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
  63 int log_show_color_from_string(const char *e);
  64 int log_show_location_from_string(const char *e);
  65
  66 LogTarget log_get_target(void) _pure_;
  67 int log_get_max_level_realm(LogRealm realm) _pure_;
  68 #define log_get_max_level()                     \
  69         log_get_max_level_realm(LOG_REALM)
  70
  71 /* Functions below that open and close logs or configure logging based on the
  72  * environment should not be called from library code — this is always a job
  73  * for the application itself.
  74  */
  75
  76 int log_open(void);
  77 void log_close(void);
  78 void log_forget_fds(void);
  79
  80 void log_parse_environment_realm(LogRealm realm);
  81 #define log_parse_environment() \
  82         log_parse_environment_realm(LOG_REALM)
  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,
  93                 const char *extra_field,
  94                 char *buffer);
  95
  96 int log_internal_realm(
  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 #define log_internal(level, ...) \
 104         log_internal_realm(LOG_REALM_PLUS_LEVEL(LOG_REALM, (level)), __VA_ARGS__)
 105
 106 int log_internalv_realm(
 107                 int level,
 108                 int error,
 109                 const char *file,
 110                 int line,
 111                 const char *func,
 112                 const char *format,
 113                 va_list ap) _printf_(6,0);
 114 #define log_internalv(level, ...) \
 115         log_internalv_realm(LOG_REALM_PLUS_LEVEL(LOG_REALM, (level)), __VA_ARGS__)
 116
 117 /* Realm is fixed to LOG_REALM_SYSTEMD for those */
 118 int log_object_internal(
 119                 int level,
 120                 int error,
 121                 const char *file,
 122                 int line,
 123                 const char *func,
 124                 const char *object_field,
 125                 const char *object,
 126                 const char *extra_field,
 127                 const char *extra,
 128                 const char *format, ...) _printf_(10,11);
 129
 130 int log_struct_internal(
 131                 int level,
 132                 int error,
 133                 const char *file,
 134                 int line,
 135                 const char *func,
 136                 const char *format, ...) _printf_(6,0) _sentinel_;
 137
 138 int log_oom_internal(
 139                 LogRealm realm,
 140                 const char *file,
 141                 int line,
 142                 const char *func);
 143
 144 int log_format_iovec(
 145                 struct iovec *iovec,
 146                 size_t iovec_len,
 147                 size_t *n,
 148                 bool newline_separator,
 149                 int error,
 150                 const char *format,
 151                 va_list ap) _printf_(6, 0);
 152
 153 int log_struct_iovec_internal(
 154                 int level,
 155                 int error,
 156                 const char *file,
 157                 int line,
 158                 const char *func,
 159                 const struct iovec *input_iovec,
 160                 size_t n_input_iovec);
 161
 162 /* This modifies the buffer passed! */
 163 int log_dump_internal(
 164                 int level,
 165                 int error,
 166                 const char *file,
 167                 int line,
 168                 const char *func,
 169                 char *buffer);
 170
 171 /* Logging for various assertions */
 172 _noreturn_ void log_assert_failed_realm(
 173                 LogRealm realm,
 174                 const char *text,
 175                 const char *file,
 176                 int line,
 177                 const char *func);
 178 #define log_assert_failed(text, ...) \
 179         log_assert_failed_realm(LOG_REALM, (text), __VA_ARGS__)
 180
 181 _noreturn_ void log_assert_failed_unreachable_realm(
 182                 LogRealm realm,
 183                 const char *text,
 184                 const char *file,
 185                 int line,
 186                 const char *func);
 187 #define log_assert_failed_unreachable(text, ...) \
 188         log_assert_failed_unreachable_realm(LOG_REALM, (text), __VA_ARGS__)
 189
 190 void log_assert_failed_return_realm(
 191                 LogRealm realm,
 192                 const char *text,
 193                 const char *file,
 194                 int line,
 195                 const char *func);
 196 #define log_assert_failed_return(text, ...) \
 197         log_assert_failed_return_realm(LOG_REALM, (text), __VA_ARGS__)
 198
 199 #define log_dispatch(level, error, buffer)                              \
 200         log_dispatch_internal(level, error, __FILE__, __LINE__, __func__, NULL, NULL, NULL, NULL, buffer)
 201
 202 /* Logging with level */
 203 #define log_full_errno_realm(realm, level, error, ...)                  \
 204         ({                                                              \
 205                 int _level = (level), _e = (error), _realm = (realm);   \
 206                 (log_get_max_level_realm(_realm) >= LOG_PRI(_level))    \
 207                         ? log_internal_realm(LOG_REALM_PLUS_LEVEL(_realm, _level), _e, \
 208                                              __FILE__, __LINE__, __func__, __VA_ARGS__) \
 209                         : -ERRNO_VALUE(_e);                             \
 210         })
 211
 212 #define log_full_errno(level, error, ...)                               \
 213         log_full_errno_realm(LOG_REALM, (level), (error), __VA_ARGS__)
 214
 215 #define log_full(level, ...) log_full_errno((level), 0, __VA_ARGS__)
 216
 217 int log_emergency_level(void);
 218
 219 /* Normal logging */
 220 #define log_debug(...)     log_full(LOG_DEBUG,   __VA_ARGS__)
 221 #define log_info(...)      log_full(LOG_INFO,    __VA_ARGS__)
 222 #define log_notice(...)    log_full(LOG_NOTICE,  __VA_ARGS__)
 223 #define log_warning(...)   log_full(LOG_WARNING, __VA_ARGS__)
 224 #define log_error(...)     log_full(LOG_ERR,     __VA_ARGS__)
 225 #define log_emergency(...) log_full(log_emergency_level(), __VA_ARGS__)
 226
 227 /* Logging triggered by an errno-like error */
 228 #define log_debug_errno(error, ...)     log_full_errno(LOG_DEBUG,   error, __VA_ARGS__)
 229 #define log_info_errno(error, ...)      log_full_errno(LOG_INFO,    error, __VA_ARGS__)
 230 #define log_notice_errno(error, ...)    log_full_errno(LOG_NOTICE,  error, __VA_ARGS__)
 231 #define log_warning_errno(error, ...)   log_full_errno(LOG_WARNING, error, __VA_ARGS__)
 232 #define log_error_errno(error, ...)     log_full_errno(LOG_ERR,     error, __VA_ARGS__)
 233 #define log_emergency_errno(error, ...) log_full_errno(log_emergency_level(), error, __VA_ARGS__)
 234
 235 #ifdef LOG_TRACE
 236 #  define log_trace(...) log_debug(__VA_ARGS__)
 237 #else
 238 #  define log_trace(...) do {} while (0)
 239 #endif
 240
 241 /* Structured logging */
 242 #define log_struct_errno(level, error, ...) \
 243         log_struct_internal(LOG_REALM_PLUS_LEVEL(LOG_REALM, level), \
 244                             error, __FILE__, __LINE__, __func__, __VA_ARGS__, NULL)
 245 #define log_struct(level, ...) log_struct_errno(level, 0, __VA_ARGS__)
 246
 247 #define log_struct_iovec_errno(level, error, iovec, n_iovec)            \
 248         log_struct_iovec_internal(LOG_REALM_PLUS_LEVEL(LOG_REALM, level), \
 249                                   error, __FILE__, __LINE__, __func__, iovec, n_iovec)
 250 #define log_struct_iovec(level, iovec, n_iovec) log_struct_iovec_errno(level, 0, iovec, n_iovec)
 251
 252 /* This modifies the buffer passed! */
 253 #define log_dump(level, buffer) \
 254         log_dump_internal(LOG_REALM_PLUS_LEVEL(LOG_REALM, level), \
 255                           0, __FILE__, __LINE__, __func__, buffer)
 256
 257 #define log_oom() log_oom_internal(LOG_REALM, __FILE__, __LINE__, __func__)
 258
 259 bool log_on_console(void) _pure_;
 260
 261 const char *log_target_to_string(LogTarget target) _const_;
 262 LogTarget log_target_from_string(const char *s) _pure_;
 263
 264 /* Helper to prepare various field for structured logging */
 265 #define LOG_MESSAGE(fmt, ...) "MESSAGE=" fmt, ##__VA_ARGS__
 266
 267 void log_received_signal(int level, const struct signalfd_siginfo *si);
 268
 269 /* If turned on, any requests for a log target involving "syslog" will be implicitly upgraded to the equivalent journal target */
 270 void log_set_upgrade_syslog_to_journal(bool b);
 271
 272 /* If turned on, and log_open() is called, we'll not use STDERR_FILENO for logging ever, but rather open /dev/console */
 273 void log_set_always_reopen_console(bool b);
 274
 275 /* If turned on, we'll open the log stream implicitly if needed on each individual log call. This is normally not
 276  * desired as we want to reuse our logging streams. It is useful however  */
 277 void log_set_open_when_needed(bool b);
 278
 279 /* 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
 280  * stderr, the console or kmsg */
 281 void log_set_prohibit_ipc(bool b);
 282
 283 int log_dup_console(void);
 284
 285 int log_syntax_internal(
 286                 const char *unit,
 287                 int level,
 288                 const char *config_file,
 289                 unsigned config_line,
 290                 int error,
 291                 const char *file,
 292                 int line,
 293                 const char *func,
 294                 const char *format, ...) _printf_(9, 10);
 295
 296 int log_syntax_invalid_utf8_internal(
 297                 const char *unit,
 298                 int level,
 299                 const char *config_file,
 300                 unsigned config_line,
 301                 const char *file,
 302                 int line,
 303                 const char *func,
 304                 const char *rvalue);
 305
 306 #define log_syntax(unit, level, config_file, config_line, error, ...)   \
 307         ({                                                              \
 308                 int _level = (level), _e = (error);                     \
 309                 (log_get_max_level() >= LOG_PRI(_level))                \
 310                         ? log_syntax_internal(unit, _level, config_file, config_line, _e, __FILE__, __LINE__, __func__, __VA_ARGS__) \
 311                         : -abs(_e);                                     \
 312         })
 313
 314 #define log_syntax_invalid_utf8(unit, level, config_file, config_line, rvalue) \
 315         ({                                                              \
 316                 int _level = (level);                                   \
 317                 (log_get_max_level() >= LOG_PRI(_level))                \
 318                         ? log_syntax_invalid_utf8_internal(unit, _level, config_file, config_line, __FILE__, __LINE__, __func__, rvalue) \
 319                         : -EINVAL;                                      \
 320         })
 321
 322 #define DEBUG_LOGGING _unlikely_(log_get_max_level() >= LOG_DEBUG)
 323
 324 void log_setup_service(void);