From bdce340cc6a17efe1d980eda378c3b1984059362 Mon Sep 17 00:00:00 2001
From: Alexander Graf <agraf@suse.de>
Date: Fri, 15 Jun 2018 10:29:28 +0200
Subject: [PATCH] net: Add option to prefer bootp/dhcp serverip
Currently we can choose between 2 different types of behavior for the
serverip variable:
1) Always overwrite it with the DHCP server IP address (default)
2) Ignore what the DHCP server says (CONFIG_BOOTP_SERVERIP)
This patch adds a 3rd option:
3) Use serverip from DHCP if no serverip is given
(CONFIG_BOOTP_PREFER_SERVERIP)
With this new option, we can have the default case that a boot file gets
loaded from the DHCP provided TFTP server work while allowing users to
specify their own serverip variable to explicitly use a different tftp
server.
Signed-off-by: Alexander Graf <agraf@suse.de>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
---
cmd/Kconfig | 10 ++++++++++
net/bootp.c | 7 ++++++-
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/cmd/Kconfig b/cmd/Kconfig
index bbf9fc9113..aec209006d 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1121,6 +1121,16 @@ config BOOTP_HOSTNAME
help
The name may or may not be qualified with the local domain name.
+config BOOTP_PREFER_SERVERIP
+ bool "serverip variable takes precedent over DHCP server IP."
+ depends on CMD_BOOTP
+ help
+ By default a BOOTP/DHCP reply will overwrite the 'serverip' variable.
+
+ With this option enabled, the 'serverip' variable in the environment
+ takes precedence over DHCP server IP and will only be set by the DHCP
+ server if not already set in the environment.
+
config BOOTP_SUBNETMASK
bool "Request & store 'netmask' from BOOTP/DHCP server"
default y
diff --git a/net/bootp.c b/net/bootp.c
index fdcb4374a0..9a2b512e4a 100644
--- a/net/bootp.c
+++ b/net/bootp.c
@@ -147,9 +147,14 @@ static void store_net_params(struct bootp_hdr *bp)
{
#if !defined(CONFIG_BOOTP_SERVERIP)
struct in_addr tmp_ip;
+ bool overwrite_serverip = true;
+
+#if defined(CONFIG_BOOTP_PREFER_SERVERIP)
+ overwrite_serverip = false;
+#endif
net_copy_ip(&tmp_ip, &bp->bp_siaddr);
- if (tmp_ip.s_addr != 0)
+ if (tmp_ip.s_addr != 0 && (overwrite_serverip || !net_server_ip.s_addr))
net_copy_ip(&net_server_ip, &bp->bp_siaddr);
memcpy(net_server_ethaddr,
((struct ethernet_hdr *)net_rx_packet)->et_src, 6);