[people/ms/linux.git] / fs / ksmbd / smb2misc.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
 *   Copyright (C) 2018 Samsung Electronics Co., Ltd.
 */

#include "glob.h"
#include "nterr.h"
#include "smb2pdu.h"
#include "smb_common.h"
#include "smbstatus.h"
#include "mgmt/user_session.h"
#include "connection.h"

static int check_smb2_hdr(struct smb2_hdr *hdr)
{
	/*
	 * Make sure that this really is an SMB, that it is a response.
	 */
	if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
		return 1;
	return 0;
}

/*
 *  The following table defines the expected "StructureSize" of SMB2 requests
 *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS requests.
 *
 *  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_req_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
	/* SMB2_NEGOTIATE */ cpu_to_le16(36),
	/* SMB2_SESSION_SETUP */ cpu_to_le16(25),
	/* SMB2_LOGOFF */ cpu_to_le16(4),
	/* SMB2_TREE_CONNECT */ cpu_to_le16(9),
	/* SMB2_TREE_DISCONNECT */ cpu_to_le16(4),
	/* SMB2_CREATE */ cpu_to_le16(57),
	/* SMB2_CLOSE */ cpu_to_le16(24),
	/* SMB2_FLUSH */ cpu_to_le16(24),
	/* SMB2_READ */ cpu_to_le16(49),
	/* SMB2_WRITE */ cpu_to_le16(49),
	/* SMB2_LOCK */ cpu_to_le16(48),
	/* SMB2_IOCTL */ cpu_to_le16(57),
	/* SMB2_CANCEL */ cpu_to_le16(4),
	/* SMB2_ECHO */ cpu_to_le16(4),
	/* SMB2_QUERY_DIRECTORY */ cpu_to_le16(33),
	/* SMB2_CHANGE_NOTIFY */ cpu_to_le16(32),
	/* SMB2_QUERY_INFO */ cpu_to_le16(41),
	/* SMB2_SET_INFO */ cpu_to_le16(33),
	/* use 44 for lease break */
	/* SMB2_OPLOCK_BREAK */ cpu_to_le16(36)
};

/*
 * The size of the variable area depends on the offset and length fields
 * located in different fields for various SMB2 requests. SMB2 requests
 * 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 */	true,
	/* SMB2_TREE_DISCONNECT */ false,
	/* SMB2_CREATE */ true,
	/* SMB2_CLOSE */ false,
	/* SMB2_FLUSH */ false,
	/* SMB2_READ */	true,
	/* SMB2_WRITE */ true,
	/* SMB2_LOCK */	true,
	/* SMB2_IOCTL */ true,
	/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
	/* SMB2_ECHO */ false,
	/* SMB2_QUERY_DIRECTORY */ true,
	/* SMB2_CHANGE_NOTIFY */ false,
	/* SMB2_QUERY_INFO */ true,
	/* SMB2_SET_INFO */ true,
	/* SMB2_OPLOCK_BREAK */ false
};

/*
 * Set length of the data area and the offset to arguments.
 * if they are invalid, return error.
 */
static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
				  struct smb2_hdr *hdr)
{
	int ret = 0;

	*off = 0;
	*len = 0;

	/* error reqeusts do not have data area */
	if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
	    (((struct smb2_err_rsp *)hdr)->StructureSize) == SMB2_ERROR_STRUCTURE_SIZE2_LE)
		return ret;

	/*
	 * 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_SESSION_SETUP:
		*off = le16_to_cpu(((struct smb2_sess_setup_req *)hdr)->SecurityBufferOffset);
		*len = le16_to_cpu(((struct smb2_sess_setup_req *)hdr)->SecurityBufferLength);
		break;
	case SMB2_TREE_CONNECT:
		*off = le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathOffset);
		*len = le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathLength);
		break;
	case SMB2_CREATE:
	{
		if (((struct smb2_create_req *)hdr)->CreateContextsLength) {
			*off = le32_to_cpu(((struct smb2_create_req *)
				hdr)->CreateContextsOffset);
			*len = le32_to_cpu(((struct smb2_create_req *)
				hdr)->CreateContextsLength);
			break;
		}

		*off = le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset);
		*len = le16_to_cpu(((struct smb2_create_req *)hdr)->NameLength);
		break;
	}
	case SMB2_QUERY_INFO:
		*off = le16_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferOffset);
		*len = le32_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferLength);
		break;
	case SMB2_SET_INFO:
		*off = le16_to_cpu(((struct smb2_set_info_req *)hdr)->BufferOffset);
		*len = le32_to_cpu(((struct smb2_set_info_req *)hdr)->BufferLength);
		break;
	case SMB2_READ:
		*off = le16_to_cpu(((struct smb2_read_req *)hdr)->ReadChannelInfoOffset);
		*len = le16_to_cpu(((struct smb2_read_req *)hdr)->ReadChannelInfoLength);
		break;
	case SMB2_WRITE:
		if (((struct smb2_write_req *)hdr)->DataOffset) {
			*off = le16_to_cpu(((struct smb2_write_req *)hdr)->DataOffset);
			*len = le32_to_cpu(((struct smb2_write_req *)hdr)->Length);
			break;
		}

		*off = le16_to_cpu(((struct smb2_write_req *)hdr)->WriteChannelInfoOffset);
		*len = le16_to_cpu(((struct smb2_write_req *)hdr)->WriteChannelInfoLength);
		break;
	case SMB2_QUERY_DIRECTORY:
		*off = le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameOffset);
		*len = le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameLength);
		break;
	case SMB2_LOCK:
	{
		int lock_count;

		/*
		 * smb2_lock request size is 48 included single
		 * smb2_lock_element structure size.
		 */
		lock_count = le16_to_cpu(((struct smb2_lock_req *)hdr)->LockCount) - 1;
		if (lock_count > 0) {
			*off = __SMB2_HEADER_STRUCTURE_SIZE + 48;
			*len = sizeof(struct smb2_lock_element) * lock_count;
		}
		break;
	}
	case SMB2_IOCTL:
		*off = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputOffset);
		*len = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputCount);
		break;
	default:
		ksmbd_debug(SMB, "no length check for command\n");
		break;
	}

	if (*off > 4096) {
		ksmbd_debug(SMB, "offset %d too large\n", *off);
		ret = -EINVAL;
	} else if ((u64)*off + *len > MAX_STREAM_PROT_LEN) {
		ksmbd_debug(SMB, "Request is larger than maximum stream protocol length(%u): %llu\n",
			    MAX_STREAM_PROT_LEN, (u64)*off + *len);
		ret = -EINVAL;
	}

	return ret;
}

/*
 * 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.
 */
static int smb2_calc_size(void *buf, unsigned int *len)
{
	struct smb2_pdu *pdu = (struct smb2_pdu *)buf;
	struct smb2_hdr *hdr = &pdu->hdr;
	unsigned int offset; /* the offset from the beginning of SMB to data area */
	unsigned int data_length; /* the length of the variable length data area */
	int ret;

	/* Structure Size has already been checked to make sure it is 64 */
	*len = le16_to_cpu(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);
	/*
	 * StructureSize2 of smb2_lock pdu is set to 48, indicating
	 * the size of smb2 lock request with single smb2_lock_element
	 * regardless of number of locks. Subtract single
	 * smb2_lock_element for correct buffer size check.
	 */
	if (hdr->Command == SMB2_LOCK)
		*len -= sizeof(struct smb2_lock_element);

	if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false)
		goto calc_size_exit;

	ret = smb2_get_data_area_len(&offset, &data_length, hdr);
	if (ret)
		return ret;
	ksmbd_debug(SMB, "SMB2 data length %u offset %u\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.
		 */
		if (offset + 1 < *len) {
			ksmbd_debug(SMB,
				    "data area offset %d overlaps SMB2 header %u\n",
				    offset + 1, *len);
			return -EINVAL;
		}

		*len = offset + data_length;
	}

calc_size_exit:
	ksmbd_debug(SMB, "SMB2 len %u\n", *len);
	return 0;
}

static inline int smb2_query_info_req_len(struct smb2_query_info_req *h)
{
	return le32_to_cpu(h->InputBufferLength) +
		le32_to_cpu(h->OutputBufferLength);
}

static inline int smb2_set_info_req_len(struct smb2_set_info_req *h)
{
	return le32_to_cpu(h->BufferLength);
}

static inline int smb2_read_req_len(struct smb2_read_req *h)
{
	return le32_to_cpu(h->Length);
}

static inline int smb2_write_req_len(struct smb2_write_req *h)
{
	return le32_to_cpu(h->Length);
}

static inline int smb2_query_dir_req_len(struct smb2_query_directory_req *h)
{
	return le32_to_cpu(h->OutputBufferLength);
}

static inline int smb2_ioctl_req_len(struct smb2_ioctl_req *h)
{
	return le32_to_cpu(h->InputCount) +
		le32_to_cpu(h->OutputCount);
}

static inline int smb2_ioctl_resp_len(struct smb2_ioctl_req *h)
{
	return le32_to_cpu(h->MaxInputResponse) +
		le32_to_cpu(h->MaxOutputResponse);
}

static int smb2_validate_credit_charge(struct ksmbd_conn *conn,
				       struct smb2_hdr *hdr)
{
	unsigned int req_len = 0, expect_resp_len = 0, calc_credit_num, max_len;
	unsigned short credit_charge = le16_to_cpu(hdr->CreditCharge);
	void *__hdr = hdr;
	int ret;

	switch (hdr->Command) {
	case SMB2_QUERY_INFO:
		req_len = smb2_query_info_req_len(__hdr);
		break;
	case SMB2_SET_INFO:
		req_len = smb2_set_info_req_len(__hdr);
		break;
	case SMB2_READ:
		req_len = smb2_read_req_len(__hdr);
		break;
	case SMB2_WRITE:
		req_len = smb2_write_req_len(__hdr);
		break;
	case SMB2_QUERY_DIRECTORY:
		req_len = smb2_query_dir_req_len(__hdr);
		break;
	case SMB2_IOCTL:
		req_len = smb2_ioctl_req_len(__hdr);
		expect_resp_len = smb2_ioctl_resp_len(__hdr);
		break;
	case SMB2_CANCEL:
		return 0;
	default:
		req_len = 1;
		break;
	}

	credit_charge = max_t(unsigned short, credit_charge, 1);
	max_len = max_t(unsigned int, req_len, expect_resp_len);
	calc_credit_num = DIV_ROUND_UP(max_len, SMB2_MAX_BUFFER_SIZE);

	if (credit_charge < calc_credit_num) {
		ksmbd_debug(SMB, "Insufficient credit charge, given: %d, needed: %d\n",
			    credit_charge, calc_credit_num);
		return 1;
	} else if (credit_charge > conn->max_credits) {
		ksmbd_debug(SMB, "Too large credit charge: %d\n", credit_charge);
		return 1;
	}

	spin_lock(&conn->credits_lock);
	if (credit_charge <= conn->total_credits) {
		conn->total_credits -= credit_charge;
		ret = 0;
	} else {
		ksmbd_debug(SMB, "Insufficient credits granted, given: %u, granted: %u\n",
			    credit_charge, conn->total_credits);
		ret = 1;
	}
	spin_unlock(&conn->credits_lock);
	return ret;
}

int ksmbd_smb2_check_message(struct ksmbd_work *work)
{
	struct smb2_pdu *pdu = work->request_buf;
	struct smb2_hdr *hdr = &pdu->hdr;
	int command;
	__u32 clc_len;  /* calculated length */
	__u32 len = get_rfc1002_len(pdu);

	if (work->next_smb2_rcv_hdr_off) {
		pdu = ksmbd_req_buf_next(work);
		hdr = &pdu->hdr;
	}

	if (le32_to_cpu(hdr->NextCommand) > 0) {
		len = le32_to_cpu(hdr->NextCommand);
	} else if (work->next_smb2_rcv_hdr_off) {
		len -= work->next_smb2_rcv_hdr_off;
		len = round_up(len, 8);
	}

	if (check_smb2_hdr(hdr))
		return 1;

	if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
		ksmbd_debug(SMB, "Illegal structure size %u\n",
			    le16_to_cpu(hdr->StructureSize));
		return 1;
	}

	command = le16_to_cpu(hdr->Command);
	if (command >= NUMBER_OF_SMB2_COMMANDS) {
		ksmbd_debug(SMB, "Illegal SMB2 command %d\n", command);
		return 1;
	}

	if (smb2_req_struct_sizes[command] != pdu->StructureSize2) {
		if (command != SMB2_OPLOCK_BREAK_HE &&
		    (hdr->Status == 0 || pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE)) {
			/* error packets have 9 byte structure size */
			ksmbd_debug(SMB,
				    "Illegal request 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) != OP_BREAK_STRUCT_SIZE_20 &&
			   le16_to_cpu(pdu->StructureSize2) != OP_BREAK_STRUCT_SIZE_21) {
			/* special case for SMB2.1 lease break message */
			ksmbd_debug(SMB,
				    "Illegal request size %d for oplock break\n",
				    le16_to_cpu(pdu->StructureSize2));
			return 1;
		}
	}

	if (smb2_calc_size(hdr, &clc_len))
		return 1;

	if (len != clc_len) {
		/* client can return one byte more due to implied bcc[0] */
		if (clc_len == len + 1)
			goto validate_credit;

		/*
		 * Some windows servers (win2016) will pad also the final
		 * PDU in a compound to 8 bytes.
		 */
		if (ALIGN(clc_len, 8) == len)
			goto validate_credit;

		/*
		 * windows client also pad up to 8 bytes when compounding.
		 * If pad is longer than eight bytes, log the server behavior
		 * (once), since may indicate a problem but allow it and
		 * continue since the frame is parseable.
		 */
		if (clc_len < len) {
			ksmbd_debug(SMB,
				    "cli req padded more than expected. Length %d not %d for cmd:%d mid:%llu\n",
				    len, clc_len, command,
				    le64_to_cpu(hdr->MessageId));
			goto validate_credit;
		}

		ksmbd_debug(SMB,
			    "cli req too short, len %d not %d. cmd:%d mid:%llu\n",
			    len, clc_len, command,
			    le64_to_cpu(hdr->MessageId));

		return 1;
	}

validate_credit:
	if ((work->conn->vals->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU) &&
	    smb2_validate_credit_charge(work->conn, hdr)) {
		work->conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
		return 1;
	}

	return 0;
}

int smb2_negotiate_request(struct ksmbd_work *work)
{
	return ksmbd_smb_negotiate_common(work, SMB2_NEGOTIATE_HE);
}
Commit	Line	Data
e2f34481 NJ	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
	4	* Copyright (C) 2018 Samsung Electronics Co., Ltd.
	5	*/
	6
	7	#include "glob.h"
	8	#include "nterr.h"
	9	#include "smb2pdu.h"
	10	#include "smb_common.h"
	11	#include "smbstatus.h"
	12	#include "mgmt/user_session.h"
	13	#include "connection.h"
	14
	15	static int check_smb2_hdr(struct smb2_hdr *hdr)
	16	{
	17	/*
	18	* Make sure that this really is an SMB, that it is a response.
	19	*/
	20	if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
	21	return 1;
	22	return 0;
	23	}
	24
	25	/*
	26	* The following table defines the expected "StructureSize" of SMB2 requests
	27	* in order by SMB2 command. This is similar to "wct" in SMB/CIFS requests.
	28	*
	29	* Note that commands are defined in smb2pdu.h in le16 but the array below is
	30	* indexed by command in host byte order
	31	*/
	32	static const __le16 smb2_req_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
	33	/* SMB2_NEGOTIATE */ cpu_to_le16(36),
	34	/* SMB2_SESSION_SETUP */ cpu_to_le16(25),
	35	/* SMB2_LOGOFF */ cpu_to_le16(4),
	36	/* SMB2_TREE_CONNECT */ cpu_to_le16(9),
	37	/* SMB2_TREE_DISCONNECT */ cpu_to_le16(4),
	38	/* SMB2_CREATE */ cpu_to_le16(57),
	39	/* SMB2_CLOSE */ cpu_to_le16(24),
	40	/* SMB2_FLUSH */ cpu_to_le16(24),
	41	/* SMB2_READ */ cpu_to_le16(49),
	42	/* SMB2_WRITE */ cpu_to_le16(49),
	43	/* SMB2_LOCK */ cpu_to_le16(48),
	44	/* SMB2_IOCTL */ cpu_to_le16(57),
	45	/* SMB2_CANCEL */ cpu_to_le16(4),
	46	/* SMB2_ECHO */ cpu_to_le16(4),
	47	/* SMB2_QUERY_DIRECTORY */ cpu_to_le16(33),
	48	/* SMB2_CHANGE_NOTIFY */ cpu_to_le16(32),
	49	/* SMB2_QUERY_INFO */ cpu_to_le16(41),
	50	/* SMB2_SET_INFO */ cpu_to_le16(33),
	51	/* use 44 for lease break */
	52	/* SMB2_OPLOCK_BREAK */ cpu_to_le16(36)
	53	};
	54
	55	/*
	56	* The size of the variable area depends on the offset and length fields
	57	* located in different fields for various SMB2 requests. SMB2 requests
	58	* with no variable length info, show an offset of zero for the offset field.
	59	*/
	60	static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
	61	/* SMB2_NEGOTIATE */ true,
	62	/* SMB2_SESSION_SETUP */ true,
	63	/* SMB2_LOGOFF */ false,
	64	/* SMB2_TREE_CONNECT */ true,
65	/* SMB2_TREE_DISCONNECT */ false,
66	/* SMB2_CREATE */ true,
67	/* SMB2_CLOSE */ false,
68	/* SMB2_FLUSH */ false,
69	/* SMB2_READ */ true,
70	/* SMB2_WRITE */ true,
71	/* SMB2_LOCK */ true,
72	/* SMB2_IOCTL */ true,
73	/* SMB2_CANCEL / false, / BB CHECK this not listed in documentation */
74	/* SMB2_ECHO */ false,
75	/* SMB2_QUERY_DIRECTORY */ true,
76	/* SMB2_CHANGE_NOTIFY */ false,
77	/* SMB2_QUERY_INFO */ true,
78	/* SMB2_SET_INFO */ true,
79	/* SMB2_OPLOCK_BREAK */ false
80	};
81
82	/*
c2e99d47 NJ	83	* Set length of the data area and the offset to arguments.
c2e99d47 NJ	84	* if they are invalid, return error.
e2f34481	85	*/
c2e99d47 NJ	86	static int smb2_get_data_area_len(unsigned int off, unsigned int len,
c2e99d47 NJ	87	struct smb2_hdr *hdr)
e2f34481	88	{
c2e99d47 NJ	89	int ret = 0;
c2e99d47 NJ	90
e2f34481 NJ	91	*off = 0;
	92	*len = 0;
	93
	94	/* error reqeusts do not have data area */
	95	if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
64b39f4a	96	(((struct smb2_err_rsp *)hdr)->StructureSize) == SMB2_ERROR_STRUCTURE_SIZE2_LE)
c2e99d47	97	return ret;
e2f34481 NJ	98
	99	/*
	100	* Following commands have data areas so we have to get the location
	101	* of the data buffer offset and data buffer length for the particular
	102	* command.
	103	*/
	104	switch (hdr->Command) {
	105	case SMB2_SESSION_SETUP:
64b39f4a NJ	106	off = le16_to_cpu(((struct smb2_sess_setup_req )hdr)->SecurityBufferOffset);
64b39f4a NJ	107	len = le16_to_cpu(((struct smb2_sess_setup_req )hdr)->SecurityBufferLength);
e2f34481 NJ	108	break;
e2f34481 NJ	109	case SMB2_TREE_CONNECT:
64b39f4a NJ	110	off = le16_to_cpu(((struct smb2_tree_connect_req )hdr)->PathOffset);
64b39f4a NJ	111	len = le16_to_cpu(((struct smb2_tree_connect_req )hdr)->PathLength);
e2f34481 NJ	112	break;
	113	case SMB2_CREATE:
	114	{
	115	if (((struct smb2_create_req *)hdr)->CreateContextsLength) {
	116	off = le32_to_cpu(((struct smb2_create_req )
	117	hdr)->CreateContextsOffset);
	118	len = le32_to_cpu(((struct smb2_create_req )
	119	hdr)->CreateContextsLength);
	120	break;
	121	}
	122
64b39f4a NJ	123	off = le16_to_cpu(((struct smb2_create_req )hdr)->NameOffset);
64b39f4a NJ	124	len = le16_to_cpu(((struct smb2_create_req )hdr)->NameLength);
e2f34481 NJ	125	break;
	126	}
	127	case SMB2_QUERY_INFO:
64b39f4a NJ	128	off = le16_to_cpu(((struct smb2_query_info_req )hdr)->InputBufferOffset);
64b39f4a NJ	129	len = le32_to_cpu(((struct smb2_query_info_req )hdr)->InputBufferLength);
e2f34481 NJ	130	break;
e2f34481 NJ	131	case SMB2_SET_INFO:
64b39f4a NJ	132	off = le16_to_cpu(((struct smb2_set_info_req )hdr)->BufferOffset);
64b39f4a NJ	133	len = le32_to_cpu(((struct smb2_set_info_req )hdr)->BufferLength);
e2f34481 NJ	134	break;
e2f34481 NJ	135	case SMB2_READ:
64b39f4a NJ	136	off = le16_to_cpu(((struct smb2_read_req )hdr)->ReadChannelInfoOffset);
64b39f4a NJ	137	len = le16_to_cpu(((struct smb2_read_req )hdr)->ReadChannelInfoLength);
e2f34481 NJ	138	break;
	139	case SMB2_WRITE:
	140	if (((struct smb2_write_req *)hdr)->DataOffset) {
64b39f4a NJ	141	off = le16_to_cpu(((struct smb2_write_req )hdr)->DataOffset);
64b39f4a NJ	142	len = le32_to_cpu(((struct smb2_write_req )hdr)->Length);
e2f34481 NJ	143	break;
	144	}
	145
64b39f4a NJ	146	off = le16_to_cpu(((struct smb2_write_req )hdr)->WriteChannelInfoOffset);
64b39f4a NJ	147	len = le16_to_cpu(((struct smb2_write_req )hdr)->WriteChannelInfoLength);
e2f34481 NJ	148	break;
e2f34481 NJ	149	case SMB2_QUERY_DIRECTORY:
64b39f4a NJ	150	off = le16_to_cpu(((struct smb2_query_directory_req )hdr)->FileNameOffset);
64b39f4a NJ	151	len = le16_to_cpu(((struct smb2_query_directory_req )hdr)->FileNameLength);
e2f34481 NJ	152	break;
	153	case SMB2_LOCK:
	154	{
	155	int lock_count;
	156
	157	/*
	158	* smb2_lock request size is 48 included single
	159	* smb2_lock_element structure size.
	160	*/
64b39f4a	161	lock_count = le16_to_cpu(((struct smb2_lock_req *)hdr)->LockCount) - 1;
e2f34481 NJ	162	if (lock_count > 0) {
	163	*off = __SMB2_HEADER_STRUCTURE_SIZE + 48;
	164	len = sizeof(struct smb2_lock_element) lock_count;
	165	}
	166	break;
	167	}
	168	case SMB2_IOCTL:
64b39f4a	169	off = le32_to_cpu(((struct smb2_ioctl_req )hdr)->InputOffset);
e2f34481	170	len = le32_to_cpu(((struct smb2_ioctl_req )hdr)->InputCount);
e2f34481 NJ	171	break;
	172	default:
	173	ksmbd_debug(SMB, "no length check for command\n");
	174	break;
	175	}
	176
e2f34481	177	if (*off > 4096) {
c2e99d47 NJ	178	ksmbd_debug(SMB, "offset %d too large\n", *off);
	179	ret = -EINVAL;
	180	} else if ((u64)off + len > MAX_STREAM_PROT_LEN) {
	181	ksmbd_debug(SMB, "Request is larger than maximum stream protocol length(%u): %llu\n",
	182	MAX_STREAM_PROT_LEN, (u64)off + len);
	183	ret = -EINVAL;
e2f34481 NJ	184	}
e2f34481 NJ	185
c2e99d47	186	return ret;
e2f34481 NJ	187	}
	188
	189	/*
	190	* Calculate the size of the SMB message based on the fixed header
	191	* portion, the number of word parameters and the data portion of the message.
	192	*/
c2e99d47	193	static int smb2_calc_size(void buf, unsigned int len)
e2f34481 NJ	194	{
	195	struct smb2_pdu pdu = (struct smb2_pdu )buf;
	196	struct smb2_hdr *hdr = &pdu->hdr;
c2e99d47 NJ	197	unsigned int offset; /* the offset from the beginning of SMB to data area */
	198	unsigned int data_length; /* the length of the variable length data area */
	199	int ret;
	200
e2f34481	201	/* Structure Size has already been checked to make sure it is 64 */
c2e99d47	202	*len = le16_to_cpu(hdr->StructureSize);
e2f34481 NJ	203
	204	/*
	205	* StructureSize2, ie length of fixed parameter area has already
	206	* been checked to make sure it is the correct length.
	207	*/
c2e99d47 NJ	208	*len += le16_to_cpu(pdu->StructureSize2);
	209	/*
	210	* StructureSize2 of smb2_lock pdu is set to 48, indicating
	211	* the size of smb2 lock request with single smb2_lock_element
	212	* regardless of number of locks. Subtract single
	213	* smb2_lock_element for correct buffer size check.
	214	*/
	215	if (hdr->Command == SMB2_LOCK)
	216	*len -= sizeof(struct smb2_lock_element);
e2f34481 NJ	217
	218	if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false)
	219	goto calc_size_exit;
	220
c2e99d47 NJ	221	ret = smb2_get_data_area_len(&offset, &data_length, hdr);
	222	if (ret)
	223	return ret;
	224	ksmbd_debug(SMB, "SMB2 data length %u offset %u\n", data_length,
070fb21e	225	offset);
e2f34481 NJ	226
	227	if (data_length > 0) {
	228	/*
	229	* Check to make sure that data area begins after fixed area,
	230	* Note that last byte of the fixed area is part of data area
	231	* for some commands, typically those with odd StructureSize,
	232	* so we must add one to the calculation.
	233	*/
c2e99d47	234	if (offset + 1 < *len) {
e2f34481	235	ksmbd_debug(SMB,
c2e99d47 NJ	236	"data area offset %d overlaps SMB2 header %u\n",
	237	offset + 1, *len);
	238	return -EINVAL;
	239	}
	240
	241	*len = offset + data_length;
e2f34481	242	}
c2e99d47	243
e2f34481	244	calc_size_exit:
c2e99d47 NJ	245	ksmbd_debug(SMB, "SMB2 len %u\n", *len);
c2e99d47 NJ	246	return 0;
e2f34481 NJ	247	}
	248
	249	static inline int smb2_query_info_req_len(struct smb2_query_info_req *h)
	250	{
	251	return le32_to_cpu(h->InputBufferLength) +
	252	le32_to_cpu(h->OutputBufferLength);
	253	}
	254
	255	static inline int smb2_set_info_req_len(struct smb2_set_info_req *h)
	256	{
	257	return le32_to_cpu(h->BufferLength);
	258	}
	259
	260	static inline int smb2_read_req_len(struct smb2_read_req *h)
	261	{
	262	return le32_to_cpu(h->Length);
	263	}
	264
	265	static inline int smb2_write_req_len(struct smb2_write_req *h)
	266	{
	267	return le32_to_cpu(h->Length);
	268	}
	269
	270	static inline int smb2_query_dir_req_len(struct smb2_query_directory_req *h)
	271	{
	272	return le32_to_cpu(h->OutputBufferLength);
	273	}
	274
	275	static inline int smb2_ioctl_req_len(struct smb2_ioctl_req *h)
	276	{
	277	return le32_to_cpu(h->InputCount) +
	278	le32_to_cpu(h->OutputCount);
	279	}
	280
	281	static inline int smb2_ioctl_resp_len(struct smb2_ioctl_req *h)
	282	{
	283	return le32_to_cpu(h->MaxInputResponse) +
	284	le32_to_cpu(h->MaxOutputResponse);
	285	}
	286
bf8acc9e HL	287	static int smb2_validate_credit_charge(struct ksmbd_conn *conn,
bf8acc9e HL	288	struct smb2_hdr *hdr)
e2f34481	289	{
bf8acc9e HL	290	unsigned int req_len = 0, expect_resp_len = 0, calc_credit_num, max_len;
bf8acc9e HL	291	unsigned short credit_charge = le16_to_cpu(hdr->CreditCharge);
e2f34481	292	void *__hdr = hdr;
bf8acc9e	293	int ret;
e2f34481 NJ	294
	295	switch (hdr->Command) {
	296	case SMB2_QUERY_INFO:
	297	req_len = smb2_query_info_req_len(__hdr);
	298	break;
	299	case SMB2_SET_INFO:
	300	req_len = smb2_set_info_req_len(__hdr);
	301	break;
	302	case SMB2_READ:
	303	req_len = smb2_read_req_len(__hdr);
	304	break;
	305	case SMB2_WRITE:
	306	req_len = smb2_write_req_len(__hdr);
	307	break;
	308	case SMB2_QUERY_DIRECTORY:
	309	req_len = smb2_query_dir_req_len(__hdr);
	310	break;
	311	case SMB2_IOCTL:
	312	req_len = smb2_ioctl_req_len(__hdr);
	313	expect_resp_len = smb2_ioctl_resp_len(__hdr);
	314	break;
bf8acc9e	315	case SMB2_CANCEL:
e2f34481	316	return 0;
bf8acc9e HL	317	default:
	318	req_len = 1;
	319	break;
e2f34481 NJ	320	}
e2f34481 NJ	321
bf8acc9e HL	322	credit_charge = max_t(unsigned short, credit_charge, 1);
bf8acc9e HL	323	max_len = max_t(unsigned int, req_len, expect_resp_len);
e2f34481	324	calc_credit_num = DIV_ROUND_UP(max_len, SMB2_MAX_BUFFER_SIZE);
a5a25a11 MM	325
a5a25a11 MM	326	if (credit_charge < calc_credit_num) {
bf8acc9e HL	327	ksmbd_debug(SMB, "Insufficient credit charge, given: %d, needed: %d\n",
	328	credit_charge, calc_credit_num);
	329	return 1;
	330	} else if (credit_charge > conn->max_credits) {
	331	ksmbd_debug(SMB, "Too large credit charge: %d\n", credit_charge);
e2f34481 NJ	332	return 1;
	333	}
	334
bf8acc9e HL	335	spin_lock(&conn->credits_lock);
	336	if (credit_charge <= conn->total_credits) {
	337	conn->total_credits -= credit_charge;
	338	ret = 0;
	339	} else {
	340	ksmbd_debug(SMB, "Insufficient credits granted, given: %u, granted: %u\n",
	341	credit_charge, conn->total_credits);
	342	ret = 1;
	343	}
	344	spin_unlock(&conn->credits_lock);
	345	return ret;
e2f34481 NJ	346	}
	347
	348	int ksmbd_smb2_check_message(struct ksmbd_work *work)
	349	{
e5066499	350	struct smb2_pdu *pdu = work->request_buf;
e2f34481 NJ	351	struct smb2_hdr *hdr = &pdu->hdr;
	352	int command;
	353	__u32 clc_len; /* calculated length */
	354	__u32 len = get_rfc1002_len(pdu);
	355
	356	if (work->next_smb2_rcv_hdr_off) {
8a893315	357	pdu = ksmbd_req_buf_next(work);
e2f34481 NJ	358	hdr = &pdu->hdr;
	359	}
	360
64b39f4a	361	if (le32_to_cpu(hdr->NextCommand) > 0) {
e2f34481	362	len = le32_to_cpu(hdr->NextCommand);
64b39f4a	363	} else if (work->next_smb2_rcv_hdr_off) {
e2f34481 NJ	364	len -= work->next_smb2_rcv_hdr_off;
	365	len = round_up(len, 8);
	366	}
	367
	368	if (check_smb2_hdr(hdr))
	369	return 1;
	370
	371	if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
	372	ksmbd_debug(SMB, "Illegal structure size %u\n",
070fb21e	373	le16_to_cpu(hdr->StructureSize));
e2f34481 NJ	374	return 1;
	375	}
	376
	377	command = le16_to_cpu(hdr->Command);
	378	if (command >= NUMBER_OF_SMB2_COMMANDS) {
	379	ksmbd_debug(SMB, "Illegal SMB2 command %d\n", command);
	380	return 1;
	381	}
	382
	383	if (smb2_req_struct_sizes[command] != pdu->StructureSize2) {
64b39f4a NJ	384	if (command != SMB2_OPLOCK_BREAK_HE &&
64b39f4a NJ	385	(hdr->Status == 0 \|\| pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE)) {
e2f34481 NJ	386	/* error packets have 9 byte structure size */
e2f34481 NJ	387	ksmbd_debug(SMB,
070fb21e NJ	388	"Illegal request size %u for command %d\n",
070fb21e NJ	389	le16_to_cpu(pdu->StructureSize2), command);
e2f34481	390	return 1;
64b39f4a NJ	391	} else if (command == SMB2_OPLOCK_BREAK_HE &&
	392	hdr->Status == 0 &&
	393	le16_to_cpu(pdu->StructureSize2) != OP_BREAK_STRUCT_SIZE_20 &&
	394	le16_to_cpu(pdu->StructureSize2) != OP_BREAK_STRUCT_SIZE_21) {
e2f34481 NJ	395	/* special case for SMB2.1 lease break message */
e2f34481 NJ	396	ksmbd_debug(SMB,
070fb21e NJ	397	"Illegal request size %d for oplock break\n",
070fb21e NJ	398	le16_to_cpu(pdu->StructureSize2));
e2f34481 NJ	399	return 1;
	400	}
	401	}
	402
c2e99d47 NJ	403	if (smb2_calc_size(hdr, &clc_len))
	404	return 1;
	405
e2f34481	406	if (len != clc_len) {
c2e99d47	407	/* client can return one byte more due to implied bcc[0] */
e2f34481	408	if (clc_len == len + 1)
7a334887	409	goto validate_credit;
e2f34481 NJ	410
	411	/*
	412	* Some windows servers (win2016) will pad also the final
	413	* PDU in a compound to 8 bytes.
	414	*/
	415	if (ALIGN(clc_len, 8) == len)
7a334887	416	goto validate_credit;
e2f34481 NJ	417
	418	/*
	419	* windows client also pad up to 8 bytes when compounding.
	420	* If pad is longer than eight bytes, log the server behavior
	421	* (once), since may indicate a problem but allow it and
	422	* continue since the frame is parseable.
	423	*/
	424	if (clc_len < len) {
	425	ksmbd_debug(SMB,
070fb21e NJ	426	"cli req padded more than expected. Length %d not %d for cmd:%d mid:%llu\n",
	427	len, clc_len, command,
	428	le64_to_cpu(hdr->MessageId));
7a334887	429	goto validate_credit;
e2f34481 NJ	430	}
e2f34481 NJ	431
e2f34481	432	ksmbd_debug(SMB,
070fb21e NJ	433	"cli req too short, len %d not %d. cmd:%d mid:%llu\n",
	434	len, clc_len, command,
	435	le64_to_cpu(hdr->MessageId));
e2f34481 NJ	436
	437	return 1;
	438	}
	439
7a334887 RB	440	validate_credit:
	441	if ((work->conn->vals->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU) &&
	442	smb2_validate_credit_charge(work->conn, hdr)) {
	443	work->conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER);
	444	return 1;
	445	}
	446
67307023	447	return 0;
e2f34481 NJ	448	}
	449
	450	int smb2_negotiate_request(struct ksmbd_work *work)
	451	{
	452	return ksmbd_smb_negotiate_common(work, SMB2_NEGOTIATE_HE);
	453	}