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 void log_parse_environment_cli_realm(LogRealm realm);
  88 #define log_parse_environment() \
  89         log_parse_environment_realm(LOG_REALM)
  90 #define log_parse_environment_cli() \
  91         log_parse_environment_cli_realm(LOG_REALM)
  92
  93 int log_dispatch_internal(
  94                 int level,
  95                 int error,
  96                 const char *file,
  97                 int line,
  98                 const char *func,
  99                 const char *object_field,
 100                 const char *object,
 101                 const char *extra,
 102                 const char *extra_field,
 103                 char *buffer);
 104
 105 int log_internal_realm(
 106                 int level,
 107                 int error,
 108                 const char *file,
 109                 int line,
 110                 const char *func,
 111                 const char *format, ...) _printf_(6,7);
 112 #define log_internal(level, ...) \
 113         log_internal_realm(LOG_REALM_PLUS_LEVEL(LOG_REALM, (level)), __VA_ARGS__)
 114
 115 int log_internalv_realm(
 116                 int level,
 117                 int error,
 118                 const char *file,
 119                 int line,
 120                 const char *func,
 121                 const char *format,
 122                 va_list ap) _printf_(6,0);
 123 #define log_internalv(level, ...) \
 124         log_internalv_realm(LOG_REALM_PLUS_LEVEL(LOG_REALM, (level)), __VA_ARGS__)
 125
 126 /* Realm is fixed to LOG_REALM_SYSTEMD for those */
 127 int log_object_internalv(
 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,
 138                 va_list ap) _printf_(10,0);
 139
 140 int log_object_internal(
 141                 int level,
 142                 int error,
 143                 const char *file,
 144                 int line,
 145                 const char *func,
 146                 const char *object_field,
 147                 const char *object,
 148                 const char *extra_field,
 149                 const char *extra,
 150                 const char *format, ...) _printf_(10,11);
 151
 152 int log_struct_internal(
 153                 int level,
 154                 int error,
 155                 const char *file,
 156                 int line,
 157                 const char *func,
 158                 const char *format, ...) _printf_(6,0) _sentinel_;
 159
 160 int log_oom_internal(
 161                 LogRealm realm,
 162                 const char *file,
 163                 int line,
 164                 const char *func);
 165
 166 int log_format_iovec(
 167                 struct iovec *iovec,
 168                 size_t iovec_len,
 169                 size_t *n,
 170                 bool newline_separator,
 171                 int error,
 172                 const char *format,
 173                 va_list ap) _printf_(6, 0);
 174
 175 int log_struct_iovec_internal(
 176                 int level,
 177                 int error,
 178                 const char *file,
 179                 int line,
 180                 const char *func,
 181                 const struct iovec *input_iovec,
 182                 size_t n_input_iovec);
 183
 184 /* This modifies the buffer passed! */
 185 int log_dump_internal(
 186                 int level,
 187                 int error,
 188                 const char *file,
 189                 int line,
 190                 const char *func,
 191                 char *buffer);
 192
 193 /* Logging for various assertions */
 194 _noreturn_ void log_assert_failed_realm(
 195                 LogRealm realm,
 196                 const char *text,
 197                 const char *file,
 198                 int line,
 199                 const char *func);
 200 #define log_assert_failed(text, ...) \
 201         log_assert_failed_realm(LOG_REALM, (text), __VA_ARGS__)
 202
 203 _noreturn_ void log_assert_failed_unreachable_realm(
 204                 LogRealm realm,
 205                 const char *text,
 206                 const char *file,
 207                 int line,
 208                 const char *func);
 209 #define log_assert_failed_unreachable(text, ...) \
 210         log_assert_failed_unreachable_realm(LOG_REALM, (text), __VA_ARGS__)
 211
 212 void log_assert_failed_return_realm(
 213                 LogRealm realm,
 214                 const char *text,
 215                 const char *file,
 216                 int line,
 217                 const char *func);
 218 #define log_assert_failed_return(text, ...) \
 219         log_assert_failed_return_realm(LOG_REALM, (text), __VA_ARGS__)
 220
 221 #define log_dispatch(level, error, buffer)                              \
 222         log_dispatch_internal(level, error, PROJECT_FILE, __LINE__, __func__, NULL, NULL, NULL, NULL, buffer)
 223
 224 /* Logging with level */
 225 #define log_full_errno_realm(realm, level, error, ...)                  \
 226         ({                                                              \
 227                 int _level = (level), _e = (error), _realm = (realm);   \
 228                 (log_get_max_level_realm(_realm) >= LOG_PRI(_level))    \
 229                         ? log_internal_realm(LOG_REALM_PLUS_LEVEL(_realm, _level), _e, \
 230                                              PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
 231                         : -ERRNO_VALUE(_e);                             \
 232         })
 233
 234 #define log_full_errno(level, error, ...)                               \
 235         log_full_errno_realm(LOG_REALM, (level), (error), __VA_ARGS__)
 236
 237 #define log_full(level, ...) log_full_errno((level), 0, __VA_ARGS__)
 238
 239 int log_emergency_level(void);
 240
 241 /* Normal logging */
 242 #define log_debug(...)     log_full(LOG_DEBUG,   __VA_ARGS__)
 243 #define log_info(...)      log_full(LOG_INFO,    __VA_ARGS__)
 244 #define log_notice(...)    log_full(LOG_NOTICE,  __VA_ARGS__)
 245 #define log_warning(...)   log_full(LOG_WARNING, __VA_ARGS__)
 246 #define log_error(...)     log_full(LOG_ERR,     __VA_ARGS__)
 247 #define log_emergency(...) log_full(log_emergency_level(), __VA_ARGS__)
 248
 249 /* Logging triggered by an errno-like error */
 250 #define log_debug_errno(error, ...)     log_full_errno(LOG_DEBUG,   error, __VA_ARGS__)
 251 #define log_info_errno(error, ...)      log_full_errno(LOG_INFO,    error, __VA_ARGS__)
 252 #define log_notice_errno(error, ...)    log_full_errno(LOG_NOTICE,  error, __VA_ARGS__)
 253 #define log_warning_errno(error, ...)   log_full_errno(LOG_WARNING, error, __VA_ARGS__)
 254 #define log_error_errno(error, ...)     log_full_errno(LOG_ERR,     error, __VA_ARGS__)
 255 #define log_emergency_errno(error, ...) log_full_errno(log_emergency_level(), error, __VA_ARGS__)
 256
 257 #ifdef LOG_TRACE
 258 #  define log_trace(...) log_debug(__VA_ARGS__)
 259 #else
 260 #  define log_trace(...) do {} while (0)
 261 #endif
 262
 263 /* Structured logging */
 264 #define log_struct_errno(level, error, ...) \
 265         log_struct_internal(LOG_REALM_PLUS_LEVEL(LOG_REALM, level), \
 266                             error, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__, NULL)
 267 #define log_struct(level, ...) log_struct_errno(level, 0, __VA_ARGS__)
 268
 269 #define log_struct_iovec_errno(level, error, iovec, n_iovec)            \
 270         log_struct_iovec_internal(LOG_REALM_PLUS_LEVEL(LOG_REALM, level), \
 271                                   error, PROJECT_FILE, __LINE__, __func__, iovec, n_iovec)
 272 #define log_struct_iovec(level, iovec, n_iovec) log_struct_iovec_errno(level, 0, iovec, n_iovec)
 273
 274 /* This modifies the buffer passed! */
 275 #define log_dump(level, buffer) \
 276         log_dump_internal(LOG_REALM_PLUS_LEVEL(LOG_REALM, level), \
 277                           0, PROJECT_FILE, __LINE__, __func__, buffer)
 278
 279 #define log_oom() log_oom_internal(LOG_REALM, PROJECT_FILE, __LINE__, __func__)
 280
 281 bool log_on_console(void) _pure_;
 282
 283 const char *log_target_to_string(LogTarget target) _const_;
 284 LogTarget log_target_from_string(const char *s) _pure_;
 285
 286 /* Helper to prepare various field for structured logging */
 287 #define LOG_MESSAGE(fmt, ...) "MESSAGE=" fmt, ##__VA_ARGS__
 288
 289 void log_received_signal(int level, const struct signalfd_siginfo *si);
 290
 291 /* If turned on, any requests for a log target involving "syslog" will be implicitly upgraded to the equivalent journal target */
 292 void log_set_upgrade_syslog_to_journal(bool b);
 293
 294 /* If turned on, and log_open() is called, we'll not use STDERR_FILENO for logging ever, but rather open /dev/console */
 295 void log_set_always_reopen_console(bool b);
 296
 297 /* If turned on, we'll open the log stream implicitly if needed on each individual log call. This is normally not
 298  * desired as we want to reuse our logging streams. It is useful however  */
 299 void log_set_open_when_needed(bool b);
 300
 301 /* 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
 302  * stderr, the console or kmsg */
 303 void log_set_prohibit_ipc(bool b);
 304
 305 int log_dup_console(void);
 306
 307 int log_syntax_internal(
 308                 const char *unit,
 309                 int level,
 310                 const char *config_file,
 311                 unsigned config_line,
 312                 int error,
 313                 const char *file,
 314                 int line,
 315                 const char *func,
 316                 const char *format, ...) _printf_(9, 10);
 317
 318 int log_syntax_invalid_utf8_internal(
 319                 const char *unit,
 320                 int level,
 321                 const char *config_file,
 322                 unsigned config_line,
 323                 const char *file,
 324                 int line,
 325                 const char *func,
 326                 const char *rvalue);
 327
 328 #define log_syntax(unit, level, config_file, config_line, error, ...)   \
 329         ({                                                              \
 330                 int _level = (level), _e = (error);                     \
 331                 (log_get_max_level() >= LOG_PRI(_level))                \
 332                         ? log_syntax_internal(unit, _level, config_file, config_line, _e, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
 333                         : -ERRNO_VALUE(_e);                             \
 334         })
 335
 336 #define log_syntax_invalid_utf8(unit, level, config_file, config_line, rvalue) \
 337         ({                                                              \
 338                 int _level = (level);                                   \
 339                 (log_get_max_level() >= LOG_PRI(_level))                \
 340                         ? log_syntax_invalid_utf8_internal(unit, _level, config_file, config_line, PROJECT_FILE, __LINE__, __func__, rvalue) \
 341                         : -EINVAL;                                      \
 342         })
 343
 344 #define DEBUG_LOGGING _unlikely_(log_get_max_level() >= LOG_DEBUG)
 345
 346 void log_setup_service(void);
 347 void log_setup_cli(void);