[NaCl SDK] nacl_io: Auto-bind UDP socket on first sendto().

native_client_sdk/src/tests/nacl_io_socket_test/socket_test.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <arpa/inet.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <netinet/in.h>
 #include <pthread.h>
 #include <sys/types.h>
@@ skipping 226 matching lines @@
   int len2 =
     recvfrom(sock2_, inbuf, sizeof(inbuf), 0, (sockaddr*) &addr, &addrlen);
   EXPECT_EQ(sizeof(outbuf), len2);
   EXPECT_EQ(sizeof(sockaddr_in), addrlen);
   EXPECT_EQ(PORT1, htons(addr.sin_port));
 
   // Now they should be the same
   EXPECT_EQ(0, memcmp(outbuf, inbuf, sizeof(outbuf)));
 }
 
+TEST_F(SocketTestUDP, SendRcvUnbound) {
+  char outbuf[256];
+  char inbuf[512];
+
+  memset(outbuf, 1, sizeof(outbuf));
+  memset(inbuf, 0, sizeof(inbuf));
+
+  // Don't bind sock1_, this will automatically bind sock1_ to a random port
+  // at the time of the first send.
+  EXPECT_EQ(0, Bind(sock2_, LOCAL_HOST, PORT2));
+
+  sockaddr_in addr;
+  sockaddr_in addr2;
+  socklen_t addrlen = sizeof(addr2);
+  IP4ToSockAddr(LOCAL_HOST, PORT2, &addr2);
+
+  // The first send hasn't occurred, so the socket is not yet bound.
+  socklen_t out_addrlen = sizeof(addr);
+  ASSERT_EQ(0, getsockname(sock1_, (sockaddr*)&addr, &out_addrlen));
+  EXPECT_EQ(addrlen, out_addrlen);
+  EXPECT_EQ(0, htonl(addr.sin_addr.s_addr));
+  EXPECT_EQ(0, htons(addr.sin_port));
+
+  int len1 =
+     sendto(sock1_, outbuf, sizeof(outbuf), 0, (sockaddr*) &addr2, addrlen);
+  EXPECT_EQ(sizeof(outbuf), len1);
+
+  // After the first send, the socket should be bound; the port is set, but
+  // the address is still 0.
+  ASSERT_EQ(0, getsockname(sock1_, (sockaddr*)&addr, &out_addrlen));
+  EXPECT_EQ(addrlen, out_addrlen);
+  EXPECT_EQ(0, htonl(addr.sin_addr.s_addr));
+  EXPECT_NE(0, htons(addr.sin_port));
+
+  // Ensure the buffers are different
+  EXPECT_NE(0, memcmp(outbuf, inbuf, sizeof(outbuf)));
+
+  // Try to receive the previously sent packet
+  int len2 =
+    recvfrom(sock2_, inbuf, sizeof(inbuf), 0, (sockaddr*) &addr, &addrlen);
+  EXPECT_EQ(sizeof(outbuf), len2);
+  EXPECT_EQ(sizeof(sockaddr_in), addrlen);
+  EXPECT_EQ(LOCAL_HOST, htonl(addr.sin_addr.s_addr));
+  EXPECT_NE(0, htons(addr.sin_port));
+
+  // Now they should be the same
+  EXPECT_EQ(0, memcmp(outbuf, inbuf, sizeof(outbuf)));
+}
+
 const size_t kQueueSize = 65536 * 8;
 TEST_F(SocketTestUDP, FullFifo) {
   char outbuf[16 * 1024];
 
   ASSERT_EQ(0, Bind(sock1_, LOCAL_HOST, PORT1));
   ASSERT_EQ(0, Bind(sock2_, LOCAL_HOST, PORT2));
 
   sockaddr_in addr;
   socklen_t addrlen = sizeof(addr);
   IP4ToSockAddr(LOCAL_HOST, PORT2, &addr);
@@ skipping 468 matching lines @@
   while (remainder > 0) {
     int rtn = recv(new_sock, buffer, remainder, 0);
     ASSERT_GT(rtn, 0);
     remainder -= rtn;
   }
 
   ASSERT_EQ(0, close(new_sock));
 }
 
 #endif  // PROVIDES_SOCKET_API