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