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(addr);
 216                 return;
 217         }
 218
 219         avl_for_element_range(iface, avl_last_element(&interfaces, iface, avl), iface, avl) {
 220                 struct netevent_handler_info event_info;
 221
 222                 if (iface->ifindex != ifindex)
 223                         continue;
 224
 225                 memset(&event_info, 0, sizeof(event_info));
 226                 event_info.iface = iface;
 227                 event_info.addrs_old.addrs = iface->addr6;
 228                 event_info.addrs_old.len = iface->addr6_len;
 229
 230                 iface->addr6 = addr;
 231                 iface->addr6_len = len;
 232
 233                 call_netevent_handler_list(NETEV_ADDR6LIST_CHANGE, &event_info);
 234
 235                 free(event_info.addrs_old.addrs);
 236
 237                 if (len) {
 238                         addr = malloc(len * sizeof(*addr));
 239                         if (!addr)
 240                             return;
 241
 242                         memcpy(addr, iface->addr6, len * sizeof(*addr));
 243                 }
 244         }
 245
 246         free(addr);
 247 }
 248
 249 static int handle_rtm_link(struct nlmsghdr *hdr)
 250 {
 251         struct ifinfomsg *ifi = nlmsg_data(hdr);
 252         struct nlattr *nla[__IFLA_MAX];
 253         struct interface *iface;
 254         struct netevent_handler_info event_info;
 255         const char *ifname;
 256
 257         memset(&event_info, 0, sizeof(event_info));
 258
 259         if (!nlmsg_valid_hdr(hdr, sizeof(*ifi)) || ifi->ifi_family != AF_UNSPEC)
 260                 return NL_SKIP;
 261
 262         nlmsg_parse(hdr, sizeof(*ifi), nla, __IFLA_MAX - 1, NULL);
 263         if (!nla[IFLA_IFNAME])
 264                 return NL_SKIP;
 265
 266         ifname = nla_get_string(nla[IFLA_IFNAME]);
 267
 268         avl_for_each_element(&interfaces, iface, avl) {
 269                 if (strcmp(iface->ifname, ifname) || iface->ifindex == ifi->ifi_index)
 270                         continue;
 271
 272                 iface->ifindex = ifi->ifi_index;
 273                 event_info.iface = iface;
 274                 call_netevent_handler_list(NETEV_IFINDEX_CHANGE, &event_info);
 275         }
 276
 277         return NL_OK;
 278 }
 279
 280 static int handle_rtm_route(struct nlmsghdr *hdr, bool add)
 281 {
 282         struct rtmsg *rtm = nlmsg_data(hdr);
 283         struct nlattr *nla[__RTA_MAX];
 284         struct interface *iface;
 285         struct netevent_handler_info event_info;
 286         int ifindex = 0;
 287
 288         if (!nlmsg_valid_hdr(hdr, sizeof(*rtm)) || rtm->rtm_family != AF_INET6)
 289                 return NL_SKIP;
 290
 291         nlmsg_parse(hdr, sizeof(*rtm), nla, __RTA_MAX - 1, NULL);
 292
 293         memset(&event_info, 0, sizeof(event_info));
 294         event_info.rt.dst_len = rtm->rtm_dst_len;
 295
 296         if (nla[RTA_DST])
 297                 nla_memcpy(&event_info.rt.dst, nla[RTA_DST],
 298                                 sizeof(event_info.rt.dst));
 299
 300         if (nla[RTA_OIF])
 301                 ifindex = nla_get_u32(nla[RTA_OIF]);
 302
 303         if (nla[RTA_GATEWAY])
 304                 nla_memcpy(&event_info.rt.gateway, nla[RTA_GATEWAY],
 305                                 sizeof(event_info.rt.gateway));
 306
 307         avl_for_each_element(&interfaces, iface, avl) {
 308                 if (ifindex && iface->ifindex != ifindex)
 309                         continue;
 310
 311                 event_info.iface = ifindex ? iface : NULL;
 312                 call_netevent_handler_list(add ? NETEV_ROUTE6_ADD : NETEV_ROUTE6_DEL,
 313                                                 &event_info);
 314         }
 315
 316         return NL_OK;
 317 }
 318
 319 static int handle_rtm_addr(struct nlmsghdr *hdr, bool add)
 320 {
 321         struct ifaddrmsg *ifa = nlmsg_data(hdr);
 322         struct nlattr *nla[__IFA_MAX];
 323         struct interface *iface;
 324         struct netevent_handler_info event_info;
 325         char buf[INET6_ADDRSTRLEN];
 326
 327         if (!nlmsg_valid_hdr(hdr, sizeof(*ifa)) ||
 328                         (ifa->ifa_family != AF_INET6 &&
 329                          ifa->ifa_family != AF_INET))
 330                 return NL_SKIP;
 331
 332         memset(&event_info, 0, sizeof(event_info));
 333
 334         nlmsg_parse(hdr, sizeof(*ifa), nla, __IFA_MAX - 1, NULL);
 335
 336         if (ifa->ifa_family == AF_INET6) {
 337                 if (!nla[IFA_ADDRESS])
 338                         return NL_SKIP;
 339
 340                 nla_memcpy(&event_info.addr, nla[IFA_ADDRESS], sizeof(event_info.addr));
 341
 342                 if (IN6_IS_ADDR_LINKLOCAL(&event_info.addr) || IN6_IS_ADDR_MULTICAST(&event_info.addr))
 343                         return NL_SKIP;
 344
 345                 inet_ntop(AF_INET6, &event_info.addr, buf, sizeof(buf));
 346
 347                 avl_for_each_element(&interfaces, iface, avl) {
 348                         if (iface->ifindex != (int)ifa->ifa_index)
 349                                 continue;
 350
 351                         syslog(LOG_DEBUG, "Netlink %s %s on %s", add ? "newaddr" : "deladdr",
 352                                         buf, iface->name);
 353
 354                         event_info.iface = iface;
 355                         call_netevent_handler_list(add ? NETEV_ADDR6_ADD : NETEV_ADDR6_DEL,
 356                                                         &event_info);
 357                 }
 358
 359                 refresh_iface_addr6(ifa->ifa_index);
 360         } else {
 361                 if (!nla[IFA_LOCAL])
 362                         return NL_SKIP;
 363
 364                 nla_memcpy(&event_info.addr, nla[IFA_LOCAL], sizeof(event_info.addr));
 365
 366                 inet_ntop(AF_INET, &event_info.addr, buf, sizeof(buf));
 367
 368                 avl_for_each_element(&interfaces, iface, avl) {
 369                         if (iface->ifindex != (int)ifa->ifa_index)
 370                                 continue;
 371
 372                         syslog(LOG_DEBUG, "Netlink %s %s on %s", add ? "newaddr" : "deladdr",
 373                                         buf, iface->name);
 374
 375                         event_info.iface = iface;
 376                         call_netevent_handler_list(add ? NETEV_ADDR_ADD : NETEV_ADDR_DEL,
 377                                                         &event_info);
 378                 }
 379
 380                 refresh_iface_addr4(ifa->ifa_index);
 381         }
 382
 383         return NL_OK;
 384 }
 385
 386 static int handle_rtm_neigh(struct nlmsghdr *hdr, bool add)
 387 {
 388         struct ndmsg *ndm = nlmsg_data(hdr);
 389         struct nlattr *nla[__NDA_MAX];
 390         struct interface *iface;
 391         struct netevent_handler_info event_info;
 392         char buf[INET6_ADDRSTRLEN];
 393
 394         if (!nlmsg_valid_hdr(hdr, sizeof(*ndm)) ||
 395                         ndm->ndm_family != AF_INET6)
 396                 return NL_SKIP;
 397
 398         nlmsg_parse(hdr, sizeof(*ndm), nla, __NDA_MAX - 1, NULL);
 399         if (!nla[NDA_DST])
 400                 return NL_SKIP;
 401
 402         memset(&event_info, 0, sizeof(event_info));
 403
 404         nla_memcpy(&event_info.neigh.dst, nla[NDA_DST], sizeof(event_info.neigh.dst));
 405
 406         if (IN6_IS_ADDR_LINKLOCAL(&event_info.neigh.dst) ||
 407                         IN6_IS_ADDR_MULTICAST(&event_info.neigh.dst))
 408                 return NL_SKIP;
 409
 410         inet_ntop(AF_INET6, &event_info.neigh.dst, buf, sizeof(buf));
 411
 412         avl_for_each_element(&interfaces, iface, avl) {
 413                 if (iface->ifindex != ndm->ndm_ifindex)
 414                         continue;
 415
 416                 syslog(LOG_DEBUG, "Netlink %s %s on %s", true ? "newneigh" : "delneigh",
 417                                 buf, iface->name);
 418
 419                 event_info.iface = iface;
 420                 event_info.neigh.state = ndm->ndm_state;
 421                 event_info.neigh.flags = ndm->ndm_flags;
 422
 423                 call_netevent_handler_list(add ? NETEV_NEIGH6_ADD : NETEV_NEIGH6_DEL,
 424                                                 &event_info);
 425         }
 426
 427         return NL_OK;
 428 }
 429
 430 /* Handler for neighbor cache entries from the kernel. This is our source
 431  * to learn and unlearn hosts on interfaces. */
 432 static int cb_rtnl_valid(struct nl_msg *msg, _unused void *arg)
 433 {
 434         struct nlmsghdr *hdr = nlmsg_hdr(msg);
 435         int ret = NL_SKIP;
 436         bool add = false;
 437
 438         switch (hdr->nlmsg_type) {
 439         case RTM_NEWLINK:
 440                 ret = handle_rtm_link(hdr);
 441                 break;
 442
 443         case RTM_NEWROUTE:
 444                 add = true;
 445                 /* fall through */
 446         case RTM_DELROUTE:
 447                 ret = handle_rtm_route(hdr, add);
 448                 break;
 449
 450         case RTM_NEWADDR:
 451                 add = true;
 452                 /* fall through */
 453         case RTM_DELADDR:
 454                 ret = handle_rtm_addr(hdr, add);
 455                 break;
 456
 457         case RTM_NEWNEIGH:
 458                 add = true;
 459                 /* fall through */
 460         case RTM_DELNEIGH:
 461                 ret = handle_rtm_neigh(hdr, add);
 462                 break;
 463
 464         default:
 465                 break;
 466         }
 467
 468         return ret;
 469 }
 470
 471 static void catch_rtnl_err(struct odhcpd_event *e, int error)
 472 {
 473         struct event_socket *ev_sock = container_of(e, struct event_socket, ev);
 474
 475         if (error != ENOBUFS)
 476                 goto err;
 477
 478         /* Double netlink event buffer size */
 479         ev_sock->sock_bufsize *= 2;
 480
 481         if (nl_socket_set_buffer_size(ev_sock->sock, ev_sock->sock_bufsize, 0))
 482                 goto err;
 483
 484         netlink_dump_addr_table(true);
 485         return;
 486
 487 err:
 488         odhcpd_deregister(e);
 489 }
 490
 491 static struct nl_sock *create_socket(int protocol)
 492 {
 493         struct nl_sock *nl_sock;
 494
 495         nl_sock = nl_socket_alloc();
 496         if (!nl_sock)
 497                 goto err;
 498
 499         if (nl_connect(nl_sock, protocol) < 0)
 500                 goto err;
 501
 502         return nl_sock;
 503
 504 err:
 505         if (nl_sock)
 506                 nl_socket_free(nl_sock);
 507
 508         return NULL;
 509 }
 510
 511
 512 struct addr_info {
 513         int ifindex;
 514         int af;
 515         struct odhcpd_ipaddr **addrs;
 516         int pending;
 517         ssize_t ret;
 518 };
 519
 520
 521 static int cb_valid_handler(struct nl_msg *msg, void *arg)
 522 {
 523         struct addr_info *ctxt = (struct addr_info *)arg;
 524         struct odhcpd_ipaddr *addrs = *(ctxt->addrs);
 525         struct nlmsghdr *hdr = nlmsg_hdr(msg);
 526         struct ifaddrmsg *ifa;
 527         struct nlattr *nla[__IFA_MAX], *nla_addr = NULL;
 528
 529         if (hdr->nlmsg_type != RTM_NEWADDR)
 530                 return NL_SKIP;
 531
 532         ifa = NLMSG_DATA(hdr);
 533         if (ifa->ifa_scope != RT_SCOPE_UNIVERSE ||
 534                         (ctxt->af != ifa->ifa_family) ||
 535                         (ctxt->ifindex && ifa->ifa_index != (unsigned)ctxt->ifindex))
 536                 return NL_SKIP;
 537
 538         nlmsg_parse(hdr, sizeof(*ifa), nla, __IFA_MAX - 1, NULL);
 539
 540         switch (ifa->ifa_family) {
 541         case AF_INET6:
 542                 if (nla[IFA_ADDRESS])
 543                         nla_addr = nla[IFA_ADDRESS];
 544                 break;
 545
 546         case AF_INET:
 547                 if (nla[IFA_LOCAL])
 548                         nla_addr = nla[IFA_LOCAL];
 549                 break;
 550
 551         default:
 552                 break;
 553         }
 554         if (!nla_addr)
 555                 return NL_SKIP;
 556
 557         addrs = realloc(addrs, sizeof(*addrs)*(ctxt->ret + 1));
 558         if (!addrs)
 559                 return NL_SKIP;
 560
 561         memset(&addrs[ctxt->ret], 0, sizeof(addrs[ctxt->ret]));
 562         addrs[ctxt->ret].prefix = ifa->ifa_prefixlen;
 563
 564         nla_memcpy(&addrs[ctxt->ret].addr, nla_addr,
 565                         sizeof(addrs[ctxt->ret].addr));
 566
 567         if (nla[IFA_BROADCAST])
 568                 nla_memcpy(&addrs[ctxt->ret].broadcast, nla[IFA_BROADCAST],
 569                                 sizeof(addrs[ctxt->ret].broadcast));
 570
 571         if (nla[IFA_CACHEINFO]) {
 572                 struct ifa_cacheinfo *ifc = nla_data(nla[IFA_CACHEINFO]);
 573
 574                 addrs[ctxt->ret].preferred = ifc->ifa_prefered;
 575                 addrs[ctxt->ret].valid = ifc->ifa_valid;
 576         }
 577
 578         if (ifa->ifa_flags & IFA_F_DEPRECATED)
 579                 addrs[ctxt->ret].preferred = 0;
 580
 581         ctxt->ret++;
 582         *(ctxt->addrs) = addrs;
 583
 584         return NL_OK;
 585 }
 586
 587
 588 static int cb_finish_handler(_unused struct nl_msg *msg, void *arg)
 589 {
 590         struct addr_info *ctxt = (struct addr_info *)arg;
 591
 592         ctxt->pending = 0;
 593
 594         return NL_STOP;
 595 }
 596
 597
 598 static int cb_error_handler(_unused struct sockaddr_nl *nla, struct nlmsgerr *err,
 599                 void *arg)
 600 {
 601         struct addr_info *ctxt = (struct addr_info *)arg;
 602
 603         ctxt->pending = 0;
 604         ctxt->ret = err->error;
 605
 606         return NL_STOP;
 607 }
 608
 609
 610 static int prefix_cmp(const void *va, const void *vb)
 611 {
 612         const struct odhcpd_ipaddr *a = va, *b = vb;
 613         int ret = 0;
 614
 615         if (a->prefix == b->prefix) {
 616                 ret = (ntohl(a->addr.in.s_addr) < ntohl(b->addr.in.s_addr)) ? 1 :
 617                         (ntohl(a->addr.in.s_addr) > ntohl(b->addr.in.s_addr)) ? -1 : 0;
 618         } else
 619                 ret = a->prefix < b->prefix ? 1 : -1;
 620
 621         return ret;
 622 }
 623
 624
 625 /* compare IPv6 prefixes */
 626 static int prefix6_cmp(const void *va, const void *vb)
 627 {
 628         const struct odhcpd_ipaddr *a = va, *b = vb;
 629         uint32_t a_pref = IN6_IS_ADDR_ULA(&a->addr.in6) ? 1 : a->preferred;
 630         uint32_t b_pref = IN6_IS_ADDR_ULA(&b->addr.in6) ? 1 : b->preferred;
 631         return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
 632 }
 633
 634
 635 /* Detect an IPV6-address currently assigned to the given interface */
 636 ssize_t netlink_get_interface_addrs(int ifindex, bool v6, struct odhcpd_ipaddr **addrs)
 637 {
 638         struct nl_msg *msg;
 639         struct ifaddrmsg ifa = {
 640                 .ifa_family = v6? AF_INET6: AF_INET,
 641                 .ifa_prefixlen = 0,
 642                 .ifa_flags = 0,
 643                 .ifa_scope = 0,
 644                 .ifa_index = ifindex, };
 645         struct nl_cb *cb = nl_cb_alloc(NL_CB_DEFAULT);
 646         struct addr_info ctxt = {
 647                 .ifindex = ifindex,
 648                 .af = v6? AF_INET6: AF_INET,
 649                 .addrs = addrs,
 650                 .ret = 0,
 651                 .pending = 1,
 652         };
 653
 654         if (!cb) {
 655                 ctxt.ret = -1;
 656                 goto out;
 657         }
 658
 659         msg = nlmsg_alloc_simple(RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP);
 660
 661         if (!msg) {
 662                 ctxt.ret = - 1;
 663                 goto out;
 664         }
 665
 666         nlmsg_append(msg, &ifa, sizeof(ifa), 0);
 667
 668         nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, cb_valid_handler, &ctxt);
 669         nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, cb_finish_handler, &ctxt);
 670         nl_cb_err(cb, NL_CB_CUSTOM, cb_error_handler, &ctxt);
 671
 672         nl_send_auto_complete(rtnl_socket, msg);
 673         while (ctxt.pending > 0)
 674                 nl_recvmsgs(rtnl_socket, cb);
 675
 676         nlmsg_free(msg);
 677
 678         if (ctxt.ret <= 0)
 679                 goto out;
 680
 681         time_t now = odhcpd_time();
 682         struct odhcpd_ipaddr *addr = *addrs;
 683
 684         qsort(addr, ctxt.ret, sizeof(*addr), v6 ? prefix6_cmp : prefix_cmp);
 685
 686         for (ssize_t i = 0; i < ctxt.ret; ++i) {
 687                 if (addr[i].preferred < UINT32_MAX - now)
 688                         addr[i].preferred += now;
 689
 690                 if (addr[i].valid < UINT32_MAX - now)
 691                         addr[i].valid += now;
 692         }
 693
 694 out:
 695         nl_cb_put(cb);
 696
 697         return ctxt.ret;
 698 }
 699
 700
 701 int netlink_setup_route(const struct in6_addr *addr, const int prefixlen,
 702                 const int ifindex, const struct in6_addr *gw,
 703                 const uint32_t metric, const bool add)
 704 {
 705         struct nl_msg *msg;
 706         struct rtmsg rtm = {
 707                 .rtm_family = AF_INET6,
 708                 .rtm_dst_len = prefixlen,
 709                 .rtm_src_len = 0,
 710                 .rtm_table = RT_TABLE_MAIN,
 711                 .rtm_protocol = (add ? RTPROT_STATIC : RTPROT_UNSPEC),
 712                 .rtm_scope = (add ? (gw ? RT_SCOPE_UNIVERSE : RT_SCOPE_LINK) : RT_SCOPE_NOWHERE),
 713                 .rtm_type = (add ? RTN_UNICAST : RTN_UNSPEC),
 714         };
 715         int ret = 0;
 716
 717         msg = nlmsg_alloc_simple(add ? RTM_NEWROUTE : RTM_DELROUTE,
 718                                         add ? NLM_F_CREATE | NLM_F_REPLACE : 0);
 719         if (!msg)
 720                 return -1;
 721
 722         nlmsg_append(msg, &rtm, sizeof(rtm), 0);
 723
 724         nla_put(msg, RTA_DST, sizeof(*addr), addr);
 725         nla_put_u32(msg, RTA_OIF, ifindex);
 726         nla_put_u32(msg, RTA_PRIORITY, metric);
 727
 728         if (gw)
 729                 nla_put(msg, RTA_GATEWAY, sizeof(*gw), gw);
 730
 731         ret = nl_send_auto_complete(rtnl_socket, msg);
 732         nlmsg_free(msg);
 733
 734         if (ret < 0)
 735                 return ret;
 736
 737         return nl_wait_for_ack(rtnl_socket);
 738 }
 739
 740
 741 int netlink_setup_proxy_neigh(const struct in6_addr *addr,
 742                 const int ifindex, const bool add)
 743 {
 744         struct nl_msg *msg;
 745         struct ndmsg ndm = {
 746                 .ndm_family = AF_INET6,
 747                 .ndm_flags = NTF_PROXY,
 748                 .ndm_ifindex = ifindex,
 749         };
 750         int ret = 0, flags = NLM_F_REQUEST;
 751
 752         if (add)
 753                 flags |= NLM_F_REPLACE | NLM_F_CREATE;
 754
 755         msg = nlmsg_alloc_simple(add ? RTM_NEWNEIGH : RTM_DELNEIGH, flags);
 756         if (!msg)
 757                 return -1;
 758
 759         nlmsg_append(msg, &ndm, sizeof(ndm), 0);
 760
 761         nla_put(msg, NDA_DST, sizeof(*addr), addr);
 762
 763         ret = nl_send_auto_complete(rtnl_socket, msg);
 764         nlmsg_free(msg);
 765
 766         if (ret < 0)
 767                 return ret;
 768
 769         return nl_wait_for_ack(rtnl_socket);
 770 }
 771
 772
 773 int netlink_setup_addr(struct odhcpd_ipaddr *addr,
 774                 const int ifindex, const bool v6, const bool add)
 775 {
 776         struct nl_msg *msg;
 777         struct ifaddrmsg ifa = {
 778                 .ifa_family = v6 ? AF_INET6 : AF_INET,
 779                 .ifa_prefixlen = addr->prefix,
 780                 .ifa_flags = 0,
 781                 .ifa_scope = 0,
 782                 .ifa_index = ifindex, };
 783         int ret = 0, flags = NLM_F_REQUEST;
 784
 785         if (add)
 786                 flags |= NLM_F_REPLACE | NLM_F_CREATE;
 787
 788         msg = nlmsg_alloc_simple(add ? RTM_NEWADDR : RTM_DELADDR, 0);
 789         if (!msg)
 790                 return -1;
 791
 792         nlmsg_append(msg, &ifa, sizeof(ifa), flags);
 793         nla_put(msg, IFA_LOCAL, v6 ? 16 : 4, &addr->addr);
 794         if (v6) {
 795                 struct ifa_cacheinfo cinfo = {  .ifa_prefered = 0xffffffffU,
 796                                                 .ifa_valid = 0xffffffffU,
 797                                                 .cstamp = 0,
 798                                                 .tstamp = 0 };
 799                 time_t now = odhcpd_time();
 800
 801                 if (addr->preferred) {
 802                         int64_t preferred = addr->preferred - now;
 803                         if (preferred < 0)
 804                                 preferred = 0;
 805                         else if (preferred > UINT32_MAX)
 806                                 preferred = UINT32_MAX;
 807
 808                         cinfo.ifa_prefered = preferred;
 809                 }
 810
 811                 if (addr->valid) {
 812                         int64_t valid = addr->valid - now;
 813                         if (valid <= 0) {
 814                                 nlmsg_free(msg);
 815                                 return -1;
 816                         }
 817                         else if (valid > UINT32_MAX)
 818                                 valid = UINT32_MAX;
 819
 820                         cinfo.ifa_valid = valid;
 821                 }
 822
 823                 nla_put(msg, IFA_CACHEINFO, sizeof(cinfo), &cinfo);
 824
 825                 nla_put_u32(msg, IFA_FLAGS, IFA_F_NOPREFIXROUTE);
 826         } else {
 827                 if (addr->broadcast.s_addr)
 828                         nla_put_u32(msg, IFA_BROADCAST, addr->broadcast.s_addr);
 829         }
 830
 831         ret = nl_send_auto_complete(rtnl_socket, msg);
 832         nlmsg_free(msg);
 833
 834         if (ret < 0)
 835                 return ret;
 836
 837         return nl_wait_for_ack(rtnl_socket);
 838 }
 839
 840 void netlink_dump_neigh_table(const bool proxy)
 841 {
 842         struct nl_msg *msg;
 843         struct ndmsg ndm = {
 844                 .ndm_family = AF_INET6,
 845                 .ndm_flags = proxy ? NTF_PROXY : 0,
 846         };
 847
 848         msg = nlmsg_alloc_simple(RTM_GETNEIGH, NLM_F_REQUEST | NLM_F_DUMP);
 849         if (!msg)
 850                 return;
 851
 852         nlmsg_append(msg, &ndm, sizeof(ndm), 0);
 853
 854         nl_send_auto_complete(rtnl_event.sock, msg);
 855
 856         nlmsg_free(msg);
 857 }
 858
 859 void netlink_dump_addr_table(const bool v6)
 860 {
 861         struct nl_msg *msg;
 862         struct ifaddrmsg ifa = {
 863                 .ifa_family = v6 ? AF_INET6 : AF_INET,
 864         };
 865
 866         msg = nlmsg_alloc_simple(RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP);
 867         if (!msg)
 868                 return;
 869
 870         nlmsg_append(msg, &ifa, sizeof(ifa), 0);
 871
 872         nl_send_auto_complete(rtnl_event.sock, msg);
 873
 874         nlmsg_free(msg);
 875 }