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samba-mirror/source3/smbd/oplock.c
Ralph Boehme bcb4723aac Revert "smbd: explain that/why we use the raw tevent_context for lease_timeout_handler()"
This reverts commit 52f098d38d.

See the discussion in

https://lists.samba.org/archive/samba-technical/2018-December/131731.html

for the reasoning behind this revert.

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
2019-01-11 23:11:18 +01:00

1443 lines
39 KiB
C

/*
Unix SMB/CIFS implementation.
oplock processing
Copyright (C) Andrew Tridgell 1992-1998
Copyright (C) Jeremy Allison 1998 - 2001
Copyright (C) Volker Lendecke 2005
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#define DBGC_CLASS DBGC_LOCKING
#include "includes.h"
#include "lib/util/server_id.h"
#include "smbd/smbd.h"
#include "smbd/globals.h"
#include "messages.h"
#include "../librpc/gen_ndr/ndr_open_files.h"
/*
* helper function used by the kernel oplock backends to post the break message
*/
void break_kernel_oplock(struct messaging_context *msg_ctx, files_struct *fsp)
{
uint8_t msg[MSG_SMB_KERNEL_BREAK_SIZE];
/* Put the kernel break info into the message. */
push_file_id_24((char *)msg, &fsp->file_id);
SIVAL(msg,24,fsp->fh->gen_id);
/* Don't need to be root here as we're only ever
sending to ourselves. */
messaging_send_buf(msg_ctx, messaging_server_id(msg_ctx),
MSG_SMB_KERNEL_BREAK,
msg, MSG_SMB_KERNEL_BREAK_SIZE);
}
/****************************************************************************
Attempt to set an oplock on a file. Succeeds if kernel oplocks are
disabled (just sets flags).
****************************************************************************/
NTSTATUS set_file_oplock(files_struct *fsp)
{
struct smbd_server_connection *sconn = fsp->conn->sconn;
struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
bool use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) &&
(koplocks != NULL);
if (fsp->oplock_type == LEVEL_II_OPLOCK && use_kernel) {
DEBUG(10, ("Refusing level2 oplock, kernel oplocks "
"don't support them\n"));
return NT_STATUS_NOT_SUPPORTED;
}
if ((fsp->oplock_type != NO_OPLOCK) &&
use_kernel &&
!koplocks->ops->set_oplock(koplocks, fsp, fsp->oplock_type))
{
return map_nt_error_from_unix(errno);
}
fsp->sent_oplock_break = NO_BREAK_SENT;
if (fsp->oplock_type == LEVEL_II_OPLOCK) {
sconn->oplocks.level_II_open++;
} else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
sconn->oplocks.exclusive_open++;
}
DEBUG(5,("set_file_oplock: granted oplock on file %s, %s/%lu, "
"tv_sec = %x, tv_usec = %x\n",
fsp_str_dbg(fsp), file_id_string_tos(&fsp->file_id),
fsp->fh->gen_id, (int)fsp->open_time.tv_sec,
(int)fsp->open_time.tv_usec ));
return NT_STATUS_OK;
}
static void release_fsp_kernel_oplock(files_struct *fsp)
{
struct smbd_server_connection *sconn = fsp->conn->sconn;
struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
bool use_kernel;
if (koplocks == NULL) {
return;
}
use_kernel = lp_kernel_oplocks(SNUM(fsp->conn));
if (!use_kernel) {
return;
}
if (fsp->oplock_type == NO_OPLOCK) {
return;
}
if (fsp->oplock_type == LEASE_OPLOCK) {
/*
* For leases we don't touch kernel oplocks at all
*/
return;
}
koplocks->ops->release_oplock(koplocks, fsp, NO_OPLOCK);
}
/****************************************************************************
Attempt to release an oplock on a file. Decrements oplock count.
****************************************************************************/
static void release_file_oplock(files_struct *fsp)
{
struct smbd_server_connection *sconn = fsp->conn->sconn;
release_fsp_kernel_oplock(fsp);
if (fsp->oplock_type == LEVEL_II_OPLOCK) {
sconn->oplocks.level_II_open--;
} else if (EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
sconn->oplocks.exclusive_open--;
}
SMB_ASSERT(sconn->oplocks.exclusive_open>=0);
SMB_ASSERT(sconn->oplocks.level_II_open>=0);
fsp->oplock_type = NO_OPLOCK;
fsp->sent_oplock_break = NO_BREAK_SENT;
flush_write_cache(fsp, SAMBA_OPLOCK_RELEASE_FLUSH);
delete_write_cache(fsp);
TALLOC_FREE(fsp->oplock_timeout);
}
/****************************************************************************
Attempt to downgrade an oplock on a file. Doesn't decrement oplock count.
****************************************************************************/
static void downgrade_file_oplock(files_struct *fsp)
{
struct smbd_server_connection *sconn = fsp->conn->sconn;
struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
bool use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) &&
(koplocks != NULL);
if (!EXCLUSIVE_OPLOCK_TYPE(fsp->oplock_type)) {
DEBUG(0, ("trying to downgrade an already-downgraded oplock!\n"));
return;
}
if (use_kernel) {
koplocks->ops->release_oplock(koplocks, fsp, LEVEL_II_OPLOCK);
}
fsp->oplock_type = LEVEL_II_OPLOCK;
sconn->oplocks.exclusive_open--;
sconn->oplocks.level_II_open++;
fsp->sent_oplock_break = NO_BREAK_SENT;
flush_write_cache(fsp, SAMBA_OPLOCK_RELEASE_FLUSH);
delete_write_cache(fsp);
TALLOC_FREE(fsp->oplock_timeout);
}
uint32_t get_lease_type(const struct share_mode_data *d,
const struct share_mode_entry *e)
{
if (e->op_type == LEASE_OPLOCK) {
return d->leases[e->lease_idx].current_state;
}
return map_oplock_to_lease_type(e->op_type);
}
bool update_num_read_oplocks(files_struct *fsp, struct share_mode_lock *lck)
{
struct share_mode_data *d = lck->data;
struct byte_range_lock *br_lck;
uint32_t num_read_oplocks = 0;
uint32_t i;
if (fsp_lease_type_is_exclusive(fsp)) {
const struct share_mode_entry *e = NULL;
uint32_t e_lease_type = 0;
/*
* If we're fully exclusive, we don't need a brlock entry
*/
remove_stale_share_mode_entries(d);
e = find_share_mode_entry(lck, fsp);
if (e != NULL) {
e_lease_type = get_lease_type(d, e);
}
if (!lease_type_is_exclusive(e_lease_type)) {
char *timestr = NULL;
timestr = timeval_string(talloc_tos(),
&fsp->open_time,
true);
NDR_PRINT_DEBUG(share_mode_data, d);
DBG_ERR("file [%s] file_id [%s] gen_id [%lu] "
"open_time[%s] lease_type [0x%x] "
"oplock_type [0x%x]\n",
fsp_str_dbg(fsp),
file_id_string_tos(&fsp->file_id),
fsp->fh->gen_id, timestr,
e_lease_type, fsp->oplock_type);
smb_panic("Found non-exclusive lease");
}
return true;
}
for (i=0; i<d->num_share_modes; i++) {
struct share_mode_entry *e = &d->share_modes[i];
uint32_t e_lease_type = get_lease_type(d, e);
if (e_lease_type & SMB2_LEASE_READ) {
num_read_oplocks += 1;
}
}
br_lck = brl_get_locks_readonly(fsp);
if (br_lck == NULL) {
return false;
}
if (brl_num_read_oplocks(br_lck) == num_read_oplocks) {
return true;
}
br_lck = brl_get_locks(talloc_tos(), fsp);
if (br_lck == NULL) {
return false;
}
brl_set_num_read_oplocks(br_lck, num_read_oplocks);
TALLOC_FREE(br_lck);
return true;
}
/****************************************************************************
Remove a file oplock with lock already held. Copes with level II and exclusive.
****************************************************************************/
bool remove_oplock_under_lock(files_struct *fsp, struct share_mode_lock *lck)
{
bool ret;
ret = remove_share_oplock(lck, fsp);
if (!ret) {
DBG_ERR("failed to remove share oplock for "
"file %s, %s, %s\n",
fsp_str_dbg(fsp), fsp_fnum_dbg(fsp),
file_id_string_tos(&fsp->file_id));
}
release_file_oplock(fsp);
ret = update_num_read_oplocks(fsp, lck);
if (!ret) {
DBG_ERR("update_num_read_oplocks failed for "
"file %s, %s, %s\n",
fsp_str_dbg(fsp), fsp_fnum_dbg(fsp),
file_id_string_tos(&fsp->file_id));
}
return ret;
}
/****************************************************************************
Remove a file oplock. Copes with level II and exclusive.
Locks then unlocks the share mode lock. Client can decide to go directly
to none even if a "break-to-level II" was sent.
****************************************************************************/
bool remove_oplock(files_struct *fsp)
{
bool ret;
struct share_mode_lock *lck;
DBG_DEBUG("remove_oplock called for %s\n", fsp_str_dbg(fsp));
/* Remove the oplock flag from the sharemode. */
lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
if (lck == NULL) {
DBG_ERR("failed to lock share entry for "
"file %s\n", fsp_str_dbg(fsp));
return false;
}
ret = remove_oplock_under_lock(fsp, lck);
TALLOC_FREE(lck);
return ret;
}
/*
* Deal with a reply when a break-to-level II was sent.
*/
bool downgrade_oplock(files_struct *fsp)
{
bool ret;
struct share_mode_lock *lck;
DEBUG(10, ("downgrade_oplock called for %s\n",
fsp_str_dbg(fsp)));
lck = get_existing_share_mode_lock(talloc_tos(), fsp->file_id);
if (lck == NULL) {
DEBUG(0,("downgrade_oplock: failed to lock share entry for "
"file %s\n", fsp_str_dbg(fsp)));
return False;
}
ret = downgrade_share_oplock(lck, fsp);
if (!ret) {
DEBUG(0,("downgrade_oplock: failed to downgrade share oplock "
"for file %s, %s, file_id %s\n",
fsp_str_dbg(fsp), fsp_fnum_dbg(fsp),
file_id_string_tos(&fsp->file_id)));
}
downgrade_file_oplock(fsp);
ret = update_num_read_oplocks(fsp, lck);
if (!ret) {
DEBUG(0, ("%s: update_num_read_oplocks failed for "
"file %s, %s, %s\n",
__func__, fsp_str_dbg(fsp), fsp_fnum_dbg(fsp),
file_id_string_tos(&fsp->file_id)));
}
TALLOC_FREE(lck);
return ret;
}
static void lease_timeout_handler(struct tevent_context *ctx,
struct tevent_timer *te,
struct timeval now,
void *private_data)
{
struct fsp_lease *lease =
talloc_get_type_abort(private_data,
struct fsp_lease);
struct files_struct *fsp;
struct share_mode_lock *lck;
uint16_t old_epoch = lease->lease.lease_epoch;
fsp = file_find_one_fsp_from_lease_key(lease->sconn,
&lease->lease.lease_key);
if (fsp == NULL) {
/* race? */
TALLOC_FREE(lease->timeout);
return;
}
/*
* Paranoia check: There can only be one fsp_lease per lease
* key
*/
SMB_ASSERT(fsp->lease == lease);
lck = get_existing_share_mode_lock(
talloc_tos(), fsp->file_id);
if (lck == NULL) {
/* race? */
TALLOC_FREE(lease->timeout);
return;
}
fsp_lease_update(lck, fsp_client_guid(fsp), lease);
if (lease->lease.lease_epoch != old_epoch) {
/*
* If the epoch changed we need to wait for
* the next timeout to happen.
*/
DEBUG(10, ("lease break timeout race (epoch) for file %s - ignoring\n",
fsp_str_dbg(fsp)));
TALLOC_FREE(lck);
return;
}
if (!(lease->lease.lease_flags & SMB2_LEASE_FLAG_BREAK_IN_PROGRESS)) {
/*
* If the epoch changed we need to wait for
* the next timeout to happen.
*/
DEBUG(10, ("lease break timeout race (flags) for file %s - ignoring\n",
fsp_str_dbg(fsp)));
TALLOC_FREE(lck);
return;
}
DEBUG(1, ("lease break timed out for file %s -- replying anyway\n",
fsp_str_dbg(fsp)));
(void)downgrade_lease(lease->sconn->client->connections,
1,
&fsp->file_id,
&lease->lease.lease_key,
SMB2_LEASE_NONE);
TALLOC_FREE(lck);
}
bool fsp_lease_update(struct share_mode_lock *lck,
const struct GUID *client_guid,
struct fsp_lease *lease)
{
struct share_mode_data *d = lck->data;
int idx;
struct share_mode_lease *l = NULL;
idx = find_share_mode_lease(d, client_guid, &lease->lease.lease_key);
if (idx == -1) {
DEBUG(1, ("%s: Could not find lease entry\n", __func__));
TALLOC_FREE(lease->timeout);
lease->lease.lease_state = SMB2_LEASE_NONE;
lease->lease.lease_epoch += 1;
lease->lease.lease_flags = 0;
return false;
}
l = &d->leases[idx];
DEBUG(10,("%s: refresh lease state\n", __func__));
/* Ensure we're in sync with current lease state. */
if (lease->lease.lease_epoch != l->epoch) {
DEBUG(10,("%s: cancel outdated timeout\n", __func__));
TALLOC_FREE(lease->timeout);
}
lease->lease.lease_epoch = l->epoch;
lease->lease.lease_state = l->current_state;
if (l->breaking) {
lease->lease.lease_flags |= SMB2_LEASE_FLAG_BREAK_IN_PROGRESS;
if (lease->timeout == NULL) {
struct timeval t = timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0);
DEBUG(10,("%s: setup timeout handler\n", __func__));
lease->timeout = tevent_add_timer(lease->sconn->ev_ctx,
lease, t,
lease_timeout_handler,
lease);
if (lease->timeout == NULL) {
DEBUG(0, ("%s: Could not add lease timeout handler\n",
__func__));
}
}
} else {
lease->lease.lease_flags &= ~SMB2_LEASE_FLAG_BREAK_IN_PROGRESS;
TALLOC_FREE(lease->timeout);
}
return true;
}
struct downgrade_lease_additional_state {
struct tevent_immediate *im;
struct smbXsrv_connection *xconn;
uint32_t break_flags;
struct smb2_lease_key lease_key;
uint32_t break_from;
uint32_t break_to;
uint16_t new_epoch;
};
static void downgrade_lease_additional_trigger(struct tevent_context *ev,
struct tevent_immediate *im,
void *private_data)
{
struct downgrade_lease_additional_state *state =
talloc_get_type_abort(private_data,
struct downgrade_lease_additional_state);
struct smbXsrv_connection *xconn = state->xconn;
NTSTATUS status;
status = smbd_smb2_send_lease_break(xconn,
state->new_epoch,
state->break_flags,
&state->lease_key,
state->break_from,
state->break_to);
TALLOC_FREE(state);
if (!NT_STATUS_IS_OK(status)) {
smbd_server_connection_terminate(xconn,
nt_errstr(status));
return;
}
}
struct downgrade_lease_fsps_state {
struct file_id id;
struct share_mode_lock *lck;
const struct smb2_lease_key *key;
};
static struct files_struct *downgrade_lease_fsps(struct files_struct *fsp,
void *private_data)
{
struct downgrade_lease_fsps_state *state =
(struct downgrade_lease_fsps_state *)private_data;
if (fsp->oplock_type != LEASE_OPLOCK) {
return NULL;
}
if (!smb2_lease_key_equal(&fsp->lease->lease.lease_key, state->key)) {
return NULL;
}
if (!file_id_equal(&fsp->file_id, &state->id)) {
return NULL;
}
fsp_lease_update(state->lck, fsp_client_guid(fsp), fsp->lease);
return NULL;
}
NTSTATUS downgrade_lease(struct smbXsrv_connection *xconn,
uint32_t num_file_ids,
const struct file_id *ids,
const struct smb2_lease_key *key,
uint32_t lease_state)
{
struct smbd_server_connection *sconn = xconn->client->sconn;
struct share_mode_lock *lck;
struct share_mode_data *d = NULL;
struct share_mode_lease *l = NULL;
const struct file_id id = ids[0];
int idx;
uint32_t i;
NTSTATUS status;
DEBUG(10, ("%s: Downgrading %s to %x\n", __func__,
file_id_string_tos(&id), (unsigned)lease_state));
lck = get_existing_share_mode_lock(talloc_tos(), id);
if (lck == NULL) {
return NT_STATUS_OBJECT_NAME_NOT_FOUND;
}
d = lck->data;
idx = find_share_mode_lease(
d, &sconn->client->connections->smb2.client.guid, key);
if (idx == -1) {
DEBUG(10, ("lease not found\n"));
return NT_STATUS_INVALID_PARAMETER;
}
l = &d->leases[idx];
if (!l->breaking) {
DBG_WARNING("Attempt to break from %"PRIu32" to %"PRIu32" - "
"but we're not in breaking state\n",
l->current_state, lease_state);
TALLOC_FREE(lck);
return NT_STATUS_UNSUCCESSFUL;
}
/*
* Can't upgrade anything: l->breaking_to_requested (and l->current_state)
* must be a strict bitwise superset of new_lease_state
*/
if ((lease_state & l->breaking_to_requested) != lease_state) {
DBG_WARNING("Attempt to upgrade from %"PRIu32" to %"PRIu32" "
"- expected %"PRIu32"\n",
l->current_state, lease_state,
l->breaking_to_requested);
TALLOC_FREE(lck);
return NT_STATUS_REQUEST_NOT_ACCEPTED;
}
if (l->current_state != lease_state) {
l->current_state = lease_state;
d->modified = true;
}
status = NT_STATUS_OK;
d->modified = true;
if ((lease_state & ~l->breaking_to_required) != 0) {
struct downgrade_lease_additional_state *state;
DBG_INFO("lease state %"PRIu32" not fully broken from "
"%"PRIu32" to %"PRIu32"\n",
lease_state,
l->current_state,
l->breaking_to_required);
l->breaking_to_requested = l->breaking_to_required;
if (l->current_state & (SMB2_LEASE_WRITE|SMB2_LEASE_HANDLE)) {
/*
* Here we break in steps, as windows does
* see the breaking3 and v2_breaking3 tests.
*/
l->breaking_to_requested |= SMB2_LEASE_READ;
}
state = talloc_zero(xconn,
struct downgrade_lease_additional_state);
if (state == NULL) {
TALLOC_FREE(lck);
return NT_STATUS_NO_MEMORY;
}
state->im = tevent_create_immediate(state);
if (state->im == NULL) {
TALLOC_FREE(state);
TALLOC_FREE(lck);
return NT_STATUS_NO_MEMORY;
}
state->xconn = xconn;
state->lease_key = l->lease_key;
state->break_from = l->current_state;
state->break_to = l->breaking_to_requested;
if (l->lease_version > 1) {
state->new_epoch = l->epoch;
}
if (l->current_state & (SMB2_LEASE_WRITE|SMB2_LEASE_HANDLE)) {
state->break_flags =
SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED;
} else {
/*
* This is an async break without
* SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED
*
* we need to store NONE state in the
* database.
*/
l->current_state = 0;
l->breaking_to_requested = 0;
l->breaking_to_required = 0;
l->breaking = false;
lck->data->modified = true;
}
tevent_schedule_immediate(state->im,
xconn->client->raw_ev_ctx,
downgrade_lease_additional_trigger,
state);
status = NT_STATUS_OPLOCK_BREAK_IN_PROGRESS;
} else {
DBG_DEBUG("breaking from %"PRIu32" to %"PRIu32" - "
"expected %"PRIu32"\n",
l->current_state,
lease_state,
l->breaking_to_requested);
l->breaking_to_requested = 0;
l->breaking_to_required = 0;
l->breaking = false;
d->modified = true;
}
DEBUG(10, ("%s: Downgrading %s to %x => %s\n", __func__,
file_id_string_tos(&id), (unsigned)lease_state, nt_errstr(status)));
{
struct downgrade_lease_fsps_state state = {
.id = id, .lck = lck, .key = key,
};
files_forall(sconn, downgrade_lease_fsps, &state);
}
TALLOC_FREE(lck);
DEBUG(10, ("%s: Downgrading %s to %x => %s\n", __func__,
file_id_string_tos(&id), (unsigned)lease_state, nt_errstr(status)));
/*
* Dynamic share case. Ensure other opens are copies.
* This will only be breaking to NONE.
*/
for (i = 1; i < num_file_ids; i++) {
lck = get_existing_share_mode_lock(talloc_tos(), ids[i]);
if (lck == NULL) {
return NT_STATUS_OBJECT_NAME_NOT_FOUND;
}
{
struct downgrade_lease_fsps_state state = {
.id = ids[i], .lck = lck, .key = key,
};
files_forall(sconn, downgrade_lease_fsps, &state);
}
DEBUG(10, ("%s: Downgrading %s to %x => %s\n", __func__,
file_id_string_tos(&ids[i]), (unsigned)lease_state, nt_errstr(status)));
TALLOC_FREE(lck);
}
return status;
}
/****************************************************************************
Set up an oplock break message.
****************************************************************************/
#define SMB1_BREAK_MESSAGE_LENGTH (smb_size + 8*2)
static void new_break_message_smb1(files_struct *fsp, int cmd,
char result[SMB1_BREAK_MESSAGE_LENGTH])
{
memset(result,'\0',smb_size);
srv_set_message(result,8,0,true);
SCVAL(result,smb_com,SMBlockingX);
SSVAL(result,smb_tid,fsp->conn->cnum);
SSVAL(result,smb_pid,0xFFFF);
SSVAL(result,smb_uid,0);
SSVAL(result,smb_mid,0xFFFF);
SCVAL(result,smb_vwv0,0xFF);
SSVAL(result,smb_vwv2,fsp->fnum);
SCVAL(result,smb_vwv3,LOCKING_ANDX_OPLOCK_RELEASE);
SCVAL(result,smb_vwv3+1,cmd);
}
/****************************************************************************
Function to do the waiting before sending a local break.
****************************************************************************/
static void wait_before_sending_break(void)
{
long wait_time = (long)lp_oplock_break_wait_time();
if (wait_time) {
smb_msleep(wait_time);
}
}
/****************************************************************************
Ensure that we have a valid oplock.
****************************************************************************/
static files_struct *initial_break_processing(
struct smbd_server_connection *sconn, struct file_id id,
unsigned long file_id)
{
files_struct *fsp = NULL;
DEBUG(3, ("initial_break_processing: called for %s/%u\n"
"Current oplocks_open (exclusive = %d, levelII = %d)\n",
file_id_string_tos(&id), (int)file_id,
sconn->oplocks.exclusive_open,
sconn->oplocks.level_II_open));
/*
* We need to search the file open table for the
* entry containing this dev and inode, and ensure
* we have an oplock on it.
*/
fsp = file_find_dif(sconn, id, file_id);
if(fsp == NULL) {
/* The file could have been closed in the meantime - return success. */
DEBUG(3, ("initial_break_processing: cannot find open file "
"with file_id %s gen_id = %lu, allowing break to "
"succeed.\n", file_id_string_tos(&id), file_id));
return NULL;
}
/* Ensure we have an oplock on the file */
/*
* There is a potential race condition in that an oplock could
* have been broken due to another udp request, and yet there are
* still oplock break messages being sent in the udp message
* queue for this file. So return true if we don't have an oplock,
* as we may have just freed it.
*/
if(fsp->oplock_type == NO_OPLOCK) {
DEBUG(3, ("initial_break_processing: file %s (file_id = %s "
"gen_id = %lu) has no oplock. Allowing break to "
"succeed regardless.\n", fsp_str_dbg(fsp),
file_id_string_tos(&id), fsp->fh->gen_id));
return NULL;
}
return fsp;
}
static void oplock_timeout_handler(struct tevent_context *ctx,
struct tevent_timer *te,
struct timeval now,
void *private_data)
{
files_struct *fsp = (files_struct *)private_data;
SMB_ASSERT(fsp->sent_oplock_break != NO_BREAK_SENT);
/* Remove the timed event handler. */
TALLOC_FREE(fsp->oplock_timeout);
DEBUG(0, ("Oplock break failed for file %s -- replying anyway\n",
fsp_str_dbg(fsp)));
remove_oplock(fsp);
}
/*******************************************************************
Add a timeout handler waiting for the client reply.
*******************************************************************/
static void add_oplock_timeout_handler(files_struct *fsp)
{
if (fsp->oplock_timeout != NULL) {
DEBUG(0, ("Logic problem -- have an oplock event hanging "
"around\n"));
}
fsp->oplock_timeout =
tevent_add_timer(fsp->conn->sconn->ev_ctx, fsp,
timeval_current_ofs(OPLOCK_BREAK_TIMEOUT, 0),
oplock_timeout_handler, fsp);
if (fsp->oplock_timeout == NULL) {
DEBUG(0, ("Could not add oplock timeout handler\n"));
}
}
static void send_break_message_smb1(files_struct *fsp, int level)
{
struct smbXsrv_connection *xconn = NULL;
char break_msg[SMB1_BREAK_MESSAGE_LENGTH];
/*
* For SMB1 we only have one connection
*/
xconn = fsp->conn->sconn->client->connections;
new_break_message_smb1(fsp, level, break_msg);
show_msg(break_msg);
if (!srv_send_smb(xconn,
break_msg, false, 0,
IS_CONN_ENCRYPTED(fsp->conn),
NULL)) {
exit_server_cleanly("send_break_message_smb1: "
"srv_send_smb failed.");
}
}
/*******************************************************************
This handles the generic oplock break message from another smbd.
*******************************************************************/
static void process_oplock_break_message(struct messaging_context *msg_ctx,
void *private_data,
uint32_t msg_type,
struct server_id src,
DATA_BLOB *data)
{
struct file_id id;
struct share_mode_entry msg;
files_struct *fsp;
bool use_kernel;
struct smbd_server_connection *sconn =
talloc_get_type_abort(private_data,
struct smbd_server_connection);
struct server_id self = messaging_server_id(sconn->msg_ctx);
struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
uint16_t break_from;
uint16_t break_to;
bool break_needed = true;
struct server_id_buf tmp;
if (data->data == NULL) {
DEBUG(0, ("Got NULL buffer\n"));
return;
}
if (data->length != MSG_SMB_SHARE_MODE_ENTRY_SIZE) {
DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
return;
}
/* De-linearize incoming message. */
message_to_share_mode_entry(&id, &msg, (char *)data->data);
break_to = msg.op_type;
DEBUG(10, ("Got oplock break to %u message from pid %s: %s/%llu\n",
(unsigned)break_to, server_id_str_buf(src, &tmp),
file_id_string_tos(&id),
(unsigned long long)msg.share_file_id));
fsp = initial_break_processing(sconn, id, msg.share_file_id);
if (fsp == NULL) {
/* We hit a race here. Break messages are sent, and before we
* get to process this message, we have closed the file. */
DEBUG(3, ("Did not find fsp\n"));
return;
}
break_from = fsp_lease_type(fsp);
if (fsp->oplock_type != LEASE_OPLOCK) {
if (fsp->sent_oplock_break != NO_BREAK_SENT) {
/*
* Nothing to do anymore
*/
DEBUG(10, ("fsp->sent_oplock_break = %d\n",
fsp->sent_oplock_break));
return;
}
}
if (!(global_client_caps & CAP_LEVEL_II_OPLOCKS)) {
DEBUG(10, ("client_caps without level2 oplocks\n"));
break_to &= ~SMB2_LEASE_READ;
}
use_kernel = lp_kernel_oplocks(SNUM(fsp->conn)) &&
(koplocks != NULL);
if (use_kernel) {
DEBUG(10, ("Kernel oplocks don't allow level2\n"));
break_to &= ~SMB2_LEASE_READ;
}
if (!lp_level2_oplocks(SNUM(fsp->conn))) {
DEBUG(10, ("no level2 oplocks by config\n"));
break_to &= ~SMB2_LEASE_READ;
}
if (fsp->oplock_type == LEASE_OPLOCK) {
struct share_mode_lock *lck;
int idx;
lck = get_existing_share_mode_lock(
talloc_tos(), fsp->file_id);
if (lck == NULL) {
/*
* We hit a race here. Break messages are sent, and
* before we get to process this message, we have closed
* the file.
*/
DEBUG(3, ("Did not find share_mode\n"));
return;
}
idx = find_share_mode_lease(
lck->data,
fsp_client_guid(fsp),
&fsp->lease->lease.lease_key);
if (idx != -1) {
struct share_mode_lease *l;
l = &lck->data->leases[idx];
break_from = l->current_state;
break_to &= l->current_state;
if (l->breaking) {
break_to &= l->breaking_to_required;
if (l->breaking_to_required != break_to) {
/*
* Note we don't increment the epoch
* here, which might be a bug in
* Windows too...
*/
l->breaking_to_required = break_to;
lck->data->modified = true;
}
break_needed = false;
} else if (l->current_state == break_to) {
break_needed = false;
} else if (l->current_state == SMB2_LEASE_READ) {
l->current_state = SMB2_LEASE_NONE;
/* Need to increment the epoch */
l->epoch += 1;
lck->data->modified = true;
} else {
l->breaking = true;
l->breaking_to_required = break_to;
l->breaking_to_requested = break_to;
/* Need to increment the epoch */
l->epoch += 1;
lck->data->modified = true;
}
/* Ensure we're in sync with current lease state. */
fsp_lease_update(lck, fsp_client_guid(fsp), fsp->lease);
}
TALLOC_FREE(lck);
}
if (!break_needed) {
DEBUG(10,("%s: skip break\n", __func__));
return;
}
if ((break_from == SMB2_LEASE_NONE) && !break_needed) {
DEBUG(3, ("Already downgraded oplock to none on %s: %s\n",
file_id_string_tos(&fsp->file_id),
fsp_str_dbg(fsp)));
return;
}
DEBUG(10, ("break_from=%u, break_to=%u\n",
(unsigned)break_from, (unsigned)break_to));
if ((break_from == break_to) && !break_needed) {
DEBUG(3, ("Already downgraded oplock to %u on %s: %s\n",
(unsigned)break_to,
file_id_string_tos(&fsp->file_id),
fsp_str_dbg(fsp)));
return;
}
/* Need to wait before sending a break
message if we sent ourselves this message. */
if (serverid_equal(&self, &src)) {
wait_before_sending_break();
}
if (sconn->using_smb2) {
send_break_message_smb2(fsp, break_from, break_to);
} else {
send_break_message_smb1(fsp, (break_to & SMB2_LEASE_READ) ?
OPLOCKLEVEL_II : OPLOCKLEVEL_NONE);
}
if ((break_from == SMB2_LEASE_READ) &&
(break_to == SMB2_LEASE_NONE)) {
/*
* This is an async break without a reply and thus no timeout
*
* leases are handled above.
*/
if (fsp->oplock_type != LEASE_OPLOCK) {
remove_oplock(fsp);
}
return;
}
if (fsp->oplock_type == LEASE_OPLOCK) {
return;
}
fsp->sent_oplock_break = (break_to & SMB2_LEASE_READ) ?
LEVEL_II_BREAK_SENT:BREAK_TO_NONE_SENT;
add_oplock_timeout_handler(fsp);
}
/*******************************************************************
This handles the kernel oplock break message.
*******************************************************************/
static void process_kernel_oplock_break(struct messaging_context *msg_ctx,
void *private_data,
uint32_t msg_type,
struct server_id src,
DATA_BLOB *data)
{
struct file_id id;
unsigned long file_id;
files_struct *fsp;
struct smbd_server_connection *sconn =
talloc_get_type_abort(private_data,
struct smbd_server_connection);
struct server_id_buf tmp;
if (data->data == NULL) {
DEBUG(0, ("Got NULL buffer\n"));
return;
}
if (data->length != MSG_SMB_KERNEL_BREAK_SIZE) {
DEBUG(0, ("Got invalid msg len %d\n", (int)data->length));
return;
}
/* Pull the data from the message. */
pull_file_id_24((char *)data->data, &id);
file_id = (unsigned long)IVAL(data->data, 24);
DEBUG(10, ("Got kernel oplock break message from pid %s: %s/%u\n",
server_id_str_buf(src, &tmp), file_id_string_tos(&id),
(unsigned int)file_id));
fsp = initial_break_processing(sconn, id, file_id);
if (fsp == NULL) {
DEBUG(3, ("Got a kernel oplock break message for a file "
"I don't know about\n"));
return;
}
if (fsp->sent_oplock_break != NO_BREAK_SENT) {
/* This is ok, kernel oplocks come in completely async */
DEBUG(3, ("Got a kernel oplock request while waiting for a "
"break reply\n"));
return;
}
if (sconn->using_smb2) {
send_break_message_smb2(fsp, 0, OPLOCKLEVEL_NONE);
} else {
send_break_message_smb1(fsp, OPLOCKLEVEL_NONE);
}
fsp->sent_oplock_break = BREAK_TO_NONE_SENT;
add_oplock_timeout_handler(fsp);
}
static bool file_has_read_oplocks(struct files_struct *fsp)
{
struct byte_range_lock *brl;
uint32_t num_read_oplocks = 0;
brl = brl_get_locks_readonly(fsp);
if (brl == NULL) {
return false;
}
num_read_oplocks = brl_num_read_oplocks(brl);
DBG_DEBUG("num_read_oplocks = %"PRIu32"\n", num_read_oplocks);
return (num_read_oplocks != 0);
}
struct break_to_none_state {
struct smbd_server_connection *sconn;
struct file_id id;
struct smb2_lease_key lease_key;
struct GUID client_guid;
};
static void do_break_to_none(struct tevent_context *ctx,
struct tevent_immediate *im,
void *private_data);
/****************************************************************************
This function is called on any file modification or lock request. If a file
is level 2 oplocked then it must tell all other level 2 holders to break to
none.
****************************************************************************/
static void contend_level2_oplocks_begin_default(files_struct *fsp,
enum level2_contention_type type)
{
struct smbd_server_connection *sconn = fsp->conn->sconn;
struct tevent_immediate *im;
struct break_to_none_state *state;
bool has_read_oplocks;
/*
* If this file is level II oplocked then we need
* to grab the shared memory lock and inform all
* other files with a level II lock that they need
* to flush their read caches. We keep the lock over
* the shared memory area whilst doing this.
*/
if (fsp_lease_type_is_exclusive(fsp)) {
/*
* There can't be any level2 oplocks, we're alone.
*/
return;
}
has_read_oplocks = file_has_read_oplocks(fsp);
if (!has_read_oplocks) {
DEBUG(10, ("No read oplocks around\n"));
return;
}
/*
* When we get here we might have a brlock entry locked. Also
* locking the share mode entry would violate the locking
* order. Breaking level2 oplocks to none is asynchronous
* anyway, so we postpone this into an immediate event.
*/
state = talloc_zero(sconn, struct break_to_none_state);
if (state == NULL) {
DEBUG(1, ("talloc failed\n"));
return;
}
state->sconn = sconn;
state->id = fsp->file_id;
if (fsp->oplock_type == LEASE_OPLOCK) {
state->client_guid = *fsp_client_guid(fsp);
state->lease_key = fsp->lease->lease.lease_key;
DEBUG(10, ("Breaking through lease key %"PRIu64"/%"PRIu64"\n",
state->lease_key.data[0],
state->lease_key.data[1]));
}
im = tevent_create_immediate(state);
if (im == NULL) {
DEBUG(1, ("tevent_create_immediate failed\n"));
TALLOC_FREE(state);
return;
}
tevent_schedule_immediate(im, sconn->ev_ctx, do_break_to_none, state);
}
static void send_break_to_none(struct messaging_context *msg_ctx,
const struct file_id *id,
const struct share_mode_entry *e)
{
char msg[MSG_SMB_SHARE_MODE_ENTRY_SIZE];
share_mode_entry_to_message(msg, id, e);
/* Overload entry->op_type */
SSVAL(msg, OP_BREAK_MSG_OP_TYPE_OFFSET, NO_OPLOCK);
messaging_send_buf(msg_ctx, e->pid, MSG_SMB_BREAK_REQUEST,
(uint8_t *)msg, sizeof(msg));
}
static void do_break_to_none(struct tevent_context *ctx,
struct tevent_immediate *im,
void *private_data)
{
struct break_to_none_state *state = talloc_get_type_abort(
private_data, struct break_to_none_state);
uint32_t i;
struct share_mode_lock *lck;
struct share_mode_data *d;
lck = get_existing_share_mode_lock(talloc_tos(), state->id);
if (lck == NULL) {
DEBUG(1, ("%s: failed to lock share mode entry for file %s.\n",
__func__, file_id_string_tos(&state->id)));
goto done;
}
d = lck->data;
/*
* Walk leases and oplocks separately: We have to send one break per
* lease. If we have multiple share_mode_entry having a common lease,
* we would break the lease twice if we don't walk the leases list
* separately.
*/
for (i=0; i<d->num_leases; i++) {
struct share_mode_lease *l = &d->leases[i];
struct share_mode_entry *e = NULL;
uint32_t j;
if ((l->current_state & SMB2_LEASE_READ) == 0) {
continue;
}
if (smb2_lease_equal(&state->client_guid,
&state->lease_key,
&l->client_guid,
&l->lease_key)) {
DEBUG(10, ("Don't break our own lease\n"));
continue;
}
for (j=0; j<d->num_share_modes; j++) {
e = &d->share_modes[j];
if (!is_valid_share_mode_entry(e)) {
continue;
}
if (e->lease_idx == i) {
break;
}
}
if (j == d->num_share_modes) {
DEBUG(0, ("leases[%"PRIu32"] has no share mode\n",
i));
continue;
}
DEBUG(10, ("Breaking lease# %"PRIu32" with share_entry# "
"%"PRIu32"\n", i, j));
send_break_to_none(state->sconn->msg_ctx, &state->id, e);
}
for(i = 0; i < d->num_share_modes; i++) {
struct share_mode_entry *e = &d->share_modes[i];
if (!is_valid_share_mode_entry(e)) {
continue;
}
if (e->op_type == LEASE_OPLOCK) {
/*
* Took care of those in the loop above
*/
continue;
}
/*
* As there could have been multiple writes waiting at the
* lock_share_entry gate we may not be the first to
* enter. Hence the state of the op_types in the share mode
* entries may be partly NO_OPLOCK and partly LEVEL_II
* oplock. It will do no harm to re-send break messages to
* those smbd's that are still waiting their turn to remove
* their LEVEL_II state, and also no harm to ignore existing
* NO_OPLOCK states. JRA.
*/
DEBUG(10, ("%s: share_entry[%i]->op_type == %d\n", __func__,
i, e->op_type ));
if (e->op_type == NO_OPLOCK) {
continue;
}
/* Paranoia .... */
if (EXCLUSIVE_OPLOCK_TYPE(e->op_type)) {
DEBUG(0,("%s: PANIC. "
"share mode entry %d is an exclusive "
"oplock !\n", __func__, i ));
TALLOC_FREE(lck);
abort();
}
send_break_to_none(state->sconn->msg_ctx, &state->id, e);
}
/* We let the message receivers handle removing the oplock state
in the share mode lock db. */
TALLOC_FREE(lck);
done:
TALLOC_FREE(state);
return;
}
void smbd_contend_level2_oplocks_begin(files_struct *fsp,
enum level2_contention_type type)
{
contend_level2_oplocks_begin_default(fsp, type);
}
void smbd_contend_level2_oplocks_end(files_struct *fsp,
enum level2_contention_type type)
{
return;
}
/****************************************************************************
Linearize a share mode entry struct to an internal oplock break message.
****************************************************************************/
void share_mode_entry_to_message(char *msg, const struct file_id *id,
const struct share_mode_entry *e)
{
SIVAL(msg,OP_BREAK_MSG_PID_OFFSET,(uint32_t)e->pid.pid);
SBVAL(msg,OP_BREAK_MSG_MID_OFFSET,e->op_mid);
SSVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET,e->op_type);
SIVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET,e->access_mask);
SIVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET,e->share_access);
SIVAL(msg,OP_BREAK_MSG_PRIV_OFFSET,e->private_options);
SIVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET,(uint32_t)e->time.tv_sec);
SIVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET,(uint32_t)e->time.tv_usec);
/*
* "id" used to be part of share_mode_entry, thus the strange
* place to put this. Feel free to move somewhere else :-)
*/
push_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, id);
SIVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET,e->share_file_id);
SIVAL(msg,OP_BREAK_MSG_UID_OFFSET,e->uid);
SSVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET,e->flags);
SIVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET,e->name_hash);
SIVAL(msg,OP_BREAK_MSG_VNN_OFFSET,e->pid.vnn);
}
/****************************************************************************
De-linearize an internal oplock break message to a share mode entry struct.
****************************************************************************/
void message_to_share_mode_entry(struct file_id *id,
struct share_mode_entry *e,
const char *msg)
{
e->pid.pid = (pid_t)IVAL(msg,OP_BREAK_MSG_PID_OFFSET);
e->op_mid = BVAL(msg,OP_BREAK_MSG_MID_OFFSET);
e->op_type = SVAL(msg,OP_BREAK_MSG_OP_TYPE_OFFSET);
e->access_mask = IVAL(msg,OP_BREAK_MSG_ACCESS_MASK_OFFSET);
e->share_access = IVAL(msg,OP_BREAK_MSG_SHARE_ACCESS_OFFSET);
e->private_options = IVAL(msg,OP_BREAK_MSG_PRIV_OFFSET);
e->time.tv_sec = (time_t)IVAL(msg,OP_BREAK_MSG_TIME_SEC_OFFSET);
e->time.tv_usec = (int)IVAL(msg,OP_BREAK_MSG_TIME_USEC_OFFSET);
/*
* "id" used to be part of share_mode_entry, thus the strange
* place to put this. Feel free to move somewhere else :-)
*/
pull_file_id_24(msg+OP_BREAK_MSG_DEV_OFFSET, id);
e->share_file_id = (unsigned long)IVAL(msg,OP_BREAK_MSG_FILE_ID_OFFSET);
e->uid = (uint32_t)IVAL(msg,OP_BREAK_MSG_UID_OFFSET);
e->flags = (uint16_t)SVAL(msg,OP_BREAK_MSG_FLAGS_OFFSET);
e->name_hash = IVAL(msg,OP_BREAK_MSG_NAME_HASH_OFFSET);
e->pid.vnn = IVAL(msg,OP_BREAK_MSG_VNN_OFFSET);
}
/****************************************************************************
Setup oplocks for this process.
****************************************************************************/
bool init_oplocks(struct smbd_server_connection *sconn)
{
DEBUG(3,("init_oplocks: initializing messages.\n"));
messaging_register(sconn->msg_ctx, sconn, MSG_SMB_BREAK_REQUEST,
process_oplock_break_message);
messaging_register(sconn->msg_ctx, sconn, MSG_SMB_KERNEL_BREAK,
process_kernel_oplock_break);
return true;
}
void init_kernel_oplocks(struct smbd_server_connection *sconn)
{
struct kernel_oplocks *koplocks = sconn->oplocks.kernel_ops;
/* only initialize once */
if (koplocks == NULL) {
#ifdef HAVE_KERNEL_OPLOCKS_LINUX
koplocks = linux_init_kernel_oplocks(sconn);
#endif
sconn->oplocks.kernel_ops = koplocks;
}
}