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authorJacob Erlbeck <jerlbeck@sysmocom.de>2014-09-30 13:49:43 +0200
committerJacob Erlbeck <jerlbeck@sysmocom.de>2014-10-27 11:59:28 +0100
commitc37ef6cd0e535558b1cc672aa3964eeb506b3f25 (patch)
treee578c0edacae26f6f01a68706296e235dc19d875
parent91e9f555b6a091663c192c9cd3b8d022a2690eed (diff)
gbproxy: Patch BSSGP P-TMSI in PAGING PS messages
Currently the P-TMSI IE in PAGING_PS is not patched. This commit adds code to patch BSSGP P-TMSI IE in gbproxy_patch_bssgp independently from the P-TMSI patching at the LLC layer. It also extends gbproxy_update_link_state_dl to use the IMSI to find the link_info if the TLLI is not present in the message. Note that the spec (GSM 08.18, 7.2) requires to use of the P-TMSI instead of the IMSI to select the MS if that IE is available. Nevertheless as long as the IMSI is always present in downlink BSSGP messages and as long as the optional P-TMSI refers to the same MS (which is the case currently), this is not an issue. Sponsored-by: On-Waves ehf
-rw-r--r--openbsc/include/openbsc/gprs_gb_parse.h2
-rw-r--r--openbsc/src/gprs/gb_proxy_patch.c13
-rw-r--r--openbsc/src/gprs/gb_proxy_tlli.c28
-rw-r--r--openbsc/src/gprs/gprs_gb_parse.c10
-rw-r--r--openbsc/tests/gbproxy/gbproxy_test.c57
-rw-r--r--openbsc/tests/gbproxy/gbproxy_test.ok32
6 files changed, 133 insertions, 9 deletions
diff --git a/openbsc/include/openbsc/gprs_gb_parse.h b/openbsc/include/openbsc/gprs_gb_parse.h
index 4dc5f6ff1..246839286 100644
--- a/openbsc/include/openbsc/gprs_gb_parse.h
+++ b/openbsc/include/openbsc/gprs_gb_parse.h
@@ -29,7 +29,7 @@ struct gprs_gb_parse_context {
uint8_t *raid_enc;
uint8_t *old_raid_enc;
uint8_t *bssgp_raid_enc;
- uint8_t *bssgp_ptimsi;
+ uint8_t *bssgp_ptmsi_enc;
/* General info */
const char *llc_msg_name;
diff --git a/openbsc/src/gprs/gb_proxy_patch.c b/openbsc/src/gprs/gb_proxy_patch.c
index b14809495..c1d2497db 100644
--- a/openbsc/src/gprs/gb_proxy_patch.c
+++ b/openbsc/src/gprs/gb_proxy_patch.c
@@ -327,6 +327,19 @@ void gbproxy_patch_bssgp(struct msgb *msg, uint8_t *bssgp, size_t bssgp_len,
}
}
+ if (parse_ctx->bssgp_ptmsi_enc && peer->cfg->patch_ptmsi) {
+ uint32_t ptmsi;
+ if (parse_ctx->to_bss)
+ ptmsi = link_info->tlli.ptmsi;
+ else
+ ptmsi = link_info->sgsn_tlli.ptmsi;
+
+ if (ptmsi != GSM_RESERVED_TMSI)
+ gbproxy_patch_ptmsi(
+ parse_ctx->bssgp_ptmsi_enc, peer,
+ ptmsi, parse_ctx->to_bss, "BSSGP P-TMSI");
+ }
+
if (parse_ctx->llc) {
uint8_t *llc = parse_ctx->llc;
size_t llc_len = parse_ctx->llc_len;
diff --git a/openbsc/src/gprs/gb_proxy_tlli.c b/openbsc/src/gprs/gb_proxy_tlli.c
index 467006e87..54e41e9e0 100644
--- a/openbsc/src/gprs/gb_proxy_tlli.c
+++ b/openbsc/src/gprs/gb_proxy_tlli.c
@@ -542,6 +542,30 @@ struct gbproxy_link_info *gbproxy_update_link_state_ul(
return link_info;
}
+static struct gbproxy_link_info *gbproxy_get_link_info_dl(
+ struct gbproxy_peer *peer,
+ struct gprs_gb_parse_context *parse_ctx)
+{
+ struct gbproxy_link_info *link_info = NULL;
+
+ /* Which key to use depends on its availability only, if that fails, do
+ * not retry it with another key (e.g. IMSI). */
+ if (parse_ctx->tlli_enc)
+ link_info = gbproxy_link_info_by_sgsn_tlli(peer, parse_ctx->tlli,
+ parse_ctx->peer_nsei);
+
+ /* TODO: Get link_info by (SGSN) P-TMSI if that is available (see
+ * GSM 08.18, 7.2) instead of using the IMSI as key. */
+ else if (parse_ctx->imsi)
+ link_info = gbproxy_link_info_by_imsi(
+ peer, parse_ctx->imsi, parse_ctx->imsi_len);
+
+ if (link_info)
+ link_info->is_deregistered = 0;
+
+ return link_info;
+}
+
struct gbproxy_link_info *gbproxy_update_link_state_dl(
struct gbproxy_peer *peer,
time_t now,
@@ -549,9 +573,7 @@ struct gbproxy_link_info *gbproxy_update_link_state_dl(
{
struct gbproxy_link_info *link_info = NULL;
- if (parse_ctx->tlli_enc)
- link_info = gbproxy_link_info_by_sgsn_tlli(
- peer, parse_ctx->tlli, parse_ctx->peer_nsei);
+ link_info = gbproxy_get_link_info_dl(peer, parse_ctx);
if (parse_ctx->tlli_enc && parse_ctx->new_ptmsi_enc && link_info) {
/* A new P-TMSI has been signalled in the message,
diff --git a/openbsc/src/gprs/gprs_gb_parse.c b/openbsc/src/gprs/gprs_gb_parse.c
index 8e72cc819..6c6371ca0 100644
--- a/openbsc/src/gprs/gprs_gb_parse.c
+++ b/openbsc/src/gprs/gprs_gb_parse.c
@@ -596,7 +596,7 @@ int gprs_gb_parse_bssgp(uint8_t *bssgp, size_t bssgp_len,
}
if (TLVP_PRESENT(tp, BSSGP_IE_TMSI) && pdu_type == BSSGP_PDUT_PAGING_PS)
- parse_ctx->ptmsi_enc = (uint8_t *)TLVP_VAL(tp, BSSGP_IE_TMSI);
+ parse_ctx->bssgp_ptmsi_enc = (uint8_t *)TLVP_VAL(tp, BSSGP_IE_TMSI);
if (TLVP_PRESENT(tp, BSSGP_IE_LLC_PDU)) {
uint8_t *llc = (uint8_t *)TLVP_VAL(tp, BSSGP_IE_LLC_PDU);
@@ -633,6 +633,7 @@ void gprs_gb_log_parse_context(int log_level,
if (!parse_ctx->tlli_enc &&
!parse_ctx->ptmsi_enc &&
!parse_ctx->new_ptmsi_enc &&
+ !parse_ctx->bssgp_ptmsi_enc &&
!parse_ctx->imsi)
return;
@@ -681,6 +682,13 @@ void gprs_gb_log_parse_context(int log_level,
sep = ",";
}
+ if (parse_ctx->bssgp_ptmsi_enc) {
+ uint32_t ptmsi = GSM_RESERVED_TMSI;
+ gprs_parse_tmsi(parse_ctx->bssgp_ptmsi_enc, &ptmsi);
+ LOGPC(DGPRS, log_level, "%s BSSGP PTMSI %08x", sep, ptmsi);
+ sep = ",";
+ }
+
if (parse_ctx->ptmsi_enc) {
uint32_t ptmsi = GSM_RESERVED_TMSI;
gprs_parse_tmsi(parse_ctx->ptmsi_enc, &ptmsi);
diff --git a/openbsc/tests/gbproxy/gbproxy_test.c b/openbsc/tests/gbproxy/gbproxy_test.c
index 103b4bd62..3986325a7 100644
--- a/openbsc/tests/gbproxy/gbproxy_test.c
+++ b/openbsc/tests/gbproxy/gbproxy_test.c
@@ -721,6 +721,53 @@ static void send_bssgp_llc_discarded(struct gprs_ns_inst *nsi,
send_ns_unitdata(nsi, "LLC_DISCARDED", src_addr, 0, msg, sizeof(msg));
}
+static void send_bssgp_paging(struct gprs_ns_inst *nsi,
+ struct sockaddr_in *src_addr,
+ const uint8_t *imsi, size_t imsi_size,
+ struct gprs_ra_id *raid, uint32_t ptmsi)
+{
+ /* Base Station Subsystem GPRS Protocol, BSSGP SUSPEND */
+ unsigned char msg[100] = {
+ 0x06,
+ };
+
+ const unsigned char drx_ie[] = {0x0a, 0x82, 0x07, 0x04};
+ const unsigned char qos_ie[] = {0x18, 0x83, 0x00, 0x00, 0x00};
+
+ size_t bssgp_msg_size = 1;
+
+ if (imsi) {
+ OSMO_ASSERT(imsi_size <= 127);
+ msg[bssgp_msg_size] = BSSGP_IE_IMSI;
+ msg[bssgp_msg_size + 1] = 0x80 | imsi_size;
+ memcpy(msg + bssgp_msg_size + 2, imsi, imsi_size);
+ bssgp_msg_size += 2 + imsi_size;
+ }
+
+ memcpy(msg + bssgp_msg_size, drx_ie, sizeof(drx_ie));
+ bssgp_msg_size += sizeof(drx_ie);
+
+ if (raid) {
+ msg[bssgp_msg_size] = BSSGP_IE_ROUTEING_AREA;
+ msg[bssgp_msg_size+1] = 0x86;
+ gsm48_construct_ra(msg + bssgp_msg_size + 2, raid);
+ bssgp_msg_size += 8;
+ }
+
+ memcpy(msg + bssgp_msg_size, qos_ie, sizeof(qos_ie));
+ bssgp_msg_size += sizeof(qos_ie);
+
+ if (ptmsi != GSM_RESERVED_TMSI) {
+ const uint32_t ptmsi_be = htonl(ptmsi);
+ msg[bssgp_msg_size] = BSSGP_IE_TMSI;
+ msg[bssgp_msg_size+1] = 0x84;
+ memcpy(msg + bssgp_msg_size + 2, &ptmsi_be, 4);
+ bssgp_msg_size += 6;
+ }
+
+ send_ns_unitdata(nsi, "PAGING_PS", src_addr, 0, msg, bssgp_msg_size);
+}
+
static void send_bssgp_flow_control_bvc(struct gprs_ns_inst *nsi,
struct sockaddr_in *src_addr,
uint16_t bvci, uint8_t tag)
@@ -2127,6 +2174,7 @@ static void test_gbproxy_ptmsi_patching()
struct gbproxy_peer *peer;
unsigned bss_nu = 0;
unsigned sgsn_nu = 0;
+ int old_ctr;
OSMO_ASSERT(local_sgsn_tlli == gprs_tmsi2tlli(sgsn_ptmsi, TLLI_LOCAL));
OSMO_ASSERT(local_sgsn_tlli2 == gprs_tmsi2tlli(sgsn_ptmsi2, TLLI_LOCAL));
@@ -2366,6 +2414,15 @@ static void test_gbproxy_ptmsi_patching()
dump_peers(stdout, 0, 0, &gbcfg);
+ old_ctr = peer->ctrg->ctr[GBPROX_PEER_CTR_PTMSI_PATCHED_SGSN].current;
+
+ send_bssgp_paging(nsi, &sgsn_peer, imsi, sizeof(imsi), &rai_bss, sgsn_ptmsi3);
+
+ dump_peers(stdout, 0, 0, &gbcfg);
+
+ OSMO_ASSERT(old_ctr + 1 ==
+ peer->ctrg->ctr[GBPROX_PEER_CTR_PTMSI_PATCHED_SGSN].current);
+
/* Bad case: Invalid BVCI */
send_bssgp_llc_discarded(nsi, &bss_peer[0], 0xeee1,
local_bss_tlli3, 1, 12);
diff --git a/openbsc/tests/gbproxy/gbproxy_test.ok b/openbsc/tests/gbproxy/gbproxy_test.ok
index 9dbcb4588..c5bf0c853 100644
--- a/openbsc/tests/gbproxy/gbproxy_test.ok
+++ b/openbsc/tests/gbproxy/gbproxy_test.ok
@@ -2756,6 +2756,30 @@ Peers:
TLLI cache size : 1
TLLI-Cache: 1
TLLI ead4775a -> e0543210, IMSI 12131415161718, AGE 0
+PROCESSING PAGING_PS from 0x05060708:32000
+00 00 00 00 06 0d 88 11 12 13 14 15 16 17 18 0a 82 07 04 1b 86 11 22 33 40 50 60 18 83 00 00 00 20 84 e0 54 32 10
+
+CALLBACK, event 0, msg length 34, bvci 0x0000
+00 00 00 00 06 0d 88 11 12 13 14 15 16 17 18 0a 82 07 04 1b 86 11 22 33 40 50 60 18 83 00 00 00 20 84 e0 54 32 10
+
+NS UNITDATA MESSAGE to BSS, BVCI 0x0000, msg length 34 (gprs_ns_sendmsg)
+MESSAGE to BSS at 0x01020304:1111, msg length 38
+00 00 00 00 06 0d 88 11 12 13 14 15 16 17 18 0a 82 07 04 1b 86 11 22 33 40 50 60 18 83 00 00 00 20 84 ea d4 77 5a
+
+result (PAGING_PS) = 38
+
+Peers:
+ NSEI 4096, BVCI 4098, not blocked, RAI 112-332-16464-96
+ RAID patched (BSS ): 13
+ RAID patched (SGSN): 5
+ APN patched : 1
+ TLLI patched (BSS ): 11
+ TLLI patched (SGSN): 9
+ P-TMSI patched (SGSN): 4
+ Attach Request count : 1
+ TLLI cache size : 1
+ TLLI-Cache: 1
+ TLLI ead4775a -> e0543210, IMSI 12131415161718, AGE 0
PROCESSING LLC_DISCARDED from 0x01020304:1111
00 00 00 00 2c 1f 84 ea d4 77 5a 0f 81 01 04 82 ee e1 25 83 00 00 0c
@@ -2838,12 +2862,12 @@ result (DETACH REQ) = 48
Peers:
NSEI 4096, BVCI 4098, not blocked, RAI 112-332-16464-96
RAID patched (BSS ): 14
- RAID patched (SGSN): 5
+ RAID patched (SGSN): 6
APN patched : 1
TLLI patched (BSS ): 13
TLLI patched (SGSN): 10
P-TMSI patched (BSS ): 1
- P-TMSI patched (SGSN): 3
+ P-TMSI patched (SGSN): 4
Attach Request count : 1
TLLI from SGSN unknown : 2
TLLI cache size : 1
@@ -2864,12 +2888,12 @@ result (DETACH ACC) = 71
Peers:
NSEI 4096, BVCI 4098, not blocked, RAI 112-332-16464-96
RAID patched (BSS ): 14
- RAID patched (SGSN): 5
+ RAID patched (SGSN): 6
APN patched : 1
TLLI patched (BSS ): 13
TLLI patched (SGSN): 11
P-TMSI patched (BSS ): 1
- P-TMSI patched (SGSN): 3
+ P-TMSI patched (SGSN): 4
Attach Request count : 1
TLLI from SGSN unknown : 2
TLLI-Cache: 0