1 /* $NetBSD: npf_alg.c,v 1.2 2010/11/11 06:30:39 rmind Exp $ */ 2 3 /*- 4 * Copyright (c) 2010 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This material is based upon work partially supported by The 8 * NetBSD Foundation under a contract with Mindaugas Rasiukevicius. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * NPF interface for application level gateways (ALGs). 34 * 35 * XXX: locking 36 */ 37 38 #include <sys/cdefs.h> 39 __KERNEL_RCSID(0, "$NetBSD: npf_alg.c,v 1.2 2010/11/11 06:30:39 rmind Exp $"); 40 41 #include <sys/param.h> 42 #include <sys/kernel.h> 43 #include <sys/kmem.h> 44 #include <sys/pool.h> 45 #include <net/pfil.h> 46 47 #include "npf_impl.h" 48 49 /* NAT ALG structure for registration. */ 50 struct npf_alg { 51 LIST_ENTRY(npf_alg) na_entry; 52 npf_alg_t * na_bptr; 53 npf_algfunc_t na_match_func; 54 npf_algfunc_t na_out_func; 55 npf_algfunc_t na_in_func; 56 npf_algfunc_t na_seid_func; 57 }; 58 59 static LIST_HEAD(, npf_alg) nat_alg_list __read_mostly; 60 61 void 62 npf_alg_sysinit(void) 63 { 64 65 LIST_INIT(&nat_alg_list); 66 } 67 68 void 69 npf_alg_sysfini(void) 70 { 71 72 KASSERT(LIST_EMPTY(&nat_alg_list)); 73 } 74 75 /* 76 * npf_alg_register: register application-level gateway. 77 * 78 * XXX: Protected by module lock, but unify serialisation later. 79 */ 80 npf_alg_t * 81 npf_alg_register(npf_algfunc_t match, npf_algfunc_t out, npf_algfunc_t in, 82 npf_algfunc_t seid) 83 { 84 npf_alg_t *alg; 85 86 alg = kmem_alloc(sizeof(npf_alg_t), KM_SLEEP); 87 alg->na_bptr = alg; 88 alg->na_match_func = match; 89 alg->na_out_func = out; 90 alg->na_in_func = in; 91 alg->na_seid_func = seid; 92 LIST_INSERT_HEAD(&nat_alg_list, alg, na_entry); 93 return alg; 94 } 95 96 /* 97 * npf_alg_unregister: unregister application-level gateway. 98 */ 99 int 100 npf_alg_unregister(npf_alg_t *alg) 101 { 102 npf_alg_t *it; 103 104 LIST_FOREACH(it, &nat_alg_list, na_entry) { 105 if (alg == it) 106 break; 107 } 108 if (it != NULL) { 109 LIST_REMOVE(alg, na_entry); 110 } 111 /* TODO: Flush relevant sessions. */ 112 kmem_free(alg, sizeof(npf_alg_t)); 113 return 0; 114 } 115 116 /* 117 * npf_alg_match: call ALG matching inspectors, determine if any ALG matches. 118 */ 119 bool 120 npf_alg_match(npf_cache_t *npc, nbuf_t *nbuf, npf_nat_t *nt) 121 { 122 npf_alg_t *alg; 123 npf_algfunc_t func; 124 125 LIST_FOREACH(alg, &nat_alg_list, na_entry) { 126 func = alg->na_match_func; 127 if (func && func(npc, nbuf, nt)) { 128 return true; 129 } 130 } 131 return false; 132 } 133 134 /* 135 * npf_alg_exec: execute ALG hooks for translation. 136 */ 137 void 138 npf_alg_exec(npf_cache_t *npc, nbuf_t *nbuf, npf_nat_t *nt, const int di) 139 { 140 npf_alg_t *alg; 141 142 LIST_FOREACH(alg, &nat_alg_list, na_entry) { 143 if ((di & PFIL_OUT) != 0 && alg->na_out_func != NULL) { 144 (alg->na_out_func)(npc, nbuf, nt); 145 continue; 146 } 147 if ((di & PFIL_IN) != 0 && alg->na_in_func != NULL) { 148 (alg->na_in_func)(npc, nbuf, nt); 149 continue; 150 } 151 } 152 } 153 154 bool 155 npf_alg_sessionid(npf_cache_t *npc, nbuf_t *nbuf, npf_cache_t *key) 156 { 157 npf_alg_t *alg; 158 npf_algfunc_t func; 159 160 LIST_FOREACH(alg, &nat_alg_list, na_entry) { 161 func = alg->na_seid_func; 162 if (func && func(npc, nbuf, (npf_nat_t *)key)) { 163 return true; 164 } 165 } 166 return false; 167 } 168