dispatch.c revision 295367 
1/* $OpenBSD: dispatch.c,v 1.27 2015/05/01 07:10:01 djm 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 "ssh1.h"
34#include "ssh2.h"
35#include "log.h"
36#include "dispatch.h"
37#include "packet.h"
38#include "compat.h"
39#include "ssherr.h"
40
41int
42dispatch_protocol_error(int type, u_int32_t seq, void *ctx)
43{
44	struct ssh *ssh = active_state; /* XXX */
45	int r;
46
47	logit("dispatch_protocol_error: type %d seq %u", type, seq);
48	if (!compat20)
49		fatal("protocol error");
50	if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED)) != 0 ||
51	    (r = sshpkt_put_u32(ssh, seq)) != 0 ||
52	    (r = sshpkt_send(ssh)) != 0 ||
53	    (r = ssh_packet_write_wait(ssh)) != 0)
54		sshpkt_fatal(ssh, __func__, r);
55	return 0;
56}
57
58int
59dispatch_protocol_ignore(int type, u_int32_t seq, void *ssh)
60{
61	logit("dispatch_protocol_ignore: type %d seq %u", type, seq);
62	return 0;
63}
64
65void
66ssh_dispatch_init(struct ssh *ssh, dispatch_fn *dflt)
67{
68	u_int i;
69	for (i = 0; i < DISPATCH_MAX; i++)
70		ssh->dispatch[i] = dflt;
71}
72
73void
74ssh_dispatch_range(struct ssh *ssh, u_int from, u_int to, dispatch_fn *fn)
75{
76	u_int i;
77
78	for (i = from; i <= to; i++) {
79		if (i >= DISPATCH_MAX)
80			break;
81		ssh->dispatch[i] = fn;
82	}
83}
84
85void
86ssh_dispatch_set(struct ssh *ssh, int type, dispatch_fn *fn)
87{
88	ssh->dispatch[type] = fn;
89}
90
91int
92ssh_dispatch_run(struct ssh *ssh, int mode, volatile sig_atomic_t *done,
93    void *ctxt)
94{
95	int r;
96	u_char type;
97	u_int32_t seqnr;
98
99	for (;;) {
100		if (mode == DISPATCH_BLOCK) {
101			r = ssh_packet_read_seqnr(ssh, &type, &seqnr);
102			if (r != 0)
103				return r;
104		} else {
105			r = ssh_packet_read_poll_seqnr(ssh, &type, &seqnr);
106			if (r != 0)
107				return r;
108			if (type == SSH_MSG_NONE)
109				return 0;
110		}
111		if (type > 0 && type < DISPATCH_MAX &&
112		    ssh->dispatch[type] != NULL) {
113			if (ssh->dispatch_skip_packets) {
114				debug2("skipped packet (type %u)", type);
115				ssh->dispatch_skip_packets--;
116				continue;
117			}
118			/* XXX 'ssh' will replace 'ctxt' later */
119			r = (*ssh->dispatch[type])(type, seqnr, ctxt);
120			if (r != 0)
121				return r;
122		} else {
123			r = sshpkt_disconnect(ssh,
124			    "protocol error: rcvd type %d", type);
125			if (r != 0)
126				return r;
127			return SSH_ERR_DISCONNECTED;
128		}
129		if (done != NULL && *done)
130			return 0;
131	}
132}
133
134void
135ssh_dispatch_run_fatal(struct ssh *ssh, int mode, volatile sig_atomic_t *done,
136    void *ctxt)
137{
138	int r;
139
140	if ((r = ssh_dispatch_run(ssh, mode, done, ctxt)) != 0)
141		sshpkt_fatal(ssh, __func__, r);
142}
143