path: root/src/include/gnunet_common.h

/*
     This file is part of GNUnet.
     (C) 2006, 2009 Christian Grothoff (and other contributing authors)

     GNUnet is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published
     by the Free Software Foundation; either version 2, or (at your
     option) any later version.

     GNUnet is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with GNUnet; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.
*/

/**
 * @file include/gnunet_common.h
 * @brief commonly used definitions; globals in this file
 *        are exempt from the rule that the module name ("common")
 *        must be part of the symbol name.
 *
 * @author Christian Grothoff
 * @author Nils Durner
 */
#ifndef GNUNET_COMMON_H
#define GNUNET_COMMON_H

#if HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#if HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef MINGW
#include "winproc.h"
#endif
#ifdef HAVE_STDINT_H
#include <stdint.h>
#endif
#ifdef HAVE_STDARG_H
#include <stdarg.h>
#endif

/**
 * Version of the API (for entire gnunetutil.so library).
 */
#define GNUNET_UTIL_VERSION 0x00090200

/**
 * Named constants for return values.  The following
 * invariants hold: "GNUNET_NO == 0" (to allow "if (GNUNET_NO)")
 * "GNUNET_OK != GNUNET_SYSERR", "GNUNET_OK != GNUNET_NO", "GNUNET_NO != GNUNET_SYSERR"
 * and finally "GNUNET_YES != GNUNET_NO".
 */
#define GNUNET_OK      1
#define GNUNET_SYSERR -1
#define GNUNET_YES     1
#define GNUNET_NO      0

#define GNUNET_MIN(a,b) (((a) < (b)) ? (a) : (b))

#define GNUNET_MAX(a,b) (((a) > (b)) ? (a) : (b))

/* some systems use one underscore only, and mingw uses no underscore... */
#ifndef __BYTE_ORDER
#ifdef _BYTE_ORDER
#define __BYTE_ORDER _BYTE_ORDER
#else
#ifdef BYTE_ORDER
#define __BYTE_ORDER BYTE_ORDER
#endif
#endif
#endif
#ifndef __BIG_ENDIAN
#ifdef _BIG_ENDIAN
#define __BIG_ENDIAN _BIG_ENDIAN
#else
#ifdef BIG_ENDIAN
#define __BIG_ENDIAN BIG_ENDIAN
#endif
#endif
#endif
#ifndef __LITTLE_ENDIAN
#ifdef _LITTLE_ENDIAN
#define __LITTLE_ENDIAN _LITTLE_ENDIAN
#else
#ifdef LITTLE_ENDIAN
#define __LITTLE_ENDIAN LITTLE_ENDIAN
#endif
#endif
#endif

/**
 * Endian operations
 */

# if __BYTE_ORDER == __LITTLE_ENDIAN
#  define GNUNET_htobe16(x) __bswap_16 (x)
#  define GNUNET_htole16(x) (x)
#  define GNUNET_be16toh(x) __bswap_16 (x)
#  define GNUNET_le16toh(x) (x)

#  define GNUNET_htobe32(x) __bswap_32 (x)
#  define GNUNET_htole32(x) (x)
#  define GNUNET_be32toh(x) __bswap_32 (x)
#  define GNUNET_le32toh(x) (x)

#  define GNUNET_htobe64(x) __bswap_64 (x)
#  define GNUNET_htole64(x) (x)
#  define GNUNET_be64toh(x) __bswap_64 (x)
#  define GNUNET_le64toh(x) (x)
#endif
# if __BYTE_ORDER == __BIG_ENDIAN
#  define GNUNET_htobe16(x) (x)
#  define GNUNET_htole16(x) __bswap_16 (x)
#  define GNUNET_be16toh(x) (x)
#  define GNUNET_le16toh(x) __bswap_16 (x)

#  define GNUNET_htobe32(x) (x)
#  define GNUNET_htole32(x) __bswap_32 (x)
#  define GNUNET_be32toh(x) (x)
#  define GNUNET_le32toh(x) __bswap_32 (x)

#  define GNUNET_htobe64(x) (x)
#  define GNUNET_htole64(x) __bswap_64 (x)
#  define GNUNET_be64toh(x) (x)
#  define GNUNET_le64toh(x) __bswap_64 (x)
#endif




/**
 * gcc-ism to get packed structs.
 */
#define GNUNET_PACKED __attribute__((packed))

/**
 * gcc-ism to get gcc bitfield layout when compiling with -mms-bitfields
 */
#if MINGW
#define GNUNET_GCC_STRUCT_LAYOUT __attribute__((gcc_struct))
#else
#define GNUNET_GCC_STRUCT_LAYOUT
#endif

/**
 * gcc-ism to force alignment; we use this to align char-arrays
 * that may then be cast to 'struct's.  See also gcc
 * bug #33594.
 */
#ifdef __BIGGEST_ALIGNMENT__
#define GNUNET_ALIGN __attribute__((aligned (__BIGGEST_ALIGNMENT__)))
#else
#define GNUNET_ALIGN __attribute__((aligned (8)))
#endif

/**
 * gcc-ism to document unused arguments
 */
#define GNUNET_UNUSED __attribute__((unused))

/**
 * gcc-ism to document functions that don't return
 */
#define GNUNET_NORETURN __attribute__((noreturn))

#if __GNUC__ > 3
/**
 * gcc 4.x-ism to pack structures even on W32 (to be used before structs)
 */
#define GNUNET_NETWORK_STRUCT_BEGIN \
  _Pragma("pack(push)") \
  _Pragma("pack(1)")

/**
 * gcc 4.x-ism to pack structures even on W32 (to be used after structs)
 */
#define GNUNET_NETWORK_STRUCT_END _Pragma("pack(pop)")
#else
#ifdef MINGW
#error gcc 4.x or higher required on W32 systems
#endif
/**
 * Good luck, GNUNET_PACKED should suffice, but this won't work on W32
 */
#define GNUNET_NETWORK_STRUCT_BEGIN 

/**
 * Good luck, GNUNET_PACKED should suffice, but this won't work on W32
 */
#define GNUNET_NETWORK_STRUCT_END
#endif

/* ************************ super-general types *********************** */

GNUNET_NETWORK_STRUCT_BEGIN

/**
 * Header for all communications.
 */
struct GNUNET_MessageHeader
{

  /**
   * The length of the struct (in bytes, including the length field itself),
   * in big-endian format.
   */
  uint16_t size GNUNET_PACKED;

  /**
   * The type of the message (GNUNET_MESSAGE_TYPE_XXXX), in big-endian format.
   */
  uint16_t type GNUNET_PACKED;

};


/**
 * @brief 512-bit hashcode
 */
typedef struct GNUNET_HashCode
{
  uint32_t bits[512 / 8 / sizeof (uint32_t)];   /* = 16 */
}
GNUNET_HashCode;


/**
 * The identity of the host (basically the SHA-512 hashcode of
 * it's public key).
 */
struct GNUNET_PeerIdentity
{
  GNUNET_HashCode hashPubKey;
};
GNUNET_NETWORK_STRUCT_END

/**
 * Function called with a filename.
 *
 * @param cls closure
 * @param filename complete filename (absolute path)
 * @return GNUNET_OK to continue to iterate,
 *  GNUNET_SYSERR to abort iteration with error!
 */
typedef int (*GNUNET_FileNameCallback) (void *cls, const char *filename);


/* ****************************** logging ***************************** */

/**
 * Types of errors.
 */
enum GNUNET_ErrorType
{
  GNUNET_ERROR_TYPE_UNSPECIFIED = -1,
  GNUNET_ERROR_TYPE_NONE = 0,
  GNUNET_ERROR_TYPE_ERROR = 1,
  GNUNET_ERROR_TYPE_WARNING = 2,
  GNUNET_ERROR_TYPE_INFO = 4,
  GNUNET_ERROR_TYPE_DEBUG = 8,
  GNUNET_ERROR_TYPE_INVALID = 16,
  GNUNET_ERROR_TYPE_BULK = 32
};


/**
 * User-defined handler for log messages.
 *
 * @param cls closure
 * @param kind severeity
 * @param component what component is issuing the message?
 * @param date when was the message logged?
 * @param message what is the message
 */
typedef void (*GNUNET_Logger) (void *cls, enum GNUNET_ErrorType kind,
                               const char *component, const char *date,
                               const char *message);


/**
 * Number of log calls to ignore.
 */
extern unsigned int skip_log;

#if !defined(GNUNET_CULL_LOGGING)
int
GNUNET_get_log_call_status (int caller_level, const char *comp,
                            const char *file, const char *function, int line);
#endif
/**
 * Main log function.
 *
 * @param kind how serious is the error?
 * @param message what is the message (format string)
 * @param ... arguments for format string
 */
void
GNUNET_log_nocheck (enum GNUNET_ErrorType kind, const char *message, ...);

/* from glib */
#if defined(__GNUC__) && (__GNUC__ > 2) && defined(__OPTIMIZE__)
#define _GNUNET_BOOLEAN_EXPR(expr)              \
 __extension__ ({                               \
   int _gnunet_boolean_var_;                    \
   if (expr)                                    \
      _gnunet_boolean_var_ = 1;                 \
   else                                         \
      _gnunet_boolean_var_ = 0;                 \
   _gnunet_boolean_var_;                        \
})
#define GN_LIKELY(expr) (__builtin_expect (_GNUNET_BOOLEAN_EXPR(expr), 1))
#define GN_UNLIKELY(expr) (__builtin_expect (_GNUNET_BOOLEAN_EXPR(expr), 0))
#else
#define GN_LIKELY(expr) (expr)
#define GN_UNLIKELY(expr) (expr)
#endif

#if !defined(GNUNET_LOG_CALL_STATUS)
#define GNUNET_LOG_CALL_STATUS -1
#endif

/**
 * Log function that specifies an alternative component.
 * This function should be used by plugins.
 *
 * @param kind how serious is the error?
 * @param comp component responsible for generating the message
 * @param message what is the message (format string)
 * @param ... arguments for format string
 */
void
GNUNET_log_from_nocheck (enum GNUNET_ErrorType kind, const char *comp,
                         const char *message, ...);

#if !defined(GNUNET_CULL_LOGGING)
#define GNUNET_log_from(kind,comp,...) do { int log_line = __LINE__;\
  static int log_call_enabled = GNUNET_LOG_CALL_STATUS;\
  if ((GNUNET_EXTRA_LOGGING > 0) || ((GNUNET_ERROR_TYPE_DEBUG & (kind)) == 0)) { \
    if (GN_UNLIKELY(log_call_enabled == -1))\
      log_call_enabled = GNUNET_get_log_call_status ((kind) & (~GNUNET_ERROR_TYPE_BULK), (comp), __FILE__, __FUNCTION__, log_line); \
    if (GN_UNLIKELY(skip_log > 0)) {skip_log--;}\
    else {\
      if (GN_UNLIKELY(log_call_enabled))\
        GNUNET_log_from_nocheck ((kind), comp, __VA_ARGS__);	\
    }\
  }\
} while (0)

#define GNUNET_log(kind,...) do { int log_line = __LINE__;\
  static int log_call_enabled = GNUNET_LOG_CALL_STATUS;\
  if ((GNUNET_EXTRA_LOGGING > 0) || ((GNUNET_ERROR_TYPE_DEBUG & (kind)) == 0)) { \
    if (GN_UNLIKELY(log_call_enabled == -1))\
      log_call_enabled = GNUNET_get_log_call_status ((kind) & (~GNUNET_ERROR_TYPE_BULK), NULL, __FILE__, __FUNCTION__, log_line);\
    if (GN_UNLIKELY(skip_log > 0)) {skip_log--;}\
    else {\
      if (GN_UNLIKELY(log_call_enabled))\
        GNUNET_log_nocheck ((kind), __VA_ARGS__);	\
    }\
  }\
} while (0)
#else
#define GNUNET_log(...)
#define GNUNET_log_from(...)
#endif


/**
 * Abort the process, generate a core dump if possible.
 */
void
GNUNET_abort (void) GNUNET_NORETURN;

/**
 * Ignore the next n calls to the log function.
 *
 * @param n number of log calls to ignore
 * @param check_reset GNUNET_YES to assert that the log skip counter is currently zero
 */
void
GNUNET_log_skip (unsigned int n, int check_reset);


/**
 * Setup logging.
 *
 * @param comp default component to use
 * @param loglevel what types of messages should be logged
 * @param logfile change logging to logfile (use NULL to keep stderr)
 * @return GNUNET_OK on success, GNUNET_SYSERR if logfile could not be opened
 */
int
GNUNET_log_setup (const char *comp, const char *loglevel, const char *logfile);


/**
 * Add a custom logger.
 *
 * @param logger log function
 * @param logger_cls closure for logger
 */
void
GNUNET_logger_add (GNUNET_Logger logger, void *logger_cls);


/**
 * Remove a custom logger.
 *
 * @param logger log function
 * @param logger_cls closure for logger
 */
void
GNUNET_logger_remove (GNUNET_Logger logger, void *logger_cls);


/**
 * Convert a hash value to a string (for printing debug messages).
 * This is one of the very few calls in the entire API that is
 * NOT reentrant!
 *
 * @param hc the hash code
 * @return string
 */
const char *
GNUNET_h2s (