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/*
Unix SMB/CIFS implementation.
change notify handling
Copyright (C) Andrew Tridgell 2000
Copyright (C) Jeremy Allison 1994-1998
Copyright (C) Volker Lendecke 2007
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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
static struct cnotify_fns *cnotify;
static struct notify_mid_map *notify_changes_by_mid;
/*
* For NTCancel, we need to find the notify_change_request indexed by
* mid. Separate list here.
*/
struct notify_mid_map {
struct notify_mid_map *prev, *next;
struct notify_change_request *req;
uint16 mid;
};
static BOOL notify_marshall_changes(int num_changes,
struct notify_change *changes,
prs_struct *ps)
{
int i;
UNISTR uni_name;
for (i=0; i<num_changes; i++) {
struct notify_change *c = &changes[i];
size_t namelen;
uint32 u32_tmp; /* Temp arg to prs_uint32 to avoid
* signed/unsigned issues */
namelen = convert_string_allocate(
NULL, CH_UNIX, CH_UTF16LE, c->name, strlen(c->name)+1,
&uni_name.buffer, True);
if ((namelen == -1) || (uni_name.buffer == NULL)) {
goto fail;
}
namelen -= 2; /* Dump NULL termination */
/*
* Offset to next entry, only if there is one
*/
u32_tmp = (i == num_changes-1) ? 0 : namelen + 12;
if (!prs_uint32("offset", ps, 1, &u32_tmp)) goto fail;
u32_tmp = c->action;
if (!prs_uint32("action", ps, 1, &u32_tmp)) goto fail;
u32_tmp = namelen;
if (!prs_uint32("namelen", ps, 1, &u32_tmp)) goto fail;
if (!prs_unistr("name", ps, 1, &uni_name)) goto fail;
/*
* Not NULL terminated, decrease by the 2 UCS2 \0 chars
*/
prs_set_offset(ps, prs_offset(ps)-2);
SAFE_FREE(uni_name.buffer);
}
return True;
fail:
SAFE_FREE(uni_name.buffer);
return False;
}
/****************************************************************************
Setup the common parts of the return packet and send it.
*****************************************************************************/
static void change_notify_reply_packet(const char *request_buf,
NTSTATUS error_code)
{
char outbuf[smb_size+38];
memset(outbuf, '\0', sizeof(outbuf));
construct_reply_common(request_buf, outbuf);
ERROR_NT(error_code);
/*
* Seems NT needs a transact command with an error code
* in it. This is a longer packet than a simple error.
*/
set_message(outbuf,18,0,False);
show_msg(outbuf);
if (!send_smb(smbd_server_fd(),outbuf))
exit_server_cleanly("change_notify_reply_packet: send_smb "
"failed.");
}
void change_notify_reply(const char *request_buf, uint32 max_param_count,
int num_changes, struct notify_change *changes)
{
char *outbuf = NULL;
prs_struct ps;
size_t buflen = smb_size+38+max_param_count;
if (num_changes == -1) {
change_notify_reply_packet(request_buf, NT_STATUS_OK);
return;
}
if (!prs_init(&ps, 0, NULL, False)
|| !notify_marshall_changes(num_changes, changes, &ps)) {
change_notify_reply_packet(request_buf, NT_STATUS_NO_MEMORY);
goto done;
}
if (prs_offset(&ps) > max_param_count) {
/*
* We exceed what the client is willing to accept. Send
* nothing.
*/
change_notify_reply_packet(request_buf, NT_STATUS_OK);
goto done;
}
if (!(outbuf = SMB_MALLOC_ARRAY(char, buflen))) {
change_notify_reply_packet(request_buf, NT_STATUS_NO_MEMORY);
goto done;
}
construct_reply_common(request_buf, outbuf);
if (send_nt_replies(outbuf, buflen, NT_STATUS_OK, prs_data_p(&ps),
prs_offset(&ps), NULL, 0) == -1) {
exit_server("change_notify_reply_packet: send_smb failed.");
}
done:
SAFE_FREE(outbuf);
prs_mem_free(&ps);
}
NTSTATUS change_notify_add_request(const char *inbuf, uint32 max_param_count,
uint32 filter, struct files_struct *fsp)
{
struct notify_change_request *request = NULL;
struct notify_mid_map *map = NULL;
if (!(request = SMB_MALLOC_P(struct notify_change_request))
|| !(map = SMB_MALLOC_P(struct notify_mid_map))) {
SAFE_FREE(request);
return NT_STATUS_NO_MEMORY;
}
request->mid_map = map;
map->req = request;
memcpy(request->request_buf, inbuf, sizeof(request->request_buf));
request->max_param_count = max_param_count;
request->filter = filter;
request->fsp = fsp;
request->backend_data = cnotify->notify_add(NULL, smbd_event_context(),
fsp, &request->filter);
DLIST_ADD_END(fsp->notify->requests, request,
struct notify_change_request *);
map->mid = SVAL(inbuf, smb_mid);
DLIST_ADD(notify_changes_by_mid, map);
/* Push the MID of this packet on the signing queue. */
srv_defer_sign_response(SVAL(inbuf,smb_mid));
return NT_STATUS_OK;
}
static void change_notify_remove_request(struct notify_change_request *remove_req)
{
files_struct *fsp;
struct notify_change_request *req;
/*
* Paranoia checks, the fsp referenced must must have the request in
* its list of pending requests
*/
fsp = remove_req->fsp;
SMB_ASSERT(fsp->notify != NULL);
for (req = fsp->notify->requests; req; req = req->next) {
if (req == remove_req) {
break;
}
}
if (req == NULL) {
smb_panic("notify_req not found in fsp's requests\n");
}
DLIST_REMOVE(fsp->notify->requests, req);
DLIST_REMOVE(notify_changes_by_mid, req->mid_map);
SAFE_FREE(req->mid_map);
TALLOC_FREE(req->backend_data);
SAFE_FREE(req);
}
/****************************************************************************
Delete entries by mid from the change notify pending queue. Always send reply.
*****************************************************************************/
void remove_pending_change_notify_requests_by_mid(uint16 mid)
{
struct notify_mid_map *map;
for (map = notify_changes_by_mid; map; map = map->next) {
if (map->mid == mid) {
break;
}
}
if (map == NULL) {
return;
}
change_notify_reply_packet(map->req->request_buf, NT_STATUS_CANCELLED);
change_notify_remove_request(map->req);
}
/****************************************************************************
Delete entries by fnum from the change notify pending queue.
*****************************************************************************/
void remove_pending_change_notify_requests_by_fid(files_struct *fsp,
NTSTATUS status)
{
if (fsp->notify == NULL) {
return;
}
while (fsp->notify->requests != NULL) {
change_notify_reply_packet(
fsp->notify->requests->request_buf, status);
change_notify_remove_request(fsp->notify->requests);
}
}
/* notify message definition
Offset Data length.
0 SMB_DEV_T dev 8
8 SMB_INO_T inode 8
16 uint32 filter 4
20 uint32 action 4
24.. name
*/
#define MSG_NOTIFY_MESSAGE_SIZE 25 /* Includes at least the '\0' terminator */
struct notify_message {
SMB_DEV_T dev;
SMB_INO_T inode;
uint32 filter;
uint32 action;
char *name;
};
static DATA_BLOB notify_message_to_buf(const struct notify_message *msg)
{
DATA_BLOB result;
size_t len;
len = strlen(msg->name);
result = data_blob(NULL, MSG_NOTIFY_MESSAGE_SIZE + len);
if (!result.data) {
return result;
}
SDEV_T_VAL(result.data, 0, msg->dev);
SINO_T_VAL(result.data, 8, msg->inode);
SIVAL(result.data, 16, msg->filter);
SIVAL(result.data, 20, msg->action);
memcpy(result.data+24, msg->name, len+1);
return result;
}
static BOOL buf_to_notify_message(void *buf, size_t len,
struct notify_message *msg)
{
if (len < MSG_NOTIFY_MESSAGE_SIZE) {
DEBUG(0, ("Got invalid notify message of len %d\n",
(int)len));
return False;
}
msg->dev = DEV_T_VAL(buf, 0);
msg->inode = INO_T_VAL(buf, 8);
msg->filter = IVAL(buf, 16);
msg->action = IVAL(buf, 20);
msg->name = ((char *)buf)+24;
return True;
}
void notify_action(connection_struct *conn, const char *parent,
const char *name, uint32 filter, uint32_t action)
{
struct share_mode_lock *lck;
SMB_STRUCT_STAT sbuf;
int i;
struct notify_message msg;
DATA_BLOB blob;
struct process_id *pids;
int num_pids;
DEBUG(10, ("notify_action: parent=%s, name=%s, action=%u\n",
parent, name, (unsigned)action));
if (SMB_VFS_STAT(conn, parent, &sbuf) != 0) {
/*
* Not 100% critical, ignore failure
*/
return;
}
if (!(lck = get_share_mode_lock(NULL, sbuf.st_dev, sbuf.st_ino,
NULL, NULL))) {
return;
}
msg.dev = sbuf.st_dev;
msg.inode = sbuf.st_ino;
msg.filter = filter;
msg.action = action;
msg.name = CONST_DISCARD(char *, name);
blob = notify_message_to_buf(&msg);
if (blob.data == NULL) {
DEBUG(0, ("notify_message_to_buf failed\n"));
return;
}
pids = NULL;
num_pids = 0;
become_root_uid_only();
for (i=0; i<lck->num_share_modes; i++) {
struct share_mode_entry *e = &lck->share_modes[i];
int j;
struct process_id *tmp;
for (j=0; j<num_pids; j++) {
if (procid_equal(&e->pid, &pids[j])) {
break;
}
}
if (j < num_pids) {
/*
* Already sent to that process, skip it
*/
continue;
}
message_send_pid(lck->share_modes[i].pid, MSG_SMB_NOTIFY,
blob.data, blob.length, True);
if (!(tmp = TALLOC_REALLOC_ARRAY(lck, pids, struct process_id,
num_pids+1))) {
DEBUG(0, ("realloc failed\n"));
break;
}
pids = tmp;
pids[num_pids] = e->pid;
num_pids += 1;
}
unbecome_root_uid_only();
data_blob_free(&blob);
TALLOC_FREE(lck);
}
void notify_fname(connection_struct *conn, const char *path,
uint32 filter, uint32 action)
{
char *parent;
const char *name;
if (!parent_dirname_talloc(tmp_talloc_ctx(), path, &parent, &name)) {
return;
}
notify_action(conn, parent, name, filter, action);
TALLOC_FREE(parent);
}
void notify_fsp(files_struct *fsp, uint32 action, char *name)
{
struct notify_change *change, *changes;
if (fsp->notify == NULL) {
/*
* Nobody is waiting, don't queue
*/
return;
}
if (fsp->notify->requests != NULL) {
/*
* Someone is waiting for the change, trigger the reply
* immediately.
*
* TODO: do we have to walk the lists of requests pending?
*/
struct notify_change_request *req = fsp->notify->requests;
struct notify_change onechange;
if (name == NULL) {
/*
* Catch-all change, possibly from notify_hash.c
*/
change_notify_reply(req->request_buf,
req->max_param_count,
-1, NULL);
return;
}
onechange.action = action;
onechange.name = name;
change_notify_reply(req->request_buf, req->max_param_count,
1, &onechange);
change_notify_remove_request(req);
return;
}
/*
* Someone has triggered a notify previously, queue the change for
* later. TODO: Limit the number of changes queued, test how filters
* apply here. Do we have to store them?
*/
if ((fsp->notify->num_changes > 30) || (name == NULL)) {
/*
* W2k3 seems to store at most 30 changes.
*/
TALLOC_FREE(fsp->notify->changes);
fsp->notify->num_changes = -1;
return;
}
if (fsp->notify->num_changes == -1) {
return;
}
if (!(changes = TALLOC_REALLOC_ARRAY(
fsp->notify, fsp->notify->changes,
struct notify_change, fsp->notify->num_changes+1))) {
DEBUG(0, ("talloc_realloc failed\n"));
return;
}
fsp->notify->changes = changes;
change = &(fsp->notify->changes[fsp->notify->num_changes]);
if (!(change->name = talloc_strdup(changes, name))) {
DEBUG(0, ("talloc_strdup failed\n"));
return;
}
change->action = action;
fsp->notify->num_changes += 1;
return;
}
static void notify_message_callback(int msgtype, struct process_id pid,
void *buf, size_t len,
void *private_data)
{
struct notify_message msg;
files_struct *fsp;
if (!buf_to_notify_message(buf, len, &msg)) {
return;
}
DEBUG(10, ("Received notify_message for 0x%x/%.0f: %d\n",
(unsigned)msg.dev, (double)msg.inode, msg.action));
for(fsp = fsp_find_di_first(msg.dev, msg.inode); fsp;
fsp = fsp_find_di_next(fsp)) {
if ((fsp->notify != NULL)
&& (fsp->notify->requests != NULL)
&& (fsp->notify->requests->filter & msg.filter)) {
notify_fsp(fsp, msg.action, msg.name);
}
}
}
/****************************************************************************
Initialise the change notify subsystem.
****************************************************************************/
BOOL init_change_notify(void)
{
cnotify = NULL;
#if HAVE_KERNEL_CHANGE_NOTIFY
if (cnotify == NULL && lp_kernel_change_notify())
cnotify = kernel_notify_init(smbd_event_context());
#endif
#if HAVE_FAM_CHANGE_NOTIFY
if (cnotify == NULL && lp_fam_change_notify())
cnotify = fam_notify_init(smbd_event_context());
#endif
if (!cnotify) cnotify = hash_notify_init();
if (!cnotify) {
DEBUG(0,("Failed to init change notify system\n"));
return False;
}
message_register(MSG_SMB_NOTIFY, notify_message_callback, NULL);
return True;
}
struct sys_notify_context *sys_notify_context_create(struct share_params *scfg,
TALLOC_CTX *mem_ctx,
struct event_context *ev)
{
struct sys_notify_context *ctx;
if (!(ctx = TALLOC_P(mem_ctx, struct sys_notify_context))) {
DEBUG(0, ("talloc failed\n"));
return NULL;
}
ctx->ev = ev;
ctx->private_data = NULL;
return ctx;
}
NTSTATUS sys_notify_watch(struct sys_notify_context *ctx,
struct notify_entry *e,
void (*callback)(struct sys_notify_context *ctx,
void *private_data,
struct notify_event *ev),
void *private_data, void *handle)
{
return inotify_watch(ctx, e, callback, private_data, handle);
}
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