src/libstrongswan/printf_hook.h

   1 /*
   2  * Copyright (C) 2009 Tobias Brunner
   3  * Copyright (C) 2006-2008 Martin Willi
   4  * Hochschule fuer Technik Rapperswil
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2 of the License, or (at your
   9  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  13  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * for more details.
  15  */
  16
  17 /**
  18  * @defgroup printf_hook printf_hook
  19  * @{ @ingroup libstrongswan
  20  */
  21
  22 #ifndef PRINTF_HOOK_H_
  23 #define PRINTF_HOOK_H_
  24
  25 typedef struct printf_hook_t printf_hook_t;
  26 typedef struct printf_hook_spec_t printf_hook_spec_t;
  27 typedef struct printf_hook_data_t printf_hook_data_t;
  28 typedef enum printf_hook_argtype_t printf_hook_argtype_t;
  29
  30 #if !defined(USE_VSTR) && \
  31         !defined(HAVE_PRINTF_FUNCTION) && \
  32         !defined(HAVE_PRINTF_SPECIFIER)
  33 /* assume newer glibc register_printf_specifier if none given */
  34 #define HAVE_PRINTF_SPECIFIER
  35 #endif
  36
  37 #if !defined(USE_VSTR) && \
  38         (defined(HAVE_PRINTF_FUNCTION) || defined(HAVE_PRINTF_SPECIFIER))
  39
  40 #include <stdio.h>
  41 #include <printf.h>
  42
  43 enum printf_hook_argtype_t {
  44         PRINTF_HOOK_ARGTYPE_END = -1,
  45         PRINTF_HOOK_ARGTYPE_INT = PA_INT,
  46         PRINTF_HOOK_ARGTYPE_POINTER = PA_POINTER,
  47 };
  48
  49 /**
  50  * Data to pass to a printf hook.
  51  */
  52 struct printf_hook_data_t {
  53
  54         /**
  55          * Output FILE stream
  56          */
  57         FILE *stream;;
  58 };
  59
  60 /**
  61  * Helper macro to be used in printf hook callbacks.
  62  */
  63 #define print_in_hook(data, fmt, ...) ({\
  64         int _written = fprintf(data->stream, fmt, ##__VA_ARGS__);\
  65         if (_written < 0)\
  66         {\
  67                 _written = 0;\
  68         }\
  69         _written;\
  70 })
  71
  72 #else
  73
  74 #include <vstr.h>
  75
  76 enum printf_hook_argtype_t {
  77         PRINTF_HOOK_ARGTYPE_END = VSTR_TYPE_FMT_END,
  78         PRINTF_HOOK_ARGTYPE_INT = VSTR_TYPE_FMT_INT,
  79         PRINTF_HOOK_ARGTYPE_POINTER = VSTR_TYPE_FMT_PTR_VOID,
  80 };
  81
  82 /**
  83  * Redefining printf and alike
  84  */
  85 #include <stdio.h>
  86 #include <stdarg.h>
  87
  88 int vstr_wrapper_printf(const char *format, ...);
  89 int vstr_wrapper_fprintf(FILE *stream, const char *format, ...);
  90 int vstr_wrapper_sprintf(char *str, const char *format, ...);
  91 int vstr_wrapper_snprintf(char *str, size_t size, const char *format, ...);
  92 int vstr_wrapper_asprintf(char **str, const char *format, ...);
  93
  94 int vstr_wrapper_vprintf(const char *format, va_list ap);
  95 int vstr_wrapper_vfprintf(FILE *stream, const char *format, va_list ap);
  96 int vstr_wrapper_vsprintf(char *str, const char *format, va_list ap);
  97 int vstr_wrapper_vsnprintf(char *str, size_t size, const char *format, va_list ap);
  98 int vstr_wrapper_vasprintf(char **str, const char *format, va_list ap);
  99
 100 #define printf vstr_wrapper_printf
 101 #define fprintf vstr_wrapper_fprintf
 102 #define sprintf vstr_wrapper_sprintf
 103 #define snprintf vstr_wrapper_snprintf
 104 #define asprintf vstr_wrapper_asprintf
 105
 106 #define vprintf vstr_wrapper_vprintf
 107 #define vfprintf vstr_wrapper_vfprintf
 108 #define vsprintf vstr_wrapper_vsprintf
 109 #define vsnprintf vstr_wrapper_vsnprintf
 110 #define vasprintf vstr_wrapper_vasprintf
 111
 112 /**
 113  * Data to pass to a printf hook.
 114  */
 115 struct printf_hook_data_t {
 116
 117         /**
 118          * Base to append printf to
 119          */
 120         Vstr_base *base;
 121
 122         /**
 123          * Position in base to write to
 124          */
 125         size_t pos;
 126 };
 127
 128 /**
 129  * Helper macro to be used in printf hook callbacks.
 130  */
 131 #define print_in_hook(data, fmt, ...) ({\
 132         int _written =  vstr_add_fmt(data->base, data->pos, fmt, ##__VA_ARGS__);\
 133         data->pos += _written;\
 134         _written;\
 135 })
 136
 137 #endif
 138
 139 /**
 140  * Callback function type for printf hooks.
 141  *
 142  * @param data          hook data, to pass to print_in_hook()
 143  * @param spec          format specifier
 144  * @param args          arguments array
 145  * @return                      number of characters written
 146  */
 147 typedef int (*printf_hook_function_t)(printf_hook_data_t *data,
 148                                                                           printf_hook_spec_t *spec,
 149                                                                           const void *const *args);
 150
 151 /**
 152  * Properties of the format specifier
 153  */
 154 struct printf_hook_spec_t {
 155         /**
 156          * TRUE if a '#' was used in the format specifier
 157          */
 158         int hash;
 159
 160         /**
 161          * TRUE if a '-' was used in the format specifier
 162          */
 163         int minus;
 164
 165         /**
 166          * The width as given in the format specifier.
 167          */
 168         int width;
 169 };
 170
 171 /**
 172  * Printf handler management.
 173  */
 174 struct printf_hook_t {
 175
 176         /**
 177          * Register a printf handler.
 178          *
 179          * @param spec          printf hook format character
 180          * @param hook          hook function
 181          * @param ...           list of PRINTF_HOOK_ARGTYPE_*, MUST end with PRINTF_HOOK_ARGTYPE_END
 182          */
 183         void (*add_handler)(printf_hook_t *this, char spec,
 184                                                 printf_hook_function_t hook, ...);
 185
 186         /**
 187          * Destroy a printf_hook instance.
 188          */
 189         void (*destroy)(printf_hook_t *this);
 190 };
 191
 192 /**
 193  * Create a printf_hook instance.
 194  */
 195 printf_hook_t *printf_hook_create();
 196
 197 #endif /** PRINTF_HOOK_H_ @}*/