Fix MPLS header parsing in ndpiReader. #506
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Reported at https://bugs.debian.org/886133. The current parsing for the MPLS header in examples/ndpi_util.c has multiple issues: - the bitfield order is incorrect for little endian architectures - ntohl() is applied to a 20 bit label, which has unclear purpose - if multiple labels are detected, the while loop parsing labels will never exit due to a missing re-read of the mpls label - the last label is identified by looking inside the label field, while it should be done by looking at the S bit This change fixes the above issues. Notice that bitfield ordering is implementation-dependent, so C bitfields should not be used in the first place to parse network packets.
|
Many thanks! |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Reported at https://bugs.debian.org/886133.
The current parsing for the MPLS header in examples/ndpi_util.c has
multiple issues:
never exit due to a missing re-read of the mpls label
it should be done by looking at the S bit
This change fixes the above issues.
Notice that bitfield ordering is implementation-dependent, so C
bitfields should not be used in the first place to parse network
packets.