bdae44a844
- Add gre_mtx to protect global softc list. - Hold gre_mtx over various list operations (insert, delete). - Centralize if_gre interface teardown in gre_destroy(), and call this from modevent unload and gre_clone_destroy(). - Export gre_mtx to ip_gre.c, which walks the gre list to look up gre interfaces during encapsulation. Add a wonking comment on how we need some sort of drain/reference count mechanism to keep gre references alive while in use and simultaneous destroy. This commit does not lockdown softc data, which follows in a future commit.
348 lines
8.8 KiB
C
348 lines
8.8 KiB
C
/* $NetBSD: ip_gre.c,v 1.29 2003/09/05 23:02:43 itojun Exp $ */
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/* $FreeBSD$ */
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/*
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* Copyright (c) 1998 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Heiko W.Rupp <hwr@pilhuhn.de>
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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 NetBSD
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* Foundation, Inc. and its contributors.
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* 4. Neither the name of The NetBSD Foundation nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* deencapsulate tunneled packets and send them on
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* output half is in net/if_gre.[ch]
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* This currently handles IPPROTO_GRE, IPPROTO_MOBILE
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*/
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#include "opt_inet.h"
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#include "opt_atalk.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/mbuf.h>
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#include <sys/socket.h>
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#include <sys/socketvar.h>
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#include <sys/protosw.h>
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#include <sys/errno.h>
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#include <sys/time.h>
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#include <sys/kernel.h>
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#include <sys/syslog.h>
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#include <net/bpf.h>
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#include <net/ethernet.h>
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#include <net/if.h>
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#include <net/netisr.h>
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#include <net/route.h>
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#include <net/raw_cb.h>
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#ifdef INET
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#include <netinet/in.h>
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#include <netinet/in_var.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <netinet/ip_var.h>
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#include <netinet/ip_gre.h>
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#include <machine/in_cksum.h>
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#else
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#error ip_gre input without IP?
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#endif
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#ifdef NETATALK
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#include <netatalk/at.h>
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#include <netatalk/at_var.h>
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#include <netatalk/at_extern.h>
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#endif
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/* Needs IP headers. */
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#include <net/if_gre.h>
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#include <machine/stdarg.h>
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#if 1
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void gre_inet_ntoa(struct in_addr in); /* XXX */
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#endif
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static struct gre_softc *gre_lookup(struct mbuf *, u_int8_t);
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static int gre_input2(struct mbuf *, int, u_char);
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/*
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* De-encapsulate a packet and feed it back through ip input (this
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* routine is called whenever IP gets a packet with proto type
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* IPPROTO_GRE and a local destination address).
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* This really is simple
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*/
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void
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#if __STDC__
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gre_input(struct mbuf *m, ...)
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#else
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gre_input(m, va_alist)
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struct mbuf *m;
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va_dcl
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#endif
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{
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int off, ret, proto;
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va_list ap;
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va_start(ap, m);
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off = va_arg(ap, int);
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va_end(ap);
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proto = (mtod(m, struct ip *))->ip_p;
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ret = gre_input2(m, off, proto);
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/*
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* ret == 0 : packet not processed, meaning that
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* no matching tunnel that is up is found.
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* we inject it to raw ip socket to see if anyone picks it up.
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*/
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if (ret == 0)
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rip_input(m, off);
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}
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/*
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* decapsulate.
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* Does the real work and is called from gre_input() (above)
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* returns 0 if packet is not yet processed
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* and 1 if it needs no further processing
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* proto is the protocol number of the "calling" foo_input()
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* routine.
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*/
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static int
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gre_input2(struct mbuf *m ,int hlen, u_char proto)
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{
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struct greip *gip;
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int isr;
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struct gre_softc *sc;
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u_int16_t flags;
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if ((sc = gre_lookup(m, proto)) == NULL) {
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/* No matching tunnel or tunnel is down. */
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return (0);
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}
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if (m->m_len < sizeof(*gip)) {
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m = m_pullup(m, sizeof(*gip));
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if (m == NULL)
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return (ENOBUFS);
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}
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gip = mtod(m, struct greip *);
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sc->sc_if.if_ipackets++;
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sc->sc_if.if_ibytes += m->m_pkthdr.len;
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switch (proto) {
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case IPPROTO_GRE:
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hlen += sizeof(struct gre_h);
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/* process GRE flags as packet can be of variable len */
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flags = ntohs(gip->gi_flags);
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/* Checksum & Offset are present */
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if ((flags & GRE_CP) | (flags & GRE_RP))
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hlen += 4;
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/* We don't support routing fields (variable length) */
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if (flags & GRE_RP)
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return (0);
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if (flags & GRE_KP)
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hlen += 4;
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if (flags & GRE_SP)
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hlen += 4;
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switch (ntohs(gip->gi_ptype)) { /* ethertypes */
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case WCCP_PROTOCOL_TYPE:
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if (sc->wccp_ver == WCCP_V2)
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hlen += 4;
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/* FALLTHROUGH */
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case ETHERTYPE_IP: /* shouldn't need a schednetisr(), */
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isr = NETISR_IP;/* as we are in ip_input */
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break;
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#ifdef NETATALK
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case ETHERTYPE_ATALK:
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isr = NETISR_ATALK1;
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break;
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#endif
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case ETHERTYPE_IPV6:
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/* FALLTHROUGH */
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default: /* others not yet supported */
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return (0);
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}
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break;
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default:
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/* others not yet supported */
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return (0);
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}
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if (hlen > m->m_pkthdr.len) {
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m_freem(m);
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return (EINVAL);
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}
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/* Unlike NetBSD, in FreeBSD m_adj() adjusts m->m_pkthdr.len as well */
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m_adj(m, hlen);
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if (sc->sc_if.if_bpf) {
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u_int32_t af = AF_INET;
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bpf_mtap2(sc->sc_if.if_bpf, &af, sizeof(af), m);
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}
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m->m_pkthdr.rcvif = &sc->sc_if;
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netisr_dispatch(isr, m);
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return (1); /* packet is done, no further processing needed */
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}
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/*
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* input routine for IPPRPOTO_MOBILE
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* This is a little bit diffrent from the other modes, as the
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* encapsulating header was not prepended, but instead inserted
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* between IP header and payload
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*/
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void
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#if __STDC__
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gre_mobile_input(struct mbuf *m, ...)
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#else
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gre_mobile_input(m, va_alist)
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struct mbuf *m;
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va_dcl
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#endif
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{
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struct ip *ip;
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struct mobip_h *mip;
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struct gre_softc *sc;
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int hlen;
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va_list ap;
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int msiz;
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va_start(ap, m);
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hlen = va_arg(ap, int);
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va_end(ap);
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if ((sc = gre_lookup(m, IPPROTO_MOBILE)) == NULL) {
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/* No matching tunnel or tunnel is down. */
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m_freem(m);
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return;
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}
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if (m->m_len < sizeof(*mip)) {
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m = m_pullup(m, sizeof(*mip));
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if (m == NULL)
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return;
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}
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ip = mtod(m, struct ip *);
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mip = mtod(m, struct mobip_h *);
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sc->sc_if.if_ipackets++;
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sc->sc_if.if_ibytes += m->m_pkthdr.len;
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if (ntohs(mip->mh.proto) & MOB_H_SBIT) {
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msiz = MOB_H_SIZ_L;
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mip->mi.ip_src.s_addr = mip->mh.osrc;
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} else
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msiz = MOB_H_SIZ_S;
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if (m->m_len < (ip->ip_hl << 2) + msiz) {
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m = m_pullup(m, (ip->ip_hl << 2) + msiz);
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if (m == NULL)
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return;
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ip = mtod(m, struct ip *);
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mip = mtod(m, struct mobip_h *);
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}
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mip->mi.ip_dst.s_addr = mip->mh.odst;
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mip->mi.ip_p = (ntohs(mip->mh.proto) >> 8);
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if (gre_in_cksum((u_int16_t *)&mip->mh, msiz) != 0) {
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m_freem(m);
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return;
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}
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bcopy((caddr_t)(ip) + (ip->ip_hl << 2) + msiz, (caddr_t)(ip) +
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(ip->ip_hl << 2), m->m_len - msiz - (ip->ip_hl << 2));
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m->m_len -= msiz;
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m->m_pkthdr.len -= msiz;
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/*
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* On FreeBSD, rip_input() supplies us with ip->ip_len
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* already converted into host byteorder and also decreases
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* it by the lengh of IP header, however, ip_input() expects
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* that this field is in the original format (network byteorder
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* and full size of IP packet), so that adjust accordingly.
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*/
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ip->ip_len = htons(ip->ip_len + sizeof(struct ip) - msiz);
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ip->ip_sum = 0;
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ip->ip_sum = in_cksum(m, (ip->ip_hl << 2));
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if (sc->sc_if.if_bpf) {
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u_int32_t af = AF_INET;
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bpf_mtap2(sc->sc_if.if_bpf, &af, sizeof(af), m);
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}
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m->m_pkthdr.rcvif = &sc->sc_if;
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netisr_dispatch(NETISR_IP, m);
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}
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/*
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* Find the gre interface associated with our src/dst/proto set.
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*
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* XXXRW: Need some sort of drain/refcount mechanism so that the softc
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* reference remains valid after it's returned from gre_lookup(). Right
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* now, I'm thinking it should be reference-counted with a gre_dropref()
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* when the caller is done with the softc. This is complicated by how
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* to handle destroying the gre softc; probably using a gre_drain() in
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* in_gre.c during destroy.
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*/
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static struct gre_softc *
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gre_lookup(m, proto)
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struct mbuf *m;
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u_int8_t proto;
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{
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struct ip *ip = mtod(m, struct ip *);
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struct gre_softc *sc;
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mtx_lock(&gre_mtx);
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for (sc = LIST_FIRST(&gre_softc_list); sc != NULL;
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sc = LIST_NEXT(sc, sc_list)) {
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if ((sc->g_dst.s_addr == ip->ip_src.s_addr) &&
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(sc->g_src.s_addr == ip->ip_dst.s_addr) &&
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(sc->g_proto == proto) &&
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((sc->sc_if.if_flags & IFF_UP) != 0)) {
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mtx_unlock(&gre_mtx);
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return (sc);
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}
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}
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mtx_unlock(&gre_mtx);
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return (NULL);
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}
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