msg.c

   1 /* $OpenBSD: msg.c,v 1.13 2006/07/17 01:31:09 stevesk 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 #include "includes.h"
  26
  27 #include <sys/types.h>
  28
  29 #include <errno.h>
  30 #include <unistd.h>
  31
  32 #include "buffer.h"
  33 #include "log.h"
  34 #include "atomicio.h"
  35 #include "msg.h"
  36 #include "misc.h"
  37
  38 int
  39 ssh_msg_send(int fd, u_char type, Buffer *m)
  40 {
  41         u_char buf[5];
  42         u_int mlen = buffer_len(m);
  43
  44         debug3("ssh_msg_send: type %u", (unsigned int)type & 0xff);
  45
  46         put_u32(buf, mlen + 1);
  47         buf[4] = type;          /* 1st byte of payload is mesg-type */
  48         if (atomicio(vwrite, fd, buf, sizeof(buf)) != sizeof(buf)) {
  49                 error("ssh_msg_send: write");
  50                 return (-1);
  51         }
  52         if (atomicio(vwrite, fd, buffer_ptr(m), mlen) != mlen) {
  53                 error("ssh_msg_send: write");
  54                 return (-1);
  55         }
  56         return (0);
  57 }
  58
  59 int
  60 ssh_msg_recv(int fd, Buffer *m)
  61 {
  62         u_char buf[4];
  63         u_int msg_len;
  64
  65         debug3("ssh_msg_recv entering");
  66
  67         if (atomicio(read, fd, buf, sizeof(buf)) != sizeof(buf)) {
  68                 if (errno != EPIPE)
  69                         error("ssh_msg_recv: read: header");
  70                 return (-1);
  71         }
  72         msg_len = get_u32(buf);
  73         if (msg_len > 256 * 1024) {
  74                 error("ssh_msg_recv: read: bad msg_len %u", msg_len);
  75                 return (-1);
  76         }
  77         buffer_clear(m);
  78         buffer_append_space(m, msg_len);
  79         if (atomicio(read, fd, buffer_ptr(m), msg_len) != msg_len) {
  80                 error("ssh_msg_recv: read: %s", strerror(errno));
  81                 return (-1);
  82         }
  83         return (0);
  84 }