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_disconnect_notsupp(struct socket * so)101 pr_disconnect_notsupp(struct socket *so)
102 {
103 return (EOPNOTSUPP);
104 }
105
106 int
pr_listen_notsupp(struct socket * so,int backlog,struct thread * td)107 pr_listen_notsupp(struct socket *so, int backlog, struct thread *td)
108 {
109 return (EOPNOTSUPP);
110 }
111
112 static int
pr_peeraddr_notsupp(struct socket * so,struct sockaddr * nam)113 pr_peeraddr_notsupp(struct socket *so, struct sockaddr *nam)
114 {
115 return (EOPNOTSUPP);
116 }
117
118 static int
pr_rcvd_notsupp(struct socket * so,int flags)119 pr_rcvd_notsupp(struct socket *so, int flags)
120 {
121 return (EOPNOTSUPP);
122 }
123
124 static int
pr_rcvoob_notsupp(struct socket * so,struct mbuf * m,int flags)125 pr_rcvoob_notsupp(struct socket *so, struct mbuf *m, int flags)
126 {
127 return (EOPNOTSUPP);
128 }
129
130 static int
pr_send_notsupp(struct socket * so,int flags,struct mbuf * m,struct sockaddr * addr,struct mbuf * control,struct thread * td)131 pr_send_notsupp(struct socket *so, int flags, struct mbuf *m,
132 struct sockaddr *addr, struct mbuf *control, struct thread *td)
133 {
134 if (control != NULL)
135 m_freem(control);
136 if ((flags & PRUS_NOTREADY) == 0)
137 m_freem(m);
138 return (EOPNOTSUPP);
139 }
140
141 static int
pr_ready_notsupp(struct socket * so,struct mbuf * m,int count)142 pr_ready_notsupp(struct socket *so, struct mbuf *m, int count)
143 {
144 return (EOPNOTSUPP);
145 }
146
147 static int
pr_shutdown_notsupp(struct socket * so,enum shutdown_how how)148 pr_shutdown_notsupp(struct socket *so, enum shutdown_how how)
149 {
150 return (EOPNOTSUPP);
151 }
152
153 static int
pr_sockaddr_notsupp(struct socket * so,struct sockaddr * nam)154 pr_sockaddr_notsupp(struct socket *so, struct sockaddr *nam)
155 {
156 return (EOPNOTSUPP);
157 }
158
159 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)160 pr_sosend_notsupp(struct socket *so, struct sockaddr *addr, struct uio *uio,
161 struct mbuf *top, struct mbuf *control, int flags, struct thread *td)
162 {
163 return (EOPNOTSUPP);
164 }
165
166 static int
pr_soreceive_notsupp(struct socket * so,struct sockaddr ** paddr,struct uio * uio,struct mbuf ** mp0,struct mbuf ** controlp,int * flagsp)167 pr_soreceive_notsupp(struct socket *so, struct sockaddr **paddr,
168 struct uio *uio, struct mbuf **mp0, struct mbuf **controlp, int *flagsp)
169 {
170 return (EOPNOTSUPP);
171 }
172
173 static void
pr_init(struct domain * dom,struct protosw * pr)174 pr_init(struct domain *dom, struct protosw *pr)
175 {
176
177 KASSERT(pr->pr_attach != NULL,
178 ("%s: protocol doesn't have pr_attach", __func__));
179
180 pr->pr_domain = dom;
181
182 #define DEFAULT(foo, bar) if (pr->foo == NULL) pr->foo = bar
183 DEFAULT(pr_sosend, sosend_generic);
184 DEFAULT(pr_soreceive, soreceive_generic);
185 DEFAULT(pr_sopoll, sopoll_generic);
186 DEFAULT(pr_setsbopt, sbsetopt);
187 DEFAULT(pr_aio_queue, soaio_queue_generic);
188
189 #define NOTSUPP(foo) if (pr->foo == NULL) pr->foo = foo ## _notsupp
190 NOTSUPP(pr_accept);
191 NOTSUPP(pr_bind);
192 NOTSUPP(pr_bindat);
193 NOTSUPP(pr_connect);
194 NOTSUPP(pr_connect2);
195 NOTSUPP(pr_connectat);
196 NOTSUPP(pr_control);
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_shutdown);
204 NOTSUPP(pr_sockaddr);
205 NOTSUPP(pr_sosend);
206 NOTSUPP(pr_soreceive);
207 NOTSUPP(pr_ready);
208 }
209
210 /*
211 * Add a new protocol domain to the list of supported domains
212 * Note: you can't unload it again because a socket may be using it.
213 * XXX can't fail at this time.
214 */
215 void
domain_add(struct domain * dp)216 domain_add(struct domain *dp)
217 {
218 struct protosw *pr;
219
220 MPASS(IS_DEFAULT_VNET(curvnet));
221
222 if (dp->dom_probe != NULL && (*dp->dom_probe)() != 0)
223 return;
224
225 for (int i = 0; i < dp->dom_nprotosw; i++)
226 if ((pr = dp->dom_protosw[i]) != NULL)
227 pr_init(dp, pr);
228
229 mtx_lock(&dom_mtx);
230 #ifdef INVARIANTS
231 struct domain *tmp;
232 SLIST_FOREACH(tmp, &domains, dom_next)
233 MPASS(tmp->dom_family != dp->dom_family);
234 #endif
235 SLIST_INSERT_HEAD(&domains, dp, dom_next);
236 mtx_unlock(&dom_mtx);
237 }
238
239 void
domain_remove(struct domain * dp)240 domain_remove(struct domain *dp)
241 {
242
243 if ((dp->dom_flags & DOMF_UNLOADABLE) == 0)
244 return;
245
246 mtx_lock(&dom_mtx);
247 SLIST_REMOVE(&domains, dp, domain, dom_next);
248 mtx_unlock(&dom_mtx);
249 }
250
251 static void
domainfinalize(void * dummy)252 domainfinalize(void *dummy)
253 {
254
255 mtx_lock(&dom_mtx);
256 KASSERT(domain_init_status == 1, ("domainfinalize called too late!"));
257 domain_init_status = 2;
258 mtx_unlock(&dom_mtx);
259 }
260 SYSINIT(domainfin, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_FIRST, domainfinalize,
261 NULL);
262
263 struct domain *
pffinddomain(int family)264 pffinddomain(int family)
265 {
266 struct domain *dp;
267
268 SLIST_FOREACH(dp, &domains, dom_next)
269 if (dp->dom_family == family)
270 return (dp);
271 return (NULL);
272 }
273
274 struct protosw *
pffindproto(int family,int type,int proto)275 pffindproto(int family, int type, int proto)
276 {
277 struct domain *dp;
278 struct protosw *pr;
279
280 dp = pffinddomain(family);
281 if (dp == NULL)
282 return (NULL);
283
284 for (int i = 0; i < dp->dom_nprotosw; i++)
285 if ((pr = dp->dom_protosw[i]) != NULL && pr->pr_type == type &&
286 (pr->pr_protocol == 0 || proto == 0 ||
287 pr->pr_protocol == proto))
288 return (pr);
289
290 return (NULL);
291 }
292
293 /*
294 * The caller must make sure that the new protocol is fully set up and ready to
295 * accept requests before it is registered.
296 */
297 int
protosw_register(struct domain * dp,struct protosw * npr)298 protosw_register(struct domain *dp, struct protosw *npr)
299 {
300 struct protosw **prp;
301
302 MPASS(dp);
303 MPASS(npr && npr->pr_type > 0 && npr->pr_protocol > 0);
304
305 prp = NULL;
306 /*
307 * Protect us against races when two protocol registrations for
308 * the same protocol happen at the same time.
309 */
310 mtx_lock(&dom_mtx);
311 for (int i = 0; i < dp->dom_nprotosw; i++) {
312 if (dp->dom_protosw[i] == NULL) {
313 /* Remember the first free spacer. */
314 if (prp == NULL)
315 prp = &dp->dom_protosw[i];
316 } else {
317 /*
318 * The new protocol must not yet exist.
319 * XXXAO: Check only protocol?
320 * XXXGL: Maybe assert that it doesn't exist?
321 */
322 if ((dp->dom_protosw[i]->pr_type == npr->pr_type) &&
323 (dp->dom_protosw[i]->pr_protocol ==
324 npr->pr_protocol)) {
325 mtx_unlock(&dom_mtx);
326 return (EEXIST);
327 }
328
329 }
330 }
331
332 /* If no free spacer is found we can't add the new protocol. */
333 if (prp == NULL) {
334 mtx_unlock(&dom_mtx);
335 return (ENOMEM);
336 }
337
338 pr_init(dp, npr);
339 *prp = npr;
340 mtx_unlock(&dom_mtx);
341
342 return (0);
343 }
344
345 /*
346 * The caller must make sure the protocol and its functions correctly shut down
347 * all sockets and release all locks and memory references.
348 */
349 int
protosw_unregister(struct protosw * pr)350 protosw_unregister(struct protosw *pr)
351 {
352 struct domain *dp;
353 struct protosw **prp;
354
355 dp = pr->pr_domain;
356 prp = NULL;
357
358 mtx_lock(&dom_mtx);
359 /* The protocol must exist and only once. */
360 for (int i = 0; i < dp->dom_nprotosw; i++) {
361 if (dp->dom_protosw[i] == pr) {
362 KASSERT(prp == NULL,
363 ("%s: domain %p protocol %p registered twice\n",
364 __func__, dp, pr));
365 prp = &dp->dom_protosw[i];
366 }
367 }
368
369 /* Protocol does not exist. XXXGL: assert that it does? */
370 if (prp == NULL) {
371 mtx_unlock(&dom_mtx);
372 return (EPROTONOSUPPORT);
373 }
374
375 /* De-orbit the protocol and make the slot available again. */
376 *prp = NULL;
377 mtx_unlock(&dom_mtx);
378
379 return (0);
380 }
381