text: /*	$OpenBSD: udp6_output.c,v 1.16 2008/11/23 13:30:59 claudio Exp $	*/
  /*	$KAME: udp6_output.c,v 1.21 2001/02/07 11:51:54 itojun Exp $	*/
  
  /*
   * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. Neither the name of the project nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   */
  
  /*
   * Copyright (c) 1982, 1986, 1989, 1993
   *	The Regents of the University of California.  All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   *	@(#)udp_var.h	8.1 (Berkeley) 6/10/93
   */
  
  #include <sys/param.h>
  #include <sys/malloc.h>
  #include <sys/mbuf.h>
  #include <sys/protosw.h>
  #include <sys/socket.h>
  #include <sys/socketvar.h>
  #include <sys/errno.h>
  #include <sys/stat.h>
  #include <sys/systm.h>
  #include <sys/proc.h>
  #include <sys/syslog.h>
  
  #include <net/if.h>
  #include <net/route.h>
  #include <net/if_types.h>
  
  #include <netinet/in.h>
  #include <netinet/in_var.h>
  #include <netinet/in_systm.h>
  #include <netinet/ip.h>
  #include <netinet/ip_var.h>
  #include <netinet/in_pcb.h>
  #include <netinet/udp.h>
  #include <netinet/udp_var.h>
  #include <netinet/ip6.h>
  #include <netinet6/ip6_var.h>
  #include <netinet/icmp6.h>
  #include <netinet6/ip6protosw.h>
  
  #include "faith.h"
  
  /*
   * UDP protocol inplementation.
   * Per RFC 768, August, 1980.
   */
  
  #define in6pcb		inpcb
  #define in6p_outputopts	inp_outputopts6
  #define in6p_socket	inp_socket
  #define in6p_faddr	inp_faddr6
  #define in6p_laddr	inp_laddr6
  #define in6p_fport	inp_fport
  #define in6p_lport	inp_lport
  #define in6p_flags	inp_flags
  #define in6p_moptions	inp_moptions6
  #define in6p_route	inp_route6
  #define in6p_flowinfo	inp_flowinfo
  #define udp6stat	udpstat
  #define udp6s_opackets	udps_opackets
  
  int
  udp6_output(struct in6pcb *in6p, struct mbuf *m, struct mbuf *addr6, 
  	struct mbuf *control)
  {
  	u_int32_t ulen = m->m_pkthdr.len;
  	u_int32_t plen = sizeof(struct udphdr) + ulen;
  	struct ip6_hdr *ip6;
  	struct udphdr *udp6;
  	struct	in6_addr *laddr, *faddr;
  	u_short fport;
  	int error = 0;
  	struct ip6_pktopts *optp, opt;
  	int priv;
  	int af, hlen;
  	int flags;
  	struct sockaddr_in6 tmp;
  	struct proc *p = curproc;	/* XXX */
  	struct ifnet *ifp;
  
  	priv = 0;
  	if ((in6p->in6p_socket->so_state & SS_PRIV) != 0)
  		priv = 1;
  	if (control) {
  		if ((error = ip6_setpktopts(control, &opt,
  		    in6p->in6p_outputopts, priv, IPPROTO_UDP)) != 0)
  			goto release;
  		optp = &opt;
  	} else
  		optp = in6p->in6p_outputopts;
  
  	if (addr6) {
  		/*
  		 * IPv4 version of udp_output calls in_pcbconnect in this case,
  		 * which needs splnet and affects performance.
  		 * Since we saw no essential reason for calling in_pcbconnect,
  		 * we get rid of such kind of logic, and call in6_selectsrc
  		 * and in6_pcbsetport in order to fill in the local address
  		 * and the local port.
  		 */
  		struct sockaddr_in6 *sin6 = mtod(addr6, struct sockaddr_in6 *);
  
  		if (addr6->m_len != sizeof(*sin6)) {
  			error = EINVAL;
  			goto release;
  		}
  		if (sin6->sin6_family != AF_INET6) {
  			error = EAFNOSUPPORT;
  			goto release;
  		}
  		if (sin6->sin6_port == 0) {
  			error = EADDRNOTAVAIL;
  			goto release;
  		}
  
  		if (!IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
  			error = EISCONN;
  			goto release;
  		}
  
  		/* protect *sin6 from overwrites */
  		tmp = *sin6;
  		sin6 = &tmp;
  
  		faddr = &sin6->sin6_addr;
  		fport = sin6->sin6_port; /* allow 0 port */
  
  		/* KAME hack: embed scopeid */
  		if (in6_embedscope(&sin6->sin6_addr, sin6, in6p, NULL) != 0) {
  			error = EINVAL;
  			goto release;
  		}
  
  		if (1)	/* we don't support IPv4 mapped address */
  		{
  			laddr = in6_selectsrc(sin6, optp,
  					      in6p->in6p_moptions,
  					      &in6p->in6p_route,
  					      &in6p->in6p_laddr, &error);
  		} else
  			laddr = &in6p->in6p_laddr;	/*XXX*/
  		if (laddr == NULL) {
  			if (error == 0)
  				error = EADDRNOTAVAIL;
  			goto release;
  		}
  		if (in6p->in6p_lport == 0 &&
  		    (error = in6_pcbsetport(laddr, in6p, p)) != 0)
  			goto release;
  	} else {
  		if (IN6_IS_ADDR_UNSPECIFIED(&in6p->in6p_faddr)) {
  			error = ENOTCONN;
  			goto release;
  		}
  		laddr = &in6p->in6p_laddr;
  		faddr = &in6p->in6p_faddr;
  		fport = in6p->in6p_fport;
  	}
  
  	if (1)	/* we don't support IPv4 mapped address */
  	{
  		af = AF_INET6;
  		hlen = sizeof(struct ip6_hdr);
  	} else {
  		af = AF_INET;
  		hlen = sizeof(struct ip);
  	}
  
  	/*
  	 * Calculate data length and get a mbuf
  	 * for UDP and IP6 headers.
  	 */
  	M_PREPEND(m, hlen + sizeof(struct udphdr), M_DONTWAIT);
  	if (m == 0) {
  		error = ENOBUFS;
  		goto release;
  	}
  
  	/*
  	 * Stuff checksum and output datagram.
  	 */
  	udp6 = (struct udphdr *)(mtod(m, caddr_t) + hlen);
  	udp6->uh_sport = in6p->in6p_lport; /* lport is always set in the PCB */
  	udp6->uh_dport = fport;
  	if (plen <= 0xffff)
  		udp6->uh_ulen = htons((u_short)plen);
  	else
  		udp6->uh_ulen = 0;
  	udp6->uh_sum = 0;
  
  	switch (af) {
  	case AF_INET6:
  		ip6 = mtod(m, struct ip6_hdr *);
  		ip6->ip6_flow	= in6p->in6p_flowinfo & IPV6_FLOWINFO_MASK;
  		ip6->ip6_vfc 	&= ~IPV6_VERSION_MASK;
  		ip6->ip6_vfc 	|= IPV6_VERSION;
  #if 0				/* ip6_plen will be filled in ip6_output. */
  		ip6->ip6_plen	= htons((u_short)plen);
  #endif
  		ip6->ip6_nxt	= IPPROTO_UDP;
  		ifp = NULL;
  		if (in6p->in6p_route.ro_rt &&
  		    in6p->in6p_route.ro_rt->rt_flags & RTF_UP)
  			ifp = in6p->in6p_route.ro_rt->rt_ifp;
  		ip6->ip6_hlim	= in6_selecthlim(in6p, ifp);
  		ip6->ip6_src	= *laddr;
  		ip6->ip6_dst	= *faddr;
  
  		if ((udp6->uh_sum = in6_cksum(m, IPPROTO_UDP,
  				sizeof(struct ip6_hdr), plen)) == 0) {
  			udp6->uh_sum = 0xffff;
  		}
  
  		flags = 0;
  		if (in6p->in6p_flags & IN6P_MINMTU)
  			flags |= IPV6_MINMTU;
  
  		udp6stat.udp6s_opackets++;
  		error = ip6_output(m, optp, &in6p->in6p_route,
  			    flags, in6p->in6p_moptions, NULL, in6p);
  		break;
  	case AF_INET:
  		error = EAFNOSUPPORT;
  		goto release;
  	}
  	goto releaseopt;
  
  release:
  	m_freem(m);
  
  releaseopt:
  	if (control) {
  		ip6_clearpktopts(&opt, -1);
  		m_freem(control);
  	}
  	return (error);
  }
  