CIFS: Add capability to send SMB2 negotiate message

and add negotiate request type to let set_credits know that
we are only on negotiate stage and no need to make a decision
about disabling echos and oplocks.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 330 insertions, 0 deletions

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
new file mode 100644
index 0000000..719e4c4
--- /dev/null
+++ b/fs/cifs/smb2pdu.c
@@ -0,0 +1,330 @@
+/*
+ *   fs/cifs/smb2pdu.c
+ *
+ *   Copyright (C) International Business Machines  Corp., 2009, 2011
+ *                 Etersoft, 2012
+ *   Author(s): Steve French (sfrench@us.ibm.com)
+ *              Pavel Shilovsky (pshilovsky@samba.org) 2012
+ *
+ *   Contains the routines for constructing the SMB2 PDUs themselves
+ *
+ *   This library is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU Lesser General Public License as published
+ *   by the Free Software Foundation; either version 2.1 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This library is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
+ *   the GNU Lesser General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Lesser General Public License
+ *   along with this library; if not, write to the Free Software
+ *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+ /* SMB2 PDU handling routines here - except for leftovers (eg session setup) */
+ /* Note that there are handle based routines which must be		      */
+ /* treated slightly differently for reconnection purposes since we never     */
+ /* want to reuse a stale file handle and only the caller knows the file info */
+
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/vfs.h>
+#include <linux/uaccess.h>
+#include <linux/xattr.h>
+#include "smb2pdu.h"
+#include "cifsglob.h"
+#include "cifsacl.h"
+#include "cifsproto.h"
+#include "smb2proto.h"
+#include "cifs_unicode.h"
+#include "cifs_debug.h"
+#include "ntlmssp.h"
+#include "smb2status.h"
+
+/*
+ *  The following table defines the expected "StructureSize" of SMB2 requests
+ *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS requests.
+ *
+ *  Note that commands are defined in smb2pdu.h in le16 but the array below is
+ *  indexed by command in host byte order.
+ */
+static const int smb2_req_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
+	/* SMB2_NEGOTIATE */ 36,
+	/* SMB2_SESSION_SETUP */ 25,
+	/* SMB2_LOGOFF */ 4,
+	/* SMB2_TREE_CONNECT */	9,
+	/* SMB2_TREE_DISCONNECT */ 4,
+	/* SMB2_CREATE */ 57,
+	/* SMB2_CLOSE */ 24,
+	/* SMB2_FLUSH */ 24,
+	/* SMB2_READ */	49,
+	/* SMB2_WRITE */ 49,
+	/* SMB2_LOCK */	48,
+	/* SMB2_IOCTL */ 57,
+	/* SMB2_CANCEL */ 4,
+	/* SMB2_ECHO */ 4,
+	/* SMB2_QUERY_DIRECTORY */ 33,
+	/* SMB2_CHANGE_NOTIFY */ 32,
+	/* SMB2_QUERY_INFO */ 41,
+	/* SMB2_SET_INFO */ 33,
+	/* SMB2_OPLOCK_BREAK */ 24 /* BB this is 36 for LEASE_BREAK variant */
+};
+
+
+static void
+smb2_hdr_assemble(struct smb2_hdr *hdr, __le16 smb2_cmd /* command */ ,
+		  const struct cifs_tcon *tcon)
+{
+	struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
+	char *temp = (char *)hdr;
+	/* lookup word count ie StructureSize from table */
+	__u16 parmsize = smb2_req_struct_sizes[le16_to_cpu(smb2_cmd)];
+
+	/*
+	 * smaller than SMALL_BUFFER_SIZE but bigger than fixed area of
+	 * largest operations (Create)
+	 */
+	memset(temp, 0, 256);
+
+	/* Note this is only network field converted to big endian */
+	hdr->smb2_buf_length = cpu_to_be32(parmsize + sizeof(struct smb2_hdr)
+			- 4 /*  RFC 1001 length field itself not counted */);
+
+	hdr->ProtocolId[0] = 0xFE;
+	hdr->ProtocolId[1] = 'S';
+	hdr->ProtocolId[2] = 'M';
+	hdr->ProtocolId[3] = 'B';
+	hdr->StructureSize = cpu_to_le16(64);
+	hdr->Command = smb2_cmd;
+	hdr->CreditRequest = cpu_to_le16(2); /* BB make this dynamic */
+	hdr->ProcessId = cpu_to_le32((__u16)current->tgid);
+
+	if (!tcon)
+		goto out;
+
+	hdr->TreeId = tcon->tid;
+	/* Uid is not converted */
+	if (tcon->ses)
+		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; */
+	/* BB how does SMB2 do case sensitive? */
+	/* if (tcon->nocase)
+		hdr->Flags |= SMBFLG_CASELESS; */
+	/* if (tcon->ses && tcon->ses->server &&
+	    (tcon->ses->server->sec_mode & SECMODE_SIGN_REQUIRED))
+		hdr->Flags |= SMB2_FLAGS_SIGNED; */
+out:
+	pdu->StructureSize2 = cpu_to_le16(parmsize);
+	return;
+}
+
+static int
+smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
+{
+	int rc = 0;
+	/* BB add missing code here */
+	return rc;
+}
+
+/*
+ * Allocate and return pointer to an SMB request hdr, and set basic
+ * SMB information in the SMB header. If the return code is zero, this
+ * function must have filled in request_buf pointer.
+ */
+static int
+small_smb2_init(__le16 smb2_command, struct cifs_tcon *tcon,
+		void **request_buf)
+{
+	int rc = 0;
+
+	rc = smb2_reconnect(smb2_command, tcon);
+	if (rc)
+		return rc;
+
+	/* BB eventually switch this to SMB2 specific small buf size */
+	*request_buf = cifs_small_buf_get();
+	if (*request_buf == NULL) {
+		/* BB should we add a retry in here if not a writepage? */
+		return -ENOMEM;
+	}
+
+	smb2_hdr_assemble((struct smb2_hdr *) *request_buf, smb2_command, tcon);
+
+	if (tcon != NULL) {
+#ifdef CONFIG_CIFS_STATS2
+		/*
+		uint16_t com_code = le16_to_cpu(smb2_command);
+		cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_sent[com_code]);
+		*/
+#endif
+		cifs_stats_inc(&tcon->num_smbs_sent);
+	}
+
+	return rc;
+}
+
+static void
+free_rsp_buf(int resp_buftype, void *rsp)
+{
+	if (resp_buftype == CIFS_SMALL_BUFFER)
+		cifs_small_buf_release(rsp);
+	else if (resp_buftype == CIFS_LARGE_BUFFER)
+		cifs_buf_release(rsp);
+}
+
+#define SMB2_NUM_PROT 1
+
+#define SMB2_PROT   0
+#define SMB21_PROT  1
+#define BAD_PROT 0xFFFF
+
+#define SMB2_PROT_ID  0x0202
+#define SMB21_PROT_ID 0x0210
+#define BAD_PROT_ID   0xFFFF
+
+static struct {
+	int index;
+	__le16 name;
+} smb2protocols[] = {
+	{SMB2_PROT,  cpu_to_le16(SMB2_PROT_ID)},
+	{SMB21_PROT, cpu_to_le16(SMB21_PROT_ID)},
+	{BAD_PROT,   cpu_to_le16(BAD_PROT_ID)}
+};
+
+/*
+ *
+ *	SMB2 Worker functions follow:
+ *
+ *	The general structure of the worker functions is:
+ *	1) Call smb2_init (assembles SMB2 header)
+ *	2) Initialize SMB2 command specific fields in fixed length area of SMB
+ *	3) Call smb_sendrcv2 (sends request on socket and waits for response)
+ *	4) Decode SMB2 command specific fields in the fixed length area
+ *	5) Decode variable length data area (if any for this SMB2 command type)
+ *	6) Call free smb buffer
+ *	7) return
+ *
+ */
+
+int
+SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
+{
+	struct smb2_negotiate_req *req;
+	struct smb2_negotiate_rsp *rsp;
+	struct kvec iov[1];
+	int rc = 0;
+	int resp_buftype;
+	struct TCP_Server_Info *server;
+	unsigned int sec_flags;
+	u16 i;
+	u16 temp = 0;
+	int blob_offset, blob_length;
+	char *security_blob;
+	int flags = CIFS_NEG_OP;
+
+	cFYI(1, "Negotiate protocol");
+
+	if (ses->server)
+		server = ses->server;
+	else {
+		rc = -EIO;
+		return rc;
+	}
+
+	rc = small_smb2_init(SMB2_NEGOTIATE, NULL, (void **) &req);
+	if (rc)
+		return rc;
+
+	/* if any of auth flags (ie not sign or seal) are overriden use them */
+	if (ses->overrideSecFlg & (~(CIFSSEC_MUST_SIGN | CIFSSEC_MUST_SEAL)))
+		sec_flags = ses->overrideSecFlg;  /* BB FIXME fix sign flags?*/
+	else /* if override flags set only sign/seal OR them with global auth */
+		sec_flags = global_secflags | ses->overrideSecFlg;
+
+	cFYI(1, "sec_flags 0x%x", sec_flags);
+
+	req->hdr.SessionId = 0;
+
+	for (i = 0; i < SMB2_NUM_PROT; i++)
+		req->Dialects[i] = smb2protocols[i].name;
+
+	req->DialectCount = cpu_to_le16(i);
+	inc_rfc1001_len(req, i * 2);
+
+	/* only one of SMB2 signing flags may be set in SMB2 request */
+	if ((sec_flags & CIFSSEC_MUST_SIGN) == CIFSSEC_MUST_SIGN)
+		temp = SMB2_NEGOTIATE_SIGNING_REQUIRED;
+	else if (sec_flags & CIFSSEC_MAY_SIGN) /* MAY_SIGN is a single flag */
+		temp = SMB2_NEGOTIATE_SIGNING_ENABLED;
+
+	req->SecurityMode = cpu_to_le16(temp);
+
+	req->Capabilities = cpu_to_le32(SMB2_GLOBAL_CAP_DFS);
+
+	iov[0].iov_base = (char *)req;
+	/* 4 for rfc1002 length field */
+	iov[0].iov_len = get_rfc1002_length(req) + 4;
+
+	rc = SendReceive2(xid, ses, iov, 1, &resp_buftype, flags);
+
+	rsp = (struct smb2_negotiate_rsp *)iov[0].iov_base;
+	/*
+	 * No tcon so can't do
+	 * cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_fail[SMB2...]);
+	 */
+	if (rc != 0)
+		goto neg_exit;
+
+	if (rsp == NULL) {
+		rc = -EIO;
+		goto neg_exit;
+	}
+
+	cFYI(1, "mode 0x%x", rsp->SecurityMode);
+
+	if (rsp->DialectRevision == smb2protocols[SMB21_PROT].name)
+		cFYI(1, "negotiated smb2.1 dialect");
+	else if (rsp->DialectRevision == smb2protocols[SMB2_PROT].name)
+		cFYI(1, "negotiated smb2 dialect");
+	else {
+		cERROR(1, "Illegal dialect returned by server %d",
+			   le16_to_cpu(rsp->DialectRevision));
+		rc = -EIO;
+		goto neg_exit;
+	}
+	server->dialect = le16_to_cpu(rsp->DialectRevision);
+
+	server->maxBuf = le32_to_cpu(rsp->MaxTransactSize);
+	server->max_read = le32_to_cpu(rsp->MaxReadSize);
+	server->max_write = le32_to_cpu(rsp->MaxWriteSize);
+	/* BB Do we need to validate the SecurityMode? */
+	server->sec_mode = le16_to_cpu(rsp->SecurityMode);
+	server->capabilities = le32_to_cpu(rsp->Capabilities);
+
+	security_blob = smb2_get_data_area_len(&blob_offset, &blob_length,
+					       &rsp->hdr);
+	if (blob_length == 0) {
+		cERROR(1, "missing security blob on negprot");
+		rc = -EIO;
+		goto neg_exit;
+	}
+#ifdef CONFIG_SMB2_ASN1  /* BB REMOVEME when updated asn1.c ready */
+	rc = decode_neg_token_init(security_blob, blob_length,
+				   &server->sec_type);
+	if (rc == 1)
+		rc = 0;
+	else if (rc == 0) {
+		rc = -EIO;
+		goto neg_exit;
+	}
+#endif
+
+neg_exit:
+	free_rsp_buf(resp_buftype, rsp);
+	return rc;
+}