1 /* $FreeBSD: src/lib/libc/net/getifaddrs.c,v 1.1.2.4 2002/08/01 19:31:06 ume Exp $ */ 2 /* $DragonFly: src/lib/libc/net/getifaddrs.c,v 1.5 2005/01/31 22:29:33 dillon Exp $ */ 3 /* $KAME: getifaddrs.c,v 1.9 2001/08/20 02:31:20 itojun Exp $ */ 4 5 /* 6 * Copyright (c) 1995, 1999 7 * Berkeley Software Design, Inc. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * BSDI getifaddrs.c,v 2.12 2000/02/23 14:51:59 dab Exp 28 */ 29 /* 30 * NOTE: SIOCGIFCONF case is not LP64 friendly. it also does not perform 31 * try-and-error for region size. 32 */ 33 #include "namespace.h" 34 #include <sys/types.h> 35 #include <sys/ioctl.h> 36 #include <sys/socket.h> 37 #include <net/if.h> 38 #ifdef NET_RT_IFLIST 39 #include <sys/param.h> 40 #include <net/route.h> 41 #include <sys/sysctl.h> 42 #include <net/if_dl.h> 43 #endif 44 45 #include <errno.h> 46 #include <ifaddrs.h> 47 #include <stdlib.h> 48 #include <string.h> 49 #include "un-namespace.h" 50 51 #if !defined(AF_LINK) 52 #define SA_LEN(sa) sizeof(struct sockaddr) 53 #endif 54 55 #if !defined(SA_LEN) 56 #define SA_LEN(sa) (sa)->sa_len 57 #endif 58 59 #define SALIGN (sizeof(long) - 1) 60 #define SA_RLEN(sa) ((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1)) 61 62 #ifndef ALIGNBYTES 63 /* 64 * On systems with a routing socket, ALIGNBYTES should match the value 65 * that the kernel uses when building the messages. 66 */ 67 #define ALIGNBYTES XXX 68 #endif 69 #ifndef ALIGN 70 #define ALIGN(p) (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES) 71 #endif 72 73 #if _BSDI_VERSION >= 199701 74 #define HAVE_IFM_DATA 75 #endif 76 77 #if _BSDI_VERSION >= 199802 78 /* ifam_data is very specific to recent versions of bsdi */ 79 #define HAVE_IFAM_DATA 80 #endif 81 82 #if defined(__NetBSD__) || defined(__OpenBSD__) || \ 83 defined(__FreeBSD__) || defined(__DragonFly__) 84 #define HAVE_IFM_DATA 85 #endif 86 87 #define MAX_SYSCTL_TRY 5 88 89 int 90 getifaddrs(struct ifaddrs **pif) 91 { 92 int icnt = 1; 93 int dcnt = 0; 94 int ncnt = 0; 95 #ifdef NET_RT_IFLIST 96 int ntry = 0; 97 int mib[6]; 98 size_t needed; 99 char *buf; 100 char *next; 101 struct ifaddrs *cif = 0; 102 char *p, *p0; 103 struct rt_msghdr *rtm; 104 struct if_msghdr *ifm; 105 struct ifa_msghdr *ifam; 106 struct sockaddr_dl *dl; 107 struct sockaddr *sa; 108 struct ifaddrs *ifa, *ift; 109 u_short idx = 0; 110 #else /* NET_RT_IFLIST */ 111 char buf[1024]; 112 int m, sock; 113 struct ifconf ifc; 114 struct ifreq *ifr; 115 struct ifreq *lifr; 116 #endif /* NET_RT_IFLIST */ 117 int i; 118 size_t len, alen; 119 char *data; 120 char *names; 121 122 #ifdef NET_RT_IFLIST 123 mib[0] = CTL_NET; 124 mib[1] = PF_ROUTE; 125 mib[2] = 0; /* protocol */ 126 mib[3] = 0; /* wildcard address family */ 127 mib[4] = NET_RT_IFLIST; 128 mib[5] = 0; /* no flags */ 129 do { 130 /* 131 * We'll try to get addresses several times in case that 132 * the number of addresses is unexpectedly increased during 133 * the two sysctl calls. This should rarely happen, but we'll 134 * try to do our best for applications that assume success of 135 * this library (which should usually be the case). 136 * Portability note: since FreeBSD does not add margin of 137 * memory at the first sysctl, the possibility of failure on 138 * the second sysctl call is a bit higher. 139 */ 140 141 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 142 return (-1); 143 if ((buf = malloc(needed)) == NULL) 144 return (-1); 145 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 146 if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) { 147 free(buf); 148 return (-1); 149 } 150 free(buf); 151 buf = NULL; 152 } 153 } while (buf == NULL); 154 155 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 156 rtm = (struct rt_msghdr *)(void *)next; 157 if (rtm->rtm_version != RTM_VERSION) 158 continue; 159 switch (rtm->rtm_type) { 160 case RTM_IFINFO: 161 ifm = (struct if_msghdr *)(void *)rtm; 162 if (ifm->ifm_addrs & RTA_IFP) { 163 idx = ifm->ifm_index; 164 ++icnt; 165 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 166 dcnt += SA_RLEN((struct sockaddr *)(void*)dl) + 167 ALIGNBYTES; 168 #ifdef HAVE_IFM_DATA 169 dcnt += sizeof(ifm->ifm_data); 170 #endif /* HAVE_IFM_DATA */ 171 ncnt += dl->sdl_nlen + 1; 172 } else 173 idx = 0; 174 break; 175 176 case RTM_NEWADDR: 177 ifam = (struct ifa_msghdr *)(void *)rtm; 178 if (idx && ifam->ifam_index != idx) 179 abort(); /* this cannot happen */ 180 181 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) 182 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 183 break; 184 p = (char *)(void *)(ifam + 1); 185 ++icnt; 186 #ifdef HAVE_IFAM_DATA 187 dcnt += sizeof(ifam->ifam_data) + ALIGNBYTES; 188 #endif /* HAVE_IFAM_DATA */ 189 /* Scan to look for length of address */ 190 alen = 0; 191 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 192 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 193 == 0) 194 continue; 195 sa = (struct sockaddr *)(void *)p; 196 len = SA_RLEN(sa); 197 if (i == RTAX_IFA) { 198 alen = len; 199 break; 200 } 201 p += len; 202 } 203 for (p = p0, i = 0; i < RTAX_MAX; i++) { 204 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 205 == 0) 206 continue; 207 sa = (struct sockaddr *)(void *)p; 208 len = SA_RLEN(sa); 209 if (i == RTAX_NETMASK && SA_LEN(sa) == 0) 210 dcnt += alen; 211 else 212 dcnt += len; 213 p += len; 214 } 215 break; 216 } 217 } 218 #else /* NET_RT_IFLIST */ 219 ifc.ifc_buf = buf; 220 ifc.ifc_len = sizeof(buf); 221 222 if ((sock = _socket(AF_INET, SOCK_STREAM, 0)) < 0) 223 return (-1); 224 i = _ioctl(sock, SIOCGIFCONF, (char *)&ifc); 225 _close(sock); 226 if (i < 0) 227 return (-1); 228 229 ifr = ifc.ifc_req; 230 lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len]; 231 232 while (ifr < lifr) { 233 struct sockaddr *sa; 234 235 sa = &ifr->ifr_addr; 236 ++icnt; 237 dcnt += SA_RLEN(sa); 238 ncnt += sizeof(ifr->ifr_name) + 1; 239 240 if (SA_LEN(sa) < sizeof(*sa)) 241 ifr = (struct ifreq *)(((char *)sa) + sizeof(*sa)); 242 else 243 ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa)); 244 } 245 #endif /* NET_RT_IFLIST */ 246 247 if (icnt + dcnt + ncnt == 1) { 248 *pif = NULL; 249 free(buf); 250 return (0); 251 } 252 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt); 253 if (data == NULL) { 254 free(buf); 255 return(-1); 256 } 257 258 ifa = (struct ifaddrs *)(void *)data; 259 data += sizeof(struct ifaddrs) * icnt; 260 names = data + dcnt; 261 262 memset(ifa, 0, sizeof(struct ifaddrs) * icnt); 263 ift = ifa; 264 265 #ifdef NET_RT_IFLIST 266 idx = 0; 267 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 268 rtm = (struct rt_msghdr *)(void *)next; 269 if (rtm->rtm_version != RTM_VERSION) 270 continue; 271 switch (rtm->rtm_type) { 272 case RTM_IFINFO: 273 ifm = (struct if_msghdr *)(void *)rtm; 274 if (ifm->ifm_addrs & RTA_IFP) { 275 idx = ifm->ifm_index; 276 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 277 278 cif = ift; 279 ift->ifa_name = names; 280 ift->ifa_flags = (int)ifm->ifm_flags; 281 memcpy(names, dl->sdl_data, 282 (size_t)dl->sdl_nlen); 283 names[dl->sdl_nlen] = 0; 284 names += dl->sdl_nlen + 1; 285 286 ift->ifa_addr = (struct sockaddr *)(void *)data; 287 memcpy(data, dl, 288 (size_t)SA_LEN((struct sockaddr *) 289 (void *)dl)); 290 data += SA_RLEN((struct sockaddr *)(void *)dl); 291 292 #ifdef HAVE_IFM_DATA 293 /* ifm_data needs to be aligned */ 294 ift->ifa_data = data = (void *)ALIGN(data); 295 memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data)); 296 data += sizeof(ifm->ifm_data); 297 #else /* HAVE_IFM_DATA */ 298 ift->ifa_data = NULL; 299 #endif /* HAVE_IFM_DATA */ 300 301 ift = (ift->ifa_next = ift + 1); 302 } else 303 idx = 0; 304 break; 305 306 case RTM_NEWADDR: 307 ifam = (struct ifa_msghdr *)(void *)rtm; 308 if (idx && ifam->ifam_index != idx) 309 abort(); /* this cannot happen */ 310 311 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 312 break; 313 ift->ifa_name = cif->ifa_name; 314 ift->ifa_flags = cif->ifa_flags; 315 ift->ifa_data = NULL; 316 p = (char *)(void *)(ifam + 1); 317 /* Scan to look for length of address */ 318 alen = 0; 319 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 320 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 321 == 0) 322 continue; 323 sa = (struct sockaddr *)(void *)p; 324 len = SA_RLEN(sa); 325 if (i == RTAX_IFA) { 326 alen = len; 327 break; 328 } 329 p += len; 330 } 331 for (p = p0, i = 0; i < RTAX_MAX; i++) { 332 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 333 == 0) 334 continue; 335 sa = (struct sockaddr *)(void *)p; 336 len = SA_RLEN(sa); 337 switch (i) { 338 case RTAX_IFA: 339 ift->ifa_addr = 340 (struct sockaddr *)(void *)data; 341 memcpy(data, p, len); 342 data += len; 343 break; 344 345 case RTAX_NETMASK: 346 ift->ifa_netmask = 347 (struct sockaddr *)(void *)data; 348 if (SA_LEN(sa) == 0) { 349 memset(data, 0, alen); 350 data += alen; 351 break; 352 } 353 memcpy(data, p, len); 354 data += len; 355 break; 356 357 case RTAX_BRD: 358 ift->ifa_broadaddr = 359 (struct sockaddr *)(void *)data; 360 memcpy(data, p, len); 361 data += len; 362 break; 363 } 364 p += len; 365 } 366 367 #ifdef HAVE_IFAM_DATA 368 /* ifam_data needs to be aligned */ 369 ift->ifa_data = data = (void *)ALIGN(data); 370 memcpy(data, &ifam->ifam_data, sizeof(ifam->ifam_data)); 371 data += sizeof(ifam->ifam_data); 372 #endif /* HAVE_IFAM_DATA */ 373 374 ift = (ift->ifa_next = ift + 1); 375 break; 376 } 377 } 378 379 free(buf); 380 #else /* NET_RT_IFLIST */ 381 ifr = ifc.ifc_req; 382 lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len]; 383 384 while (ifr < lifr) { 385 struct sockaddr *sa; 386 387 ift->ifa_name = names; 388 names[sizeof(ifr->ifr_name)] = 0; 389 strncpy(names, ifr->ifr_name, sizeof(ifr->ifr_name)); 390 while (*names++) 391 ; 392 393 ift->ifa_addr = (struct sockaddr *)data; 394 sa = &ifr->ifr_addr; 395 memcpy(data, sa, SA_LEN(sa)); 396 data += SA_RLEN(sa); 397 398 ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa)); 399 ift = (ift->ifa_next = ift + 1); 400 } 401 #endif /* NET_RT_IFLIST */ 402 if (--ift >= ifa) { 403 ift->ifa_next = NULL; 404 *pif = ifa; 405 } else { 406 *pif = NULL; 407 free(ifa); 408 } 409 return (0); 410 } 411 412 void 413 freeifaddrs(struct ifaddrs *ifp) 414 { 415 416 free(ifp); 417 } 418