1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Kernel Connection Multiplexor |
4 | * |
5 | * Copyright (c) 2016 Tom Herbert <tom@herbertland.com> |
6 | */ |
7 | |
8 | #include <linux/bpf.h> |
9 | #include <linux/errno.h> |
10 | #include <linux/errqueue.h> |
11 | #include <linux/file.h> |
12 | #include <linux/filter.h> |
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> |
24 | #include <linux/syscalls.h> |
25 | #include <linux/sched/signal.h> |
26 | |
27 | #include <net/kcm.h> |
28 | #include <net/netns/generic.h> |
29 | #include <net/sock.h> |
30 | #include <uapi/linux/kcm.h> |
31 | #include <trace/events/sock.h> |
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 | |
49 | static void report_csk_error(struct sock *csk, int err) |
50 | { |
51 | csk->sk_err = EPIPE; |
52 | sk_error_report(sk: csk); |
53 | } |
54 | |
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(lock: &mux->lock); |
64 | |
65 | if (psock->tx_stopped) { |
66 | spin_unlock_bh(lock: &mux->lock); |
67 | return; |
68 | } |
69 | |
70 | psock->tx_stopped = 1; |
71 | KCM_STATS_INCR(psock->stats.tx_aborts); |
72 | |
73 | if (!psock->tx_kcm) { |
74 | /* Take off psocks_avail list */ |
75 | list_del(entry: &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(wq: kcm_wq, work: &psock->tx_kcm->tx_work); |
85 | } |
86 | |
87 | spin_unlock_bh(lock: &mux->lock); |
88 | |
89 | /* Report error on lower socket */ |
90 | report_csk_error(csk, err); |
91 | } |
92 | |
93 | /* RX mux lock held. */ |
94 | static void kcm_update_rx_mux_stats(struct kcm_mux *mux, |
95 | struct kcm_psock *psock) |
96 | { |
97 | STRP_STATS_ADD(mux->stats.rx_bytes, |
98 | psock->strp.stats.bytes - |
99 | psock->saved_rx_bytes); |
100 | mux->stats.rx_msgs += |
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; |
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 | |
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(sk: &kcm->sk, skb)) { |
134 | /* Assuming buffer limit has been reached */ |
135 | skb_queue_head(list: &mux->rx_hold_queue, newsk: skb); |
136 | WARN_ON(!sk_rmem_alloc_get(&kcm->sk)); |
137 | return; |
138 | } |
139 | } |
140 | |
141 | while (!list_empty(head: &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(sk: &kcm->sk, skb: 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(entry: &psock->psock_ready_list); |
155 | psock->ready_rx_msg = NULL; |
156 | /* Commit clearing of ready_rx_msg for queuing work */ |
157 | smp_mb(); |
158 | |
159 | strp_unpause(strp: &psock->strp); |
160 | strp_check_rcv(strp: &psock->strp); |
161 | } |
162 | |
163 | /* Buffer limit is okay now, add to ready list */ |
164 | list_add_tail(new: &kcm->wait_rx_list, |
165 | head: &kcm->mux->kcm_rx_waiters); |
166 | /* paired with lockless reads in kcm_rfree() */ |
167 | WRITE_ONCE(kcm->rx_wait, true); |
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, size: len); |
178 | atomic_sub(i: len, v: &sk->sk_rmem_alloc); |
179 | |
180 | /* For reading rx_wait and rx_psock without holding lock */ |
181 | smp_mb__after_atomic(); |
182 | |
183 | if (!READ_ONCE(kcm->rx_wait) && !READ_ONCE(kcm->rx_psock) && |
184 | sk_rmem_alloc_get(sk) < sk->sk_rcvlowat) { |
185 | spin_lock_bh(lock: &mux->rx_lock); |
186 | kcm_rcv_ready(kcm); |
187 | spin_unlock_bh(lock: &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(v: &sk->sk_rmem_alloc) >= sk->sk_rcvbuf) |
196 | return -ENOMEM; |
197 | |
198 | if (!sk_rmem_schedule(sk, skb, size: 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(i: skb->truesize, v: &sk->sk_rmem_alloc); |
207 | sk_mem_charge(sk, size: skb->truesize); |
208 | |
209 | skb_queue_tail(list, newsk: skb); |
210 | |
211 | if (!sock_flag(sk, flag: 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 | |
226 | while ((skb = skb_dequeue(list: head))) { |
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(head: &mux->kcm_rx_waiters)) { |
232 | skb_queue_tail(list: &mux->rx_hold_queue, newsk: 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(sk: &kcm->sk, skb)) { |
240 | /* Should mean socket buffer full */ |
241 | list_del(entry: &kcm->wait_rx_list); |
242 | /* paired with lockless reads in kcm_rfree() */ |
243 | WRITE_ONCE(kcm->rx_wait, false); |
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(lock: &mux->rx_lock); |
266 | |
267 | if (psock->rx_kcm) { |
268 | spin_unlock_bh(lock: &mux->rx_lock); |
269 | return psock->rx_kcm; |
270 | } |
271 | |
272 | kcm_update_rx_mux_stats(mux, psock); |
273 | |
274 | if (list_empty(head: &mux->kcm_rx_waiters)) { |
275 | psock->ready_rx_msg = head; |
276 | strp_pause(strp: &psock->strp); |
277 | list_add_tail(new: &psock->psock_ready_list, |
278 | head: &mux->psocks_ready); |
279 | spin_unlock_bh(lock: &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(entry: &kcm->wait_rx_list); |
286 | /* paired with lockless reads in kcm_rfree() */ |
287 | WRITE_ONCE(kcm->rx_wait, false); |
288 | |
289 | psock->rx_kcm = kcm; |
290 | /* paired with lockless reads in kcm_rfree() */ |
291 | WRITE_ONCE(kcm->rx_psock, psock); |
292 | |
293 | spin_unlock_bh(lock: &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(lock: &mux->rx_lock); |
316 | |
317 | psock->rx_kcm = NULL; |
318 | /* paired with lockless reads in kcm_rfree() */ |
319 | WRITE_ONCE(kcm->rx_psock, NULL); |
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(lock: &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(work: &kcm->done_work); |
334 | return; |
335 | } |
336 | |
337 | if (unlikely(kcm->rx_disabled)) { |
338 | requeue_rx_msgs(mux, head: &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(lock: &mux->rx_lock); |
346 | } |
347 | |
348 | /* Lower sock lock held */ |
349 | static void psock_data_ready(struct sock *sk) |
350 | { |
351 | struct kcm_psock *psock; |
352 | |
353 | trace_sk_data_ready(sk); |
354 | |
355 | read_lock_bh(&sk->sk_callback_lock); |
356 | |
357 | psock = (struct kcm_psock *)sk->sk_user_data; |
358 | if (likely(psock)) |
359 | strp_data_ready(strp: &psock->strp); |
360 | |
361 | read_unlock_bh(&sk->sk_callback_lock); |
362 | } |
363 | |
364 | /* Called with lower sock held */ |
365 | static void kcm_rcv_strparser(struct strparser *strp, struct sk_buff *skb) |
366 | { |
367 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
368 | struct kcm_sock *kcm; |
369 | |
370 | try_queue: |
371 | kcm = reserve_rx_kcm(psock, head: skb); |
372 | if (!kcm) { |
373 | /* Unable to reserve a KCM, message is held in psock and strp |
374 | * is paused. |
375 | */ |
376 | return; |
377 | } |
378 | |
379 | if (kcm_queue_rcv_skb(sk: &kcm->sk, skb)) { |
380 | /* Should mean socket buffer full */ |
381 | unreserve_rx_kcm(psock, rcv_ready: false); |
382 | goto try_queue; |
383 | } |
384 | } |
385 | |
386 | static int kcm_parse_func_strparser(struct strparser *strp, struct sk_buff *skb) |
387 | { |
388 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
389 | struct bpf_prog *prog = psock->bpf_prog; |
390 | int res; |
391 | |
392 | res = bpf_prog_run_pin_on_cpu(prog, ctx: skb); |
393 | return res; |
394 | } |
395 | |
396 | static int kcm_read_sock_done(struct strparser *strp, int err) |
397 | { |
398 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
399 | |
400 | unreserve_rx_kcm(psock, rcv_ready: true); |
401 | |
402 | return err; |
403 | } |
404 | |
405 | static void psock_state_change(struct sock *sk) |
406 | { |
407 | /* TCP only does a EPOLLIN for a half close. Do a EPOLLHUP here |
408 | * since application will normally not poll with EPOLLIN |
409 | * on the TCP sockets. |
410 | */ |
411 | |
412 | report_csk_error(csk: sk, EPIPE); |
413 | } |
414 | |
415 | static void psock_write_space(struct sock *sk) |
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; |
426 | mux = psock->mux; |
427 | |
428 | spin_lock_bh(lock: &mux->lock); |
429 | |
430 | /* Check if the socket is reserved so someone is waiting for sending. */ |
431 | kcm = psock->tx_kcm; |
432 | if (kcm && !unlikely(kcm->tx_stopped)) |
433 | queue_work(wq: kcm_wq, work: &kcm->tx_work); |
434 | |
435 | spin_unlock_bh(lock: &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(lock: &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(lock: &mux->lock); |
469 | return kcm->tx_psock; |
470 | } |
471 | |
472 | if (!list_empty(head: &mux->psocks_avail)) { |
473 | psock = list_first_entry(&mux->psocks_avail, |
474 | struct kcm_psock, |
475 | psock_avail_list); |
476 | list_del(entry: &psock->psock_avail_list); |
477 | if (kcm->tx_wait) { |
478 | list_del(entry: &kcm->wait_psock_list); |
479 | kcm->tx_wait = false; |
480 | } |
481 | kcm->tx_psock = psock; |
482 | psock->tx_kcm = kcm; |
483 | KCM_STATS_INCR(psock->stats.reserved); |
484 | } else if (!kcm->tx_wait) { |
485 | list_add_tail(new: &kcm->wait_psock_list, |
486 | head: &mux->kcm_tx_waiters); |
487 | kcm->tx_wait = true; |
488 | } |
489 | |
490 | spin_unlock_bh(lock: &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(head: &mux->kcm_tx_waiters)) { |
502 | list_add_tail(new: &psock->psock_avail_list, |
503 | head: &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(entry: &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; |
518 | KCM_STATS_INCR(psock->stats.reserved); |
519 | queue_work(wq: kcm_wq, work: &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(lock: &mux->lock); |
530 | |
531 | psock = kcm->tx_psock; |
532 | |
533 | if (WARN_ON(!psock)) { |
534 | spin_unlock_bh(lock: &mux->lock); |
535 | return; |
536 | } |
537 | |
538 | smp_rmb(); /* Read tx_psock before tx_wait */ |
539 | |
540 | kcm_update_tx_mux_stats(mux, psock); |
541 | |
542 | WARN_ON(kcm->tx_wait); |
543 | |
544 | kcm->tx_psock = NULL; |
545 | psock->tx_kcm = NULL; |
546 | KCM_STATS_INCR(psock->stats.unreserved); |
547 | |
548 | if (unlikely(psock->tx_stopped)) { |
549 | if (psock->done) { |
550 | /* Deferred free */ |
551 | list_del(entry: &psock->psock_list); |
552 | mux->psocks_cnt--; |
553 | sock_put(sk: psock->sk); |
554 | fput(psock->sk->sk_socket->file); |
555 | kmem_cache_free(s: kcm_psockp, objp: psock); |
556 | } |
557 | |
558 | /* Don't put back on available list */ |
559 | |
560 | spin_unlock_bh(lock: &mux->lock); |
561 | |
562 | return; |
563 | } |
564 | |
565 | psock_now_avail(psock); |
566 | |
567 | spin_unlock_bh(lock: &mux->lock); |
568 | } |
569 | |
570 | static void kcm_report_tx_retry(struct kcm_sock *kcm) |
571 | { |
572 | struct kcm_mux *mux = kcm->mux; |
573 | |
574 | spin_lock_bh(lock: &mux->lock); |
575 | KCM_STATS_INCR(mux->stats.tx_retries); |
576 | spin_unlock_bh(lock: &mux->lock); |
577 | } |
578 | |
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 | { |
584 | unsigned int total_sent = 0; |
585 | struct sock *sk = &kcm->sk; |
586 | struct kcm_psock *psock; |
587 | struct sk_buff *head; |
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); |
597 | kcm_report_tx_retry(kcm); |
598 | if (skb_queue_empty(list: &sk->sk_write_queue)) |
599 | return 0; |
600 | |
601 | kcm_tx_msg(skb: skb_peek(list_: &sk->sk_write_queue))->started_tx = false; |
602 | } |
603 | |
604 | retry: |
605 | while ((head = skb_peek(list_: &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(skb: 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; |
628 | } |
629 | |
630 | if (WARN_ON(!skb_shinfo(skb)->nr_frags)) { |
631 | ret = -EINVAL; |
632 | goto out; |
633 | } |
634 | |
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(i: &msg.msg_iter, ITER_SOURCE, |
640 | skb_shinfo(skb)->frags, skb_shinfo(skb)->nr_frags, |
641 | count: msize); |
642 | iov_iter_advance(i: &msg.msg_iter, bytes: txm->frag_offset); |
643 | |
644 | do { |
645 | ret = sock_sendmsg(sock: psock->sk->sk_socket, msg: &msg); |
646 | if (ret <= 0) { |
647 | if (ret == -EAGAIN) { |
648 | /* Save state to try again when there's |
649 | * write space on the socket |
650 | */ |
651 | txm->frag_skb = skb; |
652 | ret = 0; |
653 | goto out; |
654 | } |
655 | |
656 | /* Hard failure in sending message, abort this |
657 | * psock since it has lost framing |
658 | * synchronization and retry sending the |
659 | * message from the beginning. |
660 | */ |
661 | kcm_abort_tx_psock(psock, err: ret ? -ret : EPIPE, |
662 | wakeup_kcm: true); |
663 | unreserve_psock(kcm); |
664 | psock = NULL; |
665 | |
666 | txm->started_tx = false; |
667 | kcm_report_tx_retry(kcm); |
668 | ret = 0; |
669 | goto retry; |
670 | } |
671 | |
672 | txm->sent += ret; |
673 | txm->frag_offset += ret; |
674 | KCM_STATS_ADD(psock->stats.tx_bytes, ret); |
675 | } while (msg.msg_iter.count > 0); |
676 | |
677 | if (skb == head) { |
678 | if (skb_has_frag_list(skb)) { |
679 | txm->frag_skb = skb_shinfo(skb)->frag_list; |
680 | txm->frag_offset = 0; |
681 | continue; |
682 | } |
683 | } else if (skb->next) { |
684 | txm->frag_skb = skb->next; |
685 | txm->frag_offset = 0; |
686 | continue; |
687 | } |
688 | |
689 | /* Successfully sent the whole packet, account for it. */ |
690 | sk->sk_wmem_queued -= txm->sent; |
691 | total_sent += txm->sent; |
692 | skb_dequeue(list: &sk->sk_write_queue); |
693 | kfree_skb(skb: head); |
694 | KCM_STATS_INCR(psock->stats.tx_msgs); |
695 | } |
696 | out: |
697 | if (!head) { |
698 | /* Done with all queued messages. */ |
699 | WARN_ON(!skb_queue_empty(&sk->sk_write_queue)); |
700 | if (psock) |
701 | unreserve_psock(kcm); |
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(csk: &kcm->sk, err: -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, addr: &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, noblock: 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(skb: 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, addr: &sk->sk_socket->flags); |
776 | err = sk_stream_wait_memory(sk, timeo_p: &timeo); |
777 | if (err) |
778 | goto out_error; |
779 | } |
780 | |
781 | if (msg_data_left(msg)) { |
782 | /* New message, alloc head skb */ |
783 | head = alloc_skb(size: 0, priority: sk->sk_allocation); |
784 | while (!head) { |
785 | kcm_push(kcm); |
786 | err = sk_stream_wait_memory(sk, timeo_p: &timeo); |
787 | if (err) |
788 | goto out_error; |
789 | |
790 | head = alloc_skb(size: 0, priority: sk->sk_allocation); |
791 | } |
792 | |
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 | } |
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, page: pfrag->page, |
811 | off: pfrag->offset)) { |
812 | if (i == MAX_SKB_FRAGS) { |
813 | struct sk_buff *tskb; |
814 | |
815 | tskb = alloc_skb(size: 0, priority: 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 | |
831 | if (msg->msg_flags & MSG_SPLICE_PAGES) { |
832 | copy = msg_data_left(msg); |
833 | if (!sk_wmem_schedule(sk, size: copy)) |
834 | goto wait_for_memory; |
835 | |
836 | err = skb_splice_from_iter(skb, iter: &msg->msg_iter, maxsize: copy, |
837 | gfp: sk->sk_allocation); |
838 | if (err < 0) { |
839 | if (err == -EMSGSIZE) |
840 | goto wait_for_memory; |
841 | goto out_error; |
842 | } |
843 | |
844 | copy = err; |
845 | skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG; |
846 | sk_wmem_queued_add(sk, val: copy); |
847 | sk_mem_charge(sk, size: copy); |
848 | |
849 | if (head != skb) |
850 | head->truesize += copy; |
851 | } else { |
852 | copy = min_t(int, msg_data_left(msg), |
853 | pfrag->size - pfrag->offset); |
854 | if (!sk_wmem_schedule(sk, size: copy)) |
855 | goto wait_for_memory; |
856 | |
857 | err = skb_copy_to_page_nocache(sk, from: &msg->msg_iter, skb, |
858 | page: pfrag->page, |
859 | off: 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 | frag: &skb_shinfo(skb)->frags[i - 1], delta: copy); |
868 | } else { |
869 | skb_fill_page_desc(skb, i, page: pfrag->page, |
870 | off: pfrag->offset, size: copy); |
871 | get_page(page: pfrag->page); |
872 | } |
873 | |
874 | pfrag->offset += copy; |
875 | } |
876 | |
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_p: &timeo); |
888 | if (err) |
889 | goto out_error; |
890 | } |
891 | |
892 | if (eor) { |
893 | bool not_busy = skb_queue_empty(list: &sk->sk_write_queue); |
894 | |
895 | if (head) { |
896 | /* Message complete, queue it on send buffer */ |
897 | __skb_queue_tail(list: &sk->sk_write_queue, newsk: head); |
898 | kcm->seq_skb = NULL; |
899 | KCM_STATS_INCR(kcm->stats.tx_msgs); |
900 | } |
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(csk: &kcm->sk, err: -err); |
914 | } |
915 | } |
916 | } else { |
917 | /* Message not complete, save state */ |
918 | partial_message: |
919 | if (head) { |
920 | kcm->seq_skb = head; |
921 | kcm_tx_msg(skb: head)->last_skb = skb; |
922 | } |
923 | } |
924 | |
925 | KCM_STATS_ADD(kcm->stats.tx_bytes, copied); |
926 | |
927 | release_sock(sk); |
928 | return copied; |
929 | |
930 | out_error: |
931 | kcm_push(kcm); |
932 | |
933 | if (sock->type == SOCK_SEQPACKET) { |
934 | /* Wrote some bytes before encountering an |
935 | * error, return partial success. |
936 | */ |
937 | if (copied) |
938 | goto partial_message; |
939 | if (head != kcm->seq_skb) |
940 | kfree_skb(skb: head); |
941 | } else { |
942 | kfree_skb(skb: head); |
943 | kcm->seq_skb = NULL; |
944 | } |
945 | |
946 | err = sk_stream_error(sk, flags: 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 | |
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(list: &sk->sk_write_queue)) |
962 | return; |
963 | |
964 | lock_sock(sk); |
965 | kcm_write_msgs(kcm); |
966 | release_sock(sk); |
967 | } |
968 | |
969 | static int kcm_recvmsg(struct socket *sock, struct msghdr *msg, |
970 | size_t len, int flags) |
971 | { |
972 | struct sock *sk = sock->sk; |
973 | struct kcm_sock *kcm = kcm_sk(sk); |
974 | int err = 0; |
975 | struct strp_msg *stm; |
976 | int copied = 0; |
977 | struct sk_buff *skb; |
978 | |
979 | skb = skb_recv_datagram(sk, flags, err: &err); |
980 | if (!skb) |
981 | goto out; |
982 | |
983 | /* Okay, have a message on the receive queue */ |
984 | |
985 | stm = strp_msg(skb); |
986 | |
987 | if (len > stm->full_len) |
988 | len = stm->full_len; |
989 | |
990 | err = skb_copy_datagram_msg(from: skb, offset: stm->offset, msg, size: len); |
991 | if (err < 0) |
992 | goto out; |
993 | |
994 | copied = len; |
995 | if (likely(!(flags & MSG_PEEK))) { |
996 | KCM_STATS_ADD(kcm->stats.rx_bytes, copied); |
997 | if (copied < stm->full_len) { |
998 | if (sock->type == SOCK_DGRAM) { |
999 | /* Truncated message */ |
1000 | msg->msg_flags |= MSG_TRUNC; |
1001 | goto msg_finished; |
1002 | } |
1003 | stm->offset += copied; |
1004 | stm->full_len -= copied; |
1005 | } else { |
1006 | msg_finished: |
1007 | /* Finished with message */ |
1008 | msg->msg_flags |= MSG_EOR; |
1009 | KCM_STATS_INCR(kcm->stats.rx_msgs); |
1010 | } |
1011 | } |
1012 | |
1013 | out: |
1014 | skb_free_datagram(sk, skb); |
1015 | return copied ? : err; |
1016 | } |
1017 | |
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); |
1024 | struct strp_msg *stm; |
1025 | int err = 0; |
1026 | ssize_t copied; |
1027 | struct sk_buff *skb; |
1028 | |
1029 | /* Only support splice for SOCKSEQPACKET */ |
1030 | |
1031 | skb = skb_recv_datagram(sk, flags, err: &err); |
1032 | if (!skb) |
1033 | goto err_out; |
1034 | |
1035 | /* Okay, have a message on the receive queue */ |
1036 | |
1037 | stm = strp_msg(skb); |
1038 | |
1039 | if (len > stm->full_len) |
1040 | len = stm->full_len; |
1041 | |
1042 | copied = skb_splice_bits(skb, sk, offset: stm->offset, pipe, len, flags); |
1043 | if (copied < 0) { |
1044 | err = copied; |
1045 | goto err_out; |
1046 | } |
1047 | |
1048 | KCM_STATS_ADD(kcm->stats.rx_bytes, copied); |
1049 | |
1050 | stm->offset += copied; |
1051 | stm->full_len -= copied; |
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 | |
1059 | skb_free_datagram(sk, skb); |
1060 | return copied; |
1061 | |
1062 | err_out: |
1063 | skb_free_datagram(sk, skb); |
1064 | return err; |
1065 | } |
1066 | |
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(lock: &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(entry: &kcm->wait_rx_list); |
1083 | /* paired with lockless reads in kcm_rfree() */ |
1084 | WRITE_ONCE(kcm->rx_wait, false); |
1085 | } |
1086 | |
1087 | requeue_rx_msgs(mux, head: &kcm->sk.sk_receive_queue); |
1088 | } |
1089 | |
1090 | spin_unlock_bh(lock: &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(lock: &mux->rx_lock); |
1102 | |
1103 | kcm->rx_disabled = 0; |
1104 | kcm_rcv_ready(kcm); |
1105 | |
1106 | spin_unlock_bh(lock: &mux->rx_lock); |
1107 | } |
1108 | |
1109 | static int kcm_setsockopt(struct socket *sock, int level, int optname, |
1110 | sockptr_t optval, unsigned int optlen) |
1111 | { |
1112 | struct kcm_sock *kcm = kcm_sk(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 | |
1122 | if (copy_from_sockptr(dst: &val, src: optval, size: sizeof(int))) |
1123 | return -EFAULT; |
1124 | |
1125 | valbool = val ? 1 : 0; |
1126 | |
1127 | switch (optname) { |
1128 | case KCM_RECV_DISABLE: |
1129 | lock_sock(sk: &kcm->sk); |
1130 | if (valbool) |
1131 | kcm_recv_disable(kcm); |
1132 | else |
1133 | kcm_recv_enable(kcm); |
1134 | release_sock(sk: &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(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(to: optval, from: &val, n: 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 | |
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 |
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(lock: &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(new: &kcm->kcm_sock_list, head); |
1199 | kcm->index = index; |
1200 | |
1201 | mux->kcm_socks_cnt++; |
1202 | spin_unlock_bh(lock: &mux->lock); |
1203 | |
1204 | INIT_WORK(&kcm->tx_work, kcm_tx_work); |
1205 | |
1206 | spin_lock_bh(lock: &mux->rx_lock); |
1207 | kcm_rcv_ready(kcm); |
1208 | spin_unlock_bh(lock: &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(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; |
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 | }; |
1225 | int err = 0; |
1226 | |
1227 | csk = csock->sk; |
1228 | if (!csk) |
1229 | return -EINVAL; |
1230 | |
1231 | lock_sock(sk: csk); |
1232 | |
1233 | /* Only allow TCP sockets to be attached for now */ |
1234 | if ((csk->sk_family != AF_INET && csk->sk_family != AF_INET6) || |
1235 | csk->sk_protocol != IPPROTO_TCP) { |
1236 | err = -EOPNOTSUPP; |
1237 | goto out; |
1238 | } |
1239 | |
1240 | /* Don't allow listeners or closed sockets */ |
1241 | if (csk->sk_state == TCP_LISTEN || csk->sk_state == TCP_CLOSE) { |
1242 | err = -EOPNOTSUPP; |
1243 | goto out; |
1244 | } |
1245 | |
1246 | psock = kmem_cache_zalloc(k: kcm_psockp, GFP_KERNEL); |
1247 | if (!psock) { |
1248 | err = -ENOMEM; |
1249 | goto out; |
1250 | } |
1251 | |
1252 | psock->mux = mux; |
1253 | psock->sk = csk; |
1254 | psock->bpf_prog = prog; |
1255 | |
1256 | write_lock_bh(&csk->sk_callback_lock); |
1257 | |
1258 | /* Check if sk_user_data is already by KCM or someone else. |
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); |
1263 | kmem_cache_free(s: kcm_psockp, objp: psock); |
1264 | err = -EALREADY; |
1265 | goto out; |
1266 | } |
1267 | |
1268 | err = strp_init(strp: &psock->strp, sk: csk, cb: &cb); |
1269 | if (err) { |
1270 | write_unlock_bh(&csk->sk_callback_lock); |
1271 | kmem_cache_free(s: kcm_psockp, objp: psock); |
1272 | goto out; |
1273 | } |
1274 | |
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; |
1279 | csk->sk_data_ready = psock_data_ready; |
1280 | csk->sk_write_space = psock_write_space; |
1281 | csk->sk_state_change = psock_state_change; |
1282 | |
1283 | write_unlock_bh(&csk->sk_callback_lock); |
1284 | |
1285 | sock_hold(sk: csk); |
1286 | |
1287 | /* Finished initialization, now add the psock to the MUX. */ |
1288 | spin_lock_bh(lock: &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(new: &psock->psock_list, head); |
1298 | psock->index = index; |
1299 | |
1300 | KCM_STATS_INCR(mux->stats.psock_attach); |
1301 | mux->psocks_cnt++; |
1302 | psock_now_avail(psock); |
1303 | spin_unlock_bh(lock: &mux->lock); |
1304 | |
1305 | /* Schedule RX work in case there are already bytes queued */ |
1306 | strp_check_rcv(strp: &psock->strp); |
1307 | |
1308 | out: |
1309 | release_sock(sk: csk); |
1310 | |
1311 | return err; |
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(fd: info->fd, err: &err); |
1321 | if (!csock) |
1322 | return -ENOENT; |
1323 | |
1324 | prog = bpf_prog_get_type(ufd: info->bpf_fd, type: BPF_PROG_TYPE_SOCKET_FILTER); |
1325 | if (IS_ERR(ptr: prog)) { |
1326 | err = PTR_ERR(ptr: prog); |
1327 | goto out; |
1328 | } |
1329 | |
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: |
1340 | sockfd_put(csock); |
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 | |
1349 | lock_sock(sk: csk); |
1350 | |
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; |
1359 | strp_stop(strp: &psock->strp); |
1360 | |
1361 | if (WARN_ON(psock->rx_kcm)) { |
1362 | write_unlock_bh(&csk->sk_callback_lock); |
1363 | release_sock(sk: csk); |
1364 | return; |
1365 | } |
1366 | |
1367 | spin_lock_bh(lock: &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(entry: &psock->psock_ready_list); |
1374 | kfree_skb(skb: psock->ready_rx_msg); |
1375 | psock->ready_rx_msg = NULL; |
1376 | KCM_STATS_INCR(mux->stats.rx_ready_drops); |
1377 | } |
1378 | |
1379 | spin_unlock_bh(lock: &mux->rx_lock); |
1380 | |
1381 | write_unlock_bh(&csk->sk_callback_lock); |
1382 | |
1383 | /* Call strp_done without sock lock */ |
1384 | release_sock(sk: csk); |
1385 | strp_done(strp: &psock->strp); |
1386 | lock_sock(sk: csk); |
1387 | |
1388 | bpf_prog_put(prog: psock->bpf_prog); |
1389 | |
1390 | spin_lock_bh(lock: &mux->lock); |
1391 | |
1392 | aggregate_psock_stats(stats: &psock->stats, agg_stats: &mux->aggregate_psock_stats); |
1393 | save_strp_stats(strp: &psock->strp, agg_stats: &mux->aggregate_strp_stats); |
1394 | |
1395 | KCM_STATS_INCR(mux->stats.psock_unattach); |
1396 | |
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 | */ |
1402 | KCM_STATS_INCR(mux->stats.psock_unattach_rsvd); |
1403 | spin_unlock_bh(lock: &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, wakeup_kcm: false); |
1410 | |
1411 | spin_lock_bh(lock: &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(wq: kcm_wq, work: &psock->tx_kcm->tx_work); |
1423 | spin_unlock_bh(lock: &mux->lock); |
1424 | } else { |
1425 | no_reserved: |
1426 | if (!psock->tx_stopped) |
1427 | list_del(entry: &psock->psock_avail_list); |
1428 | list_del(entry: &psock->psock_list); |
1429 | mux->psocks_cnt--; |
1430 | spin_unlock_bh(lock: &mux->lock); |
1431 | |
1432 | sock_put(sk: csk); |
1433 | fput(csk->sk_socket->file); |
1434 | kmem_cache_free(s: kcm_psockp, objp: psock); |
1435 | } |
1436 | |
1437 | release_sock(sk: csk); |
1438 | } |
1439 | |
1440 | static int kcm_unattach_ioctl(struct socket *sock, struct kcm_unattach *info) |
1441 | { |
1442 | struct kcm_sock *kcm = kcm_sk(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(fd: info->fd, err: &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(lock: &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(lock: &mux->lock); |
1477 | |
1478 | /* Lower socket lock should already be held */ |
1479 | kcm_unattach(psock); |
1480 | |
1481 | err = 0; |
1482 | goto out; |
1483 | } |
1484 | |
1485 | spin_unlock_bh(lock: &mux->lock); |
1486 | |
1487 | out: |
1488 | sockfd_put(csock); |
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. */ |
1499 | static struct file *kcm_clone(struct socket *osock) |
1500 | { |
1501 | struct socket *newsock; |
1502 | struct sock *newsk; |
1503 | |
1504 | newsock = sock_alloc(); |
1505 | if (!newsock) |
1506 | return ERR_PTR(error: -ENFILE); |
1507 | |
1508 | newsock->type = osock->type; |
1509 | newsock->ops = osock->ops; |
1510 | |
1511 | __module_get(module: newsock->ops->owner); |
1512 | |
1513 | newsk = sk_alloc(net: sock_net(sk: osock->sk), PF_KCM, GFP_KERNEL, |
1514 | prot: &kcm_proto, kern: false); |
1515 | if (!newsk) { |
1516 | sock_release(sock: newsock); |
1517 | return ERR_PTR(error: -ENOMEM); |
1518 | } |
1519 | sock_init_data(sock: newsock, sk: newsk); |
1520 | init_kcm_sock(kcm: kcm_sk(sk: newsk), mux: kcm_sk(sk: osock->sk)->mux); |
1521 | |
1522 | return sock_alloc_file(sock: newsock, flags: 0, dname: osock->sk->sk_prot_creator->name); |
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(to: &info, from: (void __user *)arg, n: sizeof(info))) |
1534 | return -EFAULT; |
1535 | |
1536 | err = kcm_attach_ioctl(sock, info: &info); |
1537 | |
1538 | break; |
1539 | } |
1540 | case SIOCKCMUNATTACH: { |
1541 | struct kcm_unattach info; |
1542 | |
1543 | if (copy_from_user(to: &info, from: (void __user *)arg, n: sizeof(info))) |
1544 | return -EFAULT; |
1545 | |
1546 | err = kcm_unattach_ioctl(sock, info: &info); |
1547 | |
1548 | break; |
1549 | } |
1550 | case SIOCKCMCLONE: { |
1551 | struct kcm_clone info; |
1552 | struct file *file; |
1553 | |
1554 | info.fd = get_unused_fd_flags(flags: 0); |
1555 | if (unlikely(info.fd < 0)) |
1556 | return info.fd; |
1557 | |
1558 | file = kcm_clone(osock: sock); |
1559 | if (IS_ERR(ptr: file)) { |
1560 | put_unused_fd(fd: info.fd); |
1561 | return PTR_ERR(ptr: file); |
1562 | } |
1563 | if (copy_to_user(to: (void __user *)arg, from: &info, |
1564 | n: sizeof(info))) { |
1565 | put_unused_fd(fd: info.fd); |
1566 | fput(file); |
1567 | return -EFAULT; |
1568 | } |
1569 | fd_install(fd: info.fd, file); |
1570 | err = 0; |
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(s: kcm_muxp, objp: 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) { |
1597 | if (!WARN_ON(psock->unattaching)) |
1598 | kcm_unattach(psock); |
1599 | } |
1600 | |
1601 | if (WARN_ON(mux->psocks_cnt)) |
1602 | return; |
1603 | |
1604 | __skb_queue_purge(list: &mux->rx_hold_queue); |
1605 | |
1606 | mutex_lock(&knet->mutex); |
1607 | aggregate_mux_stats(stats: &mux->stats, agg_stats: &knet->aggregate_mux_stats); |
1608 | aggregate_psock_stats(stats: &mux->aggregate_psock_stats, |
1609 | agg_stats: &knet->aggregate_psock_stats); |
1610 | aggregate_strp_stats(stats: &mux->aggregate_strp_stats, |
1611 | agg_stats: &knet->aggregate_strp_stats); |
1612 | list_del_rcu(entry: &mux->kcm_mux_list); |
1613 | knet->count--; |
1614 | mutex_unlock(lock: &knet->mutex); |
1615 | |
1616 | call_rcu(head: &mux->rcu, func: 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(lock: &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(lock: &mux->rx_lock); |
1632 | return; |
1633 | } |
1634 | |
1635 | if (kcm->rx_wait) { |
1636 | list_del(entry: &kcm->wait_rx_list); |
1637 | /* paired with lockless reads in kcm_rfree() */ |
1638 | WRITE_ONCE(kcm->rx_wait, false); |
1639 | } |
1640 | /* Move any pending receive messages to other kcm sockets */ |
1641 | requeue_rx_msgs(mux, head: &sk->sk_receive_queue); |
1642 | |
1643 | spin_unlock_bh(lock: &mux->rx_lock); |
1644 | |
1645 | if (WARN_ON(sk_rmem_alloc_get(sk))) |
1646 | return; |
1647 | |
1648 | /* Detach from MUX */ |
1649 | spin_lock_bh(lock: &mux->lock); |
1650 | |
1651 | list_del(entry: &kcm->kcm_sock_list); |
1652 | mux->kcm_socks_cnt--; |
1653 | socks_cnt = mux->kcm_socks_cnt; |
1654 | |
1655 | spin_unlock_bh(lock: &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(sk: &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 | |
1683 | lock_sock(sk); |
1684 | sock_orphan(sk); |
1685 | kfree_skb(skb: kcm->seq_skb); |
1686 | |
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(list: &sk->sk_write_queue); |
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 | |
1699 | release_sock(sk); |
1700 | |
1701 | spin_lock_bh(lock: &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(entry: &kcm->wait_psock_list); |
1707 | kcm->tx_wait = false; |
1708 | } |
1709 | spin_unlock_bh(lock: &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(work: &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, wakeup_kcm: 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 | |
1738 | static const struct proto_ops kcm_dgram_ops = { |
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, |
1747 | .poll = datagram_poll, |
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, |
1756 | .splice_eof = kcm_splice_eof, |
1757 | }; |
1758 | |
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, |
1768 | .poll = datagram_poll, |
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, |
1777 | .splice_eof = kcm_splice_eof, |
1778 | .splice_read = kcm_splice_read, |
1779 | }; |
1780 | |
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, id: kcm_net_id); |
1786 | struct sock *sk; |
1787 | struct kcm_mux *mux; |
1788 | |
1789 | switch (sock->type) { |
1790 | case SOCK_DGRAM: |
1791 | sock->ops = &kcm_dgram_ops; |
1792 | break; |
1793 | case SOCK_SEQPACKET: |
1794 | sock->ops = &kcm_seqpacket_ops; |
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, prot: &kcm_proto, kern); |
1804 | if (!sk) |
1805 | return -ENOMEM; |
1806 | |
1807 | /* Allocate a kcm mux, shared between KCM sockets */ |
1808 | mux = kmem_cache_zalloc(k: 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(list: &mux->kcm_socks); |
1817 | INIT_LIST_HEAD(list: &mux->kcm_rx_waiters); |
1818 | INIT_LIST_HEAD(list: &mux->kcm_tx_waiters); |
1819 | |
1820 | INIT_LIST_HEAD(list: &mux->psocks); |
1821 | INIT_LIST_HEAD(list: &mux->psocks_ready); |
1822 | INIT_LIST_HEAD(list: &mux->psocks_avail); |
1823 | |
1824 | mux->knet = knet; |
1825 | |
1826 | /* Add new MUX to list */ |
1827 | mutex_lock(&knet->mutex); |
1828 | list_add_rcu(new: &mux->kcm_mux_list, head: &knet->mux_list); |
1829 | knet->count++; |
1830 | mutex_unlock(lock: &knet->mutex); |
1831 | |
1832 | skb_queue_head_init(list: &mux->rx_hold_queue); |
1833 | |
1834 | /* Init KCM socket */ |
1835 | sock_init_data(sock, sk); |
1836 | init_kcm_sock(kcm: kcm_sk(sk), mux); |
1837 | |
1838 | return 0; |
1839 | } |
1840 | |
1841 | static const struct net_proto_family kcm_family_ops = { |
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, id: kcm_net_id); |
1850 | |
1851 | INIT_LIST_HEAD_RCU(list: &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, id: 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)); |
1865 | |
1866 | mutex_destroy(lock: &knet->mutex); |
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(name: "kcm_mux_cache" , |
1881 | size: sizeof(struct kcm_mux), align: 0, |
1882 | SLAB_HWCACHE_ALIGN, NULL); |
1883 | if (!kcm_muxp) |
1884 | goto fail; |
1885 | |
1886 | kcm_psockp = kmem_cache_create(name: "kcm_psock_cache" , |
1887 | size: sizeof(struct kcm_psock), align: 0, |
1888 | SLAB_HWCACHE_ALIGN, NULL); |
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(prot: &kcm_proto, alloc_slab: 1); |
1897 | if (err) |
1898 | goto fail; |
1899 | |
1900 | err = register_pernet_device(&kcm_net_ops); |
1901 | if (err) |
1902 | goto net_ops_fail; |
1903 | |
1904 | err = sock_register(fam: &kcm_family_ops); |
1905 | if (err) |
1906 | goto sock_register_fail; |
1907 | |
1908 | err = kcm_proc_init(); |
1909 | if (err) |
1910 | goto proc_init_fail; |
1911 | |
1912 | return 0; |
1913 | |
1914 | proc_init_fail: |
1915 | sock_unregister(PF_KCM); |
1916 | |
1917 | sock_register_fail: |
1918 | unregister_pernet_device(&kcm_net_ops); |
1919 | |
1920 | net_ops_fail: |
1921 | proto_unregister(prot: &kcm_proto); |
1922 | |
1923 | fail: |
1924 | kmem_cache_destroy(s: kcm_muxp); |
1925 | kmem_cache_destroy(s: kcm_psockp); |
1926 | |
1927 | if (kcm_wq) |
1928 | destroy_workqueue(wq: kcm_wq); |
1929 | |
1930 | return err; |
1931 | } |
1932 | |
1933 | static void __exit kcm_exit(void) |
1934 | { |
1935 | kcm_proc_exit(); |
1936 | sock_unregister(PF_KCM); |
1937 | unregister_pernet_device(&kcm_net_ops); |
1938 | proto_unregister(prot: &kcm_proto); |
1939 | destroy_workqueue(wq: kcm_wq); |
1940 | |
1941 | kmem_cache_destroy(s: kcm_muxp); |
1942 | kmem_cache_destroy(s: 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); |
1950 | |