s3: Add a new VFS op called SMB_VFS_TRANSLATE_NAME

This vop is designed to work in tandem with SMB_VFS_READDIR to allow
vfs modules to make modifications to arbitrary filenames before
they're consumed by callers.  Subsequently the core directory
enumeration code in smbd is now changed to free the memory that may be
allocated in a module.  This vop enables the new version of catia in
the following patch.

Signed-off-by: Tim Prouty <tprouty@samba.org>

1 files changed, 22 insertions, 13 deletions

diff --git a/source3/smbd/dir.c b/source3/smbd/dir.c
index 73c4cbb3e7..60fa0306b9 100644
--- a/source3/smbd/dir.c
+++ b/source3/smbd/dir.c
@@ -585,15 +585,16 @@ int dptr_dnum(struct dptr_struct *dptr)
  Return the next visible file name, skipping veto'd and invisible files.
 ****************************************************************************/
 
-static const char *dptr_normal_ReadDirName(struct dptr_struct *dptr,
+static char *dptr_normal_ReadDirName(struct dptr_struct *dptr,
 					   long *poffset, SMB_STRUCT_STAT *pst)
 {
 	/* Normal search for the next file. */
-	const char *name;
+	char *name;
 	while ((name = ReadDirName(dptr->dir_hnd, poffset, pst)) != NULL) {
 		if (is_visible_file(dptr->conn, dptr->path, name, pst, True)) {
 			return name;
 		}
+		TALLOC_FREE(name);
 	}
 	return NULL;
 }
@@ -612,14 +613,12 @@ char *dptr_ReadDirName(TALLOC_CTX *ctx,
 	char *pathreal = NULL;
 	char *found_name = NULL;
 	int ret;
-	const char *name_temp = NULL;
 	NTSTATUS status;
 
 	SET_STAT_INVALID(*pst);
 
 	if (dptr->has_wild || dptr->did_stat) {
-		name_temp = dptr_normal_ReadDirName(dptr, poffset, pst);
-		name = talloc_strdup(ctx, name_temp);
+		name = dptr_normal_ReadDirName(dptr, poffset, pst);
 		return name;
 	}
 
@@ -707,8 +706,8 @@ char *dptr_ReadDirName(TALLOC_CTX *ctx,
 
 	TALLOC_FREE(pathreal);
 
-	name_temp = dptr_normal_ReadDirName(dptr, poffset, pst);
-	name = talloc_strdup(ctx, name_temp);
+	name = dptr_normal_ReadDirName(dptr, poffset, pst);
+
 	return name;
 
 clean:
@@ -1337,10 +1336,10 @@ struct smb_Dir *OpenDir(TALLOC_CTX *mem_ctx, connection_struct *conn,
  Don't check for veto or invisible files.
 ********************************************************************/
 
-const char *ReadDirName(struct smb_Dir *dirp, long *poffset,
+char *ReadDirName(struct smb_Dir *dirp, long *poffset,
 			SMB_STRUCT_STAT *sbuf)
 {
-	const char *n;
+	char *n;
 	connection_struct *conn = dirp->conn;
 
 	/* Cheat to allow . and .. to be the first entries returned. */
@@ -1348,11 +1347,15 @@ const char *ReadDirName(struct smb_Dir *dirp, long *poffset,
 	     (*poffset == DOT_DOT_DIRECTORY_OFFSET)) && (dirp->file_number < 2))
 	{
 		if (dirp->file_number == 0) {
-			n = ".";
+			n = talloc_strdup(talloc_tos(), ".");
+			if (n == NULL)
+				return NULL;
 			*poffset = dirp->offset = START_OF_DIRECTORY_OFFSET;
 		} else {
 			*poffset = dirp->offset = DOT_DOT_DIRECTORY_OFFSET;
-			n = "..";
+			n = talloc_strdup(talloc_tos(), "..");
+			if (n == NULL)
+				return NULL;
 		}
 		dirp->file_number++;
 		return n;
@@ -1368,6 +1371,7 @@ const char *ReadDirName(struct smb_Dir *dirp, long *poffset,
 		/* Ignore . and .. - we've already returned them. */
 		if (*n == '.') {
 			if ((n[1] == '\0') || (n[1] == '.' && n[2] == '\0')) {
+				TALLOC_FREE(n);
 				continue;
 			}
 		}
@@ -1470,7 +1474,7 @@ void DirCacheAdd(struct smb_Dir *dirp, const char *name, long offset)
 bool SearchDir(struct smb_Dir *dirp, const char *name, long *poffset)
 {
 	int i;
-	const char *entry;
+	char *entry = NULL;
 	connection_struct *conn = dirp->conn;
 
 	/* Search back in the name cache. */
@@ -1499,8 +1503,10 @@ bool SearchDir(struct smb_Dir *dirp, const char *name, long *poffset)
 	*poffset = START_OF_DIRECTORY_OFFSET;
 	while ((entry = ReadDirName(dirp, poffset, NULL))) {
 		if (conn->case_sensitive ? (strcmp(entry, name) == 0) : strequal(entry, name)) {
+			TALLOC_FREE(entry);
 			return True;
 		}
+		TALLOC_FREE(entry);
 	}
 	return False;
 }
@@ -1514,7 +1520,7 @@ NTSTATUS can_delete_directory(struct connection_struct *conn,
 {
 	NTSTATUS status = NT_STATUS_OK;
 	long dirpos = 0;
-	const char *dname;
+	char *dname = NULL;
 	SMB_STRUCT_STAT st;
 	struct smb_Dir *dir_hnd = OpenDir(talloc_tos(), conn, dirname,
 					  NULL, 0);
@@ -1527,11 +1533,13 @@ NTSTATUS can_delete_directory(struct connection_struct *conn,
 		/* Quick check for "." and ".." */
 		if (dname[0] == '.') {
 			if (!dname[1] || (dname[1] == '.' && !dname[2])) {
+				TALLOC_FREE(dname);
 				continue;
 			}
 		}
 
 		if (!is_visible_file(conn, dirname, dname, &st, True)) {
+			TALLOC_FREE(dname);
 			continue;
 		}
 
@@ -1540,6 +1548,7 @@ NTSTATUS can_delete_directory(struct connection_struct *conn,
 		status = NT_STATUS_DIRECTORY_NOT_EMPTY;
 		break;
 	}
+	TALLOC_FREE(dname);
 	TALLOC_FREE(dir_hnd);
 
 	return status;