gbproxy: Separate SGSN numeric namespaces
Currently the SGSN side message's TLLI are searched without checking
the originating SGSN. This leads to collisions if both SGSN use the
same P-TMSI for different MS.
With this patch, the SGSN NSEI is stored within the tlli_info and is
used in comparisons to separate the namespaces.
Note that this type of collision cannot happen with BSS numbers,
since the tlli_info are already separated and stored per (BSS) peer.
Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/gb_proxy.c b/openbsc/src/gprs/gb_proxy.c
index ee80375..4b46b0e 100644
--- a/openbsc/src/gprs/gb_proxy.c
+++ b/openbsc/src/gprs/gb_proxy.c
@@ -257,7 +257,7 @@
sgsn_tlli = rand_r(&peer->cfg->sgsn_tlli_state);
sgsn_tlli = (sgsn_tlli & 0x7fffffff) | 0x78000000;
- if (gbproxy_find_tlli_by_sgsn_tlli(peer, sgsn_tlli))
+ if (gbproxy_find_tlli_by_any_sgsn_tlli(peer, sgsn_tlli))
sgsn_tlli = 0;
} while (!sgsn_tlli);
}
@@ -309,6 +309,7 @@
while ((stored_msg = msgb_dequeue(&tlli_info->stored_msgs))) {
struct gprs_gb_parse_context tmp_parse_ctx = {0};
tmp_parse_ctx.to_bss = 0;
+ tmp_parse_ctx.peer_nsei = msgb_nsei(stored_msg);
int len_change = 0;
gprs_gb_parse_bssgp(msgb_bssgph(stored_msg),
@@ -511,13 +512,13 @@
time_t now;
struct gbproxy_tlli_info *tlli_info = NULL;
uint32_t sgsn_nsei = cfg->nsip_sgsn_nsei;
- int send_msg_directly = 0;
if (!cfg->core_mcc && !cfg->core_mnc && !cfg->core_apn &&
!cfg->acquire_imsi && !cfg->patch_ptmsi && !cfg->route_to_sgsn2)
return 1;
parse_ctx.to_bss = 0;
+ parse_ctx.peer_nsei = msgb_nsei(msg);
/* Parse BSSGP/LLC */
rc = gprs_gb_parse_bssgp(msgb_bssgph(msg), msgb_bssgp_len(msg),
@@ -560,11 +561,16 @@
}
}
- if (tlli_info && cfg->route_to_sgsn2 && gbproxy_check_tlli(peer, tlli_info)) {
- sgsn_nsei = cfg->nsip_sgsn2_nsei;
- send_msg_directly = 1;
+ if (tlli_info && cfg->route_to_sgsn2) {
+ if (cfg->acquire_imsi && tlli_info->imsi_len == 0)
+ sgsn_nsei = 0xffff;
+ else if (gbproxy_check_tlli(peer, tlli_info))
+ sgsn_nsei = cfg->nsip_sgsn2_nsei;
}
+ if (tlli_info)
+ tlli_info->sgsn_nsei = sgsn_nsei;
+
/* Handle IMSI acquisition */
if (cfg->acquire_imsi) {
rc = gbproxy_imsi_acquisition(peer, msg, sgsn_nsei, now,
@@ -578,7 +584,7 @@
gbproxy_update_tlli_state_after(peer, tlli_info, now, &parse_ctx);
- if (send_msg_directly) {
+ if (sgsn_nsei != cfg->nsip_sgsn_nsei) {
/* Send message directly to the selected SGSN */
rc = gbprox_relay2sgsn(cfg, msg, msgb_bvci(msg), sgsn_nsei);
/* Don't let the calling code handle the transmission */
@@ -604,6 +610,7 @@
return;
parse_ctx.to_bss = 1;
+ parse_ctx.peer_nsei = msgb_nsei(msg);
rc = gprs_gb_parse_bssgp(msgb_bssgph(msg), msgb_bssgp_len(msg),
&parse_ctx);