From bee5515e9a8e2dc1401b911908d02f54291907ac Mon Sep 17 00:00:00 2001
From: Dirk Ziegelmeier <dirk@ziegelmeier.net>
Date: Thu, 3 Mar 2016 22:52:04 +0100
Subject: [PATCH] netconn API: Reimplement dual-stack API to be socket-like.

When IPv6 ANY address is used and the NETCONN_FLAG_IPV6_V6ONLY is NOT set, bind/listen on/to IP_ANY_TYPE
---
 src/api/api_msg.c      | 47 ++++++++++++++++++++++++++++--------------
 src/include/lwip/api.h | 12 ++---------
 2 files changed, 33 insertions(+), 26 deletions(-)

diff --git a/src/api/api_msg.c b/src/api/api_msg.c
index a4b78b2a..f12c0059 100644
--- a/src/api/api_msg.c
+++ b/src/api/api_msg.c
@@ -523,11 +523,7 @@ pcb_new(struct api_msg_msg *msg)
 #endif /* LWIP_RAW */
 #if LWIP_UDP
   case NETCONN_UDP:
-    if(NETCONNTYPE_ANYIP(msg->conn->type)) {
-      msg->conn->pcb.udp = udp_new_ip_type(IPADDR_TYPE_ANY);  
-    } else {
-      msg->conn->pcb.udp = udp_new();
-    }
+    msg->conn->pcb.udp = udp_new();
     if (msg->conn->pcb.udp != NULL) {
 #if LWIP_UDPLITE
       if (NETCONNTYPE_ISUDPLITE(msg->conn->type)) {
@@ -543,11 +539,7 @@ pcb_new(struct api_msg_msg *msg)
 #endif /* LWIP_UDP */
 #if LWIP_TCP
   case NETCONN_TCP:
-    if(NETCONNTYPE_ANYIP(msg->conn->type)) {
-      msg->conn->pcb.tcp = tcp_new_ip_type(IPADDR_TYPE_ANY);
-    } else {
-      msg->conn->pcb.tcp = tcp_new();
-    }
+    msg->conn->pcb.tcp = tcp_new();
     if (msg->conn->pcb.tcp != NULL) {
       setup_tcp(msg->conn);
     }
@@ -564,7 +556,8 @@ pcb_new(struct api_msg_msg *msg)
 #if LWIP_IPV4 && LWIP_IPV6
   else {
     if (NETCONNTYPE_ISIPV6(msg->conn->type)) {
-      IP_SET_TYPE_VAL(msg->conn->pcb.ip->local_ip, IPADDR_TYPE_V6);
+      /* Convert IPv4 PCB manually to an IPv6 PCB */
+      IP_SET_TYPE_VAL(msg->conn->pcb.ip->local_ip,  IPADDR_TYPE_V6);
       IP_SET_TYPE_VAL(msg->conn->pcb.ip->remote_ip, IPADDR_TYPE_V6);
     }
   }
@@ -1087,20 +1080,37 @@ lwip_netconn_do_bind(struct api_msg_msg *msg)
   } else {
     msg->err = ERR_VAL;
     if (msg->conn->pcb.tcp != NULL) {
+      const ip_addr_t *ipaddr = API_EXPR_REF(msg->msg.bc.ipaddr);
+
+#if LWIP_IPV4 && LWIP_IPV6
+      /* "Socket API like" dual-stack support: If IP to bind to is IP6_ADDR_ANY,
+       * and NETCONN_FLAG_IPV6_V6ONLY is NOT set, use IP_ANY_TYPE to bind
+       */
+      if (ip_addr_cmp(ipaddr, IP6_ADDR_ANY) &&
+          ((msg->conn->flags & NETCONN_FLAG_IPV6_V6ONLY) == 0)) {
+        /* change PCB type to IPADDR_TYPE_ANY */
+        IP_SET_TYPE_VAL(msg->conn->pcb.ip->local_ip,  IPADDR_TYPE_ANY);
+        IP_SET_TYPE_VAL(msg->conn->pcb.ip->remote_ip, IPADDR_TYPE_ANY);
+        
+        /* bind to IPADDR_TYPE_ANY */
+        ipaddr = IP_ANY_TYPE;
+      }
+#endif /* LWIP_IPV4 && LWIP_IPV6 */
+
       switch (NETCONNTYPE_GROUP(msg->conn->type)) {
 #if LWIP_RAW
       case NETCONN_RAW:
-        msg->err = raw_bind(msg->conn->pcb.raw, API_EXPR_REF(msg->msg.bc.ipaddr));
+        msg->err = raw_bind(msg->conn->pcb.raw, ipaddr);
         break;
 #endif /* LWIP_RAW */
 #if LWIP_UDP
       case NETCONN_UDP:
-        msg->err = udp_bind(msg->conn->pcb.udp, API_EXPR_REF(msg->msg.bc.ipaddr), msg->msg.bc.port);
+        msg->err = udp_bind(msg->conn->pcb.udp, ipaddr, msg->msg.bc.port);
         break;
 #endif /* LWIP_UDP */
 #if LWIP_TCP
       case NETCONN_TCP:
-        msg->err = tcp_bind(msg->conn->pcb.tcp, API_EXPR_REF(msg->msg.bc.ipaddr), msg->msg.bc.port);
+        msg->err = tcp_bind(msg->conn->pcb.tcp, ipaddr, msg->msg.bc.port);
         break;
 #endif /* LWIP_TCP */
       default:
@@ -1275,9 +1285,14 @@ lwip_netconn_do_listen(struct api_msg_msg *msg)
             msg->err = ERR_VAL;
           } else {
 #if LWIP_IPV4 && LWIP_IPV6
-            if (ip_addr_isany_val(msg->conn->pcb.tcp->local_ip) &&
+            /* "Socket API like" dual-stack support: If IP to listen to is IP6_ADDR_ANY,
+             * and NETCONN_FLAG_IPV6_V6ONLY is NOT set, use IP_ANY_TYPE to listen
+             */
+            if (ip_addr_cmp(API_EXPR_REF(msg->msg.bc.ipaddr), IP6_ADDR_ANY) &&
                 ((msg->conn->flags & NETCONN_FLAG_IPV6_V6ONLY) == 0)) {
-              IP_SET_TYPE_VAL(msg->conn->pcb.tcp->local_ip, IPADDR_TYPE_ANY);
+              /* change PCB type to IPADDR_TYPE_ANY */
+              IP_SET_TYPE_VAL(msg->conn->pcb.tcp->local_ip,  IPADDR_TYPE_ANY);
+              IP_SET_TYPE_VAL(msg->conn->pcb.tcp->remote_ip, IPADDR_TYPE_ANY);
             }
 #endif /* LWIP_IPV4 && LWIP_IPV6 */
 
diff --git a/src/include/lwip/api.h b/src/include/lwip/api.h
index 33c36e04..9ef9e78a 100644
--- a/src/include/lwip/api.h
+++ b/src/include/lwip/api.h
@@ -79,9 +79,6 @@ extern "C" {
 #endif /* LWIP_IPV6 */
 
 
-#define NETCONN_TYPE_IP_ANY          0x04
-#define NETCONNTYPE_ANYIP(t)         (((t)&NETCONN_TYPE_IP_ANY) != 0)
-
     /* Helpers to process several netconn_types by the same code */
 #define NETCONNTYPE_GROUP(t)         ((t)&0xF0)
 #define NETCONNTYPE_DATAGRAM(t)      ((t)&0xE0)
@@ -115,15 +112,10 @@ enum netconn_type {
 #endif /* LWIP_IPV6 */
 
   /* NETCONN_RAW Group */
-  NETCONN_RAW         = 0x40,
+  NETCONN_RAW         = 0x40
 #if LWIP_IPV6
-  NETCONN_RAW_IPV6    = NETCONN_RAW | NETCONN_TYPE_IPV6, /* 0x48 */
+  , NETCONN_RAW_IPV6    = NETCONN_RAW | NETCONN_TYPE_IPV6 /* 0x48 */
 #endif /* LWIP_IPV6 */
-
-  /* NETCONN dual stack */
-  NETCONN_TCP_IPANY     = NETCONN_TCP | NETCONN_TYPE_IP_ANY, /* 0x14 */
-  NETCONN_UDP_IPANY     = NETCONN_UDP | NETCONN_TYPE_IP_ANY  /* 0x24 */
-/*  NETCONN_RAW_IPANY     = NETCONN_RAW | NETCONN_TYPE_IP_ANY, */ /* 0x44 */
 };
 
 /** Current state of the netconn. Non-TCP netconns are always