crypto/openssh/msg.c

   1 /* $OpenBSD: msg.c,v 1.21 2024/05/17 00:30:24 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_f("type %u len %zu", (unsigned int)type & 0xff, sshbuf_len(m));
  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_f("write: %s", strerror(errno));
  56                 return (-1);
  57         }
  58         if (atomicio(vwrite, fd, sshbuf_mutable_ptr(m), mlen) != mlen) {
  59                 error_f("write: %s", strerror(errno));
  60                 return (-1);
  61         }
  62         debug3_f("done");
  63         return (0);
  64 }
  65
  66 int
  67 ssh_msg_recv(int fd, struct sshbuf *m)
  68 {
  69         u_char buf[4], *p;
  70         u_int msg_len;
  71         int r;
  72
  73         debug3("ssh_msg_recv entering");
  74
  75         if (atomicio(read, fd, buf, sizeof(buf)) != sizeof(buf)) {
  76                 if (errno != EPIPE)
  77                         error_f("read header: %s", strerror(errno));
  78                 return (-1);
  79         }
  80         msg_len = get_u32(buf);
  81         if (msg_len > sshbuf_max_size(m)) {
  82                 error_f("read: bad msg_len %u", msg_len);
  83                 return (-1);
  84         }
  85         sshbuf_reset(m);
  86         if ((r = sshbuf_reserve(m, msg_len, &p)) != 0) {
  87                 error_fr(r, "reserve");
  88                 return -1;
  89         }
  90         if (atomicio(read, fd, p, msg_len) != msg_len) {
  91                 error_f("read: %s", strerror(errno));
  92                 return (-1);
  93         }
  94         return (0);
  95 }