src/libstrongswan/metadata/metadata.h

   1 /*
   2  * Copyright (C) 2021 Tobias Brunner
   3  * Copyright (C) 2021 Thomas Egerer
   4  *
   5  * Copyright (C) secunet Security Networks AG
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by the
   9  * Free Software Foundation; either version 2 of the License, or (at your
  10  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15  * for more details.
  16  */
  17
  18 /**
  19  * @defgroup metadata metadata
  20  * @ingroup libstrongswan
  21  *
  22  * @defgroup metadata_t metadata
  23  * @{ @ingroup metadata
  24  */
  25
  26 #ifndef METADATA_H_
  27 #define METADATA_H_
  28
  29 #include <utils/utils.h>
  30
  31 typedef struct metadata_t metadata_t;
  32
  33 /**
  34  * Pre-defined metadata type for int values. Note that while the constructor and
  35  * equals() work with integer values/types smaller than int (such values get
  36  * promoted to int when passed via ...), get() does not and expects a pointer to
  37  * an int variable.
  38  */
  39 #define METADATA_TYPE_INT "int"
  40
  41 /**
  42  * Pre-defined metadata type for uint64_t values. Make sure to pass only
  43  * uint64_t values/variables also to the constructor and equals() (or cast them
  44  * appropriately there).
  45  */
  46 #define METADATA_TYPE_UINT64 "uint64"
  47
  48 /**
  49  * Metadata object to allow storing arbitrary values in an encapsulated
  50  * object.
  51  */
  52 struct metadata_t {
  53
  54         /**
  55          * Return the type of the metadata object.
  56          *
  57          * @return              string type of the metadata object
  58          */
  59         const char *(*get_type)(metadata_t *this);
  60
  61         /**
  62          * Clone this metadata object.
  63          *
  64          * @return              a cloned instance
  65          */
  66         metadata_t *(*clone)(metadata_t *this);
  67
  68         /**
  69          * Compare this to another value (or values, depending on the type).
  70          *
  71          * @param ...   value(s) (raw, not metadata_t) to compare this to
  72          * @return              TRUE if value is equal to metadata value
  73          */
  74         bool (*equals)(metadata_t *this, ...);
  75
  76         /**
  77          * Retrieve the values via variadic argument(s).
  78          *
  79          * @param ...   pointer(s) to obtain metadata value(s)
  80          */
  81         void (*get)(metadata_t *this, ...);
  82
  83         /**
  84          * Destroy this metadata object.
  85          */
  86         void (*destroy)(metadata_t *this);
  87 };
  88
  89 /**
  90  * Constructor type for metadata objects.
  91  *
  92  * @param type          type of the metadata object, allows using the same
  93  *                                      constructor for different types
  94  * @param args          type-specific arguments
  95  * @return                      metadata object, NULL on failure
  96  */
  97 typedef metadata_t *(*metadata_create_t)(const char *type, va_list args);
  98
  99 #endif /** METADATA_H_ @}*/