Perl ISAPI extra newline in header?

lmz

I have installed Abyss Web Server X1 v2.3.2 and ActivePerl (5.8.8 build 817) with the ISAPI DLL. I am currently trying to run Perl scripts using the ISAPI interface. Here is the relevant bit from abyss.conf (CGI/ISAPI, type is Perl ISAPI):


<interpreter>
	<ext>
		pl
	</ext>
	<interface>
		0
	</interface>
	<file>
		Z:\pkg\Perl\bin\perlis.dll
	</file>
	<checkexists>
		yes
	</checkexists>
	<type>
		2
	</type>
	<updatepaths>
		no
	</updatepaths>
</interpreter>

It seems to insert extra newlines before the script output so the script cannot add the Content-Type header. I tried the following two scripts:
plain.pl:


print "Content-Type: text/plain\r\n\r\nHello!";

test.pl (taking a little from the CGI perldoc)


use CGI qw /:standard/;

print header, start_html('test'), h1('Hello');

This is what I get when trying to access the files from the command line (using the LWP "get" utility)


Z:\>get -ue http://localhost/cgi-bin/plain.pl                                   
GET http://localhost/cgi-bin/plain.pl
Connection: Close
Date: Sat, 28 Oct 2006 14:10:50 GMT
Server: Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2 Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2 
Client-Date: Sat, 28 Oct 2006 14:10:50 GMT
Client-Peer: 127.0.0.1:80
Client-Response-Num: 1

Content-Type: text/plain

Hello!                                                                          

Z:\>get -ue http://localhost/cgi-bin/test.pl
GET http://localhost/cgi-bin/test.pl
Connection: Close
Date: Sat, 28 Oct 2006 14:12:15 GMT
Server: Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2 Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2
Client-Date: Sat, 28 Oct 2006 14:12:15 GMT
Client-Peer: 127.0.0.1:80
Client-Response-Num: 1

Content-Type: text/html; charset=ISO-8859-1

<!DOCTYPE html
        PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
         "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US">
<head>
<title>test</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
</head>
<body>
<h1>Hello</h1>

When I test it in the browser, the "Content-Type" header shows up in the browser display.
I have turned on logging for the ISAPI and this is the contents:


Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/plain.pl	Request #0	New request
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/plain.pl	Request #0	Prefetch-ReadClient() = ""
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/plain.pl	Request #0	ServerSupportFunction(dwHSERequest=HSE_REQ_MAP_URL_TO_PATH, lpvBuffer="")
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/plain.pl	Request #0	GetServerVariable(szVariableName="SCRIPT_NAME")="/cgi-bin/plain.pl"
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/plain.pl	Request #0	GetServerVariable(szVariableName="SERVER_PROTOCOL")="HTTP/1.1"
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/plain.pl	Request #0	WriteClient(Buffer="HTTP/1.1 200 OK
", dwSize=17, dwSync=0)
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/plain.pl	Request #0	WriteClient(Buffer="Date: Sat, 28 Oct 2006 14:10:50 GMT
", dwSize=37, dwSync=0)
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/plain.pl	Request #0	GetServerVariable(szVariableName="SERVER_SOFTWARE")="Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2"
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/plain.pl	Request #0	WriteClient(Buffer="Server: Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2

", dwSize=47, dwSync=0)
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/plain.pl	Request #0	WriteClient(Buffer="Content-Type: text/plain

Hello!", dwSize=34, dwSync=0)
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/plain.pl	Request #0	HttpExtensionProc() = HSE_STATUS_SUCCESS (1) / ecb.dwHttpStatusCode = 200
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	New request
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	Prefetch-ReadClient() = ""
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	ServerSupportFunction(dwHSERequest=HSE_REQ_MAP_URL_TO_PATH, lpvBuffer="")
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	GetServerVariable(szVariableName="SCRIPT_NAME")="/cgi-bin/test.pl"
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	GetServerVariable(szVariableName="SERVER_SOFTWARE")="Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2"
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	GetServerVariable(szVariableName="GATEWAY_INTERFACE")="CGI/1.1"
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	GetServerVariable(szVariableName="SERVER_PROTOCOL")="HTTP/1.1"
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	GetServerVariable(szVariableName="SERVER_PROTOCOL")="HTTP/1.1"
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	WriteClient(Buffer="HTTP/1.1 200 OK
", dwSize=17, dwSync=0)
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	WriteClient(Buffer="Date: Sat, 28 Oct 2006 14:12:15 GMT
", dwSize=37, dwSync=0)
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	GetServerVariable(szVariableName="SERVER_SOFTWARE")="Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2"
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	WriteClient(Buffer="Server: Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2

", dwSize=47, dwSync=0)
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	WriteClient(Buffer="Content-Type: text/html; charset=ISO-8859-1

", dwSize=47, dwSync=0)
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	WriteClient(Buffer="<!DOCTYPE html
	PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
	 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US">
<head>
<title>test</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
</head>
<body>
", dwSize=316, dwSync=0)
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	WriteClient(Buffer="<h1>Hello</h1>", dwSize=14, dwSync=0)
Module: Z:\pkg\Perl\bin\perlis.dll	URI: /cgi-bin/test.pl	Request #1	HttpExtensionProc() = HSE_STATUS_SUCCESS (1) / ecb.dwHttpStatusCode = 200

I think this shows that there are two newlines sent after the "Server:..." header. I have tested these scripts with CGI and they work fine. Is this a problem in my configuration, in Abyss or a in the ActivePerl ISAPI DLL?
Thanks

TRUSTAbyss

It's normal for the extra two lines before the actual HTML output is sent. You
will notice this from all header output scripts.
The real problem is that you're using "\r\n" in the header lines. You need to
use, only the "\n" characters. Example: print "Content-Type: text/html\n\n";
For a full header output:

print "HTTP/1.1 200 OK\n";
print "Content-Length: 13\n";
print "Content-Type: text/html\n\n";

print "Hello, World!";

Note: The last line always requires two "\n" characters.

lmz

TRUSTAbyss wrote

print "HTTP/1.1 200 OK\n";
print "Content-Length: 13\n";
print "Content-Type: text/html\n\n";

print "Hello, World!";

That actually works, but I'd rather not print my HTTP headers myself.
It seems that I need to force the CGI module to do NPH. There is a check to make sure NPH is enabled automatically if it's running under IIS but probably they need to add another check for Abyss... The code below works:


use CGI qw( -nph );
my $cgi = new CGI;
print $cgi->header(), 
$cgi->start_html('hello world'), 
$cgi->h1('hello world'), 
$cgi->end_html();

Thanks for the help :)

aprelium

lmz wrote
It seems that I need to force the CGI module to do NPH. There is a check to make sure NPH is enabled automatically if it's running under IIS but probably they need to add another check for Abyss... The code below works:

Abyss Web Server is smart enough to detect if you're sending an NPH output or not. So there is no need for such a setting as everything is handled automatically.
As you noticed both scripts (NPH and not NPH) worked fine.

lmz

aprelium wrote

lmz wrote
It seems that I need to force the CGI module to do NPH. There is a check to make sure NPH is enabled automatically if it's running under IIS but probably they need to add another check for Abyss... The code below works:

Abyss Web Server is smart enough to detect if you're sending an NPH output or not. So there is no need for such a setting as everything is handled automatically.
As you noticed both scripts (NPH and not NPH) worked fine.

Well, I don't even know what NPH is or how Abyss detects it, but I know that this code:


use CGI qw( -nph );
my $cgi = new CGI;
print $cgi->header(),
$cgi->start_html('hello world'),
$cgi->h1('hello world'),
$cgi->end_html();

works fine, and this code (note the commented out nph param):


use CGI ; # qw( -nph );
my $cgi = new CGI;
print $cgi->header(),
$cgi->start_html('hello world'),
$cgi->h1('hello world'),
$cgi->end_html();

displays a Content-Type header in the response body (with configuration like in my first post).

aprelium

lmz,
NPH means Non-parsed headers. This is when the script sends headers to the server without using the CGI spec and asks the server to not preprocess them and to forward them as they are to the client directly.
In the second script it seems that Perl ISAPI is messing with the NPH output. Could you please set temporarily the Perl interpreter to use perl.exe instead of PerlIS.dll and retest your second script? Is it working fine?

lmz

OK, so I have associated *.pl with Perl ISAPI and *.pcgi with Perl CGI.
this is nph.{pl,pcgi} :


use CGI qw( -nph );
my $cgi = new CGI;
print $cgi->header(),
$cgi->start_html('hello world'),
$cgi->h1('hello world'),
$cgi->end_html();

and this is nonph.{pl,pcgi}


use CGI ; #qw( -nph );
my $cgi = new CGI;
print $cgi->header(),
$cgi->start_html('hello world'),
$cgi->h1('hello world'),
$cgi->end_html();

and the results:


Z:\cgi-bin>GET -ue http://localhost/cgi-bin/nph.pl                             
GET http://localhost/cgi-bin/nph.pl                                            
Connection: Close                                                              
Date: Thu, 02 Nov 2006 09:03:11 GMT                                            
Server: Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2 Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2
Content-Type: text/html; charset=ISO-8859-1                                    
Content-Type: text/html; charset=iso-8859-1                                    
Client-Date: Thu, 02 Nov 2006 09:03:12 GMT                                     
Client-Peer: 127.0.0.1:80                                                      
Client-Response-Num: 1                                                         
Title: hello world                                                             

<!DOCTYPE html                                                                 
        PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"                        
         "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">            
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US">      
<head>                                                                         
<title>hello world</title>                                                     
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />     
</head>                                                                        
<body>                                                                         
<h1>hello world</h1>                                                           
</body>                                                                        
</html>                                                                        
Z:\cgi-bin>GET -ue http://localhost/cgi-bin/nph.pcgi                           
GET http://localhost/cgi-bin/nph.pcgi                                          
Date: Thu, 02 Nov 2006 09:03:15 GMT                                            
Server: Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2                                    
Content-Type: text/html; charset=ISO-8859-1                                    
Content-Type: text/html; charset=iso-8859-1                                    
Client-Date: Thu, 02 Nov 2006 09:03:15 GMT                                     
Client-Peer: 127.0.0.1:80                                                      
Client-Response-Num: 1                                                         
Title: hello world                                                             

<!DOCTYPE html                                                                 
        PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"                        
         "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">            
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US">      
<head>                                                                         
<title>hello world</title>                                                     
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />     
</head>                                                                        
<body>                                                                         
<h1>hello world</h1>                                                           
</body>                                                                        
</html>                                                                        
Z:\cgi-bin>GET -ue http://localhost/cgi-bin/nonph.pl                           
GET http://localhost/cgi-bin/nonph.pl                                          
Connection: Close                                                              
Date: Thu, 02 Nov 2006 09:03:37 GMT                                            
Server: Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2 Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2
Client-Date: Thu, 02 Nov 2006 09:03:38 GMT                                     
Client-Peer: 127.0.0.1:80                                                      
Client-Response-Num: 1                                                         

Content-Type: text/html; charset=ISO-8859-1                                    

<!DOCTYPE html                                                                 
        PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"                        
         "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">            
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US">      
<head>                                                                         
<title>hello world</title>                                                     
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />     
</head>                                                                        
<body>                                                                         
<h1>hello world</h1>                                                           
</body>                                                                        
</html>                                                                        
Z:\cgi-bin>GET -ue http://localhost/cgi-bin/nonph.pcgi                         
GET http://localhost/cgi-bin/nonph.pcgi                                        
Connection: Close                                                              
Date: Thu, 02 Nov 2006 09:03:40 GMT                                            
Server: Abyss/2.3.2-X1-Win32 AbyssLib/2.3.2                                    
Content-Type: text/html; charset=ISO-8859-1                                    
Content-Type: text/html; charset=iso-8859-1                                    
Client-Date: Thu, 02 Nov 2006 09:03:40 GMT                                     
Client-Peer: 127.0.0.1:80                                                      
Client-Response-Num: 1                                                         
Title: hello world                                                             

<!DOCTYPE html                                                                 
        PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"                        
         "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">            
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US" xml:lang="en-US">      
<head>                                                                         
<title>hello world</title>                                                     
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />     
</head>                                                                        
<body>                                                                         
<h1>hello world</h1>                                                           
</body>                                                                        
</html>

In a web browser, all of them display fine except the nonph.pl script which displays a content-type header in the document body.

aprelium

lmz,
Thank you for the detailed information you have provided. We'll check the Perl ISAPI again with your script to determine why it is sending the Content-type header in the body.
FYI, the ActivePerl ISAPI mode has been created to provide several workarounds and to fix the broken behavior of this ISAPI which is not fully conforming to the standard. We did our best to test it with popular Perl scripts but as you have shown with your simple test, there are still situations which are not correctly handled.