1 /* $NetBSD: dispatch.c,v 1.11 2023/07/26 17:58:15 christos Exp $ */
2 /* $OpenBSD: dispatch.c,v 1.33 2023/03/05 05:34:09 dtucker Exp $ */
3 /*
4 * Copyright (c) 2000 Markus Friedl. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include "includes.h"
28 __RCSID("$NetBSD: dispatch.c,v 1.11 2023/07/26 17:58:15 christos Exp $");
29 #include <sys/types.h>
30
31 #include <signal.h>
32 #include <stdarg.h>
33
34 #include "ssh2.h"
35 #include "log.h"
36 #include "dispatch.h"
37 #include "packet.h"
38 #include "ssherr.h"
39
40 int
dispatch_protocol_error(int type,u_int32_t seq,struct ssh * ssh)41 dispatch_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, r, "%s", __func__);
51 return 0;
52 }
53
54 int
dispatch_protocol_ignore(int type,u_int32_t seq,struct ssh * ssh)55 dispatch_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
61 void
ssh_dispatch_init(struct ssh * ssh,dispatch_fn * dflt)62 ssh_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
69 void
ssh_dispatch_range(struct ssh * ssh,u_int from,u_int to,dispatch_fn * fn)70 ssh_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
81 void
ssh_dispatch_set(struct ssh * ssh,int type,dispatch_fn * fn)82 ssh_dispatch_set(struct ssh *ssh, int type, dispatch_fn *fn)
83 {
84 ssh->dispatch[type] = fn;
85 }
86
87 int
ssh_dispatch_run(struct ssh * ssh,int mode,volatile sig_atomic_t * done)88 ssh_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
128 void
ssh_dispatch_run_fatal(struct ssh * ssh,int mode,volatile sig_atomic_t * done)129 ssh_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, r, "%s", __func__);
135 }
136