proto_common.c revision 218148 
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 218148 2011-01-31 23:46:36Z 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
48int
49proto_common_send(int sock, const unsigned char *data, size_t size)
50{
51	ssize_t done;
52	size_t sendsize;
53
54	PJDLOG_ASSERT(sock >= 0);
55	PJDLOG_ASSERT(data != NULL);
56	PJDLOG_ASSERT(size > 0);
57
58	do {
59		sendsize = size < MAX_SEND_SIZE ? size : MAX_SEND_SIZE;
60		done = send(sock, data, sendsize, MSG_NOSIGNAL);
61		if (done == 0)
62			return (ENOTCONN);
63		else if (done < 0) {
64			if (errno == EINTR)
65				continue;
66			return (errno);
67		}
68		data += done;
69		size -= done;
70	} while (size > 0);
71
72	return (0);
73}
74
75int
76proto_common_recv(int sock, unsigned char *data, size_t size)
77{
78	ssize_t done;
79
80	PJDLOG_ASSERT(sock >= 0);
81	PJDLOG_ASSERT(data != NULL);
82	PJDLOG_ASSERT(size > 0);
83
84	do {
85		done = recv(sock, data, size, MSG_WAITALL);
86	} while (done == -1 && errno == EINTR);
87	if (done == 0)
88		return (ENOTCONN);
89	else if (done < 0)
90		return (errno);
91	return (0);
92}
93
94int
95proto_common_descriptor_send(int sock, int fd)
96{
97	unsigned char ctrl[CMSG_SPACE(sizeof(fd))];
98	struct msghdr msg;
99	struct cmsghdr *cmsg;
100
101	PJDLOG_ASSERT(sock >= 0);
102	PJDLOG_ASSERT(fd >= 0);
103
104	bzero(&msg, sizeof(msg));
105	bzero(&ctrl, sizeof(ctrl));
106
107	msg.msg_iov = NULL;
108	msg.msg_iovlen = 0;
109	msg.msg_control = ctrl;
110	msg.msg_controllen = sizeof(ctrl);
111
112	cmsg = CMSG_FIRSTHDR(&msg);
113	cmsg->cmsg_level = SOL_SOCKET;
114	cmsg->cmsg_type = SCM_RIGHTS;
115	cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
116	bcopy(&fd, CMSG_DATA(cmsg), sizeof(fd));
117
118	if (sendmsg(sock, &msg, 0) == -1)
119		return (errno);
120
121	return (0);
122}
123
124int
125proto_common_descriptor_recv(int sock, int *fdp)
126{
127	unsigned char ctrl[CMSG_SPACE(sizeof(*fdp))];
128	struct msghdr msg;
129	struct cmsghdr *cmsg;
130
131	PJDLOG_ASSERT(sock >= 0);
132	PJDLOG_ASSERT(fdp != NULL);
133
134	bzero(&msg, sizeof(msg));
135	bzero(&ctrl, sizeof(ctrl));
136
137	msg.msg_iov = NULL;
138	msg.msg_iovlen = 0;
139	msg.msg_control = ctrl;
140	msg.msg_controllen = sizeof(ctrl);
141
142	if (recvmsg(sock, &msg, 0) == -1)
143		return (errno);
144
145	cmsg = CMSG_FIRSTHDR(&msg);
146	if (cmsg->cmsg_level != SOL_SOCKET ||
147	    cmsg->cmsg_type == SCM_RIGHTS) {
148		return (EINVAL);
149	}
150	bcopy(CMSG_DATA(cmsg), fdp, sizeof(*fdp));
151
152	return (0);
153}
154