Lorenzo Colitti | 313379e | 2013-07-11 01:07:11 +0900 | [diff] [blame] | 1 | /* |
| 2 | * rarpd.c RARP 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 <dirent.h> |
| 15 | #include <malloc.h> |
| 16 | #include <string.h> |
| 17 | #include <unistd.h> |
| 18 | #include <stdlib.h> |
| 19 | #include <netdb.h> |
| 20 | #include <arpa/inet.h> |
| 21 | #include <sys/ioctl.h> |
| 22 | #include <sys/poll.h> |
| 23 | #include <sys/errno.h> |
| 24 | #include <sys/fcntl.h> |
| 25 | #include <sys/socket.h> |
| 26 | #include <sys/signal.h> |
| 27 | #include <linux/if.h> |
| 28 | #include <linux/if_arp.h> |
| 29 | #include <netinet/in.h> |
| 30 | #include <linux/if_packet.h> |
| 31 | #include <linux/filter.h> |
| 32 | |
| 33 | int do_reload = 1; |
| 34 | |
| 35 | int debug; |
| 36 | int verbose; |
| 37 | int ifidx; |
| 38 | int allow_offlink; |
| 39 | int only_ethers; |
| 40 | int all_ifaces; |
| 41 | int listen_arp; |
| 42 | char *ifname; |
| 43 | char *tftp_dir = "/etc/tftpboot"; |
| 44 | |
| 45 | extern int ether_ntohost(char *name, unsigned char *ea); |
| 46 | void usage(void) __attribute__((noreturn)); |
| 47 | |
| 48 | struct iflink |
| 49 | { |
| 50 | struct iflink *next; |
| 51 | int index; |
| 52 | int hatype; |
| 53 | unsigned char lladdr[16]; |
| 54 | char name[IFNAMSIZ]; |
| 55 | struct ifaddr *ifa_list; |
| 56 | } *ifl_list; |
| 57 | |
| 58 | struct ifaddr |
| 59 | { |
| 60 | struct ifaddr *next; |
| 61 | __u32 prefix; |
| 62 | __u32 mask; |
| 63 | __u32 local; |
| 64 | }; |
| 65 | |
| 66 | struct rarp_map |
| 67 | { |
| 68 | struct rarp_map *next; |
| 69 | |
| 70 | int ifindex; |
| 71 | int arp_type; |
| 72 | int lladdr_len; |
| 73 | unsigned char lladdr[16]; |
| 74 | __u32 ipaddr; |
| 75 | } *rarp_db; |
| 76 | |
| 77 | void usage() |
| 78 | { |
| 79 | fprintf(stderr, "Usage: rarpd [ -dveaA ] [ -b tftpdir ] [ interface]\n"); |
| 80 | exit(1); |
| 81 | } |
| 82 | |
| 83 | void load_db(void) |
| 84 | { |
| 85 | } |
| 86 | |
| 87 | void load_if(void) |
| 88 | { |
| 89 | int fd; |
| 90 | struct ifreq *ifrp, *ifend; |
| 91 | struct iflink *ifl; |
| 92 | struct ifaddr *ifa; |
| 93 | struct ifconf ifc; |
| 94 | struct ifreq ibuf[256]; |
| 95 | |
| 96 | if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { |
| 97 | syslog(LOG_ERR, "socket: %m"); |
| 98 | return; |
| 99 | } |
| 100 | |
| 101 | ifc.ifc_len = sizeof ibuf; |
| 102 | ifc.ifc_buf = (caddr_t)ibuf; |
| 103 | if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 || |
| 104 | ifc.ifc_len < (int)sizeof(struct ifreq)) { |
| 105 | syslog(LOG_ERR, "SIOCGIFCONF: %m"); |
| 106 | close(fd); |
| 107 | return; |
| 108 | } |
| 109 | |
| 110 | while ((ifl = ifl_list) != NULL) { |
| 111 | while ((ifa = ifl->ifa_list) != NULL) { |
| 112 | ifl->ifa_list = ifa->next; |
| 113 | free(ifa); |
| 114 | } |
| 115 | ifl_list = ifl->next; |
| 116 | free(ifl); |
| 117 | } |
| 118 | |
| 119 | ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len); |
| 120 | for (ifrp = ibuf; ifrp < ifend; ifrp++) { |
| 121 | __u32 addr; |
| 122 | __u32 mask; |
| 123 | __u32 prefix; |
| 124 | |
| 125 | if (ifrp->ifr_addr.sa_family != AF_INET) |
| 126 | continue; |
| 127 | addr = ((struct sockaddr_in*)&ifrp->ifr_addr)->sin_addr.s_addr; |
| 128 | if (addr == 0) |
| 129 | continue; |
| 130 | if (ioctl(fd, SIOCGIFINDEX, ifrp)) { |
| 131 | syslog(LOG_ERR, "ioctl(SIOCGIFNAME): %m"); |
| 132 | continue; |
| 133 | } |
| 134 | if (ifidx && ifrp->ifr_ifindex != ifidx) |
| 135 | continue; |
| 136 | for (ifl = ifl_list; ifl; ifl = ifl->next) |
| 137 | if (ifl->index == ifrp->ifr_ifindex) |
| 138 | break; |
| 139 | if (ifl == NULL) { |
| 140 | char *p; |
| 141 | int index = ifrp->ifr_ifindex; |
| 142 | |
| 143 | if (ioctl(fd, SIOCGIFHWADDR, ifrp)) { |
| 144 | syslog(LOG_ERR, "ioctl(SIOCGIFHWADDR): %m"); |
| 145 | continue; |
| 146 | } |
| 147 | |
| 148 | ifl = (struct iflink*)malloc(sizeof(*ifl)); |
| 149 | if (ifl == NULL) |
| 150 | continue; |
| 151 | memset(ifl, 0, sizeof(*ifl)); |
| 152 | ifl->next = ifl_list; |
| 153 | ifl_list = ifl; |
| 154 | ifl->index = index; |
| 155 | ifl->hatype = ifrp->ifr_hwaddr.sa_family; |
| 156 | memcpy(ifl->lladdr, ifrp->ifr_hwaddr.sa_data, 14); |
| 157 | strncpy(ifl->name, ifrp->ifr_name, IFNAMSIZ); |
| 158 | p = strchr(ifl->name, ':'); |
| 159 | if (p) |
| 160 | *p = 0; |
| 161 | if (verbose) |
| 162 | syslog(LOG_INFO, "link %s", ifl->name); |
| 163 | } |
| 164 | if (ioctl(fd, SIOCGIFNETMASK, ifrp)) { |
| 165 | syslog(LOG_ERR, "ioctl(SIOCGIFMASK): %m"); |
| 166 | continue; |
| 167 | } |
| 168 | mask = ((struct sockaddr_in*)&ifrp->ifr_netmask)->sin_addr.s_addr; |
| 169 | if (ioctl(fd, SIOCGIFDSTADDR, ifrp)) { |
| 170 | syslog(LOG_ERR, "ioctl(SIOCGIFDSTADDR): %m"); |
| 171 | continue; |
| 172 | } |
| 173 | prefix = ((struct sockaddr_in*)&ifrp->ifr_dstaddr)->sin_addr.s_addr; |
| 174 | for (ifa = ifl->ifa_list; ifa; ifa = ifa->next) { |
| 175 | if (ifa->local == addr && |
| 176 | ifa->prefix == prefix && |
| 177 | ifa->mask == mask) |
| 178 | break; |
| 179 | } |
| 180 | if (ifa == NULL) { |
| 181 | if (mask == 0 || prefix == 0) |
| 182 | continue; |
| 183 | ifa = (struct ifaddr*)malloc(sizeof(*ifa)); |
| 184 | memset(ifa, 0, sizeof(*ifa)); |
| 185 | ifa->local = addr; |
| 186 | ifa->prefix = prefix; |
| 187 | ifa->mask = mask; |
| 188 | ifa->next = ifl->ifa_list; |
| 189 | ifl->ifa_list = ifa; |
| 190 | |
| 191 | if (verbose) { |
| 192 | int i; |
| 193 | __u32 m = ~0U; |
| 194 | for (i=32; i>=0; i--) { |
| 195 | if (htonl(m) == mask) |
| 196 | break; |
| 197 | m <<= 1; |
| 198 | } |
| 199 | if (addr == prefix) { |
| 200 | syslog(LOG_INFO, " addr %s/%d on %s\n", |
| 201 | inet_ntoa(*(struct in_addr*)&addr), i, ifl->name); |
| 202 | } else { |
| 203 | char tmpa[64]; |
| 204 | sprintf(tmpa, "%s", inet_ntoa(*(struct in_addr*)&addr)); |
| 205 | syslog(LOG_INFO, " addr %s %s/%d on %s\n", tmpa, |
| 206 | inet_ntoa(*(struct in_addr*)&prefix), i, ifl->name); |
| 207 | } |
| 208 | } |
| 209 | } |
| 210 | } |
| 211 | } |
| 212 | |
| 213 | void configure(void) |
| 214 | { |
| 215 | load_if(); |
| 216 | load_db(); |
| 217 | } |
| 218 | |
| 219 | int bootable(__u32 addr) |
| 220 | { |
| 221 | struct dirent *dent; |
| 222 | DIR *d; |
| 223 | char name[9]; |
| 224 | |
| 225 | sprintf(name, "%08X", (__u32)ntohl(addr)); |
| 226 | d = opendir(tftp_dir); |
| 227 | if (d == NULL) { |
| 228 | syslog(LOG_ERR, "opendir: %m"); |
| 229 | return 0; |
| 230 | } |
| 231 | while ((dent = readdir(d)) != NULL) { |
| 232 | if (strncmp(dent->d_name, name, 8) == 0) |
| 233 | break; |
| 234 | } |
| 235 | closedir(d); |
| 236 | return dent != NULL; |
| 237 | } |
| 238 | |
| 239 | struct ifaddr *select_ipaddr(int ifindex, __u32 *sel_addr, __u32 **alist) |
| 240 | { |
| 241 | struct iflink *ifl; |
| 242 | struct ifaddr *ifa; |
| 243 | int retry = 0; |
| 244 | int i; |
| 245 | |
| 246 | retry: |
| 247 | for (ifl=ifl_list; ifl; ifl=ifl->next) |
| 248 | if (ifl->index == ifindex) |
| 249 | break; |
| 250 | if (ifl == NULL && !retry) { |
| 251 | retry++; |
| 252 | load_if(); |
| 253 | goto retry; |
| 254 | } |
| 255 | if (ifl == NULL) |
| 256 | return NULL; |
| 257 | |
| 258 | for (i=0; alist[i]; i++) { |
| 259 | __u32 addr = *(alist[i]); |
| 260 | for (ifa=ifl->ifa_list; ifa; ifa=ifa->next) { |
| 261 | if (!((ifa->prefix^addr)&ifa->mask)) { |
| 262 | *sel_addr = addr; |
| 263 | return ifa; |
| 264 | } |
| 265 | } |
| 266 | if (ifa == NULL && retry==0) { |
| 267 | retry++; |
| 268 | load_if(); |
| 269 | goto retry; |
| 270 | } |
| 271 | } |
| 272 | if (i==1 && allow_offlink) { |
| 273 | *sel_addr = *(alist[0]); |
| 274 | return ifl->ifa_list; |
| 275 | } |
| 276 | syslog(LOG_ERR, "Off-link request on %s", ifl->name); |
| 277 | return NULL; |
| 278 | } |
| 279 | |
| 280 | struct rarp_map *rarp_lookup(int ifindex, int hatype, |
| 281 | int halen, unsigned char *lladdr) |
| 282 | { |
| 283 | struct rarp_map *r; |
| 284 | |
| 285 | for (r=rarp_db; r; r=r->next) { |
| 286 | if (r->arp_type != hatype && r->arp_type != -1) |
| 287 | continue; |
| 288 | if (r->lladdr_len != halen) |
| 289 | continue; |
| 290 | if (r->ifindex != ifindex && r->ifindex != 0) |
| 291 | continue; |
| 292 | if (memcmp(r->lladdr, lladdr, halen) == 0) |
| 293 | break; |
| 294 | } |
| 295 | |
| 296 | if (r == NULL) { |
| 297 | if (hatype == ARPHRD_ETHER && halen == 6) { |
| 298 | struct ifaddr *ifa; |
| 299 | struct hostent *hp; |
| 300 | char ename[256]; |
| 301 | static struct rarp_map emap = { |
| 302 | NULL, |
| 303 | 0, |
| 304 | ARPHRD_ETHER, |
| 305 | 6, |
| 306 | }; |
| 307 | |
| 308 | if (ether_ntohost(ename, lladdr) != 0 || |
| 309 | (hp = gethostbyname(ename)) == NULL) { |
| 310 | if (verbose) |
| 311 | syslog(LOG_INFO, "not found in /etc/ethers"); |
| 312 | return NULL; |
| 313 | } |
| 314 | if (hp->h_addrtype != AF_INET) { |
| 315 | syslog(LOG_ERR, "no IP address"); |
| 316 | return NULL; |
| 317 | } |
| 318 | ifa = select_ipaddr(ifindex, &emap.ipaddr, (__u32 **)hp->h_addr_list); |
| 319 | if (ifa) { |
| 320 | memcpy(emap.lladdr, lladdr, 6); |
| 321 | if (only_ethers || bootable(emap.ipaddr)) |
| 322 | return &emap; |
| 323 | if (verbose) |
| 324 | syslog(LOG_INFO, "not bootable"); |
| 325 | } |
| 326 | } |
| 327 | } |
| 328 | return r; |
| 329 | } |
| 330 | |
| 331 | static int load_arp_bpflet(int fd) |
| 332 | { |
| 333 | static struct sock_filter insns[] = { |
| 334 | BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6), |
| 335 | BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, ARPOP_RREQUEST, 0, 1), |
| 336 | BPF_STMT(BPF_RET|BPF_K, 1024), |
| 337 | BPF_STMT(BPF_RET|BPF_K, 0), |
| 338 | }; |
| 339 | static struct sock_fprog filter = { |
| 340 | sizeof insns / sizeof(insns[0]), |
| 341 | insns |
| 342 | }; |
| 343 | |
| 344 | return setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)); |
| 345 | } |
| 346 | |
| 347 | int put_mylladdr(unsigned char **ptr_p, int ifindex, int alen) |
| 348 | { |
| 349 | struct iflink *ifl; |
| 350 | |
| 351 | for (ifl=ifl_list; ifl; ifl = ifl->next) |
| 352 | if (ifl->index == ifindex) |
| 353 | break; |
| 354 | |
| 355 | if (ifl==NULL) |
| 356 | return -1; |
| 357 | |
| 358 | memcpy(*ptr_p, ifl->lladdr, alen); |
| 359 | *ptr_p += alen; |
| 360 | return 0; |
| 361 | } |
| 362 | |
| 363 | int put_myipaddr(unsigned char **ptr_p, int ifindex, __u32 hisipaddr) |
| 364 | { |
| 365 | __u32 laddr = 0; |
| 366 | struct iflink *ifl; |
| 367 | struct ifaddr *ifa; |
| 368 | |
| 369 | for (ifl=ifl_list; ifl; ifl = ifl->next) |
| 370 | if (ifl->index == ifindex) |
| 371 | break; |
| 372 | |
| 373 | if (ifl==NULL) |
| 374 | return -1; |
| 375 | |
| 376 | for (ifa=ifl->ifa_list; ifa; ifa=ifa->next) { |
| 377 | if (!((ifa->prefix^hisipaddr)&ifa->mask)) { |
| 378 | laddr = ifa->local; |
| 379 | break; |
| 380 | } |
| 381 | } |
| 382 | memcpy(*ptr_p, &laddr, 4); |
| 383 | *ptr_p += 4; |
| 384 | return 0; |
| 385 | } |
| 386 | |
| 387 | void arp_advise(int ifindex, unsigned char *lladdr, int lllen, __u32 ipaddr) |
| 388 | { |
| 389 | int fd; |
| 390 | struct arpreq req; |
| 391 | struct sockaddr_in *sin; |
| 392 | struct iflink *ifl; |
| 393 | |
| 394 | for (ifl=ifl_list; ifl; ifl = ifl->next) |
| 395 | if (ifl->index == ifindex) |
| 396 | break; |
| 397 | |
| 398 | if (ifl == NULL) |
| 399 | return; |
| 400 | |
| 401 | fd = socket(AF_INET, SOCK_DGRAM, 0); |
| 402 | memset(&req, 0, sizeof(req)); |
| 403 | req.arp_flags = ATF_COM; |
| 404 | sin = (struct sockaddr_in *)&req.arp_pa; |
| 405 | sin->sin_family = AF_INET; |
| 406 | sin->sin_addr.s_addr = ipaddr; |
| 407 | req.arp_ha.sa_family = ifl->hatype; |
| 408 | memcpy(req.arp_ha.sa_data, lladdr, lllen); |
| 409 | memcpy(req.arp_dev, ifl->name, IFNAMSIZ); |
| 410 | |
| 411 | if (ioctl(fd, SIOCSARP, &req)) |
| 412 | syslog(LOG_ERR, "SIOCSARP: %m"); |
| 413 | close(fd); |
| 414 | } |
| 415 | |
| 416 | void serve_it(int fd) |
| 417 | { |
| 418 | unsigned char buf[1024]; |
| 419 | struct sockaddr_ll sll; |
| 420 | socklen_t sll_len = sizeof(sll); |
| 421 | struct arphdr *a = (struct arphdr*)buf; |
| 422 | struct rarp_map *rmap; |
| 423 | unsigned char *ptr; |
| 424 | int n; |
| 425 | |
| 426 | n = recvfrom(fd, buf, sizeof(buf), MSG_DONTWAIT, (struct sockaddr*)&sll, &sll_len); |
| 427 | if (n<0) { |
| 428 | if (errno != EINTR && errno != EAGAIN) |
| 429 | syslog(LOG_ERR, "recvfrom: %m"); |
| 430 | return; |
| 431 | } |
| 432 | |
| 433 | /* Do not accept packets for other hosts and our own ones */ |
| 434 | if (sll.sll_pkttype != PACKET_BROADCAST && |
| 435 | sll.sll_pkttype != PACKET_MULTICAST && |
| 436 | sll.sll_pkttype != PACKET_HOST) |
| 437 | return; |
| 438 | |
| 439 | if (ifidx && sll.sll_ifindex != ifidx) |
| 440 | return; |
| 441 | |
| 442 | if (n<sizeof(*a)) { |
| 443 | syslog(LOG_ERR, "truncated arp packet; len=%d", n); |
| 444 | return; |
| 445 | } |
| 446 | |
| 447 | /* Accept only RARP requests */ |
| 448 | if (a->ar_op != htons(ARPOP_RREQUEST)) |
| 449 | return; |
| 450 | |
| 451 | if (verbose) { |
| 452 | int i; |
| 453 | char tmpbuf[16*3]; |
| 454 | char *ptr = tmpbuf; |
| 455 | for (i=0; i<sll.sll_halen; i++) { |
| 456 | if (i) { |
| 457 | sprintf(ptr, ":%02x", sll.sll_addr[i]); |
| 458 | ptr++; |
| 459 | } else |
| 460 | sprintf(ptr, "%02x", sll.sll_addr[i]); |
| 461 | ptr += 2; |
| 462 | } |
| 463 | syslog(LOG_INFO, "RARP request from %s on if%d", tmpbuf, sll.sll_ifindex); |
| 464 | } |
| 465 | |
| 466 | /* Sanity checks */ |
| 467 | |
| 468 | /* 1. IP only -> pln==4 */ |
| 469 | if (a->ar_pln != 4) { |
| 470 | syslog(LOG_ERR, "interesting rarp_req plen=%d", a->ar_pln); |
| 471 | return; |
| 472 | } |
| 473 | /* 2. ARP protocol must be IP */ |
| 474 | if (a->ar_pro != htons(ETH_P_IP)) { |
| 475 | syslog(LOG_ERR, "rarp protocol is not IP %04x", ntohs(a->ar_pro)); |
| 476 | return; |
| 477 | } |
| 478 | /* 3. ARP types must match */ |
| 479 | if (htons(sll.sll_hatype) != a->ar_hrd) { |
| 480 | switch (sll.sll_hatype) { |
| 481 | case ARPHRD_FDDI: |
| 482 | if (a->ar_hrd == htons(ARPHRD_ETHER) || |
| 483 | a->ar_hrd == htons(ARPHRD_IEEE802)) |
| 484 | break; |
| 485 | default: |
| 486 | syslog(LOG_ERR, "rarp htype mismatch"); |
| 487 | return; |
| 488 | } |
| 489 | } |
| 490 | /* 3. LL address lengths must be equal */ |
| 491 | if (a->ar_hln != sll.sll_halen) { |
| 492 | syslog(LOG_ERR, "rarp hlen mismatch"); |
| 493 | return; |
| 494 | } |
| 495 | /* 4. Check packet length */ |
| 496 | if (sizeof(*a) + 2*4 + 2*a->ar_hln > n) { |
| 497 | syslog(LOG_ERR, "truncated rarp request; len=%d", n); |
| 498 | return; |
| 499 | } |
| 500 | /* 5. Silly check: if this guy set different source |
| 501 | addresses in MAC header and in ARP, he is insane |
| 502 | */ |
| 503 | if (memcmp(sll.sll_addr, a+1, sll.sll_halen)) { |
| 504 | syslog(LOG_ERR, "this guy set different his lladdrs in arp and header"); |
| 505 | return; |
| 506 | } |
| 507 | /* End of sanity checks */ |
| 508 | |
| 509 | /* Lookup requested target in our database */ |
| 510 | rmap = rarp_lookup(sll.sll_ifindex, sll.sll_hatype, |
| 511 | sll.sll_halen, (unsigned char*)(a+1) + sll.sll_halen + 4); |
| 512 | if (rmap == NULL) |
| 513 | return; |
| 514 | |
| 515 | /* Prepare reply. It is almost ready, we only |
| 516 | replace ARP packet type, put our lladdr and |
| 517 | IP address to source fileds, |
| 518 | and fill target IP address. |
| 519 | */ |
| 520 | a->ar_op = htons(ARPOP_RREPLY); |
| 521 | ptr = (unsigned char*)(a+1); |
| 522 | if (put_mylladdr(&ptr, sll.sll_ifindex, rmap->lladdr_len)) |
| 523 | return; |
| 524 | if (put_myipaddr(&ptr, sll.sll_ifindex, rmap->ipaddr)) |
| 525 | return; |
| 526 | /* It is already filled */ |
| 527 | ptr += rmap->lladdr_len; |
| 528 | memcpy(ptr, &rmap->ipaddr, 4); |
| 529 | ptr += 4; |
| 530 | |
| 531 | /* Update our ARP cache. Probably, this guy |
| 532 | will not able to make ARP (if it is broken) |
| 533 | */ |
| 534 | arp_advise(sll.sll_ifindex, rmap->lladdr, rmap->lladdr_len, rmap->ipaddr); |
| 535 | |
| 536 | /* Sendto is blocking, but with 5sec timeout */ |
| 537 | alarm(5); |
| 538 | sendto(fd, buf, ptr - buf, 0, (struct sockaddr*)&sll, sizeof(sll)); |
| 539 | alarm(0); |
| 540 | } |
| 541 | |
| 542 | void catch_signal(int sig, void (*handler)(int)) |
| 543 | { |
| 544 | struct sigaction sa; |
| 545 | |
| 546 | memset(&sa, 0, sizeof(sa)); |
| 547 | sa.sa_handler = handler; |
| 548 | #ifdef SA_INTERRUPT |
| 549 | sa.sa_flags = SA_INTERRUPT; |
| 550 | #endif |
| 551 | sigaction(sig, &sa, NULL); |
| 552 | } |
| 553 | |
| 554 | void sig_alarm(int signo) |
| 555 | { |
| 556 | } |
| 557 | |
| 558 | void sig_hup(int signo) |
| 559 | { |
| 560 | do_reload = 1; |
| 561 | } |
| 562 | |
| 563 | int main(int argc, char **argv) |
| 564 | { |
| 565 | struct pollfd pset[2]; |
| 566 | int psize; |
| 567 | int opt; |
| 568 | |
| 569 | |
| 570 | opterr = 0; |
| 571 | while ((opt = getopt(argc, argv, "aAb:dvoe")) != EOF) { |
| 572 | switch (opt) { |
| 573 | case 'a': |
| 574 | ++all_ifaces; |
| 575 | break; |
| 576 | |
| 577 | case 'A': |
| 578 | ++listen_arp; |
| 579 | break; |
| 580 | |
| 581 | case 'd': |
| 582 | ++debug; |
| 583 | break; |
| 584 | |
| 585 | case 'v': |
| 586 | ++verbose; |
| 587 | break; |
| 588 | |
| 589 | case 'o': |
| 590 | ++allow_offlink; |
| 591 | break; |
| 592 | |
| 593 | case 'e': |
| 594 | ++only_ethers; |
| 595 | break; |
| 596 | |
| 597 | case 'b': |
| 598 | tftp_dir = optarg; |
| 599 | break; |
| 600 | |
| 601 | default: |
| 602 | usage(); |
| 603 | } |
| 604 | } |
| 605 | if (argc > optind) { |
| 606 | if (argc > optind+1) |
| 607 | usage(); |
| 608 | ifname = argv[optind]; |
| 609 | } |
| 610 | |
| 611 | psize = 1; |
| 612 | pset[0].fd = socket(PF_PACKET, SOCK_DGRAM, 0); |
| 613 | |
| 614 | if (ifname) { |
| 615 | struct ifreq ifr; |
| 616 | memset(&ifr, 0, sizeof(ifr)); |
| 617 | strncpy(ifr.ifr_name, ifname, IFNAMSIZ); |
| 618 | if (ioctl(pset[0].fd, SIOCGIFINDEX, &ifr)) { |
| 619 | perror("ioctl(SIOCGIFINDEX)"); |
| 620 | usage(); |
| 621 | } |
| 622 | ifidx = ifr.ifr_ifindex; |
| 623 | } |
| 624 | |
| 625 | pset[1].fd = -1; |
| 626 | if (listen_arp) { |
| 627 | pset[1].fd = socket(PF_PACKET, SOCK_DGRAM, 0); |
| 628 | if (pset[1].fd >= 0) { |
| 629 | load_arp_bpflet(pset[1].fd); |
| 630 | psize = 1; |
| 631 | } |
| 632 | } |
| 633 | |
| 634 | if (pset[1].fd >= 0) { |
| 635 | struct sockaddr_ll sll; |
| 636 | memset(&sll, 0, sizeof(sll)); |
| 637 | sll.sll_family = AF_PACKET; |
| 638 | sll.sll_protocol = htons(ETH_P_ARP); |
| 639 | sll.sll_ifindex = all_ifaces ? 0 : ifidx; |
| 640 | if (bind(pset[1].fd, (struct sockaddr*)&sll, sizeof(sll)) < 0) { |
| 641 | close(pset[1].fd); |
| 642 | pset[1].fd = -1; |
| 643 | psize = 1; |
| 644 | } |
| 645 | } |
| 646 | if (pset[0].fd >= 0) { |
| 647 | struct sockaddr_ll sll; |
| 648 | memset(&sll, 0, sizeof(sll)); |
| 649 | sll.sll_family = AF_PACKET; |
| 650 | sll.sll_protocol = htons(ETH_P_RARP); |
| 651 | sll.sll_ifindex = all_ifaces ? 0 : ifidx; |
| 652 | if (bind(pset[0].fd, (struct sockaddr*)&sll, sizeof(sll)) < 0) { |
| 653 | close(pset[0].fd); |
| 654 | pset[0].fd = -1; |
| 655 | } |
| 656 | } |
| 657 | if (pset[0].fd < 0) { |
| 658 | pset[0] = pset[1]; |
| 659 | psize--; |
| 660 | } |
| 661 | if (psize == 0) { |
| 662 | fprintf(stderr, "failed to bind any socket. Aborting.\n"); |
| 663 | exit(1); |
| 664 | } |
| 665 | |
| 666 | if (!debug) { |
| 667 | int fd; |
| 668 | pid_t pid = fork(); |
| 669 | |
| 670 | if (pid > 0) |
| 671 | exit(0); |
| 672 | else if (pid == -1) { |
| 673 | perror("rarpd: fork"); |
| 674 | exit(1); |
| 675 | } |
| 676 | |
| 677 | if (chdir("/") < 0) { |
| 678 | perror("rarpd: chdir"); |
| 679 | exit(1); |
| 680 | } |
| 681 | |
| 682 | fd = open("/dev/null", O_RDWR); |
| 683 | if (fd >= 0) { |
| 684 | dup2(fd, 0); |
| 685 | dup2(fd, 1); |
| 686 | dup2(fd, 2); |
| 687 | if (fd > 2) |
| 688 | close(fd); |
| 689 | } |
| 690 | setsid(); |
| 691 | } |
| 692 | |
| 693 | openlog("rarpd", LOG_PID | LOG_CONS, LOG_DAEMON); |
| 694 | catch_signal(SIGALRM, sig_alarm); |
| 695 | catch_signal(SIGHUP, sig_hup); |
| 696 | |
| 697 | for (;;) { |
| 698 | int i; |
| 699 | |
| 700 | if (do_reload) { |
| 701 | configure(); |
| 702 | do_reload = 0; |
| 703 | } |
| 704 | |
| 705 | #define EVENTS (POLLIN|POLLPRI|POLLERR|POLLHUP) |
| 706 | pset[0].events = EVENTS; |
| 707 | pset[0].revents = 0; |
| 708 | pset[1].events = EVENTS; |
| 709 | pset[1].revents = 0; |
| 710 | |
| 711 | i = poll(pset, psize, -1); |
| 712 | if (i <= 0) { |
| 713 | if (errno != EINTR && i<0) { |
| 714 | syslog(LOG_ERR, "poll returned some crap: %m\n"); |
| 715 | sleep(10); |
| 716 | } |
| 717 | continue; |
| 718 | } |
| 719 | for (i=0; i<psize; i++) { |
| 720 | if (pset[i].revents&EVENTS) |
| 721 | serve_it(pset[i].fd); |
| 722 | } |
| 723 | } |
| 724 | } |