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         rtnl_wilddump_request(&rth, AF_INET, RTM_GETNEIGH);
 432 }
 433
 434 static void get_kern_msg(void)
 435 {
 436         int status;
 437         struct nlmsghdr *h;
 438         struct sockaddr_nl nladdr;
 439         struct iovec iov;
 440         char   buf[8192];
 441         struct msghdr msg = {
 442                 (void*)&nladdr, sizeof(nladdr),
 443                 &iov,   1,
 444                 NULL,   0,
 445                 0
 446         };
 447
 448         memset(&nladdr, 0, sizeof(nladdr));
 449
 450         iov.iov_base = buf;
 451         iov.iov_len = sizeof(buf);
 452
 453         status = recvmsg(rth.fd, &msg, MSG_DONTWAIT);
 454
 455         if (status <= 0)
 456                 return;
 457
 458         if (msg.msg_namelen != sizeof(nladdr))
 459                 return;
 460
 461         if (nladdr.nl_pid)
 462                 return;
 463
 464         for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
 465                 int len = h->nlmsg_len;
 466                 int l = len - sizeof(*h);
 467
 468                 if (l < 0 || len > status)
 469                         return;
 470
 471                 if (do_one_request(h) < 0)
 472                         return;
 473
 474                 status -= NLMSG_ALIGN(len);
 475                 h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
 476         }
 477 }
 478
 479 /* Receive gratuitous ARP messages and store them, that's all. */
 480 static void get_arp_pkt(void)
 481 {
 482         unsigned char buf[1024];
 483         struct sockaddr_ll sll;
 484         socklen_t sll_len = sizeof(sll);
 485         struct arphdr *a = (struct arphdr*)buf;
 486         struct dbkey key;
 487         DBT dbkey, dbdat;
 488         int n;
 489
 490         n = recvfrom(pset[0].fd, buf, sizeof(buf), MSG_DONTWAIT,
 491                      (struct sockaddr*)&sll, &sll_len);
 492         if (n < 0) {
 493                 if (errno != EINTR && errno != EAGAIN)
 494                         syslog(LOG_ERR, "recvfrom: %m");
 495                 return;
 496         }
 497
 498         if (ifnum && !handle_if(sll.sll_ifindex))
 499                 return;
 500
 501         /* Sanity checks */
 502
 503         if (n < sizeof(*a) ||
 504             (a->ar_op != htons(ARPOP_REQUEST) &&
 505              a->ar_op != htons(ARPOP_REPLY)) ||
 506             a->ar_pln != 4 ||
 507             a->ar_pro != htons(ETH_P_IP) ||
 508             a->ar_hln != sll.sll_halen ||
 509             sizeof(*a) + 2*4 + 2*a->ar_hln > n)
 510                 return;
 511
 512         key.iface = sll.sll_ifindex;
 513         memcpy(&key.addr, (char*)(a+1) + a->ar_hln, 4);
 514
 515         /* DAD message, ignore. */
 516         if (key.addr == 0)
 517                 return;
 518
 519         dbkey.data = &key;
 520         dbkey.size = sizeof(key);
 521
 522         if (dbase->get(dbase, &dbkey, &dbdat, 0) == 0 && !IS_NEG(dbdat.data)) {
 523                 if (memcmp(dbdat.data, a+1, dbdat.size) == 0)
 524                         return;
 525                 stats.arp_change++;
 526         } else {
 527                 stats.arp_new++;
 528         }
 529
 530         dbdat.data = a+1;
 531         dbdat.size = a->ar_hln;
 532         dbase->put(dbase, &dbkey, &dbdat, 0);
 533 }
 534
 535 static void catch_signal(int sig, void (*handler)(int))
 536 {
 537         struct sigaction sa;
 538
 539         memset(&sa, 0, sizeof(sa));
 540         sa.sa_handler = handler;
 541 #ifdef SA_INTERRUPT
 542         sa.sa_flags = SA_INTERRUPT;
 543 #endif
 544         sigaction(sig, &sa, NULL);
 545 }
 546
 547 #include <setjmp.h>
 548 sigjmp_buf env;
 549 volatile int in_poll;
 550
 551 static void sig_exit(int signo)
 552 {
 553         do_exit = 1;
 554         if (in_poll)
 555                 siglongjmp(env, 1);
 556 }
 557
 558 static void sig_sync(int signo)
 559 {
 560         do_sync = 1;
 561         if (in_poll)
 562                 siglongjmp(env, 1);
 563 }
 564
 565 static void sig_stats(int signo)
 566 {
 567         do_sync = 1;
 568         do_stats = 1;
 569         if (in_poll)
 570                 siglongjmp(env, 1);
 571 }
 572
 573 static void send_stats(void)
 574 {
 575         syslog(LOG_INFO, "arp_rcv: n%lu c%lu app_rcv: tot %lu hits %lu bad %lu neg %lu sup %lu",
 576                stats.arp_new, stats.arp_change,
 577
 578                stats.app_recv, stats.app_success,
 579                stats.app_bad, stats.app_neg, stats.app_suppressed
 580                );
 581         syslog(LOG_INFO, "kern: n%lu c%lu neg %lu arp_send: %lu rlim %lu",
 582                stats.kern_new, stats.kern_change, stats.kern_neg,
 583
 584                stats.probes_sent, stats.probes_suppressed
 585                );
 586         do_stats = 0;
 587 }
 588
 589
 590 int main(int argc, char **argv)
 591 {
 592         int opt;
 593         int do_list = 0;
 594         char *do_load = NULL;
 595
 596         while ((opt = getopt(argc, argv, "h?b:lf:a:n:p:kR:B:")) != EOF) {
 597                 switch (opt) {
 598                 case 'b':
 599                         dbname = optarg;
 600                         break;
 601                 case 'f':
 602                         if (do_load) {
 603                                 fprintf(stderr, "Duplicate option -f\n");
 604                                 usage();
 605                         }
 606                         do_load = optarg;
 607                         break;
 608                 case 'l':
 609                         do_list = 1;
 610                         break;
 611                 case 'a':
 612                         active_probing = atoi(optarg);
 613                         break;
 614                 case 'n':
 615                         negative_timeout = atoi(optarg);
 616                         break;
 617                 case 'k':
 618                         no_kernel_broadcasts = 1;
 619                         break;
 620                 case 'p':
 621                         if ((poll_timeout = 1000 * strtod(optarg, NULL)) < 100) {
 622                                 fprintf(stderr,"Invalid poll timeout\n");
 623                                 exit(-1);
 624                         }
 625                         break;
 626                 case 'R':
 627                         if ((broadcast_rate = atoi(optarg)) <= 0 ||
 628                             (broadcast_rate = 1000/broadcast_rate) <= 0) {
 629                                 fprintf(stderr, "Invalid ARP rate\n");
 630                                 exit(-1);
 631                         }
 632                         break;
 633                 case 'B':
 634                         if ((broadcast_burst = atoi(optarg)) <= 0 ||
 635                             (broadcast_burst = 1000*broadcast_burst) <= 0) {
 636                                 fprintf(stderr, "Invalid ARP burst\n");
 637                                 exit(-1);
 638                         }
 639                         break;
 640                 case 'h':
 641                 case '?':
 642                 default:
 643                         usage();
 644                 }
 645         }
 646         argc -= optind;
 647         argv += optind;
 648
 649         if (argc > 0) {
 650                 ifnum = argc;
 651                 ifnames = argv;
 652                 ifvec = malloc(argc*sizeof(int));
 653                 if (!ifvec) {
 654                         perror("malloc");
 655                         exit(-1);
 656                 }
 657         }
 658
 659         if ((udp_sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
 660                 perror("socket");
 661                 exit(-1);
 662         }
 663
 664         if (ifnum) {
 665                 int i;
 666                 struct ifreq ifr;
 667                 memset(&ifr, 0, sizeof(ifr));
 668                 for (i=0; i<ifnum; i++) {
 669                         strncpy(ifr.ifr_name, ifnames[i], IFNAMSIZ);
 670                         if (ioctl(udp_sock, SIOCGIFINDEX, &ifr)) {
 671                                 perror("ioctl(SIOCGIFINDEX)");
 672                                 exit(-1);;
 673                         }
 674                         ifvec[i] = ifr.ifr_ifindex;
 675                 }
 676         }
 677
 678         dbase = dbopen(dbname, O_CREAT|O_RDWR, 0644, DB_HASH, NULL);
 679         if (dbase == NULL) {
 680                 perror("db_open");
 681                 exit(-1);
 682         }
 683
 684         if (do_load) {
 685                 char buf[128];
 686                 FILE *fp;
 687                 struct dbkey k;
 688                 DBT dbkey, dbdat;
 689
 690                 dbkey.data = &k;
 691                 dbkey.size = sizeof(k);
 692
 693                 if (strcmp(do_load, "-") == 0 || strcmp(do_load, "--") == 0) {
 694                         fp = stdin;
 695                 } else if ((fp = fopen(do_load, "r")) == NULL) {
 696                         perror("fopen");
 697                         goto do_abort;
 698                 }
 699
 700                 buf[sizeof(buf)-1] = 0;
 701                 while (fgets(buf, sizeof(buf)-1, fp)) {
 702                         __u8 b1[6];
 703                         char ipbuf[128];
 704                         char macbuf[128];
 705
 706                         if (buf[0] == '#')
 707                                 continue;
 708
 709                         if (sscanf(buf, "%u%s%s", &k.iface, ipbuf, macbuf) != 3) {
 710                                 fprintf(stderr, "Wrong format of input file \"%s\"\n", do_load);
 711                                 goto do_abort;
 712                         }
 713                         if (strncmp(macbuf, "FAILED:", 7) == 0)
 714                                 continue;
 715                         if (!inet_aton(ipbuf, (struct in_addr*)&k.addr)) {
 716                                 fprintf(stderr, "Invalid IP address: \"%s\"\n", ipbuf);
 717                                 goto do_abort;
 718                         }
 719
 720                         dbdat.data = hexstring_a2n(macbuf, b1, 6);
 721                         if (dbdat.data == NULL)
 722                                 goto do_abort;
 723                         dbdat.size = 6;
 724
 725                         if (dbase->put(dbase, &dbkey, &dbdat, 0)) {
 726                                 perror("hash->put");
 727                                 goto do_abort;
 728                         }
 729                 }
 730                 dbase->sync(dbase, 0);
 731                 if (fp != stdin)
 732                         fclose(fp);
 733         }
 734
 735         if (do_list) {
 736                 DBT dbkey, dbdat;
 737                 printf("%-8s %-15s %s\n", "#Ifindex", "IP", "MAC");
 738                 while (dbase->seq(dbase, &dbkey, &dbdat, R_NEXT) == 0) {
 739                         struct dbkey *key = dbkey.data;
 740                         if (handle_if(key->iface)) {
 741                                 if (!IS_NEG(dbdat.data)) {
 742                                         char b1[18];
 743                                         printf("%-8d %-15s %s\n",
 744                                                key->iface,
 745                                                inet_ntoa(*(struct in_addr*)&key->addr),
 746                                                hexstring_n2a(dbdat.data, 6, b1, 18));
 747                                 } else {
 748                                         printf("%-8d %-15s FAILED: %dsec ago\n",
 749                                                key->iface,
 750                                                inet_ntoa(*(struct in_addr*)&key->addr),
 751                                                NEG_AGE(dbdat.data));
 752                                 }
 753                         }
 754                 }
 755         }
 756
 757         if (do_load || do_list)
 758                 goto out;
 759
 760         pset[0].fd = socket(PF_PACKET, SOCK_DGRAM, 0);
 761         if (pset[0].fd < 0) {
 762                 perror("socket");
 763                 exit(-1);
 764         }
 765
 766         if (1) {
 767                 struct sockaddr_ll sll;
 768                 memset(&sll, 0, sizeof(sll));
 769                 sll.sll_family = AF_PACKET;
 770                 sll.sll_protocol = htons(ETH_P_ARP);
 771                 sll.sll_ifindex = (ifnum == 1 ? ifvec[0] : 0);
 772                 if (bind(pset[0].fd, (struct sockaddr*)&sll, sizeof(sll)) < 0) {
 773                         perror("bind");
 774                         goto do_abort;
 775                 }
 776         }
 777
 778         if (rtnl_open(&rth, RTMGRP_NEIGH) < 0) {
 779                 perror("rtnl_open");
 780                 goto do_abort;
 781         }
 782         pset[1].fd = rth.fd;
 783
 784         load_initial_table();
 785
 786         if (daemon(0, 0)) {
 787                 perror("arpd: daemon");
 788                 goto do_abort;
 789         }
 790
 791         openlog("arpd", LOG_PID | LOG_CONS, LOG_DAEMON);
 792         catch_signal(SIGINT, sig_exit);
 793         catch_signal(SIGTERM, sig_exit);
 794         catch_signal(SIGHUP, sig_sync);
 795         catch_signal(SIGUSR1, sig_stats);
 796
 797 #define EVENTS (POLLIN|POLLPRI|POLLERR|POLLHUP)
 798         pset[0].events = EVENTS;
 799         pset[0].revents = 0;
 800         pset[1].events = EVENTS;
 801         pset[1].revents = 0;
 802
 803         sigsetjmp(env, 1);
 804
 805         for (;;) {
 806                 in_poll = 1;
 807
 808                 if (do_exit)
 809                         break;
 810                 if (do_sync) {
 811                         in_poll = 0;
 812                         dbase->sync(dbase, 0);
 813                         do_sync = 0;
 814                         in_poll = 1;
 815                 }
 816                 if (do_stats)
 817                         send_stats();
 818                 if (poll(pset, 2, poll_timeout) > 0) {
 819                         in_poll = 0;
 820                         if (pset[0].revents&EVENTS)
 821                                 get_arp_pkt();
 822                         if (pset[1].revents&EVENTS)
 823                                 get_kern_msg();
 824                 } else {
 825                         do_sync = 1;
 826                 }
 827         }
 828
 829         undo_sysctl_adjustments();
 830 out:
 831         dbase->close(dbase);
 832         exit(0);
 833
 834 do_abort:
 835         dbase->close(dbase);
 836         exit(-1);
 837 }