selinux/chcon.c

   1 /*
   2  * chcon -- change security context, based on coreutils-5.97-13
   3  *
   4  * Port to busybox: KaiGai Kohei <kaigai@kaigai.gr.jp>
   5  *
   6  * Copyright (C) 2006 - 2007 KaiGai Kohei <kaigai@kaigai.gr.jp>
   7  *
   8  * Licensed under GPLv2, see file LICENSE in this source tree.
   9  */
  10 //config:config CHCON
  11 //config:       bool "chcon (8.9 kb)"
  12 //config:       default n
  13 //config:       depends on SELINUX
  14 //config:       help
  15 //config:       Enable support to change the security context of file.
  16
  17 //applet:IF_CHCON(APPLET(chcon, BB_DIR_USR_BIN, BB_SUID_DROP))
  18
  19 //kbuild:lib-$(CONFIG_CHCON) += chcon.o
  20
  21 //usage:#define chcon_trivial_usage
  22 //usage:       "[-chfRv] CONTEXT FILE..."
  23 //usage:       "\n      chcon [-chfRv] [-u USER] [-r ROLE] [-l RANGE] [-t TYPE] FILE..."
  24 //usage:        IF_LONG_OPTS(
  25 //usage:       "\n      chcon [-chfRv] --reference=RFILE FILE..."
  26 //usage:        )
  27 //usage:
  28 //usage:#define chcon_full_usage "\n\n"
  29 //usage:       "Change the security context of FILEs to CONTEXT\n"
  30 //usage:     "\n        -v      Verbose"
  31 //usage:     "\n        -c      Report changes made"
  32 //usage:     "\n        -h      Affect symlinks instead of their targets"
  33 //usage:     "\n        -f      Suppress most error messages"
  34 //usage:        IF_LONG_OPTS(
  35 //usage:     "\n        --reference RFILE Use RFILE's group instead of using a CONTEXT value"
  36 //usage:        )
  37 //usage:     "\n        -u USER Set user/role/type/range in the target security context"
  38 //usage:     "\n        -r ROLE"
  39 //usage:     "\n        -t TYPE"
  40 //usage:     "\n        -l RANGE"
  41 //usage:     "\n        -R      Recurse"
  42
  43 #include <selinux/context.h>
  44
  45 #include "libbb.h"
  46
  47 #define OPT_RECURSIVE           (1<<0)  /* 'R' */
  48 #define OPT_CHANHES             (1<<1)  /* 'c' */
  49 #define OPT_NODEREFERENCE       (1<<2)  /* 'h' */
  50 #define OPT_QUIET               (1<<3)  /* 'f' */
  51 #define OPT_USER                (1<<4)  /* 'u' */
  52 #define OPT_ROLE                (1<<5)  /* 'r' */
  53 #define OPT_TYPE                (1<<6)  /* 't' */
  54 #define OPT_RANGE               (1<<7)  /* 'l' */
  55 #define OPT_VERBOSE             (1<<8)  /* 'v' */
  56 #define OPT_REFERENCE           ((1<<9) * ENABLE_LONG_OPTS)
  57 #define OPT_COMPONENT_SPECIFIED (OPT_USER | OPT_ROLE | OPT_TYPE | OPT_RANGE)
  58
  59 static char *user = NULL;
  60 static char *role = NULL;
  61 static char *type = NULL;
  62 static char *range = NULL;
  63 static char *specified_context = NULL;
  64
  65 static int FAST_FUNC change_filedir_context(struct recursive_state *state UNUSED_PARAM,
  66                 const char *fname,
  67                 struct stat *stbuf UNUSED_PARAM)
  68 {
  69         context_t context = NULL;
  70         security_context_t file_context = NULL;
  71         security_context_t context_string;
  72         int rc = FALSE;
  73         int status = 0;
  74
  75         if (option_mask32 & OPT_NODEREFERENCE) {
  76                 status = lgetfilecon(fname, &file_context);
  77         } else {
  78                 status = getfilecon(fname, &file_context);
  79         }
  80         if (status < 0 && errno != ENODATA) {
  81                 if ((option_mask32 & OPT_QUIET) == 0)
  82                         bb_error_msg("can't obtain security context: %s", fname);
  83                 goto skip;
  84         }
  85
  86         if (file_context == NULL && specified_context == NULL) {
  87                 bb_error_msg("can't apply partial context to unlabeled file %s", fname);
  88                 goto skip;
  89         }
  90
  91         if (specified_context == NULL) {
  92                 context = set_security_context_component(file_context,
  93                                                         user, role, type, range);
  94                 if (!context) {
  95                         bb_error_msg("can't compute security context from %s", file_context);
  96                         goto skip;
  97                 }
  98         } else {
  99                 context = context_new(specified_context);
 100                 if (!context) {
 101                         bb_error_msg("invalid context: %s", specified_context);
 102                         goto skip;
 103                 }
 104         }
 105
 106         context_string = context_str(context);
 107         if (!context_string) {
 108                 bb_simple_error_msg("can't obtain security context in text expression");
 109                 goto skip;
 110         }
 111
 112         if (file_context == NULL || strcmp(context_string, file_context) != 0) {
 113                 int fail;
 114
 115                 if (option_mask32 & OPT_NODEREFERENCE) {
 116                         fail = lsetfilecon(fname, context_string);
 117                 } else {
 118                         fail = setfilecon(fname, context_string);
 119                 }
 120                 if ((option_mask32 & OPT_VERBOSE) || ((option_mask32 & OPT_CHANHES) && !fail)) {
 121                         printf(!fail
 122                                 ? "context of %s changed to %s\n"
 123                                 : "can't change context of %s to %s\n",
 124                                 fname, context_string);
 125                 }
 126                 if (!fail) {
 127                         rc = TRUE;
 128                 } else if ((option_mask32 & OPT_QUIET) == 0) {
 129                         bb_error_msg("can't change context of %s to %s",
 130                                         fname, context_string);
 131                 }
 132         } else {
 133                 if (option_mask32 & OPT_VERBOSE) {
 134                         printf("context of %s retained as %s\n", fname, context_string);
 135                 }
 136                 rc = TRUE;
 137         }
 138 skip:
 139         context_free(context);
 140         freecon(file_context);
 141
 142         return rc;
 143 }
 144
 145 #if ENABLE_LONG_OPTS
 146 static const char chcon_longopts[] ALIGN1 =
 147         "recursive\0"      No_argument       "R"
 148         "changes\0"        No_argument       "c"
 149         "no-dereference\0" No_argument       "h"
 150         "silent\0"         No_argument       "f"
 151         "quiet\0"          No_argument       "f"
 152         "user\0"           Required_argument "u"
 153         "role\0"           Required_argument "r"
 154         "type\0"           Required_argument "t"
 155         "range\0"          Required_argument "l"
 156         "verbose\0"        No_argument       "v"
 157         "reference\0"      Required_argument "\xff" /* no short option */
 158         ;
 159 #endif
 160
 161 int chcon_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 162 int chcon_main(int argc UNUSED_PARAM, char **argv)
 163 {
 164         char *reference_file;
 165         char *fname;
 166         int i, errors = 0;
 167
 168         getopt32long(argv, "^"
 169                 "Rchfu:r:t:l:v"
 170                 "\0"
 171                 "-1" /* at least 1 arg */
 172                 ":?" /* error if exclusivity constraints are violated */
 173 #if ENABLE_LONG_OPTS
 174                 ":\xff--urtl:u--\xff:r--\xff:t--\xff:l--\xff"
 175 #endif
 176                 ":f--v:v--f"  /* 'verbose' and 'quiet' are exclusive */
 177                 , chcon_longopts,
 178                 &user, &role, &type, &range, &reference_file
 179         );
 180         argv += optind;
 181
 182 #if ENABLE_LONG_OPTS
 183         if (option_mask32 & OPT_REFERENCE) {
 184                 /* FIXME: lgetfilecon() should be used when '-h' is specified.
 185                  * But current implementation follows the original one. */
 186                 if (getfilecon(reference_file, &specified_context) < 0)
 187                         bb_perror_msg_and_die("getfilecon('%s') failed", reference_file);
 188         } else
 189 #endif
 190         if ((option_mask32 & OPT_COMPONENT_SPECIFIED) == 0) {
 191                 specified_context = *argv++;
 192                 /* specified_context is never NULL -
 193                  * "-1" in opt_complementary prevents this. */
 194                 if (!argv[0])
 195                         bb_simple_error_msg_and_die("too few arguments");
 196         }
 197
 198         for (i = 0; (fname = argv[i]) != NULL; i++) {
 199                 int fname_len = strlen(fname);
 200                 while (fname_len > 1 && fname[fname_len - 1] == '/')
 201                         fname_len--;
 202                 fname[fname_len] = '\0';
 203
 204                 if (recursive_action(fname,
 205                                         ((option_mask32 & OPT_RECURSIVE) ? ACTION_RECURSE : 0),
 206                                         change_filedir_context,
 207                                         change_filedir_context,
 208                                         NULL) != TRUE)
 209                         errors = 1;
 210         }
 211         return errors;
 212 }