1/* $OpenBSD: dispatch.c,v 1.31 2017/05/31 07:00:13 markus Exp $ */
2/*
3 * Copyright (c) 2000 Markus Friedl.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "includes.h"
27
28#include <sys/types.h>
29
30#include <signal.h>
31#include <stdarg.h>
32
33#include "ssh2.h"
34#include "log.h"
35#include "dispatch.h"
36#include "packet.h"
37#include "compat.h"
38#include "ssherr.h"
39
40int
41dispatch_protocol_error(int type, u_int32_t seq, struct ssh *ssh)
42{
43	int r;
44
45	logit("dispatch_protocol_error: type %d seq %u", type, seq);
46	if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED)) != 0 ||
47	    (r = sshpkt_put_u32(ssh, seq)) != 0 ||
48	    (r = sshpkt_send(ssh)) != 0 ||
49	    (r = ssh_packet_write_wait(ssh)) != 0)
50		sshpkt_fatal(ssh, __func__, r);
51	return 0;
52}
53
54int
55dispatch_protocol_ignore(int type, u_int32_t seq, struct ssh *ssh)
56{
57	logit("dispatch_protocol_ignore: type %d seq %u", type, seq);
58	return 0;
59}
60
61void
62ssh_dispatch_init(struct ssh *ssh, dispatch_fn *dflt)
63{
64	u_int i;
65	for (i = 0; i < DISPATCH_MAX; i++)
66		ssh->dispatch[i] = dflt;
67}
68
69void
70ssh_dispatch_range(struct ssh *ssh, u_int from, u_int to, dispatch_fn *fn)
71{
72	u_int i;
73
74	for (i = from; i <= to; i++) {
75		if (i >= DISPATCH_MAX)
76			break;
77		ssh->dispatch[i] = fn;
78	}
79}
80
81void
82ssh_dispatch_set(struct ssh *ssh, int type, dispatch_fn *fn)
83{
84	ssh->dispatch[type] = fn;
85}
86
87int
88ssh_dispatch_run(struct ssh *ssh, int mode, volatile sig_atomic_t *done)
89{
90	int r;
91	u_char type;
92	u_int32_t seqnr;
93
94	for (;;) {
95		if (mode == DISPATCH_BLOCK) {
96			r = ssh_packet_read_seqnr(ssh, &type, &seqnr);
97			if (r != 0)
98				return r;
99		} else {
100			r = ssh_packet_read_poll_seqnr(ssh, &type, &seqnr);
101			if (r != 0)
102				return r;
103			if (type == SSH_MSG_NONE)
104				return 0;
105		}
106		if (type > 0 && type < DISPATCH_MAX &&
107		    ssh->dispatch[type] != NULL) {
108			if (ssh->dispatch_skip_packets) {
109				debug2("skipped packet (type %u)", type);
110				ssh->dispatch_skip_packets--;
111				continue;
112			}
113			r = (*ssh->dispatch[type])(type, seqnr, ssh);
114			if (r != 0)
115				return r;
116		} else {
117			r = sshpkt_disconnect(ssh,
118			    "protocol error: rcvd type %d", type);
119			if (r != 0)
120				return r;
121			return SSH_ERR_DISCONNECTED;
122		}
123		if (done != NULL && *done)
124			return 0;
125	}
126}
127
128void
129ssh_dispatch_run_fatal(struct ssh *ssh, int mode, volatile sig_atomic_t *done)
130{
131	int r;
132
133	if ((r = ssh_dispatch_run(ssh, mode, done)) != 0)
134		sshpkt_fatal(ssh, __func__, r);
135}
136