FreeBSD/Linux Kernel Cross Reference
sys/net/if_gif.h

     /*      $NetBSD: if_gif.h,v 1.35 2020/02/01 02:57:45 riastradh Exp $    */
     /*      $KAME: if_gif.h,v 1.23 2001/07/27 09:21:42 itojun Exp $ */
     
     /*
      * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 3. Neither the name of the project nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     */
    
    /*
     * if_gif.h
     */
    
    #ifndef _NET_IF_GIF_H_
    #define _NET_IF_GIF_H_
    
    #include <sys/queue.h>
    #include <sys/percpu.h>
    #ifdef _KERNEL
    #include <sys/pserialize.h>
    #include <sys/psref.h>
    #endif
    
    #ifdef _KERNEL_OPT
    #include "opt_inet.h"
    #endif
    
    #include <netinet/in.h>
    /* xxx sigh, why route have struct route instead of pointer? */
    
    extern struct psref_class *gv_psref_class;
    
    struct encaptab;
    
    struct gif_variant {
            struct gif_softc *gv_softc;
            struct sockaddr *gv_psrc; /* Physical src addr */
            struct sockaddr *gv_pdst; /* Physical dst addr */
            const struct encaptab *gv_encap_cookie4;
            const struct encaptab *gv_encap_cookie6;
            int (*gv_output)(struct gif_variant *, int, struct mbuf *);
    
            struct psref_target gv_psref;
    };
    
    struct gif_softc {
            struct ifnet    gif_if;         /* common area - must be at the top */
            percpu_t *gif_ro_percpu;        /* struct tunnel_ro */
            struct gif_variant *gif_var;    /*
                                             * reader must use gif_getref_variant()
                                             * instead of direct dereference.
                                             */
            kmutex_t gif_lock;              /* writer lock for gif_var */
            pserialize_t gif_psz;
    
            int gif_pmtu;
    
            LIST_ENTRY(gif_softc) gif_list; /* list of all gifs */
    };
    #define GIF_ROUTE_TTL   10
    
    #define GIF_MTU         (1280)  /* Default MTU */
    #define GIF_MTU_MIN     (1280)  /* Minimum MTU */
    #define GIF_MTU_MAX     (8192)  /* Maximum MTU */
    
    /*
     * Get gif_variant from gif_softc.
     *
     * Never return NULL by contract.
     * gif_variant itself is protected not to be freed by gv_psref.
     * Once a reader dereference sc->sc_var by this API, the reader must not
     * re-dereference form sc->sc_var.
     */
    static __inline struct gif_variant *
    gif_getref_variant(struct gif_softc *sc, struct psref *psref)
    {
           struct gif_variant *var;
           int s;
   
           s = pserialize_read_enter();
           var = atomic_load_consume(&sc->gif_var);
           KASSERT(var != NULL);
           psref_acquire(psref, &var->gv_psref, gv_psref_class);
           pserialize_read_exit(s);
   
           return var;
   }
   
   static __inline void
   gif_putref_variant(struct gif_variant *var, struct psref *psref)
   {
   
           KASSERT(var != NULL);
           psref_release(psref, &var->gv_psref, gv_psref_class);
   }
   
   static __inline bool
   gif_heldref_variant(struct gif_variant *var)
   {
   
           return psref_held(&var->gv_psref, gv_psref_class);
   }
   
   /* Prototypes */
   void    gif_input(struct mbuf *, int, struct ifnet *);
   
   #ifdef GIF_ENCAPCHECK
   int     gif_encapcheck(struct mbuf *, int, int, void *);
   #endif
   
   /*
    * Locking notes:
    * + gif_softc_list is protected by gif_softcs.lock (an adaptive mutex)
    *       gif_softc_list is list of all gif_softcs. It is used by ioctl
    *       context only.
    * + gif_softc->gif_var is protected by
    *   - gif_softc->gif_lock (an adaptive mutex) for writer
    *   - gif_var->gv_psref for reader
    *       gif_softc->gif_var is used for variant values while the gif tunnel
    *       exists.
    * + Each CPU's tunnel_ro.tr_ro of gif_ro_percpu are protected by
    *   percpu'ed tunnel_ro.tr_lock.
    *
    * Locking order:
    *     - encap_lock => gif_softc->gif_lock => gif_softcs.lock
    */
   #endif /* !_NET_IF_GIF_H_ */

Cache object: 9023a0ecaa6affec3e5197ea10e419f1