cifs: Remove the RFC1002 header from smb_hdr

Remove the RFC1002 header from struct smb_hdr as used for SMB-1.0.  This
simplifies the SMB-1.0 code by simplifying a lot of places that have to add
or subtract 4 to work around the fact that the RFC1002 header isn't really
part of the message and the base for various offsets within the message is
from the base of the smb_hdr, not the RFC1002 header.

Further, clean up a bunch of places that require an extra kvec struct
specifically pointing to the RFC1002 header, such that kvec[0].iov_base
must be exactly 4 bytes before kvec[1].iov_base.

This allows the header preamble size stuff to be removed too.

The size of the request and response message are then handed around either
directly or by summing the size of all the iov_len members in the kvec
array for which we have a count.

Also, this simplifies and cleans up the common transmission and receive
paths for SMB1 and SMB2/3 as there no longer needs to be special handling
casing for SMB1 messages as the RFC1002 header is now generated on the fly
for SMB1 as it is for SMB2/3.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Tom Talpey <tom@talpey.com>
Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
cc: Shyam Prasad N <sprasad@microsoft.com>
cc: linux-cifs@vger.kernel.org
cc: netfs@lists.linux.dev
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: dhowells

fs/smb/client/cifs_debug.c

@@ -37,15 +37,15 @@ cifs_dump_mem(char *label, void *data, int length)
 		       data, length, true);
 }
 
-void cifs_dump_detail(void *buf, struct TCP_Server_Info *server)
+void cifs_dump_detail(void *buf, size_t buf_len, struct TCP_Server_Info *server)
 {
 #ifdef CONFIG_CIFS_DEBUG2
 	struct smb_hdr *smb = buf;
 
 	cifs_dbg(VFS, "Cmd: %d Err: 0x%x Flags: 0x%x Flgs2: 0x%x Mid: %d Pid: %d Wct: %d\n",
 		 smb->Command, smb->Status.CifsError, smb->Flags,
 		 smb->Flags2, smb->Mid, smb->Pid, smb->WordCount);
-	if (!server->ops->check_message(buf, server->total_read, server)) {
+	if (!server->ops->check_message(buf, buf_len, server->total_read, server)) {
 		cifs_dbg(VFS, "smb buf %p len %u\n", smb,
 			 server->ops->calc_smb_size(smb));
 	}
@@ -79,9 +79,9 @@ void cifs_dump_mids(struct TCP_Server_Info *server)
 		cifs_dbg(VFS, "IsMult: %d IsEnd: %d\n",
 			 mid_entry->multiRsp, mid_entry->multiEnd);
 		if (mid_entry->resp_buf) {
-			cifs_dump_detail(mid_entry->resp_buf, server);
-			cifs_dump_mem("existing buf: ",
-				mid_entry->resp_buf, 62);
+			cifs_dump_detail(mid_entry->resp_buf,
+					 mid_entry->response_pdu_len, server);
+			cifs_dump_mem("existing buf: ", mid_entry->resp_buf, 62);
 		}
 	}
 	spin_unlock(&server->mid_queue_lock);

fs/smb/client/cifs_debug.h

@@ -15,10 +15,10 @@
 #define pr_fmt(fmt) "CIFS: " fmt
 
 void cifs_dump_mem(char *label, void *data, int length);
-void cifs_dump_detail(void *buf, struct TCP_Server_Info *ptcp_info);
-void cifs_dump_mids(struct TCP_Server_Info *);
+void cifs_dump_detail(void *buf, size_t buf_len, struct TCP_Server_Info *server);
+void cifs_dump_mids(struct TCP_Server_Info *server);
 extern bool traceSMB;		/* flag which enables the function below */
-void dump_smb(void *, int);
+void dump_smb(void *buf, int smb_buf_length);
 #define CIFS_INFO	0x01
 #define CIFS_RC		0x02
 #define CIFS_TIMER	0x04

fs/smb/client/cifsencrypt.c

@@ -91,18 +91,7 @@ int __cifs_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
 	struct kvec *iov = rqst->rq_iov;
 	int n_vec = rqst->rq_nvec;
 
-	/* iov[0] is actual data and not the rfc1002 length for SMB2+ */
-	if (!is_smb1(server)) {
-		if (iov[0].iov_len <= 4)
-			return -EIO;
-		i = 0;
-	} else {
-		if (n_vec < 2 || iov[0].iov_len != 4)
-			return -EIO;
-		i = 1; /* skip rfc1002 length */
-	}
-
-	for (; i < n_vec; i++) {
+	for (i = 0; i < n_vec; i++) {
 		if (iov[i].iov_len == 0)
 			continue;
 		if (iov[i].iov_base == NULL) {
@@ -165,10 +154,6 @@ int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
 	char smb_signature[20];
 	struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
 
-	if (rqst->rq_iov[0].iov_len != 4 ||
-	    rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
-		return -EIO;
-
 	if ((cifs_pdu == NULL) || (server == NULL))
 		return -EINVAL;
 
@@ -211,17 +196,16 @@ int cifs_sign_smbv(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
 }
 
 /* must be called with server->srv_mutex held */
-int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
+int cifs_sign_smb(struct smb_hdr *cifs_pdu, unsigned int pdu_len,
+		  struct TCP_Server_Info *server,
 		  __u32 *pexpected_response_sequence_number)
 {
-	struct kvec iov[2];
+	struct kvec iov[1] = {
+		[0].iov_base = (char *)cifs_pdu,
+		[0].iov_len = pdu_len,
+	};
 
-	iov[0].iov_base = cifs_pdu;
-	iov[0].iov_len = 4;
-	iov[1].iov_base = (char *)cifs_pdu + 4;
-	iov[1].iov_len = be32_to_cpu(cifs_pdu->smb_buf_length);
-
-	return cifs_sign_smbv(iov, 2, server,
+	return cifs_sign_smbv(iov, ARRAY_SIZE(iov), server,
 			      pexpected_response_sequence_number);
 }
 
@@ -234,10 +218,6 @@ int cifs_verify_signature(struct smb_rqst *rqst,
 	char what_we_think_sig_should_be[20];
 	struct smb_hdr *cifs_pdu = (struct smb_hdr *)rqst->rq_iov[0].iov_base;
 
-	if (rqst->rq_iov[0].iov_len != 4 ||
-	    rqst->rq_iov[0].iov_base + 4 != rqst->rq_iov[1].iov_base)
-		return -EIO;
-
 	if (cifs_pdu == NULL || server == NULL)
 		return -EINVAL;
 

fs/smb/client/cifsglob.h

@@ -346,13 +346,14 @@ struct smb_version_operations {
 	/* map smb to linux error */
 	int (*map_error)(char *, bool);
 	/* find mid corresponding to the response message */
-	struct mid_q_entry * (*find_mid)(struct TCP_Server_Info *, char *);
-	void (*dump_detail)(void *buf, struct TCP_Server_Info *ptcp_info);
+	struct mid_q_entry *(*find_mid)(struct TCP_Server_Info *server, char *buf);
+	void (*dump_detail)(void *buf, size_t buf_len, struct TCP_Server_Info *ptcp_info);
 	void (*clear_stats)(struct cifs_tcon *);
 	void (*print_stats)(struct seq_file *m, struct cifs_tcon *);
 	void (*dump_share_caps)(struct seq_file *, struct cifs_tcon *);
 	/* verify the message */
-	int (*check_message)(char *, unsigned int, struct TCP_Server_Info *);
+	int (*check_message)(char *buf, unsigned int pdu_len, unsigned int len,
+			     struct TCP_Server_Info *server);
 	bool (*is_oplock_break)(char *, struct TCP_Server_Info *);
 	int (*handle_cancelled_mid)(struct mid_q_entry *, struct TCP_Server_Info *);
 	void (*downgrade_oplock)(struct TCP_Server_Info *server,
@@ -636,8 +637,7 @@ struct smb_version_operations {
 
 #define HEADER_SIZE(server) (server->vals->header_size)
 #define MAX_HEADER_SIZE(server) (server->vals->max_header_size)
-#define HEADER_PREAMBLE_SIZE(server) (server->vals->header_preamble_size)
-#define MID_HEADER_SIZE(server) (HEADER_SIZE(server) - 1 - HEADER_PREAMBLE_SIZE(server))
+#define MID_HEADER_SIZE(server) (HEADER_SIZE(server) - 1)
 
 /**
  * CIFS superblock mount flags (mnt_cifs_flags) to consider when
@@ -832,9 +832,9 @@ struct TCP_Server_Info {
 	char dns_dom[CIFS_MAX_DOMAINNAME_LEN + 1];
 };
 
-static inline bool is_smb1(struct TCP_Server_Info *server)
+static inline bool is_smb1(const struct TCP_Server_Info *server)
 {
-	return HEADER_PREAMBLE_SIZE(server) != 0;
+	return server->vals->protocol_id == SMB10_PROT_ID;
 }
 
 static inline void cifs_server_lock(struct TCP_Server_Info *server)
@@ -973,16 +973,16 @@ compare_mid(__u16 mid, const struct smb_hdr *smb)
  * of kvecs to handle the receive, though that should only need to be done
  * once.
  */
-#define CIFS_MAX_WSIZE ((1<<24) - 1 - sizeof(WRITE_REQ) + 4)
-#define CIFS_MAX_RSIZE ((1<<24) - sizeof(READ_RSP) + 4)
+#define CIFS_MAX_WSIZE ((1<<24) - 1 - sizeof(WRITE_REQ))
+#define CIFS_MAX_RSIZE ((1<<24) - sizeof(READ_RSP))
 
 /*
  * When the server doesn't allow large posix writes, only allow a rsize/wsize
  * of 2^17-1 minus the size of the call header. That allows for a read or
  * write up to the maximum size described by RFC1002.
  */
-#define CIFS_MAX_RFC1002_WSIZE ((1<<17) - 1 - sizeof(WRITE_REQ) + 4)
-#define CIFS_MAX_RFC1002_RSIZE ((1<<17) - 1 - sizeof(READ_RSP) + 4)
+#define CIFS_MAX_RFC1002_WSIZE ((1<<17) - 1 - sizeof(WRITE_REQ))
+#define CIFS_MAX_RFC1002_RSIZE ((1<<17) - 1 - sizeof(READ_RSP))
 
 /*
  * Windows only supports a max of 60kb reads and 65535 byte writes. Default to
@@ -1701,6 +1701,7 @@ struct mid_q_entry {
 	struct task_struct *creator;
 	void *resp_buf;		/* pointer to received SMB header */
 	unsigned int resp_buf_size;
+	u32 response_pdu_len;
 	int mid_state;	/* wish this were enum but can not pass to wait_event */
 	int mid_rc;		/* rc for MID_RC */
 	__le16 command;		/* smb command code */

fs/smb/client/cifspdu.h

@@ -90,7 +90,7 @@
 
 /* future chained NTCreateXReadX bigger, but for time being NTCreateX biggest */
 /* among the requests (NTCreateX response is bigger with wct of 34) */
-#define MAX_CIFS_HDR_SIZE 0x58 /* 4 len + 32 hdr + (2*24 wct) + 2 bct + 2 pad */
+#define MAX_CIFS_HDR_SIZE 0x54 /* 32 hdr + (2*24 wct) + 2 bct + 2 pad */
 #define CIFS_SMALL_PATH 120 /* allows for (448-88)/3 */
 
 /* internal cifs vfs structures */

fs/smb/client/cifsproto.h

@@ -111,18 +111,16 @@ extern int compound_send_recv(const unsigned int xid, struct cifs_ses *ses,
 			      const int flags, const int num_rqst,
 			      struct smb_rqst *rqst, int *resp_buf_type,
 			      struct kvec *resp_iov);
-extern int SendReceive(const unsigned int /* xid */ , struct cifs_ses *,
-			struct smb_hdr * /* input */ ,
-			struct smb_hdr * /* out */ ,
-			int * /* bytes returned */ , const int);
-extern int SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
-			    char *in_buf, int flags);
+int SendReceive(const unsigned int xid, struct cifs_ses *ses,
+		struct smb_hdr *in_buf, unsigned int in_len,
+		struct smb_hdr *out_buf, int *pbytes_returned, const int flags);
+int SendReceiveNoRsp(const unsigned int xid, struct cifs_ses *ses,
+		     char *in_buf, unsigned int in_len, int flags);
 int cifs_sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server);
-extern struct mid_q_entry *cifs_setup_request(struct cifs_ses *,
-				struct TCP_Server_Info *,
-				struct smb_rqst *);
-extern struct mid_q_entry *cifs_setup_async_request(struct TCP_Server_Info *,
-						struct smb_rqst *);
+struct mid_q_entry *cifs_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *ignored,
+				       struct smb_rqst *rqst);
+struct mid_q_entry *cifs_setup_async_request(struct TCP_Server_Info *server,
+					     struct smb_rqst *rqst);
 int __smb_send_rqst(struct TCP_Server_Info *server, int num_rqst,
 		    struct smb_rqst *rqst);
 extern int cifs_check_receive(struct mid_q_entry *mid,
@@ -146,11 +144,9 @@ extern int SendReceive2(const unsigned int /* xid */ , struct cifs_ses *,
 			struct kvec *, int /* nvec to send */,
 			int * /* type of buf returned */, const int flags,
 			struct kvec * /* resp vec */);
-extern int SendReceiveBlockingLock(const unsigned int xid,
-			struct cifs_tcon *ptcon,
-			struct smb_hdr *in_buf,
-			struct smb_hdr *out_buf,
-			int *bytes_returned);
+int SendReceiveBlockingLock(const unsigned int xid, struct cifs_tcon *tcon,
+			    struct smb_hdr *in_buf, unsigned int in_len,
+			    struct smb_hdr *out_buf, int *pbytes_returned);
 
 void smb2_query_server_interfaces(struct work_struct *work);
 void
@@ -161,7 +157,8 @@ cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 				      bool mark_smb_session);
 extern int cifs_reconnect(struct TCP_Server_Info *server,
 			  bool mark_smb_session);
-extern int checkSMB(char *buf, unsigned int len, struct TCP_Server_Info *srvr);
+int checkSMB(char *buf, unsigned int pdu_len, unsigned int len,
+	     struct TCP_Server_Info *srvr);
 extern bool is_valid_oplock_break(char *, struct TCP_Server_Info *);
 extern bool backup_cred(struct cifs_sb_info *);
 extern bool is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 eof,
@@ -188,9 +185,9 @@ extern int cifs_convert_address(struct sockaddr *dst, const char *src, int len);
 extern void cifs_set_port(struct sockaddr *addr, const unsigned short int port);
 extern int map_smb_to_linux_error(char *buf, bool logErr);
 extern int map_and_check_smb_error(struct mid_q_entry *mid, bool logErr);
-extern void header_assemble(struct smb_hdr *, char /* command */ ,
-			    const struct cifs_tcon *, int /* length of
-			    fixed section (word count) in two byte units */);
+unsigned int header_assemble(struct smb_hdr *buffer, char smb_command,
+			     const struct cifs_tcon *treeCon, int word_count
+			     /* length of fixed section word count in two byte units  */);
 extern int small_smb_init_no_tc(const int smb_cmd, const int wct,
 				struct cifs_ses *ses,
 				void **request_buf);
@@ -565,12 +562,14 @@ extern void tconInfoFree(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace)
 
 extern int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
 		   __u32 *pexpected_response_sequence_number);
-extern int cifs_sign_smbv(struct kvec *iov, int n_vec, struct TCP_Server_Info *,
-			  __u32 *);
-extern int cifs_sign_smb(struct smb_hdr *, struct TCP_Server_Info *, __u32 *);
-extern int cifs_verify_signature(struct smb_rqst *rqst,
-				 struct TCP_Server_Info *server,
-				__u32 expected_sequence_number);
+int cifs_sign_smbv(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
+		   __u32 *pexpected_response_sequence);
+int cifs_sign_smb(struct smb_hdr *cifs_pdu, unsigned int pdu_len,
+		  struct TCP_Server_Info *server,
+		  __u32 *pexpected_response_sequence_number);
+int cifs_verify_signature(struct smb_rqst *rqst,
+			  struct TCP_Server_Info *server,
+			  __u32 expected_sequence_number);
 extern int setup_ntlmv2_rsp(struct cifs_ses *, const struct nls_table *);
 extern void cifs_crypto_secmech_release(struct TCP_Server_Info *server);
 extern int calc_seckey(struct cifs_ses *);