[lwip-devel] Question about "Fix regression in etharp.c: Allocate correct pbuf layer"

[Axel Lin]

Hi Dirk,

I found below commit:

commit 4456c7d230d91ac60401db02e15178fe0636007d

Author: Dirk Ziegelmeier <address@hidden>

Date:   Tue Aug 23 12:32:57 2016 +0200

    Fix regression in etharp.c: Allocate correct pbuf layer

diff --git a/src/core/ipv4/etharp.c b/src/core/ipv4/etharp.c

index 5288b74..42485d1 100644

--- a/src/core/ipv4/etharp.c

+++ b/src/core/ipv4/etharp.c

@@ -1097,7 +1097,7 @@ etharp_query(struct netif *netif, const ip4_addr_t *ipaddr, struct pbuf *q)

     }

     if (copy_needed) {

       /* copy the whole packet into new pbufs */

-      p = pbuf_alloc(PBUF_RAW_TX, p->tot_len, PBUF_RAM);

+      p = pbuf_alloc(PBUF_LINK, p->tot_len, PBUF_RAM);

       if (p != NULL) {

         if (pbuf_copy(p, q) != ERR_OK) {

           pbuf_free(p);

Since the commit log says it's a regression, may I know which commit cause

the problem and what is the user visible impact of the issue.

In

commit 979bee386c60fbd5f74a5e7bb3e2e25af35ef46e

Author: Dirk Ziegelmeier <address@hidden>

Date:   Tue Aug 23 16:58:17 2016 +0200

    Work on bug #48868: Cleanup etharp.c not to use struct eth_hdr: Cleanup etharp_raw() to use ethernet_output()

There is below change, it's not clear to me if this is a fix or a clean up.

   /* allocate a pbuf for the outgoing ARP request packet */

-  p = pbuf_alloc(PBUF_RAW_TX, SIZEOF_ETHARP_PACKET_TX, PBUF_RAM);

+  p = pbuf_alloc(PBUF_LINK, SIZEOF_ETHARP_PACKET_TX, PBUF_RAM);

I asked above questions because I have project still using lwip-1.4.1 which has below codes (I'm not sure if I need to update my code in lwip-1.4.1 as well.):

In etharp_query():

      /* copy the whole packet into new pbufs */

      p = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);

and ...

in etharp_raw():

  /* allocate a pbuf for the outgoing ARP request packet */

  p = pbuf_alloc(PBUF_RAW, SIZEOF_ETHARP_PACKET, PBUF_RAM);

Regards,

Axel