src/basic/log.h

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