1 /* 2 * Copyright (c) 1988, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * @(#) Copyright (c) 1988, 1993 The Regents of the University of California. All rights reserved. 30 * @(#)hostname.c 8.1 (Berkeley) 5/31/93 31 * $FreeBSD: src/bin/hostname/hostname.c,v 1.10.2.1 2001/08/01 02:40:23 obrien Exp $ 32 */ 33 34 #include <sys/param.h> 35 #include <sys/ioctl.h> 36 #include <sys/socket.h> 37 #include <sys/sysctl.h> 38 #include <sys/module.h> 39 #include <sys/linker.h> 40 41 #include <net/ethernet.h> 42 #include <net/if.h> 43 #include <net/if_var.h> 44 #include <net/if_dl.h> 45 #include <net/if_types.h> 46 #include <net/route.h> 47 #include <netinet/in.h> 48 49 #include <err.h> 50 #include <stdio.h> 51 #include <stdlib.h> 52 #include <string.h> 53 #include <unistd.h> 54 55 #include <netdb.h> 56 #include <sys/types.h> 57 #include <arpa/inet.h> 58 59 #include <errno.h> 60 61 #define HST_IF (1 << 0) 62 #define HST_IF_V6 (1 << 1) 63 #define HST_IF_V4 (1 << 2) 64 65 /* 66 * Expand the compacted form of addresses as returned via the 67 * configuration read via sysctl(). 68 * Lifted from getifaddrs(3) 69 */ 70 71 static void rt_xaddrs(caddr_t, caddr_t, struct rt_addrinfo *); 72 static void usage (void); 73 74 #ifndef RT_ROUNDUP 75 #define RT_ROUNDUP(a) \ 76 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) 77 #endif 78 #ifndef RT_ADVANCE 79 #define RT_ADVANCE(x, n) (x += RT_ROUNDUP((n)->sa_len)) 80 #endif 81 82 static 83 void 84 rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo) 85 { 86 struct sockaddr *sa; 87 int i; 88 89 memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info)); 90 for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) { 91 if ((rtinfo->rti_addrs & (1 << i)) == 0) 92 continue; 93 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp; 94 RT_ADVANCE(cp, sa); 95 } 96 } 97 98 int 99 main(int argc, char **argv) 100 { 101 int ch, sflag, rflag, ret, flag6, iflag; 102 int silen = 0; 103 char hostname[MAXHOSTNAMELEN]; 104 char *srflag, *siflag; 105 struct hostent *hst; 106 struct in_addr ia; 107 struct in6_addr ia6; 108 109 int mib[6]; 110 size_t needed; 111 char *buf, *next, *p; 112 int idx; 113 struct sockaddr_dl *sdl; 114 struct rt_msghdr *rtm; 115 struct if_msghdr *ifm; 116 struct ifa_msghdr *ifam; 117 struct rt_addrinfo info; 118 struct sockaddr_in *sai; 119 struct sockaddr_in6 *sai6; 120 121 srflag = NULL; 122 siflag = NULL; 123 iflag = sflag = rflag = 0; 124 flag6 = 0; 125 hst = NULL; 126 127 while ((ch = getopt(argc, argv, "46i:r:s")) != -1) { 128 switch (ch) { 129 case '4': 130 iflag |= HST_IF_V4; 131 break; 132 case '6': 133 iflag |= HST_IF_V6; 134 break; 135 case 'i': 136 siflag = optarg; 137 silen = strlen(siflag); 138 iflag |= HST_IF; 139 break; 140 case 'r': 141 srflag = optarg; 142 rflag = 1; 143 break; 144 case 's': 145 sflag = 1; 146 break; 147 default: 148 usage(); 149 } 150 } 151 argc -= optind; 152 argv += optind; 153 154 if (argc > 1) 155 usage(); 156 157 if (iflag && *argv) 158 usage(); 159 160 if (rflag && *argv) 161 usage(); 162 163 if (rflag && (iflag & HST_IF)) 164 usage(); 165 166 if ((iflag & HST_IF_V6) && (iflag & HST_IF_V4)) 167 usage(); 168 169 if (!(iflag & HST_IF) && ((iflag & HST_IF_V6)||iflag & HST_IF_V4)) 170 usage(); 171 172 if (iflag & HST_IF) { 173 mib[0] = CTL_NET; 174 mib[1] = PF_ROUTE; 175 mib[2] = 0; 176 mib[3] = 0; 177 mib[4] = NET_RT_IFLIST; 178 mib[5] = 0; 179 180 idx = 0; 181 needed = 1; 182 183 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 184 err(1, "sysctl: iflist-sysctl-estimate"); 185 if ((buf = malloc(needed)) == NULL) 186 err(1, "malloc failed"); 187 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) 188 err(1, "sysctl: retrieval of interface table"); 189 190 for (next = buf; next < buf + needed; next += rtm->rtm_msglen) { 191 rtm = (struct rt_msghdr *)(void *)next; 192 if (rtm->rtm_version != RTM_VERSION) 193 continue; 194 switch (rtm->rtm_type) { 195 case RTM_IFINFO: 196 ifm = (struct if_msghdr *)(void *)rtm; 197 198 if ((ifm->ifm_addrs & RTA_IFP) == 0) 199 break; 200 sdl = (struct sockaddr_dl *)(ifm + 1); 201 if (silen != sdl->sdl_nlen) 202 break; 203 if (!strncmp(siflag, sdl->sdl_data, silen)) { 204 idx = ifm->ifm_index; 205 } 206 break; 207 case RTM_NEWADDR: 208 ifam = (struct ifa_msghdr *)(void *)rtm; 209 210 if (ifam->ifam_index == idx) { 211 info.rti_addrs = ifam->ifam_addrs; 212 rt_xaddrs((char *)(ifam + 1), 213 ifam->ifam_msglen + (char *)ifam, &info); 214 sai = (struct sockaddr_in *)info.rti_info[RTAX_IFA]; 215 216 if (iflag & HST_IF_V6) { 217 if (sai->sin_family == AF_INET6) { 218 sai6 = (struct sockaddr_in6 *)info.rti_info[RTAX_IFA]; 219 hst = gethostbyaddr(&sai6->sin6_addr, 220 sizeof(sai6->sin6_addr),AF_INET6); 221 222 if (h_errno == NETDB_SUCCESS) { 223 next = buf + needed; 224 continue; 225 } 226 } 227 } else { 228 if ((sai->sin_family == AF_INET)) { 229 230 hst = gethostbyaddr(&sai->sin_addr, 231 sizeof(sai->sin_addr),AF_INET); 232 233 if (h_errno == NETDB_SUCCESS) { 234 next = buf + needed; 235 continue; 236 } 237 } 238 } 239 } 240 break; 241 } /* switch */ 242 } /* loop */ 243 244 free(buf); 245 246 if (idx == 0) 247 errx(1,"interface not found"); 248 if (hst == NULL) 249 errx(1, "ip not found on interface"); 250 251 if (h_errno == NETDB_SUCCESS) { 252 if (sethostname(hst->h_name, (int)strlen(hst->h_name))) 253 err(1, "sethostname"); 254 } else if (h_errno == HOST_NOT_FOUND) { 255 errx(1,"hostname not found"); 256 } else { 257 herror("gethostbyaddr"); 258 exit(1); 259 } 260 } else if (rflag) { 261 ret = inet_pton(AF_INET, srflag, &ia); 262 if (ret != 1) { 263 /* check IPV6 */ 264 ret = inet_pton(AF_INET6, srflag, &ia6); 265 266 if (ret != 1) { 267 errx(1, "invalid ip address"); 268 } 269 270 flag6 = 1; 271 } 272 273 if (flag6 == 1) 274 hst = gethostbyaddr(&ia6, sizeof(ia6), AF_INET6); 275 else 276 hst = gethostbyaddr(&ia, sizeof(ia), AF_INET); 277 if (!hst) { 278 if (h_errno == HOST_NOT_FOUND) 279 errx(1,"host not found\n"); 280 } 281 282 if (sethostname(hst->h_name, (int)strlen(hst->h_name))) 283 err(1, "sethostname"); 284 } else if (*argv) { 285 if (sethostname(*argv, (int)strlen(*argv))) 286 err(1, "sethostname"); 287 } else { 288 if (gethostname(hostname, (int)sizeof(hostname))) 289 err(1, "gethostname"); 290 if (sflag && (p = strchr(hostname, '.'))) 291 *p = '\0'; 292 printf("%s\n", hostname); 293 } 294 exit(0); 295 } 296 297 static void 298 usage(void) 299 { 300 fprintf(stderr, "usage: hostname [-s] [name-of-host |" 301 " -r ip-address | -i interface [-4 | -6]]\n"); 302 exit(1); 303 } 304 305