release/src/router/dnscrypt/src/proxy/logger.c

   1
   2 #include <config.h>
   3 #include <sys/types.h>
   4
   5 #include <assert.h>
   6 #include <errno.h>
   7 #include <stdio.h>
   8 #include <string.h>
   9 #ifndef _WIN32
  10 # include <syslog.h>
  11 #endif
  12 #include <stdarg.h>
  13 #include <time.h>
  14 #include <unistd.h>
  15
  16 #include <event2/util.h>
  17
  18 #include "dnscrypt_proxy.h"
  19 #include "logger.h"
  20 #include "safe_rw.h"
  21
  22 int
  23 logger_open_syslog(struct ProxyContext_ * const context)
  24 {
  25     assert(context->daemonize != 0);
  26 #ifndef _WIN32
  27     openlog(PACKAGE_TARNAME, LOG_NDELAY | LOG_PID, LOG_DAEMON);
  28 #endif
  29     return 0;
  30 }
  31
  32 int
  33 logger(struct ProxyContext_ * const context,
  34        const int crit, const char * const format, ...)
  35 {
  36     static char         previous_line[MAX_LOG_LINE];
  37     static time_t       last_log_ts = (time_t) 0;
  38     static unsigned int burst_counter = 0U;
  39     char        line[MAX_LOG_LINE];
  40     va_list     va;
  41     const char *urgency;
  42     time_t      now = time(NULL);
  43     size_t      len;
  44     int         log_fd;
  45
  46     if (context != NULL) {
  47         if (crit > context->max_log_level) {
  48             return 0;
  49         }
  50     } else {
  51 #ifndef DEBUG
  52         if (crit > LOG_INFO) {
  53             return 0;
  54         }
  55 #endif
  56     }
  57     switch (crit) {
  58     case LOG_INFO:
  59         urgency = "[INFO] ";
  60         break;
  61     case LOG_WARNING:
  62         urgency = "[WARNING] ";
  63         break;
  64     case LOG_ERR:
  65         urgency = "[ERROR] ";
  66         break;
  67     case LOG_NOTICE:
  68         urgency = "[NOTICE] ";
  69         break;
  70     case LOG_DEBUG:
  71         urgency = "[DEBUG] ";
  72         break;
  73     default:
  74         urgency = "";
  75     }
  76     va_start(va, format);
  77     len = (size_t) evutil_vsnprintf(line, sizeof line, format, va);
  78     va_end(va);
  79
  80     if (len >= sizeof line) {
  81         assert(sizeof line > (size_t) 0U);
  82         len = sizeof line - (size_t) 1U;
  83     }
  84     line[len++] = 0;
  85 #ifndef _WIN32
  86     if (context != NULL && context->log_fd == -1 && context->daemonize) {
  87         syslog(crit, "%s", line);
  88         return 0;
  89     }
  90 #endif
  91     if (memcmp(previous_line, line, len) == 0) {
  92         burst_counter++;
  93         if (burst_counter > LOGGER_ALLOWED_BURST_FOR_IDENTICAL_LOG_ENTRIES &&
  94             now - last_log_ts < LOGGER_DELAY_BETWEEN_IDENTICAL_LOG_ENTRIES) {
  95             return 1;
  96         }
  97     } else {
  98         burst_counter = 0U;
  99     }
 100     last_log_ts = now;
 101     assert(sizeof previous_line >= sizeof line);
 102     memcpy(previous_line, line, len);
 103     if (context == NULL || context->log_fd == -1) {
 104         log_fd = STDERR_FILENO;
 105     } else {
 106         log_fd = context->log_fd;
 107     }
 108 #ifndef _WIN32
 109     safe_write(log_fd, urgency, strlen(urgency), LOG_WRITE_TIMEOUT);
 110     safe_write(log_fd, line, strlen(line), LOG_WRITE_TIMEOUT);
 111     safe_write(log_fd, "\n", (size_t) 1U, LOG_WRITE_TIMEOUT);
 112 #else
 113     (void) log_fd;
 114     printf("%s%s\n", urgency, line);
 115     fflush(stdout);
 116 #endif
 117
 118     return 0;
 119 }
 120
 121 int
 122 logger_noformat(struct ProxyContext_ * const context,
 123                  const int crit, const char * const msg)
 124 {
 125     return logger(context, crit, "%s", msg);
 126 }
 127
 128 int
 129 logger_error(struct ProxyContext_ * const context,
 130               const char * const msg)
 131 {
 132     const char *const err_msg = strerror(errno);
 133
 134     return logger(context, LOG_ERR, "%s: %s", msg, err_msg);
 135 }
 136
 137 int
 138 logger_close(struct ProxyContext_ * const context)
 139 {
 140 #ifdef _WIN32
 141     (void) context;
 142 #else
 143     if (context->daemonize) {
 144         closelog();
 145     }
 146     if (context->log_fd != -1) {
 147         fsync(context->log_fd);
 148         return close(context->log_fd);
 149     }
 150 #endif
 151     return 0;
 152 }