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 1.14 2007/05/23 08:57:06 dillon 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 #include <net/intrq.h>
  23
  24 #include "at.h"
  25 #include "at_var.h"
  26 #include "ddp.h"
  27 #include "ddp_var.h"
  28 #include "at_extern.h"
  29
  30 static volatile int     ddp_forward = 1;
  31 static volatile int     ddp_firewall = 0;
  32 static struct ddpstat   ddpstat;
  33 static struct route     forwro;
  34
  35 const int atintrq1_present = 1, atintrq2_present = 1;
  36
  37 static void     ddp_input(struct mbuf *, struct ifnet *, struct elaphdr *, int);
  38
  39 /*
  40  * Could probably merge these two code segments a little better...
  41  */
  42 void
  43 at2intr(struct netmsg *msg)
  44 {
  45         struct mbuf *m = ((struct netmsg_packet *)msg)->nm_packet;
  46
  47         /*
  48          * Phase 2 packet handling
  49          */
  50         ddp_input(m, m->m_pkthdr.rcvif, NULL, 2);
  51         /* msg was embedded in the mbuf, do not reply! */
  52 }
  53
  54 void
  55 at1intr(struct netmsg *msg)
  56 {
  57         struct mbuf *m = ((struct netmsg_packet *)msg)->nm_packet;
  58         struct elaphdr *elhp, elh;
  59
  60         /*
  61          * Phase 1 packet handling
  62          */
  63         if (m->m_len < SZ_ELAPHDR && ((m = m_pullup(m, SZ_ELAPHDR)) == 0)) {
  64                 ddpstat.ddps_tooshort++;
  65                 goto out;
  66         }
  67
  68         /*
  69          * This seems a little dubious, but I don't know phase 1 so leave it.
  70          */
  71         elhp = mtod(m, struct elaphdr *);
  72         m_adj(m, SZ_ELAPHDR);
  73
  74         if (elhp->el_type == ELAP_DDPEXTEND) {
  75                 ddp_input(m, m->m_pkthdr.rcvif, NULL, 1);
  76         } else {
  77                 bcopy((caddr_t)elhp, (caddr_t)&elh, SZ_ELAPHDR);
  78                 ddp_input(m, m->m_pkthdr.rcvif, &elh, 1);
  79         }
  80 out:
  81         ;
  82         /* msg was embedded in the mbuf, do not reply! */
  83 }
  84
  85 static void
  86 ddp_input(struct mbuf *m, struct ifnet *ifp, struct elaphdr *elh, int phase)
  87 {
  88     struct sockaddr_at  from, to;
  89     struct ddpshdr      *dsh, ddps;
  90     struct at_ifaddr    *aa;
  91     struct ddpehdr      *deh = NULL, ddpe;
  92     struct ddpcb        *ddp;
  93     int                 dlen, mlen;
  94     u_short             cksum = 0;
  95
  96     bzero( (caddr_t)&from, sizeof( struct sockaddr_at ));
  97     bzero( (caddr_t)&to, sizeof( struct sockaddr_at ));
  98     if ( elh ) {
  99         /*
 100          * Extract the information in the short header.
 101          * netowrk information is defaulted to ATADDR_ANYNET
 102          * and node information comes from the elh info.
 103          * We must be phase 1.
 104          */
 105         ddpstat.ddps_short++;
 106
 107         if ( m->m_len < sizeof( struct ddpshdr ) &&
 108                 (( m = m_pullup( m, sizeof( struct ddpshdr ))) == 0 )) {
 109             ddpstat.ddps_tooshort++;
 110             return;
 111         }
 112
 113         dsh = mtod( m, struct ddpshdr *);
 114         bcopy( (caddr_t)dsh, (caddr_t)&ddps, sizeof( struct ddpshdr ));
 115         ddps.dsh_bytes = ntohl( ddps.dsh_bytes );
 116         dlen = ddps.dsh_len;
 117
 118         to.sat_addr.s_net = ATADDR_ANYNET;
 119         to.sat_addr.s_node = elh->el_dnode;
 120         to.sat_port = ddps.dsh_dport;
 121         from.sat_addr.s_net = ATADDR_ANYNET;
 122         from.sat_addr.s_node = elh->el_snode;
 123         from.sat_port = ddps.dsh_sport;
 124
 125         /*
 126          * Make sure that we point to the phase1 ifaddr info
 127          * and that it's valid for this packet.
 128          */
 129         for ( aa = at_ifaddr; aa; aa = aa->aa_next ) {
 130             if ( (aa->aa_ifp == ifp)
 131             && ( (aa->aa_flags & AFA_PHASE2) == 0)
 132             && ( (to.sat_addr.s_node == AA_SAT( aa )->sat_addr.s_node)
 133               || (to.sat_addr.s_node == ATADDR_BCAST))) {
 134                 break;
 135             }
 136         }
 137         /*
 138          * maybe we got a broadcast not meant for us.. ditch it.
 139          */
 140         if ( aa == NULL ) {
 141             m_freem( m );
 142             return;
 143         }
 144     } else {
 145         /*
 146          * There was no 'elh' passed on. This could still be
 147          * either phase1 or phase2.
 148          * We have a long header, but we may be running on a phase 1 net.
 149          * Extract out all the info regarding this packet's src & dst.
 150          */
 151         ddpstat.ddps_long++;
 152
 153         if ( m->m_len < sizeof( struct ddpehdr ) &&
 154                 (( m = m_pullup( m, sizeof( struct ddpehdr ))) == 0 )) {
 155             ddpstat.ddps_tooshort++;
 156             return;
 157         }
 158
 159         deh = mtod( m, struct ddpehdr *);
 160         bcopy( (caddr_t)deh, (caddr_t)&ddpe, sizeof( struct ddpehdr ));
 161         ddpe.deh_bytes = ntohl( ddpe.deh_bytes );
 162         dlen = ddpe.deh_len;
 163
 164         if (( cksum = ddpe.deh_sum ) == 0 ) {
 165             ddpstat.ddps_nosum++;
 166         }
 167
 168         from.sat_addr.s_net = ddpe.deh_snet;
 169         from.sat_addr.s_node = ddpe.deh_snode;
 170         from.sat_port = ddpe.deh_sport;
 171         to.sat_addr.s_net = ddpe.deh_dnet;
 172         to.sat_addr.s_node = ddpe.deh_dnode;
 173         to.sat_port = ddpe.deh_dport;
 174
 175         if ( to.sat_addr.s_net == ATADDR_ANYNET ) {
 176             /*
 177              * The TO address doesn't specify a net,
 178              * So by definition it's for this net.
 179              * Try find ifaddr info with the right phase,
 180              * the right interface, and either to our node, a broadcast,
 181              * or looped back (though that SHOULD be covered in the other
 182              * cases).
 183              *
 184              * XXX If we have multiple interfaces, then the first with
 185              * this node number will match (which may NOT be what we want,
 186              * but it's probably safe in 99.999% of cases.
 187              */
 188             for ( aa = at_ifaddr; aa; aa = aa->aa_next ) {
 189                 if ( phase == 1 && ( aa->aa_flags & AFA_PHASE2 )) {
 190                     continue;
 191                 }
 192                 if ( phase == 2 && ( aa->aa_flags & AFA_PHASE2 ) == 0 ) {
 193                     continue;
 194                 }
 195                 if ( (aa->aa_ifp == ifp)
 196                 && ( (to.sat_addr.s_node == AA_SAT( aa )->sat_addr.s_node)
 197                   || (to.sat_addr.s_node == ATADDR_BCAST)
 198                   || (ifp->if_flags & IFF_LOOPBACK))) {
 199                     break;
 200                 }
 201             }
 202         } else {
 203             /*
 204              * A destination network was given. We just try to find
 205              * which ifaddr info matches it.
 206              */
 207             for ( aa = at_ifaddr; aa; aa = aa->aa_next ) {
 208                 /*
 209                  * This is a kludge. Accept packets that are
 210                  * for any router on a local netrange.
 211                  */
 212                 if ( to.sat_addr.s_net == aa->aa_firstnet &&
 213                         to.sat_addr.s_node == 0 ) {
 214                     break;
 215                 }
 216                 /*
 217                  * Don't use ifaddr info for which we are totally outside the
 218                  * netrange, and it's not a startup packet.
 219                  * Startup packets are always implicitly allowed on to
 220                  * the next test.
 221                  */
 222                 if ((( ntohs( to.sat_addr.s_net ) < ntohs( aa->aa_firstnet ))
 223                     || (ntohs( to.sat_addr.s_net ) > ntohs( aa->aa_lastnet )))
 224                  && (( ntohs( to.sat_addr.s_net ) < 0xff00)
 225                     || (ntohs( to.sat_addr.s_net ) > 0xfffe ))) {
 226                     continue;
 227                 }
 228
 229                 /*
 230                  * Don't record a match either if we just don't have a match
 231                  * in the node address. This can have if the interface
 232                  * is in promiscuous mode for example.
 233                  */
 234                 if (( to.sat_addr.s_node != AA_SAT( aa )->sat_addr.s_node)
 235                 && (to.sat_addr.s_node != ATADDR_BCAST) ) {
 236                     continue;
 237                 }
 238                 break;
 239             }
 240         }
 241     }
 242
 243     /*
 244      * Adjust the length, removing any padding that may have been added
 245      * at a link layer.  We do this before we attempt to forward a packet,
 246      * possibly on a different media.
 247      */
 248     mlen = m->m_pkthdr.len;
 249     if ( mlen < dlen ) {
 250         ddpstat.ddps_toosmall++;
 251         m_freem( m );
 252         return;
 253     }
 254     if ( mlen > dlen ) {
 255         m_adj( m, dlen - mlen );
 256     }
 257
 258     /*
 259      * If it aint for a net on any of our interfaces,
 260      * or it IS for a net on a different interface than it came in on,
 261      * (and it is not looped back) then consider if we should forward it.
 262      * As we are not really a router this is a bit cheeky, but it may be
 263      * useful some day.
 264      */
 265     if ( (aa == NULL)
 266     || ( (to.sat_addr.s_node == ATADDR_BCAST)
 267       && (aa->aa_ifp != ifp)
 268       && (( ifp->if_flags & IFF_LOOPBACK ) == 0 ))) {
 269         /*
 270          * If we've explicitly disabled it, don't route anything
 271          */
 272         if ( ddp_forward == 0 ) {
 273             m_freem( m );
 274             return;
 275         }
 276         /*
 277          * If the cached forwarding route is still valid, use it.
 278          */
 279         if ( forwro.ro_rt
 280         && ( satosat(&forwro.ro_dst)->sat_addr.s_net != to.sat_addr.s_net
 281           || satosat(&forwro.ro_dst)->sat_addr.s_node != to.sat_addr.s_node )) {
 282             RTFREE( forwro.ro_rt );
 283             forwro.ro_rt = (struct rtentry *)0;
 284         }
 285
 286         /*
 287          * If we don't have a cached one (any more) or it's useless,
 288          * Then get a new route.
 289          * XXX this could cause a 'route leak'. check this!
 290          */
 291         if ( forwro.ro_rt == (struct rtentry *)0
 292         || forwro.ro_rt->rt_ifp == (struct ifnet *)0 ) {
 293             forwro.ro_dst.sa_len = sizeof( struct sockaddr_at );
 294             forwro.ro_dst.sa_family = AF_APPLETALK;
 295             satosat(&forwro.ro_dst)->sat_addr.s_net = to.sat_addr.s_net;
 296             satosat(&forwro.ro_dst)->sat_addr.s_node = to.sat_addr.s_node;
 297             rtalloc(&forwro);
 298         }
 299
 300         /*
 301          * If it's not going to get there on this hop, and it's
 302          * already done too many hops, then throw it away.
 303          */
 304         if ( (to.sat_addr.s_net != satosat( &forwro.ro_dst )->sat_addr.s_net)
 305         && (ddpe.deh_hops == DDP_MAXHOPS) ) {
 306             m_freem( m );
 307             return;
 308         }
 309
 310         /*
 311          * A ddp router might use the same interface
 312          * to forward the packet, which this would not effect.
 313          * Don't allow packets to cross from one interface to another however.
 314          */
 315         if ( ddp_firewall
 316         && ( (forwro.ro_rt == NULL)
 317           || (forwro.ro_rt->rt_ifp != ifp))) {
 318             m_freem( m );
 319             return;
 320         }
 321
 322         /*
 323          * Adjust the header.
 324          * If it was a short header then it would have not gotten here,
 325          * so we can assume there is room to drop the header in.
 326          * XXX what about promiscuous mode, etc...
 327          */
 328         ddpe.deh_hops++;
 329         ddpe.deh_bytes = htonl( ddpe.deh_bytes );
 330         bcopy( (caddr_t)&ddpe, (caddr_t)deh, sizeof( u_short )); /* XXX deh? */
 331         if ( ddp_route( m, &forwro )) {
 332             ddpstat.ddps_cantforward++;
 333         } else {
 334             ddpstat.ddps_forward++;
 335         }
 336         return;
 337     }
 338
 339     /*
 340      * It was for us, and we have an ifaddr to use with it.
 341      */
 342     from.sat_len = sizeof( struct sockaddr_at );
 343     from.sat_family = AF_APPLETALK;
 344
 345     /*
 346      * We are no longer interested in the link layer.
 347      * so cut it off.
 348      */
 349     if ( elh ) {
 350         m_adj( m, sizeof( struct ddpshdr ));
 351     } else {
 352         if ( ddp_cksum && cksum && cksum != at_cksum( m, sizeof( int ))) {
 353             ddpstat.ddps_badsum++;
 354             m_freem( m );
 355             return;
 356         }
 357         m_adj( m, sizeof( struct ddpehdr ));
 358     }
 359
 360     /*
 361      * Search for ddp protocol control blocks that match these
 362      * addresses.
 363      */
 364     if (( ddp = ddp_search( &from, &to, aa )) == NULL ) {
 365         m_freem( m );
 366         return;
 367     }
 368
 369     /*
 370      * If we found one, deliver th epacket to the socket
 371      */
 372     if (ssb_appendaddr( &ddp->ddp_socket->so_rcv, (struct sockaddr *)&from,
 373             m, (struct mbuf *)0 ) == 0 ) {
 374         /*
 375          * If the socket is full (or similar error) dump the packet.
 376          */
 377         ddpstat.ddps_nosockspace++;
 378         m_freem( m );
 379         return;
 380     }
 381     /*
 382      * And wake up whatever might be waiting for it
 383      */
 384     sorwakeup( ddp->ddp_socket );
 385 }
 386
 387 #if 0
 388 /* As if we haven't got enough of this sort of think floating
 389 around the kernel :) */
 390
 391 #define BPXLEN  48
 392 #define BPALEN  16
 393 #include <ctype.h>
 394 char    hexdig[] = "0123456789ABCDEF";
 395
 396 static void
 397 bprint(char *data, int len)
 398 {
 399     char        xout[ BPXLEN ], aout[ BPALEN ];
 400     int         i = 0;
 401
 402     bzero( xout, BPXLEN );
 403     bzero( aout, BPALEN );
 404
 405     for ( ;; ) {
 406         if ( len < 1 ) {
 407             if ( i != 0 ) {
 408                 kprintf( "%s\t%s\n", xout, aout );
 409             }
 410             kprintf( "%s\n", "(end)" );
 411             break;
 412         }
 413
 414         xout[ (i*3) ] = hexdig[ ( *data & 0xf0 ) >> 4 ];
 415         xout[ (i*3) + 1 ] = hexdig[ *data & 0x0f ];
 416
 417         if ( (u_char)*data < 0x7f && (u_char)*data > 0x20 ) {
 418             aout[ i ] = *data;
 419         } else {
 420             aout[ i ] = '.';
 421         }
 422
 423         xout[ (i*3) + 2 ] = ' ';
 424
 425         i++;
 426         len--;
 427         data++;
 428
 429         if ( i > BPALEN - 2 ) {
 430             kprintf( "%s\t%s\n", xout, aout );
 431             bzero( xout, BPXLEN );
 432             bzero( aout, BPALEN );
 433             i = 0;
 434             continue;
 435         }
 436     }
 437 }
 438
 439 static void
 440 m_printm(struct mbuf *m)
 441 {
 442     for (; m; m = m->m_next ) {
 443         bprint( mtod( m, char * ), m->m_len );
 444     }
 445 }
 446 #endif