[lwip-devel] bridgeif.c questions

[Gisle Vanem]

I've been playing a bit with the new bridgeif.c functions
in my Windows test-app. But it seems to be a real memory hog.
Even with '#define BRIDGEIF_MAX_PORTS 1',
it reports:
  allocating 244256 bytes for private data
  out of memory

Then after increasing MEM_SIZE to 300kByte, it continues to allocate
484952 bytes more in bridgeif_fdb_init(). It fails and crashes.
Here is a patch I used:

--- a/src/netif/bridgeif.c 2017-04-04 11:18:19
+++ b/src/netif/bridgeif.c 2017-04-04 15:37:39
@@ -221,8 +221,9 @@
   bridgeif_dfdb_t *fdb;
   mem_size_t alloc_len = sizeof(bridgeif_dfdb_t) + 
(max_fdb_entries*sizeof(bridgeif_dfdb_entry_t));
   LWIP_DEBUGF(BRIDGEIF_DEBUG, ("bridgeif_init: allocating %d bytes for private 
data\n", (int)alloc_len));
-  fdb = (bridgeif_dfdb_t*)mem_malloc(alloc_len);
-  memset(fdb, 0, alloc_len);
+  fdb = (bridgeif_dfdb_t*)mem_calloc(alloc_len,1);
+  if (!fdb)
+     return NULL;
   fdb->max_fdb_entries = max_fdb_entries;
   fdb->fdb = (bridgeif_dfdb_entry_t *)(fdb + 1);
   return fdb;
@@ -579,12 +580,11 @@

   alloc_len = sizeof(bridgeif_private_t) + (init_data->max_ports*sizeof(bridgeif_port_t) + 
(init_data->max_fdb_static_e ntries*sizeof(bridgeif_fdb_static_entry_t)));
   LWIP_DEBUGF(BRIDGEIF_DEBUG, ("bridgeif_init: allocating %d bytes for private 
data\n", (int)alloc_len));
-  br = (bridgeif_private_t*)mem_malloc(alloc_len);
+  br = (bridgeif_private_t*)mem_calloc(alloc_len,1);
   if (br == NULL) {
     LWIP_DEBUGF(NETIF_DEBUG, ("bridgeif_init: out of memory\n"));
     return ERR_MEM;
   }
-  memset(br, 0, alloc_len);
   memcpy(&br->ethaddr, &init_data->ethaddr, sizeof(br->ethaddr));
   br->netif = netif;

@@ -596,6 +596,10 @@

   br->max_fdbd_entries = init_data->max_fdb_dynamic_entries;
   br->fdbd = bridgeif_fdb_init(init_data->max_fdb_static_entries);
+  if (br->fdbd == NULL) {
+    LWIP_DEBUGF(NETIF_DEBUG, ("bridgeif_init: out of memory\n"));
+    return ERR_MEM;
+  }

 #if LWIP_NETIF_HOSTNAME
   /* Initialize interface hostname */

---------------

But I'm not sure how this bridge should work with pcapif.c.
Do I need 2 WPcap ifaces and somehow join those with bridge_add_port()?

Since there's no example for it AFAICS, I'm now sure how to initialise it.
Which 'struct netif *' should I use in bridgeif_init()?

Thanks.

--
--gv