src/netlink.c

   1 /**
   2  * Copyright (C) 2017 Hans Dedecker <dedeckeh@gmail.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License v2 as published by
   6  * the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  */
  14
  15 #include <errno.h>
  16 #include <string.h>
  17 #include <syslog.h>
  18
  19 #include <linux/netlink.h>
  20 #include <linux/if_addr.h>
  21 #include <linux/neighbour.h>
  22 #include <linux/rtnetlink.h>
  23
  24 #include <netlink/msg.h>
  25 #include <netlink/socket.h>
  26 #include <netlink/attr.h>
  27
  28 #include <arpa/inet.h>
  29 #include <libubox/list.h>
  30
  31 #include "odhcpd.h"
  32
  33 struct event_socket {
  34         struct odhcpd_event ev;
  35         struct nl_sock *sock;
  36         int sock_bufsize;
  37 };
  38
  39 static void handle_rtnl_event(struct odhcpd_event *ev);
  40 static int cb_rtnl_valid(struct nl_msg *msg, void *arg);
  41 static void catch_rtnl_err(struct odhcpd_event *e, int error);
  42 static struct nl_sock *create_socket(int protocol);
  43
  44 static struct nl_sock *rtnl_socket = NULL;
  45 struct list_head netevent_handler_list = LIST_HEAD_INIT(netevent_handler_list);
  46 static struct event_socket rtnl_event = {
  47         .ev = {
  48                 .uloop = {.fd = - 1, },
  49                 .handle_dgram = NULL,
  50                 .handle_error = catch_rtnl_err,
  51                 .recv_msgs = handle_rtnl_event,
  52         },
  53         .sock = NULL,
  54         .sock_bufsize = 133120,
  55 };
  56
  57 int netlink_init(void)
  58 {
  59         rtnl_socket = create_socket(NETLINK_ROUTE);
  60         if (!rtnl_socket) {
  61                 syslog(LOG_ERR, "Unable to open nl socket: %m");
  62                 goto err;
  63         }
  64
  65         rtnl_event.sock = create_socket(NETLINK_ROUTE);
  66         if (!rtnl_event.sock) {
  67                 syslog(LOG_ERR, "Unable to open nl event socket: %m");
  68                 goto err;
  69         }
  70
  71         rtnl_event.ev.uloop.fd = nl_socket_get_fd(rtnl_event.sock);
  72
  73         if (nl_socket_set_buffer_size(rtnl_event.sock, rtnl_event.sock_bufsize, 0))
  74                 goto err;
  75
  76         nl_socket_disable_seq_check(rtnl_event.sock);
  77
  78         nl_socket_modify_cb(rtnl_event.sock, NL_CB_VALID, NL_CB_CUSTOM,
  79                         cb_rtnl_valid, NULL);
  80
  81         /* Receive IPv4 address, IPv6 address, IPv6 routes and neighbor events */
  82         if (nl_socket_add_memberships(rtnl_event.sock, RTNLGRP_IPV4_IFADDR,
  83                                 RTNLGRP_IPV6_IFADDR, RTNLGRP_IPV6_ROUTE,
  84                                 RTNLGRP_NEIGH, RTNLGRP_LINK, 0))
  85                 goto err;
  86
  87         odhcpd_register(&rtnl_event.ev);
  88
  89         return 0;
  90
  91 err:
  92         if (rtnl_socket) {
  93                 nl_socket_free(rtnl_socket);
  94                 rtnl_socket = NULL;
  95         }
  96
  97         if (rtnl_event.sock) {
  98                 nl_socket_free(rtnl_event.sock);
  99                 rtnl_event.sock = NULL;
 100                 rtnl_event.ev.uloop.fd = -1;
 101         }
 102
 103         return -1;
 104 }
 105
 106
 107 int netlink_add_netevent_handler(struct netevent_handler *handler)
 108 {
 109         if (!handler->cb)
 110                 return -1;
 111
 112         list_add(&handler->head, &netevent_handler_list);
 113
 114         return 0;
 115 }
 116
 117 static void call_netevent_handler_list(unsigned long event, struct netevent_handler_info *info)
 118 {
 119         struct netevent_handler *handler;
 120
 121         list_for_each_entry(handler, &netevent_handler_list, head)
 122                 handler->cb(event, info);
 123 }
 124
 125 static void handle_rtnl_event(struct odhcpd_event *e)
 126 {
 127         struct event_socket *ev_sock = container_of(e, struct event_socket, ev);
 128
 129         nl_recvmsgs_default(ev_sock->sock);
 130 }
 131
 132 static void refresh_iface_addr4(int ifindex)
 133 {
 134         struct odhcpd_ipaddr *addr = NULL;
 135         struct interface *iface;
 136         ssize_t len = netlink_get_interface_addrs(ifindex, false, &addr);
 137         bool change = false;
 138
 139         if (len < 0)
 140                 return;
 141
 142         avl_for_each_element(&interfaces, iface, avl) {
 143                 if (iface->ifindex != ifindex)
 144                         continue;
 145
 146                 change = len != (ssize_t)iface->addr4_len;
 147                 for (ssize_t i = 0; !change && i < len; ++i) {
 148                         if (addr[i].addr.in.s_addr != iface->addr4[i].addr.in.s_addr)
 149                                 change = true;
 150                 }
 151                 break;
 152         }
 153
 154         if (!change) {
 155                 free(addr);
 156                 return;
 157         }
 158
 159         avl_for_element_range(iface, avl_last_element(&interfaces, iface, avl), iface, avl) {
 160                 struct netevent_handler_info event_info;
 161
 162                 if (iface->ifindex != ifindex)
 163                         continue;
 164
 165                 memset(&event_info, 0, sizeof(event_info));
 166                 event_info.iface = iface;
 167                 event_info.addrs_old.addrs = iface->addr4;
 168                 event_info.addrs_old.len = iface->addr4_len;
 169
 170                 iface->addr4 = addr;
 171                 iface->addr4_len = len;
 172
 173                 call_netevent_handler_list(NETEV_ADDRLIST_CHANGE, &event_info);
 174
 175                 free(event_info.addrs_old.addrs);
 176
 177                 if (len) {
 178                         addr = malloc(len * sizeof(*addr));
 179                         if (!addr)
 180                                 return;
 181
 182                         memcpy(addr, iface->addr4, len * sizeof(*addr));
 183                 }
 184         }
 185
 186         free(addr);
 187 }
 188
 189 static void refresh_iface_addr6(int ifindex)
 190 {
 191         struct odhcpd_ipaddr *addr = NULL;
 192         struct interface *iface;
 193         ssize_t len = netlink_get_interface_addrs(ifindex, true, &addr);
 194         time_t now = odhcpd_time();
 195         bool change = false;
 196
 197         if (len < 0)
 198                 return;
 199
 200         avl_for_each_element(&interfaces, iface, avl) {
 201                 if (iface->ifindex != ifindex)
 202                         continue;
 203
 204                 change = len != (ssize_t)iface->addr6_len;
 205                 for (ssize_t i = 0; !change && i < len; ++i) {
 206                         if (!IN6_ARE_ADDR_EQUAL(&addr[i].addr.in6, &iface->addr6[i].addr.in6) ||
 207                             (addr[i].preferred > (uint32_t)now) != (iface->addr6[i].preferred > (uint32_t)now) ||
 208                             addr[i].valid < iface->addr6[i].valid || addr[i].preferred < iface->addr6[i].preferred)
 209                                 change = true;
 210                 }
 211                 break;
 212         }
 213
 214         if (!change) {
 215                 free(iface->addr6);
 216                 iface->addr6 = addr;
 217                 iface->addr6_len = len;
 218                 return;
 219         }
 220
 221         avl_for_element_range(iface, avl_last_element(&interfaces, iface, avl), iface, avl) {
 222                 struct netevent_handler_info event_info;
 223
 224                 if (iface->ifindex != ifindex)
 225                         continue;
 226
 227                 memset(&event_info, 0, sizeof(event_info));
 228                 event_info.iface = iface;
 229                 event_info.addrs_old.addrs = iface->addr6;
 230                 event_info.addrs_old.len = iface->addr6_len;
 231
 232                 iface->addr6 = addr;
 233                 iface->addr6_len = len;
 234
 235                 call_netevent_handler_list(NETEV_ADDR6LIST_CHANGE, &event_info);
 236
 237                 free(event_info.addrs_old.addrs);
 238
 239                 if (len) {
 240                         addr = malloc(len * sizeof(*addr));
 241                         if (!addr)
 242                             return;
 243
 244                         memcpy(addr, iface->addr6, len * sizeof(*addr));
 245                 }
 246         }
 247
 248         free(addr);
 249 }
 250
 251 static int handle_rtm_link(struct nlmsghdr *hdr)
 252 {
 253         struct ifinfomsg *ifi = nlmsg_data(hdr);
 254         struct nlattr *nla[__IFLA_MAX];
 255         struct interface *iface;
 256         struct netevent_handler_info event_info;
 257         const char *ifname;
 258
 259         memset(&event_info, 0, sizeof(event_info));
 260
 261         if (!nlmsg_valid_hdr(hdr, sizeof(*ifi)) || ifi->ifi_family != AF_UNSPEC)
 262                 return NL_SKIP;
 263
 264         nlmsg_parse(hdr, sizeof(*ifi), nla, __IFLA_MAX - 1, NULL);
 265         if (!nla[IFLA_IFNAME])
 266                 return NL_SKIP;
 267
 268         ifname = nla_get_string(nla[IFLA_IFNAME]);
 269
 270         avl_for_each_element(&interfaces, iface, avl) {
 271                 if (strcmp(iface->ifname, ifname) || iface->ifindex == ifi->ifi_index)
 272                         continue;
 273
 274                 iface->ifindex = ifi->ifi_index;
 275                 event_info.iface = iface;
 276                 call_netevent_handler_list(NETEV_IFINDEX_CHANGE, &event_info);
 277         }
 278
 279         return NL_OK;
 280 }
 281
 282 static int handle_rtm_route(struct nlmsghdr *hdr, bool add)
 283 {
 284         struct rtmsg *rtm = nlmsg_data(hdr);
 285         struct nlattr *nla[__RTA_MAX];
 286         struct interface *iface;
 287         struct netevent_handler_info event_info;
 288         int ifindex = 0;
 289
 290         if (!nlmsg_valid_hdr(hdr, sizeof(*rtm)) || rtm->rtm_family != AF_INET6)
 291                 return NL_SKIP;
 292
 293         nlmsg_parse(hdr, sizeof(*rtm), nla, __RTA_MAX - 1, NULL);
 294
 295         memset(&event_info, 0, sizeof(event_info));
 296         event_info.rt.dst_len = rtm->rtm_dst_len;
 297
 298         if (nla[RTA_DST])
 299                 nla_memcpy(&event_info.rt.dst, nla[RTA_DST],
 300                                 sizeof(event_info.rt.dst));
 301
 302         if (nla[RTA_OIF])
 303                 ifindex = nla_get_u32(nla[RTA_OIF]);
 304
 305         if (nla[RTA_GATEWAY])
 306                 nla_memcpy(&event_info.rt.gateway, nla[RTA_GATEWAY],
 307                                 sizeof(event_info.rt.gateway));
 308
 309         avl_for_each_element(&interfaces, iface, avl) {
 310                 if (ifindex && iface->ifindex != ifindex)
 311                         continue;
 312
 313                 event_info.iface = ifindex ? iface : NULL;
 314                 call_netevent_handler_list(add ? NETEV_ROUTE6_ADD : NETEV_ROUTE6_DEL,
 315                                                 &event_info);
 316         }
 317
 318         return NL_OK;
 319 }
 320
 321 static int handle_rtm_addr(struct nlmsghdr *hdr, bool add)
 322 {
 323         struct ifaddrmsg *ifa = nlmsg_data(hdr);
 324         struct nlattr *nla[__IFA_MAX];
 325         struct interface *iface;
 326         struct netevent_handler_info event_info;
 327         char buf[INET6_ADDRSTRLEN];
 328
 329         if (!nlmsg_valid_hdr(hdr, sizeof(*ifa)) ||
 330                         (ifa->ifa_family != AF_INET6 &&
 331                          ifa->ifa_family != AF_INET))
 332                 return NL_SKIP;
 333
 334         memset(&event_info, 0, sizeof(event_info));
 335
 336         nlmsg_parse(hdr, sizeof(*ifa), nla, __IFA_MAX - 1, NULL);
 337
 338         if (ifa->ifa_family == AF_INET6) {
 339                 if (!nla[IFA_ADDRESS])
 340                         return NL_SKIP;
 341
 342                 nla_memcpy(&event_info.addr, nla[IFA_ADDRESS], sizeof(event_info.addr));
 343
 344                 if (IN6_IS_ADDR_LINKLOCAL(&event_info.addr) || IN6_IS_ADDR_MULTICAST(&event_info.addr))
 345                         return NL_SKIP;
 346
 347                 inet_ntop(AF_INET6, &event_info.addr, buf, sizeof(buf));
 348
 349                 avl_for_each_element(&interfaces, iface, avl) {
 350                         if (iface->ifindex != (int)ifa->ifa_index)
 351                                 continue;
 352
 353                         syslog(LOG_DEBUG, "Netlink %s %s on %s", add ? "newaddr" : "deladdr",
 354                                         buf, iface->name);
 355
 356                         event_info.iface = iface;
 357                         call_netevent_handler_list(add ? NETEV_ADDR6_ADD : NETEV_ADDR6_DEL,
 358                                                         &event_info);
 359                 }
 360
 361                 refresh_iface_addr6(ifa->ifa_index);
 362         } else {
 363                 if (!nla[IFA_LOCAL])
 364                         return NL_SKIP;
 365
 366                 nla_memcpy(&event_info.addr, nla[IFA_LOCAL], sizeof(event_info.addr));
 367
 368                 inet_ntop(AF_INET, &event_info.addr, buf, sizeof(buf));
 369
 370                 avl_for_each_element(&interfaces, iface, avl) {
 371                         if (iface->ifindex != (int)ifa->ifa_index)
 372                                 continue;
 373
 374                         syslog(LOG_DEBUG, "Netlink %s %s on %s", add ? "newaddr" : "deladdr",
 375                                         buf, iface->name);
 376
 377                         event_info.iface = iface;
 378                         call_netevent_handler_list(add ? NETEV_ADDR_ADD : NETEV_ADDR_DEL,
 379                                                         &event_info);
 380                 }
 381
 382                 refresh_iface_addr4(ifa->ifa_index);
 383         }
 384
 385         return NL_OK;
 386 }
 387
 388 static int handle_rtm_neigh(struct nlmsghdr *hdr, bool add)
 389 {
 390         struct ndmsg *ndm = nlmsg_data(hdr);
 391         struct nlattr *nla[__NDA_MAX];
 392         struct interface *iface;
 393         struct netevent_handler_info event_info;
 394         char buf[INET6_ADDRSTRLEN];
 395
 396         if (!nlmsg_valid_hdr(hdr, sizeof(*ndm)) ||
 397                         ndm->ndm_family != AF_INET6)
 398                 return NL_SKIP;
 399
 400         nlmsg_parse(hdr, sizeof(*ndm), nla, __NDA_MAX - 1, NULL);
 401         if (!nla[NDA_DST])
 402                 return NL_SKIP;
 403
 404         memset(&event_info, 0, sizeof(event_info));
 405
 406         nla_memcpy(&event_info.neigh.dst, nla[NDA_DST], sizeof(event_info.neigh.dst));
 407
 408         if (IN6_IS_ADDR_LINKLOCAL(&event_info.neigh.dst) ||
 409                         IN6_IS_ADDR_MULTICAST(&event_info.neigh.dst))
 410                 return NL_SKIP;
 411
 412         inet_ntop(AF_INET6, &event_info.neigh.dst, buf, sizeof(buf));
 413
 414         avl_for_each_element(&interfaces, iface, avl) {
 415                 if (iface->ifindex != ndm->ndm_ifindex)
 416                         continue;
 417
 418                 syslog(LOG_DEBUG, "Netlink %s %s on %s", true ? "newneigh" : "delneigh",
 419                                 buf, iface->name);
 420
 421                 event_info.iface = iface;
 422                 event_info.neigh.state = ndm->ndm_state;
 423                 event_info.neigh.flags = ndm->ndm_flags;
 424
 425                 call_netevent_handler_list(add ? NETEV_NEIGH6_ADD : NETEV_NEIGH6_DEL,
 426                                                 &event_info);
 427         }
 428
 429         return NL_OK;
 430 }
 431
 432 /* Handler for neighbor cache entries from the kernel. This is our source
 433  * to learn and unlearn hosts on interfaces. */
 434 static int cb_rtnl_valid(struct nl_msg *msg, _unused void *arg)
 435 {
 436         struct nlmsghdr *hdr = nlmsg_hdr(msg);
 437         int ret = NL_SKIP;
 438         bool add = false;
 439
 440         switch (hdr->nlmsg_type) {
 441         case RTM_NEWLINK:
 442                 ret = handle_rtm_link(hdr);
 443                 break;
 444
 445         case RTM_NEWROUTE:
 446                 add = true;
 447                 /* fall through */
 448         case RTM_DELROUTE:
 449                 ret = handle_rtm_route(hdr, add);
 450                 break;
 451
 452         case RTM_NEWADDR:
 453                 add = true;
 454                 /* fall through */
 455         case RTM_DELADDR:
 456                 ret = handle_rtm_addr(hdr, add);
 457                 break;
 458
 459         case RTM_NEWNEIGH:
 460                 add = true;
 461                 /* fall through */
 462         case RTM_DELNEIGH:
 463                 ret = handle_rtm_neigh(hdr, add);
 464                 break;
 465
 466         default:
 467                 break;
 468         }
 469
 470         return ret;
 471 }
 472
 473 static void catch_rtnl_err(struct odhcpd_event *e, int error)
 474 {
 475         struct event_socket *ev_sock = container_of(e, struct event_socket, ev);
 476
 477         if (error != ENOBUFS)
 478                 goto err;
 479
 480         /* Double netlink event buffer size */
 481         ev_sock->sock_bufsize *= 2;
 482
 483         if (nl_socket_set_buffer_size(ev_sock->sock, ev_sock->sock_bufsize, 0))
 484                 goto err;
 485
 486         netlink_dump_addr_table(true);
 487         return;
 488
 489 err:
 490         odhcpd_deregister(e);
 491 }
 492
 493 static struct nl_sock *create_socket(int protocol)
 494 {
 495         struct nl_sock *nl_sock;
 496
 497         nl_sock = nl_socket_alloc();
 498         if (!nl_sock)
 499                 goto err;
 500
 501         if (nl_connect(nl_sock, protocol) < 0)
 502                 goto err;
 503
 504         return nl_sock;
 505
 506 err:
 507         if (nl_sock)
 508                 nl_socket_free(nl_sock);
 509
 510         return NULL;
 511 }
 512
 513
 514 struct addr_info {
 515         int ifindex;
 516         int af;
 517         struct odhcpd_ipaddr **addrs;
 518         int pending;
 519         ssize_t ret;
 520 };
 521
 522
 523 static int cb_valid_handler(struct nl_msg *msg, void *arg)
 524 {
 525         struct addr_info *ctxt = (struct addr_info *)arg;
 526         struct odhcpd_ipaddr *addrs = *(ctxt->addrs);
 527         struct nlmsghdr *hdr = nlmsg_hdr(msg);
 528         struct ifaddrmsg *ifa;
 529         struct nlattr *nla[__IFA_MAX], *nla_addr = NULL;
 530
 531         if (hdr->nlmsg_type != RTM_NEWADDR)
 532                 return NL_SKIP;
 533
 534         ifa = NLMSG_DATA(hdr);
 535         if (ifa->ifa_scope != RT_SCOPE_UNIVERSE ||
 536                         (ctxt->af != ifa->ifa_family) ||
 537                         (ctxt->ifindex && ifa->ifa_index != (unsigned)ctxt->ifindex))
 538                 return NL_SKIP;
 539
 540         nlmsg_parse(hdr, sizeof(*ifa), nla, __IFA_MAX - 1, NULL);
 541
 542         switch (ifa->ifa_family) {
 543         case AF_INET6:
 544                 if (nla[IFA_ADDRESS])
 545                         nla_addr = nla[IFA_ADDRESS];
 546                 break;
 547
 548         case AF_INET:
 549                 if (nla[IFA_LOCAL])
 550                         nla_addr = nla[IFA_LOCAL];
 551                 break;
 552
 553         default:
 554                 break;
 555         }
 556         if (!nla_addr)
 557                 return NL_SKIP;
 558
 559         addrs = realloc(addrs, sizeof(*addrs)*(ctxt->ret + 1));
 560         if (!addrs)
 561                 return NL_SKIP;
 562
 563         memset(&addrs[ctxt->ret], 0, sizeof(addrs[ctxt->ret]));
 564         addrs[ctxt->ret].prefix = ifa->ifa_prefixlen;
 565
 566         nla_memcpy(&addrs[ctxt->ret].addr, nla_addr,
 567                         sizeof(addrs[ctxt->ret].addr));
 568
 569         if (nla[IFA_BROADCAST])
 570                 nla_memcpy(&addrs[ctxt->ret].broadcast, nla[IFA_BROADCAST],
 571                                 sizeof(addrs[ctxt->ret].broadcast));
 572
 573         if (nla[IFA_CACHEINFO]) {
 574                 struct ifa_cacheinfo *ifc = nla_data(nla[IFA_CACHEINFO]);
 575
 576                 addrs[ctxt->ret].preferred = ifc->ifa_prefered;
 577                 addrs[ctxt->ret].valid = ifc->ifa_valid;
 578         }
 579
 580         if (ifa->ifa_flags & IFA_F_DEPRECATED)
 581                 addrs[ctxt->ret].preferred = 0;
 582
 583         ctxt->ret++;
 584         *(ctxt->addrs) = addrs;
 585
 586         return NL_OK;
 587 }
 588
 589
 590 static int cb_finish_handler(_unused struct nl_msg *msg, void *arg)
 591 {
 592         struct addr_info *ctxt = (struct addr_info *)arg;
 593
 594         ctxt->pending = 0;
 595
 596         return NL_STOP;
 597 }
 598
 599
 600 static int cb_error_handler(_unused struct sockaddr_nl *nla, struct nlmsgerr *err,
 601                 void *arg)
 602 {
 603         struct addr_info *ctxt = (struct addr_info *)arg;
 604
 605         ctxt->pending = 0;
 606         ctxt->ret = err->error;
 607
 608         return NL_STOP;
 609 }
 610
 611
 612 static int prefix_cmp(const void *va, const void *vb)
 613 {
 614         const struct odhcpd_ipaddr *a = va, *b = vb;
 615         int ret = 0;
 616
 617         if (a->prefix == b->prefix) {
 618                 ret = (ntohl(a->addr.in.s_addr) < ntohl(b->addr.in.s_addr)) ? 1 :
 619                         (ntohl(a->addr.in.s_addr) > ntohl(b->addr.in.s_addr)) ? -1 : 0;
 620         } else
 621                 ret = a->prefix < b->prefix ? 1 : -1;
 622
 623         return ret;
 624 }
 625
 626
 627 /* compare IPv6 prefixes */
 628 static int prefix6_cmp(const void *va, const void *vb)
 629 {
 630         const struct odhcpd_ipaddr *a = va, *b = vb;
 631         uint32_t a_pref = IN6_IS_ADDR_ULA(&a->addr.in6) ? 1 : a->preferred;
 632         uint32_t b_pref = IN6_IS_ADDR_ULA(&b->addr.in6) ? 1 : b->preferred;
 633         return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
 634 }
 635
 636
 637 /* Detect an IPV6-address currently assigned to the given interface */
 638 ssize_t netlink_get_interface_addrs(int ifindex, bool v6, struct odhcpd_ipaddr **addrs)
 639 {
 640         struct nl_msg *msg;
 641         struct ifaddrmsg ifa = {
 642                 .ifa_family = v6? AF_INET6: AF_INET,
 643                 .ifa_prefixlen = 0,
 644                 .ifa_flags = 0,
 645                 .ifa_scope = 0,
 646                 .ifa_index = ifindex, };
 647         struct nl_cb *cb = nl_cb_alloc(NL_CB_DEFAULT);
 648         struct addr_info ctxt = {
 649                 .ifindex = ifindex,
 650                 .af = v6? AF_INET6: AF_INET,
 651                 .addrs = addrs,
 652                 .ret = 0,
 653                 .pending = 1,
 654         };
 655
 656         if (!cb) {
 657                 ctxt.ret = -1;
 658                 goto out;
 659         }
 660
 661         msg = nlmsg_alloc_simple(RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP);
 662
 663         if (!msg) {
 664                 ctxt.ret = - 1;
 665                 goto out;
 666         }
 667
 668         nlmsg_append(msg, &ifa, sizeof(ifa), 0);
 669
 670         nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, cb_valid_handler, &ctxt);
 671         nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, cb_finish_handler, &ctxt);
 672         nl_cb_err(cb, NL_CB_CUSTOM, cb_error_handler, &ctxt);
 673
 674         nl_send_auto_complete(rtnl_socket, msg);
 675         while (ctxt.pending > 0)
 676                 nl_recvmsgs(rtnl_socket, cb);
 677
 678         nlmsg_free(msg);
 679
 680         if (ctxt.ret <= 0)
 681                 goto out;
 682
 683         time_t now = odhcpd_time();
 684         struct odhcpd_ipaddr *addr = *addrs;
 685
 686         qsort(addr, ctxt.ret, sizeof(*addr), v6 ? prefix6_cmp : prefix_cmp);
 687
 688         for (ssize_t i = 0; i < ctxt.ret; ++i) {
 689                 if (addr[i].preferred < UINT32_MAX - now)
 690                         addr[i].preferred += now;
 691
 692                 if (addr[i].valid < UINT32_MAX - now)
 693                         addr[i].valid += now;
 694         }
 695
 696 out:
 697         nl_cb_put(cb);
 698
 699         return ctxt.ret;
 700 }
 701
 702
 703 int netlink_setup_route(const struct in6_addr *addr, const int prefixlen,
 704                 const int ifindex, const struct in6_addr *gw,
 705                 const uint32_t metric, const bool add)
 706 {
 707         struct nl_msg *msg;
 708         struct rtmsg rtm = {
 709                 .rtm_family = AF_INET6,
 710                 .rtm_dst_len = prefixlen,
 711                 .rtm_src_len = 0,
 712                 .rtm_table = RT_TABLE_MAIN,
 713                 .rtm_protocol = (add ? RTPROT_STATIC : RTPROT_UNSPEC),
 714                 .rtm_scope = (add ? (gw ? RT_SCOPE_UNIVERSE : RT_SCOPE_LINK) : RT_SCOPE_NOWHERE),
 715                 .rtm_type = (add ? RTN_UNICAST : RTN_UNSPEC),
 716         };
 717         int ret = 0;
 718
 719         msg = nlmsg_alloc_simple(add ? RTM_NEWROUTE : RTM_DELROUTE,
 720                                         add ? NLM_F_CREATE | NLM_F_REPLACE : 0);
 721         if (!msg)
 722                 return -1;
 723
 724         nlmsg_append(msg, &rtm, sizeof(rtm), 0);
 725
 726         nla_put(msg, RTA_DST, sizeof(*addr), addr);
 727         nla_put_u32(msg, RTA_OIF, ifindex);
 728         nla_put_u32(msg, RTA_PRIORITY, metric);
 729
 730         if (gw)
 731                 nla_put(msg, RTA_GATEWAY, sizeof(*gw), gw);
 732
 733         ret = nl_send_auto_complete(rtnl_socket, msg);
 734         nlmsg_free(msg);
 735
 736         if (ret < 0)
 737                 return ret;
 738
 739         return nl_wait_for_ack(rtnl_socket);
 740 }
 741
 742
 743 int netlink_setup_proxy_neigh(const struct in6_addr *addr,
 744                 const int ifindex, const bool add)
 745 {
 746         struct nl_msg *msg;
 747         struct ndmsg ndm = {
 748                 .ndm_family = AF_INET6,
 749                 .ndm_flags = NTF_PROXY,
 750                 .ndm_ifindex = ifindex,
 751         };
 752         int ret = 0, flags = NLM_F_REQUEST;
 753
 754         if (add)
 755                 flags |= NLM_F_REPLACE | NLM_F_CREATE;
 756
 757         msg = nlmsg_alloc_simple(add ? RTM_NEWNEIGH : RTM_DELNEIGH, flags);
 758         if (!msg)
 759                 return -1;
 760
 761         nlmsg_append(msg, &ndm, sizeof(ndm), 0);
 762
 763         nla_put(msg, NDA_DST, sizeof(*addr), addr);
 764
 765         ret = nl_send_auto_complete(rtnl_socket, msg);
 766         nlmsg_free(msg);
 767
 768         if (ret < 0)
 769                 return ret;
 770
 771         return nl_wait_for_ack(rtnl_socket);
 772 }
 773
 774
 775 int netlink_setup_addr(struct odhcpd_ipaddr *addr,
 776                 const int ifindex, const bool v6, const bool add)
 777 {
 778         struct nl_msg *msg;
 779         struct ifaddrmsg ifa = {
 780                 .ifa_family = v6 ? AF_INET6 : AF_INET,
 781                 .ifa_prefixlen = addr->prefix,
 782                 .ifa_flags = 0,
 783                 .ifa_scope = 0,
 784                 .ifa_index = ifindex, };
 785         int ret = 0, flags = NLM_F_REQUEST;
 786
 787         if (add)
 788                 flags |= NLM_F_REPLACE | NLM_F_CREATE;
 789
 790         msg = nlmsg_alloc_simple(add ? RTM_NEWADDR : RTM_DELADDR, 0);
 791         if (!msg)
 792                 return -1;
 793
 794         nlmsg_append(msg, &ifa, sizeof(ifa), flags);
 795         nla_put(msg, IFA_LOCAL, v6 ? 16 : 4, &addr->addr);
 796         if (v6) {
 797                 struct ifa_cacheinfo cinfo = {  .ifa_prefered = 0xffffffffU,
 798                                                 .ifa_valid = 0xffffffffU,
 799                                                 .cstamp = 0,
 800                                                 .tstamp = 0 };
 801                 time_t now = odhcpd_time();
 802
 803                 if (addr->preferred) {
 804                         int64_t preferred = addr->preferred - now;
 805                         if (preferred < 0)
 806                                 preferred = 0;
 807                         else if (preferred > UINT32_MAX)
 808                                 preferred = UINT32_MAX;
 809
 810                         cinfo.ifa_prefered = preferred;
 811                 }
 812
 813                 if (addr->valid) {
 814                         int64_t valid = addr->valid - now;
 815                         if (valid <= 0) {
 816                                 nlmsg_free(msg);
 817                                 return -1;
 818                         }
 819                         else if (valid > UINT32_MAX)
 820                                 valid = UINT32_MAX;
 821
 822                         cinfo.ifa_valid = valid;
 823                 }
 824
 825                 nla_put(msg, IFA_CACHEINFO, sizeof(cinfo), &cinfo);
 826
 827                 nla_put_u32(msg, IFA_FLAGS, IFA_F_NOPREFIXROUTE);
 828         } else {
 829                 if (addr->broadcast.s_addr)
 830                         nla_put_u32(msg, IFA_BROADCAST, addr->broadcast.s_addr);
 831         }
 832
 833         ret = nl_send_auto_complete(rtnl_socket, msg);
 834         nlmsg_free(msg);
 835
 836         if (ret < 0)
 837                 return ret;
 838
 839         return nl_wait_for_ack(rtnl_socket);
 840 }
 841
 842 void netlink_dump_neigh_table(const bool proxy)
 843 {
 844         struct nl_msg *msg;
 845         struct ndmsg ndm = {
 846                 .ndm_family = AF_INET6,
 847                 .ndm_flags = proxy ? NTF_PROXY : 0,
 848         };
 849
 850         msg = nlmsg_alloc_simple(RTM_GETNEIGH, NLM_F_REQUEST | NLM_F_DUMP);
 851         if (!msg)
 852                 return;
 853
 854         nlmsg_append(msg, &ndm, sizeof(ndm), 0);
 855
 856         nl_send_auto_complete(rtnl_event.sock, msg);
 857
 858         nlmsg_free(msg);
 859 }
 860
 861 void netlink_dump_addr_table(const bool v6)
 862 {
 863         struct nl_msg *msg;
 864         struct ifaddrmsg ifa = {
 865                 .ifa_family = v6 ? AF_INET6 : AF_INET,
 866         };
 867
 868         msg = nlmsg_alloc_simple(RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP);
 869         if (!msg)
 870                 return;
 871
 872         nlmsg_append(msg, &ifa, sizeof(ifa), 0);
 873
 874         nl_send_auto_complete(rtnl_event.sock, msg);
 875
 876         nlmsg_free(msg);
 877 }