xref: /netbsd-src/sys/netatalk/ddp_output.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: ddp_output.c,v 1.8 2004/04/25 21:14:21 matt 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 1.8 2004/04/25 21:14:21 matt 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 	}
93 	deh->deh_bytes = htonl(deh->deh_bytes);
94 
95 	return (ddp_route(m, &ddp->ddp_route));
96 }
97 
98 u_short
99 at_cksum(m, skip)
100 	struct mbuf *m;
101 	int skip;
102 {
103 	u_char         *data, *end;
104 	u_long          cksum = 0;
105 
106 	for (; m; m = m->m_next) {
107 		for (data = mtod(m, u_char *), end = data + m->m_len;
108 		    data < end; data++) {
109 			if (skip) {
110 				skip--;
111 				continue;
112 			}
113 			cksum = (cksum + *data) << 1;
114 			if (cksum & 0x00010000) {
115 				cksum++;
116 			}
117 			cksum &= 0x0000ffff;
118 		}
119 	}
120 
121 	if (cksum == 0) {
122 		cksum = 0x0000ffff;
123 	}
124 	return ((u_short) cksum);
125 }
126 
127 int
128 ddp_route(m, ro)
129 	struct mbuf *m;
130 	struct route *ro;
131 {
132 	struct sockaddr_at gate;
133 	struct elaphdr *elh;
134 	struct at_ifaddr *aa = NULL;
135 	struct ifnet   *ifp = NULL;
136 	u_short         net;
137 
138 	if (ro->ro_rt && (ifp = ro->ro_rt->rt_ifp)) {
139 		net = satosat(ro->ro_rt->rt_gateway)->sat_addr.s_net;
140 		for (aa = at_ifaddr.tqh_first; aa; aa = aa->aa_list.tqe_next) {
141 			if (aa->aa_ifp == ifp &&
142 			    ntohs(net) >= ntohs(aa->aa_firstnet) &&
143 			    ntohs(net) <= ntohs(aa->aa_lastnet)) {
144 				break;
145 			}
146 		}
147 	}
148 	if (aa == NULL) {
149 		printf("ddp_route: oops\n");
150 		m_freem(m);
151 		return (EINVAL);
152 	}
153 	/*
154          * There are several places in the kernel where data is added to
155          * an mbuf without ensuring that the mbuf pointer is aligned.
156          * This is bad for transition routing, since phase 1 and phase 2
157          * packets end up poorly aligned due to the three byte elap header.
158          */
159 	if (!(aa->aa_flags & AFA_PHASE2)) {
160 		M_PREPEND(m, SZ_ELAPHDR, M_DONTWAIT);
161 		if (!m)
162 			return (ENOBUFS);
163 
164 		elh = mtod(m, struct elaphdr *);
165 		elh->el_snode = satosat(&aa->aa_addr)->sat_addr.s_node;
166 		elh->el_type = ELAP_DDPEXTEND;
167 		if (ntohs(satosat(&ro->ro_dst)->sat_addr.s_net) >=
168 		    ntohs(aa->aa_firstnet) &&
169 		    ntohs(satosat(&ro->ro_dst)->sat_addr.s_net) <=
170 		    ntohs(aa->aa_lastnet)) {
171 			elh->el_dnode = satosat(&ro->ro_dst)->sat_addr.s_node;
172 		} else {
173 			elh->el_dnode =
174 			    satosat(ro->ro_rt->rt_gateway)->sat_addr.s_node;
175 		}
176 	}
177 	if (ntohs(satosat(&ro->ro_dst)->sat_addr.s_net) >=
178 	    ntohs(aa->aa_firstnet) &&
179 	    ntohs(satosat(&ro->ro_dst)->sat_addr.s_net) <=
180 	    ntohs(aa->aa_lastnet)) {
181 		gate = *satosat(&ro->ro_dst);
182 	} else {
183 		gate = *satosat(ro->ro_rt->rt_gateway);
184 	}
185 	ro->ro_rt->rt_use++;
186 
187 #if IFA_STATS
188 	aa->aa_ifa.ifa_data.ifad_outbytes += m->m_pkthdr.len;
189 #endif
190 
191 	/* XXX */
192 	return ((*ifp->if_output) (ifp, m, (struct sockaddr *) &gate, NULL));
193 }
194