ant-http/http_server.c

#include "http_server.h"
/**********************************************************************/
/* A request has caused a call to accept() on the server port to
* return.  Process the request appropriately.
* Parameters: the socket connected to the client */
/**********************************************************************/
void accept_request(int client)
{
	char buf[1024];
	int numchars;
	char method[255];
	char url[255];
	char path[512];
	size_t i, j;
	struct stat st;

	char *query_string = NULL;

	numchars = get_line(client, buf, sizeof(buf));
	i = 0; j = 0;
	while (!ISspace(buf[j]) && (i < sizeof(method) - 1))
	{
		method[i] = buf[j];
		i++; j++;
	}
	method[i] = '\0';

	if (strcasecmp(method, "GET") && strcasecmp(method, "POST"))
	{
		unimplemented(client);
		return;
	}


	i = 0;
	while (ISspace(buf[j]) && (j < sizeof(buf)))
		j++;
	while (!ISspace(buf[j]) && (i < sizeof(url) - 1) && (j < sizeof(buf)))
	{
		url[i] = buf[j];
		i++; j++;
	}
	url[i] = '\0';

	if (strcasecmp(method, "GET") == 0)
	{
		query_string = url;
		while ((*query_string != '?') && (*query_string != '\0'))
			query_string++;
		if (*query_string == '?')
		{
			*query_string = '\0';
			query_string++;
		}
	}

	sprintf(path, server_config.htdocs);
	strcat(path, url);
	//LOG("Path %s\n", path);
	if (path[strlen(path) - 1] == '/')
		strcat(path, "index.html");
	if (stat(path, &st) == -1) {

		if(execute_plugin(client,url,method,query_string) < 0)
			not_found(client);
	}
	else
	{
		if (S_ISDIR(st.st_mode))
			strcat(path, "/index.html");
		serve_file(client, path);

	}

	close(client);
}

/**********************************************************************/
/* Inform the client that a request it has made has a problem.
* Parameters: client socket */
/**********************************************************************/
void bad_request(int client)
{
	char buf[1024];

	sprintf(buf, "HTTP/1.0 400 BAD REQUEST\r\n");
	send(client, buf, sizeof(buf), 0);
	sprintf(buf, "Content-type: text/html\r\n");
	send(client, buf, sizeof(buf), 0);
	sprintf(buf, "\r\n");
	send(client, buf, sizeof(buf), 0);
	sprintf(buf, "<P>Your browser sent a bad request, ");
	send(client, buf, sizeof(buf), 0);
	sprintf(buf, "such as a POST without a Content-Length.\r\n");
	send(client, buf, sizeof(buf), 0);
}

/**********************************************************************/
/* Put the entire contents of a file out on a socket.  This function
* is named after the UNIX "cat" command, because it might have been
* easier just to do something like pipe, fork, and exec("cat").
* Parameters: the client socket descriptor
*             FILE pointer for the file to cat */
/**********************************************************************/
void __b(int client, const unsigned char* data, int size)
{
	char buf[BUFFLEN];
	int sent = 0;
	int buflen = 0;
	if(size <= BUFFLEN)
		send(client,data,size,0);
	else
	{
		while(sent < size)
		{
			if(size - sent > BUFFLEN)
				buflen = BUFFLEN;
			else
				buflen = size - sent;
			memcpy(buf,data+sent,buflen);
			send(client,buf,buflen,0);
			sent += buflen;
		}	
	}
}
void catb(int client, FILE* ptr)
{
	unsigned char buffer[BUFFLEN];
	while(!feof(ptr))
	{
		fread(buffer,BUFFLEN,1,ptr);
		__b(client,buffer,BUFFLEN);
	}
	fclose(ptr);
}
void cat(int client, FILE *resource)
{
	char buf[1024];

	fgets(buf, sizeof(buf), resource);
	while (!feof(resource))
	{
		send(client, buf, strlen(buf), 0);
		fgets(buf, sizeof(buf), resource);
	}


}

/**********************************************************************/
/* Inform the client that a CGI script could not be executed.
* Parameter: the client socket descriptor. */
/**********************************************************************/
void cannot_execute(int client)
{
	char buf[1024];

	sprintf(buf, "HTTP/1.0 500 Internal Server Error\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "Content-type: text/html\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "<P>Error prohibited CGI execution.\r\n");
	send(client, buf, strlen(buf), 0);
}

/**********************************************************************/
/* Print out an error message with perror() (for system errors; based
* on value of errno, which indicates system call errors) and exit the
* program indicating an error. */
/**********************************************************************/
void error_die(const char *sc)
{
	perror(sc);
	exit(1);
}

/**********************************************************************/
/* Get a line from a socket, whether the line ends in a newline,
* carriage return, or a CRLF combination.  Terminates the string read
* with a null character.  If no newline indicator is found before the
* end of the buffer, the string is terminated with a null.  If any of
* the above three line terminators is read, the last character of the
* string will be a linefeed and the string will be terminated with a
* null character.
* Parameters: the socket descriptor
*             the buffer to save the data in
*             the size of the buffer
* Returns: the number of bytes stored (excluding null) */
/**********************************************************************/
int get_line(int sock, char *buf, int size)
{
	int i = 0;
	char c = '\0';
	int n;

	while ((i < size - 1) && (c != '\n'))
	{
		n = recv(sock, &c, 1, 0);
		/* DEBUG printf("%02X\n", c); */
		if (n > 0)
		{
			if (c == '\r')
			{
				n = recv(sock, &c, 1, MSG_PEEK);
				/* DEBUG printf("%02X\n", c); */
				if ((n > 0) && (c == '\n'))
					recv(sock, &c, 1, 0);
				else
					c = '\n';
			}
			buf[i] = c;
			i++;
		}
		else
			c = '\n';
	}
	buf[i] = '\0';

	return(i);
}

/**********************************************************************/
/* Return the informational HTTP headers about a file. */
/* Parameters: the socket to print the headers on
*             the name of the file */
/**********************************************************************/
void headers(int client, const char *filename)
{
	char buf[1024];
	//printf("Mime %s\n", mime(filename));
	strcpy(buf, "HTTP/1.0 200 OK\r\n");
	send(client, buf, strlen(buf), 0);
	strcpy(buf, SERVER_STRING);
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "Content-Type: %s\r\n",mime(filename));
	send(client, buf, strlen(buf), 0);
	strcpy(buf, "\r\n");
	send(client, buf, strlen(buf), 0);
}

/**********************************************************************/
/* Give a client a 404 not found status message. */
/**********************************************************************/
void not_found(int client)
{
	char buf[1024];

	sprintf(buf, "HTTP/1.0 404 NOT FOUND\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, SERVER_STRING);
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "Content-Type: text/html\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "<HTML><TITLE>Not Found</TITLE>\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "<BODY><P>The server could not fulfill\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "your request because the resource specified\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "is unavailable or nonexistent.\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "</BODY></HTML>\r\n");
	send(client, buf, strlen(buf), 0);
}

/**********************************************************************/
/* Send a regular file to the client.  Use headers, and report
* errors to client if they occur.
* Parameters: a pointer to a file structure produced from the socket
*              file descriptor
*             the name of the file to serve */
/**********************************************************************/
void serve_file(int client, const char *filename)
{
	FILE *resource = NULL;
	int numchars = 1;
	char buf[1024];

	buf[0] = 'A'; buf[1] = '\0';
	while ((numchars > 0) && strcmp("\n", buf))  /* read & discard headers */
		numchars = get_line(client, buf, sizeof(buf));

	resource = fopen(filename, "rb");
	if (resource == NULL)
		not_found(client);
	else
	{
		headers(client, filename);
		if(is_bin(filename))
			catb(client,resource);
		else
			cat(client, resource);
	}
	fclose(resource);
}

/**********************************************************************/
/* This function starts the process of listening for web connections
* on a specified port.  If the port is 0, then dynamically allocate a
* port and modify the original port variable to reflect the actual
* port.
* Parameters: pointer to variable containing the port to connect on
* Returns: the socket */
/**********************************************************************/
int startup(unsigned *port)
{
	int httpd = 0;
	struct sockaddr_in name;

	httpd = socket(PF_INET, SOCK_STREAM, 0);
	if (httpd == -1)
		error_die("socket");
	memset(&name, 0, sizeof(name));
	name.sin_family = AF_INET;
	name.sin_port = htons(*port);
	name.sin_addr.s_addr = htonl(INADDR_ANY);
	if (bind(httpd, (struct sockaddr *)&name, sizeof(name)) < 0)
		error_die("bind");
	if (*port == 0)  /* if dynamically allocating a port */
	{
		socklen_t namelen = sizeof(name);
		if (getsockname(httpd, (struct sockaddr *)&name, &namelen) == -1)
			error_die("getsockname");
		*port = ntohs(name.sin_port);
	}
	if (listen(httpd, 5) < 0)
		error_die("listen");
	return(httpd);
}

/**********************************************************************/
/* Inform the client that the requested web method has not been
* implemented.
* Parameter: the client socket */
/**********************************************************************/
void unimplemented(int client)
{
	char buf[1024];

	sprintf(buf, "HTTP/1.0 501 Method Not Implemented\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, SERVER_STRING);
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "Content-Type: text/html\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "<HTML><HEAD><TITLE>Method Not Implemented\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "</TITLE></HEAD>\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "<BODY><P>HTTP request method not supported.\r\n");
	send(client, buf, strlen(buf), 0);
	sprintf(buf, "</BODY></HTML>\r\n");
	send(client, buf, strlen(buf), 0);
}