[PATCH 6.6 056/102] smb: client: negotiate compression algorithms

Greg Kroah-Hartman
2024-05-23T13:26:23Z

From: Enzo Matsumiya <ematsumiya@suse.de>

[ Upstream commit 8fe7062b7d11fcd21c4dcb5f530eaa1a099b24e7 ]

Change "compress=" mount option to a boolean flag, that, if set,
will enable negotiating compression algorithms with the server.

Do not de/compress anything for now.

Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/smb/client/cifs_debug.c | 32 ++++++++++++++++++++++++++------
fs/smb/client/cifsglob.h | 6 +++++-
fs/smb/client/connect.c | 2 +-
fs/smb/client/fs_context.c | 2 +-
fs/smb/client/fs_context.h | 2 +-
fs/smb/client/smb2pdu.c | 20 +++++++++++++++-----
6 files changed, 49 insertions(+), 15 deletions(-)

diff --git a/fs/smb/client/cifs_debug.c b/fs/smb/client/cifs_debug.c
index aa95fa95ca112..c71ae5c043060 100644
--- a/fs/smb/client/cifs_debug.c
+++ b/fs/smb/client/cifs_debug.c
@@ -280,6 +280,24 @@ static int cifs_debug_files_proc_show(struct seq_file *m, void *v)
return 0;
}

+static __always_inline const char *compression_alg_str(__le16 alg)
+{
+ switch (alg) {
+ case SMB3_COMPRESS_NONE:
+ return "NONE";
+ case SMB3_COMPRESS_LZNT1:
+ return "LZNT1";
+ case SMB3_COMPRESS_LZ77:
+ return "LZ77";
+ case SMB3_COMPRESS_LZ77_HUFF:
+ return "LZ77-Huffman";
+ case SMB3_COMPRESS_PATTERN:
+ return "Pattern_V1";
+ default:
+ return "invalid";
+ }
+}
+
static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
{
struct mid_q_entry *mid_entry;
@@ -425,12 +443,6 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
server->echo_credits,
server->oplock_credits,
server->dialect);
- if (server->compress_algorithm == SMB3_COMPRESS_LZNT1)
- seq_printf(m, " COMPRESS_LZNT1");
- else if (server->compress_algorithm == SMB3_COMPRESS_LZ77)
- seq_printf(m, " COMPRESS_LZ77");
- else if (server->compress_algorithm == SMB3_COMPRESS_LZ77_HUFF)
- seq_printf(m, " COMPRESS_LZ77_HUFF");
if (server->sign)
seq_printf(m, " signed");
if (server->posix_ext_supported)
@@ -462,6 +474,14 @@ static int cifs_debug_data_proc_show(struct seq_file *m, void *v)
server->leaf_fullpath);
}

+ seq_puts(m, "\nCompression: ");
+ if (!server->compression.requested)
+ seq_puts(m, "disabled on mount");
+ else if (server->compression.enabled)
+ seq_printf(m, "enabled (%s)", compression_alg_str(server->compression.alg));
+ else
+ seq_puts(m, "disabled (not supported by this server)");
+
seq_printf(m, "\n\n\tSessions: ");
i = 0;
list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index 053556ca6f011..70a12584375de 100644
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -772,7 +772,11 @@ struct TCP_Server_Info {
unsigned int max_write;
unsigned int min_offload;
unsigned int retrans;
- __le16 compress_algorithm;
+ struct {
+ bool requested; /* "compress" mount option set*/
+ bool enabled; /* actually negotiated with server */
+ __le16 alg; /* preferred alg negotiated with server */
+ } compression;
__u16 signing_algorithm;
__le16 cipher_type;
/* save initital negprot hash */
diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index deba1cfd11801..5acfd2057ca04 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -1748,7 +1748,7 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
tcp_ses->channel_sequence_num = 0; /* only tracked for primary channel */
tcp_ses->reconnect_instance = 1;
tcp_ses->lstrp = jiffies;
- tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
+ tcp_ses->compression.requested = ctx->compress;
spin_lock_init(&tcp_ses->req_lock);
spin_lock_init(&tcp_ses->srv_lock);
spin_lock_init(&tcp_ses->mid_lock);
diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c
index fbaa901d3493a..3bbac925d0766 100644
--- a/fs/smb/client/fs_context.c
+++ b/fs/smb/client/fs_context.c
@@ -978,7 +978,7 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,

switch (opt) {
case Opt_compress:
- ctx->compression = UNKNOWN_TYPE;
+ ctx->compress = true;
cifs_dbg(VFS,
"SMB3 compression support is experimental\n");
break;
diff --git a/fs/smb/client/fs_context.h b/fs/smb/client/fs_context.h
index e77ee81846b31..cf577ec0dd0ac 100644
--- a/fs/smb/client/fs_context.h
+++ b/fs/smb/client/fs_context.h
@@ -277,7 +277,7 @@ struct smb3_fs_context {
unsigned int max_credits; /* smb3 max_credits 10 < credits < 60000 */
unsigned int max_channels;
unsigned int max_cached_dirs;
- __u16 compression; /* compression algorithm 0xFFFF default 0=disabled */
+ bool compress; /* enable SMB2 messages (READ/WRITE) de/compression */
bool rootfs:1; /* if it's a SMB root file system */
bool witness:1; /* use witness protocol */
char *leaf_fullpath;
diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index 4d805933e14f3..86c647a947ccd 100644
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -743,7 +743,7 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
pneg_ctxt += sizeof(struct smb2_posix_neg_context);
neg_context_count++;

- if (server->compress_algorithm) {
+ if (server->compression.requested) {
build_compression_ctxt((struct smb2_compression_capabilities_context *)
pneg_ctxt);
ctxt_len = ALIGN(sizeof(struct smb2_compression_capabilities_context), 8);
@@ -791,6 +791,9 @@ static void decode_compress_ctx(struct TCP_Server_Info *server,
struct smb2_compression_capabilities_context *ctxt)
{
unsigned int len = le16_to_cpu(ctxt->DataLength);
+ __le16 alg;
+
+ server->compression.enabled = false;

/*
* Caller checked that DataLength remains within SMB boundary. We still
@@ -801,15 +804,22 @@ static void decode_compress_ctx(struct TCP_Server_Info *server,
pr_warn_once("server sent bad compression cntxt\n");
return;
}
+
if (le16_to_cpu(ctxt->CompressionAlgorithmCount) != 1) {
- pr_warn_once("Invalid SMB3 compress algorithm count\n");
+ pr_warn_once("invalid SMB3 compress algorithm count\n");
return;
}
- if (le16_to_cpu(ctxt->CompressionAlgorithms[0]) > 3) {
- pr_warn_once("unknown compression algorithm\n");
+
+ alg = ctxt->CompressionAlgorithms[0];
+
+ /* 'NONE' (0) compressor type is never negotiated */
+ if (alg == 0 || le16_to_cpu(alg) > 3) {
+ pr_warn_once("invalid compression algorithm '%u'\n", alg);
return;
}
- server->compress_algorithm = ctxt->CompressionAlgorithms[0];
+
+ server->compression.alg = alg;
+ server->compression.enabled = true;
}

static int decode_encrypt_ctx(struct TCP_Server_Info *server,
--
2.43.0