1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2009-2010 The FreeBSD Foundation
5 *
6 * This software was developed by Pawel Jakub Dawidek under sponsorship from
7 * the FreeBSD Foundation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <sys/cdefs.h>
32 #include <sys/types.h>
33 #include <sys/socket.h>
34
35 #include <errno.h>
36 #include <stdbool.h>
37 #include <stdint.h>
38 #include <stdio.h>
39 #include <string.h>
40 #include <unistd.h>
41
42 #include "pjdlog.h"
43 #include "proto_impl.h"
44
45 #define SP_CTX_MAGIC 0x50c3741
46 struct sp_ctx {
47 int sp_magic;
48 int sp_fd[2];
49 int sp_side;
50 #define SP_SIDE_UNDEF 0
51 #define SP_SIDE_CLIENT 1
52 #define SP_SIDE_SERVER 2
53 };
54
55 static void sp_close(void *ctx);
56
57 static int
sp_client(const char * srcaddr,const char * dstaddr,void ** ctxp)58 sp_client(const char *srcaddr, const char *dstaddr, void **ctxp)
59 {
60 struct sp_ctx *spctx;
61 int ret;
62
63 if (strcmp(dstaddr, "socketpair://") != 0)
64 return (-1);
65
66 PJDLOG_ASSERT(srcaddr == NULL);
67
68 spctx = malloc(sizeof(*spctx));
69 if (spctx == NULL)
70 return (errno);
71
72 if (socketpair(PF_UNIX, SOCK_STREAM, 0, spctx->sp_fd) == -1) {
73 ret = errno;
74 free(spctx);
75 return (ret);
76 }
77
78 spctx->sp_side = SP_SIDE_UNDEF;
79 spctx->sp_magic = SP_CTX_MAGIC;
80 *ctxp = spctx;
81
82 return (0);
83 }
84
85 static int
sp_send(void * ctx,const unsigned char * data,size_t size,int fd)86 sp_send(void *ctx, const unsigned char *data, size_t size, int fd)
87 {
88 struct sp_ctx *spctx = ctx;
89 int sock;
90
91 PJDLOG_ASSERT(spctx != NULL);
92 PJDLOG_ASSERT(spctx->sp_magic == SP_CTX_MAGIC);
93
94 switch (spctx->sp_side) {
95 case SP_SIDE_UNDEF:
96 /*
97 * If the first operation done by the caller is proto_send(),
98 * we assume this is the client.
99 */
100 /* FALLTHROUGH */
101 spctx->sp_side = SP_SIDE_CLIENT;
102 /* Close other end. */
103 close(spctx->sp_fd[1]);
104 spctx->sp_fd[1] = -1;
105 case SP_SIDE_CLIENT:
106 PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
107 sock = spctx->sp_fd[0];
108 break;
109 case SP_SIDE_SERVER:
110 PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
111 sock = spctx->sp_fd[1];
112 break;
113 default:
114 PJDLOG_ABORT("Invalid socket side (%d).", spctx->sp_side);
115 }
116
117 /* Someone is just trying to decide about side. */
118 if (data == NULL)
119 return (0);
120
121 return (proto_common_send(sock, data, size, fd));
122 }
123
124 static int
sp_recv(void * ctx,unsigned char * data,size_t size,int * fdp)125 sp_recv(void *ctx, unsigned char *data, size_t size, int *fdp)
126 {
127 struct sp_ctx *spctx = ctx;
128 int fd;
129
130 PJDLOG_ASSERT(spctx != NULL);
131 PJDLOG_ASSERT(spctx->sp_magic == SP_CTX_MAGIC);
132
133 switch (spctx->sp_side) {
134 case SP_SIDE_UNDEF:
135 /*
136 * If the first operation done by the caller is proto_recv(),
137 * we assume this is the server.
138 */
139 /* FALLTHROUGH */
140 spctx->sp_side = SP_SIDE_SERVER;
141 /* Close other end. */
142 close(spctx->sp_fd[0]);
143 spctx->sp_fd[0] = -1;
144 case SP_SIDE_SERVER:
145 PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
146 fd = spctx->sp_fd[1];
147 break;
148 case SP_SIDE_CLIENT:
149 PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
150 fd = spctx->sp_fd[0];
151 break;
152 default:
153 PJDLOG_ABORT("Invalid socket side (%d).", spctx->sp_side);
154 }
155
156 /* Someone is just trying to decide about side. */
157 if (data == NULL)
158 return (0);
159
160 return (proto_common_recv(fd, data, size, fdp));
161 }
162
163 static int
sp_descriptor(const void * ctx)164 sp_descriptor(const void *ctx)
165 {
166 const struct sp_ctx *spctx = ctx;
167
168 PJDLOG_ASSERT(spctx != NULL);
169 PJDLOG_ASSERT(spctx->sp_magic == SP_CTX_MAGIC);
170 PJDLOG_ASSERT(spctx->sp_side == SP_SIDE_CLIENT ||
171 spctx->sp_side == SP_SIDE_SERVER);
172
173 switch (spctx->sp_side) {
174 case SP_SIDE_CLIENT:
175 PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
176 return (spctx->sp_fd[0]);
177 case SP_SIDE_SERVER:
178 PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
179 return (spctx->sp_fd[1]);
180 }
181
182 PJDLOG_ABORT("Invalid socket side (%d).", spctx->sp_side);
183 }
184
185 static void
sp_close(void * ctx)186 sp_close(void *ctx)
187 {
188 struct sp_ctx *spctx = ctx;
189
190 PJDLOG_ASSERT(spctx != NULL);
191 PJDLOG_ASSERT(spctx->sp_magic == SP_CTX_MAGIC);
192
193 switch (spctx->sp_side) {
194 case SP_SIDE_UNDEF:
195 PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
196 close(spctx->sp_fd[0]);
197 spctx->sp_fd[0] = -1;
198 PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
199 close(spctx->sp_fd[1]);
200 spctx->sp_fd[1] = -1;
201 break;
202 case SP_SIDE_CLIENT:
203 PJDLOG_ASSERT(spctx->sp_fd[0] >= 0);
204 close(spctx->sp_fd[0]);
205 spctx->sp_fd[0] = -1;
206 PJDLOG_ASSERT(spctx->sp_fd[1] == -1);
207 break;
208 case SP_SIDE_SERVER:
209 PJDLOG_ASSERT(spctx->sp_fd[1] >= 0);
210 close(spctx->sp_fd[1]);
211 spctx->sp_fd[1] = -1;
212 PJDLOG_ASSERT(spctx->sp_fd[0] == -1);
213 break;
214 default:
215 PJDLOG_ABORT("Invalid socket side (%d).", spctx->sp_side);
216 }
217
218 spctx->sp_magic = 0;
219 free(spctx);
220 }
221
222 static struct proto sp_proto = {
223 .prt_name = "socketpair",
224 .prt_client = sp_client,
225 .prt_send = sp_send,
226 .prt_recv = sp_recv,
227 .prt_descriptor = sp_descriptor,
228 .prt_close = sp_close
229 };
230
231 static __constructor void
sp_ctor(void)232 sp_ctor(void)
233 {
234
235 proto_register(&sp_proto, false);
236 }
237