--- /dev/null
+/*
+ * 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
+ cERROR(1, "Received Request not response");
+ }
+ } else { /* bad signature or mid */
+ if (*(__le32 *)hdr->ProtocolId != SMB2_PROTO_NUMBER)
+ 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 __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 */
+ cFYI(1, "%s length: 0x%x, smb_buf_length: 0x%x", __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 < 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 (hdr->StructureSize != SMB2_HEADER_SIZE) {
+ 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] != pdu->StructureSize2) {
+ if (hdr->Status == 0 ||
+ pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2) {
+ /* error packets have 9 byte structure size */
+ cERROR(1, "Illegal response size %u for command %d",
+ le16_to_cpu(pdu->StructureSize2), command);
+ return 1;
+ }
+ }
+
+ if (4 + len != length) {
+ cERROR(1, "Total length %u RFC1002 length %u mismatch mid %llu",
+ length, 4 + len, mid);
+ return 1;
+ }
+
+ clc_len = smb2_calc_size(hdr);
+
+ if (4 + len != clc_len) {
+ cFYI(1, "Calculated size %u length %u mismatch mid %llu",
+ 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 && 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:
+ 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) {
+ cERROR(1, "offset %d too large, data area ignored", *off);
+ *len = 0;
+ *off = 0;
+ } else if (*off < 0) {
+ cERROR(1, "negative offset %d to data invalid ignore data area",
+ *off);
+ *off = 0;
+ *len = 0;
+ } else if (*len < 0) {
+ cERROR(1, "negative data length %d invalid, data area ignored",
+ *len);
+ *len = 0;
+ } else if (*len > 128 * 1024) {
+ cERROR(1, "data area larger than 128K: %d", *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(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 offset %d overlaps SMB2 header %d",
+ offset + 4 + 1, len);
+ data_length = 0;
+ } else {
+ len = 4 + offset + data_length;
+ }
+ }
+calc_size_exit:
+ cFYI(1, "SMB2 len %d", len);
+ return len;
+}
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff