1 files changed, 350 insertions, 0 deletions
diff --git a/src/basic/log.h b/src/basic/log.h
new file mode 100644
index 0000000..a2aae16
--- /dev/null
+++ b/src/basic/log.h
@@ -0,0 +1,350 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <syslog.h>
+
+#include "macro.h"
+
+/* Some structures we reference but don't want to pull in headers for */
+struct iovec;
+struct signalfd_siginfo;
+
+typedef enum LogRealm {
+        LOG_REALM_SYSTEMD,
+        LOG_REALM_UDEV,
+        _LOG_REALM_MAX,
+} LogRealm;
+
+#ifndef LOG_REALM
+#  define LOG_REALM LOG_REALM_SYSTEMD
+#endif
+
+typedef enum LogTarget{
+        LOG_TARGET_CONSOLE,
+        LOG_TARGET_CONSOLE_PREFIXED,
+        LOG_TARGET_KMSG,
+        LOG_TARGET_JOURNAL,
+        LOG_TARGET_JOURNAL_OR_KMSG,
+        LOG_TARGET_SYSLOG,
+        LOG_TARGET_SYSLOG_OR_KMSG,
+        LOG_TARGET_AUTO, /* console if stderr is not journal, JOURNAL_OR_KMSG otherwise */
+        LOG_TARGET_NULL,
+        _LOG_TARGET_MAX,
+        _LOG_TARGET_INVALID = -1
+} LogTarget;
+
+/* Note to readers: << and >> have lower precedence than & and | */
+#define LOG_REALM_PLUS_LEVEL(realm, level)  ((realm) << 10 | (level))
+#define LOG_REALM_REMOVE_LEVEL(realm_level) ((realm_level) >> 10)
+#define SYNTHETIC_ERRNO(num)                (1 << 30 | (num))
+#define IS_SYNTHETIC_ERRNO(val)             ((val) >> 30 & 1)
+#define ERRNO_VALUE(val)                    (abs(val) & 255)
+
+void log_set_target(LogTarget target);
+void log_set_max_level_realm(LogRealm realm, int level);
+#define log_set_max_level(level)                \
+        log_set_max_level_realm(LOG_REALM, (level))
+
+void log_set_facility(int facility);
+
+int log_set_target_from_string(const char *e);
+int log_set_max_level_from_string_realm(LogRealm realm, const char *e);
+#define log_set_max_level_from_string(e)        \
+        log_set_max_level_from_string_realm(LOG_REALM, (e))
+
+void log_show_color(bool b);
+bool log_get_show_color(void) _pure_;
+void log_show_location(bool b);
+bool log_get_show_location(void) _pure_;
+void log_show_time(bool b);
+bool log_get_show_time(void) _pure_;
+void log_show_tid(bool b);
+bool log_get_show_tid(void) _pure_;
+
+int log_show_color_from_string(const char *e);
+int log_show_location_from_string(const char *e);
+int log_show_time_from_string(const char *e);
+int log_show_tid_from_string(const char *e);
+
+LogTarget log_get_target(void) _pure_;
+int log_get_max_level_realm(LogRealm realm) _pure_;
+#define log_get_max_level()                     \
+        log_get_max_level_realm(LOG_REALM)
+
+/* Functions below that open and close logs or configure logging based on the
+ * environment should not be called from library code — this is always a job
+ * for the application itself.
+ */
+
+assert_cc(STRLEN(__FILE__) > STRLEN(RELATIVE_SOURCE_PATH) + 1);
+#define PROJECT_FILE (&__FILE__[STRLEN(RELATIVE_SOURCE_PATH) + 1])
+
+int log_open(void);
+void log_close(void);
+void log_forget_fds(void);
+
+void log_parse_environment_realm(LogRealm realm);
+void log_parse_environment_cli_realm(LogRealm realm);
+#define log_parse_environment() \
+        log_parse_environment_realm(LOG_REALM)
+#define log_parse_environment_cli() \
+        log_parse_environment_cli_realm(LOG_REALM)
+
+int log_dispatch_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *extra,
+                const char *extra_field,
+                char *buffer);
+
+int log_internal_realm(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format, ...) _printf_(6,7);
+#define log_internal(level, ...) \
+        log_internal_realm(LOG_REALM_PLUS_LEVEL(LOG_REALM, (level)), __VA_ARGS__)
+
+int log_internalv_realm(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format,
+                va_list ap) _printf_(6,0);
+#define log_internalv(level, ...) \
+        log_internalv_realm(LOG_REALM_PLUS_LEVEL(LOG_REALM, (level)), __VA_ARGS__)
+
+/* Realm is fixed to LOG_REALM_SYSTEMD for those */
+int log_object_internalv(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *extra_field,
+                const char *extra,
+                const char *format,
+                va_list ap) _printf_(10,0);
+
+int log_object_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *object_field,
+                const char *object,
+                const char *extra_field,
+                const char *extra,
+                const char *format, ...) _printf_(10,11);
+
+int log_struct_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format, ...) _printf_(6,0) _sentinel_;
+
+int log_oom_internal(
+                LogRealm realm,
+                const char *file,
+                int line,
+                const char *func);
+
+int log_format_iovec(
+                struct iovec *iovec,
+                size_t iovec_len,
+                size_t *n,
+                bool newline_separator,
+                int error,
+                const char *format,
+                va_list ap) _printf_(6, 0);
+
+int log_struct_iovec_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const struct iovec *input_iovec,
+                size_t n_input_iovec);
+
+/* This modifies the buffer passed! */
+int log_dump_internal(
+                int level,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                char *buffer);
+
+/* Logging for various assertions */
+_noreturn_ void log_assert_failed_realm(
+                LogRealm realm,
+                const char *text,
+                const char *file,
+                int line,
+                const char *func);
+#define log_assert_failed(text, ...) \
+        log_assert_failed_realm(LOG_REALM, (text), __VA_ARGS__)
+
+_noreturn_ void log_assert_failed_unreachable_realm(
+                LogRealm realm,
+                const char *text,
+                const char *file,
+                int line,
+                const char *func);
+#define log_assert_failed_unreachable(text, ...) \
+        log_assert_failed_unreachable_realm(LOG_REALM, (text), __VA_ARGS__)
+
+void log_assert_failed_return_realm(
+                LogRealm realm,
+                const char *text,
+                const char *file,
+                int line,
+                const char *func);
+#define log_assert_failed_return(text, ...) \
+        log_assert_failed_return_realm(LOG_REALM, (text), __VA_ARGS__)
+
+#define log_dispatch(level, error, buffer)                              \
+        log_dispatch_internal(level, error, PROJECT_FILE, __LINE__, __func__, NULL, NULL, NULL, NULL, buffer)
+
+/* Logging with level */
+#define log_full_errno_realm(realm, level, error, ...)                  \
+        ({                                                              \
+                int _level = (level), _e = (error), _realm = (realm);   \
+                (log_get_max_level_realm(_realm) >= LOG_PRI(_level))    \
+                        ? log_internal_realm(LOG_REALM_PLUS_LEVEL(_realm, _level), _e, \
+                                             PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
+                        : -ERRNO_VALUE(_e);                             \
+        })
+
+#define log_full_errno(level, error, ...)                               \
+        log_full_errno_realm(LOG_REALM, (level), (error), __VA_ARGS__)
+
+#define log_full(level, ...) (void) log_full_errno((level), 0, __VA_ARGS__)
+
+int log_emergency_level(void);
+
+/* Normal logging */
+#define log_debug(...)     log_full_errno(LOG_DEBUG, 0, __VA_ARGS__)
+#define log_info(...)      log_full(LOG_INFO,    __VA_ARGS__)
+#define log_notice(...)    log_full(LOG_NOTICE,  __VA_ARGS__)
+#define log_warning(...)   log_full(LOG_WARNING, __VA_ARGS__)
+#define log_error(...)     log_full(LOG_ERR,     __VA_ARGS__)
+#define log_emergency(...) log_full(log_emergency_level(), __VA_ARGS__)
+
+/* Logging triggered by an errno-like error */
+#define log_debug_errno(error, ...)     log_full_errno(LOG_DEBUG,   error, __VA_ARGS__)
+#define log_info_errno(error, ...)      log_full_errno(LOG_INFO,    error, __VA_ARGS__)
+#define log_notice_errno(error, ...)    log_full_errno(LOG_NOTICE,  error, __VA_ARGS__)
+#define log_warning_errno(error, ...)   log_full_errno(LOG_WARNING, error, __VA_ARGS__)
+#define log_error_errno(error, ...)     log_full_errno(LOG_ERR,     error, __VA_ARGS__)
+#define log_emergency_errno(error, ...) log_full_errno(log_emergency_level(), error, __VA_ARGS__)
+
+#ifdef LOG_TRACE
+#  define log_trace(...) log_debug(__VA_ARGS__)
+#else
+#  define log_trace(...) do {} while (0)
+#endif
+
+/* Structured logging */
+#define log_struct_errno(level, error, ...) \
+        log_struct_internal(LOG_REALM_PLUS_LEVEL(LOG_REALM, level), \
+                            error, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__, NULL)
+#define log_struct(level, ...) log_struct_errno(level, 0, __VA_ARGS__)
+
+#define log_struct_iovec_errno(level, error, iovec, n_iovec)            \
+        log_struct_iovec_internal(LOG_REALM_PLUS_LEVEL(LOG_REALM, level), \
+                                  error, PROJECT_FILE, __LINE__, __func__, iovec, n_iovec)
+#define log_struct_iovec(level, iovec, n_iovec) log_struct_iovec_errno(level, 0, iovec, n_iovec)
+
+/* This modifies the buffer passed! */
+#define log_dump(level, buffer) \
+        log_dump_internal(LOG_REALM_PLUS_LEVEL(LOG_REALM, level), \
+                          0, PROJECT_FILE, __LINE__, __func__, buffer)
+
+#define log_oom() log_oom_internal(LOG_REALM, PROJECT_FILE, __LINE__, __func__)
+
+bool log_on_console(void) _pure_;
+
+const char *log_target_to_string(LogTarget target) _const_;
+LogTarget log_target_from_string(const char *s) _pure_;
+
+/* Helper to prepare various field for structured logging */
+#define LOG_MESSAGE(fmt, ...) "MESSAGE=" fmt, ##__VA_ARGS__
+
+void log_received_signal(int level, const struct signalfd_siginfo *si);
+
+/* If turned on, any requests for a log target involving "syslog" will be implicitly upgraded to the equivalent journal target */
+void log_set_upgrade_syslog_to_journal(bool b);
+
+/* If turned on, and log_open() is called, we'll not use STDERR_FILENO for logging ever, but rather open /dev/console */
+void log_set_always_reopen_console(bool b);
+
+/* If turned on, we'll open the log stream implicitly if needed on each individual log call. This is normally not
+ * desired as we want to reuse our logging streams. It is useful however  */
+void log_set_open_when_needed(bool b);
+
+/* 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
+ * stderr, the console or kmsg */
+void log_set_prohibit_ipc(bool b);
+
+int log_dup_console(void);
+
+int log_syntax_internal(
+                const char *unit,
+                int level,
+                const char *config_file,
+                unsigned config_line,
+                int error,
+                const char *file,
+                int line,
+                const char *func,
+                const char *format, ...) _printf_(9, 10);
+
+int log_syntax_invalid_utf8_internal(
+                const char *unit,
+                int level,
+                const char *config_file,
+                unsigned config_line,
+                const char *file,
+                int line,
+                const char *func,
+                const char *rvalue);
+
+#define log_syntax(unit, level, config_file, config_line, error, ...)   \
+        ({                                                              \
+                int _level = (level), _e = (error);                     \
+                (log_get_max_level() >= LOG_PRI(_level))                \
+                        ? log_syntax_internal(unit, _level, config_file, config_line, _e, PROJECT_FILE, __LINE__, __func__, __VA_ARGS__) \
+                        : -ERRNO_VALUE(_e);                             \
+        })
+
+#define log_syntax_invalid_utf8(unit, level, config_file, config_line, rvalue) \
+        ({                                                              \
+                int _level = (level);                                   \
+                (log_get_max_level() >= LOG_PRI(_level))                \
+                        ? log_syntax_invalid_utf8_internal(unit, _level, config_file, config_line, PROJECT_FILE, __LINE__, __func__, rvalue) \
+                        : -EINVAL;                                      \
+        })
+
+#define DEBUG_LOGGING _unlikely_(log_get_max_level() >= LOG_DEBUG)
+
+void log_setup_service(void);
+void log_setup_cli(void);