A few variables linked to the in-kernel Path-Manager are confusing, and it would help current and future developers, to clarify them.
One of them is 'subflows_max', which in fact represents the limit of extra subflows: the limit set via 'ip mptcp limit subflows X' for example. It is not linked to the maximum number of created / possible subflows.
While at it, add an additional name for the corresponding variable in MPTCP INFO: mptcpi_limit_extra_subflows. Not to break the current uAPI, the new name is added as a 'define' pointing to the former name. This will then also help userspace devs.
No functional changes intended.
Reviewed-by: Geliang Tang geliang@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- include/uapi/linux/mptcp.h | 1 + net/mptcp/pm.c | 12 ++++++------ net/mptcp/pm_kernel.c | 48 ++++++++++++++++++++++++---------------------- net/mptcp/protocol.h | 6 +++--- net/mptcp/sockopt.c | 4 ++-- 5 files changed, 37 insertions(+), 34 deletions(-)
diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h index f807c8dba56e7eb278fce0ad3184de3d0e24399b..314200c61f150da445ff87debb154bfd98f324fc 100644 --- a/include/uapi/linux/mptcp.h +++ b/include/uapi/linux/mptcp.h @@ -46,6 +46,7 @@ struct mptcp_info { __u8 mptcpi_add_addr_signal; __u8 mptcpi_add_addr_accepted; __u8 mptcpi_subflows_max; + #define mptcpi_limit_extra_subflows mptcpi_subflows_max __u8 mptcpi_add_addr_signal_max; __u8 mptcpi_add_addr_accepted_max; __u32 mptcpi_flags; diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c index 332e96bdadc0b936704188e5c9666cba97817b16..502f6c235e06c3f6fdca9dcf3a1d7b8e97fb9df6 100644 --- a/net/mptcp/pm.c +++ b/net/mptcp/pm.c @@ -483,7 +483,7 @@ void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk) { struct mptcp_pm_data *pm = &msk->pm; - unsigned int subflows_max; + unsigned int limit_extra_subflows; int ret = 0;
if (mptcp_pm_is_userspace(msk)) { @@ -496,10 +496,10 @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk) return false; }
- subflows_max = mptcp_pm_get_subflows_max(msk); + limit_extra_subflows = mptcp_pm_get_limit_extra_subflows(msk);
pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk, - pm->extra_subflows, subflows_max, + pm->extra_subflows, limit_extra_subflows, READ_ONCE(pm->accept_subflow));
/* try to avoid acquiring the lock below */ @@ -508,8 +508,8 @@ bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
spin_lock_bh(&pm->lock); if (READ_ONCE(pm->accept_subflow)) { - ret = pm->extra_subflows < subflows_max; - if (ret && ++pm->extra_subflows == subflows_max) + ret = pm->extra_subflows < limit_extra_subflows; + if (ret && ++pm->extra_subflows == limit_extra_subflows) WRITE_ONCE(pm->accept_subflow, false); } spin_unlock_bh(&pm->lock); @@ -1029,7 +1029,7 @@ void mptcp_pm_data_reset(struct mptcp_sock *msk) WRITE_ONCE(pm->pm_type, pm_type);
if (pm_type == MPTCP_PM_TYPE_KERNEL) { - bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk); + bool subflows_allowed = !!mptcp_pm_get_limit_extra_subflows(msk);
/* pm->work_pending must be only be set to 'true' when * pm->pm_type is set to MPTCP_PM_TYPE_KERNEL diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c index 20bee6fc06259a0211782c94c1693ffe79dae1b6..db0d254d0e6b903fd8b920eb4cda628a811f7d58 100644 --- a/net/mptcp/pm_kernel.c +++ b/net/mptcp/pm_kernel.c @@ -23,7 +23,7 @@ struct pm_nl_pernet { unsigned int add_addr_signal_max; unsigned int add_addr_accept_max; unsigned int local_addr_max; - unsigned int subflows_max; + unsigned int limit_extra_subflows; unsigned int next_id; DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1); }; @@ -62,13 +62,13 @@ unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk) } EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_accept_max);
-unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk) +unsigned int mptcp_pm_get_limit_extra_subflows(const struct mptcp_sock *msk) { struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
- return READ_ONCE(pernet->subflows_max); + return READ_ONCE(pernet->limit_extra_subflows); } -EXPORT_SYMBOL_GPL(mptcp_pm_get_subflows_max); +EXPORT_SYMBOL_GPL(mptcp_pm_get_limit_extra_subflows);
unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk) { @@ -190,10 +190,10 @@ fill_remote_addresses_fullmesh(struct mptcp_sock *msk, DECLARE_BITMAP(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1); struct sock *sk = (struct sock *)msk, *ssk; struct mptcp_subflow_context *subflow; - unsigned int subflows_max; + unsigned int limit_extra_subflows; int i = 0;
- subflows_max = mptcp_pm_get_subflows_max(msk); + limit_extra_subflows = mptcp_pm_get_limit_extra_subflows(msk);
/* Forbid creation of new subflows matching existing ones, possibly * already created by incoming ADD_ADDR @@ -221,7 +221,7 @@ fill_remote_addresses_fullmesh(struct mptcp_sock *msk, msk->pm.extra_subflows++; i++;
- if (msk->pm.extra_subflows >= subflows_max) + if (msk->pm.extra_subflows >= limit_extra_subflows) break; }
@@ -274,18 +274,18 @@ __lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info) static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk) { struct sock *sk = (struct sock *)msk; + unsigned int limit_extra_subflows; unsigned int add_addr_signal_max; bool signal_and_subflow = false; unsigned int local_addr_max; struct pm_nl_pernet *pernet; struct mptcp_pm_local local; - unsigned int subflows_max;
pernet = pm_nl_get_pernet(sock_net(sk));
add_addr_signal_max = mptcp_pm_get_add_addr_signal_max(msk); local_addr_max = mptcp_pm_get_local_addr_max(msk); - subflows_max = mptcp_pm_get_subflows_max(msk); + limit_extra_subflows = mptcp_pm_get_limit_extra_subflows(msk);
/* do lazy endpoint usage accounting for the MPC subflows */ if (unlikely(!(msk->pm.status & BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED))) && msk->first) { @@ -313,7 +313,7 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk) pr_debug("local %d:%d signal %d:%d subflows %d:%d\n", msk->pm.local_addr_used, local_addr_max, msk->pm.add_addr_signaled, add_addr_signal_max, - msk->pm.extra_subflows, subflows_max); + msk->pm.extra_subflows, limit_extra_subflows);
/* check first for announce */ if (msk->pm.add_addr_signaled < add_addr_signal_max) { @@ -353,7 +353,7 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk) subflow: /* check if should create a new subflow */ while (msk->pm.local_addr_used < local_addr_max && - msk->pm.extra_subflows < subflows_max) { + msk->pm.extra_subflows < limit_extra_subflows) { struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX]; bool fullmesh; int i, nr; @@ -402,14 +402,15 @@ fill_local_addresses_vec_fullmesh(struct mptcp_sock *msk, bool c_flag_case) { struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); - unsigned int subflows_max = mptcp_pm_get_subflows_max(msk); struct sock *sk = (struct sock *)msk; struct mptcp_pm_addr_entry *entry; + unsigned int limit_extra_subflows; struct mptcp_addr_info mpc_addr; struct mptcp_pm_local *local; int i = 0;
mptcp_local_address((struct sock_common *)msk, &mpc_addr); + limit_extra_subflows = mptcp_pm_get_limit_extra_subflows(msk);
rcu_read_lock(); list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) { @@ -444,7 +445,7 @@ fill_local_addresses_vec_fullmesh(struct mptcp_sock *msk, msk->pm.extra_subflows++; i++;
- if (msk->pm.extra_subflows >= subflows_max) + if (msk->pm.extra_subflows >= limit_extra_subflows) break; } rcu_read_unlock(); @@ -459,13 +460,14 @@ fill_local_addresses_vec_c_flag(struct mptcp_sock *msk, { unsigned int local_addr_max = mptcp_pm_get_local_addr_max(msk); struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); - unsigned int subflows_max = mptcp_pm_get_subflows_max(msk); struct sock *sk = (struct sock *)msk; + unsigned int limit_extra_subflows; struct mptcp_addr_info mpc_addr; struct mptcp_pm_local *local; int i = 0;
mptcp_local_address((struct sock_common *)msk, &mpc_addr); + limit_extra_subflows = mptcp_pm_get_limit_extra_subflows(msk);
while (msk->pm.local_addr_used < local_addr_max) { local = &locals[i]; @@ -486,7 +488,7 @@ fill_local_addresses_vec_c_flag(struct mptcp_sock *msk, msk->pm.extra_subflows++; i++;
- if (msk->pm.extra_subflows >= subflows_max) + if (msk->pm.extra_subflows >= limit_extra_subflows) break; }
@@ -544,14 +546,14 @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk) { struct mptcp_pm_local locals[MPTCP_PM_ADDR_MAX]; struct sock *sk = (struct sock *)msk; + unsigned int limit_extra_subflows; unsigned int add_addr_accept_max; struct mptcp_addr_info remote; - unsigned int subflows_max; bool sf_created = false; int i, nr;
add_addr_accept_max = mptcp_pm_get_add_addr_accept_max(msk); - subflows_max = mptcp_pm_get_subflows_max(msk); + limit_extra_subflows = mptcp_pm_get_limit_extra_subflows(msk);
pr_debug("accepted %d:%d remote family %d\n", msk->pm.add_addr_accepted, add_addr_accept_max, @@ -586,7 +588,7 @@ static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk) if (remote.id) msk->pm.add_addr_accepted++; if (msk->pm.add_addr_accepted >= add_addr_accept_max || - msk->pm.extra_subflows >= subflows_max) + msk->pm.extra_subflows >= limit_extra_subflows) WRITE_ONCE(msk->pm.accept_addr, false); } } @@ -1285,13 +1287,13 @@ int mptcp_pm_nl_set_limits_doit(struct sk_buff *skb, struct genl_info *info) if (ret) goto unlock;
- subflows = pernet->subflows_max; + subflows = pernet->limit_extra_subflows; ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows); if (ret) goto unlock;
WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs); - WRITE_ONCE(pernet->subflows_max, subflows); + WRITE_ONCE(pernet->limit_extra_subflows, subflows);
unlock: spin_unlock_bh(&pernet->lock); @@ -1318,7 +1320,7 @@ int mptcp_pm_nl_get_limits_doit(struct sk_buff *skb, struct genl_info *info) goto fail;
if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS, - READ_ONCE(pernet->subflows_max))) + READ_ONCE(pernet->limit_extra_subflows))) goto fail;
genlmsg_end(msg, reply); @@ -1427,7 +1429,7 @@ bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk) { struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
- if (msk->pm.extra_subflows == mptcp_pm_get_subflows_max(msk) || + if (msk->pm.extra_subflows == mptcp_pm_get_limit_extra_subflows(msk) || (find_next_and_bit(pernet->id_bitmap, msk->pm.id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1, 0) == MPTCP_PM_MAX_ADDR_ID + 1)) { WRITE_ONCE(msk->pm.work_pending, false); @@ -1462,7 +1464,7 @@ static int __net_init pm_nl_init_net(struct net *net) INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
/* Cit. 2 subflows ought to be enough for anybody. */ - pernet->subflows_max = 2; + pernet->limit_extra_subflows = 2; pernet->next_id = 1; pernet->stale_loss_cnt = 4; spin_lock_init(&pernet->lock); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index ca68f9a7580149e43139ec6cc61a1e0b966e7a22..4c777f87b0497ed623f0d51bf1f87cfa011cf0eb 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -1182,13 +1182,13 @@ void mptcp_pm_worker(struct mptcp_sock *msk); void __mptcp_pm_kernel_worker(struct mptcp_sock *msk); unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk); unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk); -unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk); +unsigned int mptcp_pm_get_limit_extra_subflows(const struct mptcp_sock *msk); unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk);
/* called under PM lock */ static inline void __mptcp_pm_close_subflow(struct mptcp_sock *msk) { - if (--msk->pm.extra_subflows < mptcp_pm_get_subflows_max(msk)) + if (--msk->pm.extra_subflows < mptcp_pm_get_limit_extra_subflows(msk)) WRITE_ONCE(msk->pm.accept_subflow, true); }
@@ -1204,7 +1204,7 @@ static inline bool mptcp_pm_add_addr_c_flag_case(struct mptcp_sock *msk) return READ_ONCE(msk->pm.remote_deny_join_id0) && msk->pm.local_addr_used == 0 && mptcp_pm_get_add_addr_accept_max(msk) == 0 && - msk->pm.extra_subflows < mptcp_pm_get_subflows_max(msk); + msk->pm.extra_subflows < mptcp_pm_get_limit_extra_subflows(msk); }
void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk); diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index 17966da80239d731de925f3e4211b3ee00f802e4..4e82bcfcd34e3a1dffb05799cf181ee2940e75d7 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -972,8 +972,8 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info)
/* The following limits only make sense for the in-kernel PM */ if (mptcp_pm_is_kernel(msk)) { - info->mptcpi_subflows_max = - mptcp_pm_get_subflows_max(msk); + info->mptcpi_limit_extra_subflows = + mptcp_pm_get_limit_extra_subflows(msk); info->mptcpi_add_addr_signal_max = mptcp_pm_get_add_addr_signal_max(msk); info->mptcpi_add_addr_accepted_max =