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 31#include <sys/param.h> 32 33#include <libutil.h> 34#include <string.h> 35#include <unistd.h> 36 37void trimdomain(char *_fullhost, size_t _hostsize); 38 39static int isDISP(const char *); 40 41/*- 42 * Trim the current domain name from fullhost, but only if the result 43 * is less than or equal to hostsize in length. 44 * 45 * This function understands $DISPLAY type fullhosts. 46 * 47 * For example: 48 * 49 * trimdomain("abcde.my.domain", 5) -> "abcde" 50 * trimdomain("abcde.my.domain", 4) -> "abcde.my.domain" 51 * trimdomain("abcde.my.domain:0.0", 9) -> "abcde:0.0" 52 * trimdomain("abcde.my.domain:0.0", 8) -> "abcde.my.domain:0.0" 53 */ 54void 55trimdomain(char *fullhost, size_t hostsize) 56{ 57 static size_t dlen; 58 static int first = 1; 59 static char domain[MAXHOSTNAMELEN]; 60 char *end, *s; 61 size_t len; 62 63 if (first) { 64 /* XXX: Should we assume that our domain is this persistent ? */ 65 first = 0; 66 if (gethostname(domain, sizeof(domain) - 1) == 0 && 67 (s = strchr(domain, '.')) != NULL) 68 memmove(domain, s + 1, strlen(s + 1) + 1); 69 else 70 domain[0] = '\0'; 71 dlen = strlen(domain); 72 } 73 74 if (domain[0] == '\0') 75 return; 76 77 s = fullhost; 78 end = (char *)((uintptr_t)s + hostsize + 1); 79 if ((s = memchr(s, '.', (size_t)(end - s))) != NULL) { 80 if (strncasecmp(s + 1, domain, dlen) == 0) { 81 if (s[dlen + 1] == '\0') { 82 /* Found -- lose the domain. */ 83 *s = '\0'; 84 } else if (s[dlen + 1] == ':' && 85 isDISP(s + dlen + 2) && 86 (len = strlen(s + dlen + 1)) < (size_t)(end - s)) { 87 /* Found -- shuffle the DISPLAY back. */ 88 memmove(s, s + dlen + 1, len + 1); 89 } 90 } 91 } 92} 93 94/* 95 * Is the given string NN or NN.NN where ``NN'' is an all-numeric string ? 96 */ 97static int 98isDISP(const char *disp) 99{ 100 size_t w; 101 int res; 102 103 w = strspn(disp, "0123456789"); 104 res = 0; 105 if (w > 0) { 106 if (disp[w] == '\0') 107 res = 1; /* NN */ 108 else if (disp[w] == '.') { 109 disp += w + 1; 110 w = strspn(disp, "0123456789"); 111 if (w > 0 && disp[w] == '\0') 112 res = 1; /* NN.NN */ 113 } 114 } 115 return (res); 116} 117