xref: /openbsd-src/sys/netinet6/udp6_output.c (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /*	$OpenBSD: udp6_output.c,v 1.30 2014/06/03 13:32:24 mpi 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 <sys/param.h>
63 #include <sys/mbuf.h>
64 #include <sys/protosw.h>
65 #include <sys/socket.h>
66 #include <sys/socketvar.h>
67 #include <sys/errno.h>
68 #include <sys/stat.h>
69 #include <sys/systm.h>
70 #include <sys/syslog.h>
71 
72 #include <net/if.h>
73 #include <net/route.h>
74 #include <net/if_types.h>
75 
76 #include <netinet/in.h>
77 #include <netinet6/in6_var.h>
78 #include <netinet/in_systm.h>
79 #include <netinet/ip.h>
80 #include <netinet/ip_var.h>
81 #include <netinet/in_pcb.h>
82 #include <netinet/udp.h>
83 #include <netinet/udp_var.h>
84 #include <netinet/ip6.h>
85 #include <netinet6/ip6_var.h>
86 #include <netinet/icmp6.h>
87 #include <netinet6/ip6protosw.h>
88 
89 /*
90  * UDP protocol inplementation.
91  * Per RFC 768, August, 1980.
92  */
93 int
94 udp6_output(struct inpcb *in6p, struct mbuf *m, struct mbuf *addr6,
95 	struct mbuf *control)
96 {
97 	u_int32_t ulen = m->m_pkthdr.len;
98 	u_int32_t plen = sizeof(struct udphdr) + ulen;
99 	int error = 0, priv = 0, hlen, flags;
100 	struct ip6_hdr *ip6;
101 	struct udphdr *udp6;
102 	struct in6_addr *laddr, *faddr;
103 	struct ip6_pktopts *optp, opt;
104 	struct sockaddr_in6 tmp;
105 	struct proc *p = curproc;	/* XXX */
106 	struct ifnet *ifp;
107 	u_short fport;
108 
109 	if ((in6p->inp_socket->so_state & SS_PRIV) != 0)
110 		priv = 1;
111 	if (control) {
112 		if ((error = ip6_setpktopts(control, &opt,
113 		    in6p->inp_outputopts6, priv, IPPROTO_UDP)) != 0)
114 			goto release;
115 		optp = &opt;
116 	} else
117 		optp = in6p->inp_outputopts6;
118 
119 	if (addr6) {
120 		struct sockaddr_in6 *sin6 = mtod(addr6, struct sockaddr_in6 *);
121 
122 		if (addr6->m_len != sizeof(*sin6)) {
123 			error = EINVAL;
124 			goto release;
125 		}
126 		if (sin6->sin6_family != AF_INET6) {
127 			error = EAFNOSUPPORT;
128 			goto release;
129 		}
130 		if (sin6->sin6_port == 0) {
131 			error = EADDRNOTAVAIL;
132 			goto release;
133 		}
134 		if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
135 			error = EINVAL;
136 			goto release;
137 		}
138 
139 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->inp_faddr6)) {
140 			error = EISCONN;
141 			goto release;
142 		}
143 
144 		/* protect *sin6 from overwrites */
145 		tmp = *sin6;
146 		sin6 = &tmp;
147 
148 		faddr = &sin6->sin6_addr;
149 		fport = sin6->sin6_port; /* allow 0 port */
150 
151 		/* KAME hack: embed scopeid */
152 		if (in6_embedscope(&sin6->sin6_addr, sin6, in6p, NULL) != 0) {
153 			error = EINVAL;
154 			goto release;
155 		}
156 
157 		error = in6_selectsrc(&laddr, sin6, optp,
158 		    in6p->inp_moptions6, &in6p->inp_route6,
159 		    &in6p->inp_laddr6, in6p->inp_rtableid);
160 		if (error)
161 			goto release;
162 
163 		if (in6p->inp_lport == 0 &&
164 		    (error = in6_pcbsetport(laddr, in6p, p)) != 0)
165 			goto release;
166 	} else {
167 		if (IN6_IS_ADDR_UNSPECIFIED(&in6p->inp_faddr6)) {
168 			error = ENOTCONN;
169 			goto release;
170 		}
171 		laddr = &in6p->inp_laddr6;
172 		faddr = &in6p->inp_faddr6;
173 		fport = in6p->inp_fport;
174 	}
175 
176 	hlen = sizeof(struct ip6_hdr);
177 
178 	/*
179 	 * Calculate data length and get a mbuf
180 	 * for UDP and IP6 headers.
181 	 */
182 	M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
183 	if (m == 0) {
184 		error = ENOBUFS;
185 		goto releaseopt;
186 	}
187 
188 	/*
189 	 * Stuff checksum and output datagram.
190 	 */
191 	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
192 	udp6->uh_sport = in6p->inp_lport; /* lport is always set in the PCB */
193 	udp6->uh_dport = fport;
194 	if (plen <= 0xffff)
195 		udp6->uh_ulen = htons((u_short)plen);
196 	else
197 		udp6->uh_ulen = 0;
198 	udp6->uh_sum = 0;
199 
200 	ip6 = mtod(m, struct ip6_hdr *);
201 	ip6->ip6_flow	= in6p->inp_flowinfo & IPV6_FLOWINFO_MASK;
202 	ip6->ip6_vfc 	&= ~IPV6_VERSION_MASK;
203 	ip6->ip6_vfc 	|= IPV6_VERSION;
204 #if 0	/* ip6_plen will be filled in ip6_output. */
205 	ip6->ip6_plen	= htons((u_short)plen);
206 #endif
207 	ip6->ip6_nxt	= IPPROTO_UDP;
208 	ifp = NULL;
209 	if (in6p->inp_route6.ro_rt &&
210 	    in6p->inp_route6.ro_rt->rt_flags & RTF_UP)
211 		ifp = in6p->inp_route6.ro_rt->rt_ifp;
212 	ip6->ip6_hlim	= in6_selecthlim(in6p, ifp);
213 	ip6->ip6_src	= *laddr;
214 	ip6->ip6_dst	= *faddr;
215 
216 	m->m_pkthdr.csum_flags |= M_UDP_CSUM_OUT;
217 
218 	flags = 0;
219 	if (in6p->inp_flags & IN6P_MINMTU)
220 		flags |= IPV6_MINMTU;
221 
222 	udpstat.udps_opackets++;
223 
224 	/* force routing table */
225 	m->m_pkthdr.ph_rtableid = in6p->inp_rtableid;
226 
227 	error = ip6_output(m, optp, &in6p->inp_route6,
228 	    flags, in6p->inp_moptions6, NULL, in6p);
229 	goto releaseopt;
230 
231 release:
232 	m_freem(m);
233 
234 releaseopt:
235 	if (control) {
236 		ip6_clearpktopts(&opt, -1);
237 		m_freem(control);
238 	}
239 	return (error);
240 }
241