Export maximum number of fds/ints in a native_handle.

So we can deserialize it consisently and safely.

Bug: 120084106
Test: builds
Change-Id: I0eafff70d3a7e4d732fe600a0052efb90108208d

libcutils/include/cutils/native_handle.h

diff --git a/libcutils/include/cutils/native_handle.h b/libcutils/include/cutils/native_handle.h
index 10f5bc0..f6cae36 100644
--- a/libcutils/include/cutils/native_handle.h
+++ b/libcutils/include/cutils/native_handle.h
@@ -23,6 +23,9 @@
 extern "C" {
 #endif
 
+#define NATIVE_HANDLE_MAX_FDS 1024
+#define NATIVE_HANDLE_MAX_INTS 1024
+
 /* Declare a char array for use with native_handle_init */
 #define NATIVE_HANDLE_DECLARE_STORAGE(name, maxFds, maxInts) \
     alignas(native_handle_t) char (name)[                            \

libcutils/native_handle.cpp

diff --git a/libcutils/native_handle.cpp b/libcutils/native_handle.cpp
index 66f7a3d..b409e5b 100644
--- a/libcutils/native_handle.cpp
+++ b/libcutils/native_handle.cpp
@@ -22,9 +22,6 @@
 #include <string.h>
 #include <unistd.h>
 
-static const int kMaxNativeFds = 1024;
-static const int kMaxNativeInts = 1024;
-
 native_handle_t* native_handle_init(char* storage, int numFds, int numInts) {
     if ((uintptr_t) storage % alignof(native_handle_t)) {
         errno = EINVAL;
@@ -39,7 +36,8 @@
 }
 
 native_handle_t* native_handle_create(int numFds, int numInts) {
-    if (numFds < 0 || numInts < 0 || numFds > kMaxNativeFds || numInts > kMaxNativeInts) {
+    if (numFds < 0 || numInts < 0 || numFds > NATIVE_HANDLE_MAX_FDS ||
+        numInts > NATIVE_HANDLE_MAX_INTS) {
         errno = EINVAL;
         return NULL;
     }