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
32 #include <sys/param.h>
33 #include <sys/socket.h>
34 #include <sys/protosw.h>
35 #include <sys/domain.h>
36 #include <sys/eventhandler.h>
37 #include <sys/epoch.h>
38 #include <sys/mbuf.h>
39 #include <sys/kernel.h>
40 #include <sys/lock.h>
41 #include <sys/mutex.h>
42 #include <sys/rmlock.h>
43 #include <sys/socketvar.h>
44 #include <sys/systm.h>
45
46 #include <machine/atomic.h>
47
48 #include <net/vnet.h>
49
50 struct domainhead domains = SLIST_HEAD_INITIALIZER(&domains);
51 int domain_init_status = 1;
52 static struct mtx dom_mtx; /* domain list lock */
53 MTX_SYSINIT(domain, &dom_mtx, "domain list", MTX_DEF);
54
55 static int
pr_accept_notsupp(struct socket * so,struct sockaddr * sa)56 pr_accept_notsupp(struct socket *so, struct sockaddr *sa)
57 {
58 return (EOPNOTSUPP);
59 }
60
61 static int
pr_bind_notsupp(struct socket * so,struct sockaddr * nam,struct thread * td)62 pr_bind_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
63 {
64 return (EOPNOTSUPP);
65 }
66
67 static int
pr_bindat_notsupp(int fd,struct socket * so,struct sockaddr * nam,struct thread * td)68 pr_bindat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
69 struct thread *td)
70 {
71 return (EOPNOTSUPP);
72 }
73
74 static int
pr_connect_notsupp(struct socket * so,struct sockaddr * nam,struct thread * td)75 pr_connect_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
76 {
77 return (EOPNOTSUPP);
78 }
79
80 static int
pr_connectat_notsupp(int fd,struct socket * so,struct sockaddr * nam,struct thread * td)81 pr_connectat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
82 struct thread *td)
83 {
84 return (EOPNOTSUPP);
85 }
86
87 static int
pr_connect2_notsupp(struct socket * so1,struct socket * so2)88 pr_connect2_notsupp(struct socket *so1, struct socket *so2)
89 {
90 return (EOPNOTSUPP);
91 }
92
93 static int
pr_control_notsupp(struct socket * so,u_long cmd,void * data,struct ifnet * ifp,struct thread * td)94 pr_control_notsupp(struct socket *so, u_long cmd, void *data,
95 struct ifnet *ifp, struct thread *td)
96 {
97 return (EOPNOTSUPP);
98 }
99
100 static int
pr_ctloutput_notsupp(struct socket * so,struct sockopt * sopt)101 pr_ctloutput_notsupp(struct socket *so, struct sockopt *sopt)
102 {
103 return (ENOPROTOOPT);
104 }
105
106 static int
pr_disconnect_notsupp(struct socket * so)107 pr_disconnect_notsupp(struct socket *so)
108 {
109 return (EOPNOTSUPP);
110 }
111
112 int
pr_listen_notsupp(struct socket * so,int backlog,struct thread * td)113 pr_listen_notsupp(struct socket *so, int backlog, struct thread *td)
114 {
115 return (EOPNOTSUPP);
116 }
117
118 static int
pr_peeraddr_notsupp(struct socket * so,struct sockaddr * nam)119 pr_peeraddr_notsupp(struct socket *so, struct sockaddr *nam)
120 {
121 return (EOPNOTSUPP);
122 }
123
124 static int
pr_rcvd_notsupp(struct socket * so,int flags)125 pr_rcvd_notsupp(struct socket *so, int flags)
126 {
127 return (EOPNOTSUPP);
128 }
129
130 static int
pr_rcvoob_notsupp(struct socket * so,struct mbuf * m,int flags)131 pr_rcvoob_notsupp(struct socket *so, struct mbuf *m, int flags)
132 {
133 return (EOPNOTSUPP);
134 }
135
136 static int
pr_send_notsupp(struct socket * so,int flags,struct mbuf * m,struct sockaddr * addr,struct mbuf * control,struct thread * td)137 pr_send_notsupp(struct socket *so, int flags, struct mbuf *m,
138 struct sockaddr *addr, struct mbuf *control, struct thread *td)
139 {
140 if (control != NULL)
141 m_freem(control);
142 if ((flags & PRUS_NOTREADY) == 0)
143 m_freem(m);
144 return (EOPNOTSUPP);
145 }
146
147 static int
pr_sendfile_wait_notsupp(struct socket * so,off_t need,int * space)148 pr_sendfile_wait_notsupp(struct socket *so, off_t need, int *space)
149 {
150 return (EOPNOTSUPP);
151 }
152
153 static int
pr_ready_notsupp(struct socket * so,struct mbuf * m,int count)154 pr_ready_notsupp(struct socket *so, struct mbuf *m, int count)
155 {
156 return (EOPNOTSUPP);
157 }
158
159 static int
pr_shutdown_notsupp(struct socket * so,enum shutdown_how how)160 pr_shutdown_notsupp(struct socket *so, enum shutdown_how how)
161 {
162 return (EOPNOTSUPP);
163 }
164
165 static int
pr_sockaddr_notsupp(struct socket * so,struct sockaddr * nam)166 pr_sockaddr_notsupp(struct socket *so, struct sockaddr *nam)
167 {
168 return (EOPNOTSUPP);
169 }
170
171 static void
pr_init(struct domain * dom,struct protosw * pr)172 pr_init(struct domain *dom, struct protosw *pr)
173 {
174
175 KASSERT(pr->pr_attach != NULL,
176 ("%s: protocol doesn't have pr_attach", __func__));
177
178 pr->pr_domain = dom;
179
180 #define DEFAULT(foo, bar) if (pr->foo == NULL) pr->foo = bar
181 DEFAULT(pr_sosend, sosend_generic);
182 DEFAULT(pr_soreceive, soreceive_generic);
183 DEFAULT(pr_sopoll, sopoll_generic);
184 DEFAULT(pr_setsbopt, sbsetopt);
185 DEFAULT(pr_aio_queue, soaio_queue_generic);
186 DEFAULT(pr_kqfilter, sokqfilter_generic);
187
188 #define NOTSUPP(foo) if (pr->foo == NULL) pr->foo = foo ## _notsupp
189 NOTSUPP(pr_accept);
190 NOTSUPP(pr_bind);
191 NOTSUPP(pr_bindat);
192 NOTSUPP(pr_connect);
193 NOTSUPP(pr_connect2);
194 NOTSUPP(pr_connectat);
195 NOTSUPP(pr_control);
196 NOTSUPP(pr_ctloutput);
197 NOTSUPP(pr_disconnect);
198 NOTSUPP(pr_listen);
199 NOTSUPP(pr_peeraddr);
200 NOTSUPP(pr_rcvd);
201 NOTSUPP(pr_rcvoob);
202 NOTSUPP(pr_send);
203 NOTSUPP(pr_sendfile_wait);
204 NOTSUPP(pr_shutdown);
205 NOTSUPP(pr_sockaddr);
206 NOTSUPP(pr_ready);
207 }
208
209 /*
210 * Add a new protocol domain to the list of supported domains
211 * Note: you can't unload it again because a socket may be using it.
212 * XXX can't fail at this time.
213 */
214 void
domain_add(struct domain * dp)215 domain_add(struct domain *dp)
216 {
217 struct protosw *pr;
218
219 MPASS(IS_DEFAULT_VNET(curvnet));
220
221 if (dp->dom_probe != NULL && (*dp->dom_probe)() != 0)
222 return;
223
224 for (int i = 0; i < dp->dom_nprotosw; i++)
225 if ((pr = dp->dom_protosw[i]) != NULL)
226 pr_init(dp, pr);
227
228 mtx_lock(&dom_mtx);
229 #ifdef INVARIANTS
230 struct domain *tmp;
231 SLIST_FOREACH(tmp, &domains, dom_next)
232 MPASS(tmp->dom_family != dp->dom_family);
233 #endif
234 SLIST_INSERT_HEAD(&domains, dp, dom_next);
235 mtx_unlock(&dom_mtx);
236 }
237
238 void
domain_remove(struct domain * dp)239 domain_remove(struct domain *dp)
240 {
241
242 if ((dp->dom_flags & DOMF_UNLOADABLE) == 0)
243 return;
244
245 mtx_lock(&dom_mtx);
246 SLIST_REMOVE(&domains, dp, domain, dom_next);
247 mtx_unlock(&dom_mtx);
248 }
249
250 static void
domainfinalize(void * dummy)251 domainfinalize(void *dummy)
252 {
253
254 mtx_lock(&dom_mtx);
255 KASSERT(domain_init_status == 1, ("domainfinalize called too late!"));
256 domain_init_status = 2;
257 mtx_unlock(&dom_mtx);
258 }
259 SYSINIT(domainfin, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_FIRST, domainfinalize,
260 NULL);
261
262 struct domain *
pffinddomain(int family)263 pffinddomain(int family)
264 {
265 struct domain *dp;
266
267 SLIST_FOREACH(dp, &domains, dom_next)
268 if (dp->dom_family == family)
269 return (dp);
270 return (NULL);
271 }
272
273 struct protosw *
pffindproto(int family,int type,int proto)274 pffindproto(int family, int type, int proto)
275 {
276 struct domain *dp;
277 struct protosw *pr;
278
279 dp = pffinddomain(family);
280 if (dp == NULL)
281 return (NULL);
282
283 for (int i = 0; i < dp->dom_nprotosw; i++)
284 if ((pr = dp->dom_protosw[i]) != NULL && pr->pr_type == type &&
285 (pr->pr_protocol == 0 || proto == 0 ||
286 pr->pr_protocol == proto))
287 return (pr);
288
289 return (NULL);
290 }
291
292 /*
293 * The caller must make sure that the new protocol is fully set up and ready to
294 * accept requests before it is registered.
295 */
296 int
protosw_register(struct domain * dp,struct protosw * npr)297 protosw_register(struct domain *dp, struct protosw *npr)
298 {
299 struct protosw **prp;
300
301 MPASS(dp);
302 MPASS(npr && npr->pr_type > 0 && npr->pr_protocol > 0);
303
304 prp = NULL;
305 /*
306 * Protect us against races when two protocol registrations for
307 * the same protocol happen at the same time.
308 */
309 mtx_lock(&dom_mtx);
310 for (int i = 0; i < dp->dom_nprotosw; i++) {
311 if (dp->dom_protosw[i] == NULL) {
312 /* Remember the first free spacer. */
313 if (prp == NULL)
314 prp = &dp->dom_protosw[i];
315 } else {
316 /*
317 * The new protocol must not yet exist.
318 * XXXAO: Check only protocol?
319 * XXXGL: Maybe assert that it doesn't exist?
320 */
321 if ((dp->dom_protosw[i]->pr_type == npr->pr_type) &&
322 (dp->dom_protosw[i]->pr_protocol ==
323 npr->pr_protocol)) {
324 mtx_unlock(&dom_mtx);
325 return (EEXIST);
326 }
327
328 }
329 }
330
331 /* If no free spacer is found we can't add the new protocol. */
332 if (prp == NULL) {
333 mtx_unlock(&dom_mtx);
334 return (ENOMEM);
335 }
336
337 pr_init(dp, npr);
338 *prp = npr;
339 mtx_unlock(&dom_mtx);
340
341 return (0);
342 }
343
344 /*
345 * The caller must make sure the protocol and its functions correctly shut down
346 * all sockets and release all locks and memory references.
347 */
348 int
protosw_unregister(struct protosw * pr)349 protosw_unregister(struct protosw *pr)
350 {
351 struct domain *dp;
352 struct protosw **prp;
353
354 dp = pr->pr_domain;
355 prp = NULL;
356
357 mtx_lock(&dom_mtx);
358 /* The protocol must exist and only once. */
359 for (int i = 0; i < dp->dom_nprotosw; i++) {
360 if (dp->dom_protosw[i] == pr) {
361 KASSERT(prp == NULL,
362 ("%s: domain %p protocol %p registered twice\n",
363 __func__, dp, pr));
364 prp = &dp->dom_protosw[i];
365 }
366 }
367
368 /* Protocol does not exist. XXXGL: assert that it does? */
369 if (prp == NULL) {
370 mtx_unlock(&dom_mtx);
371 return (EPROTONOSUPPORT);
372 }
373
374 /* De-orbit the protocol and make the slot available again. */
375 *prp = NULL;
376 mtx_unlock(&dom_mtx);
377
378 return (0);
379 }
380