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, 2007
   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 &
  55             (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
  56                 pSMB->req.hdr.Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
  57
  58         if (ses->capabilities & CAP_UNICODE) {
  59                 pSMB->req.hdr.Flags2 |= SMBFLG2_UNICODE;
  60                 capabilities |= CAP_UNICODE;
  61         }
  62         if (ses->capabilities & CAP_STATUS32) {
  63                 pSMB->req.hdr.Flags2 |= SMBFLG2_ERR_STATUS;
  64                 capabilities |= CAP_STATUS32;
  65         }
  66         if (ses->capabilities & CAP_DFS) {
  67                 pSMB->req.hdr.Flags2 |= SMBFLG2_DFS;
  68                 capabilities |= CAP_DFS;
  69         }
  70         if (ses->capabilities & CAP_UNIX) {
  71                 capabilities |= CAP_UNIX;
  72         }
  73
  74         /* BB check whether to init vcnum BB */
  75         return capabilities;
  76 }
  77
  78 static void unicode_ssetup_strings(char **pbcc_area, struct cifsSesInfo *ses,
  79                                    const struct nls_table *nls_cp)
  80 {
  81         char *bcc_ptr = *pbcc_area;
  82         int bytes_ret = 0;
  83
  84         /* BB FIXME add check that strings total less
  85         than 335 or will need to send them as arrays */
  86
  87         /* unicode strings, must be word aligned before the call */
  88 /*      if ((long) bcc_ptr % 2) {
  89                 *bcc_ptr = 0;
  90                 bcc_ptr++;
  91         } */
  92         /* copy user */
  93         if (ses->userName == NULL) {
  94                 /* null user mount */
  95                 *bcc_ptr = 0;
  96                 *(bcc_ptr+1) = 0;
  97         } else { /* 300 should be long enough for any conceivable user name */
  98                 bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, ses->userName,
  99                                           300, nls_cp);
 100         }
 101         bcc_ptr += 2 * bytes_ret;
 102         bcc_ptr += 2; /* account for null termination */
 103         /* copy domain */
 104         if (ses->domainName == NULL) {
 105                 /* Sending null domain better than using a bogus domain name (as
 106                 we did briefly in 2.6.18) since server will use its default */
 107                 *bcc_ptr = 0;
 108                 *(bcc_ptr+1) = 0;
 109                 bytes_ret = 0;
 110         } else
 111                 bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, ses->domainName,
 112                                           256, nls_cp);
 113         bcc_ptr += 2 * bytes_ret;
 114         bcc_ptr += 2;  /* account for null terminator */
 115
 116         /* Copy OS version */
 117         bytes_ret = cifs_strtoUCS((__le16 *)bcc_ptr, "Linux version ", 32,
 118                                   nls_cp);
 119         bcc_ptr += 2 * bytes_ret;
 120         bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, init_utsname()->release,
 121                                   32, nls_cp);
 122         bcc_ptr += 2 * bytes_ret;
 123         bcc_ptr += 2; /* trailing null */
 124
 125         bytes_ret = cifs_strtoUCS((__le16 *) bcc_ptr, CIFS_NETWORK_OPSYS,
 126                                   32, nls_cp);
 127         bcc_ptr += 2 * bytes_ret;
 128         bcc_ptr += 2; /* trailing null */
 129
 130         *pbcc_area = bcc_ptr;
 131 }
 132
 133 static void ascii_ssetup_strings(char **pbcc_area, struct cifsSesInfo *ses,
 134                                  const struct nls_table *nls_cp)
 135 {
 136         char *bcc_ptr = *pbcc_area;
 137
 138         /* copy user */
 139         /* BB what about null user mounts - check that we do this BB */
 140         /* copy user */
 141         if (ses->userName == NULL) {
 142                 /* BB what about null user mounts - check that we do this BB */
 143         } else { /* 300 should be long enough for any conceivable user name */
 144                 strncpy(bcc_ptr, ses->userName, 300);
 145         }
 146         /* BB improve check for overflow */
 147         bcc_ptr += strnlen(ses->userName, 300);
 148         *bcc_ptr = 0;
 149         bcc_ptr++; /* account for null termination */
 150
 151         /* copy domain */
 152
 153         if (ses->domainName != NULL) {
 154                 strncpy(bcc_ptr, ses->domainName, 256);
 155                 bcc_ptr += strnlen(ses->domainName, 256);
 156         } /* else we will send a null domain name
 157              so the server will default to its own domain */
 158         *bcc_ptr = 0;
 159         bcc_ptr++;
 160
 161         /* BB check for overflow here */
 162
 163         strcpy(bcc_ptr, "Linux version ");
 164         bcc_ptr += strlen("Linux version ");
 165         strcpy(bcc_ptr, init_utsname()->release);
 166         bcc_ptr += strlen(init_utsname()->release) + 1;
 167
 168         strcpy(bcc_ptr, CIFS_NETWORK_OPSYS);
 169         bcc_ptr += strlen(CIFS_NETWORK_OPSYS) + 1;
 170
 171         *pbcc_area = bcc_ptr;
 172 }
 173
 174 static int decode_unicode_ssetup(char **pbcc_area, int bleft,
 175                                  struct cifsSesInfo *ses,
 176                                  const struct nls_table *nls_cp)
 177 {
 178         int rc = 0;
 179         int words_left, len;
 180         char *data = *pbcc_area;
 181
 182
 183
 184         cFYI(1, ("bleft %d", bleft));
 185
 186
 187         /* SMB header is unaligned, so cifs servers word align start of
 188            Unicode strings */
 189         data++;
 190         bleft--; /* Windows servers do not always double null terminate
 191                     their final Unicode string - in which case we
 192                     now will not attempt to decode the byte of junk
 193                     which follows it */
 194
 195         words_left = bleft / 2;
 196
 197         /* save off server operating system */
 198         len = UniStrnlen((wchar_t *) data, words_left);
 199
 200 /* We look for obvious messed up bcc or strings in response so we do not go off
 201    the end since (at least) WIN2K and Windows XP have a major bug in not null
 202    terminating last Unicode string in response  */
 203         if (len >= words_left)
 204                 return rc;
 205
 206         if (ses->serverOS)
 207                 kfree(ses->serverOS);
 208         /* UTF-8 string will not grow more than four times as big as UCS-16 */
 209         ses->serverOS = kzalloc(4 * len, GFP_KERNEL);
 210         if (ses->serverOS != NULL) {
 211                 cifs_strfromUCS_le(ses->serverOS, (__le16 *)data, len,
 212                                    nls_cp);
 213         }
 214         data += 2 * (len + 1);
 215         words_left -= len + 1;
 216
 217         /* save off server network operating system */
 218         len = UniStrnlen((wchar_t *) data, words_left);
 219
 220         if (len >= words_left)
 221                 return rc;
 222
 223         if (ses->serverNOS)
 224                 kfree(ses->serverNOS);
 225         ses->serverNOS = kzalloc(4 * len, GFP_KERNEL); /* BB this is wrong length FIXME BB */
 226         if (ses->serverNOS != NULL) {
 227                 cifs_strfromUCS_le(ses->serverNOS, (__le16 *)data, len,
 228                                    nls_cp);
 229                 if (strncmp(ses->serverNOS, "NT LAN Manager 4", 16) == 0) {
 230                         cFYI(1, ("NT4 server"));
 231                         ses->flags |= CIFS_SES_NT4;
 232                 }
 233         }
 234         data += 2 * (len + 1);
 235         words_left -= len + 1;
 236
 237         /* save off server domain */
 238         len = UniStrnlen((wchar_t *) data, words_left);
 239
 240         if (len > words_left)
 241                 return rc;
 242
 243         if (ses->serverDomain)
 244                 kfree(ses->serverDomain);
 245         ses->serverDomain = kzalloc(2 * (len + 1), GFP_KERNEL); /* BB FIXME wrong length */
 246         if (ses->serverDomain != NULL) {
 247                 cifs_strfromUCS_le(ses->serverDomain, (__le16 *)data, len,
 248                                    nls_cp);
 249                 ses->serverDomain[2*len] = 0;
 250                 ses->serverDomain[(2*len) + 1] = 0;
 251         }
 252         data += 2 * (len + 1);
 253         words_left -= len + 1;
 254
 255         cFYI(1, ("words left: %d", words_left));
 256
 257         return rc;
 258 }
 259
 260 static int decode_ascii_ssetup(char **pbcc_area, int bleft,
 261                                struct cifsSesInfo *ses,
 262                                const struct nls_table *nls_cp)
 263 {
 264         int rc = 0;
 265         int len;
 266         char *bcc_ptr = *pbcc_area;
 267
 268         cFYI(1, ("decode sessetup ascii. bleft %d", bleft));
 269
 270         len = strnlen(bcc_ptr, bleft);
 271         if (len >= bleft)
 272                 return rc;
 273
 274         if (ses->serverOS)
 275                 kfree(ses->serverOS);
 276
 277         ses->serverOS = kzalloc(len + 1, GFP_KERNEL);
 278         if (ses->serverOS)
 279                 strncpy(ses->serverOS, bcc_ptr, len);
 280         if (strncmp(ses->serverOS, "OS/2", 4) == 0) {
 281                         cFYI(1, ("OS/2 server"));
 282                         ses->flags |= CIFS_SES_OS2;
 283         }
 284
 285         bcc_ptr += len + 1;
 286         bleft -= len + 1;
 287
 288         len = strnlen(bcc_ptr, bleft);
 289         if (len >= bleft)
 290                 return rc;
 291
 292         if (ses->serverNOS)
 293                 kfree(ses->serverNOS);
 294
 295         ses->serverNOS = kzalloc(len + 1, GFP_KERNEL);
 296         if (ses->serverNOS)
 297                 strncpy(ses->serverNOS, bcc_ptr, len);
 298
 299         bcc_ptr += len + 1;
 300         bleft -= len + 1;
 301
 302         len = strnlen(bcc_ptr, bleft);
 303         if (len > bleft)
 304                 return rc;
 305
 306         /* No domain field in LANMAN case. Domain is
 307            returned by old servers in the SMB negprot response */
 308         /* BB For newer servers which do not support Unicode,
 309            but thus do return domain here we could add parsing
 310            for it later, but it is not very important */
 311         cFYI(1, ("ascii: bytes left %d", bleft));
 312
 313         return rc;
 314 }
 315
 316 int
 317 CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses, int first_time,
 318                 const struct nls_table *nls_cp)
 319 {
 320         int rc = 0;
 321         int wct;
 322         struct smb_hdr *smb_buf;
 323         char *bcc_ptr;
 324         char *str_area;
 325         SESSION_SETUP_ANDX *pSMB;
 326         __u32 capabilities;
 327         int count;
 328         int resp_buf_type = 0;
 329         struct kvec iov[2];
 330         enum securityEnum type;
 331         __u16 action;
 332         int bytes_remaining;
 333
 334         if (ses == NULL)
 335                 return -EINVAL;
 336
 337         type = ses->server->secType;
 338
 339         cFYI(1, ("sess setup type %d", type));
 340         if (type == LANMAN) {
 341 #ifndef CONFIG_CIFS_WEAK_PW_HASH
 342                 /* LANMAN and plaintext are less secure and off by default.
 343                 So we make this explicitly be turned on in kconfig (in the
 344                 build) and turned on at runtime (changed from the default)
 345                 in proc/fs/cifs or via mount parm.  Unfortunately this is
 346                 needed for old Win (e.g. Win95), some obscure NAS and OS/2 */
 347                 return -EOPNOTSUPP;
 348 #endif
 349                 wct = 10; /* lanman 2 style sessionsetup */
 350         } else if ((type == NTLM) || (type == NTLMv2)) {
 351                 /* For NTLMv2 failures eventually may need to retry NTLM */
 352                 wct = 13; /* old style NTLM sessionsetup */
 353         } else /* same size: negotiate or auth, NTLMSSP or extended security */
 354                 wct = 12;
 355
 356         rc = small_smb_init_no_tc(SMB_COM_SESSION_SETUP_ANDX, wct, ses,
 357                             (void **)&smb_buf);
 358         if (rc)
 359                 return rc;
 360
 361         pSMB = (SESSION_SETUP_ANDX *)smb_buf;
 362
 363         capabilities = cifs_ssetup_hdr(ses, pSMB);
 364
 365         /* we will send the SMB in two pieces,
 366         a fixed length beginning part, and a
 367         second part which will include the strings
 368         and rest of bcc area, in order to avoid having
 369         to do a large buffer 17K allocation */
 370         iov[0].iov_base = (char *)pSMB;
 371         iov[0].iov_len = smb_buf->smb_buf_length + 4;
 372
 373         /* 2000 big enough to fit max user, domain, NOS name etc. */
 374         str_area = kmalloc(2000, GFP_KERNEL);
 375         if (str_area == NULL) {
 376                 cifs_small_buf_release(smb_buf);
 377                 return -ENOMEM;
 378         }
 379         bcc_ptr = str_area;
 380
 381         ses->flags &= ~CIFS_SES_LANMAN;
 382
 383         if (type == LANMAN) {
 384 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 385                 char lnm_session_key[CIFS_SESS_KEY_SIZE];
 386
 387                 /* no capabilities flags in old lanman negotiation */
 388
 389                 pSMB->old_req.PasswordLength = cpu_to_le16(CIFS_SESS_KEY_SIZE);
 390                 /* BB calculate hash with password */
 391                 /* and copy into bcc */
 392
 393                 calc_lanman_hash(ses, lnm_session_key);
 394                 ses->flags |= CIFS_SES_LANMAN;
 395 /* #ifdef CONFIG_CIFS_DEBUG2
 396                 cifs_dump_mem("cryptkey: ",ses->server->cryptKey,
 397                         CIFS_SESS_KEY_SIZE);
 398 #endif */
 399                 memcpy(bcc_ptr, (char *)lnm_session_key, CIFS_SESS_KEY_SIZE);
 400                 bcc_ptr += CIFS_SESS_KEY_SIZE;
 401
 402                 /* can not sign if LANMAN negotiated so no need
 403                 to calculate signing key? but what if server
 404                 changed to do higher than lanman dialect and
 405                 we reconnected would we ever calc signing_key? */
 406
 407                 cFYI(1, ("Negotiating LANMAN setting up strings"));
 408                 /* Unicode not allowed for LANMAN dialects */
 409                 ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 410 #endif
 411         } else if (type == NTLM) {
 412                 char ntlm_session_key[CIFS_SESS_KEY_SIZE];
 413
 414                 pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
 415                 pSMB->req_no_secext.CaseInsensitivePasswordLength =
 416                         cpu_to_le16(CIFS_SESS_KEY_SIZE);
 417                 pSMB->req_no_secext.CaseSensitivePasswordLength =
 418                         cpu_to_le16(CIFS_SESS_KEY_SIZE);
 419
 420                 /* calculate session key */
 421                 SMBNTencrypt(ses->password, ses->server->cryptKey,
 422                              ntlm_session_key);
 423
 424                 if (first_time) /* should this be moved into common code
 425                                   with similar ntlmv2 path? */
 426                         cifs_calculate_mac_key(&ses->server->mac_signing_key,
 427                                 ntlm_session_key, ses->password);
 428                 /* copy session key */
 429
 430                 memcpy(bcc_ptr, (char *)ntlm_session_key, CIFS_SESS_KEY_SIZE);
 431                 bcc_ptr += CIFS_SESS_KEY_SIZE;
 432                 memcpy(bcc_ptr, (char *)ntlm_session_key, CIFS_SESS_KEY_SIZE);
 433                 bcc_ptr += CIFS_SESS_KEY_SIZE;
 434                 if (ses->capabilities & CAP_UNICODE) {
 435                         /* unicode strings must be word aligned */
 436                         if (iov[0].iov_len % 2) {
 437                                 *bcc_ptr = 0;
 438                                 bcc_ptr++;
 439                         }
 440                         unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
 441                 } else
 442                         ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 443         } else if (type == NTLMv2) {
 444                 char *v2_sess_key =
 445                         kmalloc(sizeof(struct ntlmv2_resp), GFP_KERNEL);
 446
 447                 /* BB FIXME change all users of v2_sess_key to
 448                    struct ntlmv2_resp */
 449
 450                 if (v2_sess_key == NULL) {
 451                         cifs_small_buf_release(smb_buf);
 452                         return -ENOMEM;
 453                 }
 454
 455                 pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
 456
 457                 /* LM2 password would be here if we supported it */
 458                 pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;
 459                 /*      cpu_to_le16(LM2_SESS_KEY_SIZE); */
 460
 461                 pSMB->req_no_secext.CaseSensitivePasswordLength =
 462                         cpu_to_le16(sizeof(struct ntlmv2_resp));
 463
 464                 /* calculate session key */
 465                 setup_ntlmv2_rsp(ses, v2_sess_key, nls_cp);
 466                 if (first_time) /* should this be moved into common code
 467                                    with similar ntlmv2 path? */
 468                 /*   cifs_calculate_ntlmv2_mac_key(ses->server->mac_signing_key,
 469                                 response BB FIXME, v2_sess_key); */
 470
 471                 /* copy session key */
 472
 473         /*      memcpy(bcc_ptr, (char *)ntlm_session_key,LM2_SESS_KEY_SIZE);
 474                 bcc_ptr += LM2_SESS_KEY_SIZE; */
 475                 memcpy(bcc_ptr, (char *)v2_sess_key,
 476                        sizeof(struct ntlmv2_resp));
 477                 bcc_ptr += sizeof(struct ntlmv2_resp);
 478                 kfree(v2_sess_key);
 479                 if (ses->capabilities & CAP_UNICODE) {
 480                         if (iov[0].iov_len % 2) {
 481                                 *bcc_ptr = 0;
 482                         }       bcc_ptr++;
 483                         unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
 484                 } else
 485                         ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 486         } else /* NTLMSSP or SPNEGO */ {
 487                 pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
 488                 capabilities |= CAP_EXTENDED_SECURITY;
 489                 pSMB->req.Capabilities = cpu_to_le32(capabilities);
 490                 /* BB set password lengths */
 491         }
 492
 493         count = (long) bcc_ptr - (long) str_area;
 494         smb_buf->smb_buf_length += count;
 495
 496         BCC_LE(smb_buf) = cpu_to_le16(count);
 497
 498         iov[1].iov_base = str_area;
 499         iov[1].iov_len = count;
 500         rc = SendReceive2(xid, ses, iov, 2 /* num_iovecs */, &resp_buf_type, 0);
 501         /* SMB request buf freed in SendReceive2 */
 502
 503         cFYI(1, ("ssetup rc from sendrecv2 is %d", rc));
 504         if (rc)
 505                 goto ssetup_exit;
 506
 507         pSMB = (SESSION_SETUP_ANDX *)iov[0].iov_base;
 508         smb_buf = (struct smb_hdr *)iov[0].iov_base;
 509
 510         if ((smb_buf->WordCount != 3) && (smb_buf->WordCount != 4)) {
 511                 rc = -EIO;
 512                 cERROR(1, ("bad word count %d", smb_buf->WordCount));
 513                 goto ssetup_exit;
 514         }
 515         action = le16_to_cpu(pSMB->resp.Action);
 516         if (action & GUEST_LOGIN)
 517                 cFYI(1, ("Guest login")); /* BB mark SesInfo struct? */
 518         ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
 519         cFYI(1, ("UID = %d ", ses->Suid));
 520         /* response can have either 3 or 4 word count - Samba sends 3 */
 521         /* and lanman response is 3 */
 522         bytes_remaining = BCC(smb_buf);
 523         bcc_ptr = pByteArea(smb_buf);
 524
 525         if (smb_buf->WordCount == 4) {
 526                 __u16 blob_len;
 527                 blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
 528                 bcc_ptr += blob_len;
 529                 if (blob_len > bytes_remaining) {
 530                         cERROR(1, ("bad security blob length %d", blob_len));
 531                         rc = -EINVAL;
 532                         goto ssetup_exit;
 533                 }
 534                 bytes_remaining -= blob_len;
 535         }
 536
 537         /* BB check if Unicode and decode strings */
 538         if (smb_buf->Flags2 & SMBFLG2_UNICODE)
 539                 rc = decode_unicode_ssetup(&bcc_ptr, bytes_remaining,
 540                                                    ses, nls_cp);
 541         else
 542                 rc = decode_ascii_ssetup(&bcc_ptr, bytes_remaining,
 543                                          ses, nls_cp);
 544
 545 ssetup_exit:
 546         kfree(str_area);
 547         if (resp_buf_type == CIFS_SMALL_BUFFER) {
 548                 cFYI(1, ("ssetup freeing small buf %p", iov[0].iov_base));
 549                 cifs_small_buf_release(iov[0].iov_base);
 550         } else if (resp_buf_type == CIFS_LARGE_BUFFER)
 551                 cifs_buf_release(iov[0].iov_base);
 552
 553         return rc;
 554 }