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linux/fs/cifs/ioctl.c
Steve French e3e9463414 smb3: improve SMB3 change notification support 
Change notification is a commonly supported feature by most servers,
but the current ioctl to request notification when a directory is
changed does not return the information about what changed
(even though it is returned by the server in the SMB3 change
notify response), it simply returns when there is a change.

This ioctl improves upon CIFS_IOC_NOTIFY by returning the notify
information structure which includes the name of the file(s) that
changed and why. See MS-SMB2 2.2.35 for details on the individual
filter flags and the file_notify_information structure returned.

To use this simply pass in the following (with enough space
to fit at least one file_notify_information structure)

struct __attribute__((__packed__)) smb3_notify {
       uint32_t completion_filter;
       bool     watch_tree;
       uint32_t data_len;
       uint8_t  data[];
} __packed;

using CIFS_IOC_NOTIFY_INFO 0xc009cf0b
 or equivalently _IOWR(CIFS_IOCTL_MAGIC, 11, struct smb3_notify_info)

The ioctl will block until the server detects a change to that
directory or its subdirectories (if watch_tree is set).

Acked-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2022-10-15 10:05:53 -05:00

527 lines
13 KiB
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// SPDX-License-Identifier: LGPL-2.1
/*
*
* vfs operations that deal with io control
*
* Copyright (C) International Business Machines Corp., 2005,2013
* Author(s): Steve French (sfrench@us.ibm.com)
*
*/
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "cifsfs.h"
#include "cifs_ioctl.h"
#include "smb2proto.h"
#include "smb2glob.h"
#include <linux/btrfs.h>
static long cifs_ioctl_query_info(unsigned int xid, struct file *filep,
unsigned long p)
{
struct inode *inode = file_inode(filep);
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
struct dentry *dentry = filep->f_path.dentry;
const unsigned char *path;
void *page = alloc_dentry_path();
__le16 *utf16_path = NULL, root_path;
int rc = 0;
path = build_path_from_dentry(dentry, page);
if (IS_ERR(path)) {
free_dentry_path(page);
return PTR_ERR(path);
}
cifs_dbg(FYI, "%s %s\n", __func__, path);
if (!path[0]) {
root_path = 0;
utf16_path = &root_path;
} else {
utf16_path = cifs_convert_path_to_utf16(path + 1, cifs_sb);
if (!utf16_path) {
rc = -ENOMEM;
goto ici_exit;
}
}
if (tcon->ses->server->ops->ioctl_query_info)
rc = tcon->ses->server->ops->ioctl_query_info(
xid, tcon, cifs_sb, utf16_path,
filep->private_data ? 0 : 1, p);
else
rc = -EOPNOTSUPP;
ici_exit:
if (utf16_path != &root_path)
kfree(utf16_path);
free_dentry_path(page);
return rc;
}
static long cifs_ioctl_copychunk(unsigned int xid, struct file *dst_file,
unsigned long srcfd)
{
int rc;
struct fd src_file;
struct inode *src_inode;
cifs_dbg(FYI, "ioctl copychunk range\n");
/* the destination must be opened for writing */
if (!(dst_file->f_mode & FMODE_WRITE)) {
cifs_dbg(FYI, "file target not open for write\n");
return -EINVAL;
}
/* check if target volume is readonly and take reference */
rc = mnt_want_write_file(dst_file);
if (rc) {
cifs_dbg(FYI, "mnt_want_write failed with rc %d\n", rc);
return rc;
}
src_file = fdget(srcfd);
if (!src_file.file) {
rc = -EBADF;
goto out_drop_write;
}
if (src_file.file->f_op->unlocked_ioctl != cifs_ioctl) {
rc = -EBADF;
cifs_dbg(VFS, "src file seems to be from a different filesystem type\n");
goto out_fput;
}
src_inode = file_inode(src_file.file);
rc = -EINVAL;
if (S_ISDIR(src_inode->i_mode))
goto out_fput;
rc = cifs_file_copychunk_range(xid, src_file.file, 0, dst_file, 0,
src_inode->i_size, 0);
if (rc > 0)
rc = 0;
out_fput:
fdput(src_file);
out_drop_write:
mnt_drop_write_file(dst_file);
return rc;
}
static long smb_mnt_get_fsinfo(unsigned int xid, struct cifs_tcon *tcon,
void __user *arg)
{
int rc = 0;
struct smb_mnt_fs_info *fsinf;
fsinf = kzalloc(sizeof(struct smb_mnt_fs_info), GFP_KERNEL);
if (fsinf == NULL)
return -ENOMEM;
fsinf->version = 1;
fsinf->protocol_id = tcon->ses->server->vals->protocol_id;
fsinf->device_characteristics =
le32_to_cpu(tcon->fsDevInfo.DeviceCharacteristics);
fsinf->device_type = le32_to_cpu(tcon->fsDevInfo.DeviceType);
fsinf->fs_attributes = le32_to_cpu(tcon->fsAttrInfo.Attributes);
fsinf->max_path_component =
le32_to_cpu(tcon->fsAttrInfo.MaxPathNameComponentLength);
fsinf->vol_serial_number = tcon->vol_serial_number;
fsinf->vol_create_time = le64_to_cpu(tcon->vol_create_time);
fsinf->share_flags = tcon->share_flags;
fsinf->share_caps = le32_to_cpu(tcon->capabilities);
fsinf->sector_flags = tcon->ss_flags;
fsinf->optimal_sector_size = tcon->perf_sector_size;
fsinf->max_bytes_chunk = tcon->max_bytes_chunk;
fsinf->maximal_access = tcon->maximal_access;
fsinf->cifs_posix_caps = le64_to_cpu(tcon->fsUnixInfo.Capability);
if (copy_to_user(arg, fsinf, sizeof(struct smb_mnt_fs_info)))
rc = -EFAULT;
kfree(fsinf);
return rc;
}
static int cifs_shutdown(struct super_block *sb, unsigned long arg)
{
struct cifs_sb_info *sbi = CIFS_SB(sb);
__u32 flags;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (get_user(flags, (__u32 __user *)arg))
return -EFAULT;
if (flags > CIFS_GOING_FLAGS_NOLOGFLUSH)
return -EINVAL;
if (cifs_forced_shutdown(sbi))
return 0;
cifs_dbg(VFS, "shut down requested (%d)", flags);
/* trace_cifs_shutdown(sb, flags);*/
/*
* see:
* https://man7.org/linux/man-pages/man2/ioctl_xfs_goingdown.2.html
* for more information and description of original intent of the flags
*/
switch (flags) {
/*
* We could add support later for default flag which requires:
* "Flush all dirty data and metadata to disk"
* would need to call syncfs or equivalent to flush page cache for
* the mount and then issue fsync to server (if nostrictsync not set)
*/
case CIFS_GOING_FLAGS_DEFAULT:
cifs_dbg(FYI, "shutdown with default flag not supported\n");
return -EINVAL;
/*
* FLAGS_LOGFLUSH is easy since it asks to write out metadata (not
* data) but metadata writes are not cached on the client, so can treat
* it similarly to NOLOGFLUSH
*/
case CIFS_GOING_FLAGS_LOGFLUSH:
case CIFS_GOING_FLAGS_NOLOGFLUSH:
sbi->mnt_cifs_flags |= CIFS_MOUNT_SHUTDOWN;
return 0;
default:
return -EINVAL;
}
return 0;
}
static int cifs_dump_full_key(struct cifs_tcon *tcon, struct smb3_full_key_debug_info __user *in)
{
struct smb3_full_key_debug_info out;
struct cifs_ses *ses;
int rc = 0;
bool found = false;
u8 __user *end;
if (!smb3_encryption_required(tcon)) {
rc = -EOPNOTSUPP;
goto out;
}
/* copy user input into our output buffer */
if (copy_from_user(&out, in, sizeof(out))) {
rc = -EINVAL;
goto out;
}
if (!out.session_id) {
/* if ses id is 0, use current user session */
ses = tcon->ses;
} else {
/* otherwise if a session id is given, look for it in all our sessions */
struct cifs_ses *ses_it = NULL;
struct TCP_Server_Info *server_it = NULL;
spin_lock(&cifs_tcp_ses_lock);
list_for_each_entry(server_it, &cifs_tcp_ses_list, tcp_ses_list) {
list_for_each_entry(ses_it, &server_it->smb_ses_list, smb_ses_list) {
if (ses_it->Suid == out.session_id) {
ses = ses_it;
/*
* since we are using the session outside the crit
* section, we need to make sure it won't be released
* so increment its refcount
*/
ses->ses_count++;
found = true;
goto search_end;
}
}
}
search_end:
spin_unlock(&cifs_tcp_ses_lock);
if (!found) {
rc = -ENOENT;
goto out;
}
}
switch (ses->server->cipher_type) {
case SMB2_ENCRYPTION_AES128_CCM:
case SMB2_ENCRYPTION_AES128_GCM:
out.session_key_length = CIFS_SESS_KEY_SIZE;
out.server_in_key_length = out.server_out_key_length = SMB3_GCM128_CRYPTKEY_SIZE;
break;
case SMB2_ENCRYPTION_AES256_CCM:
case SMB2_ENCRYPTION_AES256_GCM:
out.session_key_length = CIFS_SESS_KEY_SIZE;
out.server_in_key_length = out.server_out_key_length = SMB3_GCM256_CRYPTKEY_SIZE;
break;
default:
rc = -EOPNOTSUPP;
goto out;
}
/* check if user buffer is big enough to store all the keys */
if (out.in_size < sizeof(out) + out.session_key_length + out.server_in_key_length
+ out.server_out_key_length) {
rc = -ENOBUFS;
goto out;
}
out.session_id = ses->Suid;
out.cipher_type = le16_to_cpu(ses->server->cipher_type);
/* overwrite user input with our output */
if (copy_to_user(in, &out, sizeof(out))) {
rc = -EINVAL;
goto out;
}
/* append all the keys at the end of the user buffer */
end = in->data;
if (copy_to_user(end, ses->auth_key.response, out.session_key_length)) {
rc = -EINVAL;
goto out;
}
end += out.session_key_length;
if (copy_to_user(end, ses->smb3encryptionkey, out.server_in_key_length)) {
rc = -EINVAL;
goto out;
}
end += out.server_in_key_length;
if (copy_to_user(end, ses->smb3decryptionkey, out.server_out_key_length)) {
rc = -EINVAL;
goto out;
}
out:
if (found)
cifs_put_smb_ses(ses);
return rc;
}
long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg)
{
struct inode *inode = file_inode(filep);
struct smb3_key_debug_info pkey_inf;
int rc = -ENOTTY; /* strange error - but the precedent */
unsigned int xid;
struct cifsFileInfo *pSMBFile = filep->private_data;
struct cifs_tcon *tcon;
struct tcon_link *tlink;
struct cifs_sb_info *cifs_sb;
__u64 ExtAttrBits = 0;
__u64 caps;
xid = get_xid();
cifs_dbg(FYI, "cifs ioctl 0x%x\n", command);
switch (command) {
case FS_IOC_GETFLAGS:
if (pSMBFile == NULL)
break;
tcon = tlink_tcon(pSMBFile->tlink);
caps = le64_to_cpu(tcon->fsUnixInfo.Capability);
#ifdef CONFIG_CIFS_POSIX
#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
if (CIFS_UNIX_EXTATTR_CAP & caps) {
__u64 ExtAttrMask = 0;
rc = CIFSGetExtAttr(xid, tcon,
pSMBFile->fid.netfid,
&ExtAttrBits, &ExtAttrMask);
if (rc == 0)
rc = put_user(ExtAttrBits &
FS_FL_USER_VISIBLE,
(int __user *)arg);
if (rc != EOPNOTSUPP)
break;
}
#endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
#endif /* CONFIG_CIFS_POSIX */
rc = 0;
if (CIFS_I(inode)->cifsAttrs & ATTR_COMPRESSED) {
/* add in the compressed bit */
ExtAttrBits = FS_COMPR_FL;
rc = put_user(ExtAttrBits & FS_FL_USER_VISIBLE,
(int __user *)arg);
}
break;
case FS_IOC_SETFLAGS:
if (pSMBFile == NULL)
break;
tcon = tlink_tcon(pSMBFile->tlink);
/* caps = le64_to_cpu(tcon->fsUnixInfo.Capability); */
if (get_user(ExtAttrBits, (int __user *)arg)) {
rc = -EFAULT;
break;
}
/*
* if (CIFS_UNIX_EXTATTR_CAP & caps)
* rc = CIFSSetExtAttr(xid, tcon,
* pSMBFile->fid.netfid,
* extAttrBits,
* &ExtAttrMask);
* if (rc != EOPNOTSUPP)
* break;
*/
/* Currently only flag we can set is compressed flag */
if ((ExtAttrBits & FS_COMPR_FL) == 0)
break;
/* Try to set compress flag */
if (tcon->ses->server->ops->set_compression) {
rc = tcon->ses->server->ops->set_compression(
xid, tcon, pSMBFile);
cifs_dbg(FYI, "set compress flag rc %d\n", rc);
}
break;
case CIFS_IOC_COPYCHUNK_FILE:
rc = cifs_ioctl_copychunk(xid, filep, arg);
break;
case CIFS_QUERY_INFO:
rc = cifs_ioctl_query_info(xid, filep, arg);
break;
case CIFS_IOC_SET_INTEGRITY:
if (pSMBFile == NULL)
break;
tcon = tlink_tcon(pSMBFile->tlink);
if (tcon->ses->server->ops->set_integrity)
rc = tcon->ses->server->ops->set_integrity(xid,
tcon, pSMBFile);
else
rc = -EOPNOTSUPP;
break;
case CIFS_IOC_GET_MNT_INFO:
if (pSMBFile == NULL)
break;
tcon = tlink_tcon(pSMBFile->tlink);
rc = smb_mnt_get_fsinfo(xid, tcon, (void __user *)arg);
break;
case CIFS_ENUMERATE_SNAPSHOTS:
if (pSMBFile == NULL)
break;
if (arg == 0) {
rc = -EINVAL;
goto cifs_ioc_exit;
}
tcon = tlink_tcon(pSMBFile->tlink);
if (tcon->ses->server->ops->enum_snapshots)
rc = tcon->ses->server->ops->enum_snapshots(xid, tcon,
pSMBFile, (void __user *)arg);
else
rc = -EOPNOTSUPP;
break;
case CIFS_DUMP_KEY:
/*
* Dump encryption keys. This is an old ioctl that only
* handles AES-128-{CCM,GCM}.
*/
if (pSMBFile == NULL)
break;
if (!capable(CAP_SYS_ADMIN)) {
rc = -EACCES;
break;
}
tcon = tlink_tcon(pSMBFile->tlink);
if (!smb3_encryption_required(tcon)) {
rc = -EOPNOTSUPP;
break;
}
pkey_inf.cipher_type =
le16_to_cpu(tcon->ses->server->cipher_type);
pkey_inf.Suid = tcon->ses->Suid;
memcpy(pkey_inf.auth_key, tcon->ses->auth_key.response,
16 /* SMB2_NTLMV2_SESSKEY_SIZE */);
memcpy(pkey_inf.smb3decryptionkey,
tcon->ses->smb3decryptionkey, SMB3_SIGN_KEY_SIZE);
memcpy(pkey_inf.smb3encryptionkey,
tcon->ses->smb3encryptionkey, SMB3_SIGN_KEY_SIZE);
if (copy_to_user((void __user *)arg, &pkey_inf,
sizeof(struct smb3_key_debug_info)))
rc = -EFAULT;
else
rc = 0;
break;
case CIFS_DUMP_FULL_KEY:
/*
* Dump encryption keys (handles any key sizes)
*/
if (pSMBFile == NULL)
break;
if (!capable(CAP_SYS_ADMIN)) {
rc = -EACCES;
break;
}
tcon = tlink_tcon(pSMBFile->tlink);
rc = cifs_dump_full_key(tcon, (void __user *)arg);
break;
case CIFS_IOC_NOTIFY:
if (!S_ISDIR(inode->i_mode)) {
/* Notify can only be done on directories */
rc = -EOPNOTSUPP;
break;
}
cifs_sb = CIFS_SB(inode->i_sb);
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink)) {
rc = PTR_ERR(tlink);
break;
}
tcon = tlink_tcon(tlink);
if (tcon && tcon->ses->server->ops->notify) {
rc = tcon->ses->server->ops->notify(xid,
filep, (void __user *)arg,
false /* no ret data */);
cifs_dbg(FYI, "ioctl notify rc %d\n", rc);
} else
rc = -EOPNOTSUPP;
cifs_put_tlink(tlink);
break;
case CIFS_IOC_NOTIFY_INFO:
if (!S_ISDIR(inode->i_mode)) {
/* Notify can only be done on directories */
rc = -EOPNOTSUPP;
break;
}
cifs_sb = CIFS_SB(inode->i_sb);
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink)) {
rc = PTR_ERR(tlink);
break;
}
tcon = tlink_tcon(tlink);
if (tcon && tcon->ses->server->ops->notify) {
rc = tcon->ses->server->ops->notify(xid,
filep, (void __user *)arg,
true /* return details */);
cifs_dbg(FYI, "ioctl notify info rc %d\n", rc);
} else
rc = -EOPNOTSUPP;
cifs_put_tlink(tlink);
break;
case CIFS_IOC_SHUTDOWN:
rc = cifs_shutdown(inode->i_sb, arg);
break;
default:
cifs_dbg(FYI, "unsupported ioctl\n");
break;
}
cifs_ioc_exit:
free_xid(xid);
return rc;
}
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