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smb2pdu.c
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smb2pdu.c
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// SPDX-License-Identifier: LGPL-2.1
/*
*
* Copyright (C) International Business Machines Corp., 2009, 2013
* Etersoft, 2012
* Author(s): Steve French (sfrench@us.ibm.com)
* Pavel Shilovsky (pshilovsky@samba.org) 2012
*
* Contains the routines for constructing the SMB2 PDUs themselves
*
*/
/* 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 "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 || !tcon->ses)
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_hdr *shdr, __le16 smb2_cmd,
const struct cifs_tcon *tcon,
struct TCP_Server_Info *server)
{
shdr->ProtocolId = SMB2_PROTO_NUMBER;
shdr->StructureSize = cpu_to_le16(64);
shdr->Command = smb2_cmd;
if (server) {
spin_lock(&server->req_lock);
/* Request up to 10 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, 10));
spin_unlock(&server->req_lock);
} else {
shdr->CreditRequest = cpu_to_le16(2);
}
shdr->Id.SyncId.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 (server && (server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
shdr->CreditCharge = cpu_to_le16(1);
/* else CreditCharge MBZ */
shdr->Id.SyncId.TreeId = cpu_to_le32(tcon->tid);
/* Uid is not converted */
if (tcon->ses)
shdr->SessionId = cpu_to_le64(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 (server && server->sign && !smb3_encryption_required(tcon))
shdr->Flags |= SMB2_FLAGS_SIGNED;
out:
return;
}
static int
smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon,
struct TCP_Server_Info *server)
{
int rc = 0;
struct nls_table *nls_codepage;
struct cifs_ses *ses;
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;
/*
* Need to also skip SMB2_IOCTL because it is used for checking nested dfs links in
* cifs_tree_connect().
*/
if (smb2_command == SMB2_TREE_CONNECT || smb2_command == SMB2_IOCTL)
return 0;
spin_lock(&cifs_tcp_ses_lock);
if (tcon->status == TID_EXITING) {
/*
* 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)) {
spin_unlock(&cifs_tcp_ses_lock);
cifs_dbg(FYI, "can not send cmd %d while umounting\n",
smb2_command);
return -ENODEV;
}
}
spin_unlock(&cifs_tcp_ses_lock);
if ((!tcon->ses) || (tcon->ses->ses_status == SES_EXITING) ||
(!tcon->ses->server) || !server)
return -EIO;
ses = tcon->ses;
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? */
spin_lock(&cifs_tcp_ses_lock);
if (server->tcpStatus != CifsNeedReconnect) {
spin_unlock(&cifs_tcp_ses_lock);
break;
}
spin_unlock(&cifs_tcp_ses_lock);
if (retries && --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;
}
spin_lock(&ses->chan_lock);
if (!cifs_chan_needs_reconnect(ses, server) && !tcon->need_reconnect) {
spin_unlock(&ses->chan_lock);
return 0;
}
spin_unlock(&ses->chan_lock);
cifs_dbg(FYI, "sess reconnect mask: 0x%lx, tcon reconnect: %d",
tcon->ses->chans_need_reconnect,
tcon->need_reconnect);
nls_codepage = load_nls_default();
/*
* 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.
*/
spin_lock(&cifs_tcp_ses_lock);
if (server->tcpStatus == CifsNeedReconnect) {
spin_unlock(&cifs_tcp_ses_lock);
rc = -EHOSTDOWN;
goto out;
}
spin_unlock(&cifs_tcp_ses_lock);
/*
* need to prevent multiple threads trying to simultaneously
* reconnect the same SMB session
*/
spin_lock(&ses->chan_lock);
if (!cifs_chan_needs_reconnect(ses, server)) {
spin_unlock(&ses->chan_lock);
/* this means that we only need to tree connect */
if (tcon->need_reconnect)
goto skip_sess_setup;
goto out;
}
spin_unlock(&ses->chan_lock);
mutex_lock(&ses->session_mutex);
rc = cifs_negotiate_protocol(0, ses, server);
if (!rc) {
rc = cifs_setup_session(0, ses, server, nls_codepage);
if ((rc == -EACCES) && !tcon->retry) {
mutex_unlock(&ses->session_mutex);
rc = -EHOSTDOWN;
goto failed;
} else if (rc) {
mutex_unlock(&ses->session_mutex);
goto out;
}
} else {
mutex_unlock(&ses->session_mutex);
goto out;
}
mutex_unlock(&ses->session_mutex);
skip_sess_setup:
mutex_lock(&ses->session_mutex);
if (!tcon->need_reconnect) {
mutex_unlock(&ses->session_mutex);
goto out;
}
cifs_mark_open_files_invalid(tcon);
if (tcon->use_persistent)
tcon->need_reopen_files = true;
rc = cifs_tree_connect(0, tcon, nls_codepage);
mutex_unlock(&ses->session_mutex);
cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
if (rc) {
/* If sess reconnected but tcon didn't, something strange ... */
pr_warn_once("reconnect tcon failed rc = %d\n", rc);
goto out;
}
if (smb2_command != SMB2_INTERNAL_CMD)
mod_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;
}
failed:
unload_nls(nls_codepage);
return rc;
}
static void
fill_small_buf(__le16 smb2_command, struct cifs_tcon *tcon,
struct TCP_Server_Info *server,
void *buf,
unsigned int *total_len)
{
struct smb2_pdu *spdu = (struct smb2_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->hdr, smb2_command, tcon, server);
spdu->StructureSize2 = cpu_to_le16(parmsize);
*total_len = parmsize + sizeof(struct smb2_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,
struct TCP_Server_Info *server,
void **request_buf, unsigned int *total_len)
{
/* 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, server,
(struct smb2_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 0;
}
static int smb2_plain_req_init(__le16 smb2_command, struct cifs_tcon *tcon,
struct TCP_Server_Info *server,
void **request_buf, unsigned int *total_len)
{
int rc;
rc = smb2_reconnect(smb2_command, tcon, server);
if (rc)
return rc;
return __smb2_plain_req_init(smb2_command, tcon, server, request_buf,
total_len);
}
static int smb2_ioctl_req_init(u32 opcode, struct cifs_tcon *tcon,
struct TCP_Server_Info *server,
void **request_buf, unsigned int *total_len)
{
/* Skip reconnect only for FSCTL_VALIDATE_NEGOTIATE_INFO IOCTLs */
if (opcode == FSCTL_VALIDATE_NEGOTIATE_INFO) {
return __smb2_plain_req_init(SMB2_IOCTL, tcon, server,
request_buf, total_len);
}
return smb2_plain_req_init(SMB2_IOCTL, tcon, server,
request_buf, total_len);
}
/* For explanation of negotiate contexts see MS-SMB2 section 2.2.3.1 */
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_compression_ctxt(struct smb2_compression_capabilities_context *pneg_ctxt)
{
pneg_ctxt->ContextType = SMB2_COMPRESSION_CAPABILITIES;
pneg_ctxt->DataLength =
cpu_to_le16(sizeof(struct smb2_compression_capabilities_context)
- sizeof(struct smb2_neg_context));
pneg_ctxt->CompressionAlgorithmCount = cpu_to_le16(3);
pneg_ctxt->CompressionAlgorithms[0] = SMB3_COMPRESS_LZ77;
pneg_ctxt->CompressionAlgorithms[1] = SMB3_COMPRESS_LZ77_HUFF;
pneg_ctxt->CompressionAlgorithms[2] = SMB3_COMPRESS_LZNT1;
}
static unsigned int
build_signing_ctxt(struct smb2_signing_capabilities *pneg_ctxt)
{
unsigned int ctxt_len = sizeof(struct smb2_signing_capabilities);
unsigned short num_algs = 1; /* number of signing algorithms sent */
pneg_ctxt->ContextType = SMB2_SIGNING_CAPABILITIES;
/*
* Context Data length must be rounded to multiple of 8 for some servers
*/
pneg_ctxt->DataLength = cpu_to_le16(DIV_ROUND_UP(
sizeof(struct smb2_signing_capabilities) -
sizeof(struct smb2_neg_context) +
(num_algs * 2 /* sizeof u16 */), 8) * 8);
pneg_ctxt->SigningAlgorithmCount = cpu_to_le16(num_algs);
pneg_ctxt->SigningAlgorithms[0] = cpu_to_le16(SIGNING_ALG_AES_CMAC);
ctxt_len += 2 /* sizeof le16 */ * num_algs;
ctxt_len = DIV_ROUND_UP(ctxt_len, 8) * 8;
return ctxt_len;
/* TBD add SIGNING_ALG_AES_GMAC and/or SIGNING_ALG_HMAC_SHA256 */
}
static void
build_encrypt_ctxt(struct smb2_encryption_neg_context *pneg_ctxt)
{
pneg_ctxt->ContextType = SMB2_ENCRYPTION_CAPABILITIES;
if (require_gcm_256) {
pneg_ctxt->DataLength = cpu_to_le16(4); /* Cipher Count + 1 cipher */
pneg_ctxt->CipherCount = cpu_to_le16(1);
pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES256_GCM;
} else if (enable_gcm_256) {
pneg_ctxt->DataLength = cpu_to_le16(8); /* Cipher Count + 3 ciphers */
pneg_ctxt->CipherCount = cpu_to_le16(3);
pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_GCM;
pneg_ctxt->Ciphers[1] = SMB2_ENCRYPTION_AES256_GCM;
pneg_ctxt->Ciphers[2] = SMB2_ENCRYPTION_AES128_CCM;
} else {
pneg_ctxt->DataLength = cpu_to_le16(6); /* Cipher Count + 2 ciphers */
pneg_ctxt->CipherCount = cpu_to_le16(2);
pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_GCM;
pneg_ctxt->Ciphers[1] = SMB2_ENCRYPTION_AES128_CCM;
}
}
static unsigned int
build_netname_ctxt(struct smb2_netname_neg_context *pneg_ctxt, char *hostname)
{
struct nls_table *cp = load_nls_default();
pneg_ctxt->ContextType = SMB2_NETNAME_NEGOTIATE_CONTEXT_ID;
/* copy up to max of first 100 bytes of server name to NetName field */
pneg_ctxt->DataLength = cpu_to_le16(2 * cifs_strtoUTF16(pneg_ctxt->NetName, hostname, 100, cp));
/* context size is DataLength + minimal smb2_neg_context */
return DIV_ROUND_UP(le16_to_cpu(pneg_ctxt->DataLength) +
sizeof(struct smb2_neg_context), 8) * 8;
}
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);
/* SMB2_CREATE_TAG_POSIX is "0x93AD25509CB411E7B42383DE968BCD7C" */
pneg_ctxt->Name[0] = 0x93;
pneg_ctxt->Name[1] = 0xAD;
pneg_ctxt->Name[2] = 0x25;
pneg_ctxt->Name[3] = 0x50;
pneg_ctxt->Name[4] = 0x9C;
pneg_ctxt->Name[5] = 0xB4;
pneg_ctxt->Name[6] = 0x11;
pneg_ctxt->Name[7] = 0xE7;
pneg_ctxt->Name[8] = 0xB4;
pneg_ctxt->Name[9] = 0x23;
pneg_ctxt->Name[10] = 0x83;
pneg_ctxt->Name[11] = 0xDE;
pneg_ctxt->Name[12] = 0x96;
pneg_ctxt->Name[13] = 0x8B;
pneg_ctxt->Name[14] = 0xCD;
pneg_ctxt->Name[15] = 0x7C;
}
static void
assemble_neg_contexts(struct smb2_negotiate_req *req,
struct TCP_Server_Info *server, unsigned int *total_len)
{
char *pneg_ctxt;
char *hostname = NULL;
unsigned int ctxt_len, neg_context_count;
if (*total_len > 200) {
/* In case length corrupted don't want to overrun smb buffer */
cifs_server_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;
/*
* secondary channels don't have the hostname field populated
* use the hostname field in the primary channel instead
*/
hostname = CIFS_SERVER_IS_CHAN(server) ?
server->primary_server->hostname : server->hostname;
if (hostname && (hostname[0] != 0)) {
ctxt_len = build_netname_ctxt((struct smb2_netname_neg_context *)pneg_ctxt,
hostname);
*total_len += ctxt_len;
pneg_ctxt += ctxt_len;
neg_context_count = 3;
} else
neg_context_count = 2;
build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
*total_len += sizeof(struct smb2_posix_neg_context);
pneg_ctxt += sizeof(struct smb2_posix_neg_context);
neg_context_count++;
if (server->compress_algorithm) {
build_compression_ctxt((struct smb2_compression_capabilities_context *)
pneg_ctxt);
ctxt_len = DIV_ROUND_UP(
sizeof(struct smb2_compression_capabilities_context),
8) * 8;
*total_len += ctxt_len;
pneg_ctxt += ctxt_len;
neg_context_count++;
}
if (enable_negotiate_signing) {
ctxt_len = build_signing_ctxt((struct smb2_signing_capabilities *)
pneg_ctxt);
*total_len += ctxt_len;
pneg_ctxt += ctxt_len;
neg_context_count++;
}
/* check for and add transport_capabilities and signing capabilities */
req->NegotiateContextCount = cpu_to_le16(neg_context_count);
}
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) {
pr_warn_once("server sent bad preauth context\n");
return;
} else if (len < MIN_PREAUTH_CTXT_DATA_LEN + le16_to_cpu(ctxt->SaltLength)) {
pr_warn_once("server sent invalid SaltLength\n");
return;
}
if (le16_to_cpu(ctxt->HashAlgorithmCount) != 1)
pr_warn_once("Invalid SMB3 hash algorithm count\n");
if (ctxt->HashAlgorithms != SMB2_PREAUTH_INTEGRITY_SHA512)
pr_warn_once("unknown SMB3 hash algorithm\n");
}
static void decode_compress_ctx(struct TCP_Server_Info *server,
struct smb2_compression_capabilities_context *ctxt)
{
unsigned int len = le16_to_cpu(ctxt->DataLength);
/* sizeof compress context is a one element compression capbility struct */
if (len < 10) {
pr_warn_once("server sent bad compression cntxt\n");
return;
}
if (le16_to_cpu(ctxt->CompressionAlgorithmCount) != 1) {
pr_warn_once("Invalid SMB3 compress algorithm count\n");
return;
}
if (le16_to_cpu(ctxt->CompressionAlgorithms[0]) > 3) {
pr_warn_once("unknown compression algorithm\n");
return;
}
server->compress_algorithm = ctxt->CompressionAlgorithms[0];
}
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) {
pr_warn_once("server sent bad crypto ctxt len\n");
return -EINVAL;
}
if (le16_to_cpu(ctxt->CipherCount) != 1) {
pr_warn_once("Invalid SMB3.11 cipher count\n");
return -EINVAL;
}
cifs_dbg(FYI, "SMB311 cipher type:%d\n", le16_to_cpu(ctxt->Ciphers[0]));
if (require_gcm_256) {
if (ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES256_GCM) {
cifs_dbg(VFS, "Server does not support requested encryption type (AES256 GCM)\n");
return -EOPNOTSUPP;
}
} else if (ctxt->Ciphers[0] == 0) {
/*
* e.g. if server only supported AES256_CCM (very unlikely)
* or server supported no encryption types or had all disabled.
* Since GLOBAL_CAP_ENCRYPTION will be not set, in the case
* in which mount requested encryption ("seal") checks later
* on during tree connection will return proper rc, but if
* seal not requested by client, since server is allowed to
* return 0 to indicate no supported cipher, we can't fail here
*/
server->cipher_type = 0;
server->capabilities &= ~SMB2_GLOBAL_CAP_ENCRYPTION;
pr_warn_once("Server does not support requested encryption types\n");
return 0;
} else if ((ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_CCM) &&
(ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_GCM) &&
(ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES256_GCM)) {
/* server returned a cipher we didn't ask for */
pr_warn_once("Invalid SMB3.11 cipher returned\n");
return -EINVAL;
}
server->cipher_type = ctxt->Ciphers[0];
server->capabilities |= SMB2_GLOBAL_CAP_ENCRYPTION;
return 0;
}
static void decode_signing_ctx(struct TCP_Server_Info *server,
struct smb2_signing_capabilities *pctxt)
{
unsigned int len = le16_to_cpu(pctxt->DataLength);
if ((len < 4) || (len > 16)) {
pr_warn_once("server sent bad signing negcontext\n");
return;
}
if (le16_to_cpu(pctxt->SigningAlgorithmCount) != 1) {
pr_warn_once("Invalid signing algorithm count\n");
return;
}
if (le16_to_cpu(pctxt->SigningAlgorithms[0]) > 2) {
pr_warn_once("unknown signing algorithm\n");
return;
}
server->signing_negotiated = true;
server->signing_algorithm = le16_to_cpu(pctxt->SigningAlgorithms[0]);
cifs_dbg(FYI, "signing algorithm %d chosen\n",
server->signing_algorithm);
}
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_server_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_COMPRESSION_CAPABILITIES)
decode_compress_ctx(server,
(struct smb2_compression_capabilities_context *)pctx);
else if (pctx->ContextType == SMB2_POSIX_EXTENSIONS_AVAILABLE)
server->posix_ext_supported = true;
else if (pctx->ContextType == SMB2_SIGNING_CAPABILITIES)
decode_signing_ctx(server,
(struct smb2_signing_capabilities *)pctx);
else
cifs_server_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\n", 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 (mode == ACL_NO_MODE)
cifs_dbg(FYI, "Invalid mode\n");
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 TCP_Server_Info *server)
{
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;
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, server,
(void **) &req, &total_len);
if (rc)
return rc;
req->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(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->Dialects[2] = cpu_to_le16(SMB311_PROT_ID);
req->DialectCount = cpu_to_le16(3);
total_len += 6;
} else if (strcmp(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(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(server->vals->req_capabilities);
if (ses->chan_max > 1)
req->Capabilities |= cpu_to_le32(SMB2_GLOBAL_CAP_MULTI_CHANNEL);
/* ClientGUID must be zero for SMB2.02 dialect */
if (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 ((server->vals->protocol_id == SMB311_PROT_ID) ||
(strcmp(server->vals->version_string,
SMB3ANY_VERSION_STRING) == 0) ||
(strcmp(server->vals->version_string,
SMBDEFAULT_VERSION_STRING) == 0))
assemble_neg_contexts(req, server, &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, server,
&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_server_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;
rc = -EIO;
if (strcmp(server->vals->version_string,
SMB3ANY_VERSION_STRING) == 0) {
if (rsp->DialectRevision == cpu_to_le16(SMB20_PROT_ID)) {
cifs_server_dbg(VFS,
"SMB2 dialect returned but not requested\n");
goto neg_exit;
} else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID)) {
cifs_server_dbg(VFS,
"SMB2.1 dialect returned but not requested\n");
goto neg_exit;
} else if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID)) {
/* ops set to 3.0 by default for default so update */
server->ops = &smb311_operations;
server->vals = &smb311_values;
}
} else if (strcmp(server->vals->version_string,
SMBDEFAULT_VERSION_STRING) == 0) {
if (rsp->DialectRevision == cpu_to_le16(SMB20_PROT_ID)) {
cifs_server_dbg(VFS,
"SMB2 dialect returned but not requested\n");
goto neg_exit;
} else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID)) {
/* ops set to 3.0 by default for default so update */
server->ops = &smb21_operations;
server->vals = &smb21_values;
} else if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID)) {
server->ops = &smb311_operations;
server->vals = &smb311_values;
}
} else if (le16_to_cpu(rsp->DialectRevision) !=
server->vals->protocol_id) {
/* if requested single dialect ensure returned dialect matched */
cifs_server_dbg(VFS, "Invalid 0x%x dialect returned: not requested\n",