Serveur web minimal utilisant netcat

Question

J'essaie de mettre en place un serveur web minimal en utilisant netcat (nc). Lorsque le navigateur appelle localhost:1500, par exemple, il doit afficher le résultat d'une fonction ( date dans l'exemple ci-dessous, mais éventuellement ce sera un programme python ou c qui produira des données). Mon petit serveur web netcat doit être une boucle while true en bash, peut-être aussi simple que ceci :

while true ; do  echo -e "HTTP/1.1 200 OK\n\n $(date)" | nc -l -p 1500  ; done

Lorsque j'essaie ceci, le navigateur affiche les données actuellement disponibles au moment où nc démarre. Mais je veux que le navigateur affiche les données au moment où le navigateur les demande. Comment puis-je y parvenir ?

Answer 1

J'avais le même besoin/problème mais rien ici n'a fonctionné pour moi (ou je n'ai pas tout compris), donc voici ma solution.

Je poste mon minimal_http_server.sh (qui fonctionne avec mon /bin/bash (4.3.11) mais pas /bin/sh à cause de la redirection) :

rm -f out
mkfifo out
trap "rm -f out" EXIT
while true
do
  cat out | nc -l 1500 > >( # parse the netcat output, to build the answer redirected to the pipe "out".
    export REQUEST=
    while read -r line
    do
      line=$(echo "$line" | tr -d '\r\n')

      if echo "$line" | grep -qE '^GET /' # if line starts with "GET /"
      then
        REQUEST=$(echo "$line" | cut -d ' ' -f2) # extract the request
      elif [ -z "$line" ] # empty line / end of request
      then
        # call a script here
        # Note: REQUEST is exported, so the script can parse it (to answer 200/403/404 status code + content)
        ./a_script.sh > out
      fi
    done
  )
done

Et mon a_script.sh (avec votre besoin) :

#!/bin/bash

echo -e "HTTP/1.1 200 OK\r"
echo "Content-type: text/html"
echo

date

Answer 2

mkfifo pipe;
while true ; 
do 
   #use read line from pipe to make it blocks before request comes in,
   #this is the key.
   { read line<pipe;echo -e "HTTP/1.1 200 OK\r\n";echo $(date);
   }  | nc -l -q 0 -p 8080 > pipe;  

done

Answer 3

Voici une beauté de un petit serveur web en bash Je l'ai trouvé en ligne, j'en ai fait une copie et je l'ai un peu amélioré. socat o netcat Je l'ai testé avec socat -- Il est autonome, contenu dans un seul script et génère son propre fichier de configuration et son propre favicon.

Par défaut, il démarre en tant que navigateur de fichiers Web, mais il est facilement configurable par le fichier de configuration pour toute logique. Pour les fichiers, il diffuse des images, de la musique (mp3) et des vidéos (mp4, avi, etc.). J'ai testé la diffusion de divers types de fichiers sur des appareils Linux, Windows et Android, y compris une smartwatch !

Je pense qu'il diffuse mieux que VLC en fait. Je l'ai trouvé utile pour transférer des fichiers à des clients distants qui n'ont pas d'autre accès qu'un navigateur web, par exemple une smartwatch Android, sans avoir à se soucier de la connexion physique à un port USB.

Si vous voulez l'essayer, il suffit de le copier et de le coller dans un fichier nommé bashttpd, puis de le lancer sur l'hôte avec $> bashttpd -s

Ensuite, vous pouvez aller sur n'importe quel autre ordinateur (en supposant que le pare-feu ne bloque pas les connexions tcp entrantes sur le port 8080 -- le port par défaut, vous pouvez changer le port à ce que vous voulez en utilisant les variables globales en haut du script). http://bashttpd_server_ip:8080

#!/usr/bin/env bash

#############################################################################
###########################################################################
###                          bashttpd v 1.12
###
### Original author: Avleen Vig,       2012
### Reworked by:     Josh Cartwright,  2012
### Modified by:     A.M.Danischewski, 2015 
### Issues: If you find any issues leave me a comment at 
### http://scriptsandoneliners.blogspot.com/2015/04/bashttpd-self-contained-bash-webserver.html 
### 
### This is a simple Bash based webserver. By default it will browse files and allows for 
### retrieving binary files. 
### 
### It has been tested successfully to view and stream files including images, mp3s, 
### mp4s and downloading files of any type including binary and compressed files via  
### any web browser. 
### 
### Successfully tested on various browsers on Windows, Linux and Android devices (including the 
### Android Smartwatch ZGPAX S8).  
### 
### It handles favicon requests by hardcoded favicon image -- by default a marathon 
### runner; change it to whatever you want! By base64 encoding your favorit favicon 
### and changing the global variable below this header.  
### 
### Make sure if you have a firewall it allows connections to the port you plan to 
### listen on (8080 by default).  
### 
### By default this program will allow for the browsing of files from the 
### computer where it is run.  
###  
### Make sure you are allowed connections to the port you plan to listen on 
### (8080 by default). Then just drop it on a host machine (that has bash) 
### and start it up like this:
###      
### $192.168.1.101> bashttpd -s
###      
### On the remote machine you should be able to browse and download files from the host 
### server via any web browser by visiting:
###      
### http://192.168.1.101:8080 
###  
#### This program requires (to work to full capacity) by default: 
### socat or netcat (w/ '-e' option - on Ubuntu netcat-traditional)
### tree - useful for pretty directory listings 
### If you are using socat, you can type: bashttpd -s  
### 
### to start listening on the LISTEN_PORT (default is 8080), you can change 
### the port below.  
###  E.g.    nc -lp 8080 -e ./bashttpd ## <-- If your nc has the -e option.   
###  E.g.    nc.traditional -lp 8080 -e ./bashttpd 
###  E.g.    bashttpd -s  -or- socat TCP4-LISTEN:8080,fork EXEC:bashttpd
### 
### Copyright (C) 2012, Avleen Vig <avleen@gmail.com>
### 
### Permission is hereby granted, free of charge, to any person obtaining a copy of
### this software and associated documentation files (the "Software"), to deal in
### the Software without restriction, including without limitation the rights to
### use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
### the Software, and to permit persons to whom the Software is furnished to do so,
### subject to the following conditions:
### 
### The above copyright notice and this permission notice shall be included in all
### copies or substantial portions of the Software.
### 
### THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
### IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
### FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
### COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
### IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
### CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
### 
###########################################################################
#############################################################################

  ### CHANGE THIS TO WHERE YOU WANT THE CONFIGURATION FILE TO RESIDE 
declare -r BASHTTPD_CONF="/tmp/bashttpd.conf"

  ### CHANGE THIS IF YOU WOULD LIKE TO LISTEN ON A DIFFERENT PORT 
declare -i LISTEN_PORT=8080  

 ## If you are on AIX, IRIX, Solaris, or a hardened system redirecting 
 ## to /dev/random will probably break, you can change it to /dev/null.  
declare -a DUMP_DEV="/dev/random" 

 ## Just base64 encode your favorite favicon and change this to whatever you want.    
declare -r FAVICON="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" 

declare -i DEBUG=1 
declare -i VERBOSE=0
declare -a REQUEST_HEADERS
declare    REQUEST_URI="" 
declare -a HTTP_RESPONSE=(
   [200]="OK"
   [400]="Bad Request"
   [403]="Forbidden"
   [404]="Not Found"
   [405]="Method Not Allowed"
   [500]="Internal Server Error")
declare DATE=$(date +"%a, %d %b %Y %H:%M:%S %Z")
declare -a RESPONSE_HEADERS=(
      "Date: $DATE"
   "Expires: $DATE"
    "Server: Slash Bin Slash Bash"
)

function warn() { ((${VERBOSE})) && echo "WARNING: $@" >&2; }

function chk_conf_file() { 
[ -r "${BASHTTPD_CONF}" ] || {
   cat >"${BASHTTPD_CONF}" <<'EOF'
#
# bashttpd.conf - configuration for bashttpd
#
# The behavior of bashttpd is dictated by the evaluation
# of rules specified in this configuration file.  Each rule
# is evaluated until one is matched.  If no rule is matched,
# bashttpd will serve a 500 Internal Server Error.
#
# The format of the rules are:
#    on_uri_match REGEX command [args]
#    unconditionally command [args]
#
# on_uri_match:
#   On an incoming request, the URI is checked against the specified
#   (bash-supported extended) regular expression, and if encounters a match the
#   specified command is executed with the specified arguments.
#
#   For additional flexibility, on_uri_match will also pass the results of the
#   regular expression match, ${BASH_REMATCH[@]} as additional arguments to the
#   command.
#
# unconditionally:
#   Always serve via the specified command.  Useful for catchall rules.
#
# The following commands are available for use:
#
#   serve_file FILE
#     Statically serves a single file.
#
#   serve_dir_with_tree DIRECTORY
#     Statically serves the specified directory using 'tree'.  It must be
#     installed and in the PATH.
#
#   serve_dir_with_ls DIRECTORY
#     Statically serves the specified directory using 'ls -al'.
#
#   serve_dir  DIRECTORY
#     Statically serves a single directory listing.  Will use 'tree' if it is
#     installed and in the PATH, otherwise, 'ls -al'
#
#   serve_dir_or_file_from DIRECTORY
#     Serves either a directory listing (using serve_dir) or a file (using
#     serve_file).  Constructs local path by appending the specified root
#     directory, and the URI portion of the client request.
#
#   serve_static_string STRING
#     Serves the specified static string with Content-Type text/plain.
#
# Examples of rules:
#
# on_uri_match '^/issue$' serve_file "/etc/issue"
#
#   When a client's requested URI matches the string '/issue', serve them the
#   contents of /etc/issue
#
# on_uri_match 'root' serve_dir /
#
#   When a client's requested URI has the word 'root' in it, serve up
#   a directory listing of /
#
# DOCROOT=/var/www/html
# on_uri_match '/(.*)' serve_dir_or_file_from "$DOCROOT"
#   When any URI request is made, attempt to serve a directory listing
#   or file content based on the request URI, by mapping URI's to local
#   paths relative to the specified "$DOCROOT"
#
#unconditionally serve_static_string 'Hello, world!  You can configure bashttpd by modifying bashttpd.conf.'
DOCROOT=/
on_uri_match '/(.*)' serve_dir_or_file_from 
# More about commands:
#
# It is possible to somewhat easily write your own commands.  An example
# may help.  The following example will serve "Hello, $x!" whenever
# a client sends a request with the URI /say_hello_to/$x:
#
# serve_hello() {
#    add_response_header "Content-Type" "text/plain"
#    send_response_ok_exit <<< "Hello, $2!"
# }
# on_uri_match '^/say_hello_to/(.*)$' serve_hello
#
# Like mentioned before, the contents of ${BASH_REMATCH[@]} are passed
# to your command, so its possible to use regular expression groups
# to pull out info.
#
# With this example, when the requested URI is /say_hello_to/Josh, serve_hello
# is invoked with the arguments '/say_hello_to/Josh' 'Josh',
# (${BASH_REMATCH[0]} is always the full match)
EOF
   warn "Created bashttpd.conf using defaults.  Please review and configure bashttpd.conf before running bashttpd again."
#  exit 1
} 
}

function recv() { ((${VERBOSE})) && echo "< $@" >&2; }

function send() { ((${VERBOSE})) && echo "> $@" >&2; echo "$*"; }

function add_response_header() { RESPONSE_HEADERS+=("$1: $2"); }

function send_response_binary() {
  local code="$1"
  local file="${2}" 
  local transfer_stats="" 
  local tmp_stat_file="/tmp/_send_response_$$_"
  send "HTTP/1.0 $1 ${HTTP_RESPONSE[$1]}"
  for i in "${RESPONSE_HEADERS[@]}"; do
     send "$i"
  done
  send
 if ((${VERBOSE})); then 
   ## Use dd since it handles null bytes
  dd 2>"${tmp_stat_file}" < "${file}" 
  transfer_stats=$(<"${tmp_stat_file}") 
  echo -en ">> Transferred: ${file}\n>> $(awk '/copied/{print}' <<< "${transfer_stats}")\n" >&2  
  rm "${tmp_stat_file}"
 else 
   ## Use dd since it handles null bytes
  dd 2>"${DUMP_DEV}" < "${file}"   
 fi 
}   

function send_response() {
  local code="$1"
  send "HTTP/1.0 $1 ${HTTP_RESPONSE[$1]}"
  for i in "${RESPONSE_HEADERS[@]}"; do
     send "$i"
  done
  send
  while IFS= read -r line; do
     send "${line}"
  done
}

function send_response_ok_exit() { send_response 200; exit 0; }

function send_response_ok_exit_binary() { send_response_binary 200  "${1}"; exit 0; }

function fail_with() { send_response "$1" <<< "$1 ${HTTP_RESPONSE[$1]}"; exit 1; }

function serve_file() {
  local file="$1"
  local CONTENT_TYPE=""
  case "${file}" in
    *\.css)
      CONTENT_TYPE="text/css"
      ;;
    *\.js)
      CONTENT_TYPE="text/javascript"
      ;;
    *)
      CONTENT_TYPE=$(file -b --mime-type "${file}")
      ;;
  esac
  add_response_header "Content-Type"  "${CONTENT_TYPE}"
  CONTENT_LENGTH=$(stat -c'%s' "${file}") 
  add_response_header "Content-Length" "${CONTENT_LENGTH}"
    ## Use binary safe transfer method since text doesn't break. 
  send_response_ok_exit_binary "${file}"
}

function serve_dir_with_tree() {
  local dir="$1" tree_vers tree_opts basehref x
    ## HTML 5 compatible way to avoid tree html from generating favicon
    ## requests in certain browsers, such as browsers in android smartwatches. =) 
  local no_favicon=" <link href=\"data:image/x-icon;base64,${FAVICON}\" rel=\"icon\" type=\"image/x-icon\" />"  
  local tree_page="" 
  local base_server_path="/${2%/}"
  [ "$base_server_path" = "/" ] && base_server_path=".." 
  local tree_opts="--du -h -a --dirsfirst" 
  add_response_header "Content-Type" "text/html"
   # The --du option was added in 1.6.0.   "/${2%/*}"
  read _ tree_vers x < <(tree --version)
  tree_page=$(tree -H "$base_server_path" -L 1 "${tree_opts}" -D "${dir}")
  tree_page=$(sed "5 i ${no_favicon}" <<< "${tree_page}")  
  [[ "${tree_vers}" == v1.6* ]] 
  send_response_ok_exit <<< "${tree_page}"  
}

function serve_dir_with_ls() {
  local dir="$1"
  add_response_header "Content-Type" "text/plain"
  send_response_ok_exit < \
     <(ls -la "${dir}")
}

function serve_dir() {
  local dir="$1"
   # If `tree` is installed, use that for pretty output.
  which tree &>"${DUMP_DEV}" && \
     serve_dir_with_tree "$@"
  serve_dir_with_ls "$@"
  fail_with 500
}

function urldecode() { [ "${1%/}" = "" ] && echo "/" ||  echo -e "$(sed 's/%\([[:xdigit:]]\{2\}\)/\\\x\1/g' <<< "${1%/}")"; } 

function serve_dir_or_file_from() {
  local URL_PATH="${1}/${3}"
  shift
  URL_PATH=$(urldecode "${URL_PATH}") 
  [[ $URL_PATH == *..* ]] && fail_with 400
   # Serve index file if exists in requested directory
  [[ -d "${URL_PATH}" && -f "${URL_PATH}/index.html" && -r "${URL_PATH}/index.html" ]] && \
     URL_PATH="${URL_PATH}/index.html"
  if [[ -f "${URL_PATH}" ]]; then
     [[ -r "${URL_PATH}" ]] && \
        serve_file "${URL_PATH}" "$@" || fail_with 403
  elif [[ -d "${URL_PATH}" ]]; then
     [[ -x "${URL_PATH}" ]] && \
        serve_dir  "${URL_PATH}" "$@" || fail_with 403
  fi
  fail_with 404
}

function serve_static_string() {
  add_response_header "Content-Type" "text/plain"
  send_response_ok_exit <<< "$1"
}

function on_uri_match() {
  local regex="$1"
  shift
  [[ "${REQUEST_URI}" =~ $regex ]] && \
     "$@" "${BASH_REMATCH[@]}"
}

function unconditionally() { "$@" "$REQUEST_URI"; }

function main() { 
  local recv="" 
  local line="" 
  local REQUEST_METHOD=""
  local REQUEST_HTTP_VERSION="" 
  chk_conf_file
  [[ ${UID} = 0 ]] && warn "It is not recommended to run bashttpd as root."
   # Request-Line HTTP RFC 2616 $5.1
  read -r line || fail_with 400
  line=${line%%$'\r'}
  recv "${line}"
  read -r REQUEST_METHOD REQUEST_URI REQUEST_HTTP_VERSION <<< "${line}"
  [ -n "${REQUEST_METHOD}" ] && [ -n "${REQUEST_URI}" ] && \
   [ -n "${REQUEST_HTTP_VERSION}" ] || fail_with 400
   # Only GET is supported at this time
  [ "${REQUEST_METHOD}" = "GET" ] || fail_with 405
  while IFS= read -r line; do
    line=${line%%$'\r'}
    recv "${line}"
      # If we've reached the end of the headers, break.
    [ -z "${line}" ] && break
    REQUEST_HEADERS+=("${line}")
  done
} 

if [[ ! -z "{$1}" ]] && [ "${1}" = "-s" ]; then 
 socat TCP4-LISTEN:${LISTEN_PORT},fork EXEC:"${0}" 
else 
 main 
 source "${BASHTTPD_CONF}" 
 fail_with 500
fi

Answer 4

LOL, un hack super nul, mais au moins curl et firefox l'accepte :

while true ; do (dd if=/dev/zero count=10000;echo -e "HTTP/1.1\n\n $(date)") | nc -l  1500  ; done

Vous feriez mieux de le remplacer rapidement par quelque chose de correct !

Ah oui, mon nc n'étaient pas exactement les mêmes que les vôtres, il n'a pas aimé les -p option.

Answer 5

Si vous utilisez Apline Linux, le netcat de BusyBox est légèrement différent :

while true; do nc -l -p 8080 -e sh -c 'echo -e "HTTP/1.1 200 OK\n\n$(date)"'; done

Et une autre façon d'utiliser printf :

while true; do nc -l -p 8080 -e sh -c "printf 'HTTP/1.1 200 OK\n\n%s' \"$(date)\""; done