2 * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
31 /* Logging severity levels.
33 * A logging severity level of OFF suppresses logging. Messages at the
34 * following log levels, in descending order of importance, are enabled by
37 * - EMER: The process is aborting due to unrecoverable failure.
39 * - ERR: A high-level operation or a subsystem failed. Attention is
42 * - WARN: A low-level operation failed, but higher-level subsystems may be
45 * - INFO: Information that may be useful in retrospect when investigating
48 * The lowest log level is not enabled by default:
50 * - DBG: Information useful only to someone with intricate knowledge of the
51 * system, or that would commonly cause too-voluminous log output.
54 VLOG_LEVEL(OFF, LOG_ALERT) \
55 VLOG_LEVEL(EMER, LOG_ALERT) \
56 VLOG_LEVEL(ERR, LOG_ERR) \
57 VLOG_LEVEL(WARN, LOG_WARNING) \
58 VLOG_LEVEL(INFO, LOG_NOTICE) \
59 VLOG_LEVEL(DBG, LOG_DEBUG)
61 #define VLOG_LEVEL(NAME, SYSLOG_LEVEL) VLL_##NAME,
67 const char *vlog_get_level_name(enum vlog_level);
68 enum vlog_level vlog_get_level_val(const char *name);
70 /* Facilities that we can log to. */
71 #define VLOG_FACILITIES \
72 VLOG_FACILITY(SYSLOG, "%05N|%c|%p|%m") \
73 VLOG_FACILITY(CONSOLE, "%d{%b %d %H:%M:%S}|%05N|%c|%p|%m") \
74 VLOG_FACILITY(FILE, "%d{%b %d %H:%M:%S}|%05N|%c|%p|%m")
76 #define VLOG_FACILITY(NAME, PATTERN) VLF_##NAME,
83 const char *vlog_get_facility_name(enum vlog_facility);
84 enum vlog_facility vlog_get_facility_val(const char *name);
88 const char *name; /* User-visible name. */
89 int levels[VLF_N_FACILITIES]; /* Minimum log level for each facility. */
90 int min_level; /* Minimum log level for any facility. */
93 /* Creates and initializes a global instance of a module named MODULE. */
94 #if USE_LINKER_SECTIONS
95 #define VLOG_DEFINE_MODULE(MODULE) \
96 VLOG_DEFINE_MODULE__(MODULE) \
97 extern struct vlog_module *vlog_module_ptr_##MODULE; \
98 struct vlog_module *vlog_module_ptr_##MODULE \
99 __attribute__((section("vlog_modules"))) = &VLM_##MODULE
101 #define VLOG_DEFINE_MODULE(MODULE) extern struct vlog_module VLM_##MODULE
104 const char *vlog_get_module_name(const struct vlog_module *);
105 struct vlog_module *vlog_module_from_name(const char *name);
107 /* Rate-limiter for log messages. */
108 struct vlog_rate_limit {
109 /* Configuration settings. */
110 unsigned int rate; /* Tokens per second. */
111 unsigned int burst; /* Max cumulative tokens credit. */
113 /* Current status. */
114 unsigned int tokens; /* Current number of tokens. */
115 time_t last_fill; /* Last time tokens added. */
116 time_t first_dropped; /* Time first message was dropped. */
117 time_t last_dropped; /* Time of most recent message drop. */
118 unsigned int n_dropped; /* Number of messages dropped. */
121 /* Number of tokens to emit a message. We add 'rate' tokens per second, which
122 * is 60 times the unit used for 'rate', thus 60 tokens are required to emit
124 #define VLOG_MSG_TOKENS 60
126 /* Initializer for a struct vlog_rate_limit, to set up a maximum rate of RATE
127 * messages per minute and a maximum burst size of BURST messages. */
128 #define VLOG_RATE_LIMIT_INIT(RATE, BURST) \
131 (MIN(BURST, UINT_MAX / VLOG_MSG_TOKENS) \
132 * VLOG_MSG_TOKENS), /* burst */ \
135 0, /* first_dropped */ \
136 0, /* last_dropped */ \
140 /* Configuring how each module logs messages. */
141 enum vlog_level vlog_get_level(const struct vlog_module *, enum vlog_facility);
142 void vlog_set_levels(struct vlog_module *,
143 enum vlog_facility, enum vlog_level);
144 char *vlog_set_levels_from_string(const char *);
145 char *vlog_get_levels(void);
146 bool vlog_is_enabled(const struct vlog_module *, enum vlog_level);
147 bool vlog_should_drop(const struct vlog_module *, enum vlog_level,
148 struct vlog_rate_limit *);
149 void vlog_set_verbosity(const char *arg);
151 /* Configuring log facilities. */
152 void vlog_set_pattern(enum vlog_facility, const char *pattern);
153 const char *vlog_get_log_file(void);
154 int vlog_set_log_file(const char *file_name);
155 int vlog_reopen_log_file(void);
157 /* Initialization. */
158 void vlog_init(void);
159 void vlog_exit(void);
161 /* Functions for actual logging. */
162 void vlog(const struct vlog_module *, enum vlog_level, const char *format, ...)
163 PRINTF_FORMAT (3, 4);
164 void vlog_valist(const struct vlog_module *, enum vlog_level,
165 const char *, va_list)
166 PRINTF_FORMAT (3, 0);
168 void vlog_fatal(const struct vlog_module *, const char *format, ...)
169 PRINTF_FORMAT (2, 3) NO_RETURN;
170 void vlog_fatal_valist(const struct vlog_module *, const char *format, va_list)
171 PRINTF_FORMAT (2, 0) NO_RETURN;
173 void vlog_rate_limit(const struct vlog_module *, enum vlog_level,
174 struct vlog_rate_limit *, const char *, ...)
175 PRINTF_FORMAT (4, 5);
177 /* Creates and initializes a global instance of a module named MODULE, and
178 * defines a static variable named THIS_MODULE that points to it, for use with
179 * the convenience macros below. */
180 #define VLOG_DEFINE_THIS_MODULE(MODULE) \
181 VLOG_DEFINE_MODULE(MODULE); \
182 static struct vlog_module *const THIS_MODULE = &VLM_##MODULE
184 /* Convenience macros. These assume that THIS_MODULE points to a "struct
185 * vlog_module" for the current module, as set up by e.g. the
186 * VLOG_DEFINE_MODULE macro above.
188 * Guaranteed to preserve errno.
190 #define VLOG_FATAL(...) vlog_fatal(THIS_MODULE, __VA_ARGS__)
191 #define VLOG_EMER(...) VLOG(VLL_EMER, __VA_ARGS__)
192 #define VLOG_ERR(...) VLOG(VLL_ERR, __VA_ARGS__)
193 #define VLOG_WARN(...) VLOG(VLL_WARN, __VA_ARGS__)
194 #define VLOG_INFO(...) VLOG(VLL_INFO, __VA_ARGS__)
195 #define VLOG_DBG(...) VLOG(VLL_DBG, __VA_ARGS__)
197 /* More convenience macros, for testing whether a given level is enabled in
198 * THIS_MODULE. When constructing a log message is expensive, this enables it
200 #define VLOG_IS_ERR_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_ERR)
201 #define VLOG_IS_WARN_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_WARN)
202 #define VLOG_IS_INFO_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_INFO)
203 #define VLOG_IS_DBG_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_DBG)
205 /* Convenience macros for rate-limiting.
206 * Guaranteed to preserve errno.
208 #define VLOG_ERR_RL(RL, ...) VLOG_RL(RL, VLL_ERR, __VA_ARGS__)
209 #define VLOG_WARN_RL(RL, ...) VLOG_RL(RL, VLL_WARN, __VA_ARGS__)
210 #define VLOG_INFO_RL(RL, ...) VLOG_RL(RL, VLL_INFO, __VA_ARGS__)
211 #define VLOG_DBG_RL(RL, ...) VLOG_RL(RL, VLL_DBG, __VA_ARGS__)
213 #define VLOG_DROP_ERR(RL) vlog_should_drop(THIS_MODULE, VLL_ERR, RL)
214 #define VLOG_DROP_WARN(RL) vlog_should_drop(THIS_MODULE, VLL_WARN, RL)
215 #define VLOG_DROP_INFO(RL) vlog_should_drop(THIS_MODULE, VLL_INFO, RL)
216 #define VLOG_DROP_DBG(RL) vlog_should_drop(THIS_MODULE, VLL_DBG, RL)
218 /* Macros for logging at most once per execution. */
219 #define VLOG_ERR_ONCE(...) VLOG_ONCE(VLL_ERR, __VA_ARGS__)
220 #define VLOG_WARN_ONCE(...) VLOG_ONCE(VLL_WARN, __VA_ARGS__)
221 #define VLOG_INFO_ONCE(...) VLOG_ONCE(VLL_INFO, __VA_ARGS__)
222 #define VLOG_DBG_ONCE(...) VLOG_ONCE(VLL_DBG, __VA_ARGS__)
224 /* Command line processing. */
225 #define VLOG_OPTION_ENUMS OPT_LOG_FILE
226 #define VLOG_LONG_OPTIONS \
227 {"verbose", optional_argument, NULL, 'v'}, \
228 {"log-file", optional_argument, NULL, OPT_LOG_FILE}
229 #define VLOG_OPTION_HANDLERS \
231 vlog_set_verbosity(optarg); \
234 vlog_set_log_file(optarg); \
236 void vlog_usage(void);
238 /* Implementation details. */
239 #define VLOG(LEVEL, ...) \
241 enum vlog_level level__ = LEVEL; \
242 if (THIS_MODULE->min_level >= level__) { \
243 vlog(THIS_MODULE, level__, __VA_ARGS__); \
246 #define VLOG_RL(RL, LEVEL, ...) \
248 enum vlog_level level__ = LEVEL; \
249 if (THIS_MODULE->min_level >= level__) { \
250 vlog_rate_limit(THIS_MODULE, level__, RL, __VA_ARGS__); \
253 #define VLOG_ONCE(LEVEL, ...) \
255 static bool already_logged; \
256 if (!already_logged) { \
257 already_logged = true; \
258 vlog(THIS_MODULE, LEVEL, __VA_ARGS__); \
262 #define VLOG_DEFINE_MODULE__(MODULE) \
263 extern struct vlog_module VLM_##MODULE; \
264 struct vlog_module VLM_##MODULE = \
266 #MODULE, /* name */ \
267 { [ 0 ... VLF_N_FACILITIES - 1] = VLL_INFO }, /* levels */ \
268 VLL_INFO, /* min_level */ \