From f9ce31f98bf3718f75e6857c34482a074478bf4a Mon Sep 17 00:00:00 2001
From: Dirk Ziegelmeier <dirk@ziegelmeier.net>
Date: Wed, 2 Mar 2016 23:14:33 +0100
Subject: [PATCH] TCP: Implement dual stack support using new IP_ANY_TYPE
 introduced at UDP

---
 src/core/tcp.c         | 54 +++++++++---------------------------------
 src/core/tcp_in.c      |  9 +++----
 src/include/lwip/tcp.h | 16 +------------
 3 files changed, 15 insertions(+), 64 deletions(-)

diff --git a/src/core/tcp.c b/src/core/tcp.c
index 46f29808..c45a04d0 100644
--- a/src/core/tcp.c
+++ b/src/core/tcp.c
@@ -574,7 +574,6 @@ tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog)
   lpcb->ttl = pcb->ttl;
   lpcb->tos = pcb->tos;
 #if LWIP_IPV4 && LWIP_IPV6
-  lpcb->accept_any_ip_version = 0;
   IP_SET_TYPE_VAL(lpcb->remote_ip, pcb->local_ip.type);
 #endif /* LWIP_IPV4 && LWIP_IPV6 */
   ip_addr_copy(lpcb->local_ip, pcb->local_ip);
@@ -593,40 +592,6 @@ tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog)
   return (struct tcp_pcb *)lpcb;
 }
 
-#if LWIP_IPV4 && LWIP_IPV6
-/**
- * Same as tcp_listen_with_backlog, but allows to accept IPv4 and IPv6
- * connections, if the pcb's local address is set to ANY.
- */
-struct tcp_pcb *
-tcp_listen_dual_with_backlog(struct tcp_pcb *pcb, u8_t backlog)
-{
-  struct tcp_pcb *lpcb;
-  struct tcp_pcb_listen *l;
-
-  if (pcb->local_port != 0) {
-    /* Check that there's noone listening on this port already
-       (don't check the IP address since we'll set it to ANY */
-    for (l = tcp_listen_pcbs.listen_pcbs; l != NULL; l = l->next) {
-      if (l->local_port == pcb->local_port) {
-        /* this port is already used */
-        return NULL;
-      }
-    }
-  }
-
-  lpcb = tcp_listen_with_backlog(pcb, backlog);
-  if ((lpcb != NULL) &&
-      ip_addr_isany(&lpcb->local_ip)) {
-    /* The default behavior is to accept connections on either
-     * IPv4 or IPv6, if not bound. */
-    /* @see NETCONN_FLAG_IPV6_V6ONLY for changing this behavior */
-    ((struct tcp_pcb_listen*)lpcb)->accept_any_ip_version = 1;
-  }
-  return lpcb;
-}
-#endif /* LWIP_IPV4 && LWIP_IPV6 */
-
 /**
  * Update the state that tracks the available window space to advertise.
  *
@@ -1535,26 +1500,29 @@ tcp_new(void)
   return tcp_alloc(TCP_PRIO_NORMAL);
 }
 
-#if LWIP_IPV6
 /**
- * Creates a new TCP-over-IPv6 protocol control block but doesn't
+ * Creates a new TCP protocol control block but doesn't
  * place it on any of the TCP PCB lists.
  * The pcb is not put on any list until binding using tcp_bind().
  *
+ * @param IP address type, see IPADDR_TYPE_XX definitions.
  * @return a new tcp_pcb that initially is in state CLOSED
  */
 struct tcp_pcb *
-tcp_new_ip6(void)
+tcp_new_ip_type(u8_t type)
 {
   struct tcp_pcb * pcb;
   pcb = tcp_alloc(TCP_PRIO_NORMAL);
-#if LWIP_IPV4
-  IP_SET_TYPE_VAL(pcb->local_ip, IPADDR_TYPE_V6);
-  IP_SET_TYPE_VAL(pcb->remote_ip, IPADDR_TYPE_V6);
-#endif /* LWIP_IPV4 */
+#if LWIP_IPV4 && LWIP_IPV6
+  if(pcb != NULL) {
+    IP_SET_TYPE_VAL(pcb->local_ip, type);
+    IP_SET_TYPE_VAL(pcb->remote_ip, type);
+  }
+#else
+  LWIP_UNUSED_ARG(type);
+#endif /* LWIP_IPV4 && LWIP_IPV6 */
   return pcb;
 }
-#endif /* LWIP_IPV6 */
 
 /**
  * Used to specify the argument that should be passed callback
diff --git a/src/core/tcp_in.c b/src/core/tcp_in.c
index 1456ec03..1fba1dcc 100644
--- a/src/core/tcp_in.c
+++ b/src/core/tcp_in.c
@@ -262,18 +262,15 @@ tcp_input(struct pbuf *p, struct netif *inp)
     prev = NULL;
     for (lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
       if (lpcb->local_port == tcphdr->dest) {
-#if LWIP_IPV4 && LWIP_IPV6
-        if (lpcb->accept_any_ip_version) {
-          /* found an ANY-match */
+        if (IP_IS_ANY_TYPE_VAL(lpcb->local_ip)) {
+          /* found an ANY TYPE (IPv4/IPv6) match */
 #if SO_REUSE
           lpcb_any = lpcb;
           lpcb_prev = prev;
 #else /* SO_REUSE */
           break;
 #endif /* SO_REUSE */
-        } else
-#endif /* LWIP_IPV4 && LWIP_IPV6 */
-        if (IP_ADDR_PCB_VERSION_MATCH_EXACT(lpcb, ip_current_dest_addr())) {
+        } else if (IP_ADDR_PCB_VERSION_MATCH_EXACT(lpcb, ip_current_dest_addr())) {
           if (ip_addr_cmp(&lpcb->local_ip, ip_current_dest_addr())) {
             /* found an exact match */
             break;
diff --git a/src/include/lwip/tcp.h b/src/include/lwip/tcp.h
index dddd0fbc..3fb1ef98 100644
--- a/src/include/lwip/tcp.h
+++ b/src/include/lwip/tcp.h
@@ -317,9 +317,6 @@ struct tcp_pcb_listen {
   u8_t backlog;
   u8_t accepts_pending;
 #endif /* TCP_LISTEN_BACKLOG */
-#if LWIP_IPV4 && LWIP_IPV6
-  u8_t accept_any_ip_version;
-#endif /* LWIP_IPV4 && LWIP_IPV6 */
 };
 
 #if LWIP_EVENT_API
@@ -343,6 +340,7 @@ err_t lwip_tcp_event(void *arg, struct tcp_pcb *pcb,
 
 /* Application program's interface: */
 struct tcp_pcb * tcp_new     (void);
+struct tcp_pcb * tcp_new_ip_type (u8_t type);
 
 void             tcp_arg     (struct tcp_pcb *pcb, void *arg);
 void             tcp_accept  (struct tcp_pcb *pcb, tcp_accept_fn accept);
@@ -401,18 +399,6 @@ err_t            tcp_output  (struct tcp_pcb *pcb);
 
 const char* tcp_debug_state_str(enum tcp_state s);
 
-#if LWIP_IPV6
-struct tcp_pcb * tcp_new_ip6 (void);
-#endif /* LWIP_IPV6 */
-#if LWIP_IPV4 && LWIP_IPV6
-struct tcp_pcb * tcp_listen_dual_with_backlog(struct tcp_pcb *pcb, u8_t backlog);
-#define          tcp_listen_dual(pcb) tcp_listen_dual_with_backlog(pcb, TCP_DEFAULT_LISTEN_BACKLOG)
-#else /* LWIP_IPV4 && LWIP_IPV6 */
-#define          tcp_listen_dual_with_backlog(pcb, backlog) tcp_listen_with_backlog(pcb, backlog)
-#define          tcp_listen_dual(pcb) tcp_listen(pcb)
-#endif /* LWIP_IPV4 && LWIP_IPV6 */
-
-
 #ifdef __cplusplus
 }
 #endif