| /* SPDX-License-Identifier: GPL-2.0-only */ |
| /* |
| * Copyright (C) 2024, SUSE LLC |
| * |
| * Authors: Enzo Matsumiya <ematsumiya@suse.de> |
| * |
| * This file implements I/O compression support for SMB2 messages (SMB 3.1.1 only). |
| * See compress/ for implementation details of each algorithm. |
| * |
| * References: |
| * MS-SMB2 "3.1.4.4 Compressing the Message" - for compression details |
| * MS-SMB2 "3.1.5.3 Decompressing the Chained Message" - for decompression details |
| * MS-XCA - for details of the supported algorithms |
| */ |
| #ifndef _SMB_COMPRESS_H |
| #define _SMB_COMPRESS_H |
| |
| #include <linux/uio.h> |
| #include <linux/kernel.h> |
| #include "../common/smb2pdu.h" |
| #include "cifsglob.h" |
| |
| /* sizeof(smb2_compression_hdr) - sizeof(OriginalPayloadSize) */ |
| #define SMB_COMPRESS_HDR_LEN 16 |
| /* sizeof(smb2_compression_payload_hdr) - sizeof(OriginalPayloadSize) */ |
| #define SMB_COMPRESS_PAYLOAD_HDR_LEN 8 |
| #define SMB_COMPRESS_MIN_LEN PAGE_SIZE |
| |
| #ifdef CONFIG_CIFS_COMPRESSION |
| typedef int (*compress_send_fn)(struct TCP_Server_Info *, int, struct smb_rqst *); |
| |
| |
| int smb_compress(struct TCP_Server_Info *server, struct smb_rqst *rq, compress_send_fn send_fn); |
| bool should_compress(const struct cifs_tcon *tcon, const struct smb_rqst *rq); |
| |
| /* |
| * smb_compress_alg_valid() - Validate a compression algorithm. |
| * @alg: Compression algorithm to check. |
| * @valid_none: Conditional check whether NONE algorithm should be |
| * considered valid or not. |
| * |
| * If @alg is SMB3_COMPRESS_NONE, this function returns @valid_none. |
| * |
| * Note that 'NONE' (0) compressor type is considered invalid in protocol |
| * negotiation, as it's never requested to/returned from the server. |
| * |
| * Return: true if @alg is valid/supported, false otherwise. |
| */ |
| static __always_inline int smb_compress_alg_valid(__le16 alg, bool valid_none) |
| { |
| if (alg == SMB3_COMPRESS_NONE) |
| return valid_none; |
| |
| if (alg == SMB3_COMPRESS_LZ77 || alg == SMB3_COMPRESS_PATTERN) |
| return true; |
| |
| return false; |
| } |
| #else /* !CONFIG_CIFS_COMPRESSION */ |
| static inline int smb_compress(void *unused1, void *unused2, void *unused3) |
| { |
| return -EOPNOTSUPP; |
| } |
| |
| static inline bool should_compress(void *unused1, void *unused2) |
| { |
| return false; |
| } |
| |
| static inline int smb_compress_alg_valid(__le16 unused1, bool unused2) |
| { |
| return -EOPNOTSUPP; |
| } |
| #endif /* !CONFIG_CIFS_COMPRESSION */ |
| #endif /* _SMB_COMPRESS_H */ |
