xref: /freebsd/sys/kern/uipc_domain.c (revision d0b2dbfa0ecf2bbc9709efc5e20baf8e4b44bbbf)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1982, 1986, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)uipc_domain.c	8.2 (Berkeley) 10/18/93
32  */
33 
34 #include <sys/cdefs.h>
35 #include <sys/param.h>
36 #include <sys/socket.h>
37 #include <sys/protosw.h>
38 #include <sys/domain.h>
39 #include <sys/eventhandler.h>
40 #include <sys/epoch.h>
41 #include <sys/mbuf.h>
42 #include <sys/kernel.h>
43 #include <sys/lock.h>
44 #include <sys/mutex.h>
45 #include <sys/rmlock.h>
46 #include <sys/socketvar.h>
47 #include <sys/systm.h>
48 
49 #include <machine/atomic.h>
50 
51 #include <net/vnet.h>
52 
53 struct domainhead domains = SLIST_HEAD_INITIALIZER(&domains);
54 int domain_init_status = 1;
55 static struct mtx dom_mtx;		/* domain list lock */
56 MTX_SYSINIT(domain, &dom_mtx, "domain list", MTX_DEF);
57 
58 static int
59 pr_accept_notsupp(struct socket *so, struct sockaddr **nam)
60 {
61 	return (EOPNOTSUPP);
62 }
63 
64 static int
65 pr_aio_queue_notsupp(struct socket *so, struct kaiocb *job)
66 {
67 	return (EOPNOTSUPP);
68 }
69 
70 static int
71 pr_bind_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
72 {
73 	return (EOPNOTSUPP);
74 }
75 
76 static int
77 pr_bindat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
78     struct thread *td)
79 {
80 	return (EOPNOTSUPP);
81 }
82 
83 static int
84 pr_connect_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
85 {
86 	return (EOPNOTSUPP);
87 }
88 
89 static int
90 pr_connectat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
91     struct thread *td)
92 {
93 	return (EOPNOTSUPP);
94 }
95 
96 static int
97 pr_connect2_notsupp(struct socket *so1, struct socket *so2)
98 {
99 	return (EOPNOTSUPP);
100 }
101 
102 static int
103 pr_control_notsupp(struct socket *so, u_long cmd, void *data,
104     struct ifnet *ifp, struct thread *td)
105 {
106 	return (EOPNOTSUPP);
107 }
108 
109 static int
110 pr_disconnect_notsupp(struct socket *so)
111 {
112 	return (EOPNOTSUPP);
113 }
114 
115 static int
116 pr_listen_notsupp(struct socket *so, int backlog, struct thread *td)
117 {
118 	return (EOPNOTSUPP);
119 }
120 
121 static int
122 pr_peeraddr_notsupp(struct socket *so, struct sockaddr **nam)
123 {
124 	return (EOPNOTSUPP);
125 }
126 
127 static int
128 pr_rcvd_notsupp(struct socket *so, int flags)
129 {
130 	return (EOPNOTSUPP);
131 }
132 
133 static int
134 pr_rcvoob_notsupp(struct socket *so, struct mbuf *m, int flags)
135 {
136 	return (EOPNOTSUPP);
137 }
138 
139 static int
140 pr_send_notsupp(struct socket *so, int flags, struct mbuf *m,
141     struct sockaddr *addr, struct mbuf *control, struct thread *td)
142 {
143 	if (control != NULL)
144 		m_freem(control);
145 	if ((flags & PRUS_NOTREADY) == 0)
146 		m_freem(m);
147 	return (EOPNOTSUPP);
148 }
149 
150 static int
151 pr_ready_notsupp(struct socket *so, struct mbuf *m, int count)
152 {
153 	return (EOPNOTSUPP);
154 }
155 
156 static int
157 pr_shutdown_notsupp(struct socket *so)
158 {
159 	return (EOPNOTSUPP);
160 }
161 
162 static int
163 pr_sockaddr_notsupp(struct socket *so, struct sockaddr **nam)
164 {
165 	return (EOPNOTSUPP);
166 }
167 
168 static int
169 pr_sosend_notsupp(struct socket *so, struct sockaddr *addr, struct uio *uio,
170     struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
171 {
172 	return (EOPNOTSUPP);
173 }
174 
175 static int
176 pr_soreceive_notsupp(struct socket *so, struct sockaddr **paddr,
177     struct uio *uio, struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
178 {
179 	return (EOPNOTSUPP);
180 }
181 
182 static int
183 pr_sopoll_notsupp(struct socket *so, int events, struct ucred *cred,
184     struct thread *td)
185 {
186 	return (EOPNOTSUPP);
187 }
188 
189 static void
190 pr_init(struct domain *dom, struct protosw *pr)
191 {
192 
193 	KASSERT(pr->pr_attach != NULL,
194 	    ("%s: protocol doesn't have pr_attach", __func__));
195 
196 	pr->pr_domain = dom;
197 
198 #define	DEFAULT(foo, bar)	if (pr->foo == NULL) pr->foo = bar
199 	DEFAULT(pr_sosend, sosend_generic);
200 	DEFAULT(pr_soreceive, soreceive_generic);
201 	DEFAULT(pr_sopoll, sopoll_generic);
202 	DEFAULT(pr_setsbopt, sbsetopt);
203 
204 #define NOTSUPP(foo)	if (pr->foo == NULL)  pr->foo = foo ## _notsupp
205 	NOTSUPP(pr_accept);
206 	NOTSUPP(pr_aio_queue);
207 	NOTSUPP(pr_bind);
208 	NOTSUPP(pr_bindat);
209 	NOTSUPP(pr_connect);
210 	NOTSUPP(pr_connect2);
211 	NOTSUPP(pr_connectat);
212 	NOTSUPP(pr_control);
213 	NOTSUPP(pr_disconnect);
214 	NOTSUPP(pr_listen);
215 	NOTSUPP(pr_peeraddr);
216 	NOTSUPP(pr_rcvd);
217 	NOTSUPP(pr_rcvoob);
218 	NOTSUPP(pr_send);
219 	NOTSUPP(pr_shutdown);
220 	NOTSUPP(pr_sockaddr);
221 	NOTSUPP(pr_sosend);
222 	NOTSUPP(pr_soreceive);
223 	NOTSUPP(pr_sopoll);
224 	NOTSUPP(pr_ready);
225 }
226 
227 /*
228  * Add a new protocol domain to the list of supported domains
229  * Note: you cant unload it again because a socket may be using it.
230  * XXX can't fail at this time.
231  */
232 void
233 domain_add(struct domain *dp)
234 {
235 	struct protosw *pr;
236 
237 	MPASS(IS_DEFAULT_VNET(curvnet));
238 
239 	if (dp->dom_probe != NULL && (*dp->dom_probe)() != 0)
240 		return;
241 
242 	for (int i = 0; i < dp->dom_nprotosw; i++)
243 		if ((pr = dp->dom_protosw[i]) != NULL)
244 			pr_init(dp, pr);
245 
246 	mtx_lock(&dom_mtx);
247 #ifdef INVARIANTS
248 	struct domain *tmp;
249 	SLIST_FOREACH(tmp, &domains, dom_next)
250 		MPASS(tmp->dom_family != dp->dom_family);
251 #endif
252 	SLIST_INSERT_HEAD(&domains, dp, dom_next);
253 	mtx_unlock(&dom_mtx);
254 }
255 
256 void
257 domain_remove(struct domain *dp)
258 {
259 
260 	if ((dp->dom_flags & DOMF_UNLOADABLE) == 0)
261 		return;
262 
263 	mtx_lock(&dom_mtx);
264 	SLIST_REMOVE(&domains, dp, domain, dom_next);
265 	mtx_unlock(&dom_mtx);
266 }
267 
268 static void
269 domainfinalize(void *dummy)
270 {
271 
272 	mtx_lock(&dom_mtx);
273 	KASSERT(domain_init_status == 1, ("domainfinalize called too late!"));
274 	domain_init_status = 2;
275 	mtx_unlock(&dom_mtx);
276 }
277 SYSINIT(domainfin, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_FIRST, domainfinalize,
278     NULL);
279 
280 struct domain *
281 pffinddomain(int family)
282 {
283 	struct domain *dp;
284 
285 	SLIST_FOREACH(dp, &domains, dom_next)
286 		if (dp->dom_family == family)
287 			return (dp);
288 	return (NULL);
289 }
290 
291 struct protosw *
292 pffindproto(int family, int type, int proto)
293 {
294 	struct domain *dp;
295 	struct protosw *pr;
296 
297 	dp = pffinddomain(family);
298 	if (dp == NULL)
299 		return (NULL);
300 
301 	for (int i = 0; i < dp->dom_nprotosw; i++)
302 		if ((pr = dp->dom_protosw[i]) != NULL && pr->pr_type == type &&
303 		    (pr->pr_protocol == 0 || proto == 0 ||
304 		     pr->pr_protocol == proto))
305 			return (pr);
306 
307 	return (NULL);
308 }
309 
310 /*
311  * The caller must make sure that the new protocol is fully set up and ready to
312  * accept requests before it is registered.
313  */
314 int
315 protosw_register(struct domain *dp, struct protosw *npr)
316 {
317 	struct protosw **prp;
318 
319 	MPASS(dp);
320 	MPASS(npr && npr->pr_type > 0 && npr->pr_protocol > 0);
321 
322 	prp = NULL;
323 	/*
324 	 * Protect us against races when two protocol registrations for
325 	 * the same protocol happen at the same time.
326 	 */
327 	mtx_lock(&dom_mtx);
328 	for (int i = 0; i < dp->dom_nprotosw; i++) {
329 		if (dp->dom_protosw[i] == NULL) {
330 			/* Remember the first free spacer. */
331 			if (prp == NULL)
332 				prp = &dp->dom_protosw[i];
333 		} else {
334 			/*
335 			 * The new protocol must not yet exist.
336 			 * XXXAO: Check only protocol?
337 			 * XXXGL: Maybe assert that it doesn't exist?
338 			 */
339 			if ((dp->dom_protosw[i]->pr_type == npr->pr_type) &&
340 			    (dp->dom_protosw[i]->pr_protocol ==
341 			    npr->pr_protocol)) {
342 				mtx_unlock(&dom_mtx);
343 				return (EEXIST);
344 			}
345 
346 		}
347 	}
348 
349 	/* If no free spacer is found we can't add the new protocol. */
350 	if (prp == NULL) {
351 		mtx_unlock(&dom_mtx);
352 		return (ENOMEM);
353 	}
354 
355 	pr_init(dp, npr);
356 	*prp = npr;
357 	mtx_unlock(&dom_mtx);
358 
359 	return (0);
360 }
361 
362 /*
363  * The caller must make sure the protocol and its functions correctly shut down
364  * all sockets and release all locks and memory references.
365  */
366 int
367 protosw_unregister(struct protosw *pr)
368 {
369 	struct domain *dp;
370 	struct protosw **prp;
371 
372 	dp = pr->pr_domain;
373 	prp = NULL;
374 
375 	mtx_lock(&dom_mtx);
376 	/* The protocol must exist and only once. */
377 	for (int i = 0; i < dp->dom_nprotosw; i++) {
378 		if (dp->dom_protosw[i] == pr) {
379 			KASSERT(prp == NULL,
380 			    ("%s: domain %p protocol %p registered twice\n",
381 			    __func__, dp, pr));
382 			prp = &dp->dom_protosw[i];
383 		}
384 	}
385 
386 	/* Protocol does not exist.  XXXGL: assert that it does? */
387 	if (prp == NULL) {
388 		mtx_unlock(&dom_mtx);
389 		return (EPROTONOSUPPORT);
390 	}
391 
392 	/* De-orbit the protocol and make the slot available again. */
393 	*prp = NULL;
394 	mtx_unlock(&dom_mtx);
395 
396 	return (0);
397 }
398