release/src/router/iproute2/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
  94 void usage(void)
  95 {
  96         fprintf(stderr,
  97 "Usage: arpd [ -lk ] [ -a N ] [ -b dbase ] [ -f file ] [ interfaces ]\n");
  98         exit(1);
  99 }
 100
 101 int handle_if(int ifindex)
 102 {
 103         int i;
 104
 105         if (ifnum == 0)
 106                 return 1;
 107
 108         for (i=0; i<ifnum; i++)
 109                 if (ifvec[i] == ifindex)
 110                         return 1;
 111         return 0;
 112 }
 113
 114 int sysctl_adjusted;
 115
 116 void do_sysctl_adjustments(void)
 117 {
 118         int i;
 119
 120         if (!ifnum)
 121                 return;
 122
 123         for (i=0; i<ifnum; i++) {
 124                 char buf[128];
 125                 FILE *fp;
 126
 127                 if (active_probing) {
 128                         sprintf(buf, "/proc/sys/net/ipv4/neigh/%s/mcast_solicit", ifnames[i]);
 129                         if ((fp = fopen(buf, "w")) != NULL) {
 130                                 if (no_kernel_broadcasts)
 131                                         strcpy(buf, "0\n");
 132                                 else
 133                                         sprintf(buf, "%d\n", active_probing>=2 ? 1 : 3-active_probing);
 134                                 fputs(buf, fp);
 135                                 fclose(fp);
 136                         }
 137                 }
 138
 139                 sprintf(buf, "/proc/sys/net/ipv4/neigh/%s/app_solicit", ifnames[i]);
 140                 if ((fp = fopen(buf, "w")) != NULL) {
 141                         sprintf(buf, "%d\n", active_probing<=1 ? 1 : active_probing);
 142                         fputs(buf, fp);
 143                         fclose(fp);
 144                 }
 145         }
 146         sysctl_adjusted = 1;
 147 }
 148
 149 void undo_sysctl_adjustments(void)
 150 {
 151         int i;
 152
 153         if (!sysctl_adjusted)
 154                 return;
 155
 156         for (i=0; i<ifnum; i++) {
 157                 char buf[128];
 158                 FILE *fp;
 159
 160                 if (active_probing) {
 161                         sprintf(buf, "/proc/sys/net/ipv4/neigh/%s/mcast_solicit", ifnames[i]);
 162                         if ((fp = fopen(buf, "w")) != NULL) {
 163                                 strcpy(buf, "3\n");
 164                                 fputs(buf, fp);
 165                                 fclose(fp);
 166                         }
 167                 }
 168                 sprintf(buf, "/proc/sys/net/ipv4/neigh/%s/app_solicit", ifnames[i]);
 169                 if ((fp = fopen(buf, "w")) != NULL) {
 170                         strcpy(buf, "0\n");
 171                         fputs(buf, fp);
 172                         fclose(fp);
 173                 }
 174         }
 175         sysctl_adjusted = 0;
 176 }
 177
 178
 179 int send_probe(int ifindex, __u32 addr)
 180 {
 181         struct ifreq ifr;
 182         struct sockaddr_in dst;
 183         socklen_t len;
 184         unsigned char buf[256];
 185         struct arphdr *ah = (struct arphdr*)buf;
 186         unsigned char *p = (unsigned char *)(ah+1);
 187         struct sockaddr_ll sll;
 188
 189         memset(&ifr, 0, sizeof(ifr));
 190         ifr.ifr_ifindex = ifindex;
 191         if (ioctl(udp_sock, SIOCGIFNAME, &ifr))
 192                 return -1;
 193         if (ioctl(udp_sock, SIOCGIFHWADDR, &ifr))
 194                 return -1;
 195         if (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER)
 196                 return -1;
 197         if (setsockopt(udp_sock, SOL_SOCKET, SO_BINDTODEVICE, ifr.ifr_name, strlen(ifr.ifr_name)+1) < 0)
 198                 return -1;
 199
 200         dst.sin_family = AF_INET;
 201         dst.sin_port = htons(1025);
 202         dst.sin_addr.s_addr = addr;
 203         if (connect(udp_sock, (struct sockaddr*)&dst, sizeof(dst)) < 0)
 204                 return -1;
 205         len = sizeof(dst);
 206         if (getsockname(udp_sock, (struct sockaddr*)&dst, &len) < 0)
 207                 return -1;
 208
 209         ah->ar_hrd = htons(ifr.ifr_hwaddr.sa_family);
 210         ah->ar_pro = htons(ETH_P_IP);
 211         ah->ar_hln = 6;
 212         ah->ar_pln = 4;
 213         ah->ar_op  = htons(ARPOP_REQUEST);
 214
 215         memcpy(p, ifr.ifr_hwaddr.sa_data, ah->ar_hln);
 216         p += ah->ar_hln;
 217
 218         memcpy(p, &dst.sin_addr, 4);
 219         p+=4;
 220
 221         sll.sll_family = AF_PACKET;
 222         memset(sll.sll_addr, 0xFF, sizeof(sll.sll_addr));
 223         sll.sll_ifindex = ifindex;
 224         sll.sll_protocol = htons(ETH_P_ARP);
 225         memcpy(p, &sll.sll_addr, ah->ar_hln);
 226         p+=ah->ar_hln;
 227
 228         memcpy(p, &addr, 4);
 229         p+=4;
 230
 231         if (sendto(pset[0].fd, buf, p-buf, 0, (struct sockaddr*)&sll, sizeof(sll)) < 0)
 232                 return -1;
 233         stats.probes_sent++;
 234         return 0;
 235 }
 236
 237 /* Be very tough on sending probes: 1 per second with burst of 3. */
 238
 239 int queue_active_probe(int ifindex, __u32 addr)
 240 {
 241         static struct timeval prev;
 242         static int buckets;
 243         struct timeval now;
 244
 245         gettimeofday(&now, NULL);
 246         if (prev.tv_sec) {
 247                 int diff = (now.tv_sec-prev.tv_sec)*1000+(now.tv_usec-prev.tv_usec)/1000;
 248                 buckets += diff;
 249         } else {
 250                 buckets = broadcast_burst;
 251         }
 252         if (buckets > broadcast_burst)
 253                 buckets = broadcast_burst;
 254         if (buckets >= broadcast_rate && !send_probe(ifindex, addr)) {
 255                 buckets -= broadcast_rate;
 256                 prev = now;
 257                 return 0;
 258         }
 259         stats.probes_suppressed++;
 260         return -1;
 261 }
 262
 263 int respond_to_kernel(int ifindex, __u32 addr, char *lla, int llalen)
 264 {
 265         struct {
 266                 struct nlmsghdr         n;
 267                 struct ndmsg            ndm;
 268                 char                    buf[256];
 269         } req;
 270
 271         memset(&req.n, 0, sizeof(req.n));
 272         memset(&req.ndm, 0, sizeof(req.ndm));
 273
 274         req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg));
 275         req.n.nlmsg_flags = NLM_F_REQUEST;
 276         req.n.nlmsg_type = RTM_NEWNEIGH;
 277         req.ndm.ndm_family = AF_INET;
 278         req.ndm.ndm_state = NUD_STALE;
 279         req.ndm.ndm_ifindex = ifindex;
 280         req.ndm.ndm_type = RTN_UNICAST;
 281
 282         addattr_l(&req.n, sizeof(req), NDA_DST, &addr, 4);
 283         addattr_l(&req.n, sizeof(req), NDA_LLADDR, lla, llalen);
 284         return rtnl_send(&rth, (char*)&req, req.n.nlmsg_len) <= 0;
 285 }
 286
 287 void prepare_neg_entry(__u8 *ndata, __u32 stamp)
 288 {
 289         ndata[0] = 0xFF;
 290         ndata[1] = 0;
 291         ndata[2] = stamp>>24;
 292         ndata[3] = stamp>>16;
 293         ndata[4] = stamp>>8;
 294         ndata[5] = stamp;
 295 }
 296
 297
 298 int do_one_request(struct nlmsghdr *n)
 299 {
 300         struct ndmsg *ndm = NLMSG_DATA(n);
 301         int len = n->nlmsg_len;
 302         struct rtattr * tb[NDA_MAX+1];
 303         struct dbkey key;
 304         DBT dbkey, dbdat;
 305         int do_acct = 0;
 306
 307         if (n->nlmsg_type == NLMSG_DONE) {
 308                 dbase->sync(dbase, 0);
 309
 310                 /* Now we have at least mirror of kernel db, so that
 311                  * may start real resolution.
 312                  */
 313                 do_sysctl_adjustments();
 314                 return 0;
 315         }
 316
 317         if (n->nlmsg_type != RTM_GETNEIGH && n->nlmsg_type != RTM_NEWNEIGH)
 318                 return 0;
 319
 320         len -= NLMSG_LENGTH(sizeof(*ndm));
 321         if (len < 0)
 322                 return -1;
 323
 324         if (ndm->ndm_family != AF_INET ||
 325             (ifnum && !handle_if(ndm->ndm_ifindex)) ||
 326             ndm->ndm_flags ||
 327             ndm->ndm_type != RTN_UNICAST ||
 328             !(ndm->ndm_state&~NUD_NOARP))
 329                 return 0;
 330
 331         parse_rtattr(tb, NDA_MAX, NDA_RTA(ndm), len);
 332
 333         if (!tb[NDA_DST])
 334                 return 0;
 335
 336         key.iface = ndm->ndm_ifindex;
 337         memcpy(&key.addr, RTA_DATA(tb[NDA_DST]), 4);
 338         dbkey.data = &key;
 339         dbkey.size = sizeof(key);
 340
 341         if (dbase->get(dbase, &dbkey, &dbdat, 0) != 0) {
 342                 dbdat.data = 0;
 343                 dbdat.size = 0;
 344         }
 345
 346         if (n->nlmsg_type == RTM_GETNEIGH) {
 347                 if (!(n->nlmsg_flags&NLM_F_REQUEST))
 348                         return 0;
 349
 350                 if (!(ndm->ndm_state&(NUD_PROBE|NUD_INCOMPLETE))) {
 351                         stats.app_bad++;
 352                         return 0;
 353                 }
 354
 355                 if (ndm->ndm_state&NUD_PROBE) {
 356                         /* If we get this, kernel still has some valid
 357                          * address, but unicast probing failed and host
 358                          * is either dead or changed its mac address.
 359                          * Kernel is going to initiate broadcast resolution.
 360                          * OK, we invalidate our information as well.
 361                          */
 362                         if (dbdat.data && !IS_NEG(dbdat.data))
 363                                 stats.app_neg++;
 364
 365                         dbase->del(dbase, &dbkey, 0);
 366                 } else {
 367                         /* If we get this kernel does not have any information.
 368                          * If we have something tell this to kernel. */
 369                         stats.app_recv++;
 370                         if (dbdat.data && !IS_NEG(dbdat.data)) {
 371                                 stats.app_success++;
 372                                 respond_to_kernel(key.iface, key.addr, dbdat.data, dbdat.size);
 373                                 return 0;
 374                         }
 375
 376                         /* Sheeit! We have nothing to tell. */
 377                         /* If we have recent negative entry, be silent. */
 378                         if (dbdat.data && NEG_VALID(dbdat.data)) {
 379                                 if (NEG_CNT(dbdat.data) >= active_probing) {
 380                                         stats.app_suppressed++;
 381                                         return 0;
 382                                 }
 383                                 do_acct = 1;
 384                         }
 385                 }
 386
 387                 if (active_probing &&
 388                     queue_active_probe(ndm->ndm_ifindex, key.addr) == 0 &&
 389                     do_acct) {
 390                         NEG_CNT(dbdat.data)++;
 391                         dbase->put(dbase, &dbkey, &dbdat, 0);
 392                 }
 393         } else if (n->nlmsg_type == RTM_NEWNEIGH) {
 394                 if (n->nlmsg_flags&NLM_F_REQUEST)
 395                         return 0;
 396
 397                 if (ndm->ndm_state&NUD_FAILED) {
 398                         /* Kernel was not able to resolve. Host is dead.
 399                          * Create negative entry if it is not present
 400                          * or renew it if it is too old. */
 401                         if (!dbdat.data ||
 402                             !IS_NEG(dbdat.data) ||
 403                             !NEG_VALID(dbdat.data)) {
 404                                 __u8 ndata[6];
 405                                 stats.kern_neg++;
 406                                 prepare_neg_entry(ndata, time(NULL));
 407                                 dbdat.data = ndata;
 408                                 dbdat.size = sizeof(ndata);
 409                                 dbase->put(dbase, &dbkey, &dbdat, 0);
 410                         }
 411                 } else if (tb[NDA_LLADDR]) {
 412                         if (dbdat.data && !IS_NEG(dbdat.data)) {
 413                                 if (memcmp(RTA_DATA(tb[NDA_LLADDR]), dbdat.data, dbdat.size) == 0)
 414                                         return 0;
 415                                 stats.kern_change++;
 416                         } else {
 417                                 stats.kern_new++;
 418                         }
 419                         dbdat.data = RTA_DATA(tb[NDA_LLADDR]);
 420                         dbdat.size = RTA_PAYLOAD(tb[NDA_LLADDR]);
 421                         dbase->put(dbase, &dbkey, &dbdat, 0);
 422                 }
 423         }
 424         return 0;
 425 }
 426
 427 void load_initial_table(void)
 428 {
 429         rtnl_wilddump_request(&rth, AF_INET, RTM_GETNEIGH);
 430 }
 431
 432 void get_kern_msg(void)
 433 {
 434         int status;
 435         struct nlmsghdr *h;
 436         struct sockaddr_nl nladdr;
 437         struct iovec iov;
 438         char   buf[8192];
 439         struct msghdr msg = {
 440                 (void*)&nladdr, sizeof(nladdr),
 441                 &iov,   1,
 442                 NULL,   0,
 443                 0
 444         };
 445
 446         memset(&nladdr, 0, sizeof(nladdr));
 447
 448         iov.iov_base = buf;
 449         iov.iov_len = sizeof(buf);
 450
 451         status = recvmsg(rth.fd, &msg, MSG_DONTWAIT);
 452
 453         if (status <= 0)
 454                 return;
 455
 456         if (msg.msg_namelen != sizeof(nladdr))
 457                 return;
 458
 459         if (nladdr.nl_pid)
 460                 return;
 461
 462         for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
 463                 int len = h->nlmsg_len;
 464                 int l = len - sizeof(*h);
 465
 466                 if (l < 0 || len > status)
 467                         return;
 468
 469                 if (do_one_request(h) < 0)
 470                         return;
 471
 472                 status -= NLMSG_ALIGN(len);
 473                 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
 474         }
 475 }
 476
 477 /* Receive gratuitous ARP messages and store them, that's all. */
 478 void get_arp_pkt(void)
 479 {
 480         unsigned char buf[1024];
 481         struct sockaddr_ll sll;
 482         socklen_t sll_len = sizeof(sll);
 483         struct arphdr *a = (struct arphdr*)buf;
 484         struct dbkey key;
 485         DBT dbkey, dbdat;
 486         int n;
 487
 488         n = recvfrom(pset[0].fd, buf, sizeof(buf), MSG_DONTWAIT,
 489                      (struct sockaddr*)&sll, &sll_len);
 490         if (n < 0) {
 491                 if (errno != EINTR && errno != EAGAIN)
 492                         syslog(LOG_ERR, "recvfrom: %m");
 493                 return;
 494         }
 495
 496         if (ifnum && !handle_if(sll.sll_ifindex))
 497                 return;
 498
 499         /* Sanity checks */
 500
 501         if (n < sizeof(*a) ||
 502             (a->ar_op != htons(ARPOP_REQUEST) &&
 503              a->ar_op != htons(ARPOP_REPLY)) ||
 504             a->ar_pln != 4 ||
 505             a->ar_pro != htons(ETH_P_IP) ||
 506             a->ar_hln != sll.sll_halen ||
 507             sizeof(*a) + 2*4 + 2*a->ar_hln > n)
 508                 return;
 509
 510         key.iface = sll.sll_ifindex;
 511         memcpy(&key.addr, (char*)(a+1) + a->ar_hln, 4);
 512
 513         /* DAD message, ignore. */
 514         if (key.addr == 0)
 515                 return;
 516
 517         dbkey.data = &key;
 518         dbkey.size = sizeof(key);
 519
 520         if (dbase->get(dbase, &dbkey, &dbdat, 0) == 0 && !IS_NEG(dbdat.data)) {
 521                 if (memcmp(dbdat.data, a+1, dbdat.size) == 0)
 522                         return;
 523                 stats.arp_change++;
 524         } else {
 525                 stats.arp_new++;
 526         }
 527
 528         dbdat.data = a+1;
 529         dbdat.size = a->ar_hln;
 530         dbase->put(dbase, &dbkey, &dbdat, 0);
 531 }
 532
 533 void catch_signal(int sig, void (*handler)(int))
 534 {
 535         struct sigaction sa;
 536
 537         memset(&sa, 0, sizeof(sa));
 538         sa.sa_handler = handler;
 539 #ifdef SA_INTERRUPT
 540         sa.sa_flags = SA_INTERRUPT;
 541 #endif
 542         sigaction(sig, &sa, NULL);
 543 }
 544
 545 #include <setjmp.h>
 546 sigjmp_buf env;
 547 volatile int in_poll;
 548
 549 void sig_exit(int signo)
 550 {
 551         do_exit = 1;
 552         if (in_poll)
 553                 siglongjmp(env, 1);
 554 }
 555
 556 void sig_sync(int signo)
 557 {
 558         do_sync = 1;
 559         if (in_poll)
 560                 siglongjmp(env, 1);
 561 }
 562
 563 void sig_stats(int signo)
 564 {
 565         do_sync = 1;
 566         do_stats = 1;
 567         if (in_poll)
 568                 siglongjmp(env, 1);
 569 }
 570
 571 void send_stats(void)
 572 {
 573         syslog(LOG_INFO, "arp_rcv: n%lu c%lu app_rcv: tot %lu hits %lu bad %lu neg %lu sup %lu",
 574                stats.arp_new, stats.arp_change,
 575
 576                stats.app_recv, stats.app_success,
 577                stats.app_bad, stats.app_neg, stats.app_suppressed
 578                );
 579         syslog(LOG_INFO, "kern: n%lu c%lu neg %lu arp_send: %lu rlim %lu",
 580                stats.kern_new, stats.kern_change, stats.kern_neg,
 581
 582                stats.probes_sent, stats.probes_suppressed
 583                );
 584         do_stats = 0;
 585 }
 586
 587
 588 int main(int argc, char **argv)
 589 {
 590         int opt;
 591         int do_list = 0;
 592         char *do_load = NULL;
 593
 594         while ((opt = getopt(argc, argv, "h?b:lf:a:n:kR:B:")) != EOF) {
 595                 switch (opt) {
 596                 case 'b':
 597                         dbname = optarg;
 598                         break;
 599                 case 'f':
 600                         if (do_load) {
 601                                 fprintf(stderr, "Duplicate option -f\n");
 602                                 usage();
 603                         }
 604                         do_load = optarg;
 605                         break;
 606                 case 'l':
 607                         do_list = 1;
 608                         break;
 609                 case 'a':
 610                         active_probing = atoi(optarg);
 611                         break;
 612                 case 'n':
 613                         negative_timeout = atoi(optarg);
 614                         break;
 615                 case 'k':
 616                         no_kernel_broadcasts = 1;
 617                         break;
 618                 case 'R':
 619                         if ((broadcast_rate = atoi(optarg)) <= 0 ||
 620                             (broadcast_rate = 1000/broadcast_rate) <= 0) {
 621                                 fprintf(stderr, "Invalid ARP rate\n");
 622                                 exit(-1);
 623                         }
 624                         break;
 625                 case 'B':
 626                         if ((broadcast_burst = atoi(optarg)) <= 0 ||
 627                             (broadcast_burst = 1000*broadcast_burst) <= 0) {
 628                                 fprintf(stderr, "Invalid ARP burst\n");
 629                                 exit(-1);
 630                         }
 631                         break;
 632                 case 'h':
 633                 case '?':
 634                 default:
 635                         usage();
 636                 }
 637         }
 638         argc -= optind;
 639         argv += optind;
 640
 641         if (argc > 0) {
 642                 ifnum = argc;
 643                 ifnames = argv;
 644                 ifvec = malloc(argc*sizeof(int));
 645                 if (!ifvec) {
 646                         perror("malloc");
 647                         exit(-1);
 648                 }
 649         }
 650
 651         if ((udp_sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
 652                 perror("socket");
 653                 exit(-1);
 654         }
 655
 656         if (ifnum) {
 657                 int i;
 658                 struct ifreq ifr;
 659                 memset(&ifr, 0, sizeof(ifr));
 660                 for (i=0; i<ifnum; i++) {
 661                         strncpy(ifr.ifr_name, ifnames[i], IFNAMSIZ);
 662                         if (ioctl(udp_sock, SIOCGIFINDEX, &ifr)) {
 663                                 perror("ioctl(SIOCGIFINDEX)");
 664                                 exit(-1);;
 665                         }
 666                         ifvec[i] = ifr.ifr_ifindex;
 667                 }
 668         }
 669
 670         dbase = dbopen(dbname, O_CREAT|O_RDWR, 0644, DB_HASH, NULL);
 671         if (dbase == NULL) {
 672                 perror("db_open");
 673                 exit(-1);
 674         }
 675
 676         if (do_load) {
 677                 char buf[128];
 678                 FILE *fp;
 679                 struct dbkey k;
 680                 DBT dbkey, dbdat;
 681
 682                 dbkey.data = &k;
 683                 dbkey.size = sizeof(k);
 684
 685                 if (strcmp(do_load, "-") == 0 || strcmp(do_load, "--") == 0) {
 686                         fp = stdin;
 687                 } else if ((fp = fopen(do_load, "r")) == NULL) {
 688                         perror("fopen");
 689                         goto do_abort;
 690                 }
 691
 692                 buf[sizeof(buf)-1] = 0;
 693                 while (fgets(buf, sizeof(buf)-1, fp)) {
 694                         __u8 b1[6];
 695                         char ipbuf[128];
 696                         char macbuf[128];
 697
 698                         if (buf[0] == '#')
 699                                 continue;
 700
 701                         if (sscanf(buf, "%u%s%s", &k.iface, ipbuf, macbuf) != 3) {
 702                                 fprintf(stderr, "Wrong format of input file \"%s\"\n", do_load);
 703                                 goto do_abort;
 704                         }
 705                         if (strncmp(macbuf, "FAILED:", 7) == 0)
 706                                 continue;
 707                         if (!inet_aton(ipbuf, (struct in_addr*)&k.addr)) {
 708                                 fprintf(stderr, "Invalid IP address: \"%s\"\n", ipbuf);
 709                                 goto do_abort;
 710                         }
 711
 712                         dbdat.data = hexstring_a2n(macbuf, b1, 6);
 713                         if (dbdat.data == NULL)
 714                                 goto do_abort;
 715                         dbdat.size = 6;
 716
 717                         if (dbase->put(dbase, &dbkey, &dbdat, 0)) {
 718                                 perror("hash->put");
 719                                 goto do_abort;
 720                         }
 721                 }
 722                 dbase->sync(dbase, 0);
 723                 if (fp != stdin)
 724                         fclose(fp);
 725         }
 726
 727         if (do_list) {
 728                 DBT dbkey, dbdat;
 729                 printf("%-8s %-15s %s\n", "#Ifindex", "IP", "MAC");
 730                 while (dbase->seq(dbase, &dbkey, &dbdat, R_NEXT) == 0) {
 731                         struct dbkey *key = dbkey.data;
 732                         if (handle_if(key->iface)) {
 733                                 if (!IS_NEG(dbdat.data)) {
 734                                         char b1[18];
 735                                         printf("%-8d %-15s %s\n",
 736                                                key->iface,
 737                                                inet_ntoa(*(struct in_addr*)&key->addr),
 738                                                hexstring_n2a(dbdat.data, 6, b1, 18));
 739                                 } else {
 740                                         printf("%-8d %-15s FAILED: %dsec ago\n",
 741                                                key->iface,
 742                                                inet_ntoa(*(struct in_addr*)&key->addr),
 743                                                NEG_AGE(dbdat.data));
 744                                 }
 745                         }
 746                 }
 747         }
 748
 749         if (do_load || do_list)
 750                 goto out;
 751
 752         pset[0].fd = socket(PF_PACKET, SOCK_DGRAM, 0);
 753         if (pset[0].fd < 0) {
 754                 perror("socket");
 755                 exit(-1);
 756         }
 757
 758         if (1) {
 759                 struct sockaddr_ll sll;
 760                 memset(&sll, 0, sizeof(sll));
 761                 sll.sll_family = AF_PACKET;
 762                 sll.sll_protocol = htons(ETH_P_ARP);
 763                 sll.sll_ifindex = (ifnum == 1 ? ifvec[0] : 0);
 764                 if (bind(pset[0].fd, (struct sockaddr*)&sll, sizeof(sll)) < 0) {
 765                         perror("bind");
 766                         goto do_abort;
 767                 }
 768         }
 769
 770         if (rtnl_open(&rth, RTMGRP_NEIGH) < 0) {
 771                 perror("rtnl_open");
 772                 goto do_abort;
 773         }
 774         pset[1].fd = rth.fd;
 775
 776         load_initial_table();
 777
 778         if (1) {
 779                 int fd;
 780                 pid_t pid = fork();
 781
 782                 if (pid > 0)
 783                         _exit(0);
 784                 if (pid < 0) {
 785                         perror("arpd: fork");
 786                         goto do_abort;
 787                 }
 788
 789                 chdir("/");
 790                 fd = open("/dev/null", O_RDWR);
 791                 if (fd >= 0) {
 792                         dup2(fd, 0);
 793                         dup2(fd, 1);
 794                         dup2(fd, 2);
 795                         if (fd > 2)
 796                                 close(fd);
 797                 }
 798                 setsid();
 799         }
 800
 801         openlog("arpd", LOG_PID | LOG_CONS, LOG_DAEMON);
 802         catch_signal(SIGINT, sig_exit);
 803         catch_signal(SIGTERM, sig_exit);
 804         catch_signal(SIGHUP, sig_sync);
 805         catch_signal(SIGUSR1, sig_stats);
 806
 807 #define EVENTS (POLLIN|POLLPRI|POLLERR|POLLHUP)
 808         pset[0].events = EVENTS;
 809         pset[0].revents = 0;
 810         pset[1].events = EVENTS;
 811         pset[1].revents = 0;
 812
 813         sigsetjmp(env, 1);
 814
 815         for (;;) {
 816                 in_poll = 1;
 817
 818                 if (do_exit)
 819                         break;
 820                 if (do_sync) {
 821                         in_poll = 0;
 822                         dbase->sync(dbase, 0);
 823                         do_sync = 0;
 824                         in_poll = 1;
 825                 }
 826                 if (do_stats)
 827                         send_stats();
 828                 if (poll(pset, 2, 30000) > 0) {
 829                         in_poll = 0;
 830                         if (pset[0].revents&EVENTS)
 831                                 get_arp_pkt();
 832                         if (pset[1].revents&EVENTS)
 833                                 get_kern_msg();
 834                 } else {
 835                         do_sync = 1;
 836                 }
 837         }
 838
 839         undo_sysctl_adjustments();
 840 out:
 841         dbase->close(dbase);
 842         exit(0);
 843
 844 do_abort:
 845         dbase->close(dbase);
 846         exit(-1);
 847 }