xref: /openssh-portable/dispatch.c (revision ad60b117)
1 /* $OpenBSD: dispatch.c,v 1.32 2019/01/19 21:33:13 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 "ssh2.h"
34 #include "log.h"
35 #include "dispatch.h"
36 #include "packet.h"
37 #include "compat.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