[PATCH] ipmr: ip6mr: Create new sockopt to clear mfc cache only

[PATCH] ipmr: ip6mr: Create new sockopt to clear mfc cache only

[Callum Sinclair]

Created a way to clear the multicast forwarding cache on a socket
without having to either remove the entries manually using the delete
entry socket option or destroy and recreate the multicast socket.

Patch Set 2:
  - Fix Compile Errors

Patch Set 3:
  - Fix Style Errors

Callum Sinclair (1):
  ipmr: ip6mr: Create new sockopt to clear mfc cache only

 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(-)

-- 
2.20.1

[PATCH] ipmr: ip6mr: Create new sockopt to clear mfc cache only

[Callum Sinclair]

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.sinclair@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(-)

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)
-- 
2.20.1

Re: [PATCH] ipmr: ip6mr: Create new sockopt to clear mfc cache only

[Nikolay Aleksandrov]

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.sinclair@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)
> 

Re: [PATCH] ipmr: ip6mr: Create new sockopt to clear mfc cache only

[Nikolay Aleksandrov]

On 07/02/2019 04:08, 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.sinclair@alliedtelesis.co.nz>
> ---
>  include/uapi/linux/mroute.h  |  7 +++-
>  include/uapi/linux/mroute6.h |  7 +++-
>  net/ipv4/ipmr.c              | 69 +++++++++++++++++++++-------------
>  net/ipv6/ip6mr.c             | 73 ++++++++++++++++++++++--------------
>  4 files changed, 99 insertions(+), 57 deletions(-)
> 

Hi,
Thanks for working on this. I think you missed one comment, this still seems
to clean all tables even though the socket has a table assigned. Could it
act only on that table ? All of the MRT calls besides the init act only on
the initialized table. 
Also you're not checking if optlen is proper size, and I wonder which kernel is this
based on ? Because in net-next ip_mroute_setsockopt() takes rtnl in the beginning
and releases it in the end with the exception of MRT_DONE which needs to release it
earlier, the code below would cause a deadlock trying to get rtnl again in MRT_FLUSH.
This patch should be targeted at net-next, please indicate that also in your subject:
e.g. [PATCH net-next].

Thanks,
 Nik

> diff --git a/include/uapi/linux/mroute.h b/include/uapi/linux/mroute.h
> index 5d37a9ccce63..2d475edc3ec3 100644
> --- a/include/uapi/linux/mroute.h
> +++ b/include/uapi/linux/mroute.h
> @@ -28,12 +28,17 @@
>  #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_FLUSH	(MRT_BASE+12)	/* Flush all multicast entries and vifs	*/
> +#define MRT_MAX		(MRT_BASE+12)
>  
>  #define SIOCGETVIFCNT	SIOCPROTOPRIVATE	/* IP protocol privates */
>  #define SIOCGETSGCNT	(SIOCPROTOPRIVATE+1)
>  #define SIOCGETRPF	(SIOCPROTOPRIVATE+2)
>  
> +/* Flags used for MRT_FLUSH */
> +#define MRT_FLUSH_ENTRIES	1	/* For flushing all multicast entries */
> +#define MRT_FLUSH_VIFS		2	/* For flushing all multicast vifs */
> +
>  #define MAXVIFS		32
>  typedef unsigned long vifbitmap_t;	/* User mode code depends on this lot */
>  typedef unsigned short vifi_t;
> diff --git a/include/uapi/linux/mroute6.h b/include/uapi/linux/mroute6.h
> index 9999cc006390..b04094d997c8 100644
> --- a/include/uapi/linux/mroute6.h
> +++ b/include/uapi/linux/mroute6.h
> @@ -31,12 +31,17 @@
>  #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_FLUSH	(MRT6_BASE+12)	/* Flush all multicast entries and vifs	*/
> +#define MRT6_MAX	(MRT6_BASE+12)
>  
>  #define SIOCGETMIFCNT_IN6	SIOCPROTOPRIVATE	/* IP protocol privates */
>  #define SIOCGETSGCNT_IN6	(SIOCPROTOPRIVATE+1)
>  #define SIOCGETRPF	(SIOCPROTOPRIVATE+2)
>  
> +/* Flags used for MRT6_FLUSH*/
> +#define MRT6_FLUSH_ENTRIES	1	/* For flushing all multicast entries */
> +#define MRT6_FLUSH_VIFS		2	/* For flushing all multicast vifs */
> +
>  #define MAXMIFS		32
>  typedef unsigned long mifbitmap_t;	/* User mode code depends on this lot */
>  typedef unsigned short mifi_t;
> diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
> index ddbf8c9a1abb..2eb569138569 100644
> --- a/net/ipv4/ipmr.c
> +++ b/net/ipv4/ipmr.c
> @@ -416,7 +416,7 @@ static struct mr_table *ipmr_new_table(struct net *net, u32 id)
>  static void ipmr_free_table(struct mr_table *mrt)
>  {
>  	del_timer_sync(&mrt->ipmr_expire_timer);
> -	mroute_clean_tables(mrt, true);
> +	mroute_clean_tables(mrt, true, MRT_FLUSH_VIFS | MRT_FLUSH_ENTRIES);
>  	rhltable_destroy(&mrt->mfc_hash);
>  	kfree(mrt);
>  }
> @@ -1299,44 +1299,48 @@ static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
>  }
>  
>  /* Close the multicast socket, and clear the vif tables etc */
> -static void mroute_clean_tables(struct mr_table *mrt, bool all)
> +static void mroute_clean_tables(struct mr_table *mrt, bool all, int flags)
>  {
>  	struct net *net = read_pnet(&mrt->net);
> -	struct mr_mfc *c, *tmp;
>  	struct mfc_cache *cache;
> +	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;
> -		vif_delete(mrt, i, 0, &list);
> +	if (flags & MRT_FLUSH_VIFS) {
> +		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);
>  	}
> -	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;
> -		rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
> -		list_del_rcu(&c->list);
> -		cache = (struct mfc_cache *)c;
> -		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
> -					      mrt->id);
> -		mroute_netlink_event(mrt, cache, RTM_DELROUTE);
> -		mr_cache_put(c);
> -	}
> -
> -	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
> -		spin_lock_bh(&mfc_unres_lock);
> -		list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
> -			list_del(&c->list);
> +	if (flags & MRT_FLUSH_ENTRIES) {
> +		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
> +			if (!all && (c->mfc_flags & MFC_STATIC))
> +				continue;
> +			rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
> +			list_del_rcu(&c->list);
>  			cache = (struct mfc_cache *)c;
> +			call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
> +										  mrt->id);
>  			mroute_netlink_event(mrt, cache, RTM_DELROUTE);
> -			ipmr_destroy_unres(mrt, cache);
> +			mr_cache_put(c);
> +		}
> +
> +		if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
> +			spin_lock_bh(&mfc_unres_lock);
> +			list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
> +				list_del(&c->list);
> +				cache = (struct mfc_cache *)c;
> +				mroute_netlink_event(mrt, cache, RTM_DELROUTE);
> +				ipmr_destroy_unres(mrt, cache);
> +			}
> +			spin_unlock_bh(&mfc_unres_lock);
>  		}
> -		spin_unlock_bh(&mfc_unres_lock);
>  	}
>  }
>  
> @@ -1357,7 +1361,7 @@ static void mrtsock_destruct(struct sock *sk)
>  						    NETCONFA_IFINDEX_ALL,
>  						    net->ipv4.devconf_all);
>  			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
> -			mroute_clean_tables(mrt, false);
> +			mroute_clean_tables(mrt, false, MRT_FLUSH_VIFS | MRT_FLUSH_ENTRIES);
>  		}
>  	}
>  	rtnl_unlock();
> @@ -1482,6 +1486,17 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
>  					   sk == rtnl_dereference(mrt->mroute_sk),
>  					   parent);
>  		break;
> +	case MRT_FLUSH:
> +		if (get_user(val, (int __user *)optval)) {
> +			ret = -EFAULT;
> +			break;
> +		}
> +		rtnl_lock();
> +		ipmr_for_each_table(mrt, net) {
> +			mroute_clean_tables(mrt, true, val);
> +		}
> +		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..473c83d197fe 100644
> --- a/net/ipv6/ip6mr.c
> +++ b/net/ipv6/ip6mr.c
> @@ -393,7 +393,7 @@ static struct mr_table *ip6mr_new_table(struct net *net, u32 id)
>  static void ip6mr_free_table(struct mr_table *mrt)
>  {
>  	del_timer_sync(&mrt->ipmr_expire_timer);
> -	mroute_clean_tables(mrt, true);
> +	mroute_clean_tables(mrt, true, MRT6_FLUSH_VIFS | MRT6_FLUSH_ENTRIES);
>  	rhltable_destroy(&mrt->mfc_hash);
>  	kfree(mrt);
>  }
> @@ -1496,43 +1496,47 @@ static int ip6mr_mfc_add(struct net *net, struct mr_table *mrt,
>   *	Close the multicast socket, and clear the vif tables etc
>   */
>  
> -static void mroute_clean_tables(struct mr_table *mrt, bool all)
> +static void mroute_clean_tables(struct mr_table *mrt, bool all, int flags)
>  {
>  	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);
> +	if (flags & MRT6_FLUSH_VIFS) {
> +		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);
>  	}
> -	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;
> -		rhltable_remove(&mrt->mfc_hash, &c->mnode, ip6mr_rht_params);
> -		list_del_rcu(&c->list);
> -		mr6_netlink_event(mrt, (struct mfc6_cache *)c, RTM_DELROUTE);
> -		mr_cache_put(c);
> -	}
> +	if (flags & MRT6_FLUSH_ENTRIES) {
> +		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
> +			if (!all && (c->mfc_flags & MFC_STATIC))
> +				continue;
> +			rhltable_remove(&mrt->mfc_hash, &c->mnode, ip6mr_rht_params);
> +			list_del_rcu(&c->list);
> +			mr6_netlink_event(mrt, (struct mfc6_cache *)c, RTM_DELROUTE);
> +			mr_cache_put(c);
> +		}
>  
> -	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
> -		spin_lock_bh(&mfc_unres_lock);
> -		list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
> -			list_del(&c->list);
> -			call_ip6mr_mfc_entry_notifiers(read_pnet(&mrt->net),
> -						       FIB_EVENT_ENTRY_DEL,
> -						       (struct mfc6_cache *)c,
> -						       mrt->id);
> -			mr6_netlink_event(mrt, (struct mfc6_cache *)c,
> -					  RTM_DELROUTE);
> -			ip6mr_destroy_unres(mrt, (struct mfc6_cache *)c);
> +		if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
> +			spin_lock_bh(&mfc_unres_lock);
> +			list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
> +				list_del(&c->list);
> +				call_ip6mr_mfc_entry_notifiers(read_pnet(&mrt->net),
> +											   FIB_EVENT_ENTRY_DEL,
> +											   (struct mfc6_cache *)c,
> +											   mrt->id);
> +				mr6_netlink_event(mrt, (struct mfc6_cache *)c,
> +						  RTM_DELROUTE);
> +				ip6mr_destroy_unres(mrt, (struct mfc6_cache *)c);
> +			}
> +			spin_unlock_bh(&mfc_unres_lock);
>  		}
> -		spin_unlock_bh(&mfc_unres_lock);
>  	}
>  }
>  
> @@ -1588,7 +1592,7 @@ int ip6mr_sk_done(struct sock *sk)
>  						     NETCONFA_IFINDEX_ALL,
>  						     net->ipv6.devconf_all);
>  
> -			mroute_clean_tables(mrt, false);
> +			mroute_clean_tables(mrt, false, MRT6_FLUSH_VIFS | MRT6_FLUSH_ENTRIES);
>  			err = 0;
>  			break;
>  		}
> @@ -1703,6 +1707,19 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, uns
>  					    parent);
>  		rtnl_unlock();
>  		return ret;
> +	case MRT6_DEL_MFC_ALL:
> +	{
> +		int flags;
> +
> +		if (get_user(flags, (int __user *)optval))
> +			return -EFAULT;
> +		rtnl_lock();
> +		ip6mr_for_each_table(mrt, net) {
> +			mroute_clean_tables(mrt, true, flags);
> +		}
> +		rtnl_unlock();
> +		return 0;
> +	}
>  
>  	/*
>  	 *	Control PIM assert (to activate pim will activate assert)
> 

[PATCH] ipmr: ip6mr: Create new sockopt to clear mfc cache only

[Callum Sinclair]

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.sinclair@alliedtelesis.co.nz>
---
 include/uapi/linux/mroute.h  |  7 +++-
 include/uapi/linux/mroute6.h |  7 +++-
 net/ipv4/ipmr.c              | 69 +++++++++++++++++++++-------------
 net/ipv6/ip6mr.c             | 73 ++++++++++++++++++++++--------------
 4 files changed, 99 insertions(+), 57 deletions(-)

diff --git a/include/uapi/linux/mroute.h b/include/uapi/linux/mroute.h
index 5d37a9ccce63..2d475edc3ec3 100644
--- a/include/uapi/linux/mroute.h
+++ b/include/uapi/linux/mroute.h
@@ -28,12 +28,17 @@
 #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_FLUSH	(MRT_BASE+12)	/* Flush all multicast entries and vifs	*/
+#define MRT_MAX		(MRT_BASE+12)
 
 #define SIOCGETVIFCNT	SIOCPROTOPRIVATE	/* IP protocol privates */
 #define SIOCGETSGCNT	(SIOCPROTOPRIVATE+1)
 #define SIOCGETRPF	(SIOCPROTOPRIVATE+2)
 
+/* Flags used for MRT_FLUSH */
+#define MRT_FLUSH_ENTRIES	1	/* For flushing all multicast entries */
+#define MRT_FLUSH_VIFS		2	/* For flushing all multicast vifs */
+
 #define MAXVIFS		32
 typedef unsigned long vifbitmap_t;	/* User mode code depends on this lot */
 typedef unsigned short vifi_t;
diff --git a/include/uapi/linux/mroute6.h b/include/uapi/linux/mroute6.h
index 9999cc006390..b04094d997c8 100644
--- a/include/uapi/linux/mroute6.h
+++ b/include/uapi/linux/mroute6.h
@@ -31,12 +31,17 @@
 #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_FLUSH	(MRT6_BASE+12)	/* Flush all multicast entries and vifs	*/
+#define MRT6_MAX	(MRT6_BASE+12)
 
 #define SIOCGETMIFCNT_IN6	SIOCPROTOPRIVATE	/* IP protocol privates */
 #define SIOCGETSGCNT_IN6	(SIOCPROTOPRIVATE+1)
 #define SIOCGETRPF	(SIOCPROTOPRIVATE+2)
 
+/* Flags used for MRT6_FLUSH*/
+#define MRT6_FLUSH_ENTRIES	1	/* For flushing all multicast entries */
+#define MRT6_FLUSH_VIFS		2	/* For flushing all multicast vifs */
+
 #define MAXMIFS		32
 typedef unsigned long mifbitmap_t;	/* User mode code depends on this lot */
 typedef unsigned short mifi_t;
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index ddbf8c9a1abb..2eb569138569 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -416,7 +416,7 @@ static struct mr_table *ipmr_new_table(struct net *net, u32 id)
 static void ipmr_free_table(struct mr_table *mrt)
 {
 	del_timer_sync(&mrt->ipmr_expire_timer);
-	mroute_clean_tables(mrt, true);
+	mroute_clean_tables(mrt, true, MRT_FLUSH_VIFS | MRT_FLUSH_ENTRIES);
 	rhltable_destroy(&mrt->mfc_hash);
 	kfree(mrt);
 }
@@ -1299,44 +1299,48 @@ static int ipmr_mfc_add(struct net *net, struct mr_table *mrt,
 }
 
 /* Close the multicast socket, and clear the vif tables etc */
-static void mroute_clean_tables(struct mr_table *mrt, bool all)
+static void mroute_clean_tables(struct mr_table *mrt, bool all, int flags)
 {
 	struct net *net = read_pnet(&mrt->net);
-	struct mr_mfc *c, *tmp;
 	struct mfc_cache *cache;
+	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;
-		vif_delete(mrt, i, 0, &list);
+	if (flags & MRT_FLUSH_VIFS) {
+		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);
 	}
-	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;
-		rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
-		list_del_rcu(&c->list);
-		cache = (struct mfc_cache *)c;
-		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
-					      mrt->id);
-		mroute_netlink_event(mrt, cache, RTM_DELROUTE);
-		mr_cache_put(c);
-	}
-
-	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
-		spin_lock_bh(&mfc_unres_lock);
-		list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
-			list_del(&c->list);
+	if (flags & MRT_FLUSH_ENTRIES) {
+		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
+			if (!all && (c->mfc_flags & MFC_STATIC))
+				continue;
+			rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
+			list_del_rcu(&c->list);
 			cache = (struct mfc_cache *)c;
+			call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
+										  mrt->id);
 			mroute_netlink_event(mrt, cache, RTM_DELROUTE);
-			ipmr_destroy_unres(mrt, cache);
+			mr_cache_put(c);
+		}
+
+		if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
+			spin_lock_bh(&mfc_unres_lock);
+			list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
+				list_del(&c->list);
+				cache = (struct mfc_cache *)c;
+				mroute_netlink_event(mrt, cache, RTM_DELROUTE);
+				ipmr_destroy_unres(mrt, cache);
+			}
+			spin_unlock_bh(&mfc_unres_lock);
 		}
-		spin_unlock_bh(&mfc_unres_lock);
 	}
 }
 
@@ -1357,7 +1361,7 @@ static void mrtsock_destruct(struct sock *sk)
 						    NETCONFA_IFINDEX_ALL,
 						    net->ipv4.devconf_all);
 			RCU_INIT_POINTER(mrt->mroute_sk, NULL);
-			mroute_clean_tables(mrt, false);
+			mroute_clean_tables(mrt, false, MRT_FLUSH_VIFS | MRT_FLUSH_ENTRIES);
 		}
 	}
 	rtnl_unlock();
@@ -1482,6 +1486,17 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
 					   sk == rtnl_dereference(mrt->mroute_sk),
 					   parent);
 		break;
+	case MRT_FLUSH:
+		if (get_user(val, (int __user *)optval)) {
+			ret = -EFAULT;
+			break;
+		}
+		rtnl_lock();
+		ipmr_for_each_table(mrt, net) {
+			mroute_clean_tables(mrt, true, val);
+		}
+		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..473c83d197fe 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -393,7 +393,7 @@ static struct mr_table *ip6mr_new_table(struct net *net, u32 id)
 static void ip6mr_free_table(struct mr_table *mrt)
 {
 	del_timer_sync(&mrt->ipmr_expire_timer);
-	mroute_clean_tables(mrt, true);
+	mroute_clean_tables(mrt, true, MRT6_FLUSH_VIFS | MRT6_FLUSH_ENTRIES);
 	rhltable_destroy(&mrt->mfc_hash);
 	kfree(mrt);
 }
@@ -1496,43 +1496,47 @@ static int ip6mr_mfc_add(struct net *net, struct mr_table *mrt,
  *	Close the multicast socket, and clear the vif tables etc
  */
 
-static void mroute_clean_tables(struct mr_table *mrt, bool all)
+static void mroute_clean_tables(struct mr_table *mrt, bool all, int flags)
 {
 	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);
+	if (flags & MRT6_FLUSH_VIFS) {
+		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);
 	}
-	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;
-		rhltable_remove(&mrt->mfc_hash, &c->mnode, ip6mr_rht_params);
-		list_del_rcu(&c->list);
-		mr6_netlink_event(mrt, (struct mfc6_cache *)c, RTM_DELROUTE);
-		mr_cache_put(c);
-	}
+	if (flags & MRT6_FLUSH_ENTRIES) {
+		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
+			if (!all && (c->mfc_flags & MFC_STATIC))
+				continue;
+			rhltable_remove(&mrt->mfc_hash, &c->mnode, ip6mr_rht_params);
+			list_del_rcu(&c->list);
+			mr6_netlink_event(mrt, (struct mfc6_cache *)c, RTM_DELROUTE);
+			mr_cache_put(c);
+		}
 
-	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
-		spin_lock_bh(&mfc_unres_lock);
-		list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
-			list_del(&c->list);
-			call_ip6mr_mfc_entry_notifiers(read_pnet(&mrt->net),
-						       FIB_EVENT_ENTRY_DEL,
-						       (struct mfc6_cache *)c,
-						       mrt->id);
-			mr6_netlink_event(mrt, (struct mfc6_cache *)c,
-					  RTM_DELROUTE);
-			ip6mr_destroy_unres(mrt, (struct mfc6_cache *)c);
+		if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
+			spin_lock_bh(&mfc_unres_lock);
+			list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
+				list_del(&c->list);
+				call_ip6mr_mfc_entry_notifiers(read_pnet(&mrt->net),
+											   FIB_EVENT_ENTRY_DEL,
+											   (struct mfc6_cache *)c,
+											   mrt->id);
+				mr6_netlink_event(mrt, (struct mfc6_cache *)c,
+						  RTM_DELROUTE);
+				ip6mr_destroy_unres(mrt, (struct mfc6_cache *)c);
+			}
+			spin_unlock_bh(&mfc_unres_lock);
 		}
-		spin_unlock_bh(&mfc_unres_lock);
 	}
 }
 
@@ -1588,7 +1592,7 @@ int ip6mr_sk_done(struct sock *sk)
 						     NETCONFA_IFINDEX_ALL,
 						     net->ipv6.devconf_all);
 
-			mroute_clean_tables(mrt, false);
+			mroute_clean_tables(mrt, false, MRT6_FLUSH_VIFS | MRT6_FLUSH_ENTRIES);
 			err = 0;
 			break;
 		}
@@ -1703,6 +1707,19 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, uns
 					    parent);
 		rtnl_unlock();
 		return ret;
+	case MRT6_DEL_MFC_ALL:
+	{
+		int flags;
+
+		if (get_user(flags, (int __user *)optval))
+			return -EFAULT;
+		rtnl_lock();
+		ip6mr_for_each_table(mrt, net) {
+			mroute_clean_tables(mrt, true, flags);
+		}
+		rtnl_unlock();
+		return 0;
+	}
 
 	/*
 	 *	Control PIM assert (to activate pim will activate assert)
-- 
2.20.1

Re: [PATCH] ipmr: ip6mr: Create new sockopt to clear mfc cache only

[David Miller]

From: Callum Sinclair <callum.sinclair@alliedtelesis.co.nz>
Date: Thu, 31 Jan 2019 09:52:09 +1300

>  
> -/* 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 net *net = read_pnet(&mrt->net);

Please do not change the order of local variables like this, you're breaking
the correct reverse christmas tree ordering of longest to shortest line for
local variable declarations.

Thanks.

[PATCH] ipmr: ip6mr: Create new sockopt to clear mfc cache only

[Callum Sinclair]

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.sinclair@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(-)

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..b996d0f70e5c 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 net *net = read_pnet(&mrt->net);
 
 	/* 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)
-- 
2.20.1

[PATCH] ipmr: ip6mr: Create new sockopt to clear mfc cache only

[Callum Sinclair]

Created a way to clear the multicast forwarding cache on a socket
without having to either remove the entries manually using the delete
entry socket option or destroy and recreate the multicast socket.

Patch Set 2:
  - Fix Compile Errors

Callum Sinclair (1):
  ipmr: ip6mr: Create new sockopt to clear mfc cache only

 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(-)

-- 
2.20.1

Re: [PATCH] ipmr: ip6mr: Create new sockopt to clear mfc cache only

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 4146 bytes --]

Hi Callum,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net/master]
[also build test ERROR on v5.0-rc4 next-20190129]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Callum-Sinclair/ipmr-ip6mr-Create-new-sockopt-to-clear-mfc-cache-only/20190130-104146
config: i386-defconfig (attached as .config)
compiler: gcc-8 (Debian 8.2.0-14) 8.2.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All errors (new ones prefixed by >>):

   net/ipv4/ipmr.c: In function 'mroute_clean_cache':
>> net/ipv4/ipmr.c:1312:3: error: 'cache' undeclared (first use in this function); did you mean 'hh_cache'?
      cache = (struct mfc_cache *)c;
      ^~~~~
      hh_cache
   net/ipv4/ipmr.c:1312:3: note: each undeclared identifier is reported only once for each function it appears in
>> net/ipv4/ipmr.c:1313:33: error: 'net' undeclared (first use in this function)
      call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
                                    ^~~
   net/ipv4/ipmr.c: In function 'mroute_clean_tables':
   net/ipv4/ipmr.c:1334:14: warning: unused variable 'net' [-Wunused-variable]
     struct net *net = read_pnet(&mrt->net);
                 ^~~

vim +1312 net/ipv4/ipmr.c

^1da177e4 Linus Torvalds      2005-04-16  1300  
7ba7b80d1 Callum Sinclair     2019-01-30  1301  /* Clear the vif tables */
7ba7b80d1 Callum Sinclair     2019-01-30  1302  static void mroute_clean_cache(struct mr_table *mrt, bool all)
^1da177e4 Linus Torvalds      2005-04-16  1303  {
494fff563 Yuval Mintz         2018-02-28  1304  	struct mr_mfc *c, *tmp;
^1da177e4 Linus Torvalds      2005-04-16  1305  
a8cb16dd9 Eric Dumazet        2010-10-01  1306  	/* Wipe the cache */
8fb472c09 Nikolay Aleksandrov 2017-01-12  1307  	list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
0e615e960 Nikolay Aleksandrov 2015-11-20  1308  		if (!all && (c->mfc_flags & MFC_STATIC))
^1da177e4 Linus Torvalds      2005-04-16  1309  			continue;
8fb472c09 Nikolay Aleksandrov 2017-01-12  1310  		rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
a8c9486b8 Eric Dumazet        2010-10-01  1311  		list_del_rcu(&c->list);
494fff563 Yuval Mintz         2018-02-28 @1312  		cache = (struct mfc_cache *)c;
494fff563 Yuval Mintz         2018-02-28 @1313  		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
b362053a7 Yotam Gigi          2017-09-27  1314  					      mrt->id);
494fff563 Yuval Mintz         2018-02-28  1315  		mroute_netlink_event(mrt, cache, RTM_DELROUTE);
8c13af2a2 Yuval Mintz         2018-03-26  1316  		mr_cache_put(c);
^1da177e4 Linus Torvalds      2005-04-16  1317  	}
^1da177e4 Linus Torvalds      2005-04-16  1318  
0c12295a7 Patrick McHardy     2010-04-13  1319  	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
^1da177e4 Linus Torvalds      2005-04-16  1320  		spin_lock_bh(&mfc_unres_lock);
8fb472c09 Nikolay Aleksandrov 2017-01-12  1321  		list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
862465f2e Patrick McHardy     2010-04-13  1322  			list_del(&c->list);
494fff563 Yuval Mintz         2018-02-28  1323  			cache = (struct mfc_cache *)c;
494fff563 Yuval Mintz         2018-02-28  1324  			mroute_netlink_event(mrt, cache, RTM_DELROUTE);
494fff563 Yuval Mintz         2018-02-28  1325  			ipmr_destroy_unres(mrt, cache);
^1da177e4 Linus Torvalds      2005-04-16  1326  		}
^1da177e4 Linus Torvalds      2005-04-16  1327  		spin_unlock_bh(&mfc_unres_lock);
^1da177e4 Linus Torvalds      2005-04-16  1328  	}
^1da177e4 Linus Torvalds      2005-04-16  1329  }
^1da177e4 Linus Torvalds      2005-04-16  1330  

:::::: The code at line 1312 was first introduced by commit
:::::: 494fff56379c4ad5b8fe36a5b7ffede4044ca7bb ipmr, ip6mr: Make mfc_cache a common structure

:::::: TO: Yuval Mintz <yuvalm@mellanox.com>
:::::: CC: David S. Miller <davem@davemloft.net>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 26942 bytes --]

Re: [PATCH] ipmr: ip6mr: Create new sockopt to clear mfc cache only

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 4325 bytes --]

Hi Callum,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on net/master]
[also build test ERROR on v5.0-rc4 next-20190129]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Callum-Sinclair/ipmr-ip6mr-Create-new-sockopt-to-clear-mfc-cache-only/20190130-104146
config: arm-allmodconfig (attached as .config)
compiler: arm-linux-gnueabi-gcc (Debian 8.2.0-11) 8.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=8.2.0 make.cross ARCH=arm 

All errors (new ones prefixed by >>):

   net/ipv4/ipmr.c: In function 'mroute_clean_cache':
>> net/ipv4/ipmr.c:1312:3: error: 'cache' undeclared (first use in this function); did you mean 'cacheid'?
      cache = (struct mfc_cache *)c;
      ^~~~~
      cacheid
   net/ipv4/ipmr.c:1312:3: note: each undeclared identifier is reported only once for each function it appears in
   net/ipv4/ipmr.c:1313:33: error: 'net' undeclared (first use in this function)
      call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
                                    ^~~
   net/ipv4/ipmr.c: In function 'mroute_clean_tables':
   net/ipv4/ipmr.c:1334:14: warning: unused variable 'net' [-Wunused-variable]
     struct net *net = read_pnet(&mrt->net);
                 ^~~

vim +1312 net/ipv4/ipmr.c

^1da177e4 Linus Torvalds      2005-04-16  1300  
7ba7b80d1 Callum Sinclair     2019-01-30  1301  /* Clear the vif tables */
7ba7b80d1 Callum Sinclair     2019-01-30  1302  static void mroute_clean_cache(struct mr_table *mrt, bool all)
^1da177e4 Linus Torvalds      2005-04-16  1303  {
494fff563 Yuval Mintz         2018-02-28  1304  	struct mr_mfc *c, *tmp;
^1da177e4 Linus Torvalds      2005-04-16  1305  
a8cb16dd9 Eric Dumazet        2010-10-01  1306  	/* Wipe the cache */
8fb472c09 Nikolay Aleksandrov 2017-01-12  1307  	list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
0e615e960 Nikolay Aleksandrov 2015-11-20  1308  		if (!all && (c->mfc_flags & MFC_STATIC))
^1da177e4 Linus Torvalds      2005-04-16  1309  			continue;
8fb472c09 Nikolay Aleksandrov 2017-01-12  1310  		rhltable_remove(&mrt->mfc_hash, &c->mnode, ipmr_rht_params);
a8c9486b8 Eric Dumazet        2010-10-01  1311  		list_del_rcu(&c->list);
494fff563 Yuval Mintz         2018-02-28 @1312  		cache = (struct mfc_cache *)c;
494fff563 Yuval Mintz         2018-02-28  1313  		call_ipmr_mfc_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, cache,
b362053a7 Yotam Gigi          2017-09-27  1314  					      mrt->id);
494fff563 Yuval Mintz         2018-02-28  1315  		mroute_netlink_event(mrt, cache, RTM_DELROUTE);
8c13af2a2 Yuval Mintz         2018-03-26  1316  		mr_cache_put(c);
^1da177e4 Linus Torvalds      2005-04-16  1317  	}
^1da177e4 Linus Torvalds      2005-04-16  1318  
0c12295a7 Patrick McHardy     2010-04-13  1319  	if (atomic_read(&mrt->cache_resolve_queue_len) != 0) {
^1da177e4 Linus Torvalds      2005-04-16  1320  		spin_lock_bh(&mfc_unres_lock);
8fb472c09 Nikolay Aleksandrov 2017-01-12  1321  		list_for_each_entry_safe(c, tmp, &mrt->mfc_unres_queue, list) {
862465f2e Patrick McHardy     2010-04-13  1322  			list_del(&c->list);
494fff563 Yuval Mintz         2018-02-28  1323  			cache = (struct mfc_cache *)c;
494fff563 Yuval Mintz         2018-02-28  1324  			mroute_netlink_event(mrt, cache, RTM_DELROUTE);
494fff563 Yuval Mintz         2018-02-28  1325  			ipmr_destroy_unres(mrt, cache);
^1da177e4 Linus Torvalds      2005-04-16  1326  		}
^1da177e4 Linus Torvalds      2005-04-16  1327  		spin_unlock_bh(&mfc_unres_lock);
^1da177e4 Linus Torvalds      2005-04-16  1328  	}
^1da177e4 Linus Torvalds      2005-04-16  1329  }
^1da177e4 Linus Torvalds      2005-04-16  1330  

:::::: The code at line 1312 was first introduced by commit
:::::: 494fff56379c4ad5b8fe36a5b7ffede4044ca7bb ipmr, ip6mr: Make mfc_cache a common structure

:::::: TO: Yuval Mintz <yuvalm@mellanox.com>
:::::: CC: David S. Miller <davem@davemloft.net>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 68417 bytes --]

[PATCH] ipmr: ip6mr: Create new sockopt to clear mfc cache only

[Callum Sinclair]

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.sinclair@alliedtelesis.co.nz>
---
 include/uapi/linux/mroute.h  |  3 ++-
 include/uapi/linux/mroute6.h |  3 ++-
 net/ipv4/ipmr.c              | 41 +++++++++++++++++++++-----------
 net/ipv6/ip6mr.c             | 45 +++++++++++++++++++++++-------------
 4 files changed, 60 insertions(+), 32 deletions(-)

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..bbbce5ec8a0c 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1298,22 +1298,10 @@ 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);
 
 	/* Wipe the cache */
 	list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
@@ -1340,6 +1328,24 @@ 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)
+{
+	struct net *net = read_pnet(&mrt->net);
+	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 +1488,13 @@ 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..64631f85dcf4 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;
@@ -1535,6 +1521,26 @@ static void mroute_clean_tables(struct mr_table *mrt, bool all)
 		spin_unlock_bh(&mfc_unres_lock);
 	}
 }
+/*
+ *	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)
 {
@@ -1703,6 +1709,13 @@ 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)
-- 
2.20.1

[PATCH] ipmr: ip6mr: Create new sockopt to clear mfc cache only

[Callum Sinclair]

Created a way to clear the multicast forwarding cache on a socket
without having to either remove the entries manually using the delete
entry socket option or destroy and recreate the multicast socket.

Callum Sinclair (1):
  ipmr: ip6mr: Create new sockopt to clear mfc cache only

 include/uapi/linux/mroute.h  |  3 ++-
 include/uapi/linux/mroute6.h |  3 ++-
 net/ipv4/ipmr.c              | 41 +++++++++++++++++++++-----------
 net/ipv6/ip6mr.c             | 45 +++++++++++++++++++++++-------------
 4 files changed, 60 insertions(+), 32 deletions(-)

-- 
2.20.1