/* $NetBSD: ddp_output.c,v 1.21.34.1 2023/07/31 16:37:18 martin Exp $ */ /* * Copyright (c) 1990,1991 Regents of The University of Michigan. * All Rights Reserved. * * Permission to use, copy, modify, and distribute this software and * its documentation for any purpose and without fee is hereby granted, * provided that the above copyright notice appears in all copies and * that both that copyright notice and this permission notice appear * in supporting documentation, and that the name of The University * of Michigan not be used in advertising or publicity pertaining to * distribution of the software without specific, written prior * permission. This software is supplied as is without expressed or * implied warranties of any kind. * * This product includes software developed by the University of * California, Berkeley and its contributors. * * Research Systems Unix Group * The University of Michigan * c/o Wesley Craig * 535 W. William Street * Ann Arbor, Michigan * +1-313-764-2278 * netatalk@umich.edu */ #include __KERNEL_RCSID(0, "$NetBSD: ddp_output.c,v 1.21.34.1 2023/07/31 16:37:18 martin Exp $"); #include "opt_atalk.h" #include #include #include #include #include #include #include #include #include #include #undef s_net #include #include #include #include #include int ddp_cksum = 1; int ddp_output(struct mbuf *m, struct ddpcb *ddp) { struct ddpehdr *deh; M_PREPEND(m, sizeof(struct ddpehdr), M_DONTWAIT); if (!m) return (ENOBUFS); deh = mtod(m, struct ddpehdr *); deh->deh_pad = 0; deh->deh_hops = 0; deh->deh_len = m->m_pkthdr.len; deh->deh_dnet = ddp->ddp_fsat.sat_addr.s_net; deh->deh_dnode = ddp->ddp_fsat.sat_addr.s_node; deh->deh_dport = ddp->ddp_fsat.sat_port; deh->deh_snet = ddp->ddp_lsat.sat_addr.s_net; deh->deh_snode = ddp->ddp_lsat.sat_addr.s_node; deh->deh_sport = ddp->ddp_lsat.sat_port; /* * The checksum calculation is done after all of the other bytes have * been filled in. */ if (ddp_cksum) deh->deh_sum = at_cksum(m, sizeof(int)); else deh->deh_sum = 0; deh->deh_bytes = htonl(deh->deh_bytes); return ddp_route(m, &ddp->ddp_route); } u_short at_cksum(struct mbuf *m, int skip) { u_char *data, *end; u_long cksum = 0; for (; m; m = m->m_next) { for (data = mtod(m, u_char *), end = data + m->m_len; data < end; data++) { if (skip) { skip--; continue; } cksum = (cksum + *data) << 1; if (cksum & 0x00010000) cksum++; cksum &= 0x0000ffff; } } if (cksum == 0) { cksum = 0x0000ffff; } return (u_short)cksum; } int ddp_route(struct mbuf *m, struct route *ro) { struct rtentry *rt; struct sockaddr_at gate; struct elaphdr *elh; struct at_ifaddr *aa = NULL; struct ifnet *ifp = NULL; uint16_t net; uint8_t loopback = 0; int error; if ((rt = rtcache_validate(ro)) != NULL && (ifp = rt->rt_ifp) != NULL) { const struct sockaddr_at *dst = satocsat(rtcache_getdst(ro)); uint16_t dnet = dst->sat_addr.s_net; uint8_t dnode = dst->sat_addr.s_node; net = satosat(rt->rt_gateway)->sat_addr.s_net; TAILQ_FOREACH(aa, &at_ifaddr, aa_list) { if (ntohs(net) >= ntohs(aa->aa_firstnet) && ntohs(net) <= ntohs(aa->aa_lastnet)) { /* Are we talking to ourselves? */ if (dnet == aa->aa_addr.sat_addr.s_net && dnode == aa->aa_addr.sat_addr.s_node) { /* If to us, redirect to lo0. */ ifp = lo0ifp; } /* Or is it a broadcast? */ else if (dnet == aa->aa_addr.sat_addr.s_net && dnode == 255) { /* If broadcast, loop back a copy. */ loopback = 1; } break; } } } if (aa == NULL) { #ifdef NETATALKDEBUG printf("%s: no address found\n", __func__); #endif m_freem(m); error = EINVAL; goto out; } /* * There are several places in the kernel where data is added to * an mbuf without ensuring that the mbuf pointer is aligned. * This is bad for transition routing, since phase 1 and phase 2 * packets end up poorly aligned due to the three byte elap header. */ if (!(aa->aa_flags & AFA_PHASE2)) { M_PREPEND(m, SZ_ELAPHDR, M_DONTWAIT); if (m == NULL) { error = ENOBUFS; goto out; } elh = mtod(m, struct elaphdr *); elh->el_snode = aa->aa_addr.sat_addr.s_node; elh->el_type = ELAP_DDPEXTEND; if (ntohs(satocsat(rtcache_getdst(ro))->sat_addr.s_net) >= ntohs(aa->aa_firstnet) && ntohs(satocsat(rtcache_getdst(ro))->sat_addr.s_net) <= ntohs(aa->aa_lastnet)) { elh->el_dnode = satocsat(rtcache_getdst(ro))->sat_addr.s_node; } else { elh->el_dnode = satosat(rt->rt_gateway)->sat_addr.s_node; } } if (ntohs(satocsat(rtcache_getdst(ro))->sat_addr.s_net) >= ntohs(aa->aa_firstnet) && ntohs(satocsat(rtcache_getdst(ro))->sat_addr.s_net) <= ntohs(aa->aa_lastnet)) { gate = *satocsat(rtcache_getdst(ro)); } else { gate = *satosat(rt->rt_gateway); } rt->rt_use++; #if IFA_STATS aa->aa_ifa.ifa_data.ifad_outbytes += m->m_pkthdr.len; #endif /* XXX */ if (loopback && rtcache_getdst(ro)->sa_family == AF_APPLETALK) { struct mbuf *copym = m_copypacket(m, M_DONTWAIT); #ifdef NETATALKDEBUG printf("Looping back (not AARP).\n"); #endif looutput(lo0ifp, copym, rtcache_getdst(ro), NULL); } error = if_output_lock(ifp, ifp, m, (struct sockaddr *)&gate, NULL); out: rtcache_unref(rt, ro); return error; }