hooklib: hide blocked files in directories

1 files changed, 156 insertions, 2 deletions

diff --git a/src/hook_lib/file_hook.c b/src/hook_lib/file_hook.c
index 555d6dc..9f114ae 100644
--- a/src/hook_lib/file_hook.c
+++ b/src/hook_lib/file_hook.c
@@ -11,6 +11,8 @@
 #include <dlfcn.h>
 #include <pthread.h>
 
+#include <dirent.h>
+
 #define _FCNTL_H
 #include <bits/fcntl.h>
 
@@ -19,7 +21,7 @@
 #include <sys/socket.h>
 #include <sys/un.h>
 
-#define MAXPATHLEN 1024
+#define MAXPATHLEN PATH_MAX
 #define MAXSOCKETPATHLEN 108
 #define MAXFILEBUFFLEN 2048
 
@@ -44,6 +46,13 @@ 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 (*_execve)(const char *filename, char *const argv[],char *const envp[]);
 int (*_execv)(const char *path, char *const argv[]);
@@ -139,6 +148,12 @@ void _init() {
 
   _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");
 
   
   _fork = (pid_t (*)()) dlsym(RTLD_NEXT, "fork");
@@ -159,7 +174,9 @@ void _init() {
   
   if(_open==NULL || _open64==NULL || 
 	 _fopen==NULL || _fopen64==NULL || 
-	  _read==NULL || _write==NULL || _mmap==NULL ||
+	  _read==NULL || _write==NULL || _mmap==NULL || 
+	  _readdir==NULL || _readdir64 == NULL || _readdir_r==NULL || 
+	  _readdir64_r==NULL ||
 	  _fork==NULL || 
 	  _execve==NULL || _execv==NULL || _execvp==NULL || _execvpe==NULL || 
 	  _fexecve==NULL || _system==NULL || _setenv==NULL || _close==NULL) {
@@ -727,6 +744,143 @@ void *mmap(void *addr, size_t length, int prot, int flags,
   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];
+	realpath(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];
+	realpath(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];
+	realpath(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];
+	realpath(fullpath,abspath);
+		
+	if(! __is_event_allowed("open",abspath,stage)) {
+	  __log_event("open",abspath,"DENIED",errno,stage);
+	    
+	  continue;
+	} else
+	  break;
+  }
+  
+  return ret;
+}
+
+
 int setenv(const char *name, const char *value, int overwrite) {
 	//printf ("   CHANGING name: %s, value: %s",name,value);
 	if(strcmp(name,"LD_PRELOAD")==0 ||