src/libsystemd/sd-netlink/netlink-message.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2013 Tom Gundersen <teg@jklm.no>
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <netinet/in.h>
  23 #include <stdbool.h>
  24 #include <unistd.h>
  25
  26 #include "util.h"
  27 #include "socket-util.h"
  28 #include "formats-util.h"
  29 #include "refcnt.h"
  30 #include "missing.h"
  31
  32 #include "sd-netlink.h"
  33 #include "netlink-util.h"
  34 #include "netlink-internal.h"
  35 #include "netlink-types.h"
  36
  37 #define GET_CONTAINER(m, i) ((i) < (m)->n_containers ? (struct rtattr*)((uint8_t*)(m)->hdr + (m)->container_offsets[i]) : NULL)
  38 #define PUSH_CONTAINER(m, new) (m)->container_offsets[(m)->n_containers ++] = (uint8_t*)(new) - (uint8_t*)(m)->hdr;
  39
  40 #define RTA_TYPE(rta) ((rta)->rta_type & NLA_TYPE_MASK)
  41
  42 int message_new_empty(sd_netlink *rtnl, sd_netlink_message **ret) {
  43         sd_netlink_message *m;
  44
  45         assert_return(ret, -EINVAL);
  46
  47         /* Note that 'rtnl' is currently unused, if we start using it internally
  48            we must take care to avoid problems due to mutual references between
  49            buses and their queued messages. See sd-bus.
  50          */
  51
  52         m = new0(sd_netlink_message, 1);
  53         if (!m)
  54                 return -ENOMEM;
  55
  56         m->n_ref = REFCNT_INIT;
  57
  58         m->sealed = false;
  59
  60         *ret = m;
  61
  62         return 0;
  63 }
  64
  65 int message_new(sd_netlink *rtnl, sd_netlink_message **ret, uint16_t type) {
  66         _cleanup_netlink_message_unref_ sd_netlink_message *m = NULL;
  67         const NLType *nl_type;
  68         size_t size;
  69         int r;
  70
  71         r = type_system_get_type(&type_system_root, &nl_type, type);
  72         if (r < 0)
  73                 return r;
  74
  75         if (type_get_type(nl_type) != NETLINK_TYPE_NESTED)
  76                 return -EINVAL;
  77
  78         r = message_new_empty(rtnl, &m);
  79         if (r < 0)
  80                 return r;
  81
  82         size = NLMSG_SPACE(type_get_size(nl_type));
  83
  84         assert(size >= sizeof(struct nlmsghdr));
  85         m->hdr = malloc0(size);
  86         if (!m->hdr)
  87                 return -ENOMEM;
  88
  89         m->hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
  90
  91         type_get_type_system(nl_type, &m->container_type_system[0]);
  92         m->hdr->nlmsg_len = size;
  93         m->hdr->nlmsg_type = type;
  94
  95         *ret = m;
  96         m = NULL;
  97
  98         return 0;
  99 }
 100
 101 int sd_netlink_message_request_dump(sd_netlink_message *m, int dump) {
 102         assert_return(m, -EINVAL);
 103         assert_return(m->hdr, -EINVAL);
 104         assert_return(m->hdr->nlmsg_type == RTM_GETLINK  ||
 105                       m->hdr->nlmsg_type == RTM_GETADDR  ||
 106                       m->hdr->nlmsg_type == RTM_GETROUTE ||
 107                       m->hdr->nlmsg_type == RTM_GETNEIGH,
 108                       -EINVAL);
 109
 110         if (dump)
 111                 m->hdr->nlmsg_flags |= NLM_F_DUMP;
 112         else
 113                 m->hdr->nlmsg_flags &= ~NLM_F_DUMP;
 114
 115         return 0;
 116 }
 117
 118 sd_netlink_message *sd_netlink_message_ref(sd_netlink_message *m) {
 119         if (m)
 120                 assert_se(REFCNT_INC(m->n_ref) >= 2);
 121
 122         return m;
 123 }
 124
 125 sd_netlink_message *sd_netlink_message_unref(sd_netlink_message *m) {
 126         if (m && REFCNT_DEC(m->n_ref) == 0) {
 127                 unsigned i;
 128
 129                 free(m->hdr);
 130
 131                 for (i = 0; i <= m->n_containers; i++)
 132                         free(m->rta_offset_tb[i]);
 133
 134                 sd_netlink_message_unref(m->next);
 135
 136                 free(m);
 137         }
 138
 139         return NULL;
 140 }
 141
 142 int sd_netlink_message_get_type(sd_netlink_message *m, uint16_t *type) {
 143         assert_return(m, -EINVAL);
 144         assert_return(type, -EINVAL);
 145
 146         *type = m->hdr->nlmsg_type;
 147
 148         return 0;
 149 }
 150
 151 int sd_netlink_message_is_broadcast(sd_netlink_message *m) {
 152         assert_return(m, -EINVAL);
 153
 154         return m->broadcast;
 155 }
 156
 157 /* If successful the updated message will be correctly aligned, if
 158    unsuccessful the old message is untouched. */
 159 static int add_rtattr(sd_netlink_message *m, unsigned short type, const void *data, size_t data_length) {
 160         uint32_t rta_length;
 161         size_t message_length, padding_length;
 162         struct nlmsghdr *new_hdr;
 163         struct rtattr *rta;
 164         char *padding;
 165         unsigned i;
 166         int offset;
 167
 168         assert(m);
 169         assert(m->hdr);
 170         assert(!m->sealed);
 171         assert(NLMSG_ALIGN(m->hdr->nlmsg_len) == m->hdr->nlmsg_len);
 172         assert(!data || data_length);
 173
 174         /* get offset of the new attribute */
 175         offset = m->hdr->nlmsg_len;
 176
 177         /* get the size of the new rta attribute (with padding at the end) */
 178         rta_length = RTA_LENGTH(data_length);
 179
 180         /* get the new message size (with padding at the end) */
 181         message_length = offset + RTA_ALIGN(rta_length);
 182
 183         /* realloc to fit the new attribute */
 184         new_hdr = realloc(m->hdr, message_length);
 185         if (!new_hdr)
 186                 return -ENOMEM;
 187         m->hdr = new_hdr;
 188
 189         /* get pointer to the attribute we are about to add */
 190         rta = (struct rtattr *) ((uint8_t *) m->hdr + offset);
 191
 192         /* if we are inside containers, extend them */
 193         for (i = 0; i < m->n_containers; i++)
 194                 GET_CONTAINER(m, i)->rta_len += message_length - offset;
 195
 196         /* fill in the attribute */
 197         rta->rta_type = type;
 198         rta->rta_len = rta_length;
 199         if (data)
 200                 /* we don't deal with the case where the user lies about the type
 201                  * and gives us too little data (so don't do that)
 202                  */
 203                 padding = mempcpy(RTA_DATA(rta), data, data_length);
 204         else {
 205                 /* if no data was passed, make sure we still initialize the padding
 206                    note that we can have data_length > 0 (used by some containers) */
 207                 padding = RTA_DATA(rta);
 208         }
 209
 210         /* make sure also the padding at the end of the message is initialized */
 211         padding_length = (uint8_t*)m->hdr + message_length - (uint8_t*)padding;
 212         memzero(padding, padding_length);
 213
 214         /* update message size */
 215         m->hdr->nlmsg_len = message_length;
 216
 217         return offset;
 218 }
 219
 220 static int message_attribute_has_type(sd_netlink_message *m, size_t *out_size, uint16_t attribute_type, uint16_t data_type) {
 221         const NLType *type;
 222         int r;
 223
 224         assert(m);
 225
 226         r = type_system_get_type(m->container_type_system[m->n_containers], &type, attribute_type);
 227         if (r < 0)
 228                 return r;
 229
 230         if (type_get_type(type) != data_type)
 231                 return -EINVAL;
 232
 233         if (out_size)
 234                 *out_size = type_get_size(type);
 235         return 0;
 236 }
 237
 238 int sd_netlink_message_append_string(sd_netlink_message *m, unsigned short type, const char *data) {
 239         size_t length, size;
 240         int r;
 241
 242         assert_return(m, -EINVAL);
 243         assert_return(!m->sealed, -EPERM);
 244         assert_return(data, -EINVAL);
 245
 246         r = message_attribute_has_type(m, &size, type, NETLINK_TYPE_STRING);
 247         if (r < 0)
 248                 return r;
 249
 250         if (size) {
 251                 length = strnlen(data, size+1);
 252                 if (length > size)
 253                         return -EINVAL;
 254         } else
 255                 length = strlen(data);
 256
 257         r = add_rtattr(m, type, data, length + 1);
 258         if (r < 0)
 259                 return r;
 260
 261         return 0;
 262 }
 263
 264 int sd_netlink_message_append_u8(sd_netlink_message *m, unsigned short type, uint8_t data) {
 265         int r;
 266
 267         assert_return(m, -EINVAL);
 268         assert_return(!m->sealed, -EPERM);
 269
 270         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U8);
 271         if (r < 0)
 272                 return r;
 273
 274         r = add_rtattr(m, type, &data, sizeof(uint8_t));
 275         if (r < 0)
 276                 return r;
 277
 278         return 0;
 279 }
 280
 281
 282 int sd_netlink_message_append_u16(sd_netlink_message *m, unsigned short type, uint16_t data) {
 283         int r;
 284
 285         assert_return(m, -EINVAL);
 286         assert_return(!m->sealed, -EPERM);
 287
 288         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U16);
 289         if (r < 0)
 290                 return r;
 291
 292         r = add_rtattr(m, type, &data, sizeof(uint16_t));
 293         if (r < 0)
 294                 return r;
 295
 296         return 0;
 297 }
 298
 299 int sd_netlink_message_append_u32(sd_netlink_message *m, unsigned short type, uint32_t data) {
 300         int r;
 301
 302         assert_return(m, -EINVAL);
 303         assert_return(!m->sealed, -EPERM);
 304
 305         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U32);
 306         if (r < 0)
 307                 return r;
 308
 309         r = add_rtattr(m, type, &data, sizeof(uint32_t));
 310         if (r < 0)
 311                 return r;
 312
 313         return 0;
 314 }
 315
 316 int sd_netlink_message_append_in_addr(sd_netlink_message *m, unsigned short type, const struct in_addr *data) {
 317         int r;
 318
 319         assert_return(m, -EINVAL);
 320         assert_return(!m->sealed, -EPERM);
 321         assert_return(data, -EINVAL);
 322
 323         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR);
 324         if (r < 0)
 325                 return r;
 326
 327         r = add_rtattr(m, type, data, sizeof(struct in_addr));
 328         if (r < 0)
 329                 return r;
 330
 331         return 0;
 332 }
 333
 334 int sd_netlink_message_append_in6_addr(sd_netlink_message *m, unsigned short type, const struct in6_addr *data) {
 335         int r;
 336
 337         assert_return(m, -EINVAL);
 338         assert_return(!m->sealed, -EPERM);
 339         assert_return(data, -EINVAL);
 340
 341         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR);
 342         if (r < 0)
 343                 return r;
 344
 345         r = add_rtattr(m, type, data, sizeof(struct in6_addr));
 346         if (r < 0)
 347                 return r;
 348
 349         return 0;
 350 }
 351
 352 int sd_netlink_message_append_ether_addr(sd_netlink_message *m, unsigned short type, const struct ether_addr *data) {
 353         int r;
 354
 355         assert_return(m, -EINVAL);
 356         assert_return(!m->sealed, -EPERM);
 357         assert_return(data, -EINVAL);
 358
 359         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_ETHER_ADDR);
 360         if (r < 0)
 361                 return r;
 362
 363         r = add_rtattr(m, type, data, ETH_ALEN);
 364         if (r < 0)
 365                 return r;
 366
 367         return 0;
 368 }
 369
 370 int sd_netlink_message_append_cache_info(sd_netlink_message *m, unsigned short type, const struct ifa_cacheinfo *info) {
 371         int r;
 372
 373         assert_return(m, -EINVAL);
 374         assert_return(!m->sealed, -EPERM);
 375         assert_return(info, -EINVAL);
 376
 377         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_CACHE_INFO);
 378         if (r < 0)
 379                 return r;
 380
 381         r = add_rtattr(m, type, info, sizeof(struct ifa_cacheinfo));
 382         if (r < 0)
 383                 return r;
 384
 385         return 0;
 386 }
 387
 388 int sd_netlink_message_open_container(sd_netlink_message *m, unsigned short type) {
 389         size_t size;
 390         int r;
 391
 392         assert_return(m, -EINVAL);
 393         assert_return(!m->sealed, -EPERM);
 394         assert_return(m->n_containers < RTNL_CONTAINER_DEPTH, -ERANGE);
 395
 396         r = message_attribute_has_type(m, &size, type, NETLINK_TYPE_NESTED);
 397         if (r < 0) {
 398                 const NLTypeSystemUnion *type_system_union;
 399                 int family;
 400
 401                 r = message_attribute_has_type(m, &size, type, NETLINK_TYPE_UNION);
 402                 if (r < 0)
 403                         return r;
 404
 405                 r = sd_rtnl_message_get_family(m, &family);
 406                 if (r < 0)
 407                         return r;
 408
 409                 r = type_system_get_type_system_union(m->container_type_system[m->n_containers], &type_system_union, type);
 410                 if (r < 0)
 411                         return r;
 412
 413                 r = type_system_union_protocol_get_type_system(type_system_union,
 414                                                                &m->container_type_system[m->n_containers + 1],
 415                                                                family);
 416                 if (r < 0)
 417                         return r;
 418         } else {
 419                 r = type_system_get_type_system(m->container_type_system[m->n_containers],
 420                                                 &m->container_type_system[m->n_containers + 1],
 421                                                 type);
 422                 if (r < 0)
 423                         return r;
 424         }
 425
 426         r = add_rtattr(m, type | NLA_F_NESTED, NULL, size);
 427         if (r < 0)
 428                 return r;
 429
 430         m->container_offsets[m->n_containers ++] = r;
 431
 432         return 0;
 433 }
 434
 435 int sd_netlink_message_open_container_union(sd_netlink_message *m, unsigned short type, const char *key) {
 436         const NLTypeSystemUnion *type_system_union;
 437         int r;
 438
 439         assert_return(m, -EINVAL);
 440         assert_return(!m->sealed, -EPERM);
 441
 442         r = type_system_get_type_system_union(m->container_type_system[m->n_containers], &type_system_union, type);
 443         if (r < 0)
 444                 return r;
 445
 446         r = type_system_union_get_type_system(type_system_union,
 447                                               &m->container_type_system[m->n_containers + 1],
 448                                               key);
 449         if (r < 0)
 450                 return r;
 451
 452         r = sd_netlink_message_append_string(m, type_system_union->match, key);
 453         if (r < 0)
 454                 return r;
 455
 456         /* do we evere need non-null size */
 457         r = add_rtattr(m, type, NULL, 0);
 458         if (r < 0)
 459                 return r;
 460
 461         m->container_offsets[m->n_containers ++] = r;
 462
 463         return 0;
 464 }
 465
 466
 467 int sd_netlink_message_close_container(sd_netlink_message *m) {
 468         assert_return(m, -EINVAL);
 469         assert_return(!m->sealed, -EPERM);
 470         assert_return(m->n_containers > 0, -EINVAL);
 471
 472         m->container_type_system[m->n_containers] = NULL;
 473         m->n_containers --;
 474
 475         return 0;
 476 }
 477
 478 int rtnl_message_read_internal(sd_netlink_message *m, unsigned short type, void **data) {
 479         struct rtattr *rta;
 480
 481         assert_return(m, -EINVAL);
 482         assert_return(m->sealed, -EPERM);
 483         assert_return(data, -EINVAL);
 484         assert(m->n_containers <= RTNL_CONTAINER_DEPTH);
 485         assert(m->rta_offset_tb[m->n_containers]);
 486         assert(type < m->rta_tb_size[m->n_containers]);
 487
 488         if(!m->rta_offset_tb[m->n_containers][type])
 489                 return -ENODATA;
 490
 491         rta = (struct rtattr*)((uint8_t *) m->hdr + m->rta_offset_tb[m->n_containers][type]);
 492
 493         *data = RTA_DATA(rta);
 494
 495         return RTA_PAYLOAD(rta);
 496 }
 497
 498 int sd_netlink_message_read_string(sd_netlink_message *m, unsigned short type, const char **data) {
 499         int r;
 500         void *attr_data;
 501
 502         assert_return(m, -EINVAL);
 503
 504         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_STRING);
 505         if (r < 0)
 506                 return r;
 507
 508         r = rtnl_message_read_internal(m, type, &attr_data);
 509         if (r < 0)
 510                 return r;
 511         else if (strnlen(attr_data, r) >= (size_t) r)
 512                 return -EIO;
 513
 514         if (data)
 515                 *data = (const char *) attr_data;
 516
 517         return 0;
 518 }
 519
 520 int sd_netlink_message_read_u8(sd_netlink_message *m, unsigned short type, uint8_t *data) {
 521         int r;
 522         void *attr_data;
 523
 524         assert_return(m, -EINVAL);
 525
 526         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U8);
 527         if (r < 0)
 528                 return r;
 529
 530         r = rtnl_message_read_internal(m, type, &attr_data);
 531         if (r < 0)
 532                 return r;
 533         else if ((size_t) r < sizeof(uint8_t))
 534                 return -EIO;
 535
 536         if (data)
 537                 *data = *(uint8_t *) attr_data;
 538
 539         return 0;
 540 }
 541
 542 int sd_netlink_message_read_u16(sd_netlink_message *m, unsigned short type, uint16_t *data) {
 543         int r;
 544         void *attr_data;
 545
 546         assert_return(m, -EINVAL);
 547
 548         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U16);
 549         if (r < 0)
 550                 return r;
 551
 552         r = rtnl_message_read_internal(m, type, &attr_data);
 553         if (r < 0)
 554                 return r;
 555         else if ((size_t) r < sizeof(uint16_t))
 556                 return -EIO;
 557
 558         if (data)
 559                 *data = *(uint16_t *) attr_data;
 560
 561         return 0;
 562 }
 563
 564 int sd_netlink_message_read_u32(sd_netlink_message *m, unsigned short type, uint32_t *data) {
 565         int r;
 566         void *attr_data;
 567
 568         assert_return(m, -EINVAL);
 569
 570         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_U32);
 571         if (r < 0)
 572                 return r;
 573
 574         r = rtnl_message_read_internal(m, type, &attr_data);
 575         if (r < 0)
 576                 return r;
 577         else if ((size_t)r < sizeof(uint32_t))
 578                 return -EIO;
 579
 580         if (data)
 581                 *data = *(uint32_t *) attr_data;
 582
 583         return 0;
 584 }
 585
 586 int sd_netlink_message_read_ether_addr(sd_netlink_message *m, unsigned short type, struct ether_addr *data) {
 587         int r;
 588         void *attr_data;
 589
 590         assert_return(m, -EINVAL);
 591
 592         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_ETHER_ADDR);
 593         if (r < 0)
 594                 return r;
 595
 596         r = rtnl_message_read_internal(m, type, &attr_data);
 597         if (r < 0)
 598                 return r;
 599         else if ((size_t)r < sizeof(struct ether_addr))
 600                 return -EIO;
 601
 602         if (data)
 603                 memcpy(data, attr_data, sizeof(struct ether_addr));
 604
 605         return 0;
 606 }
 607
 608 int sd_netlink_message_read_cache_info(sd_netlink_message *m, unsigned short type, struct ifa_cacheinfo *info) {
 609         int r;
 610         void *attr_data;
 611
 612         assert_return(m, -EINVAL);
 613
 614         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_CACHE_INFO);
 615         if (r < 0)
 616                 return r;
 617
 618         r = rtnl_message_read_internal(m, type, &attr_data);
 619         if (r < 0)
 620                 return r;
 621         else if ((size_t)r < sizeof(struct ifa_cacheinfo))
 622                 return -EIO;
 623
 624         if (info)
 625                 memcpy(info, attr_data, sizeof(struct ifa_cacheinfo));
 626
 627         return 0;
 628 }
 629
 630 int sd_netlink_message_read_in_addr(sd_netlink_message *m, unsigned short type, struct in_addr *data) {
 631         int r;
 632         void *attr_data;
 633
 634         assert_return(m, -EINVAL);
 635
 636         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR);
 637         if (r < 0)
 638                 return r;
 639
 640         r = rtnl_message_read_internal(m, type, &attr_data);
 641         if (r < 0)
 642                 return r;
 643         else if ((size_t)r < sizeof(struct in_addr))
 644                 return -EIO;
 645
 646         if (data)
 647                 memcpy(data, attr_data, sizeof(struct in_addr));
 648
 649         return 0;
 650 }
 651
 652 int sd_netlink_message_read_in6_addr(sd_netlink_message *m, unsigned short type, struct in6_addr *data) {
 653         int r;
 654         void *attr_data;
 655
 656         assert_return(m, -EINVAL);
 657
 658         r = message_attribute_has_type(m, NULL, type, NETLINK_TYPE_IN_ADDR);
 659         if (r < 0)
 660                 return r;
 661
 662         r = rtnl_message_read_internal(m, type, &attr_data);
 663         if (r < 0)
 664                 return r;
 665         else if ((size_t)r < sizeof(struct in6_addr))
 666                 return -EIO;
 667
 668         if (data)
 669                 memcpy(data, attr_data, sizeof(struct in6_addr));
 670
 671         return 0;
 672 }
 673
 674 int sd_netlink_message_enter_container(sd_netlink_message *m, unsigned short type_id) {
 675         const NLType *nl_type;
 676         const NLTypeSystem *type_system;
 677         void *container;
 678         uint16_t type;
 679         size_t size;
 680         int r;
 681
 682         assert_return(m, -EINVAL);
 683         assert_return(m->n_containers < RTNL_CONTAINER_DEPTH, -EINVAL);
 684
 685         r = type_system_get_type(m->container_type_system[m->n_containers],
 686                                  &nl_type,
 687                                  type_id);
 688         if (r < 0)
 689                 return r;
 690
 691         type = type_get_type(nl_type);
 692
 693         if (type == NETLINK_TYPE_NESTED) {
 694                 r = type_system_get_type_system(m->container_type_system[m->n_containers],
 695                                                 &type_system,
 696                                                 type_id);
 697                 if (r < 0)
 698                         return r;
 699         } else if (type == NETLINK_TYPE_UNION) {
 700                 const NLTypeSystemUnion *type_system_union;
 701
 702                 r = type_system_get_type_system_union(m->container_type_system[m->n_containers],
 703                                                       &type_system_union,
 704                                                       type_id);
 705                 if (r < 0)
 706                         return r;
 707
 708                 switch (type_system_union->match_type) {
 709                 case NL_MATCH_SIBLING:
 710                 {
 711                         const char *key;
 712
 713                         r = sd_netlink_message_read_string(m, type_system_union->match, &key);
 714                         if (r < 0)
 715                                 return r;
 716
 717                         r = type_system_union_get_type_system(type_system_union,
 718                                                               &type_system,
 719                                                               key);
 720                         if (r < 0)
 721                                 return r;
 722
 723                         break;
 724                 }
 725                 case NL_MATCH_PROTOCOL:
 726                 {
 727                         int family;
 728
 729                         r = sd_rtnl_message_get_family(m, &family);
 730                         if (r < 0)
 731                                 return r;
 732
 733                         r = type_system_union_protocol_get_type_system(type_system_union,
 734                                                                        &type_system,
 735                                                                        family);
 736                         if (r < 0)
 737                                 return r;
 738
 739                         break;
 740                 }
 741                 default:
 742                         assert_not_reached("sd-netlink: invalid type system union type");
 743                 }
 744         } else
 745                 return -EINVAL;
 746
 747         r = rtnl_message_read_internal(m, type_id, &container);
 748         if (r < 0)
 749                 return r;
 750         else
 751                 size = (size_t)r;
 752
 753         m->n_containers ++;
 754
 755         r = rtnl_message_parse(m,
 756                                &m->rta_offset_tb[m->n_containers],
 757                                &m->rta_tb_size[m->n_containers],
 758                                type_system_get_count(type_system),
 759                                container,
 760                                size);
 761         if (r < 0) {
 762                 m->n_containers --;
 763                 return r;
 764         }
 765
 766         m->container_type_system[m->n_containers] = type_system;
 767
 768         return 0;
 769 }
 770
 771 int sd_netlink_message_exit_container(sd_netlink_message *m) {
 772         assert_return(m, -EINVAL);
 773         assert_return(m->sealed, -EINVAL);
 774         assert_return(m->n_containers > 0, -EINVAL);
 775
 776         free(m->rta_offset_tb[m->n_containers]);
 777         m->rta_offset_tb[m->n_containers] = NULL;
 778         m->container_type_system[m->n_containers] = NULL;
 779
 780         m->n_containers --;
 781
 782         return 0;
 783 }
 784
 785 uint32_t rtnl_message_get_serial(sd_netlink_message *m) {
 786         assert(m);
 787         assert(m->hdr);
 788
 789         return m->hdr->nlmsg_seq;
 790 }
 791
 792 int sd_netlink_message_is_error(sd_netlink_message *m) {
 793         assert_return(m, 0);
 794         assert_return(m->hdr, 0);
 795
 796         return m->hdr->nlmsg_type == NLMSG_ERROR;
 797 }
 798
 799 int sd_netlink_message_get_errno(sd_netlink_message *m) {
 800         struct nlmsgerr *err;
 801
 802         assert_return(m, -EINVAL);
 803         assert_return(m->hdr, -EINVAL);
 804
 805         if (!sd_netlink_message_is_error(m))
 806                 return 0;
 807
 808         err = NLMSG_DATA(m->hdr);
 809
 810         return err->error;
 811 }
 812
 813 int rtnl_message_parse(sd_netlink_message *m,
 814                        size_t **rta_offset_tb,
 815                        unsigned short *rta_tb_size,
 816                        int count,
 817                        struct rtattr *rta,
 818                        unsigned int rt_len) {
 819         unsigned short type;
 820         size_t *tb;
 821
 822         tb = new0(size_t, count);
 823         if(!tb)
 824                 return -ENOMEM;
 825
 826         *rta_tb_size = count;
 827
 828         for (; RTA_OK(rta, rt_len); rta = RTA_NEXT(rta, rt_len)) {
 829                 type = RTA_TYPE(rta);
 830
 831                 /* if the kernel is newer than the headers we used
 832                    when building, we ignore out-of-range attributes
 833                  */
 834                 if (type >= count)
 835                         continue;
 836
 837                 if (tb[type])
 838                         log_debug("rtnl: message parse - overwriting repeated attribute");
 839
 840                 tb[type] = (uint8_t *) rta - (uint8_t *) m->hdr;
 841         }
 842
 843         *rta_offset_tb = tb;
 844
 845         return 0;
 846 }
 847
 848 int sd_netlink_message_rewind(sd_netlink_message *m) {
 849         const NLType *nl_type;
 850         uint16_t type;
 851         size_t size;
 852         unsigned i;
 853         int r;
 854
 855         assert_return(m, -EINVAL);
 856
 857         /* don't allow appending to message once parsed */
 858         if (!m->sealed)
 859                 rtnl_message_seal(m);
 860
 861         for (i = 1; i <= m->n_containers; i++) {
 862                 free(m->rta_offset_tb[i]);
 863                 m->rta_offset_tb[i] = NULL;
 864                 m->rta_tb_size[i] = 0;
 865                 m->container_type_system[i] = NULL;
 866         }
 867
 868         m->n_containers = 0;
 869
 870         if (m->rta_offset_tb[0]) {
 871                 /* top-level attributes have already been parsed */
 872                 return 0;
 873         }
 874
 875         assert(m->hdr);
 876
 877         r = type_system_get_type(&type_system_root, &nl_type, m->hdr->nlmsg_type);
 878         if (r < 0)
 879                 return r;
 880
 881         type = type_get_type(nl_type);
 882         size = type_get_size(nl_type);
 883
 884         if (type == NETLINK_TYPE_NESTED) {
 885                 const NLTypeSystem *type_system;
 886
 887                 type_get_type_system(nl_type, &type_system);
 888
 889                 m->container_type_system[0] = type_system;
 890
 891                 r = rtnl_message_parse(m,
 892                                        &m->rta_offset_tb[m->n_containers],
 893                                        &m->rta_tb_size[m->n_containers],
 894                                        type_system_get_count(type_system),
 895                                        (struct rtattr*)((uint8_t*)NLMSG_DATA(m->hdr) + NLMSG_ALIGN(size)),
 896                                        NLMSG_PAYLOAD(m->hdr, size));
 897                 if (r < 0)
 898                         return r;
 899         }
 900
 901         return 0;
 902 }
 903
 904 void rtnl_message_seal(sd_netlink_message *m) {
 905         assert(m);
 906         assert(!m->sealed);
 907
 908         m->sealed = true;
 909 }
 910
 911 sd_netlink_message *sd_netlink_message_next(sd_netlink_message *m) {
 912         assert_return(m, NULL);
 913
 914         return m->next;
 915 }