sys/net/libalias/alias_mod.c

   1 /*-
   2  * Copyright (c) 2005 Paolo Pisati <piso@FreeBSD.org>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *      notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *      notice, this list of conditions and the following disclaimer in the
  12  *      documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  24  * SUCH DAMAGE.
  25  *
  26  */
  27 #include <sys/cdefs.h>
  28 __FBSDID("$FreeBSD: src/sys/netinet/libalias/alias_mod.c,v 1.3.6.1 2008/11/25 02:59:29 kensmith Exp $");
  29
  30 #ifdef _KERNEL
  31 #include <sys/libkern.h>
  32 #include <sys/param.h>
  33 #include <sys/lock.h>
  34 #include <sys/idr.h>
  35 #include <sys/queue.h>
  36 #else
  37 #include <stdio.h>
  38 #include <string.h>
  39 #include <sys/types.h>
  40 #include <errno.h>
  41 #endif
  42
  43 #include <netinet/in_systm.h>
  44 #include <netinet/in.h>
  45 #include <netinet/ip.h>
  46
  47
  48 #include "alias_local.h"
  49 #include "alias_mod.h"
  50
  51 /* Protocol and userland module handlers chains. */
  52 LIST_HEAD(handler_chain, proto_handler) handler_chain = LIST_HEAD_INITIALIZER(foo);
  53
  54 SLIST_HEAD(dll_chain, dll) dll_chain = SLIST_HEAD_INITIALIZER(foo);
  55
  56
  57 #define LIBALIAS_RWLOCK_INIT() ;
  58 #define LIBALIAS_RWLOCK_DESTROY()       ;
  59 #define LIBALIAS_WLOCK_ASSERT() ;
  60 #define LIBALIAS_RLOCK() ;
  61 #define LIBALIAS_RUNLOCK() ;
  62 #define LIBALIAS_WLOCK() ;
  63 #define LIBALIAS_WUNLOCK() ;
  64 #define _handler_chain_init() ;
  65 #define _handler_chain_destroy() ;
  66
  67 void
  68 handler_chain_init(void)
  69 {
  70         _handler_chain_init();
  71 }
  72
  73 void
  74 handler_chain_destroy(void)
  75 {
  76         _handler_chain_destroy();
  77 }
  78
  79 static int
  80 _attach_handler(struct proto_handler *p)
  81 {
  82         struct proto_handler *b = NULL;
  83
  84         LIBALIAS_WLOCK_ASSERT();
  85         LIST_FOREACH(b, &handler_chain, entries) {
  86                 if ((b->pri == p->pri) &&
  87                         (b->dir == p->dir) &&
  88                         (b->proto == p->proto))
  89                         return (EEXIST); /* Priority conflict. */
  90                 if (b->pri > p->pri) {
  91                         LIST_INSERT_BEFORE(b, p, entries);
  92                         return (0);
  93                 }
  94         }
  95         /* End of list or found right position, inserts here. */
  96         if (b)
  97                 LIST_INSERT_AFTER(b, p, entries);
  98         else
  99                 LIST_INSERT_HEAD(&handler_chain, p, entries);
 100         return (0);
 101 }
 102
 103 static int
 104 _detach_handler(struct proto_handler *p)
 105 {
 106         struct proto_handler *b, *b_tmp;;
 107
 108         LIBALIAS_WLOCK_ASSERT();
 109
 110         LIST_FOREACH_MUTABLE(b, &handler_chain, entries, b_tmp) {
 111                 if (b == p) {
 112                         LIST_REMOVE(b, entries);
 113                         return (0);
 114                 }
 115         }
 116
 117
 118         return (ENOENT); /* Handler not found. */
 119 }
 120
 121 int
 122 LibAliasAttachHandlers(struct proto_handler *_p)
 123 {
 124         int i, error = -1;
 125
 126         LIBALIAS_WLOCK();
 127         for (i=0; 1; i++) {
 128                 if (*((int *)&_p[i]) == EOH)
 129                         break;
 130                 error = _attach_handler(&_p[i]);
 131                 if (error != 0)
 132                         break;
 133         }
 134         LIBALIAS_WUNLOCK();
 135         return (error);
 136 }
 137
 138 int
 139 LibAliasDetachHandlers(struct proto_handler *_p)
 140 {
 141         int i, error = -1;
 142
 143         LIBALIAS_WLOCK();
 144         for (i=0; 1; i++) {
 145                 if (*((int *)&_p[i]) == EOH)
 146                         break;
 147                 error = _detach_handler(&_p[i]);
 148                 if (error != 0)
 149                         break;
 150         }
 151         LIBALIAS_WUNLOCK();
 152         return (error);
 153 }
 154
 155 int
 156 detach_handler(struct proto_handler *_p)
 157 {
 158         int error = -1;
 159
 160         LIBALIAS_WLOCK();
 161         error = _detach_handler(_p);
 162         LIBALIAS_WUNLOCK();
 163         return (error);
 164 }
 165
 166 int
 167 find_handler(int8_t dir, int8_t proto, struct libalias *la, struct ip *pip,
 168                  struct alias_data *ad)
 169 {
 170         struct proto_handler *p;
 171         int error = ENOENT;
 172
 173         LIBALIAS_RLOCK();
 174
 175         LIST_FOREACH(p, &handler_chain, entries) {
 176                 if ((p->dir & dir) && (p->proto & proto))
 177                         if (p->fingerprint(la, pip, ad) == 0) {
 178                                 error = p->protohandler(la, pip, ad);
 179                                 break;
 180                         }
 181         }
 182         LIBALIAS_RUNLOCK();
 183         return (error);
 184 }
 185
 186 struct proto_handler *
 187 first_handler(void)
 188 {
 189
 190         return (LIST_FIRST(&handler_chain));
 191 }
 192
 193 /* Dll manipulation code - this code is not thread safe... */
 194
 195
 196
 197 struct dll *
 198 walk_dll_chain(void)
 199 {
 200         struct dll *t;
 201
 202         t = SLIST_FIRST(&dll_chain);
 203         if (t == NULL)
 204                 return (NULL);
 205         SLIST_REMOVE_HEAD(&dll_chain, next);
 206         return (t);
 207 }