diff mbox series

[v3,1/2] ip/ip6_gre: Fix changing addr gen mode not generating IPv6 link local address

Message ID 20230124032105.79487-4-Thomas.Winter@alliedtelesis.co.nz (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series ip/ip6_gre: Fix GRE tunnels not generating IPv6 link local addresses | expand

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Context Check Description
netdev/tree_selection success Guessed tree name to be net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix warning Target tree name not specified in the subject
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 8 of 8 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 81 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Thomas Winter Jan. 24, 2023, 3:21 a.m. UTC
Commit e5dd729460ca 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.

Fixes: e5dd729460ca ("ip/ip6_gre: use the same logic as SIT interfaces when computing v6LL address")
Signed-off-by: Thomas Winter <Thomas.Winter@alliedtelesis.co.nz>
---
 net/ipv6/addrconf.c | 51 +++++++++++++++++++++++++--------------------
 1 file changed, 28 insertions(+), 23 deletions(-)

Comments

Jakub Kicinski Jan. 25, 2023, 3:24 a.m. UTC | #1
On Tue, 24 Jan 2023 16:21:04 +1300 Thomas Winter wrote:
> Commit e5dd729460ca 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.

The commit message reads like a description of the code changes, 
not the problem statement + extra context it should be.

Please start with a solid description of what the problem you're seeing
is, without referring to the implementation / code at all.

You should also mention why changing the code flow for LOOPBACK is safe
as it's not visible in the patch itself. And I think the subject should
be more broad than just GRE, since you also fix SIT.

Similar comments to a smaller extent for the second patch.

When you repost please make a fresh thread.
diff mbox series

Patch

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index f7a84a4acffc..0065b38fc85b 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3355,7 +3355,7 @@  static void addrconf_addr_gen(struct inet6_dev *idev, bool prefix_route)
 	}
 }
 
-static void addrconf_dev_config(struct net_device *dev)
+static void addrconf_eth_config(struct net_device *dev)
 {
 	struct inet6_dev *idev;
 
@@ -3447,6 +3447,30 @@  static void addrconf_gre_config(struct net_device *dev)
 }
 #endif
 
+static void addrconfig_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_eth_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;
-		}
+		addrconfig_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);
+				addrconfig_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);
+					addrconfig_init_auto_addrs(idev->dev);
 				}
 			}
 		}