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 <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 #include <linux/fib_rules.h>
  26 #include <linux/if_addrlabel.h>
  27 #include <linux/if_bridge.h>
  28
  29 #include "libnetlink.h"
  30
  31 #define __aligned(x)            __attribute__((aligned(x)))
  32
  33 #ifndef SOL_NETLINK
  34 #define SOL_NETLINK 270
  35 #endif
  36
  37 #ifndef MIN
  38 #define MIN(a, b) ((a) < (b) ? (a) : (b))
  39 #endif
  40
  41 int rcvbuf = 1024 * 1024;
  42
  43 #ifdef HAVE_LIBMNL
  44 #include <libmnl/libmnl.h>
  45
  46 static const enum mnl_attr_data_type extack_policy[NLMSGERR_ATTR_MAX + 1] = {
  47         [NLMSGERR_ATTR_MSG]     = MNL_TYPE_NUL_STRING,
  48         [NLMSGERR_ATTR_OFFS]    = MNL_TYPE_U32,
  49 };
  50
  51 static int err_attr_cb(const struct nlattr *attr, void *data)
  52 {
  53         const struct nlattr **tb = data;
  54         uint16_t type;
  55
  56         if (mnl_attr_type_valid(attr, NLMSGERR_ATTR_MAX) < 0) {
  57                 fprintf(stderr, "Invalid extack attribute\n");
  58                 return MNL_CB_ERROR;
  59         }
  60
  61         type = mnl_attr_get_type(attr);
  62         if (mnl_attr_validate(attr, extack_policy[type]) < 0) {
  63                 fprintf(stderr, "extack attribute %d failed validation\n",
  64                         type);
  65                 return MNL_CB_ERROR;
  66         }
  67
  68         tb[type] = attr;
  69         return MNL_CB_OK;
  70 }
  71
  72 static void print_ext_ack_msg(bool is_err, const char *msg)
  73 {
  74         fprintf(stderr, "%s: %s", is_err ? "Error" : "Warning", msg);
  75         if (msg[strlen(msg) - 1] != '.')
  76                 fprintf(stderr, ".");
  77         fprintf(stderr, "\n");
  78 }
  79
  80 /* dump netlink extended ack error message */
  81 int nl_dump_ext_ack(const struct nlmsghdr *nlh, nl_ext_ack_fn_t errfn)
  82 {
  83         struct nlattr *tb[NLMSGERR_ATTR_MAX + 1] = {};
  84         const struct nlmsgerr *err = mnl_nlmsg_get_payload(nlh);
  85         const struct nlmsghdr *err_nlh = NULL;
  86         unsigned int hlen = sizeof(*err);
  87         const char *msg = NULL;
  88         uint32_t off = 0;
  89
  90         /* no TLVs, nothing to do here */
  91         if (!(nlh->nlmsg_flags & NLM_F_ACK_TLVS))
  92                 return 0;
  93
  94         /* if NLM_F_CAPPED is set then the inner err msg was capped */
  95         if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
  96                 hlen += mnl_nlmsg_get_payload_len(&err->msg);
  97
  98         if (mnl_attr_parse(nlh, hlen, err_attr_cb, tb) != MNL_CB_OK)
  99                 return 0;
 100
 101         if (tb[NLMSGERR_ATTR_MSG])
 102                 msg = mnl_attr_get_str(tb[NLMSGERR_ATTR_MSG]);
 103
 104         if (tb[NLMSGERR_ATTR_OFFS]) {
 105                 off = mnl_attr_get_u32(tb[NLMSGERR_ATTR_OFFS]);
 106
 107                 if (off > nlh->nlmsg_len) {
 108                         fprintf(stderr,
 109                                 "Invalid offset for NLMSGERR_ATTR_OFFS\n");
 110                         off = 0;
 111                 } else if (!(nlh->nlmsg_flags & NLM_F_CAPPED))
 112                         err_nlh = &err->msg;
 113         }
 114
 115         if (errfn)
 116                 return errfn(msg, off, err_nlh);
 117
 118         if (msg && *msg != '\0') {
 119                 bool is_err = !!err->error;
 120
 121                 print_ext_ack_msg(is_err, msg);
 122                 return is_err ? 1 : 0;
 123         }
 124
 125         return 0;
 126 }
 127
 128 static int nl_dump_ext_ack_done(const struct nlmsghdr *nlh, int error)
 129 {
 130         struct nlattr *tb[NLMSGERR_ATTR_MAX + 1] = {};
 131         unsigned int hlen = sizeof(int);
 132         const char *msg = NULL;
 133
 134         if (mnl_attr_parse(nlh, hlen, err_attr_cb, tb) != MNL_CB_OK)
 135                 return 0;
 136
 137         if (tb[NLMSGERR_ATTR_MSG])
 138                 msg = mnl_attr_get_str(tb[NLMSGERR_ATTR_MSG]);
 139
 140         if (msg && *msg != '\0') {
 141                 bool is_err = !!error;
 142
 143                 print_ext_ack_msg(is_err, msg);
 144                 return is_err ? 1 : 0;
 145         }
 146
 147         return 0;
 148 }
 149 #else
 150 #warning "libmnl required for error support"
 151
 152 /* No extended error ack without libmnl */
 153 int nl_dump_ext_ack(const struct nlmsghdr *nlh, nl_ext_ack_fn_t errfn)
 154 {
 155         return 0;
 156 }
 157
 158 static int nl_dump_ext_ack_done(const struct nlmsghdr *nlh, int error)
 159 {
 160         return 0;
 161 }
 162 #endif
 163
 164 /* Older kernels may not support strict dump and filtering */
 165 void rtnl_set_strict_dump(struct rtnl_handle *rth)
 166 {
 167         int one = 1;
 168
 169         if (setsockopt(rth->fd, SOL_NETLINK, NETLINK_GET_STRICT_CHK,
 170                        &one, sizeof(one)) < 0)
 171                 return;
 172
 173         rth->flags |= RTNL_HANDLE_F_STRICT_CHK;
 174 }
 175
 176 void rtnl_close(struct rtnl_handle *rth)
 177 {
 178         if (rth->fd >= 0) {
 179                 close(rth->fd);
 180                 rth->fd = -1;
 181         }
 182 }
 183
 184 int rtnl_open_byproto(struct rtnl_handle *rth, unsigned int subscriptions,
 185                       int protocol)
 186 {
 187         socklen_t addr_len;
 188         int sndbuf = 32768;
 189         int one = 1;
 190
 191         memset(rth, 0, sizeof(*rth));
 192
 193         rth->proto = protocol;
 194         rth->fd = socket(AF_NETLINK, SOCK_RAW | SOCK_CLOEXEC, protocol);
 195         if (rth->fd < 0) {
 196                 perror("Cannot open netlink socket");
 197                 return -1;
 198         }
 199
 200         if (setsockopt(rth->fd, SOL_SOCKET, SO_SNDBUF,
 201                        &sndbuf, sizeof(sndbuf)) < 0) {
 202                 perror("SO_SNDBUF");
 203                 return -1;
 204         }
 205
 206         if (setsockopt(rth->fd, SOL_SOCKET, SO_RCVBUF,
 207                        &rcvbuf, sizeof(rcvbuf)) < 0) {
 208                 perror("SO_RCVBUF");
 209                 return -1;
 210         }
 211
 212         /* Older kernels may no support extended ACK reporting */
 213         setsockopt(rth->fd, SOL_NETLINK, NETLINK_EXT_ACK,
 214                    &one, sizeof(one));
 215
 216         memset(&rth->local, 0, sizeof(rth->local));
 217         rth->local.nl_family = AF_NETLINK;
 218         rth->local.nl_groups = subscriptions;
 219
 220         if (bind(rth->fd, (struct sockaddr *)&rth->local,
 221                  sizeof(rth->local)) < 0) {
 222                 perror("Cannot bind netlink socket");
 223                 return -1;
 224         }
 225         addr_len = sizeof(rth->local);
 226         if (getsockname(rth->fd, (struct sockaddr *)&rth->local,
 227                         &addr_len) < 0) {
 228                 perror("Cannot getsockname");
 229                 return -1;
 230         }
 231         if (addr_len != sizeof(rth->local)) {
 232                 fprintf(stderr, "Wrong address length %d\n", addr_len);
 233                 return -1;
 234         }
 235         if (rth->local.nl_family != AF_NETLINK) {
 236                 fprintf(stderr, "Wrong address family %d\n",
 237                         rth->local.nl_family);
 238                 return -1;
 239         }
 240         rth->seq = time(NULL);
 241         return 0;
 242 }
 243
 244 int rtnl_open(struct rtnl_handle *rth, unsigned int subscriptions)
 245 {
 246         return rtnl_open_byproto(rth, subscriptions, NETLINK_ROUTE);
 247 }
 248
 249 int rtnl_addrdump_req(struct rtnl_handle *rth, int family,
 250                       req_filter_fn_t filter_fn)
 251 {
 252         struct {
 253                 struct nlmsghdr nlh;
 254                 struct ifaddrmsg ifm;
 255                 char buf[128];
 256         } req = {
 257                 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg)),
 258                 .nlh.nlmsg_type = RTM_GETADDR,
 259                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 260                 .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 261                 .ifm.ifa_family = family,
 262         };
 263
 264         if (filter_fn) {
 265                 int err;
 266
 267                 err = filter_fn(&req.nlh, sizeof(req));
 268                 if (err)
 269                         return err;
 270         }
 271
 272         return send(rth->fd, &req, sizeof(req), 0);
 273 }
 274
 275 int rtnl_addrlbldump_req(struct rtnl_handle *rth, int family)
 276 {
 277         struct {
 278                 struct nlmsghdr nlh;
 279                 struct ifaddrlblmsg ifal;
 280         } req = {
 281                 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrlblmsg)),
 282                 .nlh.nlmsg_type = RTM_GETADDRLABEL,
 283                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 284                 .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 285                 .ifal.ifal_family = family,
 286         };
 287
 288         return send(rth->fd, &req, sizeof(req), 0);
 289 }
 290
 291 int rtnl_routedump_req(struct rtnl_handle *rth, int family,
 292                        req_filter_fn_t filter_fn)
 293 {
 294         struct {
 295                 struct nlmsghdr nlh;
 296                 struct rtmsg rtm;
 297                 char buf[128];
 298         } req = {
 299                 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)),
 300                 .nlh.nlmsg_type = RTM_GETROUTE,
 301                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 302                 .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 303                 .rtm.rtm_family = family,
 304         };
 305
 306         if (filter_fn) {
 307                 int err;
 308
 309                 err = filter_fn(&req.nlh, sizeof(req));
 310                 if (err)
 311                         return err;
 312         }
 313
 314         return send(rth->fd, &req, sizeof(req), 0);
 315 }
 316
 317 int rtnl_ruledump_req(struct rtnl_handle *rth, int family)
 318 {
 319         struct {
 320                 struct nlmsghdr nlh;
 321                 struct fib_rule_hdr frh;
 322         } req = {
 323                 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct fib_rule_hdr)),
 324                 .nlh.nlmsg_type = RTM_GETRULE,
 325                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 326                 .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 327                 .frh.family = family
 328         };
 329
 330         return send(rth->fd, &req, sizeof(req), 0);
 331 }
 332
 333 int rtnl_neighdump_req(struct rtnl_handle *rth, int family,
 334                        req_filter_fn_t filter_fn)
 335 {
 336         struct {
 337                 struct nlmsghdr nlh;
 338                 struct ndmsg ndm;
 339                 char buf[256];
 340         } req = {
 341                 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg)),
 342                 .nlh.nlmsg_type = RTM_GETNEIGH,
 343                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 344                 .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 345                 .ndm.ndm_family = family,
 346         };
 347
 348         if (filter_fn) {
 349                 int err;
 350
 351                 err = filter_fn(&req.nlh, sizeof(req));
 352                 if (err)
 353                         return err;
 354         }
 355
 356         return send(rth->fd, &req, sizeof(req), 0);
 357 }
 358
 359 int rtnl_neightbldump_req(struct rtnl_handle *rth, int family)
 360 {
 361         struct {
 362                 struct nlmsghdr nlh;
 363                 struct ndtmsg ndtmsg;
 364         } req = {
 365                 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndtmsg)),
 366                 .nlh.nlmsg_type = RTM_GETNEIGHTBL,
 367                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 368                 .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 369                 .ndtmsg.ndtm_family = family,
 370         };
 371
 372         return send(rth->fd, &req, sizeof(req), 0);
 373 }
 374
 375 int rtnl_mdbdump_req(struct rtnl_handle *rth, int family)
 376 {
 377         struct {
 378                 struct nlmsghdr nlh;
 379                 struct br_port_msg bpm;
 380         } req = {
 381                 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct br_port_msg)),
 382                 .nlh.nlmsg_type = RTM_GETMDB,
 383                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 384                 .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 385                 .bpm.family = family,
 386         };
 387
 388         return send(rth->fd, &req, sizeof(req), 0);
 389 }
 390
 391 int rtnl_netconfdump_req(struct rtnl_handle *rth, int family)
 392 {
 393         struct {
 394                 struct nlmsghdr nlh;
 395                 struct netconfmsg ncm;
 396                 char buf[0] __aligned(NLMSG_ALIGNTO);
 397         } req = {
 398                 .nlh.nlmsg_len = NLMSG_LENGTH(NLMSG_ALIGN(sizeof(struct netconfmsg))),
 399                 .nlh.nlmsg_type = RTM_GETNETCONF,
 400                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 401                 .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 402                 .ncm.ncm_family = family,
 403         };
 404
 405         return send(rth->fd, &req, sizeof(req), 0);
 406 }
 407
 408 int rtnl_nsiddump_req(struct rtnl_handle *rth, int family)
 409 {
 410         struct {
 411                 struct nlmsghdr nlh;
 412                 struct rtgenmsg rtm;
 413                 char buf[0] __aligned(NLMSG_ALIGNTO);
 414         } req = {
 415                 .nlh.nlmsg_len = NLMSG_LENGTH(NLMSG_ALIGN(sizeof(struct rtgenmsg))),
 416                 .nlh.nlmsg_type = RTM_GETNSID,
 417                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 418                 .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 419                 .rtm.rtgen_family = family,
 420         };
 421
 422         return send(rth->fd, &req, sizeof(req), 0);
 423 }
 424
 425 static int __rtnl_linkdump_req(struct rtnl_handle *rth, int family)
 426 {
 427         struct {
 428                 struct nlmsghdr nlh;
 429                 struct ifinfomsg ifm;
 430         } req = {
 431                 .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
 432                 .nlh.nlmsg_type = RTM_GETLINK,
 433                 .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 434                 .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 435                 .ifm.ifi_family = family,
 436         };
 437
 438         return send(rth->fd, &req, sizeof(req), 0);
 439 }
 440
 441 int rtnl_linkdump_req(struct rtnl_handle *rth, int family)
 442 {
 443         if (family == AF_UNSPEC)
 444                 return rtnl_linkdump_req_filter(rth, family, RTEXT_FILTER_VF);
 445
 446         return __rtnl_linkdump_req(rth, family);
 447 }
 448
 449 int rtnl_linkdump_req_filter(struct rtnl_handle *rth, int family,
 450                             __u32 filt_mask)
 451 {
 452         if (family == AF_UNSPEC || family == AF_BRIDGE) {
 453                 struct {
 454                         struct nlmsghdr nlh;
 455                         struct ifinfomsg ifm;
 456                         /* attribute has to be NLMSG aligned */
 457                         struct rtattr ext_req __aligned(NLMSG_ALIGNTO);
 458                         __u32 ext_filter_mask;
 459                 } req = {
 460                         .nlh.nlmsg_len = sizeof(req),
 461                         .nlh.nlmsg_type = RTM_GETLINK,
 462                         .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 463                         .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 464                         .ifm.ifi_family = family,
 465                         .ext_req.rta_type = IFLA_EXT_MASK,
 466                         .ext_req.rta_len = RTA_LENGTH(sizeof(__u32)),
 467                         .ext_filter_mask = filt_mask,
 468                 };
 469
 470                 return send(rth->fd, &req, sizeof(req), 0);
 471         }
 472
 473         return __rtnl_linkdump_req(rth, family);
 474 }
 475
 476 int rtnl_linkdump_req_filter_fn(struct rtnl_handle *rth, int family,
 477                                 req_filter_fn_t filter_fn)
 478 {
 479         if (family == AF_UNSPEC) {
 480                 struct {
 481                         struct nlmsghdr nlh;
 482                         struct ifinfomsg ifm;
 483                         char buf[1024];
 484                 } req = {
 485                         .nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
 486                         .nlh.nlmsg_type = RTM_GETLINK,
 487                         .nlh.nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 488                         .nlh.nlmsg_seq = rth->dump = ++rth->seq,
 489                         .ifm.ifi_family = family,
 490                 };
 491                 int err;
 492
 493                 if (!filter_fn)
 494                         return -EINVAL;
 495
 496                 err = filter_fn(&req.nlh, sizeof(req));
 497                 if (err)
 498                         return err;
 499
 500                 return send(rth->fd, &req, req.nlh.nlmsg_len, 0);
 501         }
 502
 503         return __rtnl_linkdump_req(rth, family);
 504 }
 505
 506 int rtnl_statsdump_req_filter(struct rtnl_handle *rth, int fam, __u32 filt_mask)
 507 {
 508         struct {
 509                 struct nlmsghdr nlh;
 510                 struct if_stats_msg ifsm;
 511         } req;
 512
 513         memset(&req, 0, sizeof(req));
 514         req.nlh.nlmsg_len = NLMSG_LENGTH(sizeof(struct if_stats_msg));
 515         req.nlh.nlmsg_type = RTM_GETSTATS;
 516         req.nlh.nlmsg_flags = NLM_F_DUMP|NLM_F_REQUEST;
 517         req.nlh.nlmsg_pid = 0;
 518         req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
 519         req.ifsm.family = fam;
 520         req.ifsm.filter_mask = filt_mask;
 521
 522         return send(rth->fd, &req, sizeof(req), 0);
 523 }
 524
 525 int rtnl_send(struct rtnl_handle *rth, const void *buf, int len)
 526 {
 527         return send(rth->fd, buf, len, 0);
 528 }
 529
 530 int rtnl_send_check(struct rtnl_handle *rth, const void *buf, int len)
 531 {
 532         struct nlmsghdr *h;
 533         int status;
 534         char resp[1024];
 535
 536         status = send(rth->fd, buf, len, 0);
 537         if (status < 0)
 538                 return status;
 539
 540         /* Check for immediate errors */
 541         status = recv(rth->fd, resp, sizeof(resp), MSG_DONTWAIT|MSG_PEEK);
 542         if (status < 0) {
 543                 if (errno == EAGAIN)
 544                         return 0;
 545                 return -1;
 546         }
 547
 548         for (h = (struct nlmsghdr *)resp; NLMSG_OK(h, status);
 549              h = NLMSG_NEXT(h, status)) {
 550                 if (h->nlmsg_type == NLMSG_ERROR) {
 551                         struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
 552
 553                         if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
 554                                 fprintf(stderr, "ERROR truncated\n");
 555                         else
 556                                 errno = -err->error;
 557                         return -1;
 558                 }
 559         }
 560
 561         return 0;
 562 }
 563
 564 int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
 565 {
 566         struct nlmsghdr nlh = {
 567                 .nlmsg_len = NLMSG_LENGTH(len),
 568                 .nlmsg_type = type,
 569                 .nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST,
 570                 .nlmsg_seq = rth->dump = ++rth->seq,
 571         };
 572         struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
 573         struct iovec iov[2] = {
 574                 { .iov_base = &nlh, .iov_len = sizeof(nlh) },
 575                 { .iov_base = req, .iov_len = len }
 576         };
 577         struct msghdr msg = {
 578                 .msg_name = &nladdr,
 579                 .msg_namelen = sizeof(nladdr),
 580                 .msg_iov = iov,
 581                 .msg_iovlen = 2,
 582         };
 583
 584         return sendmsg(rth->fd, &msg, 0);
 585 }
 586
 587 int rtnl_dump_request_n(struct rtnl_handle *rth, struct nlmsghdr *n)
 588 {
 589         struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
 590         struct iovec iov = {
 591                 .iov_base = n,
 592                 .iov_len = n->nlmsg_len
 593         };
 594         struct msghdr msg = {
 595                 .msg_name = &nladdr,
 596                 .msg_namelen = sizeof(nladdr),
 597                 .msg_iov = &iov,
 598                 .msg_iovlen = 1,
 599         };
 600
 601         n->nlmsg_flags = NLM_F_DUMP|NLM_F_REQUEST;
 602         n->nlmsg_pid = 0;
 603         n->nlmsg_seq = rth->dump = ++rth->seq;
 604
 605         return sendmsg(rth->fd, &msg, 0);
 606 }
 607
 608 static int rtnl_dump_done(struct nlmsghdr *h)
 609 {
 610         int len = *(int *)NLMSG_DATA(h);
 611
 612         if (h->nlmsg_len < NLMSG_LENGTH(sizeof(int))) {
 613                 fprintf(stderr, "DONE truncated\n");
 614                 return -1;
 615         }
 616
 617         if (len < 0) {
 618                 /* check for any messages returned from kernel */
 619                 if (nl_dump_ext_ack_done(h, len))
 620                         return len;
 621
 622                 errno = -len;
 623                 switch (errno) {
 624                 case ENOENT:
 625                 case EOPNOTSUPP:
 626                         return -1;
 627                 case EMSGSIZE:
 628                         fprintf(stderr,
 629                                 "Error: Buffer too small for object.\n");
 630                         break;
 631                 default:
 632                         perror("RTNETLINK answers");
 633                 }
 634                 return len;
 635         }
 636
 637         /* check for any messages returned from kernel */
 638         nl_dump_ext_ack(h, NULL);
 639
 640         return 0;
 641 }
 642
 643 static void rtnl_dump_error(const struct rtnl_handle *rth,
 644                             struct nlmsghdr *h)
 645 {
 646
 647         if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
 648                 fprintf(stderr, "ERROR truncated\n");
 649         } else {
 650                 const struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
 651
 652                 errno = -err->error;
 653                 if (rth->proto == NETLINK_SOCK_DIAG &&
 654                     (errno == ENOENT ||
 655                      errno == EOPNOTSUPP))
 656                         return;
 657
 658                 if (!(rth->flags & RTNL_HANDLE_F_SUPPRESS_NLERR))
 659                         perror("RTNETLINK answers");
 660         }
 661 }
 662
 663 static int __rtnl_recvmsg(int fd, struct msghdr *msg, int flags)
 664 {
 665         int len;
 666
 667         do {
 668                 len = recvmsg(fd, msg, flags);
 669         } while (len < 0 && (errno == EINTR || errno == EAGAIN));
 670
 671         if (len < 0) {
 672                 fprintf(stderr, "netlink receive error %s (%d)\n",
 673                         strerror(errno), errno);
 674                 return -errno;
 675         }
 676
 677         if (len == 0) {
 678                 fprintf(stderr, "EOF on netlink\n");
 679                 return -ENODATA;
 680         }
 681
 682         return len;
 683 }
 684
 685 static int rtnl_recvmsg(int fd, struct msghdr *msg, char **answer)
 686 {
 687         struct iovec *iov = msg->msg_iov;
 688         char *buf;
 689         int len;
 690
 691         iov->iov_base = NULL;
 692         iov->iov_len = 0;
 693
 694         len = __rtnl_recvmsg(fd, msg, MSG_PEEK | MSG_TRUNC);
 695         if (len < 0)
 696                 return len;
 697
 698         buf = malloc(len);
 699         if (!buf) {
 700                 fprintf(stderr, "malloc error: not enough buffer\n");
 701                 return -ENOMEM;
 702         }
 703
 704         iov->iov_base = buf;
 705         iov->iov_len = len;
 706
 707         len = __rtnl_recvmsg(fd, msg, 0);
 708         if (len < 0) {
 709                 free(buf);
 710                 return len;
 711         }
 712
 713         if (answer)
 714                 *answer = buf;
 715         else
 716                 free(buf);
 717
 718         return len;
 719 }
 720
 721 static int rtnl_dump_filter_l(struct rtnl_handle *rth,
 722                               const struct rtnl_dump_filter_arg *arg)
 723 {
 724         struct sockaddr_nl nladdr;
 725         struct iovec iov;
 726         struct msghdr msg = {
 727                 .msg_name = &nladdr,
 728                 .msg_namelen = sizeof(nladdr),
 729                 .msg_iov = &iov,
 730                 .msg_iovlen = 1,
 731         };
 732         char *buf;
 733         int dump_intr = 0;
 734
 735         while (1) {
 736                 int status;
 737                 const struct rtnl_dump_filter_arg *a;
 738                 int found_done = 0;
 739                 int msglen = 0;
 740
 741                 status = rtnl_recvmsg(rth->fd, &msg, &buf);
 742                 if (status < 0)
 743                         return status;
 744
 745                 if (rth->dump_fp)
 746                         fwrite(buf, 1, NLMSG_ALIGN(status), rth->dump_fp);
 747
 748                 for (a = arg; a->filter; a++) {
 749                         struct nlmsghdr *h = (struct nlmsghdr *)buf;
 750
 751                         msglen = status;
 752
 753                         while (NLMSG_OK(h, msglen)) {
 754                                 int err = 0;
 755
 756                                 h->nlmsg_flags &= ~a->nc_flags;
 757
 758                                 if (nladdr.nl_pid != 0 ||
 759                                     h->nlmsg_pid != rth->local.nl_pid ||
 760                                     h->nlmsg_seq != rth->dump)
 761                                         goto skip_it;
 762
 763                                 if (h->nlmsg_flags & NLM_F_DUMP_INTR)
 764                                         dump_intr = 1;
 765
 766                                 if (h->nlmsg_type == NLMSG_DONE) {
 767                                         err = rtnl_dump_done(h);
 768                                         if (err < 0) {
 769                                                 free(buf);
 770                                                 return -1;
 771                                         }
 772
 773                                         found_done = 1;
 774                                         break; /* process next filter */
 775                                 }
 776
 777                                 if (h->nlmsg_type == NLMSG_ERROR) {
 778                                         rtnl_dump_error(rth, h);
 779                                         free(buf);
 780                                         return -1;
 781                                 }
 782
 783                                 if (!rth->dump_fp) {
 784                                         err = a->filter(h, a->arg1);
 785                                         if (err < 0) {
 786                                                 free(buf);
 787                                                 return err;
 788                                         }
 789                                 }
 790
 791 skip_it:
 792                                 h = NLMSG_NEXT(h, msglen);
 793                         }
 794                 }
 795                 free(buf);
 796
 797                 if (found_done) {
 798                         if (dump_intr)
 799                                 fprintf(stderr,
 800                                         "Dump was interrupted and may be inconsistent.\n");
 801                         return 0;
 802                 }
 803
 804                 if (msg.msg_flags & MSG_TRUNC) {
 805                         fprintf(stderr, "Message truncated\n");
 806                         continue;
 807                 }
 808                 if (msglen) {
 809                         fprintf(stderr, "!!!Remnant of size %d\n", msglen);
 810                         exit(1);
 811                 }
 812         }
 813 }
 814
 815 int rtnl_dump_filter_nc(struct rtnl_handle *rth,
 816                      rtnl_filter_t filter,
 817                      void *arg1, __u16 nc_flags)
 818 {
 819         const struct rtnl_dump_filter_arg a[2] = {
 820                 { .filter = filter, .arg1 = arg1, .nc_flags = nc_flags, },
 821                 { .filter = NULL,   .arg1 = NULL, .nc_flags = 0, },
 822         };
 823
 824         return rtnl_dump_filter_l(rth, a);
 825 }
 826
 827 static void rtnl_talk_error(struct nlmsghdr *h, struct nlmsgerr *err,
 828                             nl_ext_ack_fn_t errfn)
 829 {
 830         if (nl_dump_ext_ack(h, errfn))
 831                 return;
 832
 833         fprintf(stderr, "RTNETLINK answers: %s\n",
 834                 strerror(-err->error));
 835 }
 836
 837
 838 static int __rtnl_talk_iov(struct rtnl_handle *rtnl, struct iovec *iov,
 839                            size_t iovlen, struct nlmsghdr **answer,
 840                            bool show_rtnl_err, nl_ext_ack_fn_t errfn)
 841 {
 842         struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
 843         struct iovec riov;
 844         struct msghdr msg = {
 845                 .msg_name = &nladdr,
 846                 .msg_namelen = sizeof(nladdr),
 847                 .msg_iov = iov,
 848                 .msg_iovlen = iovlen,
 849         };
 850         unsigned int seq = 0;
 851         struct nlmsghdr *h;
 852         int i, status;
 853         char *buf;
 854
 855         for (i = 0; i < iovlen; i++) {
 856                 h = iov[i].iov_base;
 857                 h->nlmsg_seq = seq = ++rtnl->seq;
 858                 if (answer == NULL)
 859                         h->nlmsg_flags |= NLM_F_ACK;
 860         }
 861
 862         status = sendmsg(rtnl->fd, &msg, 0);
 863         if (status < 0) {
 864                 perror("Cannot talk to rtnetlink");
 865                 return -1;
 866         }
 867
 868         /* change msg to use the response iov */
 869         msg.msg_iov = &riov;
 870         msg.msg_iovlen = 1;
 871         i = 0;
 872         while (1) {
 873 next:
 874                 status = rtnl_recvmsg(rtnl->fd, &msg, &buf);
 875                 ++i;
 876
 877                 if (status < 0)
 878                         return status;
 879
 880                 if (msg.msg_namelen != sizeof(nladdr)) {
 881                         fprintf(stderr,
 882                                 "sender address length == %d\n",
 883                                 msg.msg_namelen);
 884                         exit(1);
 885                 }
 886                 for (h = (struct nlmsghdr *)buf; status >= sizeof(*h); ) {
 887                         int len = h->nlmsg_len;
 888                         int l = len - sizeof(*h);
 889
 890                         if (l < 0 || len > status) {
 891                                 if (msg.msg_flags & MSG_TRUNC) {
 892                                         fprintf(stderr, "Truncated message\n");
 893                                         free(buf);
 894                                         return -1;
 895                                 }
 896                                 fprintf(stderr,
 897                                         "!!!malformed message: len=%d\n",
 898                                         len);
 899                                 exit(1);
 900                         }
 901
 902                         if (nladdr.nl_pid != 0 ||
 903                             h->nlmsg_pid != rtnl->local.nl_pid ||
 904                             h->nlmsg_seq > seq || h->nlmsg_seq < seq - iovlen) {
 905                                 /* Don't forget to skip that message. */
 906                                 status -= NLMSG_ALIGN(len);
 907                                 h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
 908                                 continue;
 909                         }
 910
 911                         if (h->nlmsg_type == NLMSG_ERROR) {
 912                                 struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(h);
 913                                 int error = err->error;
 914
 915                                 if (l < sizeof(struct nlmsgerr)) {
 916                                         fprintf(stderr, "ERROR truncated\n");
 917                                         free(buf);
 918                                         return -1;
 919                                 }
 920
 921                                 if (!error) {
 922                                         /* check messages from kernel */
 923                                         nl_dump_ext_ack(h, errfn);
 924                                 } else {
 925                                         errno = -error;
 926
 927                                         if (rtnl->proto != NETLINK_SOCK_DIAG &&
 928                                             show_rtnl_err)
 929                                                 rtnl_talk_error(h, err, errfn);
 930                                 }
 931
 932                                 if (answer)
 933                                         *answer = (struct nlmsghdr *)buf;
 934                                 else
 935                                         free(buf);
 936
 937                                 if (i < iovlen)
 938                                         goto next;
 939                                 return error ? -i : 0;
 940                         }
 941
 942                         if (answer) {
 943                                 *answer = (struct nlmsghdr *)buf;
 944                                 return 0;
 945                         }
 946
 947                         fprintf(stderr, "Unexpected reply!!!\n");
 948
 949                         status -= NLMSG_ALIGN(len);
 950                         h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
 951                 }
 952                 free(buf);
 953
 954                 if (msg.msg_flags & MSG_TRUNC) {
 955                         fprintf(stderr, "Message truncated\n");
 956                         continue;
 957                 }
 958
 959                 if (status) {
 960                         fprintf(stderr, "!!!Remnant of size %d\n", status);
 961                         exit(1);
 962                 }
 963         }
 964 }
 965
 966 static int __rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
 967                        struct nlmsghdr **answer,
 968                        bool show_rtnl_err, nl_ext_ack_fn_t errfn)
 969 {
 970         struct iovec iov = {
 971                 .iov_base = n,
 972                 .iov_len = n->nlmsg_len
 973         };
 974
 975         return __rtnl_talk_iov(rtnl, &iov, 1, answer, show_rtnl_err, errfn);
 976 }
 977
 978 int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n,
 979               struct nlmsghdr **answer)
 980 {
 981         return __rtnl_talk(rtnl, n, answer, true, NULL);
 982 }
 983
 984 int rtnl_talk_iov(struct rtnl_handle *rtnl, struct iovec *iovec, size_t iovlen,
 985                   struct nlmsghdr **answer)
 986 {
 987         return __rtnl_talk_iov(rtnl, iovec, iovlen, answer, true, NULL);
 988 }
 989
 990 int rtnl_talk_suppress_rtnl_errmsg(struct rtnl_handle *rtnl, struct nlmsghdr *n,
 991                                    struct nlmsghdr **answer)
 992 {
 993         return __rtnl_talk(rtnl, n, answer, false, NULL);
 994 }
 995
 996 int rtnl_listen_all_nsid(struct rtnl_handle *rth)
 997 {
 998         unsigned int on = 1;
 999
1000         if (setsockopt(rth->fd, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, &on,
1001                        sizeof(on)) < 0) {
1002                 perror("NETLINK_LISTEN_ALL_NSID");
1003                 return -1;
1004         }
1005         rth->flags |= RTNL_HANDLE_F_LISTEN_ALL_NSID;
1006         return 0;
1007 }
1008
1009 int rtnl_listen(struct rtnl_handle *rtnl,
1010                 rtnl_listen_filter_t handler,
1011                 void *jarg)
1012 {
1013         int status;
1014         struct nlmsghdr *h;
1015         struct sockaddr_nl nladdr = { .nl_family = AF_NETLINK };
1016         struct iovec iov;
1017         struct msghdr msg = {
1018                 .msg_name = &nladdr,
1019                 .msg_namelen = sizeof(nladdr),
1020                 .msg_iov = &iov,
1021                 .msg_iovlen = 1,
1022         };
1023         char   buf[16384];
1024         char   cmsgbuf[BUFSIZ];
1025
1026         if (rtnl->flags & RTNL_HANDLE_F_LISTEN_ALL_NSID) {
1027                 msg.msg_control = &cmsgbuf;
1028                 msg.msg_controllen = sizeof(cmsgbuf);
1029         }
1030
1031         iov.iov_base = buf;
1032         while (1) {
1033                 struct rtnl_ctrl_data ctrl;
1034                 struct cmsghdr *cmsg;
1035
1036                 iov.iov_len = sizeof(buf);
1037                 status = recvmsg(rtnl->fd, &msg, 0);
1038
1039                 if (status < 0) {
1040                         if (errno == EINTR || errno == EAGAIN)
1041                                 continue;
1042                         fprintf(stderr, "netlink receive error %s (%d)\n",
1043                                 strerror(errno), errno);
1044                         if (errno == ENOBUFS)
1045                                 continue;
1046                         return -1;
1047                 }
1048                 if (status == 0) {
1049                         fprintf(stderr, "EOF on netlink\n");
1050                         return -1;
1051                 }
1052                 if (msg.msg_namelen != sizeof(nladdr)) {
1053                         fprintf(stderr,
1054                                 "Sender address length == %d\n",
1055                                 msg.msg_namelen);
1056                         exit(1);
1057                 }
1058
1059                 if (rtnl->flags & RTNL_HANDLE_F_LISTEN_ALL_NSID) {
1060                         memset(&ctrl, 0, sizeof(ctrl));
1061                         ctrl.nsid = -1;
1062                         for (cmsg = CMSG_FIRSTHDR(&msg); cmsg;
1063                              cmsg = CMSG_NXTHDR(&msg, cmsg))
1064                                 if (cmsg->cmsg_level == SOL_NETLINK &&
1065                                     cmsg->cmsg_type == NETLINK_LISTEN_ALL_NSID &&
1066                                     cmsg->cmsg_len == CMSG_LEN(sizeof(int))) {
1067                                         int *data = (int *)CMSG_DATA(cmsg);
1068
1069                                         ctrl.nsid = *data;
1070                                 }
1071                 }
1072
1073                 for (h = (struct nlmsghdr *)buf; status >= sizeof(*h); ) {
1074                         int err;
1075                         int len = h->nlmsg_len;
1076                         int l = len - sizeof(*h);
1077
1078                         if (l < 0 || len > status) {
1079                                 if (msg.msg_flags & MSG_TRUNC) {
1080                                         fprintf(stderr, "Truncated message\n");
1081                                         return -1;
1082                                 }
1083                                 fprintf(stderr,
1084                                         "!!!malformed message: len=%d\n",
1085                                         len);
1086                                 exit(1);
1087                         }
1088
1089                         err = handler(&ctrl, h, jarg);
1090                         if (err < 0)
1091                                 return err;
1092
1093                         status -= NLMSG_ALIGN(len);
1094                         h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
1095                 }
1096                 if (msg.msg_flags & MSG_TRUNC) {
1097                         fprintf(stderr, "Message truncated\n");
1098                         continue;
1099                 }
1100                 if (status) {
1101                         fprintf(stderr, "!!!Remnant of size %d\n", status);
1102                         exit(1);
1103                 }
1104         }
1105 }
1106
1107 int rtnl_from_file(FILE *rtnl, rtnl_listen_filter_t handler,
1108                    void *jarg)
1109 {
1110         int status;
1111         char buf[16384];
1112         struct nlmsghdr *h = (struct nlmsghdr *)buf;
1113
1114         while (1) {
1115                 int err, len;
1116                 int l;
1117
1118                 status = fread(&buf, 1, sizeof(*h), rtnl);
1119
1120                 if (status < 0) {
1121                         if (errno == EINTR)
1122                                 continue;
1123                         perror("rtnl_from_file: fread");
1124                         return -1;
1125                 }
1126                 if (status == 0)
1127                         return 0;
1128
1129                 len = h->nlmsg_len;
1130                 l = len - sizeof(*h);
1131
1132                 if (l < 0 || len > sizeof(buf)) {
1133                         fprintf(stderr, "!!!malformed message: len=%d @%lu\n",
1134                                 len, ftell(rtnl));
1135                         return -1;
1136                 }
1137
1138                 status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
1139
1140                 if (status < 0) {
1141                         perror("rtnl_from_file: fread");
1142                         return -1;
1143                 }
1144                 if (status < l) {
1145                         fprintf(stderr, "rtnl-from_file: truncated message\n");
1146                         return -1;
1147                 }
1148
1149                 err = handler(NULL, h, jarg);
1150                 if (err < 0)
1151                         return err;
1152         }
1153 }
1154
1155 int addattr(struct nlmsghdr *n, int maxlen, int type)
1156 {
1157         return addattr_l(n, maxlen, type, NULL, 0);
1158 }
1159
1160 int addattr8(struct nlmsghdr *n, int maxlen, int type, __u8 data)
1161 {
1162         return addattr_l(n, maxlen, type, &data, sizeof(__u8));
1163 }
1164
1165 int addattr16(struct nlmsghdr *n, int maxlen, int type, __u16 data)
1166 {
1167         return addattr_l(n, maxlen, type, &data, sizeof(__u16));
1168 }
1169
1170 int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
1171 {
1172         return addattr_l(n, maxlen, type, &data, sizeof(__u32));
1173 }
1174
1175 int addattr64(struct nlmsghdr *n, int maxlen, int type, __u64 data)
1176 {
1177         return addattr_l(n, maxlen, type, &data, sizeof(__u64));
1178 }
1179
1180 int addattrstrz(struct nlmsghdr *n, int maxlen, int type, const char *str)
1181 {
1182         return addattr_l(n, maxlen, type, str, strlen(str)+1);
1183 }
1184
1185 int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
1186               int alen)
1187 {
1188         int len = RTA_LENGTH(alen);
1189         struct rtattr *rta;
1190
1191         if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
1192                 fprintf(stderr,
1193                         "addattr_l ERROR: message exceeded bound of %d\n",
1194                         maxlen);
1195                 return -1;
1196         }
1197         rta = NLMSG_TAIL(n);
1198         rta->rta_type = type;
1199         rta->rta_len = len;
1200         if (alen)
1201                 memcpy(RTA_DATA(rta), data, alen);
1202         n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
1203         return 0;
1204 }
1205
1206 int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len)
1207 {
1208         if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) {
1209                 fprintf(stderr,
1210                         "addraw_l ERROR: message exceeded bound of %d\n",
1211                         maxlen);
1212                 return -1;
1213         }
1214
1215         memcpy(NLMSG_TAIL(n), data, len);
1216         memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len);
1217         n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len);
1218         return 0;
1219 }
1220
1221 struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type)
1222 {
1223         struct rtattr *nest = NLMSG_TAIL(n);
1224
1225         addattr_l(n, maxlen, type, NULL, 0);
1226         return nest;
1227 }
1228
1229 int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest)
1230 {
1231         nest->rta_len = (void *)NLMSG_TAIL(n) - (void *)nest;
1232         return n->nlmsg_len;
1233 }
1234
1235 struct rtattr *addattr_nest_compat(struct nlmsghdr *n, int maxlen, int type,
1236                                    const void *data, int len)
1237 {
1238         struct rtattr *start = NLMSG_TAIL(n);
1239
1240         addattr_l(n, maxlen, type, data, len);
1241         addattr_nest(n, maxlen, type);
1242         return start;
1243 }
1244
1245 int addattr_nest_compat_end(struct nlmsghdr *n, struct rtattr *start)
1246 {
1247         struct rtattr *nest = (void *)start + NLMSG_ALIGN(start->rta_len);
1248
1249         start->rta_len = (void *)NLMSG_TAIL(n) - (void *)start;
1250         addattr_nest_end(n, nest);
1251         return n->nlmsg_len;
1252 }
1253
1254 int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
1255 {
1256         int len = RTA_LENGTH(4);
1257         struct rtattr *subrta;
1258
1259         if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
1260                 fprintf(stderr,
1261                         "rta_addattr32: Error! max allowed bound %d exceeded\n",
1262                         maxlen);
1263                 return -1;
1264         }
1265         subrta = (struct rtattr *)(((char *)rta) + RTA_ALIGN(rta->rta_len));
1266         subrta->rta_type = type;
1267         subrta->rta_len = len;
1268         memcpy(RTA_DATA(subrta), &data, 4);
1269         rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
1270         return 0;
1271 }
1272
1273 int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
1274                   const void *data, int alen)
1275 {
1276         struct rtattr *subrta;
1277         int len = RTA_LENGTH(alen);
1278
1279         if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen) {
1280                 fprintf(stderr,
1281                         "rta_addattr_l: Error! max allowed bound %d exceeded\n",
1282                         maxlen);
1283                 return -1;
1284         }
1285         subrta = (struct rtattr *)(((char *)rta) + RTA_ALIGN(rta->rta_len));
1286         subrta->rta_type = type;
1287         subrta->rta_len = len;
1288         if (alen)
1289                 memcpy(RTA_DATA(subrta), data, alen);
1290         rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len);
1291         return 0;
1292 }
1293
1294 int rta_addattr8(struct rtattr *rta, int maxlen, int type, __u8 data)
1295 {
1296         return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u8));
1297 }
1298
1299 int rta_addattr16(struct rtattr *rta, int maxlen, int type, __u16 data)
1300 {
1301         return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u16));
1302 }
1303
1304 int rta_addattr64(struct rtattr *rta, int maxlen, int type, __u64 data)
1305 {
1306         return rta_addattr_l(rta, maxlen, type, &data, sizeof(__u64));
1307 }
1308
1309 struct rtattr *rta_nest(struct rtattr *rta, int maxlen, int type)
1310 {
1311         struct rtattr *nest = RTA_TAIL(rta);
1312
1313         rta_addattr_l(rta, maxlen, type, NULL, 0);
1314
1315         return nest;
1316 }
1317
1318 int rta_nest_end(struct rtattr *rta, struct rtattr *nest)
1319 {
1320         nest->rta_len = (void *)RTA_TAIL(rta) - (void *)nest;
1321
1322         return rta->rta_len;
1323 }
1324
1325 int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
1326 {
1327         return parse_rtattr_flags(tb, max, rta, len, 0);
1328 }
1329
1330 int parse_rtattr_flags(struct rtattr *tb[], int max, struct rtattr *rta,
1331                        int len, unsigned short flags)
1332 {
1333         unsigned short type;
1334
1335         memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
1336         while (RTA_OK(rta, len)) {
1337                 type = rta->rta_type & ~flags;
1338                 if ((type <= max) && (!tb[type]))
1339                         tb[type] = rta;
1340                 rta = RTA_NEXT(rta, len);
1341         }
1342         if (len)
1343                 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n",
1344                         len, rta->rta_len);
1345         return 0;
1346 }
1347
1348 struct rtattr *parse_rtattr_one(int type, struct rtattr *rta, int len)
1349 {
1350         while (RTA_OK(rta, len)) {
1351                 if (rta->rta_type == type)
1352                         return rta;
1353                 rta = RTA_NEXT(rta, len);
1354         }
1355
1356         if (len)
1357                 fprintf(stderr, "!!!Deficit %d, rta_len=%d\n",
1358                         len, rta->rta_len);
1359         return NULL;
1360 }
1361
1362 int __parse_rtattr_nested_compat(struct rtattr *tb[], int max,
1363                                  struct rtattr *rta,
1364                                  int len)
1365 {
1366         if (RTA_PAYLOAD(rta) < len)
1367                 return -1;
1368         if (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) {
1369                 rta = RTA_DATA(rta) + RTA_ALIGN(len);
1370                 return parse_rtattr_nested(tb, max, rta);
1371         }
1372         memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
1373         return 0;
1374 }