Merge "fd_utils: address a couple of TODOs." (a34d01d1) · Commits · e / os / android_frameworks_base

core/jni/fd_utils.cpp

+24 −59

Original line number	Diff line number	Diff line
		@@ -26,7 +26,9 @@
		#include <sys/un.h>
		#include <unistd.h>

		#include <android-base/file.h>
		#include <android-base/logging.h>
		#include <android-base/stringprintf.h>
		#include <android-base/strings.h>

		// Static whitelist of open paths that the zygote is allowed to keep open.
		@@ -65,9 +67,10 @@ bool FileDescriptorWhitelist::IsAllowed(const std::string& path) const {
		return true;
		}

		static const std::string kFrameworksPrefix = "/system/framework/";
		static const std::string kJarSuffix = ".jar";
		if (StartsWith(path, kFrameworksPrefix) && EndsWith(path, kJarSuffix)) {
		static const char* kFrameworksPrefix = "/system/framework/";
		static const char* kJarSuffix = ".jar";
		if (android::base::StartsWith(path, kFrameworksPrefix)
		&& android::base::EndsWith(path, kJarSuffix)) {
		return true;
		}

		@@ -79,28 +82,31 @@ bool FileDescriptorWhitelist::IsAllowed(const std::string& path) const {
		// /data/resource-cache/system@vendor@overlay@framework-res.apk@idmap
		// /data/resource-cache/system@vendor@overlay-subdir@pg@framework-res.apk@idmap
		// See AssetManager.cpp for more details on overlay-subdir.
		static const std::string kOverlayDir = "/system/vendor/overlay/";
		static const std::string kVendorOverlayDir = "/vendor/overlay";
		static const std::string kOverlaySubdir = "/system/vendor/overlay-subdir/";
		static const std::string kApkSuffix = ".apk";

		if ((StartsWith(path, kOverlayDir) \|\| StartsWith(path, kOverlaySubdir)
		\|\| StartsWith(path, kVendorOverlayDir))
		&& EndsWith(path, kApkSuffix)
		static const char* kOverlayDir = "/system/vendor/overlay/";
		static const char* kVendorOverlayDir = "/vendor/overlay";
		static const char* kOverlaySubdir = "/system/vendor/overlay-subdir/";
		static const char* kApkSuffix = ".apk";

		if ((android::base::StartsWith(path, kOverlayDir)
		\|\| android::base::StartsWith(path, kOverlaySubdir)
		\|\| android::base::StartsWith(path, kVendorOverlayDir))
		&& android::base::EndsWith(path, kApkSuffix)
		&& path.find("/../") == std::string::npos) {
		return true;
		}

		static const std::string kOverlayIdmapPrefix = "/data/resource-cache/";
		static const std::string kOverlayIdmapSuffix = ".apk@idmap";
		if (StartsWith(path, kOverlayIdmapPrefix) && EndsWith(path, kOverlayIdmapSuffix)
		static const char* kOverlayIdmapPrefix = "/data/resource-cache/";
		static const char* kOverlayIdmapSuffix = ".apk@idmap";
		if (android::base::StartsWith(path, kOverlayIdmapPrefix)
		&& android::base::EndsWith(path, kOverlayIdmapSuffix)
		&& path.find("/../") == std::string::npos) {
		return true;
		}

		// All regular files that are placed under this path are whitelisted automatically.
		static const std::string kZygoteWhitelistPath = "/vendor/zygote_whitelist/";
		if (StartsWith(path, kZygoteWhitelistPath) && path.find("/../") == std::string::npos) {
		static const char* kZygoteWhitelistPath = "/vendor/zygote_whitelist/";
		if (android::base::StartsWith(path, kZygoteWhitelistPath)
		&& path.find("/../") == std::string::npos) {
		return true;
		}

		@@ -111,24 +117,6 @@ FileDescriptorWhitelist::FileDescriptorWhitelist()
		: whitelist_() {
		}

		// TODO: Call android::base::StartsWith instead of copying the code here.
		// static
		bool FileDescriptorWhitelist::StartsWith(const std::string& str,
		const std::string& prefix) {
		return str.compare(0, prefix.size(), prefix) == 0;
		}

		// TODO: Call android::base::EndsWith instead of copying the code here.
		// static
		bool FileDescriptorWhitelist::EndsWith(const std::string& str,
		const std::string& suffix) {
		if (suffix.size() > str.size()) {
		return false;
		}

		return str.compare(str.size() - suffix.size(), suffix.size(), suffix) == 0;
		}

		FileDescriptorWhitelist* FileDescriptorWhitelist::instance_ = nullptr;

		// static
		@@ -174,7 +162,8 @@ FileDescriptorInfo* FileDescriptorInfo::CreateFromFd(int fd) {
		}

		std::string file_path;
		if (!Readlink(fd, &file_path)) {
		const std::string fd_path = android::base::StringPrintf("/proc/self/fd/%d", fd);
		if (!android::base::Readlink(fd_path, &file_path)) {
		return NULL;
		}

		@@ -299,30 +288,6 @@ FileDescriptorInfo::FileDescriptorInfo(struct stat stat, const std::string& file
		is_sock(false) {
		}

		// TODO: Call android::base::Readlink instead of copying the code here.
		// static
		bool FileDescriptorInfo::Readlink(const int fd, std::string* result) {
		char path[64];
		snprintf(path, sizeof(path), "/proc/self/fd/%d", fd);

		// Code copied from android::base::Readlink starts here :

		// Annoyingly, the readlink system call returns EINVAL for a zero-sized buffer,
		// and truncates to whatever size you do supply, so it can't be used to query.
		// We could call lstat first, but that would introduce a race condition that
		// we couldn't detect.
		// ext2 and ext4 both have PAGE_SIZE limitations, so we assume that here.
		char buf[4096];
		ssize_t len = readlink(path, buf, sizeof(buf));
		if (len == -1) {
		PLOG(ERROR) << "Readlink on " << fd << " failed.";
		return false;
		}

		result->assign(buf, len);
		return true;
		}

		// static
		bool FileDescriptorInfo::GetSocketName(const int fd, std::string* result) {
		sockaddr_storage ss;

core/jni/fd_utils.h

+0 −6

Original line number	Diff line number	Diff line
		@@ -59,10 +59,6 @@ class FileDescriptorWhitelist {
		private:
		FileDescriptorWhitelist();

		static bool StartsWith(const std::string& str, const std::string& prefix);

		static bool EndsWith(const std::string& str, const std::string& suffix);

		static FileDescriptorWhitelist* instance_;

		std::vector<std::string> whitelist_;
		@@ -99,8 +95,6 @@ class FileDescriptorInfo {
		FileDescriptorInfo(struct stat stat, const std::string& file_path, int fd, int open_flags,
		int fd_flags, int fs_flags, off_t offset);

		static bool Readlink(const int fd, std::string* result);

		// Returns the locally-bound name of the socket \|fd\|. Returns true
		// iff. all of the following hold :
		//