Re: [PATCH net-next] ipmr: ip6mr: Create new sockopt to clear mfc cache or vifs
From: Nikolay Aleksandrov
Date: Sun Feb 10 2019 - 17:55:12 EST
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@xxxxxxxxxxxxxxxxxxx>
> ---
> 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)
> */
>