crypto/openssh/msg.c

   1 /* $OpenBSD: msg.c,v 1.16 2015/01/15 09:40:00 djm 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 "sshbuf.h"
  38 #include "ssherr.h"
  39 #include "log.h"
  40 #include "atomicio.h"
  41 #include "msg.h"
  42 #include "misc.h"
  43
  44 int
  45 ssh_msg_send(int fd, u_char type, struct sshbuf *m)
  46 {
  47         u_char buf[5];
  48         u_int mlen = sshbuf_len(m);
  49
  50         debug3("ssh_msg_send: type %u", (unsigned int)type & 0xff);
  51
  52         put_u32(buf, mlen + 1);
  53         buf[4] = type;          /* 1st byte of payload is mesg-type */
  54         if (atomicio(vwrite, fd, buf, sizeof(buf)) != sizeof(buf)) {
  55                 error("ssh_msg_send: write");
  56                 return (-1);
  57         }
  58         if (atomicio(vwrite, fd, (u_char *)sshbuf_ptr(m), mlen) != mlen) {
  59                 error("ssh_msg_send: write");
  60                 return (-1);
  61         }
  62         return (0);
  63 }
  64
  65 int
  66 ssh_msg_recv(int fd, struct sshbuf *m)
  67 {
  68         u_char buf[4], *p;
  69         u_int msg_len;
  70         int r;
  71
  72         debug3("ssh_msg_recv entering");
  73
  74         if (atomicio(read, fd, buf, sizeof(buf)) != sizeof(buf)) {
  75                 if (errno != EPIPE)
  76                         error("ssh_msg_recv: read: header");
  77                 return (-1);
  78         }
  79         msg_len = get_u32(buf);
  80         if (msg_len > 256 * 1024) {
  81                 error("ssh_msg_recv: read: bad msg_len %u", msg_len);
  82                 return (-1);
  83         }
  84         sshbuf_reset(m);
  85         if ((r = sshbuf_reserve(m, msg_len, &p)) != 0) {
  86                 error("%s: buffer error: %s", __func__, ssh_err(r));
  87                 return -1;
  88         }
  89         if (atomicio(read, fd, p, msg_len) != msg_len) {
  90                 error("ssh_msg_recv: read: %s", strerror(errno));
  91                 return (-1);
  92         }
  93         return (0);
  94 }