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("$FreeBSD$");
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
44 int
pdwait(int pfd)45 pdwait(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
55 int
descriptor_send(int sock,int fd)56 descriptor_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
85 int
descriptor_recv(int sock,int * fdp)86 descriptor_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