1 /* $KAME: getifaddrs.c,v 1.9 2001/08/20 02:31:20 itojun Exp $ */ 2 3 /*- 4 * SPDX-License-Identifier: BSD-1-Clause 5 * 6 * Copyright (c) 1995, 1999 7 * Berkeley Software Design, Inc. All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * BSDI getifaddrs.c,v 2.12 2000/02/23 14:51:59 dab Exp 28 */ 29 /* 30 * NOTE: SIOCGIFCONF case is not LP64 friendly. it also does not perform 31 * try-and-error for region size. 32 */ 33 34 #include "namespace.h" 35 #include <sys/types.h> 36 #include <sys/ioctl.h> 37 #include <sys/socket.h> 38 #include <net/if.h> 39 #ifdef NET_RT_IFLIST 40 #include <sys/param.h> 41 #include <net/route.h> 42 #include <sys/sysctl.h> 43 #include <net/if_dl.h> 44 #endif 45 46 #include <errno.h> 47 #include <ifaddrs.h> 48 #include <stdlib.h> 49 #include <string.h> 50 #include "un-namespace.h" 51 52 #if !defined(AF_LINK) 53 #define SA_LEN(sa) sizeof(struct sockaddr) 54 #endif 55 56 #if !defined(SA_LEN) 57 #define SA_LEN(sa) (sa)->sa_len 58 #endif 59 60 #define SALIGN (sizeof(long) - 1) 61 #define SA_RLEN(sa) ((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1)) 62 63 #ifndef ALIGNBYTES 64 /* 65 * On systems with a routing socket, ALIGNBYTES should match the value 66 * that the kernel uses when building the messages. 67 */ 68 #define ALIGNBYTES XXX 69 #endif 70 #ifndef ALIGN 71 #define ALIGN(p) (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES) 72 #endif 73 74 #define MAX_SYSCTL_TRY 5 75 76 int 77 getifaddrs(struct ifaddrs **pif) 78 { 79 int icnt = 1; 80 int dcnt = 0; 81 int ncnt = 0; 82 int ntry = 0; 83 int mib[6]; 84 size_t needed; 85 char *buf; 86 char *next; 87 struct ifaddrs *cif; 88 char *p, *p0; 89 struct rt_msghdr *rtm; 90 struct if_msghdrl *ifm; 91 struct ifa_msghdrl *ifam; 92 struct sockaddr_dl *dl; 93 struct sockaddr *sa; 94 struct ifaddrs *ifa, *ift; 95 struct if_data *if_data; 96 u_short idx = 0; 97 int i; 98 size_t len, alen; 99 char *data; 100 char *names; 101 102 mib[0] = CTL_NET; 103 mib[1] = PF_ROUTE; 104 mib[2] = 0; /* protocol */ 105 mib[3] = 0; /* wildcard address family */ 106 mib[4] = NET_RT_IFLISTL;/* extra fields for extensible msghdr structs */ 107 mib[5] = 0; /* no flags */ 108 do { 109 /* 110 * We'll try to get addresses several times in case that 111 * the number of addresses is unexpectedly increased during 112 * the two sysctl calls. This should rarely happen, but we'll 113 * try to do our best for applications that assume success of 114 * this library (which should usually be the case). 115 * Portability note: since FreeBSD does not add margin of 116 * memory at the first sysctl, the possibility of failure on 117 * the second sysctl call is a bit higher. 118 */ 119 120 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 121 return (-1); 122 if ((buf = malloc(needed)) == NULL) 123 return (-1); 124 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 125 if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) { 126 free(buf); 127 return (-1); 128 } 129 free(buf); 130 buf = NULL; 131 } 132 } while (buf == NULL); 133 134 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 135 rtm = (struct rt_msghdr *)(void *)next; 136 if (rtm->rtm_version != RTM_VERSION) 137 continue; 138 switch (rtm->rtm_type) { 139 case RTM_IFINFO: 140 ifm = (struct if_msghdrl *)(void *)rtm; 141 if (ifm->ifm_addrs & RTA_IFP) { 142 idx = ifm->ifm_index; 143 ++icnt; 144 if_data = IF_MSGHDRL_IFM_DATA(ifm); 145 dcnt += if_data->ifi_datalen; 146 dl = (struct sockaddr_dl *)IF_MSGHDRL_RTA(ifm); 147 dcnt += SA_RLEN((struct sockaddr *)(void*)dl) + 148 ALIGNBYTES; 149 ncnt += dl->sdl_nlen + 1; 150 } else 151 idx = 0; 152 break; 153 154 case RTM_NEWADDR: 155 ifam = (struct ifa_msghdrl *)(void *)rtm; 156 if (idx && ifam->ifam_index != idx) 157 abort(); /* this cannot happen */ 158 159 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) 160 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 161 break; 162 p = (char *)IFA_MSGHDRL_RTA(ifam); 163 ++icnt; 164 if_data = IFA_MSGHDRL_IFAM_DATA(ifam); 165 dcnt += if_data->ifi_datalen + ALIGNBYTES; 166 167 /* Scan to look for length of address */ 168 alen = 0; 169 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 170 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 171 == 0) 172 continue; 173 sa = (struct sockaddr *)(void *)p; 174 len = SA_RLEN(sa); 175 if (i == RTAX_IFA) { 176 alen = len; 177 break; 178 } 179 p += len; 180 } 181 for (p = p0, i = 0; i < RTAX_MAX; i++) { 182 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 183 == 0) 184 continue; 185 sa = (struct sockaddr *)(void *)p; 186 len = SA_RLEN(sa); 187 if (i == RTAX_NETMASK && SA_LEN(sa) == 0) 188 dcnt += alen; 189 else 190 dcnt += len; 191 p += len; 192 } 193 break; 194 } 195 } 196 197 if (icnt + dcnt + ncnt == 1) { 198 *pif = NULL; 199 free(buf); 200 return (0); 201 } 202 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt); 203 if (data == NULL) { 204 free(buf); 205 return(-1); 206 } 207 208 ifa = (struct ifaddrs *)(void *)data; 209 data += sizeof(struct ifaddrs) * icnt; 210 names = data + dcnt; 211 212 memset(ifa, 0, sizeof(struct ifaddrs) * icnt); 213 ift = ifa; 214 215 idx = 0; 216 cif = NULL; 217 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 218 rtm = (struct rt_msghdr *)(void *)next; 219 if (rtm->rtm_version != RTM_VERSION) 220 continue; 221 switch (rtm->rtm_type) { 222 case RTM_IFINFO: 223 ifm = (struct if_msghdrl *)(void *)rtm; 224 if ((ifm->ifm_addrs & RTA_IFP) == 0) { 225 idx = 0; 226 break; 227 } 228 229 idx = ifm->ifm_index; 230 dl = (struct sockaddr_dl *)IF_MSGHDRL_RTA(ifm); 231 232 cif = ift; 233 ift->ifa_name = names; 234 ift->ifa_flags = (int)ifm->ifm_flags; 235 memcpy(names, dl->sdl_data, (size_t)dl->sdl_nlen); 236 names[dl->sdl_nlen] = 0; 237 names += dl->sdl_nlen + 1; 238 239 ift->ifa_addr = (struct sockaddr *)(void *)data; 240 memcpy(data, dl, (size_t)SA_LEN((struct sockaddr *) 241 (void *)dl)); 242 data += SA_RLEN((struct sockaddr *)(void *)dl); 243 244 if_data = IF_MSGHDRL_IFM_DATA(ifm); 245 /* ifm_data needs to be aligned */ 246 ift->ifa_data = data = (void *)ALIGN(data); 247 memcpy(data, if_data, if_data->ifi_datalen); 248 data += if_data->ifi_datalen; 249 250 ift = (ift->ifa_next = ift + 1); 251 break; 252 253 case RTM_NEWADDR: 254 ifam = (struct ifa_msghdrl *)(void *)rtm; 255 if (idx && ifam->ifam_index != idx) 256 abort(); /* this cannot happen */ 257 258 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 259 break; 260 ift->ifa_name = cif->ifa_name; 261 ift->ifa_flags = cif->ifa_flags; 262 ift->ifa_data = NULL; 263 264 p = (char *)IFA_MSGHDRL_RTA(ifam); 265 /* Scan to look for length of address */ 266 alen = 0; 267 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 268 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 269 == 0) 270 continue; 271 sa = (struct sockaddr *)(void *)p; 272 len = SA_RLEN(sa); 273 if (i == RTAX_IFA) { 274 alen = len; 275 break; 276 } 277 p += len; 278 } 279 for (p = p0, i = 0; i < RTAX_MAX; i++) { 280 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 281 == 0) 282 continue; 283 sa = (struct sockaddr *)(void *)p; 284 len = SA_RLEN(sa); 285 switch (i) { 286 case RTAX_IFA: 287 ift->ifa_addr = 288 (struct sockaddr *)(void *)data; 289 memcpy(data, p, len); 290 data += len; 291 break; 292 293 case RTAX_NETMASK: 294 ift->ifa_netmask = 295 (struct sockaddr *)(void *)data; 296 if (SA_LEN(sa) == 0) { 297 memset(data, 0, alen); 298 data += alen; 299 break; 300 } 301 memcpy(data, p, len); 302 data += len; 303 break; 304 305 case RTAX_BRD: 306 ift->ifa_broadaddr = 307 (struct sockaddr *)(void *)data; 308 memcpy(data, p, len); 309 data += len; 310 break; 311 } 312 p += len; 313 } 314 315 if_data = IFA_MSGHDRL_IFAM_DATA(ifam); 316 /* ifam_data needs to be aligned */ 317 ift->ifa_data = data = (void *)ALIGN(data); 318 memcpy(data, if_data, if_data->ifi_datalen); 319 data += if_data->ifi_datalen; 320 321 ift = (ift->ifa_next = ift + 1); 322 break; 323 } 324 } 325 326 free(buf); 327 328 if (--ift >= ifa) { 329 ift->ifa_next = NULL; 330 *pif = ifa; 331 } else { 332 *pif = NULL; 333 free(ifa); 334 } 335 return (0); 336 } 337 338 void 339 freeifaddrs(struct ifaddrs *ifp) 340 { 341 342 free(ifp); 343 } 344