ddp_input.c

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    1 /*
    2  * Copyright (c) 1990,1994 Regents of The University of Michigan.
    3  * All Rights Reserved.  See COPYRIGHT.
    4  *
    5  * $FreeBSD: releng/5.1/sys/netatalk/ddp_input.c 111888 2003-03-04 23:19:55Z jlemon $
    6  */
    7 
    8 #include "opt_mac.h"
    9 
   10 #include <sys/param.h>
   11 #include <sys/kernel.h>
   12 #include <sys/lock.h>
   13 #include <sys/mac.h>
   14 #include <sys/mbuf.h>
   15 #include <sys/signalvar.h>
   16 #include <sys/socket.h>
   17 #include <sys/socketvar.h>
   18 #include <sys/sx.h>
   19 #include <sys/systm.h>
   20 #include <net/if.h>
   21 #include <net/route.h>
   22 
   23 #include <netatalk/at.h>
   24 #include <netatalk/at_var.h>
   25 #include <netatalk/ddp.h>
   26 #include <netatalk/ddp_var.h>
   27 #include <netatalk/at_extern.h>
   28 
   29 static volatile int     ddp_forward = 1;
   30 static volatile int     ddp_firewall = 0;
   31 static struct ddpstat   ddpstat;
   32 static struct route     forwro;
   33 
   34 static void     ddp_input(struct mbuf *, struct ifnet *, struct elaphdr *, int);
   35 
   36 /*
   37  * Could probably merge these two code segments a little better...
   38  */
   39 void
   40 at2intr(struct mbuf *m)
   41 {
   42 
   43         /*
   44          * Phase 2 packet handling 
   45          */
   46         ddp_input(m, m->m_pkthdr.rcvif, NULL, 2);
   47         return;
   48 }
   49 
   50 void
   51 at1intr(struct mbuf *m)
   52 {
   53         struct elaphdr *elhp, elh;
   54 
   55         /*
   56          * Phase 1 packet handling 
   57          */
   58         if (m->m_len < SZ_ELAPHDR && ((m = m_pullup(m, SZ_ELAPHDR)) == 0)) {
   59                 ddpstat.ddps_tooshort++;
   60                 return;
   61         }
   62 
   63         /*
   64          * This seems a little dubious, but I don't know phase 1 so leave it.
   65          */
   66         elhp = mtod(m, struct elaphdr *);
   67         m_adj(m, SZ_ELAPHDR);
   68 
   69         if (elhp->el_type == ELAP_DDPEXTEND) {
   70                 ddp_input(m, m->m_pkthdr.rcvif, NULL, 1);
   71         } else {
   72                 bcopy((caddr_t)elhp, (caddr_t)&elh, SZ_ELAPHDR);
   73                 ddp_input(m, m->m_pkthdr.rcvif, &elh, 1);
   74         }
   75         return;
   76 }
   77 
   78 static void
   79 ddp_input( m, ifp, elh, phase )
   80     struct mbuf         *m;
   81     struct ifnet        *ifp;
   82     struct elaphdr      *elh;
   83     int                 phase;
   84 {
   85     struct sockaddr_at  from, to;
   86     struct ddpshdr      *dsh, ddps;
   87     struct at_ifaddr    *aa;
   88     struct ddpehdr      *deh = NULL, ddpe;
   89     struct ddpcb        *ddp;
   90     int                 dlen, mlen;
   91     u_short             cksum = 0;
   92 
   93     bzero( (caddr_t)&from, sizeof( struct sockaddr_at ));
   94     bzero( (caddr_t)&to, sizeof( struct sockaddr_at ));
   95     if ( elh ) {
   96         /*
   97          * Extract the information in the short header.
   98          * netowrk information is defaulted to ATADDR_ANYNET
   99          * and node information comes from the elh info.
  100          * We must be phase 1.
  101          */
  102         ddpstat.ddps_short++;
  103 
  104         if ( m->m_len < sizeof( struct ddpshdr ) &&
  105                 (( m = m_pullup( m, sizeof( struct ddpshdr ))) == 0 )) {
  106             ddpstat.ddps_tooshort++;
  107             return;
  108         }
  109 
  110         dsh = mtod( m, struct ddpshdr *);
  111         bcopy( (caddr_t)dsh, (caddr_t)&ddps, sizeof( struct ddpshdr ));
  112         ddps.dsh_bytes = ntohl( ddps.dsh_bytes );
  113         dlen = ddps.dsh_len;
  114 
  115         to.sat_addr.s_net = ATADDR_ANYNET;
  116         to.sat_addr.s_node = elh->el_dnode;
  117         to.sat_port = ddps.dsh_dport;
  118         from.sat_addr.s_net = ATADDR_ANYNET;
  119         from.sat_addr.s_node = elh->el_snode;
  120         from.sat_port = ddps.dsh_sport;
  121 
  122         /* 
  123          * Make sure that we point to the phase1 ifaddr info 
  124          * and that it's valid for this packet.
  125          */
  126         for ( aa = at_ifaddr; aa; aa = aa->aa_next ) {
  127             if ( (aa->aa_ifp == ifp)
  128             && ( (aa->aa_flags & AFA_PHASE2) == 0)
  129             && ( (to.sat_addr.s_node == AA_SAT( aa )->sat_addr.s_node)
  130               || (to.sat_addr.s_node == ATADDR_BCAST))) {
  131                 break;
  132             }
  133         }
  134         /* 
  135          * maybe we got a broadcast not meant for us.. ditch it.
  136          */
  137         if ( aa == NULL ) {
  138             m_freem( m );
  139             return;
  140         }
  141     } else {
  142         /*
  143          * There was no 'elh' passed on. This could still be
  144          * either phase1 or phase2.
  145          * We have a long header, but we may be running on a phase 1 net.
  146          * Extract out all the info regarding this packet's src & dst.
  147          */
  148         ddpstat.ddps_long++;
  149 
  150         if ( m->m_len < sizeof( struct ddpehdr ) &&
  151                 (( m = m_pullup( m, sizeof( struct ddpehdr ))) == 0 )) {
  152             ddpstat.ddps_tooshort++;
  153             return;
  154         }
  155 
  156         deh = mtod( m, struct ddpehdr *);
  157         bcopy( (caddr_t)deh, (caddr_t)&ddpe, sizeof( struct ddpehdr ));
  158         ddpe.deh_bytes = ntohl( ddpe.deh_bytes );
  159         dlen = ddpe.deh_len;
  160 
  161         if (( cksum = ddpe.deh_sum ) == 0 ) {
  162             ddpstat.ddps_nosum++;
  163         }
  164 
  165         from.sat_addr.s_net = ddpe.deh_snet;
  166         from.sat_addr.s_node = ddpe.deh_snode;
  167         from.sat_port = ddpe.deh_sport;
  168         to.sat_addr.s_net = ddpe.deh_dnet;
  169         to.sat_addr.s_node = ddpe.deh_dnode;
  170         to.sat_port = ddpe.deh_dport;
  171 
  172         if ( to.sat_addr.s_net == ATADDR_ANYNET ) {
  173             /*
  174              * The TO address doesn't specify a net,
  175              * So by definition it's for this net.
  176              * Try find ifaddr info with the right phase, 
  177              * the right interface, and either to our node, a broadcast,
  178              * or looped back (though that SHOULD be covered in the other
  179              * cases).
  180              *
  181              * XXX If we have multiple interfaces, then the first with
  182              * this node number will match (which may NOT be what we want,
  183              * but it's probably safe in 99.999% of cases.
  184              */
  185             for ( aa = at_ifaddr; aa; aa = aa->aa_next ) {
  186                 if ( phase == 1 && ( aa->aa_flags & AFA_PHASE2 )) {
  187                     continue;
  188                 }
  189                 if ( phase == 2 && ( aa->aa_flags & AFA_PHASE2 ) == 0 ) {
  190                     continue;
  191                 }
  192                 if ( (aa->aa_ifp == ifp)
  193                 && ( (to.sat_addr.s_node == AA_SAT( aa )->sat_addr.s_node)
  194                   || (to.sat_addr.s_node == ATADDR_BCAST)
  195                   || (ifp->if_flags & IFF_LOOPBACK))) {
  196                     break;
  197                 }
  198             }
  199         } else {
  200             /* 
  201              * A destination network was given. We just try to find 
  202              * which ifaddr info matches it.
  203              */
  204             for ( aa = at_ifaddr; aa; aa = aa->aa_next ) {
  205                 /*
  206                  * This is a kludge. Accept packets that are
  207                  * for any router on a local netrange.
  208                  */
  209                 if ( to.sat_addr.s_net == aa->aa_firstnet &&
  210                         to.sat_addr.s_node == 0 ) {
  211                     break;
  212                 }
  213                 /*
  214                  * Don't use ifaddr info for which we are totally outside the
  215                  * netrange, and it's not a startup packet.
  216                  * Startup packets are always implicitly allowed on to
  217                  * the next test.
  218                  */
  219                 if ((( ntohs( to.sat_addr.s_net ) < ntohs( aa->aa_firstnet ))
  220                     || (ntohs( to.sat_addr.s_net ) > ntohs( aa->aa_lastnet )))
  221                  && (( ntohs( to.sat_addr.s_net ) < 0xff00)
  222                     || (ntohs( to.sat_addr.s_net ) > 0xfffe ))) {
  223                     continue;
  224                 }
  225 
  226                 /*
  227                  * Don't record a match either if we just don't have a match
  228                  * in the node address. This can have if the interface
  229                  * is in promiscuous mode for example.
  230                  */
  231                 if (( to.sat_addr.s_node != AA_SAT( aa )->sat_addr.s_node)
  232                 && (to.sat_addr.s_node != ATADDR_BCAST) ) {
  233                     continue;
  234                 }
  235                 break;
  236             }
  237         }
  238     }
  239 
  240     /*
  241      * Adjust the length, removing any padding that may have been added
  242      * at a link layer.  We do this before we attempt to forward a packet,
  243      * possibly on a different media.
  244      */
  245     mlen = m->m_pkthdr.len;
  246     if ( mlen < dlen ) {
  247         ddpstat.ddps_toosmall++;
  248         m_freem( m );
  249         return;
  250     }
  251     if ( mlen > dlen ) {
  252         m_adj( m, dlen - mlen );
  253     }
  254 
  255     /*
  256      * If it aint for a net on any of our interfaces,
  257      * or it IS for a net on a different interface than it came in on,
  258      * (and it is not looped back) then consider if we should forward it.
  259      * As we are not really a router this is a bit cheeky, but it may be
  260      * useful some day.
  261      */
  262     if ( (aa == NULL)
  263     || ( (to.sat_addr.s_node == ATADDR_BCAST)
  264       && (aa->aa_ifp != ifp)
  265       && (( ifp->if_flags & IFF_LOOPBACK ) == 0 ))) {
  266         /* 
  267          * If we've explicitly disabled it, don't route anything
  268          */
  269         if ( ddp_forward == 0 ) {
  270             m_freem( m );
  271             return;
  272         }
  273         /* 
  274          * If the cached forwarding route is still valid, use it.
  275          */
  276         if ( forwro.ro_rt
  277         && ( satosat(&forwro.ro_dst)->sat_addr.s_net != to.sat_addr.s_net
  278           || satosat(&forwro.ro_dst)->sat_addr.s_node != to.sat_addr.s_node )) {
  279             RTFREE( forwro.ro_rt );
  280             forwro.ro_rt = (struct rtentry *)0;
  281         }
  282 
  283         /*
  284          * If we don't have a cached one (any more) or it's useless,
  285          * Then get a new route.
  286          * XXX this could cause a 'route leak'. check this!
  287          */
  288         if ( forwro.ro_rt == (struct rtentry *)0
  289         || forwro.ro_rt->rt_ifp == (struct ifnet *)0 ) {
  290             forwro.ro_dst.sa_len = sizeof( struct sockaddr_at );
  291             forwro.ro_dst.sa_family = AF_APPLETALK;
  292             satosat(&forwro.ro_dst)->sat_addr.s_net = to.sat_addr.s_net;
  293             satosat(&forwro.ro_dst)->sat_addr.s_node = to.sat_addr.s_node;
  294             rtalloc(&forwro);
  295         }
  296 
  297         /* 
  298          * If it's not going to get there on this hop, and it's
  299          * already done too many hops, then throw it away.
  300          */
  301         if ( (to.sat_addr.s_net != satosat( &forwro.ro_dst )->sat_addr.s_net)
  302         && (ddpe.deh_hops == DDP_MAXHOPS) ) {
  303             m_freem( m );
  304             return;
  305         }
  306 
  307         /*
  308          * A ddp router might use the same interface
  309          * to forward the packet, which this would not effect.
  310          * Don't allow packets to cross from one interface to another however.
  311          */
  312         if ( ddp_firewall
  313         && ( (forwro.ro_rt == NULL)
  314           || (forwro.ro_rt->rt_ifp != ifp))) {
  315             m_freem( m );
  316             return;
  317         }
  318 
  319         /*
  320          * Adjust the header.
  321          * If it was a short header then it would have not gotten here,
  322          * so we can assume there is room to drop the header in.
  323          * XXX what about promiscuous mode, etc...
  324          */
  325         ddpe.deh_hops++;
  326         ddpe.deh_bytes = htonl( ddpe.deh_bytes );
  327         bcopy( (caddr_t)&ddpe, (caddr_t)deh, sizeof( u_short )); /* XXX deh? */
  328         if ( ddp_route( m, &forwro )) {
  329             ddpstat.ddps_cantforward++;
  330         } else {
  331             ddpstat.ddps_forward++;
  332         }
  333         return;
  334     }
  335 
  336     /*
  337      * It was for us, and we have an ifaddr to use with it.
  338      */
  339     from.sat_len = sizeof( struct sockaddr_at );
  340     from.sat_family = AF_APPLETALK;
  341 
  342     /* 
  343      * We are no longer interested in the link layer.
  344      * so cut it off.
  345      */
  346     if ( elh ) {
  347         m_adj( m, sizeof( struct ddpshdr ));
  348     } else {
  349         if ( ddp_cksum && cksum && cksum != at_cksum( m, sizeof( int ))) {
  350             ddpstat.ddps_badsum++;
  351             m_freem( m );
  352             return;
  353         }
  354         m_adj( m, sizeof( struct ddpehdr ));
  355     }
  356 
  357     /* 
  358      * Search for ddp protocol control blocks that match these
  359      * addresses. 
  360      */
  361     if (( ddp = ddp_search( &from, &to, aa )) == NULL ) {
  362         m_freem( m );
  363         return;
  364     }
  365 
  366 #ifdef MAC
  367     if (mac_check_socket_deliver(ddp->ddp_socket, m) != 0) {
  368         m_freem( m );
  369         return;
  370     }
  371 #endif
  372 
  373     /* 
  374      * If we found one, deliver th epacket to the socket
  375      */
  376     if ( sbappendaddr( &ddp->ddp_socket->so_rcv, (struct sockaddr *)&from,
  377             m, (struct mbuf *)0 ) == 0 ) {
  378         /* 
  379          * If the socket is full (or similar error) dump the packet.
  380          */
  381         ddpstat.ddps_nosockspace++;
  382         m_freem( m );
  383         return;
  384     }
  385     /*
  386      * And wake up whatever might be waiting for it
  387      */
  388     sorwakeup( ddp->ddp_socket );
  389 }
  390 
  391 #if 0
  392 /* As if we haven't got enough of this sort of think floating
  393 around the kernel :) */
  394 
  395 #define BPXLEN  48
  396 #define BPALEN  16
  397 #include <ctype.h>
  398 char    hexdig[] = "0123456789ABCDEF";
  399 
  400 static void
  401 bprint( char *data, int len )
  402 {
  403     char        xout[ BPXLEN ], aout[ BPALEN ];
  404     int         i = 0;
  405 
  406     bzero( xout, BPXLEN );
  407     bzero( aout, BPALEN );
  408 
  409     for ( ;; ) {
  410         if ( len < 1 ) {
  411             if ( i != 0 ) {
  412                 printf( "%s\t%s\n", xout, aout );
  413             }
  414             printf( "%s\n", "(end)" );
  415             break;
  416         }
  417 
  418         xout[ (i*3) ] = hexdig[ ( *data & 0xf0 ) >> 4 ];
  419         xout[ (i*3) + 1 ] = hexdig[ *data & 0x0f ];
  420 
  421         if ( (u_char)*data < 0x7f && (u_char)*data > 0x20 ) {
  422             aout[ i ] = *data;
  423         } else {
  424             aout[ i ] = '.';
  425         }
  426 
  427         xout[ (i*3) + 2 ] = ' ';
  428 
  429         i++;
  430         len--;
  431         data++;
  432 
  433         if ( i > BPALEN - 2 ) {
  434             printf( "%s\t%s\n", xout, aout );
  435             bzero( xout, BPXLEN );
  436             bzero( aout, BPALEN );
  437             i = 0;
  438             continue;
  439         }
  440     }
  441 }
  442 
  443 static void
  444 m_printm( struct mbuf *m )
  445 {
  446     for (; m; m = m->m_next ) {
  447         bprint( mtod( m, char * ), m->m_len );
  448     }
  449 }
  450 #endif
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FreeBSD/Linux Kernel Cross Reference sys/netatalk/ddp_input.c

FreeBSD/Linux Kernel Cross Reference
sys/netatalk/ddp_input.c
