/* * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef VLOG_H #define VLOG_H 1 #include #include #include #include #include "util.h" #ifdef __cplusplus extern "C" { #endif /* Logging importance levels. * * The following log levels, in descending order of importance, are enabled by * default: * * - EMER: Not currently used. * * - ERR: A high-level operation or a subsystem failed. Attention is * warranted. * * - WARN: A low-level operation failed, but higher-level subsystems may be * able to recover. * * - INFO: Information that may be useful in retrospect when investigating * a problem. * * The lowest log level is not enabled by default: * * - DBG: Information useful only to someone with intricate knowledge of the * system, or that would commonly cause too-voluminous log output. */ #define VLOG_LEVELS \ VLOG_LEVEL(EMER, LOG_ALERT) \ VLOG_LEVEL(ERR, LOG_ERR) \ VLOG_LEVEL(WARN, LOG_WARNING) \ VLOG_LEVEL(INFO, LOG_NOTICE) \ VLOG_LEVEL(DBG, LOG_DEBUG) enum vlog_level { #define VLOG_LEVEL(NAME, SYSLOG_LEVEL) VLL_##NAME, VLOG_LEVELS #undef VLOG_LEVEL VLL_N_LEVELS }; const char *vlog_get_level_name(enum vlog_level); enum vlog_level vlog_get_level_val(const char *name); /* Facilities that we can log to. */ #define VLOG_FACILITIES \ VLOG_FACILITY(SYSLOG, "%05N|%c|%p|%m") \ VLOG_FACILITY(CONSOLE, "%d{%b %d %H:%M:%S}|%05N|%c|%p|%m") \ VLOG_FACILITY(FILE, "%d{%b %d %H:%M:%S}|%05N|%c|%p|%m") enum vlog_facility { #define VLOG_FACILITY(NAME, PATTERN) VLF_##NAME, VLOG_FACILITIES #undef VLOG_FACILITY VLF_N_FACILITIES, VLF_ANY_FACILITY = -1 }; const char *vlog_get_facility_name(enum vlog_facility); enum vlog_facility vlog_get_facility_val(const char *name); /* A log module. */ struct vlog_module { const char *name; /* User-visible name. */ int levels[VLF_N_FACILITIES]; /* Minimum log level for each facility. */ int min_level; /* Minimum log level for any facility. */ }; /* Creates and initializes a global instance of a module named MODULE. */ #if USE_LINKER_SECTIONS #define VLOG_DEFINE_MODULE(MODULE) \ VLOG_DEFINE_MODULE__(MODULE) \ struct vlog_module *vlog_module_ptr_##MODULE \ __attribute__((section("vlog_modules"))) = &VLM_##MODULE #else #define VLOG_DEFINE_MODULE(MODULE) extern struct vlog_module VLM_##MODULE #endif const char *vlog_get_module_name(const struct vlog_module *); struct vlog_module *vlog_module_from_name(const char *name); /* Rate-limiter for log messages. */ struct vlog_rate_limit { /* Configuration settings. */ unsigned int rate; /* Tokens per second. */ unsigned int burst; /* Max cumulative tokens credit. */ /* Current status. */ unsigned int tokens; /* Current number of tokens. */ time_t last_fill; /* Last time tokens added. */ time_t first_dropped; /* Time first message was dropped. */ unsigned int n_dropped; /* Number of messages dropped. */ }; /* Number of tokens to emit a message. We add 'rate' tokens per second, which * is 60 times the unit used for 'rate', thus 60 tokens are required to emit * one message. */ #define VLOG_MSG_TOKENS 60 /* Initializer for a struct vlog_rate_limit, to set up a maximum rate of RATE * messages per minute and a maximum burst size of BURST messages. */ #define VLOG_RATE_LIMIT_INIT(RATE, BURST) \ { \ RATE, /* rate */ \ (MIN(BURST, UINT_MAX / VLOG_MSG_TOKENS) \ * VLOG_MSG_TOKENS), /* burst */ \ 0, /* tokens */ \ 0, /* last_fill */ \ 0, /* first_dropped */ \ 0, /* n_dropped */ \ } /* Configuring how each module logs messages. */ enum vlog_level vlog_get_level(const struct vlog_module *, enum vlog_facility); void vlog_set_levels(struct vlog_module *, enum vlog_facility, enum vlog_level); char *vlog_set_levels_from_string(const char *); char *vlog_get_levels(void); bool vlog_is_enabled(const struct vlog_module *, enum vlog_level); bool vlog_should_drop(const struct vlog_module *, enum vlog_level, struct vlog_rate_limit *); void vlog_set_verbosity(const char *arg); /* Configuring log facilities. */ void vlog_set_pattern(enum vlog_facility, const char *pattern); const char *vlog_get_log_file(void); int vlog_set_log_file(const char *file_name); int vlog_reopen_log_file(void); /* Initialization. */ void vlog_init(void); void vlog_exit(void); /* Functions for actual logging. */ void vlog(const struct vlog_module *, enum vlog_level, const char *format, ...) __attribute__((format(printf, 3, 4))); void vlog_valist(const struct vlog_module *, enum vlog_level, const char *, va_list) __attribute__((format(printf, 3, 0))); void vlog_fatal(const struct vlog_module *, enum vlog_level, const char *format, ...) PRINTF_FORMAT (3, 4) NO_RETURN; void vlog_fatal_valist(const struct vlog_module *, enum vlog_level, const char *, va_list) PRINTF_FORMAT (3, 0) NO_RETURN; void vlog_rate_limit(const struct vlog_module *, enum vlog_level, struct vlog_rate_limit *, const char *, ...) __attribute__((format(printf, 4, 5))); /* Creates and initializes a global instance of a module named MODULE, and * defines a static variable named THIS_MODULE that points to it, for use with * the convenience macros below. */ #define VLOG_DEFINE_THIS_MODULE(MODULE) \ VLOG_DEFINE_MODULE(MODULE); \ static struct vlog_module *const THIS_MODULE = &VLM_##MODULE /* Convenience macros. These assume that THIS_MODULE points to a "struct * vlog_module" for the current module, as set up by e.g. the * VLOG_DEFINE_MODULE macro above. * * Guaranteed to preserve errno. */ #define VLOG_FATAL(...) vlog_fatal(THIS_MODULE, VLL_ERR, __VA_ARGS__) #define VLOG_EMER(...) VLOG(VLL_EMER, __VA_ARGS__) #define VLOG_ERR(...) VLOG(VLL_ERR, __VA_ARGS__) #define VLOG_WARN(...) VLOG(VLL_WARN, __VA_ARGS__) #define VLOG_INFO(...) VLOG(VLL_INFO, __VA_ARGS__) #define VLOG_DBG(...) VLOG(VLL_DBG, __VA_ARGS__) /* More convenience macros, for testing whether a given level is enabled in * THIS_MODULE. When constructing a log message is expensive, this enables it * to be skipped. */ #define VLOG_IS_EMER_ENABLED() true #define VLOG_IS_ERR_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_EMER) #define VLOG_IS_WARN_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_WARN) #define VLOG_IS_INFO_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_INFO) #define VLOG_IS_DBG_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_DBG) /* Convenience macros for rate-limiting. * Guaranteed to preserve errno. */ #define VLOG_ERR_RL(RL, ...) VLOG_RL(RL, VLL_ERR, __VA_ARGS__) #define VLOG_WARN_RL(RL, ...) VLOG_RL(RL, VLL_WARN, __VA_ARGS__) #define VLOG_INFO_RL(RL, ...) VLOG_RL(RL, VLL_INFO, __VA_ARGS__) #define VLOG_DBG_RL(RL, ...) VLOG_RL(RL, VLL_DBG, __VA_ARGS__) #define VLOG_DROP_ERR(RL) vlog_should_drop(THIS_MODULE, VLL_ERR, RL) #define VLOG_DROP_WARN(RL) vlog_should_drop(THIS_MODULE, VLL_WARN, RL) #define VLOG_DROP_INFO(RL) vlog_should_drop(THIS_MODULE, VLL_INFO, RL) #define VLOG_DROP_DBG(RL) vlog_should_drop(THIS_MODULE, VLL_DBG, RL) /* Macros for logging at most once per execution. */ #define VLOG_ERR_ONCE(...) VLOG_ONCE(VLL_ERR, __VA_ARGS__) #define VLOG_WARN_ONCE(...) VLOG_ONCE(VLL_WARN, __VA_ARGS__) #define VLOG_INFO_ONCE(...) VLOG_ONCE(VLL_INFO, __VA_ARGS__) #define VLOG_DBG_ONCE(...) VLOG_ONCE(VLL_DBG, __VA_ARGS__) /* Command line processing. */ #define VLOG_OPTION_ENUMS OPT_LOG_FILE #define VLOG_LONG_OPTIONS \ {"verbose", optional_argument, 0, 'v'}, \ {"log-file", optional_argument, 0, OPT_LOG_FILE} #define VLOG_OPTION_HANDLERS \ case 'v': \ vlog_set_verbosity(optarg); \ break; \ case OPT_LOG_FILE: \ vlog_set_log_file(optarg); \ break; void vlog_usage(void); /* Implementation details. */ #define VLOG(LEVEL, ...) \ do { \ if (THIS_MODULE->min_level >= LEVEL) { \ vlog(THIS_MODULE, LEVEL, __VA_ARGS__); \ } \ } while (0) #define VLOG_RL(RL, LEVEL, ...) \ do { \ if (THIS_MODULE->min_level >= LEVEL) { \ vlog_rate_limit(THIS_MODULE, LEVEL, RL, __VA_ARGS__); \ } \ } while (0) #define VLOG_ONCE(LEVEL, ...) \ do { \ static bool already_logged; \ if (!already_logged) { \ already_logged = true; \ vlog(THIS_MODULE, LEVEL, __VA_ARGS__); \ } \ } while (0) #define VLOG_DEFINE_MODULE__(MODULE) \ struct vlog_module VLM_##MODULE = \ { \ #MODULE, /* name */ \ { [ 0 ... VLF_N_FACILITIES - 1] = VLL_INFO }, /* levels */ \ VLL_INFO, /* min_level */ \ }; #ifdef __cplusplus } #endif #endif /* vlog.h */