1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <stdio.h> 18 #include <stdlib.h> 19 #include <sys/stat.h> 20 #include <errno.h> 21 #include <unistd.h> 22 #include <string.h> 23 #include <inttypes.h> 24 25 #include <selinux/selinux.h> 26 #include <selinux/label.h> 27 28 #include "private/android_filesystem_config.h" 29 30 // This program takes a list of files and directories (indicated by a 31 // trailing slash) on the stdin, and prints to stdout each input 32 // filename along with its desired uid, gid, and mode (in octal). 33 // The leading slash should be stripped from the input. 34 // 35 // After the first 4 columns, optional key=value pairs are emitted 36 // for each file. Currently, the following keys are supported: 37 // * -S: selabel=[selinux_label] 38 // * -C: capabilities=[hex capabilities value] 39 // 40 // Example input: 41 // 42 // system/etc/dbus.conf 43 // data/app/ 44 // 45 // Output: 46 // 47 // system/etc/dbus.conf 1002 1002 440 48 // data/app 1000 1000 771 49 // 50 // or if, for example, -S is used: 51 // 52 // system/etc/dbus.conf 1002 1002 440 selabel=u:object_r:system_file:s0 53 // data/app 1000 1000 771 selabel=u:object_r:apk_data_file:s0 54 // 55 // Note that the output will omit the trailing slash from 56 // directories. 57 58 static struct selabel_handle* get_sehnd(const char* context_file) { 59 struct selinux_opt seopts[] = { { SELABEL_OPT_PATH, context_file } }; 60 struct selabel_handle* sehnd = selabel_open(SELABEL_CTX_FILE, seopts, 1); 61 62 if (!sehnd) { 63 perror("error running selabel_open"); 64 exit(EXIT_FAILURE); 65 } 66 return sehnd; 67 } 68 69 static void usage() { 70 fprintf(stderr, "Usage: fs_config [-D product_out_path] [-S context_file] [-R root] [-C]\n"); 71 } 72 73 int main(int argc, char** argv) { 74 char buffer[1024]; 75 const char* context_file = NULL; 76 const char* product_out_path = NULL; 77 char* root_path = NULL; 78 struct selabel_handle* sehnd = NULL; 79 int print_capabilities = 0; 80 int opt; 81 while((opt = getopt(argc, argv, "CS:R:D:")) != -1) { 82 switch(opt) { 83 case 'C': 84 print_capabilities = 1; 85 break; 86 case 'S': 87 context_file = optarg; 88 break; 89 case 'R': 90 root_path = optarg; 91 break; 92 case 'D': 93 product_out_path = optarg; 94 break; 95 default: 96 usage(); 97 exit(EXIT_FAILURE); 98 } 99 } 100 101 if (context_file != NULL) { 102 sehnd = get_sehnd(context_file); 103 } 104 105 if (root_path != NULL) { 106 size_t root_len = strlen(root_path); 107 /* Trim any trailing slashes from the root path. */ 108 while (root_len && root_path[--root_len] == '/') { 109 root_path[root_len] = '\0'; 110 } 111 } 112 113 while (fgets(buffer, 1023, stdin) != NULL) { 114 int is_dir = 0; 115 int i; 116 for (i = 0; i < 1024 && buffer[i]; ++i) { 117 switch (buffer[i]) { 118 case '\n': 119 buffer[i-is_dir] = '\0'; 120 if (i == 0) { 121 is_dir = 1; // empty line is considered as root directory 122 } 123 i = 1025; 124 break; 125 case '/': 126 is_dir = 1; 127 break; 128 default: 129 is_dir = 0; 130 break; 131 } 132 } 133 134 unsigned uid = 0, gid = 0, mode = 0; 135 uint64_t capabilities; 136 fs_config(buffer, is_dir, product_out_path, &uid, &gid, &mode, &capabilities); 137 if (root_path != NULL && strcmp(buffer, root_path) == 0) { 138 /* The root of the filesystem needs to be an empty string. */ 139 strcpy(buffer, ""); 140 } 141 printf("%s %d %d %o", buffer, uid, gid, mode); 142 143 if (sehnd != NULL) { 144 size_t buffer_strlen = strnlen(buffer, sizeof(buffer)); 145 if (buffer_strlen >= sizeof(buffer)) { 146 fprintf(stderr, "non null terminated buffer, aborting\n"); 147 exit(EXIT_FAILURE); 148 } 149 size_t full_name_size = buffer_strlen + 2; 150 char* full_name = (char*) malloc(full_name_size); 151 if (full_name == NULL) { 152 perror("malloc"); 153 exit(EXIT_FAILURE); 154 } 155 156 full_name[0] = '/'; 157 strncpy(full_name + 1, buffer, full_name_size - 1); 158 full_name[full_name_size - 1] = '\0'; 159 160 char* secontext; 161 if (selabel_lookup(sehnd, &secontext, full_name, ( mode | (is_dir ? S_IFDIR : S_IFREG)))) { 162 secontext = strdup("u:object_r:unlabeled:s0"); 163 } 164 165 printf(" selabel=%s", secontext); 166 free(full_name); 167 freecon(secontext); 168 } 169 170 if (print_capabilities) { 171 printf(" capabilities=0x%" PRIx64, capabilities); 172 } 173 174 printf("\n"); 175 } 176 return 0; 177 } 178
