smb3: Allow query of symlinks stored as reparse points (d5ecebc4) · Commits · 戴 / test

fs/cifs/smb2ops.c

+54 −6

Original line number	Diff line number	Diff line
		@@ -2373,6 +2373,39 @@ smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses,
		return rc;
		}

		static int
		parse_reparse_posix(struct reparse_posix_data *symlink_buf,
		u32 plen, char **target_path,
		struct cifs_sb_info *cifs_sb)
		{
		unsigned int len;

		/* See MS-FSCC 2.1.2.6 for the 'NFS' style reparse tags */
		len = le16_to_cpu(symlink_buf->ReparseDataLength);

		if (len + sizeof(struct reparse_data_buffer) > plen) {
		cifs_dbg(VFS, "srv returned malformed symlink buffer\n");
		return -EINVAL;
		}

		if (le64_to_cpu(symlink_buf->InodeType) != NFS_SPECFILE_LNK) {
		cifs_dbg(VFS, "%lld not a supported symlink type\n",
		le64_to_cpu(symlink_buf->InodeType));
		return -EOPNOTSUPP;
		}

		*target_path = cifs_strndup_from_utf16(
		symlink_buf->PathBuffer,
		len, true, cifs_sb->local_nls);
		if (!(*target_path))
		return -ENOMEM;

		convert_delimiter(*target_path, '/');
		cifs_dbg(FYI, "%s: target path: %s\n", __func__, *target_path);

		return 0;
		}

		static int
		parse_reparse_symlink(struct reparse_symlink_data_buffer *symlink_buf,
		u32 plen, char **target_path,
		@@ -2381,11 +2414,7 @@ parse_reparse_symlink(struct reparse_symlink_data_buffer *symlink_buf,
		unsigned int sub_len;
		unsigned int sub_offset;

		/* We only handle Symbolic Link : MS-FSCC 2.1.2.4 */
		if (le32_to_cpu(symlink_buf->ReparseTag) != IO_REPARSE_TAG_SYMLINK) {
		cifs_dbg(VFS, "srv returned invalid symlink buffer\n");
		return -EIO;
		}
		/* We handle Symbolic Link reparse tag here. See: MS-FSCC 2.1.2.4 */

		sub_offset = le16_to_cpu(symlink_buf->SubstituteNameOffset);
		sub_len = le16_to_cpu(symlink_buf->SubstituteNameLength);
		@@ -2407,6 +2436,25 @@ parse_reparse_symlink(struct reparse_symlink_data_buffer *symlink_buf,
		return 0;
		}

		static int
		parse_reparse_point(struct reparse_symlink_data_buffer *buf,
		u32 plen, char **target_path,
		struct cifs_sb_info *cifs_sb)
		{
		/* See MS-FSCC 2.1.2 */
		if (le32_to_cpu(buf->ReparseTag) == IO_REPARSE_TAG_NFS)
		return parse_reparse_posix((struct reparse_posix_data *)buf,
		plen, target_path, cifs_sb);
		else if (le32_to_cpu(buf->ReparseTag) == IO_REPARSE_TAG_SYMLINK)
		return parse_reparse_symlink(buf, plen, target_path,
		cifs_sb);

		cifs_dbg(VFS, "srv returned invalid symlink buffer tag:%d\n",
		le32_to_cpu(buf->ReparseTag));

		return -EIO;
		}

		#define SMB2_SYMLINK_STRUCT_SIZE \
		(sizeof(struct smb2_err_rsp) - 1 + sizeof(struct smb2_symlink_err_rsp))

		@@ -2547,7 +2595,7 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
		goto querty_exit;
		}

		rc = parse_reparse_symlink(
		rc = parse_reparse_point(
		(struct reparse_symlink_data_buffer *)reparse_buf,
		plen, target_path, cifs_sb);
		goto querty_exit;

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