FreeBSD/Linux Kernel Cross Reference
sys/netinet/ip_mroute.c

     /*-
      * SPDX-License-Identifier: BSD-3-Clause
      *
      * Copyright (c) 1989 Stephen Deering
      * Copyright (c) 1992, 1993
      *      The Regents of the University of California.  All rights reserved.
      *
      * This code is derived from software contributed to Berkeley by
      * Stephen Deering of Stanford University.
     *
     * 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.
     *
     *      @(#)ip_mroute.c 8.2 (Berkeley) 11/15/93
     */
    
    /*
     * IP multicast forwarding procedures
     *
     * Written by David Waitzman, BBN Labs, August 1988.
     * Modified by Steve Deering, Stanford, February 1989.
     * Modified by Mark J. Steiglitz, Stanford, May, 1991
     * Modified by Van Jacobson, LBL, January 1993
     * Modified by Ajit Thyagarajan, PARC, August 1993
     * Modified by Bill Fenner, PARC, April 1995
     * Modified by Ahmed Helmy, SGI, June 1996
     * Modified by George Edmond Eddy (Rusty), ISI, February 1998
     * Modified by Pavlin Radoslavov, USC/ISI, May 1998, August 1999, October 2000
     * Modified by Hitoshi Asaeda, WIDE, August 2000
     * Modified by Pavlin Radoslavov, ICSI, October 2002
     * Modified by Wojciech Macek, Semihalf, May 2021
     *
     * MROUTING Revision: 3.5
     * and PIM-SMv2 and PIM-DM support, advanced API support,
     * bandwidth metering and signaling
     */
    
    /*
     * TODO: Prefix functions with ipmf_.
     * TODO: Maintain a refcount on if_allmulti() in ifnet or in the protocol
     * domain attachment (if_afdata) so we can track consumers of that service.
     * TODO: Deprecate routing socket path for SIOCGETSGCNT and SIOCGETVIFCNT,
     * move it to socket options.
     * TODO: Cleanup LSRR removal further.
     * TODO: Push RSVP stubs into raw_ip.c.
     * TODO: Use bitstring.h for vif set.
     * TODO: Fix mrt6_ioctl dangling ref when dynamically loaded.
     * TODO: Sync ip6_mroute.c with this file.
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include "opt_inet.h"
    #include "opt_mrouting.h"
    
    #define _PIM_VT 1
    
    #include <sys/types.h>
    #include <sys/param.h>
    #include <sys/kernel.h>
    #include <sys/stddef.h>
    #include <sys/condvar.h>
    #include <sys/eventhandler.h>
    #include <sys/lock.h>
    #include <sys/kthread.h>
    #include <sys/ktr.h>
    #include <sys/malloc.h>
    #include <sys/mbuf.h>
    #include <sys/module.h>
    #include <sys/priv.h>
    #include <sys/protosw.h>
    #include <sys/signalvar.h>
    #include <sys/socket.h>
    #include <sys/socketvar.h>
    #include <sys/sockio.h>
    #include <sys/sx.h>
    #include <sys/sysctl.h>
   #include <sys/syslog.h>
   #include <sys/systm.h>
   #include <sys/taskqueue.h>
   #include <sys/time.h>
   #include <sys/counter.h>
   #include <machine/atomic.h>
   
   #include <net/if.h>
   #include <net/if_var.h>
   #include <net/if_types.h>
   #include <net/netisr.h>
   #include <net/route.h>
   #include <net/vnet.h>
   
   #include <netinet/in.h>
   #include <netinet/igmp.h>
   #include <netinet/in_systm.h>
   #include <netinet/in_var.h>
   #include <netinet/ip.h>
   #include <netinet/ip_encap.h>
   #include <netinet/ip_mroute.h>
   #include <netinet/ip_var.h>
   #include <netinet/ip_options.h>
   #include <netinet/pim.h>
   #include <netinet/pim_var.h>
   #include <netinet/udp.h>
   
   #include <machine/in_cksum.h>
   
   #ifndef KTR_IPMF
   #define KTR_IPMF KTR_INET
   #endif
   
   #define         VIFI_INVALID    ((vifi_t) -1)
   
   static MALLOC_DEFINE(M_MRTABLE, "mroutetbl", "multicast forwarding cache");
   
   /*
    * Locking.  We use two locks: one for the virtual interface table and
    * one for the forwarding table.  These locks may be nested in which case
    * the VIF lock must always be taken first.  Note that each lock is used
    * to cover not only the specific data structure but also related data
    * structures.
    */
   
   static struct rwlock mrouter_mtx;
   #define MRW_RLOCK()             rw_rlock(&mrouter_mtx)
   #define MRW_WLOCK()             rw_wlock(&mrouter_mtx)
   #define MRW_RUNLOCK()   rw_runlock(&mrouter_mtx)
   #define MRW_WUNLOCK()   rw_wunlock(&mrouter_mtx)
   #define MRW_UNLOCK()    rw_unlock(&mrouter_mtx)
   #define MRW_LOCK_ASSERT()       rw_assert(&mrouter_mtx, RA_LOCKED)
   #define MRW_WLOCK_ASSERT()      rw_assert(&mrouter_mtx, RA_WLOCKED)
   #define MRW_LOCK_TRY_UPGRADE()  rw_try_upgrade(&mrouter_mtx)
   #define MRW_WOWNED()    rw_wowned(&mrouter_mtx)
   #define MRW_LOCK_INIT()                                         \
           rw_init(&mrouter_mtx, "IPv4 multicast forwarding")
   #define MRW_LOCK_DESTROY()      rw_destroy(&mrouter_mtx)
   
   static int ip_mrouter_cnt;      /* # of vnets with active mrouters */
   static int ip_mrouter_unloading; /* Allow no more V_ip_mrouter sockets */
   
   VNET_PCPUSTAT_DEFINE_STATIC(struct mrtstat, mrtstat);
   VNET_PCPUSTAT_SYSINIT(mrtstat);
   VNET_PCPUSTAT_SYSUNINIT(mrtstat);
   SYSCTL_VNET_PCPUSTAT(_net_inet_ip, OID_AUTO, mrtstat, struct mrtstat,
       mrtstat, "IPv4 Multicast Forwarding Statistics (struct mrtstat, "
       "netinet/ip_mroute.h)");
   
   VNET_DEFINE_STATIC(u_long, mfchash);
   #define V_mfchash               VNET(mfchash)
   #define MFCHASH(a, g)                                                   \
           ((((a).s_addr >> 20) ^ ((a).s_addr >> 10) ^ (a).s_addr ^ \
             ((g).s_addr >> 20) ^ ((g).s_addr >> 10) ^ (g).s_addr) & V_mfchash)
   #define MFCHASHSIZE     256
   
   static u_long mfchashsize;                      /* Hash size */
   VNET_DEFINE_STATIC(u_char *, nexpire);          /* 0..mfchashsize-1 */
   #define V_nexpire               VNET(nexpire)
   VNET_DEFINE_STATIC(LIST_HEAD(mfchashhdr, mfc)*, mfchashtbl);
   #define V_mfchashtbl            VNET(mfchashtbl)
   VNET_DEFINE_STATIC(struct taskqueue *, task_queue);
   #define V_task_queue            VNET(task_queue)
   VNET_DEFINE_STATIC(struct task, task);
   #define V_task          VNET(task)
   
   VNET_DEFINE_STATIC(vifi_t, numvifs);
   #define V_numvifs               VNET(numvifs)
   VNET_DEFINE_STATIC(struct vif *, viftable);
   #define V_viftable              VNET(viftable)
   
   static eventhandler_tag if_detach_event_tag = NULL;
   
   VNET_DEFINE_STATIC(struct callout, expire_upcalls_ch);
   #define V_expire_upcalls_ch     VNET(expire_upcalls_ch)
   
   VNET_DEFINE_STATIC(struct mtx, buf_ring_mtx);
   #define V_buf_ring_mtx  VNET(buf_ring_mtx)
   
   #define         EXPIRE_TIMEOUT  (hz / 4)        /* 4x / second          */
   #define         UPCALL_EXPIRE   6               /* number of timeouts   */
   
   /*
    * Bandwidth meter variables and constants
    */
   static MALLOC_DEFINE(M_BWMETER, "bwmeter", "multicast upcall bw meters");
   
   /*
    * Pending upcalls are stored in a ring which is flushed when
    * full, or periodically
    */
   VNET_DEFINE_STATIC(struct callout, bw_upcalls_ch);
   #define V_bw_upcalls_ch         VNET(bw_upcalls_ch)
   VNET_DEFINE_STATIC(struct buf_ring *, bw_upcalls_ring);
   #define V_bw_upcalls_ring       VNET(bw_upcalls_ring)
   VNET_DEFINE_STATIC(struct mtx, bw_upcalls_ring_mtx);
   #define V_bw_upcalls_ring_mtx           VNET(bw_upcalls_ring_mtx)
   
   #define BW_UPCALLS_PERIOD (hz)          /* periodical flush of bw upcalls */
   
   VNET_PCPUSTAT_DEFINE_STATIC(struct pimstat, pimstat);
   VNET_PCPUSTAT_SYSINIT(pimstat);
   VNET_PCPUSTAT_SYSUNINIT(pimstat);
   
   SYSCTL_NODE(_net_inet, IPPROTO_PIM, pim, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
       "PIM");
   SYSCTL_VNET_PCPUSTAT(_net_inet_pim, PIMCTL_STATS, stats, struct pimstat,
       pimstat, "PIM Statistics (struct pimstat, netinet/pim_var.h)");
   
   static u_long   pim_squelch_wholepkt = 0;
   SYSCTL_ULONG(_net_inet_pim, OID_AUTO, squelch_wholepkt, CTLFLAG_RW,
       &pim_squelch_wholepkt, 0,
       "Disable IGMP_WHOLEPKT notifications if rendezvous point is unspecified");
   
   static const struct encaptab *pim_encap_cookie;
   static int pim_encapcheck(const struct mbuf *, int, int, void *);
   static int pim_input(struct mbuf *, int, int, void *);
   
   extern int in_mcast_loop;
   
   static const struct encap_config ipv4_encap_cfg = {
           .proto = IPPROTO_PIM,
           .min_length = sizeof(struct ip) + PIM_MINLEN,
           .exact_match = 8,
           .check = pim_encapcheck,
           .input = pim_input
   };
   
   /*
    * Note: the PIM Register encapsulation adds the following in front of a
    * data packet:
    *
    * struct pim_encap_hdr {
    *    struct ip ip;
    *    struct pim_encap_pimhdr  pim;
    * }
    *
    */
   
   struct pim_encap_pimhdr {
           struct pim pim;
           uint32_t   flags;
   };
   #define         PIM_ENCAP_TTL   64
   
   static struct ip pim_encap_iphdr = {
   #if BYTE_ORDER == LITTLE_ENDIAN
           sizeof(struct ip) >> 2,
           IPVERSION,
   #else
           IPVERSION,
           sizeof(struct ip) >> 2,
   #endif
           0,                      /* tos */
           sizeof(struct ip),      /* total length */
           0,                      /* id */
           0,                      /* frag offset */
           PIM_ENCAP_TTL,
           IPPROTO_PIM,
           0,                      /* checksum */
   };
   
   static struct pim_encap_pimhdr pim_encap_pimhdr = {
       {
           PIM_MAKE_VT(PIM_VERSION, PIM_REGISTER), /* PIM vers and message type */
           0,                      /* reserved */
           0,                      /* checksum */
       },
       0                           /* flags */
   };
   
   VNET_DEFINE_STATIC(vifi_t, reg_vif_num) = VIFI_INVALID;
   #define V_reg_vif_num           VNET(reg_vif_num)
   VNET_DEFINE_STATIC(struct ifnet *, multicast_register_if);
   #define V_multicast_register_if VNET(multicast_register_if)
   
   /*
    * Private variables.
    */
   
   static u_long   X_ip_mcast_src(int);
   static int      X_ip_mforward(struct ip *, struct ifnet *, struct mbuf *,
                       struct ip_moptions *);
   static int      X_ip_mrouter_done(void);
   static int      X_ip_mrouter_get(struct socket *, struct sockopt *);
   static int      X_ip_mrouter_set(struct socket *, struct sockopt *);
   static int      X_legal_vif_num(int);
   static int      X_mrt_ioctl(u_long, caddr_t, int);
   
   static int      add_bw_upcall(struct bw_upcall *);
   static int      add_mfc(struct mfcctl2 *);
   static int      add_vif(struct vifctl *);
   static void     bw_meter_prepare_upcall(struct bw_meter *, struct timeval *);
   static void     bw_meter_geq_receive_packet(struct bw_meter *, int,
                       struct timeval *);
   static void     bw_upcalls_send(void);
   static int      del_bw_upcall(struct bw_upcall *);
   static int      del_mfc(struct mfcctl2 *);
   static int      del_vif(vifi_t);
   static int      del_vif_locked(vifi_t, struct ifnet **);
   static void     expire_bw_upcalls_send(void *);
   static void     expire_mfc(struct mfc *);
   static void     expire_upcalls(void *);
   static void     free_bw_list(struct bw_meter *);
   static int      get_sg_cnt(struct sioc_sg_req *);
   static int      get_vif_cnt(struct sioc_vif_req *);
   static void     if_detached_event(void *, struct ifnet *);
   static int      ip_mdq(struct mbuf *, struct ifnet *, struct mfc *, vifi_t);
   static int      ip_mrouter_init(struct socket *, int);
   static __inline struct mfc *
                   mfc_find(struct in_addr *, struct in_addr *);
   static void     phyint_send(struct ip *, struct vif *, struct mbuf *);
   static struct mbuf *
                   pim_register_prepare(struct ip *, struct mbuf *);
   static int      pim_register_send(struct ip *, struct vif *,
                       struct mbuf *, struct mfc *);
   static int      pim_register_send_rp(struct ip *, struct vif *,
                       struct mbuf *, struct mfc *);
   static int      pim_register_send_upcall(struct ip *, struct vif *,
                       struct mbuf *, struct mfc *);
   static void     send_packet(struct vif *, struct mbuf *);
   static int      set_api_config(uint32_t *);
   static int      set_assert(int);
   static int      socket_send(struct socket *, struct mbuf *,
                       struct sockaddr_in *);
   
   /*
    * Kernel multicast forwarding API capabilities and setup.
    * If more API capabilities are added to the kernel, they should be
    * recorded in `mrt_api_support'.
    */
   #define MRT_API_VERSION         0x0305
   
   static const int mrt_api_version = MRT_API_VERSION;
   static const uint32_t mrt_api_support = (MRT_MFC_FLAGS_DISABLE_WRONGVIF |
                                            MRT_MFC_FLAGS_BORDER_VIF |
                                            MRT_MFC_RP |
                                            MRT_MFC_BW_UPCALL);
   VNET_DEFINE_STATIC(uint32_t, mrt_api_config);
   #define V_mrt_api_config        VNET(mrt_api_config)
   VNET_DEFINE_STATIC(int, pim_assert_enabled);
   #define V_pim_assert_enabled    VNET(pim_assert_enabled)
   static struct timeval pim_assert_interval = { 3, 0 };   /* Rate limit */
   
   /*
    * Find a route for a given origin IP address and multicast group address.
    * Statistics must be updated by the caller.
    */
   static __inline struct mfc *
   mfc_find(struct in_addr *o, struct in_addr *g)
   {
           struct mfc *rt;
   
           /*
            * Might be called both RLOCK and WLOCK.
            * Check if any, it's caller responsibility
            * to choose correct option.
            */
           MRW_LOCK_ASSERT();
   
           LIST_FOREACH(rt, &V_mfchashtbl[MFCHASH(*o, *g)], mfc_hash) {
                   if (in_hosteq(rt->mfc_origin, *o) &&
                       in_hosteq(rt->mfc_mcastgrp, *g) &&
                       buf_ring_empty(rt->mfc_stall_ring))
                           break;
           }
   
           return (rt);
   }
   
   static __inline struct mfc *
   mfc_alloc(void)
   {
           struct mfc *rt;
           rt = (struct mfc*) malloc(sizeof(*rt), M_MRTABLE, M_NOWAIT | M_ZERO);
           if (rt == NULL)
                   return rt;
   
           rt->mfc_stall_ring = buf_ring_alloc(MAX_UPQ, M_MRTABLE,
               M_NOWAIT, &V_buf_ring_mtx);
           if (rt->mfc_stall_ring == NULL) {
                   free(rt, M_MRTABLE);
                   return NULL;
           }
   
           return rt;
   }
   
   /*
    * Handle MRT setsockopt commands to modify the multicast forwarding tables.
    */
   static int
   X_ip_mrouter_set(struct socket *so, struct sockopt *sopt)
   {
       int error, optval;
       vifi_t      vifi;
       struct      vifctl vifc;
       struct      mfcctl2 mfc;
       struct      bw_upcall bw_upcall;
       uint32_t    i;
   
       if (so != V_ip_mrouter && sopt->sopt_name != MRT_INIT)
           return EPERM;
   
       error = 0;
       switch (sopt->sopt_name) {
       case MRT_INIT:
           error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval);
           if (error)
               break;
           error = ip_mrouter_init(so, optval);
           break;
   
       case MRT_DONE:
           error = ip_mrouter_done();
           break;
   
       case MRT_ADD_VIF:
           error = sooptcopyin(sopt, &vifc, sizeof vifc, sizeof vifc);
           if (error)
               break;
           error = add_vif(&vifc);
           break;
   
       case MRT_DEL_VIF:
           error = sooptcopyin(sopt, &vifi, sizeof vifi, sizeof vifi);
           if (error)
               break;
           error = del_vif(vifi);
           break;
   
       case MRT_ADD_MFC:
       case MRT_DEL_MFC:
           /*
            * select data size depending on API version.
            */
           if (sopt->sopt_name == MRT_ADD_MFC &&
                   V_mrt_api_config & MRT_API_FLAGS_ALL) {
               error = sooptcopyin(sopt, &mfc, sizeof(struct mfcctl2),
                                   sizeof(struct mfcctl2));
           } else {
               error = sooptcopyin(sopt, &mfc, sizeof(struct mfcctl),
                                   sizeof(struct mfcctl));
               bzero((caddr_t)&mfc + sizeof(struct mfcctl),
                           sizeof(mfc) - sizeof(struct mfcctl));
           }
           if (error)
               break;
           if (sopt->sopt_name == MRT_ADD_MFC)
               error = add_mfc(&mfc);
           else
               error = del_mfc(&mfc);
           break;
   
       case MRT_ASSERT:
           error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval);
           if (error)
               break;
           set_assert(optval);
           break;
   
       case MRT_API_CONFIG:
           error = sooptcopyin(sopt, &i, sizeof i, sizeof i);
           if (!error)
               error = set_api_config(&i);
           if (!error)
               error = sooptcopyout(sopt, &i, sizeof i);
           break;
   
       case MRT_ADD_BW_UPCALL:
       case MRT_DEL_BW_UPCALL:
           error = sooptcopyin(sopt, &bw_upcall, sizeof bw_upcall,
                                   sizeof bw_upcall);
           if (error)
               break;
           if (sopt->sopt_name == MRT_ADD_BW_UPCALL)
               error = add_bw_upcall(&bw_upcall);
           else
               error = del_bw_upcall(&bw_upcall);
           break;
   
       default:
           error = EOPNOTSUPP;
           break;
       }
       return error;
   }
   
   /*
    * Handle MRT getsockopt commands
    */
   static int
   X_ip_mrouter_get(struct socket *so, struct sockopt *sopt)
   {
       int error;
   
       switch (sopt->sopt_name) {
       case MRT_VERSION:
           error = sooptcopyout(sopt, &mrt_api_version, sizeof mrt_api_version);
           break;
   
       case MRT_ASSERT:
           error = sooptcopyout(sopt, &V_pim_assert_enabled,
               sizeof V_pim_assert_enabled);
           break;
   
       case MRT_API_SUPPORT:
           error = sooptcopyout(sopt, &mrt_api_support, sizeof mrt_api_support);
           break;
   
       case MRT_API_CONFIG:
           error = sooptcopyout(sopt, &V_mrt_api_config, sizeof V_mrt_api_config);
           break;
   
       default:
           error = EOPNOTSUPP;
           break;
       }
       return error;
   }
   
   /*
    * Handle ioctl commands to obtain information from the cache
    */
   static int
   X_mrt_ioctl(u_long cmd, caddr_t data, int fibnum __unused)
   {
       int error = 0;
   
       /*
        * Currently the only function calling this ioctl routine is rtioctl_fib().
        * Typically, only root can create the raw socket in order to execute
        * this ioctl method, however the request might be coming from a prison
        */
       error = priv_check(curthread, PRIV_NETINET_MROUTE);
       if (error)
           return (error);
       switch (cmd) {
       case (SIOCGETVIFCNT):
           error = get_vif_cnt((struct sioc_vif_req *)data);
           break;
   
       case (SIOCGETSGCNT):
           error = get_sg_cnt((struct sioc_sg_req *)data);
           break;
   
       default:
           error = EINVAL;
           break;
       }
       return error;
   }
   
   /*
    * returns the packet, byte, rpf-failure count for the source group provided
    */
   static int
   get_sg_cnt(struct sioc_sg_req *req)
   {
       struct mfc *rt;
   
       MRW_RLOCK();
       rt = mfc_find(&req->src, &req->grp);
       if (rt == NULL) {
               MRW_RUNLOCK();
           req->pktcnt = req->bytecnt = req->wrong_if = 0xffffffff;
           return EADDRNOTAVAIL;
       }
       req->pktcnt = rt->mfc_pkt_cnt;
       req->bytecnt = rt->mfc_byte_cnt;
       req->wrong_if = rt->mfc_wrong_if;
       MRW_RUNLOCK();
       return 0;
   }
   
   /*
    * returns the input and output packet and byte counts on the vif provided
    */
   static int
   get_vif_cnt(struct sioc_vif_req *req)
   {
       vifi_t vifi = req->vifi;
   
       MRW_RLOCK();
       if (vifi >= V_numvifs) {
           MRW_RUNLOCK();
           return EINVAL;
       }
   
       mtx_lock_spin(&V_viftable[vifi].v_spin);
       req->icount = V_viftable[vifi].v_pkt_in;
       req->ocount = V_viftable[vifi].v_pkt_out;
       req->ibytes = V_viftable[vifi].v_bytes_in;
       req->obytes = V_viftable[vifi].v_bytes_out;
       mtx_unlock_spin(&V_viftable[vifi].v_spin);
       MRW_RUNLOCK();
   
       return 0;
   }
   
   static void
   if_detached_event(void *arg __unused, struct ifnet *ifp)
   {
       vifi_t vifi;
       u_long i, vifi_cnt = 0;
       struct ifnet *free_ptr;
   
       MRW_WLOCK();
   
       if (V_ip_mrouter == NULL) {
           MRW_WUNLOCK();
           return;
       }
   
       /*
        * Tear down multicast forwarder state associated with this ifnet.
        * 1. Walk the vif list, matching vifs against this ifnet.
        * 2. Walk the multicast forwarding cache (mfc) looking for
        *    inner matches with this vif's index.
        * 3. Expire any matching multicast forwarding cache entries.
        * 4. Free vif state. This should disable ALLMULTI on the interface.
        */
       for (vifi = 0; vifi < V_numvifs; vifi++) {
           if (V_viftable[vifi].v_ifp != ifp)
                   continue;
           for (i = 0; i < mfchashsize; i++) {
                   struct mfc *rt, *nrt;
   
                   LIST_FOREACH_SAFE(rt, &V_mfchashtbl[i], mfc_hash, nrt) {
                           if (rt->mfc_parent == vifi) {
                                   expire_mfc(rt);
                           }
                   }
           }
           del_vif_locked(vifi, &free_ptr);
           if (free_ptr != NULL)
                   vifi_cnt++;
       }
   
       MRW_WUNLOCK();
   
       /*
        * Free IFP. We don't have to use free_ptr here as it is the same
        * that ifp. Perform free as many times as required in case
        * refcount is greater than 1.
        */
       for (i = 0; i < vifi_cnt; i++)
               if_free(ifp);
   }
   
   static void
   ip_mrouter_upcall_thread(void *arg, int pending __unused)
   {
           CURVNET_SET((struct vnet *) arg);
   
           MRW_WLOCK();
           bw_upcalls_send();
           MRW_WUNLOCK();
   
           CURVNET_RESTORE();
   }
   
   /*
    * Enable multicast forwarding.
    */
   static int
   ip_mrouter_init(struct socket *so, int version)
   {
   
       CTR2(KTR_IPMF, "%s: so %p", __func__, so);
   
       if (version != 1)
           return ENOPROTOOPT;
   
       MRW_WLOCK();
   
       if (ip_mrouter_unloading) {
           MRW_WUNLOCK();
           return ENOPROTOOPT;
       }
   
       if (V_ip_mrouter != NULL) {
           MRW_WUNLOCK();
           return EADDRINUSE;
       }
   
       V_mfchashtbl = hashinit_flags(mfchashsize, M_MRTABLE, &V_mfchash,
           HASH_NOWAIT);
   
       /* Create upcall ring */
       mtx_init(&V_bw_upcalls_ring_mtx, "mroute upcall buf_ring mtx", NULL, MTX_DEF);
       V_bw_upcalls_ring = buf_ring_alloc(BW_UPCALLS_MAX, M_MRTABLE,
           M_NOWAIT, &V_bw_upcalls_ring_mtx);
       if (!V_bw_upcalls_ring) {
           MRW_WUNLOCK();
           return (ENOMEM);
       }
   
       TASK_INIT(&V_task, 0, ip_mrouter_upcall_thread, curvnet);
       taskqueue_cancel(V_task_queue, &V_task, NULL);
       taskqueue_unblock(V_task_queue);
   
       callout_reset(&V_expire_upcalls_ch, EXPIRE_TIMEOUT, expire_upcalls,
           curvnet);
       callout_reset(&V_bw_upcalls_ch, BW_UPCALLS_PERIOD, expire_bw_upcalls_send,
           curvnet);
   
       V_ip_mrouter = so;
       atomic_add_int(&ip_mrouter_cnt, 1);
   
       /* This is a mutex required by buf_ring init, but not used internally */
       mtx_init(&V_buf_ring_mtx, "mroute buf_ring mtx", NULL, MTX_DEF);
   
       MRW_WUNLOCK();
   
       CTR1(KTR_IPMF, "%s: done", __func__);
   
       return 0;
   }
   
   /*
    * Disable multicast forwarding.
    */
   static int
   X_ip_mrouter_done(void)
   {
       struct ifnet **ifps;
       int nifp;
       u_long i;
       vifi_t vifi;
       struct bw_upcall *bu;
   
       if (V_ip_mrouter == NULL)
           return (EINVAL);
   
       /*
        * Detach/disable hooks to the reset of the system.
        */
       V_ip_mrouter = NULL;
       atomic_subtract_int(&ip_mrouter_cnt, 1);
       V_mrt_api_config = 0;
   
       /*
        * Wait for all epoch sections to complete to ensure
        * V_ip_mrouter = NULL is visible to others.
        */
       epoch_wait_preempt(net_epoch_preempt);
   
       /* Stop and drain task queue */
       taskqueue_block(V_task_queue);
       while (taskqueue_cancel(V_task_queue, &V_task, NULL)) {
           taskqueue_drain(V_task_queue, &V_task);
       }
   
       ifps = malloc(MAXVIFS * sizeof(*ifps), M_TEMP, M_WAITOK);
   
       MRW_WLOCK();
       taskqueue_cancel(V_task_queue, &V_task, NULL);
   
       /* Destroy upcall ring */
       while ((bu = buf_ring_dequeue_mc(V_bw_upcalls_ring)) != NULL) {
           free(bu, M_MRTABLE);
       }
       buf_ring_free(V_bw_upcalls_ring, M_MRTABLE);
       mtx_destroy(&V_bw_upcalls_ring_mtx);
   
       /*
        * For each phyint in use, prepare to disable promiscuous reception
        * of all IP multicasts.  Defer the actual call until the lock is released;
        * just record the list of interfaces while locked.  Some interfaces use
        * sx locks in their ioctl routines, which is not allowed while holding
        * a non-sleepable lock.
        */
       KASSERT(V_numvifs <= MAXVIFS, ("More vifs than possible"));
       for (vifi = 0, nifp = 0; vifi < V_numvifs; vifi++) {
           if (!in_nullhost(V_viftable[vifi].v_lcl_addr) &&
                   !(V_viftable[vifi].v_flags & (VIFF_TUNNEL | VIFF_REGISTER))) {
               ifps[nifp++] = V_viftable[vifi].v_ifp;
           }
       }
       bzero((caddr_t)V_viftable, sizeof(*V_viftable) * MAXVIFS);
       V_numvifs = 0;
       V_pim_assert_enabled = 0;
   
       callout_stop(&V_expire_upcalls_ch);
       callout_stop(&V_bw_upcalls_ch);
   
       /*
        * Free all multicast forwarding cache entries.
        * Do not use hashdestroy(), as we must perform other cleanup.
        */
       for (i = 0; i < mfchashsize; i++) {
           struct mfc *rt, *nrt;
   
           LIST_FOREACH_SAFE(rt, &V_mfchashtbl[i], mfc_hash, nrt) {
                   expire_mfc(rt);
           }
       }
       free(V_mfchashtbl, M_MRTABLE);
       V_mfchashtbl = NULL;
   
       bzero(V_nexpire, sizeof(V_nexpire[0]) * mfchashsize);
   
       V_reg_vif_num = VIFI_INVALID;
   
       mtx_destroy(&V_buf_ring_mtx);
   
       MRW_WUNLOCK();
   
       /*
        * Now drop our claim on promiscuous multicast on the interfaces recorded
        * above.  This is safe to do now because ALLMULTI is reference counted.
        */
       for (vifi = 0; vifi < nifp; vifi++)
               if_allmulti(ifps[vifi], 0);
       free(ifps, M_TEMP);
   
       CTR1(KTR_IPMF, "%s: done", __func__);
   
       return 0;
   }
   
   /*
    * Set PIM assert processing global
    */
   static int
   set_assert(int i)
   {
       if ((i != 1) && (i != 0))
           return EINVAL;
   
       V_pim_assert_enabled = i;
   
       return 0;
   }
   
   /*
    * Configure API capabilities
    */
   int
   set_api_config(uint32_t *apival)
   {
       u_long i;
   
       /*
        * We can set the API capabilities only if it is the first operation
        * after MRT_INIT. I.e.:
        *  - there are no vifs installed
        *  - pim_assert is not enabled
        *  - the MFC table is empty
        */
       if (V_numvifs > 0) {
           *apival = 0;
           return EPERM;
       }
       if (V_pim_assert_enabled) {
           *apival = 0;
           return EPERM;
       }
   
       MRW_RLOCK();
   
       for (i = 0; i < mfchashsize; i++) {
           if (LIST_FIRST(&V_mfchashtbl[i]) != NULL) {
               MRW_RUNLOCK();
               *apival = 0;
               return EPERM;
           }
       }
   
       MRW_RUNLOCK();
   
       V_mrt_api_config = *apival & mrt_api_support;
       *apival = V_mrt_api_config;
   
       return 0;
   }
   
   /*
    * Add a vif to the vif table
    */
   static int
   add_vif(struct vifctl *vifcp)
   {
       struct vif *vifp = V_viftable + vifcp->vifc_vifi;
       struct sockaddr_in sin = {sizeof sin, AF_INET};
       struct ifaddr *ifa;
       struct ifnet *ifp;
       int error;
   
   
       if (vifcp->vifc_vifi >= MAXVIFS)
           return EINVAL;
       /* rate limiting is no longer supported by this code */
       if (vifcp->vifc_rate_limit != 0) {
           log(LOG_ERR, "rate limiting is no longer supported\n");
           return EINVAL;
       }
   
       if (in_nullhost(vifcp->vifc_lcl_addr))
           return EADDRNOTAVAIL;
   
       /* Find the interface with an address in AF_INET family */
       if (vifcp->vifc_flags & VIFF_REGISTER) {
           /*
            * XXX: Because VIFF_REGISTER does not really need a valid
            * local interface (e.g. it could be 127.0.0.2), we don't
            * check its address.
            */
           ifp = NULL;
       } else {
           struct epoch_tracker et;
   
           sin.sin_addr = vifcp->vifc_lcl_addr;
           NET_EPOCH_ENTER(et);
           ifa = ifa_ifwithaddr((struct sockaddr *)&sin);
           if (ifa == NULL) {
               NET_EPOCH_EXIT(et);
               return EADDRNOTAVAIL;
           }
           ifp = ifa->ifa_ifp;
           /* XXX FIXME we need to take a ref on ifp and cleanup properly! */
           NET_EPOCH_EXIT(et);
       }
   
       if ((vifcp->vifc_flags & VIFF_TUNNEL) != 0) {
           CTR1(KTR_IPMF, "%s: tunnels are no longer supported", __func__);
           return EOPNOTSUPP;
       } else if (vifcp->vifc_flags & VIFF_REGISTER) {
           ifp = V_multicast_register_if = if_alloc(IFT_LOOP);
           CTR2(KTR_IPMF, "%s: add register vif for ifp %p", __func__, ifp);
           if (V_reg_vif_num == VIFI_INVALID) {
               if_initname(V_multicast_register_if, "register_vif", 0);
               V_reg_vif_num = vifcp->vifc_vifi;
           }
       } else {            /* Make sure the interface supports multicast */
           if ((ifp->if_flags & IFF_MULTICAST) == 0)
               return EOPNOTSUPP;
   
           /* Enable promiscuous reception of all IP multicasts from the if */
           error = if_allmulti(ifp, 1);
           if (error)
               return error;
       }
   
       MRW_WLOCK();
   
       if (!in_nullhost(vifp->v_lcl_addr)) {
           if (ifp)
                   V_multicast_register_if = NULL;
           MRW_WUNLOCK();
           if (ifp)
                   if_free(ifp);
           return EADDRINUSE;
       }
   
       vifp->v_flags     = vifcp->vifc_flags;
       vifp->v_threshold = vifcp->vifc_threshold;
       vifp->v_lcl_addr  = vifcp->vifc_lcl_addr;
       vifp->v_rmt_addr  = vifcp->vifc_rmt_addr;
       vifp->v_ifp       = ifp;
       /* initialize per vif pkt counters */
       vifp->v_pkt_in    = 0;
       vifp->v_pkt_out   = 0;
       vifp->v_bytes_in  = 0;
       vifp->v_bytes_out = 0;
       sprintf(vifp->v_spin_name, "BM[%d] spin", vifcp->vifc_vifi);
       mtx_init(&vifp->v_spin, vifp->v_spin_name, NULL, MTX_SPIN);
   
       /* Adjust numvifs up if the vifi is higher than numvifs */
       if (V_numvifs <= vifcp->vifc_vifi)
           V_numvifs = vifcp->vifc_vifi + 1;
   
       MRW_WUNLOCK();
   
       CTR4(KTR_IPMF, "%s: add vif %d laddr 0x%08x thresh %x", __func__,
           (int)vifcp->vifc_vifi, ntohl(vifcp->vifc_lcl_addr.s_addr),
           (int)vifcp->vifc_threshold);
   
       return 0;
  }
  
  /*
   * Delete a vif from the vif table
   */
  static int
  del_vif_locked(vifi_t vifi, struct ifnet **ifp_free)
  {
      struct vif *vifp;
  
      *ifp_free = NULL;
  
      MRW_WLOCK_ASSERT();
  
      if (vifi >= V_numvifs) {
          return EINVAL;
      }
      vifp = &V_viftable[vifi];
      if (in_nullhost(vifp->v_lcl_addr)) {
          return EADDRNOTAVAIL;
      }
  
      if (!(vifp->v_flags & (VIFF_TUNNEL | VIFF_REGISTER)))
          if_allmulti(vifp->v_ifp, 0);
  
      if (vifp->v_flags & VIFF_REGISTER) {
          V_reg_vif_num = VIFI_INVALID;
          if (vifp->v_ifp) {
              if (vifp->v_ifp == V_multicast_register_if)
                  V_multicast_register_if = NULL;
              *ifp_free = vifp->v_ifp;
          }
      }
  
      mtx_destroy(&vifp->v_spin);
  
      bzero((caddr_t)vifp, sizeof (*vifp));
  
      CTR2(KTR_IPMF, "%s: delete vif %d", __func__, (int)vifi);
  
      /* Adjust numvifs down */
      for (vifi = V_numvifs; vifi > 0; vifi--)
          if (!in_nullhost(V_viftable[vifi-1].v_lcl_addr))
              break;
      V_numvifs = vifi;
  
      return 0;
  }
  
  static int
  del_vif(vifi_t vifi)
  {
      int cc;
      struct ifnet *free_ptr;
  
      MRW_WLOCK();
      cc = del_vif_locked(vifi, &free_ptr);
      MRW_WUNLOCK();
  
      if (free_ptr)
              if_free(free_ptr);
  
      return cc;
  }
  
  /*
   * update an mfc entry without resetting counters and S,G addresses.
   */
  static void
  update_mfc_params(struct mfc *rt, struct mfcctl2 *mfccp)
  {
      int i;
  
      rt->mfc_parent = mfccp->mfcc_parent;
      for (i = 0; i < V_numvifs; i++) {
          rt->mfc_ttls[i] = mfccp->mfcc_ttls[i];
          rt->mfc_flags[i] = mfccp->mfcc_flags[i] & V_mrt_api_config &
              MRT_MFC_FLAGS_ALL;
      }
      /* set the RP address */
      if (V_mrt_api_config & MRT_MFC_RP)
          rt->mfc_rp = mfccp->mfcc_rp;
      else
          rt->mfc_rp.s_addr = INADDR_ANY;
  }
  
  /*
   * fully initialize an mfc entry from the parameter.
   */
  static void
  init_mfc_params(struct mfc *rt, struct mfcctl2 *mfccp)
  {
      rt->mfc_origin     = mfccp->mfcc_origin;
      rt->mfc_mcastgrp   = mfccp->mfcc_mcastgrp;
  
      update_mfc_params(rt, mfccp);
  
      /* initialize pkt counters per src-grp */
      rt->mfc_pkt_cnt    = 0;
      rt->mfc_byte_cnt   = 0;
      rt->mfc_wrong_if   = 0;
      timevalclear(&rt->mfc_last_assert);
  }
  
  static void
  expire_mfc(struct mfc *rt)
  {
          struct rtdetq *rte;
  
          MRW_WLOCK_ASSERT();
  
          free_bw_list(rt->mfc_bw_meter_leq);
          free_bw_list(rt->mfc_bw_meter_geq);
  
          while (!buf_ring_empty(rt->mfc_stall_ring)) {
                  rte = buf_ring_dequeue_mc(rt->mfc_stall_ring);
                  if (rte) {
                          m_freem(rte->m);
                          free(rte, M_MRTABLE);
                  }
          }
          buf_ring_free(rt->mfc_stall_ring, M_MRTABLE);
  
          LIST_REMOVE(rt, mfc_hash);
          free(rt, M_MRTABLE);
  }
  
  /*
   * Add an mfc entry
   */
  static int
  add_mfc(struct mfcctl2 *mfccp)
  {
      struct mfc *rt;
      struct rtdetq *rte;
      u_long hash = 0;
      u_short nstl;
      struct epoch_tracker et;
  
      MRW_WLOCK();
      rt = mfc_find(&mfccp->mfcc_origin, &mfccp->mfcc_mcastgrp);
  
      /* If an entry already exists, just update the fields */
      if (rt) {
          CTR4(KTR_IPMF, "%s: update mfc orig 0x%08x group %lx parent %x",
              __func__, ntohl(mfccp->mfcc_origin.s_addr),
              (u_long)ntohl(mfccp->mfcc_mcastgrp.s_addr),
              mfccp->mfcc_parent);
          update_mfc_params(rt, mfccp);
          MRW_WUNLOCK();
          return (0);
      }
  
      /*
       * Find the entry for which the upcall was made and update
       */
      nstl = 0;
      hash = MFCHASH(mfccp->mfcc_origin, mfccp->mfcc_mcastgrp);
      NET_EPOCH_ENTER(et);
      LIST_FOREACH(rt, &V_mfchashtbl[hash], mfc_hash) {
          if (in_hosteq(rt->mfc_origin, mfccp->mfcc_origin) &&
              in_hosteq(rt->mfc_mcastgrp, mfccp->mfcc_mcastgrp) &&
              !buf_ring_empty(rt->mfc_stall_ring)) {
                  CTR5(KTR_IPMF,
                      "%s: add mfc orig 0x%08x group %lx parent %x qh %p",
                      __func__, ntohl(mfccp->mfcc_origin.s_addr),
                      (u_long)ntohl(mfccp->mfcc_mcastgrp.s_addr),
                      mfccp->mfcc_parent,
                      rt->mfc_stall_ring);
                  if (nstl++)
                          CTR1(KTR_IPMF, "%s: multiple matches", __func__);
  
                  init_mfc_params(rt, mfccp);
                  rt->mfc_expire = 0;     /* Don't clean this guy up */
                  V_nexpire[hash]--;
  
                  /* Free queued packets, but attempt to forward them first. */
                  while (!buf_ring_empty(rt->mfc_stall_ring)) {
                          rte = buf_ring_dequeue_mc(rt->mfc_stall_ring);
                          if (rte->ifp != NULL)
                                  ip_mdq(rte->m, rte->ifp, rt, -1);
                          m_freem(rte->m);
                          free(rte, M_MRTABLE);
                  }
          }
      }
      NET_EPOCH_EXIT(et);
  
      /*
       * It is possible that an entry is being inserted without an upcall
       */
      if (nstl == 0) {
          CTR1(KTR_IPMF, "%s: adding mfc w/o upcall", __func__);
          LIST_FOREACH(rt, &V_mfchashtbl[hash], mfc_hash) {
                  if (in_hosteq(rt->mfc_origin, mfccp->mfcc_origin) &&
                      in_hosteq(rt->mfc_mcastgrp, mfccp->mfcc_mcastgrp)) {
                          init_mfc_params(rt, mfccp);
                          if (rt->mfc_expire)
                              V_nexpire[hash]--;
                          rt->mfc_expire = 0;
                          break; /* XXX */
                  }
          }
  
          if (rt == NULL) {               /* no upcall, so make a new entry */
              rt = mfc_alloc();
              if (rt == NULL) {
                  MRW_WUNLOCK();
                  return (ENOBUFS);
              }
  
              init_mfc_params(rt, mfccp);
  
              rt->mfc_expire     = 0;
              rt->mfc_bw_meter_leq = NULL;
              rt->mfc_bw_meter_geq = NULL;
  
              /* insert new entry at head of hash chain */
              LIST_INSERT_HEAD(&V_mfchashtbl[hash], rt, mfc_hash);
          }
      }
  
      MRW_WUNLOCK();
  
      return (0);
  }
  
  /*
   * Delete an mfc entry
   */
  static int
  del_mfc(struct mfcctl2 *mfccp)
  {
      struct in_addr      origin;
      struct in_addr      mcastgrp;
      struct mfc          *rt;
  
      origin = mfccp->mfcc_origin;
      mcastgrp = mfccp->mfcc_mcastgrp;
  
      CTR3(KTR_IPMF, "%s: delete mfc orig 0x%08x group %lx", __func__,
          ntohl(origin.s_addr), (u_long)ntohl(mcastgrp.s_addr));
  
      MRW_WLOCK();
  
      rt = mfc_find(&origin, &mcastgrp);
      if (rt == NULL) {
          MRW_WUNLOCK();
          return EADDRNOTAVAIL;
      }
  
      /*
       * free the bw_meter entries
       */
      free_bw_list(rt->mfc_bw_meter_leq);
      rt->mfc_bw_meter_leq = NULL;
      free_bw_list(rt->mfc_bw_meter_geq);
      rt->mfc_bw_meter_geq = NULL;
  
      LIST_REMOVE(rt, mfc_hash);
      free(rt, M_MRTABLE);
  
      MRW_WUNLOCK();
  
      return (0);
  }
  
  /*
   * Send a message to the routing daemon on the multicast routing socket.
   */
  static int
  socket_send(struct socket *s, struct mbuf *mm, struct sockaddr_in *src)
  {
      if (s) {
          SOCKBUF_LOCK(&s->so_rcv);
          if (sbappendaddr_locked(&s->so_rcv, (struct sockaddr *)src, mm,
              NULL) != 0) {
              sorwakeup_locked(s);
              return 0;
          }
          soroverflow_locked(s);
      }
      m_freem(mm);
      return -1;
  }
  
  /*
   * IP multicast forwarding function. This function assumes that the packet
   * pointed to by "ip" has arrived on (or is about to be sent to) the interface
   * pointed to by "ifp", and the packet is to be relayed to other networks
   * that have members of the packet's destination IP multicast group.
   *
   * The packet is returned unscathed to the caller, unless it is
   * erroneous, in which case a non-zero return value tells the caller to
   * discard it.
   */
  
  #define TUNNEL_LEN  12  /* # bytes of IP option for tunnel encapsulation  */
  
  static int
  X_ip_mforward(struct ip *ip, struct ifnet *ifp, struct mbuf *m,
      struct ip_moptions *imo)
  {
          struct mfc *rt;
          int error;
          vifi_t vifi;
          struct mbuf *mb0;
          struct rtdetq *rte;
          u_long hash;
          int hlen;
  
          CTR3(KTR_IPMF, "ip_mforward: delete mfc orig 0x%08x group %lx ifp %p",
              ntohl(ip->ip_src.s_addr), (u_long)ntohl(ip->ip_dst.s_addr), ifp);
  
          if (ip->ip_hl < (sizeof(struct ip) + TUNNEL_LEN) >> 2 ||
              ((u_char *)(ip + 1))[1] != IPOPT_LSRR) {
                  /*
                   * Packet arrived via a physical interface or
                   * an encapsulated tunnel or a register_vif.
                   */
          } else {
                  /*
                   * Packet arrived through a source-route tunnel.
                   * Source-route tunnels are no longer supported.
                   */
                  return (1);
          }
  
          /*
           * BEGIN: MCAST ROUTING HOT PATH
           */
          MRW_RLOCK();
          if (imo && ((vifi = imo->imo_multicast_vif) < V_numvifs)) {
                  if (ip->ip_ttl < MAXTTL)
                          ip->ip_ttl++; /* compensate for -1 in *_send routines */
                  error = ip_mdq(m, ifp, NULL, vifi);
                  MRW_RUNLOCK();
                  return error;
          }
  
          /*
           * Don't forward a packet with time-to-live of zero or one,
           * or a packet destined to a local-only group.
           */
          if (ip->ip_ttl <= 1 || IN_LOCAL_GROUP(ntohl(ip->ip_dst.s_addr))) {
                  MRW_RUNLOCK();
                  return 0;
          }
  
          mfc_find_retry:
          /*
           * Determine forwarding vifs from the forwarding cache table
           */
          MRTSTAT_INC(mrts_mfc_lookups);
          rt = mfc_find(&ip->ip_src, &ip->ip_dst);
  
          /* Entry exists, so forward if necessary */
          if (rt != NULL) {
                  error = ip_mdq(m, ifp, rt, -1);
                  /* Generic unlock here as we might release R or W lock */
                  MRW_UNLOCK();
                  return error;
          }
  
          /*
           * END: MCAST ROUTING HOT PATH
           */
  
          /* Further processing must be done with WLOCK taken */
          if ((MRW_WOWNED() == 0) && (MRW_LOCK_TRY_UPGRADE() == 0)) {
                  MRW_RUNLOCK();
                  MRW_WLOCK();
                  goto mfc_find_retry;
          }
  
          /*
           * If we don't have a route for packet's origin,
           * Make a copy of the packet & send message to routing daemon
           */
          hlen = ip->ip_hl << 2;
  
          MRTSTAT_INC(mrts_mfc_misses);
          MRTSTAT_INC(mrts_no_route);
          CTR2(KTR_IPMF, "ip_mforward: no mfc for (0x%08x,%lx)",
              ntohl(ip->ip_src.s_addr), (u_long)ntohl(ip->ip_dst.s_addr));
  
          /*
           * Allocate mbufs early so that we don't do extra work if we are
           * just going to fail anyway.  Make sure to pullup the header so
           * that other people can't step on it.
           */
          rte = (struct rtdetq*) malloc((sizeof *rte), M_MRTABLE,
              M_NOWAIT|M_ZERO);
          if (rte == NULL) {
                  MRW_WUNLOCK();
                  return ENOBUFS;
          }
  
          mb0 = m_copypacket(m, M_NOWAIT);
          if (mb0 && (!M_WRITABLE(mb0) || mb0->m_len < hlen))
                  mb0 = m_pullup(mb0, hlen);
          if (mb0 == NULL) {
                  free(rte, M_MRTABLE);
                  MRW_WUNLOCK();
                  return ENOBUFS;
          }
  
          /* is there an upcall waiting for this flow ? */
          hash = MFCHASH(ip->ip_src, ip->ip_dst);
          LIST_FOREACH(rt, &V_mfchashtbl[hash], mfc_hash)
          {
                  if (in_hosteq(ip->ip_src, rt->mfc_origin) &&
                      in_hosteq(ip->ip_dst, rt->mfc_mcastgrp) &&
                      !buf_ring_empty(rt->mfc_stall_ring))
                          break;
          }
  
          if (rt == NULL) {
                  int i;
                  struct igmpmsg *im;
                  struct sockaddr_in k_igmpsrc = { sizeof k_igmpsrc, AF_INET };
                  struct mbuf *mm;
  
                  /*
                   * Locate the vifi for the incoming interface for this packet.
                   * If none found, drop packet.
                   */
                  for (vifi = 0; vifi < V_numvifs &&
                      V_viftable[vifi].v_ifp != ifp; vifi++)
                          ;
                  if (vifi >= V_numvifs) /* vif not found, drop packet */
                          goto non_fatal;
  
                  /* no upcall, so make a new entry */
                  rt = mfc_alloc();
                  if (rt == NULL)
                          goto fail;
  
                  /* Make a copy of the header to send to the user level process */
                  mm = m_copym(mb0, 0, hlen, M_NOWAIT);
                  if (mm == NULL)
                          goto fail1;
  
                  /*
                   * Send message to routing daemon to install
                   * a route into the kernel table
                   */
  
                  im = mtod(mm, struct igmpmsg*);
                  im->im_msgtype = IGMPMSG_NOCACHE;
                  im->im_mbz = 0;
                  im->im_vif = vifi;
  
                  MRTSTAT_INC(mrts_upcalls);
  
                  k_igmpsrc.sin_addr = ip->ip_src;
                  if (socket_send(V_ip_mrouter, mm, &k_igmpsrc) < 0) {
                          CTR0(KTR_IPMF, "ip_mforward: socket queue full");
                          MRTSTAT_INC(mrts_upq_sockfull);
                          fail1: free(rt, M_MRTABLE);
                          fail: free(rte, M_MRTABLE);
                          m_freem(mb0);
                          MRW_WUNLOCK();
                          return ENOBUFS;
                  }
  
                  /* insert new entry at head of hash chain */
                  rt->mfc_origin.s_addr = ip->ip_src.s_addr;
                  rt->mfc_mcastgrp.s_addr = ip->ip_dst.s_addr;
                  rt->mfc_expire = UPCALL_EXPIRE;
                  V_nexpire[hash]++;
                  for (i = 0; i < V_numvifs; i++) {
                          rt->mfc_ttls[i] = 0;
                          rt->mfc_flags[i] = 0;
                  }
                  rt->mfc_parent = -1;
  
                  /* clear the RP address */
                  rt->mfc_rp.s_addr = INADDR_ANY;
                  rt->mfc_bw_meter_leq = NULL;
                  rt->mfc_bw_meter_geq = NULL;
  
                  /* initialize pkt counters per src-grp */
                  rt->mfc_pkt_cnt = 0;
                  rt->mfc_byte_cnt = 0;
                  rt->mfc_wrong_if = 0;
                  timevalclear(&rt->mfc_last_assert);
  
                  buf_ring_enqueue(rt->mfc_stall_ring, rte);
  
                  /* Add RT to hashtable as it didn't exist before */
                  LIST_INSERT_HEAD(&V_mfchashtbl[hash], rt, mfc_hash);
          } else {
                  /* determine if queue has overflowed */
                  if (buf_ring_full(rt->mfc_stall_ring)) {
                          MRTSTAT_INC(mrts_upq_ovflw);
                          non_fatal: free(rte, M_MRTABLE);
                          m_freem(mb0);
                          MRW_WUNLOCK();
                          return (0);
                  }
  
                  buf_ring_enqueue(rt->mfc_stall_ring, rte);
          }
  
          rte->m = mb0;
          rte->ifp = ifp;
  
          MRW_WUNLOCK();
  
          return 0;
  }
  
  /*
   * Clean up the cache entry if upcall is not serviced
   */
  static void
  expire_upcalls(void *arg)
  {
      u_long i;
  
      CURVNET_SET((struct vnet *) arg);
  
      /*This callout is always run with MRW_WLOCK taken. */
  
      for (i = 0; i < mfchashsize; i++) {
          struct mfc *rt, *nrt;
  
          if (V_nexpire[i] == 0)
              continue;
  
          LIST_FOREACH_SAFE(rt, &V_mfchashtbl[i], mfc_hash, nrt) {
                  if (buf_ring_empty(rt->mfc_stall_ring))
                          continue;
  
                  if (rt->mfc_expire == 0 || --rt->mfc_expire > 0)
                          continue;
  
                  MRTSTAT_INC(mrts_cache_cleanups);
                  CTR3(KTR_IPMF, "%s: expire (%lx, %lx)", __func__,
                      (u_long)ntohl(rt->mfc_origin.s_addr),
                      (u_long)ntohl(rt->mfc_mcastgrp.s_addr));
  
                  expire_mfc(rt);
              }
      }
  
      callout_reset(&V_expire_upcalls_ch, EXPIRE_TIMEOUT, expire_upcalls,
          curvnet);
  
      CURVNET_RESTORE();
  }
  
  /*
   * Packet forwarding routine once entry in the cache is made
   */
  static int
  ip_mdq(struct mbuf *m, struct ifnet *ifp, struct mfc *rt, vifi_t xmt_vif)
  {
      struct ip  *ip = mtod(m, struct ip *);
      vifi_t vifi;
      int plen = ntohs(ip->ip_len);
  
      MRW_LOCK_ASSERT();
      NET_EPOCH_ASSERT();
  
      /*
       * If xmt_vif is not -1, send on only the requested vif.
       *
       * (since vifi_t is u_short, -1 becomes MAXUSHORT, which > numvifs.)
       */
      if (xmt_vif < V_numvifs) {
          if (V_viftable[xmt_vif].v_flags & VIFF_REGISTER)
                  pim_register_send(ip, V_viftable + xmt_vif, m, rt);
          else
                  phyint_send(ip, V_viftable + xmt_vif, m);
          return 1;
      }
  
      /*
       * Don't forward if it didn't arrive from the parent vif for its origin.
       */
      vifi = rt->mfc_parent;
      if ((vifi >= V_numvifs) || (V_viftable[vifi].v_ifp != ifp)) {
          CTR4(KTR_IPMF, "%s: rx on wrong ifp %p (vifi %d, v_ifp %p)",
              __func__, ifp, (int)vifi, V_viftable[vifi].v_ifp);
          MRTSTAT_INC(mrts_wrong_if);
          ++rt->mfc_wrong_if;
          /*
           * If we are doing PIM assert processing, send a message
           * to the routing daemon.
           *
           * XXX: A PIM-SM router needs the WRONGVIF detection so it
           * can complete the SPT switch, regardless of the type
           * of the iif (broadcast media, GRE tunnel, etc).
           */
          if (V_pim_assert_enabled && (vifi < V_numvifs) &&
              V_viftable[vifi].v_ifp) {
              if (ifp == V_multicast_register_if)
                  PIMSTAT_INC(pims_rcv_registers_wrongiif);
  
              /* Get vifi for the incoming packet */
              for (vifi = 0; vifi < V_numvifs && V_viftable[vifi].v_ifp != ifp;
                  vifi++)
                  ;
              if (vifi >= V_numvifs)
                  return 0;       /* The iif is not found: ignore the packet. */
  
              if (rt->mfc_flags[vifi] & MRT_MFC_FLAGS_DISABLE_WRONGVIF)
                  return 0;       /* WRONGVIF disabled: ignore the packet */
  
              if (ratecheck(&rt->mfc_last_assert, &pim_assert_interval)) {
                  struct sockaddr_in k_igmpsrc = { sizeof k_igmpsrc, AF_INET };
                  struct igmpmsg *im;
                  int hlen = ip->ip_hl << 2;
                  struct mbuf *mm = m_copym(m, 0, hlen, M_NOWAIT);
  
                  if (mm && (!M_WRITABLE(mm) || mm->m_len < hlen))
                      mm = m_pullup(mm, hlen);
                  if (mm == NULL)
                      return ENOBUFS;
  
                  im = mtod(mm, struct igmpmsg *);
                  im->im_msgtype  = IGMPMSG_WRONGVIF;
                  im->im_mbz              = 0;
                  im->im_vif              = vifi;
  
                  MRTSTAT_INC(mrts_upcalls);
  
                  k_igmpsrc.sin_addr = im->im_src;
                  if (socket_send(V_ip_mrouter, mm, &k_igmpsrc) < 0) {
                      CTR1(KTR_IPMF, "%s: socket queue full", __func__);
                      MRTSTAT_INC(mrts_upq_sockfull);
                      return ENOBUFS;
                  }
              }
          }
          return 0;
      }
  
      /* If I sourced this packet, it counts as output, else it was input. */
      mtx_lock_spin(&V_viftable[vifi].v_spin);
      if (in_hosteq(ip->ip_src, V_viftable[vifi].v_lcl_addr)) {
          V_viftable[vifi].v_pkt_out++;
          V_viftable[vifi].v_bytes_out += plen;
      } else {
          V_viftable[vifi].v_pkt_in++;
          V_viftable[vifi].v_bytes_in += plen;
      }
      mtx_unlock_spin(&V_viftable[vifi].v_spin);
  
      rt->mfc_pkt_cnt++;
      rt->mfc_byte_cnt += plen;
  
      /*
       * For each vif, decide if a copy of the packet should be forwarded.
       * Forward if:
       *          - the ttl exceeds the vif's threshold
       *          - there are group members downstream on interface
       */
      for (vifi = 0; vifi < V_numvifs; vifi++)
          if ((rt->mfc_ttls[vifi] > 0) && (ip->ip_ttl > rt->mfc_ttls[vifi])) {
              V_viftable[vifi].v_pkt_out++;
              V_viftable[vifi].v_bytes_out += plen;
              if (V_viftable[vifi].v_flags & VIFF_REGISTER)
                  pim_register_send(ip, V_viftable + vifi, m, rt);
              else
                  phyint_send(ip, V_viftable + vifi, m);
          }
  
      /*
       * Perform upcall-related bw measuring.
       */
      if ((rt->mfc_bw_meter_geq != NULL) || (rt->mfc_bw_meter_leq != NULL)) {
          struct bw_meter *x;
          struct timeval now;
  
          microtime(&now);
          /* Process meters for Greater-or-EQual case */
          for (x = rt->mfc_bw_meter_geq; x != NULL; x = x->bm_mfc_next)
                  bw_meter_geq_receive_packet(x, plen, &now);
  
          /* Process meters for Lower-or-EQual case */
          for (x = rt->mfc_bw_meter_leq; x != NULL; x = x->bm_mfc_next) {
                  /*
                   * Record that a packet is received.
                   * Spin lock has to be taken as callout context
                   * (expire_bw_meter_leq) might modify these fields
                   * as well
                   */
                  mtx_lock_spin(&x->bm_spin);
                  x->bm_measured.b_packets++;
                  x->bm_measured.b_bytes += plen;
                  mtx_unlock_spin(&x->bm_spin);
          }
      }
  
      return 0;
  }
  
  /*
   * Check if a vif number is legal/ok. This is used by in_mcast.c.
   */
  static int
  X_legal_vif_num(int vif)
  {
          int ret;
  
          ret = 0;
          if (vif < 0)
                  return (ret);
  
          MRW_RLOCK();
          if (vif < V_numvifs)
                  ret = 1;
          MRW_RUNLOCK();
  
          return (ret);
  }
  
  /*
   * Return the local address used by this vif
   */
  static u_long
  X_ip_mcast_src(int vifi)
  {
          in_addr_t addr;
  
          addr = INADDR_ANY;
          if (vifi < 0)
                  return (addr);
  
          MRW_RLOCK();
          if (vifi < V_numvifs)
                  addr = V_viftable[vifi].v_lcl_addr.s_addr;
          MRW_RUNLOCK();
  
          return (addr);
  }
  
  static void
  phyint_send(struct ip *ip, struct vif *vifp, struct mbuf *m)
  {
      struct mbuf *mb_copy;
      int hlen = ip->ip_hl << 2;
  
      MRW_LOCK_ASSERT();
  
      /*
       * Make a new reference to the packet; make sure that
       * the IP header is actually copied, not just referenced,
       * so that ip_output() only scribbles on the copy.
       */
      mb_copy = m_copypacket(m, M_NOWAIT);
      if (mb_copy && (!M_WRITABLE(mb_copy) || mb_copy->m_len < hlen))
          mb_copy = m_pullup(mb_copy, hlen);
      if (mb_copy == NULL)
          return;
  
      send_packet(vifp, mb_copy);
  }
  
  static void
  send_packet(struct vif *vifp, struct mbuf *m)
  {
          struct ip_moptions imo;
          int error __unused;
  
          MRW_LOCK_ASSERT();
          NET_EPOCH_ASSERT();
  
          imo.imo_multicast_ifp  = vifp->v_ifp;
          imo.imo_multicast_ttl  = mtod(m, struct ip *)->ip_ttl - 1;
          imo.imo_multicast_loop = !!in_mcast_loop;
          imo.imo_multicast_vif  = -1;
          STAILQ_INIT(&imo.imo_head);
  
          /*
           * Re-entrancy should not be a problem here, because
           * the packets that we send out and are looped back at us
           * should get rejected because they appear to come from
           * the loopback interface, thus preventing looping.
           */
          error = ip_output(m, NULL, NULL, IP_FORWARDING, &imo, NULL);
          CTR3(KTR_IPMF, "%s: vif %td err %d", __func__,
              (ptrdiff_t)(vifp - V_viftable), error);
  }
  
  /*
   * Stubs for old RSVP socket shim implementation.
   */
  
  static int
  X_ip_rsvp_vif(struct socket *so __unused, struct sockopt *sopt __unused)
  {
  
          return (EOPNOTSUPP);
  }
  
  static void
  X_ip_rsvp_force_done(struct socket *so __unused)
  {
  
  }
  
  static int
  X_rsvp_input(struct mbuf **mp, int *offp, int proto)
  {
          struct mbuf *m;
  
          m = *mp;
          *mp = NULL;
          if (!V_rsvp_on)
                  m_freem(m);
          return (IPPROTO_DONE);
  }
  
  /*
   * Code for bandwidth monitors
   */
  
  /*
   * Define common interface for timeval-related methods
   */
  #define BW_TIMEVALCMP(tvp, uvp, cmp) timevalcmp((tvp), (uvp), cmp)
  #define BW_TIMEVALDECR(vvp, uvp) timevalsub((vvp), (uvp))
  #define BW_TIMEVALADD(vvp, uvp) timevaladd((vvp), (uvp))
  
  static uint32_t
  compute_bw_meter_flags(struct bw_upcall *req)
  {
      uint32_t flags = 0;
  
      if (req->bu_flags & BW_UPCALL_UNIT_PACKETS)
          flags |= BW_METER_UNIT_PACKETS;
      if (req->bu_flags & BW_UPCALL_UNIT_BYTES)
          flags |= BW_METER_UNIT_BYTES;
      if (req->bu_flags & BW_UPCALL_GEQ)
          flags |= BW_METER_GEQ;
      if (req->bu_flags & BW_UPCALL_LEQ)
          flags |= BW_METER_LEQ;
  
      return flags;
  }
  
  static void
  expire_bw_meter_leq(void *arg)
  {
          struct bw_meter *x = arg;
          struct timeval now;
          /*
           * INFO:
           * callout is always executed with MRW_WLOCK taken
           */
  
          CURVNET_SET((struct vnet *)x->arg);
  
          microtime(&now);
  
          /*
           * Test if we should deliver an upcall
           */
          if (((x->bm_flags & BW_METER_UNIT_PACKETS) &&
              (x->bm_measured.b_packets <= x->bm_threshold.b_packets)) ||
              ((x->bm_flags & BW_METER_UNIT_BYTES) &&
              (x->bm_measured.b_bytes <= x->bm_threshold.b_bytes))) {
                  /* Prepare an upcall for delivery */
                  bw_meter_prepare_upcall(x, &now);
          }
  
          /* Send all upcalls that are pending delivery */
          taskqueue_enqueue(V_task_queue, &V_task);
  
          /* Reset counters */
          x->bm_start_time = now;
          /* Spin lock has to be taken as ip_forward context
           * might modify these fields as well
           */
          mtx_lock_spin(&x->bm_spin);
          x->bm_measured.b_bytes = 0;
          x->bm_measured.b_packets = 0;
          mtx_unlock_spin(&x->bm_spin);
  
          callout_schedule(&x->bm_meter_callout, tvtohz(&x->bm_threshold.b_time));
  
          CURVNET_RESTORE();
  }
  
  /*
   * Add a bw_meter entry
   */
  static int
  add_bw_upcall(struct bw_upcall *req)
  {
          struct mfc *mfc;
          struct timeval delta = { BW_UPCALL_THRESHOLD_INTERVAL_MIN_SEC,
          BW_UPCALL_THRESHOLD_INTERVAL_MIN_USEC };
          struct timeval now;
          struct bw_meter *x, **bwm_ptr;
          uint32_t flags;
  
          if (!(V_mrt_api_config & MRT_MFC_BW_UPCALL))
                  return EOPNOTSUPP;
  
          /* Test if the flags are valid */
          if (!(req->bu_flags & (BW_UPCALL_UNIT_PACKETS | BW_UPCALL_UNIT_BYTES)))
                  return EINVAL;
          if (!(req->bu_flags & (BW_UPCALL_GEQ | BW_UPCALL_LEQ)))
                  return EINVAL;
          if ((req->bu_flags & (BW_UPCALL_GEQ | BW_UPCALL_LEQ))
                          == (BW_UPCALL_GEQ | BW_UPCALL_LEQ))
                  return EINVAL;
  
          /* Test if the threshold time interval is valid */
          if (BW_TIMEVALCMP(&req->bu_threshold.b_time, &delta, <))
                  return EINVAL;
  
          flags = compute_bw_meter_flags(req);
  
          /*
           * Find if we have already same bw_meter entry
           */
          MRW_WLOCK();
          mfc = mfc_find(&req->bu_src, &req->bu_dst);
          if (mfc == NULL) {
                  MRW_WUNLOCK();
                  return EADDRNOTAVAIL;
          }
  
          /* Choose an appropriate bw_meter list */
          if (req->bu_flags & BW_UPCALL_GEQ)
                  bwm_ptr = &mfc->mfc_bw_meter_geq;
          else
                  bwm_ptr = &mfc->mfc_bw_meter_leq;
  
          for (x = *bwm_ptr; x != NULL; x = x->bm_mfc_next) {
                  if ((BW_TIMEVALCMP(&x->bm_threshold.b_time,
                      &req->bu_threshold.b_time, ==))
                      && (x->bm_threshold.b_packets
                      == req->bu_threshold.b_packets)
                      && (x->bm_threshold.b_bytes
                      == req->bu_threshold.b_bytes)
                      && (x->bm_flags & BW_METER_USER_FLAGS)
                      == flags) {
                          MRW_WUNLOCK();
                          return 0; /* XXX Already installed */
                  }
          }
  
          /* Allocate the new bw_meter entry */
          x = (struct bw_meter*) malloc(sizeof(*x), M_BWMETER,
              M_ZERO | M_NOWAIT);
          if (x == NULL) {
                  MRW_WUNLOCK();
                  return ENOBUFS;
          }
  
          /* Set the new bw_meter entry */
          x->bm_threshold.b_time = req->bu_threshold.b_time;
          microtime(&now);
          x->bm_start_time = now;
          x->bm_threshold.b_packets = req->bu_threshold.b_packets;
          x->bm_threshold.b_bytes = req->bu_threshold.b_bytes;
          x->bm_measured.b_packets = 0;
          x->bm_measured.b_bytes = 0;
          x->bm_flags = flags;
          x->bm_time_next = NULL;
          x->bm_mfc = mfc;
          x->arg = curvnet;
          sprintf(x->bm_spin_name, "BM spin %p", x);
          mtx_init(&x->bm_spin, x->bm_spin_name, NULL, MTX_SPIN);
  
          /* For LEQ case create periodic callout */
          if (req->bu_flags & BW_UPCALL_LEQ) {
                  callout_init_rw(&x->bm_meter_callout, &mrouter_mtx, CALLOUT_SHAREDLOCK);
                  callout_reset(&x->bm_meter_callout, tvtohz(&x->bm_threshold.b_time),
                      expire_bw_meter_leq, x);
          }
  
          /* Add the new bw_meter entry to the front of entries for this MFC */
          x->bm_mfc_next = *bwm_ptr;
          *bwm_ptr = x;
  
          MRW_WUNLOCK();
  
          return 0;
  }
  
  static void
  free_bw_list(struct bw_meter *list)
  {
      while (list != NULL) {
          struct bw_meter *x = list;
  
          /* MRW_WLOCK must be held here */
          if (x->bm_flags & BW_METER_LEQ) {
                  callout_drain(&x->bm_meter_callout);
                  mtx_destroy(&x->bm_spin);
          }
  
          list = list->bm_mfc_next;
          free(x, M_BWMETER);
      }
  }
  
  /*
   * Delete one or multiple bw_meter entries
   */
  static int
  del_bw_upcall(struct bw_upcall *req)
  {
      struct mfc *mfc;
      struct bw_meter *x, **bwm_ptr;
  
      if (!(V_mrt_api_config & MRT_MFC_BW_UPCALL))
          return EOPNOTSUPP;
  
      MRW_WLOCK();
  
      /* Find the corresponding MFC entry */
      mfc = mfc_find(&req->bu_src, &req->bu_dst);
      if (mfc == NULL) {
          MRW_WUNLOCK();
          return EADDRNOTAVAIL;
      } else if (req->bu_flags & BW_UPCALL_DELETE_ALL) {
          /*
           * Delete all bw_meter entries for this mfc
           */
          struct bw_meter *list;
  
          /* Free LEQ list */
          list = mfc->mfc_bw_meter_leq;
          mfc->mfc_bw_meter_leq = NULL;
          free_bw_list(list);
  
          /* Free GEQ list */
          list = mfc->mfc_bw_meter_geq;
          mfc->mfc_bw_meter_geq = NULL;
          free_bw_list(list);
          MRW_WUNLOCK();
          return 0;
      } else {                    /* Delete a single bw_meter entry */
          struct bw_meter *prev;
          uint32_t flags = 0;
  
          flags = compute_bw_meter_flags(req);
  
          /* Choose an appropriate bw_meter list */
          if (req->bu_flags & BW_UPCALL_GEQ)
                  bwm_ptr = &mfc->mfc_bw_meter_geq;
          else
                  bwm_ptr = &mfc->mfc_bw_meter_leq;
  
          /* Find the bw_meter entry to delete */
          for (prev = NULL, x = *bwm_ptr; x != NULL;
               prev = x, x = x->bm_mfc_next) {
              if ((BW_TIMEVALCMP(&x->bm_threshold.b_time,
                                 &req->bu_threshold.b_time, ==)) &&
                  (x->bm_threshold.b_packets == req->bu_threshold.b_packets) &&
                  (x->bm_threshold.b_bytes == req->bu_threshold.b_bytes) &&
                  (x->bm_flags & BW_METER_USER_FLAGS) == flags)
                  break;
          }
          if (x != NULL) { /* Delete entry from the list for this MFC */
              if (prev != NULL)
                  prev->bm_mfc_next = x->bm_mfc_next;     /* remove from middle*/
              else
                  *bwm_ptr = x->bm_mfc_next;/* new head of list */
  
              if (req->bu_flags & BW_UPCALL_LEQ)
                      callout_stop(&x->bm_meter_callout);
  
              MRW_WUNLOCK();
              /* Free the bw_meter entry */
              free(x, M_BWMETER);
              return 0;
          } else {
              MRW_WUNLOCK();
              return EINVAL;
          }
      }
      /* NOTREACHED */
  }
  
  /*
   * Perform bandwidth measurement processing that may result in an upcall
   */
  static void
  bw_meter_geq_receive_packet(struct bw_meter *x, int plen, struct timeval *nowp)
  {
          struct timeval delta;
  
          MRW_LOCK_ASSERT();
  
          delta = *nowp;
          BW_TIMEVALDECR(&delta, &x->bm_start_time);
  
          /*
           * Processing for ">=" type of bw_meter entry.
           * bm_spin does not have to be hold here as in GEQ
           * case this is the only context accessing bm_measured.
           */
          if (BW_TIMEVALCMP(&delta, &x->bm_threshold.b_time, >)) {
              /* Reset the bw_meter entry */
              x->bm_start_time = *nowp;
              x->bm_measured.b_packets = 0;
              x->bm_measured.b_bytes = 0;
              x->bm_flags &= ~BW_METER_UPCALL_DELIVERED;
          }
  
          /* Record that a packet is received */
          x->bm_measured.b_packets++;
          x->bm_measured.b_bytes += plen;
  
          /*
           * Test if we should deliver an upcall
           */
          if (!(x->bm_flags & BW_METER_UPCALL_DELIVERED)) {
                  if (((x->bm_flags & BW_METER_UNIT_PACKETS) &&
                      (x->bm_measured.b_packets >= x->bm_threshold.b_packets)) ||
                      ((x->bm_flags & BW_METER_UNIT_BYTES) &&
                      (x->bm_measured.b_bytes >= x->bm_threshold.b_bytes))) {
                          /* Prepare an upcall for delivery */
                          bw_meter_prepare_upcall(x, nowp);
                          x->bm_flags |= BW_METER_UPCALL_DELIVERED;
                  }
          }
  }
  
  /*
   * Prepare a bandwidth-related upcall
   */
  static void
  bw_meter_prepare_upcall(struct bw_meter *x, struct timeval *nowp)
  {
          struct timeval delta;
          struct bw_upcall *u;
  
          MRW_LOCK_ASSERT();
  
          /*
           * Compute the measured time interval
           */
          delta = *nowp;
          BW_TIMEVALDECR(&delta, &x->bm_start_time);
  
          /*
           * Set the bw_upcall entry
           */
          u = malloc(sizeof(struct bw_upcall), M_MRTABLE, M_NOWAIT | M_ZERO);
          if (!u) {
                  log(LOG_WARNING, "bw_meter_prepare_upcall: cannot allocate entry\n");
                  return;
          }
          u->bu_src = x->bm_mfc->mfc_origin;
          u->bu_dst = x->bm_mfc->mfc_mcastgrp;
          u->bu_threshold.b_time = x->bm_threshold.b_time;
          u->bu_threshold.b_packets = x->bm_threshold.b_packets;
          u->bu_threshold.b_bytes = x->bm_threshold.b_bytes;
          u->bu_measured.b_time = delta;
          u->bu_measured.b_packets = x->bm_measured.b_packets;
          u->bu_measured.b_bytes = x->bm_measured.b_bytes;
          u->bu_flags = 0;
          if (x->bm_flags & BW_METER_UNIT_PACKETS)
                  u->bu_flags |= BW_UPCALL_UNIT_PACKETS;
          if (x->bm_flags & BW_METER_UNIT_BYTES)
                  u->bu_flags |= BW_UPCALL_UNIT_BYTES;
          if (x->bm_flags & BW_METER_GEQ)
                  u->bu_flags |= BW_UPCALL_GEQ;
          if (x->bm_flags & BW_METER_LEQ)
                  u->bu_flags |= BW_UPCALL_LEQ;
  
          if (buf_ring_enqueue(V_bw_upcalls_ring, u))
                  log(LOG_WARNING, "bw_meter_prepare_upcall: cannot enqueue upcall\n");
          if (buf_ring_count(V_bw_upcalls_ring) > (BW_UPCALLS_MAX / 2)) {
                  taskqueue_enqueue(V_task_queue, &V_task);
          }
  }
  /*
   * Send the pending bandwidth-related upcalls
   */
  static void
  bw_upcalls_send(void)
  {
      struct mbuf *m;
      int len = 0;
      struct bw_upcall *bu;
      struct sockaddr_in k_igmpsrc = { sizeof k_igmpsrc, AF_INET };
      static struct igmpmsg igmpmsg = { 0,                /* unused1 */
                                        0,                /* unused2 */
                                        IGMPMSG_BW_UPCALL,/* im_msgtype */
                                        0,                /* im_mbz  */
                                        0,                /* im_vif  */
                                        0,                /* unused3 */
                                        { 0 },            /* im_src  */
                                        { 0 } };          /* im_dst  */
  
      MRW_LOCK_ASSERT();
  
      if (buf_ring_empty(V_bw_upcalls_ring))
          return;
  
      /*
       * Allocate a new mbuf, initialize it with the header and
       * the payload for the pending calls.
       */
      m = m_gethdr(M_NOWAIT, MT_DATA);
      if (m == NULL) {
          log(LOG_WARNING, "bw_upcalls_send: cannot allocate mbuf\n");
          return;
      }
  
      m_copyback(m, 0, sizeof(struct igmpmsg), (caddr_t)&igmpmsg);
      len += sizeof(struct igmpmsg);
      while ((bu = buf_ring_dequeue_mc(V_bw_upcalls_ring)) != NULL) {
          m_copyback(m, len, sizeof(struct bw_upcall), (caddr_t)bu);
          len += sizeof(struct bw_upcall);
          free(bu, M_MRTABLE);
      }
  
      /*
       * Send the upcalls
       * XXX do we need to set the address in k_igmpsrc ?
       */
      MRTSTAT_INC(mrts_upcalls);
      if (socket_send(V_ip_mrouter, m, &k_igmpsrc) < 0) {
          log(LOG_WARNING, "bw_upcalls_send: ip_mrouter socket queue full\n");
          MRTSTAT_INC(mrts_upq_sockfull);
      }
  }
  
  /*
   * A periodic function for sending all upcalls that are pending delivery
   */
  static void
  expire_bw_upcalls_send(void *arg)
  {
      CURVNET_SET((struct vnet *) arg);
  
      /* This callout is run with MRW_RLOCK taken */
  
      bw_upcalls_send();
  
      callout_reset(&V_bw_upcalls_ch, BW_UPCALLS_PERIOD, expire_bw_upcalls_send,
          curvnet);
      CURVNET_RESTORE();
  }
  
  /*
   * End of bandwidth monitoring code
   */
  
  /*
   * Send the packet up to the user daemon, or eventually do kernel encapsulation
   *
   */
  static int
  pim_register_send(struct ip *ip, struct vif *vifp, struct mbuf *m,
      struct mfc *rt)
  {
      struct mbuf *mb_copy, *mm;
  
      /*
       * Do not send IGMP_WHOLEPKT notifications to userland, if the
       * rendezvous point was unspecified, and we were told not to.
       */
      if (pim_squelch_wholepkt != 0 && (V_mrt_api_config & MRT_MFC_RP) &&
          in_nullhost(rt->mfc_rp))
          return 0;
  
      mb_copy = pim_register_prepare(ip, m);
      if (mb_copy == NULL)
          return ENOBUFS;
  
      /*
       * Send all the fragments. Note that the mbuf for each fragment
       * is freed by the sending machinery.
       */
      for (mm = mb_copy; mm; mm = mb_copy) {
          mb_copy = mm->m_nextpkt;
          mm->m_nextpkt = 0;
          mm = m_pullup(mm, sizeof(struct ip));
          if (mm != NULL) {
              ip = mtod(mm, struct ip *);
              if ((V_mrt_api_config & MRT_MFC_RP) && !in_nullhost(rt->mfc_rp)) {
                  pim_register_send_rp(ip, vifp, mm, rt);
              } else {
                  pim_register_send_upcall(ip, vifp, mm, rt);
              }
          }
      }
  
      return 0;
  }
  
  /*
   * Return a copy of the data packet that is ready for PIM Register
   * encapsulation.
   * XXX: Note that in the returned copy the IP header is a valid one.
   */
  static struct mbuf *
  pim_register_prepare(struct ip *ip, struct mbuf *m)
  {
      struct mbuf *mb_copy = NULL;
      int mtu;
  
      /* Take care of delayed checksums */
      if (m->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
          in_delayed_cksum(m);
          m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
      }
  
      /*
       * Copy the old packet & pullup its IP header into the
       * new mbuf so we can modify it.
       */
      mb_copy = m_copypacket(m, M_NOWAIT);
      if (mb_copy == NULL)
          return NULL;
      mb_copy = m_pullup(mb_copy, ip->ip_hl << 2);
      if (mb_copy == NULL)
          return NULL;
  
      /* take care of the TTL */
      ip = mtod(mb_copy, struct ip *);
      --ip->ip_ttl;
  
      /* Compute the MTU after the PIM Register encapsulation */
      mtu = 0xffff - sizeof(pim_encap_iphdr) - sizeof(pim_encap_pimhdr);
  
      if (ntohs(ip->ip_len) <= mtu) {
          /* Turn the IP header into a valid one */
          ip->ip_sum = 0;
          ip->ip_sum = in_cksum(mb_copy, ip->ip_hl << 2);
      } else {
          /* Fragment the packet */
          mb_copy->m_pkthdr.csum_flags |= CSUM_IP;
          if (ip_fragment(ip, &mb_copy, mtu, 0) != 0) {
              m_freem(mb_copy);
              return NULL;
          }
      }
      return mb_copy;
  }
  
  /*
   * Send an upcall with the data packet to the user-level process.
   */
  static int
  pim_register_send_upcall(struct ip *ip, struct vif *vifp,
      struct mbuf *mb_copy, struct mfc *rt)
  {
      struct mbuf *mb_first;
      int len = ntohs(ip->ip_len);
      struct igmpmsg *im;
      struct sockaddr_in k_igmpsrc = { sizeof k_igmpsrc, AF_INET };
  
      MRW_LOCK_ASSERT();
  
      /*
       * Add a new mbuf with an upcall header
       */
      mb_first = m_gethdr(M_NOWAIT, MT_DATA);
      if (mb_first == NULL) {
          m_freem(mb_copy);
          return ENOBUFS;
      }
      mb_first->m_data += max_linkhdr;
      mb_first->m_pkthdr.len = len + sizeof(struct igmpmsg);
      mb_first->m_len = sizeof(struct igmpmsg);
      mb_first->m_next = mb_copy;
  
      /* Send message to routing daemon */
      im = mtod(mb_first, struct igmpmsg *);
      im->im_msgtype      = IGMPMSG_WHOLEPKT;
      im->im_mbz          = 0;
      im->im_vif          = vifp - V_viftable;
      im->im_src          = ip->ip_src;
      im->im_dst          = ip->ip_dst;
  
      k_igmpsrc.sin_addr  = ip->ip_src;
  
      MRTSTAT_INC(mrts_upcalls);
  
      if (socket_send(V_ip_mrouter, mb_first, &k_igmpsrc) < 0) {
          CTR1(KTR_IPMF, "%s: socket queue full", __func__);
          MRTSTAT_INC(mrts_upq_sockfull);
          return ENOBUFS;
      }
  
      /* Keep statistics */
      PIMSTAT_INC(pims_snd_registers_msgs);
      PIMSTAT_ADD(pims_snd_registers_bytes, len);
  
      return 0;
  }
  
  /*
   * Encapsulate the data packet in PIM Register message and send it to the RP.
   */
  static int
  pim_register_send_rp(struct ip *ip, struct vif *vifp, struct mbuf *mb_copy,
      struct mfc *rt)
  {
      struct mbuf *mb_first;
      struct ip *ip_outer;
      struct pim_encap_pimhdr *pimhdr;
      int len = ntohs(ip->ip_len);
      vifi_t vifi = rt->mfc_parent;
  
      MRW_LOCK_ASSERT();
  
      if ((vifi >= V_numvifs) || in_nullhost(V_viftable[vifi].v_lcl_addr)) {
          m_freem(mb_copy);
          return EADDRNOTAVAIL;           /* The iif vif is invalid */
      }
  
      /*
       * Add a new mbuf with the encapsulating header
       */
      mb_first = m_gethdr(M_NOWAIT, MT_DATA);
      if (mb_first == NULL) {
          m_freem(mb_copy);
          return ENOBUFS;
      }
      mb_first->m_data += max_linkhdr;
      mb_first->m_len = sizeof(pim_encap_iphdr) + sizeof(pim_encap_pimhdr);
      mb_first->m_next = mb_copy;
  
      mb_first->m_pkthdr.len = len + mb_first->m_len;
  
      /*
       * Fill in the encapsulating IP and PIM header
       */
      ip_outer = mtod(mb_first, struct ip *);
      *ip_outer = pim_encap_iphdr;
      ip_outer->ip_len = htons(len + sizeof(pim_encap_iphdr) +
          sizeof(pim_encap_pimhdr));
      ip_outer->ip_src = V_viftable[vifi].v_lcl_addr;
      ip_outer->ip_dst = rt->mfc_rp;
      /*
       * Copy the inner header TOS to the outer header, and take care of the
       * IP_DF bit.
       */
      ip_outer->ip_tos = ip->ip_tos;
      if (ip->ip_off & htons(IP_DF))
          ip_outer->ip_off |= htons(IP_DF);
      ip_fillid(ip_outer);
      pimhdr = (struct pim_encap_pimhdr *)((caddr_t)ip_outer
                                           + sizeof(pim_encap_iphdr));
      *pimhdr = pim_encap_pimhdr;
      /* If the iif crosses a border, set the Border-bit */
      if (rt->mfc_flags[vifi] & MRT_MFC_FLAGS_BORDER_VIF & V_mrt_api_config)
          pimhdr->flags |= htonl(PIM_BORDER_REGISTER);
  
      mb_first->m_data += sizeof(pim_encap_iphdr);
      pimhdr->pim.pim_cksum = in_cksum(mb_first, sizeof(pim_encap_pimhdr));
      mb_first->m_data -= sizeof(pim_encap_iphdr);
  
      send_packet(vifp, mb_first);
  
      /* Keep statistics */
      PIMSTAT_INC(pims_snd_registers_msgs);
      PIMSTAT_ADD(pims_snd_registers_bytes, len);
  
      return 0;
  }
  
  /*
   * pim_encapcheck() is called by the encap4_input() path at runtime to
   * determine if a packet is for PIM; allowing PIM to be dynamically loaded
   * into the kernel.
   */
  static int
  pim_encapcheck(const struct mbuf *m __unused, int off __unused,
      int proto __unused, void *arg __unused)
  {
  
      KASSERT(proto == IPPROTO_PIM, ("not for IPPROTO_PIM"));
      return (8);         /* claim the datagram. */
  }
  
  /*
   * PIM-SMv2 and PIM-DM messages processing.
   * Receives and verifies the PIM control messages, and passes them
   * up to the listening socket, using rip_input().
   * The only message with special processing is the PIM_REGISTER message
   * (used by PIM-SM): the PIM header is stripped off, and the inner packet
   * is passed to if_simloop().
   */
  static int
  pim_input(struct mbuf *m, int off, int proto, void *arg __unused)
  {
      struct ip *ip = mtod(m, struct ip *);
      struct pim *pim;
      int iphlen = off;
      int minlen;
      int datalen = ntohs(ip->ip_len) - iphlen;
      int ip_tos;
  
      /* Keep statistics */
      PIMSTAT_INC(pims_rcv_total_msgs);
      PIMSTAT_ADD(pims_rcv_total_bytes, datalen);
  
      /*
       * Validate lengths
       */
      if (datalen < PIM_MINLEN) {
          PIMSTAT_INC(pims_rcv_tooshort);
          CTR3(KTR_IPMF, "%s: short packet (%d) from 0x%08x",
              __func__, datalen, ntohl(ip->ip_src.s_addr));
          m_freem(m);
          return (IPPROTO_DONE);
      }
  
      /*
       * If the packet is at least as big as a REGISTER, go agead
       * and grab the PIM REGISTER header size, to avoid another
       * possible m_pullup() later.
       *
       * PIM_MINLEN       == pimhdr + u_int32_t == 4 + 4 = 8
       * PIM_REG_MINLEN   == pimhdr + reghdr + encap_iphdr == 4 + 4 + 20 = 28
       */
      minlen = iphlen + (datalen >= PIM_REG_MINLEN ? PIM_REG_MINLEN : PIM_MINLEN);
      /*
       * Get the IP and PIM headers in contiguous memory, and
       * possibly the PIM REGISTER header.
       */
      if (m->m_len < minlen && (m = m_pullup(m, minlen)) == NULL) {
          CTR1(KTR_IPMF, "%s: m_pullup() failed", __func__);
          return (IPPROTO_DONE);
      }
  
      /* m_pullup() may have given us a new mbuf so reset ip. */
      ip = mtod(m, struct ip *);
      ip_tos = ip->ip_tos;
  
      /* adjust mbuf to point to the PIM header */
      m->m_data += iphlen;
      m->m_len  -= iphlen;
      pim = mtod(m, struct pim *);
  
      /*
       * Validate checksum. If PIM REGISTER, exclude the data packet.
       *
       * XXX: some older PIMv2 implementations don't make this distinction,
       * so for compatibility reason perform the checksum over part of the
       * message, and if error, then over the whole message.
       */
      if (PIM_VT_T(pim->pim_vt) == PIM_REGISTER && in_cksum(m, PIM_MINLEN) == 0) {
          /* do nothing, checksum okay */
      } else if (in_cksum(m, datalen)) {
          PIMSTAT_INC(pims_rcv_badsum);
          CTR1(KTR_IPMF, "%s: invalid checksum", __func__);
          m_freem(m);
          return (IPPROTO_DONE);
      }
  
      /* PIM version check */
      if (PIM_VT_V(pim->pim_vt) < PIM_VERSION) {
          PIMSTAT_INC(pims_rcv_badversion);
          CTR3(KTR_IPMF, "%s: bad version %d expect %d", __func__,
              (int)PIM_VT_V(pim->pim_vt), PIM_VERSION);
          m_freem(m);
          return (IPPROTO_DONE);
      }
  
      /* restore mbuf back to the outer IP */
      m->m_data -= iphlen;
      m->m_len  += iphlen;
  
      if (PIM_VT_T(pim->pim_vt) == PIM_REGISTER) {
          /*
           * Since this is a REGISTER, we'll make a copy of the register
           * headers ip + pim + u_int32 + encap_ip, to be passed up to the
           * routing daemon.
           */
          struct sockaddr_in dst = { sizeof(dst), AF_INET };
          struct mbuf *mcp;
          struct ip *encap_ip;
          u_int32_t *reghdr;
          struct ifnet *vifp;
  
          MRW_RLOCK();
          if ((V_reg_vif_num >= V_numvifs) || (V_reg_vif_num == VIFI_INVALID)) {
              MRW_RUNLOCK();
              CTR2(KTR_IPMF, "%s: register vif not set: %d", __func__,
                  (int)V_reg_vif_num);
              m_freem(m);
              return (IPPROTO_DONE);
          }
          /* XXX need refcnt? */
          vifp = V_viftable[V_reg_vif_num].v_ifp;
          MRW_RUNLOCK();
  
          /*
           * Validate length
           */
          if (datalen < PIM_REG_MINLEN) {
              PIMSTAT_INC(pims_rcv_tooshort);
              PIMSTAT_INC(pims_rcv_badregisters);
              CTR1(KTR_IPMF, "%s: register packet size too small", __func__);
              m_freem(m);
              return (IPPROTO_DONE);
          }
  
          reghdr = (u_int32_t *)(pim + 1);
          encap_ip = (struct ip *)(reghdr + 1);
  
          CTR3(KTR_IPMF, "%s: register: encap ip src 0x%08x len %d",
              __func__, ntohl(encap_ip->ip_src.s_addr),
              ntohs(encap_ip->ip_len));
  
          /* verify the version number of the inner packet */
          if (encap_ip->ip_v != IPVERSION) {
              PIMSTAT_INC(pims_rcv_badregisters);
              CTR1(KTR_IPMF, "%s: bad encap ip version", __func__);
              m_freem(m);
              return (IPPROTO_DONE);
          }
  
          /* verify the inner packet is destined to a mcast group */
          if (!IN_MULTICAST(ntohl(encap_ip->ip_dst.s_addr))) {
              PIMSTAT_INC(pims_rcv_badregisters);
              CTR2(KTR_IPMF, "%s: bad encap ip dest 0x%08x", __func__,
                  ntohl(encap_ip->ip_dst.s_addr));
              m_freem(m);
              return (IPPROTO_DONE);
          }
  
          /* If a NULL_REGISTER, pass it to the daemon */
          if ((ntohl(*reghdr) & PIM_NULL_REGISTER))
              goto pim_input_to_daemon;
  
          /*
           * Copy the TOS from the outer IP header to the inner IP header.
           */
          if (encap_ip->ip_tos != ip_tos) {
              /* Outer TOS -> inner TOS */
              encap_ip->ip_tos = ip_tos;
              /* Recompute the inner header checksum. Sigh... */
  
              /* adjust mbuf to point to the inner IP header */
              m->m_data += (iphlen + PIM_MINLEN);
              m->m_len  -= (iphlen + PIM_MINLEN);
  
              encap_ip->ip_sum = 0;
              encap_ip->ip_sum = in_cksum(m, encap_ip->ip_hl << 2);
  
              /* restore mbuf to point back to the outer IP header */
              m->m_data -= (iphlen + PIM_MINLEN);
              m->m_len  += (iphlen + PIM_MINLEN);
          }
  
          /*
           * Decapsulate the inner IP packet and loopback to forward it
           * as a normal multicast packet. Also, make a copy of the
           *     outer_iphdr + pimhdr + reghdr + encap_iphdr
           * to pass to the daemon later, so it can take the appropriate
           * actions (e.g., send back PIM_REGISTER_STOP).
           * XXX: here m->m_data points to the outer IP header.
           */
          mcp = m_copym(m, 0, iphlen + PIM_REG_MINLEN, M_NOWAIT);
          if (mcp == NULL) {
              CTR1(KTR_IPMF, "%s: m_copym() failed", __func__);
              m_freem(m);
              return (IPPROTO_DONE);
          }
  
          /* Keep statistics */
          /* XXX: registers_bytes include only the encap. mcast pkt */
          PIMSTAT_INC(pims_rcv_registers_msgs);
          PIMSTAT_ADD(pims_rcv_registers_bytes, ntohs(encap_ip->ip_len));
  
          /*
           * forward the inner ip packet; point m_data at the inner ip.
           */
          m_adj(m, iphlen + PIM_MINLEN);
  
          CTR4(KTR_IPMF,
              "%s: forward decap'd REGISTER: src %lx dst %lx vif %d",
              __func__,
              (u_long)ntohl(encap_ip->ip_src.s_addr),
              (u_long)ntohl(encap_ip->ip_dst.s_addr),
              (int)V_reg_vif_num);
  
          /* NB: vifp was collected above; can it change on us? */
          if_simloop(vifp, m, dst.sin_family, 0);
  
          /* prepare the register head to send to the mrouting daemon */
          m = mcp;
      }
  
  pim_input_to_daemon:
      /*
       * Pass the PIM message up to the daemon; if it is a Register message,
       * pass the 'head' only up to the daemon. This includes the
       * outer IP header, PIM header, PIM-Register header and the
       * inner IP header.
       * XXX: the outer IP header pkt size of a Register is not adjust to
       * reflect the fact that the inner multicast data is truncated.
       */
      return (rip_input(&m, &off, proto));
  }
  
  static int
  sysctl_mfctable(SYSCTL_HANDLER_ARGS)
  {
          struct mfc      *rt;
          int              error, i;
  
          if (req->newptr)
                  return (EPERM);
          if (V_mfchashtbl == NULL)       /* XXX unlocked */
                  return (0);
          error = sysctl_wire_old_buffer(req, 0);
          if (error)
                  return (error);
  
          MRW_RLOCK();
          for (i = 0; i < mfchashsize; i++) {
                  LIST_FOREACH(rt, &V_mfchashtbl[i], mfc_hash) {
                          error = SYSCTL_OUT(req, rt, sizeof(struct mfc));
                          if (error)
                                  goto out_locked;
                  }
          }
  out_locked:
          MRW_RUNLOCK();
          return (error);
  }
  
  static SYSCTL_NODE(_net_inet_ip, OID_AUTO, mfctable,
      CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_mfctable,
      "IPv4 Multicast Forwarding Table "
      "(struct *mfc[mfchashsize], netinet/ip_mroute.h)");
  
  static int
  sysctl_viflist(SYSCTL_HANDLER_ARGS)
  {
          int error, i;
  
          if (req->newptr)
                  return (EPERM);
          if (V_viftable == NULL)         /* XXX unlocked */
                  return (0);
          error = sysctl_wire_old_buffer(req, MROUTE_VIF_SYSCTL_LEN * MAXVIFS);
          if (error)
                  return (error);
  
          MRW_RLOCK();
          /* Copy out user-visible portion of vif entry. */
          for (i = 0; i < MAXVIFS; i++) {
                  error = SYSCTL_OUT(req, &V_viftable[i], MROUTE_VIF_SYSCTL_LEN);
                  if (error)
                          break;
          }
          MRW_RUNLOCK();
          return (error);
  }
  
  SYSCTL_PROC(_net_inet_ip, OID_AUTO, viftable,
      CTLTYPE_OPAQUE | CTLFLAG_VNET | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0,
      sysctl_viflist, "S,vif[MAXVIFS]",
      "IPv4 Multicast Interfaces (struct vif[MAXVIFS], netinet/ip_mroute.h)");
  
  static void
  vnet_mroute_init(const void *unused __unused)
  {
  
          V_nexpire = malloc(mfchashsize, M_MRTABLE, M_WAITOK|M_ZERO);
  
          V_viftable = mallocarray(MAXVIFS, sizeof(*V_viftable),
              M_MRTABLE, M_WAITOK|M_ZERO);
  
          callout_init_rw(&V_expire_upcalls_ch, &mrouter_mtx, 0);
          callout_init_rw(&V_bw_upcalls_ch, &mrouter_mtx, 0);
  
          /* Prepare taskqueue */
          V_task_queue = taskqueue_create_fast("ip_mroute_tskq", M_NOWAIT,
                      taskqueue_thread_enqueue, &V_task_queue);
          taskqueue_start_threads(&V_task_queue, 1, PI_NET, "ip_mroute_tskq task");
  }
  
  VNET_SYSINIT(vnet_mroute_init, SI_SUB_PROTO_MC, SI_ORDER_ANY, vnet_mroute_init,
          NULL);
  
  static void
  vnet_mroute_uninit(const void *unused __unused)
  {
  
          /* Taskqueue should be cancelled and drained before freeing */
          taskqueue_free(V_task_queue);
  
          free(V_viftable, M_MRTABLE);
          free(V_nexpire, M_MRTABLE);
          V_nexpire = NULL;
  }
  
  VNET_SYSUNINIT(vnet_mroute_uninit, SI_SUB_PROTO_MC, SI_ORDER_MIDDLE,
          vnet_mroute_uninit, NULL);
  
  static int
  ip_mroute_modevent(module_t mod, int type, void *unused)
  {
  
      switch (type) {
      case MOD_LOAD:
          MRW_LOCK_INIT();
  
          if_detach_event_tag = EVENTHANDLER_REGISTER(ifnet_departure_event,
              if_detached_event, NULL, EVENTHANDLER_PRI_ANY);
          if (if_detach_event_tag == NULL) {
                  printf("ip_mroute: unable to register "
                      "ifnet_departure_event handler\n");
                  MRW_LOCK_DESTROY();
                  return (EINVAL);
          }
  
          mfchashsize = MFCHASHSIZE;
          if (TUNABLE_ULONG_FETCH("net.inet.ip.mfchashsize", &mfchashsize) &&
              !powerof2(mfchashsize)) {
                  printf("WARNING: %s not a power of 2; using default\n",
                      "net.inet.ip.mfchashsize");
                  mfchashsize = MFCHASHSIZE;
          }
  
          pim_squelch_wholepkt = 0;
          TUNABLE_ULONG_FETCH("net.inet.pim.squelch_wholepkt",
              &pim_squelch_wholepkt);
  
          pim_encap_cookie = ip_encap_attach(&ipv4_encap_cfg, NULL, M_WAITOK);
          if (pim_encap_cookie == NULL) {
                  printf("ip_mroute: unable to attach pim encap\n");
                  MRW_LOCK_DESTROY();
                  return (EINVAL);
          }
  
          ip_mcast_src = X_ip_mcast_src;
          ip_mforward = X_ip_mforward;
          ip_mrouter_done = X_ip_mrouter_done;
          ip_mrouter_get = X_ip_mrouter_get;
          ip_mrouter_set = X_ip_mrouter_set;
  
          ip_rsvp_force_done = X_ip_rsvp_force_done;
          ip_rsvp_vif = X_ip_rsvp_vif;
  
          legal_vif_num = X_legal_vif_num;
          mrt_ioctl = X_mrt_ioctl;
          rsvp_input_p = X_rsvp_input;
          break;
  
      case MOD_UNLOAD:
          /*
           * Typically module unload happens after the user-level
           * process has shutdown the kernel services (the check
           * below insures someone can't just yank the module out
           * from under a running process).  But if the module is
           * just loaded and then unloaded w/o starting up a user
           * process we still need to cleanup.
           */
          MRW_WLOCK();
          if (ip_mrouter_cnt != 0) {
              MRW_WUNLOCK();
              return (EINVAL);
          }
          ip_mrouter_unloading = 1;
          MRW_WUNLOCK();
  
          EVENTHANDLER_DEREGISTER(ifnet_departure_event, if_detach_event_tag);
  
          if (pim_encap_cookie) {
              ip_encap_detach(pim_encap_cookie);
              pim_encap_cookie = NULL;
          }
  
          ip_mcast_src = NULL;
          ip_mforward = NULL;
          ip_mrouter_done = NULL;
          ip_mrouter_get = NULL;
          ip_mrouter_set = NULL;
  
          ip_rsvp_force_done = NULL;
          ip_rsvp_vif = NULL;
  
          legal_vif_num = NULL;
          mrt_ioctl = NULL;
          rsvp_input_p = NULL;
  
          MRW_LOCK_DESTROY();
          break;
  
      default:
          return EOPNOTSUPP;
      }
      return 0;
  }
  
  static moduledata_t ip_mroutemod = {
      "ip_mroute",
      ip_mroute_modevent,
      0
  };
  
  DECLARE_MODULE(ip_mroute, ip_mroutemod, SI_SUB_PROTO_MC, SI_ORDER_MIDDLE);

Cache object: 8eb484c508a46110c7b87dc55b5c6e82