include/openssl/trace.h

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