proto_common.c revision 220270 
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: head/sbin/hastd/proto_common.c 220270 2011-04-02 09:22:06Z pjd $");
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
48static int
49proto_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
78int
79proto_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
118static int
119proto_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
149int
150proto_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