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 <sys/cdefs.h> 35 #include "namespace.h" 36 #include <sys/types.h> 37 #include <sys/ioctl.h> 38 #include <sys/socket.h> 39 #include <net/if.h> 40 #ifdef NET_RT_IFLIST 41 #include <sys/param.h> 42 #include <net/route.h> 43 #include <sys/sysctl.h> 44 #include <net/if_dl.h> 45 #endif 46 47 #include <errno.h> 48 #include <ifaddrs.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include "un-namespace.h" 52 53 #if !defined(AF_LINK) 54 #define SA_LEN(sa) sizeof(struct sockaddr) 55 #endif 56 57 #if !defined(SA_LEN) 58 #define SA_LEN(sa) (sa)->sa_len 59 #endif 60 61 #define SALIGN (sizeof(long) - 1) 62 #define SA_RLEN(sa) ((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1)) 63 64 #ifndef ALIGNBYTES 65 /* 66 * On systems with a routing socket, ALIGNBYTES should match the value 67 * that the kernel uses when building the messages. 68 */ 69 #define ALIGNBYTES XXX 70 #endif 71 #ifndef ALIGN 72 #define ALIGN(p) (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES) 73 #endif 74 75 #define MAX_SYSCTL_TRY 5 76 77 int 78 getifaddrs(struct ifaddrs **pif) 79 { 80 int icnt = 1; 81 int dcnt = 0; 82 int ncnt = 0; 83 int ntry = 0; 84 int mib[6]; 85 size_t needed; 86 char *buf; 87 char *next; 88 struct ifaddrs *cif; 89 char *p, *p0; 90 struct rt_msghdr *rtm; 91 struct if_msghdrl *ifm; 92 struct ifa_msghdrl *ifam; 93 struct sockaddr_dl *dl; 94 struct sockaddr *sa; 95 struct ifaddrs *ifa, *ift; 96 struct if_data *if_data; 97 u_short idx = 0; 98 int i; 99 size_t len, alen; 100 char *data; 101 char *names; 102 103 mib[0] = CTL_NET; 104 mib[1] = PF_ROUTE; 105 mib[2] = 0; /* protocol */ 106 mib[3] = 0; /* wildcard address family */ 107 mib[4] = NET_RT_IFLISTL;/* extra fields for extensible msghdr structs */ 108 mib[5] = 0; /* no flags */ 109 do { 110 /* 111 * We'll try to get addresses several times in case that 112 * the number of addresses is unexpectedly increased during 113 * the two sysctl calls. This should rarely happen, but we'll 114 * try to do our best for applications that assume success of 115 * this library (which should usually be the case). 116 * Portability note: since FreeBSD does not add margin of 117 * memory at the first sysctl, the possibility of failure on 118 * the second sysctl call is a bit higher. 119 */ 120 121 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 122 return (-1); 123 if ((buf = malloc(needed)) == NULL) 124 return (-1); 125 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 126 if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) { 127 free(buf); 128 return (-1); 129 } 130 free(buf); 131 buf = NULL; 132 } 133 } while (buf == NULL); 134 135 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 136 rtm = (struct rt_msghdr *)(void *)next; 137 if (rtm->rtm_version != RTM_VERSION) 138 continue; 139 switch (rtm->rtm_type) { 140 case RTM_IFINFO: 141 ifm = (struct if_msghdrl *)(void *)rtm; 142 if (ifm->ifm_addrs & RTA_IFP) { 143 idx = ifm->ifm_index; 144 ++icnt; 145 if_data = IF_MSGHDRL_IFM_DATA(ifm); 146 dcnt += if_data->ifi_datalen; 147 dl = (struct sockaddr_dl *)IF_MSGHDRL_RTA(ifm); 148 dcnt += SA_RLEN((struct sockaddr *)(void*)dl) + 149 ALIGNBYTES; 150 ncnt += dl->sdl_nlen + 1; 151 } else 152 idx = 0; 153 break; 154 155 case RTM_NEWADDR: 156 ifam = (struct ifa_msghdrl *)(void *)rtm; 157 if (idx && ifam->ifam_index != idx) 158 abort(); /* this cannot happen */ 159 160 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) 161 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 162 break; 163 p = (char *)IFA_MSGHDRL_RTA(ifam); 164 ++icnt; 165 if_data = IFA_MSGHDRL_IFAM_DATA(ifam); 166 dcnt += if_data->ifi_datalen + ALIGNBYTES; 167 168 /* Scan to look for length of address */ 169 alen = 0; 170 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 171 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 172 == 0) 173 continue; 174 sa = (struct sockaddr *)(void *)p; 175 len = SA_RLEN(sa); 176 if (i == RTAX_IFA) { 177 alen = len; 178 break; 179 } 180 p += len; 181 } 182 for (p = p0, i = 0; i < RTAX_MAX; i++) { 183 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 184 == 0) 185 continue; 186 sa = (struct sockaddr *)(void *)p; 187 len = SA_RLEN(sa); 188 if (i == RTAX_NETMASK && SA_LEN(sa) == 0) 189 dcnt += alen; 190 else 191 dcnt += len; 192 p += len; 193 } 194 break; 195 } 196 } 197 198 if (icnt + dcnt + ncnt == 1) { 199 *pif = NULL; 200 free(buf); 201 return (0); 202 } 203 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt); 204 if (data == NULL) { 205 free(buf); 206 return(-1); 207 } 208 209 ifa = (struct ifaddrs *)(void *)data; 210 data += sizeof(struct ifaddrs) * icnt; 211 names = data + dcnt; 212 213 memset(ifa, 0, sizeof(struct ifaddrs) * icnt); 214 ift = ifa; 215 216 idx = 0; 217 cif = NULL; 218 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 219 rtm = (struct rt_msghdr *)(void *)next; 220 if (rtm->rtm_version != RTM_VERSION) 221 continue; 222 switch (rtm->rtm_type) { 223 case RTM_IFINFO: 224 ifm = (struct if_msghdrl *)(void *)rtm; 225 if ((ifm->ifm_addrs & RTA_IFP) == 0) { 226 idx = 0; 227 break; 228 } 229 230 idx = ifm->ifm_index; 231 dl = (struct sockaddr_dl *)IF_MSGHDRL_RTA(ifm); 232 233 cif = ift; 234 ift->ifa_name = names; 235 ift->ifa_flags = (int)ifm->ifm_flags; 236 memcpy(names, dl->sdl_data, (size_t)dl->sdl_nlen); 237 names[dl->sdl_nlen] = 0; 238 names += dl->sdl_nlen + 1; 239 240 ift->ifa_addr = (struct sockaddr *)(void *)data; 241 memcpy(data, dl, (size_t)SA_LEN((struct sockaddr *) 242 (void *)dl)); 243 data += SA_RLEN((struct sockaddr *)(void *)dl); 244 245 if_data = IF_MSGHDRL_IFM_DATA(ifm); 246 /* ifm_data needs to be aligned */ 247 ift->ifa_data = data = (void *)ALIGN(data); 248 memcpy(data, if_data, if_data->ifi_datalen); 249 data += if_data->ifi_datalen; 250 251 ift = (ift->ifa_next = ift + 1); 252 break; 253 254 case RTM_NEWADDR: 255 ifam = (struct ifa_msghdrl *)(void *)rtm; 256 if (idx && ifam->ifam_index != idx) 257 abort(); /* this cannot happen */ 258 259 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 260 break; 261 ift->ifa_name = cif->ifa_name; 262 ift->ifa_flags = cif->ifa_flags; 263 ift->ifa_data = NULL; 264 265 p = (char *)IFA_MSGHDRL_RTA(ifam); 266 /* Scan to look for length of address */ 267 alen = 0; 268 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 269 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 270 == 0) 271 continue; 272 sa = (struct sockaddr *)(void *)p; 273 len = SA_RLEN(sa); 274 if (i == RTAX_IFA) { 275 alen = len; 276 break; 277 } 278 p += len; 279 } 280 for (p = p0, i = 0; i < RTAX_MAX; i++) { 281 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 282 == 0) 283 continue; 284 sa = (struct sockaddr *)(void *)p; 285 len = SA_RLEN(sa); 286 switch (i) { 287 case RTAX_IFA: 288 ift->ifa_addr = 289 (struct sockaddr *)(void *)data; 290 memcpy(data, p, len); 291 data += len; 292 break; 293 294 case RTAX_NETMASK: 295 ift->ifa_netmask = 296 (struct sockaddr *)(void *)data; 297 if (SA_LEN(sa) == 0) { 298 memset(data, 0, alen); 299 data += alen; 300 break; 301 } 302 memcpy(data, p, len); 303 data += len; 304 break; 305 306 case RTAX_BRD: 307 ift->ifa_broadaddr = 308 (struct sockaddr *)(void *)data; 309 memcpy(data, p, len); 310 data += len; 311 break; 312 } 313 p += len; 314 } 315 316 if_data = IFA_MSGHDRL_IFAM_DATA(ifam); 317 /* ifam_data needs to be aligned */ 318 ift->ifa_data = data = (void *)ALIGN(data); 319 memcpy(data, if_data, if_data->ifi_datalen); 320 data += if_data->ifi_datalen; 321 322 ift = (ift->ifa_next = ift + 1); 323 break; 324 } 325 } 326 327 free(buf); 328 329 if (--ift >= ifa) { 330 ift->ifa_next = NULL; 331 *pif = ifa; 332 } else { 333 *pif = NULL; 334 free(ifa); 335 } 336 return (0); 337 } 338 339 void 340 freeifaddrs(struct ifaddrs *ifp) 341 { 342 343 free(ifp); 344 } 345