misc/arpd.c

   1 /*
   2  * arpd.c       ARP helper daemon.
   3  *
   4  *              This program is free software; you can redistribute it and/or
   5  *              modify it under the terms of the GNU General Public License
   6  *              as published by the Free Software Foundation; either version
   7  *              2 of the License, or (at your option) any later version.
   8  *
   9  * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  */
  11
  12 #include <stdio.h>
  13 #include <syslog.h>
  14 #include <malloc.h>
  15 #include <string.h>
  16 #include <unistd.h>
  17 #include <stdlib.h>
  18 #include <netdb.h>
  19 #include <db_185.h>
  20 #include <sys/ioctl.h>
  21 #include <sys/poll.h>
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <sys/uio.h>
  25 #include <sys/socket.h>
  26 #include <sys/time.h>
  27 #include <time.h>
  28 #include <signal.h>
  29 #include <linux/if.h>
  30 #include <linux/if_ether.h>
  31 #include <linux/if_arp.h>
  32 #include <netinet/in.h>
  33 #include <arpa/inet.h>
  34 #include <linux/if_packet.h>
  35 #include <linux/filter.h>
  36
  37 #include "libnetlink.h"
  38 #include "utils.h"
  39
  40 int resolve_hosts;
  41
  42 DB      *dbase;
  43 char    *dbname = "/var/lib/arpd/arpd.db";
  44
  45 int     ifnum;
  46 int     *ifvec;
  47 char    **ifnames;
  48
  49 struct dbkey
  50 {
  51         __u32   iface;
  52         __u32   addr;
  53 };
  54
  55 #define IS_NEG(x)       (((__u8*)(x))[0] == 0xFF)
  56 #define NEG_TIME(x)     (((x)[2]<<24)|((x)[3]<<16)|((x)[4]<<8)|(x)[5])
  57 #define NEG_AGE(x)      ((__u32)time(NULL) - NEG_TIME((__u8*)x))
  58 #define NEG_VALID(x)    (NEG_AGE(x) < negative_timeout)
  59 #define NEG_CNT(x)      (((__u8*)(x))[1])
  60
  61 struct rtnl_handle rth;
  62
  63 struct pollfd pset[2];
  64 int udp_sock = -1;
  65
  66 volatile int do_exit;
  67 volatile int do_sync;
  68 volatile int do_stats;
  69
  70 struct {
  71         unsigned long arp_new;
  72         unsigned long arp_change;
  73
  74         unsigned long app_recv;
  75         unsigned long app_success;
  76         unsigned long app_bad;
  77         unsigned long app_neg;
  78         unsigned long app_suppressed;
  79
  80         unsigned long kern_neg;
  81         unsigned long kern_new;
  82         unsigned long kern_change;
  83
  84         unsigned long probes_sent;
  85         unsigned long probes_suppressed;
  86 } stats;
  87
  88 int active_probing;
  89 int negative_timeout = 60;
  90 int no_kernel_broadcasts;
  91 int broadcast_rate = 1000;
  92 int broadcast_burst = 3000;
  93 int poll_timeout = 30000;
  94
  95 static void usage(void)
  96 {
  97         fprintf(stderr,
  98                 "Usage: arpd [ -lkh? ] [ -a N ] [ -b dbase ] [ -B number ]"
  99                 " [ -f file ] [ -n time ] [-p interval ] [ -R rate ] [ interfaces ]\n");
 100         exit(1);
 101 }
 102
 103 static int handle_if(int ifindex)
 104 {
 105         int i;
 106
 107         if (ifnum == 0)
 108                 return 1;
 109
 110         for (i=0; i<ifnum; i++)
 111                 if (ifvec[i] == ifindex)
 112                         return 1;
 113         return 0;
 114 }
 115
 116 int sysctl_adjusted;
 117
 118 static void do_sysctl_adjustments(void)
 119 {
 120         int i;
 121
 122         if (!ifnum)
 123                 return;
 124
 125         for (i=0; i<ifnum; i++) {
 126                 char buf[128];
 127                 FILE *fp;
 128
 129                 if (active_probing) {
 130                         sprintf(buf, "/proc/sys/net/ipv4/neigh/%s/mcast_solicit", ifnames[i]);
 131                         if ((fp = fopen(buf, "w")) != NULL) {
 132                                 if (no_kernel_broadcasts)
 133                                         strcpy(buf, "0\n");
 134                                 else
 135                                         sprintf(buf, "%d\n", active_probing>=2 ? 1 : 3-active_probing);
 136                                 fputs(buf, fp);
 137                                 fclose(fp);
 138                         }
 139                 }
 140
 141                 sprintf(buf, "/proc/sys/net/ipv4/neigh/%s/app_solicit", ifnames[i]);
 142                 if ((fp = fopen(buf, "w")) != NULL) {
 143                         sprintf(buf, "%d\n", active_probing<=1 ? 1 : active_probing);
 144                         fputs(buf, fp);
 145                         fclose(fp);
 146                 }
 147         }
 148         sysctl_adjusted = 1;
 149 }
 150
 151 static void undo_sysctl_adjustments(void)
 152 {
 153         int i;
 154
 155         if (!sysctl_adjusted)
 156                 return;
 157
 158         for (i=0; i<ifnum; i++) {
 159                 char buf[128];
 160                 FILE *fp;
 161
 162                 if (active_probing) {
 163                         sprintf(buf, "/proc/sys/net/ipv4/neigh/%s/mcast_solicit", ifnames[i]);
 164                         if ((fp = fopen(buf, "w")) != NULL) {
 165                                 strcpy(buf, "3\n");
 166                                 fputs(buf, fp);
 167                                 fclose(fp);
 168                         }
 169                 }
 170                 sprintf(buf, "/proc/sys/net/ipv4/neigh/%s/app_solicit", ifnames[i]);
 171                 if ((fp = fopen(buf, "w")) != NULL) {
 172                         strcpy(buf, "0\n");
 173                         fputs(buf, fp);
 174                         fclose(fp);
 175                 }
 176         }
 177         sysctl_adjusted = 0;
 178 }
 179
 180
 181 static int send_probe(int ifindex, __u32 addr)
 182 {
 183         struct ifreq ifr;
 184         struct sockaddr_in dst;
 185         socklen_t len;
 186         unsigned char buf[256];
 187         struct arphdr *ah = (struct arphdr*)buf;
 188         unsigned char *p = (unsigned char *)(ah+1);
 189         struct sockaddr_ll sll;
 190
 191         memset(&ifr, 0, sizeof(ifr));
 192         ifr.ifr_ifindex = ifindex;
 193         if (ioctl(udp_sock, SIOCGIFNAME, &ifr))
 194                 return -1;
 195         if (ioctl(udp_sock, SIOCGIFHWADDR, &ifr))
 196                 return -1;
 197         if (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER)
 198                 return -1;
 199         if (setsockopt(udp_sock, SOL_SOCKET, SO_BINDTODEVICE, ifr.ifr_name, strlen(ifr.ifr_name)+1) < 0)
 200                 return -1;
 201
 202         dst.sin_family = AF_INET;
 203         dst.sin_port = htons(1025);
 204         dst.sin_addr.s_addr = addr;
 205         if (connect(udp_sock, (struct sockaddr*)&dst, sizeof(dst)) < 0)
 206                 return -1;
 207         len = sizeof(dst);
 208         if (getsockname(udp_sock, (struct sockaddr*)&dst, &len) < 0)
 209                 return -1;
 210
 211         ah->ar_hrd = htons(ifr.ifr_hwaddr.sa_family);
 212         ah->ar_pro = htons(ETH_P_IP);
 213         ah->ar_hln = 6;
 214         ah->ar_pln = 4;
 215         ah->ar_op  = htons(ARPOP_REQUEST);
 216
 217         memcpy(p, ifr.ifr_hwaddr.sa_data, ah->ar_hln);
 218         p += ah->ar_hln;
 219
 220         memcpy(p, &dst.sin_addr, 4);
 221         p+=4;
 222
 223         sll.sll_family = AF_PACKET;
 224         memset(sll.sll_addr, 0xFF, sizeof(sll.sll_addr));
 225         sll.sll_ifindex = ifindex;
 226         sll.sll_protocol = htons(ETH_P_ARP);
 227         memcpy(p, &sll.sll_addr, ah->ar_hln);
 228         p+=ah->ar_hln;
 229
 230         memcpy(p, &addr, 4);
 231         p+=4;
 232
 233         if (sendto(pset[0].fd, buf, p-buf, 0, (struct sockaddr*)&sll, sizeof(sll)) < 0)
 234                 return -1;
 235         stats.probes_sent++;
 236         return 0;
 237 }
 238
 239 /* Be very tough on sending probes: 1 per second with burst of 3. */
 240
 241 static int queue_active_probe(int ifindex, __u32 addr)
 242 {
 243         static struct timeval prev;
 244         static int buckets;
 245         struct timeval now;
 246
 247         gettimeofday(&now, NULL);
 248         if (prev.tv_sec) {
 249                 int diff = (now.tv_sec-prev.tv_sec)*1000+(now.tv_usec-prev.tv_usec)/1000;
 250                 buckets += diff;
 251         } else {
 252                 buckets = broadcast_burst;
 253         }
 254         if (buckets > broadcast_burst)
 255                 buckets = broadcast_burst;
 256         if (buckets >= broadcast_rate && !send_probe(ifindex, addr)) {
 257                 buckets -= broadcast_rate;
 258                 prev = now;
 259                 return 0;
 260         }
 261         stats.probes_suppressed++;
 262         return -1;
 263 }
 264
 265 static int respond_to_kernel(int ifindex, __u32 addr, char *lla, int llalen)
 266 {
 267         struct {
 268                 struct nlmsghdr         n;
 269                 struct ndmsg            ndm;
 270                 char                    buf[256];
 271         } req;
 272
 273         memset(&req.n, 0, sizeof(req.n));
 274         memset(&req.ndm, 0, sizeof(req.ndm));
 275
 276         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
 277         req.n.nlmsg_flags = NLM_F_REQUEST;
 278         req.n.nlmsg_type = RTM_NEWNEIGH;
 279         req.ndm.ndm_family = AF_INET;
 280         req.ndm.ndm_state = NUD_STALE;
 281         req.ndm.ndm_ifindex = ifindex;
 282         req.ndm.ndm_type = RTN_UNICAST;
 283
 284         addattr_l(&req.n, sizeof(req), NDA_DST, &addr, 4);
 285         addattr_l(&req.n, sizeof(req), NDA_LLADDR, lla, llalen);
 286         return rtnl_send(&rth, &req, req.n.nlmsg_len) <= 0;
 287 }
 288
 289 static void prepare_neg_entry(__u8 *ndata, __u32 stamp)
 290 {
 291         ndata[0] = 0xFF;
 292         ndata[1] = 0;
 293         ndata[2] = stamp>>24;
 294         ndata[3] = stamp>>16;
 295         ndata[4] = stamp>>8;
 296         ndata[5] = stamp;
 297 }
 298
 299
 300 static int do_one_request(struct nlmsghdr *n)
 301 {
 302         struct ndmsg *ndm = NLMSG_DATA(n);
 303         int len = n->nlmsg_len;
 304         struct rtattr * tb[NDA_MAX+1];
 305         struct dbkey key;
 306         DBT dbkey, dbdat;
 307         int do_acct = 0;
 308
 309         if (n->nlmsg_type == NLMSG_DONE) {
 310                 dbase->sync(dbase, 0);
 311
 312                 /* Now we have at least mirror of kernel db, so that
 313                  * may start real resolution.
 314                  */
 315                 do_sysctl_adjustments();
 316                 return 0;
 317         }
 318
 319         if (n->nlmsg_type != RTM_GETNEIGH && n->nlmsg_type != RTM_NEWNEIGH)
 320                 return 0;
 321
 322         len -= NLMSG_LENGTH(sizeof(*ndm));
 323         if (len < 0)
 324                 return -1;
 325
 326         if (ndm->ndm_family != AF_INET ||
 327             (ifnum && !handle_if(ndm->ndm_ifindex)) ||
 328             ndm->ndm_flags ||
 329             ndm->ndm_type != RTN_UNICAST ||
 330             !(ndm->ndm_state&~NUD_NOARP))
 331                 return 0;
 332
 333         parse_rtattr(tb, NDA_MAX, NDA_RTA(ndm), len);
 334
 335         if (!tb[NDA_DST])
 336                 return 0;
 337
 338         key.iface = ndm->ndm_ifindex;
 339         memcpy(&key.addr, RTA_DATA(tb[NDA_DST]), 4);
 340         dbkey.data = &key;
 341         dbkey.size = sizeof(key);
 342
 343         if (dbase->get(dbase, &dbkey, &dbdat, 0) != 0) {
 344                 dbdat.data = 0;
 345                 dbdat.size = 0;
 346         }
 347
 348         if (n->nlmsg_type == RTM_GETNEIGH) {
 349                 if (!(n->nlmsg_flags&NLM_F_REQUEST))
 350                         return 0;
 351
 352                 if (!(ndm->ndm_state&(NUD_PROBE|NUD_INCOMPLETE))) {
 353                         stats.app_bad++;
 354                         return 0;
 355                 }
 356
 357                 if (ndm->ndm_state&NUD_PROBE) {
 358                         /* If we get this, kernel still has some valid
 359                          * address, but unicast probing failed and host
 360                          * is either dead or changed its mac address.
 361                          * Kernel is going to initiate broadcast resolution.
 362                          * OK, we invalidate our information as well.
 363                          */
 364                         if (dbdat.data && !IS_NEG(dbdat.data))
 365                                 stats.app_neg++;
 366
 367                         dbase->del(dbase, &dbkey, 0);
 368                 } else {
 369                         /* If we get this kernel does not have any information.
 370                          * If we have something tell this to kernel. */
 371                         stats.app_recv++;
 372                         if (dbdat.data && !IS_NEG(dbdat.data)) {
 373                                 stats.app_success++;
 374                                 respond_to_kernel(key.iface, key.addr, dbdat.data, dbdat.size);
 375                                 return 0;
 376                         }
 377
 378                         /* Sheeit! We have nothing to tell. */
 379                         /* If we have recent negative entry, be silent. */
 380                         if (dbdat.data && NEG_VALID(dbdat.data)) {
 381                                 if (NEG_CNT(dbdat.data) >= active_probing) {
 382                                         stats.app_suppressed++;
 383                                         return 0;
 384                                 }
 385                                 do_acct = 1;
 386                         }
 387                 }
 388
 389                 if (active_probing &&
 390                     queue_active_probe(ndm->ndm_ifindex, key.addr) == 0 &&
 391                     do_acct) {
 392                         NEG_CNT(dbdat.data)++;
 393                         dbase->put(dbase, &dbkey, &dbdat, 0);
 394                 }
 395         } else if (n->nlmsg_type == RTM_NEWNEIGH) {
 396                 if (n->nlmsg_flags&NLM_F_REQUEST)
 397                         return 0;
 398
 399                 if (ndm->ndm_state&NUD_FAILED) {
 400                         /* Kernel was not able to resolve. Host is dead.
 401                          * Create negative entry if it is not present
 402                          * or renew it if it is too old. */
 403                         if (!dbdat.data ||
 404                             !IS_NEG(dbdat.data) ||
 405                             !NEG_VALID(dbdat.data)) {
 406                                 __u8 ndata[6];
 407                                 stats.kern_neg++;
 408                                 prepare_neg_entry(ndata, time(NULL));
 409                                 dbdat.data = ndata;
 410                                 dbdat.size = sizeof(ndata);
 411                                 dbase->put(dbase, &dbkey, &dbdat, 0);
 412                         }
 413                 } else if (tb[NDA_LLADDR]) {
 414                         if (dbdat.data && !IS_NEG(dbdat.data)) {
 415                                 if (memcmp(RTA_DATA(tb[NDA_LLADDR]), dbdat.data, dbdat.size) == 0)
 416                                         return 0;
 417                                 stats.kern_change++;
 418                         } else {
 419                                 stats.kern_new++;
 420                         }
 421                         dbdat.data = RTA_DATA(tb[NDA_LLADDR]);
 422                         dbdat.size = RTA_PAYLOAD(tb[NDA_LLADDR]);
 423                         dbase->put(dbase, &dbkey, &dbdat, 0);
 424                 }
 425         }
 426         return 0;
 427 }
 428
 429 static void load_initial_table(void)
 430 {
 431         if (rtnl_wilddump_request(&rth, AF_INET, RTM_GETNEIGH) < 0) {
 432                 perror("dump request failed");
 433                 exit(1);
 434         }
 435
 436 }
 437
 438 static void get_kern_msg(void)
 439 {
 440         int status;
 441         struct nlmsghdr *h;
 442         struct sockaddr_nl nladdr;
 443         struct iovec iov;
 444         char   buf[8192];
 445         struct msghdr msg = {
 446                 (void*)&nladdr, sizeof(nladdr),
 447                 &iov,   1,
 448                 NULL,   0,
 449                 0
 450         };
 451
 452         memset(&nladdr, 0, sizeof(nladdr));
 453
 454         iov.iov_base = buf;
 455         iov.iov_len = sizeof(buf);
 456
 457         status = recvmsg(rth.fd, &msg, MSG_DONTWAIT);
 458
 459         if (status <= 0)
 460                 return;
 461
 462         if (msg.msg_namelen != sizeof(nladdr))
 463                 return;
 464
 465         if (nladdr.nl_pid)
 466                 return;
 467
 468         for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
 469                 int len = h->nlmsg_len;
 470                 int l = len - sizeof(*h);
 471
 472                 if (l < 0 || len > status)
 473                         return;
 474
 475                 if (do_one_request(h) < 0)
 476                         return;
 477
 478                 status -= NLMSG_ALIGN(len);
 479                 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
 480         }
 481 }
 482
 483 /* Receive gratuitous ARP messages and store them, that's all. */
 484 static void get_arp_pkt(void)
 485 {
 486         unsigned char buf[1024];
 487         struct sockaddr_ll sll;
 488         socklen_t sll_len = sizeof(sll);
 489         struct arphdr *a = (struct arphdr*)buf;
 490         struct dbkey key;
 491         DBT dbkey, dbdat;
 492         int n;
 493
 494         n = recvfrom(pset[0].fd, buf, sizeof(buf), MSG_DONTWAIT,
 495                      (struct sockaddr*)&sll, &sll_len);
 496         if (n < 0) {
 497                 if (errno != EINTR && errno != EAGAIN)
 498                         syslog(LOG_ERR, "recvfrom: %m");
 499                 return;
 500         }
 501
 502         if (ifnum && !handle_if(sll.sll_ifindex))
 503                 return;
 504
 505         /* Sanity checks */
 506
 507         if (n < sizeof(*a) ||
 508             (a->ar_op != htons(ARPOP_REQUEST) &&
 509              a->ar_op != htons(ARPOP_REPLY)) ||
 510             a->ar_pln != 4 ||
 511             a->ar_pro != htons(ETH_P_IP) ||
 512             a->ar_hln != sll.sll_halen ||
 513             sizeof(*a) + 2*4 + 2*a->ar_hln > n)
 514                 return;
 515
 516         key.iface = sll.sll_ifindex;
 517         memcpy(&key.addr, (char*)(a+1) + a->ar_hln, 4);
 518
 519         /* DAD message, ignore. */
 520         if (key.addr == 0)
 521                 return;
 522
 523         dbkey.data = &key;
 524         dbkey.size = sizeof(key);
 525
 526         if (dbase->get(dbase, &dbkey, &dbdat, 0) == 0 && !IS_NEG(dbdat.data)) {
 527                 if (memcmp(dbdat.data, a+1, dbdat.size) == 0)
 528                         return;
 529                 stats.arp_change++;
 530         } else {
 531                 stats.arp_new++;
 532         }
 533
 534         dbdat.data = a+1;
 535         dbdat.size = a->ar_hln;
 536         dbase->put(dbase, &dbkey, &dbdat, 0);
 537 }
 538
 539 static void catch_signal(int sig, void (*handler)(int))
 540 {
 541         struct sigaction sa;
 542
 543         memset(&sa, 0, sizeof(sa));
 544         sa.sa_handler = handler;
 545 #ifdef SA_INTERRUPT
 546         sa.sa_flags = SA_INTERRUPT;
 547 #endif
 548         sigaction(sig, &sa, NULL);
 549 }
 550
 551 #include <setjmp.h>
 552 sigjmp_buf env;
 553 volatile int in_poll;
 554
 555 static void sig_exit(int signo)
 556 {
 557         do_exit = 1;
 558         if (in_poll)
 559                 siglongjmp(env, 1);
 560 }
 561
 562 static void sig_sync(int signo)
 563 {
 564         do_sync = 1;
 565         if (in_poll)
 566                 siglongjmp(env, 1);
 567 }
 568
 569 static void sig_stats(int signo)
 570 {
 571         do_sync = 1;
 572         do_stats = 1;
 573         if (in_poll)
 574                 siglongjmp(env, 1);
 575 }
 576
 577 static void send_stats(void)
 578 {
 579         syslog(LOG_INFO, "arp_rcv: n%lu c%lu app_rcv: tot %lu hits %lu bad %lu neg %lu sup %lu",
 580                stats.arp_new, stats.arp_change,
 581
 582                stats.app_recv, stats.app_success,
 583                stats.app_bad, stats.app_neg, stats.app_suppressed
 584                );
 585         syslog(LOG_INFO, "kern: n%lu c%lu neg %lu arp_send: %lu rlim %lu",
 586                stats.kern_new, stats.kern_change, stats.kern_neg,
 587
 588                stats.probes_sent, stats.probes_suppressed
 589                );
 590         do_stats = 0;
 591 }
 592
 593
 594 int main(int argc, char **argv)
 595 {
 596         int opt;
 597         int do_list = 0;
 598         char *do_load = NULL;
 599
 600         while ((opt = getopt(argc, argv, "h?b:lf:a:n:p:kR:B:")) != EOF) {
 601                 switch (opt) {
 602                 case 'b':
 603                         dbname = optarg;
 604                         break;
 605                 case 'f':
 606                         if (do_load) {
 607                                 fprintf(stderr, "Duplicate option -f\n");
 608                                 usage();
 609                         }
 610                         do_load = optarg;
 611                         break;
 612                 case 'l':
 613                         do_list = 1;
 614                         break;
 615                 case 'a':
 616                         active_probing = atoi(optarg);
 617                         break;
 618                 case 'n':
 619                         negative_timeout = atoi(optarg);
 620                         break;
 621                 case 'k':
 622                         no_kernel_broadcasts = 1;
 623                         break;
 624                 case 'p':
 625                         if ((poll_timeout = 1000 * strtod(optarg, NULL)) < 100) {
 626                                 fprintf(stderr,"Invalid poll timeout\n");
 627                                 exit(-1);
 628                         }
 629                         break;
 630                 case 'R':
 631                         if ((broadcast_rate = atoi(optarg)) <= 0 ||
 632                             (broadcast_rate = 1000/broadcast_rate) <= 0) {
 633                                 fprintf(stderr, "Invalid ARP rate\n");
 634                                 exit(-1);
 635                         }
 636                         break;
 637                 case 'B':
 638                         if ((broadcast_burst = atoi(optarg)) <= 0 ||
 639                             (broadcast_burst = 1000*broadcast_burst) <= 0) {
 640                                 fprintf(stderr, "Invalid ARP burst\n");
 641                                 exit(-1);
 642                         }
 643                         break;
 644                 case 'h':
 645                 case '?':
 646                 default:
 647                         usage();
 648                 }
 649         }
 650         argc -= optind;
 651         argv += optind;
 652
 653         if (argc > 0) {
 654                 ifnum = argc;
 655                 ifnames = argv;
 656                 ifvec = malloc(argc*sizeof(int));
 657                 if (!ifvec) {
 658                         perror("malloc");
 659                         exit(-1);
 660                 }
 661         }
 662
 663         if ((udp_sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
 664                 perror("socket");
 665                 exit(-1);
 666         }
 667
 668         if (ifnum) {
 669                 int i;
 670                 struct ifreq ifr;
 671                 memset(&ifr, 0, sizeof(ifr));
 672                 for (i=0; i<ifnum; i++) {
 673                         strncpy(ifr.ifr_name, ifnames[i], IFNAMSIZ);
 674                         if (ioctl(udp_sock, SIOCGIFINDEX, &ifr)) {
 675                                 perror("ioctl(SIOCGIFINDEX)");
 676                                 exit(-1);;
 677                         }
 678                         ifvec[i] = ifr.ifr_ifindex;
 679                 }
 680         }
 681
 682         dbase = dbopen(dbname, O_CREAT|O_RDWR, 0644, DB_HASH, NULL);
 683         if (dbase == NULL) {
 684                 perror("db_open");
 685                 exit(-1);
 686         }
 687
 688         if (do_load) {
 689                 char buf[128];
 690                 FILE *fp;
 691                 struct dbkey k;
 692                 DBT dbkey, dbdat;
 693
 694                 dbkey.data = &k;
 695                 dbkey.size = sizeof(k);
 696
 697                 if (strcmp(do_load, "-") == 0 || strcmp(do_load, "--") == 0) {
 698                         fp = stdin;
 699                 } else if ((fp = fopen(do_load, "r")) == NULL) {
 700                         perror("fopen");
 701                         goto do_abort;
 702                 }
 703
 704                 buf[sizeof(buf)-1] = 0;
 705                 while (fgets(buf, sizeof(buf)-1, fp)) {
 706                         __u8 b1[6];
 707                         char ipbuf[128];
 708                         char macbuf[128];
 709
 710                         if (buf[0] == '#')
 711                                 continue;
 712
 713                         if (sscanf(buf, "%u%s%s", &k.iface, ipbuf, macbuf) != 3) {
 714                                 fprintf(stderr, "Wrong format of input file \"%s\"\n", do_load);
 715                                 goto do_abort;
 716                         }
 717                         if (strncmp(macbuf, "FAILED:", 7) == 0)
 718                                 continue;
 719                         if (!inet_aton(ipbuf, (struct in_addr*)&k.addr)) {
 720                                 fprintf(stderr, "Invalid IP address: \"%s\"\n", ipbuf);
 721                                 goto do_abort;
 722                         }
 723
 724                         dbdat.data = hexstring_a2n(macbuf, b1, 6);
 725                         if (dbdat.data == NULL)
 726                                 goto do_abort;
 727                         dbdat.size = 6;
 728
 729                         if (dbase->put(dbase, &dbkey, &dbdat, 0)) {
 730                                 perror("hash->put");
 731                                 goto do_abort;
 732                         }
 733                 }
 734                 dbase->sync(dbase, 0);
 735                 if (fp != stdin)
 736                         fclose(fp);
 737         }
 738
 739         if (do_list) {
 740                 DBT dbkey, dbdat;
 741                 printf("%-8s %-15s %s\n", "#Ifindex", "IP", "MAC");
 742                 while (dbase->seq(dbase, &dbkey, &dbdat, R_NEXT) == 0) {
 743                         struct dbkey *key = dbkey.data;
 744                         if (handle_if(key->iface)) {
 745                                 if (!IS_NEG(dbdat.data)) {
 746                                         char b1[18];
 747                                         printf("%-8d %-15s %s\n",
 748                                                key->iface,
 749                                                inet_ntoa(*(struct in_addr*)&key->addr),
 750                                                hexstring_n2a(dbdat.data, 6, b1, 18));
 751                                 } else {
 752                                         printf("%-8d %-15s FAILED: %dsec ago\n",
 753                                                key->iface,
 754                                                inet_ntoa(*(struct in_addr*)&key->addr),
 755                                                NEG_AGE(dbdat.data));
 756                                 }
 757                         }
 758                 }
 759         }
 760
 761         if (do_load || do_list)
 762                 goto out;
 763
 764         pset[0].fd = socket(PF_PACKET, SOCK_DGRAM, 0);
 765         if (pset[0].fd < 0) {
 766                 perror("socket");
 767                 exit(-1);
 768         }
 769
 770         if (1) {
 771                 struct sockaddr_ll sll;
 772                 memset(&sll, 0, sizeof(sll));
 773                 sll.sll_family = AF_PACKET;
 774                 sll.sll_protocol = htons(ETH_P_ARP);
 775                 sll.sll_ifindex = (ifnum == 1 ? ifvec[0] : 0);
 776                 if (bind(pset[0].fd, (struct sockaddr*)&sll, sizeof(sll)) < 0) {
 777                         perror("bind");
 778                         goto do_abort;
 779                 }
 780         }
 781
 782         if (rtnl_open(&rth, RTMGRP_NEIGH) < 0) {
 783                 perror("rtnl_open");
 784                 goto do_abort;
 785         }
 786         pset[1].fd = rth.fd;
 787
 788         load_initial_table();
 789
 790         if (daemon(0, 0)) {
 791                 perror("arpd: daemon");
 792                 goto do_abort;
 793         }
 794
 795         openlog("arpd", LOG_PID | LOG_CONS, LOG_DAEMON);
 796         catch_signal(SIGINT, sig_exit);
 797         catch_signal(SIGTERM, sig_exit);
 798         catch_signal(SIGHUP, sig_sync);
 799         catch_signal(SIGUSR1, sig_stats);
 800
 801 #define EVENTS (POLLIN|POLLPRI|POLLERR|POLLHUP)
 802         pset[0].events = EVENTS;
 803         pset[0].revents = 0;
 804         pset[1].events = EVENTS;
 805         pset[1].revents = 0;
 806
 807         sigsetjmp(env, 1);
 808
 809         for (;;) {
 810                 in_poll = 1;
 811
 812                 if (do_exit)
 813                         break;
 814                 if (do_sync) {
 815                         in_poll = 0;
 816                         dbase->sync(dbase, 0);
 817                         do_sync = 0;
 818                         in_poll = 1;
 819                 }
 820                 if (do_stats)
 821                         send_stats();
 822                 if (poll(pset, 2, poll_timeout) > 0) {
 823                         in_poll = 0;
 824                         if (pset[0].revents&EVENTS)
 825                                 get_arp_pkt();
 826                         if (pset[1].revents&EVENTS)
 827                                 get_kern_msg();
 828                 } else {
 829                         do_sync = 1;
 830                 }
 831         }
 832
 833         undo_sysctl_adjustments();
 834 out:
 835         dbase->close(dbase);
 836         exit(0);
 837
 838 do_abort:
 839         dbase->close(dbase);
 840         exit(-1);
 841 }