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1/* $OpenBSD: dispatch.c,v 1.34 2025/05/21 06:44:24 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 <sys/types.h>
27
28#include <signal.h>
29#include <stdarg.h>
30
31#include "ssh2.h"
32#include "log.h"
33#include "dispatch.h"
34#include "packet.h"
35#include "ssherr.h"
36
37int
38dispatch_protocol_error(int type, u_int32_t seq, struct ssh *ssh)
39{
40 int r;
41
42 logit_f("type %d seq %u", type, seq);
43 if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED)) != 0 ||
44 (r = sshpkt_put_u32(ssh, seq)) != 0 ||
45 (r = sshpkt_send(ssh)) != 0 ||
46 (r = ssh_packet_write_wait(ssh)) != 0)
47 sshpkt_fatal(ssh, r, "%s", __func__);
48 return 0;
49}
50
51int
52dispatch_protocol_ignore(int type, u_int32_t seq, struct ssh *ssh)
53{
54 logit_f("type %d seq %u", type, seq);
55 return 0;
56}
57
58void
59ssh_dispatch_init(struct ssh *ssh, dispatch_fn *dflt)
60{
61 u_int i;
62 for (i = 0; i < DISPATCH_MAX; i++)
63 ssh->dispatch[i] = dflt;
64}
65
66void
67ssh_dispatch_range(struct ssh *ssh, u_int from, u_int to, dispatch_fn *fn)
68{
69 u_int i;
70
71 for (i = from; i <= to; i++) {
72 if (i >= DISPATCH_MAX)
73 break;
74 ssh->dispatch[i] = fn;
75 }
76}
77
78void
79ssh_dispatch_set(struct ssh *ssh, int type, dispatch_fn *fn)
80{
81 ssh->dispatch[type] = fn;
82}
83
84int
85ssh_dispatch_run(struct ssh *ssh, int mode, volatile sig_atomic_t *done)
86{
87 int r;
88 u_char type;
89 u_int32_t seqnr;
90
91 for (;;) {
92 if (mode == DISPATCH_BLOCK) {
93 r = ssh_packet_read_seqnr(ssh, &type, &seqnr);
94 if (r != 0)
95 return r;
96 } else {
97 r = ssh_packet_read_poll_seqnr(ssh, &type, &seqnr);
98 if (r != 0)
99 return r;
100 if (type == SSH_MSG_NONE)
101 return 0;
102 }
103 if (type > 0 && type < DISPATCH_MAX &&
104 ssh->dispatch[type] != NULL) {
105 if (ssh->dispatch_skip_packets) {
106 debug2("skipped packet (type %u)", type);
107 ssh->dispatch_skip_packets--;
108 continue;
109 }
110 r = (*ssh->dispatch[type])(type, seqnr, ssh);
111 if (r != 0)
112 return r;
113 } else {
114 r = sshpkt_disconnect(ssh,
115 "protocol error: rcvd type %d", type);
116 if (r != 0)
117 return r;
118 return SSH_ERR_DISCONNECTED;
119 }
120 if (done != NULL && *done)
121 return 0;
122 }
123}
124
125void
126ssh_dispatch_run_fatal(struct ssh *ssh, int mode, volatile sig_atomic_t *done)
127{
128 int r;
129
130 if ((r = ssh_dispatch_run(ssh, mode, done)) != 0)
131 sshpkt_fatal(ssh, r, "%s", __func__);
132}