Move android_get_control_socket out of line

android_get_control_socket has a warning from the implicit cast from
long to int.  The warning was being hidden because cutils/sockets.h was
included with -isystem.  Move android_get_control_socket to sockets.cpp,
since we don't want header only dependencies anyways, and fix the
warning with a range check and a static_cast.

Bug: 31492149
Test: m -j <module that uses sockets.h and -Wall>
Change-Id: I1f394ab26d4ec8a7dd0e7907c10416d7f8647624

3 files changed, 24 insertions, 22 deletions

diff --git a/include/cutils/sockets.h b/include/cutils/sockets.h
index 783bd0bea..a93c8eaa4 100644
--- a/include/cutils/sockets.h
+++ b/include/cutils/sockets.h
@@ -18,6 +18,7 @@
 #define __CUTILS_SOCKETS_H
 
 #include <errno.h>
+#include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -51,28 +52,8 @@ extern "C" {
  * android_get_control_socket - simple helper function to get the file
  * descriptor of our init-managed Unix domain socket. `name' is the name of the
  * socket, as given in init.rc. Returns -1 on error.
- *
- * This is inline and not in libcutils proper because we want to use this in
- * third-party daemons with minimal modification.
  */
-static inline int android_get_control_socket(const char* name)
-{
-	char key[64];
-	snprintf(key, sizeof(key), ANDROID_SOCKET_ENV_PREFIX "%s", name);
-
-	const char* val = getenv(key);
-	if (!val) {
-		return -1;
-	}
-
-	errno = 0;
-	int fd = strtol(val, NULL, 10);
-	if (errno) {
-		return -1;
-	}
-
-	return fd;
-}
+int android_get_control_socket(const char* name);
 
 /*
  * See also android.os.LocalSocketAddress.Namespace
diff --git a/libcutils/sockets.cpp b/libcutils/sockets.cpp
index d9ab14611..bba63ac16 100644
--- a/libcutils/sockets.cpp
+++ b/libcutils/sockets.cpp
@@ -45,3 +45,24 @@ int socket_get_local_port(cutils_socket_t sock) {
     }
     return -1;
 }
+
+int android_get_control_socket(const char* name) {
+    char key[64];
+    snprintf(key, sizeof(key), ANDROID_SOCKET_ENV_PREFIX "%s", name);
+
+    const char* val = getenv(key);
+    if (!val) {
+        return -1;
+    }
+
+    errno = 0;
+    long ret = strtol(val, NULL, 10);
+    if (errno) {
+        return -1;
+    }
+    if (ret < 0 || ret > INT_MAX) {
+        return -1;
+    }
+
+    return static_cast<int>(ret);
+}
diff --git a/lmkd/Android.mk b/lmkd/Android.mk
index 8c886613d..8980d1c84 100644
--- a/lmkd/Android.mk
+++ b/lmkd/Android.mk
@@ -2,7 +2,7 @@ LOCAL_PATH:= $(call my-dir)
 include $(CLEAR_VARS)
 
 LOCAL_SRC_FILES := lmkd.c
-LOCAL_SHARED_LIBRARIES := liblog libm libc libprocessgroup
+LOCAL_SHARED_LIBRARIES := liblog libm libc libprocessgroup libcutils
 LOCAL_CFLAGS := -Werror
 
 LOCAL_MODULE := lmkd