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