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 __FBSDID("$FreeBSD$"); 36 37 #include "namespace.h" 38 #include <sys/types.h> 39 #include <sys/ioctl.h> 40 #include <sys/socket.h> 41 #include <net/if.h> 42 #ifdef NET_RT_IFLIST 43 #include <sys/param.h> 44 #include <net/route.h> 45 #include <sys/sysctl.h> 46 #include <net/if_dl.h> 47 #endif 48 49 #include <errno.h> 50 #include <ifaddrs.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include "un-namespace.h" 54 55 #if !defined(AF_LINK) 56 #define SA_LEN(sa) sizeof(struct sockaddr) 57 #endif 58 59 #if !defined(SA_LEN) 60 #define SA_LEN(sa) (sa)->sa_len 61 #endif 62 63 #define SALIGN (sizeof(long) - 1) 64 #define SA_RLEN(sa) ((sa)->sa_len ? (((sa)->sa_len + SALIGN) & ~SALIGN) : (SALIGN + 1)) 65 66 #ifndef ALIGNBYTES 67 /* 68 * On systems with a routing socket, ALIGNBYTES should match the value 69 * that the kernel uses when building the messages. 70 */ 71 #define ALIGNBYTES XXX 72 #endif 73 #ifndef ALIGN 74 #define ALIGN(p) (((u_long)(p) + ALIGNBYTES) &~ ALIGNBYTES) 75 #endif 76 77 #define MAX_SYSCTL_TRY 5 78 79 int 80 getifaddrs(struct ifaddrs **pif) 81 { 82 int icnt = 1; 83 int dcnt = 0; 84 int ncnt = 0; 85 int ntry = 0; 86 int mib[6]; 87 size_t needed; 88 char *buf; 89 char *next; 90 struct ifaddrs *cif; 91 char *p, *p0; 92 struct rt_msghdr *rtm; 93 struct if_msghdrl *ifm; 94 struct ifa_msghdrl *ifam; 95 struct sockaddr_dl *dl; 96 struct sockaddr *sa; 97 struct ifaddrs *ifa, *ift; 98 struct if_data *if_data; 99 u_short idx = 0; 100 int i; 101 size_t len, alen; 102 char *data; 103 char *names; 104 105 mib[0] = CTL_NET; 106 mib[1] = PF_ROUTE; 107 mib[2] = 0; /* protocol */ 108 mib[3] = 0; /* wildcard address family */ 109 mib[4] = NET_RT_IFLISTL;/* extra fields for extensible msghdr structs */ 110 mib[5] = 0; /* no flags */ 111 do { 112 /* 113 * We'll try to get addresses several times in case that 114 * the number of addresses is unexpectedly increased during 115 * the two sysctl calls. This should rarely happen, but we'll 116 * try to do our best for applications that assume success of 117 * this library (which should usually be the case). 118 * Portability note: since FreeBSD does not add margin of 119 * memory at the first sysctl, the possibility of failure on 120 * the second sysctl call is a bit higher. 121 */ 122 123 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 124 return (-1); 125 if ((buf = malloc(needed)) == NULL) 126 return (-1); 127 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { 128 if (errno != ENOMEM || ++ntry >= MAX_SYSCTL_TRY) { 129 free(buf); 130 return (-1); 131 } 132 free(buf); 133 buf = NULL; 134 } 135 } while (buf == NULL); 136 137 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 138 rtm = (struct rt_msghdr *)(void *)next; 139 if (rtm->rtm_version != RTM_VERSION) 140 continue; 141 switch (rtm->rtm_type) { 142 case RTM_IFINFO: 143 ifm = (struct if_msghdrl *)(void *)rtm; 144 if (ifm->ifm_addrs & RTA_IFP) { 145 idx = ifm->ifm_index; 146 ++icnt; 147 if_data = IF_MSGHDRL_IFM_DATA(ifm); 148 dcnt += if_data->ifi_datalen; 149 dl = (struct sockaddr_dl *)IF_MSGHDRL_RTA(ifm); 150 dcnt += SA_RLEN((struct sockaddr *)(void*)dl) + 151 ALIGNBYTES; 152 ncnt += dl->sdl_nlen + 1; 153 } else 154 idx = 0; 155 break; 156 157 case RTM_NEWADDR: 158 ifam = (struct ifa_msghdrl *)(void *)rtm; 159 if (idx && ifam->ifam_index != idx) 160 abort(); /* this cannot happen */ 161 162 #define RTA_MASKS (RTA_NETMASK | RTA_IFA | RTA_BRD) 163 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 164 break; 165 p = (char *)IFA_MSGHDRL_RTA(ifam); 166 ++icnt; 167 if_data = IFA_MSGHDRL_IFAM_DATA(ifam); 168 dcnt += if_data->ifi_datalen + ALIGNBYTES; 169 170 /* Scan to look for length of address */ 171 alen = 0; 172 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 173 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 174 == 0) 175 continue; 176 sa = (struct sockaddr *)(void *)p; 177 len = SA_RLEN(sa); 178 if (i == RTAX_IFA) { 179 alen = len; 180 break; 181 } 182 p += len; 183 } 184 for (p = p0, i = 0; i < RTAX_MAX; i++) { 185 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 186 == 0) 187 continue; 188 sa = (struct sockaddr *)(void *)p; 189 len = SA_RLEN(sa); 190 if (i == RTAX_NETMASK && SA_LEN(sa) == 0) 191 dcnt += alen; 192 else 193 dcnt += len; 194 p += len; 195 } 196 break; 197 } 198 } 199 200 if (icnt + dcnt + ncnt == 1) { 201 *pif = NULL; 202 free(buf); 203 return (0); 204 } 205 data = malloc(sizeof(struct ifaddrs) * icnt + dcnt + ncnt); 206 if (data == NULL) { 207 free(buf); 208 return(-1); 209 } 210 211 ifa = (struct ifaddrs *)(void *)data; 212 data += sizeof(struct ifaddrs) * icnt; 213 names = data + dcnt; 214 215 memset(ifa, 0, sizeof(struct ifaddrs) * icnt); 216 ift = ifa; 217 218 idx = 0; 219 cif = NULL; 220 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 221 rtm = (struct rt_msghdr *)(void *)next; 222 if (rtm->rtm_version != RTM_VERSION) 223 continue; 224 switch (rtm->rtm_type) { 225 case RTM_IFINFO: 226 ifm = (struct if_msghdrl *)(void *)rtm; 227 if ((ifm->ifm_addrs & RTA_IFP) == 0) { 228 idx = 0; 229 break; 230 } 231 232 idx = ifm->ifm_index; 233 dl = (struct sockaddr_dl *)IF_MSGHDRL_RTA(ifm); 234 235 cif = ift; 236 ift->ifa_name = names; 237 ift->ifa_flags = (int)ifm->ifm_flags; 238 memcpy(names, dl->sdl_data, (size_t)dl->sdl_nlen); 239 names[dl->sdl_nlen] = 0; 240 names += dl->sdl_nlen + 1; 241 242 ift->ifa_addr = (struct sockaddr *)(void *)data; 243 memcpy(data, dl, (size_t)SA_LEN((struct sockaddr *) 244 (void *)dl)); 245 data += SA_RLEN((struct sockaddr *)(void *)dl); 246 247 if_data = IF_MSGHDRL_IFM_DATA(ifm); 248 /* ifm_data needs to be aligned */ 249 ift->ifa_data = data = (void *)ALIGN(data); 250 memcpy(data, if_data, if_data->ifi_datalen); 251 data += if_data->ifi_datalen; 252 253 ift = (ift->ifa_next = ift + 1); 254 break; 255 256 case RTM_NEWADDR: 257 ifam = (struct ifa_msghdrl *)(void *)rtm; 258 if (idx && ifam->ifam_index != idx) 259 abort(); /* this cannot happen */ 260 261 if (idx == 0 || (ifam->ifam_addrs & RTA_MASKS) == 0) 262 break; 263 ift->ifa_name = cif->ifa_name; 264 ift->ifa_flags = cif->ifa_flags; 265 ift->ifa_data = NULL; 266 267 p = (char *)IFA_MSGHDRL_RTA(ifam); 268 /* Scan to look for length of address */ 269 alen = 0; 270 for (p0 = p, i = 0; i < RTAX_MAX; i++) { 271 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 272 == 0) 273 continue; 274 sa = (struct sockaddr *)(void *)p; 275 len = SA_RLEN(sa); 276 if (i == RTAX_IFA) { 277 alen = len; 278 break; 279 } 280 p += len; 281 } 282 for (p = p0, i = 0; i < RTAX_MAX; i++) { 283 if ((RTA_MASKS & ifam->ifam_addrs & (1 << i)) 284 == 0) 285 continue; 286 sa = (struct sockaddr *)(void *)p; 287 len = SA_RLEN(sa); 288 switch (i) { 289 case RTAX_IFA: 290 ift->ifa_addr = 291 (struct sockaddr *)(void *)data; 292 memcpy(data, p, len); 293 data += len; 294 break; 295 296 case RTAX_NETMASK: 297 ift->ifa_netmask = 298 (struct sockaddr *)(void *)data; 299 if (SA_LEN(sa) == 0) { 300 memset(data, 0, alen); 301 data += alen; 302 break; 303 } 304 memcpy(data, p, len); 305 data += len; 306 break; 307 308 case RTAX_BRD: 309 ift->ifa_broadaddr = 310 (struct sockaddr *)(void *)data; 311 memcpy(data, p, len); 312 data += len; 313 break; 314 } 315 p += len; 316 } 317 318 if_data = IFA_MSGHDRL_IFAM_DATA(ifam); 319 /* ifam_data needs to be aligned */ 320 ift->ifa_data = data = (void *)ALIGN(data); 321 memcpy(data, if_data, if_data->ifi_datalen); 322 data += if_data->ifi_datalen; 323 324 ift = (ift->ifa_next = ift + 1); 325 break; 326 } 327 } 328 329 free(buf); 330 331 if (--ift >= ifa) { 332 ift->ifa_next = NULL; 333 *pif = ifa; 334 } else { 335 *pif = NULL; 336 free(ifa); 337 } 338 return (0); 339 } 340 341 void 342 freeifaddrs(struct ifaddrs *ifp) 343 { 344 345 free(ifp); 346 } 347