The Android Open Source Project | 478ab6c | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 1 | /* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */ |
| 2 | /* |
| 3 | * Copyright (c) 1994, 1995, 1996, 1997, 1998 |
| 4 | * The Regents of the University of California. All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 9 | * 1. Redistributions of source code must retain the above copyright |
| 10 | * notice, this list of conditions and the following disclaimer. |
| 11 | * 2. Redistributions in binary form must reproduce the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer in the |
| 13 | * documentation and/or other materials provided with the distribution. |
| 14 | * 3. All advertising materials mentioning features or use of this software |
| 15 | * must display the following acknowledgement: |
| 16 | * This product includes software developed by the Computer Systems |
| 17 | * Engineering Group at Lawrence Berkeley Laboratory. |
| 18 | * 4. Neither the name of the University nor of the Laboratory may be used |
| 19 | * to endorse or promote products derived from this software without |
| 20 | * specific prior written permission. |
| 21 | * |
| 22 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 23 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 24 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 25 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 26 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 27 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 28 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 29 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 30 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 31 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 32 | * SUCH DAMAGE. |
| 33 | */ |
| 34 | |
| 35 | #ifndef lint |
| 36 | static const char rcsid[] _U_ = |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 37 | "@(#) $Header: /tcpdump/master/libpcap/fad-gifc.c,v 1.12 2008-08-06 07:34:09 guy Exp $ (LBL)"; |
The Android Open Source Project | 478ab6c | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 38 | #endif |
| 39 | |
| 40 | #ifdef HAVE_CONFIG_H |
| 41 | #include "config.h" |
| 42 | #endif |
| 43 | |
| 44 | #include <sys/param.h> |
The Android Open Source Project | 478ab6c | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 45 | #include <sys/ioctl.h> |
| 46 | #include <sys/socket.h> |
| 47 | #ifdef HAVE_SYS_SOCKIO_H |
| 48 | #include <sys/sockio.h> |
| 49 | #endif |
| 50 | #include <sys/time.h> /* concession to AIX */ |
| 51 | |
| 52 | struct mbuf; /* Squelch compiler warnings on some platforms for */ |
| 53 | struct rtentry; /* declarations in <net/if.h> */ |
| 54 | #include <net/if.h> |
| 55 | #include <netinet/in.h> |
| 56 | |
| 57 | #include <ctype.h> |
| 58 | #include <errno.h> |
| 59 | #include <memory.h> |
| 60 | #include <stdio.h> |
| 61 | #include <stdlib.h> |
| 62 | #include <string.h> |
| 63 | #include <unistd.h> |
| 64 | |
| 65 | #include "pcap-int.h" |
| 66 | |
| 67 | #ifdef HAVE_OS_PROTO_H |
| 68 | #include "os-proto.h" |
| 69 | #endif |
| 70 | |
| 71 | /* |
| 72 | * This is fun. |
| 73 | * |
| 74 | * In older BSD systems, socket addresses were fixed-length, and |
| 75 | * "sizeof (struct sockaddr)" gave the size of the structure. |
| 76 | * All addresses fit within a "struct sockaddr". |
| 77 | * |
| 78 | * In newer BSD systems, the socket address is variable-length, and |
| 79 | * there's an "sa_len" field giving the length of the structure; |
| 80 | * this allows socket addresses to be longer than 2 bytes of family |
| 81 | * and 14 bytes of data. |
| 82 | * |
| 83 | * Some commercial UNIXes use the old BSD scheme, some use the RFC 2553 |
| 84 | * variant of the old BSD scheme (with "struct sockaddr_storage" rather |
| 85 | * than "struct sockaddr"), and some use the new BSD scheme. |
| 86 | * |
| 87 | * Some versions of GNU libc use neither scheme, but has an "SA_LEN()" |
| 88 | * macro that determines the size based on the address family. Other |
| 89 | * versions don't have "SA_LEN()" (as it was in drafts of RFC 2553 |
| 90 | * but not in the final version). |
| 91 | * |
| 92 | * We assume that a UNIX that doesn't have "getifaddrs()" and doesn't have |
| 93 | * SIOCGLIFCONF, but has SIOCGIFCONF, uses "struct sockaddr" for the |
| 94 | * address in an entry returned by SIOCGIFCONF. |
| 95 | */ |
| 96 | #ifndef SA_LEN |
| 97 | #ifdef HAVE_SOCKADDR_SA_LEN |
| 98 | #define SA_LEN(addr) ((addr)->sa_len) |
| 99 | #else /* HAVE_SOCKADDR_SA_LEN */ |
| 100 | #define SA_LEN(addr) (sizeof (struct sockaddr)) |
| 101 | #endif /* HAVE_SOCKADDR_SA_LEN */ |
| 102 | #endif /* SA_LEN */ |
| 103 | |
| 104 | /* |
| 105 | * This is also fun. |
| 106 | * |
| 107 | * There is no ioctl that returns the amount of space required for all |
| 108 | * the data that SIOCGIFCONF could return, and if a buffer is supplied |
| 109 | * that's not large enough for all the data SIOCGIFCONF could return, |
| 110 | * on at least some platforms it just returns the data that'd fit with |
| 111 | * no indication that there wasn't enough room for all the data, much |
| 112 | * less an indication of how much more room is required. |
| 113 | * |
| 114 | * The only way to ensure that we got all the data is to pass a buffer |
| 115 | * large enough that the amount of space in the buffer *not* filled in |
| 116 | * is greater than the largest possible entry. |
| 117 | * |
| 118 | * We assume that's "sizeof(ifreq.ifr_name)" plus 255, under the assumption |
| 119 | * that no address is more than 255 bytes (on systems where the "sa_len" |
| 120 | * field in a "struct sockaddr" is 1 byte, e.g. newer BSDs, that's the |
| 121 | * case, and addresses are unlikely to be bigger than that in any case). |
| 122 | */ |
| 123 | #define MAX_SA_LEN 255 |
| 124 | |
The Android Open Source Project | 478ab6c | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 125 | /* |
| 126 | * Get a list of all interfaces that are up and that we can open. |
| 127 | * Returns -1 on error, 0 otherwise. |
| 128 | * The list, as returned through "alldevsp", may be null if no interfaces |
| 129 | * were up and could be opened. |
| 130 | * |
| 131 | * This is the implementation used on platforms that have SIOCGIFCONF but |
| 132 | * don't have any other mechanism for getting a list of interfaces. |
| 133 | * |
| 134 | * XXX - or platforms that have other, better mechanisms but for which |
| 135 | * we don't yet have code to use that mechanism; I think there's a better |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 136 | * way on Linux, for example, but if that better way is "getifaddrs()", |
| 137 | * we already have that. |
The Android Open Source Project | 478ab6c | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 138 | */ |
| 139 | int |
JP Abgrall | 511eca3 | 2014-02-12 13:46:45 -0800 | [diff] [blame] | 140 | pcap_findalldevs_interfaces(pcap_if_t **alldevsp, char *errbuf) |
The Android Open Source Project | 478ab6c | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 141 | { |
| 142 | pcap_if_t *devlist = NULL; |
| 143 | register int fd; |
| 144 | register struct ifreq *ifrp, *ifend, *ifnext; |
| 145 | int n; |
| 146 | struct ifconf ifc; |
| 147 | char *buf = NULL; |
| 148 | unsigned buf_size; |
| 149 | #if defined (HAVE_SOLARIS) || defined (HAVE_HPUX10_20_OR_LATER) |
| 150 | char *p, *q; |
| 151 | #endif |
| 152 | struct ifreq ifrflags, ifrnetmask, ifrbroadaddr, ifrdstaddr; |
| 153 | struct sockaddr *netmask, *broadaddr, *dstaddr; |
| 154 | size_t netmask_size, broadaddr_size, dstaddr_size; |
| 155 | int ret = 0; |
| 156 | |
| 157 | /* |
| 158 | * Create a socket from which to fetch the list of interfaces. |
| 159 | */ |
| 160 | fd = socket(AF_INET, SOCK_DGRAM, 0); |
| 161 | if (fd < 0) { |
| 162 | (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 163 | "socket: %s", pcap_strerror(errno)); |
| 164 | return (-1); |
| 165 | } |
| 166 | |
| 167 | /* |
| 168 | * Start with an 8K buffer, and keep growing the buffer until |
| 169 | * we have more than "sizeof(ifrp->ifr_name) + MAX_SA_LEN" |
| 170 | * bytes left over in the buffer or we fail to get the |
| 171 | * interface list for some reason other than EINVAL (which is |
| 172 | * presumed here to mean "buffer is too small"). |
| 173 | */ |
| 174 | buf_size = 8192; |
| 175 | for (;;) { |
| 176 | buf = malloc(buf_size); |
| 177 | if (buf == NULL) { |
| 178 | (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 179 | "malloc: %s", pcap_strerror(errno)); |
| 180 | (void)close(fd); |
| 181 | return (-1); |
| 182 | } |
| 183 | |
| 184 | ifc.ifc_len = buf_size; |
| 185 | ifc.ifc_buf = buf; |
| 186 | memset(buf, 0, buf_size); |
| 187 | if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 |
| 188 | && errno != EINVAL) { |
| 189 | (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 190 | "SIOCGIFCONF: %s", pcap_strerror(errno)); |
| 191 | (void)close(fd); |
| 192 | free(buf); |
| 193 | return (-1); |
| 194 | } |
| 195 | if (ifc.ifc_len < buf_size && |
| 196 | (buf_size - ifc.ifc_len) > sizeof(ifrp->ifr_name) + MAX_SA_LEN) |
| 197 | break; |
| 198 | free(buf); |
| 199 | buf_size *= 2; |
| 200 | } |
| 201 | |
| 202 | ifrp = (struct ifreq *)buf; |
| 203 | ifend = (struct ifreq *)(buf + ifc.ifc_len); |
| 204 | |
| 205 | for (; ifrp < ifend; ifrp = ifnext) { |
| 206 | /* |
| 207 | * XXX - what if this isn't an IPv4 address? Can |
| 208 | * we still get the netmask, etc. with ioctls on |
| 209 | * an IPv4 socket? |
| 210 | * |
| 211 | * The answer is probably platform-dependent, and |
| 212 | * if the answer is "no" on more than one platform, |
| 213 | * the way you work around it is probably platform- |
| 214 | * dependent as well. |
| 215 | */ |
| 216 | n = SA_LEN(&ifrp->ifr_addr) + sizeof(ifrp->ifr_name); |
| 217 | if (n < sizeof(*ifrp)) |
| 218 | ifnext = ifrp + 1; |
| 219 | else |
| 220 | ifnext = (struct ifreq *)((char *)ifrp + n); |
| 221 | |
| 222 | /* |
| 223 | * XXX - The 32-bit compatibility layer for Linux on IA-64 |
| 224 | * is slightly broken. It correctly converts the structures |
| 225 | * to and from kernel land from 64 bit to 32 bit but |
| 226 | * doesn't update ifc.ifc_len, leaving it larger than the |
| 227 | * amount really used. This means we read off the end |
| 228 | * of the buffer and encounter an interface with an |
| 229 | * "empty" name. Since this is highly unlikely to ever |
| 230 | * occur in a valid case we can just finish looking for |
| 231 | * interfaces if we see an empty name. |
| 232 | */ |
| 233 | if (!(*ifrp->ifr_name)) |
| 234 | break; |
| 235 | |
| 236 | /* |
| 237 | * Skip entries that begin with "dummy". |
| 238 | * XXX - what are these? Is this Linux-specific? |
| 239 | * Are there platforms on which we shouldn't do this? |
| 240 | */ |
| 241 | if (strncmp(ifrp->ifr_name, "dummy", 5) == 0) |
| 242 | continue; |
| 243 | |
| 244 | /* |
| 245 | * Get the flags for this interface, and skip it if it's |
| 246 | * not up. |
| 247 | */ |
| 248 | strncpy(ifrflags.ifr_name, ifrp->ifr_name, |
| 249 | sizeof(ifrflags.ifr_name)); |
| 250 | if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifrflags) < 0) { |
| 251 | if (errno == ENXIO) |
| 252 | continue; |
| 253 | (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 254 | "SIOCGIFFLAGS: %.*s: %s", |
| 255 | (int)sizeof(ifrflags.ifr_name), |
| 256 | ifrflags.ifr_name, |
| 257 | pcap_strerror(errno)); |
| 258 | ret = -1; |
| 259 | break; |
| 260 | } |
| 261 | if (!(ifrflags.ifr_flags & IFF_UP)) |
| 262 | continue; |
| 263 | |
| 264 | /* |
| 265 | * Get the netmask for this address on this interface. |
| 266 | */ |
| 267 | strncpy(ifrnetmask.ifr_name, ifrp->ifr_name, |
| 268 | sizeof(ifrnetmask.ifr_name)); |
| 269 | memcpy(&ifrnetmask.ifr_addr, &ifrp->ifr_addr, |
| 270 | sizeof(ifrnetmask.ifr_addr)); |
| 271 | if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifrnetmask) < 0) { |
| 272 | if (errno == EADDRNOTAVAIL) { |
| 273 | /* |
| 274 | * Not available. |
| 275 | */ |
| 276 | netmask = NULL; |
| 277 | netmask_size = 0; |
| 278 | } else { |
| 279 | (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 280 | "SIOCGIFNETMASK: %.*s: %s", |
| 281 | (int)sizeof(ifrnetmask.ifr_name), |
| 282 | ifrnetmask.ifr_name, |
| 283 | pcap_strerror(errno)); |
| 284 | ret = -1; |
| 285 | break; |
| 286 | } |
| 287 | } else { |
| 288 | netmask = &ifrnetmask.ifr_addr; |
| 289 | netmask_size = SA_LEN(netmask); |
| 290 | } |
| 291 | |
| 292 | /* |
| 293 | * Get the broadcast address for this address on this |
| 294 | * interface (if any). |
| 295 | */ |
| 296 | if (ifrflags.ifr_flags & IFF_BROADCAST) { |
| 297 | strncpy(ifrbroadaddr.ifr_name, ifrp->ifr_name, |
| 298 | sizeof(ifrbroadaddr.ifr_name)); |
| 299 | memcpy(&ifrbroadaddr.ifr_addr, &ifrp->ifr_addr, |
| 300 | sizeof(ifrbroadaddr.ifr_addr)); |
| 301 | if (ioctl(fd, SIOCGIFBRDADDR, |
| 302 | (char *)&ifrbroadaddr) < 0) { |
| 303 | if (errno == EADDRNOTAVAIL) { |
| 304 | /* |
| 305 | * Not available. |
| 306 | */ |
| 307 | broadaddr = NULL; |
| 308 | broadaddr_size = 0; |
| 309 | } else { |
| 310 | (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 311 | "SIOCGIFBRDADDR: %.*s: %s", |
| 312 | (int)sizeof(ifrbroadaddr.ifr_name), |
| 313 | ifrbroadaddr.ifr_name, |
| 314 | pcap_strerror(errno)); |
| 315 | ret = -1; |
| 316 | break; |
| 317 | } |
| 318 | } else { |
| 319 | broadaddr = &ifrbroadaddr.ifr_broadaddr; |
| 320 | broadaddr_size = SA_LEN(broadaddr); |
| 321 | } |
| 322 | } else { |
| 323 | /* |
| 324 | * Not a broadcast interface, so no broadcast |
| 325 | * address. |
| 326 | */ |
| 327 | broadaddr = NULL; |
| 328 | broadaddr_size = 0; |
| 329 | } |
| 330 | |
| 331 | /* |
| 332 | * Get the destination address for this address on this |
| 333 | * interface (if any). |
| 334 | */ |
| 335 | if (ifrflags.ifr_flags & IFF_POINTOPOINT) { |
| 336 | strncpy(ifrdstaddr.ifr_name, ifrp->ifr_name, |
| 337 | sizeof(ifrdstaddr.ifr_name)); |
| 338 | memcpy(&ifrdstaddr.ifr_addr, &ifrp->ifr_addr, |
| 339 | sizeof(ifrdstaddr.ifr_addr)); |
| 340 | if (ioctl(fd, SIOCGIFDSTADDR, |
| 341 | (char *)&ifrdstaddr) < 0) { |
| 342 | if (errno == EADDRNOTAVAIL) { |
| 343 | /* |
| 344 | * Not available. |
| 345 | */ |
| 346 | dstaddr = NULL; |
| 347 | dstaddr_size = 0; |
| 348 | } else { |
| 349 | (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, |
| 350 | "SIOCGIFDSTADDR: %.*s: %s", |
| 351 | (int)sizeof(ifrdstaddr.ifr_name), |
| 352 | ifrdstaddr.ifr_name, |
| 353 | pcap_strerror(errno)); |
| 354 | ret = -1; |
| 355 | break; |
| 356 | } |
| 357 | } else { |
| 358 | dstaddr = &ifrdstaddr.ifr_dstaddr; |
| 359 | dstaddr_size = SA_LEN(dstaddr); |
| 360 | } |
| 361 | } else { |
| 362 | /* |
| 363 | * Not a point-to-point interface, so no destination |
| 364 | * address. |
| 365 | */ |
| 366 | dstaddr = NULL; |
| 367 | dstaddr_size = 0; |
| 368 | } |
| 369 | |
| 370 | #if defined (HAVE_SOLARIS) || defined (HAVE_HPUX10_20_OR_LATER) |
| 371 | /* |
| 372 | * If this entry has a colon followed by a number at |
| 373 | * the end, it's a logical interface. Those are just |
| 374 | * the way you assign multiple IP addresses to a real |
| 375 | * interface, so an entry for a logical interface should |
| 376 | * be treated like the entry for the real interface; |
| 377 | * we do that by stripping off the ":" and the number. |
| 378 | */ |
| 379 | p = strchr(ifrp->ifr_name, ':'); |
| 380 | if (p != NULL) { |
| 381 | /* |
| 382 | * We have a ":"; is it followed by a number? |
| 383 | */ |
| 384 | q = p + 1; |
| 385 | while (isdigit((unsigned char)*q)) |
| 386 | q++; |
| 387 | if (*q == '\0') { |
| 388 | /* |
| 389 | * All digits after the ":" until the end. |
| 390 | * Strip off the ":" and everything after |
| 391 | * it. |
| 392 | */ |
| 393 | *p = '\0'; |
| 394 | } |
| 395 | } |
| 396 | #endif |
| 397 | |
| 398 | /* |
| 399 | * Add information for this address to the list. |
| 400 | */ |
| 401 | if (add_addr_to_iflist(&devlist, ifrp->ifr_name, |
| 402 | ifrflags.ifr_flags, &ifrp->ifr_addr, |
| 403 | SA_LEN(&ifrp->ifr_addr), netmask, netmask_size, |
| 404 | broadaddr, broadaddr_size, dstaddr, dstaddr_size, |
| 405 | errbuf) < 0) { |
| 406 | ret = -1; |
| 407 | break; |
| 408 | } |
| 409 | } |
| 410 | free(buf); |
The Android Open Source Project | 478ab6c | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 411 | (void)close(fd); |
| 412 | |
The Android Open Source Project | 478ab6c | 2009-03-03 19:30:05 -0800 | [diff] [blame] | 413 | if (ret == -1) { |
| 414 | /* |
| 415 | * We had an error; free the list we've been constructing. |
| 416 | */ |
| 417 | if (devlist != NULL) { |
| 418 | pcap_freealldevs(devlist); |
| 419 | devlist = NULL; |
| 420 | } |
| 421 | } |
| 422 | |
| 423 | *alldevsp = devlist; |
| 424 | return (ret); |
| 425 | } |