Holger Hans Peter Freyther | 97f66e2 | 2010-07-28 03:32:52 +0800 | [diff] [blame] | 1 | /* Implementation of the C7 UDP link */ |
| 2 | /* |
| 3 | * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org> |
| 4 | * (C) 2010 by On-Waves |
| 5 | * All Rights Reserved |
| 6 | * |
Holger Hans Peter Freyther | de56c22 | 2011-01-16 17:45:14 +0100 | [diff] [blame] | 7 | * This program is free software: you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU Affero General Public License as published by |
| 9 | * the Free Software Foundation, either version 3 of the License, or |
Holger Hans Peter Freyther | 97f66e2 | 2010-07-28 03:32:52 +0800 | [diff] [blame] | 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
Holger Hans Peter Freyther | de56c22 | 2011-01-16 17:45:14 +0100 | [diff] [blame] | 15 | * GNU Affero General Public License for more details. |
Holger Hans Peter Freyther | 97f66e2 | 2010-07-28 03:32:52 +0800 | [diff] [blame] | 16 | * |
Holger Hans Peter Freyther | de56c22 | 2011-01-16 17:45:14 +0100 | [diff] [blame] | 17 | * You should have received a copy of the GNU Affero General Public License |
| 18 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
Holger Hans Peter Freyther | 97f66e2 | 2010-07-28 03:32:52 +0800 | [diff] [blame] | 19 | * |
| 20 | */ |
| 21 | |
| 22 | #include <bsc_data.h> |
| 23 | #include <udp_input.h> |
| 24 | #include <mtp_data.h> |
| 25 | #include <mtp_pcap.h> |
| 26 | #include <snmp_mtp.h> |
Holger Hans Peter Freyther | cbf7d18 | 2010-07-31 05:25:35 +0800 | [diff] [blame] | 27 | #include <cellmgr_debug.h> |
Holger Hans Peter Freyther | 97f66e2 | 2010-07-28 03:32:52 +0800 | [diff] [blame] | 28 | |
Holger Hans Peter Freyther | cbf7d18 | 2010-07-31 05:25:35 +0800 | [diff] [blame] | 29 | #include <osmocore/talloc.h> |
Holger Hans Peter Freyther | 97f66e2 | 2010-07-28 03:32:52 +0800 | [diff] [blame] | 30 | |
| 31 | #include <sys/socket.h> |
| 32 | #include <netinet/in.h> |
| 33 | #include <arpa/inet.h> |
| 34 | |
| 35 | #include <string.h> |
| 36 | #include <unistd.h> |
| 37 | |
| 38 | static int udp_write_cb(struct bsc_fd *fd, struct msgb *msg) |
| 39 | { |
| 40 | struct link_data *link; |
| 41 | int rc; |
| 42 | |
| 43 | link = (struct link_data *) fd->data; |
| 44 | |
| 45 | LOGP(DINP, LOGL_DEBUG, "Sending MSU: %s\n", hexdump(msg->data, msg->len)); |
| 46 | if (link->pcap_fd >= 0) |
| 47 | mtp_pcap_write_msu(link->pcap_fd, msg->l2h, msgb_l2len(msg)); |
| 48 | |
| 49 | /* the assumption is we have connected the socket to the remote */ |
| 50 | rc = sendto(fd->fd, msg->data, msg->len, 0, |
| 51 | (struct sockaddr *) &link->udp.remote, sizeof(link->udp.remote)); |
| 52 | if (rc != msg->len) { |
| 53 | LOGP(DINP, LOGL_ERROR, "Failed to write msg to socket: %d\n", rc); |
| 54 | return -1; |
| 55 | } |
| 56 | |
| 57 | return 0; |
| 58 | } |
| 59 | |
| 60 | static int udp_read_cb(struct bsc_fd *fd) |
| 61 | { |
| 62 | struct link_data *link; |
| 63 | struct udp_data_hdr *hdr; |
| 64 | struct msgb *msg; |
| 65 | int rc; |
| 66 | unsigned int length; |
| 67 | |
| 68 | msg = msgb_alloc_headroom(4096, 128, "UDP datagram"); |
| 69 | if (!msg) { |
| 70 | LOGP(DINP, LOGL_ERROR, "Failed to allocate memory.\n"); |
| 71 | return -1; |
| 72 | } |
| 73 | |
| 74 | |
| 75 | link = (struct link_data *) fd->data; |
| 76 | rc = read(fd->fd, msg->data, 2096); |
| 77 | if (rc < sizeof(*hdr)) { |
| 78 | LOGP(DINP, LOGL_ERROR, "Failed to read at least size of the header: %d\n", rc); |
| 79 | rc = -1; |
| 80 | goto exit; |
| 81 | } |
| 82 | |
| 83 | /* throw away data as the link is down */ |
| 84 | if (link->the_link->available == 0) { |
| 85 | LOGP(DINP, LOGL_ERROR, "The link is down. Not forwarding.\n"); |
| 86 | rc = 0; |
| 87 | goto exit; |
| 88 | } |
| 89 | |
| 90 | hdr = (struct udp_data_hdr *) msgb_put(msg, sizeof(*hdr)); |
| 91 | |
| 92 | if (hdr->data_type == UDP_DATA_RETR_COMPL || hdr->data_type == UDP_DATA_RETR_IMPOS) { |
| 93 | LOGP(DINP, LOGL_ERROR, "Link retrieval done. Restarting the link.\n"); |
Holger Hans Peter Freyther | c840569 | 2011-01-02 20:24:08 +0100 | [diff] [blame] | 94 | mtp_link_down(link); |
| 95 | mtp_link_up(link); |
Holger Hans Peter Freyther | 97f66e2 | 2010-07-28 03:32:52 +0800 | [diff] [blame] | 96 | goto exit; |
| 97 | } else if (hdr->data_type > UDP_DATA_MSU_PRIO_3) { |
| 98 | LOGP(DINP, LOGL_ERROR, "Link failure. retrieved message.\n"); |
Holger Hans Peter Freyther | c840569 | 2011-01-02 20:24:08 +0100 | [diff] [blame] | 99 | mtp_link_down(link); |
Holger Hans Peter Freyther | 97f66e2 | 2010-07-28 03:32:52 +0800 | [diff] [blame] | 100 | goto exit; |
| 101 | } |
| 102 | |
| 103 | length = ntohl(hdr->data_length); |
| 104 | if (length + sizeof(*hdr) > (unsigned int) rc) { |
| 105 | LOGP(DINP, LOGL_ERROR, "The MSU payload does not fit: %u + %u > %d \n", |
| 106 | length, sizeof(*hdr), rc); |
| 107 | rc = -1; |
| 108 | goto exit; |
| 109 | } |
| 110 | |
| 111 | msg->l2h = msgb_put(msg, length); |
| 112 | |
| 113 | LOGP(DINP, LOGL_DEBUG, "MSU data on: %p data %s.\n", link, hexdump(msg->data, msg->len)); |
| 114 | if (link->pcap_fd >= 0) |
| 115 | mtp_pcap_write_msu(link->pcap_fd, msg->l2h, msgb_l2len(msg)); |
Holger Hans Peter Freyther | 569f1e1 | 2011-01-02 18:47:49 +0100 | [diff] [blame] | 116 | mtp_link_set_data(link->the_link, msg); |
Holger Hans Peter Freyther | 97f66e2 | 2010-07-28 03:32:52 +0800 | [diff] [blame] | 117 | |
| 118 | exit: |
| 119 | msgb_free(msg); |
| 120 | return rc; |
| 121 | } |
| 122 | |
| 123 | static int udp_link_dummy(struct link_data *link) |
| 124 | { |
| 125 | /* nothing todo */ |
| 126 | return 0; |
| 127 | } |
| 128 | |
| 129 | static void do_start(void *_data) |
| 130 | { |
| 131 | struct link_data *link = (struct link_data *) _data; |
| 132 | |
Holger Hans Peter Freyther | b6edf97 | 2011-01-02 16:41:11 +0100 | [diff] [blame] | 133 | snmp_mtp_activate(link->udp.session, link->udp.link_index); |
Holger Hans Peter Freyther | c840569 | 2011-01-02 20:24:08 +0100 | [diff] [blame] | 134 | mtp_link_up(link); |
Holger Hans Peter Freyther | 97f66e2 | 2010-07-28 03:32:52 +0800 | [diff] [blame] | 135 | } |
| 136 | |
| 137 | static int udp_link_reset(struct link_data *link) |
| 138 | { |
| 139 | LOGP(DINP, LOGL_NOTICE, "Will restart SLTM transmission in %d seconds.\n", |
| 140 | link->udp.reset_timeout); |
Holger Hans Peter Freyther | b6edf97 | 2011-01-02 16:41:11 +0100 | [diff] [blame] | 141 | snmp_mtp_deactivate(link->udp.session, link->udp.link_index); |
Holger Hans Peter Freyther | c840569 | 2011-01-02 20:24:08 +0100 | [diff] [blame] | 142 | mtp_link_down(link); |
Holger Hans Peter Freyther | 97f66e2 | 2010-07-28 03:32:52 +0800 | [diff] [blame] | 143 | |
| 144 | /* restart the link in 90 seconds... to force a timeout on the BSC */ |
| 145 | link->link_activate.cb = do_start; |
| 146 | link->link_activate.data = link; |
| 147 | bsc_schedule_timer(&link->link_activate, link->udp.reset_timeout, 0); |
| 148 | return 0; |
| 149 | } |
| 150 | |
| 151 | static int udp_link_write(struct link_data *link, struct msgb *msg) |
| 152 | { |
| 153 | struct udp_data_hdr *hdr; |
| 154 | |
| 155 | hdr = (struct udp_data_hdr *) msgb_push(msg, sizeof(*hdr)); |
| 156 | hdr->format_type = UDP_FORMAT_SIMPLE_UDP; |
| 157 | hdr->data_type = UDP_DATA_MSU_PRIO_0; |
Holger Hans Peter Freyther | b6edf97 | 2011-01-02 16:41:11 +0100 | [diff] [blame] | 158 | hdr->data_link_index = htons(link->udp.link_index); |
Holger Hans Peter Freyther | 97f66e2 | 2010-07-28 03:32:52 +0800 | [diff] [blame] | 159 | hdr->user_context = 0; |
| 160 | hdr->data_length = htonl(msgb_l2len(msg)); |
| 161 | |
| 162 | if (write_queue_enqueue(&link->udp.write_queue, msg) != 0) { |
| 163 | LOGP(DINP, LOGL_ERROR, "Failed to enqueue msg.\n"); |
| 164 | msgb_free(msg); |
| 165 | return -1; |
| 166 | } |
| 167 | |
| 168 | return 0; |
| 169 | } |
| 170 | |
| 171 | static int udp_link_start(struct link_data *link) |
| 172 | { |
| 173 | LOGP(DINP, LOGL_NOTICE, "UDP input is ready.\n"); |
| 174 | do_start(link); |
| 175 | return 0; |
| 176 | } |
| 177 | |
| 178 | int link_udp_init(struct link_data *link, int src_port, const char *remote, int remote_port) |
| 179 | { |
| 180 | struct sockaddr_in addr; |
| 181 | int fd; |
| 182 | int on; |
| 183 | |
| 184 | write_queue_init(&link->udp.write_queue, 100); |
| 185 | |
| 186 | /* function table */ |
| 187 | link->shutdown = udp_link_dummy; |
| 188 | link->clear_queue = udp_link_dummy; |
| 189 | |
| 190 | link->reset = udp_link_reset; |
| 191 | link->start = udp_link_start; |
| 192 | link->write = udp_link_write; |
| 193 | |
| 194 | /* socket creation */ |
| 195 | link->udp.write_queue.bfd.data = link; |
| 196 | link->udp.write_queue.bfd.when = BSC_FD_READ; |
| 197 | link->udp.write_queue.read_cb = udp_read_cb; |
| 198 | link->udp.write_queue.write_cb = udp_write_cb; |
| 199 | |
| 200 | link->udp.write_queue.bfd.fd = fd = socket(AF_INET, SOCK_DGRAM, 0); |
| 201 | if (fd < 0) { |
| 202 | LOGP(DINP, LOGL_ERROR, "Failed to create UDP socket.\n"); |
| 203 | return -1; |
| 204 | } |
| 205 | |
| 206 | on = 1; |
| 207 | setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)); |
| 208 | |
| 209 | memset(&addr, 0, sizeof(addr)); |
| 210 | addr.sin_family = AF_INET; |
| 211 | addr.sin_port = htons(src_port); |
| 212 | addr.sin_addr.s_addr = INADDR_ANY; |
| 213 | |
| 214 | if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) { |
| 215 | perror("Failed to bind UDP socket"); |
| 216 | close(fd); |
| 217 | return -1; |
| 218 | } |
| 219 | |
| 220 | /* now connect the socket to the remote */ |
| 221 | memset(&link->udp.remote, 0, sizeof(link->udp.remote)); |
| 222 | link->udp.remote.sin_family = AF_INET; |
| 223 | link->udp.remote.sin_port = htons(remote_port); |
| 224 | inet_aton(remote, &link->udp.remote.sin_addr); |
| 225 | |
| 226 | if (bsc_register_fd(&link->udp.write_queue.bfd) != 0) { |
| 227 | LOGP(DINP, LOGL_ERROR, "Failed to register BFD.\n"); |
| 228 | close(fd); |
| 229 | return -1; |
| 230 | } |
| 231 | |
| 232 | return 0; |
| 233 | } |