Merge branch 'bugfix/fix_ipv6_nd6_issue_v3.1' into 'release/v3.1'

fix ipv6 nd6 issue.(backport v3.1)

See merge request espressif/esp-idf!10532

components/lwip/Kconfig

@@ -463,6 +463,20 @@ config TCPIP_TASK_STACK_SIZE
        Configure TCP/IP task stack size, used by LWIP to process multi-threaded TCP/IP operations.
        Setting this stack too small will result in stack overflow crashes.
 
+config LWIP_IPV6_MEMP_NUM_ND6_QUEUE
+    int "Max number of IPv6 packets to queue during MAC resolution"
+    range 3 20
+    default 3
+    help
+        Config max number of IPv6 packets to queue during MAC resolution.
+
+config LWIP_IPV6_ND6_NUM_NEIGHBORS
+    int "Max number of entries in IPv6 neighbor cache"
+    range 3 10
+    default 5
+    help
+        Config max number of entries in IPv6 neighbor cache
+
 menuconfig PPP_SUPPORT
     bool "Enable PPP support (new/experimental)"
     default n

components/lwip/core/ipv6/nd6.c

@@ -1636,6 +1636,12 @@ nd6_queue_packet(s8_t neighbor_index, struct pbuf * q)
   if (copy_needed) {
     /* copy the whole packet into new pbufs */
     p = pbuf_alloc(PBUF_LINK, q->tot_len, PBUF_RAM);
+#if ESP_ND6_QUEUEING
+    if(p == NULL) {
+      pbuf_free(q);
+      return ERR_MEM;
+    }
+#else
     while ((p == NULL) && (neighbor_cache[neighbor_index].q != NULL)) {
       /* Free oldest packet (as per RFC recommendation) */
 #if LWIP_ND6_QUEUEING
@@ -1655,6 +1661,7 @@ nd6_queue_packet(s8_t neighbor_index, struct pbuf * q)
         p = NULL;
       }
     }
+#endif
   } else {
     /* referencing the old pbuf is enough */
     p = q;
@@ -1675,6 +1682,7 @@ nd6_queue_packet(s8_t neighbor_index, struct pbuf * q)
       new_entry = (struct nd6_q_entry *)memp_malloc(MEMP_ND6_QUEUE);
     }
     if (new_entry != NULL) {
+      unsigned int qlen = 0;
       new_entry->next = NULL;
       new_entry->p = p;
       if (neighbor_cache[neighbor_index].q != NULL) {
@@ -1682,12 +1690,22 @@ nd6_queue_packet(s8_t neighbor_index, struct pbuf * q)
         r = neighbor_cache[neighbor_index].q;
         while (r->next != NULL) {
           r = r->next;
+          qlen++;
         }
         r->next = new_entry;
       } else {
         /* queue did not exist, first item in queue */
         neighbor_cache[neighbor_index].q = new_entry;
       }
+#if ESP_ND6_QUEUEING
+      if (qlen >= MEMP_NUM_ND6_QUEUE) {
+        r->next = NULL;
+        pbuf_free(new_entry->p);
+        memp_free(MEMP_ND6_QUEUE, new_entry);
+        LWIP_DEBUGF(LWIP_DBG_TRACE, ("ipv6: could not queue the packet %p (queue is full)\n", (void *)q));
+        return ERR_MEM;
+      }
+#endif
       LWIP_DEBUGF(LWIP_DBG_TRACE, ("ipv6: queued packet %p on neighbor entry %"S16_F"\n", (void *)p, (s16_t)neighbor_index));
       result = ERR_OK;
     } else {

components/lwip/include/lwip/lwip/opt.h

@@ -2537,6 +2537,14 @@
 #define LWIP_ND6_QUEUEING               (LWIP_IPV6)
 #endif
 
+/**
+ * ESP_ND6_QUEUEING==1: queue outgoing IPv6 packets while MAC address
+ * is being resolved.
+ */
+#if !defined ESP_ND6_QUEUEING
+#define ESP_ND6_QUEUEING                (LWIP_IPV6)
+#endif
+
 /**
  * MEMP_NUM_ND6_QUEUE: Max number of IPv6 packets to queue during MAC resolution.
  */

components/lwip/include/lwip/port/lwipopts.h

@@ -633,6 +633,16 @@
  */
 #define LWIP_IPV6                       1
 
+/**
+ * MEMP_NUM_ND6_QUEUE: Max number of IPv6 packets to queue during MAC resolution.
+ */
+#define MEMP_NUM_ND6_QUEUE              CONFIG_LWIP_IPV6_MEMP_NUM_ND6_QUEUE
+
+/**
+ * LWIP_ND6_NUM_NEIGHBORS: Number of entries in IPv6 neighbor cache
+ */
+#define LWIP_ND6_NUM_NEIGHBORS          CONFIG_LWIP_IPV6_ND6_NUM_NEIGHBORS
+
 /*
    ---------------------------------------
    ---------- Hook options ---------------