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