usr.sbin/pflogd/privsep_fdpass.c

   1 /*      $OpenBSD: privsep_fdpass.c,v 1.2 2004/08/13 02:51:48 djm Exp $  */
   2
   3 /*
   4  * Copyright 2001 Niels Provos <provos@citi.umich.edu>
   5  * All rights reserved.
   6  *
   7  * Copyright (c) 2002 Matthieu Herrb
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions
  12  * are met:
  13  *
  14  *    - Redistributions of source code must retain the above copyright
  15  *      notice, this list of conditions and the following disclaimer.
  16  *    - Redistributions in binary form must reproduce the above
  17  *      copyright notice, this list of conditions and the following
  18  *      disclaimer in the documentation and/or other materials provided
  19  *      with the distribution.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  29  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  31  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  32  * POSSIBILITY OF SUCH DAMAGE.
  33  */
  34 #include <sys/param.h>
  35 #include <sys/uio.h>
  36 #include <sys/types.h>
  37 #include <sys/socket.h>
  38 #include <sys/stat.h>
  39 #include <err.h>
  40 #include <errno.h>
  41 #include <fcntl.h>
  42 #include <signal.h>
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46 #include <unistd.h>
  47 #include "pflogd.h"
  48
  49 void
  50 send_fd(int sock, int fd)
  51 {
  52         struct msghdr msg;
  53         char tmp[CMSG_SPACE(sizeof(int))];
  54         struct cmsghdr *cmsg;
  55         struct iovec vec;
  56         int result = 0;
  57         ssize_t n;
  58
  59         memset(&msg, 0, sizeof(msg));
  60
  61         if (fd >= 0) {
  62                 msg.msg_control = (caddr_t)tmp;
  63                 msg.msg_controllen = CMSG_LEN(sizeof(int));
  64                 cmsg = CMSG_FIRSTHDR(&msg);
  65                 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
  66                 cmsg->cmsg_level = SOL_SOCKET;
  67                 cmsg->cmsg_type = SCM_RIGHTS;
  68                 *(int *)CMSG_DATA(cmsg) = fd;
  69         } else {
  70                 result = errno;
  71         }
  72
  73         vec.iov_base = (caddr_t)&result;
  74         vec.iov_len = sizeof(int);
  75         msg.msg_iov = &vec;
  76         msg.msg_iovlen = 1;
  77
  78         if ((n = sendmsg(sock, &msg, 0)) == -1)
  79                 warn("%s: sendmsg(%d)", __func__, sock);
  80         if (n != sizeof(int))
  81                 warnx("%s: sendmsg: expected sent 1 got %ld",
  82                     __func__, (long)n);
  83 }
  84
  85 int
  86 receive_fd(int sock)
  87 {
  88         struct msghdr msg;
  89         char tmp[CMSG_SPACE(sizeof(int))];
  90         struct cmsghdr *cmsg;
  91         struct iovec vec;
  92         ssize_t n;
  93         int result;
  94         int fd;
  95
  96         memset(&msg, 0, sizeof(msg));
  97         vec.iov_base = (caddr_t)&result;
  98         vec.iov_len = sizeof(int);
  99         msg.msg_iov = &vec;
 100         msg.msg_iovlen = 1;
 101         msg.msg_control = tmp;
 102         msg.msg_controllen = sizeof(tmp);
 103
 104         if ((n = recvmsg(sock, &msg, 0)) == -1)
 105                 warn("%s: recvmsg", __func__);
 106         if (n != sizeof(int))
 107                 warnx("%s: recvmsg: expected received 1 got %ld",
 108                     __func__, (long)n);
 109         if (result == 0) {
 110                 cmsg = CMSG_FIRSTHDR(&msg);
 111                 if (cmsg == NULL) {
 112                         warnx("%s: no message header", __func__);
 113                         return -1;
 114                 }
 115                 if (cmsg->cmsg_type != SCM_RIGHTS)
 116                         warnx("%s: expected type %d got %d", __func__,
 117                             SCM_RIGHTS, cmsg->cmsg_type);
 118                 fd = (*(int *)CMSG_DATA(cmsg));
 119                 return fd;
 120         } else {
 121                 errno = result;
 122                 return -1;
 123         }
 124 }