src/basic/log.h

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