diff options
Diffstat (limited to 'src/shared/libosmocore/src/gsm/lapdm.c')
| -rw-r--r-- | src/shared/libosmocore/src/gsm/lapdm.c | 1249 |
1 files changed, 0 insertions, 1249 deletions
diff --git a/src/shared/libosmocore/src/gsm/lapdm.c b/src/shared/libosmocore/src/gsm/lapdm.c deleted file mode 100644 index 1c08113e..00000000 --- a/src/shared/libosmocore/src/gsm/lapdm.c +++ /dev/null @@ -1,1249 +0,0 @@ -/* GSM LAPDm (TS 04.06) 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 lapdm - * @{ - */ - -/*! \file lapdm.c */ - -#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/gsm/tlv.h> -#include <osmocom/gsm/rsl.h> -#include <osmocom/gsm/prim.h> -#include <osmocom/gsm/gsm_utils.h> -#include <osmocom/gsm/lapdm.h> - -#include <osmocom/gsm/protocol/gsm_04_08.h> -#include <osmocom/gsm/protocol/gsm_08_58.h> - -/* TS 04.06 Figure 4 / Section 3.2 */ -#define LAPDm_LPD_NORMAL 0 -#define LAPDm_LPD_SMSCB 1 -#define LAPDm_SAPI_NORMAL 0 -#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) - -/* TS 04.06 Table 3 / Section 3.4.3 */ -#define LAPDm_CTRL_I(nr, ns, p) ((((nr) & 0x7) << 5) | (((p) & 0x1) << 4) | (((ns) & 0x7) << 1)) -#define LAPDm_CTRL_S(nr, s, p) ((((nr) & 0x7) << 5) | (((p) & 0x1) << 4) | (((s) & 0x3) << 2) | 0x1) -#define LAPDm_CTRL_U(u, p) ((((u) & 0x1c) << (5-2)) | (((p) & 0x1) << 4) | (((u) & 0x3) << 2) | 0x3) - -#define LAPDm_CTRL_is_I(ctrl) (((ctrl) & 0x1) == 0) -#define LAPDm_CTRL_is_S(ctrl) (((ctrl) & 0x3) == 1) -#define LAPDm_CTRL_is_U(ctrl) (((ctrl) & 0x3) == 3) - -#define LAPDm_CTRL_U_BITS(ctrl) ((((ctrl) & 0xC) >> 2) | ((ctrl) & 0xE0) >> 3) -#define LAPDm_CTRL_PF_BIT(ctrl) (((ctrl) >> 4) & 0x1) - -#define LAPDm_CTRL_S_BITS(ctrl) (((ctrl) & 0xC) >> 2) - -#define LAPDm_CTRL_I_Ns(ctrl) (((ctrl) & 0xE) >> 1) -#define LAPDm_CTRL_Nr(ctrl) (((ctrl) & 0xE0) >> 5) - -#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 -#define N201_AB_SDCCH 20 -#define N201_AB_FACCH 20 -#define N201_Bbis 23 -#define N201_Bter_SACCH 21 -#define N201_Bter_SDCCH 23 -#define N201_Bter_FACCH 23 -#define N201_B4 19 - -/* 5.8.2.1 N200 during establish and release */ -#define N200_EST_REL 5 -/* 5.8.2.1 N200 during timer recovery state */ -#define N200_TR_SACCH 5 -#define N200_TR_SDCCH 23 -#define N200_TR_FACCH_FR 34 -#define N200_TR_EFACCH_FR 48 -#define N200_TR_FACCH_HR 29 -/* FIXME: set N200 depending on chan_nr */ -#define N200 N200_TR_SDCCH - -enum lapdm_format { - LAPDm_FMT_A, - LAPDm_FMT_B, - LAPDm_FMT_Bbis, - LAPDm_FMT_Bter, - LAPDm_FMT_B4, -}; - -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, int t200) -{ - memset(dl, 0, sizeof(*dl)); - 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; - dl->dl.t200_sec = t200; dl->dl.t200_usec = 0; -} - -/*! \brief initialize a LAPDm entity and all datalinks inside - * \param[in] le LAPDm entity - * \param[in] mode \ref lapdm_mode (BTS/MS) - */ -void lapdm_entity_init(struct lapdm_entity *le, enum lapdm_mode mode, int t200) -{ - unsigned int i; - - for (i = 0; i < ARRAY_SIZE(le->datalink); i++) - lapdm_dl_init(&le->datalink[i], le, t200); - - lapdm_entity_set_mode(le, mode); -} - -/*! \brief initialize a LAPDm channel and all its channels - * \param[in] lc \ref lapdm_channel to be initialized - * \param[in] mode \ref lapdm_mode (BTS/MS) - * - * This really is a convenience wrapper around calling \ref - * lapdm_entity_init twice. - */ -void lapdm_channel_init(struct lapdm_channel *lc, enum lapdm_mode mode) -{ - lapdm_entity_init(&lc->lapdm_acch, mode, 2); - /* FIXME: this depends on chan type */ - lapdm_entity_init(&lc->lapdm_dcch, mode, 1); -} - -/*! \brief flush and release all resoures in LAPDm entity */ -void lapdm_entity_exit(struct lapdm_entity *le) -{ - unsigned int i; - struct lapdm_datalink *dl; - - for (i = 0; i < ARRAY_SIZE(le->datalink); i++) { - dl = &le->datalink[i]; - lapd_dl_exit(&dl->dl); - } -} - -/* \brief lfush and release all resources in LAPDm channel - * - * A convenience wrapper calling \ref lapdm_entity_exit on both - * entities inside the \ref lapdm_channel - */ -void lapdm_channel_exit(struct lapdm_channel *lc) -{ - lapdm_entity_exit(&lc->lapdm_acch); - lapdm_entity_exit(&lc->lapdm_dcch); -} - -static struct lapdm_datalink *datalink_for_sapi(struct lapdm_entity *le, uint8_t sapi) -{ - switch (sapi) { - case LAPDm_SAPI_NORMAL: - return &le->datalink[0]; - case LAPDm_SAPI_SMS: - return &le->datalink[1]; - default: - return NULL; - } -} - -/* remove the L2 header from a MSGB */ -static inline unsigned char *msgb_pull_l2h(struct msgb *msg) -{ - unsigned char *ret = msgb_pull(msg, msg->l3h - msg->l2h); - msg->l2h = NULL; - return ret; -} - -/* Append padding (if required) */ -static void lapdm_pad_msgb(struct msgb *msg, uint8_t n201) -{ - int pad_len = n201 - msgb_l2len(msg); - uint8_t *data; - - if (pad_len < 0) { - LOGP(DLLAPD, LOGL_ERROR, - "cannot pad message that is already too big!\n"); - return; - } - - data = msgb_put(msg, pad_len); - memset(data, 0x2B, pad_len); -} - -/* input function that L2 calls when sending messages up to L3 */ -static int rslms_sendmsg(struct msgb *msg, struct lapdm_entity *le) -{ - if (!le->l3_cb) { - msgb_free(msg); - return -EIO; - } - - /* call the layer2 message handler that is registered */ - return le->l3_cb(msg, le, le->l3_ctx); -} - -/* 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 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) = pad; - *msgb_push(msg, 1) = link_id; - *msgb_push(msg, 1) = chan_nr; - msgb_enqueue(&dl->dl.tx_queue, msg); - return -EBUSY; - } - - osmo_prim_init(&pp.oph, SAP_GSM_PH, PRIM_PH_DATA, - PRIM_OP_REQUEST, msg); - pp.u.data.chan_nr = chan_nr; - pp.u.data.link_id = link_id; - - /* send the frame now */ - le->tx_pending = 0; /* disabled flow control */ - lapdm_pad_msgb(msg, pad); - - return le->l1_prim_cb(&pp.oph, le->l1_ctx); -} - -static struct msgb *tx_dequeue_msgb(struct lapdm_entity *le) -{ - struct lapdm_datalink *dl; - int last = le->last_tx_dequeue; - int i = last, n = ARRAY_SIZE(le->datalink); - struct msgb *msg = NULL; - - /* round-robin dequeue */ - do { - /* next */ - i = (i + 1) % n; - dl = &le->datalink[i]; - if ((msg = msgb_dequeue(&dl->dl.tx_queue))) - break; - } while (i != last); - - if (msg) { - /* Set last dequeue position */ - le->last_tx_dequeue = i; - } - - return msg; -} - -/*! \brief dequeue a msg that's pending transmission via L1 and wrap it into - * a osmo_phsap_prim */ -int lapdm_phsap_dequeue_prim(struct lapdm_entity *le, struct osmo_phsap_prim *pp) -{ - struct msgb *msg; - uint8_t pad; - - msg = tx_dequeue_msgb(le); - if (!msg) - return -ENODEV; - - /* if we have a message, send PH-DATA.req */ - osmo_prim_init(&pp->oph, SAP_GSM_PH, PRIM_PH_DATA, - PRIM_OP_REQUEST, msg); - - /* Pull chan_nr and link_id */ - pp->u.data.chan_nr = *msg->data; - msgb_pull(msg, 1); - pp->u.data.link_id = *msg->data; - msgb_pull(msg, 1); - pad = *msg->data; - msgb_pull(msg, 1); - - /* Pad the frame, we can transmit now */ - lapdm_pad_msgb(msg, pad); - - return 0; -} - -/* get next frame from the tx queue. because the ms has multiple datalinks, - * each datalink's queue is read round-robin. - */ -static int l2_ph_data_conf(struct msgb *msg, struct lapdm_entity *le) -{ - struct osmo_phsap_prim pp; - - /* we may send again */ - le->tx_pending = 0; - - /* free confirm message */ - if (msg) - msgb_free(msg); - - if (lapdm_phsap_dequeue_prim(le, &pp) < 0) { - /* no message in all queues */ - - /* If user didn't request PH-EMPTY_FRAME.req, abort */ - if (!(le->flags & LAPDM_ENT_F_EMPTY_FRAME)) - return 0; - - /* otherwise, send PH-EMPTY_FRAME.req */ - osmo_prim_init(&pp.oph, SAP_GSM_PH, - PRIM_PH_EMPTY_FRAME, - PRIM_OP_REQUEST, NULL); - } else { - le->tx_pending = 1; - } - - return le->l1_prim_cb(&pp.oph, le->l1_ctx); -} - -/* Create RSLms various RSLms messages */ -static int send_rslms_rll_l3(uint8_t msg_type, struct lapdm_msg_ctx *mctx, - struct msgb *msg) -{ - /* Add the RSL + RLL header */ - rsl_rll_push_l3(msg, msg_type, mctx->chan_nr, mctx->link_id, 1); - - /* send off the RSLms message to L3 */ - return rslms_sendmsg(msg, mctx->dl->entity); -} - -/* Take a B4 format message from L1 and create RSLms UNIT DATA IND */ -static int send_rslms_rll_l3_ui(struct lapdm_msg_ctx *mctx, struct msgb *msg) -{ - uint8_t l3_len = msg->tail - (uint8_t *)msgb_l3(msg); - struct abis_rsl_rll_hdr *rllh; - - /* Add the RSL + RLL header */ - msgb_tv16_push(msg, RSL_IE_L3_INFO, l3_len); - msgb_push(msg, 2 + 2); - rsl_rll_push_hdr(msg, RSL_MT_UNIT_DATA_IND, mctx->chan_nr, - mctx->link_id, 1); - rllh = (struct abis_rsl_rll_hdr *)msgb_l2(msg); - - rllh->data[0] = RSL_IE_TIMING_ADVANCE; - rllh->data[1] = mctx->ta_ind; - - rllh->data[2] = RSL_IE_MS_POWER; - rllh->data[3] = mctx->tx_power_ind; - - return rslms_sendmsg(msg, mctx->dl->entity); -} - -static int send_rll_simple(uint8_t msg_type, struct lapdm_msg_ctx *mctx) -{ - struct msgb *msg; - - msg = rsl_rll_simple(msg_type, mctx->chan_nr, mctx->link_id, 1); - - /* send off the RSLms message to L3 */ - return rslms_sendmsg(msg, mctx->dl->entity); -} - -static int rsl_rll_error(uint8_t cause, struct lapdm_msg_ctx *mctx) -{ - struct msgb *msg; - - 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); - msgb_tlv_put(msg, RSL_IE_RLM_CAUSE, 1, &cause); - return rslms_sendmsg(msg, mctx->dl->entity); -} - -/* DLSAP L2 -> L3 (RSLms) */ -static int send_rslms_dlsap(struct osmo_dlsap_prim *dp, - struct lapd_msg_ctx *lctx) -{ - 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 (OSMO_PRIM_HDR(&dp->oph)) { - case OSMO_PRIM(PRIM_DL_EST, PRIM_OP_INDICATION): - rll_msg = RSL_MT_EST_IND; - break; - case OSMO_PRIM(PRIM_DL_EST, PRIM_OP_CONFIRM): - rll_msg = RSL_MT_EST_CONF; - break; - case OSMO_PRIM(PRIM_DL_DATA, PRIM_OP_INDICATION): - rll_msg = RSL_MT_DATA_IND; - break; - case OSMO_PRIM(PRIM_DL_UNIT_DATA, PRIM_OP_INDICATION): - return send_rslms_rll_l3_ui(mctx, dp->oph.msg); - case OSMO_PRIM(PRIM_DL_REL, PRIM_OP_INDICATION): - rll_msg = RSL_MT_REL_IND; - break; - case OSMO_PRIM(PRIM_DL_REL, PRIM_OP_CONFIRM): - rll_msg = RSL_MT_REL_CONF; - break; - case OSMO_PRIM(PRIM_DL_SUSP, PRIM_OP_CONFIRM): - rll_msg = RSL_MT_SUSP_CONF; - break; - case OSMO_PRIM(PRIM_MDL_ERROR, PRIM_OP_INDICATION): - rsl_rll_error(dp->u.error_ind.cause, mctx); - if (dp->oph.msg) - msgb_free(dp->oph.msg); - return 0; - } - - if (!rll_msg) { - LOGP(DLLAPD, LOGL_ERROR, "Unsupported op %d, prim %d. Please " - "fix!\n", dp->oph.primitive, dp->oph.operation); - return -EINVAL; - } - - if (!dp->oph.msg) - return send_rll_simple(rll_msg, mctx); - - 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 LAPD_FORM_S: - msg->l2h[1] = LAPDm_CTRL_S(lctx->n_recv, lctx->s_u, lctx->p_f); - break; - case LAPD_FORM_U: - msg->l2h[1] = LAPDm_CTRL_U(lctx->s_u, lctx->p_f); - break; - default: - msgb_free(msg); - return -EINVAL; - } - msg->l2h[2] = LAPDm_LEN(l3_len); /* EL is set here too */ - if (lctx->more) - msg->l2h[2] |= LAPDm_MORE; - - /* add ACCH header with last indicated tx-power and TA */ - if ((mctx->link_id & 0x40)) { - struct lapdm_entity *le = mdl->entity; - - msg->l2h = msgb_push(msg, 2); - msg->l2h[0] = le->tx_power; - msg->l2h[1] = le->ta; - } - - 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) -{ - 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; - - /* 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; - n201 = N201_Bbis; - sapi = 0; - } else { - if (mctx.link_id & 0x40) { - /* It was received from network on SACCH */ - - /* If UI on SACCH sent by BTS, lapdm_fmt must be B4 */ - if (le->mode == LAPDM_MODE_MS - && LAPDm_CTRL_is_U(msg->l2h[3]) - && LAPDm_CTRL_U_BITS(msg->l2h[3]) == 0) { - mctx.lapdm_fmt = LAPDm_FMT_B4; - n201 = N201_B4; - LOGP(DLLAPD, LOGL_INFO, "fmt=B4\n"); - } else { - mctx.lapdm_fmt = LAPDm_FMT_B; - 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 */ - mctx.tx_power_ind = msg->l2h[0] & 0x1f; - mctx.ta_ind = msg->l2h[1]; - msgb_pull(msg, 2); - msg->l2h += 2; - sapi = (msg->l2h[0] >> 2) & 7; - } else { - mctx.lapdm_fmt = LAPDm_FMT_B; - LOGP(DLLAPD, LOGL_INFO, "fmt=B\n"); - n201 = N201_AB_SDCCH; - sapi = (msg->l2h[0] >> 2) & 7; - } - } - - mctx.dl = datalink_for_sapi(le, sapi); - /* G.2.1 No action on frames containing an unallocated SAPI. */ - if (!mctx.dl) { - LOGP(DLLAPD, LOGL_NOTICE, "Received frame for unsupported " - "SAPI %d!\n", sapi); - msgb_free(msg); - return -EIO; - } - - switch (mctx.lapdm_fmt) { - case LAPDm_FMT_A: - case LAPDm_FMT_B: - case LAPDm_FMT_B4: - 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; - } - /* 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 */ - msgb_free(msg); - break; - case LAPDm_FMT_Bbis: - /* directly pass up to layer3 */ - 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); - break; - default: - msgb_free(msg); - } - - return rc; -} - -/* input into layer2 (from layer 1) */ -static int l2_ph_rach_ind(struct lapdm_entity *le, uint8_t ra, uint32_t fn, uint8_t acc_delay) -{ - struct abis_rsl_cchan_hdr *ch; - struct gsm48_req_ref req_ref; - struct gsm_time gt; - struct msgb *msg = msgb_alloc_headroom(512, 64, "RSL CHAN RQD"); - - msg->l2h = msgb_push(msg, sizeof(*ch)); - ch = (struct abis_rsl_cchan_hdr *)msg->l2h; - rsl_init_cchan_hdr(ch, RSL_MT_CHAN_RQD); - ch->chan_nr = RSL_CHAN_RACH; - - /* generate a RSL CHANNEL REQUIRED message */ - gsm_fn2gsmtime(>, fn); - req_ref.ra = ra; - req_ref.t1 = gt.t1; /* FIXME: modulo? */ - req_ref.t2 = gt.t2; - req_ref.t3_low = gt.t3 & 7; - req_ref.t3_high = gt.t3 >> 3; - - msgb_tv_fixed_put(msg, RSL_IE_REQ_REFERENCE, 3, (uint8_t *) &req_ref); - msgb_tv_put(msg, RSL_IE_ACCESS_DELAY, acc_delay); - - return rslms_sendmsg(msg, le); -} - -static int l2_ph_chan_conf(struct msgb *msg, struct lapdm_entity *le, uint32_t frame_nr); - -/*! \brief Receive a PH-SAP primitive from L1 */ -int lapdm_phsap_up(struct osmo_prim_hdr *oph, struct lapdm_entity *le) -{ - struct osmo_phsap_prim *pp = (struct osmo_phsap_prim *) oph; - int rc = 0; - - if (oph->sap != SAP_GSM_PH) { - LOGP(DLLAPD, LOGL_ERROR, "primitive for unknown SAP %u\n", - oph->sap); - return -ENODEV; - } - - switch (oph->primitive) { - case PRIM_PH_DATA: - if (oph->operation != PRIM_OP_INDICATION) { - LOGP(DLLAPD, LOGL_ERROR, "PH_DATA is not INDICATION %u\n", - oph->operation); - return -ENODEV; - } - rc = l2_ph_data_ind(oph->msg, le, pp->u.data.chan_nr, - pp->u.data.link_id); - break; - case PRIM_PH_RTS: - if (oph->operation != PRIM_OP_INDICATION) { - LOGP(DLLAPD, LOGL_ERROR, "PH_RTS is not INDICATION %u\n", - oph->operation); - return -ENODEV; - } - rc = l2_ph_data_conf(oph->msg, le); - break; - case PRIM_PH_RACH: - switch (oph->operation) { - case PRIM_OP_INDICATION: - rc = l2_ph_rach_ind(le, pp->u.rach_ind.ra, pp->u.rach_ind.fn, - pp->u.rach_ind.acc_delay); - break; - case PRIM_OP_CONFIRM: - rc = l2_ph_chan_conf(oph->msg, le, pp->u.rach_ind.fn); - break; - default: - return -EIO; - } - break; - } - - return rc; -} - - -/* 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 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 = (rllh->link_id & 0x40) ? N201_AB_SACCH : N201_AB_SDCCH; - struct osmo_dlsap_prim dp; - - /* 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)) { - 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(DLLAPD, LOGL_ERROR, "SAPI != 0 but contention" - "resolution (discarding)\n"); - msgb_free(msg); - return send_rll_simple(RSL_MT_REL_IND, &dl->mctx); - } - /* 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); - } else { - /* normal establishment procedure */ - msg->l3h = msg->l2h + sizeof(*rllh); - length = 0; - } - - /* check if the layer3 message length exceeds N201 */ - if (length > n201) { - LOGP(DLLAPD, LOGL_ERROR, "frame too large: %d > N201(%d) " - "(discarding)\n", length, n201); - msgb_free(msg); - return send_rll_simple(RSL_MT_REL_IND, &dl->mctx); - } - - /* Remove RLL header from msgb and set length to L3-info */ - msgb_pull_l2h(msg); - msg->len = length; - msg->tail = msg->l3h + length; - - /* 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; - int ui_bts = (le->mode == LAPDM_MODE_BTS); - 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; - - /* check if the layer3 message length exceeds N201 */ - - rsl_tlv_parse(&tv, rllh->data, msgb_l2len(msg)-sizeof(*rllh)); - - if (TLVP_PRESENT(&tv, RSL_IE_TIMING_ADVANCE)) { - le->ta = *TLVP_VAL(&tv, RSL_IE_TIMING_ADVANCE); - } - if (TLVP_PRESENT(&tv, RSL_IE_MS_POWER)) { - le->tx_power = *TLVP_VAL(&tv, RSL_IE_MS_POWER); - } - if (!TLVP_PRESENT(&tv, RSL_IE_L3_INFO)) { - LOGP(DLLAPD, LOGL_ERROR, "unit data request without message " - "error\n"); - msgb_free(msg); - return -EINVAL; - } - 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 + 4 + !ui_bts > 23) { - LOGP(DLLAPD, LOGL_ERROR, "frame too large: %d > N201(%d) " - "(discarding)\n", length, 18 + ui_bts); - msgb_free(msg); - return -EIO; - } - - LOGP(DLLAPD, LOGL_INFO, "sending unit data (tx_power=%d, ta=%d)\n", - le->tx_power, le->ta); - - /* Remove RLL header from msgb and set length to L3-info */ - msgb_pull_l2h(msg); - msg->len = length; - msg->tail = msg->l3h + length; - - /* Push L1 + LAPDm header on msgb */ - msg->l2h = msgb_push(msg, 4 + !ui_bts); - msg->l2h[0] = le->tx_power; - msg->l2h[1] = le->ta; - msg->l2h[2] = LAPDm_ADDR(LAPDm_LPD_NORMAL, sapi, dl->dl.cr.loc2rem.cmd); - msg->l2h[3] = LAPDm_CTRL_U(LAPDm_U_UI, 0); - if (!ui_bts) - msg->l2h[4] = LAPDm_LEN(length); - - /* Tramsmit */ - return tx_ph_data_enqueue(dl, msg, chan_nr, link_id, 23); -} - -/* L3 requests transfer of acknowledged information */ -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(DLLAPD, LOGL_ERROR, "data request without message " - "error\n"); - msgb_free(msg); - return -EINVAL; - } - msg->l3h = (uint8_t *) TLVP_VAL(&tv, RSL_IE_L3_INFO); - length = TLVP_LEN(&tv, RSL_IE_L3_INFO); - - /* Remove RLL header from msgb and set length to L3-info */ - msgb_pull_l2h(msg); - msg->len = length; - msg->tail = msg->l3h + length; - - /* prepare prim */ - osmo_prim_init(&dp.oph, 0, PRIM_DL_DATA, PRIM_OP_REQUEST, msg); - - /* send to L2 */ - return lapd_recv_dlsap(&dp, &dl->dl.lctx); -} - -/* L3 requests suspension of data link */ -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(DLLAPD, LOGL_ERROR, "SAPI != 0 while suspending\n"); - msgb_free(msg); - return -EINVAL; - } - - /* prepare prim */ - osmo_prim_init(&dp.oph, 0, PRIM_DL_SUSP, PRIM_OP_REQUEST, msg); - - /* 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 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 = (rllh->link_id & 0x40) ? N201_AB_SACCH : N201_AB_SDCCH; - struct osmo_dlsap_prim dp; - - /* 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(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); - - /* Remove RLL header from msgb and set length to L3-info */ - msgb_pull_l2h(msg); - msg->len = length; - msg->tail = msg->l3h + length; - - /* prepare prim */ - osmo_prim_init(&dp.oph, 0, (msg_type == RSL_MT_RES_REQ) ? PRIM_DL_RES - : PRIM_DL_RECON, PRIM_OP_REQUEST, msg); - - /* 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 abis_rsl_rll_hdr *rllh = msgb_l2(msg); - 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; - - /* Pull rllh */ - msgb_pull_l2h(msg); - - /* 04.06 3.8.3: No information field is permitted with the DISC - * command. */ - msg->len = 0; - msg->tail = msg->l3h = msg->data; - - /* prepare prim */ - osmo_prim_init(&dp.oph, 0, PRIM_DL_REL, PRIM_OP_REQUEST, msg); - dp.u.rel_req.mode = mode; - - /* send to L2 */ - return lapd_recv_dlsap(&dp, &dl->dl.lctx); -} - -/* L3 requests channel in idle state */ -static int rslms_rx_chan_rqd(struct lapdm_channel *lc, struct msgb *msg) -{ - struct abis_rsl_cchan_hdr *cch = msgb_l2(msg); - void *l1ctx = lc->lapdm_dcch.l1_ctx; - struct osmo_phsap_prim pp; - - osmo_prim_init(&pp.oph, SAP_GSM_PH, PRIM_PH_RACH, - PRIM_OP_REQUEST, NULL); - - if (msgb_l2len(msg) < sizeof(*cch) + 4 + 2 + 2) { - LOGP(DLLAPD, LOGL_ERROR, "Message too short for CHAN RQD!\n"); - return -EINVAL; - } - if (cch->data[0] != RSL_IE_REQ_REFERENCE) { - LOGP(DLLAPD, LOGL_ERROR, "Missing REQ REFERENCE IE\n"); - return -EINVAL; - } - pp.u.rach_req.ra = cch->data[1]; - pp.u.rach_req.offset = ((cch->data[2] & 0x7f) << 8) | cch->data[3]; - pp.u.rach_req.is_combined_ccch = cch->data[2] >> 7; - - if (cch->data[4] != RSL_IE_ACCESS_DELAY) { - 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(DLLAPD, LOGL_ERROR, "Missing MS POWER IE\n"); - return -EINVAL; - } - pp.u.rach_req.tx_power = cch->data[7]; - - msgb_free(msg); - - return lc->lapdm_dcch.l1_prim_cb(&pp.oph, l1ctx); -} - -/* L1 confirms channel request */ -static int l2_ph_chan_conf(struct msgb *msg, struct lapdm_entity *le, uint32_t frame_nr) -{ - struct abis_rsl_cchan_hdr *ch; - struct gsm_time tm; - struct gsm48_req_ref *ref; - - gsm_fn2gsmtime(&tm, frame_nr); - - msgb_pull_l2h(msg); - msg->l2h = msgb_push(msg, sizeof(*ch) + sizeof(*ref)); - ch = (struct abis_rsl_cchan_hdr *)msg->l2h; - rsl_init_cchan_hdr(ch, RSL_MT_CHAN_CONF); - ch->chan_nr = RSL_CHAN_RACH; - ch->data[0] = RSL_IE_REQ_REFERENCE; - ref = (struct gsm48_req_ref *) (ch->data + 1); - ref->t1 = tm.t1; - ref->t2 = tm.t2; - ref->t3_low = tm.t3 & 0x7; - ref->t3_high = tm.t3 >> 3; - - return rslms_sendmsg(msg, le); -} - -/* incoming RSLms RLL message from L3 */ -static int rslms_rx_rll(struct msgb *msg, struct lapdm_channel *lc) -{ - struct abis_rsl_rll_hdr *rllh = msgb_l2(msg); - int msg_type = rllh->c.msg_type; - uint8_t sapi = rllh->link_id & 7; - struct lapdm_entity *le; - struct lapdm_datalink *dl; - int rc = 0; - - if (msgb_l2len(msg) < sizeof(*rllh)) { - LOGP(DLLAPD, LOGL_ERROR, "Message too short for RLL hdr!\n"); - msgb_free(msg); - return -EINVAL; - } - - if (rllh->link_id & 0x40) - le = &lc->lapdm_acch; - else - le = &lc->lapdm_dcch; - - /* G.2.1 No action schall be taken on frames containing an unallocated - * SAPI. - */ - dl = datalink_for_sapi(le, sapi); - if (!dl) { - LOGP(DLLAPD, LOGL_ERROR, "No instance for SAPI %d!\n", sapi); - msgb_free(msg); - return -EINVAL; - } - - LOGP(DLLAPD, LOGL_INFO, "(%p) RLL Message '%s' received. (sapi %d)\n", - lc->name, rsl_msg_name(msg_type), sapi); - - 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); - rc = -EINVAL; - } - - return rc; -} - -/* incoming RSLms COMMON CHANNEL message from L3 */ -static int rslms_rx_com_chan(struct msgb *msg, struct lapdm_channel *lc) -{ - struct abis_rsl_cchan_hdr *cch = msgb_l2(msg); - int msg_type = cch->c.msg_type; - int rc = 0; - - if (msgb_l2len(msg) < sizeof(*cch)) { - LOGP(DLLAPD, LOGL_ERROR, "Message too short for COM CHAN hdr!\n"); - return -EINVAL; - } - - switch (msg_type) { - case RSL_MT_CHAN_RQD: - /* create and send RACH request */ - rc = rslms_rx_chan_rqd(lc, msg); - break; - default: - LOGP(DLLAPD, LOGL_NOTICE, "Unknown COMMON CHANNEL msg %d!\n", - msg_type); - msgb_free(msg); - return 0; - } - - return rc; -} - -/*! \brief Receive a RSLms \ref msgb from Layer 3 */ -int lapdm_rslms_recvmsg(struct msgb *msg, struct lapdm_channel *lc) -{ - struct abis_rsl_common_hdr *rslh = msgb_l2(msg); - int rc = 0; - - if (msgb_l2len(msg) < sizeof(*rslh)) { - LOGP(DLLAPD, LOGL_ERROR, "Message too short RSL hdr!\n"); - return -EINVAL; - } - - switch (rslh->msg_discr & 0xfe) { - case ABIS_RSL_MDISC_RLL: - rc = rslms_rx_rll(msg, lc); - break; - case ABIS_RSL_MDISC_COM_CHAN: - rc = rslms_rx_com_chan(msg, lc); - break; - default: - LOGP(DLLAPD, LOGL_ERROR, "unknown RSLms message " - "discriminator 0x%02x", rslh->msg_discr); - msgb_free(msg); - return -EINVAL; - } - - return rc; -} - -/*! \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: - lm = LAPD_MODE_USER; - break; - case LAPDM_MODE_BTS: - 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; -} - -/*! \brief Set the \ref lapdm_mode of a LAPDm channel*/ -int lapdm_channel_set_mode(struct lapdm_channel *lc, enum lapdm_mode mode) -{ - int rc; - - rc = lapdm_entity_set_mode(&lc->lapdm_dcch, mode); - if (rc < 0) - return rc; - - return lapdm_entity_set_mode(&lc->lapdm_acch, mode); -} - -/*! \brief Set the L1 callback and context of a LAPDm channel */ -void lapdm_channel_set_l1(struct lapdm_channel *lc, osmo_prim_cb cb, void *ctx) -{ - lc->lapdm_dcch.l1_prim_cb = cb; - lc->lapdm_acch.l1_prim_cb = cb; - lc->lapdm_dcch.l1_ctx = ctx; - lc->lapdm_acch.l1_ctx = ctx; -} - -/*! \brief Set the L3 callback and context of a LAPDm channel */ -void lapdm_channel_set_l3(struct lapdm_channel *lc, lapdm_cb_t cb, void *ctx) -{ - lc->lapdm_dcch.l3_cb = cb; - lc->lapdm_acch.l3_cb = cb; - lc->lapdm_dcch.l3_ctx = ctx; - lc->lapdm_acch.l3_ctx = ctx; -} - -/*! \brief Reset an entire LAPDm entity and all its datalinks */ -void lapdm_entity_reset(struct lapdm_entity *le) -{ - struct lapdm_datalink *dl; - int i; - - for (i = 0; i < ARRAY_SIZE(le->datalink); i++) { - dl = &le->datalink[i]; - lapd_dl_reset(&dl->dl); - } -} - -/*! \brief Reset a LAPDm channel with all its entities */ -void lapdm_channel_reset(struct lapdm_channel *lc) -{ - lapdm_entity_reset(&lc->lapdm_dcch); - lapdm_entity_reset(&lc->lapdm_acch); -} - -/*! \brief Set the flags of a LAPDm entity */ -void lapdm_entity_set_flags(struct lapdm_entity *le, unsigned int flags) -{ - le->flags = flags; -} - -/*! \brief Set the flags of all LAPDm entities in a LAPDm channel */ -void lapdm_channel_set_flags(struct lapdm_channel *lc, unsigned int flags) -{ - lapdm_entity_set_flags(&lc->lapdm_dcch, flags); - lapdm_entity_set_flags(&lc->lapdm_acch, flags); -} - -/*! @} */ |