change random number generator

common.cpp

@@ -8,7 +8,8 @@
 #include "common.h"
 #include "log.h"
 
-
+#include <random>
+#include <cmath>
 
 int about_to_exit=0;
 
@@ -28,9 +29,35 @@ int socket_buf_size=1024*1024;
 
 
 
-struct random_fd_t
+struct my_random_t
 {
-	int random_number_fd;
+    std::random_device rd;
+    std::mt19937 gen;
+    std::uniform_int_distribution<u64_t> dis64;
+    std::uniform_int_distribution<u32_t> dis32;
+
+    std::uniform_int_distribution<unsigned char> dis8;
+
+    my_random_t()
+	{
+    	std::mt19937 gen_tmp(rd());
+    	gen=gen_tmp;
+    	gen.discard(700000);  //magic
+	}
+    u64_t gen64()
+    {
+    	return dis64(gen);
+    }
+    u32_t gen32()
+    {
+    	return dis32(gen);
+    }
+
+    unsigned char gen8()
+    {
+    	return dis8(gen);
+    }
+	/*int random_number_fd;
 	random_fd_t()
 	{
 			random_number_fd=open("/dev/urandom",O_RDONLY);
@@ -45,8 +72,39 @@ struct random_fd_t
 	int get_fd()
 	{
 		return random_number_fd;
+	}*/
+}my_random;
+
+void get_fake_random_chars(char * s,int len)
+{
+	char *p=s;
+	int left=len;
+
+	while(left>=(int)sizeof(u64_t))
+	{
+		*((u64_t*)p)=my_random.gen64();  //no endianess problem here  , but may break strict-alias?
+
+		p+=sizeof(u64_t);
+		left-=sizeof(u64_t);
 	}
-}random_fd;
+	if(left)
+	{
+		u64_t tmp=my_random.gen64();
+		memcpy(p,&tmp,left);
+	}
+}
+
+int random_between(u32_t a,u32_t b)
+{
+	if(a>b)
+	{
+		mylog(log_fatal,"min >max?? %d %d\n",a ,b);
+		myexit(1);
+	}
+	if(a==b)return a;
+	else return a+get_fake_random_number()%(b+1-a);
+}
+
 /*
 u64_t get_current_time()//ms
 {
@@ -181,36 +239,36 @@ int clear_iptables_rule()
 
 
 
-u64_t get_true_random_number_64()
+u64_t get_fake_random_number_64()
 {
-	u64_t ret;
+	//u64_t ret;
-	int size=read(random_fd.get_fd(),&ret,sizeof(ret));
+	//int size=read(random_fd.get_fd(),&ret,sizeof(ret));
-	if(size!=sizeof(ret))
+	//if(size!=sizeof(ret))
-	{
+	//{
-		mylog(log_fatal,"get random number failed %d\n",size);
+	//	mylog(log_fatal,"get random number failed %d\n",size);
 
-		myexit(-1);
+	//	myexit(-1);
-	}
+	//}
 
-	return ret;
+	return my_random.gen64();
 }
-u32_t get_true_random_number()
+u32_t get_fake_random_number()
 {
-	u32_t ret;
+	//u32_t ret;
-	int size=read(random_fd.get_fd(),&ret,sizeof(ret));
+	//int size=read(random_fd.get_fd(),&ret,sizeof(ret));
-	if(size!=sizeof(ret))
+	//if(size!=sizeof(ret))
-	{
+	//{
-		mylog(log_fatal,"get random number failed %d\n",size);
+	//	mylog(log_fatal,"get random number failed %d\n",size);
-		myexit(-1);
+	//	myexit(-1);
-	}
+	//}
-	return ret;
+	return my_random.gen32();
 }
-u32_t get_true_random_number_nz() //nz for non-zero
+u32_t get_fake_random_number_nz() //nz for non-zero
 {
 	u32_t ret=0;
 	while(ret==0)
 	{
-		ret=get_true_random_number();
+		ret=get_fake_random_number();
 	}
 	return ret;
 }
@@ -446,26 +504,8 @@ bool larger_than_u16(uint16_t a,uint16_t b)
 	}
 }
 
-void get_true_random_chars(char * s,int len)
-{
-	int size=read(random_fd.get_fd(),s,len);
-	if(size!=len)
-	{
-		printf("get random number failed\n");
-		exit(-1);
-	}
-}
 
-int random_between(u32_t a,u32_t b)
+
-{
-	if(a>b)
-	{
-		mylog(log_fatal,"min >max?? %d %d\n",a ,b);
-		myexit(1);
-	}
-	if(a==b)return a;
-	else return a+get_true_random_number()%(b+1-a);
-}
 
 /*
 int set_timer_ms(int epollfd,int &timer_fd,u32_t timer_interval)

common.h

@@ -58,7 +58,7 @@ typedef int i32_t;
 typedef unsigned short u16_t;
 typedef short i16_t;
 
-struct itimerspec {
+struct my_itimerspec {
 	struct timespec it_interval;  /* Timer interval */
 	struct timespec it_value;     /* Initial expiration */
 };
@@ -209,9 +209,9 @@ char * my_ntoa(u32_t ip);
 
 void myexit(int a);
 void init_random_number_fd();
-u64_t get_true_random_number_64();
+u64_t get_fake_random_number_64();
-u32_t get_true_random_number();
+u32_t get_fake_random_number();
-u32_t get_true_random_number_nz();
+u32_t get_fake_random_number_nz();
 u64_t ntoh64(u64_t a);
 u64_t hton64(u64_t a);
 bool larger_than_u16(uint16_t a,uint16_t b);
@@ -231,7 +231,7 @@ void myexit(int a);
 int add_iptables_rule(char *);
 
 int clear_iptables_rule();
-void get_true_random_chars(char * s,int len);
+void get_fake_random_chars(char * s,int len);
 int random_between(u32_t a,u32_t b);
 
 int set_timer_ms(int epollfd,int &timer_fd,u32_t timer_interval);

connection.cpp

@@ -74,10 +74,10 @@ void conv_manager_t::clear()
 }
 u32_t conv_manager_t::get_new_conv()
 {
-	u32_t conv=get_true_random_number_nz();
+	u32_t conv=get_fake_random_number_nz();
 	while(conv_to_u64.find(conv)!=conv_to_u64.end())
 	{
-		conv=get_true_random_number_nz();
+		conv=get_fake_random_number_nz();
 	}
 	return conv;
 }

fec_manager.h

@@ -179,7 +179,7 @@ public:
 			loop=0;
 			cb=0;
 		}
-		seq=(u32_t)get_true_random_number(); //TODO temp solution for a bug.
+		seq=(u32_t)get_fake_random_number(); //TODO temp solution for a bug.
 
 		return 0;
 	}

main.cpp

@@ -92,8 +92,11 @@ void sigint_cb(struct ev_loop *l, ev_signal *w, int revents)
 }
 
 
+
 int main(int argc, char *argv[])
 {
+	unit_test();
+
 	struct ev_loop* loop=ev_default_loop(0);
     ev_signal signal_watcher_sigpipe;
     ev_signal_init(&signal_watcher_sigpipe, sigpipe_cb, SIGPIPE);
@@ -142,7 +145,7 @@ int main(int argc, char *argv[])
 
 	if(strlen(tun_dev)==0)
 	{
-		sprintf(tun_dev,"tun%u",get_true_random_number()%1000);
+		sprintf(tun_dev,"tun%u",get_fake_random_number()%1000);
 	}
 
 	if(client_or_server==client_mode)

misc.cpp

@@ -242,7 +242,7 @@ int delay_send(my_time_t delay,const dest_t &dest,char *data,int len)
 	//mylog(log_info,"rand = %d\n",rand);
 
 	if (dest.cook&&random_drop != 0) {
-		if (get_true_random_number() % 10000 < (u32_t) random_drop) {
+		if (get_fake_random_number() % 10000 < (u32_t) random_drop) {
 			return 0;
 		}
 	}
@@ -330,6 +330,38 @@ int handle_command(char *s)
 
 int unit_test()
 {
+
+	{
+		union test_t
+		{
+			u64_t u64;
+			char arry[8];
+		}test111;
+
+		assert((void*)&test111.u64==(void*)&test111.arry[0]);
+		//printf("%llx,%llx\n",&ttt.u64,&ttt.arry[0]);
+
+		printf("%llx\n",get_fake_random_number_64());
+		printf("%llx\n",get_fake_random_number_64());
+		printf("%llx\n",get_fake_random_number_64());
+
+		printf("%x\n",get_fake_random_number());
+		printf("%x\n",get_fake_random_number());
+		printf("%x\n",get_fake_random_number());
+
+		char buf[10];
+		get_fake_random_chars(buf,10);
+		for(int i=0;i<10;i++)
+			printf("<%d>",(int)buf[i]);
+		printf("\n");
+
+		get_fake_random_chars(buf,10);
+		for(int i=0;i<10;i++)
+			printf("<%d>",(int)buf[i]);
+		printf("\n");
+	}
+
+
 	int i,j,k;
 	void *code=fec_new(3,6);
 	char arr[6][100]=
@@ -543,6 +575,7 @@ int unit_test()
 
 	}
 
+
 	return 0;
 }
 

packet.cpp

@@ -61,7 +61,7 @@ int do_obscure_old(const char * input, int in_len,char *output,int &out_len)
 	if (in_len > 65535||in_len<0)
 		return -1;
 	int iv_len=iv_min+rand()%(iv_max-iv_min);
-	get_true_random_chars(output,iv_len);
+	get_fake_random_chars(output,iv_len);
 	memcpy(output+iv_len,input,in_len);
 
 	output[iv_len+in_len]=(uint8_t)iv_len;
@@ -88,7 +88,7 @@ int do_obscure(char * data,int &len)
 	assert(len<buf_len);
 
 	int iv_len=random_between(iv_min,iv_max);
-	get_true_random_chars(data+len,iv_len);
+	get_fake_random_chars(data+len,iv_len);
 	data[iv_len+len]=(uint8_t)iv_len;
 	for(int i=0,j=0;i<len;i++,j++)
 	{