getifaddrs.c revision 1.11.20.3
1 /* $NetBSD: getifaddrs.c,v 1.11.20.3 2010/05/13 05:38:16 matt 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 1.11.20.3 2010/05/13 05:38:16 matt 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 #include <sys/param.h> 39 #include <net/route.h> 40 #include <sys/sysctl.h> 41 #include <net/if_dl.h> 42 43 #include <assert.h> 44 #include <errno.h> 45 #include <ifaddrs.h> 46 #include <stdlib.h> 47 #include <string.h> 48 49 #ifdef RTDEBUG 50 #include <stdio.h> 51 #endif 52 53 #ifdef __weak_alias 54 __weak_alias(getifaddrs,_getifaddrs) 55 __weak_alias(freeifaddrs,_freeifaddrs) 56 #endif 57 58 #define SA_RLEN(sa) RT_ROUNDUP((sa)->sa_len) 59 60 int 61 getifaddrs(struct ifaddrs **pif) 62 { 63 int icnt = 1; 64 int dcnt = 0; 65 int ncnt = 0; 66 int mib[6]; 67 size_t needed; 68 char *buf; 69 char *next; 70 struct ifaddrs cif; 71 char *p, *p0; 72 struct rt_msghdr *rtm; 73 struct if_msghdr *ifm; 74 struct ifa_msghdr *ifam; 75 struct sockaddr *sa; 76 struct ifaddrs *ifa, *ift; 77 u_short idx = 0; 78 int i; 79 size_t len, alen; 80 char *data; 81 char *names; 82 83 #ifdef RTDEBUG 84 static const char rtax_names[][8] = RTAX_NAMES; 85 #endif 86 87 _DIAGASSERT(pif != NULL); 88 89 mib[0] = CTL_NET; 90 mib[1] = PF_ROUTE; 91 mib[2] = 0; /* protocol */ 92 mib[3] = 0; /* wildcard address family */ 93 mib[4] = NET_RT_IFLIST; 94 mib[5] = 0; /* no flags */ 95 if (sysctl(mib, __arraycount(mib), NULL, &needed, NULL, 0) < 0) 96 return (-1); 97 if ((buf = malloc(needed)) == NULL) 98 return (-1); 99 if (sysctl(mib, __arraycount(mib), buf, &needed, NULL, 0) < 0) { 100 free(buf); 101 return (-1); 102 } 103 104 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 105 rtm = (struct rt_msghdr *)(void *)next; 106 if (rtm->rtm_version != RTM_VERSION) 107 continue; 108 #ifdef RTDEBUG 109 printf("%d: %zd rtm len=%d type=%d\n", __LINE__, 110 (char *)rtm - buf, 111 rtm->rtm_msglen, rtm->rtm_type); 112 #endif 113 switch (rtm->rtm_type) { 114 case RTM_IFINFO: 115 ifm = (struct if_msghdr *)(void *)rtm; 116 if (ifm->ifm_addrs & RTA_IFP) { 117 const struct sockaddr_dl *dl; 118 119 idx = ifm->ifm_index; 120 ++icnt; 121 dl = (struct sockaddr_dl *) 122 ((uintptr_t)ifm + RT_ROUNDUP(sizeof(*ifm))); 123 dcnt += SA_RLEN((const struct sockaddr *)(const void *)dl); 124 dcnt += RT_ROUNDUP(sizeof(ifm->ifm_data)); 125 ncnt += dl->sdl_nlen + 1; 126 #ifdef RTDEBUG 127 printf("%d: %zd sdl idx=%d dcnt=%#x flags=%#x name=", 128 __LINE__, (const char *)dl - buf, idx, 129 dcnt, ifm->ifm_flags); 130 fwrite(dl->sdl_data, 1, dl->sdl_nlen, stdout); 131 putchar('\n'); 132 #endif 133 } else 134 idx = 0; 135 break; 136 137 case RTM_NEWADDR: 138 ifam = (struct ifa_msghdr *)(void *)rtm; 139 if (idx && ifam->ifam_index != idx) 140 abort(); /* this cannot happen */ 141 142 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) 143 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 144 break; 145 p = (char *) 146 ((uintptr_t)ifam + RT_ROUNDUP(sizeof(*ifam))); 147 ++icnt; 148 #ifdef RTDEBUG 149 printf("%d: %zd sa index=%d addrs=%#x\n", 150 __LINE__, p - buf, 151 ifam->ifam_index, ifam->ifam_addrs); 152 #endif 153 /* Scan to look for length of address */ 154 alen = 0; 155 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 156 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 157 == 0) 158 continue; 159 sa = (struct sockaddr *)(void *)p; 160 len = SA_RLEN(sa); 161 #ifdef RTDEBUG 162 printf("%d: %zd sa %s len=%d family=%d\n", 163 __LINE__, p - buf, rtax_names[i], 164 sa->sa_len, sa->sa_family); 165 #endif 166 if (i == RTAX_IFA) { 167 alen = len; 168 break; 169 } 170 p += len; 171 } 172 for (p = p0, i = 0; i < RTAX_MAX; i++) { 173 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 174 == 0) 175 continue; 176 sa = (struct sockaddr *)(void *)p; 177 len = SA_RLEN(sa); 178 if (i == RTAX_NETMASK && sa->sa_len == 0) 179 dcnt += alen; 180 else 181 dcnt += len; 182 #ifdef RTDEBUG 183 printf("%d: %zd sa %s dcnt=%#x, len=%d family=%d\n", 184 __LINE__, p - buf, rtax_names[i], dcnt, 185 sa->sa_len, sa->sa_family); 186 #endif 187 p += len; 188 } 189 break; 190 } 191 } 192 193 if (icnt + dcnt + ncnt == 1) { 194 *pif = NULL; 195 free(buf); 196 return (0); 197 } 198 data = malloc(RT_ROUNDUP(sizeof(struct ifaddrs) * icnt) + dcnt + ncnt); 199 if (data == NULL) { 200 free(buf); 201 return(-1); 202 } 203 204 ifa = (struct ifaddrs *)(void *)data; 205 data += RT_ROUNDUP(sizeof(struct ifaddrs) * icnt); 206 names = data + dcnt; 207 208 memset(ifa, 0, sizeof(struct ifaddrs) * icnt); 209 ift = ifa; 210 #ifdef RTDEBUG 211 printf("ifa=%p data=%p names=%p end=%p\n", 212 ifa, data, names, names + ncnt); 213 #endif 214 215 idx = 0; 216 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 217 rtm = (struct rt_msghdr *)(void *)next; 218 if (rtm->rtm_version != RTM_VERSION) 219 continue; 220 #ifdef RTDEBUG 221 printf("%d: %zd rtm len=%d type=%d\n", __LINE__, 222 (char *)rtm - buf, 223 rtm->rtm_msglen, rtm->rtm_type); 224 #endif 225 switch (rtm->rtm_type) { 226 case RTM_IFINFO: 227 ifm = (struct if_msghdr *)(void *)rtm; 228 if (ifm->ifm_addrs & RTA_IFP) { 229 const struct sockaddr_dl *dl; 230 231 idx = ifm->ifm_index; 232 dl = (struct sockaddr_dl *) 233 ((uintptr_t)ifm + RT_ROUNDUP(sizeof(*ifm))); 234 235 memset(&cif, 0, sizeof(cif)); 236 237 cif.ifa_name = names; 238 cif.ifa_flags = (int)ifm->ifm_flags; 239 memcpy(names, dl->sdl_data, 240 (size_t)dl->sdl_nlen); 241 names[dl->sdl_nlen] = 0; 242 243 #ifdef RTDEBUG 244 printf("%d: %zd sdl idx=%d flags=%#x name=%s\n", 245 __LINE__, (const char *)dl - buf, idx, 246 ifm->ifm_flags, names); 247 #endif 248 names += dl->sdl_nlen + 1; 249 250 cif.ifa_addr = (struct sockaddr *)(void *)data; 251 memcpy(data, dl, (size_t)dl->sdl_len); 252 data += SA_RLEN((const struct sockaddr *)(const void *)dl); 253 254 /* ifm_data needs to be aligned */ 255 cif.ifa_data = data = (void *)ALIGN(data); 256 memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data)); 257 data += sizeof(ifm->ifm_data); 258 } else 259 idx = 0; 260 break; 261 262 case RTM_NEWADDR: 263 ifam = (struct ifa_msghdr *)(void *)rtm; 264 if (idx && ifam->ifam_index != idx) 265 abort(); /* this cannot happen */ 266 267 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 268 break; 269 ift->ifa_name = cif.ifa_name; 270 ift->ifa_flags = cif.ifa_flags; 271 ift->ifa_data = NULL; 272 p = (char *) 273 ((uintptr_t)ifam + RT_ROUNDUP(sizeof(*ifam))); 274 #ifdef RTDEBUG 275 printf("%d: %zd sa index=%d addrs=%#x name=%s\n", 276 __LINE__, p - buf, 277 ifam->ifam_index, ifam->ifam_addrs, ifa->ifa_name); 278 #endif 279 /* Scan to look for length of address */ 280 alen = 0; 281 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 282 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 283 == 0) 284 continue; 285 sa = (struct sockaddr *)(void *)p; 286 len = SA_RLEN(sa); 287 #ifdef RTDEBUG 288 printf("%d: %zd sa %s len=%d family=%d\n", 289 __LINE__, p - buf, rtax_names[i], 290 sa->sa_len, sa->sa_family); 291 #endif 292 if (i == RTAX_IFA) { 293 alen = len; 294 break; 295 } 296 p += len; 297 } 298 for (p = p0, i = 0; i < RTAX_MAX; i++) { 299 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 300 == 0) 301 continue; 302 sa = (struct sockaddr *)(void *)p; 303 len = SA_RLEN(sa); 304 #ifdef RTDEBUG 305 printf("%d: %zd sa %s len=%d family=%d\n", 306 __LINE__, p - buf, rtax_names[i], 307 sa->sa_len, sa->sa_family); 308 #endif 309 switch (i) { 310 case RTAX_IFA: 311 ift->ifa_addr = 312 (struct sockaddr *)(void *)data; 313 memcpy(data, p, len); 314 data += len; 315 if (ift->ifa_addr->sa_family == AF_LINK) 316 ift->ifa_data = cif.ifa_data; 317 break; 318 319 case RTAX_NETMASK: 320 ift->ifa_netmask = 321 (struct sockaddr *)(void *)data; 322 if (sa->sa_len == 0) { 323 memset(data, 0, alen); 324 data += alen; 325 break; 326 } 327 memcpy(data, p, len); 328 data += len; 329 break; 330 331 case RTAX_BRD: 332 ift->ifa_broadaddr = 333 (struct sockaddr *)(void *)data; 334 memcpy(data, p, len); 335 data += len; 336 break; 337 } 338 p += len; 339 } 340 341 #ifdef RTDEBUG 342 if (ift->ifa_name == NULL || ift->ifa_name[0] == 0) 343 printf("%p: ifa_name == NULL!\n", ift); 344 else 345 printf("%p: ifa_name=%s\n", ift, ift->ifa_name); 346 #endif 347 ift = (ift->ifa_next = ift + 1); 348 break; 349 } 350 } 351 352 #ifdef RTDEBUG 353 printf("ifa=%p data=%p names=%p\n", 354 ifa, data, names); 355 #endif 356 357 free(buf); 358 if (--ift >= ifa) { 359 ift->ifa_next = NULL; 360 *pif = ifa; 361 } else { 362 *pif = NULL; 363 free(ifa); 364 } 365 return (0); 366 } 367 368 void 369 freeifaddrs(struct ifaddrs *ifp) 370 { 371 372 _DIAGASSERT(ifp != NULL); 373 374 free(ifp); 375 } 376
Indexes created Mon Sep 29 21:09:56 GMT 2025