msg.c

   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 }