# Perl Routines to Manipulate CGI input
# [email protected]
# $Id: cgi-lib.pl,v 2.18 1999/02/23 08:16:43 brenner Exp $
#
# Copyright (c) 1993-1999 Steven E. Brenner
# Unpublished work.
# Permission granted to use and modify this library so long as the
# copyright above is maintained, modifications are documented, and
# credit is given for any use of the library.
#
# Thanks are due to many people for reporting bugs and suggestions
# For more information, see:
# http://cgi-lib.stanford.edu/cgi-lib/
$cgi_lib'version = sprintf("%d.%02d", q$Revision: 2.18 $ =~ /(\d+)\.(\d+)/);
# Parameters affecting cgi-lib behavior
# User-configurable parameters affecting file upload.
$cgi_lib'maxdata = 131072; # maximum bytes to accept via POST - 2^17
$cgi_lib'writefiles = 0; # directory to which to write files, or
# 0 if files should not be written
$cgi_lib'filepre = "cgi-lib"; # Prefix of file names, in directory above
# Do not change the following parameters unless you have special reasons
$cgi_lib'bufsize = 8192; # default buffer size when reading multipart
$cgi_lib'maxbound = 100; # maximum boundary length to be encounterd
$cgi_lib'headerout = 0; # indicates whether the header has been printed
# ReadParse
# Reads in GET or POST data, converts it to unescaped text, and puts
# key/value pairs in %in, using "\0" to separate multiple selections
# Returns >0 if there was input, 0 if there was no input
# undef indicates some failure.
# Now that cgi scripts can be put in the normal file space, it is useful
# to combine both the form and the script in one place. If no parameters
# are given (i.e., ReadParse returns FALSE), then a form could be output.
# If a reference to a hash is given, then the data will be stored in that
# hash, but the data from $in and @in will become inaccessable.
# If a variable-glob (e.g., *cgi_input) is the first parameter to ReadParse,
# information is stored there, rather than in $in, @in, and %in.
# Second, third, and fourth parameters fill associative arrays analagous to
# %in with data relevant to file uploads.
# If no method is given, the script will process both command-line arguments
# of the form: name=value and any text that is in $ENV{'QUERY_STRING'}
# This is intended to aid debugging and may be changed in future releases
sub ReadParse {
# Disable warnings as this code deliberately uses local and environment
# variables which are preset to undef (i.e., not explicitly initialized)
local ($perlwarn);
$perlwarn = $^W;
$^W = 0;
local (*in) = shift if @_; # CGI input
local (*incfn, # Client's filename (may not be provided)
*inct, # Client's content-type (may not be provided)
*insfn) = @_; # Server's filename (for spooled files)
local ($len, $type, $meth, $errflag, $cmdflag, $got, $name);
binmode(STDIN); # we need these for DOS-based systems
binmode(STDOUT); # and they shouldn't hurt anything else
binmode(STDERR);
# Get several useful env variables
$type = $ENV{'CONTENT_TYPE'};
$len = $ENV{'CONTENT_LENGTH'};
$meth = $ENV{'REQUEST_METHOD'};
if ($len > $cgi_lib'maxdata) { #'
&CgiDie("cgi-lib.pl: Request to receive too much data: $len bytes\n");
}
if (!defined $meth || $meth eq '' || $meth eq 'GET' ||
$meth eq 'HEAD' ||
$type eq 'application/x-www-form-urlencoded') {
local ($key, $val, $i);
# Read in text
if (!defined $meth || $meth eq '') {
$in = $ENV{'QUERY_STRING'};
$cmdflag = 1; # also use command-line options
} elsif($meth eq 'GET' || $meth eq 'HEAD') {
$in = $ENV{'QUERY_STRING'};
} elsif ($meth eq 'POST') {
if (($got = read(STDIN, $in, $len) != $len))
{$errflag="Short Read: wanted $len, got $got\n";};
} else {
&CgiDie("cgi-lib.pl: Unknown request method: $meth\n");
}
@in = split(/[&;]/,$in);
push(@in, @ARGV) if $cmdflag; # add command-line parameters
foreach $i (0 .. $#in) {
# Convert plus to space
$in[$i] =~ s/\+/ /g;
# Split into key and value.
($key, $val) = split(/=/,$in[$i],2); # splits on the first =.
# Convert %XX from hex numbers to alphanumeric
$key =~ s/%([A-Fa-f0-9]{2})/pack("c",hex($1))/ge;
$val =~ s/%([A-Fa-f0-9]{2})/pack("c",hex($1))/ge;
# Associate key and value
$in{$key} .= "\0" if (defined($in{$key})); # \0 is the multiple separator
$in{$key} .= $val;
}
} elsif ($ENV{'CONTENT_TYPE'} =~ m#^multipart/form-data#) {
# for efficiency, compile multipart code only if needed
$errflag = !(eval <<'END_MULTIPART');
local ($buf, $boundary, $head, @heads, $cd, $ct, $fname, $ctype, $blen);
local ($bpos, $lpos, $left, $amt, $fn, $ser);
local ($bufsize, $maxbound, $writefiles) =
($cgi_lib'bufsize, $cgi_lib'maxbound, $cgi_lib'writefiles);
# The following lines exist solely to eliminate spurious warning messages
$buf = '';
($boundary) = $type =~ /boundary="([^"]+)"/; #"; # find boundary
($boundary) = $type =~ /boundary=(\S+)/ unless $boundary;
&CgiDie ("Boundary not provided: probably a bug in your server")
unless $boundary;
$boundary = "--" . $boundary;
$blen = length ($boundary);
if ($ENV{'REQUEST_METHOD'} ne 'POST') {
&CgiDie("Invalid request method for multipart/form-data: $meth\n");
}
if ($writefiles) {
local($me);
stat ($writefiles);
$writefiles = "/tmp" unless -d _ && -w _;
# ($me) = $0 =~ m#([^/]*)$#;
$writefiles .= "/$cgi_lib'filepre";
}
# read in the data and split into parts:
# put headers in @in and data in %in
# General algorithm:
# There are two dividers: the border and the '\r\n\r\n' between
# header and body. Iterate between searching for these
# Retain a buffer of size(bufsize+maxbound); the latter part is
# to ensure that dividers don't get lost by wrapping between two bufs
# Look for a divider in the current batch. If not found, then
# save all of bufsize, move the maxbound extra buffer to the front of
# the buffer, and read in a new bufsize bytes. If a divider is found,
# save everything up to the divider. Then empty the buffer of everything
# up to the end of the divider. Refill buffer to bufsize+maxbound
# Note slightly odd organization. Code before BODY: really goes with
# code following HEAD:, but is put first to 'pre-fill' buffers. BODY:
# is placed before HEAD: because we first need to discard any 'preface,'
# which would be analagous to a body without a preceeding head.
$left = $len;
PART: # find each part of the multi-part while reading data
while (1) {
die $@ if $errflag;
$amt = ($left > $bufsize+$maxbound-length($buf)
? $bufsize+$maxbound-length($buf): $left);
$errflag = (($got = read(STDIN, $buf, $amt, length($buf))) != $amt);
die "Short Read: wanted $amt, got $got\n" if $errflag;
$left -= $amt;
$in{$name} .= "\0" if defined $in{$name};
$in{$name} .= $fn if $fn;
$name=~/([-\w]+)/; # This allows $insfn{$name} to be untainted
if (defined $1) {
$insfn{$1} .= "\0" if defined $insfn{$1};
$insfn{$1} .= $fn if $fn;
}
BODY:
while (($bpos = index($buf, $boundary)) == -1) {
if ($left == 0 && $buf eq '') {
foreach $value (values %insfn) {
unlink(split("\0",$value));
}
&CgiDie("cgi-lib.pl: reached end of input while seeking boundary " .
"of multipart. Format of CGI input is wrong.\n");
}
die $@ if $errflag;
if ($name) { # if no $name, then it's the prologue -- discard
if ($fn) { print FILE substr($buf, 0, $bufsize); }
else { $in{$name} .= substr($buf, 0, $bufsize); }
}
$buf = substr($buf, $bufsize);
$amt = ($left > $bufsize ? $bufsize : $left); #$maxbound==length($buf);
$errflag = (($got = read(STDIN, $buf, $amt, length($buf))) != $amt);
die "Short Read: wanted $amt, got $got\n" if $errflag;
$left -= $amt;
}
if (defined $name) { # if no $name, then it's the prologue -- discard
if ($fn) { print FILE substr($buf, 0, $bpos-2); }
else { $in {$name} .= substr($buf, 0, $bpos-2); } # kill last \r\n
}
close (FILE);
last PART if substr($buf, $bpos + $blen, 2) eq "--";
substr($buf, 0, $bpos+$blen+2) = '';
$amt = ($left > $bufsize+$maxbound-length($buf)
? $bufsize+$maxbound-length($buf) : $left);
$errflag = (($got = read(STDIN, $buf, $amt, length($buf))) != $amt);
die "Short Read: wanted $amt, got $got\n" if $errflag;
$left -= $amt;
undef $head; undef $fn;
HEAD:
while (($lpos = index($buf, "\r\n\r\n")) == -1) {
if ($left == 0 && $buf eq '') {
foreach $value (values %insfn) {
unlink(split("\0",$value));
}
&CgiDie("cgi-lib: reached end of input while seeking end of " .
"headers. Format of CGI input is wrong.\n$buf");
}
die $@ if $errflag;
$head .= substr($buf, 0, $bufsize);
$buf = substr($buf, $bufsize);
$amt = ($left > $bufsize ? $bufsize : $left); #$maxbound==length($buf);
$errflag = (($got = read(STDIN, $buf, $amt, length($buf))) != $amt);
die "Short Read: wanted $amt, got $got\n" if $errflag;
$left -= $amt;
}
$head .= substr($buf, 0, $lpos+2);
push (@in, $head);
@heads = split("\r\n", $head);
($cd) = grep (/^\s*Content-Disposition:/i, @heads);
($ct) = grep (/^\s*Content-Type:/i, @heads);
($name) = $cd =~ /\bname="([^"]+)"/i; #";
($name) = $cd =~ /\bname=([^\s:;]+)/i unless defined $name;
($fname) = $cd =~ /\bfilename="([^"]*)"/i; #"; # filename can be null-str
($fname) = $cd =~ /\bfilename=([^\s:;]+)/i unless defined $fname;
$incfn{$name} .= (defined $in{$name} ? "\0" : "") .
(defined $fname ? $fname : "");
($ctype) = $ct =~ /^\s*Content-type:\s*"([^"]+)"/i; #";
($ctype) = $ct =~ /^\s*Content-Type:\s*([^\s:;]+)/i unless defined $ctype;
$inct{$name} .= (defined $in{$name} ? "\0" : "") . $ctype;
if ($writefiles && defined $fname) {
$ser++;
$fn = $writefiles . ".$$.$ser";
open (FILE, ">$fn") || &CgiDie("Couldn't open $fn\n");
binmode (FILE); # write files accurately
}
substr($buf, 0, $lpos+4) = '';
undef $fname;
undef $ctype;
}
1;
END_MULTIPART
if ($errflag) {
local ($errmsg, $value);
$errmsg = $@ || $errflag;
foreach $value (values %insfn) {
unlink(split("\0",$value));
}
&CgiDie($errmsg);
} else {
# everything's ok.
}
} else {
&CgiDie("cgi-lib.pl: Unknown Content-type: $ENV{'CONTENT_TYPE'}\n");
}
# no-ops to avoid warnings
$insfn = $insfn;
$incfn = $incfn;
$inct = $inct;
$^W = $perlwarn;
return ($errflag ? undef : scalar(@in));
}
# PrintHeader
# Returns the magic line which tells WWW that we're an HTML document
sub PrintHeader {
return "Content-type: text/html\n\n";
}
# HtmlTop
# Returns the of a document and the beginning of the body
# with the title and a body header as specified by the parameter
sub HtmlTop
{
local ($title) = @_;
return <
$title
$title
END_OF_TEXT
}
# HtmlBot
# Returns the , codes for the bottom of every HTML page
sub HtmlBot
{
return "
\n