The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 1 | /* |
| 2 | * mount.c, by rmk |
| 3 | */ |
| 4 | |
| 5 | #include <sys/mount.h> |
| 6 | #include <sys/stat.h> |
| 7 | #include <fcntl.h> |
| 8 | #include <errno.h> |
| 9 | #include <stdio.h> |
| 10 | #include <stdlib.h> |
| 11 | #include <string.h> |
| 12 | #include <unistd.h> |
| 13 | |
| 14 | #include <linux/loop.h> |
| 15 | |
| 16 | #define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0])) |
| 17 | |
Ken Sumrall | 940c810 | 2011-07-12 19:47:06 -0700 | [diff] [blame] | 18 | #define DEFAULT_LOOP_DEVICE "/dev/block/loop0" |
| 19 | #define LOOPDEV_MAXLEN 64 |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 20 | |
| 21 | struct mount_opts { |
| 22 | const char str[8]; |
| 23 | unsigned long rwmask; |
| 24 | unsigned long rwset; |
| 25 | unsigned long rwnoset; |
| 26 | }; |
| 27 | |
| 28 | struct extra_opts { |
| 29 | char *str; |
| 30 | char *end; |
| 31 | int used_size; |
| 32 | int alloc_size; |
| 33 | }; |
| 34 | |
| 35 | /* |
| 36 | * These options define the function of "mount(2)". |
| 37 | */ |
| 38 | #define MS_TYPE (MS_REMOUNT|MS_BIND|MS_MOVE) |
| 39 | |
| 40 | |
| 41 | static const struct mount_opts options[] = { |
| 42 | /* name mask set noset */ |
| 43 | { "async", MS_SYNCHRONOUS, 0, MS_SYNCHRONOUS }, |
| 44 | { "atime", MS_NOATIME, 0, MS_NOATIME }, |
| 45 | { "bind", MS_TYPE, MS_BIND, 0, }, |
| 46 | { "dev", MS_NODEV, 0, MS_NODEV }, |
| 47 | { "diratime", MS_NODIRATIME, 0, MS_NODIRATIME }, |
| 48 | { "dirsync", MS_DIRSYNC, MS_DIRSYNC, 0 }, |
| 49 | { "exec", MS_NOEXEC, 0, MS_NOEXEC }, |
| 50 | { "move", MS_TYPE, MS_MOVE, 0 }, |
| 51 | { "recurse", MS_REC, MS_REC, 0 }, |
| 52 | { "remount", MS_TYPE, MS_REMOUNT, 0 }, |
| 53 | { "ro", MS_RDONLY, MS_RDONLY, 0 }, |
| 54 | { "rw", MS_RDONLY, 0, MS_RDONLY }, |
| 55 | { "suid", MS_NOSUID, 0, MS_NOSUID }, |
| 56 | { "sync", MS_SYNCHRONOUS, MS_SYNCHRONOUS, 0 }, |
| 57 | { "verbose", MS_VERBOSE, MS_VERBOSE, 0 }, |
| 58 | }; |
| 59 | |
| 60 | static void add_extra_option(struct extra_opts *extra, char *s) |
| 61 | { |
| 62 | int len = strlen(s); |
| 63 | int newlen = extra->used_size + len; |
| 64 | |
| 65 | if (extra->str) |
| 66 | len++; /* +1 for ',' */ |
| 67 | |
| 68 | if (newlen >= extra->alloc_size) { |
| 69 | char *new; |
| 70 | |
| 71 | new = realloc(extra->str, newlen + 1); /* +1 for NUL */ |
| 72 | if (!new) |
| 73 | return; |
| 74 | |
| 75 | extra->str = new; |
| 76 | extra->end = extra->str + extra->used_size; |
| 77 | extra->alloc_size = newlen; |
| 78 | } |
| 79 | |
| 80 | if (extra->used_size) { |
| 81 | *extra->end = ','; |
| 82 | extra->end++; |
| 83 | } |
| 84 | strcpy(extra->end, s); |
| 85 | extra->used_size += len; |
| 86 | |
| 87 | } |
| 88 | |
| 89 | static unsigned long |
Ken Sumrall | 940c810 | 2011-07-12 19:47:06 -0700 | [diff] [blame] | 90 | parse_mount_options(char *arg, unsigned long rwflag, struct extra_opts *extra, int* loop, char *loopdev) |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 91 | { |
| 92 | char *s; |
| 93 | |
| 94 | *loop = 0; |
| 95 | while ((s = strsep(&arg, ",")) != NULL) { |
| 96 | char *opt = s; |
| 97 | unsigned int i; |
| 98 | int res, no = s[0] == 'n' && s[1] == 'o'; |
| 99 | |
| 100 | if (no) |
| 101 | s += 2; |
| 102 | |
Ken Sumrall | 940c810 | 2011-07-12 19:47:06 -0700 | [diff] [blame] | 103 | if (strncmp(s, "loop=", 5) == 0) { |
| 104 | *loop = 1; |
| 105 | strlcpy(loopdev, s + 5, LOOPDEV_MAXLEN); |
| 106 | continue; |
| 107 | } |
| 108 | |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 109 | if (strcmp(s, "loop") == 0) { |
| 110 | *loop = 1; |
Ken Sumrall | 940c810 | 2011-07-12 19:47:06 -0700 | [diff] [blame] | 111 | strlcpy(loopdev, DEFAULT_LOOP_DEVICE, LOOPDEV_MAXLEN); |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 112 | continue; |
| 113 | } |
| 114 | for (i = 0, res = 1; i < ARRAY_SIZE(options); i++) { |
| 115 | res = strcmp(s, options[i].str); |
| 116 | |
| 117 | if (res == 0) { |
| 118 | rwflag &= ~options[i].rwmask; |
| 119 | if (no) |
| 120 | rwflag |= options[i].rwnoset; |
| 121 | else |
| 122 | rwflag |= options[i].rwset; |
| 123 | } |
| 124 | if (res <= 0) |
| 125 | break; |
| 126 | } |
| 127 | |
| 128 | if (res != 0 && s[0]) |
| 129 | add_extra_option(extra, opt); |
| 130 | } |
| 131 | |
| 132 | return rwflag; |
| 133 | } |
| 134 | |
| 135 | static char *progname; |
| 136 | |
| 137 | static struct extra_opts extra; |
| 138 | static unsigned long rwflag; |
| 139 | |
| 140 | static int |
Ken Sumrall | 940c810 | 2011-07-12 19:47:06 -0700 | [diff] [blame] | 141 | do_mount(char *dev, char *dir, char *type, unsigned long rwflag, void *data, int loop, |
| 142 | char *loopdev) |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 143 | { |
| 144 | char *s; |
| 145 | int error = 0; |
| 146 | |
| 147 | if (loop) { |
| 148 | int file_fd, device_fd; |
Jay Freeman (saurik) | bc7b0cb | 2008-11-16 13:25:10 +0000 | [diff] [blame] | 149 | int flags; |
| 150 | |
| 151 | flags = (rwflag & MS_RDONLY) ? O_RDONLY : O_RDWR; |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 152 | |
Jay Freeman (saurik) | bc7b0cb | 2008-11-16 13:25:10 +0000 | [diff] [blame] | 153 | file_fd = open(dev, flags); |
Ken Sumrall | 940c810 | 2011-07-12 19:47:06 -0700 | [diff] [blame] | 154 | if (file_fd < 0) { |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 155 | perror("open backing file failed"); |
| 156 | return 1; |
| 157 | } |
Ken Sumrall | 940c810 | 2011-07-12 19:47:06 -0700 | [diff] [blame] | 158 | device_fd = open(loopdev, flags); |
| 159 | if (device_fd < 0) { |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 160 | perror("open loop device failed"); |
| 161 | close(file_fd); |
| 162 | return 1; |
| 163 | } |
| 164 | if (ioctl(device_fd, LOOP_SET_FD, file_fd) < 0) { |
| 165 | perror("ioctl LOOP_SET_FD failed"); |
| 166 | close(file_fd); |
| 167 | close(device_fd); |
| 168 | return 1; |
| 169 | } |
| 170 | |
| 171 | close(file_fd); |
| 172 | close(device_fd); |
Ken Sumrall | 940c810 | 2011-07-12 19:47:06 -0700 | [diff] [blame] | 173 | dev = loopdev; |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 174 | } |
| 175 | |
| 176 | while ((s = strsep(&type, ",")) != NULL) { |
| 177 | retry: |
| 178 | if (mount(dev, dir, s, rwflag, data) == -1) { |
| 179 | error = errno; |
| 180 | /* |
| 181 | * If the filesystem is not found, or the |
| 182 | * superblock is invalid, try the next. |
| 183 | */ |
| 184 | if (error == ENODEV || error == EINVAL) |
| 185 | continue; |
| 186 | |
| 187 | /* |
| 188 | * If we get EACCESS, and we're trying to |
| 189 | * mount readwrite and this isn't a remount, |
| 190 | * try read only. |
| 191 | */ |
| 192 | if (error == EACCES && |
| 193 | (rwflag & (MS_REMOUNT|MS_RDONLY)) == 0) { |
| 194 | rwflag |= MS_RDONLY; |
| 195 | goto retry; |
| 196 | } |
| 197 | break; |
| 198 | } |
| 199 | } |
| 200 | |
| 201 | if (error) { |
| 202 | errno = error; |
| 203 | perror("mount"); |
| 204 | return 255; |
| 205 | } |
| 206 | |
| 207 | return 0; |
| 208 | } |
| 209 | |
| 210 | static int print_mounts() |
| 211 | { |
| 212 | FILE* f; |
| 213 | int length; |
| 214 | char buffer[100]; |
| 215 | |
| 216 | f = fopen("/proc/mounts", "r"); |
| 217 | if (!f) { |
| 218 | fprintf(stdout, "could not open /proc/mounts\n"); |
| 219 | return -1; |
| 220 | } |
| 221 | |
| 222 | do { |
| 223 | length = fread(buffer, 1, 100, f); |
| 224 | if (length > 0) |
| 225 | fwrite(buffer, 1, length, stdout); |
| 226 | } while (length > 0); |
| 227 | |
| 228 | fclose(f); |
| 229 | return 0; |
| 230 | } |
| 231 | |
Colin Cross | 4e7dd3d | 2010-05-06 16:33:30 -0700 | [diff] [blame] | 232 | static int get_mounts_dev_dir(const char *arg, char **dev, char **dir) |
| 233 | { |
| 234 | FILE *f; |
| 235 | char mount_dev[256]; |
| 236 | char mount_dir[256]; |
| 237 | char mount_type[256]; |
| 238 | char mount_opts[256]; |
| 239 | int mount_freq; |
| 240 | int mount_passno; |
| 241 | int match; |
| 242 | |
| 243 | f = fopen("/proc/mounts", "r"); |
| 244 | if (!f) { |
| 245 | fprintf(stdout, "could not open /proc/mounts\n"); |
| 246 | return -1; |
| 247 | } |
| 248 | |
| 249 | do { |
| 250 | match = fscanf(f, "%255s %255s %255s %255s %d %d\n", |
| 251 | mount_dev, mount_dir, mount_type, |
| 252 | mount_opts, &mount_freq, &mount_passno); |
| 253 | mount_dev[255] = 0; |
| 254 | mount_dir[255] = 0; |
| 255 | mount_type[255] = 0; |
| 256 | mount_opts[255] = 0; |
| 257 | if (match == 6 && |
| 258 | (strcmp(arg, mount_dev) == 0 || |
| 259 | strcmp(arg, mount_dir) == 0)) { |
| 260 | *dev = strdup(mount_dev); |
| 261 | *dir = strdup(mount_dir); |
| 262 | fclose(f); |
| 263 | return 0; |
| 264 | } |
| 265 | } while (match != EOF); |
| 266 | |
| 267 | fclose(f); |
| 268 | return -1; |
| 269 | } |
| 270 | |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 271 | int mount_main(int argc, char *argv[]) |
| 272 | { |
| 273 | char *type = NULL; |
Colin Cross | 4e7dd3d | 2010-05-06 16:33:30 -0700 | [diff] [blame] | 274 | char *dev = NULL; |
| 275 | char *dir = NULL; |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 276 | int c; |
Dima Zavin | 383688b | 2009-06-29 15:50:20 -0700 | [diff] [blame] | 277 | int loop = 0; |
Ken Sumrall | 940c810 | 2011-07-12 19:47:06 -0700 | [diff] [blame] | 278 | char loopdev[LOOPDEV_MAXLEN]; |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 279 | |
| 280 | progname = argv[0]; |
| 281 | rwflag = MS_VERBOSE; |
| 282 | |
| 283 | // mount with no arguments is equivalent to "cat /proc/mounts" |
| 284 | if (argc == 1) return print_mounts(); |
| 285 | |
| 286 | do { |
| 287 | c = getopt(argc, argv, "o:rt:w"); |
| 288 | if (c == EOF) |
| 289 | break; |
| 290 | switch (c) { |
| 291 | case 'o': |
Ken Sumrall | 940c810 | 2011-07-12 19:47:06 -0700 | [diff] [blame] | 292 | rwflag = parse_mount_options(optarg, rwflag, &extra, &loop, loopdev); |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 293 | break; |
| 294 | case 'r': |
| 295 | rwflag |= MS_RDONLY; |
| 296 | break; |
| 297 | case 't': |
| 298 | type = optarg; |
| 299 | break; |
| 300 | case 'w': |
| 301 | rwflag &= ~MS_RDONLY; |
| 302 | break; |
| 303 | case '?': |
| 304 | fprintf(stderr, "%s: invalid option -%c\n", |
| 305 | progname, optopt); |
| 306 | exit(1); |
| 307 | } |
| 308 | } while (1); |
| 309 | |
| 310 | /* |
| 311 | * If remount, bind or move was specified, then we don't |
| 312 | * have a "type" as such. Use the dummy "none" type. |
| 313 | */ |
| 314 | if (rwflag & MS_TYPE) |
| 315 | type = "none"; |
| 316 | |
Colin Cross | 4e7dd3d | 2010-05-06 16:33:30 -0700 | [diff] [blame] | 317 | if (optind + 2 == argc) { |
| 318 | dev = argv[optind]; |
| 319 | dir = argv[optind + 1]; |
| 320 | } else if (optind + 1 == argc && rwflag & MS_REMOUNT) { |
| 321 | get_mounts_dev_dir(argv[optind], &dev, &dir); |
| 322 | } |
| 323 | |
| 324 | if (dev == NULL || dir == NULL || type == NULL) { |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 325 | fprintf(stderr, "Usage: %s [-r] [-w] [-o options] [-t type] " |
| 326 | "device directory\n", progname); |
| 327 | exit(1); |
| 328 | } |
| 329 | |
Ken Sumrall | 940c810 | 2011-07-12 19:47:06 -0700 | [diff] [blame] | 330 | return do_mount(dev, dir, type, rwflag, extra.str, loop, loopdev); |
Colin Cross | 4e7dd3d | 2010-05-06 16:33:30 -0700 | [diff] [blame] | 331 | /* We leak dev and dir in some cases, but we're about to exit */ |
The Android Open Source Project | 4f6e8d7 | 2008-10-21 07:00:00 -0700 | [diff] [blame] | 332 | } |