Make the MAC-seeded random number generator available to /net in general. MAC-seeded rand will be needed by link-local as well, so give it an interface.
Signed-off-by: Joe Hershberger joe.hershberger@ni.com Cc: Joe Hershberger joe.hershberger@gmail.com --- Changes for v3: - Lowercase hex - Add blank line - Always include header, even when it isn't needed - Add function comments
net/Makefile | 1 + net/bootp.c | 67 ++++++++++--------------------------------------------- net/bootp.h | 3 -- net/net_rand.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ net/net_rand.h | 26 +++++++++++++++++++++ 5 files changed, 107 insertions(+), 58 deletions(-) create mode 100644 net/net_rand.c create mode 100644 net/net_rand.h
diff --git a/net/Makefile b/net/Makefile index 0544f6b..5901046 100644 --- a/net/Makefile +++ b/net/Makefile @@ -31,6 +31,7 @@ COBJS-$(CONFIG_CMD_NET) += bootp.o COBJS-$(CONFIG_CMD_DNS) += dns.o COBJS-$(CONFIG_CMD_NET) += eth.o COBJS-$(CONFIG_CMD_NET) += net.o +COBJS-$(CONFIG_BOOTP_RANDOM_DELAY) += net_rand.o COBJS-$(CONFIG_CMD_NFS) += nfs.o COBJS-$(CONFIG_CMD_RARP) += rarp.o COBJS-$(CONFIG_CMD_SNTP) += sntp.o diff --git a/net/bootp.c b/net/bootp.c index d0a7da2..0185e56 100644 --- a/net/bootp.c +++ b/net/bootp.c @@ -12,6 +12,7 @@ #include <command.h> #include <net.h> #include "bootp.h" +#include "net_rand.h" #include "tftp.h" #include "nfs.h" #ifdef CONFIG_STATUS_LED @@ -37,9 +38,6 @@
ulong BootpID; int BootpTry; -#ifdef CONFIG_BOOTP_RANDOM_DELAY -ulong seed1, seed2; -#endif
#if defined(CONFIG_CMD_DHCP) dhcp_state_t dhcp_state = INIT; @@ -584,6 +582,9 @@ BootpRequest(void) uchar *pkt, *iphdr; struct Bootp_t *bp; int ext_len, pktlen, iplen; +#ifdef CONFIG_BOOTP_RANDOM_DELAY + ulong i, rand_ms; +#endif
bootstage_mark_name(BOOTSTAGE_ID_BOOTP_START, "bootp_start"); #if defined(CONFIG_CMD_DHCP) @@ -591,60 +592,16 @@ BootpRequest(void) #endif
#ifdef CONFIG_BOOTP_RANDOM_DELAY /* Random BOOTP delay */ - unsigned char bi_enetaddr[6]; - int reg; - ulong tst1, tst2, sum, m_mask, m_value = 0; - - if (BootpTry == 0) { - /* 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; - } + if (BootpTry == 0) + srand_mac();
- 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; - } - - /* Random Number Generator */ - for (reg = 0; reg <= 0; reg++) { - sum = seed1 + seed2; - if (sum < seed1 || sum < seed2) - sum++; - seed2 = seed1; - seed1 = sum; - - if (BootpTry <= 2) { /* Start with max 1024 * 1ms */ - sum = sum >> (22-BootpTry); - } else { /*After 3rd BOOTP request max 8192 * 1ms */ - sum = sum >> 19; - } - } + if (BootpTry <= 2) /* Start with max 1024 * 1ms */ + rand_ms = rand() >> (22 - BootpTry); + else /* After 3rd BOOTP request max 8192 * 1ms */ + rand_ms = rand() >> 19;
- printf("Random delay: %ld ms...\n", sum); - for (reg = 0; reg < sum; reg++) + printf("Random delay: %ld ms...\n", rand_ms); + for (i = 0; i < rand_ms; i++) udelay(1000); /*Wait 1ms*/
#endif /* CONFIG_BOOTP_RANDOM_DELAY */ diff --git a/net/bootp.h b/net/bootp.h index ce73734..bf4e875 100644 --- a/net/bootp.h +++ b/net/bootp.h @@ -63,9 +63,6 @@ struct Bootp_t { extern ulong BootpID; /* ID of cur BOOTP request */ extern char BootFile[128]; /* Boot file name */ extern int BootpTry; -#ifdef CONFIG_BOOTP_RANDOM_DELAY -extern ulong seed1, seed2; /* seed for random BOOTP delay */ -#endif
/* Send a BOOTP request */ diff --git a/net/net_rand.c b/net/net_rand.c new file mode 100644 index 0000000..5387aba --- /dev/null +++ b/net/net_rand.c @@ -0,0 +1,68 @@ +/* + * 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; +} diff --git a/net/net_rand.h b/net/net_rand.h new file mode 100644 index 0000000..c98db64 --- /dev/null +++ b/net/net_rand.h @@ -0,0 +1,26 @@ +/* + * Copied from LiMon - BOOTP. + * + * Copyright 1994, 1995, 2000 Neil Russell. + * (See License) + * Copyright 2000 Paolo Scaffardi + */ + +#ifndef __NET_RAND_H__ +#define __NET_RAND_H__ + +#define RAND_MAX 0xffffffff + +/* + * Seed the random number generator using the eth0 MAC address + */ +void srand_mac(void); + +/* + * Get a random number (after seeding with MAC address) + * + * @return random number + */ +unsigned long rand(void); + +#endif /* __NET_RAND_H__ */