Re: [lwip-devel] DNS_SERVER_ADDRESS() macro for core/dns.c

[Gisle Vanem]

Simon Goldschmidt wrote:

> The direct replacement for ip4_addr_set_u32() is ip_addr_set_ip4_u32() when 
> using dual-version mode.

You mean like this:
 #define DNS_SERVER_ADDRESS(a)   \
         ip_addr_set_ip4_u32(a, ipaddr_addr("8.8.8.8")) /* 
google-public-dns-a.google.com */

This works fine when building with both LWIP_IPV6=0 or 1.
At least with MingW or TDM-gcc 5.1, but in MSVC-2015 I get a
crash. Call-stack in WinDbg:

test_app!udp_sendto_if(struct udp_pcb * pcb = 0x00000100,
  struct pbuf * p = 0x00530348, struct ip4_addr * dst_ip = 0x00d99d68,
  unsigned short dst_port = 0x35, struct netif * netif = 0x00d9a540)+0xf

test_app!udp_sendto(struct udp_pcb * pcb = 0x00000100, struct pbuf * p = 
0x00530348,
  struct ip4_addr * dst_ip = 0x00d99d68, unsigned short dst_port = 0x35)+0xd0
test_app!dns_send(unsigned char idx = 0x00 '')+0x1ba
test_app!dns_check_entry+0xac
test_app!dns_check_entries(void)+0xbc
test_app!cyclic_timer(void * arg = 0x00d98508)+0xa
...

----------

Note the 'pcb = 0x100' in the above udp_sendto_if(); a bogus address
used in this code:
  if (ip4_addr_isany(ip_2_ip4(&pcb->local_ip))) {
   ....

Not sure it's related to my DNS_SERVER_ADDRESS() macro. Will dig into
this later.

-- 
--gv