From a085dc3dfc9ca56e638699176b04af3b19fefd3a Mon Sep 17 00:00:00 2001 From: Thomas Winter Date: Tue, 31 Jan 2023 16:46:45 +1300 Subject: [PATCH] ip/ip6_gre: Fix changing addr gen mode not generating IPv6 link local address [ Upstream commit 23ca0c2c93406bdb1150659e720bda1cec1fad04 ] For our point-to-point GRE tunnels, they have IN6_ADDR_GEN_MODE_NONE when they are created then we set IN6_ADDR_GEN_MODE_EUI64 when they come up to generate the IPv6 link local address for the interface. Recently we found that they were no longer generating IPv6 addresses. This issue would also have affected SIT tunnels. Commit afa5a712fd86 changed the code path so that GRE tunnels generate an IPv6 address based on the tunnel source address. It also changed the code path so GRE tunnels don't call addrconf_addr_gen in addrconf_dev_config which is called by addrconf_sysctl_addr_gen_mode when the IN6_ADDR_GEN_MODE is changed. This patch aims to fix this issue by moving the code in addrconf_notify which calls the addr gen for GRE and SIT into a separate function and calling it in the places that expect the IPv6 address to be generated. The previous addrconf_dev_config is renamed to addrconf_eth_config since it only expected eth type interfaces and follows the addrconf_gre/sit_config format. A part of this changes means that the loopback address will be attempted to be configured when changing addr_gen_mode for lo. This should not be a problem because the address should exist anyway and if does already exist then no error is produced. Fixes: afa5a712fd86 ("ip/ip6_gre: use the same logic as SIT interfaces when computing v6LL address") Signed-off-by: Thomas Winter Reviewed-by: David Ahern Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/ipv6/addrconf.c | 49 +++++++++++++++++++++++++-------------------- 1 file changed, 27 insertions(+), 22 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 9c3f5202a97ba..eaecaf2ffe002 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -3447,6 +3447,30 @@ static void addrconf_gre_config(struct net_device *dev) } #endif +static void addrconf_init_auto_addrs(struct net_device *dev) +{ + switch (dev->type) { +#if IS_ENABLED(CONFIG_IPV6_SIT) + case ARPHRD_SIT: + addrconf_sit_config(dev); + break; +#endif +#if IS_ENABLED(CONFIG_NET_IPGRE) || IS_ENABLED(CONFIG_IPV6_GRE) + case ARPHRD_IP6GRE: + case ARPHRD_IPGRE: + addrconf_gre_config(dev); + break; +#endif + case ARPHRD_LOOPBACK: + init_loopback(dev); + break; + + default: + addrconf_dev_config(dev); + break; + } +} + static int fixup_permanent_addr(struct net *net, struct inet6_dev *idev, struct inet6_ifaddr *ifp) @@ -3615,26 +3639,7 @@ static int addrconf_notify(struct notifier_block *this, unsigned long event, run_pending = 1; } - switch (dev->type) { -#if IS_ENABLED(CONFIG_IPV6_SIT) - case ARPHRD_SIT: - addrconf_sit_config(dev); - break; -#endif -#if IS_ENABLED(CONFIG_NET_IPGRE) || IS_ENABLED(CONFIG_IPV6_GRE) - case ARPHRD_IP6GRE: - case ARPHRD_IPGRE: - addrconf_gre_config(dev); - break; -#endif - case ARPHRD_LOOPBACK: - init_loopback(dev); - break; - - default: - addrconf_dev_config(dev); - break; - } + addrconf_init_auto_addrs(dev); if (!IS_ERR_OR_NULL(idev)) { if (run_pending) @@ -6397,7 +6402,7 @@ static int addrconf_sysctl_addr_gen_mode(struct ctl_table *ctl, int write, if (idev->cnf.addr_gen_mode != new_val) { idev->cnf.addr_gen_mode = new_val; - addrconf_dev_config(idev->dev); + addrconf_init_auto_addrs(idev->dev); } } else if (&net->ipv6.devconf_all->addr_gen_mode == ctl->data) { struct net_device *dev; @@ -6408,7 +6413,7 @@ static int addrconf_sysctl_addr_gen_mode(struct ctl_table *ctl, int write, if (idev && idev->cnf.addr_gen_mode != new_val) { idev->cnf.addr_gen_mode = new_val; - addrconf_dev_config(idev->dev); + addrconf_init_auto_addrs(idev->dev); } } } -- 2.39.5