xref: /netbsd-src/sys/netatalk/ddp_output.c (revision 001c68bd94f75ce9270b69227c4199fbf34ee396)
1 /*	$NetBSD: ddp_output.c,v 1.7 2003/05/27 22:27:21 itojun 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 1.7 2003/05/27 22:27:21 itojun 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 #if __STDC__
58 ddp_output(struct mbuf *m,...)
59 #else
60 ddp_output(va_alist)
61 	va_dcl
62 #endif
63 {
64 	struct ddpcb   *ddp;
65 	struct ddpehdr *deh;
66 	va_list         ap;
67 
68 #if __STDC__
69 	va_start(ap, m);
70 #else
71 	struct mbuf    *m;
72 
73 	va_start(ap);
74 	m = va_arg(ap, struct mbuf *);
75 #endif
76 	ddp = va_arg(ap, struct ddpcb *);
77 	va_end(ap);
78 
79 	M_PREPEND(m, sizeof(struct ddpehdr), M_DONTWAIT);
80 	if (!m)
81 		return (ENOBUFS);
82 
83 	deh = mtod(m, struct ddpehdr *);
84 	deh->deh_pad = 0;
85 	deh->deh_hops = 0;
86 
87 	deh->deh_len = m->m_pkthdr.len;
88 
89 	deh->deh_dnet = ddp->ddp_fsat.sat_addr.s_net;
90 	deh->deh_dnode = ddp->ddp_fsat.sat_addr.s_node;
91 	deh->deh_dport = ddp->ddp_fsat.sat_port;
92 	deh->deh_snet = ddp->ddp_lsat.sat_addr.s_net;
93 	deh->deh_snode = ddp->ddp_lsat.sat_addr.s_node;
94 	deh->deh_sport = ddp->ddp_lsat.sat_port;
95 
96 	/*
97          * The checksum calculation is done after all of the other bytes have
98          * been filled in.
99          */
100 	if (ddp_cksum) {
101 		deh->deh_sum = at_cksum(m, sizeof(int));
102 	} else {
103 		deh->deh_sum = 0;
104 	}
105 	deh->deh_bytes = htonl(deh->deh_bytes);
106 
107 	return (ddp_route(m, &ddp->ddp_route));
108 }
109 
110 u_short
111 at_cksum(m, skip)
112 	struct mbuf *m;
113 	int skip;
114 {
115 	u_char         *data, *end;
116 	u_long          cksum = 0;
117 
118 	for (; m; m = m->m_next) {
119 		for (data = mtod(m, u_char *), end = data + m->m_len;
120 		    data < end; data++) {
121 			if (skip) {
122 				skip--;
123 				continue;
124 			}
125 			cksum = (cksum + *data) << 1;
126 			if (cksum & 0x00010000) {
127 				cksum++;
128 			}
129 			cksum &= 0x0000ffff;
130 		}
131 	}
132 
133 	if (cksum == 0) {
134 		cksum = 0x0000ffff;
135 	}
136 	return ((u_short) cksum);
137 }
138 
139 int
140 ddp_route(m, ro)
141 	struct mbuf *m;
142 	struct route *ro;
143 {
144 	struct sockaddr_at gate;
145 	struct elaphdr *elh;
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 		M_PREPEND(m, SZ_ELAPHDR, M_DONTWAIT);
173 		if (!m)
174 			return (ENOBUFS);
175 
176 		elh = mtod(m, struct elaphdr *);
177 		elh->el_snode = satosat(&aa->aa_addr)->sat_addr.s_node;
178 		elh->el_type = ELAP_DDPEXTEND;
179 		if (ntohs(satosat(&ro->ro_dst)->sat_addr.s_net) >=
180 		    ntohs(aa->aa_firstnet) &&
181 		    ntohs(satosat(&ro->ro_dst)->sat_addr.s_net) <=
182 		    ntohs(aa->aa_lastnet)) {
183 			elh->el_dnode = satosat(&ro->ro_dst)->sat_addr.s_node;
184 		} else {
185 			elh->el_dnode =
186 			    satosat(ro->ro_rt->rt_gateway)->sat_addr.s_node;
187 		}
188 	}
189 	if (ntohs(satosat(&ro->ro_dst)->sat_addr.s_net) >=
190 	    ntohs(aa->aa_firstnet) &&
191 	    ntohs(satosat(&ro->ro_dst)->sat_addr.s_net) <=
192 	    ntohs(aa->aa_lastnet)) {
193 		gate = *satosat(&ro->ro_dst);
194 	} else {
195 		gate = *satosat(ro->ro_rt->rt_gateway);
196 	}
197 	ro->ro_rt->rt_use++;
198 
199 #if IFA_STATS
200 	aa->aa_ifa.ifa_data.ifad_outbytes += m->m_pkthdr.len;
201 #endif
202 
203 	/* XXX */
204 	return ((*ifp->if_output) (ifp, m, (struct sockaddr *) &gate, NULL));
205 }
206