getifaddrs.c revision 1.5
1/* $NetBSD: getifaddrs.c,v 1.5 2000/07/06 02:53:12 christos Exp $ */ 2 3/* 4 * Copyright (c) 1995, 1999 5 * Berkeley Software Design, Inc. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23 * SUCH DAMAGE. 24 * 25 * BSDI getifaddrs.c,v 2.12 2000/02/23 14:51:59 dab Exp 26 */ 27 28#include <sys/cdefs.h> 29#if defined(LIBC_SCCS) && !defined(lint) 30__RCSID("$NetBSD: getifaddrs.c,v 1.5 2000/07/06 02:53:12 christos Exp $"); 31#endif /* LIBC_SCCS and not lint */ 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 50#ifdef __weak_alias 51__weak_alias(getifaddrs,_getifaddrs) 52__weak_alias(freeifaddrs,_freeifaddrs) 53#endif 54 55#if !defined(AF_LINK) 56#define SA_LEN(sa) sizeof(struct sockaddr) 57#endif 58 59#if !defined(SA_LEN) 60#define SA_LEN(sa) (sa)->sa_len 61#endif 62 63#define SALIGN (sizeof(long) - 1) 64#define SA_RLEN(sa) ((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1)) 65 66#ifndef ALIGNBYTES 67/* 68 * On systems with a routing socket, ALIGNBYTES should match the value 69 * that the kernel uses when building the messages. 70 */ 71#define ALIGNBYTES XXX 72#endif 73#ifndef ALIGN 74#define ALIGN(p) (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES) 75#endif 76 77#if _BSDI_VERSION >= 199701 78#define HAVE_IFM_DATA 79#endif 80 81#if _BSDI_VERSION >= 199802 82#define HAVE_IFAM_DATA 83#endif 84 85int 86getifaddrs(struct ifaddrs **pif) 87{ 88 int icnt = 1; 89 int dcnt = 0; 90 int ncnt = 0; 91#ifdef NET_RT_IFLIST 92 int mib[6]; 93 size_t needed; 94 char *buf; 95 char *next; 96 struct ifaddrs *cif = 0; 97 char *p, *p0; 98 struct rt_msghdr *rtm; 99 struct if_msghdr *ifm; 100 struct ifa_msghdr *ifam; 101 struct sockaddr_dl *dl; 102 struct sockaddr *sa; 103 struct ifaddrs *ifa, *ift; 104 u_short idx = 0; 105#else /* NET_RT_IFLIST */ 106 char buf[1024]; 107 int m, sock; 108 struct ifconf ifc; 109 struct ifreq *ifr; 110 struct ifreq *lifr; 111#endif /* NET_RT_IFLIST */ 112 int i; 113 size_t len, alen; 114 char *data; 115 char *names; 116 117#ifdef NET_RT_IFLIST 118 mib[0] = CTL_NET; 119 mib[1] = PF_ROUTE; 120 mib[2] = 0; /* protocol */ 121 mib[3] = 0; /* wildcard address family */ 122 mib[4] = NET_RT_IFLIST; 123 mib[5] = 0; /* no flags */ 124 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 125 return (-1); 126 if ((buf = malloc(needed)) == NULL) 127 return (-1); 128 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 129 free(buf); 130 return (-1); 131 } 132 133 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 134 rtm = (struct rt_msghdr *)(void *)next; 135 if (rtm->rtm_version != RTM_VERSION) 136 continue; 137 switch (rtm->rtm_type) { 138 case RTM_IFINFO: 139 ifm = (struct if_msghdr *)(void *)rtm; 140 if (ifm->ifm_addrs & RTA_IFP) { 141 idx = ifm->ifm_index; 142 ++icnt; 143 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 144 dcnt += SA_RLEN((struct sockaddr *)(void*)dl) + 145 ALIGNBYTES; 146#ifdef HAVE_IFM_DATA 147 dcnt += sizeof(ifm->ifm_data); 148#endif /* HAVE_IFM_DATA */ 149 ncnt += dl->sdl_nlen + 1; 150 } else 151 idx = 0; 152 break; 153 154 case RTM_NEWADDR: 155 ifam = (struct ifa_msghdr *)(void *)rtm; 156 if (idx && ifam->ifam_index != idx) 157 abort(); /* this cannot happen */ 158 159#define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) 160 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 161 break; 162 p = (char *)(void *)(ifam + 1); 163 ++icnt; 164#ifdef HAVE_IFAM_DATA 165 dcnt += sizeof(ifam->ifam_data) + ALIGNBYTES; 166#endif /* HAVE_IFAM_DATA */ 167 /* Scan to look for length of address */ 168 alen = 0; 169 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 170 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 171 == 0) 172 continue; 173 sa = (struct sockaddr *)(void *)p; 174 len = SA_RLEN(sa); 175 if (i == RTAX_IFA) { 176 alen = len; 177 break; 178 } 179 p += len; 180 } 181 for (p = p0, i = 0; i < RTAX_MAX; i++) { 182 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 183 == 0) 184 continue; 185 sa = (struct sockaddr *)(void *)p; 186 len = SA_RLEN(sa); 187 if (i == RTAX_NETMASK && SA_LEN(sa) == 0) 188 dcnt += alen; 189 else 190 dcnt += len; 191 p += len; 192 } 193 break; 194 } 195 } 196#else /* NET_RT_IFLIST */ 197 ifc.ifc_buf = buf; 198 ifc.ifc_len = sizeof(buf); 199 200 if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) 201 return (-1); 202 i = ioctl(sock, SIOCGIFCONF, (char *)&ifc); 203 close(sock); 204 if (i < 0) 205 return (-1); 206 207 ifr = ifc.ifc_req; 208 lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len]; 209 210 while (ifr < lifr) { 211 struct sockaddr *sa; 212 213 sa = &ifr->ifr_addr; 214 ++icnt; 215 dcnt += SA_RLEN(sa); 216 ncnt += sizeof(ifr->ifr_name) + 1; 217 218 ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa)); 219 } 220#endif /* NET_RT_IFLIST */ 221 222 if (icnt + dcnt + ncnt == 1) { 223 *pif = NULL; 224 free(buf); 225 return (0); 226 } 227 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt); 228 if (data == NULL) { 229 free(buf); 230 return(-1); 231 } 232 233 ifa = (struct ifaddrs *)(void *)data; 234 data += sizeof(struct ifaddrs) * icnt; 235 names = data + dcnt; 236 237 memset(ifa, 0, sizeof(struct ifaddrs) * icnt); 238 ift = ifa; 239 240#ifdef NET_RT_IFLIST 241 idx = 0; 242 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 243 rtm = (struct rt_msghdr *)(void *)next; 244 if (rtm->rtm_version != RTM_VERSION) 245 continue; 246 switch (rtm->rtm_type) { 247 case RTM_IFINFO: 248 ifm = (struct if_msghdr *)(void *)rtm; 249 if (ifm->ifm_addrs & RTA_IFP) { 250 idx = ifm->ifm_index; 251 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 252 253 cif = ift; 254 ift->ifa_name = names; 255 ift->ifa_flags = (int)ifm->ifm_flags; 256 memcpy(names, dl->sdl_data, 257 (size_t)dl->sdl_nlen); 258 names[dl->sdl_nlen] = 0; 259 names += dl->sdl_nlen + 1; 260 261 ift->ifa_addr = (struct sockaddr *)(void *)data; 262 memcpy(data, dl, 263 (size_t)SA_LEN((struct sockaddr *) 264 (void *)dl)); 265 data += SA_RLEN((struct sockaddr *)(void *)dl); 266 267#ifdef HAVE_IFM_DATA 268 /* ifm_data needs to be aligned */ 269 ift->ifa_data = data = (void *)ALIGN(data); 270 memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data)); 271 data += sizeof(ifm->ifm_data); 272#else /* HAVE_IFM_DATA */ 273 ift->ifa_data = NULL; 274#endif /* HAVE_IFM_DATA */ 275 276 ift = (ift->ifa_next = ift + 1); 277 } else 278 idx = 0; 279 break; 280 281 case RTM_NEWADDR: 282 ifam = (struct ifa_msghdr *)(void *)rtm; 283 if (idx && ifam->ifam_index != idx) 284 abort(); /* this cannot happen */ 285 286 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 287 break; 288 ift->ifa_name = cif->ifa_name; 289 ift->ifa_flags = cif->ifa_flags; 290 ift->ifa_data = NULL; 291 p = (char *)(void *)(ifam + 1); 292 /* Scan to look for length of address */ 293 alen = 0; 294 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 295 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 296 == 0) 297 continue; 298 sa = (struct sockaddr *)(void *)p; 299 len = SA_RLEN(sa); 300 if (i == RTAX_IFA) { 301 alen = len; 302 break; 303 } 304 p += len; 305 } 306 for (p = p0, i = 0; i < RTAX_MAX; i++) { 307 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 308 == 0) 309 continue; 310 sa = (struct sockaddr *)(void *)p; 311 len = SA_RLEN(sa); 312 switch (i) { 313 case RTAX_IFA: 314 ift->ifa_addr = 315 (struct sockaddr *)(void *)data; 316 memcpy(data, p, len); 317 data += len; 318 break; 319 320 case RTAX_NETMASK: 321 ift->ifa_netmask = 322 (struct sockaddr *)(void *)data; 323 if (SA_LEN(sa) == 0) { 324 memset(data, 0, alen); 325 data += alen; 326 break; 327 } 328 memcpy(data, p, len); 329 data += len; 330 break; 331 332 case RTAX_BRD: 333 ift->ifa_broadaddr = 334 (struct sockaddr *)(void *)data; 335 memcpy(data, p, len); 336 data += len; 337 break; 338 } 339 p += len; 340 } 341 342#ifdef HAVE_IFAM_DATA 343 /* ifam_data needs to be aligned */ 344 ift->ifa_data = data = (void *)ALIGN(data); 345 memcpy(data, &ifam->ifam_data, sizeof(ifam->ifam_data)); 346 data += sizeof(ifam->ifam_data); 347#endif /* HAVE_IFAM_DATA */ 348 349 ift = (ift->ifa_next = ift + 1); 350 break; 351 } 352 } 353 354 free(buf); 355#else /* NET_RT_IFLIST */ 356 ifr = ifc.ifc_req; 357 lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len]; 358 359 while (ifr < lifr) { 360 struct sockaddr *sa; 361 362 ift->ifa_name = names; 363 names[sizeof(ifr->ifr_name)] = 0; 364 strncpy(names, ifr->ifr_name, sizeof(ifr->ifr_name)); 365 while (*names++) 366 ; 367 368 ift->ifa_addr = (struct sockaddr *)data; 369 sa = &ifr->ifr_addr; 370 memcpy(data, sa, SA_LEN(sa)); 371 data += SA_RLEN(sa); 372 373 ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa)); 374 ift = (ift->ifa_next = ift + 1); 375 } 376#endif /* NET_RT_IFLIST */ 377 if (--ift >= ifa) { 378 ift->ifa_next = NULL; 379 *pif = ifa; 380 } else { 381 *pif = NULL; 382 free(ifa); 383 } 384 return (0); 385} 386 387void 388freeifaddrs(struct ifaddrs *ifp) 389{ 390 free(ifp); 391} 392