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.neigh.state = ndm->ndm_state;
 420                 event_info.neigh.flags = ndm->ndm_flags;
 421
 422                 call_netevent_handler_list(add ? NETEV_NEIGH6_ADD : NETEV_NEIGH6_DEL,
 423                                                 &event_info);
 424         }
 425
 426         return NL_OK;
 427 }
 428
 429 /* Handler for neighbor cache entries from the kernel. This is our source
 430  * to learn and unlearn hosts on interfaces. */
 431 static int cb_rtnl_valid(struct nl_msg *msg, _unused void *arg)
 432 {
 433         struct nlmsghdr *hdr = nlmsg_hdr(msg);
 434         int ret = NL_SKIP;
 435         bool add = false;
 436
 437         switch (hdr->nlmsg_type) {
 438         case RTM_NEWLINK:
 439                 ret = handle_rtm_link(hdr);
 440                 break;
 441
 442         case RTM_NEWROUTE:
 443                 add = true;
 444                 /* fall through */
 445         case RTM_DELROUTE:
 446                 ret = handle_rtm_route(hdr, add);
 447                 break;
 448
 449         case RTM_NEWADDR:
 450                 add = true;
 451                 /* fall through */
 452         case RTM_DELADDR:
 453                 ret = handle_rtm_addr(hdr, add);
 454                 break;
 455
 456         case RTM_NEWNEIGH:
 457                 add = true;
 458                 /* fall through */
 459         case RTM_DELNEIGH:
 460                 ret = handle_rtm_neigh(hdr, add);
 461                 break;
 462
 463         default:
 464                 break;
 465         }
 466
 467         return ret;
 468 }
 469
 470 static void catch_rtnl_err(struct odhcpd_event *e, int error)
 471 {
 472         struct event_socket *ev_sock = container_of(e, struct event_socket, ev);
 473
 474         if (error != ENOBUFS)
 475                 goto err;
 476
 477         /* Double netlink event buffer size */
 478         ev_sock->sock_bufsize *= 2;
 479
 480         if (nl_socket_set_buffer_size(ev_sock->sock, ev_sock->sock_bufsize, 0))
 481                 goto err;
 482
 483         netlink_dump_addr_table(true);
 484         return;
 485
 486 err:
 487         odhcpd_deregister(e);
 488 }
 489
 490 static struct nl_sock *create_socket(int protocol)
 491 {
 492         struct nl_sock *nl_sock;
 493
 494         nl_sock = nl_socket_alloc();
 495         if (!nl_sock)
 496                 goto err;
 497
 498         if (nl_connect(nl_sock, protocol) < 0)
 499                 goto err;
 500
 501         return nl_sock;
 502
 503 err:
 504         if (nl_sock)
 505                 nl_socket_free(nl_sock);
 506
 507         return NULL;
 508 }
 509
 510
 511 struct addr_info {
 512         int ifindex;
 513         int af;
 514         struct odhcpd_ipaddr **addrs;
 515         int pending;
 516         ssize_t ret;
 517 };
 518
 519
 520 static int cb_valid_handler(struct nl_msg *msg, void *arg)
 521 {
 522         struct addr_info *ctxt = (struct addr_info *)arg;
 523         struct odhcpd_ipaddr *addrs = *(ctxt->addrs);
 524         struct nlmsghdr *hdr = nlmsg_hdr(msg);
 525         struct ifaddrmsg *ifa;
 526         struct nlattr *nla[__IFA_MAX], *nla_addr = NULL;
 527
 528         if (hdr->nlmsg_type != RTM_NEWADDR)
 529                 return NL_SKIP;
 530
 531         ifa = NLMSG_DATA(hdr);
 532         if (ifa->ifa_scope != RT_SCOPE_UNIVERSE ||
 533                         (ctxt->af != ifa->ifa_family) ||
 534                         (ctxt->ifindex && ifa->ifa_index != (unsigned)ctxt->ifindex))
 535                 return NL_SKIP;
 536
 537         nlmsg_parse(hdr, sizeof(*ifa), nla, __IFA_MAX - 1, NULL);
 538
 539         switch (ifa->ifa_family) {
 540         case AF_INET6:
 541                 if (nla[IFA_ADDRESS])
 542                         nla_addr = nla[IFA_ADDRESS];
 543                 break;
 544
 545         case AF_INET:
 546                 if (nla[IFA_LOCAL])
 547                         nla_addr = nla[IFA_LOCAL];
 548                 break;
 549
 550         default:
 551                 break;
 552         }
 553         if (!nla_addr)
 554                 return NL_SKIP;
 555
 556         addrs = realloc(addrs, sizeof(*addrs)*(ctxt->ret + 1));
 557         if (!addrs)
 558                 return NL_SKIP;
 559
 560         memset(&addrs[ctxt->ret], 0, sizeof(addrs[ctxt->ret]));
 561         addrs[ctxt->ret].prefix = ifa->ifa_prefixlen;
 562
 563         nla_memcpy(&addrs[ctxt->ret].addr, nla_addr,
 564                         sizeof(addrs[ctxt->ret].addr));
 565
 566         if (nla[IFA_BROADCAST])
 567                 nla_memcpy(&addrs[ctxt->ret].broadcast, nla[IFA_BROADCAST],
 568                                 sizeof(addrs[ctxt->ret].broadcast));
 569
 570         if (nla[IFA_CACHEINFO]) {
 571                 struct ifa_cacheinfo *ifc = nla_data(nla[IFA_CACHEINFO]);
 572
 573                 addrs[ctxt->ret].preferred = ifc->ifa_prefered;
 574                 addrs[ctxt->ret].valid = ifc->ifa_valid;
 575         }
 576
 577         if (ifa->ifa_flags & IFA_F_DEPRECATED)
 578                 addrs[ctxt->ret].preferred = 0;
 579
 580         ctxt->ret++;
 581         *(ctxt->addrs) = addrs;
 582
 583         return NL_OK;
 584 }
 585
 586
 587 static int cb_finish_handler(_unused struct nl_msg *msg, void *arg)
 588 {
 589         struct addr_info *ctxt = (struct addr_info *)arg;
 590
 591         ctxt->pending = 0;
 592
 593         return NL_STOP;
 594 }
 595
 596
 597 static int cb_error_handler(_unused struct sockaddr_nl *nla, struct nlmsgerr *err,
 598                 void *arg)
 599 {
 600         struct addr_info *ctxt = (struct addr_info *)arg;
 601
 602         ctxt->pending = 0;
 603         ctxt->ret = err->error;
 604
 605         return NL_STOP;
 606 }
 607
 608
 609 static int prefix_cmp(const void *va, const void *vb)
 610 {
 611         const struct odhcpd_ipaddr *a = va, *b = vb;
 612         int ret = 0;
 613
 614         if (a->prefix == b->prefix) {
 615                 ret = (ntohl(a->addr.in.s_addr) < ntohl(b->addr.in.s_addr)) ? 1 :
 616                         (ntohl(a->addr.in.s_addr) > ntohl(b->addr.in.s_addr)) ? -1 : 0;
 617         } else
 618                 ret = a->prefix < b->prefix ? 1 : -1;
 619
 620         return ret;
 621 }
 622
 623
 624 /* compare IPv6 prefixes */
 625 static int prefix6_cmp(const void *va, const void *vb)
 626 {
 627         const struct odhcpd_ipaddr *a = va, *b = vb;
 628         uint32_t a_pref = IN6_IS_ADDR_ULA(&a->addr.in6) ? 1 : a->preferred;
 629         uint32_t b_pref = IN6_IS_ADDR_ULA(&b->addr.in6) ? 1 : b->preferred;
 630         return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
 631 }
 632
 633
 634 /* Detect an IPV6-address currently assigned to the given interface */
 635 ssize_t netlink_get_interface_addrs(int ifindex, bool v6, struct odhcpd_ipaddr **addrs)
 636 {
 637         struct nl_msg *msg;
 638         struct ifaddrmsg ifa = {
 639                 .ifa_family = v6? AF_INET6: AF_INET,
 640                 .ifa_prefixlen = 0,
 641                 .ifa_flags = 0,
 642                 .ifa_scope = 0,
 643                 .ifa_index = ifindex, };
 644         struct nl_cb *cb = nl_cb_alloc(NL_CB_DEFAULT);
 645         struct addr_info ctxt = {
 646                 .ifindex = ifindex,
 647                 .af = v6? AF_INET6: AF_INET,
 648                 .addrs = addrs,
 649                 .ret = 0,
 650                 .pending = 1,
 651         };
 652
 653         if (!cb) {
 654                 ctxt.ret = -1;
 655                 goto out;
 656         }
 657
 658         msg = nlmsg_alloc_simple(RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP);
 659
 660         if (!msg) {
 661                 ctxt.ret = - 1;
 662                 goto out;
 663         }
 664
 665         nlmsg_append(msg, &ifa, sizeof(ifa), 0);
 666
 667         nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, cb_valid_handler, &ctxt);
 668         nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, cb_finish_handler, &ctxt);
 669         nl_cb_err(cb, NL_CB_CUSTOM, cb_error_handler, &ctxt);
 670
 671         nl_send_auto_complete(rtnl_socket, msg);
 672         while (ctxt.pending > 0)
 673                 nl_recvmsgs(rtnl_socket, cb);
 674
 675         nlmsg_free(msg);
 676
 677         if (ctxt.ret <= 0)
 678                 goto out;
 679
 680         time_t now = odhcpd_time();
 681         struct odhcpd_ipaddr *addr = *addrs;
 682
 683         qsort(addr, ctxt.ret, sizeof(*addr), v6 ? prefix6_cmp : prefix_cmp);
 684
 685         for (ssize_t i = 0; i < ctxt.ret; ++i) {
 686                 if (addr[i].preferred < UINT32_MAX - now)
 687                         addr[i].preferred += now;
 688
 689                 if (addr[i].valid < UINT32_MAX - now)
 690                         addr[i].valid += now;
 691         }
 692
 693 out:
 694         nl_cb_put(cb);
 695
 696         return ctxt.ret;
 697 }
 698
 699
 700 int netlink_setup_route(const struct in6_addr *addr, const int prefixlen,
 701                 const int ifindex, const struct in6_addr *gw,
 702                 const uint32_t metric, const bool add)
 703 {
 704         struct nl_msg *msg;
 705         struct rtmsg rtm = {
 706                 .rtm_family = AF_INET6,
 707                 .rtm_dst_len = prefixlen,
 708                 .rtm_src_len = 0,
 709                 .rtm_table = RT_TABLE_MAIN,
 710                 .rtm_protocol = (add ? RTPROT_STATIC : RTPROT_UNSPEC),
 711                 .rtm_scope = (add ? (gw ? RT_SCOPE_UNIVERSE : RT_SCOPE_LINK) : RT_SCOPE_NOWHERE),
 712                 .rtm_type = (add ? RTN_UNICAST : RTN_UNSPEC),
 713         };
 714         int ret = 0;
 715
 716         msg = nlmsg_alloc_simple(add ? RTM_NEWROUTE : RTM_DELROUTE,
 717                                         add ? NLM_F_CREATE | NLM_F_REPLACE : 0);
 718         if (!msg)
 719                 return -1;
 720
 721         nlmsg_append(msg, &rtm, sizeof(rtm), 0);
 722
 723         nla_put(msg, RTA_DST, sizeof(*addr), addr);
 724         nla_put_u32(msg, RTA_OIF, ifindex);
 725         nla_put_u32(msg, RTA_PRIORITY, metric);
 726
 727         if (gw)
 728                 nla_put(msg, RTA_GATEWAY, sizeof(*gw), gw);
 729
 730         ret = nl_send_auto_complete(rtnl_socket, msg);
 731         nlmsg_free(msg);
 732
 733         if (ret < 0)
 734                 return ret;
 735
 736         return nl_wait_for_ack(rtnl_socket);
 737 }
 738
 739
 740 int netlink_setup_proxy_neigh(const struct in6_addr *addr,
 741                 const int ifindex, const bool add)
 742 {
 743         struct nl_msg *msg;
 744         struct ndmsg ndm = {
 745                 .ndm_family = AF_INET6,
 746                 .ndm_flags = NTF_PROXY,
 747                 .ndm_ifindex = ifindex,
 748         };
 749         int ret = 0, flags = NLM_F_REQUEST;
 750
 751         if (add)
 752                 flags |= NLM_F_REPLACE | NLM_F_CREATE;
 753
 754         msg = nlmsg_alloc_simple(add ? RTM_NEWNEIGH : RTM_DELNEIGH, flags);
 755         if (!msg)
 756                 return -1;
 757
 758         nlmsg_append(msg, &ndm, sizeof(ndm), 0);
 759
 760         nla_put(msg, NDA_DST, sizeof(*addr), addr);
 761
 762         ret = nl_send_auto_complete(rtnl_socket, msg);
 763         nlmsg_free(msg);
 764
 765         if (ret < 0)
 766                 return ret;
 767
 768         return nl_wait_for_ack(rtnl_socket);
 769 }
 770
 771
 772 int netlink_setup_addr(struct odhcpd_ipaddr *addr,
 773                 const int ifindex, const bool v6, const bool add)
 774 {
 775         struct nl_msg *msg;
 776         struct ifaddrmsg ifa = {
 777                 .ifa_family = v6 ? AF_INET6 : AF_INET,
 778                 .ifa_prefixlen = addr->prefix,
 779                 .ifa_flags = 0,
 780                 .ifa_scope = 0,
 781                 .ifa_index = ifindex, };
 782         int ret = 0, flags = NLM_F_REQUEST;
 783
 784         if (add)
 785                 flags |= NLM_F_REPLACE | NLM_F_CREATE;
 786
 787         msg = nlmsg_alloc_simple(add ? RTM_NEWADDR : RTM_DELADDR, 0);
 788         if (!msg)
 789                 return -1;
 790
 791         nlmsg_append(msg, &ifa, sizeof(ifa), flags);
 792         nla_put(msg, IFA_LOCAL, v6 ? 16 : 4, &addr->addr);
 793         if (v6) {
 794                 struct ifa_cacheinfo cinfo = {  .ifa_prefered = 0xffffffffU,
 795                                                 .ifa_valid = 0xffffffffU,
 796                                                 .cstamp = 0,
 797                                                 .tstamp = 0 };
 798                 time_t now = odhcpd_time();
 799
 800                 if (addr->preferred) {
 801                         int64_t preferred = addr->preferred - now;
 802                         if (preferred < 0)
 803                                 preferred = 0;
 804                         else if (preferred > UINT32_MAX)
 805                                 preferred = UINT32_MAX;
 806
 807                         cinfo.ifa_prefered = preferred;
 808                 }
 809
 810                 if (addr->valid) {
 811                         int64_t valid = addr->valid - now;
 812                         if (valid <= 0) {
 813                                 nlmsg_free(msg);
 814                                 return -1;
 815                         }
 816                         else if (valid > UINT32_MAX)
 817                                 valid = UINT32_MAX;
 818
 819                         cinfo.ifa_valid = valid;
 820                 }
 821
 822                 nla_put(msg, IFA_CACHEINFO, sizeof(cinfo), &cinfo);
 823
 824                 nla_put_u32(msg, IFA_FLAGS, IFA_F_NOPREFIXROUTE);
 825         } else {
 826                 if (addr->broadcast.s_addr)
 827                         nla_put_u32(msg, IFA_BROADCAST, addr->broadcast.s_addr);
 828         }
 829
 830         ret = nl_send_auto_complete(rtnl_socket, msg);
 831         nlmsg_free(msg);
 832
 833         if (ret < 0)
 834                 return ret;
 835
 836         return nl_wait_for_ack(rtnl_socket);
 837 }
 838
 839 void netlink_dump_neigh_table(const bool proxy)
 840 {
 841         struct nl_msg *msg;
 842         struct ndmsg ndm = {
 843                 .ndm_family = AF_INET6,
 844                 .ndm_flags = proxy ? NTF_PROXY : 0,
 845         };
 846
 847         msg = nlmsg_alloc_simple(RTM_GETNEIGH, NLM_F_REQUEST | NLM_F_DUMP);
 848         if (!msg)
 849                 return;
 850
 851         nlmsg_append(msg, &ndm, sizeof(ndm), 0);
 852
 853         nl_send_auto_complete(rtnl_event.sock, msg);
 854
 855         nlmsg_free(msg);
 856 }
 857
 858 void netlink_dump_addr_table(const bool v6)
 859 {
 860         struct nl_msg *msg;
 861         struct ifaddrmsg ifa = {
 862                 .ifa_family = v6 ? AF_INET6 : AF_INET,
 863         };
 864
 865         msg = nlmsg_alloc_simple(RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP);
 866         if (!msg)
 867                 return;
 868
 869         nlmsg_append(msg, &ifa, sizeof(ifa), 0);
 870
 871         nl_send_auto_complete(rtnl_event.sock, msg);
 872
 873         nlmsg_free(msg);
 874 }