getifaddrs.c revision 1.11.20.2
1 /* $NetBSD: getifaddrs.c,v 1.11.20.2 2010/05/11 21:01:23 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 1.11.20.2 2010/05/11 21:01:23 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 __weak_alias 50 __weak_alias(getifaddrs,_getifaddrs) 51 __weak_alias(freeifaddrs,_freeifaddrs) 52 #endif 53 54 #define SA_RLEN(sa) RT_ROUNDUP((sa)->sa_len) 55 56 int 57 getifaddrs(struct ifaddrs **pif) 58 { 59 int icnt = 1; 60 int dcnt = 0; 61 int ncnt = 0; 62 int mib[6]; 63 size_t needed; 64 char *buf; 65 char *next; 66 struct ifaddrs cif; 67 char *p, *p0; 68 struct rt_msghdr *rtm; 69 struct if_msghdr *ifm; 70 struct ifa_msghdr *ifam; 71 struct sockaddr *sa; 72 struct ifaddrs *ifa, *ift; 73 u_short idx = 0; 74 int i; 75 size_t len, alen; 76 char *data; 77 char *names; 78 79 _DIAGASSERT(pif != NULL); 80 81 mib[0] = CTL_NET; 82 mib[1] = PF_ROUTE; 83 mib[2] = 0; /* protocol */ 84 mib[3] = 0; /* wildcard address family */ 85 mib[4] = NET_RT_IFLIST; 86 mib[5] = 0; /* no flags */ 87 if (sysctl(mib, __arraycount(mib), NULL, &needed, NULL, 0) < 0) 88 return (-1); 89 if ((buf = malloc(needed)) == NULL) 90 return (-1); 91 if (sysctl(mib, __arraycount(mib), buf, &needed, NULL, 0) < 0) { 92 free(buf); 93 return (-1); 94 } 95 96 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 97 rtm = (struct rt_msghdr *)(void *)next; 98 if (rtm->rtm_version != RTM_VERSION) 99 continue; 100 switch (rtm->rtm_type) { 101 case RTM_IFINFO: 102 ifm = (struct if_msghdr *)(void *)rtm; 103 if (ifm->ifm_addrs & RTA_IFP) { 104 const struct sockaddr_dl *dl; 105 106 idx = ifm->ifm_index; 107 ++icnt; 108 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 109 dcnt += SA_RLEN((const struct sockaddr *)(const void *)dl); 110 dcnt += sizeof(ifm->ifm_data); 111 ncnt += dl->sdl_nlen + 1; 112 } else 113 idx = 0; 114 break; 115 116 case RTM_NEWADDR: 117 ifam = (struct ifa_msghdr *)(void *)rtm; 118 if (idx && ifam->ifam_index != idx) 119 abort(); /* this cannot happen */ 120 121 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) 122 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 123 break; 124 p = (char *)(void *)(ifam + 1); 125 ++icnt; 126 /* Scan to look for length of address */ 127 alen = 0; 128 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 129 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 130 == 0) 131 continue; 132 sa = (struct sockaddr *)(void *)p; 133 len = SA_RLEN(sa); 134 if (i == RTAX_IFA) { 135 alen = len; 136 break; 137 } 138 p += len; 139 } 140 for (p = p0, i = 0; i < RTAX_MAX; i++) { 141 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 142 == 0) 143 continue; 144 sa = (struct sockaddr *)(void *)p; 145 len = SA_RLEN(sa); 146 if (i == RTAX_NETMASK && sa->sa_len == 0) 147 dcnt += alen; 148 else 149 dcnt += len; 150 p += len; 151 } 152 break; 153 } 154 } 155 156 if (icnt + dcnt + ncnt == 1) { 157 *pif = NULL; 158 free(buf); 159 return (0); 160 } 161 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt); 162 if (data == NULL) { 163 free(buf); 164 return(-1); 165 } 166 167 ifa = (struct ifaddrs *)(void *)data; 168 data += sizeof(struct ifaddrs) * icnt; 169 names = data + dcnt; 170 171 memset(ifa, 0, sizeof(struct ifaddrs) * icnt); 172 ift = ifa; 173 174 idx = 0; 175 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 176 rtm = (struct rt_msghdr *)(void *)next; 177 if (rtm->rtm_version != RTM_VERSION) 178 continue; 179 switch (rtm->rtm_type) { 180 case RTM_IFINFO: 181 ifm = (struct if_msghdr *)(void *)rtm; 182 if (ifm->ifm_addrs & RTA_IFP) { 183 const struct sockaddr_dl *dl; 184 185 idx = ifm->ifm_index; 186 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 187 188 memset(&cif, 0, sizeof(cif)); 189 190 cif.ifa_name = names; 191 cif.ifa_flags = (int)ifm->ifm_flags; 192 memcpy(names, dl->sdl_data, 193 (size_t)dl->sdl_nlen); 194 names[dl->sdl_nlen] = 0; 195 names += dl->sdl_nlen + 1; 196 197 cif.ifa_addr = (struct sockaddr *)(void *)data; 198 memcpy(data, dl, (size_t)dl->sdl_len); 199 data += SA_RLEN((const struct sockaddr *)(const void *)dl); 200 201 /* ifm_data needs to be aligned */ 202 cif.ifa_data = data = (void *)ALIGN(data); 203 memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data)); 204 data += sizeof(ifm->ifm_data); 205 } else 206 idx = 0; 207 break; 208 209 case RTM_NEWADDR: 210 ifam = (struct ifa_msghdr *)(void *)rtm; 211 if (idx && ifam->ifam_index != idx) 212 abort(); /* this cannot happen */ 213 214 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 215 break; 216 ift->ifa_name = cif.ifa_name; 217 ift->ifa_flags = cif.ifa_flags; 218 ift->ifa_data = NULL; 219 p = (char *)(void *)(ifam + 1); 220 /* Scan to look for length of address */ 221 alen = 0; 222 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 223 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 224 == 0) 225 continue; 226 sa = (struct sockaddr *)(void *)p; 227 len = SA_RLEN(sa); 228 if (i == RTAX_IFA) { 229 alen = len; 230 break; 231 } 232 p += len; 233 } 234 for (p = p0, i = 0; i < RTAX_MAX; i++) { 235 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 236 == 0) 237 continue; 238 sa = (struct sockaddr *)(void *)p; 239 len = SA_RLEN(sa); 240 switch (i) { 241 case RTAX_IFA: 242 ift->ifa_addr = 243 (struct sockaddr *)(void *)data; 244 memcpy(data, p, len); 245 data += len; 246 if (ift->ifa_addr->sa_family == AF_LINK) 247 ift->ifa_data = cif.ifa_data; 248 break; 249 250 case RTAX_NETMASK: 251 ift->ifa_netmask = 252 (struct sockaddr *)(void *)data; 253 if (sa->sa_len == 0) { 254 memset(data, 0, alen); 255 data += alen; 256 break; 257 } 258 memcpy(data, p, len); 259 data += len; 260 break; 261 262 case RTAX_BRD: 263 ift->ifa_broadaddr = 264 (struct sockaddr *)(void *)data; 265 memcpy(data, p, len); 266 data += len; 267 break; 268 } 269 p += len; 270 } 271 272 273 ift = (ift->ifa_next = ift + 1); 274 break; 275 } 276 } 277 278 free(buf); 279 if (--ift >= ifa) { 280 ift->ifa_next = NULL; 281 *pif = ifa; 282 } else { 283 *pif = NULL; 284 free(ifa); 285 } 286 return (0); 287 } 288 289 void 290 freeifaddrs(struct ifaddrs *ifp) 291 { 292 293 _DIAGASSERT(ifp != NULL); 294 295 free(ifp); 296 } 297
Indexes created Mon Sep 29 21:09:56 GMT 2025