Log socket error code on failure

Issue #643.

Change-Id: I8adfb9910e1e43294738abb7783a64645a4f42c3

packager/file/udp_file.cc

@@ -11,6 +11,7 @@
 #include <windows.h>
 #include <ws2tcpip.h>
 #define close closesocket
+#define EINTR_CODE WSAEINTR
 
 #else
 
@@ -21,6 +22,7 @@
 #include <sys/time.h>
 #include <unistd.h>
 #define INVALID_SOCKET -1
+#define EINTR_CODE EINTR
 
 // IP_MULTICAST_ALL has been supported since kernel version 2.6.31 but we may be
 // building on a machine that is older than that.
@@ -43,6 +45,14 @@ bool IsIpv4MulticastAddress(const struct in_addr& addr) {
   return (ntohl(addr.s_addr) & 0xf0000000) == 0xe0000000;
 }
 
+int GetSocketErrorCode() {
+#if defined(OS_WIN)
+  return WSAGetLastError();
+#else
+  return errno;
+#endif
+}
+
 }  // anonymous namespace
 
 UdpFile::UdpFile(const char* file_name)
@@ -71,7 +81,7 @@ int64_t UdpFile::Read(void* buffer, uint64_t length) {
   do {
     result =
         recvfrom(socket_, reinterpret_cast<char*>(buffer), length, 0, NULL, 0);
-  } while ((result == -1) && (errno == EINTR));
+  } while (result == -1 && GetSocketErrorCode() == EINTR_CODE);
 
   return result;
 }
@@ -165,7 +175,7 @@ bool UdpFile::Open() {
 
   ScopedSocket new_socket(socket(AF_INET, SOCK_DGRAM, 0));
   if (new_socket.get() == INVALID_SOCKET) {
-    LOG(ERROR) << "Could not allocate socket.";
+    LOG(ERROR) << "Could not allocate socket, error = " << GetSocketErrorCode();
     return false;
   }
 
@@ -191,8 +201,9 @@ bool UdpFile::Open() {
     if (setsockopt(new_socket.get(), SOL_SOCKET, SO_REUSEADDR,
                    reinterpret_cast<const char*>(&optval),
                    sizeof(optval)) < 0) {
-      LOG(ERROR)
+      LOG(ERROR) << "Could not apply the SO_REUSEADDR property to the UDP "
-          << "Could not apply the SO_REUSEADDR property to the UDP socket";
+                    "socket, error = "
+                 << GetSocketErrorCode();
       return false;
     }
   }
@@ -200,7 +211,7 @@ bool UdpFile::Open() {
   if (bind(new_socket.get(),
            reinterpret_cast<struct sockaddr*>(&local_sock_addr),
            sizeof(local_sock_addr)) < 0) {
-    LOG(ERROR) << "Could not bind UDP socket";
+    LOG(ERROR) << "Could not bind UDP socket, error = " << GetSocketErrorCode();
     return false;
   }
 
@@ -229,8 +240,9 @@ bool UdpFile::Open() {
                      IP_ADD_SOURCE_MEMBERSHIP,
                      reinterpret_cast<const char*>(&source_multicast_group),
                      sizeof(source_multicast_group)) < 0) {
-          LOG(ERROR) << "Failed to join multicast group.";
+        LOG(ERROR) << "Failed to join multicast group, error = "
-          return false;
+                   << GetSocketErrorCode();
+        return false;
       }
     } else {
       // this is a v2 join without a specific source.
@@ -246,12 +258,12 @@ bool UdpFile::Open() {
       }
 
       if (setsockopt(new_socket.get(), IPPROTO_IP, IP_ADD_MEMBERSHIP,
-                    reinterpret_cast<const char*>(&multicast_group),
+                     reinterpret_cast<const char*>(&multicast_group),
-                    sizeof(multicast_group)) < 0) {
+                     sizeof(multicast_group)) < 0) {
-        LOG(ERROR) << "Failed to join multicast group.";
+        LOG(ERROR) << "Failed to join multicast group, error = "
+                   << GetSocketErrorCode();
         return false;
       }
-
   }
 
 #if defined(__linux__)
@@ -261,8 +273,9 @@ bool UdpFile::Open() {
     if (setsockopt(new_socket.get(), IPPROTO_IP, IP_MULTICAST_ALL,
                    reinterpret_cast<const char*>(&optval_zero),
                    sizeof(optval_zero)) < 0 &&
-        errno != ENOPROTOOPT) {
+        GetSocketErrorCode() != ENOPROTOOPT) {
-      LOG(ERROR) << "Failed to disable IP_MULTICAST_ALL option.";
+      LOG(ERROR) << "Failed to disable IP_MULTICAST_ALL option, error = "
+                 << GetSocketErrorCode();
       return false;
     }
 #endif  // #if defined(__linux__)
@@ -275,7 +288,8 @@ bool UdpFile::Open() {
     tv.tv_usec = options->timeout_us() % 1000000;
     if (setsockopt(new_socket.get(), SOL_SOCKET, SO_RCVTIMEO,
                    reinterpret_cast<const char*>(&tv), sizeof(tv)) < 0) {
-      LOG(ERROR) << "Failed to set socket timeout.";
+      LOG(ERROR) << "Failed to set socket timeout, error = "
+                 << GetSocketErrorCode();
       return false;
     }
   }
@@ -285,8 +299,8 @@ bool UdpFile::Open() {
     if (setsockopt(new_socket.get(), SOL_SOCKET, SO_RCVBUF,
                    reinterpret_cast<const char*>(&receive_buffer_size),
                    sizeof(receive_buffer_size)) < 0) {
-      LOG(ERROR) << "Failed to set the maximum receive buffer size: "
+      LOG(ERROR) << "Failed to set the maximum receive buffer size, error = "
-                 << strerror(errno);
+                 << GetSocketErrorCode();
       return false;
     }
   }