1 /*
2 * Copyright (c) 1990,1991 Regents of The University of Michigan.
3 * All Rights Reserved.
4 *
5 * Permission to use, copy, modify, and distribute this software and
6 * its documentation for any purpose and without fee is hereby granted,
7 * provided that the above copyright notice appears in all copies and
8 * that both that copyright notice and this permission notice appear
9 * in supporting documentation, and that the name of The University
10 * of Michigan not be used in advertising or publicity pertaining to
11 * distribution of the software without specific, written prior
12 * permission. This software is supplied as is without expressed or
13 * implied warranties of any kind.
14 *
15 * Research Systems Unix Group
16 * The University of Michigan
17 * c/o Mike Clark
18 * 535 W. William Street
19 * Ann Arbor, Michigan
20 * +1-313-763-0525
21 * netatalk@itd.umich.edu
22 */
23
24 /* $FreeBSD: releng/5.0/sys/netatalk/ddp_output.c 101937 2002-08-15 18:58:44Z rwatson $ */
25
26 #include "opt_mac.h"
27
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/mac.h>
31 #include <sys/mbuf.h>
32 #include <sys/socket.h>
33 #include <sys/socketvar.h>
34
35 #include <net/if.h>
36 #include <net/route.h>
37
38 #undef s_net
39
40 #include <netatalk/at.h>
41 #include <netatalk/at_var.h>
42 #include <netatalk/ddp.h>
43 #include <netatalk/ddp_var.h>
44 #include <netatalk/at_extern.h>
45
46 int ddp_cksum = 1;
47
48 int
49 ddp_output( struct mbuf *m, struct socket *so)
50 {
51 struct ddpehdr *deh;
52 struct ddpcb *ddp = sotoddpcb( so );
53
54 #ifdef MAC
55 mac_create_mbuf_from_socket(so, m);
56 #endif
57
58 M_PREPEND( m, sizeof( struct ddpehdr ), M_TRYWAIT );
59
60 deh = mtod( m, struct ddpehdr *);
61 deh->deh_pad = 0;
62 deh->deh_hops = 0;
63
64 deh->deh_len = m->m_pkthdr.len;
65
66 deh->deh_dnet = ddp->ddp_fsat.sat_addr.s_net;
67 deh->deh_dnode = ddp->ddp_fsat.sat_addr.s_node;
68 deh->deh_dport = ddp->ddp_fsat.sat_port;
69 deh->deh_snet = ddp->ddp_lsat.sat_addr.s_net;
70 deh->deh_snode = ddp->ddp_lsat.sat_addr.s_node;
71 deh->deh_sport = ddp->ddp_lsat.sat_port;
72
73 /*
74 * The checksum calculation is done after all of the other bytes have
75 * been filled in.
76 */
77 if ( ddp_cksum ) {
78 deh->deh_sum = at_cksum( m, sizeof( int ));
79 } else {
80 deh->deh_sum = 0;
81 }
82 deh->deh_bytes = htonl( deh->deh_bytes );
83
84 #ifdef NETATALK_DEBUG
85 printf ("ddp_output: from %d.%d:%d to %d.%d:%d\n",
86 ntohs(deh->deh_snet), deh->deh_snode, deh->deh_sport,
87 ntohs(deh->deh_dnet), deh->deh_dnode, deh->deh_dport);
88 #endif
89 return( ddp_route( m, &ddp->ddp_route ));
90 }
91
92 u_short
93 at_cksum( struct mbuf *m, int skip)
94 {
95 u_char *data, *end;
96 u_long cksum = 0;
97
98 for (; m; m = m->m_next ) {
99 for ( data = mtod( m, u_char * ), end = data + m->m_len; data < end;
100 data++ ) {
101 if ( skip ) {
102 skip--;
103 continue;
104 }
105 cksum = ( cksum + *data ) << 1;
106 if ( cksum & 0x00010000 ) {
107 cksum++;
108 }
109 cksum &= 0x0000ffff;
110 }
111 }
112
113 if ( cksum == 0 ) {
114 cksum = 0x0000ffff;
115 }
116 return( (u_short)cksum );
117 }
118
119 int
120 ddp_route( struct mbuf *m, struct route *ro)
121 {
122 struct sockaddr_at gate;
123 struct elaphdr *elh;
124 struct mbuf *m0;
125 struct at_ifaddr *aa = NULL;
126 struct ifnet *ifp = NULL;
127 u_short net;
128
129 #if 0
130 /* Check for net zero, node zero ("myself") */
131 if (satosat(&ro->ro_dst)->sat_addr.s_net == ATADDR_ANYNET
132 && satosat(&ro->ro_dst)->sat_addr.s_node == ATADDR_ANYNODE) {
133 /* Find the loopback interface */
134 }
135 #endif
136
137 /*
138 * if we have a route, find the ifa that refers to this route.
139 * I.e The ifa used to get to the gateway.
140 */
141 if ( (ro->ro_rt == NULL)
142 || ( ro->ro_rt->rt_ifa == NULL )
143 || ( (ifp = ro->ro_rt->rt_ifa->ifa_ifp) == NULL )) {
144 rtalloc(ro);
145 }
146 if ( (ro->ro_rt != NULL)
147 && ( ro->ro_rt->rt_ifa )
148 && ( ifp = ro->ro_rt->rt_ifa->ifa_ifp )) {
149 net = ntohs(satosat(ro->ro_rt->rt_gateway)->sat_addr.s_net);
150 for ( aa = at_ifaddr; aa; aa = aa->aa_next ) {
151 if (((net == 0) || (aa->aa_ifp == ifp)) &&
152 net >= ntohs( aa->aa_firstnet ) &&
153 net <= ntohs( aa->aa_lastnet )) {
154 break;
155 }
156 }
157 } else {
158 m_freem( m );
159 #ifdef NETATALK_DEBUG
160 if (ro->ro_rt == NULL)
161 printf ("ddp_route: no ro_rt.\n");
162 else if (ro->ro_rt->rt_ifa == NULL)
163 printf ("ddp_route: no ro_rt->rt_ifa\n");
164 else
165 printf ("ddp_route: no ro_rt->rt_ifa->ifa_ifp\n");
166 #endif
167 return( ENETUNREACH );
168 }
169
170 if ( aa == NULL ) {
171 #ifdef NETATALK_DEBUG
172 printf( "ddp_route: no atalk address found for %s%d\n",
173 ifp->if_name, ifp->if_unit);
174 #endif
175 m_freem( m );
176 return( ENETUNREACH );
177 }
178
179 /*
180 * if the destination address is on a directly attached node use that,
181 * else use the official gateway.
182 */
183 if ( ntohs( satosat( &ro->ro_dst )->sat_addr.s_net ) >=
184 ntohs( aa->aa_firstnet ) &&
185 ntohs( satosat( &ro->ro_dst )->sat_addr.s_net ) <=
186 ntohs( aa->aa_lastnet )) {
187 gate = *satosat( &ro->ro_dst );
188 } else {
189 gate = *satosat( ro->ro_rt->rt_gateway );
190 }
191
192 /*
193 * There are several places in the kernel where data is added to
194 * an mbuf without ensuring that the mbuf pointer is aligned.
195 * This is bad for transition routing, since phase 1 and phase 2
196 * packets end up poorly aligned due to the three byte elap header.
197 */
198 if ( !(aa->aa_flags & AFA_PHASE2) ) {
199 MGET( m0, M_TRYWAIT, MT_HEADER );
200 if ( m0 == 0 ) {
201 m_freem( m );
202 printf("ddp_route: no buffers\n");
203 return( ENOBUFS );
204 }
205 #ifdef MAC
206 mac_create_mbuf_from_mbuf(m, m0);
207 #endif
208 m0->m_next = m;
209 /* XXX perhaps we ought to align the header? */
210 m0->m_len = SZ_ELAPHDR;
211 m = m0;
212
213 elh = mtod( m, struct elaphdr *);
214 elh->el_snode = satosat( &aa->aa_addr )->sat_addr.s_node;
215 elh->el_type = ELAP_DDPEXTEND;
216 elh->el_dnode = gate.sat_addr.s_node;
217 }
218 ro->ro_rt->rt_use++;
219
220 #ifdef NETATALK_DEBUG
221 printf ("ddp_route: from %d.%d to %d.%d, via %d.%d (%s%d)\n",
222 ntohs(satosat(&aa->aa_addr)->sat_addr.s_net),
223 satosat(&aa->aa_addr)->sat_addr.s_node,
224 ntohs(satosat(&ro->ro_dst)->sat_addr.s_net),
225 satosat(&ro->ro_dst)->sat_addr.s_node,
226 ntohs(gate.sat_addr.s_net),
227 gate.sat_addr.s_node,
228 ifp->if_name, ifp->if_unit);
229 #endif
230
231 /* short-circuit the output if we're sending this to ourself */
232 if ((satosat(&aa->aa_addr)->sat_addr.s_net == satosat(&ro->ro_dst)->sat_addr.s_net) &&
233 (satosat(&aa->aa_addr)->sat_addr.s_node == satosat(&ro->ro_dst)->sat_addr.s_node))
234 {
235 return (if_simloop(ifp, m, gate.sat_family, 0));
236 }
237
238 return((*ifp->if_output)( ifp,
239 m, (struct sockaddr *)&gate, NULL)); /* XXX */
240 }
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