rpc: handle denied replies #5
Open
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
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Outdated suggestions cannot be applied.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.
RPC reply bodies can be either MSG_ACCEPTED or MSG_DENIED:
https://www.rfc-editor.org/rfc/rfc1831.html#page-11
MSG_ACCEPTED are 24 bytes long (6 fields of 4 bytes):
This is correctly handled by current code.
MSG_DENIED however are shorter, 20 bytes (5 fields of 4 bytes):
So
struct.unpack('!LLLLLL', rpc)fails on MSG_DENIED replies (not enough data to unpack).The proposed patch only unpacks the first 3 fields, checks if it's a MSG_DENIED and exits then, then only unpack the rest if it's a MSG_ACCEPTED
This is similar to this: https://github.com/nmap/nmap/blob/1ae88d2620a31639018e649c5353fa4b24387262/nselib/rpc.lua#L389