Harald Welte | e779c36 | 2010-06-29 20:51:13 +0200 | [diff] [blame] | 1 | /* GSMTAP output for Osmocom Layer2 (will only work on the host PC) */ |
| 2 | /* |
| 3 | * (C) 2010 by Harald Welte <laforge@gnumonks.org> |
| 4 | * |
| 5 | * All Rights Reserved |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 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 |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License along |
| 18 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 19 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | */ |
| 22 | |
| 23 | #include "../config.h" |
| 24 | |
| 25 | #ifdef HAVE_SYS_SELECT_H |
| 26 | |
Pablo Neira Ayuso | 8341934 | 2011-03-22 16:36:13 +0100 | [diff] [blame] | 27 | #include <osmocom/core/gsmtap_util.h> |
| 28 | #include <osmocom/core/logging.h> |
| 29 | #include <osmocom/core/gsmtap.h> |
| 30 | #include <osmocom/core/msgb.h> |
| 31 | #include <osmocom/core/select.h> |
| 32 | #include <osmocom/gsm/protocol/gsm_04_08.h> |
| 33 | #include <osmocom/gsm/rsl.h> |
Harald Welte | e779c36 | 2010-06-29 20:51:13 +0200 | [diff] [blame] | 34 | |
| 35 | #include <arpa/inet.h> |
| 36 | #include <sys/socket.h> |
| 37 | #include <netinet/in.h> |
| 38 | |
| 39 | #include <stdio.h> |
| 40 | #include <unistd.h> |
| 41 | #include <stdint.h> |
| 42 | #include <string.h> |
| 43 | #include <errno.h> |
| 44 | |
Pablo Neira Ayuso | f7f89d0 | 2011-05-07 12:42:40 +0200 | [diff] [blame] | 45 | static struct osmo_fd gsmtap_bfd = { .fd = -1 }; |
| 46 | static struct osmo_fd gsmtap_sink_bfd = { .fd = -1 }; |
Harald Welte | e779c36 | 2010-06-29 20:51:13 +0200 | [diff] [blame] | 47 | static LLIST_HEAD(gsmtap_txqueue); |
| 48 | |
| 49 | uint8_t chantype_rsl2gsmtap(uint8_t rsl_chantype, uint8_t link_id) |
| 50 | { |
| 51 | uint8_t ret = GSMTAP_CHANNEL_UNKNOWN; |
| 52 | |
| 53 | switch (rsl_chantype) { |
| 54 | case RSL_CHAN_Bm_ACCHs: |
| 55 | ret = GSMTAP_CHANNEL_TCH_F; |
| 56 | break; |
| 57 | case RSL_CHAN_Lm_ACCHs: |
| 58 | ret = GSMTAP_CHANNEL_TCH_H; |
| 59 | break; |
| 60 | case RSL_CHAN_SDCCH4_ACCH: |
| 61 | ret = GSMTAP_CHANNEL_SDCCH4; |
| 62 | break; |
| 63 | case RSL_CHAN_SDCCH8_ACCH: |
| 64 | ret = GSMTAP_CHANNEL_SDCCH8; |
| 65 | break; |
| 66 | case RSL_CHAN_BCCH: |
| 67 | ret = GSMTAP_CHANNEL_BCCH; |
| 68 | break; |
| 69 | case RSL_CHAN_RACH: |
| 70 | ret = GSMTAP_CHANNEL_RACH; |
| 71 | break; |
| 72 | case RSL_CHAN_PCH_AGCH: |
| 73 | /* it could also be AGCH... */ |
| 74 | ret = GSMTAP_CHANNEL_PCH; |
| 75 | break; |
| 76 | } |
| 77 | |
| 78 | if (link_id & 0x40) |
| 79 | ret |= GSMTAP_CHANNEL_ACCH; |
| 80 | |
| 81 | return ret; |
| 82 | } |
| 83 | |
| 84 | /* receive a message from L1/L2 and put it in GSMTAP */ |
Harald Welte | e34a940 | 2010-06-29 22:31:21 +0200 | [diff] [blame] | 85 | struct msgb *gsmtap_makemsg(uint16_t arfcn, uint8_t ts, uint8_t chan_type, |
| 86 | uint8_t ss, uint32_t fn, int8_t signal_dbm, |
| 87 | uint8_t snr, const uint8_t *data, unsigned int len) |
Harald Welte | e779c36 | 2010-06-29 20:51:13 +0200 | [diff] [blame] | 88 | { |
| 89 | struct msgb *msg; |
| 90 | struct gsmtap_hdr *gh; |
| 91 | uint8_t *dst; |
| 92 | |
Harald Welte | e779c36 | 2010-06-29 20:51:13 +0200 | [diff] [blame] | 93 | msg = msgb_alloc(sizeof(*gh) + len, "gsmtap_tx"); |
| 94 | if (!msg) |
Harald Welte | e34a940 | 2010-06-29 22:31:21 +0200 | [diff] [blame] | 95 | return NULL; |
Harald Welte | e779c36 | 2010-06-29 20:51:13 +0200 | [diff] [blame] | 96 | |
| 97 | gh = (struct gsmtap_hdr *) msgb_put(msg, sizeof(*gh)); |
| 98 | |
| 99 | gh->version = GSMTAP_VERSION; |
| 100 | gh->hdr_len = sizeof(*gh)/4; |
| 101 | gh->type = GSMTAP_TYPE_UM; |
| 102 | gh->timeslot = ts; |
| 103 | gh->sub_slot = ss; |
| 104 | gh->arfcn = htons(arfcn); |
| 105 | gh->snr_db = snr; |
| 106 | gh->signal_dbm = signal_dbm; |
| 107 | gh->frame_number = htonl(fn); |
| 108 | gh->sub_type = chan_type; |
| 109 | gh->antenna_nr = 0; |
| 110 | |
| 111 | dst = msgb_put(msg, len); |
| 112 | memcpy(dst, data, len); |
| 113 | |
Harald Welte | e34a940 | 2010-06-29 22:31:21 +0200 | [diff] [blame] | 114 | return msg; |
| 115 | } |
| 116 | |
| 117 | /* receive a message from L1/L2 and put it in GSMTAP */ |
| 118 | int gsmtap_sendmsg(uint16_t arfcn, uint8_t ts, uint8_t chan_type, uint8_t ss, |
| 119 | uint32_t fn, int8_t signal_dbm, uint8_t snr, |
| 120 | const uint8_t *data, unsigned int len) |
| 121 | { |
| 122 | struct msgb *msg; |
| 123 | |
| 124 | /* gsmtap was never initialized, so don't try to send anything */ |
| 125 | if (gsmtap_bfd.fd == -1) |
| 126 | return 0; |
| 127 | |
| 128 | msg = gsmtap_makemsg(arfcn, ts, chan_type, ss, fn, signal_dbm, |
| 129 | snr, data, len); |
| 130 | if (!msg) |
| 131 | return -ENOMEM; |
| 132 | |
Harald Welte | e779c36 | 2010-06-29 20:51:13 +0200 | [diff] [blame] | 133 | msgb_enqueue(&gsmtap_txqueue, msg); |
| 134 | gsmtap_bfd.when |= BSC_FD_WRITE; |
| 135 | |
| 136 | return 0; |
| 137 | } |
| 138 | |
| 139 | /* Callback from select layer if we can write to the socket */ |
Pablo Neira Ayuso | f7f89d0 | 2011-05-07 12:42:40 +0200 | [diff] [blame] | 140 | static int gsmtap_fd_cb(struct osmo_fd *fd, unsigned int flags) |
Harald Welte | e779c36 | 2010-06-29 20:51:13 +0200 | [diff] [blame] | 141 | { |
| 142 | struct msgb *msg; |
| 143 | int rc; |
| 144 | |
| 145 | if (!(flags & BSC_FD_WRITE)) |
| 146 | return 0; |
| 147 | |
| 148 | msg = msgb_dequeue(&gsmtap_txqueue); |
| 149 | if (!msg) { |
| 150 | /* no more messages in the queue, disable READ cb */ |
| 151 | gsmtap_bfd.when = 0; |
| 152 | return 0; |
| 153 | } |
| 154 | rc = write(gsmtap_bfd.fd, msg->data, msg->len); |
| 155 | if (rc < 0) { |
| 156 | perror("writing msgb to gsmtap fd"); |
| 157 | msgb_free(msg); |
| 158 | return rc; |
| 159 | } |
| 160 | if (rc != msg->len) { |
| 161 | perror("short write to gsmtap fd"); |
| 162 | msgb_free(msg); |
| 163 | return -EIO; |
| 164 | } |
| 165 | |
| 166 | msgb_free(msg); |
| 167 | return 0; |
| 168 | } |
| 169 | |
| 170 | int gsmtap_init(uint32_t dst_ip) |
| 171 | { |
| 172 | int rc; |
| 173 | struct sockaddr_in sin; |
| 174 | |
| 175 | sin.sin_family = AF_INET; |
| 176 | sin.sin_port = htons(GSMTAP_UDP_PORT); |
| 177 | sin.sin_addr.s_addr = htonl(dst_ip); |
| 178 | |
Harald Welte | d58ba46 | 2011-04-27 10:57:49 +0200 | [diff] [blame] | 179 | /* create socket */ |
Harald Welte | e779c36 | 2010-06-29 20:51:13 +0200 | [diff] [blame] | 180 | rc = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); |
| 181 | if (rc < 0) { |
| 182 | perror("creating UDP socket"); |
| 183 | return rc; |
| 184 | } |
| 185 | gsmtap_bfd.fd = rc; |
| 186 | rc = connect(rc, (struct sockaddr *)&sin, sizeof(sin)); |
| 187 | if (rc < 0) { |
| 188 | perror("connecting UDP socket"); |
| 189 | close(gsmtap_bfd.fd); |
Harald Welte | d58ba46 | 2011-04-27 10:57:49 +0200 | [diff] [blame] | 190 | gsmtap_bfd.fd = -1; |
Harald Welte | e779c36 | 2010-06-29 20:51:13 +0200 | [diff] [blame] | 191 | return rc; |
| 192 | } |
| 193 | |
| 194 | gsmtap_bfd.when = BSC_FD_WRITE; |
| 195 | gsmtap_bfd.cb = gsmtap_fd_cb; |
| 196 | gsmtap_bfd.data = NULL; |
| 197 | |
Pablo Neira Ayuso | f7f89d0 | 2011-05-07 12:42:40 +0200 | [diff] [blame] | 198 | return osmo_fd_register(&gsmtap_bfd); |
Harald Welte | e779c36 | 2010-06-29 20:51:13 +0200 | [diff] [blame] | 199 | } |
| 200 | |
Harald Welte | d58ba46 | 2011-04-27 10:57:49 +0200 | [diff] [blame] | 201 | /* Callback from select layer if we can read from the sink socket */ |
Pablo Neira Ayuso | f7f89d0 | 2011-05-07 12:42:40 +0200 | [diff] [blame] | 202 | static int gsmtap_sink_fd_cb(struct osmo_fd *fd, unsigned int flags) |
Harald Welte | d58ba46 | 2011-04-27 10:57:49 +0200 | [diff] [blame] | 203 | { |
| 204 | int rc; |
| 205 | uint8_t buf[4096]; |
| 206 | |
| 207 | if (!(flags & BSC_FD_READ)) |
| 208 | return 0; |
| 209 | |
| 210 | rc = read(fd->fd, buf, sizeof(buf)); |
| 211 | if (rc < 0) { |
| 212 | perror("reading from gsmtap sink fd"); |
| 213 | return rc; |
| 214 | } |
| 215 | /* simply discard any data arriving on the socket */ |
| 216 | |
| 217 | return 0; |
| 218 | } |
| 219 | |
| 220 | /* Create a local 'gsmtap sink' avoiding the UDP packets being rejected |
| 221 | * with ICMP reject messages */ |
| 222 | int gsmtap_sink_init(uint32_t bind_ip) |
| 223 | { |
| 224 | int rc; |
| 225 | struct sockaddr_in sin; |
| 226 | |
| 227 | sin.sin_family = AF_INET; |
| 228 | sin.sin_port = htons(GSMTAP_UDP_PORT); |
| 229 | sin.sin_addr.s_addr = htonl(bind_ip); |
| 230 | |
| 231 | rc = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); |
| 232 | if (rc < 0) { |
| 233 | perror("creating UDP socket"); |
| 234 | return rc; |
| 235 | } |
| 236 | gsmtap_sink_bfd.fd = rc; |
| 237 | rc = bind(rc, (struct sockaddr *)&sin, sizeof(sin)); |
| 238 | if (rc < 0) { |
| 239 | perror("binding UDP socket"); |
| 240 | close(gsmtap_sink_bfd.fd); |
| 241 | gsmtap_sink_bfd.fd = -1; |
| 242 | return rc; |
| 243 | } |
| 244 | |
| 245 | gsmtap_sink_bfd.when = BSC_FD_READ; |
| 246 | gsmtap_sink_bfd.cb = gsmtap_sink_fd_cb; |
| 247 | gsmtap_sink_bfd.data = NULL; |
| 248 | |
Pablo Neira Ayuso | f7f89d0 | 2011-05-07 12:42:40 +0200 | [diff] [blame] | 249 | return osmo_fd_register(&gsmtap_sink_bfd); |
Harald Welte | d58ba46 | 2011-04-27 10:57:49 +0200 | [diff] [blame] | 250 | |
| 251 | } |
| 252 | |
Harald Welte | e779c36 | 2010-06-29 20:51:13 +0200 | [diff] [blame] | 253 | #endif /* HAVE_SYS_SELECT_H */ |