1 // SPDX-License-Identifier: LGPL-2.1 2 /* 3 * 4 * Copyright (C) International Business Machines Corp., 2002, 2011 5 * Author(s): Steve French (sfrench@us.ibm.com), 6 * Pavel Shilovsky ((pshilovsky@samba.org) 2012 7 * 8 */ 9 #include <linux/fs.h> 10 #include <linux/filelock.h> 11 #include <linux/stat.h> 12 #include <linux/slab.h> 13 #include <linux/pagemap.h> 14 #include <asm/div64.h> 15 #include "cifsfs.h" 16 #include "cifsglob.h" 17 #include "cifsproto.h" 18 #include "cifs_debug.h" 19 #include "cifs_fs_sb.h" 20 #include "cifs_unicode.h" 21 #include "fscache.h" 22 #include "smb2proto.h" 23 #include "../common/smb2status.h" 24 #include "../common/smbfsctl.h" 25 26 static struct smb2_symlink_err_rsp *symlink_data(const struct kvec *iov) 27 { 28 struct smb2_err_rsp *err = iov->iov_base; 29 struct smb2_symlink_err_rsp *sym = ERR_PTR(-EINVAL); 30 u8 *end = (u8 *)err + iov->iov_len; 31 u32 len; 32 33 if (err->ErrorContextCount) { 34 struct smb2_error_context_rsp *p; 35 36 len = (u32)err->ErrorContextCount * (offsetof(struct smb2_error_context_rsp, 37 ErrorContextData) + 38 sizeof(struct smb2_symlink_err_rsp)); 39 if (le32_to_cpu(err->ByteCount) < len || iov->iov_len < len + sizeof(*err) + 1) 40 return ERR_PTR(-EINVAL); 41 42 p = (struct smb2_error_context_rsp *)err->ErrorData; 43 while ((u8 *)p + sizeof(*p) <= end) { 44 if (le32_to_cpu(p->ErrorId) == SMB2_ERROR_ID_DEFAULT) { 45 sym = (struct smb2_symlink_err_rsp *)p->ErrorContextData; 46 break; 47 } 48 cifs_dbg(FYI, "%s: skipping unhandled error context: 0x%x\n", 49 __func__, le32_to_cpu(p->ErrorId)); 50 51 len = ALIGN(le32_to_cpu(p->ErrorDataLength), 8); 52 if (len > end - ((u8 *)p + sizeof(*p))) 53 return ERR_PTR(-EINVAL); 54 55 p = (struct smb2_error_context_rsp *)(p->ErrorContextData + len); 56 } 57 } else if (le32_to_cpu(err->ByteCount) >= sizeof(*sym) && 58 iov->iov_len >= SMB2_SYMLINK_STRUCT_SIZE) { 59 sym = (struct smb2_symlink_err_rsp *)err->ErrorData; 60 } 61 62 if (!IS_ERR(sym) && 63 ((u8 *)sym + sizeof(*sym) > end || 64 le32_to_cpu(sym->SymLinkErrorTag) != SYMLINK_ERROR_TAG || 65 le32_to_cpu(sym->ReparseTag) != IO_REPARSE_TAG_SYMLINK)) 66 sym = ERR_PTR(-EINVAL); 67 68 return sym; 69 } 70 71 int smb2_fix_symlink_target_type(char **target, bool directory, struct cifs_sb_info *cifs_sb) 72 { 73 char *buf; 74 int len; 75 76 /* 77 * POSIX server does not distinguish between symlinks to file and 78 * symlink directory. So nothing is needed to fix on the client side. 79 */ 80 if (cifs_sb_flags(cifs_sb) & CIFS_MOUNT_POSIX_PATHS) 81 return 0; 82 83 if (!*target) 84 return smb_EIO(smb_eio_trace_null_pointers); 85 86 len = strlen(*target); 87 if (!len) 88 return smb_EIO1(smb_eio_trace_sym_target_len, len); 89 90 /* 91 * If this is directory symlink and it does not have trailing slash then 92 * append it. Trailing slash simulates Windows/SMB behavior which do not 93 * allow resolving directory symlink to file. 94 */ 95 if (directory && (*target)[len-1] != '/') { 96 buf = krealloc(*target, len+2, GFP_KERNEL); 97 if (!buf) 98 return -ENOMEM; 99 buf[len] = '/'; 100 buf[len+1] = '\0'; 101 *target = buf; 102 len++; 103 } 104 105 /* 106 * If this is a file (non-directory) symlink and it points to path name 107 * with trailing slash then this is an invalid symlink because file name 108 * cannot contain slash character. File name with slash is invalid on 109 * both Windows and Linux systems. So return an error for such symlink. 110 */ 111 if (!directory && (*target)[len-1] == '/') 112 return smb_EIO(smb_eio_trace_sym_slash); 113 114 return 0; 115 } 116 117 int smb2_parse_symlink_response(struct cifs_sb_info *cifs_sb, const struct kvec *iov, 118 const char *full_path, char **path) 119 { 120 struct smb2_symlink_err_rsp *sym; 121 unsigned int sub_offs, sub_len; 122 unsigned int print_offs, print_len; 123 124 if (!cifs_sb || !iov || !iov->iov_base || !iov->iov_len || !path) 125 return -EINVAL; 126 127 sym = symlink_data(iov); 128 if (IS_ERR(sym)) 129 return PTR_ERR(sym); 130 131 sub_len = le16_to_cpu(sym->SubstituteNameLength); 132 sub_offs = le16_to_cpu(sym->SubstituteNameOffset); 133 print_len = le16_to_cpu(sym->PrintNameLength); 134 print_offs = le16_to_cpu(sym->PrintNameOffset); 135 136 if ((char *)sym->PathBuffer + sub_offs + sub_len > 137 (char *)iov->iov_base + iov->iov_len || 138 (char *)sym->PathBuffer + print_offs + print_len > 139 (char *)iov->iov_base + iov->iov_len) 140 return -EINVAL; 141 142 return smb2_parse_native_symlink(path, 143 (char *)sym->PathBuffer + sub_offs, 144 sub_len, 145 le32_to_cpu(sym->Flags) & SYMLINK_FLAG_RELATIVE, 146 full_path, 147 cifs_sb); 148 } 149 150 int smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms, 151 __u32 *oplock, void *buf) 152 { 153 int rc; 154 __le16 *smb2_path; 155 __u8 smb2_oplock; 156 struct cifs_open_info_data *data = buf; 157 struct smb2_file_all_info file_info = {}; 158 struct smb2_file_all_info *smb2_data = data ? &file_info : NULL; 159 struct kvec err_iov = {}; 160 int err_buftype = CIFS_NO_BUFFER; 161 struct cifs_fid *fid = oparms->fid; 162 struct network_resiliency_req nr_ioctl_req; 163 bool retry_without_read_attributes = false; 164 165 smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb); 166 if (smb2_path == NULL) 167 return -ENOMEM; 168 169 /* 170 * GENERIC_READ, GENERIC_EXECUTE, GENERIC_ALL and MAXIMUM_ALLOWED 171 * contains also FILE_READ_ATTRIBUTES access right. So do not append 172 * FILE_READ_ATTRIBUTES when not needed and prevent calling code path 173 * for retry_without_read_attributes. 174 */ 175 if (!(oparms->desired_access & FILE_READ_ATTRIBUTES) && 176 !(oparms->desired_access & GENERIC_READ) && 177 !(oparms->desired_access & GENERIC_EXECUTE) && 178 !(oparms->desired_access & GENERIC_ALL) && 179 !(oparms->desired_access & MAXIMUM_ALLOWED)) { 180 oparms->desired_access |= FILE_READ_ATTRIBUTES; 181 retry_without_read_attributes = true; 182 } 183 smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH; 184 185 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov, 186 &err_buftype); 187 if (rc == -EACCES && retry_without_read_attributes) { 188 free_rsp_buf(err_buftype, err_iov.iov_base); 189 memset(&err_iov, 0, sizeof(err_iov)); 190 err_buftype = CIFS_NO_BUFFER; 191 oparms->desired_access &= ~FILE_READ_ATTRIBUTES; 192 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov, 193 &err_buftype); 194 } 195 if (rc && data) { 196 struct smb2_hdr *hdr = err_iov.iov_base; 197 198 if (unlikely(!err_iov.iov_base || err_buftype == CIFS_NO_BUFFER)) 199 goto out; 200 if (hdr->Status == STATUS_STOPPED_ON_SYMLINK) { 201 rc = smb2_parse_symlink_response(oparms->cifs_sb, &err_iov, 202 oparms->path, 203 &data->symlink_target); 204 if (!rc) { 205 memset(smb2_data, 0, sizeof(*smb2_data)); 206 oparms->create_options |= OPEN_REPARSE_POINT; 207 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, 208 NULL, NULL, NULL); 209 oparms->create_options &= ~OPEN_REPARSE_POINT; 210 } 211 if (!rc) { 212 bool directory = le32_to_cpu(data->fi.Attributes) & ATTR_DIRECTORY; 213 rc = smb2_fix_symlink_target_type(&data->symlink_target, 214 directory, oparms->cifs_sb); 215 } 216 } 217 } 218 219 if (rc) 220 goto out; 221 222 if (oparms->tcon->use_resilient) { 223 /* default timeout is 0, servers pick default (120 seconds) */ 224 nr_ioctl_req.Timeout = 225 cpu_to_le32(oparms->tcon->handle_timeout); 226 nr_ioctl_req.Reserved = 0; 227 rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid, 228 fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY, 229 (char *)&nr_ioctl_req, sizeof(nr_ioctl_req), 230 CIFSMaxBufSize, NULL, NULL /* no return info */); 231 if (rc == -EOPNOTSUPP) { 232 cifs_dbg(VFS, 233 "resiliency not supported by server, disabling\n"); 234 oparms->tcon->use_resilient = false; 235 } else if (rc) 236 cifs_dbg(FYI, "error %d setting resiliency\n", rc); 237 238 rc = 0; 239 } 240 241 if (smb2_data) { 242 /* if open response does not have IndexNumber field - get it */ 243 if (smb2_data->IndexNumber == 0) { 244 rc = SMB2_get_srv_num(xid, oparms->tcon, 245 fid->persistent_fid, 246 fid->volatile_fid, 247 &smb2_data->IndexNumber); 248 if (rc) { 249 /* 250 * let get_inode_info disable server inode 251 * numbers 252 */ 253 smb2_data->IndexNumber = 0; 254 rc = 0; 255 } 256 } 257 memcpy(&data->fi, smb2_data, sizeof(data->fi)); 258 } 259 260 *oplock = smb2_oplock; 261 out: 262 free_rsp_buf(err_buftype, err_iov.iov_base); 263 kfree(smb2_path); 264 return rc; 265 } 266 267 int 268 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, 269 const unsigned int xid) 270 { 271 int rc = 0, stored_rc; 272 unsigned int max_num, num = 0, max_buf; 273 struct smb2_lock_element *buf, *cur; 274 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); 275 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry)); 276 struct cifsLockInfo *li, *tmp; 277 __u64 length = 1 + flock->fl_end - flock->fl_start; 278 LIST_HEAD(tmp_llist); 279 280 /* 281 * Accessing maxBuf is racy with cifs_reconnect - need to store value 282 * and check it before using. 283 */ 284 max_buf = tcon->ses->server->maxBuf; 285 if (max_buf < sizeof(struct smb2_lock_element)) 286 return -EINVAL; 287 288 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE); 289 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE); 290 max_num = max_buf / sizeof(struct smb2_lock_element); 291 buf = kzalloc_objs(struct smb2_lock_element, max_num); 292 if (!buf) 293 return -ENOMEM; 294 295 cur = buf; 296 297 cifs_down_write(&cinode->lock_sem); 298 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) { 299 if (flock->fl_start > li->offset || 300 (flock->fl_start + length) < 301 (li->offset + li->length)) 302 continue; 303 if (current->tgid != li->pid) 304 /* 305 * flock and OFD lock are associated with an open 306 * file description, not the process. 307 */ 308 if (!(flock->c.flc_flags & (FL_FLOCK | FL_OFDLCK))) 309 continue; 310 if (cinode->can_cache_brlcks) { 311 /* 312 * We can cache brlock requests - simply remove a lock 313 * from the file's list. 314 */ 315 list_del(&li->llist); 316 cifs_del_lock_waiters(li); 317 kfree(li); 318 continue; 319 } 320 cur->Length = cpu_to_le64(li->length); 321 cur->Offset = cpu_to_le64(li->offset); 322 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK); 323 /* 324 * We need to save a lock here to let us add it again to the 325 * file's list if the unlock range request fails on the server. 326 */ 327 list_move(&li->llist, &tmp_llist); 328 if (++num == max_num) { 329 stored_rc = smb2_lockv(xid, tcon, 330 cfile->fid.persistent_fid, 331 cfile->fid.volatile_fid, 332 current->tgid, num, buf); 333 if (stored_rc) { 334 /* 335 * We failed on the unlock range request - add 336 * all locks from the tmp list to the head of 337 * the file's list. 338 */ 339 cifs_move_llist(&tmp_llist, 340 &cfile->llist->locks); 341 rc = stored_rc; 342 } else 343 /* 344 * The unlock range request succeed - free the 345 * tmp list. 346 */ 347 cifs_free_llist(&tmp_llist); 348 cur = buf; 349 num = 0; 350 } else 351 cur++; 352 } 353 if (num) { 354 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid, 355 cfile->fid.volatile_fid, current->tgid, 356 num, buf); 357 if (stored_rc) { 358 cifs_move_llist(&tmp_llist, &cfile->llist->locks); 359 rc = stored_rc; 360 } else 361 cifs_free_llist(&tmp_llist); 362 } 363 up_write(&cinode->lock_sem); 364 365 kfree(buf); 366 return rc; 367 } 368 369 static int 370 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid, 371 struct smb2_lock_element *buf, unsigned int max_num) 372 { 373 int rc = 0, stored_rc; 374 struct cifsFileInfo *cfile = fdlocks->cfile; 375 struct cifsLockInfo *li; 376 unsigned int num = 0; 377 struct smb2_lock_element *cur = buf; 378 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); 379 380 list_for_each_entry(li, &fdlocks->locks, llist) { 381 cur->Length = cpu_to_le64(li->length); 382 cur->Offset = cpu_to_le64(li->offset); 383 cur->Flags = cpu_to_le32(li->type | 384 SMB2_LOCKFLAG_FAIL_IMMEDIATELY); 385 if (++num == max_num) { 386 stored_rc = smb2_lockv(xid, tcon, 387 cfile->fid.persistent_fid, 388 cfile->fid.volatile_fid, 389 current->tgid, num, buf); 390 if (stored_rc) 391 rc = stored_rc; 392 cur = buf; 393 num = 0; 394 } else 395 cur++; 396 } 397 if (num) { 398 stored_rc = smb2_lockv(xid, tcon, 399 cfile->fid.persistent_fid, 400 cfile->fid.volatile_fid, 401 current->tgid, num, buf); 402 if (stored_rc) 403 rc = stored_rc; 404 } 405 406 return rc; 407 } 408 409 int 410 smb2_push_mandatory_locks(struct cifsFileInfo *cfile) 411 { 412 int rc = 0, stored_rc; 413 unsigned int xid; 414 unsigned int max_num, max_buf; 415 struct smb2_lock_element *buf; 416 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry)); 417 struct cifs_fid_locks *fdlocks; 418 419 xid = get_xid(); 420 421 /* 422 * Accessing maxBuf is racy with cifs_reconnect - need to store value 423 * and check it for zero before using. 424 */ 425 max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf; 426 if (max_buf < sizeof(struct smb2_lock_element)) { 427 free_xid(xid); 428 return -EINVAL; 429 } 430 431 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE); 432 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE); 433 max_num = max_buf / sizeof(struct smb2_lock_element); 434 buf = kzalloc_objs(struct smb2_lock_element, max_num); 435 if (!buf) { 436 free_xid(xid); 437 return -ENOMEM; 438 } 439 440 list_for_each_entry(fdlocks, &cinode->llist, llist) { 441 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num); 442 if (stored_rc) 443 rc = stored_rc; 444 } 445 446 kfree(buf); 447 free_xid(xid); 448 return rc; 449 } 450