1 /************************************************************************ 2 * Copyright 1995 by Wietse Venema. All rights reserved. 3 * 4 * This material was originally written and compiled by Wietse Venema at 5 * Eindhoven University of Technology, The Netherlands, in 1990, 1991, 6 * 1992, 1993, 1994 and 1995. 7 * 8 * Redistribution and use in source and binary forms are permitted 9 * provided that this entire copyright notice is duplicated in all such 10 * copies. 11 * 12 * This software is provided "as is" and without any expressed or implied 13 * warranties, including, without limitation, the implied warranties of 14 * merchantibility and fitness for any particular purpose. 15 ************************************************************************/ 16 /* $FreeBSD: src/usr.bin/login/login_fbtab.c,v 1.18 2007/09/21 01:55:11 kevlo Exp $ */ 17 /* $DragonFly: src/usr.bin/login/login_fbtab.c,v 1.3 2003/10/04 20:36:48 hmp Exp $ */ 18 /* 19 SYNOPSIS 20 void login_fbtab(tty, uid, gid) 21 char *tty; 22 uid_t uid; 23 gid_t gid; 24 25 DESCRIPTION 26 This module implements device security as described in the 27 SunOS 4.1.x fbtab(5) and SunOS 5.x logindevperm(4) manual 28 pages. The program first looks for /etc/fbtab. If that file 29 cannot be opened it attempts to process /etc/logindevperm. 30 We expect entries with the folowing format: 31 32 Comments start with a # and extend to the end of the line. 33 34 Blank lines or lines with only a comment are ignored. 35 36 All other lines consist of three fields delimited by 37 whitespace: a login device (/dev/console), an octal 38 permission number (0600), and a ":"-delimited list of 39 devices (/dev/kbd:/dev/mouse). All device names are 40 absolute paths. A path that ends in "*" refers to all 41 directory entries except "." and "..". 42 43 If the tty argument (relative path) matches a login device 44 name (absolute path), the permissions of the devices in the 45 ":"-delimited list are set as specified in the second 46 field, and their ownership is changed to that of the uid 47 and gid arguments. 48 49 DIAGNOSTICS 50 Problems are reported via the syslog daemon with severity 51 LOG_ERR. 52 53 BUGS 54 This module uses strtok(3), which may cause conflicts with other 55 uses of that same routine. 56 57 AUTHOR 58 Wietse Venema (wietse@wzv.win.tue.nl) 59 Eindhoven University of Technology 60 The Netherlands 61 */ 62 63 #include <sys/types.h> 64 #include <sys/stat.h> 65 #include <errno.h> 66 #include <glob.h> 67 #include <paths.h> 68 #include <stdio.h> 69 #include <string.h> 70 #include <syslog.h> 71 #include <unistd.h> 72 73 #include "login.h" 74 #include "pathnames.h" 75 76 static void login_protect(const char *, char *, int, uid_t, gid_t); 77 78 #define WSPACE " \t\n" 79 80 /* login_fbtab - apply protections specified in /etc/fbtab or logindevperm */ 81 82 void 83 login_fbtab(char *tty, uid_t uid, gid_t gid) 84 { 85 FILE *fp; 86 char buf[BUFSIZ]; 87 char *devname; 88 char *cp; 89 int prot; 90 const char *table; 91 92 if ((fp = fopen(table = _PATH_FBTAB, "r")) == NULL 93 && (fp = fopen(table = _PATH_LOGINDEVPERM, "r")) == NULL) 94 return; 95 96 while (fgets(buf, sizeof(buf), fp)) { 97 if ((cp = strchr(buf, '#'))) 98 *cp = 0; /* strip comment */ 99 if ((cp = devname = strtok(buf, WSPACE)) == 0) 100 continue; /* empty or comment */ 101 if (strncmp(devname, _PATH_DEV, sizeof _PATH_DEV - 1) != 0 102 || (cp = strtok((char *) 0, WSPACE)) == 0 103 || *cp != '0' 104 || sscanf(cp, "%o", &prot) == 0 105 || prot == 0 106 || (prot & 0777) != prot 107 || (cp = strtok((char *) 0, WSPACE)) == 0) { 108 syslog(LOG_ERR, "%s: bad entry: %s", table, cp ? cp : "(null)"); 109 continue; 110 } 111 if (strcmp(devname + 5, tty) == 0) { 112 for (cp = strtok(cp, ":"); cp; cp = strtok((char *) 0, ":")) { 113 login_protect(table, cp, prot, uid, gid); 114 } 115 } 116 } 117 fclose(fp); 118 } 119 120 /* login_protect - protect one device entry */ 121 122 void 123 login_protect(const char *table, char *pattern, int mask, uid_t uid, gid_t gid) 124 { 125 glob_t gl; 126 char *path; 127 unsigned int i; 128 129 if (glob(pattern, GLOB_NOSORT, NULL, &gl) != 0) 130 return; 131 for (i = 0; i < gl.gl_pathc; i++) { 132 path = gl.gl_pathv[i]; 133 /* clear flags of the device */ 134 if (chflags(path, 0) && errno != ENOENT && errno != EOPNOTSUPP) 135 syslog(LOG_ERR, "%s: chflags(%s): %m", table, path); 136 if (chmod(path, mask) && errno != ENOENT) 137 syslog(LOG_ERR, "%s: chmod(%s): %m", table, path); 138 if (chown(path, uid, gid) && errno != ENOENT) 139 syslog(LOG_ERR, "%s: chown(%s): %m", table, path); 140 } 141 globfree(&gl); 142 } 143