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osmo-sgsn
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[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.
This commit is contained in:
Harald Welte 2010-06-01 18:28:10 +02:00
parent 84488245e6
commit ebabdea0a6
5 changed files with 205 additions and 19 deletions
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8
openbsc/include/openbsc/sgsn.h
View File

@ -50,4 +50,12 @@ struct sgsn_pdp_ctx *sgsn_create_pdp_ctx(struct sgsn_ggsn_ctx *ggsn,
struct tlv_parsed *tp);
int sgsn_delete_pdp_ctx(struct sgsn_pdp_ctx *pctx);
/* gprs_sndcp.c */
/* Entry point for the SNSM-ACTIVATE.indication */
int sndcp_sm_activate_ind(struct gprs_llc_lle *lle, uint8_t nsapi);
/* 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);
#endif

2
openbsc/src/gprs/Makefile.am
View File

@ -19,7 +19,7 @@ osmo_gbproxy_SOURCES = gb_proxy.c gb_proxy_main.c gb_proxy_vty.c \
$(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

19
openbsc/src/gprs/gprs_llc.c
View File

@ -340,6 +340,15 @@ static int gprs_llc_hdr_rx(struct gprs_llc_hdr_parsed *gph,
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 @@ int gprs_llc_rcvmsg(struct msgb *msg, struct tlv_parsed *tv)
/* 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;

160
openbsc/src/gprs/gprs_sndcp.c
View File

@ -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 @@ struct sndcp_common_hdr {
/* octet 2 */
uint8_t pcomp;
uint8_t dcomp;
};
} __attribute__((packed));
struct sndcp_udata_hdr {
/* octet 3 */
@ -52,42 +53,172 @@ struct sndcp_udata_hdr {
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 @@ static int sndcp_rx_llc_prim()
case LL_UNITDATA_IND:
case LL_STATUS_IND:
}
#endif

35
openbsc/src/gprs/sgsn_libgtp.c
View File

@ -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 @@ static int create_pdp_conf(struct pdp_t *pdp, void *cbp, int cause)
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 @@ static int cb_data_ind(struct pdp_t *pdp, void *packet, unsigned int len)
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)
{