add become_root()/unbecome_root() calls. These should be used around

regions of the code that need root privilages but which normally don't
have them (ie. when processing most SMBs). These functions can
optionally save/restore the current working directory as well

updated several places in the code that previously used unbecome_user()
to achieve the same thing to now use become_root() and unbecome_root()

changed close_file() to take an additional argument which says whether
this is a normal SMBclose type call or a close that resulted from some
other action, such as the close of a connection. If it is a abnormal
close then don't use magic scripts or print files.

changed sys_utime() to ignore any attempt to set the modification time
to 0 or -1. We've had reports that files have had their time set to
0 so this should catch those.

9 files changed, 152 insertions, 74 deletions

diff --git a/source/include/proto.h b/source/include/proto.h
index ffa2f251cca..d7cbc4cc4c4 100644
--- a/source/include/proto.h
+++ b/source/include/proto.h
@@ -705,7 +705,7 @@ int fd_attempt_open(char *fname, int flags, int mode);
 void fd_attempt_reopen(char *fname, int mode, file_fd_struct *fd_ptr);
 int fd_attempt_close(file_fd_struct *fd_ptr);
 void sync_file(int fnum);
-void close_file(int fnum);
+void close_file(int fnum, int normal_close);
 BOOL check_file_sharing(int cnum,char *fname);
 void open_file_shared(int fnum,int cnum,char *fname,int share_mode,int ofun,
 		      int mode,int *Access,int *action);
@@ -847,6 +847,8 @@ BOOL become_guest(void);
 BOOL become_user(int cnum, uint16 vuid);
 BOOL unbecome_user(void );
 int smbrun(char *cmd,char *outfile,BOOL shared);
+void become_root(int save_dir) ;
+void unbecome_root(int restore_dir);
 
 /*The following definitions come from  username.c  */
 
diff --git a/source/lib/system.c b/source/lib/system.c
index df24691512f..b149ccb4b98 100644
--- a/source/lib/system.c
+++ b/source/lib/system.c
@@ -194,14 +194,23 @@ now for utime()
 ********************************************************************/
 int sys_utime(char *fname,struct utimbuf *times)
 {
-  return(utime(dos_to_unix(fname,False),times));
+	/* if the modtime is 0 or -1 then ignore the call and
+	   return success */
+	if (times->modtime == (time_t)0 || times->modtime == (time_t)-1)
+		return 0;
+
+	/* if the access time is 0 or -1 then set it to the modtime */
+	if (times->actime == (time_t)0 || times->actime == (time_t)-1)
+		times->actime = times->modtime;
+	
+	return(utime(dos_to_unix(fname,False),times));
 }
 
+
 /*********************************************************
 for rename across filesystems Patch from Warren Birnbaum 
 <warrenb@hpcvscdp.cv.hp.com>
 **********************************************************/
-
 static int
 copy_reg (const char *source, const char *dest)
 {
diff --git a/source/locking/locking.c b/source/locking/locking.c
index db4990a7263..461ad5aef0b 100644
--- a/source/locking/locking.c
+++ b/source/locking/locking.c
@@ -611,10 +611,12 @@ BOOL lock_share_entry(int cnum, uint32 dev, uint32 inode, share_lock_token *ptok
   if(!share_name(cnum, dev, inode, fname))
     return False;
 
+  /* we need to do this as root */
+  become_root(0);
+
   {
     int old_umask;
     BOOL gotlock = False;
-    unbecome_user();
     old_umask = umask(0);
 
     /*
@@ -675,31 +677,14 @@ BOOL lock_share_entry(int cnum, uint32 dev, uint32 inode, share_lock_token *ptok
         gotlock = True;
     } while(!gotlock);
 
-    /*
-     * We have to come here if any of the above calls fail
-     * as we don't want to return and leave ourselves running
-     * as root !
-     */
-
     umask(old_umask);
-    if(!become_user(cnum,Connections[cnum].vuid))
-    {
-      DEBUG(0,("lock_share_entry: Can't become connected user!\n"));
-      close(fd);
-      ret = False;
-    }
-
-    /* We need to change directory back to the connection root. */
-    if (ChDir(Connections[cnum].connectpath) != 0)
-    {
-      DEBUG(0,("lock_share_entry: Can't change directory to %s (%s)\n",
-              Connections[cnum].connectpath, strerror(errno)));
-      close(fd);
-      ret = False;  
-    }
   }
 
   *ptok = (share_lock_token)fd;
+
+  /* return to our previous privilage level */
+  unbecome_root(0);
+
   return ret;
 }
 
@@ -727,31 +712,21 @@ BOOL unlock_share_entry(int cnum, uint32 dev, uint32 inode, share_lock_token tok
 /*******************************************************************
 Force a share file to be deleted.
 ********************************************************************/
-
 static int delete_share_file( int cnum, char *fname )
 {
-  unbecome_user();
-  if(unlink(fname) != 0)
-  {
-    DEBUG(0,("delete_share_file: Can't delete share file %s (%s)\n",
-            fname, strerror(errno)));
-  }
-
-  DEBUG(5,("delete_share_file: Deleted share file %s\n", fname));
-
-  if(!become_user(cnum,Connections[cnum].vuid))
-  {
-    DEBUG(0,("delete_share_file: Can't become connected user!\n"));
-    return -1;
-  }
-  /* We need to change directory back to the connection root. */
-  if (ChDir(Connections[cnum].connectpath) != 0)
-  {
-    DEBUG(0,("delete_share_file: Can't change directory to %s (%s)\n",
-            Connections[cnum].connectpath, strerror(errno)));
-    return -1;  
-  }
-  return 0;
+	/* the share file could be owned by anyone, so do this as root */
+	become_root(0);
+
+	if(unlink(fname) != 0) {
+		DEBUG(0,("delete_share_file: Can't delete share file %s (%s)\n",
+			 fname, strerror(errno)));
+	} else {
+		DEBUG(5,("delete_share_file: Deleted share file %s\n", fname));
+	}
+
+	unbecome_root(0);
+	
+	return 0;
 }
 
 /*******************************************************************
diff --git a/source/smbd/ipc.c b/source/smbd/ipc.c
index a0a4ec8fc73..1d7ee375d3f 100644
--- a/source/smbd/ipc.c
+++ b/source/smbd/ipc.c
@@ -1601,13 +1601,14 @@ static BOOL api_PrintJobInfo(int cnum,uint16 vuid,char *param,char *data,
 	name[l] = 0;
 	
 	DEBUG(3,("Setting print name to %s\n",name));
+
+	become_root(1);
 	
 	for (i=0;i<MAX_OPEN_FILES;i++)
 	  if (Files[i].open && Files[i].print_file)
 	    {
 	      pstring wd;
 	      GetWd(wd);
-	      unbecome_user();
 	      
 	      if (!become_user(Files[i].cnum,vuid) || 
 		  !become_service(Files[i].cnum,True))
@@ -1617,6 +1618,8 @@ static BOOL api_PrintJobInfo(int cnum,uint16 vuid,char *param,char *data,
 		string_set(&Files[i].name,name);
 	      break;
 	    }
+
+	unbecome_root(1);
       }
     desc.errcode=NERR_Success;
   
diff --git a/source/smbd/pipes.c b/source/smbd/pipes.c
index feb8d91a5b0..2cc6eea506f 100644
--- a/source/smbd/pipes.c
+++ b/source/smbd/pipes.c
@@ -141,7 +141,7 @@ int reply_open_pipe_and_X(char *inbuf,char *outbuf,int length,int bufsize)
   }
 
   if (fstat(Files[fnum].fd_ptr->fd,&sbuf) != 0) {
-    close_file(fnum);
+    close_file(fnum, 0);
     return(ERROR(ERRDOS,ERRnoaccess));
   }
 
@@ -149,7 +149,7 @@ int reply_open_pipe_and_X(char *inbuf,char *outbuf,int length,int bufsize)
   fmode = dos_mode(cnum,fname,&sbuf);
   mtime = sbuf.st_mtime;
   if (fmode & aDIR) {
-    close_file(fnum);
+    close_file(fnum, 0);
     return(ERROR(ERRDOS,ERRnoaccess));
   }
 
diff --git a/source/smbd/reply.c b/source/smbd/reply.c
index 7925add45f3..ffa80aac870 100644
--- a/source/smbd/reply.c
+++ b/source/smbd/reply.c
@@ -1138,7 +1138,7 @@ int reply_open(char *inbuf,char *outbuf)
   }
 
   if (fstat(Files[fnum].fd_ptr->fd,&sbuf) != 0) {
-    close_file(fnum);
+    close_file(fnum, 0);
     return(ERROR(ERRDOS,ERRnoaccess));
   }
     
@@ -1148,7 +1148,7 @@ int reply_open(char *inbuf,char *outbuf)
 
   if (fmode & aDIR) {
     DEBUG(3,("attempt to open a directory %s\n",fname));
-    close_file(fnum);
+    close_file(fnum, 0);
     return(ERROR(ERRDOS,ERRnoaccess));
   }
   
@@ -1229,7 +1229,7 @@ int reply_open_and_X(char *inbuf,char *outbuf,int length,int bufsize)
   }
 
   if (fstat(Files[fnum].fd_ptr->fd,&sbuf) != 0) {
-    close_file(fnum);
+    close_file(fnum, 0);
     return(ERROR(ERRDOS,ERRnoaccess));
   }
 
@@ -1237,7 +1237,7 @@ int reply_open_and_X(char *inbuf,char *outbuf,int length,int bufsize)
   fmode = dos_mode(cnum,fname,&sbuf);
   mtime = sbuf.st_mtime;
   if (fmode & aDIR) {
-    close_file(fnum);
+    close_file(fnum, 0);
     return(ERROR(ERRDOS,ERRnoaccess));
   }
 
@@ -1277,7 +1277,7 @@ int reply_ulogoffX(char *inbuf,char *outbuf,int length,int bufsize)
     int i;
     for (i=0;i<MAX_OPEN_FILES;i++)
       if (Files[i].uid == vuser->uid && Files[i].open) {
-	close_file(i);
+	close_file(i, 0);
       }
   }
 
@@ -2190,7 +2190,7 @@ int reply_close(char *inbuf,char *outbuf)
   /* try and set the date */
   set_filetime(Files[fnum].name,mtime);
 
-  close_file(fnum);
+  close_file(fnum, 1);
 
   /* We have a cached error */
   if(eclass || err)
@@ -2237,7 +2237,7 @@ int reply_writeclose(char *inbuf,char *outbuf)
 
   set_filetime(Files[fnum].name,mtime);
   
-  close_file(fnum);
+  close_file(fnum, 1);
 
   DEBUG(3,("%s writeclose fnum=%d cnum=%d num=%d wrote=%d (numopen=%d)\n",
 	   timestring(),fnum,cnum,numtowrite,nwritten,
@@ -2468,7 +2468,7 @@ int reply_printclose(char *inbuf,char *outbuf)
   if (!CAN_PRINT(cnum))
     return(ERROR(ERRDOS,ERRnoaccess));
   
-  close_file(fnum);
+  close_file(fnum, 1);
   
   DEBUG(3,("%s printclose fd=%d fnum=%d cnum=%d\n",timestring(),Files[fnum].fd_ptr->fd,fnum,cnum));
   
@@ -3040,14 +3040,14 @@ static BOOL copy_file(char *src,char *dest1,int cnum,int ofun,
 
   fnum2 = find_free_file();
   if (fnum2<0) {
-    close_file(fnum1);
+    close_file(fnum1, 0);
     return(False);
   }
   open_file_shared(fnum2,cnum,dest,(DENY_NONE<<4)|1,
 		   ofun,st.st_mode,&Access,&action);
 
   if (!Files[fnum2].open) {
-    close_file(fnum1);
+    close_file(fnum1, 0);
     return(False);
   }
 
@@ -3058,8 +3058,8 @@ static BOOL copy_file(char *src,char *dest1,int cnum,int ofun,
   if (st.st_size)
     ret = transfer_file(Files[fnum1].fd_ptr->fd,Files[fnum2].fd_ptr->fd,st.st_size,NULL,0,0);
 
-  close_file(fnum1);
-  close_file(fnum2);
+  close_file(fnum1, 0);
+  close_file(fnum2, 0);
 
   return(ret == st.st_size);
 }
diff --git a/source/smbd/server.c b/source/smbd/server.c
index 8e1bc152ffd..3bfd5bbbf40 100644
--- a/source/smbd/server.c
+++ b/source/smbd/server.c
@@ -1348,8 +1348,13 @@ static void check_magic(int fnum,int cnum)
 
 /****************************************************************************
 close a file - possibly invalidating the read prediction
+
+If normal_close is 1 then this came from a normal SMBclose (or equivalent) 
+operation otherwise it came as the result of some other operation such as 
+the closing of the connection. In the latter case printing and
+magic scripts are not run
 ****************************************************************************/
-void close_file(int fnum)
+void close_file(int fnum, int normal_close)
 {
   files_struct *fs_p = &Files[fnum];
   int cnum = fs_p->cnum;
@@ -1386,11 +1391,12 @@ void close_file(int fnum)
     unlock_share_entry( cnum, dev, inode, token);
 
   /* NT uses smbclose to start a print - weird */
-  if (fs_p->print_file)
+  if (normal_close && fs_p->print_file)
     print_file(fnum);
 
   /* check for magic scripts */
-  check_magic(fnum,cnum);
+  if (normal_close)
+	  check_magic(fnum,cnum);
 
   DEBUG(2,("%s %s closed file %s (numopen=%d)\n",
 	   timestring(),Connections[cnum].user,fs_p->name,
@@ -1510,7 +1516,7 @@ static void truncate_unless_locked(int fnum, int cnum, share_lock_token token,
       if (*share_locked && lp_share_modes(SNUM(cnum)))
         unlock_share_entry( cnum, Files[fnum].fd_ptr->dev, 
                             Files[fnum].fd_ptr->inode, token);
-      close_file(fnum);   
+      close_file(fnum, 0);   
       /* Share mode no longer locked. */
       *share_locked = False;
       errno = EACCES;
@@ -3203,7 +3209,7 @@ static void close_open_files(int cnum)
   int i;
   for (i=0;i<MAX_OPEN_FILES;i++)
     if( Files[i].cnum == cnum && Files[i].open) {
-      close_file(i);
+      close_file(i, 0);
     }
 }
 
@@ -3216,6 +3222,10 @@ void close_cnum(int cnum, uint16 vuid)
 {
   DirCacheFlush(SNUM(cnum));
 
+  close_open_files(cnum);
+  dptr_closecnum(cnum);
+
+  /* after this we are running as root, so be careful! */
   unbecome_user();
 
   if (!OPEN_CNUM(cnum))
@@ -3236,9 +3246,6 @@ void close_cnum(int cnum, uint16 vuid)
   if (lp_status(SNUM(cnum)))
     yield_connection(cnum,"STATUS.",MAXSTATUS);
 
-  close_open_files(cnum);
-  dptr_closecnum(cnum);
-
   /* execute any "postexec = " line */
   if (*lp_postexec(SNUM(cnum)) && become_user(cnum,vuid))
     {
diff --git a/source/smbd/trans2.c b/source/smbd/trans2.c
index ecc8f5dbec7..f7351b99e5a 100644
--- a/source/smbd/trans2.c
+++ b/source/smbd/trans2.c
@@ -226,7 +226,7 @@ static int call_trans2open(char *inbuf, char *outbuf, int bufsize, int cnum,
   }
 
   if (fstat(Files[fnum].fd_ptr->fd,&sbuf) != 0) {
-    close_file(fnum);
+    close_file(fnum, 0);
     return(ERROR(ERRDOS,ERRnoaccess));
   }
     
@@ -235,7 +235,7 @@ static int call_trans2open(char *inbuf, char *outbuf, int bufsize, int cnum,
   mtime = sbuf.st_mtime;
   inode = sbuf.st_ino;
   if (fmode & aDIR) {
-    close_file(fnum);
+    close_file(fnum, 0);
     return(ERROR(ERRDOS,ERRnoaccess));
   }
 
diff --git a/source/smbd/uid.c b/source/smbd/uid.c
index cdc4e474c61..fe2cb5a652d 100644
--- a/source/smbd/uid.c
+++ b/source/smbd/uid.c
@@ -258,6 +258,8 @@ BOOL become_user(int cnum, uint16 vuid)
 	if (current_user.ngroups > 0)
 	  if (setgroups(current_user.ngroups,current_user.groups)<0)
 	    DEBUG(0,("setgroups call failed!\n"));
+      } else {
+	    current_user.ngroups = 0;  
       }
 #endif
 
@@ -318,7 +320,8 @@ BOOL unbecome_user(void )
 
   current_user.uid = initial_uid;
   current_user.gid = initial_gid;
-  
+  current_user.ngroups = 0;
+
   if (ChDir(OriginalDir) != 0)
     DEBUG(0,("%s chdir(%s) failed in unbecome_user\n",
 	     timestring(),OriginalDir));
@@ -476,3 +479,82 @@ int smbrun(char *cmd,char *outfile,BOOL shared)
 #endif
   return 1;
 }
+
+
+
+static struct current_user current_user_saved;
+static int become_root_depth;
+static pstring become_root_dir;
+
+/****************************************************************************
+This is used when we need to do a privilaged operation (such as mucking
+with share mode files) and temporarily need root access to do it. This
+call should always be paired with an unbecome_root() call immediately
+after the operation
+
+Set save_dir if you also need to save/restore the CWD 
+****************************************************************************/
+void become_root(int save_dir) 
+{
+	if (become_root_depth) {
+		DEBUG(0,("ERROR: become root depth is non zero\n"));
+	}
+	if (save_dir)
+		GetWd(become_root_dir);
+
+	current_user_saved = current_user;
+	become_root_depth = 1;
+
+	become_gid(0);
+	become_uid(0);
+}
+
+/****************************************************************************
+When the privilaged operation is over call this
+
+Set save_dir if you also need to save/restore the CWD 
+****************************************************************************/
+void unbecome_root(int restore_dir)
+{
+	if (become_root_depth != 1) {
+		DEBUG(0,("ERROR: unbecome root depth is %d\n",
+			 become_root_depth));
+	}
+
+	/* we might have done a become_user() while running as root,
+	   if we have then become root again in order to become 
+	   non root! */
+	if (current_user.uid != 0) {
+		become_uid(0);
+	}
+
+	/* restore our gid first */
+	if (!become_gid(current_user_saved.gid)) {
+		DEBUG(0,("ERROR: Failed to restore gid\n"));
+		exit_server("Failed to restore gid");
+	}
+
+#ifndef NO_SETGROUPS      
+	if (current_user_saved.ngroups > 0) {
+		if (setgroups(current_user_saved.ngroups,
+			      current_user_saved.groups)<0)
+			DEBUG(0,("ERROR: setgroups call failed!\n"));
+	}
+#endif
+
+	/* now restore our uid */
+	if (!become_uid(current_user_saved.uid)) {
+		DEBUG(0,("ERROR: Failed to restore uid\n"));
+		exit_server("Failed to restore uid");
+	}
+
+	if (restore_dir)
+		ChDir(become_root_dir);
+
+	current_user = current_user_saved;
+
+	become_root_depth = 0;
+}
+
+
+