CODEWITHSUNDEEP
httprequesthaproxyspacehttp-status-code-400
Kamil
Kamil

Reputation: 36

Why always receive status code 400 when sending HTTP request to HAProxy

I've got an HAProxy work in HTTP mode, and everything went very well.

But when I send a request with space(Yes ASCII 32) in URI, something vvvveeeeeerrrrryyyy strange happed!

I received status code 400: Your browser sent an invalid request.

This is the request, you can use curl to test:

# Do not use browser like Chrome or Firefox, or the request will be encoded
# before is was sent to HAProxy
# haproxy is my testing server here
curl -i -v 'http://haproxy/search?oq=haproxy invalid request'

This is the response:

* About to connect() to haproxy port 80 (#0)
*   Trying xx.xxx.xxx.xxx... connected
* Connected to haproxy (xx.xxx.xxx.xxx) port 80 (#0)
> GET /search?oq=haproxy invalid request HTTP/1.1
> User-Agent: curl/7.19.7 (x86_64-redhat-linux-gnu) libcurl/7.19.7 NSS/3.13.6.0 zlib/1.2.3 libidn/1.18 libssh2/1.4.2
> Host: haproxy
> Accept: */*
> 
* HTTP 1.0, assume close after body
< HTTP/1.0 400 Bad request
HTTP/1.0 400 Bad request
< Cache-Control: no-cache
Cache-Control: no-cache
< Connection: close
Connection: close
< Content-Type: text/html
Content-Type: text/html

< 
<html><body><h1>400 Bad request</h1>
Your browser sent an invalid request.
</body></html>
* Closing connection #0

When I encode space to "+" or "%20", everything goes well.

Request like this:

curl -i 'http://haproxy/search?oq=haproxy+invalid+request'
curl -i 'http://haproxy/search?oq=haproxy%20invalid%20request'

Response:

HTTP/1.1 302 Found
Cache-Control: no-cache
Content-length: 0
Location: http://www.google.com/search?oq=haproxy%20invalid%20request
Connection: close

For some reasons, it is impossible for us to encode every space in our request, so I tried to set a parameter for HAProxy followed solution here:

Configuration Manual

extra-space-in-http-headers-gives-400-error-on-haproxy

But both doesn't work.

This is the advised parameter:

# Enable or disable relaxing of HTTP request parsing
option accept-invalid-http-request

Here is my haproxy.cfg

global
    log 127.0.0.1 local2 info
    chroot /usr/local/haproxy
    pidfile /var/run/haproxy.pid
    nbproc 1
    maxconn 32768
    user root
    group root
    daemon
    stats socket /var/lib/haproxy/stats

defaults
    log global
    mode http
    timeout client 10s
    timeout connect 10s
    timeout server 10s

# This is for HTTP over port 80
frontend http_in
    bind 0.0.0.0:80
    maxconn 4096
    option accept-invalid-http-request
    default_backend google

# This is for backend server
backend google
    mode http
    balance roundrobin
    server google1 127.0.0.1:80 redir http://www.google.com check

This is the HTTP log:

Jun  6 12:07:17 localhost haproxy[32059]: 61.155.184.119:45028 [06/Jun/2019:12:07:17.944] http_in http_in/<NOSRV> -1/-1/-1/-1/0 400 187 - - PR-- 1/1/0/0/0 0/0 "<BADREQ>"
Jun  6 12:07:26 localhost haproxy[32059]: 61.155.184.119:45029 [06/Jun/2019:12:07:26.083] http_in http_in/<NOSRV> -1/-1/-1/-1/0 400 187 - - PR-- 1/1/0/0/0 0/0 "<BADREQ>"

This is the socat errors:

echo "show errors" | socat stdio /var/lib/haproxy/stats

Total events captured on [06/Jun/2019:13:17:41.009] : 6

[06/Jun/2019:12:07:26.083] frontend http_in (#2): invalid request
  backend <NONE> (#-1), server <NONE> (#-1), event #5, src xx.xxx.xxx.xxx:45029
  buffer starts at 0 (including 0 out), 16189 free,
  len 195, wraps at 16384, error at position 23
  stream #10, stream flags 0x00000000, tx flags 0x00000000
  HTTP msg state MSG_RQVER(6), msg flags 0x00000000
  HTTP chunk len 0 bytes, HTTP body len 0 bytes, channel flags 0x00d08002 :

  00000  GET /search?oq=haproxy invalid request HTTP/1.1\r\n
  00049  User-Agent: curl/7.19.7 (x86_64-redhat-linux-gnu) libcurl/7.19.7 NSS/3
  00119+ .13.6.0 zlib/1.2.3 libidn/1.18 libssh2/1.4.2\r\n
  00165  Host: haproxy\r\n
  00180  Accept: */*\r\n
  00193  \r\n

Tested HAProxy version: 

HA-Proxy version 1.9.8 2019/05/13
HA-Proxy version 1.5.18 2016/05/10

HAProxy server environment:

CentOS release 6.8 (Final)
Linux version 2.6.32-696.23.1.el6.x86_64 ([email protected]) (gcc version 4.4.7 20120313 (Red Hat 4.4.7-18) (GCC) ) #1 SMP Tue Mar 13 22:44:18 UTC 2018

Has anyone ever had a similar problem?

Any advice and suggestions will be greatly appreciated.

Thanks.

Upvotes: 1

Views: 7643

Answers (1)

Julian Reschke
Julian Reschke

Reputation: 41997

You can't have a space character in the URI. HAProxy is right to correct it.

Could you elaborate on:

"For some reasons, it is impossible for us to encode every space in our request"

?

Also note that the request line is not an HTTP header field, so you were looking at an irrelevant config option.

Upvotes: 2

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