1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2005 Paolo Pisati <piso@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 */ 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #ifdef _KERNEL 33 #include <sys/libkern.h> 34 #include <sys/param.h> 35 #include <sys/lock.h> 36 #include <sys/rwlock.h> 37 #else 38 #include <stdio.h> 39 #include <string.h> 40 #include <sys/types.h> 41 #include <errno.h> 42 #endif 43 44 #include <netinet/in_systm.h> 45 #include <netinet/in.h> 46 #include <netinet/ip.h> 47 48 #ifdef _KERNEL 49 #include <netinet/libalias/alias_local.h> 50 #include <netinet/libalias/alias_mod.h> 51 #else 52 #include "alias_local.h" 53 #include "alias_mod.h" 54 #endif 55 56 /* Protocol and userland module handlers chains. */ 57 static TAILQ_HEAD(handler_chain, proto_handler) handler_chain = 58 TAILQ_HEAD_INITIALIZER(handler_chain); 59 60 static int 61 attach_handler(struct proto_handler *p) 62 { 63 struct proto_handler *b; 64 65 TAILQ_FOREACH(b, &handler_chain, link) { 66 if ((b->pri == p->pri) && 67 (b->dir == p->dir) && 68 (b->proto == p->proto)) 69 return (EEXIST); 70 if (b->pri > p->pri) { 71 TAILQ_INSERT_BEFORE(b, p, link); 72 return (0); 73 } 74 } 75 76 TAILQ_INSERT_TAIL(&handler_chain, p, link); 77 78 return (0); 79 } 80 81 int 82 LibAliasAttachHandlers(struct proto_handler *p) 83 { 84 int error; 85 86 while (p->dir != NODIR) { 87 error = attach_handler(p); 88 if (error) 89 return (error); 90 p++; 91 } 92 93 return (0); 94 } 95 96 /* XXXGL: should be void, but no good reason to break ABI */ 97 int 98 LibAliasDetachHandlers(struct proto_handler *p) 99 { 100 while (p->dir != NODIR) { 101 TAILQ_REMOVE(&handler_chain, p, link); 102 p++; 103 } 104 105 return (0); 106 } 107 108 int 109 find_handler(int8_t dir, int8_t proto, struct libalias *la, struct ip *ip, 110 struct alias_data *ad) 111 { 112 struct proto_handler *p; 113 114 TAILQ_FOREACH(p, &handler_chain, link) 115 if ((p->dir & dir) && (p->proto & proto) && 116 p->fingerprint(la, ad) == 0) 117 return (p->protohandler(la, ip, ad)); 118 119 return (ENOENT); 120 } 121 122 struct proto_handler * 123 first_handler(void) 124 { 125 return (TAILQ_FIRST(&handler_chain)); 126 } 127 128 #ifndef _KERNEL 129 /* Dll manipulation code - this code is not thread safe... */ 130 static SLIST_HEAD(dll_chain, dll) dll_chain = SLIST_HEAD_INITIALIZER(dll_chain); 131 int 132 attach_dll(struct dll *p) 133 { 134 struct dll *b; 135 136 SLIST_FOREACH(b, &dll_chain, next) { 137 if (!strncmp(b->name, p->name, DLL_LEN)) 138 return (EEXIST); /* Dll name conflict. */ 139 } 140 SLIST_INSERT_HEAD(&dll_chain, p, next); 141 return (0); 142 } 143 144 void * 145 detach_dll(char *p) 146 { 147 struct dll *b, *b_tmp; 148 void *error; 149 150 b = NULL; 151 error = NULL; 152 SLIST_FOREACH_SAFE(b, &dll_chain, next, b_tmp) 153 if (!strncmp(b->name, p, DLL_LEN)) { 154 SLIST_REMOVE(&dll_chain, b, dll, next); 155 error = b; 156 break; 157 } 158 return (error); 159 } 160 161 struct dll * 162 walk_dll_chain(void) 163 { 164 struct dll *t; 165 166 t = SLIST_FIRST(&dll_chain); 167 if (t == NULL) 168 return (NULL); 169 SLIST_REMOVE_HEAD(&dll_chain, next); 170 return (t); 171 } 172 #endif /* !_KERNEL */ 173