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 /* Packet flow direction flags. */ 49 #define IN 0x0001 50 #define OUT 0x0002 51 #define NODIR 0x4000 52 53 /* Working protocol flags. */ 54 #define IP 0x01 55 #define TCP 0x02 56 #define UDP 0x04 57 58 /* 59 * Data passed to protocol handler module, it must be filled 60 * right before calling find_handler() to determine which 61 * module is elegible to be called. 62 */ 63 struct alias_data { 64 struct alias_link *lnk; 65 struct in_addr *oaddr; /* Original address. */ 66 struct in_addr *aaddr; /* Alias address. */ 67 uint16_t *aport; /* Alias port. */ 68 uint16_t *sport, *dport; /* Source & destination port */ 69 uint16_t maxpktsize; /* Max packet size. */ 70 }; 71 72 /* 73 * This structure contains all the information necessary to make 74 * a protocol handler correctly work. 75 */ 76 struct proto_handler { 77 u_int pri; /* Handler priority. */ 78 int16_t dir; /* Flow direction. */ 79 uint8_t proto; /* Working protocol. */ 80 /* Fingerprint * function. */ 81 int (*fingerprint)(struct libalias *, struct alias_data *); 82 /* Aliasing * function. */ 83 int (*protohandler)(struct libalias *, struct ip *, 84 struct alias_data *); 85 TAILQ_ENTRY(proto_handler) link; 86 }; 87 88 /* End of handlers. */ 89 #define EOH .dir = NODIR 90 91 /* Functions used with protocol handlers. */ 92 int LibAliasAttachHandlers(struct proto_handler *); 93 int LibAliasDetachHandlers(struct proto_handler *); 94 int find_handler(int8_t, int8_t, struct libalias *, struct ip *, 95 struct alias_data *); 96 struct proto_handler *first_handler(void); 97 98 #ifndef _KERNEL 99 /* 100 * Used only in userland when libalias needs to keep track of all 101 * module loaded. In kernel land (kld mode) we don't need to care 102 * care about libalias modules cause it's kld to do it for us. 103 */ 104 #define DLL_LEN 32 105 struct dll { 106 char name[DLL_LEN]; /* Name of module. */ 107 void *handle; /* 108 * Ptr to shared obj obtained through 109 * dlopen() - use this ptr to get access 110 * to any symbols from a loaded module 111 * via dlsym(). 112 */ 113 SLIST_ENTRY(dll) next; 114 }; 115 116 /* Functions used with dll module. */ 117 void dll_chain_init(void); 118 void dll_chain_destroy(void); 119 int attach_dll(struct dll *); 120 void *detach_dll(char *); 121 struct dll *walk_dll_chain(void); 122 123 /* 124 * Some defines borrowed from sys/module.h used to compile a kld 125 * in userland as a shared lib. 126 */ 127 typedef enum modeventtype { 128 MOD_LOAD, 129 MOD_UNLOAD, 130 MOD_SHUTDOWN, 131 MOD_QUIESCE 132 } modeventtype_t; 133 134 typedef struct module *module_t; 135 typedef int (*modeventhand_t)(module_t, int /* modeventtype_t */, void *); 136 137 /* 138 * Struct for registering modules statically via SYSINIT. 139 */ 140 typedef struct moduledata { 141 const char *name; /* module name */ 142 modeventhand_t evhand; /* event handler */ 143 void *priv; /* extra data */ 144 } moduledata_t; 145 #endif /* !_KERNEL */ 146 147 #endif /* !_ALIAS_MOD_H_ */ 148