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Diffstat (limited to 'openbsc/src/gprs/gprs_llc.c')
-rw-r--r--openbsc/src/gprs/gprs_llc.c1132
1 files changed, 0 insertions, 1132 deletions
diff --git a/openbsc/src/gprs/gprs_llc.c b/openbsc/src/gprs/gprs_llc.c
deleted file mode 100644
index 2be663f98..000000000
--- a/openbsc/src/gprs/gprs_llc.c
+++ /dev/null
@@ -1,1132 +0,0 @@
-/* GPRS LLC protocol implementation as per 3GPP TS 04.64 */
-
-/* (C) 2009-2010 by Harald Welte <laforge@gnumonks.org>
- *
- * All Rights Reserved
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as published by
- * the Free Software Foundation; either version 3 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 Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
- */
-
-#include <errno.h>
-#include <stdint.h>
-#include <stdbool.h>
-
-#include <openssl/rand.h>
-
-#include <osmocom/core/msgb.h>
-#include <osmocom/core/linuxlist.h>
-#include <osmocom/core/timer.h>
-#include <osmocom/core/talloc.h>
-#include <osmocom/core/rate_ctr.h>
-#include <osmocom/gprs/gprs_bssgp.h>
-
-#include <openbsc/gsm_data.h>
-#include <openbsc/debug.h>
-#include <openbsc/gprs_sgsn.h>
-#include <openbsc/gprs_gmm.h>
-#include <openbsc/gprs_llc.h>
-#include <openbsc/crc24.h>
-#include <openbsc/sgsn.h>
-#include <openbsc/gsm_subscriber.h>
-#include <openbsc/gprs_llc_xid.h>
-#include <openbsc/gprs_sndcp_comp.h>
-#include <openbsc/gprs_sndcp.h>
-
-static struct gprs_llc_llme *llme_alloc(uint32_t tlli);
-static int gprs_llc_tx_xid(struct gprs_llc_lle *lle, struct msgb *msg,
- int command);
-static int gprs_llc_tx_u(struct msgb *msg, uint8_t sapi,
- int command, enum gprs_llc_u_cmd u_cmd, int pf_bit);
-
-/* BEGIN XID RELATED */
-
-/* Generate XID message */
-static int gprs_llc_generate_xid(uint8_t *bytes, int bytes_len,
- struct gprs_llc_xid_field *l3_xid_field,
- struct gprs_llc_llme *llme)
-{
- /* Note: Called by gprs_ll_xid_req() */
-
- LLIST_HEAD(xid_fields);
-
- struct gprs_llc_xid_field xid_version;
- struct gprs_llc_xid_field xid_n201u;
- struct gprs_llc_xid_field xid_n201i;
-
- xid_version.type = GPRS_LLC_XID_T_VERSION;
- xid_version.data = (uint8_t *) "\x00";
- xid_version.data_len = 1;
-
- xid_n201u.type = GPRS_LLC_XID_T_N201_U;
- xid_n201u.data = (uint8_t *) "\x05\xf0";
- xid_n201u.data_len = 2;
-
- xid_n201i.type = GPRS_LLC_XID_T_N201_I;
- xid_n201i.data = (uint8_t *) "\x05\xf0";
- xid_n201i.data_len = 2;
-
- /* Add locally managed XID Fields */
- llist_add(&xid_version.list, &xid_fields);
- llist_add(&xid_n201u.list, &xid_fields);
- llist_add(&xid_n201i.list, &xid_fields);
-
- /* Append layer 3 XID field (if present) */
- if (l3_xid_field) {
- /* Enforce layer 3 XID type (just to be sure) */
- l3_xid_field->type = GPRS_LLC_XID_T_L3_PAR;
-
- /* Add Layer 3 XID field to the list */
- llist_add(&l3_xid_field->list, &xid_fields);
- }
-
- /* Store generated XID for later reference */
- talloc_free(llme->xid);
- llme->xid = gprs_llc_copy_xid(llme, &xid_fields);
-
- return gprs_llc_compile_xid(bytes, bytes_len, &xid_fields);
-}
-
-/* Generate XID message that will cause the GMM to reset */
-static int gprs_llc_generate_xid_for_gmm_reset(uint8_t *bytes,
- int bytes_len, uint32_t iov_ui,
- struct gprs_llc_llme *llme)
-{
- /* Called by gprs_llgmm_reset() and
- * gprs_llgmm_reset_oldmsg() */
-
- LLIST_HEAD(xid_fields);
-
- struct gprs_llc_xid_field xid_reset;
- struct gprs_llc_xid_field xid_iovui;
-
- /* First XID component must be RESET */
- xid_reset.type = GPRS_LLC_XID_T_RESET;
- xid_reset.data = NULL;
- xid_reset.data_len = 0;
-
- /* Add new IOV-UI */
- xid_iovui.type = GPRS_LLC_XID_T_IOV_UI;
- xid_iovui.data = (uint8_t *) & iov_ui;
- xid_iovui.data_len = 4;
-
- /* Add locally managed XID Fields */
- llist_add(&xid_iovui.list, &xid_fields);
- llist_add(&xid_reset.list, &xid_fields);
-
- /* Store generated XID for later reference */
- talloc_free(llme->xid);
- llme->xid = gprs_llc_copy_xid(llme, &xid_fields);
-
- return gprs_llc_compile_xid(bytes, bytes_len, &xid_fields);
-}
-
-/* Process an incoming XID confirmation */
-static int gprs_llc_process_xid_conf(uint8_t *bytes, int bytes_len,
- struct gprs_llc_lle *lle)
-{
- /* Note: This function handles the response of a network originated
- * XID-Request. There XID messages reflected by the MS are analyzed
- * and processed here. The caller is called by rx_llc_xid(). */
-
- struct llist_head *xid_fields;
- struct gprs_llc_xid_field *xid_field;
- struct gprs_llc_xid_field *xid_field_request;
- struct gprs_llc_xid_field *xid_field_request_l3 = NULL;
-
- /* Pick layer3 XID from the XID request we have sent last */
- if (lle->llme->xid) {
- llist_for_each_entry(xid_field_request, lle->llme->xid, list) {
- if (xid_field_request->type == GPRS_LLC_XID_T_L3_PAR)
- xid_field_request_l3 = xid_field_request;
- }
- }
-
- /* Parse and analyze XID-Response */
- xid_fields = gprs_llc_parse_xid(NULL, bytes, bytes_len);
-
- if (xid_fields) {
-
- gprs_llc_dump_xid_fields(xid_fields, LOGL_DEBUG);
- llist_for_each_entry(xid_field, xid_fields, list) {
-
- /* Forward SNDCP-XID fields to Layer 3 (SNDCP) */
- if (xid_field->type == GPRS_LLC_XID_T_L3_PAR &&
- xid_field_request_l3) {
- sndcp_sn_xid_conf(xid_field,
- xid_field_request_l3, lle);
- }
-
- /* Process LLC-XID fields: */
- else {
-
- /* FIXME: Do something more useful with the
- * echoed XID-Information. Currently we
- * just ignore the response completely and
- * by doing so we blindly accept any changes
- * the MS might have done to the our XID
- * inquiry. There is a remainig risk of
- * malfunction! */
- LOGP(DLLC, LOGL_NOTICE,
- "Ignoring XID-Field: XID: type %s, data_len=%d, data=%s\n",
- get_value_string(gprs_llc_xid_type_names,
- xid_field->type),
- xid_field->data_len,
- osmo_hexdump_nospc(xid_field->data,
- xid_field->data_len));
- }
- }
- talloc_free(xid_fields);
- }
-
- /* Flush pending XID fields */
- talloc_free(lle->llme->xid);
- lle->llme->xid = NULL;
-
- return 0;
-}
-
-/* Process an incoming XID indication and generate an appropiate response */
-static int gprs_llc_process_xid_ind(uint8_t *bytes_request,
- int bytes_request_len,
- uint8_t *bytes_response,
- int bytes_response_maxlen,
- struct gprs_llc_lle *lle)
-{
- /* Note: This function computes the response that is sent back to the
- * MS when a mobile originated XID is received. The function is
- * called by rx_llc_xid() */
-
- int rc = -EINVAL;
-
- struct llist_head *xid_fields;
- struct llist_head *xid_fields_response;
-
- struct gprs_llc_xid_field *xid_field;
- struct gprs_llc_xid_field *xid_field_response;
-
- /* Parse and analyze XID-Request */
- xid_fields =
- gprs_llc_parse_xid(lle->llme, bytes_request, bytes_request_len);
- if (xid_fields) {
- xid_fields_response = talloc_zero(lle->llme, struct llist_head);
- INIT_LLIST_HEAD(xid_fields_response);
- gprs_llc_dump_xid_fields(xid_fields, LOGL_DEBUG);
-
- /* Process LLC-XID fields: */
- llist_for_each_entry(xid_field, xid_fields, list) {
-
- if (xid_field->type != GPRS_LLC_XID_T_L3_PAR) {
- /* FIXME: Check the incoming XID parameters for
- * for validity. Currently we just blindly
- * accept all XID fields by just echoing them.
- * There is a remaining risk of malfunction
- * when a MS submits values which defer from
- * the default! */
- LOGP(DLLC, LOGL_NOTICE,
- "Echoing XID-Field: XID: type %s, data_len=%d, data=%s\n",
- get_value_string(gprs_llc_xid_type_names,
- xid_field->type),
- xid_field->data_len,
- osmo_hexdump_nospc(xid_field->data,
- xid_field->data_len));
- xid_field_response =
- gprs_llc_dup_xid_field
- (lle->llme, xid_field);
- llist_add(&xid_field_response->list,
- xid_fields_response);
- }
- }
-
- /* Forward SNDCP-XID fields to Layer 3 (SNDCP) */
- llist_for_each_entry(xid_field, xid_fields, list) {
- if (xid_field->type == GPRS_LLC_XID_T_L3_PAR) {
-
- xid_field_response =
- talloc_zero(lle->llme,
- struct gprs_llc_xid_field);
- rc = sndcp_sn_xid_ind(xid_field,
- xid_field_response, lle);
- if (rc == 0)
- llist_add(&xid_field_response->list,
- xid_fields_response);
- else
- talloc_free(xid_field_response);
- }
- }
-
- rc = gprs_llc_compile_xid(bytes_response,
- bytes_response_maxlen,
- xid_fields_response);
- talloc_free(xid_fields_response);
- talloc_free(xid_fields);
- }
-
- return rc;
-}
-
-/* Dispatch XID indications and responses comming from the MS */
-static void rx_llc_xid(struct gprs_llc_lle *lle,
- struct gprs_llc_hdr_parsed *gph)
-{
- uint8_t response[1024];
- int response_len;
-
- /* FIXME: 8.5.3.3: check if XID is invalid */
- if (gph->is_cmd) {
- LOGP(DLLC, LOGL_NOTICE,
- "Received XID indication from MS.\n");
-
- struct msgb *resp;
- uint8_t *xid;
- resp = msgb_alloc_headroom(4096, 1024, "LLC_XID");
-
- response_len =
- gprs_llc_process_xid_ind(gph->data, gph->data_len,
- response, sizeof(response),
- lle);
- if (response_len < 0) {
- LOGP(DLLC, LOGL_ERROR,
- "invalid XID indication received!\n");
- } else {
- xid = msgb_put(resp, response_len);
- memcpy(xid, response, response_len);
- }
- gprs_llc_tx_xid(lle, resp, 0);
- } else {
- LOGP(DLLC, LOGL_NOTICE,
- "Received XID confirmation from MS.\n");
- gprs_llc_process_xid_conf(gph->data, gph->data_len, lle);
- /* FIXME: if we had sent a XID reset, send
- * LLGMM-RESET.conf to GMM */
- }
-}
-
-/* Set of LL-XID negotiation (See also: TS 101 351, Section 7.2.2.4) */
-int gprs_ll_xid_req(struct gprs_llc_lle *lle,
- struct gprs_llc_xid_field *l3_xid_field)
-{
- /* Note: This functions is calle from gprs_sndcp.c */
-
- uint8_t xid_bytes[1024];;
- int xid_bytes_len;
- uint8_t *xid;
- struct msgb *msg;
- const char *ftype;
-
- /* Generate XID */
- xid_bytes_len =
- gprs_llc_generate_xid(xid_bytes, sizeof(xid_bytes),
- l3_xid_field, lle->llme);
-
- /* Only perform XID sending if the XID message contains something */
- if (xid_bytes_len > 0) {
- /* Transmit XID bytes */
- msg = msgb_alloc_headroom(4096, 1024, "LLC_XID");
- xid = msgb_put(msg, xid_bytes_len);
- memcpy(xid, xid_bytes, xid_bytes_len);
- if (l3_xid_field)
- ftype = get_value_string(gprs_llc_xid_type_names,
- l3_xid_field->type);
- else
- ftype = "NULL";
- LOGP(DLLC, LOGL_NOTICE, "Sending XID type %s (%d bytes) request"
- " to MS...\n", ftype, xid_bytes_len);
- gprs_llc_tx_xid(lle, msg, 1);
- } else {
- LOGP(DLLC, LOGL_ERROR,
- "XID-Message generation failed, XID not sent!\n");
- return -EINVAL;
- }
-
- return 0;
-}
-/* END XID RELATED */
-
-
-
-
-/* Entry function from upper level (LLC), asking us to transmit a BSSGP PDU
- * to a remote MS (identified by TLLI) at a BTS identified by its BVCI and NSEI */
-static int _bssgp_tx_dl_ud(struct msgb *msg, struct sgsn_mm_ctx *mmctx)
-{
- struct bssgp_dl_ud_par dup;
- const uint8_t qos_profile_default[3] = { 0x00, 0x00, 0x20 };
-
- memset(&dup, 0, sizeof(dup));
- /* before we have received some identity from the MS, we might
- * not yet have a MMC context (e.g. XID negotiation of primarly
- * LLC connection from GMM sapi). */
- if (mmctx) {
- dup.imsi = mmctx->imsi;
- dup.drx_parms = mmctx->drx_parms;
- dup.ms_ra_cap.len = mmctx->ms_radio_access_capa.len;
- dup.ms_ra_cap.v = mmctx->ms_radio_access_capa.buf;
-
- /* make sure we only send it to the right llme */
- OSMO_ASSERT(msgb_tlli(msg) == mmctx->gb.llme->tlli
- || msgb_tlli(msg) == mmctx->gb.llme->old_tlli);
- }
- memcpy(&dup.qos_profile, qos_profile_default,
- sizeof(qos_profile_default));
-
- return bssgp_tx_dl_ud(msg, 1000, &dup);
-}
-
-
-/* Section 8.9.9 LLC layer parameter default values */
-static const struct gprs_llc_params llc_default_params[NUM_SAPIS] = {
- [1] = {
- .t200_201 = 5,
- .n200 = 3,
- .n201_u = 400,
- },
- [2] = {
- .t200_201 = 5,
- .n200 = 3,
- .n201_u = 270,
- },
- [3] = {
- .iov_i_exp = 27,
- .t200_201 = 5,
- .n200 = 3,
- .n201_u = 500,
- .n201_i = 1503,
- .mD = 1520,
- .mU = 1520,
- .kD = 16,
- .kU = 16,
- },
- [5] = {
- .iov_i_exp = 27,
- .t200_201 = 10,
- .n200 = 3,
- .n201_u = 500,
- .n201_i = 1503,
- .mD = 760,
- .mU = 760,
- .kD = 8,
- .kU = 8,
- },
- [7] = {
- .t200_201 = 20,
- .n200 = 3,
- .n201_u = 270,
- },
- [8] = {
- .t200_201 = 20,
- .n200 = 3,
- .n201_u = 270,
- },
- [9] = {
- .iov_i_exp = 27,
- .t200_201 = 20,
- .n200 = 3,
- .n201_u = 500,
- .n201_i = 1503,
- .mD = 380,
- .mU = 380,
- .kD = 4,
- .kU = 4,
- },
- [11] = {
- .iov_i_exp = 27,
- .t200_201 = 40,
- .n200 = 3,
- .n201_u = 500,
- .n201_i = 1503,
- .mD = 190,
- .mU = 190,
- .kD = 2,
- .kU = 2,
- },
-};
-
-LLIST_HEAD(gprs_llc_llmes);
-void *llc_tall_ctx;
-
-/* lookup LLC Entity based on DLCI (TLLI+SAPI tuple) */
-static struct gprs_llc_lle *lle_by_tlli_sapi(const uint32_t tlli, uint8_t sapi)
-{
- struct gprs_llc_llme *llme;
-
- llist_for_each_entry(llme, &gprs_llc_llmes, list) {
- if (llme->tlli == tlli || llme->old_tlli == tlli)
- return &llme->lle[sapi];
- }
- return NULL;
-}
-
-struct gprs_llc_lle *gprs_lle_get_or_create(const uint32_t tlli, uint8_t sapi)
-{
- struct gprs_llc_llme *llme;
- struct gprs_llc_lle *lle;
-
- lle = lle_by_tlli_sapi(tlli, sapi);
- if (lle)
- return lle;
-
- LOGP(DLLC, LOGL_NOTICE, "LLC: unknown TLLI 0x%08x, "
- "creating LLME on the fly\n", tlli);
- llme = llme_alloc(tlli);
- lle = &llme->lle[sapi];
- return lle;
-}
-
-struct llist_head *gprs_llme_list(void)
-{
- return &gprs_llc_llmes;
-}
-
-/* lookup LLC Entity for RX based on DLCI (TLLI+SAPI tuple) */
-static struct gprs_llc_lle *lle_for_rx_by_tlli_sapi(const uint32_t tlli,
- uint8_t sapi, enum gprs_llc_cmd cmd)
-{
- struct gprs_llc_lle *lle;
-
- /* We already know about this TLLI */
- lle = lle_by_tlli_sapi(tlli, sapi);
- if (lle)
- return lle;
-
- /* Maybe it is a routing area update but we already know this sapi? */
- if (gprs_tlli_type(tlli) == TLLI_FOREIGN) {
- lle = lle_by_tlli_sapi(tlli, sapi);
- if (lle) {
- LOGP(DLLC, LOGL_NOTICE,
- "LLC RX: Found a local entry for TLLI 0x%08x\n",
- tlli);
- return lle;
- }
- }
-
- /* 7.2.1.1 LLC belonging to unassigned TLLI+SAPI shall be discarded,
- * except UID and XID frames with SAPI=1 */
- if (sapi == GPRS_SAPI_GMM &&
- (cmd == GPRS_LLC_XID || cmd == GPRS_LLC_UI)) {
- struct gprs_llc_llme *llme;
- /* FIXME: don't use the TLLI but the 0xFFFF unassigned? */
- llme = llme_alloc(tlli);
- LOGP(DLLC, LOGL_NOTICE, "LLC RX: unknown TLLI 0x%08x, "
- "creating LLME on the fly\n", tlli);
- lle = &llme->lle[sapi];
- return lle;
- }
-
- LOGP(DLLC, LOGL_NOTICE,
- "unknown TLLI(0x%08x)/SAPI(%d): Silently dropping\n",
- tlli, sapi);
- return NULL;
-}
-
-static void lle_init(struct gprs_llc_llme *llme, uint8_t sapi)
-{
- struct gprs_llc_lle *lle = &llme->lle[sapi];
-
- lle->llme = llme;
- lle->sapi = sapi;
- lle->state = GPRS_LLES_UNASSIGNED;
-
- /* Initialize according to parameters */
- memcpy(&lle->params, &llc_default_params[sapi], sizeof(lle->params));
-}
-
-static struct gprs_llc_llme *llme_alloc(uint32_t tlli)
-{
- struct gprs_llc_llme *llme;
- uint32_t i;
-
- llme = talloc_zero(llc_tall_ctx, struct gprs_llc_llme);
- if (!llme)
- return NULL;
-
- llme->tlli = tlli;
- llme->old_tlli = 0xffffffff;
- llme->state = GPRS_LLMS_UNASSIGNED;
- llme->age_timestamp = GPRS_LLME_RESET_AGE;
- llme->cksn = GSM_KEY_SEQ_INVAL;
-
- for (i = 0; i < ARRAY_SIZE(llme->lle); i++)
- lle_init(llme, i);
-
- llist_add(&llme->list, &gprs_llc_llmes);
-
- llme->comp.proto = gprs_sndcp_comp_alloc(llme);
- llme->comp.data = gprs_sndcp_comp_alloc(llme);
-
- return llme;
-}
-
-static void llme_free(struct gprs_llc_llme *llme)
-{
- gprs_sndcp_comp_free(llme->comp.proto);
- gprs_sndcp_comp_free(llme->comp.data);
- talloc_free(llme->xid);
- llist_del(&llme->list);
- talloc_free(llme);
-}
-
-#if 0
-/* FIXME: Unused code... */
-static void t200_expired(void *data)
-{
- struct gprs_llc_lle *lle = data;
-
- /* 8.5.1.3: Expiry of T200 */
-
- if (lle->retrans_ctr >= lle->params.n200) {
- /* FIXME: LLGM-STATUS-IND, LL-RELEASE-IND/CNF */
- lle->state = GPRS_LLES_ASSIGNED_ADM;
- }
-
- switch (lle->state) {
- case GPRS_LLES_LOCAL_EST:
- /* FIXME: retransmit SABM */
- /* FIXME: re-start T200 */
- lle->retrans_ctr++;
- break;
- case GPRS_LLES_LOCAL_REL:
- /* FIXME: retransmit DISC */
- /* FIXME: re-start T200 */
- lle->retrans_ctr++;
- break;
- default:
- LOGP(DLLC, LOGL_ERROR, "LLC unhandled state: %d\n", lle->state);
- break;
- }
-
-}
-
-static void t201_expired(void *data)
-{
- struct gprs_llc_lle *lle = data;
-
- if (lle->retrans_ctr < lle->params.n200) {
- /* FIXME: transmit apropriate supervisory frame (8.6.4.1) */
- /* FIXME: set timer T201 */
- lle->retrans_ctr++;
- }
-}
-#endif
-
-int gprs_llc_tx_u(struct msgb *msg, uint8_t sapi, int command,
- enum gprs_llc_u_cmd u_cmd, int pf_bit)
-{
- uint8_t *fcs, *llch;
- uint8_t addr, ctrl;
- uint32_t fcs_calc;
-
- /* Identifiers from UP: (TLLI, SAPI) + (BVCI, NSEI) */
-
- /* Address Field */
- addr = sapi & 0xf;
- if (command)
- addr |= 0x40;
-
- /* 6.3 Figure 8 */
- ctrl = 0xe0 | u_cmd;
- if (pf_bit)
- ctrl |= 0x10;
-
- /* prepend LLC UI header */
- llch = msgb_push(msg, 2);
- llch[0] = addr;
- llch[1] = ctrl;
-
- /* append FCS to end of frame */
- fcs = msgb_put(msg, 3);
- fcs_calc = gprs_llc_fcs(llch, fcs - llch);
- fcs[0] = fcs_calc & 0xff;
- fcs[1] = (fcs_calc >> 8) & 0xff;
- fcs[2] = (fcs_calc >> 16) & 0xff;
-
- /* Identifiers passed down: (BVCI, NSEI) */
-
- rate_ctr_inc(&sgsn->rate_ctrs->ctr[CTR_LLC_DL_PACKETS]);
- rate_ctr_add(&sgsn->rate_ctrs->ctr[CTR_LLC_DL_BYTES], msg->len);
-
- /* Send BSSGP-DL-UNITDATA.req */
- return _bssgp_tx_dl_ud(msg, NULL);
-}
-
-/* Send XID response to LLE */
-static int gprs_llc_tx_xid(struct gprs_llc_lle *lle, struct msgb *msg,
- int command)
-{
- /* copy identifiers from LLE to ensure lower layers can route */
- msgb_tlli(msg) = lle->llme->tlli;
- msgb_bvci(msg) = lle->llme->bvci;
- msgb_nsei(msg) = lle->llme->nsei;
-
- return gprs_llc_tx_u(msg, lle->sapi, command, GPRS_LLC_U_XID, 1);
-}
-
-/* encrypt information field + FCS, if needed! */
-static int apply_gea(struct gprs_llc_lle *lle, uint16_t crypt_len, uint16_t nu,
- uint32_t oc, uint8_t sapi, uint8_t *fcs, uint8_t *data)
-{
- uint8_t cipher_out[GSM0464_CIPH_MAX_BLOCK];
-
- if (lle->llme->algo == GPRS_ALGO_GEA0)
- return -EINVAL;
-
- /* Compute the 'Input' Paraemeter */
- uint32_t fcs_calc, iv = gprs_cipher_gen_input_ui(lle->llme->iov_ui, sapi,
- nu, oc);
- /* Compute gamma that we need to XOR with the data */
- int r = gprs_cipher_run(cipher_out, crypt_len, lle->llme->algo,
- lle->llme->kc, iv,
- fcs ? GPRS_CIPH_SGSN2MS : GPRS_CIPH_MS2SGSN);
- if (r < 0) {
- LOGP(DLLC, LOGL_ERROR, "Error producing %s gamma for UI "
- "frame: %d\n", get_value_string(gprs_cipher_names,
- lle->llme->algo), r);
- return -ENOMSG;
- }
-
- if (fcs) {
- /* Mark frame as encrypted and update FCS */
- data[2] |= 0x02;
- fcs_calc = gprs_llc_fcs(data, fcs - data);
- fcs[0] = fcs_calc & 0xff;
- fcs[1] = (fcs_calc >> 8) & 0xff;
- fcs[2] = (fcs_calc >> 16) & 0xff;
- data += 3;
- }
-
- /* XOR the cipher output with the data */
- for (r = 0; r < crypt_len; r++)
- *(data + r) ^= cipher_out[r];
-
- return 0;
-}
-
-/* Transmit a UI frame over the given SAPI:
- 'encryptable' indicates whether particular message can be encrypted according
- to 3GPP TS 24.008 ยง 4.7.1.2
- */
-int gprs_llc_tx_ui(struct msgb *msg, uint8_t sapi, int command,
- struct sgsn_mm_ctx *mmctx, bool encryptable)
-{
- struct gprs_llc_lle *lle;
- uint8_t *fcs, *llch;
- uint8_t addr, ctrl[2];
- uint32_t fcs_calc;
- uint16_t nu = 0;
- uint32_t oc;
-
- /* Identifiers from UP: (TLLI, SAPI) + (BVCI, NSEI) */
-
- /* look-up or create the LL Entity for this (TLLI, SAPI) tuple */
- lle = gprs_lle_get_or_create(msgb_tlli(msg), sapi);
-
- if (msg->len > lle->params.n201_u) {
- LOGP(DLLC, LOGL_ERROR, "Cannot Tx %u bytes (N201-U=%u)\n",
- msg->len, lle->params.n201_u);
- msgb_free(msg);
- return -EFBIG;
- }
-
- gprs_llme_copy_key(mmctx, lle->llme);
-
- /* Update LLE's (BVCI, NSEI) tuple */
- lle->llme->bvci = msgb_bvci(msg);
- lle->llme->nsei = msgb_nsei(msg);
-
- /* Obtain current values for N(u) and OC */
- nu = lle->vu_send;
- oc = lle->oc_ui_send;
- /* Increment V(U) */
- lle->vu_send = (lle->vu_send + 1) % 512;
- /* Increment Overflow Counter, if needed */
- if ((lle->vu_send + 1) / 512)
- lle->oc_ui_send += 512;
-
- /* Address Field */
- addr = sapi & 0xf;
- if (command)
- addr |= 0x40;
-
- /* Control Field */
- ctrl[0] = 0xc0;
- ctrl[0] |= nu >> 6;
- ctrl[1] = (nu << 2) & 0xfc;
- ctrl[1] |= 0x01; /* Protected Mode */
-
- /* prepend LLC UI header */
- llch = msgb_push(msg, 3);
- llch[0] = addr;
- llch[1] = ctrl[0];
- llch[2] = ctrl[1];
-
- /* append FCS to end of frame */
- fcs = msgb_put(msg, 3);
- fcs_calc = gprs_llc_fcs(llch, fcs - llch);
- fcs[0] = fcs_calc & 0xff;
- fcs[1] = (fcs_calc >> 8) & 0xff;
- fcs[2] = (fcs_calc >> 16) & 0xff;
-
- if (lle->llme->algo != GPRS_ALGO_GEA0 && encryptable) {
- int rc = apply_gea(lle, fcs - llch, nu, oc, sapi, fcs, llch);
- if (rc < 0) {
- msgb_free(msg);
- return rc;
- }
- }
-
- rate_ctr_inc(&sgsn->rate_ctrs->ctr[CTR_LLC_DL_PACKETS]);
- rate_ctr_add(&sgsn->rate_ctrs->ctr[CTR_LLC_DL_BYTES], msg->len);
-
- /* Identifiers passed down: (BVCI, NSEI) */
-
- /* Send BSSGP-DL-UNITDATA.req */
- return _bssgp_tx_dl_ud(msg, mmctx);
-}
-
-static int gprs_llc_hdr_rx(struct gprs_llc_hdr_parsed *gph,
- struct gprs_llc_lle *lle)
-{
- switch (gph->cmd) {
- case GPRS_LLC_SABM: /* Section 6.4.1.1 */
- lle->v_sent = lle->v_ack = lle->v_recv = 0;
- if (lle->state == GPRS_LLES_ASSIGNED_ADM) {
- /* start re-establishment (8.7.1) */
- }
- lle->state = GPRS_LLES_REMOTE_EST;
- /* FIXME: Send UA */
- lle->state = GPRS_LLES_ABM;
- /* FIXME: process data */
- break;
- case GPRS_LLC_DISC: /* Section 6.4.1.2 */
- /* FIXME: Send UA */
- /* terminate ABM */
- lle->state = GPRS_LLES_ASSIGNED_ADM;
- break;
- case GPRS_LLC_UA: /* Section 6.4.1.3 */
- if (lle->state == GPRS_LLES_LOCAL_EST)
- lle->state = GPRS_LLES_ABM;
- break;
- case GPRS_LLC_DM: /* Section 6.4.1.4: ABM cannot be performed */
- if (lle->state == GPRS_LLES_LOCAL_EST)
- lle->state = GPRS_LLES_ASSIGNED_ADM;
- break;
- case GPRS_LLC_FRMR: /* Section 6.4.1.5 */
- break;
- case GPRS_LLC_XID: /* Section 6.4.1.6 */
- rx_llc_xid(lle, gph);
- break;
- case GPRS_LLC_UI:
- if (gprs_llc_is_retransmit(gph->seq_tx, lle->vu_recv)) {
- LOGP(DLLC, LOGL_NOTICE,
- "TLLI=%08x dropping UI, N(U=%d) not in window V(URV(UR:%d).\n",
- lle->llme ? lle->llme->tlli : -1,
- gph->seq_tx, lle->vu_recv);
-
- /* HACK: non-standard recovery handling. If remote LLE
- * is re-transmitting the same sequence number for
- * three times, don't discard the frame but pass it on
- * and 'learn' the new sequence number */
- if (gph->seq_tx != lle->vu_recv_last) {
- lle->vu_recv_last = gph->seq_tx;
- lle->vu_recv_duplicates = 0;
- } else {
- lle->vu_recv_duplicates++;
- if (lle->vu_recv_duplicates < 3)
- return -EIO;
- LOGP(DLLC, LOGL_NOTICE, "TLLI=%08x recovering "
- "N(U=%d) after receiving %u duplicates\n",
- lle->llme ? lle->llme->tlli : -1,
- gph->seq_tx, lle->vu_recv_duplicates);
- }
- }
- /* Increment the sequence number that we expect in the next frame */
- lle->vu_recv = (gph->seq_tx + 1) % 512;
- /* Increment Overflow Counter */
- if ((gph->seq_tx + 1) / 512)
- lle->oc_ui_recv += 512;
- break;
- default:
- LOGP(DLLC, LOGL_NOTICE, "Unhandled command: %d\n", gph->cmd);
- break;
- }
-
- return 0;
-}
-
-/* receive an incoming LLC PDU (BSSGP-UL-UNITDATA-IND, 7.2.4.2) */
-int gprs_llc_rcvmsg(struct msgb *msg, struct tlv_parsed *tv)
-{
- struct gprs_llc_hdr *lh = (struct gprs_llc_hdr *) msgb_llch(msg);
- struct gprs_llc_hdr_parsed llhp;
- struct gprs_llc_lle *lle = NULL;
- bool drop_cipherable = false;
- int rc = 0;
-
- /* Identifiers from DOWN: NSEI, BVCI, TLLI */
-
- memset(&llhp, 0, sizeof(llhp));
- rc = gprs_llc_hdr_parse(&llhp, (uint8_t *) lh, TLVP_LEN(tv, BSSGP_IE_LLC_PDU));
- if (rc < 0) {
- LOGP(DLLC, LOGL_NOTICE, "Error during LLC header parsing\n");
- return rc;
- }
-
- switch (gprs_tlli_type(msgb_tlli(msg))) {
- case TLLI_LOCAL:
- case TLLI_FOREIGN:
- case TLLI_RANDOM:
- case TLLI_AUXILIARY:
- break;
- default:
- LOGP(DLLC, LOGL_ERROR,
- "Discarding frame with strange TLLI type\n");
- break;
- }
-
- /* find the LLC Entity for this TLLI+SAPI tuple */
- lle = lle_for_rx_by_tlli_sapi(msgb_tlli(msg), llhp.sapi, llhp.cmd);
- if (!lle) {
- switch (llhp.sapi) {
- case GPRS_SAPI_SNDCP3:
- case GPRS_SAPI_SNDCP5:
- case GPRS_SAPI_SNDCP9:
- case GPRS_SAPI_SNDCP11:
- /* Ask an upper layer for help. */
- return gsm0408_gprs_force_reattach_oldmsg(msg, NULL);
- default:
- break;
- }
- return 0;
- }
- gprs_llc_hdr_dump(&llhp, lle);
- /* reset age computation */
- lle->llme->age_timestamp = GPRS_LLME_RESET_AGE;
-
- /* decrypt information field + FCS, if needed! */
- if (llhp.is_encrypted) {
- if (lle->llme->algo != GPRS_ALGO_GEA0) {
- rc = apply_gea(lle, llhp.data_len + 3, llhp.seq_tx,
- lle->oc_ui_recv, lle->sapi, NULL,
- llhp.data);
- if (rc < 0)
- return rc;
- llhp.fcs = *(llhp.data + llhp.data_len);
- llhp.fcs |= *(llhp.data + llhp.data_len + 1) << 8;
- llhp.fcs |= *(llhp.data + llhp.data_len + 2) << 16;
- } else {
- LOGP(DLLC, LOGL_NOTICE, "encrypted frame for LLC that "
- "has no KC/Algo! Dropping.\n");
- return 0;
- }
- } else {
- if (lle->llme->algo != GPRS_ALGO_GEA0 &&
- lle->llme->cksn != GSM_KEY_SEQ_INVAL)
- drop_cipherable = true;
- }
-
- /* We have to do the FCS check _after_ decryption */
- llhp.fcs_calc = gprs_llc_fcs((uint8_t *)lh, llhp.crc_length);
- if (llhp.fcs != llhp.fcs_calc) {
- LOGP(DLLC, LOGL_INFO, "Dropping frame with invalid FCS\n");
- return -EIO;
- }
-
- /* Update LLE's (BVCI, NSEI) tuple */
- lle->llme->bvci = msgb_bvci(msg);
- lle->llme->nsei = msgb_nsei(msg);
-
- /* Receive and Process the actual LLC frame */
- rc = gprs_llc_hdr_rx(&llhp, lle);
- if (rc < 0)
- return rc;
-
- rate_ctr_inc(&sgsn->rate_ctrs->ctr[CTR_LLC_UL_PACKETS]);
- rate_ctr_add(&sgsn->rate_ctrs->ctr[CTR_LLC_UL_BYTES], msg->len);
-
- /* llhp.data is only set when we need to send LL_[UNIT]DATA_IND up */
- if (llhp.cmd == GPRS_LLC_UI && llhp.data && llhp.data_len) {
- msgb_gmmh(msg) = llhp.data;
- switch (llhp.sapi) {
- case GPRS_SAPI_GMM:
- /* send LL_UNITDATA_IND to GMM */
- rc = gsm0408_gprs_rcvmsg_gb(msg, lle->llme,
- drop_cipherable);
- break;
- case GPRS_SAPI_SNDCP3:
- case GPRS_SAPI_SNDCP5:
- case GPRS_SAPI_SNDCP9:
- case GPRS_SAPI_SNDCP11:
- /* send LL_DATA_IND/LL_UNITDATA_IND to SNDCP */
- rc = sndcp_llunitdata_ind(msg, lle, llhp.data, llhp.data_len);
- break;
- case GPRS_SAPI_SMS:
- /* FIXME */
- case GPRS_SAPI_TOM2:
- case GPRS_SAPI_TOM8:
- /* FIXME: send LL_DATA_IND/LL_UNITDATA_IND to TOM */
- default:
- LOGP(DLLC, LOGL_NOTICE, "Unsupported SAPI %u\n", llhp.sapi);
- rc = -EINVAL;
- break;
- }
- }
-
- return rc;
-}
-
-/* Propagate crypto parameters MM -> LLME */
-void gprs_llme_copy_key(struct sgsn_mm_ctx *mm, struct gprs_llc_llme *llme)
-{
- if (!mm)
- return;
- if (mm->ciph_algo != GPRS_ALGO_GEA0) {
- llme->algo = mm->ciph_algo;
- if (llme->cksn != mm->auth_triplet.key_seq &&
- mm->auth_triplet.key_seq != GSM_KEY_SEQ_INVAL) {
- memcpy(llme->kc, mm->auth_triplet.vec.kc,
- gprs_cipher_key_length(mm->ciph_algo));
- llme->cksn = mm->auth_triplet.key_seq;
- }
- } else
- llme->cksn = GSM_KEY_SEQ_INVAL;
-}
-
-/* 04.64 Chapter 7.2.1.1 LLGMM-ASSIGN */
-int gprs_llgmm_assign(struct gprs_llc_llme *llme,
- uint32_t old_tlli, uint32_t new_tlli)
-{
- unsigned int i;
-
- if (old_tlli == 0xffffffff && new_tlli != 0xffffffff) {
- /* TLLI Assignment 8.3.1 */
- /* New TLLI shall be assigned and used when (re)transmitting LLC frames */
- /* If old TLLI != 0xffffffff was assigned to LLME, then TLLI
- * old is unassigned. Only TLLI new shall be accepted when
- * received from peer. */
- if (llme->old_tlli != 0xffffffff) {
- llme->old_tlli = 0xffffffff;
- llme->tlli = new_tlli;
- } else {
- /* If TLLI old == 0xffffffff was assigned to LLME, then this is
- * TLLI assignmemt according to 8.3.1 */
- llme->old_tlli = 0xffffffff;
- llme->tlli = new_tlli;
- llme->state = GPRS_LLMS_ASSIGNED;
- /* 8.5.3.1 For all LLE's */
- for (i = 0; i < ARRAY_SIZE(llme->lle); i++) {
- struct gprs_llc_lle *l = &llme->lle[i];
- l->vu_send = l->vu_recv = 0;
- l->retrans_ctr = 0;
- l->state = GPRS_LLES_ASSIGNED_ADM;
- /* FIXME Set parameters according to table 9 */
- }
- }
- } else if (old_tlli != 0xffffffff && new_tlli != 0xffffffff) {
- /* TLLI Change 8.3.2 */
- /* Both TLLI Old and TLLI New are assigned; use New when
- * (re)transmitting. Accept both Old and New on Rx */
- llme->old_tlli = old_tlli;
- llme->tlli = new_tlli;
- llme->state = GPRS_LLMS_ASSIGNED;
- } else if (old_tlli != 0xffffffff && new_tlli == 0xffffffff) {
- /* TLLI Unassignment 8.3.3) */
- llme->tlli = llme->old_tlli = 0;
- llme->state = GPRS_LLMS_UNASSIGNED;
- for (i = 0; i < ARRAY_SIZE(llme->lle); i++) {
- struct gprs_llc_lle *l = &llme->lle[i];
- l->state = GPRS_LLES_UNASSIGNED;
- }
- llme_free(llme);
- } else
- return -EINVAL;
-
- return 0;
-}
-
-/* TLLI unassignment */
-int gprs_llgmm_unassign(struct gprs_llc_llme *llme)
-{
- return gprs_llgmm_assign(llme, llme->tlli, 0xffffffff);
-}
-
-/* Chapter 7.2.1.2 LLGMM-RESET.req */
-int gprs_llgmm_reset(struct gprs_llc_llme *llme)
-{
- struct msgb *msg = msgb_alloc_headroom(4096, 1024, "LLC_XID");
- struct gprs_llc_lle *lle = &llme->lle[1];
- uint8_t xid_bytes[1024];
- int xid_bytes_len;
- uint8_t *xid;
-
- LOGP(DLLC, LOGL_NOTICE, "LLGM Reset\n");
- if (RAND_bytes((uint8_t *) &llme->iov_ui, 4) != 1) {
- LOGP(DLLC, LOGL_NOTICE, "RAND_bytes failed for LLC XID reset, "
- "falling back to rand()\n");
- llme->iov_ui = rand();
- }
-
- /* Generate XID message */
- xid_bytes_len = gprs_llc_generate_xid_for_gmm_reset(xid_bytes,
- sizeof(xid_bytes),llme->iov_ui,llme);
- if (xid_bytes_len < 0)
- return -EINVAL;
- xid = msgb_put(msg, xid_bytes_len);
- memcpy(xid, xid_bytes, xid_bytes_len);
-
- /* Reset some of the LLC parameters. See GSM 04.64, 8.5.3.1 */
- lle->vu_recv = 0;
- lle->vu_send = 0;
- lle->oc_ui_send = 0;
- lle->oc_ui_recv = 0;
-
- /* FIXME: Start T200, wait for XID response */
- return gprs_llc_tx_xid(lle, msg, 1);
-}
-
-int gprs_llgmm_reset_oldmsg(struct msgb* oldmsg, uint8_t sapi,
- struct gprs_llc_llme *llme)
-{
- struct msgb *msg = msgb_alloc_headroom(4096, 1024, "LLC_XID");
- uint8_t xid_bytes[1024];
- int xid_bytes_len;
- uint8_t *xid;
-
- LOGP(DLLC, LOGL_NOTICE, "LLGM Reset\n");
- if (RAND_bytes((uint8_t *) &llme->iov_ui, 4) != 1) {
- LOGP(DLLC, LOGL_NOTICE, "RAND_bytes failed for LLC XID reset, "
- "falling back to rand()\n");
- llme->iov_ui = rand();
- }
-
- /* Generate XID message */
- xid_bytes_len = gprs_llc_generate_xid_for_gmm_reset(xid_bytes,
- sizeof(xid_bytes),llme->iov_ui,llme);
- if (xid_bytes_len < 0)
- return -EINVAL;
- xid = msgb_put(msg, xid_bytes_len);
- memcpy(xid, xid_bytes, xid_bytes_len);
-
- /* FIXME: Start T200, wait for XID response */
-
- msgb_tlli(msg) = msgb_tlli(oldmsg);
- msgb_bvci(msg) = msgb_bvci(oldmsg);
- msgb_nsei(msg) = msgb_nsei(oldmsg);
-
- return gprs_llc_tx_u(msg, sapi, 1, GPRS_LLC_U_XID, 1);
-}
-
-int gprs_llc_init(const char *cipher_plugin_path)
-{
- return gprs_cipher_load(cipher_plugin_path);
-}