1/* $OpenBSD: dispatch.c,v 1.33 2023/03/05 05:34:09 dtucker 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 "ssherr.h"
38
39int
40dispatch_protocol_error(int type, u_int32_t seq, struct ssh *ssh)
41{
42	int r;
43
44	logit("dispatch_protocol_error: type %d seq %u", type, seq);
45	if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED)) != 0 ||
46	    (r = sshpkt_put_u32(ssh, seq)) != 0 ||
47	    (r = sshpkt_send(ssh)) != 0 ||
48	    (r = ssh_packet_write_wait(ssh)) != 0)
49		sshpkt_fatal(ssh, r, "%s", __func__);
50	return 0;
51}
52
53int
54dispatch_protocol_ignore(int type, u_int32_t seq, struct ssh *ssh)
55{
56	logit("dispatch_protocol_ignore: type %d seq %u", type, seq);
57	return 0;
58}
59
60void
61ssh_dispatch_init(struct ssh *ssh, dispatch_fn *dflt)
62{
63	u_int i;
64	for (i = 0; i < DISPATCH_MAX; i++)
65		ssh->dispatch[i] = dflt;
66}
67
68void
69ssh_dispatch_range(struct ssh *ssh, u_int from, u_int to, dispatch_fn *fn)
70{
71	u_int i;
72
73	for (i = from; i <= to; i++) {
74		if (i >= DISPATCH_MAX)
75			break;
76		ssh->dispatch[i] = fn;
77	}
78}
79
80void
81ssh_dispatch_set(struct ssh *ssh, int type, dispatch_fn *fn)
82{
83	ssh->dispatch[type] = fn;
84}
85
86int
87ssh_dispatch_run(struct ssh *ssh, int mode, volatile sig_atomic_t *done)
88{
89	int r;
90	u_char type;
91	u_int32_t seqnr;
92
93	for (;;) {
94		if (mode == DISPATCH_BLOCK) {
95			r = ssh_packet_read_seqnr(ssh, &type, &seqnr);
96			if (r != 0)
97				return r;
98		} else {
99			r = ssh_packet_read_poll_seqnr(ssh, &type, &seqnr);
100			if (r != 0)
101				return r;
102			if (type == SSH_MSG_NONE)
103				return 0;
104		}
105		if (type > 0 && type < DISPATCH_MAX &&
106		    ssh->dispatch[type] != NULL) {
107			if (ssh->dispatch_skip_packets) {
108				debug2("skipped packet (type %u)", type);
109				ssh->dispatch_skip_packets--;
110				continue;
111			}
112			r = (*ssh->dispatch[type])(type, seqnr, ssh);
113			if (r != 0)
114				return r;
115		} else {
116			r = sshpkt_disconnect(ssh,
117			    "protocol error: rcvd type %d", type);
118			if (r != 0)
119				return r;
120			return SSH_ERR_DISCONNECTED;
121		}
122		if (done != NULL && *done)
123			return 0;
124	}
125}
126
127void
128ssh_dispatch_run_fatal(struct ssh *ssh, int mode, volatile sig_atomic_t *done)
129{
130	int r;
131
132	if ((r = ssh_dispatch_run(ssh, mode, done)) != 0)
133		sshpkt_fatal(ssh, r, "%s", __func__);
134}
135