FreeBSD/Linux Kernel Cross Reference
sys/net/netisr.c

     /*
      * Copyright (c) 2003, 2004 Matthew Dillon. All rights reserved.
      * Copyright (c) 2003, 2004 Jeffrey M. Hsu.  All rights reserved.
      * Copyright (c) 2003 Jonathan Lemon.  All rights reserved.
      * Copyright (c) 2003, 2004 The DragonFly Project.  All rights reserved.
      *
      * This code is derived from software contributed to The DragonFly Project
      * by Jonathan Lemon, Jeffrey M. Hsu, and Matthew Dillon.
      *
     * Jonathan Lemon gave Jeffrey Hsu permission to combine his copyright
     * into this one around July 8 2004.
     *
     * 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 DragonFly Project nor the names of its
     *    contributors may be used to endorse or promote products derived
     *    from this software without specific, prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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
     * COPYRIGHT HOLDERS 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.
     */
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/malloc.h>
    #include <sys/msgport.h>
    #include <sys/proc.h>
    #include <sys/interrupt.h>
    #include <sys/socket.h>
    #include <sys/sysctl.h>
    #include <sys/socketvar.h>
    #include <net/if.h>
    #include <net/if_var.h>
    #include <net/netisr2.h>
    #include <machine/cpufunc.h>
    #include <machine/smp.h>
    
    #include <sys/thread2.h>
    #include <sys/msgport2.h>
    #include <net/netmsg2.h>
    #include <sys/mplock2.h>
    
    static void netmsg_service_loop(void *arg);
    static void netisr_hashfn0(struct mbuf **mp, int hoff);
    static void netisr_nohashck(struct mbuf *, const struct pktinfo *);
    
    struct netmsg_port_registration {
            TAILQ_ENTRY(netmsg_port_registration) npr_entry;
            lwkt_port_t     npr_port;
    };
    
    struct netmsg_rollup {
            TAILQ_ENTRY(netmsg_rollup) ru_entry;
            netisr_ru_t     ru_func;
            int             ru_prio;
    };
    
    struct netmsg_barrier {
            struct netmsg_base      base;
            volatile cpumask_t      *br_cpumask;
            volatile uint32_t       br_done;
    };
    
    #define NETISR_BR_NOTDONE       0x1
    #define NETISR_BR_WAITDONE      0x80000000
    
    struct netisr_barrier {
            struct netmsg_barrier   *br_msgs[MAXCPU];
            int                     br_isset;
    };
    
    static struct netisr netisrs[NETISR_MAX];
    static TAILQ_HEAD(,netmsg_port_registration) netreglist;
    static TAILQ_HEAD(,netmsg_rollup) netrulist;
    
    /* Per-CPU thread to handle any protocol.  */
    struct thread netisr_cpu[MAXCPU];
    lwkt_port netisr_afree_rport;
    lwkt_port netisr_afree_free_so_rport;
    lwkt_port netisr_adone_rport;
    lwkt_port netisr_apanic_rport;
    lwkt_port netisr_sync_port;
   
   static int (*netmsg_fwd_port_fn)(lwkt_port_t, lwkt_msg_t);
   
   SYSCTL_NODE(_net, OID_AUTO, netisr, CTLFLAG_RW, 0, "netisr");
   
   /*
    * netisr_afree_rport replymsg function, only used to handle async
    * messages which the sender has abandoned to their fate.
    */
   static void
   netisr_autofree_reply(lwkt_port_t port, lwkt_msg_t msg)
   {
           kfree(msg, M_LWKTMSG);
   }
   
   static void
   netisr_autofree_free_so_reply(lwkt_port_t port, lwkt_msg_t msg)
   {
           sofree(((netmsg_t)msg)->base.nm_so);
           kfree(msg, M_LWKTMSG);
   }
   
   /*
    * We need a custom putport function to handle the case where the
    * message target is the current thread's message port.  This case
    * can occur when the TCP or UDP stack does a direct callback to NFS and NFS
    * then turns around and executes a network operation synchronously.
    *
    * To prevent deadlocking, we must execute these self-referential messages
    * synchronously, effectively turning the message into a glorified direct
    * procedure call back into the protocol stack.  The operation must be
    * complete on return or we will deadlock, so panic if it isn't.
    *
    * However, the target function is under no obligation to immediately
    * reply the message.  It may forward it elsewhere.
    */
   static int
   netmsg_put_port(lwkt_port_t port, lwkt_msg_t lmsg)
   {
           netmsg_base_t nmsg = (void *)lmsg;
   
           if ((lmsg->ms_flags & MSGF_SYNC) && port == &curthread->td_msgport) {
                   nmsg->nm_dispatch((netmsg_t)nmsg);
                   return(EASYNC);
           } else {
                   return(netmsg_fwd_port_fn(port, lmsg));
           }
   }
   
   /*
    * UNIX DOMAIN sockets still have to run their uipc functions synchronously,
    * because they depend on the user proc context for a number of things 
    * (like creds) which we have not yet incorporated into the message structure.
    *
    * However, we maintain or message/port abstraction.  Having a special 
    * synchronous port which runs the commands synchronously gives us the
    * ability to serialize operations in one place later on when we start
    * removing the BGL.
    */
   static int
   netmsg_sync_putport(lwkt_port_t port, lwkt_msg_t lmsg)
   {
           netmsg_base_t nmsg = (void *)lmsg;
   
           KKASSERT((lmsg->ms_flags & MSGF_DONE) == 0);
   
           lmsg->ms_target_port = port;    /* required for abort */
           nmsg->nm_dispatch((netmsg_t)nmsg);
           return(EASYNC);
   }
   
   static void
   netisr_init(void)
   {
           int i;
   
           TAILQ_INIT(&netreglist);
           TAILQ_INIT(&netrulist);
   
           /*
            * Create default per-cpu threads for generic protocol handling.
            */
           for (i = 0; i < ncpus; ++i) {
                   lwkt_create(netmsg_service_loop, NULL, NULL,
                               &netisr_cpu[i],
                               TDF_NOSTART|TDF_FORCE_SPINPORT|TDF_FIXEDCPU,
                               i, "netisr_cpu %d", i);
                   netmsg_service_port_init(&netisr_cpu[i].td_msgport);
                   lwkt_schedule(&netisr_cpu[i]);
           }
   
           /*
            * The netisr_afree_rport is a special reply port which automatically
            * frees the replied message.  The netisr_adone_rport simply marks
            * the message as being done.  The netisr_apanic_rport panics if
            * the message is replied to.
            */
           lwkt_initport_replyonly(&netisr_afree_rport, netisr_autofree_reply);
           lwkt_initport_replyonly(&netisr_afree_free_so_rport,
                                   netisr_autofree_free_so_reply);
           lwkt_initport_replyonly_null(&netisr_adone_rport);
           lwkt_initport_panic(&netisr_apanic_rport);
   
           /*
            * The netisr_syncport is a special port which executes the message
            * synchronously and waits for it if EASYNC is returned.
            */
           lwkt_initport_putonly(&netisr_sync_port, netmsg_sync_putport);
   }
   
   SYSINIT(netisr, SI_SUB_PRE_DRIVERS, SI_ORDER_FIRST, netisr_init, NULL);
   
   /*
    * Finish initializing the message port for a netmsg service.  This also
    * registers the port for synchronous cleanup operations such as when an
    * ifnet is being destroyed.  There is no deregistration API yet.
    */
   void
   netmsg_service_port_init(lwkt_port_t port)
   {
           struct netmsg_port_registration *reg;
   
           /*
            * Override the putport function.  Our custom function checks for
            * self-references and executes such commands synchronously.
            */
           if (netmsg_fwd_port_fn == NULL)
                   netmsg_fwd_port_fn = port->mp_putport;
           KKASSERT(netmsg_fwd_port_fn == port->mp_putport);
           port->mp_putport = netmsg_put_port;
   
           /*
            * Keep track of ports using the netmsg API so we can synchronize
            * certain operations (such as freeing an ifnet structure) across all
            * consumers.
            */
           reg = kmalloc(sizeof(*reg), M_TEMP, M_WAITOK|M_ZERO);
           reg->npr_port = port;
           TAILQ_INSERT_TAIL(&netreglist, reg, npr_entry);
   }
   
   /*
    * This function synchronizes the caller with all netmsg services.  For
    * example, if an interface is being removed we must make sure that all
    * packets related to that interface complete processing before the structure
    * can actually be freed.  This sort of synchronization is an alternative to
    * ref-counting the netif, removing the ref counting overhead in favor of
    * placing additional overhead in the netif freeing sequence (where it is
    * inconsequential).
    */
   void
   netmsg_service_sync(void)
   {
           struct netmsg_port_registration *reg;
           struct netmsg_base smsg;
   
           netmsg_init(&smsg, NULL, &curthread->td_msgport, 0, netmsg_sync_handler);
   
           TAILQ_FOREACH(reg, &netreglist, npr_entry) {
                   lwkt_domsg(reg->npr_port, &smsg.lmsg, 0);
           }
   }
   
   /*
    * The netmsg function simply replies the message.  API semantics require
    * EASYNC to be returned if the netmsg function disposes of the message.
    */
   void
   netmsg_sync_handler(netmsg_t msg)
   {
           lwkt_replymsg(&msg->lmsg, 0);
   }
   
   /*
    * Generic netmsg service loop.  Some protocols may roll their own but all
    * must do the basic command dispatch function call done here.
    */
   static void
   netmsg_service_loop(void *arg)
   {
           struct netmsg_rollup *ru;
           netmsg_base_t msg;
           thread_t td = curthread;
           int limit;
   
           td->td_type = TD_TYPE_NETISR;
   
           while ((msg = lwkt_waitport(&td->td_msgport, 0))) {
                   /*
                    * Run up to 512 pending netmsgs.
                    */
                   limit = 512;
                   do {
                           KASSERT(msg->nm_dispatch != NULL,
                                   ("netmsg_service isr %d badmsg",
                                   msg->lmsg.u.ms_result));
                           if (msg->nm_so &&
                               msg->nm_so->so_port != &td->td_msgport) {
                                   /*
                                    * Sockets undergoing connect or disconnect
                                    * ops can change ports on us.  Chase the
                                    * port.
                                    */
   #ifdef foo
                                   /*
                                    * This could be quite common for protocols
                                    * which support asynchronous pru_connect,
                                    * e.g. TCP, so kprintf socket port chasing
                                    * could be too verbose for the console.
                                    */
                                   kprintf("netmsg_service_loop: Warning, "
                                           "port changed so=%p\n", msg->nm_so);
   #endif
                                   lwkt_forwardmsg(msg->nm_so->so_port,
                                                   &msg->lmsg);
                           } else {
                                   /*
                                    * We are on the correct port, dispatch it.
                                    */
                                   msg->nm_dispatch((netmsg_t)msg);
                           }
                           if (--limit == 0)
                                   break;
                   } while ((msg = lwkt_getport(&td->td_msgport)) != NULL);
   
                   /*
                    * Run all registered rollup functions for this cpu
                    * (e.g. tcp_willblock()).
                    */
                   TAILQ_FOREACH(ru, &netrulist, ru_entry)
                           ru->ru_func();
           }
   }
   
   /*
    * Forward a packet to a netisr service function.
    *
    * If the packet has not been assigned to a protocol thread we call
    * the port characterization function to assign it.  The caller must
    * clear M_HASH (or not have set it in the first place) if the caller
    * wishes the packet to be recharacterized.
    */
   int
   netisr_queue(int num, struct mbuf *m)
   {
           struct netisr *ni;
           struct netmsg_packet *pmsg;
           lwkt_port_t port;
   
           KASSERT((num > 0 && num <= NELEM(netisrs)),
                   ("Bad isr %d", num));
   
           ni = &netisrs[num];
           if (ni->ni_handler == NULL) {
                   kprintf("Unregistered isr %d\n", num);
                   m_freem(m);
                   return (EIO);
           }
   
           /*
            * Figure out which protocol thread to send to.  This does not
            * have to be perfect but performance will be really good if it
            * is correct.  Major protocol inputs such as ip_input() will
            * re-characterize the packet as necessary.
            */
           if ((m->m_flags & M_HASH) == 0) {
                   ni->ni_hashfn(&m, 0);
                   if (m == NULL) {
                           m_freem(m);
                           return (EIO);
                   }
                   if ((m->m_flags & M_HASH) == 0) {
                           kprintf("netisr_queue(%d): packet hash failed\n", num);
                           m_freem(m);
                           return (EIO);
                   }
           }
   
           /*
            * Get the protocol port based on the packet hash, initialize
            * the netmsg, and send it off.
            */
           port = netisr_hashport(m->m_pkthdr.hash);
           pmsg = &m->m_hdr.mh_netmsg;
           netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport,
                       0, ni->ni_handler);
           pmsg->nm_packet = m;
           pmsg->base.lmsg.u.ms_result = num;
           lwkt_sendmsg(port, &pmsg->base.lmsg);
   
           return (0);
   }
   
   /*
    * Run a netisr service function on the packet.
    *
    * The packet must have been correctly characterized!
    */
   int
   netisr_handle(int num, struct mbuf *m)
   {
           struct netisr *ni;
           struct netmsg_packet *pmsg;
           lwkt_port_t port;
   
           /*
            * Get the protocol port based on the packet hash
            */
           KASSERT((m->m_flags & M_HASH), ("packet not characterized"));
           port = netisr_hashport(m->m_pkthdr.hash);
           KASSERT(&curthread->td_msgport == port, ("wrong msgport"));
   
           KASSERT((num > 0 && num <= NELEM(netisrs)), ("bad isr %d", num));
           ni = &netisrs[num];
           if (ni->ni_handler == NULL) {
                   kprintf("unregistered isr %d\n", num);
                   m_freem(m);
                   return EIO;
           }
   
           /*
            * Initialize the netmsg, and run the handler directly.
            */
           pmsg = &m->m_hdr.mh_netmsg;
           netmsg_init(&pmsg->base, NULL, &netisr_apanic_rport,
                       0, ni->ni_handler);
           pmsg->nm_packet = m;
           pmsg->base.lmsg.u.ms_result = num;
           ni->ni_handler((netmsg_t)&pmsg->base);
   
           return 0;
   }
   
   /*
    * Pre-characterization of a deeper portion of the packet for the
    * requested isr.
    *
    * The base of the ISR type (e.g. IP) that we want to characterize is
    * at (hoff) relative to the beginning of the mbuf.  This allows
    * e.g. ether_characterize() to not have to adjust the m_data/m_len.
    */
   void
   netisr_characterize(int num, struct mbuf **mp, int hoff)
   {
           struct netisr *ni;
           struct mbuf *m;
   
           /*
            * Validation
            */
           m = *mp;
           KKASSERT(m != NULL);
   
           if (num < 0 || num >= NETISR_MAX) {
                   if (num == NETISR_MAX) {
                           m->m_flags |= M_HASH;
                           m->m_pkthdr.hash = 0;
                           return;
                   }
                   panic("Bad isr %d", num);
           }
   
           /*
            * Valid netisr?
            */
           ni = &netisrs[num];
           if (ni->ni_handler == NULL) {
                   kprintf("Unregistered isr %d\n", num);
                   m_freem(m);
                   *mp = NULL;
           }
   
           /*
            * Characterize the packet
            */
           if ((m->m_flags & M_HASH) == 0) {
                   ni->ni_hashfn(mp, hoff);
                   m = *mp;
                   if (m && (m->m_flags & M_HASH) == 0)
                           kprintf("netisr_queue(%d): packet hash failed\n", num);
           }
   }
   
   void
   netisr_register(int num, netisr_fn_t handler, netisr_hashfn_t hashfn)
   {
           struct netisr *ni;
   
           KASSERT((num > 0 && num <= NELEM(netisrs)),
                   ("netisr_register: bad isr %d", num));
           KKASSERT(handler != NULL);
   
           if (hashfn == NULL)
                   hashfn = netisr_hashfn0;
   
           ni = &netisrs[num];
   
           ni->ni_handler = handler;
           ni->ni_hashck = netisr_nohashck;
           ni->ni_hashfn = hashfn;
           netmsg_init(&ni->ni_netmsg, NULL, &netisr_adone_rport, 0, NULL);
   }
   
   void
   netisr_register_hashcheck(int num, netisr_hashck_t hashck)
   {
           struct netisr *ni;
   
           KASSERT((num > 0 && num <= NELEM(netisrs)),
                   ("netisr_register: bad isr %d", num));
   
           ni = &netisrs[num];
           ni->ni_hashck = hashck;
   }
   
   void
   netisr_register_rollup(netisr_ru_t ru_func, int prio)
   {
           struct netmsg_rollup *new_ru, *ru;
   
           new_ru = kmalloc(sizeof(*new_ru), M_TEMP, M_WAITOK|M_ZERO);
           new_ru->ru_func = ru_func;
           new_ru->ru_prio = prio;
   
           /*
            * Higher priority "rollup" appears first
            */
           TAILQ_FOREACH(ru, &netrulist, ru_entry) {
                   if (ru->ru_prio < new_ru->ru_prio) {
                           TAILQ_INSERT_BEFORE(ru, new_ru, ru_entry);
                           return;
                   }
           }
           TAILQ_INSERT_TAIL(&netrulist, new_ru, ru_entry);
   }
   
   /*
    * Return a default protocol control message processing thread port
    */
   lwkt_port_t
   cpu0_ctlport(int cmd __unused, struct sockaddr *sa __unused,
                void *extra __unused)
   {
           return (&netisr_cpu[0].td_msgport);
   }
   
   /*
    * This is a default netisr packet characterization function which
    * sets M_HASH.  If a netisr is registered with a NULL hashfn function
    * this one is assigned.
    *
    * This function makes no attempt to validate the packet.
    */
   static void
   netisr_hashfn0(struct mbuf **mp, int hoff __unused)
   {
           struct mbuf *m = *mp;
   
           m->m_flags |= M_HASH;
           m->m_pkthdr.hash = 0;
   }
   
   /*
    * schednetisr() is used to call the netisr handler from the appropriate
    * netisr thread for polling and other purposes.
    *
    * This function may be called from a hard interrupt or IPI and must be
    * MP SAFE and non-blocking.  We use a fixed per-cpu message instead of
    * trying to allocate one.  We must get ourselves onto the target cpu
    * to safely check the MSGF_DONE bit on the message but since the message
    * will be sent to that cpu anyway this does not add any extra work beyond
    * what lwkt_sendmsg() would have already had to do to schedule the target
    * thread.
    */
   static void
   schednetisr_remote(void *data)
   {
           int num = (int)(intptr_t)data;
           struct netisr *ni = &netisrs[num];
           lwkt_port_t port = &netisr_cpu[0].td_msgport;
           netmsg_base_t pmsg;
   
           pmsg = &netisrs[num].ni_netmsg;
           if (pmsg->lmsg.ms_flags & MSGF_DONE) {
                   netmsg_init(pmsg, NULL, &netisr_adone_rport, 0, ni->ni_handler);
                   pmsg->lmsg.u.ms_result = num;
                   lwkt_sendmsg(port, &pmsg->lmsg);
           }
   }
   
   void
   schednetisr(int num)
   {
           KASSERT((num > 0 && num <= NELEM(netisrs)),
                   ("schednetisr: bad isr %d", num));
           KKASSERT(netisrs[num].ni_handler != NULL);
           if (mycpu->gd_cpuid != 0) {
                   lwkt_send_ipiq(globaldata_find(0),
                                  schednetisr_remote, (void *)(intptr_t)num);
           } else {
                   crit_enter();
                   schednetisr_remote((void *)(intptr_t)num);
                   crit_exit();
           }
   }
   
   static void
   netisr_barrier_dispatch(netmsg_t nmsg)
   {
           struct netmsg_barrier *msg = (struct netmsg_barrier *)nmsg;
   
           atomic_clear_cpumask(msg->br_cpumask, mycpu->gd_cpumask);
           if (*msg->br_cpumask == 0)
                   wakeup(msg->br_cpumask);
   
           for (;;) {
                   uint32_t done = msg->br_done;
   
                   cpu_ccfence();
                   if ((done & NETISR_BR_NOTDONE) == 0)
                           break;
   
                   tsleep_interlock(&msg->br_done, 0);
                   if (atomic_cmpset_int(&msg->br_done,
                       done, done | NETISR_BR_WAITDONE))
                           tsleep(&msg->br_done, PINTERLOCKED, "nbrdsp", 0);
           }
   
           lwkt_replymsg(&nmsg->lmsg, 0);
   }
   
   struct netisr_barrier *
   netisr_barrier_create(void)
   {
           struct netisr_barrier *br;
   
           br = kmalloc(sizeof(*br), M_LWKTMSG, M_WAITOK | M_ZERO);
           return br;
   }
   
   void
   netisr_barrier_set(struct netisr_barrier *br)
   {
           volatile cpumask_t other_cpumask;
           int i, cur_cpuid;
   
           KKASSERT(&curthread->td_msgport == netisr_cpuport(0));
           KKASSERT(!br->br_isset);
   
           other_cpumask = mycpu->gd_other_cpus & smp_active_mask;
           cur_cpuid = mycpuid;
   
           for (i = 0; i < ncpus; ++i) {
                   struct netmsg_barrier *msg;
   
                   if (i == cur_cpuid)
                           continue;
   
                   msg = kmalloc(sizeof(struct netmsg_barrier),
                                 M_LWKTMSG, M_WAITOK);
                   netmsg_init(&msg->base, NULL, &netisr_afree_rport,
                               MSGF_PRIORITY, netisr_barrier_dispatch);
                   msg->br_cpumask = &other_cpumask;
                   msg->br_done = NETISR_BR_NOTDONE;
   
                   KKASSERT(br->br_msgs[i] == NULL);
                   br->br_msgs[i] = msg;
           }
   
           for (i = 0; i < ncpus; ++i) {
                   if (i == cur_cpuid)
                           continue;
                   lwkt_sendmsg(netisr_cpuport(i), &br->br_msgs[i]->base.lmsg);
           }
   
           while (other_cpumask != 0) {
                   tsleep_interlock(&other_cpumask, 0);
                   if (other_cpumask != 0)
                           tsleep(&other_cpumask, PINTERLOCKED, "nbrset", 0);
           }
           br->br_isset = 1;
   }
   
   void
   netisr_barrier_rem(struct netisr_barrier *br)
   {
           int i, cur_cpuid;
   
           KKASSERT(&curthread->td_msgport == netisr_cpuport(0));
           KKASSERT(br->br_isset);
   
           cur_cpuid = mycpuid;
           for (i = 0; i < ncpus; ++i) {
                   struct netmsg_barrier *msg = br->br_msgs[i];
                   uint32_t done;
   
                   msg = br->br_msgs[i];
                   br->br_msgs[i] = NULL;
   
                   if (i == cur_cpuid)
                           continue;
   
                   done = atomic_swap_int(&msg->br_done, 0);
                   if (done & NETISR_BR_WAITDONE)
                           wakeup(&msg->br_done);
           }
           br->br_isset = 0;
   }
   
   static void
   netisr_nohashck(struct mbuf *m, const struct pktinfo *pi __unused)
   {
           m->m_flags &= ~M_HASH;
   }
   
   void
   netisr_hashcheck(int num, struct mbuf *m, const struct pktinfo *pi)
   {
           struct netisr *ni;
   
           if (num < 0 || num >= NETISR_MAX)
                   panic("Bad isr %d", num);
   
           /*
            * Valid netisr?
            */
           ni = &netisrs[num];
           if (ni->ni_handler == NULL)
                   panic("Unregistered isr %d", num);
   
           ni->ni_hashck(m, pi);
   }

Cache object: 97c4abe2a13f843a9cda967b13167c44