/* * 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. */ #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 <sys/swap.h> /* XXX These need to be obtained from kernel headers. See b/9336527 */ #define SWAP_FLAG_PREFER 0x8000 #define SWAP_FLAG_PRIO_MASK 0x7fff #define SWAP_FLAG_PRIO_SHIFT 0 #define SWAP_FLAG_DISCARD 0x10000 #include <linux/loop.h> #include <private/android_filesystem_config.h> #include <cutils/partition_utils.h> #include <cutils/properties.h> #include <logwrap/logwrap.h> #include "mincrypt/rsa.h" #include "mincrypt/sha.h" #include "mincrypt/sha256.h" #include "fs_mgr_priv.h" #include "fs_mgr_priv_verity.h" #define KEY_LOC_PROP "ro.crypto.keyfile.userdata" #define KEY_IN_FOOTER "footer" #define E2FSCK_BIN "/system/bin/e2fsck" #define MKSWAP_BIN "/system/bin/mkswap" #define FSCK_LOG_FILE "/dev/fscklogs/log" #define ZRAM_CONF_DEV "/sys/block/zram0/disksize" #define ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a))) 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 }, { "bind", MS_BIND }, { "rec", MS_REC }, { "unbindable", MS_UNBINDABLE }, { "private", MS_PRIVATE }, { "slave", MS_SLAVE }, { "shared", MS_SHARED }, { "defaults", 0 }, { 0, 0 }, }; static struct flag_list fs_mgr_flags[] = { { "wait", MF_WAIT }, { "check", MF_CHECK }, { "encryptable=",MF_CRYPT }, { "nonremovable",MF_NONREMOVABLE }, { "voldmanaged=",MF_VOLDMANAGED}, { "length=", MF_LENGTH }, { "recoveryonly",MF_RECOVERYONLY }, { "swapprio=", MF_SWAPPRIO }, { "zramsize=", MF_ZRAMSIZE }, { "verify", MF_VERIFY }, { "noemulatedsd", MF_NOEMULATEDSD }, { "defaults", 0 }, { 0, 0 }, }; struct fs_mgr_flag_values { char *key_loc; long long part_length; char *label; int partnum; int swap_prio; unsigned int zram_size; }; /* * 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, struct fs_mgr_flag_values *flag_vals, char *fs_options, int fs_options_len) { int f = 0; int i; char *p; char *savep; /* initialize flag values. If we find a relevant flag, we'll * update the value */ if (flag_vals) { memset(flag_vals, 0, sizeof(*flag_vals)); flag_vals->partnum = -1; flag_vals->swap_prio = -1; /* negative means it wasn't specified. */ } /* 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) && flag_vals) { /* The encryptable flag is followed by an = and the * location of the keys. Get it and return it. */ flag_vals->key_loc = strdup(strchr(p, '=') + 1); } else if ((fl[i].flag == MF_LENGTH) && flag_vals) { /* The length flag is followed by an = and the * size of the partition. Get it and return it. */ flag_vals->part_length = strtoll(strchr(p, '=') + 1, NULL, 0); } else if ((fl[i].flag == MF_VOLDMANAGED) && flag_vals) { /* The voldmanaged flag is followed by an = and the * label, a colon and the partition number or the * word "auto", e.g. * voldmanaged=sdcard:3 * Get and return them. */ char *label_start; char *label_end; char *part_start; label_start = strchr(p, '=') + 1; label_end = strchr(p, ':'); if (label_end) { flag_vals->label = strndup(label_start, (int) (label_end - label_start)); part_start = strchr(p, ':') + 1; if (!strcmp(part_start, "auto")) { flag_vals->partnum = -1; } else { flag_vals->partnum = strtol(part_start, NULL, 0); } } else { ERROR("Warning: voldmanaged= flag malformed\n"); } } else if ((fl[i].flag == MF_SWAPPRIO) && flag_vals) { flag_vals->swap_prio = strtoll(strchr(p, '=') + 1, NULL, 0); } else if ((fl[i].flag == MF_ZRAMSIZE) && flag_vals) { flag_vals->zram_size = strtoll(strchr(p, '=') + 1, NULL, 0); } 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 *fs_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; } } } } struct fstab *fs_mgr_read_fstab(const char *fstab_path) { FILE *fstab_file; int cnt, entries; int len; char line[256]; const char *delim = " \t"; char *save_ptr, *p; struct fstab *fstab; struct fstab_rec *recs; struct fs_mgr_flag_values flag_vals; #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 (fs_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; } /* Allocate and init the fstab structure */ fstab = calloc(1, sizeof(struct fstab)); fstab->num_entries = entries; fstab->fstab_filename = strdup(fstab_path); fstab->recs = calloc(fstab->num_entries, sizeof(struct fstab_rec)); fseek(fstab_file, 0, SEEK_SET); cnt = 0; while (fs_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->recs[cnt].blk_device = strdup(p); if (!(p = strtok_r(NULL, delim, &save_ptr))) { ERROR("Error parsing mount_point\n"); return 0; } fstab->recs[cnt].mount_point = strdup(p); if (!(p = strtok_r(NULL, delim, &save_ptr))) { ERROR("Error parsing fs_type\n"); return 0; } fstab->recs[cnt].fs_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->recs[cnt].flags = parse_flags(p, mount_flags, NULL, tmp_fs_options, FS_OPTIONS_LEN); /* fs_options are optional */ if (tmp_fs_options[0]) { fstab->recs[cnt].fs_options = strdup(tmp_fs_options); } else { fstab->recs[cnt].fs_options = NULL; } if (!(p = strtok_r(NULL, delim, &save_ptr))) { ERROR("Error parsing fs_mgr_options\n"); return 0; } fstab->recs[cnt].fs_mgr_flags = parse_flags(p, fs_mgr_flags, &flag_vals, NULL, 0); fstab->recs[cnt].key_loc = flag_vals.key_loc; fstab->recs[cnt].length = flag_vals.part_length; fstab->recs[cnt].label = flag_vals.label; fstab->recs[cnt].partnum = flag_vals.partnum; fstab->recs[cnt].swap_prio = flag_vals.swap_prio; fstab->recs[cnt].zram_size = flag_vals.zram_size; cnt++; } fclose(fstab_file); return fstab; } void fs_mgr_free_fstab(struct fstab *fstab) { int i; if (!fstab) { return; } for (i = 0; i < fstab->num_entries; i++) { /* Free the pointers return by strdup(3) */ free(fstab->recs[i].blk_device); free(fstab->recs[i].mount_point); free(fstab->recs[i].fs_type); free(fstab->recs[i].fs_options); free(fstab->recs[i].key_loc); free(fstab->recs[i].label); i++; } /* Free the fstab_recs array created by calloc(3) */ free(fstab->recs); /* Free the fstab filename */ free(fstab->fstab_filename); /* Free fstab */ free(fstab); } static void check_fs(char *blk_device, char *fs_type, char *target) { int status; int ret; long tmpmnt_flags = MS_NOATIME | MS_NOEXEC | MS_NOSUID; char *tmpmnt_opts = "nomblk_io_submit,errors=remount-ro"; char *e2fsck_argv[] = { E2FSCK_BIN, "-y", blk_device }; /* Check for the types of filesystems we know how to check */ if (!strcmp(fs_type, "ext2") || !strcmp(fs_type, "ext3") || !strcmp(fs_type, "ext4")) { /* * First try to mount and unmount the filesystem. We do this because * the kernel is more efficient than e2fsck in running the journal and * processing orphaned inodes, and on at least one device with a * performance issue in the emmc firmware, it can take e2fsck 2.5 minutes * to do what the kernel does in about a second. * * After mounting and unmounting the filesystem, run e2fsck, and if an * error is recorded in the filesystem superblock, e2fsck will do a full * check. Otherwise, it does nothing. If the kernel cannot mount the * filesytsem due to an error, e2fsck is still run to do a full check * fix the filesystem. */ ret = mount(blk_device, target, fs_type, tmpmnt_flags, tmpmnt_opts); if (!ret) { umount(target); } INFO("Running %s on %s\n", E2FSCK_BIN, blk_device); ret = android_fork_execvp_ext(ARRAY_SIZE(e2fsck_argv), e2fsck_argv, &status, true, LOG_KLOG | LOG_FILE, true, FSCK_LOG_FILE); if (ret < 0) { /* No need to check for error in fork, we can't really handle it now */ ERROR("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--; } } /* * Mark the given block device as read-only, using the BLKROSET ioctl. * Return 0 on success, and -1 on error. */ static void fs_set_blk_ro(const char *blockdev) { int fd; int ON = 1; fd = open(blockdev, O_RDONLY); if (fd < 0) { // should never happen return; } ioctl(fd, BLKROSET, &ON); close(fd); } /* * __mount(): wrapper around the mount() system call which also * sets the underlying block device to read-only if the mount is read-only. * See "man 2 mount" for return values. */ static int __mount(const char *source, const char *target, const char *filesystemtype, unsigned long mountflags, const void *data) { int ret = mount(source, target, filesystemtype, mountflags, data); if ((ret == 0) && (mountflags & MS_RDONLY) != 0) { fs_set_blk_ro(source); } return ret; } 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(struct fstab *fstab) { int i = 0; int encrypted = 0; int ret = -1; int mret; if (!fstab) { return ret; } for (i = 0; i < fstab->num_entries; i++) { /* Don't mount entries that are managed by vold */ if (fstab->recs[i].fs_mgr_flags & (MF_VOLDMANAGED | MF_RECOVERYONLY)) { continue; } /* Skip swap and raw partition entries such as boot, recovery, etc */ if (!strcmp(fstab->recs[i].fs_type, "swap") || !strcmp(fstab->recs[i].fs_type, "emmc") || !strcmp(fstab->recs[i].fs_type, "mtd")) { continue; } if (fstab->recs[i].fs_mgr_flags & MF_WAIT) { wait_for_file(fstab->recs[i].blk_device, WAIT_TIMEOUT); } if (fstab->recs[i].fs_mgr_flags & MF_CHECK) { check_fs(fstab->recs[i].blk_device, fstab->recs[i].fs_type, fstab->recs[i].mount_point); } if (fstab->recs[i].fs_mgr_flags & MF_VERIFY) { if (fs_mgr_setup_verity(&fstab->recs[i]) < 0) { ERROR("Could not set up verified partition, skipping!"); continue; } } mret = __mount(fstab->recs[i].blk_device, fstab->recs[i].mount_point, fstab->recs[i].fs_type, fstab->recs[i].flags, fstab->recs[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->recs[i].fs_mgr_flags & MF_CRYPT) && !partition_wiped(fstab->recs[i].blk_device)) { /* Need to mount a tmpfs at this mountpoint for now, and set * properties that vold will query later for decrypting */ if (mount("tmpfs", fstab->recs[i].mount_point, "tmpfs", MS_NOATIME | MS_NOSUID | MS_NODEV, CRYPTO_TMPFS_OPTIONS) < 0) { ERROR("Cannot mount tmpfs filesystem for encrypted fs at %s\n", fstab->recs[i].mount_point); goto out; } encrypted = 1; } else { ERROR("Cannot mount filesystem on %s at %s\n", fstab->recs[i].blk_device, fstab->recs[i].mount_point); goto out; } } if (encrypted) { ret = 1; } else { ret = 0; } out: return ret; } /* If tmp_mount_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(struct fstab *fstab, char *n_name, char *n_blk_device, char *tmp_mount_point) { int i = 0; int ret = -1; char *m; if (!fstab) { return ret; } for (i = 0; i < fstab->num_entries; i++) { if (!fs_match(fstab->recs[i].mount_point, n_name)) { continue; } /* We found our match */ /* If this swap or a raw partition, report an error */ if (!strcmp(fstab->recs[i].fs_type, "swap") || !strcmp(fstab->recs[i].fs_type, "emmc") || !strcmp(fstab->recs[i].fs_type, "mtd")) { ERROR("Cannot mount filesystem of type %s on %s\n", fstab->recs[i].fs_type, n_blk_device); goto out; } /* First check the filesystem if requested */ if (fstab->recs[i].fs_mgr_flags & MF_WAIT) { wait_for_file(n_blk_device, WAIT_TIMEOUT); } if (fstab->recs[i].fs_mgr_flags & MF_CHECK) { check_fs(n_blk_device, fstab->recs[i].fs_type, fstab->recs[i].mount_point); } if (fstab->recs[i].fs_mgr_flags & MF_VERIFY) { if (fs_mgr_setup_verity(&fstab->recs[i]) < 0) { ERROR("Could not set up verified partition, skipping!"); continue; } } /* Now mount it where requested */ if (tmp_mount_point) { m = tmp_mount_point; } else { m = fstab->recs[i].mount_point; } if (__mount(n_blk_device, m, fstab->recs[i].fs_type, fstab->recs[i].flags, fstab->recs[i].fs_options)) { ERROR("Cannot mount filesystem on %s at %s\n", n_blk_device, 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->recs[i].mount_point); out: 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(struct fstab *fstab) { int i = 0; int ret = 0; if (!fstab) { return -1; } while (fstab->recs[i].blk_device) { if (umount(fstab->recs[i].mount_point)) { ERROR("Cannot unmount filesystem at %s\n", fstab->recs[i].mount_point); ret = -1; } i++; } return ret; } /* This must be called after mount_all, because the mkswap command needs to be * available. */ int fs_mgr_swapon_all(struct fstab *fstab) { int i = 0; int flags = 0; int err = 0; int ret = 0; int status; char *mkswap_argv[2] = { MKSWAP_BIN, NULL }; if (!fstab) { return -1; } for (i = 0; i < fstab->num_entries; i++) { /* Skip non-swap entries */ if (strcmp(fstab->recs[i].fs_type, "swap")) { continue; } if (fstab->recs[i].zram_size > 0) { /* A zram_size was specified, so we need to configure the * device. There is no point in having multiple zram devices * on a system (all the memory comes from the same pool) so * we can assume the device number is 0. */ FILE *zram_fp; zram_fp = fopen(ZRAM_CONF_DEV, "r+"); if (zram_fp == NULL) { ERROR("Unable to open zram conf device " ZRAM_CONF_DEV); ret = -1; continue; } fprintf(zram_fp, "%d\n", fstab->recs[i].zram_size); fclose(zram_fp); } if (fstab->recs[i].fs_mgr_flags & MF_WAIT) { wait_for_file(fstab->recs[i].blk_device, WAIT_TIMEOUT); } /* Initialize the swap area */ mkswap_argv[1] = fstab->recs[i].blk_device; err = android_fork_execvp_ext(ARRAY_SIZE(mkswap_argv), mkswap_argv, &status, true, LOG_KLOG, false, NULL); if (err) { ERROR("mkswap failed for %s\n", fstab->recs[i].blk_device); ret = -1; continue; } /* If -1, then no priority was specified in fstab, so don't set * SWAP_FLAG_PREFER or encode the priority */ if (fstab->recs[i].swap_prio >= 0) { flags = (fstab->recs[i].swap_prio << SWAP_FLAG_PRIO_SHIFT) & SWAP_FLAG_PRIO_MASK; flags |= SWAP_FLAG_PREFER; } else { flags = 0; } err = swapon(fstab->recs[i].blk_device, flags); if (err) { ERROR("swapon failed for %s\n", fstab->recs[i].blk_device); ret = -1; } } return ret; } /* * key_loc must be at least PROPERTY_VALUE_MAX bytes long * * real_blk_device must be at least PROPERTY_VALUE_MAX bytes long */ int fs_mgr_get_crypt_info(struct fstab *fstab, char *key_loc, char *real_blk_device, int size) { int i = 0; if (!fstab) { return -1; } /* Initialize return values to null strings */ if (key_loc) { *key_loc = '\0'; } if (real_blk_device) { *real_blk_device = '\0'; } /* Look for the encryptable partition to find the data */ for (i = 0; i < fstab->num_entries; i++) { /* Don't deal with vold managed enryptable partitions here */ if (fstab->recs[i].fs_mgr_flags & MF_VOLDMANAGED) { continue; } if (!(fstab->recs[i].fs_mgr_flags & MF_CRYPT)) { continue; } /* We found a match */ if (key_loc) { strlcpy(key_loc, fstab->recs[i].key_loc, size); } if (real_blk_device) { strlcpy(real_blk_device, fstab->recs[i].blk_device, size); } break; } return 0; } /* Add an entry to the fstab, and return 0 on success or -1 on error */ int fs_mgr_add_entry(struct fstab *fstab, const char *mount_point, const char *fs_type, const char *blk_device, long long length) { struct fstab_rec *new_fstab_recs; int n = fstab->num_entries; new_fstab_recs = (struct fstab_rec *) realloc(fstab->recs, sizeof(struct fstab_rec) * (n + 1)); if (!new_fstab_recs) { return -1; } /* A new entry was added, so initialize it */ memset(&new_fstab_recs[n], 0, sizeof(struct fstab_rec)); new_fstab_recs[n].mount_point = strdup(mount_point); new_fstab_recs[n].fs_type = strdup(fs_type); new_fstab_recs[n].blk_device = strdup(blk_device); new_fstab_recs[n].length = 0; /* Update the fstab struct */ fstab->recs = new_fstab_recs; fstab->num_entries++; return 0; } struct fstab_rec *fs_mgr_get_entry_for_mount_point(struct fstab *fstab, const char *path) { int i; if (!fstab) { return NULL; } for (i = 0; i < fstab->num_entries; i++) { int len = strlen(fstab->recs[i].mount_point); if (strncmp(path, fstab->recs[i].mount_point, len) == 0 && (path[len] == '\0' || path[len] == '/')) { return &fstab->recs[i]; } } return NULL; } int fs_mgr_is_voldmanaged(struct fstab_rec *fstab) { return fstab->fs_mgr_flags & MF_VOLDMANAGED; } int fs_mgr_is_nonremovable(struct fstab_rec *fstab) { return fstab->fs_mgr_flags & MF_NONREMOVABLE; } int fs_mgr_is_encryptable(struct fstab_rec *fstab) { return fstab->fs_mgr_flags & MF_CRYPT; } int fs_mgr_is_noemulatedsd(struct fstab_rec *fstab) { return fstab->fs_mgr_flags & MF_NOEMULATEDSD; }