[U-Boot] [PATCH V2] net: bootp: Ignore packets whose yiaddr is 0

[U-Boot] [PATCH V2] net: bootp: Ignore packets whose yiaddr is 0

[Peng Fan]

From: Peng Fan <peng.fan@nxp.com>

When doing `dhcp`, there is a bad dhcp server in my network
which always reply dhcp request with yiaddr 0, which cause
uboot can not successfully get ipaddr from the good dhcp server.
But the Linux PC can get the ip address even if there is a bad
dhcp server. This patch is to fix that even if there is a bad
dhcp server, uboot can still get ipaddr and tftp work ok.

The way is to ignore the packets from the bad dhcp server by filtering
out the yiaddr whose value is 0.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Cc: Joe Hershberger <joe.hershberger@ni.com>
---

Changes V2:
 Take Wolfgang's suggestion, move the code after debug message.

 net/bootp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/bootp.c b/net/bootp.c
index 8aeddb0..8da2e9b 100644
--- a/net/bootp.c
+++ b/net/bootp.c
@@ -995,6 +995,9 @@ static void dhcp_handler(uchar *pkt, unsigned dest, struct in_addr sip,
 	debug("DHCPHandler: got DHCP packet: (src=%d, dst=%d, len=%d) state: "
 	      "%d\n", src, dest, len, dhcp_state);
 
+	if (net_read_ip(&bp->bp_yiaddr).s_addr == 0)
+		return;
+
 	switch (dhcp_state) {
 	case SELECTING:
 		/*
-- 
2.6.2

[U-Boot] [PATCH V2] net: bootp: Ignore packets whose yiaddr is 0

[Wolfgang Denk]

Dear Peng Fan,

In message <1452151703-30647-1-git-send-email-van.freenix@gmail.com> you wrote:
> From: Peng Fan <peng.fan@nxp.com>
> 
> When doing `dhcp`, there is a bad dhcp server in my network
> which always reply dhcp request with yiaddr 0, which cause
> uboot can not successfully get ipaddr from the good dhcp server.
> But the Linux PC can get the ip address even if there is a bad
> dhcp server. This patch is to fix that even if there is a bad
> dhcp server, uboot can still get ipaddr and tftp work ok.
> 
> The way is to ignore the packets from the bad dhcp server by filtering
> out the yiaddr whose value is 0.
> 
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> Cc: Joe Hershberger <joe.hershberger@ni.com>
> ---
> 
> Changes V2:
>  Take Wolfgang's suggestion, move the code after debug message.

THanks.

Reviewed-by: Wolfgang Denk <wd@denx.de>

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
About the use of language: it is impossible to sharpen a pencil  with
a  blunt  ax.  It is equally vain to try to do it with ten blunt axes
instead.                                           -- Edsger Dijkstra

[U-Boot] [PATCH V2] net: bootp: Ignore packets whose yiaddr is 0

[Peng Fan]

Gentle ping..

Regards,
Peng.

On Thu, Jan 07, 2016 at 05:09:04PM +0100, Wolfgang Denk wrote:
>Dear Peng Fan,
>
>In message <1452151703-30647-1-git-send-email-van.freenix@gmail.com> you wrote:
>> From: Peng Fan <peng.fan@nxp.com>
>> 
>> When doing `dhcp`, there is a bad dhcp server in my network
>> which always reply dhcp request with yiaddr 0, which cause
>> uboot can not successfully get ipaddr from the good dhcp server.
>> But the Linux PC can get the ip address even if there is a bad
>> dhcp server. This patch is to fix that even if there is a bad
>> dhcp server, uboot can still get ipaddr and tftp work ok.
>> 
>> The way is to ignore the packets from the bad dhcp server by filtering
>> out the yiaddr whose value is 0.
>> 
>> Signed-off-by: Peng Fan <peng.fan@nxp.com>
>> Cc: Joe Hershberger <joe.hershberger@ni.com>
>> ---
>> 
>> Changes V2:
>>  Take Wolfgang's suggestion, move the code after debug message.
>
>THanks.
>
>Reviewed-by: Wolfgang Denk <wd@denx.de>
>
>Best regards,
>
>Wolfgang Denk
>
>-- 
>DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
>HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
>Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
>About the use of language: it is impossible to sharpen a pencil  with
>a  blunt  ax.  It is equally vain to try to do it with ten blunt axes
>instead.                                           -- Edsger Dijkstra

[U-Boot] [PATCH V2] net: bootp: Ignore packets whose yiaddr is 0

[Joe Hershberger]

On Thu, Jan 7, 2016 at 1:28 AM, Peng Fan <van.freenix@gmail.com> wrote:
> From: Peng Fan <peng.fan@nxp.com>
>
> When doing `dhcp`, there is a bad dhcp server in my network
> which always reply dhcp request with yiaddr 0, which cause
> uboot can not successfully get ipaddr from the good dhcp server.
> But the Linux PC can get the ip address even if there is a bad
> dhcp server. This patch is to fix that even if there is a bad
> dhcp server, uboot can still get ipaddr and tftp work ok.
>
> The way is to ignore the packets from the bad dhcp server by filtering
> out the yiaddr whose value is 0.
>
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> Cc: Joe Hershberger <joe.hershberger@ni.com>

Acked-by: Joe Hershberger <joe.hershberger@ni.com>

[U-Boot] net: bootp: Ignore packets whose yiaddr is 0

[Joe Hershberger]

Hi Peng,

https://patchwork.ozlabs.org/patch/564188/ was applied to u-boot-net.git.

Thanks!
-Joe