gbproxy: Add VTY parameter: link stored-msgs-max-length
It was discovered in some prod setups that some TLLIs can maintain quite
long queues of msgb in case its IMSI is not acquired and the tlli is not
pruned due to link-list max-{age,length} being set to 0. As a result,
the osmo-gpbroxy steadly increases the list size of maintained TLLIs, and
some TLLI was found without IMSI catching already 1211 msgb.
Let's allow setting a maxiumum length for the queue storing those msgb
in a per TLLI base. If the limit is reached, oldest msgb are removed
before adding a new one.
Depends: libosmocore Change-Id I33b501e89a8f29e4aa121696bcbb13d4b83db40f
Related: SYS#4297
Change-Id: I4473be8604f80302df03ffdd5a13280dc072f824
diff --git a/src/gprs/gb_proxy.c b/src/gprs/gb_proxy.c
index f834ed3..8bb6789 100644
--- a/src/gprs/gb_proxy.c
+++ b/src/gprs/gb_proxy.c
@@ -338,7 +338,8 @@
msgb_nsei(msg));
/* Patch and flush stored messages towards the SGSN */
- while ((stored_msg = msgb_dequeue(&link_info->stored_msgs))) {
+ while ((stored_msg = msgb_dequeue_count(&link_info->stored_msgs,
+ &link_info->stored_msgs_len))) {
struct gprs_gb_parse_context tmp_parse_ctx = {0};
tmp_parse_ctx.to_bss = 0;
tmp_parse_ctx.peer_nsei = msgb_nsei(stored_msg);
@@ -492,6 +493,24 @@
/* The message cannot be processed since the IMSI is still missing */
+ /* If queue is getting too large, drop oldest msgb before adding new one */
+ if (peer->cfg->stored_msgs_max_len > 0) {
+ int exceeded_max_len = link_info->stored_msgs_len
+ + 1 - peer->cfg->stored_msgs_max_len;
+
+ for (; exceeded_max_len > 0; exceeded_max_len--) {
+ struct msgb *msgb_drop;
+ msgb_drop = msgb_dequeue_count(&link_info->stored_msgs,
+ &link_info->stored_msgs_len);
+ LOGP(DLLC, LOGL_INFO,
+ "NSEI=%d(BSS) Dropping stored msgb from list "
+ "(!acq imsi, length %d, max_len exceeded)\n",
+ msgb_nsei(msgb_drop), link_info->stored_msgs_len);
+
+ msgb_free(msgb_drop);
+ }
+ }
+
/* Enqueue unpatched messages */
LOGP(DLLC, LOGL_INFO,
"NSEI=%d(BSS) IMSI acquisition in progress, "
@@ -500,7 +519,8 @@
parse_ctx->llc_msg_name ? parse_ctx->llc_msg_name : "BSSGP");
stored_msg = bssgp_msgb_copy(msg, "process_bssgp_ul");
- msgb_enqueue(&link_info->stored_msgs, stored_msg);
+ msgb_enqueue_count(&link_info->stored_msgs, stored_msg,
+ &link_info->stored_msgs_len);
if (!link_info->imsi_acq_pending) {
LOGP(DLLC, LOGL_INFO,