gbproxy: Support a secondary SGSN
This patch refactors SGSN NSEI handling to support a secondary SGSN.
It adds the following VTY commands:
- secondary-sgsn nsei <0-65534>
- no secondary-sgsn
Sending messages to the secondary SGSN is not yet implemented, but
received messages from such a SGSN would be forwarded to the BSS
peers.
Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/gprs/gb_proxy.c b/openbsc/src/gprs/gb_proxy.c
index f0375ee..539e3ae 100644
--- a/openbsc/src/gprs/gb_proxy.c
+++ b/openbsc/src/gprs/gb_proxy.c
@@ -75,7 +75,7 @@
static int gbprox_relay2peer(struct msgb *old_msg, struct gbproxy_peer *peer,
uint16_t ns_bvci);
static int gbprox_relay2sgsn(struct gbproxy_config *cfg, struct msgb *old_msg,
- uint16_t ns_bvci);
+ uint16_t ns_bvci, uint16_t sgsn_nsei);
static int check_peer_nsei(struct gbproxy_peer *peer, uint16_t nsei)
{
@@ -358,7 +358,8 @@
gbproxy_update_tlli_state_after(peer, tlli_info, now,
&tmp_parse_ctx);
- rc = gbprox_relay2sgsn(cfg, stored_msg, msgb_bvci(msg));
+ rc = gbprox_relay2sgsn(cfg, stored_msg, msgb_bvci(msg),
+ cfg->nsip_sgsn_nsei);
if (rc < 0)
LOGP(DLLC, LOGL_ERROR,
@@ -496,7 +497,7 @@
/* feed a message down the NS-VC associated with the specified peer */
static int gbprox_relay2sgsn(struct gbproxy_config *cfg, struct msgb *old_msg,
- uint16_t ns_bvci)
+ uint16_t ns_bvci, uint16_t sgsn_nsei)
{
/* create a copy of the message so the old one can
* be free()d safely when we return from gbprox_rcvmsg() */
@@ -504,10 +505,10 @@
int rc;
DEBUGP(DGPRS, "NSEI=%u proxying BTS->SGSN (NS_BVCI=%u, NSEI=%u)\n",
- msgb_nsei(msg), ns_bvci, cfg->nsip_sgsn_nsei);
+ msgb_nsei(msg), ns_bvci, sgsn_nsei);
msgb_bvci(msg) = ns_bvci;
- msgb_nsei(msg) = cfg->nsip_sgsn_nsei;
+ msgb_nsei(msg) = sgsn_nsei;
strip_ns_hdr(msg);
@@ -610,7 +611,7 @@
if (!rc)
return 0;
- return gbprox_relay2sgsn(cfg, msg, ns_bvci);
+ return gbprox_relay2sgsn(cfg, msg, ns_bvci, cfg->nsip_sgsn_nsei);
}
/* Receive an incoming PTP message from a SGSN-side NS-VC */
@@ -752,7 +753,7 @@
rc = gbprox_process_bssgp_ul(cfg, msg, from_peer);
if (!rc)
return 0;
- return gbprox_relay2sgsn(cfg, msg, ns_bvci);
+ return gbprox_relay2sgsn(cfg, msg, ns_bvci, cfg->nsip_sgsn_nsei);
err_no_peer:
LOGP(DGPRS, LOGL_ERROR, "NSEI=%u(BSS) cannot find peer based on NSEI\n",
nsei);
@@ -981,12 +982,18 @@
return bssgp_tx_status(BSSGP_CAUSE_UNKNOWN_BVCI, NULL, orig_msg);
}
+static int gbproxy_is_sgsn_nsei(struct gbproxy_config *cfg, uint16_t nsei)
+{
+ return nsei == cfg->nsip_sgsn_nsei ||
+ (cfg->route_to_sgsn2 && nsei == cfg->nsip_sgsn2_nsei);
+}
+
/* Main input function for Gb proxy */
int gbprox_rcvmsg(struct gbproxy_config *cfg, struct msgb *msg, uint16_t nsei,
uint16_t ns_bvci, uint16_t nsvci)
{
int rc;
- int remote_end_is_sgsn = nsei == cfg->nsip_sgsn_nsei;
+ int remote_end_is_sgsn = gbproxy_is_sgsn_nsei(cfg, nsei);
/* Only BVCI=0 messages need special treatment */
if (ns_bvci == 0 || ns_bvci == 1) {
@@ -1027,11 +1034,12 @@
struct ns_signal_data *nssd = signal_data;
struct gprs_nsvc *nsvc = nssd->nsvc;
struct gbproxy_peer *peer;
+ int remote_end_is_sgsn = gbproxy_is_sgsn_nsei(cfg, nsvc->nsei);
if (subsys != SS_L_NS)
return 0;
- if (signal == S_NS_RESET && nsvc->nsei == cfg->nsip_sgsn_nsei) {
+ if (signal == S_NS_RESET && remote_end_is_sgsn) {
/* We have received a NS-RESET from the NSEI and NSVC
* of the SGSN. This might happen with SGSN that start
* their own NS-RESET procedure without waiting for our
diff --git a/openbsc/src/gprs/gb_proxy_vty.c b/openbsc/src/gprs/gb_proxy_vty.c
index 49c0020..cd16f38 100644
--- a/openbsc/src/gprs/gb_proxy_vty.c
+++ b/openbsc/src/gprs/gb_proxy_vty.c
@@ -317,6 +317,32 @@
return CMD_SUCCESS;
}
+#define GBPROXY_SECOND_SGSN_STR "Route matching LLC connections to a second SGSN (Experimental)\n"
+
+DEFUN(cfg_gbproxy_secondary_sgsn,
+ cfg_gbproxy_secondary_sgsn_cmd,
+ "secondary-sgsn nsei <0-65534>",
+ GBPROXY_SECOND_SGSN_STR
+ "NSEI to be used in the connection with the SGSN\n"
+ "The NSEI\n")
+{
+ g_cfg->route_to_sgsn2 = 1;
+ g_cfg->nsip_sgsn2_nsei = atoi(argv[0]);
+
+ return CMD_SUCCESS;
+}
+
+DEFUN(cfg_gbproxy_no_secondary_sgsn,
+ cfg_gbproxy_no_secondary_sgsn_cmd,
+ "no secondary-sgsn",
+ NO_STR GBPROXY_SECOND_SGSN_STR)
+{
+ g_cfg->route_to_sgsn2 = 0;
+ g_cfg->nsip_sgsn2_nsei = 0xFFFF;
+
+ return CMD_SUCCESS;
+}
+
#define GBPROXY_TLLI_LIST_STR "Set TLLI list parameters\n"
#define GBPROXY_MAX_AGE_STR "Limit maximum age\n"
@@ -627,6 +653,7 @@
install_element(GBPROXY_NODE, &cfg_gbproxy_core_apn_match_cmd);
install_element(GBPROXY_NODE, &cfg_gbproxy_patch_ptmsi_cmd);
install_element(GBPROXY_NODE, &cfg_gbproxy_acquire_imsi_cmd);
+ install_element(GBPROXY_NODE, &cfg_gbproxy_secondary_sgsn_cmd);
install_element(GBPROXY_NODE, &cfg_gbproxy_tlli_list_max_age_cmd);
install_element(GBPROXY_NODE, &cfg_gbproxy_tlli_list_max_len_cmd);
install_element(GBPROXY_NODE, &cfg_gbproxy_no_core_mcc_cmd);
@@ -634,6 +661,7 @@
install_element(GBPROXY_NODE, &cfg_gbproxy_no_core_apn_cmd);
install_element(GBPROXY_NODE, &cfg_gbproxy_no_patch_ptmsi_cmd);
install_element(GBPROXY_NODE, &cfg_gbproxy_no_acquire_imsi_cmd);
+ install_element(GBPROXY_NODE, &cfg_gbproxy_no_secondary_sgsn_cmd);
install_element(GBPROXY_NODE, &cfg_gbproxy_tlli_list_no_max_age_cmd);
install_element(GBPROXY_NODE, &cfg_gbproxy_tlli_list_no_max_len_cmd);
install_element(GBPROXY_NODE, &cfg_gbproxy_patch_mode_cmd);