xref: /dragonfly/sys/netinet6/udp6_output.c (revision ab709bfb)
1 /*	$FreeBSD: src/sys/netinet6/udp6_output.c,v 1.1.2.6 2003/01/23 21:06:47 sam Exp $	*/
2 /*	$DragonFly: src/sys/netinet6/udp6_output.c,v 1.9 2008/09/04 09:08:22 hasso Exp $	*/
3 /*	$KAME: udp6_output.c,v 1.31 2001/05/21 16:39:15 jinmei Exp $	*/
4 
5 /*
6  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. Neither the name of the project nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Copyright (c) 1982, 1986, 1989, 1993
36  *	The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. All advertising materials mentioning features or use of this software
47  *    must display the following acknowledgement:
48  *	This product includes software developed by the University of
49  *	California, Berkeley and its contributors.
50  * 4. Neither the name of the University nor the names of its contributors
51  *    may be used to endorse or promote products derived from this software
52  *    without specific prior written permission.
53  *
54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
64  * SUCH DAMAGE.
65  *
66  *	@(#)udp_var.h	8.1 (Berkeley) 6/10/93
67  */
68 
69 #include "opt_ipsec.h"
70 #include "opt_inet.h"
71 #include "opt_inet6.h"
72 
73 #include <sys/param.h>
74 #include <sys/malloc.h>
75 #include <sys/mbuf.h>
76 #include <sys/protosw.h>
77 #include <sys/socket.h>
78 #include <sys/socketvar.h>
79 #include <sys/sysctl.h>
80 #include <sys/errno.h>
81 #include <sys/stat.h>
82 #include <sys/systm.h>
83 #include <sys/proc.h>
84 #include <sys/priv.h>
85 #include <sys/syslog.h>
86 
87 #include <net/if.h>
88 #include <net/route.h>
89 #include <net/if_types.h>
90 
91 #include <netinet/in.h>
92 #include <netinet/in_var.h>
93 #include <netinet/in_systm.h>
94 #include <netinet/ip.h>
95 #include <netinet/ip_var.h>
96 #include <netinet/in_pcb.h>
97 #include <netinet/udp.h>
98 #include <netinet/udp_var.h>
99 #include <netinet/ip6.h>
100 #include <netinet6/ip6_var.h>
101 #include <netinet6/in6_pcb.h>
102 #include <netinet6/udp6_var.h>
103 #include <netinet/icmp6.h>
104 #include <netinet6/ip6protosw.h>
105 
106 #ifdef IPSEC
107 #include <netinet6/ipsec.h>
108 #ifdef INET6
109 #include <netinet6/ipsec6.h>
110 #endif
111 #endif /* IPSEC */
112 
113 #include <net/net_osdep.h>
114 
115 /*
116  * UDP protocol inplementation.
117  * Per RFC 768, August, 1980.
118  */
119 
120 #define in6pcb		inpcb
121 #define udp6stat	udpstat
122 #define udp6s_opackets	udps_opackets
123 
124 int
125 udp6_output(struct in6pcb *in6p, struct mbuf *m, struct sockaddr *addr6,
126 	    struct mbuf *control, struct thread *td)
127 {
128 	u_int32_t ulen = m->m_pkthdr.len;
129 	u_int32_t plen = sizeof(struct udphdr) + ulen;
130 	struct ip6_hdr *ip6;
131 	struct udphdr *udp6;
132 	struct in6_addr *laddr, *faddr;
133 	u_short fport;
134 	int error = 0;
135 	struct ip6_pktopts opt, *stickyopt = in6p->in6p_outputopts;
136 	int priv;
137 	int af = AF_INET6, hlen = sizeof(struct ip6_hdr);
138 	int flags;
139 	struct sockaddr_in6 tmp;
140 
141 	priv = !priv_check(td, PRIV_ROOT);	/* 1 if privileged, 0 if not */
142 	if (control) {
143 		if ((error = ip6_setpktoptions(control, &opt,
144 		    in6p->in6p_outputopts,
145 		    IPPROTO_UDP, priv)) != 0)
146 			goto release;
147 		in6p->in6p_outputopts = &opt;
148 	}
149 
150 	if (addr6) {
151 		/*
152 		 * IPv4 version of udp_output calls in_pcbconnect in this case,
153 		 * which needs splnet and affects performance.
154 		 * Since we saw no essential reason for calling in_pcbconnect,
155 		 * we get rid of such kind of logic, and call in6_selectsrc
156 		 * and in6_pcbsetport in order to fill in the local address
157 		 * and the local port.
158 		 */
159 		struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)addr6;
160 		if (sin6->sin6_port == 0) {
161 			error = EADDRNOTAVAIL;
162 			goto release;
163 		}
164 
165 		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
166 			/* how about ::ffff:0.0.0.0 case? */
167 			error = EISCONN;
168 			goto release;
169 		}
170 		if (!prison_remote_ip(td, (struct sockaddr *)addr6)) {
171 			error = EAFNOSUPPORT; /* IPv4 only jail */
172 			goto release;
173 		}
174 
175 		/* protect *sin6 from overwrites */
176 		tmp = *sin6;
177 		sin6 = &tmp;
178 
179 		faddr = &sin6->sin6_addr;
180 		fport = sin6->sin6_port; /* allow 0 port */
181 
182 		if (IN6_IS_ADDR_V4MAPPED(faddr)) {
183 			if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY)) {
184 				/*
185 				 * I believe we should explicitly discard the
186 				 * packet when mapped addresses are disabled,
187 				 * rather than send the packet as an IPv6 one.
188 				 * If we chose the latter approach, the packet
189 				 * might be sent out on the wire based on the
190 				 * default route, the situation which we'd
191 				 * probably want to avoid.
192 				 * (20010421 jinmei@kame.net)
193 				 */
194 				error = EINVAL;
195 				goto release;
196 			} else
197 				af = AF_INET;
198 		}
199 
200 		/* KAME hack: embed scopeid */
201 		if (in6_embedscope(&sin6->sin6_addr, sin6, in6p, NULL) != 0) {
202 			error = EINVAL;
203 			goto release;
204 		}
205 
206 		if (!IN6_IS_ADDR_V4MAPPED(faddr)) {
207 			laddr = in6_selectsrc(sin6, in6p->in6p_outputopts,
208 					      in6p->in6p_moptions,
209 					      &in6p->in6p_route,
210 					      &in6p->in6p_laddr, &error, NULL);
211 		} else
212 			laddr = &in6p->in6p_laddr;	/* XXX */
213 		if (laddr == NULL) {
214 			if (error == 0)
215 				error = EADDRNOTAVAIL;
216 			goto release;
217 		}
218 		if (in6p->in6p_lport == 0 &&
219 		    (error = in6_pcbsetport(laddr, in6p, td)) != 0)
220 			goto release;
221 	} else {
222 		if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
223 			error = ENOTCONN;
224 			goto release;
225 		}
226 		if (IN6_IS_ADDR_V4MAPPED(&in6p->in6p_faddr)) {
227 			if ((in6p->in6p_flags & IN6P_IPV6_V6ONLY)) {
228 				/*
229 				 * XXX: this case would happen when the
230 				 * application sets the V6ONLY flag after
231 				 * connecting the foreign address.
232 				 * Such applications should be fixed,
233 				 * so we bark here.
234 				 */
235 				log(LOG_INFO, "udp6_output: IPV6_V6ONLY "
236 				    "option was set for a connected socket\n");
237 				error = EINVAL;
238 				goto release;
239 			} else
240 				af = AF_INET;
241 		}
242 		laddr = &in6p->in6p_laddr;
243 		faddr = &in6p->in6p_faddr;
244 		fport = in6p->in6p_fport;
245 	}
246 
247 	if (af == AF_INET)
248 		hlen = sizeof(struct ip);
249 
250 	/*
251 	 * Calculate data length and get a mbuf
252 	 * for UDP and IP6 headers.
253 	 */
254 	M_PREPEND(m, hlen + sizeof(struct udphdr), MB_DONTWAIT);
255 	if (m == 0) {
256 		error = ENOBUFS;
257 		goto release;
258 	}
259 
260 	/*
261 	 * Stuff checksum and output datagram.
262 	 */
263 	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
264 	udp6->uh_sport = in6p->in6p_lport; /* lport is always set in the PCB */
265 	udp6->uh_dport = fport;
266 	if (plen <= 0xffff)
267 		udp6->uh_ulen = htons((u_short)plen);
268 	else
269 		udp6->uh_ulen = 0;
270 	udp6->uh_sum = 0;
271 
272 	switch (af) {
273 	case AF_INET6:
274 		ip6 = mtod(m, struct ip6_hdr *);
275 		ip6->ip6_flow	= in6p->in6p_flowinfo & IPV6_FLOWINFO_MASK;
276 		ip6->ip6_vfc 	&= ~IPV6_VERSION_MASK;
277 		ip6->ip6_vfc 	|= IPV6_VERSION;
278 #if 0				/* ip6_plen will be filled in ip6_output. */
279 		ip6->ip6_plen	= htons((u_short)plen);
280 #endif
281 		ip6->ip6_nxt	= IPPROTO_UDP;
282 		ip6->ip6_hlim	= in6_selecthlim(in6p,
283 						 in6p->in6p_route.ro_rt ?
284 						 in6p->in6p_route.ro_rt->rt_ifp : NULL);
285 		ip6->ip6_src	= *laddr;
286 		ip6->ip6_dst	= *faddr;
287 
288 		if ((udp6->uh_sum = in6_cksum(m, IPPROTO_UDP,
289 				sizeof(struct ip6_hdr), plen)) == 0) {
290 			udp6->uh_sum = 0xffff;
291 		}
292 
293 		flags = 0;
294 
295 		udp6stat.udp6s_opackets++;
296 		error = ip6_output(m, in6p->in6p_outputopts, &in6p->in6p_route,
297 		    flags, in6p->in6p_moptions, NULL, in6p);
298 		break;
299 	case AF_INET:
300 		error = EAFNOSUPPORT;
301 		goto release;
302 	}
303 	goto releaseopt;
304 
305 release:
306 	m_freem(m);
307 
308 releaseopt:
309 	if (control) {
310 		ip6_clearpktopts(in6p->in6p_outputopts, -1);
311 		in6p->in6p_outputopts = stickyopt;
312 		m_freem(control);
313 	}
314 	return (error);
315 }
316