| Message ID | 20180614100426.40511-3-agraf@suse.de |
|---|---|
| State | Changes Requested |
| Delegated to: | Joe Hershberger |
| Headers | show |
| Series | net: Sanitize DHCP variable override | expand |
On Thu, Jun 14, 2018 at 5:04 AM, Alexander Graf <agraf@suse.de> wrote: > 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>
diff --git a/cmd/Kconfig b/cmd/Kconfig index e283cb9a8a..80a5af8a0c 100644 --- a/cmd/Kconfig +++ b/cmd/Kconfig @@ -1121,6 +1121,17 @@ 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. + default n + 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 f3da8572b7..154c71d694 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);
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> --- v1 -> v2: - remove README entry - improve Kconfig help texts --- cmd/Kconfig | 11 +++++++++++ net/bootp.c | 7 ++++++- 2 files changed, 17 insertions(+), 1 deletion(-)