1 /* $NetBSD: getifaddrs.c,v 1.6 2000/10/27 15:48:49 itojun 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 1.6 2000/10/27 15:48:49 itojun 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 /* ifam_data is very specific to recent versions of bsdi */ 83 #define HAVE_IFAM_DATA 84 #endif 85 86 #if defined(__NetBSD__) || defined(__OpenBSD__) || defined(__FreeBSD__) 87 #define HAVE_IFM_DATA 88 #endif 89 90 int 91 getifaddrs(struct ifaddrs **pif) 92 { 93 int icnt = 1; 94 int dcnt = 0; 95 int ncnt = 0; 96 #ifdef NET_RT_IFLIST 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 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 130 return (-1); 131 if ((buf = malloc(needed)) == NULL) 132 return (-1); 133 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 134 free(buf); 135 return (-1); 136 } 137 138 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 139 rtm = (struct rt_msghdr *)(void *)next; 140 if (rtm->rtm_version != RTM_VERSION) 141 continue; 142 switch (rtm->rtm_type) { 143 case RTM_IFINFO: 144 ifm = (struct if_msghdr *)(void *)rtm; 145 if (ifm->ifm_addrs & RTA_IFP) { 146 idx = ifm->ifm_index; 147 ++icnt; 148 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 149 dcnt += SA_RLEN((struct sockaddr *)(void*)dl) + 150 ALIGNBYTES; 151 #ifdef HAVE_IFM_DATA 152 dcnt += sizeof(ifm->ifm_data); 153 #endif /* HAVE_IFM_DATA */ 154 ncnt += dl->sdl_nlen + 1; 155 } else 156 idx = 0; 157 break; 158 159 case RTM_NEWADDR: 160 ifam = (struct ifa_msghdr *)(void *)rtm; 161 if (idx && ifam->ifam_index != idx) 162 abort(); /* this cannot happen */ 163 164 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) 165 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 166 break; 167 p = (char *)(void *)(ifam + 1); 168 ++icnt; 169 #ifdef HAVE_IFAM_DATA 170 dcnt += sizeof(ifam->ifam_data) + ALIGNBYTES; 171 #endif /* HAVE_IFAM_DATA */ 172 /* Scan to look for length of address */ 173 alen = 0; 174 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 175 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 176 == 0) 177 continue; 178 sa = (struct sockaddr *)(void *)p; 179 len = SA_RLEN(sa); 180 if (i == RTAX_IFA) { 181 alen = len; 182 break; 183 } 184 p += len; 185 } 186 for (p = p0, i = 0; i < RTAX_MAX; i++) { 187 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 188 == 0) 189 continue; 190 sa = (struct sockaddr *)(void *)p; 191 len = SA_RLEN(sa); 192 if (i == RTAX_NETMASK && SA_LEN(sa) == 0) 193 dcnt += alen; 194 else 195 dcnt += len; 196 p += len; 197 } 198 break; 199 } 200 } 201 #else /* NET_RT_IFLIST */ 202 ifc.ifc_buf = buf; 203 ifc.ifc_len = sizeof(buf); 204 205 if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) 206 return (-1); 207 i = ioctl(sock, SIOCGIFCONF, (char *)&ifc); 208 close(sock); 209 if (i < 0) 210 return (-1); 211 212 ifr = ifc.ifc_req; 213 lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len]; 214 215 while (ifr < lifr) { 216 struct sockaddr *sa; 217 218 sa = &ifr->ifr_addr; 219 ++icnt; 220 dcnt += SA_RLEN(sa); 221 ncnt += sizeof(ifr->ifr_name) + 1; 222 223 ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa)); 224 } 225 #endif /* NET_RT_IFLIST */ 226 227 if (icnt + dcnt + ncnt == 1) { 228 *pif = NULL; 229 free(buf); 230 return (0); 231 } 232 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt); 233 if (data == NULL) { 234 free(buf); 235 return(-1); 236 } 237 238 ifa = (struct ifaddrs *)(void *)data; 239 data += sizeof(struct ifaddrs) * icnt; 240 names = data + dcnt; 241 242 memset(ifa, 0, sizeof(struct ifaddrs) * icnt); 243 ift = ifa; 244 245 #ifdef NET_RT_IFLIST 246 idx = 0; 247 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 248 rtm = (struct rt_msghdr *)(void *)next; 249 if (rtm->rtm_version != RTM_VERSION) 250 continue; 251 switch (rtm->rtm_type) { 252 case RTM_IFINFO: 253 ifm = (struct if_msghdr *)(void *)rtm; 254 if (ifm->ifm_addrs & RTA_IFP) { 255 idx = ifm->ifm_index; 256 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 257 258 cif = ift; 259 ift->ifa_name = names; 260 ift->ifa_flags = (int)ifm->ifm_flags; 261 memcpy(names, dl->sdl_data, 262 (size_t)dl->sdl_nlen); 263 names[dl->sdl_nlen] = 0; 264 names += dl->sdl_nlen + 1; 265 266 ift->ifa_addr = (struct sockaddr *)(void *)data; 267 memcpy(data, dl, 268 (size_t)SA_LEN((struct sockaddr *) 269 (void *)dl)); 270 data += SA_RLEN((struct sockaddr *)(void *)dl); 271 272 #ifdef HAVE_IFM_DATA 273 /* ifm_data needs to be aligned */ 274 ift->ifa_data = data = (void *)ALIGN(data); 275 memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data)); 276 data += sizeof(ifm->ifm_data); 277 #else /* HAVE_IFM_DATA */ 278 ift->ifa_data = NULL; 279 #endif /* HAVE_IFM_DATA */ 280 281 ift = (ift->ifa_next = ift + 1); 282 } else 283 idx = 0; 284 break; 285 286 case RTM_NEWADDR: 287 ifam = (struct ifa_msghdr *)(void *)rtm; 288 if (idx && ifam->ifam_index != idx) 289 abort(); /* this cannot happen */ 290 291 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 292 break; 293 ift->ifa_name = cif->ifa_name; 294 ift->ifa_flags = cif->ifa_flags; 295 ift->ifa_data = NULL; 296 p = (char *)(void *)(ifam + 1); 297 /* Scan to look for length of address */ 298 alen = 0; 299 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 300 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 301 == 0) 302 continue; 303 sa = (struct sockaddr *)(void *)p; 304 len = SA_RLEN(sa); 305 if (i == RTAX_IFA) { 306 alen = len; 307 break; 308 } 309 p += len; 310 } 311 for (p = p0, i = 0; i < RTAX_MAX; i++) { 312 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 313 == 0) 314 continue; 315 sa = (struct sockaddr *)(void *)p; 316 len = SA_RLEN(sa); 317 switch (i) { 318 case RTAX_IFA: 319 ift->ifa_addr = 320 (struct sockaddr *)(void *)data; 321 memcpy(data, p, len); 322 data += len; 323 break; 324 325 case RTAX_NETMASK: 326 ift->ifa_netmask = 327 (struct sockaddr *)(void *)data; 328 if (SA_LEN(sa) == 0) { 329 memset(data, 0, alen); 330 data += alen; 331 break; 332 } 333 memcpy(data, p, len); 334 data += len; 335 break; 336 337 case RTAX_BRD: 338 ift->ifa_broadaddr = 339 (struct sockaddr *)(void *)data; 340 memcpy(data, p, len); 341 data += len; 342 break; 343 } 344 p += len; 345 } 346 347 #ifdef HAVE_IFAM_DATA 348 /* ifam_data needs to be aligned */ 349 ift->ifa_data = data = (void *)ALIGN(data); 350 memcpy(data, &ifam->ifam_data, sizeof(ifam->ifam_data)); 351 data += sizeof(ifam->ifam_data); 352 #endif /* HAVE_IFAM_DATA */ 353 354 ift = (ift->ifa_next = ift + 1); 355 break; 356 } 357 } 358 359 free(buf); 360 #else /* NET_RT_IFLIST */ 361 ifr = ifc.ifc_req; 362 lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len]; 363 364 while (ifr < lifr) { 365 struct sockaddr *sa; 366 367 ift->ifa_name = names; 368 names[sizeof(ifr->ifr_name)] = 0; 369 strncpy(names, ifr->ifr_name, sizeof(ifr->ifr_name)); 370 while (*names++) 371 ; 372 373 ift->ifa_addr = (struct sockaddr *)data; 374 sa = &ifr->ifr_addr; 375 memcpy(data, sa, SA_LEN(sa)); 376 data += SA_RLEN(sa); 377 378 ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa)); 379 ift = (ift->ifa_next = ift + 1); 380 } 381 #endif /* NET_RT_IFLIST */ 382 if (--ift >= ifa) { 383 ift->ifa_next = NULL; 384 *pif = ifa; 385 } else { 386 *pif = NULL; 387 free(ifa); 388 } 389 return (0); 390 } 391 392 void 393 freeifaddrs(struct ifaddrs *ifp) 394 { 395 free(ifp); 396 } 397