blob: 309062f3debe298c1cf7666f77505f8d353d76d8 [file] [log] [blame]
Tom Herbert9b738962016-08-15 14:51:02 -07001/*
2 * Kernel Connection Multiplexor
3 *
4 * Copyright (c) 2016 Tom Herbert <tom@herbertland.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2
8 * as published by the Free Software Foundation.
9 */
10
Tom Herbertab7ac4e2016-03-07 14:11:06 -080011#include <linux/bpf.h>
12#include <linux/errno.h>
13#include <linux/errqueue.h>
14#include <linux/file.h>
15#include <linux/in.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/net.h>
19#include <linux/netdevice.h>
20#include <linux/poll.h>
21#include <linux/rculist.h>
22#include <linux/skbuff.h>
23#include <linux/socket.h>
24#include <linux/uaccess.h>
25#include <linux/workqueue.h>
WANG Congc0338af2016-08-28 21:28:26 -070026#include <linux/syscalls.h>
Ingo Molnar174cd4b2017-02-02 19:15:33 +010027#include <linux/sched/signal.h>
28
Tom Herbertab7ac4e2016-03-07 14:11:06 -080029#include <net/kcm.h>
30#include <net/netns/generic.h>
31#include <net/sock.h>
Tom Herbertab7ac4e2016-03-07 14:11:06 -080032#include <uapi/linux/kcm.h>
33
34unsigned int kcm_net_id;
35
36static struct kmem_cache *kcm_psockp __read_mostly;
37static struct kmem_cache *kcm_muxp __read_mostly;
38static struct workqueue_struct *kcm_wq;
39
40static inline struct kcm_sock *kcm_sk(const struct sock *sk)
41{
42 return (struct kcm_sock *)sk;
43}
44
45static inline struct kcm_tx_msg *kcm_tx_msg(struct sk_buff *skb)
46{
47 return (struct kcm_tx_msg *)skb->cb;
48}
49
Tom Herbertab7ac4e2016-03-07 14:11:06 -080050static void report_csk_error(struct sock *csk, int err)
51{
52 csk->sk_err = EPIPE;
53 csk->sk_error_report(csk);
54}
55
Tom Herbertab7ac4e2016-03-07 14:11:06 -080056static void kcm_abort_tx_psock(struct kcm_psock *psock, int err,
57 bool wakeup_kcm)
58{
59 struct sock *csk = psock->sk;
60 struct kcm_mux *mux = psock->mux;
61
62 /* Unrecoverable error in transmit */
63
64 spin_lock_bh(&mux->lock);
65
66 if (psock->tx_stopped) {
67 spin_unlock_bh(&mux->lock);
68 return;
69 }
70
71 psock->tx_stopped = 1;
Tom Herbertcd6e1112016-03-07 14:11:07 -080072 KCM_STATS_INCR(psock->stats.tx_aborts);
Tom Herbertab7ac4e2016-03-07 14:11:06 -080073
74 if (!psock->tx_kcm) {
75 /* Take off psocks_avail list */
76 list_del(&psock->psock_avail_list);
77 } else if (wakeup_kcm) {
78 /* In this case psock is being aborted while outside of
79 * write_msgs and psock is reserved. Schedule tx_work
80 * to handle the failure there. Need to commit tx_stopped
81 * before queuing work.
82 */
83 smp_mb();
84
85 queue_work(kcm_wq, &psock->tx_kcm->tx_work);
86 }
87
88 spin_unlock_bh(&mux->lock);
89
90 /* Report error on lower socket */
91 report_csk_error(csk, err);
92}
93
Tom Herbertcd6e1112016-03-07 14:11:07 -080094/* RX mux lock held. */
95static void kcm_update_rx_mux_stats(struct kcm_mux *mux,
96 struct kcm_psock *psock)
97{
Tom Herbert9b738962016-08-15 14:51:02 -070098 STRP_STATS_ADD(mux->stats.rx_bytes,
99 psock->strp.stats.rx_bytes -
100 psock->saved_rx_bytes);
Tom Herbertcd6e1112016-03-07 14:11:07 -0800101 mux->stats.rx_msgs +=
Tom Herbert9b738962016-08-15 14:51:02 -0700102 psock->strp.stats.rx_msgs - psock->saved_rx_msgs;
103 psock->saved_rx_msgs = psock->strp.stats.rx_msgs;
104 psock->saved_rx_bytes = psock->strp.stats.rx_bytes;
Tom Herbertcd6e1112016-03-07 14:11:07 -0800105}
106
107static void kcm_update_tx_mux_stats(struct kcm_mux *mux,
108 struct kcm_psock *psock)
109{
110 KCM_STATS_ADD(mux->stats.tx_bytes,
111 psock->stats.tx_bytes - psock->saved_tx_bytes);
112 mux->stats.tx_msgs +=
113 psock->stats.tx_msgs - psock->saved_tx_msgs;
114 psock->saved_tx_msgs = psock->stats.tx_msgs;
115 psock->saved_tx_bytes = psock->stats.tx_bytes;
116}
117
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800118static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
119
120/* KCM is ready to receive messages on its queue-- either the KCM is new or
121 * has become unblocked after being blocked on full socket buffer. Queue any
122 * pending ready messages on a psock. RX mux lock held.
123 */
124static void kcm_rcv_ready(struct kcm_sock *kcm)
125{
126 struct kcm_mux *mux = kcm->mux;
127 struct kcm_psock *psock;
128 struct sk_buff *skb;
129
130 if (unlikely(kcm->rx_wait || kcm->rx_psock || kcm->rx_disabled))
131 return;
132
133 while (unlikely((skb = __skb_dequeue(&mux->rx_hold_queue)))) {
134 if (kcm_queue_rcv_skb(&kcm->sk, skb)) {
135 /* Assuming buffer limit has been reached */
136 skb_queue_head(&mux->rx_hold_queue, skb);
137 WARN_ON(!sk_rmem_alloc_get(&kcm->sk));
138 return;
139 }
140 }
141
142 while (!list_empty(&mux->psocks_ready)) {
143 psock = list_first_entry(&mux->psocks_ready, struct kcm_psock,
144 psock_ready_list);
145
146 if (kcm_queue_rcv_skb(&kcm->sk, psock->ready_rx_msg)) {
147 /* Assuming buffer limit has been reached */
148 WARN_ON(!sk_rmem_alloc_get(&kcm->sk));
149 return;
150 }
151
152 /* Consumed the ready message on the psock. Schedule rx_work to
153 * get more messages.
154 */
155 list_del(&psock->psock_ready_list);
156 psock->ready_rx_msg = NULL;
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800157 /* Commit clearing of ready_rx_msg for queuing work */
158 smp_mb();
159
Tom Herbert9b738962016-08-15 14:51:02 -0700160 strp_unpause(&psock->strp);
161 strp_check_rcv(&psock->strp);
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800162 }
163
164 /* Buffer limit is okay now, add to ready list */
165 list_add_tail(&kcm->wait_rx_list,
166 &kcm->mux->kcm_rx_waiters);
167 kcm->rx_wait = true;
168}
169
170static void kcm_rfree(struct sk_buff *skb)
171{
172 struct sock *sk = skb->sk;
173 struct kcm_sock *kcm = kcm_sk(sk);
174 struct kcm_mux *mux = kcm->mux;
175 unsigned int len = skb->truesize;
176
177 sk_mem_uncharge(sk, len);
178 atomic_sub(len, &sk->sk_rmem_alloc);
179
180 /* For reading rx_wait and rx_psock without holding lock */
181 smp_mb__after_atomic();
182
183 if (!kcm->rx_wait && !kcm->rx_psock &&
184 sk_rmem_alloc_get(sk) < sk->sk_rcvlowat) {
185 spin_lock_bh(&mux->rx_lock);
186 kcm_rcv_ready(kcm);
187 spin_unlock_bh(&mux->rx_lock);
188 }
189}
190
191static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
192{
193 struct sk_buff_head *list = &sk->sk_receive_queue;
194
195 if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
196 return -ENOMEM;
197
198 if (!sk_rmem_schedule(sk, skb, skb->truesize))
199 return -ENOBUFS;
200
201 skb->dev = NULL;
202
203 skb_orphan(skb);
204 skb->sk = sk;
205 skb->destructor = kcm_rfree;
206 atomic_add(skb->truesize, &sk->sk_rmem_alloc);
207 sk_mem_charge(sk, skb->truesize);
208
209 skb_queue_tail(list, skb);
210
211 if (!sock_flag(sk, SOCK_DEAD))
212 sk->sk_data_ready(sk);
213
214 return 0;
215}
216
217/* Requeue received messages for a kcm socket to other kcm sockets. This is
218 * called with a kcm socket is receive disabled.
219 * RX mux lock held.
220 */
221static void requeue_rx_msgs(struct kcm_mux *mux, struct sk_buff_head *head)
222{
223 struct sk_buff *skb;
224 struct kcm_sock *kcm;
225
226 while ((skb = __skb_dequeue(head))) {
227 /* Reset destructor to avoid calling kcm_rcv_ready */
228 skb->destructor = sock_rfree;
229 skb_orphan(skb);
230try_again:
231 if (list_empty(&mux->kcm_rx_waiters)) {
232 skb_queue_tail(&mux->rx_hold_queue, skb);
233 continue;
234 }
235
236 kcm = list_first_entry(&mux->kcm_rx_waiters,
237 struct kcm_sock, wait_rx_list);
238
239 if (kcm_queue_rcv_skb(&kcm->sk, skb)) {
240 /* Should mean socket buffer full */
241 list_del(&kcm->wait_rx_list);
242 kcm->rx_wait = false;
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 */
253static 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
Tom Herbertcd6e1112016-03-07 14:11:07 -0800271 kcm_update_rx_mux_stats(mux, psock);
272
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800273 if (list_empty(&mux->kcm_rx_waiters)) {
274 psock->ready_rx_msg = head;
Tom Herbert9b738962016-08-15 14:51:02 -0700275 strp_pause(&psock->strp);
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800276 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);
285 kcm->rx_wait = false;
286
287 psock->rx_kcm = kcm;
288 kcm->rx_psock = psock;
289
290 spin_unlock_bh(&mux->rx_lock);
291
292 return kcm;
293}
294
295static void kcm_done(struct kcm_sock *kcm);
296
297static void kcm_done_work(struct work_struct *w)
298{
299 kcm_done(container_of(w, struct kcm_sock, done_work));
300}
301
302/* Lower sock held */
303static void unreserve_rx_kcm(struct kcm_psock *psock,
304 bool rcv_ready)
305{
306 struct kcm_sock *kcm = psock->rx_kcm;
307 struct kcm_mux *mux = psock->mux;
308
309 if (!kcm)
310 return;
311
312 spin_lock_bh(&mux->rx_lock);
313
314 psock->rx_kcm = NULL;
315 kcm->rx_psock = NULL;
316
317 /* Commit kcm->rx_psock before sk_rmem_alloc_get to sync with
318 * kcm_rfree
319 */
320 smp_mb();
321
322 if (unlikely(kcm->done)) {
323 spin_unlock_bh(&mux->rx_lock);
324
325 /* Need to run kcm_done in a task since we need to qcquire
326 * callback locks which may already be held here.
327 */
328 INIT_WORK(&kcm->done_work, kcm_done_work);
329 schedule_work(&kcm->done_work);
330 return;
331 }
332
333 if (unlikely(kcm->rx_disabled)) {
334 requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue);
335 } else if (rcv_ready || unlikely(!sk_rmem_alloc_get(&kcm->sk))) {
336 /* Check for degenerative race with rx_wait that all
337 * data was dequeued (accounted for in kcm_rfree).
338 */
339 kcm_rcv_ready(kcm);
340 }
341 spin_unlock_bh(&mux->rx_lock);
342}
343
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800344/* Lower sock lock held */
Tom Herbert96a59082016-08-28 14:43:19 -0700345static void psock_data_ready(struct sock *sk)
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800346{
347 struct kcm_psock *psock;
348
349 read_lock_bh(&sk->sk_callback_lock);
350
351 psock = (struct kcm_psock *)sk->sk_user_data;
Tom Herbert9b738962016-08-15 14:51:02 -0700352 if (likely(psock))
Tom Herbert96a59082016-08-28 14:43:19 -0700353 strp_data_ready(&psock->strp);
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800354
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800355 read_unlock_bh(&sk->sk_callback_lock);
356}
357
Tom Herbert9b738962016-08-15 14:51:02 -0700358/* Called with lower sock held */
359static void kcm_rcv_strparser(struct strparser *strp, struct sk_buff *skb)
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800360{
Tom Herbert9b738962016-08-15 14:51:02 -0700361 struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp);
362 struct kcm_sock *kcm;
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800363
Tom Herbert9b738962016-08-15 14:51:02 -0700364try_queue:
365 kcm = reserve_rx_kcm(psock, skb);
366 if (!kcm) {
367 /* Unable to reserve a KCM, message is held in psock and strp
368 * is paused.
369 */
370 return;
371 }
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800372
Tom Herbert9b738962016-08-15 14:51:02 -0700373 if (kcm_queue_rcv_skb(&kcm->sk, skb)) {
374 /* Should mean socket buffer full */
375 unreserve_rx_kcm(psock, false);
376 goto try_queue;
377 }
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800378}
379
Tom Herbert9b738962016-08-15 14:51:02 -0700380static int kcm_parse_func_strparser(struct strparser *strp, struct sk_buff *skb)
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800381{
Tom Herbert9b738962016-08-15 14:51:02 -0700382 struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp);
383 struct bpf_prog *prog = psock->bpf_prog;
384
385 return (*prog->bpf_func)(skb, prog->insnsi);
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800386}
387
Tom Herbert9b738962016-08-15 14:51:02 -0700388static int kcm_read_sock_done(struct strparser *strp, int err)
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800389{
Tom Herbert9b738962016-08-15 14:51:02 -0700390 struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp);
391
392 unreserve_rx_kcm(psock, true);
393
394 return err;
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800395}
396
Tom Herbert96a59082016-08-28 14:43:19 -0700397static void psock_state_change(struct sock *sk)
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800398{
399 /* TCP only does a POLLIN for a half close. Do a POLLHUP here
400 * since application will normally not poll with POLLIN
401 * on the TCP sockets.
402 */
403
404 report_csk_error(sk, EPIPE);
405}
406
Tom Herbert96a59082016-08-28 14:43:19 -0700407static void psock_write_space(struct sock *sk)
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800408{
409 struct kcm_psock *psock;
410 struct kcm_mux *mux;
411 struct kcm_sock *kcm;
412
413 read_lock_bh(&sk->sk_callback_lock);
414
415 psock = (struct kcm_psock *)sk->sk_user_data;
416 if (unlikely(!psock))
417 goto out;
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800418 mux = psock->mux;
419
420 spin_lock_bh(&mux->lock);
421
422 /* Check if the socket is reserved so someone is waiting for sending. */
423 kcm = psock->tx_kcm;
Tom Herbert9b738962016-08-15 14:51:02 -0700424 if (kcm && !unlikely(kcm->tx_stopped))
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800425 queue_work(kcm_wq, &kcm->tx_work);
426
427 spin_unlock_bh(&mux->lock);
428out:
429 read_unlock_bh(&sk->sk_callback_lock);
430}
431
432static void unreserve_psock(struct kcm_sock *kcm);
433
434/* kcm sock is locked. */
435static struct kcm_psock *reserve_psock(struct kcm_sock *kcm)
436{
437 struct kcm_mux *mux = kcm->mux;
438 struct kcm_psock *psock;
439
440 psock = kcm->tx_psock;
441
442 smp_rmb(); /* Must read tx_psock before tx_wait */
443
444 if (psock) {
445 WARN_ON(kcm->tx_wait);
446 if (unlikely(psock->tx_stopped))
447 unreserve_psock(kcm);
448 else
449 return kcm->tx_psock;
450 }
451
452 spin_lock_bh(&mux->lock);
453
454 /* Check again under lock to see if psock was reserved for this
455 * psock via psock_unreserve.
456 */
457 psock = kcm->tx_psock;
458 if (unlikely(psock)) {
459 WARN_ON(kcm->tx_wait);
460 spin_unlock_bh(&mux->lock);
461 return kcm->tx_psock;
462 }
463
464 if (!list_empty(&mux->psocks_avail)) {
465 psock = list_first_entry(&mux->psocks_avail,
466 struct kcm_psock,
467 psock_avail_list);
468 list_del(&psock->psock_avail_list);
469 if (kcm->tx_wait) {
470 list_del(&kcm->wait_psock_list);
471 kcm->tx_wait = false;
472 }
473 kcm->tx_psock = psock;
474 psock->tx_kcm = kcm;
Tom Herbertcd6e1112016-03-07 14:11:07 -0800475 KCM_STATS_INCR(psock->stats.reserved);
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800476 } else if (!kcm->tx_wait) {
477 list_add_tail(&kcm->wait_psock_list,
478 &mux->kcm_tx_waiters);
479 kcm->tx_wait = true;
480 }
481
482 spin_unlock_bh(&mux->lock);
483
484 return psock;
485}
486
487/* mux lock held */
488static void psock_now_avail(struct kcm_psock *psock)
489{
490 struct kcm_mux *mux = psock->mux;
491 struct kcm_sock *kcm;
492
493 if (list_empty(&mux->kcm_tx_waiters)) {
494 list_add_tail(&psock->psock_avail_list,
495 &mux->psocks_avail);
496 } else {
497 kcm = list_first_entry(&mux->kcm_tx_waiters,
498 struct kcm_sock,
499 wait_psock_list);
500 list_del(&kcm->wait_psock_list);
501 kcm->tx_wait = false;
502 psock->tx_kcm = kcm;
503
504 /* Commit before changing tx_psock since that is read in
505 * reserve_psock before queuing work.
506 */
507 smp_mb();
508
509 kcm->tx_psock = psock;
Tom Herbertcd6e1112016-03-07 14:11:07 -0800510 KCM_STATS_INCR(psock->stats.reserved);
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800511 queue_work(kcm_wq, &kcm->tx_work);
512 }
513}
514
515/* kcm sock is locked. */
516static void unreserve_psock(struct kcm_sock *kcm)
517{
518 struct kcm_psock *psock;
519 struct kcm_mux *mux = kcm->mux;
520
521 spin_lock_bh(&mux->lock);
522
523 psock = kcm->tx_psock;
524
525 if (WARN_ON(!psock)) {
526 spin_unlock_bh(&mux->lock);
527 return;
528 }
529
530 smp_rmb(); /* Read tx_psock before tx_wait */
531
Tom Herbertcd6e1112016-03-07 14:11:07 -0800532 kcm_update_tx_mux_stats(mux, psock);
533
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800534 WARN_ON(kcm->tx_wait);
535
536 kcm->tx_psock = NULL;
537 psock->tx_kcm = NULL;
Tom Herbertcd6e1112016-03-07 14:11:07 -0800538 KCM_STATS_INCR(psock->stats.unreserved);
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800539
540 if (unlikely(psock->tx_stopped)) {
541 if (psock->done) {
542 /* Deferred free */
543 list_del(&psock->psock_list);
544 mux->psocks_cnt--;
545 sock_put(psock->sk);
546 fput(psock->sk->sk_socket->file);
547 kmem_cache_free(kcm_psockp, psock);
548 }
549
550 /* Don't put back on available list */
551
552 spin_unlock_bh(&mux->lock);
553
554 return;
555 }
556
557 psock_now_avail(psock);
558
559 spin_unlock_bh(&mux->lock);
560}
561
Tom Herbertcd6e1112016-03-07 14:11:07 -0800562static void kcm_report_tx_retry(struct kcm_sock *kcm)
563{
564 struct kcm_mux *mux = kcm->mux;
565
566 spin_lock_bh(&mux->lock);
567 KCM_STATS_INCR(mux->stats.tx_retries);
568 spin_unlock_bh(&mux->lock);
569}
570
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800571/* Write any messages ready on the kcm socket. Called with kcm sock lock
572 * held. Return bytes actually sent or error.
573 */
574static int kcm_write_msgs(struct kcm_sock *kcm)
575{
576 struct sock *sk = &kcm->sk;
577 struct kcm_psock *psock;
578 struct sk_buff *skb, *head;
579 struct kcm_tx_msg *txm;
580 unsigned short fragidx, frag_offset;
581 unsigned int sent, total_sent = 0;
582 int ret = 0;
583
584 kcm->tx_wait_more = false;
585 psock = kcm->tx_psock;
586 if (unlikely(psock && psock->tx_stopped)) {
587 /* A reserved psock was aborted asynchronously. Unreserve
588 * it and we'll retry the message.
589 */
590 unreserve_psock(kcm);
Tom Herbertcd6e1112016-03-07 14:11:07 -0800591 kcm_report_tx_retry(kcm);
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800592 if (skb_queue_empty(&sk->sk_write_queue))
593 return 0;
594
595 kcm_tx_msg(skb_peek(&sk->sk_write_queue))->sent = 0;
596
597 } else if (skb_queue_empty(&sk->sk_write_queue)) {
598 return 0;
599 }
600
601 head = skb_peek(&sk->sk_write_queue);
602 txm = kcm_tx_msg(head);
603
604 if (txm->sent) {
605 /* Send of first skbuff in queue already in progress */
606 if (WARN_ON(!psock)) {
607 ret = -EINVAL;
608 goto out;
609 }
610 sent = txm->sent;
611 frag_offset = txm->frag_offset;
612 fragidx = txm->fragidx;
613 skb = txm->frag_skb;
614
615 goto do_frag;
616 }
617
618try_again:
619 psock = reserve_psock(kcm);
620 if (!psock)
621 goto out;
622
623 do {
624 skb = head;
625 txm = kcm_tx_msg(head);
626 sent = 0;
627
628do_frag_list:
629 if (WARN_ON(!skb_shinfo(skb)->nr_frags)) {
630 ret = -EINVAL;
631 goto out;
632 }
633
634 for (fragidx = 0; fragidx < skb_shinfo(skb)->nr_frags;
635 fragidx++) {
636 skb_frag_t *frag;
637
638 frag_offset = 0;
639do_frag:
640 frag = &skb_shinfo(skb)->frags[fragidx];
641 if (WARN_ON(!frag->size)) {
642 ret = -EINVAL;
643 goto out;
644 }
645
646 ret = kernel_sendpage(psock->sk->sk_socket,
647 frag->page.p,
648 frag->page_offset + frag_offset,
649 frag->size - frag_offset,
650 MSG_DONTWAIT);
651 if (ret <= 0) {
652 if (ret == -EAGAIN) {
653 /* Save state to try again when there's
654 * write space on the socket
655 */
656 txm->sent = sent;
657 txm->frag_offset = frag_offset;
658 txm->fragidx = fragidx;
659 txm->frag_skb = skb;
660
661 ret = 0;
662 goto out;
663 }
664
665 /* Hard failure in sending message, abort this
666 * psock since it has lost framing
667 * synchonization and retry sending the
668 * message from the beginning.
669 */
670 kcm_abort_tx_psock(psock, ret ? -ret : EPIPE,
671 true);
672 unreserve_psock(kcm);
673
674 txm->sent = 0;
Tom Herbertcd6e1112016-03-07 14:11:07 -0800675 kcm_report_tx_retry(kcm);
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800676 ret = 0;
677
678 goto try_again;
679 }
680
681 sent += ret;
682 frag_offset += ret;
Tom Herbertcd6e1112016-03-07 14:11:07 -0800683 KCM_STATS_ADD(psock->stats.tx_bytes, ret);
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800684 if (frag_offset < frag->size) {
685 /* Not finished with this frag */
686 goto do_frag;
687 }
688 }
689
690 if (skb == head) {
691 if (skb_has_frag_list(skb)) {
692 skb = skb_shinfo(skb)->frag_list;
693 goto do_frag_list;
694 }
695 } else if (skb->next) {
696 skb = skb->next;
697 goto do_frag_list;
698 }
699
700 /* Successfully sent the whole packet, account for it. */
701 skb_dequeue(&sk->sk_write_queue);
702 kfree_skb(head);
703 sk->sk_wmem_queued -= sent;
704 total_sent += sent;
Tom Herbertcd6e1112016-03-07 14:11:07 -0800705 KCM_STATS_INCR(psock->stats.tx_msgs);
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800706 } while ((head = skb_peek(&sk->sk_write_queue)));
707out:
708 if (!head) {
709 /* Done with all queued messages. */
710 WARN_ON(!skb_queue_empty(&sk->sk_write_queue));
711 unreserve_psock(kcm);
712 }
713
714 /* Check if write space is available */
715 sk->sk_write_space(sk);
716
717 return total_sent ? : ret;
718}
719
720static void kcm_tx_work(struct work_struct *w)
721{
722 struct kcm_sock *kcm = container_of(w, struct kcm_sock, tx_work);
723 struct sock *sk = &kcm->sk;
724 int err;
725
726 lock_sock(sk);
727
728 /* Primarily for SOCK_DGRAM sockets, also handle asynchronous tx
729 * aborts
730 */
731 err = kcm_write_msgs(kcm);
732 if (err < 0) {
733 /* Hard failure in write, report error on KCM socket */
734 pr_warn("KCM: Hard failure on kcm_write_msgs %d\n", err);
735 report_csk_error(&kcm->sk, -err);
736 goto out;
737 }
738
739 /* Primarily for SOCK_SEQPACKET sockets */
740 if (likely(sk->sk_socket) &&
741 test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
742 clear_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
743 sk->sk_write_space(sk);
744 }
745
746out:
747 release_sock(sk);
748}
749
750static void kcm_push(struct kcm_sock *kcm)
751{
752 if (kcm->tx_wait_more)
753 kcm_write_msgs(kcm);
754}
755
Tom Herbertf29698fc2016-03-07 14:11:09 -0800756static ssize_t kcm_sendpage(struct socket *sock, struct page *page,
757 int offset, size_t size, int flags)
758
759{
760 struct sock *sk = sock->sk;
761 struct kcm_sock *kcm = kcm_sk(sk);
762 struct sk_buff *skb = NULL, *head = NULL;
763 long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
764 bool eor;
765 int err = 0;
766 int i;
767
768 if (flags & MSG_SENDPAGE_NOTLAST)
769 flags |= MSG_MORE;
770
771 /* No MSG_EOR from splice, only look at MSG_MORE */
772 eor = !(flags & MSG_MORE);
773
774 lock_sock(sk);
775
776 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
777
778 err = -EPIPE;
779 if (sk->sk_err)
780 goto out_error;
781
782 if (kcm->seq_skb) {
783 /* Previously opened message */
784 head = kcm->seq_skb;
785 skb = kcm_tx_msg(head)->last_skb;
786 i = skb_shinfo(skb)->nr_frags;
787
788 if (skb_can_coalesce(skb, i, page, offset)) {
789 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], size);
790 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
791 goto coalesced;
792 }
793
794 if (i >= MAX_SKB_FRAGS) {
795 struct sk_buff *tskb;
796
797 tskb = alloc_skb(0, sk->sk_allocation);
798 while (!tskb) {
799 kcm_push(kcm);
800 err = sk_stream_wait_memory(sk, &timeo);
801 if (err)
802 goto out_error;
803 }
804
805 if (head == skb)
806 skb_shinfo(head)->frag_list = tskb;
807 else
808 skb->next = tskb;
809
810 skb = tskb;
811 skb->ip_summed = CHECKSUM_UNNECESSARY;
812 i = 0;
813 }
814 } else {
815 /* Call the sk_stream functions to manage the sndbuf mem. */
816 if (!sk_stream_memory_free(sk)) {
817 kcm_push(kcm);
818 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
819 err = sk_stream_wait_memory(sk, &timeo);
820 if (err)
821 goto out_error;
822 }
823
824 head = alloc_skb(0, sk->sk_allocation);
825 while (!head) {
826 kcm_push(kcm);
827 err = sk_stream_wait_memory(sk, &timeo);
828 if (err)
829 goto out_error;
830 }
831
832 skb = head;
833 i = 0;
834 }
835
836 get_page(page);
837 skb_fill_page_desc(skb, i, page, offset, size);
838 skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
839
840coalesced:
841 skb->len += size;
842 skb->data_len += size;
843 skb->truesize += size;
844 sk->sk_wmem_queued += size;
845 sk_mem_charge(sk, size);
846
847 if (head != skb) {
848 head->len += size;
849 head->data_len += size;
850 head->truesize += size;
851 }
852
853 if (eor) {
854 bool not_busy = skb_queue_empty(&sk->sk_write_queue);
855
856 /* Message complete, queue it on send buffer */
857 __skb_queue_tail(&sk->sk_write_queue, head);
858 kcm->seq_skb = NULL;
859 KCM_STATS_INCR(kcm->stats.tx_msgs);
860
861 if (flags & MSG_BATCH) {
862 kcm->tx_wait_more = true;
863 } else if (kcm->tx_wait_more || not_busy) {
864 err = kcm_write_msgs(kcm);
865 if (err < 0) {
866 /* We got a hard error in write_msgs but have
867 * already queued this message. Report an error
868 * in the socket, but don't affect return value
869 * from sendmsg
870 */
871 pr_warn("KCM: Hard failure on kcm_write_msgs\n");
872 report_csk_error(&kcm->sk, -err);
873 }
874 }
875 } else {
876 /* Message not complete, save state */
877 kcm->seq_skb = head;
878 kcm_tx_msg(head)->last_skb = skb;
879 }
880
881 KCM_STATS_ADD(kcm->stats.tx_bytes, size);
882
883 release_sock(sk);
884 return size;
885
886out_error:
887 kcm_push(kcm);
888
889 err = sk_stream_error(sk, flags, err);
890
891 /* make sure we wake any epoll edge trigger waiter */
892 if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN))
893 sk->sk_write_space(sk);
894
895 release_sock(sk);
896 return err;
897}
898
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800899static int kcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
900{
901 struct sock *sk = sock->sk;
902 struct kcm_sock *kcm = kcm_sk(sk);
903 struct sk_buff *skb = NULL, *head = NULL;
904 size_t copy, copied = 0;
905 long timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
906 int eor = (sock->type == SOCK_DGRAM) ?
907 !(msg->msg_flags & MSG_MORE) : !!(msg->msg_flags & MSG_EOR);
908 int err = -EPIPE;
909
910 lock_sock(sk);
911
912 /* Per tcp_sendmsg this should be in poll */
913 sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
914
915 if (sk->sk_err)
916 goto out_error;
917
918 if (kcm->seq_skb) {
919 /* Previously opened message */
920 head = kcm->seq_skb;
921 skb = kcm_tx_msg(head)->last_skb;
922 goto start;
923 }
924
925 /* Call the sk_stream functions to manage the sndbuf mem. */
926 if (!sk_stream_memory_free(sk)) {
927 kcm_push(kcm);
928 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
929 err = sk_stream_wait_memory(sk, &timeo);
930 if (err)
931 goto out_error;
932 }
933
WANG Cong98e3862c2017-02-07 12:59:47 -0800934 if (msg_data_left(msg)) {
935 /* New message, alloc head skb */
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800936 head = alloc_skb(0, sk->sk_allocation);
WANG Cong98e3862c2017-02-07 12:59:47 -0800937 while (!head) {
938 kcm_push(kcm);
939 err = sk_stream_wait_memory(sk, &timeo);
940 if (err)
941 goto out_error;
942
943 head = alloc_skb(0, sk->sk_allocation);
944 }
945
946 skb = head;
947
948 /* Set ip_summed to CHECKSUM_UNNECESSARY to avoid calling
949 * csum_and_copy_from_iter from skb_do_copy_data_nocache.
950 */
951 skb->ip_summed = CHECKSUM_UNNECESSARY;
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800952 }
953
Tom Herbertab7ac4e2016-03-07 14:11:06 -0800954start:
955 while (msg_data_left(msg)) {
956 bool merge = true;
957 int i = skb_shinfo(skb)->nr_frags;
958 struct page_frag *pfrag = sk_page_frag(sk);
959
960 if (!sk_page_frag_refill(sk, pfrag))
961 goto wait_for_memory;
962
963 if (!skb_can_coalesce(skb, i, pfrag->page,
964 pfrag->offset)) {
965 if (i == MAX_SKB_FRAGS) {
966 struct sk_buff *tskb;
967
968 tskb = alloc_skb(0, sk->sk_allocation);
969 if (!tskb)
970 goto wait_for_memory;
971
972 if (head == skb)
973 skb_shinfo(head)->frag_list = tskb;
974 else
975 skb->next = tskb;
976
977 skb = tskb;
978 skb->ip_summed = CHECKSUM_UNNECESSARY;
979 continue;
980 }
981 merge = false;
982 }
983
984 copy = min_t(int, msg_data_left(msg),
985 pfrag->size - pfrag->offset);
986
987 if (!sk_wmem_schedule(sk, copy))
988 goto wait_for_memory;
989
990 err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb,
991 pfrag->page,
992 pfrag->offset,
993 copy);
994 if (err)
995 goto out_error;
996
997 /* Update the skb. */
998 if (merge) {
999 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
1000 } else {
1001 skb_fill_page_desc(skb, i, pfrag->page,
1002 pfrag->offset, copy);
1003 get_page(pfrag->page);
1004 }
1005
1006 pfrag->offset += copy;
1007 copied += copy;
1008 if (head != skb) {
1009 head->len += copy;
1010 head->data_len += copy;
1011 }
1012
1013 continue;
1014
1015wait_for_memory:
1016 kcm_push(kcm);
1017 err = sk_stream_wait_memory(sk, &timeo);
1018 if (err)
1019 goto out_error;
1020 }
1021
1022 if (eor) {
1023 bool not_busy = skb_queue_empty(&sk->sk_write_queue);
1024
WANG Cong98e3862c2017-02-07 12:59:47 -08001025 if (head) {
1026 /* Message complete, queue it on send buffer */
1027 __skb_queue_tail(&sk->sk_write_queue, head);
1028 kcm->seq_skb = NULL;
1029 KCM_STATS_INCR(kcm->stats.tx_msgs);
1030 }
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001031
1032 if (msg->msg_flags & MSG_BATCH) {
1033 kcm->tx_wait_more = true;
1034 } else if (kcm->tx_wait_more || not_busy) {
1035 err = kcm_write_msgs(kcm);
1036 if (err < 0) {
1037 /* We got a hard error in write_msgs but have
1038 * already queued this message. Report an error
1039 * in the socket, but don't affect return value
1040 * from sendmsg
1041 */
1042 pr_warn("KCM: Hard failure on kcm_write_msgs\n");
1043 report_csk_error(&kcm->sk, -err);
1044 }
1045 }
1046 } else {
1047 /* Message not complete, save state */
1048partial_message:
WANG Congcd27b962017-02-13 11:13:16 -08001049 if (head) {
1050 kcm->seq_skb = head;
1051 kcm_tx_msg(head)->last_skb = skb;
1052 }
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001053 }
1054
Tom Herbertcd6e1112016-03-07 14:11:07 -08001055 KCM_STATS_ADD(kcm->stats.tx_bytes, copied);
1056
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001057 release_sock(sk);
1058 return copied;
1059
1060out_error:
1061 kcm_push(kcm);
1062
1063 if (copied && sock->type == SOCK_SEQPACKET) {
1064 /* Wrote some bytes before encountering an
1065 * error, return partial success.
1066 */
1067 goto partial_message;
1068 }
1069
1070 if (head != kcm->seq_skb)
1071 kfree_skb(head);
1072
1073 err = sk_stream_error(sk, msg->msg_flags, err);
1074
1075 /* make sure we wake any epoll edge trigger waiter */
1076 if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 && err == -EAGAIN))
1077 sk->sk_write_space(sk);
1078
1079 release_sock(sk);
1080 return err;
1081}
1082
1083static struct sk_buff *kcm_wait_data(struct sock *sk, int flags,
1084 long timeo, int *err)
1085{
1086 struct sk_buff *skb;
1087
1088 while (!(skb = skb_peek(&sk->sk_receive_queue))) {
1089 if (sk->sk_err) {
1090 *err = sock_error(sk);
1091 return NULL;
1092 }
1093
1094 if (sock_flag(sk, SOCK_DONE))
1095 return NULL;
1096
1097 if ((flags & MSG_DONTWAIT) || !timeo) {
1098 *err = -EAGAIN;
1099 return NULL;
1100 }
1101
1102 sk_wait_data(sk, &timeo, NULL);
1103
1104 /* Handle signals */
1105 if (signal_pending(current)) {
1106 *err = sock_intr_errno(timeo);
1107 return NULL;
1108 }
1109 }
1110
1111 return skb;
1112}
1113
1114static int kcm_recvmsg(struct socket *sock, struct msghdr *msg,
1115 size_t len, int flags)
1116{
1117 struct sock *sk = sock->sk;
Tom Herbertcd6e1112016-03-07 14:11:07 -08001118 struct kcm_sock *kcm = kcm_sk(sk);
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001119 int err = 0;
1120 long timeo;
Tom Herbert9b738962016-08-15 14:51:02 -07001121 struct strp_rx_msg *rxm;
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001122 int copied = 0;
1123 struct sk_buff *skb;
1124
1125 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1126
1127 lock_sock(sk);
1128
1129 skb = kcm_wait_data(sk, flags, timeo, &err);
1130 if (!skb)
1131 goto out;
1132
1133 /* Okay, have a message on the receive queue */
1134
Tom Herbert9b738962016-08-15 14:51:02 -07001135 rxm = strp_rx_msg(skb);
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001136
1137 if (len > rxm->full_len)
1138 len = rxm->full_len;
1139
1140 err = skb_copy_datagram_msg(skb, rxm->offset, msg, len);
1141 if (err < 0)
1142 goto out;
1143
1144 copied = len;
1145 if (likely(!(flags & MSG_PEEK))) {
Tom Herbertcd6e1112016-03-07 14:11:07 -08001146 KCM_STATS_ADD(kcm->stats.rx_bytes, copied);
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001147 if (copied < rxm->full_len) {
1148 if (sock->type == SOCK_DGRAM) {
1149 /* Truncated message */
1150 msg->msg_flags |= MSG_TRUNC;
1151 goto msg_finished;
1152 }
1153 rxm->offset += copied;
1154 rxm->full_len -= copied;
1155 } else {
1156msg_finished:
1157 /* Finished with message */
1158 msg->msg_flags |= MSG_EOR;
Tom Herbertcd6e1112016-03-07 14:11:07 -08001159 KCM_STATS_INCR(kcm->stats.rx_msgs);
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001160 skb_unlink(skb, &sk->sk_receive_queue);
1161 kfree_skb(skb);
1162 }
1163 }
1164
1165out:
1166 release_sock(sk);
1167
1168 return copied ? : err;
1169}
1170
Tom Herbert91687352016-03-07 14:11:08 -08001171static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos,
1172 struct pipe_inode_info *pipe, size_t len,
1173 unsigned int flags)
1174{
1175 struct sock *sk = sock->sk;
1176 struct kcm_sock *kcm = kcm_sk(sk);
1177 long timeo;
Tom Herbert9b738962016-08-15 14:51:02 -07001178 struct strp_rx_msg *rxm;
Tom Herbert91687352016-03-07 14:11:08 -08001179 int err = 0;
WANG Congf1971a22016-05-17 14:05:49 -07001180 ssize_t copied;
Tom Herbert91687352016-03-07 14:11:08 -08001181 struct sk_buff *skb;
1182
1183 /* Only support splice for SOCKSEQPACKET */
1184
1185 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
1186
1187 lock_sock(sk);
1188
1189 skb = kcm_wait_data(sk, flags, timeo, &err);
1190 if (!skb)
1191 goto err_out;
1192
1193 /* Okay, have a message on the receive queue */
1194
Tom Herbert9b738962016-08-15 14:51:02 -07001195 rxm = strp_rx_msg(skb);
Tom Herbert91687352016-03-07 14:11:08 -08001196
1197 if (len > rxm->full_len)
1198 len = rxm->full_len;
1199
Al Viro25869262016-09-17 21:02:10 -04001200 copied = skb_splice_bits(skb, sk, rxm->offset, pipe, len, flags);
Tom Herbert91687352016-03-07 14:11:08 -08001201 if (copied < 0) {
1202 err = copied;
1203 goto err_out;
1204 }
1205
1206 KCM_STATS_ADD(kcm->stats.rx_bytes, copied);
1207
1208 rxm->offset += copied;
1209 rxm->full_len -= copied;
1210
1211 /* We have no way to return MSG_EOR. If all the bytes have been
1212 * read we still leave the message in the receive socket buffer.
1213 * A subsequent recvmsg needs to be done to return MSG_EOR and
1214 * finish reading the message.
1215 */
1216
1217 release_sock(sk);
1218
1219 return copied;
1220
1221err_out:
1222 release_sock(sk);
1223
1224 return err;
1225}
1226
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001227/* kcm sock lock held */
1228static void kcm_recv_disable(struct kcm_sock *kcm)
1229{
1230 struct kcm_mux *mux = kcm->mux;
1231
1232 if (kcm->rx_disabled)
1233 return;
1234
1235 spin_lock_bh(&mux->rx_lock);
1236
1237 kcm->rx_disabled = 1;
1238
1239 /* If a psock is reserved we'll do cleanup in unreserve */
1240 if (!kcm->rx_psock) {
1241 if (kcm->rx_wait) {
1242 list_del(&kcm->wait_rx_list);
1243 kcm->rx_wait = false;
1244 }
1245
1246 requeue_rx_msgs(mux, &kcm->sk.sk_receive_queue);
1247 }
1248
1249 spin_unlock_bh(&mux->rx_lock);
1250}
1251
1252/* kcm sock lock held */
1253static void kcm_recv_enable(struct kcm_sock *kcm)
1254{
1255 struct kcm_mux *mux = kcm->mux;
1256
1257 if (!kcm->rx_disabled)
1258 return;
1259
1260 spin_lock_bh(&mux->rx_lock);
1261
1262 kcm->rx_disabled = 0;
1263 kcm_rcv_ready(kcm);
1264
1265 spin_unlock_bh(&mux->rx_lock);
1266}
1267
1268static int kcm_setsockopt(struct socket *sock, int level, int optname,
1269 char __user *optval, unsigned int optlen)
1270{
1271 struct kcm_sock *kcm = kcm_sk(sock->sk);
1272 int val, valbool;
1273 int err = 0;
1274
1275 if (level != SOL_KCM)
1276 return -ENOPROTOOPT;
1277
1278 if (optlen < sizeof(int))
1279 return -EINVAL;
1280
1281 if (get_user(val, (int __user *)optval))
1282 return -EINVAL;
1283
1284 valbool = val ? 1 : 0;
1285
1286 switch (optname) {
1287 case KCM_RECV_DISABLE:
1288 lock_sock(&kcm->sk);
1289 if (valbool)
1290 kcm_recv_disable(kcm);
1291 else
1292 kcm_recv_enable(kcm);
1293 release_sock(&kcm->sk);
1294 break;
1295 default:
1296 err = -ENOPROTOOPT;
1297 }
1298
1299 return err;
1300}
1301
1302static int kcm_getsockopt(struct socket *sock, int level, int optname,
1303 char __user *optval, int __user *optlen)
1304{
1305 struct kcm_sock *kcm = kcm_sk(sock->sk);
1306 int val, len;
1307
1308 if (level != SOL_KCM)
1309 return -ENOPROTOOPT;
1310
1311 if (get_user(len, optlen))
1312 return -EFAULT;
1313
1314 len = min_t(unsigned int, len, sizeof(int));
1315 if (len < 0)
1316 return -EINVAL;
1317
1318 switch (optname) {
1319 case KCM_RECV_DISABLE:
1320 val = kcm->rx_disabled;
1321 break;
1322 default:
1323 return -ENOPROTOOPT;
1324 }
1325
1326 if (put_user(len, optlen))
1327 return -EFAULT;
1328 if (copy_to_user(optval, &val, len))
1329 return -EFAULT;
1330 return 0;
1331}
1332
1333static void init_kcm_sock(struct kcm_sock *kcm, struct kcm_mux *mux)
1334{
1335 struct kcm_sock *tkcm;
1336 struct list_head *head;
1337 int index = 0;
1338
1339 /* For SOCK_SEQPACKET sock type, datagram_poll checks the sk_state, so
1340 * we set sk_state, otherwise epoll_wait always returns right away with
1341 * POLLHUP
1342 */
1343 kcm->sk.sk_state = TCP_ESTABLISHED;
1344
1345 /* Add to mux's kcm sockets list */
1346 kcm->mux = mux;
1347 spin_lock_bh(&mux->lock);
1348
1349 head = &mux->kcm_socks;
1350 list_for_each_entry(tkcm, &mux->kcm_socks, kcm_sock_list) {
1351 if (tkcm->index != index)
1352 break;
1353 head = &tkcm->kcm_sock_list;
1354 index++;
1355 }
1356
1357 list_add(&kcm->kcm_sock_list, head);
1358 kcm->index = index;
1359
1360 mux->kcm_socks_cnt++;
1361 spin_unlock_bh(&mux->lock);
1362
1363 INIT_WORK(&kcm->tx_work, kcm_tx_work);
1364
1365 spin_lock_bh(&mux->rx_lock);
1366 kcm_rcv_ready(kcm);
1367 spin_unlock_bh(&mux->rx_lock);
1368}
1369
1370static int kcm_attach(struct socket *sock, struct socket *csock,
1371 struct bpf_prog *prog)
1372{
1373 struct kcm_sock *kcm = kcm_sk(sock->sk);
1374 struct kcm_mux *mux = kcm->mux;
1375 struct sock *csk;
1376 struct kcm_psock *psock = NULL, *tpsock;
1377 struct list_head *head;
1378 int index = 0;
Tom Herbert9b738962016-08-15 14:51:02 -07001379 struct strp_callbacks cb;
Tom Herbert96a59082016-08-28 14:43:19 -07001380 int err;
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001381
1382 csk = csock->sk;
1383 if (!csk)
1384 return -EINVAL;
1385
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001386 psock = kmem_cache_zalloc(kcm_psockp, GFP_KERNEL);
1387 if (!psock)
1388 return -ENOMEM;
1389
1390 psock->mux = mux;
1391 psock->sk = csk;
1392 psock->bpf_prog = prog;
Tom Herbert29152a32016-03-07 14:11:11 -08001393
Tom Herbert9b738962016-08-15 14:51:02 -07001394 cb.rcv_msg = kcm_rcv_strparser;
1395 cb.abort_parser = NULL;
1396 cb.parse_msg = kcm_parse_func_strparser;
1397 cb.read_sock_done = kcm_read_sock_done;
Tom Herbert29152a32016-03-07 14:11:11 -08001398
Tom Herbert96a59082016-08-28 14:43:19 -07001399 err = strp_init(&psock->strp, csk, &cb);
1400 if (err) {
1401 kmem_cache_free(kcm_psockp, psock);
1402 return err;
1403 }
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001404
1405 sock_hold(csk);
1406
1407 write_lock_bh(&csk->sk_callback_lock);
1408 psock->save_data_ready = csk->sk_data_ready;
1409 psock->save_write_space = csk->sk_write_space;
1410 psock->save_state_change = csk->sk_state_change;
1411 csk->sk_user_data = psock;
Tom Herbert96a59082016-08-28 14:43:19 -07001412 csk->sk_data_ready = psock_data_ready;
1413 csk->sk_write_space = psock_write_space;
1414 csk->sk_state_change = psock_state_change;
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001415 write_unlock_bh(&csk->sk_callback_lock);
1416
1417 /* Finished initialization, now add the psock to the MUX. */
1418 spin_lock_bh(&mux->lock);
1419 head = &mux->psocks;
1420 list_for_each_entry(tpsock, &mux->psocks, psock_list) {
1421 if (tpsock->index != index)
1422 break;
1423 head = &tpsock->psock_list;
1424 index++;
1425 }
1426
1427 list_add(&psock->psock_list, head);
1428 psock->index = index;
1429
Tom Herbertcd6e1112016-03-07 14:11:07 -08001430 KCM_STATS_INCR(mux->stats.psock_attach);
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001431 mux->psocks_cnt++;
1432 psock_now_avail(psock);
1433 spin_unlock_bh(&mux->lock);
1434
1435 /* Schedule RX work in case there are already bytes queued */
Tom Herbert9b738962016-08-15 14:51:02 -07001436 strp_check_rcv(&psock->strp);
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001437
1438 return 0;
1439}
1440
1441static int kcm_attach_ioctl(struct socket *sock, struct kcm_attach *info)
1442{
1443 struct socket *csock;
1444 struct bpf_prog *prog;
1445 int err;
1446
1447 csock = sockfd_lookup(info->fd, &err);
1448 if (!csock)
1449 return -ENOENT;
1450
Daniel Borkmann113214b2016-06-30 17:24:44 +02001451 prog = bpf_prog_get_type(info->bpf_fd, BPF_PROG_TYPE_SOCKET_FILTER);
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001452 if (IS_ERR(prog)) {
1453 err = PTR_ERR(prog);
1454 goto out;
1455 }
1456
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001457 err = kcm_attach(sock, csock, prog);
1458 if (err) {
1459 bpf_prog_put(prog);
1460 goto out;
1461 }
1462
1463 /* Keep reference on file also */
1464
1465 return 0;
1466out:
1467 fput(csock->file);
1468 return err;
1469}
1470
1471static void kcm_unattach(struct kcm_psock *psock)
1472{
1473 struct sock *csk = psock->sk;
1474 struct kcm_mux *mux = psock->mux;
1475
Tom Herbert1616b382016-08-23 11:55:31 -07001476 lock_sock(csk);
1477
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001478 /* Stop getting callbacks from TCP socket. After this there should
1479 * be no way to reserve a kcm for this psock.
1480 */
1481 write_lock_bh(&csk->sk_callback_lock);
1482 csk->sk_user_data = NULL;
1483 csk->sk_data_ready = psock->save_data_ready;
1484 csk->sk_write_space = psock->save_write_space;
1485 csk->sk_state_change = psock->save_state_change;
Tom Herbert9b738962016-08-15 14:51:02 -07001486 strp_stop(&psock->strp);
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001487
1488 if (WARN_ON(psock->rx_kcm)) {
1489 write_unlock_bh(&csk->sk_callback_lock);
1490 return;
1491 }
1492
1493 spin_lock_bh(&mux->rx_lock);
1494
1495 /* Stop receiver activities. After this point psock should not be
1496 * able to get onto ready list either through callbacks or work.
1497 */
1498 if (psock->ready_rx_msg) {
1499 list_del(&psock->psock_ready_list);
1500 kfree_skb(psock->ready_rx_msg);
1501 psock->ready_rx_msg = NULL;
Tom Herbertcd6e1112016-03-07 14:11:07 -08001502 KCM_STATS_INCR(mux->stats.rx_ready_drops);
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001503 }
1504
1505 spin_unlock_bh(&mux->rx_lock);
1506
1507 write_unlock_bh(&csk->sk_callback_lock);
1508
Tom Herbert1616b382016-08-23 11:55:31 -07001509 /* Call strp_done without sock lock */
1510 release_sock(csk);
Tom Herbert9b738962016-08-15 14:51:02 -07001511 strp_done(&psock->strp);
Tom Herbert1616b382016-08-23 11:55:31 -07001512 lock_sock(csk);
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001513
1514 bpf_prog_put(psock->bpf_prog);
1515
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001516 spin_lock_bh(&mux->lock);
1517
Tom Herbertcd6e1112016-03-07 14:11:07 -08001518 aggregate_psock_stats(&psock->stats, &mux->aggregate_psock_stats);
Tom Herbert9b738962016-08-15 14:51:02 -07001519 save_strp_stats(&psock->strp, &mux->aggregate_strp_stats);
Tom Herbertcd6e1112016-03-07 14:11:07 -08001520
1521 KCM_STATS_INCR(mux->stats.psock_unattach);
1522
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001523 if (psock->tx_kcm) {
1524 /* psock was reserved. Just mark it finished and we will clean
1525 * up in the kcm paths, we need kcm lock which can not be
1526 * acquired here.
1527 */
Tom Herbertcd6e1112016-03-07 14:11:07 -08001528 KCM_STATS_INCR(mux->stats.psock_unattach_rsvd);
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001529 spin_unlock_bh(&mux->lock);
1530
1531 /* We are unattaching a socket that is reserved. Abort the
1532 * socket since we may be out of sync in sending on it. We need
1533 * to do this without the mux lock.
1534 */
1535 kcm_abort_tx_psock(psock, EPIPE, false);
1536
1537 spin_lock_bh(&mux->lock);
1538 if (!psock->tx_kcm) {
1539 /* psock now unreserved in window mux was unlocked */
1540 goto no_reserved;
1541 }
1542 psock->done = 1;
1543
1544 /* Commit done before queuing work to process it */
1545 smp_mb();
1546
1547 /* Queue tx work to make sure psock->done is handled */
1548 queue_work(kcm_wq, &psock->tx_kcm->tx_work);
1549 spin_unlock_bh(&mux->lock);
1550 } else {
1551no_reserved:
1552 if (!psock->tx_stopped)
1553 list_del(&psock->psock_avail_list);
1554 list_del(&psock->psock_list);
1555 mux->psocks_cnt--;
1556 spin_unlock_bh(&mux->lock);
1557
1558 sock_put(csk);
1559 fput(csk->sk_socket->file);
1560 kmem_cache_free(kcm_psockp, psock);
1561 }
Tom Herbert1616b382016-08-23 11:55:31 -07001562
1563 release_sock(csk);
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001564}
1565
1566static int kcm_unattach_ioctl(struct socket *sock, struct kcm_unattach *info)
1567{
1568 struct kcm_sock *kcm = kcm_sk(sock->sk);
1569 struct kcm_mux *mux = kcm->mux;
1570 struct kcm_psock *psock;
1571 struct socket *csock;
1572 struct sock *csk;
1573 int err;
1574
1575 csock = sockfd_lookup(info->fd, &err);
1576 if (!csock)
1577 return -ENOENT;
1578
1579 csk = csock->sk;
1580 if (!csk) {
1581 err = -EINVAL;
1582 goto out;
1583 }
1584
1585 err = -ENOENT;
1586
1587 spin_lock_bh(&mux->lock);
1588
1589 list_for_each_entry(psock, &mux->psocks, psock_list) {
1590 if (psock->sk != csk)
1591 continue;
1592
1593 /* Found the matching psock */
1594
1595 if (psock->unattaching || WARN_ON(psock->done)) {
1596 err = -EALREADY;
1597 break;
1598 }
1599
1600 psock->unattaching = 1;
1601
1602 spin_unlock_bh(&mux->lock);
1603
Tom Herbert9b738962016-08-15 14:51:02 -07001604 /* Lower socket lock should already be held */
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001605 kcm_unattach(psock);
1606
1607 err = 0;
1608 goto out;
1609 }
1610
1611 spin_unlock_bh(&mux->lock);
1612
1613out:
1614 fput(csock->file);
1615 return err;
1616}
1617
1618static struct proto kcm_proto = {
1619 .name = "KCM",
1620 .owner = THIS_MODULE,
1621 .obj_size = sizeof(struct kcm_sock),
1622};
1623
1624/* Clone a kcm socket. */
1625static int kcm_clone(struct socket *osock, struct kcm_clone *info,
1626 struct socket **newsockp)
1627{
1628 struct socket *newsock;
1629 struct sock *newsk;
1630 struct file *newfile;
1631 int err, newfd;
1632
1633 err = -ENFILE;
1634 newsock = sock_alloc();
1635 if (!newsock)
1636 goto out;
1637
1638 newsock->type = osock->type;
1639 newsock->ops = osock->ops;
1640
1641 __module_get(newsock->ops->owner);
1642
1643 newfd = get_unused_fd_flags(0);
1644 if (unlikely(newfd < 0)) {
1645 err = newfd;
1646 goto out_fd_fail;
1647 }
1648
1649 newfile = sock_alloc_file(newsock, 0, osock->sk->sk_prot_creator->name);
1650 if (unlikely(IS_ERR(newfile))) {
1651 err = PTR_ERR(newfile);
1652 goto out_sock_alloc_fail;
1653 }
1654
1655 newsk = sk_alloc(sock_net(osock->sk), PF_KCM, GFP_KERNEL,
1656 &kcm_proto, true);
1657 if (!newsk) {
1658 err = -ENOMEM;
1659 goto out_sk_alloc_fail;
1660 }
1661
1662 sock_init_data(newsock, newsk);
1663 init_kcm_sock(kcm_sk(newsk), kcm_sk(osock->sk)->mux);
1664
1665 fd_install(newfd, newfile);
1666 *newsockp = newsock;
1667 info->fd = newfd;
1668
1669 return 0;
1670
1671out_sk_alloc_fail:
1672 fput(newfile);
1673out_sock_alloc_fail:
1674 put_unused_fd(newfd);
1675out_fd_fail:
1676 sock_release(newsock);
1677out:
1678 return err;
1679}
1680
1681static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1682{
1683 int err;
1684
1685 switch (cmd) {
1686 case SIOCKCMATTACH: {
1687 struct kcm_attach info;
1688
1689 if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
1690 err = -EFAULT;
1691
1692 err = kcm_attach_ioctl(sock, &info);
1693
1694 break;
1695 }
1696 case SIOCKCMUNATTACH: {
1697 struct kcm_unattach info;
1698
1699 if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
1700 err = -EFAULT;
1701
1702 err = kcm_unattach_ioctl(sock, &info);
1703
1704 break;
1705 }
1706 case SIOCKCMCLONE: {
1707 struct kcm_clone info;
1708 struct socket *newsock = NULL;
1709
1710 if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
1711 err = -EFAULT;
1712
1713 err = kcm_clone(sock, &info, &newsock);
1714
1715 if (!err) {
1716 if (copy_to_user((void __user *)arg, &info,
1717 sizeof(info))) {
1718 err = -EFAULT;
WANG Congc0338af2016-08-28 21:28:26 -07001719 sys_close(info.fd);
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001720 }
1721 }
1722
1723 break;
1724 }
1725 default:
1726 err = -ENOIOCTLCMD;
1727 break;
1728 }
1729
1730 return err;
1731}
1732
1733static void free_mux(struct rcu_head *rcu)
1734{
1735 struct kcm_mux *mux = container_of(rcu,
1736 struct kcm_mux, rcu);
1737
1738 kmem_cache_free(kcm_muxp, mux);
1739}
1740
1741static void release_mux(struct kcm_mux *mux)
1742{
1743 struct kcm_net *knet = mux->knet;
1744 struct kcm_psock *psock, *tmp_psock;
1745
1746 /* Release psocks */
1747 list_for_each_entry_safe(psock, tmp_psock,
1748 &mux->psocks, psock_list) {
Tom Herbert1616b382016-08-23 11:55:31 -07001749 if (!WARN_ON(psock->unattaching))
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001750 kcm_unattach(psock);
1751 }
1752
1753 if (WARN_ON(mux->psocks_cnt))
1754 return;
1755
1756 __skb_queue_purge(&mux->rx_hold_queue);
1757
1758 mutex_lock(&knet->mutex);
Tom Herbertcd6e1112016-03-07 14:11:07 -08001759 aggregate_mux_stats(&mux->stats, &knet->aggregate_mux_stats);
1760 aggregate_psock_stats(&mux->aggregate_psock_stats,
1761 &knet->aggregate_psock_stats);
Tom Herbert9b738962016-08-15 14:51:02 -07001762 aggregate_strp_stats(&mux->aggregate_strp_stats,
1763 &knet->aggregate_strp_stats);
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001764 list_del_rcu(&mux->kcm_mux_list);
1765 knet->count--;
1766 mutex_unlock(&knet->mutex);
1767
1768 call_rcu(&mux->rcu, free_mux);
1769}
1770
1771static void kcm_done(struct kcm_sock *kcm)
1772{
1773 struct kcm_mux *mux = kcm->mux;
1774 struct sock *sk = &kcm->sk;
1775 int socks_cnt;
1776
1777 spin_lock_bh(&mux->rx_lock);
1778 if (kcm->rx_psock) {
1779 /* Cleanup in unreserve_rx_kcm */
1780 WARN_ON(kcm->done);
1781 kcm->rx_disabled = 1;
1782 kcm->done = 1;
1783 spin_unlock_bh(&mux->rx_lock);
1784 return;
1785 }
1786
1787 if (kcm->rx_wait) {
1788 list_del(&kcm->wait_rx_list);
1789 kcm->rx_wait = false;
1790 }
1791 /* Move any pending receive messages to other kcm sockets */
1792 requeue_rx_msgs(mux, &sk->sk_receive_queue);
1793
1794 spin_unlock_bh(&mux->rx_lock);
1795
1796 if (WARN_ON(sk_rmem_alloc_get(sk)))
1797 return;
1798
1799 /* Detach from MUX */
1800 spin_lock_bh(&mux->lock);
1801
1802 list_del(&kcm->kcm_sock_list);
1803 mux->kcm_socks_cnt--;
1804 socks_cnt = mux->kcm_socks_cnt;
1805
1806 spin_unlock_bh(&mux->lock);
1807
1808 if (!socks_cnt) {
1809 /* We are done with the mux now. */
1810 release_mux(mux);
1811 }
1812
1813 WARN_ON(kcm->rx_wait);
1814
1815 sock_put(&kcm->sk);
1816}
1817
1818/* Called by kcm_release to close a KCM socket.
1819 * If this is the last KCM socket on the MUX, destroy the MUX.
1820 */
1821static int kcm_release(struct socket *sock)
1822{
1823 struct sock *sk = sock->sk;
1824 struct kcm_sock *kcm;
1825 struct kcm_mux *mux;
1826 struct kcm_psock *psock;
1827
1828 if (!sk)
1829 return 0;
1830
1831 kcm = kcm_sk(sk);
1832 mux = kcm->mux;
1833
1834 sock_orphan(sk);
1835 kfree_skb(kcm->seq_skb);
1836
1837 lock_sock(sk);
1838 /* Purge queue under lock to avoid race condition with tx_work trying
1839 * to act when queue is nonempty. If tx_work runs after this point
1840 * it will just return.
1841 */
1842 __skb_queue_purge(&sk->sk_write_queue);
Tom Herbert9b738962016-08-15 14:51:02 -07001843
1844 /* Set tx_stopped. This is checked when psock is bound to a kcm and we
1845 * get a writespace callback. This prevents further work being queued
1846 * from the callback (unbinding the psock occurs after canceling work.
1847 */
1848 kcm->tx_stopped = 1;
1849
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001850 release_sock(sk);
1851
1852 spin_lock_bh(&mux->lock);
1853 if (kcm->tx_wait) {
1854 /* Take of tx_wait list, after this point there should be no way
1855 * that a psock will be assigned to this kcm.
1856 */
1857 list_del(&kcm->wait_psock_list);
1858 kcm->tx_wait = false;
1859 }
1860 spin_unlock_bh(&mux->lock);
1861
1862 /* Cancel work. After this point there should be no outside references
1863 * to the kcm socket.
1864 */
1865 cancel_work_sync(&kcm->tx_work);
1866
1867 lock_sock(sk);
1868 psock = kcm->tx_psock;
1869 if (psock) {
1870 /* A psock was reserved, so we need to kill it since it
1871 * may already have some bytes queued from a message. We
1872 * need to do this after removing kcm from tx_wait list.
1873 */
1874 kcm_abort_tx_psock(psock, EPIPE, false);
1875 unreserve_psock(kcm);
1876 }
1877 release_sock(sk);
1878
1879 WARN_ON(kcm->tx_wait);
1880 WARN_ON(kcm->tx_psock);
1881
1882 sock->sk = NULL;
1883
1884 kcm_done(kcm);
1885
1886 return 0;
1887}
1888
Tom Herbert91687352016-03-07 14:11:08 -08001889static const struct proto_ops kcm_dgram_ops = {
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001890 .family = PF_KCM,
1891 .owner = THIS_MODULE,
1892 .release = kcm_release,
1893 .bind = sock_no_bind,
1894 .connect = sock_no_connect,
1895 .socketpair = sock_no_socketpair,
1896 .accept = sock_no_accept,
1897 .getname = sock_no_getname,
1898 .poll = datagram_poll,
1899 .ioctl = kcm_ioctl,
1900 .listen = sock_no_listen,
1901 .shutdown = sock_no_shutdown,
1902 .setsockopt = kcm_setsockopt,
1903 .getsockopt = kcm_getsockopt,
1904 .sendmsg = kcm_sendmsg,
1905 .recvmsg = kcm_recvmsg,
1906 .mmap = sock_no_mmap,
Tom Herbertf29698fc2016-03-07 14:11:09 -08001907 .sendpage = kcm_sendpage,
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001908};
1909
Tom Herbert91687352016-03-07 14:11:08 -08001910static const struct proto_ops kcm_seqpacket_ops = {
1911 .family = PF_KCM,
1912 .owner = THIS_MODULE,
1913 .release = kcm_release,
1914 .bind = sock_no_bind,
1915 .connect = sock_no_connect,
1916 .socketpair = sock_no_socketpair,
1917 .accept = sock_no_accept,
1918 .getname = sock_no_getname,
1919 .poll = datagram_poll,
1920 .ioctl = kcm_ioctl,
1921 .listen = sock_no_listen,
1922 .shutdown = sock_no_shutdown,
1923 .setsockopt = kcm_setsockopt,
1924 .getsockopt = kcm_getsockopt,
1925 .sendmsg = kcm_sendmsg,
1926 .recvmsg = kcm_recvmsg,
1927 .mmap = sock_no_mmap,
Tom Herbertf29698fc2016-03-07 14:11:09 -08001928 .sendpage = kcm_sendpage,
Tom Herbert91687352016-03-07 14:11:08 -08001929 .splice_read = kcm_splice_read,
1930};
1931
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001932/* Create proto operation for kcm sockets */
1933static int kcm_create(struct net *net, struct socket *sock,
1934 int protocol, int kern)
1935{
1936 struct kcm_net *knet = net_generic(net, kcm_net_id);
1937 struct sock *sk;
1938 struct kcm_mux *mux;
1939
1940 switch (sock->type) {
1941 case SOCK_DGRAM:
Tom Herbert91687352016-03-07 14:11:08 -08001942 sock->ops = &kcm_dgram_ops;
1943 break;
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001944 case SOCK_SEQPACKET:
Tom Herbert91687352016-03-07 14:11:08 -08001945 sock->ops = &kcm_seqpacket_ops;
Tom Herbertab7ac4e2016-03-07 14:11:06 -08001946 break;
1947 default:
1948 return -ESOCKTNOSUPPORT;
1949 }
1950
1951 if (protocol != KCMPROTO_CONNECTED)
1952 return -EPROTONOSUPPORT;
1953
1954 sk = sk_alloc(net, PF_KCM, GFP_KERNEL, &kcm_proto, kern);
1955 if (!sk)
1956 return -ENOMEM;
1957
1958 /* Allocate a kcm mux, shared between KCM sockets */
1959 mux = kmem_cache_zalloc(kcm_muxp, GFP_KERNEL);
1960 if (!mux) {
1961 sk_free(sk);
1962 return -ENOMEM;
1963 }
1964
1965 spin_lock_init(&mux->lock);
1966 spin_lock_init(&mux->rx_lock);
1967 INIT_LIST_HEAD(&mux->kcm_socks);
1968 INIT_LIST_HEAD(&mux->kcm_rx_waiters);
1969 INIT_LIST_HEAD(&mux->kcm_tx_waiters);
1970
1971 INIT_LIST_HEAD(&mux->psocks);
1972 INIT_LIST_HEAD(&mux->psocks_ready);
1973 INIT_LIST_HEAD(&mux->psocks_avail);
1974
1975 mux->knet = knet;
1976
1977 /* Add new MUX to list */
1978 mutex_lock(&knet->mutex);
1979 list_add_rcu(&mux->kcm_mux_list, &knet->mux_list);
1980 knet->count++;
1981 mutex_unlock(&knet->mutex);
1982
1983 skb_queue_head_init(&mux->rx_hold_queue);
1984
1985 /* Init KCM socket */
1986 sock_init_data(sock, sk);
1987 init_kcm_sock(kcm_sk(sk), mux);
1988
1989 return 0;
1990}
1991
1992static struct net_proto_family kcm_family_ops = {
1993 .family = PF_KCM,
1994 .create = kcm_create,
1995 .owner = THIS_MODULE,
1996};
1997
1998static __net_init int kcm_init_net(struct net *net)
1999{
2000 struct kcm_net *knet = net_generic(net, kcm_net_id);
2001
2002 INIT_LIST_HEAD_RCU(&knet->mux_list);
2003 mutex_init(&knet->mutex);
2004
2005 return 0;
2006}
2007
2008static __net_exit void kcm_exit_net(struct net *net)
2009{
2010 struct kcm_net *knet = net_generic(net, kcm_net_id);
2011
2012 /* All KCM sockets should be closed at this point, which should mean
2013 * that all multiplexors and psocks have been destroyed.
2014 */
2015 WARN_ON(!list_empty(&knet->mux_list));
2016}
2017
2018static struct pernet_operations kcm_net_ops = {
2019 .init = kcm_init_net,
2020 .exit = kcm_exit_net,
2021 .id = &kcm_net_id,
2022 .size = sizeof(struct kcm_net),
2023};
2024
2025static int __init kcm_init(void)
2026{
2027 int err = -ENOMEM;
2028
2029 kcm_muxp = kmem_cache_create("kcm_mux_cache",
2030 sizeof(struct kcm_mux), 0,
2031 SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
2032 if (!kcm_muxp)
2033 goto fail;
2034
2035 kcm_psockp = kmem_cache_create("kcm_psock_cache",
2036 sizeof(struct kcm_psock), 0,
2037 SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
2038 if (!kcm_psockp)
2039 goto fail;
2040
2041 kcm_wq = create_singlethread_workqueue("kkcmd");
2042 if (!kcm_wq)
2043 goto fail;
2044
2045 err = proto_register(&kcm_proto, 1);
2046 if (err)
2047 goto fail;
2048
2049 err = sock_register(&kcm_family_ops);
2050 if (err)
2051 goto sock_register_fail;
2052
2053 err = register_pernet_device(&kcm_net_ops);
2054 if (err)
2055 goto net_ops_fail;
2056
Tom Herbertcd6e1112016-03-07 14:11:07 -08002057 err = kcm_proc_init();
2058 if (err)
2059 goto proc_init_fail;
2060
Tom Herbertab7ac4e2016-03-07 14:11:06 -08002061 return 0;
2062
Tom Herbertcd6e1112016-03-07 14:11:07 -08002063proc_init_fail:
2064 unregister_pernet_device(&kcm_net_ops);
2065
Tom Herbertab7ac4e2016-03-07 14:11:06 -08002066net_ops_fail:
2067 sock_unregister(PF_KCM);
2068
2069sock_register_fail:
2070 proto_unregister(&kcm_proto);
2071
2072fail:
2073 kmem_cache_destroy(kcm_muxp);
2074 kmem_cache_destroy(kcm_psockp);
2075
2076 if (kcm_wq)
2077 destroy_workqueue(kcm_wq);
2078
2079 return err;
2080}
2081
2082static void __exit kcm_exit(void)
2083{
Tom Herbertcd6e1112016-03-07 14:11:07 -08002084 kcm_proc_exit();
Tom Herbertab7ac4e2016-03-07 14:11:06 -08002085 unregister_pernet_device(&kcm_net_ops);
2086 sock_unregister(PF_KCM);
2087 proto_unregister(&kcm_proto);
2088 destroy_workqueue(kcm_wq);
2089
2090 kmem_cache_destroy(kcm_muxp);
2091 kmem_cache_destroy(kcm_psockp);
2092}
2093
2094module_init(kcm_init);
2095module_exit(kcm_exit);
2096
2097MODULE_LICENSE("GPL");
2098MODULE_ALIAS_NETPROTO(PF_KCM);
2099