buglwIP - A Lightweight TCP/IP stack - Bugs: bug #45322, ICMP echo reply checksum wrong on...

 
 

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bug #45322: ICMP echo reply checksum wrong on NULL Bytes payload

Submitted by:  TabascoEye <tabascoeye>
Submitted on:  Mon 15 Jun 2015 09:23:12 AM UTC  
 
Category: IPv4Severity: 3 - Normal
Item Group: Faulty BehaviourStatus: Fixed
Privacy: PublicAssigned to: None
Open/Closed: ClosedPlanned Release: None
lwIP version: git head

Mon 15 Jun 2015 01:58:00 PM UTC, comment #1:

I cherry picked 32c32d8e26 in your github repository, removed the childish ¯\_(ツ)_/¯ from authorship and reworded the commit message.

Sylvain

Sylvain Rochet <gradator>
Project Member
Mon 15 Jun 2015 09:23:12 AM UTC, original submission:

When a client sends an ICMP echo request with ID 0, Sequence 0 and either no data or any amount of 0x00 Bytes as data, the checksum in the reply by LWIP is wrong (off-by-one).

Expected checksum is 0xffff in that case, observed is 0x0000.
So the client does not see that reply as valid and determines the LWIP device as unreachable.

Attached patch fixes the off-by-one error when checksum should be 0xffff

TabascoEye <tabascoeye>

 

Attached Files
file #34223:  ping_reply_to_0_bytes_payload.diff added by tabascoeye (553B - application/octet-stream)

 

Depends on the following items: None found

Items that depend on this one: None found

 

Carbon-Copy List
  • -unavailable- added by gradator (Posted a comment)
  • -unavailable- added by tabascoeye (Submitted the item)
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    Follow 3 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Mon 15 Jun 2015 01:58:00 PM UTCgradatorStatusNone=>Fixed
      Open/ClosedOpen=>Closed
    Mon 15 Jun 2015 09:23:12 AM UTCtabascoeyeAttached File-=>Added ping_reply_to_0_bytes_payload.diff, #34223

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