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         bcc_ptr = str_area;
 376
 377         ses->flags &= ~CIFS_SES_LANMAN;
 378
 379         if (type == LANMAN) {
 380 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 381                 char lnm_session_key[CIFS_SESS_KEY_SIZE];
 382
 383                 /* no capabilities flags in old lanman negotiation */
 384
 385                 pSMB->old_req.PasswordLength = cpu_to_le16(CIFS_SESS_KEY_SIZE);
 386                 /* BB calculate hash with password */
 387                 /* and copy into bcc */
 388
 389                 calc_lanman_hash(ses, lnm_session_key);
 390                 ses->flags |= CIFS_SES_LANMAN;
 391 /* #ifdef CONFIG_CIFS_DEBUG2
 392                 cifs_dump_mem("cryptkey: ",ses->server->cryptKey,
 393                         CIFS_SESS_KEY_SIZE);
 394 #endif */
 395                 memcpy(bcc_ptr, (char *)lnm_session_key, CIFS_SESS_KEY_SIZE);
 396                 bcc_ptr += CIFS_SESS_KEY_SIZE;
 397
 398                 /* can not sign if LANMAN negotiated so no need
 399                 to calculate signing key? but what if server
 400                 changed to do higher than lanman dialect and
 401                 we reconnected would we ever calc signing_key? */
 402
 403                 cFYI(1, ("Negotiating LANMAN setting up strings"));
 404                 /* Unicode not allowed for LANMAN dialects */
 405                 ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 406 #endif
 407         } else if (type == NTLM) {
 408                 char ntlm_session_key[CIFS_SESS_KEY_SIZE];
 409
 410                 pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
 411                 pSMB->req_no_secext.CaseInsensitivePasswordLength =
 412                         cpu_to_le16(CIFS_SESS_KEY_SIZE);
 413                 pSMB->req_no_secext.CaseSensitivePasswordLength =
 414                         cpu_to_le16(CIFS_SESS_KEY_SIZE);
 415
 416                 /* calculate session key */
 417                 SMBNTencrypt(ses->password, ses->server->cryptKey,
 418                              ntlm_session_key);
 419
 420                 if (first_time) /* should this be moved into common code
 421                                   with similar ntlmv2 path? */
 422                         cifs_calculate_mac_key(&ses->server->mac_signing_key,
 423                                 ntlm_session_key, ses->password);
 424                 /* copy session key */
 425
 426                 memcpy(bcc_ptr, (char *)ntlm_session_key, CIFS_SESS_KEY_SIZE);
 427                 bcc_ptr += CIFS_SESS_KEY_SIZE;
 428                 memcpy(bcc_ptr, (char *)ntlm_session_key, CIFS_SESS_KEY_SIZE);
 429                 bcc_ptr += CIFS_SESS_KEY_SIZE;
 430                 if (ses->capabilities & CAP_UNICODE) {
 431                         /* unicode strings must be word aligned */
 432                         if (iov[0].iov_len % 2) {
 433                                 *bcc_ptr = 0;
 434                                 bcc_ptr++;
 435                         }
 436                         unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
 437                 } else
 438                         ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 439         } else if (type == NTLMv2) {
 440                 char *v2_sess_key =
 441                         kmalloc(sizeof(struct ntlmv2_resp), GFP_KERNEL);
 442
 443                 /* BB FIXME change all users of v2_sess_key to
 444                    struct ntlmv2_resp */
 445
 446                 if (v2_sess_key == NULL) {
 447                         cifs_small_buf_release(smb_buf);
 448                         return -ENOMEM;
 449                 }
 450
 451                 pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
 452
 453                 /* LM2 password would be here if we supported it */
 454                 pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;
 455                 /*      cpu_to_le16(LM2_SESS_KEY_SIZE); */
 456
 457                 pSMB->req_no_secext.CaseSensitivePasswordLength =
 458                         cpu_to_le16(sizeof(struct ntlmv2_resp));
 459
 460                 /* calculate session key */
 461                 setup_ntlmv2_rsp(ses, v2_sess_key, nls_cp);
 462                 if (first_time) /* should this be moved into common code
 463                                    with similar ntlmv2 path? */
 464                 /*   cifs_calculate_ntlmv2_mac_key(ses->server->mac_signing_key,
 465                                 response BB FIXME, v2_sess_key); */
 466
 467                 /* copy session key */
 468
 469         /*      memcpy(bcc_ptr, (char *)ntlm_session_key,LM2_SESS_KEY_SIZE);
 470                 bcc_ptr += LM2_SESS_KEY_SIZE; */
 471                 memcpy(bcc_ptr, (char *)v2_sess_key,
 472                        sizeof(struct ntlmv2_resp));
 473                 bcc_ptr += sizeof(struct ntlmv2_resp);
 474                 kfree(v2_sess_key);
 475                 if (ses->capabilities & CAP_UNICODE) {
 476                         if (iov[0].iov_len % 2) {
 477                                 *bcc_ptr = 0;
 478                         }       bcc_ptr++;
 479                         unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
 480                 } else
 481                         ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 482         } else /* NTLMSSP or SPNEGO */ {
 483                 pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
 484                 capabilities |= CAP_EXTENDED_SECURITY;
 485                 pSMB->req.Capabilities = cpu_to_le32(capabilities);
 486                 /* BB set password lengths */
 487         }
 488
 489         count = (long) bcc_ptr - (long) str_area;
 490         smb_buf->smb_buf_length += count;
 491
 492         BCC_LE(smb_buf) = cpu_to_le16(count);
 493
 494         iov[1].iov_base = str_area;
 495         iov[1].iov_len = count;
 496         rc = SendReceive2(xid, ses, iov, 2 /* num_iovecs */, &resp_buf_type, 0);
 497         /* SMB request buf freed in SendReceive2 */
 498
 499         cFYI(1, ("ssetup rc from sendrecv2 is %d", rc));
 500         if (rc)
 501                 goto ssetup_exit;
 502
 503         pSMB = (SESSION_SETUP_ANDX *)iov[0].iov_base;
 504         smb_buf = (struct smb_hdr *)iov[0].iov_base;
 505
 506         if ((smb_buf->WordCount != 3) && (smb_buf->WordCount != 4)) {
 507                 rc = -EIO;
 508                 cERROR(1, ("bad word count %d", smb_buf->WordCount));
 509                 goto ssetup_exit;
 510         }
 511         action = le16_to_cpu(pSMB->resp.Action);
 512         if (action & GUEST_LOGIN)
 513                 cFYI(1, ("Guest login")); /* BB mark SesInfo struct? */
 514         ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
 515         cFYI(1, ("UID = %d ", ses->Suid));
 516         /* response can have either 3 or 4 word count - Samba sends 3 */
 517         /* and lanman response is 3 */
 518         bytes_remaining = BCC(smb_buf);
 519         bcc_ptr = pByteArea(smb_buf);
 520
 521         if (smb_buf->WordCount == 4) {
 522                 __u16 blob_len;
 523                 blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
 524                 bcc_ptr += blob_len;
 525                 if (blob_len > bytes_remaining) {
 526                         cERROR(1, ("bad security blob length %d", blob_len));
 527                         rc = -EINVAL;
 528                         goto ssetup_exit;
 529                 }
 530                 bytes_remaining -= blob_len;
 531         }
 532
 533         /* BB check if Unicode and decode strings */
 534         if (smb_buf->Flags2 & SMBFLG2_UNICODE)
 535                 rc = decode_unicode_ssetup(&bcc_ptr, bytes_remaining,
 536                                                    ses, nls_cp);
 537         else
 538                 rc = decode_ascii_ssetup(&bcc_ptr, bytes_remaining,
 539                                          ses, nls_cp);
 540
 541 ssetup_exit:
 542         kfree(str_area);
 543         if (resp_buf_type == CIFS_SMALL_BUFFER) {
 544                 cFYI(1, ("ssetup freeing small buf %p", iov[0].iov_base));
 545                 cifs_small_buf_release(iov[0].iov_base);
 546         } else if (resp_buf_type == CIFS_LARGE_BUFFER)
 547                 cifs_buf_release(iov[0].iov_base);
 548
 549         return rc;
 550 }