2 * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
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
15 # include <openssl/bio.h>
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
33 * The ANY category is used as a fallback category.
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_NUM 6
43 /* Returns the trace category number for the given |name| */
44 int OSSL_trace_get_category_num(const char *name);
46 /* Returns the trace category name for the given |num| */
47 const char *OSSL_trace_get_category_name(int num);
54 * Enables tracing for the given |category| by providing a BIO sink
55 * as |channel|. If a null pointer is passed as |channel|, an existing
56 * trace channel is removed and tracing for the category is disabled.
58 * Returns 1 on success and 0 on failure
60 int OSSL_trace_set_channel(int category, BIO* channel);
63 * Attach a prefix and a suffix to the given |category|, to be printed at the
64 * beginning and at the end of each trace output group, i.e. when
65 * OSSL_trace_begin() and OSSL_trace_end() are called.
66 * If a null pointer is passed as argument, the existing prefix or suffix is
69 * They return 1 on success and 0 on failure
71 int OSSL_trace_set_prefix(int category, const char *prefix);
72 int OSSL_trace_set_suffix(int category, const char *suffix);
75 * OSSL_trace_cb is the type tracing callback provided by the application.
76 * It MUST return the number of bytes written, or 0 on error (in other words,
77 * it can never write zero bytes).
79 * The |buffer| will always contain text, which may consist of several lines.
80 * The |data| argument points to whatever data was provided by the application
81 * when registering the tracer function.
83 * The |category| number is given, as well as a |cmd| number, described below.
85 typedef size_t (*OSSL_trace_cb)(const char *buffer, size_t count,
86 int category, int cmd, void *data);
88 * Possible |cmd| numbers.
90 # define OSSL_TRACE_CTRL_BEGIN 0
91 # define OSSL_TRACE_CTRL_DURING 1
92 # define OSSL_TRACE_CTRL_END 2
95 * Enables tracing for the given |category| by creating an internal
96 * trace channel which sends the output to the given |callback|.
97 * If a null pointer is passed as callback, an existing trace channel
98 * is removed and tracing for the category is disabled.
100 * NOTE: OSSL_trace_set_channel() and OSSL_trace_set_callback() are mutually
103 * Returns 1 on success and 0 on failure
105 int OSSL_trace_set_callback(int category, OSSL_trace_cb callback, void *data);
112 * Returns 1 if tracing for the specified category is enabled, otherwise 0
114 int OSSL_trace_enabled(int category);
117 * Wrap a group of tracing output calls. OSSL_trace_begin() locks tracing and
118 * returns the trace channel associated with the given category, or NULL if no
119 * channel is associated with the category. OSSL_trace_end() unlocks tracing.
124 * if ((out = OSSL_trace_begin(category)) != NULL) {
126 * BIO_fprintf(out, ...);
128 * OSSL_trace_end(category, out);
131 * See also the convenience macros OSSL_TRACE_BEGIN and OSSL_TRACE_END below.
133 BIO *OSSL_trace_begin(int category);
134 void OSSL_trace_end(int category, BIO *channel);
137 * OSSL_TRACE* Convenience Macros
141 * When the tracing feature is disabled, these macros are defined to
142 * produce dead code, which a good compiler should eliminate.
146 * OSSL_TRACE_BEGIN, OSSL_TRACE_END - Define a Trace Group
148 * These two macros can be used to create a block which is executed only
149 * if the corresponding trace category is enabled. Inside this block, a
150 * local variable named |trc_out| is defined, which points to the channel
151 * associated with the given trace category.
153 * Usage: (using 'TLS' as an example category)
155 * OSSL_TRACE_BEGIN(TLS) {
157 * BIO_fprintf(trc_out, ... );
159 * } OSSL_TRACE_END(TLS);
162 * This expands to the following code
165 * BIO *trc_out = OSSL_trace_begin(OSSL_TRACE_CATEGORY_TLS);
166 * if (trc_out != NULL) {
168 * BIO_fprintf(trc_out, ...);
170 * OSSL_trace_end(OSSL_TRACE_CATEGORY_TLS, trc_out);
173 * The use of the inner '{...}' group and the trailing ';' is enforced
174 * by the definition of the macros in order to make the code look as much
175 * like C code as possible.
177 * Before returning from inside the trace block, it is necessary to
178 * call OSSL_TRACE_CANCEL(category).
181 # ifndef OPENSSL_NO_TRACE
183 # define OSSL_TRACE_BEGIN(category) \
185 BIO *trc_out = OSSL_trace_begin(OSSL_TRACE_CATEGORY_##category); \
189 # define OSSL_TRACE_END(category) \
190 OSSL_trace_end(OSSL_TRACE_CATEGORY_##category, trc_out); \
193 # define OSSL_TRACE_CANCEL(category) \
194 OSSL_trace_end(OSSL_TRACE_CATEGORY_##category, trc_out) \
198 # define OSSL_TRACE_BEGIN(category) \
200 BIO *trc_out = NULL; \
203 # define OSSL_TRACE_END(category) \
206 # define OSSL_TRACE_CANCEL(category) \
212 * OSSL_TRACE_ENABLED() - Check whether tracing is enabled for |category|
216 * if (OSSL_TRACE_ENABLED(TLS)) {
220 # ifndef OPENSSL_NO_TRACE
222 # define OSSL_TRACE_ENABLED(category) \
223 OSSL_trace_enabled(OSSL_TRACE_CATEGORY_##category)
227 # define OSSL_TRACE_ENABLED(category) (0)
232 * OSSL_TRACE*() - OneShot Trace Macros
234 * These macros are intended to produce a simple printf-style trace output.
235 * Unfortunately, C90 macros don't support variable arguments, so the
236 * "vararg" OSSL_TRACEV() macro has a rather weird usage pattern:
238 * OSSL_TRACEV(category, (trc_out, "format string", ...args...));
240 * Where 'channel' is the literal symbol of this name, not a variable.
241 * For that reason, it is currently not intended to be used directly,
242 * but only as helper macro for the other oneshot trace macros
243 * OSSL_TRACE(), OSSL_TRACE1(), OSSL_TRACE2(), ...
247 * OSSL_TRACE(INIT, "Hello world!\n");
248 * OSSL_TRACE1(TLS, "The answer is %d\n", 42);
249 * OSSL_TRACE2(TLS, "The ultimate question to answer %d is '%s'\n",
250 * 42, "What do you get when you multiply six by nine?");
253 # define OSSL_TRACEV(category, args) \
254 OSSL_TRACE_BEGIN(category) \
256 OSSL_TRACE_END(category)
258 # define OSSL_TRACE(category, text) \
259 OSSL_TRACEV(category, (trc_out, "%s", text))
261 # define OSSL_TRACE1(category, format, arg1) \
262 OSSL_TRACEV(category, (trc_out, format, arg1))
263 # define OSSL_TRACE2(category, format, arg1, arg2) \
264 OSSL_TRACEV(category, (trc_out, format, arg1, arg2))
265 # define OSSL_TRACE3(category, format, arg1, arg2, arg3) \
266 OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3))
267 # define OSSL_TRACE4(category, format, arg1, arg2, arg3, arg4) \
268 OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4))
269 # define OSSL_TRACE5(category, format, arg1, arg2, arg3, arg4, arg5) \
270 OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5))
271 # define OSSL_TRACE6(category, format, arg1, arg2, arg3, arg4, arg5, arg6) \
272 OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6))
273 # define OSSL_TRACE7(category, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7) \
274 OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7))
275 # define OSSL_TRACE8(category, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \
276 OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8))
277 # define OSSL_TRACE9(category, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8) \
278 OSSL_TRACEV(category, (trc_out, format, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8, arg9))