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smb3: add smb3.1.1 to default dialect list
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SMB3.1.1 dialect has additional security (among other) features
and should be requested when mounting to modern servers so it
can be used if the server supports it.

Add SMB3.1.1 to the default list of dialects requested.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
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Steve French committed Jan 3, 2019
1 parent 55a7f00 commit d5c7076
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Showing 2 changed files with 28 additions and 14 deletions.
40 changes: 27 additions & 13 deletions fs/cifs/smb2pdu.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -451,10 +451,6 @@ smb2_plain_req_init(__le16 smb2_command, struct cifs_tcon *tcon,
}


/* offset is sizeof smb2_negotiate_req but rounded up to 8 bytes */
#define OFFSET_OF_NEG_CONTEXT 0x68 /* sizeof(struct smb2_negotiate_req) */


#define SMB2_PREAUTH_INTEGRITY_CAPABILITIES cpu_to_le16(1)
#define SMB2_ENCRYPTION_CAPABILITIES cpu_to_le16(2)
#define SMB2_POSIX_EXTENSIONS_AVAILABLE cpu_to_le16(0x100)
Expand Down Expand Up @@ -491,10 +487,24 @@ static void
assemble_neg_contexts(struct smb2_negotiate_req *req,
unsigned int *total_len)
{
char *pneg_ctxt = (char *)req + OFFSET_OF_NEG_CONTEXT;
char *pneg_ctxt = (char *)req;
unsigned int ctxt_len;

*total_len += 2; /* Add 2 due to round to 8 byte boundary for 1st ctxt */
if (*total_len > 200) {
/* In case length corrupted don't want to overrun smb buffer */
cifs_dbg(VFS, "Bad frame length assembling neg contexts\n");
return;
}

/*
* round up total_len of fixed part of SMB3 negotiate request to 8
* byte boundary before adding negotiate contexts
*/
*total_len = roundup(*total_len, 8);

pneg_ctxt = (*total_len) + (char *)req;
req->NegotiateContextOffset = cpu_to_le32(*total_len);

build_preauth_ctxt((struct smb2_preauth_neg_context *)pneg_ctxt);
ctxt_len = DIV_ROUND_UP(sizeof(struct smb2_preauth_neg_context), 8) * 8;
*total_len += ctxt_len;
Expand All @@ -508,7 +518,6 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
*total_len += sizeof(struct smb2_posix_neg_context);

req->NegotiateContextOffset = cpu_to_le32(OFFSET_OF_NEG_CONTEXT);
req->NegotiateContextCount = cpu_to_le16(3);
}

Expand Down Expand Up @@ -724,8 +733,9 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
req->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
req->Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
req->Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
req->DialectCount = cpu_to_le16(3);
total_len += 6;
req->Dialects[3] = cpu_to_le16(SMB311_PROT_ID);
req->DialectCount = cpu_to_le16(4);
total_len += 8;
} else {
/* otherwise send specific dialect */
req->Dialects[0] = cpu_to_le16(ses->server->vals->protocol_id);
Expand All @@ -749,7 +759,9 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
else {
memcpy(req->ClientGUID, server->client_guid,
SMB2_CLIENT_GUID_SIZE);
if (ses->server->vals->protocol_id == SMB311_PROT_ID)
if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
(strcmp(ses->server->vals->version_string,
SMBDEFAULT_VERSION_STRING) == 0))
assemble_neg_contexts(req, &total_len);
}
iov[0].iov_base = (char *)req;
Expand Down Expand Up @@ -794,7 +806,8 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
} else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID)) {
/* ops set to 3.0 by default for default so update */
ses->server->ops = &smb21_operations;
}
} else if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID))
ses->server->ops = &smb311_operations;
} else if (le16_to_cpu(rsp->DialectRevision) !=
ses->server->vals->protocol_id) {
/* if requested single dialect ensure returned dialect matched */
Expand Down Expand Up @@ -941,13 +954,14 @@ int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon)
pneg_inbuf->DialectCount = cpu_to_le16(2);
/* structure is big enough for 3 dialects, sending only 2 */
inbuflen = sizeof(*pneg_inbuf) -
sizeof(pneg_inbuf->Dialects[0]);
(2 * sizeof(pneg_inbuf->Dialects[0]));
} else if (strcmp(tcon->ses->server->vals->version_string,
SMBDEFAULT_VERSION_STRING) == 0) {
pneg_inbuf->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
pneg_inbuf->Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
pneg_inbuf->Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
pneg_inbuf->DialectCount = cpu_to_le16(3);
pneg_inbuf->Dialects[3] = cpu_to_le16(SMB311_PROT_ID);
pneg_inbuf->DialectCount = cpu_to_le16(4);
/* structure is big enough for 3 dialects */
inbuflen = sizeof(*pneg_inbuf);
} else {
Expand Down
2 changes: 1 addition & 1 deletion fs/cifs/smb2pdu.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -898,7 +898,7 @@ struct validate_negotiate_info_req {
__u8 Guid[SMB2_CLIENT_GUID_SIZE];
__le16 SecurityMode;
__le16 DialectCount;
__le16 Dialects[3]; /* BB expand this if autonegotiate > 3 dialects */
__le16 Dialects[4]; /* BB expand this if autonegotiate > 4 dialects */
} __packed;

struct validate_negotiate_info_rsp {
Expand Down

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