[cli] fix udp example (#2084)

src/cli/README_UDP.md

@@ -33,7 +33,7 @@ On node 2, open the example UDP socket and send a simple message.
 On node 1, you should see a print out similar to below:
 
 ```bash
-5 bytes from fdde:ad00:beef:0:dac3:6792:e2e:90d8: hello
+5 bytes from fdde:ad00:beef:0:dac3:6792:e2e:90d8 49153 hello
 ```
 
 ## Command List

src/cli/cli_udp_example.cpp

@@ -74,14 +74,14 @@ otError Udp::ProcessBind(int argc, char *argv[])
     otSockAddr sockaddr;
     long value;
 
-    memset(&sockaddr, 0, sizeof(sockaddr));
-
     VerifyOrExit(argc == 2, error = OT_ERROR_PARSE);
 
-    error = otIp6AddressFromString(argv[1], &sockaddr.mAddress);
+    memset(&sockaddr, 0, sizeof(sockaddr));
+
+    error = otIp6AddressFromString(argv[0], &sockaddr.mAddress);
     SuccessOrExit(error);
 
-    error = Interpreter::ParseLong(argv[2], value);
+    error = Interpreter::ParseLong(argv[1], value);
     SuccessOrExit(error);
 
     sockaddr.mPort = static_cast<uint16_t>(value);
@@ -98,14 +98,14 @@ otError Udp::ProcessConnect(int argc, char *argv[])
     otSockAddr sockaddr;
     long value;
 
-    memset(&sockaddr, 0, sizeof(sockaddr));
-
     VerifyOrExit(argc == 2, error = OT_ERROR_PARSE);
 
-    error = otIp6AddressFromString(argv[1], &sockaddr.mAddress);
+    memset(&sockaddr, 0, sizeof(sockaddr));
+
+    error = otIp6AddressFromString(argv[0], &sockaddr.mAddress);
     SuccessOrExit(error);
 
-    error = Interpreter::ParseLong(argv[2], value);
+    error = Interpreter::ParseLong(argv[1], value);
     SuccessOrExit(error);
 
     sockaddr.mPort = static_cast<uint16_t>(value);
@@ -137,7 +137,7 @@ otError Udp::ProcessSend(int argc, char *argv[])
     otError error;
     otMessageInfo messageInfo;
     otMessage *message = NULL;
-    int curArg = 1;
+    int curArg = 0;
 
     memset(&messageInfo, 0, sizeof(messageInfo));
 
@@ -159,7 +159,7 @@ otError Udp::ProcessSend(int argc, char *argv[])
     message = otUdpNewMessage(mInterpreter.mInstance, true);
     VerifyOrExit(message != NULL, error = OT_ERROR_NO_BUFS);
 
-    error = otMessageAppend(message, argv[curArg], static_cast<uint16_t>(strlen(argv[3])));
+    error = otMessageAppend(message, argv[curArg], static_cast<uint16_t>(strlen(argv[curArg])));
     SuccessOrExit(error);
 
     error = otUdpSend(&mSocket, message, &messageInfo);
@@ -176,20 +176,17 @@ exit:
 
 otError Udp::Process(int argc, char *argv[])
 {
-    otError error = OT_ERROR_NONE;
+    otError error = OT_ERROR_PARSE;
 
     for (size_t i = 0; i < sizeof(sCommands) / sizeof(sCommands[0]); i++)
     {
         if (strcmp(argv[0], sCommands[i].mName) == 0)
         {
-            (this->*sCommands[i].mCommand)(argc, argv);
-            ExitNow();
+            error = (this->*sCommands[i].mCommand)(argc - 1, argv + 1);
+            break;
         }
     }
 
-    error = OT_ERROR_PARSE;
-
-exit:
     return error;
 }
 
@@ -204,7 +201,7 @@ void Udp::HandleUdpReceive(otMessage *aMessage, const otMessageInfo *aMessageInf
     int length;
 
     mInterpreter.mServer->OutputFormat("%d bytes from ", otMessageGetLength(aMessage) - otMessageGetOffset(aMessage));
-    mInterpreter.mServer->OutputFormat("%x:%x:%x:%x:%x:%x:%x:%x: ",
+    mInterpreter.mServer->OutputFormat("%x:%x:%x:%x:%x:%x:%x:%x %d ",
                                        HostSwap16(aMessageInfo->mPeerAddr.mFields.m16[0]),
                                        HostSwap16(aMessageInfo->mPeerAddr.mFields.m16[1]),
                                        HostSwap16(aMessageInfo->mPeerAddr.mFields.m16[2]),
@@ -212,7 +209,8 @@ void Udp::HandleUdpReceive(otMessage *aMessage, const otMessageInfo *aMessageInf
                                        HostSwap16(aMessageInfo->mPeerAddr.mFields.m16[4]),
                                        HostSwap16(aMessageInfo->mPeerAddr.mFields.m16[5]),
                                        HostSwap16(aMessageInfo->mPeerAddr.mFields.m16[6]),
-                                       HostSwap16(aMessageInfo->mPeerAddr.mFields.m16[7]));
+                                       HostSwap16(aMessageInfo->mPeerAddr.mFields.m16[7]),
+                                       aMessageInfo->mPeerPort);
 
     length = otMessageRead(aMessage, otMessageGetOffset(aMessage), buf, sizeof(buf) - 1);
     buf[length] = '\0';

src/core/net/udp6.cpp

@@ -114,6 +114,19 @@ otError UdpSocket::SendTo(Message &aMessage, const MessageInfo &aMessageInfo)
         GetSockName().mPort = static_cast<Udp *>(mTransport)->GetEphemeralPort();
     }
 
+    if (messageInfoLocal.GetPeerAddr().IsUnspecified())
+    {
+        VerifyOrExit(!GetPeerName().GetAddress().IsUnspecified(), error = OT_ERROR_INVALID_ARGS);
+
+        messageInfoLocal.SetPeerAddr(GetPeerName().GetAddress());
+    }
+
+    if (messageInfoLocal.mPeerPort == 0)
+    {
+        VerifyOrExit(GetPeerName().mPort != 0, error = OT_ERROR_INVALID_ARGS);
+        messageInfoLocal.mPeerPort = GetPeerName().mPort;
+    }
+
     udpHeader.SetSourcePort(GetSockName().mPort);
     udpHeader.SetDestinationPort(messageInfoLocal.mPeerPort);
     udpHeader.SetLength(sizeof(udpHeader) + aMessage.GetLength());

src/core/net/udp6.hpp

@@ -126,8 +126,9 @@ public:
      * @param[in]  aMessage      The message to send.
      * @param[in]  aMessageInfo  The message info associated with @p aMessage.
      *
-     * @retval OT_ERROR_NONE     Successfully sent the UDP message.
-     * @retval OT_ERROR_NO_BUFS  Insufficient available buffer to add the UDP and IPv6 headers.
+     * @retval OT_ERROR_NONE          Successfully sent the UDP message.
+     * @retval OT_ERROR_INVALID_ARGS  If no peer is specified in @p aMessageInfo or by connect().
+     * @retval OT_ERROR_NO_BUFS       Insufficient available buffer to add the UDP and IPv6 headers.
      *
      */
     otError SendTo(Message &aMessage, const MessageInfo &aMessageInfo);