1 /* $NetBSD: if_loop.c,v 1.89 2016/06/22 10:44:32 knakahara Exp $ */
2
3 /*
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * 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 project 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 PROJECT 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 PROJECT 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 /*
33 * Copyright (c) 1982, 1986, 1993
34 * The Regents of the University of California. All rights reserved.
35 *
36 * Redistribution and use in source and binary forms, with or without
37 * modification, are permitted provided that the following conditions
38 * are met:
39 * 1. Redistributions of source code must retain the above copyright
40 * notice, this list of conditions and the following disclaimer.
41 * 2. Redistributions in binary form must reproduce the above copyright
42 * notice, this list of conditions and the following disclaimer in the
43 * documentation and/or other materials provided with the distribution.
44 * 3. Neither the name of the University nor the names of its contributors
45 * may be used to endorse or promote products derived from this software
46 * without specific prior written permission.
47 *
48 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
49 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
52 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
53 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
54 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
55 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
56 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
57 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
58 * SUCH DAMAGE.
59 *
60 * @(#)if_loop.c 8.2 (Berkeley) 1/9/95
61 */
62
63 /*
64 * Loopback interface driver for protocol testing and timing.
65 */
66
67 #include <sys/cdefs.h>
68 __KERNEL_RCSID(0, "$NetBSD: if_loop.c,v 1.89 2016/06/22 10:44:32 knakahara Exp $");
69
70 #ifdef _KERNEL_OPT
71 #include "opt_inet.h"
72 #include "opt_atalk.h"
73 #include "opt_mbuftrace.h"
74 #include "opt_mpls.h"
75 #include "opt_net_mpsafe.h"
76 #endif
77
78 #include <sys/param.h>
79 #include <sys/systm.h>
80 #include <sys/kernel.h>
81 #include <sys/mbuf.h>
82 #include <sys/socket.h>
83 #include <sys/errno.h>
84 #include <sys/ioctl.h>
85 #include <sys/time.h>
86
87 #include <sys/cpu.h>
88
89 #include <net/if.h>
90 #include <net/if_types.h>
91 #include <net/netisr.h>
92 #include <net/route.h>
93
94 #ifdef INET
95 #include <netinet/in.h>
96 #include <netinet/in_systm.h>
97 #include <netinet/in_var.h>
98 #include <netinet/in_offload.h>
99 #include <netinet/ip.h>
100 #endif
101
102 #ifdef INET6
103 #ifndef INET
104 #include <netinet/in.h>
105 #endif
106 #include <netinet6/in6_var.h>
107 #include <netinet6/in6_offload.h>
108 #include <netinet/ip6.h>
109 #endif
110
111 #ifdef MPLS
112 #include <netmpls/mpls.h>
113 #include <netmpls/mpls_var.h>
114 #endif
115
116 #ifdef NETATALK
117 #include <netatalk/at.h>
118 #include <netatalk/at_var.h>
119 #endif
120
121 #include <net/bpf.h>
122
123 #if defined(LARGE_LOMTU)
124 #define LOMTU (131072 + MHLEN + MLEN)
125 #define LOMTU_MAX LOMTU
126 #else
127 #define LOMTU (32768 + MHLEN + MLEN)
128 #define LOMTU_MAX (65536 + MHLEN + MLEN)
129 #endif
130
131 #ifdef ALTQ
132 static void lostart(struct ifnet *);
133 #endif
134
135 static int loop_clone_create(struct if_clone *, int);
136 static int loop_clone_destroy(struct ifnet *);
137
138 static struct if_clone loop_cloner =
139 IF_CLONE_INITIALIZER("lo", loop_clone_create, loop_clone_destroy);
140
141 void
loopattach(int n)142 loopattach(int n)
143 {
144
145 (void)loop_clone_create(&loop_cloner, 0); /* lo0 always exists */
146 if_clone_attach(&loop_cloner);
147 }
148
149 static int
loop_clone_create(struct if_clone * ifc,int unit)150 loop_clone_create(struct if_clone *ifc, int unit)
151 {
152 struct ifnet *ifp;
153 int tmp = IFF_LOOPBACK | IFF_MULTICAST | IFF_RUNNING;
154
155 ifp = if_alloc(IFT_LOOP);
156
157 if_initname(ifp, ifc->ifc_name, unit);
158
159 ifp->if_mtu = LOMTU;
160 ifp->if_flags = tmp;
161 ifp->if_extflags = IFEF_OUTPUT_MPSAFE;
162 ifp->if_ioctl = loioctl;
163 ifp->if_output = looutput;
164 #ifdef ALTQ
165 ifp->if_start = lostart;
166 #endif
167 ifp->if_type = IFT_LOOP;
168 ifp->if_hdrlen = 0;
169 ifp->if_addrlen = 0;
170 ifp->if_dlt = DLT_NULL;
171 IFQ_SET_READY(&ifp->if_snd);
172 if (unit == 0)
173 lo0ifp = ifp;
174 if_attach(ifp);
175 if_alloc_sadl(ifp);
176 bpf_attach(ifp, DLT_NULL, sizeof(u_int));
177 #ifdef MBUFTRACE
178 ifp->if_mowner = malloc(sizeof(struct mowner), M_DEVBUF,
179 M_WAITOK | M_ZERO);
180 strlcpy(ifp->if_mowner->mo_name, ifp->if_xname,
181 sizeof(ifp->if_mowner->mo_name));
182 MOWNER_ATTACH(ifp->if_mowner);
183 #endif
184
185 return (0);
186 }
187
188 static int
loop_clone_destroy(struct ifnet * ifp)189 loop_clone_destroy(struct ifnet *ifp)
190 {
191
192 if (ifp == lo0ifp)
193 return (EPERM);
194
195 #ifdef MBUFTRACE
196 MOWNER_DETACH(ifp->if_mowner);
197 free(ifp->if_mowner, M_DEVBUF);
198 #endif
199
200 bpf_detach(ifp);
201 if_detach(ifp);
202
203 if_free(ifp);
204
205 return (0);
206 }
207
208 int
looutput(struct ifnet * ifp,struct mbuf * m,const struct sockaddr * dst,const struct rtentry * rt)209 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
210 const struct rtentry *rt)
211 {
212 pktqueue_t *pktq = NULL;
213 struct ifqueue *ifq = NULL;
214 int s, isr = -1;
215 int csum_flags;
216 int error = 0;
217 size_t pktlen;
218
219 MCLAIM(m, ifp->if_mowner);
220
221 KERNEL_LOCK(1, NULL);
222
223 if ((m->m_flags & M_PKTHDR) == 0)
224 panic("looutput: no header mbuf");
225 if (ifp->if_flags & IFF_LOOPBACK)
226 bpf_mtap_af(ifp, dst->sa_family, m);
227 m_set_rcvif(m, ifp);
228
229 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
230 m_freem(m);
231 error = (rt->rt_flags & RTF_BLACKHOLE ? 0 :
232 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
233 goto out;
234 }
235
236 pktlen = m->m_pkthdr.len;
237 ifp->if_opackets++;
238 ifp->if_obytes += pktlen;
239
240 #ifdef ALTQ
241 /*
242 * ALTQ on the loopback interface is just for debugging. It's
243 * used only for loopback interfaces, not for a simplex interface.
244 */
245 if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
246 ifp->if_start == lostart) {
247 /*
248 * If the queueing discipline needs packet classification,
249 * do it before prepending the link headers.
250 */
251 IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family);
252
253 M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
254 if (m == NULL) {
255 error = ENOBUFS;
256 goto out;
257 }
258 *(mtod(m, uint32_t *)) = dst->sa_family;
259
260 error = if_transmit_lock(ifp, m);
261 goto out;
262 }
263 #endif /* ALTQ */
264
265 m_tag_delete_nonpersistent(m);
266
267 #ifdef MPLS
268 if (rt != NULL && rt_gettag(rt) != NULL &&
269 rt_gettag(rt)->sa_family == AF_MPLS &&
270 (m->m_flags & (M_MCAST | M_BCAST)) == 0) {
271 union mpls_shim msh;
272 msh.s_addr = MPLS_GETSADDR(rt);
273 if (msh.shim.label != MPLS_LABEL_IMPLNULL) {
274 ifq = &mplsintrq;
275 isr = NETISR_MPLS;
276 }
277 }
278 if (isr != NETISR_MPLS)
279 #endif
280 switch (dst->sa_family) {
281
282 #ifdef INET
283 case AF_INET:
284 csum_flags = m->m_pkthdr.csum_flags;
285 KASSERT((csum_flags & ~(M_CSUM_IPv4|M_CSUM_UDPv4)) == 0);
286 if (csum_flags != 0 && IN_LOOPBACK_NEED_CHECKSUM(csum_flags)) {
287 ip_undefer_csum(m, 0, csum_flags);
288 }
289 m->m_pkthdr.csum_flags = 0;
290 pktq = ip_pktq;
291 break;
292 #endif
293 #ifdef INET6
294 case AF_INET6:
295 csum_flags = m->m_pkthdr.csum_flags;
296 KASSERT((csum_flags & ~M_CSUM_UDPv6) == 0);
297 if (csum_flags != 0 &&
298 IN6_LOOPBACK_NEED_CHECKSUM(csum_flags)) {
299 ip6_undefer_csum(m, 0, csum_flags);
300 }
301 m->m_pkthdr.csum_flags = 0;
302 m->m_flags |= M_LOOP;
303 pktq = ip6_pktq;
304 break;
305 #endif
306 #ifdef NETATALK
307 case AF_APPLETALK:
308 ifq = &atintrq2;
309 isr = NETISR_ATALK;
310 break;
311 #endif
312 default:
313 printf("%s: can't handle af%d\n", ifp->if_xname,
314 dst->sa_family);
315 m_freem(m);
316 error = EAFNOSUPPORT;
317 goto out;
318 }
319
320 s = splnet();
321 if (__predict_true(pktq)) {
322 error = 0;
323
324 if (__predict_true(pktq_enqueue(pktq, m, 0))) {
325 ifp->if_ipackets++;
326 ifp->if_ibytes += pktlen;
327 } else {
328 m_freem(m);
329 error = ENOBUFS;
330 }
331 splx(s);
332 goto out;
333 }
334 if (IF_QFULL(ifq)) {
335 IF_DROP(ifq);
336 m_freem(m);
337 splx(s);
338 error = ENOBUFS;
339 goto out;
340 }
341 IF_ENQUEUE(ifq, m);
342 schednetisr(isr);
343 ifp->if_ipackets++;
344 ifp->if_ibytes += m->m_pkthdr.len;
345 splx(s);
346 out:
347 KERNEL_UNLOCK_ONE(NULL);
348 return error;
349 }
350
351 #ifdef ALTQ
352 static void
lostart(struct ifnet * ifp)353 lostart(struct ifnet *ifp)
354 {
355 for (;;) {
356 pktqueue_t *pktq = NULL;
357 struct ifqueue *ifq = NULL;
358 struct mbuf *m;
359 size_t pktlen;
360 uint32_t af;
361 int s, isr = 0;
362
363 IFQ_DEQUEUE(&ifp->if_snd, m);
364 if (m == NULL)
365 return;
366
367 af = *(mtod(m, uint32_t *));
368 m_adj(m, sizeof(uint32_t));
369
370 switch (af) {
371 #ifdef INET
372 case AF_INET:
373 pktq = ip_pktq;
374 break;
375 #endif
376 #ifdef INET6
377 case AF_INET6:
378 m->m_flags |= M_LOOP;
379 pktq = ip6_pktq;
380 break;
381 #endif
382 #ifdef NETATALK
383 case AF_APPLETALK:
384 ifq = &atintrq2;
385 isr = NETISR_ATALK;
386 break;
387 #endif
388 default:
389 printf("%s: can't handle af%d\n", ifp->if_xname, af);
390 m_freem(m);
391 return;
392 }
393 pktlen = m->m_pkthdr.len;
394
395 s = splnet();
396 if (__predict_true(pktq)) {
397 if (__predict_false(pktq_enqueue(pktq, m, 0))) {
398 m_freem(m);
399 splx(s);
400 return;
401 }
402 ifp->if_ipackets++;
403 ifp->if_ibytes += pktlen;
404 splx(s);
405 continue;
406 }
407 if (IF_QFULL(ifq)) {
408 IF_DROP(ifq);
409 splx(s);
410 m_freem(m);
411 return;
412 }
413 IF_ENQUEUE(ifq, m);
414 schednetisr(isr);
415 ifp->if_ipackets++;
416 ifp->if_ibytes += pktlen;
417 splx(s);
418 }
419 }
420 #endif /* ALTQ */
421
422 /* ARGSUSED */
423 void
lortrequest(int cmd,struct rtentry * rt,const struct rt_addrinfo * info)424 lortrequest(int cmd, struct rtentry *rt,
425 const struct rt_addrinfo *info)
426 {
427
428 if (rt)
429 rt->rt_rmx.rmx_mtu = lo0ifp->if_mtu;
430 }
431
432 /*
433 * Process an ioctl request.
434 */
435 /* ARGSUSED */
436 int
loioctl(struct ifnet * ifp,u_long cmd,void * data)437 loioctl(struct ifnet *ifp, u_long cmd, void *data)
438 {
439 struct ifaddr *ifa;
440 struct ifreq *ifr = data;
441 int error = 0;
442
443 switch (cmd) {
444
445 case SIOCINITIFADDR:
446 ifp->if_flags |= IFF_UP;
447 ifa = (struct ifaddr *)data;
448 if (ifa != NULL)
449 ifa->ifa_rtrequest = lortrequest;
450 /*
451 * Everything else is done at a higher level.
452 */
453 break;
454
455 case SIOCSIFMTU:
456 if ((unsigned)ifr->ifr_mtu > LOMTU_MAX)
457 error = EINVAL;
458 else if ((error = ifioctl_common(ifp, cmd, data)) == ENETRESET){
459 error = 0;
460 }
461 break;
462
463 case SIOCADDMULTI:
464 case SIOCDELMULTI:
465 if (ifr == NULL) {
466 error = EAFNOSUPPORT; /* XXX */
467 break;
468 }
469 switch (ifreq_getaddr(cmd, ifr)->sa_family) {
470
471 #ifdef INET
472 case AF_INET:
473 break;
474 #endif
475 #ifdef INET6
476 case AF_INET6:
477 break;
478 #endif
479
480 default:
481 error = EAFNOSUPPORT;
482 break;
483 }
484 break;
485
486 default:
487 error = ifioctl_common(ifp, cmd, data);
488 }
489 return (error);
490 }
491