src/basic/log.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include <stdio.h>
   5 #include <string.h>
   6 #include <syslog.h>
   7
   8 #include "basic-forward.h"
   9
  10 typedef enum LogTarget{
  11         LOG_TARGET_CONSOLE,
  12         LOG_TARGET_KMSG,
  13         LOG_TARGET_JOURNAL,
  14         LOG_TARGET_SYSLOG,
  15         LOG_TARGET_CONSOLE_PREFIXED,
  16         LOG_TARGET_JOURNAL_OR_KMSG,
  17         LOG_TARGET_SYSLOG_OR_KMSG,
  18         LOG_TARGET_AUTO, /* console if stderr is not journal, JOURNAL_OR_KMSG otherwise */
  19         LOG_TARGET_NULL,
  20         _LOG_TARGET_SINGLE_MAX = LOG_TARGET_SYSLOG + 1,
  21         _LOG_TARGET_MAX = LOG_TARGET_NULL + 1,
  22         _LOG_TARGET_INVALID = -EINVAL,
  23 } LogTarget;
  24
  25 /* This log level disables logging completely. It can only be passed to log_set_max_level() and cannot be
  26  * used as a regular log level. */
  27 #define LOG_NULL (LOG_EMERG - 1)
  28 assert_cc(LOG_NULL == -1);
  29
  30 #define SYNTHETIC_ERRNO(num)                (ABS(num) | (1 << 30))
  31 #define IS_SYNTHETIC_ERRNO(val)             (((val) >> 30) == 1)
  32 #define ERRNO_VALUE(val)                    (ABS(val) & ~(1 << 30))
  33
  34 /* The callback function to be invoked when syntax warnings are seen
  35  * in the unit files. */
  36 typedef void (*log_syntax_callback_t)(const char *unit, int level, void *userdata);
  37 void set_log_syntax_callback(log_syntax_callback_t cb, void *userdata);
  38
  39 static inline void clear_log_syntax_callback(dummy_t *dummy) {
  40           set_log_syntax_callback(/* cb= */ NULL, /* userdata= */ NULL);
  41 }
  42
  43 const char* log_target_to_string(LogTarget target) _const_;
  44 LogTarget log_target_from_string(const char *s) _pure_;
  45 void log_set_target(LogTarget target);
  46 void log_set_target_and_open(LogTarget target);
  47 int log_set_target_from_string(const char *e);
  48 LogTarget log_get_target(void) _pure_;
  49 void log_settle_target(void);
  50
  51 int log_set_max_level(int level);
  52 int log_set_max_level_from_string(const char *e);
  53 int log_get_max_level(void) _pure_;
  54 int log_get_target_max_level(LogTarget target);
  55 int log_max_levels_to_string(int level, char **ret);
  56
  57 void log_set_facility(int facility);
  58
  59 void log_show_color(bool b);
  60 bool log_get_show_color(void) _pure_;
  61 void log_show_location(bool b);
  62 bool log_get_show_location(void) _pure_;
  63 void log_show_time(bool b);
  64 bool log_get_show_time(void) _pure_;
  65 void log_show_tid(bool b);
  66 bool log_get_show_tid(void) _pure_;
  67
  68 int log_show_color_from_string(const char *e);
  69 int log_show_location_from_string(const char *e);
  70 int log_show_time_from_string(const char *e);
  71 int log_show_tid_from_string(const char *e);
  72
  73 /* Functions below that open and close logs or configure logging based on the
  74  * environment should not be called from library code — this is always a job
  75  * for the application itself. */
  76
  77 bool stderr_is_journal(void);
  78 int log_open(void);
  79 void log_close(void);
  80 void log_forget_fds(void);
  81
  82 void log_parse_environment_variables(void);
  83 void log_parse_environment(void);
  84
  85 int log_dispatch_internal(
  86                 int level,
  87                 int error,
  88                 const char *file,
  89                 int line,
  90                 const char *func,
  91                 const char *object_field,
  92                 const char *object,
  93                 const char *extra_field,
  94                 const char *extra,
  95                 char *buffer);
  96
  97 int log_internal(
  98                 int level,
  99                 int error,
 100                 const char *file,
 101                 int line,
 102                 const char *func,
 103                 const char *format, ...) _printf_(6,7);
 104
 105 int log_internalv(
 106                 int level,
 107                 int error,
 108                 const char *file,
 109                 int line,
 110                 const char *func,
 111                 const char *format,
 112                 va_list ap) _printf_(6,0);
 113
 114 int log_object_internalv(
 115                 int level,
 116                 int error,
 117                 const char *file,
 118                 int line,
 119                 const char *func,
 120                 const char *object_field,
 121                 const char *object,
 122                 const char *extra_field,
 123                 const char *extra,
 124                 const char *format,
 125                 va_list ap) _printf_(10,0);
 126
 127 int log_object_internal(
 128                 int level,
 129                 int error,
 130                 const char *file,
 131                 int line,
 132                 const char *func,
 133                 const char *object_field,
 134                 const char *object,
 135                 const char *extra_field,
 136                 const char *extra,
 137                 const char *format, ...) _printf_(10,11);
 138
 139 int log_struct_internal(
 140                 int level,
 141                 int error,
 142                 const char *file,
 143                 int line,
 144                 const char *func,
 145                 const char *format, ...) _sentinel_;
 146
 147 int log_oom_internal(
 148                 int level,
 149                 const char *file,
 150                 int line,
 151                 const char *func);
 152
 153 int log_format_iovec(
 154                 struct iovec *iovec,
 155                 size_t iovec_len,
 156                 size_t *n,
 157                 bool newline_separator,
 158                 int error,
 159                 const char *format,
 160                 va_list ap) _printf_(6, 0);
 161
 162 int log_struct_iovec_internal(
 163                 int level,
 164                 int error,
 165                 const char *file,
 166                 int line,
 167                 const char *func,
 168                 const struct iovec *input_iovec,
 169                 size_t n_input_iovec);
 170
 171 /* This modifies the buffer passed! */
 172 int log_dump_internal(
 173                 int level,
 174                 int error,
 175                 const char *file,
 176                 int line,
 177                 const char *func,
 178                 char *buffer);
 179
 180 #define log_dispatch(level, error, buffer)                              \
 181         log_dispatch_internal(level, error, PROJECT_FILE, __LINE__, __func__, NULL, NULL, NULL, NULL, buffer)
 182
 183 /* Logging with level */
 184 #define log_full_errno_zerook(level, error, ...)                        \
 185         ({                                                              \
 186                 int _level = (level), _e = (error);                     \
 187                 _e = (log_get_max_level() >= LOG_PRI(_level))           \
 188                         ? log_internal(_level, _e, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
 189                         : -ERRNO_VALUE(_e);                             \
 190                 _e < 0 ? _e : -ESTRPIPE;                                \
 191         })
 192
 193 #if BUILD_MODE_DEVELOPER && !defined(TEST_CODE)
 194 #  define ASSERT_NON_ZERO(x) assert((x) != 0)
 195 #  define ASSERT_UNDERFLOW(x) assert((x) >= INT_MIN)
 196 #else
 197 #  define ASSERT_NON_ZERO(x)
 198 #  define ASSERT_UNDERFLOW(x)
 199 #endif
 200
 201 /* We often call log macros with ssize_t instead of int, so check for underflows,
 202  * as ssize_t is not guaranteed to be the same as int, and we usually do
 203  * 'return log_errno...' from functions that return 'int' */
 204 #define log_full_errno(level, error, ...)                               \
 205         ({                                                              \
 206                 int64_t _error = (error);                               \
 207                 ASSERT_UNDERFLOW(_error);                               \
 208                 ASSERT_NON_ZERO(_error);                                \
 209                 log_full_errno_zerook(level, (int)_error, __VA_ARGS__); \
 210         })
 211
 212 #define log_full(level, fmt, ...)                                      \
 213         ({                                                             \
 214                 if (BUILD_MODE_DEVELOPER)                              \
 215                         assert(!strstr(fmt, "%m"));                    \
 216                 (void) log_full_errno_zerook(level, 0, fmt, ##__VA_ARGS__); \
 217         })
 218
 219 int log_emergency_level(void);
 220
 221 /* Normal logging */
 222 #define log_debug(...)     log_full(LOG_DEBUG,   __VA_ARGS__)
 223 #define log_info(...)      log_full(LOG_INFO,    __VA_ARGS__)
 224 #define log_notice(...)    log_full(LOG_NOTICE,  __VA_ARGS__)
 225 #define log_warning(...)   log_full(LOG_WARNING, __VA_ARGS__)
 226 #define log_error(...)     log_full(LOG_ERR,     __VA_ARGS__)
 227 #define log_emergency(...) log_full(log_emergency_level(), __VA_ARGS__)
 228
 229 /* Logging triggered by an errno-like error */
 230 #define log_debug_errno(error, ...)     log_full_errno(LOG_DEBUG,   error, __VA_ARGS__)
 231 #define log_info_errno(error, ...)      log_full_errno(LOG_INFO,    error, __VA_ARGS__)
 232 #define log_notice_errno(error, ...)    log_full_errno(LOG_NOTICE,  error, __VA_ARGS__)
 233 #define log_warning_errno(error, ...)   log_full_errno(LOG_WARNING, error, __VA_ARGS__)
 234 #define log_error_errno(error, ...)     log_full_errno(LOG_ERR,     error, __VA_ARGS__)
 235 #define log_emergency_errno(error, ...) log_full_errno(log_emergency_level(), error, __VA_ARGS__)
 236
 237 /* This logs at the specified level the first time it is called, and then
 238  * logs at debug. If the specified level is debug, this logs only the first
 239  * time it is called. */
 240 #define log_once(level, ...)                                             \
 241         ({                                                               \
 242                 if (ONCE)                                                \
 243                         log_full(level, __VA_ARGS__);                    \
 244                 else if (LOG_PRI(level) != LOG_DEBUG)                    \
 245                         log_debug(__VA_ARGS__);                          \
 246         })
 247
 248 #define log_once_errno(level, error, ...)                                \
 249         ({                                                               \
 250                 int _err = (error);                                      \
 251                 if (ONCE)                                                \
 252                         _err = log_full_errno(level, _err, __VA_ARGS__); \
 253                 else if (LOG_PRI(level) != LOG_DEBUG)                    \
 254                         _err = log_debug_errno(_err, __VA_ARGS__);       \
 255                 else                                                     \
 256                         _err = -ERRNO_VALUE(_err);                       \
 257                 _err;                                                    \
 258         })
 259
 260 #if LOG_TRACE
 261 #  define log_trace(...)          log_debug(__VA_ARGS__)
 262 #  define log_trace_errno(...)    log_debug_errno(__VA_ARGS__)
 263 #else
 264 #  define log_trace(...)          do {} while (0)
 265 #  define log_trace_errno(e, ...) (-ERRNO_VALUE(e))
 266 #endif
 267
 268 /* Structured logging */
 269 #define log_struct_errno(level, error, ...)                             \
 270         log_struct_internal(level, error, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__, NULL)
 271 #define log_struct(level, ...) log_struct_errno(level, 0, __VA_ARGS__)
 272
 273 #define log_struct_iovec_errno(level, error, iovec, n_iovec)            \
 274         log_struct_iovec_internal(level, error, PROJECT_FILE, __LINE__, __func__, iovec, n_iovec)
 275 #define log_struct_iovec(level, iovec, n_iovec) log_struct_iovec_errno(level, 0, iovec, n_iovec)
 276
 277 /* This modifies the buffer passed! */
 278 #define log_dump(level, buffer)                                         \
 279         log_dump_internal(level, 0, PROJECT_FILE, __LINE__, __func__, buffer)
 280
 281 #define log_oom_full(level) log_oom_internal(level, PROJECT_FILE, __LINE__, __func__)
 282 #define log_oom()           log_oom_full(LOG_ERR)
 283 #define log_oom_debug()     log_oom_full(LOG_DEBUG)
 284 #define log_oom_warning()   log_oom_full(LOG_WARNING)
 285
 286 bool log_on_console(void) _pure_;
 287
 288 /* Helper to wrap the main message in structured logging. The macro doesn't do much,
 289  * except to provide visual grouping of the format string and its arguments. */
 290 #if LOG_MESSAGE_VERIFICATION || defined(__COVERITY__)
 291 /* Do a fake formatting of the message string to let the scanner verify the arguments against the format
 292  * message. The variable will never be set to true, but we don't tell the compiler that :) */
 293 extern bool _log_message_dummy;
 294 #  define LOG_ITEM(fmt, ...) "%.0d" fmt, (_log_message_dummy && printf(fmt, ##__VA_ARGS__)), ##__VA_ARGS__
 295 #  define LOG_MESSAGE(fmt, ...) LOG_ITEM("MESSAGE=" fmt, ##__VA_ARGS__)
 296 #else
 297 #  define LOG_ITEM(fmt, ...) fmt, ##__VA_ARGS__
 298 #  define LOG_MESSAGE(fmt, ...) "MESSAGE=" fmt, ##__VA_ARGS__
 299 #endif
 300
 301 #define LOG_MESSAGE_ID(id) LOG_ITEM("MESSAGE_ID=" id)
 302
 303 void log_received_signal(int level, const struct signalfd_siginfo *si);
 304
 305 /* If turned on, any requests for a log target involving "syslog" will be implicitly upgraded to the equivalent journal target */
 306 void log_set_upgrade_syslog_to_journal(bool b);
 307
 308 /* If turned on, and log_open() is called, we'll not use STDERR_FILENO for logging ever, but rather open /dev/console */
 309 void log_set_always_reopen_console(bool b);
 310
 311 /* If turned on, we'll open the log stream implicitly if needed on each individual log call. This is normally not
 312  * desired as we want to reuse our logging streams. It is useful however  */
 313 void log_set_open_when_needed(bool b);
 314
 315 /* If turned on, then we'll never use IPC-based logging, i.e. never log to syslog or the journal. We'll only log to
 316  * stderr, the console or kmsg */
 317 void log_set_prohibit_ipc(bool b);
 318
 319 int log_dup_console(void);
 320
 321 int log_syntax_internal(
 322                 const char *unit,
 323                 int level,
 324                 const char *config_file,
 325                 unsigned config_line,
 326                 int error,
 327                 const char *file,
 328                 int line,
 329                 const char *func,
 330                 const char *format, ...) _printf_(9, 10);
 331
 332 int log_syntax_invalid_utf8_internal(
 333                 const char *unit,
 334                 int level,
 335                 const char *config_file,
 336                 unsigned config_line,
 337                 const char *file,
 338                 int line,
 339                 const char *func,
 340                 const char *rvalue);
 341
 342 int log_syntax_parse_error_internal(
 343                 const char *unit,
 344                 const char *config_file,
 345                 unsigned config_line,
 346                 int error,
 347                 bool critical, /* When true, propagate the passed error, otherwise this always returns 0. */
 348                 const char *file,
 349                 int line,
 350                 const char *func,
 351                 const char *lvalue,
 352                 const char *rvalue);
 353
 354 #define log_syntax(unit, level, config_file, config_line, error, ...)   \
 355         ({                                                              \
 356                 int _level = (level), _e = (error);                     \
 357                 (log_get_max_level() >= LOG_PRI(_level))                \
 358                         ? log_syntax_internal(unit, _level, config_file, config_line, _e, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
 359                         : -ERRNO_VALUE(_e);                             \
 360         })
 361
 362 #define log_syntax_invalid_utf8(unit, level, config_file, config_line, rvalue) \
 363         ({                                                              \
 364                 int _level = (level);                                   \
 365                 (log_get_max_level() >= LOG_PRI(_level))                \
 366                         ? log_syntax_invalid_utf8_internal(unit, _level, config_file, config_line, PROJECT_FILE, __LINE__, __func__, rvalue) \
 367                         : -EINVAL;                                      \
 368         })
 369
 370 #define log_syntax_parse_error_full(unit, config_file, config_line, error, critical, lvalue, rvalue) \
 371         log_syntax_parse_error_internal(unit, config_file, config_line, error, critical, PROJECT_FILE, __LINE__, __func__, lvalue, rvalue)
 372
 373 #define log_syntax_parse_error(unit, config_file, config_line, error, lvalue, rvalue) \
 374         log_syntax_parse_error_full(unit, config_file, config_line, error, /* critical = */ false, lvalue, rvalue)
 375
 376 #define DEBUG_LOGGING _unlikely_(log_get_max_level() >= LOG_DEBUG)
 377
 378 void log_setup(void);
 379
 380 const char* _log_set_prefix(const char *prefix, bool force);
 381 static inline const char* _log_unset_prefixp(const char **p) {
 382         assert(p);
 383         _log_set_prefix(*p, true);
 384         return NULL;
 385 }
 386
 387 #define LOG_SET_PREFIX(prefix) \
 388         _cleanup_(_log_unset_prefixp) _unused_ const char *CONCATENATE(_cleanup_log_unset_prefix_, UNIQ) = _log_set_prefix(prefix, false);