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 /* $FreeBSD$ */
25
26 #include <sys/param.h>
27 #include <sys/systm.h>
28 #include <sys/mbuf.h>
29 #include <sys/socket.h>
30 #include <sys/socketvar.h>
31
32 #include <net/if.h>
33 #include <net/route.h>
34
35 #undef s_net
36
37 #include <netatalk/at.h>
38 #include <netatalk/at_var.h>
39 #include <netatalk/ddp.h>
40 #include <netatalk/ddp_var.h>
41 #include <netatalk/at_extern.h>
42
43 #include <security/mac/mac_framework.h>
44
45 int ddp_cksum = 1;
46
47 int
ddp_output(struct mbuf * m,struct socket * so)48 ddp_output(struct mbuf *m, struct socket *so)
49 {
50 struct ddpehdr *deh;
51 struct ddpcb *ddp = sotoddpcb(so);
52
53 #ifdef MAC
54 mac_socket_create_mbuf(so, m);
55 #endif
56
57 M_PREPEND(m, sizeof(struct ddpehdr), M_NOWAIT);
58 if (m == NULL)
59 return (ENOBUFS);
60
61 deh = mtod(m, struct ddpehdr *);
62 deh->deh_pad = 0;
63 deh->deh_hops = 0;
64
65 deh->deh_len = m->m_pkthdr.len;
66
67 deh->deh_dnet = ddp->ddp_fsat.sat_addr.s_net;
68 deh->deh_dnode = ddp->ddp_fsat.sat_addr.s_node;
69 deh->deh_dport = ddp->ddp_fsat.sat_port;
70 deh->deh_snet = ddp->ddp_lsat.sat_addr.s_net;
71 deh->deh_snode = ddp->ddp_lsat.sat_addr.s_node;
72 deh->deh_sport = ddp->ddp_lsat.sat_port;
73
74 /*
75 * The checksum calculation is done after all of the other bytes have
76 * been filled in.
77 */
78 if (ddp_cksum)
79 deh->deh_sum = at_cksum(m, sizeof(int));
80 else
81 deh->deh_sum = 0;
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
at_cksum(struct mbuf * m,int skip)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;
100 data < end; data++) {
101 if (skip) {
102 skip--;
103 continue;
104 }
105 cksum = (cksum + *data) << 1;
106 if (cksum & 0x00010000)
107 cksum++;
108 cksum &= 0x0000ffff;
109 }
110 }
111
112 if (cksum == 0)
113 cksum = 0x0000ffff;
114 return ((u_short)cksum);
115 }
116
117 int
ddp_route(struct mbuf * m,struct route * ro)118 ddp_route(struct mbuf *m, struct route *ro)
119 {
120 struct sockaddr_at gate;
121 struct elaphdr *elh;
122 struct mbuf *m0;
123 struct at_ifaddr *aa = NULL;
124 struct ifnet *ifp = NULL;
125 u_short net;
126
127 #if 0
128 /* Check for net zero, node zero ("myself") */
129 if (satosat(&ro->ro_dst)->sat_addr.s_net == ATADDR_ANYNET
130 && satosat(&ro->ro_dst)->sat_addr.s_node == ATADDR_ANYNODE) {
131 /* Find the loopback interface */
132 }
133 #endif
134
135 /*
136 * If we have a route, find the ifa that refers to this route. I.e
137 * the ifa used to get to the gateway.
138 */
139 if ((ro->ro_rt == NULL) || (ro->ro_rt->rt_ifa == NULL) ||
140 ((ifp = ro->ro_rt->rt_ifa->ifa_ifp) == NULL))
141 rtalloc(ro);
142 if ((ro->ro_rt != NULL) && (ro->ro_rt->rt_ifa) &&
143 (ifp = ro->ro_rt->rt_ifa->ifa_ifp)) {
144 net = ntohs(satosat(ro->ro_rt->rt_gateway)->sat_addr.s_net);
145 AT_IFADDR_RLOCK();
146 TAILQ_FOREACH(aa, &at_ifaddrhead, aa_link) {
147 if (((net == 0) || (aa->aa_ifp == ifp)) &&
148 net >= ntohs(aa->aa_firstnet) &&
149 net <= ntohs(aa->aa_lastnet))
150 break;
151 }
152 if (aa != NULL)
153 ifa_ref(&aa->aa_ifa);
154 AT_IFADDR_RUNLOCK();
155 } else {
156 m_freem(m);
157 #ifdef NETATALK_DEBUG
158 if (ro->ro_rt == NULL)
159 printf ("ddp_route: no ro_rt.\n");
160 else if (ro->ro_rt->rt_ifa == NULL)
161 printf ("ddp_route: no ro_rt->rt_ifa\n");
162 else
163 printf ("ddp_route: no ro_rt->rt_ifa->ifa_ifp\n");
164 #endif
165 return (ENETUNREACH);
166 }
167
168 if (aa == NULL) {
169 #ifdef NETATALK_DEBUG
170 printf("ddp_route: no atalk address found for %s\n",
171 ifp->if_xname);
172 #endif
173 m_freem(m);
174 return (ENETUNREACH);
175 }
176
177 /*
178 * If the destination address is on a directly attached node use
179 * that, else use the official gateway.
180 */
181 if (ntohs(satosat(&ro->ro_dst)->sat_addr.s_net) >=
182 ntohs(aa->aa_firstnet) &&
183 ntohs(satosat(&ro->ro_dst)->sat_addr.s_net) <=
184 ntohs(aa->aa_lastnet))
185 gate = *satosat(&ro->ro_dst);
186 else
187 gate = *satosat(ro->ro_rt->rt_gateway);
188
189 /*
190 * There are several places in the kernel where data is added to an
191 * mbuf without ensuring that the mbuf pointer is aligned. This is
192 * bad for transition routing, since phase 1 and phase 2 packets end
193 * up poorly aligned due to the three byte elap header.
194 *
195 * XXXRW: kern/4184 suggests that an m_pullup() of (m) should take
196 * place here to address possible alignment issues.
197 *
198 * XXXRW: This appears not to handle M_PKTHDR properly, as it doesn't
199 * move the existing header from the old packet to the new one.
200 * Posibly should call M_MOVE_PKTHDR()? This would also allow
201 * removing mac_mbuf_copy().
202 */
203 if (!(aa->aa_flags & AFA_PHASE2)) {
204 MGET(m0, M_NOWAIT, MT_DATA);
205 if (m0 == NULL) {
206 ifa_free(&aa->aa_ifa);
207 m_freem(m);
208 printf("ddp_route: no buffers\n");
209 return (ENOBUFS);
210 }
211 #ifdef MAC
212 mac_mbuf_copy(m, m0);
213 #endif
214 m0->m_next = m;
215 /* XXX perhaps we ought to align the header? */
216 m0->m_len = SZ_ELAPHDR;
217 m = m0;
218
219 elh = mtod(m, struct elaphdr *);
220 elh->el_snode = satosat(&aa->aa_addr)->sat_addr.s_node;
221 elh->el_type = ELAP_DDPEXTEND;
222 elh->el_dnode = gate.sat_addr.s_node;
223 }
224 counter_u64_add(ro->ro_rt->rt_pksent, 1);
225
226 #ifdef NETATALK_DEBUG
227 printf ("ddp_route: from %d.%d to %d.%d, via %d.%d (%s)\n",
228 ntohs(satosat(&aa->aa_addr)->sat_addr.s_net),
229 satosat(&aa->aa_addr)->sat_addr.s_node,
230 ntohs(satosat(&ro->ro_dst)->sat_addr.s_net),
231 satosat(&ro->ro_dst)->sat_addr.s_node,
232 ntohs(gate.sat_addr.s_net), gate.sat_addr.s_node, ifp->if_xname);
233 #endif
234
235 /* Short-circuit the output if we're sending this to ourself. */
236 if ((satosat(&aa->aa_addr)->sat_addr.s_net ==
237 satosat(&ro->ro_dst)->sat_addr.s_net) &&
238 (satosat(&aa->aa_addr)->sat_addr.s_node ==
239 satosat(&ro->ro_dst)->sat_addr.s_node)) {
240 ifa_free(&aa->aa_ifa);
241 return (if_simloop(ifp, m, gate.sat_family, 0));
242 }
243 ifa_free(&aa->aa_ifa);
244
245 /* XXX */
246 return ((*ifp->if_output)(ifp, m, (struct sockaddr *)&gate, NULL));
247 }
248