1 /* $NetBSD: ttyaction.c,v 1.19 2008/04/28 20:23:03 martin Exp $ */ 2 3 /*- 4 * Copyright (c) 1996 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Gordon W. Ross. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * For each matching "tty" and "action" run the "command." 34 * See fnmatch() for matching the tty name. 35 */ 36 37 #include <sys/cdefs.h> 38 #if defined(LIBC_SCCS) && !defined(lint) 39 __RCSID("$NetBSD: ttyaction.c,v 1.19 2008/04/28 20:23:03 martin Exp $"); 40 #endif /* LIBC_SCCS and not lint */ 41 42 #include <sys/types.h> 43 #include <sys/wait.h> 44 45 #include <assert.h> 46 #include <err.h> 47 #include <errno.h> 48 #include <fcntl.h> 49 #include <fnmatch.h> 50 #include <paths.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <unistd.h> 55 56 #include "util.h" 57 58 #ifndef _PATH_TTYACTION 59 #define _PATH_TTYACTION "/etc/ttyaction" 60 #endif 61 62 static const char *actfile = _PATH_TTYACTION; 63 static const char *pathenv = "PATH=" _PATH_STDPATH; 64 65 int 66 ttyaction(const char *tty, const char *act, const char *user) 67 { 68 FILE *fp; 69 char *p1, *p2; 70 const char *argv[4]; 71 const char *envp[8]; 72 char *lastp; 73 char line[1024]; 74 char env_tty[64]; 75 char env_act[64]; 76 char env_user[256]; 77 int error, linenum, status; 78 pid_t pid; 79 80 _DIAGASSERT(tty != NULL); 81 _DIAGASSERT(act != NULL); 82 _DIAGASSERT(user != NULL); 83 84 fp = fopen(actfile, "r"); 85 if (fp == NULL) 86 return 0; 87 88 /* Skip the "/dev/" part of the first arg. */ 89 if (!strncmp(tty, "/dev/", (size_t)5)) 90 tty += 5; 91 92 /* Args will be: "sh -c ..." */ 93 argv[0] = _PATH_BSHELL; 94 argv[1] = "-c"; 95 argv[2] = NULL; /* see below */ 96 argv[3] = NULL; 97 98 /* 99 * Environment needs: TTY, ACT, USER 100 */ 101 snprintf(env_tty, sizeof(env_tty), "TTY=%s", tty); 102 snprintf(env_act, sizeof(env_act), "ACT=%s", act); 103 snprintf(env_user, sizeof(env_user), "USER=%s", user); 104 envp[0] = pathenv; 105 envp[1] = env_tty; 106 envp[2] = env_act; 107 envp[3] = env_user; 108 envp[4] = NULL; 109 110 linenum = 0; 111 status = 0; 112 while (fgets(line, (int)sizeof(line), fp)) { 113 linenum++; 114 115 /* Allow comment lines. */ 116 if (line[0] == '#') 117 continue; 118 119 p1 = strtok_r(line, " \t", &lastp); 120 p2 = strtok_r(NULL, " \t", &lastp); 121 /* This arg goes to end of line. */ 122 argv[2] = strtok_r(NULL, "\n", &lastp); 123 if (!p1 || !p2 || !argv[2]) { 124 warnx("%s: line %d format error", actfile, linenum); 125 continue; 126 } 127 if (fnmatch(p1, tty, 0) || fnmatch(p2, act, 0)) 128 continue; 129 /* OK, this is a match. Run the command. */ 130 pid = fork(); 131 if (pid == -1) { 132 warnx("fork failed: %s", strerror(errno)); 133 continue; 134 } 135 if (pid == 0) { 136 /* This is the child. */ 137 error = execve(argv[0], 138 (char *const *)__UNCONST(argv), 139 (char *const *)__UNCONST(envp)); 140 /* If we get here, it is an error. */ 141 warnx("%s: line %d: exec failed: %s", 142 actfile, linenum, strerror(errno)); 143 _exit(1); 144 } 145 /* This is the parent. */ 146 error = waitpid(pid, &status, 0); 147 if (error == -1) { 148 warnx("%s: line %d: wait failed: %s", 149 actfile, linenum, strerror(errno)); 150 continue; 151 } 152 if (WTERMSIG(status)) { 153 warnx("%s: line %d: child died with signal %d", 154 actfile, linenum, WTERMSIG(status)); 155 continue; 156 } 157 } 158 fclose(fp); 159 return status; 160 } 161