net: use common rand()/srand() functions

Replace rand() with the functions from lib/. The link-local network code stores its own seed, derived from the MAC address. Thus making it independent from calls to srand() in other modules. Signed-off-by: Michael Walle <michael@walle.cc> Acked-by: Joe Hershberger <joe.hershberger@ni.com>

net: use common rand()/srand() functions
Replace rand() with the functions from lib/. The link-local network code stores its own seed, derived from the MAC address. Thus making it independent from calls to srand() in other modules. Signed-off-by: Michael Walle <michael@walle.cc> Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Michael Walle · Albert ARIBAUD
1 parent 9acf1ca50d
Showing 6 changed files with 34 additions and 82 deletions Side-by-side Diff
include/common.h
lib/Makefile
net/Makefile
net/link_local.c
net/net_rand.c
net/net_rand.h
@@ -761,7 +761,9 @@
 #include <u-boot/crc.h>
  
 /* lib/rand.c */
-#ifdef CONFIG_RANDOM_MACADDR
+#if defined(CONFIG_RANDOM_MACADDR) || \
+	defined(CONFIG_BOOTP_RANDOM_DELAY) || \
+	defined(CONFIG_CMD_LINK_LOCAL)
 #define RAND_MAX -1U
 void srand(unsigned int seed);
 unsigned int rand(void);
@@ -67,8 +67,10 @@
 COBJS-$(CONFIG_BOOTP_PXE) += uuid.o
 COBJS-y += vsprintf.o
 COBJS-$(CONFIG_RANDOM_MACADDR) += rand.o
+COBJS-$(CONFIG_BOOTP_RANDOM_DELAY) += rand.o
+COBJS-$(CONFIG_CMD_LINK_LOCAL) += rand.o
  
-COBJS	:= $(COBJS-y)
+COBJS	:= $(sort $(COBJS-y))
 SRCS	:= $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS))
  
@@ -34,8 +34,6 @@
 COBJS-$(CONFIG_CMD_NET)  += eth.o
 COBJS-$(CONFIG_CMD_LINK_LOCAL) += link_local.o
 COBJS-$(CONFIG_CMD_NET)  += net.o
-COBJS-$(CONFIG_BOOTP_RANDOM_DELAY) += net_rand.o
-COBJS-$(CONFIG_CMD_LINK_LOCAL) += net_rand.o
 COBJS-$(CONFIG_CMD_NFS)  += nfs.o
 COBJS-$(CONFIG_CMD_PING) += ping.o
 COBJS-$(CONFIG_CMD_RARP) += rarp.o
@@ -56,6 +56,7 @@
 static unsigned nprobes;
 static unsigned nclaims;
 static int ready;
+static unsigned int seed;
  
 static void link_local_timeout(void);
  
@@ -68,7 +69,7 @@
 	unsigned tmp;
  
 	do {
-		tmp = rand() & IN_CLASSB_HOST;
+		tmp = rand_r(&seed) & IN_CLASSB_HOST;
 	} while (tmp > (IN_CLASSB_HOST - 0x0200));
 	return (IPaddr_t) htonl((LINKLOCAL_ADDR + 0x0100) + tmp);
 }
@@ -78,7 +79,7 @@
  */
 static inline unsigned random_delay_ms(unsigned secs)
 {
-	return rand() % (secs * 1000);
+	return rand_r(&seed) % (secs * 1000);
 }
  
 static void configure_wait(void)
@@ -109,7 +110,7 @@
 	}
 	NetOurSubnetMask = IN_CLASSB_NET;
  
-	srand_mac();
+	seed = seed_mac();
 	if (ip == 0)
 		ip = pick();
  
-/*
- *	Based on LiMon - BOOTP.
- *
- *	Copyright 1994, 1995, 2000 Neil Russell.
- *	(See License)
- *	Copyright 2000 Roland Borde
- *	Copyright 2000 Paolo Scaffardi
- *	Copyright 2000-2004 Wolfgang Denk, wd@denx.de
- */
-
-#include <common.h>
-#include <net.h>
-#include "net_rand.h"
-
-static ulong seed1, seed2;
-
-void srand_mac(void)
-{
-	ulong tst1, tst2, m_mask;
-	ulong m_value = 0;
-	int reg;
-	unsigned char bi_enetaddr[6];
-
-	/* get our mac */
-	eth_getenv_enetaddr("ethaddr", bi_enetaddr);
-
-	debug("BootpRequest => Our Mac: ");
-	for (reg = 0; reg < 6; reg++)
-		debug("%x%c", bi_enetaddr[reg], reg == 5 ? '\n' : ':');
-
-	/* Mac-Manipulation 2 get seed1 */
-	tst1 = 0;
-	tst2 = 0;
-	for (reg = 2; reg < 6; reg++) {
-		tst1 = tst1 << 8;
-		tst1 = tst1 | bi_enetaddr[reg];
-	}
-	for (reg = 0; reg < 2; reg++) {
-		tst2 = tst2 | bi_enetaddr[reg];
-		tst2 = tst2 << 8;
-	}
-
-	seed1 = tst1^tst2;
-
-	/* Mirror seed1*/
-	m_mask = 0x1;
-	for (reg = 1; reg <= 32; reg++) {
-		m_value |= (m_mask & seed1);
-		seed1 = seed1 >> 1;
-		m_value = m_value << 1;
-	}
-	seed1 = m_value;
-	seed2 = 0xb78d0945;
-}
-
-unsigned long rand(void)
-{
-	ulong sum;
-
-	/* Random Number Generator */
-	sum = seed1 + seed2;
-	if (sum < seed1 || sum < seed2)
-		sum++;
-	seed2 = seed1;
-	seed1 = sum;
-
-	return sum;
-}
@@ -9,19 +9,36 @@
 #ifndef __NET_RAND_H__
 #define __NET_RAND_H__
  
-#define RAND_MAX 0xffffffff
+#include <common.h>
  
 /*
- * Seed the random number generator using the eth0 MAC address
+ * Return a seed for the PRNG derived from the eth0 MAC address.
  */
-void srand_mac(void);
+static inline unsigned int seed_mac(void)
+{
+	unsigned char enetaddr[6];
+	unsigned int seed;
  
+	/* get our mac */
+	eth_getenv_enetaddr("ethaddr", enetaddr);
+
+	seed = enetaddr[5];
+	seed ^= enetaddr[4] << 8;
+	seed ^= enetaddr[3] << 16;
+	seed ^= enetaddr[2] << 24;
+	seed ^= enetaddr[1];
+	seed ^= enetaddr[0] << 8;
+
+	return seed;
+}
+
 /*
- * Get a random number (after seeding with MAC address)
- *
- * @return random number
+ * Seed the random number generator using the eth0 MAC address.
  */
-unsigned long rand(void);
+static inline void srand_mac(void)
+{
+	srand(seed_mac());
+}
  
 #endif /* __NET_RAND_H__ */
...	...	@@ -761,7 +761,9 @@
761	761	#include <u-boot/crc.h>
762	762
763	763	/* lib/rand.c */
764		-#ifdef CONFIG_RANDOM_MACADDR
	764	+#if defined(CONFIG_RANDOM_MACADDR) \|\| \
	765	+ defined(CONFIG_BOOTP_RANDOM_DELAY) \|\| \
	766	+ defined(CONFIG_CMD_LINK_LOCAL)
765	767	#define RAND_MAX -1U
766	768	void srand(unsigned int seed);
767	769	unsigned int rand(void);
...	...	@@ -67,8 +67,10 @@
67	67	COBJS-$(CONFIG_BOOTP_PXE) += uuid.o
68	68	COBJS-y += vsprintf.o
69	69	COBJS-$(CONFIG_RANDOM_MACADDR) += rand.o
	70	+COBJS-$(CONFIG_BOOTP_RANDOM_DELAY) += rand.o
	71	+COBJS-$(CONFIG_CMD_LINK_LOCAL) += rand.o
70	72
71		-COBJS := $(COBJS-y)
	73	+COBJS := $(sort $(COBJS-y))
72	74	SRCS := $(COBJS:.o=.c)
73	75	OBJS := $(addprefix $(obj),$(COBJS))
74	76
...	...	@@ -34,8 +34,6 @@
34	34	COBJS-$(CONFIG_CMD_NET) += eth.o
35	35	COBJS-$(CONFIG_CMD_LINK_LOCAL) += link_local.o
36	36	COBJS-$(CONFIG_CMD_NET) += net.o
37		-COBJS-$(CONFIG_BOOTP_RANDOM_DELAY) += net_rand.o
38		-COBJS-$(CONFIG_CMD_LINK_LOCAL) += net_rand.o
39	37	COBJS-$(CONFIG_CMD_NFS) += nfs.o
40	38	COBJS-$(CONFIG_CMD_PING) += ping.o
41	39	COBJS-$(CONFIG_CMD_RARP) += rarp.o
...	...	@@ -56,6 +56,7 @@
56	56	static unsigned nprobes;
57	57	static unsigned nclaims;
58	58	static int ready;
	59	+static unsigned int seed;
59	60
60	61	static void link_local_timeout(void);
61	62
...	...	@@ -68,7 +69,7 @@
68	69	unsigned tmp;
69	70
70	71	do {
71		- tmp = rand() & IN_CLASSB_HOST;
	72	+ tmp = rand_r(&seed) & IN_CLASSB_HOST;
72	73	} while (tmp > (IN_CLASSB_HOST - 0x0200));
73	74	return (IPaddr_t) htonl((LINKLOCAL_ADDR + 0x0100) + tmp);
74	75	}
...	...	@@ -78,7 +79,7 @@
78	79	*/
79	80	static inline unsigned random_delay_ms(unsigned secs)
80	81	{
81		- return rand() % (secs * 1000);
	82	+ return rand_r(&seed) % (secs * 1000);
82	83	}
83	84
84	85	static void configure_wait(void)
...	...	@@ -109,7 +110,7 @@
109	110	}
110	111	NetOurSubnetMask = IN_CLASSB_NET;
111	112
112		- srand_mac();
	113	+ seed = seed_mac();
113	114	if (ip == 0)
114	115	ip = pick();
115	116
1		-/*
2		- * Based on LiMon - BOOTP.
3		- *
4		- * Copyright 1994, 1995, 2000 Neil Russell.
5		- * (See License)
6		- * Copyright 2000 Roland Borde
7		- * Copyright 2000 Paolo Scaffardi
8		- * Copyright 2000-2004 Wolfgang Denk, wd@denx.de
9		- */
10		-
11		-#include <common.h>
12		-#include <net.h>
13		-#include "net_rand.h"
14		-
15		-static ulong seed1, seed2;
16		-
17		-void srand_mac(void)
18		-{
19		- ulong tst1, tst2, m_mask;
20		- ulong m_value = 0;
21		- int reg;
22		- unsigned char bi_enetaddr[6];
23		-
24		- /* get our mac */
25		- eth_getenv_enetaddr("ethaddr", bi_enetaddr);
26		-
27		- debug("BootpRequest => Our Mac: ");
28		- for (reg = 0; reg < 6; reg++)
29		- debug("%x%c", bi_enetaddr[reg], reg == 5 ? '\n' : ':');
30		-
31		- /* Mac-Manipulation 2 get seed1 */
32		- tst1 = 0;
33		- tst2 = 0;
34		- for (reg = 2; reg < 6; reg++) {
35		- tst1 = tst1 << 8;
36		- tst1 = tst1 \| bi_enetaddr[reg];
37		- }
38		- for (reg = 0; reg < 2; reg++) {
39		- tst2 = tst2 \| bi_enetaddr[reg];
40		- tst2 = tst2 << 8;
41		- }
42		-
43		- seed1 = tst1^tst2;
44		-
45		- /* Mirror seed1*/
46		- m_mask = 0x1;
47		- for (reg = 1; reg <= 32; reg++) {
48		- m_value \|= (m_mask & seed1);
49		- seed1 = seed1 >> 1;
50		- m_value = m_value << 1;
51		- }
52		- seed1 = m_value;
53		- seed2 = 0xb78d0945;
54		-}
55		-
56		-unsigned long rand(void)
57		-{
58		- ulong sum;
59		-
60		- /* Random Number Generator */
61		- sum = seed1 + seed2;
62		- if (sum < seed1 \|\| sum < seed2)
63		- sum++;
64		- seed2 = seed1;
65		- seed1 = sum;
66		-
67		- return sum;
68		-}
...	...	@@ -9,19 +9,36 @@
9	9	#ifndef __NET_RAND_H__
10	10	#define __NET_RAND_H__
11	11
12		-#define RAND_MAX 0xffffffff
	12	+#include <common.h>
13	13
14	14	/*
15		- * Seed the random number generator using the eth0 MAC address
	15	+ * Return a seed for the PRNG derived from the eth0 MAC address.
16	16	*/
17		-void srand_mac(void);
	17	+static inline unsigned int seed_mac(void)
	18	+{
	19	+ unsigned char enetaddr[6];
	20	+ unsigned int seed;
18	21
	22	+ /* get our mac */
	23	+ eth_getenv_enetaddr("ethaddr", enetaddr);
	24	+
	25	+ seed = enetaddr[5];
	26	+ seed ^= enetaddr[4] << 8;
	27	+ seed ^= enetaddr[3] << 16;
	28	+ seed ^= enetaddr[2] << 24;
	29	+ seed ^= enetaddr[1];
	30	+ seed ^= enetaddr[0] << 8;
	31	+
	32	+ return seed;
	33	+}
	34	+
19	35	/*
20		- * Get a random number (after seeding with MAC address)
21		- *
22		- * @return random number
	36	+ * Seed the random number generator using the eth0 MAC address.
23	37	*/
24		-unsigned long rand(void);
	38	+static inline void srand_mac(void)
	39	+{
	40	+ srand(seed_mac());
	41	+}
25	42
26	43	#endif /* __NET_RAND_H__ */