include/openvswitch/vlog.h

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013, 2016 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 OPENVSWITCH_VLOG_H
  18 #define OPENVSWITCH_VLOG_H 1
  19
  20 /* Logging.
  21  *
  22  *
  23  * Thread-safety
  24  * =============
  25  *
  26  * Fully thread safe.
  27  */
  28
  29 #include <limits.h>
  30 #include <stdarg.h>
  31 #include <stdbool.h>
  32 #include <time.h>
  33 #include <openvswitch/compiler.h>
  34 #include <openvswitch/list.h>
  35 #include <openvswitch/thread.h>
  36 #include <openvswitch/token-bucket.h>
  37 #include <openvswitch/util.h>
  38
  39 #ifdef  __cplusplus
  40 extern "C" {
  41 #endif
  42
  43 /* Logging severity levels.
  44  *
  45  * ovs-appctl(8) defines each of the log levels. */
  46 #define VLOG_LEVELS                             \
  47     VLOG_LEVEL(OFF,  LOG_ALERT,   1)            \
  48     VLOG_LEVEL(EMER, LOG_ALERT,   1)            \
  49     VLOG_LEVEL(ERR,  LOG_ERR,     3)            \
  50     VLOG_LEVEL(WARN, LOG_WARNING, 4)            \
  51     VLOG_LEVEL(INFO, LOG_NOTICE,  5)            \
  52     VLOG_LEVEL(DBG,  LOG_DEBUG,   7)
  53 enum vlog_level {
  54 #define VLOG_LEVEL(NAME, SYSLOG_LEVEL, RFC5424_LEVEL) VLL_##NAME,
  55     VLOG_LEVELS
  56 #undef VLOG_LEVEL
  57     VLL_N_LEVELS
  58 };
  59
  60 const char *vlog_get_level_name(enum vlog_level);
  61 enum vlog_level vlog_get_level_val(const char *name);
  62
  63 /* Destinations that we can log to. */
  64 #define VLOG_DESTINATIONS                                                 \
  65     VLOG_DESTINATION(SYSLOG, "ovs|%05N|%c%T|%p|%m")                        \
  66     VLOG_DESTINATION(CONSOLE, "%D{%Y-%m-%dT%H:%M:%SZ}|%05N|%c%T|%p|%m")    \
  67     VLOG_DESTINATION(FILE, "%D{%Y-%m-%dT%H:%M:%S.###Z}|%05N|%c%T|%p|%m")
  68 enum vlog_destination {
  69 #define VLOG_DESTINATION(NAME, PATTERN) VLF_##NAME,
  70     VLOG_DESTINATIONS
  71 #undef VLOG_DESTINATION
  72     VLF_N_DESTINATIONS,
  73     VLF_ANY_DESTINATION = -1
  74 };
  75
  76 const char *vlog_get_destination_name(enum vlog_destination);
  77 enum vlog_destination vlog_get_destination_val(const char *name);
  78
  79 /* A log module. */
  80 struct vlog_module {
  81     struct ovs_list list;
  82     const char *name;             /* User-visible name. */
  83     int levels[VLF_N_DESTINATIONS]; /* Minimum log level for each
  84                                        destination. */
  85     int min_level;                /* Minimum log level for any destination. */
  86     bool honor_rate_limits;       /* Set false to ignore rate limits. */
  87 };
  88
  89 void vlog_insert_module(struct ovs_list *);
  90
  91 const char *vlog_get_module_name(const struct vlog_module *);
  92 struct vlog_module *vlog_module_from_name(const char *name);
  93
  94 /* Rate-limiter for log messages. */
  95 struct vlog_rate_limit {
  96     struct token_bucket token_bucket;
  97     time_t first_dropped;       /* Time first message was dropped. */
  98     time_t last_dropped;        /* Time of most recent message drop. */
  99     unsigned int n_dropped;     /* Number of messages dropped. */
 100     struct ovs_mutex mutex;     /* Mutual exclusion for rate limit. */
 101 };
 102
 103 /* Number of tokens to emit a message.  We add 'rate' tokens per millisecond,
 104  * thus 60,000 tokens are required to emit one message per minute. */
 105 #define VLOG_MSG_TOKENS (60 * 1000)
 106
 107 /* Initializer for a struct vlog_rate_limit, to set up a maximum rate of RATE
 108  * messages per minute and a maximum burst size of BURST messages. */
 109 #define VLOG_RATE_LIMIT_INIT(RATE, BURST)                                 \
 110         {                                                                 \
 111             TOKEN_BUCKET_INIT(RATE, OVS_SAT_MUL(BURST, VLOG_MSG_TOKENS)), \
 112             0,                              /* first_dropped */           \
 113             0,                              /* last_dropped */            \
 114             0,                              /* n_dropped */               \
 115             OVS_MUTEX_INITIALIZER           /* mutex */                   \
 116         }
 117
 118 /* Configuring how each module logs messages. */
 119 enum vlog_level vlog_get_level(const struct vlog_module *,
 120                                enum vlog_destination);
 121 void vlog_set_levels(struct vlog_module *,
 122                      enum vlog_destination, enum vlog_level);
 123 char *vlog_set_levels_from_string(const char *) OVS_WARN_UNUSED_RESULT;
 124 void vlog_set_levels_from_string_assert(const char *);
 125 char *vlog_get_levels(void);
 126 char *vlog_get_patterns(void);
 127 bool vlog_is_enabled(const struct vlog_module *, enum vlog_level);
 128 bool vlog_should_drop(const struct vlog_module *, enum vlog_level,
 129                       struct vlog_rate_limit *);
 130 void vlog_set_verbosity(const char *arg);
 131
 132 /* Configuring log destinations. */
 133 void vlog_set_pattern(enum vlog_destination, const char *pattern);
 134 int vlog_set_log_file(const char *file_name);
 135 int vlog_reopen_log_file(void);
 136 #ifndef _WIN32
 137 void vlog_change_owner_unix(uid_t, gid_t);
 138 #endif
 139
 140 /* Configure method how vlog should send messages to syslog server. */
 141 void vlog_set_syslog_method(const char *method);
 142
 143 /* Configure syslog target. */
 144 void vlog_set_syslog_target(const char *target);
 145
 146 /* Initialization. */
 147 void vlog_init(void);
 148 void vlog_enable_async(void);
 149
 150 /* Functions for actual logging. */
 151 void vlog(const struct vlog_module *, enum vlog_level, const char *format, ...)
 152     OVS_PRINTF_FORMAT (3, 4);
 153 void vlog_valist(const struct vlog_module *, enum vlog_level,
 154                  const char *, va_list)
 155     OVS_PRINTF_FORMAT (3, 0);
 156
 157 OVS_NO_RETURN void vlog_fatal(const struct vlog_module *, const char *format, ...)
 158     OVS_PRINTF_FORMAT (2, 3);
 159 OVS_NO_RETURN void vlog_fatal_valist(const struct vlog_module *,
 160                                  const char *format, va_list)
 161     OVS_PRINTF_FORMAT (2, 0);
 162
 163 OVS_NO_RETURN void vlog_abort(const struct vlog_module *, const char *format, ...)
 164     OVS_PRINTF_FORMAT (2, 3);
 165 OVS_NO_RETURN void vlog_abort_valist(const struct vlog_module *,
 166                                  const char *format, va_list)
 167     OVS_PRINTF_FORMAT (2, 0);
 168
 169 void vlog_rate_limit(const struct vlog_module *, enum vlog_level,
 170                      struct vlog_rate_limit *, const char *, ...)
 171     OVS_PRINTF_FORMAT (4, 5);
 172
 173 /* Defines a logging module whose name is MODULE, which should generally be
 174  * roughly the name of the source file, and makes it the module used by the
 175  * logging convenience macros defined below. */
 176 #define VLOG_DEFINE_THIS_MODULE(MODULE)                                 \
 177         static struct vlog_module this_module = {                       \
 178             OVS_LIST_INITIALIZER(&this_module.list),                    \
 179             #MODULE,                                        /* name */  \
 180             { VLL_INFO, VLL_INFO, VLL_INFO },             /* levels */  \
 181             VLL_INFO,                                  /* min_level */  \
 182             true                               /* honor_rate_limits */  \
 183         };                                                              \
 184         OVS_CONSTRUCTOR(init_this_module_##MODULE) {                    \
 185             vlog_insert_module(&this_module.list);                      \
 186         }                                                               \
 187                                                                         \
 188         /* Prevent duplicate module names, via linker error.            \
 189          * The extra "extern" declaration makes sparse happy. */        \
 190         extern struct vlog_module *VLM_##MODULE;                        \
 191         struct vlog_module *VLM_##MODULE = &this_module;
 192
 193 /* Macros for the current module as set up by VLOG_DEFINE_THIS_MODULE.
 194  * These are usually what you want to use.
 195  *
 196  * Guaranteed to preserve errno.
 197  */
 198 #define VLOG_FATAL(...) vlog_fatal(&this_module, __VA_ARGS__)
 199 #define VLOG_ABORT(...) vlog_abort(&this_module, __VA_ARGS__)
 200 #define VLOG_EMER(...) VLOG(VLL_EMER, __VA_ARGS__)
 201 #define VLOG_ERR(...) VLOG(VLL_ERR, __VA_ARGS__)
 202 #define VLOG_WARN(...) VLOG(VLL_WARN, __VA_ARGS__)
 203 #define VLOG_INFO(...) VLOG(VLL_INFO, __VA_ARGS__)
 204 #define VLOG_DBG(...) VLOG(VLL_DBG, __VA_ARGS__)
 205
 206 /* More convenience macros, for testing whether a given level is enabled.  When
 207  * constructing a log message is expensive, this enables it to be skipped. */
 208 #define VLOG_IS_ERR_ENABLED() vlog_is_enabled(&this_module, VLL_ERR)
 209 #define VLOG_IS_WARN_ENABLED() vlog_is_enabled(&this_module, VLL_WARN)
 210 #define VLOG_IS_INFO_ENABLED() vlog_is_enabled(&this_module, VLL_INFO)
 211 #define VLOG_IS_DBG_ENABLED() vlog_is_enabled(&this_module, VLL_DBG)
 212
 213 /* Convenience macros for rate-limiting.
 214  * Guaranteed to preserve errno.
 215  */
 216 #define VLOG_ERR_RL(RL, ...) VLOG_RL(RL, VLL_ERR, __VA_ARGS__)
 217 #define VLOG_WARN_RL(RL, ...) VLOG_RL(RL, VLL_WARN, __VA_ARGS__)
 218 #define VLOG_INFO_RL(RL, ...) VLOG_RL(RL, VLL_INFO, __VA_ARGS__)
 219 #define VLOG_DBG_RL(RL, ...) VLOG_RL(RL, VLL_DBG, __VA_ARGS__)
 220
 221 /* Convenience macros to additionally store log message in buffer
 222  * Caller is responsible for freeing *ERRP afterwards */
 223 #define VLOG_ERR_BUF(ERRP, ...) VLOG_ERRP(ERRP, VLL_ERR, __VA_ARGS__)
 224 #define VLOG_WARN_BUF(ERRP, ...) VLOG_ERRP(ERRP, VLL_WARN, __VA_ARGS__)
 225
 226 #define VLOG_DROP_ERR(RL) vlog_should_drop(&this_module, VLL_ERR, RL)
 227 #define VLOG_DROP_WARN(RL) vlog_should_drop(&this_module, VLL_WARN, RL)
 228 #define VLOG_DROP_INFO(RL) vlog_should_drop(&this_module, VLL_INFO, RL)
 229 #define VLOG_DROP_DBG(RL) vlog_should_drop(&this_module, VLL_DBG, RL)
 230
 231 /* Macros for logging at most once per execution. */
 232 #define VLOG_ERR_ONCE(...) VLOG_ONCE(VLL_ERR, __VA_ARGS__)
 233 #define VLOG_WARN_ONCE(...) VLOG_ONCE(VLL_WARN, __VA_ARGS__)
 234 #define VLOG_INFO_ONCE(...) VLOG_ONCE(VLL_INFO, __VA_ARGS__)
 235 #define VLOG_DBG_ONCE(...) VLOG_ONCE(VLL_DBG, __VA_ARGS__)
 236
 237 /* Command line processing. */
 238 #define VLOG_OPTION_ENUMS                       \
 239         OPT_LOG_FILE,                           \
 240         OPT_SYSLOG_IMPL,                        \
 241         OPT_SYSLOG_TARGET
 242
 243 #define VLOG_LONG_OPTIONS                                               \
 244         {"verbose",       optional_argument, NULL, 'v'},                \
 245         {"log-file",      optional_argument, NULL, OPT_LOG_FILE},       \
 246         {"syslog-method", optional_argument, NULL, OPT_SYSLOG_IMPL},    \
 247         {"syslog-target", required_argument, NULL, OPT_SYSLOG_TARGET}
 248
 249 #define VLOG_OPTION_HANDLERS                    \
 250         case 'v':                               \
 251             vlog_set_verbosity(optarg);         \
 252             break;                              \
 253         case OPT_LOG_FILE:                      \
 254             vlog_set_log_file(optarg);          \
 255             break;                              \
 256         case OPT_SYSLOG_IMPL:                   \
 257             vlog_set_syslog_method(optarg);     \
 258             break;                              \
 259         case OPT_SYSLOG_TARGET:                 \
 260             vlog_set_syslog_target(optarg);     \
 261             break;
 262
 263 void vlog_usage(void);
 264
 265 /* Implementation details. */
 266 #define VLOG(LEVEL, ...)                                \
 267     do {                                                \
 268         enum vlog_level level__ = LEVEL;                \
 269         if (this_module.min_level >= level__) {         \
 270             vlog(&this_module, level__, __VA_ARGS__);   \
 271         }                                               \
 272     } while (0)
 273 #define VLOG_RL(RL, LEVEL, ...)                                         \
 274     do {                                                                \
 275         enum vlog_level level__ = LEVEL;                                \
 276         if (this_module.min_level >= level__) {                         \
 277             vlog_rate_limit(&this_module, level__, RL, __VA_ARGS__);    \
 278         }                                                               \
 279     } while (0)
 280 #define VLOG_ONCE(LEVEL, ...)                                           \
 281     do {                                                                \
 282         static struct ovsthread_once once = OVSTHREAD_ONCE_INITIALIZER; \
 283         if (ovsthread_once_start(&once)) {                              \
 284             vlog(&this_module, LEVEL, __VA_ARGS__);                     \
 285             ovsthread_once_done(&once);                                 \
 286         }                                                               \
 287     } while (0)
 288 #define VLOG_ERRP(ERRP, LEVEL, ...)                                     \
 289     do {                                                                \
 290         VLOG(LEVEL, __VA_ARGS__);                                       \
 291         if (ERRP) {                                                     \
 292             *(ERRP) = xasprintf(__VA_ARGS__);                           \
 293         }                                                               \
 294     } while (0)
 295
 296 #ifdef  __cplusplus
 297 }
 298 #endif
 299
 300 #endif /* vlog.h */