gbproxy: Reset TLLIs when the link_info is found by IMSI/P-TMSI
Currently when the MS does a re-attach without doing a proper detach
first, the gbproxy uses the old local TLLI if patching and the keep
mode are enabled. This leads to a failing attachment procedure when
TLLI patching is also enabled.
This patch changes gbproxy_update_link_state_ul to reset all TLLIs
within the link_info if the message contains an unknown TLLI and an
MI. This is generally the case with Attach Request messages.
The gbproxy_get_link_info_ul gets an additional tlli_is_valid
output parameter that is set, when a TLLI was present and found.
This flag is then used instead of checking tlli.current == 0 to
set TLLI/P-TMSI e.g. Attach Requests when a link_info was already
present for the P-TMSI/IMSI used in such a request.
Ticket: OW#1324
Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/gb_proxy_tlli.c b/openbsc/src/gprs/gb_proxy_tlli.c
index 54e41e9..0aa0632 100644
--- a/openbsc/src/gprs/gb_proxy_tlli.c
+++ b/openbsc/src/gprs/gb_proxy_tlli.c
@@ -466,18 +466,28 @@
}
}
-struct gbproxy_link_info *gbproxy_get_link_info_ul(
+static struct gbproxy_link_info *gbproxy_get_link_info_ul(
struct gbproxy_peer *peer,
+ int *tlli_is_valid,
struct gprs_gb_parse_context *parse_ctx)
{
struct gbproxy_link_info *link_info = NULL;
- if (parse_ctx->tlli_enc)
+ if (parse_ctx->tlli_enc) {
link_info = gbproxy_link_info_by_tlli(peer, parse_ctx->tlli);
- if (!link_info && parse_ctx->imsi)
+ if (link_info) {
+ *tlli_is_valid = 1;
+ return link_info;
+ }
+ }
+
+ *tlli_is_valid = 0;
+
+ if (!link_info && parse_ctx->imsi) {
link_info = gbproxy_link_info_by_imsi(
peer, parse_ctx->imsi, parse_ctx->imsi_len);
+ }
if (!link_info && parse_ctx->ptmsi_enc && !parse_ctx->old_raid_is_foreign) {
uint32_t bss_ptmsi;
@@ -485,8 +495,10 @@
link_info = gbproxy_link_info_by_ptmsi(peer, bss_ptmsi);
}
- if (link_info)
- link_info->is_deregistered = 0;
+ if (!link_info)
+ return NULL;
+
+ link_info->is_deregistered = 0;
return link_info;
}
@@ -497,11 +509,13 @@
struct gprs_gb_parse_context *parse_ctx)
{
struct gbproxy_link_info *link_info;
+ int tlli_is_valid;
- link_info = gbproxy_get_link_info_ul(peer, parse_ctx);
+ link_info = gbproxy_get_link_info_ul(peer, &tlli_is_valid, parse_ctx);
if (parse_ctx->tlli_enc && parse_ctx->llc) {
uint32_t sgsn_tlli;
+
if (!link_info) {
LOGP(DGPRS, LOGL_INFO, "Adding TLLI %08x to list\n",
parse_ctx->tlli);
@@ -513,12 +527,14 @@
parse_ctx->tlli);
link_info->sgsn_tlli.current = sgsn_tlli;
link_info->tlli.current = parse_ctx->tlli;
- } else if (!link_info->tlli.current) {
+ } else if (!tlli_is_valid) {
/* New TLLI (info found by IMSI or P-TMSI) */
link_info->tlli.current = parse_ctx->tlli;
+ link_info->tlli.assigned = 0;
link_info->sgsn_tlli.current =
gbproxy_make_sgsn_tlli(peer, link_info,
parse_ctx->tlli);
+ link_info->sgsn_tlli.assigned = 0;
gbproxy_touch_link_info(peer, link_info, now);
} else {
sgsn_tlli = gbproxy_map_tlli(parse_ctx->tlli, link_info, 0);