Source/charon/encoding/payloads/eap_payload.c

   1 /**
   2  * @file eap_payload.c
   3  *
   4  * @brief Implementation of eap_payload_t.
   5  *
   6  */
   7
   8 /*
   9  * Copyright (C) 2005 Jan Hutter, Martin Willi
  10  * Hochschule fuer Technik Rapperswil
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU General Public License as published by the
  14  * Free Software Foundation; either version 2 of the License, or (at your
  15  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  20  * for more details.
  21  */
  22
  23 #include "eap_payload.h"
  24
  25 #include <utils/allocator.h>
  26
  27
  28 typedef struct private_eap_payload_t private_eap_payload_t;
  29
  30 /**
  31  * Private data of an eap_payload_t object.
  32  *
  33  */
  34 struct private_eap_payload_t {
  35         /**
  36          * Public eap_payload_t interface.
  37          */
  38         eap_payload_t public;
  39
  40         /**
  41          * Next payload type.
  42          */
  43         u_int8_t  next_payload;
  44
  45         /**
  46          * Critical flag.
  47          */
  48         bool critical;
  49
  50         /**
  51          * Length of this payload.
  52          */
  53         u_int16_t payload_length;
  54
  55         /**
  56          * The contained message.
  57          */
  58         chunk_t message;
  59 };
  60
  61 /**
  62  * Encoding rules to parse or generate a EAP payload.
  63  *
  64  * The defined offsets are the positions in a object of type
  65  * private_eap_payload_t.
  66  *
  67  */
  68 encoding_rule_t eap_payload_encodings[] = {
  69         /* 1 Byte next payload type, stored in the field next_payload */
  70         { U_INT_8,                      offsetof(private_eap_payload_t, next_payload)   },
  71         /* the critical bit */
  72         { FLAG,                         offsetof(private_eap_payload_t, critical)               },
  73         /* 7 Bit reserved bits, nowhere stored */
  74         { RESERVED_BIT, 0                                                                                                       },
  75         { RESERVED_BIT, 0                                                                                                       },
  76         { RESERVED_BIT, 0                                                                                                       },
  77         { RESERVED_BIT, 0                                                                                                       },
  78         { RESERVED_BIT, 0                                                                                                       },
  79         { RESERVED_BIT, 0                                                                                                       },
  80         { RESERVED_BIT, 0                                                                                                       },
  81         /* Length of the whole payload*/
  82         { PAYLOAD_LENGTH,       offsetof(private_eap_payload_t, payload_length)},
  83         /* some eap data bytes, length is defined in PAYLOAD_LENGTH */
  84         { EAP_MESSAGE,          offsetof(private_eap_payload_t, message)                }
  85 };
  86
  87 /*
  88                            1                   2                   3
  89         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
  90        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  91        ! Next Payload  !C!  RESERVED   !         Payload Length        !
  92        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  93        !                                                               !
  94        ~                       EAP Message                             ~
  95        !                                                               !
  96        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  97 */
  98
  99 /**
 100  * Implementation of payload_t.verify.
 101  */
 102 static status_t verify(private_eap_payload_t *this)
 103 {
 104         if (this->critical)
 105         {
 106                 /* critical bit is set! */
 107                 return FAILED;
 108         }
 109         return SUCCESS;
 110 }
 111
 112 /**
 113  * Implementation of eap_payload_t.get_encoding_rules.
 114  */
 115 static void get_encoding_rules(private_eap_payload_t *this, encoding_rule_t **rules, size_t *rule_count)
 116 {
 117         *rules = eap_payload_encodings;
 118         *rule_count = sizeof(eap_payload_encodings) / sizeof(encoding_rule_t);
 119 }
 120
 121 /**
 122  * Implementation of payload_t.get_type.
 123  */
 124 static payload_type_t get_payload_type(private_eap_payload_t *this)
 125 {
 126         return EXTENSIBLE_AUTHENTICATION;
 127 }
 128
 129 /**
 130  * Implementation of payload_t.get_next_type.
 131  */
 132 static payload_type_t get_next_type(private_eap_payload_t *this)
 133 {
 134         return (this->next_payload);
 135 }
 136
 137 /**
 138  * Implementation of payload_t.set_next_type.
 139  */
 140 static void set_next_type(private_eap_payload_t *this,payload_type_t type)
 141 {
 142         this->next_payload = type;
 143 }
 144
 145 /**
 146  * Implementation of payload_t.get_length.
 147  */
 148 static size_t get_length(private_eap_payload_t *this)
 149 {
 150         return this->payload_length;
 151 }
 152
 153 /**
 154  * Implementation of eap_payload_t.set_message.
 155  */
 156 static void set_message (private_eap_payload_t *this, chunk_t message)
 157 {
 158         if (this->message.ptr != NULL)
 159         {
 160                 allocator_free_chunk(&(this->message));
 161         }
 162         this->message.ptr = allocator_clone_bytes(message.ptr,message.len);
 163         this->message.len = message.len;
 164         this->payload_length = EAP_PAYLOAD_HEADER_LENGTH + this->message.len;
 165 }
 166
 167 /**
 168  * Implementation of eap_payload_t.get_message.
 169  */
 170 static chunk_t get_message (private_eap_payload_t *this)
 171 {
 172         return (this->message);
 173 }
 174
 175 /**
 176  * Implementation of eap_payload_t.get_data_clone.
 177  */
 178 static chunk_t get_message_clone (private_eap_payload_t *this)
 179 {
 180         chunk_t cloned_message;
 181         if (this->message.ptr == NULL)
 182         {
 183                 return (this->message);
 184         }
 185         cloned_message.ptr = allocator_clone_bytes(this->message.ptr,this->message.len);
 186         cloned_message.len = this->message.len;
 187         return cloned_message;
 188 }
 189
 190 /**
 191  * Implementation of payload_t.destroy and eap_payload_t.destroy.
 192  */
 193 static void destroy(private_eap_payload_t *this)
 194 {
 195         if (this->message.ptr != NULL)
 196         {
 197                 allocator_free_chunk(&(this->message));
 198         }
 199
 200         allocator_free(this);
 201 }
 202
 203 /*
 204  * Described in header
 205  */
 206 eap_payload_t *eap_payload_create()
 207 {
 208         private_eap_payload_t *this = allocator_alloc_thing(private_eap_payload_t);
 209
 210         /* interface functions */
 211         this->public.payload_interface.verify = (status_t (*) (payload_t *))verify;
 212         this->public.payload_interface.get_encoding_rules = (void (*) (payload_t *, encoding_rule_t **, size_t *) ) get_encoding_rules;
 213         this->public.payload_interface.get_length = (size_t (*) (payload_t *)) get_length;
 214         this->public.payload_interface.get_next_type = (payload_type_t (*) (payload_t *)) get_next_type;
 215         this->public.payload_interface.set_next_type = (void (*) (payload_t *,payload_type_t)) set_next_type;
 216         this->public.payload_interface.get_type = (payload_type_t (*) (payload_t *)) get_payload_type;
 217         this->public.payload_interface.destroy = (void (*) (payload_t *))destroy;
 218
 219         /* public functions */
 220         this->public.destroy = (void (*) (eap_payload_t *)) destroy;
 221         this->public.set_message = (void (*) (eap_payload_t *,chunk_t)) set_message;
 222         this->public.get_message_clone = (chunk_t (*) (eap_payload_t *)) get_message_clone;
 223         this->public.get_message = (chunk_t (*) (eap_payload_t *)) get_message;
 224
 225         /* private variables */
 226         this->critical = FALSE;
 227         this->next_payload = NO_PAYLOAD;
 228         this->payload_length = EAP_PAYLOAD_HEADER_LENGTH;
 229         this->message = CHUNK_INITIALIZER;
 230
 231         return (&(this->public));
 232 }