fs/smb/client/smb2file.c

   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 }