From eefef1cf7653cd4e0aaf743c00ae8345086cdc01 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Sun, 1 Feb 2009 01:04:33 -0800 Subject: [PATCH] net: add ARP notify option for devices This adds another inet device option to enable gratuitous ARP when device is brought up or address change. This is handy for clusters or virtualization. Signed-off-by: Stephen Hemminger Signed-off-by: Jeremy Fitzhardinge Signed-off-by: David S. Miller --- Documentation/networking/ip-sysctl.txt | 6 ++++++ include/linux/inetdevice.h | 1 + include/linux/sysctl.h | 1 + kernel/sysctl_check.c | 1 + net/ipv4/devinet.c | 9 +++++++++ 5 files changed, 18 insertions(+) diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index c7712787933..ff3f219ee4d 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -782,6 +782,12 @@ arp_ignore - INTEGER The max value from conf/{all,interface}/arp_ignore is used when ARP request is received on the {interface} +arp_notify - BOOLEAN + Define mode for notification of address and device changes. + 0 - (default): do nothing + 1 - Generate gratuitous arp replies when device is brought up + or hardware address changes. + arp_accept - BOOLEAN Define behavior when gratuitous arp replies are received: 0 - drop gratuitous arp frames diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h index 06fcdb45106..acef2a770b6 100644 --- a/include/linux/inetdevice.h +++ b/include/linux/inetdevice.h @@ -108,6 +108,7 @@ static inline void ipv4_devconf_setall(struct in_device *in_dev) #define IN_DEV_ARPFILTER(in_dev) IN_DEV_ORCONF((in_dev), ARPFILTER) #define IN_DEV_ARP_ANNOUNCE(in_dev) IN_DEV_MAXCONF((in_dev), ARP_ANNOUNCE) #define IN_DEV_ARP_IGNORE(in_dev) IN_DEV_MAXCONF((in_dev), ARP_IGNORE) +#define IN_DEV_ARP_NOTIFY(in_dev) IN_DEV_MAXCONF((in_dev), ARP_NOTIFY) struct in_ifaddr { diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h index 39d471d1163..e76d3b22a46 100644 --- a/include/linux/sysctl.h +++ b/include/linux/sysctl.h @@ -490,6 +490,7 @@ enum NET_IPV4_CONF_ARP_IGNORE=19, NET_IPV4_CONF_PROMOTE_SECONDARIES=20, NET_IPV4_CONF_ARP_ACCEPT=21, + NET_IPV4_CONF_ARP_NOTIFY=22, __NET_IPV4_CONF_MAX }; diff --git a/kernel/sysctl_check.c b/kernel/sysctl_check.c index fafeb48f27c..b38423ca711 100644 --- a/kernel/sysctl_check.c +++ b/kernel/sysctl_check.c @@ -219,6 +219,7 @@ static const struct trans_ctl_table trans_net_ipv4_conf_vars_table[] = { { NET_IPV4_CONF_ARP_IGNORE, "arp_ignore" }, { NET_IPV4_CONF_PROMOTE_SECONDARIES, "promote_secondaries" }, { NET_IPV4_CONF_ARP_ACCEPT, "arp_accept" }, + { NET_IPV4_CONF_ARP_NOTIFY, "arp_notify" }, {} }; diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index 309997edc8a..d519a6a6672 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -1075,6 +1075,14 @@ static int inetdev_event(struct notifier_block *this, unsigned long event, } } ip_mc_up(in_dev); + /* fall through */ + case NETDEV_CHANGEADDR: + if (IN_DEV_ARP_NOTIFY(in_dev)) + arp_send(ARPOP_REQUEST, ETH_P_ARP, + in_dev->ifa_list->ifa_address, + dev, + in_dev->ifa_list->ifa_address, + NULL, dev->dev_addr, NULL); break; case NETDEV_DOWN: ip_mc_down(in_dev); @@ -1439,6 +1447,7 @@ static struct devinet_sysctl_table { DEVINET_SYSCTL_RW_ENTRY(ARP_ANNOUNCE, "arp_announce"), DEVINET_SYSCTL_RW_ENTRY(ARP_IGNORE, "arp_ignore"), DEVINET_SYSCTL_RW_ENTRY(ARP_ACCEPT, "arp_accept"), + DEVINET_SYSCTL_RW_ENTRY(ARP_NOTIFY, "arp_notify"), DEVINET_SYSCTL_FLUSHING_ENTRY(NOXFRM, "disable_xfrm"), DEVINET_SYSCTL_FLUSHING_ENTRY(NOPOLICY, "disable_policy"),