On 26/05/2020 18:01, David Ahern wrote:
> From: David Ahern <dsah...@gmail.com>
>
> Similar to the last path, need to fix fib_info_nh_uses_dev for
> external nexthops to avoid referencing multiple nh_grp structs.
> Move the device check in fib_info_nh_uses_dev to a helper and
> create a nexthop version that is called if the fib_info uses an
> external nexthop.
>
> Fixes: 430a049190de ("nexthop: Add support for nexthop groups")
> Signed-off-by: David Ahern <dsah...@gmail.com>
> ---
> include/net/ip_fib.h | 10 ++++++++++
> include/net/nexthop.h | 25 +++++++++++++++++++++++++
> net/ipv4/fib_frontend.c | 19 ++++++++++---------
> 3 files changed, 45 insertions(+), 9 deletions(-)
>
Acked-by: Nikolay Aleksandrov <niko...@cumulusnetworks.com>
> diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
> index 1f1dd22980e4..6683558db7c9 100644
> --- a/include/net/ip_fib.h
> +++ b/include/net/ip_fib.h
> @@ -448,6 +448,16 @@ static inline int fib_num_tclassid_users(struct net *net)
> #endif
> int fib_unmerge(struct net *net);
>
> +static inline bool nhc_l3mdev_matches_dev(const struct fib_nh_common *nhc,
> +const struct net_device *dev)
> +{
> + if (nhc->nhc_dev == dev ||
> + l3mdev_master_ifindex_rcu(nhc->nhc_dev) == dev->ifindex)
> + return true;
> +
> + return false;
> +}
> +
> /* Exported by fib_semantics.c */
> int ip_fib_check_default(__be32 gw, struct net_device *dev);
> int fib_sync_down_dev(struct net_device *dev, unsigned long event, bool
> force);
> diff --git a/include/net/nexthop.h b/include/net/nexthop.h
> index 9414ae46fc1c..35680a8c2a1c 100644
> --- a/include/net/nexthop.h
> +++ b/include/net/nexthop.h
> @@ -266,6 +266,31 @@ struct fib_nh_common *nexthop_get_nhc_lookup(const
> struct nexthop *nh,
> return NULL;
> }
>
> +static inline bool nexthop_uses_dev(const struct nexthop *nh,
> + const struct net_device *dev)
> +{
> + struct nh_info *nhi;
> +
> + if (nh->is_group) {
> + struct nh_group *nhg = rcu_dereference(nh->nh_grp);
> + int i;
> +
> + for (i = 0; i < nhg->num_nh; i++) {
> + struct nexthop *nhe = nhg->nh_entries[i].nh;
> +
> + nhi = rcu_dereference(nhe->nh_info);
> + if (nhc_l3mdev_matches_dev(&nhi->fib_nhc, dev))
> + return true;
> + }
> + } else {
> + nhi = rcu_dereference(nh->nh_info);
> + if (nhc_l3mdev_matches_dev(&nhi->fib_nhc, dev))
> + return true;
> + }
> +
> + return false;
> +}
> +
> static inline unsigned int fib_info_num_path(const struct fib_info *fi)
> {
> if (unlikely(fi->nh))
> diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
> index 213be9c050ad..aebb50735c68 100644
> --- a/net/ipv4/fib_frontend.c
> +++ b/net/ipv4/fib_frontend.c
> @@ -309,17 +309,18 @@ bool fib_info_nh_uses_dev(struct fib_info *fi, const
> struct net_device *dev)
> {
> bool dev_match = false;
> #ifdef CONFIG_IP_ROUTE_MULTIPATH
> - int ret;
> + if (unlikely(fi->nh)) {
> + dev_match = nexthop_uses_dev(fi->nh, dev);
> + } else {
> + int ret;
>
> - for (ret = 0; ret < fib_info_num_path(fi); ret++) {
> - const struct fib_nh_common *nhc = fib_info_nhc(fi, ret);
> + for (ret = 0; ret < fib_info_num_path(fi); ret++) {
> + const struct fib_nh_common *nhc = fib_info_nhc(fi, ret);
>
> - if (nhc->nhc_dev == dev) {
> - dev_match = true;
> - break;
> - } else if (l3mdev_master_ifindex_rcu(nhc->nhc_dev) ==
> dev->ifindex) {
> - dev_match = true;
> - break;
> + if (nhc_l3mdev_matches_dev(nhc, dev)) {
> + dev_match = true;
> + break;
> + }
> }
> }
> #else
>
