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-rw-r--r--contrib/android/e2fsdroid.c377
1 files changed, 377 insertions, 0 deletions
diff --git a/contrib/android/e2fsdroid.c b/contrib/android/e2fsdroid.c
new file mode 100644
index 0000000..6e51414
--- /dev/null
+++ b/contrib/android/e2fsdroid.c
@@ -0,0 +1,377 @@
+#define _GNU_SOURCE
+
+#include "config.h"
+#include <stdio.h>
+#include <getopt.h>
+#include <string.h>
+#include <unistd.h>
+#include <limits.h>
+
+#include "perms.h"
+#include "base_fs.h"
+#include "block_list.h"
+#include "basefs_allocator.h"
+#include "create_inode.h"
+
+#ifndef UID_GID_MAP_MAX_EXTENTS
+/*
+ * The value is defined in linux/user_namspace.h.
+ * The value is (arbitrarily) 5 in 4.14 and earlier, or 340 in 4.15 and later.
+ * Here, the bigger value is taken. See also man user_namespace(7).
+ */
+#define UID_GID_MAP_MAX_EXTENTS 340
+#endif
+
+static char *prog_name = "e2fsdroid";
+static char *in_file;
+static char *block_list;
+static char *basefs_out;
+static char *basefs_in;
+static char *mountpoint = "";
+static time_t fixed_time = -1;
+static char *fs_config_file;
+static struct selinux_opt seopt_file[8];
+static int max_nr_opt = (int)sizeof(seopt_file) / sizeof(seopt_file[0]);
+static char *product_out;
+static char *src_dir;
+static int android_configure;
+static int android_sparse_file = 1;
+
+static void usage(int ret)
+{
+ fprintf(stderr, "%s [-B block_list] [-D basefs_out] [-T timestamp]\n"
+ "\t[-C fs_config] [-S file_contexts] [-p product_out]\n"
+ "\t[-a mountpoint] [-d basefs_in] [-f src_dir] [-e] [-s]\n"
+ "\t[-u uid-mapping] [-g gid-mapping] image\n",
+ prog_name);
+ exit(ret);
+}
+
+static char *absolute_path(const char *file)
+{
+ char *ret;
+ char cwd[PATH_MAX];
+
+ if (file[0] != '/') {
+ if (getcwd(cwd, PATH_MAX) == NULL) {
+ fprintf(stderr, "Failed to getcwd\n");
+ exit(EXIT_FAILURE);
+ }
+ ret = malloc(strlen(cwd) + 1 + strlen(file) + 1);
+ if (ret)
+ sprintf(ret, "%s/%s", cwd, file);
+ } else
+ ret = strdup(file);
+ return ret;
+}
+
+static int parse_ugid_map_entry(char* line, struct ugid_map_entry* result)
+{
+ char *token, *token_saveptr;
+ size_t num_tokens;
+ unsigned int *parsed[] = {&result->child_id,
+ &result->parent_id,
+ &result->length};
+ for (token = strtok_r(line, " ", &token_saveptr), num_tokens = 0;
+ token && num_tokens < 3;
+ token = strtok_r(NULL, " ", &token_saveptr), ++num_tokens) {
+ char* endptr = NULL;
+ unsigned long t = strtoul(token, &endptr, 10);
+ if ((t == ULONG_MAX && errno) || (t > UINT_MAX) || *endptr) {
+ fprintf(stderr, "Malformed u/gid mapping line\n");
+ return 0;
+ }
+ *parsed[num_tokens] = (unsigned int) t;
+ }
+ if (num_tokens < 3 || strtok_r(NULL, " ", &token_saveptr) != NULL) {
+ fprintf(stderr, "Malformed u/gid mapping line\n");
+ return 0;
+ }
+ if (result->child_id + result->length < result->child_id ||
+ result->parent_id + result->length < result->parent_id) {
+ fprintf(stderr, "u/gid mapping overflow\n");
+ return 0;
+ }
+ return 1;
+}
+
+/*
+ * Returns 1 if [begin1, begin1+length1) and [begin2, begin2+length2) have
+ * overlapping range. Otherwise 0.
+ */
+static int is_overlapping(unsigned int begin1, unsigned int length1,
+ unsigned int begin2, unsigned int length2)
+{
+ unsigned int end1 = begin1 + length1;
+ unsigned int end2 = begin2 + length2;
+ return !(end1 <= begin2 || end2 <= begin1);
+}
+
+/*
+ * Verifies if the given mapping works.
+ * - Checks if the number of entries is less than or equals to
+ * UID_GID_MAP_MAX_EXTENTS.
+ * - Checks if there is no overlapped ranges.
+ * Returns 1 if valid, otherwise 0.
+ */
+static int is_valid_ugid_map(const struct ugid_map* mapping)
+{
+ size_t i, j;
+
+ if (mapping->size > UID_GID_MAP_MAX_EXTENTS) {
+ fprintf(stderr, "too many u/gid mapping entries\n");
+ return 0;
+ }
+
+ for (i = 0; i < mapping->size; ++i) {
+ const struct ugid_map_entry *entry1 = &mapping->entries[i];
+ for (j = i + 1; j < mapping->size; ++j) {
+ const struct ugid_map_entry *entry2 =
+ &mapping->entries[j];
+ if (is_overlapping(entry1->child_id, entry1->length,
+ entry2->child_id, entry2->length)) {
+ fprintf(stderr,
+ "Overlapping child u/gid: [%d %d %d],"
+ " [%d %d %d]\n",
+ entry1->child_id, entry1->parent_id,
+ entry1->length, entry2->child_id,
+ entry2->parent_id, entry2->length);
+ return 0;
+ }
+ if (is_overlapping(entry1->parent_id, entry1->length,
+ entry2->parent_id, entry2->length)) {
+ fprintf(stderr,
+ "Overlapping parent u/gid: [%d %d %d],"
+ " [%d %d %d]\n",
+ entry1->child_id, entry1->parent_id,
+ entry1->length, entry2->child_id,
+ entry2->parent_id, entry2->length);
+ return 0;
+ }
+ }
+ }
+ return 1;
+}
+
+/*
+ * Parses the UID/GID mapping argument. The argument could be a multi-line
+ * string (separated by '\n', no trailing '\n' is allowed). Each line must
+ * contain exact three integer tokens; the first token is |child_id|,
+ * the second is |parent_id|, and the last is |length| of the mapping range.
+ * See also user_namespace(7) man page.
+ * On success, the parsed entries are stored in |result|, and it returns 1.
+ * Otherwise, returns 0.
+ */
+static int parse_ugid_map(char* arg, struct ugid_map* result)
+{
+ int i;
+ char *line, *line_saveptr;
+ size_t current_index;
+
+ /* Count the number of lines. */
+ result->size = 1;
+ for (i = 0; arg[i]; ++i) {
+ if (arg[i] == '\n')
+ ++result->size;
+ }
+
+ /* Allocate memory for entries. */
+ result->entries = malloc(sizeof(struct ugid_map_entry) * result->size);
+ if (!result->entries) {
+ result->size = 0;
+ return 0;
+ }
+
+ /* Parse each line */
+ for (line = strtok_r(arg, "\n", &line_saveptr), current_index = 0;
+ line;
+ line = strtok_r(NULL, "\n", &line_saveptr), ++current_index) {
+ if (!parse_ugid_map_entry(
+ line, &result->entries[current_index])) {
+ return 0;
+ }
+ }
+
+ return is_valid_ugid_map(result);
+}
+
+int main(int argc, char *argv[])
+{
+ int c;
+ char *p;
+ int flags = EXT2_FLAG_RW;
+ errcode_t retval;
+ io_manager io_mgr;
+ ext2_filsys fs = NULL;
+ struct fs_ops_callbacks fs_callbacks = { NULL, NULL };
+ char *token;
+ int nr_opt = 0;
+ ext2_ino_t inodes_count;
+ ext2_ino_t free_inodes_count;
+ blk64_t blocks_count;
+ blk64_t free_blocks_count;
+ struct ugid_map uid_map = { 0, NULL }, gid_map = { 0, NULL };
+
+ add_error_table(&et_ext2_error_table);
+
+ while ((c = getopt (argc, argv, "T:C:S:p:a:D:d:B:f:esu:g:")) != EOF) {
+ switch (c) {
+ case 'T':
+ fixed_time = strtoul(optarg, &p, 0);
+ android_configure = 1;
+ break;
+ case 'C':
+ fs_config_file = absolute_path(optarg);
+ android_configure = 1;
+ break;
+ case 'S':
+ token = strtok(optarg, ",");
+ while (token) {
+ if (nr_opt == max_nr_opt) {
+ fprintf(stderr, "Expected at most %d selinux opts\n",
+ max_nr_opt);
+ exit(EXIT_FAILURE);
+ }
+ seopt_file[nr_opt].type = SELABEL_OPT_PATH;
+ seopt_file[nr_opt].value = absolute_path(token);
+ nr_opt++;
+ token = strtok(NULL, ",");
+ }
+ android_configure = 1;
+ break;
+ case 'p':
+ product_out = absolute_path(optarg);
+ android_configure = 1;
+ break;
+ case 'a':
+ mountpoint = strdup(optarg);
+ break;
+ case 'D':
+ basefs_out = absolute_path(optarg);
+ break;
+ case 'd':
+ basefs_in = absolute_path(optarg);
+ break;
+ case 'B':
+ block_list = absolute_path(optarg);
+ break;
+ case 'f':
+ src_dir = absolute_path(optarg);
+ break;
+ case 'e':
+ android_sparse_file = 0;
+ break;
+ case 's':
+ flags |= EXT2_FLAG_SHARE_DUP;
+ break;
+ case 'u':
+ if (!parse_ugid_map(optarg, &uid_map))
+ exit(EXIT_FAILURE);
+ android_configure = 1;
+ break;
+ case 'g':
+ if (!parse_ugid_map(optarg, &gid_map))
+ exit(EXIT_FAILURE);
+ android_configure = 1;
+ break;
+ default:
+ usage(EXIT_FAILURE);
+ }
+ }
+ if (optind >= argc) {
+ fprintf(stderr, "Expected filename after options\n");
+ exit(EXIT_FAILURE);
+ }
+
+ if (android_sparse_file) {
+ io_mgr = sparse_io_manager;
+ if (asprintf(&in_file, "(%s)", argv[optind]) == -1) {
+ fprintf(stderr, "Failed to allocate file name\n");
+ exit(EXIT_FAILURE);
+ }
+ } else {
+ io_mgr = unix_io_manager;
+ in_file = strdup(argv[optind]);
+ }
+ retval = ext2fs_open(in_file, flags, 0, 0, io_mgr, &fs);
+ if (retval) {
+ com_err(prog_name, retval, "while opening file %s\n", in_file);
+ return retval;
+ }
+
+ if (src_dir) {
+ ext2fs_read_bitmaps(fs);
+ if (basefs_in) {
+ retval = base_fs_alloc_load(fs, basefs_in, mountpoint,
+ src_dir);
+ if (retval) {
+ com_err(prog_name, retval, "%s",
+ "while reading base_fs file");
+ exit(1);
+ }
+ fs_callbacks.create_new_inode =
+ base_fs_alloc_set_target;
+ fs_callbacks.end_create_new_inode =
+ base_fs_alloc_unset_target;
+ }
+ retval = populate_fs2(fs, EXT2_ROOT_INO, src_dir,
+ EXT2_ROOT_INO, &fs_callbacks);
+ if (retval) {
+ com_err(prog_name, retval, "%s",
+ "while populating file system");
+ exit(1);
+ }
+ if (basefs_in)
+ base_fs_alloc_cleanup(fs);
+ }
+
+ if (android_configure) {
+ retval = android_configure_fs(
+ fs, src_dir, product_out, mountpoint, seopt_file,
+ nr_opt, fs_config_file, fixed_time, &uid_map, &gid_map);
+ if (retval) {
+ com_err(prog_name, retval, "%s",
+ "while configuring the file system");
+ exit(1);
+ }
+ }
+
+ if (block_list) {
+ retval = fsmap_iter_filsys(fs, &block_list_format, block_list,
+ mountpoint);
+ if (retval) {
+ com_err(prog_name, retval, "%s",
+ "while creating the block_list");
+ exit(1);
+ }
+ }
+
+ if (basefs_out) {
+ retval = fsmap_iter_filsys(fs, &base_fs_format,
+ basefs_out, mountpoint);
+ if (retval) {
+ com_err(prog_name, retval, "%s",
+ "while creating the basefs file");
+ exit(1);
+ }
+ }
+
+ inodes_count = fs->super->s_inodes_count;
+ free_inodes_count = fs->super->s_free_inodes_count;
+ blocks_count = ext2fs_blocks_count(fs->super);
+ free_blocks_count = ext2fs_free_blocks_count(fs->super);
+
+ retval = ext2fs_close_free(&fs);
+ if (retval) {
+ com_err(prog_name, retval, "%s",
+ "while writing superblocks");
+ exit(1);
+ }
+
+ printf("Created filesystem with %u/%u inodes and %llu/%llu blocks\n",
+ inodes_count - free_inodes_count, inodes_count,
+ blocks_count - free_blocks_count, blocks_count);
+
+ remove_error_table(&et_ext2_error_table);
+ return 0;
+}
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