implement a crude log limiter

fixes #31

daemon/log.c

@@ -5,6 +5,7 @@
 #include <glib.h>
 #include "str.h"
 #include "call.h"
+#include "poller.h"
 
 
 
@@ -60,6 +61,13 @@ const char const* prio_str[] = {
 gboolean _log_stderr = 0;
 int _log_facility = LOG_DAEMON;
 
+
+static GHashTable *__log_limiter;
+static mutex_t __log_limiter_lock;
+static GStringChunk *__log_limiter_strings;
+static unsigned int __log_limiter_count;
+
+
 void log_to_stderr(int facility_priority, char *format, ...) {
 	char *msg;
 	int ret;
@@ -122,6 +130,31 @@ void ilog(int prio, const char *fmt, ...) {
 		return;
 	}
 
+	if ((prio & LOG_FLAG_LIMIT)) {
+		time_t when;
+
+		mutex_lock(&__log_limiter_lock);
+
+		if (__log_limiter_count > 10000) {
+			g_hash_table_remove_all(__log_limiter);
+			g_string_chunk_clear(__log_limiter_strings);
+			__log_limiter_count = 0;
+		}
+
+		when = (time_t) g_hash_table_lookup(__log_limiter, msg);
+		if (!when || (poller_now - when) >= 15) {
+			g_hash_table_insert(__log_limiter, g_string_chunk_insert(__log_limiter_strings,
+						msg), (void *) poller_now);
+			__log_limiter_count++;
+			when = 0;
+		}
+
+		mutex_unlock(&__log_limiter_lock);
+
+		if (when)
+			goto out;
+	}
+
 	piece = msg;
 
 	while (ret > MAX_LOG_LINE_LENGTH) {
@@ -133,7 +166,13 @@ void ilog(int prio, const char *fmt, ...) {
 
 	write_log(xprio, "%s%s%s", prefix, infix, piece);
 
+out:
 	free(msg);
 }
 
 
+void log_init() {
+	mutex_init(&__log_limiter_lock);
+	__log_limiter = g_hash_table_new(g_str_hash, g_str_equal);
+	__log_limiter_strings = g_string_chunk_new(1024);
+}

daemon/log.h

@@ -42,6 +42,7 @@ extern volatile gint log_level;
 
 
 
+void log_init(void);
 void ilog(int prio, const char *fmt, ...)__attribute__ ((format (printf, 2, 3)));
 
 
@@ -92,6 +93,7 @@ INLINE void log_info_stream_fd(struct stream_fd *sfd) {
 #define LOG_LEVEL_MASK(v)	((v) & 0x0f)
 
 #define LOG_FLAG_RESTORE	0x10
+#define LOG_FLAG_LIMIT		0x20
 
 
 

daemon/main.c

@@ -432,6 +432,7 @@ static void wpidfile(void) {
 static void init_everything() {
 	struct timespec ts;
 
+	log_init();
 	clock_gettime(CLOCK_REALTIME, &ts);
 	srandom(ts.tv_sec ^ ts.tv_nsec);
 	SSL_library_init();

daemon/rtcp.c

@@ -358,7 +358,7 @@ INLINE int check_session_keys(struct crypto_context *c) {
 	return 0;
 
 error:
-	ilog(LOG_ERROR, "%s", err);
+	ilog(LOG_ERROR | LOG_FLAG_LIMIT, "%s", err);
 	return -1;
 }
 
@@ -386,7 +386,7 @@ static int rtcp_payload(struct rtcp_packet **out, str *p, const str *s) {
 
 	return 0;
 error:
-	ilog(LOG_WARNING, "Error parsing RTCP header: %s", err);
+	ilog(LOG_WARNING | LOG_FLAG_LIMIT, "Error parsing RTCP header: %s", err);
 	return -1;
 }
 
@@ -461,7 +461,7 @@ int rtcp_savp2avp(str *s, struct crypto_context *c) {
 	return 0;
 
 error:
-	ilog(LOG_WARNING, "Discarded invalid SRTCP packet: %s", err);
+	ilog(LOG_WARNING | LOG_FLAG_LIMIT, "Discarded invalid SRTCP packet: %s", err);
 	return -1;
 }
 

daemon/rtp.c

@@ -47,7 +47,7 @@ INLINE int check_session_keys(struct crypto_context *c) {
 	return 0;
 
 error:
-	ilog(LOG_ERROR, "%s", err);
+	ilog(LOG_ERROR | LOG_FLAG_LIMIT, "%s", err);
 	return -1;
 }
 
@@ -89,7 +89,7 @@ static int rtp_payload(struct rtp_header **out, str *p, const str *s) {
 	return 0;
 
 error:
-	ilog(LOG_WARNING, "Error parsing RTP header: %s", err);
+	ilog(LOG_WARNING | LOG_FLAG_LIMIT, "Error parsing RTP header: %s", err);
 	return -1;
 }
 
@@ -199,7 +199,7 @@ int rtp_savp2avp(str *s, struct crypto_context *c) {
 	return 0;
 
 error:
-	ilog(LOG_WARNING, "Discarded invalid SRTP packet: authentication failed");
+	ilog(LOG_WARNING | LOG_FLAG_LIMIT, "Discarded invalid SRTP packet: authentication failed");
 	return -1;
 }
 
@@ -239,6 +239,6 @@ int srtp_payloads(str *to_auth, str *to_decrypt, str *auth_tag, str *mki,
 	return 0;
 
 error:
-	ilog(LOG_WARNING, "Invalid SRTP/SRTCP packet received (short packet)");
+	ilog(LOG_WARNING | LOG_FLAG_LIMIT, "Invalid SRTP/SRTCP packet received (short packet)");
 	return -1;
 }