| 1 | /* $NetBSD: ddp_output.c,v 1.19 2016/06/20 06:46:38 knakahara 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 1.19 2016/06/20 06:46:38 knakahara 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 | int ddp_cksum = 1; |
| 53 | |
| 54 | int |
| 55 | ddp_output(struct mbuf *m, struct ddpcb *ddp) |
| 56 | { |
| 57 | struct ddpehdr *deh; |
| 58 | |
| 59 | M_PREPEND(m, sizeof(struct ddpehdr), M_DONTWAIT); |
| 60 | if (!m) |
| 61 | return (ENOBUFS); |
| 62 | |
| 63 | deh = mtod(m, struct ddpehdr *); |
| 64 | deh->deh_pad = 0; |
| 65 | deh->deh_hops = 0; |
| 66 | |
| 67 | deh->deh_len = m->m_pkthdr.len; |
| 68 | |
| 69 | deh->deh_dnet = ddp->ddp_fsat.sat_addr.s_net; |
| 70 | deh->deh_dnode = ddp->ddp_fsat.sat_addr.s_node; |
| 71 | deh->deh_dport = ddp->ddp_fsat.sat_port; |
| 72 | deh->deh_snet = ddp->ddp_lsat.sat_addr.s_net; |
| 73 | deh->deh_snode = ddp->ddp_lsat.sat_addr.s_node; |
| 74 | deh->deh_sport = ddp->ddp_lsat.sat_port; |
| 75 | |
| 76 | /* |
| 77 | * The checksum calculation is done after all of the other bytes have |
| 78 | * been filled in. |
| 79 | */ |
| 80 | if (ddp_cksum) |
| 81 | deh->deh_sum = at_cksum(m, sizeof(int)); |
| 82 | else |
| 83 | deh->deh_sum = 0; |
| 84 | deh->deh_bytes = htonl(deh->deh_bytes); |
| 85 | |
| 86 | return ddp_route(m, &ddp->ddp_route); |
| 87 | } |
| 88 | |
| 89 | u_short |
| 90 | at_cksum(struct mbuf *m, int skip) |
| 91 | { |
| 92 | u_char *data, *end; |
| 93 | u_long cksum = 0; |
| 94 | |
| 95 | for (; m; m = m->m_next) { |
| 96 | for (data = mtod(m, u_char *), end = data + m->m_len; |
| 97 | data < end; data++) { |
| 98 | if (skip) { |
| 99 | skip--; |
| 100 | continue; |
| 101 | } |
| 102 | cksum = (cksum + *data) << 1; |
| 103 | if (cksum & 0x00010000) |
| 104 | cksum++; |
| 105 | cksum &= 0x0000ffff; |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | if (cksum == 0) { |
| 110 | cksum = 0x0000ffff; |
| 111 | } |
| 112 | return (u_short)cksum; |
| 113 | } |
| 114 | |
| 115 | int |
| 116 | ddp_route(struct mbuf *m, struct route *ro) |
| 117 | { |
| 118 | struct rtentry *rt; |
| 119 | struct sockaddr_at gate; |
| 120 | struct elaphdr *elh; |
| 121 | struct at_ifaddr *aa = NULL; |
| 122 | struct ifnet *ifp = NULL; |
| 123 | uint16_t net; |
| 124 | uint8_t loopback = 0; |
| 125 | |
| 126 | if ((rt = rtcache_validate(ro)) != NULL && (ifp = rt->rt_ifp) != NULL) { |
| 127 | const struct sockaddr_at *dst = satocsat(rtcache_getdst(ro)); |
| 128 | uint16_t dnet = dst->sat_addr.s_net; |
| 129 | uint8_t dnode = dst->sat_addr.s_node; |
| 130 | net = satosat(rt->rt_gateway)->sat_addr.s_net; |
| 131 | |
| 132 | TAILQ_FOREACH(aa, &at_ifaddr, aa_list) { |
| 133 | if (ntohs(net) >= ntohs(aa->aa_firstnet) && |
| 134 | ntohs(net) <= ntohs(aa->aa_lastnet)) { |
| 135 | /* Are we talking to ourselves? */ |
| 136 | if (dnet == aa->aa_addr.sat_addr.s_net && |
| 137 | dnode == aa->aa_addr.sat_addr.s_node) { |
| 138 | /* If to us, redirect to lo0. */ |
| 139 | ifp = lo0ifp; |
| 140 | } |
| 141 | /* Or is it a broadcast? */ |
| 142 | else if (dnet == aa->aa_addr.sat_addr.s_net && |
| 143 | dnode == 255) { |
| 144 | /* If broadcast, loop back a copy. */ |
| 145 | loopback = 1; |
| 146 | } |
| 147 | break; |
| 148 | } |
| 149 | } |
| 150 | } |
| 151 | if (aa == NULL) { |
| 152 | #ifdef NETATALKDEBUG |
| 153 | printf("%s: no address found\n" , __func__); |
| 154 | #endif |
| 155 | m_freem(m); |
| 156 | return EINVAL; |
| 157 | } |
| 158 | /* |
| 159 | * There are several places in the kernel where data is added to |
| 160 | * an mbuf without ensuring that the mbuf pointer is aligned. |
| 161 | * This is bad for transition routing, since phase 1 and phase 2 |
| 162 | * packets end up poorly aligned due to the three byte elap header. |
| 163 | */ |
| 164 | if (!(aa->aa_flags & AFA_PHASE2)) { |
| 165 | M_PREPEND(m, SZ_ELAPHDR, M_DONTWAIT); |
| 166 | if (m == NULL) |
| 167 | return ENOBUFS; |
| 168 | |
| 169 | elh = mtod(m, struct elaphdr *); |
| 170 | elh->el_snode = satosat(&aa->aa_addr)->sat_addr.s_node; |
| 171 | elh->el_type = ELAP_DDPEXTEND; |
| 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 | elh->el_dnode = |
| 177 | satocsat(rtcache_getdst(ro))->sat_addr.s_node; |
| 178 | } else { |
| 179 | elh->el_dnode = |
| 180 | satosat(rt->rt_gateway)->sat_addr.s_node; |
| 181 | } |
| 182 | } |
| 183 | if (ntohs(satocsat(rtcache_getdst(ro))->sat_addr.s_net) >= |
| 184 | ntohs(aa->aa_firstnet) && |
| 185 | ntohs(satocsat(rtcache_getdst(ro))->sat_addr.s_net) <= |
| 186 | ntohs(aa->aa_lastnet)) { |
| 187 | gate = *satocsat(rtcache_getdst(ro)); |
| 188 | } else { |
| 189 | gate = *satosat(rt->rt_gateway); |
| 190 | } |
| 191 | rt->rt_use++; |
| 192 | |
| 193 | #if IFA_STATS |
| 194 | aa->aa_ifa.ifa_data.ifad_outbytes += m->m_pkthdr.len; |
| 195 | #endif |
| 196 | |
| 197 | /* XXX */ |
| 198 | if (loopback && rtcache_getdst(ro)->sa_family == AF_APPLETALK) { |
| 199 | struct mbuf *copym = m_copypacket(m, M_DONTWAIT); |
| 200 | |
| 201 | #ifdef NETATALKDEBUG |
| 202 | printf("Looping back (not AARP).\n" ); |
| 203 | #endif |
| 204 | looutput(lo0ifp, copym, rtcache_getdst(ro), NULL); |
| 205 | } |
| 206 | return if_output_lock(ifp, ifp, m, (struct sockaddr *)&gate, NULL); |
| 207 | } |
| 208 | |