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> | |
12 | #include <linux/in.h> | |
13 | #include <linux/kernel.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/net.h> | |
16 | #include <linux/netdevice.h> | |
17 | #include <linux/poll.h> | |
18 | #include <linux/rculist.h> | |
19 | #include <linux/skbuff.h> | |
20 | #include <linux/socket.h> | |
21 | #include <linux/uaccess.h> | |
22 | #include <linux/workqueue.h> | |
c0338aff | 23 | #include <linux/syscalls.h> |
174cd4b1 IM |
24 | #include <linux/sched/signal.h> |
25 | ||
ab7ac4eb TH |
26 | #include <net/kcm.h> |
27 | #include <net/netns/generic.h> | |
28 | #include <net/sock.h> | |
ab7ac4eb TH |
29 | #include <uapi/linux/kcm.h> |
30 | ||
31 | unsigned int kcm_net_id; | |
32 | ||
33 | static struct kmem_cache *kcm_psockp __read_mostly; | |
34 | static struct kmem_cache *kcm_muxp __read_mostly; | |
35 | static struct workqueue_struct *kcm_wq; | |
36 | ||
37 | static inline struct kcm_sock *kcm_sk(const struct sock *sk) | |
38 | { | |
39 | return (struct kcm_sock *)sk; | |
40 | } | |
41 | ||
42 | static inline struct kcm_tx_msg *kcm_tx_msg(struct sk_buff *skb) | |
43 | { | |
44 | return (struct kcm_tx_msg *)skb->cb; | |
45 | } | |
46 | ||
ab7ac4eb TH |
47 | static void report_csk_error(struct sock *csk, int err) |
48 | { | |
49 | csk->sk_err = EPIPE; | |
50 | csk->sk_error_report(csk); | |
51 | } | |
52 | ||
ab7ac4eb TH |
53 | static void kcm_abort_tx_psock(struct kcm_psock *psock, int err, |
54 | bool wakeup_kcm) | |
55 | { | |
56 | struct sock *csk = psock->sk; | |
57 | struct kcm_mux *mux = psock->mux; | |
58 | ||
59 | /* Unrecoverable error in transmit */ | |
60 | ||
61 | spin_lock_bh(&mux->lock); | |
62 | ||
63 | if (psock->tx_stopped) { | |
64 | spin_unlock_bh(&mux->lock); | |
65 | return; | |
66 | } | |
67 | ||
68 | psock->tx_stopped = 1; | |
cd6e111b | 69 | KCM_STATS_INCR(psock->stats.tx_aborts); |
ab7ac4eb TH |
70 | |
71 | if (!psock->tx_kcm) { | |
72 | /* Take off psocks_avail list */ | |
73 | list_del(&psock->psock_avail_list); | |
74 | } else if (wakeup_kcm) { | |
75 | /* In this case psock is being aborted while outside of | |
76 | * write_msgs and psock is reserved. Schedule tx_work | |
77 | * to handle the failure there. Need to commit tx_stopped | |
78 | * before queuing work. | |
79 | */ | |
80 | smp_mb(); | |
81 | ||
82 | queue_work(kcm_wq, &psock->tx_kcm->tx_work); | |
83 | } | |
84 | ||
85 | spin_unlock_bh(&mux->lock); | |
86 | ||
87 | /* Report error on lower socket */ | |
88 | report_csk_error(csk, err); | |
89 | } | |
90 | ||
cd6e111b TH |
91 | /* RX mux lock held. */ |
92 | static void kcm_update_rx_mux_stats(struct kcm_mux *mux, | |
93 | struct kcm_psock *psock) | |
94 | { | |
9b73896a | 95 | STRP_STATS_ADD(mux->stats.rx_bytes, |
bbb03029 | 96 | psock->strp.stats.bytes - |
9b73896a | 97 | psock->saved_rx_bytes); |
cd6e111b | 98 | mux->stats.rx_msgs += |
bbb03029 TH |
99 | psock->strp.stats.msgs - psock->saved_rx_msgs; |
100 | psock->saved_rx_msgs = psock->strp.stats.msgs; | |
101 | psock->saved_rx_bytes = psock->strp.stats.bytes; | |
cd6e111b TH |
102 | } |
103 | ||
104 | static void kcm_update_tx_mux_stats(struct kcm_mux *mux, | |
105 | struct kcm_psock *psock) | |
106 | { | |
107 | KCM_STATS_ADD(mux->stats.tx_bytes, | |
108 | psock->stats.tx_bytes - psock->saved_tx_bytes); | |
109 | mux->stats.tx_msgs += | |
110 | psock->stats.tx_msgs - psock->saved_tx_msgs; | |
111 | psock->saved_tx_msgs = psock->stats.tx_msgs; | |
112 | psock->saved_tx_bytes = psock->stats.tx_bytes; | |
113 | } | |
114 | ||
ab7ac4eb TH |
115 | static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); |
116 | ||
117 | /* KCM is ready to receive messages on its queue-- either the KCM is new or | |
118 | * has become unblocked after being blocked on full socket buffer. Queue any | |
119 | * pending ready messages on a psock. RX mux lock held. | |
120 | */ | |
121 | static void kcm_rcv_ready(struct kcm_sock *kcm) | |
122 | { | |
123 | struct kcm_mux *mux = kcm->mux; | |
124 | struct kcm_psock *psock; | |
125 | struct sk_buff *skb; | |
126 | ||
127 | if (unlikely(kcm->rx_wait || kcm->rx_psock || kcm->rx_disabled)) | |
128 | return; | |
129 | ||
130 | while (unlikely((skb = __skb_dequeue(&mux->rx_hold_queue)))) { | |
131 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { | |
132 | /* Assuming buffer limit has been reached */ | |
133 | skb_queue_head(&mux->rx_hold_queue, skb); | |
134 | WARN_ON(!sk_rmem_alloc_get(&kcm->sk)); | |
135 | return; | |
136 | } | |
137 | } | |
138 | ||
139 | while (!list_empty(&mux->psocks_ready)) { | |
140 | psock = list_first_entry(&mux->psocks_ready, struct kcm_psock, | |
141 | psock_ready_list); | |
142 | ||
143 | if (kcm_queue_rcv_skb(&kcm->sk, psock->ready_rx_msg)) { | |
144 | /* Assuming buffer limit has been reached */ | |
145 | WARN_ON(!sk_rmem_alloc_get(&kcm->sk)); | |
146 | return; | |
147 | } | |
148 | ||
149 | /* Consumed the ready message on the psock. Schedule rx_work to | |
150 | * get more messages. | |
151 | */ | |
152 | list_del(&psock->psock_ready_list); | |
153 | psock->ready_rx_msg = NULL; | |
ab7ac4eb TH |
154 | /* Commit clearing of ready_rx_msg for queuing work */ |
155 | smp_mb(); | |
156 | ||
9b73896a TH |
157 | strp_unpause(&psock->strp); |
158 | strp_check_rcv(&psock->strp); | |
ab7ac4eb TH |
159 | } |
160 | ||
161 | /* Buffer limit is okay now, add to ready list */ | |
162 | list_add_tail(&kcm->wait_rx_list, | |
163 | &kcm->mux->kcm_rx_waiters); | |
164 | kcm->rx_wait = true; | |
165 | } | |
166 | ||
167 | static void kcm_rfree(struct sk_buff *skb) | |
168 | { | |
169 | struct sock *sk = skb->sk; | |
170 | struct kcm_sock *kcm = kcm_sk(sk); | |
171 | struct kcm_mux *mux = kcm->mux; | |
172 | unsigned int len = skb->truesize; | |
173 | ||
174 | sk_mem_uncharge(sk, len); | |
175 | atomic_sub(len, &sk->sk_rmem_alloc); | |
176 | ||
177 | /* For reading rx_wait and rx_psock without holding lock */ | |
178 | smp_mb__after_atomic(); | |
179 | ||
180 | if (!kcm->rx_wait && !kcm->rx_psock && | |
181 | sk_rmem_alloc_get(sk) < sk->sk_rcvlowat) { | |
182 | spin_lock_bh(&mux->rx_lock); | |
183 | kcm_rcv_ready(kcm); | |
184 | spin_unlock_bh(&mux->rx_lock); | |
185 | } | |
186 | } | |
187 | ||
188 | static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) | |
189 | { | |
190 | struct sk_buff_head *list = &sk->sk_receive_queue; | |
191 | ||
192 | if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) | |
193 | return -ENOMEM; | |
194 | ||
195 | if (!sk_rmem_schedule(sk, skb, skb->truesize)) | |
196 | return -ENOBUFS; | |
197 | ||
198 | skb->dev = NULL; | |
199 | ||
200 | skb_orphan(skb); | |
201 | skb->sk = sk; | |
202 | skb->destructor = kcm_rfree; | |
203 | atomic_add(skb->truesize, &sk->sk_rmem_alloc); | |
204 | sk_mem_charge(sk, skb->truesize); | |
205 | ||
206 | skb_queue_tail(list, skb); | |
207 | ||
208 | if (!sock_flag(sk, SOCK_DEAD)) | |
209 | sk->sk_data_ready(sk); | |
210 | ||
211 | return 0; | |
212 | } | |
213 | ||
214 | /* Requeue received messages for a kcm socket to other kcm sockets. This is | |
215 | * called with a kcm socket is receive disabled. | |
216 | * RX mux lock held. | |
217 | */ | |
218 | static void requeue_rx_msgs(struct kcm_mux *mux, struct sk_buff_head *head) | |
219 | { | |
220 | struct sk_buff *skb; | |
221 | struct kcm_sock *kcm; | |
222 | ||
223 | while ((skb = __skb_dequeue(head))) { | |
224 | /* Reset destructor to avoid calling kcm_rcv_ready */ | |
225 | skb->destructor = sock_rfree; | |
226 | skb_orphan(skb); | |
227 | try_again: | |
228 | if (list_empty(&mux->kcm_rx_waiters)) { | |
229 | skb_queue_tail(&mux->rx_hold_queue, skb); | |
230 | continue; | |
231 | } | |
232 | ||
233 | kcm = list_first_entry(&mux->kcm_rx_waiters, | |
234 | struct kcm_sock, wait_rx_list); | |
235 | ||
236 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { | |
237 | /* Should mean socket buffer full */ | |
238 | list_del(&kcm->wait_rx_list); | |
239 | kcm->rx_wait = false; | |
240 | ||
241 | /* Commit rx_wait to read in kcm_free */ | |
242 | smp_wmb(); | |
243 | ||
244 | goto try_again; | |
245 | } | |
246 | } | |
247 | } | |
248 | ||
249 | /* Lower sock lock held */ | |
250 | static struct kcm_sock *reserve_rx_kcm(struct kcm_psock *psock, | |
251 | struct sk_buff *head) | |
252 | { | |
253 | struct kcm_mux *mux = psock->mux; | |
254 | struct kcm_sock *kcm; | |
255 | ||
256 | WARN_ON(psock->ready_rx_msg); | |
257 | ||
258 | if (psock->rx_kcm) | |
259 | return psock->rx_kcm; | |
260 | ||
261 | spin_lock_bh(&mux->rx_lock); | |
262 | ||
263 | if (psock->rx_kcm) { | |
264 | spin_unlock_bh(&mux->rx_lock); | |
265 | return psock->rx_kcm; | |
266 | } | |
267 | ||
cd6e111b TH |
268 | kcm_update_rx_mux_stats(mux, psock); |
269 | ||
ab7ac4eb TH |
270 | if (list_empty(&mux->kcm_rx_waiters)) { |
271 | psock->ready_rx_msg = head; | |
9b73896a | 272 | strp_pause(&psock->strp); |
ab7ac4eb TH |
273 | list_add_tail(&psock->psock_ready_list, |
274 | &mux->psocks_ready); | |
275 | spin_unlock_bh(&mux->rx_lock); | |
276 | return NULL; | |
277 | } | |
278 | ||
279 | kcm = list_first_entry(&mux->kcm_rx_waiters, | |
280 | struct kcm_sock, wait_rx_list); | |
281 | list_del(&kcm->wait_rx_list); | |
282 | kcm->rx_wait = false; | |
283 | ||
284 | psock->rx_kcm = kcm; | |
285 | kcm->rx_psock = psock; | |
286 | ||
287 | spin_unlock_bh(&mux->rx_lock); | |
288 | ||
289 | return kcm; | |
290 | } | |
291 | ||
292 | static void kcm_done(struct kcm_sock *kcm); | |
293 | ||
294 | static void kcm_done_work(struct work_struct *w) | |
295 | { | |
296 | kcm_done(container_of(w, struct kcm_sock, done_work)); | |
297 | } | |
298 | ||
299 | /* Lower sock held */ | |
300 | static void unreserve_rx_kcm(struct kcm_psock *psock, | |
301 | bool rcv_ready) | |
302 | { | |
303 | struct kcm_sock *kcm = psock->rx_kcm; | |
304 | struct kcm_mux *mux = psock->mux; | |
305 | ||
306 | if (!kcm) | |
307 | return; | |
308 | ||
309 | spin_lock_bh(&mux->rx_lock); | |
310 | ||
311 | psock->rx_kcm = NULL; | |
312 | kcm->rx_psock = NULL; | |
313 | ||
314 | /* Commit kcm->rx_psock before sk_rmem_alloc_get to sync with | |
315 | * kcm_rfree | |
316 | */ | |
317 | smp_mb(); | |
318 | ||
319 | if (unlikely(kcm->done)) { | |
320 | spin_unlock_bh(&mux->rx_lock); | |
321 | ||
322 | /* Need to run kcm_done in a task since we need to qcquire | |
323 | * callback locks which may already be held here. | |
324 | */ | |
325 | INIT_WORK(&kcm->done_work, kcm_done_work); | |
326 | schedule_work(&kcm->done_work); | |
327 | return; | |
328 | } | |
329 | ||
330 | if (unlikely(kcm->rx_disabled)) { | |
331 | requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue); | |
332 | } else if (rcv_ready || unlikely(!sk_rmem_alloc_get(&kcm->sk))) { | |
333 | /* Check for degenerative race with rx_wait that all | |
334 | * data was dequeued (accounted for in kcm_rfree). | |
335 | */ | |
336 | kcm_rcv_ready(kcm); | |
337 | } | |
338 | spin_unlock_bh(&mux->rx_lock); | |
339 | } | |
340 | ||
ab7ac4eb | 341 | /* Lower sock lock held */ |
96a59083 | 342 | static void psock_data_ready(struct sock *sk) |
ab7ac4eb TH |
343 | { |
344 | struct kcm_psock *psock; | |
345 | ||
346 | read_lock_bh(&sk->sk_callback_lock); | |
347 | ||
348 | psock = (struct kcm_psock *)sk->sk_user_data; | |
9b73896a | 349 | if (likely(psock)) |
96a59083 | 350 | strp_data_ready(&psock->strp); |
ab7ac4eb | 351 | |
ab7ac4eb TH |
352 | read_unlock_bh(&sk->sk_callback_lock); |
353 | } | |
354 | ||
9b73896a TH |
355 | /* Called with lower sock held */ |
356 | static void kcm_rcv_strparser(struct strparser *strp, struct sk_buff *skb) | |
ab7ac4eb | 357 | { |
9b73896a TH |
358 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
359 | struct kcm_sock *kcm; | |
ab7ac4eb | 360 | |
9b73896a TH |
361 | try_queue: |
362 | kcm = reserve_rx_kcm(psock, skb); | |
363 | if (!kcm) { | |
364 | /* Unable to reserve a KCM, message is held in psock and strp | |
365 | * is paused. | |
366 | */ | |
367 | return; | |
368 | } | |
ab7ac4eb | 369 | |
9b73896a TH |
370 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { |
371 | /* Should mean socket buffer full */ | |
372 | unreserve_rx_kcm(psock, false); | |
373 | goto try_queue; | |
374 | } | |
ab7ac4eb TH |
375 | } |
376 | ||
9b73896a | 377 | static int kcm_parse_func_strparser(struct strparser *strp, struct sk_buff *skb) |
ab7ac4eb | 378 | { |
9b73896a TH |
379 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
380 | struct bpf_prog *prog = psock->bpf_prog; | |
0355d6c1 | 381 | int res; |
9b73896a | 382 | |
0355d6c1 ED |
383 | preempt_disable(); |
384 | res = BPF_PROG_RUN(prog, skb); | |
385 | preempt_enable(); | |
386 | return res; | |
ab7ac4eb TH |
387 | } |
388 | ||
9b73896a | 389 | static int kcm_read_sock_done(struct strparser *strp, int err) |
ab7ac4eb | 390 | { |
9b73896a TH |
391 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
392 | ||
393 | unreserve_rx_kcm(psock, true); | |
394 | ||
395 | return err; | |
ab7ac4eb TH |
396 | } |
397 | ||
96a59083 | 398 | static void psock_state_change(struct sock *sk) |
ab7ac4eb | 399 | { |
a9a08845 LT |
400 | /* TCP only does a EPOLLIN for a half close. Do a EPOLLHUP here |
401 | * since application will normally not poll with EPOLLIN | |
ab7ac4eb TH |
402 | * on the TCP sockets. |
403 | */ | |
404 | ||
405 | report_csk_error(sk, EPIPE); | |
406 | } | |
407 | ||
96a59083 | 408 | static void psock_write_space(struct sock *sk) |
ab7ac4eb TH |
409 | { |
410 | struct kcm_psock *psock; | |
411 | struct kcm_mux *mux; | |
412 | struct kcm_sock *kcm; | |
413 | ||
414 | read_lock_bh(&sk->sk_callback_lock); | |
415 | ||
416 | psock = (struct kcm_psock *)sk->sk_user_data; | |
417 | if (unlikely(!psock)) | |
418 | goto out; | |
ab7ac4eb TH |
419 | mux = psock->mux; |
420 | ||
421 | spin_lock_bh(&mux->lock); | |
422 | ||
423 | /* Check if the socket is reserved so someone is waiting for sending. */ | |
424 | kcm = psock->tx_kcm; | |
9b73896a | 425 | if (kcm && !unlikely(kcm->tx_stopped)) |
ab7ac4eb TH |
426 | queue_work(kcm_wq, &kcm->tx_work); |
427 | ||
428 | spin_unlock_bh(&mux->lock); | |
429 | out: | |
430 | read_unlock_bh(&sk->sk_callback_lock); | |
431 | } | |
432 | ||
433 | static void unreserve_psock(struct kcm_sock *kcm); | |
434 | ||
435 | /* kcm sock is locked. */ | |
436 | static struct kcm_psock *reserve_psock(struct kcm_sock *kcm) | |
437 | { | |
438 | struct kcm_mux *mux = kcm->mux; | |
439 | struct kcm_psock *psock; | |
440 | ||
441 | psock = kcm->tx_psock; | |
442 | ||
443 | smp_rmb(); /* Must read tx_psock before tx_wait */ | |
444 | ||
445 | if (psock) { | |
446 | WARN_ON(kcm->tx_wait); | |
447 | if (unlikely(psock->tx_stopped)) | |
448 | unreserve_psock(kcm); | |
449 | else | |
450 | return kcm->tx_psock; | |
451 | } | |
452 | ||
453 | spin_lock_bh(&mux->lock); | |
454 | ||
455 | /* Check again under lock to see if psock was reserved for this | |
456 | * psock via psock_unreserve. | |
457 | */ | |
458 | psock = kcm->tx_psock; | |
459 | if (unlikely(psock)) { | |
460 | WARN_ON(kcm->tx_wait); | |
461 | spin_unlock_bh(&mux->lock); | |
462 | return kcm->tx_psock; | |
463 | } | |
464 | ||
465 | if (!list_empty(&mux->psocks_avail)) { | |
466 | psock = list_first_entry(&mux->psocks_avail, | |
467 | struct kcm_psock, | |
468 | psock_avail_list); | |
469 | list_del(&psock->psock_avail_list); | |
470 | if (kcm->tx_wait) { | |
471 | list_del(&kcm->wait_psock_list); | |
472 | kcm->tx_wait = false; | |
473 | } | |
474 | kcm->tx_psock = psock; | |
475 | psock->tx_kcm = kcm; | |
cd6e111b | 476 | KCM_STATS_INCR(psock->stats.reserved); |
ab7ac4eb TH |
477 | } else if (!kcm->tx_wait) { |
478 | list_add_tail(&kcm->wait_psock_list, | |
479 | &mux->kcm_tx_waiters); | |
480 | kcm->tx_wait = true; | |
481 | } | |
482 | ||
483 | spin_unlock_bh(&mux->lock); | |
484 | ||
485 | return psock; | |
486 | } | |
487 | ||
488 | /* mux lock held */ | |
489 | static void psock_now_avail(struct kcm_psock *psock) | |
490 | { | |
491 | struct kcm_mux *mux = psock->mux; | |
492 | struct kcm_sock *kcm; | |
493 | ||
494 | if (list_empty(&mux->kcm_tx_waiters)) { | |
495 | list_add_tail(&psock->psock_avail_list, | |
496 | &mux->psocks_avail); | |
497 | } else { | |
498 | kcm = list_first_entry(&mux->kcm_tx_waiters, | |
499 | struct kcm_sock, | |
500 | wait_psock_list); | |
501 | list_del(&kcm->wait_psock_list); | |
502 | kcm->tx_wait = false; | |
503 | psock->tx_kcm = kcm; | |
504 | ||
505 | /* Commit before changing tx_psock since that is read in | |
506 | * reserve_psock before queuing work. | |
507 | */ | |
508 | smp_mb(); | |
509 | ||
510 | kcm->tx_psock = psock; | |
cd6e111b | 511 | KCM_STATS_INCR(psock->stats.reserved); |
ab7ac4eb TH |
512 | queue_work(kcm_wq, &kcm->tx_work); |
513 | } | |
514 | } | |
515 | ||
516 | /* kcm sock is locked. */ | |
517 | static void unreserve_psock(struct kcm_sock *kcm) | |
518 | { | |
519 | struct kcm_psock *psock; | |
520 | struct kcm_mux *mux = kcm->mux; | |
521 | ||
522 | spin_lock_bh(&mux->lock); | |
523 | ||
524 | psock = kcm->tx_psock; | |
525 | ||
526 | if (WARN_ON(!psock)) { | |
527 | spin_unlock_bh(&mux->lock); | |
528 | return; | |
529 | } | |
530 | ||
531 | smp_rmb(); /* Read tx_psock before tx_wait */ | |
532 | ||
cd6e111b TH |
533 | kcm_update_tx_mux_stats(mux, psock); |
534 | ||
ab7ac4eb TH |
535 | WARN_ON(kcm->tx_wait); |
536 | ||
537 | kcm->tx_psock = NULL; | |
538 | psock->tx_kcm = NULL; | |
cd6e111b | 539 | KCM_STATS_INCR(psock->stats.unreserved); |
ab7ac4eb TH |
540 | |
541 | if (unlikely(psock->tx_stopped)) { | |
542 | if (psock->done) { | |
543 | /* Deferred free */ | |
544 | list_del(&psock->psock_list); | |
545 | mux->psocks_cnt--; | |
546 | sock_put(psock->sk); | |
547 | fput(psock->sk->sk_socket->file); | |
548 | kmem_cache_free(kcm_psockp, psock); | |
549 | } | |
550 | ||
551 | /* Don't put back on available list */ | |
552 | ||
553 | spin_unlock_bh(&mux->lock); | |
554 | ||
555 | return; | |
556 | } | |
557 | ||
558 | psock_now_avail(psock); | |
559 | ||
560 | spin_unlock_bh(&mux->lock); | |
561 | } | |
562 | ||
cd6e111b TH |
563 | static void kcm_report_tx_retry(struct kcm_sock *kcm) |
564 | { | |
565 | struct kcm_mux *mux = kcm->mux; | |
566 | ||
567 | spin_lock_bh(&mux->lock); | |
568 | KCM_STATS_INCR(mux->stats.tx_retries); | |
569 | spin_unlock_bh(&mux->lock); | |
570 | } | |
571 | ||
ab7ac4eb TH |
572 | /* Write any messages ready on the kcm socket. Called with kcm sock lock |
573 | * held. Return bytes actually sent or error. | |
574 | */ | |
575 | static int kcm_write_msgs(struct kcm_sock *kcm) | |
576 | { | |
577 | struct sock *sk = &kcm->sk; | |
578 | struct kcm_psock *psock; | |
579 | struct sk_buff *skb, *head; | |
580 | struct kcm_tx_msg *txm; | |
581 | unsigned short fragidx, frag_offset; | |
582 | unsigned int sent, total_sent = 0; | |
583 | int ret = 0; | |
584 | ||
585 | kcm->tx_wait_more = false; | |
586 | psock = kcm->tx_psock; | |
587 | if (unlikely(psock && psock->tx_stopped)) { | |
588 | /* A reserved psock was aborted asynchronously. Unreserve | |
589 | * it and we'll retry the message. | |
590 | */ | |
591 | unreserve_psock(kcm); | |
cd6e111b | 592 | kcm_report_tx_retry(kcm); |
ab7ac4eb TH |
593 | if (skb_queue_empty(&sk->sk_write_queue)) |
594 | return 0; | |
595 | ||
596 | kcm_tx_msg(skb_peek(&sk->sk_write_queue))->sent = 0; | |
597 | ||
598 | } else if (skb_queue_empty(&sk->sk_write_queue)) { | |
599 | return 0; | |
600 | } | |
601 | ||
602 | head = skb_peek(&sk->sk_write_queue); | |
603 | txm = kcm_tx_msg(head); | |
604 | ||
605 | if (txm->sent) { | |
606 | /* Send of first skbuff in queue already in progress */ | |
607 | if (WARN_ON(!psock)) { | |
608 | ret = -EINVAL; | |
609 | goto out; | |
610 | } | |
611 | sent = txm->sent; | |
612 | frag_offset = txm->frag_offset; | |
613 | fragidx = txm->fragidx; | |
614 | skb = txm->frag_skb; | |
615 | ||
616 | goto do_frag; | |
617 | } | |
618 | ||
619 | try_again: | |
620 | psock = reserve_psock(kcm); | |
621 | if (!psock) | |
622 | goto out; | |
623 | ||
624 | do { | |
625 | skb = head; | |
626 | txm = kcm_tx_msg(head); | |
627 | sent = 0; | |
628 | ||
629 | do_frag_list: | |
630 | if (WARN_ON(!skb_shinfo(skb)->nr_frags)) { | |
631 | ret = -EINVAL; | |
632 | goto out; | |
633 | } | |
634 | ||
635 | for (fragidx = 0; fragidx < skb_shinfo(skb)->nr_frags; | |
636 | fragidx++) { | |
637 | skb_frag_t *frag; | |
638 | ||
639 | frag_offset = 0; | |
640 | do_frag: | |
641 | frag = &skb_shinfo(skb)->frags[fragidx]; | |
d8e18a51 | 642 | if (WARN_ON(!skb_frag_size(frag))) { |
ab7ac4eb TH |
643 | ret = -EINVAL; |
644 | goto out; | |
645 | } | |
646 | ||
647 | ret = kernel_sendpage(psock->sk->sk_socket, | |
d8e18a51 | 648 | skb_frag_page(frag), |
b54c9d5b | 649 | skb_frag_off(frag) + frag_offset, |
d8e18a51 | 650 | skb_frag_size(frag) - frag_offset, |
ab7ac4eb TH |
651 | MSG_DONTWAIT); |
652 | if (ret <= 0) { | |
653 | if (ret == -EAGAIN) { | |
654 | /* Save state to try again when there's | |
655 | * write space on the socket | |
656 | */ | |
657 | txm->sent = sent; | |
658 | txm->frag_offset = frag_offset; | |
659 | txm->fragidx = fragidx; | |
660 | txm->frag_skb = skb; | |
661 | ||
662 | ret = 0; | |
663 | goto out; | |
664 | } | |
665 | ||
666 | /* Hard failure in sending message, abort this | |
667 | * psock since it has lost framing | |
668 | * synchonization and retry sending the | |
669 | * message from the beginning. | |
670 | */ | |
671 | kcm_abort_tx_psock(psock, ret ? -ret : EPIPE, | |
672 | true); | |
673 | unreserve_psock(kcm); | |
674 | ||
675 | txm->sent = 0; | |
cd6e111b | 676 | kcm_report_tx_retry(kcm); |
ab7ac4eb TH |
677 | ret = 0; |
678 | ||
679 | goto try_again; | |
680 | } | |
681 | ||
682 | sent += ret; | |
683 | frag_offset += ret; | |
cd6e111b | 684 | KCM_STATS_ADD(psock->stats.tx_bytes, ret); |
d8e18a51 | 685 | if (frag_offset < skb_frag_size(frag)) { |
ab7ac4eb TH |
686 | /* Not finished with this frag */ |
687 | goto do_frag; | |
688 | } | |
689 | } | |
690 | ||
691 | if (skb == head) { | |
692 | if (skb_has_frag_list(skb)) { | |
693 | skb = skb_shinfo(skb)->frag_list; | |
694 | goto do_frag_list; | |
695 | } | |
696 | } else if (skb->next) { | |
697 | skb = skb->next; | |
698 | goto do_frag_list; | |
699 | } | |
700 | ||
701 | /* Successfully sent the whole packet, account for it. */ | |
702 | skb_dequeue(&sk->sk_write_queue); | |
703 | kfree_skb(head); | |
704 | sk->sk_wmem_queued -= sent; | |
705 | total_sent += sent; | |
cd6e111b | 706 | KCM_STATS_INCR(psock->stats.tx_msgs); |
ab7ac4eb TH |
707 | } while ((head = skb_peek(&sk->sk_write_queue))); |
708 | out: | |
709 | if (!head) { | |
710 | /* Done with all queued messages. */ | |
711 | WARN_ON(!skb_queue_empty(&sk->sk_write_queue)); | |
712 | unreserve_psock(kcm); | |
713 | } | |
714 | ||
715 | /* Check if write space is available */ | |
716 | sk->sk_write_space(sk); | |
717 | ||
718 | return total_sent ? : ret; | |
719 | } | |
720 | ||
721 | static void kcm_tx_work(struct work_struct *w) | |
722 | { | |
723 | struct kcm_sock *kcm = container_of(w, struct kcm_sock, tx_work); | |
724 | struct sock *sk = &kcm->sk; | |
725 | int err; | |
726 | ||
727 | lock_sock(sk); | |
728 | ||
729 | /* Primarily for SOCK_DGRAM sockets, also handle asynchronous tx | |
730 | * aborts | |
731 | */ | |
732 | err = kcm_write_msgs(kcm); | |
733 | if (err < 0) { | |
734 | /* Hard failure in write, report error on KCM socket */ | |
735 | pr_warn("KCM: Hard failure on kcm_write_msgs %d\n", err); | |
736 | report_csk_error(&kcm->sk, -err); | |
737 | goto out; | |
738 | } | |
739 | ||
740 | /* Primarily for SOCK_SEQPACKET sockets */ | |
741 | if (likely(sk->sk_socket) && | |
742 | test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { | |
743 | clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
744 | sk->sk_write_space(sk); | |
745 | } | |
746 | ||
747 | out: | |
748 | release_sock(sk); | |
749 | } | |
750 | ||
751 | static void kcm_push(struct kcm_sock *kcm) | |
752 | { | |
753 | if (kcm->tx_wait_more) | |
754 | kcm_write_msgs(kcm); | |
755 | } | |
756 | ||
f29698fc TH |
757 | static ssize_t kcm_sendpage(struct socket *sock, struct page *page, |
758 | int offset, size_t size, int flags) | |
759 | ||
760 | { | |
761 | struct sock *sk = sock->sk; | |
762 | struct kcm_sock *kcm = kcm_sk(sk); | |
763 | struct sk_buff *skb = NULL, *head = NULL; | |
764 | long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); | |
765 | bool eor; | |
766 | int err = 0; | |
767 | int i; | |
768 | ||
769 | if (flags & MSG_SENDPAGE_NOTLAST) | |
770 | flags |= MSG_MORE; | |
771 | ||
772 | /* No MSG_EOR from splice, only look at MSG_MORE */ | |
773 | eor = !(flags & MSG_MORE); | |
774 | ||
775 | lock_sock(sk); | |
776 | ||
777 | sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); | |
778 | ||
779 | err = -EPIPE; | |
780 | if (sk->sk_err) | |
781 | goto out_error; | |
782 | ||
783 | if (kcm->seq_skb) { | |
784 | /* Previously opened message */ | |
785 | head = kcm->seq_skb; | |
786 | skb = kcm_tx_msg(head)->last_skb; | |
787 | i = skb_shinfo(skb)->nr_frags; | |
788 | ||
789 | if (skb_can_coalesce(skb, i, page, offset)) { | |
790 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], size); | |
791 | skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; | |
792 | goto coalesced; | |
793 | } | |
794 | ||
795 | if (i >= MAX_SKB_FRAGS) { | |
796 | struct sk_buff *tskb; | |
797 | ||
798 | tskb = alloc_skb(0, sk->sk_allocation); | |
799 | while (!tskb) { | |
800 | kcm_push(kcm); | |
801 | err = sk_stream_wait_memory(sk, &timeo); | |
802 | if (err) | |
803 | goto out_error; | |
804 | } | |
805 | ||
806 | if (head == skb) | |
807 | skb_shinfo(head)->frag_list = tskb; | |
808 | else | |
809 | skb->next = tskb; | |
810 | ||
811 | skb = tskb; | |
812 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
813 | i = 0; | |
814 | } | |
815 | } else { | |
816 | /* Call the sk_stream functions to manage the sndbuf mem. */ | |
817 | if (!sk_stream_memory_free(sk)) { | |
818 | kcm_push(kcm); | |
819 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
820 | err = sk_stream_wait_memory(sk, &timeo); | |
821 | if (err) | |
822 | goto out_error; | |
823 | } | |
824 | ||
825 | head = alloc_skb(0, sk->sk_allocation); | |
826 | while (!head) { | |
827 | kcm_push(kcm); | |
828 | err = sk_stream_wait_memory(sk, &timeo); | |
829 | if (err) | |
830 | goto out_error; | |
831 | } | |
832 | ||
833 | skb = head; | |
834 | i = 0; | |
835 | } | |
836 | ||
837 | get_page(page); | |
838 | skb_fill_page_desc(skb, i, page, offset, size); | |
839 | skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG; | |
840 | ||
841 | coalesced: | |
842 | skb->len += size; | |
843 | skb->data_len += size; | |
844 | skb->truesize += size; | |
845 | sk->sk_wmem_queued += size; | |
846 | sk_mem_charge(sk, size); | |
847 | ||
848 | if (head != skb) { | |
849 | head->len += size; | |
850 | head->data_len += size; | |
851 | head->truesize += size; | |
852 | } | |
853 | ||
854 | if (eor) { | |
855 | bool not_busy = skb_queue_empty(&sk->sk_write_queue); | |
856 | ||
857 | /* Message complete, queue it on send buffer */ | |
858 | __skb_queue_tail(&sk->sk_write_queue, head); | |
859 | kcm->seq_skb = NULL; | |
860 | KCM_STATS_INCR(kcm->stats.tx_msgs); | |
861 | ||
862 | if (flags & MSG_BATCH) { | |
863 | kcm->tx_wait_more = true; | |
864 | } else if (kcm->tx_wait_more || not_busy) { | |
865 | err = kcm_write_msgs(kcm); | |
866 | if (err < 0) { | |
867 | /* We got a hard error in write_msgs but have | |
868 | * already queued this message. Report an error | |
869 | * in the socket, but don't affect return value | |
870 | * from sendmsg | |
871 | */ | |
872 | pr_warn("KCM: Hard failure on kcm_write_msgs\n"); | |
873 | report_csk_error(&kcm->sk, -err); | |
874 | } | |
875 | } | |
876 | } else { | |
877 | /* Message not complete, save state */ | |
878 | kcm->seq_skb = head; | |
879 | kcm_tx_msg(head)->last_skb = skb; | |
880 | } | |
881 | ||
882 | KCM_STATS_ADD(kcm->stats.tx_bytes, size); | |
883 | ||
884 | release_sock(sk); | |
885 | return size; | |
886 | ||
887 | out_error: | |
888 | kcm_push(kcm); | |
889 | ||
890 | err = sk_stream_error(sk, flags, err); | |
891 | ||
892 | /* make sure we wake any epoll edge trigger waiter */ | |
893 | if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) | |
894 | sk->sk_write_space(sk); | |
895 | ||
896 | release_sock(sk); | |
897 | return err; | |
898 | } | |
899 | ||
ab7ac4eb TH |
900 | static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) |
901 | { | |
902 | struct sock *sk = sock->sk; | |
903 | struct kcm_sock *kcm = kcm_sk(sk); | |
904 | struct sk_buff *skb = NULL, *head = NULL; | |
905 | size_t copy, copied = 0; | |
906 | long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
907 | int eor = (sock->type == SOCK_DGRAM) ? | |
908 | !(msg->msg_flags & MSG_MORE) : !!(msg->msg_flags & MSG_EOR); | |
909 | int err = -EPIPE; | |
910 | ||
911 | lock_sock(sk); | |
912 | ||
913 | /* Per tcp_sendmsg this should be in poll */ | |
914 | sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); | |
915 | ||
916 | if (sk->sk_err) | |
917 | goto out_error; | |
918 | ||
919 | if (kcm->seq_skb) { | |
920 | /* Previously opened message */ | |
921 | head = kcm->seq_skb; | |
922 | skb = kcm_tx_msg(head)->last_skb; | |
923 | goto start; | |
924 | } | |
925 | ||
926 | /* Call the sk_stream functions to manage the sndbuf mem. */ | |
927 | if (!sk_stream_memory_free(sk)) { | |
928 | kcm_push(kcm); | |
929 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
930 | err = sk_stream_wait_memory(sk, &timeo); | |
931 | if (err) | |
932 | goto out_error; | |
933 | } | |
934 | ||
98e3862c WC |
935 | if (msg_data_left(msg)) { |
936 | /* New message, alloc head skb */ | |
ab7ac4eb | 937 | head = alloc_skb(0, sk->sk_allocation); |
98e3862c WC |
938 | while (!head) { |
939 | kcm_push(kcm); | |
940 | err = sk_stream_wait_memory(sk, &timeo); | |
941 | if (err) | |
942 | goto out_error; | |
ab7ac4eb | 943 | |
98e3862c WC |
944 | head = alloc_skb(0, sk->sk_allocation); |
945 | } | |
ab7ac4eb | 946 | |
98e3862c WC |
947 | skb = head; |
948 | ||
949 | /* Set ip_summed to CHECKSUM_UNNECESSARY to avoid calling | |
950 | * csum_and_copy_from_iter from skb_do_copy_data_nocache. | |
951 | */ | |
952 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
953 | } | |
ab7ac4eb TH |
954 | |
955 | start: | |
956 | while (msg_data_left(msg)) { | |
957 | bool merge = true; | |
958 | int i = skb_shinfo(skb)->nr_frags; | |
959 | struct page_frag *pfrag = sk_page_frag(sk); | |
960 | ||
961 | if (!sk_page_frag_refill(sk, pfrag)) | |
962 | goto wait_for_memory; | |
963 | ||
964 | if (!skb_can_coalesce(skb, i, pfrag->page, | |
965 | pfrag->offset)) { | |
966 | if (i == MAX_SKB_FRAGS) { | |
967 | struct sk_buff *tskb; | |
968 | ||
969 | tskb = alloc_skb(0, sk->sk_allocation); | |
970 | if (!tskb) | |
971 | goto wait_for_memory; | |
972 | ||
973 | if (head == skb) | |
974 | skb_shinfo(head)->frag_list = tskb; | |
975 | else | |
976 | skb->next = tskb; | |
977 | ||
978 | skb = tskb; | |
979 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
980 | continue; | |
981 | } | |
982 | merge = false; | |
983 | } | |
984 | ||
985 | copy = min_t(int, msg_data_left(msg), | |
986 | pfrag->size - pfrag->offset); | |
987 | ||
988 | if (!sk_wmem_schedule(sk, copy)) | |
989 | goto wait_for_memory; | |
990 | ||
991 | err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb, | |
992 | pfrag->page, | |
993 | pfrag->offset, | |
994 | copy); | |
995 | if (err) | |
996 | goto out_error; | |
997 | ||
998 | /* Update the skb. */ | |
999 | if (merge) { | |
1000 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); | |
1001 | } else { | |
1002 | skb_fill_page_desc(skb, i, pfrag->page, | |
1003 | pfrag->offset, copy); | |
1004 | get_page(pfrag->page); | |
1005 | } | |
1006 | ||
1007 | pfrag->offset += copy; | |
1008 | copied += copy; | |
1009 | if (head != skb) { | |
1010 | head->len += copy; | |
1011 | head->data_len += copy; | |
1012 | } | |
1013 | ||
1014 | continue; | |
1015 | ||
1016 | wait_for_memory: | |
1017 | kcm_push(kcm); | |
1018 | err = sk_stream_wait_memory(sk, &timeo); | |
1019 | if (err) | |
1020 | goto out_error; | |
1021 | } | |
1022 | ||
1023 | if (eor) { | |
1024 | bool not_busy = skb_queue_empty(&sk->sk_write_queue); | |
1025 | ||
98e3862c WC |
1026 | if (head) { |
1027 | /* Message complete, queue it on send buffer */ | |
1028 | __skb_queue_tail(&sk->sk_write_queue, head); | |
1029 | kcm->seq_skb = NULL; | |
1030 | KCM_STATS_INCR(kcm->stats.tx_msgs); | |
1031 | } | |
ab7ac4eb TH |
1032 | |
1033 | if (msg->msg_flags & MSG_BATCH) { | |
1034 | kcm->tx_wait_more = true; | |
1035 | } else if (kcm->tx_wait_more || not_busy) { | |
1036 | err = kcm_write_msgs(kcm); | |
1037 | if (err < 0) { | |
1038 | /* We got a hard error in write_msgs but have | |
1039 | * already queued this message. Report an error | |
1040 | * in the socket, but don't affect return value | |
1041 | * from sendmsg | |
1042 | */ | |
1043 | pr_warn("KCM: Hard failure on kcm_write_msgs\n"); | |
1044 | report_csk_error(&kcm->sk, -err); | |
1045 | } | |
1046 | } | |
1047 | } else { | |
1048 | /* Message not complete, save state */ | |
1049 | partial_message: | |
cd27b96b WC |
1050 | if (head) { |
1051 | kcm->seq_skb = head; | |
1052 | kcm_tx_msg(head)->last_skb = skb; | |
1053 | } | |
ab7ac4eb TH |
1054 | } |
1055 | ||
cd6e111b TH |
1056 | KCM_STATS_ADD(kcm->stats.tx_bytes, copied); |
1057 | ||
ab7ac4eb TH |
1058 | release_sock(sk); |
1059 | return copied; | |
1060 | ||
1061 | out_error: | |
1062 | kcm_push(kcm); | |
1063 | ||
1064 | if (copied && sock->type == SOCK_SEQPACKET) { | |
1065 | /* Wrote some bytes before encountering an | |
1066 | * error, return partial success. | |
1067 | */ | |
1068 | goto partial_message; | |
1069 | } | |
1070 | ||
1071 | if (head != kcm->seq_skb) | |
1072 | kfree_skb(head); | |
1073 | ||
1074 | err = sk_stream_error(sk, msg->msg_flags, err); | |
1075 | ||
1076 | /* make sure we wake any epoll edge trigger waiter */ | |
1077 | if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) | |
1078 | sk->sk_write_space(sk); | |
1079 | ||
1080 | release_sock(sk); | |
1081 | return err; | |
1082 | } | |
1083 | ||
1084 | static struct sk_buff *kcm_wait_data(struct sock *sk, int flags, | |
1085 | long timeo, int *err) | |
1086 | { | |
1087 | struct sk_buff *skb; | |
1088 | ||
1089 | while (!(skb = skb_peek(&sk->sk_receive_queue))) { | |
1090 | if (sk->sk_err) { | |
1091 | *err = sock_error(sk); | |
1092 | return NULL; | |
1093 | } | |
1094 | ||
1095 | if (sock_flag(sk, SOCK_DONE)) | |
1096 | return NULL; | |
1097 | ||
1098 | if ((flags & MSG_DONTWAIT) || !timeo) { | |
1099 | *err = -EAGAIN; | |
1100 | return NULL; | |
1101 | } | |
1102 | ||
1103 | sk_wait_data(sk, &timeo, NULL); | |
1104 | ||
1105 | /* Handle signals */ | |
1106 | if (signal_pending(current)) { | |
1107 | *err = sock_intr_errno(timeo); | |
1108 | return NULL; | |
1109 | } | |
1110 | } | |
1111 | ||
1112 | return skb; | |
1113 | } | |
1114 | ||
1115 | static int kcm_recvmsg(struct socket *sock, struct msghdr *msg, | |
1116 | size_t len, int flags) | |
1117 | { | |
1118 | struct sock *sk = sock->sk; | |
cd6e111b | 1119 | struct kcm_sock *kcm = kcm_sk(sk); |
ab7ac4eb TH |
1120 | int err = 0; |
1121 | long timeo; | |
bbb03029 | 1122 | struct strp_msg *stm; |
ab7ac4eb TH |
1123 | int copied = 0; |
1124 | struct sk_buff *skb; | |
1125 | ||
1126 | timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); | |
1127 | ||
1128 | lock_sock(sk); | |
1129 | ||
1130 | skb = kcm_wait_data(sk, flags, timeo, &err); | |
1131 | if (!skb) | |
1132 | goto out; | |
1133 | ||
1134 | /* Okay, have a message on the receive queue */ | |
1135 | ||
bbb03029 | 1136 | stm = strp_msg(skb); |
ab7ac4eb | 1137 | |
bbb03029 TH |
1138 | if (len > stm->full_len) |
1139 | len = stm->full_len; | |
ab7ac4eb | 1140 | |
bbb03029 | 1141 | err = skb_copy_datagram_msg(skb, stm->offset, msg, len); |
ab7ac4eb TH |
1142 | if (err < 0) |
1143 | goto out; | |
1144 | ||
1145 | copied = len; | |
1146 | if (likely(!(flags & MSG_PEEK))) { | |
cd6e111b | 1147 | KCM_STATS_ADD(kcm->stats.rx_bytes, copied); |
bbb03029 | 1148 | if (copied < stm->full_len) { |
ab7ac4eb TH |
1149 | if (sock->type == SOCK_DGRAM) { |
1150 | /* Truncated message */ | |
1151 | msg->msg_flags |= MSG_TRUNC; | |
1152 | goto msg_finished; | |
1153 | } | |
bbb03029 TH |
1154 | stm->offset += copied; |
1155 | stm->full_len -= copied; | |
ab7ac4eb TH |
1156 | } else { |
1157 | msg_finished: | |
1158 | /* Finished with message */ | |
1159 | msg->msg_flags |= MSG_EOR; | |
cd6e111b | 1160 | KCM_STATS_INCR(kcm->stats.rx_msgs); |
ab7ac4eb TH |
1161 | skb_unlink(skb, &sk->sk_receive_queue); |
1162 | kfree_skb(skb); | |
1163 | } | |
1164 | } | |
1165 | ||
1166 | out: | |
1167 | release_sock(sk); | |
1168 | ||
1169 | return copied ? : err; | |
1170 | } | |
1171 | ||
91687355 TH |
1172 | static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos, |
1173 | struct pipe_inode_info *pipe, size_t len, | |
1174 | unsigned int flags) | |
1175 | { | |
1176 | struct sock *sk = sock->sk; | |
1177 | struct kcm_sock *kcm = kcm_sk(sk); | |
1178 | long timeo; | |
bbb03029 | 1179 | struct strp_msg *stm; |
91687355 | 1180 | int err = 0; |
f1971a2e | 1181 | ssize_t copied; |
91687355 TH |
1182 | struct sk_buff *skb; |
1183 | ||
1184 | /* Only support splice for SOCKSEQPACKET */ | |
1185 | ||
1186 | timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); | |
1187 | ||
1188 | lock_sock(sk); | |
1189 | ||
1190 | skb = kcm_wait_data(sk, flags, timeo, &err); | |
1191 | if (!skb) | |
1192 | goto err_out; | |
1193 | ||
1194 | /* Okay, have a message on the receive queue */ | |
1195 | ||
bbb03029 | 1196 | stm = strp_msg(skb); |
91687355 | 1197 | |
bbb03029 TH |
1198 | if (len > stm->full_len) |
1199 | len = stm->full_len; | |
91687355 | 1200 | |
bbb03029 | 1201 | copied = skb_splice_bits(skb, sk, stm->offset, pipe, len, flags); |
91687355 TH |
1202 | if (copied < 0) { |
1203 | err = copied; | |
1204 | goto err_out; | |
1205 | } | |
1206 | ||
1207 | KCM_STATS_ADD(kcm->stats.rx_bytes, copied); | |
1208 | ||
bbb03029 TH |
1209 | stm->offset += copied; |
1210 | stm->full_len -= copied; | |
91687355 TH |
1211 | |
1212 | /* We have no way to return MSG_EOR. If all the bytes have been | |
1213 | * read we still leave the message in the receive socket buffer. | |
1214 | * A subsequent recvmsg needs to be done to return MSG_EOR and | |
1215 | * finish reading the message. | |
1216 | */ | |
1217 | ||
1218 | release_sock(sk); | |
1219 | ||
1220 | return copied; | |
1221 | ||
1222 | err_out: | |
1223 | release_sock(sk); | |
1224 | ||
1225 | return err; | |
1226 | } | |
1227 | ||
ab7ac4eb TH |
1228 | /* kcm sock lock held */ |
1229 | static void kcm_recv_disable(struct kcm_sock *kcm) | |
1230 | { | |
1231 | struct kcm_mux *mux = kcm->mux; | |
1232 | ||
1233 | if (kcm->rx_disabled) | |
1234 | return; | |
1235 | ||
1236 | spin_lock_bh(&mux->rx_lock); | |
1237 | ||
1238 | kcm->rx_disabled = 1; | |
1239 | ||
1240 | /* If a psock is reserved we'll do cleanup in unreserve */ | |
1241 | if (!kcm->rx_psock) { | |
1242 | if (kcm->rx_wait) { | |
1243 | list_del(&kcm->wait_rx_list); | |
1244 | kcm->rx_wait = false; | |
1245 | } | |
1246 | ||
1247 | requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue); | |
1248 | } | |
1249 | ||
1250 | spin_unlock_bh(&mux->rx_lock); | |
1251 | } | |
1252 | ||
1253 | /* kcm sock lock held */ | |
1254 | static void kcm_recv_enable(struct kcm_sock *kcm) | |
1255 | { | |
1256 | struct kcm_mux *mux = kcm->mux; | |
1257 | ||
1258 | if (!kcm->rx_disabled) | |
1259 | return; | |
1260 | ||
1261 | spin_lock_bh(&mux->rx_lock); | |
1262 | ||
1263 | kcm->rx_disabled = 0; | |
1264 | kcm_rcv_ready(kcm); | |
1265 | ||
1266 | spin_unlock_bh(&mux->rx_lock); | |
1267 | } | |
1268 | ||
1269 | static int kcm_setsockopt(struct socket *sock, int level, int optname, | |
1270 | char __user *optval, unsigned int optlen) | |
1271 | { | |
1272 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1273 | int val, valbool; | |
1274 | int err = 0; | |
1275 | ||
1276 | if (level != SOL_KCM) | |
1277 | return -ENOPROTOOPT; | |
1278 | ||
1279 | if (optlen < sizeof(int)) | |
1280 | return -EINVAL; | |
1281 | ||
1282 | if (get_user(val, (int __user *)optval)) | |
1283 | return -EINVAL; | |
1284 | ||
1285 | valbool = val ? 1 : 0; | |
1286 | ||
1287 | switch (optname) { | |
1288 | case KCM_RECV_DISABLE: | |
1289 | lock_sock(&kcm->sk); | |
1290 | if (valbool) | |
1291 | kcm_recv_disable(kcm); | |
1292 | else | |
1293 | kcm_recv_enable(kcm); | |
1294 | release_sock(&kcm->sk); | |
1295 | break; | |
1296 | default: | |
1297 | err = -ENOPROTOOPT; | |
1298 | } | |
1299 | ||
1300 | return err; | |
1301 | } | |
1302 | ||
1303 | static int kcm_getsockopt(struct socket *sock, int level, int optname, | |
1304 | char __user *optval, int __user *optlen) | |
1305 | { | |
1306 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1307 | int val, len; | |
1308 | ||
1309 | if (level != SOL_KCM) | |
1310 | return -ENOPROTOOPT; | |
1311 | ||
1312 | if (get_user(len, optlen)) | |
1313 | return -EFAULT; | |
1314 | ||
1315 | len = min_t(unsigned int, len, sizeof(int)); | |
1316 | if (len < 0) | |
1317 | return -EINVAL; | |
1318 | ||
1319 | switch (optname) { | |
1320 | case KCM_RECV_DISABLE: | |
1321 | val = kcm->rx_disabled; | |
1322 | break; | |
1323 | default: | |
1324 | return -ENOPROTOOPT; | |
1325 | } | |
1326 | ||
1327 | if (put_user(len, optlen)) | |
1328 | return -EFAULT; | |
1329 | if (copy_to_user(optval, &val, len)) | |
1330 | return -EFAULT; | |
1331 | return 0; | |
1332 | } | |
1333 | ||
1334 | static void init_kcm_sock(struct kcm_sock *kcm, struct kcm_mux *mux) | |
1335 | { | |
1336 | struct kcm_sock *tkcm; | |
1337 | struct list_head *head; | |
1338 | int index = 0; | |
1339 | ||
a11e1d43 LT |
1340 | /* For SOCK_SEQPACKET sock type, datagram_poll checks the sk_state, so |
1341 | * we set sk_state, otherwise epoll_wait always returns right away with | |
1342 | * EPOLLHUP | |
ab7ac4eb TH |
1343 | */ |
1344 | kcm->sk.sk_state = TCP_ESTABLISHED; | |
1345 | ||
1346 | /* Add to mux's kcm sockets list */ | |
1347 | kcm->mux = mux; | |
1348 | spin_lock_bh(&mux->lock); | |
1349 | ||
1350 | head = &mux->kcm_socks; | |
1351 | list_for_each_entry(tkcm, &mux->kcm_socks, kcm_sock_list) { | |
1352 | if (tkcm->index != index) | |
1353 | break; | |
1354 | head = &tkcm->kcm_sock_list; | |
1355 | index++; | |
1356 | } | |
1357 | ||
1358 | list_add(&kcm->kcm_sock_list, head); | |
1359 | kcm->index = index; | |
1360 | ||
1361 | mux->kcm_socks_cnt++; | |
1362 | spin_unlock_bh(&mux->lock); | |
1363 | ||
1364 | INIT_WORK(&kcm->tx_work, kcm_tx_work); | |
1365 | ||
1366 | spin_lock_bh(&mux->rx_lock); | |
1367 | kcm_rcv_ready(kcm); | |
1368 | spin_unlock_bh(&mux->rx_lock); | |
1369 | } | |
1370 | ||
1371 | static int kcm_attach(struct socket *sock, struct socket *csock, | |
1372 | struct bpf_prog *prog) | |
1373 | { | |
1374 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1375 | struct kcm_mux *mux = kcm->mux; | |
1376 | struct sock *csk; | |
1377 | struct kcm_psock *psock = NULL, *tpsock; | |
1378 | struct list_head *head; | |
1379 | int index = 0; | |
3fd87127 EB |
1380 | static const struct strp_callbacks cb = { |
1381 | .rcv_msg = kcm_rcv_strparser, | |
1382 | .parse_msg = kcm_parse_func_strparser, | |
1383 | .read_sock_done = kcm_read_sock_done, | |
1384 | }; | |
2cc683e8 | 1385 | int err = 0; |
ab7ac4eb TH |
1386 | |
1387 | csk = csock->sk; | |
1388 | if (!csk) | |
1389 | return -EINVAL; | |
1390 | ||
2cc683e8 TH |
1391 | lock_sock(csk); |
1392 | ||
581e7226 TH |
1393 | /* Only allow TCP sockets to be attached for now */ |
1394 | if ((csk->sk_family != AF_INET && csk->sk_family != AF_INET6) || | |
2cc683e8 TH |
1395 | csk->sk_protocol != IPPROTO_TCP) { |
1396 | err = -EOPNOTSUPP; | |
1397 | goto out; | |
1398 | } | |
581e7226 TH |
1399 | |
1400 | /* Don't allow listeners or closed sockets */ | |
2cc683e8 TH |
1401 | if (csk->sk_state == TCP_LISTEN || csk->sk_state == TCP_CLOSE) { |
1402 | err = -EOPNOTSUPP; | |
1403 | goto out; | |
1404 | } | |
351050ec | 1405 | |
ab7ac4eb | 1406 | psock = kmem_cache_zalloc(kcm_psockp, GFP_KERNEL); |
2cc683e8 TH |
1407 | if (!psock) { |
1408 | err = -ENOMEM; | |
1409 | goto out; | |
1410 | } | |
ab7ac4eb TH |
1411 | |
1412 | psock->mux = mux; | |
1413 | psock->sk = csk; | |
1414 | psock->bpf_prog = prog; | |
29152a34 | 1415 | |
96a59083 TH |
1416 | err = strp_init(&psock->strp, csk, &cb); |
1417 | if (err) { | |
1418 | kmem_cache_free(kcm_psockp, psock); | |
2cc683e8 | 1419 | goto out; |
96a59083 | 1420 | } |
ab7ac4eb | 1421 | |
ab7ac4eb | 1422 | write_lock_bh(&csk->sk_callback_lock); |
e5571240 TH |
1423 | |
1424 | /* Check if sk_user_data is aready by KCM or someone else. | |
1425 | * Must be done under lock to prevent race conditions. | |
1426 | */ | |
1427 | if (csk->sk_user_data) { | |
1428 | write_unlock_bh(&csk->sk_callback_lock); | |
dff8baa2 | 1429 | strp_stop(&psock->strp); |
e5571240 TH |
1430 | strp_done(&psock->strp); |
1431 | kmem_cache_free(kcm_psockp, psock); | |
2cc683e8 TH |
1432 | err = -EALREADY; |
1433 | goto out; | |
e5571240 TH |
1434 | } |
1435 | ||
ab7ac4eb TH |
1436 | psock->save_data_ready = csk->sk_data_ready; |
1437 | psock->save_write_space = csk->sk_write_space; | |
1438 | psock->save_state_change = csk->sk_state_change; | |
1439 | csk->sk_user_data = psock; | |
96a59083 TH |
1440 | csk->sk_data_ready = psock_data_ready; |
1441 | csk->sk_write_space = psock_write_space; | |
1442 | csk->sk_state_change = psock_state_change; | |
e5571240 | 1443 | |
ab7ac4eb TH |
1444 | write_unlock_bh(&csk->sk_callback_lock); |
1445 | ||
e5571240 TH |
1446 | sock_hold(csk); |
1447 | ||
ab7ac4eb TH |
1448 | /* Finished initialization, now add the psock to the MUX. */ |
1449 | spin_lock_bh(&mux->lock); | |
1450 | head = &mux->psocks; | |
1451 | list_for_each_entry(tpsock, &mux->psocks, psock_list) { | |
1452 | if (tpsock->index != index) | |
1453 | break; | |
1454 | head = &tpsock->psock_list; | |
1455 | index++; | |
1456 | } | |
1457 | ||
1458 | list_add(&psock->psock_list, head); | |
1459 | psock->index = index; | |
1460 | ||
cd6e111b | 1461 | KCM_STATS_INCR(mux->stats.psock_attach); |
ab7ac4eb TH |
1462 | mux->psocks_cnt++; |
1463 | psock_now_avail(psock); | |
1464 | spin_unlock_bh(&mux->lock); | |
1465 | ||
1466 | /* Schedule RX work in case there are already bytes queued */ | |
9b73896a | 1467 | strp_check_rcv(&psock->strp); |
ab7ac4eb | 1468 | |
2cc683e8 TH |
1469 | out: |
1470 | release_sock(csk); | |
1471 | ||
1472 | return err; | |
ab7ac4eb TH |
1473 | } |
1474 | ||
1475 | static int kcm_attach_ioctl(struct socket *sock, struct kcm_attach *info) | |
1476 | { | |
1477 | struct socket *csock; | |
1478 | struct bpf_prog *prog; | |
1479 | int err; | |
1480 | ||
1481 | csock = sockfd_lookup(info->fd, &err); | |
1482 | if (!csock) | |
1483 | return -ENOENT; | |
1484 | ||
113214be | 1485 | prog = bpf_prog_get_type(info->bpf_fd, BPF_PROG_TYPE_SOCKET_FILTER); |
ab7ac4eb TH |
1486 | if (IS_ERR(prog)) { |
1487 | err = PTR_ERR(prog); | |
1488 | goto out; | |
1489 | } | |
1490 | ||
ab7ac4eb TH |
1491 | err = kcm_attach(sock, csock, prog); |
1492 | if (err) { | |
1493 | bpf_prog_put(prog); | |
1494 | goto out; | |
1495 | } | |
1496 | ||
1497 | /* Keep reference on file also */ | |
1498 | ||
1499 | return 0; | |
1500 | out: | |
1501 | fput(csock->file); | |
1502 | return err; | |
1503 | } | |
1504 | ||
1505 | static void kcm_unattach(struct kcm_psock *psock) | |
1506 | { | |
1507 | struct sock *csk = psock->sk; | |
1508 | struct kcm_mux *mux = psock->mux; | |
1509 | ||
1616b38f TH |
1510 | lock_sock(csk); |
1511 | ||
ab7ac4eb TH |
1512 | /* Stop getting callbacks from TCP socket. After this there should |
1513 | * be no way to reserve a kcm for this psock. | |
1514 | */ | |
1515 | write_lock_bh(&csk->sk_callback_lock); | |
1516 | csk->sk_user_data = NULL; | |
1517 | csk->sk_data_ready = psock->save_data_ready; | |
1518 | csk->sk_write_space = psock->save_write_space; | |
1519 | csk->sk_state_change = psock->save_state_change; | |
9b73896a | 1520 | strp_stop(&psock->strp); |
ab7ac4eb TH |
1521 | |
1522 | if (WARN_ON(psock->rx_kcm)) { | |
1523 | write_unlock_bh(&csk->sk_callback_lock); | |
2cc683e8 | 1524 | release_sock(csk); |
ab7ac4eb TH |
1525 | return; |
1526 | } | |
1527 | ||
1528 | spin_lock_bh(&mux->rx_lock); | |
1529 | ||
1530 | /* Stop receiver activities. After this point psock should not be | |
1531 | * able to get onto ready list either through callbacks or work. | |
1532 | */ | |
1533 | if (psock->ready_rx_msg) { | |
1534 | list_del(&psock->psock_ready_list); | |
1535 | kfree_skb(psock->ready_rx_msg); | |
1536 | psock->ready_rx_msg = NULL; | |
cd6e111b | 1537 | KCM_STATS_INCR(mux->stats.rx_ready_drops); |
ab7ac4eb TH |
1538 | } |
1539 | ||
1540 | spin_unlock_bh(&mux->rx_lock); | |
1541 | ||
1542 | write_unlock_bh(&csk->sk_callback_lock); | |
1543 | ||
1616b38f TH |
1544 | /* Call strp_done without sock lock */ |
1545 | release_sock(csk); | |
9b73896a | 1546 | strp_done(&psock->strp); |
1616b38f | 1547 | lock_sock(csk); |
ab7ac4eb TH |
1548 | |
1549 | bpf_prog_put(psock->bpf_prog); | |
1550 | ||
ab7ac4eb TH |
1551 | spin_lock_bh(&mux->lock); |
1552 | ||
cd6e111b | 1553 | aggregate_psock_stats(&psock->stats, &mux->aggregate_psock_stats); |
9b73896a | 1554 | save_strp_stats(&psock->strp, &mux->aggregate_strp_stats); |
cd6e111b TH |
1555 | |
1556 | KCM_STATS_INCR(mux->stats.psock_unattach); | |
1557 | ||
ab7ac4eb TH |
1558 | if (psock->tx_kcm) { |
1559 | /* psock was reserved. Just mark it finished and we will clean | |
1560 | * up in the kcm paths, we need kcm lock which can not be | |
1561 | * acquired here. | |
1562 | */ | |
cd6e111b | 1563 | KCM_STATS_INCR(mux->stats.psock_unattach_rsvd); |
ab7ac4eb TH |
1564 | spin_unlock_bh(&mux->lock); |
1565 | ||
1566 | /* We are unattaching a socket that is reserved. Abort the | |
1567 | * socket since we may be out of sync in sending on it. We need | |
1568 | * to do this without the mux lock. | |
1569 | */ | |
1570 | kcm_abort_tx_psock(psock, EPIPE, false); | |
1571 | ||
1572 | spin_lock_bh(&mux->lock); | |
1573 | if (!psock->tx_kcm) { | |
1574 | /* psock now unreserved in window mux was unlocked */ | |
1575 | goto no_reserved; | |
1576 | } | |
1577 | psock->done = 1; | |
1578 | ||
1579 | /* Commit done before queuing work to process it */ | |
1580 | smp_mb(); | |
1581 | ||
1582 | /* Queue tx work to make sure psock->done is handled */ | |
1583 | queue_work(kcm_wq, &psock->tx_kcm->tx_work); | |
1584 | spin_unlock_bh(&mux->lock); | |
1585 | } else { | |
1586 | no_reserved: | |
1587 | if (!psock->tx_stopped) | |
1588 | list_del(&psock->psock_avail_list); | |
1589 | list_del(&psock->psock_list); | |
1590 | mux->psocks_cnt--; | |
1591 | spin_unlock_bh(&mux->lock); | |
1592 | ||
1593 | sock_put(csk); | |
1594 | fput(csk->sk_socket->file); | |
1595 | kmem_cache_free(kcm_psockp, psock); | |
1596 | } | |
1616b38f TH |
1597 | |
1598 | release_sock(csk); | |
ab7ac4eb TH |
1599 | } |
1600 | ||
1601 | static int kcm_unattach_ioctl(struct socket *sock, struct kcm_unattach *info) | |
1602 | { | |
1603 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1604 | struct kcm_mux *mux = kcm->mux; | |
1605 | struct kcm_psock *psock; | |
1606 | struct socket *csock; | |
1607 | struct sock *csk; | |
1608 | int err; | |
1609 | ||
1610 | csock = sockfd_lookup(info->fd, &err); | |
1611 | if (!csock) | |
1612 | return -ENOENT; | |
1613 | ||
1614 | csk = csock->sk; | |
1615 | if (!csk) { | |
1616 | err = -EINVAL; | |
1617 | goto out; | |
1618 | } | |
1619 | ||
1620 | err = -ENOENT; | |
1621 | ||
1622 | spin_lock_bh(&mux->lock); | |
1623 | ||
1624 | list_for_each_entry(psock, &mux->psocks, psock_list) { | |
1625 | if (psock->sk != csk) | |
1626 | continue; | |
1627 | ||
1628 | /* Found the matching psock */ | |
1629 | ||
1630 | if (psock->unattaching || WARN_ON(psock->done)) { | |
1631 | err = -EALREADY; | |
1632 | break; | |
1633 | } | |
1634 | ||
1635 | psock->unattaching = 1; | |
1636 | ||
1637 | spin_unlock_bh(&mux->lock); | |
1638 | ||
9b73896a | 1639 | /* Lower socket lock should already be held */ |
ab7ac4eb TH |
1640 | kcm_unattach(psock); |
1641 | ||
1642 | err = 0; | |
1643 | goto out; | |
1644 | } | |
1645 | ||
1646 | spin_unlock_bh(&mux->lock); | |
1647 | ||
1648 | out: | |
1649 | fput(csock->file); | |
1650 | return err; | |
1651 | } | |
1652 | ||
1653 | static struct proto kcm_proto = { | |
1654 | .name = "KCM", | |
1655 | .owner = THIS_MODULE, | |
1656 | .obj_size = sizeof(struct kcm_sock), | |
1657 | }; | |
1658 | ||
1659 | /* Clone a kcm socket. */ | |
a5739435 | 1660 | static struct file *kcm_clone(struct socket *osock) |
ab7ac4eb TH |
1661 | { |
1662 | struct socket *newsock; | |
1663 | struct sock *newsk; | |
ab7ac4eb | 1664 | |
ab7ac4eb TH |
1665 | newsock = sock_alloc(); |
1666 | if (!newsock) | |
a5739435 | 1667 | return ERR_PTR(-ENFILE); |
ab7ac4eb TH |
1668 | |
1669 | newsock->type = osock->type; | |
1670 | newsock->ops = osock->ops; | |
1671 | ||
1672 | __module_get(newsock->ops->owner); | |
1673 | ||
ab7ac4eb | 1674 | newsk = sk_alloc(sock_net(osock->sk), PF_KCM, GFP_KERNEL, |
eb7f54b9 | 1675 | &kcm_proto, false); |
ab7ac4eb | 1676 | if (!newsk) { |
a5739435 AV |
1677 | sock_release(newsock); |
1678 | return ERR_PTR(-ENOMEM); | |
ab7ac4eb | 1679 | } |
ab7ac4eb TH |
1680 | sock_init_data(newsock, newsk); |
1681 | init_kcm_sock(kcm_sk(newsk), kcm_sk(osock->sk)->mux); | |
1682 | ||
8e1611e2 | 1683 | return sock_alloc_file(newsock, 0, osock->sk->sk_prot_creator->name); |
ab7ac4eb TH |
1684 | } |
1685 | ||
1686 | static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) | |
1687 | { | |
1688 | int err; | |
1689 | ||
1690 | switch (cmd) { | |
1691 | case SIOCKCMATTACH: { | |
1692 | struct kcm_attach info; | |
1693 | ||
1694 | if (copy_from_user(&info, (void __user *)arg, sizeof(info))) | |
a80db69e | 1695 | return -EFAULT; |
ab7ac4eb TH |
1696 | |
1697 | err = kcm_attach_ioctl(sock, &info); | |
1698 | ||
1699 | break; | |
1700 | } | |
1701 | case SIOCKCMUNATTACH: { | |
1702 | struct kcm_unattach info; | |
1703 | ||
1704 | if (copy_from_user(&info, (void __user *)arg, sizeof(info))) | |
a80db69e | 1705 | return -EFAULT; |
ab7ac4eb TH |
1706 | |
1707 | err = kcm_unattach_ioctl(sock, &info); | |
1708 | ||
1709 | break; | |
1710 | } | |
1711 | case SIOCKCMCLONE: { | |
1712 | struct kcm_clone info; | |
a5739435 AV |
1713 | struct file *file; |
1714 | ||
1715 | info.fd = get_unused_fd_flags(0); | |
1716 | if (unlikely(info.fd < 0)) | |
1717 | return info.fd; | |
ab7ac4eb | 1718 | |
a5739435 AV |
1719 | file = kcm_clone(sock); |
1720 | if (IS_ERR(file)) { | |
1721 | put_unused_fd(info.fd); | |
1722 | return PTR_ERR(file); | |
1723 | } | |
1724 | if (copy_to_user((void __user *)arg, &info, | |
1725 | sizeof(info))) { | |
1726 | put_unused_fd(info.fd); | |
1727 | fput(file); | |
1728 | return -EFAULT; | |
1729 | } | |
1730 | fd_install(info.fd, file); | |
1731 | err = 0; | |
ab7ac4eb TH |
1732 | break; |
1733 | } | |
1734 | default: | |
1735 | err = -ENOIOCTLCMD; | |
1736 | break; | |
1737 | } | |
1738 | ||
1739 | return err; | |
1740 | } | |
1741 | ||
1742 | static void free_mux(struct rcu_head *rcu) | |
1743 | { | |
1744 | struct kcm_mux *mux = container_of(rcu, | |
1745 | struct kcm_mux, rcu); | |
1746 | ||
1747 | kmem_cache_free(kcm_muxp, mux); | |
1748 | } | |
1749 | ||
1750 | static void release_mux(struct kcm_mux *mux) | |
1751 | { | |
1752 | struct kcm_net *knet = mux->knet; | |
1753 | struct kcm_psock *psock, *tmp_psock; | |
1754 | ||
1755 | /* Release psocks */ | |
1756 | list_for_each_entry_safe(psock, tmp_psock, | |
1757 | &mux->psocks, psock_list) { | |
1616b38f | 1758 | if (!WARN_ON(psock->unattaching)) |
ab7ac4eb TH |
1759 | kcm_unattach(psock); |
1760 | } | |
1761 | ||
1762 | if (WARN_ON(mux->psocks_cnt)) | |
1763 | return; | |
1764 | ||
1765 | __skb_queue_purge(&mux->rx_hold_queue); | |
1766 | ||
1767 | mutex_lock(&knet->mutex); | |
cd6e111b TH |
1768 | aggregate_mux_stats(&mux->stats, &knet->aggregate_mux_stats); |
1769 | aggregate_psock_stats(&mux->aggregate_psock_stats, | |
1770 | &knet->aggregate_psock_stats); | |
9b73896a TH |
1771 | aggregate_strp_stats(&mux->aggregate_strp_stats, |
1772 | &knet->aggregate_strp_stats); | |
ab7ac4eb TH |
1773 | list_del_rcu(&mux->kcm_mux_list); |
1774 | knet->count--; | |
1775 | mutex_unlock(&knet->mutex); | |
1776 | ||
1777 | call_rcu(&mux->rcu, free_mux); | |
1778 | } | |
1779 | ||
1780 | static void kcm_done(struct kcm_sock *kcm) | |
1781 | { | |
1782 | struct kcm_mux *mux = kcm->mux; | |
1783 | struct sock *sk = &kcm->sk; | |
1784 | int socks_cnt; | |
1785 | ||
1786 | spin_lock_bh(&mux->rx_lock); | |
1787 | if (kcm->rx_psock) { | |
1788 | /* Cleanup in unreserve_rx_kcm */ | |
1789 | WARN_ON(kcm->done); | |
1790 | kcm->rx_disabled = 1; | |
1791 | kcm->done = 1; | |
1792 | spin_unlock_bh(&mux->rx_lock); | |
1793 | return; | |
1794 | } | |
1795 | ||
1796 | if (kcm->rx_wait) { | |
1797 | list_del(&kcm->wait_rx_list); | |
1798 | kcm->rx_wait = false; | |
1799 | } | |
1800 | /* Move any pending receive messages to other kcm sockets */ | |
1801 | requeue_rx_msgs(mux, &sk->sk_receive_queue); | |
1802 | ||
1803 | spin_unlock_bh(&mux->rx_lock); | |
1804 | ||
1805 | if (WARN_ON(sk_rmem_alloc_get(sk))) | |
1806 | return; | |
1807 | ||
1808 | /* Detach from MUX */ | |
1809 | spin_lock_bh(&mux->lock); | |
1810 | ||
1811 | list_del(&kcm->kcm_sock_list); | |
1812 | mux->kcm_socks_cnt--; | |
1813 | socks_cnt = mux->kcm_socks_cnt; | |
1814 | ||
1815 | spin_unlock_bh(&mux->lock); | |
1816 | ||
1817 | if (!socks_cnt) { | |
1818 | /* We are done with the mux now. */ | |
1819 | release_mux(mux); | |
1820 | } | |
1821 | ||
1822 | WARN_ON(kcm->rx_wait); | |
1823 | ||
1824 | sock_put(&kcm->sk); | |
1825 | } | |
1826 | ||
1827 | /* Called by kcm_release to close a KCM socket. | |
1828 | * If this is the last KCM socket on the MUX, destroy the MUX. | |
1829 | */ | |
1830 | static int kcm_release(struct socket *sock) | |
1831 | { | |
1832 | struct sock *sk = sock->sk; | |
1833 | struct kcm_sock *kcm; | |
1834 | struct kcm_mux *mux; | |
1835 | struct kcm_psock *psock; | |
1836 | ||
1837 | if (!sk) | |
1838 | return 0; | |
1839 | ||
1840 | kcm = kcm_sk(sk); | |
1841 | mux = kcm->mux; | |
1842 | ||
1843 | sock_orphan(sk); | |
1844 | kfree_skb(kcm->seq_skb); | |
1845 | ||
1846 | lock_sock(sk); | |
1847 | /* Purge queue under lock to avoid race condition with tx_work trying | |
1848 | * to act when queue is nonempty. If tx_work runs after this point | |
1849 | * it will just return. | |
1850 | */ | |
1851 | __skb_queue_purge(&sk->sk_write_queue); | |
9b73896a TH |
1852 | |
1853 | /* Set tx_stopped. This is checked when psock is bound to a kcm and we | |
1854 | * get a writespace callback. This prevents further work being queued | |
1855 | * from the callback (unbinding the psock occurs after canceling work. | |
1856 | */ | |
1857 | kcm->tx_stopped = 1; | |
1858 | ||
ab7ac4eb TH |
1859 | release_sock(sk); |
1860 | ||
1861 | spin_lock_bh(&mux->lock); | |
1862 | if (kcm->tx_wait) { | |
1863 | /* Take of tx_wait list, after this point there should be no way | |
1864 | * that a psock will be assigned to this kcm. | |
1865 | */ | |
1866 | list_del(&kcm->wait_psock_list); | |
1867 | kcm->tx_wait = false; | |
1868 | } | |
1869 | spin_unlock_bh(&mux->lock); | |
1870 | ||
1871 | /* Cancel work. After this point there should be no outside references | |
1872 | * to the kcm socket. | |
1873 | */ | |
1874 | cancel_work_sync(&kcm->tx_work); | |
1875 | ||
1876 | lock_sock(sk); | |
1877 | psock = kcm->tx_psock; | |
1878 | if (psock) { | |
1879 | /* A psock was reserved, so we need to kill it since it | |
1880 | * may already have some bytes queued from a message. We | |
1881 | * need to do this after removing kcm from tx_wait list. | |
1882 | */ | |
1883 | kcm_abort_tx_psock(psock, EPIPE, false); | |
1884 | unreserve_psock(kcm); | |
1885 | } | |
1886 | release_sock(sk); | |
1887 | ||
1888 | WARN_ON(kcm->tx_wait); | |
1889 | WARN_ON(kcm->tx_psock); | |
1890 | ||
1891 | sock->sk = NULL; | |
1892 | ||
1893 | kcm_done(kcm); | |
1894 | ||
1895 | return 0; | |
1896 | } | |
1897 | ||
91687355 | 1898 | static const struct proto_ops kcm_dgram_ops = { |
ab7ac4eb TH |
1899 | .family = PF_KCM, |
1900 | .owner = THIS_MODULE, | |
1901 | .release = kcm_release, | |
1902 | .bind = sock_no_bind, | |
1903 | .connect = sock_no_connect, | |
1904 | .socketpair = sock_no_socketpair, | |
1905 | .accept = sock_no_accept, | |
1906 | .getname = sock_no_getname, | |
a11e1d43 | 1907 | .poll = datagram_poll, |
ab7ac4eb TH |
1908 | .ioctl = kcm_ioctl, |
1909 | .listen = sock_no_listen, | |
1910 | .shutdown = sock_no_shutdown, | |
1911 | .setsockopt = kcm_setsockopt, | |
1912 | .getsockopt = kcm_getsockopt, | |
1913 | .sendmsg = kcm_sendmsg, | |
1914 | .recvmsg = kcm_recvmsg, | |
1915 | .mmap = sock_no_mmap, | |
f29698fc | 1916 | .sendpage = kcm_sendpage, |
ab7ac4eb TH |
1917 | }; |
1918 | ||
91687355 TH |
1919 | static const struct proto_ops kcm_seqpacket_ops = { |
1920 | .family = PF_KCM, | |
1921 | .owner = THIS_MODULE, | |
1922 | .release = kcm_release, | |
1923 | .bind = sock_no_bind, | |
1924 | .connect = sock_no_connect, | |
1925 | .socketpair = sock_no_socketpair, | |
1926 | .accept = sock_no_accept, | |
1927 | .getname = sock_no_getname, | |
a11e1d43 | 1928 | .poll = datagram_poll, |
91687355 TH |
1929 | .ioctl = kcm_ioctl, |
1930 | .listen = sock_no_listen, | |
1931 | .shutdown = sock_no_shutdown, | |
1932 | .setsockopt = kcm_setsockopt, | |
1933 | .getsockopt = kcm_getsockopt, | |
1934 | .sendmsg = kcm_sendmsg, | |
1935 | .recvmsg = kcm_recvmsg, | |
1936 | .mmap = sock_no_mmap, | |
f29698fc | 1937 | .sendpage = kcm_sendpage, |
91687355 TH |
1938 | .splice_read = kcm_splice_read, |
1939 | }; | |
1940 | ||
ab7ac4eb TH |
1941 | /* Create proto operation for kcm sockets */ |
1942 | static int kcm_create(struct net *net, struct socket *sock, | |
1943 | int protocol, int kern) | |
1944 | { | |
1945 | struct kcm_net *knet = net_generic(net, kcm_net_id); | |
1946 | struct sock *sk; | |
1947 | struct kcm_mux *mux; | |
1948 | ||
1949 | switch (sock->type) { | |
1950 | case SOCK_DGRAM: | |
91687355 TH |
1951 | sock->ops = &kcm_dgram_ops; |
1952 | break; | |
ab7ac4eb | 1953 | case SOCK_SEQPACKET: |
91687355 | 1954 | sock->ops = &kcm_seqpacket_ops; |
ab7ac4eb TH |
1955 | break; |
1956 | default: | |
1957 | return -ESOCKTNOSUPPORT; | |
1958 | } | |
1959 | ||
1960 | if (protocol != KCMPROTO_CONNECTED) | |
1961 | return -EPROTONOSUPPORT; | |
1962 | ||
1963 | sk = sk_alloc(net, PF_KCM, GFP_KERNEL, &kcm_proto, kern); | |
1964 | if (!sk) | |
1965 | return -ENOMEM; | |
1966 | ||
1967 | /* Allocate a kcm mux, shared between KCM sockets */ | |
1968 | mux = kmem_cache_zalloc(kcm_muxp, GFP_KERNEL); | |
1969 | if (!mux) { | |
1970 | sk_free(sk); | |
1971 | return -ENOMEM; | |
1972 | } | |
1973 | ||
1974 | spin_lock_init(&mux->lock); | |
1975 | spin_lock_init(&mux->rx_lock); | |
1976 | INIT_LIST_HEAD(&mux->kcm_socks); | |
1977 | INIT_LIST_HEAD(&mux->kcm_rx_waiters); | |
1978 | INIT_LIST_HEAD(&mux->kcm_tx_waiters); | |
1979 | ||
1980 | INIT_LIST_HEAD(&mux->psocks); | |
1981 | INIT_LIST_HEAD(&mux->psocks_ready); | |
1982 | INIT_LIST_HEAD(&mux->psocks_avail); | |
1983 | ||
1984 | mux->knet = knet; | |
1985 | ||
1986 | /* Add new MUX to list */ | |
1987 | mutex_lock(&knet->mutex); | |
1988 | list_add_rcu(&mux->kcm_mux_list, &knet->mux_list); | |
1989 | knet->count++; | |
1990 | mutex_unlock(&knet->mutex); | |
1991 | ||
1992 | skb_queue_head_init(&mux->rx_hold_queue); | |
1993 | ||
1994 | /* Init KCM socket */ | |
1995 | sock_init_data(sock, sk); | |
1996 | init_kcm_sock(kcm_sk(sk), mux); | |
1997 | ||
1998 | return 0; | |
1999 | } | |
2000 | ||
173e7837 | 2001 | static const struct net_proto_family kcm_family_ops = { |
ab7ac4eb TH |
2002 | .family = PF_KCM, |
2003 | .create = kcm_create, | |
2004 | .owner = THIS_MODULE, | |
2005 | }; | |
2006 | ||
2007 | static __net_init int kcm_init_net(struct net *net) | |
2008 | { | |
2009 | struct kcm_net *knet = net_generic(net, kcm_net_id); | |
2010 | ||
2011 | INIT_LIST_HEAD_RCU(&knet->mux_list); | |
2012 | mutex_init(&knet->mutex); | |
2013 | ||
2014 | return 0; | |
2015 | } | |
2016 | ||
2017 | static __net_exit void kcm_exit_net(struct net *net) | |
2018 | { | |
2019 | struct kcm_net *knet = net_generic(net, kcm_net_id); | |
2020 | ||
2021 | /* All KCM sockets should be closed at this point, which should mean | |
2022 | * that all multiplexors and psocks have been destroyed. | |
2023 | */ | |
2024 | WARN_ON(!list_empty(&knet->mux_list)); | |
2025 | } | |
2026 | ||
2027 | static struct pernet_operations kcm_net_ops = { | |
2028 | .init = kcm_init_net, | |
2029 | .exit = kcm_exit_net, | |
2030 | .id = &kcm_net_id, | |
2031 | .size = sizeof(struct kcm_net), | |
2032 | }; | |
2033 | ||
2034 | static int __init kcm_init(void) | |
2035 | { | |
2036 | int err = -ENOMEM; | |
2037 | ||
2038 | kcm_muxp = kmem_cache_create("kcm_mux_cache", | |
2039 | sizeof(struct kcm_mux), 0, | |
c2115240 | 2040 | SLAB_HWCACHE_ALIGN, NULL); |
ab7ac4eb TH |
2041 | if (!kcm_muxp) |
2042 | goto fail; | |
2043 | ||
2044 | kcm_psockp = kmem_cache_create("kcm_psock_cache", | |
2045 | sizeof(struct kcm_psock), 0, | |
c2115240 | 2046 | SLAB_HWCACHE_ALIGN, NULL); |
ab7ac4eb TH |
2047 | if (!kcm_psockp) |
2048 | goto fail; | |
2049 | ||
2050 | kcm_wq = create_singlethread_workqueue("kkcmd"); | |
2051 | if (!kcm_wq) | |
2052 | goto fail; | |
2053 | ||
2054 | err = proto_register(&kcm_proto, 1); | |
2055 | if (err) | |
2056 | goto fail; | |
2057 | ||
ab7ac4eb TH |
2058 | err = register_pernet_device(&kcm_net_ops); |
2059 | if (err) | |
2060 | goto net_ops_fail; | |
2061 | ||
3c446e6f JS |
2062 | err = sock_register(&kcm_family_ops); |
2063 | if (err) | |
2064 | goto sock_register_fail; | |
2065 | ||
cd6e111b TH |
2066 | err = kcm_proc_init(); |
2067 | if (err) | |
2068 | goto proc_init_fail; | |
2069 | ||
ab7ac4eb TH |
2070 | return 0; |
2071 | ||
cd6e111b | 2072 | proc_init_fail: |
ab7ac4eb TH |
2073 | sock_unregister(PF_KCM); |
2074 | ||
2075 | sock_register_fail: | |
3c446e6f JS |
2076 | unregister_pernet_device(&kcm_net_ops); |
2077 | ||
2078 | net_ops_fail: | |
ab7ac4eb TH |
2079 | proto_unregister(&kcm_proto); |
2080 | ||
2081 | fail: | |
2082 | kmem_cache_destroy(kcm_muxp); | |
2083 | kmem_cache_destroy(kcm_psockp); | |
2084 | ||
2085 | if (kcm_wq) | |
2086 | destroy_workqueue(kcm_wq); | |
2087 | ||
2088 | return err; | |
2089 | } | |
2090 | ||
2091 | static void __exit kcm_exit(void) | |
2092 | { | |
cd6e111b | 2093 | kcm_proc_exit(); |
ab7ac4eb | 2094 | sock_unregister(PF_KCM); |
3c446e6f | 2095 | unregister_pernet_device(&kcm_net_ops); |
ab7ac4eb TH |
2096 | proto_unregister(&kcm_proto); |
2097 | destroy_workqueue(kcm_wq); | |
2098 | ||
2099 | kmem_cache_destroy(kcm_muxp); | |
2100 | kmem_cache_destroy(kcm_psockp); | |
2101 | } | |
2102 | ||
2103 | module_init(kcm_init); | |
2104 | module_exit(kcm_exit); | |
2105 | ||
2106 | MODULE_LICENSE("GPL"); | |
2107 | MODULE_ALIAS_NETPROTO(PF_KCM); |