- tor-dev - lists.torproject.org

Interested in contributing to Tor-Dev through GSoC
by Ashish Patil 10 Mar '13

10 Mar '13

Hello! I am a newbie & very eager to contribute to Tor development. I have been using tor since a year and a half & I have been looking around the website & the source codes since past month. The upcoming GSoC has provided a very nice opportunity for me contribute to whatever extent I can. I have interest towards Stem & Obfsproxy due to their applications & would like some beginner's guidance for the same. Also, I would appreciate if anyone could provide me some online references that would help me understand networking better (in order to understand the source code fully, also is that completely necessary?) PS - I am very well acquainted in Python & have also contributed to it's development but only in Documentation aspect, hence have good knowledge of revision control, building, etc. Thanks! -Ashish Patil

3 6

Interested in contributing to tor through GSoC
by Anirudh Vemula 09 Mar '13

09 Mar '13

Hi, I use tor everyday in my college as we have a http proxy which blocks specific sites. It has been a huge help for me and I would like to improve it by contributing to it by implementing new ways and resolving bugs. I would like to do this year's GSoC with the tor organisation and I felt it would be better for me if i get acquainted with the source code well beforehand. I need suggestions on how to start going about understanding the source code. I would love if there are bugs and mini-projects that a beginner could resolve and improve my understanding of the source code. Thanks Anirudh V Anirudh Vemula | Junior Undergraduate | Computer Science & Engineering | vvanirudh.blog.com | Alumni Secretary Hostel 2 | IIT Bombay

2 1

[ooni] proposed specification for ooni backend component
by Arturo Filastò 06 Mar '13

06 Mar '13

Greetings! It would be great to get some feedback on the specification of oonib that is the backend component of ooniprobe. As later said, not everything described here is implemented, but this document details what oonib should become. Moreover if there is something that you believe we should pay special attention to in when implementing this it would be of great use to know. If you wish to modify this spec directly you can send us a pull request on github: https://github.com/TheTorProject/ooni-spec ------------------------------------- # oonib specification * version: 0.1 * date: 2013-03-04 * author: Arturo Filastò This document aims at providing a functional specification of oonib. At the time of writing this document not all parts are fully implemented, though the application interface to oonib is. # 1.0 System overview oonib is the backend component of ooni. It is responsible for: * Collecting the results of tests from ooni-probes (Collector). * Exposing a set of services that are needed for allowing ooni-probes to perform their tests (Test Helpers). # 2.0 Collector ## 2.1 System overview The oonib collector exposes a JSON RPC like HTTP interface and allows probes to submit the results of their measurements. Once probe measurement is complete the test result is published as an ooni test report in the YAML format. The oonib collector shall be exposed as a Tor Hidden Service and as a HTTPS service. ## 2.2 Theat model The collector shall provide end-to-end between the probe and the oonib collector. A malicious actor should not be able to update test results that they have not created. It is outside of the scope of the oonib collector to provide blocking resistance or to conceal to a passive network observer the fact that they are communicating to a collector. Such properties are to be provided by other software components, for example using Tor or obfsproxy. ## 2.3 Test result submission interface Unless otherwise stated all of the network operations below can be performed either via HTTPS or HTTPO (HTTP over Tor Hidden Service). Note: we will eventually want to migrate over to using YAML instead of JSON as a data exchange format. Not doing so adds unnecessary overhead in including YAML data inside of JSON data. ### 2.3.1 Create a new report When a probe starts a test they will *create* a new report with the oonib collector backend. The HTTP request it performs is: `POST /report` { 'software_name': `string` the name of the software that is creating a report (ex. "ooni-probe") 'software_version': `string` the version of the software creating the report (ex. "0.0.10-beta") 'probe_asn': `string` the Authonomous System Number of the network the test is related to prefixed by "AS" (ex. "AS1234") 'test_name': `string` the name of the test performing the network measurement. In the case of ooni-probe this is the test filename without the ".py" extension. 'test_version': `string` the version of the test peforming the network measurement. 'content': (optional) `string` it is optionally possible to create a report with already some data inside of it. 'probe_ip': (optional) `string` the IP Address of the ooniprobe client. When the test requires a test_helper the probe should inform oonib of it's IP address. We need to know this since we are not sure if the probe is accessing the report collector via Tor or not. } The server will respond with a report identifier that will then allow the probe to update the report and the version of the backend software like follows: { 'backend_version': `string` containing the version of the backend 'report_id': `string` report identifier of the format detailed below. 'test_helper_address': `string` the address of a test helper for the requested test. } The report identifier allows the probe to update the report and it will be contructed as follows: ISO 8601 timestamp + '_' + probe ASN + '_' + 50 mixed lowercase uppercase characters A report identifier can be for example: 1912-06-23T101234Z_AS1234_ihvhaeZDcBpDwYTbmdyqZSLCDNuJSQuoOdJMciiQWwAWUKJwmR Note: The report identifier should be at least 256 bits and generated by means of a CSPRNG. Client implementation notes: Probes should not expect the report identifier to be in a particular format as the report id may be changed in the future. ### 2.3.2 Update a report Once the probe has a report ID they will be able to add test related content to the report by referencing it by id: `PUT /report` { 'report_id': `string` the report identifier 'content': `string` content to be added to the report. This can be one or more report entries in the format specified in df-000-base.md } The backend should validate the request to make sure it is a valid YAML Stream. New collectors should use the following format for updating reports: `POST /report/<report_id>` { content: `string` content to be added to the report. This can be one or more report entries in the format specified in df-000-base.md } ### 2.3.3 Closing a report This request is done by a probe to tell the backend that they have finished running the test and the report can be considered done: `POST /report/<report_id>/close` To create a new report a probe will peform an HTTP POST request to the resource /report. The collector MUST implement the following HTTP JSON RPC like API: /report ## 2.4 Report lifecycle When a report is created (section 2.3.1) it should be marked as NEW and a timestamp should be recorded. Once it is updated (section 2.3.2) it should be marked as ACTIVE. An ACTIVE report can be updated with new data. The collector must keep track of the last time a certain report is updated with new and valid data. A report is considered CLOSED when either the probe instructs the collector to close the report (section 2.3.3) or when a report is in ACTIVE state and has not been updated with valid data for more than 2 hours. ## 2.5 Report publishing and cleaning Once a report is closed it should be made available to the public for download and analysis. This shall happen as soon as a report reaches the CLOSED state. Reports should be discarded and deleted if: * They have been in the NEW state for more than 4 hours * They are CLOSED, but contain only one Report Entry meaning that the report entry contains only the base test data (see df-000-base.md). Reports should be published to: `https://ooni.torproject.org/reports/` **reportFormatVersion** `/` **CC** `/` Requesting such URL may also result in a 302 to the location of reports for that specific country. Where CC is the two letter country code as specified by ISO 31666-2. For example the reports for Italy (CC is it) of the reportVersion 0.1 may be found in: https://ooni.torproject.org/reports/0.1/IT/ This directory shall contain the various reports for the test using the following convention: test name - timestamp in ISO8601 format - probe AS number - probe|backend.yamloo The timestamp is expressed using ISO 8601 including seconds and with no : to delimit hours, minutes, days. Such date is the time in which the report was created and must be set by the backend. Like so: YEAR - MONTH - DAY T HOURS MINUTES SECONDS Z The time is always expressed in UTC. If a collision is detected then an int (starting with 1) will get appended to the test. For example if two report that are created on the first of January 2012 at Noon (UTC time) sharp from MIT (AS3) will be stored here: https://ooni.torproject.org/reports/0.1/US/http_test-2012-01-01T120000Z-AS3… https://ooni.torproject.org/reports/0.1/US/http_test-2012-01-01T120000Z-AS3… Implementation notes: The task of publishing a report should be made modular so that we can replace the publishing mechanism if we discover the limitations of this system (not infinite disk space). The basic implementation shall just scp the files to a machine that is configurable by config file. ?? Question: How does this integrate into the m-lab infrastructure? How will this work when some reports results are stored on m-lab and some are not? ## 2.6 Test helper collector relationship Some tests involve adding to the report also data that is collected by means of a test helper. This is the case in the two way traceroute test, where the report should include a traceroute also from the vantage point of the ooni backend. In these circumstances the report from the vantange point of the backend should be inside of a separate file that has the same name of the probe report but "-probe" should be replaced with "-backend". For example the backend part of the report for a traceroute test called `two_way_traceroute-2012-01-01T120000Z-AS3-probe.yamloo`, shall be called `two_way_traceroute-2012-01-01T120000Z-AS3-backend.yamloo` # 3.0 Test Helpers These are services exposed to ooniprobe clients that are of assistance to performing network measurements. # 3.1 System overview Probes will always receive as address of a test helper that of the one running on the same machine as the collector. They will only point to a test helper on a different machine if the test helper for the test the user is interested in running is not available on the desired machine. This can happen, for example, if the machine does not have two network interfaces with two differnet IP addresses. In this case the HTTP Return JSON Headers test helper cannot run at the same time as the TCP echo test helper (both bind to port 80). Some communication with the collector is required. This is the case of the two way traceroute test, where a multiport multiprotocol traceroute must also be performed from the backend to the probe. Test helpers are two kinds: * Reply: are test helpers that reply to requests from probes. For example HTTP test helpers are of this kind. * Active: are test helpers that actively perform requests towards the probe idepedently from probe requests. Implementation notes: Although I am talking about the collector as two differnet software components they both run inside of the same process and are part of the same piece of software. ## 3.2 Threat model (or non-goals) Because of the nature of the services that they are exposing it is not possible to guarantee end to end confidentiality and authentication of the data transmitted to and from test helpers. Moreover we are currently not making any particular effort to make test helpers look like something that they are not (i.e. make test helper traffic not look like test helper traffic). ## 3.3 Test Helper collector mapping When a report that requires a test helper is created with the collector component of oonib the test helper should be notified of the probes IP address (the probe_ip). This will allow the test helper to know from which IP address it should either expect the probe to come from or towards what IP address it should perform an active measurement. ## 3.4 Reply Test Helpers ### 3.4.1 HTTP Return JSON Headers This test helper will bind on port 80 and expect HTTP requests from a probe. It shall respond to every HTTP request with the HTTP Headers and HTTP request line as seen from the backend point of view. The response is structured in JSON as follows: { 'request_headers': [[HTTP header1 name, HTTP header1 value], [HTTP header2 name, HTTP header2 value]] the list is ordered based on how the headers were received. 'request_line': the value of the HTTP request line. 'headers_dict': `dict` containing as keys the HTTP header name (normalized) and as value a list containing the values of such header } For example: { 'request_headers': [['User-Agent', 'IE6'], ['Content-Length', 200]] 'request_line': 'GET / HTTP/1.1' 'headers_dict': {'User-Agent': ['IE6'], 'Content-Length': [200]} } ### 3.4.2 DNS Test Helper Shall provide a DNS resolver over UDP and TCP exposed on port 53. Such DNS resolver shall not filter any DNS query. ### 3.4.3 TCP Echo Helper This shall expose a TCP echo service that is bound to port 80. ## 3.5 Active Test Helpers ### 3.5.1 Two way traceroute This shall perform the ooniprobe traceroute test and attach the result to the final report as described in section 2.5.

1 0

transparent proxy detection
by Sam Smith 06 Mar '13

06 Mar '13

Hey all, I'm looking at detection and identification of some transparent proxies (of different kinds). Has anyone already got tests that effectively but generically merge manipulation/http_host and experimental/squid.py ? Also, I'm testing on a debian (6.0) VM running in a parallels 8 on OS X. Ooni successfully runs tests once , and then requires a debian reboot in order to run again (especially http_host, it was less repeatable with others). I have no idea what's going on, and it'll be a pain to debug, but it's the sort of thing someone's probably interested in for other purposes ;) thanks for ooni Best Wishes Sam -- @smithsam

2 1

Building Tor Browser Bundle on Windows
by Tom Ritter 05 Mar '13

05 Mar '13

This weekend I tried building several of the tor projects on Windows (tor, vidalia, tbb, and vanilla firefox). I kept notes of my adventures, some of the quirks I ran into, and the final set of instructions that seemed to work for me. Perhaps most usefully, I've created an Amazon AMI that anyone will be able to boot up and use. (Yes, this has trust issues, I've addressed them in the top of the README document attached.) The intention is that people who want to test a patch or develop a patch can use this to bootstrap themselves, without having to fight long and hard to set up a Windows build environment. I've attached two documents: 1) TBB Environment README.txt 2) Adventures in Compilation.txt The first is the README for the environment. The second is a journal of my trying to figure out what to do. Specifically I'm going to call out several issues. If desired, I can submit patches to address them, and they can be reviewed. I understand that documentation is usually a lower priority than actually shipping software, please take these comments not as bitchy criticism, but instead a list of things I'd like to improve, if someone can review my suggestions and shepard me a little. 1) Firefox's official build environment is VS2010 while TBB's is VS2008 I'm not 100% sure, but it seems like it'd be relatively easy to switch TBB over to 2010. There may be some issues. But it seems like it'd be good to track FF's official build env. I ran across at least 1 Vanilla FF issue that broke in 2008, and there seemed to be a few in the bugtracker. 2) Vidalia's build environment instructions contradict TBB's https://gitweb.torproject.org/vidalia.git/blob/HEAD:/INSTALL https://gitweb.torproject.org/torbrowser.git/blob/HEAD:/docs/buildmachine_s… Vidalia's says you need CMake in your PATH, TBB's says you don't. I think it can be in your PATH. 3) There's no explicit instructions on how to build Tor in Windows It seems like you just build it in MinGW? It worked anyway. It's a (minor) bitch to get the components built and placed in the 'correct way and place' for the MinGW toolchain. (Now documented in my README) 4) The TorBrowser build instructions are really, really bad. https://gitweb.torproject.org/torbrowser.git/blob/HEAD:/docs/buildmachine_s… This is pretty good. But it just ends abruptly, and doesn't tell you want to do. https://gitweb.torproject.org/torbrowser.git/blob/HEAD:/docs/HACKING This document seems to be mostly up to date, although I think the FF Extensions it lists have been changed since. https://gitweb.torproject.org/torbrowser.git/blob/HEAD:/build-scripts/INSTA… This one is super out of date. - You don't need subversion or winrar - It talks a lot about getting FirefoxPortable (or built a custom Firefox) - I didn't try following the instructions for MinGW, msys, cmake, qt, msysGTK, or autoconf - since I had those already. It seems these sections have been subsumed by the windows buildmachine document - The OpenSSL instructions do not match the instructions IN OpenSSL - Vidalia's links are way out of date and dead - Its instructions for Vidalia don't match Vidalia's - It talks about PidginPortable? I think that's been nixed... - "Currently the Tor Browser Bundle uses FirefoxPortable binaries." - It talks about building with MSVC 7.1 (Visual Studio 2003) - It stops short of telling you how to actually build the bundle, probably because the makefiles are newer than this document https://gitweb.torproject.org/torbrowser.git/blob/HEAD:/build-scripts/DEPLO… This doesn't seem applicable at all anymore I eventually found (by searching my email spools) the magic incantation to kick it off. The "TorBrowser" section of Adventures in Compilation.txt shows my hiccups and luck getting it going. Finally, after all this.... tbb-firefox crashes. I don't know why. I don't know if it's because I'm using VS2010, or my msvc*.dll swaps. Specifically it's crashing here: c:\build\torbrowser\build-scripts\build-alpha-windows\build\firefox-17.0.3esr\content\xul\templates\src\nsrulenetwork.h class Iterator : public ConstIterator { public: Iterator(ReteNode** aNode) : ConstIterator(aNode) {} Iterator& operator++() { ++mCurrent; return *this; } Iterator operator++(int) { Iterator result(*this); ++mCurrent; return result; } ReteNode* operator*() const { return *mCurrent; } <========================================= ReteNode* operator->() const { return *mCurrent; } bool operator==(const ConstIterator& aConstIterator) const { return mCurrent == aConstIterator.mCurrent; } bool operator!=(const ConstIterator& aConstIterator) const { return mCurrent != aConstIterator.mCurrent; } }; I'm not quite sure where to start figuring out *why* it's dereferencing a null ptr. The windbg output is in the bottom of both docs. The AMI for the EC2 instance is ami-2e36ab47 - when you start it, open ports 3389 and 8080 in the firewall for 0.0.0.0/0 (or just your IP address if you want.) If you try it, and get skeeved out by them asking for your SSH private key to get the password, check out https://github.com/tomrittervg/decrypt-windows-ec2-passwd -tom

5 5

Damian's Status Report - February 2013
by Damian Johnson 02 Mar '13

02 Mar '13

Hi all. Between being a short month and oncall for work I didn't get as much done as I'd like. What time I did have for tor mostly went into stem's descriptor functionality. In particular... ======================================== * Microdescriptor Support Stem can now read and parse microdescritpors (#8253), with controller methods coming later this weekend. I understand the desire for lightweight descriptors but they're a step backward for controllers. Their lack of fingerprints make them clunky to use (https://trac.torproject.org/8323#comment:2) and tor lacks the usual methods for retrieving them (#8323) and v3 network status information (#7953). Controllers will often need to read descriptor content from the data directory until those are fixed. * Invalid descriptor content within archives caused the reader to stop processing content from the archive. This bug is simple in retrospect but cost me around a week of hair pulling frustration to sort out. Thanks to Karsten for catching it! (#8049) * Descriptor readers can now optionally provide network status documents rather than the entries they contain. Feature request by Karsten. (#8050) * Calling str() on Descriptors choked if it contained unicode content. Caught by Sathyanarayanan. (#8265) * Thanks to Karsten Descriptors now provide hex digests. (#8036) * Discussed the new 'flag-thresholds' attribute and added support for it to stem. (#8165) * Descriptor parsers that used readline() could choke if derived from a descriptor archive. Caught by Karsten. ======================================== General tasks included... * Discussed proposal 218 with Karsten on tor-dev@... https://lists.torproject.org/pipermail/tor-dev/2013-February/004411.html * Changed our consensus-tracker script to alarm for non-exits (we had an undetected sybil attack early in the month). Also fixed an issue where the script gobbled up way too much memory. (#7831} * Made a few backward incompatible changes to improve stem's usability in anticipation of our March API freeze... * Version comparison is now done through normal comparison operators rather than a meets_requirements() method. * Renamed the keyword arguments for Controller.from_port() and others to be less verbose (for instance 'control_port' to just 'port'). * Dropped the 'path' arg from parse_file(), it was never intended for external callers. * Variety of bug fixes... * We didn't recognize a 'NEVER' date in ADDRMAP events. Caught by Desoxy. {#8162) * Patch from Abhishek so our tests avoid static /tmp usage. (#7926) * Added copyright notices throughout most of our codebase. Suggested by Juan. (#7954) * Addressed issues with get_process_name() on OSX. Caught by Sathyanarayanan. (#8266) Cheers! -Damian

1 0

The Tor git master branch is now 0.2.5.0-alpha-dev
by Nick Mathewson 01 Mar '13

01 Mar '13

Hi, folks! The Tor git master branch is now 0.2.5.0-alpha-dev. Development on 0.2.4.x continues in the branch "maint-0.2.4". I expect that the next alpha will be the last 0.2.4.x-alpha, and then we can move on to beta and rc. We now return you to your semiregularly semischeduled Tor development. yrs, -- Nick

1 0

Interest in Contributing to Tor
by kaushik s 28 Feb '13

28 Feb '13

Hi, I am a junior student at International Institute of Information Technology, Hyderabad with major in Computer Science and Security, and I am very interested in working for your organization this summer and further. I have a strong background in information security and algorithms. I strongly believe in the cause that you are fighting for - free/open Internet for all, and would like to support you by contributing to the code. I have been through the paper by Roger Dingledine and Nick Mathewson, "Design of a blocking-resistant anonymity system" and your work aroused my interest. I am trying to build up my knowledge in the field of information security with some hands-on experience, through projects. The paper by Dingledine, Mathewson had a lot of proposals for making Tor blocking-resistant, but in your list of proposed projects I only found a project for implementing a HTTPS server in the list of project ideas. What is the current status of implementation of ideas listed? I would like to contribute by into the field of algorithms and cryptography by implementing more ideas to make it even more blocking-resistant. Please let me know what are the projects and ideas having maximum priority , so that I can start working on them right away. Thanks & Regards, Kaushik Srinivasan, UG3, B.tech CSE, IIIT Hyderabad.

2 1

Re: [tor-dev] Proposal: Controller events to better understand connection/circuit usage
by Karsten Loesing 28 Feb '13

28 Feb '13

[Nick, can you merge my torspec proposal218 branch, please? Thanks!] On 2/28/13 2:08 AM, Rob Jansen wrote: > On Mon, Feb 25, 2013 at 10:28 AM, Karsten Loesing <karsten(a)torproject.org> > wrote: > >> On 2/23/13 11:20 PM, Rob Jansen wrote: >>> On Feb 23, 2013 4:22 PM, "Karsten Loesing" <karsten(a)torproject.org> >> wrote: >>>> Your understanding of n_circ_id and p_circ_id matches mine, but are you >>>> sure there's a UID for circuits other than origin circuits? I think you >>>> mean origin_circuit_t->global_identifier. But there's no such field for >>>> or_circuit_t or circuit_t. Or do you mean something else? >>>> >>> Ok. Though I thought my original patch moved the global Id to the base >>> circuit struct. Perhaps I didn't. Anyway, I'm not sure it matters... >> >> Your original patch did move the ID to circuit_t, but I thought we >> wanted to avoid numbering non-origin circuits (mostly because that >> affects relays in non-TestingTorNetwork mode and could lead to busy >> relays running out of IDs at some point), which is why I took this >> change out. >> > > Right, I remember this now. I could imagine ways to get around the 'running > out of ids' problem, like resetting the id counter after a given timeframe. > In fact, we could just let the counter overflow and loop back to 0 on its > own (assuming its a unsigned int type) since we really only need them to be > unique approximately for the life of a circuit. If we see the ID come up > again after an hour, we can assume its a new circuit. I'd rather not want to change behavior in non-simulation mode. If we really need a UID for non-origin circuits, we could add a separate uint64_t global_identifier to circuit_t and only use that in simulating mode. I'm not sure that we need it though. >> Also, even if we moved the field to circuit_t, the new CELL_STATS events >> would be the only ones using these UIDs, because all other events are >> for origin circuits only. I don't see how these IDs would help us. We >> never learn what UID the next or previous node in a circuit picks for a >> given circuit. > > Not currently, but couldn't we implement the functionality where relays log > or export their circuit UIDs and next/prev IDs over the control port? > Though I'm not sure if you'd want this in mainline Tor if its only useful > in simulation mode... We could have relays log local circuit UIDs together with p_circ_id, p_conn_id, n_circ_id, and n_conn_id in simulation mode. But I don't see how that would facilitate circuit tracking compared to the current approach using ORCONN and CELL_STATS events. Here's an example: - fileclient creates a circuit with - UID 14, - n_conn_id 15, and - n_circ_id 19403. - tokenglobal is the first hop in this circuit and reports - (new) UID 12345, - p_conn_id 32, - p_circ_id 19403, - n_conn_id 18, and - n_circ_id 6710. - tokenrelay is the second hop and reports - (new) UID 23456, - p_conn_id 17, - p_circ_id 6710, - n_conn_id 16, - n_circ_id 34402. - exit2 is the third and final hop and reports - (new) UID 34567, - p_conn_id 15, and - p_circ_id 34402. We need ORCONN events to know that fileclient's n_conn_id 15 is the same connection as tokenglobal's p_conn_id 32. How would the new UIDs make this easier? >>>> tl;dr: I _think_ it's possible to reconstruct circuits from ORCONN and >>>> CELL_STATS events as they are currently specified in proposal 218. >>>> >>> Great, but do we really expect every Tor controller parser to get this >>> right? It seems complicated enough that there should be an easier way. >>> Maybe it's just wishful thinking on my part. >> >> I agree that reconstructing circuits from ORCONN and CELL_STATS events >> is far from trivial. I don't really see how to make it simpler though. > > What about linking all of the IDs and UIDs as described above? (See above.) >> From an earlier mail in this thread: >>>> Finally, Rob, should I look into CIRC_BW events you suggested a while >>>> ago? If yes, what did you have in mind how that event would look like, >>>> and when/by whom would it be emitted? >>> >>> If we want to do this, it would likely be an aggregation of all STREAM_BW >>> events for a circuit, but only during the time when those streams >> belonged >>> to that circuit. I don't think it makes sense to emit it for every >>> STREAM_BW event though, so what if we aggregate and emit it once per >>> second? A format similar to the STREAM_BW format should work fine. >> >> Done. I specified and implemented such a CIRC_BW event. >> >> > Great! > > >> >> Here's the updated proposal 218 (Nick, please don't merge this yet): >> >> >> https://gitweb.torproject.org/user/karsten/torspec.git/blob/refs/heads/prop… > > > In section 5.3/5.4/5.5, these events are emitted in the > second_elapsed_callback(), right? I wanted to verify that a relay who > hasn't sent anything in a few seconds and then starts sending again will > emit the event at the end of the second after which it resumed sending, > rather than the first bytes after it resumed sending. Yes, all these events are emitted in second_elapsed_callback(). > The last word in 5.4 should be 'reading' instead of 'read'. Fixed. > Is the specification of 5.5 and 5.6 complex enough to warrant including > example outputs? Sure, can't hurt. Added a few examples. > In 5.6, were we planning on explaining how buckets can go negative and how > that affects the reporting of the TB_EMPTY events? I tried a better explanation: """ ReadBucketEmpty (WriteBucketEmpty) is the time in millis that the read (write) bucket was empty since the last refill. LastRefill is the time in millis since the last refill. If a bucket went negative and if refilling tokens didn't make it go positive again, there will be multiple consecutive TB_EMPTY events for each refill interval during which the bucket contained zero tokens or less. In such a case, ReadBucketEmpty or WriteBucketEmpty are capped at LastRefill in order not to report empty times more than once. """ > Here's the tor branch: >> >> >> https://gitweb.torproject.org/karsten/tor.git/shortlog/refs/heads/morestats3 >> >> Here's a Shadow log file containing all new events: >> >> https://people.torproject.org/~karsten/volatile/scallion.log.gz >> >> Here's the Java program that I used to parse the Shadow log file: >> >> https://people.torproject.org/~karsten/volatile/ParseProposal218Events.java >> >> > Ugh. I really don't look forward to writing parsers for this. I guess there > may be few projects that actually require this information, and those that > do can use your code:) I hope that some of the complexity goes away once we use a parsing library like Stem. And I think we should provide parsing code to other people looking into this. >> And finally, here's the output, which should be easier to understand now: >> >> https://people.torproject.org/~karsten/volatile/scallion.txt >> >> Search for "Circuit [fileclient-60.1.0.0]:14" to find the circuit I >> mentioned earlier in this thread. >> >> >> Can you review the proposal changes and tell me if they make sense to you? >> >> Best, >> Karsten >> >> > See comments above. Overall, it looks good. I'm still wondering about the > UIDs / IDs issue. It may be that we don't want to include that for other > reasons, in which case the current implementation is fine. Okay, in that case let's consider proposal 218 done for the moment, unless we come up with a better idea to solve circuit-tracking thing. I asked Nick above to merge my changes, so that I can put proposal 218 on the sponsor F year 3 wiki page as one result of the February 28 milestone. (That doesn't mean we cannot make it even better after February.) Thanks! Karsten

2 1

Re: [tor-dev] Proposal: Controller events to better understand connection/circuit usage
by Karsten Loesing 25 Feb '13

25 Feb '13

On 2/23/13 11:20 PM, Rob Jansen wrote: > On Feb 23, 2013 4:22 PM, "Karsten Loesing" <karsten(a)torproject.org> wrote: >> Your understanding of n_circ_id and p_circ_id matches mine, but are you >> sure there's a UID for circuits other than origin circuits? I think you >> mean origin_circuit_t->global_identifier. But there's no such field for >> or_circuit_t or circuit_t. Or do you mean something else? >> > Ok. Though I thought my original patch moved the global Id to the base > circuit struct. Perhaps I didn't. Anyway, I'm not sure it matters... Your original patch did move the ID to circuit_t, but I thought we wanted to avoid numbering non-origin circuits (mostly because that affects relays in non-TestingTorNetwork mode and could lead to busy relays running out of IDs at some point), which is why I took this change out. Also, even if we moved the field to circuit_t, the new CELL_STATS events would be the only ones using these UIDs, because all other events are for origin circuits only. I don't see how these IDs would help us. We never learn what UID the next or previous node in a circuit picks for a given circuit. >> tl;dr: I _think_ it's possible to reconstruct circuits from ORCONN and >> CELL_STATS events as they are currently specified in proposal 218. >> > Great, but do we really expect every Tor controller parser to get this > right? It seems complicated enough that there should be an easier way. > Maybe it's just wishful thinking on my part. I agree that reconstructing circuits from ORCONN and CELL_STATS events is far from trivial. I don't really see how to make it simpler though. >From an earlier mail in this thread: >> Finally, Rob, should I look into CIRC_BW events you suggested a while >> ago? If yes, what did you have in mind how that event would look like, >> and when/by whom would it be emitted? > > If we want to do this, it would likely be an aggregation of all STREAM_BW > events for a circuit, but only during the time when those streams belonged > to that circuit. I don't think it makes sense to emit it for every > STREAM_BW event though, so what if we aggregate and emit it once per > second? A format similar to the STREAM_BW format should work fine. Done. I specified and implemented such a CIRC_BW event. Here's the updated proposal 218 (Nick, please don't merge this yet): https://gitweb.torproject.org/user/karsten/torspec.git/blob/refs/heads/prop… Here's the tor branch: https://gitweb.torproject.org/karsten/tor.git/shortlog/refs/heads/morestats3 Here's a Shadow log file containing all new events: https://people.torproject.org/~karsten/volatile/scallion.log.gz Here's the Java program that I used to parse the Shadow log file: https://people.torproject.org/~karsten/volatile/ParseProposal218Events.java And finally, here's the output, which should be easier to understand now: https://people.torproject.org/~karsten/volatile/scallion.txt Search for "Circuit [fileclient-60.1.0.0]:14" to find the circuit I mentioned earlier in this thread. Can you review the proposal changes and tell me if they make sense to you? Best, Karsten

1 0