State Content-Length in error responses to allow connection reuse

[cgilite] / cgilite.sh

diff --git a/cgilite.sh b/cgilite.sh
index e009a2fed49748e4a9fd9905861643818f766c0c..46866266ea6f3250dd86106a00537a721da0a37f 100755 (executable)
--- a/cgilite.sh
+++ b/cgilite.sh
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-# Copyright 2017 Paul Hänsch
+# Copyright 2017 - 2018 Paul Hänsch
 #
 # This is CGIlite.
 # A collection of posix shell functions for writing CGI scripts.
@@ -22,10 +22,81 @@
 # set -o posix # ksh, not portable
 setopt -o OCTAL_ZEROES 2>&-
 
+BR="$(printf '\n')"
+CR="$(printf '\r')"
+cgilite_timeout=2
+
+HEADER(){
+  # Read value of header line. Use this instead of
+  # referencing HTTP_* environment variables.
+  if [ -n "${cgilite_headers+x}" ]; then
+    printf %s "$cgilite_headers" \
+    | sed -rn 's;^'"${1}"': ([^\r]+)\r?$;\1;i; tX; d; :X;p;q;'
+  else
+    eval "printf %s \"\$HTTP_$(printf %s "${1}" |tr a-z A-Z |tr -c A-Z _)\""
+  fi
+}
+
+HEX_DECODE(){
+  printf "$(printf %s "$1" \
+  | sed -r '
+    s;\\;\\\\;g; :x; s;%([^0-9A-F]);\\045\1;g; tx;
+    # Hexadecimal { %00 - %FF } will be transformed to octal { \000 - \377 } for posix printf
+    s;%[0123].;&\\0;g; s;%[4567].;&\\1;g; s;%[89AB].;&\\2;g; s;%[CDEF].;&\\3;g;
+    s;%[048C][0-7]\\.;&0;g; s;%[048C][89A-F]\\.;&1;g; s;%[159D][0-7]\\.;&2;g; s;%[159D][89A-F]\\.;&3;g;
+    s;%[26AE][0-7]\\.;&4;g; s;%[26AE][89A-F]\\.;&5;g; s;%[37BF][0-7]\\.;&6;g; s;%[37BF][89A-F]\\.;&7;g;
+    s;%.[08](\\..);\10;g; s;%.[19](\\..);\11;g; s;%.[2A](\\..);\12;g; s;%.[3B](\\..);\13;g;
+    s;%.[4C](\\..);\14;g; s;%.[5D](\\..);\15;g; s;%.[6E](\\..);\16;g; s;%.[7F](\\..);\17;g;
+  ')"
+}
+
+if [ -z "$REQUEST_METHOD" -a -z "$SERVER_PROTOCOL" ]; then
+  # no webserver variables means we are running via inetd / ncat
+  # so use builtin web server
+
+  # Use env from inetd as webserver variables
+  REMOTE_ADDR="${TCPREMOTEIP}"
+  SERVER_NAME="${TCPLOCALIP}"
+  SERVER_PORT="${TCPLOCALPORT}"
+
+  # Wait 2 seconds for request or kill connection through watchdog.
+  # Once Request is received the watchdog will be suspended (killed).
+  # At the end of the loop the watchdog will be restarted to enable
+  # timeout for the subsequent request.
+
+  (sleep $cgilite_timeout && kill $$) & cgilite_watchdog=$!
+  while read REQUEST_METHOD REQUEST_URI SERVER_PROTOCOL; do
+    kill $cgilite_watchdog
+    PATH_INFO="$(HEX_DECODE "${REQUEST_URI%\?*}")"
+    QUERY_STRING="${REQUEST_URI#*\?}"
+    cgilite_headers="$(sed -u '/^\r\?$/q')"
+
+    HTTP_CONTENT_LENGTH="$(HEADER Content-Length |grep -xE '[0-9]+')"
+
+    export REMOTE_ADDR SERVER_NAME SERVER_PORT REQUEST_METHOD REQUEST_URI SERVER_PROTOCOL \
+           PATH_INFO QUERY_STRING HTTP_CONTENT_LENGTH
+
+    # Try to serve multiple requests, provided that script serves a
+    # Content-Length header.
+    # Without Content-Length header, connection will terminate after
+    # script.
+
+    . "$0" |sed '1{s;^Status: ;HTTP/1.1 ;; t; s;^;HTTP/1.1 200 OK\r\n;;}' \
+    | while read -r l; do case $l in
+      Content-Length:*) printf '%s\n' "$l"; cat;;
+      $CR) printf 'Connection: close\r\n\r\n'; cat; exit 1;;
+      *) printf '%s\n' "$l";;
+    esac; done || exit 0;
+    (sleep $cgilite_timeout && kill $$) & cgilite_watchdog=$!
+  done
+fi
+
 if [ "$REQUEST_METHOD" = POST -a "${HTTP_CONTENT_LENGTH:=${CONTENT_LENGTH:=0}}" -gt 0 ]; then
   cgilite_post="$(head -c "$HTTP_CONTENT_LENGTH")"
 fi
 
+[ -n "${DEBUG+x}" ] && env
+
 cgilite_count(){
   case $1 in
     GET)  printf %s "&${QUERY_STRING}";;
@@ -37,21 +108,14 @@ cgilite_count(){
 }
 
 cgilite_value(){
-  printf "$(
+  HEX_DECODE "$(
     case $1 in
       GET)  printf %s "&${QUERY_STRING}";;
       POST) printf %s "&${cgilite_post}";;
       REF)  printf %s "&${HTTP_REFERER#*\?}";;
     esac \
     | grep -Eo '&'"$2"'=[^&]*' \
-    | sed -rn "${3:-1}"'{s;^[^=]+=;;; s;\+; ;g; s;\\;\\\\;g;
-      # Hexadecimal { %00 - %FF } will be transformed to octal { \000 - \377 } for posix printf
-      s;%[0123].;&\\0;g; s;%[4567].;&\\1;g; s;%[89AB].;&\\2;g; s;%[CDEF].;&\\3;g;
-      s;%[048C][0-7]\\.;&0;g; s;%[048C][89A-F]\\.;&1;g; s;%[159D][0-7]\\.;&2;g; s;%[159D][89A-F]\\.;&3;g;
-      s;%[26AE][0-7]\\.;&4;g; s;%[26AE][89A-F]\\.;&5;g; s;%[37BF][0-7]\\.;&6;g; s;%[37BF][89A-F]\\.;&7;g;
-      s;%.[08](\\..);\10;g; s;%.[19](\\..);\11;g; s;%.[2A](\\..);\12;g; s;%.[3B](\\..);\13;g;
-      s;%.[4C](\\..);\14;g; s;%.[5D](\\..);\15;g; s;%.[6E](\\..);\16;g; s;%.[7F](\\..);\17;g;
-      p}'
+    | sed -rn "${3:-1}"'{s;^[^=]+=;;; s;\+; ;g; p;}'
   )"
 }
 
@@ -65,17 +129,10 @@ REF(){ cgilite_value REF $@; }
 REF_COUNT(){ cgilite_count REF $1; }
 
 COOKIE(){
-  printf "$(
-    printf %s " ${HTTP_COOKIE}" \
-    | grep -Eo '[; ]'"$1"'=[^;]*' \
-    | sed -rn "${2:-1}"'{s;^[^=]+=;;; s;\+; ;g; s;\\;\\\\;g;
-      # Hexadecimal { %00 - %FF } will be transformed to octal { \000 - \377 } for posix printf
-      s;%[0123].;&\\0;g; s;%[4567].;&\\1;g; s;%[89AB].;&\\2;g; s;%[CDEF].;&\\3;g;
-      s;%[048C][0-7]\\.;&0;g; s;%[048C][89A-F]\\.;&1;g; s;%[159D][0-7]\\.;&2;g; s;%[159D][89A-F]\\.;&3;g;
-      s;%[26AE][0-7]\\.;&4;g; s;%[26AE][89A-F]\\.;&5;g; s;%[37BF][0-7]\\.;&6;g; s;%[37BF][89A-F]\\.;&7;g;
-      s;%.[08](\\..);\10;g; s;%.[19](\\..);\11;g; s;%.[2A](\\..);\12;g; s;%.[3B](\\..);\13;g;
-      s;%.[4C](\\..);\14;g; s;%.[5D](\\..);\15;g; s;%.[6E](\\..);\16;g; s;%.[7F](\\..);\17;g;
-      p}'
+  HEX_DECODE "$(
+    HEADER Cookie \
+    | grep -oE '(^|; ?)'"$1"'=[^;]*' \
+    | sed -rn "${2:-1}"'{s;^[^=]+=;;; s;\+; ;g; p;}'
   )"
 }
 
@@ -129,3 +186,4 @@ REDIRECT(){
   printf 'Status: 303 See Other\r\nLocation: %s\r\n\r\n' "$*"
   exit 0
 }
+