usr.sbin/pflogd/privsep_fdpass.c

   1 /*      $OpenBSD: privsep_fdpass.c,v 1.1 2003/10/22 18:51:55 canacar Exp $      */
   2 /*      $DragonFly: src/usr.sbin/pflogd/privsep_fdpass.c,v 1.1 2004/09/21 21:25:28 joerg Exp $ */
   3
   4 /*
   5  * Copyright 2001 Niels Provos <provos@citi.umich.edu>
   6  * All rights reserved.
   7  *
   8  * Copyright (c) 2002 Matthieu Herrb
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, are permitted provided that the following conditions
  13  * are met:
  14  *
  15  *    - Redistributions of source code must retain the above copyright
  16  *      notice, this list of conditions and the following disclaimer.
  17  *    - Redistributions in binary form must reproduce the above
  18  *      copyright notice, this list of conditions and the following
  19  *      disclaimer in the documentation and/or other materials provided
  20  *      with the distribution.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  23  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  30  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  32  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  33  * POSSIBILITY OF SUCH DAMAGE.
  34  */
  35 #include <sys/param.h>
  36 #include <sys/uio.h>
  37 #include <sys/types.h>
  38 #include <sys/socket.h>
  39 #include <sys/stat.h>
  40 #include <err.h>
  41 #include <errno.h>
  42 #include <fcntl.h>
  43 #include <signal.h>
  44 #include <stdio.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47 #include <unistd.h>
  48 #include "pflogd.h"
  49
  50 void
  51 send_fd(int sock, int fd)
  52 {
  53         struct msghdr msg;
  54         char tmp[CMSG_SPACE(sizeof(int))];
  55         struct cmsghdr *cmsg;
  56         struct iovec vec;
  57         int result = 0;
  58         ssize_t n;
  59
  60         memset(&msg, 0, sizeof(msg));
  61
  62         if (fd >= 0) {
  63                 msg.msg_control = (caddr_t)tmp;
  64                 msg.msg_controllen = CMSG_LEN(sizeof(int));
  65                 cmsg = CMSG_FIRSTHDR(&msg);
  66                 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
  67                 cmsg->cmsg_level = SOL_SOCKET;
  68                 cmsg->cmsg_type = SCM_RIGHTS;
  69                 *(int *)CMSG_DATA(cmsg) = fd;
  70         } else {
  71                 result = errno;
  72         }
  73
  74         vec.iov_base = (caddr_t)&result;
  75         vec.iov_len = sizeof(int);
  76         msg.msg_iov = &vec;
  77         msg.msg_iovlen = 1;
  78
  79         if ((n = sendmsg(sock, &msg, 0)) == -1)
  80                 warn("%s: sendmsg(%d)", __func__, sock);
  81         if (n != sizeof(int))
  82                 warnx("%s: sendmsg: expected sent 1 got %ld",
  83                     __func__, (long)n);
  84 }
  85
  86 int
  87 receive_fd(int sock)
  88 {
  89         struct msghdr msg;
  90         char tmp[CMSG_SPACE(sizeof(int))];
  91         struct cmsghdr *cmsg;
  92         struct iovec vec;
  93         ssize_t n;
  94         int result;
  95         int fd;
  96
  97         memset(&msg, 0, sizeof(msg));
  98         vec.iov_base = (caddr_t)&result;
  99         vec.iov_len = sizeof(int);
 100         msg.msg_iov = &vec;
 101         msg.msg_iovlen = 1;
 102         msg.msg_control = tmp;
 103         msg.msg_controllen = sizeof(tmp);
 104
 105         if ((n = recvmsg(sock, &msg, 0)) == -1)
 106                 warn("%s: recvmsg", __func__);
 107         if (n != sizeof(int))
 108                 warnx("%s: recvmsg: expected received 1 got %ld",
 109                     __func__, (long)n);
 110         if (result == 0) {
 111                 cmsg = CMSG_FIRSTHDR(&msg);
 112                 if (cmsg->cmsg_type != SCM_RIGHTS)
 113                         warnx("%s: expected type %d got %d", __func__,
 114                             SCM_RIGHTS, cmsg->cmsg_type);
 115                 fd = (*(int *)CMSG_DATA(cmsg));
 116                 return fd;
 117         } else {
 118                 errno = result;
 119                 return -1;
 120         }
 121 }