/* OpenBSC Abis/IP proxy ip.access nanoBTS */ /* (C) 2009 by Harald Welte * (C) 2010 by On-Waves * (C) 2010 by Holger Hans Peter Freyther * * 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 . * */ #include #include #include #include #include #include #include #include #include #include #include #include #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include /* one instance of an ip.access protocol proxy */ struct ipa_proxy { /* socket where we listen for incoming OML from BTS */ struct osmo_fd oml_listen_fd; /* socket where we listen for incoming RSL from BTS */ struct osmo_fd rsl_listen_fd; /* list of BTS's (struct ipa_bts_conn */ struct llist_head bts_list; /* the BSC reconnect timer */ struct osmo_timer_list reconn_timer; /* global GPRS NS data */ struct in_addr gprs_addr; struct in_addr listen_addr; }; /* global pointer to the proxy structure */ static struct ipa_proxy *ipp; struct ipa_proxy_conn { struct osmo_fd fd; struct llist_head tx_queue; struct ipa_bts_conn *bts_conn; }; #define MAX_TRX 4 /* represents a particular BTS in our proxy */ struct ipa_bts_conn { /* list of BTS's (ipa_proxy->bts_list) */ struct llist_head list; /* back pointer to the proxy which we belong to */ struct ipa_proxy *ipp; /* the unit ID as determined by CCM */ struct { uint16_t site_id; uint16_t bts_id; } unit_id; /* incoming connections from BTS */ struct ipa_proxy_conn *oml_conn; struct ipa_proxy_conn *rsl_conn[MAX_TRX]; /* outgoing connections to BSC */ struct ipa_proxy_conn *bsc_oml_conn; struct ipa_proxy_conn *bsc_rsl_conn[MAX_TRX]; /* UDP sockets for BTS and BSC injection */ struct osmo_fd udp_bts_fd; struct osmo_fd udp_bsc_fd; /* NS data */ struct in_addr bts_addr; struct osmo_fd gprs_ns_fd; int gprs_local_port; uint16_t gprs_orig_port; uint32_t gprs_orig_ip; char *id_tags[256]; uint8_t *id_resp; unsigned int id_resp_len; }; enum ipp_fd_type { OML_FROM_BTS = 1, RSL_FROM_BTS = 2, OML_TO_BSC = 3, RSL_TO_BSC = 4, UDP_TO_BTS = 5, UDP_TO_BSC = 6, }; extern void *tall_bsc_ctx; static char *listen_ipaddr; static char *bsc_ipaddr; static char *gprs_ns_ipaddr; static int gprs_ns_cb(struct osmo_fd *bfd, unsigned int what); #define PROXY_ALLOC_SIZE 1200 static struct ipa_bts_conn *find_bts_by_unitid(struct ipa_proxy *ipp, uint16_t site_id, uint16_t bts_id) { struct ipa_bts_conn *ipbc; llist_for_each_entry(ipbc, &ipp->bts_list, list) { if (ipbc->unit_id.site_id == site_id && ipbc->unit_id.bts_id == bts_id) return ipbc; } return NULL; } struct ipa_proxy_conn *alloc_conn(void) { struct ipa_proxy_conn *ipc; ipc = talloc_zero(tall_bsc_ctx, struct ipa_proxy_conn); if (!ipc) return NULL; INIT_LLIST_HEAD(&ipc->tx_queue); return ipc; } static int store_idtags(struct ipa_bts_conn *ipbc, struct tlv_parsed *tlvp) { unsigned int i, len; for (i = 0; i <= 0xff; i++) { if (!TLVP_PRESENT(tlvp, i)) continue; len = TLVP_LEN(tlvp, i); #if 0 if (!ipbc->id_tags[i]) ipbc->id_tags[i] = talloc_size(tall_bsc_ctx, len); else #endif ipbc->id_tags[i] = talloc_realloc_size(ipbc, ipbc->id_tags[i], len); if (!ipbc->id_tags[i]) return -ENOMEM; memset(ipbc->id_tags[i], 0, len); //memcpy(ipbc->id_tags[i], TLVP_VAL(tlvp, i), len); } return 0; } static struct ipa_proxy_conn *connect_bsc(struct sockaddr_in *sa, int priv_nr, void *data); #define logp_ipbc_uid(ss, lvl, ipbc, trx_id) _logp_ipbc_uid(ss, lvl, __FILE__, __LINE__, ipbc, trx_id) static void _logp_ipbc_uid(unsigned int ss, unsigned int lvl, char *file, int line, struct ipa_bts_conn *ipbc, uint8_t trx_id) { if (ipbc) logp2(ss, lvl, file, line, 0, "(%u/%u/%u) ", ipbc->unit_id.site_id, ipbc->unit_id.bts_id, trx_id); else logp2(ss, lvl, file, line, 0, "unknown "); } static int handle_udp_read(struct osmo_fd *bfd) { struct ipa_bts_conn *ipbc = bfd->data; struct ipa_proxy_conn *other_conn = NULL; struct msgb *msg = msgb_alloc(PROXY_ALLOC_SIZE, "Abis/IP UDP"); struct ipaccess_head *hh; int ret; /* with UDP sockets, we cannot read partial packets but have to read * all of it in one go */ hh = (struct ipaccess_head *) msg->data; ret = recv(bfd->fd, msg->data, msg->data_len, 0); if (ret < 0) { if (errno != EAGAIN) LOGP(DLINP, LOGL_ERROR, "recv error %s\n", strerror(errno)); msgb_free(msg); return ret; } if (ret == 0) { DEBUGP(DLINP, "UDP peer disappeared, dead socket\n"); osmo_fd_unregister(bfd); close(bfd->fd); bfd->fd = -1; msgb_free(msg); return -EIO; } if (ret < sizeof(*hh)) { DEBUGP(DLINP, "could not even read header!?!\n"); msgb_free(msg); return -EIO; } msgb_put(msg, ret); msg->l2h = msg->data + sizeof(*hh); DEBUGP(DLMI, "UDP RX: %s\n", osmo_hexdump(msg->data, msg->len)); if (hh->len != msg->len - sizeof(*hh)) { DEBUGP(DLINP, "length (%u/%u) disagrees with header(%u)\n", msg->len, msg->len - 3, hh->len); msgb_free(msg); return -EIO; } switch (bfd->priv_nr & 0xff) { case UDP_TO_BTS: /* injection towards BTS */ switch (hh->proto) { case IPAC_PROTO_RSL: /* FIXME: what to do about TRX > 0 */ other_conn = ipbc->rsl_conn[0]; break; default: DEBUGP(DLINP, "Unknown protocol 0x%02x, sending to " "OML FD\n", hh->proto); /* fall through */ case IPAC_PROTO_IPACCESS: case IPAC_PROTO_OML: other_conn = ipbc->oml_conn; break; } break; case UDP_TO_BSC: /* injection towards BSC */ switch (hh->proto) { case IPAC_PROTO_RSL: /* FIXME: what to do about TRX > 0 */ other_conn = ipbc->bsc_rsl_conn[0]; break; default: DEBUGP(DLINP, "Unknown protocol 0x%02x, sending to " "OML FD\n", hh->proto); /* fall through */ case IPAC_PROTO_IPACCESS: case IPAC_PROTO_OML: other_conn = ipbc->bsc_oml_conn; break; } break; default: DEBUGP(DLINP, "Unknown filedescriptor priv_nr=%04x\n", bfd->priv_nr); break; } if (other_conn) { /* enqueue the message for TX on the respective FD */ msgb_enqueue(&other_conn->tx_queue, msg); other_conn->fd.when |= BSC_FD_WRITE; } else msgb_free(msg); return 0; } static int handle_udp_write(struct osmo_fd *bfd) { /* not implemented yet */ bfd->when &= ~BSC_FD_WRITE; return -EIO; } /* callback from select.c in case one of the fd's can be read/written */ static int udp_fd_cb(struct osmo_fd *bfd, unsigned int what) { int rc = 0; if (what & BSC_FD_READ) rc = handle_udp_read(bfd); if (what & BSC_FD_WRITE) rc = handle_udp_write(bfd); return rc; } static int ipbc_alloc_connect(struct ipa_proxy_conn *ipc, struct osmo_fd *bfd, uint16_t site_id, uint16_t bts_id, uint16_t trx_id, struct tlv_parsed *tlvp, struct msgb *msg) { struct ipa_bts_conn *ipbc; uint16_t udp_port; int ret = 0; struct sockaddr_in sin; memset(&sin, 0, sizeof(sin)); sin.sin_family = AF_INET; inet_aton(bsc_ipaddr, &sin.sin_addr); DEBUGP(DLINP, "(%u/%u/%u) New BTS connection: ", site_id, bts_id, trx_id); /* OML needs to be established before RSL */ if ((bfd->priv_nr & 0xff) != OML_FROM_BTS) { DEBUGPC(DLINP, "Not a OML connection ?!?\n"); return -EIO; } /* allocate new BTS connection data structure */ ipbc = talloc_zero(tall_bsc_ctx, struct ipa_bts_conn); if (!ipbc) { ret = -ENOMEM; goto err_out; } DEBUGPC(DLINP, "Created BTS Conn data structure\n"); ipbc->ipp = ipp; ipbc->unit_id.site_id = site_id; ipbc->unit_id.bts_id = bts_id; ipbc->oml_conn = ipc; ipc->bts_conn = ipbc; /* store the content of the ID TAGS for later reference */ store_idtags(ipbc, tlvp); ipbc->id_resp_len = msg->len; ipbc->id_resp = talloc_size(tall_bsc_ctx, ipbc->id_resp_len); memcpy(ipbc->id_resp, msg->data, ipbc->id_resp_len); /* Create OML TCP connection towards BSC */ sin.sin_port = htons(IPA_TCP_PORT_OML); ipbc->bsc_oml_conn = connect_bsc(&sin, OML_TO_BSC, ipbc); if (!ipbc->bsc_oml_conn) { ret = -EIO; goto err_bsc_conn; } DEBUGP(DLINP, "(%u/%u/%u) OML Connected to BSC\n", site_id, bts_id, trx_id); /* Create UDP socket for BTS packet injection */ udp_port = 10000 + (site_id % 1000)*100 + (bts_id % 100); ipbc->udp_bts_fd.priv_nr = UDP_TO_BTS; ipbc->udp_bts_fd.cb = udp_fd_cb; ipbc->udp_bts_fd.data = ipbc; ret = osmo_sock_init_ofd(&ipbc->udp_bts_fd, AF_INET, SOCK_DGRAM, IPPROTO_UDP, NULL, udp_port, OSMO_SOCK_F_BIND); if (ret < 0) goto err_udp_bts; DEBUGP(DLINP, "(%u/%u/%u) Created UDP socket for injection " "towards BTS at port %u\n", site_id, bts_id, trx_id, udp_port); /* Create UDP socket for BSC packet injection */ udp_port = 20000 + (site_id % 1000)*100 + (bts_id % 100); ipbc->udp_bsc_fd.priv_nr = UDP_TO_BSC; ipbc->udp_bsc_fd.cb = udp_fd_cb; ipbc->udp_bsc_fd.data = ipbc; ret = osmo_sock_init_ofd(&ipbc->udp_bsc_fd, AF_INET, SOCK_DGRAM, IPPROTO_UDP, NULL, udp_port, OSMO_SOCK_F_BIND); if (ret < 0) goto err_udp_bsc; DEBUGP(DLINP, "(%u/%u/%u) Created UDP socket for injection " "towards BSC at port %u\n", site_id, bts_id, trx_id, udp_port); /* GPRS NS related code */ if (gprs_ns_ipaddr) { struct sockaddr_in sock; socklen_t len = sizeof(sock); ipbc->gprs_ns_fd.priv_nr = 0; ipbc->gprs_ns_fd.cb = gprs_ns_cb; ipbc->gprs_ns_fd.data = ipbc; ret = osmo_sock_init_ofd(&ipbc->gprs_ns_fd, AF_INET, SOCK_DGRAM, IPPROTO_UDP, listen_ipaddr, 0, OSMO_SOCK_F_BIND); if (ret < 0) { LOGP(DLINP, LOGL_ERROR, "Creating the GPRS socket failed.\n"); goto err_udp_bsc; } ret = getsockname(ipbc->gprs_ns_fd.fd, (struct sockaddr* ) &sock, &len); ipbc->gprs_local_port = ntohs(sock.sin_port); LOGP(DLINP, LOGL_NOTICE, "Created GPRS NS Socket. Listening on: %s:%d\n", inet_ntoa(sock.sin_addr), ipbc->gprs_local_port); ret = getpeername(bfd->fd, (struct sockaddr* ) &sock, &len); ipbc->bts_addr = sock.sin_addr; } llist_add(&ipbc->list, &ipp->bts_list); return 0; err_udp_bsc: osmo_fd_unregister(&ipbc->udp_bts_fd); err_udp_bts: osmo_fd_unregister(&ipbc->bsc_oml_conn->fd); close(ipbc->bsc_oml_conn->fd.fd); talloc_free(ipbc->bsc_oml_conn); ipbc->bsc_oml_conn = NULL; err_bsc_conn: talloc_free(ipbc->id_resp); talloc_free(ipbc); #if 0 osmo_fd_unregister(bfd); close(bfd->fd); talloc_free(bfd); #endif err_out: return ret; } static int ipaccess_rcvmsg(struct ipa_proxy_conn *ipc, struct msgb *msg, struct osmo_fd *bfd) { struct tlv_parsed tlvp; uint8_t msg_type = *(msg->l2h); struct ipaccess_unit unit_data; struct ipa_bts_conn *ipbc; int ret = 0; switch (msg_type) { case IPAC_MSGT_PING: ret = ipa_ccm_send_pong(bfd->fd); break; case IPAC_MSGT_PONG: DEBUGP(DLMI, "PONG!\n"); break; case IPAC_MSGT_ID_RESP: DEBUGP(DLMI, "ID_RESP "); /* parse tags, search for Unit ID */ ret = ipa_ccm_id_resp_parse(&tlvp, (uint8_t *)msg->l2h+1, msgb_l2len(msg)-1); if (ret < 0) { LOGP(DLINP, LOGL_ERROR, "Error parsing CCM ID RESP !?!\n"); return -EIO; } DEBUGP(DLMI, "\n"); if (!TLVP_PRESENT(&tlvp, IPAC_IDTAG_UNIT)) { LOGP(DLINP, LOGL_ERROR, "No Unit ID in ID RESPONSE !?!\n"); return -EIO; } /* lookup BTS, create sign_link, ... */ memset(&unit_data, 0, sizeof(unit_data)); ipa_parse_unitid((char *)TLVP_VAL(&tlvp, IPAC_IDTAG_UNIT), &unit_data); ipbc = find_bts_by_unitid(ipp, unit_data.site_id, unit_data.bts_id); if (!ipbc) { /* We have not found an ipbc (per-bts proxy instance) * for this BTS yet. The first connection of a new BTS must * be a OML connection. We allocate the associated data structures, * and try to connect to the remote end */ return ipbc_alloc_connect(ipc, bfd, unit_data.site_id, unit_data.bts_id, unit_data.trx_id, &tlvp, msg); /* if this fails, the caller will clean up bfd */ } else { struct sockaddr_in sin; memset(&sin, 0, sizeof(sin)); sin.sin_family = AF_INET; inet_aton(bsc_ipaddr, &sin.sin_addr); DEBUGP(DLINP, "Identified BTS %u/%u/%u\n", unit_data.site_id, unit_data.bts_id, unit_data.trx_id); if ((bfd->priv_nr & 0xff) != RSL_FROM_BTS) { LOGP(DLINP, LOGL_ERROR, "Second OML connection from " "same BTS ?!?\n"); return 0; } if (unit_data.trx_id >= MAX_TRX) { LOGP(DLINP, LOGL_ERROR, "We don't support more " "than %u TRX\n", MAX_TRX); return -EINVAL; } ipc->bts_conn = ipbc; /* store TRX number in higher 8 bit of the bfd private number */ bfd->priv_nr |= unit_data.trx_id << 8; ipbc->rsl_conn[unit_data.trx_id] = ipc; /* Create RSL TCP connection towards BSC */ sin.sin_port = htons(IPA_TCP_PORT_RSL); ipbc->bsc_rsl_conn[unit_data.trx_id] = connect_bsc(&sin, RSL_TO_BSC | (unit_data.trx_id << 8), ipbc); if (!ipbc->bsc_oml_conn) return -EIO; DEBUGP(DLINP, "(%u/%u/%u) Connected RSL to BSC\n", unit_data.site_id, unit_data.bts_id, unit_data.trx_id); } break; case IPAC_MSGT_ID_GET: DEBUGP(DLMI, "ID_GET\n"); if ((bfd->priv_nr & 0xff) != OML_TO_BSC && (bfd->priv_nr & 0xff) != RSL_TO_BSC) { DEBUGP(DLINP, "IDentity REQuest from BTS ?!?\n"); return -EIO; } ipbc = ipc->bts_conn; if (!ipbc) { DEBUGP(DLINP, "ID_GET from BSC before we have ID_RESP from BTS\n"); return -EIO; } ret = write(bfd->fd, ipbc->id_resp, ipbc->id_resp_len); if (ret != ipbc->id_resp_len) { LOGP(DLINP, LOGL_ERROR, "Partial write: %d of %d\n", ret, ipbc->id_resp_len); return -EIO; } ret = 0; break; case IPAC_MSGT_ID_ACK: DEBUGP(DLMI, "ID_ACK? -> ACK!\n"); ret = ipa_ccm_send_id_ack(bfd->fd); break; default: LOGP(DLMI, LOGL_ERROR, "Unhandled IPA type; %d\n", msg_type); return 1; break; } return ret; } struct msgb *ipaccess_proxy_read_msg(struct osmo_fd *bfd, int *error) { struct msgb *msg = msgb_alloc(PROXY_ALLOC_SIZE, "Abis/IP"); struct ipaccess_head *hh; int len, ret = 0; if (!msg) { *error = -ENOMEM; return NULL; } /* first read our 3-byte header */ hh = (struct ipaccess_head *) msg->data; ret = recv(bfd->fd, msg->data, 3, 0); if (ret < 0) { if (errno != EAGAIN) LOGP(DLINP, LOGL_ERROR, "recv error: %s\n", strerror(errno)); msgb_free(msg); *error = ret; return NULL; } else if (ret == 0) { msgb_free(msg); *error = ret; return NULL; } msgb_put(msg, ret); /* then read te length as specified in header */ msg->l2h = msg->data + sizeof(*hh); len = ntohs(hh->len); ret = recv(bfd->fd, msg->l2h, len, 0); if (ret < len) { LOGP(DLINP, LOGL_ERROR, "short read!\n"); msgb_free(msg); *error = -EIO; return NULL; } msgb_put(msg, ret); return msg; } static struct ipa_proxy_conn *ipc_by_priv_nr(struct ipa_bts_conn *ipbc, unsigned int priv_nr) { struct ipa_proxy_conn *bsc_conn; unsigned int trx_id = priv_nr >> 8; switch (priv_nr & 0xff) { case OML_FROM_BTS: /* incoming OML data from BTS, forward to BSC OML */ bsc_conn = ipbc->bsc_oml_conn; break; case RSL_FROM_BTS: /* incoming RSL data from BTS, forward to BSC RSL */ bsc_conn = ipbc->bsc_rsl_conn[trx_id]; break; case OML_TO_BSC: /* incoming OML data from BSC, forward to BTS OML */ bsc_conn = ipbc->oml_conn; break; case RSL_TO_BSC: /* incoming RSL data from BSC, forward to BTS RSL */ bsc_conn = ipbc->rsl_conn[trx_id]; break; default: bsc_conn = NULL; break; } return bsc_conn; } static void reconn_tmr_cb(void *data) { struct ipa_proxy *ipp = data; struct ipa_bts_conn *ipbc; struct sockaddr_in sin; int i; DEBUGP(DLINP, "Running reconnect timer\n"); memset(&sin, 0, sizeof(sin)); sin.sin_family = AF_INET; inet_aton(bsc_ipaddr, &sin.sin_addr); llist_for_each_entry(ipbc, &ipp->bts_list, list) { /* if OML to BSC is dead, try to restore it */ if (ipbc->oml_conn && !ipbc->bsc_oml_conn) { sin.sin_port = htons(IPA_TCP_PORT_OML); logp_ipbc_uid(DLINP, LOGL_NOTICE, ipbc, 0); LOGPC(DLINP, LOGL_NOTICE, "OML Trying to reconnect\n"); ipbc->bsc_oml_conn = connect_bsc(&sin, OML_TO_BSC, ipbc); if (!ipbc->bsc_oml_conn) goto reschedule; logp_ipbc_uid(DLINP, LOGL_NOTICE, ipbc, 0); LOGPC(DLINP, LOGL_NOTICE, "OML Reconnected\n"); } /* if we (still) don't have a OML connection, skip RSL */ if (!ipbc->oml_conn || !ipbc->bsc_oml_conn) continue; for (i = 0; i < ARRAY_SIZE(ipbc->rsl_conn); i++) { unsigned int priv_nr; /* don't establish RSL links which we don't have */ if (!ipbc->rsl_conn[i]) continue; if (ipbc->bsc_rsl_conn[i]) continue; priv_nr = ipbc->rsl_conn[i]->fd.priv_nr; priv_nr &= ~0xff; priv_nr |= RSL_TO_BSC; sin.sin_port = htons(IPA_TCP_PORT_RSL); logp_ipbc_uid(DLINP, LOGL_NOTICE, ipbc, priv_nr >> 8); LOGPC(DLINP, LOGL_NOTICE, "RSL Trying to reconnect\n"); ipbc->bsc_rsl_conn[i] = connect_bsc(&sin, priv_nr, ipbc); if (!ipbc->bsc_rsl_conn[i]) goto reschedule; logp_ipbc_uid(DLINP, LOGL_NOTICE, ipbc, priv_nr >> 8); LOGPC(DLINP, LOGL_NOTICE, "RSL Reconnected\n"); } } return; reschedule: osmo_timer_schedule(&ipp->reconn_timer, 5, 0); } static void handle_dead_socket(struct osmo_fd *bfd) { struct ipa_proxy_conn *ipc = bfd->data; /* local conn */ struct ipa_proxy_conn *bsc_conn; /* remote conn */ struct ipa_bts_conn *ipbc = ipc->bts_conn; unsigned int trx_id = bfd->priv_nr >> 8; struct msgb *msg, *msg2; osmo_fd_unregister(bfd); close(bfd->fd); bfd->fd = -1; /* FIXME: clear tx_queue, remove all references, etc. */ llist_for_each_entry_safe(msg, msg2, &ipc->tx_queue, list) msgb_free(msg); switch (bfd->priv_nr & 0xff) { case OML_FROM_BTS: /* incoming OML data from BTS, forward to BSC OML */ /* The BTS started a connection with us but we got no * IPAC_MSGT_ID_RESP message yet, in that scenario we did not * allocate the ipa_bts_conn structure. */ if (ipbc == NULL) break; ipbc->oml_conn = NULL; bsc_conn = ipbc->bsc_oml_conn; /* close the connection to the BSC */ osmo_fd_unregister(&bsc_conn->fd); close(bsc_conn->fd.fd); llist_for_each_entry_safe(msg, msg2, &bsc_conn->tx_queue, list) msgb_free(msg); talloc_free(bsc_conn); ipbc->bsc_oml_conn = NULL; /* FIXME: do we need to delete the entire ipbc ? */ break; case RSL_FROM_BTS: /* incoming RSL data from BTS, forward to BSC RSL */ ipbc->rsl_conn[trx_id] = NULL; bsc_conn = ipbc->bsc_rsl_conn[trx_id]; /* close the connection to the BSC */ osmo_fd_unregister(&bsc_conn->fd); close(bsc_conn->fd.fd); llist_for_each_entry_safe(msg, msg2, &bsc_conn->tx_queue, list) msgb_free(msg); talloc_free(bsc_conn); ipbc->bsc_rsl_conn[trx_id] = NULL; break; case OML_TO_BSC: /* incoming OML data from BSC, forward to BTS OML */ ipbc->bsc_oml_conn = NULL; bsc_conn = ipbc->oml_conn; /* start reconnect timer */ osmo_timer_schedule(&ipp->reconn_timer, 5, 0); break; case RSL_TO_BSC: /* incoming RSL data from BSC, forward to BTS RSL */ ipbc->bsc_rsl_conn[trx_id] = NULL; bsc_conn = ipbc->rsl_conn[trx_id]; /* start reconnect timer */ osmo_timer_schedule(&ipp->reconn_timer, 5, 0); break; default: bsc_conn = NULL; break; } talloc_free(ipc); } static void patch_gprs_msg(struct ipa_bts_conn *ipbc, int priv_nr, struct msgb *msg) { uint8_t *nsvci; if ((priv_nr & 0xff) != OML_FROM_BTS && (priv_nr & 0xff) != OML_TO_BSC) return; if (msgb_l2len(msg) != 39) return; /* * Check if this is a IPA Set Attribute or IPA Set Attribute ACK * and if the FOM Class is GPRS NSVC0 and then we will patch it. * * The patch assumes the message looks like the one from the trace * but we only match messages with a specific size anyway... So * this hack should work just fine. */ if (msg->l2h[0] == 0x10 && msg->l2h[1] == 0x80 && msg->l2h[2] == 0x00 && msg->l2h[3] == 0x15 && msg->l2h[18] == 0xf5 && msg->l2h[19] == 0xf2) { nsvci = &msg->l2h[23]; ipbc->gprs_orig_port = *(uint16_t *)(nsvci+8); ipbc->gprs_orig_ip = *(uint32_t *)(nsvci+10); *(uint16_t *)(nsvci+8) = htons(ipbc->gprs_local_port); *(uint32_t *)(nsvci+10) = ipbc->ipp->listen_addr.s_addr; } else if (msg->l2h[0] == 0x10 && msg->l2h[1] == 0x80 && msg->l2h[2] == 0x00 && msg->l2h[3] == 0x15 && msg->l2h[18] == 0xf6 && msg->l2h[19] == 0xf2) { nsvci = &msg->l2h[23]; *(uint16_t *)(nsvci+8) = ipbc->gprs_orig_port; *(uint32_t *)(nsvci+10) = ipbc->gprs_orig_ip; } } static int handle_tcp_read(struct osmo_fd *bfd) { struct ipa_proxy_conn *ipc = bfd->data; struct ipa_bts_conn *ipbc = ipc->bts_conn; struct ipa_proxy_conn *bsc_conn; struct msgb *msg; struct ipaccess_head *hh; int ret = 0; char *btsbsc; if ((bfd->priv_nr & 0xff) <= 2) btsbsc = "BTS"; else btsbsc = "BSC"; msg = ipaccess_proxy_read_msg(bfd, &ret); if (!msg) { if (ret == 0) { logp_ipbc_uid(DLINP, LOGL_NOTICE, ipbc, bfd->priv_nr >> 8); LOGPC(DLINP, LOGL_NOTICE, "%s disappeared, " "dead socket\n", btsbsc); handle_dead_socket(bfd); } return ret; } msgb_put(msg, ret); logp_ipbc_uid(DLMI, LOGL_DEBUG, ipbc, bfd->priv_nr >> 8); DEBUGPC(DLMI, "RX<-%s: %s\n", btsbsc, osmo_hexdump(msg->data, msg->len)); hh = (struct ipaccess_head *) msg->data; if (hh->proto == IPAC_PROTO_IPACCESS) { ret = ipaccess_rcvmsg(ipc, msg, bfd); if (ret < 0) { osmo_fd_unregister(bfd); close(bfd->fd); bfd->fd = -1; talloc_free(bfd); msgb_free(msg); return ret; } else if (ret == 0) { /* we do not forward parts of the CCM protocol * through the proxy but rather terminate it ourselves. */ msgb_free(msg); return ret; } } if (!ipbc) { LOGP(DLINP, LOGL_ERROR, "received %s packet but no ipc->bts_conn?!?\n", btsbsc); msgb_free(msg); return -EIO; } bsc_conn = ipc_by_priv_nr(ipbc, bfd->priv_nr); if (bsc_conn) { if (gprs_ns_ipaddr) patch_gprs_msg(ipbc, bfd->priv_nr, msg); /* enqueue packet towards BSC */ msgb_enqueue(&bsc_conn->tx_queue, msg); /* mark respective filedescriptor as 'we want to write' */ bsc_conn->fd.when |= BSC_FD_WRITE; } else { logp_ipbc_uid(DLINP, LOGL_INFO, ipbc, bfd->priv_nr >> 8); LOGPC(DLINP, LOGL_INFO, "Dropping packet from %s, " "since remote connection is dead\n", btsbsc); msgb_free(msg); } return ret; } /* a TCP socket is ready to be written to */ static int handle_tcp_write(struct osmo_fd *bfd) { struct ipa_proxy_conn *ipc = bfd->data; struct ipa_bts_conn *ipbc = ipc->bts_conn; struct llist_head *lh; struct msgb *msg; char *btsbsc; int ret; if ((bfd->priv_nr & 0xff) <= 2) btsbsc = "BTS"; else btsbsc = "BSC"; /* get the next msg for this timeslot */ if (llist_empty(&ipc->tx_queue)) { bfd->when &= ~BSC_FD_WRITE; return 0; } lh = ipc->tx_queue.next; llist_del(lh); msg = llist_entry(lh, struct msgb, list); logp_ipbc_uid(DLMI, LOGL_DEBUG, ipbc, bfd->priv_nr >> 8); DEBUGPC(DLMI, "TX %04x: %s\n", bfd->priv_nr, osmo_hexdump(msg->data, msg->len)); ret = send(bfd->fd, msg->data, msg->len, 0); msgb_free(msg); if (ret == 0) { logp_ipbc_uid(DLINP, LOGL_NOTICE, ipbc, bfd->priv_nr >> 8); LOGP(DLINP, LOGL_NOTICE, "%s disappeared, dead socket\n", btsbsc); handle_dead_socket(bfd); } return ret; } /* callback from select.c in case one of the fd's can be read/written */ static int proxy_ipaccess_fd_cb(struct osmo_fd *bfd, unsigned int what) { int rc = 0; if (what & BSC_FD_READ) { rc = handle_tcp_read(bfd); if (rc < 0) return rc; } if (what & BSC_FD_WRITE) rc = handle_tcp_write(bfd); return rc; } /* callback of the listening filedescriptor */ static int listen_fd_cb(struct osmo_fd *listen_bfd, unsigned int what) { int ret; struct ipa_proxy_conn *ipc; struct osmo_fd *bfd; struct sockaddr_in sa; socklen_t sa_len = sizeof(sa); if (!(what & BSC_FD_READ)) return 0; ret = accept(listen_bfd->fd, (struct sockaddr *) &sa, &sa_len); if (ret < 0) { perror("accept"); return ret; } DEBUGP(DLINP, "accept()ed new %s link from %s\n", (listen_bfd->priv_nr & 0xff) == OML_FROM_BTS ? "OML" : "RSL", inet_ntoa(sa.sin_addr)); ipc = alloc_conn(); if (!ipc) { close(ret); return -ENOMEM; } bfd = &ipc->fd; bfd->fd = ret; bfd->data = ipc; bfd->priv_nr = listen_bfd->priv_nr; bfd->cb = proxy_ipaccess_fd_cb; bfd->when = BSC_FD_READ; ret = osmo_fd_register(bfd); if (ret < 0) { LOGP(DLINP, LOGL_ERROR, "could not register FD\n"); close(bfd->fd); talloc_free(ipc); return ret; } /* Request ID. FIXME: request LOCATION, HW/SW VErsion, Unit Name, Serno */ ret = ipa_ccm_send_id_req(bfd->fd); return 0; } static void send_ns(int fd, const char *buf, int size, struct in_addr ip, int port) { int ret; struct sockaddr_in addr; socklen_t len = sizeof(addr); memset(&addr, 0, sizeof(addr)); addr.sin_family = AF_INET; addr.sin_port = htons(port); addr.sin_addr = ip; ret = sendto(fd, buf, size, 0, (struct sockaddr *) &addr, len); if (ret < 0) { LOGP(DLINP, LOGL_ERROR, "Failed to forward GPRS message.\n"); } } static int gprs_ns_cb(struct osmo_fd *bfd, unsigned int what) { struct ipa_bts_conn *bts; char buf[4096]; int ret; struct sockaddr_in sock; socklen_t len = sizeof(sock); /* 1. get the data... */ ret = recvfrom(bfd->fd, buf, sizeof(buf), 0, (struct sockaddr *) &sock, &len); if (ret < 0) { LOGP(DLINP, LOGL_ERROR, "Failed to recv GPRS NS msg: %s.\n", strerror(errno)); return -1; } bts = bfd->data; /* 2. figure out where to send it to */ if (memcmp(&sock.sin_addr, &ipp->gprs_addr, sizeof(sock.sin_addr)) == 0) { LOGP(DLINP, LOGL_DEBUG, "GPRS NS msg from network.\n"); send_ns(bfd->fd, buf, ret, bts->bts_addr, 23000); } else if (memcmp(&sock.sin_addr, &bts->bts_addr, sizeof(sock.sin_addr)) == 0) { LOGP(DLINP, LOGL_DEBUG, "GPRS NS msg from BTS.\n"); send_ns(bfd->fd, buf, ret, ipp->gprs_addr, 23000); } else { LOGP(DLINP, LOGL_ERROR, "Unknown GPRS source: %s\n", inet_ntoa(sock.sin_addr)); } return 0; } /* Actively connect to a BSC. */ static struct ipa_proxy_conn *connect_bsc(struct sockaddr_in *sa, int priv_nr, void *data) { struct ipa_proxy_conn *ipc; struct osmo_fd *bfd; int ret, on = 1; ipc = alloc_conn(); if (!ipc) return NULL; ipc->bts_conn = data; bfd = &ipc->fd; bfd->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); bfd->cb = ipaccess_fd_cb; bfd->when = BSC_FD_READ | BSC_FD_WRITE; bfd->data = ipc; bfd->priv_nr = priv_nr; if (bfd->fd < 0) { LOGP(DLINP, LOGL_ERROR, "Could not create socket: %s\n", strerror(errno)); talloc_free(ipc); return NULL; } ret = setsockopt(bfd->fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); if (ret < 0) { LOGP(DLINP, LOGL_ERROR, "Could not set socket option\n"); close(bfd->fd); talloc_free(ipc); return NULL; } ret = connect(bfd->fd, (struct sockaddr *) sa, sizeof(*sa)); if (ret < 0) { LOGP(DLINP, LOGL_ERROR, "Could not connect socket: %s\n", inet_ntoa(sa->sin_addr)); close(bfd->fd); talloc_free(ipc); return NULL; } /* pre-fill tx_queue with identity request */ ret = osmo_fd_register(bfd); if (ret < 0) { close(bfd->fd); talloc_free(ipc); return NULL; } return ipc; } static int ipaccess_proxy_setup(void) { int ret; ipp = talloc_zero(tall_bsc_ctx, struct ipa_proxy); if (!ipp) return -ENOMEM; INIT_LLIST_HEAD(&ipp->bts_list); osmo_timer_setup(&ipp->reconn_timer, reconn_tmr_cb, ipp); /* Listen for OML connections */ ipp->oml_listen_fd.priv_nr = OML_FROM_BTS; ipp->oml_listen_fd.cb = listen_fd_cb; ret = osmo_sock_init_ofd(&ipp->oml_listen_fd, AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, IPA_TCP_PORT_OML, OSMO_SOCK_F_BIND); if (ret < 0) return ret; /* Listen for RSL connections */ ipp->rsl_listen_fd.priv_nr = RSL_FROM_BTS; ipp->rsl_listen_fd.cb = listen_fd_cb; ret = osmo_sock_init_ofd(&ipp->rsl_listen_fd, AF_INET, SOCK_STREAM, IPPROTO_TCP, NULL, IPA_TCP_PORT_RSL, OSMO_SOCK_F_BIND); if (ret < 0) return ret; /* Connect the GPRS NS Socket */ if (gprs_ns_ipaddr) { inet_aton(gprs_ns_ipaddr, &ipp->gprs_addr); inet_aton(listen_ipaddr, &ipp->listen_addr); } return ret; } static void signal_handler(int signal) { fprintf(stdout, "signal %u received\n", signal); switch (signal) { case SIGABRT: /* in case of abort, we want to obtain a talloc report * and then return to the caller, who will abort the process */ case SIGUSR1: talloc_report_full(tall_bsc_ctx, stderr); break; default: break; } } static void print_help(void) { printf(" ipaccess-proxy is a proxy BTS.\n"); printf(" -h --help. This help text.\n"); printf(" -l --listen IP. The ip to listen to.\n"); printf(" -b --bsc IP. The BSC IP address.\n"); printf(" -g --gprs IP. Take GPRS NS from that IP.\n"); printf("\n"); printf(" -s --disable-color. Disable the color inside the logging message.\n"); printf(" -e --log-level number. Set the global loglevel.\n"); printf(" -T --timestamp. Prefix every log message with a timestamp.\n"); printf(" -V --version. Print the version of OpenBSC.\n"); } static void print_usage(void) { printf("Usage: ipaccess-proxy [options]\n"); } enum { IPA_PROXY_OPT_LISTEN_NONE = 0, IPA_PROXY_OPT_LISTEN_IP = (1 << 0), IPA_PROXY_OPT_BSC_IP = (1 << 1), }; static void handle_options(int argc, char** argv) { int options_mask = 0; /* disable explicit missing arguments error output from getopt_long */ opterr = 0; while (1) { int option_index = 0, c; static struct option long_options[] = { {"help", 0, 0, 'h'}, {"disable-color", 0, 0, 's'}, {"timestamp", 0, 0, 'T'}, {"log-level", 1, 0, 'e'}, {"listen", 1, 0, 'l'}, {"bsc", 1, 0, 'b'}, {0, 0, 0, 0} }; c = getopt_long(argc, argv, "hsTe:l:b:g:", long_options, &option_index); if (c == -1) break; switch (c) { case 'h': print_usage(); print_help(); exit(0); case 'l': listen_ipaddr = optarg; options_mask |= IPA_PROXY_OPT_LISTEN_IP; break; case 'b': bsc_ipaddr = optarg; options_mask |= IPA_PROXY_OPT_BSC_IP; break; case 'g': gprs_ns_ipaddr = optarg; break; case 's': log_set_use_color(osmo_stderr_target, 0); break; case 'T': log_set_print_timestamp(osmo_stderr_target, 1); break; case 'e': log_set_log_level(osmo_stderr_target, atoi(optarg)); break; case '?': if (optopt) { printf("ERROR: missing mandatory argument " "for `%s' option\n", argv[optind-1]); } else { printf("ERROR: unknown option `%s'\n", argv[optind-1]); } print_usage(); print_help(); exit(EXIT_FAILURE); break; default: /* ignore */ break; } } if ((options_mask & (IPA_PROXY_OPT_LISTEN_IP | IPA_PROXY_OPT_BSC_IP)) != (IPA_PROXY_OPT_LISTEN_IP | IPA_PROXY_OPT_BSC_IP)) { printf("ERROR: You have to specify `--listen' and `--bsc' " "options at least.\n"); print_usage(); print_help(); exit(EXIT_FAILURE); } } static const struct log_info_cat log_categories[] = { [DMM] = { .name = "DMM", .description = "Layer3 Mobility Management (MM)", .color = "\033[1;33m", .enabled = 1, .loglevel = LOGL_NOTICE, }, }; const struct log_info log_info = { .cat = log_categories, .num_cat = ARRAY_SIZE(log_categories), }; int main(int argc, char **argv) { int rc; tall_bsc_ctx = talloc_named_const(NULL, 1, "ipaccess-proxy"); msgb_talloc_ctx_init(tall_bsc_ctx, 0); osmo_init_logging2(tall_bsc_ctx, &log_info); log_parse_category_mask(osmo_stderr_target, "DLINP:DLMI"); handle_options(argc, argv); rc = ipaccess_proxy_setup(); if (rc < 0) exit(1); signal(SIGUSR1, &signal_handler); signal(SIGABRT, &signal_handler); osmo_init_ignore_signals(); while (1) { osmo_select_main(0); } }