When IPv6 ND kicks in, the packet that caused the ND can either be dropped or saved in a buffer to be send when the NS reply returns. This commit reimplements the buffer management to avoid having one buffer per neighbor, but instead use a buffer pool from which buffers can be allocated for different neighbors.

core/net/uip-ds6.c

@@ -45,6 +45,7 @@
 #include "lib/random.h"
 #include "net/uip-nd6.h"
 #include "net/uip-ds6.h"
+#include "net/uip-packetqueue.h"
 
 #define DEBUG 0
 #if DEBUG
@@ -268,6 +269,7 @@ uip_ds6_list_loop(uip_ds6_element_t * list, uint8_t size,
       element <
       (uip_ds6_element_t *) ((uint8_t *) list + (size * elementsize));
       element = (uip_ds6_element_t *) ((uint8_t *) element + elementsize)) {
+    //    printf("+ %p %d\n", &element->isused, element->isused);
     if(element->isused) {
       if(uip_ipaddr_prefixcmp(&(element->ipaddr), ipaddr, ipaddrlen)) {
         *out_element = element;
@@ -278,7 +280,7 @@ uip_ds6_list_loop(uip_ds6_element_t * list, uint8_t size,
     }
   }
 
-  if(*out_element) {
+  if(*out_element != NULL) {
     return FREESPACE;
   } else {
     return NOSPACE;
@@ -290,10 +292,15 @@ uip_ds6_nbr_t *
 uip_ds6_nbr_add(uip_ipaddr_t * ipaddr, uip_lladdr_t * lladdr,
                 uint8_t isrouter, uint8_t state)
 {
-  if(uip_ds6_list_loop
+  int r;
+
+  r = uip_ds6_list_loop
      ((uip_ds6_element_t *) uip_ds6_nbr_cache, UIP_DS6_NBR_NB,
       sizeof(uip_ds6_nbr_t), ipaddr, 128,
-      (uip_ds6_element_t **) & locnbr) == FREESPACE) {
+      (uip_ds6_element_t **) &locnbr);
+  //  printf("r %d\n", r);
+
+  if(r == FREESPACE) {
     locnbr->isused = 1;
     uip_ipaddr_copy(&(locnbr->ipaddr), ipaddr);
     if(lladdr != NULL) {
@@ -303,6 +310,9 @@ uip_ds6_nbr_add(uip_ipaddr_t * ipaddr, uip_lladdr_t * lladdr,
     }
     locnbr->isrouter = isrouter;
     locnbr->state = state;
+#if UIP_CONF_IPV6_QUEUE_PKT
+    uip_packetqueue_new(&locnbr->packethandle);
+#endif /* UIP_CONF_IPV6_QUEUE_PKT */
     /* timers are set separately, for now we put them in expired state */
     stimer_set(&(locnbr->reachable), 0);
     stimer_set(&(locnbr->sendns), 0);
@@ -315,31 +325,31 @@ uip_ds6_nbr_add(uip_ipaddr_t * ipaddr, uip_lladdr_t * lladdr,
     NEIGHBOR_STATE_CHANGED(locnbr);
 
     locnbr->last_lookup = clock_time();
+    //    printf("add %p\n", locnbr);
     return locnbr;
-  } else {
+  } else if(r == NOSPACE) {
     /* We did not find any empty slot on the neighbor list, so we need
        to remove one old entry to make room. */
-    {
-      uip_ds6_nbr_t *n, *oldest;
-      clock_time_t oldest_time;
+    uip_ds6_nbr_t *n, *oldest;
+    clock_time_t oldest_time;
 
-      oldest = NULL;
-      oldest_time = 0 - 1UL;
+    oldest = NULL;
+    oldest_time = clock_time();
 
-      for(n = uip_ds6_nbr_cache;
-          n < &uip_ds6_nbr_cache[UIP_DS6_NBR_NB];
-          n++) {
-        if(n->isused) {
-          if(n->last_lookup < oldest_time) {
-            oldest = n;
-            oldest_time = n->last_lookup;
-          }
+    for(n = uip_ds6_nbr_cache;
+        n < &uip_ds6_nbr_cache[UIP_DS6_NBR_NB];
+        n++) {
+      if(n->isused) {
+        if(n->last_lookup < oldest_time) {
+          oldest = n;
+          oldest_time = n->last_lookup;
         }
       }
-      if(oldest != NULL) {
-        uip_ds6_nbr_rm(oldest);
-        return uip_ds6_nbr_add(ipaddr, lladdr, isrouter, state);
-      }
+    }
+    if(oldest != NULL) {
+      //      printf("rm3\n");
+      uip_ds6_nbr_rm(oldest);
+      return uip_ds6_nbr_add(ipaddr, lladdr, isrouter, state);
     }
   }
   PRINTF("uip_ds6_nbr_add drop\n");
@@ -352,7 +362,11 @@ uip_ds6_nbr_rm(uip_ds6_nbr_t *nbr)
 {
   if(nbr != NULL) {
     nbr->isused = 0;
-    NEIGHBOR_STATE_CHANGED(nbr);
+#if UIP_CONF_IPV6_QUEUE_PKT
+    //    printf("rm %p\n", &nbr->isused);
+    uip_packetqueue_free(&nbr->packethandle);
+#endif /* UIP_CONF_IPV6_QUEUE_PKT */
+    //    NEIGHBOR_STATE_CHANGED(nbr);
   }
   return;
 }

core/net/uip-ds6.h

@@ -152,20 +152,23 @@
 
 
 /*--------------------------------------------------*/
+#if UIP_CONF_IPV6_QUEUE_PKT
+#include "net/uip-packetqueue.h"
+#endif                          /*UIP_CONF_QUEUE_PKT */
 /** \brief An entry in the nbr cache */
 typedef struct uip_ds6_nbr {
   uint8_t isused;
   uip_ipaddr_t ipaddr;
   uip_lladdr_t lladdr;
-  uint8_t isrouter;
-  uint8_t state;
   struct stimer reachable;
   struct stimer sendns;
-  uint8_t nscount;
   clock_time_t last_lookup;
+  uint8_t nscount;
+  uint8_t isrouter;
+  uint8_t state;
 #if UIP_CONF_IPV6_QUEUE_PKT
-  uint8_t queue_buf[UIP_BUFSIZE - UIP_LLH_LEN];
-  uint8_t queue_buf_len;
+  struct uip_packetqueue_handle packethandle;
+#define UIP_DS6_NBR_PACKET_LIFETIME CLOCK_SECOND * 4
 #endif                          /*UIP_CONF_QUEUE_PKT */
 } uip_ds6_nbr_t;
 

core/net/uip-nd6.c

@@ -135,6 +135,7 @@ static uip_ds6_nbr_t *nbr; /**  Pointer to a nbr cache entry*/
 static uip_ds6_defrt_t *defrt; /**  Pointer to a router list entry */
 static uip_ds6_addr_t *addr; /**  Pointer to an interface address */
 
+
 /*------------------------------------------------------------------*/
 /* create a llao */ 
 static void
@@ -507,12 +508,19 @@ uip_nd6_na_input(void)
   }
 #if UIP_CONF_IPV6_QUEUE_PKT
   /* The nbr is now reachable, check if we had buffered a pkt for it */
-  if(nbr->queue_buf_len != 0) {
+  /*if(nbr->queue_buf_len != 0) {
     uip_len = nbr->queue_buf_len;
     memcpy(UIP_IP_BUF, nbr->queue_buf, uip_len);
     nbr->queue_buf_len = 0;
     return;
+    }*/
+  if(uip_packetqueue_buflen(&nbr->packethandle) != 0) {
+    uip_len = uip_packetqueue_buflen(&nbr->packethandle);
+    memcpy(UIP_IP_BUF, uip_packetqueue_buf(&nbr->packethandle), uip_len);
+    uip_packetqueue_free(&nbr->packethandle);
+    return;
   }
+  
 #endif /*UIP_CONF_IPV6_QUEUE_PKT */
 
 discard:
@@ -918,12 +926,19 @@ uip_nd6_ra_input(void)
 #if UIP_CONF_IPV6_QUEUE_PKT
   /* If the nbr just became reachable (e.g. it was in NBR_INCOMPLETE state
    * and we got a SLLAO), check if we had buffered a pkt for it */
-  if((nbr != NULL) && (nbr->queue_buf_len != 0)) {
+  /*  if((nbr != NULL) && (nbr->queue_buf_len != 0)) {
     uip_len = nbr->queue_buf_len;
     memcpy(UIP_IP_BUF, nbr->queue_buf, uip_len);
     nbr->queue_buf_len = 0;
     return;
+    }*/
+  if(nbr != NULL && uip_packetqueue_buflen(&nbr->packethandle) != 0) {
+    uip_len = uip_packetqueue_buflen(&nbr->packethandle);
+    memcpy(UIP_IP_BUF, uip_packetqueue_buf(&nbr->packethandle), uip_len);
+    uip_packetqueue_free(&nbr->packethandle);
+    return;
   }
+
 #endif /*UIP_CONF_IPV6_QUEUE_PKT */
 
 discard:

core/net/uip-packetqueue.c

@@ -0,0 +1,86 @@
+#include <stdio.h>
+
+#include "net/uip.h"
+
+#include "lib/memb.h"
+
+#include "net/uip-packetqueue.h"
+
+#define MAX_NUM_QUEUED_PACKETS 2
+MEMB(packets_memb, struct uip_packetqueue_packet, MAX_NUM_QUEUED_PACKETS);
+
+#define DEBUG 0
+#if DEBUG
+#include <stdio.h>
+#define PRINTF(...) printf(__VA_ARGS__)
+#else
+#define PRINTF(...)
+#endif
+
+/*---------------------------------------------------------------------------*/
+static void
+packet_timedout(void *ptr)
+{
+  struct uip_packetqueue_handle *h = ptr;
+
+  PRINTF("uip_packetqueue_free timed out %p\n", h);
+  memb_free(&packets_memb, h->packet);
+  h->packet = NULL;
+}
+/*---------------------------------------------------------------------------*/
+void
+uip_packetqueue_new(struct uip_packetqueue_handle *handle)
+{
+  PRINTF("uip_packetqueue_new %p\n", handle);
+  handle->packet = NULL;
+}
+/*---------------------------------------------------------------------------*/
+struct uip_packetqueue_packet *
+uip_packetqueue_alloc(struct uip_packetqueue_handle *handle, clock_time_t lifetime)
+{
+  PRINTF("uip_packetqueue_alloc %p\n", handle);
+  if(handle->packet != NULL) {
+    PRINTF("alloced\n");
+    return NULL;
+  }
+  handle->packet = memb_alloc(&packets_memb);
+  if(handle->packet != NULL) {
+    ctimer_set(&handle->packet->lifetimer, lifetime,
+               packet_timedout, handle);
+  } else {
+    PRINTF("uip_packetqueue_alloc failed\n");
+  }
+  return handle->packet;
+}
+/*---------------------------------------------------------------------------*/
+void
+uip_packetqueue_free(struct uip_packetqueue_handle *handle)
+{
+  PRINTF("uip_packetqueue_free %p\n", handle);
+  if(handle->packet != NULL) {
+    ctimer_stop(&handle->packet->lifetimer);
+    memb_free(&packets_memb, handle->packet);
+    handle->packet = NULL;
+  }
+}
+/*---------------------------------------------------------------------------*/
+uint8_t *
+uip_packetqueue_buf(struct uip_packetqueue_handle *h)
+{
+  return h->packet != NULL? h->packet->queue_buf: NULL;
+}
+/*---------------------------------------------------------------------------*/
+uint16_t
+uip_packetqueue_buflen(struct uip_packetqueue_handle *h)
+{
+  return h->packet != NULL? h->packet->queue_buf_len: 0;
+}
+/*---------------------------------------------------------------------------*/
+void
+uip_packetqueue_set_buflen(struct uip_packetqueue_handle *h, uint16_t len)
+{
+  if(h->packet != NULL) {
+    h->packet->queue_buf_len = len;
+  }
+}
+/*---------------------------------------------------------------------------*/

core/net/uip-packetqueue.h

@@ -0,0 +1,35 @@
+#ifndef UIP_PACKETQUEUE_H
+#define UIP_PACKETQUEUE_H
+
+#include "sys/ctimer.h"
+
+struct uip_packetqueue_handle;
+
+struct uip_packetqueue_packet {
+  struct uip_ds6_queued_packet *next;
+  uint8_t queue_buf[UIP_BUFSIZE - UIP_LLH_LEN];
+  uint16_t queue_buf_len;
+  struct ctimer lifetimer;
+  struct uip_packetqueue_handle *handle;
+};
+
+struct uip_packetqueue_handle {
+  struct uip_packetqueue_packet *packet;
+};
+
+void uip_packetqueue_new(struct uip_packetqueue_handle *handle);
+
+
+struct uip_packetqueue_packet *
+uip_packetqueue_alloc(struct uip_packetqueue_handle *handle, clock_time_t lifetime);
+
+
+void
+uip_packetqueue_free(struct uip_packetqueue_handle *handle);
+
+uint8_t *uip_packetqueue_buf(struct uip_packetqueue_handle *h);
+uint16_t uip_packetqueue_buflen(struct uip_packetqueue_handle *h);
+void uip_packetqueue_set_buflen(struct uip_packetqueue_handle *h, uint16_t len);
+
+
+#endif /* UIP_PACKETQUEUE_H */