ifiter_getifaddrs.c revision 290001
1/* 2 * Copyright (C) 2004, 2005, 2007-2009 Internet Systems Consortium, Inc. ("ISC") 3 * Copyright (C) 2003 Internet Software Consortium. 4 * 5 * Permission to use, copy, modify, and/or distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 15 * PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18/* $Id: ifiter_getifaddrs.c,v 1.13 2009/09/24 23:48:13 tbox Exp $ */ 19 20/*! \file 21 * \brief 22 * Obtain the list of network interfaces using the getifaddrs(3) library. 23 */ 24 25#include <ifaddrs.h> 26 27/*% Iterator Magic */ 28#define IFITER_MAGIC ISC_MAGIC('I', 'F', 'I', 'G') 29/*% Valid Iterator */ 30#define VALID_IFITER(t) ISC_MAGIC_VALID(t, IFITER_MAGIC) 31 32#ifdef __linux 33static isc_boolean_t seenv6 = ISC_FALSE; 34#endif 35 36/*% Iterator structure */ 37struct isc_interfaceiter { 38 unsigned int magic; /*%< Magic number. */ 39 isc_mem_t *mctx; 40 void *buf; /*%< (unused) */ 41 unsigned int bufsize; /*%< (always 0) */ 42 struct ifaddrs *ifaddrs; /*%< List of ifaddrs */ 43 struct ifaddrs *pos; /*%< Ptr to current ifaddr */ 44 isc_interface_t current; /*%< Current interface data. */ 45 isc_result_t result; /*%< Last result code. */ 46#ifdef __linux 47 FILE * proc; 48 char entry[ISC_IF_INET6_SZ]; 49 isc_result_t valid; 50#endif 51}; 52 53isc_result_t 54isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) { 55 isc_interfaceiter_t *iter; 56 isc_result_t result; 57 char strbuf[ISC_STRERRORSIZE]; 58 int trys, ret; 59 60 REQUIRE(mctx != NULL); 61 REQUIRE(iterp != NULL); 62 REQUIRE(*iterp == NULL); 63 64 iter = isc_mem_get(mctx, sizeof(*iter)); 65 if (iter == NULL) 66 return (ISC_R_NOMEMORY); 67 68 iter->mctx = mctx; 69 iter->buf = NULL; 70 iter->bufsize = 0; 71 iter->ifaddrs = NULL; 72#ifdef __linux 73 /* 74 * Only open "/proc/net/if_inet6" if we have never seen a IPv6 75 * address returned by getifaddrs(). 76 */ 77 if (!seenv6) { 78 iter->proc = fopen("/proc/net/if_inet6", "r"); 79 if (iter->proc == NULL) { 80 isc__strerror(errno, strbuf, sizeof(strbuf)); 81 isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL, 82 ISC_LOGMODULE_SOCKET, ISC_LOG_WARNING, 83 "failed to open /proc/net/if_inet6"); 84 } 85 } else 86 iter->proc = NULL; 87 iter->valid = ISC_R_FAILURE; 88#endif 89 90 /* If interrupted, try again */ 91 for (trys = 0; trys < 3; trys++) { 92 if ((ret = getifaddrs(&iter->ifaddrs)) >= 0) 93 break; 94 if (errno != EINTR) 95 break; 96 } 97 if (ret < 0) { 98 isc__strerror(errno, strbuf, sizeof(strbuf)); 99 UNEXPECTED_ERROR(__FILE__, __LINE__, 100 "getting interface addresses: %s: %s", 101 isc_msgcat_get(isc_msgcat, 102 ISC_MSGSET_IFITERGETIFADDRS, 103 ISC_MSG_GETIFADDRS, 104 "getifaddrs"), 105 strbuf); 106 result = ISC_R_UNEXPECTED; 107 goto failure; 108 } 109 110 /* 111 * A newly created iterator has an undefined position 112 * until isc_interfaceiter_first() is called. 113 */ 114 iter->pos = NULL; 115 iter->result = ISC_R_FAILURE; 116 117 iter->magic = IFITER_MAGIC; 118 *iterp = iter; 119 return (ISC_R_SUCCESS); 120 121 failure: 122#ifdef __linux 123 if (iter->proc != NULL) 124 fclose(iter->proc); 125#endif 126 if (iter->ifaddrs != NULL) /* just in case */ 127 freeifaddrs(iter->ifaddrs); 128 isc_mem_put(mctx, iter, sizeof(*iter)); 129 return (result); 130} 131 132/* 133 * Get information about the current interface to iter->current. 134 * If successful, return ISC_R_SUCCESS. 135 * If the interface has an unsupported address family, 136 * return ISC_R_IGNORE. 137 */ 138 139static isc_result_t 140internal_current(isc_interfaceiter_t *iter) { 141 struct ifaddrs *ifa; 142 int family; 143 unsigned int namelen; 144 145 REQUIRE(VALID_IFITER(iter)); 146 147 ifa = iter->pos; 148 149#ifdef __linux 150 /* 151 * [Bug 2792] 152 * burnicki: iter->pos is usually never NULL here (anymore?), 153 * so linux_if_inet6_current(iter) is never called here. 154 * However, that routine would check (under Linux), if the 155 * interface is in a tentative state, e.g. if there's no link 156 * yet but an IPv6 address has already be assigned. 157 */ 158 if (iter->pos == NULL) 159 return (linux_if_inet6_current(iter)); 160#endif 161 162 INSIST(ifa != NULL); 163 INSIST(ifa->ifa_name != NULL); 164 165 166#ifdef IFF_RUNNING 167 /* 168 * [Bug 2792] 169 * burnicki: if the interface is not running then 170 * it may be in a tentative state. See above. 171 */ 172 if ((ifa->ifa_flags & IFF_RUNNING) == 0) 173 return (ISC_R_IGNORE); 174#endif 175 176 if (ifa->ifa_addr == NULL) 177 return (ISC_R_IGNORE); 178 179 family = ifa->ifa_addr->sa_family; 180 if (family != AF_INET && family != AF_INET6) 181 return (ISC_R_IGNORE); 182 183#ifdef __linux 184 if (family == AF_INET6) 185 seenv6 = ISC_TRUE; 186#endif 187 188 memset(&iter->current, 0, sizeof(iter->current)); 189 190 namelen = strlen(ifa->ifa_name); 191 if (namelen > sizeof(iter->current.name) - 1) 192 namelen = sizeof(iter->current.name) - 1; 193 194 memset(iter->current.name, 0, sizeof(iter->current.name)); 195 memcpy(iter->current.name, ifa->ifa_name, namelen); 196 197 iter->current.flags = 0; 198 199 if ((ifa->ifa_flags & IFF_UP) != 0) 200 iter->current.flags |= INTERFACE_F_UP; 201 202 if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0) 203 iter->current.flags |= INTERFACE_F_POINTTOPOINT; 204 205 if ((ifa->ifa_flags & IFF_LOOPBACK) != 0) 206 iter->current.flags |= INTERFACE_F_LOOPBACK; 207 208 if ((ifa->ifa_flags & IFF_BROADCAST) != 0) 209 iter->current.flags |= INTERFACE_F_BROADCAST; 210 211#ifdef IFF_MULTICAST 212 if ((ifa->ifa_flags & IFF_MULTICAST) != 0) 213 iter->current.flags |= INTERFACE_F_MULTICAST; 214#endif 215 216 iter->current.af = family; 217 218 get_addr(family, &iter->current.address, ifa->ifa_addr, ifa->ifa_name); 219 220 if (ifa->ifa_netmask != NULL) 221 get_addr(family, &iter->current.netmask, ifa->ifa_netmask, 222 ifa->ifa_name); 223 224 if (ifa->ifa_dstaddr != NULL && 225 (iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0) 226 get_addr(family, &iter->current.dstaddress, ifa->ifa_dstaddr, 227 ifa->ifa_name); 228 229 if (ifa->ifa_broadaddr != NULL && 230 (iter->current.flags & INTERFACE_F_BROADCAST) != 0) 231 get_addr(family, &iter->current.broadcast, ifa->ifa_broadaddr, 232 ifa->ifa_name); 233 234#ifdef ISC_PLATFORM_HAVEIFNAMETOINDEX 235 iter->current.ifindex = if_nametoindex(iter->current.name); 236#endif 237 return (ISC_R_SUCCESS); 238} 239 240/* 241 * Step the iterator to the next interface. Unlike 242 * isc_interfaceiter_next(), this may leave the iterator 243 * positioned on an interface that will ultimately 244 * be ignored. Return ISC_R_NOMORE if there are no more 245 * interfaces, otherwise ISC_R_SUCCESS. 246 */ 247static isc_result_t 248internal_next(isc_interfaceiter_t *iter) { 249 250 if (iter->pos != NULL) 251 iter->pos = iter->pos->ifa_next; 252 if (iter->pos == NULL) { 253#ifdef __linux 254 if (!seenv6) 255 return (linux_if_inet6_next(iter)); 256#endif 257 return (ISC_R_NOMORE); 258 } 259 260 return (ISC_R_SUCCESS); 261} 262 263static void 264internal_destroy(isc_interfaceiter_t *iter) { 265 266#ifdef __linux 267 if (iter->proc != NULL) 268 fclose(iter->proc); 269 iter->proc = NULL; 270#endif 271 if (iter->ifaddrs) 272 freeifaddrs(iter->ifaddrs); 273 iter->ifaddrs = NULL; 274} 275 276static 277void internal_first(isc_interfaceiter_t *iter) { 278 279#ifdef __linux 280 linux_if_inet6_first(iter); 281#endif 282 iter->pos = iter->ifaddrs; 283} 284