aboutsummaryrefslogtreecommitdiffstats
path: root/src/libgb/gprs_ns.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/libgb/gprs_ns.c')
-rw-r--r--src/libgb/gprs_ns.c992
1 files changed, 992 insertions, 0 deletions
diff --git a/src/libgb/gprs_ns.c b/src/libgb/gprs_ns.c
new file mode 100644
index 00000000..5a8e3586
--- /dev/null
+++ b/src/libgb/gprs_ns.c
@@ -0,0 +1,992 @@
+/* GPRS Networks Service (NS) messages on the Gb interfacebvci = msgb_bvci(msg);
+ * 3GPP TS 08.16 version 8.0.1 Release 1999 / ETSI TS 101 299 V8.0.1 (2002-05) */
+
+/* (C) 2009-2010 by Harald Welte <laforge@gnumonks.org>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/* Some introduction into NS: NS is used typically on top of frame relay,
+ * but in the ip.access world it is encapsulated in UDP packets. It serves
+ * as an intermediate shim betwen BSSGP and the underlying medium. It doesn't
+ * do much, apart from providing congestion notification and status indication.
+ *
+ * Terms:
+ * NS Network Service
+ * NSVC NS Virtual Connection
+ * NSEI NS Entity Identifier
+ * NSVL NS Virtual Link
+ * NSVLI NS Virtual Link Identifier
+ * BVC BSSGP Virtual Connection
+ * BVCI BSSGP Virtual Connection Identifier
+ * NSVCG NS Virtual Connection Goup
+ * Blocked NS-VC cannot be used for user traffic
+ * Alive Ability of a NS-VC to provide communication
+ *
+ * There can be multiple BSSGP virtual connections over one (group of) NSVC's. BSSGP will
+ * therefore identify the BSSGP virtual connection by a BVCI passed down to NS.
+ * NS then has to firgure out which NSVC's are responsible for this BVCI.
+ * Those mappings are administratively configured.
+ */
+
+/* This implementation has the following limitations:
+ * o Only one NS-VC for each NSE: No load-sharing function
+ * o NSVCI 65535 and 65534 are reserved for internal use
+ * o Only UDP is supported as of now, no frame relay support
+ * o The IP Sub-Network-Service (SNS) as specified in 48.016 is not implemented
+ * o There are no BLOCK and UNBLOCK timers (yet?)
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdint.h>
+
+#include <arpa/inet.h>
+
+#include <openbsc/gsm_data.h>
+#include <osmocore/msgb.h>
+#include <osmocore/tlv.h>
+#include <osmocore/talloc.h>
+#include <osmocore/select.h>
+#include <osmocore/rate_ctr.h>
+#include <openbsc/debug.h>
+#include <openbsc/signal.h>
+#include <openbsc/gprs_ns.h>
+#include <openbsc/gprs_bssgp.h>
+#include <openbsc/gprs_ns_frgre.h>
+#include <openbsc/socket.h>
+
+static const struct tlv_definition ns_att_tlvdef = {
+ .def = {
+ [NS_IE_CAUSE] = { TLV_TYPE_TvLV, 0 },
+ [NS_IE_VCI] = { TLV_TYPE_TvLV, 0 },
+ [NS_IE_PDU] = { TLV_TYPE_TvLV, 0 },
+ [NS_IE_BVCI] = { TLV_TYPE_TvLV, 0 },
+ [NS_IE_NSEI] = { TLV_TYPE_TvLV, 0 },
+ },
+};
+
+enum ns_ctr {
+ NS_CTR_PKTS_IN,
+ NS_CTR_PKTS_OUT,
+ NS_CTR_BYTES_IN,
+ NS_CTR_BYTES_OUT,
+ NS_CTR_BLOCKED,
+ NS_CTR_DEAD,
+};
+
+static const struct rate_ctr_desc nsvc_ctr_description[] = {
+ { "packets.in", "Packets at NS Level ( In)" },
+ { "packets.out","Packets at NS Level (Out)" },
+ { "bytes.in", "Bytes at NS Level ( In)" },
+ { "bytes.out", "Bytes at NS Level (Out)" },
+ { "blocked", "NS-VC Block count " },
+ { "dead", "NS-VC gone dead count " },
+};
+
+static const struct rate_ctr_group_desc nsvc_ctrg_desc = {
+ .group_name_prefix = "ns.nsvc",
+ .group_description = "NSVC Peer Statistics",
+ .num_ctr = ARRAY_SIZE(nsvc_ctr_description),
+ .ctr_desc = nsvc_ctr_description,
+};
+
+/* Lookup struct gprs_nsvc based on NSVCI */
+struct gprs_nsvc *nsvc_by_nsvci(struct gprs_ns_inst *nsi, uint16_t nsvci)
+{
+ struct gprs_nsvc *nsvc;
+ llist_for_each_entry(nsvc, &nsi->gprs_nsvcs, list) {
+ if (nsvc->nsvci == nsvci)
+ return nsvc;
+ }
+ return NULL;
+}
+
+/* Lookup struct gprs_nsvc based on NSVCI */
+struct gprs_nsvc *nsvc_by_nsei(struct gprs_ns_inst *nsi, uint16_t nsei)
+{
+ struct gprs_nsvc *nsvc;
+ llist_for_each_entry(nsvc, &nsi->gprs_nsvcs, list) {
+ if (nsvc->nsei == nsei)
+ return nsvc;
+ }
+ return NULL;
+}
+
+/* Lookup struct gprs_nsvc based on remote peer socket addr */
+static struct gprs_nsvc *nsvc_by_rem_addr(struct gprs_ns_inst *nsi,
+ struct sockaddr_in *sin)
+{
+ struct gprs_nsvc *nsvc;
+ llist_for_each_entry(nsvc, &nsi->gprs_nsvcs, list) {
+ if (nsvc->ip.bts_addr.sin_addr.s_addr ==
+ sin->sin_addr.s_addr &&
+ nsvc->ip.bts_addr.sin_port == sin->sin_port)
+ return nsvc;
+ }
+ return NULL;
+}
+
+static void gprs_ns_timer_cb(void *data);
+
+struct gprs_nsvc *nsvc_create(struct gprs_ns_inst *nsi, uint16_t nsvci)
+{
+ struct gprs_nsvc *nsvc;
+
+ LOGP(DNS, LOGL_INFO, "NSVCI=%u Creating NS-VC\n", nsvci);
+
+ nsvc = talloc_zero(nsi, struct gprs_nsvc);
+ nsvc->nsvci = nsvci;
+ /* before RESET procedure: BLOCKED and DEAD */
+ nsvc->state = NSE_S_BLOCKED;
+ nsvc->nsi = nsi;
+ nsvc->timer.cb = gprs_ns_timer_cb;
+ nsvc->timer.data = nsvc;
+ nsvc->ctrg = rate_ctr_group_alloc(nsvc, &nsvc_ctrg_desc, nsvci);
+
+ llist_add(&nsvc->list, &nsi->gprs_nsvcs);
+
+ return nsvc;
+}
+
+void nsvc_delete(struct gprs_nsvc *nsvc)
+{
+ if (bsc_timer_pending(&nsvc->timer))
+ bsc_del_timer(&nsvc->timer);
+ llist_del(&nsvc->list);
+ talloc_free(nsvc);
+}
+
+static void ns_dispatch_signal(struct gprs_nsvc *nsvc, unsigned int signal,
+ uint8_t cause)
+{
+ struct ns_signal_data nssd;
+
+ nssd.nsvc = nsvc;
+ nssd.cause = cause;
+
+ dispatch_signal(SS_NS, signal, &nssd);
+}
+
+/* Section 10.3.2, Table 13 */
+static const struct value_string ns_cause_str[] = {
+ { NS_CAUSE_TRANSIT_FAIL, "Transit network failure" },
+ { NS_CAUSE_OM_INTERVENTION, "O&M intervention" },
+ { NS_CAUSE_EQUIP_FAIL, "Equipment failure" },
+ { NS_CAUSE_NSVC_BLOCKED, "NS-VC blocked" },
+ { NS_CAUSE_NSVC_UNKNOWN, "NS-VC unknown" },
+ { NS_CAUSE_BVCI_UNKNOWN, "BVCI unknown" },
+ { NS_CAUSE_SEM_INCORR_PDU, "Semantically incorrect PDU" },
+ { NS_CAUSE_PDU_INCOMP_PSTATE, "PDU not compatible with protocol state" },
+ { NS_CAUSE_PROTO_ERR_UNSPEC, "Protocol error, unspecified" },
+ { NS_CAUSE_INVAL_ESSENT_IE, "Invalid essential IE" },
+ { NS_CAUSE_MISSING_ESSENT_IE, "Missing essential IE" },
+ { 0, NULL }
+};
+
+const char *gprs_ns_cause_str(enum ns_cause cause)
+{
+ return get_value_string(ns_cause_str, cause);
+}
+
+static int nsip_sendmsg(struct gprs_nsvc *nsvc, struct msgb *msg);
+extern int grps_ns_frgre_sendmsg(struct gprs_nsvc *nsvc, struct msgb *msg);
+
+static int gprs_ns_tx(struct gprs_nsvc *nsvc, struct msgb *msg)
+{
+ int ret;
+
+ log_set_context(BSC_CTX_NSVC, nsvc);
+
+ /* Increment number of Uplink bytes */
+ rate_ctr_inc(&nsvc->ctrg->ctr[NS_CTR_PKTS_OUT]);
+ rate_ctr_add(&nsvc->ctrg->ctr[NS_CTR_BYTES_OUT], msgb_l2len(msg));
+
+ switch (nsvc->ll) {
+ case GPRS_NS_LL_UDP:
+ ret = nsip_sendmsg(nsvc, msg);
+ break;
+ case GPRS_NS_LL_FR_GRE:
+ ret = gprs_ns_frgre_sendmsg(nsvc, msg);
+ break;
+ default:
+ LOGP(DNS, LOGL_ERROR, "unsupported NS linklayer %u\n", nsvc->ll);
+ msgb_free(msg);
+ ret = -EIO;
+ break;
+ }
+ return ret;
+}
+
+static int gprs_ns_tx_simple(struct gprs_nsvc *nsvc, uint8_t pdu_type)
+{
+ struct msgb *msg = gprs_ns_msgb_alloc();
+ struct gprs_ns_hdr *nsh;
+
+ log_set_context(BSC_CTX_NSVC, nsvc);
+
+ if (!msg)
+ return -ENOMEM;
+
+ msg->l2h = msgb_put(msg, sizeof(*nsh));
+ nsh = (struct gprs_ns_hdr *) msg->l2h;
+
+ nsh->pdu_type = pdu_type;
+
+ return gprs_ns_tx(nsvc, msg);
+}
+
+int gprs_ns_tx_reset(struct gprs_nsvc *nsvc, uint8_t cause)
+{
+ struct msgb *msg = gprs_ns_msgb_alloc();
+ struct gprs_ns_hdr *nsh;
+ uint16_t nsvci = htons(nsvc->nsvci);
+ uint16_t nsei = htons(nsvc->nsei);
+
+ log_set_context(BSC_CTX_NSVC, nsvc);
+
+ if (!msg)
+ return -ENOMEM;
+
+ LOGP(DNS, LOGL_INFO, "NSEI=%u Tx NS RESET (NSVCI=%u, cause=%s)\n",
+ nsvc->nsei, nsvc->nsvci, gprs_ns_cause_str(cause));
+
+ msg->l2h = msgb_put(msg, sizeof(*nsh));
+ nsh = (struct gprs_ns_hdr *) msg->l2h;
+ nsh->pdu_type = NS_PDUT_RESET;
+
+ msgb_tvlv_put(msg, NS_IE_CAUSE, 1, &cause);
+ msgb_tvlv_put(msg, NS_IE_VCI, 2, (uint8_t *) &nsvci);
+ msgb_tvlv_put(msg, NS_IE_NSEI, 2, (uint8_t *) &nsei);
+
+ return gprs_ns_tx(nsvc, msg);
+
+}
+
+int gprs_ns_tx_status(struct gprs_nsvc *nsvc, uint8_t cause,
+ uint16_t bvci, struct msgb *orig_msg)
+{
+ struct msgb *msg = gprs_ns_msgb_alloc();
+ struct gprs_ns_hdr *nsh;
+ uint16_t nsvci = htons(nsvc->nsvci);
+
+ log_set_context(BSC_CTX_NSVC, nsvc);
+
+ bvci = htons(bvci);
+
+ if (!msg)
+ return -ENOMEM;
+
+ LOGP(DNS, LOGL_NOTICE, "NSEI=%u Tx NS STATUS (NSVCI=%u, cause=%s)\n",
+ nsvc->nsei, nsvc->nsvci, gprs_ns_cause_str(cause));
+
+ msg->l2h = msgb_put(msg, sizeof(*nsh));
+ nsh = (struct gprs_ns_hdr *) msg->l2h;
+ nsh->pdu_type = NS_PDUT_STATUS;
+
+ msgb_tvlv_put(msg, NS_IE_CAUSE, 1, &cause);
+
+ /* Section 9.2.7.1: Static conditions for NS-VCI */
+ if (cause == NS_CAUSE_NSVC_BLOCKED ||
+ cause == NS_CAUSE_NSVC_UNKNOWN)
+ msgb_tvlv_put(msg, NS_IE_VCI, 2, (uint8_t *)&nsvci);
+
+ /* Section 9.2.7.2: Static conditions for NS PDU */
+ switch (cause) {
+ case NS_CAUSE_SEM_INCORR_PDU:
+ case NS_CAUSE_PDU_INCOMP_PSTATE:
+ case NS_CAUSE_PROTO_ERR_UNSPEC:
+ case NS_CAUSE_INVAL_ESSENT_IE:
+ case NS_CAUSE_MISSING_ESSENT_IE:
+ msgb_tvlv_put(msg, NS_IE_PDU, msgb_l2len(orig_msg),
+ orig_msg->l2h);
+ break;
+ default:
+ break;
+ }
+
+ /* Section 9.2.7.3: Static conditions for BVCI */
+ if (cause == NS_CAUSE_BVCI_UNKNOWN)
+ msgb_tvlv_put(msg, NS_IE_VCI, 2, (uint8_t *)&bvci);
+
+ return gprs_ns_tx(nsvc, msg);
+}
+
+int gprs_ns_tx_block(struct gprs_nsvc *nsvc, uint8_t cause)
+{
+ struct msgb *msg = gprs_ns_msgb_alloc();
+ struct gprs_ns_hdr *nsh;
+ uint16_t nsvci = htons(nsvc->nsvci);
+
+ log_set_context(BSC_CTX_NSVC, nsvc);
+
+ if (!msg)
+ return -ENOMEM;
+
+ LOGP(DNS, LOGL_INFO, "NSEI=%u Tx NS BLOCK (NSVCI=%u, cause=%s)\n",
+ nsvc->nsei, nsvc->nsvci, gprs_ns_cause_str(cause));
+
+ /* be conservative and mark it as blocked even now! */
+ nsvc->state |= NSE_S_BLOCKED;
+ rate_ctr_inc(&nsvc->ctrg->ctr[NS_CTR_BLOCKED]);
+
+ msg->l2h = msgb_put(msg, sizeof(*nsh));
+ nsh = (struct gprs_ns_hdr *) msg->l2h;
+ nsh->pdu_type = NS_PDUT_BLOCK;
+
+ msgb_tvlv_put(msg, NS_IE_CAUSE, 1, &cause);
+ msgb_tvlv_put(msg, NS_IE_VCI, 2, (uint8_t *) &nsvci);
+
+ return gprs_ns_tx(nsvc, msg);
+}
+
+int gprs_ns_tx_unblock(struct gprs_nsvc *nsvc)
+{
+ log_set_context(BSC_CTX_NSVC, nsvc);
+ LOGP(DNS, LOGL_INFO, "NSEI=%u Tx NS UNBLOCK (NSVCI=%u)\n",
+ nsvc->nsei, nsvc->nsvci);
+
+ return gprs_ns_tx_simple(nsvc, NS_PDUT_UNBLOCK);
+}
+
+int gprs_ns_tx_alive(struct gprs_nsvc *nsvc)
+{
+ log_set_context(BSC_CTX_NSVC, nsvc);
+ LOGP(DNS, LOGL_DEBUG, "NSEI=%u Tx NS ALIVE (NSVCI=%u)\n",
+ nsvc->nsei, nsvc->nsvci);
+
+ return gprs_ns_tx_simple(nsvc, NS_PDUT_ALIVE);
+}
+
+int gprs_ns_tx_alive_ack(struct gprs_nsvc *nsvc)
+{
+ log_set_context(BSC_CTX_NSVC, nsvc);
+ LOGP(DNS, LOGL_DEBUG, "NSEI=%u Tx NS ALIVE_ACK (NSVCI=%u)\n",
+ nsvc->nsei, nsvc->nsvci);
+
+ return gprs_ns_tx_simple(nsvc, NS_PDUT_ALIVE_ACK);
+}
+
+static const enum ns_timeout timer_mode_tout[_NSVC_TIMER_NR] = {
+ [NSVC_TIMER_TNS_RESET] = NS_TOUT_TNS_RESET,
+ [NSVC_TIMER_TNS_ALIVE] = NS_TOUT_TNS_ALIVE,
+ [NSVC_TIMER_TNS_TEST] = NS_TOUT_TNS_TEST,
+};
+
+static const struct value_string timer_mode_strs[] = {
+ { NSVC_TIMER_TNS_RESET, "tns-reset" },
+ { NSVC_TIMER_TNS_ALIVE, "tns-alive" },
+ { NSVC_TIMER_TNS_TEST, "tns-test" },
+ { 0, NULL }
+};
+
+static void nsvc_start_timer(struct gprs_nsvc *nsvc, enum nsvc_timer_mode mode)
+{
+ enum ns_timeout tout = timer_mode_tout[mode];
+ unsigned int seconds = nsvc->nsi->timeout[tout];
+
+ log_set_context(BSC_CTX_NSVC, nsvc);
+ DEBUGP(DNS, "NSEI=%u Starting timer in mode %s (%u seconds)\n",
+ nsvc->nsei, get_value_string(timer_mode_strs, mode),
+ seconds);
+
+ if (bsc_timer_pending(&nsvc->timer))
+ bsc_del_timer(&nsvc->timer);
+
+ nsvc->timer_mode = mode;
+ bsc_schedule_timer(&nsvc->timer, seconds, 0);
+}
+
+static void gprs_ns_timer_cb(void *data)
+{
+ struct gprs_nsvc *nsvc = data;
+ enum ns_timeout tout = timer_mode_tout[nsvc->timer_mode];
+ unsigned int seconds = nsvc->nsi->timeout[tout];
+
+ log_set_context(BSC_CTX_NSVC, nsvc);
+ DEBUGP(DNS, "NSEI=%u Timer expired in mode %s (%u seconds)\n",
+ nsvc->nsei, get_value_string(timer_mode_strs, nsvc->timer_mode),
+ seconds);
+
+ switch (nsvc->timer_mode) {
+ case NSVC_TIMER_TNS_ALIVE:
+ /* Tns-alive case: we expired without response ! */
+ nsvc->alive_retries++;
+ if (nsvc->alive_retries >
+ nsvc->nsi->timeout[NS_TOUT_TNS_ALIVE_RETRIES]) {
+ /* mark as dead and blocked */
+ nsvc->state = NSE_S_BLOCKED;
+ rate_ctr_inc(&nsvc->ctrg->ctr[NS_CTR_BLOCKED]);
+ rate_ctr_inc(&nsvc->ctrg->ctr[NS_CTR_DEAD]);
+ LOGP(DNS, LOGL_NOTICE,
+ "NSEI=%u Tns-alive expired more then "
+ "%u times, blocking NS-VC\n", nsvc->nsei,
+ nsvc->nsi->timeout[NS_TOUT_TNS_ALIVE_RETRIES]);
+ ns_dispatch_signal(nsvc, S_NS_ALIVE_EXP, 0);
+ ns_dispatch_signal(nsvc, S_NS_BLOCK, NS_CAUSE_NSVC_BLOCKED);
+ return;
+ }
+ /* Tns-test case: send NS-ALIVE PDU */
+ gprs_ns_tx_alive(nsvc);
+ /* start Tns-alive timer */
+ nsvc_start_timer(nsvc, NSVC_TIMER_TNS_ALIVE);
+ break;
+ case NSVC_TIMER_TNS_TEST:
+ /* Tns-test case: send NS-ALIVE PDU */
+ gprs_ns_tx_alive(nsvc);
+ /* start Tns-alive timer (transition into faster
+ * alive retransmissions) */
+ nsvc->alive_retries = 0;
+ nsvc_start_timer(nsvc, NSVC_TIMER_TNS_ALIVE);
+ break;
+ case NSVC_TIMER_TNS_RESET:
+ /* Chapter 7.3: Re-send the RESET */
+ gprs_ns_tx_reset(nsvc, NS_CAUSE_OM_INTERVENTION);
+ /* Re-start Tns-reset timer */
+ nsvc_start_timer(nsvc, NSVC_TIMER_TNS_RESET);
+ break;
+ case _NSVC_TIMER_NR:
+ break;
+ }
+}
+
+/* Section 9.2.6 */
+static int gprs_ns_tx_reset_ack(struct gprs_nsvc *nsvc)
+{
+ struct msgb *msg = gprs_ns_msgb_alloc();
+ struct gprs_ns_hdr *nsh;
+ uint16_t nsvci, nsei;
+
+ log_set_context(BSC_CTX_NSVC, nsvc);
+ if (!msg)
+ return -ENOMEM;
+
+ nsvci = htons(nsvc->nsvci);
+ nsei = htons(nsvc->nsei);
+
+ msg->l2h = msgb_put(msg, sizeof(*nsh));
+ nsh = (struct gprs_ns_hdr *) msg->l2h;
+
+ nsh->pdu_type = NS_PDUT_RESET_ACK;
+
+ LOGP(DNS, LOGL_INFO, "NSEI=%u Tx NS RESET ACK (NSVCI=%u)\n",
+ nsvc->nsei, nsvc->nsvci);
+
+ msgb_tvlv_put(msg, NS_IE_VCI, 2, (uint8_t *)&nsvci);
+ msgb_tvlv_put(msg, NS_IE_NSEI, 2, (uint8_t *)&nsei);
+
+ return gprs_ns_tx(nsvc, msg);
+}
+
+/* Section 9.2.10: transmit side / NS-UNITDATA-REQUEST primitive */
+int gprs_ns_sendmsg(struct gprs_ns_inst *nsi, struct msgb *msg)
+{
+ struct gprs_nsvc *nsvc;
+ struct gprs_ns_hdr *nsh;
+ uint16_t bvci = msgb_bvci(msg);
+
+ nsvc = nsvc_by_nsei(nsi, msgb_nsei(msg));
+ if (!nsvc) {
+ LOGP(DNS, LOGL_ERROR, "Unable to resolve NSEI %u "
+ "to NS-VC!\n", msgb_nsei(msg));
+ msgb_free(msg);
+ return -EINVAL;
+ }
+ log_set_context(BSC_CTX_NSVC, nsvc);
+
+ if (!(nsvc->state & NSE_S_ALIVE)) {
+ LOGP(DNS, LOGL_ERROR, "NSEI=%u is not alive, cannot send\n",
+ nsvc->nsei);
+ msgb_free(msg);
+ return -EBUSY;
+ }
+ if (nsvc->state & NSE_S_BLOCKED) {
+ LOGP(DNS, LOGL_ERROR, "NSEI=%u is blocked, cannot send\n",
+ nsvc->nsei);
+ msgb_free(msg);
+ return -EBUSY;
+ }
+
+ msg->l2h = msgb_push(msg, sizeof(*nsh) + 3);
+ nsh = (struct gprs_ns_hdr *) msg->l2h;
+ if (!nsh) {
+ LOGP(DNS, LOGL_ERROR, "Not enough headroom for NS header\n");
+ msgb_free(msg);
+ return -EIO;
+ }
+
+ nsh->pdu_type = NS_PDUT_UNITDATA;
+ /* spare octet in data[0] */
+ nsh->data[1] = bvci >> 8;
+ nsh->data[2] = bvci & 0xff;
+
+ return gprs_ns_tx(nsvc, msg);
+}
+
+/* Section 9.2.10: receive side */
+static int gprs_ns_rx_unitdata(struct gprs_nsvc *nsvc, struct msgb *msg)
+{
+ struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *)msg->l2h;
+ uint16_t bvci;
+
+ if (nsvc->state & NSE_S_BLOCKED)
+ return gprs_ns_tx_status(nsvc, NS_CAUSE_NSVC_BLOCKED,
+ 0, msg);
+
+ /* spare octet in data[0] */
+ bvci = nsh->data[1] << 8 | nsh->data[2];
+ msgb_bssgph(msg) = &nsh->data[3];
+ msgb_bvci(msg) = bvci;
+
+ /* call upper layer (BSSGP) */
+ return nsvc->nsi->cb(GPRS_NS_EVT_UNIT_DATA, nsvc, msg, bvci);
+}
+
+/* Section 9.2.7 */
+static int gprs_ns_rx_status(struct gprs_nsvc *nsvc, struct msgb *msg)
+{
+ struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h;
+ struct tlv_parsed tp;
+ uint8_t cause;
+ int rc;
+
+ LOGP(DNS, LOGL_NOTICE, "NSEI=%u Rx NS STATUS ", nsvc->nsei);
+
+ rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data,
+ msgb_l2len(msg) - sizeof(*nsh), 0, 0);
+ if (rc < 0) {
+ LOGPC(DNS, LOGL_NOTICE, "Error during TLV Parse\n");
+ LOGP(DNS, LOGL_ERROR, "NSEI=%u Rx NS STATUS: "
+ "Error during TLV Parse\n", nsvc->nsei);
+ return rc;
+ }
+
+ if (!TLVP_PRESENT(&tp, NS_IE_CAUSE)) {
+ LOGPC(DNS, LOGL_INFO, "missing cause IE\n");
+ return -EINVAL;
+ }
+
+ cause = *TLVP_VAL(&tp, NS_IE_CAUSE);
+ LOGPC(DNS, LOGL_NOTICE, "cause=%s\n", gprs_ns_cause_str(cause));
+
+ return 0;
+}
+
+/* Section 7.3 */
+static int gprs_ns_rx_reset(struct gprs_nsvc *nsvc, struct msgb *msg)
+{
+ struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h;
+ struct tlv_parsed tp;
+ uint8_t *cause;
+ uint16_t *nsvci, *nsei;
+ int rc;
+
+ rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data,
+ msgb_l2len(msg) - sizeof(*nsh), 0, 0);
+ if (rc < 0) {
+ LOGP(DNS, LOGL_ERROR, "NSEI=%u Rx NS RESET "
+ "Error during TLV Parse\n", nsvc->nsei);
+ return rc;
+ }
+
+ if (!TLVP_PRESENT(&tp, NS_IE_CAUSE) ||
+ !TLVP_PRESENT(&tp, NS_IE_VCI) ||
+ !TLVP_PRESENT(&tp, NS_IE_NSEI)) {
+ LOGP(DNS, LOGL_ERROR, "NS RESET Missing mandatory IE\n");
+ gprs_ns_tx_status(nsvc, NS_CAUSE_MISSING_ESSENT_IE, 0, msg);
+ return -EINVAL;
+ }
+
+ cause = (uint8_t *) TLVP_VAL(&tp, NS_IE_CAUSE);
+ nsvci = (uint16_t *) TLVP_VAL(&tp, NS_IE_VCI);
+ nsei = (uint16_t *) TLVP_VAL(&tp, NS_IE_NSEI);
+
+ LOGP(DNS, LOGL_INFO, "NSEI=%u Rx NS RESET (NSVCI=%u, cause=%s)\n",
+ nsvc->nsvci, nsvc->nsei, gprs_ns_cause_str(*cause));
+
+ /* Mark NS-VC as blocked and alive */
+ nsvc->state = NSE_S_BLOCKED | NSE_S_ALIVE;
+
+ nsvc->nsei = ntohs(*nsei);
+ nsvc->nsvci = ntohs(*nsvci);
+
+ /* start the test procedure */
+ gprs_ns_tx_simple(nsvc, NS_PDUT_ALIVE);
+ nsvc_start_timer(nsvc, NSVC_TIMER_TNS_TEST);
+
+ /* inform interested parties about the fact that this NSVC
+ * has received RESET */
+ ns_dispatch_signal(nsvc, S_NS_RESET, *cause);
+
+ return gprs_ns_tx_reset_ack(nsvc);
+}
+
+static int gprs_ns_rx_block(struct gprs_nsvc *nsvc, struct msgb *msg)
+{
+ struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h;
+ struct tlv_parsed tp;
+ uint8_t *cause;
+ int rc;
+
+ LOGP(DNS, LOGL_INFO, "NSEI=%u Rx NS BLOCK\n", nsvc->nsei);
+
+ nsvc->state |= NSE_S_BLOCKED;
+
+ rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data,
+ msgb_l2len(msg) - sizeof(*nsh), 0, 0);
+ if (rc < 0) {
+ LOGP(DNS, LOGL_ERROR, "NSEI=%u Rx NS BLOCK "
+ "Error during TLV Parse\n", nsvc->nsei);
+ return rc;
+ }
+
+ if (!TLVP_PRESENT(&tp, NS_IE_CAUSE) ||
+ !TLVP_PRESENT(&tp, NS_IE_VCI)) {
+ LOGP(DNS, LOGL_ERROR, "NS RESET Missing mandatory IE\n");
+ gprs_ns_tx_status(nsvc, NS_CAUSE_MISSING_ESSENT_IE, 0, msg);
+ return -EINVAL;
+ }
+
+ cause = (uint8_t *) TLVP_VAL(&tp, NS_IE_CAUSE);
+ //nsvci = (uint16_t *) TLVP_VAL(&tp, NS_IE_VCI);
+
+ ns_dispatch_signal(nsvc, S_NS_BLOCK, *cause);
+ rate_ctr_inc(&nsvc->ctrg->ctr[NS_CTR_BLOCKED]);
+
+ return gprs_ns_tx_simple(nsvc, NS_PDUT_BLOCK_ACK);
+}
+
+/* main entry point, here incoming NS frames enter */
+int gprs_ns_rcvmsg(struct gprs_ns_inst *nsi, struct msgb *msg,
+ struct sockaddr_in *saddr, enum gprs_ns_ll ll)
+{
+ struct gprs_ns_hdr *nsh = (struct gprs_ns_hdr *) msg->l2h;
+ struct gprs_nsvc *nsvc;
+ int rc = 0;
+
+ /* look up the NSVC based on source address */
+ nsvc = nsvc_by_rem_addr(nsi, saddr);
+ if (!nsvc) {
+ struct tlv_parsed tp;
+ uint16_t nsei;
+ if (nsh->pdu_type == NS_PDUT_STATUS) {
+ LOGP(DNS, LOGL_INFO, "Ignoring NS STATUS from %s:%u "
+ "for non-existing NS-VC\n",
+ inet_ntoa(saddr->sin_addr), ntohs(saddr->sin_port));
+ return 0;
+ }
+ /* Only the RESET procedure creates a new NSVC */
+ if (nsh->pdu_type != NS_PDUT_RESET) {
+ /* Since we have no NSVC, we have to use a fake */
+ nsvc = nsi->unknown_nsvc;
+ log_set_context(BSC_CTX_NSVC, nsvc);
+ LOGP(DNS, LOGL_INFO, "Rejecting NS PDU type 0x%0x "
+ "from %s:%u for non-existing NS-VC\n",
+ nsh->pdu_type, inet_ntoa(saddr->sin_addr),
+ ntohs(saddr->sin_port));
+ nsvc->nsvci = nsvc->nsei = 0xfffe;
+ nsvc->ip.bts_addr = *saddr;
+ nsvc->state = NSE_S_ALIVE;
+ nsvc->ll = ll;
+#if 0
+ return gprs_ns_tx_reset(nsvc, NS_CAUSE_PDU_INCOMP_PSTATE);
+#else
+ return gprs_ns_tx_status(nsvc,
+ NS_CAUSE_PDU_INCOMP_PSTATE, 0,
+ msg);
+#endif
+ }
+ rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data,
+ msgb_l2len(msg) - sizeof(*nsh), 0, 0);
+ if (rc < 0) {
+ LOGP(DNS, LOGL_ERROR, "Rx NS RESET Error %d during "
+ "TLV Parse\n", rc);
+ return rc;
+ }
+ if (!TLVP_PRESENT(&tp, NS_IE_CAUSE) ||
+ !TLVP_PRESENT(&tp, NS_IE_VCI) ||
+ !TLVP_PRESENT(&tp, NS_IE_NSEI)) {
+ LOGP(DNS, LOGL_ERROR, "NS RESET Missing mandatory IE\n");
+ gprs_ns_tx_status(nsvc, NS_CAUSE_MISSING_ESSENT_IE, 0,
+ msg);
+ return -EINVAL;
+ }
+ nsei = ntohs(*(uint16_t *)TLVP_VAL(&tp, NS_IE_NSEI));
+ /* Check if we already know this NSEI, the remote end might
+ * simply have changed addresses, or it is a SGSN */
+ nsvc = nsvc_by_nsei(nsi, nsei);
+ if (!nsvc) {
+ nsvc = nsvc_create(nsi, 0xffff);
+ nsvc->ll = ll;
+ log_set_context(BSC_CTX_NSVC, nsvc);
+ LOGP(DNS, LOGL_INFO, "Creating NS-VC for BSS at %s:%u\n",
+ inet_ntoa(saddr->sin_addr), ntohs(saddr->sin_port));
+ }
+ /* Update the remote peer IP address/port */
+ nsvc->ip.bts_addr = *saddr;
+ } else
+ msgb_nsei(msg) = nsvc->nsei;
+
+ log_set_context(BSC_CTX_NSVC, nsvc);
+
+ /* Increment number of Incoming bytes */
+ rate_ctr_inc(&nsvc->ctrg->ctr[NS_CTR_PKTS_IN]);
+ rate_ctr_add(&nsvc->ctrg->ctr[NS_CTR_BYTES_IN], msgb_l2len(msg));
+
+ switch (nsh->pdu_type) {
+ case NS_PDUT_ALIVE:
+ /* If we're dead and blocked and suddenly receive a
+ * NS-ALIVE out of the blue, we might have been re-started
+ * and should send a NS-RESET to make sure everything recovers
+ * fine. */
+ if (nsvc->state == NSE_S_BLOCKED)
+ rc = gprs_ns_tx_reset(nsvc, NS_CAUSE_PDU_INCOMP_PSTATE);
+ else
+ rc = gprs_ns_tx_alive_ack(nsvc);
+ break;
+ case NS_PDUT_ALIVE_ACK:
+ /* stop Tns-alive and start Tns-test */
+ nsvc_start_timer(nsvc, NSVC_TIMER_TNS_TEST);
+ if (nsvc->remote_end_is_sgsn) {
+ /* FIXME: this should be one level higher */
+ if (nsvc->state & NSE_S_BLOCKED)
+ rc = gprs_ns_tx_unblock(nsvc);
+ }
+ break;
+ case NS_PDUT_UNITDATA:
+ /* actual user data */
+ rc = gprs_ns_rx_unitdata(nsvc, msg);
+ break;
+ case NS_PDUT_STATUS:
+ rc = gprs_ns_rx_status(nsvc, msg);
+ break;
+ case NS_PDUT_RESET:
+ rc = gprs_ns_rx_reset(nsvc, msg);
+ break;
+ case NS_PDUT_RESET_ACK:
+ LOGP(DNS, LOGL_INFO, "NSEI=%u Rx NS RESET ACK\n", nsvc->nsei);
+ /* mark NS-VC as blocked + active */
+ nsvc->state = NSE_S_BLOCKED | NSE_S_ALIVE;
+ nsvc->remote_state = NSE_S_BLOCKED | NSE_S_ALIVE;
+ rate_ctr_inc(&nsvc->ctrg->ctr[NS_CTR_BLOCKED]);
+ if (nsvc->persistent || nsvc->remote_end_is_sgsn) {
+ /* stop RESET timer */
+ bsc_del_timer(&nsvc->timer);
+ }
+ /* Initiate TEST proc.: Send ALIVE and start timer */
+ rc = gprs_ns_tx_simple(nsvc, NS_PDUT_ALIVE);
+ nsvc_start_timer(nsvc, NSVC_TIMER_TNS_TEST);
+ break;
+ case NS_PDUT_UNBLOCK:
+ /* Section 7.2: unblocking procedure */
+ LOGP(DNS, LOGL_INFO, "NSEI=%u Rx NS UNBLOCK\n", nsvc->nsei);
+ nsvc->state &= ~NSE_S_BLOCKED;
+ ns_dispatch_signal(nsvc, S_NS_UNBLOCK, 0);
+ rc = gprs_ns_tx_simple(nsvc, NS_PDUT_UNBLOCK_ACK);
+ break;
+ case NS_PDUT_UNBLOCK_ACK:
+ LOGP(DNS, LOGL_INFO, "NSEI=%u Rx NS UNBLOCK ACK\n", nsvc->nsei);
+ /* mark NS-VC as unblocked + active */
+ nsvc->state = NSE_S_ALIVE;
+ nsvc->remote_state = NSE_S_ALIVE;
+ ns_dispatch_signal(nsvc, S_NS_UNBLOCK, 0);
+ break;
+ case NS_PDUT_BLOCK:
+ rc = gprs_ns_rx_block(nsvc, msg);
+ break;
+ case NS_PDUT_BLOCK_ACK:
+ LOGP(DNS, LOGL_INFO, "NSEI=%u Rx NS BLOCK ACK\n", nsvc->nsei);
+ /* mark remote NS-VC as blocked + active */
+ nsvc->remote_state = NSE_S_BLOCKED | NSE_S_ALIVE;
+ break;
+ default:
+ LOGP(DNS, LOGL_NOTICE, "NSEI=%u Rx Unknown NS PDU type 0x%02x\n",
+ nsvc->nsei, nsh->pdu_type);
+ rc = -EINVAL;
+ break;
+ }
+ return rc;
+}
+
+struct gprs_ns_inst *gprs_ns_instantiate(gprs_ns_cb_t *cb)
+{
+ struct gprs_ns_inst *nsi = talloc_zero(tall_bsc_ctx, struct gprs_ns_inst);
+
+ nsi->cb = cb;
+ INIT_LLIST_HEAD(&nsi->gprs_nsvcs);
+ nsi->timeout[NS_TOUT_TNS_BLOCK] = 3;
+ nsi->timeout[NS_TOUT_TNS_BLOCK_RETRIES] = 3;
+ nsi->timeout[NS_TOUT_TNS_RESET] = 3;
+ nsi->timeout[NS_TOUT_TNS_RESET_RETRIES] = 3;
+ nsi->timeout[NS_TOUT_TNS_TEST] = 30;
+ nsi->timeout[NS_TOUT_TNS_ALIVE] = 3;
+ nsi->timeout[NS_TOUT_TNS_ALIVE_RETRIES] = 10;
+
+ /* Create the dummy NSVC that we use for sending
+ * messages to non-existant/unknown NS-VC's */
+ nsi->unknown_nsvc = nsvc_create(nsi, 0xfffe);
+ llist_del(&nsi->unknown_nsvc->list);
+
+ return nsi;
+}
+
+void gprs_ns_destroy(struct gprs_ns_inst *nsi)
+{
+ /* FIXME: clear all timers */
+
+ /* recursively free the NSI and all its NSVCs */
+ talloc_free(nsi);
+}
+
+
+/* NS-over-IP code, according to 3GPP TS 48.016 Chapter 6.2
+ * We don't support Size Procedure, Configuration Procedure, ChangeWeight Procedure */
+
+/* Read a single NS-over-IP message */
+static struct msgb *read_nsip_msg(struct bsc_fd *bfd, int *error,
+ struct sockaddr_in *saddr)
+{
+ struct msgb *msg = gprs_ns_msgb_alloc();
+ int ret = 0;
+ socklen_t saddr_len = sizeof(*saddr);
+
+ if (!msg) {
+ *error = -ENOMEM;
+ return NULL;
+ }
+
+ ret = recvfrom(bfd->fd, msg->data, NS_ALLOC_SIZE - NS_ALLOC_HEADROOM, 0,
+ (struct sockaddr *)saddr, &saddr_len);
+ if (ret < 0) {
+ LOGP(DNS, LOGL_ERROR, "recv error %s during NSIP recv\n",
+ strerror(errno));
+ msgb_free(msg);
+ *error = ret;
+ return NULL;
+ } else if (ret == 0) {
+ msgb_free(msg);
+ *error = ret;
+ return NULL;
+ }
+
+ msg->l2h = msg->data;
+ msgb_put(msg, ret);
+
+ return msg;
+}
+
+static int handle_nsip_read(struct bsc_fd *bfd)
+{
+ int error;
+ struct sockaddr_in saddr;
+ struct gprs_ns_inst *nsi = bfd->data;
+ struct msgb *msg = read_nsip_msg(bfd, &error, &saddr);
+
+ if (!msg)
+ return error;
+
+ error = gprs_ns_rcvmsg(nsi, msg, &saddr, GPRS_NS_LL_UDP);
+
+ msgb_free(msg);
+
+ return error;
+}
+
+static int handle_nsip_write(struct bsc_fd *bfd)
+{
+ /* FIXME: actually send the data here instead of nsip_sendmsg() */
+ return -EIO;
+}
+
+static int nsip_sendmsg(struct gprs_nsvc *nsvc, struct msgb *msg)
+{
+ int rc;
+ struct gprs_ns_inst *nsi = nsvc->nsi;
+ struct sockaddr_in *daddr = &nsvc->ip.bts_addr;
+
+ rc = sendto(nsi->nsip.fd.fd, msg->data, msg->len, 0,
+ (struct sockaddr *)daddr, sizeof(*daddr));
+
+ talloc_free(msg);
+
+ return rc;
+}
+
+/* UDP Port 23000 carries the LLC-in-BSSGP-in-NS protocol stack */
+static int nsip_fd_cb(struct bsc_fd *bfd, unsigned int what)
+{
+ int rc = 0;
+
+ if (what & BSC_FD_READ)
+ rc = handle_nsip_read(bfd);
+ if (what & BSC_FD_WRITE)
+ rc = handle_nsip_write(bfd);
+
+ return rc;
+}
+
+/* Listen for incoming GPRS packets */
+int gprs_ns_nsip_listen(struct gprs_ns_inst *nsi)
+{
+ int ret;
+
+ ret = make_sock(&nsi->nsip.fd, IPPROTO_UDP, nsi->nsip.local_ip,
+ nsi->nsip.local_port, nsip_fd_cb);
+ if (ret < 0)
+ return ret;
+
+ nsi->nsip.fd.data = nsi;
+
+ return ret;
+}
+
+/* Initiate a RESET procedure */
+void gprs_nsvc_reset(struct gprs_nsvc *nsvc, uint8_t cause)
+{
+ LOGP(DNS, LOGL_INFO, "NSEI=%u RESET procedure based on API request\n",
+ nsvc->nsei);
+
+ /* Mark NS-VC locally as blocked and dead */
+ nsvc->state = NSE_S_BLOCKED;
+ /* Send NS-RESET PDU */
+ if (gprs_ns_tx_reset(nsvc, cause) < 0) {
+ LOGP(DNS, LOGL_ERROR, "NSEI=%u, error resetting NS-VC\n",
+ nsvc->nsei);
+ }
+ /* Start Tns-reset */
+ nsvc_start_timer(nsvc, NSVC_TIMER_TNS_RESET);
+}
+
+/* Establish a connection (from the BSS) to the SGSN */
+struct gprs_nsvc *nsip_connect(struct gprs_ns_inst *nsi,
+ struct sockaddr_in *dest, uint16_t nsei,
+ uint16_t nsvci)
+{
+ struct gprs_nsvc *nsvc;
+
+ nsvc = nsvc_by_rem_addr(nsi, dest);
+ if (!nsvc)
+ nsvc = nsvc_create(nsi, nsvci);
+ nsvc->ip.bts_addr = *dest;
+ nsvc->nsei = nsei;
+ nsvc->nsvci = nsvci;
+ nsvc->remote_end_is_sgsn = 1;
+
+ gprs_nsvc_reset(nsvc, NS_CAUSE_OM_INTERVENTION);
+ return nsvc;
+}