- defined all substructures for a SA payload
[strongswan.git] / Source / charon / payloads / transform_attribute.c
1 /**
2 * @file transform_attribute.c
3 *
4 * @brief Declaration of the class transform_attribute_t.
5 *
6 * An object of this type represents an IKEv2 TRANSFORM attribute.
7 *
8 */
9
10 /*
11 * Copyright (C) 2005 Jan Hutter, Martin Willi
12 * Hochschule fuer Technik Rapperswil
13 *
14 * This program is free software; you can redistribute it and/or modify it
15 * under the terms of the GNU General Public License as published by the
16 * Free Software Foundation; either version 2 of the License, or (at your
17 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
18 *
19 * This program is distributed in the hope that it will be useful, but
20 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
21 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
22 * for more details.
23 */
24
25 /* offsetof macro */
26 #include <stddef.h>
27
28 #include "transform_attribute.h"
29
30 #include "encodings.h"
31 #include "../types.h"
32 #include "../utils/allocator.h"
33
34 /**
35 * Private data of an transform_attribute_t Object
36 *
37 */
38 typedef struct private_transform_attribute_s private_transform_attribute_t;
39
40 struct private_transform_attribute_s {
41 /**
42 * public transform_attribute_t interface
43 */
44 transform_attribute_t public;
45
46 /**
47 * Attribute Format Flag
48 *
49 * - TRUE means value is stored in attribute_length_or_value
50 * - FALSE means value is stored in attribute_value
51 */
52 bool attribute_format;
53
54 /**
55 * Type of the attribute
56 */
57 u_int16_t attribute_type;
58
59 /**
60 * Attribute Length if attribute_format is 0, attribute Value otherwise
61 */
62 u_int8_t attribute_length_or_value;
63
64 /**
65 * Attribute value as chunk if attribute_format is 0 (FALSE)
66 */
67 chunk_t attribute_value;
68 };
69
70
71 /**
72 * Encoding rules to parse or generate a Transform attribute
73 *
74 * The defined offsets are the positions in a object of type
75 * private_transform_attribute_t.
76 *
77 */
78 encoding_rule_t transform_attribute_encodings[] = {
79 /* Flag defining the format of this payload */
80 { ATTRIBUTE_FORMAT, offsetof(private_transform_attribute_t, attribute_format) },
81 /* type of the attribute as 15 bit unsigned integer */
82 { ATTRIBUTE_TYPE, offsetof(private_transform_attribute_t, attribute_type) },
83 /* Length or value, depending on the attribute format flag */
84 { ATTRIBUTE_LENGTH_OR_VALUE, offsetof(private_transform_attribute_t, attribute_length_or_value) },
85 /* Value of attribute if attribute format flag is zero */
86 { ATTRIBUTE_VALUE, offsetof(private_transform_attribute_t, attribute_value) }
87 };
88
89 /**
90 * Implements payload_t's and transform_attribute_t's destroy function.
91 * See #payload_s.destroy or transform_attribute_s.destroy for description.
92 */
93 static status_t destroy(private_transform_attribute_t *this)
94 {
95 if (this->attribute_value.ptr != NULL)
96 {
97 allocator_free(this->attribute_value.ptr);
98 }
99 allocator_free(this);
100
101 return SUCCESS;
102 }
103
104 /**
105 * Implements payload_t's get_encoding_rules function.
106 * See #payload_s.get_encoding_rules for description.
107 */
108 static status_t get_encoding_rules(private_transform_attribute_t *this, encoding_rule_t **rules, size_t *rule_count)
109 {
110 *rules = transform_attribute_encodings;
111 *rule_count = sizeof(transform_attribute_encodings) / sizeof(encoding_rule_t);
112
113 return SUCCESS;
114 }
115
116 /**
117 * Implements payload_t's get_type function.
118 * See #payload_s.get_type for description.
119 */
120 static payload_type_t get_type(private_transform_attribute_t *this)
121 {
122 return TRANSFORM_ATTRIBUTE;
123 }
124
125 /**
126 * Implements payload_t's get_next_type function.
127 * See #payload_s.get_next_type for description.
128 */
129 static payload_type_t get_next_type(private_transform_attribute_t *this)
130 {
131 return (NO_PAYLOAD);
132 }
133
134 /**
135 * Implements payload_t's get_length function.
136 * See #payload_s.get_length for description.
137 */
138 static size_t get_length(private_transform_attribute_t *this)
139 {
140 if (this->attribute_format == TRUE)
141 {
142 /*Attribute size is only 4 byte */
143 return 4;
144 }
145 return (this->attribute_length_or_value + 4);
146 }
147
148 /*
149 * Described in header
150 */
151 transform_attribute_t *transform_attribute_create()
152 {
153 private_transform_attribute_t *this = allocator_alloc_thing(private_transform_attribute_t);
154 if (this == NULL)
155 {
156 return NULL;
157 }
158
159 this->public.payload_interface.get_encoding_rules = (status_t (*) (payload_t *, encoding_rule_t **, size_t *) ) get_encoding_rules;
160 this->public.payload_interface.get_length = (size_t (*) (payload_t *)) get_length;
161 this->public.payload_interface.get_next_type = (payload_type_t (*) (payload_t *)) get_next_type;
162 this->public.payload_interface.get_type = (payload_type_t (*) (payload_t *)) get_type;
163 this->public.payload_interface.destroy = (status_t (*) (payload_t *))destroy;
164 this->public.destroy = (status_t (*) (transform_attribute_t *)) destroy;
165
166 /* set default values of the fields */
167 this->attribute_format = TRUE;
168 this->attribute_type = 0;
169 this->attribute_length_or_value = 0;
170 this->attribute_value.ptr = NULL;
171 this->attribute_value.len = 0;
172
173 return (&(this->public));
174 }
175