misc.c revision 302408 
1/*-
2 * Copyright (c) 2012 The FreeBSD Foundation
3 * All rights reserved.
4 *
5 * This software was developed by Pawel Jakub Dawidek under sponsorship from
6 * the FreeBSD Foundation.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD: stable/11/tools/regression/capsicum/syscalls/misc.c 247606 2013-03-02 01:00:26Z pjd $");
32
33#include <sys/types.h>
34#include <sys/select.h>
35#include <sys/socket.h>
36
37#include <assert.h>
38#include <errno.h>
39#include <stdlib.h>
40#include <strings.h>
41
42#include "misc.h"
43
44int
45pdwait(int pfd)
46{
47	fd_set fdset;
48
49	FD_ZERO(&fdset);
50	FD_SET(pfd, &fdset);
51
52	return (select(pfd + 1, NULL, &fdset, NULL, NULL) == -1 ? -1 : 0);
53}
54
55int
56descriptor_send(int sock, int fd)
57{
58	unsigned char ctrl[CMSG_SPACE(sizeof(fd))];
59	struct msghdr msg;
60	struct cmsghdr *cmsg;
61
62	assert(sock >= 0);
63	assert(fd >= 0);
64
65	bzero(&msg, sizeof(msg));
66	bzero(&ctrl, sizeof(ctrl));
67
68	msg.msg_iov = NULL;
69	msg.msg_iovlen = 0;
70	msg.msg_control = ctrl;
71	msg.msg_controllen = sizeof(ctrl);
72
73	cmsg = CMSG_FIRSTHDR(&msg);
74	cmsg->cmsg_level = SOL_SOCKET;
75	cmsg->cmsg_type = SCM_RIGHTS;
76	cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
77	bcopy(&fd, CMSG_DATA(cmsg), sizeof(fd));
78
79	if (sendmsg(sock, &msg, 0) == -1)
80		return (errno);
81
82	return (0);
83}
84
85int
86descriptor_recv(int sock, int *fdp)
87{
88	unsigned char ctrl[CMSG_SPACE(sizeof(*fdp))];
89	struct msghdr msg;
90	struct cmsghdr *cmsg;
91	struct iovec iov;
92	int val;
93
94	assert(sock >= 0);
95	assert(fdp != NULL);
96
97	bzero(&msg, sizeof(msg));
98	bzero(&ctrl, sizeof(ctrl));
99
100#if 1
101	/*
102	 * This doesn't really make sense, as we don't plan to receive any
103	 * data, but if no buffer is provided and recv(2) returns 0 without
104	 * control message. Must be kernel bug.
105	 */
106	iov.iov_base = &val;
107	iov.iov_len = sizeof(val);
108	msg.msg_iov = &iov;
109	msg.msg_iovlen = 1;
110#else
111	msg.msg_iov = NULL;
112	msg.msg_iovlen = 0;
113#endif
114	msg.msg_control = ctrl;
115	msg.msg_controllen = sizeof(ctrl);
116
117	if (recvmsg(sock, &msg, 0) == -1)
118		return (errno);
119
120	cmsg = CMSG_FIRSTHDR(&msg);
121	if (cmsg == NULL || cmsg->cmsg_level != SOL_SOCKET ||
122	    cmsg->cmsg_type != SCM_RIGHTS) {
123		return (EINVAL);
124	}
125	bcopy(CMSG_DATA(cmsg), fdp, sizeof(*fdp));
126
127	return (0);
128}
129