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>
15 /* path manager command handlers */
17 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
18 const struct mptcp_addr_info *addr,
21 u8 add_addr = READ_ONCE(msk->pm.addr_signal);
23 pr_debug("msk=%p, local_id=%d", msk, addr->id);
25 lockdep_assert_held(&msk->pm.lock);
28 pr_warn("addr_signal error, add_addr=%d", add_addr);
32 msk->pm.local = *addr;
33 add_addr |= BIT(MPTCP_ADD_ADDR_SIGNAL);
35 add_addr |= BIT(MPTCP_ADD_ADDR_ECHO);
36 if (addr->family == AF_INET6)
37 add_addr |= BIT(MPTCP_ADD_ADDR_IPV6);
39 add_addr |= BIT(MPTCP_ADD_ADDR_PORT);
40 WRITE_ONCE(msk->pm.addr_signal, add_addr);
44 int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list)
46 u8 rm_addr = READ_ONCE(msk->pm.addr_signal);
48 pr_debug("msk=%p, rm_list_nr=%d", msk, rm_list->nr);
51 pr_warn("addr_signal error, rm_addr=%d", rm_addr);
55 msk->pm.rm_list_tx = *rm_list;
56 rm_addr |= BIT(MPTCP_RM_ADDR_SIGNAL);
57 WRITE_ONCE(msk->pm.addr_signal, rm_addr);
58 mptcp_pm_nl_addr_send_ack(msk);
62 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list)
64 pr_debug("msk=%p, rm_list_nr=%d", msk, rm_list->nr);
66 spin_lock_bh(&msk->pm.lock);
67 mptcp_pm_nl_rm_subflow_received(msk, rm_list);
68 spin_unlock_bh(&msk->pm.lock);
72 /* path manager event handlers */
74 void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side)
76 struct mptcp_pm_data *pm = &msk->pm;
78 pr_debug("msk=%p, token=%u side=%d", msk, msk->token, server_side);
80 WRITE_ONCE(pm->server_side, server_side);
81 mptcp_event(MPTCP_EVENT_CREATED, msk, ssk, GFP_ATOMIC);
84 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
86 struct mptcp_pm_data *pm = &msk->pm;
87 unsigned int subflows_max;
90 subflows_max = mptcp_pm_get_subflows_max(msk);
92 pr_debug("msk=%p subflows=%d max=%d allow=%d", msk, pm->subflows,
93 subflows_max, READ_ONCE(pm->accept_subflow));
95 /* try to avoid acquiring the lock below */
96 if (!READ_ONCE(pm->accept_subflow))
99 spin_lock_bh(&pm->lock);
100 if (READ_ONCE(pm->accept_subflow)) {
101 ret = pm->subflows < subflows_max;
102 if (ret && ++pm->subflows == subflows_max)
103 WRITE_ONCE(pm->accept_subflow, false);
105 spin_unlock_bh(&pm->lock);
110 /* return true if the new status bit is currently cleared, that is, this event
111 * can be server, eventually by an already scheduled work
113 static bool mptcp_pm_schedule_work(struct mptcp_sock *msk,
114 enum mptcp_pm_status new_status)
116 pr_debug("msk=%p status=%x new=%lx", msk, msk->pm.status,
118 if (msk->pm.status & BIT(new_status))
121 msk->pm.status |= BIT(new_status);
122 mptcp_schedule_work((struct sock *)msk);
126 void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk, gfp_t gfp)
128 struct mptcp_pm_data *pm = &msk->pm;
129 bool announce = false;
131 pr_debug("msk=%p", msk);
133 spin_lock_bh(&pm->lock);
135 /* mptcp_pm_fully_established() can be invoked by multiple
136 * racing paths - accept() and check_fully_established()
137 * be sure to serve this event only once.
139 if (READ_ONCE(pm->work_pending) &&
140 !(msk->pm.status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)))
141 mptcp_pm_schedule_work(msk, MPTCP_PM_ESTABLISHED);
143 if ((msk->pm.status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)) == 0)
146 msk->pm.status |= BIT(MPTCP_PM_ALREADY_ESTABLISHED);
147 spin_unlock_bh(&pm->lock);
150 mptcp_event(MPTCP_EVENT_ESTABLISHED, msk, ssk, gfp);
153 void mptcp_pm_connection_closed(struct mptcp_sock *msk)
155 pr_debug("msk=%p", msk);
158 void mptcp_pm_subflow_established(struct mptcp_sock *msk)
160 struct mptcp_pm_data *pm = &msk->pm;
162 pr_debug("msk=%p", msk);
164 if (!READ_ONCE(pm->work_pending))
167 spin_lock_bh(&pm->lock);
169 if (READ_ONCE(pm->work_pending))
170 mptcp_pm_schedule_work(msk, MPTCP_PM_SUBFLOW_ESTABLISHED);
172 spin_unlock_bh(&pm->lock);
175 void mptcp_pm_subflow_closed(struct mptcp_sock *msk, u8 id)
177 pr_debug("msk=%p", msk);
180 void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
181 const struct mptcp_addr_info *addr)
183 struct mptcp_pm_data *pm = &msk->pm;
185 pr_debug("msk=%p remote_id=%d accept=%d", msk, addr->id,
186 READ_ONCE(pm->accept_addr));
188 mptcp_event_addr_announced(msk, addr);
190 spin_lock_bh(&pm->lock);
192 if (!READ_ONCE(pm->accept_addr)) {
193 mptcp_pm_announce_addr(msk, addr, true);
194 mptcp_pm_add_addr_send_ack(msk);
195 } else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) {
199 spin_unlock_bh(&pm->lock);
202 void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
203 struct mptcp_addr_info *addr)
205 struct mptcp_pm_data *pm = &msk->pm;
207 pr_debug("msk=%p", msk);
209 spin_lock_bh(&pm->lock);
211 if (mptcp_lookup_anno_list_by_saddr(msk, addr) && READ_ONCE(pm->work_pending))
212 mptcp_pm_schedule_work(msk, MPTCP_PM_SUBFLOW_ESTABLISHED);
214 spin_unlock_bh(&pm->lock);
217 void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk)
219 if (!mptcp_pm_should_add_signal(msk))
222 mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_SEND_ACK);
225 void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
226 const struct mptcp_rm_list *rm_list)
228 struct mptcp_pm_data *pm = &msk->pm;
231 pr_debug("msk=%p remote_ids_nr=%d", msk, rm_list->nr);
233 for (i = 0; i < rm_list->nr; i++)
234 mptcp_event_addr_removed(msk, rm_list->ids[i]);
236 spin_lock_bh(&pm->lock);
237 mptcp_pm_schedule_work(msk, MPTCP_PM_RM_ADDR_RECEIVED);
238 pm->rm_list_rx = *rm_list;
239 spin_unlock_bh(&pm->lock);
242 void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup)
244 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
246 pr_debug("subflow->backup=%d, bkup=%d\n", subflow->backup, bkup);
247 subflow->backup = bkup;
249 mptcp_event(MPTCP_EVENT_SUB_PRIORITY, mptcp_sk(subflow->conn), sk, GFP_ATOMIC);
252 /* path manager helpers */
254 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
255 struct mptcp_addr_info *saddr, bool *echo, bool *port)
259 spin_lock_bh(&msk->pm.lock);
261 /* double check after the lock is acquired */
262 if (!mptcp_pm_should_add_signal(msk))
265 *echo = mptcp_pm_should_add_signal_echo(msk);
266 *port = mptcp_pm_should_add_signal_port(msk);
268 if (remaining < mptcp_add_addr_len(msk->pm.local.family, *echo, *port))
271 *saddr = msk->pm.local;
272 WRITE_ONCE(msk->pm.addr_signal, 0);
276 spin_unlock_bh(&msk->pm.lock);
280 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
281 struct mptcp_rm_list *rm_list)
283 int ret = false, len;
285 spin_lock_bh(&msk->pm.lock);
287 /* double check after the lock is acquired */
288 if (!mptcp_pm_should_rm_signal(msk))
291 len = mptcp_rm_addr_len(&msk->pm.rm_list_tx);
293 WRITE_ONCE(msk->pm.addr_signal, 0);
299 *rm_list = msk->pm.rm_list_tx;
300 WRITE_ONCE(msk->pm.addr_signal, 0);
304 spin_unlock_bh(&msk->pm.lock);
308 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
310 return mptcp_pm_nl_get_local_id(msk, skc);
313 void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
315 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
316 u32 rcv_tstamp = READ_ONCE(tcp_sk(ssk)->rcv_tstamp);
318 /* keep track of rtx periods with no progress */
319 if (!subflow->stale_count) {
320 subflow->stale_rcv_tstamp = rcv_tstamp;
321 subflow->stale_count++;
322 } else if (subflow->stale_rcv_tstamp == rcv_tstamp) {
323 if (subflow->stale_count < U8_MAX)
324 subflow->stale_count++;
325 mptcp_pm_nl_subflow_chk_stale(msk, ssk);
327 subflow->stale_count = 0;
328 mptcp_subflow_set_active(subflow);
332 void mptcp_pm_data_init(struct mptcp_sock *msk)
334 msk->pm.add_addr_signaled = 0;
335 msk->pm.add_addr_accepted = 0;
336 msk->pm.local_addr_used = 0;
337 msk->pm.subflows = 0;
338 msk->pm.rm_list_tx.nr = 0;
339 msk->pm.rm_list_rx.nr = 0;
340 WRITE_ONCE(msk->pm.work_pending, false);
341 WRITE_ONCE(msk->pm.addr_signal, 0);
342 WRITE_ONCE(msk->pm.accept_addr, false);
343 WRITE_ONCE(msk->pm.accept_subflow, false);
344 WRITE_ONCE(msk->pm.remote_deny_join_id0, false);
347 spin_lock_init(&msk->pm.lock);
348 INIT_LIST_HEAD(&msk->pm.anno_list);
350 mptcp_pm_nl_data_init(msk);
353 void __init mptcp_pm_init(void)