Header "malformed syntax"

**happyclown** · 03-11-2009

Hey folks.

Here are the details:

Code:

char ServerName[40] = "www.example.com";
char FilePath[40] = "/index.html";
.
.
.
strcpy(storage,"GET ");
strcat(storage, FilePath);
strcat(storage, " HTTP/1.1\ Host: ");
strcat(storage, ServerName);
strcat(storage, " \r\n\r\n");

iResult = recv(ConnectSocket,storage,STORAGE_LEN,0);

And here is the server response:

Code:

HTTP/1.1 400 Bad Request
Date: Wed, 11 Mar 2009 10:38:55 GMT
Server: Apache/2.2.3 (CentOS)
Content-Length: 306
Connection: close
Content-Type: text/html; charset=iso-8859-1

<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>400 Bad Request</title>
</head><body>
<h1>Bad Request</h1>
<p>Your browser sent a request that this server could not understand.<br />
</p>
<hr>
<address>Apache/2.2.3 (CentOS) Server at www.example.com Port 80</address>
</body>
</html>

I am getting this type of message from all servers that I have tried to connect to.

A search on google shows that "HTTP/1.1 400 Bad Request" means the header has a "malformed syntax", but I have not been able to find a working solution.

This code below works for some webpages with small amounts of content(a few hundred characters), but for lots of content(a whole page of text), the server resends parts of the content.

Code:

strcpy(storage, "GET / \r\n");
strcat(storage, "HTTP 1.0 \r\n\r\n");

Can someone please point me in the right direction?

Thanks in advance.

EDIT: If I was to use the above code, for www.example.com, here is the server response:

Code:

<HTML>
<HEAD>
<TITLE>Example Web Page</TITLE>
</HEAD> 
<body>  
<p>You have reached this web page by typing &quot;example.com&quot;,
&quot;example.net&quot;, or &quot;example.org&quot; into your web browser.</p>
<p>These domain names are reserved for use in documentation and are not available 
 for registration. See <a href="http://www.rfc-editor.org/rfc/rfc2606.txt">RFC 
 2606</a>, Section 3.</p>
</BODY>
</HTML>

But the server doesn't provide the time, or date, or bytes returned, or the server OS etc.

**vart** · 03-11-2009

" HTTP/1.1\ Host: "

After HTTP/1.1
you need
\r\n not \

You always can use the Etheral/Wireshark to catch packets sent by the browser and your application and compare them to understand the problem

**happyclown** · 03-11-2009

Hi vart.

I tried

Code:

" HTTP/1.1\r\n Host: "

but the server still sends same the message.

So I tried

Code:

char ServerName[40] = "Host: www.example.com";
strcat(storage, " HTTP/1.1\r\n ");

which results in a getaddrinfo() error.

Are you saying Host should not be on the same line as HTTP/1.1?

EDIT: I'll give wireshark a go.

Thanks!

**happyclown** · 03-11-2009

Well, Wireshark shows for a successful connection to www.example.com:

Code:

GET / HTTP/1.1\r\n

User-Agent: Opera/9.27 (Windows NT 5.1; U; en)\r\n
Host: www.example.com\r\n

Accept: text/html, application/xml;q=0.9, application/xhtml+xml, image/png, image/jpeg, image/gif, image/x-xbitmap, */*;q=0.1\r\n
Accept-Language: en-US,en;q=0.9\r\n
Accept-Charset: iso-8859-1, utf-8, utf-16, *;q=0.1\r\n
Accept-Encoding: deflate, gzip, x-gzip, identity, *;q=0\r\n
Connection: Keep-Alive\r\n
\r\n

So I guess I'll have to hand code all this?!

But if I am only using a console, instead of the opera browser, what do I put in the "User Agent" field?

**vart** · 03-11-2009

chose yourself
http://www.user-agents.org/index.shtml

**happyclown** · 03-11-2009

Thanks Vart, I'll give it a go.

**happyclown** · 03-11-2009

Well, I couldn't find any windows console application user-agents in that list, so I just used Opera as the user-agent.

Code:

strcpy(storage,"GET / HTTP/1.1\r\n");
strcat(storage, "User-Agent: Opera/9.27 (Windows NT 5.1; U; en)");
strcat(storage, "\r\n");
strcat(storage, "Host: www.example.com");
strcat(storage, "\r\n");
strcat(storage, "Accept: text/html, application/xml;q=0.9, application/xhtml+xml, image/png, image/jpeg, image/gif, image/x-xbitmap, */ *;q=0.1");
strcat(storage, "\r\n");
strcat(storage, "Accept-Language: en-US,en;q=0.9\r\nAccept-Charset: iso-8859-1, utf-8, utf-16, *;q=0.1");
strcat(storage, "\r\n");
strcat(storage, "Accept-Encoding: deflate, gzip, x-gzip, identity, *;q=0");
strcat(storage, "\r\n");
strcat(storage, "Connection: Keep-Alive");
strcat(storage, "\r\n\r\n");

Server response:

Code:

HTTP/1.1 200 OK
Date: Thu, 12 Mar 2009 01:26:34 GMT
Server: Apache/2.2.3 (CentOS)
Last-Modified: Tue, 15 Nov 2005 13:24:10 GMT
ETag: "b80f4-1b6-80bfd280"
Accept-Ranges: bytes
Content-Length: 438
Connection: close
Content-Type: text/html; charset=UTF-8

<HTML>
<HEAD>
<TITLE>Example Web Page</TITLE>
</HEAD> 
<body>  
<p>You have reached this web page by typing &quot;example.com&quot;,
&quot;example.net&quot;, or &quot;example.org&quot; into your web browser.</p>
<p>These domain names are reserved for use in documentation and are not available 
for registration. See <a href="http://www.rfc-editor.org/rfc/rfc2606.txt">RFC 2606</a>, Section 3.</p>
</BODY>
</HTML>

**happyclown** · 03-11-2009

And here is my program, if any newbie wants to learn from it.

Code:

#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdio.h>
#include <stdlib.h>

#define STORAGE_LEN 1000
#define DEFAULT_PORT "80"

char storage[STORAGE_LEN];
SOCKET ConnectSocket = INVALID_SOCKET;

void write_to_file(char *storage)
{
	FILE *p_openfile = fopen("c:\\programs\\networking\\webpagecontent.txt" , "a+");
	fprintf(p_openfile, "%s\n", storage);
	fclose(p_openfile);
}

int main(void)
{
	
	WSADATA wsaData;
	char ServerName[40] = "www.example.com";
//	char FilePath[40] = "/index.html";

	int iResult;
	struct addrinfo *result = NULL,
				*ptr = NULL,
				hints;

	// Initialize Winsock
	iResult = WSAStartup(MAKEWORD(2,2), &wsaData);
	if(iResult != 0) {
		printf("WSAStartup failed: %d\n", iResult);
		return 1;
	}

	ZeroMemory(&hints, sizeof(hints));
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_protocol = IPPROTO_TCP;

	// Resolve the server address and port
	iResult = getaddrinfo(ServerName, DEFAULT_PORT, &hints, &result);
	if(iResult != 0) {
		printf("getaddrinfo failed: %d\n", iResult);
		WSACleanup();
		return 1;
	}

	// Attempt to connect to an address until one succeeds
	for(ptr = result; ptr != NULL; ptr = ptr->ai_next) {
		
		// Create a socket for connecting to the server
		ConnectSocket = socket(ptr->ai_family, ptr->ai_socktype, ptr->ai_protocol);
		if(ConnectSocket == INVALID_SOCKET) {
			printf("Error at socket(): %ld\n", WSAGetLastError());
			freeaddrinfo(result);
			WSACleanup();
			return 1;
		}

	// Connect to server
	iResult = connect(ConnectSocket, ptr->ai_addr, (int)ptr->ai_addrlen);
	if(iResult == SOCKET_ERROR) {
		closesocket(ConnectSocket);
		ConnectSocket = INVALID_SOCKET;
		continue;
	}
	break;
}

	freeaddrinfo(result);

	if(ConnectSocket == INVALID_SOCKET) {
		printf("Unable to connect to the server!\n");
		return 1;
	}

	strcpy(storage,"GET / HTTP/1.1\r\n");
	strcat(storage, "User-Agent: Opera/9.27 (Windows NT 5.1; U; en)");
	strcat(storage, "\r\n");
	strcat(storage, "Host: www.example.com");
	strcat(storage, "\r\n");
	strcat(storage, "Accept: text/html, application/xml;q=0.9, application/xhtml+xml, image/png, image/jpeg, image/gif, image/x-xbitmap, */ *;q=0.1");
	strcat(storage, "\r\n");
	strcat(storage, "Accept-Language: en-US,en;q=0.9\r\nAccept-Charset: iso-8859-1, utf-8, utf-16, *;q=0.1");
	strcat(storage, "\r\n");
	strcat(storage, "Accept-Encoding: deflate, gzip, x-gzip, identity, *;q=0");
	strcat(storage, "\r\n");
	strcat(storage, "Connection: Keep-Alive");
	strcat(storage, "\r\n\r\n");

	printf("%s", storage);

	// Send an initial buffer
	
	iResult = send(ConnectSocket,storage,sizeof(storage),0);
	if (iResult == SOCKET_ERROR) {
        printf("send failed: %d\n", WSAGetLastError());
        closesocket(ConnectSocket);
        WSACleanup();
        return 1;
    }

	printf("Bytes Sent: %ld\n", iResult);

	// shutdown the connection since no more data will be sent
    iResult = shutdown(ConnectSocket, SD_SEND);
    if (iResult == SOCKET_ERROR) {
        printf("shutdown failed: %d\n", WSAGetLastError());
        closesocket(ConnectSocket);
        WSACleanup();
        return 1;
    }
	
	sprintf(storage, "shutdown = %d\n", iResult);
	write_to_file(storage);

	do {
		iResult = recv(ConnectSocket,storage,STORAGE_LEN,0);
		if ( iResult > 0 ) {
			write_to_file(storage);
			printf("Bytes received: %d\n", iResult);
		}
		else if ( iResult == 0 )
			printf("Connection closed\n");
		else
			printf("recv failed: %d\n", WSAGetLastError());

    } while( iResult > 0 );

	// cleanup
    closesocket(ConnectSocket);
    WSACleanup();

	return 0;
}

**MK27** · 03-12-2009

Originally Posted by happyclown

Well, I couldn't find any windows console application user-agents in that list, so I just used Opera as the user-agent.

If there were you would still be better off using "Opera" as the name -- some servers will reject requests from "all user-agents except XXX"

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