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-rw-r--r--src/gprs/gprs_sndcp.c1258
1 files changed, 1258 insertions, 0 deletions
diff --git a/src/gprs/gprs_sndcp.c b/src/gprs/gprs_sndcp.c
new file mode 100644
index 000000000..a18998f9e
--- /dev/null
+++ b/src/gprs/gprs_sndcp.c
@@ -0,0 +1,1258 @@
+/* GPRS SNDCP protocol implementation as per 3GPP TS 04.65 */
+
+/* (C) 2010 by Harald Welte <laforge@gnumonks.org>
+ * (C) 2010 by On-Waves
+ *
+ * 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 <osmocom/core/msgb.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/timer.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/gprs/gprs_bssgp.h>
+
+#include <openbsc/gsm_data.h>
+#include <openbsc/debug.h>
+#include <openbsc/gprs_llc.h>
+#include <openbsc/sgsn.h>
+#include <openbsc/gprs_sndcp.h>
+#include <openbsc/gprs_llc_xid.h>
+#include <openbsc/gprs_sndcp_xid.h>
+#include <openbsc/gprs_sndcp_pcomp.h>
+#include <openbsc/gprs_sndcp_dcomp.h>
+#include <openbsc/gprs_sndcp_comp.h>
+
+#define DEBUG_IP_PACKETS 0 /* 0=Disabled, 1=Enabled */
+
+#if DEBUG_IP_PACKETS == 1
+/* Calculate TCP/IP checksum */
+static uint16_t calc_ip_csum(uint8_t *data, int len)
+{
+ int i;
+ uint32_t accumulator = 0;
+ uint16_t *pointer = (uint16_t *) data;
+
+ for (i = len; i > 1; i -= 2) {
+ accumulator += *pointer;
+ pointer++;
+ }
+
+ if (len % 2)
+ accumulator += *pointer;
+
+ accumulator = (accumulator & 0xffff) + ((accumulator >> 16) & 0xffff);
+ accumulator += (accumulator >> 16) & 0xffff;
+ return (~accumulator);
+}
+
+/* Calculate TCP/IP checksum */
+static uint16_t calc_tcpip_csum(const void *ctx, uint8_t *packet, int len)
+{
+ uint8_t *buf;
+ uint16_t csum;
+
+ buf = talloc_zero_size(ctx, len);
+ memset(buf, 0, len);
+ memcpy(buf, packet + 12, 8);
+ buf[9] = packet[9];
+ buf[11] = (len - 20) & 0xFF;
+ buf[10] = (len - 20) >> 8 & 0xFF;
+ memcpy(buf + 12, packet + 20, len - 20);
+ csum = calc_ip_csum(buf, len - 20 + 12);
+ talloc_free(buf);
+ return csum;
+}
+
+/* Show some ip packet details */
+static void debug_ip_packet(uint8_t *data, int len, int dir, char *info)
+{
+ uint8_t tcp_flags;
+ char flags_debugmsg[256];
+ int len_short;
+ static unsigned int packet_count = 0;
+ static unsigned int tcp_csum_err_count = 0;
+ static unsigned int ip_csum_err_count = 0;
+
+ packet_count++;
+
+ if (len > 80)
+ len_short = 80;
+ else
+ len_short = len;
+
+ if (dir)
+ DEBUGP(DSNDCP, "%s: MS => SGSN: %s\n", info,
+ osmo_hexdump_nospc(data, len_short));
+ else
+ DEBUGP(DSNDCP, "%s: MS <= SGSN: %s\n", info,
+ osmo_hexdump_nospc(data, len_short));
+
+ DEBUGP(DSNDCP, "%s: Length.: %d\n", info, len);
+ DEBUGP(DSNDCP, "%s: NO.: %d\n", info, packet_count);
+
+ if (len < 20) {
+ DEBUGP(DSNDCP, "%s: Error: Short IP packet!\n", info);
+ return;
+ }
+
+ if (calc_ip_csum(data, 20) != 0) {
+ DEBUGP(DSNDCP, "%s: Bad IP-Header checksum!\n", info);
+ ip_csum_err_count++;
+ } else
+ DEBUGP(DSNDCP, "%s: IP-Header checksum ok.\n", info);
+
+ if (data[9] == 0x06) {
+ if (len < 40) {
+ DEBUGP(DSNDCP, "%s: Error: Short TCP packet!\n", info);
+ return;
+ }
+
+ DEBUGP(DSNDCP, "%s: Protocol type: TCP\n", info);
+ tcp_flags = data[33];
+
+ if (calc_tcpip_csum(NULL, data, len) != 0) {
+ DEBUGP(DSNDCP, "%s: Bad TCP checksum!\n", info);
+ tcp_csum_err_count++;
+ } else
+ DEBUGP(DSNDCP, "%s: TCP checksum ok.\n", info);
+
+ memset(flags_debugmsg, 0, sizeof(flags_debugmsg));
+ if (tcp_flags & 1)
+ strcat(flags_debugmsg, "FIN ");
+ if (tcp_flags & 2)
+ strcat(flags_debugmsg, "SYN ");
+ if (tcp_flags & 4)
+ strcat(flags_debugmsg, "RST ");
+ if (tcp_flags & 8)
+ strcat(flags_debugmsg, "PSH ");
+ if (tcp_flags & 16)
+ strcat(flags_debugmsg, "ACK ");
+ if (tcp_flags & 32)
+ strcat(flags_debugmsg, "URG ");
+ DEBUGP(DSNDCP, "%s: FLAGS: %s\n", info, flags_debugmsg);
+ } else if (data[9] == 0x11) {
+ DEBUGP(DSNDCP, "%s: Protocol type: UDP\n", info);
+ } else {
+ DEBUGP(DSNDCP, "%s: Protocol type: (%02x)\n", info, data[9]);
+ }
+
+ DEBUGP(DSNDCP, "%s: IP-Header checksum errors: %d\n", info,
+ ip_csum_err_count);
+ DEBUGP(DSNDCP, "%s: TCP-Checksum errors: %d\n", info,
+ tcp_csum_err_count);
+}
+#endif
+
+/* Chapter 7.2: SN-PDU Formats */
+struct sndcp_common_hdr {
+ /* octet 1 */
+ uint8_t nsapi:4;
+ uint8_t more:1;
+ uint8_t type:1;
+ uint8_t first:1;
+ uint8_t spare:1;
+} __attribute__((packed));
+
+/* PCOMP / DCOMP only exist in first fragment */
+struct sndcp_comp_hdr {
+ /* octet 2 */
+ uint8_t pcomp:4;
+ uint8_t dcomp:4;
+} __attribute__((packed));
+
+struct sndcp_udata_hdr {
+ /* octet 3 */
+ uint8_t npdu_high:4;
+ uint8_t seg_nr:4;
+ /* octet 4 */
+ uint8_t npdu_low;
+} __attribute__((packed));
+
+
+static void *tall_sndcp_ctx;
+
+/* A fragment queue entry, containing one framgent of a N-PDU */
+struct defrag_queue_entry {
+ struct llist_head list;
+ /* segment number of this fragment */
+ uint32_t seg_nr;
+ /* length of the data area of this fragment */
+ uint32_t data_len;
+ /* pointer to the data of this fragment */
+ uint8_t *data;
+};
+
+LLIST_HEAD(gprs_sndcp_entities);
+
+/* Check if any compression parameters are set in the sgsn configuration */
+static inline int any_pcomp_or_dcomp_active(struct sgsn_instance *sgsn) {
+ if (sgsn->cfg.pcomp_rfc1144.active || sgsn->cfg.pcomp_rfc1144.passive ||
+ sgsn->cfg.dcomp_v42bis.active || sgsn->cfg.dcomp_v42bis.passive)
+ return true;
+ else
+ return false;
+}
+
+/* Enqueue a fragment into the defragment queue */
+static int defrag_enqueue(struct gprs_sndcp_entity *sne, uint8_t seg_nr,
+ uint8_t *data, uint32_t data_len)
+{
+ struct defrag_queue_entry *dqe;
+
+ dqe = talloc_zero(tall_sndcp_ctx, struct defrag_queue_entry);
+ if (!dqe)
+ return -ENOMEM;
+ dqe->data = talloc_zero_size(dqe, data_len);
+ if (!dqe->data) {
+ talloc_free(dqe);
+ return -ENOMEM;
+ }
+ dqe->seg_nr = seg_nr;
+ dqe->data_len = data_len;
+
+ llist_add(&dqe->list, &sne->defrag.frag_list);
+
+ if (seg_nr > sne->defrag.highest_seg)
+ sne->defrag.highest_seg = seg_nr;
+
+ sne->defrag.seg_have |= (1 << seg_nr);
+ sne->defrag.tot_len += data_len;
+
+ memcpy(dqe->data, data, data_len);
+
+ return 0;
+}
+
+/* return if we have all segments of this N-PDU */
+static int defrag_have_all_segments(struct gprs_sndcp_entity *sne)
+{
+ uint32_t seg_needed = 0;
+ unsigned int i;
+
+ /* create a bitmask of needed segments */
+ for (i = 0; i <= sne->defrag.highest_seg; i++)
+ seg_needed |= (1 << i);
+
+ if (seg_needed == sne->defrag.seg_have)
+ return 1;
+
+ return 0;
+}
+
+static struct defrag_queue_entry *defrag_get_seg(struct gprs_sndcp_entity *sne,
+ uint32_t seg_nr)
+{
+ struct defrag_queue_entry *dqe;
+
+ llist_for_each_entry(dqe, &sne->defrag.frag_list, list) {
+ if (dqe->seg_nr == seg_nr) {
+ llist_del(&dqe->list);
+ return dqe;
+ }
+ }
+ return NULL;
+}
+
+/* Perform actual defragmentation and create an output packet */
+static int defrag_segments(struct gprs_sndcp_entity *sne)
+{
+ struct msgb *msg;
+ unsigned int seg_nr;
+ uint8_t *npdu;
+ int npdu_len;
+ int rc;
+ uint8_t *expnd = NULL;
+
+ LOGP(DSNDCP, LOGL_DEBUG, "TLLI=0x%08x NSAPI=%u: Defragment output PDU %u "
+ "num_seg=%u tot_len=%u\n", sne->lle->llme->tlli, sne->nsapi,
+ sne->defrag.npdu, sne->defrag.highest_seg, sne->defrag.tot_len);
+ msg = msgb_alloc_headroom(sne->defrag.tot_len+256, 128, "SNDCP Defrag");
+ if (!msg)
+ return -ENOMEM;
+
+ /* FIXME: message headers + identifiers */
+
+ npdu = msg->data;
+
+ for (seg_nr = 0; seg_nr <= sne->defrag.highest_seg; seg_nr++) {
+ struct defrag_queue_entry *dqe;
+ uint8_t *data;
+
+ dqe = defrag_get_seg(sne, seg_nr);
+ if (!dqe) {
+ LOGP(DSNDCP, LOGL_ERROR, "Segment %u missing\n", seg_nr);
+ msgb_free(msg);
+ return -EIO;
+ }
+ /* actually append the segment to the N-PDU */
+ data = msgb_put(msg, dqe->data_len);
+ memcpy(data, dqe->data, dqe->data_len);
+
+ /* release memory for the fragment queue entry */
+ talloc_free(dqe);
+ }
+
+ npdu_len = sne->defrag.tot_len;
+
+ /* FIXME: cancel timer */
+
+ /* actually send the N-PDU to the SGSN core code, which then
+ * hands it off to the correct GTP tunnel + GGSN via gtp_data_req() */
+
+ /* Decompress packet */
+#if DEBUG_IP_PACKETS == 1
+ DEBUGP(DSNDCP, " \n");
+ DEBUGP(DSNDCP, ":::::::::::::::::::::::::::::::::::::::::::::::::::\n");
+ DEBUGP(DSNDCP, "===================================================\n");
+#endif
+ if (any_pcomp_or_dcomp_active(sgsn)) {
+
+ expnd = talloc_zero_size(msg, npdu_len * MAX_DATADECOMPR_FAC +
+ MAX_HDRDECOMPR_INCR);
+ memcpy(expnd, npdu, npdu_len);
+
+ /* Apply data decompression */
+ rc = gprs_sndcp_dcomp_expand(expnd, npdu_len, sne->defrag.dcomp,
+ sne->defrag.data);
+ if (rc < 0) {
+ LOGP(DSNDCP, LOGL_ERROR,
+ "Data decompression failed!\n");
+ talloc_free(expnd);
+ return -EIO;
+ }
+
+ /* Apply header decompression */
+ rc = gprs_sndcp_pcomp_expand(expnd, rc, sne->defrag.pcomp,
+ sne->defrag.proto);
+ if (rc < 0) {
+ LOGP(DSNDCP, LOGL_ERROR,
+ "TCP/IP Header decompression failed!\n");
+ talloc_free(expnd);
+ return -EIO;
+ }
+
+ /* Modify npu length, expnd is handed directly handed
+ * over to gsn_rx_sndcp_ud_ind(), see below */
+ npdu_len = rc;
+ } else
+ expnd = npdu;
+#if DEBUG_IP_PACKETS == 1
+ debug_ip_packet(expnd, npdu_len, 1, "defrag_segments()");
+ DEBUGP(DSNDCP, "===================================================\n");
+ DEBUGP(DSNDCP, ":::::::::::::::::::::::::::::::::::::::::::::::::::\n");
+ DEBUGP(DSNDCP, " \n");
+#endif
+
+ /* Hand off packet to gtp */
+ rc = sgsn_rx_sndcp_ud_ind(&sne->ra_id, sne->lle->llme->tlli,
+ sne->nsapi, msg, npdu_len, expnd);
+
+ if (any_pcomp_or_dcomp_active(sgsn))
+ talloc_free(expnd);
+
+ return rc;
+}
+
+static int defrag_input(struct gprs_sndcp_entity *sne, struct msgb *msg,
+ uint8_t *hdr, unsigned int len)
+{
+ struct sndcp_common_hdr *sch;
+ struct sndcp_udata_hdr *suh;
+ uint16_t npdu_num;
+ uint8_t *data;
+ int rc;
+
+ sch = (struct sndcp_common_hdr *) hdr;
+ if (sch->first) {
+ suh = (struct sndcp_udata_hdr *) (hdr + 1 + sizeof(struct sndcp_common_hdr));
+ } else
+ suh = (struct sndcp_udata_hdr *) (hdr + sizeof(struct sndcp_common_hdr));
+
+ data = (uint8_t *)suh + sizeof(struct sndcp_udata_hdr);
+
+ npdu_num = (suh->npdu_high << 8) | suh->npdu_low;
+
+ LOGP(DSNDCP, LOGL_DEBUG, "TLLI=0x%08x NSAPI=%u: Input PDU %u Segment %u "
+ "Length %u %s %s\n", sne->lle->llme->tlli, sne->nsapi, npdu_num,
+ suh->seg_nr, len, sch->first ? "F " : "", sch->more ? "M" : "");
+
+ if (sch->first) {
+ /* first segment of a new packet. Discard all leftover fragments of
+ * previous packet */
+ if (!llist_empty(&sne->defrag.frag_list)) {
+ struct defrag_queue_entry *dqe, *dqe2;
+ LOGP(DSNDCP, LOGL_INFO, "TLLI=0x%08x NSAPI=%u: Dropping "
+ "SN-PDU %u due to insufficient segments (%04x)\n",
+ sne->lle->llme->tlli, sne->nsapi, sne->defrag.npdu,
+ sne->defrag.seg_have);
+ llist_for_each_entry_safe(dqe, dqe2, &sne->defrag.frag_list, list) {
+ llist_del(&dqe->list);
+ talloc_free(dqe);
+ }
+ }
+ /* store the currently de-fragmented PDU number */
+ sne->defrag.npdu = npdu_num;
+
+ /* Re-set fragmentation state */
+ sne->defrag.no_more = sne->defrag.highest_seg = sne->defrag.seg_have = 0;
+ sne->defrag.tot_len = 0;
+ /* FIXME: (re)start timer */
+ }
+
+ if (sne->defrag.npdu != npdu_num) {
+ LOGP(DSNDCP, LOGL_INFO, "Segment for different SN-PDU "
+ "(%u != %u)\n", npdu_num, sne->defrag.npdu);
+ /* FIXME */
+ }
+
+ /* FIXME: check if seg_nr already exists */
+ /* make sure to subtract length of SNDCP header from 'len' */
+ rc = defrag_enqueue(sne, suh->seg_nr, data, len - (data - hdr));
+ if (rc < 0)
+ return rc;
+
+ if (!sch->more) {
+ /* this is suppsed to be the last segment of the N-PDU, but it
+ * might well be not the last to arrive */
+ sne->defrag.no_more = 1;
+ }
+
+ if (sne->defrag.no_more) {
+ /* we have already received the last segment before, let's check
+ * if all the previous segments exist */
+ if (defrag_have_all_segments(sne))
+ return defrag_segments(sne);
+ }
+
+ return 0;
+}
+
+static struct gprs_sndcp_entity *gprs_sndcp_entity_by_lle(const struct gprs_llc_lle *lle,
+ uint8_t nsapi)
+{
+ struct gprs_sndcp_entity *sne;
+
+ llist_for_each_entry(sne, &gprs_sndcp_entities, list) {
+ if (sne->lle == lle && sne->nsapi == nsapi)
+ return sne;
+ }
+ return NULL;
+}
+
+static struct gprs_sndcp_entity *gprs_sndcp_entity_alloc(struct gprs_llc_lle *lle,
+ uint8_t nsapi)
+{
+ struct gprs_sndcp_entity *sne;
+
+ sne = talloc_zero(tall_sndcp_ctx, struct gprs_sndcp_entity);
+ if (!sne)
+ return NULL;
+
+ sne->lle = lle;
+ sne->nsapi = nsapi;
+ sne->defrag.timer.data = sne;
+ //sne->fqueue.timer.cb = FIXME;
+ sne->rx_state = SNDCP_RX_S_FIRST;
+ INIT_LLIST_HEAD(&sne->defrag.frag_list);
+
+ llist_add(&sne->list, &gprs_sndcp_entities);
+
+ return sne;
+}
+
+/* Entry point for the SNSM-ACTIVATE.indication */
+int sndcp_sm_activate_ind(struct gprs_llc_lle *lle, uint8_t nsapi)
+{
+ LOGP(DSNDCP, LOGL_INFO, "SNSM-ACTIVATE.ind (lle=%p TLLI=%08x, "
+ "SAPI=%u, NSAPI=%u)\n", lle, lle->llme->tlli, lle->sapi, nsapi);
+
+ if (gprs_sndcp_entity_by_lle(lle, nsapi)) {
+ LOGP(DSNDCP, LOGL_ERROR, "Trying to ACTIVATE "
+ "already-existing entity (TLLI=%08x, NSAPI=%u)\n",
+ lle->llme->tlli, nsapi);
+ return -EEXIST;
+ }
+
+ if (!gprs_sndcp_entity_alloc(lle, nsapi)) {
+ LOGP(DSNDCP, LOGL_ERROR, "Out of memory during ACTIVATE\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+/* Entry point for the SNSM-DEACTIVATE.indication */
+int sndcp_sm_deactivate_ind(struct gprs_llc_lle *lle, uint8_t nsapi)
+{
+ struct gprs_sndcp_entity *sne;
+
+ LOGP(DSNDCP, LOGL_INFO, "SNSM-DEACTIVATE.ind (lle=%p, TLLI=%08x, "
+ "SAPI=%u, NSAPI=%u)\n", lle, lle->llme->tlli, lle->sapi, nsapi);
+
+ sne = gprs_sndcp_entity_by_lle(lle, nsapi);
+ if (!sne) {
+ LOGP(DSNDCP, LOGL_ERROR, "SNSM-DEACTIVATE.ind for non-"
+ "existing TLLI=%08x SAPI=%u NSAPI=%u\n", lle->llme->tlli,
+ lle->sapi, nsapi);
+ return -ENOENT;
+ }
+ llist_del(&sne->list);
+ /* frag queue entries are hierarchically allocated, so no need to
+ * free them explicitly here */
+ talloc_free(sne);
+
+ return 0;
+}
+
+/* Fragmenter state */
+struct sndcp_frag_state {
+ uint8_t frag_nr;
+ struct msgb *msg; /* original message */
+ uint8_t *next_byte; /* first byte of next fragment */
+
+ struct gprs_sndcp_entity *sne;
+ void *mmcontext;
+};
+
+/* returns '1' if there are more fragments to send, '0' if none */
+static int sndcp_send_ud_frag(struct sndcp_frag_state *fs,
+ uint8_t pcomp, uint8_t dcomp)
+{
+ struct gprs_sndcp_entity *sne = fs->sne;
+ struct gprs_llc_lle *lle = sne->lle;
+ struct sndcp_common_hdr *sch;
+ struct sndcp_comp_hdr *scomph;
+ struct sndcp_udata_hdr *suh;
+ struct msgb *fmsg;
+ unsigned int max_payload_len;
+ unsigned int len;
+ uint8_t *data;
+ int rc, more;
+
+ fmsg = msgb_alloc_headroom(fs->sne->lle->params.n201_u+256, 128,
+ "SNDCP Frag");
+ if (!fmsg) {
+ msgb_free(fs->msg);
+ return -ENOMEM;
+ }
+
+ /* make sure lower layers route the fragment like the original */
+ msgb_tlli(fmsg) = msgb_tlli(fs->msg);
+ msgb_bvci(fmsg) = msgb_bvci(fs->msg);
+ msgb_nsei(fmsg) = msgb_nsei(fs->msg);
+
+ /* prepend common SNDCP header */
+ sch = (struct sndcp_common_hdr *) msgb_put(fmsg, sizeof(*sch));
+ sch->nsapi = sne->nsapi;
+ /* Set FIRST bit if we are the first fragment in a series */
+ if (fs->frag_nr == 0)
+ sch->first = 1;
+ sch->type = 1;
+
+ /* append the compression header for first fragment */
+ if (sch->first) {
+ scomph = (struct sndcp_comp_hdr *)
+ msgb_put(fmsg, sizeof(*scomph));
+ scomph->pcomp = pcomp;
+ scomph->dcomp = dcomp;
+ }
+
+ /* append the user-data header */
+ suh = (struct sndcp_udata_hdr *) msgb_put(fmsg, sizeof(*suh));
+ suh->npdu_low = sne->tx_npdu_nr & 0xff;
+ suh->npdu_high = (sne->tx_npdu_nr >> 8) & 0xf;
+ suh->seg_nr = fs->frag_nr % 0xf;
+
+ /* calculate remaining length to be sent */
+ len = (fs->msg->data + fs->msg->len) - fs->next_byte;
+ /* how much payload can we actually send via LLC? */
+ max_payload_len = lle->params.n201_u - (sizeof(*sch) + sizeof(*suh));
+ if (sch->first)
+ max_payload_len -= sizeof(*scomph);
+ /* check if we're exceeding the max */
+ if (len > max_payload_len)
+ len = max_payload_len;
+
+ /* copy the actual fragment data into our fmsg */
+ data = msgb_put(fmsg, len);
+ memcpy(data, fs->next_byte, len);
+
+ /* Increment fragment number and data pointer to next fragment */
+ fs->frag_nr++;
+ fs->next_byte += len;
+
+ /* determine if we have more fragemnts to send */
+ if ((fs->msg->data + fs->msg->len) <= fs->next_byte)
+ more = 0;
+ else
+ more = 1;
+
+ /* set the MORE bit of the SNDCP header accordingly */
+ sch->more = more;
+
+ rc = gprs_llc_tx_ui(fmsg, lle->sapi, 0, fs->mmcontext, true);
+ /* abort in case of error, do not advance frag_nr / next_byte */
+ if (rc < 0) {
+ msgb_free(fs->msg);
+ return rc;
+ }
+
+ if (!more) {
+ /* we've sent all fragments */
+ msgb_free(fs->msg);
+ memset(fs, 0, sizeof(*fs));
+ /* increment NPDU number for next frame */
+ sne->tx_npdu_nr = (sne->tx_npdu_nr + 1) % 0xfff;
+ return 0;
+ }
+
+ /* default: more fragments to send */
+ return 1;
+}
+
+/* Request transmission of a SN-PDU over specified LLC Entity + SAPI */
+int sndcp_unitdata_req(struct msgb *msg, struct gprs_llc_lle *lle, uint8_t nsapi,
+ void *mmcontext)
+{
+ struct gprs_sndcp_entity *sne;
+ struct sndcp_common_hdr *sch;
+ struct sndcp_comp_hdr *scomph;
+ struct sndcp_udata_hdr *suh;
+ struct sndcp_frag_state fs;
+ uint8_t pcomp = 0;
+ uint8_t dcomp = 0;
+ int rc;
+
+ /* Identifiers from UP: (TLLI, SAPI) + (BVCI, NSEI) */
+
+ /* Compress packet */
+#if DEBUG_IP_PACKETS == 1
+ DEBUGP(DSNDCP, " \n");
+ DEBUGP(DSNDCP, ":::::::::::::::::::::::::::::::::::::::::::::::::::\n");
+ DEBUGP(DSNDCP, "===================================================\n");
+ debug_ip_packet(msg->data, msg->len, 0, "sndcp_initdata_req()");
+#endif
+ if (any_pcomp_or_dcomp_active(sgsn)) {
+
+ /* Apply header compression */
+ rc = gprs_sndcp_pcomp_compress(msg->data, msg->len, &pcomp,
+ lle->llme->comp.proto, nsapi);
+ if (rc < 0) {
+ LOGP(DSNDCP, LOGL_ERROR,
+ "TCP/IP Header compression failed!\n");
+ return -EIO;
+ }
+
+ /* Fixup pointer locations and sizes in message buffer to match
+ * the new, compressed buffer size */
+ msgb_get(msg, msg->len);
+ msgb_put(msg, rc);
+
+ /* Apply data compression */
+ rc = gprs_sndcp_dcomp_compress(msg->data, msg->len, &dcomp,
+ lle->llme->comp.data, nsapi);
+ if (rc < 0) {
+ LOGP(DSNDCP, LOGL_ERROR, "Data compression failed!\n");
+ return -EIO;
+ }
+
+ /* Fixup pointer locations and sizes in message buffer to match
+ * the new, compressed buffer size */
+ msgb_get(msg, msg->len);
+ msgb_put(msg, rc);
+ }
+#if DEBUG_IP_PACKETS == 1
+ DEBUGP(DSNDCP, "===================================================\n");
+ DEBUGP(DSNDCP, ":::::::::::::::::::::::::::::::::::::::::::::::::::\n");
+ DEBUGP(DSNDCP, " \n");
+#endif
+
+ sne = gprs_sndcp_entity_by_lle(lle, nsapi);
+ if (!sne) {
+ LOGP(DSNDCP, LOGL_ERROR, "Cannot find SNDCP Entity\n");
+ msgb_free(msg);
+ return -EIO;
+ }
+
+ /* Check if we need to fragment this N-PDU into multiple SN-PDUs */
+ if (msg->len > lle->params.n201_u -
+ (sizeof(*sch) + sizeof(*suh) + sizeof(*scomph))) {
+ /* initialize the fragmenter state */
+ fs.msg = msg;
+ fs.frag_nr = 0;
+ fs.next_byte = msg->data;
+ fs.sne = sne;
+ fs.mmcontext = mmcontext;
+
+ /* call function to generate and send fragments until all
+ * of the N-PDU has been sent */
+ while (1) {
+ int rc = sndcp_send_ud_frag(&fs,pcomp,dcomp);
+ if (rc == 0)
+ return 0;
+ if (rc < 0)
+ return rc;
+ }
+ /* not reached */
+ return 0;
+ }
+
+ /* this is the non-fragmenting case where we only build 1 SN-PDU */
+
+ /* prepend the user-data header */
+ suh = (struct sndcp_udata_hdr *) msgb_push(msg, sizeof(*suh));
+ suh->npdu_low = sne->tx_npdu_nr & 0xff;
+ suh->npdu_high = (sne->tx_npdu_nr >> 8) & 0xf;
+ suh->seg_nr = 0;
+ sne->tx_npdu_nr = (sne->tx_npdu_nr + 1) % 0xfff;
+
+ scomph = (struct sndcp_comp_hdr *) msgb_push(msg, sizeof(*scomph));
+ scomph->pcomp = pcomp;
+ scomph->dcomp = dcomp;
+
+ /* prepend common SNDCP header */
+ sch = (struct sndcp_common_hdr *) msgb_push(msg, sizeof(*sch));
+ sch->first = 1;
+ sch->type = 1;
+ sch->nsapi = nsapi;
+
+ return gprs_llc_tx_ui(msg, lle->sapi, 0, mmcontext, true);
+}
+
+/* Section 5.1.2.17 LL-UNITDATA.ind */
+int sndcp_llunitdata_ind(struct msgb *msg, struct gprs_llc_lle *lle,
+ uint8_t *hdr, uint16_t len)
+{
+ struct gprs_sndcp_entity *sne;
+ struct sndcp_common_hdr *sch = (struct sndcp_common_hdr *)hdr;
+ struct sndcp_comp_hdr *scomph = NULL;
+ struct sndcp_udata_hdr *suh;
+ uint8_t *npdu;
+ uint16_t npdu_num __attribute__((unused));
+ int npdu_len;
+ int rc;
+ uint8_t *expnd = NULL;
+
+ sch = (struct sndcp_common_hdr *) hdr;
+ if (sch->first) {
+ scomph = (struct sndcp_comp_hdr *) (hdr + 1);
+ suh = (struct sndcp_udata_hdr *) (hdr + 1 + sizeof(struct sndcp_common_hdr));
+ } else
+ suh = (struct sndcp_udata_hdr *) (hdr + sizeof(struct sndcp_common_hdr));
+
+ if (sch->type == 0) {
+ LOGP(DSNDCP, LOGL_ERROR, "SN-DATA PDU at unitdata_ind() function\n");
+ return -EINVAL;
+ }
+
+ if (len < sizeof(*sch) + sizeof(*suh)) {
+ LOGP(DSNDCP, LOGL_ERROR, "SN-UNITDATA PDU too short (%u)\n", len);
+ return -EIO;
+ }
+
+ sne = gprs_sndcp_entity_by_lle(lle, sch->nsapi);
+ if (!sne) {
+ LOGP(DSNDCP, LOGL_ERROR, "Message for non-existing SNDCP Entity "
+ "(lle=%p, TLLI=%08x, SAPI=%u, NSAPI=%u)\n", lle,
+ lle->llme->tlli, lle->sapi, sch->nsapi);
+ return -EIO;
+ }
+ /* FIXME: move this RA_ID up to the LLME or even higher */
+ bssgp_parse_cell_id(&sne->ra_id, msgb_bcid(msg));
+
+ if (scomph) {
+ sne->defrag.pcomp = scomph->pcomp;
+ sne->defrag.dcomp = scomph->dcomp;
+ sne->defrag.proto = lle->llme->comp.proto;
+ sne->defrag.data = lle->llme->comp.data;
+ }
+
+ /* any non-first segment is by definition something to defragment
+ * as is any segment that tells us there are more segments */
+ if (!sch->first || sch->more)
+ return defrag_input(sne, msg, hdr, len);
+
+ npdu_num = (suh->npdu_high << 8) | suh->npdu_low;
+ npdu = (uint8_t *)suh + sizeof(*suh);
+ npdu_len = (msg->data + msg->len) - npdu - 3; /* -3 'removes' the FCS */
+
+ if (npdu_len <= 0) {
+ LOGP(DSNDCP, LOGL_ERROR, "Short SNDCP N-PDU: %d\n", npdu_len);
+ return -EIO;
+ }
+ /* actually send the N-PDU to the SGSN core code, which then
+ * hands it off to the correct GTP tunnel + GGSN via gtp_data_req() */
+
+ /* Decompress packet */
+#if DEBUG_IP_PACKETS == 1
+ DEBUGP(DSNDCP, " \n");
+ DEBUGP(DSNDCP, ":::::::::::::::::::::::::::::::::::::::::::::::::::\n");
+ DEBUGP(DSNDCP, "===================================================\n");
+#endif
+ if (any_pcomp_or_dcomp_active(sgsn)) {
+
+ expnd = talloc_zero_size(msg, npdu_len * MAX_DATADECOMPR_FAC +
+ MAX_HDRDECOMPR_INCR);
+ memcpy(expnd, npdu, npdu_len);
+
+ /* Apply data decompression */
+ rc = gprs_sndcp_dcomp_expand(expnd, npdu_len, sne->defrag.dcomp,
+ sne->defrag.data);
+ if (rc < 0) {
+ LOGP(DSNDCP, LOGL_ERROR,
+ "Data decompression failed!\n");
+ talloc_free(expnd);
+ return -EIO;
+ }
+
+ /* Apply header decompression */
+ rc = gprs_sndcp_pcomp_expand(expnd, rc, sne->defrag.pcomp,
+ sne->defrag.proto);
+ if (rc < 0) {
+ LOGP(DSNDCP, LOGL_ERROR,
+ "TCP/IP Header decompression failed!\n");
+ talloc_free(expnd);
+ return -EIO;
+ }
+
+ /* Modify npu length, expnd is handed directly handed
+ * over to gsn_rx_sndcp_ud_ind(), see below */
+ npdu_len = rc;
+ } else
+ expnd = npdu;
+#if DEBUG_IP_PACKETS == 1
+ debug_ip_packet(expnd, npdu_len, 1, "sndcp_llunitdata_ind()");
+ DEBUGP(DSNDCP, "===================================================\n");
+ DEBUGP(DSNDCP, ":::::::::::::::::::::::::::::::::::::::::::::::::::\n");
+ DEBUGP(DSNDCP, " \n");
+#endif
+
+ /* Hand off packet to gtp */
+ rc = sgsn_rx_sndcp_ud_ind(&sne->ra_id, lle->llme->tlli,
+ sne->nsapi, msg, npdu_len, expnd);
+
+ if (any_pcomp_or_dcomp_active(sgsn))
+ talloc_free(expnd);
+
+ return rc;
+}
+
+#if 0
+/* Section 5.1.2.1 LL-RESET.ind */
+static int sndcp_ll_reset_ind(struct gprs_sndcp_entity *se)
+{
+ /* treat all outstanding SNDCP-LLC request type primitives as not sent */
+ /* reset all SNDCP XID parameters to default values */
+ LOGP(DSNDCP, LOGL_NOTICE, "not implemented.\n");
+ return 0;
+}
+
+static int sndcp_ll_status_ind()
+{
+ /* inform the SM sub-layer by means of SNSM-STATUS.req */
+ LOGP(DSNDCP, LOGL_NOTICE, "not implemented.\n");
+ return 0;
+}
+
+static struct sndcp_state_list {{
+ uint32_t states;
+ unsigned int type;
+ int (*rout)(struct gprs_sndcp_entity *se, struct msgb *msg);
+} sndcp_state_list[] = {
+ { ALL_STATES,
+ LL_RESET_IND, sndcp_ll_reset_ind },
+ { ALL_STATES,
+ LL_ESTABLISH_IND, sndcp_ll_est_ind },
+ { SBIT(SNDCP_S_EST_RQD),
+ LL_ESTABLISH_RESP, sndcp_ll_est_ind },
+ { SBIT(SNDCP_S_EST_RQD),
+ LL_ESTABLISH_CONF, sndcp_ll_est_conf },
+ { SBIT(SNDCP_S_
+};
+
+static int sndcp_rx_llc_prim()
+{
+ case LL_ESTABLISH_REQ:
+ case LL_RELEASE_REQ:
+ case LL_XID_REQ:
+ case LL_DATA_REQ:
+ LL_UNITDATA_REQ, /* TLLI, SN-PDU, Ref, QoS, Radio Prio, Ciph */
+
+ switch (prim) {
+ case LL_RESET_IND:
+ case LL_ESTABLISH_IND:
+ case LL_ESTABLISH_RESP:
+ case LL_ESTABLISH_CONF:
+ case LL_RELEASE_IND:
+ case LL_RELEASE_CONF:
+ case LL_XID_IND:
+ case LL_XID_RESP:
+ case LL_XID_CONF:
+ case LL_DATA_IND:
+ case LL_DATA_CONF:
+ case LL_UNITDATA_IND:
+ case LL_STATUS_IND:
+ }
+}
+#endif
+
+/* Generate SNDCP-XID message */
+static int gprs_llc_gen_sndcp_xid(uint8_t *bytes, int bytes_len, uint8_t nsapi)
+{
+ int entity = 0;
+ LLIST_HEAD(comp_fields);
+ struct gprs_sndcp_pcomp_rfc1144_params rfc1144_params;
+ struct gprs_sndcp_comp_field rfc1144_comp_field;
+ struct gprs_sndcp_dcomp_v42bis_params v42bis_params;
+ struct gprs_sndcp_comp_field v42bis_comp_field;
+
+ memset(&rfc1144_comp_field, 0, sizeof(struct gprs_sndcp_comp_field));
+ memset(&v42bis_comp_field, 0, sizeof(struct gprs_sndcp_comp_field));
+
+ /* Setup rfc1144 */
+ if (sgsn->cfg.pcomp_rfc1144.active) {
+ rfc1144_params.nsapi[0] = nsapi;
+ rfc1144_params.nsapi_len = 1;
+ rfc1144_params.s01 = sgsn->cfg.pcomp_rfc1144.s01;
+ rfc1144_comp_field.p = 1;
+ rfc1144_comp_field.entity = entity;
+ rfc1144_comp_field.algo = RFC_1144;
+ rfc1144_comp_field.comp[RFC1144_PCOMP1] = 1;
+ rfc1144_comp_field.comp[RFC1144_PCOMP2] = 2;
+ rfc1144_comp_field.comp_len = RFC1144_PCOMP_NUM;
+ rfc1144_comp_field.rfc1144_params = &rfc1144_params;
+ entity++;
+ llist_add(&rfc1144_comp_field.list, &comp_fields);
+ }
+
+ /* Setup V.42bis */
+ if (sgsn->cfg.dcomp_v42bis.active) {
+ v42bis_params.nsapi[0] = nsapi;
+ v42bis_params.nsapi_len = 1;
+ v42bis_params.p0 = sgsn->cfg.dcomp_v42bis.p0;
+ v42bis_params.p1 = sgsn->cfg.dcomp_v42bis.p1;
+ v42bis_params.p2 = sgsn->cfg.dcomp_v42bis.p2;
+ v42bis_comp_field.p = 1;
+ v42bis_comp_field.entity = entity;
+ v42bis_comp_field.algo = V42BIS;
+ v42bis_comp_field.comp[V42BIS_DCOMP1] = 1;
+ v42bis_comp_field.comp_len = V42BIS_DCOMP_NUM;
+ v42bis_comp_field.v42bis_params = &v42bis_params;
+ entity++;
+ llist_add(&v42bis_comp_field.list, &comp_fields);
+ }
+
+ /* Do not attempt to compile anything if there is no data in the list */
+ if (llist_empty(&comp_fields))
+ return 0;
+
+ /* Compile bytestream */
+ return gprs_sndcp_compile_xid(bytes, bytes_len, &comp_fields,
+ DEFAULT_SNDCP_VERSION);
+}
+
+/* Set of SNDCP-XID bnegotiation (See also: TS 144 065,
+ * Section 6.8 XID parameter negotiation) */
+int sndcp_sn_xid_req(struct gprs_llc_lle *lle, uint8_t nsapi)
+{
+ /* Note: The specification requires the SNDCP-User to set of an
+ * SNDCP xid request. See also 3GPP TS 44.065, 6.8 XID parameter
+ * negotiation, Figure 11: SNDCP XID negotiation procedure. In
+ * our case the SNDCP-User is sgsn_libgtp.c, which calls
+ * sndcp_sn_xid_req directly. */
+
+ uint8_t l3params[1024];
+ int xid_len;
+ struct gprs_llc_xid_field xid_field_request;
+
+ /* Wipe off all compression entities and their states to
+ * get rid of possible leftovers from a previous session */
+ gprs_sndcp_comp_free(lle->llme->comp.proto);
+ gprs_sndcp_comp_free(lle->llme->comp.data);
+ lle->llme->comp.proto = gprs_sndcp_comp_alloc(lle->llme);
+ lle->llme->comp.data = gprs_sndcp_comp_alloc(lle->llme);
+ talloc_free(lle->llme->xid);
+ lle->llme->xid = NULL;
+
+ /* Generate compression parameter bytestream */
+ xid_len = gprs_llc_gen_sndcp_xid(l3params, sizeof(l3params), nsapi);
+
+ /* Send XID with the SNDCP-XID bytetsream included */
+ if (xid_len > 0) {
+ xid_field_request.type = GPRS_LLC_XID_T_L3_PAR;
+ xid_field_request.data = l3params;
+ xid_field_request.data_len = xid_len;
+ return gprs_ll_xid_req(lle, &xid_field_request);
+ }
+
+ /* When bytestream can not be generated, proceed without SNDCP-XID */
+ return gprs_ll_xid_req(lle, NULL);
+
+}
+
+/* Handle header compression entites */
+static int handle_pcomp_entities(struct gprs_sndcp_comp_field *comp_field,
+ struct gprs_llc_lle *lle)
+{
+ /* Note: This functions also transforms the comp_field into its
+ * echo form (strips comp values, resets propose bit etc...)
+ * the processed comp_fields can then be sent back as XID-
+ * Response without further modification. */
+
+ /* Delete propose bit */
+ comp_field->p = 0;
+
+ /* Process proposed parameters */
+ switch (comp_field->algo) {
+ case RFC_1144:
+ if (sgsn->cfg.pcomp_rfc1144.passive
+ && comp_field->rfc1144_params->nsapi_len > 0) {
+ DEBUGP(DSNDCP,
+ "Accepting RFC1144 header compression...\n");
+ gprs_sndcp_comp_add(lle->llme, lle->llme->comp.proto,
+ comp_field);
+ } else {
+ DEBUGP(DSNDCP,
+ "Rejecting RFC1144 header compression...\n");
+ gprs_sndcp_comp_delete(lle->llme->comp.proto,
+ comp_field->entity);
+ comp_field->rfc1144_params->nsapi_len = 0;
+ }
+ break;
+ case RFC_2507:
+ /* RFC 2507 is not yet supported,
+ * so we set applicable nsapis to zero */
+ DEBUGP(DSNDCP, "Rejecting RFC2507 header compression...\n");
+ comp_field->rfc2507_params->nsapi_len = 0;
+ gprs_sndcp_comp_delete(lle->llme->comp.proto,
+ comp_field->entity);
+ break;
+ case ROHC:
+ /* ROHC is not yet supported,
+ * so we set applicable nsapis to zero */
+ DEBUGP(DSNDCP, "Rejecting ROHC header compression...\n");
+ comp_field->rohc_params->nsapi_len = 0;
+ gprs_sndcp_comp_delete(lle->llme->comp.proto,
+ comp_field->entity);
+ break;
+ }
+
+ return 0;
+}
+
+/* Hanle data compression entites */
+static int handle_dcomp_entities(struct gprs_sndcp_comp_field *comp_field,
+ struct gprs_llc_lle *lle)
+{
+ /* See note in handle_pcomp_entities() */
+
+ /* Delete propose bit */
+ comp_field->p = 0;
+
+ /* Process proposed parameters */
+ switch (comp_field->algo) {
+ case V42BIS:
+ if (sgsn->cfg.dcomp_v42bis.passive &&
+ comp_field->v42bis_params->nsapi_len > 0) {
+ DEBUGP(DSNDCP,
+ "Accepting V.42bis data compression...\n");
+ gprs_sndcp_comp_add(lle->llme, lle->llme->comp.data,
+ comp_field);
+ } else {
+ LOGP(DSNDCP, LOGL_DEBUG,
+ "Rejecting V.42bis data compression...\n");
+ gprs_sndcp_comp_delete(lle->llme->comp.data,
+ comp_field->entity);
+ comp_field->v42bis_params->nsapi_len = 0;
+ }
+ break;
+ case V44:
+ /* V44 is not yet supported,
+ * so we set applicable nsapis to zero */
+ DEBUGP(DSNDCP, "Rejecting V.44 data compression...\n");
+ comp_field->v44_params->nsapi_len = 0;
+ gprs_sndcp_comp_delete(lle->llme->comp.data,
+ comp_field->entity);
+ break;
+ }
+
+ return 0;
+
+}
+
+/* Process SNDCP-XID indication
+ * (See also: TS 144 065, Section 6.8 XID parameter negotiation) */
+int sndcp_sn_xid_ind(struct gprs_llc_xid_field *xid_field_indication,
+ struct gprs_llc_xid_field *xid_field_response,
+ struct gprs_llc_lle *lle)
+{
+ /* Note: This function computes the SNDCP-XID response that is sent
+ * back to the ms when a ms originated XID is received. The
+ * Input XID fields are directly processed and the result is directly
+ * handed back. */
+
+ int rc;
+ int compclass;
+ int version;
+
+ struct llist_head *comp_fields;
+ struct gprs_sndcp_comp_field *comp_field;
+
+ OSMO_ASSERT(xid_field_indication);
+ OSMO_ASSERT(xid_field_response);
+ OSMO_ASSERT(lle);
+
+ /* Parse SNDCP-CID XID-Field */
+ comp_fields = gprs_sndcp_parse_xid(&version, lle->llme,
+ xid_field_indication->data,
+ xid_field_indication->data_len,
+ NULL);
+ if (!comp_fields)
+ return -EINVAL;
+
+ /* Handle compression entites */
+ DEBUGP(DSNDCP, "SNDCP-XID-IND (ms):\n");
+ gprs_sndcp_dump_comp_fields(comp_fields, LOGL_DEBUG);
+
+ llist_for_each_entry(comp_field, comp_fields, list) {
+ compclass = gprs_sndcp_get_compression_class(comp_field);
+ if (compclass == SNDCP_XID_PROTOCOL_COMPRESSION)
+ rc = handle_pcomp_entities(comp_field, lle);
+ else if (compclass == SNDCP_XID_DATA_COMPRESSION)
+ rc = handle_dcomp_entities(comp_field, lle);
+ else {
+ gprs_sndcp_comp_delete(lle->llme->comp.proto,
+ comp_field->entity);
+ gprs_sndcp_comp_delete(lle->llme->comp.data,
+ comp_field->entity);
+ rc = 0;
+ }
+
+ if (rc < 0) {
+ talloc_free(comp_fields);
+ return -EINVAL;
+ }
+ }
+
+ DEBUGP(DSNDCP, "SNDCP-XID-RES (sgsn):\n");
+ gprs_sndcp_dump_comp_fields(comp_fields, LOGL_DEBUG);
+
+ /* Reserve some memory to store the modified SNDCP-XID bytes */
+ xid_field_response->data =
+ talloc_zero_size(lle->llme, xid_field_indication->data_len);
+
+ /* Set Type flag for response */
+ xid_field_response->type = GPRS_LLC_XID_T_L3_PAR;
+
+ /* Compile modified SNDCP-XID bytes */
+ rc = gprs_sndcp_compile_xid(xid_field_response->data,
+ xid_field_indication->data_len,
+ comp_fields, 0);
+
+ if (rc > 0)
+ xid_field_response->data_len = rc;
+ else {
+ talloc_free(xid_field_response->data);
+ xid_field_response->data = NULL;
+ xid_field_response->data_len = 0;
+ return -EINVAL;
+ }
+
+ talloc_free(comp_fields);
+
+ return 0;
+}
+
+/* Process SNDCP-XID indication
+ * (See also: TS 144 065, Section 6.8 XID parameter negotiation) */
+int sndcp_sn_xid_conf(struct gprs_llc_xid_field *xid_field_conf,
+ struct gprs_llc_xid_field *xid_field_request,
+ struct gprs_llc_lle *lle)
+{
+ /* Note: This function handles an incomming SNDCP-XID confirmiation.
+ * Since the confirmation fields may lack important parameters we
+ * will reconstruct these missing fields using the original request
+ * we have sent. After that we will create (or delete) the
+ * compression entites */
+
+ struct llist_head *comp_fields_req;
+ struct llist_head *comp_fields_conf;
+ struct gprs_sndcp_comp_field *comp_field;
+ int rc;
+ int compclass;
+
+ /* We need both, the confirmation that is sent back by the ms,
+ * and the original request we have sent. If one of this is missing
+ * we can not process the confirmation, the caller must check if
+ * request and confirmation fields are available. */
+ OSMO_ASSERT(xid_field_conf);
+ OSMO_ASSERT(xid_field_request);
+
+ /* Parse SNDCP-CID XID-Field */
+ comp_fields_req = gprs_sndcp_parse_xid(NULL, lle->llme,
+ xid_field_request->data,
+ xid_field_request->data_len,
+ NULL);
+ if (!comp_fields_req)
+ return -EINVAL;
+
+ DEBUGP(DSNDCP, "SNDCP-XID-REQ (sgsn):\n");
+ gprs_sndcp_dump_comp_fields(comp_fields_req, LOGL_DEBUG);
+
+ /* Parse SNDCP-CID XID-Field */
+ comp_fields_conf = gprs_sndcp_parse_xid(NULL, lle->llme,
+ xid_field_conf->data,
+ xid_field_conf->data_len,
+ comp_fields_req);
+ if (!comp_fields_conf)
+ return -EINVAL;
+
+ DEBUGP(DSNDCP, "SNDCP-XID-CONF (ms):\n");
+ gprs_sndcp_dump_comp_fields(comp_fields_conf, LOGL_DEBUG);
+
+ /* Handle compression entites */
+ llist_for_each_entry(comp_field, comp_fields_conf, list) {
+ compclass = gprs_sndcp_get_compression_class(comp_field);
+ if (compclass == SNDCP_XID_PROTOCOL_COMPRESSION)
+ rc = handle_pcomp_entities(comp_field, lle);
+ else if (compclass == SNDCP_XID_DATA_COMPRESSION)
+ rc = handle_dcomp_entities(comp_field, lle);
+ else {
+ gprs_sndcp_comp_delete(lle->llme->comp.proto,
+ comp_field->entity);
+ gprs_sndcp_comp_delete(lle->llme->comp.data,
+ comp_field->entity);
+ rc = 0;
+ }
+
+ if (rc < 0) {
+ talloc_free(comp_fields_req);
+ talloc_free(comp_fields_conf);
+ return -EINVAL;
+ }
+ }
+
+ talloc_free(comp_fields_req);
+ talloc_free(comp_fields_conf);
+
+ return 0;
+}