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 "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 *)((u8 *)&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_parse_symlink_response(struct cifs_sb_info *cifs_sb, const struct kvec *iov, char **path) 67 { 68 struct smb2_symlink_err_rsp *sym; 69 unsigned int sub_offs, sub_len; 70 unsigned int print_offs, print_len; 71 char *s; 72 73 if (!cifs_sb || !iov || !iov->iov_base || !iov->iov_len || !path) 74 return -EINVAL; 75 76 sym = symlink_data(iov); 77 if (IS_ERR(sym)) 78 return PTR_ERR(sym); 79 80 sub_len = le16_to_cpu(sym->SubstituteNameLength); 81 sub_offs = le16_to_cpu(sym->SubstituteNameOffset); 82 print_len = le16_to_cpu(sym->PrintNameLength); 83 print_offs = le16_to_cpu(sym->PrintNameOffset); 84 85 if (iov->iov_len < SMB2_SYMLINK_STRUCT_SIZE + sub_offs + sub_len || 86 iov->iov_len < SMB2_SYMLINK_STRUCT_SIZE + print_offs + print_len) 87 return -EINVAL; 88 89 s = cifs_strndup_from_utf16((char *)sym->PathBuffer + sub_offs, sub_len, true, 90 cifs_sb->local_nls); 91 if (!s) 92 return -ENOMEM; 93 convert_delimiter(s, '/'); 94 cifs_dbg(FYI, "%s: symlink target: %s\n", __func__, s); 95 96 *path = s; 97 return 0; 98 } 99 100 int smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms, __u32 *oplock, void *buf) 101 { 102 int rc; 103 __le16 *smb2_path; 104 __u8 smb2_oplock; 105 struct cifs_open_info_data *data = buf; 106 struct smb2_file_all_info file_info = {}; 107 struct smb2_file_all_info *smb2_data = data ? &file_info : NULL; 108 struct kvec err_iov = {}; 109 int err_buftype = CIFS_NO_BUFFER; 110 struct cifs_fid *fid = oparms->fid; 111 struct network_resiliency_req nr_ioctl_req; 112 113 smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb); 114 if (smb2_path == NULL) 115 return -ENOMEM; 116 117 oparms->desired_access |= FILE_READ_ATTRIBUTES; 118 smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH; 119 120 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov, 121 &err_buftype); 122 if (rc && data) { 123 struct smb2_hdr *hdr = err_iov.iov_base; 124 125 if (unlikely(!err_iov.iov_base || err_buftype == CIFS_NO_BUFFER)) 126 goto out; 127 if (hdr->Status == STATUS_STOPPED_ON_SYMLINK) { 128 rc = smb2_parse_symlink_response(oparms->cifs_sb, &err_iov, 129 &data->symlink_target); 130 if (!rc) { 131 memset(smb2_data, 0, sizeof(*smb2_data)); 132 oparms->create_options |= OPEN_REPARSE_POINT; 133 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, 134 NULL, NULL, NULL); 135 oparms->create_options &= ~OPEN_REPARSE_POINT; 136 } 137 } 138 } 139 140 if (rc) 141 goto out; 142 143 if (oparms->tcon->use_resilient) { 144 /* default timeout is 0, servers pick default (120 seconds) */ 145 nr_ioctl_req.Timeout = 146 cpu_to_le32(oparms->tcon->handle_timeout); 147 nr_ioctl_req.Reserved = 0; 148 rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid, 149 fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY, 150 (char *)&nr_ioctl_req, sizeof(nr_ioctl_req), 151 CIFSMaxBufSize, NULL, NULL /* no return info */); 152 if (rc == -EOPNOTSUPP) { 153 cifs_dbg(VFS, 154 "resiliency not supported by server, disabling\n"); 155 oparms->tcon->use_resilient = false; 156 } else if (rc) 157 cifs_dbg(FYI, "error %d setting resiliency\n", rc); 158 159 rc = 0; 160 } 161 162 if (smb2_data) { 163 /* if open response does not have IndexNumber field - get it */ 164 if (smb2_data->IndexNumber == 0) { 165 rc = SMB2_get_srv_num(xid, oparms->tcon, 166 fid->persistent_fid, 167 fid->volatile_fid, 168 &smb2_data->IndexNumber); 169 if (rc) { 170 /* 171 * let get_inode_info disable server inode 172 * numbers 173 */ 174 smb2_data->IndexNumber = 0; 175 rc = 0; 176 } 177 } 178 memcpy(&data->fi, smb2_data, sizeof(data->fi)); 179 } 180 181 *oplock = smb2_oplock; 182 out: 183 free_rsp_buf(err_buftype, err_iov.iov_base); 184 kfree(smb2_path); 185 return rc; 186 } 187 188 int 189 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, 190 const unsigned int xid) 191 { 192 int rc = 0, stored_rc; 193 unsigned int max_num, num = 0, max_buf; 194 struct smb2_lock_element *buf, *cur; 195 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); 196 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry)); 197 struct cifsLockInfo *li, *tmp; 198 __u64 length = 1 + flock->fl_end - flock->fl_start; 199 struct list_head tmp_llist; 200 201 INIT_LIST_HEAD(&tmp_llist); 202 203 /* 204 * Accessing maxBuf is racy with cifs_reconnect - need to store value 205 * and check it before using. 206 */ 207 max_buf = tcon->ses->server->maxBuf; 208 if (max_buf < sizeof(struct smb2_lock_element)) 209 return -EINVAL; 210 211 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE); 212 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE); 213 max_num = max_buf / sizeof(struct smb2_lock_element); 214 buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL); 215 if (!buf) 216 return -ENOMEM; 217 218 cur = buf; 219 220 cifs_down_write(&cinode->lock_sem); 221 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) { 222 if (flock->fl_start > li->offset || 223 (flock->fl_start + length) < 224 (li->offset + li->length)) 225 continue; 226 if (current->tgid != li->pid) 227 /* 228 * flock and OFD lock are associated with an open 229 * file description, not the process. 230 */ 231 if (!(flock->fl_flags & (FL_FLOCK | FL_OFDLCK))) 232 continue; 233 if (cinode->can_cache_brlcks) { 234 /* 235 * We can cache brlock requests - simply remove a lock 236 * from the file's list. 237 */ 238 list_del(&li->llist); 239 cifs_del_lock_waiters(li); 240 kfree(li); 241 continue; 242 } 243 cur->Length = cpu_to_le64(li->length); 244 cur->Offset = cpu_to_le64(li->offset); 245 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK); 246 /* 247 * We need to save a lock here to let us add it again to the 248 * file's list if the unlock range request fails on the server. 249 */ 250 list_move(&li->llist, &tmp_llist); 251 if (++num == max_num) { 252 stored_rc = smb2_lockv(xid, tcon, 253 cfile->fid.persistent_fid, 254 cfile->fid.volatile_fid, 255 current->tgid, num, buf); 256 if (stored_rc) { 257 /* 258 * We failed on the unlock range request - add 259 * all locks from the tmp list to the head of 260 * the file's list. 261 */ 262 cifs_move_llist(&tmp_llist, 263 &cfile->llist->locks); 264 rc = stored_rc; 265 } else 266 /* 267 * The unlock range request succeed - free the 268 * tmp list. 269 */ 270 cifs_free_llist(&tmp_llist); 271 cur = buf; 272 num = 0; 273 } else 274 cur++; 275 } 276 if (num) { 277 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid, 278 cfile->fid.volatile_fid, current->tgid, 279 num, buf); 280 if (stored_rc) { 281 cifs_move_llist(&tmp_llist, &cfile->llist->locks); 282 rc = stored_rc; 283 } else 284 cifs_free_llist(&tmp_llist); 285 } 286 up_write(&cinode->lock_sem); 287 288 kfree(buf); 289 return rc; 290 } 291 292 static int 293 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid, 294 struct smb2_lock_element *buf, unsigned int max_num) 295 { 296 int rc = 0, stored_rc; 297 struct cifsFileInfo *cfile = fdlocks->cfile; 298 struct cifsLockInfo *li; 299 unsigned int num = 0; 300 struct smb2_lock_element *cur = buf; 301 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); 302 303 list_for_each_entry(li, &fdlocks->locks, llist) { 304 cur->Length = cpu_to_le64(li->length); 305 cur->Offset = cpu_to_le64(li->offset); 306 cur->Flags = cpu_to_le32(li->type | 307 SMB2_LOCKFLAG_FAIL_IMMEDIATELY); 308 if (++num == max_num) { 309 stored_rc = smb2_lockv(xid, tcon, 310 cfile->fid.persistent_fid, 311 cfile->fid.volatile_fid, 312 current->tgid, num, buf); 313 if (stored_rc) 314 rc = stored_rc; 315 cur = buf; 316 num = 0; 317 } else 318 cur++; 319 } 320 if (num) { 321 stored_rc = smb2_lockv(xid, tcon, 322 cfile->fid.persistent_fid, 323 cfile->fid.volatile_fid, 324 current->tgid, num, buf); 325 if (stored_rc) 326 rc = stored_rc; 327 } 328 329 return rc; 330 } 331 332 int 333 smb2_push_mandatory_locks(struct cifsFileInfo *cfile) 334 { 335 int rc = 0, stored_rc; 336 unsigned int xid; 337 unsigned int max_num, max_buf; 338 struct smb2_lock_element *buf; 339 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry)); 340 struct cifs_fid_locks *fdlocks; 341 342 xid = get_xid(); 343 344 /* 345 * Accessing maxBuf is racy with cifs_reconnect - need to store value 346 * and check it for zero before using. 347 */ 348 max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf; 349 if (max_buf < sizeof(struct smb2_lock_element)) { 350 free_xid(xid); 351 return -EINVAL; 352 } 353 354 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE); 355 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE); 356 max_num = max_buf / sizeof(struct smb2_lock_element); 357 buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL); 358 if (!buf) { 359 free_xid(xid); 360 return -ENOMEM; 361 } 362 363 list_for_each_entry(fdlocks, &cinode->llist, llist) { 364 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num); 365 if (stored_rc) 366 rc = stored_rc; 367 } 368 369 kfree(buf); 370 free_xid(xid); 371 return rc; 372 } 373