gbproxy: Keep tlli_info after detach
Currently a tlli_info entry is deleted when the TLLI gets invalidated
by a Detach message.
This patch introduces the possibility to keep tlli_info entries in
the list. Those entries then have cleared TLLI fields, are marked as
de-registered, and can only be retrieved by a message containing an
IMSI or a P-TMSI.
The following VTY configuration commands are added to the gbproxy
node:
- tlli-list keep-mode never : Don't keep the entries (default)
- tlli-list keep-mode re-attach : Only keep them, when a Detach
message with re-attach required has been received
- tlli-list keep-mode identified : Only keep entries which are
associated with an IMSI
- tlli-list keep-mode always : Keep all entries
Note that at least one of max-length or max-age should be set when
this feature is used to limit the number of entries.
Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/gb_proxy_tlli.c b/openbsc/src/gprs/gb_proxy_tlli.c
index 78459b7..509e489 100644
--- a/openbsc/src/gprs/gb_proxy_tlli.c
+++ b/openbsc/src/gprs/gb_proxy_tlli.c
@@ -316,17 +316,28 @@
gbproxy_attach_tlli_info(peer, now, tlli_info);
}
-static void gbproxy_unregister_tlli(struct gbproxy_peer *peer, uint32_t tlli)
+static void gbproxy_unregister_tlli(struct gbproxy_peer *peer,
+ struct gbproxy_tlli_info *tlli_info)
{
- struct gbproxy_tlli_info *tlli_info;
+ if (!tlli_info)
+ return;
- tlli_info = gbproxy_find_tlli(peer, tlli);
- if (tlli_info) {
+ if (tlli_info->tlli.ptmsi == GSM_RESERVED_TMSI && !tlli_info->imsi_len) {
LOGP(DGPRS, LOGL_INFO,
- "Removing TLLI %08x from list\n",
- tlli);
+ "Removing TLLI %08x from list (P-TMSI or IMSI are not set)\n",
+ tlli_info->tlli.current);
gbproxy_delete_tlli(peer, tlli_info);
+ return;
}
+
+ tlli_info->tlli.current = 0;
+ tlli_info->tlli.assigned = 0;
+ tlli_info->sgsn_tlli.current = 0;
+ tlli_info->sgsn_tlli.assigned = 0;
+
+ tlli_info->is_deregistered = 1;
+
+ return;
}
int gbproxy_check_tlli(struct gbproxy_peer *peer,
@@ -338,20 +349,44 @@
return tlli_info != NULL && tlli_info->enable_patching;
}
+struct gbproxy_tlli_info *gbproxy_get_tlli_info_ul(
+ struct gbproxy_peer *peer,
+ struct gprs_gb_parse_context *parse_ctx)
+{
+ struct gbproxy_tlli_info *tlli_info = NULL;
+
+ if (parse_ctx->tlli_enc)
+ tlli_info = gbproxy_find_tlli(peer, parse_ctx->tlli);
+
+ if (!tlli_info && parse_ctx->imsi)
+ tlli_info = gbproxy_find_tlli_by_imsi(
+ peer, parse_ctx->imsi, parse_ctx->imsi_len);
+
+ if (!tlli_info && parse_ctx->ptmsi_enc && !parse_ctx->old_raid_is_foreign) {
+ uint32_t bss_ptmsi;
+ if (!gprs_parse_mi_tmsi(parse_ctx->ptmsi_enc, GSM48_TMSI_LEN,
+ &bss_ptmsi))
+ LOGP(DGPRS, LOGL_ERROR,
+ "Failed to parse P-TMSI (TLLI is %08x)\n",
+ parse_ctx->tlli);
+ else
+ tlli_info = gbproxy_find_tlli_by_ptmsi(peer, bss_ptmsi);
+ }
+
+ if (tlli_info)
+ tlli_info->is_deregistered = 0;
+
+ return tlli_info;
+}
+
struct gbproxy_tlli_info *gbproxy_update_tlli_state_ul(
struct gbproxy_peer *peer,
time_t now,
struct gprs_gb_parse_context *parse_ctx)
{
- struct gbproxy_tlli_info *tlli_info = NULL;
+ struct gbproxy_tlli_info *tlli_info;
- if (parse_ctx->tlli_enc) {
- tlli_info = gbproxy_find_tlli(peer, parse_ctx->tlli);
-
- if (!tlli_info && parse_ctx->imsi)
- tlli_info = gbproxy_find_tlli_by_imsi(
- peer, parse_ctx->imsi, parse_ctx->imsi_len);
- }
+ tlli_info = gbproxy_get_tlli_info_ul(peer, parse_ctx);
if (parse_ctx->tlli_enc && parse_ctx->llc) {
uint32_t sgsn_tlli;
@@ -366,6 +401,13 @@
parse_ctx->tlli);
tlli_info->sgsn_tlli.current = sgsn_tlli;
tlli_info->tlli.current = parse_ctx->tlli;;
+ } else if (!tlli_info->tlli.current) {
+ /* New TLLI (info found by IMSI or P-TMSI) */
+ tlli_info->tlli.current = parse_ctx->tlli;
+ tlli_info->sgsn_tlli.current =
+ gbproxy_make_sgsn_tlli(peer, tlli_info,
+ parse_ctx->tlli);
+ gbproxy_touch_tlli(peer, tlli_info, now);
} else {
sgsn_tlli = gbproxy_map_tlli(parse_ctx->tlli, tlli_info, 0);
if (!sgsn_tlli)
@@ -512,8 +554,22 @@
time_t now,
struct gprs_gb_parse_context *parse_ctx)
{
- if (parse_ctx->invalidate_tlli) {
- gbproxy_unregister_tlli(peer, parse_ctx->tlli);
+ if (parse_ctx->invalidate_tlli && tlli_info) {
+ int keep_info =
+ peer->cfg->keep_tlli_infos == GBPROX_KEEP_ALWAYS ||
+ (peer->cfg->keep_tlli_infos == GBPROX_KEEP_REATTACH &&
+ parse_ctx->await_reattach) ||
+ (peer->cfg->keep_tlli_infos == GBPROX_KEEP_IDENTIFIED &&
+ tlli_info->imsi_len > 0);
+ if (keep_info) {
+ LOGP(DGPRS, LOGL_INFO, "Unregistering TLLI %08x\n",
+ tlli_info->tlli.current);
+ gbproxy_unregister_tlli(peer, tlli_info);
+ } else {
+ LOGP(DGPRS, LOGL_INFO, "Removing TLLI %08x from list\n",
+ tlli_info->tlli.current);
+ gbproxy_delete_tlli(peer, tlli_info);
+ }
} else if (parse_ctx->to_bss && parse_ctx->tlli_enc &&
parse_ctx->new_ptmsi_enc && tlli_info) {
/* A new PTMSI has been signaled in the message,