[PATCH net-next] ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs

[PATCH net-next] ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs

[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.

Using the flags MRT_FLUSH_ENTRIES and MRT_FLUSH_VIFS, all multicast
entries can be cleared, all multicast interfaces can be closed or both
can be cleared using one sockopt call.

Patch Set 2:
  - Created new flags to flush static entries or vifs

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

 include/uapi/linux/mroute.h  |  9 ++++-
 include/uapi/linux/mroute6.h |  9 ++++-
 net/ipv4/ipmr.c              | 71 ++++++++++++++++++++-------------
 net/ipv6/ip6mr.c             | 76 +++++++++++++++++++++++-------------
 4 files changed, 108 insertions(+), 57 deletions(-)

-- 
2.20.1

[PATCH net-next] ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs

[Callum Sinclair]

Currently the only way to clear the forwarding 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. The new socket option
MRT_FLUSH_ENTRIES will clear all multicast entries on the sockets table
and the MRT_FLUSH_VIFS will delete all multicast vifs on the socket
table.

Signed-off-by: Callum Sinclair <callum.sinclair@alliedtelesis.co.nz>
---
 include/uapi/linux/mroute.h  |  9 ++++-
 include/uapi/linux/mroute6.h |  9 ++++-
 net/ipv4/ipmr.c              | 71 ++++++++++++++++++++-------------
 net/ipv6/ip6mr.c             | 76 +++++++++++++++++++++++-------------
 4 files changed, 108 insertions(+), 57 deletions(-)

diff --git a/include/uapi/linux/mroute.h b/include/uapi/linux/mroute.h
index 5d37a9ccce63..6b556ed7e252 100644
--- a/include/uapi/linux/mroute.h
+++ b/include/uapi/linux/mroute.h
@@ -28,12 +28,19 @@
 #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 mfc entries and/or vifs	*/
+#define MRT_MAX		(MRT_BASE+12)
 
 #define SIOCGETVIFCNT	SIOCPROTOPRIVATE	/* IP protocol privates */
 #define SIOCGETSGCNT	(SIOCPROTOPRIVATE+1)
 #define SIOCGETRPF	(SIOCPROTOPRIVATE+2)
 
+/* MRT_FLUSH optional flags */
+#define MRT_FLUSH_MFC	1	/* Flush multicast entries */
+#define MRT_FLUSH_MFC_STATIC	2	/* Flush static multicast entries */
+#define MRT_FLUSH_VIFS	3	/* Flush multicast vifs */
+#define MRT_FLUSH_VIFS_STATIC	4	/* Flush static 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..47a32c78cbea 100644
--- a/include/uapi/linux/mroute6.h
+++ b/include/uapi/linux/mroute6.h
@@ -31,12 +31,19 @@
 #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 mfc entries and/or vifs	*/
+#define MRT6_MAX	(MRT6_BASE+12)
 
 #define SIOCGETMIFCNT_IN6	SIOCPROTOPRIVATE	/* IP protocol privates */
 #define SIOCGETSGCNT_IN6	(SIOCPROTOPRIVATE+1)
 #define SIOCGETRPF	(SIOCPROTOPRIVATE+2)
 
+/* MRT6_FLUSH optional flags */
+#define MRT6_FLUSH_MFC	1	/* Flush multicast entries */
+#define MRT6_FLUSH_MFC_STATIC	2	/* Flush static multicast entries */
+#define MRT6_FLUSH_VIFS	3	/* Flushing multicast vifs */
+#define MRT6_FLUSH_VIFS_STATIC	4	/* Flush static 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 e536970557dd..0cbd0ed4ffff 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -110,7 +110,7 @@ static int ipmr_cache_report(struct mr_table *mrt,
 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
 				 int cmd);
 static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
-static void mroute_clean_tables(struct mr_table *mrt, bool all);
+static void mroute_clean_tables(struct mr_table *mrt, bool all, int flags);
 static void ipmr_expire_process(struct timer_list *t);
 
 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
@@ -415,7 +415,7 @@ 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_MFC);
 	rhltable_destroy(&mrt->mfc_hash);
 	kfree(mrt);
 }
@@ -1296,7 +1296,7 @@ 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;
@@ -1305,35 +1305,41 @@ static void mroute_clean_tables(struct mr_table *mrt, bool all)
 	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 ((mrt->vif_table[i].flags & VIFF_STATIC) &&
+			   !(all && (flags & MRT_FLUSH_VIFS_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_MFC) {
+		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
+			if ((c->mfc_flags & MFC_STATIC) &&
+				!(all && (flags & MRT_FLUSH_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);
 	}
 }
 
@@ -1354,7 +1360,7 @@ 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_MFC);
 		}
 	}
 	rtnl_unlock();
@@ -1479,6 +1485,17 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
 					   sk == rtnl_dereference(mrt->mroute_sk),
 					   parent);
 		break;
+	case MRT_FLUSH:
+		if (optlen != sizeof(val)) {
+			ret = -EINVAL;
+			break;
+		}
+		if (get_user(val, (int __user *)optval)) {
+			ret = -EFAULT;
+			break;
+		}
+		mroute_clean_tables(mrt, false, val);
+		break;
 	/* Control PIM assert. */
 	case MRT_ASSERT:
 		if (optlen != sizeof(val)) {
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index cc01aa3f2b5e..31041d4332bc 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -97,7 +97,7 @@ static void mr6_netlink_event(struct mr_table *mrt, struct mfc6_cache *mfc,
 static void mrt6msg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
 static int ip6mr_rtm_dumproute(struct sk_buff *skb,
 			       struct netlink_callback *cb);
-static void mroute_clean_tables(struct mr_table *mrt, bool all);
+static void mroute_clean_tables(struct mr_table *mrt, bool all, int flags);
 static void ipmr_expire_process(struct timer_list *t);
 
 #ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
@@ -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_MFC);
 	rhltable_destroy(&mrt->mfc_hash);
 	kfree(mrt);
 }
@@ -1496,42 +1496,48 @@ 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 ((mrt->vif_table[i].flags & VIFF_STATIC) &&
+			    !(all && (flags & MRT6_FLUSH_VIFS_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);
-		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);
-		mr_cache_put(c);
-	}
+	if (flags & MRT6_FLUSH_MFC) {
+		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
+			if ((c->mfc_flags & MFC_STATIC) &&
+				!(all && (flags & MRT6_FLUSH_MFC_STATIC)))
+				continue;
+			rhltable_remove(&mrt->mfc_hash, &c->mnode, ip6mr_rht_params);
+			list_del_rcu(&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);
+			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);
-			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);
+				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);
 	}
 }
 
@@ -1587,7 +1593,7 @@ 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_MFC);
 			err = 0;
 			break;
 		}
@@ -1703,6 +1709,20 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, uns
 		rtnl_unlock();
 		return ret;
 
+	case MRT6_FLUSH:
+	{
+		int flags;
+
+		if (optlen != sizeof(flags))
+			return -EINVAL;
+		if (get_user(flags, (int __user *)optval))
+			return -EFAULT;
+		rtnl_lock();
+		mroute_clean_tables(mrt, true, flags);
+		rtnl_unlock();
+		return 0;
+	}
+
 	/*
 	 *	Control PIM assert (to activate pim will activate assert)
 	 */
-- 
2.20.1

Re: [PATCH net-next] ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs

[Nikolay Aleksandrov]

On 2/11/19 12:12 AM, Callum Sinclair wrote:
> Currently the only way to clear the forwarding 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. The new socket option
> MRT_FLUSH_ENTRIES will clear all multicast entries on the sockets table
> and the MRT_FLUSH_VIFS will delete all multicast vifs on the socket
> table.
> 
> Signed-off-by: Callum Sinclair <callum.sinclair@alliedtelesis.co.nz>
> ---
>  include/uapi/linux/mroute.h  |  9 ++++-
>  include/uapi/linux/mroute6.h |  9 ++++-
>  net/ipv4/ipmr.c              | 71 ++++++++++++++++++++-------------
>  net/ipv6/ip6mr.c             | 76 +++++++++++++++++++++++-------------
>  4 files changed, 108 insertions(+), 57 deletions(-)
> 

Hi,
How could 3 be a flag ? How was this tested exactly ?

I think you can remove the "all" argument altogether and just use the
flags. Also for each iteration of this patch please add a version (as in
v1, v2 etc after net-next in the subject) and in the commit message explain what
has changed between versions like v1 -> v2: fixed blah.
And what happens if we only specify VIFF_STATIC without VIFF or just MFC_STATIC without MFC ?
I see how these work as kind of sub-flags, but there is no explanation of the intended
behaviour nor justification, in fact the commit message is wrong - MRT_FLUSH_ENTRIES
will not clean all and actually there is no MRT_FLUSH_ENTRIES flag or call.

Also please CC all of the people who reviewed previous versions like
Nicolas Dichtel.

A few more comments inline below.

Thanks,
 Nik

> diff --git a/include/uapi/linux/mroute.h b/include/uapi/linux/mroute.h
> index 5d37a9ccce63..6b556ed7e252 100644
> --- a/include/uapi/linux/mroute.h
> +++ b/include/uapi/linux/mroute.h
> @@ -28,12 +28,19 @@
>  #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 mfc entries and/or vifs	*/
> +#define MRT_MAX		(MRT_BASE+12)
>  
>  #define SIOCGETVIFCNT	SIOCPROTOPRIVATE	/* IP protocol privates */
>  #define SIOCGETSGCNT	(SIOCPROTOPRIVATE+1)
>  #define SIOCGETRPF	(SIOCPROTOPRIVATE+2)
>  
> +/* MRT_FLUSH optional flags */
> +#define MRT_FLUSH_MFC	1	/* Flush multicast entries */
> +#define MRT_FLUSH_MFC_STATIC	2	/* Flush static multicast entries */
> +#define MRT_FLUSH_VIFS	3	/* Flush multicast vifs */
> +#define MRT_FLUSH_VIFS_STATIC	4	/* Flush static 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..47a32c78cbea 100644
> --- a/include/uapi/linux/mroute6.h
> +++ b/include/uapi/linux/mroute6.h
> @@ -31,12 +31,19 @@
>  #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 mfc entries and/or vifs	*/
> +#define MRT6_MAX	(MRT6_BASE+12)
>  
>  #define SIOCGETMIFCNT_IN6	SIOCPROTOPRIVATE	/* IP protocol privates */
>  #define SIOCGETSGCNT_IN6	(SIOCPROTOPRIVATE+1)
>  #define SIOCGETRPF	(SIOCPROTOPRIVATE+2)
>  
> +/* MRT6_FLUSH optional flags */
> +#define MRT6_FLUSH_MFC	1	/* Flush multicast entries */
> +#define MRT6_FLUSH_MFC_STATIC	2	/* Flush static multicast entries */
> +#define MRT6_FLUSH_VIFS	3	/* Flushing multicast vifs */
> +#define MRT6_FLUSH_VIFS_STATIC	4	/* Flush static 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 e536970557dd..0cbd0ed4ffff 100644
> --- a/net/ipv4/ipmr.c
> +++ b/net/ipv4/ipmr.c
> @@ -110,7 +110,7 @@ static int ipmr_cache_report(struct mr_table *mrt,
>  static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
>  				 int cmd);
>  static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
> -static void mroute_clean_tables(struct mr_table *mrt, bool all);
> +static void mroute_clean_tables(struct mr_table *mrt, bool all, int flags);
>  static void ipmr_expire_process(struct timer_list *t);
>  
>  #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
> @@ -415,7 +415,7 @@ 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_MFC);
>  	rhltable_destroy(&mrt->mfc_hash);
>  	kfree(mrt);
>  }
> @@ -1296,7 +1296,7 @@ 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;
> @@ -1305,35 +1305,41 @@ static void mroute_clean_tables(struct mr_table *mrt, bool all)
>  	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 ((mrt->vif_table[i].flags & VIFF_STATIC) &&
> +			   !(all && (flags & MRT_FLUSH_VIFS_STATIC)))

nit: the ! must be 1 more space further (below the second bracket after if).


> +				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_MFC) {
> +		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
> +			if ((c->mfc_flags & MFC_STATIC) &&
> +				!(all && (flags & MRT_FLUSH_MFC_STATIC)))

again wrong indentation, the ! must be below the second bracket after the if (the
first character of the condition).

> +				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);

again wrong indentation

>  			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);
>  	}
>  }
>  
> @@ -1354,7 +1360,7 @@ 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_MFC);
>  		}
>  	}
>  	rtnl_unlock();
> @@ -1479,6 +1485,17 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
>  					   sk == rtnl_dereference(mrt->mroute_sk),
>  					   parent);
>  		break;
> +	case MRT_FLUSH:
> +		if (optlen != sizeof(val)) {
> +			ret = -EINVAL;
> +			break;
> +		}
> +		if (get_user(val, (int __user *)optval)) {
> +			ret = -EFAULT;
> +			break;
> +		}
> +		mroute_clean_tables(mrt, false, val);
> +		break;
>  	/* Control PIM assert. */
>  	case MRT_ASSERT:
>  		if (optlen != sizeof(val)) {
> diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
> index cc01aa3f2b5e..31041d4332bc 100644
> --- a/net/ipv6/ip6mr.c
> +++ b/net/ipv6/ip6mr.c
> @@ -97,7 +97,7 @@ static void mr6_netlink_event(struct mr_table *mrt, struct mfc6_cache *mfc,
>  static void mrt6msg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
>  static int ip6mr_rtm_dumproute(struct sk_buff *skb,
>  			       struct netlink_callback *cb);
> -static void mroute_clean_tables(struct mr_table *mrt, bool all);
> +static void mroute_clean_tables(struct mr_table *mrt, bool all, int flags);
>  static void ipmr_expire_process(struct timer_list *t);
>  
>  #ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
> @@ -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_MFC);
>  	rhltable_destroy(&mrt->mfc_hash);
>  	kfree(mrt);
>  }
> @@ -1496,42 +1496,48 @@ 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 ((mrt->vif_table[i].flags & VIFF_STATIC) &&
> +			    !(all && (flags & MRT6_FLUSH_VIFS_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);
> -		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);
> -		mr_cache_put(c);
> -	}
> +	if (flags & MRT6_FLUSH_MFC) {
> +		list_for_each_entry_safe(c, tmp, &mrt->mfc_cache_list, list) {
> +			if ((c->mfc_flags & MFC_STATIC) &&
> +				!(all && (flags & MRT6_FLUSH_MFC_STATIC)))

wrong indentation

> +				continue;
> +			rhltable_remove(&mrt->mfc_hash, &c->mnode, ip6mr_rht_params);
> +			list_del_rcu(&c->list);
> +			call_ip6mr_mfc_entry_notifiers(read_pnet(&mrt->net),
> +										   FIB_EVENT_ENTRY_DEL,
> +										   (struct mfc6_cache *)c, mrt->id);

wrong indentation

> +			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);
> -			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);
> +				mr6_netlink_event(mrt, (struct mfc6_cache *)c,
> +								  RTM_DELROUTE);

wrong indentation

> +				ip6mr_destroy_unres(mrt, (struct mfc6_cache *)c);
> +			}
> +			spin_unlock_bh(&mfc_unres_lock);
>  		}
> -		spin_unlock_bh(&mfc_unres_lock);
>  	}
>  }
>  
> @@ -1587,7 +1593,7 @@ 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_MFC);
>  			err = 0;
>  			break;
>  		}
> @@ -1703,6 +1709,20 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, uns
>  		rtnl_unlock();
>  		return ret;
>  
> +	case MRT6_FLUSH:
> +	{
> +		int flags;
> +
> +		if (optlen != sizeof(flags))
> +			return -EINVAL;
> +		if (get_user(flags, (int __user *)optval))
> +			return -EFAULT;
> +		rtnl_lock();
> +		mroute_clean_tables(mrt, true, flags);
> +		rtnl_unlock();
> +		return 0;
> +	}
> +
>  	/*
>  	 *	Control PIM assert (to activate pim will activate assert)
>  	 */
> 

Re: [PATCH net-next] ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs

[Nikolay Aleksandrov]

On 08/02/2019 17:08, Nicolas Dichtel wrote:
> Le 08/02/2019 à 15:43, Nikolay Aleksandrov a écrit :
>> On 08/02/2019 16:18, Nicolas Dichtel wrote:
>>> Le 08/02/2019 à 05:11, Callum Sinclair a écrit :
>>>> Currently the only way to clear the mfc cache was to delete the entries
>>> mfc stands for 'multicast forwarding cache', so 'mfc cache' is a bit strange.
>>>
>>>> one by one using the MRT_DEL_MFC socket option or to destroy and
>>>> recreate the socket.
>>> Note that if entries were added with MRT_ADD_MFC_PROXY, they will survive to the
>>> socket destruction. This is not the case with your new cmd. Is it intended?
>>
>> I think you're referring to MFC_STATIC entries (sk != mroute_sk). It
>> doesn't matter how you add an entry - they all get cleaned up if added
>> through the mroute socket.
> Yes, right.
> MRT_FLUSH_MFC_STATIC ?
> 

Sounds good to me.

Re: [PATCH net-next] ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs

[Nicolas Dichtel]

Le 08/02/2019 à 15:43, Nikolay Aleksandrov a écrit :
> On 08/02/2019 16:18, Nicolas Dichtel wrote:
>> Le 08/02/2019 à 05:11, Callum Sinclair a écrit :
>>> Currently the only way to clear the mfc cache was to delete the entries
>> mfc stands for 'multicast forwarding cache', so 'mfc cache' is a bit strange.
>>
>>> one by one using the MRT_DEL_MFC socket option or to destroy and
>>> recreate the socket.
>> Note that if entries were added with MRT_ADD_MFC_PROXY, they will survive to the
>> socket destruction. This is not the case with your new cmd. Is it intended?
> 
> I think you're referring to MFC_STATIC entries (sk != mroute_sk). It
> doesn't matter how you add an entry - they all get cleaned up if added
> through the mroute socket.
Yes, right.
MRT_FLUSH_MFC_STATIC ?

Re: [PATCH net-next] ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs

[Nikolay Aleksandrov]

On 08/02/2019 16:18, Nicolas Dichtel wrote:
> Le 08/02/2019 à 05:11, Callum Sinclair a écrit :
>> Currently the only way to clear the mfc cache was to delete the entries
> mfc stands for 'multicast forwarding cache', so 'mfc cache' is a bit strange.
> 
>> one by one using the MRT_DEL_MFC socket option or to destroy and
>> recreate the socket.
> Note that if entries were added with MRT_ADD_MFC_PROXY, they will survive to the
> socket destruction. This is not the case with your new cmd. Is it intended?

I think you're referring to MFC_STATIC entries (sk != mroute_sk). It
doesn't matter how you add an entry - they all get cleaned up if added
through the mroute socket.

> Maybe a third option (something like MRT_FLUSH_MFC_PROXY) would be useful to
> avoid confusion?
> 
>>
>> Create a new socket option which will clear the multicast forwarding
>> cache on the socket without destroying the socket. The new socket option
>> MRT_FLUSH_ENTRIES will clear all multicast entries on the sockets table
>> and the MRT_FLUSH_VIFS will delete all multicast vifs on the socket
>> table.
>>
>> 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             | 74 ++++++++++++++++++++++--------------
>>  4 files changed, 100 insertions(+), 57 deletions(-)
>>
>> diff --git a/include/uapi/linux/mroute.h b/include/uapi/linux/mroute.h
>> index 5d37a9ccce63..673495ca3495 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	*/
> nit: "Flush all mfc entries and/or vifs" ?
> 
>> +#define MRT_MAX		(MRT_BASE+12)
>>  
>>  #define SIOCGETVIFCNT	SIOCPROTOPRIVATE	/* IP protocol privates */
>>  #define SIOCGETSGCNT	(SIOCPROTOPRIVATE+1)
>>  #define SIOCGETRPF	(SIOCPROTOPRIVATE+2)
>>  
>> +/* MRT_FLUSH optional flags */
>> +#define MRT_FLUSH_ENTRIES	1	/* For flushing all multicast entries */
> Maybe MRT_FLUSH_MFC is more consistent with the previous naming (MRT_ADD_MFC, etc.)
> 
> 
> Regards,
> Nicolas
> 

Re: [PATCH net-next] ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs

[Nicolas Dichtel]

Le 08/02/2019 à 05:11, Callum Sinclair a écrit :
> Currently the only way to clear the mfc cache was to delete the entries
mfc stands for 'multicast forwarding cache', so 'mfc cache' is a bit strange.

> one by one using the MRT_DEL_MFC socket option or to destroy and
> recreate the socket.
Note that if entries were added with MRT_ADD_MFC_PROXY, they will survive to the
socket destruction. This is not the case with your new cmd. Is it intended?
Maybe a third option (something like MRT_FLUSH_MFC_PROXY) would be useful to
avoid confusion?

> 
> Create a new socket option which will clear the multicast forwarding
> cache on the socket without destroying the socket. The new socket option
> MRT_FLUSH_ENTRIES will clear all multicast entries on the sockets table
> and the MRT_FLUSH_VIFS will delete all multicast vifs on the socket
> table.
> 
> 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             | 74 ++++++++++++++++++++++--------------
>  4 files changed, 100 insertions(+), 57 deletions(-)
> 
> diff --git a/include/uapi/linux/mroute.h b/include/uapi/linux/mroute.h
> index 5d37a9ccce63..673495ca3495 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	*/
nit: "Flush all mfc entries and/or vifs" ?

> +#define MRT_MAX		(MRT_BASE+12)
>  
>  #define SIOCGETVIFCNT	SIOCPROTOPRIVATE	/* IP protocol privates */
>  #define SIOCGETSGCNT	(SIOCPROTOPRIVATE+1)
>  #define SIOCGETRPF	(SIOCPROTOPRIVATE+2)
>  
> +/* MRT_FLUSH optional flags */
> +#define MRT_FLUSH_ENTRIES	1	/* For flushing all multicast entries */
Maybe MRT_FLUSH_MFC is more consistent with the previous naming (MRT_ADD_MFC, etc.)


Regards,
Nicolas

[PATCH net-next] ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs

[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. The new socket option
MRT_FLUSH_ENTRIES will clear all multicast entries on the sockets table
and the MRT_FLUSH_VIFS will delete all multicast vifs on the socket
table.

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             | 74 ++++++++++++++++++++++--------------
 4 files changed, 100 insertions(+), 57 deletions(-)

diff --git a/include/uapi/linux/mroute.h b/include/uapi/linux/mroute.h
index 5d37a9ccce63..673495ca3495 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)
 
+/* MRT_FLUSH optional flags */
+#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..1f7ac3f0bc20 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)
 
+/* MRT6_FLUSH optional flags */
+#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 e536970557dd..dc7a4ee1d7ca 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -110,7 +110,7 @@ static int ipmr_cache_report(struct mr_table *mrt,
 static void mroute_netlink_event(struct mr_table *mrt, struct mfc_cache *mfc,
 				 int cmd);
 static void igmpmsg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
-static void mroute_clean_tables(struct mr_table *mrt, bool all);
+static void mroute_clean_tables(struct mr_table *mrt, bool all, int flags);
 static void ipmr_expire_process(struct timer_list *t);
 
 #ifdef CONFIG_IP_MROUTE_MULTIPLE_TABLES
@@ -415,7 +415,7 @@ 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);
 }
@@ -1296,7 +1296,7 @@ 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;
@@ -1305,35 +1305,39 @@ static void mroute_clean_tables(struct mr_table *mrt, bool all)
 	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);
 	}
 }
 
@@ -1354,7 +1358,7 @@ 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();
@@ -1479,6 +1483,17 @@ int ip_mroute_setsockopt(struct sock *sk, int optname, char __user *optval,
 					   sk == rtnl_dereference(mrt->mroute_sk),
 					   parent);
 		break;
+	case MRT_FLUSH:
+		if (optlen != sizeof(val)) {
+			ret = -EINVAL;
+			break;
+		}
+		if (get_user(val, (int __user *)optval)) {
+			ret = -EFAULT;
+			break;
+		}
+		mroute_clean_tables(mrt, true, val);
+		break;
 	/* Control PIM assert. */
 	case MRT_ASSERT:
 		if (optlen != sizeof(val)) {
diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index cc01aa3f2b5e..01f015fb33f0 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -97,7 +97,7 @@ static void mr6_netlink_event(struct mr_table *mrt, struct mfc6_cache *mfc,
 static void mrt6msg_netlink_event(struct mr_table *mrt, struct sk_buff *pkt);
 static int ip6mr_rtm_dumproute(struct sk_buff *skb,
 			       struct netlink_callback *cb);
-static void mroute_clean_tables(struct mr_table *mrt, bool all);
+static void mroute_clean_tables(struct mr_table *mrt, bool all, int flags);
 static void ipmr_expire_process(struct timer_list *t);
 
 #ifdef CONFIG_IPV6_MROUTE_MULTIPLE_TABLES
@@ -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);
 }
@@ -1496,42 +1496,46 @@ 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);
-		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);
-		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);
+			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);
+			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);
-			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);
+				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);
 	}
 }
 
@@ -1587,7 +1591,7 @@ 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 +1707,20 @@ int ip6_mroute_setsockopt(struct sock *sk, int optname, char __user *optval, uns
 		rtnl_unlock();
 		return ret;
 
+	case MRT6_FLUSH:
+	{
+		int flags;
+
+		if (optlen != sizeof(flags))
+			return -EINVAL;
+		if (get_user(flags, (int __user *)optval))
+			return -EFAULT;
+		rtnl_lock();
+		mroute_clean_tables(mrt, true, flags);
+		rtnl_unlock();
+		return 0;
+	}
+
 	/*
 	 *	Control PIM assert (to activate pim will activate assert)
 	 */
-- 
2.20.1

[PATCH net-next] ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs

[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.

Using the flags MRT_FLUSH_ENTRIES and MRT_FLUSH_VIFS, all multicast
entries can be cleared, all multicast interfaces can be closed or both
can be cleared using one sockopt call.

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

 include/uapi/linux/mroute.h  |  7 +++-
 include/uapi/linux/mroute6.h |  7 +++-
 net/ipv4/ipmr.c              | 69 ++++++++++++++++++++-------------
 net/ipv6/ip6mr.c             | 74 ++++++++++++++++++++++--------------
 4 files changed, 100 insertions(+), 57 deletions(-)

-- 
2.20.1