diff options
Diffstat (limited to 'net/mptcp/pm.c')
| -rw-r--r-- | net/mptcp/pm.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c new file mode 100644 index 000000000..e19e1525e --- /dev/null +++ b/net/mptcp/pm.c @@ -0,0 +1,252 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Multipath TCP + * + * Copyright (c) 2019, Intel Corporation. + */ +#define pr_fmt(fmt) "MPTCP: " fmt + +#include <linux/kernel.h> +#include <net/tcp.h> +#include <net/mptcp.h> +#include "protocol.h" + +/* path manager command handlers */ + +int mptcp_pm_announce_addr(struct mptcp_sock *msk, + const struct mptcp_addr_info *addr, + bool echo) +{ + pr_debug("msk=%p, local_id=%d", msk, addr->id); + + msk->pm.local = *addr; + WRITE_ONCE(msk->pm.add_addr_echo, echo); + WRITE_ONCE(msk->pm.add_addr_signal, true); + return 0; +} + +int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id) +{ + pr_debug("msk=%p, local_id=%d", msk, local_id); + + msk->pm.rm_id = local_id; + WRITE_ONCE(msk->pm.rm_addr_signal, true); + return 0; +} + +int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 local_id) +{ + pr_debug("msk=%p, local_id=%d", msk, local_id); + + spin_lock_bh(&msk->pm.lock); + mptcp_pm_nl_rm_subflow_received(msk, local_id); + spin_unlock_bh(&msk->pm.lock); + return 0; +} + +/* path manager event handlers */ + +void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side) +{ + struct mptcp_pm_data *pm = &msk->pm; + + pr_debug("msk=%p, token=%u side=%d", msk, msk->token, server_side); + + WRITE_ONCE(pm->server_side, server_side); +} + +bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk) +{ + struct mptcp_pm_data *pm = &msk->pm; + int ret = 0; + + pr_debug("msk=%p subflows=%d max=%d allow=%d", msk, pm->subflows, + pm->subflows_max, READ_ONCE(pm->accept_subflow)); + + /* try to avoid acquiring the lock below */ + if (!READ_ONCE(pm->accept_subflow)) + return false; + + spin_lock_bh(&pm->lock); + if (READ_ONCE(pm->accept_subflow)) { + ret = pm->subflows < pm->subflows_max; + if (ret && ++pm->subflows == pm->subflows_max) + WRITE_ONCE(pm->accept_subflow, false); + } + spin_unlock_bh(&pm->lock); + + return ret; +} + +/* return true if the new status bit is currently cleared, that is, this event + * can be server, eventually by an already scheduled work + */ +static bool mptcp_pm_schedule_work(struct mptcp_sock *msk, + enum mptcp_pm_status new_status) +{ + pr_debug("msk=%p status=%x new=%lx", msk, msk->pm.status, + BIT(new_status)); + if (msk->pm.status & BIT(new_status)) + return false; + + msk->pm.status |= BIT(new_status); + if (schedule_work(&msk->work)) + sock_hold((struct sock *)msk); + return true; +} + +void mptcp_pm_fully_established(struct mptcp_sock *msk) +{ + struct mptcp_pm_data *pm = &msk->pm; + + pr_debug("msk=%p", msk); + + /* try to avoid acquiring the lock below */ + if (!READ_ONCE(pm->work_pending)) + return; + + spin_lock_bh(&pm->lock); + + if (READ_ONCE(pm->work_pending)) + mptcp_pm_schedule_work(msk, MPTCP_PM_ESTABLISHED); + + spin_unlock_bh(&pm->lock); +} + +void mptcp_pm_connection_closed(struct mptcp_sock *msk) +{ + pr_debug("msk=%p", msk); +} + +void mptcp_pm_subflow_established(struct mptcp_sock *msk, + struct mptcp_subflow_context *subflow) +{ + struct mptcp_pm_data *pm = &msk->pm; + + pr_debug("msk=%p", msk); + + if (!READ_ONCE(pm->work_pending)) + return; + + spin_lock_bh(&pm->lock); + + if (READ_ONCE(pm->work_pending)) + mptcp_pm_schedule_work(msk, MPTCP_PM_SUBFLOW_ESTABLISHED); + + spin_unlock_bh(&pm->lock); +} + +void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id) +{ + pr_debug("msk=%p", msk); +} + +void mptcp_pm_add_addr_received(struct mptcp_sock *msk, + const struct mptcp_addr_info *addr) +{ + struct mptcp_pm_data *pm = &msk->pm; + + pr_debug("msk=%p remote_id=%d accept=%d", msk, addr->id, + READ_ONCE(pm->accept_addr)); + + spin_lock_bh(&pm->lock); + + if (!READ_ONCE(pm->accept_addr)) + mptcp_pm_announce_addr(msk, addr, true); + else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) + pm->remote = *addr; + + spin_unlock_bh(&pm->lock); +} + +void mptcp_pm_rm_addr_received(struct mptcp_sock *msk, u8 rm_id) +{ + struct mptcp_pm_data *pm = &msk->pm; + + pr_debug("msk=%p remote_id=%d", msk, rm_id); + + spin_lock_bh(&pm->lock); + mptcp_pm_schedule_work(msk, MPTCP_PM_RM_ADDR_RECEIVED); + pm->rm_id = rm_id; + spin_unlock_bh(&pm->lock); +} + +/* path manager helpers */ + +bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining, + struct mptcp_addr_info *saddr, bool *echo) +{ + int ret = false; + + spin_lock_bh(&msk->pm.lock); + + /* double check after the lock is acquired */ + if (!mptcp_pm_should_add_signal(msk)) + goto out_unlock; + + *echo = READ_ONCE(msk->pm.add_addr_echo); + + if (remaining < mptcp_add_addr_len(msk->pm.local.family, *echo)) + goto out_unlock; + + *saddr = msk->pm.local; + WRITE_ONCE(msk->pm.add_addr_signal, false); + ret = true; + +out_unlock: + spin_unlock_bh(&msk->pm.lock); + return ret; +} + +bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining, + u8 *rm_id) +{ + int ret = false; + + spin_lock_bh(&msk->pm.lock); + + /* double check after the lock is acquired */ + if (!mptcp_pm_should_rm_signal(msk)) + goto out_unlock; + + if (remaining < TCPOLEN_MPTCP_RM_ADDR_BASE) + goto out_unlock; + + *rm_id = msk->pm.rm_id; + WRITE_ONCE(msk->pm.rm_addr_signal, false); + ret = true; + +out_unlock: + spin_unlock_bh(&msk->pm.lock); + return ret; +} + +int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc) +{ + return mptcp_pm_nl_get_local_id(msk, skc); +} + +void mptcp_pm_data_init(struct mptcp_sock *msk) +{ + msk->pm.add_addr_signaled = 0; + msk->pm.add_addr_accepted = 0; + msk->pm.local_addr_used = 0; + msk->pm.subflows = 0; + msk->pm.rm_id = 0; + WRITE_ONCE(msk->pm.work_pending, false); + WRITE_ONCE(msk->pm.add_addr_signal, false); + WRITE_ONCE(msk->pm.rm_addr_signal, false); + WRITE_ONCE(msk->pm.accept_addr, false); + WRITE_ONCE(msk->pm.accept_subflow, false); + WRITE_ONCE(msk->pm.add_addr_echo, false); + msk->pm.status = 0; + + spin_lock_init(&msk->pm.lock); + INIT_LIST_HEAD(&msk->pm.anno_list); + + mptcp_pm_nl_data_init(msk); +} + +void __init mptcp_pm_init(void) +{ + mptcp_pm_nl_init(); +} |