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 #ifndef DEBUG
  47     if (crit == LOG_DEBUG) {
  48         return 0;
  49     }
  50 #endif
  51     switch (crit) {
  52     case LOG_INFO:
  53         urgency = "[INFO] ";
  54         break;
  55     case LOG_WARNING:
  56         urgency = "[WARNING] ";
  57         break;
  58     case LOG_ERR:
  59         urgency = "[ERROR] ";
  60         break;
  61     case LOG_NOTICE:
  62         urgency = "[NOTICE] ";
  63         break;
  64     case LOG_DEBUG:
  65         urgency = "[DEBUG] ";
  66         break;
  67     default:
  68         urgency = "";
  69     }
  70     va_start(va, format);
  71     len = (size_t) evutil_vsnprintf(line, sizeof line, format, va);
  72     va_end(va);
  73
  74     if (len >= sizeof line) {
  75         assert(sizeof line > (size_t) 0U);
  76         len = sizeof line - (size_t) 1U;
  77     }
  78     line[len++] = 0;
  79 #ifndef _WIN32
  80     if (context != NULL && context->log_fd == -1 && context->daemonize) {
  81         syslog(crit, "%s", line);
  82         return 0;
  83     }
  84 #endif
  85     if (memcmp(previous_line, line, len) == 0) {
  86         burst_counter++;
  87         if (burst_counter > LOGGER_ALLOWED_BURST_FOR_IDENTICAL_LOG_ENTRIES &&
  88             now - last_log_ts < LOGGER_DELAY_BETWEEN_IDENTICAL_LOG_ENTRIES) {
  89             return 1;
  90         }
  91     } else {
  92         burst_counter = 0U;
  93     }
  94     last_log_ts = now;
  95     assert(sizeof previous_line >= sizeof line);
  96     memcpy(previous_line, line, len);
  97     if (context == NULL || context->log_fd == -1) {
  98         log_fd = STDERR_FILENO;
  99     } else {
 100         log_fd = context->log_fd;
 101     }
 102 #ifndef _WIN32
 103     safe_write(log_fd, urgency, strlen(urgency), LOG_WRITE_TIMEOUT);
 104     safe_write(log_fd, line, strlen(line), LOG_WRITE_TIMEOUT);
 105     safe_write(log_fd, "\n", (size_t) 1U, LOG_WRITE_TIMEOUT);
 106 #else
 107     (void) log_fd;
 108     printf("%s%s\n", urgency, line);
 109     fflush(stdout);
 110 #endif
 111
 112     return 0;
 113 }
 114
 115 int
 116 logger_noformat(struct ProxyContext_ * const context,
 117                  const int crit, const char * const msg)
 118 {
 119     return logger(context, crit, "%s", msg);
 120 }
 121
 122 int
 123 logger_error(struct ProxyContext_ * const context,
 124               const char * const msg)
 125 {
 126     const char *const err_msg = strerror(errno);
 127
 128     return logger(context, LOG_ERR, "%s: %s", msg, err_msg);
 129 }
 130
 131 int
 132 logger_close(struct ProxyContext_ * const context)
 133 {
 134 #ifdef _WIN32
 135     (void) context;
 136 #else
 137     if (context->daemonize) {
 138         closelog();
 139     }
 140     if (context->log_fd != -1) {
 141         fsync(context->log_fd);
 142         return close(context->log_fd);
 143     }
 144 #endif
 145     return 0;
 146 }