sys/net/libalias/alias_mod.h

   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: src/sys/netinet/libalias/alias_mod.h,v 1.1.6.1 2008/11/25 02:59:29 kensmith Exp $
  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
  38 /* Protocol handlers struct & function. */
  39
  40 /* Packet flow direction. */
  41 #define IN                              1
  42 #define OUT                             2
  43
  44 /* Working protocol. */
  45 #define IP                              1
  46 #define TCP                             2
  47 #define UDP                             4
  48
  49 /*
  50  * Data passed to protocol handler module, it must be filled
  51  * right before calling find_handler() to determine which
  52  * module is elegible to be called.
  53  */
  54
  55 struct alias_data {
  56         struct alias_link       *lnk;
  57         struct in_addr          *oaddr;         /* Original address. */
  58         struct in_addr          *aaddr;         /* Alias address. */
  59         uint16_t                *aport;         /* Alias port. */
  60         uint16_t                *sport, *dport; /* Source & destination port */
  61         uint16_t                maxpktsize;     /* Max packet size. */
  62 };
  63
  64 /*
  65  * This structure contains all the information necessary to make
  66  * a protocol handler correctly work.
  67  */
  68
  69 struct proto_handler {
  70         u_int pri;                                              /* Handler priority. */
  71         int16_t dir;                                            /* Flow direction. */
  72         uint8_t proto;                                          /* Working protocol. */
  73         int (*fingerprint)(struct libalias *la,                 /* Fingerprint * function. */
  74                  struct ip *pip, struct alias_data *ah);
  75         int (*protohandler)(struct libalias *la,                /* Aliasing * function. */
  76                  struct ip *pip, struct alias_data *ah);
  77         LIST_ENTRY(proto_handler) entries;
  78 };
  79
  80
  81 /*
  82  * Used only in userland when libalias needs to keep track of all
  83  * module loaded. In kernel land (kld mode) we don't need to care
  84  * care about libalias modules cause it's kld to do it for us.
  85  */
  86
  87 #define DLL_LEN         32
  88 struct dll {
  89         char            name[DLL_LEN];  /* Name of module. */
  90         void            *handle;        /*
  91                                          * Ptr to shared obj obtained through
  92                                          * dlopen() - use this ptr to get access
  93                                          * to any symbols from a loaded module
  94                                          * via dlsym().
  95                                          */
  96         SLIST_ENTRY(dll)        next;
  97 };
  98
  99 /* Functions used with protocol handlers. */
 100
 101 void            handler_chain_init(void);
 102 void            handler_chain_destroy(void);
 103 int             LibAliasAttachHandlers(struct proto_handler *);
 104 int             LibAliasDetachHandlers(struct proto_handler *);
 105 int             detach_handler(struct proto_handler *);
 106 int             find_handler(int8_t, int8_t, struct libalias *,
 107                            struct ip *, struct alias_data *);
 108 struct proto_handler *first_handler(void);
 109
 110 /* Functions used with dll module. */
 111
 112 void            dll_chain_init(void);
 113 void            dll_chain_destroy(void);
 114 int             attach_dll(struct dll *);
 115 void            *detach_dll(char *);
 116 struct dll      *walk_dll_chain(void);
 117
 118 /* End of handlers. */
 119 #define EOH     -1
 120
 121 /*
 122  * Some defines borrowed from sys/module.h used to compile a kld
 123  * in userland as a shared lib.
 124  */
 125
 126 #ifdef  _KERNEL
 127
 128 #else
 129 typedef enum modeventtype {
 130         MOD_LOAD,
 131         MOD_UNLOAD,
 132         MOD_SHUTDOWN,
 133         MOD_QUIESCE
 134 } modeventtype_t;
 135
 136 typedef struct module *module_t;
 137 typedef int (*modeventhand_t)(module_t, int /* modeventtype_t */, void *);
 138
 139 /*
 140  * Struct for registering modules statically via SYSINIT.
 141  */
 142 typedef struct moduledata {
 143         const char      *name;          /* module name */
 144         modeventhand_t  evhand;         /* event handler */
 145         void            *priv;          /* extra data */
 146 } moduledata_t;
 147 #endif
 148
 149 #endif                          /* !_ALIAS_MOD_H_ */