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 "cifspdu.h" 17 #include "cifsglob.h" 18 #include "cifsproto.h" 19 #include "cifs_debug.h" 20 #include "cifs_fs_sb.h" 21 #include "cifs_unicode.h" 22 #include "fscache.h" 23 #include "smb2proto.h" 24 #include "../common/smb2status.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 oparms->desired_access &= ~FILE_READ_ATTRIBUTES; 182 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov, 183 &err_buftype); 184 } 185 if (rc && data) { 186 struct smb2_hdr *hdr = err_iov.iov_base; 187 188 if (unlikely(!err_iov.iov_base || err_buftype == CIFS_NO_BUFFER)) 189 goto out; 190 if (hdr->Status == STATUS_STOPPED_ON_SYMLINK) { 191 rc = smb2_parse_symlink_response(oparms->cifs_sb, &err_iov, 192 oparms->path, 193 &data->symlink_target); 194 if (!rc) { 195 memset(smb2_data, 0, sizeof(*smb2_data)); 196 oparms->create_options |= OPEN_REPARSE_POINT; 197 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, 198 NULL, NULL, NULL); 199 oparms->create_options &= ~OPEN_REPARSE_POINT; 200 } 201 if (!rc) { 202 bool directory = le32_to_cpu(data->fi.Attributes) & ATTR_DIRECTORY; 203 rc = smb2_fix_symlink_target_type(&data->symlink_target, 204 directory, oparms->cifs_sb); 205 } 206 } 207 } 208 209 if (rc) 210 goto out; 211 212 if (oparms->tcon->use_resilient) { 213 /* default timeout is 0, servers pick default (120 seconds) */ 214 nr_ioctl_req.Timeout = 215 cpu_to_le32(oparms->tcon->handle_timeout); 216 nr_ioctl_req.Reserved = 0; 217 rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid, 218 fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY, 219 (char *)&nr_ioctl_req, sizeof(nr_ioctl_req), 220 CIFSMaxBufSize, NULL, NULL /* no return info */); 221 if (rc == -EOPNOTSUPP) { 222 cifs_dbg(VFS, 223 "resiliency not supported by server, disabling\n"); 224 oparms->tcon->use_resilient = false; 225 } else if (rc) 226 cifs_dbg(FYI, "error %d setting resiliency\n", rc); 227 228 rc = 0; 229 } 230 231 if (smb2_data) { 232 /* if open response does not have IndexNumber field - get it */ 233 if (smb2_data->IndexNumber == 0) { 234 rc = SMB2_get_srv_num(xid, oparms->tcon, 235 fid->persistent_fid, 236 fid->volatile_fid, 237 &smb2_data->IndexNumber); 238 if (rc) { 239 /* 240 * let get_inode_info disable server inode 241 * numbers 242 */ 243 smb2_data->IndexNumber = 0; 244 rc = 0; 245 } 246 } 247 memcpy(&data->fi, smb2_data, sizeof(data->fi)); 248 } 249 250 *oplock = smb2_oplock; 251 out: 252 free_rsp_buf(err_buftype, err_iov.iov_base); 253 kfree(smb2_path); 254 return rc; 255 } 256 257 int 258 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, 259 const unsigned int xid) 260 { 261 int rc = 0, stored_rc; 262 unsigned int max_num, num = 0, max_buf; 263 struct smb2_lock_element *buf, *cur; 264 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); 265 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry)); 266 struct cifsLockInfo *li, *tmp; 267 __u64 length = 1 + flock->fl_end - flock->fl_start; 268 LIST_HEAD(tmp_llist); 269 270 /* 271 * Accessing maxBuf is racy with cifs_reconnect - need to store value 272 * and check it before using. 273 */ 274 max_buf = tcon->ses->server->maxBuf; 275 if (max_buf < sizeof(struct smb2_lock_element)) 276 return -EINVAL; 277 278 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE); 279 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE); 280 max_num = max_buf / sizeof(struct smb2_lock_element); 281 buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL); 282 if (!buf) 283 return -ENOMEM; 284 285 cur = buf; 286 287 cifs_down_write(&cinode->lock_sem); 288 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) { 289 if (flock->fl_start > li->offset || 290 (flock->fl_start + length) < 291 (li->offset + li->length)) 292 continue; 293 if (current->tgid != li->pid) 294 /* 295 * flock and OFD lock are associated with an open 296 * file description, not the process. 297 */ 298 if (!(flock->c.flc_flags & (FL_FLOCK | FL_OFDLCK))) 299 continue; 300 if (cinode->can_cache_brlcks) { 301 /* 302 * We can cache brlock requests - simply remove a lock 303 * from the file's list. 304 */ 305 list_del(&li->llist); 306 cifs_del_lock_waiters(li); 307 kfree(li); 308 continue; 309 } 310 cur->Length = cpu_to_le64(li->length); 311 cur->Offset = cpu_to_le64(li->offset); 312 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK); 313 /* 314 * We need to save a lock here to let us add it again to the 315 * file's list if the unlock range request fails on the server. 316 */ 317 list_move(&li->llist, &tmp_llist); 318 if (++num == max_num) { 319 stored_rc = smb2_lockv(xid, tcon, 320 cfile->fid.persistent_fid, 321 cfile->fid.volatile_fid, 322 current->tgid, num, buf); 323 if (stored_rc) { 324 /* 325 * We failed on the unlock range request - add 326 * all locks from the tmp list to the head of 327 * the file's list. 328 */ 329 cifs_move_llist(&tmp_llist, 330 &cfile->llist->locks); 331 rc = stored_rc; 332 } else 333 /* 334 * The unlock range request succeed - free the 335 * tmp list. 336 */ 337 cifs_free_llist(&tmp_llist); 338 cur = buf; 339 num = 0; 340 } else 341 cur++; 342 } 343 if (num) { 344 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid, 345 cfile->fid.volatile_fid, current->tgid, 346 num, buf); 347 if (stored_rc) { 348 cifs_move_llist(&tmp_llist, &cfile->llist->locks); 349 rc = stored_rc; 350 } else 351 cifs_free_llist(&tmp_llist); 352 } 353 up_write(&cinode->lock_sem); 354 355 kfree(buf); 356 return rc; 357 } 358 359 static int 360 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid, 361 struct smb2_lock_element *buf, unsigned int max_num) 362 { 363 int rc = 0, stored_rc; 364 struct cifsFileInfo *cfile = fdlocks->cfile; 365 struct cifsLockInfo *li; 366 unsigned int num = 0; 367 struct smb2_lock_element *cur = buf; 368 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); 369 370 list_for_each_entry(li, &fdlocks->locks, llist) { 371 cur->Length = cpu_to_le64(li->length); 372 cur->Offset = cpu_to_le64(li->offset); 373 cur->Flags = cpu_to_le32(li->type | 374 SMB2_LOCKFLAG_FAIL_IMMEDIATELY); 375 if (++num == max_num) { 376 stored_rc = smb2_lockv(xid, tcon, 377 cfile->fid.persistent_fid, 378 cfile->fid.volatile_fid, 379 current->tgid, num, buf); 380 if (stored_rc) 381 rc = stored_rc; 382 cur = buf; 383 num = 0; 384 } else 385 cur++; 386 } 387 if (num) { 388 stored_rc = smb2_lockv(xid, tcon, 389 cfile->fid.persistent_fid, 390 cfile->fid.volatile_fid, 391 current->tgid, num, buf); 392 if (stored_rc) 393 rc = stored_rc; 394 } 395 396 return rc; 397 } 398 399 int 400 smb2_push_mandatory_locks(struct cifsFileInfo *cfile) 401 { 402 int rc = 0, stored_rc; 403 unsigned int xid; 404 unsigned int max_num, max_buf; 405 struct smb2_lock_element *buf; 406 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry)); 407 struct cifs_fid_locks *fdlocks; 408 409 xid = get_xid(); 410 411 /* 412 * Accessing maxBuf is racy with cifs_reconnect - need to store value 413 * and check it for zero before using. 414 */ 415 max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf; 416 if (max_buf < sizeof(struct smb2_lock_element)) { 417 free_xid(xid); 418 return -EINVAL; 419 } 420 421 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE); 422 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE); 423 max_num = max_buf / sizeof(struct smb2_lock_element); 424 buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL); 425 if (!buf) { 426 free_xid(xid); 427 return -ENOMEM; 428 } 429 430 list_for_each_entry(fdlocks, &cinode->llist, llist) { 431 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num); 432 if (stored_rc) 433 rc = stored_rc; 434 } 435 436 kfree(buf); 437 free_xid(xid); 438 return rc; 439 } 440