fs/cifs/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/stat.h>
  11 #include <linux/slab.h>
  12 #include <linux/pagemap.h>
  13 #include <asm/div64.h>
  14 #include "cifsfs.h"
  15 #include "cifspdu.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 "smb2status.h"
  24
  25 static struct smb2_symlink_err_rsp *symlink_data(const struct kvec *iov)
  26 {
  27         struct smb2_err_rsp *err = iov->iov_base;
  28         struct smb2_symlink_err_rsp *sym = ERR_PTR(-EINVAL);
  29         u32 len;
  30
  31         if (err->ErrorContextCount) {
  32                 struct smb2_error_context_rsp *p, *end;
  33
  34                 len = (u32)err->ErrorContextCount * (offsetof(struct smb2_error_context_rsp,
  35                                                               ErrorContextData) +
  36                                                      sizeof(struct smb2_symlink_err_rsp));
  37                 if (le32_to_cpu(err->ByteCount) < len || iov->iov_len < len + sizeof(*err))
  38                         return ERR_PTR(-EINVAL);
  39
  40                 p = (struct smb2_error_context_rsp *)err->ErrorData;
  41                 end = (struct smb2_error_context_rsp *)((u8 *)err + iov->iov_len);
  42                 do {
  43                         if (le32_to_cpu(p->ErrorId) == SMB2_ERROR_ID_DEFAULT) {
  44                                 sym = (struct smb2_symlink_err_rsp *)&p->ErrorContextData;
  45                                 break;
  46                         }
  47                         cifs_dbg(FYI, "%s: skipping unhandled error context: 0x%x\n",
  48                                  __func__, le32_to_cpu(p->ErrorId));
  49
  50                         len = ALIGN(le32_to_cpu(p->ErrorDataLength), 8);
  51                         p = (struct smb2_error_context_rsp *)((u8 *)&p->ErrorContextData + len);
  52                 } while (p < end);
  53         } else if (le32_to_cpu(err->ByteCount) >= sizeof(*sym) &&
  54                    iov->iov_len >= SMB2_SYMLINK_STRUCT_SIZE) {
  55                 sym = (struct smb2_symlink_err_rsp *)err->ErrorData;
  56         }
  57
  58         if (!IS_ERR(sym) && (le32_to_cpu(sym->SymLinkErrorTag) != SYMLINK_ERROR_TAG ||
  59                              le32_to_cpu(sym->ReparseTag) != IO_REPARSE_TAG_SYMLINK))
  60                 sym = ERR_PTR(-EINVAL);
  61
  62         return sym;
  63 }
  64
  65 int smb2_parse_symlink_response(struct cifs_sb_info *cifs_sb, const struct kvec *iov, char **path)
  66 {
  67         struct smb2_symlink_err_rsp *sym;
  68         unsigned int sub_offs, sub_len;
  69         unsigned int print_offs, print_len;
  70         char *s;
  71
  72         if (!cifs_sb || !iov || !iov->iov_base || !iov->iov_len || !path)
  73                 return -EINVAL;
  74
  75         sym = symlink_data(iov);
  76         if (IS_ERR(sym))
  77                 return PTR_ERR(sym);
  78
  79         sub_len = le16_to_cpu(sym->SubstituteNameLength);
  80         sub_offs = le16_to_cpu(sym->SubstituteNameOffset);
  81         print_len = le16_to_cpu(sym->PrintNameLength);
  82         print_offs = le16_to_cpu(sym->PrintNameOffset);
  83
  84         if (iov->iov_len < SMB2_SYMLINK_STRUCT_SIZE + sub_offs + sub_len ||
  85             iov->iov_len < SMB2_SYMLINK_STRUCT_SIZE + print_offs + print_len)
  86                 return -EINVAL;
  87
  88         s = cifs_strndup_from_utf16((char *)sym->PathBuffer + sub_offs, sub_len, true,
  89                                     cifs_sb->local_nls);
  90         if (!s)
  91                 return -ENOMEM;
  92         convert_delimiter(s, '/');
  93         cifs_dbg(FYI, "%s: symlink target: %s\n", __func__, s);
  94
  95         *path = s;
  96         return 0;
  97 }
  98
  99 int smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms, __u32 *oplock, void *buf)
 100 {
 101         int rc;
 102         __le16 *smb2_path;
 103         __u8 smb2_oplock;
 104         struct cifs_open_info_data *data = buf;
 105         struct smb2_file_all_info file_info = {};
 106         struct smb2_file_all_info *smb2_data = data ? &file_info : NULL;
 107         struct kvec err_iov = {};
 108         int err_buftype = CIFS_NO_BUFFER;
 109         struct cifs_fid *fid = oparms->fid;
 110         struct network_resiliency_req nr_ioctl_req;
 111
 112         smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb);
 113         if (smb2_path == NULL)
 114                 return -ENOMEM;
 115
 116         oparms->desired_access |= FILE_READ_ATTRIBUTES;
 117         smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
 118
 119         rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL, &err_iov,
 120                        &err_buftype);
 121         if (rc && data) {
 122                 struct smb2_hdr *hdr = err_iov.iov_base;
 123
 124                 if (unlikely(!err_iov.iov_base || err_buftype == CIFS_NO_BUFFER))
 125                         rc = -ENOMEM;
 126                 else if (hdr->Status == STATUS_STOPPED_ON_SYMLINK) {
 127                         rc = smb2_parse_symlink_response(oparms->cifs_sb, &err_iov,
 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 }