source4/smb_server/smb/negprot.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    negprot reply code
   4    Copyright (C) Andrew Tridgell 1992-1998
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "auth/credentials/credentials.h"
  22 #include "auth/gensec/gensec.h"
  23 #include "auth/auth.h"
  24 #include "smb_server/smb_server.h"
  25 #include "libcli/smb2/smb2.h"
  26 #include "smb_server/smb2/smb2_server.h"
  27 #include "smbd/service_stream.h"
  28 #include "lib/stream/packet.h"
  29 #include "param/param.h"
  30
  31
  32 /* initialise the auth_context for this server and return the cryptkey */
  33 static NTSTATUS get_challenge(struct smbsrv_connection *smb_conn, uint8_t buff[8])
  34 {
  35         NTSTATUS nt_status;
  36
  37         /* muliple negprots are not premitted */
  38         if (smb_conn->negotiate.auth_context) {
  39                 DEBUG(3,("get challenge: is this a secondary negprot?  auth_context is non-NULL!\n"));
  40                 return NT_STATUS_FOOBAR;
  41         }
  42
  43         DEBUG(10, ("get challenge: creating negprot_global_auth_context\n"));
  44
  45         nt_status = auth_context_create(smb_conn,
  46                                         smb_conn->connection->event.ctx,
  47                                         smb_conn->connection->msg_ctx,
  48                                         smb_conn->lp_ctx,
  49                                         &smb_conn->negotiate.auth_context);
  50         if (!NT_STATUS_IS_OK(nt_status)) {
  51                 DEBUG(0, ("auth_context_create() returned %s", nt_errstr(nt_status)));
  52                 return nt_status;
  53         }
  54
  55         nt_status = auth_get_challenge(smb_conn->negotiate.auth_context, buff);
  56         if (!NT_STATUS_IS_OK(nt_status)) {
  57                 DEBUG(0, ("auth_get_challenge() returned %s", nt_errstr(nt_status)));
  58                 return nt_status;
  59         }
  60
  61         return NT_STATUS_OK;
  62 }
  63
  64 /****************************************************************************
  65  Reply for the core protocol.
  66 ****************************************************************************/
  67 static void reply_corep(struct smbsrv_request *req, uint16_t choice)
  68 {
  69         smbsrv_setup_reply(req, 1, 0);
  70
  71         SSVAL(req->out.vwv, VWV(0), choice);
  72
  73         req->smb_conn->negotiate.protocol = PROTOCOL_CORE;
  74
  75         if (req->smb_conn->signing.mandatory_signing) {
  76                 smbsrv_terminate_connection(req->smb_conn,
  77                                             "CORE does not support SMB signing, and it is mandatory\n");
  78                 return;
  79         }
  80
  81         smbsrv_send_reply(req);
  82 }
  83
  84 /****************************************************************************
  85  Reply for the coreplus protocol.
  86 this is quite incomplete - we only fill in a small part of the reply, but as nobody uses
  87 this any more it probably doesn't matter
  88 ****************************************************************************/
  89 static void reply_coreplus(struct smbsrv_request *req, uint16_t choice)
  90 {
  91         uint16_t raw = (lpcfg_readraw(req->smb_conn->lp_ctx)?1:0) | (lpcfg_writeraw(req->smb_conn->lp_ctx)?2:0);
  92
  93         smbsrv_setup_reply(req, 13, 0);
  94
  95         /* Reply, SMBlockread, SMBwritelock supported. */
  96         SCVAL(req->out.hdr,HDR_FLG,
  97               CVAL(req->out.hdr, HDR_FLG) | FLAG_SUPPORT_LOCKREAD);
  98
  99         SSVAL(req->out.vwv, VWV(0), choice);
 100         SSVAL(req->out.vwv, VWV(1), 0x1); /* user level security, don't encrypt */
 101
 102         /* tell redirector we support
 103            readbraw and writebraw (possibly) */
 104         SSVAL(req->out.vwv, VWV(5), raw);
 105
 106         req->smb_conn->negotiate.protocol = PROTOCOL_COREPLUS;
 107
 108         if (req->smb_conn->signing.mandatory_signing) {
 109                 smbsrv_terminate_connection(req->smb_conn,
 110                                             "COREPLUS does not support SMB signing, and it is mandatory\n");
 111                 return;
 112         }
 113
 114         smbsrv_send_reply(req);
 115 }
 116
 117 /****************************************************************************
 118  Reply for the lanman 1.0 protocol.
 119 ****************************************************************************/
 120 static void reply_lanman1(struct smbsrv_request *req, uint16_t choice)
 121 {
 122         int raw = (lpcfg_readraw(req->smb_conn->lp_ctx)?1:0) | (lpcfg_writeraw(req->smb_conn->lp_ctx)?2:0);
 123         int secword=0;
 124         time_t t = req->request_time.tv_sec;
 125
 126         req->smb_conn->negotiate.encrypted_passwords = lpcfg_encrypted_passwords(req->smb_conn->lp_ctx);
 127
 128         if (req->smb_conn->negotiate.encrypted_passwords)
 129                 secword |= NEGOTIATE_SECURITY_CHALLENGE_RESPONSE;
 130
 131         req->smb_conn->negotiate.protocol = PROTOCOL_LANMAN1;
 132
 133         smbsrv_setup_reply(req, 13, req->smb_conn->negotiate.encrypted_passwords ? 8 : 0);
 134
 135         /* SMBlockread, SMBwritelock supported. */
 136         SCVAL(req->out.hdr,HDR_FLG,
 137               CVAL(req->out.hdr, HDR_FLG) | FLAG_SUPPORT_LOCKREAD);
 138
 139         SSVAL(req->out.vwv, VWV(0), choice);
 140         SSVAL(req->out.vwv, VWV(1), secword);
 141         SSVAL(req->out.vwv, VWV(2), req->smb_conn->negotiate.max_recv);
 142         SSVAL(req->out.vwv, VWV(3), lpcfg_max_mux(req->smb_conn->lp_ctx));
 143         SSVAL(req->out.vwv, VWV(4), 1);
 144         SSVAL(req->out.vwv, VWV(5), raw);
 145         SIVAL(req->out.vwv, VWV(6), req->smb_conn->connection->server_id.pid);
 146         srv_push_dos_date(req->smb_conn, req->out.vwv, VWV(8), t);
 147         SSVAL(req->out.vwv, VWV(10), req->smb_conn->negotiate.zone_offset/60);
 148         SIVAL(req->out.vwv, VWV(11), 0); /* reserved */
 149
 150         /* Create a token value and add it to the outgoing packet. */
 151         if (req->smb_conn->negotiate.encrypted_passwords) {
 152                 NTSTATUS nt_status;
 153
 154                 SSVAL(req->out.vwv, VWV(11), 8);
 155
 156                 nt_status = get_challenge(req->smb_conn, req->out.data);
 157                 if (!NT_STATUS_IS_OK(nt_status)) {
 158                         smbsrv_terminate_connection(req->smb_conn, "LANMAN1 get_challenge failed\n");
 159                         return;
 160                 }
 161         }
 162
 163         if (req->smb_conn->signing.mandatory_signing) {
 164                 smbsrv_terminate_connection(req->smb_conn,
 165                                             "LANMAN1 does not support SMB signing, and it is mandatory\n");
 166                 return;
 167         }
 168
 169         smbsrv_send_reply(req);
 170 }
 171
 172 /****************************************************************************
 173  Reply for the lanman 2.0 protocol.
 174 ****************************************************************************/
 175 static void reply_lanman2(struct smbsrv_request *req, uint16_t choice)
 176 {
 177         int raw = (lpcfg_readraw(req->smb_conn->lp_ctx)?1:0) | (lpcfg_writeraw(req->smb_conn->lp_ctx)?2:0);
 178         int secword=0;
 179         time_t t = req->request_time.tv_sec;
 180
 181         req->smb_conn->negotiate.encrypted_passwords = lpcfg_encrypted_passwords(req->smb_conn->lp_ctx);
 182
 183         if (req->smb_conn->negotiate.encrypted_passwords)
 184                 secword |= NEGOTIATE_SECURITY_CHALLENGE_RESPONSE;
 185
 186         req->smb_conn->negotiate.protocol = PROTOCOL_LANMAN2;
 187
 188         smbsrv_setup_reply(req, 13, 0);
 189
 190         SSVAL(req->out.vwv, VWV(0), choice);
 191         SSVAL(req->out.vwv, VWV(1), secword);
 192         SSVAL(req->out.vwv, VWV(2), req->smb_conn->negotiate.max_recv);
 193         SSVAL(req->out.vwv, VWV(3), lpcfg_max_mux(req->smb_conn->lp_ctx));
 194         SSVAL(req->out.vwv, VWV(4), 1);
 195         SSVAL(req->out.vwv, VWV(5), raw);
 196         SIVAL(req->out.vwv, VWV(6), req->smb_conn->connection->server_id.pid);
 197         srv_push_dos_date(req->smb_conn, req->out.vwv, VWV(8), t);
 198         SSVAL(req->out.vwv, VWV(10), req->smb_conn->negotiate.zone_offset/60);
 199         SIVAL(req->out.vwv, VWV(11), 0);
 200
 201         /* Create a token value and add it to the outgoing packet. */
 202         if (req->smb_conn->negotiate.encrypted_passwords) {
 203                 SSVAL(req->out.vwv, VWV(11), 8);
 204                 req_grow_data(req, 8);
 205                 get_challenge(req->smb_conn, req->out.data);
 206         }
 207
 208         req_push_str(req, NULL, lpcfg_workgroup(req->smb_conn->lp_ctx), -1, STR_TERMINATE);
 209
 210         if (req->smb_conn->signing.mandatory_signing) {
 211                 smbsrv_terminate_connection(req->smb_conn,
 212                                             "LANMAN2 does not support SMB signing, and it is mandatory\n");
 213                 return;
 214         }
 215
 216         smbsrv_send_reply(req);
 217 }
 218
 219 static void reply_nt1_orig(struct smbsrv_request *req)
 220 {
 221         /* Create a token value and add it to the outgoing packet. */
 222         if (req->smb_conn->negotiate.encrypted_passwords) {
 223                 req_grow_data(req, 8);
 224                 /* note that we do not send a challenge at all if
 225                    we are using plaintext */
 226                 get_challenge(req->smb_conn, req->out.ptr);
 227                 req->out.ptr += 8;
 228                 SCVAL(req->out.vwv+1, VWV(16), 8);
 229         }
 230         req_push_str(req, NULL, lpcfg_workgroup(req->smb_conn->lp_ctx), -1, STR_UNICODE|STR_TERMINATE|STR_NOALIGN);
 231         req_push_str(req, NULL, lpcfg_netbios_name(req->smb_conn->lp_ctx), -1, STR_UNICODE|STR_TERMINATE|STR_NOALIGN);
 232         DEBUG(3,("not using extended security (SPNEGO or NTLMSSP)\n"));
 233 }
 234
 235 /****************************************************************************
 236  Reply for the nt protocol.
 237 ****************************************************************************/
 238 static void reply_nt1(struct smbsrv_request *req, uint16_t choice)
 239 {
 240         /* dual names + lock_and_read + nt SMBs + remote API calls */
 241         int capabilities;
 242         int secword=0;
 243         time_t t = req->request_time.tv_sec;
 244         NTTIME nttime;
 245         bool negotiate_spnego = false;
 246         char *large_test_path;
 247
 248         unix_to_nt_time(&nttime, t);
 249
 250         capabilities =
 251                 CAP_NT_FIND | CAP_LOCK_AND_READ |
 252                 CAP_LEVEL_II_OPLOCKS | CAP_NT_SMBS | CAP_RPC_REMOTE_APIS;
 253
 254         req->smb_conn->negotiate.encrypted_passwords = lpcfg_encrypted_passwords(req->smb_conn->lp_ctx);
 255
 256         /* do spnego in user level security if the client
 257            supports it and we can do encrypted passwords */
 258
 259         if (req->smb_conn->negotiate.encrypted_passwords &&
 260             lpcfg_use_spnego(req->smb_conn->lp_ctx) &&
 261             (req->flags2 & FLAGS2_EXTENDED_SECURITY)) {
 262                 negotiate_spnego = true;
 263                 capabilities |= CAP_EXTENDED_SECURITY;
 264         }
 265
 266         if (lpcfg_large_readwrite(req->smb_conn->lp_ctx)) {
 267                 capabilities |= CAP_LARGE_READX | CAP_LARGE_WRITEX | CAP_W2K_SMBS;
 268         }
 269
 270         large_test_path = lpcfg_lock_path(req, req->smb_conn->lp_ctx, "large_test.dat");
 271         if (large_file_support(large_test_path)) {
 272                 capabilities |= CAP_LARGE_FILES;
 273         }
 274
 275         if (lpcfg_readraw(req->smb_conn->lp_ctx) &&
 276             lpcfg_writeraw(req->smb_conn->lp_ctx)) {
 277                 capabilities |= CAP_RAW_MODE;
 278         }
 279
 280         /* allow for disabling unicode */
 281         if (lpcfg_unicode(req->smb_conn->lp_ctx)) {
 282                 capabilities |= CAP_UNICODE;
 283         }
 284
 285         if (lpcfg_nt_status_support(req->smb_conn->lp_ctx)) {
 286                 capabilities |= CAP_STATUS32;
 287         }
 288
 289         if (lpcfg_host_msdfs(req->smb_conn->lp_ctx)) {
 290                 capabilities |= CAP_DFS;
 291         }
 292
 293         secword |= NEGOTIATE_SECURITY_USER_LEVEL;
 294
 295         if (req->smb_conn->negotiate.encrypted_passwords) {
 296                 secword |= NEGOTIATE_SECURITY_CHALLENGE_RESPONSE;
 297         }
 298
 299         if (req->smb_conn->signing.allow_smb_signing) {
 300                 secword |= NEGOTIATE_SECURITY_SIGNATURES_ENABLED;
 301         }
 302
 303         if (req->smb_conn->signing.mandatory_signing) {
 304                 secword |= NEGOTIATE_SECURITY_SIGNATURES_REQUIRED;
 305         }
 306
 307         req->smb_conn->negotiate.protocol = PROTOCOL_NT1;
 308
 309         smbsrv_setup_reply(req, 17, 0);
 310
 311         SSVAL(req->out.vwv, VWV(0), choice);
 312         SCVAL(req->out.vwv, VWV(1), secword);
 313
 314         /* notice the strange +1 on vwv here? That's because
 315            this is the one and only SMB packet that is malformed in
 316            the specification - all the command words after the secword
 317            are offset by 1 byte */
 318         SSVAL(req->out.vwv+1, VWV(1), lpcfg_max_mux(req->smb_conn->lp_ctx));
 319         SSVAL(req->out.vwv+1, VWV(2), 1); /* num vcs */
 320         SIVAL(req->out.vwv+1, VWV(3), req->smb_conn->negotiate.max_recv);
 321         SIVAL(req->out.vwv+1, VWV(5), 0x10000); /* raw size. full 64k */
 322         SIVAL(req->out.vwv+1, VWV(7), req->smb_conn->connection->server_id.pid); /* session key */
 323
 324         SIVAL(req->out.vwv+1, VWV(9), capabilities);
 325         push_nttime(req->out.vwv+1, VWV(11), nttime);
 326         SSVALS(req->out.vwv+1,VWV(15), req->smb_conn->negotiate.zone_offset/60);
 327
 328         if (!negotiate_spnego) {
 329                 reply_nt1_orig(req);
 330         } else {
 331                 struct cli_credentials *server_credentials;
 332                 struct gensec_security *gensec_security;
 333                 DATA_BLOB null_data_blob = data_blob(NULL, 0);
 334                 DATA_BLOB blob;
 335                 const char *oid;
 336                 NTSTATUS nt_status;
 337
 338                 server_credentials
 339                         = cli_credentials_init(req);
 340                 if (!server_credentials) {
 341                         smbsrv_terminate_connection(req->smb_conn, "Failed to init server credentials\n");
 342                         return;
 343                 }
 344
 345                 cli_credentials_set_conf(server_credentials, req->smb_conn->lp_ctx);
 346                 nt_status = cli_credentials_set_machine_account(server_credentials, req->smb_conn->lp_ctx);
 347                 if (!NT_STATUS_IS_OK(nt_status)) {
 348                         DEBUG(10, ("Failed to obtain server credentials, perhaps a standalone server?: %s\n", nt_errstr(nt_status)));
 349                         talloc_free(server_credentials);
 350                         server_credentials = NULL;
 351                 }
 352
 353                 nt_status = samba_server_gensec_start(req,
 354                                                       req->smb_conn->connection->event.ctx,
 355                                                       req->smb_conn->connection->msg_ctx,
 356                                                       req->smb_conn->lp_ctx,
 357                                                       server_credentials,
 358                                                       "cifs",
 359                                                       &gensec_security);
 360
 361                 if (!NT_STATUS_IS_OK(nt_status)) {
 362                         DEBUG(0, ("Failed to start GENSEC: %s\n", nt_errstr(nt_status)));
 363                         smbsrv_terminate_connection(req->smb_conn, "Failed to start GENSEC\n");
 364                         return;
 365                 }
 366
 367                 if (req->smb_conn->negotiate.auth_context) {
 368                         smbsrv_terminate_connection(req->smb_conn, "reply_nt1: is this a secondary negprot?  auth_context is non-NULL!\n");
 369                         return;
 370                 }
 371                 req->smb_conn->negotiate.server_credentials = talloc_reparent(req, req->smb_conn, server_credentials);
 372
 373                 oid = GENSEC_OID_SPNEGO;
 374                 nt_status = gensec_start_mech_by_oid(gensec_security, oid);
 375
 376                 if (NT_STATUS_IS_OK(nt_status)) {
 377                         /* Get and push the proposed OID list into the packets */
 378                         nt_status = gensec_update(gensec_security, req, req->smb_conn->connection->event.ctx, null_data_blob, &blob);
 379
 380                         if (!NT_STATUS_IS_OK(nt_status) && !NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 381                                 DEBUG(1, ("Failed to get SPNEGO to give us the first token: %s\n", nt_errstr(nt_status)));
 382                         }
 383                 }
 384
 385                 if (NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 386                         DEBUG(3,("using SPNEGO\n"));
 387                 } else {
 388                         DEBUG(5, ("Failed to start SPNEGO, falling back to NTLMSSP only: %s\n", nt_errstr(nt_status)));
 389                         oid = GENSEC_OID_NTLMSSP;
 390                         nt_status = gensec_start_mech_by_oid(gensec_security, oid);
 391
 392                         if (!NT_STATUS_IS_OK(nt_status)) {
 393                                 DEBUG(0, ("Failed to start SPNEGO as well as NTLMSSP fallback: %s\n", nt_errstr(nt_status)));
 394                                 reply_nt1_orig(req);
 395                                 return;
 396                         }
 397                         /* NTLMSSP is a client-first exchange */
 398                         blob = data_blob(NULL, 0);
 399                         DEBUG(3,("using raw-NTLMSSP\n"));
 400                 }
 401
 402                 req->smb_conn->negotiate.oid = oid;
 403
 404                 req_grow_data(req, blob.length + 16);
 405                 /* a NOT very random guid, perhaps we should get it
 406                  * from the credentials (kitchen sink...) */
 407                 memset(req->out.ptr, '\0', 16);
 408                 req->out.ptr += 16;
 409
 410                 memcpy(req->out.ptr, blob.data, blob.length);
 411                 SCVAL(req->out.vwv+1, VWV(16), blob.length + 16);
 412                 req->out.ptr += blob.length;
 413         }
 414
 415         smbsrv_send_reply_nosign(req);
 416 }
 417
 418 /****************************************************************************
 419  Reply for the SMB2 2.001 protocol
 420 ****************************************************************************/
 421 static void reply_smb2(struct smbsrv_request *req, uint16_t choice)
 422 {
 423         struct smbsrv_connection *smb_conn = req->smb_conn;
 424         NTSTATUS status;
 425
 426         talloc_free(smb_conn->sessions.idtree_vuid);
 427         ZERO_STRUCT(smb_conn->sessions);
 428         talloc_free(smb_conn->smb_tcons.idtree_tid);
 429         ZERO_STRUCT(smb_conn->smb_tcons);
 430         ZERO_STRUCT(smb_conn->signing);
 431
 432         /* reply with a SMB2 packet */
 433         status = smbsrv_init_smb2_connection(smb_conn);
 434         if (!NT_STATUS_IS_OK(status)) {
 435                 smbsrv_terminate_connection(smb_conn, nt_errstr(status));
 436                 talloc_free(req);
 437                 return;
 438         }
 439         packet_set_callback(smb_conn->packet, smbsrv_recv_smb2_request);
 440         smb2srv_reply_smb_negprot(req);
 441         req = NULL;
 442 }
 443
 444 /* List of supported protocols, most desired first */
 445 static const struct {
 446         const char *proto_name;
 447         const char *short_name;
 448         void (*proto_reply_fn)(struct smbsrv_request *req, uint16_t choice);
 449         int protocol_level;
 450 } supported_protocols[] = {
 451         {"SMB 2.002",                   "SMB2",         reply_smb2,     PROTOCOL_SMB2_02},
 452         {"NT LANMAN 1.0",               "NT1",          reply_nt1,      PROTOCOL_NT1},
 453         {"NT LM 0.12",                  "NT1",          reply_nt1,      PROTOCOL_NT1},
 454         {"LANMAN2.1",                   "LANMAN2",      reply_lanman2,  PROTOCOL_LANMAN2},
 455         {"LM1.2X002",                   "LANMAN2",      reply_lanman2,  PROTOCOL_LANMAN2},
 456         {"Samba",                       "LANMAN2",      reply_lanman2,  PROTOCOL_LANMAN2},
 457         {"DOS LM1.2X002",               "LANMAN2",      reply_lanman2,  PROTOCOL_LANMAN2},
 458         {"Windows for Workgroups 3.1a", "LANMAN1",      reply_lanman1,  PROTOCOL_LANMAN1},
 459         {"LANMAN1.0",                   "LANMAN1",      reply_lanman1,  PROTOCOL_LANMAN1},
 460         {"MICROSOFT NETWORKS 3.0",      "LANMAN1",      reply_lanman1,  PROTOCOL_LANMAN1},
 461         {"MICROSOFT NETWORKS 1.03",     "COREPLUS",     reply_coreplus, PROTOCOL_COREPLUS},
 462         {"PC NETWORK PROGRAM 1.0",      "CORE",         reply_corep,    PROTOCOL_CORE},
 463         {NULL,NULL,NULL,0},
 464 };
 465
 466 /****************************************************************************
 467  Reply to a negprot.
 468 ****************************************************************************/
 469
 470 void smbsrv_reply_negprot(struct smbsrv_request *req)
 471 {
 472         int protocol;
 473         uint8_t *p;
 474         uint32_t protos_count = 0;
 475         char **protos = NULL;
 476
 477         if (req->smb_conn->negotiate.done_negprot) {
 478                 smbsrv_terminate_connection(req->smb_conn, "multiple negprot's are not permitted");
 479                 return;
 480         }
 481         req->smb_conn->negotiate.done_negprot = true;
 482
 483         p = req->in.data;
 484         while (true) {
 485                 size_t len;
 486
 487                 protos = talloc_realloc(req, protos, char *, protos_count + 1);
 488                 if (!protos) {
 489                         smbsrv_terminate_connection(req->smb_conn, nt_errstr(NT_STATUS_NO_MEMORY));
 490                         return;
 491                 }
 492                 protos[protos_count] = NULL;
 493                 len = req_pull_ascii4(&req->in.bufinfo, (const char **)&protos[protos_count], p, STR_ASCII|STR_TERMINATE);
 494                 p += len;
 495                 if (len == 0 || !protos[protos_count]) break;
 496
 497                 DEBUG(5,("Requested protocol [%d][%s]\n", protos_count, protos[protos_count]));
 498                 protos_count++;
 499         }
 500
 501         /* Check for protocols, most desirable first */
 502         for (protocol = 0; supported_protocols[protocol].proto_name; protocol++) {
 503                 int i;
 504
 505                 if (supported_protocols[protocol].protocol_level > lpcfg_server_max_protocol(req->smb_conn->lp_ctx))
 506                         continue;
 507                 if (supported_protocols[protocol].protocol_level < lpcfg_srv_minprotocol(req->smb_conn->lp_ctx))
 508                         continue;
 509
 510                 for (i = 0; i < protos_count; i++) {
 511                         if (strcmp(supported_protocols[protocol].proto_name, protos[i]) != 0) continue;
 512
 513                         supported_protocols[protocol].proto_reply_fn(req, i);
 514                         DEBUG(3,("Selected protocol [%d][%s]\n",
 515                                 i, supported_protocols[protocol].proto_name));
 516                         return;
 517                 }
 518         }
 519
 520         smbsrv_terminate_connection(req->smb_conn, "No protocol supported !");
 521 }