Commit d3623dd5 authored by Guillaume Nault's avatar Guillaume Nault Committed by Paolo Abeni
Browse files

ipv6: Simplify link-local address generation for IPv6 GRE. 



Since commit 3e6a0243 ("gre: Fix again IPv6 link-local address
generation."), addrconf_gre_config() has stopped handling IP6GRE
devices specially and just calls the regular addrconf_addr_gen()
function to create their link-local IPv6 addresses.

We can thus avoid using addrconf_gre_config() for IP6GRE devices and
use the normal IPv6 initialisation path instead (that is, jump directly
to addrconf_dev_config() in addrconf_init_auto_addrs()).

See commit 3e6a0243 ("gre: Fix again IPv6 link-local address
generation.") for a deeper explanation on how and why GRE devices
started handling their IPv6 link-local address generation specially,
why it was a problem, and why this is not even necessary in most cases
(especially for GRE over IPv6).

Signed-off-by: default avatarGuillaume Nault <gnault@redhat.com>
Reviewed-by: default avatarIdo Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/a9144be9c7ec3cf09f25becae5e8fdf141fde9f6.1750075076.git.gnault@redhat.com


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent f6be1f29

net/ipv6/addrconf.c

+5 −5
Original line number Diff line number Diff line
@@ -3208,7 +3208,7 @@ static void add_addr(struct inet6_dev *idev, const struct in6_addr *addr, 
	}

}



#if IS_ENABLED(CONFIG_IPV6_SIT) || IS_ENABLED(CONFIG_NET_IPGRE) || IS_ENABLED(CONFIG_IPV6_GRE)

#if IS_ENABLED(CONFIG_IPV6_SIT) || IS_ENABLED(CONFIG_NET_IPGRE)

static void add_v4_addrs(struct inet6_dev *idev)

{

	struct in6_addr addr;
@@ -3463,6 +3463,7 @@ static void addrconf_dev_config(struct net_device *dev) 
	    (dev->type != ARPHRD_IEEE1394) &&

	    (dev->type != ARPHRD_TUNNEL6) &&

	    (dev->type != ARPHRD_6LOWPAN) &&

	    (dev->type != ARPHRD_IP6GRE) &&

	    (dev->type != ARPHRD_TUNNEL) &&

	    (dev->type != ARPHRD_NONE) &&

	    (dev->type != ARPHRD_RAWIP)) {
@@ -3518,7 +3519,7 @@ static void addrconf_sit_config(struct net_device *dev) 
}

#endif



#if IS_ENABLED(CONFIG_NET_IPGRE) || IS_ENABLED(CONFIG_IPV6_GRE)

#if IS_ENABLED(CONFIG_NET_IPGRE)

static void addrconf_gre_config(struct net_device *dev)

{

	struct inet6_dev *idev;
@@ -3536,7 +3537,7 @@ static void addrconf_gre_config(struct net_device *dev) 
	 * which is in EUI64 mode (as __ipv6_isatap_ifid() would fail in this

	 * case). Such devices fall back to add_v4_addrs() instead.

	 */

	if (!(dev->type == ARPHRD_IPGRE && *(__be32 *)dev->dev_addr == 0 &&

	if (!(*(__be32 *)dev->dev_addr == 0 &&

	      idev->cnf.addr_gen_mode == IN6_ADDR_GEN_MODE_EUI64)) {

		addrconf_addr_gen(idev, true);

		return;
@@ -3557,8 +3558,7 @@ static void addrconf_init_auto_addrs(struct net_device *dev) 
		addrconf_sit_config(dev);

		break;

#endif

#if IS_ENABLED(CONFIG_NET_IPGRE) || IS_ENABLED(CONFIG_IPV6_GRE)

	case ARPHRD_IP6GRE:

#if IS_ENABLED(CONFIG_NET_IPGRE)

	case ARPHRD_IPGRE:

		addrconf_gre_config(dev);

		break;