Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
9b73896a TH |
2 | /* |
3 | * Kernel Connection Multiplexor | |
4 | * | |
5 | * Copyright (c) 2016 Tom Herbert <tom@herbertland.com> | |
9b73896a TH |
6 | */ |
7 | ||
ab7ac4eb TH |
8 | #include <linux/bpf.h> |
9 | #include <linux/errno.h> | |
10 | #include <linux/errqueue.h> | |
11 | #include <linux/file.h> | |
b6459415 | 12 | #include <linux/filter.h> |
ab7ac4eb TH |
13 | #include <linux/in.h> |
14 | #include <linux/kernel.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/net.h> | |
17 | #include <linux/netdevice.h> | |
18 | #include <linux/poll.h> | |
19 | #include <linux/rculist.h> | |
20 | #include <linux/skbuff.h> | |
21 | #include <linux/socket.h> | |
22 | #include <linux/uaccess.h> | |
23 | #include <linux/workqueue.h> | |
c0338aff | 24 | #include <linux/syscalls.h> |
174cd4b1 IM |
25 | #include <linux/sched/signal.h> |
26 | ||
ab7ac4eb TH |
27 | #include <net/kcm.h> |
28 | #include <net/netns/generic.h> | |
29 | #include <net/sock.h> | |
ab7ac4eb TH |
30 | #include <uapi/linux/kcm.h> |
31 | ||
32 | unsigned int kcm_net_id; | |
33 | ||
34 | static struct kmem_cache *kcm_psockp __read_mostly; | |
35 | static struct kmem_cache *kcm_muxp __read_mostly; | |
36 | static struct workqueue_struct *kcm_wq; | |
37 | ||
38 | static inline struct kcm_sock *kcm_sk(const struct sock *sk) | |
39 | { | |
40 | return (struct kcm_sock *)sk; | |
41 | } | |
42 | ||
43 | static inline struct kcm_tx_msg *kcm_tx_msg(struct sk_buff *skb) | |
44 | { | |
45 | return (struct kcm_tx_msg *)skb->cb; | |
46 | } | |
47 | ||
ab7ac4eb TH |
48 | static void report_csk_error(struct sock *csk, int err) |
49 | { | |
50 | csk->sk_err = EPIPE; | |
e3ae2365 | 51 | sk_error_report(csk); |
ab7ac4eb TH |
52 | } |
53 | ||
ab7ac4eb TH |
54 | static void kcm_abort_tx_psock(struct kcm_psock *psock, int err, |
55 | bool wakeup_kcm) | |
56 | { | |
57 | struct sock *csk = psock->sk; | |
58 | struct kcm_mux *mux = psock->mux; | |
59 | ||
60 | /* Unrecoverable error in transmit */ | |
61 | ||
62 | spin_lock_bh(&mux->lock); | |
63 | ||
64 | if (psock->tx_stopped) { | |
65 | spin_unlock_bh(&mux->lock); | |
66 | return; | |
67 | } | |
68 | ||
69 | psock->tx_stopped = 1; | |
cd6e111b | 70 | KCM_STATS_INCR(psock->stats.tx_aborts); |
ab7ac4eb TH |
71 | |
72 | if (!psock->tx_kcm) { | |
73 | /* Take off psocks_avail list */ | |
74 | list_del(&psock->psock_avail_list); | |
75 | } else if (wakeup_kcm) { | |
76 | /* In this case psock is being aborted while outside of | |
77 | * write_msgs and psock is reserved. Schedule tx_work | |
78 | * to handle the failure there. Need to commit tx_stopped | |
79 | * before queuing work. | |
80 | */ | |
81 | smp_mb(); | |
82 | ||
83 | queue_work(kcm_wq, &psock->tx_kcm->tx_work); | |
84 | } | |
85 | ||
86 | spin_unlock_bh(&mux->lock); | |
87 | ||
88 | /* Report error on lower socket */ | |
89 | report_csk_error(csk, err); | |
90 | } | |
91 | ||
cd6e111b TH |
92 | /* RX mux lock held. */ |
93 | static void kcm_update_rx_mux_stats(struct kcm_mux *mux, | |
94 | struct kcm_psock *psock) | |
95 | { | |
9b73896a | 96 | STRP_STATS_ADD(mux->stats.rx_bytes, |
bbb03029 | 97 | psock->strp.stats.bytes - |
9b73896a | 98 | psock->saved_rx_bytes); |
cd6e111b | 99 | mux->stats.rx_msgs += |
bbb03029 TH |
100 | psock->strp.stats.msgs - psock->saved_rx_msgs; |
101 | psock->saved_rx_msgs = psock->strp.stats.msgs; | |
102 | psock->saved_rx_bytes = psock->strp.stats.bytes; | |
cd6e111b TH |
103 | } |
104 | ||
105 | static void kcm_update_tx_mux_stats(struct kcm_mux *mux, | |
106 | struct kcm_psock *psock) | |
107 | { | |
108 | KCM_STATS_ADD(mux->stats.tx_bytes, | |
109 | psock->stats.tx_bytes - psock->saved_tx_bytes); | |
110 | mux->stats.tx_msgs += | |
111 | psock->stats.tx_msgs - psock->saved_tx_msgs; | |
112 | psock->saved_tx_msgs = psock->stats.tx_msgs; | |
113 | psock->saved_tx_bytes = psock->stats.tx_bytes; | |
114 | } | |
115 | ||
ab7ac4eb TH |
116 | static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); |
117 | ||
118 | /* KCM is ready to receive messages on its queue-- either the KCM is new or | |
119 | * has become unblocked after being blocked on full socket buffer. Queue any | |
120 | * pending ready messages on a psock. RX mux lock held. | |
121 | */ | |
122 | static void kcm_rcv_ready(struct kcm_sock *kcm) | |
123 | { | |
124 | struct kcm_mux *mux = kcm->mux; | |
125 | struct kcm_psock *psock; | |
126 | struct sk_buff *skb; | |
127 | ||
128 | if (unlikely(kcm->rx_wait || kcm->rx_psock || kcm->rx_disabled)) | |
129 | return; | |
130 | ||
131 | while (unlikely((skb = __skb_dequeue(&mux->rx_hold_queue)))) { | |
132 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { | |
133 | /* Assuming buffer limit has been reached */ | |
134 | skb_queue_head(&mux->rx_hold_queue, skb); | |
135 | WARN_ON(!sk_rmem_alloc_get(&kcm->sk)); | |
136 | return; | |
137 | } | |
138 | } | |
139 | ||
140 | while (!list_empty(&mux->psocks_ready)) { | |
141 | psock = list_first_entry(&mux->psocks_ready, struct kcm_psock, | |
142 | psock_ready_list); | |
143 | ||
144 | if (kcm_queue_rcv_skb(&kcm->sk, psock->ready_rx_msg)) { | |
145 | /* Assuming buffer limit has been reached */ | |
146 | WARN_ON(!sk_rmem_alloc_get(&kcm->sk)); | |
147 | return; | |
148 | } | |
149 | ||
150 | /* Consumed the ready message on the psock. Schedule rx_work to | |
151 | * get more messages. | |
152 | */ | |
153 | list_del(&psock->psock_ready_list); | |
154 | psock->ready_rx_msg = NULL; | |
ab7ac4eb TH |
155 | /* Commit clearing of ready_rx_msg for queuing work */ |
156 | smp_mb(); | |
157 | ||
9b73896a TH |
158 | strp_unpause(&psock->strp); |
159 | strp_check_rcv(&psock->strp); | |
ab7ac4eb TH |
160 | } |
161 | ||
162 | /* Buffer limit is okay now, add to ready list */ | |
163 | list_add_tail(&kcm->wait_rx_list, | |
164 | &kcm->mux->kcm_rx_waiters); | |
0c745b51 ED |
165 | /* paired with lockless reads in kcm_rfree() */ |
166 | WRITE_ONCE(kcm->rx_wait, true); | |
ab7ac4eb TH |
167 | } |
168 | ||
169 | static void kcm_rfree(struct sk_buff *skb) | |
170 | { | |
171 | struct sock *sk = skb->sk; | |
172 | struct kcm_sock *kcm = kcm_sk(sk); | |
173 | struct kcm_mux *mux = kcm->mux; | |
174 | unsigned int len = skb->truesize; | |
175 | ||
176 | sk_mem_uncharge(sk, len); | |
177 | atomic_sub(len, &sk->sk_rmem_alloc); | |
178 | ||
179 | /* For reading rx_wait and rx_psock without holding lock */ | |
180 | smp_mb__after_atomic(); | |
181 | ||
0c745b51 | 182 | if (!READ_ONCE(kcm->rx_wait) && !READ_ONCE(kcm->rx_psock) && |
ab7ac4eb TH |
183 | sk_rmem_alloc_get(sk) < sk->sk_rcvlowat) { |
184 | spin_lock_bh(&mux->rx_lock); | |
185 | kcm_rcv_ready(kcm); | |
186 | spin_unlock_bh(&mux->rx_lock); | |
187 | } | |
188 | } | |
189 | ||
190 | static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) | |
191 | { | |
192 | struct sk_buff_head *list = &sk->sk_receive_queue; | |
193 | ||
194 | if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) | |
195 | return -ENOMEM; | |
196 | ||
197 | if (!sk_rmem_schedule(sk, skb, skb->truesize)) | |
198 | return -ENOBUFS; | |
199 | ||
200 | skb->dev = NULL; | |
201 | ||
202 | skb_orphan(skb); | |
203 | skb->sk = sk; | |
204 | skb->destructor = kcm_rfree; | |
205 | atomic_add(skb->truesize, &sk->sk_rmem_alloc); | |
206 | sk_mem_charge(sk, skb->truesize); | |
207 | ||
208 | skb_queue_tail(list, skb); | |
209 | ||
210 | if (!sock_flag(sk, SOCK_DEAD)) | |
211 | sk->sk_data_ready(sk); | |
212 | ||
213 | return 0; | |
214 | } | |
215 | ||
216 | /* Requeue received messages for a kcm socket to other kcm sockets. This is | |
217 | * called with a kcm socket is receive disabled. | |
218 | * RX mux lock held. | |
219 | */ | |
220 | static void requeue_rx_msgs(struct kcm_mux *mux, struct sk_buff_head *head) | |
221 | { | |
222 | struct sk_buff *skb; | |
223 | struct kcm_sock *kcm; | |
224 | ||
5121197e | 225 | while ((skb = skb_dequeue(head))) { |
ab7ac4eb TH |
226 | /* Reset destructor to avoid calling kcm_rcv_ready */ |
227 | skb->destructor = sock_rfree; | |
228 | skb_orphan(skb); | |
229 | try_again: | |
230 | if (list_empty(&mux->kcm_rx_waiters)) { | |
231 | skb_queue_tail(&mux->rx_hold_queue, skb); | |
232 | continue; | |
233 | } | |
234 | ||
235 | kcm = list_first_entry(&mux->kcm_rx_waiters, | |
236 | struct kcm_sock, wait_rx_list); | |
237 | ||
238 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { | |
239 | /* Should mean socket buffer full */ | |
240 | list_del(&kcm->wait_rx_list); | |
0c745b51 ED |
241 | /* paired with lockless reads in kcm_rfree() */ |
242 | WRITE_ONCE(kcm->rx_wait, false); | |
ab7ac4eb TH |
243 | |
244 | /* Commit rx_wait to read in kcm_free */ | |
245 | smp_wmb(); | |
246 | ||
247 | goto try_again; | |
248 | } | |
249 | } | |
250 | } | |
251 | ||
252 | /* Lower sock lock held */ | |
253 | static struct kcm_sock *reserve_rx_kcm(struct kcm_psock *psock, | |
254 | struct sk_buff *head) | |
255 | { | |
256 | struct kcm_mux *mux = psock->mux; | |
257 | struct kcm_sock *kcm; | |
258 | ||
259 | WARN_ON(psock->ready_rx_msg); | |
260 | ||
261 | if (psock->rx_kcm) | |
262 | return psock->rx_kcm; | |
263 | ||
264 | spin_lock_bh(&mux->rx_lock); | |
265 | ||
266 | if (psock->rx_kcm) { | |
267 | spin_unlock_bh(&mux->rx_lock); | |
268 | return psock->rx_kcm; | |
269 | } | |
270 | ||
cd6e111b TH |
271 | kcm_update_rx_mux_stats(mux, psock); |
272 | ||
ab7ac4eb TH |
273 | if (list_empty(&mux->kcm_rx_waiters)) { |
274 | psock->ready_rx_msg = head; | |
9b73896a | 275 | strp_pause(&psock->strp); |
ab7ac4eb TH |
276 | list_add_tail(&psock->psock_ready_list, |
277 | &mux->psocks_ready); | |
278 | spin_unlock_bh(&mux->rx_lock); | |
279 | return NULL; | |
280 | } | |
281 | ||
282 | kcm = list_first_entry(&mux->kcm_rx_waiters, | |
283 | struct kcm_sock, wait_rx_list); | |
284 | list_del(&kcm->wait_rx_list); | |
0c745b51 ED |
285 | /* paired with lockless reads in kcm_rfree() */ |
286 | WRITE_ONCE(kcm->rx_wait, false); | |
ab7ac4eb TH |
287 | |
288 | psock->rx_kcm = kcm; | |
15e4dabd ED |
289 | /* paired with lockless reads in kcm_rfree() */ |
290 | WRITE_ONCE(kcm->rx_psock, psock); | |
ab7ac4eb TH |
291 | |
292 | spin_unlock_bh(&mux->rx_lock); | |
293 | ||
294 | return kcm; | |
295 | } | |
296 | ||
297 | static void kcm_done(struct kcm_sock *kcm); | |
298 | ||
299 | static void kcm_done_work(struct work_struct *w) | |
300 | { | |
301 | kcm_done(container_of(w, struct kcm_sock, done_work)); | |
302 | } | |
303 | ||
304 | /* Lower sock held */ | |
305 | static void unreserve_rx_kcm(struct kcm_psock *psock, | |
306 | bool rcv_ready) | |
307 | { | |
308 | struct kcm_sock *kcm = psock->rx_kcm; | |
309 | struct kcm_mux *mux = psock->mux; | |
310 | ||
311 | if (!kcm) | |
312 | return; | |
313 | ||
314 | spin_lock_bh(&mux->rx_lock); | |
315 | ||
316 | psock->rx_kcm = NULL; | |
15e4dabd ED |
317 | /* paired with lockless reads in kcm_rfree() */ |
318 | WRITE_ONCE(kcm->rx_psock, NULL); | |
ab7ac4eb TH |
319 | |
320 | /* Commit kcm->rx_psock before sk_rmem_alloc_get to sync with | |
321 | * kcm_rfree | |
322 | */ | |
323 | smp_mb(); | |
324 | ||
325 | if (unlikely(kcm->done)) { | |
326 | spin_unlock_bh(&mux->rx_lock); | |
327 | ||
328 | /* Need to run kcm_done in a task since we need to qcquire | |
329 | * callback locks which may already be held here. | |
330 | */ | |
331 | INIT_WORK(&kcm->done_work, kcm_done_work); | |
332 | schedule_work(&kcm->done_work); | |
333 | return; | |
334 | } | |
335 | ||
336 | if (unlikely(kcm->rx_disabled)) { | |
337 | requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue); | |
338 | } else if (rcv_ready || unlikely(!sk_rmem_alloc_get(&kcm->sk))) { | |
339 | /* Check for degenerative race with rx_wait that all | |
340 | * data was dequeued (accounted for in kcm_rfree). | |
341 | */ | |
342 | kcm_rcv_ready(kcm); | |
343 | } | |
344 | spin_unlock_bh(&mux->rx_lock); | |
345 | } | |
346 | ||
ab7ac4eb | 347 | /* Lower sock lock held */ |
96a59083 | 348 | static void psock_data_ready(struct sock *sk) |
ab7ac4eb TH |
349 | { |
350 | struct kcm_psock *psock; | |
351 | ||
352 | read_lock_bh(&sk->sk_callback_lock); | |
353 | ||
354 | psock = (struct kcm_psock *)sk->sk_user_data; | |
9b73896a | 355 | if (likely(psock)) |
96a59083 | 356 | strp_data_ready(&psock->strp); |
ab7ac4eb | 357 | |
ab7ac4eb TH |
358 | read_unlock_bh(&sk->sk_callback_lock); |
359 | } | |
360 | ||
9b73896a TH |
361 | /* Called with lower sock held */ |
362 | static void kcm_rcv_strparser(struct strparser *strp, struct sk_buff *skb) | |
ab7ac4eb | 363 | { |
9b73896a TH |
364 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
365 | struct kcm_sock *kcm; | |
ab7ac4eb | 366 | |
9b73896a TH |
367 | try_queue: |
368 | kcm = reserve_rx_kcm(psock, skb); | |
369 | if (!kcm) { | |
370 | /* Unable to reserve a KCM, message is held in psock and strp | |
371 | * is paused. | |
372 | */ | |
373 | return; | |
374 | } | |
ab7ac4eb | 375 | |
9b73896a TH |
376 | if (kcm_queue_rcv_skb(&kcm->sk, skb)) { |
377 | /* Should mean socket buffer full */ | |
378 | unreserve_rx_kcm(psock, false); | |
379 | goto try_queue; | |
380 | } | |
ab7ac4eb TH |
381 | } |
382 | ||
9b73896a | 383 | static int kcm_parse_func_strparser(struct strparser *strp, struct sk_buff *skb) |
ab7ac4eb | 384 | { |
9b73896a TH |
385 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
386 | struct bpf_prog *prog = psock->bpf_prog; | |
0355d6c1 | 387 | int res; |
9b73896a | 388 | |
3d9f773c | 389 | res = bpf_prog_run_pin_on_cpu(prog, skb); |
0355d6c1 | 390 | return res; |
ab7ac4eb TH |
391 | } |
392 | ||
9b73896a | 393 | static int kcm_read_sock_done(struct strparser *strp, int err) |
ab7ac4eb | 394 | { |
9b73896a TH |
395 | struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp); |
396 | ||
397 | unreserve_rx_kcm(psock, true); | |
398 | ||
399 | return err; | |
ab7ac4eb TH |
400 | } |
401 | ||
96a59083 | 402 | static void psock_state_change(struct sock *sk) |
ab7ac4eb | 403 | { |
a9a08845 LT |
404 | /* TCP only does a EPOLLIN for a half close. Do a EPOLLHUP here |
405 | * since application will normally not poll with EPOLLIN | |
ab7ac4eb TH |
406 | * on the TCP sockets. |
407 | */ | |
408 | ||
409 | report_csk_error(sk, EPIPE); | |
410 | } | |
411 | ||
96a59083 | 412 | static void psock_write_space(struct sock *sk) |
ab7ac4eb TH |
413 | { |
414 | struct kcm_psock *psock; | |
415 | struct kcm_mux *mux; | |
416 | struct kcm_sock *kcm; | |
417 | ||
418 | read_lock_bh(&sk->sk_callback_lock); | |
419 | ||
420 | psock = (struct kcm_psock *)sk->sk_user_data; | |
421 | if (unlikely(!psock)) | |
422 | goto out; | |
ab7ac4eb TH |
423 | mux = psock->mux; |
424 | ||
425 | spin_lock_bh(&mux->lock); | |
426 | ||
427 | /* Check if the socket is reserved so someone is waiting for sending. */ | |
428 | kcm = psock->tx_kcm; | |
9b73896a | 429 | if (kcm && !unlikely(kcm->tx_stopped)) |
ab7ac4eb TH |
430 | queue_work(kcm_wq, &kcm->tx_work); |
431 | ||
432 | spin_unlock_bh(&mux->lock); | |
433 | out: | |
434 | read_unlock_bh(&sk->sk_callback_lock); | |
435 | } | |
436 | ||
437 | static void unreserve_psock(struct kcm_sock *kcm); | |
438 | ||
439 | /* kcm sock is locked. */ | |
440 | static struct kcm_psock *reserve_psock(struct kcm_sock *kcm) | |
441 | { | |
442 | struct kcm_mux *mux = kcm->mux; | |
443 | struct kcm_psock *psock; | |
444 | ||
445 | psock = kcm->tx_psock; | |
446 | ||
447 | smp_rmb(); /* Must read tx_psock before tx_wait */ | |
448 | ||
449 | if (psock) { | |
450 | WARN_ON(kcm->tx_wait); | |
451 | if (unlikely(psock->tx_stopped)) | |
452 | unreserve_psock(kcm); | |
453 | else | |
454 | return kcm->tx_psock; | |
455 | } | |
456 | ||
457 | spin_lock_bh(&mux->lock); | |
458 | ||
459 | /* Check again under lock to see if psock was reserved for this | |
460 | * psock via psock_unreserve. | |
461 | */ | |
462 | psock = kcm->tx_psock; | |
463 | if (unlikely(psock)) { | |
464 | WARN_ON(kcm->tx_wait); | |
465 | spin_unlock_bh(&mux->lock); | |
466 | return kcm->tx_psock; | |
467 | } | |
468 | ||
469 | if (!list_empty(&mux->psocks_avail)) { | |
470 | psock = list_first_entry(&mux->psocks_avail, | |
471 | struct kcm_psock, | |
472 | psock_avail_list); | |
473 | list_del(&psock->psock_avail_list); | |
474 | if (kcm->tx_wait) { | |
475 | list_del(&kcm->wait_psock_list); | |
476 | kcm->tx_wait = false; | |
477 | } | |
478 | kcm->tx_psock = psock; | |
479 | psock->tx_kcm = kcm; | |
cd6e111b | 480 | KCM_STATS_INCR(psock->stats.reserved); |
ab7ac4eb TH |
481 | } else if (!kcm->tx_wait) { |
482 | list_add_tail(&kcm->wait_psock_list, | |
483 | &mux->kcm_tx_waiters); | |
484 | kcm->tx_wait = true; | |
485 | } | |
486 | ||
487 | spin_unlock_bh(&mux->lock); | |
488 | ||
489 | return psock; | |
490 | } | |
491 | ||
492 | /* mux lock held */ | |
493 | static void psock_now_avail(struct kcm_psock *psock) | |
494 | { | |
495 | struct kcm_mux *mux = psock->mux; | |
496 | struct kcm_sock *kcm; | |
497 | ||
498 | if (list_empty(&mux->kcm_tx_waiters)) { | |
499 | list_add_tail(&psock->psock_avail_list, | |
500 | &mux->psocks_avail); | |
501 | } else { | |
502 | kcm = list_first_entry(&mux->kcm_tx_waiters, | |
503 | struct kcm_sock, | |
504 | wait_psock_list); | |
505 | list_del(&kcm->wait_psock_list); | |
506 | kcm->tx_wait = false; | |
507 | psock->tx_kcm = kcm; | |
508 | ||
509 | /* Commit before changing tx_psock since that is read in | |
510 | * reserve_psock before queuing work. | |
511 | */ | |
512 | smp_mb(); | |
513 | ||
514 | kcm->tx_psock = psock; | |
cd6e111b | 515 | KCM_STATS_INCR(psock->stats.reserved); |
ab7ac4eb TH |
516 | queue_work(kcm_wq, &kcm->tx_work); |
517 | } | |
518 | } | |
519 | ||
520 | /* kcm sock is locked. */ | |
521 | static void unreserve_psock(struct kcm_sock *kcm) | |
522 | { | |
523 | struct kcm_psock *psock; | |
524 | struct kcm_mux *mux = kcm->mux; | |
525 | ||
526 | spin_lock_bh(&mux->lock); | |
527 | ||
528 | psock = kcm->tx_psock; | |
529 | ||
530 | if (WARN_ON(!psock)) { | |
531 | spin_unlock_bh(&mux->lock); | |
532 | return; | |
533 | } | |
534 | ||
535 | smp_rmb(); /* Read tx_psock before tx_wait */ | |
536 | ||
cd6e111b TH |
537 | kcm_update_tx_mux_stats(mux, psock); |
538 | ||
ab7ac4eb TH |
539 | WARN_ON(kcm->tx_wait); |
540 | ||
541 | kcm->tx_psock = NULL; | |
542 | psock->tx_kcm = NULL; | |
cd6e111b | 543 | KCM_STATS_INCR(psock->stats.unreserved); |
ab7ac4eb TH |
544 | |
545 | if (unlikely(psock->tx_stopped)) { | |
546 | if (psock->done) { | |
547 | /* Deferred free */ | |
548 | list_del(&psock->psock_list); | |
549 | mux->psocks_cnt--; | |
550 | sock_put(psock->sk); | |
551 | fput(psock->sk->sk_socket->file); | |
552 | kmem_cache_free(kcm_psockp, psock); | |
553 | } | |
554 | ||
555 | /* Don't put back on available list */ | |
556 | ||
557 | spin_unlock_bh(&mux->lock); | |
558 | ||
559 | return; | |
560 | } | |
561 | ||
562 | psock_now_avail(psock); | |
563 | ||
564 | spin_unlock_bh(&mux->lock); | |
565 | } | |
566 | ||
cd6e111b TH |
567 | static void kcm_report_tx_retry(struct kcm_sock *kcm) |
568 | { | |
569 | struct kcm_mux *mux = kcm->mux; | |
570 | ||
571 | spin_lock_bh(&mux->lock); | |
572 | KCM_STATS_INCR(mux->stats.tx_retries); | |
573 | spin_unlock_bh(&mux->lock); | |
574 | } | |
575 | ||
ab7ac4eb TH |
576 | /* Write any messages ready on the kcm socket. Called with kcm sock lock |
577 | * held. Return bytes actually sent or error. | |
578 | */ | |
579 | static int kcm_write_msgs(struct kcm_sock *kcm) | |
580 | { | |
581 | struct sock *sk = &kcm->sk; | |
582 | struct kcm_psock *psock; | |
583 | struct sk_buff *skb, *head; | |
584 | struct kcm_tx_msg *txm; | |
585 | unsigned short fragidx, frag_offset; | |
586 | unsigned int sent, total_sent = 0; | |
587 | int ret = 0; | |
588 | ||
589 | kcm->tx_wait_more = false; | |
590 | psock = kcm->tx_psock; | |
591 | if (unlikely(psock && psock->tx_stopped)) { | |
592 | /* A reserved psock was aborted asynchronously. Unreserve | |
593 | * it and we'll retry the message. | |
594 | */ | |
595 | unreserve_psock(kcm); | |
cd6e111b | 596 | kcm_report_tx_retry(kcm); |
ab7ac4eb TH |
597 | if (skb_queue_empty(&sk->sk_write_queue)) |
598 | return 0; | |
599 | ||
600 | kcm_tx_msg(skb_peek(&sk->sk_write_queue))->sent = 0; | |
601 | ||
602 | } else if (skb_queue_empty(&sk->sk_write_queue)) { | |
603 | return 0; | |
604 | } | |
605 | ||
606 | head = skb_peek(&sk->sk_write_queue); | |
607 | txm = kcm_tx_msg(head); | |
608 | ||
609 | if (txm->sent) { | |
610 | /* Send of first skbuff in queue already in progress */ | |
611 | if (WARN_ON(!psock)) { | |
612 | ret = -EINVAL; | |
613 | goto out; | |
614 | } | |
615 | sent = txm->sent; | |
616 | frag_offset = txm->frag_offset; | |
617 | fragidx = txm->fragidx; | |
618 | skb = txm->frag_skb; | |
619 | ||
620 | goto do_frag; | |
621 | } | |
622 | ||
623 | try_again: | |
624 | psock = reserve_psock(kcm); | |
625 | if (!psock) | |
626 | goto out; | |
627 | ||
628 | do { | |
629 | skb = head; | |
630 | txm = kcm_tx_msg(head); | |
631 | sent = 0; | |
632 | ||
633 | do_frag_list: | |
634 | if (WARN_ON(!skb_shinfo(skb)->nr_frags)) { | |
635 | ret = -EINVAL; | |
636 | goto out; | |
637 | } | |
638 | ||
639 | for (fragidx = 0; fragidx < skb_shinfo(skb)->nr_frags; | |
640 | fragidx++) { | |
641 | skb_frag_t *frag; | |
642 | ||
643 | frag_offset = 0; | |
644 | do_frag: | |
645 | frag = &skb_shinfo(skb)->frags[fragidx]; | |
d8e18a51 | 646 | if (WARN_ON(!skb_frag_size(frag))) { |
ab7ac4eb TH |
647 | ret = -EINVAL; |
648 | goto out; | |
649 | } | |
650 | ||
651 | ret = kernel_sendpage(psock->sk->sk_socket, | |
d8e18a51 | 652 | skb_frag_page(frag), |
b54c9d5b | 653 | skb_frag_off(frag) + frag_offset, |
d8e18a51 | 654 | skb_frag_size(frag) - frag_offset, |
ab7ac4eb TH |
655 | MSG_DONTWAIT); |
656 | if (ret <= 0) { | |
657 | if (ret == -EAGAIN) { | |
658 | /* Save state to try again when there's | |
659 | * write space on the socket | |
660 | */ | |
661 | txm->sent = sent; | |
662 | txm->frag_offset = frag_offset; | |
663 | txm->fragidx = fragidx; | |
664 | txm->frag_skb = skb; | |
665 | ||
666 | ret = 0; | |
667 | goto out; | |
668 | } | |
669 | ||
670 | /* Hard failure in sending message, abort this | |
671 | * psock since it has lost framing | |
71a2fae5 | 672 | * synchronization and retry sending the |
ab7ac4eb TH |
673 | * message from the beginning. |
674 | */ | |
675 | kcm_abort_tx_psock(psock, ret ? -ret : EPIPE, | |
676 | true); | |
677 | unreserve_psock(kcm); | |
678 | ||
679 | txm->sent = 0; | |
cd6e111b | 680 | kcm_report_tx_retry(kcm); |
ab7ac4eb TH |
681 | ret = 0; |
682 | ||
683 | goto try_again; | |
684 | } | |
685 | ||
686 | sent += ret; | |
687 | frag_offset += ret; | |
cd6e111b | 688 | KCM_STATS_ADD(psock->stats.tx_bytes, ret); |
d8e18a51 | 689 | if (frag_offset < skb_frag_size(frag)) { |
ab7ac4eb TH |
690 | /* Not finished with this frag */ |
691 | goto do_frag; | |
692 | } | |
693 | } | |
694 | ||
695 | if (skb == head) { | |
696 | if (skb_has_frag_list(skb)) { | |
697 | skb = skb_shinfo(skb)->frag_list; | |
698 | goto do_frag_list; | |
699 | } | |
700 | } else if (skb->next) { | |
701 | skb = skb->next; | |
702 | goto do_frag_list; | |
703 | } | |
704 | ||
705 | /* Successfully sent the whole packet, account for it. */ | |
706 | skb_dequeue(&sk->sk_write_queue); | |
707 | kfree_skb(head); | |
708 | sk->sk_wmem_queued -= sent; | |
709 | total_sent += sent; | |
cd6e111b | 710 | KCM_STATS_INCR(psock->stats.tx_msgs); |
ab7ac4eb TH |
711 | } while ((head = skb_peek(&sk->sk_write_queue))); |
712 | out: | |
713 | if (!head) { | |
714 | /* Done with all queued messages. */ | |
715 | WARN_ON(!skb_queue_empty(&sk->sk_write_queue)); | |
716 | unreserve_psock(kcm); | |
717 | } | |
718 | ||
719 | /* Check if write space is available */ | |
720 | sk->sk_write_space(sk); | |
721 | ||
722 | return total_sent ? : ret; | |
723 | } | |
724 | ||
725 | static void kcm_tx_work(struct work_struct *w) | |
726 | { | |
727 | struct kcm_sock *kcm = container_of(w, struct kcm_sock, tx_work); | |
728 | struct sock *sk = &kcm->sk; | |
729 | int err; | |
730 | ||
731 | lock_sock(sk); | |
732 | ||
733 | /* Primarily for SOCK_DGRAM sockets, also handle asynchronous tx | |
734 | * aborts | |
735 | */ | |
736 | err = kcm_write_msgs(kcm); | |
737 | if (err < 0) { | |
738 | /* Hard failure in write, report error on KCM socket */ | |
739 | pr_warn("KCM: Hard failure on kcm_write_msgs %d\n", err); | |
740 | report_csk_error(&kcm->sk, -err); | |
741 | goto out; | |
742 | } | |
743 | ||
744 | /* Primarily for SOCK_SEQPACKET sockets */ | |
745 | if (likely(sk->sk_socket) && | |
746 | test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { | |
747 | clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
748 | sk->sk_write_space(sk); | |
749 | } | |
750 | ||
751 | out: | |
752 | release_sock(sk); | |
753 | } | |
754 | ||
755 | static void kcm_push(struct kcm_sock *kcm) | |
756 | { | |
757 | if (kcm->tx_wait_more) | |
758 | kcm_write_msgs(kcm); | |
759 | } | |
760 | ||
f29698fc TH |
761 | static ssize_t kcm_sendpage(struct socket *sock, struct page *page, |
762 | int offset, size_t size, int flags) | |
763 | ||
764 | { | |
765 | struct sock *sk = sock->sk; | |
766 | struct kcm_sock *kcm = kcm_sk(sk); | |
767 | struct sk_buff *skb = NULL, *head = NULL; | |
768 | long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT); | |
769 | bool eor; | |
770 | int err = 0; | |
771 | int i; | |
772 | ||
773 | if (flags & MSG_SENDPAGE_NOTLAST) | |
774 | flags |= MSG_MORE; | |
775 | ||
776 | /* No MSG_EOR from splice, only look at MSG_MORE */ | |
777 | eor = !(flags & MSG_MORE); | |
778 | ||
779 | lock_sock(sk); | |
780 | ||
781 | sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); | |
782 | ||
783 | err = -EPIPE; | |
784 | if (sk->sk_err) | |
785 | goto out_error; | |
786 | ||
787 | if (kcm->seq_skb) { | |
788 | /* Previously opened message */ | |
789 | head = kcm->seq_skb; | |
790 | skb = kcm_tx_msg(head)->last_skb; | |
791 | i = skb_shinfo(skb)->nr_frags; | |
792 | ||
793 | if (skb_can_coalesce(skb, i, page, offset)) { | |
794 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], size); | |
06b4feb3 | 795 | skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG; |
f29698fc TH |
796 | goto coalesced; |
797 | } | |
798 | ||
799 | if (i >= MAX_SKB_FRAGS) { | |
800 | struct sk_buff *tskb; | |
801 | ||
802 | tskb = alloc_skb(0, sk->sk_allocation); | |
803 | while (!tskb) { | |
804 | kcm_push(kcm); | |
805 | err = sk_stream_wait_memory(sk, &timeo); | |
806 | if (err) | |
807 | goto out_error; | |
808 | } | |
809 | ||
810 | if (head == skb) | |
811 | skb_shinfo(head)->frag_list = tskb; | |
812 | else | |
813 | skb->next = tskb; | |
814 | ||
815 | skb = tskb; | |
816 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
817 | i = 0; | |
818 | } | |
819 | } else { | |
820 | /* Call the sk_stream functions to manage the sndbuf mem. */ | |
821 | if (!sk_stream_memory_free(sk)) { | |
822 | kcm_push(kcm); | |
823 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
824 | err = sk_stream_wait_memory(sk, &timeo); | |
825 | if (err) | |
826 | goto out_error; | |
827 | } | |
828 | ||
829 | head = alloc_skb(0, sk->sk_allocation); | |
830 | while (!head) { | |
831 | kcm_push(kcm); | |
832 | err = sk_stream_wait_memory(sk, &timeo); | |
833 | if (err) | |
834 | goto out_error; | |
835 | } | |
836 | ||
837 | skb = head; | |
838 | i = 0; | |
839 | } | |
840 | ||
841 | get_page(page); | |
ee15e1f3 | 842 | skb_fill_page_desc_noacc(skb, i, page, offset, size); |
06b4feb3 | 843 | skb_shinfo(skb)->flags |= SKBFL_SHARED_FRAG; |
f29698fc TH |
844 | |
845 | coalesced: | |
846 | skb->len += size; | |
847 | skb->data_len += size; | |
848 | skb->truesize += size; | |
849 | sk->sk_wmem_queued += size; | |
850 | sk_mem_charge(sk, size); | |
851 | ||
852 | if (head != skb) { | |
853 | head->len += size; | |
854 | head->data_len += size; | |
855 | head->truesize += size; | |
856 | } | |
857 | ||
858 | if (eor) { | |
859 | bool not_busy = skb_queue_empty(&sk->sk_write_queue); | |
860 | ||
861 | /* Message complete, queue it on send buffer */ | |
862 | __skb_queue_tail(&sk->sk_write_queue, head); | |
863 | kcm->seq_skb = NULL; | |
864 | KCM_STATS_INCR(kcm->stats.tx_msgs); | |
865 | ||
866 | if (flags & MSG_BATCH) { | |
867 | kcm->tx_wait_more = true; | |
868 | } else if (kcm->tx_wait_more || not_busy) { | |
869 | err = kcm_write_msgs(kcm); | |
870 | if (err < 0) { | |
871 | /* We got a hard error in write_msgs but have | |
872 | * already queued this message. Report an error | |
873 | * in the socket, but don't affect return value | |
874 | * from sendmsg | |
875 | */ | |
876 | pr_warn("KCM: Hard failure on kcm_write_msgs\n"); | |
877 | report_csk_error(&kcm->sk, -err); | |
878 | } | |
879 | } | |
880 | } else { | |
881 | /* Message not complete, save state */ | |
882 | kcm->seq_skb = head; | |
883 | kcm_tx_msg(head)->last_skb = skb; | |
884 | } | |
885 | ||
886 | KCM_STATS_ADD(kcm->stats.tx_bytes, size); | |
887 | ||
888 | release_sock(sk); | |
889 | return size; | |
890 | ||
891 | out_error: | |
892 | kcm_push(kcm); | |
893 | ||
894 | err = sk_stream_error(sk, flags, err); | |
895 | ||
896 | /* make sure we wake any epoll edge trigger waiter */ | |
897 | if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) | |
898 | sk->sk_write_space(sk); | |
899 | ||
900 | release_sock(sk); | |
901 | return err; | |
902 | } | |
903 | ||
ab7ac4eb TH |
904 | static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) |
905 | { | |
906 | struct sock *sk = sock->sk; | |
907 | struct kcm_sock *kcm = kcm_sk(sk); | |
908 | struct sk_buff *skb = NULL, *head = NULL; | |
909 | size_t copy, copied = 0; | |
910 | long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); | |
911 | int eor = (sock->type == SOCK_DGRAM) ? | |
912 | !(msg->msg_flags & MSG_MORE) : !!(msg->msg_flags & MSG_EOR); | |
913 | int err = -EPIPE; | |
914 | ||
915 | lock_sock(sk); | |
916 | ||
917 | /* Per tcp_sendmsg this should be in poll */ | |
918 | sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk); | |
919 | ||
920 | if (sk->sk_err) | |
921 | goto out_error; | |
922 | ||
923 | if (kcm->seq_skb) { | |
924 | /* Previously opened message */ | |
925 | head = kcm->seq_skb; | |
926 | skb = kcm_tx_msg(head)->last_skb; | |
927 | goto start; | |
928 | } | |
929 | ||
930 | /* Call the sk_stream functions to manage the sndbuf mem. */ | |
931 | if (!sk_stream_memory_free(sk)) { | |
932 | kcm_push(kcm); | |
933 | set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); | |
934 | err = sk_stream_wait_memory(sk, &timeo); | |
935 | if (err) | |
936 | goto out_error; | |
937 | } | |
938 | ||
98e3862c WC |
939 | if (msg_data_left(msg)) { |
940 | /* New message, alloc head skb */ | |
ab7ac4eb | 941 | head = alloc_skb(0, sk->sk_allocation); |
98e3862c WC |
942 | while (!head) { |
943 | kcm_push(kcm); | |
944 | err = sk_stream_wait_memory(sk, &timeo); | |
945 | if (err) | |
946 | goto out_error; | |
ab7ac4eb | 947 | |
98e3862c WC |
948 | head = alloc_skb(0, sk->sk_allocation); |
949 | } | |
ab7ac4eb | 950 | |
98e3862c WC |
951 | skb = head; |
952 | ||
953 | /* Set ip_summed to CHECKSUM_UNNECESSARY to avoid calling | |
954 | * csum_and_copy_from_iter from skb_do_copy_data_nocache. | |
955 | */ | |
956 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
957 | } | |
ab7ac4eb TH |
958 | |
959 | start: | |
960 | while (msg_data_left(msg)) { | |
961 | bool merge = true; | |
962 | int i = skb_shinfo(skb)->nr_frags; | |
963 | struct page_frag *pfrag = sk_page_frag(sk); | |
964 | ||
965 | if (!sk_page_frag_refill(sk, pfrag)) | |
966 | goto wait_for_memory; | |
967 | ||
968 | if (!skb_can_coalesce(skb, i, pfrag->page, | |
969 | pfrag->offset)) { | |
970 | if (i == MAX_SKB_FRAGS) { | |
971 | struct sk_buff *tskb; | |
972 | ||
973 | tskb = alloc_skb(0, sk->sk_allocation); | |
974 | if (!tskb) | |
975 | goto wait_for_memory; | |
976 | ||
977 | if (head == skb) | |
978 | skb_shinfo(head)->frag_list = tskb; | |
979 | else | |
980 | skb->next = tskb; | |
981 | ||
982 | skb = tskb; | |
983 | skb->ip_summed = CHECKSUM_UNNECESSARY; | |
984 | continue; | |
985 | } | |
986 | merge = false; | |
987 | } | |
988 | ||
989 | copy = min_t(int, msg_data_left(msg), | |
990 | pfrag->size - pfrag->offset); | |
991 | ||
992 | if (!sk_wmem_schedule(sk, copy)) | |
993 | goto wait_for_memory; | |
994 | ||
995 | err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb, | |
996 | pfrag->page, | |
997 | pfrag->offset, | |
998 | copy); | |
999 | if (err) | |
1000 | goto out_error; | |
1001 | ||
1002 | /* Update the skb. */ | |
1003 | if (merge) { | |
1004 | skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); | |
1005 | } else { | |
1006 | skb_fill_page_desc(skb, i, pfrag->page, | |
1007 | pfrag->offset, copy); | |
1008 | get_page(pfrag->page); | |
1009 | } | |
1010 | ||
1011 | pfrag->offset += copy; | |
1012 | copied += copy; | |
1013 | if (head != skb) { | |
1014 | head->len += copy; | |
1015 | head->data_len += copy; | |
1016 | } | |
1017 | ||
1018 | continue; | |
1019 | ||
1020 | wait_for_memory: | |
1021 | kcm_push(kcm); | |
1022 | err = sk_stream_wait_memory(sk, &timeo); | |
1023 | if (err) | |
1024 | goto out_error; | |
1025 | } | |
1026 | ||
1027 | if (eor) { | |
1028 | bool not_busy = skb_queue_empty(&sk->sk_write_queue); | |
1029 | ||
98e3862c WC |
1030 | if (head) { |
1031 | /* Message complete, queue it on send buffer */ | |
1032 | __skb_queue_tail(&sk->sk_write_queue, head); | |
1033 | kcm->seq_skb = NULL; | |
1034 | KCM_STATS_INCR(kcm->stats.tx_msgs); | |
1035 | } | |
ab7ac4eb TH |
1036 | |
1037 | if (msg->msg_flags & MSG_BATCH) { | |
1038 | kcm->tx_wait_more = true; | |
1039 | } else if (kcm->tx_wait_more || not_busy) { | |
1040 | err = kcm_write_msgs(kcm); | |
1041 | if (err < 0) { | |
1042 | /* We got a hard error in write_msgs but have | |
1043 | * already queued this message. Report an error | |
1044 | * in the socket, but don't affect return value | |
1045 | * from sendmsg | |
1046 | */ | |
1047 | pr_warn("KCM: Hard failure on kcm_write_msgs\n"); | |
1048 | report_csk_error(&kcm->sk, -err); | |
1049 | } | |
1050 | } | |
1051 | } else { | |
1052 | /* Message not complete, save state */ | |
1053 | partial_message: | |
cd27b96b WC |
1054 | if (head) { |
1055 | kcm->seq_skb = head; | |
1056 | kcm_tx_msg(head)->last_skb = skb; | |
1057 | } | |
ab7ac4eb TH |
1058 | } |
1059 | ||
cd6e111b TH |
1060 | KCM_STATS_ADD(kcm->stats.tx_bytes, copied); |
1061 | ||
ab7ac4eb TH |
1062 | release_sock(sk); |
1063 | return copied; | |
1064 | ||
1065 | out_error: | |
1066 | kcm_push(kcm); | |
1067 | ||
1068 | if (copied && sock->type == SOCK_SEQPACKET) { | |
1069 | /* Wrote some bytes before encountering an | |
1070 | * error, return partial success. | |
1071 | */ | |
1072 | goto partial_message; | |
1073 | } | |
1074 | ||
1075 | if (head != kcm->seq_skb) | |
1076 | kfree_skb(head); | |
1077 | ||
1078 | err = sk_stream_error(sk, msg->msg_flags, err); | |
1079 | ||
1080 | /* make sure we wake any epoll edge trigger waiter */ | |
1081 | if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN)) | |
1082 | sk->sk_write_space(sk); | |
1083 | ||
1084 | release_sock(sk); | |
1085 | return err; | |
1086 | } | |
1087 | ||
ab7ac4eb TH |
1088 | static int kcm_recvmsg(struct socket *sock, struct msghdr *msg, |
1089 | size_t len, int flags) | |
1090 | { | |
1091 | struct sock *sk = sock->sk; | |
cd6e111b | 1092 | struct kcm_sock *kcm = kcm_sk(sk); |
ab7ac4eb | 1093 | int err = 0; |
bbb03029 | 1094 | struct strp_msg *stm; |
ab7ac4eb TH |
1095 | int copied = 0; |
1096 | struct sk_buff *skb; | |
1097 | ||
5121197e | 1098 | skb = skb_recv_datagram(sk, flags, &err); |
ab7ac4eb TH |
1099 | if (!skb) |
1100 | goto out; | |
1101 | ||
1102 | /* Okay, have a message on the receive queue */ | |
1103 | ||
bbb03029 | 1104 | stm = strp_msg(skb); |
ab7ac4eb | 1105 | |
bbb03029 TH |
1106 | if (len > stm->full_len) |
1107 | len = stm->full_len; | |
ab7ac4eb | 1108 | |
bbb03029 | 1109 | err = skb_copy_datagram_msg(skb, stm->offset, msg, len); |
ab7ac4eb TH |
1110 | if (err < 0) |
1111 | goto out; | |
1112 | ||
1113 | copied = len; | |
1114 | if (likely(!(flags & MSG_PEEK))) { | |
cd6e111b | 1115 | KCM_STATS_ADD(kcm->stats.rx_bytes, copied); |
bbb03029 | 1116 | if (copied < stm->full_len) { |
ab7ac4eb TH |
1117 | if (sock->type == SOCK_DGRAM) { |
1118 | /* Truncated message */ | |
1119 | msg->msg_flags |= MSG_TRUNC; | |
1120 | goto msg_finished; | |
1121 | } | |
bbb03029 TH |
1122 | stm->offset += copied; |
1123 | stm->full_len -= copied; | |
ab7ac4eb TH |
1124 | } else { |
1125 | msg_finished: | |
1126 | /* Finished with message */ | |
1127 | msg->msg_flags |= MSG_EOR; | |
cd6e111b | 1128 | KCM_STATS_INCR(kcm->stats.rx_msgs); |
ab7ac4eb TH |
1129 | } |
1130 | } | |
1131 | ||
1132 | out: | |
5121197e | 1133 | skb_free_datagram(sk, skb); |
ab7ac4eb TH |
1134 | return copied ? : err; |
1135 | } | |
1136 | ||
91687355 TH |
1137 | static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos, |
1138 | struct pipe_inode_info *pipe, size_t len, | |
1139 | unsigned int flags) | |
1140 | { | |
1141 | struct sock *sk = sock->sk; | |
1142 | struct kcm_sock *kcm = kcm_sk(sk); | |
bbb03029 | 1143 | struct strp_msg *stm; |
91687355 | 1144 | int err = 0; |
f1971a2e | 1145 | ssize_t copied; |
91687355 TH |
1146 | struct sk_buff *skb; |
1147 | ||
1148 | /* Only support splice for SOCKSEQPACKET */ | |
1149 | ||
5121197e | 1150 | skb = skb_recv_datagram(sk, flags, &err); |
91687355 TH |
1151 | if (!skb) |
1152 | goto err_out; | |
1153 | ||
1154 | /* Okay, have a message on the receive queue */ | |
1155 | ||
bbb03029 | 1156 | stm = strp_msg(skb); |
91687355 | 1157 | |
bbb03029 TH |
1158 | if (len > stm->full_len) |
1159 | len = stm->full_len; | |
91687355 | 1160 | |
bbb03029 | 1161 | copied = skb_splice_bits(skb, sk, stm->offset, pipe, len, flags); |
91687355 TH |
1162 | if (copied < 0) { |
1163 | err = copied; | |
1164 | goto err_out; | |
1165 | } | |
1166 | ||
1167 | KCM_STATS_ADD(kcm->stats.rx_bytes, copied); | |
1168 | ||
bbb03029 TH |
1169 | stm->offset += copied; |
1170 | stm->full_len -= copied; | |
91687355 TH |
1171 | |
1172 | /* We have no way to return MSG_EOR. If all the bytes have been | |
1173 | * read we still leave the message in the receive socket buffer. | |
1174 | * A subsequent recvmsg needs to be done to return MSG_EOR and | |
1175 | * finish reading the message. | |
1176 | */ | |
1177 | ||
5121197e | 1178 | skb_free_datagram(sk, skb); |
91687355 TH |
1179 | return copied; |
1180 | ||
1181 | err_out: | |
5121197e | 1182 | skb_free_datagram(sk, skb); |
91687355 TH |
1183 | return err; |
1184 | } | |
1185 | ||
ab7ac4eb TH |
1186 | /* kcm sock lock held */ |
1187 | static void kcm_recv_disable(struct kcm_sock *kcm) | |
1188 | { | |
1189 | struct kcm_mux *mux = kcm->mux; | |
1190 | ||
1191 | if (kcm->rx_disabled) | |
1192 | return; | |
1193 | ||
1194 | spin_lock_bh(&mux->rx_lock); | |
1195 | ||
1196 | kcm->rx_disabled = 1; | |
1197 | ||
1198 | /* If a psock is reserved we'll do cleanup in unreserve */ | |
1199 | if (!kcm->rx_psock) { | |
1200 | if (kcm->rx_wait) { | |
1201 | list_del(&kcm->wait_rx_list); | |
0c745b51 ED |
1202 | /* paired with lockless reads in kcm_rfree() */ |
1203 | WRITE_ONCE(kcm->rx_wait, false); | |
ab7ac4eb TH |
1204 | } |
1205 | ||
1206 | requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue); | |
1207 | } | |
1208 | ||
1209 | spin_unlock_bh(&mux->rx_lock); | |
1210 | } | |
1211 | ||
1212 | /* kcm sock lock held */ | |
1213 | static void kcm_recv_enable(struct kcm_sock *kcm) | |
1214 | { | |
1215 | struct kcm_mux *mux = kcm->mux; | |
1216 | ||
1217 | if (!kcm->rx_disabled) | |
1218 | return; | |
1219 | ||
1220 | spin_lock_bh(&mux->rx_lock); | |
1221 | ||
1222 | kcm->rx_disabled = 0; | |
1223 | kcm_rcv_ready(kcm); | |
1224 | ||
1225 | spin_unlock_bh(&mux->rx_lock); | |
1226 | } | |
1227 | ||
1228 | static int kcm_setsockopt(struct socket *sock, int level, int optname, | |
a7b75c5a | 1229 | sockptr_t optval, unsigned int optlen) |
ab7ac4eb TH |
1230 | { |
1231 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1232 | int val, valbool; | |
1233 | int err = 0; | |
1234 | ||
1235 | if (level != SOL_KCM) | |
1236 | return -ENOPROTOOPT; | |
1237 | ||
1238 | if (optlen < sizeof(int)) | |
1239 | return -EINVAL; | |
1240 | ||
a7b75c5a CH |
1241 | if (copy_from_sockptr(&val, optval, sizeof(int))) |
1242 | return -EFAULT; | |
ab7ac4eb TH |
1243 | |
1244 | valbool = val ? 1 : 0; | |
1245 | ||
1246 | switch (optname) { | |
1247 | case KCM_RECV_DISABLE: | |
1248 | lock_sock(&kcm->sk); | |
1249 | if (valbool) | |
1250 | kcm_recv_disable(kcm); | |
1251 | else | |
1252 | kcm_recv_enable(kcm); | |
1253 | release_sock(&kcm->sk); | |
1254 | break; | |
1255 | default: | |
1256 | err = -ENOPROTOOPT; | |
1257 | } | |
1258 | ||
1259 | return err; | |
1260 | } | |
1261 | ||
1262 | static int kcm_getsockopt(struct socket *sock, int level, int optname, | |
1263 | char __user *optval, int __user *optlen) | |
1264 | { | |
1265 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1266 | int val, len; | |
1267 | ||
1268 | if (level != SOL_KCM) | |
1269 | return -ENOPROTOOPT; | |
1270 | ||
1271 | if (get_user(len, optlen)) | |
1272 | return -EFAULT; | |
1273 | ||
1274 | len = min_t(unsigned int, len, sizeof(int)); | |
1275 | if (len < 0) | |
1276 | return -EINVAL; | |
1277 | ||
1278 | switch (optname) { | |
1279 | case KCM_RECV_DISABLE: | |
1280 | val = kcm->rx_disabled; | |
1281 | break; | |
1282 | default: | |
1283 | return -ENOPROTOOPT; | |
1284 | } | |
1285 | ||
1286 | if (put_user(len, optlen)) | |
1287 | return -EFAULT; | |
1288 | if (copy_to_user(optval, &val, len)) | |
1289 | return -EFAULT; | |
1290 | return 0; | |
1291 | } | |
1292 | ||
1293 | static void init_kcm_sock(struct kcm_sock *kcm, struct kcm_mux *mux) | |
1294 | { | |
1295 | struct kcm_sock *tkcm; | |
1296 | struct list_head *head; | |
1297 | int index = 0; | |
1298 | ||
a11e1d43 LT |
1299 | /* For SOCK_SEQPACKET sock type, datagram_poll checks the sk_state, so |
1300 | * we set sk_state, otherwise epoll_wait always returns right away with | |
1301 | * EPOLLHUP | |
ab7ac4eb TH |
1302 | */ |
1303 | kcm->sk.sk_state = TCP_ESTABLISHED; | |
1304 | ||
1305 | /* Add to mux's kcm sockets list */ | |
1306 | kcm->mux = mux; | |
1307 | spin_lock_bh(&mux->lock); | |
1308 | ||
1309 | head = &mux->kcm_socks; | |
1310 | list_for_each_entry(tkcm, &mux->kcm_socks, kcm_sock_list) { | |
1311 | if (tkcm->index != index) | |
1312 | break; | |
1313 | head = &tkcm->kcm_sock_list; | |
1314 | index++; | |
1315 | } | |
1316 | ||
1317 | list_add(&kcm->kcm_sock_list, head); | |
1318 | kcm->index = index; | |
1319 | ||
1320 | mux->kcm_socks_cnt++; | |
1321 | spin_unlock_bh(&mux->lock); | |
1322 | ||
1323 | INIT_WORK(&kcm->tx_work, kcm_tx_work); | |
1324 | ||
1325 | spin_lock_bh(&mux->rx_lock); | |
1326 | kcm_rcv_ready(kcm); | |
1327 | spin_unlock_bh(&mux->rx_lock); | |
1328 | } | |
1329 | ||
1330 | static int kcm_attach(struct socket *sock, struct socket *csock, | |
1331 | struct bpf_prog *prog) | |
1332 | { | |
1333 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1334 | struct kcm_mux *mux = kcm->mux; | |
1335 | struct sock *csk; | |
1336 | struct kcm_psock *psock = NULL, *tpsock; | |
1337 | struct list_head *head; | |
1338 | int index = 0; | |
3fd87127 EB |
1339 | static const struct strp_callbacks cb = { |
1340 | .rcv_msg = kcm_rcv_strparser, | |
1341 | .parse_msg = kcm_parse_func_strparser, | |
1342 | .read_sock_done = kcm_read_sock_done, | |
1343 | }; | |
2cc683e8 | 1344 | int err = 0; |
ab7ac4eb TH |
1345 | |
1346 | csk = csock->sk; | |
1347 | if (!csk) | |
1348 | return -EINVAL; | |
1349 | ||
2cc683e8 TH |
1350 | lock_sock(csk); |
1351 | ||
581e7226 TH |
1352 | /* Only allow TCP sockets to be attached for now */ |
1353 | if ((csk->sk_family != AF_INET && csk->sk_family != AF_INET6) || | |
2cc683e8 TH |
1354 | csk->sk_protocol != IPPROTO_TCP) { |
1355 | err = -EOPNOTSUPP; | |
1356 | goto out; | |
1357 | } | |
581e7226 TH |
1358 | |
1359 | /* Don't allow listeners or closed sockets */ | |
2cc683e8 TH |
1360 | if (csk->sk_state == TCP_LISTEN || csk->sk_state == TCP_CLOSE) { |
1361 | err = -EOPNOTSUPP; | |
1362 | goto out; | |
1363 | } | |
351050ec | 1364 | |
ab7ac4eb | 1365 | psock = kmem_cache_zalloc(kcm_psockp, GFP_KERNEL); |
2cc683e8 TH |
1366 | if (!psock) { |
1367 | err = -ENOMEM; | |
1368 | goto out; | |
1369 | } | |
ab7ac4eb TH |
1370 | |
1371 | psock->mux = mux; | |
1372 | psock->sk = csk; | |
1373 | psock->bpf_prog = prog; | |
29152a34 | 1374 | |
ab7ac4eb | 1375 | write_lock_bh(&csk->sk_callback_lock); |
e5571240 | 1376 | |
71a2fae5 | 1377 | /* Check if sk_user_data is already by KCM or someone else. |
e5571240 TH |
1378 | * Must be done under lock to prevent race conditions. |
1379 | */ | |
1380 | if (csk->sk_user_data) { | |
1381 | write_unlock_bh(&csk->sk_callback_lock); | |
e5571240 | 1382 | kmem_cache_free(kcm_psockp, psock); |
2cc683e8 TH |
1383 | err = -EALREADY; |
1384 | goto out; | |
e5571240 TH |
1385 | } |
1386 | ||
8fc29ff3 CW |
1387 | err = strp_init(&psock->strp, csk, &cb); |
1388 | if (err) { | |
1389 | write_unlock_bh(&csk->sk_callback_lock); | |
1390 | kmem_cache_free(kcm_psockp, psock); | |
1391 | goto out; | |
1392 | } | |
1393 | ||
ab7ac4eb TH |
1394 | psock->save_data_ready = csk->sk_data_ready; |
1395 | psock->save_write_space = csk->sk_write_space; | |
1396 | psock->save_state_change = csk->sk_state_change; | |
1397 | csk->sk_user_data = psock; | |
96a59083 TH |
1398 | csk->sk_data_ready = psock_data_ready; |
1399 | csk->sk_write_space = psock_write_space; | |
1400 | csk->sk_state_change = psock_state_change; | |
e5571240 | 1401 | |
ab7ac4eb TH |
1402 | write_unlock_bh(&csk->sk_callback_lock); |
1403 | ||
e5571240 TH |
1404 | sock_hold(csk); |
1405 | ||
ab7ac4eb TH |
1406 | /* Finished initialization, now add the psock to the MUX. */ |
1407 | spin_lock_bh(&mux->lock); | |
1408 | head = &mux->psocks; | |
1409 | list_for_each_entry(tpsock, &mux->psocks, psock_list) { | |
1410 | if (tpsock->index != index) | |
1411 | break; | |
1412 | head = &tpsock->psock_list; | |
1413 | index++; | |
1414 | } | |
1415 | ||
1416 | list_add(&psock->psock_list, head); | |
1417 | psock->index = index; | |
1418 | ||
cd6e111b | 1419 | KCM_STATS_INCR(mux->stats.psock_attach); |
ab7ac4eb TH |
1420 | mux->psocks_cnt++; |
1421 | psock_now_avail(psock); | |
1422 | spin_unlock_bh(&mux->lock); | |
1423 | ||
1424 | /* Schedule RX work in case there are already bytes queued */ | |
9b73896a | 1425 | strp_check_rcv(&psock->strp); |
ab7ac4eb | 1426 | |
2cc683e8 TH |
1427 | out: |
1428 | release_sock(csk); | |
1429 | ||
1430 | return err; | |
ab7ac4eb TH |
1431 | } |
1432 | ||
1433 | static int kcm_attach_ioctl(struct socket *sock, struct kcm_attach *info) | |
1434 | { | |
1435 | struct socket *csock; | |
1436 | struct bpf_prog *prog; | |
1437 | int err; | |
1438 | ||
1439 | csock = sockfd_lookup(info->fd, &err); | |
1440 | if (!csock) | |
1441 | return -ENOENT; | |
1442 | ||
113214be | 1443 | prog = bpf_prog_get_type(info->bpf_fd, BPF_PROG_TYPE_SOCKET_FILTER); |
ab7ac4eb TH |
1444 | if (IS_ERR(prog)) { |
1445 | err = PTR_ERR(prog); | |
1446 | goto out; | |
1447 | } | |
1448 | ||
ab7ac4eb TH |
1449 | err = kcm_attach(sock, csock, prog); |
1450 | if (err) { | |
1451 | bpf_prog_put(prog); | |
1452 | goto out; | |
1453 | } | |
1454 | ||
1455 | /* Keep reference on file also */ | |
1456 | ||
1457 | return 0; | |
1458 | out: | |
8dc879a1 | 1459 | sockfd_put(csock); |
ab7ac4eb TH |
1460 | return err; |
1461 | } | |
1462 | ||
1463 | static void kcm_unattach(struct kcm_psock *psock) | |
1464 | { | |
1465 | struct sock *csk = psock->sk; | |
1466 | struct kcm_mux *mux = psock->mux; | |
1467 | ||
1616b38f TH |
1468 | lock_sock(csk); |
1469 | ||
ab7ac4eb TH |
1470 | /* Stop getting callbacks from TCP socket. After this there should |
1471 | * be no way to reserve a kcm for this psock. | |
1472 | */ | |
1473 | write_lock_bh(&csk->sk_callback_lock); | |
1474 | csk->sk_user_data = NULL; | |
1475 | csk->sk_data_ready = psock->save_data_ready; | |
1476 | csk->sk_write_space = psock->save_write_space; | |
1477 | csk->sk_state_change = psock->save_state_change; | |
9b73896a | 1478 | strp_stop(&psock->strp); |
ab7ac4eb TH |
1479 | |
1480 | if (WARN_ON(psock->rx_kcm)) { | |
1481 | write_unlock_bh(&csk->sk_callback_lock); | |
2cc683e8 | 1482 | release_sock(csk); |
ab7ac4eb TH |
1483 | return; |
1484 | } | |
1485 | ||
1486 | spin_lock_bh(&mux->rx_lock); | |
1487 | ||
1488 | /* Stop receiver activities. After this point psock should not be | |
1489 | * able to get onto ready list either through callbacks or work. | |
1490 | */ | |
1491 | if (psock->ready_rx_msg) { | |
1492 | list_del(&psock->psock_ready_list); | |
1493 | kfree_skb(psock->ready_rx_msg); | |
1494 | psock->ready_rx_msg = NULL; | |
cd6e111b | 1495 | KCM_STATS_INCR(mux->stats.rx_ready_drops); |
ab7ac4eb TH |
1496 | } |
1497 | ||
1498 | spin_unlock_bh(&mux->rx_lock); | |
1499 | ||
1500 | write_unlock_bh(&csk->sk_callback_lock); | |
1501 | ||
1616b38f TH |
1502 | /* Call strp_done without sock lock */ |
1503 | release_sock(csk); | |
9b73896a | 1504 | strp_done(&psock->strp); |
1616b38f | 1505 | lock_sock(csk); |
ab7ac4eb TH |
1506 | |
1507 | bpf_prog_put(psock->bpf_prog); | |
1508 | ||
ab7ac4eb TH |
1509 | spin_lock_bh(&mux->lock); |
1510 | ||
cd6e111b | 1511 | aggregate_psock_stats(&psock->stats, &mux->aggregate_psock_stats); |
9b73896a | 1512 | save_strp_stats(&psock->strp, &mux->aggregate_strp_stats); |
cd6e111b TH |
1513 | |
1514 | KCM_STATS_INCR(mux->stats.psock_unattach); | |
1515 | ||
ab7ac4eb TH |
1516 | if (psock->tx_kcm) { |
1517 | /* psock was reserved. Just mark it finished and we will clean | |
1518 | * up in the kcm paths, we need kcm lock which can not be | |
1519 | * acquired here. | |
1520 | */ | |
cd6e111b | 1521 | KCM_STATS_INCR(mux->stats.psock_unattach_rsvd); |
ab7ac4eb TH |
1522 | spin_unlock_bh(&mux->lock); |
1523 | ||
1524 | /* We are unattaching a socket that is reserved. Abort the | |
1525 | * socket since we may be out of sync in sending on it. We need | |
1526 | * to do this without the mux lock. | |
1527 | */ | |
1528 | kcm_abort_tx_psock(psock, EPIPE, false); | |
1529 | ||
1530 | spin_lock_bh(&mux->lock); | |
1531 | if (!psock->tx_kcm) { | |
1532 | /* psock now unreserved in window mux was unlocked */ | |
1533 | goto no_reserved; | |
1534 | } | |
1535 | psock->done = 1; | |
1536 | ||
1537 | /* Commit done before queuing work to process it */ | |
1538 | smp_mb(); | |
1539 | ||
1540 | /* Queue tx work to make sure psock->done is handled */ | |
1541 | queue_work(kcm_wq, &psock->tx_kcm->tx_work); | |
1542 | spin_unlock_bh(&mux->lock); | |
1543 | } else { | |
1544 | no_reserved: | |
1545 | if (!psock->tx_stopped) | |
1546 | list_del(&psock->psock_avail_list); | |
1547 | list_del(&psock->psock_list); | |
1548 | mux->psocks_cnt--; | |
1549 | spin_unlock_bh(&mux->lock); | |
1550 | ||
1551 | sock_put(csk); | |
1552 | fput(csk->sk_socket->file); | |
1553 | kmem_cache_free(kcm_psockp, psock); | |
1554 | } | |
1616b38f TH |
1555 | |
1556 | release_sock(csk); | |
ab7ac4eb TH |
1557 | } |
1558 | ||
1559 | static int kcm_unattach_ioctl(struct socket *sock, struct kcm_unattach *info) | |
1560 | { | |
1561 | struct kcm_sock *kcm = kcm_sk(sock->sk); | |
1562 | struct kcm_mux *mux = kcm->mux; | |
1563 | struct kcm_psock *psock; | |
1564 | struct socket *csock; | |
1565 | struct sock *csk; | |
1566 | int err; | |
1567 | ||
1568 | csock = sockfd_lookup(info->fd, &err); | |
1569 | if (!csock) | |
1570 | return -ENOENT; | |
1571 | ||
1572 | csk = csock->sk; | |
1573 | if (!csk) { | |
1574 | err = -EINVAL; | |
1575 | goto out; | |
1576 | } | |
1577 | ||
1578 | err = -ENOENT; | |
1579 | ||
1580 | spin_lock_bh(&mux->lock); | |
1581 | ||
1582 | list_for_each_entry(psock, &mux->psocks, psock_list) { | |
1583 | if (psock->sk != csk) | |
1584 | continue; | |
1585 | ||
1586 | /* Found the matching psock */ | |
1587 | ||
1588 | if (psock->unattaching || WARN_ON(psock->done)) { | |
1589 | err = -EALREADY; | |
1590 | break; | |
1591 | } | |
1592 | ||
1593 | psock->unattaching = 1; | |
1594 | ||
1595 | spin_unlock_bh(&mux->lock); | |
1596 | ||
9b73896a | 1597 | /* Lower socket lock should already be held */ |
ab7ac4eb TH |
1598 | kcm_unattach(psock); |
1599 | ||
1600 | err = 0; | |
1601 | goto out; | |
1602 | } | |
1603 | ||
1604 | spin_unlock_bh(&mux->lock); | |
1605 | ||
1606 | out: | |
8dc879a1 | 1607 | sockfd_put(csock); |
ab7ac4eb TH |
1608 | return err; |
1609 | } | |
1610 | ||
1611 | static struct proto kcm_proto = { | |
1612 | .name = "KCM", | |
1613 | .owner = THIS_MODULE, | |
1614 | .obj_size = sizeof(struct kcm_sock), | |
1615 | }; | |
1616 | ||
1617 | /* Clone a kcm socket. */ | |
a5739435 | 1618 | static struct file *kcm_clone(struct socket *osock) |
ab7ac4eb TH |
1619 | { |
1620 | struct socket *newsock; | |
1621 | struct sock *newsk; | |
ab7ac4eb | 1622 | |
ab7ac4eb TH |
1623 | newsock = sock_alloc(); |
1624 | if (!newsock) | |
a5739435 | 1625 | return ERR_PTR(-ENFILE); |
ab7ac4eb TH |
1626 | |
1627 | newsock->type = osock->type; | |
1628 | newsock->ops = osock->ops; | |
1629 | ||
1630 | __module_get(newsock->ops->owner); | |
1631 | ||
ab7ac4eb | 1632 | newsk = sk_alloc(sock_net(osock->sk), PF_KCM, GFP_KERNEL, |
eb7f54b9 | 1633 | &kcm_proto, false); |
ab7ac4eb | 1634 | if (!newsk) { |
a5739435 AV |
1635 | sock_release(newsock); |
1636 | return ERR_PTR(-ENOMEM); | |
ab7ac4eb | 1637 | } |
ab7ac4eb TH |
1638 | sock_init_data(newsock, newsk); |
1639 | init_kcm_sock(kcm_sk(newsk), kcm_sk(osock->sk)->mux); | |
1640 | ||
8e1611e2 | 1641 | return sock_alloc_file(newsock, 0, osock->sk->sk_prot_creator->name); |
ab7ac4eb TH |
1642 | } |
1643 | ||
1644 | static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) | |
1645 | { | |
1646 | int err; | |
1647 | ||
1648 | switch (cmd) { | |
1649 | case SIOCKCMATTACH: { | |
1650 | struct kcm_attach info; | |
1651 | ||
1652 | if (copy_from_user(&info, (void __user *)arg, sizeof(info))) | |
a80db69e | 1653 | return -EFAULT; |
ab7ac4eb TH |
1654 | |
1655 | err = kcm_attach_ioctl(sock, &info); | |
1656 | ||
1657 | break; | |
1658 | } | |
1659 | case SIOCKCMUNATTACH: { | |
1660 | struct kcm_unattach info; | |
1661 | ||
1662 | if (copy_from_user(&info, (void __user *)arg, sizeof(info))) | |
a80db69e | 1663 | return -EFAULT; |
ab7ac4eb TH |
1664 | |
1665 | err = kcm_unattach_ioctl(sock, &info); | |
1666 | ||
1667 | break; | |
1668 | } | |
1669 | case SIOCKCMCLONE: { | |
1670 | struct kcm_clone info; | |
a5739435 AV |
1671 | struct file *file; |
1672 | ||
1673 | info.fd = get_unused_fd_flags(0); | |
1674 | if (unlikely(info.fd < 0)) | |
1675 | return info.fd; | |
ab7ac4eb | 1676 | |
a5739435 AV |
1677 | file = kcm_clone(sock); |
1678 | if (IS_ERR(file)) { | |
1679 | put_unused_fd(info.fd); | |
1680 | return PTR_ERR(file); | |
1681 | } | |
1682 | if (copy_to_user((void __user *)arg, &info, | |
1683 | sizeof(info))) { | |
1684 | put_unused_fd(info.fd); | |
1685 | fput(file); | |
1686 | return -EFAULT; | |
1687 | } | |
1688 | fd_install(info.fd, file); | |
1689 | err = 0; | |
ab7ac4eb TH |
1690 | break; |
1691 | } | |
1692 | default: | |
1693 | err = -ENOIOCTLCMD; | |
1694 | break; | |
1695 | } | |
1696 | ||
1697 | return err; | |
1698 | } | |
1699 | ||
1700 | static void free_mux(struct rcu_head *rcu) | |
1701 | { | |
1702 | struct kcm_mux *mux = container_of(rcu, | |
1703 | struct kcm_mux, rcu); | |
1704 | ||
1705 | kmem_cache_free(kcm_muxp, mux); | |
1706 | } | |
1707 | ||
1708 | static void release_mux(struct kcm_mux *mux) | |
1709 | { | |
1710 | struct kcm_net *knet = mux->knet; | |
1711 | struct kcm_psock *psock, *tmp_psock; | |
1712 | ||
1713 | /* Release psocks */ | |
1714 | list_for_each_entry_safe(psock, tmp_psock, | |
1715 | &mux->psocks, psock_list) { | |
1616b38f | 1716 | if (!WARN_ON(psock->unattaching)) |
ab7ac4eb TH |
1717 | kcm_unattach(psock); |
1718 | } | |
1719 | ||
1720 | if (WARN_ON(mux->psocks_cnt)) | |
1721 | return; | |
1722 | ||
1723 | __skb_queue_purge(&mux->rx_hold_queue); | |
1724 | ||
1725 | mutex_lock(&knet->mutex); | |
cd6e111b TH |
1726 | aggregate_mux_stats(&mux->stats, &knet->aggregate_mux_stats); |
1727 | aggregate_psock_stats(&mux->aggregate_psock_stats, | |
1728 | &knet->aggregate_psock_stats); | |
9b73896a TH |
1729 | aggregate_strp_stats(&mux->aggregate_strp_stats, |
1730 | &knet->aggregate_strp_stats); | |
ab7ac4eb TH |
1731 | list_del_rcu(&mux->kcm_mux_list); |
1732 | knet->count--; | |
1733 | mutex_unlock(&knet->mutex); | |
1734 | ||
1735 | call_rcu(&mux->rcu, free_mux); | |
1736 | } | |
1737 | ||
1738 | static void kcm_done(struct kcm_sock *kcm) | |
1739 | { | |
1740 | struct kcm_mux *mux = kcm->mux; | |
1741 | struct sock *sk = &kcm->sk; | |
1742 | int socks_cnt; | |
1743 | ||
1744 | spin_lock_bh(&mux->rx_lock); | |
1745 | if (kcm->rx_psock) { | |
1746 | /* Cleanup in unreserve_rx_kcm */ | |
1747 | WARN_ON(kcm->done); | |
1748 | kcm->rx_disabled = 1; | |
1749 | kcm->done = 1; | |
1750 | spin_unlock_bh(&mux->rx_lock); | |
1751 | return; | |
1752 | } | |
1753 | ||
1754 | if (kcm->rx_wait) { | |
1755 | list_del(&kcm->wait_rx_list); | |
0c745b51 ED |
1756 | /* paired with lockless reads in kcm_rfree() */ |
1757 | WRITE_ONCE(kcm->rx_wait, false); | |
ab7ac4eb TH |
1758 | } |
1759 | /* Move any pending receive messages to other kcm sockets */ | |
1760 | requeue_rx_msgs(mux, &sk->sk_receive_queue); | |
1761 | ||
1762 | spin_unlock_bh(&mux->rx_lock); | |
1763 | ||
1764 | if (WARN_ON(sk_rmem_alloc_get(sk))) | |
1765 | return; | |
1766 | ||
1767 | /* Detach from MUX */ | |
1768 | spin_lock_bh(&mux->lock); | |
1769 | ||
1770 | list_del(&kcm->kcm_sock_list); | |
1771 | mux->kcm_socks_cnt--; | |
1772 | socks_cnt = mux->kcm_socks_cnt; | |
1773 | ||
1774 | spin_unlock_bh(&mux->lock); | |
1775 | ||
1776 | if (!socks_cnt) { | |
1777 | /* We are done with the mux now. */ | |
1778 | release_mux(mux); | |
1779 | } | |
1780 | ||
1781 | WARN_ON(kcm->rx_wait); | |
1782 | ||
1783 | sock_put(&kcm->sk); | |
1784 | } | |
1785 | ||
1786 | /* Called by kcm_release to close a KCM socket. | |
1787 | * If this is the last KCM socket on the MUX, destroy the MUX. | |
1788 | */ | |
1789 | static int kcm_release(struct socket *sock) | |
1790 | { | |
1791 | struct sock *sk = sock->sk; | |
1792 | struct kcm_sock *kcm; | |
1793 | struct kcm_mux *mux; | |
1794 | struct kcm_psock *psock; | |
1795 | ||
1796 | if (!sk) | |
1797 | return 0; | |
1798 | ||
1799 | kcm = kcm_sk(sk); | |
1800 | mux = kcm->mux; | |
1801 | ||
ec7eede3 | 1802 | lock_sock(sk); |
ab7ac4eb TH |
1803 | sock_orphan(sk); |
1804 | kfree_skb(kcm->seq_skb); | |
1805 | ||
ab7ac4eb TH |
1806 | /* Purge queue under lock to avoid race condition with tx_work trying |
1807 | * to act when queue is nonempty. If tx_work runs after this point | |
1808 | * it will just return. | |
1809 | */ | |
1810 | __skb_queue_purge(&sk->sk_write_queue); | |
9b73896a TH |
1811 | |
1812 | /* Set tx_stopped. This is checked when psock is bound to a kcm and we | |
1813 | * get a writespace callback. This prevents further work being queued | |
1814 | * from the callback (unbinding the psock occurs after canceling work. | |
1815 | */ | |
1816 | kcm->tx_stopped = 1; | |
1817 | ||
ab7ac4eb TH |
1818 | release_sock(sk); |
1819 | ||
1820 | spin_lock_bh(&mux->lock); | |
1821 | if (kcm->tx_wait) { | |
1822 | /* Take of tx_wait list, after this point there should be no way | |
1823 | * that a psock will be assigned to this kcm. | |
1824 | */ | |
1825 | list_del(&kcm->wait_psock_list); | |
1826 | kcm->tx_wait = false; | |
1827 | } | |
1828 | spin_unlock_bh(&mux->lock); | |
1829 | ||
1830 | /* Cancel work. After this point there should be no outside references | |
1831 | * to the kcm socket. | |
1832 | */ | |
1833 | cancel_work_sync(&kcm->tx_work); | |
1834 | ||
1835 | lock_sock(sk); | |
1836 | psock = kcm->tx_psock; | |
1837 | if (psock) { | |
1838 | /* A psock was reserved, so we need to kill it since it | |
1839 | * may already have some bytes queued from a message. We | |
1840 | * need to do this after removing kcm from tx_wait list. | |
1841 | */ | |
1842 | kcm_abort_tx_psock(psock, EPIPE, false); | |
1843 | unreserve_psock(kcm); | |
1844 | } | |
1845 | release_sock(sk); | |
1846 | ||
1847 | WARN_ON(kcm->tx_wait); | |
1848 | WARN_ON(kcm->tx_psock); | |
1849 | ||
1850 | sock->sk = NULL; | |
1851 | ||
1852 | kcm_done(kcm); | |
1853 | ||
1854 | return 0; | |
1855 | } | |
1856 | ||
91687355 | 1857 | static const struct proto_ops kcm_dgram_ops = { |
ab7ac4eb TH |
1858 | .family = PF_KCM, |
1859 | .owner = THIS_MODULE, | |
1860 | .release = kcm_release, | |
1861 | .bind = sock_no_bind, | |
1862 | .connect = sock_no_connect, | |
1863 | .socketpair = sock_no_socketpair, | |
1864 | .accept = sock_no_accept, | |
1865 | .getname = sock_no_getname, | |
a11e1d43 | 1866 | .poll = datagram_poll, |
ab7ac4eb TH |
1867 | .ioctl = kcm_ioctl, |
1868 | .listen = sock_no_listen, | |
1869 | .shutdown = sock_no_shutdown, | |
1870 | .setsockopt = kcm_setsockopt, | |
1871 | .getsockopt = kcm_getsockopt, | |
1872 | .sendmsg = kcm_sendmsg, | |
1873 | .recvmsg = kcm_recvmsg, | |
1874 | .mmap = sock_no_mmap, | |
f29698fc | 1875 | .sendpage = kcm_sendpage, |
ab7ac4eb TH |
1876 | }; |
1877 | ||
91687355 TH |
1878 | static const struct proto_ops kcm_seqpacket_ops = { |
1879 | .family = PF_KCM, | |
1880 | .owner = THIS_MODULE, | |
1881 | .release = kcm_release, | |
1882 | .bind = sock_no_bind, | |
1883 | .connect = sock_no_connect, | |
1884 | .socketpair = sock_no_socketpair, | |
1885 | .accept = sock_no_accept, | |
1886 | .getname = sock_no_getname, | |
a11e1d43 | 1887 | .poll = datagram_poll, |
91687355 TH |
1888 | .ioctl = kcm_ioctl, |
1889 | .listen = sock_no_listen, | |
1890 | .shutdown = sock_no_shutdown, | |
1891 | .setsockopt = kcm_setsockopt, | |
1892 | .getsockopt = kcm_getsockopt, | |
1893 | .sendmsg = kcm_sendmsg, | |
1894 | .recvmsg = kcm_recvmsg, | |
1895 | .mmap = sock_no_mmap, | |
f29698fc | 1896 | .sendpage = kcm_sendpage, |
91687355 TH |
1897 | .splice_read = kcm_splice_read, |
1898 | }; | |
1899 | ||
ab7ac4eb TH |
1900 | /* Create proto operation for kcm sockets */ |
1901 | static int kcm_create(struct net *net, struct socket *sock, | |
1902 | int protocol, int kern) | |
1903 | { | |
1904 | struct kcm_net *knet = net_generic(net, kcm_net_id); | |
1905 | struct sock *sk; | |
1906 | struct kcm_mux *mux; | |
1907 | ||
1908 | switch (sock->type) { | |
1909 | case SOCK_DGRAM: | |
91687355 TH |
1910 | sock->ops = &kcm_dgram_ops; |
1911 | break; | |
ab7ac4eb | 1912 | case SOCK_SEQPACKET: |
91687355 | 1913 | sock->ops = &kcm_seqpacket_ops; |
ab7ac4eb TH |
1914 | break; |
1915 | default: | |
1916 | return -ESOCKTNOSUPPORT; | |
1917 | } | |
1918 | ||
1919 | if (protocol != KCMPROTO_CONNECTED) | |
1920 | return -EPROTONOSUPPORT; | |
1921 | ||
1922 | sk = sk_alloc(net, PF_KCM, GFP_KERNEL, &kcm_proto, kern); | |
1923 | if (!sk) | |
1924 | return -ENOMEM; | |
1925 | ||
1926 | /* Allocate a kcm mux, shared between KCM sockets */ | |
1927 | mux = kmem_cache_zalloc(kcm_muxp, GFP_KERNEL); | |
1928 | if (!mux) { | |
1929 | sk_free(sk); | |
1930 | return -ENOMEM; | |
1931 | } | |
1932 | ||
1933 | spin_lock_init(&mux->lock); | |
1934 | spin_lock_init(&mux->rx_lock); | |
1935 | INIT_LIST_HEAD(&mux->kcm_socks); | |
1936 | INIT_LIST_HEAD(&mux->kcm_rx_waiters); | |
1937 | INIT_LIST_HEAD(&mux->kcm_tx_waiters); | |
1938 | ||
1939 | INIT_LIST_HEAD(&mux->psocks); | |
1940 | INIT_LIST_HEAD(&mux->psocks_ready); | |
1941 | INIT_LIST_HEAD(&mux->psocks_avail); | |
1942 | ||
1943 | mux->knet = knet; | |
1944 | ||
1945 | /* Add new MUX to list */ | |
1946 | mutex_lock(&knet->mutex); | |
1947 | list_add_rcu(&mux->kcm_mux_list, &knet->mux_list); | |
1948 | knet->count++; | |
1949 | mutex_unlock(&knet->mutex); | |
1950 | ||
1951 | skb_queue_head_init(&mux->rx_hold_queue); | |
1952 | ||
1953 | /* Init KCM socket */ | |
1954 | sock_init_data(sock, sk); | |
1955 | init_kcm_sock(kcm_sk(sk), mux); | |
1956 | ||
1957 | return 0; | |
1958 | } | |
1959 | ||
173e7837 | 1960 | static const struct net_proto_family kcm_family_ops = { |
ab7ac4eb TH |
1961 | .family = PF_KCM, |
1962 | .create = kcm_create, | |
1963 | .owner = THIS_MODULE, | |
1964 | }; | |
1965 | ||
1966 | static __net_init int kcm_init_net(struct net *net) | |
1967 | { | |
1968 | struct kcm_net *knet = net_generic(net, kcm_net_id); | |
1969 | ||
1970 | INIT_LIST_HEAD_RCU(&knet->mux_list); | |
1971 | mutex_init(&knet->mutex); | |
1972 | ||
1973 | return 0; | |
1974 | } | |
1975 | ||
1976 | static __net_exit void kcm_exit_net(struct net *net) | |
1977 | { | |
1978 | struct kcm_net *knet = net_generic(net, kcm_net_id); | |
1979 | ||
1980 | /* All KCM sockets should be closed at this point, which should mean | |
1981 | * that all multiplexors and psocks have been destroyed. | |
1982 | */ | |
1983 | WARN_ON(!list_empty(&knet->mux_list)); | |
1984 | } | |
1985 | ||
1986 | static struct pernet_operations kcm_net_ops = { | |
1987 | .init = kcm_init_net, | |
1988 | .exit = kcm_exit_net, | |
1989 | .id = &kcm_net_id, | |
1990 | .size = sizeof(struct kcm_net), | |
1991 | }; | |
1992 | ||
1993 | static int __init kcm_init(void) | |
1994 | { | |
1995 | int err = -ENOMEM; | |
1996 | ||
1997 | kcm_muxp = kmem_cache_create("kcm_mux_cache", | |
1998 | sizeof(struct kcm_mux), 0, | |
c2115240 | 1999 | SLAB_HWCACHE_ALIGN, NULL); |
ab7ac4eb TH |
2000 | if (!kcm_muxp) |
2001 | goto fail; | |
2002 | ||
2003 | kcm_psockp = kmem_cache_create("kcm_psock_cache", | |
2004 | sizeof(struct kcm_psock), 0, | |
c2115240 | 2005 | SLAB_HWCACHE_ALIGN, NULL); |
ab7ac4eb TH |
2006 | if (!kcm_psockp) |
2007 | goto fail; | |
2008 | ||
2009 | kcm_wq = create_singlethread_workqueue("kkcmd"); | |
2010 | if (!kcm_wq) | |
2011 | goto fail; | |
2012 | ||
2013 | err = proto_register(&kcm_proto, 1); | |
2014 | if (err) | |
2015 | goto fail; | |
2016 | ||
ab7ac4eb TH |
2017 | err = register_pernet_device(&kcm_net_ops); |
2018 | if (err) | |
2019 | goto net_ops_fail; | |
2020 | ||
3c446e6f JS |
2021 | err = sock_register(&kcm_family_ops); |
2022 | if (err) | |
2023 | goto sock_register_fail; | |
2024 | ||
cd6e111b TH |
2025 | err = kcm_proc_init(); |
2026 | if (err) | |
2027 | goto proc_init_fail; | |
2028 | ||
ab7ac4eb TH |
2029 | return 0; |
2030 | ||
cd6e111b | 2031 | proc_init_fail: |
ab7ac4eb TH |
2032 | sock_unregister(PF_KCM); |
2033 | ||
2034 | sock_register_fail: | |
3c446e6f JS |
2035 | unregister_pernet_device(&kcm_net_ops); |
2036 | ||
2037 | net_ops_fail: | |
ab7ac4eb TH |
2038 | proto_unregister(&kcm_proto); |
2039 | ||
2040 | fail: | |
2041 | kmem_cache_destroy(kcm_muxp); | |
2042 | kmem_cache_destroy(kcm_psockp); | |
2043 | ||
2044 | if (kcm_wq) | |
2045 | destroy_workqueue(kcm_wq); | |
2046 | ||
2047 | return err; | |
2048 | } | |
2049 | ||
2050 | static void __exit kcm_exit(void) | |
2051 | { | |
cd6e111b | 2052 | kcm_proc_exit(); |
ab7ac4eb | 2053 | sock_unregister(PF_KCM); |
3c446e6f | 2054 | unregister_pernet_device(&kcm_net_ops); |
ab7ac4eb TH |
2055 | proto_unregister(&kcm_proto); |
2056 | destroy_workqueue(kcm_wq); | |
2057 | ||
2058 | kmem_cache_destroy(kcm_muxp); | |
2059 | kmem_cache_destroy(kcm_psockp); | |
2060 | } | |
2061 | ||
2062 | module_init(kcm_init); | |
2063 | module_exit(kcm_exit); | |
2064 | ||
2065 | MODULE_LICENSE("GPL"); | |
2066 | MODULE_ALIAS_NETPROTO(PF_KCM); |