xref: /openssh-portable/msg.c (revision 89b54900)
1 /* $OpenBSD: msg.c,v 1.19 2020/06/24 15:08:53 markus 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 "sshbuf.h"
38 #include "ssherr.h"
39 #include "log.h"
40 #include "atomicio.h"
41 #include "msg.h"
42 #include "misc.h"
43 
44 int
45 ssh_msg_send(int fd, u_char type, struct sshbuf *m)
46 {
47 	u_char buf[5];
48 	u_int mlen = sshbuf_len(m);
49 
50 	debug3("%s: type %u", __func__, (unsigned int)type & 0xff);
51 
52 	put_u32(buf, mlen + 1);
53 	buf[4] = type;		/* 1st byte of payload is mesg-type */
54 	if (atomicio(vwrite, fd, buf, sizeof(buf)) != sizeof(buf)) {
55 		error("%s: write: %s", __func__, strerror(errno));
56 		return (-1);
57 	}
58 	if (atomicio(vwrite, fd, sshbuf_mutable_ptr(m), mlen) != mlen) {
59 		error("%s: write: %s", __func__, strerror(errno));
60 		return (-1);
61 	}
62 	return (0);
63 }
64 
65 int
66 ssh_msg_recv(int fd, struct sshbuf *m)
67 {
68 	u_char buf[4], *p;
69 	u_int msg_len;
70 	int r;
71 
72 	debug3("ssh_msg_recv entering");
73 
74 	if (atomicio(read, fd, buf, sizeof(buf)) != sizeof(buf)) {
75 		if (errno != EPIPE)
76 			error("%s: read header: %s", __func__, strerror(errno));
77 		return (-1);
78 	}
79 	msg_len = get_u32(buf);
80 	if (msg_len > sshbuf_max_size(m)) {
81 		error("%s: read: bad msg_len %u", __func__, msg_len);
82 		return (-1);
83 	}
84 	sshbuf_reset(m);
85 	if ((r = sshbuf_reserve(m, msg_len, &p)) != 0) {
86 		error("%s: buffer error: %s", __func__, ssh_err(r));
87 		return -1;
88 	}
89 	if (atomicio(read, fd, p, msg_len) != msg_len) {
90 		error("%s: read: %s", __func__, strerror(errno));
91 		return (-1);
92 	}
93 	return (0);
94 }
95