xref: /openbsd/usr.bin/ssh/msg.c (revision a6445c1d)
1 /* $OpenBSD: msg.c,v 1.15 2006/08/03 03:34:42 deraadt Exp $ */
2 /*
3  * Copyright (c) 2002 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 #include <sys/uio.h>
28 
29 #include <errno.h>
30 #include <stdio.h>
31 #include <string.h>
32 #include <unistd.h>
33 #include <stdarg.h>
34 
35 #include "buffer.h"
36 #include "log.h"
37 #include "atomicio.h"
38 #include "msg.h"
39 #include "misc.h"
40 
41 int
42 ssh_msg_send(int fd, u_char type, Buffer *m)
43 {
44 	u_char buf[5];
45 	u_int mlen = buffer_len(m);
46 
47 	debug3("ssh_msg_send: type %u", (unsigned int)type & 0xff);
48 
49 	put_u32(buf, mlen + 1);
50 	buf[4] = type;		/* 1st byte of payload is mesg-type */
51 	if (atomicio(vwrite, fd, buf, sizeof(buf)) != sizeof(buf)) {
52 		error("ssh_msg_send: write");
53 		return (-1);
54 	}
55 	if (atomicio(vwrite, fd, buffer_ptr(m), mlen) != mlen) {
56 		error("ssh_msg_send: write");
57 		return (-1);
58 	}
59 	return (0);
60 }
61 
62 int
63 ssh_msg_recv(int fd, Buffer *m)
64 {
65 	u_char buf[4];
66 	u_int msg_len;
67 
68 	debug3("ssh_msg_recv entering");
69 
70 	if (atomicio(read, fd, buf, sizeof(buf)) != sizeof(buf)) {
71 		if (errno != EPIPE)
72 			error("ssh_msg_recv: read: header");
73 		return (-1);
74 	}
75 	msg_len = get_u32(buf);
76 	if (msg_len > 256 * 1024) {
77 		error("ssh_msg_recv: read: bad msg_len %u", msg_len);
78 		return (-1);
79 	}
80 	buffer_clear(m);
81 	buffer_append_space(m, msg_len);
82 	if (atomicio(read, fd, buffer_ptr(m), msg_len) != msg_len) {
83 		error("ssh_msg_recv: read: %s", strerror(errno));
84 		return (-1);
85 	}
86 	return (0);
87 }
88