gbproxy: Create STATUS message with original PDU
Currently when patching is enabled and an error happens when
receiving a message from the SGSN, the patched message is sent back
with the PDU_IN_ERROR IE.
This patch modifies gbprox_rx_sig_from_sgsn() to copy the message
before it is patched, so that the original message can be used with
the STATUS message. gbprox_rx_ptp_from_sgsn() does all checks before
the message is patched, so copying is not necessary.
Since gbprox_rx_sig_from_sgsn() is not called for BSSGP UNITDATA
messages and the msgb is already been copied in the gbprox_relay2peer
function, the relative performance impact is expected to be low.
Note that the PDU IE of STATUS messages received from an MS and
forwarded to the SGSN will not be patched. STATUS messages from the
SGSN are only logged and not forwarded to the MS.
Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/gb_proxy.c b/openbsc/src/gprs/gb_proxy.c
index dfceabe..280c557 100644
--- a/openbsc/src/gprs/gb_proxy.c
+++ b/openbsc/src/gprs/gb_proxy.c
@@ -448,6 +448,8 @@
peer = gbproxy_peer_by_bvci(cfg, ns_bvci);
+ /* Send status messages before patching */
+
if (!peer) {
LOGP(DGPRS, LOGL_INFO, "Didn't find peer for "
"BVCI=%u for message from NSVC=%u/NSEI=%u (SGSN)\n",
@@ -466,6 +468,9 @@
return bssgp_tx_status(BSSGP_CAUSE_BVCI_BLOCKED, NULL, msg);
}
+ /* Optionally patch the message */
+ gbprox_process_bssgp_dl(cfg, msg, peer);
+
return gbprox_relay2peer(msg, peer, ns_bvci);
}
@@ -621,6 +626,7 @@
/* Receive an incoming BVC-RESET message from the SGSN */
static int rx_reset_from_sgsn(struct gbproxy_config *cfg,
+ struct msgb *orig_msg,
struct msgb *msg, struct tlv_parsed *tp,
uint32_t nsei, uint16_t ns_bvci)
{
@@ -631,7 +637,7 @@
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_PROTO_ERR_SGSN]);
return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE,
- NULL, msg);
+ NULL, orig_msg);
}
ptp_bvci = ntohs(tlvp_val16_unal(tp, BSSGP_IE_BVCI));
@@ -645,7 +651,7 @@
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_INV_BVCI]);
return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI,
- NULL, msg);
+ NULL, orig_msg);
}
return gbprox_relay2peer(msg, peer, ns_bvci);
}
@@ -662,15 +668,17 @@
/* Receive an incoming signalling message from the SGSN-side NS-VC */
static int gbprox_rx_sig_from_sgsn(struct gbproxy_config *cfg,
- struct msgb *msg, uint32_t nsei,
+ struct msgb *orig_msg, uint32_t nsei,
uint16_t ns_bvci)
{
- struct bssgp_normal_hdr *bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg);
+ struct bssgp_normal_hdr *bgph =
+ (struct bssgp_normal_hdr *) msgb_bssgph(orig_msg);
struct tlv_parsed tp;
uint8_t pdu_type = bgph->pdu_type;
- int data_len = msgb_bssgp_len(msg) - sizeof(*bgph);
+ int data_len;
struct gbproxy_peer *peer;
uint16_t bvci;
+ struct msgb *msg;
int rc = 0;
if (ns_bvci != 0 && ns_bvci != 1) {
@@ -686,14 +694,19 @@
pdu_type == BSSGP_PDUT_DL_UNITDATA) {
LOGP(DGPRS, LOGL_NOTICE, "NSEI=%u(SGSN) UNITDATA not allowed in "
"signalling\n", nsei);
- return bssgp_tx_status(BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
+ return bssgp_tx_status(BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, orig_msg);
}
+ msg = gprs_msgb_copy(orig_msg, "rx_sig_from_sgsn");
+ gbprox_process_bssgp_dl(cfg, msg, NULL);
+ /* Update message info */
+ bgph = (struct bssgp_normal_hdr *) msgb_bssgph(msg);
+ data_len = msgb_bssgp_len(orig_msg) - sizeof(*bgph);
rc = bssgp_tlv_parse(&tp, bgph->data, data_len);
switch (pdu_type) {
case BSSGP_PDUT_BVC_RESET:
- rc = rx_reset_from_sgsn(cfg, msg, &tp, nsei, ns_bvci);
+ rc = rx_reset_from_sgsn(cfg, msg, orig_msg, &tp, nsei, ns_bvci);
break;
case BSSGP_PDUT_FLUSH_LL:
case BSSGP_PDUT_BVC_RESET_ACK:
@@ -762,29 +775,33 @@
"NSEI=%u(SGSN) BSSGP INVOKE TRACE not supported\n",nsei);
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_NOT_SUPPORTED_SGSN]);
- rc = bssgp_tx_status(BSSGP_CAUSE_PDU_INCOMP_FEAT, NULL, msg);
+ rc = bssgp_tx_status(BSSGP_CAUSE_PDU_INCOMP_FEAT, NULL, orig_msg);
break;
default:
LOGP(DGPRS, LOGL_NOTICE, "BSSGP PDU type 0x%02x unknown\n",
pdu_type);
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_PROTO_ERR_SGSN]);
- rc = bssgp_tx_status(BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, msg);
+ rc = bssgp_tx_status(BSSGP_CAUSE_PROTO_ERR_UNSPEC, NULL, orig_msg);
break;
}
+ msgb_free(msg);
+
return rc;
err_mand_ie:
LOGP(DGPRS, LOGL_ERROR, "NSEI=%u(SGSN) missing mandatory IE\n",
nsei);
rate_ctr_inc(&cfg->ctrg->
ctr[GBPROX_GLOB_CTR_PROTO_ERR_SGSN]);
- return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, msg);
+ msgb_free(msg);
+ return bssgp_tx_status(BSSGP_CAUSE_MISSING_MAND_IE, NULL, orig_msg);
err_no_peer:
LOGP(DGPRS, LOGL_ERROR, "NSEI=%u(SGSN) cannot find peer based on RAI\n",
nsei);
rate_ctr_inc(&cfg->ctrg-> ctr[GBPROX_GLOB_CTR_INV_RAI]);
- return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI, NULL, msg);
+ msgb_free(msg);
+ return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI, NULL, orig_msg);
}
/* Main input function for Gb proxy */
@@ -794,9 +811,6 @@
int rc;
int remote_end_is_sgsn = nsei == cfg->nsip_sgsn_nsei;
- if (remote_end_is_sgsn)
- gbprox_process_bssgp_dl(cfg, msg, NULL);
-
/* Only BVCI=0 messages need special treatment */
if (ns_bvci == 0 || ns_bvci == 1) {
if (remote_end_is_sgsn)