Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
9b73896a TH |
2 | /* |
3 | * Kernel Connection Multiplexor | |
4 | * | |
5 | * Copyright (c) 2016 Tom Herbert <tom@herbertland.com> | |
9b73896a TH |
6 | */ |
7 | ||
ab7ac4eb TH |
8 | #include <linux/bpf.h> |
9 | #include <linux/errno.h> | |
10 | #include <linux/errqueue.h> | |
11 | #include <linux/file.h> | |
b6459415 | 12 | #include <linux/filter.h> |
ab7ac4eb TH |
13 | #include <linux/in.h> |
14 | #include <linux/kernel.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/net.h> | |
17 | #include <linux/netdevice.h> | |
18 | #include <linux/poll.h> | |
19 | #include <linux/rculist.h> | |
20 | #include <linux/skbuff.h> | |
21 | #include <linux/socket.h> | |
22 | #include <linux/uaccess.h> | |
23 | #include <linux/workqueue.h> | |
c0338aff | 24 | #include <linux/syscalls.h> |
174cd4b1 IM |
25 | #include <linux/sched/signal.h> |
26 | ||
ab7ac4eb TH |
27 | #include <net/kcm.h> |
28 | #include <net/netns/generic.h> | |
29 | #include <net/sock.h> | |
ab7ac4eb | 30 | #include <uapi/linux/kcm.h> |
40e0b090 | 31 | #include <trace/events/sock.h> |
ab7ac4eb TH |
32 | |
33 | unsigned int kcm_net_id; | |
34 | ||
35 | static struct kmem_cache *kcm_psockp __read_mostly; | |
36 | static struct kmem_cache *kcm_muxp __read_mostly; | |
37 | static struct workqueue_struct *kcm_wq; | |
38 | ||
39 | static inline struct kcm_sock *kcm_sk(const struct sock *sk) | |
40 | { | |
41 | return (struct kcm_sock *)sk; | |
42 | } | |
43 | ||
44 | static inline struct kcm_tx_msg *kcm_tx_msg(struct sk_buff *skb) | |
45 | { | |
46 | return (struct kcm_tx_msg *)skb->cb; | |
47 | } | |
48 | ||
ab7ac4eb TH |
49 | static void report_csk_error(struct sock *csk, int err) |
50 | { | |
51 | csk->sk_err = EPIPE; | |
e3ae2365 | 52 | sk_error_report(csk); |
ab7ac4eb TH |
53 | } |
54 | ||
ab7ac4eb TH |
55 | static void kcm_abort_tx_psock(struct kcm_psock *psock, int err, |
56 | bool wakeup_kcm) | |
57 | { | |
58 | struct sock *csk = psock->sk; | |
59 | struct kcm_mux *mux = psock->mux; | |
60 | ||
61 | /* Unrecoverable error in transmit */ | |
62 | ||
63 | spin_lock_bh(&mux->lock); | |
64 | ||
65 | if (psock->tx_stopped) { | |
66 | spin_unlock_bh(&mux->lock); | |
67 | return; | |
68 | } | |
69 | ||
70 | psock->tx_stopped = 1; | |
cd6e111b | 71 | KCM_STATS_INCR(psock->stats.tx_aborts); |
ab7ac4eb TH |
72 | |
73 | if (!psock->tx_kcm) { | |
74 | /* Take off psocks_avail list */ | |
75 | list_del(&psock->psock_avail_list); | |
76 | } else if (wakeup_kcm) { | |
77 | /* In this case psock is being aborted while outside of | |
78 | * write_msgs and psock is reserved. Schedule tx_work | |
79 | * to handle the failure there. Need to commit tx_stopped | |
80 | * before queuing work. | |
81 | */ | |
82 | smp_mb(); | |
83 | ||
84 | queue_work(kcm_wq, &psock->tx_kcm->tx_work); | |
85 | } | |
86 | ||
87 | spin_unlock_bh(&mux->lock); | |
88 | ||
89 | /* Report error on lower socket */ | |
90 | report_csk_error(csk, err); | |
91 | } | |
92 | ||
cd6e111b TH |
93 | /* RX mux lock held. */ |
94 | static void kcm_update_rx_mux_stats(struct kcm_mux *mux, | |
95 | struct kcm_psock *psock) | |
96 | { | |
9b73896a | 97 | STRP_STATS_ADD(mux->stats.rx_bytes, |
bbb03029 | 98 | psock->strp.stats.bytes - |
9b73896a | 99 | psock->saved_rx_bytes); |
cd6e111b | 100 | mux->stats.rx_msgs += |
bbb03029 TH |
101 | psock->strp.stats.msgs - psock->saved_rx_msgs; |
102 | psock->saved_rx_msgs = psock->strp.stats.msgs; | |
103 | psock->saved_rx_bytes = psock->strp.stats.bytes; | |
cd6e111b TH |
104 | } |
105 | ||
106 | static void kcm_update_tx_mux_stats(struct kcm_mux *mux, | |
107 | struct kcm_psock *psock) | |
108 | { | |
109 | KCM_STATS_ADD(mux->stats.tx_bytes, | |
110 | psock->stats.tx_bytes - psock->saved_tx_bytes); | |
111 | mux->stats.tx_msgs += | |
112 | psock->stats.tx_msgs - psock->saved_tx_msgs; | |
113 | psock->saved_tx_msgs = psock->stats.tx_msgs; | |
114 | psock->saved_tx_bytes = psock->stats.tx_bytes; | |
115 | } | |
116 | ||
ab7ac4eb TH |
117 | static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); |
118 | ||
119 | /* KCM is ready to receive messages on its queue-- either the KCM is new or | |
120 | * has become unblocked after being blocked on full socket buffer. Queue any | |
121 | * pending ready messages on a psock. RX mux lock held. | |
122 | */ | |
123 | static void kcm_rcv_ready(struct kcm_sock *kcm) | |
124 | { | |
125 | struct kcm_mux *mux = kcm->mux; | |
126 | struct kcm_psock *psock; | |
127 | struct sk_buff *skb; | |
128 | ||
129 | if (unlikely(kcm->rx_wait || kcm->rx_psock || kcm->rx_disabled)) | |
130 | return; | |
131 | ||
132 | while (unlikely((skb = __skb_dequeue(&mux->rx_hold_queue)))) { | |
133 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { | |
134 | /* Assuming buffer limit has been reached */ | |
135 | skb_queue_head(&mux->rx_hold_queue, skb); | |
136 | WARN_ON(!sk_rmem_alloc_get(&kcm->sk)); | |
137 | return; | |
138 | } | |
139 | } | |
140 | ||
141 | while (!list_empty(&mux->psocks_ready)) { | |
142 | psock = list_first_entry(&mux->psocks_ready, struct kcm_psock, | |
143 | psock_ready_list); | |
144 | ||
145 | if (kcm_queue_rcv_skb(&kcm->sk, psock->ready_rx_msg)) { | |
146 | /* Assuming buffer limit has been reached */ | |
147 | WARN_ON(!sk_rmem_alloc_get(&kcm->sk)); | |
148 | return; | |
149 | } | |
150 | ||
151 | /* Consumed the ready message on the psock. Schedule rx_work to | |
152 | * get more messages. | |
153 | */ | |
154 | list_del(&psock->psock_ready_list); | |
155 | psock->ready_rx_msg = NULL; | |
ab7ac4eb TH |
156 | /* Commit clearing of ready_rx_msg for queuing work */ |
157 | smp_mb(); | |
158 | ||
9b73896a TH |
159 | strp_unpause(&psock->strp); |
160 | strp_check_rcv(&psock->strp); | |
ab7ac4eb TH |
161 | } |
162 | ||
163 | /* Buffer limit is okay now, add to ready list */ | |
164 | list_add_tail(&kcm->wait_rx_list, | |
165 | &kcm->mux->kcm_rx_waiters); | |
0c745b51 ED |
166 | /* paired with lockless reads in kcm_rfree() */ |
167 | WRITE_ONCE(kcm->rx_wait, true); | |
ab7ac4eb TH |
168 | } |
169 | ||
170 | static void kcm_rfree(struct sk_buff *skb) | |
171 | { | |
172 | struct sock *sk = skb->sk; | |
173 | struct kcm_sock *kcm = kcm_sk(sk); | |
174 | struct kcm_mux *mux = kcm->mux; | |
175 | unsigned int len = skb->truesize; | |
176 | ||
177 | sk_mem_uncharge(sk, len); | |
178 | atomic_sub(len, &sk->sk_rmem_alloc); | |
179 | ||
180 | /* For reading rx_wait and rx_psock without holding lock */ | |
181 | smp_mb__after_atomic(); | |
182 | ||
0c745b51 | 183 | if (!READ_ONCE(kcm->rx_wait) && !READ_ONCE(kcm->rx_psock) && |
ab7ac4eb TH |
184 | sk_rmem_alloc_get(sk) < sk->sk_rcvlowat) { |
185 | spin_lock_bh(&mux->rx_lock); | |
186 | kcm_rcv_ready(kcm); | |
187 | spin_unlock_bh(&mux->rx_lock); | |
188 | } | |
189 | } | |
190 | ||
191 | static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) | |
192 | { | |
193 | struct sk_buff_head *list = &sk->sk_receive_queue; | |
194 | ||
195 | if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) | |
196 | return -ENOMEM; | |
197 | ||
198 | if (!sk_rmem_schedule(sk, skb, skb->truesize)) | |
199 | return -ENOBUFS; | |
200 | ||
201 | skb->dev = NULL; | |
202 | ||
203 | skb_orphan(skb); | |
204 | skb->sk = sk; | |
205 | skb->destructor = kcm_rfree; | |
206 | atomic_add(skb->truesize, &sk->sk_rmem_alloc); | |
207 | sk_mem_charge(sk, skb->truesize); | |
208 | ||
209 | skb_queue_tail(list, skb); | |
210 | ||
211 | if (!sock_flag(sk, SOCK_DEAD)) | |
212 | sk->sk_data_ready(sk); | |
213 | ||
214 | return 0; | |
215 | } | |
216 | ||
217 | /* Requeue received messages for a kcm socket to other kcm sockets. This is | |
218 | * called with a kcm socket is receive disabled. | |
219 | * RX mux lock held. | |
220 | */ | |
221 | static void requeue_rx_msgs(struct kcm_mux *mux, struct sk_buff_head *head) | |
222 | { | |
223 | struct sk_buff *skb; | |
224 | struct kcm_sock *kcm; | |
225 | ||
5121197e | 226 | while ((skb = skb_dequeue(head))) { |
ab7ac4eb TH |
227 | /* Reset destructor to avoid calling kcm_rcv_ready */ |
228 | skb->destructor = sock_rfree; | |
229 | skb_orphan(skb); | |
230 | try_again: | |
231 | if (list_empty(&mux->kcm_rx_waiters)) { | |
232 | skb_queue_tail(&mux->rx_hold_queue, skb); | |
233 | continue; | |
234 | } | |
235 | ||
236 | kcm = list_first_entry(&mux->kcm_rx_waiters, | |
237 | struct kcm_sock, wait_rx_list); | |
238 | ||
239 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { | |
240 | /* Should mean socket buffer full */ | |
241 | list_del(&kcm->wait_rx_list); | |
0c745b51 ED |
242 | /* paired with lockless reads in kcm_rfree() */ |
243 | WRITE_ONCE(kcm->rx_wait, false); | |
ab7ac4eb TH |
244 | |
245 | /* Commit rx_wait to read in kcm_free */ | |
246 | smp_wmb(); | |
247 | ||
248 | goto try_again; | |
249 | } | |
250 | } | |
251 | } | |
252 | ||
253 | /* Lower sock lock held */ | |
254 | static struct kcm_sock *reserve_rx_kcm(struct kcm_psock *psock, | |
255 | struct sk_buff *head) | |
256 | { | |
257 | struct kcm_mux *mux = psock->mux; | |
258 | struct kcm_sock *kcm; | |
259 | ||
260 | WARN_ON(psock->ready_rx_msg); | |
261 | ||
262 | if (psock->rx_kcm) | |
263 | return psock->rx_kcm; | |
264 | ||
265 | spin_lock_bh(&mux->rx_lock); | |
266 | ||
267 | if (psock->rx_kcm) { | |
268 | spin_unlock_bh(&mux->rx_lock); | |
269 | return psock->rx_kcm; | |
270 | } | |
271 | ||
cd6e111b TH |
272 | kcm_update_rx_mux_stats(mux, psock); |
273 | ||
ab7ac4eb TH |
274 | if (list_empty(&mux->kcm_rx_waiters)) { |
275 | psock->ready_rx_msg = head; | |
9b73896a | 276 | strp_pause(&psock->strp); |
ab7ac4eb TH |
277 | list_add_tail(&psock->psock_ready_list, |
278 | &mux->psocks_ready); | |
279 | spin_unlock_bh(&mux->rx_lock); | |
280 | return NULL; | |
281 | } | |
282 | ||
283 | kcm = list_first_entry(&mux->kcm_rx_waiters, | |
284 | struct kcm_sock, wait_rx_list); | |
285 | list_del(&kcm->wait_rx_list); | |
0c745b51 ED |
286 | /* paired with lockless reads in kcm_rfree() */ |
287 | WRITE_ONCE(kcm->rx_wait, false); | |
ab7ac4eb TH |
288 | |
289 | psock->rx_kcm = kcm; | |
15e4dabd ED |
290 | /* paired with lockless reads in kcm_rfree() */ |
291 | WRITE_ONCE(kcm->rx_psock, psock); | |
ab7ac4eb TH |
292 | |
293 | spin_unlock_bh(&mux->rx_lock); | |
294 | ||
295 | return kcm; | |
296 | } | |
297 | ||
298 | static void kcm_done(struct kcm_sock *kcm); | |
299 | ||
300 | static void kcm_done_work(struct work_struct *w) | |
301 | { | |
302 | kcm_done(container_of(w, struct kcm_sock, done_work)); | |
303 | } | |
304 | ||
305 | /* Lower sock held */ | |
306 | static void unreserve_rx_kcm(struct kcm_psock *psock, | |
307 | bool rcv_ready) | |
308 | { | |
309 | struct kcm_sock *kcm = psock->rx_kcm; | |
310 | struct kcm_mux *mux = psock->mux; | |
311 | ||
312 | if (!kcm) | |
313 | return; | |
314 | ||
315 | spin_lock_bh(&mux->rx_lock); | |
316 | ||
317 | psock->rx_kcm = NULL; | |
15e4dabd ED |
318 | /* paired with lockless reads in kcm_rfree() */ |
319 | WRITE_ONCE(kcm->rx_psock, NULL); | |
ab7ac4eb TH |
320 | |
321 | /* Commit kcm->rx_psock before sk_rmem_alloc_get to sync with | |
322 | * kcm_rfree | |
323 | */ | |
324 | smp_mb(); | |
325 | ||
326 | if (unlikely(kcm->done)) { | |
327 | spin_unlock_bh(&mux->rx_lock); | |
328 | ||
329 | /* Need to run kcm_done in a task since we need to qcquire | |
330 | * callback locks which may already be held here. | |
331 | */ | |
332 | INIT_WORK(&kcm->done_work, kcm_done_work); | |
333 | schedule_work(&kcm->done_work); | |
334 | return; | |
335 | } | |
336 | ||
337 | if (unlikely(kcm->rx_disabled)) { | |
338 | requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue); | |
339 | } else if (rcv_ready || unlikely(!sk_rmem_alloc_get(&kcm->sk))) { | |
340 | /* Check for degenerative race with rx_wait that all | |
341 | * data was dequeued (accounted for in kcm_rfree). | |
342 | */ | |
343 | kcm_rcv_ready(kcm); | |
344 | } | |
345 | spin_unlock_bh(&mux->rx_lock); | |
346 | } | |
347 | ||
ab7ac4eb | 348 | /* Lower sock lock held */ |
96a59083 | 349 | static void psock_data_ready(struct sock *sk) |
ab7ac4eb TH |
350 | { |
351 | struct kcm_psock *psock; | |
352 | ||
40e0b090 PY |
353 | trace_sk_data_ready(sk); |
354 | ||
ab7ac4eb TH |
355 | read_lock_bh(&sk->sk_callback_lock); |
356 | ||
357 | psock = (struct kcm_psock *)sk->sk_user_data; | |
9b73896a | 358 | if (likely(psock)) |
96a59083 | 359 | strp_data_ready(&psock->strp); |
ab7ac4eb | 360 | |
ab7ac4eb TH |
361 | read_unlock_bh(&sk->sk_callback_lock); |
362 | } | |
363 | ||
9b73896a TH |
364 | /* Called with lower sock held */ |
365 | static void kcm_rcv_strparser(struct strparser *strp, struct sk_buff *skb) | |
ab7ac4eb | 366 | { |
9b73896a TH |
367 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
368 | struct kcm_sock *kcm; | |
ab7ac4eb | 369 | |
9b73896a TH |
370 | try_queue: |
371 | kcm = reserve_rx_kcm(psock, skb); | |
372 | if (!kcm) { | |
373 | /* Unable to reserve a KCM, message is held in psock and strp | |
374 | * is paused. | |
375 | */ | |
376 | return; | |
377 | } | |
ab7ac4eb | 378 | |
9b73896a TH |
379 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { |
380 | /* Should mean socket buffer full */ | |
381 | unreserve_rx_kcm(psock, false); | |
382 | goto try_queue; | |
383 | } | |
ab7ac4eb TH |
384 | } |
385 | ||
9b73896a | 386 | static int kcm_parse_func_strparser(struct strparser *strp, struct sk_buff *skb) |
ab7ac4eb | 387 | { |
9b73896a TH |
388 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
389 | struct bpf_prog *prog = psock->bpf_prog; | |
0355d6c1 | 390 | int res; |
9b73896a | 391 | |
3d9f773c | 392 | res = bpf_prog_run_pin_on_cpu(prog, skb); |
0355d6c1 | 393 | return res; |
ab7ac4eb TH |
394 | } |
395 | ||
9b73896a | 396 | static int kcm_read_sock_done(struct strparser *strp, int err) |
ab7ac4eb | 397 | { |
9b73896a TH |
398 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
399 | ||
400 | unreserve_rx_kcm(psock, true); | |
401 | ||
402 | return err; | |
ab7ac4eb TH |
403 | } |
404 | ||
96a59083 | 405 | static void psock_state_change(struct sock *sk) |
ab7ac4eb | 406 | { |
a9a08845 LT |
407 | /* TCP only does a EPOLLIN for a half close. Do a EPOLLHUP here |
408 | * since application will normally not poll with EPOLLIN | |
ab7ac4eb TH |
409 | * on the TCP sockets. |
410 | */ | |
411 | ||
412 | report_csk_error(sk, EPIPE); | |
413 | } | |
414 | ||
96a59083 | 415 | static void psock_write_space(struct sock *sk) |
ab7ac4eb TH |
416 | { |
417 | struct kcm_psock *psock; | |
418 | struct kcm_mux *mux; | |
419 | struct kcm_sock *kcm; | |
420 | ||
421 | read_lock_bh(&sk->sk_callback_lock); | |
422 | ||
423 | psock = (struct kcm_psock *)sk->sk_user_data; | |
424 | if (unlikely(!psock)) | |
425 | goto out; | |
ab7ac4eb TH |
426 | mux = psock->mux; |
427 | ||
428 | spin_lock_bh(&mux->lock); | |
429 | ||
430 | /* Check if the socket is reserved so someone is waiting for sending. */ | |
431 | kcm = psock->tx_kcm; | |
9b73896a | 432 | if (kcm && !unlikely(kcm->tx_stopped)) |
ab7ac4eb TH |
433 | queue_work(kcm_wq, &kcm->tx_work); |
434 | ||
435 | spin_unlock_bh(&mux->lock); | |
436 | out: | |
437 | read_unlock_bh(&sk->sk_callback_lock); | |
438 | } | |
439 | ||
440 | static void unreserve_psock(struct kcm_sock *kcm); | |
441 | ||
442 | /* kcm sock is locked. */ | |
443 | static struct kcm_psock *reserve_psock(struct kcm_sock *kcm) | |
444 | { | |
445 | struct kcm_mux *mux = kcm->mux; | |
446 | struct kcm_psock *psock; | |
447 | ||
448 | psock = kcm->tx_psock; | |
449 | ||
450 | smp_rmb(); /* Must read tx_psock before tx_wait */ | |
451 | ||
452 | if (psock) { | |
453 | WARN_ON(kcm->tx_wait); | |
454 | if (unlikely(psock->tx_stopped)) | |
455 | unreserve_psock(kcm); | |
456 | else | |
457 | return kcm->tx_psock; | |
458 | } | |
459 | ||
460 | spin_lock_bh(&mux->lock); | |
461 | ||
462 | /* Check again under lock to see if psock was reserved for this | |
463 | * psock via psock_unreserve. | |
464 | */ | |
465 | psock = kcm->tx_psock; | |
466 | if (unlikely(psock)) { | |
467 | WARN_ON(kcm->tx_wait); | |
468 | spin_unlock_bh(&mux->lock); | |
469 | return kcm->tx_psock; | |
470 | } | |
471 | ||
472 | if (!list_empty(&mux->psocks_avail)) { | |
473 | psock = list_first_entry(&mux->psocks_avail, | |
474 | struct kcm_psock, | |
475 | psock_avail_list); | |
476 | list_del(&psock->psock_avail_list); | |
477 | if (kcm->tx_wait) { | |
478 | list_del(&kcm->wait_psock_list); | |
479 | kcm->tx_wait = false; | |
480 | } | |
481 | kcm->tx_psock = psock; | |
482 | psock->tx_kcm = kcm; | |
cd6e111b | 483 | KCM_STATS_INCR(psock->stats.reserved); |
ab7ac4eb TH |
484 | } else if (!kcm->tx_wait) { |
485 | list_add_tail(&kcm->wait_psock_list, | |
486 | &mux->kcm_tx_waiters); | |
487 | kcm->tx_wait = true; | |
488 | } | |
489 | ||
490 | spin_unlock_bh(&mux->lock); | |
491 | ||
492 | return psock; | |
493 | } | |
494 | ||
495 | /* mux lock held */ | |
496 | static void psock_now_avail(struct kcm_psock *psock) | |
497 | { | |
498 | struct kcm_mux *mux = psock->mux; | |
499 | struct kcm_sock *kcm; | |
500 | ||
501 | if (list_empty(&mux->kcm_tx_waiters)) { | |
502 | list_add_tail(&psock->psock_avail_list, | |
503 | &mux->psocks_avail); | |
504 | } else { | |
505 | kcm = list_first_entry(&mux->kcm_tx_waiters, | |
506 | struct kcm_sock, | |
507 | wait_psock_list); | |
508 | list_del(&kcm->wait_psock_list); | |
509 | kcm->tx_wait = false; | |
510 | psock->tx_kcm = kcm; | |
511 | ||
512 | /* Commit before changing tx_psock since that is read in | |
513 | * reserve_psock before queuing work. | |
514 | */ | |
515 | smp_mb(); | |
516 | ||
517 | kcm->tx_psock = psock; | |
cd6e111b | 518 | KCM_STATS_INCR(psock->stats.reserved); |
ab7ac4eb TH |
519 | queue_work(kcm_wq, &kcm->tx_work); |
520 | } | |
521 | } | |
522 | ||
523 | /* kcm sock is locked. */ | |
524 | static void unreserve_psock(struct kcm_sock *kcm) | |
525 | { | |
526 | struct kcm_psock *psock; | |
527 | struct kcm_mux *mux = kcm->mux; | |
528 | ||
529 | spin_lock_bh(&mux->lock); | |
530 | ||
531 | psock = kcm->tx_psock; | |
532 | ||
533 | if (WARN_ON(!psock)) { | |
534 | spin_unlock_bh(&mux->lock); | |
535 | return; | |
536 | } | |
537 | ||
538 | smp_rmb(); /* Read tx_psock before tx_wait */ | |
539 | ||
cd6e111b TH |
540 | kcm_update_tx_mux_stats(mux, psock); |
541 | ||
ab7ac4eb TH |
542 | WARN_ON(kcm->tx_wait); |
543 | ||
544 | kcm->tx_psock = NULL; | |
545 | psock->tx_kcm = NULL; | |
cd6e111b | 546 | KCM_STATS_INCR(psock->stats.unreserved); |
ab7ac4eb TH |
547 | |
548 | if (unlikely(psock->tx_stopped)) { | |
549 | if (psock->done) { | |
550 | /* Deferred free */ | |
551 | list_del(&psock->psock_list); | |
552 | mux->psocks_cnt--; | |
553 | sock_put(psock->sk); | |
554 | fput(psock->sk->sk_socket->file); | |
555 | kmem_cache_free(kcm_psockp, psock); | |
556 | } | |
557 | ||
558 | /* Don't put back on available list */ | |
559 | ||
560 | spin_unlock_bh(&mux->lock); | |
561 | ||
562 | return; | |
563 | } | |
564 | ||
565 | psock_now_avail(psock); | |
566 | ||
567 | spin_unlock_bh(&mux->lock); | |
568 | } | |
569 | ||
cd6e111b TH |
570 | static void kcm_report_tx_retry(struct kcm_sock *kcm) |
571 | { | |
572 | struct kcm_mux *mux = kcm->mux; | |
573 | ||
574 | spin_lock_bh(&mux->lock); | |
575 | KCM_STATS_INCR(mux->stats.tx_retries); | |
576 | spin_unlock_bh(&mux->lock); | |
577 | } | |
578 | ||
ab7ac4eb TH |
579 | /* Write any messages ready on the kcm socket. Called with kcm sock lock |
580 | * held. Return bytes actually sent or error. | |
581 | */ | |
582 | static int kcm_write_msgs(struct kcm_sock *kcm) | |
583 | { | |
c31a25e1 | 584 | unsigned int total_sent = 0; |
ab7ac4eb TH |
585 | struct sock *sk = &kcm->sk; |
586 | struct kcm_psock *psock; | |
c31a25e1 | 587 | struct sk_buff *head; |
ab7ac4eb TH |
588 | int ret = 0; |
589 | ||
590 | kcm->tx_wait_more = false; | |
591 | psock = kcm->tx_psock; | |
592 | if (unlikely(psock && psock->tx_stopped)) { | |
593 | /* A reserved psock was aborted asynchronously. Unreserve | |
594 | * it and we'll retry the message. | |
595 | */ | |
596 | unreserve_psock(kcm); | |
cd6e111b | 597 | kcm_report_tx_retry(kcm); |
ab7ac4eb TH |
598 | if (skb_queue_empty(&sk->sk_write_queue)) |
599 | return 0; | |
600 | ||
c31a25e1 | 601 | kcm_tx_msg(skb_peek(&sk->sk_write_queue))->started_tx = false; |
ab7ac4eb TH |
602 | } |
603 | ||
c31a25e1 DH |
604 | retry: |
605 | while ((head = skb_peek(&sk->sk_write_queue))) { | |
606 | struct msghdr msg = { | |
607 | .msg_flags = MSG_DONTWAIT | MSG_SPLICE_PAGES, | |
608 | }; | |
609 | struct kcm_tx_msg *txm = kcm_tx_msg(head); | |
610 | struct sk_buff *skb; | |
611 | unsigned int msize; | |
612 | int i; | |
613 | ||
614 | if (!txm->started_tx) { | |
615 | psock = reserve_psock(kcm); | |
616 | if (!psock) | |
617 | goto out; | |
618 | skb = head; | |
619 | txm->frag_offset = 0; | |
620 | txm->sent = 0; | |
621 | txm->started_tx = true; | |
622 | } else { | |
623 | if (WARN_ON(!psock)) { | |
624 | ret = -EINVAL; | |
625 | goto out; | |
626 | } | |
627 | skb = txm->frag_skb; | |
ab7ac4eb | 628 | } |
ab7ac4eb | 629 | |
ab7ac4eb TH |
630 | if (WARN_ON(!skb_shinfo(skb)->nr_frags)) { |
631 | ret = -EINVAL; | |
632 | goto out; | |
633 | } | |
634 | ||
c31a25e1 DH |
635 | msize = 0; |
636 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) | |
637 | msize += skb_shinfo(skb)->frags[i].bv_len; | |
638 | ||
639 | iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, | |
640 | skb_shinfo(skb)->frags, skb_shinfo(skb)->nr_frags, | |
641 | msize); | |
642 | iov_iter_advance(&msg.msg_iter, txm->frag_offset); | |
ab7ac4eb | 643 | |
c31a25e1 | 644 | do { |
264ba53f | 645 | ret = sock_sendmsg(psock->sk->sk_socket, &msg); |
ab7ac4eb TH |
646 | if (ret <= 0) { |
647 | if (ret == -EAGAIN) { | |
648 | /* Save state to try again when there's | |
649 | * write space on the socket | |
650 | */ | |
ab7ac4eb | 651 | txm->frag_skb = skb; |
ab7ac4eb TH |
652 | ret = 0; |
653 | goto out; | |
654 | } | |
655 | ||
656 | /* Hard failure in sending message, abort this | |
657 | * psock since it has lost framing | |
71a2fae5 | 658 | * synchronization and retry sending the |
ab7ac4eb TH |
659 | * message from the beginning. |
660 | */ | |
661 | kcm_abort_tx_psock(psock, ret ? -ret : EPIPE, | |
662 | true); | |
663 | unreserve_psock(kcm); | |
9f8d0dc0 | 664 | psock = NULL; |
ab7ac4eb | 665 | |
c31a25e1 | 666 | txm->started_tx = false; |
cd6e111b | 667 | kcm_report_tx_retry(kcm); |
ab7ac4eb | 668 | ret = 0; |
c31a25e1 | 669 | goto retry; |
ab7ac4eb TH |
670 | } |
671 | ||
c31a25e1 DH |
672 | txm->sent += ret; |
673 | txm->frag_offset += ret; | |
cd6e111b | 674 | KCM_STATS_ADD(psock->stats.tx_bytes, ret); |
c31a25e1 | 675 | } while (msg.msg_iter.count > 0); |
ab7ac4eb TH |
676 | |
677 | if (skb == head) { | |
678 | if (skb_has_frag_list(skb)) { | |
c31a25e1 DH |
679 | txm->frag_skb = skb_shinfo(skb)->frag_list; |
680 | txm->frag_offset = 0; | |
681 | continue; | |
ab7ac4eb TH |
682 | } |
683 | } else if (skb->next) { | |
c31a25e1 DH |
684 | txm->frag_skb = skb->next; |
685 | txm->frag_offset = 0; | |
686 | continue; | |
ab7ac4eb TH |
687 | } |
688 | ||
689 | /* Successfully sent the whole packet, account for it. */ | |
c31a25e1 DH |
690 | sk->sk_wmem_queued -= txm->sent; |
691 | total_sent += txm->sent; | |
ab7ac4eb TH |
692 | skb_dequeue(&sk->sk_write_queue); |
693 | kfree_skb(head); | |
cd6e111b | 694 | KCM_STATS_INCR(psock->stats.tx_msgs); |
c31a25e1 | 695 | } |
ab7ac4eb TH |
696 | out: |
697 | if (!head) { | |
698 | /* Done with all queued messages. */ | |
699 | WARN_ON(!skb_queue_empty(&sk->sk_write_queue)); | |
9f8d0dc0 DH |
700 | if (psock) |
701 | unreserve_psock(kcm); | |
ab7ac4eb TH |
702 | } |
703 | ||
704 | /* Check if write space is available */ | |
705 | sk->sk_write_space(sk); | |
706 | ||
707 | return total_sent ? : ret; | |
708 | } | |
709 | ||
710 | static void kcm_tx_work(struct work_struct *w) | |
711 | { | |
712 | struct kcm_sock *kcm = container_of(w, struct kcm_sock, tx_work); | |
713 | struct sock *sk = &kcm->sk; | |
714 | int err; | |
715 | ||
716 | lock_sock(sk); | |
717 | ||
718 | /* Primarily for SOCK_DGRAM sockets, also handle asynchronous tx | |
719 | * aborts | |
720 | */ | |
721 | err = kcm_write_msgs(kcm); | |
722 | if (err < 0) { | |
723 | /* Hard failure in write, report error on KCM socket */ | |
724 | pr_warn("KCM: Hard failure on kcm_write_msgs %d\n", err); | |
725 | report_csk_error(&kcm->sk, -err); | |
726 | goto out; | |
727 | } | |
728 | ||
729 | /* Primarily for SOCK_SEQPACKET sockets */ | |
730 | if (likely(sk->sk_socket) && | |
731 | test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { | |
732 | clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
733 | sk->sk_write_space(sk); | |
734 | } | |
735 | ||
736 | out: | |
737 | release_sock(sk); | |
738 | } | |
739 | ||
740 | static void kcm_push(struct kcm_sock *kcm) | |
741 | { | |
742 | if (kcm->tx_wait_more) | |
743 | kcm_write_msgs(kcm); | |
744 | } | |
745 | ||
746 | static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) | |
747 | { | |
748 | struct sock *sk = sock->sk; | |
749 | struct kcm_sock *kcm = kcm_sk(sk); | |
750 | struct sk_buff *skb = NULL, *head = NULL; | |
751 | size_t copy, copied = 0; | |
752 | long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
753 | int eor = (sock->type == SOCK_DGRAM) ? | |
754 | !(msg->msg_flags & MSG_MORE) : !!(msg->msg_flags & MSG_EOR); | |
755 | int err = -EPIPE; | |
756 | ||
757 | lock_sock(sk); | |
758 | ||
759 | /* Per tcp_sendmsg this should be in poll */ | |
760 | sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); | |
761 | ||
762 | if (sk->sk_err) | |
763 | goto out_error; | |
764 | ||
765 | if (kcm->seq_skb) { | |
766 | /* Previously opened message */ | |
767 | head = kcm->seq_skb; | |
768 | skb = kcm_tx_msg(head)->last_skb; | |
769 | goto start; | |
770 | } | |
771 | ||
772 | /* Call the sk_stream functions to manage the sndbuf mem. */ | |
773 | if (!sk_stream_memory_free(sk)) { | |
774 | kcm_push(kcm); | |
775 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
776 | err = sk_stream_wait_memory(sk, &timeo); | |
777 | if (err) | |
778 | goto out_error; | |
779 | } | |
780 | ||
98e3862c WC |
781 | if (msg_data_left(msg)) { |
782 | /* New message, alloc head skb */ | |
ab7ac4eb | 783 | head = alloc_skb(0, sk->sk_allocation); |
98e3862c WC |
784 | while (!head) { |
785 | kcm_push(kcm); | |
786 | err = sk_stream_wait_memory(sk, &timeo); | |
787 | if (err) | |
788 | goto out_error; | |
ab7ac4eb | 789 | |
98e3862c WC |
790 | head = alloc_skb(0, sk->sk_allocation); |
791 | } | |
ab7ac4eb | 792 | |
98e3862c WC |
793 | skb = head; |
794 | ||
795 | /* Set ip_summed to CHECKSUM_UNNECESSARY to avoid calling | |
796 | * csum_and_copy_from_iter from skb_do_copy_data_nocache. | |
797 | */ | |
798 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
799 | } | |
ab7ac4eb TH |
800 | |
801 | start: | |
802 | while (msg_data_left(msg)) { | |
803 | bool merge = true; | |
804 | int i = skb_shinfo(skb)->nr_frags; | |
805 | struct page_frag *pfrag = sk_page_frag(sk); | |
806 | ||
807 | if (!sk_page_frag_refill(sk, pfrag)) | |
808 | goto wait_for_memory; | |
809 | ||
810 | if (!skb_can_coalesce(skb, i, pfrag->page, | |
811 | pfrag->offset)) { | |
812 | if (i == MAX_SKB_FRAGS) { | |
813 | struct sk_buff *tskb; | |
814 | ||
815 | tskb = alloc_skb(0, sk->sk_allocation); | |
816 | if (!tskb) | |
817 | goto wait_for_memory; | |
818 | ||
819 | if (head == skb) | |
820 | skb_shinfo(head)->frag_list = tskb; | |
821 | else | |
822 | skb->next = tskb; | |
823 | ||
824 | skb = tskb; | |
825 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
826 | continue; | |
827 | } | |
828 | merge = false; | |
829 | } | |
830 | ||
2b03bcae DH |
831 | if (msg->msg_flags & MSG_SPLICE_PAGES) { |
832 | copy = msg_data_left(msg); | |
833 | if (!sk_wmem_schedule(sk, copy)) | |
834 | goto wait_for_memory; | |
ab7ac4eb | 835 | |
2b03bcae DH |
836 | err = skb_splice_from_iter(skb, &msg->msg_iter, copy, |
837 | sk->sk_allocation); | |
838 | if (err < 0) { | |
839 | if (err == -EMSGSIZE) | |
840 | goto wait_for_memory; | |
841 | goto out_error; | |
842 | } | |
ab7ac4eb | 843 | |
2b03bcae DH |
844 | copy = err; |
845 | skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG; | |
846 | sk_wmem_queued_add(sk, copy); | |
847 | sk_mem_charge(sk, copy); | |
ab7ac4eb | 848 | |
2b03bcae DH |
849 | if (head != skb) |
850 | head->truesize += copy; | |
ab7ac4eb | 851 | } else { |
2b03bcae DH |
852 | copy = min_t(int, msg_data_left(msg), |
853 | pfrag->size - pfrag->offset); | |
854 | if (!sk_wmem_schedule(sk, copy)) | |
855 | goto wait_for_memory; | |
856 | ||
857 | err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb, | |
858 | pfrag->page, | |
859 | pfrag->offset, | |
860 | copy); | |
861 | if (err) | |
862 | goto out_error; | |
863 | ||
864 | /* Update the skb. */ | |
865 | if (merge) { | |
866 | skb_frag_size_add( | |
867 | &skb_shinfo(skb)->frags[i - 1], copy); | |
868 | } else { | |
869 | skb_fill_page_desc(skb, i, pfrag->page, | |
870 | pfrag->offset, copy); | |
871 | get_page(pfrag->page); | |
872 | } | |
873 | ||
874 | pfrag->offset += copy; | |
ab7ac4eb TH |
875 | } |
876 | ||
ab7ac4eb TH |
877 | copied += copy; |
878 | if (head != skb) { | |
879 | head->len += copy; | |
880 | head->data_len += copy; | |
881 | } | |
882 | ||
883 | continue; | |
884 | ||
885 | wait_for_memory: | |
886 | kcm_push(kcm); | |
887 | err = sk_stream_wait_memory(sk, &timeo); | |
888 | if (err) | |
889 | goto out_error; | |
890 | } | |
891 | ||
892 | if (eor) { | |
893 | bool not_busy = skb_queue_empty(&sk->sk_write_queue); | |
894 | ||
98e3862c WC |
895 | if (head) { |
896 | /* Message complete, queue it on send buffer */ | |
897 | __skb_queue_tail(&sk->sk_write_queue, head); | |
898 | kcm->seq_skb = NULL; | |
899 | KCM_STATS_INCR(kcm->stats.tx_msgs); | |
900 | } | |
ab7ac4eb TH |
901 | |
902 | if (msg->msg_flags & MSG_BATCH) { | |
903 | kcm->tx_wait_more = true; | |
904 | } else if (kcm->tx_wait_more || not_busy) { | |
905 | err = kcm_write_msgs(kcm); | |
906 | if (err < 0) { | |
907 | /* We got a hard error in write_msgs but have | |
908 | * already queued this message. Report an error | |
909 | * in the socket, but don't affect return value | |
910 | * from sendmsg | |
911 | */ | |
912 | pr_warn("KCM: Hard failure on kcm_write_msgs\n"); | |
913 | report_csk_error(&kcm->sk, -err); | |
914 | } | |
915 | } | |
916 | } else { | |
917 | /* Message not complete, save state */ | |
918 | partial_message: | |
cd27b96b WC |
919 | if (head) { |
920 | kcm->seq_skb = head; | |
921 | kcm_tx_msg(head)->last_skb = skb; | |
922 | } | |
ab7ac4eb TH |
923 | } |
924 | ||
cd6e111b TH |
925 | KCM_STATS_ADD(kcm->stats.tx_bytes, copied); |
926 | ||
ab7ac4eb TH |
927 | release_sock(sk); |
928 | return copied; | |
929 | ||
930 | out_error: | |
931 | kcm_push(kcm); | |
932 | ||
a22730b1 | 933 | if (sock->type == SOCK_SEQPACKET) { |
ab7ac4eb TH |
934 | /* Wrote some bytes before encountering an |
935 | * error, return partial success. | |
936 | */ | |
a22730b1 KI |
937 | if (copied) |
938 | goto partial_message; | |
939 | if (head != kcm->seq_skb) | |
940 | kfree_skb(head); | |
941 | } else { | |
ab7ac4eb | 942 | kfree_skb(head); |
a22730b1 KI |
943 | kcm->seq_skb = NULL; |
944 | } | |
ab7ac4eb TH |
945 | |
946 | err = sk_stream_error(sk, msg->msg_flags, err); | |
947 | ||
948 | /* make sure we wake any epoll edge trigger waiter */ | |
949 | if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) | |
950 | sk->sk_write_space(sk); | |
951 | ||
952 | release_sock(sk); | |
953 | return err; | |
954 | } | |
955 | ||
951ace99 DH |
956 | static void kcm_splice_eof(struct socket *sock) |
957 | { | |
958 | struct sock *sk = sock->sk; | |
959 | struct kcm_sock *kcm = kcm_sk(sk); | |
960 | ||
961 | if (skb_queue_empty_lockless(&sk->sk_write_queue)) | |
962 | return; | |
963 | ||
964 | lock_sock(sk); | |
965 | kcm_write_msgs(kcm); | |
966 | release_sock(sk); | |
967 | } | |
968 | ||
ab7ac4eb TH |
969 | static int kcm_recvmsg(struct socket *sock, struct msghdr *msg, |
970 | size_t len, int flags) | |
971 | { | |
972 | struct sock *sk = sock->sk; | |
cd6e111b | 973 | struct kcm_sock *kcm = kcm_sk(sk); |
ab7ac4eb | 974 | int err = 0; |
bbb03029 | 975 | struct strp_msg *stm; |
ab7ac4eb TH |
976 | int copied = 0; |
977 | struct sk_buff *skb; | |
978 | ||
5121197e | 979 | skb = skb_recv_datagram(sk, flags, &err); |
ab7ac4eb TH |
980 | if (!skb) |
981 | goto out; | |
982 | ||
983 | /* Okay, have a message on the receive queue */ | |
984 | ||
bbb03029 | 985 | stm = strp_msg(skb); |
ab7ac4eb | 986 | |
bbb03029 TH |
987 | if (len > stm->full_len) |
988 | len = stm->full_len; | |
ab7ac4eb | 989 | |
bbb03029 | 990 | err = skb_copy_datagram_msg(skb, stm->offset, msg, len); |
ab7ac4eb TH |
991 | if (err < 0) |
992 | goto out; | |
993 | ||
994 | copied = len; | |
995 | if (likely(!(flags & MSG_PEEK))) { | |
cd6e111b | 996 | KCM_STATS_ADD(kcm->stats.rx_bytes, copied); |
bbb03029 | 997 | if (copied < stm->full_len) { |
ab7ac4eb TH |
998 | if (sock->type == SOCK_DGRAM) { |
999 | /* Truncated message */ | |
1000 | msg->msg_flags |= MSG_TRUNC; | |
1001 | goto msg_finished; | |
1002 | } | |
bbb03029 TH |
1003 | stm->offset += copied; |
1004 | stm->full_len -= copied; | |
ab7ac4eb TH |
1005 | } else { |
1006 | msg_finished: | |
1007 | /* Finished with message */ | |
1008 | msg->msg_flags |= MSG_EOR; | |
cd6e111b | 1009 | KCM_STATS_INCR(kcm->stats.rx_msgs); |
ab7ac4eb TH |
1010 | } |
1011 | } | |
1012 | ||
1013 | out: | |
5121197e | 1014 | skb_free_datagram(sk, skb); |
ab7ac4eb TH |
1015 | return copied ? : err; |
1016 | } | |
1017 | ||
91687355 TH |
1018 | static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos, |
1019 | struct pipe_inode_info *pipe, size_t len, | |
1020 | unsigned int flags) | |
1021 | { | |
1022 | struct sock *sk = sock->sk; | |
1023 | struct kcm_sock *kcm = kcm_sk(sk); | |
bbb03029 | 1024 | struct strp_msg *stm; |
91687355 | 1025 | int err = 0; |
f1971a2e | 1026 | ssize_t copied; |
91687355 TH |
1027 | struct sk_buff *skb; |
1028 | ||
1029 | /* Only support splice for SOCKSEQPACKET */ | |
1030 | ||
5121197e | 1031 | skb = skb_recv_datagram(sk, flags, &err); |
91687355 TH |
1032 | if (!skb) |
1033 | goto err_out; | |
1034 | ||
1035 | /* Okay, have a message on the receive queue */ | |
1036 | ||
bbb03029 | 1037 | stm = strp_msg(skb); |
91687355 | 1038 | |
bbb03029 TH |
1039 | if (len > stm->full_len) |
1040 | len = stm->full_len; | |
91687355 | 1041 | |
bbb03029 | 1042 | copied = skb_splice_bits(skb, sk, stm->offset, pipe, len, flags); |
91687355 TH |
1043 | if (copied < 0) { |
1044 | err = copied; | |
1045 | goto err_out; | |
1046 | } | |
1047 | ||
1048 | KCM_STATS_ADD(kcm->stats.rx_bytes, copied); | |
1049 | ||
bbb03029 TH |
1050 | stm->offset += copied; |
1051 | stm->full_len -= copied; | |
91687355 TH |
1052 | |
1053 | /* We have no way to return MSG_EOR. If all the bytes have been | |
1054 | * read we still leave the message in the receive socket buffer. | |
1055 | * A subsequent recvmsg needs to be done to return MSG_EOR and | |
1056 | * finish reading the message. | |
1057 | */ | |
1058 | ||
5121197e | 1059 | skb_free_datagram(sk, skb); |
91687355 TH |
1060 | return copied; |
1061 | ||
1062 | err_out: | |
5121197e | 1063 | skb_free_datagram(sk, skb); |
91687355 TH |
1064 | return err; |
1065 | } | |
1066 | ||
ab7ac4eb TH |
1067 | /* kcm sock lock held */ |
1068 | static void kcm_recv_disable(struct kcm_sock *kcm) | |
1069 | { | |
1070 | struct kcm_mux *mux = kcm->mux; | |
1071 | ||
1072 | if (kcm->rx_disabled) | |
1073 | return; | |
1074 | ||
1075 | spin_lock_bh(&mux->rx_lock); | |
1076 | ||
1077 | kcm->rx_disabled = 1; | |
1078 | ||
1079 | /* If a psock is reserved we'll do cleanup in unreserve */ | |
1080 | if (!kcm->rx_psock) { | |
1081 | if (kcm->rx_wait) { | |
1082 | list_del(&kcm->wait_rx_list); | |
0c745b51 ED |
1083 | /* paired with lockless reads in kcm_rfree() */ |
1084 | WRITE_ONCE(kcm->rx_wait, false); | |
ab7ac4eb TH |
1085 | } |
1086 | ||
1087 | requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue); | |
1088 | } | |
1089 | ||
1090 | spin_unlock_bh(&mux->rx_lock); | |
1091 | } | |
1092 | ||
1093 | /* kcm sock lock held */ | |
1094 | static void kcm_recv_enable(struct kcm_sock *kcm) | |
1095 | { | |
1096 | struct kcm_mux *mux = kcm->mux; | |
1097 | ||
1098 | if (!kcm->rx_disabled) | |
1099 | return; | |
1100 | ||
1101 | spin_lock_bh(&mux->rx_lock); | |
1102 | ||
1103 | kcm->rx_disabled = 0; | |
1104 | kcm_rcv_ready(kcm); | |
1105 | ||
1106 | spin_unlock_bh(&mux->rx_lock); | |
1107 | } | |
1108 | ||
1109 | static int kcm_setsockopt(struct socket *sock, int level, int optname, | |
a7b75c5a | 1110 | sockptr_t optval, unsigned int optlen) |
ab7ac4eb TH |
1111 | { |
1112 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1113 | int val, valbool; | |
1114 | int err = 0; | |
1115 | ||
1116 | if (level != SOL_KCM) | |
1117 | return -ENOPROTOOPT; | |
1118 | ||
1119 | if (optlen < sizeof(int)) | |
1120 | return -EINVAL; | |
1121 | ||
a7b75c5a CH |
1122 | if (copy_from_sockptr(&val, optval, sizeof(int))) |
1123 | return -EFAULT; | |
ab7ac4eb TH |
1124 | |
1125 | valbool = val ? 1 : 0; | |
1126 | ||
1127 | switch (optname) { | |
1128 | case KCM_RECV_DISABLE: | |
1129 | lock_sock(&kcm->sk); | |
1130 | if (valbool) | |
1131 | kcm_recv_disable(kcm); | |
1132 | else | |
1133 | kcm_recv_enable(kcm); | |
1134 | release_sock(&kcm->sk); | |
1135 | break; | |
1136 | default: | |
1137 | err = -ENOPROTOOPT; | |
1138 | } | |
1139 | ||
1140 | return err; | |
1141 | } | |
1142 | ||
1143 | static int kcm_getsockopt(struct socket *sock, int level, int optname, | |
1144 | char __user *optval, int __user *optlen) | |
1145 | { | |
1146 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1147 | int val, len; | |
1148 | ||
1149 | if (level != SOL_KCM) | |
1150 | return -ENOPROTOOPT; | |
1151 | ||
1152 | if (get_user(len, optlen)) | |
1153 | return -EFAULT; | |
1154 | ||
1155 | len = min_t(unsigned int, len, sizeof(int)); | |
1156 | if (len < 0) | |
1157 | return -EINVAL; | |
1158 | ||
1159 | switch (optname) { | |
1160 | case KCM_RECV_DISABLE: | |
1161 | val = kcm->rx_disabled; | |
1162 | break; | |
1163 | default: | |
1164 | return -ENOPROTOOPT; | |
1165 | } | |
1166 | ||
1167 | if (put_user(len, optlen)) | |
1168 | return -EFAULT; | |
1169 | if (copy_to_user(optval, &val, len)) | |
1170 | return -EFAULT; | |
1171 | return 0; | |
1172 | } | |
1173 | ||
1174 | static void init_kcm_sock(struct kcm_sock *kcm, struct kcm_mux *mux) | |
1175 | { | |
1176 | struct kcm_sock *tkcm; | |
1177 | struct list_head *head; | |
1178 | int index = 0; | |
1179 | ||
a11e1d43 LT |
1180 | /* For SOCK_SEQPACKET sock type, datagram_poll checks the sk_state, so |
1181 | * we set sk_state, otherwise epoll_wait always returns right away with | |
1182 | * EPOLLHUP | |
ab7ac4eb TH |
1183 | */ |
1184 | kcm->sk.sk_state = TCP_ESTABLISHED; | |
1185 | ||
1186 | /* Add to mux's kcm sockets list */ | |
1187 | kcm->mux = mux; | |
1188 | spin_lock_bh(&mux->lock); | |
1189 | ||
1190 | head = &mux->kcm_socks; | |
1191 | list_for_each_entry(tkcm, &mux->kcm_socks, kcm_sock_list) { | |
1192 | if (tkcm->index != index) | |
1193 | break; | |
1194 | head = &tkcm->kcm_sock_list; | |
1195 | index++; | |
1196 | } | |
1197 | ||
1198 | list_add(&kcm->kcm_sock_list, head); | |
1199 | kcm->index = index; | |
1200 | ||
1201 | mux->kcm_socks_cnt++; | |
1202 | spin_unlock_bh(&mux->lock); | |
1203 | ||
1204 | INIT_WORK(&kcm->tx_work, kcm_tx_work); | |
1205 | ||
1206 | spin_lock_bh(&mux->rx_lock); | |
1207 | kcm_rcv_ready(kcm); | |
1208 | spin_unlock_bh(&mux->rx_lock); | |
1209 | } | |
1210 | ||
1211 | static int kcm_attach(struct socket *sock, struct socket *csock, | |
1212 | struct bpf_prog *prog) | |
1213 | { | |
1214 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1215 | struct kcm_mux *mux = kcm->mux; | |
1216 | struct sock *csk; | |
1217 | struct kcm_psock *psock = NULL, *tpsock; | |
1218 | struct list_head *head; | |
1219 | int index = 0; | |
3fd87127 EB |
1220 | static const struct strp_callbacks cb = { |
1221 | .rcv_msg = kcm_rcv_strparser, | |
1222 | .parse_msg = kcm_parse_func_strparser, | |
1223 | .read_sock_done = kcm_read_sock_done, | |
1224 | }; | |
2cc683e8 | 1225 | int err = 0; |
ab7ac4eb TH |
1226 | |
1227 | csk = csock->sk; | |
1228 | if (!csk) | |
1229 | return -EINVAL; | |
1230 | ||
2cc683e8 TH |
1231 | lock_sock(csk); |
1232 | ||
581e7226 TH |
1233 | /* Only allow TCP sockets to be attached for now */ |
1234 | if ((csk->sk_family != AF_INET && csk->sk_family != AF_INET6) || | |
2cc683e8 TH |
1235 | csk->sk_protocol != IPPROTO_TCP) { |
1236 | err = -EOPNOTSUPP; | |
1237 | goto out; | |
1238 | } | |
581e7226 TH |
1239 | |
1240 | /* Don't allow listeners or closed sockets */ | |
2cc683e8 TH |
1241 | if (csk->sk_state == TCP_LISTEN || csk->sk_state == TCP_CLOSE) { |
1242 | err = -EOPNOTSUPP; | |
1243 | goto out; | |
1244 | } | |
351050ec | 1245 | |
ab7ac4eb | 1246 | psock = kmem_cache_zalloc(kcm_psockp, GFP_KERNEL); |
2cc683e8 TH |
1247 | if (!psock) { |
1248 | err = -ENOMEM; | |
1249 | goto out; | |
1250 | } | |
ab7ac4eb TH |
1251 | |
1252 | psock->mux = mux; | |
1253 | psock->sk = csk; | |
1254 | psock->bpf_prog = prog; | |
29152a34 | 1255 | |
ab7ac4eb | 1256 | write_lock_bh(&csk->sk_callback_lock); |
e5571240 | 1257 | |
71a2fae5 | 1258 | /* Check if sk_user_data is already by KCM or someone else. |
e5571240 TH |
1259 | * Must be done under lock to prevent race conditions. |
1260 | */ | |
1261 | if (csk->sk_user_data) { | |
1262 | write_unlock_bh(&csk->sk_callback_lock); | |
e5571240 | 1263 | kmem_cache_free(kcm_psockp, psock); |
2cc683e8 TH |
1264 | err = -EALREADY; |
1265 | goto out; | |
e5571240 TH |
1266 | } |
1267 | ||
8fc29ff3 CW |
1268 | err = strp_init(&psock->strp, csk, &cb); |
1269 | if (err) { | |
1270 | write_unlock_bh(&csk->sk_callback_lock); | |
1271 | kmem_cache_free(kcm_psockp, psock); | |
1272 | goto out; | |
1273 | } | |
1274 | ||
ab7ac4eb TH |
1275 | psock->save_data_ready = csk->sk_data_ready; |
1276 | psock->save_write_space = csk->sk_write_space; | |
1277 | psock->save_state_change = csk->sk_state_change; | |
1278 | csk->sk_user_data = psock; | |
96a59083 TH |
1279 | csk->sk_data_ready = psock_data_ready; |
1280 | csk->sk_write_space = psock_write_space; | |
1281 | csk->sk_state_change = psock_state_change; | |
e5571240 | 1282 | |
ab7ac4eb TH |
1283 | write_unlock_bh(&csk->sk_callback_lock); |
1284 | ||
e5571240 TH |
1285 | sock_hold(csk); |
1286 | ||
ab7ac4eb TH |
1287 | /* Finished initialization, now add the psock to the MUX. */ |
1288 | spin_lock_bh(&mux->lock); | |
1289 | head = &mux->psocks; | |
1290 | list_for_each_entry(tpsock, &mux->psocks, psock_list) { | |
1291 | if (tpsock->index != index) | |
1292 | break; | |
1293 | head = &tpsock->psock_list; | |
1294 | index++; | |
1295 | } | |
1296 | ||
1297 | list_add(&psock->psock_list, head); | |
1298 | psock->index = index; | |
1299 | ||
cd6e111b | 1300 | KCM_STATS_INCR(mux->stats.psock_attach); |
ab7ac4eb TH |
1301 | mux->psocks_cnt++; |
1302 | psock_now_avail(psock); | |
1303 | spin_unlock_bh(&mux->lock); | |
1304 | ||
1305 | /* Schedule RX work in case there are already bytes queued */ | |
9b73896a | 1306 | strp_check_rcv(&psock->strp); |
ab7ac4eb | 1307 | |
2cc683e8 TH |
1308 | out: |
1309 | release_sock(csk); | |
1310 | ||
1311 | return err; | |
ab7ac4eb TH |
1312 | } |
1313 | ||
1314 | static int kcm_attach_ioctl(struct socket *sock, struct kcm_attach *info) | |
1315 | { | |
1316 | struct socket *csock; | |
1317 | struct bpf_prog *prog; | |
1318 | int err; | |
1319 | ||
1320 | csock = sockfd_lookup(info->fd, &err); | |
1321 | if (!csock) | |
1322 | return -ENOENT; | |
1323 | ||
113214be | 1324 | prog = bpf_prog_get_type(info->bpf_fd, BPF_PROG_TYPE_SOCKET_FILTER); |
ab7ac4eb TH |
1325 | if (IS_ERR(prog)) { |
1326 | err = PTR_ERR(prog); | |
1327 | goto out; | |
1328 | } | |
1329 | ||
ab7ac4eb TH |
1330 | err = kcm_attach(sock, csock, prog); |
1331 | if (err) { | |
1332 | bpf_prog_put(prog); | |
1333 | goto out; | |
1334 | } | |
1335 | ||
1336 | /* Keep reference on file also */ | |
1337 | ||
1338 | return 0; | |
1339 | out: | |
8dc879a1 | 1340 | sockfd_put(csock); |
ab7ac4eb TH |
1341 | return err; |
1342 | } | |
1343 | ||
1344 | static void kcm_unattach(struct kcm_psock *psock) | |
1345 | { | |
1346 | struct sock *csk = psock->sk; | |
1347 | struct kcm_mux *mux = psock->mux; | |
1348 | ||
1616b38f TH |
1349 | lock_sock(csk); |
1350 | ||
ab7ac4eb TH |
1351 | /* Stop getting callbacks from TCP socket. After this there should |
1352 | * be no way to reserve a kcm for this psock. | |
1353 | */ | |
1354 | write_lock_bh(&csk->sk_callback_lock); | |
1355 | csk->sk_user_data = NULL; | |
1356 | csk->sk_data_ready = psock->save_data_ready; | |
1357 | csk->sk_write_space = psock->save_write_space; | |
1358 | csk->sk_state_change = psock->save_state_change; | |
9b73896a | 1359 | strp_stop(&psock->strp); |
ab7ac4eb TH |
1360 | |
1361 | if (WARN_ON(psock->rx_kcm)) { | |
1362 | write_unlock_bh(&csk->sk_callback_lock); | |
2cc683e8 | 1363 | release_sock(csk); |
ab7ac4eb TH |
1364 | return; |
1365 | } | |
1366 | ||
1367 | spin_lock_bh(&mux->rx_lock); | |
1368 | ||
1369 | /* Stop receiver activities. After this point psock should not be | |
1370 | * able to get onto ready list either through callbacks or work. | |
1371 | */ | |
1372 | if (psock->ready_rx_msg) { | |
1373 | list_del(&psock->psock_ready_list); | |
1374 | kfree_skb(psock->ready_rx_msg); | |
1375 | psock->ready_rx_msg = NULL; | |
cd6e111b | 1376 | KCM_STATS_INCR(mux->stats.rx_ready_drops); |
ab7ac4eb TH |
1377 | } |
1378 | ||
1379 | spin_unlock_bh(&mux->rx_lock); | |
1380 | ||
1381 | write_unlock_bh(&csk->sk_callback_lock); | |
1382 | ||
1616b38f TH |
1383 | /* Call strp_done without sock lock */ |
1384 | release_sock(csk); | |
9b73896a | 1385 | strp_done(&psock->strp); |
1616b38f | 1386 | lock_sock(csk); |
ab7ac4eb TH |
1387 | |
1388 | bpf_prog_put(psock->bpf_prog); | |
1389 | ||
ab7ac4eb TH |
1390 | spin_lock_bh(&mux->lock); |
1391 | ||
cd6e111b | 1392 | aggregate_psock_stats(&psock->stats, &mux->aggregate_psock_stats); |
9b73896a | 1393 | save_strp_stats(&psock->strp, &mux->aggregate_strp_stats); |
cd6e111b TH |
1394 | |
1395 | KCM_STATS_INCR(mux->stats.psock_unattach); | |
1396 | ||
ab7ac4eb TH |
1397 | if (psock->tx_kcm) { |
1398 | /* psock was reserved. Just mark it finished and we will clean | |
1399 | * up in the kcm paths, we need kcm lock which can not be | |
1400 | * acquired here. | |
1401 | */ | |
cd6e111b | 1402 | KCM_STATS_INCR(mux->stats.psock_unattach_rsvd); |
ab7ac4eb TH |
1403 | spin_unlock_bh(&mux->lock); |
1404 | ||
1405 | /* We are unattaching a socket that is reserved. Abort the | |
1406 | * socket since we may be out of sync in sending on it. We need | |
1407 | * to do this without the mux lock. | |
1408 | */ | |
1409 | kcm_abort_tx_psock(psock, EPIPE, false); | |
1410 | ||
1411 | spin_lock_bh(&mux->lock); | |
1412 | if (!psock->tx_kcm) { | |
1413 | /* psock now unreserved in window mux was unlocked */ | |
1414 | goto no_reserved; | |
1415 | } | |
1416 | psock->done = 1; | |
1417 | ||
1418 | /* Commit done before queuing work to process it */ | |
1419 | smp_mb(); | |
1420 | ||
1421 | /* Queue tx work to make sure psock->done is handled */ | |
1422 | queue_work(kcm_wq, &psock->tx_kcm->tx_work); | |
1423 | spin_unlock_bh(&mux->lock); | |
1424 | } else { | |
1425 | no_reserved: | |
1426 | if (!psock->tx_stopped) | |
1427 | list_del(&psock->psock_avail_list); | |
1428 | list_del(&psock->psock_list); | |
1429 | mux->psocks_cnt--; | |
1430 | spin_unlock_bh(&mux->lock); | |
1431 | ||
1432 | sock_put(csk); | |
1433 | fput(csk->sk_socket->file); | |
1434 | kmem_cache_free(kcm_psockp, psock); | |
1435 | } | |
1616b38f TH |
1436 | |
1437 | release_sock(csk); | |
ab7ac4eb TH |
1438 | } |
1439 | ||
1440 | static int kcm_unattach_ioctl(struct socket *sock, struct kcm_unattach *info) | |
1441 | { | |
1442 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1443 | struct kcm_mux *mux = kcm->mux; | |
1444 | struct kcm_psock *psock; | |
1445 | struct socket *csock; | |
1446 | struct sock *csk; | |
1447 | int err; | |
1448 | ||
1449 | csock = sockfd_lookup(info->fd, &err); | |
1450 | if (!csock) | |
1451 | return -ENOENT; | |
1452 | ||
1453 | csk = csock->sk; | |
1454 | if (!csk) { | |
1455 | err = -EINVAL; | |
1456 | goto out; | |
1457 | } | |
1458 | ||
1459 | err = -ENOENT; | |
1460 | ||
1461 | spin_lock_bh(&mux->lock); | |
1462 | ||
1463 | list_for_each_entry(psock, &mux->psocks, psock_list) { | |
1464 | if (psock->sk != csk) | |
1465 | continue; | |
1466 | ||
1467 | /* Found the matching psock */ | |
1468 | ||
1469 | if (psock->unattaching || WARN_ON(psock->done)) { | |
1470 | err = -EALREADY; | |
1471 | break; | |
1472 | } | |
1473 | ||
1474 | psock->unattaching = 1; | |
1475 | ||
1476 | spin_unlock_bh(&mux->lock); | |
1477 | ||
9b73896a | 1478 | /* Lower socket lock should already be held */ |
ab7ac4eb TH |
1479 | kcm_unattach(psock); |
1480 | ||
1481 | err = 0; | |
1482 | goto out; | |
1483 | } | |
1484 | ||
1485 | spin_unlock_bh(&mux->lock); | |
1486 | ||
1487 | out: | |
8dc879a1 | 1488 | sockfd_put(csock); |
ab7ac4eb TH |
1489 | return err; |
1490 | } | |
1491 | ||
1492 | static struct proto kcm_proto = { | |
1493 | .name = "KCM", | |
1494 | .owner = THIS_MODULE, | |
1495 | .obj_size = sizeof(struct kcm_sock), | |
1496 | }; | |
1497 | ||
1498 | /* Clone a kcm socket. */ | |
a5739435 | 1499 | static struct file *kcm_clone(struct socket *osock) |
ab7ac4eb TH |
1500 | { |
1501 | struct socket *newsock; | |
1502 | struct sock *newsk; | |
ab7ac4eb | 1503 | |
ab7ac4eb TH |
1504 | newsock = sock_alloc(); |
1505 | if (!newsock) | |
a5739435 | 1506 | return ERR_PTR(-ENFILE); |
ab7ac4eb TH |
1507 | |
1508 | newsock->type = osock->type; | |
1509 | newsock->ops = osock->ops; | |
1510 | ||
1511 | __module_get(newsock->ops->owner); | |
1512 | ||
ab7ac4eb | 1513 | newsk = sk_alloc(sock_net(osock->sk), PF_KCM, GFP_KERNEL, |
eb7f54b9 | 1514 | &kcm_proto, false); |
ab7ac4eb | 1515 | if (!newsk) { |
a5739435 AV |
1516 | sock_release(newsock); |
1517 | return ERR_PTR(-ENOMEM); | |
ab7ac4eb | 1518 | } |
ab7ac4eb TH |
1519 | sock_init_data(newsock, newsk); |
1520 | init_kcm_sock(kcm_sk(newsk), kcm_sk(osock->sk)->mux); | |
1521 | ||
8e1611e2 | 1522 | return sock_alloc_file(newsock, 0, osock->sk->sk_prot_creator->name); |
ab7ac4eb TH |
1523 | } |
1524 | ||
1525 | static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) | |
1526 | { | |
1527 | int err; | |
1528 | ||
1529 | switch (cmd) { | |
1530 | case SIOCKCMATTACH: { | |
1531 | struct kcm_attach info; | |
1532 | ||
1533 | if (copy_from_user(&info, (void __user *)arg, sizeof(info))) | |
a80db69e | 1534 | return -EFAULT; |
ab7ac4eb TH |
1535 | |
1536 | err = kcm_attach_ioctl(sock, &info); | |
1537 | ||
1538 | break; | |
1539 | } | |
1540 | case SIOCKCMUNATTACH: { | |
1541 | struct kcm_unattach info; | |
1542 | ||
1543 | if (copy_from_user(&info, (void __user *)arg, sizeof(info))) | |
a80db69e | 1544 | return -EFAULT; |
ab7ac4eb TH |
1545 | |
1546 | err = kcm_unattach_ioctl(sock, &info); | |
1547 | ||
1548 | break; | |
1549 | } | |
1550 | case SIOCKCMCLONE: { | |
1551 | struct kcm_clone info; | |
a5739435 AV |
1552 | struct file *file; |
1553 | ||
1554 | info.fd = get_unused_fd_flags(0); | |
1555 | if (unlikely(info.fd < 0)) | |
1556 | return info.fd; | |
ab7ac4eb | 1557 | |
a5739435 AV |
1558 | file = kcm_clone(sock); |
1559 | if (IS_ERR(file)) { | |
1560 | put_unused_fd(info.fd); | |
1561 | return PTR_ERR(file); | |
1562 | } | |
1563 | if (copy_to_user((void __user *)arg, &info, | |
1564 | sizeof(info))) { | |
1565 | put_unused_fd(info.fd); | |
1566 | fput(file); | |
1567 | return -EFAULT; | |
1568 | } | |
1569 | fd_install(info.fd, file); | |
1570 | err = 0; | |
ab7ac4eb TH |
1571 | break; |
1572 | } | |
1573 | default: | |
1574 | err = -ENOIOCTLCMD; | |
1575 | break; | |
1576 | } | |
1577 | ||
1578 | return err; | |
1579 | } | |
1580 | ||
1581 | static void free_mux(struct rcu_head *rcu) | |
1582 | { | |
1583 | struct kcm_mux *mux = container_of(rcu, | |
1584 | struct kcm_mux, rcu); | |
1585 | ||
1586 | kmem_cache_free(kcm_muxp, mux); | |
1587 | } | |
1588 | ||
1589 | static void release_mux(struct kcm_mux *mux) | |
1590 | { | |
1591 | struct kcm_net *knet = mux->knet; | |
1592 | struct kcm_psock *psock, *tmp_psock; | |
1593 | ||
1594 | /* Release psocks */ | |
1595 | list_for_each_entry_safe(psock, tmp_psock, | |
1596 | &mux->psocks, psock_list) { | |
1616b38f | 1597 | if (!WARN_ON(psock->unattaching)) |
ab7ac4eb TH |
1598 | kcm_unattach(psock); |
1599 | } | |
1600 | ||
1601 | if (WARN_ON(mux->psocks_cnt)) | |
1602 | return; | |
1603 | ||
1604 | __skb_queue_purge(&mux->rx_hold_queue); | |
1605 | ||
1606 | mutex_lock(&knet->mutex); | |
cd6e111b TH |
1607 | aggregate_mux_stats(&mux->stats, &knet->aggregate_mux_stats); |
1608 | aggregate_psock_stats(&mux->aggregate_psock_stats, | |
1609 | &knet->aggregate_psock_stats); | |
9b73896a TH |
1610 | aggregate_strp_stats(&mux->aggregate_strp_stats, |
1611 | &knet->aggregate_strp_stats); | |
ab7ac4eb TH |
1612 | list_del_rcu(&mux->kcm_mux_list); |
1613 | knet->count--; | |
1614 | mutex_unlock(&knet->mutex); | |
1615 | ||
1616 | call_rcu(&mux->rcu, free_mux); | |
1617 | } | |
1618 | ||
1619 | static void kcm_done(struct kcm_sock *kcm) | |
1620 | { | |
1621 | struct kcm_mux *mux = kcm->mux; | |
1622 | struct sock *sk = &kcm->sk; | |
1623 | int socks_cnt; | |
1624 | ||
1625 | spin_lock_bh(&mux->rx_lock); | |
1626 | if (kcm->rx_psock) { | |
1627 | /* Cleanup in unreserve_rx_kcm */ | |
1628 | WARN_ON(kcm->done); | |
1629 | kcm->rx_disabled = 1; | |
1630 | kcm->done = 1; | |
1631 | spin_unlock_bh(&mux->rx_lock); | |
1632 | return; | |
1633 | } | |
1634 | ||
1635 | if (kcm->rx_wait) { | |
1636 | list_del(&kcm->wait_rx_list); | |
0c745b51 ED |
1637 | /* paired with lockless reads in kcm_rfree() */ |
1638 | WRITE_ONCE(kcm->rx_wait, false); | |
ab7ac4eb TH |
1639 | } |
1640 | /* Move any pending receive messages to other kcm sockets */ | |
1641 | requeue_rx_msgs(mux, &sk->sk_receive_queue); | |
1642 | ||
1643 | spin_unlock_bh(&mux->rx_lock); | |
1644 | ||
1645 | if (WARN_ON(sk_rmem_alloc_get(sk))) | |
1646 | return; | |
1647 | ||
1648 | /* Detach from MUX */ | |
1649 | spin_lock_bh(&mux->lock); | |
1650 | ||
1651 | list_del(&kcm->kcm_sock_list); | |
1652 | mux->kcm_socks_cnt--; | |
1653 | socks_cnt = mux->kcm_socks_cnt; | |
1654 | ||
1655 | spin_unlock_bh(&mux->lock); | |
1656 | ||
1657 | if (!socks_cnt) { | |
1658 | /* We are done with the mux now. */ | |
1659 | release_mux(mux); | |
1660 | } | |
1661 | ||
1662 | WARN_ON(kcm->rx_wait); | |
1663 | ||
1664 | sock_put(&kcm->sk); | |
1665 | } | |
1666 | ||
1667 | /* Called by kcm_release to close a KCM socket. | |
1668 | * If this is the last KCM socket on the MUX, destroy the MUX. | |
1669 | */ | |
1670 | static int kcm_release(struct socket *sock) | |
1671 | { | |
1672 | struct sock *sk = sock->sk; | |
1673 | struct kcm_sock *kcm; | |
1674 | struct kcm_mux *mux; | |
1675 | struct kcm_psock *psock; | |
1676 | ||
1677 | if (!sk) | |
1678 | return 0; | |
1679 | ||
1680 | kcm = kcm_sk(sk); | |
1681 | mux = kcm->mux; | |
1682 | ||
ec7eede3 | 1683 | lock_sock(sk); |
ab7ac4eb TH |
1684 | sock_orphan(sk); |
1685 | kfree_skb(kcm->seq_skb); | |
1686 | ||
ab7ac4eb TH |
1687 | /* Purge queue under lock to avoid race condition with tx_work trying |
1688 | * to act when queue is nonempty. If tx_work runs after this point | |
1689 | * it will just return. | |
1690 | */ | |
1691 | __skb_queue_purge(&sk->sk_write_queue); | |
9b73896a TH |
1692 | |
1693 | /* Set tx_stopped. This is checked when psock is bound to a kcm and we | |
1694 | * get a writespace callback. This prevents further work being queued | |
1695 | * from the callback (unbinding the psock occurs after canceling work. | |
1696 | */ | |
1697 | kcm->tx_stopped = 1; | |
1698 | ||
ab7ac4eb TH |
1699 | release_sock(sk); |
1700 | ||
1701 | spin_lock_bh(&mux->lock); | |
1702 | if (kcm->tx_wait) { | |
1703 | /* Take of tx_wait list, after this point there should be no way | |
1704 | * that a psock will be assigned to this kcm. | |
1705 | */ | |
1706 | list_del(&kcm->wait_psock_list); | |
1707 | kcm->tx_wait = false; | |
1708 | } | |
1709 | spin_unlock_bh(&mux->lock); | |
1710 | ||
1711 | /* Cancel work. After this point there should be no outside references | |
1712 | * to the kcm socket. | |
1713 | */ | |
1714 | cancel_work_sync(&kcm->tx_work); | |
1715 | ||
1716 | lock_sock(sk); | |
1717 | psock = kcm->tx_psock; | |
1718 | if (psock) { | |
1719 | /* A psock was reserved, so we need to kill it since it | |
1720 | * may already have some bytes queued from a message. We | |
1721 | * need to do this after removing kcm from tx_wait list. | |
1722 | */ | |
1723 | kcm_abort_tx_psock(psock, EPIPE, false); | |
1724 | unreserve_psock(kcm); | |
1725 | } | |
1726 | release_sock(sk); | |
1727 | ||
1728 | WARN_ON(kcm->tx_wait); | |
1729 | WARN_ON(kcm->tx_psock); | |
1730 | ||
1731 | sock->sk = NULL; | |
1732 | ||
1733 | kcm_done(kcm); | |
1734 | ||
1735 | return 0; | |
1736 | } | |
1737 | ||
91687355 | 1738 | static const struct proto_ops kcm_dgram_ops = { |
ab7ac4eb TH |
1739 | .family = PF_KCM, |
1740 | .owner = THIS_MODULE, | |
1741 | .release = kcm_release, | |
1742 | .bind = sock_no_bind, | |
1743 | .connect = sock_no_connect, | |
1744 | .socketpair = sock_no_socketpair, | |
1745 | .accept = sock_no_accept, | |
1746 | .getname = sock_no_getname, | |
a11e1d43 | 1747 | .poll = datagram_poll, |
ab7ac4eb TH |
1748 | .ioctl = kcm_ioctl, |
1749 | .listen = sock_no_listen, | |
1750 | .shutdown = sock_no_shutdown, | |
1751 | .setsockopt = kcm_setsockopt, | |
1752 | .getsockopt = kcm_getsockopt, | |
1753 | .sendmsg = kcm_sendmsg, | |
1754 | .recvmsg = kcm_recvmsg, | |
1755 | .mmap = sock_no_mmap, | |
951ace99 | 1756 | .splice_eof = kcm_splice_eof, |
ab7ac4eb TH |
1757 | }; |
1758 | ||
91687355 TH |
1759 | static const struct proto_ops kcm_seqpacket_ops = { |
1760 | .family = PF_KCM, | |
1761 | .owner = THIS_MODULE, | |
1762 | .release = kcm_release, | |
1763 | .bind = sock_no_bind, | |
1764 | .connect = sock_no_connect, | |
1765 | .socketpair = sock_no_socketpair, | |
1766 | .accept = sock_no_accept, | |
1767 | .getname = sock_no_getname, | |
a11e1d43 | 1768 | .poll = datagram_poll, |
91687355 TH |
1769 | .ioctl = kcm_ioctl, |
1770 | .listen = sock_no_listen, | |
1771 | .shutdown = sock_no_shutdown, | |
1772 | .setsockopt = kcm_setsockopt, | |
1773 | .getsockopt = kcm_getsockopt, | |
1774 | .sendmsg = kcm_sendmsg, | |
1775 | .recvmsg = kcm_recvmsg, | |
1776 | .mmap = sock_no_mmap, | |
951ace99 | 1777 | .splice_eof = kcm_splice_eof, |
91687355 TH |
1778 | .splice_read = kcm_splice_read, |
1779 | }; | |
1780 | ||
ab7ac4eb TH |
1781 | /* Create proto operation for kcm sockets */ |
1782 | static int kcm_create(struct net *net, struct socket *sock, | |
1783 | int protocol, int kern) | |
1784 | { | |
1785 | struct kcm_net *knet = net_generic(net, kcm_net_id); | |
1786 | struct sock *sk; | |
1787 | struct kcm_mux *mux; | |
1788 | ||
1789 | switch (sock->type) { | |
1790 | case SOCK_DGRAM: | |
91687355 TH |
1791 | sock->ops = &kcm_dgram_ops; |
1792 | break; | |
ab7ac4eb | 1793 | case SOCK_SEQPACKET: |
91687355 | 1794 | sock->ops = &kcm_seqpacket_ops; |
ab7ac4eb TH |
1795 | break; |
1796 | default: | |
1797 | return -ESOCKTNOSUPPORT; | |
1798 | } | |
1799 | ||
1800 | if (protocol != KCMPROTO_CONNECTED) | |
1801 | return -EPROTONOSUPPORT; | |
1802 | ||
1803 | sk = sk_alloc(net, PF_KCM, GFP_KERNEL, &kcm_proto, kern); | |
1804 | if (!sk) | |
1805 | return -ENOMEM; | |
1806 | ||
1807 | /* Allocate a kcm mux, shared between KCM sockets */ | |
1808 | mux = kmem_cache_zalloc(kcm_muxp, GFP_KERNEL); | |
1809 | if (!mux) { | |
1810 | sk_free(sk); | |
1811 | return -ENOMEM; | |
1812 | } | |
1813 | ||
1814 | spin_lock_init(&mux->lock); | |
1815 | spin_lock_init(&mux->rx_lock); | |
1816 | INIT_LIST_HEAD(&mux->kcm_socks); | |
1817 | INIT_LIST_HEAD(&mux->kcm_rx_waiters); | |
1818 | INIT_LIST_HEAD(&mux->kcm_tx_waiters); | |
1819 | ||
1820 | INIT_LIST_HEAD(&mux->psocks); | |
1821 | INIT_LIST_HEAD(&mux->psocks_ready); | |
1822 | INIT_LIST_HEAD(&mux->psocks_avail); | |
1823 | ||
1824 | mux->knet = knet; | |
1825 | ||
1826 | /* Add new MUX to list */ | |
1827 | mutex_lock(&knet->mutex); | |
1828 | list_add_rcu(&mux->kcm_mux_list, &knet->mux_list); | |
1829 | knet->count++; | |
1830 | mutex_unlock(&knet->mutex); | |
1831 | ||
1832 | skb_queue_head_init(&mux->rx_hold_queue); | |
1833 | ||
1834 | /* Init KCM socket */ | |
1835 | sock_init_data(sock, sk); | |
1836 | init_kcm_sock(kcm_sk(sk), mux); | |
1837 | ||
1838 | return 0; | |
1839 | } | |
1840 | ||
173e7837 | 1841 | static const struct net_proto_family kcm_family_ops = { |
ab7ac4eb TH |
1842 | .family = PF_KCM, |
1843 | .create = kcm_create, | |
1844 | .owner = THIS_MODULE, | |
1845 | }; | |
1846 | ||
1847 | static __net_init int kcm_init_net(struct net *net) | |
1848 | { | |
1849 | struct kcm_net *knet = net_generic(net, kcm_net_id); | |
1850 | ||
1851 | INIT_LIST_HEAD_RCU(&knet->mux_list); | |
1852 | mutex_init(&knet->mutex); | |
1853 | ||
1854 | return 0; | |
1855 | } | |
1856 | ||
1857 | static __net_exit void kcm_exit_net(struct net *net) | |
1858 | { | |
1859 | struct kcm_net *knet = net_generic(net, kcm_net_id); | |
1860 | ||
1861 | /* All KCM sockets should be closed at this point, which should mean | |
1862 | * that all multiplexors and psocks have been destroyed. | |
1863 | */ | |
1864 | WARN_ON(!list_empty(&knet->mux_list)); | |
6ad40b36 SY |
1865 | |
1866 | mutex_destroy(&knet->mutex); | |
ab7ac4eb TH |
1867 | } |
1868 | ||
1869 | static struct pernet_operations kcm_net_ops = { | |
1870 | .init = kcm_init_net, | |
1871 | .exit = kcm_exit_net, | |
1872 | .id = &kcm_net_id, | |
1873 | .size = sizeof(struct kcm_net), | |
1874 | }; | |
1875 | ||
1876 | static int __init kcm_init(void) | |
1877 | { | |
1878 | int err = -ENOMEM; | |
1879 | ||
1880 | kcm_muxp = kmem_cache_create("kcm_mux_cache", | |
1881 | sizeof(struct kcm_mux), 0, | |
c2115240 | 1882 | SLAB_HWCACHE_ALIGN, NULL); |
ab7ac4eb TH |
1883 | if (!kcm_muxp) |
1884 | goto fail; | |
1885 | ||
1886 | kcm_psockp = kmem_cache_create("kcm_psock_cache", | |
1887 | sizeof(struct kcm_psock), 0, | |
c2115240 | 1888 | SLAB_HWCACHE_ALIGN, NULL); |
ab7ac4eb TH |
1889 | if (!kcm_psockp) |
1890 | goto fail; | |
1891 | ||
1892 | kcm_wq = create_singlethread_workqueue("kkcmd"); | |
1893 | if (!kcm_wq) | |
1894 | goto fail; | |
1895 | ||
1896 | err = proto_register(&kcm_proto, 1); | |
1897 | if (err) | |
1898 | goto fail; | |
1899 | ||
ab7ac4eb TH |
1900 | err = register_pernet_device(&kcm_net_ops); |
1901 | if (err) | |
1902 | goto net_ops_fail; | |
1903 | ||
3c446e6f JS |
1904 | err = sock_register(&kcm_family_ops); |
1905 | if (err) | |
1906 | goto sock_register_fail; | |
1907 | ||
cd6e111b TH |
1908 | err = kcm_proc_init(); |
1909 | if (err) | |
1910 | goto proc_init_fail; | |
1911 | ||
ab7ac4eb TH |
1912 | return 0; |
1913 | ||
cd6e111b | 1914 | proc_init_fail: |
ab7ac4eb TH |
1915 | sock_unregister(PF_KCM); |
1916 | ||
1917 | sock_register_fail: | |
3c446e6f JS |
1918 | unregister_pernet_device(&kcm_net_ops); |
1919 | ||
1920 | net_ops_fail: | |
ab7ac4eb TH |
1921 | proto_unregister(&kcm_proto); |
1922 | ||
1923 | fail: | |
1924 | kmem_cache_destroy(kcm_muxp); | |
1925 | kmem_cache_destroy(kcm_psockp); | |
1926 | ||
1927 | if (kcm_wq) | |
1928 | destroy_workqueue(kcm_wq); | |
1929 | ||
1930 | return err; | |
1931 | } | |
1932 | ||
1933 | static void __exit kcm_exit(void) | |
1934 | { | |
cd6e111b | 1935 | kcm_proc_exit(); |
ab7ac4eb | 1936 | sock_unregister(PF_KCM); |
3c446e6f | 1937 | unregister_pernet_device(&kcm_net_ops); |
ab7ac4eb TH |
1938 | proto_unregister(&kcm_proto); |
1939 | destroy_workqueue(kcm_wq); | |
1940 | ||
1941 | kmem_cache_destroy(kcm_muxp); | |
1942 | kmem_cache_destroy(kcm_psockp); | |
1943 | } | |
1944 | ||
1945 | module_init(kcm_init); | |
1946 | module_exit(kcm_exit); | |
1947 | ||
1948 | MODULE_LICENSE("GPL"); | |
1949 | MODULE_ALIAS_NETPROTO(PF_KCM); |