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 * $FreeBSD$ 27 */ 28 29 /* 30 * Alias_mod.h defines the outside world interfaces for the packet aliasing 31 * modular framework 32 */ 33 34 #ifndef _ALIAS_MOD_H_ 35 #define _ALIAS_MOD_H_ 36 37 #ifdef _KERNEL 38 MALLOC_DECLARE(M_ALIAS); 39 40 /* Use kernel allocator. */ 41 #if defined(_SYS_MALLOC_H_) 42 #define malloc(x) malloc(x, M_ALIAS, M_NOWAIT|M_ZERO) 43 #define calloc(x, n) malloc(x*n) 44 #define free(x) free(x, M_ALIAS) 45 #endif 46 #endif 47 48 /* Protocol handlers struct & function. */ 49 50 /* Packet flow direction. */ 51 #define IN 1 52 #define OUT 2 53 54 /* Working protocol. */ 55 #define IP 1 56 #define TCP 2 57 #define UDP 4 58 59 /* 60 * Data passed to protocol handler module, it must be filled 61 * right before calling find_handler() to determine which 62 * module is elegible to be called. 63 */ 64 65 struct alias_data { 66 struct alias_link *lnk; 67 struct in_addr *oaddr; /* Original address. */ 68 struct in_addr *aaddr; /* Alias address. */ 69 uint16_t *aport; /* Alias port. */ 70 uint16_t *sport, *dport; /* Source & destination port */ 71 uint16_t maxpktsize; /* Max packet size. */ 72 }; 73 74 /* 75 * This structure contains all the information necessary to make 76 * a protocol handler correctly work. 77 */ 78 79 struct proto_handler { 80 u_int pri; /* Handler priority. */ 81 int16_t dir; /* Flow direction. */ 82 uint8_t proto; /* Working protocol. */ 83 int (*fingerprint)(struct libalias *la, /* Fingerprint * function. */ 84 struct ip *pip, struct alias_data *ah); 85 int (*protohandler)(struct libalias *la, /* Aliasing * function. */ 86 struct ip *pip, struct alias_data *ah); 87 LIST_ENTRY(proto_handler) entries; 88 }; 89 90 91 /* 92 * Used only in userland when libalias needs to keep track of all 93 * module loaded. In kernel land (kld mode) we don't need to care 94 * care about libalias modules cause it's kld to do it for us. 95 */ 96 97 #define DLL_LEN 32 98 struct dll { 99 char name[DLL_LEN]; /* Name of module. */ 100 void *handle; /* 101 * Ptr to shared obj obtained through 102 * dlopen() - use this ptr to get access 103 * to any symbols from a loaded module 104 * via dlsym(). 105 */ 106 SLIST_ENTRY(dll) next; 107 }; 108 109 /* Functions used with protocol handlers. */ 110 111 void handler_chain_init(void); 112 void handler_chain_destroy(void); 113 int LibAliasAttachHandlers(struct proto_handler *); 114 int LibAliasDetachHandlers(struct proto_handler *); 115 int detach_handler(struct proto_handler *); 116 int find_handler(int8_t, int8_t, struct libalias *, 117 struct ip *, struct alias_data *); 118 struct proto_handler *first_handler(void); 119 120 /* Functions used with dll module. */ 121 122 void dll_chain_init(void); 123 void dll_chain_destroy(void); 124 int attach_dll(struct dll *); 125 void *detach_dll(char *); 126 struct dll *walk_dll_chain(void); 127 128 /* End of handlers. */ 129 #define EOH -1 130 131 /* 132 * Some defines borrowed from sys/module.h used to compile a kld 133 * in userland as a shared lib. 134 */ 135 136 #ifndef _KERNEL 137 typedef enum modeventtype { 138 MOD_LOAD, 139 MOD_UNLOAD, 140 MOD_SHUTDOWN, 141 MOD_QUIESCE 142 } modeventtype_t; 143 144 typedef struct module *module_t; 145 typedef int (*modeventhand_t)(module_t, int /* modeventtype_t */, void *); 146 147 /* 148 * Struct for registering modules statically via SYSINIT. 149 */ 150 typedef struct moduledata { 151 const char *name; /* module name */ 152 modeventhand_t evhand; /* event handler */ 153 void *priv; /* extra data */ 154 } moduledata_t; 155 #endif 156 157 #endif /* !_ALIAS_MOD_H_ */ 158