HTTP parser fails if server returns no headers #1711

davglass · 2011-09-15T15:42:59Z

I was doing some low-level scraping on a few of my devices (Cable Modem, X10 system, ADT alarm system) and noticed that all of these embedded devices return no headers in their http responses. It returns a status code, but no headers. With no headers being sent, the Node HTTP parser fails (silently in 0.4.11 and with a parse error in 0.5.x)

Here is a repro case:
https://gist.github.com/1217143

I couldn't find an entry in the spec that "required" headers to be sent from the server, but I feel that the parser shouldn't choke if no headers are returned, since curl/wget/links all work as expected.

ry · 2011-09-15T17:25:20Z

Responding from a server with

HTTP/1.1 200 OK\r\n\r\n<html><head><title></title></head><body></body></html>

Is invalid HTTP.

When the parser reaches the end of the CRLFCRLF it has two ways of interpreting this message: first that it has no content and the next character begins the next message or that the user agent should consider the rest of the connection to be the body terminated by EOF.

HTTP/1.1 servers default to Connection: keep-alive and therefore the user agent considers this to be a zero length message to be soon followed by another HTTP response.

The relevant branch in http-parser is https://github.com/ry/http-parser/blob/c0ecab0516147401b5fd02a2272ebfb5dce8deb4/http_parser.c#L1564-1571 and here https://gist.github.com/8d854170ac16c39fdc74 is a test I was using to determine this.

@mnot am I correct or should this be interpreted as a zero-length message?

davglass · 2011-09-15T22:34:06Z

@ry I Thought that too, but reading this:

http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4

"Both types of message consist of a start-line, zero or more header fields (also known as "headers"), an empty line (i.e., a line with nothing preceding the CRLF) indicating the end of the header fields, and possibly a message-body"

That made me think that headers are optional since it's worded as "zero or more".

ry · 2011-09-15T22:44:47Z

@davglass headers are indeed optional but you will need either a Transfer-Encoding or a Content-Length or a Connection: close in order to have a response with a body using HTTP/1.1. The response

HTTP/1.1 200 OK\r\n\r\n

is valid

mnot · 2011-09-16T00:50:49Z

See:
http://tools.ietf.org/html/draft-ietf-httpbis-p1-messaging-16#section-3.3

The relevant rule is the catch-all;

Otherwise, this is a response message without a declared message-
body length, so the message-body length is determined by the
number of octets received prior to the server closing the
connection.

I.e., it's all body.

c4milo · 2011-09-16T01:42:00Z

See also: http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.4 point 5.
That's what curl actually does: https://github.com/bagder/curl/blob/master/lib/http.c#L2831

camilo@imacsita:~> curl -vvvv http://localhost:8500

About to connect() to localhost port 8500 (#0)
Trying 127.0.0.1... connected
Connected to localhost (127.0.0.1) port 8500 (#0)

GET / HTTP/1.1
User-Agent: curl/7.21.6 (x86_64-apple-darwin10.7.0) libcurl/7.21.6 OpenSSL/1.0.0d zlib/1.2.5 libidn/1.22
Host: localhost:8500
Accept: /

< HTTP/1.1 200 OK
no chunk, no close, no size. Assume close to signal end
<
Closing connection #0 <title></title>camilo@imacsita:~>

pstadler · 2011-10-03T10:57:45Z

I've got the same problem. Receiving HTTP/0.9 200 OK without headers. curl output:

curl -vvvv http://domain.tld:5222
* About to connect() to domain.tld port 5222 (#0)
*   Trying x.x.x.x... connected
* Connected to domain.tld (x.x.x.x) port 5222 (#0)
> GET / HTTP/1.1
> User-Agent: curl/7.21.4 (universal-apple-darwin11.0) libcurl/7.21.4 OpenSSL/0.9.8r zlib/1.2.5
> Host: domain.tld:5222
> Accept: */*
> 
* Connection #0 to host domain.tld left intact
* Closing connection #0
<?xml version='1.0'?><stream:stream xmlns='jabber:client' xmlns:stream='http://etherx.jabber.org/streams' id='0123456789' from='domain.tld' version='1.0'><stream:error><xml-not-well-formed xmlns='urn:ietf:params:xml:ns:xmpp-streams'/></stream:error></stream:stream>

Node.js:

Error: Parse Error
    at Socket.ondata (http.js:1231:22)
    at Socket._onReadable (net.js:677:27)
    at IOWatcher.onReadable [as callback] (net.js:177:10)

dazagrohovaz · 2011-11-17T11:03:34Z

hi everybody,
response "HTTP/1.0 200 Connection established\r\n\r\n" could not be parsed either...
other issue like this:
#1956

regards

c4milo · 2011-11-17T14:45:06Z

is this still happening with nodejs 0.6.1, I haven't try it out.

bnoordhuis · 2011-11-17T15:17:37Z

Confirmed. A HTTP/1.0 response body without headers works, a HTTP/0.9 response does not.

HTTP/0.9 - fails with a parse error HTTP/1.0 - works HTTP/1.1 - fails with an empty response body See #1711.

bnoordhuis · 2011-11-17T15:33:54Z

(Failing) test added in 4f38c5e.

See nodejs/node-v0.x-archive#1711

HTTP/0.9 - fails with a parse error HTTP/1.0 - works HTTP/1.1 - fails with an empty response body See nodejs#1711.

Main fix was in 3abebf which added HTTP/0.9 support to http parser. Changed test because HTTP 1.1 mandates keep-alive when no headers are given. Fixes nodejs#1711

shauket · 2015-11-09T13:18:52Z

kindly guide me how can i parse header response using c++

bnoordhuis added a commit that referenced this issue Nov 17, 2011

test: add 'response body with no headers' http test

4f38c5e

HTTP/0.9 - fails with a parse error HTTP/1.0 - works HTTP/1.1 - fails with an empty response body See #1711.

ry pushed a commit to nodejs/http-parser that referenced this issue Nov 22, 2011

Accept HTTP/0.9 responses

2498961

See nodejs/node-v0.x-archive#1711

felixge pushed a commit to felixge/node that referenced this issue Nov 22, 2011

test: add 'response body with no headers' http test

246805d

HTTP/0.9 - fails with a parse error HTTP/1.0 - works HTTP/1.1 - fails with an empty response body See nodejs#1711.

felixge closed this as completed in 6e1e9e2 Nov 22, 2011

alexkwolfe pushed a commit to alexkwolfe/node that referenced this issue Dec 23, 2011

test: add 'response body with no headers' http test

1b2fd04

HTTP/0.9 - fails with a parse error HTTP/1.0 - works HTTP/1.1 - fails with an empty response body See nodejs#1711.

koichik mentioned this issue Jan 4, 2012

http response not emitting data #2457

Closed

vokal-isaac mentioned this issue Oct 27, 2014

Update README with response file format examples vokal/VOKMockUrlProtocol#6

Merged

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HTTP parser fails if server returns no headers #1711

HTTP parser fails if server returns no headers #1711

davglass commented Sep 15, 2011

ry commented Sep 15, 2011

davglass commented Sep 15, 2011

ry commented Sep 15, 2011

mnot commented Sep 16, 2011

c4milo commented Sep 16, 2011

pstadler commented Oct 3, 2011

dazagrohovaz commented Nov 17, 2011

c4milo commented Nov 17, 2011

bnoordhuis commented Nov 17, 2011

bnoordhuis commented Nov 17, 2011

shauket commented Nov 9, 2015

HTTP parser fails if server returns no headers #1711

HTTP parser fails if server returns no headers #1711

Comments

davglass commented Sep 15, 2011

ry commented Sep 15, 2011

davglass commented Sep 15, 2011

ry commented Sep 15, 2011

mnot commented Sep 16, 2011

c4milo commented Sep 16, 2011

pstadler commented Oct 3, 2011

dazagrohovaz commented Nov 17, 2011

c4milo commented Nov 17, 2011

bnoordhuis commented Nov 17, 2011

bnoordhuis commented Nov 17, 2011

shauket commented Nov 9, 2015