include/openssl/trace.h

   1 /*
   2  * Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #ifndef OPENSSL_TRACE_H
  11 # define OPENSSL_TRACE_H
  12
  13 # include <stdarg.h>
  14
  15 # include <openssl/bio.h>
  16
  17 # ifdef  __cplusplus
  18 extern "C" {
  19 # endif
  20
  21 /*
  22  * TRACE CATEGORIES
  23  */
  24
  25 /*
  26  * The trace messages of the OpenSSL libraries are organized into different
  27  * categories. For every trace category, the application can register a separate
  28  * tracer callback. When a callback is registered, a so called trace channel is
  29  * created for this category. This channel consists essentially of an internal
  30  * BIO which sends all trace output it receives to the registered application
  31  * callback.
  32  *
  33  * The ALL category can be used as a fallback category to register a single
  34  * channel which receives the output from all categories. However, if the
  35  * application intends to print the trace channel name in the line prefix,
  36  * it is better to register channels for all categories separately.
  37  * (This is how the openssl application does it.)
  38  */
  39 # define OSSL_TRACE_CATEGORY_ALL                 0 /* The fallback */
  40 # define OSSL_TRACE_CATEGORY_TRACE               1
  41 # define OSSL_TRACE_CATEGORY_INIT                2
  42 # define OSSL_TRACE_CATEGORY_TLS                 3
  43 # define OSSL_TRACE_CATEGORY_TLS_CIPHER          4
  44 # define OSSL_TRACE_CATEGORY_CONF                5
  45 # ifndef OPENSSL_NO_ENGINE
  46 #  define OSSL_TRACE_CATEGORY_ENGINE_TABLE       6
  47 #  define OSSL_TRACE_CATEGORY_ENGINE_REF_COUNT   7
  48 # endif
  49 # define OSSL_TRACE_CATEGORY_PKCS5V2             8
  50 # define OSSL_TRACE_CATEGORY_PKCS12_KEYGEN       9
  51 # define OSSL_TRACE_CATEGORY_PKCS12_DECRYPT     10
  52 # define OSSL_TRACE_CATEGORY_X509V3_POLICY      11
  53 # define OSSL_TRACE_CATEGORY_BN_CTX             12
  54 # define OSSL_TRACE_CATEGORY_CMP                13
  55 # define OSSL_TRACE_CATEGORY_STORE              14
  56 # define OSSL_TRACE_CATEGORY_NUM                15
  57
  58 /* Returns the trace category number for the given |name| */
  59 int OSSL_trace_get_category_num(const char *name);
  60
  61 /* Returns the trace category name for the given |num| */
  62 const char *OSSL_trace_get_category_name(int num);
  63
  64 /*
  65  * TRACE CONSUMERS
  66  */
  67
  68 /*
  69  * Enables tracing for the given |category| by providing a BIO sink
  70  * as |channel|. If a null pointer is passed as |channel|, an existing
  71  * trace channel is removed and tracing for the category is disabled.
  72  *
  73  * Returns 1 on success and 0 on failure
  74  */
  75 int OSSL_trace_set_channel(int category, BIO* channel);
  76
  77 /*
  78  * Attach a prefix and a suffix to the given |category|, to be printed at the
  79  * beginning and at the end of each trace output group, i.e. when
  80  * OSSL_trace_begin() and OSSL_trace_end() are called.
  81  * If a null pointer is passed as argument, the existing prefix or suffix is
  82  * removed.
  83  *
  84  * They return 1 on success and 0 on failure
  85  */
  86 int OSSL_trace_set_prefix(int category, const char *prefix);
  87 int OSSL_trace_set_suffix(int category, const char *suffix);
  88
  89 /*
  90  * OSSL_trace_cb is the type tracing callback provided by the application.
  91  * It MUST return the number of bytes written, or 0 on error (in other words,
  92  * it can never write zero bytes).
  93  *
  94  * The |buffer| will always contain text, which may consist of several lines.
  95  * The |data| argument points to whatever data was provided by the application
  96  * when registering the tracer function.
  97  *
  98  * The |category| number is given, as well as a |cmd| number, described below.
  99  */
 100 typedef size_t (*OSSL_trace_cb)(const char *buffer, size_t count,
 101                                 int category, int cmd, void *data);
 102 /*
 103  * Possible |cmd| numbers.
 104  */
 105 # define OSSL_TRACE_CTRL_BEGIN  0
 106 # define OSSL_TRACE_CTRL_WRITE  1
 107 # define OSSL_TRACE_CTRL_END    2
 108
 109 /*
 110  * Enables tracing for the given |category| by creating an internal
 111  * trace channel which sends the output to the given |callback|.
 112  * If a null pointer is passed as callback, an existing trace channel
 113  * is removed and tracing for the category is disabled.
 114  *
 115  * NOTE: OSSL_trace_set_channel() and OSSL_trace_set_callback() are mutually
 116  *       exclusive.
 117  *
 118  * Returns 1 on success and 0 on failure
 119  */
 120 int OSSL_trace_set_callback(int category, OSSL_trace_cb callback, void *data);
 121
 122 /*
 123  * TRACE PRODUCERS
 124  */
 125
 126 /*
 127  * Returns 1 if tracing for the specified category is enabled, otherwise 0
 128  */
 129 int OSSL_trace_enabled(int category);
 130
 131 /*
 132  * Wrap a group of tracing output calls.  OSSL_trace_begin() locks tracing and
 133  * returns the trace channel associated with the given category, or NULL if no
 134  * channel is associated with the category.  OSSL_trace_end() unlocks tracing.
 135  *
 136  * Usage:
 137  *
 138  *    BIO *out;
 139  *    if ((out = OSSL_trace_begin(category)) != NULL) {
 140  *        ...
 141  *        BIO_fprintf(out, ...);
 142  *        ...
 143  *        OSSL_trace_end(category, out);
 144  *    }
 145  *
 146  * See also the convenience macros OSSL_TRACE_BEGIN and OSSL_TRACE_END below.
 147  */
 148 BIO *OSSL_trace_begin(int category);
 149 void OSSL_trace_end(int category, BIO *channel);
 150
 151 /*
 152  * OSSL_TRACE* Convenience Macros
 153  */
 154
 155 /*
 156  * When the tracing feature is disabled, these macros are defined to
 157  * produce dead code, which a good compiler should eliminate.
 158  */
 159
 160 /*
 161  * OSSL_TRACE_BEGIN, OSSL_TRACE_END - Define a Trace Group
 162  *
 163  * These two macros can be used to create a block which is executed only
 164  * if the corresponding trace category is enabled. Inside this block, a
 165  * local variable named |trc_out| is defined, which points to the channel
 166  * associated with the given trace category.
 167  *
 168  * Usage: (using 'TLS' as an example category)
 169  *
 170  *     OSSL_TRACE_BEGIN(TLS) {
 171  *
 172  *         BIO_fprintf(trc_out, ... );
 173  *
 174  *     } OSSL_TRACE_END(TLS);
 175  *
 176  *
 177  * This expands to the following code
 178  *
 179  *     do {
 180  *         BIO *trc_out = OSSL_trace_begin(OSSL_TRACE_CATEGORY_TLS);
 181  *         if (trc_out != NULL) {
 182  *             ...
 183  *             BIO_fprintf(trc_out, ...);
 184  *         }
 185  *         OSSL_trace_end(OSSL_TRACE_CATEGORY_TLS, trc_out);
 186  *     } while (0);
 187  *
 188  * The use of the inner '{...}' group and the trailing ';' is enforced
 189  * by the definition of the macros in order to make the code look as much
 190  * like C code as possible.
 191  *
 192  * Before returning from inside the trace block, it is necessary to
 193  * call OSSL_TRACE_CANCEL(category).
 194  */
 195
 196 # ifndef OPENSSL_NO_TRACE
 197
 198 #  define OSSL_TRACE_BEGIN(category) \
 199     do { \
 200         BIO *trc_out = OSSL_trace_begin(OSSL_TRACE_CATEGORY_##category); \
 201  \
 202         if (trc_out != NULL)
 203
 204 #  define OSSL_TRACE_END(category) \
 205         OSSL_trace_end(OSSL_TRACE_CATEGORY_##category, trc_out); \
 206     } while (0)
 207
 208 #  define OSSL_TRACE_CANCEL(category) \
 209         OSSL_trace_end(OSSL_TRACE_CATEGORY_##category, trc_out) \
 210
 211 # else
 212
 213 #  define OSSL_TRACE_BEGIN(category)           \
 214     do {                                        \
 215         BIO *trc_out = NULL;                    \
 216         if (0)
 217
 218 #  define OSSL_TRACE_END(category)             \
 219     } while(0)
 220
 221 #  define OSSL_TRACE_CANCEL(category)          \
 222     ((void)0)
 223
 224 # endif
 225
 226 /*
 227  * OSSL_TRACE_ENABLED() - Check whether tracing is enabled for |category|
 228  *
 229  * Usage:
 230  *
 231  *     if (OSSL_TRACE_ENABLED(TLS)) {
 232  *         ...
 233  *     }
 234  */
 235 # ifndef OPENSSL_NO_TRACE
 236
 237 #  define OSSL_TRACE_ENABLED(category) \
 238     OSSL_trace_enabled(OSSL_TRACE_CATEGORY_##category)
 239
 240 # else
 241
 242 #  define OSSL_TRACE_ENABLED(category) (0)
 243
 244 # endif
 245
 246 /*
 247  * OSSL_TRACE*() - OneShot Trace Macros
 248  *
 249  * These macros are intended to produce a simple printf-style trace output.
 250  * Unfortunately, C90 macros don't support variable arguments, so the
 251  * "vararg" OSSL_TRACEV() macro has a rather weird usage pattern:
 252  *
 253  *    OSSL_TRACEV(category, (trc_out, "format string", ...args...));
 254  *
 255  * Where 'channel' is the literal symbol of this name, not a variable.
 256  * For that reason, it is currently not intended to be used directly,
 257  * but only as helper macro for the other oneshot trace macros
 258  * OSSL_TRACE(), OSSL_TRACE1(), OSSL_TRACE2(), ...
 259  *
 260  * Usage:
 261  *
 262  *    OSSL_TRACE(INIT, "Hello world!\n");
 263  *    OSSL_TRACE1(TLS, "The answer is %d\n", 42);
 264  *    OSSL_TRACE2(TLS, "The ultimate question to answer %d is '%s'\n",
 265  *                42, "What do you get when you multiply six by nine?");
 266  */
 267
 268 # define OSSL_TRACEV(category, args) \
 269     OSSL_TRACE_BEGIN(category) \
 270         BIO_printf args; \
 271     OSSL_TRACE_END(category)
 272
 273 # define OSSL_TRACE(category, text) \
 274     OSSL_TRACEV(category, (trc_out, "%s", text))
 275
 276 # define OSSL_TRACE1(category, format, arg1) \
 277     OSSL_TRACEV(category, (trc_out, format, arg1))
 278 # define OSSL_TRACE2(category, format, arg1, arg2) \
 279     OSSL_TRACEV(category, (trc_out, format, arg1, arg2))
 280 # define OSSL_TRACE3(category, format, arg1, arg2, arg3) \
 281     OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3))
 282 # define OSSL_TRACE4(category, format, arg1, arg2, arg3, arg4) \
 283     OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4))
 284 # define OSSL_TRACE5(category, format, arg1, arg2, arg3, arg4, arg5) \
 285     OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5))
 286 # define OSSL_TRACE6(category, format, arg1, arg2, arg3, arg4, arg5, arg6) \
 287     OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6))
 288 # define OSSL_TRACE7(category, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7) \
 289     OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7))
 290 # define OSSL_TRACE8(category, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \
 291     OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8))
 292 # define OSSL_TRACE9(category, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \
 293     OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9))
 294
 295 # ifdef  __cplusplus
 296 }
 297 # endif
 298
 299 #endif