1 /*
   2  * Copyright (c) 2002 Markus Friedl.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  16  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  18  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  19  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  20  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  22  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  23  */
  24 #include "includes.h"
  25 RCSID("$OpenBSD: msg.c,v 1.4 2002/07/01 16:15:25 deraadt Exp $");
  26 
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28 
  29 #include "buffer.h"
  30 #include "getput.h"
  31 #include "log.h"
  32 #include "atomicio.h"
  33 #include "msg.h"
  34 
  35 void
  36 ssh_msg_send(int fd, u_char type, Buffer *m)
  37 {
  38         u_char buf[5];
  39         u_int mlen = buffer_len(m);
  40 
  41         debug3("ssh_msg_send: type %u", (unsigned int)type & 0xff);
  42 
  43         PUT_32BIT(buf, mlen + 1);
  44         buf[4] = type;          /* 1st byte of payload is mesg-type */
  45         if (atomicio(write, fd, buf, sizeof(buf)) != sizeof(buf))
  46                 fatal("ssh_msg_send: write");
  47         if (atomicio(write, fd, buffer_ptr(m), mlen) != mlen)
  48                 fatal("ssh_msg_send: write");
  49 }
  50 
  51 int
  52 ssh_msg_recv(int fd, Buffer *m)
  53 {
  54         u_char buf[4];
  55         ssize_t res;
  56         u_int msg_len;
  57 
  58         debug3("ssh_msg_recv entering");
  59 
  60         res = atomicio(read, fd, buf, sizeof(buf));
  61         if (res != sizeof(buf)) {
  62                 if (res == 0)
  63                         return -1;
  64                 fatal("ssh_msg_recv: read: header %ld", (long)res);
  65         }
  66         msg_len = GET_32BIT(buf);
  67         if (msg_len > 256 * 1024)
  68                 fatal("ssh_msg_recv: read: bad msg_len %u", msg_len);
  69         buffer_clear(m);
  70         buffer_append_space(m, msg_len);
  71         res = atomicio(read, fd, buffer_ptr(m), msg_len);
  72         if (res != msg_len)
  73                 fatal("ssh_msg_recv: read: %ld != msg_len", (long)res);
  74         return 0;
  75 }