1 /* $NetBSD: hostname.c,v 1.20 2013/07/19 15:53:00 christos Exp $ */ 2 3 /* 4 * Copyright (c) 1988, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 #ifndef lint 34 __COPYRIGHT("@(#) Copyright (c) 1988, 1993\ 35 The Regents of the University of California. All rights reserved."); 36 #endif /* not lint */ 37 38 #ifndef lint 39 #if 0 40 static char sccsid[] = "@(#)hostname.c 8.2 (Berkeley) 4/28/95"; 41 #else 42 __RCSID("$NetBSD: hostname.c,v 1.20 2013/07/19 15:53:00 christos Exp $"); 43 #endif 44 #endif /* not lint */ 45 46 #include <sys/param.h> 47 #include <sys/socket.h> 48 49 #include <net/if.h> 50 #include <netinet/in.h> 51 52 #include <err.h> 53 #include <ifaddrs.h> 54 #include <netdb.h> 55 #include <stdio.h> 56 #include <stdlib.h> 57 #include <string.h> 58 #include <unistd.h> 59 60 __dead static void usage(void); 61 62 int 63 main(int argc, char *argv[]) 64 { 65 int ch, Aflag, aflag, dflag, Iflag, iflag, fflag, sflag, i; 66 char *p, hostname[MAXHOSTNAMELEN + 1]; 67 struct addrinfo hints, *ainfos, *ai; 68 struct hostent *hent; 69 struct ifaddrs *ifa, *ifp; 70 struct sockaddr_in6 *sin6; 71 char buf[MAX(MAXHOSTNAMELEN + 1, INET6_ADDRSTRLEN)]; 72 73 setprogname(argv[0]); 74 Aflag = aflag = dflag = Iflag = iflag = fflag = sflag = 0; 75 while ((ch = getopt(argc, argv, "AadIifs")) != -1) 76 switch (ch) { 77 case 'A': 78 Aflag = 1; 79 break; 80 case 'a': 81 aflag = 1; 82 break; 83 case 'd': 84 dflag = 1; 85 break; 86 case 'I': 87 Iflag = 1; 88 break; 89 case 'i': 90 iflag = 1; 91 break; 92 case 'f': 93 fflag = 1; 94 break; 95 case 's': 96 sflag = 1; 97 break; 98 case '?': 99 default: 100 usage(); 101 } 102 argc -= optind; 103 argv += optind; 104 105 if (argc > 1) 106 usage(); 107 108 if (*argv) { 109 if (sethostname(*argv, strlen(*argv))) 110 err(1, "sethostname"); 111 } else if (Aflag || Iflag) { 112 if (getifaddrs(&ifa) == -1) 113 err(1, "getifaddrs"); 114 for (ifp = ifa; ifp; ifp = ifp->ifa_next) { 115 if (ifp->ifa_addr == NULL || 116 #if !defined(__minix) 117 ifp->ifa_flags & IFF_LOOPBACK || 118 #endif 119 !(ifp->ifa_flags & IFF_UP)) 120 continue; 121 122 switch(ifp->ifa_addr->sa_family) { 123 case AF_INET: 124 break; 125 case AF_INET6: 126 /* Skip link local addresses */ 127 sin6 = (struct sockaddr_in6 *)ifp->ifa_addr; 128 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr) || 129 IN6_IS_ADDR_MC_LINKLOCAL(&sin6->sin6_addr)) 130 continue; 131 break; 132 default: 133 /* We only translate IPv4 or IPv6 addresses */ 134 continue; 135 } 136 i = getnameinfo(ifp->ifa_addr, ifp->ifa_addr->sa_len, 137 buf, sizeof(buf), NULL, 0, 138 Iflag ? NI_NUMERICHOST: NI_NAMEREQD); 139 if (i) { 140 if (Iflag && i != EAI_NONAME) 141 errx(1, "getnameinfo: %s", 142 gai_strerror(i)); 143 } else 144 printf("%s\n", buf); 145 } 146 freeifaddrs(ifa); 147 } else { 148 if (gethostname(hostname, sizeof(hostname))) 149 err(1, "gethostname"); 150 hostname[sizeof(hostname) - 1] = '\0'; 151 if (aflag) { 152 if ((hent = gethostbyname(hostname)) == NULL) 153 errx(1, "gethostbyname: %s", 154 hstrerror(h_errno)); 155 for (i = 0; hent->h_aliases[i]; i++) 156 printf("%s\n", hent->h_aliases[i]); 157 } else if (dflag || iflag || fflag) { 158 memset(&hints, 0, sizeof(hints)); 159 hints.ai_family = AF_UNSPEC; 160 hints.ai_socktype = SOCK_DGRAM; 161 hints.ai_flags = AI_CANONNAME; 162 i = getaddrinfo(hostname, NULL, &hints, &ainfos); 163 if (i) 164 errx(1, "getaddrinfo: %s", gai_strerror(i)); 165 if (ainfos) { 166 if (dflag) { 167 if ((p = strchr(ainfos->ai_canonname, 168 '.'))) 169 printf("%s\n", p + 1); 170 } else if (iflag) { 171 for (ai = ainfos; ai; ai = ai->ai_next) 172 { 173 i = getnameinfo(ai->ai_addr, 174 ai->ai_addrlen, 175 buf, sizeof(buf), NULL, 0, 176 NI_NUMERICHOST); 177 if (i) 178 errx(1, 179 "getnameinfo: %s", 180 gai_strerror(i)); 181 printf("%s\n", buf); 182 } 183 } else { 184 if (sflag && 185 (p = strchr(ainfos->ai_canonname, 186 '.'))) 187 *p = '\0'; 188 printf("%s\n", ainfos->ai_canonname); 189 } 190 freeaddrinfo(ainfos); 191 } 192 } else { 193 if (sflag && (p = strchr(hostname, '.'))) 194 *p = '\0'; 195 printf("%s\n", hostname); 196 } 197 } 198 exit(0); 199 /* NOTREACHED */ 200 } 201 202 static void 203 usage(void) 204 { 205 (void)fprintf(stderr, "usage: %s [-AadfIis] [name-of-host]\n", 206 getprogname()); 207 exit(1); 208 /* NOTREACHED */ 209 } 210