1 // SPDX-License-Identifier: GPL-2.0
4 * Copyright (c) 2019, Intel Corporation.
6 #define pr_fmt(fmt) "MPTCP: " fmt
8 #include <linux/kernel.h>
10 #include <net/mptcp.h>
13 /* path manager command handlers */
15 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
16 const struct mptcp_addr_info *addr)
18 pr_debug("msk=%p, local_id=%d", msk, addr->id);
20 msk->pm.local = *addr;
21 WRITE_ONCE(msk->pm.addr_signal, true);
25 int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id)
30 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 remote_id)
35 /* path manager event handlers */
37 void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side)
39 struct mptcp_pm_data *pm = &msk->pm;
41 pr_debug("msk=%p, token=%u side=%d", msk, msk->token, server_side);
43 WRITE_ONCE(pm->server_side, server_side);
46 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
48 struct mptcp_pm_data *pm = &msk->pm;
51 pr_debug("msk=%p subflows=%d max=%d allow=%d", msk, pm->subflows,
52 pm->subflows_max, READ_ONCE(pm->accept_subflow));
54 /* try to avoid acquiring the lock below */
55 if (!READ_ONCE(pm->accept_subflow))
58 spin_lock_bh(&pm->lock);
59 ret = pm->subflows < pm->subflows_max;
60 if (ret && ++pm->subflows == pm->subflows_max)
61 WRITE_ONCE(pm->accept_subflow, false);
62 spin_unlock_bh(&pm->lock);
67 /* return true if the new status bit is currently cleared, that is, this event
68 * can be server, eventually by an already scheduled work
70 static bool mptcp_pm_schedule_work(struct mptcp_sock *msk,
71 enum mptcp_pm_status new_status)
73 pr_debug("msk=%p status=%x new=%lx", msk, msk->pm.status,
75 if (msk->pm.status & BIT(new_status))
78 msk->pm.status |= BIT(new_status);
79 if (schedule_work(&msk->work))
80 sock_hold((struct sock *)msk);
84 void mptcp_pm_fully_established(struct mptcp_sock *msk)
86 struct mptcp_pm_data *pm = &msk->pm;
88 pr_debug("msk=%p", msk);
90 /* try to avoid acquiring the lock below */
91 if (!READ_ONCE(pm->work_pending))
94 spin_lock_bh(&pm->lock);
96 if (READ_ONCE(pm->work_pending))
97 mptcp_pm_schedule_work(msk, MPTCP_PM_ESTABLISHED);
99 spin_unlock_bh(&pm->lock);
102 void mptcp_pm_connection_closed(struct mptcp_sock *msk)
104 pr_debug("msk=%p", msk);
107 void mptcp_pm_subflow_established(struct mptcp_sock *msk,
108 struct mptcp_subflow_context *subflow)
110 struct mptcp_pm_data *pm = &msk->pm;
112 pr_debug("msk=%p", msk);
114 if (!READ_ONCE(pm->work_pending))
117 spin_lock_bh(&pm->lock);
119 if (READ_ONCE(pm->work_pending))
120 mptcp_pm_schedule_work(msk, MPTCP_PM_SUBFLOW_ESTABLISHED);
122 spin_unlock_bh(&pm->lock);
125 void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id)
127 pr_debug("msk=%p", msk);
130 void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
131 const struct mptcp_addr_info *addr)
133 struct mptcp_pm_data *pm = &msk->pm;
135 pr_debug("msk=%p remote_id=%d accept=%d", msk, addr->id,
136 READ_ONCE(pm->accept_addr));
138 /* avoid acquiring the lock if there is no room for fouther addresses */
139 if (!READ_ONCE(pm->accept_addr))
142 spin_lock_bh(&pm->lock);
144 /* be sure there is something to signal re-checking under PM lock */
145 if (READ_ONCE(pm->accept_addr) &&
146 mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED))
149 spin_unlock_bh(&pm->lock);
152 /* path manager helpers */
154 bool mptcp_pm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
155 struct mptcp_addr_info *saddr)
159 spin_lock_bh(&msk->pm.lock);
161 /* double check after the lock is acquired */
162 if (!mptcp_pm_should_signal(msk))
165 if (remaining < mptcp_add_addr_len(msk->pm.local.family))
168 *saddr = msk->pm.local;
169 WRITE_ONCE(msk->pm.addr_signal, false);
173 spin_unlock_bh(&msk->pm.lock);
177 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
179 return mptcp_pm_nl_get_local_id(msk, skc);
182 void mptcp_pm_data_init(struct mptcp_sock *msk)
184 msk->pm.add_addr_signaled = 0;
185 msk->pm.add_addr_accepted = 0;
186 msk->pm.local_addr_used = 0;
187 msk->pm.subflows = 0;
188 WRITE_ONCE(msk->pm.work_pending, false);
189 WRITE_ONCE(msk->pm.addr_signal, false);
190 WRITE_ONCE(msk->pm.accept_addr, false);
191 WRITE_ONCE(msk->pm.accept_subflow, false);
194 spin_lock_init(&msk->pm.lock);
196 mptcp_pm_nl_data_init(msk);
199 void __init mptcp_pm_init(void)