Fix crash handling publish with invalid predef topic ID.#9
Open
phildubach wants to merge 3 commits into
Open
Conversation
added 3 commits
April 5, 2017 15:05
When subscribing to a named topic check for existing registrations of the topic and reuse the existing topic ID on success, rather than blindly registering the topic. This avoids duplicate registrations of the same topic with different topic IDs.
If a message gets queued for a client, because the maximum number of inflight messages has been reached, the server should attempt to dequeue and send that message whenever a publish is completed. Copy the relevant code from the plain MQTT handlePubacks and handlePubcomps functions.
This file contains hidden or 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
1 participant
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
A client publishing with an invalid predefined topic ID would crash the broker.
This is caused by code added for expanding predefined topic templates.
Expansion was not attempted if the original topic lookup failed, but code further down unconditionally tried to compare the original topic string (which is NULL in this case) with the expanded topic string (also NULL), resulting in a segmentation fault.
Simply moving the code inside the conditional block solves the problem by falling through with topicName being NULL, which results in a proper PUBACK with the error code MQTTS_RC_REJECTED_INVALID_TOPIC_ID.