1 /* $NetBSD: getifaddrs.c,v 1.14 2011/02/04 02:01:12 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 1.14 2011/02/04 02:01:12 matt Exp $"); 31 #endif /* LIBC_SCCS and not lint */ 32 33 #ifndef RUMP_ACTION 34 #include "namespace.h" 35 #endif 36 #include <sys/types.h> 37 #include <sys/ioctl.h> 38 #include <sys/socket.h> 39 #include <net/if.h> 40 #include <sys/param.h> 41 #include <net/route.h> 42 #include <sys/sysctl.h> 43 #include <net/if_dl.h> 44 45 #include <assert.h> 46 #include <errno.h> 47 #include <ifaddrs.h> 48 #include <stdlib.h> 49 #include <string.h> 50 51 #if defined(__weak_alias) && !defined(RUMP_ACTION) 52 __weak_alias(getifaddrs,_getifaddrs) 53 __weak_alias(freeifaddrs,_freeifaddrs) 54 #endif 55 56 #ifdef RUMP_ACTION 57 #include <rump/rump_syscalls.h> 58 #define sysctl(a,b,c,d,e,f) rump_sys___sysctl(a,b,c,d,e,f) 59 #endif 60 61 #define SA_RLEN(sa) RT_ROUNDUP((sa)->sa_len) 62 63 int 64 getifaddrs(struct ifaddrs **pif) 65 { 66 int icnt = 1; 67 int dcnt = 0; 68 int ncnt = 0; 69 int mib[6]; 70 size_t needed; 71 char *buf; 72 char *next; 73 struct ifaddrs cif; 74 char *p, *p0; 75 struct rt_msghdr *rtm; 76 struct if_msghdr *ifm; 77 struct ifa_msghdr *ifam; 78 struct sockaddr *sa; 79 struct ifaddrs *ifa, *ift; 80 u_short idx = 0; 81 int i; 82 size_t len, alen; 83 char *data; 84 char *names; 85 86 _DIAGASSERT(pif != NULL); 87 88 mib[0] = CTL_NET; 89 mib[1] = PF_ROUTE; 90 mib[2] = 0; /* protocol */ 91 mib[3] = 0; /* wildcard address family */ 92 mib[4] = NET_RT_IFLIST; 93 mib[5] = 0; /* no flags */ 94 if (sysctl(mib, __arraycount(mib), NULL, &needed, NULL, 0) < 0) 95 return (-1); 96 if ((buf = malloc(needed)) == NULL) 97 return (-1); 98 if (sysctl(mib, __arraycount(mib), buf, &needed, NULL, 0) < 0) { 99 free(buf); 100 return (-1); 101 } 102 103 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 104 rtm = (struct rt_msghdr *)(void *)next; 105 if (rtm->rtm_version != RTM_VERSION) 106 continue; 107 switch (rtm->rtm_type) { 108 case RTM_IFINFO: 109 ifm = (struct if_msghdr *)(void *)rtm; 110 if (ifm->ifm_addrs & RTA_IFP) { 111 const struct sockaddr_dl *dl; 112 113 idx = ifm->ifm_index; 114 ++icnt; 115 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 116 dcnt += SA_RLEN((const struct sockaddr *)(const void *)dl) + 117 ALIGNBYTES; 118 dcnt += sizeof(ifm->ifm_data); 119 ncnt += dl->sdl_nlen + 1; 120 } else 121 idx = 0; 122 break; 123 124 case RTM_NEWADDR: 125 ifam = (struct ifa_msghdr *)(void *)rtm; 126 if (idx && ifam->ifam_index != idx) 127 abort(); /* this cannot happen */ 128 129 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) 130 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 131 break; 132 p = (char *)(void *)(ifam + 1); 133 ++icnt; 134 /* Scan to look for length of address */ 135 alen = 0; 136 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 137 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 138 == 0) 139 continue; 140 sa = (struct sockaddr *)(void *)p; 141 len = SA_RLEN(sa); 142 if (i == RTAX_IFA) { 143 alen = len; 144 break; 145 } 146 p += len; 147 } 148 for (p = p0, i = 0; i < RTAX_MAX; i++) { 149 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 150 == 0) 151 continue; 152 sa = (struct sockaddr *)(void *)p; 153 len = SA_RLEN(sa); 154 if (i == RTAX_NETMASK && sa->sa_len == 0) 155 dcnt += alen; 156 else 157 dcnt += len; 158 p += len; 159 } 160 break; 161 } 162 } 163 164 if (icnt + dcnt + ncnt == 1) { 165 *pif = NULL; 166 free(buf); 167 return (0); 168 } 169 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt); 170 if (data == NULL) { 171 free(buf); 172 return(-1); 173 } 174 175 ifa = (struct ifaddrs *)(void *)data; 176 data += sizeof(struct ifaddrs) * icnt; 177 names = data + dcnt; 178 179 memset(ifa, 0, sizeof(struct ifaddrs) * icnt); 180 ift = ifa; 181 182 idx = 0; 183 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 184 rtm = (struct rt_msghdr *)(void *)next; 185 if (rtm->rtm_version != RTM_VERSION) 186 continue; 187 switch (rtm->rtm_type) { 188 case RTM_IFINFO: 189 ifm = (struct if_msghdr *)(void *)rtm; 190 if (ifm->ifm_addrs & RTA_IFP) { 191 const struct sockaddr_dl *dl; 192 193 idx = ifm->ifm_index; 194 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 195 196 memset(&cif, 0, sizeof(cif)); 197 198 cif.ifa_name = names; 199 cif.ifa_flags = (int)ifm->ifm_flags; 200 memcpy(names, dl->sdl_data, 201 (size_t)dl->sdl_nlen); 202 names[dl->sdl_nlen] = 0; 203 names += dl->sdl_nlen + 1; 204 205 cif.ifa_addr = (struct sockaddr *)(void *)data; 206 memcpy(data, dl, (size_t)dl->sdl_len); 207 data += SA_RLEN((const struct sockaddr *)(const void *)dl); 208 209 /* ifm_data needs to be aligned */ 210 cif.ifa_data = data = (void *)ALIGN(data); 211 memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data)); 212 data += sizeof(ifm->ifm_data); 213 } else 214 idx = 0; 215 break; 216 217 case RTM_NEWADDR: 218 ifam = (struct ifa_msghdr *)(void *)rtm; 219 if (idx && ifam->ifam_index != idx) 220 abort(); /* this cannot happen */ 221 222 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 223 break; 224 ift->ifa_name = cif.ifa_name; 225 ift->ifa_flags = cif.ifa_flags; 226 ift->ifa_data = NULL; 227 p = (char *)(void *)(ifam + 1); 228 /* Scan to look for length of address */ 229 alen = 0; 230 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 231 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 232 == 0) 233 continue; 234 sa = (struct sockaddr *)(void *)p; 235 len = SA_RLEN(sa); 236 if (i == RTAX_IFA) { 237 alen = len; 238 break; 239 } 240 p += len; 241 } 242 for (p = p0, i = 0; i < RTAX_MAX; i++) { 243 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 244 == 0) 245 continue; 246 sa = (struct sockaddr *)(void *)p; 247 len = SA_RLEN(sa); 248 switch (i) { 249 case RTAX_IFA: 250 ift->ifa_addr = 251 (struct sockaddr *)(void *)data; 252 memcpy(data, p, len); 253 data += len; 254 if (ift->ifa_addr->sa_family == AF_LINK) 255 ift->ifa_data = cif.ifa_data; 256 break; 257 258 case RTAX_NETMASK: 259 ift->ifa_netmask = 260 (struct sockaddr *)(void *)data; 261 if (sa->sa_len == 0) { 262 memset(data, 0, alen); 263 data += alen; 264 break; 265 } 266 memcpy(data, p, len); 267 data += len; 268 break; 269 270 case RTAX_BRD: 271 ift->ifa_broadaddr = 272 (struct sockaddr *)(void *)data; 273 memcpy(data, p, len); 274 data += len; 275 break; 276 } 277 p += len; 278 } 279 280 281 ift = (ift->ifa_next = ift + 1); 282 break; 283 } 284 } 285 286 free(buf); 287 if (--ift >= ifa) { 288 ift->ifa_next = NULL; 289 *pif = ifa; 290 } else { 291 *pif = NULL; 292 free(ifa); 293 } 294 return (0); 295 } 296 297 void 298 freeifaddrs(struct ifaddrs *ifp) 299 { 300 301 _DIAGASSERT(ifp != NULL); 302 303 free(ifp); 304 } 305