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1 /*
2 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
3 *
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:
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
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.
15 */
16
17 #ifndef VLOG_H
18 #define VLOG_H 1
19
20 #include <limits.h>
21 #include <stdarg.h>
22 #include <stdbool.h>
23 #include <time.h>
24 #include "compiler.h"
25 #include "sat-math.h"
26 #include "token-bucket.h"
27 #include "util.h"
28
29 #ifdef __cplusplus
30 extern "C" {
31 #endif
32
33 /* Logging severity levels.
34 *
35 * ovs-appctl(8) defines each of the log levels. */
36 #define VLOG_LEVELS \
37 VLOG_LEVEL(OFF, LOG_ALERT) \
38 VLOG_LEVEL(EMER, LOG_ALERT) \
39 VLOG_LEVEL(ERR, LOG_ERR) \
40 VLOG_LEVEL(WARN, LOG_WARNING) \
41 VLOG_LEVEL(INFO, LOG_NOTICE) \
42 VLOG_LEVEL(DBG, LOG_DEBUG)
43 enum vlog_level {
44 #define VLOG_LEVEL(NAME, SYSLOG_LEVEL) VLL_##NAME,
45 VLOG_LEVELS
46 #undef VLOG_LEVEL
47 VLL_N_LEVELS
48 };
49
50 const char *vlog_get_level_name(enum vlog_level);
51 enum vlog_level vlog_get_level_val(const char *name);
52
53 /* Facilities that we can log to. */
54 #define VLOG_FACILITIES \
55 VLOG_FACILITY(SYSLOG, "%05N|%c%T|%p|%m") \
56 VLOG_FACILITY(CONSOLE, "%D{%Y-%m-%dT%H:%M:%SZ}|%05N|%c%T|%p|%m") \
57 VLOG_FACILITY(FILE, "%D{%Y-%m-%dT%H:%M:%SZ}|%05N|%c%T|%p|%m")
58 enum vlog_facility {
59 #define VLOG_FACILITY(NAME, PATTERN) VLF_##NAME,
60 VLOG_FACILITIES
61 #undef VLOG_FACILITY
62 VLF_N_FACILITIES,
63 VLF_ANY_FACILITY = -1
64 };
65
66 const char *vlog_get_facility_name(enum vlog_facility);
67 enum vlog_facility vlog_get_facility_val(const char *name);
68
69 /* A log module. */
70 struct vlog_module {
71 const char *name; /* User-visible name. */
72 int levels[VLF_N_FACILITIES]; /* Minimum log level for each facility. */
73 int min_level; /* Minimum log level for any facility. */
74 bool honor_rate_limits; /* Set false to ignore rate limits. */
75 };
76
77 /* Creates and initializes a global instance of a module named MODULE. */
78 #if USE_LINKER_SECTIONS
79 #define VLOG_DEFINE_MODULE(MODULE) \
80 VLOG_DEFINE_MODULE__(MODULE) \
81 extern struct vlog_module *vlog_module_ptr_##MODULE; \
82 struct vlog_module *vlog_module_ptr_##MODULE \
83 __attribute__((section("vlog_modules"))) = &VLM_##MODULE
84 #else
85 #define VLOG_DEFINE_MODULE(MODULE) extern struct vlog_module VLM_##MODULE
86 #endif
87
88 const char *vlog_get_module_name(const struct vlog_module *);
89 struct vlog_module *vlog_module_from_name(const char *name);
90
91 /* Rate-limiter for log messages. */
92 struct vlog_rate_limit {
93 struct token_bucket token_bucket;
94 time_t first_dropped; /* Time first message was dropped. */
95 time_t last_dropped; /* Time of most recent message drop. */
96 unsigned int n_dropped; /* Number of messages dropped. */
97 };
98
99 /* Number of tokens to emit a message. We add 'rate' tokens per millisecond,
100 * thus 60,000 tokens are required to emit one message per minute. */
101 #define VLOG_MSG_TOKENS (60 * 1000)
102
103 /* Initializer for a struct vlog_rate_limit, to set up a maximum rate of RATE
104 * messages per minute and a maximum burst size of BURST messages. */
105 #define VLOG_RATE_LIMIT_INIT(RATE, BURST) \
106 { \
107 TOKEN_BUCKET_INIT(RATE, SAT_MUL(BURST, VLOG_MSG_TOKENS)), \
108 0, /* first_dropped */ \
109 0, /* last_dropped */ \
110 0, /* n_dropped */ \
111 }
112
113 /* Configuring how each module logs messages. */
114 enum vlog_level vlog_get_level(const struct vlog_module *, enum vlog_facility);
115 void vlog_set_levels(struct vlog_module *,
116 enum vlog_facility, enum vlog_level);
117 char *vlog_set_levels_from_string(const char *) WARN_UNUSED_RESULT;
118 void vlog_set_levels_from_string_assert(const char *);
119 char *vlog_get_levels(void);
120 bool vlog_is_enabled(const struct vlog_module *, enum vlog_level);
121 bool vlog_should_drop(const struct vlog_module *, enum vlog_level,
122 struct vlog_rate_limit *);
123 void vlog_set_verbosity(const char *arg);
124
125 /* Configuring log facilities. */
126 void vlog_set_pattern(enum vlog_facility, const char *pattern);
127 const char *vlog_get_log_file(void);
128 int vlog_set_log_file(const char *file_name);
129 int vlog_reopen_log_file(void);
130
131 /* Initialization. */
132 void vlog_init(void);
133 void vlog_exit(void);
134
135 /* Functions for actual logging. */
136 void vlog(const struct vlog_module *, enum vlog_level, const char *format, ...)
137 PRINTF_FORMAT (3, 4);
138 void vlog_valist(const struct vlog_module *, enum vlog_level,
139 const char *, va_list)
140 PRINTF_FORMAT (3, 0);
141
142 void vlog_fatal(const struct vlog_module *, const char *format, ...)
143 PRINTF_FORMAT (2, 3) NO_RETURN;
144 void vlog_fatal_valist(const struct vlog_module *, const char *format, va_list)
145 PRINTF_FORMAT (2, 0) NO_RETURN;
146
147 void vlog_abort(const struct vlog_module *, const char *format, ...)
148 PRINTF_FORMAT (2, 3) NO_RETURN;
149 void vlog_abort_valist(const struct vlog_module *, const char *format, va_list)
150 PRINTF_FORMAT (2, 0) NO_RETURN;
151
152 void vlog_rate_limit(const struct vlog_module *, enum vlog_level,
153 struct vlog_rate_limit *, const char *, ...)
154 PRINTF_FORMAT (4, 5);
155
156 /* Creates and initializes a global instance of a module named MODULE, and
157 * defines a static variable named THIS_MODULE that points to it, for use with
158 * the convenience macros below. */
159 #define VLOG_DEFINE_THIS_MODULE(MODULE) \
160 VLOG_DEFINE_MODULE(MODULE); \
161 static struct vlog_module *const THIS_MODULE = &VLM_##MODULE
162
163 /* Convenience macros. These assume that THIS_MODULE points to a "struct
164 * vlog_module" for the current module, as set up by e.g. the
165 * VLOG_DEFINE_MODULE macro above.
166 *
167 * Guaranteed to preserve errno.
168 */
169 #define VLOG_FATAL(...) vlog_fatal(THIS_MODULE, __VA_ARGS__)
170 #define VLOG_ABORT(...) vlog_abort(THIS_MODULE, __VA_ARGS__)
171 #define VLOG_EMER(...) VLOG(VLL_EMER, __VA_ARGS__)
172 #define VLOG_ERR(...) VLOG(VLL_ERR, __VA_ARGS__)
173 #define VLOG_WARN(...) VLOG(VLL_WARN, __VA_ARGS__)
174 #define VLOG_INFO(...) VLOG(VLL_INFO, __VA_ARGS__)
175 #define VLOG_DBG(...) VLOG(VLL_DBG, __VA_ARGS__)
176
177 /* More convenience macros, for testing whether a given level is enabled in
178 * THIS_MODULE. When constructing a log message is expensive, this enables it
179 * to be skipped. */
180 #define VLOG_IS_ERR_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_ERR)
181 #define VLOG_IS_WARN_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_WARN)
182 #define VLOG_IS_INFO_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_INFO)
183 #define VLOG_IS_DBG_ENABLED() vlog_is_enabled(THIS_MODULE, VLL_DBG)
184
185 /* Convenience macros for rate-limiting.
186 * Guaranteed to preserve errno.
187 */
188 #define VLOG_ERR_RL(RL, ...) VLOG_RL(RL, VLL_ERR, __VA_ARGS__)
189 #define VLOG_WARN_RL(RL, ...) VLOG_RL(RL, VLL_WARN, __VA_ARGS__)
190 #define VLOG_INFO_RL(RL, ...) VLOG_RL(RL, VLL_INFO, __VA_ARGS__)
191 #define VLOG_DBG_RL(RL, ...) VLOG_RL(RL, VLL_DBG, __VA_ARGS__)
192
193 #define VLOG_DROP_ERR(RL) vlog_should_drop(THIS_MODULE, VLL_ERR, RL)
194 #define VLOG_DROP_WARN(RL) vlog_should_drop(THIS_MODULE, VLL_WARN, RL)
195 #define VLOG_DROP_INFO(RL) vlog_should_drop(THIS_MODULE, VLL_INFO, RL)
196 #define VLOG_DROP_DBG(RL) vlog_should_drop(THIS_MODULE, VLL_DBG, RL)
197
198 /* Macros for logging at most once per execution. */
199 #define VLOG_ERR_ONCE(...) VLOG_ONCE(VLL_ERR, __VA_ARGS__)
200 #define VLOG_WARN_ONCE(...) VLOG_ONCE(VLL_WARN, __VA_ARGS__)
201 #define VLOG_INFO_ONCE(...) VLOG_ONCE(VLL_INFO, __VA_ARGS__)
202 #define VLOG_DBG_ONCE(...) VLOG_ONCE(VLL_DBG, __VA_ARGS__)
203
204 /* Command line processing. */
205 #define VLOG_OPTION_ENUMS OPT_LOG_FILE
206 #define VLOG_LONG_OPTIONS \
207 {"verbose", optional_argument, NULL, 'v'}, \
208 {"log-file", optional_argument, NULL, OPT_LOG_FILE}
209 #define VLOG_OPTION_HANDLERS \
210 case 'v': \
211 vlog_set_verbosity(optarg); \
212 break; \
213 case OPT_LOG_FILE: \
214 vlog_set_log_file(optarg); \
215 break;
216 void vlog_usage(void);
217
218 /* Implementation details. */
219 #define VLOG(LEVEL, ...) \
220 do { \
221 enum vlog_level level__ = LEVEL; \
222 if (THIS_MODULE->min_level >= level__) { \
223 vlog(THIS_MODULE, level__, __VA_ARGS__); \
224 } \
225 } while (0)
226 #define VLOG_RL(RL, LEVEL, ...) \
227 do { \
228 enum vlog_level level__ = LEVEL; \
229 if (THIS_MODULE->min_level >= level__) { \
230 vlog_rate_limit(THIS_MODULE, level__, RL, __VA_ARGS__); \
231 } \
232 } while (0)
233 #define VLOG_ONCE(LEVEL, ...) \
234 do { \
235 static bool already_logged; \
236 if (!already_logged) { \
237 already_logged = true; \
238 vlog(THIS_MODULE, LEVEL, __VA_ARGS__); \
239 } \
240 } while (0)
241
242 #define VLOG_DEFINE_MODULE__(MODULE) \
243 extern struct vlog_module VLM_##MODULE; \
244 struct vlog_module VLM_##MODULE = \
245 { \
246 #MODULE, /* name */ \
247 { [ 0 ... VLF_N_FACILITIES - 1] = VLL_INFO }, /* levels */ \
248 VLL_INFO, /* min_level */ \
249 true /* honor_rate_limits */ \
250 };
251
252 #ifdef __cplusplus
253 }
254 #endif
255
256
257 #endif /* vlog.h */