Network: add support for simultaneous outgoing connections via different network interface (#87)

Author: furbanc

Components/Network/Include/rl_net.h

@@ -1,6 +1,6 @@
 /*------------------------------------------------------------------------------
  * MDK Middleware - Component ::Network
- * Copyright (c) 2004-2024 Arm Limited (or its affiliates). All rights reserved.
+ * Copyright (c) 2004-2025 Arm Limited (or its affiliates). All rights reserved.
  *------------------------------------------------------------------------------
  * Name:    rl_net.h
  * Purpose: Network API
@@ -17,7 +17,7 @@
 
 /// Network component version
 #define MW_NET_VERSION_MAJOR    8
-#define MW_NET_VERSION_MINOR    0
+#define MW_NET_VERSION_MINOR    1
 #define MW_NET_VERSION_PATCH    0
 
 #ifdef __cplusplus
@@ -136,6 +136,7 @@ typedef enum {
 typedef enum {
   netTCP_OptionTOS            = 0,      ///< IPv4 Type of Service; val=TOS
   netTCP_OptionTrafficClass,            ///< IPv6 Traffic Class; val=TrafficClass
+  netTCP_OptionInterface,               ///< Network interface to bind; val=if_id (class and number)
   netTCP_OptionTimeout,                 ///< TCP Idle Timeout; val=timeout (in seconds)
   netTCP_OptionKeepAlive,               ///< TCP Keep Alive; val: 0=disabled (default), 1=enabled
   netTCP_OptionFlowControl,             ///< TCP Flow Control; val: 0=disabled (default), 1=enabled

Components/Network/Network.scvd

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 
 <component_viewer schemaVersion="0.1" xmlns:xs="http://www.w3.org/2001/XMLSchema-instance" xs:noNamespaceSchemaLocation="Component_Viewer.xsd">
-  <component name="Network" shortname="NET" version="8.0.1"/>    <!-- name and version of the component  -->
+  <component name="Network" shortname="NET" version="8.1.0"/>    <!-- name and version of the component  -->
 
   <typedefs>
     <!-- Network Library variant -->
@@ -745,7 +745,7 @@
         <enum name="TTL"             value="1"         info="IPv4 Multi-cast Time to Live"/>
         <enum name="TrafficClass"    value="2"         info="IPv6 Traffic Class"/>
         <enum name="HopLimit"        value="3"         info="IPv6 Multi-cast Hop limit"/>
-        <enum name="Interface"       value="4"         info="Broadcast Network interface"/>
+        <enum name="Interface"       value="4"         info="Bound Network interface"/>
         <enum name="Checksum"        value="5"         info="Checksum Options"/>
       </member>
     </typedef>
@@ -808,10 +808,11 @@
       <member name="id"            type="uint8_t"    offset="0">
         <enum name="TOS"             value="0"         info="IPv4 Type of Service"/>
         <enum name="TrafficClass"    value="1"         info="IPv6 Traffic Class"/>
-        <enum name="Timeout"         value="2"         info="TCP Idle Timeout"/>
-        <enum name="KeepAlive"       value="3"         info="TCP Keep Alive"/>
-        <enum name="FlowControl"     value="4"         info="TCP Flow Control"/>
-        <enum name="DelayedACK"      value="5"         info="TCP Delayed Acknowledgment"/>
+        <enum name="Interface"       value="2"         info="Bound Network interface"/>
+        <enum name="Timeout"         value="3"         info="TCP Idle Timeout"/>
+        <enum name="KeepAlive"       value="4"         info="TCP Keep Alive"/>
+        <enum name="FlowControl"     value="5"         info="TCP Flow Control"/>
+        <enum name="DelayedACK"      value="6"         info="TCP Delayed Acknowledgment"/>
       </member>
     </typedef>
 
@@ -2110,7 +2111,7 @@
     <event id="19 + 0xD000" level="Detail" property="SetOptionTclass"           value="socket=%d[val1], tclass=%d[val2]" info="Set socket option traffic class for IPv6"/>
     <event id="20 + 0xD000" level="Detail" property="SetOptionHopLimit"         value="socket=%d[val1], hop_limit=%d[val2]" info="Set socket option hop limit for IPv6"/>
     <event id="21 + 0xD000" level="Detail" property="SetOptionChecksum"         value="socket=%d[val1], send=%t[val2 &amp; 1 ? &quot;On&quot; : &quot;Off&quot;], verify=%t[val2 &amp; 2 ? &quot;On&quot; : &quot;Off&quot;]" info="Set socket checksum calculation options"/>
-    <event id="42 + 0xD000" level="Detail" property="SetOptionInterface"        value="socket=%d[val1], netif=%E[val2, NetIf:id]" info="Set Network Interface for broadcasts and multicasts"/>
+    <event id="42 + 0xD000" level="Detail" property="SetOptionInterface"        value="socket=%d[val1], netif=%E[val2, NetIf:id]" info="Set Network Interface for broadcasts, multicasts and internet access"/>
     <event id="22 + 0xD000" level="Error"  property="SetOptionWrongOption"      value="socket=%d[val1], opt=%E[val2, UDP_Opt:id]" info="Invalid option requested"/>
     <event id="23 + 0xD000" level="Error"  property="SetOptionWrongValue"       value="socket=%d[val1], value=%d[val2]" info="Invalid value for option provided"/>
     <event id="24 + 0xD000" level="Error"  property="GetBufferFailed"           value="size=%d[val1]" info="GetBuffer failed, out of memory error"/>
@@ -2189,6 +2190,7 @@
     <event id="50 + 0xD100" level="Detail" property="SetOptionKeepAlive"        value="socket=%d[val1], enable=%d[val2]" info="Set socket option keep-alive"/>
     <event id="51 + 0xD100" level="Detail" property="SetOptionFlowControl"      value="socket=%d[val1], enable=%d[val2]" info="Set socket option flow-control"/>
     <event id="52 + 0xD100" level="Detail" property="SetOptionDelayedAck"       value="socket=%d[val1], enable=%d[val2]" info="Set socket option delayed-acknowledge"/>
+    <event id="116+ 0xD100" level="Detail" property="SetOptionInterface"        value="socket=%d[val1], netif=%E[val2, NetIf:id]" info="Set Network Interface for internet connections"/>
     <event id="53 + 0xD100" level="Error"  property="SetOptionWrongOption"      value="socket=%d[val1], opt=%E[val2, TCP_Opt:id]" info="Invalid option requested"/>
     <event id="54 + 0xD100" level="Error"  property="SetOptionWrongValue"       value="socket=%d[val1], value=%d[val2]" info="Invalid value for option provided"/>
     <event id="55 + 0xD100" level="Op"     property="SendDelayedAck"            value="socket=%d[val1]" info="Send delayed-acknowledge"/>

Components/Network/Source/net_bsd.c

@@ -1,6 +1,6 @@
 /*------------------------------------------------------------------------------
  * MDK Middleware - Component ::Network
- * Copyright (c) 2004-2024 Arm Limited (or its affiliates). All rights reserved.
+ * Copyright (c) 2004-2025 Arm Limited (or its affiliates). All rights reserved.
  *------------------------------------------------------------------------------
  * Name:    net_bsd.c
  * Purpose: Berkeley Socket API
@@ -1793,6 +1793,7 @@ int32_t getsockname (int32_t sock, SOCKADDR *name, int32_t *namelen) {
 int32_t setsockopt (int32_t sock, int32_t level,
                                   int32_t optname, const char *optval, int32_t optlen) {
   NET_BSD_INFO *bsd_s;
+  netStatus retv;
   uint32_t bval;
   uint16_t bval16;
 
@@ -1896,15 +1897,23 @@ not_supp:   ERRORF (BSD,"Setsockopt, Socket %d opt not supported\n",sock);
           break;
 
         case SO_BINDTODEVICE:
-          /* Bind a socket to network interface */
-          if (bsd_s->Type != SOCK_DGRAM) {
-            goto not_supp;
+          /* Bind socket to network interface */
+          if (bsd_s->Type == SOCK_STREAM) {
+            if (bsd_s->State > BSD_STATE_CREATED) {
+              ERRORF (BSD,"Setsockopt, Socket %d already bound\n",sock);
+              EvrNetBSD_SetoptSocketBound (sock);
+              RETURN (BSD_ERROR);
+            }
+            retv = net_tcp_set_option (bsd_s->Socket, netTCP_OptionInterface, bval);
+          }
+          else {
+            retv = net_udp_set_option (bsd_s->Socket, netUDP_OptionInterface, bval);
           }
-          if (net_udp_set_option (bsd_s->Socket, netUDP_OptionInterface, bval) != netOK) {
+          if (retv != netOK) {
             /* Invalid interface id */
             goto inv_arg;
           }
-          DEBUGF (BSD," Bind to %s\n", net_if_map_lan(bval)->Name);
+          DEBUGF (BSD," Bind to %s\n", net_if_map_all(bval)->Name);
           EvrNetBSD_SetoptBindToDevice (sock, bval);
           break;
 
@@ -2116,8 +2125,9 @@ not_supp:   ERRORF (BSD,"Getsockopt, Socket %d opt not supported\n",sock);
 
         case SO_BINDTODEVICE:
           /* Bound network interface */
-          if (bsd_s->Type != SOCK_DGRAM) {
-            goto not_supp;
+          if (bsd_s->Type == SOCK_STREAM) {
+            retv = net_tcp_get_option (bsd_s->Socket, netTCP_OptionInterface);
+            break;
           }
           retv = net_udp_get_option (bsd_s->Socket, netUDP_OptionInterface);
           break;

Components/Network/Source/net_evr.h

@@ -1,6 +1,6 @@
 /*------------------------------------------------------------------------------
  * MDK Middleware - Component ::Network
- * Copyright (c) 2004-2024 Arm Limited (or its affiliates). All rights reserved.
+ * Copyright (c) 2004-2025 Arm Limited (or its affiliates). All rights reserved.
  *------------------------------------------------------------------------------
  * Name:    net_evr.h
  * Purpose: Network definitions for Event Recorder
@@ -9140,7 +9140,7 @@ typedef struct evr_addr {
 #endif
 
 /**
-  \brief  Event on UDP set socket option broadcast interface (Detail)
+  \brief  Event on UDP set socket option bind to interface (Detail)
   \param  socket        socket handle
   \param  if_id         network interface identifier
  */
@@ -9426,7 +9426,7 @@ typedef struct evr_addr {
 #define EvtNetTCP_ConnectLocalPortInvalid   EventID (EventLevelError, EvtNetTCP, 17)
 #define EvtNetTCP_AssignLocalPort           EventID (EventLevelOp,    EvtNetTCP, 18)
 #define EvtNetTCP_ConnectSocketWrongState   EventID (EventLevelError, EvtNetTCP, 19)
-#define EvtNetTCP_ConnectNoRouteFound       EventID (EventLevelError, EvtNetTCP,115) // End
+#define EvtNetTCP_ConnectNoRouteFound       EventID (EventLevelError, EvtNetTCP,115)
 #define EvtNetTCP_ShowRttVariables          EventID (EventLevelDetail,EvtNetTCP, 20)
 #define EvtNetTCP_GetBufferFailed           EventID (EventLevelError, EvtNetTCP, 21)
 #define EvtNetTCP_SendFrame                 EventID (EventLevelOp,    EvtNetTCP, 22)
@@ -9460,6 +9460,7 @@ typedef struct evr_addr {
 #define EvtNetTCP_SetOptionKeepAlive        EventID (EventLevelDetail,EvtNetTCP, 50)
 #define EvtNetTCP_SetOptionFlowControl      EventID (EventLevelDetail,EvtNetTCP, 51)
 #define EvtNetTCP_SetOptionDelayedAck       EventID (EventLevelDetail,EvtNetTCP, 52)
+#define EvtNetTCP_SetOptionInterface        EventID (EventLevelDetail,EvtNetTCP,116) // End
 #define EvtNetTCP_SetOptionWrongOption      EventID (EventLevelError, EvtNetTCP, 53)
 #define EvtNetTCP_SetOptionWrongValue       EventID (EventLevelError, EvtNetTCP, 54)
 #define EvtNetTCP_SendDelayedAck            EventID (EventLevelOp,    EvtNetTCP, 55)
@@ -10139,6 +10140,19 @@ typedef struct evr_addr {
   #define EvrNetTCP_SetOptionTclass(socket, ip6_tclass)
 #endif
 
+/**
+  \brief  Event on TCP set socket option bind to interface (Detail)
+  \param  socket        socket handle
+  \param  if_id         network interface identifier
+ */
+#ifdef Network_Debug_EVR
+  __STATIC_INLINE void EvrNetTCP_SetOptionInterface(int32_t socket, uint16_t if_id) {
+    EventRecord2 (EvtNetTCP_SetOptionInterface, (uint32_t)socket, if_id);
+  }
+#else
+  #define EvrNetTCP_SetOptionInterface(socket, if_id)
+#endif
+
 /**
   \brief  Event on TCP set socket option connection timeout (Detail)
   \param  socket        socket handle

Components/Network/Source/net_ip4.c

@@ -1,6 +1,6 @@
 /*------------------------------------------------------------------------------
  * MDK Middleware - Component ::Network
- * Copyright (c) 2004-2024 Arm Limited (or its affiliates). All rights reserved.
+ * Copyright (c) 2004-2025 Arm Limited (or its affiliates). All rights reserved.
  *------------------------------------------------------------------------------
  * Name:    net_ip4.c
  * Purpose: Internet Protocol Version 4
@@ -483,6 +483,11 @@ NET_IF_CFG *net_ip4_find_route (NET_IF_CFG *net_if, const uint8_t *dst_addr) {
     }
   }
   /* Address is external */
+  if (net_if != NULL) {
+    /* Use desired interface */
+    return (net_if);
+  }
+  /* Use default interface */
   return (ip4->DefNetIf);
 }
 

Components/Network/Source/net_tcp.c

@@ -1,6 +1,6 @@
 /*------------------------------------------------------------------------------
  * MDK Middleware - Component ::Network
- * Copyright (c) 2004-2024 Arm Limited (or its affiliates). All rights reserved.
+ * Copyright (c) 2004-2025 Arm Limited (or its affiliates). All rights reserved.
  *------------------------------------------------------------------------------
  * Name:    net_tcp.c
  * Purpose: Transmission Control Protocol
@@ -276,6 +276,7 @@ netStatus net_tcp_listen (int32_t socket, uint16_t port) {
 */
 netStatus net_tcp_connect (int32_t socket, const __ADDR *addr, uint16_t local_port) {
   NET_TCP_INFO *tcp_s;
+  NET_IF_CFG *out_if;
 
   DEBUGF (TCP,"Connect Socket %d, LocPort %d\n",socket,local_port);
   EvrNetTCP_ConnectSocket (socket, local_port);
@@ -323,14 +324,16 @@ netStatus net_tcp_connect (int32_t socket, const __ADDR *addr, uint16_t local_po
       EvrNetTCP_ConnectSocketWrongState (socket, tcp_s->State);
       return (netWrongState);
   }
-  /* Assign an interface for the connection */
-  tcp_s->net_if = net_addr_find_route (NULL, addr);
-  if (tcp_s->net_if == NULL) {
-    /* No route to destination, also fails for IP6 in IP4_only variant */
+
+  /* Check the interface routing */
+  out_if = net_addr_find_route (tcp_s->net_if, addr);
+  if (!out_if || (tcp_s->net_if && (out_if != tcp_s->net_if))) {
+    /* No route or the route differs from the requested */
     ERRORF (TCP,"Connect, Socket %d no route found\n",socket);
     EvrNetTCP_ConnectNoRouteFound (socket);
     return (netError);
   }
+  tcp_s->net_if = out_if;
 
   /* Socket mode is Client now */
   tcp_s->Type      &= ~TCP_TYPE_SERVER;
@@ -885,6 +888,7 @@ netStatus net_tcp_reset_window (int32_t socket) {
 */
 netStatus net_tcp_set_option (int32_t socket, netTCP_Option option, uint32_t val) {
   NET_TCP_INFO *tcp_s;
+  NET_IF_CFG *net_if;
 
   DEBUGF (TCP,"SetOption Socket %d\n",socket);
   EvrNetTCP_SetOptionSocket (socket, option, val);
@@ -895,6 +899,7 @@ netStatus net_tcp_set_option (int32_t socket, netTCP_Option option, uint32_t val
   }
   tcp_s = &tcp->Scb[socket-1];
   if (tcp_s->State == netTCP_StateUNUSED) {
+wrong_state:
     ERRORF (TCP,"SetOption, Socket %d wrong state\n",socket);
     EvrNetTCP_SetOptionSocketWrongState (socket, tcp_s->State);
     return (netWrongState);
@@ -916,6 +921,17 @@ netStatus net_tcp_set_option (int32_t socket, netTCP_Option option, uint32_t val
       return (netOK);
 #endif
 
+    case netTCP_OptionInterface:
+      if (tcp_s->State != netTCP_StateCLOSED) {
+        goto wrong_state;
+      }
+      net_if = net_if_map_all (val);
+      if (net_if == NULL) break;
+      DEBUGF (TCP," Interface=%s\n",net_if->Name);
+      EvrNetTCP_SetOptionInterface (socket, net_if->Id);
+      tcp_s->net_if = net_if;
+      return (netOK);
+
     case netTCP_OptionTimeout:
       if (val > 65535) break;
       if (val == 0) {
@@ -992,6 +1008,13 @@ uint32_t net_tcp_get_option (int32_t socket, netTCP_Option option) {
       return (tcp_s->TClass);
 #endif
 
+    case netTCP_OptionInterface:
+      if (!tcp_s->net_if) {
+        /* Network interface not assigned */
+        return (0);
+      }
+      return (tcp_s->net_if->Id);
+
     case netTCP_OptionTimeout:
       return (tcp_s->ConnTout);
 

Components/Network/Source/net_udp.c

@@ -1,6 +1,6 @@
 /*------------------------------------------------------------------------------
  * MDK Middleware - Component ::Network
- * Copyright (c) 2004-2024 Arm Limited (or its affiliates). All rights reserved.
+ * Copyright (c) 2004-2025 Arm Limited (or its affiliates). All rights reserved.
  *------------------------------------------------------------------------------
  * Name:    net_udp.c
  * Purpose: User Datagram Protocol
@@ -278,7 +278,7 @@ netStatus net_udp_set_option (int32_t socket, netUDP_Option option, uint32_t val
 #endif
 
     case netUDP_OptionInterface:
-      net_if = net_if_map_lan (val);
+      net_if = net_if_map_all (val);
       if (net_if == NULL) break;
       DEBUGF (UDP," Interface=%s\n",net_if->Name);
       EvrNetUDP_SetOptionInterface (socket, net_if->Id);

Documentation/Doxygen/General/src/revision_history.md

@@ -12,7 +12,7 @@
   <tr>
     <td>V8.0.1-dev</td>
     <td>
-      - Network Component Version 8.0.1
+      - Network Component Version 8.1.0
       - FileSystem Component Version 8.0.1
     </td>
   </tr>

Documentation/Doxygen/Network/src/net_evr.txt

@@ -7190,7 +7190,7 @@ This usually happens when the \ref netUDP_SetOption function is executed.
 \details
 The event \b SetOptionInterface is created, when the internal function \e udp_set_option
 sets the network interface for the socket that is used when the \ref netUDP_Send sends data
-to a broadcast or a multicast address. This usually happens when the \ref netUDP_SetOption
+to a broadcast, multicast or external address. This usually happens when the \ref netUDP_SetOption
 function is executed.
 
 \b Value in the Event Recorder shows:
@@ -8032,6 +8032,18 @@ when the \ref netTCP_SetOption function is executed.
   - \b enable: controlling the delayed acknowledgement (1= enable, 0= disable).
 */
 
+/**
+\fn __STATIC_INLINE void EvrNetTCP_SetOptionInterface(int32_t socket, uint16_t if_id)
+\details
+The event \b SetOptionInterface is created, when the internal function \e tcp_set_option
+sets the network interface for the socket used to connect to an external address.
+This usually happens when the \ref netTCP_SetOption function is executed.
+
+\b Value in the Event Recorder shows:
+  - \b socket: TCP socket handle for setting the option.
+  - \b netif:  network interface identifier.
+*/
+
 /**
 \fn __STATIC_INLINE void EvrNetTCP_SetOptionWrongOption(int32_t socket, int32_t tcp_option)
 \details
@@ -8830,8 +8842,8 @@ the required socket is not created. This happens when the \ref bind function is
 \fn __STATIC_INLINE void EvrNetBSD_BindSocketAlreadyBound(int32_t sock)
 \details
 The event \b BindSocketAlreadyBound is created when the BSD socket can not bind,
-because the required socket is bound already. This happens when the \ref bind function
-is executed.
+because the required socket is bound already. This happens when the \ref bind or
+\ref setsockopt function is executed.
 
 \b Value in the Event Recorder shows:
   - \b sock: BSD socket descriptor for binding.

Documentation/Doxygen/Network/src/revision_history.md

@@ -6,8 +6,9 @@
       <th>Description</th>
     </tr>
     <tr>
-      <td>V8.0.1</td>
+      <td>V8.1.0</td>
       <td>
+        - added support for simultaneous outgoing connections via different network interfaces
         - fixed handling of Ethernet drivers not supporting multicast address filtering
       </td>
     </tr>