| /* |
| * Copyright (C) 2012 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| /* TO DO: |
| * 1. Re-direct fsck output to the kernel log? |
| * |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <fcntl.h> |
| #include <ctype.h> |
| #include <sys/mount.h> |
| #include <sys/stat.h> |
| #include <errno.h> |
| #include <sys/types.h> |
| #include <sys/wait.h> |
| #include <libgen.h> |
| #include <time.h> |
| |
| #include <private/android_filesystem_config.h> |
| #include <cutils/partition_utils.h> |
| #include <cutils/properties.h> |
| |
| #include "fs_mgr_priv.h" |
| |
| #define KEY_LOC_PROP "ro.crypto.keyfile.userdata" |
| #define KEY_IN_FOOTER "footer" |
| |
| #define E2FSCK_BIN "/system/bin/e2fsck" |
| |
| struct flag_list { |
| const char *name; |
| unsigned flag; |
| }; |
| |
| static struct flag_list mount_flags[] = { |
| { "noatime", MS_NOATIME }, |
| { "noexec", MS_NOEXEC }, |
| { "nosuid", MS_NOSUID }, |
| { "nodev", MS_NODEV }, |
| { "nodiratime", MS_NODIRATIME }, |
| { "ro", MS_RDONLY }, |
| { "rw", 0 }, |
| { "remount", MS_REMOUNT }, |
| { "defaults", 0 }, |
| { 0, 0 }, |
| }; |
| |
| static struct flag_list fs_mgr_flags[] = { |
| { "wait", MF_WAIT }, |
| { "check", MF_CHECK }, |
| { "encryptable=",MF_CRYPT }, |
| { "defaults", 0 }, |
| { 0, 0 }, |
| }; |
| |
| /* |
| * gettime() - returns the time in seconds of the system's monotonic clock or |
| * zero on error. |
| */ |
| static time_t gettime(void) |
| { |
| struct timespec ts; |
| int ret; |
| |
| ret = clock_gettime(CLOCK_MONOTONIC, &ts); |
| if (ret < 0) { |
| ERROR("clock_gettime(CLOCK_MONOTONIC) failed: %s\n", strerror(errno)); |
| return 0; |
| } |
| |
| return ts.tv_sec; |
| } |
| |
| static int wait_for_file(const char *filename, int timeout) |
| { |
| struct stat info; |
| time_t timeout_time = gettime() + timeout; |
| int ret = -1; |
| |
| while (gettime() < timeout_time && ((ret = stat(filename, &info)) < 0)) |
| usleep(10000); |
| |
| return ret; |
| } |
| |
| static int parse_flags(char *flags, struct flag_list *fl, char **key_loc, |
| char *fs_options, int fs_options_len) |
| { |
| int f = 0; |
| int i; |
| char *p; |
| char *savep; |
| |
| /* initialize key_loc to null, if we find an MF_CRYPT flag, |
| * then we'll set key_loc to the proper value */ |
| if (key_loc) { |
| *key_loc = NULL; |
| } |
| /* initialize fs_options to the null string */ |
| if (fs_options && (fs_options_len > 0)) { |
| fs_options[0] = '\0'; |
| } |
| |
| p = strtok_r(flags, ",", &savep); |
| while (p) { |
| /* Look for the flag "p" in the flag list "fl" |
| * If not found, the loop exits with fl[i].name being null. |
| */ |
| for (i = 0; fl[i].name; i++) { |
| if (!strncmp(p, fl[i].name, strlen(fl[i].name))) { |
| f |= fl[i].flag; |
| if ((fl[i].flag == MF_CRYPT) && key_loc) { |
| /* The encryptable flag is followed by an = and the |
| * location of the keys. Get it and return it. |
| */ |
| *key_loc = strdup(strchr(p, '=') + 1); |
| } |
| break; |
| } |
| } |
| |
| if (!fl[i].name) { |
| if (fs_options) { |
| /* It's not a known flag, so it must be a filesystem specific |
| * option. Add it to fs_options if it was passed in. |
| */ |
| strlcat(fs_options, p, fs_options_len); |
| strlcat(fs_options, ",", fs_options_len); |
| } else { |
| /* fs_options was not passed in, so if the flag is unknown |
| * it's an error. |
| */ |
| ERROR("Warning: unknown flag %s\n", p); |
| } |
| } |
| p = strtok_r(NULL, ",", &savep); |
| } |
| |
| out: |
| if (fs_options && fs_options[0]) { |
| /* remove the last trailing comma from the list of options */ |
| fs_options[strlen(fs_options) - 1] = '\0'; |
| } |
| |
| return f; |
| } |
| |
| /* Read a line of text till the next newline character. |
| * If no newline is found before the buffer is full, continue reading till a new line is seen, |
| * then return an empty buffer. This effectively ignores lines that are too long. |
| * On EOF, return null. |
| */ |
| static char *getline(char *buf, int size, FILE *file) |
| { |
| int cnt = 0; |
| int eof = 0; |
| int eol = 0; |
| int c; |
| |
| if (size < 1) { |
| return NULL; |
| } |
| |
| while (cnt < (size - 1)) { |
| c = getc(file); |
| if (c == EOF) { |
| eof = 1; |
| break; |
| } |
| |
| *(buf + cnt) = c; |
| cnt++; |
| |
| if (c == '\n') { |
| eol = 1; |
| break; |
| } |
| } |
| |
| /* Null terminate what we've read */ |
| *(buf + cnt) = '\0'; |
| |
| if (eof) { |
| if (cnt) { |
| return buf; |
| } else { |
| return NULL; |
| } |
| } else if (eol) { |
| return buf; |
| } else { |
| /* The line is too long. Read till a newline or EOF. |
| * If EOF, return null, if newline, return an empty buffer. |
| */ |
| while(1) { |
| c = getc(file); |
| if (c == EOF) { |
| return NULL; |
| } else if (c == '\n') { |
| *buf = '\0'; |
| return buf; |
| } |
| } |
| } |
| } |
| |
| static struct fstab_rec *read_fstab(char *fstab_path) |
| { |
| FILE *fstab_file; |
| int cnt, entries; |
| int len; |
| char line[256]; |
| const char *delim = " \t"; |
| char *save_ptr, *p; |
| struct fstab_rec *fstab; |
| char *key_loc; |
| #define FS_OPTIONS_LEN 1024 |
| char tmp_fs_options[FS_OPTIONS_LEN]; |
| |
| fstab_file = fopen(fstab_path, "r"); |
| if (!fstab_file) { |
| ERROR("Cannot open file %s\n", fstab_path); |
| return 0; |
| } |
| |
| entries = 0; |
| while (getline(line, sizeof(line), fstab_file)) { |
| /* if the last character is a newline, shorten the string by 1 byte */ |
| len = strlen(line); |
| if (line[len - 1] == '\n') { |
| line[len - 1] = '\0'; |
| } |
| /* Skip any leading whitespace */ |
| p = line; |
| while (isspace(*p)) { |
| p++; |
| } |
| /* ignore comments or empty lines */ |
| if (*p == '#' || *p == '\0') |
| continue; |
| entries++; |
| } |
| |
| if (!entries) { |
| ERROR("No entries found in fstab\n"); |
| return 0; |
| } |
| |
| fstab = calloc(entries + 1, sizeof(struct fstab_rec)); |
| |
| fseek(fstab_file, 0, SEEK_SET); |
| |
| cnt = 0; |
| while (getline(line, sizeof(line), fstab_file)) { |
| /* if the last character is a newline, shorten the string by 1 byte */ |
| len = strlen(line); |
| if (line[len - 1] == '\n') { |
| line[len - 1] = '\0'; |
| } |
| |
| /* Skip any leading whitespace */ |
| p = line; |
| while (isspace(*p)) { |
| p++; |
| } |
| /* ignore comments or empty lines */ |
| if (*p == '#' || *p == '\0') |
| continue; |
| |
| /* If a non-comment entry is greater than the size we allocated, give an |
| * error and quit. This can happen in the unlikely case the file changes |
| * between the two reads. |
| */ |
| if (cnt >= entries) { |
| ERROR("Tried to process more entries than counted\n"); |
| break; |
| } |
| |
| if (!(p = strtok_r(line, delim, &save_ptr))) { |
| ERROR("Error parsing mount source\n"); |
| return 0; |
| } |
| fstab[cnt].blk_dev = strdup(p); |
| |
| if (!(p = strtok_r(NULL, delim, &save_ptr))) { |
| ERROR("Error parsing mnt_point\n"); |
| return 0; |
| } |
| fstab[cnt].mnt_point = strdup(p); |
| |
| if (!(p = strtok_r(NULL, delim, &save_ptr))) { |
| ERROR("Error parsing fs_type\n"); |
| return 0; |
| } |
| fstab[cnt].type = strdup(p); |
| |
| if (!(p = strtok_r(NULL, delim, &save_ptr))) { |
| ERROR("Error parsing mount_flags\n"); |
| return 0; |
| } |
| tmp_fs_options[0] = '\0'; |
| fstab[cnt].flags = parse_flags(p, mount_flags, 0, tmp_fs_options, FS_OPTIONS_LEN); |
| |
| /* fs_options are optional */ |
| if (tmp_fs_options[0]) { |
| fstab[cnt].fs_options = strdup(tmp_fs_options); |
| } else { |
| fstab[cnt].fs_options = NULL; |
| } |
| |
| if (!(p = strtok_r(NULL, delim, &save_ptr))) { |
| ERROR("Error parsing fs_mgr_options\n"); |
| return 0; |
| } |
| fstab[cnt].fs_mgr_flags = parse_flags(p, fs_mgr_flags, &key_loc, 0, 0); |
| fstab[cnt].key_loc = key_loc; |
| |
| cnt++; |
| } |
| fclose(fstab_file); |
| |
| return fstab; |
| } |
| |
| static void free_fstab(struct fstab_rec *fstab) |
| { |
| int i = 0; |
| |
| while (fstab[i].blk_dev) { |
| /* Free the pointers return by strdup(3) */ |
| free(fstab[i].blk_dev); |
| free(fstab[i].mnt_point); |
| free(fstab[i].type); |
| free(fstab[i].fs_options); |
| free(fstab[i].key_loc); |
| |
| i++; |
| } |
| |
| /* Free the actual fstab array created by calloc(3) */ |
| free(fstab); |
| } |
| |
| static void check_fs(char *blk_dev, char *type) |
| { |
| pid_t pid; |
| int status; |
| |
| /* Check for the types of filesystems we know how to check */ |
| if (!strcmp(type, "ext2") || !strcmp(type, "ext3") || !strcmp(type, "ext4")) { |
| INFO("Running %s on %s\n", E2FSCK_BIN, blk_dev); |
| pid = fork(); |
| if (pid > 0) { |
| /* Parent, wait for the child to return */ |
| waitpid(pid, &status, 0); |
| } else if (pid == 0) { |
| /* child, run checker */ |
| execlp(E2FSCK_BIN, E2FSCK_BIN, "-y", blk_dev, (char *)NULL); |
| |
| /* Only gets here on error */ |
| ERROR("Cannot run fs_mgr binary %s\n", E2FSCK_BIN); |
| } else { |
| /* No need to check for error in fork, we can't really handle it now */ |
| ERROR("Fork failed trying to run %s\n", E2FSCK_BIN); |
| } |
| } |
| |
| return; |
| } |
| |
| static void remove_trailing_slashes(char *n) |
| { |
| int len; |
| |
| len = strlen(n) - 1; |
| while ((*(n + len) == '/') && len) { |
| *(n + len) = '\0'; |
| len--; |
| } |
| } |
| |
| static int fs_match(char *in1, char *in2) |
| { |
| char *n1; |
| char *n2; |
| int ret; |
| |
| n1 = strdup(in1); |
| n2 = strdup(in2); |
| |
| remove_trailing_slashes(n1); |
| remove_trailing_slashes(n2); |
| |
| ret = !strcmp(n1, n2); |
| |
| free(n1); |
| free(n2); |
| |
| return ret; |
| } |
| |
| int fs_mgr_mount_all(char *fstab_file) |
| { |
| int i = 0; |
| int encrypted = 0; |
| int ret = -1; |
| int mret; |
| struct fstab_rec *fstab = 0; |
| |
| if (!(fstab = read_fstab(fstab_file))) { |
| return ret; |
| } |
| |
| for (i = 0; fstab[i].blk_dev; i++) { |
| if (fstab[i].fs_mgr_flags & MF_WAIT) { |
| wait_for_file(fstab[i].blk_dev, WAIT_TIMEOUT); |
| } |
| |
| if (fstab[i].fs_mgr_flags & MF_CHECK) { |
| check_fs(fstab[i].blk_dev, fstab[i].type); |
| } |
| |
| mret = mount(fstab[i].blk_dev, fstab[i].mnt_point, fstab[i].type, |
| fstab[i].flags, fstab[i].fs_options); |
| if (!mret) { |
| /* Success! Go get the next one */ |
| continue; |
| } |
| |
| /* mount(2) returned an error, check if it's encrypted and deal with it */ |
| if ((fstab[i].fs_mgr_flags & MF_CRYPT) && !partition_wiped(fstab[i].blk_dev)) { |
| /* Need to mount a tmpfs at this mountpoint for now, and set |
| * properties that vold will query later for decrypting |
| */ |
| if (mount("tmpfs", fstab[i].mnt_point, "tmpfs", |
| MS_NOATIME | MS_NOSUID | MS_NODEV, CRYPTO_TMPFS_OPTIONS) < 0) { |
| ERROR("Cannot mount tmpfs filesystem for encrypted fs at %s\n", |
| fstab[i].mnt_point); |
| goto out; |
| } |
| encrypted = 1; |
| } else { |
| ERROR("Cannot mount filesystem on %s at %s\n", |
| fstab[i].blk_dev, fstab[i].mnt_point); |
| goto out; |
| } |
| } |
| |
| if (encrypted) { |
| ret = 1; |
| } else { |
| ret = 0; |
| } |
| |
| out: |
| free_fstab(fstab); |
| return ret; |
| } |
| |
| /* If tmp_mnt_point is non-null, mount the filesystem there. This is for the |
| * tmp mount we do to check the user password |
| */ |
| int fs_mgr_do_mount(char *fstab_file, char *n_name, char *n_blk_dev, char *tmp_mnt_point) |
| { |
| int i = 0; |
| int ret = -1; |
| struct fstab_rec *fstab = 0; |
| char *m; |
| |
| if (!(fstab = read_fstab(fstab_file))) { |
| return ret; |
| } |
| |
| for (i = 0; fstab[i].blk_dev; i++) { |
| if (!fs_match(fstab[i].mnt_point, n_name)) { |
| continue; |
| } |
| |
| /* We found our match */ |
| /* First check the filesystem if requested */ |
| if (fstab[i].fs_mgr_flags & MF_WAIT) { |
| wait_for_file(fstab[i].blk_dev, WAIT_TIMEOUT); |
| } |
| |
| if (fstab[i].fs_mgr_flags & MF_CHECK) { |
| check_fs(fstab[i].blk_dev, fstab[i].type); |
| } |
| |
| /* Now mount it where requested */ |
| if (tmp_mnt_point) { |
| m = tmp_mnt_point; |
| } else { |
| m = fstab[i].mnt_point; |
| } |
| if (mount(n_blk_dev, m, fstab[i].type, |
| fstab[i].flags, fstab[i].fs_options)) { |
| ERROR("Cannot mount filesystem on %s at %s\n", |
| n_blk_dev, m); |
| goto out; |
| } else { |
| ret = 0; |
| goto out; |
| } |
| } |
| |
| /* We didn't find a match, say so and return an error */ |
| ERROR("Cannot find mount point %s in fstab\n", fstab[i].mnt_point); |
| |
| out: |
| free_fstab(fstab); |
| return ret; |
| } |
| |
| /* |
| * mount a tmpfs filesystem at the given point. |
| * return 0 on success, non-zero on failure. |
| */ |
| int fs_mgr_do_tmpfs_mount(char *n_name) |
| { |
| int ret; |
| |
| ret = mount("tmpfs", n_name, "tmpfs", |
| MS_NOATIME | MS_NOSUID | MS_NODEV, CRYPTO_TMPFS_OPTIONS); |
| if (ret < 0) { |
| ERROR("Cannot mount tmpfs filesystem at %s\n", n_name); |
| return -1; |
| } |
| |
| /* Success */ |
| return 0; |
| } |
| |
| int fs_mgr_unmount_all(char *fstab_file) |
| { |
| int i = 0; |
| int ret = 0; |
| struct fstab_rec *fstab = 0; |
| |
| if (!(fstab = read_fstab(fstab_file))) { |
| return -1; |
| } |
| |
| while (fstab[i].blk_dev) { |
| if (umount(fstab[i].mnt_point)) { |
| ERROR("Cannot unmount filesystem at %s\n", fstab[i].mnt_point); |
| ret = -1; |
| } |
| i++; |
| } |
| |
| free_fstab(fstab); |
| return ret; |
| } |
| /* |
| * key_loc must be at least PROPERTY_VALUE_MAX bytes long |
| * |
| * real_blk_dev must be at least PROPERTY_VALUE_MAX bytes long |
| */ |
| int fs_mgr_get_crypt_info(char *fstab_file, char *key_loc, char *real_blk_dev, int size) |
| { |
| int i = 0; |
| struct fstab_rec *fstab = 0; |
| |
| if (!(fstab = read_fstab(fstab_file))) { |
| return -1; |
| } |
| /* Initialize return values to null strings */ |
| if (key_loc) { |
| *key_loc = '\0'; |
| } |
| if (real_blk_dev) { |
| *real_blk_dev = '\0'; |
| } |
| |
| /* Look for the encryptable partition to find the data */ |
| for (i = 0; fstab[i].blk_dev; i++) { |
| if (!(fstab[i].fs_mgr_flags & MF_CRYPT)) { |
| continue; |
| } |
| |
| /* We found a match */ |
| if (key_loc) { |
| strlcpy(key_loc, fstab[i].key_loc, size); |
| } |
| if (real_blk_dev) { |
| strlcpy(real_blk_dev, fstab[i].blk_dev, size); |
| } |
| break; |
| } |
| |
| free_fstab(fstab); |
| return 0; |
| } |
| |
