source4/smb_server/smb2/sesssetup.c

   1 /*
   2    Unix SMB2 implementation.
   3
   4    Copyright (C) Andrew Bartlett        2001-2005
   5    Copyright (C) Stefan Metzmacher      2005
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include <tevent.h>
  23 #include "auth/gensec/gensec.h"
  24 #include "auth/auth.h"
  25 #include "libcli/smb2/smb2.h"
  26 #include "libcli/smb2/smb2_calls.h"
  27 #include "smb_server/smb_server.h"
  28 #include "smb_server/smb2/smb2_server.h"
  29 #include "smbd/service_stream.h"
  30 #include "lib/stream/packet.h"
  31
  32 static void smb2srv_sesssetup_send(struct smb2srv_request *req, union smb_sesssetup *io)
  33 {
  34         if (NT_STATUS_IS_OK(req->status)) {
  35                 /* nothing */
  36         } else if (NT_STATUS_EQUAL(req->status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
  37                 /* nothing */
  38         } else {
  39                 smb2srv_send_error(req, req->status);
  40                 return;
  41         }
  42
  43         SMB2SRV_CHECK(smb2srv_setup_reply(req, 0x08, true, io->smb2.out.secblob.length));
  44
  45         SBVAL(req->out.hdr, SMB2_HDR_SESSION_ID,        io->smb2.out.uid);
  46
  47         SSVAL(req->out.body, 0x02, io->smb2.out.session_flags);
  48         SMB2SRV_CHECK(smb2_push_o16s16_blob(&req->out, 0x04, io->smb2.out.secblob));
  49
  50         smb2srv_send_reply(req);
  51 }
  52
  53 struct smb2srv_sesssetup_callback_ctx {
  54         struct smb2srv_request *req;
  55         union smb_sesssetup *io;
  56         struct smbsrv_session *smb_sess;
  57 };
  58
  59 static void smb2srv_sesssetup_callback(struct tevent_req *subreq)
  60 {
  61         struct smb2srv_sesssetup_callback_ctx *ctx = tevent_req_callback_data(subreq,
  62                                                      struct smb2srv_sesssetup_callback_ctx);
  63         struct smb2srv_request *req = ctx->req;
  64         union smb_sesssetup *io = ctx->io;
  65         struct smbsrv_session *smb_sess = ctx->smb_sess;
  66         struct auth_session_info *session_info = NULL;
  67         enum security_user_level user_level;
  68         NTSTATUS status;
  69
  70         packet_recv_enable(req->smb_conn->packet);
  71
  72         status = gensec_update_recv(subreq, req, &io->smb2.out.secblob);
  73         TALLOC_FREE(subreq);
  74         if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
  75                 goto done;
  76         } else if (!NT_STATUS_IS_OK(status)) {
  77                 goto failed;
  78         }
  79
  80         status = gensec_session_info(smb_sess->gensec_ctx, smb_sess, &session_info);
  81         if (!NT_STATUS_IS_OK(status)) {
  82                 goto failed;
  83         }
  84
  85         /* Ensure this is marked as a 'real' vuid, not one
  86          * simply valid for the session setup leg */
  87         status = smbsrv_session_sesssetup_finished(smb_sess, session_info);
  88         if (!NT_STATUS_IS_OK(status)) {
  89                 goto failed;
  90         }
  91         req->session = smb_sess;
  92
  93         user_level = security_session_user_level(smb_sess->session_info, NULL);
  94         if (user_level >= SECURITY_USER) {
  95                 if (smb_sess->smb2_signing.required) {
  96                         /* activate smb2 signing on the session */
  97                         smb_sess->smb2_signing.active = true;
  98                 }
  99                 /* we need to sign the session setup response */
 100                 req->is_signed = true;
 101         }
 102
 103 done:
 104         io->smb2.out.uid = smb_sess->vuid;
 105 failed:
 106         req->status = nt_status_squash(status);
 107         smb2srv_sesssetup_send(req, io);
 108         if (!NT_STATUS_IS_OK(status) && !
 109             NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 110                 talloc_free(smb_sess);
 111         }
 112 }
 113
 114 static void smb2srv_sesssetup_backend(struct smb2srv_request *req, union smb_sesssetup *io)
 115 {
 116         NTSTATUS status;
 117         struct smb2srv_sesssetup_callback_ctx *callback_ctx;
 118         struct smbsrv_session *smb_sess = NULL;
 119         uint64_t vuid;
 120         struct tevent_req *subreq;
 121
 122         io->smb2.out.session_flags = 0;
 123         io->smb2.out.uid        = 0;
 124         io->smb2.out.secblob = data_blob(NULL, 0);
 125
 126         vuid = BVAL(req->in.hdr, SMB2_HDR_SESSION_ID);
 127
 128         /*
 129          * only when we got '0' we should allocate a new session
 130          */
 131         if (vuid == 0) {
 132                 struct gensec_security *gensec_ctx;
 133
 134                 status = samba_server_gensec_start(req,
 135                                                    req->smb_conn->connection->event.ctx,
 136                                                    req->smb_conn->connection->msg_ctx,
 137                                                    req->smb_conn->lp_ctx,
 138                                                    req->smb_conn->negotiate.server_credentials,
 139                                                    "cifs",
 140                                                    &gensec_ctx);
 141                 if (!NT_STATUS_IS_OK(status)) {
 142                         DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
 143                         goto failed;
 144                 }
 145
 146                 gensec_want_feature(gensec_ctx, GENSEC_FEATURE_SESSION_KEY);
 147
 148                 status = gensec_start_mech_by_oid(gensec_ctx, GENSEC_OID_SPNEGO);
 149                 if (!NT_STATUS_IS_OK(status)) {
 150                         DEBUG(1, ("Failed to start GENSEC SPNEGO server code: %s\n", nt_errstr(status)));
 151                         goto failed;
 152                 }
 153
 154                 /* allocate a new session */
 155                 smb_sess = smbsrv_session_new(req->smb_conn, req->smb_conn, gensec_ctx);
 156                 if (!smb_sess) {
 157                         status = NT_STATUS_INSUFFICIENT_RESOURCES;
 158                         goto failed;
 159                 }
 160                 status = smbsrv_smb2_init_tcons(smb_sess);
 161                 if (!NT_STATUS_IS_OK(status)) {
 162                         goto failed;
 163                 }
 164         } else {
 165                 /* lookup an existing session */
 166                 smb_sess = smbsrv_session_find_sesssetup(req->smb_conn, vuid);
 167         }
 168
 169         if (!smb_sess) {
 170                 /* see WSPP test suite - test 11 */
 171                 status = NT_STATUS_REQUEST_NOT_ACCEPTED;
 172                 goto failed;
 173         }
 174
 175         if (!smb_sess->gensec_ctx) {
 176                 status = NT_STATUS_INTERNAL_ERROR;
 177                 DEBUG(1, ("Internal ERROR: no gensec_ctx on session: %s\n", nt_errstr(status)));
 178                 goto failed;
 179         }
 180
 181         callback_ctx = talloc(req, struct smb2srv_sesssetup_callback_ctx);
 182         if (!callback_ctx) goto nomem;
 183         callback_ctx->req       = req;
 184         callback_ctx->io        = io;
 185         callback_ctx->smb_sess  = smb_sess;
 186
 187         subreq = gensec_update_send(callback_ctx,
 188                                     req->smb_conn->connection->event.ctx,
 189                                     smb_sess->gensec_ctx,
 190                                     io->smb2.in.secblob);
 191         if (!subreq) goto nomem;
 192         tevent_req_set_callback(subreq, smb2srv_sesssetup_callback, callback_ctx);
 193
 194         /* note that we ignore SMB2_NEGOTIATE_SIGNING_ENABLED from the client.
 195            This is deliberate as windows does not set it even when it does
 196            set SMB2_NEGOTIATE_SIGNING_REQUIRED */
 197         if (io->smb2.in.security_mode & SMB2_NEGOTIATE_SIGNING_REQUIRED) {
 198                 smb_sess->smb2_signing.required = true;
 199         } else if (req->smb_conn->smb2_signing_required) {
 200                 /*
 201                  * if required signing was negotiates in SMB2 Negotiate
 202                  * then the client made an error not using it here
 203                  */
 204                 DEBUG(1, ("SMB2 signing required on the connection but not used on session\n"));
 205                 req->status = NT_STATUS_FOOBAR;
 206                 goto failed;
 207         }
 208
 209         /* disable receipt of more packets on this socket until we've
 210            finished with the session setup. This avoids a problem with
 211            crashes if we get EOF on the socket while processing a session
 212            setup */
 213         packet_recv_disable(req->smb_conn->packet);
 214
 215         return;
 216 nomem:
 217         status = NT_STATUS_NO_MEMORY;
 218 failed:
 219         talloc_free(smb_sess);
 220         req->status = nt_status_squash(status);
 221         smb2srv_sesssetup_send(req, io);
 222 }
 223
 224 void smb2srv_sesssetup_recv(struct smb2srv_request *req)
 225 {
 226         union smb_sesssetup *io;
 227
 228         SMB2SRV_CHECK_BODY_SIZE(req, 0x18, true);
 229         SMB2SRV_TALLOC_IO_PTR(io, union smb_sesssetup);
 230
 231         io->smb2.level                 = RAW_SESSSETUP_SMB2;
 232         io->smb2.in.vc_number          = CVAL(req->in.body, 0x02);
 233         io->smb2.in.security_mode      = CVAL(req->in.body, 0x03);
 234         io->smb2.in.capabilities       = IVAL(req->in.body, 0x04);
 235         io->smb2.in.channel            = IVAL(req->in.body, 0x08);
 236         io->smb2.in.previous_sessionid = BVAL(req->in.body, 0x10);
 237         SMB2SRV_CHECK(smb2_pull_o16s16_blob(&req->in, io, req->in.body+0x0C, &io->smb2.in.secblob));
 238
 239         smb2srv_sesssetup_backend(req, io);
 240 }
 241
 242 static int smb2srv_cleanup_session_destructor(struct smbsrv_session **session)
 243 {
 244         /* TODO: call ntvfs backends to close file of this session */
 245         DEBUG(0,("free session[%p]\n", *session));
 246         talloc_free(*session);
 247         return 0;
 248 }
 249
 250 static NTSTATUS smb2srv_logoff_backend(struct smb2srv_request *req)
 251 {
 252         struct smbsrv_session **session_ptr;
 253
 254         /* we need to destroy the session after sending the reply */
 255         session_ptr = talloc(req, struct smbsrv_session *);
 256         NT_STATUS_HAVE_NO_MEMORY(session_ptr);
 257
 258         *session_ptr = req->session;
 259         talloc_set_destructor(session_ptr, smb2srv_cleanup_session_destructor);
 260
 261         return NT_STATUS_OK;
 262 }
 263
 264 static void smb2srv_logoff_send(struct smb2srv_request *req)
 265 {
 266         if (NT_STATUS_IS_ERR(req->status)) {
 267                 smb2srv_send_error(req, req->status);
 268                 return;
 269         }
 270
 271         SMB2SRV_CHECK(smb2srv_setup_reply(req, 0x04, false, 0));
 272
 273         SSVAL(req->out.body, 0x02, 0);
 274
 275         smb2srv_send_reply(req);
 276 }
 277
 278 void smb2srv_logoff_recv(struct smb2srv_request *req)
 279 {
 280         uint16_t _pad;
 281
 282         SMB2SRV_CHECK_BODY_SIZE(req, 0x04, false);
 283
 284         _pad    = SVAL(req->in.body, 0x02);
 285
 286         req->status = smb2srv_logoff_backend(req);
 287
 288         if (req->control_flags & SMB2SRV_REQ_CTRL_FLAG_NOT_REPLY) {
 289                 talloc_free(req);
 290                 return;
 291         }
 292         smb2srv_logoff_send(req);
 293 }