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                 struct netevent_handler_info event_info;
 144
 145                 if (iface->ifindex != ifindex)
 146                         continue;
 147
 148                 memset(&event_info, 0, sizeof(event_info));
 149                 event_info.iface = iface;
 150                 event_info.addrs_old.addrs = iface->addr4;
 151                 event_info.addrs_old.len = iface->addr4_len;
 152
 153                 if (!change) {
 154                         change = len != (ssize_t)iface->addr4_len;
 155                         for (ssize_t i = 0; !change && i < len; ++i) {
 156                                 if (addr[i].addr.in.s_addr != iface->addr4[i].addr.in.s_addr)
 157                                         change = true;
 158                         }
 159                 }
 160
 161                 iface->addr4 = addr;
 162                 iface->addr4_len = len;
 163
 164                 if (change)
 165                         call_netevent_handler_list(NETEV_ADDRLIST_CHANGE, &event_info);
 166
 167                 free(event_info.addrs_old.addrs);
 168
 169                 if (!len)
 170                         continue;
 171
 172                 addr = malloc(len * sizeof(*addr));
 173                 if (!addr)
 174                         break;
 175
 176                 memcpy(addr, iface->addr4, len * sizeof(*addr));
 177         }
 178
 179         free(addr);
 180 }
 181
 182 static void refresh_iface_addr6(int ifindex)
 183 {
 184         struct odhcpd_ipaddr *addr = NULL;
 185         struct interface *iface;
 186         ssize_t len = netlink_get_interface_addrs(ifindex, true, &addr);
 187         time_t now = odhcpd_time();
 188         bool change = false;
 189
 190         if (len < 0)
 191                 return;
 192
 193         avl_for_each_element(&interfaces, iface, avl) {
 194                 struct netevent_handler_info event_info;
 195
 196                 if (iface->ifindex != ifindex)
 197                         continue;
 198
 199                 memset(&event_info, 0, sizeof(event_info));
 200                 event_info.iface = iface;
 201                 event_info.addrs_old.addrs = iface->addr6;
 202                 event_info.addrs_old.len = iface->addr6_len;
 203
 204                 if (!change) {
 205                         change = len != (ssize_t)iface->addr6_len;
 206                         for (ssize_t i = 0; !change && i < len; ++i) {
 207                                 if (!IN6_ARE_ADDR_EQUAL(&addr[i].addr.in6, &iface->addr6[i].addr.in6) ||
 208                                     (addr[i].preferred > (uint32_t)now) != (iface->addr6[i].preferred > (uint32_t)now) ||
 209                                     addr[i].valid < iface->addr6[i].valid || addr[i].preferred < iface->addr6[i].preferred)
 210                                         change = true;
 211                         }
 212                 }
 213
 214                 iface->addr6 = addr;
 215                 iface->addr6_len = len;
 216
 217                 if (change)
 218                         call_netevent_handler_list(NETEV_ADDR6LIST_CHANGE, &event_info);
 219
 220                 free(event_info.addrs_old.addrs);
 221
 222                 if (!len)
 223                         continue;
 224
 225                 addr = malloc(len * sizeof(*addr));
 226                 if (!addr)
 227                         break;
 228
 229                 memcpy(addr, iface->addr6, len * sizeof(*addr));
 230         }
 231
 232         free(addr);
 233 }
 234
 235 static int handle_rtm_link(struct nlmsghdr *hdr)
 236 {
 237         struct ifinfomsg *ifi = nlmsg_data(hdr);
 238         struct nlattr *nla[__IFLA_MAX];
 239         struct interface *iface;
 240         struct netevent_handler_info event_info;
 241         const char *ifname;
 242
 243         memset(&event_info, 0, sizeof(event_info));
 244
 245         if (!nlmsg_valid_hdr(hdr, sizeof(*ifi)) || ifi->ifi_family != AF_UNSPEC)
 246                 return NL_SKIP;
 247
 248         nlmsg_parse(hdr, sizeof(*ifi), nla, __IFLA_MAX - 1, NULL);
 249         if (!nla[IFLA_IFNAME])
 250                 return NL_SKIP;
 251
 252         ifname = nla_get_string(nla[IFLA_IFNAME]);
 253
 254         avl_for_each_element(&interfaces, iface, avl) {
 255                 if (strcmp(iface->ifname, ifname) || iface->ifindex == ifi->ifi_index)
 256                         continue;
 257
 258                 iface->ifindex = ifi->ifi_index;
 259                 event_info.iface = iface;
 260                 call_netevent_handler_list(NETEV_IFINDEX_CHANGE, &event_info);
 261         }
 262
 263         return NL_OK;
 264 }
 265
 266 static int handle_rtm_route(struct nlmsghdr *hdr, bool add)
 267 {
 268         struct rtmsg *rtm = nlmsg_data(hdr);
 269         struct nlattr *nla[__RTA_MAX];
 270         struct interface *iface;
 271         struct netevent_handler_info event_info;
 272         int ifindex = 0;
 273
 274         if (!nlmsg_valid_hdr(hdr, sizeof(*rtm)) || rtm->rtm_family != AF_INET6)
 275                 return NL_SKIP;
 276
 277         nlmsg_parse(hdr, sizeof(*rtm), nla, __RTA_MAX - 1, NULL);
 278
 279         memset(&event_info, 0, sizeof(event_info));
 280         event_info.rt.dst_len = rtm->rtm_dst_len;
 281
 282         if (nla[RTA_DST])
 283                 nla_memcpy(&event_info.rt.dst, nla[RTA_DST],
 284                                 sizeof(event_info.rt.dst));
 285
 286         if (nla[RTA_OIF])
 287                 ifindex = nla_get_u32(nla[RTA_OIF]);
 288
 289         if (nla[RTA_GATEWAY])
 290                 nla_memcpy(&event_info.rt.gateway, nla[RTA_GATEWAY],
 291                                 sizeof(event_info.rt.gateway));
 292
 293         avl_for_each_element(&interfaces, iface, avl) {
 294                 if (ifindex && iface->ifindex != ifindex)
 295                         continue;
 296
 297                 event_info.iface = ifindex ? iface : NULL;
 298                 call_netevent_handler_list(add ? NETEV_ROUTE6_ADD : NETEV_ROUTE6_DEL,
 299                                                 &event_info);
 300         }
 301
 302         return NL_OK;
 303 }
 304
 305 static int handle_rtm_addr(struct nlmsghdr *hdr, bool add)
 306 {
 307         struct ifaddrmsg *ifa = nlmsg_data(hdr);
 308         struct nlattr *nla[__IFA_MAX];
 309         struct interface *iface;
 310         struct netevent_handler_info event_info;
 311         char buf[INET6_ADDRSTRLEN];
 312
 313         if (!nlmsg_valid_hdr(hdr, sizeof(*ifa)) ||
 314                         (ifa->ifa_family != AF_INET6 &&
 315                          ifa->ifa_family != AF_INET))
 316                 return NL_SKIP;
 317
 318         memset(&event_info, 0, sizeof(event_info));
 319
 320         nlmsg_parse(hdr, sizeof(*ifa), nla, __IFA_MAX - 1, NULL);
 321
 322         if (ifa->ifa_family == AF_INET6) {
 323                 if (!nla[IFA_ADDRESS])
 324                         return NL_SKIP;
 325
 326                 nla_memcpy(&event_info.addr, nla[IFA_ADDRESS], sizeof(event_info.addr));
 327
 328                 if (IN6_IS_ADDR_LINKLOCAL(&event_info.addr) || IN6_IS_ADDR_MULTICAST(&event_info.addr))
 329                         return NL_SKIP;
 330
 331                 inet_ntop(AF_INET6, &event_info.addr, buf, sizeof(buf));
 332
 333                 avl_for_each_element(&interfaces, iface, avl) {
 334                         if (iface->ifindex != (int)ifa->ifa_index)
 335                                 continue;
 336
 337                         syslog(LOG_DEBUG, "Netlink %s %s on %s", add ? "newaddr" : "deladdr",
 338                                         buf, iface->name);
 339
 340                         event_info.iface = iface;
 341                         call_netevent_handler_list(add ? NETEV_ADDR6_ADD : NETEV_ADDR6_DEL,
 342                                                         &event_info);
 343                 }
 344
 345                 refresh_iface_addr6(ifa->ifa_index);
 346         } else {
 347                 if (!nla[IFA_LOCAL])
 348                         return NL_SKIP;
 349
 350                 nla_memcpy(&event_info.addr, nla[IFA_LOCAL], sizeof(event_info.addr));
 351
 352                 inet_ntop(AF_INET, &event_info.addr, buf, sizeof(buf));
 353
 354                 avl_for_each_element(&interfaces, iface, avl) {
 355                         if (iface->ifindex != (int)ifa->ifa_index)
 356                                 continue;
 357
 358                         syslog(LOG_DEBUG, "Netlink %s %s on %s", add ? "newaddr" : "deladdr",
 359                                         buf, iface->name);
 360
 361                         event_info.iface = iface;
 362                         call_netevent_handler_list(add ? NETEV_ADDR_ADD : NETEV_ADDR_DEL,
 363                                                         &event_info);
 364                 }
 365
 366                 refresh_iface_addr4(ifa->ifa_index);
 367         }
 368
 369         return NL_OK;
 370 }
 371
 372 static int handle_rtm_neigh(struct nlmsghdr *hdr, bool add)
 373 {
 374         struct ndmsg *ndm = nlmsg_data(hdr);
 375         struct nlattr *nla[__NDA_MAX];
 376         struct interface *iface;
 377         struct netevent_handler_info event_info;
 378         char buf[INET6_ADDRSTRLEN];
 379
 380         if (!nlmsg_valid_hdr(hdr, sizeof(*ndm)) ||
 381                         ndm->ndm_family != AF_INET6)
 382                 return NL_SKIP;
 383
 384         nlmsg_parse(hdr, sizeof(*ndm), nla, __NDA_MAX - 1, NULL);
 385         if (!nla[NDA_DST])
 386                 return NL_SKIP;
 387
 388         memset(&event_info, 0, sizeof(event_info));
 389
 390         nla_memcpy(&event_info.neigh.dst, nla[NDA_DST], sizeof(event_info.neigh.dst));
 391
 392         if (IN6_IS_ADDR_LINKLOCAL(&event_info.neigh.dst) ||
 393                         IN6_IS_ADDR_MULTICAST(&event_info.neigh.dst))
 394                 return NL_SKIP;
 395
 396         inet_ntop(AF_INET6, &event_info.neigh.dst, buf, sizeof(buf));
 397
 398         avl_for_each_element(&interfaces, iface, avl) {
 399                 if (iface->ifindex != ndm->ndm_ifindex)
 400                         continue;
 401
 402                 syslog(LOG_DEBUG, "Netlink %s %s on %s", true ? "newneigh" : "delneigh",
 403                                 buf, iface->name);
 404
 405                 event_info.iface = iface;
 406                 event_info.neigh.state = ndm->ndm_state;
 407                 event_info.neigh.flags = ndm->ndm_flags;
 408
 409                 call_netevent_handler_list(add ? NETEV_NEIGH6_ADD : NETEV_NEIGH6_DEL,
 410                                                 &event_info);
 411         }
 412
 413         return NL_OK;
 414 }
 415
 416 /* Handler for neighbor cache entries from the kernel. This is our source
 417  * to learn and unlearn hosts on interfaces. */
 418 static int cb_rtnl_valid(struct nl_msg *msg, _unused void *arg)
 419 {
 420         struct nlmsghdr *hdr = nlmsg_hdr(msg);
 421         int ret = NL_SKIP;
 422         bool add = false;
 423
 424         switch (hdr->nlmsg_type) {
 425         case RTM_NEWLINK:
 426                 ret = handle_rtm_link(hdr);
 427                 break;
 428
 429         case RTM_NEWROUTE:
 430                 add = true;
 431                 /* fall through */
 432         case RTM_DELROUTE:
 433                 ret = handle_rtm_route(hdr, add);
 434                 break;
 435
 436         case RTM_NEWADDR:
 437                 add = true;
 438                 /* fall through */
 439         case RTM_DELADDR:
 440                 ret = handle_rtm_addr(hdr, add);
 441                 break;
 442
 443         case RTM_NEWNEIGH:
 444                 add = true;
 445                 /* fall through */
 446         case RTM_DELNEIGH:
 447                 ret = handle_rtm_neigh(hdr, add);
 448                 break;
 449
 450         default:
 451                 break;
 452         }
 453
 454         return ret;
 455 }
 456
 457 static void catch_rtnl_err(struct odhcpd_event *e, int error)
 458 {
 459         struct event_socket *ev_sock = container_of(e, struct event_socket, ev);
 460
 461         if (error != ENOBUFS)
 462                 goto err;
 463
 464         /* Double netlink event buffer size */
 465         ev_sock->sock_bufsize *= 2;
 466
 467         if (nl_socket_set_buffer_size(ev_sock->sock, ev_sock->sock_bufsize, 0))
 468                 goto err;
 469
 470         netlink_dump_addr_table(true);
 471         return;
 472
 473 err:
 474         odhcpd_deregister(e);
 475 }
 476
 477 static struct nl_sock *create_socket(int protocol)
 478 {
 479         struct nl_sock *nl_sock;
 480
 481         nl_sock = nl_socket_alloc();
 482         if (!nl_sock)
 483                 goto err;
 484
 485         if (nl_connect(nl_sock, protocol) < 0)
 486                 goto err;
 487
 488         return nl_sock;
 489
 490 err:
 491         if (nl_sock)
 492                 nl_socket_free(nl_sock);
 493
 494         return NULL;
 495 }
 496
 497
 498 struct addr_info {
 499         int ifindex;
 500         int af;
 501         struct odhcpd_ipaddr **addrs;
 502         int pending;
 503         ssize_t ret;
 504 };
 505
 506
 507 static int cb_addr_valid(struct nl_msg *msg, void *arg)
 508 {
 509         struct addr_info *ctxt = (struct addr_info *)arg;
 510         struct odhcpd_ipaddr *addrs = *(ctxt->addrs);
 511         struct nlmsghdr *hdr = nlmsg_hdr(msg);
 512         struct ifaddrmsg *ifa;
 513         struct nlattr *nla[__IFA_MAX], *nla_addr = NULL;
 514
 515         if (hdr->nlmsg_type != RTM_NEWADDR)
 516                 return NL_SKIP;
 517
 518         ifa = NLMSG_DATA(hdr);
 519         if (ifa->ifa_scope != RT_SCOPE_UNIVERSE ||
 520                         (ctxt->af != ifa->ifa_family) ||
 521                         (ctxt->ifindex && ifa->ifa_index != (unsigned)ctxt->ifindex))
 522                 return NL_SKIP;
 523
 524         nlmsg_parse(hdr, sizeof(*ifa), nla, __IFA_MAX - 1, NULL);
 525
 526         switch (ifa->ifa_family) {
 527         case AF_INET6:
 528                 if (nla[IFA_ADDRESS])
 529                         nla_addr = nla[IFA_ADDRESS];
 530                 break;
 531
 532         case AF_INET:
 533                 if (nla[IFA_LOCAL])
 534                         nla_addr = nla[IFA_LOCAL];
 535                 break;
 536
 537         default:
 538                 break;
 539         }
 540         if (!nla_addr)
 541                 return NL_SKIP;
 542
 543         addrs = realloc(addrs, sizeof(*addrs)*(ctxt->ret + 1));
 544         if (!addrs)
 545                 return NL_SKIP;
 546
 547         memset(&addrs[ctxt->ret], 0, sizeof(addrs[ctxt->ret]));
 548         addrs[ctxt->ret].prefix = ifa->ifa_prefixlen;
 549
 550         nla_memcpy(&addrs[ctxt->ret].addr, nla_addr,
 551                         sizeof(addrs[ctxt->ret].addr));
 552
 553         if (nla[IFA_BROADCAST])
 554                 nla_memcpy(&addrs[ctxt->ret].broadcast, nla[IFA_BROADCAST],
 555                                 sizeof(addrs[ctxt->ret].broadcast));
 556
 557         if (nla[IFA_CACHEINFO]) {
 558                 struct ifa_cacheinfo *ifc = nla_data(nla[IFA_CACHEINFO]);
 559
 560                 addrs[ctxt->ret].preferred = ifc->ifa_prefered;
 561                 addrs[ctxt->ret].valid = ifc->ifa_valid;
 562         }
 563
 564         if (ifa->ifa_flags & IFA_F_DEPRECATED)
 565                 addrs[ctxt->ret].preferred = 0;
 566
 567         ctxt->ret++;
 568         *(ctxt->addrs) = addrs;
 569
 570         return NL_OK;
 571 }
 572
 573
 574 static int cb_addr_finish(_unused struct nl_msg *msg, void *arg)
 575 {
 576         struct addr_info *ctxt = (struct addr_info *)arg;
 577
 578         ctxt->pending = 0;
 579
 580         return NL_STOP;
 581 }
 582
 583
 584 static int cb_addr_error(_unused struct sockaddr_nl *nla, struct nlmsgerr *err,
 585                 void *arg)
 586 {
 587         struct addr_info *ctxt = (struct addr_info *)arg;
 588
 589         ctxt->pending = 0;
 590         ctxt->ret = err->error;
 591
 592         return NL_STOP;
 593 }
 594
 595
 596 static int prefix_cmp(const void *va, const void *vb)
 597 {
 598         const struct odhcpd_ipaddr *a = va, *b = vb;
 599         int ret = 0;
 600
 601         if (a->prefix == b->prefix) {
 602                 ret = (ntohl(a->addr.in.s_addr) < ntohl(b->addr.in.s_addr)) ? 1 :
 603                         (ntohl(a->addr.in.s_addr) > ntohl(b->addr.in.s_addr)) ? -1 : 0;
 604         } else
 605                 ret = a->prefix < b->prefix ? 1 : -1;
 606
 607         return ret;
 608 }
 609
 610
 611 /* compare IPv6 prefixes */
 612 static int prefix6_cmp(const void *va, const void *vb)
 613 {
 614         const struct odhcpd_ipaddr *a = va, *b = vb;
 615         uint32_t a_pref = IN6_IS_ADDR_ULA(&a->addr.in6) ? 1 : a->preferred;
 616         uint32_t b_pref = IN6_IS_ADDR_ULA(&b->addr.in6) ? 1 : b->preferred;
 617         return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
 618 }
 619
 620
 621 /* Detect an IPV6-address currently assigned to the given interface */
 622 ssize_t netlink_get_interface_addrs(int ifindex, bool v6, struct odhcpd_ipaddr **addrs)
 623 {
 624         struct nl_msg *msg;
 625         struct ifaddrmsg ifa = {
 626                 .ifa_family = v6? AF_INET6: AF_INET,
 627                 .ifa_prefixlen = 0,
 628                 .ifa_flags = 0,
 629                 .ifa_scope = 0,
 630                 .ifa_index = ifindex, };
 631         struct nl_cb *cb = nl_cb_alloc(NL_CB_DEFAULT);
 632         struct addr_info ctxt = {
 633                 .ifindex = ifindex,
 634                 .af = v6? AF_INET6: AF_INET,
 635                 .addrs = addrs,
 636                 .ret = 0,
 637                 .pending = 1,
 638         };
 639
 640         if (!cb) {
 641                 ctxt.ret = -1;
 642                 goto out;
 643         }
 644
 645         msg = nlmsg_alloc_simple(RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP);
 646
 647         if (!msg) {
 648                 ctxt.ret = - 1;
 649                 goto out;
 650         }
 651
 652         nlmsg_append(msg, &ifa, sizeof(ifa), 0);
 653
 654         nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, cb_addr_valid, &ctxt);
 655         nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, cb_addr_finish, &ctxt);
 656         nl_cb_err(cb, NL_CB_CUSTOM, cb_addr_error, &ctxt);
 657
 658         ctxt.ret = nl_send_auto_complete(rtnl_socket, msg);
 659         if (ctxt.ret < 0)
 660                 goto free;
 661
 662         ctxt.ret = 0;
 663         while (ctxt.pending > 0)
 664                 nl_recvmsgs(rtnl_socket, cb);
 665
 666         if (ctxt.ret <= 0)
 667                 goto free;
 668
 669         time_t now = odhcpd_time();
 670         struct odhcpd_ipaddr *addr = *addrs;
 671
 672         qsort(addr, ctxt.ret, sizeof(*addr), v6 ? prefix6_cmp : prefix_cmp);
 673
 674         for (ssize_t i = 0; i < ctxt.ret; ++i) {
 675                 if (addr[i].preferred < UINT32_MAX - now)
 676                         addr[i].preferred += now;
 677
 678                 if (addr[i].valid < UINT32_MAX - now)
 679                         addr[i].valid += now;
 680         }
 681
 682 free:
 683         nlmsg_free(msg);
 684 out:
 685         nl_cb_put(cb);
 686
 687         return ctxt.ret;
 688 }
 689
 690
 691 struct neigh_info {
 692         int ifindex;
 693         int pending;
 694         const struct in6_addr *addr;
 695         int ret;
 696 };
 697
 698
 699 static int cb_proxy_neigh_valid(struct nl_msg *msg, void *arg)
 700 {
 701         struct neigh_info *ctxt = (struct neigh_info *)arg;
 702         struct nlmsghdr *hdr = nlmsg_hdr(msg);
 703         struct ndmsg *ndm;
 704         struct nlattr *nla_dst;
 705
 706         if (hdr->nlmsg_type != RTM_NEWNEIGH)
 707                 return NL_SKIP;
 708
 709         ndm = NLMSG_DATA(hdr);
 710         if (ndm->ndm_family != AF_INET6 ||
 711                         (ctxt->ifindex && ndm->ndm_ifindex != ctxt->ifindex))
 712                 return NL_SKIP;
 713
 714         if (!(ndm->ndm_flags & NTF_PROXY))
 715                 return NL_SKIP;
 716
 717         nla_dst = nlmsg_find_attr(hdr, sizeof(*ndm), NDA_DST);
 718         if (!nla_dst)
 719                 return NL_SKIP;
 720
 721         if (nla_memcmp(nla_dst,ctxt->addr, 16) == 0)
 722                 ctxt->ret = 1;
 723
 724         return NL_OK;
 725 }
 726
 727
 728 static int cb_proxy_neigh_finish(_unused struct nl_msg *msg, void *arg)
 729 {
 730         struct neigh_info *ctxt = (struct neigh_info *)arg;
 731
 732         ctxt->pending = 0;
 733
 734         return NL_STOP;
 735 }
 736
 737
 738 static int cb_proxy_neigh_error(_unused struct sockaddr_nl *nla, struct nlmsgerr *err,
 739                 void *arg)
 740 {
 741         struct neigh_info *ctxt = (struct neigh_info *)arg;
 742
 743         ctxt->pending = 0;
 744         ctxt->ret = err->error;
 745
 746         return NL_STOP;
 747 }
 748
 749 /* Detect an IPV6-address proxy neighbor for the given interface */
 750 int netlink_get_interface_proxy_neigh(int ifindex, const struct in6_addr *addr)
 751 {
 752         struct nl_msg *msg;
 753         struct ndmsg ndm = {
 754                 .ndm_family = AF_INET6,
 755                 .ndm_flags = NTF_PROXY,
 756                 .ndm_ifindex = ifindex,
 757         };
 758         struct nl_cb *cb = nl_cb_alloc(NL_CB_DEFAULT);
 759         struct neigh_info ctxt = {
 760                 .ifindex = ifindex,
 761                 .addr = addr,
 762                 .ret = 0,
 763                 .pending = 1,
 764         };
 765
 766         if (!cb) {
 767                 ctxt.ret = -1;
 768                 goto out;
 769         }
 770
 771         msg = nlmsg_alloc_simple(RTM_GETNEIGH, NLM_F_REQUEST | NLM_F_MATCH);
 772
 773         if (!msg) {
 774                 ctxt.ret = -1;
 775                 goto out;
 776         }
 777
 778         nlmsg_append(msg, &ndm, sizeof(ndm), 0);
 779         nla_put(msg, NDA_DST, sizeof(*addr), addr);
 780
 781         nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, cb_proxy_neigh_valid, &ctxt);
 782         nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, cb_proxy_neigh_finish, &ctxt);
 783         nl_cb_err(cb, NL_CB_CUSTOM, cb_proxy_neigh_error, &ctxt);
 784
 785         ctxt.ret = nl_send_auto_complete(rtnl_socket, msg);
 786         if (ctxt.ret < 0)
 787                 goto free;
 788
 789         while (ctxt.pending > 0)
 790                 nl_recvmsgs(rtnl_socket, cb);
 791
 792 free:
 793         nlmsg_free(msg);
 794 out:
 795         nl_cb_put(cb);
 796
 797         return ctxt.ret;
 798 }
 799
 800
 801 int netlink_setup_route(const struct in6_addr *addr, const int prefixlen,
 802                 const int ifindex, const struct in6_addr *gw,
 803                 const uint32_t metric, const bool add)
 804 {
 805         struct nl_msg *msg;
 806         struct rtmsg rtm = {
 807                 .rtm_family = AF_INET6,
 808                 .rtm_dst_len = prefixlen,
 809                 .rtm_src_len = 0,
 810                 .rtm_table = RT_TABLE_MAIN,
 811                 .rtm_protocol = (add ? RTPROT_STATIC : RTPROT_UNSPEC),
 812                 .rtm_scope = (add ? (gw ? RT_SCOPE_UNIVERSE : RT_SCOPE_LINK) : RT_SCOPE_NOWHERE),
 813                 .rtm_type = (add ? RTN_UNICAST : RTN_UNSPEC),
 814         };
 815         int ret = 0;
 816
 817         msg = nlmsg_alloc_simple(add ? RTM_NEWROUTE : RTM_DELROUTE,
 818                                         add ? NLM_F_CREATE | NLM_F_REPLACE : 0);
 819         if (!msg)
 820                 return -1;
 821
 822         nlmsg_append(msg, &rtm, sizeof(rtm), 0);
 823
 824         nla_put(msg, RTA_DST, sizeof(*addr), addr);
 825         nla_put_u32(msg, RTA_OIF, ifindex);
 826         nla_put_u32(msg, RTA_PRIORITY, metric);
 827
 828         if (gw)
 829                 nla_put(msg, RTA_GATEWAY, sizeof(*gw), gw);
 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
 841 int netlink_setup_proxy_neigh(const struct in6_addr *addr,
 842                 const int ifindex, const bool add)
 843 {
 844         struct nl_msg *msg;
 845         struct ndmsg ndm = {
 846                 .ndm_family = AF_INET6,
 847                 .ndm_flags = NTF_PROXY,
 848                 .ndm_ifindex = ifindex,
 849         };
 850         int ret = 0, flags = NLM_F_REQUEST;
 851
 852         if (add)
 853                 flags |= NLM_F_REPLACE | NLM_F_CREATE;
 854
 855         msg = nlmsg_alloc_simple(add ? RTM_NEWNEIGH : RTM_DELNEIGH, flags);
 856         if (!msg)
 857                 return -1;
 858
 859         nlmsg_append(msg, &ndm, sizeof(ndm), 0);
 860
 861         nla_put(msg, NDA_DST, sizeof(*addr), addr);
 862
 863         ret = nl_send_auto_complete(rtnl_socket, msg);
 864         nlmsg_free(msg);
 865
 866         if (ret < 0)
 867                 return ret;
 868
 869         return nl_wait_for_ack(rtnl_socket);
 870 }
 871
 872
 873 int netlink_setup_addr(struct odhcpd_ipaddr *addr,
 874                 const int ifindex, const bool v6, const bool add)
 875 {
 876         struct nl_msg *msg;
 877         struct ifaddrmsg ifa = {
 878                 .ifa_family = v6 ? AF_INET6 : AF_INET,
 879                 .ifa_prefixlen = addr->prefix,
 880                 .ifa_flags = 0,
 881                 .ifa_scope = 0,
 882                 .ifa_index = ifindex, };
 883         int ret = 0, flags = NLM_F_REQUEST;
 884
 885         if (add)
 886                 flags |= NLM_F_REPLACE | NLM_F_CREATE;
 887
 888         msg = nlmsg_alloc_simple(add ? RTM_NEWADDR : RTM_DELADDR, 0);
 889         if (!msg)
 890                 return -1;
 891
 892         nlmsg_append(msg, &ifa, sizeof(ifa), flags);
 893         nla_put(msg, IFA_LOCAL, v6 ? 16 : 4, &addr->addr);
 894         if (v6) {
 895                 struct ifa_cacheinfo cinfo = {  .ifa_prefered = 0xffffffffU,
 896                                                 .ifa_valid = 0xffffffffU,
 897                                                 .cstamp = 0,
 898                                                 .tstamp = 0 };
 899                 time_t now = odhcpd_time();
 900
 901                 if (addr->preferred) {
 902                         int64_t preferred = addr->preferred - now;
 903                         if (preferred < 0)
 904                                 preferred = 0;
 905                         else if (preferred > UINT32_MAX)
 906                                 preferred = UINT32_MAX;
 907
 908                         cinfo.ifa_prefered = preferred;
 909                 }
 910
 911                 if (addr->valid) {
 912                         int64_t valid = addr->valid - now;
 913                         if (valid <= 0) {
 914                                 nlmsg_free(msg);
 915                                 return -1;
 916                         }
 917                         else if (valid > UINT32_MAX)
 918                                 valid = UINT32_MAX;
 919
 920                         cinfo.ifa_valid = valid;
 921                 }
 922
 923                 nla_put(msg, IFA_CACHEINFO, sizeof(cinfo), &cinfo);
 924
 925                 nla_put_u32(msg, IFA_FLAGS, IFA_F_NOPREFIXROUTE);
 926         } else {
 927                 if (addr->broadcast.s_addr)
 928                         nla_put_u32(msg, IFA_BROADCAST, addr->broadcast.s_addr);
 929         }
 930
 931         ret = nl_send_auto_complete(rtnl_socket, msg);
 932         nlmsg_free(msg);
 933
 934         if (ret < 0)
 935                 return ret;
 936
 937         return nl_wait_for_ack(rtnl_socket);
 938 }
 939
 940 void netlink_dump_neigh_table(const bool proxy)
 941 {
 942         struct nl_msg *msg;
 943         struct ndmsg ndm = {
 944                 .ndm_family = AF_INET6,
 945                 .ndm_flags = proxy ? NTF_PROXY : 0,
 946         };
 947
 948         msg = nlmsg_alloc_simple(RTM_GETNEIGH, NLM_F_REQUEST | NLM_F_DUMP);
 949         if (!msg)
 950                 return;
 951
 952         nlmsg_append(msg, &ndm, sizeof(ndm), 0);
 953
 954         nl_send_auto_complete(rtnl_event.sock, msg);
 955
 956         nlmsg_free(msg);
 957 }
 958
 959 void netlink_dump_addr_table(const bool v6)
 960 {
 961         struct nl_msg *msg;
 962         struct ifaddrmsg ifa = {
 963                 .ifa_family = v6 ? AF_INET6 : AF_INET,
 964         };
 965
 966         msg = nlmsg_alloc_simple(RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP);
 967         if (!msg)
 968                 return;
 969
 970         nlmsg_append(msg, &ifa, sizeof(ifa), 0);
 971
 972         nl_send_auto_complete(rtnl_event.sock, msg);
 973
 974         nlmsg_free(msg);
 975 }