proto_socketpair.c revision 229945 
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_socketpair.c 229945 2012-01-10 22:39:07Z pjd $");
32
33#include <sys/types.h>
34#include <sys/socket.h>
35
36#include <errno.h>
37#include <stdbool.h>
38#include <stdint.h>
39#include <stdio.h>
40#include <string.h>
41#include <unistd.h>
42
43#include "pjdlog.h"
44#include "proto_impl.h"
45
46#define	SP_CTX_MAGIC	0x50c3741
47struct sp_ctx {
48	int			sp_magic;
49	int			sp_fd[2];
50	int			sp_side;
51#define	SP_SIDE_UNDEF		0
52#define	SP_SIDE_CLIENT		1
53#define	SP_SIDE_SERVER		2
54};
55
56static void sp_close(void *ctx);
57
58static int
59sp_client(const char *srcaddr, const char *dstaddr, void **ctxp)
60{
61	struct sp_ctx *spctx;
62	int ret;
63
64	if (strcmp(dstaddr, "socketpair://") != 0)
65		return (-1);
66
67	PJDLOG_ASSERT(srcaddr == NULL);
68
69	spctx = malloc(sizeof(*spctx));
70	if (spctx == NULL)
71		return (errno);
72
73	if (socketpair(PF_UNIX, SOCK_STREAM, 0, spctx->sp_fd) == -1) {
74		ret = errno;
75		free(spctx);
76		return (ret);
77	}
78
79	spctx->sp_side = SP_SIDE_UNDEF;
80	spctx->sp_magic = SP_CTX_MAGIC;
81	*ctxp = spctx;
82
83	return (0);
84}
85
86static int
87sp_send(void *ctx, const unsigned char *data, size_t size, int fd)
88{
89	struct sp_ctx *spctx = ctx;
90	int sock;
91
92	PJDLOG_ASSERT(spctx != NULL);
93	PJDLOG_ASSERT(spctx->sp_magic == SP_CTX_MAGIC);
94
95	switch (spctx->sp_side) {
96	case SP_SIDE_UNDEF:
97		/*
98		 * If the first operation done by the caller is proto_send(),
99		 * we assume this is the client.
100		 */
101		/* FALLTHROUGH */
102		spctx->sp_side = SP_SIDE_CLIENT;
103		/* Close other end. */
104		close(spctx->sp_fd[1]);
105		spctx->sp_fd[1] = -1;
106	case SP_SIDE_CLIENT:
107		PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
108		sock = spctx->sp_fd[0];
109		break;
110	case SP_SIDE_SERVER:
111		PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
112		sock = spctx->sp_fd[1];
113		break;
114	default:
115		PJDLOG_ABORT("Invalid socket side (%d).", spctx->sp_side);
116	}
117
118	/* Someone is just trying to decide about side. */
119	if (data == NULL)
120		return (0);
121
122	return (proto_common_send(sock, data, size, fd));
123}
124
125static int
126sp_recv(void *ctx, unsigned char *data, size_t size, int *fdp)
127{
128	struct sp_ctx *spctx = ctx;
129	int fd;
130
131	PJDLOG_ASSERT(spctx != NULL);
132	PJDLOG_ASSERT(spctx->sp_magic == SP_CTX_MAGIC);
133
134	switch (spctx->sp_side) {
135	case SP_SIDE_UNDEF:
136		/*
137		 * If the first operation done by the caller is proto_recv(),
138		 * we assume this is the server.
139		 */
140		/* FALLTHROUGH */
141		spctx->sp_side = SP_SIDE_SERVER;
142		/* Close other end. */
143		close(spctx->sp_fd[0]);
144		spctx->sp_fd[0] = -1;
145	case SP_SIDE_SERVER:
146		PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
147		fd = spctx->sp_fd[1];
148		break;
149	case SP_SIDE_CLIENT:
150		PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
151		fd = spctx->sp_fd[0];
152		break;
153	default:
154		PJDLOG_ABORT("Invalid socket side (%d).", spctx->sp_side);
155	}
156
157	/* Someone is just trying to decide about side. */
158	if (data == NULL)
159		return (0);
160
161	return (proto_common_recv(fd, data, size, fdp));
162}
163
164static int
165sp_descriptor(const void *ctx)
166{
167	const struct sp_ctx *spctx = ctx;
168
169	PJDLOG_ASSERT(spctx != NULL);
170	PJDLOG_ASSERT(spctx->sp_magic == SP_CTX_MAGIC);
171	PJDLOG_ASSERT(spctx->sp_side == SP_SIDE_CLIENT ||
172	    spctx->sp_side == SP_SIDE_SERVER);
173
174	switch (spctx->sp_side) {
175	case SP_SIDE_CLIENT:
176		PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
177		return (spctx->sp_fd[0]);
178	case SP_SIDE_SERVER:
179		PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
180		return (spctx->sp_fd[1]);
181	}
182
183	PJDLOG_ABORT("Invalid socket side (%d).", spctx->sp_side);
184}
185
186static void
187sp_close(void *ctx)
188{
189	struct sp_ctx *spctx = ctx;
190
191	PJDLOG_ASSERT(spctx != NULL);
192	PJDLOG_ASSERT(spctx->sp_magic == SP_CTX_MAGIC);
193
194	switch (spctx->sp_side) {
195	case SP_SIDE_UNDEF:
196		PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
197		close(spctx->sp_fd[0]);
198		spctx->sp_fd[0] = -1;
199		PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
200		close(spctx->sp_fd[1]);
201		spctx->sp_fd[1] = -1;
202		break;
203	case SP_SIDE_CLIENT:
204		PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
205		close(spctx->sp_fd[0]);
206		spctx->sp_fd[0] = -1;
207		PJDLOG_ASSERT(spctx->sp_fd[1] == -1);
208		break;
209	case SP_SIDE_SERVER:
210		PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
211		close(spctx->sp_fd[1]);
212		spctx->sp_fd[1] = -1;
213		PJDLOG_ASSERT(spctx->sp_fd[0] == -1);
214		break;
215	default:
216		PJDLOG_ABORT("Invalid socket side (%d).", spctx->sp_side);
217	}
218
219	spctx->sp_magic = 0;
220	free(spctx);
221}
222
223static struct proto sp_proto = {
224	.prt_name = "socketpair",
225	.prt_client = sp_client,
226	.prt_send = sp_send,
227	.prt_recv = sp_recv,
228	.prt_descriptor = sp_descriptor,
229	.prt_close = sp_close
230};
231
232static __constructor void
233sp_ctor(void)
234{
235
236	proto_register(&sp_proto, false);
237}
238