xref: /openbsd-src/sys/netinet6/udp6_output.c (revision ace0f1891f538e34a7abe4c36dddbf6f6515f1bb)
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  */
95 int
udp6_output(struct inpcb * inp,struct mbuf * m,struct mbuf * addr6,struct mbuf * control)96 udp6_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 
239 release:
240 	m_freem(m);
241 
242 releaseopt:
243 	if (control) {
244 		ip6_clearpktopts(&opt, -1);
245 		m_freem(control);
246 	}
247 	return (error);
248 }
249