lib/libnetlink.c

   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 <stdbool.h>
  16 #include <unistd.h>
  17 #include <syslog.h>
  18 #include <fcntl.h>
  19 #include <net/if_arp.h>
  20 #include <sys/socket.h>
  21 #include <netinet/in.h>
  22 #include <string.h>
  23 #include <errno.h>
  24 #include <time.h>
  25 #include <sys/uio.h>
  26
  27 #include "libnetlink.h"
  28
  29 #ifndef SOL_NETLINK
  30 #define SOL_NETLINK 270
  31 #endif
  32
  33 #ifndef MIN
  34 #define MIN(a, b) ((a) < (b) ? (a) : (b))
  35 #endif
  36
  37 int rcvbuf = 1024 * 1024;
  38
  39 void rtnl_close(struct rtnl_handle *rth)
  40 {
  41         if (rth->fd >= 0) {
  42                 close(rth->fd);
  43                 rth->fd = -1;
  44         }
  45 }
  46
  47 int rtnl_open_byproto(struct rtnl_handle *rth, unsigned int subscriptions,
  48                       int protocol)
  49 {
  50         socklen_t addr_len;
  51         int sndbuf = 32768;
  52
  53         memset(rth, 0, sizeof(*rth));
  54
  55         rth->proto = protocol;
  56         rth->fd = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, protocol);
  57         if (rth->fd < 0) {
  58                 perror("Cannot open netlink socket");
  59                 return -1;
  60         }
  61
  62         if (setsockopt(rth->fd, SOL_SOCKET, SO_SNDBUF,
  63                        &sndbuf, sizeof(sndbuf)) < 0) {
  64                 perror("SO_SNDBUF");
  65                 return -1;
  66         }
  67
  68         if (setsockopt(rth->fd, SOL_SOCKET, SO_RCVBUF,
  69                        &rcvbuf, sizeof(rcvbuf)) < 0) {
  70                 perror("SO_RCVBUF");
  71                 return -1;
  72         }
  73
  74         memset(&rth->local, 0, sizeof(rth->local));
  75         rth->local.nl_family = AF_NETLINK;
  76         rth->local.nl_groups = subscriptions;
  77
  78         if (bind(rth->fd, (struct sockaddr *)&rth->local,
  79                  sizeof(rth->local)) < 0) {
  80                 perror("Cannot bind netlink socket");
  81                 return -1;
  82         }
  83         addr_len = sizeof(rth->local);
  84         if (getsockname(rth->fd, (struct sockaddr *)&rth->local,
  85                         &addr_len) < 0) {
  86                 perror("Cannot getsockname");
  87                 return -1;
  88         }
  89         if (addr_len != sizeof(rth->local)) {
  90                 fprintf(stderr, "Wrong address length %d\n", addr_len);
  91                 return -1;
  92         }
  93         if (rth->local.nl_family != AF_NETLINK) {
  94                 fprintf(stderr, "Wrong address family %d\n",
  95                         rth->local.nl_family);
  96                 return -1;
  97         }
  98         rth->seq = time(NULL);
  99         return 0;
 100 }
 101
 102 int rtnl_open(struct rtnl_handle *rth, unsigned int subscriptions)
 103 {
 104         return rtnl_open_byproto(rth, subscriptions, NETLINK_ROUTE);
 105 }
 106
 107 int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
 108 {
 109         return rtnl_wilddump_req_filter(rth, family, type, RTEXT_FILTER_VF);
 110 }
 111
 112 int rtnl_wilddump_req_filter(struct rtnl_handle *rth, int family, int type,
 113                             __u32 filt_mask)
 114 {
 115         struct {
 116                 struct nlmsghdr nlh;
 117                 struct ifinfomsg ifm;
 118                 /* attribute has to be NLMSG aligned */
 119                 struct rtattr ext_req __attribute__ ((aligned(NLMSG_ALIGNTO)));
 120                 __u32 ext_filter_mask;
 121         } req = {
 122                 .nlh.nlmsg_len = sizeof(req),
 123                 .nlh.nlmsg_type = type,
 124                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 125                 .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 126                 .ifm.ifi_family = family,
 127                 .ext_req.rta_type = IFLA_EXT_MASK,
 128                 .ext_req.rta_len = RTA_LENGTH(sizeof(__u32)),
 129                 .ext_filter_mask = filt_mask,
 130         };
 131
 132         return send(rth->fd, &req, sizeof(req), 0);
 133 }
 134
 135 int rtnl_wilddump_req_filter_fn(struct rtnl_handle *rth, int family, int type,
 136                                 req_filter_fn_t filter_fn)
 137 {
 138         struct {
 139                 struct nlmsghdr nlh;
 140                 struct ifinfomsg ifm;
 141                 char buf[1024];
 142         } req = {
 143                 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
 144                 .nlh.nlmsg_type = type,
 145                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 146                 .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 147                 .ifm.ifi_family = family,
 148         };
 149         int err;
 150
 151         if (!filter_fn)
 152                 return -EINVAL;
 153
 154         err = filter_fn(&req.nlh, sizeof(req));
 155         if (err)
 156                 return err;
 157
 158         return send(rth->fd, &req, req.nlh.nlmsg_len, 0);
 159 }
 160
 161 int rtnl_wilddump_stats_req_filter(struct rtnl_handle *rth, int fam, int type,
 162                                    __u32 filt_mask)
 163 {
 164         struct {
 165                 struct nlmsghdr nlh;
 166                 struct if_stats_msg ifsm;
 167         } req;
 168
 169         memset(&req, 0, sizeof(req));
 170         req.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct if_stats_msg));
 171         req.nlh.nlmsg_type = type;
 172         req.nlh.nlmsg_flags = NLM_F_DUMP|NLM_F_REQUEST;
 173         req.nlh.nlmsg_pid = 0;
 174         req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
 175         req.ifsm.family = fam;
 176         req.ifsm.filter_mask = filt_mask;
 177
 178         return send(rth->fd, &req, sizeof(req), 0);
 179 }
 180
 181 int rtnl_send(struct rtnl_handle *rth, const void *buf, int len)
 182 {
 183         return send(rth->fd, buf, len, 0);
 184 }
 185
 186 int rtnl_send_check(struct rtnl_handle *rth, const void *buf, int len)
 187 {
 188         struct nlmsghdr *h;
 189         int status;
 190         char resp[1024];
 191
 192         status = send(rth->fd, buf, len, 0);
 193         if (status < 0)
 194                 return status;
 195
 196         /* Check for immediate errors */
 197         status = recv(rth->fd, resp, sizeof(resp), MSG_DONTWAIT|MSG_PEEK);
 198         if (status < 0) {
 199                 if (errno == EAGAIN)
 200                         return 0;
 201                 return -1;
 202         }
 203
 204         for (h = (struct nlmsghdr *)resp; NLMSG_OK(h, status);
 205              h = NLMSG_NEXT(h, status)) {
 206                 if (h->nlmsg_type == NLMSG_ERROR) {
 207                         struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
 208
 209                         if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
 210                                 fprintf(stderr, "ERROR truncated\n");
 211                         else
 212                                 errno = -err->error;
 213                         return -1;
 214                 }
 215         }
 216
 217         return 0;
 218 }
 219
 220 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
 221 {
 222         struct nlmsghdr nlh = {
 223                 .nlmsg_len = NLMSG_LENGTH(len),
 224                 .nlmsg_type = type,
 225                 .nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 226                 .nlmsg_seq = rth->dump = ++rth->seq,
 227         };
 228         struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
 229         struct iovec iov[2] = {
 230                 { .iov_base = &nlh, .iov_len = sizeof(nlh) },
 231                 { .iov_base = req, .iov_len = len }
 232         };
 233         struct msghdr msg = {
 234                 .msg_name = &nladdr,
 235                 .msg_namelen = sizeof(nladdr),
 236                 .msg_iov = iov,
 237                 .msg_iovlen = 2,
 238         };
 239
 240         return sendmsg(rth->fd, &msg, 0);
 241 }
 242
 243 int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
 244 {
 245         struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
 246         struct iovec iov = {
 247                 .iov_base = n,
 248                 .iov_len = n->nlmsg_len
 249         };
 250         struct msghdr msg = {
 251                 .msg_name = &nladdr,
 252                 .msg_namelen = sizeof(nladdr),
 253                 .msg_iov = &iov,
 254                 .msg_iovlen = 1,
 255         };
 256
 257         n->nlmsg_flags = NLM_F_DUMP|NLM_F_REQUEST;
 258         n->nlmsg_pid = 0;
 259         n->nlmsg_seq = rth->dump = ++rth->seq;
 260
 261         return sendmsg(rth->fd, &msg, 0);
 262 }
 263
 264 static int rtnl_dump_done(const struct rtnl_handle *rth,
 265                           struct nlmsghdr *h)
 266 {
 267         int len = *(int *)NLMSG_DATA(h);
 268
 269         if (rth->proto == NETLINK_SOCK_DIAG) {
 270                 if (h->nlmsg_len < NLMSG_LENGTH(sizeof(int))) {
 271                         fprintf(stderr, "DONE truncated\n");
 272                         return -1;
 273                 }
 274
 275
 276                 if (len < 0) {
 277                         errno = -len;
 278                         if (errno == ENOENT || errno == EOPNOTSUPP)
 279                                 return -1;
 280                         perror("RTNETLINK answers");
 281                         return len;
 282                 }
 283         }
 284         return 0;
 285 }
 286
 287 static void rtnl_dump_error(const struct rtnl_handle *rth,
 288                             struct nlmsghdr *h)
 289 {
 290
 291         if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
 292                 fprintf(stderr, "ERROR truncated\n");
 293         } else {
 294                 const struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
 295
 296                 errno = -err->error;
 297                 if (rth->proto == NETLINK_SOCK_DIAG &&
 298                     (errno == ENOENT ||
 299                      errno == EOPNOTSUPP))
 300                         return;
 301
 302                 perror("RTNETLINK answers");
 303         }
 304 }
 305
 306 int rtnl_dump_filter_l(struct rtnl_handle *rth,
 307                        const struct rtnl_dump_filter_arg *arg)
 308 {
 309         struct sockaddr_nl nladdr;
 310         struct iovec iov;
 311         struct msghdr msg = {
 312                 .msg_name = &nladdr,
 313                 .msg_namelen = sizeof(nladdr),
 314                 .msg_iov = &iov,
 315                 .msg_iovlen = 1,
 316         };
 317         char buf[32768];
 318         int dump_intr = 0;
 319
 320         iov.iov_base = buf;
 321         while (1) {
 322                 int status;
 323                 const struct rtnl_dump_filter_arg *a;
 324                 int found_done = 0;
 325                 int msglen = 0;
 326
 327                 iov.iov_len = sizeof(buf);
 328                 status = recvmsg(rth->fd, &msg, 0);
 329
 330                 if (status < 0) {
 331                         if (errno == EINTR || errno == EAGAIN)
 332                                 continue;
 333                         fprintf(stderr, "netlink receive error %s (%d)\n",
 334                                 strerror(errno), errno);
 335                         return -1;
 336                 }
 337
 338                 if (status == 0) {
 339                         fprintf(stderr, "EOF on netlink\n");
 340                         return -1;
 341                 }
 342
 343                 if (rth->dump_fp)
 344                         fwrite(buf, 1, NLMSG_ALIGN(status), rth->dump_fp);
 345
 346                 for (a = arg; a->filter; a++) {
 347                         struct nlmsghdr *h = (struct nlmsghdr *)buf;
 348
 349                         msglen = status;
 350
 351                         while (NLMSG_OK(h, msglen)) {
 352                                 int err = 0;
 353
 354                                 h->nlmsg_flags &= ~a->nc_flags;
 355
 356                                 if (nladdr.nl_pid != 0 ||
 357                                     h->nlmsg_pid != rth->local.nl_pid ||
 358                                     h->nlmsg_seq != rth->dump)
 359                                         goto skip_it;
 360
 361                                 if (h->nlmsg_flags & NLM_F_DUMP_INTR)
 362                                         dump_intr = 1;
 363
 364                                 if (h->nlmsg_type == NLMSG_DONE) {
 365                                         err = rtnl_dump_done(rth, h);
 366                                         if (err < 0)
 367                                                 return -1;
 368
 369                                         found_done = 1;
 370                                         break; /* process next filter */
 371                                 }
 372
 373                                 if (h->nlmsg_type == NLMSG_ERROR) {
 374                                         rtnl_dump_error(rth, h);
 375                                         return -1;
 376                                 }
 377
 378                                 if (!rth->dump_fp) {
 379                                         err = a->filter(&nladdr, h, a->arg1);
 380                                         if (err < 0)
 381                                                 return err;
 382                                 }
 383
 384 skip_it:
 385                                 h = NLMSG_NEXT(h, msglen);
 386                         }
 387                 }
 388
 389                 if (found_done) {
 390                         if (dump_intr)
 391                                 fprintf(stderr,
 392                                         "Dump was interrupted and may be inconsistent.\n");
 393                         return 0;
 394                 }
 395
 396                 if (msg.msg_flags & MSG_TRUNC) {
 397                         fprintf(stderr, "Message truncated\n");
 398                         continue;
 399                 }
 400                 if (msglen) {
 401                         fprintf(stderr, "!!!Remnant of size %d\n", msglen);
 402                         exit(1);
 403                 }
 404         }
 405 }
 406
 407 int rtnl_dump_filter_nc(struct rtnl_handle *rth,
 408                      rtnl_filter_t filter,
 409                      void *arg1, __u16 nc_flags)
 410 {
 411         const struct rtnl_dump_filter_arg a[2] = {
 412                 { .filter = filter, .arg1 = arg1, .nc_flags = nc_flags, },
 413                 { .filter = NULL,   .arg1 = NULL, .nc_flags = 0, },
 414         };
 415
 416         return rtnl_dump_filter_l(rth, a);
 417 }
 418
 419 static int __rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
 420                        struct nlmsghdr *answer, size_t maxlen,
 421                        bool show_rtnl_err)
 422 {
 423         int status;
 424         unsigned int seq;
 425         struct nlmsghdr *h;
 426         struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
 427         struct iovec iov = {
 428                 .iov_base = n,
 429                 .iov_len = n->nlmsg_len
 430         };
 431         struct msghdr msg = {
 432                 .msg_name = &nladdr,
 433                 .msg_namelen = sizeof(nladdr),
 434                 .msg_iov = &iov,
 435                 .msg_iovlen = 1,
 436         };
 437         char   buf[32768] = {};
 438
 439         n->nlmsg_seq = seq = ++rtnl->seq;
 440
 441         if (answer == NULL)
 442                 n->nlmsg_flags |= NLM_F_ACK;
 443
 444         status = sendmsg(rtnl->fd, &msg, 0);
 445         if (status < 0) {
 446                 perror("Cannot talk to rtnetlink");
 447                 return -1;
 448         }
 449
 450         iov.iov_base = buf;
 451         while (1) {
 452                 iov.iov_len = sizeof(buf);
 453                 status = recvmsg(rtnl->fd, &msg, 0);
 454
 455                 if (status < 0) {
 456                         if (errno == EINTR || errno == EAGAIN)
 457                                 continue;
 458                         fprintf(stderr, "netlink receive error %s (%d)\n",
 459                                 strerror(errno), errno);
 460                         return -1;
 461                 }
 462                 if (status == 0) {
 463                         fprintf(stderr, "EOF on netlink\n");
 464                         return -1;
 465                 }
 466                 if (msg.msg_namelen != sizeof(nladdr)) {
 467                         fprintf(stderr,
 468                                 "sender address length == %d\n",
 469                                 msg.msg_namelen);
 470                         exit(1);
 471                 }
 472                 for (h = (struct nlmsghdr *)buf; status >= sizeof(*h); ) {
 473                         int len = h->nlmsg_len;
 474                         int l = len - sizeof(*h);
 475
 476                         if (l < 0 || len > status) {
 477                                 if (msg.msg_flags & MSG_TRUNC) {
 478                                         fprintf(stderr, "Truncated message\n");
 479                                         return -1;
 480                                 }
 481                                 fprintf(stderr,
 482                                         "!!!malformed message: len=%d\n",
 483                                         len);
 484                                 exit(1);
 485                         }
 486
 487                         if (nladdr.nl_pid != 0 ||
 488                             h->nlmsg_pid != rtnl->local.nl_pid ||
 489                             h->nlmsg_seq != seq) {
 490                                 /* Don't forget to skip that message. */
 491                                 status -= NLMSG_ALIGN(len);
 492                                 h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
 493                                 continue;
 494                         }
 495
 496                         if (h->nlmsg_type == NLMSG_ERROR) {
 497                                 struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
 498
 499                                 if (l < sizeof(struct nlmsgerr)) {
 500                                         fprintf(stderr, "ERROR truncated\n");
 501                                 } else if (!err->error) {
 502                                         if (answer)
 503                                                 memcpy(answer, h,
 504                                                        MIN(maxlen, h->nlmsg_len));
 505                                         return 0;
 506                                 }
 507
 508                                 if (rtnl->proto != NETLINK_SOCK_DIAG && show_rtnl_err)
 509                                         fprintf(stderr,
 510                                                 "RTNETLINK answers: %s\n",
 511                                                 strerror(-err->error));
 512                                 errno = -err->error;
 513                                 return -1;
 514                         }
 515
 516                         if (answer) {
 517                                 memcpy(answer, h,
 518                                        MIN(maxlen, h->nlmsg_len));
 519                                 return 0;
 520                         }
 521
 522                         fprintf(stderr, "Unexpected reply!!!\n");
 523
 524                         status -= NLMSG_ALIGN(len);
 525                         h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
 526                 }
 527
 528                 if (msg.msg_flags & MSG_TRUNC) {
 529                         fprintf(stderr, "Message truncated\n");
 530                         continue;
 531                 }
 532
 533                 if (status) {
 534                         fprintf(stderr, "!!!Remnant of size %d\n", status);
 535                         exit(1);
 536                 }
 537         }
 538 }
 539
 540 int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
 541               struct nlmsghdr *answer, size_t maxlen)
 542 {
 543         return __rtnl_talk(rtnl, n, answer, maxlen, true);
 544 }
 545
 546 int rtnl_talk_suppress_rtnl_errmsg(struct rtnl_handle *rtnl, struct nlmsghdr *n,
 547                                    struct nlmsghdr *answer, size_t maxlen)
 548 {
 549         return __rtnl_talk(rtnl, n, answer, maxlen, false);
 550 }
 551
 552 int rtnl_listen_all_nsid(struct rtnl_handle *rth)
 553 {
 554         unsigned int on = 1;
 555
 556         if (setsockopt(rth->fd, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, &on,
 557                        sizeof(on)) < 0) {
 558                 perror("NETLINK_LISTEN_ALL_NSID");
 559                 return -1;
 560         }
 561         rth->flags |= RTNL_HANDLE_F_LISTEN_ALL_NSID;
 562         return 0;
 563 }
 564
 565 int rtnl_listen(struct rtnl_handle *rtnl,
 566                 rtnl_listen_filter_t handler,
 567                 void *jarg)
 568 {
 569         int status;
 570         struct nlmsghdr *h;
 571         struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
 572         struct iovec iov;
 573         struct msghdr msg = {
 574                 .msg_name = &nladdr,
 575                 .msg_namelen = sizeof(nladdr),
 576                 .msg_iov = &iov,
 577                 .msg_iovlen = 1,
 578         };
 579         char   buf[16384];
 580         char   cmsgbuf[BUFSIZ];
 581
 582         if (rtnl->flags & RTNL_HANDLE_F_LISTEN_ALL_NSID) {
 583                 msg.msg_control = &cmsgbuf;
 584                 msg.msg_controllen = sizeof(cmsgbuf);
 585         }
 586
 587         iov.iov_base = buf;
 588         while (1) {
 589                 struct rtnl_ctrl_data ctrl;
 590                 struct cmsghdr *cmsg;
 591
 592                 iov.iov_len = sizeof(buf);
 593                 status = recvmsg(rtnl->fd, &msg, 0);
 594
 595                 if (status < 0) {
 596                         if (errno == EINTR || errno == EAGAIN)
 597                                 continue;
 598                         fprintf(stderr, "netlink receive error %s (%d)\n",
 599                                 strerror(errno), errno);
 600                         if (errno == ENOBUFS)
 601                                 continue;
 602                         return -1;
 603                 }
 604                 if (status == 0) {
 605                         fprintf(stderr, "EOF on netlink\n");
 606                         return -1;
 607                 }
 608                 if (msg.msg_namelen != sizeof(nladdr)) {
 609                         fprintf(stderr,
 610                                 "Sender address length == %d\n",
 611                                 msg.msg_namelen);
 612                         exit(1);
 613                 }
 614
 615                 if (rtnl->flags & RTNL_HANDLE_F_LISTEN_ALL_NSID) {
 616                         memset(&ctrl, 0, sizeof(ctrl));
 617                         ctrl.nsid = -1;
 618                         for (cmsg = CMSG_FIRSTHDR(&msg); cmsg;
 619                              cmsg = CMSG_NXTHDR(&msg, cmsg))
 620                                 if (cmsg->cmsg_level == SOL_NETLINK &&
 621                                     cmsg->cmsg_type == NETLINK_LISTEN_ALL_NSID &&
 622                                     cmsg->cmsg_len == CMSG_LEN(sizeof(int))) {
 623                                         int *data = (int *)CMSG_DATA(cmsg);
 624
 625                                         ctrl.nsid = *data;
 626                                 }
 627                 }
 628
 629                 for (h = (struct nlmsghdr *)buf; status >= sizeof(*h); ) {
 630                         int err;
 631                         int len = h->nlmsg_len;
 632                         int l = len - sizeof(*h);
 633
 634                         if (l < 0 || len > status) {
 635                                 if (msg.msg_flags & MSG_TRUNC) {
 636                                         fprintf(stderr, "Truncated message\n");
 637                                         return -1;
 638                                 }
 639                                 fprintf(stderr,
 640                                         "!!!malformed message: len=%d\n",
 641                                         len);
 642                                 exit(1);
 643                         }
 644
 645                         err = handler(&nladdr, &ctrl, h, jarg);
 646                         if (err < 0)
 647                                 return err;
 648
 649                         status -= NLMSG_ALIGN(len);
 650                         h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
 651                 }
 652                 if (msg.msg_flags & MSG_TRUNC) {
 653                         fprintf(stderr, "Message truncated\n");
 654                         continue;
 655                 }
 656                 if (status) {
 657                         fprintf(stderr, "!!!Remnant of size %d\n", status);
 658                         exit(1);
 659                 }
 660         }
 661 }
 662
 663 int rtnl_from_file(FILE *rtnl, rtnl_listen_filter_t handler,
 664                    void *jarg)
 665 {
 666         int status;
 667         struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
 668         char buf[16384];
 669         struct nlmsghdr *h = (struct nlmsghdr *)buf;
 670
 671         while (1) {
 672                 int err, len;
 673                 int l;
 674
 675                 status = fread(&buf, 1, sizeof(*h), rtnl);
 676
 677                 if (status < 0) {
 678                         if (errno == EINTR)
 679                                 continue;
 680                         perror("rtnl_from_file: fread");
 681                         return -1;
 682                 }
 683                 if (status == 0)
 684                         return 0;
 685
 686                 len = h->nlmsg_len;
 687                 l = len - sizeof(*h);
 688
 689                 if (l < 0 || len > sizeof(buf)) {
 690                         fprintf(stderr, "!!!malformed message: len=%d @%lu\n",
 691                                 len, ftell(rtnl));
 692                         return -1;
 693                 }
 694
 695                 status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
 696
 697                 if (status < 0) {
 698                         perror("rtnl_from_file: fread");
 699                         return -1;
 700                 }
 701                 if (status < l) {
 702                         fprintf(stderr, "rtnl-from_file: truncated message\n");
 703                         return -1;
 704                 }
 705
 706                 err = handler(&nladdr, NULL, h, jarg);
 707                 if (err < 0)
 708                         return err;
 709         }
 710 }
 711
 712 int addattr(struct nlmsghdr *n, int maxlen, int type)
 713 {
 714         return addattr_l(n, maxlen, type, NULL, 0);
 715 }
 716
 717 int addattr8(struct nlmsghdr *n, int maxlen, int type, __u8 data)
 718 {
 719         return addattr_l(n, maxlen, type, &data, sizeof(__u8));
 720 }
 721
 722 int addattr16(struct nlmsghdr *n, int maxlen, int type, __u16 data)
 723 {
 724         return addattr_l(n, maxlen, type, &data, sizeof(__u16));
 725 }
 726
 727 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
 728 {
 729         return addattr_l(n, maxlen, type, &data, sizeof(__u32));
 730 }
 731
 732 int addattr64(struct nlmsghdr *n, int maxlen, int type, __u64 data)
 733 {
 734         return addattr_l(n, maxlen, type, &data, sizeof(__u64));
 735 }
 736
 737 int addattrstrz(struct nlmsghdr *n, int maxlen, int type, const char *str)
 738 {
 739         return addattr_l(n, maxlen, type, str, strlen(str)+1);
 740 }
 741
 742 int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
 743               int alen)
 744 {
 745         int len = RTA_LENGTH(alen);
 746         struct rtattr *rta;
 747
 748         if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
 749                 fprintf(stderr,
 750                         "addattr_l ERROR: message exceeded bound of %d\n",
 751                         maxlen);
 752                 return -1;
 753         }
 754         rta = NLMSG_TAIL(n);
 755         rta->rta_type = type;
 756         rta->rta_len = len;
 757         memcpy(RTA_DATA(rta), data, alen);
 758         n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
 759         return 0;
 760 }
 761
 762 int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len)
 763 {
 764         if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) {
 765                 fprintf(stderr,
 766                         "addraw_l ERROR: message exceeded bound of %d\n",
 767                         maxlen);
 768                 return -1;
 769         }
 770
 771         memcpy(NLMSG_TAIL(n), data, len);
 772         memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len);
 773         n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len);
 774         return 0;
 775 }
 776
 777 struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type)
 778 {
 779         struct rtattr *nest = NLMSG_TAIL(n);
 780
 781         addattr_l(n, maxlen, type, NULL, 0);
 782         return nest;
 783 }
 784
 785 int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest)
 786 {
 787         nest->rta_len = (void *)NLMSG_TAIL(n) - (void *)nest;
 788         return n->nlmsg_len;
 789 }
 790
 791 struct rtattr *addattr_nest_compat(struct nlmsghdr *n, int maxlen, int type,
 792                                    const void *data, int len)
 793 {
 794         struct rtattr *start = NLMSG_TAIL(n);
 795
 796         addattr_l(n, maxlen, type, data, len);
 797         addattr_nest(n, maxlen, type);
 798         return start;
 799 }
 800
 801 int addattr_nest_compat_end(struct nlmsghdr *n, struct rtattr *start)
 802 {
 803         struct rtattr *nest = (void *)start + NLMSG_ALIGN(start->rta_len);
 804
 805         start->rta_len = (void *)NLMSG_TAIL(n) - (void *)start;
 806         addattr_nest_end(n, nest);
 807         return n->nlmsg_len;
 808 }
 809
 810 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
 811 {
 812         int len = RTA_LENGTH(4);
 813         struct rtattr *subrta;
 814
 815         if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
 816                 fprintf(stderr,
 817                         "rta_addattr32: Error! max allowed bound %d exceeded\n",
 818                         maxlen);
 819                 return -1;
 820         }
 821         subrta = (struct rtattr *)(((char *)rta) + RTA_ALIGN(rta->rta_len));
 822         subrta->rta_type = type;
 823         subrta->rta_len = len;
 824         memcpy(RTA_DATA(subrta), &data, 4);
 825         rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
 826         return 0;
 827 }
 828
 829 int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
 830                   const void *data, int alen)
 831 {
 832         struct rtattr *subrta;
 833         int len = RTA_LENGTH(alen);
 834
 835         if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen) {
 836                 fprintf(stderr,
 837                         "rta_addattr_l: Error! max allowed bound %d exceeded\n",
 838                         maxlen);
 839                 return -1;
 840         }
 841         subrta = (struct rtattr *)(((char *)rta) + RTA_ALIGN(rta->rta_len));
 842         subrta->rta_type = type;
 843         subrta->rta_len = len;
 844         memcpy(RTA_DATA(subrta), data, alen);
 845         rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len);
 846         return 0;
 847 }
 848
 849 int rta_addattr8(struct rtattr *rta, int maxlen, int type, __u8 data)
 850 {
 851         return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u8));
 852 }
 853
 854 int rta_addattr16(struct rtattr *rta, int maxlen, int type, __u16 data)
 855 {
 856         return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u16));
 857 }
 858
 859 int rta_addattr64(struct rtattr *rta, int maxlen, int type, __u64 data)
 860 {
 861         return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u64));
 862 }
 863
 864 struct rtattr *rta_nest(struct rtattr *rta, int maxlen, int type)
 865 {
 866         struct rtattr *nest = RTA_TAIL(rta);
 867
 868         rta_addattr_l(rta, maxlen, type, NULL, 0);
 869
 870         return nest;
 871 }
 872
 873 int rta_nest_end(struct rtattr *rta, struct rtattr *nest)
 874 {
 875         nest->rta_len = (void *)RTA_TAIL(rta) - (void *)nest;
 876
 877         return rta->rta_len;
 878 }
 879
 880 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
 881 {
 882         return parse_rtattr_flags(tb, max, rta, len, 0);
 883 }
 884
 885 int parse_rtattr_flags(struct rtattr *tb[], int max, struct rtattr *rta,
 886                        int len, unsigned short flags)
 887 {
 888         unsigned short type;
 889
 890         memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
 891         while (RTA_OK(rta, len)) {
 892                 type = rta->rta_type & ~flags;
 893                 if ((type <= max) && (!tb[type]))
 894                         tb[type] = rta;
 895                 rta = RTA_NEXT(rta, len);
 896         }
 897         if (len)
 898                 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n",
 899                         len, rta->rta_len);
 900         return 0;
 901 }
 902
 903 int parse_rtattr_byindex(struct rtattr *tb[], int max,
 904                          struct rtattr *rta, int len)
 905 {
 906         int i = 0;
 907
 908         memset(tb, 0, sizeof(struct rtattr *) * max);
 909         while (RTA_OK(rta, len)) {
 910                 if (rta->rta_type <= max && i < max)
 911                         tb[i++] = rta;
 912                 rta = RTA_NEXT(rta, len);
 913         }
 914         if (len)
 915                 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n",
 916                         len, rta->rta_len);
 917         return i;
 918 }
 919
 920 struct rtattr *parse_rtattr_one(int type, struct rtattr *rta, int len)
 921 {
 922         while (RTA_OK(rta, len)) {
 923                 if (rta->rta_type == type)
 924                         return rta;
 925                 rta = RTA_NEXT(rta, len);
 926         }
 927
 928         if (len)
 929                 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n",
 930                         len, rta->rta_len);
 931         return NULL;
 932 }
 933
 934 int __parse_rtattr_nested_compat(struct rtattr *tb[], int max,
 935                                  struct rtattr *rta,
 936                                  int len)
 937 {
 938         if (RTA_PAYLOAD(rta) < len)
 939                 return -1;
 940         if (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) {
 941                 rta = RTA_DATA(rta) + RTA_ALIGN(len);
 942                 return parse_rtattr_nested(tb, max, rta);
 943         }
 944         memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
 945         return 0;
 946 }