khttpd

The linux kernel module for HTTP static file service.

Description

Loaded in the kernel to provide HTTP static file service, support keep-alive and files list.

List of files:

Prepare

Installing linux kernel headers on Ubuntu:

$ sudo apt-get install linux-headers-$(uname -r)

build

$ make

Usage

First load khttpd.ko kernel model:

$ sudo insmod ./khttpd.ko port=8000 root=/home/ubuntu/khttpd

it is now listening to 0.0.0.0:8000 and can send requests.

Sending http request file:

$ curl http://10.211.55.4:8000/src/http_request.c -voa
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0*   Trying 10.211.55.4:8000...
* Connected to 10.211.55.4 (10.211.55.4) port 8000 (#0)
> GET /src/http_request.c HTTP/1.1
> Host: 10.211.55.4:8000
> User-Agent: curl/7.88.1
> Accept: */*
>
< HTTP/1.1 200 OK
< Server: khttpd/0.0.1
< Connection: close
< Content-Length: 4007
<
{ [2896 bytes data]
100  4007  100  4007    0     0   522k      0 --:--:-- --:--:-- --:--:-- 1956k
* Closing connection 0

File SHA256

$ openssl dgst -sha256 ./a
SHA256(./a)= 2b9470d3437c346ff716bd9109f7541b286b67651e5eeec01b2629b236255b75

$ openssl dgst -sha256 /home/ubuntu/khttpd/src/http_request.c
SHA2-256(/home/ubuntu/khttpd/src/http_request.c)= 2b9470d3437c346ff716bd9109f7541b286b67651e5eeec01b2629b236255b75

Of course, it is possible to list the files in the directory if the folder exists:

# curl http://127.0.0.1:8000/src -v -L
*   Trying 127.0.0.1:8000...
* Connected to 127.0.0.1 (127.0.0.1) port 8000 (#0)
> GET /src HTTP/1.1
> Host: 127.0.0.1:8000
> User-Agent: curl/7.81.0
> Accept: */*
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 302 Found
< Server: khttpd/0.0.1
< Connection: close
< Location: /src/
* Closing connection 0
* Issue another request to this URL: 'http://127.0.0.1:8000/src/'
* Hostname 127.0.0.1 was found in DNS cache
*   Trying 127.0.0.1:8000...
* Connected to 127.0.0.1 (127.0.0.1) port 8000 (#1)
> GET /src/ HTTP/1.1
> Host: 127.0.0.1:8000
> User-Agent: curl/7.81.0
> Accept: */*
>
* Mark bundle as not supporting multiuse
< HTTP/1.1 200 OK
< Server: khttpd/0.0.1
< Connection: close
< Transfer-Encoding: chunked
<
<html><head><title>Directory listing for /src/</title>
... ignore more html body ...

Parameters

The khttpd.ko module provides the following parameters with default values:

# Listening address
listen_addr=0.0.0.0

# Listening port
port=8000

# Pending connections queue size
backlog=1024

# Sets the root directory for requests
root_dir=/var/www/html

Reference

https://github.com/sysprog21/khttpd

https://github.com/h2o/picohttpparser