1 /* $OpenBSD: getifaddrs.c,v 1.9 2002/08/09 06:12:25 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 #include <sys/types.h> 29 #include <sys/ioctl.h> 30 #include <sys/socket.h> 31 #include <net/if.h> 32 #include <sys/param.h> 33 #include <net/route.h> 34 #include <sys/sysctl.h> 35 #include <net/if_dl.h> 36 37 #include <errno.h> 38 #include <ifaddrs.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <unistd.h> 42 43 #define SALIGN (sizeof(long) - 1) 44 #define SA_RLEN(sa) ((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1)) 45 46 int 47 getifaddrs(struct ifaddrs **pif) 48 { 49 int icnt = 1; 50 int dcnt = 0; 51 int ncnt = 0; 52 int mib[6]; 53 size_t needed; 54 char *buf; 55 char *next; 56 struct ifaddrs *cif = 0; 57 char *p, *p0; 58 struct rt_msghdr *rtm; 59 struct if_msghdr *ifm; 60 struct ifa_msghdr *ifam; 61 struct sockaddr_dl *dl; 62 struct sockaddr *sa; 63 u_short index = 0; 64 size_t len, alen; 65 struct ifaddrs *ifa, *ift; 66 int i; 67 char *data; 68 char *names; 69 70 mib[0] = CTL_NET; 71 mib[1] = PF_ROUTE; 72 mib[2] = 0; /* protocol */ 73 mib[3] = 0; /* wildcard address family */ 74 mib[4] = NET_RT_IFLIST; 75 mib[5] = 0; /* no flags */ 76 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 77 return (-1); 78 if ((buf = malloc(needed)) == NULL) 79 return (-1); 80 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 81 free(buf); 82 return (-1); 83 } 84 85 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 86 rtm = (struct rt_msghdr *)next; 87 if (rtm->rtm_version != RTM_VERSION) 88 continue; 89 switch (rtm->rtm_type) { 90 case RTM_IFINFO: 91 ifm = (struct if_msghdr *)rtm; 92 if (ifm->ifm_addrs & RTA_IFP) { 93 index = ifm->ifm_index; 94 ++icnt; 95 dl = (struct sockaddr_dl *)(ifm + 1); 96 dcnt += SA_RLEN((struct sockaddr *)dl) + 97 ALIGNBYTES; 98 dcnt += sizeof(ifm->ifm_data); 99 ncnt += dl->sdl_nlen + 1; 100 } else 101 index = 0; 102 break; 103 104 case RTM_NEWADDR: 105 ifam = (struct ifa_msghdr *)rtm; 106 if (index && ifam->ifam_index != index) 107 abort(); /* XXX abort illegal in library */ 108 109 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) 110 if (index == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 111 break; 112 p = (char *)(ifam + 1); 113 ++icnt; 114 /* Scan to look for length of address */ 115 alen = 0; 116 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 117 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 118 == 0) 119 continue; 120 sa = (struct sockaddr *)p; 121 len = SA_RLEN(sa); 122 if (i == RTAX_IFA) { 123 alen = len; 124 break; 125 } 126 p += len; 127 } 128 for (p = p0, i = 0; i < RTAX_MAX; i++) { 129 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 130 == 0) 131 continue; 132 sa = (struct sockaddr *)p; 133 len = SA_RLEN(sa); 134 if (i == RTAX_NETMASK && sa->sa_len == 0) 135 dcnt += alen; 136 else 137 dcnt += len; 138 p += len; 139 } 140 break; 141 } 142 } 143 144 if (icnt + dcnt + ncnt == 1) { 145 *pif = NULL; 146 free(buf); 147 return (0); 148 } 149 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt); 150 if (data == NULL) { 151 free(buf); 152 return(-1); 153 } 154 155 ifa = (struct ifaddrs *)data; 156 data += sizeof(struct ifaddrs) * icnt; 157 names = data + dcnt; 158 159 memset(ifa, 0, sizeof(struct ifaddrs) * icnt); 160 ift = ifa; 161 162 index = 0; 163 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 164 rtm = (struct rt_msghdr *)next; 165 if (rtm->rtm_version != RTM_VERSION) 166 continue; 167 switch (rtm->rtm_type) { 168 case RTM_IFINFO: 169 ifm = (struct if_msghdr *)rtm; 170 if (ifm->ifm_addrs & RTA_IFP) { 171 index = ifm->ifm_index; 172 dl = (struct sockaddr_dl *)(ifm + 1); 173 174 cif = ift; 175 ift->ifa_name = names; 176 ift->ifa_flags = (int)ifm->ifm_flags; 177 memcpy(names, dl->sdl_data, dl->sdl_nlen); 178 names[dl->sdl_nlen] = 0; 179 names += dl->sdl_nlen + 1; 180 181 ift->ifa_addr = (struct sockaddr *)data; 182 memcpy(data, dl, 183 ((struct sockaddr *)dl)->sa_len); 184 data += SA_RLEN((struct sockaddr *)dl); 185 186 /* ifm_data needs to be aligned */ 187 ift->ifa_data = data = (void *)ALIGN(data); 188 memcpy(data, &ifm->ifm_data, sizeof(ifm->ifm_data)); 189 data += sizeof(ifm->ifm_data); 190 191 ift = (ift->ifa_next = ift + 1); 192 } else 193 index = 0; 194 break; 195 196 case RTM_NEWADDR: 197 ifam = (struct ifa_msghdr *)rtm; 198 if (index && ifam->ifam_index != index) 199 abort(); /* XXX abort illegal in library */ 200 201 if (index == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 202 break; 203 ift->ifa_name = cif->ifa_name; 204 ift->ifa_flags = cif->ifa_flags; 205 ift->ifa_data = NULL; 206 p = (char *)(ifam + 1); 207 /* Scan to look for length of address */ 208 alen = 0; 209 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 210 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 211 == 0) 212 continue; 213 sa = (struct sockaddr *)p; 214 len = SA_RLEN(sa); 215 if (i == RTAX_IFA) { 216 alen = len; 217 break; 218 } 219 p += len; 220 } 221 for (p = p0, i = 0; i < RTAX_MAX; i++) { 222 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 223 == 0) 224 continue; 225 sa = (struct sockaddr *)p; 226 len = SA_RLEN(sa); 227 switch (i) { 228 case RTAX_IFA: 229 ift->ifa_addr = (struct sockaddr *)data; 230 memcpy(data, p, len); 231 data += len; 232 break; 233 234 case RTAX_NETMASK: 235 ift->ifa_netmask = 236 (struct sockaddr *)data; 237 if (sa->sa_len == 0) { 238 memset(data, 0, alen); 239 data += alen; 240 break; 241 } 242 memcpy(data, p, len); 243 data += len; 244 break; 245 246 case RTAX_BRD: 247 ift->ifa_broadaddr = 248 (struct sockaddr *)data; 249 memcpy(data, p, len); 250 data += len; 251 break; 252 } 253 p += len; 254 } 255 256 257 ift = (ift->ifa_next = ift + 1); 258 break; 259 } 260 } 261 262 free(buf); 263 if (--ift >= ifa) { 264 ift->ifa_next = NULL; 265 *pif = ifa; 266 } else { 267 *pif = NULL; 268 free(ifa); 269 } 270 return (0); 271 } 272 273 void 274 freeifaddrs(struct ifaddrs *ifp) 275 { 276 free(ifp); 277 } 278