adb: Support 'adb enable/disable-verity' when using AVB.
Link with libavb_user and use this to enable/disable dm-verity if AVB
is in use.
Bug: 34124301
Test: Manually tested.
Change-Id: Ic03651312b955081cb3c126f6dafc46d6eeec0da
diff --git a/set_verity_enable_state_service.cpp b/set_verity_enable_state_service.cpp
index d4dd256..b2b1c18 100644
--- a/set_verity_enable_state_service.cpp
+++ b/set_verity_enable_state_service.cpp
@@ -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 @@
#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 @@
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) {
@@ -108,21 +153,37 @@
return;
}
- // read all fstab entries at once from all sources
- fstab = fs_mgr_read_fstab_default();
- if (!fstab) {
- WriteFdFmt(fd, "Failed to read fstab\nMaybe run adb root?\n");
- 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.
- // 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)) {
- any_changed = true;
+ // read all fstab entries at once from all sources
+ fstab = fs_mgr_read_fstab_default();
+ if (!fstab) {
+ WriteFdFmt(fd, "Failed to read fstab\nMaybe run adb root?\n");
+ return;
+ }
+
+ // Loop through entries looking for ones that vold manages.
+ 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)) {
+ any_changed = true;
+ }
}
}
}