linux-hardened/fs/cifs/smb2ops.c

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/*
* SMB2 version specific operations
*
* Copyright (c) 2012, Jeff Layton <jlayton@redhat.com>
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License v2 as published
* by the Free Software Foundation.
*
* 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 "cifsglob.h"
#include "smb2pdu.h"
#include "smb2proto.h"
#include "cifsproto.h"
#include "cifs_debug.h"
static int
change_conf(struct TCP_Server_Info *server)
{
server->credits += server->echo_credits + server->oplock_credits;
server->oplock_credits = server->echo_credits = 0;
switch (server->credits) {
case 0:
return -1;
case 1:
server->echoes = false;
server->oplocks = false;
cERROR(1, "disabling echoes and oplocks");
break;
case 2:
server->echoes = true;
server->oplocks = false;
server->echo_credits = 1;
cFYI(1, "disabling oplocks");
break;
default:
server->echoes = true;
server->oplocks = true;
server->echo_credits = 1;
server->oplock_credits = 1;
}
server->credits -= server->echo_credits + server->oplock_credits;
return 0;
}
static void
smb2_add_credits(struct TCP_Server_Info *server, const unsigned int add,
const int optype)
{
int *val, rc = 0;
spin_lock(&server->req_lock);
val = server->ops->get_credits_field(server, optype);
*val += add;
server->in_flight--;
if (server->in_flight == 0 && (optype & CIFS_OP_MASK) != CIFS_NEG_OP)
rc = change_conf(server);
spin_unlock(&server->req_lock);
wake_up(&server->request_q);
if (rc)
cifs_reconnect(server);
}
static void
smb2_set_credits(struct TCP_Server_Info *server, const int val)
{
spin_lock(&server->req_lock);
server->credits = val;
spin_unlock(&server->req_lock);
}
static int *
smb2_get_credits_field(struct TCP_Server_Info *server, const int optype)
{
switch (optype) {
case CIFS_ECHO_OP:
return &server->echo_credits;
case CIFS_OBREAK_OP:
return &server->oplock_credits;
default:
return &server->credits;
}
}
static unsigned int
smb2_get_credits(struct mid_q_entry *mid)
{
return le16_to_cpu(((struct smb2_hdr *)mid->resp_buf)->CreditRequest);
}
static __u64
smb2_get_next_mid(struct TCP_Server_Info *server)
{
__u64 mid;
/* for SMB2 we need the current value */
spin_lock(&GlobalMid_Lock);
mid = server->CurrentMid++;
spin_unlock(&GlobalMid_Lock);
return mid;
}
static struct mid_q_entry *
smb2_find_mid(struct TCP_Server_Info *server, char *buf)
{
struct mid_q_entry *mid;
struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
spin_lock(&GlobalMid_Lock);
list_for_each_entry(mid, &server->pending_mid_q, qhead) {
if ((mid->mid == hdr->MessageId) &&
(mid->mid_state == MID_REQUEST_SUBMITTED) &&
(mid->command == hdr->Command)) {
spin_unlock(&GlobalMid_Lock);
return mid;
}
}
spin_unlock(&GlobalMid_Lock);
return NULL;
}
static void
smb2_dump_detail(void *buf)
{
#ifdef CONFIG_CIFS_DEBUG2
struct smb2_hdr *smb = (struct smb2_hdr *)buf;
cERROR(1, "Cmd: %d Err: 0x%x Flags: 0x%x Mid: %llu Pid: %d",
smb->Command, smb->Status, smb->Flags, smb->MessageId,
smb->ProcessId);
cERROR(1, "smb buf %p len %u", smb, smb2_calc_size(smb));
#endif
}
static bool
smb2_need_neg(struct TCP_Server_Info *server)
{
return server->max_read == 0;
}
static int
smb2_negotiate(const unsigned int xid, struct cifs_ses *ses)
{
int rc;
ses->server->CurrentMid = 0;
rc = SMB2_negotiate(xid, ses);
/* BB we probably don't need to retry with modern servers */
if (rc == -EAGAIN)
rc = -EHOSTDOWN;
return rc;
}
static int
smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon,
struct cifs_sb_info *cifs_sb, const char *full_path)
{
int rc;
__u64 persistent_fid, volatile_fid;
__le16 *utf16_path;
utf16_path = cifs_convert_path_to_utf16(full_path, cifs_sb);
if (!utf16_path)
return -ENOMEM;
rc = SMB2_open(xid, tcon, utf16_path, &persistent_fid, &volatile_fid,
FILE_READ_ATTRIBUTES, FILE_OPEN, 0, 0);
if (rc) {
kfree(utf16_path);
return rc;
}
rc = SMB2_close(xid, tcon, persistent_fid, volatile_fid);
kfree(utf16_path);
return rc;
}
struct smb_version_operations smb21_operations = {
.setup_request = smb2_setup_request,
.check_receive = smb2_check_receive,
.add_credits = smb2_add_credits,
.set_credits = smb2_set_credits,
.get_credits_field = smb2_get_credits_field,
.get_credits = smb2_get_credits,
.get_next_mid = smb2_get_next_mid,
.find_mid = smb2_find_mid,
.check_message = smb2_check_message,
.dump_detail = smb2_dump_detail,
.need_neg = smb2_need_neg,
.negotiate = smb2_negotiate,
.sess_setup = SMB2_sess_setup,
.logoff = SMB2_logoff,
.tree_connect = SMB2_tcon,
.tree_disconnect = SMB2_tdis,
.is_path_accessible = smb2_is_path_accessible,
};
struct smb_version_values smb21_values = {
.version_string = SMB21_VERSION_STRING,
.header_size = sizeof(struct smb2_hdr),
.max_header_size = MAX_SMB2_HDR_SIZE,
.lock_cmd = SMB2_LOCK,
};