1/* $NetBSD: udp6_output.c,v 1.54 2016/10/31 04:16:25 ozaki-r Exp $ */
2/* $KAME: udp6_output.c,v 1.43 2001/10/15 09:19:52 itojun Exp $ */
3
4/*
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33/*
34 * Copyright (c) 1982, 1986, 1989, 1993
35 * The Regents of the University of California. All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 * notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 * notice, this list of conditions and the following disclaimer in the
44 * documentation and/or other materials provided with the distribution.
45 * 3. Neither the name of the University nor the names of its contributors
46 * may be used to endorse or promote products derived from this software
47 * without specific prior written permission.
48 *
49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59 * SUCH DAMAGE.
60 *
61 * @(#)udp_var.h 8.1 (Berkeley) 6/10/93
62 */
63
64#include <sys/cdefs.h>
65__KERNEL_RCSID(0, "$NetBSD: udp6_output.c,v 1.54 2016/10/31 04:16:25 ozaki-r Exp $");
66
67#ifdef _KERNEL_OPT
68#include "opt_inet.h"
69#endif
70
71#include <sys/param.h>
72#include <sys/mbuf.h>
73#include <sys/protosw.h>
74#include <sys/socket.h>
75#include <sys/socketvar.h>
76#include <sys/errno.h>
77#include <sys/stat.h>
78#include <sys/systm.h>
79#include <sys/proc.h>
80#include <sys/syslog.h>
81#include <sys/kauth.h>
82#include <sys/domain.h>
83
84#include <net/if.h>
85#include <net/if_types.h>
86
87#include <netinet/in.h>
88#include <netinet/in_var.h>
89#include <netinet/in_systm.h>
90#include <netinet/ip.h>
91#include <netinet/ip_var.h>
92#include <netinet/in_pcb.h>
93#include <netinet/udp.h>
94#include <netinet/udp_var.h>
95#include <netinet/udp_private.h>
96#include <netinet/ip6.h>
97#include <netinet6/ip6_var.h>
98#include <netinet6/in6_pcb.h>
99#include <netinet6/udp6_var.h>
100#include <netinet6/udp6_private.h>
101#include <netinet/icmp6.h>
102#include <netinet6/ip6protosw.h>
103#include <netinet6/scope6_var.h>
104
105#include "faith.h"
106
107#include <net/net_osdep.h>
108
109/*
110 * UDP protocol inplementation.
111 * Per RFC 768, August, 1980.
112 */
113
114int
115udp6_output(struct in6pcb * const in6p, struct mbuf *m,
116 struct sockaddr_in6 * const addr6, struct mbuf * const control,
117 struct lwp * const l)
118{
119 u_int32_t ulen = m->m_pkthdr.len;
120 u_int32_t plen = sizeof(struct udphdr) + ulen;
121 struct ip6_hdr *ip6;
122 struct udphdr *udp6;
123 struct in6_addr _laddr, *laddr, *faddr;
124 struct in6_addr laddr_mapped; /* XXX ugly */
125 struct sockaddr_in6 *sin6 = NULL;
126 struct ifnet *oifp = NULL;
127 int scope_ambiguous = 0;
128 u_int16_t fport;
129 int error = 0;
130 struct ip6_pktopts *optp = NULL;
131 struct ip6_pktopts opt;
132 int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
133#ifdef INET
134 struct ip *ip;
135 struct udpiphdr *ui;
136 int flags = 0;
137#endif
138 struct sockaddr_in6 tmp;
139
140 if (addr6) {
141 sin6 = addr6;
142 if (sin6->sin6_family != AF_INET6) {
143 error = EAFNOSUPPORT;
144 goto release;
145 }
146
147 /* protect *sin6 from overwrites */
148 tmp = *sin6;
149 sin6 = &tmp;
150
151 /*
152 * Application should provide a proper zone ID or the use of
153 * default zone IDs should be enabled. Unfortunately, some
154 * applications do not behave as it should, so we need a
155 * workaround. Even if an appropriate ID is not determined,
156 * we'll see if we can determine the outgoing interface. If we
157 * can, determine the zone ID based on the interface below.
158 */
159 if (sin6->sin6_scope_id == 0 && !ip6_use_defzone)
160 scope_ambiguous = 1;
161 if ((error = sa6_embedscope(sin6, ip6_use_defzone)) != 0)
162 goto release;
163 }
164
165 if (control) {
166 if ((error = ip6_setpktopts(control, &opt,
167 in6p->in6p_outputopts, l->l_cred, IPPROTO_UDP)) != 0)
168 goto release;
169 optp = &opt;
170 } else
171 optp = in6p->in6p_outputopts;
172
173
174 if (sin6) {
175 /*
176 * Slightly different than v4 version in that we call
177 * in6_selectsrc and in6_pcbsetport to fill in the local
178 * address and port rather than in_pcbconnect. in_pcbconnect
179 * sets in6p_faddr which causes EISCONN below to be hit on
180 * subsequent sendto.
181 */
182 if (sin6->sin6_port == 0) {
183 error = EADDRNOTAVAIL;
184 goto release;
185 }
186
187 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
188 /* how about ::ffff:0.0.0.0 case? */
189 error = EISCONN;
190 goto release;
191 }
192
193
194 faddr = &sin6->sin6_addr;
195 fport = sin6->sin6_port; /* allow 0 port */
196
197 if (IN6_IS_ADDR_V4MAPPED(faddr)) {
198 if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY))
199 {
200 /*
201 * I believe we should explicitly discard the
202 * packet when mapped addresses are disabled,
203 * rather than send the packet as an IPv6 one.
204 * If we chose the latter approach, the packet
205 * might be sent out on the wire based on the
206 * default route, the situation which we'd
207 * probably want to avoid.
208 * (20010421 jinmei@kame.net)
209 */
210 error = EINVAL;
211 goto release;
212 }
213 if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)
214 && !IN6_IS_ADDR_V4MAPPED(&in6p->in6p_laddr)) {
215 /*
216 * when remote addr is an IPv4-mapped address,
217 * local addr should not be an IPv6 address,
218 * since you cannot determine how to map IPv6
219 * source address to IPv4.
220 */
221 error = EINVAL;
222 goto release;
223 }
224
225 af = AF_INET;
226 }
227
228 if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
229 struct psref psref;
230 int bound = curlwp_bind();
231
232 error = in6_selectsrc(sin6, optp,
233 in6p->in6p_moptions,
234 &in6p->in6p_route,
235 &in6p->in6p_laddr, &oifp, &psref, &_laddr);
236 /* XXX need error check? */
237 if (oifp && scope_ambiguous &&
238 (error = in6_setscope(&sin6->sin6_addr,
239 oifp, NULL))) {
240 if_put(oifp, &psref);
241 curlwp_bindx(bound);
242 goto release;
243 }
244 if_put(oifp, &psref);
245 curlwp_bindx(bound);
246 laddr = &_laddr;
247 } else {
248 /*
249 * XXX: freebsd[34] does not have in_selectsrc, but
250 * we can omit the whole part because freebsd4 calls
251 * udp_output() directly in this case, and thus we'll
252 * never see this path.
253 */
254 if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_laddr)) {
255 struct sockaddr_in sin_dst;
256 struct in_addr ina;
257 struct in_ifaddr *ia4;
258 struct psref _psref;
259 int bound;
260
261 memcpy(&ina, &faddr->s6_addr[12], sizeof(ina));
262 sockaddr_in_init(&sin_dst, &ina, 0);
263 bound = curlwp_bind();
264 ia4 = in_selectsrc(&sin_dst, &in6p->in6p_route,
265 in6p->in6p_socket->so_options, NULL,
266 &error, &_psref);
267 if (ia4 == NULL) {
268 curlwp_bindx(bound);
269 if (error == 0)
270 error = EADDRNOTAVAIL;
271 goto release;
272 }
273 memset(&laddr_mapped, 0, sizeof(laddr_mapped));
274 laddr_mapped.s6_addr16[5] = 0xffff; /* ugly */
275 memcpy(&laddr_mapped.s6_addr[12],
276 &IA_SIN(ia4)->sin_addr,
277 sizeof(IA_SIN(ia4)->sin_addr));
278 ia4_release(ia4, &_psref);
279 curlwp_bindx(bound);
280 laddr = &laddr_mapped;
281 } else
282 {
283 laddr = &in6p->in6p_laddr; /* XXX */
284 }
285 }
286 if (laddr == NULL) {
287 if (error == 0)
288 error = EADDRNOTAVAIL;
289 goto release;
290 }
291 if (in6p->in6p_lport == 0) {
292 /*
293 * Craft a sockaddr_in6 for the local endpoint. Use the
294 * "any" as a base, set the address, and recover the
295 * scope.
296 */
297 struct sockaddr_in6 lsin6 =
298 *((const struct sockaddr_in6 *)in6p->in6p_socket->so_proto->pr_domain->dom_sa_any);
299 lsin6.sin6_addr = *laddr;
300 error = sa6_recoverscope(&lsin6);
301 if (error)
302 goto release;
303
304 error = in6_pcbsetport(&lsin6, in6p, l);
305
306 if (error) {
307 in6p->in6p_laddr = in6addr_any;
308 goto release;
309 }
310 }
311 } else {
312 if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
313 error = ENOTCONN;
314 goto release;
315 }
316 if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr)) {
317 if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY))
318 {
319 /*
320 * XXX: this case would happen when the
321 * application sets the V6ONLY flag after
322 * connecting the foreign address.
323 * Such applications should be fixed,
324 * so we bark here.
325 */
326 log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
327 "option was set for a connected socket\n");
328 error = EINVAL;
329 goto release;
330 } else
331 af = AF_INET;
332 }
333 laddr = &in6p->in6p_laddr;
334 faddr = &in6p->in6p_faddr;
335 fport = in6p->in6p_fport;
336 }
337
338 if (af == AF_INET)
339 hlen = sizeof(struct ip);
340
341 /*
342 * Calculate data length and get a mbuf
343 * for UDP and IP6 headers.
344 */
345 M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
346 if (m == 0) {
347 error = ENOBUFS;
348 goto release;
349 }
350
351 /*
352 * Stuff checksum and output datagram.
353 */
354 udp6 = (struct udphdr *)(mtod(m, char *) + hlen);
355 udp6->uh_sport = in6p->in6p_lport; /* lport is always set in the PCB */
356 udp6->uh_dport = fport;
357 if (plen <= 0xffff)
358 udp6->uh_ulen = htons((u_int16_t)plen);
359 else
360 udp6->uh_ulen = 0;
361 udp6->uh_sum = 0;
362
363 switch (af) {
364 case AF_INET6:
365 ip6 = mtod(m, struct ip6_hdr *);
366 ip6->ip6_flow = in6p->in6p_flowinfo & IPV6_FLOWINFO_MASK;
367 ip6->ip6_vfc &= ~IPV6_VERSION_MASK;
368 ip6->ip6_vfc |= IPV6_VERSION;
369#if 0 /* ip6_plen will be filled in ip6_output. */
370 ip6->ip6_plen = htons((u_int16_t)plen);
371#endif
372 ip6->ip6_nxt = IPPROTO_UDP;
373 ip6->ip6_hlim = in6_selecthlim_rt(in6p);
374 ip6->ip6_src = *laddr;
375 ip6->ip6_dst = *faddr;
376
377 udp6->uh_sum = in6_cksum_phdr(laddr, faddr,
378 htonl(plen), htonl(IPPROTO_UDP));
379 m->m_pkthdr.csum_flags = M_CSUM_UDPv6;
380 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
381
382 UDP6_STATINC(UDP6_STAT_OPACKETS);
383 error = ip6_output(m, optp, &in6p->in6p_route, 0,
384 in6p->in6p_moptions, in6p->in6p_socket, NULL);
385 break;
386 case AF_INET:
387#ifdef INET
388 /* can't transmit jumbogram over IPv4 */
389 if (plen > 0xffff) {
390 error = EMSGSIZE;
391 goto release;
392 }
393
394 ip = mtod(m, struct ip *);
395 ui = (struct udpiphdr *)ip;
396 memset(ui->ui_x1, 0, sizeof(ui->ui_x1));
397 ui->ui_pr = IPPROTO_UDP;
398 ui->ui_len = htons(plen);
399 memcpy(&ui->ui_src, &laddr->s6_addr[12], sizeof(ui->ui_src));
400 ui->ui_ulen = ui->ui_len;
401
402 flags = (in6p->in6p_socket->so_options &
403 (SO_DONTROUTE | SO_BROADCAST));
404 memcpy(&ui->ui_dst, &faddr->s6_addr[12], sizeof(ui->ui_dst));
405
406 udp6->uh_sum = in_cksum(m, hlen + plen);
407 if (udp6->uh_sum == 0)
408 udp6->uh_sum = 0xffff;
409
410 ip->ip_len = htons(hlen + plen);
411 ip->ip_ttl = in6_selecthlim(in6p, NULL); /* XXX */
412 ip->ip_tos = 0; /* XXX */
413
414 UDP_STATINC(UDP_STAT_OPACKETS);
415 error = ip_output(m, NULL, &in6p->in6p_route, flags /* XXX */,
416 in6p->in6p_v4moptions, (struct socket *)in6p->in6p_socket);
417 break;
418#else
419 error = EAFNOSUPPORT;
420 goto release;
421#endif
422 }
423 goto releaseopt;
424
425release:
426 m_freem(m);
427
428releaseopt:
429 if (control) {
430 if (optp == &opt)
431 ip6_clearpktopts(&opt, -1);
432 m_freem(control);
433 }
434 return (error);
435}
436