1
0
mirror of https://github.com/samba-team/samba.git synced 2024-12-25 23:21:54 +03:00
samba-mirror/source3/libsmb/unexpected.c
2010-03-13 20:20:37 +01:00

207 lines
5.1 KiB
C

/*
Unix SMB/CIFS implementation.
handle unexpected packets
Copyright (C) Andrew Tridgell 2000
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/>.
*/
#include "includes.h"
static struct tdb_wrap *tdbd = NULL;
/* the key type used in the unexpected packet database */
struct unexpected_key {
enum packet_type packet_type;
time_t timestamp;
int count;
};
/****************************************************************************
All unexpected packets are passed in here, to be stored in a unexpected
packet database. This allows nmblookup and other tools to receive packets
erroneously sent to the wrong port by broken MS systems.
**************************************************************************/
void unexpected_packet(struct packet_struct *p)
{
static int count;
TDB_DATA kbuf, dbuf;
struct unexpected_key key;
char buf[1024];
int len=0;
uint32_t enc_ip;
if (!tdbd) {
tdbd = tdb_wrap_open(talloc_autofree_context(),
lock_path("unexpected.tdb"), 0,
TDB_CLEAR_IF_FIRST|TDB_DEFAULT,
O_RDWR | O_CREAT, 0644);
if (!tdbd) {
DEBUG(0,("Failed to open unexpected.tdb\n"));
return;
}
}
memset(buf,'\0',sizeof(buf));
/* Encode the ip addr and port. */
enc_ip = ntohl(p->ip.s_addr);
SIVAL(buf,0,enc_ip);
SSVAL(buf,4,p->port);
len = build_packet(&buf[6], sizeof(buf)-6, p) + 6;
ZERO_STRUCT(key); /* needed for potential alignment */
key.packet_type = p->packet_type;
key.timestamp = p->timestamp;
key.count = count++;
kbuf.dptr = (uint8_t *)&key;
kbuf.dsize = sizeof(key);
dbuf.dptr = (uint8_t *)buf;
dbuf.dsize = len;
tdb_store(tdbd->tdb, kbuf, dbuf, TDB_REPLACE);
}
static time_t lastt;
/****************************************************************************
Delete the record if it is too old.
**************************************************************************/
static int traverse_fn(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
{
struct unexpected_key key;
if (kbuf.dsize != sizeof(key)) {
tdb_delete(ttdb, kbuf);
}
memcpy(&key, kbuf.dptr, sizeof(key));
if (lastt - key.timestamp > NMBD_UNEXPECTED_TIMEOUT) {
tdb_delete(ttdb, kbuf);
}
return 0;
}
/****************************************************************************
Delete all old unexpected packets.
**************************************************************************/
void clear_unexpected(time_t t)
{
if (!tdbd) return;
if ((lastt != 0) && (t < lastt + NMBD_UNEXPECTED_TIMEOUT))
return;
lastt = t;
tdb_traverse(tdbd->tdb, traverse_fn, NULL);
}
struct receive_unexpected_state {
struct packet_struct *matched_packet;
int match_id;
enum packet_type match_type;
const char *match_name;
};
/****************************************************************************
tdb traversal fn to find a matching 137 packet.
**************************************************************************/
static int traverse_match(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf,
void *private_data)
{
struct receive_unexpected_state *state =
(struct receive_unexpected_state *)private_data;
struct unexpected_key key;
struct in_addr ip;
uint32_t enc_ip;
int port;
struct packet_struct *p;
if (kbuf.dsize != sizeof(key)) {
return 0;
}
memcpy(&key, kbuf.dptr, sizeof(key));
if (key.packet_type != state->match_type) return 0;
if (dbuf.dsize < 6) {
return 0;
}
/* Decode the ip addr and port. */
enc_ip = IVAL(dbuf.dptr,0);
ip.s_addr = htonl(enc_ip);
port = SVAL(dbuf.dptr,4);
p = parse_packet((char *)&dbuf.dptr[6],
dbuf.dsize-6,
state->match_type,
ip,
port);
if (!p)
return 0;
if ((state->match_type == NMB_PACKET &&
p->packet.nmb.header.name_trn_id == state->match_id) ||
(state->match_type == DGRAM_PACKET &&
match_mailslot_name(p, state->match_name))) {
state->matched_packet = p;
return -1;
}
free_packet(p);
return 0;
}
/****************************************************************************
Check for a particular packet in the unexpected packet queue.
**************************************************************************/
struct packet_struct *receive_unexpected(enum packet_type packet_type, int id,
const char *mailslot_name)
{
struct tdb_wrap *tdb2;
struct receive_unexpected_state state;
tdb2 = tdb_wrap_open(talloc_autofree_context(),
lock_path("unexpected.tdb"), 0, 0, O_RDONLY, 0);
if (!tdb2) return NULL;
state.matched_packet = NULL;
state.match_id = id;
state.match_type = packet_type;
state.match_name = mailslot_name;
tdb_traverse(tdb2->tdb, traverse_match, &state);
TALLOC_FREE(tdb2);
return state.matched_packet;
}