commit b08654ca0450d021da709a762ab509a8d4f87d40
author Motomu Utsumi <motomuman@google.com> Wed May 11 05:56:26 2022 +0000
committer Motomu Utsumi <motomuman@google.com> Mon May 16 10:40:59 2022 +0000
tree eced2c69b68931d936ab7050c3565ce00ffaa2a7
parent 77a794868fd478dadb90e5e1fa71debd7257db4d

Block incoming packets in VPN Lockdown mode.

Currently, even when VPN Lockdown mode is enabled, incoming packets are
not dropped if VPN is not connected.

This commit fixed this issue.
After this commit, If VPN Lockdown mode is enabled, incoming packets
are dropped regardless of the VPN connectivity.

Bug: 206482423
Test: atest TrafficControllerTest ConnectivityServiceTest PermissionMonitorTest
Change-Id: If52ece613c8aac1073355e43b6fb9cb3fcc87d1d

service/native/TrafficController.cpp

diff --git a/service/native/TrafficController.cpp b/service/native/TrafficController.cpp
index 473c9e3..5581c40 100644
--- a/service/native/TrafficController.cpp
+++ b/service/native/TrafficController.cpp
@@ -98,6 +98,7 @@
     FLAG_MSG_TRANS(matchType, RESTRICTED_MATCH, match);
     FLAG_MSG_TRANS(matchType, LOW_POWER_STANDBY_MATCH, match);
     FLAG_MSG_TRANS(matchType, IIF_MATCH, match);
+    FLAG_MSG_TRANS(matchType, LOCKDOWN_VPN_MATCH, match);
     if (match) {
         return StringPrintf("Unknown match: %u", match);
     }
@@ -286,16 +287,13 @@
 }
 
 Status TrafficController::addRule(uint32_t uid, UidOwnerMatchType match, uint32_t iif) {
-    // iif should be non-zero if and only if match == MATCH_IIF
-    if (match == IIF_MATCH && iif == 0) {
-        return statusFromErrno(EINVAL, "Interface match must have nonzero interface index");
-    } else if (match != IIF_MATCH && iif != 0) {
+    if (match != IIF_MATCH && iif != 0) {
         return statusFromErrno(EINVAL, "Non-interface match must have zero interface index");
     }
     auto oldMatch = mUidOwnerMap.readValue(uid);
     if (oldMatch.ok()) {
         UidOwnerValue newMatch = {
-                .iif = iif ? iif : oldMatch.value().iif,
+                .iif = (match == IIF_MATCH) ? iif : oldMatch.value().iif,
                 .rule = oldMatch.value().rule | match,
         };
         RETURN_IF_NOT_OK(mUidOwnerMap.writeValue(uid, newMatch, BPF_ANY));
@@ -335,6 +333,8 @@
             return ALLOWLIST;
         case LOW_POWER_STANDBY:
             return ALLOWLIST;
+        case LOCKDOWN:
+            return DENYLIST;
         case NONE:
         default:
             return DENYLIST;
@@ -360,6 +360,9 @@
         case LOW_POWER_STANDBY:
             res = updateOwnerMapEntry(LOW_POWER_STANDBY_MATCH, uid, rule, type);
             break;
+        case LOCKDOWN:
+            res = updateOwnerMapEntry(LOCKDOWN_VPN_MATCH, uid, rule, type);
+            break;
         case NONE:
         default:
             ALOGW("Unknown child chain: %d", chain);
@@ -399,9 +402,6 @@
 
 Status TrafficController::addUidInterfaceRules(const int iif,
                                                const std::vector<int32_t>& uidsToAdd) {
-    if (!iif) {
-        return statusFromErrno(EINVAL, "Interface rule must specify interface");
-    }
     std::lock_guard guard(mMutex);
 
     for (auto uid : uidsToAdd) {