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      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