diff mbox

[v3,17/32] CIFS: Add tree connect/disconnect capability for SMB2

Message ID 1342166025-29377-18-git-send-email-pshilovsky@samba.org (mailing list archive)
State New, archived
Headers show

Commit Message

Pavel Shilovsky July 13, 2012, 7:53 a.m. UTC 
From: Pavel Shilovsky <piastry@etersoft.ru>

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
---
 fs/cifs/cifs_unicode.c |    1 -
 fs/cifs/cifs_unicode.h |    1 -
 fs/cifs/cifsglob.h     |   11 +++-
 fs/cifs/smb2ops.c      |    2 +
 fs/cifs/smb2pdu.c      |  159 +++++++++++++++++++++++++++++++++++++++++++++++-
 fs/cifs/smb2pdu.h      |   57 +++++++++++++++++
 fs/cifs/smb2proto.h    |    4 +
 7 files changed, 230 insertions(+), 5 deletions(-)

Comments

Jeff Layton Aug. 1, 2012, 7:22 p.m. UTC | #1 
On Fri, 13 Jul 2012 11:53:30 +0400
Pavel Shilovsky <pshilovsky@samba.org> wrote:

> From: Pavel Shilovsky <piastry@etersoft.ru>
> 
> Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
> ---
>  fs/cifs/cifs_unicode.c |    1 -
>  fs/cifs/cifs_unicode.h |    1 -
>  fs/cifs/cifsglob.h     |   11 +++-
>  fs/cifs/smb2ops.c      |    2 +
>  fs/cifs/smb2pdu.c      |  159 +++++++++++++++++++++++++++++++++++++++++++++++-
>  fs/cifs/smb2pdu.h      |   57 +++++++++++++++++
>  fs/cifs/smb2proto.h    |    4 +
>  7 files changed, 230 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/cifs/cifs_unicode.c b/fs/cifs/cifs_unicode.c
> index fbb9da9..97c1d42 100644
> --- a/fs/cifs/cifs_unicode.c
> +++ b/fs/cifs/cifs_unicode.c
> @@ -330,4 +330,3 @@ cifsConvertToUTF16(__le16 *target, const char *source, int srclen,
>  ctoUTF16_out:
>  	return i;
>  }
> -
> diff --git a/fs/cifs/cifs_unicode.h b/fs/cifs/cifs_unicode.h
> index a513a54..a44c6eb 100644
> --- a/fs/cifs/cifs_unicode.h
> +++ b/fs/cifs/cifs_unicode.h
> @@ -84,7 +84,6 @@ char *cifs_strndup_from_utf16(const char *src, const int maxlen,
>  			      const struct nls_table *codepage);
>  extern int cifsConvertToUTF16(__le16 *target, const char *source, int maxlen,
>  			      const struct nls_table *cp, int mapChars);
> -
>  #endif
>  
>  /*
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index 0d78bc4..ef4e0a0 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -528,7 +528,7 @@ struct cifs_tcon {
>  	char treeName[MAX_TREE_SIZE + 1]; /* UNC name of resource in ASCII */
>  	char *nativeFileSystem;
>  	char *password;		/* for share-level security */
> -	__u16 tid;		/* The 2 byte tree id */
> +	__u32 tid;		/* The 4 byte tree id */
>  	__u16 Flags;		/* optional support bits */
>  	enum statusEnum tidStatus;
>  #ifdef CONFIG_CIFS_STATS
> @@ -584,6 +584,15 @@ struct cifs_tcon {
>  	bool local_lease:1; /* check leases (only) on local system not remote */
>  	bool broken_posix_open; /* e.g. Samba server versions < 3.3.2, 3.2.9 */
>  	bool need_reconnect:1; /* connection reset, tid now invalid */
> +#ifdef CONFIG_CIFS_SMB2
> +	bool print:1;		/* set if connection to printer share */
> +	bool bad_network_name:1; /* set if ret status STATUS_BAD_NETWORK_NAME */

You probably ought to eliminate the length qualifiers on bools. IIRC
from playing with pahole, they end up making a bool larger than it
would otherwise be (at least on x86_64).

> +	__u32 capabilities;
> +	__u32 share_flags;
> +	__u32 maximal_access;
> +	__u32 vol_serial_number;
> +	__le64 vol_create_time;
> +#endif /* CONFIG_CIFS_SMB2 */
>  #ifdef CONFIG_CIFS_FSCACHE
>  	u64 resource_id;		/* server resource id */
>  	struct fscache_cookie *fscache;	/* cookie for share */
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index 0057861..0e33ca3 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -172,6 +172,8 @@ struct smb_version_operations smb21_operations = {
>  	.negotiate = smb2_negotiate,
>  	.sess_setup = SMB2_sess_setup,
>  	.logoff = SMB2_logoff,
> +	.tree_connect = SMB2_tcon,
> +	.tree_disconnect = SMB2_tdis,
>  };
>  
>  struct smb_version_values smb21_values = {
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index 2165f0d..1bf037e 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -110,8 +110,8 @@ smb2_hdr_assemble(struct smb2_hdr *hdr, __le16 smb2_cmd /* command */ ,
>  		hdr->SessionId = tcon->ses->Suid;
>  	/* BB check following DFS flags BB */
>  	/* BB do we have to add check for SHI1005_FLAGS_DFS_ROOT too? */
> -	/* if (tcon->share_flags & SHI1005_FLAGS_DFS)
> -		hdr->Flags |= SMB2_FLAGS_DFS_OPERATIONS; */
> +	if (tcon->share_flags & SHI1005_FLAGS_DFS)
> +		hdr->Flags |= SMB2_FLAGS_DFS_OPERATIONS;
>  	/* BB how does SMB2 do case sensitive? */
>  	/* if (tcon->nocase)
>  		hdr->Flags |= SMBFLG_CASELESS; */
> @@ -549,3 +549,158 @@ SMB2_logoff(const unsigned int xid, struct cifs_ses *ses)
>  	 */
>  	return rc;
>  }
> +
> +static inline void cifs_stats_fail_inc(struct cifs_tcon *tcon, uint16_t code)
> +{
> +	/* cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_fail[code]); */
> +}
> +
> +#define MAX_SHARENAME_LENGTH (255 /* server */ + 80 /* share */ + 1 /* NULL */)
> +
> +int
> +SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree,
> +	  struct cifs_tcon *tcon, const struct nls_table *cp)
> +{
> +	struct smb2_tree_connect_req *req;
> +	struct smb2_tree_connect_rsp *rsp = NULL;
> +	struct kvec iov[2];
> +	int rc = 0;
> +	int resp_buftype;
> +	int unc_path_len;
> +	struct TCP_Server_Info *server;
> +	__le16 *unc_path = NULL;
> +
> +	cFYI(1, "TCON");
> +
> +	if ((ses->server) && tree)
> +		server = ses->server;
> +	else
> +		return -EIO;
> +
> +	if (tcon && tcon->bad_network_name)
> +		return -ENOENT;
> +
> +	unc_path = kmalloc(MAX_SHARENAME_LENGTH * 2, GFP_KERNEL);
> +	if (unc_path == NULL)
> +		return -ENOMEM;
> +
> +	unc_path_len = cifs_strtoUTF16(unc_path, tree, strlen(tree), cp) + 1;
> +	unc_path_len *= 2;
> +	if (unc_path_len < 2) {
> +		kfree(unc_path);
> +		return -EINVAL;
> +	}
> +
> +	rc = small_smb2_init(SMB2_TREE_CONNECT, tcon, (void **) &req);
> +	if (rc) {
> +		kfree(unc_path);
> +		return rc;
> +	}
> +
> +	if (tcon == NULL) {
> +		/* since no tcon, smb2_init can not do this, so do here */
> +		req->hdr.SessionId = ses->Suid;
> +		/* if (ses->server->sec_mode & SECMODE_SIGN_REQUIRED)
> +			req->hdr.Flags |= SMB2_FLAGS_SIGNED; */
> +	}
> +
> +	iov[0].iov_base = (char *)req;
> +	/* 4 for rfc1002 length field and 1 for pad */
> +	iov[0].iov_len = get_rfc1002_length(req) + 4 - 1;
> +
> +	/* Testing shows that buffer offset must be at location of Buffer[0] */
> +	req->PathOffset = cpu_to_le16(sizeof(struct smb2_tree_connect_req)
> +			- 1 /* pad */ - 4 /* do not count rfc1001 len field */);

That /* pad */ comment looks incorrect. The smb2_tree_connect_req is defined as:

struct smb2_tree_connect_req {
        struct smb2_hdr hdr;
        __le16 StructureSize;   /* Must be 9 */
        __le16 Reserved;
        __le16 PathOffset;
        __le16 PathLength;
        __u8   Buffer[1];       /* variable length */
} __packed;

...so what you're really saying there is offsetof(req->Buffer[0]). What
you should probably do is redefine "Buffer" as a C99 flexible array
member:

	__u8	Buffer[];

...then you can get rid of all of that fiddly -1 junk with the "pad".

> +	req->PathLength = cpu_to_le16(unc_path_len - 2);
> +	iov[1].iov_base = unc_path;
> +	iov[1].iov_len = unc_path_len;
> +
> +	inc_rfc1001_len(req, unc_path_len - 1 /* pad */);
> +
> +	rc = SendReceive2(xid, ses, iov, 2, &resp_buftype, 0);
> +	rsp = (struct smb2_tree_connect_rsp *)iov[0].iov_base;
> +
> +	if (rc != 0) {
> +		if (tcon) {
> +			cifs_stats_fail_inc(tcon, SMB2_TREE_CONNECT_HE);
> +			tcon->need_reconnect = true;
> +		}
> +		goto tcon_error_exit;
> +	}
> +
> +	if (rsp == NULL) {
> +		rc = -EIO;
> +		goto tcon_exit;
> +	}
> +
> +	if (tcon == NULL) {
> +		ses->ipc_tid = rsp->hdr.TreeId;
> +		goto tcon_exit;
> +	}
> +
> +	if (rsp->ShareType & SMB2_SHARE_TYPE_DISK)
> +		cFYI(1, "connection to disk share");
> +	else if (rsp->ShareType & SMB2_SHARE_TYPE_PIPE) {
> +		tcon->ipc = true;
> +		cFYI(1, "connection to pipe share");
> +	} else if (rsp->ShareType & SMB2_SHARE_TYPE_PRINT) {
> +		tcon->print = true;
> +		cFYI(1, "connection to printer");
> +	} else {
> +		cERROR(1, "unknown share type %d", rsp->ShareType);
> +		rc = -EOPNOTSUPP;
> +		goto tcon_error_exit;
> +	}
> +
> +	tcon->share_flags = le32_to_cpu(rsp->ShareFlags);
> +	tcon->maximal_access = le32_to_cpu(rsp->MaximalAccess);
> +	tcon->tidStatus = CifsGood;
> +	tcon->need_reconnect = false;
> +	tcon->tid = rsp->hdr.TreeId;
> +	strncpy(tcon->treeName, tree, MAX_TREE_SIZE);
> +
> +	if ((rsp->Capabilities & SMB2_SHARE_CAP_DFS) &&
> +	    ((tcon->share_flags & SHI1005_FLAGS_DFS) == 0))
> +		cERROR(1, "DFS capability contradicts DFS flag");
> +
> +tcon_exit:
> +	free_rsp_buf(resp_buftype, rsp);
> +	kfree(unc_path);
> +	return rc;
> +
> +tcon_error_exit:
> +	if (rsp->hdr.Status == STATUS_BAD_NETWORK_NAME) {
> +		cERROR(1, "BAD_NETWORK_NAME: %s", tree);
> +		tcon->bad_network_name = true;
> +	}
> +	goto tcon_exit;
> +}
> +
> +int
> +SMB2_tdis(const unsigned int xid, struct cifs_tcon *tcon)
> +{
> +	struct smb2_tree_disconnect_req *req; /* response is trivial */
> +	int rc = 0;
> +	struct TCP_Server_Info *server;
> +	struct cifs_ses *ses = tcon->ses;
> +
> +	cFYI(1, "Tree Disconnect");
> +
> +	if (ses && (ses->server))
> +		server = ses->server;
> +	else
> +		return -EIO;
> +
> +	if ((tcon->need_reconnect) || (tcon->ses->need_reconnect))
> +		return 0;
> +
> +	rc = small_smb2_init(SMB2_TREE_DISCONNECT, tcon, (void **) &req);
> +	if (rc)
> +		return rc;
> +
> +	rc = SendReceiveNoRsp(xid, ses, (char *)&req->hdr, 0);
> +	if (rc)
> +		cifs_stats_fail_inc(tcon, SMB2_TREE_DISCONNECT_HE);
> +
> +	return rc;
> +}
> diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
> index 26af68b..aa77bf3 100644
> --- a/fs/cifs/smb2pdu.h
> +++ b/fs/cifs/smb2pdu.h
> @@ -224,4 +224,61 @@ struct smb2_logoff_rsp {
>  	__le16 Reserved;
>  } __packed;
>  
> +struct smb2_tree_connect_req {
> +	struct smb2_hdr hdr;
> +	__le16 StructureSize;	/* Must be 9 */
> +	__le16 Reserved;
> +	__le16 PathOffset;
> +	__le16 PathLength;
> +	__u8   Buffer[1];	/* variable length */
> +} __packed;
> +
> +struct smb2_tree_connect_rsp {
> +	struct smb2_hdr hdr;
> +	__le16 StructureSize;	/* Must be 16 */
> +	__u8   ShareType;  /* see below */
> +	__u8   Reserved;
> +	__le32 ShareFlags; /* see below */
> +	__le32 Capabilities; /* see below */
> +	__le32 MaximalAccess;
> +} __packed;
> +
> +/* Possible ShareType values */
> +#define SMB2_SHARE_TYPE_DISK	0x01
> +#define SMB2_SHARE_TYPE_PIPE	0x02
> +#define	SMB2_SHARE_TYPE_PRINT	0x03
> +
> +/*
> + * Possible ShareFlags - exactly one and only one of the first 4 caching flags
> + * must be set (any of the remaining, SHI1005, flags may be set individually
> + * or in combination.
> + */
> +#define SMB2_SHAREFLAG_MANUAL_CACHING			0x00000000
> +#define SMB2_SHAREFLAG_AUTO_CACHING			0x00000010
> +#define SMB2_SHAREFLAG_VDO_CACHING			0x00000020
> +#define SMB2_SHAREFLAG_NO_CACHING			0x00000030
> +#define SHI1005_FLAGS_DFS				0x00000001
> +#define SHI1005_FLAGS_DFS_ROOT				0x00000002
> +#define SHI1005_FLAGS_RESTRICT_EXCLUSIVE_OPENS		0x00000100
> +#define SHI1005_FLAGS_FORCE_SHARED_DELETE		0x00000200
> +#define SHI1005_FLAGS_ALLOW_NAMESPACE_CACHING		0x00000400
> +#define SHI1005_FLAGS_ACCESS_BASED_DIRECTORY_ENUM	0x00000800
> +#define SHI1005_FLAGS_FORCE_LEVELII_OPLOCK		0x00001000
> +#define SHI1005_FLAGS_ENABLE_HASH			0x00002000
> +
> +/* Possible share capabilities */
> +#define SMB2_SHARE_CAP_DFS	cpu_to_le32(0x00000008)
> +
> +struct smb2_tree_disconnect_req {
> +	struct smb2_hdr hdr;
> +	__le16 StructureSize;	/* Must be 4 */
> +	__le16 Reserved;
> +} __packed;
> +
> +struct smb2_tree_disconnect_rsp {
> +	struct smb2_hdr hdr;
> +	__le16 StructureSize;	/* Must be 4 */
> +	__le16 Reserved;
> +} __packed;
> +
>  #endif				/* _SMB2PDU_H */
> diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
> index 9364fbc..bc72993 100644
> --- a/fs/cifs/smb2proto.h
> +++ b/fs/cifs/smb2proto.h
> @@ -50,5 +50,9 @@ extern int SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses);
>  extern int SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses,
>  			   const struct nls_table *nls_cp);
>  extern int SMB2_logoff(const unsigned int xid, struct cifs_ses *ses);
> +extern int SMB2_tcon(const unsigned int xid, struct cifs_ses *ses,
> +		     const char *tree, struct cifs_tcon *tcon,
> +		     const struct nls_table *);
> +extern int SMB2_tdis(const unsigned int xid, struct cifs_tcon *tcon);
>  
>  #endif			/* _SMB2PROTO_H */
diff mbox

Patch

diff --git a/fs/cifs/cifs_unicode.c b/fs/cifs/cifs_unicode.c
index fbb9da9..97c1d42 100644
--- a/fs/cifs/cifs_unicode.c
+++ b/fs/cifs/cifs_unicode.c
@@ -330,4 +330,3 @@  cifsConvertToUTF16(__le16 *target, const char *source, int srclen,
 ctoUTF16_out:
 	return i;
 }
-
diff --git a/fs/cifs/cifs_unicode.h b/fs/cifs/cifs_unicode.h
index a513a54..a44c6eb 100644
--- a/fs/cifs/cifs_unicode.h
+++ b/fs/cifs/cifs_unicode.h
@@ -84,7 +84,6 @@  char *cifs_strndup_from_utf16(const char *src, const int maxlen,
 			      const struct nls_table *codepage);
 extern int cifsConvertToUTF16(__le16 *target, const char *source, int maxlen,
 			      const struct nls_table *cp, int mapChars);
-
 #endif
 
 /*
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 0d78bc4..ef4e0a0 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -528,7 +528,7 @@  struct cifs_tcon {
 	char treeName[MAX_TREE_SIZE + 1]; /* UNC name of resource in ASCII */
 	char *nativeFileSystem;
 	char *password;		/* for share-level security */
-	__u16 tid;		/* The 2 byte tree id */
+	__u32 tid;		/* The 4 byte tree id */
 	__u16 Flags;		/* optional support bits */
 	enum statusEnum tidStatus;
 #ifdef CONFIG_CIFS_STATS
@@ -584,6 +584,15 @@  struct cifs_tcon {
 	bool local_lease:1; /* check leases (only) on local system not remote */
 	bool broken_posix_open; /* e.g. Samba server versions < 3.3.2, 3.2.9 */
 	bool need_reconnect:1; /* connection reset, tid now invalid */
+#ifdef CONFIG_CIFS_SMB2
+	bool print:1;		/* set if connection to printer share */
+	bool bad_network_name:1; /* set if ret status STATUS_BAD_NETWORK_NAME */
+	__u32 capabilities;
+	__u32 share_flags;
+	__u32 maximal_access;
+	__u32 vol_serial_number;
+	__le64 vol_create_time;
+#endif /* CONFIG_CIFS_SMB2 */
 #ifdef CONFIG_CIFS_FSCACHE
 	u64 resource_id;		/* server resource id */
 	struct fscache_cookie *fscache;	/* cookie for share */
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 0057861..0e33ca3 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -172,6 +172,8 @@  struct smb_version_operations smb21_operations = {
 	.negotiate = smb2_negotiate,
 	.sess_setup = SMB2_sess_setup,
 	.logoff = SMB2_logoff,
+	.tree_connect = SMB2_tcon,
+	.tree_disconnect = SMB2_tdis,
 };
 
 struct smb_version_values smb21_values = {
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 2165f0d..1bf037e 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -110,8 +110,8 @@  smb2_hdr_assemble(struct smb2_hdr *hdr, __le16 smb2_cmd /* command */ ,
 		hdr->SessionId = tcon->ses->Suid;
 	/* BB check following DFS flags BB */
 	/* BB do we have to add check for SHI1005_FLAGS_DFS_ROOT too? */
-	/* if (tcon->share_flags & SHI1005_FLAGS_DFS)
-		hdr->Flags |= SMB2_FLAGS_DFS_OPERATIONS; */
+	if (tcon->share_flags & SHI1005_FLAGS_DFS)
+		hdr->Flags |= SMB2_FLAGS_DFS_OPERATIONS;
 	/* BB how does SMB2 do case sensitive? */
 	/* if (tcon->nocase)
 		hdr->Flags |= SMBFLG_CASELESS; */
@@ -549,3 +549,158 @@  SMB2_logoff(const unsigned int xid, struct cifs_ses *ses)
 	 */
 	return rc;
 }
+
+static inline void cifs_stats_fail_inc(struct cifs_tcon *tcon, uint16_t code)
+{
+	/* cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_fail[code]); */
+}
+
+#define MAX_SHARENAME_LENGTH (255 /* server */ + 80 /* share */ + 1 /* NULL */)
+
+int
+SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree,
+	  struct cifs_tcon *tcon, const struct nls_table *cp)
+{
+	struct smb2_tree_connect_req *req;
+	struct smb2_tree_connect_rsp *rsp = NULL;
+	struct kvec iov[2];
+	int rc = 0;
+	int resp_buftype;
+	int unc_path_len;
+	struct TCP_Server_Info *server;
+	__le16 *unc_path = NULL;
+
+	cFYI(1, "TCON");
+
+	if ((ses->server) && tree)
+		server = ses->server;
+	else
+		return -EIO;
+
+	if (tcon && tcon->bad_network_name)
+		return -ENOENT;
+
+	unc_path = kmalloc(MAX_SHARENAME_LENGTH * 2, GFP_KERNEL);
+	if (unc_path == NULL)
+		return -ENOMEM;
+
+	unc_path_len = cifs_strtoUTF16(unc_path, tree, strlen(tree), cp) + 1;
+	unc_path_len *= 2;
+	if (unc_path_len < 2) {
+		kfree(unc_path);
+		return -EINVAL;
+	}
+
+	rc = small_smb2_init(SMB2_TREE_CONNECT, tcon, (void **) &req);
+	if (rc) {
+		kfree(unc_path);
+		return rc;
+	}
+
+	if (tcon == NULL) {
+		/* since no tcon, smb2_init can not do this, so do here */
+		req->hdr.SessionId = ses->Suid;
+		/* if (ses->server->sec_mode & SECMODE_SIGN_REQUIRED)
+			req->hdr.Flags |= SMB2_FLAGS_SIGNED; */
+	}
+
+	iov[0].iov_base = (char *)req;
+	/* 4 for rfc1002 length field and 1 for pad */
+	iov[0].iov_len = get_rfc1002_length(req) + 4 - 1;
+
+	/* Testing shows that buffer offset must be at location of Buffer[0] */
+	req->PathOffset = cpu_to_le16(sizeof(struct smb2_tree_connect_req)
+			- 1 /* pad */ - 4 /* do not count rfc1001 len field */);
+	req->PathLength = cpu_to_le16(unc_path_len - 2);
+	iov[1].iov_base = unc_path;
+	iov[1].iov_len = unc_path_len;
+
+	inc_rfc1001_len(req, unc_path_len - 1 /* pad */);
+
+	rc = SendReceive2(xid, ses, iov, 2, &resp_buftype, 0);
+	rsp = (struct smb2_tree_connect_rsp *)iov[0].iov_base;
+
+	if (rc != 0) {
+		if (tcon) {
+			cifs_stats_fail_inc(tcon, SMB2_TREE_CONNECT_HE);
+			tcon->need_reconnect = true;
+		}
+		goto tcon_error_exit;
+	}
+
+	if (rsp == NULL) {
+		rc = -EIO;
+		goto tcon_exit;
+	}
+
+	if (tcon == NULL) {
+		ses->ipc_tid = rsp->hdr.TreeId;
+		goto tcon_exit;
+	}
+
+	if (rsp->ShareType & SMB2_SHARE_TYPE_DISK)
+		cFYI(1, "connection to disk share");
+	else if (rsp->ShareType & SMB2_SHARE_TYPE_PIPE) {
+		tcon->ipc = true;
+		cFYI(1, "connection to pipe share");
+	} else if (rsp->ShareType & SMB2_SHARE_TYPE_PRINT) {
+		tcon->print = true;
+		cFYI(1, "connection to printer");
+	} else {
+		cERROR(1, "unknown share type %d", rsp->ShareType);
+		rc = -EOPNOTSUPP;
+		goto tcon_error_exit;
+	}
+
+	tcon->share_flags = le32_to_cpu(rsp->ShareFlags);
+	tcon->maximal_access = le32_to_cpu(rsp->MaximalAccess);
+	tcon->tidStatus = CifsGood;
+	tcon->need_reconnect = false;
+	tcon->tid = rsp->hdr.TreeId;
+	strncpy(tcon->treeName, tree, MAX_TREE_SIZE);
+
+	if ((rsp->Capabilities & SMB2_SHARE_CAP_DFS) &&
+	    ((tcon->share_flags & SHI1005_FLAGS_DFS) == 0))
+		cERROR(1, "DFS capability contradicts DFS flag");
+
+tcon_exit:
+	free_rsp_buf(resp_buftype, rsp);
+	kfree(unc_path);
+	return rc;
+
+tcon_error_exit:
+	if (rsp->hdr.Status == STATUS_BAD_NETWORK_NAME) {
+		cERROR(1, "BAD_NETWORK_NAME: %s", tree);
+		tcon->bad_network_name = true;
+	}
+	goto tcon_exit;
+}
+
+int
+SMB2_tdis(const unsigned int xid, struct cifs_tcon *tcon)
+{
+	struct smb2_tree_disconnect_req *req; /* response is trivial */
+	int rc = 0;
+	struct TCP_Server_Info *server;
+	struct cifs_ses *ses = tcon->ses;
+
+	cFYI(1, "Tree Disconnect");
+
+	if (ses && (ses->server))
+		server = ses->server;
+	else
+		return -EIO;
+
+	if ((tcon->need_reconnect) || (tcon->ses->need_reconnect))
+		return 0;
+
+	rc = small_smb2_init(SMB2_TREE_DISCONNECT, tcon, (void **) &req);
+	if (rc)
+		return rc;
+
+	rc = SendReceiveNoRsp(xid, ses, (char *)&req->hdr, 0);
+	if (rc)
+		cifs_stats_fail_inc(tcon, SMB2_TREE_DISCONNECT_HE);
+
+	return rc;
+}
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 26af68b..aa77bf3 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -224,4 +224,61 @@  struct smb2_logoff_rsp {
 	__le16 Reserved;
 } __packed;
 
+struct smb2_tree_connect_req {
+	struct smb2_hdr hdr;
+	__le16 StructureSize;	/* Must be 9 */
+	__le16 Reserved;
+	__le16 PathOffset;
+	__le16 PathLength;
+	__u8   Buffer[1];	/* variable length */
+} __packed;
+
+struct smb2_tree_connect_rsp {
+	struct smb2_hdr hdr;
+	__le16 StructureSize;	/* Must be 16 */
+	__u8   ShareType;  /* see below */
+	__u8   Reserved;
+	__le32 ShareFlags; /* see below */
+	__le32 Capabilities; /* see below */
+	__le32 MaximalAccess;
+} __packed;
+
+/* Possible ShareType values */
+#define SMB2_SHARE_TYPE_DISK	0x01
+#define SMB2_SHARE_TYPE_PIPE	0x02
+#define	SMB2_SHARE_TYPE_PRINT	0x03
+
+/*
+ * Possible ShareFlags - exactly one and only one of the first 4 caching flags
+ * must be set (any of the remaining, SHI1005, flags may be set individually
+ * or in combination.
+ */
+#define SMB2_SHAREFLAG_MANUAL_CACHING			0x00000000
+#define SMB2_SHAREFLAG_AUTO_CACHING			0x00000010
+#define SMB2_SHAREFLAG_VDO_CACHING			0x00000020
+#define SMB2_SHAREFLAG_NO_CACHING			0x00000030
+#define SHI1005_FLAGS_DFS				0x00000001
+#define SHI1005_FLAGS_DFS_ROOT				0x00000002
+#define SHI1005_FLAGS_RESTRICT_EXCLUSIVE_OPENS		0x00000100
+#define SHI1005_FLAGS_FORCE_SHARED_DELETE		0x00000200
+#define SHI1005_FLAGS_ALLOW_NAMESPACE_CACHING		0x00000400
+#define SHI1005_FLAGS_ACCESS_BASED_DIRECTORY_ENUM	0x00000800
+#define SHI1005_FLAGS_FORCE_LEVELII_OPLOCK		0x00001000
+#define SHI1005_FLAGS_ENABLE_HASH			0x00002000
+
+/* Possible share capabilities */
+#define SMB2_SHARE_CAP_DFS	cpu_to_le32(0x00000008)
+
+struct smb2_tree_disconnect_req {
+	struct smb2_hdr hdr;
+	__le16 StructureSize;	/* Must be 4 */
+	__le16 Reserved;
+} __packed;
+
+struct smb2_tree_disconnect_rsp {
+	struct smb2_hdr hdr;
+	__le16 StructureSize;	/* Must be 4 */
+	__le16 Reserved;
+} __packed;
+
 #endif				/* _SMB2PDU_H */
diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
index 9364fbc..bc72993 100644
--- a/fs/cifs/smb2proto.h
+++ b/fs/cifs/smb2proto.h
@@ -50,5 +50,9 @@  extern int SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses);
 extern int SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses,
 			   const struct nls_table *nls_cp);
 extern int SMB2_logoff(const unsigned int xid, struct cifs_ses *ses);
+extern int SMB2_tcon(const unsigned int xid, struct cifs_ses *ses,
+		     const char *tree, struct cifs_tcon *tcon,
+		     const struct nls_table *);
+extern int SMB2_tdis(const unsigned int xid, struct cifs_tcon *tcon);
 
 #endif			/* _SMB2PROTO_H */