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.
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
include/uapi/linux/mptcp.h | 1 +
net/mptcp/pm.c | 10 +++++-----
net/mptcp/pm_kernel.c | 50 ++++++++++++++++++++++++----------------------
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 2e0b7509b8a91cba14f656480f425e0f7241890e..ea40f31f17ba0d6c82db250d17f5a051ce6fabfa 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, READ_ONCE(pm->accept_subflow));
+ limit_extra_subflows, READ_ONCE(pm->accept_subflow));
/* try to avoid acquiring the lock below */
if (!READ_ONCE(pm->accept_subflow))
@@ -507,8 +507,8 @@ 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);
diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c
index 6439f877f334083d86c85d3c19caebba8da7902c..e61d417da2154809ad83da5a1b8eede1216a2b5a 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;
}
@@ -270,18 +270,18 @@ __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) {
@@ -309,7 +309,7 @@ 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) {
@@ -349,7 +349,7 @@ 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;
@@ -398,14 +398,15 @@ 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) {
@@ -431,7 +432,7 @@ 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();
@@ -446,13 +447,14 @@ 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];
@@ -473,7 +475,7 @@ 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;
}
@@ -531,14 +533,14 @@ 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,
@@ -573,7 +575,7 @@ 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);
}
}
@@ -1273,13 +1275,13 @@ 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);
@@ -1306,7 +1308,7 @@ 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);
@@ -1415,7 +1417,7 @@ 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);
@@ -1450,7 +1452,7 @@ 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);
@@ -1486,7 +1488,7 @@ static struct pernet_operations mptcp_pm_pernet_ops = {
static void mptcp_pm_kernel_init(struct mptcp_sock *msk)
{
- bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
+ bool subflows_allowed = !!mptcp_pm_get_limit_extra_subflows(msk);
struct mptcp_pm_data *pm = &msk->pm;
/* pm->work_pending must be only be set to 'true' when
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 33f7bf9a8c1344a01432c18d183a5d1b2d1f2c9e..acfe46e530cd75b14b33d9f4940b90fbf2867517 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -1179,13 +1179,13 @@ 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);
}
@@ -1201,7 +1201,7 @@ 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 =
--
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