fs/cifs/sess.c

   1 /*
   2  *   fs/cifs/sess.c
   3  *
   4  *   SMB/CIFS session setup handling routines
   5  *
   6  *   Copyright (c) International Business Machines  Corp., 2006
   7  *   Author(s): Steve French (sfrench@us.ibm.com)
   8  *
   9  *   This library is free software; you can redistribute it and/or modify
  10  *   it under the terms of the GNU Lesser General Public License as published
  11  *   by the Free Software Foundation; either version 2.1 of the License, or
  12  *   (at your option) any later version.
  13  *
  14  *   This library is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  17  *   the GNU Lesser General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU Lesser General Public License
  20  *   along with this library; if not, write to the Free Software
  21  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23
  24 #include "cifspdu.h"
  25 #include "cifsglob.h"
  26 #include "cifsproto.h"
  27 #include "cifs_unicode.h"
  28 #include "cifs_debug.h"
  29 #include "ntlmssp.h"
  30 #include "nterr.h"
  31 #include <linux/utsname.h>
  32
  33 extern void SMBNTencrypt(unsigned char *passwd, unsigned char *c8,
  34                          unsigned char *p24);
  35
  36 static __u32 cifs_ssetup_hdr(struct cifsSesInfo *ses, SESSION_SETUP_ANDX *pSMB)
  37 {
  38         __u32 capabilities = 0;
  39
  40         /* init fields common to all four types of SessSetup */
  41         /* note that header is initialized to zero in header_assemble */
  42         pSMB->req.AndXCommand = 0xFF;
  43         pSMB->req.MaxBufferSize = cpu_to_le16(ses->server->maxBuf);
  44         pSMB->req.MaxMpxCount = cpu_to_le16(ses->server->maxReq);
  45
  46         /* Now no need to set SMBFLG_CASELESS or obsolete CANONICAL PATH */
  47
  48         /* BB verify whether signing required on neg or just on auth frame
  49            (and NTLM case) */
  50
  51         capabilities = CAP_LARGE_FILES | CAP_NT_SMBS | CAP_LEVEL_II_OPLOCKS |
  52                         CAP_LARGE_WRITE_X | CAP_LARGE_READ_X;
  53
  54         if(ses->server->secMode & (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
  55                 pSMB->req.hdr.Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
  56
  57         if (ses->capabilities & CAP_UNICODE) {
  58                 pSMB->req.hdr.Flags2 |= SMBFLG2_UNICODE;
  59                 capabilities |= CAP_UNICODE;
  60         }
  61         if (ses->capabilities & CAP_STATUS32) {
  62                 pSMB->req.hdr.Flags2 |= SMBFLG2_ERR_STATUS;
  63                 capabilities |= CAP_STATUS32;
  64         }
  65         if (ses->capabilities & CAP_DFS) {
  66                 pSMB->req.hdr.Flags2 |= SMBFLG2_DFS;
  67                 capabilities |= CAP_DFS;
  68         }
  69         if (ses->capabilities & CAP_UNIX) {
  70                 capabilities |= CAP_UNIX;
  71         }
  72
  73         /* BB check whether to init vcnum BB */
  74         return capabilities;
  75 }
  76
  77 static void unicode_ssetup_strings(char ** pbcc_area, struct cifsSesInfo *ses,
  78                             const struct nls_table * nls_cp)
  79 {
  80         char * bcc_ptr = *pbcc_area;
  81         int bytes_ret = 0;
  82
  83         /* BB FIXME add check that strings total less
  84         than 335 or will need to send them as arrays */
  85
  86         /* unicode strings, must be word aligned before the call */
  87 /*      if ((long) bcc_ptr % 2) {
  88                 *bcc_ptr = 0;
  89                 bcc_ptr++;
  90         } */
  91         /* copy user */
  92         if(ses->userName == NULL) {
  93                 /* BB what about null user mounts - check that we do this BB */
  94         } else { /* 300 should be long enough for any conceivable user name */
  95                 bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, ses->userName,
  96                                           300, nls_cp);
  97         }
  98         bcc_ptr += 2 * bytes_ret;
  99         bcc_ptr += 2; /* account for null termination */
 100         /* copy domain */
 101         if(ses->domainName == NULL)
 102                 bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr,
 103                                           "CIFS_LINUX_DOM", 32, nls_cp);
 104         else
 105                 bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, ses->domainName,
 106                                           256, nls_cp);
 107         bcc_ptr += 2 * bytes_ret;
 108         bcc_ptr += 2;  /* account for null terminator */
 109
 110         /* Copy OS version */
 111         bytes_ret = cifs_strtoUCS((__le16 *)bcc_ptr, "Linux version ", 32,
 112                                   nls_cp);
 113         bcc_ptr += 2 * bytes_ret;
 114         bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, init_utsname()->release,
 115                                   32, nls_cp);
 116         bcc_ptr += 2 * bytes_ret;
 117         bcc_ptr += 2; /* trailing null */
 118
 119         bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, CIFS_NETWORK_OPSYS,
 120                                   32, nls_cp);
 121         bcc_ptr += 2 * bytes_ret;
 122         bcc_ptr += 2; /* trailing null */
 123
 124         *pbcc_area = bcc_ptr;
 125 }
 126
 127 static void ascii_ssetup_strings(char ** pbcc_area, struct cifsSesInfo *ses,
 128                           const struct nls_table * nls_cp)
 129 {
 130         char * bcc_ptr = *pbcc_area;
 131
 132         /* copy user */
 133         /* BB what about null user mounts - check that we do this BB */
 134         /* copy user */
 135         if(ses->userName == NULL) {
 136                 /* BB what about null user mounts - check that we do this BB */
 137         } else { /* 300 should be long enough for any conceivable user name */
 138                 strncpy(bcc_ptr, ses->userName, 300);
 139         }
 140         /* BB improve check for overflow */
 141         bcc_ptr += strnlen(ses->userName, 300);
 142         *bcc_ptr = 0;
 143         bcc_ptr++; /* account for null termination */
 144
 145         /* copy domain */
 146
 147         if(ses->domainName == NULL) {
 148                 strcpy(bcc_ptr, "CIFS_LINUX_DOM");
 149                 bcc_ptr += 14;  /* strlen(CIFS_LINUX_DOM) */
 150         } else {
 151                 strncpy(bcc_ptr, ses->domainName, 256);
 152                 bcc_ptr += strnlen(ses->domainName, 256);
 153         }
 154         *bcc_ptr = 0;
 155         bcc_ptr++;
 156
 157         /* BB check for overflow here */
 158
 159         strcpy(bcc_ptr, "Linux version ");
 160         bcc_ptr += strlen("Linux version ");
 161         strcpy(bcc_ptr, init_utsname()->release);
 162         bcc_ptr += strlen(init_utsname()->release) + 1;
 163
 164         strcpy(bcc_ptr, CIFS_NETWORK_OPSYS);
 165         bcc_ptr += strlen(CIFS_NETWORK_OPSYS) + 1;
 166
 167         *pbcc_area = bcc_ptr;
 168 }
 169
 170 static int decode_unicode_ssetup(char ** pbcc_area, int bleft, struct cifsSesInfo *ses,
 171                             const struct nls_table * nls_cp)
 172 {
 173         int rc = 0;
 174         int words_left, len;
 175         char * data = *pbcc_area;
 176
 177
 178
 179         cFYI(1,("bleft %d",bleft));
 180
 181
 182         /* word align, if bytes remaining is not even */
 183         if(bleft % 2) {
 184                 bleft--;
 185                 data++;
 186         }
 187         words_left = bleft / 2;
 188
 189         /* save off server operating system */
 190         len = UniStrnlen((wchar_t *) data, words_left);
 191
 192 /* We look for obvious messed up bcc or strings in response so we do not go off
 193    the end since (at least) WIN2K and Windows XP have a major bug in not null
 194    terminating last Unicode string in response  */
 195         if(len >= words_left)
 196                 return rc;
 197
 198         if(ses->serverOS)
 199                 kfree(ses->serverOS);
 200         /* UTF-8 string will not grow more than four times as big as UCS-16 */
 201         ses->serverOS = kzalloc(4 * len, GFP_KERNEL);
 202         if(ses->serverOS != NULL) {
 203                 cifs_strfromUCS_le(ses->serverOS, (__le16 *)data, len,
 204                                    nls_cp);
 205         }
 206         data += 2 * (len + 1);
 207         words_left -= len + 1;
 208
 209         /* save off server network operating system */
 210         len = UniStrnlen((wchar_t *) data, words_left);
 211
 212         if(len >= words_left)
 213                 return rc;
 214
 215         if(ses->serverNOS)
 216                 kfree(ses->serverNOS);
 217         ses->serverNOS = kzalloc(4 * len, GFP_KERNEL); /* BB this is wrong length FIXME BB */
 218         if(ses->serverNOS != NULL) {
 219                 cifs_strfromUCS_le(ses->serverNOS, (__le16 *)data, len,
 220                                    nls_cp);
 221                 if(strncmp(ses->serverNOS, "NT LAN Manager 4",16) == 0) {
 222                         cFYI(1,("NT4 server"));
 223                         ses->flags |= CIFS_SES_NT4;
 224                 }
 225         }
 226         data += 2 * (len + 1);
 227         words_left -= len + 1;
 228
 229         /* save off server domain */
 230         len = UniStrnlen((wchar_t *) data, words_left);
 231
 232         if(len > words_left)
 233                 return rc;
 234
 235         if(ses->serverDomain)
 236                 kfree(ses->serverDomain);
 237         ses->serverDomain = kzalloc(2 * (len + 1), GFP_KERNEL); /* BB FIXME wrong length */
 238         if(ses->serverDomain != NULL) {
 239                 cifs_strfromUCS_le(ses->serverDomain, (__le16 *)data, len,
 240                                    nls_cp);
 241                 ses->serverDomain[2*len] = 0;
 242                 ses->serverDomain[(2*len) + 1] = 0;
 243         }
 244         data += 2 * (len + 1);
 245         words_left -= len + 1;
 246
 247         cFYI(1,("words left: %d",words_left));
 248
 249         return rc;
 250 }
 251
 252 static int decode_ascii_ssetup(char ** pbcc_area, int bleft, struct cifsSesInfo *ses,
 253                             const struct nls_table * nls_cp)
 254 {
 255         int rc = 0;
 256         int len;
 257         char * bcc_ptr = *pbcc_area;
 258
 259         cFYI(1,("decode sessetup ascii. bleft %d", bleft));
 260
 261         len = strnlen(bcc_ptr, bleft);
 262         if(len >= bleft)
 263                 return rc;
 264
 265         if(ses->serverOS)
 266                 kfree(ses->serverOS);
 267
 268         ses->serverOS = kzalloc(len + 1, GFP_KERNEL);
 269         if(ses->serverOS)
 270                 strncpy(ses->serverOS, bcc_ptr, len);
 271         if(strncmp(ses->serverOS, "OS/2",4) == 0) {
 272                         cFYI(1,("OS/2 server"));
 273                         ses->flags |= CIFS_SES_OS2;
 274         }
 275
 276         bcc_ptr += len + 1;
 277         bleft -= len + 1;
 278
 279         len = strnlen(bcc_ptr, bleft);
 280         if(len >= bleft)
 281                 return rc;
 282
 283         if(ses->serverNOS)
 284                 kfree(ses->serverNOS);
 285
 286         ses->serverNOS = kzalloc(len + 1, GFP_KERNEL);
 287         if(ses->serverNOS)
 288                 strncpy(ses->serverNOS, bcc_ptr, len);
 289
 290         bcc_ptr += len + 1;
 291         bleft -= len + 1;
 292
 293         len = strnlen(bcc_ptr, bleft);
 294         if(len > bleft)
 295                 return rc;
 296
 297         /* No domain field in LANMAN case. Domain is
 298            returned by old servers in the SMB negprot response */
 299         /* BB For newer servers which do not support Unicode,
 300            but thus do return domain here we could add parsing
 301            for it later, but it is not very important */
 302         cFYI(1,("ascii: bytes left %d",bleft));
 303
 304         return rc;
 305 }
 306
 307 int
 308 CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses, int first_time,
 309                 const struct nls_table *nls_cp)
 310 {
 311         int rc = 0;
 312         int wct;
 313         struct smb_hdr *smb_buf;
 314         char *bcc_ptr;
 315         char *str_area;
 316         SESSION_SETUP_ANDX *pSMB;
 317         __u32 capabilities;
 318         int count;
 319         int resp_buf_type = 0;
 320         struct kvec iov[2];
 321         enum securityEnum type;
 322         __u16 action;
 323         int bytes_remaining;
 324
 325         if(ses == NULL)
 326                 return -EINVAL;
 327
 328         type = ses->server->secType;
 329
 330         cFYI(1,("sess setup type %d",type));
 331         if(type == LANMAN) {
 332 #ifndef CONFIG_CIFS_WEAK_PW_HASH
 333                 /* LANMAN and plaintext are less secure and off by default.
 334                 So we make this explicitly be turned on in kconfig (in the
 335                 build) and turned on at runtime (changed from the default)
 336                 in proc/fs/cifs or via mount parm.  Unfortunately this is
 337                 needed for old Win (e.g. Win95), some obscure NAS and OS/2 */
 338                 return -EOPNOTSUPP;
 339 #endif
 340                 wct = 10; /* lanman 2 style sessionsetup */
 341         } else if((type == NTLM) || (type == NTLMv2)) {
 342                 /* For NTLMv2 failures eventually may need to retry NTLM */
 343                 wct = 13; /* old style NTLM sessionsetup */
 344         } else /* same size for negotiate or auth, NTLMSSP or extended security */
 345                 wct = 12;
 346
 347         rc = small_smb_init_no_tc(SMB_COM_SESSION_SETUP_ANDX, wct, ses,
 348                             (void **)&smb_buf);
 349         if(rc)
 350                 return rc;
 351
 352         pSMB = (SESSION_SETUP_ANDX *)smb_buf;
 353
 354         capabilities = cifs_ssetup_hdr(ses, pSMB);
 355
 356         /* we will send the SMB in two pieces,
 357         a fixed length beginning part, and a
 358         second part which will include the strings
 359         and rest of bcc area, in order to avoid having
 360         to do a large buffer 17K allocation */
 361         iov[0].iov_base = (char *)pSMB;
 362         iov[0].iov_len = smb_buf->smb_buf_length + 4;
 363
 364         /* 2000 big enough to fit max user, domain, NOS name etc. */
 365         str_area = kmalloc(2000, GFP_KERNEL);
 366         bcc_ptr = str_area;
 367
 368         ses->flags &= ~CIFS_SES_LANMAN;
 369
 370         if(type == LANMAN) {
 371 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 372                 char lnm_session_key[CIFS_SESS_KEY_SIZE];
 373
 374                 /* no capabilities flags in old lanman negotiation */
 375
 376                 pSMB->old_req.PasswordLength = cpu_to_le16(CIFS_SESS_KEY_SIZE);
 377                 /* BB calculate hash with password */
 378                 /* and copy into bcc */
 379
 380                 calc_lanman_hash(ses, lnm_session_key);
 381                 ses->flags |= CIFS_SES_LANMAN;
 382 /* #ifdef CONFIG_CIFS_DEBUG2
 383                 cifs_dump_mem("cryptkey: ",ses->server->cryptKey,
 384                         CIFS_SESS_KEY_SIZE);
 385 #endif */
 386                 memcpy(bcc_ptr, (char *)lnm_session_key, CIFS_SESS_KEY_SIZE);
 387                 bcc_ptr += CIFS_SESS_KEY_SIZE;
 388
 389                 /* can not sign if LANMAN negotiated so no need
 390                 to calculate signing key? but what if server
 391                 changed to do higher than lanman dialect and
 392                 we reconnected would we ever calc signing_key? */
 393
 394                 cFYI(1,("Negotiating LANMAN setting up strings"));
 395                 /* Unicode not allowed for LANMAN dialects */
 396                 ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 397 #endif
 398         } else if (type == NTLM) {
 399                 char ntlm_session_key[CIFS_SESS_KEY_SIZE];
 400
 401                 pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
 402                 pSMB->req_no_secext.CaseInsensitivePasswordLength =
 403                         cpu_to_le16(CIFS_SESS_KEY_SIZE);
 404                 pSMB->req_no_secext.CaseSensitivePasswordLength =
 405                         cpu_to_le16(CIFS_SESS_KEY_SIZE);
 406
 407                 /* calculate session key */
 408                 SMBNTencrypt(ses->password, ses->server->cryptKey,
 409                              ntlm_session_key);
 410
 411                 if(first_time) /* should this be moved into common code
 412                                   with similar ntlmv2 path? */
 413                         cifs_calculate_mac_key(ses->server->mac_signing_key,
 414                                 ntlm_session_key, ses->password);
 415                 /* copy session key */
 416
 417                 memcpy(bcc_ptr, (char *)ntlm_session_key,CIFS_SESS_KEY_SIZE);
 418                 bcc_ptr += CIFS_SESS_KEY_SIZE;
 419                 memcpy(bcc_ptr, (char *)ntlm_session_key,CIFS_SESS_KEY_SIZE);
 420                 bcc_ptr += CIFS_SESS_KEY_SIZE;
 421                 if(ses->capabilities & CAP_UNICODE) {
 422                         /* unicode strings must be word aligned */
 423                         if (iov[0].iov_len % 2) {
 424                                 *bcc_ptr = 0;
 425                                 bcc_ptr++;
 426                         }
 427                         unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
 428                 } else
 429                         ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 430         } else if (type == NTLMv2) {
 431                 char * v2_sess_key =
 432                         kmalloc(sizeof(struct ntlmv2_resp), GFP_KERNEL);
 433
 434                 /* BB FIXME change all users of v2_sess_key to
 435                    struct ntlmv2_resp */
 436
 437                 if(v2_sess_key == NULL) {
 438                         cifs_small_buf_release(smb_buf);
 439                         return -ENOMEM;
 440                 }
 441
 442                 pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
 443
 444                 /* LM2 password would be here if we supported it */
 445                 pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;
 446                 /*      cpu_to_le16(LM2_SESS_KEY_SIZE); */
 447
 448                 pSMB->req_no_secext.CaseSensitivePasswordLength =
 449                         cpu_to_le16(sizeof(struct ntlmv2_resp));
 450
 451                 /* calculate session key */
 452                 setup_ntlmv2_rsp(ses, v2_sess_key, nls_cp);
 453                 if(first_time) /* should this be moved into common code
 454                                   with similar ntlmv2 path? */
 455                 /*   cifs_calculate_ntlmv2_mac_key(ses->server->mac_signing_key,
 456                                 response BB FIXME, v2_sess_key); */
 457
 458                 /* copy session key */
 459
 460         /*      memcpy(bcc_ptr, (char *)ntlm_session_key,LM2_SESS_KEY_SIZE);
 461                 bcc_ptr += LM2_SESS_KEY_SIZE; */
 462                 memcpy(bcc_ptr, (char *)v2_sess_key, sizeof(struct ntlmv2_resp));
 463                 bcc_ptr += sizeof(struct ntlmv2_resp);
 464                 kfree(v2_sess_key);
 465                 if(ses->capabilities & CAP_UNICODE) {
 466                         if(iov[0].iov_len % 2) {
 467                                 *bcc_ptr = 0;
 468                         }       bcc_ptr++;
 469                         unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
 470                 } else
 471                         ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 472         } else /* NTLMSSP or SPNEGO */ {
 473                 pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
 474                 capabilities |= CAP_EXTENDED_SECURITY;
 475                 pSMB->req.Capabilities = cpu_to_le32(capabilities);
 476                 /* BB set password lengths */
 477         }
 478
 479         count = (long) bcc_ptr - (long) str_area;
 480         smb_buf->smb_buf_length += count;
 481
 482         BCC_LE(smb_buf) = cpu_to_le16(count);
 483
 484         iov[1].iov_base = str_area;
 485         iov[1].iov_len = count;
 486         rc = SendReceive2(xid, ses, iov, 2 /* num_iovecs */, &resp_buf_type, 0);
 487         /* SMB request buf freed in SendReceive2 */
 488
 489         cFYI(1,("ssetup rc from sendrecv2 is %d",rc));
 490         if(rc)
 491                 goto ssetup_exit;
 492
 493         pSMB = (SESSION_SETUP_ANDX *)iov[0].iov_base;
 494         smb_buf = (struct smb_hdr *)iov[0].iov_base;
 495
 496         if((smb_buf->WordCount != 3) && (smb_buf->WordCount != 4)) {
 497                 rc = -EIO;
 498                 cERROR(1,("bad word count %d", smb_buf->WordCount));
 499                 goto ssetup_exit;
 500         }
 501         action = le16_to_cpu(pSMB->resp.Action);
 502         if (action & GUEST_LOGIN)
 503                 cFYI(1, ("Guest login")); /* BB mark SesInfo struct? */
 504         ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
 505         cFYI(1, ("UID = %d ", ses->Suid));
 506         /* response can have either 3 or 4 word count - Samba sends 3 */
 507         /* and lanman response is 3 */
 508         bytes_remaining = BCC(smb_buf);
 509         bcc_ptr = pByteArea(smb_buf);
 510
 511         if(smb_buf->WordCount == 4) {
 512                 __u16 blob_len;
 513                 blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
 514                 bcc_ptr += blob_len;
 515                 if(blob_len > bytes_remaining) {
 516                         cERROR(1,("bad security blob length %d", blob_len));
 517                         rc = -EINVAL;
 518                         goto ssetup_exit;
 519                 }
 520                 bytes_remaining -= blob_len;
 521         }
 522
 523         /* BB check if Unicode and decode strings */
 524         if(smb_buf->Flags2 & SMBFLG2_UNICODE)
 525                 rc = decode_unicode_ssetup(&bcc_ptr, bytes_remaining,
 526                                                    ses, nls_cp);
 527         else
 528                 rc = decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,nls_cp);
 529
 530 ssetup_exit:
 531         kfree(str_area);
 532         if(resp_buf_type == CIFS_SMALL_BUFFER) {
 533                 cFYI(1,("ssetup freeing small buf %p", iov[0].iov_base));
 534                 cifs_small_buf_release(iov[0].iov_base);
 535         } else if(resp_buf_type == CIFS_LARGE_BUFFER)
 536                 cifs_buf_release(iov[0].iov_base);
 537
 538         return rc;
 539 }