xref: /netbsd-src/sys/netatalk/ddp_output.c (revision 06be8101a16cc95f40783b3cb7afd12112103a9a)
1 /*	$NetBSD: ddp_output.c,v 1.3 2001/11/13 00:00:58 lukem 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 1.3 2001/11/13 00:00:58 lukem Exp $");
31 
32 #include <sys/types.h>
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/mbuf.h>
36 #include <sys/socket.h>
37 #include <sys/errno.h>
38 #include <sys/syslog.h>
39 
40 #include <net/if.h>
41 #include <net/route.h>
42 #include <net/if_ether.h>
43 
44 #include <netinet/in.h>
45 #undef s_net
46 
47 #include <netatalk/at.h>
48 #include <netatalk/at_var.h>
49 #include <netatalk/ddp.h>
50 #include <netatalk/ddp_var.h>
51 #include <netatalk/at_extern.h>
52 
53 #include <machine/stdarg.h>
54 
55 int ddp_cksum = 1;
56 
57 int
58 #if __STDC__
59 ddp_output(struct mbuf *m,...)
60 #else
61 ddp_output(va_alist)
62 	va_dcl
63 #endif
64 {
65 	struct ddpcb   *ddp;
66 	struct ddpehdr *deh;
67 	va_list         ap;
68 
69 #if __STDC__
70 	va_start(ap, m);
71 #else
72 	struct mbuf    *m;
73 
74 	va_start(ap);
75 	m = va_arg(ap, struct mbuf *);
76 #endif
77 	ddp = va_arg(ap, struct ddpcb *);
78 	va_end(ap);
79 
80 	M_PREPEND(m, sizeof(struct ddpehdr), M_WAIT);
81 
82 	deh = mtod(m, struct ddpehdr *);
83 	deh->deh_pad = 0;
84 	deh->deh_hops = 0;
85 
86 	deh->deh_len = m->m_pkthdr.len;
87 
88 	deh->deh_dnet = ddp->ddp_fsat.sat_addr.s_net;
89 	deh->deh_dnode = ddp->ddp_fsat.sat_addr.s_node;
90 	deh->deh_dport = ddp->ddp_fsat.sat_port;
91 	deh->deh_snet = ddp->ddp_lsat.sat_addr.s_net;
92 	deh->deh_snode = ddp->ddp_lsat.sat_addr.s_node;
93 	deh->deh_sport = ddp->ddp_lsat.sat_port;
94 
95 	/*
96          * The checksum calculation is done after all of the other bytes have
97          * been filled in.
98          */
99 	if (ddp_cksum) {
100 		deh->deh_sum = at_cksum(m, sizeof(int));
101 	} else {
102 		deh->deh_sum = 0;
103 	}
104 	deh->deh_bytes = htonl(deh->deh_bytes);
105 
106 	return (ddp_route(m, &ddp->ddp_route));
107 }
108 
109 u_short
110 at_cksum(m, skip)
111 	struct mbuf *m;
112 	int skip;
113 {
114 	u_char         *data, *end;
115 	u_long          cksum = 0;
116 
117 	for (; m; m = m->m_next) {
118 		for (data = mtod(m, u_char *), end = data + m->m_len;
119 		    data < end; data++) {
120 			if (skip) {
121 				skip--;
122 				continue;
123 			}
124 			cksum = (cksum + *data) << 1;
125 			if (cksum & 0x00010000) {
126 				cksum++;
127 			}
128 			cksum &= 0x0000ffff;
129 		}
130 	}
131 
132 	if (cksum == 0) {
133 		cksum = 0x0000ffff;
134 	}
135 	return ((u_short) cksum);
136 }
137 
138 int
139 ddp_route(m, ro)
140 	struct mbuf *m;
141 	struct route *ro;
142 {
143 	struct sockaddr_at gate;
144 	struct elaphdr *elh;
145 	struct mbuf    *m0;
146 	struct at_ifaddr *aa = NULL;
147 	struct ifnet   *ifp = NULL;
148 	u_short         net;
149 
150 	if (ro->ro_rt && (ifp = ro->ro_rt->rt_ifp)) {
151 		net = satosat(ro->ro_rt->rt_gateway)->sat_addr.s_net;
152 		for (aa = at_ifaddr.tqh_first; aa; aa = aa->aa_list.tqe_next) {
153 			if (aa->aa_ifp == ifp &&
154 			    ntohs(net) >= ntohs(aa->aa_firstnet) &&
155 			    ntohs(net) <= ntohs(aa->aa_lastnet)) {
156 				break;
157 			}
158 		}
159 	}
160 	if (aa == NULL) {
161 		printf("ddp_route: oops\n");
162 		m_freem(m);
163 		return (EINVAL);
164 	}
165 	/*
166          * There are several places in the kernel where data is added to
167          * an mbuf without ensuring that the mbuf pointer is aligned.
168          * This is bad for transition routing, since phase 1 and phase 2
169          * packets end up poorly aligned due to the three byte elap header.
170          */
171 	if (!(aa->aa_flags & AFA_PHASE2)) {
172 		MGET(m0, M_WAIT, MT_HEADER);
173 		if (m0 == 0) {
174 			m_freem(m);
175 			printf("ddp_route: no buffers\n");
176 			return (ENOBUFS);
177 		}
178 		m0->m_next = m;
179 		/* XXX perhaps we ought to align the header? */
180 		m0->m_len = SZ_ELAPHDR;
181 		m = m0;
182 
183 		elh = mtod(m, struct elaphdr *);
184 		elh->el_snode = satosat(&aa->aa_addr)->sat_addr.s_node;
185 		elh->el_type = ELAP_DDPEXTEND;
186 		if (ntohs(satosat(&ro->ro_dst)->sat_addr.s_net) >=
187 		    ntohs(aa->aa_firstnet) &&
188 		    ntohs(satosat(&ro->ro_dst)->sat_addr.s_net) <=
189 		    ntohs(aa->aa_lastnet)) {
190 			elh->el_dnode = satosat(&ro->ro_dst)->sat_addr.s_node;
191 		} else {
192 			elh->el_dnode =
193 			    satosat(ro->ro_rt->rt_gateway)->sat_addr.s_node;
194 		}
195 	}
196 	if (ntohs(satosat(&ro->ro_dst)->sat_addr.s_net) >=
197 	    ntohs(aa->aa_firstnet) &&
198 	    ntohs(satosat(&ro->ro_dst)->sat_addr.s_net) <=
199 	    ntohs(aa->aa_lastnet)) {
200 		gate = *satosat(&ro->ro_dst);
201 	} else {
202 		gate = *satosat(ro->ro_rt->rt_gateway);
203 	}
204 	ro->ro_rt->rt_use++;
205 
206 #if IFA_STATS
207 	aa->aa_ifa.ifa_data.ifad_outbytes += m->m_pkthdr.len;
208 #endif
209 
210 	/* XXX */
211 	return ((*ifp->if_output) (ifp, m, (struct sockaddr *) &gate, NULL));
212 }
213