fixed bug #40753 (re-bind UDP pcbs on change of IP address)

CHANGELOG

@@ -6,6 +6,9 @@ HISTORY
 
   ++ New features:
 
+  2015-02-22: patch by TabascoEye
+  * netif.c, udp.h/.c: fixed bug #40753 (re-bind UDP pcbs on change of IP address)
+
   2015-02-22: chrysn, Simon Goldschmidt
   * *.*: Changed nearly all functions taking 'ip(X)_addr_t' pointer to take
     const pointers (changed user callbacks: raw_recv_fn, udp_recv_fn; changed

src/core/netif.c

@@ -390,9 +390,11 @@ netif_set_ipaddr(struct netif *netif, const ip_addr_t *ipaddr)
 #if LWIP_TCP
   struct tcp_pcb *pcb;
   struct tcp_pcb_listen *lpcb;
+#endif /* LWIP_TCP */
 
   /* address is actually being changed? */
   if (ipaddr && (ip_addr_cmp(ipaddr, &(netif->ip_addr))) == 0) {
+#if LWIP_TCP
     /* extern struct tcp_pcb *tcp_active_pcbs; defined by tcp.h */
     LWIP_DEBUGF(NETIF_DEBUG | LWIP_DBG_STATE, ("netif_set_ipaddr: netif address being changed\n"));
     pcb = tcp_active_pcbs;
@@ -422,8 +424,12 @@ netif_set_ipaddr(struct netif *netif, const ip_addr_t *ipaddr)
         ip_addr_set(ipX_2_ip(&lpcb->local_ip), ipaddr);
       }
     }
+#endif /* LWIP_TCP */
+#if LWIP_UDP
+    udp_netif_ipv4_addr_changed(&netif->ip_addr, ipaddr);
+#endif /* LWIP_UDP */
   }
-#endif
+
   snmp_delete_ipaddridx_tree(netif);
   snmp_delete_iprteidx_tree(0,netif);
   /* set new IP address to netif */

src/core/udp.c

@@ -1151,6 +1151,26 @@ udp_new_ip6(void)
 }
 #endif /* LWIP_IPV6 */
 
+/** This function is called from netif.c when address is changed
+ *
+ * @param old_addr IPv4 address of the netif before change
+ * @param new_addr IPv4 address of the netif after change
+ */
+void udp_netif_ipv4_addr_changed(const ip_addr_t* old_addr, const ip_addr_t* new_addr)
+{
+  struct udp_pcb* upcb;
+
+  for (upcb = udp_pcbs; upcb != NULL; upcb = upcb->next) {
+    /* PCB bound to current local interface address? */
+    if ((!(ip_addr_isany(ipX_2_ip(&upcb->local_ip)))) &&
+        (ip_addr_cmp(ipX_2_ip(&upcb->local_ip), old_addr))) {
+      /* The PCB is bound to the old ipaddr and
+        * is set to bound to the new one instead */
+      ip_addr_set(ipX_2_ip(&upcb->local_ip), new_addr);
+    }
+  }
+}
+
 #if UDP_DEBUG
 /**
  * Print UDP header information for debug purposes.

src/include/lwip/udp.h

@@ -221,6 +221,8 @@ void udp_debug_print(struct udp_hdr *udphdr);
 #define udp_debug_print(udphdr)
 #endif
 
+void udp_netif_ipv4_addr_changed(const ip_addr_t* old_addr, const ip_addr_t* new_addr);
+
 #ifdef __cplusplus
 }
 #endif