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 | |
21d2e673 MA |
630 | if (WARN_ON(!skb_shinfo(skb)->nr_frags) || |
631 | WARN_ON_ONCE(!skb_frag_page(&skb_shinfo(skb)->frags[0]))) { | |
ab7ac4eb TH |
632 | ret = -EINVAL; |
633 | goto out; | |
634 | } | |
635 | ||
c31a25e1 DH |
636 | msize = 0; |
637 | for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) | |
b15a4cfe | 638 | msize += skb_frag_size(&skb_shinfo(skb)->frags[i]); |
c31a25e1 DH |
639 | |
640 | iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, | |
21d2e673 MA |
641 | (const struct bio_vec *)skb_shinfo(skb)->frags, |
642 | skb_shinfo(skb)->nr_frags, msize); | |
c31a25e1 | 643 | iov_iter_advance(&msg.msg_iter, txm->frag_offset); |
ab7ac4eb | 644 | |
c31a25e1 | 645 | do { |
264ba53f | 646 | ret = sock_sendmsg(psock->sk->sk_socket, &msg); |
ab7ac4eb TH |
647 | if (ret <= 0) { |
648 | if (ret == -EAGAIN) { | |
649 | /* Save state to try again when there's | |
650 | * write space on the socket | |
651 | */ | |
ab7ac4eb | 652 | txm->frag_skb = skb; |
ab7ac4eb TH |
653 | ret = 0; |
654 | goto out; | |
655 | } | |
656 | ||
657 | /* Hard failure in sending message, abort this | |
658 | * psock since it has lost framing | |
71a2fae5 | 659 | * synchronization and retry sending the |
ab7ac4eb TH |
660 | * message from the beginning. |
661 | */ | |
662 | kcm_abort_tx_psock(psock, ret ? -ret : EPIPE, | |
663 | true); | |
664 | unreserve_psock(kcm); | |
9f8d0dc0 | 665 | psock = NULL; |
ab7ac4eb | 666 | |
c31a25e1 | 667 | txm->started_tx = false; |
cd6e111b | 668 | kcm_report_tx_retry(kcm); |
ab7ac4eb | 669 | ret = 0; |
c31a25e1 | 670 | goto retry; |
ab7ac4eb TH |
671 | } |
672 | ||
c31a25e1 DH |
673 | txm->sent += ret; |
674 | txm->frag_offset += ret; | |
cd6e111b | 675 | KCM_STATS_ADD(psock->stats.tx_bytes, ret); |
c31a25e1 | 676 | } while (msg.msg_iter.count > 0); |
ab7ac4eb TH |
677 | |
678 | if (skb == head) { | |
679 | if (skb_has_frag_list(skb)) { | |
c31a25e1 DH |
680 | txm->frag_skb = skb_shinfo(skb)->frag_list; |
681 | txm->frag_offset = 0; | |
682 | continue; | |
ab7ac4eb TH |
683 | } |
684 | } else if (skb->next) { | |
c31a25e1 DH |
685 | txm->frag_skb = skb->next; |
686 | txm->frag_offset = 0; | |
687 | continue; | |
ab7ac4eb TH |
688 | } |
689 | ||
690 | /* Successfully sent the whole packet, account for it. */ | |
c31a25e1 DH |
691 | sk->sk_wmem_queued -= txm->sent; |
692 | total_sent += txm->sent; | |
ab7ac4eb TH |
693 | skb_dequeue(&sk->sk_write_queue); |
694 | kfree_skb(head); | |
cd6e111b | 695 | KCM_STATS_INCR(psock->stats.tx_msgs); |
c31a25e1 | 696 | } |
ab7ac4eb TH |
697 | out: |
698 | if (!head) { | |
699 | /* Done with all queued messages. */ | |
700 | WARN_ON(!skb_queue_empty(&sk->sk_write_queue)); | |
9f8d0dc0 DH |
701 | if (psock) |
702 | unreserve_psock(kcm); | |
ab7ac4eb TH |
703 | } |
704 | ||
705 | /* Check if write space is available */ | |
706 | sk->sk_write_space(sk); | |
707 | ||
708 | return total_sent ? : ret; | |
709 | } | |
710 | ||
711 | static void kcm_tx_work(struct work_struct *w) | |
712 | { | |
713 | struct kcm_sock *kcm = container_of(w, struct kcm_sock, tx_work); | |
714 | struct sock *sk = &kcm->sk; | |
715 | int err; | |
716 | ||
717 | lock_sock(sk); | |
718 | ||
719 | /* Primarily for SOCK_DGRAM sockets, also handle asynchronous tx | |
720 | * aborts | |
721 | */ | |
722 | err = kcm_write_msgs(kcm); | |
723 | if (err < 0) { | |
724 | /* Hard failure in write, report error on KCM socket */ | |
725 | pr_warn("KCM: Hard failure on kcm_write_msgs %d\n", err); | |
726 | report_csk_error(&kcm->sk, -err); | |
727 | goto out; | |
728 | } | |
729 | ||
730 | /* Primarily for SOCK_SEQPACKET sockets */ | |
731 | if (likely(sk->sk_socket) && | |
732 | test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { | |
733 | clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
734 | sk->sk_write_space(sk); | |
735 | } | |
736 | ||
737 | out: | |
738 | release_sock(sk); | |
739 | } | |
740 | ||
741 | static void kcm_push(struct kcm_sock *kcm) | |
742 | { | |
743 | if (kcm->tx_wait_more) | |
744 | kcm_write_msgs(kcm); | |
745 | } | |
746 | ||
747 | static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) | |
748 | { | |
749 | struct sock *sk = sock->sk; | |
750 | struct kcm_sock *kcm = kcm_sk(sk); | |
751 | struct sk_buff *skb = NULL, *head = NULL; | |
752 | size_t copy, copied = 0; | |
753 | long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
754 | int eor = (sock->type == SOCK_DGRAM) ? | |
755 | !(msg->msg_flags & MSG_MORE) : !!(msg->msg_flags & MSG_EOR); | |
756 | int err = -EPIPE; | |
757 | ||
758 | lock_sock(sk); | |
759 | ||
760 | /* Per tcp_sendmsg this should be in poll */ | |
761 | sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); | |
762 | ||
763 | if (sk->sk_err) | |
764 | goto out_error; | |
765 | ||
766 | if (kcm->seq_skb) { | |
767 | /* Previously opened message */ | |
768 | head = kcm->seq_skb; | |
769 | skb = kcm_tx_msg(head)->last_skb; | |
770 | goto start; | |
771 | } | |
772 | ||
773 | /* Call the sk_stream functions to manage the sndbuf mem. */ | |
774 | if (!sk_stream_memory_free(sk)) { | |
775 | kcm_push(kcm); | |
776 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
777 | err = sk_stream_wait_memory(sk, &timeo); | |
778 | if (err) | |
779 | goto out_error; | |
780 | } | |
781 | ||
98e3862c WC |
782 | if (msg_data_left(msg)) { |
783 | /* New message, alloc head skb */ | |
ab7ac4eb | 784 | head = alloc_skb(0, sk->sk_allocation); |
98e3862c WC |
785 | while (!head) { |
786 | kcm_push(kcm); | |
787 | err = sk_stream_wait_memory(sk, &timeo); | |
788 | if (err) | |
789 | goto out_error; | |
ab7ac4eb | 790 | |
98e3862c WC |
791 | head = alloc_skb(0, sk->sk_allocation); |
792 | } | |
ab7ac4eb | 793 | |
98e3862c WC |
794 | skb = head; |
795 | ||
796 | /* Set ip_summed to CHECKSUM_UNNECESSARY to avoid calling | |
797 | * csum_and_copy_from_iter from skb_do_copy_data_nocache. | |
798 | */ | |
799 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
800 | } | |
ab7ac4eb TH |
801 | |
802 | start: | |
803 | while (msg_data_left(msg)) { | |
804 | bool merge = true; | |
805 | int i = skb_shinfo(skb)->nr_frags; | |
806 | struct page_frag *pfrag = sk_page_frag(sk); | |
807 | ||
808 | if (!sk_page_frag_refill(sk, pfrag)) | |
809 | goto wait_for_memory; | |
810 | ||
811 | if (!skb_can_coalesce(skb, i, pfrag->page, | |
812 | pfrag->offset)) { | |
813 | if (i == MAX_SKB_FRAGS) { | |
814 | struct sk_buff *tskb; | |
815 | ||
816 | tskb = alloc_skb(0, sk->sk_allocation); | |
817 | if (!tskb) | |
818 | goto wait_for_memory; | |
819 | ||
820 | if (head == skb) | |
821 | skb_shinfo(head)->frag_list = tskb; | |
822 | else | |
823 | skb->next = tskb; | |
824 | ||
825 | skb = tskb; | |
826 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
827 | continue; | |
828 | } | |
829 | merge = false; | |
830 | } | |
831 | ||
2b03bcae DH |
832 | if (msg->msg_flags & MSG_SPLICE_PAGES) { |
833 | copy = msg_data_left(msg); | |
834 | if (!sk_wmem_schedule(sk, copy)) | |
835 | goto wait_for_memory; | |
ab7ac4eb | 836 | |
2b03bcae DH |
837 | err = skb_splice_from_iter(skb, &msg->msg_iter, copy, |
838 | sk->sk_allocation); | |
839 | if (err < 0) { | |
840 | if (err == -EMSGSIZE) | |
841 | goto wait_for_memory; | |
842 | goto out_error; | |
843 | } | |
ab7ac4eb | 844 | |
2b03bcae DH |
845 | copy = err; |
846 | skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG; | |
847 | sk_wmem_queued_add(sk, copy); | |
848 | sk_mem_charge(sk, copy); | |
ab7ac4eb | 849 | |
2b03bcae DH |
850 | if (head != skb) |
851 | head->truesize += copy; | |
ab7ac4eb | 852 | } else { |
2b03bcae DH |
853 | copy = min_t(int, msg_data_left(msg), |
854 | pfrag->size - pfrag->offset); | |
855 | if (!sk_wmem_schedule(sk, copy)) | |
856 | goto wait_for_memory; | |
857 | ||
858 | err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb, | |
859 | pfrag->page, | |
860 | pfrag->offset, | |
861 | copy); | |
862 | if (err) | |
863 | goto out_error; | |
864 | ||
865 | /* Update the skb. */ | |
866 | if (merge) { | |
867 | skb_frag_size_add( | |
868 | &skb_shinfo(skb)->frags[i - 1], copy); | |
869 | } else { | |
870 | skb_fill_page_desc(skb, i, pfrag->page, | |
871 | pfrag->offset, copy); | |
872 | get_page(pfrag->page); | |
873 | } | |
874 | ||
875 | pfrag->offset += copy; | |
ab7ac4eb TH |
876 | } |
877 | ||
ab7ac4eb TH |
878 | copied += copy; |
879 | if (head != skb) { | |
880 | head->len += copy; | |
881 | head->data_len += copy; | |
882 | } | |
883 | ||
884 | continue; | |
885 | ||
886 | wait_for_memory: | |
887 | kcm_push(kcm); | |
888 | err = sk_stream_wait_memory(sk, &timeo); | |
889 | if (err) | |
890 | goto out_error; | |
891 | } | |
892 | ||
893 | if (eor) { | |
894 | bool not_busy = skb_queue_empty(&sk->sk_write_queue); | |
895 | ||
98e3862c WC |
896 | if (head) { |
897 | /* Message complete, queue it on send buffer */ | |
898 | __skb_queue_tail(&sk->sk_write_queue, head); | |
899 | kcm->seq_skb = NULL; | |
900 | KCM_STATS_INCR(kcm->stats.tx_msgs); | |
901 | } | |
ab7ac4eb TH |
902 | |
903 | if (msg->msg_flags & MSG_BATCH) { | |
904 | kcm->tx_wait_more = true; | |
905 | } else if (kcm->tx_wait_more || not_busy) { | |
906 | err = kcm_write_msgs(kcm); | |
907 | if (err < 0) { | |
908 | /* We got a hard error in write_msgs but have | |
909 | * already queued this message. Report an error | |
910 | * in the socket, but don't affect return value | |
911 | * from sendmsg | |
912 | */ | |
913 | pr_warn("KCM: Hard failure on kcm_write_msgs\n"); | |
914 | report_csk_error(&kcm->sk, -err); | |
915 | } | |
916 | } | |
917 | } else { | |
918 | /* Message not complete, save state */ | |
919 | partial_message: | |
cd27b96b WC |
920 | if (head) { |
921 | kcm->seq_skb = head; | |
922 | kcm_tx_msg(head)->last_skb = skb; | |
923 | } | |
ab7ac4eb TH |
924 | } |
925 | ||
cd6e111b TH |
926 | KCM_STATS_ADD(kcm->stats.tx_bytes, copied); |
927 | ||
ab7ac4eb TH |
928 | release_sock(sk); |
929 | return copied; | |
930 | ||
931 | out_error: | |
932 | kcm_push(kcm); | |
933 | ||
a22730b1 | 934 | if (sock->type == SOCK_SEQPACKET) { |
ab7ac4eb TH |
935 | /* Wrote some bytes before encountering an |
936 | * error, return partial success. | |
937 | */ | |
a22730b1 KI |
938 | if (copied) |
939 | goto partial_message; | |
940 | if (head != kcm->seq_skb) | |
941 | kfree_skb(head); | |
942 | } else { | |
ab7ac4eb | 943 | kfree_skb(head); |
a22730b1 KI |
944 | kcm->seq_skb = NULL; |
945 | } | |
ab7ac4eb TH |
946 | |
947 | err = sk_stream_error(sk, msg->msg_flags, err); | |
948 | ||
949 | /* make sure we wake any epoll edge trigger waiter */ | |
950 | if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) | |
951 | sk->sk_write_space(sk); | |
952 | ||
953 | release_sock(sk); | |
954 | return err; | |
955 | } | |
956 | ||
951ace99 DH |
957 | static void kcm_splice_eof(struct socket *sock) |
958 | { | |
959 | struct sock *sk = sock->sk; | |
960 | struct kcm_sock *kcm = kcm_sk(sk); | |
961 | ||
962 | if (skb_queue_empty_lockless(&sk->sk_write_queue)) | |
963 | return; | |
964 | ||
965 | lock_sock(sk); | |
966 | kcm_write_msgs(kcm); | |
967 | release_sock(sk); | |
968 | } | |
969 | ||
ab7ac4eb TH |
970 | static int kcm_recvmsg(struct socket *sock, struct msghdr *msg, |
971 | size_t len, int flags) | |
972 | { | |
973 | struct sock *sk = sock->sk; | |
cd6e111b | 974 | struct kcm_sock *kcm = kcm_sk(sk); |
ab7ac4eb | 975 | int err = 0; |
bbb03029 | 976 | struct strp_msg *stm; |
ab7ac4eb TH |
977 | int copied = 0; |
978 | struct sk_buff *skb; | |
979 | ||
5121197e | 980 | skb = skb_recv_datagram(sk, flags, &err); |
ab7ac4eb TH |
981 | if (!skb) |
982 | goto out; | |
983 | ||
984 | /* Okay, have a message on the receive queue */ | |
985 | ||
bbb03029 | 986 | stm = strp_msg(skb); |
ab7ac4eb | 987 | |
bbb03029 TH |
988 | if (len > stm->full_len) |
989 | len = stm->full_len; | |
ab7ac4eb | 990 | |
bbb03029 | 991 | err = skb_copy_datagram_msg(skb, stm->offset, msg, len); |
ab7ac4eb TH |
992 | if (err < 0) |
993 | goto out; | |
994 | ||
995 | copied = len; | |
996 | if (likely(!(flags & MSG_PEEK))) { | |
cd6e111b | 997 | KCM_STATS_ADD(kcm->stats.rx_bytes, copied); |
bbb03029 | 998 | if (copied < stm->full_len) { |
ab7ac4eb TH |
999 | if (sock->type == SOCK_DGRAM) { |
1000 | /* Truncated message */ | |
1001 | msg->msg_flags |= MSG_TRUNC; | |
1002 | goto msg_finished; | |
1003 | } | |
bbb03029 TH |
1004 | stm->offset += copied; |
1005 | stm->full_len -= copied; | |
ab7ac4eb TH |
1006 | } else { |
1007 | msg_finished: | |
1008 | /* Finished with message */ | |
1009 | msg->msg_flags |= MSG_EOR; | |
cd6e111b | 1010 | KCM_STATS_INCR(kcm->stats.rx_msgs); |
ab7ac4eb TH |
1011 | } |
1012 | } | |
1013 | ||
1014 | out: | |
5121197e | 1015 | skb_free_datagram(sk, skb); |
ab7ac4eb TH |
1016 | return copied ? : err; |
1017 | } | |
1018 | ||
91687355 TH |
1019 | static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos, |
1020 | struct pipe_inode_info *pipe, size_t len, | |
1021 | unsigned int flags) | |
1022 | { | |
1023 | struct sock *sk = sock->sk; | |
1024 | struct kcm_sock *kcm = kcm_sk(sk); | |
bbb03029 | 1025 | struct strp_msg *stm; |
91687355 | 1026 | int err = 0; |
f1971a2e | 1027 | ssize_t copied; |
91687355 TH |
1028 | struct sk_buff *skb; |
1029 | ||
1030 | /* Only support splice for SOCKSEQPACKET */ | |
1031 | ||
5121197e | 1032 | skb = skb_recv_datagram(sk, flags, &err); |
91687355 TH |
1033 | if (!skb) |
1034 | goto err_out; | |
1035 | ||
1036 | /* Okay, have a message on the receive queue */ | |
1037 | ||
bbb03029 | 1038 | stm = strp_msg(skb); |
91687355 | 1039 | |
bbb03029 TH |
1040 | if (len > stm->full_len) |
1041 | len = stm->full_len; | |
91687355 | 1042 | |
bbb03029 | 1043 | copied = skb_splice_bits(skb, sk, stm->offset, pipe, len, flags); |
91687355 TH |
1044 | if (copied < 0) { |
1045 | err = copied; | |
1046 | goto err_out; | |
1047 | } | |
1048 | ||
1049 | KCM_STATS_ADD(kcm->stats.rx_bytes, copied); | |
1050 | ||
bbb03029 TH |
1051 | stm->offset += copied; |
1052 | stm->full_len -= copied; | |
91687355 TH |
1053 | |
1054 | /* We have no way to return MSG_EOR. If all the bytes have been | |
1055 | * read we still leave the message in the receive socket buffer. | |
1056 | * A subsequent recvmsg needs to be done to return MSG_EOR and | |
1057 | * finish reading the message. | |
1058 | */ | |
1059 | ||
5121197e | 1060 | skb_free_datagram(sk, skb); |
91687355 TH |
1061 | return copied; |
1062 | ||
1063 | err_out: | |
5121197e | 1064 | skb_free_datagram(sk, skb); |
91687355 TH |
1065 | return err; |
1066 | } | |
1067 | ||
ab7ac4eb TH |
1068 | /* kcm sock lock held */ |
1069 | static void kcm_recv_disable(struct kcm_sock *kcm) | |
1070 | { | |
1071 | struct kcm_mux *mux = kcm->mux; | |
1072 | ||
1073 | if (kcm->rx_disabled) | |
1074 | return; | |
1075 | ||
1076 | spin_lock_bh(&mux->rx_lock); | |
1077 | ||
1078 | kcm->rx_disabled = 1; | |
1079 | ||
1080 | /* If a psock is reserved we'll do cleanup in unreserve */ | |
1081 | if (!kcm->rx_psock) { | |
1082 | if (kcm->rx_wait) { | |
1083 | list_del(&kcm->wait_rx_list); | |
0c745b51 ED |
1084 | /* paired with lockless reads in kcm_rfree() */ |
1085 | WRITE_ONCE(kcm->rx_wait, false); | |
ab7ac4eb TH |
1086 | } |
1087 | ||
1088 | requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue); | |
1089 | } | |
1090 | ||
1091 | spin_unlock_bh(&mux->rx_lock); | |
1092 | } | |
1093 | ||
1094 | /* kcm sock lock held */ | |
1095 | static void kcm_recv_enable(struct kcm_sock *kcm) | |
1096 | { | |
1097 | struct kcm_mux *mux = kcm->mux; | |
1098 | ||
1099 | if (!kcm->rx_disabled) | |
1100 | return; | |
1101 | ||
1102 | spin_lock_bh(&mux->rx_lock); | |
1103 | ||
1104 | kcm->rx_disabled = 0; | |
1105 | kcm_rcv_ready(kcm); | |
1106 | ||
1107 | spin_unlock_bh(&mux->rx_lock); | |
1108 | } | |
1109 | ||
1110 | static int kcm_setsockopt(struct socket *sock, int level, int optname, | |
a7b75c5a | 1111 | sockptr_t optval, unsigned int optlen) |
ab7ac4eb TH |
1112 | { |
1113 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1114 | int val, valbool; | |
1115 | int err = 0; | |
1116 | ||
1117 | if (level != SOL_KCM) | |
1118 | return -ENOPROTOOPT; | |
1119 | ||
1120 | if (optlen < sizeof(int)) | |
1121 | return -EINVAL; | |
1122 | ||
a7b75c5a CH |
1123 | if (copy_from_sockptr(&val, optval, sizeof(int))) |
1124 | return -EFAULT; | |
ab7ac4eb TH |
1125 | |
1126 | valbool = val ? 1 : 0; | |
1127 | ||
1128 | switch (optname) { | |
1129 | case KCM_RECV_DISABLE: | |
1130 | lock_sock(&kcm->sk); | |
1131 | if (valbool) | |
1132 | kcm_recv_disable(kcm); | |
1133 | else | |
1134 | kcm_recv_enable(kcm); | |
1135 | release_sock(&kcm->sk); | |
1136 | break; | |
1137 | default: | |
1138 | err = -ENOPROTOOPT; | |
1139 | } | |
1140 | ||
1141 | return err; | |
1142 | } | |
1143 | ||
1144 | static int kcm_getsockopt(struct socket *sock, int level, int optname, | |
1145 | char __user *optval, int __user *optlen) | |
1146 | { | |
1147 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1148 | int val, len; | |
1149 | ||
1150 | if (level != SOL_KCM) | |
1151 | return -ENOPROTOOPT; | |
1152 | ||
1153 | if (get_user(len, optlen)) | |
1154 | return -EFAULT; | |
1155 | ||
ab7ac4eb TH |
1156 | if (len < 0) |
1157 | return -EINVAL; | |
1158 | ||
3ed5f415 GI |
1159 | len = min_t(unsigned int, len, sizeof(int)); |
1160 | ||
ab7ac4eb TH |
1161 | switch (optname) { |
1162 | case KCM_RECV_DISABLE: | |
1163 | val = kcm->rx_disabled; | |
1164 | break; | |
1165 | default: | |
1166 | return -ENOPROTOOPT; | |
1167 | } | |
1168 | ||
1169 | if (put_user(len, optlen)) | |
1170 | return -EFAULT; | |
1171 | if (copy_to_user(optval, &val, len)) | |
1172 | return -EFAULT; | |
1173 | return 0; | |
1174 | } | |
1175 | ||
1176 | static void init_kcm_sock(struct kcm_sock *kcm, struct kcm_mux *mux) | |
1177 | { | |
1178 | struct kcm_sock *tkcm; | |
1179 | struct list_head *head; | |
1180 | int index = 0; | |
1181 | ||
a11e1d43 LT |
1182 | /* For SOCK_SEQPACKET sock type, datagram_poll checks the sk_state, so |
1183 | * we set sk_state, otherwise epoll_wait always returns right away with | |
1184 | * EPOLLHUP | |
ab7ac4eb TH |
1185 | */ |
1186 | kcm->sk.sk_state = TCP_ESTABLISHED; | |
1187 | ||
1188 | /* Add to mux's kcm sockets list */ | |
1189 | kcm->mux = mux; | |
1190 | spin_lock_bh(&mux->lock); | |
1191 | ||
1192 | head = &mux->kcm_socks; | |
1193 | list_for_each_entry(tkcm, &mux->kcm_socks, kcm_sock_list) { | |
1194 | if (tkcm->index != index) | |
1195 | break; | |
1196 | head = &tkcm->kcm_sock_list; | |
1197 | index++; | |
1198 | } | |
1199 | ||
1200 | list_add(&kcm->kcm_sock_list, head); | |
1201 | kcm->index = index; | |
1202 | ||
1203 | mux->kcm_socks_cnt++; | |
1204 | spin_unlock_bh(&mux->lock); | |
1205 | ||
1206 | INIT_WORK(&kcm->tx_work, kcm_tx_work); | |
1207 | ||
1208 | spin_lock_bh(&mux->rx_lock); | |
1209 | kcm_rcv_ready(kcm); | |
1210 | spin_unlock_bh(&mux->rx_lock); | |
1211 | } | |
1212 | ||
1213 | static int kcm_attach(struct socket *sock, struct socket *csock, | |
1214 | struct bpf_prog *prog) | |
1215 | { | |
1216 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1217 | struct kcm_mux *mux = kcm->mux; | |
1218 | struct sock *csk; | |
1219 | struct kcm_psock *psock = NULL, *tpsock; | |
1220 | struct list_head *head; | |
1221 | int index = 0; | |
3fd87127 EB |
1222 | static const struct strp_callbacks cb = { |
1223 | .rcv_msg = kcm_rcv_strparser, | |
1224 | .parse_msg = kcm_parse_func_strparser, | |
1225 | .read_sock_done = kcm_read_sock_done, | |
1226 | }; | |
2cc683e8 | 1227 | int err = 0; |
ab7ac4eb TH |
1228 | |
1229 | csk = csock->sk; | |
1230 | if (!csk) | |
1231 | return -EINVAL; | |
1232 | ||
2cc683e8 TH |
1233 | lock_sock(csk); |
1234 | ||
581e7226 TH |
1235 | /* Only allow TCP sockets to be attached for now */ |
1236 | if ((csk->sk_family != AF_INET && csk->sk_family != AF_INET6) || | |
2cc683e8 TH |
1237 | csk->sk_protocol != IPPROTO_TCP) { |
1238 | err = -EOPNOTSUPP; | |
1239 | goto out; | |
1240 | } | |
581e7226 TH |
1241 | |
1242 | /* Don't allow listeners or closed sockets */ | |
2cc683e8 TH |
1243 | if (csk->sk_state == TCP_LISTEN || csk->sk_state == TCP_CLOSE) { |
1244 | err = -EOPNOTSUPP; | |
1245 | goto out; | |
1246 | } | |
351050ec | 1247 | |
ab7ac4eb | 1248 | psock = kmem_cache_zalloc(kcm_psockp, GFP_KERNEL); |
2cc683e8 TH |
1249 | if (!psock) { |
1250 | err = -ENOMEM; | |
1251 | goto out; | |
1252 | } | |
ab7ac4eb TH |
1253 | |
1254 | psock->mux = mux; | |
1255 | psock->sk = csk; | |
1256 | psock->bpf_prog = prog; | |
29152a34 | 1257 | |
ab7ac4eb | 1258 | write_lock_bh(&csk->sk_callback_lock); |
e5571240 | 1259 | |
71a2fae5 | 1260 | /* Check if sk_user_data is already by KCM or someone else. |
e5571240 TH |
1261 | * Must be done under lock to prevent race conditions. |
1262 | */ | |
1263 | if (csk->sk_user_data) { | |
1264 | write_unlock_bh(&csk->sk_callback_lock); | |
e5571240 | 1265 | kmem_cache_free(kcm_psockp, psock); |
2cc683e8 TH |
1266 | err = -EALREADY; |
1267 | goto out; | |
e5571240 TH |
1268 | } |
1269 | ||
8fc29ff3 CW |
1270 | err = strp_init(&psock->strp, csk, &cb); |
1271 | if (err) { | |
1272 | write_unlock_bh(&csk->sk_callback_lock); | |
1273 | kmem_cache_free(kcm_psockp, psock); | |
1274 | goto out; | |
1275 | } | |
1276 | ||
ab7ac4eb TH |
1277 | psock->save_data_ready = csk->sk_data_ready; |
1278 | psock->save_write_space = csk->sk_write_space; | |
1279 | psock->save_state_change = csk->sk_state_change; | |
1280 | csk->sk_user_data = psock; | |
96a59083 TH |
1281 | csk->sk_data_ready = psock_data_ready; |
1282 | csk->sk_write_space = psock_write_space; | |
1283 | csk->sk_state_change = psock_state_change; | |
e5571240 | 1284 | |
ab7ac4eb TH |
1285 | write_unlock_bh(&csk->sk_callback_lock); |
1286 | ||
e5571240 TH |
1287 | sock_hold(csk); |
1288 | ||
ab7ac4eb TH |
1289 | /* Finished initialization, now add the psock to the MUX. */ |
1290 | spin_lock_bh(&mux->lock); | |
1291 | head = &mux->psocks; | |
1292 | list_for_each_entry(tpsock, &mux->psocks, psock_list) { | |
1293 | if (tpsock->index != index) | |
1294 | break; | |
1295 | head = &tpsock->psock_list; | |
1296 | index++; | |
1297 | } | |
1298 | ||
1299 | list_add(&psock->psock_list, head); | |
1300 | psock->index = index; | |
1301 | ||
cd6e111b | 1302 | KCM_STATS_INCR(mux->stats.psock_attach); |
ab7ac4eb TH |
1303 | mux->psocks_cnt++; |
1304 | psock_now_avail(psock); | |
1305 | spin_unlock_bh(&mux->lock); | |
1306 | ||
1307 | /* Schedule RX work in case there are already bytes queued */ | |
9b73896a | 1308 | strp_check_rcv(&psock->strp); |
ab7ac4eb | 1309 | |
2cc683e8 TH |
1310 | out: |
1311 | release_sock(csk); | |
1312 | ||
1313 | return err; | |
ab7ac4eb TH |
1314 | } |
1315 | ||
1316 | static int kcm_attach_ioctl(struct socket *sock, struct kcm_attach *info) | |
1317 | { | |
1318 | struct socket *csock; | |
1319 | struct bpf_prog *prog; | |
1320 | int err; | |
1321 | ||
1322 | csock = sockfd_lookup(info->fd, &err); | |
1323 | if (!csock) | |
1324 | return -ENOENT; | |
1325 | ||
113214be | 1326 | prog = bpf_prog_get_type(info->bpf_fd, BPF_PROG_TYPE_SOCKET_FILTER); |
ab7ac4eb TH |
1327 | if (IS_ERR(prog)) { |
1328 | err = PTR_ERR(prog); | |
1329 | goto out; | |
1330 | } | |
1331 | ||
ab7ac4eb TH |
1332 | err = kcm_attach(sock, csock, prog); |
1333 | if (err) { | |
1334 | bpf_prog_put(prog); | |
1335 | goto out; | |
1336 | } | |
1337 | ||
1338 | /* Keep reference on file also */ | |
1339 | ||
1340 | return 0; | |
1341 | out: | |
8dc879a1 | 1342 | sockfd_put(csock); |
ab7ac4eb TH |
1343 | return err; |
1344 | } | |
1345 | ||
1346 | static void kcm_unattach(struct kcm_psock *psock) | |
1347 | { | |
1348 | struct sock *csk = psock->sk; | |
1349 | struct kcm_mux *mux = psock->mux; | |
1350 | ||
1616b38f TH |
1351 | lock_sock(csk); |
1352 | ||
ab7ac4eb TH |
1353 | /* Stop getting callbacks from TCP socket. After this there should |
1354 | * be no way to reserve a kcm for this psock. | |
1355 | */ | |
1356 | write_lock_bh(&csk->sk_callback_lock); | |
1357 | csk->sk_user_data = NULL; | |
1358 | csk->sk_data_ready = psock->save_data_ready; | |
1359 | csk->sk_write_space = psock->save_write_space; | |
1360 | csk->sk_state_change = psock->save_state_change; | |
9b73896a | 1361 | strp_stop(&psock->strp); |
ab7ac4eb TH |
1362 | |
1363 | if (WARN_ON(psock->rx_kcm)) { | |
1364 | write_unlock_bh(&csk->sk_callback_lock); | |
2cc683e8 | 1365 | release_sock(csk); |
ab7ac4eb TH |
1366 | return; |
1367 | } | |
1368 | ||
1369 | spin_lock_bh(&mux->rx_lock); | |
1370 | ||
1371 | /* Stop receiver activities. After this point psock should not be | |
1372 | * able to get onto ready list either through callbacks or work. | |
1373 | */ | |
1374 | if (psock->ready_rx_msg) { | |
1375 | list_del(&psock->psock_ready_list); | |
1376 | kfree_skb(psock->ready_rx_msg); | |
1377 | psock->ready_rx_msg = NULL; | |
cd6e111b | 1378 | KCM_STATS_INCR(mux->stats.rx_ready_drops); |
ab7ac4eb TH |
1379 | } |
1380 | ||
1381 | spin_unlock_bh(&mux->rx_lock); | |
1382 | ||
1383 | write_unlock_bh(&csk->sk_callback_lock); | |
1384 | ||
1616b38f TH |
1385 | /* Call strp_done without sock lock */ |
1386 | release_sock(csk); | |
9b73896a | 1387 | strp_done(&psock->strp); |
1616b38f | 1388 | lock_sock(csk); |
ab7ac4eb TH |
1389 | |
1390 | bpf_prog_put(psock->bpf_prog); | |
1391 | ||
ab7ac4eb TH |
1392 | spin_lock_bh(&mux->lock); |
1393 | ||
cd6e111b | 1394 | aggregate_psock_stats(&psock->stats, &mux->aggregate_psock_stats); |
9b73896a | 1395 | save_strp_stats(&psock->strp, &mux->aggregate_strp_stats); |
cd6e111b TH |
1396 | |
1397 | KCM_STATS_INCR(mux->stats.psock_unattach); | |
1398 | ||
ab7ac4eb TH |
1399 | if (psock->tx_kcm) { |
1400 | /* psock was reserved. Just mark it finished and we will clean | |
1401 | * up in the kcm paths, we need kcm lock which can not be | |
1402 | * acquired here. | |
1403 | */ | |
cd6e111b | 1404 | KCM_STATS_INCR(mux->stats.psock_unattach_rsvd); |
ab7ac4eb TH |
1405 | spin_unlock_bh(&mux->lock); |
1406 | ||
1407 | /* We are unattaching a socket that is reserved. Abort the | |
1408 | * socket since we may be out of sync in sending on it. We need | |
1409 | * to do this without the mux lock. | |
1410 | */ | |
1411 | kcm_abort_tx_psock(psock, EPIPE, false); | |
1412 | ||
1413 | spin_lock_bh(&mux->lock); | |
1414 | if (!psock->tx_kcm) { | |
1415 | /* psock now unreserved in window mux was unlocked */ | |
1416 | goto no_reserved; | |
1417 | } | |
1418 | psock->done = 1; | |
1419 | ||
1420 | /* Commit done before queuing work to process it */ | |
1421 | smp_mb(); | |
1422 | ||
1423 | /* Queue tx work to make sure psock->done is handled */ | |
1424 | queue_work(kcm_wq, &psock->tx_kcm->tx_work); | |
1425 | spin_unlock_bh(&mux->lock); | |
1426 | } else { | |
1427 | no_reserved: | |
1428 | if (!psock->tx_stopped) | |
1429 | list_del(&psock->psock_avail_list); | |
1430 | list_del(&psock->psock_list); | |
1431 | mux->psocks_cnt--; | |
1432 | spin_unlock_bh(&mux->lock); | |
1433 | ||
1434 | sock_put(csk); | |
1435 | fput(csk->sk_socket->file); | |
1436 | kmem_cache_free(kcm_psockp, psock); | |
1437 | } | |
1616b38f TH |
1438 | |
1439 | release_sock(csk); | |
ab7ac4eb TH |
1440 | } |
1441 | ||
1442 | static int kcm_unattach_ioctl(struct socket *sock, struct kcm_unattach *info) | |
1443 | { | |
1444 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1445 | struct kcm_mux *mux = kcm->mux; | |
1446 | struct kcm_psock *psock; | |
1447 | struct socket *csock; | |
1448 | struct sock *csk; | |
1449 | int err; | |
1450 | ||
1451 | csock = sockfd_lookup(info->fd, &err); | |
1452 | if (!csock) | |
1453 | return -ENOENT; | |
1454 | ||
1455 | csk = csock->sk; | |
1456 | if (!csk) { | |
1457 | err = -EINVAL; | |
1458 | goto out; | |
1459 | } | |
1460 | ||
1461 | err = -ENOENT; | |
1462 | ||
1463 | spin_lock_bh(&mux->lock); | |
1464 | ||
1465 | list_for_each_entry(psock, &mux->psocks, psock_list) { | |
1466 | if (psock->sk != csk) | |
1467 | continue; | |
1468 | ||
1469 | /* Found the matching psock */ | |
1470 | ||
1471 | if (psock->unattaching || WARN_ON(psock->done)) { | |
1472 | err = -EALREADY; | |
1473 | break; | |
1474 | } | |
1475 | ||
1476 | psock->unattaching = 1; | |
1477 | ||
1478 | spin_unlock_bh(&mux->lock); | |
1479 | ||
9b73896a | 1480 | /* Lower socket lock should already be held */ |
ab7ac4eb TH |
1481 | kcm_unattach(psock); |
1482 | ||
1483 | err = 0; | |
1484 | goto out; | |
1485 | } | |
1486 | ||
1487 | spin_unlock_bh(&mux->lock); | |
1488 | ||
1489 | out: | |
8dc879a1 | 1490 | sockfd_put(csock); |
ab7ac4eb TH |
1491 | return err; |
1492 | } | |
1493 | ||
1494 | static struct proto kcm_proto = { | |
1495 | .name = "KCM", | |
1496 | .owner = THIS_MODULE, | |
1497 | .obj_size = sizeof(struct kcm_sock), | |
1498 | }; | |
1499 | ||
1500 | /* Clone a kcm socket. */ | |
a5739435 | 1501 | static struct file *kcm_clone(struct socket *osock) |
ab7ac4eb TH |
1502 | { |
1503 | struct socket *newsock; | |
1504 | struct sock *newsk; | |
ab7ac4eb | 1505 | |
ab7ac4eb TH |
1506 | newsock = sock_alloc(); |
1507 | if (!newsock) | |
a5739435 | 1508 | return ERR_PTR(-ENFILE); |
ab7ac4eb TH |
1509 | |
1510 | newsock->type = osock->type; | |
1511 | newsock->ops = osock->ops; | |
1512 | ||
1513 | __module_get(newsock->ops->owner); | |
1514 | ||
ab7ac4eb | 1515 | newsk = sk_alloc(sock_net(osock->sk), PF_KCM, GFP_KERNEL, |
eb7f54b9 | 1516 | &kcm_proto, false); |
ab7ac4eb | 1517 | if (!newsk) { |
a5739435 AV |
1518 | sock_release(newsock); |
1519 | return ERR_PTR(-ENOMEM); | |
ab7ac4eb | 1520 | } |
ab7ac4eb TH |
1521 | sock_init_data(newsock, newsk); |
1522 | init_kcm_sock(kcm_sk(newsk), kcm_sk(osock->sk)->mux); | |
1523 | ||
8e1611e2 | 1524 | return sock_alloc_file(newsock, 0, osock->sk->sk_prot_creator->name); |
ab7ac4eb TH |
1525 | } |
1526 | ||
1527 | static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) | |
1528 | { | |
1529 | int err; | |
1530 | ||
1531 | switch (cmd) { | |
1532 | case SIOCKCMATTACH: { | |
1533 | struct kcm_attach info; | |
1534 | ||
1535 | if (copy_from_user(&info, (void __user *)arg, sizeof(info))) | |
a80db69e | 1536 | return -EFAULT; |
ab7ac4eb TH |
1537 | |
1538 | err = kcm_attach_ioctl(sock, &info); | |
1539 | ||
1540 | break; | |
1541 | } | |
1542 | case SIOCKCMUNATTACH: { | |
1543 | struct kcm_unattach info; | |
1544 | ||
1545 | if (copy_from_user(&info, (void __user *)arg, sizeof(info))) | |
a80db69e | 1546 | return -EFAULT; |
ab7ac4eb TH |
1547 | |
1548 | err = kcm_unattach_ioctl(sock, &info); | |
1549 | ||
1550 | break; | |
1551 | } | |
1552 | case SIOCKCMCLONE: { | |
1553 | struct kcm_clone info; | |
a5739435 AV |
1554 | struct file *file; |
1555 | ||
1556 | info.fd = get_unused_fd_flags(0); | |
1557 | if (unlikely(info.fd < 0)) | |
1558 | return info.fd; | |
ab7ac4eb | 1559 | |
a5739435 AV |
1560 | file = kcm_clone(sock); |
1561 | if (IS_ERR(file)) { | |
1562 | put_unused_fd(info.fd); | |
1563 | return PTR_ERR(file); | |
1564 | } | |
1565 | if (copy_to_user((void __user *)arg, &info, | |
1566 | sizeof(info))) { | |
1567 | put_unused_fd(info.fd); | |
1568 | fput(file); | |
1569 | return -EFAULT; | |
1570 | } | |
1571 | fd_install(info.fd, file); | |
1572 | err = 0; | |
ab7ac4eb TH |
1573 | break; |
1574 | } | |
1575 | default: | |
1576 | err = -ENOIOCTLCMD; | |
1577 | break; | |
1578 | } | |
1579 | ||
1580 | return err; | |
1581 | } | |
1582 | ||
1583 | static void free_mux(struct rcu_head *rcu) | |
1584 | { | |
1585 | struct kcm_mux *mux = container_of(rcu, | |
1586 | struct kcm_mux, rcu); | |
1587 | ||
1588 | kmem_cache_free(kcm_muxp, mux); | |
1589 | } | |
1590 | ||
1591 | static void release_mux(struct kcm_mux *mux) | |
1592 | { | |
1593 | struct kcm_net *knet = mux->knet; | |
1594 | struct kcm_psock *psock, *tmp_psock; | |
1595 | ||
1596 | /* Release psocks */ | |
1597 | list_for_each_entry_safe(psock, tmp_psock, | |
1598 | &mux->psocks, psock_list) { | |
1616b38f | 1599 | if (!WARN_ON(psock->unattaching)) |
ab7ac4eb TH |
1600 | kcm_unattach(psock); |
1601 | } | |
1602 | ||
1603 | if (WARN_ON(mux->psocks_cnt)) | |
1604 | return; | |
1605 | ||
1606 | __skb_queue_purge(&mux->rx_hold_queue); | |
1607 | ||
1608 | mutex_lock(&knet->mutex); | |
cd6e111b TH |
1609 | aggregate_mux_stats(&mux->stats, &knet->aggregate_mux_stats); |
1610 | aggregate_psock_stats(&mux->aggregate_psock_stats, | |
1611 | &knet->aggregate_psock_stats); | |
9b73896a TH |
1612 | aggregate_strp_stats(&mux->aggregate_strp_stats, |
1613 | &knet->aggregate_strp_stats); | |
ab7ac4eb TH |
1614 | list_del_rcu(&mux->kcm_mux_list); |
1615 | knet->count--; | |
1616 | mutex_unlock(&knet->mutex); | |
1617 | ||
1618 | call_rcu(&mux->rcu, free_mux); | |
1619 | } | |
1620 | ||
1621 | static void kcm_done(struct kcm_sock *kcm) | |
1622 | { | |
1623 | struct kcm_mux *mux = kcm->mux; | |
1624 | struct sock *sk = &kcm->sk; | |
1625 | int socks_cnt; | |
1626 | ||
1627 | spin_lock_bh(&mux->rx_lock); | |
1628 | if (kcm->rx_psock) { | |
1629 | /* Cleanup in unreserve_rx_kcm */ | |
1630 | WARN_ON(kcm->done); | |
1631 | kcm->rx_disabled = 1; | |
1632 | kcm->done = 1; | |
1633 | spin_unlock_bh(&mux->rx_lock); | |
1634 | return; | |
1635 | } | |
1636 | ||
1637 | if (kcm->rx_wait) { | |
1638 | list_del(&kcm->wait_rx_list); | |
0c745b51 ED |
1639 | /* paired with lockless reads in kcm_rfree() */ |
1640 | WRITE_ONCE(kcm->rx_wait, false); | |
ab7ac4eb TH |
1641 | } |
1642 | /* Move any pending receive messages to other kcm sockets */ | |
1643 | requeue_rx_msgs(mux, &sk->sk_receive_queue); | |
1644 | ||
1645 | spin_unlock_bh(&mux->rx_lock); | |
1646 | ||
1647 | if (WARN_ON(sk_rmem_alloc_get(sk))) | |
1648 | return; | |
1649 | ||
1650 | /* Detach from MUX */ | |
1651 | spin_lock_bh(&mux->lock); | |
1652 | ||
1653 | list_del(&kcm->kcm_sock_list); | |
1654 | mux->kcm_socks_cnt--; | |
1655 | socks_cnt = mux->kcm_socks_cnt; | |
1656 | ||
1657 | spin_unlock_bh(&mux->lock); | |
1658 | ||
1659 | if (!socks_cnt) { | |
1660 | /* We are done with the mux now. */ | |
1661 | release_mux(mux); | |
1662 | } | |
1663 | ||
1664 | WARN_ON(kcm->rx_wait); | |
1665 | ||
1666 | sock_put(&kcm->sk); | |
1667 | } | |
1668 | ||
1669 | /* Called by kcm_release to close a KCM socket. | |
1670 | * If this is the last KCM socket on the MUX, destroy the MUX. | |
1671 | */ | |
1672 | static int kcm_release(struct socket *sock) | |
1673 | { | |
1674 | struct sock *sk = sock->sk; | |
1675 | struct kcm_sock *kcm; | |
1676 | struct kcm_mux *mux; | |
1677 | struct kcm_psock *psock; | |
1678 | ||
1679 | if (!sk) | |
1680 | return 0; | |
1681 | ||
1682 | kcm = kcm_sk(sk); | |
1683 | mux = kcm->mux; | |
1684 | ||
ec7eede3 | 1685 | lock_sock(sk); |
ab7ac4eb TH |
1686 | sock_orphan(sk); |
1687 | kfree_skb(kcm->seq_skb); | |
1688 | ||
ab7ac4eb TH |
1689 | /* Purge queue under lock to avoid race condition with tx_work trying |
1690 | * to act when queue is nonempty. If tx_work runs after this point | |
1691 | * it will just return. | |
1692 | */ | |
1693 | __skb_queue_purge(&sk->sk_write_queue); | |
9b73896a TH |
1694 | |
1695 | /* Set tx_stopped. This is checked when psock is bound to a kcm and we | |
1696 | * get a writespace callback. This prevents further work being queued | |
1697 | * from the callback (unbinding the psock occurs after canceling work. | |
1698 | */ | |
1699 | kcm->tx_stopped = 1; | |
1700 | ||
ab7ac4eb TH |
1701 | release_sock(sk); |
1702 | ||
1703 | spin_lock_bh(&mux->lock); | |
1704 | if (kcm->tx_wait) { | |
1705 | /* Take of tx_wait list, after this point there should be no way | |
1706 | * that a psock will be assigned to this kcm. | |
1707 | */ | |
1708 | list_del(&kcm->wait_psock_list); | |
1709 | kcm->tx_wait = false; | |
1710 | } | |
1711 | spin_unlock_bh(&mux->lock); | |
1712 | ||
1713 | /* Cancel work. After this point there should be no outside references | |
1714 | * to the kcm socket. | |
1715 | */ | |
1716 | cancel_work_sync(&kcm->tx_work); | |
1717 | ||
1718 | lock_sock(sk); | |
1719 | psock = kcm->tx_psock; | |
1720 | if (psock) { | |
1721 | /* A psock was reserved, so we need to kill it since it | |
1722 | * may already have some bytes queued from a message. We | |
1723 | * need to do this after removing kcm from tx_wait list. | |
1724 | */ | |
1725 | kcm_abort_tx_psock(psock, EPIPE, false); | |
1726 | unreserve_psock(kcm); | |
1727 | } | |
1728 | release_sock(sk); | |
1729 | ||
1730 | WARN_ON(kcm->tx_wait); | |
1731 | WARN_ON(kcm->tx_psock); | |
1732 | ||
1733 | sock->sk = NULL; | |
1734 | ||
1735 | kcm_done(kcm); | |
1736 | ||
1737 | return 0; | |
1738 | } | |
1739 | ||
91687355 | 1740 | static const struct proto_ops kcm_dgram_ops = { |
ab7ac4eb TH |
1741 | .family = PF_KCM, |
1742 | .owner = THIS_MODULE, | |
1743 | .release = kcm_release, | |
1744 | .bind = sock_no_bind, | |
1745 | .connect = sock_no_connect, | |
1746 | .socketpair = sock_no_socketpair, | |
1747 | .accept = sock_no_accept, | |
1748 | .getname = sock_no_getname, | |
a11e1d43 | 1749 | .poll = datagram_poll, |
ab7ac4eb TH |
1750 | .ioctl = kcm_ioctl, |
1751 | .listen = sock_no_listen, | |
1752 | .shutdown = sock_no_shutdown, | |
1753 | .setsockopt = kcm_setsockopt, | |
1754 | .getsockopt = kcm_getsockopt, | |
1755 | .sendmsg = kcm_sendmsg, | |
1756 | .recvmsg = kcm_recvmsg, | |
1757 | .mmap = sock_no_mmap, | |
951ace99 | 1758 | .splice_eof = kcm_splice_eof, |
ab7ac4eb TH |
1759 | }; |
1760 | ||
91687355 TH |
1761 | static const struct proto_ops kcm_seqpacket_ops = { |
1762 | .family = PF_KCM, | |
1763 | .owner = THIS_MODULE, | |
1764 | .release = kcm_release, | |
1765 | .bind = sock_no_bind, | |
1766 | .connect = sock_no_connect, | |
1767 | .socketpair = sock_no_socketpair, | |
1768 | .accept = sock_no_accept, | |
1769 | .getname = sock_no_getname, | |
a11e1d43 | 1770 | .poll = datagram_poll, |
91687355 TH |
1771 | .ioctl = kcm_ioctl, |
1772 | .listen = sock_no_listen, | |
1773 | .shutdown = sock_no_shutdown, | |
1774 | .setsockopt = kcm_setsockopt, | |
1775 | .getsockopt = kcm_getsockopt, | |
1776 | .sendmsg = kcm_sendmsg, | |
1777 | .recvmsg = kcm_recvmsg, | |
1778 | .mmap = sock_no_mmap, | |
951ace99 | 1779 | .splice_eof = kcm_splice_eof, |
91687355 TH |
1780 | .splice_read = kcm_splice_read, |
1781 | }; | |
1782 | ||
ab7ac4eb TH |
1783 | /* Create proto operation for kcm sockets */ |
1784 | static int kcm_create(struct net *net, struct socket *sock, | |
1785 | int protocol, int kern) | |
1786 | { | |
1787 | struct kcm_net *knet = net_generic(net, kcm_net_id); | |
1788 | struct sock *sk; | |
1789 | struct kcm_mux *mux; | |
1790 | ||
1791 | switch (sock->type) { | |
1792 | case SOCK_DGRAM: | |
91687355 TH |
1793 | sock->ops = &kcm_dgram_ops; |
1794 | break; | |
ab7ac4eb | 1795 | case SOCK_SEQPACKET: |
91687355 | 1796 | sock->ops = &kcm_seqpacket_ops; |
ab7ac4eb TH |
1797 | break; |
1798 | default: | |
1799 | return -ESOCKTNOSUPPORT; | |
1800 | } | |
1801 | ||
1802 | if (protocol != KCMPROTO_CONNECTED) | |
1803 | return -EPROTONOSUPPORT; | |
1804 | ||
1805 | sk = sk_alloc(net, PF_KCM, GFP_KERNEL, &kcm_proto, kern); | |
1806 | if (!sk) | |
1807 | return -ENOMEM; | |
1808 | ||
1809 | /* Allocate a kcm mux, shared between KCM sockets */ | |
1810 | mux = kmem_cache_zalloc(kcm_muxp, GFP_KERNEL); | |
1811 | if (!mux) { | |
1812 | sk_free(sk); | |
1813 | return -ENOMEM; | |
1814 | } | |
1815 | ||
1816 | spin_lock_init(&mux->lock); | |
1817 | spin_lock_init(&mux->rx_lock); | |
1818 | INIT_LIST_HEAD(&mux->kcm_socks); | |
1819 | INIT_LIST_HEAD(&mux->kcm_rx_waiters); | |
1820 | INIT_LIST_HEAD(&mux->kcm_tx_waiters); | |
1821 | ||
1822 | INIT_LIST_HEAD(&mux->psocks); | |
1823 | INIT_LIST_HEAD(&mux->psocks_ready); | |
1824 | INIT_LIST_HEAD(&mux->psocks_avail); | |
1825 | ||
1826 | mux->knet = knet; | |
1827 | ||
1828 | /* Add new MUX to list */ | |
1829 | mutex_lock(&knet->mutex); | |
1830 | list_add_rcu(&mux->kcm_mux_list, &knet->mux_list); | |
1831 | knet->count++; | |
1832 | mutex_unlock(&knet->mutex); | |
1833 | ||
1834 | skb_queue_head_init(&mux->rx_hold_queue); | |
1835 | ||
1836 | /* Init KCM socket */ | |
1837 | sock_init_data(sock, sk); | |
1838 | init_kcm_sock(kcm_sk(sk), mux); | |
1839 | ||
1840 | return 0; | |
1841 | } | |
1842 | ||
173e7837 | 1843 | static const struct net_proto_family kcm_family_ops = { |
ab7ac4eb TH |
1844 | .family = PF_KCM, |
1845 | .create = kcm_create, | |
1846 | .owner = THIS_MODULE, | |
1847 | }; | |
1848 | ||
1849 | static __net_init int kcm_init_net(struct net *net) | |
1850 | { | |
1851 | struct kcm_net *knet = net_generic(net, kcm_net_id); | |
1852 | ||
1853 | INIT_LIST_HEAD_RCU(&knet->mux_list); | |
1854 | mutex_init(&knet->mutex); | |
1855 | ||
1856 | return 0; | |
1857 | } | |
1858 | ||
1859 | static __net_exit void kcm_exit_net(struct net *net) | |
1860 | { | |
1861 | struct kcm_net *knet = net_generic(net, kcm_net_id); | |
1862 | ||
1863 | /* All KCM sockets should be closed at this point, which should mean | |
1864 | * that all multiplexors and psocks have been destroyed. | |
1865 | */ | |
1866 | WARN_ON(!list_empty(&knet->mux_list)); | |
6ad40b36 SY |
1867 | |
1868 | mutex_destroy(&knet->mutex); | |
ab7ac4eb TH |
1869 | } |
1870 | ||
1871 | static struct pernet_operations kcm_net_ops = { | |
1872 | .init = kcm_init_net, | |
1873 | .exit = kcm_exit_net, | |
1874 | .id = &kcm_net_id, | |
1875 | .size = sizeof(struct kcm_net), | |
1876 | }; | |
1877 | ||
1878 | static int __init kcm_init(void) | |
1879 | { | |
1880 | int err = -ENOMEM; | |
1881 | ||
5073d64e | 1882 | kcm_muxp = KMEM_CACHE(kcm_mux, SLAB_HWCACHE_ALIGN); |
ab7ac4eb TH |
1883 | if (!kcm_muxp) |
1884 | goto fail; | |
1885 | ||
5073d64e | 1886 | kcm_psockp = KMEM_CACHE(kcm_psock, SLAB_HWCACHE_ALIGN); |
ab7ac4eb TH |
1887 | if (!kcm_psockp) |
1888 | goto fail; | |
1889 | ||
1890 | kcm_wq = create_singlethread_workqueue("kkcmd"); | |
1891 | if (!kcm_wq) | |
1892 | goto fail; | |
1893 | ||
1894 | err = proto_register(&kcm_proto, 1); | |
1895 | if (err) | |
1896 | goto fail; | |
1897 | ||
ab7ac4eb TH |
1898 | err = register_pernet_device(&kcm_net_ops); |
1899 | if (err) | |
1900 | goto net_ops_fail; | |
1901 | ||
3c446e6f JS |
1902 | err = sock_register(&kcm_family_ops); |
1903 | if (err) | |
1904 | goto sock_register_fail; | |
1905 | ||
cd6e111b TH |
1906 | err = kcm_proc_init(); |
1907 | if (err) | |
1908 | goto proc_init_fail; | |
1909 | ||
ab7ac4eb TH |
1910 | return 0; |
1911 | ||
cd6e111b | 1912 | proc_init_fail: |
ab7ac4eb TH |
1913 | sock_unregister(PF_KCM); |
1914 | ||
1915 | sock_register_fail: | |
3c446e6f JS |
1916 | unregister_pernet_device(&kcm_net_ops); |
1917 | ||
1918 | net_ops_fail: | |
ab7ac4eb TH |
1919 | proto_unregister(&kcm_proto); |
1920 | ||
1921 | fail: | |
1922 | kmem_cache_destroy(kcm_muxp); | |
1923 | kmem_cache_destroy(kcm_psockp); | |
1924 | ||
1925 | if (kcm_wq) | |
1926 | destroy_workqueue(kcm_wq); | |
1927 | ||
1928 | return err; | |
1929 | } | |
1930 | ||
1931 | static void __exit kcm_exit(void) | |
1932 | { | |
cd6e111b | 1933 | kcm_proc_exit(); |
ab7ac4eb | 1934 | sock_unregister(PF_KCM); |
3c446e6f | 1935 | unregister_pernet_device(&kcm_net_ops); |
ab7ac4eb TH |
1936 | proto_unregister(&kcm_proto); |
1937 | destroy_workqueue(kcm_wq); | |
1938 | ||
1939 | kmem_cache_destroy(kcm_muxp); | |
1940 | kmem_cache_destroy(kcm_psockp); | |
1941 | } | |
1942 | ||
1943 | module_init(kcm_init); | |
1944 | module_exit(kcm_exit); | |
1945 | ||
1946 | MODULE_LICENSE("GPL"); | |
31356547 | 1947 | MODULE_DESCRIPTION("KCM (Kernel Connection Multiplexor) sockets"); |
ab7ac4eb | 1948 | MODULE_ALIAS_NETPROTO(PF_KCM); |