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 #ifdef HAVE_LIBMNL
  40 #include <libmnl/libmnl.h>
  41
  42 static const enum mnl_attr_data_type extack_policy[NLMSGERR_ATTR_MAX + 1] = {
  43         [NLMSGERR_ATTR_MSG]     = MNL_TYPE_NUL_STRING,
  44         [NLMSGERR_ATTR_OFFS]    = MNL_TYPE_U32,
  45 };
  46
  47 static int err_attr_cb(const struct nlattr *attr, void *data)
  48 {
  49         const struct nlattr **tb = data;
  50         uint16_t type;
  51
  52         if (mnl_attr_type_valid(attr, NLMSGERR_ATTR_MAX) < 0)
  53                 return MNL_CB_ERROR;
  54
  55         type = mnl_attr_get_type(attr);
  56         if (mnl_attr_validate(attr, extack_policy[type]) < 0)
  57                 return MNL_CB_ERROR;
  58
  59
  60         tb[type] = attr;
  61         return MNL_CB_OK;
  62 }
  63
  64
  65 /* dump netlink extended ack error message */
  66 static int nl_dump_ext_err(const struct nlmsghdr *nlh, nl_ext_ack_fn_t errfn)
  67 {
  68         struct nlattr *tb[NLMSGERR_ATTR_MAX + 1];
  69         const struct nlmsgerr *err = mnl_nlmsg_get_payload(nlh);
  70         const struct nlmsghdr *err_nlh = NULL;
  71         unsigned int hlen = sizeof(*err);
  72         const char *errmsg = NULL;
  73         uint32_t off = 0;
  74
  75         if (!errfn)
  76                 return 0;
  77
  78         /* no TLVs, nothing to do here */
  79         if (!(nlh->nlmsg_flags & NLM_F_ACK_TLVS))
  80                 return 0;
  81
  82         /* if NLM_F_CAPPED is set then the inner err msg was capped */
  83         if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
  84                 hlen += mnl_nlmsg_get_payload_len(&err->msg);
  85
  86         mnl_attr_parse(nlh, hlen, err_attr_cb, tb);
  87
  88         if (tb[NLMSGERR_ATTR_MSG])
  89                 errmsg = mnl_attr_get_str(tb[NLMSGERR_ATTR_MSG]);
  90
  91         if (tb[NLMSGERR_ATTR_OFFS]) {
  92                 off = mnl_attr_get_u32(tb[NLMSGERR_ATTR_OFFS]);
  93
  94                 if (off > nlh->nlmsg_len) {
  95                         fprintf(stderr,
  96                                 "Invalid offset for NLMSGERR_ATTR_OFFS\n");
  97                         off = 0;
  98                 } else if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
  99                         err_nlh = &err->msg;
 100         }
 101
 102         return errfn(errmsg, off, err_nlh);
 103 }
 104 #else
 105 /* No extended error ack without libmnl */
 106 static int nl_dump_ext_err(const struct nlmsghdr *nlh, nl_ext_ack_fn_t errfn)
 107 {
 108         return 0;
 109 }
 110 #endif
 111
 112 void rtnl_close(struct rtnl_handle *rth)
 113 {
 114         if (rth->fd >= 0) {
 115                 close(rth->fd);
 116                 rth->fd = -1;
 117         }
 118 }
 119
 120 int rtnl_open_byproto(struct rtnl_handle *rth, unsigned int subscriptions,
 121                       int protocol)
 122 {
 123         socklen_t addr_len;
 124         int sndbuf = 32768;
 125         int one = 1;
 126
 127         memset(rth, 0, sizeof(*rth));
 128
 129         rth->proto = protocol;
 130         rth->fd = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, protocol);
 131         if (rth->fd < 0) {
 132                 perror("Cannot open netlink socket");
 133                 return -1;
 134         }
 135
 136         if (setsockopt(rth->fd, SOL_SOCKET, SO_SNDBUF,
 137                        &sndbuf, sizeof(sndbuf)) < 0) {
 138                 perror("SO_SNDBUF");
 139                 return -1;
 140         }
 141
 142         if (setsockopt(rth->fd, SOL_SOCKET, SO_RCVBUF,
 143                        &rcvbuf, sizeof(rcvbuf)) < 0) {
 144                 perror("SO_RCVBUF");
 145                 return -1;
 146         }
 147
 148         /* Older kernels may no support extended ACK reporting */
 149         setsockopt(rth->fd, SOL_NETLINK, NETLINK_EXT_ACK,
 150                    &one, sizeof(one));
 151
 152         memset(&rth->local, 0, sizeof(rth->local));
 153         rth->local.nl_family = AF_NETLINK;
 154         rth->local.nl_groups = subscriptions;
 155
 156         if (bind(rth->fd, (struct sockaddr *)&rth->local,
 157                  sizeof(rth->local)) < 0) {
 158                 perror("Cannot bind netlink socket");
 159                 return -1;
 160         }
 161         addr_len = sizeof(rth->local);
 162         if (getsockname(rth->fd, (struct sockaddr *)&rth->local,
 163                         &addr_len) < 0) {
 164                 perror("Cannot getsockname");
 165                 return -1;
 166         }
 167         if (addr_len != sizeof(rth->local)) {
 168                 fprintf(stderr, "Wrong address length %d\n", addr_len);
 169                 return -1;
 170         }
 171         if (rth->local.nl_family != AF_NETLINK) {
 172                 fprintf(stderr, "Wrong address family %d\n",
 173                         rth->local.nl_family);
 174                 return -1;
 175         }
 176         rth->seq = time(NULL);
 177         return 0;
 178 }
 179
 180 int rtnl_open(struct rtnl_handle *rth, unsigned int subscriptions)
 181 {
 182         return rtnl_open_byproto(rth, subscriptions, NETLINK_ROUTE);
 183 }
 184
 185 int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
 186 {
 187         return rtnl_wilddump_req_filter(rth, family, type, RTEXT_FILTER_VF);
 188 }
 189
 190 int rtnl_wilddump_req_filter(struct rtnl_handle *rth, int family, int type,
 191                             __u32 filt_mask)
 192 {
 193         struct {
 194                 struct nlmsghdr nlh;
 195                 struct ifinfomsg ifm;
 196                 /* attribute has to be NLMSG aligned */
 197                 struct rtattr ext_req __attribute__ ((aligned(NLMSG_ALIGNTO)));
 198                 __u32 ext_filter_mask;
 199         } req = {
 200                 .nlh.nlmsg_len = sizeof(req),
 201                 .nlh.nlmsg_type = type,
 202                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 203                 .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 204                 .ifm.ifi_family = family,
 205                 .ext_req.rta_type = IFLA_EXT_MASK,
 206                 .ext_req.rta_len = RTA_LENGTH(sizeof(__u32)),
 207                 .ext_filter_mask = filt_mask,
 208         };
 209
 210         return send(rth->fd, &req, sizeof(req), 0);
 211 }
 212
 213 int rtnl_wilddump_req_filter_fn(struct rtnl_handle *rth, int family, int type,
 214                                 req_filter_fn_t filter_fn)
 215 {
 216         struct {
 217                 struct nlmsghdr nlh;
 218                 struct ifinfomsg ifm;
 219                 char buf[1024];
 220         } req = {
 221                 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
 222                 .nlh.nlmsg_type = type,
 223                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 224                 .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 225                 .ifm.ifi_family = family,
 226         };
 227         int err;
 228
 229         if (!filter_fn)
 230                 return -EINVAL;
 231
 232         err = filter_fn(&req.nlh, sizeof(req));
 233         if (err)
 234                 return err;
 235
 236         return send(rth->fd, &req, req.nlh.nlmsg_len, 0);
 237 }
 238
 239 int rtnl_wilddump_stats_req_filter(struct rtnl_handle *rth, int fam, int type,
 240                                    __u32 filt_mask)
 241 {
 242         struct {
 243                 struct nlmsghdr nlh;
 244                 struct if_stats_msg ifsm;
 245         } req;
 246
 247         memset(&req, 0, sizeof(req));
 248         req.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct if_stats_msg));
 249         req.nlh.nlmsg_type = type;
 250         req.nlh.nlmsg_flags = NLM_F_DUMP|NLM_F_REQUEST;
 251         req.nlh.nlmsg_pid = 0;
 252         req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
 253         req.ifsm.family = fam;
 254         req.ifsm.filter_mask = filt_mask;
 255
 256         return send(rth->fd, &req, sizeof(req), 0);
 257 }
 258
 259 int rtnl_send(struct rtnl_handle *rth, const void *buf, int len)
 260 {
 261         return send(rth->fd, buf, len, 0);
 262 }
 263
 264 int rtnl_send_check(struct rtnl_handle *rth, const void *buf, int len)
 265 {
 266         struct nlmsghdr *h;
 267         int status;
 268         char resp[1024];
 269
 270         status = send(rth->fd, buf, len, 0);
 271         if (status < 0)
 272                 return status;
 273
 274         /* Check for immediate errors */
 275         status = recv(rth->fd, resp, sizeof(resp), MSG_DONTWAIT|MSG_PEEK);
 276         if (status < 0) {
 277                 if (errno == EAGAIN)
 278                         return 0;
 279                 return -1;
 280         }
 281
 282         for (h = (struct nlmsghdr *)resp; NLMSG_OK(h, status);
 283              h = NLMSG_NEXT(h, status)) {
 284                 if (h->nlmsg_type == NLMSG_ERROR) {
 285                         struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
 286
 287                         if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
 288                                 fprintf(stderr, "ERROR truncated\n");
 289                         else
 290                                 errno = -err->error;
 291                         return -1;
 292                 }
 293         }
 294
 295         return 0;
 296 }
 297
 298 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
 299 {
 300         struct nlmsghdr nlh = {
 301                 .nlmsg_len = NLMSG_LENGTH(len),
 302                 .nlmsg_type = type,
 303                 .nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 304                 .nlmsg_seq = rth->dump = ++rth->seq,
 305         };
 306         struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
 307         struct iovec iov[2] = {
 308                 { .iov_base = &nlh, .iov_len = sizeof(nlh) },
 309                 { .iov_base = req, .iov_len = len }
 310         };
 311         struct msghdr msg = {
 312                 .msg_name = &nladdr,
 313                 .msg_namelen = sizeof(nladdr),
 314                 .msg_iov = iov,
 315                 .msg_iovlen = 2,
 316         };
 317
 318         return sendmsg(rth->fd, &msg, 0);
 319 }
 320
 321 int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
 322 {
 323         struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
 324         struct iovec iov = {
 325                 .iov_base = n,
 326                 .iov_len = n->nlmsg_len
 327         };
 328         struct msghdr msg = {
 329                 .msg_name = &nladdr,
 330                 .msg_namelen = sizeof(nladdr),
 331                 .msg_iov = &iov,
 332                 .msg_iovlen = 1,
 333         };
 334
 335         n->nlmsg_flags = NLM_F_DUMP|NLM_F_REQUEST;
 336         n->nlmsg_pid = 0;
 337         n->nlmsg_seq = rth->dump = ++rth->seq;
 338
 339         return sendmsg(rth->fd, &msg, 0);
 340 }
 341
 342 static int rtnl_dump_done(const struct rtnl_handle *rth,
 343                           struct nlmsghdr *h)
 344 {
 345         int len = *(int *)NLMSG_DATA(h);
 346
 347         if (h->nlmsg_len < NLMSG_LENGTH(sizeof(int))) {
 348                 fprintf(stderr, "DONE truncated\n");
 349                 return -1;
 350         }
 351
 352         if (len < 0) {
 353                 errno = -len;
 354                 switch (errno) {
 355                 case ENOENT:
 356                 case EOPNOTSUPP:
 357                         return -1;
 358                 case EMSGSIZE:
 359                         fprintf(stderr,
 360                                 "Error: Buffer too small for object.\n");
 361                         break;
 362                 default:
 363                         perror("RTNETLINK answers");
 364                 }
 365                 return len;
 366         }
 367
 368         return 0;
 369 }
 370
 371 static void rtnl_dump_error(const struct rtnl_handle *rth,
 372                             struct nlmsghdr *h)
 373 {
 374
 375         if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
 376                 fprintf(stderr, "ERROR truncated\n");
 377         } else {
 378                 const struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
 379
 380                 errno = -err->error;
 381                 if (rth->proto == NETLINK_SOCK_DIAG &&
 382                     (errno == ENOENT ||
 383                      errno == EOPNOTSUPP))
 384                         return;
 385
 386                 if (!(rth->flags & RTNL_HANDLE_F_SUPPRESS_NLERR))
 387                         perror("RTNETLINK answers");
 388         }
 389 }
 390
 391 int rtnl_dump_filter_l(struct rtnl_handle *rth,
 392                        const struct rtnl_dump_filter_arg *arg)
 393 {
 394         struct sockaddr_nl nladdr;
 395         struct iovec iov;
 396         struct msghdr msg = {
 397                 .msg_name = &nladdr,
 398                 .msg_namelen = sizeof(nladdr),
 399                 .msg_iov = &iov,
 400                 .msg_iovlen = 1,
 401         };
 402         char buf[32768];
 403         int dump_intr = 0;
 404
 405         iov.iov_base = buf;
 406         while (1) {
 407                 int status;
 408                 const struct rtnl_dump_filter_arg *a;
 409                 int found_done = 0;
 410                 int msglen = 0;
 411
 412                 iov.iov_len = sizeof(buf);
 413                 status = recvmsg(rth->fd, &msg, 0);
 414
 415                 if (status < 0) {
 416                         if (errno == EINTR || errno == EAGAIN)
 417                                 continue;
 418                         fprintf(stderr, "netlink receive error %s (%d)\n",
 419                                 strerror(errno), errno);
 420                         return -1;
 421                 }
 422
 423                 if (status == 0) {
 424                         fprintf(stderr, "EOF on netlink\n");
 425                         return -1;
 426                 }
 427
 428                 if (rth->dump_fp)
 429                         fwrite(buf, 1, NLMSG_ALIGN(status), rth->dump_fp);
 430
 431                 for (a = arg; a->filter; a++) {
 432                         struct nlmsghdr *h = (struct nlmsghdr *)buf;
 433
 434                         msglen = status;
 435
 436                         while (NLMSG_OK(h, msglen)) {
 437                                 int err = 0;
 438
 439                                 h->nlmsg_flags &= ~a->nc_flags;
 440
 441                                 if (nladdr.nl_pid != 0 ||
 442                                     h->nlmsg_pid != rth->local.nl_pid ||
 443                                     h->nlmsg_seq != rth->dump)
 444                                         goto skip_it;
 445
 446                                 if (h->nlmsg_flags & NLM_F_DUMP_INTR)
 447                                         dump_intr = 1;
 448
 449                                 if (h->nlmsg_type == NLMSG_DONE) {
 450                                         err = rtnl_dump_done(rth, h);
 451                                         if (err < 0)
 452                                                 return -1;
 453
 454                                         found_done = 1;
 455                                         break; /* process next filter */
 456                                 }
 457
 458                                 if (h->nlmsg_type == NLMSG_ERROR) {
 459                                         rtnl_dump_error(rth, h);
 460                                         return -1;
 461                                 }
 462
 463                                 if (!rth->dump_fp) {
 464                                         err = a->filter(&nladdr, h, a->arg1);
 465                                         if (err < 0)
 466                                                 return err;
 467                                 }
 468
 469 skip_it:
 470                                 h = NLMSG_NEXT(h, msglen);
 471                         }
 472                 }
 473
 474                 if (found_done) {
 475                         if (dump_intr)
 476                                 fprintf(stderr,
 477                                         "Dump was interrupted and may be inconsistent.\n");
 478                         return 0;
 479                 }
 480
 481                 if (msg.msg_flags & MSG_TRUNC) {
 482                         fprintf(stderr, "Message truncated\n");
 483                         continue;
 484                 }
 485                 if (msglen) {
 486                         fprintf(stderr, "!!!Remnant of size %d\n", msglen);
 487                         exit(1);
 488                 }
 489         }
 490 }
 491
 492 int rtnl_dump_filter_nc(struct rtnl_handle *rth,
 493                      rtnl_filter_t filter,
 494                      void *arg1, __u16 nc_flags)
 495 {
 496         const struct rtnl_dump_filter_arg a[2] = {
 497                 { .filter = filter, .arg1 = arg1, .nc_flags = nc_flags, },
 498                 { .filter = NULL,   .arg1 = NULL, .nc_flags = 0, },
 499         };
 500
 501         return rtnl_dump_filter_l(rth, a);
 502 }
 503
 504 static void rtnl_talk_error(struct nlmsghdr *h, struct nlmsgerr *err,
 505                             nl_ext_ack_fn_t errfn)
 506 {
 507         if (nl_dump_ext_err(h, errfn))
 508                 return;
 509
 510         fprintf(stderr, "RTNETLINK answers: %s\n",
 511                 strerror(-err->error));
 512 }
 513
 514 static int __rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
 515                        struct nlmsghdr *answer, size_t maxlen,
 516                        bool show_rtnl_err, nl_ext_ack_fn_t errfn)
 517 {
 518         int status;
 519         unsigned int seq;
 520         struct nlmsghdr *h;
 521         struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
 522         struct iovec iov = {
 523                 .iov_base = n,
 524                 .iov_len = n->nlmsg_len
 525         };
 526         struct msghdr msg = {
 527                 .msg_name = &nladdr,
 528                 .msg_namelen = sizeof(nladdr),
 529                 .msg_iov = &iov,
 530                 .msg_iovlen = 1,
 531         };
 532         char   buf[32768] = {};
 533
 534         n->nlmsg_seq = seq = ++rtnl->seq;
 535
 536         if (answer == NULL)
 537                 n->nlmsg_flags |= NLM_F_ACK;
 538
 539         status = sendmsg(rtnl->fd, &msg, 0);
 540         if (status < 0) {
 541                 perror("Cannot talk to rtnetlink");
 542                 return -1;
 543         }
 544
 545         iov.iov_base = buf;
 546         while (1) {
 547                 iov.iov_len = sizeof(buf);
 548                 status = recvmsg(rtnl->fd, &msg, 0);
 549
 550                 if (status < 0) {
 551                         if (errno == EINTR || errno == EAGAIN)
 552                                 continue;
 553                         fprintf(stderr, "netlink receive error %s (%d)\n",
 554                                 strerror(errno), errno);
 555                         return -1;
 556                 }
 557                 if (status == 0) {
 558                         fprintf(stderr, "EOF on netlink\n");
 559                         return -1;
 560                 }
 561                 if (msg.msg_namelen != sizeof(nladdr)) {
 562                         fprintf(stderr,
 563                                 "sender address length == %d\n",
 564                                 msg.msg_namelen);
 565                         exit(1);
 566                 }
 567                 for (h = (struct nlmsghdr *)buf; status >= sizeof(*h); ) {
 568                         int len = h->nlmsg_len;
 569                         int l = len - sizeof(*h);
 570
 571                         if (l < 0 || len > status) {
 572                                 if (msg.msg_flags & MSG_TRUNC) {
 573                                         fprintf(stderr, "Truncated message\n");
 574                                         return -1;
 575                                 }
 576                                 fprintf(stderr,
 577                                         "!!!malformed message: len=%d\n",
 578                                         len);
 579                                 exit(1);
 580                         }
 581
 582                         if (nladdr.nl_pid != 0 ||
 583                             h->nlmsg_pid != rtnl->local.nl_pid ||
 584                             h->nlmsg_seq != seq) {
 585                                 /* Don't forget to skip that message. */
 586                                 status -= NLMSG_ALIGN(len);
 587                                 h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
 588                                 continue;
 589                         }
 590
 591                         if (h->nlmsg_type == NLMSG_ERROR) {
 592                                 struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
 593
 594                                 if (l < sizeof(struct nlmsgerr)) {
 595                                         fprintf(stderr, "ERROR truncated\n");
 596                                 } else if (!err->error) {
 597                                         if (answer)
 598                                                 memcpy(answer, h,
 599                                                        MIN(maxlen, h->nlmsg_len));
 600                                         return 0;
 601                                 }
 602
 603                                 if (rtnl->proto != NETLINK_SOCK_DIAG &&
 604                                     show_rtnl_err)
 605                                         rtnl_talk_error(h, err, errfn);
 606
 607                                 errno = -err->error;
 608                                 return -1;
 609                         }
 610
 611                         if (answer) {
 612                                 memcpy(answer, h,
 613                                        MIN(maxlen, h->nlmsg_len));
 614                                 return 0;
 615                         }
 616
 617                         fprintf(stderr, "Unexpected reply!!!\n");
 618
 619                         status -= NLMSG_ALIGN(len);
 620                         h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
 621                 }
 622
 623                 if (msg.msg_flags & MSG_TRUNC) {
 624                         fprintf(stderr, "Message truncated\n");
 625                         continue;
 626                 }
 627
 628                 if (status) {
 629                         fprintf(stderr, "!!!Remnant of size %d\n", status);
 630                         exit(1);
 631                 }
 632         }
 633 }
 634
 635 int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
 636               struct nlmsghdr *answer, size_t maxlen)
 637 {
 638         return __rtnl_talk(rtnl, n, answer, maxlen, true, NULL);
 639 }
 640
 641 int rtnl_talk_extack(struct rtnl_handle *rtnl, struct nlmsghdr *n,
 642                      struct nlmsghdr *answer, size_t maxlen,
 643                      nl_ext_ack_fn_t errfn)
 644 {
 645         return __rtnl_talk(rtnl, n, answer, maxlen, true, errfn);
 646 }
 647
 648 int rtnl_talk_suppress_rtnl_errmsg(struct rtnl_handle *rtnl, struct nlmsghdr *n,
 649                                    struct nlmsghdr *answer, size_t maxlen)
 650 {
 651         return __rtnl_talk(rtnl, n, answer, maxlen, false, NULL);
 652 }
 653
 654 int rtnl_listen_all_nsid(struct rtnl_handle *rth)
 655 {
 656         unsigned int on = 1;
 657
 658         if (setsockopt(rth->fd, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, &on,
 659                        sizeof(on)) < 0) {
 660                 perror("NETLINK_LISTEN_ALL_NSID");
 661                 return -1;
 662         }
 663         rth->flags |= RTNL_HANDLE_F_LISTEN_ALL_NSID;
 664         return 0;
 665 }
 666
 667 int rtnl_listen(struct rtnl_handle *rtnl,
 668                 rtnl_listen_filter_t handler,
 669                 void *jarg)
 670 {
 671         int status;
 672         struct nlmsghdr *h;
 673         struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
 674         struct iovec iov;
 675         struct msghdr msg = {
 676                 .msg_name = &nladdr,
 677                 .msg_namelen = sizeof(nladdr),
 678                 .msg_iov = &iov,
 679                 .msg_iovlen = 1,
 680         };
 681         char   buf[16384];
 682         char   cmsgbuf[BUFSIZ];
 683
 684         if (rtnl->flags & RTNL_HANDLE_F_LISTEN_ALL_NSID) {
 685                 msg.msg_control = &cmsgbuf;
 686                 msg.msg_controllen = sizeof(cmsgbuf);
 687         }
 688
 689         iov.iov_base = buf;
 690         while (1) {
 691                 struct rtnl_ctrl_data ctrl;
 692                 struct cmsghdr *cmsg;
 693
 694                 iov.iov_len = sizeof(buf);
 695                 status = recvmsg(rtnl->fd, &msg, 0);
 696
 697                 if (status < 0) {
 698                         if (errno == EINTR || errno == EAGAIN)
 699                                 continue;
 700                         fprintf(stderr, "netlink receive error %s (%d)\n",
 701                                 strerror(errno), errno);
 702                         if (errno == ENOBUFS)
 703                                 continue;
 704                         return -1;
 705                 }
 706                 if (status == 0) {
 707                         fprintf(stderr, "EOF on netlink\n");
 708                         return -1;
 709                 }
 710                 if (msg.msg_namelen != sizeof(nladdr)) {
 711                         fprintf(stderr,
 712                                 "Sender address length == %d\n",
 713                                 msg.msg_namelen);
 714                         exit(1);
 715                 }
 716
 717                 if (rtnl->flags & RTNL_HANDLE_F_LISTEN_ALL_NSID) {
 718                         memset(&ctrl, 0, sizeof(ctrl));
 719                         ctrl.nsid = -1;
 720                         for (cmsg = CMSG_FIRSTHDR(&msg); cmsg;
 721                              cmsg = CMSG_NXTHDR(&msg, cmsg))
 722                                 if (cmsg->cmsg_level == SOL_NETLINK &&
 723                                     cmsg->cmsg_type == NETLINK_LISTEN_ALL_NSID &&
 724                                     cmsg->cmsg_len == CMSG_LEN(sizeof(int))) {
 725                                         int *data = (int *)CMSG_DATA(cmsg);
 726
 727                                         ctrl.nsid = *data;
 728                                 }
 729                 }
 730
 731                 for (h = (struct nlmsghdr *)buf; status >= sizeof(*h); ) {
 732                         int err;
 733                         int len = h->nlmsg_len;
 734                         int l = len - sizeof(*h);
 735
 736                         if (l < 0 || len > status) {
 737                                 if (msg.msg_flags & MSG_TRUNC) {
 738                                         fprintf(stderr, "Truncated message\n");
 739                                         return -1;
 740                                 }
 741                                 fprintf(stderr,
 742                                         "!!!malformed message: len=%d\n",
 743                                         len);
 744                                 exit(1);
 745                         }
 746
 747                         err = handler(&nladdr, &ctrl, h, jarg);
 748                         if (err < 0)
 749                                 return err;
 750
 751                         status -= NLMSG_ALIGN(len);
 752                         h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
 753                 }
 754                 if (msg.msg_flags & MSG_TRUNC) {
 755                         fprintf(stderr, "Message truncated\n");
 756                         continue;
 757                 }
 758                 if (status) {
 759                         fprintf(stderr, "!!!Remnant of size %d\n", status);
 760                         exit(1);
 761                 }
 762         }
 763 }
 764
 765 int rtnl_from_file(FILE *rtnl, rtnl_listen_filter_t handler,
 766                    void *jarg)
 767 {
 768         int status;
 769         struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
 770         char buf[16384];
 771         struct nlmsghdr *h = (struct nlmsghdr *)buf;
 772
 773         while (1) {
 774                 int err, len;
 775                 int l;
 776
 777                 status = fread(&buf, 1, sizeof(*h), rtnl);
 778
 779                 if (status < 0) {
 780                         if (errno == EINTR)
 781                                 continue;
 782                         perror("rtnl_from_file: fread");
 783                         return -1;
 784                 }
 785                 if (status == 0)
 786                         return 0;
 787
 788                 len = h->nlmsg_len;
 789                 l = len - sizeof(*h);
 790
 791                 if (l < 0 || len > sizeof(buf)) {
 792                         fprintf(stderr, "!!!malformed message: len=%d @%lu\n",
 793                                 len, ftell(rtnl));
 794                         return -1;
 795                 }
 796
 797                 status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
 798
 799                 if (status < 0) {
 800                         perror("rtnl_from_file: fread");
 801                         return -1;
 802                 }
 803                 if (status < l) {
 804                         fprintf(stderr, "rtnl-from_file: truncated message\n");
 805                         return -1;
 806                 }
 807
 808                 err = handler(&nladdr, NULL, h, jarg);
 809                 if (err < 0)
 810                         return err;
 811         }
 812 }
 813
 814 int addattr(struct nlmsghdr *n, int maxlen, int type)
 815 {
 816         return addattr_l(n, maxlen, type, NULL, 0);
 817 }
 818
 819 int addattr8(struct nlmsghdr *n, int maxlen, int type, __u8 data)
 820 {
 821         return addattr_l(n, maxlen, type, &data, sizeof(__u8));
 822 }
 823
 824 int addattr16(struct nlmsghdr *n, int maxlen, int type, __u16 data)
 825 {
 826         return addattr_l(n, maxlen, type, &data, sizeof(__u16));
 827 }
 828
 829 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
 830 {
 831         return addattr_l(n, maxlen, type, &data, sizeof(__u32));
 832 }
 833
 834 int addattr64(struct nlmsghdr *n, int maxlen, int type, __u64 data)
 835 {
 836         return addattr_l(n, maxlen, type, &data, sizeof(__u64));
 837 }
 838
 839 int addattrstrz(struct nlmsghdr *n, int maxlen, int type, const char *str)
 840 {
 841         return addattr_l(n, maxlen, type, str, strlen(str)+1);
 842 }
 843
 844 int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
 845               int alen)
 846 {
 847         int len = RTA_LENGTH(alen);
 848         struct rtattr *rta;
 849
 850         if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
 851                 fprintf(stderr,
 852                         "addattr_l ERROR: message exceeded bound of %d\n",
 853                         maxlen);
 854                 return -1;
 855         }
 856         rta = NLMSG_TAIL(n);
 857         rta->rta_type = type;
 858         rta->rta_len = len;
 859         memcpy(RTA_DATA(rta), data, alen);
 860         n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
 861         return 0;
 862 }
 863
 864 int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len)
 865 {
 866         if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) {
 867                 fprintf(stderr,
 868                         "addraw_l ERROR: message exceeded bound of %d\n",
 869                         maxlen);
 870                 return -1;
 871         }
 872
 873         memcpy(NLMSG_TAIL(n), data, len);
 874         memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len);
 875         n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len);
 876         return 0;
 877 }
 878
 879 struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type)
 880 {
 881         struct rtattr *nest = NLMSG_TAIL(n);
 882
 883         addattr_l(n, maxlen, type, NULL, 0);
 884         return nest;
 885 }
 886
 887 int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest)
 888 {
 889         nest->rta_len = (void *)NLMSG_TAIL(n) - (void *)nest;
 890         return n->nlmsg_len;
 891 }
 892
 893 struct rtattr *addattr_nest_compat(struct nlmsghdr *n, int maxlen, int type,
 894                                    const void *data, int len)
 895 {
 896         struct rtattr *start = NLMSG_TAIL(n);
 897
 898         addattr_l(n, maxlen, type, data, len);
 899         addattr_nest(n, maxlen, type);
 900         return start;
 901 }
 902
 903 int addattr_nest_compat_end(struct nlmsghdr *n, struct rtattr *start)
 904 {
 905         struct rtattr *nest = (void *)start + NLMSG_ALIGN(start->rta_len);
 906
 907         start->rta_len = (void *)NLMSG_TAIL(n) - (void *)start;
 908         addattr_nest_end(n, nest);
 909         return n->nlmsg_len;
 910 }
 911
 912 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
 913 {
 914         int len = RTA_LENGTH(4);
 915         struct rtattr *subrta;
 916
 917         if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
 918                 fprintf(stderr,
 919                         "rta_addattr32: Error! max allowed bound %d exceeded\n",
 920                         maxlen);
 921                 return -1;
 922         }
 923         subrta = (struct rtattr *)(((char *)rta) + RTA_ALIGN(rta->rta_len));
 924         subrta->rta_type = type;
 925         subrta->rta_len = len;
 926         memcpy(RTA_DATA(subrta), &data, 4);
 927         rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
 928         return 0;
 929 }
 930
 931 int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
 932                   const void *data, int alen)
 933 {
 934         struct rtattr *subrta;
 935         int len = RTA_LENGTH(alen);
 936
 937         if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen) {
 938                 fprintf(stderr,
 939                         "rta_addattr_l: Error! max allowed bound %d exceeded\n",
 940                         maxlen);
 941                 return -1;
 942         }
 943         subrta = (struct rtattr *)(((char *)rta) + RTA_ALIGN(rta->rta_len));
 944         subrta->rta_type = type;
 945         subrta->rta_len = len;
 946         memcpy(RTA_DATA(subrta), data, alen);
 947         rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len);
 948         return 0;
 949 }
 950
 951 int rta_addattr8(struct rtattr *rta, int maxlen, int type, __u8 data)
 952 {
 953         return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u8));
 954 }
 955
 956 int rta_addattr16(struct rtattr *rta, int maxlen, int type, __u16 data)
 957 {
 958         return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u16));
 959 }
 960
 961 int rta_addattr64(struct rtattr *rta, int maxlen, int type, __u64 data)
 962 {
 963         return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u64));
 964 }
 965
 966 struct rtattr *rta_nest(struct rtattr *rta, int maxlen, int type)
 967 {
 968         struct rtattr *nest = RTA_TAIL(rta);
 969
 970         rta_addattr_l(rta, maxlen, type, NULL, 0);
 971
 972         return nest;
 973 }
 974
 975 int rta_nest_end(struct rtattr *rta, struct rtattr *nest)
 976 {
 977         nest->rta_len = (void *)RTA_TAIL(rta) - (void *)nest;
 978
 979         return rta->rta_len;
 980 }
 981
 982 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
 983 {
 984         return parse_rtattr_flags(tb, max, rta, len, 0);
 985 }
 986
 987 int parse_rtattr_flags(struct rtattr *tb[], int max, struct rtattr *rta,
 988                        int len, unsigned short flags)
 989 {
 990         unsigned short type;
 991
 992         memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
 993         while (RTA_OK(rta, len)) {
 994                 type = rta->rta_type & ~flags;
 995                 if ((type <= max) && (!tb[type]))
 996                         tb[type] = rta;
 997                 rta = RTA_NEXT(rta, len);
 998         }
 999         if (len)
1000                 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n",
1001                         len, rta->rta_len);
1002         return 0;
1003 }
1004
1005 int parse_rtattr_byindex(struct rtattr *tb[], int max,
1006                          struct rtattr *rta, int len)
1007 {
1008         int i = 0;
1009
1010         memset(tb, 0, sizeof(struct rtattr *) * max);
1011         while (RTA_OK(rta, len)) {
1012                 if (rta->rta_type <= max && i < max)
1013                         tb[i++] = rta;
1014                 rta = RTA_NEXT(rta, len);
1015         }
1016         if (len)
1017                 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n",
1018                         len, rta->rta_len);
1019         return i;
1020 }
1021
1022 struct rtattr *parse_rtattr_one(int type, struct rtattr *rta, int len)
1023 {
1024         while (RTA_OK(rta, len)) {
1025                 if (rta->rta_type == type)
1026                         return rta;
1027                 rta = RTA_NEXT(rta, len);
1028         }
1029
1030         if (len)
1031                 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n",
1032                         len, rta->rta_len);
1033         return NULL;
1034 }
1035
1036 int __parse_rtattr_nested_compat(struct rtattr *tb[], int max,
1037                                  struct rtattr *rta,
1038                                  int len)
1039 {
1040         if (RTA_PAYLOAD(rta) < len)
1041                 return -1;
1042         if (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) {
1043                 rta = RTA_DATA(rta) + RTA_ALIGN(len);
1044                 return parse_rtattr_nested(tb, max, rta);
1045         }
1046         memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
1047         return 0;
1048 }