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/types.h>
31 #include <sys/select.h>
32 #include <sys/socket.h>
33
34 #include <assert.h>
35 #include <errno.h>
36 #include <stdlib.h>
37 #include <strings.h>
38
39 #include "misc.h"
40
41 int
pdwait(int pfd)42 pdwait(int pfd)
43 {
44 fd_set fdset;
45
46 FD_ZERO(&fdset);
47 FD_SET(pfd, &fdset);
48
49 return (select(pfd + 1, NULL, &fdset, NULL, NULL) == -1 ? -1 : 0);
50 }
51
52 int
descriptor_send(int sock,int fd)53 descriptor_send(int sock, int fd)
54 {
55 unsigned char ctrl[CMSG_SPACE(sizeof(fd))];
56 struct msghdr msg;
57 struct cmsghdr *cmsg;
58
59 assert(sock >= 0);
60 assert(fd >= 0);
61
62 bzero(&msg, sizeof(msg));
63 bzero(&ctrl, sizeof(ctrl));
64
65 msg.msg_iov = NULL;
66 msg.msg_iovlen = 0;
67 msg.msg_control = ctrl;
68 msg.msg_controllen = sizeof(ctrl);
69
70 cmsg = CMSG_FIRSTHDR(&msg);
71 cmsg->cmsg_level = SOL_SOCKET;
72 cmsg->cmsg_type = SCM_RIGHTS;
73 cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
74 bcopy(&fd, CMSG_DATA(cmsg), sizeof(fd));
75
76 if (sendmsg(sock, &msg, 0) == -1)
77 return (errno);
78
79 return (0);
80 }
81
82 int
descriptor_recv(int sock,int * fdp)83 descriptor_recv(int sock, int *fdp)
84 {
85 unsigned char ctrl[CMSG_SPACE(sizeof(*fdp))];
86 struct msghdr msg;
87 struct cmsghdr *cmsg;
88 struct iovec iov;
89 int val;
90
91 assert(sock >= 0);
92 assert(fdp != NULL);
93
94 bzero(&msg, sizeof(msg));
95 bzero(&ctrl, sizeof(ctrl));
96
97 #if 1
98 /*
99 * This doesn't really make sense, as we don't plan to receive any
100 * data, but if no buffer is provided and recv(2) returns 0 without
101 * control message. Must be kernel bug.
102 */
103 iov.iov_base = &val;
104 iov.iov_len = sizeof(val);
105 msg.msg_iov = &iov;
106 msg.msg_iovlen = 1;
107 #else
108 msg.msg_iov = NULL;
109 msg.msg_iovlen = 0;
110 #endif
111 msg.msg_control = ctrl;
112 msg.msg_controllen = sizeof(ctrl);
113
114 if (recvmsg(sock, &msg, 0) == -1)
115 return (errno);
116
117 cmsg = CMSG_FIRSTHDR(&msg);
118 if (cmsg == NULL || cmsg->cmsg_level != SOL_SOCKET ||
119 cmsg->cmsg_type != SCM_RIGHTS) {
120 return (EINVAL);
121 }
122 bcopy(CMSG_DATA(cmsg), fdp, sizeof(*fdp));
123
124 return (0);
125 }
126