1 /* $NetBSD: ifiter_sysctl.c,v 1.2 2024/08/18 20:47:16 christos Exp $ */ 2 3 /* 4 * Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") 5 * Copyright (C) 1999-2003 Internet Software Consortium. 6 * 7 * Permission to use, copy, modify, and/or distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 12 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 13 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 14 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 15 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 16 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 17 * PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 /* Id: ifiter_sysctl.c,v 1.25 2007/06/19 23:47:18 tbox Exp */ 21 22 /*! \file 23 * \brief 24 * Obtain the list of network interfaces using sysctl. 25 * See TCP/IP Illustrated Volume 2, sections 19.8, 19.14, 26 * and 19.16. 27 */ 28 29 #include <sys/param.h> 30 #include <sys/sysctl.h> 31 32 #include <net/route.h> 33 #include <net/if_dl.h> 34 35 /* XXX what about Alpha? */ 36 #ifdef sgi 37 #define ROUNDUP(a) ((a) > 0 ? \ 38 (1 + (((a) - 1) | (sizeof(__uint64_t) - 1))) : \ 39 sizeof(__uint64_t)) 40 #else 41 #define ROUNDUP(a) ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) \ 42 : sizeof(long)) 43 #endif 44 45 #define IFITER_MAGIC ISC_MAGIC('I', 'F', 'I', 'S') 46 #define VALID_IFITER(t) ISC_MAGIC_VALID(t, IFITER_MAGIC) 47 48 struct isc_interfaceiter { 49 unsigned int magic; /* Magic number. */ 50 isc_mem_t *mctx; 51 void *buf; /* Buffer for sysctl data. */ 52 unsigned int bufsize; /* Bytes allocated. */ 53 unsigned int bufused; /* Bytes used. */ 54 unsigned int pos; /* Current offset in 55 sysctl data. */ 56 isc_interface_t current; /* Current interface data. */ 57 isc_result_t result; /* Last result code. */ 58 }; 59 60 static int mib[6] = { 61 CTL_NET, 62 PF_ROUTE, 63 0, 64 0, /* Any address family. */ 65 NET_RT_IFLIST, 66 0 /* Flags. */ 67 }; 68 69 isc_result_t 70 isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) { 71 isc_interfaceiter_t *iter; 72 isc_result_t result; 73 size_t bufsize; 74 size_t bufused; 75 char strbuf[ISC_STRERRORSIZE]; 76 77 REQUIRE(mctx != NULL); 78 REQUIRE(iterp != NULL); 79 REQUIRE(*iterp == NULL); 80 81 iter = isc_mem_get(mctx, sizeof(*iter)); 82 if (iter == NULL) 83 return (ISC_R_NOMEMORY); 84 85 iter->mctx = mctx; 86 iter->buf = 0; 87 88 /* 89 * Determine the amount of memory needed. 90 */ 91 bufsize = 0; 92 if (sysctl(mib, 6, NULL, &bufsize, NULL, (size_t) 0) < 0) { 93 isc__strerror(errno, strbuf, sizeof(strbuf)); 94 UNEXPECTED_ERROR(__FILE__, __LINE__, 95 isc_msgcat_get(isc_msgcat, 96 ISC_MSGSET_IFITERSYSCTL, 97 ISC_MSG_GETIFLISTSIZE, 98 "getting interface " 99 "list size: sysctl: %s"), 100 strbuf); 101 result = ISC_R_UNEXPECTED; 102 goto failure; 103 } 104 iter->bufsize = bufsize; 105 106 iter->buf = isc_mem_get(iter->mctx, iter->bufsize); 107 if (iter->buf == NULL) { 108 result = ISC_R_NOMEMORY; 109 goto failure; 110 } 111 112 bufused = bufsize; 113 if (sysctl(mib, 6, iter->buf, &bufused, NULL, (size_t) 0) < 0) { 114 isc__strerror(errno, strbuf, sizeof(strbuf)); 115 UNEXPECTED_ERROR(__FILE__, __LINE__, 116 isc_msgcat_get(isc_msgcat, 117 ISC_MSGSET_IFITERSYSCTL, 118 ISC_MSG_GETIFLIST, 119 "getting interface list: " 120 "sysctl: %s"), 121 strbuf); 122 result = ISC_R_UNEXPECTED; 123 goto failure; 124 } 125 iter->bufused = bufused; 126 INSIST(iter->bufused <= iter->bufsize); 127 128 /* 129 * A newly created iterator has an undefined position 130 * until isc_interfaceiter_first() is called. 131 */ 132 iter->pos = (unsigned int) -1; 133 iter->result = ISC_R_FAILURE; 134 135 iter->magic = IFITER_MAGIC; 136 *iterp = iter; 137 return (ISC_R_SUCCESS); 138 139 failure: 140 if (iter->buf != NULL) 141 isc_mem_put(mctx, iter->buf, iter->bufsize); 142 isc_mem_put(mctx, iter, sizeof(*iter)); 143 return (result); 144 } 145 146 /* 147 * Get information about the current interface to iter->current. 148 * If successful, return ISC_R_SUCCESS. 149 * If the interface has an unsupported address family, 150 * return ISC_R_IGNORE. In case of other failure, 151 * return ISC_R_UNEXPECTED. 152 */ 153 154 static isc_result_t 155 internal_current(isc_interfaceiter_t *iter) { 156 struct ifa_msghdr *ifam, *ifam_end; 157 158 REQUIRE(VALID_IFITER(iter)); 159 REQUIRE (iter->pos < (unsigned int) iter->bufused); 160 161 ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos); 162 ifam_end = (struct ifa_msghdr *) ((char *) iter->buf + iter->bufused); 163 164 // Skip wrong RTM version headers 165 if (ifam->ifam_version != RTM_VERSION) 166 return (ISC_R_IGNORE); 167 168 if (ifam->ifam_type == RTM_IFINFO) { 169 struct if_msghdr *ifm = (struct if_msghdr *) ifam; 170 struct sockaddr_dl *sdl = (struct sockaddr_dl *) (ifm + 1); 171 unsigned int namelen; 172 173 memset(&iter->current, 0, sizeof(iter->current)); 174 175 iter->current.ifindex = sdl->sdl_index; 176 namelen = sdl->sdl_nlen; 177 if (namelen > sizeof(iter->current.name) - 1) 178 namelen = sizeof(iter->current.name) - 1; 179 180 memset(iter->current.name, 0, sizeof(iter->current.name)); 181 memcpy(iter->current.name, sdl->sdl_data, namelen); 182 183 iter->current.flags = 0; 184 185 if ((ifam->ifam_flags & IFF_UP) != 0) 186 iter->current.flags |= INTERFACE_F_UP; 187 188 if ((ifam->ifam_flags & IFF_POINTOPOINT) != 0) 189 iter->current.flags |= INTERFACE_F_POINTTOPOINT; 190 191 if ((ifam->ifam_flags & IFF_LOOPBACK) != 0) 192 iter->current.flags |= INTERFACE_F_LOOPBACK; 193 194 if ((ifam->ifam_flags & IFF_BROADCAST) != 0) 195 iter->current.flags |= INTERFACE_F_BROADCAST; 196 197 #ifdef IFF_MULTICAST 198 if ((ifam->ifam_flags & IFF_MULTICAST) != 0) 199 iter->current.flags |= INTERFACE_F_MULTICAST; 200 #endif 201 202 /* 203 * This is not an interface address. 204 * Force another iteration. 205 */ 206 return (ISC_R_IGNORE); 207 } else if (ifam->ifam_type == RTM_NEWADDR) { 208 int i; 209 int family; 210 struct sockaddr *mask_sa = NULL; 211 struct sockaddr *addr_sa = NULL; 212 struct sockaddr *dst_sa = NULL; 213 214 struct sockaddr *sa = (struct sockaddr *)(ifam + 1); 215 family = sa->sa_family; 216 217 for (i = 0; i < RTAX_MAX; i++) 218 { 219 if ((ifam->ifam_addrs & (1 << i)) == 0) 220 continue; 221 222 INSIST(sa < (struct sockaddr *) ifam_end); 223 224 switch (i) { 225 case RTAX_NETMASK: /* Netmask */ 226 mask_sa = sa; 227 break; 228 case RTAX_IFA: /* Interface address */ 229 addr_sa = sa; 230 break; 231 case RTAX_BRD: /* Broadcast or destination address */ 232 dst_sa = sa; 233 break; 234 } 235 #ifdef ISC_PLATFORM_HAVESALEN 236 sa = (struct sockaddr *)((char*)(sa) 237 + ROUNDUP(sa->sa_len)); 238 #else 239 #ifdef sgi 240 /* 241 * Do as the contributed SGI code does. 242 */ 243 sa = (struct sockaddr *)((char*)(sa) 244 + ROUNDUP(_FAKE_SA_LEN_DST(sa))); 245 #else 246 /* XXX untested. */ 247 sa = (struct sockaddr *)((char*)(sa) 248 + ROUNDUP(sizeof(struct sockaddr))); 249 #endif 250 #endif 251 } 252 253 if (addr_sa == NULL) 254 return (ISC_R_IGNORE); 255 256 family = addr_sa->sa_family; 257 if (family != AF_INET && family != AF_INET6) 258 return (ISC_R_IGNORE); 259 260 iter->current.af = family; 261 262 get_addr(family, &iter->current.address, addr_sa, 263 iter->current.name); 264 265 if (mask_sa != NULL) 266 get_addr(family, &iter->current.netmask, mask_sa, 267 iter->current.name); 268 269 if (dst_sa != NULL && 270 (iter->current.flags & INTERFACE_F_POINTTOPOINT) != 0) 271 get_addr(family, &iter->current.dstaddress, dst_sa, 272 iter->current.name); 273 274 if (dst_sa != NULL && 275 (iter->current.flags & INTERFACE_F_BROADCAST) != 0) 276 get_addr(family, &iter->current.broadcast, dst_sa, 277 iter->current.name); 278 279 return (ISC_R_SUCCESS); 280 } else { 281 printf("%s", isc_msgcat_get(isc_msgcat, 282 ISC_MSGSET_IFITERSYSCTL, 283 ISC_MSG_UNEXPECTEDTYPE, 284 "warning: unexpected interface " 285 "list message type\n")); 286 return (ISC_R_IGNORE); 287 } 288 } 289 290 /* 291 * Step the iterator to the next interface. Unlike 292 * isc_interfaceiter_next(), this may leave the iterator 293 * positioned on an interface that will ultimately 294 * be ignored. Return ISC_R_NOMORE if there are no more 295 * interfaces, otherwise ISC_R_SUCCESS. 296 */ 297 static isc_result_t 298 internal_next(isc_interfaceiter_t *iter) { 299 struct ifa_msghdr *ifam; 300 REQUIRE (iter->pos < (unsigned int) iter->bufused); 301 302 ifam = (struct ifa_msghdr *) ((char *) iter->buf + iter->pos); 303 304 iter->pos += ifam->ifam_msglen; 305 306 if (iter->pos >= iter->bufused) 307 return (ISC_R_NOMORE); 308 309 return (ISC_R_SUCCESS); 310 } 311 312 static void 313 internal_destroy(isc_interfaceiter_t *iter) { 314 UNUSED(iter); /* Unused. */ 315 /* 316 * Do nothing. 317 */ 318 } 319 320 static 321 void internal_first(isc_interfaceiter_t *iter) { 322 iter->pos = 0; 323 } 324