1/*	$OpenBSD: udp6_output.c,v 1.65 2024/04/17 20:48:51 bluhm Exp $	*/
2/*	$KAME: udp6_output.c,v 1.21 2001/02/07 11:51:54 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
62#include "pf.h"
63
64#include <sys/param.h>
65#include <sys/mbuf.h>
66#include <sys/socket.h>
67#include <sys/socketvar.h>
68#include <sys/errno.h>
69#include <sys/stat.h>
70#include <sys/systm.h>
71#include <sys/syslog.h>
72
73#include <net/if.h>
74#include <net/if_var.h>
75#include <net/route.h>
76#if NPF > 0
77#include <net/pfvar.h>
78#endif
79
80#include <netinet/in.h>
81#include <netinet6/in6_var.h>
82#include <netinet/ip.h>
83#include <netinet/ip_var.h>
84#include <netinet/in_pcb.h>
85#include <netinet/udp.h>
86#include <netinet/udp_var.h>
87#include <netinet/ip6.h>
88#include <netinet6/ip6_var.h>
89#include <netinet/icmp6.h>
90
91/*
92 * UDP protocol implementation.
93 * Per RFC 768, August, 1980.
94 */
95int
96udp6_output(struct inpcb *inp, struct mbuf *m, struct mbuf *addr6,
97	struct mbuf *control)
98{
99	u_int32_t ulen = m->m_pkthdr.len;
100	u_int32_t plen = sizeof(struct udphdr) + ulen;
101	int error = 0, priv = 0, hlen, flags;
102	struct ip6_hdr *ip6;
103	struct udphdr *udp6;
104	const struct in6_addr *laddr, *faddr;
105	struct ip6_pktopts *optp, opt;
106	struct sockaddr_in6 tmp, valid;
107	struct proc *p = curproc;	/* XXX */
108	u_short fport;
109
110	if ((inp->inp_socket->so_state & SS_PRIV) != 0)
111		priv = 1;
112	if (control) {
113		if ((error = ip6_setpktopts(control, &opt,
114		    inp->inp_outputopts6, priv, IPPROTO_UDP)) != 0)
115			goto release;
116		optp = &opt;
117	} else
118		optp = inp->inp_outputopts6;
119
120	if (addr6) {
121		struct sockaddr_in6 *sin6;
122
123		if ((error = in6_nam2sin6(addr6, &sin6)))
124			goto release;
125		if (sin6->sin6_port == 0) {
126			error = EADDRNOTAVAIL;
127			goto release;
128		}
129		if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
130			error = EADDRNOTAVAIL;
131			goto release;
132		}
133		if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6)) {
134			error = EISCONN;
135			goto release;
136		}
137
138		/* protect *sin6 from overwrites */
139		tmp = *sin6;
140		sin6 = &tmp;
141
142		faddr = &sin6->sin6_addr;
143		fport = sin6->sin6_port; /* allow 0 port */
144
145		/* KAME hack: embed scopeid */
146		if (in6_embedscope(&sin6->sin6_addr, sin6,
147		    inp->inp_outputopts6, inp->inp_moptions6) != 0) {
148			error = EINVAL;
149			goto release;
150		}
151
152		error = in6_pcbselsrc(&laddr, sin6, inp, optp);
153		if (error)
154			goto release;
155
156		if (inp->inp_lport == 0){
157			error = in_pcbbind(inp, NULL, p);
158			if (error)
159				goto release;
160		}
161
162		if (!IN6_IS_ADDR_UNSPECIFIED(&inp->inp_laddr6) &&
163		    !IN6_ARE_ADDR_EQUAL(&inp->inp_laddr6, laddr)) {
164			valid.sin6_addr = *laddr;
165			valid.sin6_port = inp->inp_lport;
166			valid.sin6_scope_id = 0;
167			valid.sin6_family = AF_INET6;
168			valid.sin6_len = sizeof(valid);
169			error = in6_pcbaddrisavail(inp, &valid, 0, p);
170			if (error)
171				goto release;
172		}
173	} else {
174		if (IN6_IS_ADDR_UNSPECIFIED(&inp->inp_faddr6)) {
175			error = ENOTCONN;
176			goto release;
177		}
178		laddr = &inp->inp_laddr6;
179		faddr = &inp->inp_faddr6;
180		fport = inp->inp_fport;
181	}
182
183	hlen = sizeof(struct ip6_hdr);
184
185	/*
186	 * Calculate data length and get a mbuf
187	 * for UDP and IP6 headers.
188	 */
189	M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
190	if (m == NULL) {
191		error = ENOBUFS;
192		goto releaseopt;
193	}
194
195	/*
196	 * Stuff checksum and output datagram.
197	 */
198	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
199	udp6->uh_sport = inp->inp_lport; /* lport is always set in the PCB */
200	udp6->uh_dport = fport;
201	if (plen <= 0xffff)
202		udp6->uh_ulen = htons((u_short)plen);
203	else
204		udp6->uh_ulen = 0;
205	udp6->uh_sum = 0;
206
207	ip6 = mtod(m, struct ip6_hdr *);
208	ip6->ip6_flow	= inp->inp_flowinfo & IPV6_FLOWINFO_MASK;
209	ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
210	ip6->ip6_vfc	|= IPV6_VERSION;
211#if 0	/* ip6_plen will be filled in ip6_output. */
212	ip6->ip6_plen	= htons((u_short)plen);
213#endif
214	ip6->ip6_nxt	= IPPROTO_UDP;
215	ip6->ip6_hlim	= in6_selecthlim(inp);
216	ip6->ip6_src	= *laddr;
217	ip6->ip6_dst	= *faddr;
218
219	m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT;
220
221	flags = 0;
222	if (inp->inp_flags & IN6P_MINMTU)
223		flags |= IPV6_MINMTU;
224
225	udpstat_inc(udps_opackets);
226
227	/* force routing table */
228	m->m_pkthdr.ph_rtableid = inp->inp_rtableid;
229
230#if NPF > 0
231	if (inp->inp_socket->so_state & SS_ISCONNECTED)
232		pf_mbuf_link_inpcb(m, inp);
233#endif
234
235	error = ip6_output(m, optp, &inp->inp_route,
236	    flags, inp->inp_moptions6, &inp->inp_seclevel);
237	goto releaseopt;
238
239release:
240	m_freem(m);
241
242releaseopt:
243	if (control) {
244		ip6_clearpktopts(&opt, -1);
245		m_freem(control);
246	}
247	return (error);
248}
249