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