A new bif unique_id(prefix) that returns a string that's unique across

Bro instaces with high probablity.

"prefix" is a string that will be prepended to the returned ID.

src/Conn.cc

@@ -216,56 +216,6 @@ Connection::~Connection()
 		--external_connections;
 	}
 
-uint64 Connection::uid_counter = 0;
-uint64 Connection::uid_instance = 0;
-
-uint64 Connection::CalculateNextUID()
-	{
-	if ( uid_instance == 0 )
-		{
-		// This is the first time we need a UID.
-
-		if ( ! have_random_seed() )
-			{
-			// If we don't need deterministic output (as
-			// indicated by a set seed), we calculate the
-			// instance ID by hashing something likely to be
-			// globally unique.
-			struct {
-				char hostname[128];
-				struct timeval time;
-				pid_t pid;
-				int rnd;
-			} unique;
-
-			gethostname(unique.hostname, 128);
-			unique.hostname[sizeof(unique.hostname)-1] = '\0';
-			gettimeofday(&unique.time, 0);
-			unique.pid = getpid();
-			unique.rnd = bro_random();
-
-			uid_instance = HashKey::HashBytes(&unique, sizeof(unique));
-			++uid_instance; // Now it's larger than zero.
-			}
-
-		else
-			// Generate determistic UIDs.
-			uid_instance = 1;
-		}
-
-	// Now calculate the unique ID for this connection.
-	struct {
-		uint64 counter;
-		hash_t instance;
-	} key;
-
-	key.counter = ++uid_counter;
-	key.instance = uid_instance;
-
-	uint64_t h = HashKey::HashBytes(&key, sizeof(key));
-	return h;
-	}
-
 void Connection::Done()
 	{
 	finished = 1;
@@ -417,7 +367,7 @@ RecordVal* Connection::BuildConnVal()
 		conn_val->Assign(8, new StringVal(""));	// history
 
 		if ( ! uid )
-			uid = CalculateNextUID();
+			uid = calculate_unique_id();
 
 		char tmp[20];
 		conn_val->Assign(9, new StringVal(uitoa_n(uid, tmp, sizeof(tmp), 62)));

src/Conn.h

@@ -303,8 +303,6 @@ public:
 
 	void SetUID(uint64 arg_uid)	 { uid = arg_uid; }
 
-	static uint64 CalculateNextUID();
-
 protected:
 
 	Connection()	{ persistent = 0; }
@@ -363,9 +361,6 @@ protected:
 	PIA* primary_PIA;
 
 	uint64 uid;	// Globally unique connection ID.
-
-	static uint64 uid_counter;	// Counter for uids.
-	static uint64 uid_instance;	// Instance ID, computed once.
 };
 
 class ConnectionTimer : public Timer {

src/ConnCompressor.cc

@@ -620,7 +620,7 @@ void ConnCompressor::PktHdrToPendingConn(double time, const HashKey* key,
 	c->FIN = (tp->th_flags & TH_FIN) != 0;
 	c->RST = (tp->th_flags & TH_RST) != 0;
 	c->ACK = (tp->th_flags & TH_ACK) != 0;
-	c->uid = Connection::CalculateNextUID();
+	c->uid = calculate_unique_id();
 	c->num_bytes_ip = ip->TotalLen();
 	c->num_pkts = 1;
 	c->invalid = 0;

src/bro.bif

@@ -3349,6 +3349,12 @@ function bro_has_ipv6%(%) : bool
 #endif
     %}
 
+function unique_id%(prefix: string%) : bool
+	%{
+	char tmp[20];
+	uint64 uid = calculate_unique_id();
+	return new StringVal(uitoa_n(uid, tmp, sizeof(tmp), 62, prefix->CheckString()));
+	%}
 
 %%{
 #include <openssl/x509.h>

src/util.cc

@@ -344,15 +344,27 @@ template<class T> int atoi_n(int len, const char* s, const char** end, int base,
 template int atoi_n<int>(int len, const char* s, const char** end, int base, int& result);
 template int atoi_n<int64_t>(int len, const char* s, const char** end, int base, int64_t& result);
 
-char* uitoa_n(uint64 value, char* str, int n, int base)
+char* uitoa_n(uint64 value, char* str, int n, int base, const char* prefix)
 	{
 	static char dig[] = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
 
+	assert(n);
+
 	int i = 0;
 	uint64 v;
 	char* p, *q;
 	char c;
 
+	if ( prefix ) 
+		{
+		strncpy(str, prefix, n);
+		str[n-1] = '\0';
+		i += strlen(prefix);
+		}
+
+	if ( i >= n )
+		return str;
+
 	v = value;
 
 	do {
@@ -1122,6 +1134,56 @@ int time_compare(struct timeval* tv_a, struct timeval* tv_b)
 		return tv_a->tv_sec - tv_b->tv_sec;
 	}
 
+static uint64 uid_counter;	// Counter for unique IDs.
+static uint64 uid_instance;	// Instance ID, computed once.
+
+uint64 calculate_unique_id()
+	{
+	if ( uid_instance == 0 )
+		{
+		// This is the first time we need a UID.
+
+		if ( ! have_random_seed() )
+			{
+			// If we don't need deterministic output (as
+			// indicated by a set seed), we calculate the
+			// instance ID by hashing something likely to be
+			// globally unique.
+			struct {
+				char hostname[128];
+				struct timeval time;
+				pid_t pid;
+				int rnd;
+			} unique;
+
+			gethostname(unique.hostname, 128);
+			unique.hostname[sizeof(unique.hostname)-1] = '\0';
+			gettimeofday(&unique.time, 0);
+			unique.pid = getpid();
+			unique.rnd = bro_random();
+
+			uid_instance = HashKey::HashBytes(&unique, sizeof(unique));
+			++uid_instance; // Now it's larger than zero.
+			}
+
+		else
+			// Generate determistic UIDs.
+			uid_instance = 1;
+		}
+
+	// Now calculate the unique ID.
+	struct {
+		uint64 counter;
+		hash_t instance;
+	} key;
+
+	key.counter = ++uid_counter;
+	key.instance = uid_instance;
+
+	uint64_t h = HashKey::HashBytes(&key, sizeof(key));
+	return h;
+	}
+
 void out_of_memory(const char* where)
 	{
 	fprintf( stderr, "bro: out of memory in %s.\n", where );

src/util.h

@@ -111,7 +111,7 @@ extern char* strcasestr(const char* s, const char* find);
 #endif
 extern const char* strpbrk_n(size_t len, const char* s, const char* charset);
 template<class T> int atoi_n(int len, const char* s, const char** end, int base, T& result);
-extern char* uitoa_n(uint64 value, char* str, int n, int base);
+extern char* uitoa_n(uint64 value, char* str, int n, int base, const char* prefix=0);
 int strstr_n(const int big_len, const unsigned char* big,
 		const int little_len, const unsigned char* little);
 extern int fputs(int len, const char* s, FILE* fp);
@@ -233,6 +233,10 @@ extern struct timeval double_to_timeval(double t);
 // Return > 0 if tv_a > tv_b, 0 if equal, < 0 if tv_a < tv_b.
 extern int time_compare(struct timeval* tv_a, struct timeval* tv_b);
 
+// Returns an integer that's very likely to be unique, even across Bro
+// instances.
+extern uint64 calculate_unique_id();
+
 // For now, don't use hash_maps - they're not fully portable.
 #if 0
 // Use for hash_map's string keys.

testing/btest/Baseline/bifs.unique_id-rnd/count

@@ -0,0 +1 @@
+6

testing/btest/Baseline/bifs.unique_id/out

@@ -0,0 +1,3 @@
+A-UWkUyAuUGXf
+B-56gKBmhBBB6
+C-50da4BEzauh

testing/btest/bifs/unique_id-rnd.bro

@@ -0,0 +1,9 @@
+#
+# @TEST-EXEC: BRO_SEED_FILE= bro %INPUT 2>/dev/null >out
+# @TEST-EXEC: BRO_SEED_FILE= bro %INPUT 2>/dev/null >>out
+# @TEST-EXEC: cat out | sort | uniq | wc -l >count
+# @TEST-EXEC: btest-diff count
+
+print unique_id("A-");
+print unique_id("B-");
+print unique_id("C-");

testing/btest/bifs/unique_id.bro

@@ -0,0 +1,7 @@
+#
+# @TEST-EXEC: bro %INPUT >out
+# @TEST-EXEC: btest-diff out
+
+print unique_id("A-");
+print unique_id("B-");
+print unique_id("C-");