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 "includes.h" 27 28 #include <sys/types.h> 29 30 #include <errno.h> 31 #include <string.h> 32 #include <unistd.h> 33 #include <stdarg.h> 34 35 #include "sshbuf.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, struct sshbuf *m) 43 { 44 u_char buf[5]; 45 u_int mlen = sshbuf_len(m); 46 47 debug3_f("type %u len %zu", (unsigned int)type & 0xff, sshbuf_len(m)); 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_f("write: %s", strerror(errno)); 53 return (-1); 54 } 55 if (atomicio(vwrite, fd, sshbuf_mutable_ptr(m), mlen) != mlen) { 56 error_f("write: %s", strerror(errno)); 57 return (-1); 58 } 59 debug3_f("done"); 60 return (0); 61 } 62 63 int 64 ssh_msg_recv(int fd, struct sshbuf *m) 65 { 66 u_char buf[4], *p; 67 u_int msg_len; 68 int r; 69 70 debug3("ssh_msg_recv entering"); 71 72 if (atomicio(read, fd, buf, sizeof(buf)) != sizeof(buf)) { 73 if (errno != EPIPE) 74 error_f("read header: %s", strerror(errno)); 75 return (-1); 76 } 77 msg_len = get_u32(buf); 78 if (msg_len > sshbuf_max_size(m)) { 79 error_f("read: bad msg_len %u", msg_len); 80 return (-1); 81 } 82 sshbuf_reset(m); 83 if ((r = sshbuf_reserve(m, msg_len, &p)) != 0) { 84 error_fr(r, "reserve"); 85 return -1; 86 } 87 if (atomicio(read, fd, p, msg_len) != msg_len) { 88 error_f("read: %s", strerror(errno)); 89 return (-1); 90 } 91 return (0); 92 } 93