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.
30 /* Logging importance levels.
32 * The following log levels, in descending order of importance, are enabled by
35 * - EMER: Not currently used.
37 * - ERR: A high-level operation or a subsystem failed. Attention is
40 * - WARN: A low-level operation failed, but higher-level subsystems may be
43 * - INFO: Information that may be useful in retrospect when investigating
46 * The lowest log level is not enabled by default:
48 * - DBG: Information useful only to someone with intricate knowledge of the
49 * system, or that would commonly cause too-voluminous log output.
52 VLOG_LEVEL(EMER, LOG_ALERT) \
53 VLOG_LEVEL(ERR, LOG_ERR) \
54 VLOG_LEVEL(WARN, LOG_WARNING) \
55 VLOG_LEVEL(INFO, LOG_NOTICE) \
56 VLOG_LEVEL(DBG, LOG_DEBUG)
58 #define VLOG_LEVEL(NAME, SYSLOG_LEVEL) VLL_##NAME,
64 const char *vlog_get_level_name(enum vlog_level);
65 enum vlog_level vlog_get_level_val(const char *name);
67 /* Facilities that we can log to. */
68 #define VLOG_FACILITIES \
69 VLOG_FACILITY(SYSLOG, "%05N|%c|%p|%m") \
70 VLOG_FACILITY(CONSOLE, "%d{%b %d %H:%M:%S}|%05N|%c|%p|%m") \
71 VLOG_FACILITY(FILE, "%d{%b %d %H:%M:%S}|%05N|%c|%p|%m")
73 #define VLOG_FACILITY(NAME, PATTERN) VLF_##NAME,
80 const char *vlog_get_facility_name(enum vlog_facility);
81 enum vlog_facility vlog_get_facility_val(const char *name);
85 const char *name; /* User-visible name. */
86 int levels[VLF_N_FACILITIES]; /* Minimum log level for each facility. */
87 int min_level; /* Minimum log level for any facility. */
90 /* Creates and initializes a global instance of a module named MODULE. */
91 #if USE_LINKER_SECTIONS
92 #define VLOG_DEFINE_MODULE(MODULE) \
93 VLOG_DEFINE_MODULE__(MODULE) \
94 struct vlog_module *vlog_module_ptr_##MODULE \
95 __attribute__((section("vlog_modules"))) = &VLM_##MODULE
97 #define VLOG_DEFINE_MODULE(MODULE) extern struct vlog_module VLM_##MODULE
100 const char *vlog_get_module_name(const struct vlog_module *);
101 struct vlog_module *vlog_module_from_name(const char *name);
103 /* Rate-limiter for log messages. */
104 struct vlog_rate_limit {
105 /* Configuration settings. */
106 unsigned int rate; /* Tokens per second. */
107 unsigned int burst; /* Max cumulative tokens credit. */
109 /* Current status. */
110 unsigned int tokens; /* Current number of tokens. */
111 time_t last_fill; /* Last time tokens added. */
112 time_t first_dropped; /* Time first message was dropped. */
113 unsigned int n_dropped; /* Number of messages dropped. */
116 /* Number of tokens to emit a message. We add 'rate' tokens per second, which
117 * is 60 times the unit used for 'rate', thus 60 tokens are required to emit
119 #define VLOG_MSG_TOKENS 60
121 /* Initializer for a struct vlog_rate_limit, to set up a maximum rate of RATE
122 * messages per minute and a maximum burst size of BURST messages. */
123 #define VLOG_RATE_LIMIT_INIT(RATE, BURST) \
126 (MIN(BURST, UINT_MAX / VLOG_MSG_TOKENS) \
127 * VLOG_MSG_TOKENS), /* burst */ \
130 0, /* first_dropped */ \
134 /* Configuring how each module logs messages. */
135 enum vlog_level vlog_get_level(const struct vlog_module *, enum vlog_facility);
136 void vlog_set_levels(struct vlog_module *,
137 enum vlog_facility, enum vlog_level);
138 char *vlog_set_levels_from_string(const char *);
139 char *vlog_get_levels(void);
140 bool vlog_is_enabled(const struct vlog_module *, enum vlog_level);
141 bool vlog_should_drop(const struct vlog_module *, enum vlog_level,
142 struct vlog_rate_limit *);
143 void vlog_set_verbosity(const char *arg);
145 /* Configuring log facilities. */
146 void vlog_set_pattern(enum vlog_facility, const char *pattern);
147 const char *vlog_get_log_file(void);
148 int vlog_set_log_file(const char *file_name);
149 int vlog_reopen_log_file(void);
151 /* Initialization. */
152 void vlog_init(void);
153 void vlog_exit(void);
155 /* Functions for actual logging. */
156 void vlog(const struct vlog_module *, enum vlog_level, const char *format, ...)
157 __attribute__((format(printf, 3, 4)));
158 void vlog_valist(const struct vlog_module *, enum vlog_level,
159 const char *, va_list)
160 __attribute__((format(printf, 3, 0)));
162 void vlog_fatal(const struct vlog_module *, enum vlog_level,
163 const char *format, ...)
164 PRINTF_FORMAT (3, 4) NO_RETURN;
165 void vlog_fatal_valist(const struct vlog_module *, enum vlog_level,
166 const char *, va_list)
167 PRINTF_FORMAT (3, 0) NO_RETURN;
169 void vlog_rate_limit(const struct vlog_module *, enum vlog_level,
170 struct vlog_rate_limit *, const char *, ...)
171 __attribute__((format(printf, 4, 5)));
173 /* Creates and initializes a global instance of a module named MODULE, and
174 * defines a static variable named THIS_MODULE that points to it, for use with
175 * the convenience macros below. */
176 #define VLOG_DEFINE_THIS_MODULE(MODULE) \
177 VLOG_DEFINE_MODULE(MODULE); \
178 static struct vlog_module *const THIS_MODULE = &VLM_##MODULE
180 /* Convenience macros. These assume that THIS_MODULE points to a "struct
181 * vlog_module" for the current module, as set up by e.g. the
182 * VLOG_DEFINE_MODULE macro above.
184 * Guaranteed to preserve errno.
186 #define VLOG_FATAL(...) vlog_fatal(THIS_MODULE, VLL_ERR, __VA_ARGS__)
187 #define VLOG_EMER(...) VLOG(VLL_EMER, __VA_ARGS__)
188 #define VLOG_ERR(...) VLOG(VLL_ERR, __VA_ARGS__)
189 #define VLOG_WARN(...) VLOG(VLL_WARN, __VA_ARGS__)
190 #define VLOG_INFO(...) VLOG(VLL_INFO, __VA_ARGS__)
191 #define VLOG_DBG(...) VLOG(VLL_DBG, __VA_ARGS__)
193 /* More convenience macros, for testing whether a given level is enabled in
194 * THIS_MODULE. When constructing a log message is expensive, this enables it
196 #define VLOG_IS_EMER_ENABLED() true
197 #define VLOG_IS_ERR_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_EMER)
198 #define VLOG_IS_WARN_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_WARN)
199 #define VLOG_IS_INFO_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_INFO)
200 #define VLOG_IS_DBG_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_DBG)
202 /* Convenience macros for rate-limiting.
203 * Guaranteed to preserve errno.
205 #define VLOG_ERR_RL(RL, ...) VLOG_RL(RL, VLL_ERR, __VA_ARGS__)
206 #define VLOG_WARN_RL(RL, ...) VLOG_RL(RL, VLL_WARN, __VA_ARGS__)
207 #define VLOG_INFO_RL(RL, ...) VLOG_RL(RL, VLL_INFO, __VA_ARGS__)
208 #define VLOG_DBG_RL(RL, ...) VLOG_RL(RL, VLL_DBG, __VA_ARGS__)
210 #define VLOG_DROP_ERR(RL) vlog_should_drop(THIS_MODULE, VLL_ERR, RL)
211 #define VLOG_DROP_WARN(RL) vlog_should_drop(THIS_MODULE, VLL_WARN, RL)
212 #define VLOG_DROP_INFO(RL) vlog_should_drop(THIS_MODULE, VLL_INFO, RL)
213 #define VLOG_DROP_DBG(RL) vlog_should_drop(THIS_MODULE, VLL_DBG, RL)
215 /* Macros for logging at most once per execution. */
216 #define VLOG_ERR_ONCE(...) VLOG_ONCE(VLL_ERR, __VA_ARGS__)
217 #define VLOG_WARN_ONCE(...) VLOG_ONCE(VLL_WARN, __VA_ARGS__)
218 #define VLOG_INFO_ONCE(...) VLOG_ONCE(VLL_INFO, __VA_ARGS__)
219 #define VLOG_DBG_ONCE(...) VLOG_ONCE(VLL_DBG, __VA_ARGS__)
221 /* Command line processing. */
222 #define VLOG_OPTION_ENUMS OPT_LOG_FILE
223 #define VLOG_LONG_OPTIONS \
224 {"verbose", optional_argument, 0, 'v'}, \
225 {"log-file", optional_argument, 0, OPT_LOG_FILE}
226 #define VLOG_OPTION_HANDLERS \
228 vlog_set_verbosity(optarg); \
231 vlog_set_log_file(optarg); \
233 void vlog_usage(void);
235 /* Implementation details. */
236 #define VLOG(LEVEL, ...) \
238 if (THIS_MODULE->min_level >= LEVEL) { \
239 vlog(THIS_MODULE, LEVEL, __VA_ARGS__); \
242 #define VLOG_RL(RL, LEVEL, ...) \
244 if (THIS_MODULE->min_level >= LEVEL) { \
245 vlog_rate_limit(THIS_MODULE, LEVEL, RL, __VA_ARGS__); \
248 #define VLOG_ONCE(LEVEL, ...) \
250 static bool already_logged; \
251 if (!already_logged) { \
252 already_logged = true; \
253 vlog(THIS_MODULE, LEVEL, __VA_ARGS__); \
257 #define VLOG_DEFINE_MODULE__(MODULE) \
258 struct vlog_module VLM_##MODULE = \
260 #MODULE, /* name */ \
261 { [ 0 ... VLF_N_FACILITIES - 1] = VLL_INFO }, /* levels */ \
262 VLL_INFO, /* min_level */ \