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 /*
33 * Loopback interface driver for protocol testing and timing.
34 */
35
36 #include "opt_inet.h"
37 #include "opt_inet6.h"
38 #include "opt_rss.h"
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/mbuf.h>
44 #include <sys/module.h>
45 #include <machine/bus.h>
46 #include <sys/rman.h>
47 #include <sys/socket.h>
48 #include <sys/sockio.h>
49 #include <sys/sysctl.h>
50
51 #include <net/if.h>
52 #include <net/if_var.h>
53 #include <net/if_private.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 INET6
67 #ifndef INET
68 #include <netinet/in.h>
69 #endif
70 #include <netinet6/in6_var.h>
71 #include <netinet/ip6.h>
72 #endif
73
74 #include <security/mac/mac_framework.h>
75
76 #ifdef TINY_LOMTU
77 #define LOMTU (1024+512)
78 #elif defined(LARGE_LOMTU)
79 #define LOMTU 131072
80 #else
81 #define LOMTU 16384
82 #endif
83
84 #define LO_CSUM_FEATURES (CSUM_IP | CSUM_TCP | CSUM_UDP | CSUM_SCTP)
85 #define LO_CSUM_FEATURES6 (CSUM_TCP_IPV6 | CSUM_UDP_IPV6 | CSUM_SCTP_IPV6)
86 #define LO_CSUM_SET (CSUM_DATA_VALID | CSUM_DATA_VALID_IPV6 | \
87 CSUM_PSEUDO_HDR | \
88 CSUM_IP_CHECKED | CSUM_IP_VALID | \
89 CSUM_SCTP_VALID)
90
91 static int loioctl(struct ifnet *, u_long, caddr_t);
92 static int looutput(struct ifnet *ifp, struct mbuf *m,
93 const struct sockaddr *dst, struct route *ro);
94
95 VNET_DEFINE(struct ifnet *, loif); /* Used externally */
96 VNET_DEFINE_STATIC(struct if_clone *, lo_cloner);
97 #define V_lo_cloner VNET(lo_cloner)
98
99 static const char loname[] = "lo";
100
101 static int
lo_clone_destroy(struct if_clone * ifc,struct ifnet * ifp,uint32_t flags)102 lo_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags)
103 {
104 if (ifp->if_dunit == 0 && (flags & IFC_F_FORCE) == 0)
105 return (EINVAL);
106
107 #ifndef VIMAGE
108 /* XXX: destroying lo0 will lead to panics. */
109 KASSERT(V_loif != ifp, ("%s: destroying lo0", __func__));
110 #endif
111
112 bpfdetach(ifp);
113 if_detach(ifp);
114 if_free(ifp);
115
116 return (0);
117 }
118
119 static int
lo_clone_create(struct if_clone * ifc,char * name,size_t len,struct ifc_data * ifd,struct ifnet ** ifpp)120 lo_clone_create(struct if_clone *ifc, char *name, size_t len,
121 struct ifc_data *ifd, struct ifnet **ifpp)
122 {
123 struct ifnet *ifp;
124
125 ifp = if_alloc(IFT_LOOP);
126 if_initname(ifp, loname, ifd->unit);
127 ifp->if_mtu = LOMTU;
128 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
129 ifp->if_ioctl = loioctl;
130 ifp->if_output = looutput;
131 ifp->if_snd.ifq_maxlen = ifqmaxlen;
132 ifp->if_capabilities = ifp->if_capenable =
133 IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6 | IFCAP_LINKSTATE;
134 ifp->if_hwassist = LO_CSUM_FEATURES | LO_CSUM_FEATURES6;
135 if_attach(ifp);
136 bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
137 *ifpp = ifp;
138
139 return (0);
140 }
141
142 static void
vnet_loif_init(const void * unused __unused)143 vnet_loif_init(const void *unused __unused)
144 {
145 struct if_clone_addreq req = {
146 .create_f = lo_clone_create,
147 .destroy_f = lo_clone_destroy,
148 .flags = IFC_F_AUTOUNIT,
149 };
150 V_lo_cloner = ifc_attach_cloner(loname, &req);
151 struct ifc_data ifd = { .unit = 0 };
152 ifc_create_ifp(loname, &ifd, &V_loif);
153 }
154 VNET_SYSINIT(vnet_loif_init, SI_SUB_PSEUDO, SI_ORDER_ANY,
155 vnet_loif_init, NULL);
156
157 #ifdef VIMAGE
158 static void
vnet_loif_uninit(const void * unused __unused)159 vnet_loif_uninit(const void *unused __unused)
160 {
161
162 ifc_detach_cloner(V_lo_cloner);
163 V_loif = NULL;
164 }
165 VNET_SYSUNINIT(vnet_loif_uninit, SI_SUB_INIT_IF, SI_ORDER_SECOND,
166 vnet_loif_uninit, NULL);
167 #endif
168
169 static int
loop_modevent(module_t mod,int type,void * data)170 loop_modevent(module_t mod, int type, void *data)
171 {
172
173 switch (type) {
174 case MOD_LOAD:
175 break;
176
177 case MOD_UNLOAD:
178 printf("loop module unload - not possible for this module type\n");
179 return (EINVAL);
180
181 default:
182 return (EOPNOTSUPP);
183 }
184 return (0);
185 }
186
187 static moduledata_t loop_mod = {
188 "if_lo",
189 loop_modevent,
190 0
191 };
192
193 DECLARE_MODULE(if_lo, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY);
194
195 static int
looutput(struct ifnet * ifp,struct mbuf * m,const struct sockaddr * dst,struct route * ro)196 looutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
197 struct route *ro)
198 {
199 u_int32_t af;
200 #ifdef MAC
201 int error;
202 #endif
203
204 M_ASSERTPKTHDR(m); /* check if we have the packet header */
205
206 #ifdef MAC
207 error = mac_ifnet_check_transmit(ifp, m);
208 if (error) {
209 m_freem(m);
210 return (error);
211 }
212 #endif
213
214 if (ro != NULL && ro->ro_flags & (RT_REJECT|RT_BLACKHOLE)) {
215 m_freem(m);
216 return (ro->ro_flags & RT_BLACKHOLE ? 0 : EHOSTUNREACH);
217 }
218
219 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
220 if_inc_counter(ifp, IFCOUNTER_OBYTES, m->m_pkthdr.len);
221
222 M_HASHTYPE_CLEAR(m);
223
224 /* BPF writes need to be handled specially. */
225 if (dst->sa_family == AF_UNSPEC || dst->sa_family == pseudo_AF_HDRCMPLT)
226 bcopy(dst->sa_data, &af, sizeof(af));
227 else
228 af = RO_GET_FAMILY(ro, dst);
229
230 #if 1 /* XXX */
231 switch (af) {
232 case AF_INET:
233 if (ifp->if_capenable & IFCAP_RXCSUM) {
234 m->m_pkthdr.csum_data = 0xffff;
235 m->m_pkthdr.csum_flags = LO_CSUM_SET;
236 }
237 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES;
238 break;
239 case AF_INET6:
240 #if 0
241 /*
242 * XXX-BZ for now always claim the checksum is good despite
243 * any interface flags. This is a workaround for 9.1-R and
244 * a proper solution ought to be sought later.
245 */
246 if (ifp->if_capenable & IFCAP_RXCSUM_IPV6) {
247 m->m_pkthdr.csum_data = 0xffff;
248 m->m_pkthdr.csum_flags = LO_CSUM_SET;
249 }
250 #else
251 m->m_pkthdr.csum_data = 0xffff;
252 m->m_pkthdr.csum_flags = LO_CSUM_SET;
253 #endif
254 m->m_pkthdr.csum_flags &= ~LO_CSUM_FEATURES6;
255 break;
256 default:
257 printf("looutput: af=%d unexpected\n", af);
258 m_freem(m);
259 return (EAFNOSUPPORT);
260 }
261 #endif
262 return (if_simloop(ifp, m, af, 0));
263 }
264
265 /*
266 * if_simloop()
267 *
268 * This function is to support software emulation of hardware loopback,
269 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't
270 * hear their own broadcasts, we create a copy of the packet that we
271 * would normally receive via a hardware loopback.
272 *
273 * This function expects the packet to include the media header of length hlen.
274 */
275 int
if_simloop(struct ifnet * ifp,struct mbuf * m,int af,int hlen)276 if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen)
277 {
278 int isr;
279
280 M_ASSERTPKTHDR(m);
281 m_tag_delete_nonpersistent(m);
282 m->m_pkthdr.rcvif = ifp;
283
284 #ifdef MAC
285 mac_ifnet_create_mbuf(ifp, m);
286 #endif
287
288 /*
289 * Let BPF see incoming packet in the following manner:
290 * - Emulated packet loopback for a simplex interface
291 * (net/if_ethersubr.c)
292 * -> passes it to ifp's BPF
293 * - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c)
294 * -> not passes it to any BPF
295 * - Normal packet loopback from myself to myself (net/if_loop.c)
296 * -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0)
297 */
298 if (hlen > 0) {
299 if (bpf_peers_present(ifp->if_bpf)) {
300 bpf_mtap(ifp->if_bpf, m);
301 }
302 } else {
303 if (bpf_peers_present(V_loif->if_bpf)) {
304 if ((m->m_flags & M_MCAST) == 0 || V_loif == ifp) {
305 /* XXX beware sizeof(af) != 4 */
306 u_int32_t af1 = af;
307
308 /*
309 * We need to prepend the address family.
310 */
311 bpf_mtap2(V_loif->if_bpf, &af1, sizeof(af1), m);
312 }
313 }
314 }
315
316 /* Strip away media header */
317 if (hlen > 0) {
318 m_adj(m, hlen);
319 #ifndef __NO_STRICT_ALIGNMENT
320 /*
321 * Some archs do not like unaligned data, so
322 * we move data down in the first mbuf.
323 */
324 if (mtod(m, vm_offset_t) & 3) {
325 KASSERT(hlen >= 3, ("if_simloop: hlen too small"));
326 bcopy(m->m_data,
327 (char *)(mtod(m, vm_offset_t)
328 - (mtod(m, vm_offset_t) & 3)),
329 m->m_len);
330 m->m_data -= (mtod(m,vm_offset_t) & 3);
331 }
332 #endif
333 }
334
335 /* Deliver to upper layer protocol */
336 switch (af) {
337 #ifdef INET
338 case AF_INET:
339 isr = NETISR_IP;
340 break;
341 #endif
342 #ifdef INET6
343 case AF_INET6:
344 m->m_flags |= M_LOOP;
345 isr = NETISR_IPV6;
346 break;
347 #endif
348 default:
349 printf("if_simloop: can't handle af=%d\n", af);
350 m_freem(m);
351 return (EAFNOSUPPORT);
352 }
353 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
354 if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);
355 netisr_queue(isr, m); /* mbuf is free'd on failure. */
356 return (0);
357 }
358
359 /*
360 * Process an ioctl request.
361 */
362 static int
loioctl(struct ifnet * ifp,u_long cmd,caddr_t data)363 loioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
364 {
365 struct ifreq *ifr = (struct ifreq *)data;
366 int error = 0, mask;
367
368 switch (cmd) {
369 case SIOCSIFADDR:
370 ifp->if_flags |= IFF_UP;
371 ifp->if_drv_flags |= IFF_DRV_RUNNING;
372 if_link_state_change(ifp, LINK_STATE_UP);
373 /*
374 * Everything else is done at a higher level.
375 */
376 break;
377
378 case SIOCADDMULTI:
379 case SIOCDELMULTI:
380 if (ifr == NULL) {
381 error = EAFNOSUPPORT; /* XXX */
382 break;
383 }
384 switch (ifr->ifr_addr.sa_family) {
385 #ifdef INET
386 case AF_INET:
387 break;
388 #endif
389 #ifdef INET6
390 case AF_INET6:
391 break;
392 #endif
393
394 default:
395 error = EAFNOSUPPORT;
396 break;
397 }
398 break;
399
400 case SIOCSIFMTU:
401 ifp->if_mtu = ifr->ifr_mtu;
402 break;
403
404 case SIOCSIFFLAGS:
405 if_link_state_change(ifp, (ifp->if_flags & IFF_UP) ?
406 LINK_STATE_UP: LINK_STATE_DOWN);
407 break;
408
409 case SIOCSIFCAP:
410 mask = ifp->if_capenable ^ ifr->ifr_reqcap;
411 if ((mask & IFCAP_RXCSUM) != 0)
412 ifp->if_capenable ^= IFCAP_RXCSUM;
413 if ((mask & IFCAP_TXCSUM) != 0)
414 ifp->if_capenable ^= IFCAP_TXCSUM;
415 if ((mask & IFCAP_RXCSUM_IPV6) != 0) {
416 #if 0
417 ifp->if_capenable ^= IFCAP_RXCSUM_IPV6;
418 #else
419 error = EOPNOTSUPP;
420 break;
421 #endif
422 }
423 if ((mask & IFCAP_TXCSUM_IPV6) != 0) {
424 #if 0
425 ifp->if_capenable ^= IFCAP_TXCSUM_IPV6;
426 #else
427 error = EOPNOTSUPP;
428 break;
429 #endif
430 }
431 ifp->if_hwassist = 0;
432 if (ifp->if_capenable & IFCAP_TXCSUM)
433 ifp->if_hwassist = LO_CSUM_FEATURES;
434 #if 0
435 if (ifp->if_capenable & IFCAP_TXCSUM_IPV6)
436 ifp->if_hwassist |= LO_CSUM_FEATURES6;
437 #endif
438 break;
439
440 default:
441 error = EINVAL;
442 }
443 return (error);
444 }
445