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if_loop.c revision 1.43 
      1 /*	$NetBSD: if_loop.c,v 1.43 2003/05/01 07:52:58 itojun 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. All advertising materials mentioning features or use of this software
     45  *    must display the following acknowledgement:
     46  *	This product includes software developed by the University of
     47  *	California, Berkeley and its contributors.
     48  * 4. Neither the name of the University nor the names of its contributors
     49  *    may be used to endorse or promote products derived from this software
     50  *    without specific prior written permission.
     51  *
     52  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     53  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     54  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     55  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     56  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     57  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     58  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     59  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     60  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     61  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     62  * SUCH DAMAGE.
     63  *
     64  *	@(#)if_loop.c	8.2 (Berkeley) 1/9/95
     65  */
     66 
     67 /*
     68  * Loopback interface driver for protocol testing and timing.
     69  */
     70 
     71 #include <sys/cdefs.h>
     72 __KERNEL_RCSID(0, "$NetBSD: if_loop.c,v 1.43 2003/05/01 07:52:58 itojun Exp $");
     73 
     74 #include "opt_inet.h"
     75 #include "opt_atalk.h"
     76 #include "opt_iso.h"
     77 #include "opt_ns.h"
     78 
     79 #include "bpfilter.h"
     80 #include "loop.h"
     81 
     82 #include <sys/param.h>
     83 #include <sys/systm.h>
     84 #include <sys/kernel.h>
     85 #include <sys/mbuf.h>
     86 #include <sys/socket.h>
     87 #include <sys/errno.h>
     88 #include <sys/ioctl.h>
     89 #include <sys/time.h>
     90 
     91 #include <machine/cpu.h>
     92 
     93 #include <net/if.h>
     94 #include <net/if_types.h>
     95 #include <net/netisr.h>
     96 #include <net/route.h>
     97 
     98 #ifdef	INET
     99 #include <netinet/in.h>
    100 #include <netinet/in_systm.h>
    101 #include <netinet/in_var.h>
    102 #include <netinet/ip.h>
    103 #endif
    104 
    105 #ifdef INET6
    106 #ifndef INET
    107 #include <netinet/in.h>
    108 #endif
    109 #include <netinet6/in6_var.h>
    110 #include <netinet/ip6.h>
    111 #endif
    112 
    113 #ifdef NS
    114 #include <netns/ns.h>
    115 #include <netns/ns_if.h>
    116 #endif
    117 
    118 #ifdef IPX
    119 #include <netipx/ipx.h>
    120 #include <netipx/ipx_if.h>
    121 #endif
    122 
    123 #ifdef ISO
    124 #include <netiso/iso.h>
    125 #include <netiso/iso_var.h>
    126 #endif
    127 
    128 #ifdef NETATALK
    129 #include <netatalk/at.h>
    130 #include <netatalk/at_var.h>
    131 #endif
    132 
    133 #if NBPFILTER > 0
    134 #include <net/bpf.h>
    135 #endif
    136 
    137 #if defined(LARGE_LOMTU)
    138 #define LOMTU	(131072 +  MHLEN + MLEN)
    139 #else
    140 #define	LOMTU	(32768 +  MHLEN + MLEN)
    141 #endif
    142 
    143 struct	ifnet loif[NLOOP];
    144 #ifdef MBUFTRACE
    145 struct	mowner lomowner[NLOOP];
    146 #endif
    147 
    148 #ifdef ALTQ
    149 void	lostart(struct ifnet *);
    150 #endif
    151 
    152 void
    153 loopattach(n)
    154 	int n;
    155 {
    156 	int i;
    157 	struct ifnet *ifp;
    158 
    159 	for (i = 0; i < NLOOP; i++) {
    160 		ifp = &loif[i];
    161 		sprintf(ifp->if_xname, "lo%d", i);
    162 		ifp->if_softc = NULL;
    163 		ifp->if_mtu = LOMTU;
    164 		ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
    165 		ifp->if_ioctl = loioctl;
    166 		ifp->if_output = looutput;
    167 #ifdef ALTQ
    168 		ifp->if_start = lostart;
    169 #endif
    170 		ifp->if_type = IFT_LOOP;
    171 		ifp->if_hdrlen = 0;
    172 		ifp->if_addrlen = 0;
    173 		ifp->if_dlt = DLT_NULL;
    174 		IFQ_SET_READY(&ifp->if_snd);
    175 		if_attach(ifp);
    176 		if_alloc_sadl(ifp);
    177 #if NBPFILTER > 0
    178 		bpfattach(ifp, DLT_NULL, sizeof(u_int));
    179 #endif
    180 #ifdef MBUFTRACE
    181 		ifp->if_mowner = &lomowner[i];
    182 		strcpy(ifp->if_mowner->mo_name, ifp->if_xname);
    183 		MOWNER_ATTACH(&lomowner[i]);
    184 #endif
    185 	}
    186 }
    187 
    188 int
    189 looutput(ifp, m, dst, rt)
    190 	struct ifnet *ifp;
    191 	struct mbuf *m;
    192 	struct sockaddr *dst;
    193 	struct rtentry *rt;
    194 {
    195 	int s, isr;
    196 	struct ifqueue *ifq = 0;
    197 
    198 	MCLAIM(m, ifp->if_mowner);
    199 	if ((m->m_flags & M_PKTHDR) == 0)
    200 		panic("looutput: no header mbuf");
    201 #if NBPFILTER > 0
    202 	if (ifp->if_bpf && (ifp->if_flags & IFF_LOOPBACK)) {
    203 		/*
    204 		 * We need to prepend the address family as
    205 		 * a four byte field.  Cons up a dummy header
    206 		 * to pacify bpf.  This is safe because bpf
    207 		 * will only read from the mbuf (i.e., it won't
    208 		 * try to free it or keep a pointer to it).
    209 		 */
    210 		struct mbuf m0;
    211 		u_int32_t af = dst->sa_family;
    212 
    213 		m0.m_flags = 0;
    214 		m0.m_next = m;
    215 		m0.m_len = 4;
    216 		m0.m_data = (char *)&af;
    217 
    218 		bpf_mtap(ifp->if_bpf, &m0);
    219 	}
    220 #endif
    221 	m->m_pkthdr.rcvif = ifp;
    222 
    223 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
    224 		m_freem(m);
    225 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
    226 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
    227 	}
    228 
    229 #ifndef PULLDOWN_TEST
    230 	/*
    231 	 * KAME requires that the packet to be contiguous on the
    232 	 * mbuf.  We need to make that sure.
    233 	 * this kind of code should be avoided.
    234 	 * XXX other conditions to avoid running this part?
    235 	 */
    236 	if (m->m_len != m->m_pkthdr.len) {
    237 		struct mbuf *n = NULL;
    238 		int maxlen;
    239 
    240 		MGETHDR(n, M_DONTWAIT, MT_HEADER);
    241 		maxlen = MHLEN;
    242 		if (n)
    243 			M_COPY_PKTHDR(n, m);
    244 		if (n && m->m_pkthdr.len > maxlen) {
    245 			MCLGET(n, M_DONTWAIT);
    246 			maxlen = MCLBYTES;
    247 			if ((n->m_flags & M_EXT) == 0) {
    248 				m_free(n);
    249 				n = NULL;
    250 			}
    251 		}
    252 		if (!n) {
    253 			printf("looutput: mbuf allocation failed\n");
    254 			m_freem(m);
    255 			return ENOBUFS;
    256 		}
    257 
    258 		if (m->m_pkthdr.len <= maxlen) {
    259 			m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t));
    260 			n->m_len = m->m_pkthdr.len;
    261 			n->m_next = NULL;
    262 			m_freem(m);
    263 		} else {
    264 			m_copydata(m, 0, maxlen, mtod(n, caddr_t));
    265 			m_adj(m, maxlen);
    266 			n->m_len = maxlen;
    267 			n->m_next = m;
    268 			m->m_flags &= ~M_PKTHDR;
    269 		}
    270 		m = n;
    271 	}
    272 #if 0
    273 	if (m && m->m_next != NULL) {
    274 		printf("loop: not contiguous...\n");
    275 		m_freem(m);
    276 		return ENOBUFS;
    277 	}
    278 #endif
    279 #endif
    280 
    281 	ifp->if_opackets++;
    282 	ifp->if_obytes += m->m_pkthdr.len;
    283 
    284 #ifdef ALTQ
    285 	/*
    286 	 * ALTQ on the loopback interface is just for debugging.  It's
    287 	 * used only for loopback interfaces, not for a simplex interface.
    288 	 */
    289 	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
    290 	    ifp->if_start == lostart) {
    291 		struct altq_pktattr pktattr;
    292 		int error;
    293 
    294 		/*
    295 		 * If the queueing discipline needs packet classification,
    296 		 * do it before prepending the link headers.
    297 		 */
    298 		IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
    299 
    300 		M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
    301 		if (m == NULL)
    302 			return (ENOBUFS);
    303 		*(mtod(m, uint32_t *)) = dst->sa_family;
    304 
    305 		s = splnet();
    306 		IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
    307 		(*ifp->if_start)(ifp);
    308 		splx(s);
    309 		return (error);
    310 	}
    311 #endif /* ALTQ */
    312 
    313 	switch (dst->sa_family) {
    314 
    315 #ifdef INET
    316 	case AF_INET:
    317 		ifq = &ipintrq;
    318 		isr = NETISR_IP;
    319 		break;
    320 #endif
    321 #ifdef INET6
    322 	case AF_INET6:
    323 		m->m_flags |= M_LOOP;
    324 		ifq = &ip6intrq;
    325 		isr = NETISR_IPV6;
    326 		break;
    327 #endif
    328 #ifdef NS
    329 	case AF_NS:
    330 		ifq = &nsintrq;
    331 		isr = NETISR_NS;
    332 		break;
    333 #endif
    334 #ifdef ISO
    335 	case AF_ISO:
    336 		ifq = &clnlintrq;
    337 		isr = NETISR_ISO;
    338 		break;
    339 #endif
    340 #ifdef IPX
    341 	case AF_IPX:
    342 		ifq = &ipxintrq;
    343 		isr = NETISR_IPX;
    344 		break;
    345 #endif
    346 #ifdef NETATALK
    347 	case AF_APPLETALK:
    348 	        ifq = &atintrq2;
    349 		isr = NETISR_ATALK;
    350 		break;
    351 #endif
    352 	default:
    353 		printf("%s: can't handle af%d\n", ifp->if_xname,
    354 		    dst->sa_family);
    355 		m_freem(m);
    356 		return (EAFNOSUPPORT);
    357 	}
    358 	s = splnet();
    359 	if (IF_QFULL(ifq)) {
    360 		IF_DROP(ifq);
    361 		m_freem(m);
    362 		splx(s);
    363 		return (ENOBUFS);
    364 	}
    365 	IF_ENQUEUE(ifq, m);
    366 	schednetisr(isr);
    367 	ifp->if_ipackets++;
    368 	ifp->if_ibytes += m->m_pkthdr.len;
    369 	splx(s);
    370 	return (0);
    371 }
    372 
    373 #ifdef ALTQ
    374 void
    375 lostart(struct ifnet *ifp)
    376 {
    377 	struct ifqueue *ifq;
    378 	struct mbuf *m;
    379 	uint32_t af;
    380 	int s, isr;
    381 
    382 	for (;;) {
    383 		IFQ_DEQUEUE(&ifp->if_snd, m);
    384 		if (m == NULL)
    385 			return;
    386 
    387 		af = *(mtod(m, uint32_t *));
    388 		m_adj(m, sizeof(uint32_t));
    389 
    390 		switch (af) {
    391 #ifdef INET
    392 		case AF_INET:
    393 			ifq = &ipintrq;
    394 			isr = NETISR_IP;
    395 			break;
    396 #endif
    397 #ifdef INET6
    398 		case AF_INET6:
    399 			m->m_flags |= M_LOOP;
    400 			ifq = &ip6intrq;
    401 			isr = NETISR_IPV6;
    402 			break;
    403 #endif
    404 #ifdef IPX
    405 		case AF_IPX:
    406 			ifq = &ipxintrq;
    407 			isr = NETISR_IPX;
    408 			break;
    409 #endif
    410 #ifdef NS
    411 		case AF_NS:
    412 			ifq = &nsintrq;
    413 			isr = NETISR_NS;
    414 			break;
    415 #endif
    416 #ifdef ISO
    417 		case AF_ISO:
    418 			ifq = &clnlintrq;
    419 			isr = NETISR_ISO;
    420 			break;
    421 #endif
    422 #ifdef NETATALK
    423 		case AF_APPLETALK:
    424 			ifq = &atintrq2;
    425 			isr = NETISR_ATALK;
    426 			break;
    427 #endif
    428 		default:
    429 			printf("%s: can't handle af%d\n", ifp->if_xname, af);
    430 			m_freem(m);
    431 			return;
    432 		}
    433 
    434 		s = splnet();
    435 		if (IF_QFULL(ifq)) {
    436 			IF_DROP(ifq);
    437 			splx(s);
    438 			m_freem(m);
    439 			return;
    440 		}
    441 		IF_ENQUEUE(ifq, m);
    442 		schednetisr(isr);
    443 		ifp->if_ipackets++;
    444 		ifp->if_ibytes += m->m_pkthdr.len;
    445 		splx(s);
    446 	}
    447 }
    448 #endif /* ALTQ */
    449 
    450 /* ARGSUSED */
    451 void
    452 lortrequest(cmd, rt, info)
    453 	int cmd;
    454 	struct rtentry *rt;
    455 	struct rt_addrinfo *info;
    456 {
    457 
    458 	if (rt)
    459 		rt->rt_rmx.rmx_mtu = LOMTU;
    460 }
    461 
    462 /*
    463  * Process an ioctl request.
    464  */
    465 /* ARGSUSED */
    466 int
    467 loioctl(ifp, cmd, data)
    468 	struct ifnet *ifp;
    469 	u_long cmd;
    470 	caddr_t data;
    471 {
    472 	struct ifaddr *ifa;
    473 	struct ifreq *ifr;
    474 	int error = 0;
    475 
    476 	switch (cmd) {
    477 
    478 	case SIOCSIFADDR:
    479 		ifp->if_flags |= IFF_UP;
    480 		ifa = (struct ifaddr *)data;
    481 		if (ifa != 0 /*&& ifa->ifa_addr->sa_family == AF_ISO*/)
    482 			ifa->ifa_rtrequest = lortrequest;
    483 		/*
    484 		 * Everything else is done at a higher level.
    485 		 */
    486 		break;
    487 
    488 	case SIOCADDMULTI:
    489 	case SIOCDELMULTI:
    490 		ifr = (struct ifreq *)data;
    491 		if (ifr == 0) {
    492 			error = EAFNOSUPPORT;		/* XXX */
    493 			break;
    494 		}
    495 		switch (ifr->ifr_addr.sa_family) {
    496 
    497 #ifdef INET
    498 		case AF_INET:
    499 			break;
    500 #endif
    501 #ifdef INET6
    502 		case AF_INET6:
    503 			break;
    504 #endif
    505 
    506 		default:
    507 			error = EAFNOSUPPORT;
    508 			break;
    509 		}
    510 		break;
    511 
    512 	default:
    513 		error = EINVAL;
    514 	}
    515 	return (error);
    516 }
    517