| /* |
| * Copyright (C) 2014 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 <ctype.h> |
| #include <errno.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/mount.h> |
| #include <unistd.h> |
| |
| #include "fs_mgr_priv.h" |
| |
| struct fs_mgr_flag_values { |
| char *key_loc; |
| char *verity_loc; |
| long long part_length; |
| char *label; |
| int partnum; |
| int swap_prio; |
| unsigned int zram_size; |
| }; |
| |
| 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 }, |
| { "forceencrypt=",MF_FORCECRYPT }, |
| { "fileencryption",MF_FILEENCRYPTION }, |
| { "nonremovable",MF_NONREMOVABLE }, |
| { "voldmanaged=",MF_VOLDMANAGED}, |
| { "length=", MF_LENGTH }, |
| { "recoveryonly",MF_RECOVERYONLY }, |
| { "swapprio=", MF_SWAPPRIO }, |
| { "zramsize=", MF_ZRAMSIZE }, |
| { "verify", MF_VERIFY }, |
| { "noemulatedsd", MF_NOEMULATEDSD }, |
| { "notrim", MF_NOTRIM }, |
| { "formattable", MF_FORMATTABLE }, |
| { "slotselect", MF_SLOTSELECT }, |
| { "defaults", 0 }, |
| { 0, 0 }, |
| }; |
| |
| static uint64_t calculate_zram_size(unsigned int percentage) |
| { |
| uint64_t total; |
| |
| total = sysconf(_SC_PHYS_PAGES); |
| total *= percentage; |
| total /= 100; |
| |
| total *= sysconf(_SC_PAGESIZE); |
| |
| return total; |
| } |
| |
| 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_VERIFY) && flag_vals) { |
| /* If the verify flag is followed by an = and the |
| * location for the verity state, get it and return it. |
| */ |
| char *start = strchr(p, '='); |
| if (start) { |
| flag_vals->verity_loc = strdup(start + 1); |
| } |
| } else if ((fl[i].flag == MF_FORCECRYPT) && flag_vals) { |
| /* The forceencrypt 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) { |
| int is_percent = !!strrchr(p, '%'); |
| unsigned int val = strtoll(strchr(p, '=') + 1, NULL, 0); |
| if (is_percent) |
| flag_vals->zram_size = calculate_zram_size(val); |
| else |
| flag_vals->zram_size = val; |
| } |
| 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); |
| } |
| |
| 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; |
| } |
| |
| struct fstab *fs_mgr_read_fstab(const char *fstab_path) |
| { |
| FILE *fstab_file; |
| int cnt, entries; |
| ssize_t len; |
| size_t alloc_len = 0; |
| char *line = NULL; |
| const char *delim = " \t"; |
| char *save_ptr, *p; |
| struct fstab *fstab = NULL; |
| 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 ((len = getline(&line, &alloc_len, fstab_file)) != -1) { |
| /* if the last character is a newline, shorten the string by 1 byte */ |
| 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"); |
| goto err; |
| } |
| |
| /* 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 ((len = getline(&line, &alloc_len, fstab_file)) != -1) { |
| /* if the last character is a newline, shorten the string by 1 byte */ |
| 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"); |
| goto err; |
| } |
| fstab->recs[cnt].blk_device = strdup(p); |
| |
| if (!(p = strtok_r(NULL, delim, &save_ptr))) { |
| ERROR("Error parsing mount_point\n"); |
| goto err; |
| } |
| fstab->recs[cnt].mount_point = strdup(p); |
| |
| if (!(p = strtok_r(NULL, delim, &save_ptr))) { |
| ERROR("Error parsing fs_type\n"); |
| goto err; |
| } |
| fstab->recs[cnt].fs_type = strdup(p); |
| |
| if (!(p = strtok_r(NULL, delim, &save_ptr))) { |
| ERROR("Error parsing mount_flags\n"); |
| goto err; |
| } |
| 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"); |
| goto err; |
| } |
| 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].verity_loc = flag_vals.verity_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++; |
| } |
| /* If an A/B partition, modify block device to be the real block device */ |
| if (fs_mgr_update_for_slotselect(fstab) != 0) { |
| ERROR("Error updating for slotselect\n"); |
| goto err; |
| } |
| fclose(fstab_file); |
| free(line); |
| return fstab; |
| |
| err: |
| fclose(fstab_file); |
| free(line); |
| if (fstab) |
| fs_mgr_free_fstab(fstab); |
| return NULL; |
| } |
| |
| 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); |
| } |
| |
| /* Free the fstab_recs array created by calloc(3) */ |
| free(fstab->recs); |
| |
| /* Free the fstab filename */ |
| free(fstab->fstab_filename); |
| |
| /* Free fstab */ |
| free(fstab); |
| } |
| |
| /* 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) |
| { |
| 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; |
| } |
| |
| /* |
| * Returns the 1st matching fstab_rec that follows the start_rec. |
| * start_rec is the result of a previous search or NULL. |
| */ |
| struct fstab_rec *fs_mgr_get_entry_for_mount_point_after(struct fstab_rec *start_rec, struct fstab *fstab, const char *path) |
| { |
| int i; |
| if (!fstab) { |
| return NULL; |
| } |
| |
| if (start_rec) { |
| for (i = 0; i < fstab->num_entries; i++) { |
| if (&fstab->recs[i] == start_rec) { |
| i++; |
| break; |
| } |
| } |
| } else { |
| i = 0; |
| } |
| for (; 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; |
| } |
| |
| /* |
| * Returns the 1st matching mount point. |
| * There might be more. To look for others, use fs_mgr_get_entry_for_mount_point_after() |
| * and give the fstab_rec from the previous search. |
| */ |
| struct fstab_rec *fs_mgr_get_entry_for_mount_point(struct fstab *fstab, const char *path) |
| { |
| return fs_mgr_get_entry_for_mount_point_after(NULL, fstab, path); |
| } |
| |
| int fs_mgr_is_voldmanaged(const struct fstab_rec *fstab) |
| { |
| return fstab->fs_mgr_flags & MF_VOLDMANAGED; |
| } |
| |
| int fs_mgr_is_nonremovable(const struct fstab_rec *fstab) |
| { |
| return fstab->fs_mgr_flags & MF_NONREMOVABLE; |
| } |
| |
| int fs_mgr_is_verified(const struct fstab_rec *fstab) |
| { |
| return fstab->fs_mgr_flags & MF_VERIFY; |
| } |
| |
| int fs_mgr_is_encryptable(const struct fstab_rec *fstab) |
| { |
| return fstab->fs_mgr_flags & (MF_CRYPT | MF_FORCECRYPT); |
| } |
| |
| int fs_mgr_is_file_encrypted(const struct fstab_rec *fstab) |
| { |
| return fstab->fs_mgr_flags & MF_FILEENCRYPTION; |
| } |
| |
| int fs_mgr_is_noemulatedsd(const struct fstab_rec *fstab) |
| { |
| return fstab->fs_mgr_flags & MF_NOEMULATEDSD; |
| } |
| |
| int fs_mgr_is_notrim(struct fstab_rec *fstab) |
| { |
| return fstab->fs_mgr_flags & MF_NOTRIM; |
| } |
| |
| int fs_mgr_is_formattable(struct fstab_rec *fstab) |
| { |
| return fstab->fs_mgr_flags & (MF_FORMATTABLE); |
| } |
| |
| int fs_mgr_is_slotselect(struct fstab_rec *fstab) |
| { |
| return fstab->fs_mgr_flags & MF_SLOTSELECT; |
| } |
