smbd: Streamline get_ea_names_from_file

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>

diff --git a/source3/smbd/trans2.c b/source3/smbd/trans2.c
index 6fe3f92f6bf309079542ccf5abb1f79709a80ccc..f58aacf4f344590f2ecb960740b33c5b951576e4 100644 (file)
--- a/source3/smbd/trans2.c
+++ b/source3/smbd/trans2.c
@@ -242,12 +242,14 @@ NTSTATUS get_ea_names_from_file(TALLOC_CTX *mem_ctx,
                                char ***pnames,
                                size_t *pnum_names)
 {
+       char smallbuf[1024];
        /* Get a list of all xattrs. Max namesize is 64k. */
        size_t ea_namelist_size = 1024;
-       char *ea_namelist = NULL;
+       char *ea_namelist = smallbuf;
+       char *to_free = NULL;
 
        char *p;
-       char **names, **tmp;
+       char **names;
        size_t num_names;
        ssize_t sizeret = -1;
        NTSTATUS status;
@@ -269,54 +271,45 @@ NTSTATUS get_ea_names_from_file(TALLOC_CTX *mem_ctx,
                return NT_STATUS_OK;
        }
 
-       /*
-        * TALLOC the result early to get the talloc hierarchy right.
-        */
-
-       names = talloc_array(mem_ctx, char *, 1);
-       if (names == NULL) {
-               DEBUG(0, ("talloc failed\n"));
-               return NT_STATUS_NO_MEMORY;
+       if (fsp && fsp->fh->fd != -1) {
+               sizeret = SMB_VFS_FLISTXATTR(fsp, ea_namelist,
+                                            ea_namelist_size);
+       } else {
+               sizeret = SMB_VFS_LISTXATTR(conn,
+                                           smb_fname->base_name,
+                                           ea_namelist,
+                                           ea_namelist_size);
        }
 
-       while (ea_namelist_size <= 65536) {
-
-               ea_namelist = talloc_realloc(
-                       names, ea_namelist, char, ea_namelist_size);
+       if ((sizeret == -1) && (errno == ERANGE)) {
+               ea_namelist_size = 65536;
+               ea_namelist = talloc_array(mem_ctx, char, ea_namelist_size);
                if (ea_namelist == NULL) {
-                       DEBUG(0, ("talloc failed\n"));
-                       TALLOC_FREE(names);
                        return NT_STATUS_NO_MEMORY;
                }
+               to_free = ea_namelist;
 
                if (fsp && fsp->fh->fd != -1) {
                        sizeret = SMB_VFS_FLISTXATTR(fsp, ea_namelist,
                                                     ea_namelist_size);
                } else {
                        sizeret = SMB_VFS_LISTXATTR(conn,
-                                       smb_fname->base_name,
-                                       ea_namelist,
-                                       ea_namelist_size);
-               }
-
-               if ((sizeret == -1) && (errno == ERANGE)) {
-                       ea_namelist_size *= 2;
-               }
-               else {
-                       break;
+                                                   smb_fname->base_name,
+                                                   ea_namelist,
+                                                   ea_namelist_size);
                }
        }
 
        if (sizeret == -1) {
-               TALLOC_FREE(names);
-               return map_nt_error_from_unix(errno);
+               status = map_nt_error_from_unix(errno);
+               TALLOC_FREE(to_free);
+               return status;
        }
 
-       DEBUG(10, ("%s: ea_namelist size = %u\n",
-                  __func__, (unsigned int)sizeret));
+       DBG_DEBUG("ea_namelist size = %zd\n", sizeret);
 
        if (sizeret == 0) {
-               TALLOC_FREE(names);
+               TALLOC_FREE(to_free);
                return NT_STATUS_OK;
        }
 
@@ -325,7 +318,7 @@ NTSTATUS get_ea_names_from_file(TALLOC_CTX *mem_ctx,
         */
 
        if (ea_namelist[sizeret-1] != '\0') {
-               TALLOC_FREE(names);
+               TALLOC_FREE(to_free);
                return NT_STATUS_INTERNAL_ERROR;
        }
 
@@ -338,26 +331,45 @@ NTSTATUS get_ea_names_from_file(TALLOC_CTX *mem_ctx,
                num_names += 1;
        }
 
-       tmp = talloc_realloc(mem_ctx, names, char *, num_names);
-       if (tmp == NULL) {
+       *pnum_names = num_names;
+
+       if (pnames == NULL) {
+               TALLOC_FREE(to_free);
+               return NT_STATUS_OK;
+       }
+
+       names = talloc_array(mem_ctx, char *, num_names);
+       if (names == NULL) {
                DEBUG(0, ("talloc failed\n"));
-               TALLOC_FREE(names);
+               TALLOC_FREE(to_free);
                return NT_STATUS_NO_MEMORY;
        }
 
-       names = tmp;
+       if (ea_namelist == smallbuf) {
+               ea_namelist = talloc_memdup(names, smallbuf, sizeret);
+               if (ea_namelist == NULL) {
+                       TALLOC_FREE(names);
+                       return NT_STATUS_NO_MEMORY;
+               }
+       } else {
+               talloc_steal(names, ea_namelist);
+
+               ea_namelist = talloc_realloc(names, ea_namelist, char,
+                                            sizeret);
+               if (ea_namelist == NULL) {
+                       TALLOC_FREE(names);
+                       return NT_STATUS_NO_MEMORY;
+               }
+       }
+
        num_names = 0;
 
        for (p = ea_namelist; p - ea_namelist < sizeret; p += strlen(p)+1) {
                names[num_names++] = p;
        }
 
-       if (pnames) {
-               *pnames = names;
-       } else {
-               TALLOC_FREE(names);
-       }
-       *pnum_names = num_names;
+       *pnames = names;
+
        return NT_STATUS_OK;
 }