474 lines
14 KiB
C
474 lines
14 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org>
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* Copyright (C) 2018 Samsung Electronics Co., Ltd.
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*/
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#include "glob.h"
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#include "nterr.h"
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#include "smb_common.h"
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#include "smbstatus.h"
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#include "mgmt/user_session.h"
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#include "connection.h"
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static int check_smb2_hdr(struct smb2_hdr *hdr)
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{
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/*
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* Make sure that this really is an SMB, that it is a response.
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*/
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if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
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return 1;
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return 0;
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}
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/*
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* The following table defines the expected "StructureSize" of SMB2 requests
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* in order by SMB2 command. This is similar to "wct" in SMB/CIFS requests.
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*
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* Note that commands are defined in smb2pdu.h in le16 but the array below is
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* indexed by command in host byte order
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*/
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static const __le16 smb2_req_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
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/* SMB2_NEGOTIATE */ cpu_to_le16(36),
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/* SMB2_SESSION_SETUP */ cpu_to_le16(25),
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/* SMB2_LOGOFF */ cpu_to_le16(4),
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/* SMB2_TREE_CONNECT */ cpu_to_le16(9),
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/* SMB2_TREE_DISCONNECT */ cpu_to_le16(4),
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/* SMB2_CREATE */ cpu_to_le16(57),
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/* SMB2_CLOSE */ cpu_to_le16(24),
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/* SMB2_FLUSH */ cpu_to_le16(24),
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/* SMB2_READ */ cpu_to_le16(49),
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/* SMB2_WRITE */ cpu_to_le16(49),
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/* SMB2_LOCK */ cpu_to_le16(48),
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/* SMB2_IOCTL */ cpu_to_le16(57),
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/* SMB2_CANCEL */ cpu_to_le16(4),
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/* SMB2_ECHO */ cpu_to_le16(4),
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/* SMB2_QUERY_DIRECTORY */ cpu_to_le16(33),
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/* SMB2_CHANGE_NOTIFY */ cpu_to_le16(32),
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/* SMB2_QUERY_INFO */ cpu_to_le16(41),
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/* SMB2_SET_INFO */ cpu_to_le16(33),
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/* use 44 for lease break */
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/* SMB2_OPLOCK_BREAK */ cpu_to_le16(36)
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};
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/*
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* The size of the variable area depends on the offset and length fields
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* located in different fields for various SMB2 requests. SMB2 requests
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* with no variable length info, show an offset of zero for the offset field.
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*/
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static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
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/* SMB2_NEGOTIATE */ true,
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/* SMB2_SESSION_SETUP */ true,
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/* SMB2_LOGOFF */ false,
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/* SMB2_TREE_CONNECT */ true,
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/* SMB2_TREE_DISCONNECT */ false,
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/* SMB2_CREATE */ true,
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/* SMB2_CLOSE */ false,
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/* SMB2_FLUSH */ false,
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/* SMB2_READ */ true,
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/* SMB2_WRITE */ true,
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/* SMB2_LOCK */ true,
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/* SMB2_IOCTL */ true,
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/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
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/* SMB2_ECHO */ false,
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/* SMB2_QUERY_DIRECTORY */ true,
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/* SMB2_CHANGE_NOTIFY */ false,
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/* SMB2_QUERY_INFO */ true,
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/* SMB2_SET_INFO */ true,
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/* SMB2_OPLOCK_BREAK */ false
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};
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/*
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* Set length of the data area and the offset to arguments.
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* if they are invalid, return error.
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*/
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static int smb2_get_data_area_len(unsigned int *off, unsigned int *len,
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struct smb2_hdr *hdr)
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{
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int ret = 0;
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*off = 0;
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*len = 0;
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/*
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* Following commands have data areas so we have to get the location
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* of the data buffer offset and data buffer length for the particular
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* command.
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*/
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switch (hdr->Command) {
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case SMB2_SESSION_SETUP:
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*off = le16_to_cpu(((struct smb2_sess_setup_req *)hdr)->SecurityBufferOffset);
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*len = le16_to_cpu(((struct smb2_sess_setup_req *)hdr)->SecurityBufferLength);
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break;
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case SMB2_TREE_CONNECT:
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*off = max_t(unsigned short int,
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le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathOffset),
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offsetof(struct smb2_tree_connect_req, Buffer));
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*len = le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathLength);
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break;
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case SMB2_CREATE:
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{
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unsigned short int name_off =
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max_t(unsigned short int,
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le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset),
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offsetof(struct smb2_create_req, Buffer));
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unsigned short int name_len =
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le16_to_cpu(((struct smb2_create_req *)hdr)->NameLength);
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if (((struct smb2_create_req *)hdr)->CreateContextsLength) {
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*off = le32_to_cpu(((struct smb2_create_req *)
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hdr)->CreateContextsOffset);
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*len = le32_to_cpu(((struct smb2_create_req *)
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hdr)->CreateContextsLength);
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if (!name_len)
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break;
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if (name_off + name_len < (u64)*off + *len)
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break;
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}
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*off = name_off;
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*len = name_len;
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break;
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}
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case SMB2_QUERY_INFO:
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*off = max_t(unsigned int,
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le16_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferOffset),
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offsetof(struct smb2_query_info_req, Buffer));
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*len = le32_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferLength);
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break;
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case SMB2_SET_INFO:
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*off = max_t(unsigned int,
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le16_to_cpu(((struct smb2_set_info_req *)hdr)->BufferOffset),
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offsetof(struct smb2_set_info_req, Buffer));
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*len = le32_to_cpu(((struct smb2_set_info_req *)hdr)->BufferLength);
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break;
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case SMB2_READ:
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*off = le16_to_cpu(((struct smb2_read_req *)hdr)->ReadChannelInfoOffset);
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*len = le16_to_cpu(((struct smb2_read_req *)hdr)->ReadChannelInfoLength);
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break;
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case SMB2_WRITE:
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if (((struct smb2_write_req *)hdr)->DataOffset ||
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((struct smb2_write_req *)hdr)->Length) {
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*off = max_t(unsigned short int,
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le16_to_cpu(((struct smb2_write_req *)hdr)->DataOffset),
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offsetof(struct smb2_write_req, Buffer));
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*len = le32_to_cpu(((struct smb2_write_req *)hdr)->Length);
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break;
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}
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*off = le16_to_cpu(((struct smb2_write_req *)hdr)->WriteChannelInfoOffset);
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*len = le16_to_cpu(((struct smb2_write_req *)hdr)->WriteChannelInfoLength);
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break;
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case SMB2_QUERY_DIRECTORY:
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*off = max_t(unsigned short int,
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le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameOffset),
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offsetof(struct smb2_query_directory_req, Buffer));
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*len = le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameLength);
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break;
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case SMB2_LOCK:
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{
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unsigned short lock_count;
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lock_count = le16_to_cpu(((struct smb2_lock_req *)hdr)->LockCount);
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if (lock_count > 0) {
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*off = offsetof(struct smb2_lock_req, locks);
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*len = sizeof(struct smb2_lock_element) * lock_count;
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}
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break;
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}
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case SMB2_IOCTL:
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*off = max_t(unsigned int,
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le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputOffset),
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offsetof(struct smb2_ioctl_req, Buffer));
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*len = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputCount);
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break;
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default:
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ksmbd_debug(SMB, "no length check for command\n");
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break;
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}
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if (*off > 4096) {
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ksmbd_debug(SMB, "offset %d too large\n", *off);
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ret = -EINVAL;
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} else if ((u64)*off + *len > MAX_STREAM_PROT_LEN) {
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ksmbd_debug(SMB, "Request is larger than maximum stream protocol length(%u): %llu\n",
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MAX_STREAM_PROT_LEN, (u64)*off + *len);
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ret = -EINVAL;
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}
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return ret;
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}
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/*
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* Calculate the size of the SMB message based on the fixed header
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* portion, the number of word parameters and the data portion of the message.
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*/
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static int smb2_calc_size(void *buf, unsigned int *len)
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{
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struct smb2_pdu *pdu = (struct smb2_pdu *)buf;
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struct smb2_hdr *hdr = &pdu->hdr;
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unsigned int offset; /* the offset from the beginning of SMB to data area */
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unsigned int data_length; /* the length of the variable length data area */
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int ret;
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/* Structure Size has already been checked to make sure it is 64 */
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*len = le16_to_cpu(hdr->StructureSize);
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/*
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* StructureSize2, ie length of fixed parameter area has already
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* been checked to make sure it is the correct length.
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*/
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*len += le16_to_cpu(pdu->StructureSize2);
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/*
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* StructureSize2 of smb2_lock pdu is set to 48, indicating
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* the size of smb2 lock request with single smb2_lock_element
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* regardless of number of locks. Subtract single
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* smb2_lock_element for correct buffer size check.
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*/
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if (hdr->Command == SMB2_LOCK)
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*len -= sizeof(struct smb2_lock_element);
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if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false)
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goto calc_size_exit;
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ret = smb2_get_data_area_len(&offset, &data_length, hdr);
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if (ret)
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return ret;
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ksmbd_debug(SMB, "SMB2 data length %u offset %u\n", data_length,
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offset);
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if (data_length > 0) {
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/*
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* Check to make sure that data area begins after fixed area,
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* Note that last byte of the fixed area is part of data area
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* for some commands, typically those with odd StructureSize,
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* so we must add one to the calculation.
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*/
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if (offset + 1 < *len) {
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ksmbd_debug(SMB,
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"data area offset %d overlaps SMB2 header %u\n",
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offset + 1, *len);
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return -EINVAL;
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}
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*len = offset + data_length;
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}
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calc_size_exit:
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ksmbd_debug(SMB, "SMB2 len %u\n", *len);
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return 0;
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}
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static inline int smb2_query_info_req_len(struct smb2_query_info_req *h)
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{
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return le32_to_cpu(h->InputBufferLength) +
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le32_to_cpu(h->OutputBufferLength);
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}
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static inline int smb2_set_info_req_len(struct smb2_set_info_req *h)
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{
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return le32_to_cpu(h->BufferLength);
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}
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static inline int smb2_read_req_len(struct smb2_read_req *h)
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{
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return le32_to_cpu(h->Length);
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}
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static inline int smb2_write_req_len(struct smb2_write_req *h)
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{
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return le32_to_cpu(h->Length);
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}
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static inline int smb2_query_dir_req_len(struct smb2_query_directory_req *h)
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{
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return le32_to_cpu(h->OutputBufferLength);
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}
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static inline int smb2_ioctl_req_len(struct smb2_ioctl_req *h)
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{
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return le32_to_cpu(h->InputCount) +
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le32_to_cpu(h->OutputCount);
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}
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static inline int smb2_ioctl_resp_len(struct smb2_ioctl_req *h)
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{
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return le32_to_cpu(h->MaxInputResponse) +
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le32_to_cpu(h->MaxOutputResponse);
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}
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static int smb2_validate_credit_charge(struct ksmbd_conn *conn,
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struct smb2_hdr *hdr)
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{
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unsigned int req_len = 0, expect_resp_len = 0, calc_credit_num, max_len;
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unsigned short credit_charge = le16_to_cpu(hdr->CreditCharge);
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void *__hdr = hdr;
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int ret = 0;
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switch (hdr->Command) {
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case SMB2_QUERY_INFO:
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req_len = smb2_query_info_req_len(__hdr);
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break;
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case SMB2_SET_INFO:
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req_len = smb2_set_info_req_len(__hdr);
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break;
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case SMB2_READ:
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req_len = smb2_read_req_len(__hdr);
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break;
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case SMB2_WRITE:
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req_len = smb2_write_req_len(__hdr);
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break;
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case SMB2_QUERY_DIRECTORY:
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req_len = smb2_query_dir_req_len(__hdr);
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break;
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case SMB2_IOCTL:
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req_len = smb2_ioctl_req_len(__hdr);
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expect_resp_len = smb2_ioctl_resp_len(__hdr);
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break;
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case SMB2_CANCEL:
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return 0;
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default:
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req_len = 1;
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break;
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}
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credit_charge = max_t(unsigned short, credit_charge, 1);
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max_len = max_t(unsigned int, req_len, expect_resp_len);
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calc_credit_num = DIV_ROUND_UP(max_len, SMB2_MAX_BUFFER_SIZE);
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if (credit_charge < calc_credit_num) {
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ksmbd_debug(SMB, "Insufficient credit charge, given: %d, needed: %d\n",
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credit_charge, calc_credit_num);
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return 1;
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} else if (credit_charge > conn->vals->max_credits) {
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ksmbd_debug(SMB, "Too large credit charge: %d\n", credit_charge);
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return 1;
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}
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spin_lock(&conn->credits_lock);
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if (credit_charge > conn->total_credits) {
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ksmbd_debug(SMB, "Insufficient credits granted, given: %u, granted: %u\n",
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credit_charge, conn->total_credits);
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ret = 1;
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}
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if ((u64)conn->outstanding_credits + credit_charge > conn->total_credits) {
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ksmbd_debug(SMB, "Limits exceeding the maximum allowable outstanding requests, given : %u, pending : %u\n",
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credit_charge, conn->outstanding_credits);
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ret = 1;
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} else
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conn->outstanding_credits += credit_charge;
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spin_unlock(&conn->credits_lock);
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return ret;
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}
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int ksmbd_smb2_check_message(struct ksmbd_work *work)
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{
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struct smb2_pdu *pdu = ksmbd_req_buf_next(work);
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struct smb2_hdr *hdr = &pdu->hdr;
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int command;
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__u32 clc_len; /* calculated length */
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__u32 len = get_rfc1002_len(work->request_buf);
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__u32 req_struct_size, next_cmd = le32_to_cpu(hdr->NextCommand);
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if ((u64)work->next_smb2_rcv_hdr_off + next_cmd > len) {
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pr_err("next command(%u) offset exceeds smb msg size\n",
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next_cmd);
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return 1;
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}
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if (next_cmd > 0)
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len = next_cmd;
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else if (work->next_smb2_rcv_hdr_off)
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len -= work->next_smb2_rcv_hdr_off;
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if (check_smb2_hdr(hdr))
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return 1;
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if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
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ksmbd_debug(SMB, "Illegal structure size %u\n",
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le16_to_cpu(hdr->StructureSize));
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return 1;
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}
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command = le16_to_cpu(hdr->Command);
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if (command >= NUMBER_OF_SMB2_COMMANDS) {
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ksmbd_debug(SMB, "Illegal SMB2 command %d\n", command);
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return 1;
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}
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if (smb2_req_struct_sizes[command] != pdu->StructureSize2) {
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if (!(command == SMB2_OPLOCK_BREAK_HE &&
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(le16_to_cpu(pdu->StructureSize2) == OP_BREAK_STRUCT_SIZE_20 ||
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le16_to_cpu(pdu->StructureSize2) == OP_BREAK_STRUCT_SIZE_21))) {
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/* special case for SMB2.1 lease break message */
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ksmbd_debug(SMB,
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"Illegal request size %u for command %d\n",
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le16_to_cpu(pdu->StructureSize2), command);
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return 1;
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}
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}
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req_struct_size = le16_to_cpu(pdu->StructureSize2) +
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__SMB2_HEADER_STRUCTURE_SIZE;
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if (command == SMB2_LOCK_HE)
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req_struct_size -= sizeof(struct smb2_lock_element);
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if (req_struct_size > len + 1)
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return 1;
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if (smb2_calc_size(hdr, &clc_len))
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return 1;
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if (len != clc_len) {
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/* client can return one byte more due to implied bcc[0] */
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if (clc_len == len + 1)
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goto validate_credit;
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/*
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* Some windows servers (win2016) will pad also the final
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* PDU in a compound to 8 bytes.
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*/
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if (ALIGN(clc_len, 8) == len)
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goto validate_credit;
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/*
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* SMB2 NEGOTIATE request will be validated when message
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* handling proceeds.
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*/
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if (command == SMB2_NEGOTIATE_HE)
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goto validate_credit;
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/*
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* Allow a message that padded to 8byte boundary.
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* Linux 4.19.217 with smb 3.0.2 are sometimes
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* sending messages where the cls_len is exactly
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* 8 bytes less than len.
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*/
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if (clc_len < len && (len - clc_len) <= 8)
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goto validate_credit;
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pr_err_ratelimited(
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"cli req too short, len %d not %d. cmd:%d mid:%llu\n",
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len, clc_len, command,
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le64_to_cpu(hdr->MessageId));
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return 1;
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}
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validate_credit:
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if ((work->conn->vals->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU) &&
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smb2_validate_credit_charge(work->conn, hdr))
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return 1;
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return 0;
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}
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|
|
|
int smb2_negotiate_request(struct ksmbd_work *work)
|
|
{
|
|
return ksmbd_smb_negotiate_common(work, SMB2_NEGOTIATE_HE);
|
|
}
|