am 44d6342c: Remove mkdir() side effect, add .nomedia, utils. (9729b415) · Commits · e / os / android_system_core

include/cutils/fs.h

+8 −0

Original line number	Diff line number	Diff line
		@@ -55,6 +55,14 @@ extern int fs_read_atomic_int(const char* path, int* value);
		*/
		extern int fs_write_atomic_int(const char* path, int value);

		/*
		* Ensure that all directories along given path exist, creating parent
		* directories as needed. Validates that given path is absolute and that
		* it contains no relative "." or ".." paths or symlinks. Last path segment
		* is treated as filename and ignored, unless the path ends with "/".
		*/
		extern int fs_mkdirs(const char* path, mode_t mode);

		#ifdef __cplusplus
		}
		#endif

libcutils/fs.c

+90 −0

Original line number	Diff line number	Diff line
		@@ -16,6 +16,11 @@

		#define LOG_TAG "cutils"

		/* These defines are only needed because prebuilt headers are out of date */
		#define __USE_XOPEN2K8 1
		#define _ATFILE_SOURCE 1
		#define _GNU_SOURCE 1

		#include <cutils/fs.h>
		#include <cutils/log.h>

		@@ -27,6 +32,7 @@
		#include <string.h>
		#include <limits.h>
		#include <stdlib.h>
		#include <dirent.h>

		#define ALL_PERMS (S_ISUID \| S_ISGID \| S_ISVTX \| S_IRWXU \| S_IRWXG \| S_IRWXO)
		#define BUF_SIZE 64
		@@ -141,3 +147,87 @@ fail_closed:
		unlink(temp);
		return -1;
		}

		int fs_mkdirs(const char* path, mode_t mode) {
		int res = 0;
		int fd = 0;
		struct stat sb;
		char* buf = strdup(path);

		if (*buf != '/') {
		ALOGE("Relative paths are not allowed: %s", buf);
		res = -EINVAL;
		goto done;
		}

		if ((fd = open("/", 0)) == -1) {
		ALOGE("Failed to open(/): %s", strerror(errno));
		res = -errno;
		goto done;
		}

		char* segment = buf + 1;
		char* p = segment;
		while (*p != '\0') {
		if (*p == '/') {
		*p = '\0';

		if (!strcmp(segment, "..") \|\| !strcmp(segment, ".") \|\| !strcmp(segment, "")) {
		ALOGE("Invalid path: %s", buf);
		res = -EINVAL;
		goto done_close;
		}

		if (fstatat(fd, segment, &sb, AT_SYMLINK_NOFOLLOW) != 0) {
		if (errno == ENOENT) {
		/* Nothing there yet; let's create it! */
		if (mkdirat(fd, segment, mode) != 0) {
		if (errno == EEXIST) {
		/* We raced with someone; ignore */
		} else {
		ALOGE("Failed to mkdirat(%s): %s", buf, strerror(errno));
		res = -errno;
		goto done_close;
		}
		}
		} else {
		ALOGE("Failed to fstatat(%s): %s", buf, strerror(errno));
		res = -errno;
		goto done_close;
		}
		} else {
		if (S_ISLNK(sb.st_mode)) {
		ALOGE("Symbolic links are not allowed: %s", buf);
		res = -ELOOP;
		goto done_close;
		}
		if (!S_ISDIR(sb.st_mode)) {
		ALOGE("Existing segment not a directory: %s", buf);
		res = -ENOTDIR;
		goto done_close;
		}
		}

		/* Yay, segment is ready for us to step into */
		int next_fd;
		if ((next_fd = openat(fd, segment, 0)) == -1) {
		ALOGE("Failed to openat(%s): %s", buf, strerror(errno));
		res = -errno;
		goto done_close;
		}

		close(fd);
		fd = next_fd;

		*p = '/';
		segment = p + 1;
		}
		p++;
		}

		done_close:
		close(fd);
		done:
		free(buf);
		return res;
		}

rootdir/init.rc

+1 −1

Original line number	Diff line number	Diff line
		@@ -61,7 +61,7 @@ loglevel 3

		# See storage config details at http://source.android.com/tech/storage/
		mkdir /mnt/shell 0700 shell shell
		mkdir /storage 0050 root sdcard_r
		mkdir /storage 0751 root sdcard_r

		# Directory for putting things only root should see.
		mkdir /mnt/secure 0700 root root

sdcard/sdcard.c

+59 −51

Original line number	Diff line number	Diff line
		@@ -32,6 +32,7 @@
		#include <sys/resource.h>
		#include <sys/inotify.h>

		#include <cutils/fs.h>
		#include <cutils/hashmap.h>
		#include <cutils/multiuser.h>

		@@ -193,8 +194,9 @@ static int str_hash(void *key) {
		return hashmapHash(key, strlen(key));
		}

		static bool str_equals(void keyA, void keyB) {
		return strcmp(keyA, keyB) == 0;
		/** Test if two string keys are equal ignoring case */
		static bool str_icase_equals(void keyA, void keyB) {
		return strcasecmp(keyA, keyB) == 0;
		}

		static int int_hash(void *key) {
		@@ -401,6 +403,20 @@ static void attr_from_stat(struct fuse_attr attr, const struct stat s, const s
		attr->mode = (attr->mode & S_IFMT) \| filtered_mode;
		}

		static int touch(char* path, mode_t mode) {
		int fd = open(path, O_RDWR \| O_CREAT \| O_EXCL \| O_NOFOLLOW, mode);
		if (fd == -1) {
		if (errno == EEXIST) {
		return 0;
		} else {
		ERROR("Failed to open(%s): %s\n", path, strerror(errno));
		return -1;
		}
		}
		close(fd);
		return 0;
		}

		static void derive_permissions_locked(struct fuse* fuse, struct node *parent,
		struct node *node) {
		appid_t appid;
		@@ -429,37 +445,37 @@ static void derive_permissions_locked(struct fuse* fuse, struct node *parent,
		case PERM_ROOT:
		/* Assume masked off by default. */
		node->mode = 0770;
		if (!strcmp(node->name, "Android")) {
		if (!strcasecmp(node->name, "Android")) {
		/* App-specific directories inside; let anyone traverse */
		node->perm = PERM_ANDROID;
		node->mode = 0771;
		} else if (fuse->split_perms) {
		if (!strcmp(node->name, "DCIM")
		\|\| !strcmp(node->name, "Pictures")) {
		if (!strcasecmp(node->name, "DCIM")
		\|\| !strcasecmp(node->name, "Pictures")) {
		node->gid = AID_SDCARD_PICS;
		} else if (!strcmp(node->name, "Alarms")
		\|\| !strcmp(node->name, "Movies")
		\|\| !strcmp(node->name, "Music")
		\|\| !strcmp(node->name, "Notifications")
		\|\| !strcmp(node->name, "Podcasts")
		\|\| !strcmp(node->name, "Ringtones")) {
		} else if (!strcasecmp(node->name, "Alarms")
		\|\| !strcasecmp(node->name, "Movies")
		\|\| !strcasecmp(node->name, "Music")
		\|\| !strcasecmp(node->name, "Notifications")
		\|\| !strcasecmp(node->name, "Podcasts")
		\|\| !strcasecmp(node->name, "Ringtones")) {
		node->gid = AID_SDCARD_AV;
		}
		}
		break;
		case PERM_ANDROID:
		if (!strcmp(node->name, "data")) {
		if (!strcasecmp(node->name, "data")) {
		/* App-specific directories inside; let anyone traverse */
		node->perm = PERM_ANDROID_DATA;
		node->mode = 0771;
		} else if (!strcmp(node->name, "obb")) {
		} else if (!strcasecmp(node->name, "obb")) {
		/* App-specific directories inside; let anyone traverse */
		node->perm = PERM_ANDROID_OBB;
		node->mode = 0771;
		/* Single OBB directory is always shared */
		node->graft_path = fuse->obbpath;
		node->graft_pathlen = strlen(fuse->obbpath);
		} else if (!strcmp(node->name, "user")) {
		} else if (!strcasecmp(node->name, "user")) {
		/* User directories must only be accessible to system, protected
		* by sdcard_all. Zygote will bind mount the appropriate user-
		* specific path. */
		@@ -505,9 +521,9 @@ static bool check_caller_access_to_name(struct fuse* fuse,
		const char* name, int mode, bool has_rw) {
		/* Always block security-sensitive files at root */
		if (parent_node && parent_node->perm == PERM_ROOT) {
		if (!strcmp(name, "autorun.inf")
		\|\| !strcmp(name, ".android_secure")
		\|\| !strcmp(name, "android_secure")) {
		if (!strcasecmp(name, "autorun.inf")
		\|\| !strcasecmp(name, ".android_secure")
		\|\| !strcasecmp(name, "android_secure")) {
		return false;
		}
		}
		@@ -517,8 +533,9 @@ static bool check_caller_access_to_name(struct fuse* fuse,
		return true;
		}

		/* Root or shell always have access */
		if (hdr->uid == 0 \|\| hdr->uid == AID_SHELL) {
		/* Root always has access; access for any other UIDs should always
		* be controlled through packages.list. */
		if (hdr->uid == 0) {
		return true;
		}

		@@ -696,9 +713,10 @@ static void fuse_init(struct fuse fuse, int fd, const char source_path,
		fuse->root.perm = PERM_LEGACY_PRE_ROOT;
		fuse->root.mode = 0771;
		fuse->root.gid = fs_gid;
		fuse->package_to_appid = hashmapCreate(256, str_hash, str_equals);
		fuse->package_to_appid = hashmapCreate(256, str_hash, str_icase_equals);
		fuse->appid_with_rw = hashmapCreate(128, int_hash, int_equals);
		snprintf(fuse->obbpath, sizeof(fuse->obbpath), "%s/obb", source_path);
		fs_prepare_dir(fuse->obbpath, 0775, getuid(), getgid());
		break;
		case DERIVE_UNIFIED:
		/* Unified multiuser layout which places secondary user_id under
		@@ -706,7 +724,7 @@ static void fuse_init(struct fuse fuse, int fd, const char source_path,
		fuse->root.perm = PERM_ROOT;
		fuse->root.mode = 0771;
		fuse->root.gid = fs_gid;
		fuse->package_to_appid = hashmapCreate(256, str_hash, str_equals);
		fuse->package_to_appid = hashmapCreate(256, str_hash, str_icase_equals);
		fuse->appid_with_rw = hashmapCreate(128, int_hash, int_equals);
		snprintf(fuse->obbpath, sizeof(fuse->obbpath), "%s/Android/obb", source_path);
		break;
		@@ -752,37 +770,8 @@ static int fuse_reply_entry(struct fuse* fuse, __u64 unique,
		struct stat s;

		if (lstat(path, &s) < 0) {
		/* But wait! We'll automatically create a directory if its
		* a valid package name under data or obb, since apps may not
		* have enough permissions to create for themselves. */
		if (errno == ENOENT && (parent->perm == PERM_ANDROID_DATA
		\|\| parent->perm == PERM_ANDROID_OBB)) {
		TRACE("automatically creating %s\n", path);

		pthread_mutex_lock(&fuse->lock);
		bool validPackage = hashmapContainsKey(fuse->package_to_appid, (char*) name);
		pthread_mutex_unlock(&fuse->lock);

		if (!validPackage) {
		return -ENOENT;
		}
		if (mkdir(path, 0775) == -1) {
		/* We might have raced with ourselves and already created */
		if (errno != EEXIST) {
		ERROR("failed to mkdir(%s): %s\n", name, strerror(errno));
		return -ENOENT;
		}
		}

		/* It should exist this time around! */
		if (lstat(path, &s) < 0) {
		ERROR("failed to lstat(%s): %s\n", name, strerror(errno));
		return -errno;
		}
		} else {
		return -errno;
		}
		}

		pthread_mutex_lock(&fuse->lock);
		node = acquire_or_create_child_locked(fuse, parent, name, actual_name);
		@@ -1006,6 +995,25 @@ static int handle_mkdir(struct fuse* fuse, struct fuse_handler* handler,
		if (mkdir(child_path, mode) < 0) {
		return -errno;
		}

		/* When creating /Android/data and /Android/obb, mark them as .nomedia */
		if (parent_node->perm == PERM_ANDROID && !strcasecmp(name, "data")) {
		char nomedia[PATH_MAX];
		snprintf(nomedia, PATH_MAX, "%s/.nomedia", child_path);
		if (touch(nomedia, 0664) != 0) {
		ERROR("Failed to touch(%s): %s\n", nomedia, strerror(errno));
		return -ENOENT;
		}
		}
		if (parent_node->perm == PERM_ANDROID && !strcasecmp(name, "obb")) {
		char nomedia[PATH_MAX];
		snprintf(nomedia, PATH_MAX, "%s/.nomedia", fuse->obbpath);
		if (touch(nomedia, 0664) != 0) {
		ERROR("Failed to touch(%s): %s\n", nomedia, strerror(errno));
		return -ENOENT;
		}
		}

		return fuse_reply_entry(fuse, hdr->unique, parent_node, name, actual_name, child_path);
		}