400 bad request on cowboy branch

Question

400 bad request on cowboy branch

simonmacmullen opened this issue 13 years ago · 17 comments

Taken from the comments on commit 95b8c7a, making into an issue to make things a bit clearer.

essen: Hello! Cowboy author here, got linked to this commit. Did you find out what was the issue and is there anything I can do to help?

simonmacmullen: Hi essen, thanks for commenting! No, I haven't had any further time to investigate this and try to strip down to a more minimal test case or (more likely) figure out what the hell I'm doing wrong.

If you feel really energetic you could try to run it yourself; in the qunit tests there are lots of failures due to Cowboy returning 400 before my code gets a look in. If not I'll try to strip things down and make this more replicable next week.

essen: Sounds like it could be Cowboy indeed. I'll look later today. Can you tell me what browser you used to run the qunit tests though?

simonmacmullen: Chromium 11.0.696.68 (84545) Ubuntu 10.04, but I just tested with FF6 and got the same.

If you do try:

I apologise for the rough nature of the build system and tests
There will be bugs in my code that cause some tests to fail. "xhr-streaming: echo2" is an example of a test that fails in the way we're talking about here.
I stuck some io:formats in cowboy_http_protocol and it seems like the buffer in the state record contains the tail of a request somehow that gets carried over into the next request in next_request/3. But I have no idea how that module is supposed to work.

simonmacmullen commented 13 years ago

Thanks!

Answer 1 · 2011-09-30T15:04:44.000Z

Simon, I'm trying to reproduce that, but I'm not sure how to run the cowboy branch:

$ cd sockjs-erlang
$ git branch -f cowboy origin/cowboy
$ git checkout cowboy
$ make
$ make test
[...]
coffee -o tests/html/lib/ -c --bare tests/html/src/tests.coffee
make[1]: Leaving directory `/tmp/sockjs-erlang/deps/sockjs-client'
make -C deps/misultin
make[1]: Entering directory `/tmp/sockjs-erlang/deps/misultin'
make[1]: rebar: Command not found
make[1]: *** [compile] Error 127
make[1]: Leaving directory `/tmp/sockjs-erlang/deps/misultin'
make: *** [test-prep] Error 2

Answer 2 · 2011-09-30T15:43:13.000Z

Well, you need to install rebar. And probably a few other things.

Answer 3 · 2011-09-30T15:43:27.000Z

Gah, misclick.

Answer 4 · 2011-09-30T15:55:23.000Z

Thanks, copying rebar to bin does solve the problem.

Answer 5 · 2011-09-30T15:56:59.000Z

Right, steps to reproduce.

make test on proper branch
run tcpdump in the background, for example sudo tcpdump -ni any -s0 -A port 8080
Open chrome and type: http://127.0.0.1:8080/tests-qunit.html?filter=xhr-streaming%3A%20echo2
Look at tcpdump:

HTTP/1.1 408 Request Timeout
Connection: close
Content-Length: 0
Date: Fri, 30 Sep 2011 15:54:50 GMT
Server: Cowboy

For completeness: we don't use 408 at any point in our code.

Answer 6 · 2011-09-30T16:01:59.000Z

I may be wrong, but it looks like there are multiple 408 responses on a single connection. Ouch.

Answer 7 · 2011-09-30T16:07:08.000Z

No, that's not it majek!

Due to the somewhat limited nature of the test code (yes, yes, it's still very young) you have to use http://localhost:8080/tests-qunit.html?filter=xhr-streaming%3A%20echo2 (i.e. localhost not 127.0.0.1)

Then you should see:

  HTTP/1.1 400 Bad Request
  Connection: close
  Content-Length: 0
  Date: Fri, 30 Sep 2011 16:00:23 GMT
  Server: Cowboy

If you put io:format("Buffer: ~p~n", [Buffer]), at the beginning of cowboy_http_protocol:parse_request/1 you'll see it try to parse a malformed HTTP request that does not appear to be what tcpdump sees.

Answer 8 · 2011-09-30T16:11:17.000Z

Right, in the localhost case I can see one connection getting

first 204
than 400

And second connection getting 408. Something is clearly wrong somewhere.

Answer 9 · 2011-09-30T16:13:48.000Z

Posting to get notice on this issue. Will look this week-end.

Answer 10 · 2011-10-03T07:52:15.000Z

Didn't have time this week-end, sorry. I'll ping when I managed to take a look.

Answer 11 · 2011-10-03T15:28:26.000Z

So I've tried to run make test and found out I need to install npm and nodejs to run it. Is there no way around this? I don't really want Node.

Answer 12 · 2011-10-03T15:30:22.000Z

Not at the moment I'm afraid. I'm aware this is very far from a minimal test case; I'll try to cut it down.

Answer 13 · 2011-10-03T15:42:56.000Z

OK, try the branch cowboy-no-node-hack. It just contains all the stuff node builds checked in directly.

Answer 14 · 2011-10-03T15:59:37.000Z

Sounds like you have the same issue as in ninenines/cowboy#64

Good for me as I now have a test case to run against. ;)

I'll keep you informed.

Answer 15 · 2011-10-03T17:49:22.000Z

You return the wrong Req object. In sockjs_cowboy_handler line 11 you get Req2 and then you return Req1 line 19, should be Req2. After that the tests crash but you have a proper error.

Answer 16 · 2011-10-04T09:33:11.000Z

Argh, now I feel like an idiot. Thanks!