xref: /openbsd-src/sys/netinet6/udp6_output.c (revision e5157e49389faebcb42b7237d55fbf096d9c2523)
1 /*	$OpenBSD: udp6_output.c,v 1.32 2014/11/09 22:05:08 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/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/route.h>
76 #include <net/if_types.h>
77 
78 #include <netinet/in.h>
79 #include <netinet6/in6_var.h>
80 #include <netinet/ip.h>
81 #include <netinet/ip_var.h>
82 #include <netinet/in_pcb.h>
83 #include <netinet/udp.h>
84 #include <netinet/udp_var.h>
85 #include <netinet/ip6.h>
86 #include <netinet6/ip6_var.h>
87 #include <netinet/icmp6.h>
88 #include <netinet6/ip6protosw.h>
89 
90 /*
91  * UDP protocol inplementation.
92  * Per RFC 768, August, 1980.
93  */
94 int
95 udp6_output(struct inpcb *in6p, struct mbuf *m, struct mbuf *addr6,
96 	struct mbuf *control)
97 {
98 	u_int32_t ulen = m->m_pkthdr.len;
99 	u_int32_t plen = sizeof(struct udphdr) + ulen;
100 	int error = 0, priv = 0, hlen, flags;
101 	struct ip6_hdr *ip6;
102 	struct udphdr *udp6;
103 	struct in6_addr *laddr, *faddr;
104 	struct ip6_pktopts *optp, opt;
105 	struct sockaddr_in6 tmp;
106 	struct proc *p = curproc;	/* XXX */
107 	struct ifnet *ifp;
108 	u_short fport;
109 
110 	if ((in6p->inp_socket->so_state & SS_PRIV) != 0)
111 		priv = 1;
112 	if (control) {
113 		if ((error = ip6_setpktopts(control, &opt,
114 		    in6p->inp_outputopts6, priv, IPPROTO_UDP)) != 0)
115 			goto release;
116 		optp = &opt;
117 	} else
118 		optp = in6p->inp_outputopts6;
119 
120 	if (addr6) {
121 		struct sockaddr_in6 *sin6 = mtod(addr6, struct sockaddr_in6 *);
122 
123 		if (addr6->m_len != sizeof(*sin6)) {
124 			error = EINVAL;
125 			goto release;
126 		}
127 		if (sin6->sin6_family != AF_INET6) {
128 			error = EAFNOSUPPORT;
129 			goto release;
130 		}
131 		if (sin6->sin6_port == 0) {
132 			error = EADDRNOTAVAIL;
133 			goto release;
134 		}
135 		if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
136 			error = EINVAL;
137 			goto release;
138 		}
139 
140 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->inp_faddr6)) {
141 			error = EISCONN;
142 			goto release;
143 		}
144 
145 		/* protect *sin6 from overwrites */
146 		tmp = *sin6;
147 		sin6 = &tmp;
148 
149 		faddr = &sin6->sin6_addr;
150 		fport = sin6->sin6_port; /* allow 0 port */
151 
152 		/* KAME hack: embed scopeid */
153 		if (in6_embedscope(&sin6->sin6_addr, sin6, in6p, NULL) != 0) {
154 			error = EINVAL;
155 			goto release;
156 		}
157 
158 		error = in6_selectsrc(&laddr, sin6, optp,
159 		    in6p->inp_moptions6, &in6p->inp_route6,
160 		    &in6p->inp_laddr6, in6p->inp_rtableid);
161 		if (error)
162 			goto release;
163 
164 		if (in6p->inp_lport == 0 &&
165 		    (error = in6_pcbsetport(laddr, in6p, p)) != 0)
166 			goto release;
167 	} else {
168 		if (IN6_IS_ADDR_UNSPECIFIED(&in6p->inp_faddr6)) {
169 			error = ENOTCONN;
170 			goto release;
171 		}
172 		laddr = &in6p->inp_laddr6;
173 		faddr = &in6p->inp_faddr6;
174 		fport = in6p->inp_fport;
175 	}
176 
177 	hlen = sizeof(struct ip6_hdr);
178 
179 	/*
180 	 * Calculate data length and get a mbuf
181 	 * for UDP and IP6 headers.
182 	 */
183 	M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
184 	if (m == 0) {
185 		error = ENOBUFS;
186 		goto releaseopt;
187 	}
188 
189 	/*
190 	 * Stuff checksum and output datagram.
191 	 */
192 	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
193 	udp6->uh_sport = in6p->inp_lport; /* lport is always set in the PCB */
194 	udp6->uh_dport = fport;
195 	if (plen <= 0xffff)
196 		udp6->uh_ulen = htons((u_short)plen);
197 	else
198 		udp6->uh_ulen = 0;
199 	udp6->uh_sum = 0;
200 
201 	ip6 = mtod(m, struct ip6_hdr *);
202 	ip6->ip6_flow	= in6p->inp_flowinfo & IPV6_FLOWINFO_MASK;
203 	ip6->ip6_vfc 	&= ~IPV6_VERSION_MASK;
204 	ip6->ip6_vfc 	|= IPV6_VERSION;
205 #if 0	/* ip6_plen will be filled in ip6_output. */
206 	ip6->ip6_plen	= htons((u_short)plen);
207 #endif
208 	ip6->ip6_nxt	= IPPROTO_UDP;
209 	ifp = NULL;
210 	if (in6p->inp_route6.ro_rt &&
211 	    in6p->inp_route6.ro_rt->rt_flags & RTF_UP)
212 		ifp = in6p->inp_route6.ro_rt->rt_ifp;
213 	ip6->ip6_hlim	= in6_selecthlim(in6p, ifp);
214 	ip6->ip6_src	= *laddr;
215 	ip6->ip6_dst	= *faddr;
216 
217 	m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT;
218 
219 	flags = 0;
220 	if (in6p->inp_flags & IN6P_MINMTU)
221 		flags |= IPV6_MINMTU;
222 
223 	udpstat.udps_opackets++;
224 
225 	/* force routing table */
226 	m->m_pkthdr.ph_rtableid = in6p->inp_rtableid;
227 
228 #if NPF > 0
229 	if (in6p->inp_socket->so_state & SS_ISCONNECTED)
230 		m->m_pkthdr.pf.inp = in6p;
231 #endif
232 
233 	error = ip6_output(m, optp, &in6p->inp_route6,
234 	    flags, in6p->inp_moptions6, NULL, in6p);
235 	goto releaseopt;
236 
237 release:
238 	m_freem(m);
239 
240 releaseopt:
241 	if (control) {
242 		ip6_clearpktopts(&opt, -1);
243 		m_freem(control);
244 	}
245 	return (error);
246 }
247