[PATCH] rename net_random to random32

Make net_random() more widely available by calling it random32

akpm: hopefully this will permit the removal of carta_random32.  That needs
confirmation from Stephane - this code looks somewhat more computationally
expensive, and has a different (ie: callee-stateful) interface.

[akpm@osdl.org: lots of build fixes, cleanups]
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Stephane Eranian <eranian@hpl.hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/linux/net.h

@@ -19,6 +19,7 @@
 #define _LINUX_NET_H
 
 #include <linux/wait.h>
+#include <linux/random.h>
 #include <asm/socket.h>
 
 struct poll_table_struct;
@@ -193,9 +194,9 @@ extern int 	     sock_map_fd(struct socket *sock);
 extern struct socket *sockfd_lookup(int fd, int *err);
 #define		     sockfd_put(sock) fput(sock->file)
 extern int	     net_ratelimit(void);
-extern unsigned long net_random(void);
+
-extern void	     net_srandom(unsigned long);
+#define net_random()		random32()
-extern void	     net_random_init(void);
+#define net_srandom(seed)	srandom32(seed)
 
 extern int   	     kernel_sendmsg(struct socket *sock, struct msghdr *msg,
 				    struct kvec *vec, size_t num, size_t len);

include/linux/random.h

@@ -69,6 +69,9 @@ extern struct file_operations random_fops, urandom_fops;
 unsigned int get_random_int(void);
 unsigned long randomize_range(unsigned long start, unsigned long end, unsigned long len);
 
+u32 random32(void);
+void srandom32(u32 seed);
+
 #endif /* __KERNEL___ */
 
 #endif /* _LINUX_RANDOM_H */

lib/Makefile

@@ -12,7 +12,7 @@ lib-$(CONFIG_SMP) += cpumask.o
 
 lib-y	+= kobject.o kref.o kobject_uevent.o klist.o
 
-obj-y += sort.o parser.o halfmd4.o iomap_copy.o debug_locks.o
+obj-y += sort.o parser.o halfmd4.o iomap_copy.o debug_locks.o random32.o
 
 ifeq ($(CONFIG_DEBUG_KOBJECT),y)
 CFLAGS_kobject.o += -DDEBUG

lib/random32.c

@@ -0,0 +1,142 @@
+/*
+  This is a maximally equidistributed combined Tausworthe generator
+  based on code from GNU Scientific Library 1.5 (30 Jun 2004)
+
+   x_n = (s1_n ^ s2_n ^ s3_n)
+
+   s1_{n+1} = (((s1_n & 4294967294) <<12) ^ (((s1_n <<13) ^ s1_n) >>19))
+   s2_{n+1} = (((s2_n & 4294967288) << 4) ^ (((s2_n << 2) ^ s2_n) >>25))
+   s3_{n+1} = (((s3_n & 4294967280) <<17) ^ (((s3_n << 3) ^ s3_n) >>11))
+
+   The period of this generator is about 2^88.
+
+   From: P. L'Ecuyer, "Maximally Equidistributed Combined Tausworthe
+   Generators", Mathematics of Computation, 65, 213 (1996), 203--213.
+
+   This is available on the net from L'Ecuyer's home page,
+
+   http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
+   ftp://ftp.iro.umontreal.ca/pub/simulation/lecuyer/papers/tausme.ps
+
+   There is an erratum in the paper "Tables of Maximally
+   Equidistributed Combined LFSR Generators", Mathematics of
+   Computation, 68, 225 (1999), 261--269:
+   http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
+
+        ... the k_j most significant bits of z_j must be non-
+        zero, for each j. (Note: this restriction also applies to the
+        computer code given in [4], but was mistakenly not mentioned in
+        that paper.)
+
+   This affects the seeding procedure by imposing the requirement
+   s1 > 1, s2 > 7, s3 > 15.
+
+*/
+
+#include <linux/types.h>
+#include <linux/percpu.h>
+#include <linux/module.h>
+#include <linux/random.h>
+
+struct rnd_state {
+	u32 s1, s2, s3;
+};
+
+static DEFINE_PER_CPU(struct rnd_state, net_rand_state);
+
+static u32 __random32(struct rnd_state *state)
+{
+#define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b)
+
+	state->s1 = TAUSWORTHE(state->s1, 13, 19, 4294967294UL, 12);
+	state->s2 = TAUSWORTHE(state->s2, 2, 25, 4294967288UL, 4);
+	state->s3 = TAUSWORTHE(state->s3, 3, 11, 4294967280UL, 17);
+
+	return (state->s1 ^ state->s2 ^ state->s3);
+}
+
+static void __set_random32(struct rnd_state *state, unsigned long s)
+{
+	if (s == 0)
+		s = 1;      /* default seed is 1 */
+
+#define LCG(n) (69069 * n)
+	state->s1 = LCG(s);
+	state->s2 = LCG(state->s1);
+	state->s3 = LCG(state->s2);
+
+	/* "warm it up" */
+	__random32(state);
+	__random32(state);
+	__random32(state);
+	__random32(state);
+	__random32(state);
+	__random32(state);
+}
+
+/**
+ *	random32 - pseudo random number generator
+ *
+ *	A 32 bit pseudo-random number is generated using a fast
+ *	algorithm suitable for simulation. This algorithm is NOT
+ *	considered safe for cryptographic use.
+ */
+u32 random32(void)
+{
+	unsigned long r;
+	struct rnd_state *state = &get_cpu_var(net_rand_state);
+	r = __random32(state);
+	put_cpu_var(state);
+	return r;
+}
+EXPORT_SYMBOL(random32);
+
+/**
+ *	srandom32 - add entropy to pseudo random number generator
+ *	@seed: seed value
+ *
+ *	Add some additional seeding to the random32() pool.
+ *	Note: this pool is per cpu so it only affects current CPU.
+ */
+void srandom32(u32 entropy)
+{
+	struct rnd_state *state = &get_cpu_var(net_rand_state);
+	__set_random32(state, state->s1 ^ entropy);
+	put_cpu_var(state);
+}
+EXPORT_SYMBOL(srandom32);
+
+/*
+ *	Generate some initially weak seeding values to allow
+ *	to start the random32() engine.
+ */
+static int __init random32_init(void)
+{
+	int i;
+
+	for_each_possible_cpu(i) {
+		struct rnd_state *state = &per_cpu(net_rand_state,i);
+		__set_random32(state, i + jiffies);
+	}
+	return 0;
+}
+core_initcall(random32_init);
+
+/*
+ *	Generate better values after random number generator
+ *	is fully initalized.
+ */
+static int __init random32_reseed(void)
+{
+	int i;
+	unsigned long seed;
+
+	for_each_possible_cpu(i) {
+		struct rnd_state *state = &per_cpu(net_rand_state,i);
+
+		get_random_bytes(&seed, sizeof(seed));
+		__set_random32(state, seed);
+	}
+	return 0;
+}
+late_initcall(random32_reseed);

net/core/dev.c

@@ -3502,8 +3502,6 @@ static int __init net_dev_init(void)
 
 	BUG_ON(!dev_boot_phase);
 
-	net_random_init();
-
 	if (dev_proc_init())
 		goto out;
 

net/core/utils.c

@@ -30,119 +30,6 @@
 #include <asm/system.h>
 #include <asm/uaccess.h>
 
-/*
-  This is a maximally equidistributed combined Tausworthe generator
-  based on code from GNU Scientific Library 1.5 (30 Jun 2004)
-
-   x_n = (s1_n ^ s2_n ^ s3_n) 
-
-   s1_{n+1} = (((s1_n & 4294967294) <<12) ^ (((s1_n <<13) ^ s1_n) >>19))
-   s2_{n+1} = (((s2_n & 4294967288) << 4) ^ (((s2_n << 2) ^ s2_n) >>25))
-   s3_{n+1} = (((s3_n & 4294967280) <<17) ^ (((s3_n << 3) ^ s3_n) >>11))
-
-   The period of this generator is about 2^88.
-
-   From: P. L'Ecuyer, "Maximally Equidistributed Combined Tausworthe
-   Generators", Mathematics of Computation, 65, 213 (1996), 203--213.
-
-   This is available on the net from L'Ecuyer's home page,
-
-   http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
-   ftp://ftp.iro.umontreal.ca/pub/simulation/lecuyer/papers/tausme.ps 
-
-   There is an erratum in the paper "Tables of Maximally
-   Equidistributed Combined LFSR Generators", Mathematics of
-   Computation, 68, 225 (1999), 261--269:
-   http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
-
-        ... the k_j most significant bits of z_j must be non-
-        zero, for each j. (Note: this restriction also applies to the 
-        computer code given in [4], but was mistakenly not mentioned in
-        that paper.)
-   
-   This affects the seeding procedure by imposing the requirement
-   s1 > 1, s2 > 7, s3 > 15.
-
-*/
-struct nrnd_state {
-	u32 s1, s2, s3;
-};
-
-static DEFINE_PER_CPU(struct nrnd_state, net_rand_state);
-
-static u32 __net_random(struct nrnd_state *state)
-{
-#define TAUSWORTHE(s,a,b,c,d) ((s&c)<<d) ^ (((s <<a) ^ s)>>b)
-
-	state->s1 = TAUSWORTHE(state->s1, 13, 19, 4294967294UL, 12);
-	state->s2 = TAUSWORTHE(state->s2, 2, 25, 4294967288UL, 4);
-	state->s3 = TAUSWORTHE(state->s3, 3, 11, 4294967280UL, 17);
-
-	return (state->s1 ^ state->s2 ^ state->s3);
-}
-
-static void __net_srandom(struct nrnd_state *state, unsigned long s)
-{
-	if (s == 0)
-		s = 1;      /* default seed is 1 */
-
-#define LCG(n) (69069 * n)
-	state->s1 = LCG(s);
-	state->s2 = LCG(state->s1);
-	state->s3 = LCG(state->s2);
-
-	/* "warm it up" */
-	__net_random(state);
-	__net_random(state);
-	__net_random(state);
-	__net_random(state);
-	__net_random(state);
-	__net_random(state);
-}
-
-
-unsigned long net_random(void)
-{
-	unsigned long r;
-	struct nrnd_state *state = &get_cpu_var(net_rand_state);
-	r = __net_random(state);
-	put_cpu_var(state);
-	return r;
-}
-
-
-void net_srandom(unsigned long entropy)
-{
-	struct nrnd_state *state = &get_cpu_var(net_rand_state);
-	__net_srandom(state, state->s1^entropy);
-	put_cpu_var(state);
-}
-
-void __init net_random_init(void)
-{
-	int i;
-
-	for_each_possible_cpu(i) {
-		struct nrnd_state *state = &per_cpu(net_rand_state,i);
-		__net_srandom(state, i+jiffies);
-	}
-}
-
-static int net_random_reseed(void)
-{
-	int i;
-	unsigned long seed;
-
-	for_each_possible_cpu(i) {
-		struct nrnd_state *state = &per_cpu(net_rand_state,i);
-
-		get_random_bytes(&seed, sizeof(seed));
-		__net_srandom(state, seed);
-	}
-	return 0;
-}
-late_initcall(net_random_reseed);
-
 int net_msg_cost = 5*HZ;
 int net_msg_burst = 10;
 
@@ -153,10 +40,7 @@ int net_ratelimit(void)
 {
 	return __printk_ratelimit(net_msg_cost, net_msg_burst);
 }
-
-EXPORT_SYMBOL(net_random);
 EXPORT_SYMBOL(net_ratelimit);
-EXPORT_SYMBOL(net_srandom);
 
 /*
  * Convert an ASCII string to binary IP.