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 u8 add_addr = READ_ONCE(msk->pm.addr_signal);
21 pr_debug("msk=%p, local_id=%d", msk, addr->id);
23 lockdep_assert_held(&msk->pm.lock);
26 pr_warn("addr_signal error, add_addr=%d", add_addr);
30 msk->pm.local = *addr;
31 add_addr |= BIT(MPTCP_ADD_ADDR_SIGNAL);
33 add_addr |= BIT(MPTCP_ADD_ADDR_ECHO);
34 if (addr->family == AF_INET6)
35 add_addr |= BIT(MPTCP_ADD_ADDR_IPV6);
37 add_addr |= BIT(MPTCP_ADD_ADDR_PORT);
38 WRITE_ONCE(msk->pm.addr_signal, add_addr);
42 int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id)
44 u8 rm_addr = READ_ONCE(msk->pm.addr_signal);
46 pr_debug("msk=%p, local_id=%d", msk, local_id);
49 pr_warn("addr_signal error, rm_addr=%d", rm_addr);
53 msk->pm.rm_id = local_id;
54 rm_addr |= BIT(MPTCP_RM_ADDR_SIGNAL);
55 WRITE_ONCE(msk->pm.addr_signal, rm_addr);
59 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 local_id)
61 pr_debug("msk=%p, local_id=%d", msk, local_id);
63 spin_lock_bh(&msk->pm.lock);
64 mptcp_pm_nl_rm_subflow_received(msk, local_id);
65 spin_unlock_bh(&msk->pm.lock);
69 /* path manager event handlers */
71 void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side)
73 struct mptcp_pm_data *pm = &msk->pm;
75 pr_debug("msk=%p, token=%u side=%d", msk, msk->token, server_side);
77 WRITE_ONCE(pm->server_side, server_side);
78 mptcp_event(MPTCP_EVENT_CREATED, msk, ssk, GFP_ATOMIC);
81 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
83 struct mptcp_pm_data *pm = &msk->pm;
84 unsigned int subflows_max;
87 subflows_max = mptcp_pm_get_subflows_max(msk);
89 pr_debug("msk=%p subflows=%d max=%d allow=%d", msk, pm->subflows,
90 subflows_max, READ_ONCE(pm->accept_subflow));
92 /* try to avoid acquiring the lock below */
93 if (!READ_ONCE(pm->accept_subflow))
96 spin_lock_bh(&pm->lock);
97 if (READ_ONCE(pm->accept_subflow)) {
98 ret = pm->subflows < subflows_max;
99 if (ret && ++pm->subflows == subflows_max)
100 WRITE_ONCE(pm->accept_subflow, false);
102 spin_unlock_bh(&pm->lock);
107 /* return true if the new status bit is currently cleared, that is, this event
108 * can be server, eventually by an already scheduled work
110 static bool mptcp_pm_schedule_work(struct mptcp_sock *msk,
111 enum mptcp_pm_status new_status)
113 pr_debug("msk=%p status=%x new=%lx", msk, msk->pm.status,
115 if (msk->pm.status & BIT(new_status))
118 msk->pm.status |= BIT(new_status);
119 mptcp_schedule_work((struct sock *)msk);
123 void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk, gfp_t gfp)
125 struct mptcp_pm_data *pm = &msk->pm;
126 bool announce = false;
128 pr_debug("msk=%p", msk);
130 spin_lock_bh(&pm->lock);
132 /* mptcp_pm_fully_established() can be invoked by multiple
133 * racing paths - accept() and check_fully_established()
134 * be sure to serve this event only once.
136 if (READ_ONCE(pm->work_pending) &&
137 !(msk->pm.status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)))
138 mptcp_pm_schedule_work(msk, MPTCP_PM_ESTABLISHED);
140 if ((msk->pm.status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)) == 0)
143 msk->pm.status |= BIT(MPTCP_PM_ALREADY_ESTABLISHED);
144 spin_unlock_bh(&pm->lock);
147 mptcp_event(MPTCP_EVENT_ESTABLISHED, msk, ssk, gfp);
150 void mptcp_pm_connection_closed(struct mptcp_sock *msk)
152 pr_debug("msk=%p", msk);
155 void mptcp_pm_subflow_established(struct mptcp_sock *msk,
156 struct mptcp_subflow_context *subflow)
158 struct mptcp_pm_data *pm = &msk->pm;
160 pr_debug("msk=%p", msk);
162 if (!READ_ONCE(pm->work_pending))
165 spin_lock_bh(&pm->lock);
167 if (READ_ONCE(pm->work_pending))
168 mptcp_pm_schedule_work(msk, MPTCP_PM_SUBFLOW_ESTABLISHED);
170 spin_unlock_bh(&pm->lock);
173 void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id)
175 pr_debug("msk=%p", msk);
178 void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
179 const struct mptcp_addr_info *addr)
181 struct mptcp_pm_data *pm = &msk->pm;
183 pr_debug("msk=%p remote_id=%d accept=%d", msk, addr->id,
184 READ_ONCE(pm->accept_addr));
186 mptcp_event_addr_announced(msk, addr);
188 spin_lock_bh(&pm->lock);
190 if (!READ_ONCE(pm->accept_addr)) {
191 mptcp_pm_announce_addr(msk, addr, true, addr->port);
192 mptcp_pm_add_addr_send_ack(msk);
193 } else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) {
197 spin_unlock_bh(&pm->lock);
200 void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk)
202 if (!mptcp_pm_should_add_signal(msk))
205 mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_SEND_ACK);
208 void mptcp_pm_rm_addr_received(struct mptcp_sock *msk, u8 rm_id)
210 struct mptcp_pm_data *pm = &msk->pm;
212 pr_debug("msk=%p remote_id=%d", msk, rm_id);
214 mptcp_event_addr_removed(msk, rm_id);
216 spin_lock_bh(&pm->lock);
217 mptcp_pm_schedule_work(msk, MPTCP_PM_RM_ADDR_RECEIVED);
219 spin_unlock_bh(&pm->lock);
222 void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup)
224 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
226 pr_debug("subflow->backup=%d, bkup=%d\n", subflow->backup, bkup);
227 subflow->backup = bkup;
229 mptcp_event(MPTCP_EVENT_SUB_PRIORITY, mptcp_sk(subflow->conn), sk, GFP_ATOMIC);
232 /* path manager helpers */
234 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
235 struct mptcp_addr_info *saddr, bool *echo, bool *port)
239 spin_lock_bh(&msk->pm.lock);
241 /* double check after the lock is acquired */
242 if (!mptcp_pm_should_add_signal(msk))
245 *echo = mptcp_pm_should_add_signal_echo(msk);
246 *port = mptcp_pm_should_add_signal_port(msk);
248 if (remaining < mptcp_add_addr_len(msk->pm.local.family, *echo, *port))
251 *saddr = msk->pm.local;
252 WRITE_ONCE(msk->pm.addr_signal, 0);
256 spin_unlock_bh(&msk->pm.lock);
260 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
265 spin_lock_bh(&msk->pm.lock);
267 /* double check after the lock is acquired */
268 if (!mptcp_pm_should_rm_signal(msk))
271 if (remaining < TCPOLEN_MPTCP_RM_ADDR_BASE)
274 *rm_id = msk->pm.rm_id;
275 WRITE_ONCE(msk->pm.addr_signal, 0);
279 spin_unlock_bh(&msk->pm.lock);
283 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
285 return mptcp_pm_nl_get_local_id(msk, skc);
288 void mptcp_pm_data_init(struct mptcp_sock *msk)
290 msk->pm.add_addr_signaled = 0;
291 msk->pm.add_addr_accepted = 0;
292 msk->pm.local_addr_used = 0;
293 msk->pm.subflows = 0;
295 WRITE_ONCE(msk->pm.work_pending, false);
296 WRITE_ONCE(msk->pm.addr_signal, 0);
297 WRITE_ONCE(msk->pm.accept_addr, false);
298 WRITE_ONCE(msk->pm.accept_subflow, false);
301 spin_lock_init(&msk->pm.lock);
302 INIT_LIST_HEAD(&msk->pm.anno_list);
304 mptcp_pm_nl_data_init(msk);
307 void __init mptcp_pm_init(void)