source: branches/samba-3.5.x/source4/smb_server/smb2/sesssetup.c

/* 
   Unix SMB2 implementation.
   
   Copyright (C) Andrew Bartlett        2001-2005
   Copyright (C) Stefan Metzmacher      2005
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program 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 General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "auth/gensec/gensec.h"
#include "auth/auth.h"
#include "libcli/smb2/smb2.h"
#include "libcli/smb2/smb2_calls.h"
#include "smb_server/smb_server.h"
#include "smb_server/smb2/smb2_server.h"
#include "smbd/service_stream.h"

static void smb2srv_sesssetup_send(struct smb2srv_request *req, union smb_sesssetup *io)
{
        uint16_t credit;

        if (NT_STATUS_IS_OK(req->status)) {
                credit = 0x0003;
        } else if (NT_STATUS_EQUAL(req->status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
                credit = 0x0002;
        } else {
                smb2srv_send_error(req, req->status);
                return;
        }

        SMB2SRV_CHECK(smb2srv_setup_reply(req, 0x08, true, io->smb2.out.secblob.length));

        SSVAL(req->out.hdr, SMB2_HDR_CREDIT,    credit);
        SBVAL(req->out.hdr, SMB2_HDR_SESSION_ID,        io->smb2.out.uid);

        SSVAL(req->out.body, 0x02, io->smb2.out.session_flags);
        SMB2SRV_CHECK(smb2_push_o16s16_blob(&req->out, 0x04, io->smb2.out.secblob));

        smb2srv_send_reply(req);
}

struct smb2srv_sesssetup_callback_ctx {
        struct smb2srv_request *req;
        union smb_sesssetup *io;
        struct smbsrv_session *smb_sess;
};

static void smb2srv_sesssetup_callback(struct gensec_update_request *greq, void *private_data)
{
        struct smb2srv_sesssetup_callback_ctx *ctx = talloc_get_type(private_data,
                                                     struct smb2srv_sesssetup_callback_ctx);
        struct smb2srv_request *req = ctx->req;
        union smb_sesssetup *io = ctx->io;
        struct smbsrv_session *smb_sess = ctx->smb_sess;
        struct auth_session_info *session_info = NULL;
        NTSTATUS status;

        status = gensec_update_recv(greq, req, &io->smb2.out.secblob);
        if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
                goto done;
        } else if (!NT_STATUS_IS_OK(status)) {
                goto failed;
        }

        status = gensec_session_info(smb_sess->gensec_ctx, &session_info);
        if (!NT_STATUS_IS_OK(status)) {
                goto failed;
        }

        /* Ensure this is marked as a 'real' vuid, not one
         * simply valid for the session setup leg */
        status = smbsrv_session_sesssetup_finished(smb_sess, session_info);
        if (!NT_STATUS_IS_OK(status)) {
                goto failed;
        }
        req->session = smb_sess;

        if (smb_sess->smb2_signing.required) {
                /* activate smb2 signing on the session */
                smb_sess->smb2_signing.active = true;
        }
done:
        io->smb2.out.uid = smb_sess->vuid;
failed:
        req->status = auth_nt_status_squash(status);
        smb2srv_sesssetup_send(req, io);
        if (!NT_STATUS_IS_OK(status) && !
            NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
                talloc_free(smb_sess);
        }
}

static void smb2srv_sesssetup_backend(struct smb2srv_request *req, union smb_sesssetup *io)
{
        NTSTATUS status;
        struct smb2srv_sesssetup_callback_ctx *callback_ctx;
        struct smbsrv_session *smb_sess = NULL;
        uint64_t vuid;

        io->smb2.out.session_flags = 0;
        io->smb2.out.uid        = 0;
        io->smb2.out.secblob = data_blob(NULL, 0);

        vuid = BVAL(req->in.hdr, SMB2_HDR_SESSION_ID);

        /*
         * only when we got '0' we should allocate a new session
         */
        if (vuid == 0) {
                struct gensec_security *gensec_ctx;

                status = samba_server_gensec_start(req,
                                                   req->smb_conn->connection->event.ctx,
                                                   req->smb_conn->connection->msg_ctx,
                                                   req->smb_conn->lp_ctx,
                                                   req->smb_conn->negotiate.server_credentials,
                                                   "cifs",
                                                   &gensec_ctx);
                if (!NT_STATUS_IS_OK(status)) {
                        DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
                        goto failed;
                }

                gensec_want_feature(gensec_ctx, GENSEC_FEATURE_SESSION_KEY);

                status = gensec_start_mech_by_oid(gensec_ctx, GENSEC_OID_SPNEGO);
                if (!NT_STATUS_IS_OK(status)) {
                        DEBUG(1, ("Failed to start GENSEC SPNEGO server code: %s\n", nt_errstr(status)));
                        goto failed;
                }

                /* allocate a new session */
                smb_sess = smbsrv_session_new(req->smb_conn, req->smb_conn, gensec_ctx);
                if (!smb_sess) {
                        status = NT_STATUS_INSUFFICIENT_RESOURCES;
                        goto failed;
                }
                status = smbsrv_smb2_init_tcons(smb_sess);
                if (!NT_STATUS_IS_OK(status)) {
                        goto failed;
                }
        } else {
                /* lookup an existing session */
                smb_sess = smbsrv_session_find_sesssetup(req->smb_conn, vuid);
        }

        if (!smb_sess) {
                /* see WSPP test suite - test 11 */
                status = NT_STATUS_REQUEST_NOT_ACCEPTED;
                goto failed;
        }

        if (!smb_sess->gensec_ctx) {
                status = NT_STATUS_INTERNAL_ERROR;
                DEBUG(1, ("Internal ERROR: no gensec_ctx on session: %s\n", nt_errstr(status)));
                goto failed;
        }

        callback_ctx = talloc(req, struct smb2srv_sesssetup_callback_ctx);
        if (!callback_ctx) goto nomem;
        callback_ctx->req       = req;
        callback_ctx->io        = io;
        callback_ctx->smb_sess  = smb_sess;

        gensec_update_send(smb_sess->gensec_ctx, io->smb2.in.secblob,
                           smb2srv_sesssetup_callback, callback_ctx);

        /* note that we ignore SMB2_NEGOTIATE_SIGNING_ENABLED from the client.
           This is deliberate as windows does not set it even when it does 
           set SMB2_NEGOTIATE_SIGNING_REQUIRED */
        if (io->smb2.in.security_mode & SMB2_NEGOTIATE_SIGNING_REQUIRED) {
                smb_sess->smb2_signing.required = true;
        } else if (req->smb_conn->smb2_signing_required) {
                /*
                 * if required signing was negotiates in SMB2 Negotiate
                 * then the client made an error not using it here
                 */
                DEBUG(1, ("SMB2 signing required on the connection but not used on session\n"));
                req->status = NT_STATUS_FOOBAR;
                goto failed;
        }

        return;
nomem:
        status = NT_STATUS_NO_MEMORY;
failed:
        talloc_free(smb_sess);
        req->status = auth_nt_status_squash(status);
        smb2srv_sesssetup_send(req, io);
}

void smb2srv_sesssetup_recv(struct smb2srv_request *req)
{
        union smb_sesssetup *io;

        SMB2SRV_CHECK_BODY_SIZE(req, 0x18, true);
        SMB2SRV_TALLOC_IO_PTR(io, union smb_sesssetup);

        io->smb2.level                 = RAW_SESSSETUP_SMB2;
        io->smb2.in.vc_number          = CVAL(req->in.body, 0x02);
        io->smb2.in.security_mode      = CVAL(req->in.body, 0x03);
        io->smb2.in.capabilities       = IVAL(req->in.body, 0x04);
        io->smb2.in.channel            = IVAL(req->in.body, 0x08);
        io->smb2.in.previous_sessionid = BVAL(req->in.body, 0x10);
        SMB2SRV_CHECK(smb2_pull_o16s16_blob(&req->in, io, req->in.body+0x0C, &io->smb2.in.secblob));

        smb2srv_sesssetup_backend(req, io);
}

static int smb2srv_cleanup_session_destructor(struct smbsrv_session **session)
{
        /* TODO: call ntvfs backends to close file of this session */
        DEBUG(0,("free session[%p]\n", *session));
        talloc_free(*session);
        return 0;
}

static NTSTATUS smb2srv_logoff_backend(struct smb2srv_request *req)
{
        struct smbsrv_session **session_ptr;

        /* we need to destroy the session after sending the reply */
        session_ptr = talloc(req, struct smbsrv_session *);
        NT_STATUS_HAVE_NO_MEMORY(session_ptr);

        *session_ptr = req->session;
        talloc_set_destructor(session_ptr, smb2srv_cleanup_session_destructor);

        return NT_STATUS_OK;
}

static void smb2srv_logoff_send(struct smb2srv_request *req)
{
        if (NT_STATUS_IS_ERR(req->status)) {
                smb2srv_send_error(req, req->status);
                return;
        }

        SMB2SRV_CHECK(smb2srv_setup_reply(req, 0x04, false, 0));

        SSVAL(req->out.body, 0x02, 0);

        smb2srv_send_reply(req);
}

void smb2srv_logoff_recv(struct smb2srv_request *req)
{
        uint16_t _pad;

        SMB2SRV_CHECK_BODY_SIZE(req, 0x04, false);

        _pad    = SVAL(req->in.body, 0x02);

        req->status = smb2srv_logoff_backend(req);

        if (req->control_flags & SMB2SRV_REQ_CTRL_FLAG_NOT_REPLY) {
                talloc_free(req);
                return;
        }
        smb2srv_logoff_send(req);
}