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_aio_queue_notsupp(struct socket * so,struct kaiocb * job)62 pr_aio_queue_notsupp(struct socket *so, struct kaiocb *job)
63 {
64 return (EOPNOTSUPP);
65 }
66
67 static int
pr_bind_notsupp(struct socket * so,struct sockaddr * nam,struct thread * td)68 pr_bind_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
69 {
70 return (EOPNOTSUPP);
71 }
72
73 static int
pr_bindat_notsupp(int fd,struct socket * so,struct sockaddr * nam,struct thread * td)74 pr_bindat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
75 struct thread *td)
76 {
77 return (EOPNOTSUPP);
78 }
79
80 static int
pr_connect_notsupp(struct socket * so,struct sockaddr * nam,struct thread * td)81 pr_connect_notsupp(struct socket *so, struct sockaddr *nam, struct thread *td)
82 {
83 return (EOPNOTSUPP);
84 }
85
86 static int
pr_connectat_notsupp(int fd,struct socket * so,struct sockaddr * nam,struct thread * td)87 pr_connectat_notsupp(int fd, struct socket *so, struct sockaddr *nam,
88 struct thread *td)
89 {
90 return (EOPNOTSUPP);
91 }
92
93 static int
pr_connect2_notsupp(struct socket * so1,struct socket * so2)94 pr_connect2_notsupp(struct socket *so1, struct socket *so2)
95 {
96 return (EOPNOTSUPP);
97 }
98
99 static int
pr_control_notsupp(struct socket * so,u_long cmd,void * data,struct ifnet * ifp,struct thread * td)100 pr_control_notsupp(struct socket *so, u_long cmd, void *data,
101 struct ifnet *ifp, struct thread *td)
102 {
103 return (EOPNOTSUPP);
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_ready_notsupp(struct socket * so,struct mbuf * m,int count)148 pr_ready_notsupp(struct socket *so, struct mbuf *m, int count)
149 {
150 return (EOPNOTSUPP);
151 }
152
153 static int
pr_shutdown_notsupp(struct socket * so,enum shutdown_how how)154 pr_shutdown_notsupp(struct socket *so, enum shutdown_how how)
155 {
156 return (EOPNOTSUPP);
157 }
158
159 static int
pr_sockaddr_notsupp(struct socket * so,struct sockaddr * nam)160 pr_sockaddr_notsupp(struct socket *so, struct sockaddr *nam)
161 {
162 return (EOPNOTSUPP);
163 }
164
165 static int
pr_sosend_notsupp(struct socket * so,struct sockaddr * addr,struct uio * uio,struct mbuf * top,struct mbuf * control,int flags,struct thread * td)166 pr_sosend_notsupp(struct socket *so, struct sockaddr *addr, struct uio *uio,
167 struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
168 {
169 return (EOPNOTSUPP);
170 }
171
172 static int
pr_soreceive_notsupp(struct socket * so,struct sockaddr ** paddr,struct uio * uio,struct mbuf ** mp0,struct mbuf ** controlp,int * flagsp)173 pr_soreceive_notsupp(struct socket *so, struct sockaddr **paddr,
174 struct uio *uio, struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
175 {
176 return (EOPNOTSUPP);
177 }
178
179 static int
pr_sopoll_notsupp(struct socket * so,int events,struct ucred * cred,struct thread * td)180 pr_sopoll_notsupp(struct socket *so, int events, struct ucred *cred,
181 struct thread *td)
182 {
183 return (EOPNOTSUPP);
184 }
185
186 static void
pr_init(struct domain * dom,struct protosw * pr)187 pr_init(struct domain *dom, struct protosw *pr)
188 {
189
190 KASSERT(pr->pr_attach != NULL,
191 ("%s: protocol doesn't have pr_attach", __func__));
192
193 pr->pr_domain = dom;
194
195 #define DEFAULT(foo, bar) if (pr->foo == NULL) pr->foo = bar
196 DEFAULT(pr_sosend, sosend_generic);
197 DEFAULT(pr_soreceive, soreceive_generic);
198 DEFAULT(pr_sopoll, sopoll_generic);
199 DEFAULT(pr_setsbopt, sbsetopt);
200
201 #define NOTSUPP(foo) if (pr->foo == NULL) pr->foo = foo ## _notsupp
202 NOTSUPP(pr_accept);
203 NOTSUPP(pr_aio_queue);
204 NOTSUPP(pr_bind);
205 NOTSUPP(pr_bindat);
206 NOTSUPP(pr_connect);
207 NOTSUPP(pr_connect2);
208 NOTSUPP(pr_connectat);
209 NOTSUPP(pr_control);
210 NOTSUPP(pr_disconnect);
211 NOTSUPP(pr_listen);
212 NOTSUPP(pr_peeraddr);
213 NOTSUPP(pr_rcvd);
214 NOTSUPP(pr_rcvoob);
215 NOTSUPP(pr_send);
216 NOTSUPP(pr_shutdown);
217 NOTSUPP(pr_sockaddr);
218 NOTSUPP(pr_sosend);
219 NOTSUPP(pr_soreceive);
220 NOTSUPP(pr_sopoll);
221 NOTSUPP(pr_ready);
222 }
223
224 /*
225 * Add a new protocol domain to the list of supported domains
226 * Note: you can't unload it again because a socket may be using it.
227 * XXX can't fail at this time.
228 */
229 void
domain_add(struct domain * dp)230 domain_add(struct domain *dp)
231 {
232 struct protosw *pr;
233
234 MPASS(IS_DEFAULT_VNET(curvnet));
235
236 if (dp->dom_probe != NULL && (*dp->dom_probe)() != 0)
237 return;
238
239 for (int i = 0; i < dp->dom_nprotosw; i++)
240 if ((pr = dp->dom_protosw[i]) != NULL)
241 pr_init(dp, pr);
242
243 mtx_lock(&dom_mtx);
244 #ifdef INVARIANTS
245 struct domain *tmp;
246 SLIST_FOREACH(tmp, &domains, dom_next)
247 MPASS(tmp->dom_family != dp->dom_family);
248 #endif
249 SLIST_INSERT_HEAD(&domains, dp, dom_next);
250 mtx_unlock(&dom_mtx);
251 }
252
253 void
domain_remove(struct domain * dp)254 domain_remove(struct domain *dp)
255 {
256
257 if ((dp->dom_flags & DOMF_UNLOADABLE) == 0)
258 return;
259
260 mtx_lock(&dom_mtx);
261 SLIST_REMOVE(&domains, dp, domain, dom_next);
262 mtx_unlock(&dom_mtx);
263 }
264
265 static void
domainfinalize(void * dummy)266 domainfinalize(void *dummy)
267 {
268
269 mtx_lock(&dom_mtx);
270 KASSERT(domain_init_status == 1, ("domainfinalize called too late!"));
271 domain_init_status = 2;
272 mtx_unlock(&dom_mtx);
273 }
274 SYSINIT(domainfin, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_FIRST, domainfinalize,
275 NULL);
276
277 struct domain *
pffinddomain(int family)278 pffinddomain(int family)
279 {
280 struct domain *dp;
281
282 SLIST_FOREACH(dp, &domains, dom_next)
283 if (dp->dom_family == family)
284 return (dp);
285 return (NULL);
286 }
287
288 struct protosw *
pffindproto(int family,int type,int proto)289 pffindproto(int family, int type, int proto)
290 {
291 struct domain *dp;
292 struct protosw *pr;
293
294 dp = pffinddomain(family);
295 if (dp == NULL)
296 return (NULL);
297
298 for (int i = 0; i < dp->dom_nprotosw; i++)
299 if ((pr = dp->dom_protosw[i]) != NULL && pr->pr_type == type &&
300 (pr->pr_protocol == 0 || proto == 0 ||
301 pr->pr_protocol == proto))
302 return (pr);
303
304 return (NULL);
305 }
306
307 /*
308 * The caller must make sure that the new protocol is fully set up and ready to
309 * accept requests before it is registered.
310 */
311 int
protosw_register(struct domain * dp,struct protosw * npr)312 protosw_register(struct domain *dp, struct protosw *npr)
313 {
314 struct protosw **prp;
315
316 MPASS(dp);
317 MPASS(npr && npr->pr_type > 0 && npr->pr_protocol > 0);
318
319 prp = NULL;
320 /*
321 * Protect us against races when two protocol registrations for
322 * the same protocol happen at the same time.
323 */
324 mtx_lock(&dom_mtx);
325 for (int i = 0; i < dp->dom_nprotosw; i++) {
326 if (dp->dom_protosw[i] == NULL) {
327 /* Remember the first free spacer. */
328 if (prp == NULL)
329 prp = &dp->dom_protosw[i];
330 } else {
331 /*
332 * The new protocol must not yet exist.
333 * XXXAO: Check only protocol?
334 * XXXGL: Maybe assert that it doesn't exist?
335 */
336 if ((dp->dom_protosw[i]->pr_type == npr->pr_type) &&
337 (dp->dom_protosw[i]->pr_protocol ==
338 npr->pr_protocol)) {
339 mtx_unlock(&dom_mtx);
340 return (EEXIST);
341 }
342
343 }
344 }
345
346 /* If no free spacer is found we can't add the new protocol. */
347 if (prp == NULL) {
348 mtx_unlock(&dom_mtx);
349 return (ENOMEM);
350 }
351
352 pr_init(dp, npr);
353 *prp = npr;
354 mtx_unlock(&dom_mtx);
355
356 return (0);
357 }
358
359 /*
360 * The caller must make sure the protocol and its functions correctly shut down
361 * all sockets and release all locks and memory references.
362 */
363 int
protosw_unregister(struct protosw * pr)364 protosw_unregister(struct protosw *pr)
365 {
366 struct domain *dp;
367 struct protosw **prp;
368
369 dp = pr->pr_domain;
370 prp = NULL;
371
372 mtx_lock(&dom_mtx);
373 /* The protocol must exist and only once. */
374 for (int i = 0; i < dp->dom_nprotosw; i++) {
375 if (dp->dom_protosw[i] == pr) {
376 KASSERT(prp == NULL,
377 ("%s: domain %p protocol %p registered twice\n",
378 __func__, dp, pr));
379 prp = &dp->dom_protosw[i];
380 }
381 }
382
383 /* Protocol does not exist. XXXGL: assert that it does? */
384 if (prp == NULL) {
385 mtx_unlock(&dom_mtx);
386 return (EPROTONOSUPPORT);
387 }
388
389 /* De-orbit the protocol and make the slot available again. */
390 *prp = NULL;
391 mtx_unlock(&dom_mtx);
392
393 return (0);
394 }
395