1e7a910ca1
the quality of the hash distribution. This does not fix a problem dealing with poor distribution when using lots of IP aliases and listening on the same port on every one of them...some other day perhaps; fixing that requires significant code changes. The use of xor was inspired by David S. Miller <davem@jenolan.rutgers.edu>
365 lines
9.3 KiB
C
365 lines
9.3 KiB
C
/*
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* Copyright (c) 1982, 1986, 1988, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $Id: ip_divert.c,v 1.6 1997/02/22 09:41:31 peter Exp $
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*/
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#include <sys/param.h>
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#include <sys/queue.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.h>
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#include <sys/socket.h>
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#include <sys/protosw.h>
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#include <sys/socketvar.h>
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#include <sys/errno.h>
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#include <sys/systm.h>
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#include <net/if.h>
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#include <net/route.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <netinet/in_pcb.h>
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#include <netinet/in_var.h>
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#include <netinet/ip_var.h>
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/*
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* Divert sockets
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*/
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/*
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* Allocate enough space to hold a full IP packet
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*/
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#define DIVSNDQ (65536 + 100)
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#define DIVRCVQ (65536 + 100)
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/* Global variables */
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/*
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* ip_input() and ip_output() set this secret value before calling us to
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* let us know which divert port to divert a packet to; this is done so
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* we can use the existing prototype for struct protosw's pr_input().
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* This is stored in host order.
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*/
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u_short ip_divert_port;
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/*
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* We set this value to a non-zero port number when we want the call to
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* ip_fw_chk() in ip_input() or ip_output() to ignore ``divert <port>''
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* chain entries. This is stored in host order.
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*/
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u_short ip_divert_ignore;
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/* Internal variables */
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static struct inpcbhead divcb;
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static struct inpcbinfo divcbinfo;
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static u_long div_sendspace = DIVSNDQ; /* XXX sysctl ? */
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static u_long div_recvspace = DIVRCVQ; /* XXX sysctl ? */
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/* Optimization: have this preinitialized */
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static struct sockaddr_in divsrc = { sizeof(divsrc), AF_INET };
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/* Internal functions */
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static int div_output(struct socket *so,
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struct mbuf *m, struct mbuf *addr, struct mbuf *control);
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/*
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* Initialize divert connection block queue.
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*/
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void
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div_init(void)
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{
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LIST_INIT(&divcb);
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divcbinfo.listhead = &divcb;
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/*
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* XXX We don't use the hash list for divert IP, but it's easier
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* to allocate a one entry hash list than it is to check all
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* over the place for hashbase == NULL.
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*/
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divcbinfo.hashbase = hashinit(1, M_PCB, &divcbinfo.hashmask);
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}
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/*
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* Setup generic address and protocol structures
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* for div_input routine, then pass them along with
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* mbuf chain. ip->ip_len is assumed to have had
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* the header length (hlen) subtracted out already.
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* We tell whether the packet was incoming or outgoing
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* by seeing if hlen == 0, which is a hack.
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*/
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void
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div_input(struct mbuf *m, int hlen)
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{
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register struct ip *ip = mtod(m, struct ip *);
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register struct inpcb *inp;
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register struct socket *sa;
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/* Sanity check */
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if (ip_divert_port == 0)
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panic("div_input");
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/* Record divert port */
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divsrc.sin_port = htons(ip_divert_port);
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/* Restore packet header fields */
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ip->ip_len += hlen;
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HTONS(ip->ip_len);
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HTONS(ip->ip_off);
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/* Record receive interface address, if any */
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divsrc.sin_addr.s_addr = 0;
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if (hlen) {
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struct ifaddr *ifa;
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/* More fields affected by ip_input() */
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HTONS(ip->ip_id);
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/* Find IP address for recieve interface */
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for (ifa = m->m_pkthdr.rcvif->if_addrhead.tqh_first;
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ifa != NULL; ifa = ifa->ifa_link.tqe_next) {
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if (ifa->ifa_addr == NULL)
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continue;
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if (ifa->ifa_addr->sa_family != AF_INET)
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continue;
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divsrc.sin_addr =
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((struct sockaddr_in *) ifa->ifa_addr)->sin_addr;
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break;
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}
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}
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/* Put packet on socket queue, if any */
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sa = NULL;
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for (inp = divcb.lh_first; inp != NULL; inp = inp->inp_list.le_next) {
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if (inp->inp_lport == htons(ip_divert_port))
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sa = inp->inp_socket;
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}
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if (sa) {
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if (sbappendaddr(&sa->so_rcv, (struct sockaddr *)&divsrc,
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m, (struct mbuf *)0) == 0)
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m_freem(m);
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else
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sorwakeup(sa);
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} else {
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m_freem(m);
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ipstat.ips_noproto++;
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ipstat.ips_delivered--;
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}
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}
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/*
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* Deliver packet back into the IP processing machinery.
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*
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* If no address specified, or address is 0.0.0.0, send to ip_output();
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* otherwise, send to ip_input() and mark as having been received on
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* the interface with that address.
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*
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* If no address specified, or dest port is 0, allow packet to divert
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* back to this socket; otherwise, don't.
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*/
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static int
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div_output(so, m, addr, control)
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struct socket *so;
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register struct mbuf *m;
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struct mbuf *addr, *control;
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{
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register struct inpcb *const inp = sotoinpcb(so);
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register struct ip *const ip = mtod(m, struct ip *);
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struct sockaddr_in *sin = NULL;
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int error = 0;
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if (control)
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m_freem(control); /* XXX */
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if (addr)
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sin = mtod(addr, struct sockaddr_in *);
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/* Loopback avoidance option */
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ip_divert_ignore = ntohs(inp->inp_lport);
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/* Reinject packet into the system as incoming or outgoing */
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if (!sin || sin->sin_addr.s_addr == 0) {
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/* Don't allow both user specified and setsockopt options,
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and don't allow packet length sizes that will crash */
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if (((ip->ip_hl != (sizeof (*ip) >> 2)) && inp->inp_options) ||
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((u_short)ntohs(ip->ip_len) > m->m_pkthdr.len)) {
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error = EINVAL;
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goto cantsend;
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}
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/* Convert fields to host order for ip_output() */
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NTOHS(ip->ip_len);
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NTOHS(ip->ip_off);
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/* Send packet to output processing */
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ipstat.ips_rawout++; /* XXX */
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error = ip_output(m, inp->inp_options, &inp->inp_route,
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(so->so_options & SO_DONTROUTE) |
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IP_ALLOWBROADCAST | IP_RAWOUTPUT, inp->inp_moptions);
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} else {
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struct ifaddr *ifa;
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/* Find receive interface with the given IP address */
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sin->sin_port = 0;
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if ((ifa = ifa_ifwithaddr((struct sockaddr *) sin)) == 0) {
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error = EADDRNOTAVAIL;
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goto cantsend;
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}
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m->m_pkthdr.rcvif = ifa->ifa_ifp;
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/* Send packet to input processing */
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ip_input(m);
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}
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/* Reset for next time (and other packets) */
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ip_divert_ignore = 0;
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return error;
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cantsend:
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ip_divert_ignore = 0;
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m_freem(m);
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return error;
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}
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/*ARGSUSED*/
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int
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div_usrreq(so, req, m, nam, control)
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register struct socket *so;
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int req;
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struct mbuf *m, *nam, *control;
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{
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register int error = 0;
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register struct inpcb *inp = sotoinpcb(so);
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int s = 0;
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if (inp == NULL && req != PRU_ATTACH) {
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error = EINVAL;
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goto release;
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}
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switch (req) {
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case PRU_ATTACH:
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if (inp)
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panic("div_attach");
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if ((so->so_state & SS_PRIV) == 0) {
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error = EACCES;
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break;
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}
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if ((error = soreserve(so, div_sendspace, div_recvspace)) ||
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(error = in_pcballoc(so, &divcbinfo)))
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break;
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inp = (struct inpcb *)so->so_pcb;
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inp->inp_ip.ip_p = (int)nam; /* XXX */
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inp->inp_flags |= INP_HDRINCL;
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/* The socket is always "connected" because
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we always know "where" to send the packet */
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so->so_state |= SS_ISCONNECTED;
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break;
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case PRU_DISCONNECT:
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if ((so->so_state & SS_ISCONNECTED) == 0) {
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error = ENOTCONN;
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break;
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}
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/* FALLTHROUGH */
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case PRU_ABORT:
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soisdisconnected(so);
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/* FALLTHROUGH */
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case PRU_DETACH:
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if (inp == 0)
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panic("div_detach");
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in_pcbdetach(inp);
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break;
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case PRU_BIND:
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s = splnet();
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error = in_pcbbind(inp, nam);
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splx(s);
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break;
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/*
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* Mark the connection as being incapable of further input.
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*/
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case PRU_SHUTDOWN:
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socantsendmore(so);
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break;
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case PRU_SEND:
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/* Packet must have a header (but that's about it) */
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if (m->m_len < sizeof (struct ip) ||
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(m = m_pullup(m, sizeof (struct ip))) == 0) {
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ipstat.ips_toosmall++;
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error = EINVAL;
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break;
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}
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/* Send packet */
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error = div_output(so, m, nam, control);
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m = NULL;
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break;
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case PRU_SOCKADDR:
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in_setsockaddr(so, nam);
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break;
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case PRU_SENSE:
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/*
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* stat: don't bother with a blocksize.
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*/
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return (0);
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/*
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* Not supported.
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*/
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case PRU_CONNECT:
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case PRU_CONNECT2:
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case PRU_CONTROL:
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case PRU_RCVOOB:
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case PRU_RCVD:
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case PRU_LISTEN:
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case PRU_ACCEPT:
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case PRU_SENDOOB:
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case PRU_PEERADDR:
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error = EOPNOTSUPP;
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break;
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default:
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panic("div_usrreq");
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}
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release:
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if (m)
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m_freem(m);
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return (error);
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}
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