src/odhcpd.c

   1 /**
   2  * Copyright (C) 2012-2013 Steven Barth <steven@midlink.org>
   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 <time.h>
  16 #include <errno.h>
  17 #include <fcntl.h>
  18 #include <stdio.h>
  19 #include <resolv.h>
  20 #include <getopt.h>
  21 #include <stddef.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <unistd.h>
  25 #include <signal.h>
  26 #include <stdbool.h>
  27 #include <syslog.h>
  28 #include <alloca.h>
  29
  30 #include <arpa/inet.h>
  31 #include <net/if.h>
  32 #include <netinet/ip6.h>
  33 #include <netpacket/packet.h>
  34 #include <linux/netlink.h>
  35 #include <linux/if_addr.h>
  36 #include <linux/neighbour.h>
  37 #include <linux/rtnetlink.h>
  38
  39 #include <sys/socket.h>
  40 #include <sys/ioctl.h>
  41 #include <sys/epoll.h>
  42 #include <sys/types.h>
  43 #include <sys/wait.h>
  44 #include <sys/syscall.h>
  45
  46 #include <netlink/msg.h>
  47 #include <netlink/socket.h>
  48 #include <netlink/attr.h>
  49 #include <libubox/uloop.h>
  50 #include "odhcpd.h"
  51
  52
  53
  54 static int ioctl_sock;
  55 static struct nl_sock *rtnl_socket = NULL;
  56 static int urandom_fd = -1;
  57
  58 static void sighandler(_unused int signal)
  59 {
  60         uloop_end();
  61 }
  62
  63 static void print_usage(const char *app)
  64 {
  65         printf(
  66         "== %s Usage ==\n\n"
  67         "  -h, --help   Print this help\n"
  68         "  -l level     Specify log level 0..7 (default %d)\n",
  69                 app, config.log_level
  70         );
  71 }
  72
  73 int main(int argc, char **argv)
  74 {
  75         openlog("odhcpd", LOG_PERROR | LOG_PID, LOG_DAEMON);
  76         int opt;
  77
  78         while ((opt = getopt(argc, argv, "hl:")) != -1) {
  79                 switch (opt) {
  80                 case 'h':
  81                         print_usage(argv[0]);
  82                         return 0;
  83                 case 'l':
  84                         config.log_level = (atoi(optarg) & LOG_PRIMASK);
  85                         fprintf(stderr, "Log level set to %d\n", config.log_level);
  86                         break;
  87                 }
  88         }
  89         setlogmask(LOG_UPTO(config.log_level));
  90         uloop_init();
  91
  92         if (getuid() != 0) {
  93                 syslog(LOG_ERR, "Must be run as root!");
  94                 return 2;
  95         }
  96
  97         ioctl_sock = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
  98
  99         if (!(rtnl_socket = odhcpd_create_nl_socket(NETLINK_ROUTE))) {
 100                 syslog(LOG_ERR, "Unable to open nl socket: %s", strerror(errno));
 101                 return 2;
 102         }
 103
 104         if ((urandom_fd = open("/dev/urandom", O_RDONLY | O_CLOEXEC)) < 0)
 105                 return 4;
 106
 107         signal(SIGUSR1, SIG_IGN);
 108         signal(SIGINT, sighandler);
 109         signal(SIGTERM, sighandler);
 110
 111         if (init_router())
 112                 return 4;
 113
 114         if (init_dhcpv6())
 115                 return 4;
 116
 117         if (init_ndp())
 118                 return 4;
 119
 120         if (init_dhcpv4())
 121                 return 4;
 122
 123         odhcpd_run();
 124         return 0;
 125 }
 126
 127 struct nl_sock *odhcpd_create_nl_socket(int protocol)
 128 {
 129         struct nl_sock *nl_sock;
 130
 131         nl_sock = nl_socket_alloc();
 132         if (!nl_sock)
 133                 goto err;
 134
 135         if (nl_connect(nl_sock, protocol) < 0)
 136                 goto err;
 137
 138         return nl_sock;
 139
 140 err:
 141         if (nl_sock)
 142                 nl_socket_free(nl_sock);
 143
 144         return NULL;
 145 }
 146
 147
 148 // Read IPv6 MTU for interface
 149 int odhcpd_get_interface_config(const char *ifname, const char *what)
 150 {
 151         char buf[64];
 152         const char *sysctl_pattern = "/proc/sys/net/ipv6/conf/%s/%s";
 153         snprintf(buf, sizeof(buf), sysctl_pattern, ifname, what);
 154
 155         int fd = open(buf, O_RDONLY);
 156         ssize_t len = read(fd, buf, sizeof(buf) - 1);
 157         close(fd);
 158
 159         if (len < 0)
 160                 return -1;
 161
 162         buf[len] = 0;
 163         return atoi(buf);
 164 }
 165
 166
 167 // Read IPv6 MAC for interface
 168 int odhcpd_get_mac(const struct interface *iface, uint8_t mac[6])
 169 {
 170         struct ifreq ifr;
 171         memset(&ifr, 0, sizeof(ifr));
 172         strncpy(ifr.ifr_name, iface->ifname, sizeof(ifr.ifr_name));
 173         if (ioctl(ioctl_sock, SIOCGIFHWADDR, &ifr) < 0)
 174                 return -1;
 175         memcpy(mac, ifr.ifr_hwaddr.sa_data, 6);
 176         return 0;
 177 }
 178
 179
 180 // Forwards a packet on a specific interface
 181 ssize_t odhcpd_send(int socket, struct sockaddr_in6 *dest,
 182                 struct iovec *iov, size_t iov_len,
 183                 const struct interface *iface)
 184 {
 185         // Construct headers
 186         uint8_t cmsg_buf[CMSG_SPACE(sizeof(struct in6_pktinfo))] = {0};
 187         struct msghdr msg = {
 188                 .msg_name = (void *) dest,
 189                 .msg_namelen = sizeof(*dest),
 190                 .msg_iov = iov,
 191                 .msg_iovlen = iov_len,
 192                 .msg_control = cmsg_buf,
 193                 .msg_controllen = sizeof(cmsg_buf),
 194                 .msg_flags = 0
 195         };
 196
 197         // Set control data (define destination interface)
 198         struct cmsghdr *chdr = CMSG_FIRSTHDR(&msg);
 199         chdr->cmsg_level = IPPROTO_IPV6;
 200         chdr->cmsg_type = IPV6_PKTINFO;
 201         chdr->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
 202         struct in6_pktinfo *pktinfo = (struct in6_pktinfo*)CMSG_DATA(chdr);
 203         pktinfo->ipi6_ifindex = iface->ifindex;
 204
 205         // Also set scope ID if link-local
 206         if (IN6_IS_ADDR_LINKLOCAL(&dest->sin6_addr)
 207                         || IN6_IS_ADDR_MC_LINKLOCAL(&dest->sin6_addr))
 208                 dest->sin6_scope_id = iface->ifindex;
 209
 210         char ipbuf[INET6_ADDRSTRLEN];
 211         inet_ntop(AF_INET6, &dest->sin6_addr, ipbuf, sizeof(ipbuf));
 212
 213         ssize_t sent = sendmsg(socket, &msg, MSG_DONTWAIT);
 214         if (sent < 0)
 215                 syslog(LOG_NOTICE, "Failed to send to %s%%%s (%s)",
 216                                 ipbuf, iface->ifname, strerror(errno));
 217         else
 218                 syslog(LOG_DEBUG, "Sent %li bytes to %s%%%s",
 219                                 (long)sent, ipbuf, iface->ifname);
 220         return sent;
 221 }
 222
 223 struct addr_info {
 224         int ifindex;
 225         int af;
 226         struct odhcpd_ipaddr **addrs;
 227         int pending;
 228         ssize_t ret;
 229 };
 230
 231 static int cb_valid_handler(struct nl_msg *msg, void *arg)
 232 {
 233         struct addr_info *ctxt = (struct addr_info *)arg;
 234         struct odhcpd_ipaddr *addrs = *(ctxt->addrs);
 235         struct nlmsghdr *hdr = nlmsg_hdr(msg);
 236         struct ifaddrmsg *ifa;
 237         struct nlattr *nla[__IFA_MAX];
 238
 239         if (hdr->nlmsg_type != RTM_NEWADDR)
 240                 return NL_SKIP;
 241
 242         ifa = NLMSG_DATA(hdr);
 243         if (ifa->ifa_scope != RT_SCOPE_UNIVERSE ||
 244                         (ctxt->af != ifa->ifa_family) ||
 245                         (ctxt->ifindex && ifa->ifa_index != (unsigned)ctxt->ifindex))
 246                 return NL_SKIP;
 247
 248         nlmsg_parse(hdr, sizeof(*ifa), nla, __IFA_MAX - 1, NULL);
 249         if (!nla[IFA_ADDRESS])
 250                 return NL_SKIP;
 251
 252         addrs = realloc(addrs, sizeof(*addrs)*(ctxt->ret + 1));
 253         if (!addrs)
 254                 return NL_SKIP;
 255
 256         memset(&addrs[ctxt->ret], 0, sizeof(addrs[ctxt->ret]));
 257         addrs[ctxt->ret].prefix = ifa->ifa_prefixlen;
 258
 259         nla_memcpy(&addrs[ctxt->ret].addr, nla[IFA_ADDRESS],
 260                         sizeof(addrs[ctxt->ret].addr));
 261
 262         if (nla[IFA_CACHEINFO]) {
 263                 struct ifa_cacheinfo *ifc = nla_data(nla[IFA_CACHEINFO]);
 264
 265                 addrs[ctxt->ret].preferred = ifc->ifa_prefered;
 266                 addrs[ctxt->ret].valid = ifc->ifa_valid;
 267         }
 268
 269         if (ifa->ifa_flags & IFA_F_DEPRECATED)
 270                 addrs[ctxt->ret].preferred = 0;
 271
 272         ctxt->ret++;
 273         *(ctxt->addrs) = addrs;
 274
 275         return NL_OK;
 276 }
 277
 278 static int cb_finish_handler(_unused struct nl_msg *msg, void *arg)
 279 {
 280         struct addr_info *ctxt = (struct addr_info *)arg;
 281
 282         ctxt->pending = 0;
 283
 284         return NL_STOP;
 285 }
 286
 287 static int cb_error_handler(_unused struct sockaddr_nl *nla, struct nlmsgerr *err,
 288                 void *arg)
 289 {
 290         struct addr_info *ctxt = (struct addr_info *)arg;
 291
 292         ctxt->pending = 0;
 293         ctxt->ret = err->error;
 294
 295         return NL_STOP;
 296 }
 297
 298 // compare prefixes
 299 static int prefixcmp(const void *va, const void *vb)
 300 {
 301         const struct odhcpd_ipaddr *a = va, *b = vb;
 302         uint32_t a_pref = IN6_IS_ADDR_ULA(&a->addr.in6) ? 1 : a->preferred;
 303         uint32_t b_pref = IN6_IS_ADDR_ULA(&b->addr.in6) ? 1 : b->preferred;
 304         return (a_pref < b_pref) ? 1 : (a_pref > b_pref) ? -1 : 0;
 305 }
 306
 307 // Detect an IPV6-address currently assigned to the given interface
 308 ssize_t odhcpd_get_interface_addresses(int ifindex, bool v6, struct odhcpd_ipaddr **addrs)
 309 {
 310         struct nl_msg *msg;
 311         struct ifaddrmsg ifa = {
 312                 .ifa_family = v6? AF_INET6: AF_INET,
 313                 .ifa_prefixlen = 0,
 314                 .ifa_flags = 0,
 315                 .ifa_scope = 0,
 316                 .ifa_index = ifindex, };
 317         struct nl_cb *cb = nl_cb_alloc(NL_CB_DEFAULT);
 318         struct addr_info ctxt = {
 319                 .ifindex = ifindex,
 320                 .af = v6? AF_INET6: AF_INET,
 321                 .addrs = addrs,
 322                 .ret = 0,
 323                 .pending = 1,
 324         };
 325
 326         if (!cb) {
 327                 ctxt.ret = -1;
 328                 goto out;
 329         }
 330
 331         msg = nlmsg_alloc_simple(RTM_GETADDR, NLM_F_REQUEST | NLM_F_DUMP);
 332
 333         if (!msg) {
 334                 ctxt.ret = - 1;
 335                 goto out;
 336         }
 337
 338         nlmsg_append(msg, &ifa, sizeof(ifa), 0);
 339
 340         nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, cb_valid_handler, &ctxt);
 341         nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, cb_finish_handler, &ctxt);
 342         nl_cb_err(cb, NL_CB_CUSTOM, cb_error_handler, &ctxt);
 343
 344         nl_send_auto_complete(rtnl_socket, msg);
 345         while (ctxt.pending > 0)
 346                 nl_recvmsgs(rtnl_socket, cb);
 347
 348         nlmsg_free(msg);
 349
 350         if (ctxt.ret <= 0)
 351                 goto out;
 352
 353         time_t now = odhcpd_time();
 354         struct odhcpd_ipaddr *addr = *addrs;
 355
 356         qsort(addr, ctxt.ret, sizeof(*addr), prefixcmp);
 357
 358         for (ssize_t i = 0; i < ctxt.ret; ++i) {
 359                 if (addr[i].preferred < UINT32_MAX - now)
 360                         addr[i].preferred += now;
 361
 362                 if (addr[i].valid < UINT32_MAX - now)
 363                         addr[i].valid += now;
 364         }
 365
 366 out:
 367         nl_cb_put(cb);
 368
 369         return ctxt.ret;
 370 }
 371
 372 static int odhcpd_get_linklocal_interface_address(int ifindex, struct in6_addr *lladdr)
 373 {
 374         int status = -1;
 375         struct sockaddr_in6 addr = {AF_INET6, 0, 0, ALL_IPV6_ROUTERS, ifindex};
 376         socklen_t alen = sizeof(addr);
 377         int sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6);
 378
 379         if (!connect(sock, (struct sockaddr*)&addr, sizeof(addr)) &&
 380                         !getsockname(sock, (struct sockaddr*)&addr, &alen)) {
 381                 *lladdr = addr.sin6_addr;
 382                 status = 0;
 383         }
 384
 385         close(sock);
 386
 387         return status;
 388 }
 389
 390 /*
 391  * DNS address selection criteria order :
 392  * - use IPv6 address with valid lifetime if none is yet selected
 393  * - use IPv6 address with a preferred lifetime if the already selected IPv6 address is deprecated
 394  * - use an IPv6 ULA address if the already selected IPv6 address is not an ULA address
 395  * - use the IPv6 address with the longest preferred lifetime
 396  */
 397 int odhcpd_get_interface_dns_addr(const struct interface *iface, struct in6_addr *addr)
 398 {
 399         time_t now = odhcpd_time();
 400         ssize_t m = -1;
 401
 402         for (size_t i = 0; i < iface->ia_addr_len; ++i) {
 403                 if (iface->ia_addr[i].valid <= (uint32_t)now)
 404                         continue;
 405
 406                 if (m < 0) {
 407                         m = i;
 408                         continue;
 409                 }
 410
 411                 if (iface->ia_addr[m].preferred >= (uint32_t)now &&
 412                                 iface->ia_addr[i].preferred < (uint32_t)now)
 413                         continue;
 414
 415                 if (IN6_IS_ADDR_ULA(&iface->ia_addr[i].addr.in6)) {
 416                         if (!IN6_IS_ADDR_ULA(&iface->ia_addr[m].addr.in6)) {
 417                                 m = i;
 418                                 continue;
 419                         }
 420                 } else if (IN6_IS_ADDR_ULA(&iface->ia_addr[m].addr.in6))
 421                         continue;
 422
 423                 if (iface->ia_addr[i].preferred > iface->ia_addr[m].preferred)
 424                         m = i;
 425         }
 426
 427         if (m >= 0) {
 428                 *addr = iface->ia_addr[m].addr.in6;
 429                 return 0;
 430         }
 431
 432         return odhcpd_get_linklocal_interface_address(iface->ifindex, addr);
 433 }
 434
 435 int odhcpd_setup_route(const struct in6_addr *addr, const int prefixlen,
 436                 const struct interface *iface, const struct in6_addr *gw,
 437                 const uint32_t metric, const bool add)
 438 {
 439         struct nl_msg *msg;
 440         struct rtmsg rtm = {
 441                 .rtm_family = AF_INET6,
 442                 .rtm_dst_len = prefixlen,
 443                 .rtm_src_len = 0,
 444                 .rtm_table = RT_TABLE_MAIN,
 445                 .rtm_protocol = (add ? RTPROT_STATIC : RTPROT_UNSPEC),
 446                 .rtm_scope = (add ? (gw ? RT_SCOPE_UNIVERSE : RT_SCOPE_LINK) : RT_SCOPE_NOWHERE),
 447                 .rtm_type = (add ? RTN_UNICAST : RTN_UNSPEC),
 448         };
 449         int ret = 0;
 450
 451         msg = nlmsg_alloc_simple(add ? RTM_NEWROUTE : RTM_DELROUTE,
 452                                         add ? NLM_F_CREATE | NLM_F_REPLACE : 0);
 453         if (!msg)
 454                 return -1;
 455
 456         nlmsg_append(msg, &rtm, sizeof(rtm), 0);
 457
 458         nla_put(msg, RTA_DST, sizeof(*addr), addr);
 459         nla_put_u32(msg, RTA_OIF, iface->ifindex);
 460         nla_put_u32(msg, RTA_PRIORITY, metric);
 461
 462         if (gw)
 463                 nla_put(msg, RTA_GATEWAY, sizeof(*gw), gw);
 464
 465         ret = nl_send_auto_complete(rtnl_socket, msg);
 466         nlmsg_free(msg);
 467
 468         if (ret < 0)
 469                 return ret;
 470
 471         return nl_wait_for_ack(rtnl_socket);
 472 }
 473
 474 int odhcpd_setup_proxy_neigh(const struct in6_addr *addr,
 475                 const struct interface *iface, const bool add)
 476 {
 477         struct nl_msg *msg;
 478         struct ndmsg ndm = {
 479                 .ndm_family = AF_INET6,
 480                 .ndm_flags = NTF_PROXY,
 481                 .ndm_ifindex = iface->ifindex,
 482         };
 483         int ret = 0, flags = NLM_F_REQUEST;
 484
 485         if (add)
 486                 flags |= NLM_F_REPLACE | NLM_F_CREATE;
 487
 488         msg = nlmsg_alloc_simple(add ? RTM_NEWNEIGH : RTM_DELNEIGH, flags);
 489         if (!msg)
 490                 return -1;
 491
 492         nlmsg_append(msg, &ndm, sizeof(ndm), 0);
 493
 494         nla_put(msg, NDA_DST, sizeof(*addr), addr);
 495
 496         ret = nl_send_auto_complete(rtnl_socket, msg);
 497         nlmsg_free(msg);
 498
 499         if (ret < 0)
 500                 return ret;
 501
 502         return nl_wait_for_ack(rtnl_socket);
 503 }
 504
 505 struct interface* odhcpd_get_interface_by_index(int ifindex)
 506 {
 507         struct interface *iface;
 508         list_for_each_entry(iface, &interfaces, head)
 509                 if (iface->ifindex == ifindex)
 510                         return iface;
 511
 512         return NULL;
 513 }
 514
 515
 516 struct interface* odhcpd_get_interface_by_name(const char *name)
 517 {
 518         struct interface *iface;
 519         list_for_each_entry(iface, &interfaces, head)
 520                 if (!strcmp(iface->ifname, name))
 521                         return iface;
 522
 523         return NULL;
 524 }
 525
 526
 527 struct interface* odhcpd_get_master_interface(void)
 528 {
 529         struct interface *iface;
 530         list_for_each_entry(iface, &interfaces, head)
 531                 if (iface->master)
 532                         return iface;
 533
 534         return NULL;
 535 }
 536
 537
 538 // Convenience function to receive and do basic validation of packets
 539 static void odhcpd_receive_packets(struct uloop_fd *u, _unused unsigned int events)
 540 {
 541         struct odhcpd_event *e = container_of(u, struct odhcpd_event, uloop);
 542
 543         uint8_t data_buf[RELAYD_BUFFER_SIZE], cmsg_buf[128];
 544         union {
 545                 struct sockaddr_in6 in6;
 546                 struct sockaddr_in in;
 547                 struct sockaddr_ll ll;
 548                 struct sockaddr_nl nl;
 549         } addr;
 550
 551         if (u->error) {
 552                 int ret = -1;
 553                 socklen_t ret_len = sizeof(ret);
 554                 getsockopt(u->fd, SOL_SOCKET, SO_ERROR, &ret, &ret_len);
 555                 u->error = false;
 556                 if (e->handle_error)
 557                         e->handle_error(e, ret);
 558         }
 559
 560         if (e->recv_msgs) {
 561                 e->recv_msgs(e);
 562                 return;
 563         }
 564
 565         while (true) {
 566                 struct iovec iov = {data_buf, sizeof(data_buf)};
 567                 struct msghdr msg = {
 568                         .msg_name = (void *) &addr,
 569                         .msg_namelen = sizeof(addr),
 570                         .msg_iov = &iov,
 571                         .msg_iovlen = 1,
 572                         .msg_control = cmsg_buf,
 573                         .msg_controllen = sizeof(cmsg_buf),
 574                         .msg_flags = 0
 575                 };
 576
 577                 ssize_t len = recvmsg(u->fd, &msg, MSG_DONTWAIT);
 578                 if (len < 0) {
 579                         if (errno == EAGAIN)
 580                                 break;
 581                         else
 582                                 continue;
 583                 }
 584
 585
 586                 // Extract destination interface
 587                 int destiface = 0;
 588                 int *hlim = NULL;
 589                 void *dest = NULL;
 590                 struct in6_pktinfo *pktinfo;
 591                 struct in_pktinfo *pkt4info;
 592                 for (struct cmsghdr *ch = CMSG_FIRSTHDR(&msg); ch != NULL; ch = CMSG_NXTHDR(&msg, ch)) {
 593                         if (ch->cmsg_level == IPPROTO_IPV6 &&
 594                                         ch->cmsg_type == IPV6_PKTINFO) {
 595                                 pktinfo = (struct in6_pktinfo*)CMSG_DATA(ch);
 596                                 destiface = pktinfo->ipi6_ifindex;
 597                                 dest = &pktinfo->ipi6_addr;
 598                         } else if (ch->cmsg_level == IPPROTO_IP &&
 599                                         ch->cmsg_type == IP_PKTINFO) {
 600                                 pkt4info = (struct in_pktinfo*)CMSG_DATA(ch);
 601                                 destiface = pkt4info->ipi_ifindex;
 602                                 dest = &pkt4info->ipi_addr;
 603                         } else if (ch->cmsg_level == IPPROTO_IPV6 &&
 604                                         ch->cmsg_type == IPV6_HOPLIMIT) {
 605                                 hlim = (int*)CMSG_DATA(ch);
 606                         }
 607                 }
 608
 609                 // Check hoplimit if received
 610                 if (hlim && *hlim != 255)
 611                         continue;
 612
 613                 // Detect interface for packet sockets
 614                 if (addr.ll.sll_family == AF_PACKET)
 615                         destiface = addr.ll.sll_ifindex;
 616
 617                 struct interface *iface =
 618                                 odhcpd_get_interface_by_index(destiface);
 619
 620                 if (!iface && addr.nl.nl_family != AF_NETLINK)
 621                         continue;
 622
 623                 char ipbuf[INET6_ADDRSTRLEN] = "kernel";
 624                 if (addr.ll.sll_family == AF_PACKET &&
 625                                 len >= (ssize_t)sizeof(struct ip6_hdr))
 626                         inet_ntop(AF_INET6, &data_buf[8], ipbuf, sizeof(ipbuf));
 627                 else if (addr.in6.sin6_family == AF_INET6)
 628                         inet_ntop(AF_INET6, &addr.in6.sin6_addr, ipbuf, sizeof(ipbuf));
 629                 else if (addr.in.sin_family == AF_INET)
 630                         inet_ntop(AF_INET, &addr.in.sin_addr, ipbuf, sizeof(ipbuf));
 631
 632                 syslog(LOG_DEBUG, "Received %li Bytes from %s%%%s", (long)len,
 633                                 ipbuf, (iface) ? iface->ifname : "netlink");
 634
 635                 e->handle_dgram(&addr, data_buf, len, iface, dest);
 636         }
 637 }
 638
 639 // Register events for the multiplexer
 640 int odhcpd_register(struct odhcpd_event *event)
 641 {
 642         event->uloop.cb = odhcpd_receive_packets;
 643         return uloop_fd_add(&event->uloop, ULOOP_READ |
 644                         ((event->handle_error) ? ULOOP_ERROR_CB : 0));
 645 }
 646
 647 int odhcpd_deregister(struct odhcpd_event *event)
 648 {
 649         event->uloop.cb = NULL;
 650         return uloop_fd_delete(&event->uloop);
 651 }
 652
 653 void odhcpd_process(struct odhcpd_event *event)
 654 {
 655         odhcpd_receive_packets(&event->uloop, 0);
 656 }
 657
 658 int odhcpd_urandom(void *data, size_t len)
 659 {
 660         return read(urandom_fd, data, len);
 661 }
 662
 663
 664 time_t odhcpd_time(void)
 665 {
 666         struct timespec ts;
 667         syscall(SYS_clock_gettime, CLOCK_MONOTONIC, &ts);
 668         return ts.tv_sec;
 669 }
 670
 671
 672 static const char hexdigits[] = "0123456789abcdef";
 673 static const int8_t hexvals[] = {
 674     -1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -2, -1, -1, -2, -1, -1,
 675     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 676     -2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 677      0,  1,  2,  3,  4,  5,  6,  7,  8,  9, -1, -1, -1, -1, -1, -1,
 678     -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 679     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 680     -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 681     -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
 682 };
 683
 684 ssize_t odhcpd_unhexlify(uint8_t *dst, size_t len, const char *src)
 685 {
 686         size_t c;
 687         for (c = 0; c < len && src[0] && src[1]; ++c) {
 688                 int8_t x = (int8_t)*src++;
 689                 int8_t y = (int8_t)*src++;
 690                 if (x < 0 || (x = hexvals[x]) < 0
 691                                 || y < 0 || (y = hexvals[y]) < 0)
 692                         return -1;
 693                 dst[c] = x << 4 | y;
 694                 while (((int8_t)*src) < 0 ||
 695                                 (*src && hexvals[(uint8_t)*src] < 0))
 696                         src++;
 697         }
 698
 699         return c;
 700 }
 701
 702
 703 void odhcpd_hexlify(char *dst, const uint8_t *src, size_t len)
 704 {
 705         for (size_t i = 0; i < len; ++i) {
 706                 *dst++ = hexdigits[src[i] >> 4];
 707                 *dst++ = hexdigits[src[i] & 0x0f];
 708         }
 709         *dst = 0;
 710 }
 711
 712
 713 int odhcpd_bmemcmp(const void *av, const void *bv, size_t bits)
 714 {
 715         const uint8_t *a = av, *b = bv;
 716         size_t bytes = bits / 8;
 717         bits %= 8;
 718
 719         int res = memcmp(a, b, bytes);
 720         if (res == 0 && bits > 0)
 721                 res = (a[bytes] >> (8 - bits)) - (b[bytes] >> (8 - bits));
 722
 723         return res;
 724 }
 725
 726
 727 void odhcpd_bmemcpy(void *av, const void *bv, size_t bits)
 728 {
 729         uint8_t *a = av;
 730         const uint8_t *b = bv;
 731
 732         size_t bytes = bits / 8;
 733         bits %= 8;
 734         memcpy(a, b, bytes);
 735
 736         if (bits > 0) {
 737                 uint8_t mask = (1 << (8 - bits)) - 1;
 738                 a[bytes] = (a[bytes] & mask) | ((~mask) & b[bytes]);
 739         }
 740 }