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 DECLARE_STRING_TABLE_LOOKUP(log_target, LogTarget);
  44 void log_set_target(LogTarget target);
  45 void log_set_target_and_open(LogTarget target);
  46 int log_set_target_from_string(const char *e);
  47 LogTarget log_get_target(void) _pure_;
  48 void log_settle_target(void);
  49
  50 int log_set_max_level(int level);
  51 int log_set_max_level_from_string(const char *e);
  52 int log_get_max_level(void) _pure_;
  53 int log_get_target_max_level(LogTarget target);
  54 int log_max_levels_to_string(int level, char **ret);
  55
  56 void log_set_facility(int facility);
  57
  58 void log_show_color(bool b);
  59 bool log_get_show_color(void) _pure_;
  60 void log_show_location(bool b);
  61 bool log_get_show_location(void) _pure_;
  62 void log_show_time(bool b);
  63 bool log_get_show_time(void) _pure_;
  64 void log_show_tid(bool b);
  65 bool log_get_show_tid(void) _pure_;
  66
  67 int log_show_color_from_string(const char *e);
  68 int log_show_location_from_string(const char *e);
  69 int log_show_time_from_string(const char *e);
  70 int log_show_tid_from_string(const char *e);
  71
  72 /* Functions below that open and close logs or configure logging based on the
  73  * environment should not be called from library code — this is always a job
  74  * for the application itself. */
  75
  76 bool stderr_is_journal(void);
  77 int log_open(void);
  78 void log_close(void);
  79 void log_forget_fds(void);
  80
  81 void log_parse_environment_variables(void);
  82 void log_parse_environment(void);
  83
  84 int log_dispatch_internal(
  85                 int level,
  86                 int error,
  87                 const char *file,
  88                 int line,
  89                 const char *func,
  90                 const char *object_field,
  91                 const char *object,
  92                 const char *extra_field,
  93                 const char *extra,
  94                 char *buffer);
  95
  96 int log_internal(
  97                 int level,
  98                 int error,
  99                 const char *file,
 100                 int line,
 101                 const char *func,
 102                 const char *format, ...) _printf_(6,7);
 103
 104 int log_internalv(
 105                 int level,
 106                 int error,
 107                 const char *file,
 108                 int line,
 109                 const char *func,
 110                 const char *format,
 111                 va_list ap) _printf_(6,0);
 112
 113 int log_object_internalv(
 114                 int level,
 115                 int error,
 116                 const char *file,
 117                 int line,
 118                 const char *func,
 119                 const char *object_field,
 120                 const char *object,
 121                 const char *extra_field,
 122                 const char *extra,
 123                 const char *format,
 124                 va_list ap) _printf_(10,0);
 125
 126 int log_object_internal(
 127                 int level,
 128                 int error,
 129                 const char *file,
 130                 int line,
 131                 const char *func,
 132                 const char *object_field,
 133                 const char *object,
 134                 const char *extra_field,
 135                 const char *extra,
 136                 const char *format, ...) _printf_(10,11);
 137
 138 int log_struct_internal(
 139                 int level,
 140                 int error,
 141                 const char *file,
 142                 int line,
 143                 const char *func,
 144                 const char *format, ...) _sentinel_;
 145
 146 int log_oom_internal(
 147                 int level,
 148                 const char *file,
 149                 int line,
 150                 const char *func);
 151
 152 int log_format_iovec(
 153                 struct iovec *iovec,
 154                 size_t iovec_len,
 155                 size_t *n,
 156                 bool newline_separator,
 157                 int error,
 158                 const char *format,
 159                 va_list ap) _printf_(6, 0);
 160
 161 int log_struct_iovec_internal(
 162                 int level,
 163                 int error,
 164                 const char *file,
 165                 int line,
 166                 const char *func,
 167                 const struct iovec *input_iovec,
 168                 size_t n_input_iovec);
 169
 170 /* This modifies the buffer passed! */
 171 int log_dump_internal(
 172                 int level,
 173                 int error,
 174                 const char *file,
 175                 int line,
 176                 const char *func,
 177                 char *buffer);
 178
 179 #define log_dispatch(level, error, buffer)                              \
 180         log_dispatch_internal(level, error, PROJECT_FILE, __LINE__, __func__, NULL, NULL, NULL, NULL, buffer)
 181
 182 /* Logging with level */
 183 #define log_full_errno_zerook(level, error, ...)                        \
 184         ({                                                              \
 185                 int _level = (level), _e = (error);                     \
 186                 _e = (log_get_max_level() >= LOG_PRI(_level))           \
 187                         ? log_internal(_level, _e, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
 188                         : -ERRNO_VALUE(_e);                             \
 189                 _e < 0 ? _e : -ESTRPIPE;                                \
 190         })
 191
 192 #if BUILD_MODE_DEVELOPER && !defined(TEST_CODE)
 193 #  define ASSERT_NON_ZERO(x) assert((x) != 0)
 194 #  define ASSERT_UNDERFLOW(x) assert((x) >= INT_MIN)
 195 #else
 196 #  define ASSERT_NON_ZERO(x)
 197 #  define ASSERT_UNDERFLOW(x)
 198 #endif
 199
 200 /* We often call log macros with ssize_t instead of int, so check for underflows,
 201  * as ssize_t is not guaranteed to be the same as int, and we usually do
 202  * 'return log_errno...' from functions that return 'int' */
 203 #define log_full_errno(level, error, ...)                               \
 204         ({                                                              \
 205                 int64_t _error = (error);                               \
 206                 ASSERT_UNDERFLOW(_error);                               \
 207                 ASSERT_NON_ZERO(_error);                                \
 208                 log_full_errno_zerook(level, (int)_error, __VA_ARGS__); \
 209         })
 210
 211 #define log_full(level, fmt, ...)                                      \
 212         ({                                                             \
 213                 if (BUILD_MODE_DEVELOPER)                              \
 214                         assert(!strstr(fmt, "%m"));                    \
 215                 (void) log_full_errno_zerook(level, 0, fmt, ##__VA_ARGS__); \
 216         })
 217
 218 int log_emergency_level(void);
 219
 220 /* Normal logging */
 221 #define log_debug(...)     log_full(LOG_DEBUG,   __VA_ARGS__)
 222 #define log_info(...)      log_full(LOG_INFO,    __VA_ARGS__)
 223 #define log_notice(...)    log_full(LOG_NOTICE,  __VA_ARGS__)
 224 #define log_warning(...)   log_full(LOG_WARNING, __VA_ARGS__)
 225 #define log_error(...)     log_full(LOG_ERR,     __VA_ARGS__)
 226 #define log_emergency(...) log_full(log_emergency_level(), __VA_ARGS__)
 227
 228 /* Logging triggered by an errno-like error */
 229 #define log_debug_errno(error, ...)     log_full_errno(LOG_DEBUG,   error, __VA_ARGS__)
 230 #define log_info_errno(error, ...)      log_full_errno(LOG_INFO,    error, __VA_ARGS__)
 231 #define log_notice_errno(error, ...)    log_full_errno(LOG_NOTICE,  error, __VA_ARGS__)
 232 #define log_warning_errno(error, ...)   log_full_errno(LOG_WARNING, error, __VA_ARGS__)
 233 #define log_error_errno(error, ...)     log_full_errno(LOG_ERR,     error, __VA_ARGS__)
 234 #define log_emergency_errno(error, ...) log_full_errno(log_emergency_level(), error, __VA_ARGS__)
 235
 236 /* This logs at the specified level the first time it is called, and then
 237  * logs at debug. If the specified level is debug, this logs only the first
 238  * time it is called. */
 239 #define log_once(level, ...)                                             \
 240         ({                                                               \
 241                 if (ONCE)                                                \
 242                         log_full(level, __VA_ARGS__);                    \
 243                 else if (LOG_PRI(level) != LOG_DEBUG)                    \
 244                         log_debug(__VA_ARGS__);                          \
 245         })
 246
 247 #define log_once_errno(level, error, ...)                                \
 248         ({                                                               \
 249                 int _err = (error);                                      \
 250                 if (ONCE)                                                \
 251                         _err = log_full_errno(level, _err, __VA_ARGS__); \
 252                 else if (LOG_PRI(level) != LOG_DEBUG)                    \
 253                         _err = log_debug_errno(_err, __VA_ARGS__);       \
 254                 else                                                     \
 255                         _err = -ERRNO_VALUE(_err);                       \
 256                 _err;                                                    \
 257         })
 258
 259 #if LOG_TRACE
 260 #  define log_trace(...)          log_debug(__VA_ARGS__)
 261 #  define log_trace_errno(...)    log_debug_errno(__VA_ARGS__)
 262 #else
 263 #  define log_trace(...)          do {} while (0)
 264 #  define log_trace_errno(e, ...) (-ERRNO_VALUE(e))
 265 #endif
 266
 267 /* Structured logging */
 268 #define log_struct_errno(level, error, ...)                             \
 269         log_struct_internal(level, error, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__, NULL)
 270 #define log_struct(level, ...) log_struct_errno(level, 0, __VA_ARGS__)
 271
 272 #define log_struct_iovec_errno(level, error, iovec, n_iovec)            \
 273         log_struct_iovec_internal(level, error, PROJECT_FILE, __LINE__, __func__, iovec, n_iovec)
 274 #define log_struct_iovec(level, iovec, n_iovec) log_struct_iovec_errno(level, 0, iovec, n_iovec)
 275
 276 /* Like log_struct(), but with log_once() semantics */
 277 #define log_struct_once(level, ...)                                     \
 278         ({                                                              \
 279                 if (ONCE)                                               \
 280                         log_struct(level, __VA_ARGS__);                 \
 281                 else if (LOG_PRI(level) != LOG_DEBUG)                   \
 282                         log_struct(LOG_DEBUG, __VA_ARGS__);             \
 283         })
 284
 285 /* This modifies the buffer passed! */
 286 #define log_dump(level, buffer)                                         \
 287         log_dump_internal(level, 0, PROJECT_FILE, __LINE__, __func__, buffer)
 288
 289 #define log_oom_full(level) log_oom_internal(level, PROJECT_FILE, __LINE__, __func__)
 290 #define log_oom()           log_oom_full(LOG_ERR)
 291 #define log_oom_debug()     log_oom_full(LOG_DEBUG)
 292 #define log_oom_warning()   log_oom_full(LOG_WARNING)
 293
 294 bool log_on_console(void) _pure_;
 295
 296 /* Helper to wrap the main message in structured logging. The macro doesn't do much,
 297  * except to provide visual grouping of the format string and its arguments. */
 298 #ifdef __COVERITY__
 299 /* Coverity does not like the concatenation of multiple formats and arguments. Let's replace each format
 300  * string with a dummy string. The validity of the formats is hopefully checked by other CIs. */
 301 #  define LOG_ITEM(fmt, ...)    "dummy", NULL, ##__VA_ARGS__
 302 #elif LOG_MESSAGE_VERIFICATION
 303 /* Do a fake formatting of the message string to let the scanner verify the arguments against the format
 304  * message. The variable will never be set to true, but we don't tell the compiler that :) */
 305 extern bool _log_message_dummy;
 306 #  define LOG_ITEM(fmt, ...) "%.0d" fmt, (_log_message_dummy && printf(fmt, ##__VA_ARGS__)), ##__VA_ARGS__
 307 #else
 308 #  define LOG_ITEM(fmt, ...) fmt, ##__VA_ARGS__
 309 #endif
 310
 311 #define LOG_MESSAGE(fmt, ...) LOG_ITEM("MESSAGE=" fmt, ##__VA_ARGS__)
 312 #define LOG_MESSAGE_ID(id)    LOG_ITEM("MESSAGE_ID=" id)
 313
 314 void log_received_signal(int level, const struct signalfd_siginfo *si);
 315
 316 /* If turned on, any requests for a log target involving "syslog" will be implicitly upgraded to the equivalent journal target */
 317 void log_set_upgrade_syslog_to_journal(bool b);
 318
 319 /* If turned on, and log_open() is called, we'll not use STDERR_FILENO for logging ever, but rather open /dev/console */
 320 void log_set_always_reopen_console(bool b);
 321
 322 /* If turned on, we'll open the log stream implicitly if needed on each individual log call. This is normally not
 323  * desired as we want to reuse our logging streams. It is useful however  */
 324 void log_set_open_when_needed(bool b);
 325
 326 /* 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
 327  * stderr, the console or kmsg */
 328 void log_set_prohibit_ipc(bool b);
 329
 330 int log_dup_console(void);
 331
 332 int log_syntax_internal(
 333                 const char *unit,
 334                 int level,
 335                 const char *config_file,
 336                 unsigned config_line,
 337                 int error,
 338                 const char *file,
 339                 int line,
 340                 const char *func,
 341                 const char *format, ...) _printf_(9, 10);
 342
 343 int log_syntax_invalid_utf8_internal(
 344                 const char *unit,
 345                 int level,
 346                 const char *config_file,
 347                 unsigned config_line,
 348                 const char *file,
 349                 int line,
 350                 const char *func,
 351                 const char *rvalue);
 352
 353 int log_syntax_parse_error_internal(
 354                 const char *unit,
 355                 const char *config_file,
 356                 unsigned config_line,
 357                 int error,
 358                 bool critical, /* When true, propagate the passed error, otherwise this always returns 0. */
 359                 const char *file,
 360                 int line,
 361                 const char *func,
 362                 const char *lvalue,
 363                 const char *rvalue);
 364
 365 #define log_syntax(unit, level, config_file, config_line, error, ...)   \
 366         ({                                                              \
 367                 int _level = (level), _e = (error);                     \
 368                 (log_get_max_level() >= LOG_PRI(_level))                \
 369                         ? log_syntax_internal(unit, _level, config_file, config_line, _e, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
 370                         : -ERRNO_VALUE(_e);                             \
 371         })
 372
 373 #define log_syntax_invalid_utf8(unit, level, config_file, config_line, rvalue) \
 374         ({                                                              \
 375                 int _level = (level);                                   \
 376                 (log_get_max_level() >= LOG_PRI(_level))                \
 377                         ? log_syntax_invalid_utf8_internal(unit, _level, config_file, config_line, PROJECT_FILE, __LINE__, __func__, rvalue) \
 378                         : -EINVAL;                                      \
 379         })
 380
 381 #define log_syntax_parse_error_full(unit, config_file, config_line, error, critical, lvalue, rvalue) \
 382         log_syntax_parse_error_internal(unit, config_file, config_line, error, critical, PROJECT_FILE, __LINE__, __func__, lvalue, rvalue)
 383
 384 #define log_syntax_parse_error(unit, config_file, config_line, error, lvalue, rvalue) \
 385         log_syntax_parse_error_full(unit, config_file, config_line, error, /* critical= */ false, lvalue, rvalue)
 386
 387 #define DEBUG_LOGGING _unlikely_(log_get_max_level() >= LOG_DEBUG)
 388
 389 void log_setup(void);
 390
 391 const char* _log_set_prefix(const char *prefix, bool force);
 392
 393 void log_prefix_swap(const char **prefix);
 394 static inline const char* _log_unset_prefixp(const char **p) {
 395         assert(p);
 396         _log_set_prefix(*p, true);
 397         return NULL;
 398 }
 399
 400 #define LOG_SET_PREFIX(prefix) \
 401         _cleanup_(_log_unset_prefixp) _unused_ const char *CONCATENATE(_cleanup_log_unset_prefix_, UNIQ) = _log_set_prefix(prefix, false);