1/*
2   Unix SMB/CIFS implementation.
3   handle unexpected packets
4   Copyright (C) Andrew Tridgell 2000
5
6   This program is free software; you can redistribute it and/or modify
7   it under the terms of the GNU General Public License as published by
8   the Free Software Foundation; either version 2 of the License, or
9   (at your option) any later version.
10
11   This program is distributed in the hope that it will be useful,
12   but WITHOUT ANY WARRANTY; without even the implied warranty of
13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14   GNU General Public License for more details.
15
16   You should have received a copy of the GNU General Public License
17   along with this program; if not, write to the Free Software
18   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19
20*/
21
22#include "includes.h"
23
24static TDB_CONTEXT *tdbd = NULL;
25
26/* the key type used in the unexpeceted packet database */
27struct unexpected_key {
28	enum packet_type packet_type;
29	time_t timestamp;
30	int count;
31};
32
33
34
35/****************************************************************************
36 all unexpected packets are passed in here, to be stored in a unexpected
37 packet database. This allows nmblookup and other tools to receive packets
38 erroneoously sent to the wrong port by broken MS systems
39  **************************************************************************/
40void unexpected_packet(struct packet_struct *p)
41{
42	static int count;
43	TDB_DATA kbuf, dbuf;
44	struct unexpected_key key;
45	char buf[1024];
46	int len=0;
47
48	if (!tdbd) {
49		tdbd = tdb_open_log(lock_path("unexpected.tdb"), 0,
50			       TDB_CLEAR_IF_FIRST|TDB_DEFAULT,
51			       O_RDWR | O_CREAT, 0644);
52		if (!tdbd) {
53			DEBUG(0,("Failed to open unexpected.tdb\n"));
54			return;
55		}
56	}
57
58	memset(buf,'\0',sizeof(buf));
59
60	len = build_packet(buf, p);
61
62	key.packet_type = p->packet_type;
63	key.timestamp = p->timestamp;
64	key.count = count++;
65
66	kbuf.dptr = (char *)&key;
67	kbuf.dsize = sizeof(key);
68	dbuf.dptr = buf;
69	dbuf.dsize = len;
70
71	tdb_store(tdbd, kbuf, dbuf, TDB_REPLACE);
72}
73
74
75static time_t lastt;
76
77/****************************************************************************
78delete the record if it is too old
79  **************************************************************************/
80static int traverse_fn(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
81{
82	struct unexpected_key key;
83
84	memcpy(&key, kbuf.dptr, sizeof(key));
85
86	if (lastt - key.timestamp > NMBD_UNEXPECTED_TIMEOUT) {
87		tdb_delete(ttdb, kbuf);
88	}
89
90	return 0;
91}
92
93
94/****************************************************************************
95delete all old unexpected packets
96  **************************************************************************/
97void clear_unexpected(time_t t)
98{
99	if (!tdbd) return;
100
101	if ((lastt != 0) && (t < lastt + NMBD_UNEXPECTED_TIMEOUT))
102		return;
103
104	lastt = t;
105
106	tdb_traverse(tdbd, traverse_fn, NULL);
107}
108
109
110static struct packet_struct *matched_packet;
111static int match_id;
112static enum packet_type match_type;
113static const char *match_name;
114
115/****************************************************************************
116tdb traversal fn to find a matching 137 packet
117  **************************************************************************/
118static int traverse_match(TDB_CONTEXT *ttdb, TDB_DATA kbuf, TDB_DATA dbuf, void *state)
119{
120	struct unexpected_key key;
121	struct packet_struct *p;
122
123	memcpy(&key, kbuf.dptr, sizeof(key));
124
125	if (key.packet_type != match_type) return 0;
126
127	p = parse_packet(dbuf.dptr, dbuf.dsize, match_type);
128
129	if ((match_type == NMB_PACKET &&
130	     p->packet.nmb.header.name_trn_id == match_id) ||
131	    (match_type == DGRAM_PACKET &&
132	     match_mailslot_name(p, match_name))) {
133		matched_packet = p;
134		return -1;
135	}
136
137	free_packet(p);
138
139	return 0;
140}
141
142
143/****************************************************************************
144check for a particular packet in the unexpected packet queue
145  **************************************************************************/
146struct packet_struct *receive_unexpected(enum packet_type packet_type, int id,
147					 const char *mailslot_name)
148{
149	TDB_CONTEXT *tdb2;
150
151	tdb2 = tdb_open_log(lock_path("unexpected.tdb"), 0, 0, O_RDONLY, 0);
152	if (!tdb2) return NULL;
153
154	matched_packet = NULL;
155	match_id = id;
156	match_type = packet_type;
157	match_name = mailslot_name;
158
159	tdb_traverse(tdb2, traverse_match, NULL);
160
161	tdb_close(tdb2);
162
163	return matched_packet;
164}
165