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smb2pdu.c
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smb2pdu.c
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/*
* fs/cifs/smb2pdu.c
*
* Copyright (C) International Business Machines Corp., 2009, 2013
* Etersoft, 2012
* Author(s): Steve French ([email protected])
* Pavel Shilovsky ([email protected]) 2012
*
* Contains the routines for constructing the SMB2 PDUs themselves
*
* 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
*/
/* SMB2 PDU handling routines here - except for leftovers (eg session setup) */
/* Note that there are handle based routines which must be */
/* treated slightly differently for reconnection purposes since we never */
/* want to reuse a stale file handle and only the caller knows the file info */
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/vfs.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/uaccess.h>
#include <linux/uuid.h>
#include <linux/pagemap.h>
#include <linux/xattr.h>
#include "smb2pdu.h"
#include "cifsglob.h"
#include "cifsacl.h"
#include "cifsproto.h"
#include "smb2proto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "ntlmssp.h"
#include "smb2status.h"
#include "smb2glob.h"
#include "cifspdu.h"
#include "cifs_spnego.h"
#include "smbdirect.h"
#include "trace.h"
#ifdef CONFIG_CIFS_DFS_UPCALL
#include "dfs_cache.h"
#endif
/*
* 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 int smb2_req_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
/* SMB2_NEGOTIATE */ 36,
/* SMB2_SESSION_SETUP */ 25,
/* SMB2_LOGOFF */ 4,
/* SMB2_TREE_CONNECT */ 9,
/* SMB2_TREE_DISCONNECT */ 4,
/* SMB2_CREATE */ 57,
/* SMB2_CLOSE */ 24,
/* SMB2_FLUSH */ 24,
/* SMB2_READ */ 49,
/* SMB2_WRITE */ 49,
/* SMB2_LOCK */ 48,
/* SMB2_IOCTL */ 57,
/* SMB2_CANCEL */ 4,
/* SMB2_ECHO */ 4,
/* SMB2_QUERY_DIRECTORY */ 33,
/* SMB2_CHANGE_NOTIFY */ 32,
/* SMB2_QUERY_INFO */ 41,
/* SMB2_SET_INFO */ 33,
/* SMB2_OPLOCK_BREAK */ 24 /* BB this is 36 for LEASE_BREAK variant */
};
int smb3_encryption_required(const struct cifs_tcon *tcon)
{
if (!tcon)
return 0;
if ((tcon->ses->session_flags & SMB2_SESSION_FLAG_ENCRYPT_DATA) ||
(tcon->share_flags & SHI1005_FLAGS_ENCRYPT_DATA))
return 1;
if (tcon->seal &&
(tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION))
return 1;
return 0;
}
static void
smb2_hdr_assemble(struct smb2_sync_hdr *shdr, __le16 smb2_cmd,
const struct cifs_tcon *tcon)
{
shdr->ProtocolId = SMB2_PROTO_NUMBER;
shdr->StructureSize = cpu_to_le16(64);
shdr->Command = smb2_cmd;
if (tcon && tcon->ses && tcon->ses->server) {
struct TCP_Server_Info *server = tcon->ses->server;
spin_lock(&server->req_lock);
/* Request up to 2 credits but don't go over the limit. */
if (server->credits >= server->max_credits)
shdr->CreditRequest = cpu_to_le16(0);
else
shdr->CreditRequest = cpu_to_le16(
min_t(int, server->max_credits -
server->credits, 2));
spin_unlock(&server->req_lock);
} else {
shdr->CreditRequest = cpu_to_le16(2);
}
shdr->ProcessId = cpu_to_le32((__u16)current->tgid);
if (!tcon)
goto out;
/* GLOBAL_CAP_LARGE_MTU will only be set if dialect > SMB2.02 */
/* See sections 2.2.4 and 3.2.4.1.5 of MS-SMB2 */
if ((tcon->ses) && (tcon->ses->server) &&
(tcon->ses->server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
shdr->CreditCharge = cpu_to_le16(1);
/* else CreditCharge MBZ */
shdr->TreeId = tcon->tid;
/* Uid is not converted */
if (tcon->ses)
shdr->SessionId = tcon->ses->Suid;
/*
* If we would set SMB2_FLAGS_DFS_OPERATIONS on open we also would have
* to pass the path on the Open SMB prefixed by \\server\share.
* Not sure when we would need to do the augmented path (if ever) and
* setting this flag breaks the SMB2 open operation since it is
* illegal to send an empty path name (without \\server\share prefix)
* when the DFS flag is set in the SMB open header. We could
* consider setting the flag on all operations other than open
* but it is safer to net set it for now.
*/
/* if (tcon->share_flags & SHI1005_FLAGS_DFS)
shdr->Flags |= SMB2_FLAGS_DFS_OPERATIONS; */
if (tcon->ses && tcon->ses->server && tcon->ses->server->sign &&
!smb3_encryption_required(tcon))
shdr->Flags |= SMB2_FLAGS_SIGNED;
out:
return;
}
#ifdef CONFIG_CIFS_DFS_UPCALL
static int __smb2_reconnect(const struct nls_table *nlsc,
struct cifs_tcon *tcon)
{
int rc;
struct dfs_cache_tgt_list tl;
struct dfs_cache_tgt_iterator *it = NULL;
char *tree;
const char *tcp_host;
size_t tcp_host_len;
const char *dfs_host;
size_t dfs_host_len;
tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
if (!tree)
return -ENOMEM;
if (tcon->ipc) {
snprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$",
tcon->ses->server->hostname);
rc = SMB2_tcon(0, tcon->ses, tree, tcon, nlsc);
goto out;
}
if (!tcon->dfs_path) {
rc = SMB2_tcon(0, tcon->ses, tcon->treeName, tcon, nlsc);
goto out;
}
rc = dfs_cache_noreq_find(tcon->dfs_path + 1, NULL, &tl);
if (rc)
goto out;
extract_unc_hostname(tcon->ses->server->hostname, &tcp_host,
&tcp_host_len);
for (it = dfs_cache_get_tgt_iterator(&tl); it;
it = dfs_cache_get_next_tgt(&tl, it)) {
const char *tgt = dfs_cache_get_tgt_name(it);
extract_unc_hostname(tgt, &dfs_host, &dfs_host_len);
if (dfs_host_len != tcp_host_len
|| strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
cifs_dbg(FYI, "%s: skipping %.*s, doesn't match %.*s",
__func__,
(int)dfs_host_len, dfs_host,
(int)tcp_host_len, tcp_host);
continue;
}
snprintf(tree, MAX_TREE_SIZE, "\\%s", tgt);
rc = SMB2_tcon(0, tcon->ses, tree, tcon, nlsc);
if (!rc)
break;
if (rc == -EREMOTE)
break;
}
if (!rc) {
if (it)
rc = dfs_cache_noreq_update_tgthint(tcon->dfs_path + 1,
it);
else
rc = -ENOENT;
}
dfs_cache_free_tgts(&tl);
out:
kfree(tree);
return rc;
}
#else
static inline int __smb2_reconnect(const struct nls_table *nlsc,
struct cifs_tcon *tcon)
{
return SMB2_tcon(0, tcon->ses, tcon->treeName, tcon, nlsc);
}
#endif
static int
smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
{
int rc;
struct nls_table *nls_codepage;
struct cifs_ses *ses;
struct TCP_Server_Info *server;
int retries;
/*
* SMB2s NegProt, SessSetup, Logoff do not have tcon yet so
* check for tcp and smb session status done differently
* for those three - in the calling routine.
*/
if (tcon == NULL)
return 0;
if (smb2_command == SMB2_TREE_CONNECT)
return 0;
if (tcon->tidStatus == CifsExiting) {
/*
* only tree disconnect, open, and write,
* (and ulogoff which does not have tcon)
* are allowed as we start force umount.
*/
if ((smb2_command != SMB2_WRITE) &&
(smb2_command != SMB2_CREATE) &&
(smb2_command != SMB2_TREE_DISCONNECT)) {
cifs_dbg(FYI, "can not send cmd %d while umounting\n",
smb2_command);
return -ENODEV;
}
}
if ((!tcon->ses) || (tcon->ses->status == CifsExiting) ||
(!tcon->ses->server))
return -EIO;
ses = tcon->ses;
server = ses->server;
retries = server->nr_targets;
/*
* Give demultiplex thread up to 10 seconds to each target available for
* reconnect -- should be greater than cifs socket timeout which is 7
* seconds.
*/
while (server->tcpStatus == CifsNeedReconnect) {
/*
* Return to caller for TREE_DISCONNECT and LOGOFF and CLOSE
* here since they are implicitly done when session drops.
*/
switch (smb2_command) {
/*
* BB Should we keep oplock break and add flush to exceptions?
*/
case SMB2_TREE_DISCONNECT:
case SMB2_CANCEL:
case SMB2_CLOSE:
case SMB2_OPLOCK_BREAK:
return -EAGAIN;
}
rc = wait_event_interruptible_timeout(server->response_q,
(server->tcpStatus != CifsNeedReconnect),
10 * HZ);
if (rc < 0) {
cifs_dbg(FYI, "%s: aborting reconnect due to a received"
" signal by the process\n", __func__);
return -ERESTARTSYS;
}
/* are we still trying to reconnect? */
if (server->tcpStatus != CifsNeedReconnect)
break;
if (--retries)
continue;
/*
* on "soft" mounts we wait once. Hard mounts keep
* retrying until process is killed or server comes
* back on-line
*/
if (!tcon->retry) {
cifs_dbg(FYI, "gave up waiting on reconnect in smb_init\n");
return -EHOSTDOWN;
}
retries = server->nr_targets;
}
if (!tcon->ses->need_reconnect && !tcon->need_reconnect)
return 0;
nls_codepage = load_nls_default();
/*
* need to prevent multiple threads trying to simultaneously reconnect
* the same SMB session
*/
mutex_lock(&tcon->ses->session_mutex);
/*
* Recheck after acquire mutex. If another thread is negotiating
* and the server never sends an answer the socket will be closed
* and tcpStatus set to reconnect.
*/
if (server->tcpStatus == CifsNeedReconnect) {
rc = -EHOSTDOWN;
mutex_unlock(&tcon->ses->session_mutex);
goto out;
}
rc = cifs_negotiate_protocol(0, tcon->ses);
if (!rc && tcon->ses->need_reconnect)
rc = cifs_setup_session(0, tcon->ses, nls_codepage);
if (rc || !tcon->need_reconnect) {
mutex_unlock(&tcon->ses->session_mutex);
goto out;
}
cifs_mark_open_files_invalid(tcon);
if (tcon->use_persistent)
tcon->need_reopen_files = true;
rc = __smb2_reconnect(nls_codepage, tcon);
mutex_unlock(&tcon->ses->session_mutex);
cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
if (rc) {
/* If sess reconnected but tcon didn't, something strange ... */
printk_once(KERN_WARNING "reconnect tcon failed rc = %d\n", rc);
goto out;
}
if (smb2_command != SMB2_INTERNAL_CMD)
queue_delayed_work(cifsiod_wq, &server->reconnect, 0);
atomic_inc(&tconInfoReconnectCount);
out:
/*
* Check if handle based operation so we know whether we can continue
* or not without returning to caller to reset file handle.
*/
/*
* BB Is flush done by server on drop of tcp session? Should we special
* case it and skip above?
*/
switch (smb2_command) {
case SMB2_FLUSH:
case SMB2_READ:
case SMB2_WRITE:
case SMB2_LOCK:
case SMB2_IOCTL:
case SMB2_QUERY_DIRECTORY:
case SMB2_CHANGE_NOTIFY:
case SMB2_QUERY_INFO:
case SMB2_SET_INFO:
rc = -EAGAIN;
}
unload_nls(nls_codepage);
return rc;
}
static void
fill_small_buf(__le16 smb2_command, struct cifs_tcon *tcon, void *buf,
unsigned int *total_len)
{
struct smb2_sync_pdu *spdu = (struct smb2_sync_pdu *)buf;
/* lookup word count ie StructureSize from table */
__u16 parmsize = smb2_req_struct_sizes[le16_to_cpu(smb2_command)];
/*
* smaller than SMALL_BUFFER_SIZE but bigger than fixed area of
* largest operations (Create)
*/
memset(buf, 0, 256);
smb2_hdr_assemble(&spdu->sync_hdr, smb2_command, tcon);
spdu->StructureSize2 = cpu_to_le16(parmsize);
*total_len = parmsize + sizeof(struct smb2_sync_hdr);
}
/*
* Allocate and return pointer to an SMB request hdr, and set basic
* SMB information in the SMB header. If the return code is zero, this
* function must have filled in request_buf pointer.
*/
static int
smb2_plain_req_init(__le16 smb2_command, struct cifs_tcon *tcon,
void **request_buf, unsigned int *total_len)
{
int rc;
rc = smb2_reconnect(smb2_command, tcon);
if (rc)
return rc;
/* BB eventually switch this to SMB2 specific small buf size */
if (smb2_command == SMB2_SET_INFO)
*request_buf = cifs_buf_get();
else
*request_buf = cifs_small_buf_get();
if (*request_buf == NULL) {
/* BB should we add a retry in here if not a writepage? */
return -ENOMEM;
}
fill_small_buf(smb2_command, tcon,
(struct smb2_sync_hdr *)(*request_buf),
total_len);
if (tcon != NULL) {
uint16_t com_code = le16_to_cpu(smb2_command);
cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_sent[com_code]);
cifs_stats_inc(&tcon->num_smbs_sent);
}
return rc;
}
#define SMB2_PREAUTH_INTEGRITY_CAPABILITIES cpu_to_le16(1)
#define SMB2_ENCRYPTION_CAPABILITIES cpu_to_le16(2)
#define SMB2_POSIX_EXTENSIONS_AVAILABLE cpu_to_le16(0x100)
static void
build_preauth_ctxt(struct smb2_preauth_neg_context *pneg_ctxt)
{
pneg_ctxt->ContextType = SMB2_PREAUTH_INTEGRITY_CAPABILITIES;
pneg_ctxt->DataLength = cpu_to_le16(38);
pneg_ctxt->HashAlgorithmCount = cpu_to_le16(1);
pneg_ctxt->SaltLength = cpu_to_le16(SMB311_SALT_SIZE);
get_random_bytes(pneg_ctxt->Salt, SMB311_SALT_SIZE);
pneg_ctxt->HashAlgorithms = SMB2_PREAUTH_INTEGRITY_SHA512;
}
static void
build_encrypt_ctxt(struct smb2_encryption_neg_context *pneg_ctxt)
{
pneg_ctxt->ContextType = SMB2_ENCRYPTION_CAPABILITIES;
pneg_ctxt->DataLength = cpu_to_le16(4); /* Cipher Count + le16 cipher */
pneg_ctxt->CipherCount = cpu_to_le16(1);
/* pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_GCM;*/ /* not supported yet */
pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_CCM;
}
static void
build_posix_ctxt(struct smb2_posix_neg_context *pneg_ctxt)
{
pneg_ctxt->ContextType = SMB2_POSIX_EXTENSIONS_AVAILABLE;
pneg_ctxt->DataLength = cpu_to_le16(POSIX_CTXT_DATA_LEN);
}
static void
assemble_neg_contexts(struct smb2_negotiate_req *req,
unsigned int *total_len)
{
char *pneg_ctxt = (char *)req;
unsigned int ctxt_len;
if (*total_len > 200) {
/* In case length corrupted don't want to overrun smb buffer */
cifs_dbg(VFS, "Bad frame length assembling neg contexts\n");
return;
}
/*
* round up total_len of fixed part of SMB3 negotiate request to 8
* byte boundary before adding negotiate contexts
*/
*total_len = roundup(*total_len, 8);
pneg_ctxt = (*total_len) + (char *)req;
req->NegotiateContextOffset = cpu_to_le32(*total_len);
build_preauth_ctxt((struct smb2_preauth_neg_context *)pneg_ctxt);
ctxt_len = DIV_ROUND_UP(sizeof(struct smb2_preauth_neg_context), 8) * 8;
*total_len += ctxt_len;
pneg_ctxt += ctxt_len;
build_encrypt_ctxt((struct smb2_encryption_neg_context *)pneg_ctxt);
ctxt_len = DIV_ROUND_UP(sizeof(struct smb2_encryption_neg_context), 8) * 8;
*total_len += ctxt_len;
pneg_ctxt += ctxt_len;
build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
*total_len += sizeof(struct smb2_posix_neg_context);
req->NegotiateContextCount = cpu_to_le16(3);
}
static void decode_preauth_context(struct smb2_preauth_neg_context *ctxt)
{
unsigned int len = le16_to_cpu(ctxt->DataLength);
/* If invalid preauth context warn but use what we requested, SHA-512 */
if (len < MIN_PREAUTH_CTXT_DATA_LEN) {
printk_once(KERN_WARNING "server sent bad preauth context\n");
return;
}
if (le16_to_cpu(ctxt->HashAlgorithmCount) != 1)
printk_once(KERN_WARNING "illegal SMB3 hash algorithm count\n");
if (ctxt->HashAlgorithms != SMB2_PREAUTH_INTEGRITY_SHA512)
printk_once(KERN_WARNING "unknown SMB3 hash algorithm\n");
}
static int decode_encrypt_ctx(struct TCP_Server_Info *server,
struct smb2_encryption_neg_context *ctxt)
{
unsigned int len = le16_to_cpu(ctxt->DataLength);
cifs_dbg(FYI, "decode SMB3.11 encryption neg context of len %d\n", len);
if (len < MIN_ENCRYPT_CTXT_DATA_LEN) {
printk_once(KERN_WARNING "server sent bad crypto ctxt len\n");
return -EINVAL;
}
if (le16_to_cpu(ctxt->CipherCount) != 1) {
printk_once(KERN_WARNING "illegal SMB3.11 cipher count\n");
return -EINVAL;
}
cifs_dbg(FYI, "SMB311 cipher type:%d\n", le16_to_cpu(ctxt->Ciphers[0]));
if ((ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_CCM) &&
(ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_GCM)) {
printk_once(KERN_WARNING "invalid SMB3.11 cipher returned\n");
return -EINVAL;
}
server->cipher_type = ctxt->Ciphers[0];
server->capabilities |= SMB2_GLOBAL_CAP_ENCRYPTION;
return 0;
}
static int smb311_decode_neg_context(struct smb2_negotiate_rsp *rsp,
struct TCP_Server_Info *server,
unsigned int len_of_smb)
{
struct smb2_neg_context *pctx;
unsigned int offset = le32_to_cpu(rsp->NegotiateContextOffset);
unsigned int ctxt_cnt = le16_to_cpu(rsp->NegotiateContextCount);
unsigned int len_of_ctxts, i;
int rc = 0;
cifs_dbg(FYI, "decoding %d negotiate contexts\n", ctxt_cnt);
if (len_of_smb <= offset) {
cifs_dbg(VFS, "Invalid response: negotiate context offset\n");
return -EINVAL;
}
len_of_ctxts = len_of_smb - offset;
for (i = 0; i < ctxt_cnt; i++) {
int clen;
/* check that offset is not beyond end of SMB */
if (len_of_ctxts == 0)
break;
if (len_of_ctxts < sizeof(struct smb2_neg_context))
break;
pctx = (struct smb2_neg_context *)(offset + (char *)rsp);
clen = le16_to_cpu(pctx->DataLength);
if (clen > len_of_ctxts)
break;
if (pctx->ContextType == SMB2_PREAUTH_INTEGRITY_CAPABILITIES)
decode_preauth_context(
(struct smb2_preauth_neg_context *)pctx);
else if (pctx->ContextType == SMB2_ENCRYPTION_CAPABILITIES)
rc = decode_encrypt_ctx(server,
(struct smb2_encryption_neg_context *)pctx);
else if (pctx->ContextType == SMB2_POSIX_EXTENSIONS_AVAILABLE)
server->posix_ext_supported = true;
else
cifs_dbg(VFS, "unknown negcontext of type %d ignored\n",
le16_to_cpu(pctx->ContextType));
if (rc)
break;
/* offsets must be 8 byte aligned */
clen = (clen + 7) & ~0x7;
offset += clen + sizeof(struct smb2_neg_context);
len_of_ctxts -= clen;
}
return rc;
}
static struct create_posix *
create_posix_buf(umode_t mode)
{
struct create_posix *buf;
buf = kzalloc(sizeof(struct create_posix),
GFP_KERNEL);
if (!buf)
return NULL;
buf->ccontext.DataOffset =
cpu_to_le16(offsetof(struct create_posix, Mode));
buf->ccontext.DataLength = cpu_to_le32(4);
buf->ccontext.NameOffset =
cpu_to_le16(offsetof(struct create_posix, Name));
buf->ccontext.NameLength = cpu_to_le16(16);
/* SMB2_CREATE_TAG_POSIX is "0x93AD25509CB411E7B42383DE968BCD7C" */
buf->Name[0] = 0x93;
buf->Name[1] = 0xAD;
buf->Name[2] = 0x25;
buf->Name[3] = 0x50;
buf->Name[4] = 0x9C;
buf->Name[5] = 0xB4;
buf->Name[6] = 0x11;
buf->Name[7] = 0xE7;
buf->Name[8] = 0xB4;
buf->Name[9] = 0x23;
buf->Name[10] = 0x83;
buf->Name[11] = 0xDE;
buf->Name[12] = 0x96;
buf->Name[13] = 0x8B;
buf->Name[14] = 0xCD;
buf->Name[15] = 0x7C;
buf->Mode = cpu_to_le32(mode);
cifs_dbg(FYI, "mode on posix create 0%o", mode);
return buf;
}
static int
add_posix_context(struct kvec *iov, unsigned int *num_iovec, umode_t mode)
{
struct smb2_create_req *req = iov[0].iov_base;
unsigned int num = *num_iovec;
iov[num].iov_base = create_posix_buf(mode);
if (iov[num].iov_base == NULL)
return -ENOMEM;
iov[num].iov_len = sizeof(struct create_posix);
if (!req->CreateContextsOffset)
req->CreateContextsOffset = cpu_to_le32(
sizeof(struct smb2_create_req) +
iov[num - 1].iov_len);
le32_add_cpu(&req->CreateContextsLength, sizeof(struct create_posix));
*num_iovec = num + 1;
return 0;
}
/*
*
* SMB2 Worker functions follow:
*
* The general structure of the worker functions is:
* 1) Call smb2_init (assembles SMB2 header)
* 2) Initialize SMB2 command specific fields in fixed length area of SMB
* 3) Call smb_sendrcv2 (sends request on socket and waits for response)
* 4) Decode SMB2 command specific fields in the fixed length area
* 5) Decode variable length data area (if any for this SMB2 command type)
* 6) Call free smb buffer
* 7) return
*
*/
int
SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
{
struct smb_rqst rqst;
struct smb2_negotiate_req *req;
struct smb2_negotiate_rsp *rsp;
struct kvec iov[1];
struct kvec rsp_iov;
int rc = 0;
int resp_buftype;
struct TCP_Server_Info *server = ses->server;
int blob_offset, blob_length;
char *security_blob;
int flags = CIFS_NEG_OP;
unsigned int total_len;
cifs_dbg(FYI, "Negotiate protocol\n");
if (!server) {
WARN(1, "%s: server is NULL!\n", __func__);
return -EIO;
}
rc = smb2_plain_req_init(SMB2_NEGOTIATE, NULL, (void **) &req, &total_len);
if (rc)
return rc;
req->sync_hdr.SessionId = 0;
memset(server->preauth_sha_hash, 0, SMB2_PREAUTH_HASH_SIZE);
memset(ses->preauth_sha_hash, 0, SMB2_PREAUTH_HASH_SIZE);
if (strcmp(ses->server->vals->version_string,
SMB3ANY_VERSION_STRING) == 0) {
req->Dialects[0] = cpu_to_le16(SMB30_PROT_ID);
req->Dialects[1] = cpu_to_le16(SMB302_PROT_ID);
req->DialectCount = cpu_to_le16(2);
total_len += 4;
} else if (strcmp(ses->server->vals->version_string,
SMBDEFAULT_VERSION_STRING) == 0) {
req->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
req->Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
req->Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
req->Dialects[3] = cpu_to_le16(SMB311_PROT_ID);
req->DialectCount = cpu_to_le16(4);
total_len += 8;
} else {
/* otherwise send specific dialect */
req->Dialects[0] = cpu_to_le16(ses->server->vals->protocol_id);
req->DialectCount = cpu_to_le16(1);
total_len += 2;
}
/* only one of SMB2 signing flags may be set in SMB2 request */
if (ses->sign)
req->SecurityMode = cpu_to_le16(SMB2_NEGOTIATE_SIGNING_REQUIRED);
else if (global_secflags & CIFSSEC_MAY_SIGN)
req->SecurityMode = cpu_to_le16(SMB2_NEGOTIATE_SIGNING_ENABLED);
else
req->SecurityMode = 0;
req->Capabilities = cpu_to_le32(ses->server->vals->req_capabilities);
/* ClientGUID must be zero for SMB2.02 dialect */
if (ses->server->vals->protocol_id == SMB20_PROT_ID)
memset(req->ClientGUID, 0, SMB2_CLIENT_GUID_SIZE);
else {
memcpy(req->ClientGUID, server->client_guid,
SMB2_CLIENT_GUID_SIZE);
if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
(strcmp(ses->server->vals->version_string,
SMBDEFAULT_VERSION_STRING) == 0))
assemble_neg_contexts(req, &total_len);
}
iov[0].iov_base = (char *)req;
iov[0].iov_len = total_len;
memset(&rqst, 0, sizeof(struct smb_rqst));
rqst.rq_iov = iov;
rqst.rq_nvec = 1;
rc = cifs_send_recv(xid, ses, &rqst, &resp_buftype, flags, &rsp_iov);
cifs_small_buf_release(req);
rsp = (struct smb2_negotiate_rsp *)rsp_iov.iov_base;
/*
* No tcon so can't do
* cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_fail[SMB2...]);
*/
if (rc == -EOPNOTSUPP) {
cifs_dbg(VFS, "Dialect not supported by server. Consider "
"specifying vers=1.0 or vers=2.0 on mount for accessing"
" older servers\n");
goto neg_exit;
} else if (rc != 0)
goto neg_exit;
if (strcmp(ses->server->vals->version_string,
SMB3ANY_VERSION_STRING) == 0) {
if (rsp->DialectRevision == cpu_to_le16(SMB20_PROT_ID)) {
cifs_dbg(VFS,
"SMB2 dialect returned but not requested\n");
return -EIO;
} else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID)) {
cifs_dbg(VFS,
"SMB2.1 dialect returned but not requested\n");
return -EIO;
}
} else if (strcmp(ses->server->vals->version_string,
SMBDEFAULT_VERSION_STRING) == 0) {
if (rsp->DialectRevision == cpu_to_le16(SMB20_PROT_ID)) {
cifs_dbg(VFS,
"SMB2 dialect returned but not requested\n");
return -EIO;
} else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID)) {
/* ops set to 3.0 by default for default so update */
ses->server->ops = &smb21_operations;
} else if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID))
ses->server->ops = &smb311_operations;
} else if (le16_to_cpu(rsp->DialectRevision) !=
ses->server->vals->protocol_id) {
/* if requested single dialect ensure returned dialect matched */
cifs_dbg(VFS, "Illegal 0x%x dialect returned: not requested\n",
le16_to_cpu(rsp->DialectRevision));
return -EIO;
}
cifs_dbg(FYI, "mode 0x%x\n", rsp->SecurityMode);
if (rsp->DialectRevision == cpu_to_le16(SMB20_PROT_ID))
cifs_dbg(FYI, "negotiated smb2.0 dialect\n");
else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID))
cifs_dbg(FYI, "negotiated smb2.1 dialect\n");
else if (rsp->DialectRevision == cpu_to_le16(SMB30_PROT_ID))
cifs_dbg(FYI, "negotiated smb3.0 dialect\n");
else if (rsp->DialectRevision == cpu_to_le16(SMB302_PROT_ID))
cifs_dbg(FYI, "negotiated smb3.02 dialect\n");
else if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID))
cifs_dbg(FYI, "negotiated smb3.1.1 dialect\n");
else {
cifs_dbg(VFS, "Illegal dialect returned by server 0x%x\n",
le16_to_cpu(rsp->DialectRevision));
rc = -EIO;
goto neg_exit;
}
server->dialect = le16_to_cpu(rsp->DialectRevision);
/*
* Keep a copy of the hash after negprot. This hash will be
* the starting hash value for all sessions made from this
* server.
*/
memcpy(server->preauth_sha_hash, ses->preauth_sha_hash,
SMB2_PREAUTH_HASH_SIZE);
/* SMB2 only has an extended negflavor */
server->negflavor = CIFS_NEGFLAVOR_EXTENDED;
/* set it to the maximum buffer size value we can send with 1 credit */
server->maxBuf = min_t(unsigned int, le32_to_cpu(rsp->MaxTransactSize),
SMB2_MAX_BUFFER_SIZE);
server->max_read = le32_to_cpu(rsp->MaxReadSize);
server->max_write = le32_to_cpu(rsp->MaxWriteSize);
server->sec_mode = le16_to_cpu(rsp->SecurityMode);
if ((server->sec_mode & SMB2_SEC_MODE_FLAGS_ALL) != server->sec_mode)
cifs_dbg(FYI, "Server returned unexpected security mode 0x%x\n",
server->sec_mode);
server->capabilities = le32_to_cpu(rsp->Capabilities);
/* Internal types */
server->capabilities |= SMB2_NT_FIND | SMB2_LARGE_FILES;
security_blob = smb2_get_data_area_len(&blob_offset, &blob_length,
(struct smb2_sync_hdr *)rsp);
/*
* See MS-SMB2 section 2.2.4: if no blob, client picks default which
* for us will be
* ses->sectype = RawNTLMSSP;
* but for time being this is our only auth choice so doesn't matter.
* We just found a server which sets blob length to zero expecting raw.
*/
if (blob_length == 0) {
cifs_dbg(FYI, "missing security blob on negprot\n");
server->sec_ntlmssp = true;
}
rc = cifs_enable_signing(server, ses->sign);
if (rc)
goto neg_exit;
if (blob_length) {
rc = decode_negTokenInit(security_blob, blob_length, server);
if (rc == 1)
rc = 0;
else if (rc == 0)
rc = -EIO;
}
if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID)) {
if (rsp->NegotiateContextCount)
rc = smb311_decode_neg_context(rsp, server,
rsp_iov.iov_len);
else
cifs_dbg(VFS, "Missing expected negotiate contexts\n");
}
neg_exit:
free_rsp_buf(resp_buftype, rsp);
return rc;
}
int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon)
{
int rc;
struct validate_negotiate_info_req *pneg_inbuf;
struct validate_negotiate_info_rsp *pneg_rsp = NULL;
u32 rsplen;
u32 inbuflen; /* max of 4 dialects */
cifs_dbg(FYI, "validate negotiate\n");
/* In SMB3.11 preauth integrity supersedes validate negotiate */
if (tcon->ses->server->dialect == SMB311_PROT_ID)
return 0;
/*
* validation ioctl must be signed, so no point sending this if we
* can not sign it (ie are not known user). Even if signing is not
* required (enabled but not negotiated), in those cases we selectively
* sign just this, the first and only signed request on a connection.
* Having validation of negotiate info helps reduce attack vectors.
*/
if (tcon->ses->session_flags & SMB2_SESSION_FLAG_IS_GUEST)
return 0; /* validation requires signing */
if (tcon->ses->user_name == NULL) {
cifs_dbg(FYI, "Can't validate negotiate: null user mount\n");
return 0; /* validation requires signing */
}
if (tcon->ses->session_flags & SMB2_SESSION_FLAG_IS_NULL)
cifs_dbg(VFS, "Unexpected null user (anonymous) auth flag sent by server\n");
pneg_inbuf = kmalloc(sizeof(*pneg_inbuf), GFP_NOFS);
if (!pneg_inbuf)
return -ENOMEM;
pneg_inbuf->Capabilities =
cpu_to_le32(tcon->ses->server->vals->req_capabilities);
memcpy(pneg_inbuf->Guid, tcon->ses->server->client_guid,
SMB2_CLIENT_GUID_SIZE);
if (tcon->ses->sign)
pneg_inbuf->SecurityMode =
cpu_to_le16(SMB2_NEGOTIATE_SIGNING_REQUIRED);
else if (global_secflags & CIFSSEC_MAY_SIGN)
pneg_inbuf->SecurityMode =
cpu_to_le16(SMB2_NEGOTIATE_SIGNING_ENABLED);
else
pneg_inbuf->SecurityMode = 0;
if (strcmp(tcon->ses->server->vals->version_string,
SMB3ANY_VERSION_STRING) == 0) {
pneg_inbuf->Dialects[0] = cpu_to_le16(SMB30_PROT_ID);
pneg_inbuf->Dialects[1] = cpu_to_le16(SMB302_PROT_ID);
pneg_inbuf->DialectCount = cpu_to_le16(2);
/* structure is big enough for 3 dialects, sending only 2 */
inbuflen = sizeof(*pneg_inbuf) -
(2 * sizeof(pneg_inbuf->Dialects[0]));
} else if (strcmp(tcon->ses->server->vals->version_string,
SMBDEFAULT_VERSION_STRING) == 0) {
pneg_inbuf->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
pneg_inbuf->Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
pneg_inbuf->Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
pneg_inbuf->Dialects[3] = cpu_to_le16(SMB311_PROT_ID);
pneg_inbuf->DialectCount = cpu_to_le16(4);
/* structure is big enough for 3 dialects */
inbuflen = sizeof(*pneg_inbuf);
} else {
/* otherwise specific dialect was requested */
pneg_inbuf->Dialects[0] =
cpu_to_le16(tcon->ses->server->vals->protocol_id);
pneg_inbuf->DialectCount = cpu_to_le16(1);
/* structure is big enough for 3 dialects, sending only 1 */
inbuflen = sizeof(*pneg_inbuf) -
sizeof(pneg_inbuf->Dialects[0]) * 2;
}
rc = SMB2_ioctl(xid, tcon, NO_FILE_ID, NO_FILE_ID,
FSCTL_VALIDATE_NEGOTIATE_INFO, true /* is_fsctl */,
(char *)pneg_inbuf, inbuflen, (char **)&pneg_rsp, &rsplen);
if (rc != 0) {
cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc);
rc = -EIO;
goto out_free_inbuf;
}
rc = -EIO;
if (rsplen != sizeof(*pneg_rsp)) {
cifs_dbg(VFS, "invalid protocol negotiate response size: %d\n",
rsplen);