xref: /freebsd/sbin/hastd/proto_common.c (revision 01ab52c021a91c6b536f335ce3d8f60d2102e140)
1 /*-
2  * Copyright (c) 2009-2010 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/socket.h>
35 
36 #include <errno.h>
37 #include <stdlib.h>
38 #include <strings.h>
39 
40 #include "pjdlog.h"
41 #include "proto_impl.h"
42 
43 /* Maximum size of packet we want to use when sending data. */
44 #ifndef MAX_SEND_SIZE
45 #define	MAX_SEND_SIZE	32768
46 #endif
47 
48 static int
49 proto_descriptor_send(int sock, int fd)
50 {
51 	unsigned char ctrl[CMSG_SPACE(sizeof(fd))];
52 	struct msghdr msg;
53 	struct cmsghdr *cmsg;
54 
55 	PJDLOG_ASSERT(sock >= 0);
56 	PJDLOG_ASSERT(fd >= 0);
57 
58 	bzero(&msg, sizeof(msg));
59 	bzero(&ctrl, sizeof(ctrl));
60 
61 	msg.msg_iov = NULL;
62 	msg.msg_iovlen = 0;
63 	msg.msg_control = ctrl;
64 	msg.msg_controllen = sizeof(ctrl);
65 
66 	cmsg = CMSG_FIRSTHDR(&msg);
67 	cmsg->cmsg_level = SOL_SOCKET;
68 	cmsg->cmsg_type = SCM_RIGHTS;
69 	cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
70 	bcopy(&fd, CMSG_DATA(cmsg), sizeof(fd));
71 
72 	if (sendmsg(sock, &msg, 0) == -1)
73 		return (errno);
74 
75 	return (0);
76 }
77 
78 int
79 proto_common_send(int sock, const unsigned char *data, size_t size, int fd)
80 {
81 	ssize_t done;
82 	size_t sendsize;
83 
84 	PJDLOG_ASSERT(sock >= 0);
85 	PJDLOG_ASSERT(data != NULL);
86 	PJDLOG_ASSERT(size > 0);
87 
88 	do {
89 		sendsize = size < MAX_SEND_SIZE ? size : MAX_SEND_SIZE;
90 		done = send(sock, data, sendsize, MSG_NOSIGNAL);
91 		if (done == 0)
92 			return (ENOTCONN);
93 		else if (done < 0) {
94 			if (errno == EINTR)
95 				continue;
96 			return (errno);
97 		}
98 		data += done;
99 		size -= done;
100 	} while (size > 0);
101 
102 	if (fd == -1)
103 		return (0);
104 	return (proto_descriptor_send(sock, fd));
105 }
106 
107 #include <stdio.h>
108 static int
109 proto_descriptor_recv(int sock, int *fdp)
110 {
111 	unsigned char ctrl[CMSG_SPACE(sizeof(*fdp))];
112 	struct msghdr msg;
113 	struct cmsghdr *cmsg;
114 
115 	PJDLOG_ASSERT(sock >= 0);
116 	PJDLOG_ASSERT(fdp != NULL);
117 
118 	bzero(&msg, sizeof(msg));
119 	bzero(&ctrl, sizeof(ctrl));
120 
121 	msg.msg_iov = NULL;
122 	msg.msg_iovlen = 0;
123 	msg.msg_control = ctrl;
124 	msg.msg_controllen = sizeof(ctrl);
125 
126 	if (recvmsg(sock, &msg, 0) == -1)
127 		return (errno);
128 
129 	cmsg = CMSG_FIRSTHDR(&msg);
130 	if (cmsg->cmsg_level != SOL_SOCKET ||
131 	    cmsg->cmsg_type != SCM_RIGHTS) {
132 		return (EINVAL);
133 	}
134 	bcopy(CMSG_DATA(cmsg), fdp, sizeof(*fdp));
135 
136 	return (0);
137 }
138 
139 int
140 proto_common_recv(int sock, unsigned char *data, size_t size, int *fdp)
141 {
142 	ssize_t done;
143 
144 	PJDLOG_ASSERT(sock >= 0);
145 	PJDLOG_ASSERT(data != NULL);
146 	PJDLOG_ASSERT(size > 0);
147 
148 	do {
149 		done = recv(sock, data, size, MSG_WAITALL);
150 	} while (done == -1 && errno == EINTR);
151 	if (done == 0)
152 		return (ENOTCONN);
153 	else if (done < 0)
154 		return (errno);
155 	if (fdp == NULL)
156 		return (0);
157 	return (proto_descriptor_recv(sock, fdp));
158 }
159