adb: Support 'adb enable/disable-verity' when using AVB. (1e033d68) · Commits · e / os / android_system_core

adb/Android.mk

+1 −0

Original line number	Diff line number	Diff line
		@@ -363,6 +363,7 @@ LOCAL_SANITIZE := $(adb_target_sanitize)
		LOCAL_STRIP_MODULE := keep_symbols
		LOCAL_STATIC_LIBRARIES := \
		libadbd \
		libavb_user \
		libbase \
		libbootloader_message \
		libfs_mgr \

adb/set_verity_enable_state_service.cpp

+85 −24

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@

		#include <fcntl.h>
		#include <inttypes.h>
		#include <libavb_user/libavb_user.h>
		#include <stdarg.h>
		#include <stdio.h>
		#include <sys/stat.h>
		@@ -45,13 +46,12 @@ static const bool kAllowDisableVerity = false;
		#endif

		/* Turn verity on/off */
		static int set_verity_enabled_state(int fd, const char *block_device,
		const char* mount_point, bool enable)
		{
		static bool set_verity_enabled_state(int fd, const char* block_device, const char* mount_point,
		bool enable) {
		if (!make_block_device_writable(block_device)) {
		WriteFdFmt(fd, "Could not make block device %s writable (%s).\n",
		block_device, strerror(errno));
		return -1;
		return false;
		}

		fec::io fh(block_device, O_RDWR);
		@@ -59,39 +59,84 @@ static int set_verity_enabled_state(int fd, const char *block_device,
		if (!fh) {
		WriteFdFmt(fd, "Could not open block device %s (%s).\n", block_device, strerror(errno));
		WriteFdFmt(fd, "Maybe run adb root?\n");
		return -1;
		return false;
		}

		fec_verity_metadata metadata;

		if (!fh.get_verity_metadata(metadata)) {
		WriteFdFmt(fd, "Couldn't find verity metadata!\n");
		return -1;
		return false;
		}

		if (!enable && metadata.disabled) {
		WriteFdFmt(fd, "Verity already disabled on %s\n", mount_point);
		return -1;
		return false;
		}

		if (enable && !metadata.disabled) {
		WriteFdFmt(fd, "Verity already enabled on %s\n", mount_point);
		return -1;
		return false;
		}

		if (!fh.set_verity_status(enable)) {
		WriteFdFmt(fd, "Could not set verity %s flag on device %s with error %s\n",
		enable ? "enabled" : "disabled",
		block_device, strerror(errno));
		return -1;
		return false;
		}

		WriteFdFmt(fd, "Verity %s on %s\n", enable ? "enabled" : "disabled", mount_point);
		return 0;
		return true;
		}

		/* Helper function to get A/B suffix, if any. If the device isn't
		* using A/B the empty string is returned. Otherwise either "_a",
		* "_b", ... is returned.
		*
		* Note that since sometime in O androidboot.slot_suffix is deprecated
		* and androidboot.slot should be used instead. Since bootloaders may
		* be out of sync with the OS, we check both and for extra safety
		* prepend a leading underscore if there isn't one already.
		*/
		static std::string get_ab_suffix() {
		std::string ab_suffix = android::base::GetProperty("ro.boot.slot_suffix", "");
		if (ab_suffix == "") {
		ab_suffix = android::base::GetProperty("ro.boot.slot", "");
		}
		if (ab_suffix.size() > 0 && ab_suffix[0] != '_') {
		ab_suffix = std::string("_") + ab_suffix;
		}
		return ab_suffix;
		}

		/* Use AVB to turn verity on/off */
		static bool set_avb_verity_enabled_state(int fd, AvbOps* ops, bool enable_verity) {
		std::string ab_suffix = get_ab_suffix();

		bool verity_enabled;
		if (!avb_user_verity_get(ops, ab_suffix.c_str(), &verity_enabled)) {
		WriteFdFmt(fd, "Error getting verity state\n");
		return false;
		}

		if ((verity_enabled && enable_verity) \|\| (!verity_enabled && !enable_verity)) {
		WriteFdFmt(fd, "verity is already %s\n", verity_enabled ? "enabled" : "disabled");
		return false;
		}

		if (!avb_user_verity_set(ops, ab_suffix.c_str(), enable_verity)) {
		WriteFdFmt(fd, "Error setting verity\n");
		return false;
		}

		WriteFdFmt(fd, "Successfully %s verity\n", enable_verity ? "enabled" : "disabled");
		return true;
		}

		void set_verity_enabled_state_service(int fd, void* cookie) {
		unique_fd closer(fd);
		bool any_changed = false;

		bool enable = (cookie != NULL);
		if (!kAllowDisableVerity) {
		@@ -108,6 +153,23 @@ void set_verity_enabled_state_service(int fd, void* cookie) {
		return;
		}

		// Figure out if we're using VB1.0 or VB2.0 (aka AVB).
		std::string vbmeta_hash = android::base::GetProperty("ro.boot.vbmeta.digest", "");
		if (vbmeta_hash != "") {
		// Yep, the system is using AVB (by contract, androidboot.vbmeta.hash is
		// set by the bootloader when using AVB).
		AvbOps* ops = avb_ops_user_new();
		if (ops == nullptr) {
		WriteFdFmt(fd, "Error getting AVB ops\n");
		return;
		}
		if (set_avb_verity_enabled_state(fd, ops, enable)) {
		any_changed = true;
		}
		avb_ops_user_free(ops);
		} else {
		// Not using AVB - assume VB1.0.

		// read all fstab entries at once from all sources
		fstab = fs_mgr_read_fstab_default();
		if (!fstab) {
		@@ -116,16 +178,15 @@ void set_verity_enabled_state_service(int fd, void* cookie) {
		}

		// Loop through entries looking for ones that vold manages.
		bool any_changed = false;
		for (int i = 0; i < fstab->num_entries; i++) {
		if (fs_mgr_is_verified(&fstab->recs[i])) {
		if (!set_verity_enabled_state(fd, fstab->recs[i].blk_device,
		fstab->recs[i].mount_point,
		enable)) {
		if (set_verity_enabled_state(fd, fstab->recs[i].blk_device,
		fstab->recs[i].mount_point, enable)) {
		any_changed = true;
		}
		}
		}
		}

		if (any_changed) {
		WriteFdFmt(fd, "Now reboot your device for settings to take effect\n");