- 根目录:
- fs
- cifs
- smb2misc.c
/*
* fs/cifs/smb2misc.c
*
* Copyright (C) International Business Machines Corp., 2002,2011
* Etersoft, 2012
* Author(s): Steve French (sfrench@us.ibm.com)
* Pavel Shilovsky (pshilovsky@samba.org) 2012
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/ctype.h>
#include "smb2pdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "smb2proto.h"
#include "cifs_debug.h"
#include "cifs_unicode.h"
#include "smb2status.h"
static int
check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
{
/*
* Make sure that this really is an SMB, that it is a response,
* and that the message ids match.
*/
if ((*(__le32 *)hdr->ProtocolId == SMB2_PROTO_NUMBER) &&
(mid == hdr->MessageId)) {
if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
return 0;
else {
/* only one valid case where server sends us request */
if (hdr->Command == SMB2_OPLOCK_BREAK)
return 0;
else
cifs_dbg(VFS, "Received Request not response\n");
}
} else { /* bad signature or mid */
if (*(__le32 *)hdr->ProtocolId != SMB2_PROTO_NUMBER)
cifs_dbg(VFS, "Bad protocol string signature header %x\n",
*(unsigned int *) hdr->ProtocolId);
if (mid != hdr->MessageId)
cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
mid, hdr->MessageId);
}
cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", hdr->MessageId);
return 1;
}
/*
* The following table defines the expected "StructureSize" of SMB2 responses
* in order by SMB2 command. This is similar to "wct" in SMB/CIFS responses.
*
* Note that commands are defined in smb2pdu.h in le16 but the array below is
* indexed by command in host byte order
*/
static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
/* SMB2_NEGOTIATE */ __constant_cpu_to_le16(65),
/* SMB2_SESSION_SETUP */ __constant_cpu_to_le16(9),
/* SMB2_LOGOFF */ __constant_cpu_to_le16(4),
/* SMB2_TREE_CONNECT */ __constant_cpu_to_le16(16),
/* SMB2_TREE_DISCONNECT */ __constant_cpu_to_le16(4),
/* SMB2_CREATE */ __constant_cpu_to_le16(89),
/* SMB2_CLOSE */ __constant_cpu_to_le16(60),
/* SMB2_FLUSH */ __constant_cpu_to_le16(4),
/* SMB2_READ */ __constant_cpu_to_le16(17),
/* SMB2_WRITE */ __constant_cpu_to_le16(17),
/* SMB2_LOCK */ __constant_cpu_to_le16(4),
/* SMB2_IOCTL */ __constant_cpu_to_le16(49),
/* BB CHECK this ... not listed in documentation */
/* SMB2_CANCEL */ __constant_cpu_to_le16(0),
/* SMB2_ECHO */ __constant_cpu_to_le16(4),
/* SMB2_QUERY_DIRECTORY */ __constant_cpu_to_le16(9),
/* SMB2_CHANGE_NOTIFY */ __constant_cpu_to_le16(9),
/* SMB2_QUERY_INFO */ __constant_cpu_to_le16(9),
/* SMB2_SET_INFO */ __constant_cpu_to_le16(2),
/* BB FIXME can also be 44 for lease break */
/* SMB2_OPLOCK_BREAK */ __constant_cpu_to_le16(24)
};
int
smb2_check_message(char *buf, unsigned int length)
{
struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
__u64 mid = hdr->MessageId;
__u32 len = get_rfc1002_length(buf);
__u32 clc_len; /* calculated length */
int command;
/* BB disable following printk later */
cifs_dbg(FYI, "%s length: 0x%x, smb_buf_length: 0x%x\n",
__func__, length, len);
/*
* Add function to do table lookup of StructureSize by command
* ie Validate the wct via smb2_struct_sizes table above
*/
if (length < sizeof(struct smb2_pdu)) {
if ((length >= sizeof(struct smb2_hdr)) && (hdr->Status != 0)) {
pdu->StructureSize2 = 0;
/*
* As with SMB/CIFS, on some error cases servers may
* not return wct properly
*/
return 0;
} else {
cifs_dbg(VFS, "Length less than SMB header size\n");
}
return 1;
}
if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE - 4) {
cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
mid);
return 1;
}
if (check_smb2_hdr(hdr, mid))
return 1;
if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
cifs_dbg(VFS, "Illegal structure size %u\n",
le16_to_cpu(hdr->StructureSize));
return 1;
}
command = le16_to_cpu(hdr->Command);
if (command >= NUMBER_OF_SMB2_COMMANDS) {
cifs_dbg(VFS, "Illegal SMB2 command %d\n", command);
return 1;
}
if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
if (command != SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0 ||
pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2)) {
/* error packets have 9 byte structure size */
cifs_dbg(VFS, "Illegal response size %u for command %d\n",
le16_to_cpu(pdu->StructureSize2), command);
return 1;
} else if (command == SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0)
&& (le16_to_cpu(pdu->StructureSize2) != 44)
&& (le16_to_cpu(pdu->StructureSize2) != 36)) {
/* special case for SMB2.1 lease break message */
cifs_dbg(VFS, "Illegal response size %d for oplock break\n",
le16_to_cpu(pdu->StructureSize2));
return 1;
}
}
if (4 + len != length) {
cifs_dbg(VFS, "Total length %u RFC1002 length %u mismatch mid %llu\n",
length, 4 + len, mid);
return 1;
}
clc_len = smb2_calc_size(hdr);
if (4 + len != clc_len) {
cifs_dbg(FYI, "Calculated size %u length %u mismatch mid %llu\n",
clc_len, 4 + len, mid);
/* create failed on symlink */
if (command == SMB2_CREATE_HE &&
hdr->Status == STATUS_STOPPED_ON_SYMLINK)
return 0;
/* Windows 7 server returns 24 bytes more */
if (clc_len + 20 == len && command == SMB2_OPLOCK_BREAK_HE)
return 0;
/* server can return one byte more due to implied bcc[0] */
if (clc_len == 4 + len + 1)
return 0;
/*
* MacOS server pads after SMB2.1 write response with 3 bytes
* of junk. Other servers match RFC1001 len to actual
* SMB2/SMB3 frame length (header + smb2 response specific data)
* Log the server error (once), but allow it and continue
* since the frame is parseable.
*/
if (clc_len < 4 /* RFC1001 header size */ + len) {
printk_once(KERN_WARNING
"SMB2 server sent bad RFC1001 len %d not %d\n",
len, clc_len - 4);
return 0;
}
return 1;
}
return 0;
}
/*
* The size of the variable area depends on the offset and length fields
* located in different fields for various SMB2 responses. SMB2 responses
* with no variable length info, show an offset of zero for the offset field.
*/
static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
/* SMB2_NEGOTIATE */ true,
/* SMB2_SESSION_SETUP */ true,
/* SMB2_LOGOFF */ false,
/* SMB2_TREE_CONNECT */ false,
/* SMB2_TREE_DISCONNECT */ false,
/* SMB2_CREATE */ true,
/* SMB2_CLOSE */ false,
/* SMB2_FLUSH */ false,
/* SMB2_READ */ true,
/* SMB2_WRITE */ false,
/* SMB2_LOCK */ false,
/* SMB2_IOCTL */ true,
/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
/* SMB2_ECHO */ false,
/* SMB2_QUERY_DIRECTORY */ true,
/* SMB2_CHANGE_NOTIFY */ true,
/* SMB2_QUERY_INFO */ true,
/* SMB2_SET_INFO */ false,
/* SMB2_OPLOCK_BREAK */ false
};
/*
* Returns the pointer to the beginning of the data area. Length of the data
* area and the offset to it (from the beginning of the smb are also returned.
*/
char *
smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *hdr)
{
*off = 0;
*len = 0;
/* error responses do not have data area */
if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
(((struct smb2_err_rsp *)hdr)->StructureSize) ==
SMB2_ERROR_STRUCTURE_SIZE2)
return NULL;
/*
* Following commands have data areas so we have to get the location
* of the data buffer offset and data buffer length for the particular
* command.
*/
switch (hdr->Command) {
case SMB2_NEGOTIATE:
*off = le16_to_cpu(
((struct smb2_negotiate_rsp *)hdr)->SecurityBufferOffset);
*len = le16_to_cpu(
((struct smb2_negotiate_rsp *)hdr)->SecurityBufferLength);
break;
case SMB2_SESSION_SETUP:
*off = le16_to_cpu(
((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferOffset);
*len = le16_to_cpu(
((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferLength);
break;
case SMB2_CREATE:
*off = le32_to_cpu(
((struct smb2_create_rsp *)hdr)->CreateContextsOffset);
*len = le32_to_cpu(
((struct smb2_create_rsp *)hdr)->CreateContextsLength);
break;
case SMB2_QUERY_INFO:
*off = le16_to_cpu(
((struct smb2_query_info_rsp *)hdr)->OutputBufferOffset);
*len = le32_to_cpu(
((struct smb2_query_info_rsp *)hdr)->OutputBufferLength);
break;
case SMB2_READ:
*off = ((struct smb2_read_rsp *)hdr)->DataOffset;
*len = le32_to_cpu(((struct smb2_read_rsp *)hdr)->DataLength);
break;
case SMB2_QUERY_DIRECTORY:
*off = le16_to_cpu(
((struct smb2_query_directory_rsp *)hdr)->OutputBufferOffset);
*len = le32_to_cpu(
((struct smb2_query_directory_rsp *)hdr)->OutputBufferLength);
break;
case SMB2_IOCTL:
*off = le32_to_cpu(
((struct smb2_ioctl_rsp *)hdr)->OutputOffset);
*len = le32_to_cpu(((struct smb2_ioctl_rsp *)hdr)->OutputCount);
break;
case SMB2_CHANGE_NOTIFY:
default:
/* BB FIXME for unimplemented cases above */
cifs_dbg(VFS, "no length check for command\n");
break;
}
/*
* Invalid length or offset probably means data area is invalid, but
* we have little choice but to ignore the data area in this case.
*/
if (*off > 4096) {
cifs_dbg(VFS, "offset %d too large, data area ignored\n", *off);
*len = 0;
*off = 0;
} else if (*off < 0) {
cifs_dbg(VFS, "negative offset %d to data invalid ignore data area\n",
*off);
*off = 0;
*len = 0;
} else if (*len < 0) {
cifs_dbg(VFS, "negative data length %d invalid, data area ignored\n",
*len);
*len = 0;
} else if (*len > 128 * 1024) {
cifs_dbg(VFS, "data area larger than 128K: %d\n", *len);
*len = 0;
}
/* return pointer to beginning of data area, ie offset from SMB start */
if ((*off != 0) && (*len != 0))
return hdr->ProtocolId + *off;
else
return NULL;
}
/*
* Calculate the size of the SMB message based on the fixed header
* portion, the number of word parameters and the data portion of the message.
*/
unsigned int
smb2_calc_size(void *buf)
{
struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
int offset; /* the offset from the beginning of SMB to data area */
int data_length; /* the length of the variable length data area */
/* Structure Size has already been checked to make sure it is 64 */
int len = 4 + le16_to_cpu(pdu->hdr.StructureSize);
/*
* StructureSize2, ie length of fixed parameter area has already
* been checked to make sure it is the correct length.
*/
len += le16_to_cpu(pdu->StructureSize2);
if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false)
goto calc_size_exit;
smb2_get_data_area_len(&offset, &data_length, hdr);
cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
if (data_length > 0) {
/*
* Check to make sure that data area begins after fixed area,
* Note that last byte of the fixed area is part of data area
* for some commands, typically those with odd StructureSize,
* so we must add one to the calculation (and 4 to account for
* the size of the RFC1001 hdr.
*/
if (offset + 4 + 1 < len) {
cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
offset + 4 + 1, len);
data_length = 0;
} else {
len = 4 + offset + data_length;
}
}
calc_size_exit:
cifs_dbg(FYI, "SMB2 len %d\n", len);
return len;
}
/* Note: caller must free return buffer */
__le16 *
cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
{
int len;
const char *start_of_path;
__le16 *to;
int map_type;
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
map_type = SFM_MAP_UNI_RSVD;
else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
map_type = SFU_MAP_UNI_RSVD;
else
map_type = NO_MAP_UNI_RSVD;
/* Windows doesn't allow paths beginning with \ */
if (from[0] == '\\')
start_of_path = from + 1;
else
start_of_path = from;
to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
cifs_sb->local_nls, map_type);
return to;
}
__le32
smb2_get_lease_state(struct cifsInodeInfo *cinode)
{
__le32 lease = 0;
if (CIFS_CACHE_WRITE(cinode))
lease |= SMB2_LEASE_WRITE_CACHING;
if (CIFS_CACHE_HANDLE(cinode))
lease |= SMB2_LEASE_HANDLE_CACHING;
if (CIFS_CACHE_READ(cinode))
lease |= SMB2_LEASE_READ_CACHING;
return lease;
}
struct smb2_lease_break_work {
struct work_struct lease_break;
struct tcon_link *tlink;
__u8 lease_key[16];
__le32 lease_state;
};
static void
cifs_ses_oplock_break(struct work_struct *work)
{
struct smb2_lease_break_work *lw = container_of(work,
struct smb2_lease_break_work, lease_break);
int rc;
rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
lw->lease_state);
cifs_dbg(FYI, "Lease release rc %d\n", rc);
cifs_put_tlink(lw->tlink);
kfree(lw);
}
static bool
smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp,
struct smb2_lease_break_work *lw)
{
bool found;
__u8 lease_state;
struct list_head *tmp;
struct cifsFileInfo *cfile;
struct TCP_Server_Info *server = tcon->ses->server;
struct cifs_pending_open *open;
struct cifsInodeInfo *cinode;
int ack_req = le32_to_cpu(rsp->Flags &
SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
lease_state = le32_to_cpu(rsp->NewLeaseState);
list_for_each(tmp, &tcon->openFileList) {
cfile = list_entry(tmp, struct cifsFileInfo, tlist);
cinode = CIFS_I(cfile->dentry->d_inode);
if (memcmp(cinode->lease_key, rsp->LeaseKey,
SMB2_LEASE_KEY_SIZE))
continue;
cifs_dbg(FYI, "found in the open list\n");
cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
le32_to_cpu(rsp->NewLeaseState));
server->ops->set_oplock_level(cinode, lease_state, 0, NULL);
if (ack_req)
cfile->oplock_break_cancelled = false;
else
cfile->oplock_break_cancelled = true;
queue_work(cifsiod_wq, &cfile->oplock_break);
kfree(lw);
return true;
}
found = false;
list_for_each_entry(open, &tcon->pending_opens, olist) {
if (memcmp(open->lease_key, rsp->LeaseKey,
SMB2_LEASE_KEY_SIZE))
continue;
if (!found && ack_req) {
found = true;
memcpy(lw->lease_key, open->lease_key,
SMB2_LEASE_KEY_SIZE);
lw->tlink = cifs_get_tlink(open->tlink);
queue_work(cifsiod_wq, &lw->lease_break);
}
cifs_dbg(FYI, "found in the pending open list\n");
cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
le32_to_cpu(rsp->NewLeaseState));
open->oplock = lease_state;
}
return found;
}
static bool
smb2_is_valid_lease_break(char *buffer)
{
struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
struct list_head *tmp, *tmp1, *tmp2;
struct TCP_Server_Info *server;
struct cifs_ses *ses;
struct cifs_tcon *tcon;
struct smb2_lease_break_work *lw;
lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
if (!lw)
return false;
INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
lw->lease_state = rsp->NewLeaseState;
cifs_dbg(FYI, "Checking for lease break\n");
/* look up tcon based on tid & uid */
spin_lock(&cifs_tcp_ses_lock);
list_for_each(tmp, &cifs_tcp_ses_list) {
server = list_entry(tmp, struct TCP_Server_Info, tcp_ses_list);
list_for_each(tmp1, &server->smb_ses_list) {
ses = list_entry(tmp1, struct cifs_ses, smb_ses_list);
spin_lock(&cifs_file_list_lock);
list_for_each(tmp2, &ses->tcon_list) {
tcon = list_entry(tmp2, struct cifs_tcon,
tcon_list);
cifs_stats_inc(
&tcon->stats.cifs_stats.num_oplock_brks);
if (smb2_tcon_has_lease(tcon, rsp, lw)) {
spin_unlock(&cifs_file_list_lock);
spin_unlock(&cifs_tcp_ses_lock);
return true;
}
}
spin_unlock(&cifs_file_list_lock);
}
}
spin_unlock(&cifs_tcp_ses_lock);
kfree(lw);
cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
return false;
}
bool
smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
{
struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
struct list_head *tmp, *tmp1, *tmp2;
struct cifs_ses *ses;
struct cifs_tcon *tcon;
struct cifsInodeInfo *cinode;
struct cifsFileInfo *cfile;
cifs_dbg(FYI, "Checking for oplock break\n");
if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
return false;
if (rsp->StructureSize !=
smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
if (le16_to_cpu(rsp->StructureSize) == 44)
return smb2_is_valid_lease_break(buffer);
else
return false;
}
cifs_dbg(FYI, "oplock level 0x%x\n", rsp->OplockLevel);
/* look up tcon based on tid & uid */
spin_lock(&cifs_tcp_ses_lock);
list_for_each(tmp, &server->smb_ses_list) {
ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
list_for_each(tmp1, &ses->tcon_list) {
tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
spin_lock(&cifs_file_list_lock);
list_for_each(tmp2, &tcon->openFileList) {
cfile = list_entry(tmp2, struct cifsFileInfo,
tlist);
if (rsp->PersistentFid !=
cfile->fid.persistent_fid ||
rsp->VolatileFid !=
cfile->fid.volatile_fid)
continue;
cifs_dbg(FYI, "file id match, oplock break\n");
cinode = CIFS_I(cfile->dentry->d_inode);
if (!CIFS_CACHE_WRITE(cinode) &&
rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
cfile->oplock_break_cancelled = true;
else
cfile->oplock_break_cancelled = false;
set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
&cinode->flags);
/*
* Set flag if the server downgrades the oplock
* to L2 else clear.
*/
if (rsp->OplockLevel)
set_bit(
CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
&cinode->flags);
else
clear_bit(
CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
&cinode->flags);
queue_work(cifsiod_wq, &cfile->oplock_break);
spin_unlock(&cifs_file_list_lock);
spin_unlock(&cifs_tcp_ses_lock);
return true;
}
spin_unlock(&cifs_file_list_lock);
spin_unlock(&cifs_tcp_ses_lock);
cifs_dbg(FYI, "No matching file for oplock break\n");
return true;
}
}
spin_unlock(&cifs_tcp_ses_lock);
cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
return false;
}