server_utils.c

/*
 * Network computing
 * 		Assignment 2: A HTTP program
 *      Written by Tran Quoc Hoan
 *			programmed by milestones method (step by step)
 *		
 *		ServerUtils.c		
 * 			Connect socket, socket handle
*/
#include <stdio.h>
#include <string.h>		/* for memset() function */
#include <stdlib.h>
#include <time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <signal.h>
#include <sys/wait.h>
#include <netdb.h>

#include "server_utils.h"
#include "request.h"
#include "router.h"
#include "mime.h"

#define TRUE 1
#define FALSE 0
#define WORK_DIR "/var/www"

extern router *rtr;
/* Error handling */
void err_handle( char * msg ) {
	perror( msg );
	exit ( EXIT_FAILURE );
}

/* Send home page */
void send_home( int sock ) {
	char outbuf[ MAXBUF + 1];
	memset( &outbuf, 0, sizeof(outbuf) );
	
	// get time now
	time_t timer = time( NULL );
	struct tm *date = localtime( &timer );
    
	snprintf( outbuf, sizeof(outbuf), 
  	    "HTTP/1.0 200 OK\r\n"
  	    "Server: %s\r\n"
  	    "Content-Type:text/html\r\n"
		"Date: %s\r\n"
		"Connection: Closed\r\n"
		"<font color=red><h1>404 Not Available.</h1></font>\r\n", SERVER,
		asctime( date ) );
    send( sock, outbuf, (int)strlen(outbuf), 0);
#ifdef DEBUG
	printf("Finish send_home \n");
#endif
	return;
}

/* Send html header */
void send_header( int sock, char *fmime ) 
{
	if(sock < -1 || fmime == NULL)
	{
		printf("Error: Invalid Socket or mime type\n");
		return;
	}
	char outbuf[ MAXBUF + 1];
	memset( &outbuf, 0, sizeof(outbuf) );
	
	// get time now
	time_t timer = time( NULL );
	struct tm *date = localtime( &timer );
    
	snprintf( outbuf, sizeof(outbuf), 
  	    "HTTP/1.0 200 OK\r\n"
  	    "Server: %s\r\n"
  	    "Content-Type: %s\r\n"
  	    "Connection: Closed\r\n"
		"Date: %s\r\n", SERVER, fmime, asctime( date ) );
    send( sock, outbuf, (int)strlen(outbuf), 0);
#ifdef DEBUG
	printf("Finish send_header \n");
#endif
	return;
}

/* Send html data */
void send_data( int sock, FILE* fp ) {
	int len;
	char outbuf[ MAXBUF + 1];
	memset( &outbuf, 0, sizeof(outbuf) );
	
	while ( !feof(fp) ) {
		len = fread( outbuf, 1, sizeof( outbuf ), fp );
		outbuf[len] ='\0';
		send ( sock, outbuf, len, 0 );
	}
#ifdef DEBUG
	printf("Finish send_data \n");
#endif
	return;
}

/* Send html file */
void send_html( int sock, const char* FILENAME ) {
	FILE* fp;
	fp = fopen( FILENAME, "r" ); 
	if ( fp == NULL ) {
		// send html header only
		send_home( sock );
	} else {
		send_header( sock, "text/html" );
		send_data( sock, fp );
		fclose( fp );
	}
#ifdef DEBUG
	printf("Finish send_html \n");
#endif
	return;
}
void send_static_file(int sock, const char *filename)
{
	FILE *fp=NULL;
	fp = fopen(filename, "r");
	if(fp == NULL)
	{
		send_home(sock);
	}
	else
	{
		send_header( sock, get_mime_type(filename) );
		send_data( sock, fp );
		fclose( fp );
	}
}
/* Handle for each client */
int client_handle( Client *c ) {
  	/* recv(), send(), close() */

  	// recv()
	char inbuf[ MAXBUF + 1];
	//char *inbuf;
    memset( &inbuf, 0, sizeof(inbuf) );
    struct timeval timeout;      
    timeout.tv_sec = 30;
    timeout.tv_usec = 0;
	printf("Serving client (IP:port)%s:%d\n",c->IP,c->port);
    if (setsockopt (c->socket, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout, sizeof(timeout)) < 0)
        printf("setsockopt failed\n");

    if (setsockopt (c->socket, SOL_SOCKET, SO_SNDTIMEO, (char *)&timeout, sizeof(timeout)) < 0)
        printf("setsockopt failed\n");
    if ( recv( c->socket, inbuf, sizeof(inbuf), 0 ) < 0 ) {
    	close( c->socket );
		perror("recv");
		return FALSE;
    };     

#ifdef DEBUG
	printf("Buffer--->\n");
    printf("%s\n", inbuf );
    printf("==========\n");
#endif
	
	req *r = parse_request(inbuf);
	if(r==NULL)
	{
	    printf("Unable to parse request\n");
	    return(FALSE);
	}
#ifdef DEBUG
	printf("method %s uri %s proto %s \n",r->method,r->uri,r->protocol);
#endif
	
	if(do_router(rtr,c->socket,r)==-1)
	{
		//try static service
		// here we should check if uri is a file
		// if so then we will only allow "html,js,css,txt" extension
		// else we will handover to router
		char file_mime[100];
		strcpy(file_mime,get_mime_type(r->uri));
		if(strcasecmp(file_mime,"text/plain")==0 || strcasecmp(file_mime,"text/css")==0 \
		|| strcasecmp(file_mime,"text/html")==0 || strcasecmp(file_mime,"application/javascript")==0)
		{
			char request_file[1024]="";
			strcpy(request_file,WORK_DIR); // append working directory
			strcat(request_file,"/static");
			strcat(request_file,r->uri);
			send_static_file(c->socket,request_file); 
		}
		else
			send_home(c->socket);
	}
	
		
	/* the following are for static file serving
	if(strcasecmp(r->method,"GET")==0)
	    do_get(c->socket,r);
	else if(strcasecmp(r->method,"POST")==0)
	    do_post(c->socket,r);
	else if(strcasecmp(r->method,"PUT")==0)
	    do_put(c->socket,r);
	else if(strcasecmp(r->method,"DELETE")==0)
	    do_del(c->socket,r);
	else if(strcasecmp(r->method,"HEAD")==0)
	    do_head(c->socket,r);
	else
	    do_unknown(c->socket,r);
	*/
    if(r)
    {
		if(r->payload)
		{
			free(r->payload);
			r->payload = NULL;
		}
		free(r);
		r = NULL;
    }
	return TRUE;
}

void do_get(int sock,req *r)
{
    char request_file[1024]="";
    strcpy(request_file,WORK_DIR); // append working directory
    // for the time being we will serv only disk files no virtual resource
    //printf("%s\n",r->uri);
    // we dont allow 2 dots consecutively in url
    if(strstr(r->uri,".."))
    {
		do_unknown(sock, r);
		return;
	}
	if(!strncmp(r->uri,"/",strlen("/")) && (strlen(r->uri) == 1 ) ) 
    {
	// landing page or resource
	// for the time being index.html
		strcat(request_file ,"/index.html");
    }
    else
    {
	//	strcpy(request_file,WORK_DIR);
	
		strcat(request_file,r->uri);
    }
    //printf("request file = %s\n",request_file);
    send_html(sock,request_file);
}
void do_unknown(int sock, req* r)
{
    char outbuf[ MAXBUF + 1];
    memset( &outbuf, 0, sizeof(outbuf) );
    // get time now
    time_t timer = time( NULL );
    struct tm *date = localtime( &timer );
    snprintf( outbuf, sizeof(outbuf), \
    "HTTP/1.0 200 OK\r\n" \
  	    "Content-Type:text/html\r\n" \
		"Date: %s\r\n" \
		"<font color=red><h1>HELLO! Hacker! The feature is NOT Implemented yet.</h1></font>\r\n", \
		asctime( date ) );
    send( sock, outbuf, (int)strlen(outbuf), 0);
}
void do_post(int sock,req *r)
{
    //do_unknown(sock,r);
    printf("payload = %s \n",r->payload);
    send_header(sock,"text/plain");
}

void do_put(int sock,req *r)
{
    //do_unknown(sock,r);
    printf("File tobe created %s%s\n",WORK_DIR,r->uri);
    printf("With content--->\n%s\n",r->payload);
}

void do_del(int sock,req *r)
{
    do_unknown(sock,r);
}
void do_head(int sock,req *r)
{
    //do_unknown(sock,r);
    send_header(sock,"text/plain");
}