path: root/src/hook_lib/file_hook.c

#define _GNU_SOURCE

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <time.h>

#include <dlfcn.h>
#include <pthread.h>

#include <dirent.h>

#define _FCNTL_H
#include <bits/fcntl.h>

#include <bits/stat.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/un.h>

#define MAXPATHLEN PATH_MAX
#define MAXSOCKETPATHLEN 108
#define MAXFILEBUFFLEN 2048

#define MAXSOCKETMSGLEN 8192
#define MAXENVSIZE 65536
#define MAXENVITEMSIZE 256

#define MAXARGS 1024
//extern int errorno;

pthread_mutex_t socketblock = PTHREAD_MUTEX_INITIALIZER;

int (*_open)(const char * pathname, int flags, ...);
int (*_open64)(const char * pathname, int flags, ...);
FILE * (*_fopen)(const char *path, const char *mode);
FILE * (*_fopen64)(const char *path, const char *mode);
ssize_t (*_read)(int fd, void *buf, size_t count);
ssize_t (*_write)(int fd, const void *buf, size_t count);
size_t (*_fread)(void *ptr, size_t size, size_t nmemb, FILE *stream);
size_t (*_fwrite)(const void *ptr, size_t size, size_t nmemb, FILE *stream);

void *(*_mmap)(void *addr, size_t length, int prot, int flags,
                  int fd, off_t offset);

struct dirent * (*_readdir)(DIR *dirp);
struct dirent64 * (*_readdir64)(DIR *dirp);
int (*_readdir_r)(DIR *dirp, struct dirent *entry, 
				   struct dirent **result);
int (*_readdir64_r)(DIR *dirp, struct dirent64 *entry, 
				   struct dirent64 **result);


int (*_access)(const char *pathname, int mode);
int (*_euidaccess)(const char *pathname, int mode);
int (*_faccessat)(int dirfd, const char *pathname, int mode, int flags);

// these stat functions are only source level standart of glibc
// we no catch fxstat
int (*___xstat)(int vers, const char *name, struct stat *buf);
int (*___xstat64)(int vers, const char *name, struct stat64 *buf);
int (*___lxstat)(int vers, const char *name, struct stat *buf);
int (*___lxstat64)(int vers, const char *name, struct stat64 *buf);

int (*_execve)(const char *filename, char *const argv[],char *const envp[]);
int (*_execv)(const char *path, char *const argv[]);
int (*_execvp)(const char *file, char *const argv[]);
int (*_execvpe)(const char *file, char *const argv[], char *const envp[]);

int (*_fexecve)(int fd, char *const argv[], char *const envp[]);

int (*_system)(const char *command);

pid_t (*_fork)();

int (*_setenv)(const char *name, const char *value, int overwrite);
int (*_close)(int fd); // we hooking this, because some programs closes our socket

int log_socket=-1;

char ld_preload_orig[MAXPATHLEN];
char log_socket_name[MAXSOCKETPATHLEN];

char ld_preload_env[MAXENVITEMSIZE]; // value: LD_PRELOAD=ld_preload_orig
char log_socket_env[MAXENVITEMSIZE]; // value: LOG_SOCKET=log_socket_name

void __doconnect(){
  if(strlen(log_socket_name)>=MAXSOCKETPATHLEN) {
	fprintf(stderr,"Unable to create a unix-socket %s: socket name is too long,exiting\n", log_socket_name);
	exit(1);
  }
	  
  log_socket=socket(AF_UNIX, SOCK_SEQPACKET, 0);
  if(log_socket==-1) {
	fprintf(stderr,"Unable to create a unix-socket %s: %s\n", log_socket_name, strerror(errno));
	exit(1);
  }
  
  struct sockaddr_un serveraddr;
  memset(&serveraddr, 0, sizeof(serveraddr));
  serveraddr.sun_family = AF_UNIX;
  strcpy(serveraddr.sun_path, log_socket_name);
  

  int ret=connect(log_socket, (struct sockaddr *)&serveraddr, SUN_LEN(&serveraddr));
  if(ret==-1) {
	fprintf(stderr,"Unable to connect a unix-socket %s: %s\n",log_socket_name, strerror(errno));
	fflush(stderr);
	//execlp("/bin/bash","/bin/bash",NULL);
	exit(1);
  }
}

void __dodisconnect() {
  close(log_socket); 
}

void __doreconnect() {
  __doconnect();
  __dodisconnect();
}

// this fucnction executes when library is loaded
void _init() {
  char *log_socket_val=getenv("LOG_SOCKET");
  
  if(log_socket_val==NULL) {
	fprintf(stderr,"LOG_SOCKET environment variable isn't defined."
					"Are this library launched by server?\n");
	exit(1);
  }

  if(strlen(log_socket_val)>=MAXSOCKETPATHLEN) {
	fprintf(stderr,"Unable to create a unix-socket %s: socket name is too long,exiting\n", log_socket_name);
	exit(1);
  }
  
  strcpy(log_socket_name,log_socket_val);

  if(getenv("LD_PRELOAD")==NULL) {
	fprintf(stderr,"Unable to find LD_PRELOAD environment variable. "
	"Library will load only with this variable defined");
	exit(1);
  }

  strcpy(ld_preload_orig,getenv("LD_PRELOAD"));

  _open = (int (*)(const char * pathname, int flags, ...)) dlsym(RTLD_NEXT, "open");
  _open64 = (int (*)(const char * pathname, int flags, ...)) dlsym(RTLD_NEXT, "open64");

  _fopen = (FILE * (*)(const char *path, const char *mode)) dlsym(RTLD_NEXT, "fopen");
  _fopen64 = (FILE * (*)(const char *path, const char *mode)) dlsym(RTLD_NEXT, "fopen64");

  _read= (ssize_t (*)(int fd, void *buf, size_t count)) dlsym(RTLD_NEXT, "read");
  _write= (ssize_t (*)(int fd, const void *buf, size_t count)) dlsym(RTLD_NEXT, "write");

  _mmap=(void* (*)(void *addr, size_t length, int prot, int flags,
                  int fd, off_t offset)) dlsym(RTLD_NEXT, "mmap");
  _readdir=(struct dirent * (*)(DIR *dirp)) dlsym(RTLD_NEXT, "readdir");
  _readdir64=(struct dirent64 * (*)(DIR *dirp)) dlsym(RTLD_NEXT, "readdir64");
  _readdir_r=(int (*)(DIR *dirp, struct dirent *entry, 
				   struct dirent **result)) dlsym(RTLD_NEXT, "readdir_r");
  _readdir64_r=(int (*)(DIR *dirp, struct dirent64 *entry, 
				   struct dirent64 **result)) dlsym(RTLD_NEXT, "readdir64_r");

  _access=(int (*)(const char *pathname, int mode)) dlsym(RTLD_NEXT, "access");
  _euidaccess=(int (*)(const char *pathname, int mode)) dlsym(RTLD_NEXT, "euidaccess");
  _faccessat=(int(*)(int dirfd, const char *pathname, int mode, int flags)) dlsym(RTLD_NEXT, "faccessat");
			
  
  ___xstat=(int (*)(int vers, const char *name, struct stat *buf)) dlsym(RTLD_NEXT, "__xstat");
  ___xstat64=(int (*)(int vers, const char *name, struct stat64 *buf)) dlsym(RTLD_NEXT, "__xstat64");
  ___lxstat=(int (*)(int vers, const char *name, struct stat *buf)) dlsym(RTLD_NEXT, "__lxstat");			   
  ___lxstat64=(int (*)(int vers, const char *name, struct stat64 *buf)) dlsym(RTLD_NEXT, "__lxstat64");

  _fork = (pid_t (*)()) dlsym(RTLD_NEXT, "fork");
  
  _execve = (int (*)(const char *filename, char *const argv[],char *const envp[])) dlsym(RTLD_NEXT, "execve");
  _execv = (int (*)(const char *path, char *const argv[])) dlsym(RTLD_NEXT, "execv");
  _execvp = (int (*)(const char *file, char *const argv[])) dlsym(RTLD_NEXT, "execvp");
  _execvpe = (int (*)(const char *file, char *const argv[], char *const envp[])) dlsym(RTLD_NEXT, "execvpe");
  
  _fexecve = (int (*)(int fd, char *const argv[], char *const envp[])) dlsym(RTLD_NEXT, "fexecve");

  _system = (int (*)(const char *command)) dlsym(RTLD_NEXT, "system");
  
  
  _setenv=(int (*)(const char *name, const char *value, int overwrite)) dlsym(RTLD_NEXT, "setenv");
  _close= (int (*)(int fd)) dlsym(RTLD_NEXT, "close");

  
  if(_open==NULL || _open64==NULL || 
	 _fopen==NULL || _fopen64==NULL || 
	  _read==NULL || _write==NULL || _mmap==NULL || 
	  _readdir==NULL || _readdir64 == NULL || _readdir_r==NULL || 
	  _readdir64_r==NULL ||
	  _access==NULL || _euidaccess==NULL || _faccessat==NULL || 
	  _fork==NULL || 
	  _execve==NULL || _execv==NULL || _execvp==NULL || _execvpe==NULL || 
	  _fexecve==NULL || _system==NULL || _setenv==NULL || _close==NULL) {
	  fprintf(stderr,"Failed to load original functions of hook\n");
	  exit(1);
  }
  
  snprintf(ld_preload_env,MAXENVITEMSIZE,"LD_PRELOAD=%s",ld_preload_orig);
  snprintf(log_socket_env,MAXENVITEMSIZE,"LOG_SOCKET=%s",log_socket_name);

  
  __doconnect();
} 

void _fini() {
  __dodisconnect();
}

/*
 * Format of log string: time event filename stage result/err
*/
static int __raw_log_event(const char *event_type, const char *filename, char *result,int err, char* stage) {
  char msg_buff[MAXSOCKETMSGLEN];
  int bytes_to_send;
  if(strcmp(result,"ERR")==0) {
	bytes_to_send=snprintf(msg_buff,MAXSOCKETMSGLEN,"%lld%c%s%c%s%c%s%c%s/%d",
	  (unsigned long long)time(NULL),0,event_type,0,filename,0,stage,0,result,err);
  } else {
	bytes_to_send=snprintf(msg_buff,MAXSOCKETMSGLEN,"%lld%c%s%c%s%c%s%c%s",
	  (unsigned long long)time(NULL),0,event_type,0,filename,0,stage,0,result);	
  }
  
  if(bytes_to_send>=MAXSOCKETMSGLEN) 
	return 0;
  
  if(send(log_socket,msg_buff,bytes_to_send,0)==-1) {
	__doreconnect(); // looks like our socket has been destroyed by logged program
					 // try to recreate it

	if(send(log_socket,msg_buff,bytes_to_send,0)==-1)
	  return 0;
  }
  
  return 1;
}

/*
 * Log an event
*/
static int __log_event(const char *event_type, const char *filename, char *result,int err, char* stage) {
  pthread_mutex_lock( &socketblock );
  int ret=__raw_log_event(event_type,filename,result,err,stage);
  pthread_mutex_unlock( &socketblock );
  return ret;
}

/*
 * Get a stage. Stage is from environment
*/
static char * __get_stage(){
  char *ret=getenv("EBUILD_PHASE");
  if(ret==NULL)
	return "unknown";
  return ret;
}

/*
 * Get full path by fd
*/
ssize_t __get_path_by_fd(int fd, char *output, int output_len) {
  char path_to_fd_link[MAXPATHLEN];
  
  snprintf(path_to_fd_link,MAXPATHLEN,"/proc/self/fd/%d",fd);
  ssize_t bytes_num=readlink(path_to_fd_link,output,output_len-1);
  output[bytes_num]=0; // because readlink don't do this
  if(output[0]!='/') return -1; // some odd string like pipe:
  return bytes_num;
}

/*
 * Realpath. Resolved path is empty string on error. If path not exists, 
 * returns the path as is, but resolving current dir . Arguments must be not null
*/
char *myrealpath(const char *path, char *resolved){
  char *ret=realpath(path,resolved);
  if(ret!=NULL)
	return ret;
  
  if(path==NULL)
	goto error;
  
  // difficult case: error returned
  char *dest;

  if(path[0]!='/') {
	if(! getcwd(resolved,MAXPATHLEN-2))
	  goto error;

	dest= resolved+strlen(resolved);
	dest[0]='/';
	dest++; 
	dest[0]='\0';
  } else {
	dest = resolved;
  }
  
  char *border=resolved+MAXPATHLEN-1; // not crossing it and not stepping on it
  if(dest>=border)
	goto error;

  strncpy(dest, path, border-dest);
  
  return resolved;
	
error:
  resolved[0]=0;
  return NULL;
  
}


/*
 * Ask for event "alloweness"
*/
static int __is_event_allowed(const char *event_type,const char *filename, char* stage) {
  char answer[8];
  int bytes_recieved;
  //printf("asking %s\n",filename);
  
  pthread_mutex_lock( &socketblock );

  __raw_log_event(event_type,filename,"ASKING",0,stage);
  bytes_recieved=recv(log_socket,answer,8,0);

  if(bytes_recieved==-1) {
	__doreconnect(); // looks like our socket has been destroyed by logged program
				   // try to recreate it
	bytes_recieved=recv(log_socket,answer,8,0);
  }
  
  pthread_mutex_unlock( &socketblock );
  
  if(strcmp(answer,"ALLOW")==0) {
	return 1;
  } else if(strcmp(answer,"DENY")==0)
	return 0;
  else {
	fprintf(stderr,"Protocol error, text should be ALLOW or DENY, got: '%s' recv retcode=%d(%s)"
			" socket=%d",answer,bytes_recieved,strerror(errno),log_socket);
	exit(1);
  }
  return 0;
}

void __fixenv() {
  _setenv("LOG_SOCKET",log_socket_name,1);
  _setenv("LD_PRELOAD",ld_preload_orig,1);
  snprintf(ld_preload_env,MAXENVITEMSIZE,"LD_PRELOAD=%s",ld_preload_orig);
  snprintf(log_socket_env,MAXENVITEMSIZE,"LOG_SOCKET=%s",log_socket_name);
}
 
/*
 * Fixes LD_PRELOAD and LOG_SOCKET in envp and puts modified value in envp_new
*/
void __fixenvp(char *const envp[], char *envp_new[]) {
  int i;
  int j=0;
  for(i=0; envp[i] && i<MAXENVSIZE-3; i++) {
	if(strncmp(envp[i],"LD_PRELOAD=",11)==0)
	  continue;
	if(strncmp(envp[i],"LOG_SOCKET=",11)==0)
	  continue;
	envp_new[j++]=envp[i];
  }

  envp_new[j++]=ld_preload_env;
  envp_new[j++]=log_socket_env;
  envp_new[j]=NULL;
}
  
/*
 * Below are functions we hooking
 * The common strategy is: 
 * 1) ask python part for allowness 2) do call 3) tell a result
*/
int open(const char * path, int flags, mode_t mode) {
    int ret;
	char fullpath[MAXPATHLEN];
	myrealpath(path,fullpath);
	char *stage=__get_stage();
	if(! __is_event_allowed("open",fullpath,stage)) {
	  __log_event("open",fullpath,"DENIED",errno,stage);
	  errno=2; // not found
	  return -1;
	}
	
    ret=_open(path, flags, mode);
	int saved_errno=errno;

	if(ret==-1)
	  __log_event("open",fullpath,"ERR",errno,stage);
	else
	  __log_event("open",fullpath,"OK",0,stage);	  
	errno=saved_errno;
	
	return ret;
}

int open64(const char * path, int flags, mode_t mode) {
	int ret;
	char fullpath[MAXPATHLEN];
	myrealpath(path,fullpath);
	char *stage=__get_stage();
	if(! __is_event_allowed("open",fullpath,stage)) {
	  __log_event("open",path,"DENIED",errno,stage);
	  errno=2; // not found
	  return -1;
	}
	
    ret=_open64(path, flags, mode);

	int saved_errno=errno;
	if(ret==-1)
	  __log_event("open",fullpath,"ERR",errno,stage);
	else
	  __log_event("open",fullpath,"OK",0,stage);
	errno=saved_errno;
	
	return ret;
}

FILE *fopen(const char *path, const char *mode) {
	FILE *ret;
	char fullpath[MAXPATHLEN];
	myrealpath(path,fullpath);

	char *stage=__get_stage();
	if(! __is_event_allowed("open",fullpath,stage)) {
	  __log_event("open",path,"DENIED",errno,stage);
	  errno=2; // not found
	  return NULL;
	}

	ret=_fopen(path,mode);
	int saved_errno=errno;
	if(ret==NULL)
	  __log_event("open",fullpath,"ERR",errno,stage);
	else
	  __log_event("open",fullpath,"OK",0,stage);
	errno=saved_errno;
	return ret;
}

FILE *fopen64(const char *path, const char *mode) {
	FILE *ret;
	char fullpath[MAXPATHLEN];
	myrealpath(path,fullpath);

	char *stage=__get_stage();
	if(! __is_event_allowed("open",fullpath,stage)) {
	  __log_event("open",fullpath,"DENIED",errno,stage);
	  errno=2; // not found
	  return NULL;
	}

	ret=_fopen64(path,mode);
	int saved_errno=errno;

	if(ret==NULL)
	  __log_event("open",fullpath,"ERR",errno,stage);
	else
	  __log_event("open",fullpath,"OK",0,stage);

	errno=saved_errno;
	return ret;
}

ssize_t read(int fd, void *buf, size_t count){
  ssize_t ret=_read(fd,buf,count);
  int saved_errno=errno;
  char *stage=__get_stage();

  char fullpath[MAXPATHLEN];
  ssize_t path_size=__get_path_by_fd(fd,fullpath,MAXPATHLEN);
  if(path_size!=-1) {
	if(ret==-1)
	  __log_event("read",fullpath,"ERR",errno,stage);
	else
	  __log_event("read",fullpath,"OK",0,stage);
  }
  
  errno=saved_errno;
  return ret;
}

ssize_t write(int fd,const void *buf, size_t count){
  ssize_t ret=_write(fd,buf,count);
  int saved_errno=errno;
  char *stage=__get_stage();
  char fullpath[MAXPATHLEN];
  ssize_t path_size=__get_path_by_fd(fd,fullpath,MAXPATHLEN);
  if(path_size!=-1){
	if(ret==-1)
	  __log_event("write",fullpath,"ERR",errno,stage);
	else
	  __log_event("write",fullpath,"OK",0,stage);
  }
  
  errno=saved_errno;
  return ret;
}

pid_t fork(void) {

  __fixenv();

  int ret=_fork();
  int saved_errno=errno;
  // we must to handle fork for reconnect a socket
  
  if(ret==0) {
	__doreconnect(); // reinit connection for children
					 // because now it is different processes
  } else {
	//fprintf(stderr,"fork new: %d LOG_SOCKET=%s\n", ret,getenv("LOG_SOCKET"));
	//sleep(3);
  }
  errno=saved_errno;
  return ret;
}


int execve(const char *filename, char *const argv[],
                  char *const envp[]) {
  char *stage=__get_stage();
  if(! __is_event_allowed("open",filename,stage)) {
	__log_event("open",filename,"DENIED",errno,stage);
	errno=2; // not found
	return -1;
  }

  if(access(filename, F_OK)!=-1)
	__log_event("read",filename,"OK",0,stage);
  else
	__log_event("open",filename,"ERR",2,stage);
  
  char *envp_new[MAXENVSIZE];
  __fixenvp(envp,envp_new);
	
  int ret=_execve(filename, argv, envp_new);
  
  return ret;
}

int execv(const char *path, char *const argv[]){
  char *stage=__get_stage();
  if(! __is_event_allowed("open",path,stage)) {
	__log_event("open",path,"DENIED",errno,stage);
	errno=2; // not found
	return -1;
  }


  if(access(path, F_OK)!=-1)
	__log_event("read",path,"OK",0,stage);
  else
	__log_event("open",path,"ERR",2,stage);

  // we can't just call __fixenv() here, it is not thread-safely
  char **old_env=__environ;
  char **new_env;

  new_env=malloc(MAXENVSIZE * sizeof(char *));
  __fixenvp(__environ,new_env);
  __environ=new_env;
    
  _execv(path,argv);
  
  free(new_env);
  __environ=old_env;
  
  return -1;
}

int execvp(const char *file, char *const argv[]){
  char *stage=__get_stage();
  if(strchr(file,'/')!=NULL) {
	if(! __is_event_allowed("open",file,stage)) {
	  __log_event("open",file,"DENIED",errno,stage);
	  errno=2; // not found
	  return -1;
	}
	
	if(access(file, F_OK)!=-1)
	  __log_event("read",file,"OK",0,stage);
	else
	  __log_event("open",file,"ERR",2,stage);
	
  } else {
	// TODO: may me repeat bash's PATH parsing logic here	
  }

  // we can't just call __fixenv() here, it is not thread-safely
  char **old_env=__environ;
  char **new_env;

  new_env=malloc(MAXENVSIZE * sizeof(char *));
  __fixenvp(__environ,new_env);
  __environ=new_env;
    
  _execvp(file,argv);
  
  free(new_env);
  __environ=old_env;
  
  return -1;
} 

int execvpe(const char *file, char *const argv[],
                  char *const envp[]){
  char *stage=__get_stage();

  if(strchr(file,'/')!=NULL) {
	if(! __is_event_allowed("open",file,stage)) {
	  __log_event("open",file,"DENIED",errno,stage);
	  errno=2; // not found
	  return -1;
	}
	
	if(access(file, F_OK)!=-1)
	  __log_event("read",file,"OK",0,stage);
	else
	  __log_event("open",file,"ERR",2,stage);
	
  } else {
	// TODO: may me repeat bash's PATH parsing logic here	
  }

  char *envp_new[MAXENVSIZE];
  __fixenvp(envp,envp_new);

  return _execvpe(file,argv,envp_new);  
}

int execl(const char *path, const char *arg, ...){
  char *stage=__get_stage();
  if(! __is_event_allowed("open",path,stage)) {
	__log_event("open",path,"DENIED",errno,stage);
	errno=2; // not found
	return -1;
  }

  if(access(path, F_OK)!=-1)
	__log_event("read",path,"OK",0,stage);
  else
	__log_event("open",path,"ERR",2,stage);

  // we can't just call __fixenv() here, it is not thread-safely
  char **old_env=__environ;
  char **new_env;

  new_env=malloc(MAXENVSIZE * sizeof(char *));
  __fixenvp(__environ,new_env);
  __environ=new_env;
    
  va_list ap;
  char * argv[MAXARGS+1];
  int i=0;
  
  va_start(ap,arg);
  while(arg!=0 && i<MAXARGS) {
	argv[i]=(char *)arg;
	i++;
	arg=va_arg(ap,const char *);
  }
  argv[i]=NULL;
  va_end(ap);
  
  _execv(path,argv);

  free(new_env);
  __environ=old_env;
  
  return -1;
}

int execlp(const char *file, const char *arg, ...) {
  char *stage=__get_stage();
  if(strchr(file,'/')!=NULL) {
	if(! __is_event_allowed("open",file,stage)) {
	  __log_event("open",file,"DENIED",errno,stage);
	  errno=2; // not found
	  return -1;
	}
	if(access(file, F_OK)!=-1)
	  __log_event("read",file,"OK",0,stage);
	else
	  __log_event("open",file,"ERR",2,stage);
  } else {
	// TODO: may me repeat bash's PATH parsing logic here	
  }

  // we can't just call __fixenv() here, it is not thread-safely
  char **old_env=__environ;
  char **new_env;

  new_env=malloc(MAXENVSIZE * sizeof(char *));
  __fixenvp(__environ,new_env);
  __environ=new_env;

  va_list ap;
  char * argv[MAXARGS+1];
  int i=0;
  
  va_start(ap,arg);
  while(arg!=0 && i<MAXARGS) {
	argv[i]=(char *)arg;
	i++;
	arg=va_arg(ap,const char *);
  }
  argv[i]=NULL;
  va_end(ap);

  _execvp(file,argv);
  free(new_env);
  __environ=old_env;
  
  return -1;

}

int execle(const char *path, const char *arg, ... ){
  char *stage=__get_stage();
  if(! __is_event_allowed("open",path,stage)) {
	__log_event("open",path,"DENIED",errno,stage);
	errno=2; // not found
	return -1;
  }

  if(access(path, F_OK)!=-1)
	__log_event("read",path,"OK",0,stage);
  else
	__log_event("open",path,"ERR",2,stage);
  
  va_list ap;
  char * argv[MAXARGS+1];
  argv[0]=(char *)arg;
  
  va_start(ap,arg);
  int i=0;
  while(argv[i++]!=NULL && i<MAXARGS) {
	argv[i]=(char *)va_arg(ap,const char *);
  }
  char **envp=(char **) va_arg(ap, const char *);
  
  char *envp_new[MAXENVSIZE];
  __fixenvp(envp,envp_new);
  
  va_end(ap);
  return _execve(path,argv,envp_new);
}

int fexecve(int fd, char *const argv[], char *const envp[]) {
  char *stage=__get_stage();

  char *envp_new[MAXENVSIZE];
  __fixenvp(envp,envp_new);
 
  char filename[MAXPATHLEN];
  ssize_t path_size=__get_path_by_fd(fd,filename,MAXPATHLEN);
  if(path_size==-1) 
	return _fexecve(fd, argv, envp_new);
  
  if(! __is_event_allowed("open",filename,stage)) {
	__log_event("open",filename,"DENIED",errno,stage);
	errno=2; // not found
	return -1;
  }

  if(access(filename, F_OK)!=-1)
	__log_event("read",filename,"OK",0,stage);
  else
	__log_event("open",filename,"ERR",2,stage);
	
  return _fexecve(fd, argv, envp_new);
}

int system(const char *command) {
  __fixenv();
	
  int ret=_system(command);
  
  return ret;
}

void *mmap(void *addr, size_t length, int prot, int flags,
                  int fd, off_t offset) {
  void *ret=_mmap(addr,length,prot,flags,fd,offset);
  char filename[MAXPATHLEN];
  if(fd!=-1 && __get_path_by_fd(fd,filename,MAXPATHLEN)!=-1) {
	char *stage=__get_stage();
	if(prot & PROT_READ || prot & PROT_EXEC)
	  __log_event("read",filename,"OK",0,stage);
	if(prot & PROT_WRITE)
	  __log_event("write",filename,"OK",0,stage);
  }
  return ret;
}

// directory reading hooks
// the strategy for all functions is basic: skip the file if it is blocked
// all function are in two very similar variants: 32bit and 64bit
struct dirent *readdir(DIR *dirp) {
  char *stage=__get_stage();
  struct dirent *ep;

  char dirpath[MAXPATHLEN];

  int fd;
  fd=dirfd(dirp);
  
  // get dirname in dirpath
  if (__get_path_by_fd(fd,dirpath,MAXPATHLEN)==-1)
	return _readdir(dirp);
  
  while((ep=_readdir(dirp))!=NULL) { 	// Hope that readdir is not looping
	char fullpath[MAXPATHLEN];	
	snprintf(fullpath,MAXPATHLEN,"%s/%s",dirpath,ep->d_name);

	char abspath[MAXPATHLEN];
	myrealpath(fullpath,abspath);

	if(! __is_event_allowed("open",abspath,stage)) {
	  //__log_event("open",abspath,"DENIED",errno,stage);
	    
	  continue;
	} else
	  break;
  }
  return ep;
}

struct dirent64 *readdir64(DIR *dirp) {
  char *stage=__get_stage();
  struct dirent64 *ep;

  char dirpath[MAXPATHLEN];

  int fd;
  fd=dirfd(dirp);
  
  // get dirname in dirpath
  if (__get_path_by_fd(fd,dirpath,MAXPATHLEN)==-1)
	return _readdir64(dirp);
  
  while((ep=_readdir64(dirp))!=NULL) { 	// Hope that readdir is not looping
	char fullpath[MAXPATHLEN];	
	snprintf(fullpath,MAXPATHLEN,"%s/%s",dirpath,ep->d_name);

	char abspath[MAXPATHLEN];
	myrealpath(fullpath,abspath);

	if(! __is_event_allowed("open",abspath,stage)) {
	  //__log_event("open",abspath,"DENIED",errno,stage);
	    
	  continue;
	} else
	  break;
  }
  return ep;
}


// next two functions are almost equal
int readdir_r(DIR *dirp, struct dirent *entry, struct dirent **result){
  char *stage=__get_stage();
  char dirpath[MAXPATHLEN];

  int fd;
  fd=dirfd(dirp);

  // get dirname in dirpath
  if (__get_path_by_fd(fd,dirpath,MAXPATHLEN)==-1)
	return _readdir_r(dirp, entry, result);

  int ret;
  
  while((ret=_readdir_r(dirp, entry, result))==0) {
	if(*result==NULL) {
	  break; // end of directory
	}
	
	char fullpath[MAXPATHLEN];	
	snprintf(fullpath,MAXPATHLEN,"%s/%s",dirpath,entry->d_name);
	
	char abspath[MAXPATHLEN];
	myrealpath(fullpath,abspath);
		
	if(! __is_event_allowed("open",abspath,stage)) {
	  //__log_event("open",abspath,"DENIED",errno,stage);
	    
	  continue;
	} else
	  break;
  }
  
  return ret;
}


int readdir64_r(DIR *dirp, struct dirent64 *entry, struct dirent64 **result){
  char *stage=__get_stage();
  char dirpath[MAXPATHLEN];

  int fd;
  fd=dirfd(dirp);

  // get dirname in dirpath
  if (__get_path_by_fd(fd,dirpath,MAXPATHLEN)==-1)
	return _readdir64_r(dirp, entry, result);

  int ret;
  
  while((ret=_readdir64_r(dirp, entry, result))==0) {
	if(*result==NULL) {
	  break; // end of directory
	}
	
	char fullpath[MAXPATHLEN];	
	snprintf(fullpath,MAXPATHLEN,"%s/%s",dirpath,entry->d_name);
	
	char abspath[MAXPATHLEN];
	myrealpath(fullpath,abspath);
		
	if(! __is_event_allowed("open",abspath,stage)) {
	  //__log_event("open",abspath,"DENIED",errno,stage);
	    
	  continue;
	} else
	  break;
  }
  
  return ret;
}


int __xstat (int vers, const char *name, struct stat *buf) {
  char *stage=__get_stage();

  char fullpath[MAXPATHLEN];
  myrealpath(name,fullpath);

  if(! __is_event_allowed("open",fullpath,stage)) {
	__log_event("open",fullpath,"DENIED",errno,stage);
	errno=2;
	return -1;
  }

  if(___xstat==NULL)
	return -1;
  
  return ___xstat(vers,name,buf);
}

int __xstat64 (int vers, const char *name, struct stat64 *buf) {
  char *stage=__get_stage();

  char fullpath[MAXPATHLEN];
  myrealpath(name,fullpath);

  if(! __is_event_allowed("open",fullpath,stage)) {
	__log_event("open",fullpath,"DENIED",errno,stage);
	errno=2;
	return -1;
  }

  if(___xstat64==NULL)
	return -1;
  
  return ___xstat64(vers,name,buf);
}


int __lxstat (int vers, const char *name, struct stat *buf) {
  char *stage=__get_stage();

  char fullpath[MAXPATHLEN];
  myrealpath(name,fullpath);
  
  if(! __is_event_allowed("open",fullpath,stage)) {
	__log_event("open",fullpath,"DENIED",errno,stage);
	errno = 2;
	return -1;
  }
	
  if(___lxstat==NULL)
	return -1;
  
  return ___lxstat(vers,name,buf);
}

int __lxstat64 (int vers, const char *name, struct stat64 *buf) {
  char *stage=__get_stage();

  char fullpath[MAXPATHLEN];
  myrealpath(name,fullpath);
  
  if(! __is_event_allowed("open",fullpath,stage)) {
	__log_event("open",fullpath,"DENIED",errno,stage);
	errno = 2;
	return -1;
  }
	
  if(___lxstat64==NULL)
	return -1;
  
  return ___lxstat64(vers,name,buf);
}


int access(const char *pathname, int mode) {
  char *stage=__get_stage();

  char fullpath[MAXPATHLEN];
  myrealpath(pathname,fullpath);
  
  if(! __is_event_allowed("open",fullpath,stage)) {
	__log_event("open",fullpath,"DENIED",errno,stage);
	errno = 2;
	return -1;
  }
	
  return _access(pathname,mode);
}

int euidaccess(const char *pathname, int mode) {
  char *stage=__get_stage();

  char fullpath[MAXPATHLEN];
  myrealpath(pathname,fullpath);
  
  if(! __is_event_allowed("open",fullpath,stage)) {
	__log_event("open",fullpath,"DENIED",errno,stage);
	errno = 2;
	return -1;
  }
	
  return _euidaccess(pathname,mode);
}

int faccessat(int dirfd, const char *pathname, int mode, int flags){
  char *stage=__get_stage();

  
  char filepath[MAXPATHLEN];
  char fullpath[MAXPATHLEN];
  int len=__get_path_by_fd(dirfd,filepath,MAXPATHLEN);
  if(len==-1) 
	filepath[0]=0;
  strcat(filepath,"/");
  strcat(filepath,pathname);
  myrealpath(filepath,fullpath);
  
  if(! __is_event_allowed("open",fullpath,stage)) {
	__log_event("open",fullpath,"DENIED",errno,stage);
	errno = 2;
	return -1;
  }
	
  return _faccessat(dirfd,pathname,mode,flags);
}


int setenv(const char *name, const char *value, int overwrite) {
	//printf ("   CHANGING name: %s, value: %s",name,value);
	if(strcmp(name,"LD_PRELOAD")==0 ||
	  strcmp(name,"LOG_SOCKET")==0) return -1;
	int ret=_setenv(name,value,overwrite);
	return ret;
}

//int putenv(char *string){
// 	fprintf(stderr,"putenv 1 pid=%d cmd=%s",getpid(),string);
//	fflush(stderr);
//
//	//return _system(command);
//	return 0;    
//}


int close(int fd) {
  if(fd!=log_socket) {
	return _close(fd);
  }
  return -1;
}