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if_loop.c revision 1.40 
      1 /*	$NetBSD: if_loop.c,v 1.40 2001/11/12 23:49:40 lukem 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 1.40 2001/11/12 23:49:40 lukem 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 
    145 #ifdef ALTQ
    146 void	lostart(struct ifnet *);
    147 #endif
    148 
    149 void
    150 loopattach(n)
    151 	int n;
    152 {
    153 	int i;
    154 	struct ifnet *ifp;
    155 
    156 	for (i = 0; i < NLOOP; i++) {
    157 		ifp = &loif[i];
    158 		sprintf(ifp->if_xname, "lo%d", i);
    159 		ifp->if_softc = NULL;
    160 		ifp->if_mtu = LOMTU;
    161 		ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
    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_attach(ifp);
    173 		if_alloc_sadl(ifp);
    174 #if NBPFILTER > 0
    175 		bpfattach(ifp, DLT_NULL, sizeof(u_int));
    176 #endif
    177 	}
    178 }
    179 
    180 int
    181 looutput(ifp, m, dst, rt)
    182 	struct ifnet *ifp;
    183 	struct mbuf *m;
    184 	struct sockaddr *dst;
    185 	struct rtentry *rt;
    186 {
    187 	int s, isr;
    188 	struct ifqueue *ifq = 0;
    189 
    190 	if ((m->m_flags & M_PKTHDR) == 0)
    191 		panic("looutput: no header mbuf");
    192 #if NBPFILTER > 0
    193 	if (ifp->if_bpf && (ifp->if_flags & IFF_LOOPBACK)) {
    194 		/*
    195 		 * We need to prepend the address family as
    196 		 * a four byte field.  Cons up a dummy header
    197 		 * to pacify bpf.  This is safe because bpf
    198 		 * will only read from the mbuf (i.e., it won't
    199 		 * try to free it or keep a pointer to it).
    200 		 */
    201 		struct mbuf m0;
    202 		u_int32_t af = dst->sa_family;
    203 
    204 		m0.m_next = m;
    205 		m0.m_len = 4;
    206 		m0.m_data = (char *)&af;
    207 
    208 		bpf_mtap(ifp->if_bpf, &m0);
    209 	}
    210 #endif
    211 	m->m_pkthdr.rcvif = ifp;
    212 
    213 	if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
    214 		m_freem(m);
    215 		return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
    216 			rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
    217 	}
    218 
    219 #ifndef PULLDOWN_TEST
    220 	/*
    221 	 * KAME requires that the packet to be contiguous on the
    222 	 * mbuf.  We need to make that sure.
    223 	 * this kind of code should be avoided.
    224 	 * XXX other conditions to avoid running this part?
    225 	 */
    226 	if (m->m_len != m->m_pkthdr.len) {
    227 		struct mbuf *n = NULL;
    228 		int maxlen;
    229 
    230 		MGETHDR(n, M_DONTWAIT, MT_HEADER);
    231 		maxlen = MHLEN;
    232 		if (n)
    233 			M_COPY_PKTHDR(n, m);
    234 		if (n && m->m_pkthdr.len > maxlen) {
    235 			MCLGET(n, M_DONTWAIT);
    236 			maxlen = MCLBYTES;
    237 			if ((n->m_flags & M_EXT) == 0) {
    238 				m_free(n);
    239 				n = NULL;
    240 			}
    241 		}
    242 		if (!n) {
    243 			printf("looutput: mbuf allocation failed\n");
    244 			m_freem(m);
    245 			return ENOBUFS;
    246 		}
    247 
    248 		if (m->m_pkthdr.len <= maxlen) {
    249 			m_copydata(m, 0, m->m_pkthdr.len, mtod(n, caddr_t));
    250 			n->m_len = m->m_pkthdr.len;
    251 			n->m_next = NULL;
    252 			m_freem(m);
    253 		} else {
    254 			m_copydata(m, 0, maxlen, mtod(n, caddr_t));
    255 			m_adj(m, maxlen);
    256 			n->m_len = maxlen;
    257 			n->m_next = m;
    258 			m->m_flags &= ~M_PKTHDR;
    259 		}
    260 		m = n;
    261 	}
    262 #if 0
    263 	if (m && m->m_next != NULL) {
    264 		printf("loop: not contiguous...\n");
    265 		m_freem(m);
    266 		return ENOBUFS;
    267 	}
    268 #endif
    269 #endif
    270 
    271 	ifp->if_opackets++;
    272 	ifp->if_obytes += m->m_pkthdr.len;
    273 
    274 #ifdef ALTQ
    275 	/*
    276 	 * ALTQ on the loopback interface is just for debugging.  It's
    277 	 * used only for loopback interfaces, not for a simplex interface.
    278 	 */
    279 	if ((ALTQ_IS_ENABLED(&ifp->if_snd) || TBR_IS_ENABLED(&ifp->if_snd)) &&
    280 	    ifp->if_start == lostart) {
    281 		struct altq_pktattr pktattr;
    282 		int error;
    283 
    284 		/*
    285 		 * If the queueing discipline needs packet classification,
    286 		 * do it before prepending the link headers.
    287 		 */
    288 		IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family, &pktattr);
    289 
    290 		M_PREPEND(m, sizeof(uint32_t), M_DONTWAIT);
    291 		if (m == NULL)
    292 			return (ENOBUFS);
    293 		*(mtod(m, uint32_t *)) = dst->sa_family;
    294 
    295 		s = splnet();
    296 		IFQ_ENQUEUE(&ifp->if_snd, m, &pktattr, error);
    297 		(*ifp->if_start)(ifp);
    298 		splx(s);
    299 		return (error);
    300 	}
    301 #endif /* ALTQ */
    302 
    303 	switch (dst->sa_family) {
    304 
    305 #ifdef INET
    306 	case AF_INET:
    307 		ifq = &ipintrq;
    308 		isr = NETISR_IP;
    309 		break;
    310 #endif
    311 #ifdef INET6
    312 	case AF_INET6:
    313 		m->m_flags |= M_LOOP;
    314 		ifq = &ip6intrq;
    315 		isr = NETISR_IPV6;
    316 		break;
    317 #endif
    318 #ifdef NS
    319 	case AF_NS:
    320 		ifq = &nsintrq;
    321 		isr = NETISR_NS;
    322 		break;
    323 #endif
    324 #ifdef ISO
    325 	case AF_ISO:
    326 		ifq = &clnlintrq;
    327 		isr = NETISR_ISO;
    328 		break;
    329 #endif
    330 #ifdef IPX
    331 	case AF_IPX:
    332 		ifq = &ipxintrq;
    333 		isr = NETISR_IPX;
    334 		break;
    335 #endif
    336 #ifdef NETATALK
    337 	case AF_APPLETALK:
    338 	        ifq = &atintrq2;
    339 		isr = NETISR_ATALK;
    340 		break;
    341 #endif
    342 	default:
    343 		printf("%s: can't handle af%d\n", ifp->if_xname,
    344 		    dst->sa_family);
    345 		m_freem(m);
    346 		return (EAFNOSUPPORT);
    347 	}
    348 	s = splnet();
    349 	if (IF_QFULL(ifq)) {
    350 		IF_DROP(ifq);
    351 		m_freem(m);
    352 		splx(s);
    353 		return (ENOBUFS);
    354 	}
    355 	IF_ENQUEUE(ifq, m);
    356 	schednetisr(isr);
    357 	ifp->if_ipackets++;
    358 	ifp->if_ibytes += m->m_pkthdr.len;
    359 	splx(s);
    360 	return (0);
    361 }
    362 
    363 #ifdef ALTQ
    364 void
    365 lostart(struct ifnet *ifp)
    366 {
    367 	struct ifqueue *ifq;
    368 	struct mbuf *m;
    369 	uint32_t af;
    370 	int s, isr;
    371 
    372 	for (;;) {
    373 		IFQ_DEQUEUE(&ifp->if_snd, m);
    374 		if (m == NULL)
    375 			return;
    376 
    377 		af = *(mtod(m, uint32_t *));
    378 		m_adj(m, sizeof(uint32_t));
    379 
    380 		switch (af) {
    381 #ifdef INET
    382 		case AF_INET:
    383 			ifq = &ipintrq;
    384 			isr = NETISR_IP;
    385 			break;
    386 #endif
    387 #ifdef INET6
    388 		case AF_INET6:
    389 			m->m_flags |= M_LOOP;
    390 			ifq = &ip6intrq;
    391 			isr = NETISR_IPV6;
    392 			break;
    393 #endif
    394 #ifdef IPX
    395 		case AF_IPX:
    396 			ifq = &ipxintrq;
    397 			isr = NETISR_IPX;
    398 			break;
    399 #endif
    400 #ifdef NS
    401 		case AF_NS:
    402 			ifq = &nsintrq;
    403 			isr = NETISR_NS;
    404 			break;
    405 #endif
    406 #ifdef ISO
    407 		case AF_ISO:
    408 			ifq = &clnlintrq;
    409 			isr = NETISR_ISO;
    410 			break;
    411 #endif
    412 #ifdef NETATALK
    413 		case AF_APPLETALK:
    414 			ifq = &atintrq2;
    415 			isr = NETISR_ATALK;
    416 			break;
    417 #endif
    418 		default:
    419 			printf("%s: can't handle af%d\n", ifp->if_xname, af);
    420 			m_freem(m);
    421 			return;
    422 		}
    423 
    424 		s = splnet();
    425 		if (IF_QFULL(ifq)) {
    426 			IF_DROP(ifq);
    427 			splx(s);
    428 			m_freem(m);
    429 			return;
    430 		}
    431 		IF_ENQUEUE(ifq, m);
    432 		schednetisr(isr);
    433 		ifp->if_ipackets++;
    434 		ifp->if_ibytes += m->m_pkthdr.len;
    435 		splx(s);
    436 	}
    437 }
    438 #endif /* ALTQ */
    439 
    440 /* ARGSUSED */
    441 void
    442 lortrequest(cmd, rt, info)
    443 	int cmd;
    444 	struct rtentry *rt;
    445 	struct rt_addrinfo *info;
    446 {
    447 
    448 	if (rt)
    449 		rt->rt_rmx.rmx_mtu = LOMTU;
    450 }
    451 
    452 /*
    453  * Process an ioctl request.
    454  */
    455 /* ARGSUSED */
    456 int
    457 loioctl(ifp, cmd, data)
    458 	struct ifnet *ifp;
    459 	u_long cmd;
    460 	caddr_t data;
    461 {
    462 	struct ifaddr *ifa;
    463 	struct ifreq *ifr;
    464 	int error = 0;
    465 
    466 	switch (cmd) {
    467 
    468 	case SIOCSIFADDR:
    469 		ifp->if_flags |= IFF_UP;
    470 		ifa = (struct ifaddr *)data;
    471 		if (ifa != 0 /*&& ifa->ifa_addr->sa_family == AF_ISO*/)
    472 			ifa->ifa_rtrequest = lortrequest;
    473 		/*
    474 		 * Everything else is done at a higher level.
    475 		 */
    476 		break;
    477 
    478 	case SIOCADDMULTI:
    479 	case SIOCDELMULTI:
    480 		ifr = (struct ifreq *)data;
    481 		if (ifr == 0) {
    482 			error = EAFNOSUPPORT;		/* XXX */
    483 			break;
    484 		}
    485 		switch (ifr->ifr_addr.sa_family) {
    486 
    487 #ifdef INET
    488 		case AF_INET:
    489 			break;
    490 #endif
    491 #ifdef INET6
    492 		case AF_INET6:
    493 			break;
    494 #endif
    495 
    496 		default:
    497 			error = EAFNOSUPPORT;
    498 			break;
    499 		}
    500 		break;
    501 
    502 	default:
    503 		error = EINVAL;
    504 	}
    505 	return (error);
    506 }
    507