proto_socketpair.c revision 293161 
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/types.h>
31#include <sys/socket.h>
32
33#include <errno.h>
34#include <stdbool.h>
35#include <stdint.h>
36#include <stdio.h>
37#include <string.h>
38#include <unistd.h>
39
40#include "pjdlog.h"
41#include "proto_impl.h"
42
43#define	SP_CTX_MAGIC	0x50c3741
44struct sp_ctx {
45	int			sp_magic;
46	int			sp_fd[2];
47	int			sp_side;
48#define	SP_SIDE_UNDEF		0
49#define	SP_SIDE_CLIENT		1
50#define	SP_SIDE_SERVER		2
51};
52
53static void sp_close(void *ctx);
54
55static int
56sp_connect(const char *srcaddr, const char *dstaddr, int timeout, void **ctxp)
57{
58	struct sp_ctx *spctx;
59	int error;
60
61	PJDLOG_ASSERT(dstaddr != NULL);
62	PJDLOG_ASSERT(timeout >= -1);
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		error = errno;
75		free(spctx);
76		return (error);
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_wrap(int fd, bool client, void **ctxp)
88{
89	struct sp_ctx *spctx;
90
91	PJDLOG_ASSERT(fd >= 0);
92
93	spctx = malloc(sizeof(*spctx));
94	if (spctx == NULL)
95		return (errno);
96
97	if (client) {
98		spctx->sp_side = SP_SIDE_CLIENT;
99		spctx->sp_fd[0] = fd;
100		spctx->sp_fd[1] = -1;
101	} else {
102		spctx->sp_side = SP_SIDE_SERVER;
103		spctx->sp_fd[0] = -1;
104		spctx->sp_fd[1] = fd;
105	}
106	spctx->sp_magic = SP_CTX_MAGIC;
107	*ctxp = spctx;
108
109	return (0);
110}
111
112static int
113sp_send(void *ctx, const unsigned char *data, size_t size, int fd)
114{
115	struct sp_ctx *spctx = ctx;
116	int sock;
117
118	PJDLOG_ASSERT(spctx != NULL);
119	PJDLOG_ASSERT(spctx->sp_magic == SP_CTX_MAGIC);
120
121	switch (spctx->sp_side) {
122	case SP_SIDE_UNDEF:
123		/*
124		 * If the first operation done by the caller is proto_send(),
125		 * we assume this is the client.
126		 */
127		/* FALLTHROUGH */
128		spctx->sp_side = SP_SIDE_CLIENT;
129		/* Close other end. */
130		close(spctx->sp_fd[1]);
131		spctx->sp_fd[1] = -1;
132	case SP_SIDE_CLIENT:
133		PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
134		sock = spctx->sp_fd[0];
135		break;
136	case SP_SIDE_SERVER:
137		PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
138		sock = spctx->sp_fd[1];
139		break;
140	default:
141		PJDLOG_ABORT("Invalid socket side (%d).", spctx->sp_side);
142	}
143
144	/* Someone is just trying to decide about side. */
145	if (data == NULL)
146		return (0);
147
148	return (proto_common_send(sock, data, size, fd));
149}
150
151static int
152sp_recv(void *ctx, unsigned char *data, size_t size, int *fdp)
153{
154	struct sp_ctx *spctx = ctx;
155	int sock;
156
157	PJDLOG_ASSERT(spctx != NULL);
158	PJDLOG_ASSERT(spctx->sp_magic == SP_CTX_MAGIC);
159
160	switch (spctx->sp_side) {
161	case SP_SIDE_UNDEF:
162		/*
163		 * If the first operation done by the caller is proto_recv(),
164		 * we assume this is the server.
165		 */
166		/* FALLTHROUGH */
167		spctx->sp_side = SP_SIDE_SERVER;
168		/* Close other end. */
169		close(spctx->sp_fd[0]);
170		spctx->sp_fd[0] = -1;
171	case SP_SIDE_SERVER:
172		PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
173		sock = spctx->sp_fd[1];
174		break;
175	case SP_SIDE_CLIENT:
176		PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
177		sock = spctx->sp_fd[0];
178		break;
179	default:
180		PJDLOG_ABORT("Invalid socket side (%d).", spctx->sp_side);
181	}
182
183	/* Someone is just trying to decide about side. */
184	if (data == NULL)
185		return (0);
186
187	return (proto_common_recv(sock, data, size, fdp));
188}
189
190static int
191sp_descriptor(const void *ctx)
192{
193	const struct sp_ctx *spctx = ctx;
194
195	PJDLOG_ASSERT(spctx != NULL);
196	PJDLOG_ASSERT(spctx->sp_magic == SP_CTX_MAGIC);
197	PJDLOG_ASSERT(spctx->sp_side == SP_SIDE_CLIENT ||
198	    spctx->sp_side == SP_SIDE_SERVER);
199
200	switch (spctx->sp_side) {
201	case SP_SIDE_CLIENT:
202		PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
203		return (spctx->sp_fd[0]);
204	case SP_SIDE_SERVER:
205		PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
206		return (spctx->sp_fd[1]);
207	}
208
209	PJDLOG_ABORT("Invalid socket side (%d).", spctx->sp_side);
210}
211
212static void
213sp_close(void *ctx)
214{
215	struct sp_ctx *spctx = ctx;
216
217	PJDLOG_ASSERT(spctx != NULL);
218	PJDLOG_ASSERT(spctx->sp_magic == SP_CTX_MAGIC);
219
220	switch (spctx->sp_side) {
221	case SP_SIDE_UNDEF:
222		PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
223		close(spctx->sp_fd[0]);
224		spctx->sp_fd[0] = -1;
225		PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
226		close(spctx->sp_fd[1]);
227		spctx->sp_fd[1] = -1;
228		break;
229	case SP_SIDE_CLIENT:
230		PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
231		close(spctx->sp_fd[0]);
232		spctx->sp_fd[0] = -1;
233		PJDLOG_ASSERT(spctx->sp_fd[1] == -1);
234		break;
235	case SP_SIDE_SERVER:
236		PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
237		close(spctx->sp_fd[1]);
238		spctx->sp_fd[1] = -1;
239		PJDLOG_ASSERT(spctx->sp_fd[0] == -1);
240		break;
241	default:
242		PJDLOG_ABORT("Invalid socket side (%d).", spctx->sp_side);
243	}
244
245	spctx->sp_magic = 0;
246	free(spctx);
247}
248
249static struct proto sp_proto = {
250	.prt_name = "socketpair",
251	.prt_connect = sp_connect,
252	.prt_wrap = sp_wrap,
253	.prt_send = sp_send,
254	.prt_recv = sp_recv,
255	.prt_descriptor = sp_descriptor,
256	.prt_close = sp_close
257};
258
259static __constructor void
260sp_ctor(void)
261{
262
263	proto_register(&sp_proto, false);
264}
265