[lwip-devel] [bug #56014] The ICMPv6 Parameter Problem doesn't take the IPv6 Header of the offending packet

[Gao Qingshui]

URL:
  <https://savannah.nongnu.org/bugs/?56014>

                 Summary: The ICMPv6 Parameter Problem doesn't take the IPv6
Header of the offending packet
                 Project: lwIP - A Lightweight TCP/IP stack
            Submitted by: kevingao
            Submitted on: Thu 28 Mar 2019 04:30:01 AM UTC
                Category: IPv6
                Severity: 3 - Normal
              Item Group: Faulty Behaviour
                  Status: None
                 Privacy: Public
             Assigned to: None
             Open/Closed: Open
         Discussion Lock: Any
         Planned Release: None
            lwIP version: git head

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Details:

The ICMPv6 Parameter Problem doesn't take the IPv6 Header of the offending
packet as the p->payload not point to the IP header of the orignal packet.so
before calling icmp6_send_response to sending PP back to the originator, lwip
must move the p->payload pointer back to ip header.
There was two ways to fix this issue:
1) move the p->payload pointer back to ip header in function
icmp6_param_problem
2) do this action before calling icmp6_param_problem
The 1st way is simple, but break the code style if icmpv6 related function, as
all the err message
function(icmp6_dest_unreach,icmp6_packet_too_big,icmp6_time_exceeded,icmp6_param_problem)
were in the same style and the p->payload always point to ip header.
The 2nd way is a little complex, we should modify several places, but it would
keep the code style and make the code more readable.
The attached patch file was my modification using the 2nd way, pls review.



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File Attachments:


-------------------------------------------------------
Date: Thu 28 Mar 2019 04:30:01 AM UTC  Name:
icmpv6-parameter-problem-not-take-the-IP-header-of-the-offending-packet.patch 
Size: 5KiB   By: kevingao

<http://savannah.nongnu.org/bugs/download.php?file_id=46652>

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