sys/netatalk/ddp_output.c

   1 /*      $NetBSD: ddp_output.c,v 1.13 2008/01/14 04:12:40 dyoung Exp $    */
   2
   3 /*
   4  * Copyright (c) 1990,1991 Regents of The University of Michigan.
   5  * All Rights Reserved.
   6  *
   7  * Permission to use, copy, modify, and distribute this software and
   8  * its documentation for any purpose and without fee is hereby granted,
   9  * provided that the above copyright notice appears in all copies and
  10  * that both that copyright notice and this permission notice appear
  11  * in supporting documentation, and that the name of The University
  12  * of Michigan not be used in advertising or publicity pertaining to
  13  * distribution of the software without specific, written prior
  14  * permission. This software is supplied as is without expressed or
  15  * implied warranties of any kind.
  16  *
  17  * This product includes software developed by the University of
  18  * California, Berkeley and its contributors.
  19  *
  20  *      Research Systems Unix Group
  21  *      The University of Michigan
  22  *      c/o Wesley Craig
  23  *      535 W. William Street
  24  *      Ann Arbor, Michigan
  25  *      +1-313-764-2278
  26  *      netatalk@umich.edu
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __KERNEL_RCSID(0, "$NetBSD: ddp_output.c,v 1.13 2008/01/14 04:12:40 dyoung Exp $");
  31
  32 #include <sys/param.h>
  33 #include <sys/systm.h>
  34 #include <sys/mbuf.h>
  35 #include <sys/socket.h>
  36 #include <sys/errno.h>
  37 #include <sys/syslog.h>
  38
  39 #include <net/if.h>
  40 #include <net/route.h>
  41 #include <net/if_ether.h>
  42
  43 #include <netinet/in.h>
  44 #undef s_net
  45
  46 #include <netatalk/at.h>
  47 #include <netatalk/at_var.h>
  48 #include <netatalk/ddp.h>
  49 #include <netatalk/ddp_var.h>
  50 #include <netatalk/at_extern.h>
  51
  52 #include <machine/stdarg.h>
  53
  54 int ddp_cksum = 1;
  55
  56 int
  57 ddp_output(struct mbuf *m,...)
  58 {
  59         struct ddpcb   *ddp;
  60         struct ddpehdr *deh;
  61         va_list         ap;
  62
  63         va_start(ap, m);
  64         ddp = va_arg(ap, struct ddpcb *);
  65         va_end(ap);
  66
  67         M_PREPEND(m, sizeof(struct ddpehdr), M_DONTWAIT);
  68         if (!m)
  69                 return (ENOBUFS);
  70
  71         deh = mtod(m, struct ddpehdr *);
  72         deh->deh_pad = 0;
  73         deh->deh_hops = 0;
  74
  75         deh->deh_len = m->m_pkthdr.len;
  76
  77         deh->deh_dnet = ddp->ddp_fsat.sat_addr.s_net;
  78         deh->deh_dnode = ddp->ddp_fsat.sat_addr.s_node;
  79         deh->deh_dport = ddp->ddp_fsat.sat_port;
  80         deh->deh_snet = ddp->ddp_lsat.sat_addr.s_net;
  81         deh->deh_snode = ddp->ddp_lsat.sat_addr.s_node;
  82         deh->deh_sport = ddp->ddp_lsat.sat_port;
  83
  84         /*
  85          * The checksum calculation is done after all of the other bytes have
  86          * been filled in.
  87          */
  88         if (ddp_cksum)
  89                 deh->deh_sum = at_cksum(m, sizeof(int));
  90         else
  91                 deh->deh_sum = 0;
  92         deh->deh_bytes = htonl(deh->deh_bytes);
  93
  94         return ddp_route(m, &ddp->ddp_route);
  95 }
  96
  97 u_short
  98 at_cksum(struct mbuf *m, int skip)
  99 {
 100         u_char         *data, *end;
 101         u_long          cksum = 0;
 102
 103         for (; m; m = m->m_next) {
 104                 for (data = mtod(m, u_char *), end = data + m->m_len;
 105                     data < end; data++) {
 106                         if (skip) {
 107                                 skip--;
 108                                 continue;
 109                         }
 110                         cksum = (cksum + *data) << 1;
 111                         if (cksum & 0x00010000)
 112                                 cksum++;
 113                         cksum &= 0x0000ffff;
 114                 }
 115         }
 116
 117         if (cksum == 0) {
 118                 cksum = 0x0000ffff;
 119         }
 120         return (u_short)cksum;
 121 }
 122
 123 int
 124 ddp_route(struct mbuf *m, struct route *ro)
 125 {
 126         struct rtentry *rt;
 127         struct sockaddr_at gate;
 128         struct elaphdr *elh;
 129         struct at_ifaddr *aa = NULL;
 130         struct ifnet   *ifp = NULL;
 131         u_short         net;
 132
 133         if ((rt = rtcache_validate(ro)) != NULL && (ifp = rt->rt_ifp) != NULL) {
 134                 net = satosat(rt->rt_gateway)->sat_addr.s_net;
 135                 TAILQ_FOREACH(aa, &at_ifaddr, aa_list) {
 136                         if (aa->aa_ifp == ifp &&
 137                             ntohs(net) >= ntohs(aa->aa_firstnet) &&
 138                             ntohs(net) <= ntohs(aa->aa_lastnet)) {
 139                                 break;
 140                         }
 141                 }
 142         }
 143         if (aa == NULL) {
 144                 printf("%s: no address found\n", __func__);
 145                 m_freem(m);
 146                 return EINVAL;
 147         }
 148         /*
 149          * There are several places in the kernel where data is added to
 150          * an mbuf without ensuring that the mbuf pointer is aligned.
 151          * This is bad for transition routing, since phase 1 and phase 2
 152          * packets end up poorly aligned due to the three byte elap header.
 153          */
 154         if (!(aa->aa_flags & AFA_PHASE2)) {
 155                 M_PREPEND(m, SZ_ELAPHDR, M_DONTWAIT);
 156                 if (m == NULL)
 157                         return ENOBUFS;
 158
 159                 elh = mtod(m, struct elaphdr *);
 160                 elh->el_snode = satosat(&aa->aa_addr)->sat_addr.s_node;
 161                 elh->el_type = ELAP_DDPEXTEND;
 162                 if (ntohs(satocsat(rtcache_getdst(ro))->sat_addr.s_net) >=
 163                     ntohs(aa->aa_firstnet) &&
 164                     ntohs(satocsat(rtcache_getdst(ro))->sat_addr.s_net) <=
 165                     ntohs(aa->aa_lastnet)) {
 166                         elh->el_dnode = satocsat(rtcache_getdst(ro))->sat_addr.s_node;
 167                 } else {
 168                         elh->el_dnode =
 169                             satosat(rt->rt_gateway)->sat_addr.s_node;
 170                 }
 171         }
 172         if (ntohs(satocsat(rtcache_getdst(ro))->sat_addr.s_net) >=
 173             ntohs(aa->aa_firstnet) &&
 174             ntohs(satocsat(rtcache_getdst(ro))->sat_addr.s_net) <=
 175             ntohs(aa->aa_lastnet)) {
 176                 gate = *satocsat(rtcache_getdst(ro));
 177         } else {
 178                 gate = *satosat(rt->rt_gateway);
 179         }
 180         rt->rt_use++;
 181
 182 #if IFA_STATS
 183         aa->aa_ifa.ifa_data.ifad_outbytes += m->m_pkthdr.len;
 184 #endif
 185
 186         /* XXX */
 187         return (*ifp->if_output)(ifp, m, (struct sockaddr *)&gate, NULL);
 188 }