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 "../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 *)((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         LIST_HEAD(tmp_llist);
 199
 200         /*
 201          * Accessing maxBuf is racy with cifs_reconnect - need to store value
 202          * and check it before using.
 203          */
 204         max_buf = tcon->ses->server->maxBuf;
 205         if (max_buf < sizeof(struct smb2_lock_element))
 206                 return -EINVAL;
 207
 208         BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
 209         max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 210         max_num = max_buf / sizeof(struct smb2_lock_element);
 211         buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
 212         if (!buf)
 213                 return -ENOMEM;
 214
 215         cur = buf;
 216
 217         cifs_down_write(&cinode->lock_sem);
 218         list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
 219                 if (flock->fl_start > li->offset ||
 220                     (flock->fl_start + length) <
 221                     (li->offset + li->length))
 222                         continue;
 223                 if (current->tgid != li->pid)
 224                         /*
 225                          * flock and OFD lock are associated with an open
 226                          * file description, not the process.
 227                          */
 228                         if (!(flock->c.flc_flags & (FL_FLOCK | FL_OFDLCK)))
 229                                 continue;
 230                 if (cinode->can_cache_brlcks) {
 231                         /*
 232                          * We can cache brlock requests - simply remove a lock
 233                          * from the file's list.
 234                          */
 235                         list_del(&li->llist);
 236                         cifs_del_lock_waiters(li);
 237                         kfree(li);
 238                         continue;
 239                 }
 240                 cur->Length = cpu_to_le64(li->length);
 241                 cur->Offset = cpu_to_le64(li->offset);
 242                 cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
 243                 /*
 244                  * We need to save a lock here to let us add it again to the
 245                  * file's list if the unlock range request fails on the server.
 246                  */
 247                 list_move(&li->llist, &tmp_llist);
 248                 if (++num == max_num) {
 249                         stored_rc = smb2_lockv(xid, tcon,
 250                                                cfile->fid.persistent_fid,
 251                                                cfile->fid.volatile_fid,
 252                                                current->tgid, num, buf);
 253                         if (stored_rc) {
 254                                 /*
 255                                  * We failed on the unlock range request - add
 256                                  * all locks from the tmp list to the head of
 257                                  * the file's list.
 258                                  */
 259                                 cifs_move_llist(&tmp_llist,
 260                                                 &cfile->llist->locks);
 261                                 rc = stored_rc;
 262                         } else
 263                                 /*
 264                                  * The unlock range request succeed - free the
 265                                  * tmp list.
 266                                  */
 267                                 cifs_free_llist(&tmp_llist);
 268                         cur = buf;
 269                         num = 0;
 270                 } else
 271                         cur++;
 272         }
 273         if (num) {
 274                 stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
 275                                        cfile->fid.volatile_fid, current->tgid,
 276                                        num, buf);
 277                 if (stored_rc) {
 278                         cifs_move_llist(&tmp_llist, &cfile->llist->locks);
 279                         rc = stored_rc;
 280                 } else
 281                         cifs_free_llist(&tmp_llist);
 282         }
 283         up_write(&cinode->lock_sem);
 284
 285         kfree(buf);
 286         return rc;
 287 }
 288
 289 static int
 290 smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
 291                        struct smb2_lock_element *buf, unsigned int max_num)
 292 {
 293         int rc = 0, stored_rc;
 294         struct cifsFileInfo *cfile = fdlocks->cfile;
 295         struct cifsLockInfo *li;
 296         unsigned int num = 0;
 297         struct smb2_lock_element *cur = buf;
 298         struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
 299
 300         list_for_each_entry(li, &fdlocks->locks, llist) {
 301                 cur->Length = cpu_to_le64(li->length);
 302                 cur->Offset = cpu_to_le64(li->offset);
 303                 cur->Flags = cpu_to_le32(li->type |
 304                                                 SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
 305                 if (++num == max_num) {
 306                         stored_rc = smb2_lockv(xid, tcon,
 307                                                cfile->fid.persistent_fid,
 308                                                cfile->fid.volatile_fid,
 309                                                current->tgid, num, buf);
 310                         if (stored_rc)
 311                                 rc = stored_rc;
 312                         cur = buf;
 313                         num = 0;
 314                 } else
 315                         cur++;
 316         }
 317         if (num) {
 318                 stored_rc = smb2_lockv(xid, tcon,
 319                                        cfile->fid.persistent_fid,
 320                                        cfile->fid.volatile_fid,
 321                                        current->tgid, num, buf);
 322                 if (stored_rc)
 323                         rc = stored_rc;
 324         }
 325
 326         return rc;
 327 }
 328
 329 int
 330 smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
 331 {
 332         int rc = 0, stored_rc;
 333         unsigned int xid;
 334         unsigned int max_num, max_buf;
 335         struct smb2_lock_element *buf;
 336         struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
 337         struct cifs_fid_locks *fdlocks;
 338
 339         xid = get_xid();
 340
 341         /*
 342          * Accessing maxBuf is racy with cifs_reconnect - need to store value
 343          * and check it for zero before using.
 344          */
 345         max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
 346         if (max_buf < sizeof(struct smb2_lock_element)) {
 347                 free_xid(xid);
 348                 return -EINVAL;
 349         }
 350
 351         BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
 352         max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
 353         max_num = max_buf / sizeof(struct smb2_lock_element);
 354         buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
 355         if (!buf) {
 356                 free_xid(xid);
 357                 return -ENOMEM;
 358         }
 359
 360         list_for_each_entry(fdlocks, &cinode->llist, llist) {
 361                 stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
 362                 if (stored_rc)
 363                         rc = stored_rc;
 364         }
 365
 366         kfree(buf);
 367         free_xid(xid);
 368         return rc;
 369 }