1 /* $FreeBSD: src/lib/libc/net/getifaddrs.c,v 1.6 2002/07/25 08:08:30 ume Exp $ */ 2 /* $KAME: getifaddrs.c,v 1.9 2001/08/20 02:31:20 itojun Exp $ */ 3 4 /* 5 * Copyright (c) 1995, 1999 6 * Berkeley Software Design, Inc. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 14 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * BSDI getifaddrs.c,v 2.12 2000/02/23 14:51:59 dab Exp 27 */ 28 /* 29 * NOTE: SIOCGIFCONF case is not LP64 friendly. it also does not perform 30 * try-and-error for region size. 31 */ 32 #include "namespace.h" 33 #include <sys/types.h> 34 #include <sys/ioctl.h> 35 #include <sys/socket.h> 36 #include <net/if.h> 37 #include <sys/param.h> 38 #include <net/route.h> 39 #include <sys/sysctl.h> 40 #include <net/if_dl.h> 41 42 #include <errno.h> 43 #include <ifaddrs.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include "un-namespace.h" 47 48 #if !defined(AF_LINK) 49 #define SA_LEN(sa) sizeof(struct sockaddr) 50 #endif 51 52 #if !defined(SA_LEN) 53 #define SA_LEN(sa) (sa)->sa_len 54 #endif 55 56 #define SA_RLEN(sa) RT_ROUNDUP((sa)->sa_len) 57 58 #ifndef ALIGNBYTES 59 /* 60 * On systems with a routing socket, ALIGNBYTES should match the value 61 * that the kernel uses when building the messages. 62 */ 63 #define ALIGNBYTES XXX 64 #endif 65 #ifndef ALIGN 66 #define ALIGN(p) (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES) 67 #endif 68 69 #define MAX_SYSCTL_TRY 5 70 71 int 72 getifaddrs(struct ifaddrs **pif) 73 { 74 int icnt = 1; 75 int dcnt = 0; 76 int ncnt = 0; 77 int ntry = 0; 78 int mib[6]; 79 size_t needed; 80 char *buf; 81 char *next; 82 struct ifaddrs *cif = NULL; 83 char *p, *p0; 84 struct rt_msghdr *rtm; 85 struct if_msghdr *ifm; 86 struct ifa_msghdr *ifam; 87 struct sockaddr_dl *dl; 88 struct sockaddr *sa; 89 struct ifaddrs *ifa, *ift; 90 u_short idx = 0; 91 int i; 92 size_t len, alen; 93 char *data; 94 char *names; 95 96 mib[0] = CTL_NET; 97 mib[1] = PF_ROUTE; 98 mib[2] = 0; /* protocol */ 99 mib[3] = 0; /* wildcard address family */ 100 mib[4] = NET_RT_IFLIST; 101 mib[5] = 0; /* no flags */ 102 do { 103 /* 104 * We'll try to get addresses several times in case that 105 * the number of addresses is unexpectedly increased during 106 * the two sysctl calls. This should rarely happen, but we'll 107 * try to do our best for applications that assume success of 108 * this library (which should usually be the case). 109 * Portability note: since FreeBSD does not add margin of 110 * memory at the first sysctl, the possibility of failure on 111 * the second sysctl call is a bit higher. 112 */ 113 114 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 115 return (-1); 116 if ((buf = malloc(needed)) == NULL) 117 return (-1); 118 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 119 if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) { 120 free(buf); 121 return (-1); 122 } 123 free(buf); 124 buf = NULL; 125 } 126 } while (buf == NULL); 127 128 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 129 rtm = (struct rt_msghdr *)(void *)next; 130 if (rtm->rtm_version != RTM_VERSION) 131 continue; 132 switch (rtm->rtm_type) { 133 case RTM_IFINFO: 134 ifm = (struct if_msghdr *)(void *)rtm; 135 if (ifm->ifm_addrs & RTA_IFP) { 136 idx = ifm->ifm_index; 137 ++icnt; 138 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 139 dcnt += SA_RLEN((struct sockaddr *)(void*)dl) + 140 ALIGNBYTES; 141 dcnt += sizeof(ifm->ifm_data); 142 ncnt += dl->sdl_nlen + 1; 143 } else 144 idx = 0; 145 break; 146 147 case RTM_NEWADDR: 148 ifam = (struct ifa_msghdr *)(void *)rtm; 149 if (idx && ifam->ifam_index != idx) 150 abort(); /* this cannot happen */ 151 152 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) 153 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 154 break; 155 p = (char *)(void *)(ifam + 1); 156 ++icnt; 157 /* Scan to look for length of address */ 158 alen = 0; 159 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 160 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 161 == 0) 162 continue; 163 sa = (struct sockaddr *)(void *)p; 164 len = SA_RLEN(sa); 165 if (i == RTAX_IFA) { 166 alen = len; 167 break; 168 } 169 p += len; 170 } 171 for (p = p0, i = 0; i < RTAX_MAX; i++) { 172 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 173 == 0) 174 continue; 175 sa = (struct sockaddr *)(void *)p; 176 len = SA_RLEN(sa); 177 if (i == RTAX_NETMASK && SA_LEN(sa) == 0) 178 dcnt += alen; 179 else 180 dcnt += len; 181 p += len; 182 } 183 break; 184 } 185 } 186 187 if (icnt + dcnt + ncnt == 1) { 188 *pif = NULL; 189 free(buf); 190 return (0); 191 } 192 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt); 193 if (data == NULL) { 194 free(buf); 195 return(-1); 196 } 197 198 ifa = (struct ifaddrs *)(void *)data; 199 data += sizeof(struct ifaddrs) * icnt; 200 names = data + dcnt; 201 202 memset(ifa, 0, sizeof(struct ifaddrs) * icnt); 203 ift = ifa; 204 205 idx = 0; 206 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 207 rtm = (struct rt_msghdr *)(void *)next; 208 if (rtm->rtm_version != RTM_VERSION) 209 continue; 210 switch (rtm->rtm_type) { 211 case RTM_IFINFO: 212 ifm = (struct if_msghdr *)(void *)rtm; 213 if (ifm->ifm_addrs & RTA_IFP) { 214 idx = ifm->ifm_index; 215 dl = (struct sockaddr_dl *)(void *)(ifm + 1); 216 217 cif = ift; 218 ift->ifa_name = names; 219 ift->ifa_flags = (int)ifm->ifm_flags; 220 memcpy(names, dl->sdl_data, 221 (size_t)dl->sdl_nlen); 222 names[dl->sdl_nlen] = 0; 223 names += dl->sdl_nlen + 1; 224 225 ift->ifa_addr = (struct sockaddr *)(void *)data; 226 memcpy(data, dl, 227 (size_t)SA_LEN((struct sockaddr *) 228 (void *)dl)); 229 data += SA_RLEN((struct sockaddr *)(void *)dl); 230 231 /* ifm_data needs to be aligned */ 232 ift->ifa_data = data = (void *)ALIGN(data); 233 memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data)); 234 data += sizeof(ifm->ifm_data); 235 ift = (ift->ifa_next = ift + 1); 236 } else 237 idx = 0; 238 break; 239 240 case RTM_NEWADDR: 241 ifam = (struct ifa_msghdr *)(void *)rtm; 242 if (idx && ifam->ifam_index != idx) 243 abort(); /* this cannot happen */ 244 245 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 246 break; 247 ift->ifa_name = cif->ifa_name; 248 ift->ifa_flags = cif->ifa_flags; 249 ift->ifa_data = NULL; 250 p = (char *)(void *)(ifam + 1); 251 /* Scan to look for length of address */ 252 alen = 0; 253 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 254 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 255 == 0) 256 continue; 257 sa = (struct sockaddr *)(void *)p; 258 len = SA_RLEN(sa); 259 if (i == RTAX_IFA) { 260 alen = len; 261 break; 262 } 263 p += len; 264 } 265 for (p = p0, i = 0; i < RTAX_MAX; i++) { 266 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 267 == 0) 268 continue; 269 sa = (struct sockaddr *)(void *)p; 270 len = SA_RLEN(sa); 271 switch (i) { 272 case RTAX_IFA: 273 ift->ifa_addr = 274 (struct sockaddr *)(void *)data; 275 memcpy(data, p, len); 276 data += len; 277 break; 278 279 case RTAX_NETMASK: 280 ift->ifa_netmask = 281 (struct sockaddr *)(void *)data; 282 if (SA_LEN(sa) == 0) { 283 memset(data, 0, alen); 284 data += alen; 285 break; 286 } 287 memcpy(data, p, len); 288 data += len; 289 break; 290 291 case RTAX_BRD: 292 ift->ifa_broadaddr = 293 (struct sockaddr *)(void *)data; 294 memcpy(data, p, len); 295 data += len; 296 break; 297 } 298 p += len; 299 } 300 301 ift = (ift->ifa_next = ift + 1); 302 break; 303 } 304 } 305 306 free(buf); 307 if (--ift >= ifa) { 308 ift->ifa_next = NULL; 309 *pif = ifa; 310 } else { 311 *pif = NULL; 312 free(ifa); 313 } 314 return (0); 315 } 316 317 void 318 freeifaddrs(struct ifaddrs *ifp) 319 { 320 321 free(ifp); 322 } 323