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 1.6.2.4 2001/12/14 10:58:18 rwatson Exp $ */ 17 /* $DragonFly: src/usr.bin/login/login_fbtab.c,v 1.2 2003/06/17 04:29:28 dillon 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 <stdio.h> 66 #include <syslog.h> 67 #include <string.h> 68 #include <errno.h> 69 #include <glob.h> 70 #include <paths.h> 71 #include <unistd.h> 72 #include "pathnames.h" 73 74 void login_protect __P((char *, char *, int, uid_t, gid_t)); 75 void login_fbtab __P((char *tty, uid_t uid, gid_t gid)); 76 77 #define WSPACE " \t\n" 78 79 /* login_fbtab - apply protections specified in /etc/fbtab or logindevperm */ 80 81 void 82 login_fbtab(tty, uid, gid) 83 char *tty; 84 uid_t uid; 85 gid_t gid; 86 { 87 FILE *fp; 88 char buf[BUFSIZ]; 89 char *devname; 90 char *cp; 91 int prot; 92 char *table; 93 94 if ((fp = fopen(table = _PATH_FBTAB, "r")) == 0 95 && (fp = fopen(table = _PATH_LOGINDEVPERM, "r")) == 0) 96 return; 97 98 while (fgets(buf, sizeof(buf), fp)) { 99 if ((cp = strchr(buf, '#'))) 100 *cp = 0; /* strip comment */ 101 if ((cp = devname = strtok(buf, WSPACE)) == 0) 102 continue; /* empty or comment */ 103 if (strncmp(devname, _PATH_DEV, sizeof _PATH_DEV - 1) != 0 104 || (cp = strtok((char *) 0, WSPACE)) == 0 105 || *cp != '0' 106 || sscanf(cp, "%o", &prot) == 0 107 || prot == 0 108 || (prot & 0777) != prot 109 || (cp = strtok((char *) 0, WSPACE)) == 0) { 110 syslog(LOG_ERR, "%s: bad entry: %s", table, cp ? cp : "(null)"); 111 continue; 112 } 113 if (strcmp(devname + 5, tty) == 0) { 114 for (cp = strtok(cp, ":"); cp; cp = strtok((char *) 0, ":")) { 115 login_protect(table, cp, prot, uid, gid); 116 } 117 } 118 } 119 fclose(fp); 120 } 121 122 /* login_protect - protect one device entry */ 123 124 void 125 login_protect(table, pattern, mask, uid, gid) 126 char *table; 127 char *pattern; 128 int mask; 129 uid_t uid; 130 gid_t gid; 131 { 132 glob_t gl; 133 char *path; 134 int i; 135 136 if (glob(pattern, GLOB_NOSORT, NULL, &gl) != 0) 137 return; 138 for (i = 0; i < gl.gl_pathc; i++) { 139 path = gl.gl_pathv[i]; 140 /* clear flags of the device */ 141 if (chflags(path, 0) && errno != ENOENT && errno != EOPNOTSUPP) 142 syslog(LOG_ERR, "%s: chflags(%s): %m", table, path); 143 if (chmod(path, mask) && errno != ENOENT) 144 syslog(LOG_ERR, "%s: chmod(%s): %m", table, path); 145 if (chown(path, uid, gid) && errno != ENOENT) 146 syslog(LOG_ERR, "%s: chown(%s): %m", table, path); 147 } 148 globfree(&gl); 149 } 150