Merge "init: Add option to listen on sockets before starting service." into tm-qpr-dev
diff --git a/init/README.md b/init/README.md
index 13c6ebd..aaafe78 100644
--- a/init/README.md
+++ b/init/README.md
@@ -352,9 +352,10 @@
 
 `socket <name> <type> <perm> [ <user> [ <group> [ <seclabel> ] ] ]`
 > Create a UNIX domain socket named /dev/socket/_name_ and pass its fd to the
-  launched process.  _type_ must be "dgram", "stream" or "seqpacket".  _type_
-  may end with "+passcred" to enable SO_PASSCRED on the socket. User and
-  group default to 0.  'seclabel' is the SELinux security context for the
+  launched process.  The socket is created synchronously when the service starts.
+  _type_ must be "dgram", "stream" or "seqpacket".  _type_ may end with "+passcred"
+  to enable SO_PASSCRED on the socket or "+listen" to synchronously make it a listening socket.
+  User and group default to 0.  'seclabel' is the SELinux security context for the
   socket.  It defaults to the service security context, as specified by
   seclabel or computed based on the service executable file security context.
   For native executables see libcutils android\_get\_control\_socket().
diff --git a/init/property_service.cpp b/init/property_service.cpp
index 9f7c215..26341b1 100644
--- a/init/property_service.cpp
+++ b/init/property_service.cpp
@@ -1379,7 +1379,8 @@
     StartSendingMessages();
 
     if (auto result = CreateSocket(PROP_SERVICE_NAME, SOCK_STREAM | SOCK_CLOEXEC | SOCK_NONBLOCK,
-                                   false, 0666, 0, 0, {});
+                                   /*passcred=*/false, /*should_listen=*/false, 0666, /*uid=*/0,
+                                   /*gid=*/0, /*socketcon=*/{});
         result.ok()) {
         property_set_fd = *result;
     } else {
diff --git a/init/service_parser.cpp b/init/service_parser.cpp
index 9e914ee..1ee309d 100644
--- a/init/service_parser.cpp
+++ b/init/service_parser.cpp
@@ -434,11 +434,14 @@
                        << "' instead.";
     }
 
-    if (types.size() > 1) {
-        if (types.size() == 2 && types[1] == "passcred") {
+    for (size_t i = 1; i < types.size(); i++) {
+        if (types[i] == "passcred") {
             socket.passcred = true;
+        } else if (types[i] == "listen") {
+            socket.listen = true;
         } else {
-            return Error() << "Only 'passcred' may be used to modify the socket type";
+            return Error() << "Unknown socket type decoration '" << types[i]
+                           << "'. Known values are ['passcred', 'listen']";
         }
     }
 
diff --git a/init/service_utils.cpp b/init/service_utils.cpp
index eed5c65..d19f5ee 100644
--- a/init/service_utils.cpp
+++ b/init/service_utils.cpp
@@ -168,7 +168,8 @@
 
 Result<Descriptor> SocketDescriptor::Create(const std::string& global_context) const {
     const auto& socket_context = context.empty() ? global_context : context;
-    auto result = CreateSocket(name, type | SOCK_CLOEXEC, passcred, perm, uid, gid, socket_context);
+    auto result = CreateSocket(name, type | SOCK_CLOEXEC, passcred, listen, perm, uid, gid,
+                               socket_context);
     if (!result.ok()) {
         return result.error();
     }
diff --git a/init/service_utils.h b/init/service_utils.h
index 9b65dca..65a2012 100644
--- a/init/service_utils.h
+++ b/init/service_utils.h
@@ -54,6 +54,7 @@
     int perm = 0;
     std::string context;
     bool passcred = false;
+    bool listen = false;
     bool persist = false;
 
     // Create() creates the named unix domain socket in /dev/socket and returns a Descriptor object.
diff --git a/init/util.cpp b/init/util.cpp
index d1e518b..5b3a73c 100644
--- a/init/util.cpp
+++ b/init/util.cpp
@@ -86,8 +86,8 @@
  * daemon. We communicate the file descriptor's value via the environment
  * variable ANDROID_SOCKET_ENV_PREFIX<name> ("ANDROID_SOCKET_foo").
  */
-Result<int> CreateSocket(const std::string& name, int type, bool passcred, mode_t perm, uid_t uid,
-                         gid_t gid, const std::string& socketcon) {
+Result<int> CreateSocket(const std::string& name, int type, bool passcred, bool should_listen,
+                         mode_t perm, uid_t uid, gid_t gid, const std::string& socketcon) {
     if (!socketcon.empty()) {
         if (setsockcreatecon(socketcon.c_str()) == -1) {
             return ErrnoError() << "setsockcreatecon(\"" << socketcon << "\") failed";
@@ -142,6 +142,9 @@
     if (fchmodat(AT_FDCWD, addr.sun_path, perm, AT_SYMLINK_NOFOLLOW)) {
         return ErrnoError() << "Failed to fchmodat socket '" << addr.sun_path << "'";
     }
+    if (should_listen && listen(fd, /* use OS maximum */ 1 << 30)) {
+        return ErrnoError() << "Failed to listen on socket '" << addr.sun_path << "'";
+    }
 
     LOG(INFO) << "Created socket '" << addr.sun_path << "'"
               << ", mode " << std::oct << perm << std::dec
diff --git a/init/util.h b/init/util.h
index bf53675..1e2eef0 100644
--- a/init/util.h
+++ b/init/util.h
@@ -44,8 +44,8 @@
 
 extern void (*trigger_shutdown)(const std::string& command);
 
-Result<int> CreateSocket(const std::string& name, int type, bool passcred, mode_t perm, uid_t uid,
-                         gid_t gid, const std::string& socketcon);
+Result<int> CreateSocket(const std::string& name, int type, bool passcred, bool should_listen,
+                         mode_t perm, uid_t uid, gid_t gid, const std::string& socketcon);
 
 Result<std::string> ReadFile(const std::string& path);
 Result<void> WriteFile(const std::string& path, const std::string& content);