cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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smb2file.c (7488B)


      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
     24int
     25smb2_open_file(const unsigned int xid, struct cifs_open_parms *oparms,
     26	       __u32 *oplock, FILE_ALL_INFO *buf)
     27{
     28	int rc;
     29	__le16 *smb2_path;
     30	struct smb2_file_all_info *smb2_data = NULL;
     31	__u8 smb2_oplock;
     32	struct cifs_fid *fid = oparms->fid;
     33	struct network_resiliency_req nr_ioctl_req;
     34
     35	smb2_path = cifs_convert_path_to_utf16(oparms->path, oparms->cifs_sb);
     36	if (smb2_path == NULL) {
     37		rc = -ENOMEM;
     38		goto out;
     39	}
     40
     41	smb2_data = kzalloc(sizeof(struct smb2_file_all_info) + PATH_MAX * 2,
     42			    GFP_KERNEL);
     43	if (smb2_data == NULL) {
     44		rc = -ENOMEM;
     45		goto out;
     46	}
     47
     48	oparms->desired_access |= FILE_READ_ATTRIBUTES;
     49	smb2_oplock = SMB2_OPLOCK_LEVEL_BATCH;
     50
     51	rc = SMB2_open(xid, oparms, smb2_path, &smb2_oplock, smb2_data, NULL,
     52		       NULL, NULL);
     53	if (rc)
     54		goto out;
     55
     56
     57	if (oparms->tcon->use_resilient) {
     58		/* default timeout is 0, servers pick default (120 seconds) */
     59		nr_ioctl_req.Timeout =
     60			cpu_to_le32(oparms->tcon->handle_timeout);
     61		nr_ioctl_req.Reserved = 0;
     62		rc = SMB2_ioctl(xid, oparms->tcon, fid->persistent_fid,
     63			fid->volatile_fid, FSCTL_LMR_REQUEST_RESILIENCY,
     64			true /* is_fsctl */,
     65			(char *)&nr_ioctl_req, sizeof(nr_ioctl_req),
     66			CIFSMaxBufSize, NULL, NULL /* no return info */);
     67		if (rc == -EOPNOTSUPP) {
     68			cifs_dbg(VFS,
     69			     "resiliency not supported by server, disabling\n");
     70			oparms->tcon->use_resilient = false;
     71		} else if (rc)
     72			cifs_dbg(FYI, "error %d setting resiliency\n", rc);
     73
     74		rc = 0;
     75	}
     76
     77	if (buf) {
     78		/* if open response does not have IndexNumber field - get it */
     79		if (smb2_data->IndexNumber == 0) {
     80			rc = SMB2_get_srv_num(xid, oparms->tcon,
     81				      fid->persistent_fid,
     82				      fid->volatile_fid,
     83				      &smb2_data->IndexNumber);
     84			if (rc) {
     85				/*
     86				 * let get_inode_info disable server inode
     87				 * numbers
     88				 */
     89				smb2_data->IndexNumber = 0;
     90				rc = 0;
     91			}
     92		}
     93		move_smb2_info_to_cifs(buf, smb2_data);
     94	}
     95
     96	*oplock = smb2_oplock;
     97out:
     98	kfree(smb2_data);
     99	kfree(smb2_path);
    100	return rc;
    101}
    102
    103int
    104smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
    105		  const unsigned int xid)
    106{
    107	int rc = 0, stored_rc;
    108	unsigned int max_num, num = 0, max_buf;
    109	struct smb2_lock_element *buf, *cur;
    110	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
    111	struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
    112	struct cifsLockInfo *li, *tmp;
    113	__u64 length = 1 + flock->fl_end - flock->fl_start;
    114	struct list_head tmp_llist;
    115
    116	INIT_LIST_HEAD(&tmp_llist);
    117
    118	/*
    119	 * Accessing maxBuf is racy with cifs_reconnect - need to store value
    120	 * and check it before using.
    121	 */
    122	max_buf = tcon->ses->server->maxBuf;
    123	if (max_buf < sizeof(struct smb2_lock_element))
    124		return -EINVAL;
    125
    126	BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
    127	max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
    128	max_num = max_buf / sizeof(struct smb2_lock_element);
    129	buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
    130	if (!buf)
    131		return -ENOMEM;
    132
    133	cur = buf;
    134
    135	cifs_down_write(&cinode->lock_sem);
    136	list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) {
    137		if (flock->fl_start > li->offset ||
    138		    (flock->fl_start + length) <
    139		    (li->offset + li->length))
    140			continue;
    141		if (current->tgid != li->pid)
    142			/*
    143			 * flock and OFD lock are associated with an open
    144			 * file description, not the process.
    145			 */
    146			if (!(flock->fl_flags & (FL_FLOCK | FL_OFDLCK)))
    147				continue;
    148		if (cinode->can_cache_brlcks) {
    149			/*
    150			 * We can cache brlock requests - simply remove a lock
    151			 * from the file's list.
    152			 */
    153			list_del(&li->llist);
    154			cifs_del_lock_waiters(li);
    155			kfree(li);
    156			continue;
    157		}
    158		cur->Length = cpu_to_le64(li->length);
    159		cur->Offset = cpu_to_le64(li->offset);
    160		cur->Flags = cpu_to_le32(SMB2_LOCKFLAG_UNLOCK);
    161		/*
    162		 * We need to save a lock here to let us add it again to the
    163		 * file's list if the unlock range request fails on the server.
    164		 */
    165		list_move(&li->llist, &tmp_llist);
    166		if (++num == max_num) {
    167			stored_rc = smb2_lockv(xid, tcon,
    168					       cfile->fid.persistent_fid,
    169					       cfile->fid.volatile_fid,
    170					       current->tgid, num, buf);
    171			if (stored_rc) {
    172				/*
    173				 * We failed on the unlock range request - add
    174				 * all locks from the tmp list to the head of
    175				 * the file's list.
    176				 */
    177				cifs_move_llist(&tmp_llist,
    178						&cfile->llist->locks);
    179				rc = stored_rc;
    180			} else
    181				/*
    182				 * The unlock range request succeed - free the
    183				 * tmp list.
    184				 */
    185				cifs_free_llist(&tmp_llist);
    186			cur = buf;
    187			num = 0;
    188		} else
    189			cur++;
    190	}
    191	if (num) {
    192		stored_rc = smb2_lockv(xid, tcon, cfile->fid.persistent_fid,
    193				       cfile->fid.volatile_fid, current->tgid,
    194				       num, buf);
    195		if (stored_rc) {
    196			cifs_move_llist(&tmp_llist, &cfile->llist->locks);
    197			rc = stored_rc;
    198		} else
    199			cifs_free_llist(&tmp_llist);
    200	}
    201	up_write(&cinode->lock_sem);
    202
    203	kfree(buf);
    204	return rc;
    205}
    206
    207static int
    208smb2_push_mand_fdlocks(struct cifs_fid_locks *fdlocks, const unsigned int xid,
    209		       struct smb2_lock_element *buf, unsigned int max_num)
    210{
    211	int rc = 0, stored_rc;
    212	struct cifsFileInfo *cfile = fdlocks->cfile;
    213	struct cifsLockInfo *li;
    214	unsigned int num = 0;
    215	struct smb2_lock_element *cur = buf;
    216	struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
    217
    218	list_for_each_entry(li, &fdlocks->locks, llist) {
    219		cur->Length = cpu_to_le64(li->length);
    220		cur->Offset = cpu_to_le64(li->offset);
    221		cur->Flags = cpu_to_le32(li->type |
    222						SMB2_LOCKFLAG_FAIL_IMMEDIATELY);
    223		if (++num == max_num) {
    224			stored_rc = smb2_lockv(xid, tcon,
    225					       cfile->fid.persistent_fid,
    226					       cfile->fid.volatile_fid,
    227					       current->tgid, num, buf);
    228			if (stored_rc)
    229				rc = stored_rc;
    230			cur = buf;
    231			num = 0;
    232		} else
    233			cur++;
    234	}
    235	if (num) {
    236		stored_rc = smb2_lockv(xid, tcon,
    237				       cfile->fid.persistent_fid,
    238				       cfile->fid.volatile_fid,
    239				       current->tgid, num, buf);
    240		if (stored_rc)
    241			rc = stored_rc;
    242	}
    243
    244	return rc;
    245}
    246
    247int
    248smb2_push_mandatory_locks(struct cifsFileInfo *cfile)
    249{
    250	int rc = 0, stored_rc;
    251	unsigned int xid;
    252	unsigned int max_num, max_buf;
    253	struct smb2_lock_element *buf;
    254	struct cifsInodeInfo *cinode = CIFS_I(d_inode(cfile->dentry));
    255	struct cifs_fid_locks *fdlocks;
    256
    257	xid = get_xid();
    258
    259	/*
    260	 * Accessing maxBuf is racy with cifs_reconnect - need to store value
    261	 * and check it for zero before using.
    262	 */
    263	max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf;
    264	if (max_buf < sizeof(struct smb2_lock_element)) {
    265		free_xid(xid);
    266		return -EINVAL;
    267	}
    268
    269	BUILD_BUG_ON(sizeof(struct smb2_lock_element) > PAGE_SIZE);
    270	max_buf = min_t(unsigned int, max_buf, PAGE_SIZE);
    271	max_num = max_buf / sizeof(struct smb2_lock_element);
    272	buf = kcalloc(max_num, sizeof(struct smb2_lock_element), GFP_KERNEL);
    273	if (!buf) {
    274		free_xid(xid);
    275		return -ENOMEM;
    276	}
    277
    278	list_for_each_entry(fdlocks, &cinode->llist, llist) {
    279		stored_rc = smb2_push_mand_fdlocks(fdlocks, xid, buf, max_num);
    280		if (stored_rc)
    281			rc = stored_rc;
    282	}
    283
    284	kfree(buf);
    285	free_xid(xid);
    286	return rc;
    287}