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, 67 const char *full_path, char **path) 68 { 69 struct smb2_symlink_err_rsp *sym; 70 unsigned int sub_offs, sub_len; 71 unsigned int print_offs, print_len; 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 return smb2_parse_native_symlink(path, 90 (char *)sym->PathBuffer + sub_offs, 91 sub_len, 92 true, 93 le32_to_cpu(sym->Flags) & SYMLINK_FLAG_RELATIVE, 94 full_path, 95 cifs_sb); 96 } 97 98 int smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms, __u32 *oplock, void *buf) 99 { 100 int rc; 101 __le16 *smb2_path; 102 __u8 smb2_oplock; 103 struct cifs_open_info_data *data = buf; 104 struct smb2_file_all_info file_info = {}; 105 struct smb2_file_all_info *smb2_data = data ? &file_info : NULL; 106 struct kvec err_iov = {}; 107 int err_buftype = CIFS_NO_BUFFER; 108 struct cifs_fid *fid = oparms->fid; 109 struct network_resiliency_req nr_ioctl_req; 110 111 smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb); 112 if (smb2_path == NULL) 113 return -ENOMEM; 114 115 oparms->desired_access |= FILE_READ_ATTRIBUTES; 116 smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH; 117 118 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov, 119 &err_buftype); 120 if (rc && data) { 121 struct smb2_hdr *hdr = err_iov.iov_base; 122 123 if (unlikely(!err_iov.iov_base || err_buftype == CIFS_NO_BUFFER)) 124 goto out; 125 if (hdr->Status == STATUS_STOPPED_ON_SYMLINK) { 126 rc = smb2_parse_symlink_response(oparms->cifs_sb, &err_iov, 127 oparms->path, 128 &data->symlink_target); 129 if (!rc) { 130 memset(smb2_data, 0, sizeof(*smb2_data)); 131 oparms->create_options |= OPEN_REPARSE_POINT; 132 rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, 133 NULL, NULL, NULL); 134 oparms->create_options &= ~OPEN_REPARSE_POINT; 135 } 136 } 137 } 138 139 if (rc) 140 goto out; 141 142 if (oparms->tcon->use_resilient) { 143 /* default timeout is 0, servers pick default (120 seconds) */ 144 nr_ioctl_req.Timeout = 145 cpu_to_le32(oparms->tcon->handle_timeout); 146 nr_ioctl_req.Reserved = 0; 147 rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid, 148 fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY, 149 (char *)&nr_ioctl_req, sizeof(nr_ioctl_req), 150 CIFSMaxBufSize, NULL, NULL /* no return info */); 151 if (rc == -EOPNOTSUPP) { 152 cifs_dbg(VFS, 153 "resiliency not supported by server, disabling\n"); 154 oparms->tcon->use_resilient = false; 155 } else if (rc) 156 cifs_dbg(FYI, "error %d setting resiliency\n", rc); 157 158 rc = 0; 159 } 160 161 if (smb2_data) { 162 /* if open response does not have IndexNumber field - get it */ 163 if (smb2_data->IndexNumber == 0) { 164 rc = SMB2_get_srv_num(xid, oparms->tcon, 165 fid->persistent_fid, 166 fid->volatile_fid, 167 &smb2_data->IndexNumber); 168 if (rc) { 169 /* 170 * let get_inode_info disable server inode 171 * numbers 172 */ 173 smb2_data->IndexNumber = 0; 174 rc = 0; 175 } 176 } 177 memcpy(&data->fi, smb2_data, sizeof(data->fi)); 178 } 179 180 *oplock = smb2_oplock; 181 out: 182 free_rsp_buf(err_buftype, err_iov.iov_base); 183 kfree(smb2_path); 184 return rc; 185 } 186 187 int 188 smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, 189 const unsigned int xid) 190 { 191 int rc = 0, stored_rc; 192 unsigned int max_num, num = 0, max_buf; 193 struct smb2_lock_element *buf, *cur; 194 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); 195 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry)); 196 struct cifsLockInfo *li, *tmp; 197 __u64 length = 1 + flock->fl_end - flock->fl_start; 198 struct list_head tmp_llist; 199 200 INIT_LIST_HEAD(&tmp_llist); 201 202 /* 203 * Accessing maxBuf is racy with cifs_reconnect - need to store value 204 * and check it before using. 205 */ 206 max_buf = tcon->ses->server->maxBuf; 207 if (max_buf < sizeof(struct smb2_lock_element)) 208 return -EINVAL; 209 210 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE); 211 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE); 212 max_num = max_buf / sizeof(struct smb2_lock_element); 213 buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL); 214 if (!buf) 215 return -ENOMEM; 216 217 cur = buf; 218 219 cifs_down_write(&cinode->lock_sem); 220 list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) { 221 if (flock->fl_start > li->offset || 222 (flock->fl_start + length) < 223 (li->offset + li->length)) 224 continue; 225 if (current->tgid != li->pid) 226 /* 227 * flock and OFD lock are associated with an open 228 * file description, not the process. 229 */ 230 if (!(flock->fl_flags & (FL_FLOCK | FL_OFDLCK))) 231 continue; 232 if (cinode->can_cache_brlcks) { 233 /* 234 * We can cache brlock requests - simply remove a lock 235 * from the file's list. 236 */ 237 list_del(&li->llist); 238 cifs_del_lock_waiters(li); 239 kfree(li); 240 continue; 241 } 242 cur->Length = cpu_to_le64(li->length); 243 cur->Offset = cpu_to_le64(li->offset); 244 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK); 245 /* 246 * We need to save a lock here to let us add it again to the 247 * file's list if the unlock range request fails on the server. 248 */ 249 list_move(&li->llist, &tmp_llist); 250 if (++num == max_num) { 251 stored_rc = smb2_lockv(xid, tcon, 252 cfile->fid.persistent_fid, 253 cfile->fid.volatile_fid, 254 current->tgid, num, buf); 255 if (stored_rc) { 256 /* 257 * We failed on the unlock range request - add 258 * all locks from the tmp list to the head of 259 * the file's list. 260 */ 261 cifs_move_llist(&tmp_llist, 262 &cfile->llist->locks); 263 rc = stored_rc; 264 } else 265 /* 266 * The unlock range request succeed - free the 267 * tmp list. 268 */ 269 cifs_free_llist(&tmp_llist); 270 cur = buf; 271 num = 0; 272 } else 273 cur++; 274 } 275 if (num) { 276 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid, 277 cfile->fid.volatile_fid, current->tgid, 278 num, buf); 279 if (stored_rc) { 280 cifs_move_llist(&tmp_llist, &cfile->llist->locks); 281 rc = stored_rc; 282 } else 283 cifs_free_llist(&tmp_llist); 284 } 285 up_write(&cinode->lock_sem); 286 287 kfree(buf); 288 return rc; 289 } 290 291 static int 292 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid, 293 struct smb2_lock_element *buf, unsigned int max_num) 294 { 295 int rc = 0, stored_rc; 296 struct cifsFileInfo *cfile = fdlocks->cfile; 297 struct cifsLockInfo *li; 298 unsigned int num = 0; 299 struct smb2_lock_element *cur = buf; 300 struct cifs_tcon *tcon = tlink_tcon(cfile->tlink); 301 302 list_for_each_entry(li, &fdlocks->locks, llist) { 303 cur->Length = cpu_to_le64(li->length); 304 cur->Offset = cpu_to_le64(li->offset); 305 cur->Flags = cpu_to_le32(li->type | 306 SMB2_LOCKFLAG_FAIL_IMMEDIATELY); 307 if (++num == max_num) { 308 stored_rc = smb2_lockv(xid, tcon, 309 cfile->fid.persistent_fid, 310 cfile->fid.volatile_fid, 311 current->tgid, num, buf); 312 if (stored_rc) 313 rc = stored_rc; 314 cur = buf; 315 num = 0; 316 } else 317 cur++; 318 } 319 if (num) { 320 stored_rc = smb2_lockv(xid, tcon, 321 cfile->fid.persistent_fid, 322 cfile->fid.volatile_fid, 323 current->tgid, num, buf); 324 if (stored_rc) 325 rc = stored_rc; 326 } 327 328 return rc; 329 } 330 331 int 332 smb2_push_mandatory_locks(struct cifsFileInfo *cfile) 333 { 334 int rc = 0, stored_rc; 335 unsigned int xid; 336 unsigned int max_num, max_buf; 337 struct smb2_lock_element *buf; 338 struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry)); 339 struct cifs_fid_locks *fdlocks; 340 341 xid = get_xid(); 342 343 /* 344 * Accessing maxBuf is racy with cifs_reconnect - need to store value 345 * and check it for zero before using. 346 */ 347 max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf; 348 if (max_buf < sizeof(struct smb2_lock_element)) { 349 free_xid(xid); 350 return -EINVAL; 351 } 352 353 BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE); 354 max_buf = min_t(unsigned int, max_buf, PAGE_SIZE); 355 max_num = max_buf / sizeof(struct smb2_lock_element); 356 buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL); 357 if (!buf) { 358 free_xid(xid); 359 return -ENOMEM; 360 } 361 362 list_for_each_entry(fdlocks, &cinode->llist, llist) { 363 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num); 364 if (stored_rc) 365 rc = stored_rc; 366 } 367 368 kfree(buf); 369 free_xid(xid); 370 return rc; 371 } 372