[lwip-devel] [bug #45829] ipX_to_ip() function does not work when just one IP version supported

[Erik Ekman]

URL:
  <http://savannah.nongnu.org/bugs/?45829>

                 Summary: ipX_to_ip() function does not work when just one IP
version supported
                 Project: lwIP - A Lightweight TCP/IP stack
            Submitted by: yarrick
            Submitted on: Wed 26 Aug 2015 09:05:48 AM GMT
                Category: IPv4
                Severity: 3 - Normal
              Item Group: Faulty Behaviour
                  Status: None
                 Privacy: Public
             Assigned to: None
             Open/Closed: Open
         Discussion Lock: Any
         Planned Release: 
            lwIP version: git head

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Details:

When both IP versions are supported, ip4_to_ip()/ip6_to_ip() converts the IP
version-specific first argument to an IP version-independent type given as the
second argument.

To work the same way when only one IP version is supported the first argument
needs to be copied to the second.

Consider the following code (choose destination address and pcb based on IP
version of incoming packet):

#if LWIP_IPV4
ip4_addr_t v4addr = ..;
#endif
#if LWIP_IPV6
ip6_addr_t v6addr = ..;
#endif

struct {
#if LWIP_IPV4
  struct udp_pcb *v4pcb;
#endif
#if LWIP_IPV6
  struct udp_pcb *v6pcb;
#endif
} data;

....
{
    ip_addr_t tempaddr;
    struct udp_pcb *pcb = NULL;

    if (IP_IS_V6_VAL(source_addr)) {
#if LWIP_IPV6
      ip6_2_ip(&v6addr, &tempaddr);
      pcb = data.v6pcb;
#endif
    } else {
#if LWIP_IPV4
      ip4_2_ip(&v4addr, &tempaddr);
      pcb = data.v4pcb;
#endif
    }
    udp_sendto_if(pcb, pbuf, &tempaddr, port, netif);
}

This code works when both IP versions are enabled but break if only one is,
since the ipX_to_ip() functions do different things.



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File Attachments:


-------------------------------------------------------
Date: Wed 26 Aug 2015 09:05:48 AM GMT  Name:
0001-Make-ipX_to_ip-work-when-just-one-IP-version-support.patch  Size: 2kB  
By: yarrick

<http://savannah.nongnu.org/bugs/download.php?file_id=34733>

    _______________________________________________________

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