O2net: Disallow o2net accept connection request from itself.
[linux-2.6.git] / fs / ocfs2 / cluster / tcp.c
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  *
3  * vim: noexpandtab sw=8 ts=8 sts=0:
4  *
5  * Copyright (C) 2004 Oracle.  All rights reserved.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public
9  * License as published by the Free Software Foundation; either
10  * version 2 of the License, or (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public
18  * License along with this program; if not, write to the
19  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20  * Boston, MA 021110-1307, USA.
21  *
22  * ----
23  *
24  * Callers for this were originally written against a very simple synchronus
25  * API.  This implementation reflects those simple callers.  Some day I'm sure
26  * we'll need to move to a more robust posting/callback mechanism.
27  *
28  * Transmit calls pass in kernel virtual addresses and block copying this into
29  * the socket's tx buffers via a usual blocking sendmsg.  They'll block waiting
30  * for a failed socket to timeout.  TX callers can also pass in a poniter to an
31  * 'int' which gets filled with an errno off the wire in response to the
32  * message they send.
33  *
34  * Handlers for unsolicited messages are registered.  Each socket has a page
35  * that incoming data is copied into.  First the header, then the data.
36  * Handlers are called from only one thread with a reference to this per-socket
37  * page.  This page is destroyed after the handler call, so it can't be
38  * referenced beyond the call.  Handlers may block but are discouraged from
39  * doing so.
40  *
41  * Any framing errors (bad magic, large payload lengths) close a connection.
42  *
43  * Our sock_container holds the state we associate with a socket.  It's current
44  * framing state is held there as well as the refcounting we do around when it
45  * is safe to tear down the socket.  The socket is only finally torn down from
46  * the container when the container loses all of its references -- so as long
47  * as you hold a ref on the container you can trust that the socket is valid
48  * for use with kernel socket APIs.
49  *
50  * Connections are initiated between a pair of nodes when the node with the
51  * higher node number gets a heartbeat callback which indicates that the lower
52  * numbered node has started heartbeating.  The lower numbered node is passive
53  * and only accepts the connection if the higher numbered node is heartbeating.
54  */
55
56 #include <linux/kernel.h>
57 #include <linux/jiffies.h>
58 #include <linux/slab.h>
59 #include <linux/idr.h>
60 #include <linux/kref.h>
61 #include <linux/net.h>
62 #include <net/tcp.h>
63
64 #include <asm/uaccess.h>
65
66 #include "heartbeat.h"
67 #include "tcp.h"
68 #include "nodemanager.h"
69 #define MLOG_MASK_PREFIX ML_TCP
70 #include "masklog.h"
71 #include "quorum.h"
72
73 #include "tcp_internal.h"
74
75 #define SC_NODEF_FMT "node %s (num %u) at %pI4:%u"
76 #define SC_NODEF_ARGS(sc) sc->sc_node->nd_name, sc->sc_node->nd_num,    \
77                           &sc->sc_node->nd_ipv4_address,                \
78                           ntohs(sc->sc_node->nd_ipv4_port)
79
80 /*
81  * In the following two log macros, the whitespace after the ',' just
82  * before ##args is intentional. Otherwise, gcc 2.95 will eat the
83  * previous token if args expands to nothing.
84  */
85 #define msglog(hdr, fmt, args...) do {                                  \
86         typeof(hdr) __hdr = (hdr);                                      \
87         mlog(ML_MSG, "[mag %u len %u typ %u stat %d sys_stat %d "       \
88              "key %08x num %u] " fmt,                                   \
89              be16_to_cpu(__hdr->magic), be16_to_cpu(__hdr->data_len),   \
90              be16_to_cpu(__hdr->msg_type), be32_to_cpu(__hdr->status),  \
91              be32_to_cpu(__hdr->sys_status), be32_to_cpu(__hdr->key),   \
92              be32_to_cpu(__hdr->msg_num) ,  ##args);                    \
93 } while (0)
94
95 #define sclog(sc, fmt, args...) do {                                    \
96         typeof(sc) __sc = (sc);                                         \
97         mlog(ML_SOCKET, "[sc %p refs %d sock %p node %u page %p "       \
98              "pg_off %zu] " fmt, __sc,                                  \
99              atomic_read(&__sc->sc_kref.refcount), __sc->sc_sock,       \
100             __sc->sc_node->nd_num, __sc->sc_page, __sc->sc_page_off ,   \
101             ##args);                                                    \
102 } while (0)
103
104 static DEFINE_RWLOCK(o2net_handler_lock);
105 static struct rb_root o2net_handler_tree = RB_ROOT;
106
107 static struct o2net_node o2net_nodes[O2NM_MAX_NODES];
108
109 /* XXX someday we'll need better accounting */
110 static struct socket *o2net_listen_sock = NULL;
111
112 /*
113  * listen work is only queued by the listening socket callbacks on the
114  * o2net_wq.  teardown detaches the callbacks before destroying the workqueue.
115  * quorum work is queued as sock containers are shutdown.. stop_listening
116  * tears down all the node's sock containers, preventing future shutdowns
117  * and queued quroum work, before canceling delayed quorum work and
118  * destroying the work queue.
119  */
120 static struct workqueue_struct *o2net_wq;
121 static struct work_struct o2net_listen_work;
122
123 static struct o2hb_callback_func o2net_hb_up, o2net_hb_down;
124 #define O2NET_HB_PRI 0x1
125
126 static struct o2net_handshake *o2net_hand;
127 static struct o2net_msg *o2net_keep_req, *o2net_keep_resp;
128
129 static int o2net_sys_err_translations[O2NET_ERR_MAX] =
130                 {[O2NET_ERR_NONE]       = 0,
131                  [O2NET_ERR_NO_HNDLR]   = -ENOPROTOOPT,
132                  [O2NET_ERR_OVERFLOW]   = -EOVERFLOW,
133                  [O2NET_ERR_DIED]       = -EHOSTDOWN,};
134
135 /* can't quite avoid *all* internal declarations :/ */
136 static void o2net_sc_connect_completed(struct work_struct *work);
137 static void o2net_rx_until_empty(struct work_struct *work);
138 static void o2net_shutdown_sc(struct work_struct *work);
139 static void o2net_listen_data_ready(struct sock *sk, int bytes);
140 static void o2net_sc_send_keep_req(struct work_struct *work);
141 static void o2net_idle_timer(unsigned long data);
142 static void o2net_sc_postpone_idle(struct o2net_sock_container *sc);
143 static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc);
144
145 #ifdef CONFIG_DEBUG_FS
146 static void o2net_init_nst(struct o2net_send_tracking *nst, u32 msgtype,
147                            u32 msgkey, struct task_struct *task, u8 node)
148 {
149         INIT_LIST_HEAD(&nst->st_net_debug_item);
150         nst->st_task = task;
151         nst->st_msg_type = msgtype;
152         nst->st_msg_key = msgkey;
153         nst->st_node = node;
154 }
155
156 static void o2net_set_nst_sock_time(struct o2net_send_tracking *nst)
157 {
158         do_gettimeofday(&nst->st_sock_time);
159 }
160
161 static void o2net_set_nst_send_time(struct o2net_send_tracking *nst)
162 {
163         do_gettimeofday(&nst->st_send_time);
164 }
165
166 static void o2net_set_nst_status_time(struct o2net_send_tracking *nst)
167 {
168         do_gettimeofday(&nst->st_status_time);
169 }
170
171 static void o2net_set_nst_sock_container(struct o2net_send_tracking *nst,
172                                          struct o2net_sock_container *sc)
173 {
174         nst->st_sc = sc;
175 }
176
177 static void o2net_set_nst_msg_id(struct o2net_send_tracking *nst, u32 msg_id)
178 {
179         nst->st_id = msg_id;
180 }
181
182 #else  /* CONFIG_DEBUG_FS */
183
184 static inline void o2net_init_nst(struct o2net_send_tracking *nst, u32 msgtype,
185                                   u32 msgkey, struct task_struct *task, u8 node)
186 {
187 }
188
189 static inline void o2net_set_nst_sock_time(struct o2net_send_tracking *nst)
190 {
191 }
192
193 static inline void o2net_set_nst_send_time(struct o2net_send_tracking *nst)
194 {
195 }
196
197 static inline void o2net_set_nst_status_time(struct o2net_send_tracking *nst)
198 {
199 }
200
201 static inline void o2net_set_nst_sock_container(struct o2net_send_tracking *nst,
202                                                 struct o2net_sock_container *sc)
203 {
204 }
205
206 static inline void o2net_set_nst_msg_id(struct o2net_send_tracking *nst,
207                                         u32 msg_id)
208 {
209 }
210
211 #endif /* CONFIG_DEBUG_FS */
212
213 static inline int o2net_reconnect_delay(void)
214 {
215         return o2nm_single_cluster->cl_reconnect_delay_ms;
216 }
217
218 static inline int o2net_keepalive_delay(void)
219 {
220         return o2nm_single_cluster->cl_keepalive_delay_ms;
221 }
222
223 static inline int o2net_idle_timeout(void)
224 {
225         return o2nm_single_cluster->cl_idle_timeout_ms;
226 }
227
228 static inline int o2net_sys_err_to_errno(enum o2net_system_error err)
229 {
230         int trans;
231         BUG_ON(err >= O2NET_ERR_MAX);
232         trans = o2net_sys_err_translations[err];
233
234         /* Just in case we mess up the translation table above */
235         BUG_ON(err != O2NET_ERR_NONE && trans == 0);
236         return trans;
237 }
238
239 static struct o2net_node * o2net_nn_from_num(u8 node_num)
240 {
241         BUG_ON(node_num >= ARRAY_SIZE(o2net_nodes));
242         return &o2net_nodes[node_num];
243 }
244
245 static u8 o2net_num_from_nn(struct o2net_node *nn)
246 {
247         BUG_ON(nn == NULL);
248         return nn - o2net_nodes;
249 }
250
251 /* ------------------------------------------------------------ */
252
253 static int o2net_prep_nsw(struct o2net_node *nn, struct o2net_status_wait *nsw)
254 {
255         int ret = 0;
256
257         do {
258                 if (!idr_pre_get(&nn->nn_status_idr, GFP_ATOMIC)) {
259                         ret = -EAGAIN;
260                         break;
261                 }
262                 spin_lock(&nn->nn_lock);
263                 ret = idr_get_new(&nn->nn_status_idr, nsw, &nsw->ns_id);
264                 if (ret == 0)
265                         list_add_tail(&nsw->ns_node_item,
266                                       &nn->nn_status_list);
267                 spin_unlock(&nn->nn_lock);
268         } while (ret == -EAGAIN);
269
270         if (ret == 0)  {
271                 init_waitqueue_head(&nsw->ns_wq);
272                 nsw->ns_sys_status = O2NET_ERR_NONE;
273                 nsw->ns_status = 0;
274         }
275
276         return ret;
277 }
278
279 static void o2net_complete_nsw_locked(struct o2net_node *nn,
280                                       struct o2net_status_wait *nsw,
281                                       enum o2net_system_error sys_status,
282                                       s32 status)
283 {
284         assert_spin_locked(&nn->nn_lock);
285
286         if (!list_empty(&nsw->ns_node_item)) {
287                 list_del_init(&nsw->ns_node_item);
288                 nsw->ns_sys_status = sys_status;
289                 nsw->ns_status = status;
290                 idr_remove(&nn->nn_status_idr, nsw->ns_id);
291                 wake_up(&nsw->ns_wq);
292         }
293 }
294
295 static void o2net_complete_nsw(struct o2net_node *nn,
296                                struct o2net_status_wait *nsw,
297                                u64 id, enum o2net_system_error sys_status,
298                                s32 status)
299 {
300         spin_lock(&nn->nn_lock);
301         if (nsw == NULL) {
302                 if (id > INT_MAX)
303                         goto out;
304
305                 nsw = idr_find(&nn->nn_status_idr, id);
306                 if (nsw == NULL)
307                         goto out;
308         }
309
310         o2net_complete_nsw_locked(nn, nsw, sys_status, status);
311
312 out:
313         spin_unlock(&nn->nn_lock);
314         return;
315 }
316
317 static void o2net_complete_nodes_nsw(struct o2net_node *nn)
318 {
319         struct o2net_status_wait *nsw, *tmp;
320         unsigned int num_kills = 0;
321
322         assert_spin_locked(&nn->nn_lock);
323
324         list_for_each_entry_safe(nsw, tmp, &nn->nn_status_list, ns_node_item) {
325                 o2net_complete_nsw_locked(nn, nsw, O2NET_ERR_DIED, 0);
326                 num_kills++;
327         }
328
329         mlog(0, "completed %d messages for node %u\n", num_kills,
330              o2net_num_from_nn(nn));
331 }
332
333 static int o2net_nsw_completed(struct o2net_node *nn,
334                                struct o2net_status_wait *nsw)
335 {
336         int completed;
337         spin_lock(&nn->nn_lock);
338         completed = list_empty(&nsw->ns_node_item);
339         spin_unlock(&nn->nn_lock);
340         return completed;
341 }
342
343 /* ------------------------------------------------------------ */
344
345 static void sc_kref_release(struct kref *kref)
346 {
347         struct o2net_sock_container *sc = container_of(kref,
348                                         struct o2net_sock_container, sc_kref);
349         BUG_ON(timer_pending(&sc->sc_idle_timeout));
350
351         sclog(sc, "releasing\n");
352
353         if (sc->sc_sock) {
354                 sock_release(sc->sc_sock);
355                 sc->sc_sock = NULL;
356         }
357
358         o2nm_node_put(sc->sc_node);
359         sc->sc_node = NULL;
360
361         o2net_debug_del_sc(sc);
362         kfree(sc);
363 }
364
365 static void sc_put(struct o2net_sock_container *sc)
366 {
367         sclog(sc, "put\n");
368         kref_put(&sc->sc_kref, sc_kref_release);
369 }
370 static void sc_get(struct o2net_sock_container *sc)
371 {
372         sclog(sc, "get\n");
373         kref_get(&sc->sc_kref);
374 }
375 static struct o2net_sock_container *sc_alloc(struct o2nm_node *node)
376 {
377         struct o2net_sock_container *sc, *ret = NULL;
378         struct page *page = NULL;
379
380         page = alloc_page(GFP_NOFS);
381         sc = kzalloc(sizeof(*sc), GFP_NOFS);
382         if (sc == NULL || page == NULL)
383                 goto out;
384
385         kref_init(&sc->sc_kref);
386         o2nm_node_get(node);
387         sc->sc_node = node;
388
389         INIT_WORK(&sc->sc_connect_work, o2net_sc_connect_completed);
390         INIT_WORK(&sc->sc_rx_work, o2net_rx_until_empty);
391         INIT_WORK(&sc->sc_shutdown_work, o2net_shutdown_sc);
392         INIT_DELAYED_WORK(&sc->sc_keepalive_work, o2net_sc_send_keep_req);
393
394         init_timer(&sc->sc_idle_timeout);
395         sc->sc_idle_timeout.function = o2net_idle_timer;
396         sc->sc_idle_timeout.data = (unsigned long)sc;
397
398         sclog(sc, "alloced\n");
399
400         ret = sc;
401         sc->sc_page = page;
402         o2net_debug_add_sc(sc);
403         sc = NULL;
404         page = NULL;
405
406 out:
407         if (page)
408                 __free_page(page);
409         kfree(sc);
410
411         return ret;
412 }
413
414 /* ------------------------------------------------------------ */
415
416 static void o2net_sc_queue_work(struct o2net_sock_container *sc,
417                                 struct work_struct *work)
418 {
419         sc_get(sc);
420         if (!queue_work(o2net_wq, work))
421                 sc_put(sc);
422 }
423 static void o2net_sc_queue_delayed_work(struct o2net_sock_container *sc,
424                                         struct delayed_work *work,
425                                         int delay)
426 {
427         sc_get(sc);
428         if (!queue_delayed_work(o2net_wq, work, delay))
429                 sc_put(sc);
430 }
431 static void o2net_sc_cancel_delayed_work(struct o2net_sock_container *sc,
432                                          struct delayed_work *work)
433 {
434         if (cancel_delayed_work(work))
435                 sc_put(sc);
436 }
437
438 static atomic_t o2net_connected_peers = ATOMIC_INIT(0);
439
440 int o2net_num_connected_peers(void)
441 {
442         return atomic_read(&o2net_connected_peers);
443 }
444
445 static void o2net_set_nn_state(struct o2net_node *nn,
446                                struct o2net_sock_container *sc,
447                                unsigned valid, int err)
448 {
449         int was_valid = nn->nn_sc_valid;
450         int was_err = nn->nn_persistent_error;
451         struct o2net_sock_container *old_sc = nn->nn_sc;
452
453         assert_spin_locked(&nn->nn_lock);
454
455         if (old_sc && !sc)
456                 atomic_dec(&o2net_connected_peers);
457         else if (!old_sc && sc)
458                 atomic_inc(&o2net_connected_peers);
459
460         /* the node num comparison and single connect/accept path should stop
461          * an non-null sc from being overwritten with another */
462         BUG_ON(sc && nn->nn_sc && nn->nn_sc != sc);
463         mlog_bug_on_msg(err && valid, "err %d valid %u\n", err, valid);
464         mlog_bug_on_msg(valid && !sc, "valid %u sc %p\n", valid, sc);
465
466         if (was_valid && !valid && err == 0)
467                 err = -ENOTCONN;
468
469         mlog(ML_CONN, "node %u sc: %p -> %p, valid %u -> %u, err %d -> %d\n",
470              o2net_num_from_nn(nn), nn->nn_sc, sc, nn->nn_sc_valid, valid,
471              nn->nn_persistent_error, err);
472
473         nn->nn_sc = sc;
474         nn->nn_sc_valid = valid ? 1 : 0;
475         nn->nn_persistent_error = err;
476
477         /* mirrors o2net_tx_can_proceed() */
478         if (nn->nn_persistent_error || nn->nn_sc_valid)
479                 wake_up(&nn->nn_sc_wq);
480
481         if (!was_err && nn->nn_persistent_error) {
482                 o2quo_conn_err(o2net_num_from_nn(nn));
483                 queue_delayed_work(o2net_wq, &nn->nn_still_up,
484                                    msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
485         }
486
487         if (was_valid && !valid) {
488                 printk(KERN_NOTICE "o2net: no longer connected to "
489                        SC_NODEF_FMT "\n", SC_NODEF_ARGS(old_sc));
490                 o2net_complete_nodes_nsw(nn);
491         }
492
493         if (!was_valid && valid) {
494                 o2quo_conn_up(o2net_num_from_nn(nn));
495                 cancel_delayed_work(&nn->nn_connect_expired);
496                 printk(KERN_NOTICE "o2net: %s " SC_NODEF_FMT "\n",
497                        o2nm_this_node() > sc->sc_node->nd_num ?
498                                 "connected to" : "accepted connection from",
499                        SC_NODEF_ARGS(sc));
500         }
501
502         /* trigger the connecting worker func as long as we're not valid,
503          * it will back off if it shouldn't connect.  This can be called
504          * from node config teardown and so needs to be careful about
505          * the work queue actually being up. */
506         if (!valid && o2net_wq) {
507                 unsigned long delay;
508                 /* delay if we're withing a RECONNECT_DELAY of the
509                  * last attempt */
510                 delay = (nn->nn_last_connect_attempt +
511                          msecs_to_jiffies(o2net_reconnect_delay()))
512                         - jiffies;
513                 if (delay > msecs_to_jiffies(o2net_reconnect_delay()))
514                         delay = 0;
515                 mlog(ML_CONN, "queueing conn attempt in %lu jiffies\n", delay);
516                 queue_delayed_work(o2net_wq, &nn->nn_connect_work, delay);
517
518                 /*
519                  * Delay the expired work after idle timeout.
520                  *
521                  * We might have lots of failed connection attempts that run
522                  * through here but we only cancel the connect_expired work when
523                  * a connection attempt succeeds.  So only the first enqueue of
524                  * the connect_expired work will do anything.  The rest will see
525                  * that it's already queued and do nothing.
526                  */
527                 delay += msecs_to_jiffies(o2net_idle_timeout());
528                 queue_delayed_work(o2net_wq, &nn->nn_connect_expired, delay);
529         }
530
531         /* keep track of the nn's sc ref for the caller */
532         if ((old_sc == NULL) && sc)
533                 sc_get(sc);
534         if (old_sc && (old_sc != sc)) {
535                 o2net_sc_queue_work(old_sc, &old_sc->sc_shutdown_work);
536                 sc_put(old_sc);
537         }
538 }
539
540 /* see o2net_register_callbacks() */
541 static void o2net_data_ready(struct sock *sk, int bytes)
542 {
543         void (*ready)(struct sock *sk, int bytes);
544
545         read_lock(&sk->sk_callback_lock);
546         if (sk->sk_user_data) {
547                 struct o2net_sock_container *sc = sk->sk_user_data;
548                 sclog(sc, "data_ready hit\n");
549                 do_gettimeofday(&sc->sc_tv_data_ready);
550                 o2net_sc_queue_work(sc, &sc->sc_rx_work);
551                 ready = sc->sc_data_ready;
552         } else {
553                 ready = sk->sk_data_ready;
554         }
555         read_unlock(&sk->sk_callback_lock);
556
557         ready(sk, bytes);
558 }
559
560 /* see o2net_register_callbacks() */
561 static void o2net_state_change(struct sock *sk)
562 {
563         void (*state_change)(struct sock *sk);
564         struct o2net_sock_container *sc;
565
566         read_lock(&sk->sk_callback_lock);
567         sc = sk->sk_user_data;
568         if (sc == NULL) {
569                 state_change = sk->sk_state_change;
570                 goto out;
571         }
572
573         sclog(sc, "state_change to %d\n", sk->sk_state);
574
575         state_change = sc->sc_state_change;
576
577         switch(sk->sk_state) {
578                 /* ignore connecting sockets as they make progress */
579                 case TCP_SYN_SENT:
580                 case TCP_SYN_RECV:
581                         break;
582                 case TCP_ESTABLISHED:
583                         o2net_sc_queue_work(sc, &sc->sc_connect_work);
584                         break;
585                 default:
586                         printk(KERN_INFO "o2net: connection to " SC_NODEF_FMT
587                               " shutdown, state %d\n",
588                               SC_NODEF_ARGS(sc), sk->sk_state);
589                         o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
590                         break;
591         }
592 out:
593         read_unlock(&sk->sk_callback_lock);
594         state_change(sk);
595 }
596
597 /*
598  * we register callbacks so we can queue work on events before calling
599  * the original callbacks.  our callbacks our careful to test user_data
600  * to discover when they've reaced with o2net_unregister_callbacks().
601  */
602 static void o2net_register_callbacks(struct sock *sk,
603                                      struct o2net_sock_container *sc)
604 {
605         write_lock_bh(&sk->sk_callback_lock);
606
607         /* accepted sockets inherit the old listen socket data ready */
608         if (sk->sk_data_ready == o2net_listen_data_ready) {
609                 sk->sk_data_ready = sk->sk_user_data;
610                 sk->sk_user_data = NULL;
611         }
612
613         BUG_ON(sk->sk_user_data != NULL);
614         sk->sk_user_data = sc;
615         sc_get(sc);
616
617         sc->sc_data_ready = sk->sk_data_ready;
618         sc->sc_state_change = sk->sk_state_change;
619         sk->sk_data_ready = o2net_data_ready;
620         sk->sk_state_change = o2net_state_change;
621
622         mutex_init(&sc->sc_send_lock);
623
624         write_unlock_bh(&sk->sk_callback_lock);
625 }
626
627 static int o2net_unregister_callbacks(struct sock *sk,
628                                    struct o2net_sock_container *sc)
629 {
630         int ret = 0;
631
632         write_lock_bh(&sk->sk_callback_lock);
633         if (sk->sk_user_data == sc) {
634                 ret = 1;
635                 sk->sk_user_data = NULL;
636                 sk->sk_data_ready = sc->sc_data_ready;
637                 sk->sk_state_change = sc->sc_state_change;
638         }
639         write_unlock_bh(&sk->sk_callback_lock);
640
641         return ret;
642 }
643
644 /*
645  * this is a little helper that is called by callers who have seen a problem
646  * with an sc and want to detach it from the nn if someone already hasn't beat
647  * them to it.  if an error is given then the shutdown will be persistent
648  * and pending transmits will be canceled.
649  */
650 static void o2net_ensure_shutdown(struct o2net_node *nn,
651                                    struct o2net_sock_container *sc,
652                                    int err)
653 {
654         spin_lock(&nn->nn_lock);
655         if (nn->nn_sc == sc)
656                 o2net_set_nn_state(nn, NULL, 0, err);
657         spin_unlock(&nn->nn_lock);
658 }
659
660 /*
661  * This work queue function performs the blocking parts of socket shutdown.  A
662  * few paths lead here.  set_nn_state will trigger this callback if it sees an
663  * sc detached from the nn.  state_change will also trigger this callback
664  * directly when it sees errors.  In that case we need to call set_nn_state
665  * ourselves as state_change couldn't get the nn_lock and call set_nn_state
666  * itself.
667  */
668 static void o2net_shutdown_sc(struct work_struct *work)
669 {
670         struct o2net_sock_container *sc =
671                 container_of(work, struct o2net_sock_container,
672                              sc_shutdown_work);
673         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
674
675         sclog(sc, "shutting down\n");
676
677         /* drop the callbacks ref and call shutdown only once */
678         if (o2net_unregister_callbacks(sc->sc_sock->sk, sc)) {
679                 /* we shouldn't flush as we're in the thread, the
680                  * races with pending sc work structs are harmless */
681                 del_timer_sync(&sc->sc_idle_timeout);
682                 o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
683                 sc_put(sc);
684                 kernel_sock_shutdown(sc->sc_sock, SHUT_RDWR);
685         }
686
687         /* not fatal so failed connects before the other guy has our
688          * heartbeat can be retried */
689         o2net_ensure_shutdown(nn, sc, 0);
690         sc_put(sc);
691 }
692
693 /* ------------------------------------------------------------ */
694
695 static int o2net_handler_cmp(struct o2net_msg_handler *nmh, u32 msg_type,
696                              u32 key)
697 {
698         int ret = memcmp(&nmh->nh_key, &key, sizeof(key));
699
700         if (ret == 0)
701                 ret = memcmp(&nmh->nh_msg_type, &msg_type, sizeof(msg_type));
702
703         return ret;
704 }
705
706 static struct o2net_msg_handler *
707 o2net_handler_tree_lookup(u32 msg_type, u32 key, struct rb_node ***ret_p,
708                           struct rb_node **ret_parent)
709 {
710         struct rb_node **p = &o2net_handler_tree.rb_node;
711         struct rb_node *parent = NULL;
712         struct o2net_msg_handler *nmh, *ret = NULL;
713         int cmp;
714
715         while (*p) {
716                 parent = *p;
717                 nmh = rb_entry(parent, struct o2net_msg_handler, nh_node);
718                 cmp = o2net_handler_cmp(nmh, msg_type, key);
719
720                 if (cmp < 0)
721                         p = &(*p)->rb_left;
722                 else if (cmp > 0)
723                         p = &(*p)->rb_right;
724                 else {
725                         ret = nmh;
726                         break;
727                 }
728         }
729
730         if (ret_p != NULL)
731                 *ret_p = p;
732         if (ret_parent != NULL)
733                 *ret_parent = parent;
734
735         return ret;
736 }
737
738 static void o2net_handler_kref_release(struct kref *kref)
739 {
740         struct o2net_msg_handler *nmh;
741         nmh = container_of(kref, struct o2net_msg_handler, nh_kref);
742
743         kfree(nmh);
744 }
745
746 static void o2net_handler_put(struct o2net_msg_handler *nmh)
747 {
748         kref_put(&nmh->nh_kref, o2net_handler_kref_release);
749 }
750
751 /* max_len is protection for the handler func.  incoming messages won't
752  * be given to the handler if their payload is longer than the max. */
753 int o2net_register_handler(u32 msg_type, u32 key, u32 max_len,
754                            o2net_msg_handler_func *func, void *data,
755                            o2net_post_msg_handler_func *post_func,
756                            struct list_head *unreg_list)
757 {
758         struct o2net_msg_handler *nmh = NULL;
759         struct rb_node **p, *parent;
760         int ret = 0;
761
762         if (max_len > O2NET_MAX_PAYLOAD_BYTES) {
763                 mlog(0, "max_len for message handler out of range: %u\n",
764                         max_len);
765                 ret = -EINVAL;
766                 goto out;
767         }
768
769         if (!msg_type) {
770                 mlog(0, "no message type provided: %u, %p\n", msg_type, func);
771                 ret = -EINVAL;
772                 goto out;
773
774         }
775         if (!func) {
776                 mlog(0, "no message handler provided: %u, %p\n",
777                        msg_type, func);
778                 ret = -EINVAL;
779                 goto out;
780         }
781
782         nmh = kzalloc(sizeof(struct o2net_msg_handler), GFP_NOFS);
783         if (nmh == NULL) {
784                 ret = -ENOMEM;
785                 goto out;
786         }
787
788         nmh->nh_func = func;
789         nmh->nh_func_data = data;
790         nmh->nh_post_func = post_func;
791         nmh->nh_msg_type = msg_type;
792         nmh->nh_max_len = max_len;
793         nmh->nh_key = key;
794         /* the tree and list get this ref.. they're both removed in
795          * unregister when this ref is dropped */
796         kref_init(&nmh->nh_kref);
797         INIT_LIST_HEAD(&nmh->nh_unregister_item);
798
799         write_lock(&o2net_handler_lock);
800         if (o2net_handler_tree_lookup(msg_type, key, &p, &parent))
801                 ret = -EEXIST;
802         else {
803                 rb_link_node(&nmh->nh_node, parent, p);
804                 rb_insert_color(&nmh->nh_node, &o2net_handler_tree);
805                 list_add_tail(&nmh->nh_unregister_item, unreg_list);
806
807                 mlog(ML_TCP, "registered handler func %p type %u key %08x\n",
808                      func, msg_type, key);
809                 /* we've had some trouble with handlers seemingly vanishing. */
810                 mlog_bug_on_msg(o2net_handler_tree_lookup(msg_type, key, &p,
811                                                           &parent) == NULL,
812                                 "couldn't find handler we *just* registerd "
813                                 "for type %u key %08x\n", msg_type, key);
814         }
815         write_unlock(&o2net_handler_lock);
816         if (ret)
817                 goto out;
818
819 out:
820         if (ret)
821                 kfree(nmh);
822
823         return ret;
824 }
825 EXPORT_SYMBOL_GPL(o2net_register_handler);
826
827 void o2net_unregister_handler_list(struct list_head *list)
828 {
829         struct o2net_msg_handler *nmh, *n;
830
831         write_lock(&o2net_handler_lock);
832         list_for_each_entry_safe(nmh, n, list, nh_unregister_item) {
833                 mlog(ML_TCP, "unregistering handler func %p type %u key %08x\n",
834                      nmh->nh_func, nmh->nh_msg_type, nmh->nh_key);
835                 rb_erase(&nmh->nh_node, &o2net_handler_tree);
836                 list_del_init(&nmh->nh_unregister_item);
837                 kref_put(&nmh->nh_kref, o2net_handler_kref_release);
838         }
839         write_unlock(&o2net_handler_lock);
840 }
841 EXPORT_SYMBOL_GPL(o2net_unregister_handler_list);
842
843 static struct o2net_msg_handler *o2net_handler_get(u32 msg_type, u32 key)
844 {
845         struct o2net_msg_handler *nmh;
846
847         read_lock(&o2net_handler_lock);
848         nmh = o2net_handler_tree_lookup(msg_type, key, NULL, NULL);
849         if (nmh)
850                 kref_get(&nmh->nh_kref);
851         read_unlock(&o2net_handler_lock);
852
853         return nmh;
854 }
855
856 /* ------------------------------------------------------------ */
857
858 static int o2net_recv_tcp_msg(struct socket *sock, void *data, size_t len)
859 {
860         int ret;
861         mm_segment_t oldfs;
862         struct kvec vec = {
863                 .iov_len = len,
864                 .iov_base = data,
865         };
866         struct msghdr msg = {
867                 .msg_iovlen = 1,
868                 .msg_iov = (struct iovec *)&vec,
869                 .msg_flags = MSG_DONTWAIT,
870         };
871
872         oldfs = get_fs();
873         set_fs(get_ds());
874         ret = sock_recvmsg(sock, &msg, len, msg.msg_flags);
875         set_fs(oldfs);
876
877         return ret;
878 }
879
880 static int o2net_send_tcp_msg(struct socket *sock, struct kvec *vec,
881                               size_t veclen, size_t total)
882 {
883         int ret;
884         mm_segment_t oldfs;
885         struct msghdr msg = {
886                 .msg_iov = (struct iovec *)vec,
887                 .msg_iovlen = veclen,
888         };
889
890         if (sock == NULL) {
891                 ret = -EINVAL;
892                 goto out;
893         }
894
895         oldfs = get_fs();
896         set_fs(get_ds());
897         ret = sock_sendmsg(sock, &msg, total);
898         set_fs(oldfs);
899         if (ret != total) {
900                 mlog(ML_ERROR, "sendmsg returned %d instead of %zu\n", ret,
901                      total);
902                 if (ret >= 0)
903                         ret = -EPIPE; /* should be smarter, I bet */
904                 goto out;
905         }
906
907         ret = 0;
908 out:
909         if (ret < 0)
910                 mlog(0, "returning error: %d\n", ret);
911         return ret;
912 }
913
914 static void o2net_sendpage(struct o2net_sock_container *sc,
915                            void *kmalloced_virt,
916                            size_t size)
917 {
918         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
919         ssize_t ret;
920
921         while (1) {
922                 mutex_lock(&sc->sc_send_lock);
923                 ret = sc->sc_sock->ops->sendpage(sc->sc_sock,
924                                                  virt_to_page(kmalloced_virt),
925                                                  (long)kmalloced_virt & ~PAGE_MASK,
926                                                  size, MSG_DONTWAIT);
927                 mutex_unlock(&sc->sc_send_lock);
928                 if (ret == size)
929                         break;
930                 if (ret == (ssize_t)-EAGAIN) {
931                         mlog(0, "sendpage of size %zu to " SC_NODEF_FMT
932                              " returned EAGAIN\n", size, SC_NODEF_ARGS(sc));
933                         cond_resched();
934                         continue;
935                 }
936                 mlog(ML_ERROR, "sendpage of size %zu to " SC_NODEF_FMT
937                      " failed with %zd\n", size, SC_NODEF_ARGS(sc), ret);
938                 o2net_ensure_shutdown(nn, sc, 0);
939                 break;
940         }
941 }
942
943 static void o2net_init_msg(struct o2net_msg *msg, u16 data_len, u16 msg_type, u32 key)
944 {
945         memset(msg, 0, sizeof(struct o2net_msg));
946         msg->magic = cpu_to_be16(O2NET_MSG_MAGIC);
947         msg->data_len = cpu_to_be16(data_len);
948         msg->msg_type = cpu_to_be16(msg_type);
949         msg->sys_status = cpu_to_be32(O2NET_ERR_NONE);
950         msg->status = 0;
951         msg->key = cpu_to_be32(key);
952 }
953
954 static int o2net_tx_can_proceed(struct o2net_node *nn,
955                                 struct o2net_sock_container **sc_ret,
956                                 int *error)
957 {
958         int ret = 0;
959
960         spin_lock(&nn->nn_lock);
961         if (nn->nn_persistent_error) {
962                 ret = 1;
963                 *sc_ret = NULL;
964                 *error = nn->nn_persistent_error;
965         } else if (nn->nn_sc_valid) {
966                 kref_get(&nn->nn_sc->sc_kref);
967
968                 ret = 1;
969                 *sc_ret = nn->nn_sc;
970                 *error = 0;
971         }
972         spin_unlock(&nn->nn_lock);
973
974         return ret;
975 }
976
977 int o2net_send_message_vec(u32 msg_type, u32 key, struct kvec *caller_vec,
978                            size_t caller_veclen, u8 target_node, int *status)
979 {
980         int ret;
981         struct o2net_msg *msg = NULL;
982         size_t veclen, caller_bytes = 0;
983         struct kvec *vec = NULL;
984         struct o2net_sock_container *sc = NULL;
985         struct o2net_node *nn = o2net_nn_from_num(target_node);
986         struct o2net_status_wait nsw = {
987                 .ns_node_item = LIST_HEAD_INIT(nsw.ns_node_item),
988         };
989         struct o2net_send_tracking nst;
990
991         o2net_init_nst(&nst, msg_type, key, current, target_node);
992
993         if (o2net_wq == NULL) {
994                 mlog(0, "attempt to tx without o2netd running\n");
995                 ret = -ESRCH;
996                 goto out;
997         }
998
999         if (caller_veclen == 0) {
1000                 mlog(0, "bad kvec array length\n");
1001                 ret = -EINVAL;
1002                 goto out;
1003         }
1004
1005         caller_bytes = iov_length((struct iovec *)caller_vec, caller_veclen);
1006         if (caller_bytes > O2NET_MAX_PAYLOAD_BYTES) {
1007                 mlog(0, "total payload len %zu too large\n", caller_bytes);
1008                 ret = -EINVAL;
1009                 goto out;
1010         }
1011
1012         if (target_node == o2nm_this_node()) {
1013                 ret = -ELOOP;
1014                 goto out;
1015         }
1016
1017         o2net_debug_add_nst(&nst);
1018
1019         o2net_set_nst_sock_time(&nst);
1020
1021         wait_event(nn->nn_sc_wq, o2net_tx_can_proceed(nn, &sc, &ret));
1022         if (ret)
1023                 goto out;
1024
1025         o2net_set_nst_sock_container(&nst, sc);
1026
1027         veclen = caller_veclen + 1;
1028         vec = kmalloc(sizeof(struct kvec) * veclen, GFP_ATOMIC);
1029         if (vec == NULL) {
1030                 mlog(0, "failed to %zu element kvec!\n", veclen);
1031                 ret = -ENOMEM;
1032                 goto out;
1033         }
1034
1035         msg = kmalloc(sizeof(struct o2net_msg), GFP_ATOMIC);
1036         if (!msg) {
1037                 mlog(0, "failed to allocate a o2net_msg!\n");
1038                 ret = -ENOMEM;
1039                 goto out;
1040         }
1041
1042         o2net_init_msg(msg, caller_bytes, msg_type, key);
1043
1044         vec[0].iov_len = sizeof(struct o2net_msg);
1045         vec[0].iov_base = msg;
1046         memcpy(&vec[1], caller_vec, caller_veclen * sizeof(struct kvec));
1047
1048         ret = o2net_prep_nsw(nn, &nsw);
1049         if (ret)
1050                 goto out;
1051
1052         msg->msg_num = cpu_to_be32(nsw.ns_id);
1053         o2net_set_nst_msg_id(&nst, nsw.ns_id);
1054
1055         o2net_set_nst_send_time(&nst);
1056
1057         /* finally, convert the message header to network byte-order
1058          * and send */
1059         mutex_lock(&sc->sc_send_lock);
1060         ret = o2net_send_tcp_msg(sc->sc_sock, vec, veclen,
1061                                  sizeof(struct o2net_msg) + caller_bytes);
1062         mutex_unlock(&sc->sc_send_lock);
1063         msglog(msg, "sending returned %d\n", ret);
1064         if (ret < 0) {
1065                 mlog(0, "error returned from o2net_send_tcp_msg=%d\n", ret);
1066                 goto out;
1067         }
1068
1069         /* wait on other node's handler */
1070         o2net_set_nst_status_time(&nst);
1071         wait_event(nsw.ns_wq, o2net_nsw_completed(nn, &nsw));
1072
1073         /* Note that we avoid overwriting the callers status return
1074          * variable if a system error was reported on the other
1075          * side. Callers beware. */
1076         ret = o2net_sys_err_to_errno(nsw.ns_sys_status);
1077         if (status && !ret)
1078                 *status = nsw.ns_status;
1079
1080         mlog(0, "woken, returning system status %d, user status %d\n",
1081              ret, nsw.ns_status);
1082 out:
1083         o2net_debug_del_nst(&nst); /* must be before dropping sc and node */
1084         if (sc)
1085                 sc_put(sc);
1086         if (vec)
1087                 kfree(vec);
1088         if (msg)
1089                 kfree(msg);
1090         o2net_complete_nsw(nn, &nsw, 0, 0, 0);
1091         return ret;
1092 }
1093 EXPORT_SYMBOL_GPL(o2net_send_message_vec);
1094
1095 int o2net_send_message(u32 msg_type, u32 key, void *data, u32 len,
1096                        u8 target_node, int *status)
1097 {
1098         struct kvec vec = {
1099                 .iov_base = data,
1100                 .iov_len = len,
1101         };
1102         return o2net_send_message_vec(msg_type, key, &vec, 1,
1103                                       target_node, status);
1104 }
1105 EXPORT_SYMBOL_GPL(o2net_send_message);
1106
1107 static int o2net_send_status_magic(struct socket *sock, struct o2net_msg *hdr,
1108                                    enum o2net_system_error syserr, int err)
1109 {
1110         struct kvec vec = {
1111                 .iov_base = hdr,
1112                 .iov_len = sizeof(struct o2net_msg),
1113         };
1114
1115         BUG_ON(syserr >= O2NET_ERR_MAX);
1116
1117         /* leave other fields intact from the incoming message, msg_num
1118          * in particular */
1119         hdr->sys_status = cpu_to_be32(syserr);
1120         hdr->status = cpu_to_be32(err);
1121         hdr->magic = cpu_to_be16(O2NET_MSG_STATUS_MAGIC);  // twiddle the magic
1122         hdr->data_len = 0;
1123
1124         msglog(hdr, "about to send status magic %d\n", err);
1125         /* hdr has been in host byteorder this whole time */
1126         return o2net_send_tcp_msg(sock, &vec, 1, sizeof(struct o2net_msg));
1127 }
1128
1129 /* this returns -errno if the header was unknown or too large, etc.
1130  * after this is called the buffer us reused for the next message */
1131 static int o2net_process_message(struct o2net_sock_container *sc,
1132                                  struct o2net_msg *hdr)
1133 {
1134         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1135         int ret = 0, handler_status;
1136         enum  o2net_system_error syserr;
1137         struct o2net_msg_handler *nmh = NULL;
1138         void *ret_data = NULL;
1139
1140         msglog(hdr, "processing message\n");
1141
1142         o2net_sc_postpone_idle(sc);
1143
1144         switch(be16_to_cpu(hdr->magic)) {
1145                 case O2NET_MSG_STATUS_MAGIC:
1146                         /* special type for returning message status */
1147                         o2net_complete_nsw(nn, NULL,
1148                                            be32_to_cpu(hdr->msg_num),
1149                                            be32_to_cpu(hdr->sys_status),
1150                                            be32_to_cpu(hdr->status));
1151                         goto out;
1152                 case O2NET_MSG_KEEP_REQ_MAGIC:
1153                         o2net_sendpage(sc, o2net_keep_resp,
1154                                        sizeof(*o2net_keep_resp));
1155                         goto out;
1156                 case O2NET_MSG_KEEP_RESP_MAGIC:
1157                         goto out;
1158                 case O2NET_MSG_MAGIC:
1159                         break;
1160                 default:
1161                         msglog(hdr, "bad magic\n");
1162                         ret = -EINVAL;
1163                         goto out;
1164                         break;
1165         }
1166
1167         /* find a handler for it */
1168         handler_status = 0;
1169         nmh = o2net_handler_get(be16_to_cpu(hdr->msg_type),
1170                                 be32_to_cpu(hdr->key));
1171         if (!nmh) {
1172                 mlog(ML_TCP, "couldn't find handler for type %u key %08x\n",
1173                      be16_to_cpu(hdr->msg_type), be32_to_cpu(hdr->key));
1174                 syserr = O2NET_ERR_NO_HNDLR;
1175                 goto out_respond;
1176         }
1177
1178         syserr = O2NET_ERR_NONE;
1179
1180         if (be16_to_cpu(hdr->data_len) > nmh->nh_max_len)
1181                 syserr = O2NET_ERR_OVERFLOW;
1182
1183         if (syserr != O2NET_ERR_NONE)
1184                 goto out_respond;
1185
1186         do_gettimeofday(&sc->sc_tv_func_start);
1187         sc->sc_msg_key = be32_to_cpu(hdr->key);
1188         sc->sc_msg_type = be16_to_cpu(hdr->msg_type);
1189         handler_status = (nmh->nh_func)(hdr, sizeof(struct o2net_msg) +
1190                                              be16_to_cpu(hdr->data_len),
1191                                         nmh->nh_func_data, &ret_data);
1192         do_gettimeofday(&sc->sc_tv_func_stop);
1193
1194 out_respond:
1195         /* this destroys the hdr, so don't use it after this */
1196         mutex_lock(&sc->sc_send_lock);
1197         ret = o2net_send_status_magic(sc->sc_sock, hdr, syserr,
1198                                       handler_status);
1199         mutex_unlock(&sc->sc_send_lock);
1200         hdr = NULL;
1201         mlog(0, "sending handler status %d, syserr %d returned %d\n",
1202              handler_status, syserr, ret);
1203
1204         if (nmh) {
1205                 BUG_ON(ret_data != NULL && nmh->nh_post_func == NULL);
1206                 if (nmh->nh_post_func)
1207                         (nmh->nh_post_func)(handler_status, nmh->nh_func_data,
1208                                             ret_data);
1209         }
1210
1211 out:
1212         if (nmh)
1213                 o2net_handler_put(nmh);
1214         return ret;
1215 }
1216
1217 static int o2net_check_handshake(struct o2net_sock_container *sc)
1218 {
1219         struct o2net_handshake *hand = page_address(sc->sc_page);
1220         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1221
1222         if (hand->protocol_version != cpu_to_be64(O2NET_PROTOCOL_VERSION)) {
1223                 mlog(ML_NOTICE, SC_NODEF_FMT " advertised net protocol "
1224                      "version %llu but %llu is required, disconnecting\n",
1225                      SC_NODEF_ARGS(sc),
1226                      (unsigned long long)be64_to_cpu(hand->protocol_version),
1227                      O2NET_PROTOCOL_VERSION);
1228
1229                 /* don't bother reconnecting if its the wrong version. */
1230                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1231                 return -1;
1232         }
1233
1234         /*
1235          * Ensure timeouts are consistent with other nodes, otherwise
1236          * we can end up with one node thinking that the other must be down,
1237          * but isn't. This can ultimately cause corruption.
1238          */
1239         if (be32_to_cpu(hand->o2net_idle_timeout_ms) !=
1240                                 o2net_idle_timeout()) {
1241                 mlog(ML_NOTICE, SC_NODEF_FMT " uses a network idle timeout of "
1242                      "%u ms, but we use %u ms locally.  disconnecting\n",
1243                      SC_NODEF_ARGS(sc),
1244                      be32_to_cpu(hand->o2net_idle_timeout_ms),
1245                      o2net_idle_timeout());
1246                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1247                 return -1;
1248         }
1249
1250         if (be32_to_cpu(hand->o2net_keepalive_delay_ms) !=
1251                         o2net_keepalive_delay()) {
1252                 mlog(ML_NOTICE, SC_NODEF_FMT " uses a keepalive delay of "
1253                      "%u ms, but we use %u ms locally.  disconnecting\n",
1254                      SC_NODEF_ARGS(sc),
1255                      be32_to_cpu(hand->o2net_keepalive_delay_ms),
1256                      o2net_keepalive_delay());
1257                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1258                 return -1;
1259         }
1260
1261         if (be32_to_cpu(hand->o2hb_heartbeat_timeout_ms) !=
1262                         O2HB_MAX_WRITE_TIMEOUT_MS) {
1263                 mlog(ML_NOTICE, SC_NODEF_FMT " uses a heartbeat timeout of "
1264                      "%u ms, but we use %u ms locally.  disconnecting\n",
1265                      SC_NODEF_ARGS(sc),
1266                      be32_to_cpu(hand->o2hb_heartbeat_timeout_ms),
1267                      O2HB_MAX_WRITE_TIMEOUT_MS);
1268                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1269                 return -1;
1270         }
1271
1272         sc->sc_handshake_ok = 1;
1273
1274         spin_lock(&nn->nn_lock);
1275         /* set valid and queue the idle timers only if it hasn't been
1276          * shut down already */
1277         if (nn->nn_sc == sc) {
1278                 o2net_sc_reset_idle_timer(sc);
1279                 atomic_set(&nn->nn_timeout, 0);
1280                 o2net_set_nn_state(nn, sc, 1, 0);
1281         }
1282         spin_unlock(&nn->nn_lock);
1283
1284         /* shift everything up as though it wasn't there */
1285         sc->sc_page_off -= sizeof(struct o2net_handshake);
1286         if (sc->sc_page_off)
1287                 memmove(hand, hand + 1, sc->sc_page_off);
1288
1289         return 0;
1290 }
1291
1292 /* this demuxes the queued rx bytes into header or payload bits and calls
1293  * handlers as each full message is read off the socket.  it returns -error,
1294  * == 0 eof, or > 0 for progress made.*/
1295 static int o2net_advance_rx(struct o2net_sock_container *sc)
1296 {
1297         struct o2net_msg *hdr;
1298         int ret = 0;
1299         void *data;
1300         size_t datalen;
1301
1302         sclog(sc, "receiving\n");
1303         do_gettimeofday(&sc->sc_tv_advance_start);
1304
1305         if (unlikely(sc->sc_handshake_ok == 0)) {
1306                 if(sc->sc_page_off < sizeof(struct o2net_handshake)) {
1307                         data = page_address(sc->sc_page) + sc->sc_page_off;
1308                         datalen = sizeof(struct o2net_handshake) - sc->sc_page_off;
1309                         ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1310                         if (ret > 0)
1311                                 sc->sc_page_off += ret;
1312                 }
1313
1314                 if (sc->sc_page_off == sizeof(struct o2net_handshake)) {
1315                         o2net_check_handshake(sc);
1316                         if (unlikely(sc->sc_handshake_ok == 0))
1317                                 ret = -EPROTO;
1318                 }
1319                 goto out;
1320         }
1321
1322         /* do we need more header? */
1323         if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1324                 data = page_address(sc->sc_page) + sc->sc_page_off;
1325                 datalen = sizeof(struct o2net_msg) - sc->sc_page_off;
1326                 ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1327                 if (ret > 0) {
1328                         sc->sc_page_off += ret;
1329                         /* only swab incoming here.. we can
1330                          * only get here once as we cross from
1331                          * being under to over */
1332                         if (sc->sc_page_off == sizeof(struct o2net_msg)) {
1333                                 hdr = page_address(sc->sc_page);
1334                                 if (be16_to_cpu(hdr->data_len) >
1335                                     O2NET_MAX_PAYLOAD_BYTES)
1336                                         ret = -EOVERFLOW;
1337                         }
1338                 }
1339                 if (ret <= 0)
1340                         goto out;
1341         }
1342
1343         if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1344                 /* oof, still don't have a header */
1345                 goto out;
1346         }
1347
1348         /* this was swabbed above when we first read it */
1349         hdr = page_address(sc->sc_page);
1350
1351         msglog(hdr, "at page_off %zu\n", sc->sc_page_off);
1352
1353         /* do we need more payload? */
1354         if (sc->sc_page_off - sizeof(struct o2net_msg) < be16_to_cpu(hdr->data_len)) {
1355                 /* need more payload */
1356                 data = page_address(sc->sc_page) + sc->sc_page_off;
1357                 datalen = (sizeof(struct o2net_msg) + be16_to_cpu(hdr->data_len)) -
1358                           sc->sc_page_off;
1359                 ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1360                 if (ret > 0)
1361                         sc->sc_page_off += ret;
1362                 if (ret <= 0)
1363                         goto out;
1364         }
1365
1366         if (sc->sc_page_off - sizeof(struct o2net_msg) == be16_to_cpu(hdr->data_len)) {
1367                 /* we can only get here once, the first time we read
1368                  * the payload.. so set ret to progress if the handler
1369                  * works out. after calling this the message is toast */
1370                 ret = o2net_process_message(sc, hdr);
1371                 if (ret == 0)
1372                         ret = 1;
1373                 sc->sc_page_off = 0;
1374         }
1375
1376 out:
1377         sclog(sc, "ret = %d\n", ret);
1378         do_gettimeofday(&sc->sc_tv_advance_stop);
1379         return ret;
1380 }
1381
1382 /* this work func is triggerd by data ready.  it reads until it can read no
1383  * more.  it interprets 0, eof, as fatal.  if data_ready hits while we're doing
1384  * our work the work struct will be marked and we'll be called again. */
1385 static void o2net_rx_until_empty(struct work_struct *work)
1386 {
1387         struct o2net_sock_container *sc =
1388                 container_of(work, struct o2net_sock_container, sc_rx_work);
1389         int ret;
1390
1391         do {
1392                 ret = o2net_advance_rx(sc);
1393         } while (ret > 0);
1394
1395         if (ret <= 0 && ret != -EAGAIN) {
1396                 struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1397                 sclog(sc, "saw error %d, closing\n", ret);
1398                 /* not permanent so read failed handshake can retry */
1399                 o2net_ensure_shutdown(nn, sc, 0);
1400         }
1401
1402         sc_put(sc);
1403 }
1404
1405 static int o2net_set_nodelay(struct socket *sock)
1406 {
1407         int ret, val = 1;
1408         mm_segment_t oldfs;
1409
1410         oldfs = get_fs();
1411         set_fs(KERNEL_DS);
1412
1413         /*
1414          * Dear unsuspecting programmer,
1415          *
1416          * Don't use sock_setsockopt() for SOL_TCP.  It doesn't check its level
1417          * argument and assumes SOL_SOCKET so, say, your TCP_NODELAY will
1418          * silently turn into SO_DEBUG.
1419          *
1420          * Yours,
1421          * Keeper of hilariously fragile interfaces.
1422          */
1423         ret = sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY,
1424                                     (char __user *)&val, sizeof(val));
1425
1426         set_fs(oldfs);
1427         return ret;
1428 }
1429
1430 static void o2net_initialize_handshake(void)
1431 {
1432         o2net_hand->o2hb_heartbeat_timeout_ms = cpu_to_be32(
1433                 O2HB_MAX_WRITE_TIMEOUT_MS);
1434         o2net_hand->o2net_idle_timeout_ms = cpu_to_be32(o2net_idle_timeout());
1435         o2net_hand->o2net_keepalive_delay_ms = cpu_to_be32(
1436                 o2net_keepalive_delay());
1437         o2net_hand->o2net_reconnect_delay_ms = cpu_to_be32(
1438                 o2net_reconnect_delay());
1439 }
1440
1441 /* ------------------------------------------------------------ */
1442
1443 /* called when a connect completes and after a sock is accepted.  the
1444  * rx path will see the response and mark the sc valid */
1445 static void o2net_sc_connect_completed(struct work_struct *work)
1446 {
1447         struct o2net_sock_container *sc =
1448                 container_of(work, struct o2net_sock_container,
1449                              sc_connect_work);
1450
1451         mlog(ML_MSG, "sc sending handshake with ver %llu id %llx\n",
1452               (unsigned long long)O2NET_PROTOCOL_VERSION,
1453               (unsigned long long)be64_to_cpu(o2net_hand->connector_id));
1454
1455         o2net_initialize_handshake();
1456         o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1457         sc_put(sc);
1458 }
1459
1460 /* this is called as a work_struct func. */
1461 static void o2net_sc_send_keep_req(struct work_struct *work)
1462 {
1463         struct o2net_sock_container *sc =
1464                 container_of(work, struct o2net_sock_container,
1465                              sc_keepalive_work.work);
1466
1467         o2net_sendpage(sc, o2net_keep_req, sizeof(*o2net_keep_req));
1468         sc_put(sc);
1469 }
1470
1471 /* socket shutdown does a del_timer_sync against this as it tears down.
1472  * we can't start this timer until we've got to the point in sc buildup
1473  * where shutdown is going to be involved */
1474 static void o2net_idle_timer(unsigned long data)
1475 {
1476         struct o2net_sock_container *sc = (struct o2net_sock_container *)data;
1477         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1478         struct timeval now;
1479
1480         do_gettimeofday(&now);
1481
1482         printk(KERN_NOTICE "o2net: connection to " SC_NODEF_FMT " has been idle for %u.%u "
1483              "seconds, shutting it down.\n", SC_NODEF_ARGS(sc),
1484                      o2net_idle_timeout() / 1000,
1485                      o2net_idle_timeout() % 1000);
1486         mlog(ML_NOTICE, "here are some times that might help debug the "
1487              "situation: (tmr %ld.%ld now %ld.%ld dr %ld.%ld adv "
1488              "%ld.%ld:%ld.%ld func (%08x:%u) %ld.%ld:%ld.%ld)\n",
1489              sc->sc_tv_timer.tv_sec, (long) sc->sc_tv_timer.tv_usec,
1490              now.tv_sec, (long) now.tv_usec,
1491              sc->sc_tv_data_ready.tv_sec, (long) sc->sc_tv_data_ready.tv_usec,
1492              sc->sc_tv_advance_start.tv_sec,
1493              (long) sc->sc_tv_advance_start.tv_usec,
1494              sc->sc_tv_advance_stop.tv_sec,
1495              (long) sc->sc_tv_advance_stop.tv_usec,
1496              sc->sc_msg_key, sc->sc_msg_type,
1497              sc->sc_tv_func_start.tv_sec, (long) sc->sc_tv_func_start.tv_usec,
1498              sc->sc_tv_func_stop.tv_sec, (long) sc->sc_tv_func_stop.tv_usec);
1499
1500         /*
1501          * Initialize the nn_timeout so that the next connection attempt
1502          * will continue in o2net_start_connect.
1503          */
1504         atomic_set(&nn->nn_timeout, 1);
1505
1506         o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
1507 }
1508
1509 static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc)
1510 {
1511         o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
1512         o2net_sc_queue_delayed_work(sc, &sc->sc_keepalive_work,
1513                       msecs_to_jiffies(o2net_keepalive_delay()));
1514         do_gettimeofday(&sc->sc_tv_timer);
1515         mod_timer(&sc->sc_idle_timeout,
1516                jiffies + msecs_to_jiffies(o2net_idle_timeout()));
1517 }
1518
1519 static void o2net_sc_postpone_idle(struct o2net_sock_container *sc)
1520 {
1521         /* Only push out an existing timer */
1522         if (timer_pending(&sc->sc_idle_timeout))
1523                 o2net_sc_reset_idle_timer(sc);
1524 }
1525
1526 /* this work func is kicked whenever a path sets the nn state which doesn't
1527  * have valid set.  This includes seeing hb come up, losing a connection,
1528  * having a connect attempt fail, etc. This centralizes the logic which decides
1529  * if a connect attempt should be made or if we should give up and all future
1530  * transmit attempts should fail */
1531 static void o2net_start_connect(struct work_struct *work)
1532 {
1533         struct o2net_node *nn =
1534                 container_of(work, struct o2net_node, nn_connect_work.work);
1535         struct o2net_sock_container *sc = NULL;
1536         struct o2nm_node *node = NULL, *mynode = NULL;
1537         struct socket *sock = NULL;
1538         struct sockaddr_in myaddr = {0, }, remoteaddr = {0, };
1539         int ret = 0, stop;
1540         unsigned int timeout;
1541
1542         /* if we're greater we initiate tx, otherwise we accept */
1543         if (o2nm_this_node() <= o2net_num_from_nn(nn))
1544                 goto out;
1545
1546         /* watch for racing with tearing a node down */
1547         node = o2nm_get_node_by_num(o2net_num_from_nn(nn));
1548         if (node == NULL) {
1549                 ret = 0;
1550                 goto out;
1551         }
1552
1553         mynode = o2nm_get_node_by_num(o2nm_this_node());
1554         if (mynode == NULL) {
1555                 ret = 0;
1556                 goto out;
1557         }
1558
1559         spin_lock(&nn->nn_lock);
1560         /*
1561          * see if we already have one pending or have given up.
1562          * For nn_timeout, it is set when we close the connection
1563          * because of the idle time out. So it means that we have
1564          * at least connected to that node successfully once,
1565          * now try to connect to it again.
1566          */
1567         timeout = atomic_read(&nn->nn_timeout);
1568         stop = (nn->nn_sc ||
1569                 (nn->nn_persistent_error &&
1570                 (nn->nn_persistent_error != -ENOTCONN || timeout == 0)));
1571         spin_unlock(&nn->nn_lock);
1572         if (stop)
1573                 goto out;
1574
1575         nn->nn_last_connect_attempt = jiffies;
1576
1577         sc = sc_alloc(node);
1578         if (sc == NULL) {
1579                 mlog(0, "couldn't allocate sc\n");
1580                 ret = -ENOMEM;
1581                 goto out;
1582         }
1583
1584         ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1585         if (ret < 0) {
1586                 mlog(0, "can't create socket: %d\n", ret);
1587                 goto out;
1588         }
1589         sc->sc_sock = sock; /* freed by sc_kref_release */
1590
1591         sock->sk->sk_allocation = GFP_ATOMIC;
1592
1593         myaddr.sin_family = AF_INET;
1594         myaddr.sin_addr.s_addr = mynode->nd_ipv4_address;
1595         myaddr.sin_port = htons(0); /* any port */
1596
1597         ret = sock->ops->bind(sock, (struct sockaddr *)&myaddr,
1598                               sizeof(myaddr));
1599         if (ret) {
1600                 mlog(ML_ERROR, "bind failed with %d at address %pI4\n",
1601                      ret, &mynode->nd_ipv4_address);
1602                 goto out;
1603         }
1604
1605         ret = o2net_set_nodelay(sc->sc_sock);
1606         if (ret) {
1607                 mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
1608                 goto out;
1609         }
1610
1611         o2net_register_callbacks(sc->sc_sock->sk, sc);
1612
1613         spin_lock(&nn->nn_lock);
1614         /* handshake completion will set nn->nn_sc_valid */
1615         o2net_set_nn_state(nn, sc, 0, 0);
1616         spin_unlock(&nn->nn_lock);
1617
1618         remoteaddr.sin_family = AF_INET;
1619         remoteaddr.sin_addr.s_addr = node->nd_ipv4_address;
1620         remoteaddr.sin_port = node->nd_ipv4_port;
1621
1622         ret = sc->sc_sock->ops->connect(sc->sc_sock,
1623                                         (struct sockaddr *)&remoteaddr,
1624                                         sizeof(remoteaddr),
1625                                         O_NONBLOCK);
1626         if (ret == -EINPROGRESS)
1627                 ret = 0;
1628
1629 out:
1630         if (ret) {
1631                 mlog(ML_NOTICE, "connect attempt to " SC_NODEF_FMT " failed "
1632                      "with errno %d\n", SC_NODEF_ARGS(sc), ret);
1633                 /* 0 err so that another will be queued and attempted
1634                  * from set_nn_state */
1635                 if (sc)
1636                         o2net_ensure_shutdown(nn, sc, 0);
1637         }
1638         if (sc)
1639                 sc_put(sc);
1640         if (node)
1641                 o2nm_node_put(node);
1642         if (mynode)
1643                 o2nm_node_put(mynode);
1644
1645         return;
1646 }
1647
1648 static void o2net_connect_expired(struct work_struct *work)
1649 {
1650         struct o2net_node *nn =
1651                 container_of(work, struct o2net_node, nn_connect_expired.work);
1652
1653         spin_lock(&nn->nn_lock);
1654         if (!nn->nn_sc_valid) {
1655                 mlog(ML_ERROR, "no connection established with node %u after "
1656                      "%u.%u seconds, giving up and returning errors.\n",
1657                      o2net_num_from_nn(nn),
1658                      o2net_idle_timeout() / 1000,
1659                      o2net_idle_timeout() % 1000);
1660
1661                 o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
1662         }
1663         spin_unlock(&nn->nn_lock);
1664 }
1665
1666 static void o2net_still_up(struct work_struct *work)
1667 {
1668         struct o2net_node *nn =
1669                 container_of(work, struct o2net_node, nn_still_up.work);
1670
1671         o2quo_hb_still_up(o2net_num_from_nn(nn));
1672 }
1673
1674 /* ------------------------------------------------------------ */
1675
1676 void o2net_disconnect_node(struct o2nm_node *node)
1677 {
1678         struct o2net_node *nn = o2net_nn_from_num(node->nd_num);
1679
1680         /* don't reconnect until it's heartbeating again */
1681         spin_lock(&nn->nn_lock);
1682         atomic_set(&nn->nn_timeout, 0);
1683         o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
1684         spin_unlock(&nn->nn_lock);
1685
1686         if (o2net_wq) {
1687                 cancel_delayed_work(&nn->nn_connect_expired);
1688                 cancel_delayed_work(&nn->nn_connect_work);
1689                 cancel_delayed_work(&nn->nn_still_up);
1690                 flush_workqueue(o2net_wq);
1691         }
1692 }
1693
1694 static void o2net_hb_node_down_cb(struct o2nm_node *node, int node_num,
1695                                   void *data)
1696 {
1697         o2quo_hb_down(node_num);
1698
1699         if (node_num != o2nm_this_node())
1700                 o2net_disconnect_node(node);
1701
1702         BUG_ON(atomic_read(&o2net_connected_peers) < 0);
1703 }
1704
1705 static void o2net_hb_node_up_cb(struct o2nm_node *node, int node_num,
1706                                 void *data)
1707 {
1708         struct o2net_node *nn = o2net_nn_from_num(node_num);
1709
1710         o2quo_hb_up(node_num);
1711
1712         /* ensure an immediate connect attempt */
1713         nn->nn_last_connect_attempt = jiffies -
1714                 (msecs_to_jiffies(o2net_reconnect_delay()) + 1);
1715
1716         if (node_num != o2nm_this_node()) {
1717                 /* believe it or not, accept and node hearbeating testing
1718                  * can succeed for this node before we got here.. so
1719                  * only use set_nn_state to clear the persistent error
1720                  * if that hasn't already happened */
1721                 spin_lock(&nn->nn_lock);
1722                 atomic_set(&nn->nn_timeout, 0);
1723                 if (nn->nn_persistent_error)
1724                         o2net_set_nn_state(nn, NULL, 0, 0);
1725                 spin_unlock(&nn->nn_lock);
1726         }
1727 }
1728
1729 void o2net_unregister_hb_callbacks(void)
1730 {
1731         o2hb_unregister_callback(NULL, &o2net_hb_up);
1732         o2hb_unregister_callback(NULL, &o2net_hb_down);
1733 }
1734
1735 int o2net_register_hb_callbacks(void)
1736 {
1737         int ret;
1738
1739         o2hb_setup_callback(&o2net_hb_down, O2HB_NODE_DOWN_CB,
1740                             o2net_hb_node_down_cb, NULL, O2NET_HB_PRI);
1741         o2hb_setup_callback(&o2net_hb_up, O2HB_NODE_UP_CB,
1742                             o2net_hb_node_up_cb, NULL, O2NET_HB_PRI);
1743
1744         ret = o2hb_register_callback(NULL, &o2net_hb_up);
1745         if (ret == 0)
1746                 ret = o2hb_register_callback(NULL, &o2net_hb_down);
1747
1748         if (ret)
1749                 o2net_unregister_hb_callbacks();
1750
1751         return ret;
1752 }
1753
1754 /* ------------------------------------------------------------ */
1755
1756 static int o2net_accept_one(struct socket *sock)
1757 {
1758         int ret, slen;
1759         struct sockaddr_in sin;
1760         struct socket *new_sock = NULL;
1761         struct o2nm_node *node = NULL;
1762         struct o2nm_node *local_node = NULL;
1763         struct o2net_sock_container *sc = NULL;
1764         struct o2net_node *nn;
1765
1766         BUG_ON(sock == NULL);
1767         ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
1768                                sock->sk->sk_protocol, &new_sock);
1769         if (ret)
1770                 goto out;
1771
1772         new_sock->type = sock->type;
1773         new_sock->ops = sock->ops;
1774         ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
1775         if (ret < 0)
1776                 goto out;
1777
1778         new_sock->sk->sk_allocation = GFP_ATOMIC;
1779
1780         ret = o2net_set_nodelay(new_sock);
1781         if (ret) {
1782                 mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
1783                 goto out;
1784         }
1785
1786         slen = sizeof(sin);
1787         ret = new_sock->ops->getname(new_sock, (struct sockaddr *) &sin,
1788                                        &slen, 1);
1789         if (ret < 0)
1790                 goto out;
1791
1792         node = o2nm_get_node_by_ip(sin.sin_addr.s_addr);
1793         if (node == NULL) {
1794                 mlog(ML_NOTICE, "attempt to connect from unknown node at %pI4:%d\n",
1795                      &sin.sin_addr.s_addr, ntohs(sin.sin_port));
1796                 ret = -EINVAL;
1797                 goto out;
1798         }
1799
1800         if (o2nm_this_node() >= node->nd_num) {
1801                 local_node = o2nm_get_node_by_num(o2nm_this_node());
1802                 mlog(ML_NOTICE, "unexpected connect attempt seen at node '%s' ("
1803                      "%u, %pI4:%d) from node '%s' (%u, %pI4:%d)\n",
1804                      local_node->nd_name, local_node->nd_num,
1805                      &(local_node->nd_ipv4_address),
1806                      ntohs(local_node->nd_ipv4_port),
1807                      node->nd_name, node->nd_num, &sin.sin_addr.s_addr,
1808                      ntohs(sin.sin_port));
1809                 ret = -EINVAL;
1810                 goto out;
1811         }
1812
1813         /* this happens all the time when the other node sees our heartbeat
1814          * and tries to connect before we see their heartbeat */
1815         if (!o2hb_check_node_heartbeating_from_callback(node->nd_num)) {
1816                 mlog(ML_CONN, "attempt to connect from node '%s' at "
1817                      "%pI4:%d but it isn't heartbeating\n",
1818                      node->nd_name, &sin.sin_addr.s_addr,
1819                      ntohs(sin.sin_port));
1820                 ret = -EINVAL;
1821                 goto out;
1822         }
1823
1824         nn = o2net_nn_from_num(node->nd_num);
1825
1826         spin_lock(&nn->nn_lock);
1827         if (nn->nn_sc)
1828                 ret = -EBUSY;
1829         else
1830                 ret = 0;
1831         spin_unlock(&nn->nn_lock);
1832         if (ret) {
1833                 mlog(ML_NOTICE, "attempt to connect from node '%s' at "
1834                      "%pI4:%d but it already has an open connection\n",
1835                      node->nd_name, &sin.sin_addr.s_addr,
1836                      ntohs(sin.sin_port));
1837                 goto out;
1838         }
1839
1840         sc = sc_alloc(node);
1841         if (sc == NULL) {
1842                 ret = -ENOMEM;
1843                 goto out;
1844         }
1845
1846         sc->sc_sock = new_sock;
1847         new_sock = NULL;
1848
1849         spin_lock(&nn->nn_lock);
1850         atomic_set(&nn->nn_timeout, 0);
1851         o2net_set_nn_state(nn, sc, 0, 0);
1852         spin_unlock(&nn->nn_lock);
1853
1854         o2net_register_callbacks(sc->sc_sock->sk, sc);
1855         o2net_sc_queue_work(sc, &sc->sc_rx_work);
1856
1857         o2net_initialize_handshake();
1858         o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1859
1860 out:
1861         if (new_sock)
1862                 sock_release(new_sock);
1863         if (node)
1864                 o2nm_node_put(node);
1865         if (local_node)
1866                 o2nm_node_put(local_node);
1867         if (sc)
1868                 sc_put(sc);
1869         return ret;
1870 }
1871
1872 static void o2net_accept_many(struct work_struct *work)
1873 {
1874         struct socket *sock = o2net_listen_sock;
1875         while (o2net_accept_one(sock) == 0)
1876                 cond_resched();
1877 }
1878
1879 static void o2net_listen_data_ready(struct sock *sk, int bytes)
1880 {
1881         void (*ready)(struct sock *sk, int bytes);
1882
1883         read_lock(&sk->sk_callback_lock);
1884         ready = sk->sk_user_data;
1885         if (ready == NULL) { /* check for teardown race */
1886                 ready = sk->sk_data_ready;
1887                 goto out;
1888         }
1889
1890         /* ->sk_data_ready is also called for a newly established child socket
1891          * before it has been accepted and the acceptor has set up their
1892          * data_ready.. we only want to queue listen work for our listening
1893          * socket */
1894         if (sk->sk_state == TCP_LISTEN) {
1895                 mlog(ML_TCP, "bytes: %d\n", bytes);
1896                 queue_work(o2net_wq, &o2net_listen_work);
1897         }
1898
1899 out:
1900         read_unlock(&sk->sk_callback_lock);
1901         ready(sk, bytes);
1902 }
1903
1904 static int o2net_open_listening_sock(__be32 addr, __be16 port)
1905 {
1906         struct socket *sock = NULL;
1907         int ret;
1908         struct sockaddr_in sin = {
1909                 .sin_family = PF_INET,
1910                 .sin_addr = { .s_addr = addr },
1911                 .sin_port = port,
1912         };
1913
1914         ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1915         if (ret < 0) {
1916                 mlog(ML_ERROR, "unable to create socket, ret=%d\n", ret);
1917                 goto out;
1918         }
1919
1920         sock->sk->sk_allocation = GFP_ATOMIC;
1921
1922         write_lock_bh(&sock->sk->sk_callback_lock);
1923         sock->sk->sk_user_data = sock->sk->sk_data_ready;
1924         sock->sk->sk_data_ready = o2net_listen_data_ready;
1925         write_unlock_bh(&sock->sk->sk_callback_lock);
1926
1927         o2net_listen_sock = sock;
1928         INIT_WORK(&o2net_listen_work, o2net_accept_many);
1929
1930         sock->sk->sk_reuse = 1;
1931         ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
1932         if (ret < 0) {
1933                 mlog(ML_ERROR, "unable to bind socket at %pI4:%u, "
1934                      "ret=%d\n", &addr, ntohs(port), ret);
1935                 goto out;
1936         }
1937
1938         ret = sock->ops->listen(sock, 64);
1939         if (ret < 0) {
1940                 mlog(ML_ERROR, "unable to listen on %pI4:%u, ret=%d\n",
1941                      &addr, ntohs(port), ret);
1942         }
1943
1944 out:
1945         if (ret) {
1946                 o2net_listen_sock = NULL;
1947                 if (sock)
1948                         sock_release(sock);
1949         }
1950         return ret;
1951 }
1952
1953 /*
1954  * called from node manager when we should bring up our network listening
1955  * socket.  node manager handles all the serialization to only call this
1956  * once and to match it with o2net_stop_listening().  note,
1957  * o2nm_this_node() doesn't work yet as we're being called while it
1958  * is being set up.
1959  */
1960 int o2net_start_listening(struct o2nm_node *node)
1961 {
1962         int ret = 0;
1963
1964         BUG_ON(o2net_wq != NULL);
1965         BUG_ON(o2net_listen_sock != NULL);
1966
1967         mlog(ML_KTHREAD, "starting o2net thread...\n");
1968         o2net_wq = create_singlethread_workqueue("o2net");
1969         if (o2net_wq == NULL) {
1970                 mlog(ML_ERROR, "unable to launch o2net thread\n");
1971                 return -ENOMEM; /* ? */
1972         }
1973
1974         ret = o2net_open_listening_sock(node->nd_ipv4_address,
1975                                         node->nd_ipv4_port);
1976         if (ret) {
1977                 destroy_workqueue(o2net_wq);
1978                 o2net_wq = NULL;
1979         } else
1980                 o2quo_conn_up(node->nd_num);
1981
1982         return ret;
1983 }
1984
1985 /* again, o2nm_this_node() doesn't work here as we're involved in
1986  * tearing it down */
1987 void o2net_stop_listening(struct o2nm_node *node)
1988 {
1989         struct socket *sock = o2net_listen_sock;
1990         size_t i;
1991
1992         BUG_ON(o2net_wq == NULL);
1993         BUG_ON(o2net_listen_sock == NULL);
1994
1995         /* stop the listening socket from generating work */
1996         write_lock_bh(&sock->sk->sk_callback_lock);
1997         sock->sk->sk_data_ready = sock->sk->sk_user_data;
1998         sock->sk->sk_user_data = NULL;
1999         write_unlock_bh(&sock->sk->sk_callback_lock);
2000
2001         for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
2002                 struct o2nm_node *node = o2nm_get_node_by_num(i);
2003                 if (node) {
2004                         o2net_disconnect_node(node);
2005                         o2nm_node_put(node);
2006                 }
2007         }
2008
2009         /* finish all work and tear down the work queue */
2010         mlog(ML_KTHREAD, "waiting for o2net thread to exit....\n");
2011         destroy_workqueue(o2net_wq);
2012         o2net_wq = NULL;
2013
2014         sock_release(o2net_listen_sock);
2015         o2net_listen_sock = NULL;
2016
2017         o2quo_conn_err(node->nd_num);
2018 }
2019
2020 /* ------------------------------------------------------------ */
2021
2022 int o2net_init(void)
2023 {
2024         unsigned long i;
2025
2026         o2quo_init();
2027
2028         if (o2net_debugfs_init())
2029                 return -ENOMEM;
2030
2031         o2net_hand = kzalloc(sizeof(struct o2net_handshake), GFP_KERNEL);
2032         o2net_keep_req = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
2033         o2net_keep_resp = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
2034         if (!o2net_hand || !o2net_keep_req || !o2net_keep_resp) {
2035                 kfree(o2net_hand);
2036                 kfree(o2net_keep_req);
2037                 kfree(o2net_keep_resp);
2038                 return -ENOMEM;
2039         }
2040
2041         o2net_hand->protocol_version = cpu_to_be64(O2NET_PROTOCOL_VERSION);
2042         o2net_hand->connector_id = cpu_to_be64(1);
2043
2044         o2net_keep_req->magic = cpu_to_be16(O2NET_MSG_KEEP_REQ_MAGIC);
2045         o2net_keep_resp->magic = cpu_to_be16(O2NET_MSG_KEEP_RESP_MAGIC);
2046
2047         for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
2048                 struct o2net_node *nn = o2net_nn_from_num(i);
2049
2050                 atomic_set(&nn->nn_timeout, 0);
2051                 spin_lock_init(&nn->nn_lock);
2052                 INIT_DELAYED_WORK(&nn->nn_connect_work, o2net_start_connect);
2053                 INIT_DELAYED_WORK(&nn->nn_connect_expired,
2054                                   o2net_connect_expired);
2055                 INIT_DELAYED_WORK(&nn->nn_still_up, o2net_still_up);
2056                 /* until we see hb from a node we'll return einval */
2057                 nn->nn_persistent_error = -ENOTCONN;
2058                 init_waitqueue_head(&nn->nn_sc_wq);
2059                 idr_init(&nn->nn_status_idr);
2060                 INIT_LIST_HEAD(&nn->nn_status_list);
2061         }
2062
2063         return 0;
2064 }
2065
2066 void o2net_exit(void)
2067 {
2068         o2quo_exit();
2069         kfree(o2net_hand);
2070         kfree(o2net_keep_req);
2071         kfree(o2net_keep_resp);
2072         o2net_debugfs_exit();
2073 }