osdl.org!shemminger | aba5acd | 2004-04-15 20:56:59 +0000 | [diff] [blame] | 1 | /* |
| 2 | * libnetlink.c RTnetlink service routines. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version |
| 7 | * 2 of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include <stdio.h> |
| 14 | #include <stdlib.h> |
| 15 | #include <unistd.h> |
| 16 | #include <syslog.h> |
| 17 | #include <fcntl.h> |
| 18 | #include <net/if_arp.h> |
| 19 | #include <sys/socket.h> |
| 20 | #include <netinet/in.h> |
| 21 | #include <string.h> |
| 22 | #include <errno.h> |
| 23 | #include <time.h> |
| 24 | #include <sys/uio.h> |
| 25 | |
| 26 | #include "libnetlink.h" |
| 27 | |
| 28 | void rtnl_close(struct rtnl_handle *rth) |
| 29 | { |
| 30 | close(rth->fd); |
| 31 | } |
| 32 | |
| 33 | int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions) |
| 34 | { |
| 35 | int addr_len; |
| 36 | |
| 37 | memset(rth, 0, sizeof(rth)); |
| 38 | |
| 39 | rth->fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); |
| 40 | if (rth->fd < 0) { |
| 41 | perror("Cannot open netlink socket"); |
| 42 | return -1; |
| 43 | } |
| 44 | |
| 45 | memset(&rth->local, 0, sizeof(rth->local)); |
| 46 | rth->local.nl_family = AF_NETLINK; |
| 47 | rth->local.nl_groups = subscriptions; |
| 48 | |
| 49 | if (bind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local)) < 0) { |
| 50 | perror("Cannot bind netlink socket"); |
| 51 | return -1; |
| 52 | } |
| 53 | addr_len = sizeof(rth->local); |
| 54 | if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0) { |
| 55 | perror("Cannot getsockname"); |
| 56 | return -1; |
| 57 | } |
| 58 | if (addr_len != sizeof(rth->local)) { |
| 59 | fprintf(stderr, "Wrong address length %d\n", addr_len); |
| 60 | return -1; |
| 61 | } |
| 62 | if (rth->local.nl_family != AF_NETLINK) { |
| 63 | fprintf(stderr, "Wrong address family %d\n", rth->local.nl_family); |
| 64 | return -1; |
| 65 | } |
| 66 | rth->seq = time(NULL); |
| 67 | return 0; |
| 68 | } |
| 69 | |
| 70 | int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type) |
| 71 | { |
| 72 | struct { |
| 73 | struct nlmsghdr nlh; |
| 74 | struct rtgenmsg g; |
| 75 | } req; |
| 76 | struct sockaddr_nl nladdr; |
| 77 | |
| 78 | memset(&nladdr, 0, sizeof(nladdr)); |
| 79 | nladdr.nl_family = AF_NETLINK; |
| 80 | |
| 81 | req.nlh.nlmsg_len = sizeof(req); |
| 82 | req.nlh.nlmsg_type = type; |
| 83 | req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST; |
| 84 | req.nlh.nlmsg_pid = 0; |
| 85 | req.nlh.nlmsg_seq = rth->dump = ++rth->seq; |
| 86 | req.g.rtgen_family = family; |
| 87 | |
| 88 | return sendto(rth->fd, (void*)&req, sizeof(req), 0, (struct sockaddr*)&nladdr, sizeof(nladdr)); |
| 89 | } |
| 90 | |
| 91 | int rtnl_send(struct rtnl_handle *rth, char *buf, int len) |
| 92 | { |
| 93 | struct sockaddr_nl nladdr; |
| 94 | |
| 95 | memset(&nladdr, 0, sizeof(nladdr)); |
| 96 | nladdr.nl_family = AF_NETLINK; |
| 97 | |
| 98 | return sendto(rth->fd, buf, len, 0, (struct sockaddr*)&nladdr, sizeof(nladdr)); |
| 99 | } |
| 100 | |
| 101 | int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len) |
| 102 | { |
| 103 | struct nlmsghdr nlh; |
| 104 | struct sockaddr_nl nladdr; |
| 105 | struct iovec iov[2] = { { &nlh, sizeof(nlh) }, { req, len } }; |
| 106 | struct msghdr msg = { |
| 107 | (void*)&nladdr, sizeof(nladdr), |
| 108 | iov, 2, |
| 109 | NULL, 0, |
| 110 | 0 |
| 111 | }; |
| 112 | |
| 113 | memset(&nladdr, 0, sizeof(nladdr)); |
| 114 | nladdr.nl_family = AF_NETLINK; |
| 115 | |
| 116 | nlh.nlmsg_len = NLMSG_LENGTH(len); |
| 117 | nlh.nlmsg_type = type; |
| 118 | nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST; |
| 119 | nlh.nlmsg_pid = 0; |
| 120 | nlh.nlmsg_seq = rth->dump = ++rth->seq; |
| 121 | |
| 122 | return sendmsg(rth->fd, &msg, 0); |
| 123 | } |
| 124 | |
| 125 | int rtnl_dump_filter(struct rtnl_handle *rth, |
| 126 | int (*filter)(struct sockaddr_nl *, struct nlmsghdr *n, void *), |
| 127 | void *arg1, |
| 128 | int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *), |
| 129 | void *arg2) |
| 130 | { |
| 131 | char buf[8192]; |
| 132 | struct sockaddr_nl nladdr; |
| 133 | struct iovec iov = { buf, sizeof(buf) }; |
| 134 | |
| 135 | while (1) { |
| 136 | int status; |
| 137 | struct nlmsghdr *h; |
| 138 | |
| 139 | struct msghdr msg = { |
| 140 | (void*)&nladdr, sizeof(nladdr), |
| 141 | &iov, 1, |
| 142 | NULL, 0, |
| 143 | 0 |
| 144 | }; |
| 145 | |
| 146 | status = recvmsg(rth->fd, &msg, 0); |
| 147 | |
| 148 | if (status < 0) { |
| 149 | if (errno == EINTR) |
| 150 | continue; |
| 151 | perror("OVERRUN"); |
| 152 | continue; |
| 153 | } |
| 154 | if (status == 0) { |
| 155 | fprintf(stderr, "EOF on netlink\n"); |
| 156 | return -1; |
| 157 | } |
| 158 | if (msg.msg_namelen != sizeof(nladdr)) { |
| 159 | fprintf(stderr, "sender address length == %d\n", msg.msg_namelen); |
| 160 | exit(1); |
| 161 | } |
| 162 | |
| 163 | h = (struct nlmsghdr*)buf; |
| 164 | while (NLMSG_OK(h, status)) { |
| 165 | int err; |
| 166 | |
| 167 | if (h->nlmsg_pid != rth->local.nl_pid || |
| 168 | h->nlmsg_seq != rth->dump) { |
| 169 | if (junk) { |
| 170 | err = junk(&nladdr, h, arg2); |
| 171 | if (err < 0) |
| 172 | return err; |
| 173 | } |
| 174 | goto skip_it; |
| 175 | } |
| 176 | |
| 177 | if (h->nlmsg_type == NLMSG_DONE) |
| 178 | return 0; |
| 179 | if (h->nlmsg_type == NLMSG_ERROR) { |
| 180 | struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h); |
| 181 | if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) { |
| 182 | fprintf(stderr, "ERROR truncated\n"); |
| 183 | } else { |
| 184 | errno = -err->error; |
| 185 | perror("RTNETLINK answers"); |
| 186 | } |
| 187 | return -1; |
| 188 | } |
| 189 | err = filter(&nladdr, h, arg1); |
| 190 | if (err < 0) |
| 191 | return err; |
| 192 | |
| 193 | skip_it: |
| 194 | h = NLMSG_NEXT(h, status); |
| 195 | } |
| 196 | if (msg.msg_flags & MSG_TRUNC) { |
| 197 | fprintf(stderr, "Message truncated\n"); |
| 198 | continue; |
| 199 | } |
| 200 | if (status) { |
| 201 | fprintf(stderr, "!!!Remnant of size %d\n", status); |
| 202 | exit(1); |
| 203 | } |
| 204 | } |
| 205 | } |
| 206 | |
| 207 | int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer, |
| 208 | unsigned groups, struct nlmsghdr *answer, |
| 209 | int (*junk)(struct sockaddr_nl *,struct nlmsghdr *n, void *), |
| 210 | void *jarg) |
| 211 | { |
| 212 | int status; |
| 213 | unsigned seq; |
| 214 | struct nlmsghdr *h; |
| 215 | struct sockaddr_nl nladdr; |
| 216 | struct iovec iov = { (void*)n, n->nlmsg_len }; |
| 217 | char buf[8192]; |
| 218 | struct msghdr msg = { |
| 219 | (void*)&nladdr, sizeof(nladdr), |
| 220 | &iov, 1, |
| 221 | NULL, 0, |
| 222 | 0 |
| 223 | }; |
| 224 | |
| 225 | memset(&nladdr, 0, sizeof(nladdr)); |
| 226 | nladdr.nl_family = AF_NETLINK; |
| 227 | nladdr.nl_pid = peer; |
| 228 | nladdr.nl_groups = groups; |
| 229 | |
| 230 | n->nlmsg_seq = seq = ++rtnl->seq; |
| 231 | if (answer == NULL) |
| 232 | n->nlmsg_flags |= NLM_F_ACK; |
| 233 | |
| 234 | status = sendmsg(rtnl->fd, &msg, 0); |
| 235 | |
| 236 | if (status < 0) { |
| 237 | perror("Cannot talk to rtnetlink"); |
| 238 | return -1; |
| 239 | } |
| 240 | |
| 241 | iov.iov_base = buf; |
| 242 | |
| 243 | while (1) { |
| 244 | iov.iov_len = sizeof(buf); |
| 245 | status = recvmsg(rtnl->fd, &msg, 0); |
| 246 | |
| 247 | if (status < 0) { |
| 248 | if (errno == EINTR) |
| 249 | continue; |
| 250 | perror("OVERRUN"); |
| 251 | continue; |
| 252 | } |
| 253 | if (status == 0) { |
| 254 | fprintf(stderr, "EOF on netlink\n"); |
| 255 | return -1; |
| 256 | } |
| 257 | if (msg.msg_namelen != sizeof(nladdr)) { |
| 258 | fprintf(stderr, "sender address length == %d\n", msg.msg_namelen); |
| 259 | exit(1); |
| 260 | } |
| 261 | for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) { |
| 262 | int err; |
| 263 | int len = h->nlmsg_len; |
| 264 | int l = len - sizeof(*h); |
| 265 | |
| 266 | if (l<0 || len>status) { |
| 267 | if (msg.msg_flags & MSG_TRUNC) { |
| 268 | fprintf(stderr, "Truncated message\n"); |
| 269 | return -1; |
| 270 | } |
| 271 | fprintf(stderr, "!!!malformed message: len=%d\n", len); |
| 272 | exit(1); |
| 273 | } |
| 274 | |
| 275 | if (h->nlmsg_pid != rtnl->local.nl_pid || |
| 276 | h->nlmsg_seq != seq) { |
| 277 | if (junk) { |
| 278 | err = junk(&nladdr, h, jarg); |
| 279 | if (err < 0) |
| 280 | return err; |
| 281 | } |
| 282 | continue; |
| 283 | } |
| 284 | |
| 285 | if (h->nlmsg_type == NLMSG_ERROR) { |
| 286 | struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h); |
| 287 | if (l < sizeof(struct nlmsgerr)) { |
| 288 | fprintf(stderr, "ERROR truncated\n"); |
| 289 | } else { |
| 290 | errno = -err->error; |
| 291 | if (errno == 0) { |
| 292 | if (answer) |
| 293 | memcpy(answer, h, h->nlmsg_len); |
| 294 | return 0; |
| 295 | } |
| 296 | perror("RTNETLINK answers"); |
| 297 | } |
| 298 | return -1; |
| 299 | } |
| 300 | if (answer) { |
| 301 | memcpy(answer, h, h->nlmsg_len); |
| 302 | return 0; |
| 303 | } |
| 304 | |
| 305 | fprintf(stderr, "Unexpected reply!!!\n"); |
| 306 | |
| 307 | status -= NLMSG_ALIGN(len); |
| 308 | h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len)); |
| 309 | } |
| 310 | if (msg.msg_flags & MSG_TRUNC) { |
| 311 | fprintf(stderr, "Message truncated\n"); |
| 312 | continue; |
| 313 | } |
| 314 | if (status) { |
| 315 | fprintf(stderr, "!!!Remnant of size %d\n", status); |
| 316 | exit(1); |
| 317 | } |
| 318 | } |
| 319 | } |
| 320 | |
| 321 | int rtnl_listen(struct rtnl_handle *rtnl, |
| 322 | int (*handler)(struct sockaddr_nl *,struct nlmsghdr *n, void *), |
| 323 | void *jarg) |
| 324 | { |
| 325 | int status; |
| 326 | struct nlmsghdr *h; |
| 327 | struct sockaddr_nl nladdr; |
| 328 | struct iovec iov; |
| 329 | char buf[8192]; |
| 330 | struct msghdr msg = { |
| 331 | (void*)&nladdr, sizeof(nladdr), |
| 332 | &iov, 1, |
| 333 | NULL, 0, |
| 334 | 0 |
| 335 | }; |
| 336 | |
| 337 | memset(&nladdr, 0, sizeof(nladdr)); |
| 338 | nladdr.nl_family = AF_NETLINK; |
| 339 | nladdr.nl_pid = 0; |
| 340 | nladdr.nl_groups = 0; |
| 341 | |
| 342 | |
| 343 | iov.iov_base = buf; |
| 344 | |
| 345 | while (1) { |
| 346 | iov.iov_len = sizeof(buf); |
| 347 | status = recvmsg(rtnl->fd, &msg, 0); |
| 348 | |
| 349 | if (status < 0) { |
| 350 | if (errno == EINTR) |
| 351 | continue; |
| 352 | perror("OVERRUN"); |
| 353 | continue; |
| 354 | } |
| 355 | if (status == 0) { |
| 356 | fprintf(stderr, "EOF on netlink\n"); |
| 357 | return -1; |
| 358 | } |
| 359 | if (msg.msg_namelen != sizeof(nladdr)) { |
| 360 | fprintf(stderr, "Sender address length == %d\n", msg.msg_namelen); |
| 361 | exit(1); |
| 362 | } |
| 363 | for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) { |
| 364 | int err; |
| 365 | int len = h->nlmsg_len; |
| 366 | int l = len - sizeof(*h); |
| 367 | |
| 368 | if (l<0 || len>status) { |
| 369 | if (msg.msg_flags & MSG_TRUNC) { |
| 370 | fprintf(stderr, "Truncated message\n"); |
| 371 | return -1; |
| 372 | } |
| 373 | fprintf(stderr, "!!!malformed message: len=%d\n", len); |
| 374 | exit(1); |
| 375 | } |
| 376 | |
| 377 | err = handler(&nladdr, h, jarg); |
| 378 | if (err < 0) |
| 379 | return err; |
| 380 | |
| 381 | status -= NLMSG_ALIGN(len); |
| 382 | h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len)); |
| 383 | } |
| 384 | if (msg.msg_flags & MSG_TRUNC) { |
| 385 | fprintf(stderr, "Message truncated\n"); |
| 386 | continue; |
| 387 | } |
| 388 | if (status) { |
| 389 | fprintf(stderr, "!!!Remnant of size %d\n", status); |
| 390 | exit(1); |
| 391 | } |
| 392 | } |
| 393 | } |
| 394 | |
| 395 | int rtnl_from_file(FILE *rtnl, |
| 396 | int (*handler)(struct sockaddr_nl *,struct nlmsghdr *n, void *), |
| 397 | void *jarg) |
| 398 | { |
| 399 | int status; |
| 400 | struct sockaddr_nl nladdr; |
| 401 | char buf[8192]; |
| 402 | struct nlmsghdr *h = (void*)buf; |
| 403 | |
| 404 | memset(&nladdr, 0, sizeof(nladdr)); |
| 405 | nladdr.nl_family = AF_NETLINK; |
| 406 | nladdr.nl_pid = 0; |
| 407 | nladdr.nl_groups = 0; |
| 408 | |
| 409 | while (1) { |
| 410 | int err, len, type; |
| 411 | int l; |
| 412 | |
| 413 | status = fread(&buf, 1, sizeof(*h), rtnl); |
| 414 | |
| 415 | if (status < 0) { |
| 416 | if (errno == EINTR) |
| 417 | continue; |
| 418 | perror("rtnl_from_file: fread"); |
| 419 | return -1; |
| 420 | } |
| 421 | if (status == 0) |
| 422 | return 0; |
| 423 | |
| 424 | len = h->nlmsg_len; |
| 425 | type= h->nlmsg_type; |
| 426 | l = len - sizeof(*h); |
| 427 | |
| 428 | if (l<0 || len>sizeof(buf)) { |
| 429 | fprintf(stderr, "!!!malformed message: len=%d @%lu\n", |
| 430 | len, ftell(rtnl)); |
| 431 | return -1; |
| 432 | } |
| 433 | |
| 434 | status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl); |
| 435 | |
| 436 | if (status < 0) { |
| 437 | perror("rtnl_from_file: fread"); |
| 438 | return -1; |
| 439 | } |
| 440 | if (status < l) { |
| 441 | fprintf(stderr, "rtnl-from_file: truncated message\n"); |
| 442 | return -1; |
| 443 | } |
| 444 | |
| 445 | err = handler(&nladdr, h, jarg); |
| 446 | if (err < 0) |
| 447 | return err; |
| 448 | } |
| 449 | } |
| 450 | |
| 451 | int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data) |
| 452 | { |
| 453 | int len = RTA_LENGTH(4); |
| 454 | struct rtattr *rta; |
| 455 | if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) |
| 456 | return -1; |
| 457 | rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len)); |
| 458 | rta->rta_type = type; |
| 459 | rta->rta_len = len; |
| 460 | memcpy(RTA_DATA(rta), &data, 4); |
| 461 | n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len; |
| 462 | return 0; |
| 463 | } |
| 464 | |
| 465 | int addattr_l(struct nlmsghdr *n, int maxlen, int type, void *data, int alen) |
| 466 | { |
| 467 | int len = RTA_LENGTH(alen); |
| 468 | struct rtattr *rta; |
| 469 | |
| 470 | if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) |
| 471 | return -1; |
| 472 | rta = (struct rtattr*)(((char*)n) + NLMSG_ALIGN(n->nlmsg_len)); |
| 473 | rta->rta_type = type; |
| 474 | rta->rta_len = len; |
| 475 | memcpy(RTA_DATA(rta), data, alen); |
| 476 | n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len; |
| 477 | return 0; |
| 478 | } |
| 479 | |
| 480 | int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data) |
| 481 | { |
| 482 | int len = RTA_LENGTH(4); |
| 483 | struct rtattr *subrta; |
| 484 | |
| 485 | if (RTA_ALIGN(rta->rta_len) + len > maxlen) |
| 486 | return -1; |
| 487 | subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len)); |
| 488 | subrta->rta_type = type; |
| 489 | subrta->rta_len = len; |
| 490 | memcpy(RTA_DATA(subrta), &data, 4); |
| 491 | rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len; |
| 492 | return 0; |
| 493 | } |
| 494 | |
| 495 | int rta_addattr_l(struct rtattr *rta, int maxlen, int type, void *data, int alen) |
| 496 | { |
| 497 | struct rtattr *subrta; |
| 498 | int len = RTA_LENGTH(alen); |
| 499 | |
| 500 | if (RTA_ALIGN(rta->rta_len) + len > maxlen) |
| 501 | return -1; |
| 502 | subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len)); |
| 503 | subrta->rta_type = type; |
| 504 | subrta->rta_len = len; |
| 505 | memcpy(RTA_DATA(subrta), data, alen); |
| 506 | rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len; |
| 507 | return 0; |
| 508 | } |
| 509 | |
| 510 | |
| 511 | int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len) |
| 512 | { |
| 513 | while (RTA_OK(rta, len)) { |
| 514 | if (rta->rta_type <= max) |
| 515 | tb[rta->rta_type] = rta; |
| 516 | rta = RTA_NEXT(rta,len); |
| 517 | } |
| 518 | if (len) |
| 519 | fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len); |
| 520 | return 0; |
| 521 | } |