common: support syslog

Author: liudongmiao

CMakeLists.txt

@@ -23,6 +23,12 @@ endif()
 
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Wextra -Werror")
 
+include(CheckSymbolExists)
+check_symbol_exists(syslog "syslog.h" HAVE_SYSLOG)
+if (HAVE_SYSLOG)
+    add_definitions(-DHAVE_SYSLOG)
+endif()
+
 include(CheckFunctionExists)
 
 find_package(OpenSSL 1.1.1 REQUIRED)

common.c

@@ -120,12 +120,14 @@ void log_callback(int severity, const char *msg) {
 }
 
 #ifndef NDEBUG
-static enum log_level log_level = DEBUG;
+static volatile int log_level = DEBUG;
 #else
-static enum log_level log_level = INFO;
+static volatile int log_level = INFO;
 #endif
 
-static void set_log_level(enum log_level level) {
+static volatile int log_to_syslog = -1;
+
+static void set_log_level(int level) {
     log_level = level;
 }
 
@@ -141,10 +143,32 @@ void init_log_level(const char *loglevel) {
     }
 }
 
-enum log_level get_log_level() {
+int get_log_level() {
     return log_level;
 }
 
+int use_syslog(void) {
+    if (log_to_syslog == -1) {
+#ifdef HAVE_SYSLOG
+        log_to_syslog = find_option(getenv("SS_PLUGIN_OPTIONS"), "syslog", "1") != NULL;
+        if (log_to_syslog) {
+            openlog(LOGGER_NAME, LOG_PID | LOG_CONS, LOG_DAEMON);
+        }
+#else
+        log_to_syslog = 0;
+#endif
+    }
+    return log_to_syslog;
+}
+
+void close_syslog(void) {
+#ifdef HAVE_SYSLOG
+    if (log_to_syslog) {
+        closelog();
+    }
+#endif
+}
+
 const char *find_option(const char *options, const char *key, const char *no_value) {
     size_t len;
     const char *pos, *value;

common.h

@@ -12,6 +12,11 @@
 #ifdef WSS_PROXY_CLIENT
 #include <openssl/lhash.h>
 #endif
+#ifdef HAVE_SYSLOG
+#include <syslog.h>
+#else
+#define syslog(x, y, ...) do {} while (0)
+#endif
 #include "ws-header.h"
 
 #ifndef WSS_PAYLOAD_SIZE
@@ -44,12 +49,17 @@
 
 #define TIME_FORMAT "%Y-%m-%d %H:%M:%S"
 
-enum log_level {
-    DEBUG,
-    INFO,
-    WARN,
-    ERROR,
-};
+#ifdef HAVE_SYSLOG
+#define DEBUG   LOG_DEBUG
+#define INFO    LOG_INFO
+#define WARN    LOG_WARNING
+#define ERROR   LOG_ERR
+#else
+#define DEBUG   7
+#define INFO    6
+#define WARN    4
+#define ERROR   3
+#endif
 
 #define MAX_UDP_FRAME_SIZE 65535
 #define UDP_FRAME_LENGTH_SIZE 2
@@ -109,18 +119,26 @@ void log_callback(int severity, const char *msg);
 
 void init_log_level(const char *loglevel);
 
-enum log_level get_log_level(void);
-
-#define LOG(format, stream, level, ...)                                             \
-    do {                                                                            \
-        if (get_log_level() <= level) {                                             \
-            time_t now = time(NULL);                                                \
-            char timestr[20];                                                       \
-            strftime(timestr, 20, TIME_FORMAT, localtime(&now));                    \
-            fprintf(stream, " %s " #level " " LOGGER_NAME " " format "\n", timestr, \
-                        ## __VA_ARGS__);                                            \
-            fflush(stream);                                                         \
-        }                                                                           \
+int get_log_level(void);
+
+int use_syslog(void);
+
+void close_syslog(void);
+
+#define LOG(format, stream, level, ...)                                         \
+    do {                                                                        \
+        if (get_log_level() >= level) {                                         \
+            if (use_syslog()) {                                                 \
+                syslog(level, format,  ## __VA_ARGS__);                         \
+            } else {                                                            \
+                time_t now = time(NULL);                                        \
+                char timestr[20];                                               \
+                strftime(timestr, 20, TIME_FORMAT, localtime(&now));            \
+                fprintf(stream, " %s " #level " " LOGGER_NAME " " format "\n",  \
+                        timestr, ## __VA_ARGS__);                               \
+                fflush(stream);                                                 \
+            }                                                                   \
+        }                                                                       \
     } while (0)
 
 #define LOGD(format, ...) LOG(format, stdout, DEBUG, ## __VA_ARGS__)

wss-proxy-client.c

@@ -655,5 +655,6 @@ int main() {
     if (wss_context.server.path) {
         free((char *) wss_context.server.path);
     }
+    close_syslog();
     return code;
 }

wss-proxy-server.c

@@ -328,5 +328,6 @@ int main() {
     if (cfg) {
         event_config_free(cfg);
     }
+    close_syslog();
     return code;
 }