Holger Hans Peter Freyther | 465313e | 2010-06-15 18:49:53 +0800 | [diff] [blame] | 1 | /* |
| 2 | * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org> |
| 3 | * (C) 2010 by On-Waves |
| 4 | * All Rights Reserved |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License as published by |
| 8 | * the Free Software Foundation; either version 2 of the License, or |
| 9 | * (at your option) any later version. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | * GNU General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License along |
| 17 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 18 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 19 | * |
| 20 | */ |
| 21 | |
| 22 | #include <openbsc/bsc_nat.h> |
| 23 | #include <openbsc/gsm_data.h> |
| 24 | #include <openbsc/bssap.h> |
| 25 | #include <openbsc/debug.h> |
Holger Hans Peter Freyther | 241e130 | 2010-03-31 09:16:56 +0200 | [diff] [blame] | 26 | #include <openbsc/mgcp.h> |
| 27 | #include <openbsc/mgcp_internal.h> |
Holger Hans Peter Freyther | 465313e | 2010-06-15 18:49:53 +0800 | [diff] [blame] | 28 | |
| 29 | #include <netinet/in.h> |
| 30 | #include <arpa/inet.h> |
| 31 | |
Holger Hans Peter Freyther | a7f8018 | 2010-03-31 13:02:22 +0200 | [diff] [blame] | 32 | #include <errno.h> |
| 33 | #include <unistd.h> |
| 34 | |
Holger Hans Peter Freyther | 465313e | 2010-06-15 18:49:53 +0800 | [diff] [blame] | 35 | int bsc_mgcp_assign(struct sccp_connections *con, struct msgb *msg) |
| 36 | { |
| 37 | struct tlv_parsed tp; |
| 38 | u_int16_t cic; |
| 39 | u_int8_t timeslot; |
| 40 | u_int8_t multiplex; |
| 41 | |
| 42 | if (!msg->l3h) { |
| 43 | LOGP(DNAT, LOGL_ERROR, "Assignment message should have l3h pointer.\n"); |
| 44 | return -1; |
| 45 | } |
| 46 | |
| 47 | if (msgb_l3len(msg) < 3) { |
| 48 | LOGP(DNAT, LOGL_ERROR, "Assignment message has not enough space for GSM0808.\n"); |
| 49 | return -1; |
| 50 | } |
| 51 | |
| 52 | tlv_parse(&tp, gsm0808_att_tlvdef(), msg->l3h + 3, msgb_l3len(msg) - 3, 0, 0); |
| 53 | if (!TLVP_PRESENT(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE)) { |
| 54 | LOGP(DNAT, LOGL_ERROR, "Circuit identity code not found in assignment message.\n"); |
| 55 | return -1; |
| 56 | } |
| 57 | |
| 58 | cic = ntohs(*(u_int16_t *)TLVP_VAL(&tp, GSM0808_IE_CIRCUIT_IDENTITY_CODE)); |
| 59 | timeslot = cic & 0x1f; |
| 60 | multiplex = (cic & ~0x1f) >> 5; |
| 61 | |
| 62 | con->msc_timeslot = (32 * multiplex) + timeslot; |
| 63 | con->bsc_timeslot = con->msc_timeslot; |
| 64 | return 0; |
| 65 | } |
| 66 | |
| 67 | void bsc_mgcp_clear(struct sccp_connections *con) |
| 68 | { |
| 69 | con->msc_timeslot = -1; |
| 70 | con->bsc_timeslot = -1; |
| 71 | } |
Holger Hans Peter Freyther | 241e130 | 2010-03-31 09:16:56 +0200 | [diff] [blame] | 72 | |
| 73 | void bsc_mgcp_free_endpoints(struct bsc_nat *nat) |
| 74 | { |
| 75 | int i; |
| 76 | |
| 77 | for (i = 1; i < nat->mgcp_cfg->number_endpoints; ++i) |
| 78 | mgcp_free_endp(&nat->mgcp_cfg->endpoints[i]); |
| 79 | } |
Holger Hans Peter Freyther | a7f8018 | 2010-03-31 13:02:22 +0200 | [diff] [blame] | 80 | |
Holger Hans Peter Freyther | fc9bd23 | 2010-04-01 03:55:27 +0200 | [diff] [blame] | 81 | struct bsc_connection *bsc_mgcp_find_con(struct bsc_nat *nat, int endpoint) |
| 82 | { |
| 83 | struct sccp_connections *sccp; |
| 84 | |
| 85 | llist_for_each_entry(sccp, &nat->sccp_connections, list_entry) { |
| 86 | if (sccp->msc_timeslot == -1) |
| 87 | continue; |
| 88 | if (mgcp_timeslot_to_endpoint(0, sccp->msc_timeslot) != endpoint) |
| 89 | continue; |
| 90 | |
| 91 | return sccp->bsc; |
| 92 | } |
| 93 | |
| 94 | LOGP(DMGCP, LOGL_ERROR, "Failed to find the connection.\n"); |
| 95 | return NULL; |
| 96 | } |
| 97 | |
Holger Hans Peter Freyther | 76c8354 | 2010-04-01 06:48:52 +0200 | [diff] [blame^] | 98 | /* we need to replace some strings... */ |
| 99 | struct msgb *bsc_mgcp_rewrite(struct msgb *input, const char *ip, int port) |
| 100 | { |
| 101 | static const char *ip_str = "c=IN IP4 "; |
| 102 | static const char *aud_str = "m=audio "; |
| 103 | |
| 104 | char buf[128]; |
| 105 | char *running, *token; |
| 106 | struct msgb *output; |
| 107 | |
| 108 | if (msgb_l2len(input) > 4096 - 128) { |
| 109 | LOGP(DMGCP, LOGL_ERROR, "Input is too long.\n"); |
| 110 | return NULL; |
| 111 | } |
| 112 | |
| 113 | output = msgb_alloc_headroom(4096, 128, "MGCP rewritten"); |
| 114 | if (!output) { |
| 115 | LOGP(DMGCP, LOGL_ERROR, "Failed to allocate new MGCP msg.\n"); |
| 116 | return NULL; |
| 117 | } |
| 118 | |
| 119 | running = (char *) input->l2h; |
| 120 | output->l2h = output->data; |
| 121 | for (token = strsep(&running, "\n"); token; token = strsep(&running, "\n")) { |
| 122 | int len = strlen(token); |
| 123 | |
| 124 | /* ignore completely empty lines for now */ |
| 125 | if (len == 0) |
| 126 | continue; |
| 127 | |
| 128 | if (strncmp(ip_str, token, (sizeof ip_str) - 1) == 0) { |
| 129 | output->l3h = msgb_put(output, strlen(ip_str)); |
| 130 | memcpy(output->l3h, ip_str, strlen(ip_str)); |
| 131 | output->l3h = msgb_put(output, strlen(ip)); |
| 132 | memcpy(output->l3h, ip, strlen(ip)); |
| 133 | output->l3h = msgb_put(output, 2); |
| 134 | output->l3h[0] = '\r'; |
| 135 | output->l3h[1] = '\n'; |
| 136 | } else if (strncmp(aud_str, token, (sizeof aud_str) - 1) == 0) { |
| 137 | int payload; |
| 138 | if (sscanf(token, "m=audio %*d RTP/AVP %d", &payload) != 1) { |
| 139 | LOGP(DMGCP, LOGL_ERROR, "Could not parsed audio line.\n"); |
| 140 | msgb_free(output); |
| 141 | return NULL; |
| 142 | } |
| 143 | |
| 144 | snprintf(buf, sizeof(buf)-1, "m=audio %d RTP/AVP %d\r\n", port, payload); |
| 145 | buf[sizeof(buf)-1] = '\0'; |
| 146 | |
| 147 | output->l3h = msgb_put(output, strlen(buf)); |
| 148 | memcpy(output->l3h, buf, strlen(buf)); |
| 149 | } else { |
| 150 | output->l3h = msgb_put(output, len + 1); |
| 151 | memcpy(output->l3h, token, len); |
| 152 | output->l3h[len] = '\n'; |
| 153 | } |
| 154 | } |
| 155 | |
| 156 | return output; |
| 157 | } |
| 158 | |
Holger Hans Peter Freyther | a7f8018 | 2010-03-31 13:02:22 +0200 | [diff] [blame] | 159 | static int mgcp_do_read(struct bsc_fd *fd) |
| 160 | { |
| 161 | struct bsc_nat *nat; |
| 162 | struct msgb *msg, *resp; |
| 163 | int rc; |
| 164 | |
| 165 | msg = msgb_alloc(4096, "MGCP GW Read"); |
| 166 | if (!msg) { |
| 167 | LOGP(DMGCP, LOGL_ERROR, "Failed to create buffer.\n"); |
| 168 | return -1; |
| 169 | } |
| 170 | |
| 171 | |
| 172 | rc = read(fd->fd, msg->data, msg->data_len); |
| 173 | if (rc <= 0) { |
| 174 | LOGP(DMGCP, LOGL_ERROR, "Failed to read errno: %d\n", errno); |
| 175 | msgb_free(msg); |
| 176 | return -1; |
| 177 | } |
| 178 | |
| 179 | nat = fd->data; |
| 180 | msg->l2h = msgb_put(msg, rc); |
| 181 | resp = mgcp_handle_message(nat->mgcp_cfg, msg); |
| 182 | msgb_free(msg); |
| 183 | |
| 184 | /* we do have a direct answer... e.g. AUEP */ |
| 185 | if (resp) { |
| 186 | if (write_queue_enqueue(&nat->mgcp_queue, resp) != 0) { |
| 187 | LOGP(DMGCP, LOGL_ERROR, "Failed to enqueue msg.\n"); |
| 188 | msgb_free(resp); |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | return 0; |
| 193 | } |
| 194 | |
| 195 | static int mgcp_do_write(struct bsc_fd *bfd, struct msgb *msg) |
| 196 | { |
| 197 | int rc; |
| 198 | |
| 199 | rc = write(bfd->fd, msg->data, msg->len); |
| 200 | |
| 201 | if (rc != msg->len) { |
| 202 | LOGP(DMGCP, LOGL_ERROR, "Failed to write msg to MGCP CallAgent.\n"); |
| 203 | return -1; |
| 204 | } |
| 205 | |
| 206 | return rc; |
| 207 | } |
| 208 | |
| 209 | int bsc_mgcp_init(struct bsc_nat *nat) |
| 210 | { |
| 211 | int on; |
| 212 | struct sockaddr_in addr; |
| 213 | |
| 214 | if (!nat->mgcp_cfg->call_agent_addr) { |
| 215 | LOGP(DMGCP, LOGL_ERROR, "The BSC nat requires the call agent ip to be set.\n"); |
| 216 | return -1; |
| 217 | } |
| 218 | |
| 219 | nat->mgcp_queue.bfd.fd = socket(AF_INET, SOCK_DGRAM, 0); |
| 220 | if (nat->mgcp_queue.bfd.fd < 0) { |
| 221 | LOGP(DMGCP, LOGL_ERROR, "Failed to create MGCP socket. errno: %d\n", errno); |
| 222 | return -1; |
| 223 | } |
| 224 | |
| 225 | on = 1; |
| 226 | setsockopt(nat->mgcp_queue.bfd.fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); |
| 227 | |
| 228 | addr.sin_family = AF_INET; |
| 229 | addr.sin_port = htons(nat->mgcp_cfg->source_port); |
| 230 | inet_aton(nat->mgcp_cfg->source_addr, &addr.sin_addr); |
| 231 | |
| 232 | if (bind(nat->mgcp_queue.bfd.fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { |
| 233 | LOGP(DMGCP, LOGL_ERROR, "Failed to bind. errno: %d\n", errno); |
| 234 | close(nat->mgcp_queue.bfd.fd); |
| 235 | nat->mgcp_queue.bfd.fd = -1; |
| 236 | return -1; |
| 237 | } |
| 238 | |
| 239 | addr.sin_port = htons(2727); |
| 240 | inet_aton(nat->mgcp_cfg->call_agent_addr, &addr.sin_addr); |
| 241 | if (connect(nat->mgcp_queue.bfd.fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { |
| 242 | LOGP(DMGCP, LOGL_ERROR, "Failed to connect to: '%s'. errno: %d\n", |
| 243 | nat->mgcp_cfg->call_agent_addr, errno); |
| 244 | close(nat->mgcp_queue.bfd.fd); |
| 245 | nat->mgcp_queue.bfd.fd = -1; |
| 246 | return -1; |
| 247 | } |
| 248 | |
| 249 | write_queue_init(&nat->mgcp_queue, 10); |
| 250 | nat->mgcp_queue.bfd.when = BSC_FD_READ; |
| 251 | nat->mgcp_queue.bfd.data = nat; |
| 252 | nat->mgcp_queue.read_cb = mgcp_do_read; |
| 253 | nat->mgcp_queue.write_cb = mgcp_do_write; |
| 254 | |
| 255 | if (bsc_register_fd(&nat->mgcp_queue.bfd) != 0) { |
| 256 | LOGP(DMGCP, LOGL_ERROR, "Failed to register MGCP fd.\n"); |
| 257 | close(nat->mgcp_queue.bfd.fd); |
| 258 | nat->mgcp_queue.bfd.fd = -1; |
| 259 | return -1; |
| 260 | } |
| 261 | |
| 262 | return 0; |
| 263 | } |