1/* 2 * Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") 3 * Copyright (C) 1999-2003 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_sysctl.c,v 1.25 2007/06/19 23:47:18 tbox Exp $ */ 19 20/*! \file 21 * \brief 22 * Obtain the list of network interfaces using sysctl. 23 * See TCP/IP Illustrated Volume 2, sections 19.8, 19.14, 24 * and 19.16. 25 */ 26 27#include <sys/param.h> 28#include <sys/sysctl.h> 29 30#include <net/route.h> 31#include <net/if_dl.h> 32 33/* XXX what about Alpha? */ 34#ifdef sgi 35#define ROUNDUP(a) ((a) > 0 ? \ 36 (1 + (((a) - 1) | (sizeof(__uint64_t) - 1))) : \ 37 sizeof(__uint64_t)) 38#else 39#define ROUNDUP(a) ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) \ 40 : sizeof(long)) 41#endif 42 43#define IFITER_MAGIC ISC_MAGIC('I', 'F', 'I', 'S') 44#define VALID_IFITER(t) ISC_MAGIC_VALID(t, IFITER_MAGIC) 45 46struct isc_interfaceiter { 47 unsigned int magic; /* Magic number. */ 48 isc_mem_t *mctx; 49 void *buf; /* Buffer for sysctl data. */ 50 unsigned int bufsize; /* Bytes allocated. */ 51 unsigned int bufused; /* Bytes used. */ 52 unsigned int pos; /* Current offset in 53 sysctl data. */ 54 isc_interface_t current; /* Current interface data. */ 55 isc_result_t result; /* Last result code. */ 56}; 57 58static int mib[6] = { 59 CTL_NET, 60 PF_ROUTE, 61 0, 62 0, /* Any address family. */ 63 NET_RT_IFLIST, 64 0 /* Flags. */ 65}; 66 67isc_result_t 68isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) { 69 isc_interfaceiter_t *iter; 70 isc_result_t result; 71 size_t bufsize; 72 size_t bufused; 73 char strbuf[ISC_STRERRORSIZE]; 74 75 REQUIRE(mctx != NULL); 76 REQUIRE(iterp != NULL); 77 REQUIRE(*iterp == NULL); 78 79 iter = isc_mem_get(mctx, sizeof(*iter)); 80 if (iter == NULL) 81 return (ISC_R_NOMEMORY); 82 83 iter->mctx = mctx; 84 iter->buf = 0; 85 86 /* 87 * Determine the amount of memory needed. 88 */ 89 bufsize = 0; 90 if (sysctl(mib, 6, NULL, &bufsize, NULL, (size_t) 0) < 0) { 91 isc__strerror(errno, strbuf, sizeof(strbuf)); 92 UNEXPECTED_ERROR(__FILE__, __LINE__, 93 isc_msgcat_get(isc_msgcat, 94 ISC_MSGSET_IFITERSYSCTL, 95 ISC_MSG_GETIFLISTSIZE, 96 "getting interface " 97 "list size: sysctl: %s"), 98 strbuf); 99 result = ISC_R_UNEXPECTED; 100 goto failure; 101 } 102 iter->bufsize = bufsize; 103 104 iter->buf = isc_mem_get(iter->mctx, iter->bufsize); 105 if (iter->buf == NULL) { 106 result = ISC_R_NOMEMORY; 107 goto failure; 108 } 109 110 bufused = bufsize; 111 if (sysctl(mib, 6, iter->buf, &bufused, NULL, (size_t) 0) < 0) { 112 isc__strerror(errno, strbuf, sizeof(strbuf)); 113 UNEXPECTED_ERROR(__FILE__, __LINE__, 114 isc_msgcat_get(isc_msgcat, 115 ISC_MSGSET_IFITERSYSCTL, 116 ISC_MSG_GETIFLIST, 117 "getting interface list: " 118 "sysctl: %s"), 119 strbuf); 120 result = ISC_R_UNEXPECTED; 121 goto failure; 122 } 123 iter->bufused = bufused; 124 INSIST(iter->bufused <= iter->bufsize); 125 126 /* 127 * A newly created iterator has an undefined position 128 * until isc_interfaceiter_first() is called. 129 */ 130 iter->pos = (unsigned int) -1; 131 iter->result = ISC_R_FAILURE; 132 133 iter->magic = IFITER_MAGIC; 134 *iterp = iter; 135 return (ISC_R_SUCCESS); 136 137 failure: 138 if (iter->buf != NULL) 139 isc_mem_put(mctx, iter->buf, iter->bufsize); 140 isc_mem_put(mctx, iter, sizeof(*iter)); 141 return (result); 142} 143 144/* 145 * Get information about the current interface to iter->current. 146 * If successful, return ISC_R_SUCCESS. 147 * If the interface has an unsupported address family, 148 * return ISC_R_IGNORE. In case of other failure, 149 * return ISC_R_UNEXPECTED. 150 */ 151 152static isc_result_t 153internal_current(isc_interfaceiter_t *iter) { 154 struct ifa_msghdr *ifam, *ifam_end; 155 156 REQUIRE(VALID_IFITER(iter)); 157 REQUIRE (iter->pos < (unsigned int) iter->bufused); 158 159 ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos); 160 ifam_end = (struct ifa_msghdr *) ((char *) iter->buf + iter->bufused); 161 162 if (ifam->ifam_type == RTM_IFINFO) { 163 struct if_msghdr *ifm = (struct if_msghdr *) ifam; 164 struct sockaddr_dl *sdl = (struct sockaddr_dl *) (ifm + 1); 165 unsigned int namelen; 166 167 memset(&iter->current, 0, sizeof(iter->current)); 168 169 namelen = sdl->sdl_nlen; 170 if (namelen > sizeof(iter->current.name) - 1) 171 namelen = sizeof(iter->current.name) - 1; 172 173 memset(iter->current.name, 0, sizeof(iter->current.name)); 174 memcpy(iter->current.name, sdl->sdl_data, namelen); 175 176 iter->current.flags = 0; 177 178 if ((ifam->ifam_flags & IFF_UP) != 0) 179 iter->current.flags |= INTERFACE_F_UP; 180 181 if ((ifam->ifam_flags & IFF_POINTOPOINT) != 0) 182 iter->current.flags |= INTERFACE_F_POINTTOPOINT; 183 184 if ((ifam->ifam_flags & IFF_LOOPBACK) != 0) 185 iter->current.flags |= INTERFACE_F_LOOPBACK; 186 187 /* 188 * This is not an interface address. 189 * Force another iteration. 190 */ 191 return (ISC_R_IGNORE); 192 } else if (ifam->ifam_type == RTM_NEWADDR) { 193 int i; 194 int family; 195 struct sockaddr *mask_sa = NULL; 196 struct sockaddr *addr_sa = NULL; 197 struct sockaddr *dst_sa = NULL; 198 199 struct sockaddr *sa = (struct sockaddr *)(ifam + 1); 200 family = sa->sa_family; 201 202 for (i = 0; i < RTAX_MAX; i++) 203 { 204 if ((ifam->ifam_addrs & (1 << i)) == 0) 205 continue; 206 207 INSIST(sa < (struct sockaddr *) ifam_end); 208 209 switch (i) { 210 case RTAX_NETMASK: /* Netmask */ 211 mask_sa = sa; 212 break; 213 case RTAX_IFA: /* Interface address */ 214 addr_sa = sa; 215 break; 216 case RTAX_BRD: /* Broadcast or destination address */ 217 dst_sa = sa; 218 break; 219 } 220#ifdef ISC_PLATFORM_HAVESALEN 221 sa = (struct sockaddr *)((char*)(sa) 222 + ROUNDUP(sa->sa_len)); 223#else 224#ifdef sgi 225 /* 226 * Do as the contributed SGI code does. 227 */ 228 sa = (struct sockaddr *)((char*)(sa) 229 + ROUNDUP(_FAKE_SA_LEN_DST(sa))); 230#else 231 /* XXX untested. */ 232 sa = (struct sockaddr *)((char*)(sa) 233 + ROUNDUP(sizeof(struct sockaddr))); 234#endif 235#endif 236 } 237 238 if (addr_sa == NULL) 239 return (ISC_R_IGNORE); 240 241 family = addr_sa->sa_family; 242 if (family != AF_INET && family != AF_INET6) 243 return (ISC_R_IGNORE); 244 245 iter->current.af = family; 246 247 get_addr(family, &iter->current.address, addr_sa, 248 iter->current.name); 249 250 if (mask_sa != NULL) 251 get_addr(family, &iter->current.netmask, mask_sa, 252 iter->current.name); 253 254 if (dst_sa != NULL && 255 (iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0) 256 get_addr(family, &iter->current.dstaddress, dst_sa, 257 iter->current.name); 258 259 return (ISC_R_SUCCESS); 260 } else { 261 printf(isc_msgcat_get(isc_msgcat, ISC_MSGSET_IFITERSYSCTL, 262 ISC_MSG_UNEXPECTEDTYPE, 263 "warning: unexpected interface list " 264 "message type\n")); 265 return (ISC_R_IGNORE); 266 } 267} 268 269/* 270 * Step the iterator to the next interface. Unlike 271 * isc_interfaceiter_next(), this may leave the iterator 272 * positioned on an interface that will ultimately 273 * be ignored. Return ISC_R_NOMORE if there are no more 274 * interfaces, otherwise ISC_R_SUCCESS. 275 */ 276static isc_result_t 277internal_next(isc_interfaceiter_t *iter) { 278 struct ifa_msghdr *ifam; 279 REQUIRE (iter->pos < (unsigned int) iter->bufused); 280 281 ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos); 282 283 iter->pos += ifam->ifam_msglen; 284 285 if (iter->pos >= iter->bufused) 286 return (ISC_R_NOMORE); 287 288 return (ISC_R_SUCCESS); 289} 290 291static void 292internal_destroy(isc_interfaceiter_t *iter) { 293 UNUSED(iter); /* Unused. */ 294 /* 295 * Do nothing. 296 */ 297} 298 299static 300void internal_first(isc_interfaceiter_t *iter) { 301 iter->pos = 0; 302} 303