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,
19 pr_debug("msk=%p, local_id=%d", msk, addr->id);
21 msk->pm.local = *addr;
22 WRITE_ONCE(msk->pm.add_addr_echo, echo);
23 WRITE_ONCE(msk->pm.add_addr_signal, true);
27 int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id)
29 pr_debug("msk=%p, local_id=%d", msk, local_id);
31 msk->pm.rm_id = local_id;
32 WRITE_ONCE(msk->pm.rm_addr_signal, true);
36 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 local_id)
38 pr_debug("msk=%p, local_id=%d", msk, local_id);
40 spin_lock_bh(&msk->pm.lock);
41 mptcp_pm_nl_rm_subflow_received(msk, local_id);
42 spin_unlock_bh(&msk->pm.lock);
46 /* path manager event handlers */
48 void mptcp_pm_new_connection(struct mptcp_sock *msk, int server_side)
50 struct mptcp_pm_data *pm = &msk->pm;
52 pr_debug("msk=%p, token=%u side=%d", msk, msk->token, server_side);
54 WRITE_ONCE(pm->server_side, server_side);
57 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
59 struct mptcp_pm_data *pm = &msk->pm;
62 pr_debug("msk=%p subflows=%d max=%d allow=%d", msk, pm->subflows,
63 pm->subflows_max, READ_ONCE(pm->accept_subflow));
65 /* try to avoid acquiring the lock below */
66 if (!READ_ONCE(pm->accept_subflow))
69 spin_lock_bh(&pm->lock);
70 if (READ_ONCE(pm->accept_subflow)) {
71 ret = pm->subflows < pm->subflows_max;
72 if (ret && ++pm->subflows == pm->subflows_max)
73 WRITE_ONCE(pm->accept_subflow, false);
75 spin_unlock_bh(&pm->lock);
80 /* return true if the new status bit is currently cleared, that is, this event
81 * can be server, eventually by an already scheduled work
83 static bool mptcp_pm_schedule_work(struct mptcp_sock *msk,
84 enum mptcp_pm_status new_status)
86 pr_debug("msk=%p status=%x new=%lx", msk, msk->pm.status,
88 if (msk->pm.status & BIT(new_status))
91 msk->pm.status |= BIT(new_status);
92 if (schedule_work(&msk->work))
93 sock_hold((struct sock *)msk);
97 void mptcp_pm_fully_established(struct mptcp_sock *msk)
99 struct mptcp_pm_data *pm = &msk->pm;
101 pr_debug("msk=%p", msk);
103 /* try to avoid acquiring the lock below */
104 if (!READ_ONCE(pm->work_pending))
107 spin_lock_bh(&pm->lock);
109 if (READ_ONCE(pm->work_pending))
110 mptcp_pm_schedule_work(msk, MPTCP_PM_ESTABLISHED);
112 spin_unlock_bh(&pm->lock);
115 void mptcp_pm_connection_closed(struct mptcp_sock *msk)
117 pr_debug("msk=%p", msk);
120 void mptcp_pm_subflow_established(struct mptcp_sock *msk,
121 struct mptcp_subflow_context *subflow)
123 struct mptcp_pm_data *pm = &msk->pm;
125 pr_debug("msk=%p", msk);
127 if (!READ_ONCE(pm->work_pending))
130 spin_lock_bh(&pm->lock);
132 if (READ_ONCE(pm->work_pending))
133 mptcp_pm_schedule_work(msk, MPTCP_PM_SUBFLOW_ESTABLISHED);
135 spin_unlock_bh(&pm->lock);
138 void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id)
140 pr_debug("msk=%p", msk);
143 void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
144 const struct mptcp_addr_info *addr)
146 struct mptcp_pm_data *pm = &msk->pm;
148 pr_debug("msk=%p remote_id=%d accept=%d", msk, addr->id,
149 READ_ONCE(pm->accept_addr));
151 spin_lock_bh(&pm->lock);
153 if (!READ_ONCE(pm->accept_addr))
154 mptcp_pm_announce_addr(msk, addr, true);
155 else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED))
158 spin_unlock_bh(&pm->lock);
161 void mptcp_pm_rm_addr_received(struct mptcp_sock *msk, u8 rm_id)
163 struct mptcp_pm_data *pm = &msk->pm;
165 pr_debug("msk=%p remote_id=%d", msk, rm_id);
167 spin_lock_bh(&pm->lock);
168 mptcp_pm_schedule_work(msk, MPTCP_PM_RM_ADDR_RECEIVED);
170 spin_unlock_bh(&pm->lock);
173 /* path manager helpers */
175 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
176 struct mptcp_addr_info *saddr, bool *echo)
180 spin_lock_bh(&msk->pm.lock);
182 /* double check after the lock is acquired */
183 if (!mptcp_pm_should_add_signal(msk))
186 if (remaining < mptcp_add_addr_len(msk->pm.local.family))
189 *saddr = msk->pm.local;
190 *echo = READ_ONCE(msk->pm.add_addr_echo);
191 WRITE_ONCE(msk->pm.add_addr_signal, false);
195 spin_unlock_bh(&msk->pm.lock);
199 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
204 spin_lock_bh(&msk->pm.lock);
206 /* double check after the lock is acquired */
207 if (!mptcp_pm_should_rm_signal(msk))
210 if (remaining < TCPOLEN_MPTCP_RM_ADDR_BASE)
213 *rm_id = msk->pm.rm_id;
214 WRITE_ONCE(msk->pm.rm_addr_signal, false);
218 spin_unlock_bh(&msk->pm.lock);
222 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
224 return mptcp_pm_nl_get_local_id(msk, skc);
227 void mptcp_pm_data_init(struct mptcp_sock *msk)
229 msk->pm.add_addr_signaled = 0;
230 msk->pm.add_addr_accepted = 0;
231 msk->pm.local_addr_used = 0;
232 msk->pm.subflows = 0;
234 WRITE_ONCE(msk->pm.work_pending, false);
235 WRITE_ONCE(msk->pm.add_addr_signal, false);
236 WRITE_ONCE(msk->pm.rm_addr_signal, false);
237 WRITE_ONCE(msk->pm.accept_addr, false);
238 WRITE_ONCE(msk->pm.accept_subflow, false);
239 WRITE_ONCE(msk->pm.add_addr_echo, false);
242 spin_lock_init(&msk->pm.lock);
243 INIT_LIST_HEAD(&msk->pm.anno_list);
245 mptcp_pm_nl_data_init(msk);
248 void __init mptcp_pm_init(void)