if_loop.c

Version: - FREEBSD - FREEBSD-13-STABLE - FREEBSD-13-0 - FREEBSD-12-STABLE - FREEBSD-12-0 - FREEBSD-11-STABLE - FREEBSD-11-0 - FREEBSD-10-STABLE - FREEBSD-10-0 - FREEBSD-9-STABLE - FREEBSD-9-0 - FREEBSD-8-STABLE - FREEBSD-8-0 - FREEBSD-7-STABLE - FREEBSD-7-0 - FREEBSD-6-STABLE - FREEBSD-6-0 - FREEBSD-5-STABLE - FREEBSD-5-0 - FREEBSD-4-STABLE - FREEBSD-3-STABLE - FREEBSD22 - l41 - OPENBSD - linux-2.6 - MK84 - PLAN9 - xnu-8792
SearchContext: - none - 3 - 10
    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/malloc.h>
   46 #include <sys/mbuf.h>
   47 #include <sys/module.h>
   48 #include <machine/bus.h>
   49 #include <sys/rman.h>
   50 #include <sys/socket.h>
   51 #include <sys/sockio.h>
   52 #include <sys/sysctl.h>
   53 
   54 #include <net/if.h>
   55 #include <net/if_clone.h>
   56 #include <net/if_types.h>
   57 #include <net/netisr.h>
   58 #include <net/route.h>
   59 #include <net/bpf.h>
   60 #include <net/bpfdesc.h>
   61 
   62 #ifdef  INET
   63 #include <netinet/in.h>
   64 #include <netinet/in_var.h>
   65 #endif
   66 
   67 #ifdef IPX
   68 #include <netipx/ipx.h>
   69 #include <netipx/ipx_if.h>
   70 #endif
   71 
   72 #ifdef INET6
   73 #ifndef INET
   74 #include <netinet/in.h>
   75 #endif
   76 #include <netinet6/in6_var.h>
   77 #include <netinet/ip6.h>
   78 #endif
   79 
   80 #ifdef NETATALK
   81 #include <netatalk/at.h>
   82 #include <netatalk/at_var.h>
   83 #endif
   84 
   85 #ifdef TINY_LOMTU
   86 #define LOMTU   (1024+512)
   87 #elif defined(LARGE_LOMTU)
   88 #define LOMTU   131072
   89 #else
   90 #define LOMTU   16384
   91 #endif
   92 
   93 #define LONAME  "lo"
   94 
   95 struct lo_softc {
   96         struct  ifnet *sc_ifp;
   97         LIST_ENTRY(lo_softc) sc_next;
   98 };
   99 
  100 int             loioctl(struct ifnet *, u_long, caddr_t);
  101 static void     lortrequest(int, struct rtentry *, struct rt_addrinfo *);
  102 int             looutput(struct ifnet *ifp, struct mbuf *m,
  103                     struct sockaddr *dst, struct rtentry *rt);
  104 static int      lo_clone_create(struct if_clone *, int, caddr_t);
  105 static void     lo_clone_destroy(struct ifnet *);
  106 
  107 struct ifnet *loif = NULL;                      /* Used externally */
  108 
  109 static MALLOC_DEFINE(M_LO, LONAME, "Loopback Interface");
  110 
  111 static struct mtx lo_mtx;
  112 static LIST_HEAD(lo_list, lo_softc) lo_list;
  113 
  114 IFC_SIMPLE_DECLARE(lo, 1);
  115 
  116 static void
  117 lo_clone_destroy(ifp)
  118         struct ifnet *ifp;
  119 {
  120         struct lo_softc *sc;
  121         
  122         sc = ifp->if_softc;
  123 
  124         /* XXX: destroying lo0 will lead to panics. */
  125         KASSERT(loif != ifp, ("%s: destroying lo0", __func__));
  126 
  127         mtx_lock(&lo_mtx);
  128         LIST_REMOVE(sc, sc_next);
  129         mtx_unlock(&lo_mtx);
  130         bpfdetach(ifp);
  131         if_detach(ifp);
  132         if_free(ifp);
  133         free(sc, M_LO);
  134 }
  135 
  136 static int
  137 lo_clone_create(ifc, unit, params)
  138         struct if_clone *ifc;
  139         int unit;
  140         caddr_t params;
  141 {
  142         struct ifnet *ifp;
  143         struct lo_softc *sc;
  144 
  145         MALLOC(sc, struct lo_softc *, sizeof(*sc), M_LO, M_WAITOK | M_ZERO);
  146         ifp = sc->sc_ifp = if_alloc(IFT_LOOP);
  147         if (ifp == NULL) {
  148                 free(sc, M_LO);
  149                 return (ENOSPC);
  150         }
  151 
  152         if_initname(ifp, ifc->ifc_name, unit);
  153         ifp->if_mtu = LOMTU;
  154         ifp->if_flags = IFF_LOOPBACK | IFF_MULTICAST;
  155         ifp->if_ioctl = loioctl;
  156         ifp->if_output = looutput;
  157         ifp->if_snd.ifq_maxlen = ifqmaxlen;
  158         ifp->if_softc = sc;
  159         if_attach(ifp);
  160         bpfattach(ifp, DLT_NULL, sizeof(u_int32_t));
  161         mtx_lock(&lo_mtx);
  162         LIST_INSERT_HEAD(&lo_list, sc, sc_next);
  163         mtx_unlock(&lo_mtx);
  164         if (loif == NULL)
  165                 loif = ifp;
  166 
  167         return (0);
  168 }
  169 
  170 static int
  171 loop_modevent(module_t mod, int type, void *data) 
  172 { 
  173         switch (type) { 
  174         case MOD_LOAD: 
  175                 mtx_init(&lo_mtx, "lo_mtx", NULL, MTX_DEF);
  176                 LIST_INIT(&lo_list);
  177                 if_clone_attach(&lo_cloner);
  178                 break; 
  179         case MOD_UNLOAD: 
  180                 printf("loop module unload - not possible for this module type\n"); 
  181                 return EINVAL; 
  182         default:
  183                 return EOPNOTSUPP;
  184         } 
  185         return 0; 
  186 } 
  187 
  188 static moduledata_t loop_mod = { 
  189         "loop", 
  190         loop_modevent, 
  191         0
  192 }; 
  193 
  194 DECLARE_MODULE(loop, loop_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY);
  195 
  196 int
  197 looutput(ifp, m, dst, rt)
  198         struct ifnet *ifp;
  199         register struct mbuf *m;
  200         struct sockaddr *dst;
  201         register struct rtentry *rt;
  202 {
  203         u_int32_t af;
  204 
  205         M_ASSERTPKTHDR(m); /* check if we have the packet header */
  206 
  207         if (rt && rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
  208                 m_freem(m);
  209                 return (rt->rt_flags & RTF_BLACKHOLE ? 0 :
  210                         rt->rt_flags & RTF_HOST ? EHOSTUNREACH : ENETUNREACH);
  211         }
  212 
  213         ifp->if_opackets++;
  214         ifp->if_obytes += m->m_pkthdr.len;
  215 
  216         /* BPF writes need to be handled specially. */
  217         if (dst->sa_family == AF_UNSPEC) {
  218                 bcopy(dst->sa_data, &af, sizeof(af));
  219                 dst->sa_family = af;
  220         }
  221 
  222 #if 1   /* XXX */
  223         switch (dst->sa_family) {
  224         case AF_INET:
  225         case AF_INET6:
  226         case AF_IPX:
  227         case AF_APPLETALK:
  228                 break;
  229         default:
  230                 printf("looutput: af=%d unexpected\n", dst->sa_family);
  231                 m_freem(m);
  232                 return (EAFNOSUPPORT);
  233         }
  234 #endif
  235         return(if_simloop(ifp, m, dst->sa_family, 0));
  236 }
  237 
  238 /*
  239  * if_simloop()
  240  *
  241  * This function is to support software emulation of hardware loopback,
  242  * i.e., for interfaces with the IFF_SIMPLEX attribute. Since they can't
  243  * hear their own broadcasts, we create a copy of the packet that we
  244  * would normally receive via a hardware loopback.
  245  *
  246  * This function expects the packet to include the media header of length hlen.
  247  */
  248 
  249 int
  250 if_simloop(ifp, m, af, hlen)
  251         struct ifnet *ifp;
  252         struct mbuf *m;
  253         int af;
  254         int hlen;
  255 {
  256         int isr;
  257 
  258         M_ASSERTPKTHDR(m);
  259         m_tag_delete_nonpersistent(m);
  260         m->m_pkthdr.rcvif = ifp;
  261 
  262         /*
  263          * Let BPF see incoming packet in the following manner:
  264          *  - Emulated packet loopback for a simplex interface 
  265          *    (net/if_ethersubr.c)
  266          *      -> passes it to ifp's BPF
  267          *  - IPv4/v6 multicast packet loopback (netinet(6)/ip(6)_output.c)
  268          *      -> not passes it to any BPF
  269          *  - Normal packet loopback from myself to myself (net/if_loop.c)
  270          *      -> passes to lo0's BPF (even in case of IPv6, where ifp!=lo0)
  271          */
  272         if (hlen > 0) {
  273                 if (bpf_peers_present(ifp->if_bpf)) {
  274                         bpf_mtap(ifp->if_bpf, m);
  275                 }
  276         } else {
  277                 if (bpf_peers_present(loif->if_bpf)) {
  278                         if ((m->m_flags & M_MCAST) == 0 || loif == ifp) {
  279                                 /* XXX beware sizeof(af) != 4 */
  280                                 u_int32_t af1 = af;     
  281 
  282                                 /*
  283                                  * We need to prepend the address family.
  284                                  */
  285                                 bpf_mtap2(loif->if_bpf, &af1, sizeof(af1), m);
  286                         }
  287                 }
  288         }
  289 
  290         /* Strip away media header */
  291         if (hlen > 0) {
  292                 m_adj(m, hlen);
  293 #ifndef __NO_STRICT_ALIGNMENT
  294                 /*
  295                  * Some archs do not like unaligned data, so
  296                  * we move data down in the first mbuf.
  297                  */
  298                 if (mtod(m, vm_offset_t) & 3) {
  299                         KASSERT(hlen >= 3, ("if_simloop: hlen too small"));
  300                         bcopy(m->m_data, 
  301                             (char *)(mtod(m, vm_offset_t) 
  302                                 - (mtod(m, vm_offset_t) & 3)),
  303                             m->m_len);
  304                         m->m_data -= (mtod(m,vm_offset_t) & 3);
  305                 }
  306 #endif
  307         }
  308 
  309         /* Deliver to upper layer protocol */
  310         switch (af) {
  311 #ifdef INET
  312         case AF_INET:
  313                 isr = NETISR_IP;
  314                 break;
  315 #endif
  316 #ifdef INET6
  317         case AF_INET6:
  318                 m->m_flags |= M_LOOP;
  319                 isr = NETISR_IPV6;
  320                 break;
  321 #endif
  322 #ifdef IPX
  323         case AF_IPX:
  324                 isr = NETISR_IPX;
  325                 break;
  326 #endif
  327 #ifdef NETATALK
  328         case AF_APPLETALK:
  329                 isr = NETISR_ATALK2;
  330                 break;
  331 #endif
  332         default:
  333                 printf("if_simloop: can't handle af=%d\n", af);
  334                 m_freem(m);
  335                 return (EAFNOSUPPORT);
  336         }
  337         ifp->if_ipackets++;
  338         ifp->if_ibytes += m->m_pkthdr.len;
  339         netisr_queue(isr, m);   /* mbuf is free'd on failure. */
  340         return (0);
  341 }
  342 
  343 /* ARGSUSED */
  344 static void
  345 lortrequest(cmd, rt, info)
  346         int cmd;
  347         struct rtentry *rt;
  348         struct rt_addrinfo *info;
  349 {
  350         RT_LOCK_ASSERT(rt);
  351         rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu;
  352 }
  353 
  354 /*
  355  * Process an ioctl request.
  356  */
  357 /* ARGSUSED */
  358 int
  359 loioctl(ifp, cmd, data)
  360         register struct ifnet *ifp;
  361         u_long cmd;
  362         caddr_t data;
  363 {
  364         register struct ifaddr *ifa;
  365         register struct ifreq *ifr = (struct ifreq *)data;
  366         register int error = 0;
  367 
  368         switch (cmd) {
  369 
  370         case SIOCSIFADDR:
  371                 ifp->if_flags |= IFF_UP;
  372                 ifp->if_drv_flags |= IFF_DRV_RUNNING;
  373                 ifa = (struct ifaddr *)data;
  374                 ifa->ifa_rtrequest = lortrequest;
  375                 /*
  376                  * Everything else is done at a higher level.
  377                  */
  378                 break;
  379 
  380         case SIOCADDMULTI:
  381         case SIOCDELMULTI:
  382                 if (ifr == 0) {
  383                         error = EAFNOSUPPORT;           /* XXX */
  384                         break;
  385                 }
  386                 switch (ifr->ifr_addr.sa_family) {
  387 
  388 #ifdef INET
  389                 case AF_INET:
  390                         break;
  391 #endif
  392 #ifdef INET6
  393                 case AF_INET6:
  394                         break;
  395 #endif
  396 
  397                 default:
  398                         error = EAFNOSUPPORT;
  399                         break;
  400                 }
  401                 break;
  402 
  403         case SIOCSIFMTU:
  404                 ifp->if_mtu = ifr->ifr_mtu;
  405                 break;
  406 
  407         case SIOCSIFFLAGS:
  408                 break;
  409 
  410         default:
  411                 error = EINVAL;
  412         }
  413         return (error);
  414 }
Cache object: 4e50db77d2914b57ee928c0039bd2ba6
[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]
This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.
FreeBSD/Linux Kernel Cross Reference sys/net/if_loop.c

FreeBSD/Linux Kernel Cross Reference
sys/net/if_loop.c
