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1/* $OpenBSD: msg.c,v 1.22 2026/02/14 00:18:34 jsg 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
28#include <errno.h>
29#include <string.h>
30#include <unistd.h>
31#include <stdarg.h>
32
33#include "sshbuf.h"
34#include "log.h"
35#include "atomicio.h"
36#include "msg.h"
37#include "misc.h"
38
39int
40ssh_msg_send(int fd, u_char type, struct sshbuf *m)
41{
42 u_char buf[5];
43 u_int mlen = sshbuf_len(m);
44
45 debug3_f("type %u len %zu", (unsigned int)type & 0xff, sshbuf_len(m));
46
47 put_u32(buf, mlen + 1);
48 buf[4] = type; /* 1st byte of payload is mesg-type */
49 if (atomicio(vwrite, fd, buf, sizeof(buf)) != sizeof(buf)) {
50 error_f("write: %s", strerror(errno));
51 return (-1);
52 }
53 if (atomicio(vwrite, fd, sshbuf_mutable_ptr(m), mlen) != mlen) {
54 error_f("write: %s", strerror(errno));
55 return (-1);
56 }
57 debug3_f("done");
58 return (0);
59}
60
61int
62ssh_msg_recv(int fd, struct sshbuf *m)
63{
64 u_char buf[4], *p;
65 u_int msg_len;
66 int r;
67
68 debug3("ssh_msg_recv entering");
69
70 if (atomicio(read, fd, buf, sizeof(buf)) != sizeof(buf)) {
71 if (errno != EPIPE)
72 error_f("read header: %s", strerror(errno));
73 return (-1);
74 }
75 msg_len = get_u32(buf);
76 if (msg_len > sshbuf_max_size(m)) {
77 error_f("read: bad msg_len %u", msg_len);
78 return (-1);
79 }
80 sshbuf_reset(m);
81 if ((r = sshbuf_reserve(m, msg_len, &p)) != 0) {
82 error_fr(r, "reserve");
83 return -1;
84 }
85 if (atomicio(read, fd, p, msg_len) != msg_len) {
86 error_f("read: %s", strerror(errno));
87 return (-1);
88 }
89 return (0);
90}