1 | /* $NetBSD: ddp_output.c,v 1.19 2016/06/20 06:46:38 knakahara 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 1.19 2016/06/20 06:46:38 knakahara 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 | int ddp_cksum = 1; |
53 | |
54 | int |
55 | ddp_output(struct mbuf *m, struct ddpcb *ddp) |
56 | { |
57 | struct ddpehdr *deh; |
58 | |
59 | M_PREPEND(m, sizeof(struct ddpehdr), M_DONTWAIT); |
60 | if (!m) |
61 | return (ENOBUFS); |
62 | |
63 | deh = mtod(m, struct ddpehdr *); |
64 | deh->deh_pad = 0; |
65 | deh->deh_hops = 0; |
66 | |
67 | deh->deh_len = m->m_pkthdr.len; |
68 | |
69 | deh->deh_dnet = ddp->ddp_fsat.sat_addr.s_net; |
70 | deh->deh_dnode = ddp->ddp_fsat.sat_addr.s_node; |
71 | deh->deh_dport = ddp->ddp_fsat.sat_port; |
72 | deh->deh_snet = ddp->ddp_lsat.sat_addr.s_net; |
73 | deh->deh_snode = ddp->ddp_lsat.sat_addr.s_node; |
74 | deh->deh_sport = ddp->ddp_lsat.sat_port; |
75 | |
76 | /* |
77 | * The checksum calculation is done after all of the other bytes have |
78 | * been filled in. |
79 | */ |
80 | if (ddp_cksum) |
81 | deh->deh_sum = at_cksum(m, sizeof(int)); |
82 | else |
83 | deh->deh_sum = 0; |
84 | deh->deh_bytes = htonl(deh->deh_bytes); |
85 | |
86 | return ddp_route(m, &ddp->ddp_route); |
87 | } |
88 | |
89 | u_short |
90 | at_cksum(struct mbuf *m, int skip) |
91 | { |
92 | u_char *data, *end; |
93 | u_long cksum = 0; |
94 | |
95 | for (; m; m = m->m_next) { |
96 | for (data = mtod(m, u_char *), end = data + m->m_len; |
97 | data < end; data++) { |
98 | if (skip) { |
99 | skip--; |
100 | continue; |
101 | } |
102 | cksum = (cksum + *data) << 1; |
103 | if (cksum & 0x00010000) |
104 | cksum++; |
105 | cksum &= 0x0000ffff; |
106 | } |
107 | } |
108 | |
109 | if (cksum == 0) { |
110 | cksum = 0x0000ffff; |
111 | } |
112 | return (u_short)cksum; |
113 | } |
114 | |
115 | int |
116 | ddp_route(struct mbuf *m, struct route *ro) |
117 | { |
118 | struct rtentry *rt; |
119 | struct sockaddr_at gate; |
120 | struct elaphdr *elh; |
121 | struct at_ifaddr *aa = NULL; |
122 | struct ifnet *ifp = NULL; |
123 | uint16_t net; |
124 | uint8_t loopback = 0; |
125 | |
126 | if ((rt = rtcache_validate(ro)) != NULL && (ifp = rt->rt_ifp) != NULL) { |
127 | const struct sockaddr_at *dst = satocsat(rtcache_getdst(ro)); |
128 | uint16_t dnet = dst->sat_addr.s_net; |
129 | uint8_t dnode = dst->sat_addr.s_node; |
130 | net = satosat(rt->rt_gateway)->sat_addr.s_net; |
131 | |
132 | TAILQ_FOREACH(aa, &at_ifaddr, aa_list) { |
133 | if (ntohs(net) >= ntohs(aa->aa_firstnet) && |
134 | ntohs(net) <= ntohs(aa->aa_lastnet)) { |
135 | /* Are we talking to ourselves? */ |
136 | if (dnet == aa->aa_addr.sat_addr.s_net && |
137 | dnode == aa->aa_addr.sat_addr.s_node) { |
138 | /* If to us, redirect to lo0. */ |
139 | ifp = lo0ifp; |
140 | } |
141 | /* Or is it a broadcast? */ |
142 | else if (dnet == aa->aa_addr.sat_addr.s_net && |
143 | dnode == 255) { |
144 | /* If broadcast, loop back a copy. */ |
145 | loopback = 1; |
146 | } |
147 | break; |
148 | } |
149 | } |
150 | } |
151 | if (aa == NULL) { |
152 | #ifdef NETATALKDEBUG |
153 | printf("%s: no address found\n" , __func__); |
154 | #endif |
155 | m_freem(m); |
156 | return EINVAL; |
157 | } |
158 | /* |
159 | * There are several places in the kernel where data is added to |
160 | * an mbuf without ensuring that the mbuf pointer is aligned. |
161 | * This is bad for transition routing, since phase 1 and phase 2 |
162 | * packets end up poorly aligned due to the three byte elap header. |
163 | */ |
164 | if (!(aa->aa_flags & AFA_PHASE2)) { |
165 | M_PREPEND(m, SZ_ELAPHDR, M_DONTWAIT); |
166 | if (m == NULL) |
167 | return ENOBUFS; |
168 | |
169 | elh = mtod(m, struct elaphdr *); |
170 | elh->el_snode = satosat(&aa->aa_addr)->sat_addr.s_node; |
171 | elh->el_type = ELAP_DDPEXTEND; |
172 | if (ntohs(satocsat(rtcache_getdst(ro))->sat_addr.s_net) >= |
173 | ntohs(aa->aa_firstnet) && |
174 | ntohs(satocsat(rtcache_getdst(ro))->sat_addr.s_net) <= |
175 | ntohs(aa->aa_lastnet)) { |
176 | elh->el_dnode = |
177 | satocsat(rtcache_getdst(ro))->sat_addr.s_node; |
178 | } else { |
179 | elh->el_dnode = |
180 | satosat(rt->rt_gateway)->sat_addr.s_node; |
181 | } |
182 | } |
183 | if (ntohs(satocsat(rtcache_getdst(ro))->sat_addr.s_net) >= |
184 | ntohs(aa->aa_firstnet) && |
185 | ntohs(satocsat(rtcache_getdst(ro))->sat_addr.s_net) <= |
186 | ntohs(aa->aa_lastnet)) { |
187 | gate = *satocsat(rtcache_getdst(ro)); |
188 | } else { |
189 | gate = *satosat(rt->rt_gateway); |
190 | } |
191 | rt->rt_use++; |
192 | |
193 | #if IFA_STATS |
194 | aa->aa_ifa.ifa_data.ifad_outbytes += m->m_pkthdr.len; |
195 | #endif |
196 | |
197 | /* XXX */ |
198 | if (loopback && rtcache_getdst(ro)->sa_family == AF_APPLETALK) { |
199 | struct mbuf *copym = m_copypacket(m, M_DONTWAIT); |
200 | |
201 | #ifdef NETATALKDEBUG |
202 | printf("Looping back (not AARP).\n" ); |
203 | #endif |
204 | looutput(lo0ifp, copym, rtcache_getdst(ro), NULL); |
205 | } |
206 | return if_output_lock(ifp, ifp, m, (struct sockaddr *)&gate, NULL); |
207 | } |
208 | |