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
54extern struct psref_class *gv_psref_class;
55
56struct encaptab;
57
58struct 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
69struct 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 */
97static __inline struct gif_variant *
98gif_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
112static __inline void
113gif_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
120static __inline bool
121gif_heldref_variant(struct gif_variant *var)
122{
123
124 return psref_held(&var->gv_psref, gv_psref_class);
125}
126
127/* Prototypes */
128void gif_input(struct mbuf *, int, struct ifnet *);
129
130#ifdef GIF_ENCAPCHECK
131int 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_ */