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 /* 17 SYNOPSIS 18 void login_fbtab(tty, uid, gid) 19 char *tty; 20 uid_t uid; 21 gid_t gid; 22 23 DESCRIPTION 24 This module implements device security as described in the 25 SunOS 4.1.x fbtab(5) and SunOS 5.x logindevperm(4) manual 26 pages. The program first looks for /etc/fbtab. If that file 27 cannot be opened it attempts to process /etc/logindevperm. 28 We expect entries with the following format: 29 30 Comments start with a # and extend to the end of the line. 31 32 Blank lines or lines with only a comment are ignored. 33 34 All other lines consist of three fields delimited by 35 whitespace: a login device (/dev/console), an octal 36 permission number (0600), and a ":"-delimited list of 37 devices (/dev/kbd:/dev/mouse). All device names are 38 absolute paths. A path that ends in "*" refers to all 39 directory entries except "." and "..". 40 41 If the tty argument (relative path) matches a login device 42 name (absolute path), the permissions of the devices in the 43 ":"-delimited list are set as specified in the second 44 field, and their ownership is changed to that of the uid 45 and gid arguments. 46 47 DIAGNOSTICS 48 Problems are reported via the syslog daemon with severity 49 LOG_ERR. 50 51 BUGS 52 This module uses strtok(3), which may cause conflicts with other 53 uses of that same routine. 54 55 AUTHOR 56 Wietse Venema (wietse@wzv.win.tue.nl) 57 Eindhoven University of Technology 58 The Netherlands 59 */ 60 61 #include <sys/cdefs.h> 62 __FBSDID("$FreeBSD$"); 63 64 #include <sys/types.h> 65 #include <sys/stat.h> 66 #include <errno.h> 67 #include <glob.h> 68 #include <paths.h> 69 #include <stdio.h> 70 #include <string.h> 71 #include <syslog.h> 72 #include <unistd.h> 73 74 #include "login.h" 75 #include "pathnames.h" 76 77 static void login_protect(const char *, char *, int, uid_t, gid_t); 78 79 #define WSPACE " \t\n" 80 81 /* login_fbtab - apply protections specified in /etc/fbtab or logindevperm */ 82 83 void 84 login_fbtab(char *tty, uid_t uid, gid_t gid) 85 { 86 FILE *fp; 87 char buf[BUFSIZ]; 88 char *devname; 89 char *cp; 90 int prot; 91 const char *table; 92 93 if ((fp = fopen(table = _PATH_FBTAB, "r")) == NULL 94 && (fp = fopen(table = _PATH_LOGINDEVPERM, "r")) == NULL) 95 return; 96 97 while (fgets(buf, sizeof(buf), fp)) { 98 if ((cp = strchr(buf, '#'))) 99 *cp = 0; /* strip comment */ 100 if ((cp = devname = strtok(buf, WSPACE)) == 0) 101 continue; /* empty or comment */ 102 if (strncmp(devname, _PATH_DEV, sizeof _PATH_DEV - 1) != 0 103 || (cp = strtok(NULL, WSPACE)) == 0 104 || *cp != '0' 105 || sscanf(cp, "%o", &prot) == 0 106 || prot == 0 107 || (prot & 0777) != prot 108 || (cp = strtok(NULL, WSPACE)) == 0) { 109 syslog(LOG_ERR, "%s: bad entry: %s", table, cp ? cp : "(null)"); 110 continue; 111 } 112 if (strcmp(devname + 5, tty) == 0) { 113 for (cp = strtok(cp, ":"); cp; cp = strtok(NULL, ":")) { 114 login_protect(table, cp, prot, uid, gid); 115 } 116 } 117 } 118 fclose(fp); 119 } 120 121 /* login_protect - protect one device entry */ 122 123 void 124 login_protect(const char *table, char *pattern, int mask, uid_t uid, gid_t gid) 125 { 126 glob_t gl; 127 char *path; 128 unsigned int i; 129 130 if (glob(pattern, GLOB_NOSORT, NULL, &gl) != 0) 131 return; 132 for (i = 0; i < gl.gl_pathc; i++) { 133 path = gl.gl_pathv[i]; 134 /* clear flags of the device */ 135 if (chflags(path, 0) && errno != ENOENT && errno != EOPNOTSUPP) 136 syslog(LOG_ERR, "%s: chflags(%s): %m", table, path); 137 if (chmod(path, mask) && errno != ENOENT) 138 syslog(LOG_ERR, "%s: chmod(%s): %m", table, path); 139 if (chown(path, uid, gid) && errno != ENOENT) 140 syslog(LOG_ERR, "%s: chown(%s): %m", table, path); 141 } 142 globfree(&gl); 143 } 144