2012/6/21 Jeff Layton <jlayton@xxxxxxxxxx>:
> On Wed, 20 Jun 2012 18:30:47 +0400
> Pavel Shilovsky <pshilovsky@xxxxxxxxx> wrote:
>
>> From: Pavel Shilovsky <piastryyy@xxxxxxxxx>
>>
>> Now we can process SMB2 messages: check message, get message id
>> and wakeup awaiting routines.
>>
>> Signed-off-by: Pavel Shilovsky <piastryyy@xxxxxxxxx>
>> ---
>> fs/cifs/Makefile | 2 +-
>> fs/cifs/cifs_debug.c | 2 +-
>> fs/cifs/smb2misc.c | 304 ++++++++++++++++++++++++++++++++++++++++++++++++++
>> fs/cifs/smb2ops.c | 37 ++++++
>> fs/cifs/smb2pdu.h | 30 +++++
>> fs/cifs/smb2proto.h | 2 +
>> 6 files changed, 375 insertions(+), 2 deletions(-)
>> create mode 100644 fs/cifs/smb2misc.c
>>
>> diff --git a/fs/cifs/Makefile b/fs/cifs/Makefile
>> index a73d7f8..b77e9ec 100644
>> --- a/fs/cifs/Makefile
>> +++ b/fs/cifs/Makefile
>> @@ -16,4 +16,4 @@ cifs-$(CONFIG_CIFS_DFS_UPCALL) += dns_resolve.o cifs_dfs_ref.o
>>
>> cifs-$(CONFIG_CIFS_FSCACHE) += fscache.o cache.o
>>
>> -cifs-$(CONFIG_CIFS_SMB2) += smb2ops.o smb2maperror.o smb2transport.o
>> +cifs-$(CONFIG_CIFS_SMB2) += smb2ops.o smb2maperror.o smb2transport.o smb2misc.o
>> diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
>> index e814052..8aa8693 100644
>> --- a/fs/cifs/cifs_debug.c
>> +++ b/fs/cifs/cifs_debug.c
>> @@ -65,7 +65,7 @@ void cifs_dump_detail(void *buf)
>> cERROR(1, "Cmd: %d Err: 0x%x Flags: 0x%x Flgs2: 0x%x Mid: %d Pid: %d",
>> smb->Command, smb->Status.CifsError,
>> smb->Flags, smb->Flags2, smb->Mid, smb->Pid);
>> - cERROR(1, "smb buf %p len %d", smb, smbCalcSize(smb));
>> + cERROR(1, "smb buf %p len %u", smb, smbCalcSize(smb));
>> #endif /* CONFIG_CIFS_DEBUG2 */
>> }
>>
>> diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
>> new file mode 100644
>> index 0000000..03167eb
>> --- /dev/null
>> +++ b/fs/cifs/smb2misc.c
>> @@ -0,0 +1,304 @@
>> +/*
>> + * fs/cifs/smb2misc.c
>> + *
>> + * Copyright (C) International Business Machines Corp., 2002,2011
>> + * Etersoft, 2012
>> + * Author(s): Steve French (sfrench@xxxxxxxxxx)
>> + * Pavel Shilovsky (pshilovsky@xxxxxxxxx) 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 == cpu_to_le32(0x424d53fe)) &&
>
> ... == __constant_cpu_to_le32()
>
> It would also be good to turn that into a #define'ed constant and use it in the check below.
>
>> + (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
>> + cERROR(1, "Received Request not response");
>> + }
>> + } else { /* bad signature or mid */
>> + if (*(__le32 *)hdr->ProtocolId != cpu_to_le32(0x424d53fe))
>> + cERROR(1, "Bad protocol string signature header %x",
>> + *(unsigned int *) hdr->ProtocolId);
>> + if (mid != hdr->MessageId)
>> + cERROR(1, "Mids do not match");
>> + }
>> + cERROR(1, "Bad SMB detected. The Mid=%llu", 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 int smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
>> + /* SMB2_NEGOTIATE */ 65,
>> + /* SMB2_SESSION_SETUP */ 9,
>> + /* SMB2_LOGOFF */ 4,
>> + /* SMB2_TREE_CONNECT */ 16,
>> + /* SMB2_TREE_DISCONNECT */ 4,
>> + /* SMB2_CREATE */ 89,
>> + /* SMB2_CLOSE */ 60,
>> + /* SMB2_FLUSH */ 4,
>> + /* SMB2_READ */ 17,
>> + /* SMB2_WRITE */ 17,
>> + /* SMB2_LOCK */ 4,
>> + /* SMB2_IOCTL */ 49,
>> + /* SMB2_CANCEL */ 0, /* BB CHECK this ... not listed in documentation */
>> + /* SMB2_ECHO */ 4,
>> + /* SMB2_QUERY_DIRECTORY */ 9,
>> + /* SMB2_CHANGE_NOTIFY */ 9,
>> + /* SMB2_QUERY_INFO */ 9,
>> + /* SMB2_SET_INFO */ 2,
>> + /* SMB2_OPLOCK_BREAK */ 24 /* BB FIXME can also be 44 for lease break */
>> +};
>> +
>
> It might save a few cycles (and memory) to make the above an array of
> __le16's and go ahead and __constant_cpu_to_le16 the values. Then you
> wouldn't need to convert the values in the headers below.
Yes, make sense.
>
>> +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 */
>> + cFYI(1, "checkSMB Length: 0x%x, smb_buf_length: 0x%x", length, len);
>> +
>> + /*
>> + * Add function to do table lookup of StructureSize by command
>> + * ie Validate the wct via smb2_struct_sizes table above
>> + */
>> +
>> + if (length < 2 + sizeof(struct smb2_hdr)) {
>> + 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 {
>> + cERROR(1, "Length less than smb header size");
>> + }
>> + return 1;
>> + }
>> + if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE - 4) {
>> + cERROR(1, "smb length greater than maximum, mid=%lld", mid);
>> + return 1;
>> + }
>> +
>> + if (check_smb2_hdr(hdr, mid))
>> + return 1;
>> +
>> + if (le16_to_cpu(hdr->StructureSize) != 64) {
>> + cERROR(1, "Illegal structure size %d",
>> + le16_to_cpu(hdr->StructureSize));
>> + return 1;
>> + }
>> +
>> + command = le16_to_cpu(hdr->Command);
>> + if (command >= NUMBER_OF_SMB2_COMMANDS) {
>> + cERROR(1, "illegal SMB2 command %d", command);
>> + return 1;
>> + }
>> +
>> + if (smb2_rsp_struct_sizes[command] !=
>> + le16_to_cpu(pdu->StructureSize2)) {
>> + if ((hdr->Status == 0) ||
>> + (le16_to_cpu(pdu->StructureSize2) != 9)) {
> The 9 here should probably be a preprocessor constant:
>
> #define SMB2_ERROR_STRUCTURE_SIZE2 __constant_le16_to_cpu(9)
>
> Then you could just compare that to a bare pdu->StructureSize2
>
>> + /* error packets have 9 byte structure size */
>> + cERROR(1, "Illegal response size %d for command %d",
>> + le16_to_cpu(pdu->StructureSize2), command);
>> + return 1;
>> + }
>> + }
>> +
>> + clc_len = smb2_calc_size(hdr);
>> +
>> + if (4 + len != length) {
>> + cERROR(1, "Length read does not match RFC1001 length %d",
>> + len);
>> + return 1;
>> + }
>
>
> Does RFC1001 apply here? The error message above could be clearer.
>
>> +
>> + if (4 + len != clc_len) {
>> + cFYI(1, "Calculated size %d length %d mismatch for mid %lld",
>> + clc_len, 4 + len, mid);
>> + if (clc_len == 4 + len + 1) /* BB FIXME (fix samba) */
>> + return 0; /* BB workaround Samba 3 bug SessSetup rsp */
>> + 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.
>> + */
>> +static 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 &&
>> + (le32_to_cpu(hdr->Status) != STATUS_MORE_PROCESSING_REQUIRED) &&
>
> I wonder...should we also convert the STATUS_* constants to LE values?
> That would save a few cycles on BE machines...
In this case we should probably convert nterr.h too -- Steve, what do you think?
>
>> + (le16_to_cpu(((struct smb2_err_rsp *)hdr)->StructureSize) == 9))
>> + 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:
>> + case SMB2_SESSION_SETUP:
>> + case SMB2_CREATE:
>> + case SMB2_READ:
>> + case SMB2_QUERY_INFO:
>> + case SMB2_QUERY_DIRECTORY:
>> + case SMB2_IOCTL:
>> + case SMB2_CHANGE_NOTIFY:
>> + default:
>> + /* BB FIXME for unimplemented cases above */
>> + cERROR(1, "no length check for command");
>> + 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) {
>> + dump_stack();
>
> Is a stack trace likely to be helpful here? I wouldn't think so...
>
>> + cERROR(1, "offset %d too large, data area ignored", *off);
>> + *len = 0;
>> + *off = 0;
>> + } else if (*off < 0) {
>> + cERROR(1, "negative offset to data invalid ignore data area");
>
> Printing the actual value might be helpful.
>
>> + *off = 0;
>> + *len = 0;
>> + } else if (*len < 0) {
>> + cERROR(1, "negative data length invalid, data area ignored");
>
> Ditto...
>
>> + *len = 0;
>> + } else if (*len > 128 * 1024) {
>> + cERROR(1, "data area larger than 128K");
>
> How big was it?
>
>> + *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(struct smb2_hdr *hdr)
>> +{
>> + 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);
>> + cFYI(1, "smb2 data length %d offset %d", 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) {
>> + cERROR(1, "data area overlaps SMB2 header, ignoring");
>
> Again, some info that would help us to debug this situation might be
> helpful. What were offset and len?
>
>> + data_length = 0;
>> + } else {
>> + len = 4 + offset + data_length;
>> + }
>> + }
>> +calc_size_exit:
>> + cFYI(1, "smb2 len %d", len);
>> + return len;
>> +}
>> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
>> index ab2590f..88cbfce 100644
>> --- a/fs/cifs/smb2ops.c
>> +++ b/fs/cifs/smb2ops.c
>> @@ -105,6 +105,38 @@ smb2_get_next_mid(struct TCP_Server_Info *server)
>> return mid;
>> }
>>
>> +static struct mid_q_entry *
>> +smb2_find_mid(struct TCP_Server_Info *server, char *buf)
>> +{
>> + struct mid_q_entry *mid;
>> + struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
>> +
>> + spin_lock(&GlobalMid_Lock);
>> + list_for_each_entry(mid, &server->pending_mid_q, qhead) {
>> + if ((mid->mid == hdr->MessageId) &&
>> + (mid->mid_state == MID_REQUEST_SUBMITTED) &&
>> + (mid->command == hdr->Command)) {
>> + spin_unlock(&GlobalMid_Lock);
>> + return mid;
>> + }
>> + }
>> + spin_unlock(&GlobalMid_Lock);
>> + return NULL;
>> +}
>> +
>> +static void
>> +smb2_dump_detail(void *buf)
>> +{
>> +#ifdef CONFIG_CIFS_DEBUG2
>> + struct smb2_hdr *smb = (struct smb2_hdr *)buf;
>> +
>> + cERROR(1, "Cmd: %d Err: 0x%x Flags: 0x%x Mid: %llu Pid: %d",
>> + smb->Command, smb->Status, smb->Flags, smb->MessageId,
>> + smb->ProcessId);
>> + cERROR(1, "smb buf %p len %u", smb, smb2_calc_size(smb));
>> +#endif
>> +}
>> +
>> struct smb_version_operations smb21_operations = {
>> .setup_request = smb2_setup_request,
>> .check_receive = smb2_check_receive,
>> @@ -113,9 +145,14 @@ struct smb_version_operations smb21_operations = {
>> .get_credits_field = smb2_get_credits_field,
>> .get_credits = smb2_get_credits,
>> .get_next_mid = smb2_get_next_mid,
>> + .find_mid = smb2_find_mid,
>> + .check_message = smb2_check_message,
>> + .dump_detail = smb2_dump_detail,
>> };
>>
>> struct smb_version_values smb21_values = {
>> .version_string = SMB21_VERSION_STRING,
>> + .header_size = sizeof(struct smb2_hdr),
>> + .max_header_size = MAX_SMB2_HDR_SIZE,
>> .lock_cmd = SMB2_LOCK,
>> };
>> diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
>> index c7f52e3..efb0d98 100644
>> --- a/fs/cifs/smb2pdu.h
>> +++ b/fs/cifs/smb2pdu.h
>> @@ -112,4 +112,34 @@ struct smb2_hdr {
>> __u8 Signature[16];
>> } __packed;
>>
>> +struct smb2_pdu {
>> + struct smb2_hdr hdr;
>> + __le16 StructureSize2; /* size of wct area (varies, request specific) */
>> +} __packed;
>> +
>> +/*
>> + * SMB2 flag definitions
>> + */
>> +#define SMB2_FLAGS_SERVER_TO_REDIR cpu_to_le32(0x00000001) /* Response */
>> +#define SMB2_FLAGS_ASYNC_COMMAND cpu_to_le32(0x00000002)
>> +#define SMB2_FLAGS_RELATED_OPERATIONS cpu_to_le32(0x00000004)
>> +#define SMB2_FLAGS_SIGNED cpu_to_le32(0x00000008)
>> +#define SMB2_FLAGS_DFS_OPERATIONS cpu_to_le32(0x10000000)
>> +
>
> Probably should use __constant_cpu_to_le32 here, though these macros
> can sometimes figure that out (if __builtin_constant_p is true for these
> values).
>
>> +/*
>> + * Definitions for SMB2 Protocol Data Units (network frames)
>> + *
>> + * See MS-SMB2.PDF specification for protocol details.
>> + * The Naming convention is the lower case version of the SMB2
>> + * command code name for the struct. Note that structures must be packed.
>> + *
>> + */
>> +struct smb2_err_rsp {
>> + struct smb2_hdr hdr;
>> + __le16 StructureSize;
>> + __le16 Reserved; /* MBZ */
>> + __le32 ByteCount; /* even if zero, at least one byte follows */
>> + __u8 ErrorData[1]; /* variable length */
>> +} __packed;
>> +
>> #endif /* _SMB2PDU_H */
>> diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
>> index 0e59afb..19bf987 100644
>> --- a/fs/cifs/smb2proto.h
>> +++ b/fs/cifs/smb2proto.h
>> @@ -33,6 +33,8 @@ struct statfs;
>> *****************************************************************
>> */
>> extern int map_smb2_to_linux_error(char *buf, bool log_err);
>> +extern int smb2_check_message(char *buf, unsigned int length);
>> +extern unsigned int smb2_calc_size(struct smb2_hdr *hdr);
>>
>> extern int smb2_check_receive(struct mid_q_entry *mid,
>> struct TCP_Server_Info *server, bool log_error);
>
>
> --
> Jeff Layton <jlayton@xxxxxxxxxx>
Thanks for the review - agree with your points. Since other patches
from the series don't depend on these changes, I will repost this one
with the whole series again when we finish with other patches.
--
Best regards,
Pavel Shilovsky.
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