1 /* $NetBSD: if_gif.h,v 1.35 2020/02/01 02:57:45 riastradh Exp $ */ 2 /* $KAME: if_gif.h,v 1.23 2001/07/27 09:21:42 itojun Exp $ */ 3 4 /* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * if_gif.h 35 */ 36 37 #ifndef _NET_IF_GIF_H_ 38 #define _NET_IF_GIF_H_ 39 40 #include <sys/queue.h> 41 #include <sys/percpu.h> 42 #ifdef _KERNEL 43 #include <sys/pserialize.h> 44 #include <sys/psref.h> 45 #endif 46 47 #ifdef _KERNEL_OPT 48 #include "opt_inet.h" 49 #endif 50 51 #include <netinet/in.h> 52 /* xxx sigh, why route have struct route instead of pointer? */ 53 54 extern struct psref_class *gv_psref_class; 55 56 struct encaptab; 57 58 struct gif_variant { 59 struct gif_softc *gv_softc; 60 struct sockaddr *gv_psrc; /* Physical src addr */ 61 struct sockaddr *gv_pdst; /* Physical dst addr */ 62 const struct encaptab *gv_encap_cookie4; 63 const struct encaptab *gv_encap_cookie6; 64 int (*gv_output)(struct gif_variant *, int, struct mbuf *); 65 66 struct psref_target gv_psref; 67 }; 68 69 struct gif_softc { 70 struct ifnet gif_if; /* common area - must be at the top */ 71 percpu_t *gif_ro_percpu; /* struct tunnel_ro */ 72 struct gif_variant *gif_var; /* 73 * reader must use gif_getref_variant() 74 * instead of direct dereference. 75 */ 76 kmutex_t gif_lock; /* writer lock for gif_var */ 77 pserialize_t gif_psz; 78 79 int gif_pmtu; 80 81 LIST_ENTRY(gif_softc) gif_list; /* list of all gifs */ 82 }; 83 #define GIF_ROUTE_TTL 10 84 85 #define GIF_MTU (1280) /* Default MTU */ 86 #define GIF_MTU_MIN (1280) /* Minimum MTU */ 87 #define GIF_MTU_MAX (8192) /* Maximum MTU */ 88 89 /* 90 * Get gif_variant from gif_softc. 91 * 92 * Never return NULL by contract. 93 * gif_variant itself is protected not to be freed by gv_psref. 94 * Once a reader dereference sc->sc_var by this API, the reader must not 95 * re-dereference form sc->sc_var. 96 */ 97 static __inline struct gif_variant * 98 gif_getref_variant(struct gif_softc *sc, struct psref *psref) 99 { 100 struct gif_variant *var; 101 int s; 102 103 s = pserialize_read_enter(); 104 var = atomic_load_consume(&sc->gif_var); 105 KASSERT(var != NULL); 106 psref_acquire(psref, &var->gv_psref, gv_psref_class); 107 pserialize_read_exit(s); 108 109 return var; 110 } 111 112 static __inline void 113 gif_putref_variant(struct gif_variant *var, struct psref *psref) 114 { 115 116 KASSERT(var != NULL); 117 psref_release(psref, &var->gv_psref, gv_psref_class); 118 } 119 120 static __inline bool 121 gif_heldref_variant(struct gif_variant *var) 122 { 123 124 return psref_held(&var->gv_psref, gv_psref_class); 125 } 126 127 /* Prototypes */ 128 void gif_input(struct mbuf *, int, struct ifnet *); 129 130 #ifdef GIF_ENCAPCHECK 131 int gif_encapcheck(struct mbuf *, int, int, void *); 132 #endif 133 134 /* 135 * Locking notes: 136 * + gif_softc_list is protected by gif_softcs.lock (an adaptive mutex) 137 * gif_softc_list is list of all gif_softcs. It is used by ioctl 138 * context only. 139 * + gif_softc->gif_var is protected by 140 * - gif_softc->gif_lock (an adaptive mutex) for writer 141 * - gif_var->gv_psref for reader 142 * gif_softc->gif_var is used for variant values while the gif tunnel 143 * exists. 144 * + Each CPU's tunnel_ro.tr_ro of gif_ro_percpu are protected by 145 * percpu'ed tunnel_ro.tr_lock. 146 * 147 * Locking order: 148 * - encap_lock => gif_softc->gif_lock => gif_softcs.lock 149 */ 150 #endif /* !_NET_IF_GIF_H_ */ 151