smb: client: set correct file type from NFS reparse points

Handle all file types in NFS reparse points as specified in MS-FSCC
2.1.2.6 Network File System (NFS) Reparse Data Buffer.

The client is now able to set all file types based on the parsed NFS
reparse point, which used to support only symlinks.  This works for
SMB1+.

Before patch:

$ mount.cifs //srv/share /mnt -o ...
$ ls -l /mnt
ls: cannot access 'block': Operation not supported
ls: cannot access 'char': Operation not supported
ls: cannot access 'fifo': Operation not supported
ls: cannot access 'sock': Operation not supported
total 1
l????????? ? ?    ?    ?            ? block
l????????? ? ?    ?    ?            ? char
-rwxr-xr-x 1 root root 5 Nov 18 23:22 f0
l????????? ? ?    ?    ?            ? fifo
l--------- 1 root root 0 Nov 18 23:23 link -> f0
l????????? ? ?    ?    ?            ? sock

After patch:

$ mount.cifs //srv/share /mnt -o ...
$ ls -l /mnt
total 1
brwxr-xr-x 1 root root  123,  123 Nov 18 00:34 block
crwxr-xr-x 1 root root 1234, 1234 Nov 18 00:33 char
-rwxr-xr-x 1 root root          5 Nov 18 23:22 f0
prwxr-xr-x 1 root root          0 Nov 18 23:23 fifo
lrwxr-xr-x 1 root root          0 Nov 18 23:23 link -> f0
srwxr-xr-x 1 root root          0 Nov 19  2023 sock

Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 53 insertions, 48 deletions

diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index 2955eaa51d4d..f01a929a7a3a 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -2866,89 +2866,95 @@ 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)
+/* See MS-FSCC 2.1.2.6 for the 'NFS' style reparse tags */
+static int parse_reparse_posix(struct reparse_posix_data *buf,
+			       struct cifs_sb_info *cifs_sb,
+			       struct cifs_open_info_data *data)
 {
 	unsigned int len;
-
-	/* See MS-FSCC 2.1.2.6 for the 'NFS' style reparse tags */
-	len = le16_to_cpu(symlink_buf->ReparseDataLength);
-
-	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));
+	u64 type;
+
+	switch ((type = le64_to_cpu(buf->InodeType))) {
+	case NFS_SPECFILE_LNK:
+		len = le16_to_cpu(buf->ReparseDataLength);
+		data->symlink_target = cifs_strndup_from_utf16(buf->DataBuffer,
+							       len, true,
+							       cifs_sb->local_nls);
+		if (!data->symlink_target)
+			return -ENOMEM;
+		convert_delimiter(data->symlink_target, '/');
+		cifs_dbg(FYI, "%s: target path: %s\n",
+			 __func__, data->symlink_target);
+		break;
+	case NFS_SPECFILE_CHR:
+	case NFS_SPECFILE_BLK:
+	case NFS_SPECFILE_FIFO:
+	case NFS_SPECFILE_SOCK:
+		break;
+	default:
+		cifs_dbg(VFS, "%s: unhandled inode type: 0x%llx\n",
+			 __func__, type);
 		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 *sym,
-				 u32 plen, bool unicode, char **target_path,
-				 struct cifs_sb_info *cifs_sb)
+				 u32 plen, bool unicode,
+				 struct cifs_sb_info *cifs_sb,
+				 struct cifs_open_info_data *data)
 {
-	unsigned int sub_len;
-	unsigned int sub_offset;
+	unsigned int len;
+	unsigned int offs;
 
 	/* We handle Symbolic Link reparse tag here. See: MS-FSCC 2.1.2.4 */
 
-	sub_offset = le16_to_cpu(sym->SubstituteNameOffset);
-	sub_len = le16_to_cpu(sym->SubstituteNameLength);
-	if (sub_offset + 20 > plen ||
-	    sub_offset + sub_len + 20 > plen) {
+	offs = le16_to_cpu(sym->SubstituteNameOffset);
+	len = le16_to_cpu(sym->SubstituteNameLength);
+	if (offs + 20 > plen || offs + len + 20 > plen) {
 		cifs_dbg(VFS, "srv returned malformed symlink buffer\n");
 		return -EIO;
 	}
 
-	*target_path = cifs_strndup_from_utf16(sym->PathBuffer + sub_offset,
-					       sub_len, unicode,
-					       cifs_sb->local_nls);
-	if (!(*target_path))
+	data->symlink_target = cifs_strndup_from_utf16(sym->PathBuffer + offs,
+						       len, unicode,
+						       cifs_sb->local_nls);
+	if (!data->symlink_target)
 		return -ENOMEM;
 
-	convert_delimiter(*target_path, '/');
-	cifs_dbg(FYI, "%s: target path: %s\n", __func__, *target_path);
+	convert_delimiter(data->symlink_target, '/');
+	cifs_dbg(FYI, "%s: target path: %s\n", __func__, data->symlink_target);
 
 	return 0;
 }
 
 int parse_reparse_point(struct reparse_data_buffer *buf,
 			u32 plen, struct cifs_sb_info *cifs_sb,
-			bool unicode, char **target_path)
+			bool unicode, struct cifs_open_info_data *data)
 {
 	if (plen < sizeof(*buf)) {
-		cifs_dbg(VFS, "reparse buffer is too small. Must be at least 8 bytes but was %d\n",
-			 plen);
+		cifs_dbg(VFS, "%s: reparse buffer is too small. Must be at least 8 bytes but was %d\n",
+			 __func__, plen);
 		return -EIO;
 	}
 
 	if (plen < le16_to_cpu(buf->ReparseDataLength) + sizeof(*buf)) {
-		cifs_dbg(VFS, "srv returned invalid reparse buf length: %d\n",
-			 plen);
+		cifs_dbg(VFS, "%s: invalid reparse buf length: %d\n",
+			 __func__, plen);
 		return -EIO;
 	}
 
+	data->reparse.buf = buf;
+
 	/* See MS-FSCC 2.1.2 */
 	switch (le32_to_cpu(buf->ReparseTag)) {
 	case IO_REPARSE_TAG_NFS:
-		return parse_reparse_posix(
-			(struct reparse_posix_data *)buf,
-			plen, target_path, cifs_sb);
+		return parse_reparse_posix((struct reparse_posix_data *)buf,
+					   cifs_sb, data);
 	case IO_REPARSE_TAG_SYMLINK:
 		return parse_reparse_symlink(
 			(struct reparse_symlink_data_buffer *)buf,
-			plen, unicode, target_path, cifs_sb);
+			plen, unicode, cifs_sb, data);
 	case IO_REPARSE_TAG_LX_SYMLINK:
 	case IO_REPARSE_TAG_AF_UNIX:
 	case IO_REPARSE_TAG_LX_FIFO:
@@ -2956,8 +2962,8 @@ int parse_reparse_point(struct reparse_data_buffer *buf,
 	case IO_REPARSE_TAG_LX_BLK:
 		return 0;
 	default:
-		cifs_dbg(VFS, "srv returned unknown symlink buffer tag:0x%08x\n",
-			 le32_to_cpu(buf->ReparseTag));
+		cifs_dbg(VFS, "%s: unhandled reparse tag: 0x%08x\n",
+			 __func__, le32_to_cpu(buf->ReparseTag));
 		return -EOPNOTSUPP;
 	}
 }
@@ -2972,8 +2978,7 @@ static int smb2_parse_reparse_point(struct cifs_sb_info *cifs_sb,
 
 	buf = (struct reparse_data_buffer *)((u8 *)io +
 					     le32_to_cpu(io->OutputOffset));
-	return parse_reparse_point(buf, plen, cifs_sb,
-				   true, &data->symlink_target);
+	return parse_reparse_point(buf, plen, cifs_sb, true, data);
 }
 
 static int smb2_query_reparse_point(const unsigned int xid,