1 /*- 2 * Copyright (c) 2001 Brian Somers <brian@Awfulhak.org> 3 * Based on original work by Atsushi Murai <amurai@FreeBSD.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 34 #include <libutil.h> 35 #include <string.h> 36 #include <unistd.h> 37 38 static int isDISP(const char *); 39 40 /*- 41 * Trim the current domain name from fullhost, but only if the result 42 * is less than or equal to hostsize in length. 43 * 44 * This function understands $DISPLAY type fullhosts. 45 * 46 * For example: 47 * 48 * trimdomain("abcde.my.domain", 5) -> "abcde" 49 * trimdomain("abcde.my.domain", 4) -> "abcde.my.domain" 50 * trimdomain("abcde.my.domain:0.0", 9) -> "abcde:0.0" 51 * trimdomain("abcde.my.domain:0.0", 8) -> "abcde.my.domain:0.0" 52 */ 53 void 54 trimdomain(char *fullhost, int hostsize) 55 { 56 static size_t dlen; 57 static int first = 1; 58 static char domain[MAXHOSTNAMELEN]; 59 char *end, *s; 60 size_t len; 61 62 if (first) { 63 /* XXX: Should we assume that our domain is this persistent ? */ 64 first = 0; 65 if (gethostname(domain, sizeof(domain) - 1) == 0 && 66 (s = strchr(domain, '.')) != NULL) 67 memmove(domain, s + 1, strlen(s + 1) + 1); 68 else 69 domain[0] = '\0'; 70 dlen = strlen(domain); 71 } 72 73 if (domain[0] == '\0') 74 return; 75 76 s = fullhost; 77 end = s + hostsize + 1; 78 if ((s = memchr(s, '.', (size_t)(end - s))) != NULL) { 79 if (strncasecmp(s + 1, domain, dlen) == 0) { 80 if (s[dlen + 1] == '\0') { 81 /* Found -- lose the domain. */ 82 *s = '\0'; 83 } else if (s[dlen + 1] == ':' && 84 isDISP(s + dlen + 2) && 85 (len = strlen(s + dlen + 1)) < (size_t)(end - s)) { 86 /* Found -- shuffle the DISPLAY back. */ 87 memmove(s, s + dlen + 1, len + 1); 88 } 89 } 90 } 91 } 92 93 /* 94 * Is the given string NN or NN.NN where ``NN'' is an all-numeric string ? 95 */ 96 static int 97 isDISP(const char *disp) 98 { 99 size_t w; 100 int res; 101 102 w = strspn(disp, "0123456789"); 103 res = 0; 104 if (w > 0) { 105 if (disp[w] == '\0') 106 res = 1; /* NN */ 107 else if (disp[w] == '.') { 108 disp += w + 1; 109 w = strspn(disp, "0123456789"); 110 if (w > 0 && disp[w] == '\0') 111 res = 1; /* NN.NN */ 112 } 113 } 114 return (res); 115 } 116