[U-Boot] [PATCH v2 03/21] net: Move MAC-seeded rand out of bootp.c
Simon Glass
sjg at chromium.org
Sat Apr 21 04:54:44 CEST 2012
Hi Joe,
On Tue, Mar 27, 2012 at 4:42 PM, Joe Hershberger <joe.hershberger at ni.com> wrote:
> 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 at ni.com>
> Cc: Joe Hershberger <joe.hershberger at gmail.com>
> Cc: Simon Glass <sjg at chromium.org>
> Cc: Mike Frysinger <vapier at gentoo.org>
> ---
> net/Makefile | 1 +
> net/bootp.c | 69 +++++++++++--------------------------------------------
> net/bootp.h | 3 --
> net/net_rand.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> net/net_rand.h | 17 +++++++++++++
> 5 files changed, 100 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..5949e77 100644
> --- a/net/bootp.c
> +++ b/net/bootp.c
> @@ -12,6 +12,9 @@
> #include <command.h>
> #include <net.h>
> #include "bootp.h"
> +#ifdef CONFIG_BOOTP_RANDOM_DELAY
> +#include "net_rand.h"
> +#endif
How about just always including it?
> #include "tftp.h"
> #include "nfs.h"
> #ifdef CONFIG_STATUS_LED
> @@ -37,9 +40,6 @@
>
> 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 +584,9 @@ 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 +594,16 @@ 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;
> - }
> -
> - seed1 = tst1^tst2;
> + if (BootpTry == 0)
> + srand_mac();
>
> - /* 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);
Spaces around operators
> + 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..744e2f9
> --- /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 at denx.de
> + */
> +
> +#include <common.h>
> +#include <net.h>
> +#include "net_rand.h"
> +
> +static ulong seed1, seed2;
> +
> +void srand_mac(void)
Perhaps pass in the place to put the random mac, rather than using a global?
> +{
> + 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..8569f93
> --- /dev/null
> +++ b/net/net_rand.h
> @@ -0,0 +1,17 @@
> +/*
> + * 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
Do we want lower case hex? Not sure.
> +
> +void srand_mac(void);
> +unsigned long rand(void);
Function comments are nice :-)
> +
> +#endif /* __NET_RAND_H__ */
> --
> 1.6.0.2
>
Regards,
Simon
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