1 /* $NetBSD: getifaddrs.c,v 1.7 2001/01/04 03:57:58 lukem 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 1.7 2001/01/04 03:57:58 lukem 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 <assert.h> 46 #include <errno.h> 47 #include <ifaddrs.h> 48 #include <stdlib.h> 49 #include <string.h> 50 51 #ifdef __weak_alias 52 __weak_alias(getifaddrs,_getifaddrs) 53 __weak_alias(freeifaddrs,_freeifaddrs) 54 #endif 55 56 #if !defined(AF_LINK) 57 #define SA_LEN(sa) sizeof(struct sockaddr) 58 #endif 59 60 #if !defined(SA_LEN) 61 #define SA_LEN(sa) (sa)->sa_len 62 #endif 63 64 #define SALIGN (sizeof(long) - 1) 65 #define SA_RLEN(sa) ((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1)) 66 67 #ifndef ALIGNBYTES 68 /* 69 * On systems with a routing socket, ALIGNBYTES should match the value 70 * that the kernel uses when building the messages. 71 */ 72 #define ALIGNBYTES XXX 73 #endif 74 #ifndef ALIGN 75 #define ALIGN(p) (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES) 76 #endif 77 78 #if _BSDI_VERSION >= 199701 79 #define HAVE_IFM_DATA 80 #endif 81 82 #if _BSDI_VERSION >= 199802 83 /* ifam_data is very specific to recent versions of bsdi */ 84 #define HAVE_IFAM_DATA 85 #endif 86 87 #if defined(__NetBSD__) || defined(__OpenBSD__) || defined(__FreeBSD__) 88 #define HAVE_IFM_DATA 89 #endif 90 91 int 92 getifaddrs(struct ifaddrs **pif) 93 { 94 int icnt = 1; 95 int dcnt = 0; 96 int ncnt = 0; 97 #ifdef NET_RT_IFLIST 98 int mib[6]; 99 size_t needed; 100 char *buf; 101 char *next; 102 struct ifaddrs *cif = 0; 103 char *p, *p0; 104 struct rt_msghdr *rtm; 105 struct if_msghdr *ifm; 106 struct ifa_msghdr *ifam; 107 struct sockaddr_dl *dl; 108 struct sockaddr *sa; 109 struct ifaddrs *ifa, *ift; 110 u_short idx = 0; 111 #else /* NET_RT_IFLIST */ 112 char buf[1024]; 113 int m, sock; 114 struct ifconf ifc; 115 struct ifreq *ifr; 116 struct ifreq *lifr; 117 #endif /* NET_RT_IFLIST */ 118 int i; 119 size_t len, alen; 120 char *data; 121 char *names; 122 123 _DIAGASSERT(pif != NULL); 124 125 #ifdef NET_RT_IFLIST 126 mib[0] = CTL_NET; 127 mib[1] = PF_ROUTE; 128 mib[2] = 0; /* protocol */ 129 mib[3] = 0; /* wildcard address family */ 130 mib[4] = NET_RT_IFLIST; 131 mib[5] = 0; /* no flags */ 132 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 133 return (-1); 134 if ((buf = malloc(needed)) == NULL) 135 return (-1); 136 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 137 free(buf); 138 return (-1); 139 } 140 141 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 142 rtm = (struct rt_msghdr *)(void *)next; 143 if (rtm->rtm_version != RTM_VERSION) 144 continue; 145 switch (rtm->rtm_type) { 146 case RTM_IFINFO: 147 ifm = (struct if_msghdr *)(void *)rtm; 148 if (ifm->ifm_addrs & RTA_IFP) { 149 idx = ifm->ifm_index; 150 ++icnt; 151 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 152 dcnt += SA_RLEN((struct sockaddr *)(void*)dl) + 153 ALIGNBYTES; 154 #ifdef HAVE_IFM_DATA 155 dcnt += sizeof(ifm->ifm_data); 156 #endif /* HAVE_IFM_DATA */ 157 ncnt += dl->sdl_nlen + 1; 158 } else 159 idx = 0; 160 break; 161 162 case RTM_NEWADDR: 163 ifam = (struct ifa_msghdr *)(void *)rtm; 164 if (idx && ifam->ifam_index != idx) 165 abort(); /* this cannot happen */ 166 167 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) 168 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 169 break; 170 p = (char *)(void *)(ifam + 1); 171 ++icnt; 172 #ifdef HAVE_IFAM_DATA 173 dcnt += sizeof(ifam->ifam_data) + ALIGNBYTES; 174 #endif /* HAVE_IFAM_DATA */ 175 /* Scan to look for length of address */ 176 alen = 0; 177 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 178 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 179 == 0) 180 continue; 181 sa = (struct sockaddr *)(void *)p; 182 len = SA_RLEN(sa); 183 if (i == RTAX_IFA) { 184 alen = len; 185 break; 186 } 187 p += len; 188 } 189 for (p = p0, i = 0; i < RTAX_MAX; i++) { 190 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 191 == 0) 192 continue; 193 sa = (struct sockaddr *)(void *)p; 194 len = SA_RLEN(sa); 195 if (i == RTAX_NETMASK && SA_LEN(sa) == 0) 196 dcnt += alen; 197 else 198 dcnt += len; 199 p += len; 200 } 201 break; 202 } 203 } 204 #else /* NET_RT_IFLIST */ 205 ifc.ifc_buf = buf; 206 ifc.ifc_len = sizeof(buf); 207 208 if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) 209 return (-1); 210 i = ioctl(sock, SIOCGIFCONF, (char *)&ifc); 211 close(sock); 212 if (i < 0) 213 return (-1); 214 215 ifr = ifc.ifc_req; 216 lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len]; 217 218 while (ifr < lifr) { 219 struct sockaddr *sa; 220 221 sa = &ifr->ifr_addr; 222 ++icnt; 223 dcnt += SA_RLEN(sa); 224 ncnt += sizeof(ifr->ifr_name) + 1; 225 226 ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa)); 227 } 228 #endif /* NET_RT_IFLIST */ 229 230 if (icnt + dcnt + ncnt == 1) { 231 *pif = NULL; 232 free(buf); 233 return (0); 234 } 235 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt); 236 if (data == NULL) { 237 free(buf); 238 return(-1); 239 } 240 241 ifa = (struct ifaddrs *)(void *)data; 242 data += sizeof(struct ifaddrs) * icnt; 243 names = data + dcnt; 244 245 memset(ifa, 0, sizeof(struct ifaddrs) * icnt); 246 ift = ifa; 247 248 #ifdef NET_RT_IFLIST 249 idx = 0; 250 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 251 rtm = (struct rt_msghdr *)(void *)next; 252 if (rtm->rtm_version != RTM_VERSION) 253 continue; 254 switch (rtm->rtm_type) { 255 case RTM_IFINFO: 256 ifm = (struct if_msghdr *)(void *)rtm; 257 if (ifm->ifm_addrs & RTA_IFP) { 258 idx = ifm->ifm_index; 259 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 260 261 cif = ift; 262 ift->ifa_name = names; 263 ift->ifa_flags = (int)ifm->ifm_flags; 264 memcpy(names, dl->sdl_data, 265 (size_t)dl->sdl_nlen); 266 names[dl->sdl_nlen] = 0; 267 names += dl->sdl_nlen + 1; 268 269 ift->ifa_addr = (struct sockaddr *)(void *)data; 270 memcpy(data, dl, 271 (size_t)SA_LEN((struct sockaddr *) 272 (void *)dl)); 273 data += SA_RLEN((struct sockaddr *)(void *)dl); 274 275 #ifdef HAVE_IFM_DATA 276 /* ifm_data needs to be aligned */ 277 ift->ifa_data = data = (void *)ALIGN(data); 278 memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data)); 279 data += sizeof(ifm->ifm_data); 280 #else /* HAVE_IFM_DATA */ 281 ift->ifa_data = NULL; 282 #endif /* HAVE_IFM_DATA */ 283 284 ift = (ift->ifa_next = ift + 1); 285 } else 286 idx = 0; 287 break; 288 289 case RTM_NEWADDR: 290 ifam = (struct ifa_msghdr *)(void *)rtm; 291 if (idx && ifam->ifam_index != idx) 292 abort(); /* this cannot happen */ 293 294 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 295 break; 296 ift->ifa_name = cif->ifa_name; 297 ift->ifa_flags = cif->ifa_flags; 298 ift->ifa_data = NULL; 299 p = (char *)(void *)(ifam + 1); 300 /* Scan to look for length of address */ 301 alen = 0; 302 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 303 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 304 == 0) 305 continue; 306 sa = (struct sockaddr *)(void *)p; 307 len = SA_RLEN(sa); 308 if (i == RTAX_IFA) { 309 alen = len; 310 break; 311 } 312 p += len; 313 } 314 for (p = p0, i = 0; i < RTAX_MAX; i++) { 315 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 316 == 0) 317 continue; 318 sa = (struct sockaddr *)(void *)p; 319 len = SA_RLEN(sa); 320 switch (i) { 321 case RTAX_IFA: 322 ift->ifa_addr = 323 (struct sockaddr *)(void *)data; 324 memcpy(data, p, len); 325 data += len; 326 break; 327 328 case RTAX_NETMASK: 329 ift->ifa_netmask = 330 (struct sockaddr *)(void *)data; 331 if (SA_LEN(sa) == 0) { 332 memset(data, 0, alen); 333 data += alen; 334 break; 335 } 336 memcpy(data, p, len); 337 data += len; 338 break; 339 340 case RTAX_BRD: 341 ift->ifa_broadaddr = 342 (struct sockaddr *)(void *)data; 343 memcpy(data, p, len); 344 data += len; 345 break; 346 } 347 p += len; 348 } 349 350 #ifdef HAVE_IFAM_DATA 351 /* ifam_data needs to be aligned */ 352 ift->ifa_data = data = (void *)ALIGN(data); 353 memcpy(data, &ifam->ifam_data, sizeof(ifam->ifam_data)); 354 data += sizeof(ifam->ifam_data); 355 #endif /* HAVE_IFAM_DATA */ 356 357 ift = (ift->ifa_next = ift + 1); 358 break; 359 } 360 } 361 362 free(buf); 363 #else /* NET_RT_IFLIST */ 364 ifr = ifc.ifc_req; 365 lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len]; 366 367 while (ifr < lifr) { 368 struct sockaddr *sa; 369 370 ift->ifa_name = names; 371 names[sizeof(ifr->ifr_name)] = 0; 372 strncpy(names, ifr->ifr_name, sizeof(ifr->ifr_name)); 373 while (*names++) 374 ; 375 376 ift->ifa_addr = (struct sockaddr *)data; 377 sa = &ifr->ifr_addr; 378 memcpy(data, sa, SA_LEN(sa)); 379 data += SA_RLEN(sa); 380 381 ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa)); 382 ift = (ift->ifa_next = ift + 1); 383 } 384 #endif /* NET_RT_IFLIST */ 385 if (--ift >= ifa) { 386 ift->ifa_next = NULL; 387 *pif = ifa; 388 } else { 389 *pif = NULL; 390 free(ifa); 391 } 392 return (0); 393 } 394 395 void 396 freeifaddrs(struct ifaddrs *ifp) 397 { 398 399 _DIAGASSERT(ifp != NULL); 400 401 free(ifp); 402 } 403