code.delx.au - monosys/blob - bashttpd

   1 #!/bin/bash
   2
   3 ##########################################################################
   4 # Bash HTTP Server                                                       #
   5 #                                                                        #
   6 # This is just a bit of fun. Please don't trust it for anything serious! #
   7 ##########################################################################
   8
   9 # static configuration
  10 PORT="${PORT:-8080}"
  11 SERVER_ROOT="${SERVER_ROOT:-$PWD}"
  12
  13 # per-request globals
  14 STATE_FUNC=""
  15 REQUEST_LINE=""
  16 REQUEST_FILE=""
  17
  18
  19 function main {
  20     set -e
  21
  22     cd "$SERVER_ROOT"
  23     print_log "Server running on port $PORT in $SERVER_ROOT"
  24
  25     while true; do
  26         handle_connection
  27     done
  28 }
  29
  30 function print_log {
  31     echo "$(date -Iseconds) $@"
  32 }
  33
  34 function handle_connection {
  35     start_netcat
  36
  37     STATE_FUNC="handle_read_request_status_line"
  38     while [ -n "$STATE_FUNC" ]; do
  39         $STATE_FUNC || break
  40     done <&"${COPROC[0]}"
  41
  42     close_request
  43 }
  44
  45 function start_netcat {
  46     coproc nc -l "$PORT"
  47 }
  48
  49 function close_request {
  50     STATE_FUNC=""
  51     kill "$COPROC_PID" &> /dev/null || true
  52     wait "$COPROC_PID" &> /dev/null || true
  53 }
  54
  55 function handle_read_request_status_line {
  56     read_request_line
  57     print_log "$REQUEST_LINE"
  58
  59     read method path ignored < <(echo "$REQUEST_LINE")
  60     REQUEST_FILE=".$path"
  61
  62     check_valid_method || return 0
  63     check_path_is_under_server_root || return 0
  64     find_index_in_request_file
  65     check_request_file_exists || return 0
  66
  67     STATE_FUNC="handle_read_request_to_end"
  68 }
  69
  70 function check_valid_method {
  71     if [ "$method" != "GET" ]; then
  72         STATE_FUNC="write_error_response_405"
  73         return 1
  74     fi
  75 }
  76
  77 function check_path_is_under_server_root {
  78     abspath="$(cd "$(dirname "$REQUEST_FILE")" && pwd)"
  79     if ! echo "$abspath" | grep -q "^$PWD"; then
  80         STATE_FUNC="write_error_response_400"
  81         return 1
  82     fi
  83 }
  84
  85 function find_index_in_request_file {
  86     if [ ! -d "$REQUEST_FILE" ]; then
  87         return 0
  88     fi
  89
  90     for filename in index.html index.txt; do
  91         if [ -f "${REQUEST_FILE}/${filename}" ]; then
  92             REQUEST_FILE="${REQUEST_FILE}/${filename}"
  93             return 0
  94         fi
  95     done
  96 }
  97
  98 function check_request_file_exists {
  99     if [ ! -f "$REQUEST_FILE" ]; then
 100         STATE_FUNC="write_error_response_404"
 101         return 1
 102     fi
 103 }
 104
 105 function handle_read_request_to_end {
 106     read_request_line
 107
 108     if [ -z "$REQUEST_LINE" ]; then
 109         STATE_FUNC="write_response"
 110     fi
 111 }
 112
 113 function read_request_line {
 114     read REQUEST_LINE
 115     REQUEST_LINE="$(echo "$REQUEST_LINE" | tr -d '
')"
 116 }
 117
 118 function write_response {
 119     STATE_FUNC=""
 120     cat <<EOT >&"${COPROC[1]}"
 121 HTTP/1.0 200 OK
 122 Server: bashttpd
 123 Content-Type: $(file -bi "$REQUEST_FILE")
 124 Connection: close
 125
 126 $(cat "$REQUEST_FILE")
 127 EOT
 128 }
 129
 130 function write_error_response {
 131     STATE_FUNC=""
 132     local code="$1"
 133     local message="$2"
 134     cat <<EOT >&"${COPROC[1]}"
 135 HTTP/1.0 $code $message
 136
 137 <!DOCTYPE html>
 138 <html>
 139 <head>
 140 <title>$code $message</title>
 141 </head>
 142 <body>
 143 <h1>$code $message</h1>
 144 </body>
 145 </html>
 146 EOT
 147 }
 148
 149 function write_error_response_400 {
 150     write_error_response 400 "Bad Request"
 151 }
 152
 153 function write_error_response_404 {
 154     write_error_response 404 "File Not Found"
 155 }
 156
 157 function write_error_response_405 {
 158     write_error_response 405 "Unsupported method"
 159 }
 160
 161 function check_dependencies {
 162     check_bash
 163     check_netcat
 164 }
 165
 166 function check_bash {
 167     if [ "${BASH_VERSINFO[0]}" -lt 4 ]; then
 168         echo "ERROR! Requires Bash 4+ for coproc support"
 169         exit 1
 170     fi
 171 }
 172
 173 function check_netcat {
 174     if ! nc -h 2>&1 | head -n1 | grep -q '^OpenBSD netcat'; then
 175         echo "ERROR! Requires OpenBSD netcat to be installed"
 176         exit 1
 177     fi
 178 }
 179
 180 check_dependencies
 181 main