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, system_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, system_utsname.release);
 162         bcc_ptr += strlen(system_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
 272         bcc_ptr += len + 1;
 273         bleft -= len + 1;
 274
 275         len = strnlen(bcc_ptr, bleft);
 276         if(len >= bleft)
 277                 return rc;
 278
 279         if(ses->serverNOS)
 280                 kfree(ses->serverNOS);
 281
 282         ses->serverNOS = kzalloc(len + 1, GFP_KERNEL);
 283         if(ses->serverNOS)
 284                 strncpy(ses->serverNOS, bcc_ptr, len);
 285
 286         bcc_ptr += len + 1;
 287         bleft -= len + 1;
 288
 289         len = strnlen(bcc_ptr, bleft);
 290         if(len > bleft)
 291                 return rc;
 292
 293         if(ses->serverDomain)
 294                 kfree(ses->serverDomain);
 295
 296         ses->serverDomain = kzalloc(len + 1, GFP_KERNEL);
 297         if(ses->serverOS)
 298                 strncpy(ses->serverOS, bcc_ptr, len);
 299
 300         bcc_ptr += len + 1;
 301         bleft -= len + 1;
 302
 303         cFYI(1,("ascii: bytes left %d",bleft));
 304
 305         return rc;
 306 }
 307
 308 int
 309 CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses, int first_time,
 310                 const struct nls_table *nls_cp)
 311 {
 312         int rc = 0;
 313         int wct;
 314         struct smb_hdr *smb_buf;
 315         char *bcc_ptr;
 316         char *str_area;
 317         SESSION_SETUP_ANDX *pSMB;
 318         __u32 capabilities;
 319         int count;
 320         int resp_buf_type = 0;
 321         struct kvec iov[2];
 322         enum securityEnum type;
 323         __u16 action;
 324         int bytes_remaining;
 325
 326         if(ses == NULL)
 327                 return -EINVAL;
 328
 329         type = ses->server->secType;
 330
 331         cFYI(1,("sess setup type %d",type));
 332         if(type == LANMAN) {
 333 #ifndef CONFIG_CIFS_WEAK_PW_HASH
 334                 /* LANMAN and plaintext are less secure and off by default.
 335                 So we make this explicitly be turned on in kconfig (in the
 336                 build) and turned on at runtime (changed from the default)
 337                 in proc/fs/cifs or via mount parm.  Unfortunately this is
 338                 needed for old Win (e.g. Win95), some obscure NAS and OS/2 */
 339                 return -EOPNOTSUPP;
 340 #endif
 341                 wct = 10; /* lanman 2 style sessionsetup */
 342         } else if((type == NTLM) || (type == NTLMv2)) {
 343                 /* For NTLMv2 failures eventually may need to retry NTLM */
 344                 wct = 13; /* old style NTLM sessionsetup */
 345         } else /* same size for negotiate or auth, NTLMSSP or extended security */
 346                 wct = 12;
 347
 348         rc = small_smb_init_no_tc(SMB_COM_SESSION_SETUP_ANDX, wct, ses,
 349                             (void **)&smb_buf);
 350         if(rc)
 351                 return rc;
 352
 353         pSMB = (SESSION_SETUP_ANDX *)smb_buf;
 354
 355         capabilities = cifs_ssetup_hdr(ses, pSMB);
 356
 357         /* we will send the SMB in two pieces,
 358         a fixed length beginning part, and a
 359         second part which will include the strings
 360         and rest of bcc area, in order to avoid having
 361         to do a large buffer 17K allocation */
 362         iov[0].iov_base = (char *)pSMB;
 363         iov[0].iov_len = smb_buf->smb_buf_length + 4;
 364
 365         /* 2000 big enough to fit max user, domain, NOS name etc. */
 366         str_area = kmalloc(2000, GFP_KERNEL);
 367         bcc_ptr = str_area;
 368
 369         if(type == LANMAN) {
 370 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 371                 char lnm_session_key[CIFS_SESS_KEY_SIZE];
 372
 373                 /* no capabilities flags in old lanman negotiation */
 374
 375                 pSMB->old_req.PasswordLength = CIFS_SESS_KEY_SIZE;
 376                 /* BB calculate hash with password */
 377                 /* and copy into bcc */
 378
 379                 calc_lanman_hash(ses, lnm_session_key);
 380
 381 /* #ifdef CONFIG_CIFS_DEBUG2
 382                 cifs_dump_mem("cryptkey: ",ses->server->cryptKey,
 383                         CIFS_SESS_KEY_SIZE);
 384 #endif */
 385                 memcpy(bcc_ptr, (char *)lnm_session_key, CIFS_SESS_KEY_SIZE);
 386                 bcc_ptr += CIFS_SESS_KEY_SIZE;
 387
 388                 /* can not sign if LANMAN negotiated so no need
 389                 to calculate signing key? but what if server
 390                 changed to do higher than lanman dialect and
 391                 we reconnected would we ever calc signing_key? */
 392
 393                 cFYI(1,("Negotiating LANMAN setting up strings"));
 394                 /* Unicode not allowed for LANMAN dialects */
 395                 ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 396 #endif
 397         } else if (type == NTLM) {
 398                 char ntlm_session_key[CIFS_SESS_KEY_SIZE];
 399
 400                 pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
 401                 pSMB->req_no_secext.CaseInsensitivePasswordLength =
 402                         cpu_to_le16(CIFS_SESS_KEY_SIZE);
 403                 pSMB->req_no_secext.CaseSensitivePasswordLength =
 404                         cpu_to_le16(CIFS_SESS_KEY_SIZE);
 405
 406                 /* calculate session key */
 407                 SMBNTencrypt(ses->password, ses->server->cryptKey,
 408                              ntlm_session_key);
 409
 410                 if(first_time) /* should this be moved into common code
 411                                   with similar ntlmv2 path? */
 412                         cifs_calculate_mac_key(ses->server->mac_signing_key,
 413                                 ntlm_session_key, ses->password);
 414                 /* copy session key */
 415
 416                 memcpy(bcc_ptr, (char *)ntlm_session_key,CIFS_SESS_KEY_SIZE);
 417                 bcc_ptr += CIFS_SESS_KEY_SIZE;
 418                 memcpy(bcc_ptr, (char *)ntlm_session_key,CIFS_SESS_KEY_SIZE);
 419                 bcc_ptr += CIFS_SESS_KEY_SIZE;
 420                 if(ses->capabilities & CAP_UNICODE) {
 421                         /* unicode strings must be word aligned */
 422                         if (iov[0].iov_len % 2) {
 423                                 *bcc_ptr = 0;
 424                                 bcc_ptr++;
 425                         }
 426                         unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
 427                 } else
 428                         ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 429         } else if (type == NTLMv2) {
 430                 char * v2_sess_key =
 431                         kmalloc(sizeof(struct ntlmv2_resp), GFP_KERNEL);
 432
 433                 /* BB FIXME change all users of v2_sess_key to
 434                    struct ntlmv2_resp */
 435
 436                 if(v2_sess_key == NULL) {
 437                         cifs_small_buf_release(smb_buf);
 438                         return -ENOMEM;
 439                 }
 440
 441                 pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
 442
 443                 /* LM2 password would be here if we supported it */
 444                 pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;
 445                 /*      cpu_to_le16(LM2_SESS_KEY_SIZE); */
 446
 447                 pSMB->req_no_secext.CaseSensitivePasswordLength =
 448                         cpu_to_le16(sizeof(struct ntlmv2_resp));
 449
 450                 /* calculate session key */
 451                 setup_ntlmv2_rsp(ses, v2_sess_key, nls_cp);
 452                 if(first_time) /* should this be moved into common code
 453                                   with similar ntlmv2 path? */
 454                 /*   cifs_calculate_ntlmv2_mac_key(ses->server->mac_signing_key,
 455                                 response BB FIXME, v2_sess_key); */
 456
 457                 /* copy session key */
 458
 459         /*      memcpy(bcc_ptr, (char *)ntlm_session_key,LM2_SESS_KEY_SIZE);
 460                 bcc_ptr += LM2_SESS_KEY_SIZE; */
 461                 memcpy(bcc_ptr, (char *)v2_sess_key, sizeof(struct ntlmv2_resp));
 462                 bcc_ptr += sizeof(struct ntlmv2_resp);
 463                 kfree(v2_sess_key);
 464                 if(ses->capabilities & CAP_UNICODE) {
 465                         if(iov[0].iov_len % 2) {
 466                                 *bcc_ptr = 0;
 467                         }       bcc_ptr++;
 468                         unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
 469                 } else
 470                         ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
 471         } else /* NTLMSSP or SPNEGO */ {
 472                 pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
 473                 capabilities |= CAP_EXTENDED_SECURITY;
 474                 pSMB->req.Capabilities = cpu_to_le32(capabilities);
 475                 /* BB set password lengths */
 476         }
 477
 478         count = (long) bcc_ptr - (long) str_area;
 479         smb_buf->smb_buf_length += count;
 480
 481         BCC_LE(smb_buf) = cpu_to_le16(count);
 482
 483         iov[1].iov_base = str_area;
 484         iov[1].iov_len = count;
 485         rc = SendReceive2(xid, ses, iov, 2 /* num_iovecs */, &resp_buf_type, 0);
 486         /* SMB request buf freed in SendReceive2 */
 487
 488         cFYI(1,("ssetup rc from sendrecv2 is %d",rc));
 489         if(rc)
 490                 goto ssetup_exit;
 491
 492         pSMB = (SESSION_SETUP_ANDX *)iov[0].iov_base;
 493         smb_buf = (struct smb_hdr *)iov[0].iov_base;
 494
 495         if((smb_buf->WordCount != 3) && (smb_buf->WordCount != 4)) {
 496                 rc = -EIO;
 497                 cERROR(1,("bad word count %d", smb_buf->WordCount));
 498                 goto ssetup_exit;
 499         }
 500         action = le16_to_cpu(pSMB->resp.Action);
 501         if (action & GUEST_LOGIN)
 502                 cFYI(1, ("Guest login")); /* BB mark SesInfo struct? */
 503         ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
 504         cFYI(1, ("UID = %d ", ses->Suid));
 505         /* response can have either 3 or 4 word count - Samba sends 3 */
 506         /* and lanman response is 3 */
 507         bytes_remaining = BCC(smb_buf);
 508         bcc_ptr = pByteArea(smb_buf);
 509
 510         if(smb_buf->WordCount == 4) {
 511                 __u16 blob_len;
 512                 blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
 513                 bcc_ptr += blob_len;
 514                 if(blob_len > bytes_remaining) {
 515                         cERROR(1,("bad security blob length %d", blob_len));
 516                         rc = -EINVAL;
 517                         goto ssetup_exit;
 518                 }
 519                 bytes_remaining -= blob_len;
 520         }
 521
 522         /* BB check if Unicode and decode strings */
 523         if(smb_buf->Flags2 & SMBFLG2_UNICODE)
 524                 rc = decode_unicode_ssetup(&bcc_ptr, bytes_remaining,
 525                                                    ses, nls_cp);
 526         else
 527                 rc = decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,nls_cp);
 528
 529 ssetup_exit:
 530         kfree(str_area);
 531         if(resp_buf_type == CIFS_SMALL_BUFFER) {
 532                 cFYI(1,("ssetup freeing small buf %p", iov[0].iov_base));
 533                 cifs_small_buf_release(iov[0].iov_base);
 534         } else if(resp_buf_type == CIFS_LARGE_BUFFER)
 535                 cifs_buf_release(iov[0].iov_base);
 536
 537         return rc;
 538 }