linux/include/freeswan/ipsec_alg.h

   1 /*
   2  * Modular extensions service and registration functions interface
   3  *
   4  * Author: JuanJo Ciarlante <jjo-ipsec@mendoza.gov.ar>
   5  *
   6  * $Id: ipsec_alg.h,v 1.2 2004/03/22 21:53:18 as Exp $
   7  *
   8  */
   9 /*
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License as published by the
  12  * Free Software Foundation; either version 2 of the License, or (at your
  13  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  17  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  18  * for more details.
  19  *
  20  */
  21 #ifndef IPSEC_ALG_H
  22 #define IPSEC_ALG_H
  23
  24 /*
  25  *   gcc >= 3.2 has removed __FUNCTION__, replaced by C99 __func__
  26  *   *BUT* its a compiler variable.
  27  */
  28 #if (__GNUC__ >= 3)
  29 #ifndef __FUNCTION__
  30 #define __FUNCTION__ __func__
  31 #endif
  32 #endif
  33
  34 /*      Version 0.8.1-0 */
  35 #define IPSEC_ALG_VERSION       0x00080100
  36
  37 #include <linux/types.h>
  38 #include <linux/list.h>
  39 #include <asm/atomic.h>
  40 /*
  41  *      The following structs are used via pointers in ipsec_alg object to
  42  *      avoid ipsec_alg.h coupling with freeswan headers, thus simplifying
  43  *      module development
  44  */
  45 struct ipsec_sa;
  46 struct esp;
  47
  48 /**************************************
  49  *
  50  *      Main registration object
  51  *
  52  *************************************/
  53 #define IPSEC_ALG_VERSION_QUAD(v)       \
  54         (v>>24),((v>>16)&0xff),((v>>8)&0xff),(v&0xff)
  55 /*
  56  *      Main ipsec_alg objects: "OOPrograming wannabe"
  57  *      Hierachy (carefully handled with _minimal_ cast'ing):
  58  *
  59  *      ipsec_alg+
  60  *               +->ipsec_alg_enc  (ixt_alg_type=SADB_EXT_SUPPORTED_ENCRYPT)
  61  *               +->ipsec_alg_auth (ixt_alg_type=SADB_EXT_SUPPORTED_AUTH)
  62  */
  63
  64 /***************************************************************
  65  *
  66  *      INTERFACE object: struct ipsec_alg
  67  *
  68  ***************************************************************/
  69
  70 /*
  71  *      common part for every struct ipsec_alg_*
  72  *      (sortof poor's man OOP)
  73  */
  74 #define IPSEC_ALG_STRUCT_COMMON \
  75         unsigned ixt_version;   /* only allow this version (or 'near')*/ \
  76         struct list_head ixt_list;      /* dlinked list */ \
  77         struct module *ixt_module;      /* THIS_MODULE */ \
  78         unsigned ixt_state;             /* state flags */ \
  79         atomic_t ixt_refcnt;    /* ref. count when pointed from ipsec_sa */ \
  80         char ixt_name[16];      /* descriptive short name, eg. "3des" */ \
  81         void *ixt_data;         /* private for algo implementation */ \
  82         uint8_t  ixt_blocksize; /* blocksize in bytes */ \
  83         \
  84         /* THIS IS A COPY of struct supported (lib/pfkey.h)        \
  85          * please keep in sync until we migrate 'supported' stuff  \
  86          * to ipsec_alg \
  87          */ \
  88         uint16_t ixt_alg_type;  /* correspond to IPSEC_ALG_{ENCRYPT,AUTH} */ \
  89         uint8_t  ixt_alg_id;    /* enc. alg. number, eg. ESP_3DES */ \
  90         uint8_t  ixt_ivlen;     /* ivlen in bits, expected to be multiple of 8! */ \
  91         uint16_t ixt_keyminbits;/* min. keybits (of entropy) */ \
  92         uint16_t ixt_keymaxbits;/* max. keybits (of entropy) */
  93
  94 #define ixt_support ixt_alg_type
  95
  96 #define IPSEC_ALG_ST_SUPP       0x01
  97 #define IPSEC_ALG_ST_REGISTERED 0x02
  98 #define IPSEC_ALG_ST_EXCL       0x04
  99 struct ipsec_alg {
 100         IPSEC_ALG_STRUCT_COMMON
 101 };
 102 /*
 103  *      Note the const in cbc_encrypt IV arg:
 104  *      some ciphers like to toast passed IV (eg. 3DES): make a local IV copy
 105  */
 106 struct ipsec_alg_enc {
 107         IPSEC_ALG_STRUCT_COMMON
 108         unsigned ixt_e_keylen;          /* raw key length in bytes          */
 109         unsigned ixt_e_ctx_size;        /* sa_p->key_e_size */
 110         int (*ixt_e_set_key)(struct ipsec_alg_enc *alg, __u8 *key_e, const __u8 *key, size_t keysize);
 111         __u8 *(*ixt_e_new_key)(struct ipsec_alg_enc *alg, const __u8 *key, size_t keysize);
 112         void (*ixt_e_destroy_key)(struct ipsec_alg_enc *alg, __u8 *key_e);
 113         int (*ixt_e_cbc_encrypt)(struct ipsec_alg_enc *alg, __u8 *key_e, __u8 *in, int ilen, const __u8 *iv, int encrypt);
 114 };
 115 struct ipsec_alg_auth {
 116         IPSEC_ALG_STRUCT_COMMON
 117         unsigned ixt_a_keylen;          /* raw key length in bytes          */
 118         unsigned ixt_a_ctx_size;        /* sa_p->key_a_size */
 119         unsigned ixt_a_authlen;         /* 'natural' auth. hash len (bytes) */
 120         int (*ixt_a_hmac_set_key)(struct ipsec_alg_auth *alg, __u8 *key_a, const __u8 *key, int keylen);
 121         int (*ixt_a_hmac_hash)(struct ipsec_alg_auth *alg, __u8 *key_a, const __u8 *dat, int len, __u8 *hash, int hashlen);
 122 };
 123 /*
 124  *      These are _copies_ of SADB_EXT_SUPPORTED_{AUTH,ENCRYPT},
 125  *      to avoid header coupling for true constants
 126  *      about headers ... "cp is your friend" --Linus
 127  */
 128 #define IPSEC_ALG_TYPE_AUTH     14
 129 #define IPSEC_ALG_TYPE_ENCRYPT  15
 130
 131 /***************************************************************
 132  *
 133  *      INTERFACE for module loading,testing, and unloading
 134  *
 135  ***************************************************************/
 136 /*      -  registration calls   */
 137 int register_ipsec_alg(struct ipsec_alg *);
 138 int unregister_ipsec_alg(struct ipsec_alg *);
 139 /*      -  optional (simple test) for algos     */
 140 int ipsec_alg_test(unsigned alg_type, unsigned alg_id, int testparm);
 141 /*      inline wrappers (usefull for type validation */
 142 static inline int register_ipsec_alg_enc(struct ipsec_alg_enc *ixt) {
 143         return register_ipsec_alg((struct ipsec_alg*)ixt);
 144 }
 145 static inline int unregister_ipsec_alg_enc(struct ipsec_alg_enc *ixt) {
 146         return unregister_ipsec_alg((struct ipsec_alg*)ixt);
 147 }
 148 static inline int register_ipsec_alg_auth(struct ipsec_alg_auth *ixt) {
 149         return register_ipsec_alg((struct ipsec_alg*)ixt);
 150 }
 151 static inline int unregister_ipsec_alg_auth(struct ipsec_alg_auth *ixt) {
 152         return unregister_ipsec_alg((struct ipsec_alg*)ixt);
 153 }
 154
 155 /*****************************************************************
 156  *
 157  *      INTERFACE for ENC services: key creation, encrypt function
 158  *
 159  *****************************************************************/
 160
 161 #define IPSEC_ALG_ENCRYPT 1
 162 #define IPSEC_ALG_DECRYPT 0
 163
 164 /*      encryption key context creation function */
 165 int ipsec_alg_enc_key_create(struct ipsec_sa *sa_p);
 166 /*
 167  *      ipsec_alg_esp_encrypt(): encrypt ilen bytes in idat returns
 168  *      0 or ERR<0
 169  */
 170 int ipsec_alg_esp_encrypt(struct ipsec_sa *sa_p, __u8 *idat, int ilen, const __u8 *iv, int action);
 171
 172 /***************************************************************
 173  *
 174  *      INTERFACE for AUTH services: key creation, hash functions
 175  *
 176  ***************************************************************/
 177 int ipsec_alg_auth_key_create(struct ipsec_sa *sa_p);
 178 int ipsec_alg_sa_esp_hash(const struct ipsec_sa *sa_p, const __u8 *espp, int len, __u8 *hash, int hashlen) ;
 179 #define ipsec_alg_sa_esp_update(c,k,l) ipsec_alg_sa_esp_hash(c,k,l,NULL,0)
 180
 181 /* only called from ipsec_init.c */
 182 int ipsec_alg_init(void);
 183
 184 /* algo module glue for static algos */
 185 void ipsec_alg_static_init(void);
 186 typedef int (*ipsec_alg_init_func_t) (void);
 187
 188 /**********************************************
 189  *
 190  *      INTERFACE for ipsec_sa init and wipe
 191  *
 192  **********************************************/
 193
 194 /* returns true if ipsec_sa has ipsec_alg obj attached */
 195 /*
 196  * Initializes ipsec_sa's ipsec_alg object, using already loaded
 197  * proto, authalg, encalg.; links ipsec_alg objects (enc, auth)
 198  */
 199 int ipsec_alg_sa_init(struct ipsec_sa *sa_p);
 200 /*
 201  * Destroys ipsec_sa's ipsec_alg object
 202  * unlinking ipsec_alg objects
 203  */
 204 int ipsec_alg_sa_wipe(struct ipsec_sa *sa_p);
 205
 206 /**********************************************
 207  *
 208  *      2.2 backport for some 2.4 useful module stuff
 209  *
 210  **********************************************/
 211 #ifdef MODULE
 212 #ifndef THIS_MODULE
 213 #define THIS_MODULE          (&__this_module)
 214 #endif
 215 #ifndef module_init
 216 typedef int (*__init_module_func_t)(void);
 217 typedef void (*__cleanup_module_func_t)(void);
 218
 219 #define module_init(x) \
 220         int init_module(void) __attribute__((alias(#x))); \
 221         static inline __init_module_func_t __init_module_inline(void) \
 222         { return x; }
 223 #define module_exit(x) \
 224         void cleanup_module(void) __attribute__((alias(#x))); \
 225         static inline __cleanup_module_func_t __cleanup_module_inline(void) \
 226         { return x; }
 227 #endif
 228
 229 #define IPSEC_ALG_MODULE_INIT( func_name )      \
 230         static int func_name(void);             \
 231         module_init(func_name);                 \
 232         static int __init func_name(void)
 233 #define IPSEC_ALG_MODULE_EXIT( func_name )      \
 234         static void func_name(void);            \
 235         module_exit(func_name);                 \
 236         static void __exit func_name(void)
 237 #else   /* not MODULE */
 238 #ifndef THIS_MODULE
 239 #define THIS_MODULE          NULL
 240 #endif
 241 /*
 242  *      I only want module_init() magic
 243  *      when algo.c file *is THE MODULE*, in all other
 244  *      cases, initialization is called explicitely from ipsec_alg_init()
 245  */
 246 #define IPSEC_ALG_MODULE_INIT( func_name )      \
 247         extern int func_name(void);             \
 248         int func_name(void)
 249 #define IPSEC_ALG_MODULE_EXIT( func_name )      \
 250         extern void func_name(void);            \
 251         void func_name(void)
 252 #endif
 253
 254 #endif /* IPSEC_ALG_H */