xref: /openbsd-src/sys/netinet6/udp6_output.c (revision a0747c9f67a4ae71ccb71e62a28d1ea19e06a63c)
1 /*	$OpenBSD: udp6_output.c,v 1.57 2021/03/10 10:21:49 jsg 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/protosw.h>
67 #include <sys/socket.h>
68 #include <sys/socketvar.h>
69 #include <sys/errno.h>
70 #include <sys/stat.h>
71 #include <sys/systm.h>
72 #include <sys/syslog.h>
73 
74 #include <net/if.h>
75 #include <net/if_var.h>
76 #include <net/route.h>
77 #if NPF > 0
78 #include <net/pfvar.h>
79 #endif
80 
81 #include <netinet/in.h>
82 #include <netinet6/in6_var.h>
83 #include <netinet/ip.h>
84 #include <netinet/ip_var.h>
85 #include <netinet/in_pcb.h>
86 #include <netinet/udp.h>
87 #include <netinet/udp_var.h>
88 #include <netinet/ip6.h>
89 #include <netinet6/ip6_var.h>
90 #include <netinet/icmp6.h>
91 #include <netinet6/ip6protosw.h>
92 
93 /*
94  * UDP protocol implementation.
95  * Per RFC 768, August, 1980.
96  */
97 int
98 udp6_output(struct inpcb *in6p, struct mbuf *m, struct mbuf *addr6,
99 	struct mbuf *control)
100 {
101 	u_int32_t ulen = m->m_pkthdr.len;
102 	u_int32_t plen = sizeof(struct udphdr) + ulen;
103 	int error = 0, priv = 0, hlen, flags;
104 	struct ip6_hdr *ip6;
105 	struct udphdr *udp6;
106 	struct in6_addr *laddr, *faddr;
107 	struct ip6_pktopts *optp, opt;
108 	struct sockaddr_in6 tmp, valid;
109 	struct proc *p = curproc;	/* XXX */
110 	u_short fport;
111 
112 	if ((in6p->inp_socket->so_state & SS_PRIV) != 0)
113 		priv = 1;
114 	if (control) {
115 		if ((error = ip6_setpktopts(control, &opt,
116 		    in6p->inp_outputopts6, priv, IPPROTO_UDP)) != 0)
117 			goto release;
118 		optp = &opt;
119 	} else
120 		optp = in6p->inp_outputopts6;
121 
122 	if (addr6) {
123 		struct sockaddr_in6 *sin6;
124 
125 		if ((error = in6_nam2sin6(addr6, &sin6)))
126 			goto release;
127 		if (sin6->sin6_port == 0) {
128 			error = EADDRNOTAVAIL;
129 			goto release;
130 		}
131 		if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
132 			error = EADDRNOTAVAIL;
133 			goto release;
134 		}
135 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->inp_faddr6)) {
136 			error = EISCONN;
137 			goto release;
138 		}
139 
140 		/* protect *sin6 from overwrites */
141 		tmp = *sin6;
142 		sin6 = &tmp;
143 
144 		faddr = &sin6->sin6_addr;
145 		fport = sin6->sin6_port; /* allow 0 port */
146 
147 		/* KAME hack: embed scopeid */
148 		if (in6_embedscope(&sin6->sin6_addr, sin6, in6p) != 0) {
149 			error = EINVAL;
150 			goto release;
151 		}
152 
153 		error = in6_pcbselsrc(&laddr, sin6, in6p, optp);
154 		if (error)
155 			goto release;
156 
157 		if (in6p->inp_lport == 0){
158 			error = in_pcbbind(in6p, NULL, p);
159 			if (error)
160 				goto release;
161 		}
162 
163 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->inp_laddr6) &&
164 		    !IN6_ARE_ADDR_EQUAL(&in6p->inp_laddr6, laddr)) {
165 			valid.sin6_addr = *laddr;
166 			valid.sin6_port = in6p->inp_lport;
167 			valid.sin6_scope_id = 0;
168 			valid.sin6_family = AF_INET6;
169 			valid.sin6_len = sizeof(valid);
170 			error = in6_pcbaddrisavail(in6p, &valid, 0, p);
171 			if (error)
172 				goto release;
173 		}
174 	} else {
175 		if (IN6_IS_ADDR_UNSPECIFIED(&in6p->inp_faddr6)) {
176 			error = ENOTCONN;
177 			goto release;
178 		}
179 		laddr = &in6p->inp_laddr6;
180 		faddr = &in6p->inp_faddr6;
181 		fport = in6p->inp_fport;
182 	}
183 
184 	hlen = sizeof(struct ip6_hdr);
185 
186 	/*
187 	 * Calculate data length and get a mbuf
188 	 * for UDP and IP6 headers.
189 	 */
190 	M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
191 	if (m == NULL) {
192 		error = ENOBUFS;
193 		goto releaseopt;
194 	}
195 
196 	/*
197 	 * Stuff checksum and output datagram.
198 	 */
199 	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
200 	udp6->uh_sport = in6p->inp_lport; /* lport is always set in the PCB */
201 	udp6->uh_dport = fport;
202 	if (plen <= 0xffff)
203 		udp6->uh_ulen = htons((u_short)plen);
204 	else
205 		udp6->uh_ulen = 0;
206 	udp6->uh_sum = 0;
207 
208 	ip6 = mtod(m, struct ip6_hdr *);
209 	ip6->ip6_flow	= in6p->inp_flowinfo & IPV6_FLOWINFO_MASK;
210 	ip6->ip6_vfc	&= ~IPV6_VERSION_MASK;
211 	ip6->ip6_vfc	|= IPV6_VERSION;
212 #if 0	/* ip6_plen will be filled in ip6_output. */
213 	ip6->ip6_plen	= htons((u_short)plen);
214 #endif
215 	ip6->ip6_nxt	= IPPROTO_UDP;
216 	ip6->ip6_hlim	= in6_selecthlim(in6p);
217 	ip6->ip6_src	= *laddr;
218 	ip6->ip6_dst	= *faddr;
219 
220 	m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT;
221 
222 	flags = 0;
223 	if (in6p->inp_flags & IN6P_MINMTU)
224 		flags |= IPV6_MINMTU;
225 
226 	udpstat_inc(udps_opackets);
227 
228 	/* force routing table */
229 	m->m_pkthdr.ph_rtableid = in6p->inp_rtableid;
230 
231 #if NPF > 0
232 	if (in6p->inp_socket->so_state & SS_ISCONNECTED)
233 		pf_mbuf_link_inpcb(m, in6p);
234 #endif
235 
236 	error = ip6_output(m, optp, &in6p->inp_route6,
237 	    flags, in6p->inp_moptions6, in6p);
238 	goto releaseopt;
239 
240 release:
241 	m_freem(m);
242 
243 releaseopt:
244 	if (control) {
245 		ip6_clearpktopts(&opt, -1);
246 		m_freem(control);
247 	}
248 	return (error);
249 }
250