[GPRS] hand SNDCP N-PDUs to the GTP to the GGSN
This so far only works for UNIT-DATA and only if the N-PDU is not fragmented at
the SNDCP layer.
diff --git a/openbsc/src/gprs/Makefile.am b/openbsc/src/gprs/Makefile.am
index 11b2ac9..30b45f6 100644
--- a/openbsc/src/gprs/Makefile.am
+++ b/openbsc/src/gprs/Makefile.am
@@ -19,7 +19,7 @@
$(top_srcdir)/src/socket.c $(top_srcdir)/src/debug.c
osmo_gbproxy_LDADD = libgb.a $(top_builddir)/src/libvty.a
-osmo_sgsn_SOURCES = gprs_gmm.c gprs_sgsn.c \
+osmo_sgsn_SOURCES = gprs_gmm.c gprs_sgsn.c gprs_sndcp.c \
sgsn_main.c sgsn_vty.c sgsn_libgtp.c \
$(top_srcdir)/src/socket.c $(top_srcdir)/src/debug.c
osmo_sgsn_LDADD = libgb.a $(top_builddir)/src/libvty.a -lgtp
diff --git a/openbsc/src/gprs/gprs_llc.c b/openbsc/src/gprs/gprs_llc.c
index 26730d4..cb581f1 100644
--- a/openbsc/src/gprs/gprs_llc.c
+++ b/openbsc/src/gprs/gprs_llc.c
@@ -340,6 +340,15 @@
gprs_llc_tx_xid(lle, resp);
}
break;
+ case GPRS_LLC_UI:
+ if (gph->seq_tx < lle->vu_recv) {
+ LOGP(DLLC, "TLLI=%08x dropping UI, vurecv %u <= %u\n",
+ gph->seq_tx, lle->vu_recv);
+ return -EIO;
+ }
+ /* Increment the sequence number that we expect in the next frame */
+ lle->vu_recv = (gph->seq_tx + 1) % 512;
+ break;
}
return 0;
@@ -583,16 +592,18 @@
/* send LL_UNITDATA_IND to GMM */
rc = gsm0408_gprs_rcvmsg(msg, lle->llme);
break;
- case GPRS_SAPI_TOM2:
- case GPRS_SAPI_TOM8:
- /* FIXME: send LL_DATA_IND/LL_UNITDATA_IND to TOM */
case GPRS_SAPI_SNDCP3:
case GPRS_SAPI_SNDCP5:
case GPRS_SAPI_SNDCP9:
case GPRS_SAPI_SNDCP11:
- /* FIXME: send LL_DATA_IND/LL_UNITDATA_IND to SNDCP */
+ /* 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;
diff --git a/openbsc/src/gprs/gprs_sndcp.c b/openbsc/src/gprs/gprs_sndcp.c
index 99a7638..ec704e0 100644
--- a/openbsc/src/gprs/gprs_sndcp.c
+++ b/openbsc/src/gprs/gprs_sndcp.c
@@ -32,6 +32,7 @@
#include <openbsc/debug.h>
#include <openbsc/gprs_bssgp.h>
#include <openbsc/gprs_llc.h>
+#include <openbsc/sgsn.h>
/* Chapter 7.2: SN-PDU Formats */
struct sndcp_common_hdr {
@@ -44,7 +45,7 @@
/* octet 2 */
uint8_t pcomp;
uint8_t dcomp;
-};
+} __attribute__((packed));
struct sndcp_udata_hdr {
/* octet 3 */
@@ -52,42 +53,172 @@
uint8_t seg_nr:4;
/* octet 4 */
uint8_t npdu_low;
+} __attribute__((packed));
+
+/* See 6.7.1.2 Reassembly */
+enum sndcp_rx_state {
+ SNDCP_RX_S_FIRST,
+ SNDCP_RX_S_SUBSEQ,
+ SNDCP_RX_S_DISCARD,
+};
+
+
+static void *tall_sndcp_ctx;
+
+/* A fragment queue entry, containing one framgent of a N-PDU */
+struct frag_queue_entry {
+ struct llist_head list;
+ uint8_t seg_nr;
+ uint32_t data_len;
+ uint8_t data[0];
+};
+
+/* A fragment queue header, maintaining list of fragments for one N-PDU */
+struct frag_queue_head {
+ uint16_t npdu;
+
+ /* linked list of frag_queue_entry: one for each fragment */
+ struct llist_head frag_list;
+
+ struct timer_list timer;
};
struct sndcp_entity {
+ struct llist_head list;
+
+ struct gprs_llc_lle *lle;
+ uint8_t nsapi;
+
+ enum sndcp_rx_state rx_state;
+ struct frag_queue_head fqueue;
};
-/* Entry point for the LL-UNITDATA.indication */
-int sndcp_unitdata_ind(struct msgb *msg, uint8_t sapi, uint8_t *hdr, uint8_t len)
-{
- struct sndcp_udata_hdr *suh;
- uint16_t npdu;
+LLIST_HEAD(sndcp_entities);
- if (suh->type == 0) {
+#if 0
+static struct frag_queue_entry _find_fqe(struct freg_queue_head *fqh, uint8_t seg_nr)
+{
+
+}
+
+static struct frag_queue_head _find_fqh(struct sndcp_entity *sne, uint16_t npdu)
+{
+
+}
+
+static int ul_enqueue_fragment(struct sndcp_entity *sne, uint16_t npdu,
+ uint8_t seg_nr, uint32_t data_len, uint8_t *data)
+{
+
+}
+#endif
+
+static struct sndcp_entity *sndcp_entity_by_lle(const struct gprs_llc_lle *lle,
+ uint8_t nsapi)
+{
+ struct sndcp_entity *sne;
+
+ llist_for_each_entry(sne, &sndcp_entities, list) {
+ if (sne->lle == lle && sne->nsapi == nsapi)
+ return sne;
+ }
+ return NULL;
+}
+
+static struct sndcp_entity *sndcp_entity_alloc(struct gprs_llc_lle *lle,
+ uint8_t nsapi)
+{
+ struct sndcp_entity *sne;
+
+ sne = talloc_zero(tall_sndcp_ctx, struct sndcp_entity);
+ if (!sne)
+ return NULL;
+
+ sne->lle = lle;
+ sne->nsapi = nsapi;
+ sne->fqueue.timer.data = sne;
+ //sne->fqueue.timer.cb = FIXME;
+ sne->rx_state = SNDCP_RX_S_FIRST;
+
+ return sne;
+}
+
+/* Entry point for the SNSM-ACTIVATE.indication */
+int sndcp_sm_activate_ind(struct gprs_llc_lle *lle, uint8_t nsapi)
+{
+ if (sndcp_entity_by_lle(lle, nsapi))
+ return -EEXIST;
+
+ if (!sndcp_entity_alloc(lle, nsapi))
+ return -ENOMEM;
+
+ return 0;
+}
+
+/* Section 5.1.2.17 LL-UNITDATA.ind */
+int sndcp_llunitdata_ind(struct msgb *msg, struct gprs_llc_lle *lle, uint8_t *hdr, uint8_t len)
+{
+ struct sndcp_entity *sne;
+ struct sndcp_common_hdr *sch = (struct sndcp_common_hdr *)hdr;
+ struct sndcp_udata_hdr *suh;
+ uint8_t *comp, *npdu;
+ uint16_t npdu_num;
+ int npdu_len;
+
+ if (sch->type == 0) {
LOGP(DGPRS, LOGL_ERROR, "SN-DATA PDU at unitdata_ind() function\n");
return -EINVAL;
}
- npdu = (suh->npdu_high << 8) | suh->npdu_low;
+ if (len < sizeof(*sch) + sizeof(*comp) + sizeof(*suh)) {
+ LOGP(DGPRS, LOGL_ERROR, "SN-UNITDATA PDU too short (%u)\n", len);
+ return -EIO;
+ }
+
+ sne = sndcp_entity_by_lle(lle, sch->nsapi);
+ if (!sne) {
+ LOGP(DGPRS, LOGL_ERROR, "Message for non-existing SNDCP Entity\n");
+ return -EIO;
+ }
+
+ if (!sch->first || sch->more) {
+ /* FIXME: implement fragment re-assembly */
+ LOGP(DGPRS, LOGL_ERROR, "We don't support reassembly yet\n");
+ return -EIO;
+ }
+
+ comp = (hdr + sizeof(struct sndcp_common_hdr));
+ if (comp) {
+ LOGP(DGPRS, LOGL_ERROR, "We don't support compression yet\n");
+ return -EIO;
+ }
+ suh = (struct sndcp_udata_hdr *) (comp + sizeof(*comp));
+ npdu_num = (suh->npdu_high << 8) | suh->npdu_low;
+
+ npdu = (uint8_t *)suh + sizeof(*suh);
+ npdu_len = (msg->data + msg->len) - npdu;
+ if (npdu_len) {
+ LOGP(DGPRS, 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() */
+ return sgsn_rx_sndcp_ud_ind(lle->llme->tlli, sne->nsapi, msg, npdu_len, npdu);
}
/* Section 5.1.2.1 LL-RESET.ind */
-static int sndcp_ll_reset_ind(struct sndcp_entity *se,)
+static int sndcp_ll_reset_ind(struct sndcp_entity *se)
{
/* treat all outstanding SNDCP-LLC request type primitives as not sent */
/* reset all SNDCP XID parameters to default values */
}
-/* Section 5.1.2.17 LL-UNITDATA.ind */
-static int sndcp_ll_unitdata_ind()
-{
-}
-
static int sndcp_ll_status_ind()
{
/* inform the SM sub-layer by means of SNSM-STATUS.req */
}
+#if 0
static struct sndcp_state_list {{
uint32_t states;
unsigned int type;
@@ -127,3 +258,4 @@
case LL_UNITDATA_IND:
case LL_STATUS_IND:
}
+#endif
diff --git a/openbsc/src/gprs/sgsn_libgtp.c b/openbsc/src/gprs/sgsn_libgtp.c
index 7df9325..03de8cc 100644
--- a/openbsc/src/gprs/sgsn_libgtp.c
+++ b/openbsc/src/gprs/sgsn_libgtp.c
@@ -42,6 +42,8 @@
#include <openbsc/signal.h>
#include <openbsc/debug.h>
#include <openbsc/sgsn.h>
+#include <openbsc/gprs_llc.h>
+#include <openbsc/gprs_bssgp.h>
#include <openbsc/gprs_sgsn.h>
#include <openbsc/gprs_gmm.h>
@@ -255,6 +257,9 @@
goto reject;
}
+ /* Activate the SNDCP layer */
+ sndcp_sm_activate_ind(&pctx->mm->llme->lle[pctx->sapi], pctx->nsapi);
+
/* Send PDP CTX ACT to MS */
return gsm48_tx_gsm_act_pdp_acc(pctx);
@@ -356,6 +361,36 @@
return 0;
}
+/* Called by SNDCP when it has received/re-assembled a N-PDU */
+int sgsn_rx_sndcp_ud_ind(uint32_t tlli, uint8_t nsapi, struct msgb *msg,
+ uint32_t npdu_len, uint8_t *npdu)
+{
+ struct sgsn_mm_ctx *mmctx;
+ struct sgsn_pdp_ctx *pdp;
+ struct gprs_ra_id ra_id;
+
+ /* look-up the MM context for this message */
+ bssgp_parse_cell_id(&ra_id, msgb_bcid(msg));
+ mmctx = sgsn_mm_ctx_by_tlli(tlli, &ra_id);
+ if (!mmctx) {
+ LOGP(DGPRS, LOGL_ERROR,
+ "Cannot find MM CTX for TLLI %08x\n", tlli);
+ return -EIO;
+ }
+ /* look-up the PDP context for this message */
+ pdp = sgsn_pdp_ctx_by_nsapi(mmctx, nsapi);
+ if (!pdp) {
+ LOGP(DGPRS, LOGL_ERROR, "Cannot find PDP CTX for "
+ "TLLI=%08x, NSAPI=%u\n", tlli, nsapi);
+ return -EIO;
+ }
+ if (!pdp->lib) {
+ LOGP(DGPRS, LOGL_ERROR, "PDP CTX without libgtp\n");
+ return -EIO;
+ }
+ return gtp_data_req(pdp->ggsn->gsn, pdp->lib, npdu, npdu_len);
+}
+
/* libgtp select loop integration */
static int sgsn_gtp_fd_cb(struct bsc_fd *fd, unsigned int what)
{