msg.c

   1 /* $OpenBSD: msg.c,v 1.14 2006/07/22 20:48:23 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 <string.h>
  31 #include <unistd.h>
  32
  33 #include "buffer.h"
  34 #include "log.h"
  35 #include "atomicio.h"
  36 #include "msg.h"
  37 #include "misc.h"
  38
  39 int
  40 ssh_msg_send(int fd, u_char type, Buffer *m)
  41 {
  42         u_char buf[5];
  43         u_int mlen = buffer_len(m);
  44
  45         debug3("ssh_msg_send: type %u", (unsigned int)type & 0xff);
  46
  47         put_u32(buf, mlen + 1);
  48         buf[4] = type;          /* 1st byte of payload is mesg-type */
  49         if (atomicio(vwrite, fd, buf, sizeof(buf)) != sizeof(buf)) {
  50                 error("ssh_msg_send: write");
  51                 return (-1);
  52         }
  53         if (atomicio(vwrite, fd, buffer_ptr(m), mlen) != mlen) {
  54                 error("ssh_msg_send: write");
  55                 return (-1);
  56         }
  57         return (0);
  58 }
  59
  60 int
  61 ssh_msg_recv(int fd, Buffer *m)
  62 {
  63         u_char buf[4];
  64         u_int msg_len;
  65
  66         debug3("ssh_msg_recv entering");
  67
  68         if (atomicio(read, fd, buf, sizeof(buf)) != sizeof(buf)) {
  69                 if (errno != EPIPE)
  70                         error("ssh_msg_recv: read: header");
  71                 return (-1);
  72         }
  73         msg_len = get_u32(buf);
  74         if (msg_len > 256 * 1024) {
  75                 error("ssh_msg_recv: read: bad msg_len %u", msg_len);
  76                 return (-1);
  77         }
  78         buffer_clear(m);
  79         buffer_append_space(m, msg_len);
  80         if (atomicio(read, fd, buffer_ptr(m), msg_len) != msg_len) {
  81                 error("ssh_msg_recv: read: %s", strerror(errno));
  82                 return (-1);
  83         }
  84         return (0);
  85 }