From: Geliang Tang geliang.tang@suse.com

The specifications from [1] about the "REMOVE" command say:

Announce that an address has been lost to the peer

It was then only supposed to send a RM_ADDR and not trying to delete associated subflows.

A new helper mptcp_pm_remove_addrs() is then introduced to do just that, compared to mptcp_pm_remove_addrs_and_subflows() also removing subflows.

To delete a subflow, the userspace daemon can use the "SUB_DESTROY" command, see mptcp_nl_cmd_sf_destroy().

Fixes: d9a4594edabf ("mptcp: netlink: Add MPTCP_PM_CMD_REMOVE") Link: https://github.com/multipath-tcp/mptcp/blob/mptcp_v0.96/include/uapi/linux/m... [1] Cc: stable@vger.kernel.org Reviewed-by: Matthieu Baerts matthieu.baerts@tessares.net Signed-off-by: Geliang Tang geliang.tang@suse.com Signed-off-by: Mat Martineau martineau@kernel.org --- net/mptcp/pm_netlink.c | 18 ++++++++++++++++++ net/mptcp/pm_userspace.c | 2 +- net/mptcp/protocol.h | 1 + 3 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index bc343dab5e3f..59f8f3124855 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -1558,6 +1558,24 @@ static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info) return ret; }

+void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list) +{ + struct mptcp_rm_list alist = { .nr = 0 }; + struct mptcp_pm_addr_entry *entry; + + list_for_each_entry(entry, rm_list, list) { + remove_anno_list_by_saddr(msk, &entry->addr); + if (alist.nr < MPTCP_RM_IDS_MAX) + alist.ids[alist.nr++] = entry->addr.id; + } + + if (alist.nr) { + spin_lock_bh(&msk->pm.lock); + mptcp_pm_remove_addr(msk, &alist); + spin_unlock_bh(&msk->pm.lock); + } +} + void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk, struct list_head *rm_list) { diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c index 27a275805c06..6beadea8c67d 100644 --- a/net/mptcp/pm_userspace.c +++ b/net/mptcp/pm_userspace.c @@ -232,7 +232,7 @@ int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)

list_move(&match->list, &free_list);

- mptcp_pm_remove_addrs_and_subflows(msk, &free_list); + mptcp_pm_remove_addrs(msk, &free_list);

release_sock((struct sock *)msk);

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index c5255258bfb3..70c957bc56a8 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -832,6 +832,7 @@ int mptcp_pm_announce_addr(struct mptcp_sock *msk, bool echo); int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list); int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list); +void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list); void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk, struct list_head *rm_list);

From: Geliang Tang geliang.tang@suse.com

Add the address into userspace_pm_local_addr_list when the subflow is created. Make sure it can be found in mptcp_nl_cmd_remove(). And delete it in the new helper mptcp_userspace_pm_delete_local_addr().

By doing this, the "REMOVE" command also works with subflows that have been created via the "SUB_CREATE" command instead of restricting to the addresses that have been announced via the "ANNOUNCE" command.

Fixes: d9a4594edabf ("mptcp: netlink: Add MPTCP_PM_CMD_REMOVE") Link: https://github.com/multipath-tcp/mptcp_net-next/issues/379 Cc: stable@vger.kernel.org Reviewed-by: Matthieu Baerts matthieu.baerts@tessares.net Signed-off-by: Geliang Tang geliang.tang@suse.com Signed-off-by: Mat Martineau martineau@kernel.org --- net/mptcp/pm_userspace.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+)

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c index 6beadea8c67d..114548b09f47 100644 --- a/net/mptcp/pm_userspace.c +++ b/net/mptcp/pm_userspace.c @@ -79,6 +79,30 @@ static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk, return ret; }

+/* If the subflow is closed from the other peer (not via a + * subflow destroy command then), we want to keep the entry + * not to assign the same ID to another address and to be + * able to send RM_ADDR after the removal of the subflow. + */ +static int mptcp_userspace_pm_delete_local_addr(struct mptcp_sock *msk, + struct mptcp_pm_addr_entry *addr) +{ + struct mptcp_pm_addr_entry *entry, *tmp; + + list_for_each_entry_safe(entry, tmp, &msk->pm.userspace_pm_local_addr_list, list) { + if (mptcp_addresses_equal(&entry->addr, &addr->addr, false)) { + /* TODO: a refcount is needed because the entry can + * be used multiple times (e.g. fullmesh mode). + */ + list_del_rcu(&entry->list); + kfree(entry); + return 0; + } + } + + return -EINVAL; +} + int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id, u8 *flags, int *ifindex) @@ -251,6 +275,7 @@ int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info) struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE]; struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN]; struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR]; + struct mptcp_pm_addr_entry local = { 0 }; struct mptcp_addr_info addr_r; struct mptcp_addr_info addr_l; struct mptcp_sock *msk; @@ -302,12 +327,24 @@ int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info) goto create_err; }

+ local.addr = addr_l; + err = mptcp_userspace_pm_append_new_local_addr(msk, &local); + if (err < 0) { + GENL_SET_ERR_MSG(info, "did not match address and id"); + goto create_err; + } + lock_sock(sk);

err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);

release_sock(sk);

+ spin_lock_bh(&msk->pm.lock); + if (err) + mptcp_userspace_pm_delete_local_addr(msk, &local); + spin_unlock_bh(&msk->pm.lock); + create_err: sock_put((struct sock *)msk); return err; @@ -420,7 +457,11 @@ int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info) ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r); if (ssk) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + struct mptcp_pm_addr_entry entry = { .addr = addr_l };

+ spin_lock_bh(&msk->pm.lock); + mptcp_userspace_pm_delete_local_addr(msk, &entry); + spin_unlock_bh(&msk->pm.lock); mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN); mptcp_close_ssk(sk, ssk, subflow); MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);

From: Geliang Tang geliang.tang@suse.com

Increase pm subflows counter on both server side and client side when userspace pm creates a new subflow, and decrease the counter when it closes a subflow.

Increase add_addr_signaled counter in mptcp_nl_cmd_announce() when the address is announced by userspace PM.

This modification is similar to how the in-kernel PM is updating the counter: when additional subflows are created/removed.

Fixes: 9ab4807c84a4 ("mptcp: netlink: Add MPTCP_PM_CMD_ANNOUNCE") Fixes: 702c2f646d42 ("mptcp: netlink: allow userspace-driven subflow establishment") Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/329 Cc: stable@vger.kernel.org Reviewed-by: Matthieu Baerts matthieu.baerts@tessares.net Signed-off-by: Geliang Tang geliang.tang@suse.com Signed-off-by: Mat Martineau martineau@kernel.org --- net/mptcp/pm.c | 23 +++++++++++++++++++---- net/mptcp/pm_userspace.c | 5 +++++ 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index 78c924506e83..76612bca275a 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -87,8 +87,15 @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk) unsigned int subflows_max; int ret = 0;

- if (mptcp_pm_is_userspace(msk)) - return mptcp_userspace_pm_active(msk); + if (mptcp_pm_is_userspace(msk)) { + if (mptcp_userspace_pm_active(msk)) { + spin_lock_bh(&pm->lock); + pm->subflows++; + spin_unlock_bh(&pm->lock); + return true; + } + return false; + }

subflows_max = mptcp_pm_get_subflows_max(msk);

@@ -181,8 +188,16 @@ void mptcp_pm_subflow_check_next(struct mptcp_sock *msk, const struct sock *ssk, struct mptcp_pm_data *pm = &msk->pm; bool update_subflows;

- update_subflows = (subflow->request_join || subflow->mp_join) && - mptcp_pm_is_kernel(msk); + update_subflows = subflow->request_join || subflow->mp_join; + if (mptcp_pm_is_userspace(msk)) { + if (update_subflows) { + spin_lock_bh(&pm->lock); + pm->subflows--; + spin_unlock_bh(&pm->lock); + } + return; + } + if (!READ_ONCE(pm->work_pending) && !update_subflows) return;

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c index 114548b09f47..b06aa58dfcf2 100644 --- a/net/mptcp/pm_userspace.c +++ b/net/mptcp/pm_userspace.c @@ -69,6 +69,7 @@ static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk, MPTCP_PM_MAX_ADDR_ID + 1, 1); list_add_tail_rcu(&e->list, &msk->pm.userspace_pm_local_addr_list); + msk->pm.local_addr_used++; ret = e->addr.id; } else if (match) { ret = entry->addr.id; @@ -96,6 +97,7 @@ static int mptcp_userspace_pm_delete_local_addr(struct mptcp_sock *msk, */ list_del_rcu(&entry->list); kfree(entry); + msk->pm.local_addr_used--; return 0; } } @@ -195,6 +197,7 @@ int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info) spin_lock_bh(&msk->pm.lock);

if (mptcp_pm_alloc_anno_list(msk, &addr_val)) { + msk->pm.add_addr_signaled++; mptcp_pm_announce_addr(msk, &addr_val.addr, false); mptcp_pm_nl_addr_send_ack(msk); } @@ -343,6 +346,8 @@ int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info) spin_lock_bh(&msk->pm.lock); if (err) mptcp_userspace_pm_delete_local_addr(msk, &local); + else + msk->pm.subflows++; spin_unlock_bh(&msk->pm.lock);

create_err: