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1// SPDX-License-Identifier: GPL-2.0-only
2/******************************************************************************
3*******************************************************************************
4**
5** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
6** Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved.
7**
8**
9*******************************************************************************
10******************************************************************************/
11
12/*
13 * lowcomms.c
14 *
15 * This is the "low-level" comms layer.
16 *
17 * It is responsible for sending/receiving messages
18 * from other nodes in the cluster.
19 *
20 * Cluster nodes are referred to by their nodeids. nodeids are
21 * simply 32 bit numbers to the locking module - if they need to
22 * be expanded for the cluster infrastructure then that is its
23 * responsibility. It is this layer's
24 * responsibility to resolve these into IP address or
25 * whatever it needs for inter-node communication.
26 *
27 * The comms level is two kernel threads that deal mainly with
28 * the receiving of messages from other nodes and passing them
29 * up to the mid-level comms layer (which understands the
30 * message format) for execution by the locking core, and
31 * a send thread which does all the setting up of connections
32 * to remote nodes and the sending of data. Threads are not allowed
33 * to send their own data because it may cause them to wait in times
34 * of high load. Also, this way, the sending thread can collect together
35 * messages bound for one node and send them in one block.
36 *
37 * lowcomms will choose to use either TCP or SCTP as its transport layer
38 * depending on the configuration variable 'protocol'. This should be set
39 * to 0 (default) for TCP or 1 for SCTP. It should be configured using a
40 * cluster-wide mechanism as it must be the same on all nodes of the cluster
41 * for the DLM to function.
42 *
43 */
44
45#include <asm/ioctls.h>
46#include <net/sock.h>
47#include <net/tcp.h>
48#include <linux/pagemap.h>
49#include <linux/file.h>
50#include <linux/mutex.h>
51#include <linux/sctp.h>
52#include <linux/slab.h>
53#include <net/sctp/sctp.h>
54#include <net/ipv6.h>
55
56#include "dlm_internal.h"
57#include "lowcomms.h"
58#include "midcomms.h"
59#include "config.h"
60
61#define NEEDED_RMEM (4*1024*1024)
62#define CONN_HASH_SIZE 32
63
64/* Number of messages to send before rescheduling */
65#define MAX_SEND_MSG_COUNT 25
66
67struct cbuf {
68 unsigned int base;
69 unsigned int len;
70 unsigned int mask;
71};
72
73static void cbuf_add(struct cbuf *cb, int n)
74{
75 cb->len += n;
76}
77
78static int cbuf_data(struct cbuf *cb)
79{
80 return ((cb->base + cb->len) & cb->mask);
81}
82
83static void cbuf_init(struct cbuf *cb, int size)
84{
85 cb->base = cb->len = 0;
86 cb->mask = size-1;
87}
88
89static void cbuf_eat(struct cbuf *cb, int n)
90{
91 cb->len -= n;
92 cb->base += n;
93 cb->base &= cb->mask;
94}
95
96static bool cbuf_empty(struct cbuf *cb)
97{
98 return cb->len == 0;
99}
100
101struct connection {
102 struct socket *sock; /* NULL if not connected */
103 uint32_t nodeid; /* So we know who we are in the list */
104 struct mutex sock_mutex;
105 unsigned long flags;
106#define CF_READ_PENDING 1
107#define CF_WRITE_PENDING 2
108#define CF_INIT_PENDING 4
109#define CF_IS_OTHERCON 5
110#define CF_CLOSE 6
111#define CF_APP_LIMITED 7
112#define CF_CLOSING 8
113 struct list_head writequeue; /* List of outgoing writequeue_entries */
114 spinlock_t writequeue_lock;
115 int (*rx_action) (struct connection *); /* What to do when active */
116 void (*connect_action) (struct connection *); /* What to do to connect */
117 struct page *rx_page;
118 struct cbuf cb;
119 int retries;
120#define MAX_CONNECT_RETRIES 3
121 struct hlist_node list;
122 struct connection *othercon;
123 struct work_struct rwork; /* Receive workqueue */
124 struct work_struct swork; /* Send workqueue */
125};
126#define sock2con(x) ((struct connection *)(x)->sk_user_data)
127
128/* An entry waiting to be sent */
129struct writequeue_entry {
130 struct list_head list;
131 struct page *page;
132 int offset;
133 int len;
134 int end;
135 int users;
136 struct connection *con;
137};
138
139struct dlm_node_addr {
140 struct list_head list;
141 int nodeid;
142 int addr_count;
143 int curr_addr_index;
144 struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT];
145};
146
147static struct listen_sock_callbacks {
148 void (*sk_error_report)(struct sock *);
149 void (*sk_data_ready)(struct sock *);
150 void (*sk_state_change)(struct sock *);
151 void (*sk_write_space)(struct sock *);
152} listen_sock;
153
154static LIST_HEAD(dlm_node_addrs);
155static DEFINE_SPINLOCK(dlm_node_addrs_spin);
156
157static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT];
158static int dlm_local_count;
159static int dlm_allow_conn;
160
161/* Work queues */
162static struct workqueue_struct *recv_workqueue;
163static struct workqueue_struct *send_workqueue;
164
165static struct hlist_head connection_hash[CONN_HASH_SIZE];
166static DEFINE_MUTEX(connections_lock);
167static struct kmem_cache *con_cache;
168
169static void process_recv_sockets(struct work_struct *work);
170static void process_send_sockets(struct work_struct *work);
171
172
173/* This is deliberately very simple because most clusters have simple
174 sequential nodeids, so we should be able to go straight to a connection
175 struct in the array */
176static inline int nodeid_hash(int nodeid)
177{
178 return nodeid & (CONN_HASH_SIZE-1);
179}
180
181static struct connection *__find_con(int nodeid)
182{
183 int r;
184 struct connection *con;
185
186 r = nodeid_hash(nodeid);
187
188 hlist_for_each_entry(con, &connection_hash[r], list) {
189 if (con->nodeid == nodeid)
190 return con;
191 }
192 return NULL;
193}
194
195/*
196 * If 'allocation' is zero then we don't attempt to create a new
197 * connection structure for this node.
198 */
199static struct connection *__nodeid2con(int nodeid, gfp_t alloc)
200{
201 struct connection *con = NULL;
202 int r;
203
204 con = __find_con(nodeid);
205 if (con || !alloc)
206 return con;
207
208 con = kmem_cache_zalloc(con_cache, alloc);
209 if (!con)
210 return NULL;
211
212 r = nodeid_hash(nodeid);
213 hlist_add_head(&con->list, &connection_hash[r]);
214
215 con->nodeid = nodeid;
216 mutex_init(&con->sock_mutex);
217 INIT_LIST_HEAD(&con->writequeue);
218 spin_lock_init(&con->writequeue_lock);
219 INIT_WORK(&con->swork, process_send_sockets);
220 INIT_WORK(&con->rwork, process_recv_sockets);
221
222 /* Setup action pointers for child sockets */
223 if (con->nodeid) {
224 struct connection *zerocon = __find_con(0);
225
226 con->connect_action = zerocon->connect_action;
227 if (!con->rx_action)
228 con->rx_action = zerocon->rx_action;
229 }
230
231 return con;
232}
233
234/* Loop round all connections */
235static void foreach_conn(void (*conn_func)(struct connection *c))
236{
237 int i;
238 struct hlist_node *n;
239 struct connection *con;
240
241 for (i = 0; i < CONN_HASH_SIZE; i++) {
242 hlist_for_each_entry_safe(con, n, &connection_hash[i], list)
243 conn_func(con);
244 }
245}
246
247static struct connection *nodeid2con(int nodeid, gfp_t allocation)
248{
249 struct connection *con;
250
251 mutex_lock(&connections_lock);
252 con = __nodeid2con(nodeid, allocation);
253 mutex_unlock(&connections_lock);
254
255 return con;
256}
257
258static struct dlm_node_addr *find_node_addr(int nodeid)
259{
260 struct dlm_node_addr *na;
261
262 list_for_each_entry(na, &dlm_node_addrs, list) {
263 if (na->nodeid == nodeid)
264 return na;
265 }
266 return NULL;
267}
268
269static int addr_compare(struct sockaddr_storage *x, struct sockaddr_storage *y)
270{
271 switch (x->ss_family) {
272 case AF_INET: {
273 struct sockaddr_in *sinx = (struct sockaddr_in *)x;
274 struct sockaddr_in *siny = (struct sockaddr_in *)y;
275 if (sinx->sin_addr.s_addr != siny->sin_addr.s_addr)
276 return 0;
277 if (sinx->sin_port != siny->sin_port)
278 return 0;
279 break;
280 }
281 case AF_INET6: {
282 struct sockaddr_in6 *sinx = (struct sockaddr_in6 *)x;
283 struct sockaddr_in6 *siny = (struct sockaddr_in6 *)y;
284 if (!ipv6_addr_equal(&sinx->sin6_addr, &siny->sin6_addr))
285 return 0;
286 if (sinx->sin6_port != siny->sin6_port)
287 return 0;
288 break;
289 }
290 default:
291 return 0;
292 }
293 return 1;
294}
295
296static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out,
297 struct sockaddr *sa_out, bool try_new_addr)
298{
299 struct sockaddr_storage sas;
300 struct dlm_node_addr *na;
301
302 if (!dlm_local_count)
303 return -1;
304
305 spin_lock(&dlm_node_addrs_spin);
306 na = find_node_addr(nodeid);
307 if (na && na->addr_count) {
308 memcpy(&sas, na->addr[na->curr_addr_index],
309 sizeof(struct sockaddr_storage));
310
311 if (try_new_addr) {
312 na->curr_addr_index++;
313 if (na->curr_addr_index == na->addr_count)
314 na->curr_addr_index = 0;
315 }
316 }
317 spin_unlock(&dlm_node_addrs_spin);
318
319 if (!na)
320 return -EEXIST;
321
322 if (!na->addr_count)
323 return -ENOENT;
324
325 if (sas_out)
326 memcpy(sas_out, &sas, sizeof(struct sockaddr_storage));
327
328 if (!sa_out)
329 return 0;
330
331 if (dlm_local_addr[0]->ss_family == AF_INET) {
332 struct sockaddr_in *in4 = (struct sockaddr_in *) &sas;
333 struct sockaddr_in *ret4 = (struct sockaddr_in *) sa_out;
334 ret4->sin_addr.s_addr = in4->sin_addr.s_addr;
335 } else {
336 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &sas;
337 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) sa_out;
338 ret6->sin6_addr = in6->sin6_addr;
339 }
340
341 return 0;
342}
343
344static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid)
345{
346 struct dlm_node_addr *na;
347 int rv = -EEXIST;
348 int addr_i;
349
350 spin_lock(&dlm_node_addrs_spin);
351 list_for_each_entry(na, &dlm_node_addrs, list) {
352 if (!na->addr_count)
353 continue;
354
355 for (addr_i = 0; addr_i < na->addr_count; addr_i++) {
356 if (addr_compare(na->addr[addr_i], addr)) {
357 *nodeid = na->nodeid;
358 rv = 0;
359 goto unlock;
360 }
361 }
362 }
363unlock:
364 spin_unlock(&dlm_node_addrs_spin);
365 return rv;
366}
367
368int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len)
369{
370 struct sockaddr_storage *new_addr;
371 struct dlm_node_addr *new_node, *na;
372
373 new_node = kzalloc(sizeof(struct dlm_node_addr), GFP_NOFS);
374 if (!new_node)
375 return -ENOMEM;
376
377 new_addr = kzalloc(sizeof(struct sockaddr_storage), GFP_NOFS);
378 if (!new_addr) {
379 kfree(new_node);
380 return -ENOMEM;
381 }
382
383 memcpy(new_addr, addr, len);
384
385 spin_lock(&dlm_node_addrs_spin);
386 na = find_node_addr(nodeid);
387 if (!na) {
388 new_node->nodeid = nodeid;
389 new_node->addr[0] = new_addr;
390 new_node->addr_count = 1;
391 list_add(&new_node->list, &dlm_node_addrs);
392 spin_unlock(&dlm_node_addrs_spin);
393 return 0;
394 }
395
396 if (na->addr_count >= DLM_MAX_ADDR_COUNT) {
397 spin_unlock(&dlm_node_addrs_spin);
398 kfree(new_addr);
399 kfree(new_node);
400 return -ENOSPC;
401 }
402
403 na->addr[na->addr_count++] = new_addr;
404 spin_unlock(&dlm_node_addrs_spin);
405 kfree(new_node);
406 return 0;
407}
408
409/* Data available on socket or listen socket received a connect */
410static void lowcomms_data_ready(struct sock *sk)
411{
412 struct connection *con;
413
414 read_lock_bh(&sk->sk_callback_lock);
415 con = sock2con(sk);
416 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags))
417 queue_work(recv_workqueue, &con->rwork);
418 read_unlock_bh(&sk->sk_callback_lock);
419}
420
421static void lowcomms_write_space(struct sock *sk)
422{
423 struct connection *con;
424
425 read_lock_bh(&sk->sk_callback_lock);
426 con = sock2con(sk);
427 if (!con)
428 goto out;
429
430 clear_bit(SOCK_NOSPACE, &con->sock->flags);
431
432 if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) {
433 con->sock->sk->sk_write_pending--;
434 clear_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags);
435 }
436
437 queue_work(send_workqueue, &con->swork);
438out:
439 read_unlock_bh(&sk->sk_callback_lock);
440}
441
442static inline void lowcomms_connect_sock(struct connection *con)
443{
444 if (test_bit(CF_CLOSE, &con->flags))
445 return;
446 queue_work(send_workqueue, &con->swork);
447 cond_resched();
448}
449
450static void lowcomms_state_change(struct sock *sk)
451{
452 /* SCTP layer is not calling sk_data_ready when the connection
453 * is done, so we catch the signal through here. Also, it
454 * doesn't switch socket state when entering shutdown, so we
455 * skip the write in that case.
456 */
457 if (sk->sk_shutdown) {
458 if (sk->sk_shutdown == RCV_SHUTDOWN)
459 lowcomms_data_ready(sk);
460 } else if (sk->sk_state == TCP_ESTABLISHED) {
461 lowcomms_write_space(sk);
462 }
463}
464
465int dlm_lowcomms_connect_node(int nodeid)
466{
467 struct connection *con;
468
469 if (nodeid == dlm_our_nodeid())
470 return 0;
471
472 con = nodeid2con(nodeid, GFP_NOFS);
473 if (!con)
474 return -ENOMEM;
475 lowcomms_connect_sock(con);
476 return 0;
477}
478
479static void lowcomms_error_report(struct sock *sk)
480{
481 struct connection *con;
482 struct sockaddr_storage saddr;
483 void (*orig_report)(struct sock *) = NULL;
484
485 read_lock_bh(&sk->sk_callback_lock);
486 con = sock2con(sk);
487 if (con == NULL)
488 goto out;
489
490 orig_report = listen_sock.sk_error_report;
491 if (con->sock == NULL ||
492 kernel_getpeername(con->sock, (struct sockaddr *)&saddr) < 0) {
493 printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
494 "sending to node %d, port %d, "
495 "sk_err=%d/%d\n", dlm_our_nodeid(),
496 con->nodeid, dlm_config.ci_tcp_port,
497 sk->sk_err, sk->sk_err_soft);
498 } else if (saddr.ss_family == AF_INET) {
499 struct sockaddr_in *sin4 = (struct sockaddr_in *)&saddr;
500
501 printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
502 "sending to node %d at %pI4, port %d, "
503 "sk_err=%d/%d\n", dlm_our_nodeid(),
504 con->nodeid, &sin4->sin_addr.s_addr,
505 dlm_config.ci_tcp_port, sk->sk_err,
506 sk->sk_err_soft);
507 } else {
508 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&saddr;
509
510 printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
511 "sending to node %d at %u.%u.%u.%u, "
512 "port %d, sk_err=%d/%d\n", dlm_our_nodeid(),
513 con->nodeid, sin6->sin6_addr.s6_addr32[0],
514 sin6->sin6_addr.s6_addr32[1],
515 sin6->sin6_addr.s6_addr32[2],
516 sin6->sin6_addr.s6_addr32[3],
517 dlm_config.ci_tcp_port, sk->sk_err,
518 sk->sk_err_soft);
519 }
520out:
521 read_unlock_bh(&sk->sk_callback_lock);
522 if (orig_report)
523 orig_report(sk);
524}
525
526/* Note: sk_callback_lock must be locked before calling this function. */
527static void save_listen_callbacks(struct socket *sock)
528{
529 struct sock *sk = sock->sk;
530
531 listen_sock.sk_data_ready = sk->sk_data_ready;
532 listen_sock.sk_state_change = sk->sk_state_change;
533 listen_sock.sk_write_space = sk->sk_write_space;
534 listen_sock.sk_error_report = sk->sk_error_report;
535}
536
537static void restore_callbacks(struct socket *sock)
538{
539 struct sock *sk = sock->sk;
540
541 write_lock_bh(&sk->sk_callback_lock);
542 sk->sk_user_data = NULL;
543 sk->sk_data_ready = listen_sock.sk_data_ready;
544 sk->sk_state_change = listen_sock.sk_state_change;
545 sk->sk_write_space = listen_sock.sk_write_space;
546 sk->sk_error_report = listen_sock.sk_error_report;
547 write_unlock_bh(&sk->sk_callback_lock);
548}
549
550/* Make a socket active */
551static void add_sock(struct socket *sock, struct connection *con)
552{
553 struct sock *sk = sock->sk;
554
555 write_lock_bh(&sk->sk_callback_lock);
556 con->sock = sock;
557
558 sk->sk_user_data = con;
559 /* Install a data_ready callback */
560 sk->sk_data_ready = lowcomms_data_ready;
561 sk->sk_write_space = lowcomms_write_space;
562 sk->sk_state_change = lowcomms_state_change;
563 sk->sk_allocation = GFP_NOFS;
564 sk->sk_error_report = lowcomms_error_report;
565 write_unlock_bh(&sk->sk_callback_lock);
566}
567
568/* Add the port number to an IPv6 or 4 sockaddr and return the address
569 length */
570static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
571 int *addr_len)
572{
573 saddr->ss_family = dlm_local_addr[0]->ss_family;
574 if (saddr->ss_family == AF_INET) {
575 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
576 in4_addr->sin_port = cpu_to_be16(port);
577 *addr_len = sizeof(struct sockaddr_in);
578 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero));
579 } else {
580 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
581 in6_addr->sin6_port = cpu_to_be16(port);
582 *addr_len = sizeof(struct sockaddr_in6);
583 }
584 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len);
585}
586
587/* Close a remote connection and tidy up */
588static void close_connection(struct connection *con, bool and_other,
589 bool tx, bool rx)
590{
591 bool closing = test_and_set_bit(CF_CLOSING, &con->flags);
592
593 if (tx && !closing && cancel_work_sync(&con->swork)) {
594 log_print("canceled swork for node %d", con->nodeid);
595 clear_bit(CF_WRITE_PENDING, &con->flags);
596 }
597 if (rx && !closing && cancel_work_sync(&con->rwork)) {
598 log_print("canceled rwork for node %d", con->nodeid);
599 clear_bit(CF_READ_PENDING, &con->flags);
600 }
601
602 mutex_lock(&con->sock_mutex);
603 if (con->sock) {
604 restore_callbacks(con->sock);
605 sock_release(con->sock);
606 con->sock = NULL;
607 }
608 if (con->othercon && and_other) {
609 /* Will only re-enter once. */
610 close_connection(con->othercon, false, true, true);
611 }
612 if (con->rx_page) {
613 __free_page(con->rx_page);
614 con->rx_page = NULL;
615 }
616
617 con->retries = 0;
618 mutex_unlock(&con->sock_mutex);
619 clear_bit(CF_CLOSING, &con->flags);
620}
621
622/* Data received from remote end */
623static int receive_from_sock(struct connection *con)
624{
625 int ret = 0;
626 struct msghdr msg = {};
627 struct kvec iov[2];
628 unsigned len;
629 int r;
630 int call_again_soon = 0;
631 int nvec;
632
633 mutex_lock(&con->sock_mutex);
634
635 if (con->sock == NULL) {
636 ret = -EAGAIN;
637 goto out_close;
638 }
639 if (con->nodeid == 0) {
640 ret = -EINVAL;
641 goto out_close;
642 }
643
644 if (con->rx_page == NULL) {
645 /*
646 * This doesn't need to be atomic, but I think it should
647 * improve performance if it is.
648 */
649 con->rx_page = alloc_page(GFP_ATOMIC);
650 if (con->rx_page == NULL)
651 goto out_resched;
652 cbuf_init(&con->cb, PAGE_SIZE);
653 }
654
655 /*
656 * iov[0] is the bit of the circular buffer between the current end
657 * point (cb.base + cb.len) and the end of the buffer.
658 */
659 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb);
660 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb);
661 iov[1].iov_len = 0;
662 nvec = 1;
663
664 /*
665 * iov[1] is the bit of the circular buffer between the start of the
666 * buffer and the start of the currently used section (cb.base)
667 */
668 if (cbuf_data(&con->cb) >= con->cb.base) {
669 iov[0].iov_len = PAGE_SIZE - cbuf_data(&con->cb);
670 iov[1].iov_len = con->cb.base;
671 iov[1].iov_base = page_address(con->rx_page);
672 nvec = 2;
673 }
674 len = iov[0].iov_len + iov[1].iov_len;
675 iov_iter_kvec(&msg.msg_iter, READ, iov, nvec, len);
676
677 r = ret = sock_recvmsg(con->sock, &msg, MSG_DONTWAIT | MSG_NOSIGNAL);
678 if (ret <= 0)
679 goto out_close;
680 else if (ret == len)
681 call_again_soon = 1;
682
683 cbuf_add(&con->cb, ret);
684 ret = dlm_process_incoming_buffer(con->nodeid,
685 page_address(con->rx_page),
686 con->cb.base, con->cb.len,
687 PAGE_SIZE);
688 if (ret == -EBADMSG) {
689 log_print("lowcomms: addr=%p, base=%u, len=%u, read=%d",
690 page_address(con->rx_page), con->cb.base,
691 con->cb.len, r);
692 }
693 if (ret < 0)
694 goto out_close;
695 cbuf_eat(&con->cb, ret);
696
697 if (cbuf_empty(&con->cb) && !call_again_soon) {
698 __free_page(con->rx_page);
699 con->rx_page = NULL;
700 }
701
702 if (call_again_soon)
703 goto out_resched;
704 mutex_unlock(&con->sock_mutex);
705 return 0;
706
707out_resched:
708 if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
709 queue_work(recv_workqueue, &con->rwork);
710 mutex_unlock(&con->sock_mutex);
711 return -EAGAIN;
712
713out_close:
714 mutex_unlock(&con->sock_mutex);
715 if (ret != -EAGAIN) {
716 close_connection(con, true, true, false);
717 /* Reconnect when there is something to send */
718 }
719 /* Don't return success if we really got EOF */
720 if (ret == 0)
721 ret = -EAGAIN;
722
723 return ret;
724}
725
726/* Listening socket is busy, accept a connection */
727static int tcp_accept_from_sock(struct connection *con)
728{
729 int result;
730 struct sockaddr_storage peeraddr;
731 struct socket *newsock;
732 int len;
733 int nodeid;
734 struct connection *newcon;
735 struct connection *addcon;
736
737 mutex_lock(&connections_lock);
738 if (!dlm_allow_conn) {
739 mutex_unlock(&connections_lock);
740 return -1;
741 }
742 mutex_unlock(&connections_lock);
743
744 mutex_lock_nested(&con->sock_mutex, 0);
745
746 if (!con->sock) {
747 mutex_unlock(&con->sock_mutex);
748 return -ENOTCONN;
749 }
750
751 result = kernel_accept(con->sock, &newsock, O_NONBLOCK);
752 if (result < 0)
753 goto accept_err;
754
755 /* Get the connected socket's peer */
756 memset(&peeraddr, 0, sizeof(peeraddr));
757 len = newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 2);
758 if (len < 0) {
759 result = -ECONNABORTED;
760 goto accept_err;
761 }
762
763 /* Get the new node's NODEID */
764 make_sockaddr(&peeraddr, 0, &len);
765 if (addr_to_nodeid(&peeraddr, &nodeid)) {
766 unsigned char *b=(unsigned char *)&peeraddr;
767 log_print("connect from non cluster node");
768 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE,
769 b, sizeof(struct sockaddr_storage));
770 sock_release(newsock);
771 mutex_unlock(&con->sock_mutex);
772 return -1;
773 }
774
775 log_print("got connection from %d", nodeid);
776
777 /* Check to see if we already have a connection to this node. This
778 * could happen if the two nodes initiate a connection at roughly
779 * the same time and the connections cross on the wire.
780 * In this case we store the incoming one in "othercon"
781 */
782 newcon = nodeid2con(nodeid, GFP_NOFS);
783 if (!newcon) {
784 result = -ENOMEM;
785 goto accept_err;
786 }
787 mutex_lock_nested(&newcon->sock_mutex, 1);
788 if (newcon->sock) {
789 struct connection *othercon = newcon->othercon;
790
791 if (!othercon) {
792 othercon = kmem_cache_zalloc(con_cache, GFP_NOFS);
793 if (!othercon) {
794 log_print("failed to allocate incoming socket");
795 mutex_unlock(&newcon->sock_mutex);
796 result = -ENOMEM;
797 goto accept_err;
798 }
799 othercon->nodeid = nodeid;
800 othercon->rx_action = receive_from_sock;
801 mutex_init(&othercon->sock_mutex);
802 INIT_LIST_HEAD(&othercon->writequeue);
803 spin_lock_init(&othercon->writequeue_lock);
804 INIT_WORK(&othercon->swork, process_send_sockets);
805 INIT_WORK(&othercon->rwork, process_recv_sockets);
806 set_bit(CF_IS_OTHERCON, &othercon->flags);
807 }
808 mutex_lock_nested(&othercon->sock_mutex, 2);
809 if (!othercon->sock) {
810 newcon->othercon = othercon;
811 add_sock(newsock, othercon);
812 addcon = othercon;
813 mutex_unlock(&othercon->sock_mutex);
814 }
815 else {
816 printk("Extra connection from node %d attempted\n", nodeid);
817 result = -EAGAIN;
818 mutex_unlock(&othercon->sock_mutex);
819 mutex_unlock(&newcon->sock_mutex);
820 goto accept_err;
821 }
822 }
823 else {
824 newcon->rx_action = receive_from_sock;
825 /* accept copies the sk after we've saved the callbacks, so we
826 don't want to save them a second time or comm errors will
827 result in calling sk_error_report recursively. */
828 add_sock(newsock, newcon);
829 addcon = newcon;
830 }
831
832 mutex_unlock(&newcon->sock_mutex);
833
834 /*
835 * Add it to the active queue in case we got data
836 * between processing the accept adding the socket
837 * to the read_sockets list
838 */
839 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
840 queue_work(recv_workqueue, &addcon->rwork);
841 mutex_unlock(&con->sock_mutex);
842
843 return 0;
844
845accept_err:
846 mutex_unlock(&con->sock_mutex);
847 if (newsock)
848 sock_release(newsock);
849
850 if (result != -EAGAIN)
851 log_print("error accepting connection from node: %d", result);
852 return result;
853}
854
855static int sctp_accept_from_sock(struct connection *con)
856{
857 /* Check that the new node is in the lockspace */
858 struct sctp_prim prim;
859 int nodeid;
860 int prim_len, ret;
861 int addr_len;
862 struct connection *newcon;
863 struct connection *addcon;
864 struct socket *newsock;
865
866 mutex_lock(&connections_lock);
867 if (!dlm_allow_conn) {
868 mutex_unlock(&connections_lock);
869 return -1;
870 }
871 mutex_unlock(&connections_lock);
872
873 mutex_lock_nested(&con->sock_mutex, 0);
874
875 ret = kernel_accept(con->sock, &newsock, O_NONBLOCK);
876 if (ret < 0)
877 goto accept_err;
878
879 memset(&prim, 0, sizeof(struct sctp_prim));
880 prim_len = sizeof(struct sctp_prim);
881
882 ret = kernel_getsockopt(newsock, IPPROTO_SCTP, SCTP_PRIMARY_ADDR,
883 (char *)&prim, &prim_len);
884 if (ret < 0) {
885 log_print("getsockopt/sctp_primary_addr failed: %d", ret);
886 goto accept_err;
887 }
888
889 make_sockaddr(&prim.ssp_addr, 0, &addr_len);
890 ret = addr_to_nodeid(&prim.ssp_addr, &nodeid);
891 if (ret) {
892 unsigned char *b = (unsigned char *)&prim.ssp_addr;
893
894 log_print("reject connect from unknown addr");
895 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE,
896 b, sizeof(struct sockaddr_storage));
897 goto accept_err;
898 }
899
900 newcon = nodeid2con(nodeid, GFP_NOFS);
901 if (!newcon) {
902 ret = -ENOMEM;
903 goto accept_err;
904 }
905
906 mutex_lock_nested(&newcon->sock_mutex, 1);
907
908 if (newcon->sock) {
909 struct connection *othercon = newcon->othercon;
910
911 if (!othercon) {
912 othercon = kmem_cache_zalloc(con_cache, GFP_NOFS);
913 if (!othercon) {
914 log_print("failed to allocate incoming socket");
915 mutex_unlock(&newcon->sock_mutex);
916 ret = -ENOMEM;
917 goto accept_err;
918 }
919 othercon->nodeid = nodeid;
920 othercon->rx_action = receive_from_sock;
921 mutex_init(&othercon->sock_mutex);
922 INIT_LIST_HEAD(&othercon->writequeue);
923 spin_lock_init(&othercon->writequeue_lock);
924 INIT_WORK(&othercon->swork, process_send_sockets);
925 INIT_WORK(&othercon->rwork, process_recv_sockets);
926 set_bit(CF_IS_OTHERCON, &othercon->flags);
927 }
928 mutex_lock_nested(&othercon->sock_mutex, 2);
929 if (!othercon->sock) {
930 newcon->othercon = othercon;
931 add_sock(newsock, othercon);
932 addcon = othercon;
933 mutex_unlock(&othercon->sock_mutex);
934 } else {
935 printk("Extra connection from node %d attempted\n", nodeid);
936 ret = -EAGAIN;
937 mutex_unlock(&othercon->sock_mutex);
938 mutex_unlock(&newcon->sock_mutex);
939 goto accept_err;
940 }
941 } else {
942 newcon->rx_action = receive_from_sock;
943 add_sock(newsock, newcon);
944 addcon = newcon;
945 }
946
947 log_print("connected to %d", nodeid);
948
949 mutex_unlock(&newcon->sock_mutex);
950
951 /*
952 * Add it to the active queue in case we got data
953 * between processing the accept adding the socket
954 * to the read_sockets list
955 */
956 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
957 queue_work(recv_workqueue, &addcon->rwork);
958 mutex_unlock(&con->sock_mutex);
959
960 return 0;
961
962accept_err:
963 mutex_unlock(&con->sock_mutex);
964 if (newsock)
965 sock_release(newsock);
966 if (ret != -EAGAIN)
967 log_print("error accepting connection from node: %d", ret);
968
969 return ret;
970}
971
972static void free_entry(struct writequeue_entry *e)
973{
974 __free_page(e->page);
975 kfree(e);
976}
977
978/*
979 * writequeue_entry_complete - try to delete and free write queue entry
980 * @e: write queue entry to try to delete
981 * @completed: bytes completed
982 *
983 * writequeue_lock must be held.
984 */
985static void writequeue_entry_complete(struct writequeue_entry *e, int completed)
986{
987 e->offset += completed;
988 e->len -= completed;
989
990 if (e->len == 0 && e->users == 0) {
991 list_del(&e->list);
992 free_entry(e);
993 }
994}
995
996/*
997 * sctp_bind_addrs - bind a SCTP socket to all our addresses
998 */
999static int sctp_bind_addrs(struct connection *con, uint16_t port)
1000{
1001 struct sockaddr_storage localaddr;
1002 int i, addr_len, result = 0;
1003
1004 for (i = 0; i < dlm_local_count; i++) {
1005 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr));
1006 make_sockaddr(&localaddr, port, &addr_len);
1007
1008 if (!i)
1009 result = kernel_bind(con->sock,
1010 (struct sockaddr *)&localaddr,
1011 addr_len);
1012 else
1013 result = kernel_setsockopt(con->sock, SOL_SCTP,
1014 SCTP_SOCKOPT_BINDX_ADD,
1015 (char *)&localaddr, addr_len);
1016
1017 if (result < 0) {
1018 log_print("Can't bind to %d addr number %d, %d.\n",
1019 port, i + 1, result);
1020 break;
1021 }
1022 }
1023 return result;
1024}
1025
1026/* Initiate an SCTP association.
1027 This is a special case of send_to_sock() in that we don't yet have a
1028 peeled-off socket for this association, so we use the listening socket
1029 and add the primary IP address of the remote node.
1030 */
1031static void sctp_connect_to_sock(struct connection *con)
1032{
1033 struct sockaddr_storage daddr;
1034 int one = 1;
1035 int result;
1036 int addr_len;
1037 struct socket *sock;
1038 struct timeval tv = { .tv_sec = 5, .tv_usec = 0 };
1039
1040 if (con->nodeid == 0) {
1041 log_print("attempt to connect sock 0 foiled");
1042 return;
1043 }
1044
1045 mutex_lock(&con->sock_mutex);
1046
1047 /* Some odd races can cause double-connects, ignore them */
1048 if (con->retries++ > MAX_CONNECT_RETRIES)
1049 goto out;
1050
1051 if (con->sock) {
1052 log_print("node %d already connected.", con->nodeid);
1053 goto out;
1054 }
1055
1056 memset(&daddr, 0, sizeof(daddr));
1057 result = nodeid_to_addr(con->nodeid, &daddr, NULL, true);
1058 if (result < 0) {
1059 log_print("no address for nodeid %d", con->nodeid);
1060 goto out;
1061 }
1062
1063 /* Create a socket to communicate with */
1064 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
1065 SOCK_STREAM, IPPROTO_SCTP, &sock);
1066 if (result < 0)
1067 goto socket_err;
1068
1069 con->rx_action = receive_from_sock;
1070 con->connect_action = sctp_connect_to_sock;
1071 add_sock(sock, con);
1072
1073 /* Bind to all addresses. */
1074 if (sctp_bind_addrs(con, 0))
1075 goto bind_err;
1076
1077 make_sockaddr(&daddr, dlm_config.ci_tcp_port, &addr_len);
1078
1079 log_print("connecting to %d", con->nodeid);
1080
1081 /* Turn off Nagle's algorithm */
1082 kernel_setsockopt(sock, SOL_SCTP, SCTP_NODELAY, (char *)&one,
1083 sizeof(one));
1084
1085 /*
1086 * Make sock->ops->connect() function return in specified time,
1087 * since O_NONBLOCK argument in connect() function does not work here,
1088 * then, we should restore the default value of this attribute.
1089 */
1090 kernel_setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO_OLD, (char *)&tv,
1091 sizeof(tv));
1092 result = sock->ops->connect(sock, (struct sockaddr *)&daddr, addr_len,
1093 0);
1094 memset(&tv, 0, sizeof(tv));
1095 kernel_setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO_OLD, (char *)&tv,
1096 sizeof(tv));
1097
1098 if (result == -EINPROGRESS)
1099 result = 0;
1100 if (result == 0)
1101 goto out;
1102
1103bind_err:
1104 con->sock = NULL;
1105 sock_release(sock);
1106
1107socket_err:
1108 /*
1109 * Some errors are fatal and this list might need adjusting. For other
1110 * errors we try again until the max number of retries is reached.
1111 */
1112 if (result != -EHOSTUNREACH &&
1113 result != -ENETUNREACH &&
1114 result != -ENETDOWN &&
1115 result != -EINVAL &&
1116 result != -EPROTONOSUPPORT) {
1117 log_print("connect %d try %d error %d", con->nodeid,
1118 con->retries, result);
1119 mutex_unlock(&con->sock_mutex);
1120 msleep(1000);
1121 lowcomms_connect_sock(con);
1122 return;
1123 }
1124
1125out:
1126 mutex_unlock(&con->sock_mutex);
1127}
1128
1129/* Connect a new socket to its peer */
1130static void tcp_connect_to_sock(struct connection *con)
1131{
1132 struct sockaddr_storage saddr, src_addr;
1133 int addr_len;
1134 struct socket *sock = NULL;
1135 int one = 1;
1136 int result;
1137
1138 if (con->nodeid == 0) {
1139 log_print("attempt to connect sock 0 foiled");
1140 return;
1141 }
1142
1143 mutex_lock(&con->sock_mutex);
1144 if (con->retries++ > MAX_CONNECT_RETRIES)
1145 goto out;
1146
1147 /* Some odd races can cause double-connects, ignore them */
1148 if (con->sock)
1149 goto out;
1150
1151 /* Create a socket to communicate with */
1152 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
1153 SOCK_STREAM, IPPROTO_TCP, &sock);
1154 if (result < 0)
1155 goto out_err;
1156
1157 memset(&saddr, 0, sizeof(saddr));
1158 result = nodeid_to_addr(con->nodeid, &saddr, NULL, false);
1159 if (result < 0) {
1160 log_print("no address for nodeid %d", con->nodeid);
1161 goto out_err;
1162 }
1163
1164 con->rx_action = receive_from_sock;
1165 con->connect_action = tcp_connect_to_sock;
1166 add_sock(sock, con);
1167
1168 /* Bind to our cluster-known address connecting to avoid
1169 routing problems */
1170 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr));
1171 make_sockaddr(&src_addr, 0, &addr_len);
1172 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr,
1173 addr_len);
1174 if (result < 0) {
1175 log_print("could not bind for connect: %d", result);
1176 /* This *may* not indicate a critical error */
1177 }
1178
1179 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len);
1180
1181 log_print("connecting to %d", con->nodeid);
1182
1183 /* Turn off Nagle's algorithm */
1184 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one,
1185 sizeof(one));
1186
1187 result = sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len,
1188 O_NONBLOCK);
1189 if (result == -EINPROGRESS)
1190 result = 0;
1191 if (result == 0)
1192 goto out;
1193
1194out_err:
1195 if (con->sock) {
1196 sock_release(con->sock);
1197 con->sock = NULL;
1198 } else if (sock) {
1199 sock_release(sock);
1200 }
1201 /*
1202 * Some errors are fatal and this list might need adjusting. For other
1203 * errors we try again until the max number of retries is reached.
1204 */
1205 if (result != -EHOSTUNREACH &&
1206 result != -ENETUNREACH &&
1207 result != -ENETDOWN &&
1208 result != -EINVAL &&
1209 result != -EPROTONOSUPPORT) {
1210 log_print("connect %d try %d error %d", con->nodeid,
1211 con->retries, result);
1212 mutex_unlock(&con->sock_mutex);
1213 msleep(1000);
1214 lowcomms_connect_sock(con);
1215 return;
1216 }
1217out:
1218 mutex_unlock(&con->sock_mutex);
1219 return;
1220}
1221
1222static struct socket *tcp_create_listen_sock(struct connection *con,
1223 struct sockaddr_storage *saddr)
1224{
1225 struct socket *sock = NULL;
1226 int result = 0;
1227 int one = 1;
1228 int addr_len;
1229
1230 if (dlm_local_addr[0]->ss_family == AF_INET)
1231 addr_len = sizeof(struct sockaddr_in);
1232 else
1233 addr_len = sizeof(struct sockaddr_in6);
1234
1235 /* Create a socket to communicate with */
1236 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
1237 SOCK_STREAM, IPPROTO_TCP, &sock);
1238 if (result < 0) {
1239 log_print("Can't create listening comms socket");
1240 goto create_out;
1241 }
1242
1243 /* Turn off Nagle's algorithm */
1244 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one,
1245 sizeof(one));
1246
1247 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
1248 (char *)&one, sizeof(one));
1249
1250 if (result < 0) {
1251 log_print("Failed to set SO_REUSEADDR on socket: %d", result);
1252 }
1253 write_lock_bh(&sock->sk->sk_callback_lock);
1254 sock->sk->sk_user_data = con;
1255 save_listen_callbacks(sock);
1256 con->rx_action = tcp_accept_from_sock;
1257 con->connect_action = tcp_connect_to_sock;
1258 write_unlock_bh(&sock->sk->sk_callback_lock);
1259
1260 /* Bind to our port */
1261 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len);
1262 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len);
1263 if (result < 0) {
1264 log_print("Can't bind to port %d", dlm_config.ci_tcp_port);
1265 sock_release(sock);
1266 sock = NULL;
1267 con->sock = NULL;
1268 goto create_out;
1269 }
1270 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
1271 (char *)&one, sizeof(one));
1272 if (result < 0) {
1273 log_print("Set keepalive failed: %d", result);
1274 }
1275
1276 result = sock->ops->listen(sock, 5);
1277 if (result < 0) {
1278 log_print("Can't listen on port %d", dlm_config.ci_tcp_port);
1279 sock_release(sock);
1280 sock = NULL;
1281 goto create_out;
1282 }
1283
1284create_out:
1285 return sock;
1286}
1287
1288/* Get local addresses */
1289static void init_local(void)
1290{
1291 struct sockaddr_storage sas, *addr;
1292 int i;
1293
1294 dlm_local_count = 0;
1295 for (i = 0; i < DLM_MAX_ADDR_COUNT; i++) {
1296 if (dlm_our_addr(&sas, i))
1297 break;
1298
1299 addr = kmemdup(&sas, sizeof(*addr), GFP_NOFS);
1300 if (!addr)
1301 break;
1302 dlm_local_addr[dlm_local_count++] = addr;
1303 }
1304}
1305
1306/* Initialise SCTP socket and bind to all interfaces */
1307static int sctp_listen_for_all(void)
1308{
1309 struct socket *sock = NULL;
1310 int result = -EINVAL;
1311 struct connection *con = nodeid2con(0, GFP_NOFS);
1312 int bufsize = NEEDED_RMEM;
1313 int one = 1;
1314
1315 if (!con)
1316 return -ENOMEM;
1317
1318 log_print("Using SCTP for communications");
1319
1320 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
1321 SOCK_STREAM, IPPROTO_SCTP, &sock);
1322 if (result < 0) {
1323 log_print("Can't create comms socket, check SCTP is loaded");
1324 goto out;
1325 }
1326
1327 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE,
1328 (char *)&bufsize, sizeof(bufsize));
1329 if (result)
1330 log_print("Error increasing buffer space on socket %d", result);
1331
1332 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_NODELAY, (char *)&one,
1333 sizeof(one));
1334 if (result < 0)
1335 log_print("Could not set SCTP NODELAY error %d\n", result);
1336
1337 write_lock_bh(&sock->sk->sk_callback_lock);
1338 /* Init con struct */
1339 sock->sk->sk_user_data = con;
1340 save_listen_callbacks(sock);
1341 con->sock = sock;
1342 con->sock->sk->sk_data_ready = lowcomms_data_ready;
1343 con->rx_action = sctp_accept_from_sock;
1344 con->connect_action = sctp_connect_to_sock;
1345
1346 write_unlock_bh(&sock->sk->sk_callback_lock);
1347
1348 /* Bind to all addresses. */
1349 if (sctp_bind_addrs(con, dlm_config.ci_tcp_port))
1350 goto create_delsock;
1351
1352 result = sock->ops->listen(sock, 5);
1353 if (result < 0) {
1354 log_print("Can't set socket listening");
1355 goto create_delsock;
1356 }
1357
1358 return 0;
1359
1360create_delsock:
1361 sock_release(sock);
1362 con->sock = NULL;
1363out:
1364 return result;
1365}
1366
1367static int tcp_listen_for_all(void)
1368{
1369 struct socket *sock = NULL;
1370 struct connection *con = nodeid2con(0, GFP_NOFS);
1371 int result = -EINVAL;
1372
1373 if (!con)
1374 return -ENOMEM;
1375
1376 /* We don't support multi-homed hosts */
1377 if (dlm_local_addr[1] != NULL) {
1378 log_print("TCP protocol can't handle multi-homed hosts, "
1379 "try SCTP");
1380 return -EINVAL;
1381 }
1382
1383 log_print("Using TCP for communications");
1384
1385 sock = tcp_create_listen_sock(con, dlm_local_addr[0]);
1386 if (sock) {
1387 add_sock(sock, con);
1388 result = 0;
1389 }
1390 else {
1391 result = -EADDRINUSE;
1392 }
1393
1394 return result;
1395}
1396
1397
1398
1399static struct writequeue_entry *new_writequeue_entry(struct connection *con,
1400 gfp_t allocation)
1401{
1402 struct writequeue_entry *entry;
1403
1404 entry = kmalloc(sizeof(struct writequeue_entry), allocation);
1405 if (!entry)
1406 return NULL;
1407
1408 entry->page = alloc_page(allocation);
1409 if (!entry->page) {
1410 kfree(entry);
1411 return NULL;
1412 }
1413
1414 entry->offset = 0;
1415 entry->len = 0;
1416 entry->end = 0;
1417 entry->users = 0;
1418 entry->con = con;
1419
1420 return entry;
1421}
1422
1423void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)
1424{
1425 struct connection *con;
1426 struct writequeue_entry *e;
1427 int offset = 0;
1428
1429 con = nodeid2con(nodeid, allocation);
1430 if (!con)
1431 return NULL;
1432
1433 spin_lock(&con->writequeue_lock);
1434 e = list_entry(con->writequeue.prev, struct writequeue_entry, list);
1435 if ((&e->list == &con->writequeue) ||
1436 (PAGE_SIZE - e->end < len)) {
1437 e = NULL;
1438 } else {
1439 offset = e->end;
1440 e->end += len;
1441 e->users++;
1442 }
1443 spin_unlock(&con->writequeue_lock);
1444
1445 if (e) {
1446 got_one:
1447 *ppc = page_address(e->page) + offset;
1448 return e;
1449 }
1450
1451 e = new_writequeue_entry(con, allocation);
1452 if (e) {
1453 spin_lock(&con->writequeue_lock);
1454 offset = e->end;
1455 e->end += len;
1456 e->users++;
1457 list_add_tail(&e->list, &con->writequeue);
1458 spin_unlock(&con->writequeue_lock);
1459 goto got_one;
1460 }
1461 return NULL;
1462}
1463
1464void dlm_lowcomms_commit_buffer(void *mh)
1465{
1466 struct writequeue_entry *e = (struct writequeue_entry *)mh;
1467 struct connection *con = e->con;
1468 int users;
1469
1470 spin_lock(&con->writequeue_lock);
1471 users = --e->users;
1472 if (users)
1473 goto out;
1474 e->len = e->end - e->offset;
1475 spin_unlock(&con->writequeue_lock);
1476
1477 queue_work(send_workqueue, &con->swork);
1478 return;
1479
1480out:
1481 spin_unlock(&con->writequeue_lock);
1482 return;
1483}
1484
1485/* Send a message */
1486static void send_to_sock(struct connection *con)
1487{
1488 int ret = 0;
1489 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
1490 struct writequeue_entry *e;
1491 int len, offset;
1492 int count = 0;
1493
1494 mutex_lock(&con->sock_mutex);
1495 if (con->sock == NULL)
1496 goto out_connect;
1497
1498 spin_lock(&con->writequeue_lock);
1499 for (;;) {
1500 e = list_entry(con->writequeue.next, struct writequeue_entry,
1501 list);
1502 if ((struct list_head *) e == &con->writequeue)
1503 break;
1504
1505 len = e->len;
1506 offset = e->offset;
1507 BUG_ON(len == 0 && e->users == 0);
1508 spin_unlock(&con->writequeue_lock);
1509
1510 ret = 0;
1511 if (len) {
1512 ret = kernel_sendpage(con->sock, e->page, offset, len,
1513 msg_flags);
1514 if (ret == -EAGAIN || ret == 0) {
1515 if (ret == -EAGAIN &&
1516 test_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags) &&
1517 !test_and_set_bit(CF_APP_LIMITED, &con->flags)) {
1518 /* Notify TCP that we're limited by the
1519 * application window size.
1520 */
1521 set_bit(SOCK_NOSPACE, &con->sock->flags);
1522 con->sock->sk->sk_write_pending++;
1523 }
1524 cond_resched();
1525 goto out;
1526 } else if (ret < 0)
1527 goto send_error;
1528 }
1529
1530 /* Don't starve people filling buffers */
1531 if (++count >= MAX_SEND_MSG_COUNT) {
1532 cond_resched();
1533 count = 0;
1534 }
1535
1536 spin_lock(&con->writequeue_lock);
1537 writequeue_entry_complete(e, ret);
1538 }
1539 spin_unlock(&con->writequeue_lock);
1540out:
1541 mutex_unlock(&con->sock_mutex);
1542 return;
1543
1544send_error:
1545 mutex_unlock(&con->sock_mutex);
1546 close_connection(con, true, false, true);
1547 /* Requeue the send work. When the work daemon runs again, it will try
1548 a new connection, then call this function again. */
1549 queue_work(send_workqueue, &con->swork);
1550 return;
1551
1552out_connect:
1553 mutex_unlock(&con->sock_mutex);
1554 queue_work(send_workqueue, &con->swork);
1555 cond_resched();
1556}
1557
1558static void clean_one_writequeue(struct connection *con)
1559{
1560 struct writequeue_entry *e, *safe;
1561
1562 spin_lock(&con->writequeue_lock);
1563 list_for_each_entry_safe(e, safe, &con->writequeue, list) {
1564 list_del(&e->list);
1565 free_entry(e);
1566 }
1567 spin_unlock(&con->writequeue_lock);
1568}
1569
1570/* Called from recovery when it knows that a node has
1571 left the cluster */
1572int dlm_lowcomms_close(int nodeid)
1573{
1574 struct connection *con;
1575 struct dlm_node_addr *na;
1576
1577 log_print("closing connection to node %d", nodeid);
1578 con = nodeid2con(nodeid, 0);
1579 if (con) {
1580 set_bit(CF_CLOSE, &con->flags);
1581 close_connection(con, true, true, true);
1582 clean_one_writequeue(con);
1583 }
1584
1585 spin_lock(&dlm_node_addrs_spin);
1586 na = find_node_addr(nodeid);
1587 if (na) {
1588 list_del(&na->list);
1589 while (na->addr_count--)
1590 kfree(na->addr[na->addr_count]);
1591 kfree(na);
1592 }
1593 spin_unlock(&dlm_node_addrs_spin);
1594
1595 return 0;
1596}
1597
1598/* Receive workqueue function */
1599static void process_recv_sockets(struct work_struct *work)
1600{
1601 struct connection *con = container_of(work, struct connection, rwork);
1602 int err;
1603
1604 clear_bit(CF_READ_PENDING, &con->flags);
1605 do {
1606 err = con->rx_action(con);
1607 } while (!err);
1608}
1609
1610/* Send workqueue function */
1611static void process_send_sockets(struct work_struct *work)
1612{
1613 struct connection *con = container_of(work, struct connection, swork);
1614
1615 clear_bit(CF_WRITE_PENDING, &con->flags);
1616 if (con->sock == NULL) /* not mutex protected so check it inside too */
1617 con->connect_action(con);
1618 if (!list_empty(&con->writequeue))
1619 send_to_sock(con);
1620}
1621
1622
1623/* Discard all entries on the write queues */
1624static void clean_writequeues(void)
1625{
1626 foreach_conn(clean_one_writequeue);
1627}
1628
1629static void work_stop(void)
1630{
1631 if (recv_workqueue)
1632 destroy_workqueue(recv_workqueue);
1633 if (send_workqueue)
1634 destroy_workqueue(send_workqueue);
1635}
1636
1637static int work_start(void)
1638{
1639 recv_workqueue = alloc_workqueue("dlm_recv",
1640 WQ_UNBOUND | WQ_MEM_RECLAIM, 1);
1641 if (!recv_workqueue) {
1642 log_print("can't start dlm_recv");
1643 return -ENOMEM;
1644 }
1645
1646 send_workqueue = alloc_workqueue("dlm_send",
1647 WQ_UNBOUND | WQ_MEM_RECLAIM, 1);
1648 if (!send_workqueue) {
1649 log_print("can't start dlm_send");
1650 destroy_workqueue(recv_workqueue);
1651 return -ENOMEM;
1652 }
1653
1654 return 0;
1655}
1656
1657static void _stop_conn(struct connection *con, bool and_other)
1658{
1659 mutex_lock(&con->sock_mutex);
1660 set_bit(CF_CLOSE, &con->flags);
1661 set_bit(CF_READ_PENDING, &con->flags);
1662 set_bit(CF_WRITE_PENDING, &con->flags);
1663 if (con->sock && con->sock->sk) {
1664 write_lock_bh(&con->sock->sk->sk_callback_lock);
1665 con->sock->sk->sk_user_data = NULL;
1666 write_unlock_bh(&con->sock->sk->sk_callback_lock);
1667 }
1668 if (con->othercon && and_other)
1669 _stop_conn(con->othercon, false);
1670 mutex_unlock(&con->sock_mutex);
1671}
1672
1673static void stop_conn(struct connection *con)
1674{
1675 _stop_conn(con, true);
1676}
1677
1678static void free_conn(struct connection *con)
1679{
1680 close_connection(con, true, true, true);
1681 if (con->othercon)
1682 kmem_cache_free(con_cache, con->othercon);
1683 hlist_del(&con->list);
1684 kmem_cache_free(con_cache, con);
1685}
1686
1687static void work_flush(void)
1688{
1689 int ok;
1690 int i;
1691 struct hlist_node *n;
1692 struct connection *con;
1693
1694 if (recv_workqueue)
1695 flush_workqueue(recv_workqueue);
1696 if (send_workqueue)
1697 flush_workqueue(send_workqueue);
1698 do {
1699 ok = 1;
1700 foreach_conn(stop_conn);
1701 if (recv_workqueue)
1702 flush_workqueue(recv_workqueue);
1703 if (send_workqueue)
1704 flush_workqueue(send_workqueue);
1705 for (i = 0; i < CONN_HASH_SIZE && ok; i++) {
1706 hlist_for_each_entry_safe(con, n,
1707 &connection_hash[i], list) {
1708 ok &= test_bit(CF_READ_PENDING, &con->flags);
1709 ok &= test_bit(CF_WRITE_PENDING, &con->flags);
1710 if (con->othercon) {
1711 ok &= test_bit(CF_READ_PENDING,
1712 &con->othercon->flags);
1713 ok &= test_bit(CF_WRITE_PENDING,
1714 &con->othercon->flags);
1715 }
1716 }
1717 }
1718 } while (!ok);
1719}
1720
1721void dlm_lowcomms_stop(void)
1722{
1723 /* Set all the flags to prevent any
1724 socket activity.
1725 */
1726 mutex_lock(&connections_lock);
1727 dlm_allow_conn = 0;
1728 mutex_unlock(&connections_lock);
1729 work_flush();
1730 clean_writequeues();
1731 foreach_conn(free_conn);
1732 work_stop();
1733
1734 kmem_cache_destroy(con_cache);
1735}
1736
1737int dlm_lowcomms_start(void)
1738{
1739 int error = -EINVAL;
1740 struct connection *con;
1741 int i;
1742
1743 for (i = 0; i < CONN_HASH_SIZE; i++)
1744 INIT_HLIST_HEAD(&connection_hash[i]);
1745
1746 init_local();
1747 if (!dlm_local_count) {
1748 error = -ENOTCONN;
1749 log_print("no local IP address has been set");
1750 goto fail;
1751 }
1752
1753 error = -ENOMEM;
1754 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection),
1755 __alignof__(struct connection), 0,
1756 NULL);
1757 if (!con_cache)
1758 goto fail;
1759
1760 error = work_start();
1761 if (error)
1762 goto fail_destroy;
1763
1764 dlm_allow_conn = 1;
1765
1766 /* Start listening */
1767 if (dlm_config.ci_protocol == 0)
1768 error = tcp_listen_for_all();
1769 else
1770 error = sctp_listen_for_all();
1771 if (error)
1772 goto fail_unlisten;
1773
1774 return 0;
1775
1776fail_unlisten:
1777 dlm_allow_conn = 0;
1778 con = nodeid2con(0,0);
1779 if (con) {
1780 close_connection(con, false, true, true);
1781 kmem_cache_free(con_cache, con);
1782 }
1783fail_destroy:
1784 kmem_cache_destroy(con_cache);
1785fail:
1786 return error;
1787}
1788
1789void dlm_lowcomms_exit(void)
1790{
1791 struct dlm_node_addr *na, *safe;
1792
1793 spin_lock(&dlm_node_addrs_spin);
1794 list_for_each_entry_safe(na, safe, &dlm_node_addrs, list) {
1795 list_del(&na->list);
1796 while (na->addr_count--)
1797 kfree(na->addr[na->addr_count]);
1798 kfree(na);
1799 }
1800 spin_unlock(&dlm_node_addrs_spin);
1801}
1/******************************************************************************
2*******************************************************************************
3**
4** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
5** Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved.
6**
7** This copyrighted material is made available to anyone wishing to use,
8** modify, copy, or redistribute it subject to the terms and conditions
9** of the GNU General Public License v.2.
10**
11*******************************************************************************
12******************************************************************************/
13
14/*
15 * lowcomms.c
16 *
17 * This is the "low-level" comms layer.
18 *
19 * It is responsible for sending/receiving messages
20 * from other nodes in the cluster.
21 *
22 * Cluster nodes are referred to by their nodeids. nodeids are
23 * simply 32 bit numbers to the locking module - if they need to
24 * be expanded for the cluster infrastructure then that is its
25 * responsibility. It is this layer's
26 * responsibility to resolve these into IP address or
27 * whatever it needs for inter-node communication.
28 *
29 * The comms level is two kernel threads that deal mainly with
30 * the receiving of messages from other nodes and passing them
31 * up to the mid-level comms layer (which understands the
32 * message format) for execution by the locking core, and
33 * a send thread which does all the setting up of connections
34 * to remote nodes and the sending of data. Threads are not allowed
35 * to send their own data because it may cause them to wait in times
36 * of high load. Also, this way, the sending thread can collect together
37 * messages bound for one node and send them in one block.
38 *
39 * lowcomms will choose to use either TCP or SCTP as its transport layer
40 * depending on the configuration variable 'protocol'. This should be set
41 * to 0 (default) for TCP or 1 for SCTP. It should be configured using a
42 * cluster-wide mechanism as it must be the same on all nodes of the cluster
43 * for the DLM to function.
44 *
45 */
46
47#include <asm/ioctls.h>
48#include <net/sock.h>
49#include <net/tcp.h>
50#include <linux/pagemap.h>
51#include <linux/file.h>
52#include <linux/mutex.h>
53#include <linux/sctp.h>
54#include <linux/slab.h>
55#include <net/sctp/sctp.h>
56#include <net/ipv6.h>
57
58#include "dlm_internal.h"
59#include "lowcomms.h"
60#include "midcomms.h"
61#include "config.h"
62
63#define NEEDED_RMEM (4*1024*1024)
64#define CONN_HASH_SIZE 32
65
66/* Number of messages to send before rescheduling */
67#define MAX_SEND_MSG_COUNT 25
68
69struct cbuf {
70 unsigned int base;
71 unsigned int len;
72 unsigned int mask;
73};
74
75static void cbuf_add(struct cbuf *cb, int n)
76{
77 cb->len += n;
78}
79
80static int cbuf_data(struct cbuf *cb)
81{
82 return ((cb->base + cb->len) & cb->mask);
83}
84
85static void cbuf_init(struct cbuf *cb, int size)
86{
87 cb->base = cb->len = 0;
88 cb->mask = size-1;
89}
90
91static void cbuf_eat(struct cbuf *cb, int n)
92{
93 cb->len -= n;
94 cb->base += n;
95 cb->base &= cb->mask;
96}
97
98static bool cbuf_empty(struct cbuf *cb)
99{
100 return cb->len == 0;
101}
102
103struct connection {
104 struct socket *sock; /* NULL if not connected */
105 uint32_t nodeid; /* So we know who we are in the list */
106 struct mutex sock_mutex;
107 unsigned long flags;
108#define CF_READ_PENDING 1
109#define CF_WRITE_PENDING 2
110#define CF_CONNECT_PENDING 3
111#define CF_INIT_PENDING 4
112#define CF_IS_OTHERCON 5
113#define CF_CLOSE 6
114#define CF_APP_LIMITED 7
115 struct list_head writequeue; /* List of outgoing writequeue_entries */
116 spinlock_t writequeue_lock;
117 int (*rx_action) (struct connection *); /* What to do when active */
118 void (*connect_action) (struct connection *); /* What to do to connect */
119 struct page *rx_page;
120 struct cbuf cb;
121 int retries;
122#define MAX_CONNECT_RETRIES 3
123 struct hlist_node list;
124 struct connection *othercon;
125 struct work_struct rwork; /* Receive workqueue */
126 struct work_struct swork; /* Send workqueue */
127 void (*orig_error_report)(struct sock *);
128 void (*orig_data_ready)(struct sock *);
129 void (*orig_state_change)(struct sock *);
130 void (*orig_write_space)(struct sock *);
131};
132#define sock2con(x) ((struct connection *)(x)->sk_user_data)
133
134/* An entry waiting to be sent */
135struct writequeue_entry {
136 struct list_head list;
137 struct page *page;
138 int offset;
139 int len;
140 int end;
141 int users;
142 struct connection *con;
143};
144
145struct dlm_node_addr {
146 struct list_head list;
147 int nodeid;
148 int addr_count;
149 int curr_addr_index;
150 struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT];
151};
152
153static LIST_HEAD(dlm_node_addrs);
154static DEFINE_SPINLOCK(dlm_node_addrs_spin);
155
156static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT];
157static int dlm_local_count;
158static int dlm_allow_conn;
159
160/* Work queues */
161static struct workqueue_struct *recv_workqueue;
162static struct workqueue_struct *send_workqueue;
163
164static struct hlist_head connection_hash[CONN_HASH_SIZE];
165static DEFINE_MUTEX(connections_lock);
166static struct kmem_cache *con_cache;
167
168static void process_recv_sockets(struct work_struct *work);
169static void process_send_sockets(struct work_struct *work);
170
171
172/* This is deliberately very simple because most clusters have simple
173 sequential nodeids, so we should be able to go straight to a connection
174 struct in the array */
175static inline int nodeid_hash(int nodeid)
176{
177 return nodeid & (CONN_HASH_SIZE-1);
178}
179
180static struct connection *__find_con(int nodeid)
181{
182 int r;
183 struct connection *con;
184
185 r = nodeid_hash(nodeid);
186
187 hlist_for_each_entry(con, &connection_hash[r], list) {
188 if (con->nodeid == nodeid)
189 return con;
190 }
191 return NULL;
192}
193
194/*
195 * If 'allocation' is zero then we don't attempt to create a new
196 * connection structure for this node.
197 */
198static struct connection *__nodeid2con(int nodeid, gfp_t alloc)
199{
200 struct connection *con = NULL;
201 int r;
202
203 con = __find_con(nodeid);
204 if (con || !alloc)
205 return con;
206
207 con = kmem_cache_zalloc(con_cache, alloc);
208 if (!con)
209 return NULL;
210
211 r = nodeid_hash(nodeid);
212 hlist_add_head(&con->list, &connection_hash[r]);
213
214 con->nodeid = nodeid;
215 mutex_init(&con->sock_mutex);
216 INIT_LIST_HEAD(&con->writequeue);
217 spin_lock_init(&con->writequeue_lock);
218 INIT_WORK(&con->swork, process_send_sockets);
219 INIT_WORK(&con->rwork, process_recv_sockets);
220
221 /* Setup action pointers for child sockets */
222 if (con->nodeid) {
223 struct connection *zerocon = __find_con(0);
224
225 con->connect_action = zerocon->connect_action;
226 if (!con->rx_action)
227 con->rx_action = zerocon->rx_action;
228 }
229
230 return con;
231}
232
233/* Loop round all connections */
234static void foreach_conn(void (*conn_func)(struct connection *c))
235{
236 int i;
237 struct hlist_node *n;
238 struct connection *con;
239
240 for (i = 0; i < CONN_HASH_SIZE; i++) {
241 hlist_for_each_entry_safe(con, n, &connection_hash[i], list)
242 conn_func(con);
243 }
244}
245
246static struct connection *nodeid2con(int nodeid, gfp_t allocation)
247{
248 struct connection *con;
249
250 mutex_lock(&connections_lock);
251 con = __nodeid2con(nodeid, allocation);
252 mutex_unlock(&connections_lock);
253
254 return con;
255}
256
257static struct dlm_node_addr *find_node_addr(int nodeid)
258{
259 struct dlm_node_addr *na;
260
261 list_for_each_entry(na, &dlm_node_addrs, list) {
262 if (na->nodeid == nodeid)
263 return na;
264 }
265 return NULL;
266}
267
268static int addr_compare(struct sockaddr_storage *x, struct sockaddr_storage *y)
269{
270 switch (x->ss_family) {
271 case AF_INET: {
272 struct sockaddr_in *sinx = (struct sockaddr_in *)x;
273 struct sockaddr_in *siny = (struct sockaddr_in *)y;
274 if (sinx->sin_addr.s_addr != siny->sin_addr.s_addr)
275 return 0;
276 if (sinx->sin_port != siny->sin_port)
277 return 0;
278 break;
279 }
280 case AF_INET6: {
281 struct sockaddr_in6 *sinx = (struct sockaddr_in6 *)x;
282 struct sockaddr_in6 *siny = (struct sockaddr_in6 *)y;
283 if (!ipv6_addr_equal(&sinx->sin6_addr, &siny->sin6_addr))
284 return 0;
285 if (sinx->sin6_port != siny->sin6_port)
286 return 0;
287 break;
288 }
289 default:
290 return 0;
291 }
292 return 1;
293}
294
295static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out,
296 struct sockaddr *sa_out, bool try_new_addr)
297{
298 struct sockaddr_storage sas;
299 struct dlm_node_addr *na;
300
301 if (!dlm_local_count)
302 return -1;
303
304 spin_lock(&dlm_node_addrs_spin);
305 na = find_node_addr(nodeid);
306 if (na && na->addr_count) {
307 memcpy(&sas, na->addr[na->curr_addr_index],
308 sizeof(struct sockaddr_storage));
309
310 if (try_new_addr) {
311 na->curr_addr_index++;
312 if (na->curr_addr_index == na->addr_count)
313 na->curr_addr_index = 0;
314 }
315 }
316 spin_unlock(&dlm_node_addrs_spin);
317
318 if (!na)
319 return -EEXIST;
320
321 if (!na->addr_count)
322 return -ENOENT;
323
324 if (sas_out)
325 memcpy(sas_out, &sas, sizeof(struct sockaddr_storage));
326
327 if (!sa_out)
328 return 0;
329
330 if (dlm_local_addr[0]->ss_family == AF_INET) {
331 struct sockaddr_in *in4 = (struct sockaddr_in *) &sas;
332 struct sockaddr_in *ret4 = (struct sockaddr_in *) sa_out;
333 ret4->sin_addr.s_addr = in4->sin_addr.s_addr;
334 } else {
335 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &sas;
336 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) sa_out;
337 ret6->sin6_addr = in6->sin6_addr;
338 }
339
340 return 0;
341}
342
343static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid)
344{
345 struct dlm_node_addr *na;
346 int rv = -EEXIST;
347 int addr_i;
348
349 spin_lock(&dlm_node_addrs_spin);
350 list_for_each_entry(na, &dlm_node_addrs, list) {
351 if (!na->addr_count)
352 continue;
353
354 for (addr_i = 0; addr_i < na->addr_count; addr_i++) {
355 if (addr_compare(na->addr[addr_i], addr)) {
356 *nodeid = na->nodeid;
357 rv = 0;
358 goto unlock;
359 }
360 }
361 }
362unlock:
363 spin_unlock(&dlm_node_addrs_spin);
364 return rv;
365}
366
367int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len)
368{
369 struct sockaddr_storage *new_addr;
370 struct dlm_node_addr *new_node, *na;
371
372 new_node = kzalloc(sizeof(struct dlm_node_addr), GFP_NOFS);
373 if (!new_node)
374 return -ENOMEM;
375
376 new_addr = kzalloc(sizeof(struct sockaddr_storage), GFP_NOFS);
377 if (!new_addr) {
378 kfree(new_node);
379 return -ENOMEM;
380 }
381
382 memcpy(new_addr, addr, len);
383
384 spin_lock(&dlm_node_addrs_spin);
385 na = find_node_addr(nodeid);
386 if (!na) {
387 new_node->nodeid = nodeid;
388 new_node->addr[0] = new_addr;
389 new_node->addr_count = 1;
390 list_add(&new_node->list, &dlm_node_addrs);
391 spin_unlock(&dlm_node_addrs_spin);
392 return 0;
393 }
394
395 if (na->addr_count >= DLM_MAX_ADDR_COUNT) {
396 spin_unlock(&dlm_node_addrs_spin);
397 kfree(new_addr);
398 kfree(new_node);
399 return -ENOSPC;
400 }
401
402 na->addr[na->addr_count++] = new_addr;
403 spin_unlock(&dlm_node_addrs_spin);
404 kfree(new_node);
405 return 0;
406}
407
408/* Data available on socket or listen socket received a connect */
409static void lowcomms_data_ready(struct sock *sk)
410{
411 struct connection *con = sock2con(sk);
412 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags))
413 queue_work(recv_workqueue, &con->rwork);
414}
415
416static void lowcomms_write_space(struct sock *sk)
417{
418 struct connection *con = sock2con(sk);
419
420 if (!con)
421 return;
422
423 clear_bit(SOCK_NOSPACE, &con->sock->flags);
424
425 if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) {
426 con->sock->sk->sk_write_pending--;
427 clear_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags);
428 }
429
430 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
431 queue_work(send_workqueue, &con->swork);
432}
433
434static inline void lowcomms_connect_sock(struct connection *con)
435{
436 if (test_bit(CF_CLOSE, &con->flags))
437 return;
438 if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags))
439 queue_work(send_workqueue, &con->swork);
440}
441
442static void lowcomms_state_change(struct sock *sk)
443{
444 /* SCTP layer is not calling sk_data_ready when the connection
445 * is done, so we catch the signal through here. Also, it
446 * doesn't switch socket state when entering shutdown, so we
447 * skip the write in that case.
448 */
449 if (sk->sk_shutdown) {
450 if (sk->sk_shutdown == RCV_SHUTDOWN)
451 lowcomms_data_ready(sk);
452 } else if (sk->sk_state == TCP_ESTABLISHED) {
453 lowcomms_write_space(sk);
454 }
455}
456
457int dlm_lowcomms_connect_node(int nodeid)
458{
459 struct connection *con;
460
461 if (nodeid == dlm_our_nodeid())
462 return 0;
463
464 con = nodeid2con(nodeid, GFP_NOFS);
465 if (!con)
466 return -ENOMEM;
467 lowcomms_connect_sock(con);
468 return 0;
469}
470
471static void lowcomms_error_report(struct sock *sk)
472{
473 struct connection *con;
474 struct sockaddr_storage saddr;
475 int buflen;
476 void (*orig_report)(struct sock *) = NULL;
477
478 read_lock_bh(&sk->sk_callback_lock);
479 con = sock2con(sk);
480 if (con == NULL)
481 goto out;
482
483 orig_report = con->orig_error_report;
484 if (con->sock == NULL ||
485 kernel_getpeername(con->sock, (struct sockaddr *)&saddr, &buflen)) {
486 printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
487 "sending to node %d, port %d, "
488 "sk_err=%d/%d\n", dlm_our_nodeid(),
489 con->nodeid, dlm_config.ci_tcp_port,
490 sk->sk_err, sk->sk_err_soft);
491 } else if (saddr.ss_family == AF_INET) {
492 struct sockaddr_in *sin4 = (struct sockaddr_in *)&saddr;
493
494 printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
495 "sending to node %d at %pI4, port %d, "
496 "sk_err=%d/%d\n", dlm_our_nodeid(),
497 con->nodeid, &sin4->sin_addr.s_addr,
498 dlm_config.ci_tcp_port, sk->sk_err,
499 sk->sk_err_soft);
500 } else {
501 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&saddr;
502
503 printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
504 "sending to node %d at %u.%u.%u.%u, "
505 "port %d, sk_err=%d/%d\n", dlm_our_nodeid(),
506 con->nodeid, sin6->sin6_addr.s6_addr32[0],
507 sin6->sin6_addr.s6_addr32[1],
508 sin6->sin6_addr.s6_addr32[2],
509 sin6->sin6_addr.s6_addr32[3],
510 dlm_config.ci_tcp_port, sk->sk_err,
511 sk->sk_err_soft);
512 }
513out:
514 read_unlock_bh(&sk->sk_callback_lock);
515 if (orig_report)
516 orig_report(sk);
517}
518
519/* Note: sk_callback_lock must be locked before calling this function. */
520static void save_callbacks(struct connection *con, struct sock *sk)
521{
522 con->orig_data_ready = sk->sk_data_ready;
523 con->orig_state_change = sk->sk_state_change;
524 con->orig_write_space = sk->sk_write_space;
525 con->orig_error_report = sk->sk_error_report;
526}
527
528static void restore_callbacks(struct connection *con, struct sock *sk)
529{
530 write_lock_bh(&sk->sk_callback_lock);
531 sk->sk_user_data = NULL;
532 sk->sk_data_ready = con->orig_data_ready;
533 sk->sk_state_change = con->orig_state_change;
534 sk->sk_write_space = con->orig_write_space;
535 sk->sk_error_report = con->orig_error_report;
536 write_unlock_bh(&sk->sk_callback_lock);
537}
538
539/* Make a socket active */
540static void add_sock(struct socket *sock, struct connection *con, bool save_cb)
541{
542 struct sock *sk = sock->sk;
543
544 write_lock_bh(&sk->sk_callback_lock);
545 con->sock = sock;
546
547 sk->sk_user_data = con;
548 if (save_cb)
549 save_callbacks(con, sk);
550 /* Install a data_ready callback */
551 sk->sk_data_ready = lowcomms_data_ready;
552 sk->sk_write_space = lowcomms_write_space;
553 sk->sk_state_change = lowcomms_state_change;
554 sk->sk_allocation = GFP_NOFS;
555 sk->sk_error_report = lowcomms_error_report;
556 write_unlock_bh(&sk->sk_callback_lock);
557}
558
559/* Add the port number to an IPv6 or 4 sockaddr and return the address
560 length */
561static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
562 int *addr_len)
563{
564 saddr->ss_family = dlm_local_addr[0]->ss_family;
565 if (saddr->ss_family == AF_INET) {
566 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
567 in4_addr->sin_port = cpu_to_be16(port);
568 *addr_len = sizeof(struct sockaddr_in);
569 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero));
570 } else {
571 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
572 in6_addr->sin6_port = cpu_to_be16(port);
573 *addr_len = sizeof(struct sockaddr_in6);
574 }
575 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len);
576}
577
578/* Close a remote connection and tidy up */
579static void close_connection(struct connection *con, bool and_other,
580 bool tx, bool rx)
581{
582 clear_bit(CF_CONNECT_PENDING, &con->flags);
583 clear_bit(CF_WRITE_PENDING, &con->flags);
584 if (tx && cancel_work_sync(&con->swork))
585 log_print("canceled swork for node %d", con->nodeid);
586 if (rx && cancel_work_sync(&con->rwork))
587 log_print("canceled rwork for node %d", con->nodeid);
588
589 mutex_lock(&con->sock_mutex);
590 if (con->sock) {
591 if (!test_bit(CF_IS_OTHERCON, &con->flags))
592 restore_callbacks(con, con->sock->sk);
593 sock_release(con->sock);
594 con->sock = NULL;
595 }
596 if (con->othercon && and_other) {
597 /* Will only re-enter once. */
598 close_connection(con->othercon, false, true, true);
599 }
600 if (con->rx_page) {
601 __free_page(con->rx_page);
602 con->rx_page = NULL;
603 }
604
605 con->retries = 0;
606 mutex_unlock(&con->sock_mutex);
607}
608
609/* Data received from remote end */
610static int receive_from_sock(struct connection *con)
611{
612 int ret = 0;
613 struct msghdr msg = {};
614 struct kvec iov[2];
615 unsigned len;
616 int r;
617 int call_again_soon = 0;
618 int nvec;
619
620 mutex_lock(&con->sock_mutex);
621
622 if (con->sock == NULL) {
623 ret = -EAGAIN;
624 goto out_close;
625 }
626 if (con->nodeid == 0) {
627 ret = -EINVAL;
628 goto out_close;
629 }
630
631 if (con->rx_page == NULL) {
632 /*
633 * This doesn't need to be atomic, but I think it should
634 * improve performance if it is.
635 */
636 con->rx_page = alloc_page(GFP_ATOMIC);
637 if (con->rx_page == NULL)
638 goto out_resched;
639 cbuf_init(&con->cb, PAGE_SIZE);
640 }
641
642 /*
643 * iov[0] is the bit of the circular buffer between the current end
644 * point (cb.base + cb.len) and the end of the buffer.
645 */
646 iov[0].iov_len = con->cb.base - cbuf_data(&con->cb);
647 iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb);
648 iov[1].iov_len = 0;
649 nvec = 1;
650
651 /*
652 * iov[1] is the bit of the circular buffer between the start of the
653 * buffer and the start of the currently used section (cb.base)
654 */
655 if (cbuf_data(&con->cb) >= con->cb.base) {
656 iov[0].iov_len = PAGE_SIZE - cbuf_data(&con->cb);
657 iov[1].iov_len = con->cb.base;
658 iov[1].iov_base = page_address(con->rx_page);
659 nvec = 2;
660 }
661 len = iov[0].iov_len + iov[1].iov_len;
662
663 r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len,
664 MSG_DONTWAIT | MSG_NOSIGNAL);
665 if (ret <= 0)
666 goto out_close;
667 else if (ret == len)
668 call_again_soon = 1;
669
670 cbuf_add(&con->cb, ret);
671 ret = dlm_process_incoming_buffer(con->nodeid,
672 page_address(con->rx_page),
673 con->cb.base, con->cb.len,
674 PAGE_SIZE);
675 if (ret == -EBADMSG) {
676 log_print("lowcomms: addr=%p, base=%u, len=%u, read=%d",
677 page_address(con->rx_page), con->cb.base,
678 con->cb.len, r);
679 }
680 if (ret < 0)
681 goto out_close;
682 cbuf_eat(&con->cb, ret);
683
684 if (cbuf_empty(&con->cb) && !call_again_soon) {
685 __free_page(con->rx_page);
686 con->rx_page = NULL;
687 }
688
689 if (call_again_soon)
690 goto out_resched;
691 mutex_unlock(&con->sock_mutex);
692 return 0;
693
694out_resched:
695 if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
696 queue_work(recv_workqueue, &con->rwork);
697 mutex_unlock(&con->sock_mutex);
698 return -EAGAIN;
699
700out_close:
701 mutex_unlock(&con->sock_mutex);
702 if (ret != -EAGAIN) {
703 close_connection(con, false, true, false);
704 /* Reconnect when there is something to send */
705 }
706 /* Don't return success if we really got EOF */
707 if (ret == 0)
708 ret = -EAGAIN;
709
710 return ret;
711}
712
713/* Listening socket is busy, accept a connection */
714static int tcp_accept_from_sock(struct connection *con)
715{
716 int result;
717 struct sockaddr_storage peeraddr;
718 struct socket *newsock;
719 int len;
720 int nodeid;
721 struct connection *newcon;
722 struct connection *addcon;
723
724 mutex_lock(&connections_lock);
725 if (!dlm_allow_conn) {
726 mutex_unlock(&connections_lock);
727 return -1;
728 }
729 mutex_unlock(&connections_lock);
730
731 memset(&peeraddr, 0, sizeof(peeraddr));
732 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
733 SOCK_STREAM, IPPROTO_TCP, &newsock);
734 if (result < 0)
735 return -ENOMEM;
736
737 mutex_lock_nested(&con->sock_mutex, 0);
738
739 result = -ENOTCONN;
740 if (con->sock == NULL)
741 goto accept_err;
742
743 newsock->type = con->sock->type;
744 newsock->ops = con->sock->ops;
745
746 result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK);
747 if (result < 0)
748 goto accept_err;
749
750 /* Get the connected socket's peer */
751 memset(&peeraddr, 0, sizeof(peeraddr));
752 if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr,
753 &len, 2)) {
754 result = -ECONNABORTED;
755 goto accept_err;
756 }
757
758 /* Get the new node's NODEID */
759 make_sockaddr(&peeraddr, 0, &len);
760 if (addr_to_nodeid(&peeraddr, &nodeid)) {
761 unsigned char *b=(unsigned char *)&peeraddr;
762 log_print("connect from non cluster node");
763 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE,
764 b, sizeof(struct sockaddr_storage));
765 sock_release(newsock);
766 mutex_unlock(&con->sock_mutex);
767 return -1;
768 }
769
770 log_print("got connection from %d", nodeid);
771
772 /* Check to see if we already have a connection to this node. This
773 * could happen if the two nodes initiate a connection at roughly
774 * the same time and the connections cross on the wire.
775 * In this case we store the incoming one in "othercon"
776 */
777 newcon = nodeid2con(nodeid, GFP_NOFS);
778 if (!newcon) {
779 result = -ENOMEM;
780 goto accept_err;
781 }
782 mutex_lock_nested(&newcon->sock_mutex, 1);
783 if (newcon->sock) {
784 struct connection *othercon = newcon->othercon;
785
786 if (!othercon) {
787 othercon = kmem_cache_zalloc(con_cache, GFP_NOFS);
788 if (!othercon) {
789 log_print("failed to allocate incoming socket");
790 mutex_unlock(&newcon->sock_mutex);
791 result = -ENOMEM;
792 goto accept_err;
793 }
794 othercon->nodeid = nodeid;
795 othercon->rx_action = receive_from_sock;
796 mutex_init(&othercon->sock_mutex);
797 INIT_WORK(&othercon->swork, process_send_sockets);
798 INIT_WORK(&othercon->rwork, process_recv_sockets);
799 set_bit(CF_IS_OTHERCON, &othercon->flags);
800 }
801 if (!othercon->sock) {
802 newcon->othercon = othercon;
803 othercon->sock = newsock;
804 newsock->sk->sk_user_data = othercon;
805 add_sock(newsock, othercon, false);
806 addcon = othercon;
807 }
808 else {
809 printk("Extra connection from node %d attempted\n", nodeid);
810 result = -EAGAIN;
811 mutex_unlock(&newcon->sock_mutex);
812 goto accept_err;
813 }
814 }
815 else {
816 newsock->sk->sk_user_data = newcon;
817 newcon->rx_action = receive_from_sock;
818 /* accept copies the sk after we've saved the callbacks, so we
819 don't want to save them a second time or comm errors will
820 result in calling sk_error_report recursively. */
821 add_sock(newsock, newcon, false);
822 addcon = newcon;
823 }
824
825 mutex_unlock(&newcon->sock_mutex);
826
827 /*
828 * Add it to the active queue in case we got data
829 * between processing the accept adding the socket
830 * to the read_sockets list
831 */
832 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
833 queue_work(recv_workqueue, &addcon->rwork);
834 mutex_unlock(&con->sock_mutex);
835
836 return 0;
837
838accept_err:
839 mutex_unlock(&con->sock_mutex);
840 sock_release(newsock);
841
842 if (result != -EAGAIN)
843 log_print("error accepting connection from node: %d", result);
844 return result;
845}
846
847static int sctp_accept_from_sock(struct connection *con)
848{
849 /* Check that the new node is in the lockspace */
850 struct sctp_prim prim;
851 int nodeid;
852 int prim_len, ret;
853 int addr_len;
854 struct connection *newcon;
855 struct connection *addcon;
856 struct socket *newsock;
857
858 mutex_lock(&connections_lock);
859 if (!dlm_allow_conn) {
860 mutex_unlock(&connections_lock);
861 return -1;
862 }
863 mutex_unlock(&connections_lock);
864
865 mutex_lock_nested(&con->sock_mutex, 0);
866
867 ret = kernel_accept(con->sock, &newsock, O_NONBLOCK);
868 if (ret < 0)
869 goto accept_err;
870
871 memset(&prim, 0, sizeof(struct sctp_prim));
872 prim_len = sizeof(struct sctp_prim);
873
874 ret = kernel_getsockopt(newsock, IPPROTO_SCTP, SCTP_PRIMARY_ADDR,
875 (char *)&prim, &prim_len);
876 if (ret < 0) {
877 log_print("getsockopt/sctp_primary_addr failed: %d", ret);
878 goto accept_err;
879 }
880
881 make_sockaddr(&prim.ssp_addr, 0, &addr_len);
882 ret = addr_to_nodeid(&prim.ssp_addr, &nodeid);
883 if (ret) {
884 unsigned char *b = (unsigned char *)&prim.ssp_addr;
885
886 log_print("reject connect from unknown addr");
887 print_hex_dump_bytes("ss: ", DUMP_PREFIX_NONE,
888 b, sizeof(struct sockaddr_storage));
889 goto accept_err;
890 }
891
892 newcon = nodeid2con(nodeid, GFP_NOFS);
893 if (!newcon) {
894 ret = -ENOMEM;
895 goto accept_err;
896 }
897
898 mutex_lock_nested(&newcon->sock_mutex, 1);
899
900 if (newcon->sock) {
901 struct connection *othercon = newcon->othercon;
902
903 if (!othercon) {
904 othercon = kmem_cache_zalloc(con_cache, GFP_NOFS);
905 if (!othercon) {
906 log_print("failed to allocate incoming socket");
907 mutex_unlock(&newcon->sock_mutex);
908 ret = -ENOMEM;
909 goto accept_err;
910 }
911 othercon->nodeid = nodeid;
912 othercon->rx_action = receive_from_sock;
913 mutex_init(&othercon->sock_mutex);
914 INIT_WORK(&othercon->swork, process_send_sockets);
915 INIT_WORK(&othercon->rwork, process_recv_sockets);
916 set_bit(CF_IS_OTHERCON, &othercon->flags);
917 }
918 if (!othercon->sock) {
919 newcon->othercon = othercon;
920 othercon->sock = newsock;
921 newsock->sk->sk_user_data = othercon;
922 add_sock(newsock, othercon, false);
923 addcon = othercon;
924 } else {
925 printk("Extra connection from node %d attempted\n", nodeid);
926 ret = -EAGAIN;
927 mutex_unlock(&newcon->sock_mutex);
928 goto accept_err;
929 }
930 } else {
931 newsock->sk->sk_user_data = newcon;
932 newcon->rx_action = receive_from_sock;
933 add_sock(newsock, newcon, false);
934 addcon = newcon;
935 }
936
937 log_print("connected to %d", nodeid);
938
939 mutex_unlock(&newcon->sock_mutex);
940
941 /*
942 * Add it to the active queue in case we got data
943 * between processing the accept adding the socket
944 * to the read_sockets list
945 */
946 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
947 queue_work(recv_workqueue, &addcon->rwork);
948 mutex_unlock(&con->sock_mutex);
949
950 return 0;
951
952accept_err:
953 mutex_unlock(&con->sock_mutex);
954 if (newsock)
955 sock_release(newsock);
956 if (ret != -EAGAIN)
957 log_print("error accepting connection from node: %d", ret);
958
959 return ret;
960}
961
962static void free_entry(struct writequeue_entry *e)
963{
964 __free_page(e->page);
965 kfree(e);
966}
967
968/*
969 * writequeue_entry_complete - try to delete and free write queue entry
970 * @e: write queue entry to try to delete
971 * @completed: bytes completed
972 *
973 * writequeue_lock must be held.
974 */
975static void writequeue_entry_complete(struct writequeue_entry *e, int completed)
976{
977 e->offset += completed;
978 e->len -= completed;
979
980 if (e->len == 0 && e->users == 0) {
981 list_del(&e->list);
982 free_entry(e);
983 }
984}
985
986/*
987 * sctp_bind_addrs - bind a SCTP socket to all our addresses
988 */
989static int sctp_bind_addrs(struct connection *con, uint16_t port)
990{
991 struct sockaddr_storage localaddr;
992 int i, addr_len, result = 0;
993
994 for (i = 0; i < dlm_local_count; i++) {
995 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr));
996 make_sockaddr(&localaddr, port, &addr_len);
997
998 if (!i)
999 result = kernel_bind(con->sock,
1000 (struct sockaddr *)&localaddr,
1001 addr_len);
1002 else
1003 result = kernel_setsockopt(con->sock, SOL_SCTP,
1004 SCTP_SOCKOPT_BINDX_ADD,
1005 (char *)&localaddr, addr_len);
1006
1007 if (result < 0) {
1008 log_print("Can't bind to %d addr number %d, %d.\n",
1009 port, i + 1, result);
1010 break;
1011 }
1012 }
1013 return result;
1014}
1015
1016/* Initiate an SCTP association.
1017 This is a special case of send_to_sock() in that we don't yet have a
1018 peeled-off socket for this association, so we use the listening socket
1019 and add the primary IP address of the remote node.
1020 */
1021static void sctp_connect_to_sock(struct connection *con)
1022{
1023 struct sockaddr_storage daddr;
1024 int one = 1;
1025 int result;
1026 int addr_len;
1027 struct socket *sock;
1028
1029 if (con->nodeid == 0) {
1030 log_print("attempt to connect sock 0 foiled");
1031 return;
1032 }
1033
1034 mutex_lock(&con->sock_mutex);
1035
1036 /* Some odd races can cause double-connects, ignore them */
1037 if (con->retries++ > MAX_CONNECT_RETRIES)
1038 goto out;
1039
1040 if (con->sock) {
1041 log_print("node %d already connected.", con->nodeid);
1042 goto out;
1043 }
1044
1045 memset(&daddr, 0, sizeof(daddr));
1046 result = nodeid_to_addr(con->nodeid, &daddr, NULL, true);
1047 if (result < 0) {
1048 log_print("no address for nodeid %d", con->nodeid);
1049 goto out;
1050 }
1051
1052 /* Create a socket to communicate with */
1053 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
1054 SOCK_STREAM, IPPROTO_SCTP, &sock);
1055 if (result < 0)
1056 goto socket_err;
1057
1058 sock->sk->sk_user_data = con;
1059 con->rx_action = receive_from_sock;
1060 con->connect_action = sctp_connect_to_sock;
1061 add_sock(sock, con, true);
1062
1063 /* Bind to all addresses. */
1064 if (sctp_bind_addrs(con, 0))
1065 goto bind_err;
1066
1067 make_sockaddr(&daddr, dlm_config.ci_tcp_port, &addr_len);
1068
1069 log_print("connecting to %d", con->nodeid);
1070
1071 /* Turn off Nagle's algorithm */
1072 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one,
1073 sizeof(one));
1074
1075 result = sock->ops->connect(sock, (struct sockaddr *)&daddr, addr_len,
1076 O_NONBLOCK);
1077 if (result == -EINPROGRESS)
1078 result = 0;
1079 if (result == 0)
1080 goto out;
1081
1082
1083bind_err:
1084 con->sock = NULL;
1085 sock_release(sock);
1086
1087socket_err:
1088 /*
1089 * Some errors are fatal and this list might need adjusting. For other
1090 * errors we try again until the max number of retries is reached.
1091 */
1092 if (result != -EHOSTUNREACH &&
1093 result != -ENETUNREACH &&
1094 result != -ENETDOWN &&
1095 result != -EINVAL &&
1096 result != -EPROTONOSUPPORT) {
1097 log_print("connect %d try %d error %d", con->nodeid,
1098 con->retries, result);
1099 mutex_unlock(&con->sock_mutex);
1100 msleep(1000);
1101 clear_bit(CF_CONNECT_PENDING, &con->flags);
1102 lowcomms_connect_sock(con);
1103 return;
1104 }
1105
1106out:
1107 mutex_unlock(&con->sock_mutex);
1108 set_bit(CF_WRITE_PENDING, &con->flags);
1109}
1110
1111/* Connect a new socket to its peer */
1112static void tcp_connect_to_sock(struct connection *con)
1113{
1114 struct sockaddr_storage saddr, src_addr;
1115 int addr_len;
1116 struct socket *sock = NULL;
1117 int one = 1;
1118 int result;
1119
1120 if (con->nodeid == 0) {
1121 log_print("attempt to connect sock 0 foiled");
1122 return;
1123 }
1124
1125 mutex_lock(&con->sock_mutex);
1126 if (con->retries++ > MAX_CONNECT_RETRIES)
1127 goto out;
1128
1129 /* Some odd races can cause double-connects, ignore them */
1130 if (con->sock)
1131 goto out;
1132
1133 /* Create a socket to communicate with */
1134 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
1135 SOCK_STREAM, IPPROTO_TCP, &sock);
1136 if (result < 0)
1137 goto out_err;
1138
1139 memset(&saddr, 0, sizeof(saddr));
1140 result = nodeid_to_addr(con->nodeid, &saddr, NULL, false);
1141 if (result < 0) {
1142 log_print("no address for nodeid %d", con->nodeid);
1143 goto out_err;
1144 }
1145
1146 sock->sk->sk_user_data = con;
1147 con->rx_action = receive_from_sock;
1148 con->connect_action = tcp_connect_to_sock;
1149 add_sock(sock, con, true);
1150
1151 /* Bind to our cluster-known address connecting to avoid
1152 routing problems */
1153 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr));
1154 make_sockaddr(&src_addr, 0, &addr_len);
1155 result = sock->ops->bind(sock, (struct sockaddr *) &src_addr,
1156 addr_len);
1157 if (result < 0) {
1158 log_print("could not bind for connect: %d", result);
1159 /* This *may* not indicate a critical error */
1160 }
1161
1162 make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len);
1163
1164 log_print("connecting to %d", con->nodeid);
1165
1166 /* Turn off Nagle's algorithm */
1167 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one,
1168 sizeof(one));
1169
1170 result = sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len,
1171 O_NONBLOCK);
1172 if (result == -EINPROGRESS)
1173 result = 0;
1174 if (result == 0)
1175 goto out;
1176
1177out_err:
1178 if (con->sock) {
1179 sock_release(con->sock);
1180 con->sock = NULL;
1181 } else if (sock) {
1182 sock_release(sock);
1183 }
1184 /*
1185 * Some errors are fatal and this list might need adjusting. For other
1186 * errors we try again until the max number of retries is reached.
1187 */
1188 if (result != -EHOSTUNREACH &&
1189 result != -ENETUNREACH &&
1190 result != -ENETDOWN &&
1191 result != -EINVAL &&
1192 result != -EPROTONOSUPPORT) {
1193 log_print("connect %d try %d error %d", con->nodeid,
1194 con->retries, result);
1195 mutex_unlock(&con->sock_mutex);
1196 msleep(1000);
1197 clear_bit(CF_CONNECT_PENDING, &con->flags);
1198 lowcomms_connect_sock(con);
1199 return;
1200 }
1201out:
1202 mutex_unlock(&con->sock_mutex);
1203 set_bit(CF_WRITE_PENDING, &con->flags);
1204 return;
1205}
1206
1207static struct socket *tcp_create_listen_sock(struct connection *con,
1208 struct sockaddr_storage *saddr)
1209{
1210 struct socket *sock = NULL;
1211 int result = 0;
1212 int one = 1;
1213 int addr_len;
1214
1215 if (dlm_local_addr[0]->ss_family == AF_INET)
1216 addr_len = sizeof(struct sockaddr_in);
1217 else
1218 addr_len = sizeof(struct sockaddr_in6);
1219
1220 /* Create a socket to communicate with */
1221 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
1222 SOCK_STREAM, IPPROTO_TCP, &sock);
1223 if (result < 0) {
1224 log_print("Can't create listening comms socket");
1225 goto create_out;
1226 }
1227
1228 /* Turn off Nagle's algorithm */
1229 kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY, (char *)&one,
1230 sizeof(one));
1231
1232 result = kernel_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
1233 (char *)&one, sizeof(one));
1234
1235 if (result < 0) {
1236 log_print("Failed to set SO_REUSEADDR on socket: %d", result);
1237 }
1238 sock->sk->sk_user_data = con;
1239
1240 con->rx_action = tcp_accept_from_sock;
1241 con->connect_action = tcp_connect_to_sock;
1242
1243 /* Bind to our port */
1244 make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len);
1245 result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len);
1246 if (result < 0) {
1247 log_print("Can't bind to port %d", dlm_config.ci_tcp_port);
1248 sock_release(sock);
1249 sock = NULL;
1250 con->sock = NULL;
1251 goto create_out;
1252 }
1253 result = kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
1254 (char *)&one, sizeof(one));
1255 if (result < 0) {
1256 log_print("Set keepalive failed: %d", result);
1257 }
1258
1259 result = sock->ops->listen(sock, 5);
1260 if (result < 0) {
1261 log_print("Can't listen on port %d", dlm_config.ci_tcp_port);
1262 sock_release(sock);
1263 sock = NULL;
1264 goto create_out;
1265 }
1266
1267create_out:
1268 return sock;
1269}
1270
1271/* Get local addresses */
1272static void init_local(void)
1273{
1274 struct sockaddr_storage sas, *addr;
1275 int i;
1276
1277 dlm_local_count = 0;
1278 for (i = 0; i < DLM_MAX_ADDR_COUNT; i++) {
1279 if (dlm_our_addr(&sas, i))
1280 break;
1281
1282 addr = kmemdup(&sas, sizeof(*addr), GFP_NOFS);
1283 if (!addr)
1284 break;
1285 dlm_local_addr[dlm_local_count++] = addr;
1286 }
1287}
1288
1289/* Initialise SCTP socket and bind to all interfaces */
1290static int sctp_listen_for_all(void)
1291{
1292 struct socket *sock = NULL;
1293 int result = -EINVAL;
1294 struct connection *con = nodeid2con(0, GFP_NOFS);
1295 int bufsize = NEEDED_RMEM;
1296 int one = 1;
1297
1298 if (!con)
1299 return -ENOMEM;
1300
1301 log_print("Using SCTP for communications");
1302
1303 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family,
1304 SOCK_STREAM, IPPROTO_SCTP, &sock);
1305 if (result < 0) {
1306 log_print("Can't create comms socket, check SCTP is loaded");
1307 goto out;
1308 }
1309
1310 result = kernel_setsockopt(sock, SOL_SOCKET, SO_RCVBUFFORCE,
1311 (char *)&bufsize, sizeof(bufsize));
1312 if (result)
1313 log_print("Error increasing buffer space on socket %d", result);
1314
1315 result = kernel_setsockopt(sock, SOL_SCTP, SCTP_NODELAY, (char *)&one,
1316 sizeof(one));
1317 if (result < 0)
1318 log_print("Could not set SCTP NODELAY error %d\n", result);
1319
1320 write_lock_bh(&sock->sk->sk_callback_lock);
1321 /* Init con struct */
1322 sock->sk->sk_user_data = con;
1323 con->sock = sock;
1324 con->sock->sk->sk_data_ready = lowcomms_data_ready;
1325 con->rx_action = sctp_accept_from_sock;
1326 con->connect_action = sctp_connect_to_sock;
1327
1328 write_unlock_bh(&sock->sk->sk_callback_lock);
1329
1330 /* Bind to all addresses. */
1331 if (sctp_bind_addrs(con, dlm_config.ci_tcp_port))
1332 goto create_delsock;
1333
1334 result = sock->ops->listen(sock, 5);
1335 if (result < 0) {
1336 log_print("Can't set socket listening");
1337 goto create_delsock;
1338 }
1339
1340 return 0;
1341
1342create_delsock:
1343 sock_release(sock);
1344 con->sock = NULL;
1345out:
1346 return result;
1347}
1348
1349static int tcp_listen_for_all(void)
1350{
1351 struct socket *sock = NULL;
1352 struct connection *con = nodeid2con(0, GFP_NOFS);
1353 int result = -EINVAL;
1354
1355 if (!con)
1356 return -ENOMEM;
1357
1358 /* We don't support multi-homed hosts */
1359 if (dlm_local_addr[1] != NULL) {
1360 log_print("TCP protocol can't handle multi-homed hosts, "
1361 "try SCTP");
1362 return -EINVAL;
1363 }
1364
1365 log_print("Using TCP for communications");
1366
1367 sock = tcp_create_listen_sock(con, dlm_local_addr[0]);
1368 if (sock) {
1369 add_sock(sock, con, true);
1370 result = 0;
1371 }
1372 else {
1373 result = -EADDRINUSE;
1374 }
1375
1376 return result;
1377}
1378
1379
1380
1381static struct writequeue_entry *new_writequeue_entry(struct connection *con,
1382 gfp_t allocation)
1383{
1384 struct writequeue_entry *entry;
1385
1386 entry = kmalloc(sizeof(struct writequeue_entry), allocation);
1387 if (!entry)
1388 return NULL;
1389
1390 entry->page = alloc_page(allocation);
1391 if (!entry->page) {
1392 kfree(entry);
1393 return NULL;
1394 }
1395
1396 entry->offset = 0;
1397 entry->len = 0;
1398 entry->end = 0;
1399 entry->users = 0;
1400 entry->con = con;
1401
1402 return entry;
1403}
1404
1405void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)
1406{
1407 struct connection *con;
1408 struct writequeue_entry *e;
1409 int offset = 0;
1410
1411 con = nodeid2con(nodeid, allocation);
1412 if (!con)
1413 return NULL;
1414
1415 spin_lock(&con->writequeue_lock);
1416 e = list_entry(con->writequeue.prev, struct writequeue_entry, list);
1417 if ((&e->list == &con->writequeue) ||
1418 (PAGE_SIZE - e->end < len)) {
1419 e = NULL;
1420 } else {
1421 offset = e->end;
1422 e->end += len;
1423 e->users++;
1424 }
1425 spin_unlock(&con->writequeue_lock);
1426
1427 if (e) {
1428 got_one:
1429 *ppc = page_address(e->page) + offset;
1430 return e;
1431 }
1432
1433 e = new_writequeue_entry(con, allocation);
1434 if (e) {
1435 spin_lock(&con->writequeue_lock);
1436 offset = e->end;
1437 e->end += len;
1438 e->users++;
1439 list_add_tail(&e->list, &con->writequeue);
1440 spin_unlock(&con->writequeue_lock);
1441 goto got_one;
1442 }
1443 return NULL;
1444}
1445
1446void dlm_lowcomms_commit_buffer(void *mh)
1447{
1448 struct writequeue_entry *e = (struct writequeue_entry *)mh;
1449 struct connection *con = e->con;
1450 int users;
1451
1452 spin_lock(&con->writequeue_lock);
1453 users = --e->users;
1454 if (users)
1455 goto out;
1456 e->len = e->end - e->offset;
1457 spin_unlock(&con->writequeue_lock);
1458
1459 if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) {
1460 queue_work(send_workqueue, &con->swork);
1461 }
1462 return;
1463
1464out:
1465 spin_unlock(&con->writequeue_lock);
1466 return;
1467}
1468
1469/* Send a message */
1470static void send_to_sock(struct connection *con)
1471{
1472 int ret = 0;
1473 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
1474 struct writequeue_entry *e;
1475 int len, offset;
1476 int count = 0;
1477
1478 mutex_lock(&con->sock_mutex);
1479 if (con->sock == NULL)
1480 goto out_connect;
1481
1482 spin_lock(&con->writequeue_lock);
1483 for (;;) {
1484 e = list_entry(con->writequeue.next, struct writequeue_entry,
1485 list);
1486 if ((struct list_head *) e == &con->writequeue)
1487 break;
1488
1489 len = e->len;
1490 offset = e->offset;
1491 BUG_ON(len == 0 && e->users == 0);
1492 spin_unlock(&con->writequeue_lock);
1493
1494 ret = 0;
1495 if (len) {
1496 ret = kernel_sendpage(con->sock, e->page, offset, len,
1497 msg_flags);
1498 if (ret == -EAGAIN || ret == 0) {
1499 if (ret == -EAGAIN &&
1500 test_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags) &&
1501 !test_and_set_bit(CF_APP_LIMITED, &con->flags)) {
1502 /* Notify TCP that we're limited by the
1503 * application window size.
1504 */
1505 set_bit(SOCK_NOSPACE, &con->sock->flags);
1506 con->sock->sk->sk_write_pending++;
1507 }
1508 cond_resched();
1509 goto out;
1510 } else if (ret < 0)
1511 goto send_error;
1512 }
1513
1514 /* Don't starve people filling buffers */
1515 if (++count >= MAX_SEND_MSG_COUNT) {
1516 cond_resched();
1517 count = 0;
1518 }
1519
1520 spin_lock(&con->writequeue_lock);
1521 writequeue_entry_complete(e, ret);
1522 }
1523 spin_unlock(&con->writequeue_lock);
1524out:
1525 mutex_unlock(&con->sock_mutex);
1526 return;
1527
1528send_error:
1529 mutex_unlock(&con->sock_mutex);
1530 close_connection(con, false, false, true);
1531 lowcomms_connect_sock(con);
1532 return;
1533
1534out_connect:
1535 mutex_unlock(&con->sock_mutex);
1536 lowcomms_connect_sock(con);
1537}
1538
1539static void clean_one_writequeue(struct connection *con)
1540{
1541 struct writequeue_entry *e, *safe;
1542
1543 spin_lock(&con->writequeue_lock);
1544 list_for_each_entry_safe(e, safe, &con->writequeue, list) {
1545 list_del(&e->list);
1546 free_entry(e);
1547 }
1548 spin_unlock(&con->writequeue_lock);
1549}
1550
1551/* Called from recovery when it knows that a node has
1552 left the cluster */
1553int dlm_lowcomms_close(int nodeid)
1554{
1555 struct connection *con;
1556 struct dlm_node_addr *na;
1557
1558 log_print("closing connection to node %d", nodeid);
1559 con = nodeid2con(nodeid, 0);
1560 if (con) {
1561 set_bit(CF_CLOSE, &con->flags);
1562 close_connection(con, true, true, true);
1563 clean_one_writequeue(con);
1564 }
1565
1566 spin_lock(&dlm_node_addrs_spin);
1567 na = find_node_addr(nodeid);
1568 if (na) {
1569 list_del(&na->list);
1570 while (na->addr_count--)
1571 kfree(na->addr[na->addr_count]);
1572 kfree(na);
1573 }
1574 spin_unlock(&dlm_node_addrs_spin);
1575
1576 return 0;
1577}
1578
1579/* Receive workqueue function */
1580static void process_recv_sockets(struct work_struct *work)
1581{
1582 struct connection *con = container_of(work, struct connection, rwork);
1583 int err;
1584
1585 clear_bit(CF_READ_PENDING, &con->flags);
1586 do {
1587 err = con->rx_action(con);
1588 } while (!err);
1589}
1590
1591/* Send workqueue function */
1592static void process_send_sockets(struct work_struct *work)
1593{
1594 struct connection *con = container_of(work, struct connection, swork);
1595
1596 if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags))
1597 con->connect_action(con);
1598 if (test_and_clear_bit(CF_WRITE_PENDING, &con->flags))
1599 send_to_sock(con);
1600}
1601
1602
1603/* Discard all entries on the write queues */
1604static void clean_writequeues(void)
1605{
1606 foreach_conn(clean_one_writequeue);
1607}
1608
1609static void work_stop(void)
1610{
1611 destroy_workqueue(recv_workqueue);
1612 destroy_workqueue(send_workqueue);
1613}
1614
1615static int work_start(void)
1616{
1617 recv_workqueue = alloc_workqueue("dlm_recv",
1618 WQ_UNBOUND | WQ_MEM_RECLAIM, 1);
1619 if (!recv_workqueue) {
1620 log_print("can't start dlm_recv");
1621 return -ENOMEM;
1622 }
1623
1624 send_workqueue = alloc_workqueue("dlm_send",
1625 WQ_UNBOUND | WQ_MEM_RECLAIM, 1);
1626 if (!send_workqueue) {
1627 log_print("can't start dlm_send");
1628 destroy_workqueue(recv_workqueue);
1629 return -ENOMEM;
1630 }
1631
1632 return 0;
1633}
1634
1635static void stop_conn(struct connection *con)
1636{
1637 con->flags |= 0x0F;
1638 if (con->sock && con->sock->sk)
1639 con->sock->sk->sk_user_data = NULL;
1640}
1641
1642static void free_conn(struct connection *con)
1643{
1644 close_connection(con, true, true, true);
1645 if (con->othercon)
1646 kmem_cache_free(con_cache, con->othercon);
1647 hlist_del(&con->list);
1648 kmem_cache_free(con_cache, con);
1649}
1650
1651void dlm_lowcomms_stop(void)
1652{
1653 /* Set all the flags to prevent any
1654 socket activity.
1655 */
1656 mutex_lock(&connections_lock);
1657 dlm_allow_conn = 0;
1658 foreach_conn(stop_conn);
1659 clean_writequeues();
1660 foreach_conn(free_conn);
1661 mutex_unlock(&connections_lock);
1662
1663 work_stop();
1664
1665 kmem_cache_destroy(con_cache);
1666}
1667
1668int dlm_lowcomms_start(void)
1669{
1670 int error = -EINVAL;
1671 struct connection *con;
1672 int i;
1673
1674 for (i = 0; i < CONN_HASH_SIZE; i++)
1675 INIT_HLIST_HEAD(&connection_hash[i]);
1676
1677 init_local();
1678 if (!dlm_local_count) {
1679 error = -ENOTCONN;
1680 log_print("no local IP address has been set");
1681 goto fail;
1682 }
1683
1684 error = -ENOMEM;
1685 con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection),
1686 __alignof__(struct connection), 0,
1687 NULL);
1688 if (!con_cache)
1689 goto fail;
1690
1691 error = work_start();
1692 if (error)
1693 goto fail_destroy;
1694
1695 dlm_allow_conn = 1;
1696
1697 /* Start listening */
1698 if (dlm_config.ci_protocol == 0)
1699 error = tcp_listen_for_all();
1700 else
1701 error = sctp_listen_for_all();
1702 if (error)
1703 goto fail_unlisten;
1704
1705 return 0;
1706
1707fail_unlisten:
1708 dlm_allow_conn = 0;
1709 con = nodeid2con(0,0);
1710 if (con) {
1711 close_connection(con, false, true, true);
1712 kmem_cache_free(con_cache, con);
1713 }
1714fail_destroy:
1715 kmem_cache_destroy(con_cache);
1716fail:
1717 return error;
1718}
1719
1720void dlm_lowcomms_exit(void)
1721{
1722 struct dlm_node_addr *na, *safe;
1723
1724 spin_lock(&dlm_node_addrs_spin);
1725 list_for_each_entry_safe(na, safe, &dlm_node_addrs, list) {
1726 list_del(&na->list);
1727 while (na->addr_count--)
1728 kfree(na->addr[na->addr_count]);
1729 kfree(na);
1730 }
1731 spin_unlock(&dlm_node_addrs_spin);
1732}