xref: /freebsd/crypto/openssh/msg.c (revision 6b3455a7665208c366849f0b2b3bc916fb97516e)
1 /*
2  * Copyright (c) 2002 Markus Friedl.  All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23  */
24 #include "includes.h"
25 RCSID("$OpenBSD: msg.c,v 1.7 2003/11/17 09:45:39 djm Exp $");
26 
27 #include "buffer.h"
28 #include "getput.h"
29 #include "log.h"
30 #include "atomicio.h"
31 #include "msg.h"
32 
33 int
34 ssh_msg_send(int fd, u_char type, Buffer *m)
35 {
36 	u_char buf[5];
37 	u_int mlen = buffer_len(m);
38 
39 	debug3("ssh_msg_send: type %u", (unsigned int)type & 0xff);
40 
41 	PUT_32BIT(buf, mlen + 1);
42 	buf[4] = type;		/* 1st byte of payload is mesg-type */
43 	if (atomicio(vwrite, fd, buf, sizeof(buf)) != sizeof(buf)) {
44 		error("ssh_msg_send: write");
45 		return (-1);
46 	}
47 	if (atomicio(vwrite, fd, buffer_ptr(m), mlen) != mlen) {
48 		error("ssh_msg_send: write");
49 		return (-1);
50 	}
51 	return (0);
52 }
53 
54 int
55 ssh_msg_recv(int fd, Buffer *m)
56 {
57 	u_char buf[4];
58 	ssize_t res;
59 	u_int msg_len;
60 
61 	debug3("ssh_msg_recv entering");
62 
63 	res = atomicio(read, fd, buf, sizeof(buf));
64 	if (res != sizeof(buf)) {
65 		if (res != 0)
66 			error("ssh_msg_recv: read: header %ld", (long)res);
67 		return (-1);
68 	}
69 	msg_len = GET_32BIT(buf);
70 	if (msg_len > 256 * 1024) {
71 		error("ssh_msg_recv: read: bad msg_len %u", msg_len);
72 		return (-1);
73 	}
74 	buffer_clear(m);
75 	buffer_append_space(m, msg_len);
76 	res = atomicio(read, fd, buffer_ptr(m), msg_len);
77 	if (res != msg_len) {
78 		error("ssh_msg_recv: read: %ld != msg_len", (long)res);
79 		return (-1);
80 	}
81 	return (0);
82 }
83