~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/net/kcm/kcmsock.c

Version: ~ [ linux-5.10-rc1 ] ~ [ linux-5.9.1 ] ~ [ linux-5.8.16 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.72 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.152 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.202 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.240 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.240 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  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 
 11 #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>
 26 #include <linux/syscalls.h>
 27 #include <linux/sched/signal.h>
 28 
 29 #include <net/kcm.h>
 30 #include <net/netns/generic.h>
 31 #include <net/sock.h>
 32 #include <uapi/linux/kcm.h>
 33 
 34 unsigned int kcm_net_id;
 35 
 36 static struct kmem_cache *kcm_psockp __read_mostly;
 37 static struct kmem_cache *kcm_muxp __read_mostly;
 38 static struct workqueue_struct *kcm_wq;
 39 
 40 static inline struct kcm_sock *kcm_sk(const struct sock *sk)
 41 {
 42         return (struct kcm_sock *)sk;
 43 }
 44 
 45 static inline struct kcm_tx_msg *kcm_tx_msg(struct sk_buff *skb)
 46 {
 47         return (struct kcm_tx_msg *)skb->cb;
 48 }
 49 
 50 static void report_csk_error(struct sock *csk, int err)
 51 {
 52         csk->sk_err = EPIPE;
 53         csk->sk_error_report(csk);
 54 }
 55 
 56 static 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;
 72         KCM_STATS_INCR(psock->stats.tx_aborts);
 73 
 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 
 94 /* RX mux lock held. */
 95 static void kcm_update_rx_mux_stats(struct kcm_mux *mux,
 96                                     struct kcm_psock *psock)
 97 {
 98         STRP_STATS_ADD(mux->stats.rx_bytes,
 99                        psock->strp.stats.bytes -
100                        psock->saved_rx_bytes);
101         mux->stats.rx_msgs +=
102                 psock->strp.stats.msgs - psock->saved_rx_msgs;
103         psock->saved_rx_msgs = psock->strp.stats.msgs;
104         psock->saved_rx_bytes = psock->strp.stats.bytes;
105 }
106 
107 static 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 
118 static 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  */
124 static 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;
157                 /* Commit clearing of ready_rx_msg for queuing work */
158                 smp_mb();
159 
160                 strp_unpause(&psock->strp);
161                 strp_check_rcv(&psock->strp);
162         }
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 
170 static void kcm_rfree(struct sk_buff *skb)
171 {
172         struct sock *sk = skb->sk;
173         struct kcm_sock *kcm = kcm_sk(sk);
174         struct kcm_mux *mux = kcm->mux;
175         unsigned int len = skb->truesize;
176 
177         sk_mem_uncharge(sk, len);
178         atomic_sub(len, &sk->sk_rmem_alloc);
179 
180         /* For reading rx_wait and rx_psock without holding lock */
181         smp_mb__after_atomic();
182 
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 
191 static int kcm_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
192 {
193         struct sk_buff_head *list = &sk->sk_receive_queue;
194 
195         if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
196                 return -ENOMEM;
197 
198         if (!sk_rmem_schedule(sk, skb, skb->truesize))
199                 return -ENOBUFS;
200 
201         skb->dev = NULL;
202 
203         skb_orphan(skb);
204         skb->sk = sk;
205         skb->destructor = kcm_rfree;
206         atomic_add(skb->truesize, &sk->sk_rmem_alloc);
207         sk_mem_charge(sk, skb->truesize);
208 
209         skb_queue_tail(list, skb);
210 
211         if (!sock_flag(sk, SOCK_DEAD))
212                 sk->sk_data_ready(sk);
213 
214         return 0;
215 }
216 
217 /* Requeue received messages for a kcm socket to other kcm sockets. This is
218  * called with a kcm socket is receive disabled.
219  * RX mux lock held.
220  */
221 static void requeue_rx_msgs(struct kcm_mux *mux, struct sk_buff_head *head)
222 {
223         struct sk_buff *skb;
224         struct kcm_sock *kcm;
225 
226         while ((skb = __skb_dequeue(head))) {
227                 /* Reset destructor to avoid calling kcm_rcv_ready */
228                 skb->destructor = sock_rfree;
229                 skb_orphan(skb);
230 try_again:
231                 if (list_empty(&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 */
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 
271         kcm_update_rx_mux_stats(mux, psock);
272 
273         if (list_empty(&mux->kcm_rx_waiters)) {
274                 psock->ready_rx_msg = head;
275                 strp_pause(&psock->strp);
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);
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 
295 static void kcm_done(struct kcm_sock *kcm);
296 
297 static 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 */
303 static 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 
344 /* Lower sock lock held */
345 static void psock_data_ready(struct sock *sk)
346 {
347         struct kcm_psock *psock;
348 
349         read_lock_bh(&sk->sk_callback_lock);
350 
351         psock = (struct kcm_psock *)sk->sk_user_data;
352         if (likely(psock))
353                 strp_data_ready(&psock->strp);
354 
355         read_unlock_bh(&sk->sk_callback_lock);
356 }
357 
358 /* Called with lower sock held */
359 static void kcm_rcv_strparser(struct strparser *strp, struct sk_buff *skb)
360 {
361         struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp);
362         struct kcm_sock *kcm;
363 
364 try_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         }
372 
373         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         }
378 }
379 
380 static int kcm_parse_func_strparser(struct strparser *strp, struct sk_buff *skb)
381 {
382         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);
386 }
387 
388 static int kcm_read_sock_done(struct strparser *strp, int err)
389 {
390         struct kcm_psock *psock = container_of(strp, struct kcm_psock, strp);
391 
392         unreserve_rx_kcm(psock, true);
393 
394         return err;
395 }
396 
397 static void psock_state_change(struct sock *sk)
398 {
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 
407 static void psock_write_space(struct sock *sk)
408 {
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;
418         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;
424         if (kcm && !unlikely(kcm->tx_stopped))
425                 queue_work(kcm_wq, &kcm->tx_work);
426 
427         spin_unlock_bh(&mux->lock);
428 out:
429         read_unlock_bh(&sk->sk_callback_lock);
430 }
431 
432 static void unreserve_psock(struct kcm_sock *kcm);
433 
434 /* kcm sock is locked. */
435 static 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;
475                 KCM_STATS_INCR(psock->stats.reserved);
476         } 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 */
488 static 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;
510                 KCM_STATS_INCR(psock->stats.reserved);
511                 queue_work(kcm_wq, &kcm->tx_work);
512         }
513 }
514 
515 /* kcm sock is locked. */
516 static 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 
532         kcm_update_tx_mux_stats(mux, psock);
533 
534         WARN_ON(kcm->tx_wait);
535 
536         kcm->tx_psock = NULL;
537         psock->tx_kcm = NULL;
538         KCM_STATS_INCR(psock->stats.unreserved);
539 
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 
562 static 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 
571 /* Write any messages ready on the kcm socket.  Called with kcm sock lock
572  * held.  Return bytes actually sent or error.
573  */
574 static 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);
591                 kcm_report_tx_retry(kcm);
592                 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 
618 try_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 
628 do_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;
639 do_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;
675                                 kcm_report_tx_retry(kcm);
676                                 ret = 0;
677 
678                                 goto try_again;
679                         }
680 
681                         sent += ret;
682                         frag_offset += ret;
683                         KCM_STATS_ADD(psock->stats.tx_bytes, ret);
684                         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;
705                 KCM_STATS_INCR(psock->stats.tx_msgs);
706         } while ((head = skb_peek(&sk->sk_write_queue)));
707 out:
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 
720 static 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 
746 out:
747         release_sock(sk);
748 }
749 
750 static void kcm_push(struct kcm_sock *kcm)
751 {
752         if (kcm->tx_wait_more)
753                 kcm_write_msgs(kcm);
754 }
755 
756 static 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 
840 coalesced:
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 
886 out_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 
899 static 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 
934         if (msg_data_left(msg)) {
935                 /* New message, alloc head skb */
936                 head = alloc_skb(0, sk->sk_allocation);
937                 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;
952         }
953 
954 start:
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 
1015 wait_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 
1025                 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                 }
1031 
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 */
1048 partial_message:
1049                 if (head) {
1050                         kcm->seq_skb = head;
1051                         kcm_tx_msg(head)->last_skb = skb;
1052                 }
1053         }
1054 
1055         KCM_STATS_ADD(kcm->stats.tx_bytes, copied);
1056 
1057         release_sock(sk);
1058         return copied;
1059 
1060 out_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 
1083 static 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 
1114 static int kcm_recvmsg(struct socket *sock, struct msghdr *msg,
1115                        size_t len, int flags)
1116 {
1117         struct sock *sk = sock->sk;
1118         struct kcm_sock *kcm = kcm_sk(sk);
1119         int err = 0;
1120         long timeo;
1121         struct strp_msg *stm;
1122         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 
1135         stm = strp_msg(skb);
1136 
1137         if (len > stm->full_len)
1138                 len = stm->full_len;
1139 
1140         err = skb_copy_datagram_msg(skb, stm->offset, msg, len);
1141         if (err < 0)
1142                 goto out;
1143 
1144         copied = len;
1145         if (likely(!(flags & MSG_PEEK))) {
1146                 KCM_STATS_ADD(kcm->stats.rx_bytes, copied);
1147                 if (copied < stm->full_len) {
1148                         if (sock->type == SOCK_DGRAM) {
1149                                 /* Truncated message */
1150                                 msg->msg_flags |= MSG_TRUNC;
1151                                 goto msg_finished;
1152                         }
1153                         stm->offset += copied;
1154                         stm->full_len -= copied;
1155                 } else {
1156 msg_finished:
1157                         /* Finished with message */
1158                         msg->msg_flags |= MSG_EOR;
1159                         KCM_STATS_INCR(kcm->stats.rx_msgs);
1160                         skb_unlink(skb, &sk->sk_receive_queue);
1161                         kfree_skb(skb);
1162                 }
1163         }
1164 
1165 out:
1166         release_sock(sk);
1167 
1168         return copied ? : err;
1169 }
1170 
1171 static 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;
1178         struct strp_msg *stm;
1179         int err = 0;
1180         ssize_t copied;
1181         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 
1195         stm = strp_msg(skb);
1196 
1197         if (len > stm->full_len)
1198                 len = stm->full_len;
1199 
1200         copied = skb_splice_bits(skb, sk, stm->offset, pipe, len, flags);
1201         if (copied < 0) {
1202                 err = copied;
1203                 goto err_out;
1204         }
1205 
1206         KCM_STATS_ADD(kcm->stats.rx_bytes, copied);
1207 
1208         stm->offset += copied;
1209         stm->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 
1221 err_out:
1222         release_sock(sk);
1223 
1224         return err;
1225 }
1226 
1227 /* kcm sock lock held */
1228 static 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 */
1253 static 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 
1268 static 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 
1302 static 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 
1333 static 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 
1370 static 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;
1379         static const struct strp_callbacks cb = {
1380                 .rcv_msg = kcm_rcv_strparser,
1381                 .parse_msg = kcm_parse_func_strparser,
1382                 .read_sock_done = kcm_read_sock_done,
1383         };
1384         int err = 0;
1385 
1386         csk = csock->sk;
1387         if (!csk)
1388                 return -EINVAL;
1389 
1390         lock_sock(csk);
1391 
1392         /* Only allow TCP sockets to be attached for now */
1393         if ((csk->sk_family != AF_INET && csk->sk_family != AF_INET6) ||
1394             csk->sk_protocol != IPPROTO_TCP) {
1395                 err = -EOPNOTSUPP;
1396                 goto out;
1397         }
1398 
1399         /* Don't allow listeners or closed sockets */
1400         if (csk->sk_state == TCP_LISTEN || csk->sk_state == TCP_CLOSE) {
1401                 err = -EOPNOTSUPP;
1402                 goto out;
1403         }
1404 
1405         psock = kmem_cache_zalloc(kcm_psockp, GFP_KERNEL);
1406         if (!psock) {
1407                 err = -ENOMEM;
1408                 goto out;
1409         }
1410 
1411         psock->mux = mux;
1412         psock->sk = csk;
1413         psock->bpf_prog = prog;
1414 
1415         err = strp_init(&psock->strp, csk, &cb);
1416         if (err) {
1417                 kmem_cache_free(kcm_psockp, psock);
1418                 goto out;
1419         }
1420 
1421         write_lock_bh(&csk->sk_callback_lock);
1422 
1423         /* Check if sk_user_data is aready by KCM or someone else.
1424          * Must be done under lock to prevent race conditions.
1425          */
1426         if (csk->sk_user_data) {
1427                 write_unlock_bh(&csk->sk_callback_lock);
1428                 strp_done(&psock->strp);
1429                 kmem_cache_free(kcm_psockp, psock);
1430                 err = -EALREADY;
1431                 goto out;
1432         }
1433 
1434         psock->save_data_ready = csk->sk_data_ready;
1435         psock->save_write_space = csk->sk_write_space;
1436         psock->save_state_change = csk->sk_state_change;
1437         csk->sk_user_data = psock;
1438         csk->sk_data_ready = psock_data_ready;
1439         csk->sk_write_space = psock_write_space;
1440         csk->sk_state_change = psock_state_change;
1441 
1442         write_unlock_bh(&csk->sk_callback_lock);
1443 
1444         sock_hold(csk);
1445 
1446         /* Finished initialization, now add the psock to the MUX. */
1447         spin_lock_bh(&mux->lock);
1448         head = &mux->psocks;
1449         list_for_each_entry(tpsock, &mux->psocks, psock_list) {
1450                 if (tpsock->index != index)
1451                         break;
1452                 head = &tpsock->psock_list;
1453                 index++;
1454         }
1455 
1456         list_add(&psock->psock_list, head);
1457         psock->index = index;
1458 
1459         KCM_STATS_INCR(mux->stats.psock_attach);
1460         mux->psocks_cnt++;
1461         psock_now_avail(psock);
1462         spin_unlock_bh(&mux->lock);
1463 
1464         /* Schedule RX work in case there are already bytes queued */
1465         strp_check_rcv(&psock->strp);
1466 
1467 out:
1468         release_sock(csk);
1469 
1470         return err;
1471 }
1472 
1473 static int kcm_attach_ioctl(struct socket *sock, struct kcm_attach *info)
1474 {
1475         struct socket *csock;
1476         struct bpf_prog *prog;
1477         int err;
1478 
1479         csock = sockfd_lookup(info->fd, &err);
1480         if (!csock)
1481                 return -ENOENT;
1482 
1483         prog = bpf_prog_get_type(info->bpf_fd, BPF_PROG_TYPE_SOCKET_FILTER);
1484         if (IS_ERR(prog)) {
1485                 err = PTR_ERR(prog);
1486                 goto out;
1487         }
1488 
1489         err = kcm_attach(sock, csock, prog);
1490         if (err) {
1491                 bpf_prog_put(prog);
1492                 goto out;
1493         }
1494 
1495         /* Keep reference on file also */
1496 
1497         return 0;
1498 out:
1499         fput(csock->file);
1500         return err;
1501 }
1502 
1503 static void kcm_unattach(struct kcm_psock *psock)
1504 {
1505         struct sock *csk = psock->sk;
1506         struct kcm_mux *mux = psock->mux;
1507 
1508         lock_sock(csk);
1509 
1510         /* Stop getting callbacks from TCP socket. After this there should
1511          * be no way to reserve a kcm for this psock.
1512          */
1513         write_lock_bh(&csk->sk_callback_lock);
1514         csk->sk_user_data = NULL;
1515         csk->sk_data_ready = psock->save_data_ready;
1516         csk->sk_write_space = psock->save_write_space;
1517         csk->sk_state_change = psock->save_state_change;
1518         strp_stop(&psock->strp);
1519 
1520         if (WARN_ON(psock->rx_kcm)) {
1521                 write_unlock_bh(&csk->sk_callback_lock);
1522                 release_sock(csk);
1523                 return;
1524         }
1525 
1526         spin_lock_bh(&mux->rx_lock);
1527 
1528         /* Stop receiver activities. After this point psock should not be
1529          * able to get onto ready list either through callbacks or work.
1530          */
1531         if (psock->ready_rx_msg) {
1532                 list_del(&psock->psock_ready_list);
1533                 kfree_skb(psock->ready_rx_msg);
1534                 psock->ready_rx_msg = NULL;
1535                 KCM_STATS_INCR(mux->stats.rx_ready_drops);
1536         }
1537 
1538         spin_unlock_bh(&mux->rx_lock);
1539 
1540         write_unlock_bh(&csk->sk_callback_lock);
1541 
1542         /* Call strp_done without sock lock */
1543         release_sock(csk);
1544         strp_done(&psock->strp);
1545         lock_sock(csk);
1546 
1547         bpf_prog_put(psock->bpf_prog);
1548 
1549         spin_lock_bh(&mux->lock);
1550 
1551         aggregate_psock_stats(&psock->stats, &mux->aggregate_psock_stats);
1552         save_strp_stats(&psock->strp, &mux->aggregate_strp_stats);
1553 
1554         KCM_STATS_INCR(mux->stats.psock_unattach);
1555 
1556         if (psock->tx_kcm) {
1557                 /* psock was reserved.  Just mark it finished and we will clean
1558                  * up in the kcm paths, we need kcm lock which can not be
1559                  * acquired here.
1560                  */
1561                 KCM_STATS_INCR(mux->stats.psock_unattach_rsvd);
1562                 spin_unlock_bh(&mux->lock);
1563 
1564                 /* We are unattaching a socket that is reserved. Abort the
1565                  * socket since we may be out of sync in sending on it. We need
1566                  * to do this without the mux lock.
1567                  */
1568                 kcm_abort_tx_psock(psock, EPIPE, false);
1569 
1570                 spin_lock_bh(&mux->lock);
1571                 if (!psock->tx_kcm) {
1572                         /* psock now unreserved in window mux was unlocked */
1573                         goto no_reserved;
1574                 }
1575                 psock->done = 1;
1576 
1577                 /* Commit done before queuing work to process it */
1578                 smp_mb();
1579 
1580                 /* Queue tx work to make sure psock->done is handled */
1581                 queue_work(kcm_wq, &psock->tx_kcm->tx_work);
1582                 spin_unlock_bh(&mux->lock);
1583         } else {
1584 no_reserved:
1585                 if (!psock->tx_stopped)
1586                         list_del(&psock->psock_avail_list);
1587                 list_del(&psock->psock_list);
1588                 mux->psocks_cnt--;
1589                 spin_unlock_bh(&mux->lock);
1590 
1591                 sock_put(csk);
1592                 fput(csk->sk_socket->file);
1593                 kmem_cache_free(kcm_psockp, psock);
1594         }
1595 
1596         release_sock(csk);
1597 }
1598 
1599 static int kcm_unattach_ioctl(struct socket *sock, struct kcm_unattach *info)
1600 {
1601         struct kcm_sock *kcm = kcm_sk(sock->sk);
1602         struct kcm_mux *mux = kcm->mux;
1603         struct kcm_psock *psock;
1604         struct socket *csock;
1605         struct sock *csk;
1606         int err;
1607 
1608         csock = sockfd_lookup(info->fd, &err);
1609         if (!csock)
1610                 return -ENOENT;
1611 
1612         csk = csock->sk;
1613         if (!csk) {
1614                 err = -EINVAL;
1615                 goto out;
1616         }
1617 
1618         err = -ENOENT;
1619 
1620         spin_lock_bh(&mux->lock);
1621 
1622         list_for_each_entry(psock, &mux->psocks, psock_list) {
1623                 if (psock->sk != csk)
1624                         continue;
1625 
1626                 /* Found the matching psock */
1627 
1628                 if (psock->unattaching || WARN_ON(psock->done)) {
1629                         err = -EALREADY;
1630                         break;
1631                 }
1632 
1633                 psock->unattaching = 1;
1634 
1635                 spin_unlock_bh(&mux->lock);
1636 
1637                 /* Lower socket lock should already be held */
1638                 kcm_unattach(psock);
1639 
1640                 err = 0;
1641                 goto out;
1642         }
1643 
1644         spin_unlock_bh(&mux->lock);
1645 
1646 out:
1647         fput(csock->file);
1648         return err;
1649 }
1650 
1651 static struct proto kcm_proto = {
1652         .name   = "KCM",
1653         .owner  = THIS_MODULE,
1654         .obj_size = sizeof(struct kcm_sock),
1655 };
1656 
1657 /* Clone a kcm socket. */
1658 static struct file *kcm_clone(struct socket *osock)
1659 {
1660         struct socket *newsock;
1661         struct sock *newsk;
1662 
1663         newsock = sock_alloc();
1664         if (!newsock)
1665                 return ERR_PTR(-ENFILE);
1666 
1667         newsock->type = osock->type;
1668         newsock->ops = osock->ops;
1669 
1670         __module_get(newsock->ops->owner);
1671 
1672         newsk = sk_alloc(sock_net(osock->sk), PF_KCM, GFP_KERNEL,
1673                          &kcm_proto, true);
1674         if (!newsk) {
1675                 sock_release(newsock);
1676                 return ERR_PTR(-ENOMEM);
1677         }
1678         sock_init_data(newsock, newsk);
1679         init_kcm_sock(kcm_sk(newsk), kcm_sk(osock->sk)->mux);
1680 
1681         return sock_alloc_file(newsock, 0, osock->sk->sk_prot_creator->name);
1682 }
1683 
1684 static int kcm_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1685 {
1686         int err;
1687 
1688         switch (cmd) {
1689         case SIOCKCMATTACH: {
1690                 struct kcm_attach info;
1691 
1692                 if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
1693                         return -EFAULT;
1694 
1695                 err = kcm_attach_ioctl(sock, &info);
1696 
1697                 break;
1698         }
1699         case SIOCKCMUNATTACH: {
1700                 struct kcm_unattach info;
1701 
1702                 if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
1703                         return -EFAULT;
1704 
1705                 err = kcm_unattach_ioctl(sock, &info);
1706 
1707                 break;
1708         }
1709         case SIOCKCMCLONE: {
1710                 struct kcm_clone info;
1711                 struct file *file;
1712 
1713                 info.fd = get_unused_fd_flags(0);
1714                 if (unlikely(info.fd < 0))
1715                         return info.fd;
1716 
1717                 file = kcm_clone(sock);
1718                 if (IS_ERR(file)) {
1719                         put_unused_fd(info.fd);
1720                         return PTR_ERR(file);
1721                 }
1722                 if (copy_to_user((void __user *)arg, &info,
1723                                  sizeof(info))) {
1724                         put_unused_fd(info.fd);
1725                         fput(file);
1726                         return -EFAULT;
1727                 }
1728                 fd_install(info.fd, file);
1729                 err = 0;
1730                 break;
1731         }
1732         default:
1733                 err = -ENOIOCTLCMD;
1734                 break;
1735         }
1736 
1737         return err;
1738 }
1739 
1740 static void free_mux(struct rcu_head *rcu)
1741 {
1742         struct kcm_mux *mux = container_of(rcu,
1743             struct kcm_mux, rcu);
1744 
1745         kmem_cache_free(kcm_muxp, mux);
1746 }
1747 
1748 static void release_mux(struct kcm_mux *mux)
1749 {
1750         struct kcm_net *knet = mux->knet;
1751         struct kcm_psock *psock, *tmp_psock;
1752 
1753         /* Release psocks */
1754         list_for_each_entry_safe(psock, tmp_psock,
1755                                  &mux->psocks, psock_list) {
1756                 if (!WARN_ON(psock->unattaching))
1757                         kcm_unattach(psock);
1758         }
1759 
1760         if (WARN_ON(mux->psocks_cnt))
1761                 return;
1762 
1763         __skb_queue_purge(&mux->rx_hold_queue);
1764 
1765         mutex_lock(&knet->mutex);
1766         aggregate_mux_stats(&mux->stats, &knet->aggregate_mux_stats);
1767         aggregate_psock_stats(&mux->aggregate_psock_stats,
1768                               &knet->aggregate_psock_stats);
1769         aggregate_strp_stats(&mux->aggregate_strp_stats,
1770                              &knet->aggregate_strp_stats);
1771         list_del_rcu(&mux->kcm_mux_list);
1772         knet->count--;
1773         mutex_unlock(&knet->mutex);
1774 
1775         call_rcu(&mux->rcu, free_mux);
1776 }
1777 
1778 static void kcm_done(struct kcm_sock *kcm)
1779 {
1780         struct kcm_mux *mux = kcm->mux;
1781         struct sock *sk = &kcm->sk;
1782         int socks_cnt;
1783 
1784         spin_lock_bh(&mux->rx_lock);
1785         if (kcm->rx_psock) {
1786                 /* Cleanup in unreserve_rx_kcm */
1787                 WARN_ON(kcm->done);
1788                 kcm->rx_disabled = 1;
1789                 kcm->done = 1;
1790                 spin_unlock_bh(&mux->rx_lock);
1791                 return;
1792         }
1793 
1794         if (kcm->rx_wait) {
1795                 list_del(&kcm->wait_rx_list);
1796                 kcm->rx_wait = false;
1797         }
1798         /* Move any pending receive messages to other kcm sockets */
1799         requeue_rx_msgs(mux, &sk->sk_receive_queue);
1800 
1801         spin_unlock_bh(&mux->rx_lock);
1802 
1803         if (WARN_ON(sk_rmem_alloc_get(sk)))
1804                 return;
1805 
1806         /* Detach from MUX */
1807         spin_lock_bh(&mux->lock);
1808 
1809         list_del(&kcm->kcm_sock_list);
1810         mux->kcm_socks_cnt--;
1811         socks_cnt = mux->kcm_socks_cnt;
1812 
1813         spin_unlock_bh(&mux->lock);
1814 
1815         if (!socks_cnt) {
1816                 /* We are done with the mux now. */
1817                 release_mux(mux);
1818         }
1819 
1820         WARN_ON(kcm->rx_wait);
1821 
1822         sock_put(&kcm->sk);
1823 }
1824 
1825 /* Called by kcm_release to close a KCM socket.
1826  * If this is the last KCM socket on the MUX, destroy the MUX.
1827  */
1828 static int kcm_release(struct socket *sock)
1829 {
1830         struct sock *sk = sock->sk;
1831         struct kcm_sock *kcm;
1832         struct kcm_mux *mux;
1833         struct kcm_psock *psock;
1834 
1835         if (!sk)
1836                 return 0;
1837 
1838         kcm = kcm_sk(sk);
1839         mux = kcm->mux;
1840 
1841         sock_orphan(sk);
1842         kfree_skb(kcm->seq_skb);
1843 
1844         lock_sock(sk);
1845         /* Purge queue under lock to avoid race condition with tx_work trying
1846          * to act when queue is nonempty. If tx_work runs after this point
1847          * it will just return.
1848          */
1849         __skb_queue_purge(&sk->sk_write_queue);
1850 
1851         /* Set tx_stopped. This is checked when psock is bound to a kcm and we
1852          * get a writespace callback. This prevents further work being queued
1853          * from the callback (unbinding the psock occurs after canceling work.
1854          */
1855         kcm->tx_stopped = 1;
1856 
1857         release_sock(sk);
1858 
1859         spin_lock_bh(&mux->lock);
1860         if (kcm->tx_wait) {
1861                 /* Take of tx_wait list, after this point there should be no way
1862                  * that a psock will be assigned to this kcm.
1863                  */
1864                 list_del(&kcm->wait_psock_list);
1865                 kcm->tx_wait = false;
1866         }
1867         spin_unlock_bh(&mux->lock);
1868 
1869         /* Cancel work. After this point there should be no outside references
1870          * to the kcm socket.
1871          */
1872         cancel_work_sync(&kcm->tx_work);
1873 
1874         lock_sock(sk);
1875         psock = kcm->tx_psock;
1876         if (psock) {
1877                 /* A psock was reserved, so we need to kill it since it
1878                  * may already have some bytes queued from a message. We
1879                  * need to do this after removing kcm from tx_wait list.
1880                  */
1881                 kcm_abort_tx_psock(psock, EPIPE, false);
1882                 unreserve_psock(kcm);
1883         }
1884         release_sock(sk);
1885 
1886         WARN_ON(kcm->tx_wait);
1887         WARN_ON(kcm->tx_psock);
1888 
1889         sock->sk = NULL;
1890 
1891         kcm_done(kcm);
1892 
1893         return 0;
1894 }
1895 
1896 static const struct proto_ops kcm_dgram_ops = {
1897         .family =       PF_KCM,
1898         .owner =        THIS_MODULE,
1899         .release =      kcm_release,
1900         .bind =         sock_no_bind,
1901         .connect =      sock_no_connect,
1902         .socketpair =   sock_no_socketpair,
1903         .accept =       sock_no_accept,
1904         .getname =      sock_no_getname,
1905         .poll =         datagram_poll,
1906         .ioctl =        kcm_ioctl,
1907         .listen =       sock_no_listen,
1908         .shutdown =     sock_no_shutdown,
1909         .setsockopt =   kcm_setsockopt,
1910         .getsockopt =   kcm_getsockopt,
1911         .sendmsg =      kcm_sendmsg,
1912         .recvmsg =      kcm_recvmsg,
1913         .mmap =         sock_no_mmap,
1914         .sendpage =     kcm_sendpage,
1915 };
1916 
1917 static const struct proto_ops kcm_seqpacket_ops = {
1918         .family =       PF_KCM,
1919         .owner =        THIS_MODULE,
1920         .release =      kcm_release,
1921         .bind =         sock_no_bind,
1922         .connect =      sock_no_connect,
1923         .socketpair =   sock_no_socketpair,
1924         .accept =       sock_no_accept,
1925         .getname =      sock_no_getname,
1926         .poll =         datagram_poll,
1927         .ioctl =        kcm_ioctl,
1928         .listen =       sock_no_listen,
1929         .shutdown =     sock_no_shutdown,
1930         .setsockopt =   kcm_setsockopt,
1931         .getsockopt =   kcm_getsockopt,
1932         .sendmsg =      kcm_sendmsg,
1933         .recvmsg =      kcm_recvmsg,
1934         .mmap =         sock_no_mmap,
1935         .sendpage =     kcm_sendpage,
1936         .splice_read =  kcm_splice_read,
1937 };
1938 
1939 /* Create proto operation for kcm sockets */
1940 static int kcm_create(struct net *net, struct socket *sock,
1941                       int protocol, int kern)
1942 {
1943         struct kcm_net *knet = net_generic(net, kcm_net_id);
1944         struct sock *sk;
1945         struct kcm_mux *mux;
1946 
1947         switch (sock->type) {
1948         case SOCK_DGRAM:
1949                 sock->ops = &kcm_dgram_ops;
1950                 break;
1951         case SOCK_SEQPACKET:
1952                 sock->ops = &kcm_seqpacket_ops;
1953                 break;
1954         default:
1955                 return -ESOCKTNOSUPPORT;
1956         }
1957 
1958         if (protocol != KCMPROTO_CONNECTED)
1959                 return -EPROTONOSUPPORT;
1960 
1961         sk = sk_alloc(net, PF_KCM, GFP_KERNEL, &kcm_proto, kern);
1962         if (!sk)
1963                 return -ENOMEM;
1964 
1965         /* Allocate a kcm mux, shared between KCM sockets */
1966         mux = kmem_cache_zalloc(kcm_muxp, GFP_KERNEL);
1967         if (!mux) {
1968                 sk_free(sk);
1969                 return -ENOMEM;
1970         }
1971 
1972         spin_lock_init(&mux->lock);
1973         spin_lock_init(&mux->rx_lock);
1974         INIT_LIST_HEAD(&mux->kcm_socks);
1975         INIT_LIST_HEAD(&mux->kcm_rx_waiters);
1976         INIT_LIST_HEAD(&mux->kcm_tx_waiters);
1977 
1978         INIT_LIST_HEAD(&mux->psocks);
1979         INIT_LIST_HEAD(&mux->psocks_ready);
1980         INIT_LIST_HEAD(&mux->psocks_avail);
1981 
1982         mux->knet = knet;
1983 
1984         /* Add new MUX to list */
1985         mutex_lock(&knet->mutex);
1986         list_add_rcu(&mux->kcm_mux_list, &knet->mux_list);
1987         knet->count++;
1988         mutex_unlock(&knet->mutex);
1989 
1990         skb_queue_head_init(&mux->rx_hold_queue);
1991 
1992         /* Init KCM socket */
1993         sock_init_data(sock, sk);
1994         init_kcm_sock(kcm_sk(sk), mux);
1995 
1996         return 0;
1997 }
1998 
1999 static const struct net_proto_family kcm_family_ops = {
2000         .family = PF_KCM,
2001         .create = kcm_create,
2002         .owner  = THIS_MODULE,
2003 };
2004 
2005 static __net_init int kcm_init_net(struct net *net)
2006 {
2007         struct kcm_net *knet = net_generic(net, kcm_net_id);
2008 
2009         INIT_LIST_HEAD_RCU(&knet->mux_list);
2010         mutex_init(&knet->mutex);
2011 
2012         return 0;
2013 }
2014 
2015 static __net_exit void kcm_exit_net(struct net *net)
2016 {
2017         struct kcm_net *knet = net_generic(net, kcm_net_id);
2018 
2019         /* All KCM sockets should be closed at this point, which should mean
2020          * that all multiplexors and psocks have been destroyed.
2021          */
2022         WARN_ON(!list_empty(&knet->mux_list));
2023 }
2024 
2025 static struct pernet_operations kcm_net_ops = {
2026         .init = kcm_init_net,
2027         .exit = kcm_exit_net,
2028         .id   = &kcm_net_id,
2029         .size = sizeof(struct kcm_net),
2030 };
2031 
2032 static int __init kcm_init(void)
2033 {
2034         int err = -ENOMEM;
2035 
2036         kcm_muxp = kmem_cache_create("kcm_mux_cache",
2037                                      sizeof(struct kcm_mux), 0,
2038                                      SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
2039         if (!kcm_muxp)
2040                 goto fail;
2041 
2042         kcm_psockp = kmem_cache_create("kcm_psock_cache",
2043                                        sizeof(struct kcm_psock), 0,
2044                                         SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
2045         if (!kcm_psockp)
2046                 goto fail;
2047 
2048         kcm_wq = create_singlethread_workqueue("kkcmd");
2049         if (!kcm_wq)
2050                 goto fail;
2051 
2052         err = proto_register(&kcm_proto, 1);
2053         if (err)
2054                 goto fail;
2055 
2056         err = sock_register(&kcm_family_ops);
2057         if (err)
2058                 goto sock_register_fail;
2059 
2060         err = register_pernet_device(&kcm_net_ops);
2061         if (err)
2062                 goto net_ops_fail;
2063 
2064         err = kcm_proc_init();
2065         if (err)
2066                 goto proc_init_fail;
2067 
2068         return 0;
2069 
2070 proc_init_fail:
2071         unregister_pernet_device(&kcm_net_ops);
2072 
2073 net_ops_fail:
2074         sock_unregister(PF_KCM);
2075 
2076 sock_register_fail:
2077         proto_unregister(&kcm_proto);
2078 
2079 fail:
2080         kmem_cache_destroy(kcm_muxp);
2081         kmem_cache_destroy(kcm_psockp);
2082 
2083         if (kcm_wq)
2084                 destroy_workqueue(kcm_wq);
2085 
2086         return err;
2087 }
2088 
2089 static void __exit kcm_exit(void)
2090 {
2091         kcm_proc_exit();
2092         unregister_pernet_device(&kcm_net_ops);
2093         sock_unregister(PF_KCM);
2094         proto_unregister(&kcm_proto);
2095         destroy_workqueue(kcm_wq);
2096 
2097         kmem_cache_destroy(kcm_muxp);
2098         kmem_cache_destroy(kcm_psockp);
2099 }
2100 
2101 module_init(kcm_init);
2102 module_exit(kcm_exit);
2103 
2104 MODULE_LICENSE("GPL");
2105 MODULE_ALIAS_NETPROTO(PF_KCM);
2106 
2107 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp