cifs: plumb smb2 POSIX dir enumeration

* add code to request POSIX info level
* parse dir entries and fill cifs_fattr to get correct inode data

since the POSIX payload is variable size the number of entries in a
FIND response needs to be computed differently.

Dirs and regular files are properly reported along with mode bits,
hardlink number, c/m/atime. No special files yet (see below).

Current experimental version of Samba with the extension unfortunately
has issues with wildcards and needs the following patch:

> --- i/source3/smbd/smb2_query_directory.c
> +++ w/source3/smbd/smb2_query_directory.c
> @@ -397,9 +397,7 @@ smbd_smb2_query_directory_send(TALLOC_CTX
> *mem_ctx,
> 		}
> 	}
>
> -       if (!state->smbreq->posix_pathnames) {
> 		wcard_has_wild = ms_has_wild(state->in_file_name);
> -       }
>
> 	/* Ensure we've canonicalized any search path if not a wildcard. */
> 	if (!wcard_has_wild) {
>

Also for special files despite reporting them as reparse point samba
doesn't set the reparse tag field. This patch will mark them as needing
re-evaluation but the re-evaluate code doesn't deal with it yet.

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 27 insertions, 7 deletions

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 08d6a130e512..7356017a0821 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -4398,7 +4398,8 @@ static int posix_info_extra_size(const void *beg, const void *end)
 }
 
 static unsigned int
-num_entries(char *bufstart, char *end_of_buf, char **lastentry, size_t size)
+num_entries(int infotype, char *bufstart, char *end_of_buf, char **lastentry,
+	    size_t size)
 {
 	int len;
 	unsigned int entrycount = 0;
@@ -4422,8 +4423,13 @@ num_entries(char *bufstart, char *end_of_buf, char **lastentry, size_t size)
 		entryptr = entryptr + next_offset;
 		dir_info = (FILE_DIRECTORY_INFO *)entryptr;
 
-		len = le32_to_cpu(dir_info->FileNameLength);
-		if (entryptr + len < entryptr ||
+		if (infotype == SMB_FIND_FILE_POSIX_INFO)
+			len = posix_info_extra_size(entryptr, end_of_buf);
+		else
+			len = le32_to_cpu(dir_info->FileNameLength);
+
+		if (len < 0 ||
+		    entryptr + len < entryptr ||
 		    entryptr + len > end_of_buf ||
 		    entryptr + len + size > end_of_buf) {
 			cifs_dbg(VFS, "directory entry name would overflow frame end of buf %p\n",
@@ -4473,6 +4479,9 @@ int SMB2_query_directory_init(const unsigned int xid,
 	case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 		req->FileInformationClass = FILEID_FULL_DIRECTORY_INFORMATION;
 		break;
+	case SMB_FIND_FILE_POSIX_INFO:
+		req->FileInformationClass = SMB_FIND_FILE_POSIX_INFO;
+		break;
 	default:
 		cifs_tcon_dbg(VFS, "info level %u isn't supported\n",
 			info_level);
@@ -4538,6 +4547,10 @@ smb2_parse_query_directory(struct cifs_tcon *tcon,
 	case SMB_FIND_FILE_ID_FULL_DIR_INFO:
 		info_buf_size = sizeof(SEARCH_ID_FULL_DIR_INFO) - 1;
 		break;
+	case SMB_FIND_FILE_POSIX_INFO:
+		/* note that posix payload are variable size */
+		info_buf_size = sizeof(struct smb2_posix_info);
+		break;
 	default:
 		cifs_tcon_dbg(VFS, "info level %u isn't supported\n",
 			 srch_inf->info_level);
@@ -4547,8 +4560,10 @@ smb2_parse_query_directory(struct cifs_tcon *tcon,
 	rc = smb2_validate_iov(le16_to_cpu(rsp->OutputBufferOffset),
 			       le32_to_cpu(rsp->OutputBufferLength), rsp_iov,
 			       info_buf_size);
-	if (rc)
+	if (rc) {
+		cifs_tcon_dbg(VFS, "bad info payload");
 		return rc;
+	}
 
 	srch_inf->unicode = true;
 
@@ -4562,9 +4577,14 @@ smb2_parse_query_directory(struct cifs_tcon *tcon,
 	srch_inf->srch_entries_start = srch_inf->last_entry =
 		(char *)rsp + le16_to_cpu(rsp->OutputBufferOffset);
 	end_of_smb = rsp_iov->iov_len + (char *)rsp;
-	srch_inf->entries_in_buffer =
-			num_entries(srch_inf->srch_entries_start, end_of_smb,
-				    &srch_inf->last_entry, info_buf_size);
+
+	srch_inf->entries_in_buffer = num_entries(
+		srch_inf->info_level,
+		srch_inf->srch_entries_start,
+		end_of_smb,
+		&srch_inf->last_entry,
+		info_buf_size);
+
 	srch_inf->index_of_last_entry += srch_inf->entries_in_buffer;
 	cifs_dbg(FYI, "num entries %d last_index %lld srch start %p srch end %p\n",
 		 srch_inf->entries_in_buffer, srch_inf->index_of_last_entry,