CIFS: Add session setup/logoff capability for SMB2

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

1 files changed, 221 insertions, 0 deletions

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 719e4c4f0307..2165f0d15963 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -328,3 +328,224 @@ neg_exit:
         free_rsp_buf(resp_buftype, rsp);
         return rc;
 }
+
+int
+SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses,
+                const struct nls_table *nls_cp)
+{
+        struct smb2_sess_setup_req *req;
+        struct smb2_sess_setup_rsp *rsp = NULL;
+        struct kvec iov[2];
+        int rc = 0;
+        int resp_buftype;
+        __le32 phase = NtLmNegotiate; /* NTLMSSP, if needed, is multistage */
+        struct TCP_Server_Info *server;
+        unsigned int sec_flags;
+        u8 temp = 0;
+        u16 blob_length = 0;
+        char *security_blob;
+        char *ntlmssp_blob = NULL;
+        bool use_spnego = false; /* else use raw ntlmssp */
+
+        cFYI(1, "Session Setup");
+
+        if (ses->server)
+                server = ses->server;
+        else {
+                rc = -EIO;
+                return rc;
+        }
+
+        /*
+         * If memory allocation is successful, caller of this function
+         * frees it.
+         */
+        ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
+        if (!ses->ntlmssp)
+                return -ENOMEM;
+
+        ses->server->secType = RawNTLMSSP;
+
+ssetup_ntlmssp_authenticate:
+        if (phase == NtLmChallenge)
+                phase = NtLmAuthenticate; /* if ntlmssp, now final phase */
+
+        rc = small_smb2_init(SMB2_SESSION_SETUP, 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; /* First session, not a reauthenticate */
+        req->VcNumber = 0; /* MBZ */
+        /* to enable echos and oplocks */
+        req->hdr.CreditRequest = cpu_to_le16(3);
+
+        /* 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 (ses->server->sec_mode & SMB2_NEGOTIATE_SIGNING_REQUIRED)
+                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 = temp;
+        req->Capabilities = 0;
+        req->Channel = 0; /* MBZ */
+
+        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;
+        if (phase == NtLmNegotiate) {
+                ntlmssp_blob = kmalloc(sizeof(struct _NEGOTIATE_MESSAGE),
+                                       GFP_KERNEL);
+                if (ntlmssp_blob == NULL) {
+                        rc = -ENOMEM;
+                        goto ssetup_exit;
+                }
+                build_ntlmssp_negotiate_blob(ntlmssp_blob, ses);
+                if (use_spnego) {
+                        /* blob_length = build_spnego_ntlmssp_blob(
+                                        &security_blob,
+                                        sizeof(struct _NEGOTIATE_MESSAGE),
+                                        ntlmssp_blob); */
+                        /* BB eventually need to add this */
+                        cERROR(1, "spnego not supported for SMB2 yet");
+                        rc = -EOPNOTSUPP;
+                        kfree(ntlmssp_blob);
+                        goto ssetup_exit;
+                } else {
+                        blob_length = sizeof(struct _NEGOTIATE_MESSAGE);
+                        /* with raw NTLMSSP we don't encapsulate in SPNEGO */
+                        security_blob = ntlmssp_blob;
+                }
+        } else if (phase == NtLmAuthenticate) {
+                req->hdr.SessionId = ses->Suid;
+                ntlmssp_blob = kzalloc(sizeof(struct _NEGOTIATE_MESSAGE) + 500,
+                                       GFP_KERNEL);
+                if (ntlmssp_blob == NULL) {
+                        cERROR(1, "failed to malloc ntlmssp blob");
+                        rc = -ENOMEM;
+                        goto ssetup_exit;
+                }
+                rc = build_ntlmssp_auth_blob(ntlmssp_blob, &blob_length, ses,
+                                             nls_cp);
+                if (rc) {
+                        cFYI(1, "build_ntlmssp_auth_blob failed %d", rc);
+                        goto ssetup_exit; /* BB double check error handling */
+                }
+                if (use_spnego) {
+                        /* blob_length = build_spnego_ntlmssp_blob(
+                                                        &security_blob,
+                                                        blob_length,
+                                                        ntlmssp_blob); */
+                        cERROR(1, "spnego not supported for SMB2 yet");
+                        rc = -EOPNOTSUPP;
+                        kfree(ntlmssp_blob);
+                        goto ssetup_exit;
+                } else {
+                        security_blob = ntlmssp_blob;
+                }
+        } else {
+                cERROR(1, "illegal ntlmssp phase");
+                rc = -EIO;
+                goto ssetup_exit;
+        }
+
+        /* Testing shows that buffer offset must be at location of Buffer[0] */
+        req->SecurityBufferOffset =
+                                cpu_to_le16(sizeof(struct smb2_sess_setup_req) -
+                                            1 /* pad */ - 4 /* rfc1001 len */);
+        req->SecurityBufferLength = cpu_to_le16(blob_length);
+        iov[1].iov_base = security_blob;
+        iov[1].iov_len = blob_length;
+
+        inc_rfc1001_len(req, blob_length - 1 /* pad */);
+
+        /* BB add code to build os and lm fields */
+
+        rc = SendReceive2(xid, ses, iov, 2, &resp_buftype, CIFS_LOG_ERROR);
+
+        kfree(security_blob);
+        rsp = (struct smb2_sess_setup_rsp *)iov[0].iov_base;
+        if (rsp->hdr.Status == STATUS_MORE_PROCESSING_REQUIRED) {
+                if (phase != NtLmNegotiate) {
+                        cERROR(1, "Unexpected more processing error");
+                        goto ssetup_exit;
+                }
+                if (offsetof(struct smb2_sess_setup_rsp, Buffer) - 4 !=
+                        le16_to_cpu(rsp->SecurityBufferOffset)) {
+                        cERROR(1, "Invalid security buffer offset %d",
+                                  le16_to_cpu(rsp->SecurityBufferOffset));
+                        rc = -EIO;
+                        goto ssetup_exit;
+                }
+
+                /* NTLMSSP Negotiate sent now processing challenge (response) */
+                phase = NtLmChallenge; /* process ntlmssp challenge */
+                rc = 0; /* MORE_PROCESSING is not an error here but expected */
+                ses->Suid = rsp->hdr.SessionId;
+                rc = decode_ntlmssp_challenge(rsp->Buffer,
+                                le16_to_cpu(rsp->SecurityBufferLength), ses);
+        }
+
+        /*
+         * BB eventually add code for SPNEGO decoding of NtlmChallenge blob,
+         * but at least the raw NTLMSSP case works.
+         */
+        /*
+         * No tcon so can't do
+         * cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_fail[SMB2...]);
+         */
+        if (rc != 0)
+                goto ssetup_exit;
+
+        if (rsp == NULL) {
+                rc = -EIO;
+                goto ssetup_exit;
+        }
+
+        ses->session_flags = le16_to_cpu(rsp->SessionFlags);
+ssetup_exit:
+        free_rsp_buf(resp_buftype, rsp);
+
+        /* if ntlmssp, and negotiate succeeded, proceed to authenticate phase */
+        if ((phase == NtLmChallenge) && (rc == 0))
+                goto ssetup_ntlmssp_authenticate;
+        return rc;
+}
+
+int
+SMB2_logoff(const unsigned int xid, struct cifs_ses *ses)
+{
+        struct smb2_logoff_req *req; /* response is also trivial struct */
+        int rc = 0;
+        struct TCP_Server_Info *server;
+
+        cFYI(1, "disconnect session %p", ses);
+
+        if (ses && (ses->server))
+                server = ses->server;
+        else
+                return -EIO;
+
+        rc = small_smb2_init(SMB2_LOGOFF, NULL, (void **) &req);
+        if (rc)
+                return rc;
+
+         /* since no tcon, smb2_init can not do this, so do here */
+        req->hdr.SessionId = ses->Suid;
+
+        rc = SendReceiveNoRsp(xid, ses, (char *) &req->hdr, 0);
+        /*
+         * No tcon so can't do
+         * cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_fail[SMB2...]);
+         */
+        return rc;
+}