On 05/02/2019 04:58, Callum Sinclair wrote:
> Currently the only way to clear the mfc cache was to delete the entries
> one by one using the MRT_DEL_MFC socket option or to destroy and
> recreate the socket.
>
> Create a new socket option which will clear the multicast forwarding
> cache on the socket without destroying the socket.
>
> Signed-off-by: Callum Sinclair <callum.sincl...@alliedtelesis.co.nz>
> ---
> include/uapi/linux/mroute.h | 3 ++-
> include/uapi/linux/mroute6.h | 3 ++-
> net/ipv4/ipmr.c | 40 +++++++++++++++++++++----------
> net/ipv6/ip6mr.c | 46 +++++++++++++++++++++++-------------
> 4 files changed, 61 insertions(+), 31 deletions(-)
>
Hi,
Why don't you do it per-table ? That is - use the selected table and flush
only its entries, I think that would be more useful. Also would be nice to
make the interface flush optional, e.g. depending on a user-supplied value.
Some people would like to flush only the MFC entries without deleting the
devices. Since it's called DEL_MFC_ALL, I'd expect this call to act only
on the MFC entries and not the device list, but it also flushes that.
I'd rename it to MRT_FLUSH with an argument which chooses to flush MFCs +
VIFs based on flags (so you could flush either one separately).
Thanks,
Nik
> diff --git a/include/uapi/linux/mroute.h b/include/uapi/linux/mroute.h
> index 5d37a9ccce63..8a0beb885cd9 100644
> --- a/include/uapi/linux/mroute.h
> +++ b/include/uapi/linux/mroute.h
> @@ -28,7 +28,8 @@
> #define MRT_TABLE (MRT_BASE+9) /* Specify mroute table ID
> */
> #define MRT_ADD_MFC_PROXY (MRT_BASE+10) /* Add a (*,*|G) mfc entry
> */
> #define MRT_DEL_MFC_PROXY (MRT_BASE+11) /* Del a (*,*|G) mfc entry
> */
> -#define MRT_MAX (MRT_BASE+11)
> +#define MRT_DEL_MFC_ALL (MRT_BASE+12) /* Del all multicast
> entries */
> +#define MRT_MAX (MRT_BASE+12)
>
> #define SIOCGETVIFCNT SIOCPROTOPRIVATE /* IP protocol privates
> */
> #define SIOCGETSGCNT (SIOCPROTOPRIVATE+1)
> diff --git a/include/uapi/linux/mroute6.h b/include/uapi/linux/mroute6.h
> index 9999cc006390..7def70cdf571 100644
> --- a/include/uapi/linux/mroute6.h
> +++ b/include/uapi/linux/mroute6.h
> @@ -31,7 +31,8 @@
> #define MRT6_TABLE (MRT6_BASE+9) /* Specify mroute table ID
> */
> #define MRT6_ADD_MFC_PROXY (MRT6_BASE+10) /* Add a (*,*|G) mfc entry
> */
> #define MRT6_DEL_MFC_PROXY (MRT6_BASE+11) /* Del a (*,*|G) mfc entry
> */
> -#define MRT6_MAX (MRT6_BASE+11)
> +#define MRT6_DEL_MFC_ALL (MRT6_BASE+12) /* Del all multicast entries
> */
> +#define MRT6_MAX (MRT6_BASE+12)
>
> #define SIOCGETMIFCNT_IN6 SIOCPROTOPRIVATE /* IP protocol privates
> */
> #define SIOCGETSGCNT_IN6 (SIOCPROTOPRIVATE+1)
> diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
> index ddbf8c9a1abb..ccfeebd38e1a 100644
> --- a/net/ipv4/ipmr.c
> +++ b/net/ipv4/ipmr.c
> @@ -1298,22 +1298,12 @@ static int ipmr_mfc_add(struct net *net, struct
> mr_table *mrt,
> return 0;
> }
>
> -/* Close the multicast socket, and clear the vif tables etc */
> -static void mroute_clean_tables(struct mr_table *mrt, bool all)
> +/* Clear the vif tables */
> +static void mroute_clean_cache(struct mr_table *mrt, bool all)
> {
> struct net *net = read_pnet(&mrt->net);
> - struct mr_mfc *c, *tmp;
> struct mfc_cache *cache;
> - LIST_HEAD(list);
> - int i;
> -
> - /* Shut down all active vif entries */
> - for (i = 0; i < mrt->maxvif; i++) {
> - if (!all && (mrt->vif_table[i].flags & VIFF_STATIC))
> - continue;
> - vif_delete(mrt, i, 0, &list);
> - }
> - unregister_netdevice_many(&list);
> + struct mr_mfc *c, *tmp;
>
> /* Wipe the cache */
> list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
> @@ -1340,6 +1330,23 @@ static void mroute_clean_tables(struct mr_table *mrt,
> bool all)
> }
> }
>
> +/* Close the multicast socket, and clear the vif tables etc */
> +static void mroute_clean_tables(struct mr_table *mrt, bool all)
> +{
> + LIST_HEAD(list);
> + int i;
> +
> + /* Shut down all active vif entries */
> + for (i = 0; i < mrt->maxvif; i++) {
> + if (!all && (mrt->vif_table[i].flags & VIFF_STATIC))
> + continue;
> + vif_delete(mrt, i, 0, &list);
> + }
> + unregister_netdevice_many(&list);
> +
> + mroute_clean_cache(mrt, all);
> +}
> +
> /* called from ip_ra_control(), before an RCU grace period,
> * we dont need to call synchronize_rcu() here
> */
> @@ -1482,6 +1489,13 @@ int ip_mroute_setsockopt(struct sock *sk, int optname,
> char __user *optval,
> sk ==
> rtnl_dereference(mrt->mroute_sk),
> parent);
> break;
> + case MRT_DEL_MFC_ALL:
> + rtnl_lock();
> + ipmr_for_each_table(mrt, net) {
> + mroute_clean_cache(mrt, true);
> + }
> + rtnl_unlock();
> + break;
> /* Control PIM assert. */
> case MRT_ASSERT:
> if (optlen != sizeof(val)) {
> diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
> index 30337b38274b..0168420d217b 100644
> --- a/net/ipv6/ip6mr.c
> +++ b/net/ipv6/ip6mr.c
> @@ -1492,25 +1492,11 @@ static int ip6mr_mfc_add(struct net *net, struct
> mr_table *mrt,
> return 0;
> }
>
> -/*
> - * Close the multicast socket, and clear the vif tables etc
> - */
> -
> -static void mroute_clean_tables(struct mr_table *mrt, bool all)
> +/* Clear the vif tables */
> +static void mroute_clean_cache(struct mr_table *mrt, bool all)
> {
> struct mr_mfc *c, *tmp;
> - LIST_HEAD(list);
> - int i;
> -
> - /* Shut down all active vif entries */
> - for (i = 0; i < mrt->maxvif; i++) {
> - if (!all && (mrt->vif_table[i].flags & VIFF_STATIC))
> - continue;
> - mif6_delete(mrt, i, 0, &list);
> - }
> - unregister_netdevice_many(&list);
>
> - /* Wipe the cache */
> list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
> if (!all && (c->mfc_flags & MFC_STATIC))
> continue;
> @@ -1536,6 +1522,27 @@ static void mroute_clean_tables(struct mr_table *mrt,
> bool all)
> }
> }
>
> +/*
> + * Close the multicast socket, and clear the vif tables etc
> + */
> +
> +static void mroute_clean_tables(struct mr_table *mrt, bool all)
> +{
> + LIST_HEAD(list);
> + int i;
> +
> + /* Shut down all active vif entries */
> + for (i = 0; i < mrt->maxvif; i++) {
> + if (!all && (mrt->vif_table[i].flags & VIFF_STATIC))
> + continue;
> + mif6_delete(mrt, i, 0, &list);
> + }
> + unregister_netdevice_many(&list);
> +
> + /* Wipe the cache */
> + mroute_clean_cache(mrt, all);
> +}
> +
> static int ip6mr_sk_init(struct mr_table *mrt, struct sock *sk)
> {
> int err = 0;
> @@ -1703,6 +1710,13 @@ int ip6_mroute_setsockopt(struct sock *sk, int
> optname, char __user *optval, uns
> parent);
> rtnl_unlock();
> return ret;
> + case MRT6_DEL_MFC_ALL:
> + rtnl_lock();
> + ip6mr_for_each_table(mrt, net) {
> + mroute_clean_cache(mrt, true);
> + }
> + rtnl_unlock();
> + return 0;
>
> /*
> * Control PIM assert (to activate pim will activate assert)
>
