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