FreeBSD/Linux Kernel Cross Reference
sys/net/if_loop.c
1 /*-
2 * Copyright (c) 1982, 1986, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * @(#)if_loop.c 8.2 (Berkeley) 1/9/95
30 * $FreeBSD$
31 */
32
33 /*
34 * Loopback interface driver for protocol testing and timing.
35 */
36
37 #include "opt_atalk.h"
38 #include "opt_inet.h"
39 #include "opt_inet6.h"
40 #include "opt_ipx.h"
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/kernel.h>
45 #include <sys/mbuf.h>
46 #include <sys/module.h>
47 #include <machine/bus.h>
48 #include <sys/rman.h>
49 #include <sys/socket.h>
50 #include <sys/sockio.h>
51 #include <sys/sysctl.h>
52
53 #include <net/if.h>
54 #include <net/if_clone.h>
55 #include <net/if_types.h>
56 #include <net/netisr.h>
57 #include <net/route.h>
58 #include <net/bpf.h>
59 #include <net/vnet.h>
60
61 #ifdef INET
62 #include <netinet/in.h>
63 #include <netinet/in_var.h>
64 #endif
65
66 #ifdef IPX
67 #include <netipx/ipx.h>
68 #include <netipx/ipx_if.h>
69 #endif
70
71 #ifdef INET6
72 #ifndef INET
73 #include <netinet/in.h>
74 #endif
75 #include <netinet6/in6_var.h>
76 #include <netinet/ip6.h>
77 #endif
78
79 #ifdef NETATALK
80 #include <netatalk/at.h>
81 #include <netatalk/at_var.h>
82 #endif
83
84 #include <security/mac/mac_framework.h>
85
86 #ifdef TINY_LOMTU
87 #define LOMTU (1024+512)
88 #elif defined(LARGE_LOMTU)
89 #define LOMTU 131072
90 #else
91 #define LOMTU 16384
92 #endif
93
94 #define LO_CSUM_FEATURES (CSUM_IP | CSUM_TCP | CSUM_UDP | CSUM_SCTP)
95 #define LO_CSUM_FEATURES6 (CSUM_TCP_IPV6 | CSUM_UDP_IPV6 | CSUM_SCTP_IPV6)
96 #define LO_CSUM_SET (CSUM_DATA_VALID | CSUM_DATA_VALID_IPV6 | \
97 CSUM_PSEUDO_HDR | \
98 CSUM_IP_CHECKED | CSUM_IP_VALID | \
99 CSUM_SCTP_VALID)
100
101 int loioctl(struct ifnet *, u_long, caddr_t);
102 static void lortrequest(int, struct rtentry *, struct rt_addrinfo *);
103 int looutput(struct ifnet *ifp, struct mbuf *m,
104 const struct sockaddr *dst, struct route *ro);
105 static int lo_clone_create(struct if_clone *, int, caddr_t);
106 static void lo_clone_destroy(struct ifnet *);
107
108 VNET_DEFINE(struct ifnet *, loif); /* Used externally */
109
110 #ifdef VIMAGE
111 static VNET_DEFINE(struct if_clone *, lo_cloner);
112 #define V_lo_cloner VNET(lo_cloner)
113 #endif
114
115 static struct if_clone *lo_cloner;
116 static const char loname[] = "lo";
117
118 static void
119 lo_clone_destroy(struct ifnet *ifp)
120 {
121
122 #ifndef VIMAGE
123 /* XXX: destroying lo0 will lead to panics. */
124 KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__));
125 #endif
126
127 bpfdetach(ifp);
128 if_detach(ifp);
129 if_free(ifp);
130 }
131
132 static int
133 lo_clone_create(struct if_clone *ifc, int unit, caddr_t params)
134 {
135 struct ifnet *ifp;
136
137 ifp = if_alloc(IFT_LOOP);
138 if (ifp == NULL)
139 return (ENOSPC);
140
141 if_initname(ifp, loname, unit);
142 ifp->if_mtu = LOMTU;
143 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
144 ifp->if_ioctl = loioctl;
145 ifp->if_output = looutput;
146 ifp->if_snd.ifq_maxlen = ifqmaxlen;
147 ifp->if_capabilities = ifp->if_capenable =
148 IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6;
149 ifp->if_hwassist = LO_CSUM_FEATURES | LO_CSUM_FEATURES6;
150 if_attach(ifp);
151 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
152 if (V_loif == NULL)
153 V_loif = ifp;
154
155 return (0);
156 }
157
158 static void
159 vnet_loif_init(const void *unused __unused)
160 {
161
162 #ifdef VIMAGE
163 lo_cloner = if_clone_simple(loname, lo_clone_create, lo_clone_destroy,
164 1);
165 V_lo_cloner = lo_cloner;
166 #else
167 lo_cloner = if_clone_simple(loname, lo_clone_create, lo_clone_destroy,
168 1);
169 #endif
170 }
171 VNET_SYSINIT(vnet_loif_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
172 vnet_loif_init, NULL);
173
174 #ifdef VIMAGE
175 static void
176 vnet_loif_uninit(const void *unused __unused)
177 {
178
179 if_clone_detach(V_lo_cloner);
180 V_loif = NULL;
181 }
182 VNET_SYSUNINIT(vnet_loif_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
183 vnet_loif_uninit, NULL);
184 #endif
185
186 static int
187 loop_modevent(module_t mod, int type, void *data)
188 {
189
190 switch (type) {
191 case MOD_LOAD:
192 break;
193
194 case MOD_UNLOAD:
195 printf("loop module unload - not possible for this module type\n");
196 return (EINVAL);
197
198 default:
199 return (EOPNOTSUPP);
200 }
201 return (0);
202 }
203
204 static moduledata_t loop_mod = {
205 "if_lo",
206 loop_modevent,
207 0
208 };
209
210 DECLARE_MODULE(if_lo, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY);
211
212 int
213 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
214 struct route *ro)
215 {
216 u_int32_t af;
217 struct rtentry *rt = NULL;
218 #ifdef MAC
219 int error;
220 #endif
221
222 M_ASSERTPKTHDR(m); /* check if we have the packet header */
223
224 if (ro != NULL)
225 rt = ro->ro_rt;
226 #ifdef MAC
227 error = mac_ifnet_check_transmit(ifp, m);
228 if (error) {
229 m_freem(m);
230 return (error);
231 }
232 #endif
233
234 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
235 m_freem(m);
236 return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
237 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
238 }
239
240 ifp->if_opackets++;
241 ifp->if_obytes += m->m_pkthdr.len;
242
243 /* BPF writes need to be handled specially. */
244 if (dst->sa_family == AF_UNSPEC || dst->sa_family == pseudo_AF_HDRCMPLT)
245 bcopy(dst->sa_data, &af, sizeof(af));
246 else
247 af = dst->sa_family;
248
249 #if 1 /* XXX */
250 switch (af) {
251 case AF_INET:
252 if (ifp->if_capenable & IFCAP_RXCSUM) {
253 m->m_pkthdr.csum_data = 0xffff;
254 m->m_pkthdr.csum_flags = LO_CSUM_SET;
255 }
256 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES;
257 break;
258 case AF_INET6:
259 #if 0
260 /*
261 * XXX-BZ for now always claim the checksum is good despite
262 * any interface flags. This is a workaround for 9.1-R and
263 * a proper solution ought to be sought later.
264 */
265 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) {
266 m->m_pkthdr.csum_data = 0xffff;
267 m->m_pkthdr.csum_flags = LO_CSUM_SET;
268 }
269 #else
270 m->m_pkthdr.csum_data = 0xffff;
271 m->m_pkthdr.csum_flags = LO_CSUM_SET;
272 #endif
273 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES6;
274 break;
275 case AF_IPX:
276 case AF_APPLETALK:
277 break;
278 default:
279 printf("looutput: af=%d unexpected\n", af);
280 m_freem(m);
281 return (EAFNOSUPPORT);
282 }
283 #endif
284 return (if_simloop(ifp, m, af, 0));
285 }
286
287 /*
288 * if_simloop()
289 *
290 * This function is to support software emulation of hardware loopback,
291 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't
292 * hear their own broadcasts, we create a copy of the packet that we
293 * would normally receive via a hardware loopback.
294 *
295 * This function expects the packet to include the media header of length hlen.
296 */
297 int
298 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen)
299 {
300 int isr;
301
302 M_ASSERTPKTHDR(m);
303 m_tag_delete_nonpersistent(m);
304 m->m_pkthdr.rcvif = ifp;
305
306 #ifdef MAC
307 mac_ifnet_create_mbuf(ifp, m);
308 #endif
309
310 /*
311 * Let BPF see incoming packet in the following manner:
312 * - Emulated packet loopback for a simplex interface
313 * (net/if_ethersubr.c)
314 * -> passes it to ifp's BPF
315 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c)
316 * -> not passes it to any BPF
317 * - Normal packet loopback from myself to myself (net/if_loop.c)
318 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0)
319 */
320 if (hlen > 0) {
321 if (bpf_peers_present(ifp->if_bpf)) {
322 bpf_mtap(ifp->if_bpf, m);
323 }
324 } else {
325 if (bpf_peers_present(V_loif->if_bpf)) {
326 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) {
327 /* XXX beware sizeof(af) != 4 */
328 u_int32_t af1 = af;
329
330 /*
331 * We need to prepend the address family.
332 */
333 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m);
334 }
335 }
336 }
337
338 /* Strip away media header */
339 if (hlen > 0) {
340 m_adj(m, hlen);
341 #ifndef __NO_STRICT_ALIGNMENT
342 /*
343 * Some archs do not like unaligned data, so
344 * we move data down in the first mbuf.
345 */
346 if (mtod(m, vm_offset_t) & 3) {
347 KASSERT(hlen >= 3, ("if_simloop: hlen too small"));
348 bcopy(m->m_data,
349 (char *)(mtod(m, vm_offset_t)
350 - (mtod(m, vm_offset_t) & 3)),
351 m->m_len);
352 m->m_data -= (mtod(m,vm_offset_t) & 3);
353 }
354 #endif
355 }
356
357 /* Deliver to upper layer protocol */
358 switch (af) {
359 #ifdef INET
360 case AF_INET:
361 isr = NETISR_IP;
362 break;
363 #endif
364 #ifdef INET6
365 case AF_INET6:
366 m->m_flags |= M_LOOP;
367 isr = NETISR_IPV6;
368 break;
369 #endif
370 #ifdef IPX
371 case AF_IPX:
372 isr = NETISR_IPX;
373 break;
374 #endif
375 #ifdef NETATALK
376 case AF_APPLETALK:
377 isr = NETISR_ATALK2;
378 break;
379 #endif
380 default:
381 printf("if_simloop: can't handle af=%d\n", af);
382 m_freem(m);
383 return (EAFNOSUPPORT);
384 }
385 ifp->if_ipackets++;
386 ifp->if_ibytes += m->m_pkthdr.len;
387 netisr_queue(isr, m); /* mbuf is free'd on failure. */
388 return (0);
389 }
390
391 /* ARGSUSED */
392 static void
393 lortrequest(int cmd, struct rtentry *rt, struct rt_addrinfo *info)
394 {
395
396 RT_LOCK_ASSERT(rt);
397 rt->rt_mtu = rt->rt_ifp->if_mtu;
398 }
399
400 /*
401 * Process an ioctl request.
402 */
403 /* ARGSUSED */
404 int
405 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
406 {
407 struct ifaddr *ifa;
408 struct ifreq *ifr = (struct ifreq *)data;
409 int error = 0, mask;
410
411 switch (cmd) {
412 case SIOCSIFADDR:
413 ifp->if_flags |= IFF_UP;
414 ifp->if_drv_flags |= IFF_DRV_RUNNING;
415 ifa = (struct ifaddr *)data;
416 ifa->ifa_rtrequest = lortrequest;
417 /*
418 * Everything else is done at a higher level.
419 */
420 break;
421
422 case SIOCADDMULTI:
423 case SIOCDELMULTI:
424 if (ifr == 0) {
425 error = EAFNOSUPPORT; /* XXX */
426 break;
427 }
428 switch (ifr->ifr_addr.sa_family) {
429
430 #ifdef INET
431 case AF_INET:
432 break;
433 #endif
434 #ifdef INET6
435 case AF_INET6:
436 break;
437 #endif
438
439 default:
440 error = EAFNOSUPPORT;
441 break;
442 }
443 break;
444
445 case SIOCSIFMTU:
446 ifp->if_mtu = ifr->ifr_mtu;
447 break;
448
449 case SIOCSIFFLAGS:
450 break;
451
452 case SIOCSIFCAP:
453 mask = ifp->if_capenable ^ ifr->ifr_reqcap;
454 if ((mask & IFCAP_RXCSUM) != 0)
455 ifp->if_capenable ^= IFCAP_RXCSUM;
456 if ((mask & IFCAP_TXCSUM) != 0)
457 ifp->if_capenable ^= IFCAP_TXCSUM;
458 if ((mask & IFCAP_RXCSUM_IPV6) != 0) {
459 #if 0
460 ifp->if_capenable ^= IFCAP_RXCSUM_IPV6;
461 #else
462 error = EOPNOTSUPP;
463 break;
464 #endif
465 }
466 if ((mask & IFCAP_TXCSUM_IPV6) != 0) {
467 #if 0
468 ifp->if_capenable ^= IFCAP_TXCSUM_IPV6;
469 #else
470 error = EOPNOTSUPP;
471 break;
472 #endif
473 }
474 ifp->if_hwassist = 0;
475 if (ifp->if_capenable & IFCAP_TXCSUM)
476 ifp->if_hwassist = LO_CSUM_FEATURES;
477 #if 0
478 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
479 ifp->if_hwassist |= LO_CSUM_FEATURES6;
480 #endif
481 break;
482
483 default:
484 error = EINVAL;
485 }
486 return (error);
487 }
Cache object: 254a9cf5dd76e338fdc08c345acf44c3
|