xref: /freebsd/sbin/hastd/proto_common.c (revision 3a0b818f596a9016e8fa2437c80653baa8f12ead)
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 
86 	if (data == NULL) {
87 		/* The caller is just trying to decide about direction. */
88 
89 		PJDLOG_ASSERT(size == 0);
90 
91 		if (shutdown(sock, SHUT_RD) == -1)
92 			return (errno);
93 		return (0);
94 	}
95 
96 	PJDLOG_ASSERT(data != NULL);
97 	PJDLOG_ASSERT(size > 0);
98 
99 	do {
100 		sendsize = size < MAX_SEND_SIZE ? size : MAX_SEND_SIZE;
101 		done = send(sock, data, sendsize, MSG_NOSIGNAL);
102 		if (done == 0)
103 			return (ENOTCONN);
104 		else if (done < 0) {
105 			if (errno == EINTR)
106 				continue;
107 			return (errno);
108 		}
109 		data += done;
110 		size -= done;
111 	} while (size > 0);
112 
113 	if (fd == -1)
114 		return (0);
115 	return (proto_descriptor_send(sock, fd));
116 }
117 
118 static int
119 proto_descriptor_recv(int sock, int *fdp)
120 {
121 	unsigned char ctrl[CMSG_SPACE(sizeof(*fdp))];
122 	struct msghdr msg;
123 	struct cmsghdr *cmsg;
124 
125 	PJDLOG_ASSERT(sock >= 0);
126 	PJDLOG_ASSERT(fdp != NULL);
127 
128 	bzero(&msg, sizeof(msg));
129 	bzero(&ctrl, sizeof(ctrl));
130 
131 	msg.msg_iov = NULL;
132 	msg.msg_iovlen = 0;
133 	msg.msg_control = ctrl;
134 	msg.msg_controllen = sizeof(ctrl);
135 
136 	if (recvmsg(sock, &msg, 0) == -1)
137 		return (errno);
138 
139 	cmsg = CMSG_FIRSTHDR(&msg);
140 	if (cmsg->cmsg_level != SOL_SOCKET ||
141 	    cmsg->cmsg_type != SCM_RIGHTS) {
142 		return (EINVAL);
143 	}
144 	bcopy(CMSG_DATA(cmsg), fdp, sizeof(*fdp));
145 
146 	return (0);
147 }
148 
149 int
150 proto_common_recv(int sock, unsigned char *data, size_t size, int *fdp)
151 {
152 	ssize_t done;
153 
154 	PJDLOG_ASSERT(sock >= 0);
155 
156 	if (data == NULL) {
157 		/* The caller is just trying to decide about direction. */
158 
159 		PJDLOG_ASSERT(size == 0);
160 
161 		if (shutdown(sock, SHUT_WR) == -1)
162 			return (errno);
163 		return (0);
164 	}
165 
166 	PJDLOG_ASSERT(data != NULL);
167 	PJDLOG_ASSERT(size > 0);
168 
169 	do {
170 		done = recv(sock, data, size, MSG_WAITALL);
171 	} while (done == -1 && errno == EINTR);
172 	if (done == 0)
173 		return (ENOTCONN);
174 	else if (done < 0)
175 		return (errno);
176 	if (fdp == NULL)
177 		return (0);
178 	return (proto_descriptor_recv(sock, fdp));
179 }
180