1 /* $KAME: getifaddrs.c,v 1.9 2001/08/20 02:31:20 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 * NOTE: SIOCGIFCONF case is not LP64 friendly. it also does not perform 29 * try-and-error for region size. 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include "namespace.h" 36 #include <sys/types.h> 37 #include <sys/ioctl.h> 38 #include <sys/socket.h> 39 #include <net/if.h> 40 #ifdef NET_RT_IFLIST 41 #include <sys/param.h> 42 #include <net/route.h> 43 #include <sys/sysctl.h> 44 #include <net/if_dl.h> 45 #endif 46 47 #include <errno.h> 48 #include <ifaddrs.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include "un-namespace.h" 52 53 #if !defined(AF_LINK) 54 #define SA_LEN(sa) sizeof(struct sockaddr) 55 #endif 56 57 #if !defined(SA_LEN) 58 #define SA_LEN(sa) (sa)->sa_len 59 #endif 60 61 #define SALIGN (sizeof(long) - 1) 62 #define SA_RLEN(sa) ((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1)) 63 64 #ifndef ALIGNBYTES 65 /* 66 * On systems with a routing socket, ALIGNBYTES should match the value 67 * that the kernel uses when building the messages. 68 */ 69 #define ALIGNBYTES XXX 70 #endif 71 #ifndef ALIGN 72 #define ALIGN(p) (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES) 73 #endif 74 75 #if _BSDI_VERSION >= 199701 76 #define HAVE_IFM_DATA 77 #endif 78 79 #if _BSDI_VERSION >= 199802 80 /* ifam_data is very specific to recent versions of bsdi */ 81 #define HAVE_IFAM_DATA 82 #endif 83 84 #if defined(__NetBSD__) || defined(__OpenBSD__) || defined(__FreeBSD__) 85 #define HAVE_IFM_DATA 86 #endif 87 88 #define MAX_SYSCTL_TRY 5 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 ntry = 0; 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 #ifdef NET_RT_IFLIST 124 mib[0] = CTL_NET; 125 mib[1] = PF_ROUTE; 126 mib[2] = 0; /* protocol */ 127 mib[3] = 0; /* wildcard address family */ 128 mib[4] = NET_RT_IFLIST; 129 mib[5] = 0; /* no flags */ 130 do { 131 /* 132 * We'll try to get addresses several times in case that 133 * the number of addresses is unexpectedly increased during 134 * the two sysctl calls. This should rarely happen, but we'll 135 * try to do our best for applications that assume success of 136 * this library (which should usually be the case). 137 * Portability note: since FreeBSD does not add margin of 138 * memory at the first sysctl, the possibility of failure on 139 * the second sysctl call is a bit higher. 140 */ 141 142 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 143 return (-1); 144 if ((buf = malloc(needed)) == NULL) 145 return (-1); 146 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 147 if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) { 148 free(buf); 149 return (-1); 150 } 151 free(buf); 152 buf = NULL; 153 } 154 } while (buf == NULL); 155 156 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 157 rtm = (struct rt_msghdr *)(void *)next; 158 if (rtm->rtm_version != RTM_VERSION) 159 continue; 160 switch (rtm->rtm_type) { 161 case RTM_IFINFO: 162 ifm = (struct if_msghdr *)(void *)rtm; 163 if (ifm->ifm_addrs & RTA_IFP) { 164 idx = ifm->ifm_index; 165 ++icnt; 166 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 167 dcnt += SA_RLEN((struct sockaddr *)(void*)dl) + 168 ALIGNBYTES; 169 #ifdef HAVE_IFM_DATA 170 dcnt += sizeof(ifm->ifm_data); 171 #endif /* HAVE_IFM_DATA */ 172 ncnt += dl->sdl_nlen + 1; 173 } else 174 idx = 0; 175 break; 176 177 case RTM_NEWADDR: 178 ifam = (struct ifa_msghdr *)(void *)rtm; 179 if (idx && ifam->ifam_index != idx) 180 abort(); /* this cannot happen */ 181 182 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) 183 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 184 break; 185 p = (char *)(void *)(ifam + 1); 186 ++icnt; 187 #ifdef HAVE_IFAM_DATA 188 dcnt += sizeof(ifam->ifam_data) + ALIGNBYTES; 189 #endif /* HAVE_IFAM_DATA */ 190 /* Scan to look for length of address */ 191 alen = 0; 192 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 193 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 194 == 0) 195 continue; 196 sa = (struct sockaddr *)(void *)p; 197 len = SA_RLEN(sa); 198 if (i == RTAX_IFA) { 199 alen = len; 200 break; 201 } 202 p += len; 203 } 204 for (p = p0, i = 0; i < RTAX_MAX; i++) { 205 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 206 == 0) 207 continue; 208 sa = (struct sockaddr *)(void *)p; 209 len = SA_RLEN(sa); 210 if (i == RTAX_NETMASK && SA_LEN(sa) == 0) 211 dcnt += alen; 212 else 213 dcnt += len; 214 p += len; 215 } 216 break; 217 } 218 } 219 #else /* NET_RT_IFLIST */ 220 ifc.ifc_buf = buf; 221 ifc.ifc_len = sizeof(buf); 222 223 if ((sock = _socket(AF_INET, SOCK_STREAM, 0)) < 0) 224 return (-1); 225 i = _ioctl(sock, SIOCGIFCONF, (char *)&ifc); 226 _close(sock); 227 if (i < 0) 228 return (-1); 229 230 ifr = ifc.ifc_req; 231 lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len]; 232 233 while (ifr < lifr) { 234 struct sockaddr *sa; 235 236 sa = &ifr->ifr_addr; 237 ++icnt; 238 dcnt += SA_RLEN(sa); 239 ncnt += sizeof(ifr->ifr_name) + 1; 240 241 if (SA_LEN(sa) < sizeof(*sa)) 242 ifr = (struct ifreq *)(((char *)sa) + sizeof(*sa)); 243 else 244 ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa)); 245 } 246 #endif /* NET_RT_IFLIST */ 247 248 if (icnt + dcnt + ncnt == 1) { 249 *pif = NULL; 250 free(buf); 251 return (0); 252 } 253 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt); 254 if (data == NULL) { 255 free(buf); 256 return(-1); 257 } 258 259 ifa = (struct ifaddrs *)(void *)data; 260 data += sizeof(struct ifaddrs) * icnt; 261 names = data + dcnt; 262 263 memset(ifa, 0, sizeof(struct ifaddrs) * icnt); 264 ift = ifa; 265 266 #ifdef NET_RT_IFLIST 267 idx = 0; 268 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 269 rtm = (struct rt_msghdr *)(void *)next; 270 if (rtm->rtm_version != RTM_VERSION) 271 continue; 272 switch (rtm->rtm_type) { 273 case RTM_IFINFO: 274 ifm = (struct if_msghdr *)(void *)rtm; 275 if (ifm->ifm_addrs & RTA_IFP) { 276 idx = ifm->ifm_index; 277 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 278 279 cif = ift; 280 ift->ifa_name = names; 281 ift->ifa_flags = (int)ifm->ifm_flags; 282 memcpy(names, dl->sdl_data, 283 (size_t)dl->sdl_nlen); 284 names[dl->sdl_nlen] = 0; 285 names += dl->sdl_nlen + 1; 286 287 ift->ifa_addr = (struct sockaddr *)(void *)data; 288 memcpy(data, dl, 289 (size_t)SA_LEN((struct sockaddr *) 290 (void *)dl)); 291 data += SA_RLEN((struct sockaddr *)(void *)dl); 292 293 #ifdef HAVE_IFM_DATA 294 /* ifm_data needs to be aligned */ 295 ift->ifa_data = data = (void *)ALIGN(data); 296 memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data)); 297 data += sizeof(ifm->ifm_data); 298 #else /* HAVE_IFM_DATA */ 299 ift->ifa_data = NULL; 300 #endif /* HAVE_IFM_DATA */ 301 302 ift = (ift->ifa_next = ift + 1); 303 } else 304 idx = 0; 305 break; 306 307 case RTM_NEWADDR: 308 ifam = (struct ifa_msghdr *)(void *)rtm; 309 if (idx && ifam->ifam_index != idx) 310 abort(); /* this cannot happen */ 311 312 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 313 break; 314 ift->ifa_name = cif->ifa_name; 315 ift->ifa_flags = cif->ifa_flags; 316 ift->ifa_data = NULL; 317 p = (char *)(void *)(ifam + 1); 318 /* Scan to look for length of address */ 319 alen = 0; 320 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 321 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 322 == 0) 323 continue; 324 sa = (struct sockaddr *)(void *)p; 325 len = SA_RLEN(sa); 326 if (i == RTAX_IFA) { 327 alen = len; 328 break; 329 } 330 p += len; 331 } 332 for (p = p0, i = 0; i < RTAX_MAX; i++) { 333 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 334 == 0) 335 continue; 336 sa = (struct sockaddr *)(void *)p; 337 len = SA_RLEN(sa); 338 switch (i) { 339 case RTAX_IFA: 340 ift->ifa_addr = 341 (struct sockaddr *)(void *)data; 342 memcpy(data, p, len); 343 data += len; 344 break; 345 346 case RTAX_NETMASK: 347 ift->ifa_netmask = 348 (struct sockaddr *)(void *)data; 349 if (SA_LEN(sa) == 0) { 350 memset(data, 0, alen); 351 data += alen; 352 break; 353 } 354 memcpy(data, p, len); 355 data += len; 356 break; 357 358 case RTAX_BRD: 359 ift->ifa_broadaddr = 360 (struct sockaddr *)(void *)data; 361 memcpy(data, p, len); 362 data += len; 363 break; 364 } 365 p += len; 366 } 367 368 #ifdef HAVE_IFAM_DATA 369 /* ifam_data needs to be aligned */ 370 ift->ifa_data = data = (void *)ALIGN(data); 371 memcpy(data, &ifam->ifam_data, sizeof(ifam->ifam_data)); 372 data += sizeof(ifam->ifam_data); 373 #endif /* HAVE_IFAM_DATA */ 374 375 ift = (ift->ifa_next = ift + 1); 376 break; 377 } 378 } 379 380 free(buf); 381 #else /* NET_RT_IFLIST */ 382 ifr = ifc.ifc_req; 383 lifr = (struct ifreq *)&ifc.ifc_buf[ifc.ifc_len]; 384 385 while (ifr < lifr) { 386 struct sockaddr *sa; 387 388 ift->ifa_name = names; 389 names[sizeof(ifr->ifr_name)] = 0; 390 strncpy(names, ifr->ifr_name, sizeof(ifr->ifr_name)); 391 while (*names++) 392 ; 393 394 ift->ifa_addr = (struct sockaddr *)data; 395 sa = &ifr->ifr_addr; 396 memcpy(data, sa, SA_LEN(sa)); 397 data += SA_RLEN(sa); 398 399 ifr = (struct ifreq *)(((char *)sa) + SA_LEN(sa)); 400 ift = (ift->ifa_next = ift + 1); 401 } 402 #endif /* NET_RT_IFLIST */ 403 if (--ift >= ifa) { 404 ift->ifa_next = NULL; 405 *pif = ifa; 406 } else { 407 *pif = NULL; 408 free(ifa); 409 } 410 return (0); 411 } 412 413 void 414 freeifaddrs(struct ifaddrs *ifp) 415 { 416 417 free(ifp); 418 } 419