1/*
2 * Copyright (c) 2000-2014 Apple Inc. All rights reserved.
3 *
4 * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5 *
6 * This file contains Original Code and/or Modifications of Original Code
7 * as defined in and that are subject to the Apple Public Source License
8 * Version 2.0 (the 'License'). You may not use this file except in
9 * compliance with the License. The rights granted to you under the License
10 * may not be used to create, or enable the creation or redistribution of,
11 * unlawful or unlicensed copies of an Apple operating system, or to
12 * circumvent, violate, or enable the circumvention or violation of, any
13 * terms of an Apple operating system software license agreement.
14 *
15 * Please obtain a copy of the License at
16 * http://www.opensource.apple.com/apsl/ and read it before using this file.
17 *
18 * The Original Code and all software distributed under the License are
19 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23 * Please see the License for the specific language governing rights and
24 * limitations under the License.
25 *
26 * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27 */
28
29
30/*	$FreeBSD: src/sys/netinet6/udp6_output.c,v 1.1.2.3 2001/08/31 13:49:58 jlemon Exp $	*/
31/*	$KAME: udp6_output.c,v 1.31 2001/05/21 16:39:15 jinmei Exp $	*/
32
33/*
34 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
35 * 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 project 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 PROJECT 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 PROJECT 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
62/*
63 * Copyright (c) 1982, 1986, 1989, 1993
64 *	The Regents of the University of California.  All rights reserved.
65 *
66 * Redistribution and use in source and binary forms, with or without
67 * modification, are permitted provided that the following conditions
68 * are met:
69 * 1. Redistributions of source code must retain the above copyright
70 *    notice, this list of conditions and the following disclaimer.
71 * 2. Redistributions in binary form must reproduce the above copyright
72 *    notice, this list of conditions and the following disclaimer in the
73 *    documentation and/or other materials provided with the distribution.
74 * 3. All advertising materials mentioning features or use of this software
75 *    must display the following acknowledgement:
76 *	This product includes software developed by the University of
77 *	California, Berkeley and its contributors.
78 * 4. Neither the name of the University nor the names of its contributors
79 *    may be used to endorse or promote products derived from this software
80 *    without specific prior written permission.
81 *
82 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
83 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
84 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
85 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
86 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
87 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
88 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
89 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
90 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
91 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
92 * SUCH DAMAGE.
93 *
94 *	@(#)udp_var.h	8.1 (Berkeley) 6/10/93
95 */
96
97#include <sys/param.h>
98#include <sys/malloc.h>
99#include <sys/mbuf.h>
100#include <sys/protosw.h>
101#include <sys/socket.h>
102#include <sys/socketvar.h>
103#include <sys/sysctl.h>
104#include <sys/errno.h>
105#include <sys/stat.h>
106#include <sys/systm.h>
107#include <sys/proc.h>
108#include <sys/syslog.h>
109
110#include <machine/endian.h>
111
112#include <net/if.h>
113#include <net/route.h>
114#include <net/if_types.h>
115#include <net/ntstat.h>
116
117#include <netinet/in.h>
118#include <netinet/in_var.h>
119#include <netinet/in_systm.h>
120#include <netinet/ip.h>
121#include <netinet/ip_var.h>
122#include <netinet/in_pcb.h>
123#include <netinet/udp.h>
124#include <netinet/udp_var.h>
125#include <netinet/ip6.h>
126#include <netinet6/ip6_var.h>
127#include <netinet6/in6_pcb.h>
128#include <netinet6/udp6_var.h>
129#include <netinet/icmp6.h>
130#include <netinet6/ip6protosw.h>
131
132#if NECP
133#include <net/necp.h>
134#endif /* NECP */
135
136#include <net/net_osdep.h>
137
138/*
139 * UDP protocol inplementation.
140 * Per RFC 768, August, 1980.
141 */
142
143int
144udp6_output(struct in6pcb *in6p, struct mbuf *m, struct sockaddr *addr6,
145    struct mbuf *control, struct proc *p)
146{
147	u_int32_t ulen = m->m_pkthdr.len;
148	u_int32_t plen = sizeof (struct udphdr) + ulen;
149	struct ip6_hdr *ip6;
150	struct udphdr *udp6;
151	struct in6_addr *laddr, *faddr;
152	u_short fport;
153	int error = 0;
154	struct ip6_pktopts opt, *optp = NULL;
155	struct ip6_moptions *im6o;
156	int af = AF_INET6, hlen = sizeof (struct ip6_hdr);
157	int flags;
158	struct sockaddr_in6 tmp;
159	struct	in6_addr storage;
160	mbuf_svc_class_t msc = MBUF_SC_UNSPEC;
161	struct ip6_out_args ip6oa =
162	    { IFSCOPE_NONE, { 0 }, IP6OAF_SELECT_SRCIF, 0 };
163	struct flowadv *adv = &ip6oa.ip6oa_flowadv;
164	struct socket *so = in6p->in6p_socket;
165	struct route_in6 ro;
166	int flowadv = 0;
167
168	/* Enable flow advisory only when connected */
169	flowadv = (so->so_state & SS_ISCONNECTED) ? 1 : 0;
170
171	if (flowadv && INP_WAIT_FOR_IF_FEEDBACK(in6p)) {
172		error = ENOBUFS;
173		goto release;
174	}
175
176	if (in6p->inp_flags & INP_BOUND_IF) {
177		ip6oa.ip6oa_boundif = in6p->inp_boundifp->if_index;
178		ip6oa.ip6oa_flags |= IP6OAF_BOUND_IF;
179	}
180	if (INP_NO_CELLULAR(in6p))
181		ip6oa.ip6oa_flags |= IP6OAF_NO_CELLULAR;
182	if (INP_NO_EXPENSIVE(in6p))
183		ip6oa.ip6oa_flags |= IP6OAF_NO_EXPENSIVE;
184	if (INP_AWDL_UNRESTRICTED(in6p))
185		ip6oa.ip6oa_flags |= IP6OAF_AWDL_UNRESTRICTED;
186
187	if (control) {
188		msc = mbuf_service_class_from_control(control);
189		if ((error = ip6_setpktopts(control, &opt,
190		    NULL, IPPROTO_UDP)) != 0)
191			goto release;
192		optp = &opt;
193	} else
194		optp = in6p->in6p_outputopts;
195
196	if (addr6) {
197		/*
198		 * IPv4 version of udp_output calls in_pcbconnect in this case,
199		 * which has its costs.
200		 *
201		 * Since we saw no essential reason for calling in_pcbconnect,
202		 * we get rid of such kind of logic, and call in6_selectsrc
203		 * and in6_pcbsetport in order to fill in the local address
204		 * and the local port.
205		 */
206		struct sockaddr_in6 *sin6 =
207		    (struct sockaddr_in6 *)(void *)addr6;
208
209		if (sin6->sin6_port == 0) {
210			error = EADDRNOTAVAIL;
211			goto release;
212		}
213
214		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
215			/* how about ::ffff:0.0.0.0 case? */
216			error = EISCONN;
217			goto release;
218		}
219
220		/* protect *sin6 from overwrites */
221		tmp = *sin6;
222		sin6 = &tmp;
223
224		faddr = &sin6->sin6_addr;
225		fport = sin6->sin6_port; /* allow 0 port */
226
227		if (IN6_IS_ADDR_V4MAPPED(faddr)) {
228			if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY)) {
229				/*
230				 * I believe we should explicitly discard the
231				 * packet when mapped addresses are disabled,
232				 * rather than send the packet as an IPv6 one.
233				 * If we chose the latter approach, the packet
234				 * might be sent out on the wire based on the
235				 * default route, the situation which we'd
236				 * probably want to avoid.
237				 * (20010421 jinmei@kame.net)
238				 */
239				error = EINVAL;
240				goto release;
241			} else {
242				af = AF_INET;
243			}
244		}
245
246		/* KAME hack: embed scopeid */
247		if (in6_embedscope(&sin6->sin6_addr, sin6, in6p, NULL,
248		    optp) != 0) {
249			error = EINVAL;
250			goto release;
251		}
252
253		if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
254			laddr = in6_selectsrc(sin6, optp,
255			    in6p, &in6p->in6p_route, NULL, &storage,
256			    ip6oa.ip6oa_boundif, &error);
257		} else
258			laddr = &in6p->in6p_laddr;	/* XXX */
259		if (laddr == NULL) {
260			if (error == 0)
261				error = EADDRNOTAVAIL;
262			goto release;
263		}
264		if (in6p->in6p_lport == 0 &&
265		    (error = in6_pcbsetport(laddr, in6p, p, 0)) != 0)
266			goto release;
267	} else {
268		if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
269			error = ENOTCONN;
270			goto release;
271		}
272		if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr)) {
273			if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY)) {
274				/*
275				 * XXX: this case would happen when the
276				 * application sets the V6ONLY flag after
277				 * connecting the foreign address.
278				 * Such applications should be fixed,
279				 * so we bark here.
280				 */
281				log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
282				    "option was set for a connected socket\n");
283				error = EINVAL;
284				goto release;
285			} else
286				af = AF_INET;
287		}
288		laddr = &in6p->in6p_laddr;
289		faddr = &in6p->in6p_faddr;
290		fport = in6p->in6p_fport;
291	}
292
293	if (in6p->inp_flowhash == 0)
294		in6p->inp_flowhash = inp_calc_flowhash(in6p);
295	/* update flowinfo - RFC 6437 */
296	if (in6p->inp_flow == 0 && in6p->in6p_flags & IN6P_AUTOFLOWLABEL) {
297		in6p->inp_flow &= ~IPV6_FLOWLABEL_MASK;
298		in6p->inp_flow |=
299		    (htonl(in6p->inp_flowhash) & IPV6_FLOWLABEL_MASK);
300	}
301
302	if (af == AF_INET)
303		hlen = sizeof (struct ip);
304
305	/*
306	 * Calculate data length and get a mbuf
307	 * for UDP and IP6 headers.
308	 */
309	M_PREPEND(m, hlen + sizeof (struct udphdr), M_DONTWAIT);
310	if (m == 0) {
311		error = ENOBUFS;
312		goto release;
313	}
314
315	/*
316	 * Stuff checksum and output datagram.
317	 */
318	udp6 = (struct udphdr *)(void *)(mtod(m, caddr_t) + hlen);
319	udp6->uh_sport = in6p->in6p_lport; /* lport is always set in the PCB */
320	udp6->uh_dport = fport;
321	if (plen <= 0xffff)
322		udp6->uh_ulen = htons((u_short)plen);
323	else
324		udp6->uh_ulen = 0;
325	udp6->uh_sum = 0;
326
327	switch (af) {
328	case AF_INET6:
329		ip6 = mtod(m, struct ip6_hdr *);
330		ip6->ip6_flow	= in6p->inp_flow & IPV6_FLOWINFO_MASK;
331		ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
332		ip6->ip6_vfc	|= IPV6_VERSION;
333#if 0		/* ip6_plen will be filled in ip6_output. */
334		ip6->ip6_plen	= htons((u_short)plen);
335#endif
336		ip6->ip6_nxt	= IPPROTO_UDP;
337		ip6->ip6_hlim	= in6_selecthlim(in6p, in6p->in6p_route.ro_rt ?
338		    in6p->in6p_route.ro_rt->rt_ifp : NULL);
339		ip6->ip6_src	= *laddr;
340		ip6->ip6_dst	= *faddr;
341
342		udp6->uh_sum = in6_pseudo(laddr, faddr,
343		    htonl(plen + IPPROTO_UDP));
344		m->m_pkthdr.csum_flags = CSUM_UDPIPV6;
345		m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
346
347		if (!IN6_IS_ADDR_UNSPECIFIED(laddr))
348			ip6oa.ip6oa_flags |= IP6OAF_BOUND_SRCADDR;
349
350		flags = IPV6_OUTARGS;
351
352		udp6stat.udp6s_opackets++;
353
354#if NECP
355		{
356			necp_kernel_policy_id policy_id;
357			if (!necp_socket_is_allowed_to_send_recv_v6(in6p, in6p->in6p_lport, fport, laddr, faddr, NULL, &policy_id)) {
358				error = EHOSTUNREACH;
359				goto release;
360			}
361
362			necp_mark_packet_from_socket(m, in6p, policy_id);
363		}
364#endif /* NECP */
365
366#if IPSEC
367		if (in6p->in6p_sp != NULL && ipsec_setsocket(m, so) != 0) {
368			error = ENOBUFS;
369			goto release;
370		}
371#endif /*IPSEC*/
372
373		/* In case of IPv4-mapped address used in previous send */
374		if (ROUTE_UNUSABLE(&in6p->in6p_route) ||
375		    rt_key(in6p->in6p_route.ro_rt)->sa_family != AF_INET6)
376			ROUTE_RELEASE(&in6p->in6p_route);
377
378		/* Copy the cached route and take an extra reference */
379		in6p_route_copyout(in6p, &ro);
380
381		set_packet_service_class(m, so, msc, PKT_SCF_IPV6);
382
383		m->m_pkthdr.pkt_flowsrc = FLOWSRC_INPCB;
384		m->m_pkthdr.pkt_flowid = in6p->inp_flowhash;
385		m->m_pkthdr.pkt_proto = IPPROTO_UDP;
386		m->m_pkthdr.pkt_flags |= (PKTF_FLOW_ID | PKTF_FLOW_LOCALSRC);
387		if (flowadv)
388			m->m_pkthdr.pkt_flags |= PKTF_FLOW_ADV;
389
390		im6o = in6p->in6p_moptions;
391		if (im6o != NULL) {
392			IM6O_LOCK(im6o);
393			IM6O_ADDREF_LOCKED(im6o);
394			if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst) &&
395			    im6o->im6o_multicast_ifp != NULL) {
396				in6p->in6p_last_outifp =
397				    im6o->im6o_multicast_ifp;
398			}
399			IM6O_UNLOCK(im6o);
400		}
401
402		in6p->inp_sndinprog_cnt++;
403
404		socket_unlock(so, 0);
405		error = ip6_output(m, optp, &ro, flags, im6o, NULL, &ip6oa);
406		m = NULL;
407		socket_lock(so, 0);
408
409		if (im6o != NULL)
410			IM6O_REMREF(im6o);
411
412		if (error == 0 && nstat_collect) {
413			boolean_t cell, wifi, wired;
414
415			if (in6p->in6p_route.ro_rt != NULL) {
416				cell = IFNET_IS_CELLULAR(in6p->in6p_route.
417				    ro_rt->rt_ifp);
418				wifi = (!cell && IFNET_IS_WIFI(in6p->in6p_route.
419				    ro_rt->rt_ifp));
420				wired = (!wifi && IFNET_IS_WIRED(in6p->in6p_route.
421				    ro_rt->rt_ifp));
422			} else {
423				cell = wifi = wired = FALSE;
424			}
425			INP_ADD_STAT(in6p, cell, wifi, wired, txpackets, 1);
426			INP_ADD_STAT(in6p, cell, wifi, wired, txbytes, ulen);
427		}
428
429		if (flowadv && (adv->code == FADV_FLOW_CONTROLLED ||
430		    adv->code == FADV_SUSPENDED)) {
431			/*
432			 * Return an error to indicate
433			 * that the packet has been dropped.
434			 */
435			error = ENOBUFS;
436			inp_set_fc_state(in6p, adv->code);
437		}
438
439		VERIFY(in6p->inp_sndinprog_cnt > 0);
440		if ( --in6p->inp_sndinprog_cnt == 0)
441			in6p->inp_flags &= ~(INP_FC_FEEDBACK);
442
443		/* Synchronize PCB cached route */
444		in6p_route_copyin(in6p, &ro);
445
446		if (in6p->in6p_route.ro_rt != NULL) {
447			struct rtentry *rt = in6p->in6p_route.ro_rt;
448			struct ifnet *outif;
449
450			if (rt->rt_flags & RTF_MULTICAST)
451				rt = NULL;	/* unusable */
452
453			/*
454			 * Always discard the cached route for unconnected
455			 * socket or if it is a multicast route.
456			 */
457			if (rt == NULL)
458				ROUTE_RELEASE(&in6p->in6p_route);
459
460			/*
461			 * If the destination route is unicast, update outif
462			 * with that of the route interface used by IP.
463			 */
464			if (rt != NULL &&
465			    (outif = rt->rt_ifp) != in6p->in6p_last_outifp)
466				in6p->in6p_last_outifp = outif;
467		} else {
468			ROUTE_RELEASE(&in6p->in6p_route);
469		}
470
471		/*
472		 * If output interface was cellular/expensive, and this
473		 * socket is denied access to it, generate an event.
474		 */
475		if (error != 0 && (ip6oa.ip6oa_retflags & IP6OARF_IFDENIED) &&
476		    (INP_NO_CELLULAR(in6p) || INP_NO_EXPENSIVE(in6p)))
477			soevent(in6p->inp_socket, (SO_FILT_HINT_LOCKED|
478			    SO_FILT_HINT_IFDENIED));
479		break;
480	case AF_INET:
481		error = EAFNOSUPPORT;
482		goto release;
483	}
484	goto releaseopt;
485
486release:
487	if (m != NULL)
488		m_freem(m);
489
490releaseopt:
491	if (control != NULL) {
492		if (optp == &opt)
493			ip6_clearpktopts(optp, -1);
494		m_freem(control);
495	}
496	return (error);
497}
498