/* 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 * * All Rights Reserved * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 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 General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, write to the Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. * */ /* 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define NS_ALLOC_SIZE 1024 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 */ static 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; 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); static int gprs_ns_tx(struct gprs_nsvc *nsvc, struct msgb *msg) { int ret; /* 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->nsi->ll) { case GPRS_NS_LL_UDP: ret = nsip_sendmsg(nsvc, msg); break; default: LOGP(DNS, LOGL_ERROR, "unsupported NS linklayer %u\n", nsvc->nsi->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 = msgb_alloc(NS_ALLOC_SIZE, "GPRS/NS"); struct gprs_ns_hdr *nsh; 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 = msgb_alloc(NS_ALLOC_SIZE, "GPRS/NS"); struct gprs_ns_hdr *nsh; uint16_t nsvci = htons(nsvc->nsvci); uint16_t nsei = htons(nsvc->nsei); 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 = msgb_alloc(NS_ALLOC_SIZE, "GPRS/NS"); struct gprs_ns_hdr *nsh; uint16_t nsvci = htons(nsvc->nsvci); bvci = htons(bvci); if (!msg) return -ENOMEM; LOGP(DNS, LOGL_INFO, "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 = msgb_alloc(NS_ALLOC_SIZE, "GPRS/NS"); struct gprs_ns_hdr *nsh; uint16_t nsvci = htons(nsvc->nsvci); 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) { 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) { 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) { 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]; 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]; 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 = msgb_alloc(NS_ALLOC_SIZE, "GPRS/NS"); struct gprs_ns_hdr *nsh; uint16_t nsvci, nsei; 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)); return -EINVAL; } if (!(nsvc->state & NSE_S_ALIVE)) { LOGP(DNS, LOGL_ERROR, "NSEI=%u is not alive, cannot send\n", nsvc->nsei); return -EBUSY; } if (nsvc->state & NSE_S_BLOCKED) { LOGP(DNS, LOGL_ERROR, "NSEI=%u is blocked, cannot send\n", nsvc->nsei); 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"); 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_INFO, "NSEI=%u NS STATUS ", nsvc->nsei); rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data, msgb_l2len(msg), 0, 0); 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_INFO, "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), 0, 0); 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 */ nsvc_start_timer(nsvc, NSVC_TIMER_TNS_ALIVE); /* 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), 0, 0); 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) { 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; /* 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; 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; return gprs_ns_tx_status(nsvc, NS_CAUSE_PDU_INCOMP_PSTATE, 0, msg); } rc = tlv_parse(&tp, &ns_att_tlvdef, nsh->data, msgb_l2len(msg), 0, 0); 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) { LOGP(DNS, LOGL_INFO, "Creating NS-VC for BSS at %s:%u\n", inet_ntoa(saddr->sin_addr), ntohs(saddr->sin_port)); nsvc = nsvc_create(nsi, 0xffff); } /* Update the remote peer IP address/port */ nsvc->ip.bts_addr = *saddr; } else msgb_nsei(msg) = nsvc->nsei; /* 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 */ bsc_del_timer(&nsvc->timer); /* 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->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_ALIVE); } 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 = msgb_alloc(NS_ALLOC_SIZE, "Abis/IP/GPRS-NS"); int ret = 0; socklen_t saddr_len = sizeof(*saddr); if (!msg) { *error = -ENOMEM; return NULL; } ret = recvfrom(bfd->fd, msg->data, NS_ALLOC_SIZE, 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); 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; } 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; } extern int make_sock(struct bsc_fd *bfd, int proto, uint16_t port, int (*cb)(struct bsc_fd *fd, unsigned int what)); /* Listen for incoming GPRS packets */ int nsip_listen(struct gprs_ns_inst *nsi, uint16_t udp_port) { int ret; ret = make_sock(&nsi->nsip.fd, IPPROTO_UDP, udp_port, nsip_fd_cb); if (ret < 0) return ret; nsi->ll = GPRS_NS_LL_UDP; nsi->nsip.fd.data = nsi; return ret; } /* 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; /* Initiate a RESET procedure */ /* Mark NS-VC locally as blocked and dead */ nsvc->state = NSE_S_BLOCKED; /* Send NS-RESET PDU */ if (gprs_ns_tx_reset(nsvc, NS_CAUSE_OM_INTERVENTION) < 0) { LOGP(DNS, LOGL_ERROR, "NSEI=%u, error resetting NS-VC\n", nsei); } /* Start Tns-reset */ nsvc_start_timer(nsvc, NSVC_TIMER_TNS_RESET); return nsvc; }