bridge: Fix comment.
[dragonfly.git] / sys / net / if_loop.c
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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.
dc71b7ab 13 * 3. Neither the name of the University nor the names of its contributors
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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 8.1 (Berkeley) 6/10/93
1fd46b85 30 * $FreeBSD: src/sys/net/if_loop.c,v 1.47.2.9 2004/02/08 08:40:24 silby Exp $
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31 */
32
33/*
34 * Loopback interface driver for protocol testing and timing.
35 */
1f2de5d4 36#include "use_loop.h"
984263bc 37
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38#include "opt_inet.h"
39#include "opt_inet6.h"
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40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/kernel.h>
82c6f048 44#include <sys/lock.h>
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45#include <sys/mbuf.h>
46#include <sys/socket.h>
47#include <sys/sockio.h>
48
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49#include <sys/mplock2.h>
50
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51#include <net/if.h>
52#include <net/if_types.h>
4d723e5a 53#include <net/ifq_var.h>
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54#include <net/netisr.h>
55#include <net/route.h>
56#include <net/bpf.h>
57#include <net/bpfdesc.h>
58
59#ifdef INET
60#include <netinet/in.h>
61#include <netinet/in_var.h>
62#endif
63
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64#ifdef INET6
65#ifndef INET
66#include <netinet/in.h>
67#endif
68#include <netinet6/in6_var.h>
69#include <netinet/ip6.h>
70#endif
71
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72static void loopattach(void *);
73static int looutput(struct ifnet *, struct mbuf *, struct sockaddr *,
74 struct rtentry *);
75static int loioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
3ffea39d 76static void lortrequest(int, struct rtentry *);
4d723e5a 77#ifdef ALTQ
f0a26983 78static void lo_altqstart(struct ifnet *, struct ifaltq_subque *);
4d723e5a 79#endif
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80PSEUDO_SET(loopattach, if_loop);
81
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82#ifdef TINY_LOMTU
83#define LOMTU (1024+512)
84#elif defined(LARGE_LOMTU)
85#define LOMTU 131072
86#else
87#define LOMTU 16384
88#endif
89
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90#define LO_CSUM_FEATURES (CSUM_IP | CSUM_UDP | CSUM_TCP)
91
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92struct ifnet loif[NLOOP];
93
94/* ARGSUSED */
95static void
f23061d4 96loopattach(void *dummy)
984263bc 97{
82ed7fc2 98 struct ifnet *ifp;
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99 int i;
100
101 for (i = 0, ifp = loif; i < NLOOP; i++, ifp++) {
102 if_initname(ifp, "lo", i);
103 ifp->if_mtu = LOMTU;
104 ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
8d4ec101 105 ifp->if_capabilities = IFCAP_HWCSUM | IFCAP_RSS;
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106 ifp->if_hwassist = LO_CSUM_FEATURES;
107 ifp->if_capenable = ifp->if_capabilities;
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108 ifp->if_ioctl = loioctl;
109 ifp->if_output = looutput;
110 ifp->if_type = IFT_LOOP;
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111 ifq_set_maxlen(&ifp->if_snd, ifqmaxlen);
112 ifq_set_ready(&ifp->if_snd);
113#ifdef ALTQ
114 ifp->if_start = lo_altqstart;
115#endif
78195a76 116 if_attach(ifp, NULL);
f23061d4 117 bpfattach(ifp, DLT_NULL, sizeof(u_int));
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118 }
119}
120
7d982e78 121static int
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122looutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
123 struct rtentry *rt)
984263bc 124{
2d2b761b 125 M_ASSERTPKTHDR(m);
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126
127 if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
128 m_freem(m);
129 return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
130 rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
131 }
984263bc 132
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133 IFNET_STAT_INC(ifp, opackets, 1);
134 IFNET_STAT_INC(ifp, obytes, m->m_pkthdr.len);
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135#if 1 /* XXX */
136 switch (dst->sa_family) {
137 case AF_INET:
138 case AF_INET6:
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139 break;
140 default:
4b1cf444 141 kprintf("looutput: af=%d unexpected\n", dst->sa_family);
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142 m_freem(m);
143 return (EAFNOSUPPORT);
144 }
145#endif
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146
147 if (ifp->if_capenable & IFCAP_RXCSUM) {
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148 int csum_flags = 0;
149
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150 if (m->m_pkthdr.csum_flags & CSUM_IP)
151 csum_flags |= (CSUM_IP_CHECKED | CSUM_IP_VALID);
152 if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA)
153 csum_flags |= (CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
154
155 m->m_pkthdr.csum_flags |= csum_flags;
156 if (csum_flags & CSUM_DATA_VALID)
157 m->m_pkthdr.csum_data = 0xffff;
158 }
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159 if ((ifp->if_capenable & IFCAP_RSS) == 0)
160 m->m_flags &= ~M_HASH;
f23061d4 161 return (if_simloop(ifp, m, dst->sa_family, 0));
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162}
163
164/*
165 * if_simloop()
166 *
167 * This function is to support software emulation of hardware loopback,
168 * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't
169 * hear their own broadcasts, we create a copy of the packet that we
170 * would normally receive via a hardware loopback.
171 *
172 * This function expects the packet to include the media header of length hlen.
173 */
984263bc 174int
f23061d4 175if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen)
984263bc 176{
8bde602d 177 int isr;
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178
179 KASSERT((m->m_flags & M_PKTHDR) != 0, ("if_simloop: no HDR"));
180 m->m_pkthdr.rcvif = ifp;
181
182 /* BPF write needs to be handled specially */
183 if (af == AF_UNSPEC) {
184 KASSERT(m->m_len >= sizeof(int), ("if_simloop: m_len"));
185 af = *(mtod(m, int *));
186 m->m_len -= sizeof(int);
187 m->m_pkthdr.len -= sizeof(int);
188 m->m_data += sizeof(int);
189 }
190
984263bc 191 if (ifp->if_bpf) {
fda7d388 192 bpf_gettoken();
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193
194 /* Re-check */
195 if (ifp->if_bpf == NULL)
196 goto rel;
197
984263bc 198 if (ifp->if_bpf->bif_dlt == DLT_NULL) {
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199 uint32_t bpf_af = (uint32_t)af;
200 bpf_ptap(ifp->if_bpf, m, &bpf_af, 4);
82c6f048 201 } else {
1f8e62c9 202 bpf_mtap(ifp->if_bpf, m);
984263bc 203 }
82c6f048 204rel:
fda7d388 205 bpf_reltoken();
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206 }
207
208 /* Strip away media header */
469ac2dc 209 if (hlen > 0)
984263bc 210 m_adj(m, hlen);
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211
212#ifdef ALTQ
213 /*
214 * altq for loop is just for debugging.
215 * only used when called for loop interface (not for
216 * a simplex interface).
217 */
218 if (ifq_is_enabled(&ifp->if_snd) && ifp->if_start == lo_altqstart) {
219 struct altq_pktattr pktattr;
220 int32_t *afp;
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221
222 /*
223 * if the queueing discipline needs packet classification,
224 * do it before prepending link headers.
225 */
226 ifq_classify(&ifp->if_snd, m, af, &pktattr);
227
b5523eac 228 M_PREPEND(m, sizeof(int32_t), M_NOWAIT);
4090d6ff 229 if (m == NULL)
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230 return(ENOBUFS);
231 afp = mtod(m, int32_t *);
232 *afp = (int32_t)af;
233
3c4cd924 234 return ifq_dispatch(ifp, m, &pktattr);
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235 }
236#endif /* ALTQ */
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237
238 /* Deliver to upper layer protocol */
239 switch (af) {
240#ifdef INET
241 case AF_INET:
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242 isr = NETISR_IP;
243 break;
244#endif
245#ifdef INET6
246 case AF_INET6:
247 m->m_flags |= M_LOOP;
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248 isr = NETISR_IPV6;
249 break;
f7ea898e 250#endif
984263bc 251 default:
4b1cf444 252 kprintf("if_simloop: can't handle af=%d\n", af);
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253 m_freem(m);
254 return (EAFNOSUPPORT);
255 }
8bde602d 256
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257 IFNET_STAT_INC(ifp, ipackets, 1);
258 IFNET_STAT_INC(ifp, ibytes, m->m_pkthdr.len);
8bde602d 259 netisr_queue(isr, m);
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260 return (0);
261}
262
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263#ifdef ALTQ
264static void
f0a26983 265lo_altqstart(struct ifnet *ifp, struct ifaltq_subque *ifsq)
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266{
267 struct mbuf *m;
268 int32_t af, *afp;
4986965b 269 int isr;
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270
271 while (1) {
4986965b 272 crit_enter();
ac9843a1 273 m = ifsq_dequeue(ifsq);
4986965b 274 crit_exit();
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275 if (m == NULL)
276 return;
277
278 afp = mtod(m, int32_t *);
279 af = *afp;
280 m_adj(m, sizeof(int32_t));
281
282 switch (af) {
283#ifdef INET
284 case AF_INET:
285 isr = NETISR_IP;
286 break;
287#endif
288#ifdef INET6
289 case AF_INET6:
290 m->m_flags |= M_LOOP;
291 isr = NETISR_IPV6;
292 break;
ffd619d1 293#endif
4d723e5a 294 default:
4b1cf444 295 kprintf("lo_altqstart: can't handle af%d\n", af);
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296 m_freem(m);
297 return;
298 }
299
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300 IFNET_STAT_INC(ifp, ipackets, 1);
301 IFNET_STAT_INC(ifp, ibytes, m->m_pkthdr.len);
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302 netisr_queue(isr, m);
303 }
304}
305#endif /* ALTQ */
306
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307/* ARGSUSED */
308static void
3ffea39d 309lortrequest(int cmd, struct rtentry *rt)
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310{
311 if (rt) {
312 rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu; /* for ISO */
313 /*
314 * For optimal performance, the send and receive buffers
315 * should be at least twice the MTU plus a little more for
316 * overhead.
317 */
f23061d4 318 rt->rt_rmx.rmx_recvpipe = rt->rt_rmx.rmx_sendpipe = 3 * LOMTU;
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319 }
320}
321
322/*
323 * Process an ioctl request.
324 */
325/* ARGSUSED */
7d982e78 326static int
f23061d4 327loioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
984263bc 328{
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329 struct ifaddr *ifa;
330 struct ifreq *ifr = (struct ifreq *)data;
72662a67 331 int error = 0, mask;
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332
333 switch (cmd) {
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334 case SIOCSIFADDR:
335 ifp->if_flags |= IFF_UP | IFF_RUNNING;
336 ifa = (struct ifaddr *)data;
337 ifa->ifa_rtrequest = lortrequest;
338 /*
339 * Everything else is done at a higher level.
340 */
341 break;
342
343 case SIOCADDMULTI:
344 case SIOCDELMULTI:
4090d6ff 345 if (ifr == NULL) {
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346 error = EAFNOSUPPORT; /* XXX */
347 break;
348 }
349 switch (ifr->ifr_addr.sa_family) {
350
351#ifdef INET
352 case AF_INET:
353 break;
354#endif
355#ifdef INET6
356 case AF_INET6:
357 break;
358#endif
359
360 default:
361 error = EAFNOSUPPORT;
362 break;
363 }
364 break;
365
366 case SIOCSIFMTU:
367 ifp->if_mtu = ifr->ifr_mtu;
368 break;
369
370 case SIOCSIFFLAGS:
371 break;
372
72662a67 373 case SIOCSIFCAP:
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374 mask = ifr->ifr_reqcap ^ ifp->if_capenable;
375 if (mask & IFCAP_HWCSUM) {
376 ifp->if_capenable ^= (mask & IFCAP_HWCSUM);
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377 if (IFCAP_TXCSUM & ifp->if_capenable)
378 ifp->if_hwassist = LO_CSUM_FEATURES;
379 else
380 ifp->if_hwassist = 0;
381 }
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382 if (mask & IFCAP_RSS)
383 ifp->if_capenable ^= IFCAP_RSS;
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384 break;
385
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386 default:
387 error = EINVAL;
388 }
389 return (error);
390}