Add back hook for inserting OEM specific iptables rules.

The functionality was lost during merge in ICS branch.
This patch is adding back OEM iptables hook in netd.

Bug:5862460
Change-Id: I9444b8c53e8b84fea2002c2c1d9ba42e45ae5f0c
diff --git a/Android.mk b/Android.mk
index dbf9b7d..c20898b 100644
--- a/Android.mk
+++ b/Android.mk
@@ -17,6 +17,7 @@
                   SoftapController.cpp                 \
                   TetherController.cpp                 \
                   ThrottleController.cpp               \
+                  oem_iptables_hook.cpp                \
                   logwrapper.c                         \
                   main.cpp                             \
 
diff --git a/BandwidthController.cpp b/BandwidthController.cpp
index be3cb28..4c15394 100644
--- a/BandwidthController.cpp
+++ b/BandwidthController.cpp
@@ -45,6 +45,7 @@
 extern "C" int system_nosh(const char *command);
 
 #include "BandwidthController.h"
+#include "oem_iptables_hook.h"
 
 /* Alphabetical */
 const char BandwidthController::ALERT_IPT_TEMPLATE[] = "%s %s %s -m quota2 ! --quota %lld --name %s";
@@ -231,6 +232,8 @@
     res = runCommands(sizeof(IPT_BASIC_ACCOUNTING_COMMANDS) / sizeof(char*),
             IPT_BASIC_ACCOUNTING_COMMANDS, RunCmdFailureBad);
 
+    setupOemIptablesHook();
+
     return res;
 
 }
@@ -239,6 +242,7 @@
     /* The IPT_CLEANUP_COMMANDS are allowed to fail. */
     runCommands(sizeof(IPT_CLEANUP_COMMANDS) / sizeof(char*),
             IPT_CLEANUP_COMMANDS, RunCmdFailureOk);
+    setupOemIptablesHook();
     return 0;
 }
 
diff --git a/NatController.cpp b/NatController.cpp
index ed1b095..7f1bc60 100644
--- a/NatController.cpp
+++ b/NatController.cpp
@@ -29,6 +29,7 @@
 
 #include "NatController.h"
 #include "SecondaryTableController.h"
+#include "oem_iptables_hook.h"
 
 extern "C" int system_nosh(const char *command);
 
@@ -82,6 +83,8 @@
     runCmd(IP_PATH, "route flush cache");
 
     natCount = 0;
+
+    setupOemIptablesHook();
     return 0;
 }
 
@@ -263,13 +266,8 @@
     }
 
     if (--natCount <= 0) {
-        char bootmode[PROPERTY_VALUE_MAX] = {0};
-        property_get("ro.bootmode", bootmode, "unknown");
-        if (0 != strcmp("bp-tools", bootmode)) {
-            // handle decrement to 0 case (do reset to defaults) and erroneous dec below 0
-            setDefaults();
-        }
-        natCount = 0;
+        // handle decrement to 0 case (do reset to defaults) and erroneous dec below 0
+        setDefaults();
     }
     return 0;
 }
diff --git a/oem_iptables_hook.cpp b/oem_iptables_hook.cpp
new file mode 100644
index 0000000..e50ea6a
--- /dev/null
+++ b/oem_iptables_hook.cpp
@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#define LOG_TAG "OemIptablesHook"
+#include <cutils/log.h>
+
+extern "C" int system_nosh(const char *command);
+
+static char IPTABLES_PATH[] = "/system/bin/iptables";
+static char OEM_SCRIPT_PATH[] = "/system/bin/oem-iptables-init.sh";
+
+static int runIptablesCmd(const char *cmd) {
+    char *buffer;
+    size_t len = strnlen(cmd, 255);
+    int res;
+
+    if (len == 255) {
+        LOGE("command too long");
+        return -1;
+    }
+
+    asprintf(&buffer, "%s %s", IPTABLES_PATH, cmd);
+    res = system_nosh(buffer);
+    free(buffer);
+    return res;
+}
+
+static bool oemSetupHooks() {
+    // Order is important!
+    // -N to create the chain (no-op if already exist).
+    // -D to delete any pre-existing jump rule, to prevent dupes (no-op if doesn't exist)
+    // -I to insert our jump rule into the default chain
+
+    runIptablesCmd("-N oem_out");
+    runIptablesCmd("-D OUTPUT -j oem_out");
+    if (runIptablesCmd("-I OUTPUT -j oem_out"))
+        return false;
+
+    runIptablesCmd("-N oem_fwd");
+    runIptablesCmd("-D FORWARD -j oem_fwd");
+    if (runIptablesCmd("-I FORWARD -j oem_fwd"))
+        return false;
+
+    runIptablesCmd("-t nat -N oem_nat_pre");
+    runIptablesCmd("-t nat -D PREROUTING -j oem_nat_pre");
+    if (runIptablesCmd("-t nat -I PREROUTING -j oem_nat_pre"))
+        return false;
+
+    return true;
+}
+
+static bool oemCleanupHooks() {
+    // Order is important!
+    // -D to remove ref to the chain
+    // -F to empty the chain
+    // -X to delete the chain
+
+    runIptablesCmd("-D OUTPUT -j oem_out");
+    runIptablesCmd("-F oem_out");
+    runIptablesCmd("-X oem_out");
+
+    runIptablesCmd("-D FORWARD -j oem_fwd");
+    runIptablesCmd("-F oem_fwd");
+    runIptablesCmd("-X oem_fwd");
+
+    runIptablesCmd("-t nat -D PREROUTING -j oem_nat_pre");
+    runIptablesCmd("-t nat -F oem_nat_pre");
+    runIptablesCmd("-t nat -X oem_nat_pre");
+
+    return true;
+}
+
+static bool oemInitChains() {
+    int ret = system(OEM_SCRIPT_PATH);
+    if ((-1 == ret) || (0 != WEXITSTATUS(ret))) {
+        LOGE("%s failed: %s", OEM_SCRIPT_PATH, strerror(errno));
+        oemCleanupHooks();
+        return false;
+    }
+    return true;
+}
+
+
+void setupOemIptablesHook() {
+    if (0 == access(OEM_SCRIPT_PATH, R_OK | X_OK)) {
+        // The call to oemCleanupHooks() is superfluous when done on bootup,
+        // but is needed for the case where netd has crashed/stopped and is
+        // restarted.
+        if (oemCleanupHooks() && oemSetupHooks() && oemInitChains()) {
+            LOGI("OEM iptable hook installed.");
+        }
+    }
+}
diff --git a/oem_iptables_hook.h b/oem_iptables_hook.h
new file mode 100644
index 0000000..f5696ba
--- /dev/null
+++ b/oem_iptables_hook.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef _OEM_IPTABLES_HOOK_H
+#define _OEM_IPTABLES_HOOK_H
+
+void setupOemIptablesHook();
+
+#endif