* F=P */
+ /* fall though */
+ case LAPD_STATE_SABM_SENT:
+ case LAPD_STATE_DISC_SENT:
+ LOGP(DLLAPD, LOGL_NOTICE, "I frame ignored in this state\n");
+ msgb_free(msg);
+ return 0;
+ }
+
+ /* 5.7.1: N(s) sequence error */
+ if (ns != dl->v_recv) {
+ LOGP(DLLAPD, LOGL_NOTICE, "N(S) sequence error: N(S)=%u, "
+ "V(R)=%u\n", ns, dl->v_recv);
+ /* discard data */
+ msgb_free(msg);
+ if (!dl->seq_err_cond) {
+ /* FIXME: help me understand what exactly todo here
+ dl->seq_err_cond = 1;
+ */
+ lapd_send_rej(lctx, lctx->p_f);
+ } else {
+ }
+ return -EIO;
+ }
+ dl->seq_err_cond = 0;
+
+ /* Increment receiver state */
+ dl->v_recv = inc_mod(dl->v_recv, dl->v_range);
+ LOGP(DLLAPD, LOGL_INFO, "incrementing V(R) to %u\n", dl->v_recv);
+
+ /* 5.5.3.1: Acknowlege all transmitted frames up the the N(R)-1 */
+ lapd_acknowledge(lctx); /* V(A) is also set here */
+
+ /* Only if we are not in own receiver busy condition */
+ if (!dl->own_busy) {
+ /* if the frame carries a complete segment */
+ if (!lctx->more && !dl->rcv_buffer) {
+ LOGP(DLLAPD, LOGL_INFO, "message in single I frame\n");
+ /* send a DATA INDICATION to L3 */
+ msg->len = length;
+ msg->tail = msg->data + length;
+ rc = send_dl_l3(PRIM_DL_DATA, PRIM_OP_INDICATION, lctx,
+ msg);
+ } else {
+ /* create rcv_buffer */
+ if (!dl->rcv_buffer) {
+ LOGP(DLLAPD, LOGL_INFO, "message in multiple "
+ "I frames (first message)\n");
+ dl->rcv_buffer = lapd_msgb_alloc(dl->maxf,
+ "LAPD RX");
+ dl->rcv_buffer->l3h = dl->rcv_buffer->data;
+ }
+ /* concat. rcv_buffer */
+ if (msgb_l3len(dl->rcv_buffer) + length > dl->maxf) {
+ LOGP(DLLAPD, LOGL_NOTICE, "Received frame "
+ "overflow!\n");
+ } else {
+ memcpy(msgb_put(dl->rcv_buffer, length),
+ msg->l3h, length);
+ }
+ /* if the last segment was received */
+ if (!lctx->more) {
+ LOGP(DLLAPD, LOGL_INFO, "message in multiple "
+ "I frames (last message)\n");
+ rc = send_dl_l3(PRIM_DL_DATA,
+ PRIM_OP_INDICATION, lctx,
+ dl->rcv_buffer);
+ dl->rcv_buffer = NULL;
+ } else
+ LOGP(DLLAPD, LOGL_INFO, "message in multiple "
+ "I frames (next message)\n");
+ msgb_free(msg);
+
+ }
+ } else
+ LOGP(DLLAPD, LOGL_INFO, "I frame ignored during own receiver "
+ "busy condition\n");
+
+ /* Check for P bit */
+ if (lctx->p_f) {
+ /* 5.5.2.1 */
+ /* check if we are not in own receiver busy */
+ if (!dl->own_busy) {
+ LOGP(DLLAPD, LOGL_INFO, "we are not busy, send RR\n");
+ /* Send RR with F=1 */
+ rc = lapd_send_rr(lctx, 1, 0);
+ } else {
+ LOGP(DLLAPD, LOGL_INFO, "we are busy, send RNR\n");
+ /* Send RNR with F=1 */
+ rc = lapd_send_rnr(lctx, 1, 0);
+ }
+ } else {
+ /* 5.5.2.2 */
+ /* check if we are not in own receiver busy */
+ if (!dl->own_busy) {
+ /* NOTE: V(R) is already set above */
+ rc = lapd_send_i(lctx, __LINE__);
+ if (rc) {
+ LOGP(DLLAPD, LOGL_INFO, "we are not busy and "
+ "have no pending data, send RR\n");
+ /* Send RR with F=0 */
+ return lapd_send_rr(lctx, 0, 0);
+ }
+ /* all I or one RR is sent, we are done */
+ return 0;
+ } else {
+ LOGP(DLLAPD, LOGL_INFO, "we are busy, send RNR\n");
+ /* Send RNR with F=0 */
+ rc = lapd_send_rnr(lctx, 0, 0);
+ }
+ }
+
+ /* Send message, if possible due to acknowledged data */
+ lapd_send_i(lctx, __LINE__);
+
+ return rc;
+}
+
+/* Receive a LAPD message from L1 */
+int lapd_ph_data_ind(struct msgb *msg, struct lapd_msg_ctx *lctx)
+{
+ int rc;
+
+ switch (lctx->format) {
+ case LAPD_FORM_U:
+ rc = lapd_rx_u(msg, lctx);
+ break;
+ case LAPD_FORM_S:
+ rc = lapd_rx_s(msg, lctx);
+ break;
+ case LAPD_FORM_I:
+ rc = lapd_rx_i(msg, lctx);
+ break;
+ default:
+ LOGP(DLLAPD, LOGL_NOTICE, "unknown LAPD format\n");
+ msgb_free(msg);
+ rc = -EINVAL;
+ }
+ return rc;
+}
+
+/* L3 -> L2 */
+
+/* send unit data */
+static int lapd_udata_req(struct osmo_dlsap_prim *dp, struct lapd_msg_ctx *lctx)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ struct msgb *msg = dp->oph.msg;
+ struct lapd_msg_ctx nctx;
+
+ memcpy(&nctx, lctx, sizeof(nctx));
+ /* keep nctx.ldp */
+ /* keep nctx.sapi */
+ /* keep nctx.tei */
+ nctx.cr = dl->cr.loc2rem.cmd;
+ nctx.format = LAPD_FORM_U;
+ nctx.s_u = LAPD_U_UI;
+ /* keep nctx.p_f */
+ nctx.length = msg->len;
+ nctx.more = 0;
+
+ return dl->send_ph_data_req(&nctx, msg);
+}
+
+/* request link establishment */
+static int lapd_est_req(struct osmo_dlsap_prim *dp, struct lapd_msg_ctx *lctx)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ struct msgb *msg = dp->oph.msg;
+ struct lapd_msg_ctx nctx;
+
+ if (msg->len)
+ LOGP(DLLAPD, LOGL_INFO, "perform establishment with content "
+ "(SABM)\n");
+ else
+ LOGP(DLLAPD, LOGL_INFO, "perform normal establishm. (SABM)\n");
+
+ /* Flush send-queue */
+ /* Clear send-buffer */
+ lapd_dl_flush_send(dl);
+ /* be sure that history is empty */
+ lapd_dl_flush_hist(dl);
+
+ /* save message context for further use */
+ memcpy(&dl->lctx, lctx, sizeof(dl->lctx));
+
+ /* Discard partly received L3 message */
+ if (dl->rcv_buffer) {
+ msgb_free(dl->rcv_buffer);
+ dl->rcv_buffer = NULL;
+ }
+
+ /* assemble message */
+ memcpy(&nctx, &dl->lctx, sizeof(nctx));
+ /* keep nctx.ldp */
+ /* keep nctx.sapi */
+ /* keep nctx.tei */
+ nctx.cr = dl->cr.loc2rem.cmd;
+ nctx.format = LAPD_FORM_U;
+ nctx.s_u = (dl->use_sabme) ? LAPD_U_SABME : LAPD_U_SABM;
+ nctx.p_f = 1;
+ nctx.length = msg->len;
+ nctx.more = 0;
+
+ /* Transmit-buffer carries exactly one segment */
+ dl->tx_hist[0].msg = lapd_msgb_alloc(msg->len, "HIST");
+ msgb_put(dl->tx_hist[0].msg, msg->len);
+ if (msg->len)
+ memcpy(dl->tx_hist[0].msg->data, msg->l3h, msg->len);
+ dl->tx_hist[0].more = 0;
+ /* set Vs to 0, because it is used as index when resending SABM */
+ dl->v_send = 0;
+
+ /* Set states */
+ dl->own_busy = dl->peer_busy = 0;
+ dl->retrans_ctr = 0;
+ lapd_dl_newstate(dl, LAPD_STATE_SABM_SENT);
+
+ /* Tramsmit and start T200 */
+ dl->send_ph_data_req(&nctx, msg);
+ osmo_timer_schedule(&dl->t200, dl->t200_sec, dl->t200_usec);
+
+ return 0;
+}
+
+/* send data */
+static int lapd_data_req(struct osmo_dlsap_prim *dp, struct lapd_msg_ctx *lctx)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ struct msgb *msg = dp->oph.msg;
+
+ LOGP(DLLAPD, LOGL_INFO, "writing message to send-queue\n");
+
+ /* Write data into the send queue */
+ msgb_enqueue(&dl->send_queue, msg);
+
+ /* Send message, if possible */
+ lapd_send_i(&dl->lctx, __LINE__);
+
+ return 0;
+}
+
+/* Send next I frame from queued/buffered data */
+static int lapd_send_i(struct lapd_msg_ctx *lctx, int line)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ uint8_t k = dl->k;
+ uint8_t h;
+ struct msgb *msg;
+ int length, left;
+ int rc = - 1; /* we sent nothing */
+ struct lapd_msg_ctx nctx;
+
+
+ LOGP(DLLAPD, LOGL_INFO, "%s() called from line %d\n", __func__, line);
+
+ next_frame:
+
+ if (dl->peer_busy) {
+ LOGP(DLLAPD, LOGL_INFO, "peer busy, not sending\n");
+ return rc;
+ }
+
+ if (dl->state == LAPD_STATE_TIMER_RECOV) {
+ LOGP(DLLAPD, LOGL_INFO, "timer recovery, not sending\n");
+ return rc;
+ }
+
+ /* If the send state variable V(S) is equal to V(A) plus k
+ * (where k is the maximum number of outstanding I frames - see
+ * subclause 5.8.4), the data link layer entity shall not transmit any
+ * new I frames, but shall retransmit an I frame as a result
+ * of the error recovery procedures as described in subclauses 5.5.4 and
+ * 5.5.7. */
+ if (dl->v_send == add_mod(dl->v_ack, k, dl->v_range)) {
+ LOGP(DLLAPD, LOGL_INFO, "k frames outstanding, not sending "
+ "more (k=%u V(S)=%u V(A)=%u)\n", k, dl->v_send,
+ dl->v_ack);
+ return rc;
+ }
+
+ h = do_mod(dl->v_send, dl->range_hist);
+
+ /* if we have no tx_hist yet, we create it */
+ if (!dl->tx_hist[h].msg) {
+ /* Get next message into send-buffer, if any */
+ if (!dl->send_buffer) {
+ next_message:
+ dl->send_out = 0;
+ dl->send_buffer = msgb_dequeue(&dl->send_queue);
+ /* No more data to be sent */
+ if (!dl->send_buffer)
+ return rc;
+ LOGP(DLLAPD, LOGL_INFO, "get message from "
+ "send-queue\n");
+ }
+
+ /* How much is left in the send-buffer? */
+ left = msgb_l3len(dl->send_buffer) - dl->send_out;
+ /* Segment, if data exceeds N201 */
+ length = left;
+ if (length > lctx->n201)
+ length = lctx->n201;
+ LOGP(DLLAPD, LOGL_INFO, "msg-len %d sent %d left %d N201 %d "
+ "length %d first byte %02x\n",
+ msgb_l3len(dl->send_buffer), dl->send_out, left,
+ lctx->n201, length, dl->send_buffer->l3h[0]);
+ /* If message in send-buffer is completely sent */
+ if (left == 0) {
+ msgb_free(dl->send_buffer);
+ dl->send_buffer = NULL;
+ goto next_message;
+ }
+
+ LOGP(DLLAPD, LOGL_INFO, "send I frame %sV(S)=%d\n",
+ (left > length) ? "segment " : "", dl->v_send);
+
+ /* Create I frame (segment) and transmit-buffer content */
+ msg = lapd_msgb_alloc(length, "LAPD I");
+ msg->l3h = msgb_put(msg, length);
+ /* assemble message */
+ memcpy(&nctx, &dl->lctx, sizeof(nctx));
+ /* keep nctx.ldp */
+ /* keep nctx.sapi */
+ /* keep nctx.tei */
+ nctx.cr = dl->cr.loc2rem.cmd;
+ nctx.format = LAPD_FORM_I;
+ nctx.p_f = 0;
+ nctx.n_send = dl->v_send;
+ nctx.n_recv = dl->v_recv;
+ nctx.length = length;
+ if (left > length)
+ nctx.more = 1;
+ else
+ nctx.more = 0;
+ if (length)
+ memcpy(msg->l3h, dl->send_buffer->l3h + dl->send_out,
+ length);
+ /* store in tx_hist */
+ dl->tx_hist[h].msg = lapd_msgb_alloc(msg->len, "HIST");
+ msgb_put(dl->tx_hist[h].msg, msg->len);
+ if (length)
+ memcpy(dl->tx_hist[h].msg->data, msg->l3h, msg->len);
+ dl->tx_hist[h].more = nctx.more;
+ /* Add length to track how much is already in the tx buffer */
+ dl->send_out += length;
+ } else {
+ LOGP(DLLAPD, LOGL_INFO, "resend I frame from tx buffer "
+ "V(S)=%d\n", dl->v_send);
+
+ /* Create I frame (segment) from tx_hist */
+ length = dl->tx_hist[h].msg->len;
+ msg = lapd_msgb_alloc(length, "LAPD I resend");
+ msg->l3h = msgb_put(msg, length);
+ /* assemble message */
+ memcpy(&nctx, &dl->lctx, sizeof(nctx));
+ /* keep nctx.ldp */
+ /* keep nctx.sapi */
+ /* keep nctx.tei */
+ nctx.cr = dl->cr.loc2rem.cmd;
+ nctx.format = LAPD_FORM_I;
+ nctx.p_f = 0;
+ nctx.n_send = dl->v_send;
+ nctx.n_recv = dl->v_recv;
+ nctx.length = length;
+ nctx.more = dl->tx_hist[h].more;
+ if (length)
+ memcpy(msg->l3h, dl->tx_hist[h].msg->data, length);
+ }
+
+ /* The value of the send state variable V(S) shall be incremented by 1
+ * at the end of the transmission of the I frame */
+ dl->v_send = inc_mod(dl->v_send, dl->v_range);
+
+ /* If timer T200 is not running at the time right before transmitting a
+ * frame, when the PH-READY-TO-SEND primitive is received from the
+ * physical layer., it shall be set. */
+ if (!osmo_timer_pending(&dl->t200)) {
+ osmo_timer_schedule(&dl->t200, dl->t200_sec, dl->t200_usec);
+ /* reset Timer T203, if running */
+ if (osmo_timer_pending(&dl->t203)) {
+ LOGP(DLLAPD, LOGL_INFO, "stop T203\n");
+ osmo_timer_del(&dl->t203);
+ }
+ }
+
+ dl->send_ph_data_req(&nctx, msg);
+
+ rc = 0; /* we sent something */
+ goto next_frame;
+}
+
+/* request link suspension */
+static int lapd_susp_req(struct osmo_dlsap_prim *dp, struct lapd_msg_ctx *lctx)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ struct msgb *msg = dp->oph.msg;
+
+ LOGP(DLLAPD, LOGL_INFO, "perform suspension\n");
+
+ /* put back the send-buffer to the send-queue (first position) */
+ if (dl->send_buffer) {
+ LOGP(DLLAPD, LOGL_INFO, "put frame in sendbuffer back to "
+ "queue\n");
+ llist_add(&dl->send_buffer->list, &dl->send_queue);
+ dl->send_buffer = NULL;
+ } else
+ LOGP(DLLAPD, LOGL_INFO, "no frame in sendbuffer\n");
+
+ /* Clear transmit buffer, but keep send buffer */
+ lapd_dl_flush_tx(dl);
+ /* Stop timers */
+ if (osmo_timer_pending(&dl->t203)) {
+ LOGP(DLLAPD, LOGL_INFO, "stop T203\n");
+ osmo_timer_del(&dl->t203);
+ }
+ osmo_timer_del(&dl->t200);
+
+ msgb_free(msg);
+
+ return send_dl_simple(PRIM_DL_SUSP, PRIM_OP_CONFIRM, &dl->lctx);
+}
+
+/* requesst resume or reconnect of link */
+static int lapd_res_req(struct osmo_dlsap_prim *dp, struct lapd_msg_ctx *lctx)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ struct msgb *msg = dp->oph.msg;
+ struct lapd_msg_ctx nctx;
+
+ LOGP(DLLAPD, LOGL_INFO, "perform re-establishment (SABM) length=%d\n",
+ msg->len);
+
+ /* be sure that history is empty */
+ lapd_dl_flush_hist(dl);
+
+ /* save message context for further use */
+ memcpy(&dl->lctx, lctx, sizeof(dl->lctx));
+
+ /* Replace message in the send-buffer (reconnect) */
+ if (dl->send_buffer)
+ msgb_free(dl->send_buffer);
+ dl->send_out = 0;
+ if (msg && msg->len) {
+ /* Write data into the send buffer, to be sent first */
+ dl->send_buffer = msg;
+ }
+
+ /* Discard partly received L3 message */
+ if (dl->rcv_buffer) {
+ msgb_free(dl->rcv_buffer);
+ dl->rcv_buffer = NULL;
+ }
+
+ /* Create new msgb (old one is now free) */
+ msg = lapd_msgb_alloc(0, "LAPD SABM");
+ msg->l3h = msg->data;
+ /* assemble message */
+ memcpy(&nctx, &dl->lctx, sizeof(nctx));
+ /* keep nctx.ldp */
+ /* keep nctx.sapi */
+ /* keep nctx.tei */
+ nctx.cr = dl->cr.loc2rem.cmd;
+ nctx.format = LAPD_FORM_U;
+ nctx.s_u = (dl->use_sabme) ? LAPD_U_SABME : LAPD_U_SABM;
+ nctx.p_f = 1;
+ nctx.length = 0;
+ nctx.more = 0;
+
+ dl->tx_hist[0].msg = lapd_msgb_alloc(msg->len, "HIST");
+ msgb_put(dl->tx_hist[0].msg, msg->len);
+ if (msg->len)
+ memcpy(dl->tx_hist[0].msg->data, msg->l3h, msg->len);
+ dl->tx_hist[0].more = 0;
+ /* set Vs to 0, because it is used as index when resending SABM */
+ dl->v_send = 0;
+
+ /* Set states */
+ dl->own_busy = dl->peer_busy = 0;
+ dl->retrans_ctr = 0;
+ lapd_dl_newstate(dl, LAPD_STATE_SABM_SENT);
+
+ /* Tramsmit and start T200 */
+ dl->send_ph_data_req(&nctx, msg);
+ osmo_timer_schedule(&dl->t200, dl->t200_sec, dl->t200_usec);
+
+ return 0;
+}
+
+/* requesst release of link */
+static int lapd_rel_req(struct osmo_dlsap_prim *dp, struct lapd_msg_ctx *lctx)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ struct msgb *msg = dp->oph.msg;
+ struct lapd_msg_ctx nctx;
+
+ /* local release */
+ if (dp->u.rel_req.mode) {
+ LOGP(DLLAPD, LOGL_INFO, "perform local release\n");
+ msgb_free(msg);
+ /* reset Timer T200 */
+ osmo_timer_del(&dl->t200);
+ /* enter idle state */
+ lapd_dl_newstate(dl, LAPD_STATE_IDLE);
+ /* flush buffers */
+ lapd_dl_flush_tx(dl);
+ lapd_dl_flush_send(dl);
+ /* send notification to L3 */
+ return send_dl_simple(PRIM_DL_REL, PRIM_OP_CONFIRM, &dl->lctx);
+ }
+
+ /* in case we are already disconnecting */
+ if (dl->state == LAPD_STATE_DISC_SENT)
+ return -EBUSY;
+
+ /* flush tx_hist */
+ lapd_dl_flush_hist(dl);
+
+ LOGP(DLLAPD, LOGL_INFO, "perform normal release (DISC)\n");
+
+ /* Push LAPD header on msgb */
+ /* assemble message */
+ memcpy(&nctx, &dl->lctx, sizeof(nctx));
+ /* keep nctx.ldp */
+ /* keep nctx.sapi */
+ /* keep nctx.tei */
+ nctx.cr = dl->cr.loc2rem.cmd;
+ nctx.format = LAPD_FORM_U;
+ nctx.s_u = LAPD_U_DISC;
+ nctx.p_f = 1;
+ nctx.length = 0;
+ nctx.more = 0;
+
+ dl->tx_hist[0].msg = lapd_msgb_alloc(msg->len, "HIST");
+ msgb_put(dl->tx_hist[0].msg, msg->len);
+ if (msg->len)
+ memcpy(dl->tx_hist[0].msg->data, msg->l3h, msg->len);
+ dl->tx_hist[0].more = 0;
+ /* set Vs to 0, because it is used as index when resending DISC */
+ dl->v_send = 0;
+
+ /* Set states */
+ dl->own_busy = dl->peer_busy = 0;
+ dl->retrans_ctr = 0;
+ lapd_dl_newstate(dl, LAPD_STATE_DISC_SENT);
+
+ /* Tramsmit and start T200 */
+ dl->send_ph_data_req(&nctx, msg);
+ osmo_timer_schedule(&dl->t200, dl->t200_sec, dl->t200_usec);
+
+ return 0;
+}
+
+/* request release of link in idle state */
+static int lapd_rel_req_idle(struct osmo_dlsap_prim *dp,
+ struct lapd_msg_ctx *lctx)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ struct msgb *msg = dp->oph.msg;
+
+ msgb_free(msg);
+
+ /* send notification to L3 */
+ return send_dl_simple(PRIM_DL_REL, PRIM_OP_CONFIRM, &dl->lctx);
+}
+
+/* statefull handling for DL SAP messages from L3 */
+static struct l2downstate {
+ uint32_t states;
+ int prim, op;
+ const char *name;
+ int (*rout) (struct osmo_dlsap_prim *dp,
+ struct lapd_msg_ctx *lctx);
+} l2downstatelist[] = {
+ /* create and send UI command */
+ {ALL_STATES,
+ PRIM_DL_UNIT_DATA, PRIM_OP_REQUEST,
+ "DL-UNIT-DATA-REQUEST", lapd_udata_req},
+
+ /* create and send SABM command */
+ {SBIT(LAPD_STATE_IDLE),
+ PRIM_DL_EST, PRIM_OP_REQUEST,
+ "DL-ESTABLISH-REQUEST", lapd_est_req},
+
+ /* create and send I command */
+ {SBIT(LAPD_STATE_MF_EST) |
+ SBIT(LAPD_STATE_TIMER_RECOV),
+ PRIM_DL_DATA, PRIM_OP_REQUEST,
+ "DL-DATA-REQUEST", lapd_data_req},
+
+ /* suspend datalink */
+ {SBIT(LAPD_STATE_MF_EST) |
+ SBIT(LAPD_STATE_TIMER_RECOV),
+ PRIM_DL_SUSP, PRIM_OP_REQUEST,
+ "DL-SUSPEND-REQUEST", lapd_susp_req},
+
+ /* create and send SABM command (resume) */
+ {SBIT(LAPD_STATE_MF_EST) |
+ SBIT(LAPD_STATE_TIMER_RECOV),
+ PRIM_DL_RES, PRIM_OP_REQUEST,
+ "DL-RESUME-REQUEST", lapd_res_req},
+
+ /* create and send SABM command (reconnect) */
+ {SBIT(LAPD_STATE_IDLE) |
+ SBIT(LAPD_STATE_MF_EST) |
+ SBIT(LAPD_STATE_TIMER_RECOV),
+ PRIM_DL_RECON, PRIM_OP_REQUEST,
+ "DL-RECONNECT-REQUEST", lapd_res_req},
+
+ /* create and send DISC command */
+ {SBIT(LAPD_STATE_SABM_SENT) |
+ SBIT(LAPD_STATE_MF_EST) |
+ SBIT(LAPD_STATE_TIMER_RECOV) |
+ SBIT(LAPD_STATE_DISC_SENT),
+ PRIM_DL_REL, PRIM_OP_REQUEST,
+ "DL-RELEASE-REQUEST", lapd_rel_req},
+
+ /* release in idle state */
+ {SBIT(LAPD_STATE_IDLE),
+ PRIM_DL_REL, PRIM_OP_REQUEST,
+ "DL-RELEASE-REQUEST", lapd_rel_req_idle},
+};
+
+#define L2DOWNSLLEN \
+ (sizeof(l2downstatelist) / sizeof(struct l2downstate))
+
+int lapd_recv_dlsap(struct osmo_dlsap_prim *dp, struct lapd_msg_ctx *lctx)
+{
+ struct lapd_datalink *dl = lctx->dl;
+ int i, supported = 0;
+ struct msgb *msg = dp->oph.msg;
+ int rc;
+
+ /* find function for current state and message */
+ for (i = 0; i < L2DOWNSLLEN; i++) {
+ if (dp->oph.primitive == l2downstatelist[i].prim
+ && dp->oph.operation == l2downstatelist[i].op) {
+ supported = 1;
+ if ((SBIT(dl->state) & l2downstatelist[i].states))
+ break;
+ }
+ }
+ if (!supported) {
+ LOGP(DLLAPD, LOGL_NOTICE, "Message %u/%u unsupported.\n",
+ dp->oph.primitive, dp->oph.operation);
+ msgb_free(msg);
+ return 0;
+ }
+ if (i == L2DOWNSLLEN) {
+ LOGP(DLLAPD, LOGL_NOTICE, "Message %u/%u unhandled at this "
+ "state %s.\n", dp->oph.primitive, dp->oph.operation,
+ lapd_state_names[dl->state]);
+ msgb_free(msg);
+ return 0;
+ }
+
+ LOGP(DLLAPD, LOGL_INFO, "Message %s received in state %s\n",
+ l2downstatelist[i].name, lapd_state_names[dl->state]);
+
+ rc = l2downstatelist[i].rout(dp, lctx);
+
+ return rc;
+}
+
diff --git a/src/gsm/lapdm.c b/src/gsm/lapdm.c
index a2212785..9e7172d6 100644
--- a/src/gsm/lapdm.c
+++ b/src/gsm/lapdm.c
@@ -1,7 +1,7 @@
/* GSM LAPDm (TS 04.06) implementation */
/* (C) 2010-2011 by Harald Welte <laforge@gnumonks.org>
- * (C) 2010 by Andreas Eversberg <jolly@eversberg.eu>
+ * (C) 2010-2011 by Andreas Eversberg <jolly@eversberg.eu>
*
* All Rights Reserved
*
@@ -27,36 +27,6 @@
/*! \file lapdm.c */
-/*!
- * Notes on Buffering: rcv_buffer, tx_queue, tx_hist, send_buffer, send_queue
- *
- * RX data is stored in the rcv_buffer (pointer). If the message is complete, it
- * is removed from rcv_buffer pointer and forwarded to L3. If the RX data is
- * received while there is an incomplete rcv_buffer, it is appended to it.
- *
- * TX data is stored in the send_queue first. When transmitting a frame,
- * the first message in the send_queue is moved to the send_buffer. There it
- * resides until all fragments are acknowledged. Fragments to be sent by I
- * frames are stored in the tx_hist buffer for resend, if required. Also the
- * current fragment is copied into the tx_queue. There it resides until it is
- * forwarded to layer 1.
- *
- * In case we have SAPI 0, we only have a window size of 1, so the unack-
- * nowledged message resides always in the send_buffer. In case of a suspend,
- * it can be written back to the first position of the send_queue.
- *
- * The layer 1 normally sends a PH-READY-TO-SEND. But because we use
- * asynchronous transfer between layer 1 and layer 2 (serial link), we must
- * send a frame before layer 1 reaches the right timeslot to send it. So we
- * move the tx_queue to layer 1 when there is not already a pending frame, and
- * wait until acknowledge after the frame has been sent. If we receive an
- * acknowledge, we can send the next frame from the buffer, if any.
- *
- * The moving of tx_queue to layer 1 may also trigger T200, if desired. Also it
- * will trigger next I frame, if possible.
- *
- */
-
#include <stdio.h>
#include <stdint.h>
#include <string.h>
@@ -84,6 +54,7 @@
#define LAPDm_SAPI_SMS 3
#define LAPDm_ADDR(lpd, sapi, cr) ((((lpd) & 0x3) << 5) | (((sapi) & 0x7) << 2) | (((cr) & 0x1) << 1) | 0x1)
+#define LAPDm_ADDR_LPD(addr) (((addr) >> 5) & 0x3)
#define LAPDm_ADDR_SAPI(addr) (((addr) >> 2) & 0x7)
#define LAPDm_ADDR_CR(addr) (((addr) >> 1) & 0x1)
#define LAPDm_ADDR_EA(addr) ((addr) & 0x1)
@@ -105,19 +76,11 @@
#define LAPDm_CTRL_I_Ns(ctrl) (((ctrl) & 0xE) >> 1)
#define LAPDm_CTRL_Nr(ctrl) (((ctrl) & 0xE0) >> 5)
-/* TS 04.06 Table 4 / Section 3.8.1 */
-#define LAPDm_U_SABM 0x7
-#define LAPDm_U_DM 0x3
-#define LAPDm_U_UI 0x0
-#define LAPDm_U_DISC 0x8
-#define LAPDm_U_UA 0xC
-
-#define LAPDm_S_RR 0x0
-#define LAPDm_S_RNR 0x1
-#define LAPDm_S_REJ 0x2
-
#define LAPDm_LEN(len) ((len << 2) | 0x1)
#define LAPDm_MORE 0x2
+#define LAPDm_EL 0x1
+
+#define LAPDm_U_UI 0x0
/* TS 04.06 Section 5.8.3 */
#define N201_AB_SACCH 18
@@ -137,19 +100,8 @@
#define N200_TR_FACCH_FR 34
#define N200_TR_EFACCH_FR 48
#define N200_TR_FACCH_HR 29
-/* FIXME: this depends on chan type */
-#define N200 N200_TR_SACCH
-
-#define CR_MS2BS_CMD 0
-#define CR_MS2BS_RESP 1
-#define CR_BS2MS_CMD 1
-#define CR_BS2MS_RESP 0
-
-/* Set T200 to 1 Second (OpenBTS uses 900ms) */
-#define T200 1, 0
-
-/* k value for each SAPI */
-static uint8_t k_sapi[] = {1, 1, 1, 1, 1, 1, 1, 1};
+/* FIXME: set N200 depending on chan_nr */
+#define N200 N200_TR_SDCCH
enum lapdm_format {
LAPDm_FMT_A,
@@ -159,36 +111,22 @@ enum lapdm_format {
LAPDm_FMT_B4,
};
-static void lapdm_t200_cb(void *data);
-static int rslms_send_i(struct lapdm_msg_ctx *mctx, int line);
-
-/* UTILITY FUNCTIONS */
-
-static inline uint8_t inc_mod8(uint8_t x)
-{
- return (x + 1) & 7;
-}
-
-static inline uint8_t add_mod8(uint8_t x, uint8_t y)
-{
- return (x + y) & 7;
-}
-
-static inline uint8_t sub_mod8(uint8_t x, uint8_t y)
-{
- return (x - y) & 7; /* handle negative results correctly */
-}
+static int lapdm_send_ph_data_req(struct lapd_msg_ctx *lctx, struct msgb *msg);
+static int send_rslms_dlsap(struct osmo_dlsap_prim *dp,
+ struct lapd_msg_ctx *lctx);
static void lapdm_dl_init(struct lapdm_datalink *dl,
struct lapdm_entity *entity)
{
memset(dl, 0, sizeof(*dl));
- INIT_LLIST_HEAD(&dl->send_queue);
- INIT_LLIST_HEAD(&dl->tx_queue);
- dl->state = LAPDm_STATE_IDLE;
- dl->t200.data = dl;
- dl->t200.cb = &lapdm_t200_cb;
dl->entity = entity;
+ lapd_dl_init(&dl->dl, 1, 8, 200);
+ dl->dl.reestablish = 0; /* GSM uses no reestablish */
+ dl->dl.send_ph_data_req = lapdm_send_ph_data_req;
+ dl->dl.send_dlsap = send_rslms_dlsap;
+ dl->dl.n200_est_rel = N200_EST_REL;
+ dl->dl.n200 = N200;
+ dl->dl.t203_sec = 0; dl->dl.t203_usec = 0;
}
/*! \brief initialize a LAPDm entity and all datalinks inside
@@ -215,35 +153,10 @@ void lapdm_entity_init(struct lapdm_entity *le, enum lapdm_mode mode)
void lapdm_channel_init(struct lapdm_channel *lc, enum lapdm_mode mode)
{
lapdm_entity_init(&lc->lapdm_acch, mode);
+ /* FIXME: this depends on chan type */
lapdm_entity_init(&lc->lapdm_dcch, mode);
}
-static void lapdm_dl_flush_send(struct lapdm_datalink *dl)
-{
- struct msgb *msg;
-
- /* Flush send-queue */
- while ((msg = msgb_dequeue(&dl->send_queue)))
- msgb_free(msg);
-
- /* Clear send-buffer */
- if (dl->send_buffer) {
- msgb_free(dl->send_buffer);
- dl->send_buffer = NULL;
- }
-}
-
-static void lapdm_dl_flush_tx(struct lapdm_datalink *dl)
-{
- struct msgb *msg;
- unsigned int i;
-
- while ((msg = msgb_dequeue(&dl->tx_queue)))
- msgb_free(msg);
- for (i = 0; i < 8; i++)
- dl->tx_length[i] = 0;
-}
-
/*! \brief flush and release all resoures in LAPDm entity */
void lapdm_entity_exit(struct lapdm_entity *le)
{
@@ -252,10 +165,7 @@ void lapdm_entity_exit(struct lapdm_entity *le)
for (i = 0; i < ARRAY_SIZE(le->datalink); i++) {
dl = &le->datalink[i];
- lapdm_dl_flush_tx(dl);
- lapdm_dl_flush_send(dl);
- if (dl->rcv_buffer)
- msgb_free(dl->rcv_buffer);
+ lapd_dl_exit(&dl->dl);
}
}
@@ -270,14 +180,6 @@ void lapdm_channel_exit(struct lapdm_channel *lc)
lapdm_entity_exit(&lc->lapdm_dcch);
}
-static void lapdm_dl_newstate(struct lapdm_datalink *dl, uint32_t state)
-{
- LOGP(DLLAPDM, LOGL_INFO, "new state %s -> %s\n",
- lapdm_state_names[dl->state], lapdm_state_names[state]);
-
- dl->state = state;
-}
-
static struct lapdm_datalink *datalink_for_sapi(struct lapdm_entity *le, uint8_t sapi)
{
switch (sapi) {
@@ -305,7 +207,7 @@ static void lapdm_pad_msgb(struct msgb *msg, uint8_t n201)
uint8_t *data;
if (pad_len < 0) {
- LOGP(DLLAPDM, LOGL_ERROR,
+ LOGP(DLLAPD, LOGL_ERROR,
"cannot pad message that is already too big!\n");
return;
}
@@ -328,17 +230,17 @@ static int rslms_sendmsg(struct msgb *msg, struct lapdm_entity *le)
/* write a frame into the tx queue */
static int tx_ph_data_enqueue(struct lapdm_datalink *dl, struct msgb *msg,
- uint8_t chan_nr, uint8_t link_id, uint8_t n201)
+ uint8_t chan_nr, uint8_t link_id, uint8_t pad)
{
struct lapdm_entity *le = dl->entity;
struct osmo_phsap_prim pp;
/* if there is a pending message, queue it */
if (le->tx_pending || le->flags & LAPDM_ENT_F_POLLING_ONLY) {
- *msgb_push(msg, 1) = n201;
+ *msgb_push(msg, 1) = pad;
*msgb_push(msg, 1) = link_id;
*msgb_push(msg, 1) = chan_nr;
- msgb_enqueue(&dl->tx_queue, msg);
+ msgb_enqueue(&dl->dl.tx_queue, msg);
return -EBUSY;
}
@@ -349,7 +251,7 @@ static int tx_ph_data_enqueue(struct lapdm_datalink *dl, struct msgb *msg,
/* send the frame now */
le->tx_pending = 0; /* disabled flow control */
- lapdm_pad_msgb(msg, n201);
+ lapdm_pad_msgb(msg, pad);
return le->l1_prim_cb(&pp.oph, le->l1_ctx);
}
@@ -366,7 +268,7 @@ static struct msgb *tx_dequeue_msgb(struct lapdm_entity *le)
/* next */
i = (i + 1) % n;
dl = &le->datalink[i];
- if ((msg = msgb_dequeue(&dl->tx_queue)))
+ if ((msg = msgb_dequeue(&dl->dl.tx_queue)))
break;
} while (i != last);
@@ -383,7 +285,7 @@ static struct msgb *tx_dequeue_msgb(struct lapdm_entity *le)
int lapdm_phsap_dequeue_prim(struct lapdm_entity *le, struct osmo_phsap_prim *pp)
{
struct msgb *msg;
- uint8_t n201;
+ uint8_t pad;
msg = tx_dequeue_msgb(le);
if (!msg)
@@ -398,11 +300,11 @@ int lapdm_phsap_dequeue_prim(struct lapdm_entity *le, struct osmo_phsap_prim *pp
msgb_pull(msg, 1);
pp->u.data.link_id = *msg->data;
msgb_pull(msg, 1);
- n201 = *msg->data;
+ pad = *msg->data;
msgb_pull(msg, 1);
/* Pad the frame, we can transmit now */
- lapdm_pad_msgb(msg, n201);
+ lapdm_pad_msgb(msg, pad);
return 0;
}
@@ -486,1142 +388,161 @@ static int rsl_rll_error(uint8_t cause, struct lapdm_msg_ctx *mctx)
{
struct msgb *msg;
- LOGP(DLLAPDM, LOGL_NOTICE, "sending MDL-ERROR-IND %d\n", cause);
+ LOGP(DLLAPD, LOGL_NOTICE, "sending MDL-ERROR-IND %d\n", cause);
msg = rsl_rll_simple(RSL_MT_ERROR_IND, mctx->chan_nr, mctx->link_id, 1);
+ msg->l2h = msgb_put(msg, sizeof(struct abis_rsl_rll_hdr));
msgb_tlv_put(msg, RSL_IE_RLM_CAUSE, 1, &cause);
return rslms_sendmsg(msg, mctx->dl->entity);
}
-static int check_length_ind(struct lapdm_msg_ctx *mctx, uint8_t length_ind)
-{
- if (!(length_ind & 0x01)) {
- /* G.4.1 If the EL bit is set to "0", an MDL-ERROR-INDICATION
- * primitive with cause "frame not implemented" is sent to the
- * mobile management entity. */
- LOGP(DLLAPDM, LOGL_NOTICE,
- "we don't support multi-octet length\n");
- rsl_rll_error(RLL_CAUSE_FRM_UNIMPL, mctx);
- return -EINVAL;
- }
- return 0;
-}
-
-static int lapdm_send_resend(struct lapdm_datalink *dl)
-{
- struct msgb *msg = msgb_alloc_headroom(23+10, 10, "LAPDm resend");
- int length;
-
- /* Resend SABM/DISC from tx_hist */
- length = dl->tx_length[0];
- msg->l2h = msgb_put(msg, length);
- memcpy(msg->l2h, dl->tx_hist[dl->V_send], length);
-
- return tx_ph_data_enqueue(dl, msg, dl->mctx.chan_nr, dl->mctx.link_id,
- dl->mctx.n201);
-}
-
-static int lapdm_send_ua(struct lapdm_msg_ctx *mctx, uint8_t len, uint8_t *data)
+/* DLSAP L2 -> L3 (RSLms) */
+static int send_rslms_dlsap(struct osmo_dlsap_prim *dp,
+ struct lapd_msg_ctx *lctx)
{
- uint8_t sapi = mctx->link_id & 7;
- uint8_t f_bit = LAPDm_CTRL_PF_BIT(mctx->ctrl);
- struct msgb *msg = msgb_alloc_headroom(23+10, 10, "LAPDm UA");
- struct lapdm_entity *le = mctx->dl->entity;
-
- msg->l2h = msgb_put(msg, 3 + len);
- msg->l2h[0] = LAPDm_ADDR(LAPDm_LPD_NORMAL, sapi, le->cr.loc2rem.resp);
- msg->l2h[1] = LAPDm_CTRL_U(LAPDm_U_UA, f_bit);
- msg->l2h[2] = LAPDm_LEN(len);
- if (len)
- memcpy(msg->l2h + 3, data, len);
-
- return tx_ph_data_enqueue(mctx->dl, msg, mctx->chan_nr, mctx->link_id,
- mctx->n201);
-}
-
-static int lapdm_send_dm(struct lapdm_msg_ctx *mctx)
-{
- uint8_t sapi = mctx->link_id & 7;
- uint8_t f_bit = LAPDm_CTRL_PF_BIT(mctx->ctrl);
- struct msgb *msg = msgb_alloc_headroom(23+10, 10, "LAPDm DM");
- struct lapdm_entity *le = mctx->dl->entity;
-
- msg->l2h = msgb_put(msg, 3);
- msg->l2h[0] = LAPDm_ADDR(LAPDm_LPD_NORMAL, sapi, le->cr.loc2rem.resp);
- msg->l2h[1] = LAPDm_CTRL_U(LAPDm_U_DM, f_bit);
- msg->l2h[2] = 0;
-
- return tx_ph_data_enqueue(mctx->dl, msg, mctx->chan_nr, mctx->link_id,
- mctx->n201);
-}
-
-static int lapdm_send_rr(struct lapdm_msg_ctx *mctx, uint8_t f_bit)
-{
- uint8_t sapi = mctx->link_id & 7;
- struct msgb *msg = msgb_alloc_headroom(23+10, 10, "LAPDm RR");
- struct lapdm_entity *le = mctx->dl->entity;
-
- msg->l2h = msgb_put(msg, 3);
- msg->l2h[0] = LAPDm_ADDR(LAPDm_LPD_NORMAL, sapi, le->cr.loc2rem.resp);
- msg->l2h[1] = LAPDm_CTRL_S(mctx->dl->V_recv, LAPDm_S_RR, f_bit);
- msg->l2h[2] = LAPDm_LEN(0);
-
- return tx_ph_data_enqueue(mctx->dl, msg, mctx->chan_nr, mctx->link_id,
- mctx->n201);
-}
-
-static int lapdm_send_rnr(struct lapdm_msg_ctx *mctx, uint8_t f_bit)
-{
- uint8_t sapi = mctx->link_id & 7;
- struct msgb *msg = msgb_alloc_headroom(23+10, 10, "LAPDm RNR");
- struct lapdm_entity *le = mctx->dl->entity;
-
- msg->l2h = msgb_put(msg, 3);
- msg->l2h[0] = LAPDm_ADDR(LAPDm_LPD_NORMAL, sapi, le->cr.loc2rem.resp);
- msg->l2h[1] = LAPDm_CTRL_S(mctx->dl->V_recv, LAPDm_S_RNR, f_bit);
- msg->l2h[2] = LAPDm_LEN(0);
-
- return tx_ph_data_enqueue(mctx->dl, msg, mctx->chan_nr, mctx->link_id,
- mctx->n201);
-}
-
-static int lapdm_send_rej(struct lapdm_msg_ctx *mctx, uint8_t f_bit)
-{
- uint8_t sapi = mctx->link_id & 7;
- struct msgb *msg = msgb_alloc_headroom(23+10, 10, "LAPDm REJ");
- struct lapdm_entity *le = mctx->dl->entity;
-
- msg->l2h = msgb_put(msg, 3);
- msg->l2h[0] = LAPDm_ADDR(LAPDm_LPD_NORMAL, sapi, le->cr.loc2rem.resp);
- msg->l2h[1] = LAPDm_CTRL_S(mctx->dl->V_recv, LAPDm_S_REJ, f_bit);
- msg->l2h[2] = LAPDm_LEN(0);
-
- return tx_ph_data_enqueue(mctx->dl, msg, mctx->chan_nr, mctx->link_id,
- mctx->n201);
-}
-
-/* Timer callback on T200 expiry */
-static void lapdm_t200_cb(void *data)
-{
- struct lapdm_datalink *dl = data;
-
- LOGP(DLLAPDM, LOGL_INFO, "lapdm_t200_cb(%p) state=%u\n", dl, dl->state);
-
- switch (dl->state) {
- case LAPDm_STATE_SABM_SENT:
- /* 5.4.1.3 */
- if (dl->retrans_ctr + 1 >= N200_EST_REL + 1) {
- /* send RELEASE INDICATION to L3 */
- send_rll_simple(RSL_MT_REL_IND, &dl->mctx);
- /* send MDL ERROR INIDCATION to L3 */
- rsl_rll_error(RLL_CAUSE_T200_EXPIRED, &dl->mctx);
- /* flush tx buffers */
- lapdm_dl_flush_tx(dl);
- lapdm_dl_flush_send(dl);
- /* go back to idle state */
- lapdm_dl_newstate(dl, LAPDm_STATE_IDLE);
- /* NOTE: we must not change any other states or buffers
- * and queues, since we may reconnect after handover
- * failure. the buffered messages is replaced there */
+ struct lapd_datalink *dl = lctx->dl;
+ struct lapdm_datalink *mdl =
+ container_of(dl, struct lapdm_datalink, dl);
+ struct lapdm_msg_ctx *mctx = &mdl->mctx;
+ uint8_t rll_msg = 0;
+
+ switch (dp->oph.primitive) {
+ case PRIM_DL_EST:
+ switch (dp->oph.operation) {
+ case PRIM_OP_INDICATION:
+ rll_msg = RSL_MT_EST_IND;
break;
- }
- /* retransmit SABM command */
- lapdm_send_resend(dl);
- /* increment re-transmission counter */
- dl->retrans_ctr++;
- /* restart T200 (PH-READY-TO-SEND) */
- osmo_timer_schedule(&dl->t200, T200);
- break;
- case LAPDm_STATE_DISC_SENT:
- /* 5.4.4.3 */
- if (dl->retrans_ctr + 1 >= N200_EST_REL + 1) {
- /* send RELEASE INDICATION to L3 */
- send_rll_simple(RSL_MT_REL_CONF, &dl->mctx);
- /* send MDL ERROR INIDCATION to L3 */
- rsl_rll_error(RLL_CAUSE_T200_EXPIRED, &dl->mctx);
- /* flush buffers */
- lapdm_dl_flush_tx(dl);
- lapdm_dl_flush_send(dl);
- /* go back to idle state */
- lapdm_dl_newstate(dl, LAPDm_STATE_IDLE);
- /* NOTE: we must not change any other states or buffers
- * and queues, since we may reconnect after handover
- * failure. the buffered messages is replaced there */
+ case PRIM_OP_CONFIRM:
+ rll_msg = RSL_MT_EST_CONF;
break;
- }
- /* retransmit DISC command */
- lapdm_send_resend(dl);
- /* increment re-transmission counter */
- dl->retrans_ctr++;
- /* restart T200 (PH-READY-TO-SEND) */
- osmo_timer_schedule(&dl->t200, T200);
- break;
- case LAPDm_STATE_MF_EST:
- /* 5.5.7 */
- dl->retrans_ctr = 0;
- lapdm_dl_newstate(dl, LAPDm_STATE_TIMER_RECOV);
- /* fall through */
- case LAPDm_STATE_TIMER_RECOV:
- dl->retrans_ctr++;
- if (dl->retrans_ctr < N200) {
- /* retransmit I frame (V_s-1) with P=1, if any */
- if (dl->tx_length[sub_mod8(dl->V_send, 1)]) {
- struct msgb *msg;
- int length;
-
- LOGP(DLLAPDM, LOGL_INFO, "retransmit last frame "
- "V(S)=%d\n", sub_mod8(dl->V_send, 1));
- /* Create I frame (segment) from tx_hist */
- length = dl->tx_length[sub_mod8(dl->V_send, 1)];
- msg = msgb_alloc_headroom(23+10, 10, "LAPDm I");
- msg->l2h = msgb_put(msg, length);
- memcpy(msg->l2h,
- dl->tx_hist[sub_mod8(dl->V_send, 1)],
- length);
- msg->l2h[1] = LAPDm_CTRL_I(dl->V_recv,
- sub_mod8(dl->V_send, 1), 1); /* P=1 */
- tx_ph_data_enqueue(dl, msg, dl->mctx.chan_nr,
- dl->mctx.link_id, dl->mctx.n201);
- } else {
- /* OR send appropriate supervision frame with P=1 */
- if (!dl->own_busy && !dl->seq_err_cond) {
- lapdm_send_rr(&dl->mctx, 1);
- /* NOTE: In case of sequence error
- * condition, the REJ frame has been
- * transmitted when entering the
- * condition, so it has not be done
- * here
- */
- } else if (dl->own_busy) {
- lapdm_send_rnr(&dl->mctx, 1);
- } else {
- LOGP(DLLAPDM, LOGL_INFO, "unhandled, "
- "pls. fix\n");
- }
- }
- /* restart T200 (PH-READY-TO-SEND) */
- osmo_timer_schedule(&dl->t200, T200);
- } else {
- /* send MDL ERROR INIDCATION to L3 */
- rsl_rll_error(RLL_CAUSE_T200_EXPIRED, &dl->mctx);
+ default:
+ ;
}
break;
- default:
- LOGP(DLLAPDM, LOGL_INFO, "T200 expired in unexpected "
- "dl->state %u\n", dl->state);
- }
-}
-
-/* 5.5.3.1: Common function to acknowlege frames up to the given N(R) value */
-static void lapdm_acknowledge(struct lapdm_msg_ctx *mctx)
-{
- struct lapdm_datalink *dl = mctx->dl;
- uint8_t nr = LAPDm_CTRL_Nr(mctx->ctrl);
- int s = 0, rej = 0, t200_reset = 0;
- int i;
-
- /* supervisory frame ? */
- if (LAPDm_CTRL_is_S(mctx->ctrl))
- s = 1;
- /* REJ frame ? */
- if (s && LAPDm_CTRL_S_BITS(mctx->ctrl) == LAPDm_S_REJ)
- rej = 1;
-
- /* Flush all transmit buffers of acknowledged frames */
- for (i = dl->V_ack; i != nr; i = inc_mod8(i)) {
- if (dl->tx_length[i]) {
- dl->tx_length[i] = 0;
- LOGP(DLLAPDM, LOGL_INFO, "ack frame %d\n", i);
- }
- }
-
- if (dl->state != LAPDm_STATE_TIMER_RECOV) {
- /* When not in the timer recovery condition, the data
- * link layer entity shall reset the timer T200 on
- * receipt of a valid I frame with N(R) higher than V(A),
- * or an REJ with an N(R) equal to V(A). */
- if ((!rej && nr != dl->V_ack)
- || (rej && nr == dl->V_ack)) {
- LOGP(DLLAPDM, LOGL_INFO, "reset t200\n");
- t200_reset = 1;
- osmo_timer_del(&dl->t200);
- /* 5.5.3.1 Note 1 + 2 imply timer recovery cond. */
- }
- /* 5.7.4: N(R) sequence error
- * N(R) is called valid, if and only if
- * (N(R)-V(A)) mod 8 <= (V(S)-V(A)) mod 8.
- */
- if (sub_mod8(nr, dl->V_ack) > sub_mod8(dl->V_send, dl->V_ack)) {
- LOGP(DLLAPDM, LOGL_NOTICE, "N(R) sequence error\n");
- rsl_rll_error(RLL_CAUSE_SEQ_ERR, mctx);
- }
- }
-
- /* V(A) shall be set to the value of N(R) */
- dl->V_ack = nr;
-
- /* If T200 has been reset by the receipt of an I, RR or RNR frame,
- * and if there are outstanding I frames, restart T200 */
- if (t200_reset && !rej) {
- if (dl->tx_length[dl->V_send - 1]) {
- LOGP(DLLAPDM, LOGL_INFO, "start T200, due to unacked I "
- "frame(s)\n");
- osmo_timer_schedule(&dl->t200, T200);
- }
- }
-}
-
-/* L1 -> L2 */
-
-/* Receive a LAPDm U (Unnumbered) message from L1 */
-static int lapdm_rx_u(struct msgb *msg, struct lapdm_msg_ctx *mctx)
-{
- struct lapdm_datalink *dl = mctx->dl;
- struct lapdm_entity *le = dl->entity;
- uint8_t length;
- int rc;
- int rsl_msg;
-
- switch (LAPDm_CTRL_U_BITS(mctx->ctrl)) {
- case LAPDm_U_SABM:
- rsl_msg = RSL_MT_EST_IND;
-
- LOGP(DLLAPDM, LOGL_INFO, "SABM received\n");
- /* 5.7.1 */
- dl->seq_err_cond = 0;
- /* G.2.2 Wrong value of the C/R bit */
- if (LAPDm_ADDR_CR(mctx->addr) == le->cr.rem2loc.resp) {
- LOGP(DLLAPDM, LOGL_NOTICE, "SABM response error\n");
- msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_FRM_UNIMPL, mctx);
- return -EINVAL;
- }
-
- length = msg->l2h[2] >> 2;
- /* G.4.5 If SABM is received with L>N201 or with M bit
- * set, AN MDL-ERROR-INDICATION is sent to MM.
- */
- if ((msg->l2h[2] & LAPDm_MORE) || length + 3 > mctx->n201) {
- LOGP(DLLAPDM, LOGL_NOTICE, "SABM too large error\n");
- msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_UFRM_INC_PARAM, mctx);
- return -EIO;
- }
-
- /* Must be Format B */
- rc = check_length_ind(mctx, msg->l2h[2]);
- if (rc < 0) {
- msgb_free(msg);
- return rc;
- }
- switch (dl->state) {
- case LAPDm_STATE_IDLE:
- /* Set chan_nr and link_id for established connection */
- memset(&dl->mctx, 0, sizeof(dl->mctx));
- dl->mctx.dl = dl;
- dl->mctx.chan_nr = mctx->chan_nr;
- dl->mctx.link_id = mctx->link_id;
- dl->mctx.n201 = mctx->n201;
+ case PRIM_DL_DATA:
+ switch (dp->oph.operation) {
+ case PRIM_OP_INDICATION:
+ rll_msg = RSL_MT_DATA_IND;
break;
- case LAPDm_STATE_MF_EST:
- if (length == 0) {
- rsl_msg = RSL_MT_EST_CONF;
- break;
- }
- LOGP(DLLAPDM, LOGL_INFO, "SABM command, multiple "
- "frame established state\n");
- /* check for contention resoultion */
- if (dl->tx_hist[0][2] >> 2) {
- LOGP(DLLAPDM, LOGL_NOTICE, "SABM not allowed "
- "during contention resolution\n");
- rsl_rll_error(RLL_CAUSE_SABM_INFO_NOTALL, mctx);
- }
- msgb_free(msg);
- return 0;
- case LAPDm_STATE_DISC_SENT:
- /* 5.4.6.2 send DM with F=P */
- lapdm_send_dm(mctx);
- /* reset Timer T200 */
- osmo_timer_del(&dl->t200);
- msgb_free(msg);
- return send_rll_simple(RSL_MT_REL_CONF, mctx);
default:
- lapdm_send_ua(mctx, length, msg->l2h + 3);
- msgb_free(msg);
- return 0;
- }
- /* send UA response */
- lapdm_send_ua(mctx, length, msg->l2h + 3);
- /* set Vs, Vr and Va to 0 */
- dl->V_send = dl->V_recv = dl->V_ack = 0;
- /* clear tx_hist */
- dl->tx_length[0] = 0;
- /* enter multiple-frame-established state */
- lapdm_dl_newstate(dl, LAPDm_STATE_MF_EST);
- /* send notification to L3 */
- if (length == 0) {
- /* 5.4.1.2 Normal establishment procedures */
- rc = send_rll_simple(rsl_msg, mctx);
- msgb_free(msg);
- } else {
- /* 5.4.1.4 Contention resolution establishment */
- msg->l3h = msg->l2h + 3;
- msgb_pull_l2h(msg);
- rc = send_rslms_rll_l3(rsl_msg, mctx, msg);
+ ;
}
break;
- case LAPDm_U_DM:
- LOGP(DLLAPDM, LOGL_INFO, "DM received\n");
- /* G.2.2 Wrong value of the C/R bit */
- if (LAPDm_ADDR_CR(mctx->addr) == le->cr.rem2loc.cmd) {
- LOGP(DLLAPDM, LOGL_NOTICE, "DM command error\n");
- msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_FRM_UNIMPL, mctx);
- return -EINVAL;
- }
- if (!LAPDm_CTRL_PF_BIT(mctx->ctrl)) {
- /* 5.4.1.2 DM responses with the F bit set to "0"
- * shall be ignored.
- */
- msgb_free(msg);
- return 0;
- }
- switch (dl->state) {
- case LAPDm_STATE_SABM_SENT:
- break;
- case LAPDm_STATE_MF_EST:
- if (LAPDm_CTRL_PF_BIT(mctx->ctrl) == 1) {
- LOGP(DLLAPDM, LOGL_INFO, "unsolicited DM "
- "response\n");
- rsl_rll_error(RLL_CAUSE_UNSOL_DM_RESP, mctx);
- } else {
- LOGP(DLLAPDM, LOGL_INFO, "unsolicited DM "
- "response, multiple frame established "
- "state\n");
- rsl_rll_error(RLL_CAUSE_UNSOL_DM_RESP_MF, mctx);
- }
- msgb_free(msg);
- return 0;
- case LAPDm_STATE_TIMER_RECOV:
- /* DM is normal in case PF = 1 */
- if (LAPDm_CTRL_PF_BIT(mctx->ctrl) == 0) {
- LOGP(DLLAPDM, LOGL_INFO, "unsolicited DM "
- "response, multiple frame established "
- "state\n");
- rsl_rll_error(RLL_CAUSE_UNSOL_DM_RESP_MF, mctx);
- msgb_free(msg);
- return 0;
- }
- break;
- case LAPDm_STATE_DISC_SENT:
- /* reset Timer T200 */
- osmo_timer_del(&dl->t200);
- /* go to idle state */
- lapdm_dl_flush_tx(dl);
- lapdm_dl_flush_send(dl);
- lapdm_dl_newstate(dl, LAPDm_STATE_IDLE);
- rc = send_rll_simple(RSL_MT_REL_CONF, mctx);
- msgb_free(msg);
- return 0;
- case LAPDm_STATE_IDLE:
- /* 5.4.5 all other frame types shall be discarded */
+ case PRIM_DL_UNIT_DATA:
+ switch (dp->oph.operation) {
+ case PRIM_OP_INDICATION:
+ return send_rslms_rll_l3_ui(mctx, dp->oph.msg);
default:
- LOGP(DLLAPDM, LOGL_INFO, "unsolicited DM response! "
- "(discarding)\n");
- msgb_free(msg);
- return 0;
+ ;
}
- /* reset T200 */
- osmo_timer_del(&dl->t200);
- rc = send_rll_simple(RSL_MT_REL_IND, mctx);
- msgb_free(msg);
break;
- case LAPDm_U_UI:
- LOGP(DLLAPDM, LOGL_INFO, "UI received\n");
- /* G.2.2 Wrong value of the C/R bit */
- if (LAPDm_ADDR_CR(mctx->addr) == le->cr.rem2loc.resp) {
- LOGP(DLLAPDM, LOGL_NOTICE, "UI indicates response "
- "error\n");
- msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_FRM_UNIMPL, mctx);
- return -EINVAL;
- }
-
- length = msg->l2h[2] >> 2;
- /* FIXME: G.4.5 If UI is received with L>N201 or with M bit
- * set, AN MDL-ERROR-INDICATION is sent to MM.
- */
-
- if (mctx->lapdm_fmt == LAPDm_FMT_B4) {
- length = N201_B4;
- msg->l3h = msg->l2h + 2;
- } else {
- rc = check_length_ind(mctx, msg->l2h[2]);
- if (rc < 0) {
- msgb_free(msg);
- return rc;
- }
- length = msg->l2h[2] >> 2;
- msg->l3h = msg->l2h + 3;
- }
- /* do some length checks */
- if (length == 0) {
- /* 5.3.3 UI frames received with the length indicator
- * set to "0" shall be ignored
- */
- LOGP(DLLAPDM, LOGL_INFO, "length=0 (discarding)\n");
- msgb_free(msg);
- return 0;
- }
- switch (LAPDm_ADDR_SAPI(mctx->addr)) {
- case LAPDm_SAPI_NORMAL:
- case LAPDm_SAPI_SMS:
+ case PRIM_DL_REL:
+ switch (dp->oph.operation) {
+ case PRIM_OP_INDICATION:
+ rll_msg = RSL_MT_REL_IND;
+ break;
+ case PRIM_OP_CONFIRM:
+ rll_msg = RSL_MT_REL_CONF;
break;
default:
- /* 5.3.3 UI frames with invalid SAPI values shall be
- * discarded
- */
- LOGP(DLLAPDM, LOGL_INFO, "sapi=%u (discarding)\n",
- LAPDm_ADDR_SAPI(mctx->addr));
- msgb_free(msg);
- return 0;
+ ;
}
- msgb_pull_l2h(msg);
- rc = send_rslms_rll_l3_ui(mctx, msg);
break;
- case LAPDm_U_DISC:
- rsl_msg = RSL_MT_REL_IND;
-
- LOGP(DLLAPDM, LOGL_INFO, "DISC received\n");
- /* flush buffers */
- lapdm_dl_flush_tx(dl);
- lapdm_dl_flush_send(dl);
- /* 5.7.1 */
- dl->seq_err_cond = 0;
- /* G.2.2 Wrong value of the C/R bit */
- if (LAPDm_ADDR_CR(mctx->addr) == le->cr.rem2loc.resp) {
- LOGP(DLLAPDM, LOGL_NOTICE, "DISC response error\n");
- msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_FRM_UNIMPL, mctx);
- return -EINVAL;
- }
- length = msg->l2h[2] >> 2;
- if (length > 0 || msg->l2h[2] & 0x02) {
- /* G.4.4 If a DISC or DM frame is received with L>0 or
- * with the M bit set to "1", an MDL-ERROR-INDICATION
- * primitive with cause "U frame with incorrect
- * parameters" is sent to the mobile management entity.
- */
- LOGP(DLLAPDM, LOGL_NOTICE,
- "U frame iwth incorrect parameters ");
- msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_UFRM_INC_PARAM, mctx);
- return -EIO;
- }
- switch (dl->state) {
- case LAPDm_STATE_IDLE:
- LOGP(DLLAPDM, LOGL_INFO, "DISC in idle state\n");
- /* send DM with F=P */
- msgb_free(msg);
- return lapdm_send_dm(mctx);
- case LAPDm_STATE_SABM_SENT:
- LOGP(DLLAPDM, LOGL_INFO, "DISC in SABM state\n");
- /* 5.4.6.2 send DM with F=P */
- lapdm_send_dm(mctx);
- /* reset Timer T200 */
- osmo_timer_del(&dl->t200);
- msgb_free(msg);
- return send_rll_simple(RSL_MT_REL_IND, mctx);
- case LAPDm_STATE_MF_EST:
- case LAPDm_STATE_TIMER_RECOV:
- LOGP(DLLAPDM, LOGL_INFO, "DISC in est state\n");
- break;
- case LAPDm_STATE_DISC_SENT:
- LOGP(DLLAPDM, LOGL_INFO, "DISC in disc state\n");
- rsl_msg = RSL_MT_REL_CONF;
+ case PRIM_DL_SUSP:
+ switch (dp->oph.operation) {
+ case PRIM_OP_CONFIRM:
+ rll_msg = RSL_MT_SUSP_CONF;
break;
default:
- lapdm_send_ua(mctx, length, msg->l2h + 3);
- msgb_free(msg);
- return 0;
+ ;
}
- /* send UA response */
- lapdm_send_ua(mctx, length, msg->l2h + 3);
- /* reset Timer T200 */
- osmo_timer_del(&dl->t200);
- /* enter idle state */
- lapdm_dl_flush_tx(dl);
- lapdm_dl_flush_send(dl);
- lapdm_dl_newstate(dl, LAPDm_STATE_IDLE);
- /* send notification to L3 */
- rc = send_rll_simple(rsl_msg, mctx);
- msgb_free(msg);
break;
- case LAPDm_U_UA:
- LOGP(DLLAPDM, LOGL_INFO, "UA received\n");
- /* G.2.2 Wrong value of the C/R bit */
- if (LAPDm_ADDR_CR(mctx->addr) == le->cr.rem2loc.cmd) {
- LOGP(DLLAPDM, LOGL_NOTICE, "UA indicates command "
- "error\n");
- msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_FRM_UNIMPL, mctx);
- return -EINVAL;
- }
-
- length = msg->l2h[2] >> 2;
- /* G.4.5 If UA is received with L>N201 or with M bit
- * set, AN MDL-ERROR-INDICATION is sent to MM.
- */
- if ((msg->l2h[2] & LAPDm_MORE) || length + 3 > mctx->n201) {
- LOGP(DLLAPDM, LOGL_NOTICE, "UA too large error\n");
- msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_UFRM_INC_PARAM, mctx);
- return -EIO;
- }
-
- if (!LAPDm_CTRL_PF_BIT(mctx->ctrl)) {
- /* 5.4.1.2 A UA response with the F bit set to "0"
- * shall be ignored.
- */
- LOGP(DLLAPDM, LOGL_INFO, "F=0 (discarding)\n");
- msgb_free(msg);
- return 0;
- }
- switch (dl->state) {
- case LAPDm_STATE_SABM_SENT:
- break;
- case LAPDm_STATE_MF_EST:
- case LAPDm_STATE_TIMER_RECOV:
- LOGP(DLLAPDM, LOGL_INFO, "unsolicited UA response! "
- "(discarding)\n");
- rsl_rll_error(RLL_CAUSE_UNSOL_UA_RESP, mctx);
- msgb_free(msg);
- return 0;
- case LAPDm_STATE_DISC_SENT:
- LOGP(DLLAPDM, LOGL_INFO, "UA in disconnect state\n");
- /* reset Timer T200 */
- osmo_timer_del(&dl->t200);
- /* go to idle state */
- lapdm_dl_flush_tx(dl);
- lapdm_dl_flush_send(dl);
- lapdm_dl_newstate(dl, LAPDm_STATE_IDLE);
- rc = send_rll_simple(RSL_MT_REL_CONF, mctx);
- msgb_free(msg);
+ case PRIM_MDL_ERROR:
+ switch (dp->oph.operation) {
+ case PRIM_OP_INDICATION:
+ rsl_rll_error(dp->u.error_ind.cause, mctx);
+ if (dp->oph.msg)
+ msgb_free(dp->oph.msg);
return 0;
- case LAPDm_STATE_IDLE:
- /* 5.4.5 all other frame types shall be discarded */
default:
- LOGP(DLLAPDM, LOGL_INFO, "unsolicited UA response! "
- "(discarding)\n");
- msgb_free(msg);
- return 0;
- }
- LOGP(DLLAPDM, LOGL_INFO, "UA in SABM state\n");
- /* reset Timer T200 */
- osmo_timer_del(&dl->t200);
- /* compare UA with SABME if contention resolution is applied */
- if (dl->tx_hist[0][2] >> 2) {
- rc = check_length_ind(mctx, msg->l2h[2]);
- if (rc < 0) {
- rc = send_rll_simple(RSL_MT_REL_IND, mctx);
- msgb_free(msg);
- /* go to idle state */
- lapdm_dl_flush_tx(dl);
- lapdm_dl_flush_send(dl);
- lapdm_dl_newstate(dl, LAPDm_STATE_IDLE);
- return 0;
- }
- length = msg->l2h[2] >> 2;
- if (length != (dl->tx_hist[0][2] >> 2)
- || !!memcmp(dl->tx_hist[0] + 3, msg->l2h + 3,
- length)) {
- LOGP(DLLAPDM, LOGL_INFO, "**** UA response "
- "mismatches ****\n");
- rc = send_rll_simple(RSL_MT_REL_IND, mctx);
- msgb_free(msg);
- /* go to idle state */
- lapdm_dl_flush_tx(dl);
- lapdm_dl_flush_send(dl);
- lapdm_dl_newstate(dl, LAPDm_STATE_IDLE);
- return 0;
- }
+ ;
}
- /* set Vs, Vr and Va to 0 */
- dl->V_send = dl->V_recv = dl->V_ack = 0;
- /* clear tx_hist */
- dl->tx_length[0] = 0;
- /* enter multiple-frame-established state */
- lapdm_dl_newstate(dl, LAPDm_STATE_MF_EST);
- /* send outstanding frames, if any (resume / reconnect) */
- rslms_send_i(mctx, __LINE__);
- /* send notification to L3 */
- rc = send_rll_simple(RSL_MT_EST_CONF, mctx);
- msgb_free(msg);
break;
default:
- /* G.3.1 */
- LOGP(DLLAPDM, LOGL_NOTICE, "Unnumbered frame not allowed.\n");
- msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_FRM_UNIMPL, mctx);
- return -EINVAL;
+ ;
}
- return rc;
-}
-/* Receive a LAPDm S (Supervisory) message from L1 */
-static int lapdm_rx_s(struct msgb *msg, struct lapdm_msg_ctx *mctx)
-{
- struct lapdm_datalink *dl = mctx->dl;
- struct lapdm_entity *le = dl->entity;
- uint8_t length;
-
- length = msg->l2h[2] >> 2;
- if (length > 0 || msg->l2h[2] & 0x02) {
- /* G.4.3 If a supervisory frame is received with L>0 or
- * with the M bit set to "1", an MDL-ERROR-INDICATION
- * primitive with cause "S frame with incorrect
- * parameters" is sent to the mobile management entity. */
- LOGP(DLLAPDM, LOGL_NOTICE,
- "S frame with incorrect parameters\n");
- msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_SFRM_INC_PARAM, mctx);
- return -EIO;
+ if (!rll_msg) {
+ LOGP(DLLAPD, LOGL_ERROR, "Unsupported op %d, prim %d. Please "
+ "fix!\n", dp->oph.primitive, dp->oph.operation);
+ return -EINVAL;
}
- if (LAPDm_ADDR_CR(mctx->addr) == le->cr.rem2loc.resp
- && LAPDm_CTRL_PF_BIT(mctx->ctrl)
- && dl->state != LAPDm_STATE_TIMER_RECOV) {
- /* 5.4.2.2: Inidcate error on supervisory reponse F=1 */
- LOGP(DLLAPDM, LOGL_NOTICE, "S frame response with F=1 error\n");
- rsl_rll_error(RLL_CAUSE_UNSOL_SPRV_RESP, mctx);
- }
+ if (!dp->oph.msg)
+ return send_rll_simple(rll_msg, mctx);
- switch (dl->state) {
- case LAPDm_STATE_IDLE:
- /* if P=1, respond DM with F=1 (5.2.2) */
- /* 5.4.5 all other frame types shall be discarded */
- if (LAPDm_CTRL_PF_BIT(mctx->ctrl))
- lapdm_send_dm(mctx); /* F=P */
- /* fall though */
- case LAPDm_STATE_SABM_SENT:
- case LAPDm_STATE_DISC_SENT:
- LOGP(DLLAPDM, LOGL_NOTICE, "S frame ignored in this state\n");
- msgb_free(msg);
- return 0;
- }
- switch (LAPDm_CTRL_S_BITS(mctx->ctrl)) {
- case LAPDm_S_RR:
- LOGP(DLLAPDM, LOGL_INFO, "RR received\n");
- /* 5.5.3.1: Acknowlege all tx frames up the the N(R)-1 */
- lapdm_acknowledge(mctx);
-
- /* 5.5.3.2 */
- if (LAPDm_ADDR_CR(mctx->addr) == le->cr.rem2loc.cmd
- && LAPDm_CTRL_PF_BIT(mctx->ctrl)) {
- if (!dl->own_busy && !dl->seq_err_cond) {
- LOGP(DLLAPDM, LOGL_NOTICE, "RR frame command "
- "with polling bit set and we are not "
- "busy, so we reply with RR frame\n");
- lapdm_send_rr(mctx, 1);
- /* NOTE: In case of sequence error condition,
- * the REJ frame has been transmitted when
- * entering the condition, so it has not be
- * done here
- */
- } else if (dl->own_busy) {
- LOGP(DLLAPDM, LOGL_NOTICE, "RR frame command "
- "with polling bit set and we are busy, "
- "so we reply with RR frame\n");
- lapdm_send_rnr(mctx, 1);
- }
- } else if (LAPDm_ADDR_CR(mctx->addr) == le->cr.rem2loc.resp
- && LAPDm_CTRL_PF_BIT(mctx->ctrl)
- && dl->state == LAPDm_STATE_TIMER_RECOV) {
- LOGP(DLLAPDM, LOGL_INFO, "RR response with F==1, "
- "and we are in timer recovery state, so "
- "we leave that state\n");
- /* V(S) to the N(R) in the RR frame */
- dl->V_send = LAPDm_CTRL_Nr(mctx->ctrl);
- /* reset Timer T200 */
- osmo_timer_del(&dl->t200);
- /* 5.5.7 Clear timer recovery condition */
- lapdm_dl_newstate(dl, LAPDm_STATE_MF_EST);
- }
- /* Send message, if possible due to acknowledged data */
- rslms_send_i(mctx, __LINE__);
+ return send_rslms_rll_l3(rll_msg, mctx, dp->oph.msg);
+}
+/* send a data frame to layer 1 */
+static int lapdm_send_ph_data_req(struct lapd_msg_ctx *lctx, struct msgb *msg)
+{
+ uint8_t l3_len = msg->tail - msg->data;
+ struct lapd_datalink *dl = lctx->dl;
+ struct lapdm_datalink *mdl =
+ container_of(dl, struct lapdm_datalink, dl);
+ struct lapdm_msg_ctx *mctx = &mdl->mctx;
+ int format = lctx->format;
+
+ /* prepend l2 header */
+ msg->l2h = msgb_push(msg, 3);
+ msg->l2h[0] = LAPDm_ADDR(lctx->lpd, lctx->sapi, lctx->cr);
+ /* EA is set here too */
+ switch (format) {
+ case LAPD_FORM_I:
+ msg->l2h[1] = LAPDm_CTRL_I(lctx->n_recv, lctx->n_send,
+ lctx->p_f);
break;
- case LAPDm_S_RNR:
- LOGP(DLLAPDM, LOGL_INFO, "RNR received\n");
- /* 5.5.3.1: Acknowlege all tx frames up the the N(R)-1 */
- lapdm_acknowledge(mctx);
-
- /* 5.5.5 */
- /* Set peer receiver busy condition */
- dl->peer_busy = 1;
-
- if (LAPDm_CTRL_PF_BIT(mctx->ctrl)) {
- if (LAPDm_ADDR_CR(mctx->addr) == le->cr.rem2loc.cmd) {
- if (!dl->own_busy) {
- LOGP(DLLAPDM, LOGL_INFO, "RNR poll "
- "command and we are not busy, "
- "so we reply with RR final "
- "response\n");
- /* Send RR with F=1 */
- lapdm_send_rr(mctx, 1);
- } else {
- LOGP(DLLAPDM, LOGL_INFO, "RNR poll "
- "command and we are busy, so "
- "we reply with RNR final "
- "response\n");
- /* Send RNR with F=1 */
- lapdm_send_rnr(mctx, 1);
- }
- } else if (dl->state == LAPDm_STATE_TIMER_RECOV) {
- LOGP(DLLAPDM, LOGL_INFO, "RNR poll response "
- "and we in timer recovery state, so "
- "we leave that state\n");
- /* 5.5.7 Clear timer recovery condition */
- lapdm_dl_newstate(dl, LAPDm_STATE_MF_EST);
- /* V(S) to the N(R) in the RNR frame */
- dl->V_send = LAPDm_CTRL_Nr(mctx->ctrl);
- }
- } else
- LOGP(DLLAPDM, LOGL_INFO, "RNR not polling/final state "
- "received\n");
-
- /* Send message, if possible due to acknowledged data */
- rslms_send_i(mctx, __LINE__);
-
+ case LAPD_FORM_S:
+ msg->l2h[1] = LAPDm_CTRL_S(lctx->n_recv, lctx->s_u, lctx->p_f);
break;
- case LAPDm_S_REJ:
- LOGP(DLLAPDM, LOGL_INFO, "REJ received\n");
- /* 5.5.3.1: Acknowlege all tx frames up the the N(R)-1 */
- lapdm_acknowledge(mctx);
-
- /* 5.5.4.1 */
- if (dl->state != LAPDm_STATE_TIMER_RECOV) {
- /* Clear an existing peer receiver busy condition */
- dl->peer_busy = 0;
- /* V(S) and V(A) to the N(R) in the REJ frame */
- dl->V_send = dl->V_ack = LAPDm_CTRL_Nr(mctx->ctrl);
- /* reset Timer T200 */
- osmo_timer_del(&dl->t200);
- /* 5.5.3.2 */
- if (LAPDm_ADDR_CR(mctx->addr) == le->cr.rem2loc.cmd
- && LAPDm_CTRL_PF_BIT(mctx->ctrl)) {
- if (!dl->own_busy && !dl->seq_err_cond) {
- LOGP(DLLAPDM, LOGL_INFO, "REJ poll "
- "command not in timer recovery "
- "state and not in own busy "
- "condition received, so we "
- "respond with RR final "
- "response\n");
- lapdm_send_rr(mctx, 1);
- /* NOTE: In case of sequence error
- * condition, the REJ frame has been
- * transmitted when entering the
- * condition, so it has not be done
- * here
- */
- } else if (dl->own_busy) {
- LOGP(DLLAPDM, LOGL_INFO, "REJ poll "
- "command not in timer recovery "
- "state and in own busy "
- "condition received, so we "
- "respond with RNR final "
- "response\n");
- lapdm_send_rnr(mctx, 1);
- }
- } else
- LOGP(DLLAPDM, LOGL_INFO, "REJ response or not "
- "polling command not in timer recovery "
- "state received\n");
- /* send MDL ERROR INIDCATION to L3 */
- if (LAPDm_ADDR_CR(mctx->addr) == le->cr.rem2loc.resp
- && LAPDm_CTRL_PF_BIT(mctx->ctrl)) {
- rsl_rll_error(RLL_CAUSE_UNSOL_SPRV_RESP, mctx);
- }
-
- } else if (LAPDm_ADDR_CR(mctx->addr) == le->cr.rem2loc.resp
- && LAPDm_CTRL_PF_BIT(mctx->ctrl)) {
- LOGP(DLLAPDM, LOGL_INFO, "REJ poll response in timer "
- "recovery state received\n");
- /* Clear an existing peer receiver busy condition */
- dl->peer_busy = 0;
- /* 5.5.7 Clear timer recovery condition */
- lapdm_dl_newstate(dl, LAPDm_STATE_MF_EST);
- /* V(S) and V(A) to the N(R) in the REJ frame */
- dl->V_send = dl->V_ack = LAPDm_CTRL_Nr(mctx->ctrl);
- /* reset Timer T200 */
- osmo_timer_del(&dl->t200);
- } else {
- /* Clear an existing peer receiver busy condition */
- dl->peer_busy = 0;
- /* V(S) and V(A) to the N(R) in the REJ frame */
- dl->V_send = dl->V_ack = LAPDm_CTRL_Nr(mctx->ctrl);
- /* 5.5.3.2 */
- if (LAPDm_ADDR_CR(mctx->addr) == le->cr.rem2loc.cmd
- && LAPDm_CTRL_PF_BIT(mctx->ctrl)) {
- if (!dl->own_busy && !dl->seq_err_cond) {
- LOGP(DLLAPDM, LOGL_INFO, "REJ poll "
- "command in timer recovery "
- "state and not in own busy "
- "condition received, so we "
- "respond with RR final "
- "response\n");
- lapdm_send_rr(mctx, 1);
- /* NOTE: In case of sequence error
- * condition, the REJ frame has been
- * transmitted when entering the
- * condition, so it has not be done
- * here
- */
- } else if (dl->own_busy) {
- LOGP(DLLAPDM, LOGL_INFO, "REJ poll "
- "command in timer recovery "
- "state and in own busy "
- "condition received, so we "
- "respond with RNR final "
- "response\n");
- lapdm_send_rnr(mctx, 1);
- }
- } else
- LOGP(DLLAPDM, LOGL_INFO, "REJ response or not "
- "polling command in timer recovery "
- "state received\n");
- }
-
- /* FIXME: 5.5.4.2 2) */
-
- /* Send message, if possible due to acknowledged data */
- rslms_send_i(mctx, __LINE__);
-
+ case LAPD_FORM_U:
+ msg->l2h[1] = LAPDm_CTRL_U(lctx->s_u, lctx->p_f);
break;
default:
- /* G.3.1 */
- LOGP(DLLAPDM, LOGL_NOTICE, "Supervisory frame not allowed.\n");
- msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_FRM_UNIMPL, mctx);
- return -EINVAL;
- }
- msgb_free(msg);
- return 0;
-}
-
-/* Receive a LAPDm I (Information) message from L1 */
-static int lapdm_rx_i(struct msgb *msg, struct lapdm_msg_ctx *mctx)
-{
- struct lapdm_datalink *dl = mctx->dl;
- struct lapdm_entity *le = dl->entity;
- //uint8_t nr = LAPDm_CTRL_Nr(mctx->ctrl);
- uint8_t ns = LAPDm_CTRL_I_Ns(mctx->ctrl);
- uint8_t length;
- int rc;
-
- LOGP(DLLAPDM, LOGL_NOTICE, "I received\n");
-
- /* G.2.2 Wrong value of the C/R bit */
- if (LAPDm_ADDR_CR(mctx->addr) == le->cr.rem2loc.resp) {
- LOGP(DLLAPDM, LOGL_NOTICE, "I frame response not allowed\n");
msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_FRM_UNIMPL, mctx);
return -EINVAL;
}
+ msg->l2h[2] = LAPDm_LEN(l3_len); /* EL is set here too */
+ if (lctx->more)
+ msg->l2h[2] |= LAPDm_MORE;
- length = msg->l2h[2] >> 2;
- if (length == 0 || length + 3 > mctx->n201) {
- /* G.4.2 If the length indicator of an I frame is set
- * to a numerical value L>N201 or L=0, an MDL-ERROR-INDICATION
- * primitive with cause "I frame with incorrect length"
- * is sent to the mobile management entity. */
- LOGP(DLLAPDM, LOGL_NOTICE, "I frame length not allowed\n");
- msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_IFRM_INC_LEN, mctx);
- return -EIO;
- }
-
- /* G.4.2 If the numerical value of L is L<N201 and the M
- * bit is set to "1", then an MDL-ERROR-INDICATION primitive with
- * cause "I frame with incorrect use of M bit" is sent to the
- * mobile management entity. */
- if ((msg->l2h[2] & LAPDm_MORE) && length + 3 < mctx->n201) {
- LOGP(DLLAPDM, LOGL_NOTICE, "I frame with M bit too short\n");
- msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_IFRM_INC_MBITS, mctx);
- return -EIO;
- }
-
- switch (dl->state) {
- case LAPDm_STATE_IDLE:
- /* if P=1, respond DM with F=1 (5.2.2) */
- /* 5.4.5 all other frame types shall be discarded */
- if (LAPDm_CTRL_PF_BIT(mctx->ctrl))
- lapdm_send_dm(mctx); /* F=P */
- /* fall though */
- case LAPDm_STATE_SABM_SENT:
- case LAPDm_STATE_DISC_SENT:
- LOGP(DLLAPDM, LOGL_NOTICE, "I frame ignored in this state\n");
- msgb_free(msg);
- return 0;
- }
-
- /* 5.7.1: N(s) sequence error */
- if (ns != dl->V_recv) {
- LOGP(DLLAPDM, LOGL_NOTICE, "N(S) sequence error: N(S)=%u, "
- "V(R)=%u\n", ns, dl->V_recv);
- /* discard data */
- msgb_free(msg);
- if (!dl->seq_err_cond) {
- /* FIXME: help me understand what exactly todo here
- dl->seq_err_cond = 1;
- */
- lapdm_send_rej(mctx, LAPDm_CTRL_PF_BIT(mctx->ctrl));
- } else {
- }
- return -EIO;
- }
- dl->seq_err_cond = 0;
-
- /* Increment receiver state */
- dl->V_recv = inc_mod8(dl->V_recv);
- LOGP(DLLAPDM, LOGL_NOTICE, "incrementing V(R) to %u\n", dl->V_recv);
-
- /* 5.5.3.1: Acknowlege all transmitted frames up the the N(R)-1 */
- lapdm_acknowledge(mctx); /* V(A) is also set here */
-
- /* Only if we are not in own receiver busy condition */
- if (!dl->own_busy) {
- /* if the frame carries a complete segment */
- if (!(msg->l2h[2] & LAPDm_MORE)
- && !dl->rcv_buffer) {
- LOGP(DLLAPDM, LOGL_INFO, "message in single I frame\n");
- /* send a DATA INDICATION to L3 */
- msg->l3h = msg->l2h + 3;
- msgb_pull_l2h(msg);
- msg->len = length;
- msg->tail = msg->data + length;
- rc = send_rslms_rll_l3(RSL_MT_DATA_IND, mctx, msg);
- } else {
- /* create rcv_buffer */
- if (!dl->rcv_buffer) {
- LOGP(DLLAPDM, LOGL_INFO, "message in multiple I "
- "frames (first message)\n");
- dl->rcv_buffer = msgb_alloc_headroom(200+56, 56,
- "LAPDm RX");
- dl->rcv_buffer->l3h = dl->rcv_buffer->data;
- }
- /* concat. rcv_buffer */
- if (msgb_l3len(dl->rcv_buffer) + length > 200) {
- LOGP(DLLAPDM, LOGL_NOTICE, "Received frame "
- "overflow!\n");
- } else {
- memcpy(msgb_put(dl->rcv_buffer, length),
- msg->l2h + 3, length);
- }
- /* if the last segment was received */
- if (!(msg->l2h[2] & LAPDm_MORE)) {
- LOGP(DLLAPDM, LOGL_INFO, "message in multiple I "
- "frames (last message)\n");
- rc = send_rslms_rll_l3(RSL_MT_DATA_IND, mctx,
- dl->rcv_buffer);
- dl->rcv_buffer = NULL;
- } else
- LOGP(DLLAPDM, LOGL_INFO, "message in multiple I "
- "frames (next message)\n");
- msgb_free(msg);
-
- }
- } else
- LOGP(DLLAPDM, LOGL_INFO, "I frame ignored during own receiver "
- "busy condition\n");
-
- /* Check for P bit */
- if (LAPDm_CTRL_PF_BIT(mctx->ctrl)) {
- /* 5.5.2.1 */
- /* check if we are not in own receiver busy */
- if (!dl->own_busy) {
- LOGP(DLLAPDM, LOGL_INFO, "we are not busy, send RR\n");
- /* Send RR with F=1 */
- rc = lapdm_send_rr(mctx, 1);
- } else {
- LOGP(DLLAPDM, LOGL_INFO, "we are busy, send RNR\n");
- /* Send RNR with F=1 */
- rc = lapdm_send_rnr(mctx, 1);
- }
- } else {
- /* 5.5.2.2 */
- /* check if we are not in own receiver busy */
- if (!dl->own_busy) {
- /* NOTE: V(R) is already set above */
- rc = rslms_send_i(mctx, __LINE__);
- if (rc) {
- LOGP(DLLAPDM, LOGL_INFO, "we are not busy and "
- "have no pending data, send RR\n");
- /* Send RR with F=0 */
- return lapdm_send_rr(mctx, 0);
- }
- /* all I or one RR is sent, we are done */
- return 0;
- } else {
- LOGP(DLLAPDM, LOGL_INFO, "we are busy, send RNR\n");
- /* Send RNR with F=0 */
- rc = lapdm_send_rnr(mctx, 0);
- }
- }
-
- /* Send message, if possible due to acknowledged data */
- rslms_send_i(mctx, __LINE__);
-
- return rc;
-}
-
-/* Receive a LAPDm message from L1 */
-static int lapdm_ph_data_ind(struct msgb *msg, struct lapdm_msg_ctx *mctx)
-{
- int rc;
-
- /* G.2.3 EA bit set to "0" is not allowed in GSM */
- if (!LAPDm_ADDR_EA(mctx->addr)) {
- LOGP(DLLAPDM, LOGL_NOTICE, "EA bit 0 is not allowed in GSM\n");
- msgb_free(msg);
- rsl_rll_error(RLL_CAUSE_FRM_UNIMPL, mctx);
- return -EINVAL;
- }
-
- if (LAPDm_CTRL_is_U(mctx->ctrl))
- rc = lapdm_rx_u(msg, mctx);
- else if (LAPDm_CTRL_is_S(mctx->ctrl))
- rc = lapdm_rx_s(msg, mctx);
- else if (LAPDm_CTRL_is_I(mctx->ctrl))
- rc = lapdm_rx_i(msg, mctx);
- else {
- LOGP(DLLAPDM, LOGL_NOTICE, "unknown LAPDm format\n");
- msgb_free(msg);
- rc = -EINVAL;
- }
- return rc;
+ return tx_ph_data_enqueue(mctx->dl, msg, mctx->chan_nr, mctx->link_id,
+ 23);
}
/* input into layer2 (from layer 1) */
-static int l2_ph_data_ind(struct msgb *msg, struct lapdm_entity *le, uint8_t chan_nr, uint8_t link_id)
+static int l2_ph_data_ind(struct msgb *msg, struct lapdm_entity *le,
+ uint8_t chan_nr, uint8_t link_id)
{
uint8_t cbits = chan_nr >> 3;
uint8_t sapi; /* we cannot take SAPI from link_id, as L1 has no clue */
struct lapdm_msg_ctx mctx;
+ struct lapd_msg_ctx lctx;
int rc = 0;
+ int n201;
/* when we reach here, we have a msgb with l2h pointing to the raw
* 23byte mac block. The l1h has already been purged. */
+ memset(&mctx, 0, sizeof(mctx));
mctx.chan_nr = chan_nr;
mctx.link_id = link_id;
- mctx.addr = mctx.ctrl = 0;
/* check for L1 chan_nr/link_id and determine LAPDm hdr format */
if (cbits == 0x10 || cbits == 0x12) {
/* Format Bbis is used on BCCH and CCCH(PCH, NCH and AGCH) */
mctx.lapdm_fmt = LAPDm_FMT_Bbis;
- mctx.n201 = N201_Bbis;
+ n201 = N201_Bbis;
sapi = 0;
} else {
if (mctx.link_id & 0x40) {
@@ -1630,12 +551,12 @@ static int l2_ph_data_ind(struct msgb *msg, struct lapdm_entity *le, uint8_t cha
/* If sent by BTS, lapdm_fmt must be B4 */
if (le->mode == LAPDM_MODE_MS) {
mctx.lapdm_fmt = LAPDm_FMT_B4;
- mctx.n201 = N201_B4;
- LOGP(DLLAPDM, LOGL_INFO, "fmt=B4\n");
+ n201 = N201_B4;
+ LOGP(DLLAPD, LOGL_INFO, "fmt=B4\n");
} else {
mctx.lapdm_fmt = LAPDm_FMT_B;
- mctx.n201 = N201_AB_SACCH;
- LOGP(DLLAPDM, LOGL_INFO, "fmt=B\n");
+ n201 = N201_AB_SACCH;
+ LOGP(DLLAPD, LOGL_INFO, "fmt=B\n");
}
/* SACCH frames have a two-byte L1 header that
* OsmocomBB L1 doesn't strip */
@@ -1646,8 +567,8 @@ static int l2_ph_data_ind(struct msgb *msg, struct lapdm_entity *le, uint8_t cha
sapi = (msg->l2h[0] >> 2) & 7;
} else {
mctx.lapdm_fmt = LAPDm_FMT_B;
- LOGP(DLLAPDM, LOGL_INFO, "fmt=B\n");
- mctx.n201 = 23; // FIXME: select correct size by chan.
+ LOGP(DLLAPD, LOGL_INFO, "fmt=B\n");
+ n201 = 20; // FIXME: select correct size by chan.
sapi = (msg->l2h[0] >> 2) & 7;
}
}
@@ -1655,7 +576,7 @@ static int l2_ph_data_ind(struct msgb *msg, struct lapdm_entity *le, uint8_t cha
mctx.dl = datalink_for_sapi(le, sapi);
/* G.2.1 No action on frames containing an unallocated SAPI. */
if (!mctx.dl) {
- LOGP(DLLAPDM, LOGL_NOTICE, "Received frame for unsupported "
+ LOGP(DLLAPD, LOGL_NOTICE, "Received frame for unsupported "
"SAPI %d!\n", sapi);
msgb_free(msg);
return -EIO;
@@ -1665,17 +586,77 @@ static int l2_ph_data_ind(struct msgb *msg, struct lapdm_entity *le, uint8_t cha
case LAPDm_FMT_A:
case LAPDm_FMT_B:
case LAPDm_FMT_B4:
- mctx.addr = msg->l2h[0];
- if (!(mctx.addr & 0x01)) {
- LOGP(DLLAPDM, LOGL_ERROR, "we don't support "
- "multibyte addresses (discarding)\n");
+ lctx.dl = &mctx.dl->dl;
+ /* obtain SAPI from address field */
+ mctx.link_id |= LAPDm_ADDR_SAPI(msg->l2h[0]);
+ /* G.2.3 EA bit set to "0" is not allowed in GSM */
+ if (!LAPDm_ADDR_EA(msg->l2h[0])) {
+ LOGP(DLLAPD, LOGL_NOTICE, "EA bit 0 is not allowed in "
+ "GSM\n");
msgb_free(msg);
+ rsl_rll_error(RLL_CAUSE_FRM_UNIMPL, &mctx);
return -EINVAL;
}
- mctx.ctrl = msg->l2h[1];
- /* obtain SAPI from address field */
- mctx.link_id |= LAPDm_ADDR_SAPI(mctx.addr);
- rc = lapdm_ph_data_ind(msg, &mctx);
+ /* adress field */
+ lctx.lpd = LAPDm_ADDR_LPD(msg->l2h[0]);
+ lctx.sapi = LAPDm_ADDR_SAPI(msg->l2h[0]);
+ lctx.cr = LAPDm_ADDR_CR(msg->l2h[0]);
+ /* command field */
+ if (LAPDm_CTRL_is_I(msg->l2h[1])) {
+ lctx.format = LAPD_FORM_I;
+ lctx.n_send = LAPDm_CTRL_I_Ns(msg->l2h[1]);
+ lctx.n_recv = LAPDm_CTRL_Nr(msg->l2h[1]);
+ } else if (LAPDm_CTRL_is_S(msg->l2h[1])) {
+ lctx.format = LAPD_FORM_S;
+ lctx.n_recv = LAPDm_CTRL_Nr(msg->l2h[1]);
+ lctx.s_u = LAPDm_CTRL_S_BITS(msg->l2h[1]);
+ } else if (LAPDm_CTRL_is_U(msg->l2h[1])) {
+ lctx.format = LAPD_FORM_U;
+ lctx.s_u = LAPDm_CTRL_U_BITS(msg->l2h[1]);
+ } else
+ lctx.format = LAPD_FORM_UKN;
+ lctx.p_f = LAPDm_CTRL_PF_BIT(msg->l2h[1]);
+ if (lctx.sapi != LAPDm_SAPI_NORMAL
+ && lctx.sapi != LAPDm_SAPI_SMS
+ && lctx.format == LAPD_FORM_U
+ && lctx.s_u == LAPDm_U_UI) {
+ /* 5.3.3 UI frames with invalid SAPI values shall be
+ * discarded
+ */
+ LOGP(DLLAPD, LOGL_INFO, "sapi=%u (discarding)\n",
+ lctx.sapi);
+ msgb_free(msg);
+ return 0;
+ }
+ if (mctx.lapdm_fmt == LAPDm_FMT_B4) {
+ lctx.n201 = n201;
+ lctx.length = n201;
+ lctx.more = 0;
+ msg->l3h = msg->l2h + 2;
+ msgb_pull_l2h(msg);
+ } else {
+ /* length field */
+ if (!(msg->l2h[2] & LAPDm_EL)) {
+ /* G.4.1 If the EL bit is set to "0", an
+ * MDL-ERROR-INDICATION primitive with cause
+ * "frame not implemented" is sent to the
+ * mobile management entity. */
+ LOGP(DLLAPD, LOGL_NOTICE, "we don't support "
+ "multi-octet length\n");
+ msgb_free(msg);
+ rsl_rll_error(RLL_CAUSE_FRM_UNIMPL, &mctx);
+ return -EINVAL;
+ }
+ lctx.n201 = n201;
+ lctx.length = msg->l2h[2] >> 2;
+ lctx.more = !!(msg->l2h[2] & LAPDm_MORE);
+ msg->l3h = msg->l2h + 3;
+ msgb_pull_l2h(msg);
+ }
+ /* store context for messages from lapd */
+ memcpy(&mctx.dl->mctx, &mctx, sizeof(mctx.dl->mctx));
+ /* send to LAPD */
+ rc = lapd_ph_data_ind(msg, &lctx);
break;
case LAPDm_FMT_Bter:
/* FIXME */
@@ -1683,7 +664,7 @@ static int l2_ph_data_ind(struct msgb *msg, struct lapdm_entity *le, uint8_t cha
break;
case LAPDm_FMT_Bbis:
/* directly pass up to layer3 */
- LOGP(DLLAPDM, LOGL_INFO, "fmt=Bbis UI\n");
+ LOGP(DLLAPD, LOGL_INFO, "fmt=Bbis UI\n");
msg->l3h = msg->l2h;
msgb_pull_l2h(msg);
rc = send_rslms_rll_l3(RSL_MT_UNIT_DATA_IND, &mctx, msg);
@@ -1731,7 +712,7 @@ int lapdm_phsap_up(struct osmo_prim_hdr *oph, struct lapdm_entity *le)
int rc = 0;
if (oph->sap != SAP_GSM_PH) {
- LOGP(DLLAPDM, LOGL_ERROR, "primitive for unknown SAP %u\n",
+ LOGP(DLLAPD, LOGL_ERROR, "primitive for unknown SAP %u\n",
oph->sap);
return -ENODEV;
}
@@ -1739,7 +720,7 @@ int lapdm_phsap_up(struct osmo_prim_hdr *oph, struct lapdm_entity *le)
switch (oph->primitive) {
case PRIM_PH_DATA:
if (oph->operation != PRIM_OP_INDICATION) {
- LOGP(DLLAPDM, LOGL_ERROR, "PH_DATA is not INDICATION %u\n",
+ LOGP(DLLAPD, LOGL_ERROR, "PH_DATA is not INDICATION %u\n",
oph->operation);
return -ENODEV;
}
@@ -1748,7 +729,7 @@ int lapdm_phsap_up(struct osmo_prim_hdr *oph, struct lapdm_entity *le)
break;
case PRIM_PH_RTS:
if (oph->operation != PRIM_OP_INDICATION) {
- LOGP(DLLAPDM, LOGL_ERROR, "PH_RTS is not INDICATION %u\n",
+ LOGP(DLLAPD, LOGL_ERROR, "PH_RTS is not INDICATION %u\n",
oph->operation);
return -ENODEV;
}
@@ -1775,33 +756,44 @@ int lapdm_phsap_up(struct osmo_prim_hdr *oph, struct lapdm_entity *le)
/* L3 -> L2 / RSLMS -> LAPDm */
+/* Set LAPDm context for established connection */
+static int set_lapdm_context(struct lapdm_datalink *dl, uint8_t chan_nr,
+ uint8_t link_id, int n201, uint8_t sapi)
+{
+ memset(&dl->mctx, 0, sizeof(dl->mctx));
+ dl->mctx.dl = dl;
+ dl->mctx.chan_nr = chan_nr;
+ dl->mctx.link_id = link_id;
+ dl->dl.lctx.dl = &dl->dl;
+ dl->dl.lctx.n201 = n201;
+ dl->dl.lctx.sapi = sapi;
+
+ return 0;
+}
+
/* L3 requests establishment of data link */
static int rslms_rx_rll_est_req(struct msgb *msg, struct lapdm_datalink *dl)
{
- struct lapdm_entity *le = dl->entity;
struct abis_rsl_rll_hdr *rllh = msgb_l2(msg);
uint8_t chan_nr = rllh->chan_nr;
uint8_t link_id = rllh->link_id;
uint8_t sapi = rllh->link_id & 7;
struct tlv_parsed tv;
uint8_t length;
- uint8_t n201 = 23; //FIXME
+ int n201 = 20; //FIXME
+ struct osmo_dlsap_prim dp;
- /* Set chan_nr and link_id for established connection */
- memset(&dl->mctx, 0, sizeof(dl->mctx));
- dl->mctx.dl = dl;
- dl->mctx.n201 = n201;
- dl->mctx.chan_nr = chan_nr;
- dl->mctx.link_id = link_id;
+ /* Set LAPDm context for established connection */
+ set_lapdm_context(dl, chan_nr, link_id, n201, sapi);
- rsl_tlv_parse(&tv, rllh->data, msgb_l2len(msg)-sizeof(*rllh));
+ rsl_tlv_parse(&tv, rllh->data, msgb_l2len(msg) - sizeof(*rllh));
if (TLVP_PRESENT(&tv, RSL_IE_L3_INFO)) {
- msg->l3h = TLVP_VAL(&tv, RSL_IE_L3_INFO);
+ msg->l3h = (uint8_t *) TLVP_VAL(&tv, RSL_IE_L3_INFO);
/* contention resolution establishment procedure */
if (sapi != 0) {
/* According to clause 6, the contention resolution
* procedure is only permitted with SAPI value 0 */
- LOGP(DLLAPDM, LOGL_ERROR, "SAPI != 0 but contention"
+ LOGP(DLLAPD, LOGL_ERROR, "SAPI != 0 but contention"
"resolution (discarding)\n");
msgb_free(msg);
return send_rll_simple(RSL_MT_REL_IND, &dl->mctx);
@@ -1809,67 +801,41 @@ static int rslms_rx_rll_est_req(struct msgb *msg, struct lapdm_datalink *dl)
/* transmit a SABM command with the P bit set to "1". The SABM
* command shall contain the layer 3 message unit */
length = TLVP_LEN(&tv, RSL_IE_L3_INFO);
- LOGP(DLLAPDM, LOGL_INFO, "perform establishment with content "
- "(SABM)\n");
} else {
/* normal establishment procedure */
+ msg->l3h = msg->l2h + sizeof(*rllh);
length = 0;
- LOGP(DLLAPDM, LOGL_INFO, "perform normal establishm. (SABM)\n");
}
/* check if the layer3 message length exceeds N201 */
if (length + 3 > 21) { /* FIXME: do we know the channel N201? */
- LOGP(DLLAPDM, LOGL_ERROR, "frame too large: %d > N201(%d) "
+ LOGP(DLLAPD, LOGL_ERROR, "frame too large: %d > N201(%d) "
"(discarding)\n", length + 3, 21);
msgb_free(msg);
return send_rll_simple(RSL_MT_REL_IND, &dl->mctx);
}
- /* Flush send-queue */
- /* Clear send-buffer */
- lapdm_dl_flush_send(dl);
-
- /* Discard partly received L3 message */
- if (dl->rcv_buffer) {
- msgb_free(dl->rcv_buffer);
- dl->rcv_buffer = NULL;
- }
-
- /* Remove RLL header from msgb */
+ /* Remove RLL header from msgb and set length to L3-info */
msgb_pull_l2h(msg);
+ msg->len = length;
+ msg->tail = msg->data + length;
- /* Push LAPDm header on msgb */
- msg->l2h = msgb_push(msg, 3);
- msg->l2h[0] = LAPDm_ADDR(LAPDm_LPD_NORMAL, sapi, le->cr.loc2rem.cmd);
- msg->l2h[1] = LAPDm_CTRL_U(LAPDm_U_SABM, 1);
- msg->l2h[2] = LAPDm_LEN(length);
- /* Transmit-buffer carries exactly one segment */
- memcpy(dl->tx_hist[0], msg->l2h, 3 + length);
- dl->tx_length[0] = 3 + length;
- /* set Vs to 0, because it is used as index when resending SABM */
- dl->V_send = 0;
-
- /* Set states */
- dl->own_busy = dl->peer_busy = 0;
- dl->retrans_ctr = 0;
- lapdm_dl_newstate(dl, LAPDm_STATE_SABM_SENT);
-
- /* Tramsmit and start T200 */
- osmo_timer_schedule(&dl->t200, T200);
- return tx_ph_data_enqueue(dl, msg, chan_nr, link_id, n201);
+ /* prepare prim */
+ osmo_prim_init(&dp.oph, 0, PRIM_DL_EST, PRIM_OP_REQUEST, msg);
+
+ /* send to L2 */
+ return lapd_recv_dlsap(&dp, &dl->dl.lctx);
}
/* L3 requests transfer of unnumbered information */
static int rslms_rx_rll_udata_req(struct msgb *msg, struct lapdm_datalink *dl)
{
- struct lapdm_entity *le = dl->entity;
struct abis_rsl_rll_hdr *rllh = msgb_l2(msg);
uint8_t chan_nr = rllh->chan_nr;
uint8_t link_id = rllh->link_id;
uint8_t sapi = link_id & 7;
struct tlv_parsed tv;
int length;
- uint8_t n201 = 23; //FIXME
uint8_t ta = 0, tx_power = 0;
/* check if the layer3 message length exceeds N201 */
@@ -1883,38 +849,40 @@ static int rslms_rx_rll_udata_req(struct msgb *msg, struct lapdm_datalink *dl)
tx_power = *TLVP_VAL(&tv, RSL_IE_MS_POWER);
}
if (!TLVP_PRESENT(&tv, RSL_IE_L3_INFO)) {
- LOGP(DLLAPDM, LOGL_ERROR, "unit data request without message "
+ LOGP(DLLAPD, LOGL_ERROR, "unit data request without message "
"error\n");
msgb_free(msg);
return -EINVAL;
}
- msg->l3h = TLVP_VAL(&tv, RSL_IE_L3_INFO);
+ msg->l3h = (uint8_t *) TLVP_VAL(&tv, RSL_IE_L3_INFO);
length = TLVP_LEN(&tv, RSL_IE_L3_INFO);
/* check if the layer3 message length exceeds N201 */
if (length + 5 > 23) { /* FIXME: do we know the channel N201? */
- LOGP(DLLAPDM, LOGL_ERROR, "frame too large: %d > N201(%d) "
+ LOGP(DLLAPD, LOGL_ERROR, "frame too large: %d > N201(%d) "
"(discarding)\n", length + 5, 23);
msgb_free(msg);
return -EIO;
}
- LOGP(DLLAPDM, LOGL_INFO, "sending unit data (tx_power=%d, ta=%d)\n",
+ LOGP(DLLAPD, LOGL_INFO, "sending unit data (tx_power=%d, ta=%d)\n",
tx_power, ta);
- /* Remove RLL header from msgb */
+ /* Remove RLL header from msgb and set length to L3-info */
msgb_pull_l2h(msg);
+ msg->len = length;
+ msg->tail = msg->data + length;
/* Push L1 + LAPDm header on msgb */
msg->l2h = msgb_push(msg, 2 + 3);
msg->l2h[0] = tx_power;
msg->l2h[1] = ta;
- msg->l2h[2] = LAPDm_ADDR(LAPDm_LPD_NORMAL, sapi, le->cr.loc2rem.cmd);
+ msg->l2h[2] = LAPDm_ADDR(LAPDm_LPD_NORMAL, sapi, dl->dl.cr.loc2rem.cmd);
msg->l2h[3] = LAPDm_CTRL_U(LAPDm_U_UI, 0);
msg->l2h[4] = LAPDm_LEN(length);
// FIXME: short L2 header support
/* Tramsmit */
- return tx_ph_data_enqueue(dl, msg, chan_nr, link_id, n201);
+ return tx_ph_data_enqueue(dl, msg, chan_nr, link_id, 23);
}
/* L3 requests transfer of acknowledged information */
@@ -1922,143 +890,29 @@ static int rslms_rx_rll_data_req(struct msgb *msg, struct lapdm_datalink *dl)
{
struct abis_rsl_rll_hdr *rllh = msgb_l2(msg);
struct tlv_parsed tv;
+ int length;
+ struct osmo_dlsap_prim dp;
rsl_tlv_parse(&tv, rllh->data, msgb_l2len(msg)-sizeof(*rllh));
if (!TLVP_PRESENT(&tv, RSL_IE_L3_INFO)) {
- LOGP(DLLAPDM, LOGL_ERROR, "data request without message "
+ LOGP(DLLAPD, LOGL_ERROR, "data request without message "
"error\n");
msgb_free(msg);
return -EINVAL;
}
- msg->l3h = TLVP_VAL(&tv, RSL_IE_L3_INFO);
-
- LOGP(DLLAPDM, LOGL_INFO, "writing message to send-queue\n");
+ msg->l3h = (uint8_t *) TLVP_VAL(&tv, RSL_IE_L3_INFO);
+ length = TLVP_LEN(&tv, RSL_IE_L3_INFO);
- /* Remove the RSL/RLL header */
+ /* Remove RLL header from msgb and set length to L3-info */
msgb_pull_l2h(msg);
+ msg->len = length;
+ msg->tail = msg->data + length;
- /* Write data into the send queue */
- msgb_enqueue(&dl->send_queue, msg);
-
- /* Send message, if possible */
- rslms_send_i(&dl->mctx, __LINE__);
- return 0;
-}
-
-/* Send next I frame from queued/buffered data */
-static int rslms_send_i(struct lapdm_msg_ctx *mctx, int line)
-{
- struct lapdm_datalink *dl = mctx->dl;
- struct lapdm_entity *le = dl->entity;
- uint8_t chan_nr = mctx->chan_nr;
- uint8_t link_id = mctx->link_id;
- uint8_t sapi = link_id & 7;
- int k = k_sapi[sapi];
- struct msgb *msg;
- int length, left;
- int rc = - 1; /* we sent nothing */
-
- LOGP(DLLAPDM, LOGL_INFO, "%s() called from line %d\n", __func__, line);
-
- next_frame:
-
- if (dl->peer_busy) {
- LOGP(DLLAPDM, LOGL_INFO, "peer busy, not sending\n");
- return rc;
- }
-
- if (dl->state == LAPDm_STATE_TIMER_RECOV) {
- LOGP(DLLAPDM, LOGL_INFO, "timer recovery, not sending\n");
- return rc;
- }
-
- /* If the send state variable V(S) is equal to V(A) plus k
- * (where k is the maximum number of outstanding I frames - see
- * subclause 5.8.4), the data link layer entity shall not transmit any
- * new I frames, but shall retransmit an I frame as a result
- * of the error recovery procedures as described in subclauses 5.5.4 and
- * 5.5.7. */
- if (dl->V_send == add_mod8(dl->V_ack, k)) {
- LOGP(DLLAPDM, LOGL_INFO, "k frames outstanding, not sending "
- "more (k=%u V(S)=%u V(A)=%u)\n", k, dl->V_send,
- dl->V_ack);
- return rc;
- }
-
- /* if we have no tx_hist yet, we create it */
- if (!dl->tx_length[dl->V_send]) {
- /* Get next message into send-buffer, if any */
- if (!dl->send_buffer) {
- next_message:
- dl->send_out = 0;
- dl->send_buffer = msgb_dequeue(&dl->send_queue);
- /* No more data to be sent */
- if (!dl->send_buffer)
- return rc;
- LOGP(DLLAPDM, LOGL_INFO, "get message from "
- "send-queue\n");
- }
-
- /* How much is left in the send-buffer? */
- left = msgb_l3len(dl->send_buffer) - dl->send_out;
- /* Segment, if data exceeds N201 */
- length = left;
- if (length > mctx->n201 - 3)
- length = mctx->n201 - 3;
- LOGP(DLLAPDM, LOGL_INFO, "msg-len %d sent %d left %d N201 %d "
- "length %d first byte %02x\n",
- msgb_l3len(dl->send_buffer), dl->send_out, left,
- mctx->n201, length, dl->send_buffer->l3h[0]);
- /* If message in send-buffer is completely sent */
- if (left == 0) {
- msgb_free(dl->send_buffer);
- dl->send_buffer = NULL;
- goto next_message;
- }
-
- LOGP(DLLAPDM, LOGL_INFO, "send I frame %sV(S)=%d\n",
- (left > length) ? "segment " : "", dl->V_send);
-
- /* Create I frame (segment) and transmit-buffer content */
- msg = msgb_alloc_headroom(23+10, 10, "LAPDm I");
- msg->l2h = msgb_put(msg, 3 + length);
- msg->l2h[0] = LAPDm_ADDR(LAPDm_LPD_NORMAL, sapi, le->cr.loc2rem.cmd);
- msg->l2h[1] = LAPDm_CTRL_I(dl->V_recv, dl->V_send, 0);
- msg->l2h[2] = LAPDm_LEN(length);
- if (left > length)
- msg->l2h[2] |= LAPDm_MORE;
- memcpy(msg->l2h + 3, dl->send_buffer->l3h + dl->send_out,
- length);
- memcpy(dl->tx_hist[dl->V_send], msg->l2h, 3 + length);
- dl->tx_length[dl->V_send] = 3 + length;
- /* Add length to track how much is already in the tx buffer */
- dl->send_out += length;
- } else {
- LOGP(DLLAPDM, LOGL_INFO, "resend I frame from tx buffer "
- "V(S)=%d\n", dl->V_send);
-
- /* Create I frame (segment) from tx_hist */
- length = dl->tx_length[dl->V_send];
- msg = msgb_alloc_headroom(23+10, 10, "LAPDm I");
- msg->l2h = msgb_put(msg, length);
- memcpy(msg->l2h, dl->tx_hist[dl->V_send], length);
- msg->l2h[1] = LAPDm_CTRL_I(dl->V_recv, dl->V_send, 0);
- }
-
- /* The value of the send state variable V(S) shall be incremented by 1
- * at the end of the transmission of the I frame */
- dl->V_send = inc_mod8(dl->V_send);
-
- /* If timer T200 is not running at the time right before transmitting a
- * frame, when the PH-READY-TO-SEND primitive is received from the
- * physical layer., it shall be set. */
- if (!osmo_timer_pending(&dl->t200))
- osmo_timer_schedule(&dl->t200, T200);
+ /* prepare prim */
+ osmo_prim_init(&dp.oph, 0, PRIM_DL_DATA, PRIM_OP_REQUEST, msg);
- tx_ph_data_enqueue(dl, msg, chan_nr, link_id, mctx->n201);
-
- rc = 0; /* we sent something */
- goto next_frame;
+ /* send to L2 */
+ return lapd_recv_dlsap(&dp, &dl->dl.lctx);
}
/* L3 requests suspension of data link */
@@ -2066,165 +920,79 @@ static int rslms_rx_rll_susp_req(struct msgb *msg, struct lapdm_datalink *dl)
{
struct abis_rsl_rll_hdr *rllh = msgb_l2(msg);
uint8_t sapi = rllh->link_id & 7;
+ struct osmo_dlsap_prim dp;
if (sapi != 0) {
- LOGP(DLLAPDM, LOGL_ERROR, "SAPI != 0 while suspending\n");
+ LOGP(DLLAPD, LOGL_ERROR, "SAPI != 0 while suspending\n");
msgb_free(msg);
return -EINVAL;
}
- LOGP(DLLAPDM, LOGL_INFO, "perform suspension\n");
-
- /* put back the send-buffer to the send-queue (first position) */
- if (dl->send_buffer) {
- LOGP(DLLAPDM, LOGL_INFO, "put frame in sendbuffer back to "
- "queue\n");
- llist_add(&dl->send_buffer->list, &dl->send_queue);
- dl->send_buffer = NULL;
- } else
- LOGP(DLLAPDM, LOGL_INFO, "no frame in sendbuffer\n");
-
- /* Clear transmit buffer, but keep send buffer */
- lapdm_dl_flush_tx(dl);
+ /* prepare prim */
+ osmo_prim_init(&dp.oph, 0, PRIM_DL_SUSP, PRIM_OP_REQUEST, msg);
- msgb_free(msg);
-
- return send_rll_simple(RSL_MT_SUSP_CONF, &dl->mctx);
+ /* send to L2 */
+ return lapd_recv_dlsap(&dp, &dl->dl.lctx);
}
/* L3 requests resume of data link */
static int rslms_rx_rll_res_req(struct msgb *msg, struct lapdm_datalink *dl)
{
- struct lapdm_entity *le = dl->entity;
struct abis_rsl_rll_hdr *rllh = msgb_l2(msg);
+ int msg_type = rllh->c.msg_type;
uint8_t chan_nr = rllh->chan_nr;
uint8_t link_id = rllh->link_id;
uint8_t sapi = rllh->link_id & 7;
struct tlv_parsed tv;
uint8_t length;
- uint8_t n201 = 23; //FIXME
+ uint8_t n201 = 20; //FIXME
+ struct osmo_dlsap_prim dp;
- /* Set chan_nr and link_id for established connection */
- memset(&dl->mctx, 0, sizeof(dl->mctx));
- dl->mctx.dl = dl;
- dl->mctx.n201 = n201;
- dl->mctx.chan_nr = chan_nr;
- dl->mctx.link_id = link_id;
+ /* Set LAPDm context for established connection */
+ set_lapdm_context(dl, chan_nr, link_id, n201, sapi);
rsl_tlv_parse(&tv, rllh->data, msgb_l2len(msg)-sizeof(*rllh));
if (!TLVP_PRESENT(&tv, RSL_IE_L3_INFO)) {
- LOGP(DLLAPDM, LOGL_ERROR, "resume without message error\n");
+ LOGP(DLLAPD, LOGL_ERROR, "resume without message error\n");
msgb_free(msg);
return send_rll_simple(RSL_MT_REL_IND, &dl->mctx);
}
+ msg->l3h = (uint8_t *) TLVP_VAL(&tv, RSL_IE_L3_INFO);
length = TLVP_LEN(&tv, RSL_IE_L3_INFO);
- LOGP(DLLAPDM, LOGL_INFO, "perform re-establishment (SABM) length=%d\n",
- length);
-
- /* Replace message in the send-buffer (reconnect) */
- if (dl->send_buffer)
- msgb_free(dl->send_buffer);
- dl->send_out = 0;
- if (length) {
- /* Remove the RSL/RLL header */
- msgb_pull_l2h(msg);
- /* Write data into the send buffer, to be sent first */
- dl->send_buffer = msg;
- }
+ /* Remove RLL header from msgb and set length to L3-info */
+ msgb_pull_l2h(msg);
+ msg->len = length;
+ msg->tail = msg->data + length;
- /* Discard partly received L3 message */
- if (dl->rcv_buffer) {
- msgb_free(dl->rcv_buffer);
- dl->rcv_buffer = NULL;
- }
+ /* prepare prim */
+ osmo_prim_init(&dp.oph, 0, (msg_type == RSL_MT_RES_REQ) ? PRIM_DL_RES
+ : PRIM_DL_RECON, PRIM_OP_REQUEST, msg);
- /* Create new msgb (old one is now free) */
- msg = msgb_alloc_headroom(23+10, 10, "LAPDm SABM");
- msg->l2h = msgb_put(msg, 3);
- msg->l2h[0] = LAPDm_ADDR(LAPDm_LPD_NORMAL, sapi, le->cr.loc2rem.cmd);
- msg->l2h[1] = LAPDm_CTRL_U(LAPDm_U_SABM, 1);
- msg->l2h[2] = LAPDm_LEN(0);
- /* Transmit-buffer carries exactly one segment */
- memcpy(dl->tx_hist[0], msg->l2h, 3);
- dl->tx_length[0] = 3;
- /* set Vs to 0, because it is used as index when resending SABM */
- dl->V_send = 0;
-
- /* Set states */
- dl->own_busy = dl->peer_busy = 0;
- dl->retrans_ctr = 0;
- lapdm_dl_newstate(dl, LAPDm_STATE_SABM_SENT);
-
- /* Tramsmit and start T200 */
- osmo_timer_schedule(&dl->t200, T200);
- return tx_ph_data_enqueue(dl, msg, chan_nr, link_id, n201);
+ /* send to L2 */
+ return lapd_recv_dlsap(&dp, &dl->dl.lctx);
}
/* L3 requests release of data link */
static int rslms_rx_rll_rel_req(struct msgb *msg, struct lapdm_datalink *dl)
{
- struct lapdm_entity *le = dl->entity;
struct abis_rsl_rll_hdr *rllh = msgb_l2(msg);
- uint8_t chan_nr = rllh->chan_nr;
- uint8_t link_id = rllh->link_id;
- uint8_t sapi = rllh->link_id & 7;
uint8_t mode = 0;
+ struct osmo_dlsap_prim dp;
/* get release mode */
if (rllh->data[0] == RSL_IE_RELEASE_MODE)
mode = rllh->data[1] & 1;
- /* local release */
- if (mode) {
- LOGP(DLLAPDM, LOGL_INFO, "perform local release\n");
- msgb_free(msg);
- /* reset Timer T200 */
- osmo_timer_del(&dl->t200);
- /* enter idle state */
- lapdm_dl_newstate(dl, LAPDm_STATE_IDLE);
- /* flush buffers */
- lapdm_dl_flush_tx(dl);
- lapdm_dl_flush_send(dl);
- /* send notification to L3 */
- return send_rll_simple(RSL_MT_REL_CONF, &dl->mctx);
- }
-
- /* in case we are already disconnecting */
- if (dl->state == LAPDm_STATE_DISC_SENT)
- return -EBUSY;
-
- LOGP(DLLAPDM, LOGL_INFO, "perform normal release (DISC)\n");
-
/* Pull rllh */
msgb_pull(msg, msg->tail - msg->l2h);
- /* Push LAPDm header on msgb */
- msg->l2h = msgb_push(msg, 3);
- msg->l2h[0] = LAPDm_ADDR(LAPDm_LPD_NORMAL, sapi, le->cr.loc2rem.cmd);
- msg->l2h[1] = LAPDm_CTRL_U(LAPDm_U_DISC, 1);
- msg->l2h[2] = LAPDm_LEN(0);
- /* Transmit-buffer carries exactly one segment */
- memcpy(dl->tx_hist[0], msg->l2h, 3);
- dl->tx_length[0] = 3;
-
- /* Set states */
- dl->own_busy = dl->peer_busy = 0;
- dl->retrans_ctr = 0;
- lapdm_dl_newstate(dl, LAPDm_STATE_DISC_SENT);
-
- /* Tramsmit and start T200 */
- osmo_timer_schedule(&dl->t200, T200);
- return tx_ph_data_enqueue(dl, msg, chan_nr, link_id, dl->mctx.n201);
-}
-
-/* L3 requests release in idle state */
-static int rslms_rx_rll_rel_req_idle(struct msgb *msg, struct lapdm_datalink *dl)
-{
- msgb_free(msg);
+ /* prepare prim */
+ osmo_prim_init(&dp.oph, 0, PRIM_DL_REL, PRIM_OP_REQUEST, msg);
+ dp.u.rel_req.mode = mode;
- /* send notification to L3 */
- return send_rll_simple(RSL_MT_REL_CONF, &dl->mctx);
+ /* send to L2 */
+ return lapd_recv_dlsap(&dp, &dl->dl.lctx);
}
/* L3 requests channel in idle state */
@@ -2238,11 +1006,11 @@ static int rslms_rx_chan_rqd(struct lapdm_channel *lc, struct msgb *msg)
PRIM_OP_REQUEST, NULL);
if (msgb_l2len(msg) < sizeof(*cch) + 4 + 2 + 2) {
- LOGP(DLLAPDM, LOGL_ERROR, "Message too short for CHAN RQD!\n");
+ LOGP(DLLAPD, LOGL_ERROR, "Message too short for CHAN RQD!\n");
return -EINVAL;
}
if (cch->data[0] != RSL_IE_REQ_REFERENCE) {
- LOGP(DLLAPDM, LOGL_ERROR, "Missing REQ REFERENCE IE\n");
+ LOGP(DLLAPD, LOGL_ERROR, "Missing REQ REFERENCE IE\n");
return -EINVAL;
}
pp.u.rach_req.ra = cch->data[1];
@@ -2250,14 +1018,14 @@ static int rslms_rx_chan_rqd(struct lapdm_channel *lc, struct msgb *msg)
pp.u.rach_req.is_combined_ccch = cch->data[2] >> 7;
if (cch->data[4] != RSL_IE_ACCESS_DELAY) {
- LOGP(DLLAPDM, LOGL_ERROR, "Missing ACCESS_DELAY IE\n");
+ LOGP(DLLAPD, LOGL_ERROR, "Missing ACCESS_DELAY IE\n");
return -EINVAL;
}
/* TA = 0 - delay */
pp.u.rach_req.ta = 0 - cch->data[5];
if (cch->data[6] != RSL_IE_MS_POWER) {
- LOGP(DLLAPDM, LOGL_ERROR, "Missing MS POWER IE\n");
+ LOGP(DLLAPD, LOGL_ERROR, "Missing MS POWER IE\n");
return -EINVAL;
}
pp.u.rach_req.tx_power = cch->data[7];
@@ -2291,65 +1059,6 @@ static int l2_ph_chan_conf(struct msgb *msg, struct lapdm_entity *le, uint32_t f
return rslms_sendmsg(msg, le);
}
-const char *lapdm_state_names[] = {
- "LAPDm_STATE_NULL",
- "LAPDm_STATE_IDLE",
- "LAPDm_STATE_SABM_SENT",
- "LAPDm_STATE_MF_EST",
- "LAPDm_STATE_TIMER_RECOV",
- "LAPDm_STATE_DISC_SENT",
-};
-
-/* statefull handling for RSLms RLL messages from L3 */
-static struct l2downstate {
- uint32_t states;
- int type;
- int (*rout) (struct msgb *msg, struct lapdm_datalink *dl);
-} l2downstatelist[] = {
- /* create and send UI command */
- {ALL_STATES,
- RSL_MT_UNIT_DATA_REQ, rslms_rx_rll_udata_req},
-
- /* create and send SABM command */
- {SBIT(LAPDm_STATE_IDLE),
- RSL_MT_EST_REQ, rslms_rx_rll_est_req},
-
- /* create and send I command */
- {SBIT(LAPDm_STATE_MF_EST) |
- SBIT(LAPDm_STATE_TIMER_RECOV),
- RSL_MT_DATA_REQ, rslms_rx_rll_data_req},
-
- /* suspend datalink */
- {SBIT(LAPDm_STATE_MF_EST) |
- SBIT(LAPDm_STATE_TIMER_RECOV),
- RSL_MT_SUSP_REQ, rslms_rx_rll_susp_req},
-
- /* create and send SABM command (resume) */
- {SBIT(LAPDm_STATE_MF_EST) |
- SBIT(LAPDm_STATE_TIMER_RECOV),
- RSL_MT_RES_REQ, rslms_rx_rll_res_req},
-
- /* create and send SABM command (reconnect) */
- {SBIT(LAPDm_STATE_IDLE) |
- SBIT(LAPDm_STATE_MF_EST) |
- SBIT(LAPDm_STATE_TIMER_RECOV),
- RSL_MT_RECON_REQ, rslms_rx_rll_res_req},
-
- /* create and send DISC command */
- {SBIT(LAPDm_STATE_SABM_SENT) |
- SBIT(LAPDm_STATE_MF_EST) |
- SBIT(LAPDm_STATE_TIMER_RECOV) |
- SBIT(LAPDm_STATE_DISC_SENT),
- RSL_MT_REL_REQ, rslms_rx_rll_rel_req},
-
- /* release in idle state */
- {SBIT(LAPDm_STATE_IDLE),
- RSL_MT_REL_REQ, rslms_rx_rll_rel_req_idle},
-};
-
-#define L2DOWNSLLEN \
- (sizeof(l2downstatelist) / sizeof(struct l2downstate))
-
/* incoming RSLms RLL message from L3 */
static int rslms_rx_rll(struct msgb *msg, struct lapdm_channel *lc)
{
@@ -2358,11 +1067,10 @@ static int rslms_rx_rll(struct msgb *msg, struct lapdm_channel *lc)
uint8_t sapi = rllh->link_id & 7;
struct lapdm_entity *le;
struct lapdm_datalink *dl;
- int i, supported = 0;
int rc = 0;
if (msgb_l2len(msg) < sizeof(*rllh)) {
- LOGP(DLLAPDM, LOGL_ERROR, "Message too short for RLL hdr!\n");
+ LOGP(DLLAPD, LOGL_ERROR, "Message too short for RLL hdr!\n");
return -EINVAL;
}
@@ -2376,34 +1084,41 @@ static int rslms_rx_rll(struct msgb *msg, struct lapdm_channel *lc)
*/
dl = datalink_for_sapi(le, sapi);
if (!dl) {
- LOGP(DLLAPDM, LOGL_ERROR, "No instance for SAPI %d!\n", sapi);
+ LOGP(DLLAPD, LOGL_ERROR, "No instance for SAPI %d!\n", sapi);
return -EINVAL;
}
- LOGP(DLLAPDM, LOGL_INFO, "(%p) RLL Message '%s' received in state %s\n",
- lc->name, rsl_msg_name(msg_type), lapdm_state_names[dl->state]);
+ LOGP(DLLAPD, LOGL_INFO, "(%p) RLL Message '%s' received.\n",
+ lc->name, rsl_msg_name(msg_type));
- /* find function for current state and message */
- for (i = 0; i < L2DOWNSLLEN; i++) {
- if (msg_type == l2downstatelist[i].type)
- supported = 1;
- if ((msg_type == l2downstatelist[i].type)
- && ((1 << dl->state) & l2downstatelist[i].states))
- break;
- }
- if (!supported) {
- LOGP(DLLAPDM, LOGL_NOTICE, "Message unsupported.\n");
- msgb_free(msg);
- return 0;
- }
- if (i == L2DOWNSLLEN) {
- LOGP(DLLAPDM, LOGL_NOTICE, "Message unhandled at this state.\n");
+ switch (msg_type) {
+ case RSL_MT_UNIT_DATA_REQ:
+ rc = rslms_rx_rll_udata_req(msg, dl);
+ break;
+ case RSL_MT_EST_REQ:
+ rc = rslms_rx_rll_est_req(msg, dl);
+ break;
+ case RSL_MT_DATA_REQ:
+ rc = rslms_rx_rll_data_req(msg, dl);
+ break;
+ case RSL_MT_SUSP_REQ:
+ rc = rslms_rx_rll_susp_req(msg, dl);
+ break;
+ case RSL_MT_RES_REQ:
+ rc = rslms_rx_rll_res_req(msg, dl);
+ break;
+ case RSL_MT_RECON_REQ:
+ rc = rslms_rx_rll_res_req(msg, dl);
+ break;
+ case RSL_MT_REL_REQ:
+ rc = rslms_rx_rll_rel_req(msg, dl);
+ break;
+ default:
+ LOGP(DLLAPD, LOGL_NOTICE, "Message unsupported.\n");
msgb_free(msg);
- return 0;
+ rc = -EINVAL;
}
- rc = l2downstatelist[i].rout(msg, dl);
-
return rc;
}
@@ -2415,7 +1130,7 @@ static int rslms_rx_com_chan(struct msgb *msg, struct lapdm_channel *lc)
int rc = 0;
if (msgb_l2len(msg) < sizeof(*cch)) {
- LOGP(DLLAPDM, LOGL_ERROR, "Message too short for COM CHAN hdr!\n");
+ LOGP(DLLAPD, LOGL_ERROR, "Message too short for COM CHAN hdr!\n");
return -EINVAL;
}
@@ -2425,7 +1140,7 @@ static int rslms_rx_com_chan(struct msgb *msg, struct lapdm_channel *lc)
rc = rslms_rx_chan_rqd(lc, msg);
break;
default:
- LOGP(DLLAPDM, LOGL_NOTICE, "Unknown COMMON CHANNEL msg %d!\n",
+ LOGP(DLLAPD, LOGL_NOTICE, "Unknown COMMON CHANNEL msg %d!\n",
msg_type);
msgb_free(msg);
return 0;
@@ -2441,7 +1156,7 @@ int lapdm_rslms_recvmsg(struct msgb *msg, struct lapdm_channel *lc)
int rc = 0;
if (msgb_l2len(msg) < sizeof(*rslh)) {
- LOGP(DLLAPDM, LOGL_ERROR, "Message too short RSL hdr!\n");
+ LOGP(DLLAPD, LOGL_ERROR, "Message too short RSL hdr!\n");
return -EINVAL;
}
@@ -2453,7 +1168,7 @@ int lapdm_rslms_recvmsg(struct msgb *msg, struct lapdm_channel *lc)
rc = rslms_rx_com_chan(msg, lc);
break;
default:
- LOGP(DLLAPDM, LOGL_ERROR, "unknown RSLms message "
+ LOGP(DLLAPD, LOGL_ERROR, "unknown RSLms message "
"discriminator 0x%02x", rslh->msg_discr);
msgb_free(msg);
return -EINVAL;
@@ -2465,23 +1180,24 @@ int lapdm_rslms_recvmsg(struct msgb *msg, struct lapdm_channel *lc)
/*! \brief Set the \ref lapdm_mode of a LAPDm entity */
int lapdm_entity_set_mode(struct lapdm_entity *le, enum lapdm_mode mode)
{
+ int i;
+ enum lapd_mode lm;
+
switch (mode) {
case LAPDM_MODE_MS:
- le->cr.loc2rem.cmd = CR_MS2BS_CMD;
- le->cr.loc2rem.resp = CR_MS2BS_RESP;
- le->cr.rem2loc.cmd = CR_BS2MS_CMD;
- le->cr.rem2loc.resp = CR_BS2MS_RESP;
+ lm = LAPD_MODE_USER;
break;
case LAPDM_MODE_BTS:
- le->cr.loc2rem.cmd = CR_BS2MS_CMD;
- le->cr.loc2rem.resp = CR_BS2MS_RESP;
- le->cr.rem2loc.cmd = CR_MS2BS_CMD;
- le->cr.rem2loc.resp = CR_MS2BS_RESP;
+ lm = LAPD_MODE_NETWORK;
break;
default:
return -EINVAL;
}
+ for (i = 0; i < ARRAY_SIZE(le->datalink); i++) {
+ lapd_set_mode(&le->datalink[i].dl, lm);
+ }
+
le->mode = mode;
return 0;
@@ -2525,16 +1241,7 @@ void lapdm_entity_reset(struct lapdm_entity *le)
for (i = 0; i < ARRAY_SIZE(le->datalink); i++) {
dl = &le->datalink[i];
- if (dl->state == LAPDm_STATE_IDLE)
- continue;
- LOGP(DLLAPDM, LOGL_INFO, "Resetting LAPDm instance\n");
- /* reset Timer T200 */
- osmo_timer_del(&dl->t200);
- /* enter idle state */
- dl->state = LAPDm_STATE_IDLE;
- /* flush buffer */
- lapdm_dl_flush_tx(dl);
- lapdm_dl_flush_send(dl);
+ lapd_dl_reset(&dl->dl);
}
}