| /* 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 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. |
| */ |
| |
| #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 <openbsc/debug.h> |
| #include <openbsc/gprs_ns.h> |
| #include <openbsc/gprs_bssgp.h> |
| |
| #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 }, |
| }, |
| }; |
| |
| /* 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 */ |
| static 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 (!memcmp(&nsvc->ip.bts_addr, sin, sizeof(*sin))) |
| return nsvc; |
| } |
| return NULL; |
| } |
| |
| static void gprs_ns_timer_cb(void *data); |
| |
| static 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; |
| |
| llist_add(&nsvc->list, &nsi->gprs_nsvcs); |
| |
| return nsvc; |
| } |
| |
| /* 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; |
| |
| switch (nsvc->nsi->ll) { |
| case GPRS_NS_LL_UDP: |
| ret = nsip_sendmsg(nsvc, msg); |
| break; |
| default: |
| LOGP(DGPRS, 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; |
| |
| nsh = (struct gprs_ns_hdr *) msgb_put(msg, sizeof(*nsh)); |
| |
| nsh->pdu_type = pdu_type; |
| |
| return gprs_ns_tx(nsvc, msg); |
| } |
| |
| static 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; |
| |
| nsh = (struct gprs_ns_hdr *) msgb_put(msg, sizeof(*nsh)); |
| 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); |
| |
| } |
| |
| #define NS_ALIVE_RETRIES 10 /* after 3 failed retransmit we declare BTS as dead */ |
| |
| static const uint8_t timer_mode_tout[_NSVC_TIMER_NR] = { |
| [NSVC_TIMER_TNS_RESET] = 60, |
| [NSVC_TIMER_TNS_ALIVE] = 3, |
| [NSVC_TIMER_TNS_TEST] = 30, |
| }; |
| |
| static void nsvc_start_timer(struct gprs_nsvc *nsvc, enum nsvc_timer_mode mode) |
| { |
| nsvc->alive_retries = 0; |
| |
| if (bsc_timer_pending(&nsvc->timer)) |
| bsc_del_timer(&nsvc->timer); |
| |
| nsvc->timer_mode = mode; |
| bsc_schedule_timer(&nsvc->timer, timer_mode_tout[mode], 0); |
| } |
| |
| static void gprs_ns_timer_cb(void *data) |
| { |
| struct gprs_nsvc *nsvc = data; |
| |
| switch (nsvc->timer_mode) { |
| case NSVC_TIMER_TNS_ALIVE: |
| /* Tns-alive case: we expired without response ! */ |
| nsvc->alive_retries++; |
| if (nsvc->alive_retries > NS_ALIVE_RETRIES) { |
| /* mark as dead and blocked */ |
| nsvc->state = NSE_S_BLOCKED; |
| DEBUGP(DGPRS, "NSEI=%u Tns-alive expired more then " |
| "%u times, blocking NS-VC\n", nsvc->nsei, |
| NS_ALIVE_RETRIES); |
| /* FIXME: inform higher layers */ |
| return; |
| } |
| nsvc_start_timer(nsvc, NSVC_TIMER_TNS_ALIVE); |
| break; |
| case NSVC_TIMER_TNS_TEST: |
| /* Tns-test case: send NS-ALIVE PDU */ |
| gprs_ns_tx_simple(nsvc, NS_PDUT_ALIVE); |
| /* start Tns-alive timer */ |
| 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); |
| nsvc_start_timer(nsvc, NSVC_TIMER_TNS_RESET); |
| 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); |
| |
| nsh = (struct gprs_ns_hdr *) msgb_put(msg, sizeof(*nsh)); |
| |
| nsh->pdu_type = NS_PDUT_RESET_ACK; |
| |
| DEBUGP(DGPRS, "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(DGPRS, LOGL_ERROR, "Unable to resolve NSEI %u " |
| "to NS-VC!\n", msgb_nsei(msg)); |
| return -EINVAL; |
| } |
| |
| if (!(nsvc->state & NSE_S_ALIVE)) { |
| LOGP(DGPRS, LOGL_ERROR, "NSEI=%u is not alive, cannot send\n", |
| nsvc->nsei); |
| return -EBUSY; |
| } |
| if (nsvc->state & NSE_S_BLOCKED) { |
| LOGP(DGPRS, LOGL_ERROR, "NSEI=%u is blocked, cannot send\n", |
| nsvc->nsei); |
| return -EBUSY; |
| } |
| |
| nsh = (struct gprs_ns_hdr *) msgb_push(msg, sizeof(*nsh) + 3); |
| if (!nsh) { |
| LOGP(DGPRS, 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; |
| |
| /* 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; |
| |
| DEBUGP(DGPRS, "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)) { |
| DEBUGPC(DGPRS, "missing cause IE\n"); |
| return -EINVAL; |
| } |
| |
| cause = *TLVP_VAL(&tp, NS_IE_CAUSE); |
| DEBUGPC(DGPRS, "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)) { |
| /* FIXME: respond with NS_CAUSE_MISSING_ESSENT_IE */ |
| LOGP(DGPRS, LOGL_ERROR, "NS RESET Missing mandatory IE\n"); |
| 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); |
| |
| DEBUGP(DGPRS, "NSEI=%u NS RESET (NSVCI=%u, cause=%s)\n", |
| nsvc->nsvci, nsvc->nsei, gprs_ns_cause_str(*cause)); |
| |
| nsvc->state = NSE_S_BLOCKED | NSE_S_ALIVE; |
| nsvc->nsei = ntohs(*nsei); |
| nsvc->nsvci = ntohs(*nsvci); |
| |
| /* mark the NS-VC as blocked and alive */ |
| /* start the test procedure */ |
| nsvc_start_timer(nsvc, NSVC_TIMER_TNS_ALIVE); |
| |
| return gprs_ns_tx_reset_ack(nsvc); |
| } |
| |
| /* 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) { |
| /* Only the RESET procedure creates a new NSVC */ |
| if (nsh->pdu_type != NS_PDUT_RESET) { |
| LOGP(DGPRS, LOGL_INFO, "Ignoring NS PDU type 0x%0x " |
| "from %s for non-existing NS-VC\n", |
| nsh->pdu_type, inet_ntoa(saddr->sin_addr)); |
| //gprs_ns_tx_reset(nsvc, NS_CAUSE_NSVC_UNKNOWN); |
| return -EIO; |
| } |
| LOGP(DGPRS, 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); |
| nsvc->ip.bts_addr = *saddr; |
| } else |
| msgb_nsei(msg) = nsvc->nsei; |
| |
| switch (nsh->pdu_type) { |
| case NS_PDUT_ALIVE: |
| /* remote end inquires whether we're still alive, |
| * we need to respond with ALIVE_ACK */ |
| rc = gprs_ns_tx_simple(nsvc, NS_PDUT_ALIVE_ACK); |
| 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_simple(nsvc, NS_PDUT_UNBLOCK); |
| } |
| 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: |
| DEBUGP(DGPRS, "NSEI=%u Rx NS RESET ACK\n", nsvc->nsei); |
| /* mark remote NS-VC as blocked + active */ |
| nsvc->remote_state = NSE_S_BLOCKED | NSE_S_ALIVE; |
| if (nsvc->remote_end_is_sgsn) { |
| /* stop RESET timer */ |
| bsc_del_timer(&nsvc->timer); |
| /* send ALIVE PDU */ |
| rc = gprs_ns_tx_simple(nsvc, NS_PDUT_ALIVE); |
| nsvc_start_timer(nsvc, NSVC_TIMER_TNS_ALIVE); |
| /* mark local state as BLOCKED + ALIVE */ |
| nsvc->state = NSE_S_BLOCKED | NSE_S_ALIVE; |
| } |
| break; |
| case NS_PDUT_UNBLOCK: |
| /* Section 7.2: unblocking procedure */ |
| DEBUGP(DGPRS, "NSEI=%u Rx NS UNBLOCK\n", nsvc->nsei); |
| nsvc->state &= ~NSE_S_BLOCKED; |
| rc = gprs_ns_tx_simple(nsvc, NS_PDUT_UNBLOCK_ACK); |
| break; |
| case NS_PDUT_UNBLOCK_ACK: |
| DEBUGP(DGPRS, "NSEI=%u Rx NS UNBLOCK ACK\n", nsvc->nsei); |
| /* mark remote NS-VC as unblocked + active */ |
| nsvc->remote_state = NSE_S_ALIVE; |
| if (nsvc->remote_end_is_sgsn) |
| nsvc->state = NSE_S_ALIVE; |
| break; |
| case NS_PDUT_BLOCK: |
| DEBUGP(DGPRS, "NSEI=%u Rx NS BLOCK\n", nsvc->nsei); |
| nsvc->state |= NSE_S_BLOCKED; |
| rc = gprs_ns_tx_simple(nsvc, NS_PDUT_UNBLOCK_ACK); |
| break; |
| case NS_PDUT_BLOCK_ACK: |
| DEBUGP(DGPRS, "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: |
| DEBUGP(DGPRS, "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); |
| |
| 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(DGPRS, 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; |
| |
| return gprs_ns_rcvmsg(nsi, msg, &saddr); |
| } |
| |
| 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; |
| } |
| |
| |
| /* FIXME: this is currently in input/ipaccess.c */ |
| 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 */ |
| if (gprs_ns_tx_reset(nsvc, NS_CAUSE_OM_INTERVENTION) < 0) { |
| LOGP(DGPRS, LOGL_ERROR, "NSEI=%u, error resetting NS-VC\n", |
| nsei); |
| } |
| /* run a timer and re-transmit the reset request? */ |
| nsvc_start_timer(nsvc, NSVC_TIMER_TNS_RESET); |
| |
| return nsvc; |
| } |