| Author |
Message |
|
| Guest |
 Posted: Tue Jun 01, 2010 9:23 pm |
 |
|
|
Guest
|
Hello,
I've tried to use lhttpc library (http://bitbucket.org/etc/lhttpc) to fetch
a resource (http://www.qype.com/review/1376848) and got the following
error:
{{http_error,"HTTP/1.1 200\r\n"},
[{lhttpc_client,read_response,5},
{lhttpc_client,execute,8},
{lhttpc_client,request,9}]}
I've checked lhttpc source code and found out that to receive and parse an HTTP
response it uses _standard_ erlang module gen_tcp on a socket in
{packet, http} mode. So it looks like the {http_error,"HTTP/1.1 200\r\n"} error was
in fact generated by erlang's http packet parsing code.
I found the following code in packet_parse_http function from
erts/emulator/beam/packet_parser.c file:
...
p0 = ptr;
while (n && SP(ptr)) {
ptr++; n--;
}
if (ptr==p0) return -1;
...
As far as I understand "HTTP/1.1 200\r\n" line does not have any spaces
after the status code "200", and the function strips \r\n as a first step of
its operation. So the "while" cycle does not run and we get into the
"if (ptr==p0) branch" this basically leads to returning of
{http_error, "HTTP/1.1 200\r\n"} atom up to the call stack.
Strictly speaking this is not a bug in erlang, but I suppose it
should take a more relaxed approach to HTTP Status Line parsing
and not return http_error if an HTTP response Status Line does not have
a Reason-phrase part.
________________________________________________________________
erlang-bugs (at) erlang.org mailing list.
See http://www.erlang.org/faq.html
To unsubscribe; mailto:erlang-bugs-unsubscribe@erlang.org
Post received from mailinglist |
|
|
| Back to top |
|
| Guest |
| Posted: Tue Jun 01, 2010 9:49 pm |
|
|
|
Guest
|
On Wed, Jun 02, 2010 at 01:22:29AM +0400, Alexander Zhuravlev wrote:
> Hello,
>
> I've tried to use lhttpc library (http://bitbucket.org/etc/lhttpc) to fetch
> a resource (http://www.qype.com/review/1376848) and got the following
> error:
>
> {{http_error,"HTTP/1.1 200\r\n"},
> [{lhttpc_client,read_response,5},
> {lhttpc_client,execute,8},
> {lhttpc_client,request,9}]}
Almost forgot, the error was reproduced with erlang R13B04:
Erlang R13B04 (erts-5.7.5) [source] [64-bit] [smp:2:2] [rq:2] [async-threads:0] [hipe] [kernel-poll:false]
lhttpc version 1.2.4
> I've checked lhttpc source code and found out that to receive and parse an HTTP
> response it uses _standard_ erlang module gen_tcp on a socket in
> {packet, http} mode. So it looks like the {http_error,"HTTP/1.1 200\r\n"} error was
> in fact generated by erlang's http packet parsing code.
>
> I found the following code in packet_parse_http function from
> erts/emulator/beam/packet_parser.c file:
>
> ...
> p0 = ptr;
> while (n && SP(ptr)) {
> ptr++; n--;
> }
> if (ptr==p0) return -1;
> ...
>
> As far as I understand "HTTP/1.1 200\r\n" line does not have any spaces
> after the status code "200", and the function strips \r\n as a first step of
> its operation. So the "while" cycle does not run and we get into the
> "if (ptr==p0) branch" this basically leads to returning of
> {http_error, "HTTP/1.1 200\r\n"} atom up to the call stack.
>
> Strictly speaking this is not a bug in erlang, but I suppose it
> should take a more relaxed approach to HTTP Status Line parsing
> and not return http_error if an HTTP response Status Line does not have
> a Reason-phrase part.
--
Alexander Zhuravlev
________________________________________________________________
erlang-bugs (at) erlang.org mailing list.
See http://www.erlang.org/faq.html
To unsubscribe; mailto:erlang-bugs-unsubscribe@erlang.org
Post received from mailinglist |
|
|
| Back to top |
|
| Guest |
| Posted: Wed Jun 02, 2010 10:10 am |
|
|
|
Guest
|
Alexander Zhuravlev wrote:
> Hello,
>
> I've tried to use lhttpc library (http://bitbucket.org/etc/lhttpc) to fetch
> a resource (http://www.qype.com/review/1376848) and got the following
> error:
>
> {{http_error,"HTTP/1.1 200\r\n"},
> [{lhttpc_client,read_response,5},
> {lhttpc_client,execute,8},
> {lhttpc_client,request,9}]}
>
> I've checked lhttpc source code and found out that to receive and parse an HTTP
> response it uses _standard_ erlang module gen_tcp on a socket in
> {packet, http} mode. So it looks like the {http_error,"HTTP/1.1 200\r\n"} error was
> in fact generated by erlang's http packet parsing code.
>
> I found the following code in packet_parse_http function from
> erts/emulator/beam/packet_parser.c file:
>
> ...
> p0 = ptr;
> while (n && SP(ptr)) {
> ptr++; n--;
> }
> if (ptr==p0) return -1;
> ...
>
>
A change to
if (ptr==p0 && n>0) return -1;
would do it, right?
/Sverker, Erlang/OTP
> As far as I understand "HTTP/1.1 200\r\n" line does not have any spaces
> after the status code "200", and the function strips \r\n as a first step of
> its operation. So the "while" cycle does not run and we get into the
> "if (ptr==p0) branch" this basically leads to returning of
> {http_error, "HTTP/1.1 200\r\n"} atom up to the call stack.
>
> Strictly speaking this is not a bug in erlang, but I suppose it
> should take a more relaxed approach to HTTP Status Line parsing
> and not return http_error if an HTTP response Status Line does not have
> a Reason-phrase part.
>
> ________________________________________________________________
> erlang-bugs (at) erlang.org mailing list.
> See http://www.erlang.org/faq.html
> To unsubscribe; mailto:erlang-bugs-unsubscribe@erlang.org
>
>
________________________________________________________________
erlang-bugs (at) erlang.org mailing list.
See http://www.erlang.org/faq.html
To unsubscribe; mailto:erlang-bugs-unsubscribe@erlang.org
Post received from mailinglist |
|
|
| Back to top |
|
| Guest |
| Posted: Wed Jun 02, 2010 7:36 pm |
|
|
|
Guest
|
On Wed, Jun 2, 2010 at 14:09, Sverker Eriksson <sverker@erix.ericsson.se> wrote:
> Alexander Zhuravlev wrote:
>>
>> Hello,
>>
>> I've tried to use lhttpc library (http://bitbucket.org/etc/lhttpc) to
>> fetch
>> a resource (http://www.qype.com/review/1376848) and got the following
>> error:
>>
>> {{http_error,"HTTP/1.1 200\r\n"},
>> |
|
|
| Back to top |
|
| Guest |
| Posted: Thu Jun 03, 2010 9:39 am |
|
|
|
Guest
|
Alexander Zhuravlev wrote:
> On Wed, Jun 2, 2010 at 14:09, Sverker Eriksson <sverker@erix.ericsson.se> wrote:
>
>> Alexander Zhuravlev wrote:
>>
>>> Hello,
>>>
>>> I've tried to use lhttpc library (http://bitbucket.org/etc/lhttpc) to
>>> fetch
>>> a resource (http://www.qype.com/review/1376848) and got the following
>>> error:
>>>
>>> {{http_error,"HTTP/1.1 200\r\n"},
>>> [{lhttpc_client,read_response,5},
>>> {lhttpc_client,execute,8},
>>> {lhttpc_client,request,9}]}
>>> I've checked lhttpc source code and found out that to receive and parse an
>>> HTTP
>>> response it uses _standard_ erlang module gen_tcp on a socket in
>>> {packet, http} mode. So it looks like the {http_error,"HTTP/1.1 200\r\n"}
>>> error was
>>> in fact generated by erlang's http packet parsing code.
>>>
>>> I found the following code in packet_parse_http function from
>>> erts/emulator/beam/packet_parser.c file:
>>>
>>> ...
>>> p0 = ptr;
>>> while (n && SP(ptr)) {
>>> ptr++; n--;
>>> }
>>> if (ptr==p0) return -1;
>>> ...
>>>
>>>
>>>
>> A change to
>>
>> if (ptr==p0 && n>0) return -1;
>>
>> would do it, right?
>>
>
> Yes, probably. But I suppose that fact that the string does not have a
> phrase string may cause
> other issues with this call in the packet_parse_http function:
>
> return pcb->http_response(arg, major, minor, status,
> ptr, n);
>
> ptr will point to the end of the string and n will be equal to 0
No, that will work. You will get an empty phrase string as part of the
http_response-tuple.
/Sverker, Erlang/OTP
________________________________________________________________
erlang-bugs (at) erlang.org mailing list.
See http://www.erlang.org/faq.html
To unsubscribe; mailto:erlang-bugs-unsubscribe@erlang.org
Post received from mailinglist |
|
|
| Back to top |
|
|
|
All times are GMT
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum
|
|
|
Digg It
Del.icio.us
Reddit
Facebook
Stumble Upon
Technorati
