Pablo Neira Ayuso | 0ba77d5 | 2011-06-05 18:32:44 +0200 | [diff] [blame^] | 1 | /* OpenBSC Abis input driver for HSL Femto */ |
| 2 | |
| 3 | /* (C) 2011 by Harald Welte <laforge@gnumonks.org> |
| 4 | * (C) 2011 by On-Waves |
| 5 | * |
| 6 | * All Rights Reserved |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU Affero General Public License as published by |
| 10 | * the Free Software Foundation; either version 3 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU Affero General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Affero General Public License |
| 19 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 20 | * |
| 21 | */ |
| 22 | |
| 23 | /* HSL uses a much more primitive/simplified version of the IPA multiplex. |
| 24 | * |
| 25 | * They have taken out the nice parts like the ID_GET / ID_RESP for resolving |
| 26 | * the UNIT ID, as well as the keepalive ping/pong messages. Furthermore, the |
| 27 | * Stream Identifiers are fixed on the BTS side (RSL always 0, OML always 0xff) |
| 28 | * and both OML+RSL share a single TCP connection. |
| 29 | * |
| 30 | * Other oddities include the encapsulation of BSSGP messages in the L3_INFO IE |
| 31 | * of RSL |
| 32 | */ |
| 33 | |
| 34 | #include "internal.h" |
| 35 | |
| 36 | #include <stdio.h> |
| 37 | #include <unistd.h> |
| 38 | #include <stdlib.h> |
| 39 | #include <errno.h> |
| 40 | #include <string.h> |
| 41 | #include <time.h> |
| 42 | #include <sys/fcntl.h> |
| 43 | #include <sys/socket.h> |
| 44 | #include <sys/ioctl.h> |
| 45 | #include <arpa/inet.h> |
| 46 | |
| 47 | #include <osmocom/core/select.h> |
| 48 | #include <osmocom/gsm/tlv.h> |
| 49 | #include <osmocom/core/msgb.h> |
| 50 | #include <osmocom/gsm/abis/e1_input.h> |
| 51 | #include <osmocom/core/logging.h> |
| 52 | #include <osmocom/gsm/protocol/ipaccess.h> |
| 53 | /*#include <openbsc/debug.h> |
| 54 | #include <openbsc/gsm_data.h> |
| 55 | #include <openbsc/abis_nm.h> |
| 56 | #include <openbsc/abis_rsl.h> |
| 57 | #include <openbsc/subchan_demux.h> |
| 58 | #include <openbsc/e1_input.h> |
| 59 | #include <openbsc/ipaccess.h> |
| 60 | #include <openbsc/socket.h> |
| 61 | #include <openbsc/signal.h> */ |
| 62 | #include <talloc.h> |
| 63 | |
| 64 | #define HSL_TCP_PORT 2500 |
| 65 | #define HSL_PROTO_DEBUG 0xdd |
| 66 | |
| 67 | #define PRIV_OML 1 |
| 68 | #define PRIV_RSL 2 |
| 69 | |
| 70 | static void *tall_bsc_ctx; |
| 71 | |
| 72 | /* data structure for one E1 interface with A-bis */ |
| 73 | struct hsl_e1_handle { |
| 74 | struct osmo_fd listen_fd; |
| 75 | struct gsm_network *gsmnet; |
| 76 | }; |
| 77 | |
| 78 | static struct hsl_e1_handle *e1h; |
| 79 | |
| 80 | |
| 81 | #define TS1_ALLOC_SIZE 900 |
| 82 | |
| 83 | static int handle_ts1_read(struct osmo_fd *bfd) |
| 84 | { |
| 85 | struct e1inp_line *line = bfd->data; |
| 86 | unsigned int ts_nr = bfd->priv_nr; |
| 87 | struct e1inp_ts *e1i_ts = &line->ts[ts_nr-1]; |
| 88 | struct msgb *msg; |
| 89 | int ret = 0, error; |
| 90 | |
| 91 | msg = ipaccess_read_msg(bfd, &error); |
| 92 | if (!msg) { |
| 93 | if (e1i_ts->line->rx_err) |
| 94 | e1i_ts->line->rx_err(error); |
| 95 | if (error == 0) { |
| 96 | osmo_fd_unregister(bfd); |
| 97 | close(bfd->fd); |
| 98 | bfd->fd = -1; |
| 99 | } |
| 100 | return error; |
| 101 | } |
| 102 | DEBUGP(DMI, "RX %u: %s\n", ts_nr, osmo_hexdump(msgb_l2(msg), msgb_l2len(msg))); |
| 103 | |
| 104 | /* XXX better use e1inp_rx_ts. */ |
| 105 | if (e1i_ts->line->rx) |
| 106 | e1i_ts->line->rx(msg, e1i_ts); |
| 107 | |
| 108 | return ret; |
| 109 | } |
| 110 | |
| 111 | static int ts_want_write(struct e1inp_ts *e1i_ts) |
| 112 | { |
| 113 | e1i_ts->driver.ipaccess.fd.when |= BSC_FD_WRITE; |
| 114 | |
| 115 | return 0; |
| 116 | } |
| 117 | |
| 118 | static void timeout_ts1_write(void *data) |
| 119 | { |
| 120 | struct e1inp_ts *e1i_ts = (struct e1inp_ts *)data; |
| 121 | |
| 122 | /* trigger write of ts1, due to tx delay timer */ |
| 123 | ts_want_write(e1i_ts); |
| 124 | } |
| 125 | |
| 126 | static int handle_ts1_write(struct osmo_fd *bfd) |
| 127 | { |
| 128 | struct e1inp_line *line = bfd->data; |
| 129 | unsigned int ts_nr = bfd->priv_nr; |
| 130 | struct e1inp_ts *e1i_ts = &line->ts[ts_nr-1]; |
| 131 | struct e1inp_sign_link *sign_link; |
| 132 | struct msgb *msg; |
| 133 | uint8_t proto; |
| 134 | int ret; |
| 135 | |
| 136 | bfd->when &= ~BSC_FD_WRITE; |
| 137 | |
| 138 | /* get the next msg for this timeslot */ |
| 139 | msg = e1inp_tx_ts(e1i_ts, &sign_link); |
| 140 | if (!msg) { |
| 141 | /* no message after tx delay timer */ |
| 142 | return 0; |
| 143 | } |
| 144 | |
| 145 | switch (sign_link->type) { |
| 146 | case E1INP_SIGN_OML: |
| 147 | proto = IPAC_PROTO_OML; |
| 148 | #ifdef HSL_SR_1_0 |
| 149 | /* HSL uses 0x81 for FOM for some reason */ |
| 150 | if (msg->data[0] == ABIS_OM_MDISC_FOM) |
| 151 | msg->data[0] = ABIS_OM_MDISC_FOM | 0x01; |
| 152 | #endif |
| 153 | break; |
| 154 | case E1INP_SIGN_RSL: |
| 155 | proto = IPAC_PROTO_RSL; |
| 156 | break; |
| 157 | default: |
| 158 | msgb_free(msg); |
| 159 | bfd->when |= BSC_FD_WRITE; /* come back for more msg */ |
| 160 | return -EINVAL; |
| 161 | } |
| 162 | |
| 163 | msg->l2h = msg->data; |
| 164 | ipaccess_prepend_header(msg, sign_link->tei); |
| 165 | |
| 166 | DEBUGP(DMI, "TX %u: %s\n", ts_nr, osmo_hexdump(msg->l2h, msgb_l2len(msg))); |
| 167 | |
| 168 | ret = send(bfd->fd, msg->data, msg->len, 0); |
| 169 | msgb_free(msg); |
| 170 | |
| 171 | /* set tx delay timer for next event */ |
| 172 | e1i_ts->sign.tx_timer.cb = timeout_ts1_write; |
| 173 | e1i_ts->sign.tx_timer.data = e1i_ts; |
| 174 | |
| 175 | /* Reducing this might break the nanoBTS 900 init. */ |
| 176 | osmo_timer_schedule(&e1i_ts->sign.tx_timer, 0, e1i_ts->sign.delay); |
| 177 | |
| 178 | return ret; |
| 179 | } |
| 180 | |
| 181 | /* callback from select.c in case one of the fd's can be read/written */ |
| 182 | static int hsl_fd_cb(struct osmo_fd *bfd, unsigned int what) |
| 183 | { |
| 184 | struct e1inp_line *line = bfd->data; |
| 185 | unsigned int ts_nr = bfd->priv_nr; |
| 186 | unsigned int idx = ts_nr-1; |
| 187 | struct e1inp_ts *e1i_ts; |
| 188 | int rc = 0; |
| 189 | |
| 190 | /* In case of early RSL we might not yet have a line */ |
| 191 | |
| 192 | if (line) |
| 193 | e1i_ts = &line->ts[idx]; |
| 194 | |
| 195 | if (!line || e1i_ts->type == E1INP_TS_TYPE_SIGN) { |
| 196 | if (what & BSC_FD_READ) |
| 197 | rc = handle_ts1_read(bfd); |
| 198 | if (what & BSC_FD_WRITE) |
| 199 | rc = handle_ts1_write(bfd); |
| 200 | } else |
| 201 | LOGP(DINP, LOGL_ERROR, "unknown E1 TS type %u\n", e1i_ts->type); |
| 202 | |
| 203 | return rc; |
| 204 | } |
| 205 | |
| 206 | static int hsl_line_update(struct e1inp_line *line, enum e1inp_line_role role); |
| 207 | |
| 208 | struct e1inp_driver hsl_driver = { |
| 209 | .name = "hsl", |
| 210 | .want_write = ts_want_write, |
| 211 | .line_update = hsl_line_update, |
| 212 | .default_delay = 0, |
| 213 | }; |
| 214 | |
| 215 | /* callback of the OML listening filedescriptor */ |
| 216 | static int listen_fd_cb(struct osmo_fd *listen_bfd, unsigned int what) |
| 217 | { |
| 218 | int ret; |
| 219 | int idx = 0; |
| 220 | int i; |
| 221 | struct e1inp_line *line = listen_bfd->data; |
| 222 | struct e1inp_ts *e1i_ts; |
| 223 | struct osmo_fd *bfd; |
| 224 | struct sockaddr_in sa; |
| 225 | socklen_t sa_len = sizeof(sa); |
| 226 | |
| 227 | if (!(what & BSC_FD_READ)) |
| 228 | return 0; |
| 229 | |
| 230 | ret = accept(listen_bfd->fd, (struct sockaddr *) &sa, &sa_len); |
| 231 | if (ret < 0) { |
| 232 | perror("accept"); |
| 233 | return ret; |
| 234 | } |
| 235 | LOGP(DINP, LOGL_NOTICE, "accept()ed new HSL link from %s\n", |
| 236 | inet_ntoa(sa.sin_addr)); |
| 237 | |
| 238 | /* create virrtual E1 timeslots for signalling */ |
| 239 | e1inp_ts_config_sign(&line->ts[1-1], line); |
| 240 | |
| 241 | /* initialize the fds */ |
| 242 | for (i = 0; i < ARRAY_SIZE(line->ts); ++i) |
| 243 | line->ts[i].driver.ipaccess.fd.fd = -1; |
| 244 | |
| 245 | e1i_ts = &line->ts[idx]; |
| 246 | |
| 247 | bfd = &e1i_ts->driver.ipaccess.fd; |
| 248 | bfd->fd = ret; |
| 249 | bfd->data = line; |
| 250 | bfd->priv_nr = PRIV_OML; |
| 251 | bfd->cb = hsl_fd_cb; |
| 252 | bfd->when = BSC_FD_READ; |
| 253 | ret = osmo_fd_register(bfd); |
| 254 | if (ret < 0) { |
| 255 | LOGP(DINP, LOGL_ERROR, "could not register FD\n"); |
| 256 | close(bfd->fd); |
| 257 | talloc_free(line); |
| 258 | return ret; |
| 259 | } |
| 260 | |
| 261 | return ret; |
| 262 | } |
| 263 | |
| 264 | static int |
| 265 | hsl_line_update(struct e1inp_line *line, enum e1inp_line_role role) |
| 266 | { |
| 267 | int ret = -ENOENT; |
| 268 | |
| 269 | switch(role) { |
| 270 | case E1INP_LINE_R_BSC: |
| 271 | ret = make_sock(&e1h->listen_fd, IPPROTO_TCP, INADDR_ANY, |
| 272 | HSL_TCP_PORT, 0, listen_fd_cb, line); |
| 273 | break; |
| 274 | case E1INP_LINE_R_BTS: |
| 275 | /* XXX: not implemented yet. */ |
| 276 | break; |
| 277 | default: |
| 278 | break; |
| 279 | } |
| 280 | return ret; |
| 281 | } |
| 282 | |
| 283 | int hsl_setup(struct gsm_network *gsmnet) |
| 284 | { |
| 285 | e1h->gsmnet = gsmnet; |
| 286 | return 0; |
| 287 | } |
| 288 | |
| 289 | void e1inp_hsl_init(void) |
| 290 | { |
| 291 | e1h = talloc_zero(tall_bsc_ctx, struct hsl_e1_handle); |
| 292 | if (!e1h) |
| 293 | return; |
| 294 | |
| 295 | e1inp_driver_register(&hsl_driver); |
| 296 | } |