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 <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 LogTarget{
  16         LOG_TARGET_CONSOLE,
  17         LOG_TARGET_CONSOLE_PREFIXED,
  18         LOG_TARGET_KMSG,
  19         LOG_TARGET_JOURNAL,
  20         LOG_TARGET_JOURNAL_OR_KMSG,
  21         LOG_TARGET_SYSLOG,
  22         LOG_TARGET_SYSLOG_OR_KMSG,
  23         LOG_TARGET_AUTO, /* console if stderr is not journal, JOURNAL_OR_KMSG otherwise */
  24         LOG_TARGET_NULL,
  25         _LOG_TARGET_MAX,
  26         _LOG_TARGET_INVALID = -EINVAL,
  27 } LogTarget;
  28
  29 /* Note to readers: << and >> have lower precedence than & and | */
  30 #define SYNTHETIC_ERRNO(num)                (1 << 30 | (num))
  31 #define IS_SYNTHETIC_ERRNO(val)             ((val) >> 30 & 1)
  32 #define ERRNO_VALUE(val)                    (abs(val) & 255)
  33
  34 const char *log_target_to_string(LogTarget target) _const_;
  35 LogTarget log_target_from_string(const char *s) _pure_;
  36 void log_set_target(LogTarget target);
  37 int log_set_target_from_string(const char *e);
  38 LogTarget log_get_target(void) _pure_;
  39
  40 void log_set_max_level(int level);
  41 int log_set_max_level_from_string(const char *e);
  42 int log_get_max_level(void) _pure_;
  43
  44 void log_set_facility(int facility);
  45
  46 void log_show_color(bool b);
  47 bool log_get_show_color(void) _pure_;
  48 void log_show_location(bool b);
  49 bool log_get_show_location(void) _pure_;
  50 void log_show_time(bool b);
  51 bool log_get_show_time(void) _pure_;
  52 void log_show_tid(bool b);
  53 bool log_get_show_tid(void) _pure_;
  54
  55 int log_show_color_from_string(const char *e);
  56 int log_show_location_from_string(const char *e);
  57 int log_show_time_from_string(const char *e);
  58 int log_show_tid_from_string(const char *e);
  59
  60 /* Functions below that open and close logs or configure logging based on the
  61  * environment should not be called from library code — this is always a job
  62  * for the application itself. */
  63
  64 assert_cc(STRLEN(__FILE__) > STRLEN(RELATIVE_SOURCE_PATH) + 1);
  65 #define PROJECT_FILE (&__FILE__[STRLEN(RELATIVE_SOURCE_PATH) + 1])
  66
  67 int log_open(void);
  68 void log_close(void);
  69 void log_forget_fds(void);
  70
  71 void log_parse_environment(void);
  72
  73 int log_dispatch_internal(
  74                 int level,
  75                 int error,
  76                 const char *file,
  77                 int line,
  78                 const char *func,
  79                 const char *object_field,
  80                 const char *object,
  81                 const char *extra,
  82                 const char *extra_field,
  83                 char *buffer);
  84
  85 int log_internal(
  86                 int level,
  87                 int error,
  88                 const char *file,
  89                 int line,
  90                 const char *func,
  91                 const char *format, ...) _printf_(6,7);
  92
  93 int log_internalv(
  94                 int level,
  95                 int error,
  96                 const char *file,
  97                 int line,
  98                 const char *func,
  99                 const char *format,
 100                 va_list ap) _printf_(6,0);
 101
 102 int log_object_internalv(
 103                 int level,
 104                 int error,
 105                 const char *file,
 106                 int line,
 107                 const char *func,
 108                 const char *object_field,
 109                 const char *object,
 110                 const char *extra_field,
 111                 const char *extra,
 112                 const char *format,
 113                 va_list ap) _printf_(10,0);
 114
 115 int log_object_internal(
 116                 int level,
 117                 int error,
 118                 const char *file,
 119                 int line,
 120                 const char *func,
 121                 const char *object_field,
 122                 const char *object,
 123                 const char *extra_field,
 124                 const char *extra,
 125                 const char *format, ...) _printf_(10,11);
 126
 127 int log_struct_internal(
 128                 int level,
 129                 int error,
 130                 const char *file,
 131                 int line,
 132                 const char *func,
 133                 const char *format, ...) _printf_(6,0) _sentinel_;
 134
 135 int log_oom_internal(
 136                 int level,
 137                 const char *file,
 138                 int line,
 139                 const char *func);
 140
 141 int log_format_iovec(
 142                 struct iovec *iovec,
 143                 size_t iovec_len,
 144                 size_t *n,
 145                 bool newline_separator,
 146                 int error,
 147                 const char *format,
 148                 va_list ap) _printf_(6, 0);
 149
 150 int log_struct_iovec_internal(
 151                 int level,
 152                 int error,
 153                 const char *file,
 154                 int line,
 155                 const char *func,
 156                 const struct iovec *input_iovec,
 157                 size_t n_input_iovec);
 158
 159 /* This modifies the buffer passed! */
 160 int log_dump_internal(
 161                 int level,
 162                 int error,
 163                 const char *file,
 164                 int line,
 165                 const char *func,
 166                 char *buffer);
 167
 168 /* Logging for various assertions */
 169 _noreturn_ void log_assert_failed(
 170                 const char *text,
 171                 const char *file,
 172                 int line,
 173                 const char *func);
 174
 175 _noreturn_ void log_assert_failed_unreachable(
 176                 const char *text,
 177                 const char *file,
 178                 int line,
 179                 const char *func);
 180
 181 void log_assert_failed_return(
 182                 const char *text,
 183                 const char *file,
 184                 int line,
 185                 const char *func);
 186
 187 #define log_dispatch(level, error, buffer)                              \
 188         log_dispatch_internal(level, error, PROJECT_FILE, __LINE__, __func__, NULL, NULL, NULL, NULL, buffer)
 189
 190 /* Logging with level */
 191 #define log_full_errno(level, error, ...)                               \
 192         ({                                                              \
 193                 int _level = (level), _e = (error);                     \
 194                 (log_get_max_level() >= LOG_PRI(_level))                \
 195                         ? log_internal(_level, _e, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
 196                         : -ERRNO_VALUE(_e);                             \
 197         })
 198
 199 #define log_full(level, ...) (void) log_full_errno((level), 0, __VA_ARGS__)
 200
 201 int log_emergency_level(void);
 202
 203 /* Normal logging */
 204 #define log_debug(...)     log_full_errno(LOG_DEBUG, 0, __VA_ARGS__)
 205 #define log_info(...)      log_full(LOG_INFO,    __VA_ARGS__)
 206 #define log_notice(...)    log_full(LOG_NOTICE,  __VA_ARGS__)
 207 #define log_warning(...)   log_full(LOG_WARNING, __VA_ARGS__)
 208 #define log_error(...)     log_full(LOG_ERR,     __VA_ARGS__)
 209 #define log_emergency(...) log_full(log_emergency_level(), __VA_ARGS__)
 210
 211 /* Logging triggered by an errno-like error */
 212 #define log_debug_errno(error, ...)     log_full_errno(LOG_DEBUG,   error, __VA_ARGS__)
 213 #define log_info_errno(error, ...)      log_full_errno(LOG_INFO,    error, __VA_ARGS__)
 214 #define log_notice_errno(error, ...)    log_full_errno(LOG_NOTICE,  error, __VA_ARGS__)
 215 #define log_warning_errno(error, ...)   log_full_errno(LOG_WARNING, error, __VA_ARGS__)
 216 #define log_error_errno(error, ...)     log_full_errno(LOG_ERR,     error, __VA_ARGS__)
 217 #define log_emergency_errno(error, ...) log_full_errno(log_emergency_level(), error, __VA_ARGS__)
 218
 219 #ifdef LOG_TRACE
 220 #  define log_trace(...) log_debug(__VA_ARGS__)
 221 #else
 222 #  define log_trace(...) do {} while (0)
 223 #endif
 224
 225 /* Structured logging */
 226 #define log_struct_errno(level, error, ...)                             \
 227         log_struct_internal(level, error, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__, NULL)
 228 #define log_struct(level, ...) log_struct_errno(level, 0, __VA_ARGS__)
 229
 230 #define log_struct_iovec_errno(level, error, iovec, n_iovec)            \
 231         log_struct_iovec_internal(level, error, PROJECT_FILE, __LINE__, __func__, iovec, n_iovec)
 232 #define log_struct_iovec(level, iovec, n_iovec) log_struct_iovec_errno(level, 0, iovec, n_iovec)
 233
 234 /* This modifies the buffer passed! */
 235 #define log_dump(level, buffer)                                         \
 236         log_dump_internal(level, 0, PROJECT_FILE, __LINE__, __func__, buffer)
 237
 238 #define log_oom() log_oom_internal(LOG_ERR, PROJECT_FILE, __LINE__, __func__)
 239 #define log_oom_debug() log_oom_internal(LOG_DEBUG, PROJECT_FILE, __LINE__, __func__)
 240
 241 bool log_on_console(void) _pure_;
 242
 243 /* Helper to prepare various field for structured logging */
 244 #define LOG_MESSAGE(fmt, ...) "MESSAGE=" fmt, ##__VA_ARGS__
 245
 246 void log_received_signal(int level, const struct signalfd_siginfo *si);
 247
 248 /* If turned on, any requests for a log target involving "syslog" will be implicitly upgraded to the equivalent journal target */
 249 void log_set_upgrade_syslog_to_journal(bool b);
 250
 251 /* If turned on, and log_open() is called, we'll not use STDERR_FILENO for logging ever, but rather open /dev/console */
 252 void log_set_always_reopen_console(bool b);
 253
 254 /* If turned on, we'll open the log stream implicitly if needed on each individual log call. This is normally not
 255  * desired as we want to reuse our logging streams. It is useful however  */
 256 void log_set_open_when_needed(bool b);
 257
 258 /* 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
 259  * stderr, the console or kmsg */
 260 void log_set_prohibit_ipc(bool b);
 261
 262 int log_dup_console(void);
 263
 264 int log_syntax_internal(
 265                 const char *unit,
 266                 int level,
 267                 const char *config_file,
 268                 unsigned config_line,
 269                 int error,
 270                 const char *file,
 271                 int line,
 272                 const char *func,
 273                 const char *format, ...) _printf_(9, 10);
 274
 275 int log_syntax_invalid_utf8_internal(
 276                 const char *unit,
 277                 int level,
 278                 const char *config_file,
 279                 unsigned config_line,
 280                 const char *file,
 281                 int line,
 282                 const char *func,
 283                 const char *rvalue);
 284
 285 #define log_syntax(unit, level, config_file, config_line, error, ...)   \
 286         ({                                                              \
 287                 int _level = (level), _e = (error);                     \
 288                 (log_get_max_level() >= LOG_PRI(_level))                \
 289                         ? log_syntax_internal(unit, _level, config_file, config_line, _e, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
 290                         : -ERRNO_VALUE(_e);                             \
 291         })
 292
 293 #define log_syntax_invalid_utf8(unit, level, config_file, config_line, rvalue) \
 294         ({                                                              \
 295                 int _level = (level);                                   \
 296                 (log_get_max_level() >= LOG_PRI(_level))                \
 297                         ? log_syntax_invalid_utf8_internal(unit, _level, config_file, config_line, PROJECT_FILE, __LINE__, __func__, rvalue) \
 298                         : -EINVAL;                                      \
 299         })
 300
 301 #define DEBUG_LOGGING _unlikely_(log_get_max_level() >= LOG_DEBUG)
 302
 303 void log_setup(void);