xref: /freebsd/crypto/openssh/msg.c (revision fcb560670601b2a4d87bb31d7531c8dcc37ee71b)
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 "includes.h"
27 
28 #include <sys/types.h>
29 #include <sys/uio.h>
30 
31 #include <errno.h>
32 #include <stdio.h>
33 #include <string.h>
34 #include <unistd.h>
35 #include <stdarg.h>
36 
37 #include "buffer.h"
38 #include "log.h"
39 #include "atomicio.h"
40 #include "msg.h"
41 #include "misc.h"
42 
43 int
44 ssh_msg_send(int fd, u_char type, Buffer *m)
45 {
46 	u_char buf[5];
47 	u_int mlen = buffer_len(m);
48 
49 	debug3("ssh_msg_send: type %u", (unsigned int)type & 0xff);
50 
51 	put_u32(buf, mlen + 1);
52 	buf[4] = type;		/* 1st byte of payload is mesg-type */
53 	if (atomicio(vwrite, fd, buf, sizeof(buf)) != sizeof(buf)) {
54 		error("ssh_msg_send: write");
55 		return (-1);
56 	}
57 	if (atomicio(vwrite, fd, buffer_ptr(m), mlen) != mlen) {
58 		error("ssh_msg_send: write");
59 		return (-1);
60 	}
61 	return (0);
62 }
63 
64 int
65 ssh_msg_recv(int fd, Buffer *m)
66 {
67 	u_char buf[4];
68 	u_int msg_len;
69 
70 	debug3("ssh_msg_recv entering");
71 
72 	if (atomicio(read, fd, buf, sizeof(buf)) != sizeof(buf)) {
73 		if (errno != EPIPE)
74 			error("ssh_msg_recv: read: header");
75 		return (-1);
76 	}
77 	msg_len = get_u32(buf);
78 	if (msg_len > 256 * 1024) {
79 		error("ssh_msg_recv: read: bad msg_len %u", msg_len);
80 		return (-1);
81 	}
82 	buffer_clear(m);
83 	buffer_append_space(m, msg_len);
84 	if (atomicio(read, fd, buffer_ptr(m), msg_len) != msg_len) {
85 		error("ssh_msg_recv: read: %s", strerror(errno));
86 		return (-1);
87 	}
88 	return (0);
89 }
90