sys/netproto/atalk/ddp_input.c

   1 /*
   2  * Copyright (c) 1990,1994 Regents of The University of Michigan.
   3  * All Rights Reserved.  See COPYRIGHT.
   4  *
   5  * $FreeBSD: src/sys/netatalk/ddp_input.c,v 1.12 2000/02/13 03:31:58 peter Exp $
   6  * $DragonFly: src/sys/netproto/atalk/ddp_input.c,v 1.15 2007/11/16 05:07:36 sephe Exp $
   7  */
   8
   9 #include <sys/param.h>
  10 #include <sys/systm.h>
  11 #include <sys/kernel.h>
  12 #include <sys/mbuf.h>
  13 #include <sys/socket.h>
  14 #include <sys/socketvar.h>
  15
  16 #include <sys/thread2.h>
  17 #include <sys/msgport2.h>
  18
  19 #include <net/if.h>
  20 #include <net/netisr.h>
  21 #include <net/route.h>
  22
  23 #include "at.h"
  24 #include "at_var.h"
  25 #include "ddp.h"
  26 #include "ddp_var.h"
  27 #include "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 const int atintrq1_present = 1, atintrq2_present = 1;
  35
  36 static void     ddp_input(struct mbuf *, struct ifnet *, struct elaphdr *, int);
  37
  38 /*
  39  * Could probably merge these two code segments a little better...
  40  */
  41 void
  42 at2intr(struct netmsg *msg)
  43 {
  44         struct mbuf *m = ((struct netmsg_packet *)msg)->nm_packet;
  45
  46         /*
  47          * Phase 2 packet handling
  48          */
  49         ddp_input(m, m->m_pkthdr.rcvif, NULL, 2);
  50         /* msg was embedded in the mbuf, do not reply! */
  51 }
  52
  53 void
  54 at1intr(struct netmsg *msg)
  55 {
  56         struct mbuf *m = ((struct netmsg_packet *)msg)->nm_packet;
  57         struct elaphdr *elhp, elh;
  58
  59         /*
  60          * Phase 1 packet handling
  61          */
  62         if (m->m_len < SZ_ELAPHDR && ((m = m_pullup(m, SZ_ELAPHDR)) == 0)) {
  63                 ddpstat.ddps_tooshort++;
  64                 goto out;
  65         }
  66
  67         /*
  68          * This seems a little dubious, but I don't know phase 1 so leave it.
  69          */
  70         elhp = mtod(m, struct elaphdr *);
  71         m_adj(m, SZ_ELAPHDR);
  72
  73         if (elhp->el_type == ELAP_DDPEXTEND) {
  74                 ddp_input(m, m->m_pkthdr.rcvif, NULL, 1);
  75         } else {
  76                 bcopy((caddr_t)elhp, (caddr_t)&elh, SZ_ELAPHDR);
  77                 ddp_input(m, m->m_pkthdr.rcvif, &elh, 1);
  78         }
  79 out:
  80         ;
  81         /* msg was embedded in the mbuf, do not reply! */
  82 }
  83
  84 static void
  85 ddp_input(struct mbuf *m, struct ifnet *ifp, struct elaphdr *elh, int phase)
  86 {
  87     struct sockaddr_at  from, to;
  88     struct ddpshdr      *dsh, ddps;
  89     struct at_ifaddr    *aa;
  90     struct ddpehdr      *deh = NULL, ddpe;
  91     struct ddpcb        *ddp;
  92     int                 dlen, mlen;
  93     u_short             cksum = 0;
  94
  95     bzero( (caddr_t)&from, sizeof( struct sockaddr_at ));
  96     bzero( (caddr_t)&to, sizeof( struct sockaddr_at ));
  97     if ( elh ) {
  98         /*
  99          * Extract the information in the short header.
 100          * netowrk information is defaulted to ATADDR_ANYNET
 101          * and node information comes from the elh info.
 102          * We must be phase 1.
 103          */
 104         ddpstat.ddps_short++;
 105
 106         if ( m->m_len < sizeof( struct ddpshdr ) &&
 107                 (( m = m_pullup( m, sizeof( struct ddpshdr ))) == 0 )) {
 108             ddpstat.ddps_tooshort++;
 109             return;
 110         }
 111
 112         dsh = mtod( m, struct ddpshdr *);
 113         bcopy( (caddr_t)dsh, (caddr_t)&ddps, sizeof( struct ddpshdr ));
 114         ddps.dsh_bytes = ntohl( ddps.dsh_bytes );
 115         dlen = ddps.dsh_len;
 116
 117         to.sat_addr.s_net = ATADDR_ANYNET;
 118         to.sat_addr.s_node = elh->el_dnode;
 119         to.sat_port = ddps.dsh_dport;
 120         from.sat_addr.s_net = ATADDR_ANYNET;
 121         from.sat_addr.s_node = elh->el_snode;
 122         from.sat_port = ddps.dsh_sport;
 123
 124         /*
 125          * Make sure that we point to the phase1 ifaddr info
 126          * and that it's valid for this packet.
 127          */
 128         for ( aa = at_ifaddr; aa; aa = aa->aa_next ) {
 129             if ( (aa->aa_ifp == ifp)
 130             && ( (aa->aa_flags & AFA_PHASE2) == 0)
 131             && ( (to.sat_addr.s_node == AA_SAT( aa )->sat_addr.s_node)
 132               || (to.sat_addr.s_node == ATADDR_BCAST))) {
 133                 break;
 134             }
 135         }
 136         /*
 137          * maybe we got a broadcast not meant for us.. ditch it.
 138          */
 139         if ( aa == NULL ) {
 140             m_freem( m );
 141             return;
 142         }
 143     } else {
 144         /*
 145          * There was no 'elh' passed on. This could still be
 146          * either phase1 or phase2.
 147          * We have a long header, but we may be running on a phase 1 net.
 148          * Extract out all the info regarding this packet's src & dst.
 149          */
 150         ddpstat.ddps_long++;
 151
 152         if ( m->m_len < sizeof( struct ddpehdr ) &&
 153                 (( m = m_pullup( m, sizeof( struct ddpehdr ))) == 0 )) {
 154             ddpstat.ddps_tooshort++;
 155             return;
 156         }
 157
 158         deh = mtod( m, struct ddpehdr *);
 159         bcopy( (caddr_t)deh, (caddr_t)&ddpe, sizeof( struct ddpehdr ));
 160         ddpe.deh_bytes = ntohl( ddpe.deh_bytes );
 161         dlen = ddpe.deh_len;
 162
 163         if (( cksum = ddpe.deh_sum ) == 0 ) {
 164             ddpstat.ddps_nosum++;
 165         }
 166
 167         from.sat_addr.s_net = ddpe.deh_snet;
 168         from.sat_addr.s_node = ddpe.deh_snode;
 169         from.sat_port = ddpe.deh_sport;
 170         to.sat_addr.s_net = ddpe.deh_dnet;
 171         to.sat_addr.s_node = ddpe.deh_dnode;
 172         to.sat_port = ddpe.deh_dport;
 173
 174         if ( to.sat_addr.s_net == ATADDR_ANYNET ) {
 175             /*
 176              * The TO address doesn't specify a net,
 177              * So by definition it's for this net.
 178              * Try find ifaddr info with the right phase,
 179              * the right interface, and either to our node, a broadcast,
 180              * or looped back (though that SHOULD be covered in the other
 181              * cases).
 182              *
 183              * XXX If we have multiple interfaces, then the first with
 184              * this node number will match (which may NOT be what we want,
 185              * but it's probably safe in 99.999% of cases.
 186              */
 187             for ( aa = at_ifaddr; aa; aa = aa->aa_next ) {
 188                 if ( phase == 1 && ( aa->aa_flags & AFA_PHASE2 )) {
 189                     continue;
 190                 }
 191                 if ( phase == 2 && ( aa->aa_flags & AFA_PHASE2 ) == 0 ) {
 192                     continue;
 193                 }
 194                 if ( (aa->aa_ifp == ifp)
 195                 && ( (to.sat_addr.s_node == AA_SAT( aa )->sat_addr.s_node)
 196                   || (to.sat_addr.s_node == ATADDR_BCAST)
 197                   || (ifp->if_flags & IFF_LOOPBACK))) {
 198                     break;
 199                 }
 200             }
 201         } else {
 202             /*
 203              * A destination network was given. We just try to find
 204              * which ifaddr info matches it.
 205              */
 206             for ( aa = at_ifaddr; aa; aa = aa->aa_next ) {
 207                 /*
 208                  * This is a kludge. Accept packets that are
 209                  * for any router on a local netrange.
 210                  */
 211                 if ( to.sat_addr.s_net == aa->aa_firstnet &&
 212                         to.sat_addr.s_node == 0 ) {
 213                     break;
 214                 }
 215                 /*
 216                  * Don't use ifaddr info for which we are totally outside the
 217                  * netrange, and it's not a startup packet.
 218                  * Startup packets are always implicitly allowed on to
 219                  * the next test.
 220                  */
 221                 if ((( ntohs( to.sat_addr.s_net ) < ntohs( aa->aa_firstnet ))
 222                     || (ntohs( to.sat_addr.s_net ) > ntohs( aa->aa_lastnet )))
 223                  && (( ntohs( to.sat_addr.s_net ) < 0xff00)
 224                     || (ntohs( to.sat_addr.s_net ) > 0xfffe ))) {
 225                     continue;
 226                 }
 227
 228                 /*
 229                  * Don't record a match either if we just don't have a match
 230                  * in the node address. This can have if the interface
 231                  * is in promiscuous mode for example.
 232                  */
 233                 if (( to.sat_addr.s_node != AA_SAT( aa )->sat_addr.s_node)
 234                 && (to.sat_addr.s_node != ATADDR_BCAST) ) {
 235                     continue;
 236                 }
 237                 break;
 238             }
 239         }
 240     }
 241
 242     /*
 243      * Adjust the length, removing any padding that may have been added
 244      * at a link layer.  We do this before we attempt to forward a packet,
 245      * possibly on a different media.
 246      */
 247     mlen = m->m_pkthdr.len;
 248     if ( mlen < dlen ) {
 249         ddpstat.ddps_toosmall++;
 250         m_freem( m );
 251         return;
 252     }
 253     if ( mlen > dlen ) {
 254         m_adj( m, dlen - mlen );
 255     }
 256
 257     /*
 258      * If it aint for a net on any of our interfaces,
 259      * or it IS for a net on a different interface than it came in on,
 260      * (and it is not looped back) then consider if we should forward it.
 261      * As we are not really a router this is a bit cheeky, but it may be
 262      * useful some day.
 263      */
 264     if ( (aa == NULL)
 265     || ( (to.sat_addr.s_node == ATADDR_BCAST)
 266       && (aa->aa_ifp != ifp)
 267       && (( ifp->if_flags & IFF_LOOPBACK ) == 0 ))) {
 268         /*
 269          * If we've explicitly disabled it, don't route anything
 270          */
 271         if ( ddp_forward == 0 ) {
 272             m_freem( m );
 273             return;
 274         }
 275         /*
 276          * If the cached forwarding route is still valid, use it.
 277          */
 278         if ( forwro.ro_rt
 279         && ( satosat(&forwro.ro_dst)->sat_addr.s_net != to.sat_addr.s_net
 280           || satosat(&forwro.ro_dst)->sat_addr.s_node != to.sat_addr.s_node )) {
 281             RTFREE( forwro.ro_rt );
 282             forwro.ro_rt = NULL;
 283         }
 284
 285         /*
 286          * If we don't have a cached one (any more) or it's useless,
 287          * Then get a new route.
 288          * XXX this could cause a 'route leak'. check this!
 289          */
 290         if ( forwro.ro_rt == NULL
 291         || forwro.ro_rt->rt_ifp == NULL ) {
 292             forwro.ro_dst.sa_len = sizeof( struct sockaddr_at );
 293             forwro.ro_dst.sa_family = AF_APPLETALK;
 294             satosat(&forwro.ro_dst)->sat_addr.s_net = to.sat_addr.s_net;
 295             satosat(&forwro.ro_dst)->sat_addr.s_node = to.sat_addr.s_node;
 296             rtalloc(&forwro);
 297         }
 298
 299         /*
 300          * If it's not going to get there on this hop, and it's
 301          * already done too many hops, then throw it away.
 302          */
 303         if ( (to.sat_addr.s_net != satosat( &forwro.ro_dst )->sat_addr.s_net)
 304         && (ddpe.deh_hops == DDP_MAXHOPS) ) {
 305             m_freem( m );
 306             return;
 307         }
 308
 309         /*
 310          * A ddp router might use the same interface
 311          * to forward the packet, which this would not effect.
 312          * Don't allow packets to cross from one interface to another however.
 313          */
 314         if ( ddp_firewall
 315         && ( (forwro.ro_rt == NULL)
 316           || (forwro.ro_rt->rt_ifp != ifp))) {
 317             m_freem( m );
 318             return;
 319         }
 320
 321         /*
 322          * Adjust the header.
 323          * If it was a short header then it would have not gotten here,
 324          * so we can assume there is room to drop the header in.
 325          * XXX what about promiscuous mode, etc...
 326          */
 327         ddpe.deh_hops++;
 328         ddpe.deh_bytes = htonl( ddpe.deh_bytes );
 329         bcopy( (caddr_t)&ddpe, (caddr_t)deh, sizeof( u_short )); /* XXX deh? */
 330         if ( ddp_route( m, &forwro )) {
 331             ddpstat.ddps_cantforward++;
 332         } else {
 333             ddpstat.ddps_forward++;
 334         }
 335         return;
 336     }
 337
 338     /*
 339      * It was for us, and we have an ifaddr to use with it.
 340      */
 341     from.sat_len = sizeof( struct sockaddr_at );
 342     from.sat_family = AF_APPLETALK;
 343
 344     /*
 345      * We are no longer interested in the link layer.
 346      * so cut it off.
 347      */
 348     if ( elh ) {
 349         m_adj( m, sizeof( struct ddpshdr ));
 350     } else {
 351         if ( ddp_cksum && cksum && cksum != at_cksum( m, sizeof( int ))) {
 352             ddpstat.ddps_badsum++;
 353             m_freem( m );
 354             return;
 355         }
 356         m_adj( m, sizeof( struct ddpehdr ));
 357     }
 358
 359     /*
 360      * Search for ddp protocol control blocks that match these
 361      * addresses.
 362      */
 363     if (( ddp = ddp_search( &from, &to, aa )) == NULL ) {
 364         m_freem( m );
 365         return;
 366     }
 367
 368     /*
 369      * If we found one, deliver th epacket to the socket
 370      */
 371     if (ssb_appendaddr( &ddp->ddp_socket->so_rcv, (struct sockaddr *)&from,
 372             m, NULL ) == 0 ) {
 373         /*
 374          * If the socket is full (or similar error) dump the packet.
 375          */
 376         ddpstat.ddps_nosockspace++;
 377         m_freem( m );
 378         return;
 379     }
 380     /*
 381      * And wake up whatever might be waiting for it
 382      */
 383     sorwakeup( ddp->ddp_socket );
 384 }
 385
 386 #if 0
 387 /* As if we haven't got enough of this sort of think floating
 388 around the kernel :) */
 389
 390 #define BPXLEN  48
 391 #define BPALEN  16
 392 #include <ctype.h>
 393 char    hexdig[] = "0123456789ABCDEF";
 394
 395 static void
 396 bprint(char *data, int len)
 397 {
 398     char        xout[ BPXLEN ], aout[ BPALEN ];
 399     int         i = 0;
 400
 401     bzero( xout, BPXLEN );
 402     bzero( aout, BPALEN );
 403
 404     for ( ;; ) {
 405         if ( len < 1 ) {
 406             if ( i != 0 ) {
 407                 kprintf( "%s\t%s\n", xout, aout );
 408             }
 409             kprintf( "%s\n", "(end)" );
 410             break;
 411         }
 412
 413         xout[ (i*3) ] = hexdig[ ( *data & 0xf0 ) >> 4 ];
 414         xout[ (i*3) + 1 ] = hexdig[ *data & 0x0f ];
 415
 416         if ( (u_char)*data < 0x7f && (u_char)*data > 0x20 ) {
 417             aout[ i ] = *data;
 418         } else {
 419             aout[ i ] = '.';
 420         }
 421
 422         xout[ (i*3) + 2 ] = ' ';
 423
 424         i++;
 425         len--;
 426         data++;
 427
 428         if ( i > BPALEN - 2 ) {
 429             kprintf( "%s\t%s\n", xout, aout );
 430             bzero( xout, BPXLEN );
 431             bzero( aout, BPALEN );
 432             i = 0;
 433             continue;
 434         }
 435     }
 436 }
 437
 438 static void
 439 m_printm(struct mbuf *m)
 440 {
 441     for (; m; m = m->m_next ) {
 442         bprint( mtod( m, char * ), m->m_len );
 443     }
 444 }
 445 #endif