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