March 2018 - tor-dev - lists.torproject.org

3.2.10 compiler warnings
by grarpamp 11 Mar '18

11 Mar '18

Test from an older system before it was updated, unlikely to be prevalent, so don't bother fixing unless obvious. src/common/confline.c:135: warning: 'include_list' may be used uninitialized in this function src/common/confline.c:135: warning: 'include_list' may be used uninitialized in this function src/or/connection.c:1883: warning: passing argument 1 of 'TO_OR_CONN' discards qualifiers from pointer target type src/or/conscache.c:426: warning: passing argument 2 of 'consensus_cache_entry_map' discards qualifiers from pointer target type src/or/control.c:6815: warning: passing argument 1 of 'TO_OR_CONN' discards qualifiers from pointer target type src/or/scheduler.c:577: warning: format '%ld' expects type 'long int', but argument 5 has type 'time_t' src/or/connection.c:1883: warning: passing argument 1 of 'TO_OR_CONN' discards qualifiers from pointer target type src/or/conscache.c:426: warning: passing argument 2 of 'consensus_cache_entry_map' discards qualifiers from pointer target type src/or/control.c:6815: warning: passing argument 1 of 'TO_OR_CONN' discards qualifiers from pointer target type src/or/scheduler.c:577: warning: format '%ld' expects type 'long int', but argument 5 has type 'time_t' src/test/vote_descriptors.inc:93: warning: string length '4135' is greater than the length '4095' ISO C99 compilers are required to support src/test/test_hs_descriptor.inc:224: warning: string length '14104' is greater than the length '4095' ISO C99 compilers are required to support src/test/test_microdesc.c:648: warning: string length '5844' is greater than the length '4095' ISO C99 compilers are required to support src/test/test_descriptors.inc:305: warning: string length '10571' is greater than the length '4095' ISO C99 compilers are required to support

2 2

Proposal Waterfilling
by Florentin Rochet 09 Mar '18

09 Mar '18

Hello everyone, In order that our paper does not fall into the list of "yet another seems-to-be-cool-feature is that never going to be discussed because researchers moved on another topic", here is an attached proposal in which we summarize our work published in the last PETS event and how it can be implemented. And, if you find this interesting, I would be glad to submit a patch :) Any kind of feedbacks is more than welcome! Cheers! Florentin

8 29

Proposal 290: Continuously update consensus methods
by Nick Mathewson 03 Mar '18

03 Mar '18

Filename: 290-deprecate-consensus-methods.txt Title: Continuously update consensus methods Author: Nick Mathewson Created: 2018-02-21 Status: Open 1. Background Directory authorities use the "consensus method" mechanism to achieve forward compatibility during voting. When each authority publishes its vote, it includes a list of numbered consensus methods that it supports. Each authority chooses to calculate the consensus according to the highest consensus method it knows supported by more than 2/3 of the voting authorities. So long as all the authorities have a method in common, they will all reach the same consensus. Consensus method 1 was first introduced in the Tor 0.2.0 series around 2008. But by 2012, we realized that we had a problem: we were stuck documenting and supporting old consensus methods indefinitely. With proposal 215, we deprecated and removed support for all consensus methods before method 13. That was good as far as it went, but it didn't solve the problem going forward: the latest consensus methods is now 28. This proposal describes a policy for removing older consensus methods going forward, so we won't have to keep supporting them forever. 2. Proposal I propose that from time to time, old consensus methods should be deprecated. Specifically, I propose that we deprecate all methods older than the highest method supported in first stable release of the oldest LTS (long-term support) release series. For example, the current oldest LTS series is 0.2.5.x. The first stable release in that series was 0.2.5.10. The highest consensus method listed by 0.2.5.10 is 18. Therefore, we should currently consider ourselves free to deprecate all methods before 18. Once 0.2.5.x is deprecated, 0.2.9.x will become the oldest LTS series. The first stable release in that series was 0.2.9.8. The highest consensus method listed by 0.2.9.8 is 25. Therefore, once 0.2.5.x is deprecated (in May 2018), we may deprecate all methods before 25. When a consensus method is deprecated, it should no longer be listed or implemented by the latest Tor releases. (It's okay for older authorities to keep advertising it.) Most consensus methods add a feature that is used in "method M or later". Deprecating method M-1 means that the feature is used in all supported consensus methods. Therefore, we can remove any code that makes the feature conditional on a consensus method, and any code for previous implementations of the feature. Some consensus methods remove a feature that was used up to method N. Deprecating method M means that the feature is no longer used by any supported consensus methods. Therefore, we can remove any code that implements the feature. A. Acknowledgments Thanks to isis and teor for the discussion that led to this proposal. I believe that teor first suggested the policy described in section 2 above. B. Client and relay compatibility notes Dear reader: you may be worrying that this proposal will cause old clients or relays to stop working prematurely. That is not the case. Consensus methods determine how the authorities behave, but they do not represent backward-incompatible changes in how they generate their consensuses.

3 2