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 <linux/export.h>
  63#include <net/tcp.h>
  64
  65#include <asm/uaccess.h>
  66
  67#include "heartbeat.h"
  68#include "tcp.h"
  69#include "nodemanager.h"
  70#define MLOG_MASK_PREFIX ML_TCP
  71#include "masklog.h"
  72#include "quorum.h"
  73
  74#include "tcp_internal.h"
  75
  76#define SC_NODEF_FMT "node %s (num %u) at %pI4:%u"
  77#define SC_NODEF_ARGS(sc) sc->sc_node->nd_name, sc->sc_node->nd_num,	\
  78			  &sc->sc_node->nd_ipv4_address,		\
  79			  ntohs(sc->sc_node->nd_ipv4_port)
  80
  81/*
  82 * In the following two log macros, the whitespace after the ',' just
  83 * before ##args is intentional. Otherwise, gcc 2.95 will eat the
  84 * previous token if args expands to nothing.
  85 */
  86#define msglog(hdr, fmt, args...) do {					\
  87	typeof(hdr) __hdr = (hdr);					\
  88	mlog(ML_MSG, "[mag %u len %u typ %u stat %d sys_stat %d "	\
  89	     "key %08x num %u] " fmt,					\
  90	     be16_to_cpu(__hdr->magic), be16_to_cpu(__hdr->data_len), 	\
  91	     be16_to_cpu(__hdr->msg_type), be32_to_cpu(__hdr->status),	\
  92	     be32_to_cpu(__hdr->sys_status), be32_to_cpu(__hdr->key),	\
  93	     be32_to_cpu(__hdr->msg_num) ,  ##args);			\
  94} while (0)
  95
  96#define sclog(sc, fmt, args...) do {					\
  97	typeof(sc) __sc = (sc);						\
  98	mlog(ML_SOCKET, "[sc %p refs %d sock %p node %u page %p "	\
  99	     "pg_off %zu] " fmt, __sc,					\
 100	     atomic_read(&__sc->sc_kref.refcount), __sc->sc_sock,	\
 101	    __sc->sc_node->nd_num, __sc->sc_page, __sc->sc_page_off ,	\
 102	    ##args);							\
 103} while (0)
 104
 105static DEFINE_RWLOCK(o2net_handler_lock);
 106static struct rb_root o2net_handler_tree = RB_ROOT;
 107
 108static struct o2net_node o2net_nodes[O2NM_MAX_NODES];
 109
 110/* XXX someday we'll need better accounting */
 111static struct socket *o2net_listen_sock = NULL;
 112
 113/*
 114 * listen work is only queued by the listening socket callbacks on the
 115 * o2net_wq.  teardown detaches the callbacks before destroying the workqueue.
 116 * quorum work is queued as sock containers are shutdown.. stop_listening
 117 * tears down all the node's sock containers, preventing future shutdowns
 118 * and queued quroum work, before canceling delayed quorum work and
 119 * destroying the work queue.
 120 */
 121static struct workqueue_struct *o2net_wq;
 122static struct work_struct o2net_listen_work;
 123
 124static struct o2hb_callback_func o2net_hb_up, o2net_hb_down;
 125#define O2NET_HB_PRI 0x1
 126
 127static struct o2net_handshake *o2net_hand;
 128static struct o2net_msg *o2net_keep_req, *o2net_keep_resp;
 129
 130static int o2net_sys_err_translations[O2NET_ERR_MAX] =
 131		{[O2NET_ERR_NONE]	= 0,
 132		 [O2NET_ERR_NO_HNDLR]	= -ENOPROTOOPT,
 133		 [O2NET_ERR_OVERFLOW]	= -EOVERFLOW,
 134		 [O2NET_ERR_DIED]	= -EHOSTDOWN,};
 135
 136/* can't quite avoid *all* internal declarations :/ */
 137static void o2net_sc_connect_completed(struct work_struct *work);
 138static void o2net_rx_until_empty(struct work_struct *work);
 139static void o2net_shutdown_sc(struct work_struct *work);
 140static void o2net_listen_data_ready(struct sock *sk, int bytes);
 141static void o2net_sc_send_keep_req(struct work_struct *work);
 142static void o2net_idle_timer(unsigned long data);
 143static void o2net_sc_postpone_idle(struct o2net_sock_container *sc);
 144static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc);
 145
 146#ifdef CONFIG_DEBUG_FS
 147static void o2net_init_nst(struct o2net_send_tracking *nst, u32 msgtype,
 148			   u32 msgkey, struct task_struct *task, u8 node)
 149{
 150	INIT_LIST_HEAD(&nst->st_net_debug_item);
 151	nst->st_task = task;
 152	nst->st_msg_type = msgtype;
 153	nst->st_msg_key = msgkey;
 154	nst->st_node = node;
 155}
 156
 157static inline void o2net_set_nst_sock_time(struct o2net_send_tracking *nst)
 158{
 159	nst->st_sock_time = ktime_get();
 160}
 161
 162static inline void o2net_set_nst_send_time(struct o2net_send_tracking *nst)
 163{
 164	nst->st_send_time = ktime_get();
 165}
 166
 167static inline void o2net_set_nst_status_time(struct o2net_send_tracking *nst)
 168{
 169	nst->st_status_time = ktime_get();
 170}
 171
 172static inline void o2net_set_nst_sock_container(struct o2net_send_tracking *nst,
 173						struct o2net_sock_container *sc)
 174{
 175	nst->st_sc = sc;
 176}
 177
 178static inline void o2net_set_nst_msg_id(struct o2net_send_tracking *nst,
 179					u32 msg_id)
 180{
 181	nst->st_id = msg_id;
 182}
 183
 184static inline void o2net_set_sock_timer(struct o2net_sock_container *sc)
 185{
 186	sc->sc_tv_timer = ktime_get();
 187}
 188
 189static inline void o2net_set_data_ready_time(struct o2net_sock_container *sc)
 190{
 191	sc->sc_tv_data_ready = ktime_get();
 192}
 193
 194static inline void o2net_set_advance_start_time(struct o2net_sock_container *sc)
 195{
 196	sc->sc_tv_advance_start = ktime_get();
 197}
 198
 199static inline void o2net_set_advance_stop_time(struct o2net_sock_container *sc)
 200{
 201	sc->sc_tv_advance_stop = ktime_get();
 202}
 203
 204static inline void o2net_set_func_start_time(struct o2net_sock_container *sc)
 205{
 206	sc->sc_tv_func_start = ktime_get();
 207}
 208
 209static inline void o2net_set_func_stop_time(struct o2net_sock_container *sc)
 210{
 211	sc->sc_tv_func_stop = ktime_get();
 212}
 213
 214#else  /* CONFIG_DEBUG_FS */
 215# define o2net_init_nst(a, b, c, d, e)
 216# define o2net_set_nst_sock_time(a)
 217# define o2net_set_nst_send_time(a)
 218# define o2net_set_nst_status_time(a)
 219# define o2net_set_nst_sock_container(a, b)
 220# define o2net_set_nst_msg_id(a, b)
 221# define o2net_set_sock_timer(a)
 222# define o2net_set_data_ready_time(a)
 223# define o2net_set_advance_start_time(a)
 224# define o2net_set_advance_stop_time(a)
 225# define o2net_set_func_start_time(a)
 226# define o2net_set_func_stop_time(a)
 227#endif /* CONFIG_DEBUG_FS */
 228
 229#ifdef CONFIG_OCFS2_FS_STATS
 230static ktime_t o2net_get_func_run_time(struct o2net_sock_container *sc)
 231{
 232	return ktime_sub(sc->sc_tv_func_stop, sc->sc_tv_func_start);
 233}
 234
 235static void o2net_update_send_stats(struct o2net_send_tracking *nst,
 236				    struct o2net_sock_container *sc)
 237{
 238	sc->sc_tv_status_total = ktime_add(sc->sc_tv_status_total,
 239					   ktime_sub(ktime_get(),
 240						     nst->st_status_time));
 241	sc->sc_tv_send_total = ktime_add(sc->sc_tv_send_total,
 242					 ktime_sub(nst->st_status_time,
 243						   nst->st_send_time));
 244	sc->sc_tv_acquiry_total = ktime_add(sc->sc_tv_acquiry_total,
 245					    ktime_sub(nst->st_send_time,
 246						      nst->st_sock_time));
 247	sc->sc_send_count++;
 248}
 249
 250static void o2net_update_recv_stats(struct o2net_sock_container *sc)
 251{
 252	sc->sc_tv_process_total = ktime_add(sc->sc_tv_process_total,
 253					    o2net_get_func_run_time(sc));
 254	sc->sc_recv_count++;
 255}
 256
 257#else
 258
 259# define o2net_update_send_stats(a, b)
 260
 261# define o2net_update_recv_stats(sc)
 262
 263#endif /* CONFIG_OCFS2_FS_STATS */
 264
 265static inline int o2net_reconnect_delay(void)
 266{
 267	return o2nm_single_cluster->cl_reconnect_delay_ms;
 268}
 269
 270static inline int o2net_keepalive_delay(void)
 271{
 272	return o2nm_single_cluster->cl_keepalive_delay_ms;
 273}
 274
 275static inline int o2net_idle_timeout(void)
 276{
 277	return o2nm_single_cluster->cl_idle_timeout_ms;
 278}
 279
 280static inline int o2net_sys_err_to_errno(enum o2net_system_error err)
 281{
 282	int trans;
 283	BUG_ON(err >= O2NET_ERR_MAX);
 284	trans = o2net_sys_err_translations[err];
 285
 286	/* Just in case we mess up the translation table above */
 287	BUG_ON(err != O2NET_ERR_NONE && trans == 0);
 288	return trans;
 289}
 290
 291static struct o2net_node * o2net_nn_from_num(u8 node_num)
 292{
 293	BUG_ON(node_num >= ARRAY_SIZE(o2net_nodes));
 294	return &o2net_nodes[node_num];
 295}
 296
 297static u8 o2net_num_from_nn(struct o2net_node *nn)
 298{
 299	BUG_ON(nn == NULL);
 300	return nn - o2net_nodes;
 301}
 302
 303/* ------------------------------------------------------------ */
 304
 305static int o2net_prep_nsw(struct o2net_node *nn, struct o2net_status_wait *nsw)
 306{
 307	int ret = 0;
 308
 309	do {
 310		if (!idr_pre_get(&nn->nn_status_idr, GFP_ATOMIC)) {
 311			ret = -EAGAIN;
 312			break;
 313		}
 314		spin_lock(&nn->nn_lock);
 315		ret = idr_get_new(&nn->nn_status_idr, nsw, &nsw->ns_id);
 316		if (ret == 0)
 317			list_add_tail(&nsw->ns_node_item,
 318				      &nn->nn_status_list);
 319		spin_unlock(&nn->nn_lock);
 320	} while (ret == -EAGAIN);
 321
 322	if (ret == 0)  {
 323		init_waitqueue_head(&nsw->ns_wq);
 324		nsw->ns_sys_status = O2NET_ERR_NONE;
 325		nsw->ns_status = 0;
 326	}
 327
 328	return ret;
 329}
 330
 331static void o2net_complete_nsw_locked(struct o2net_node *nn,
 332				      struct o2net_status_wait *nsw,
 333				      enum o2net_system_error sys_status,
 334				      s32 status)
 335{
 336	assert_spin_locked(&nn->nn_lock);
 337
 338	if (!list_empty(&nsw->ns_node_item)) {
 339		list_del_init(&nsw->ns_node_item);
 340		nsw->ns_sys_status = sys_status;
 341		nsw->ns_status = status;
 342		idr_remove(&nn->nn_status_idr, nsw->ns_id);
 343		wake_up(&nsw->ns_wq);
 344	}
 345}
 346
 347static void o2net_complete_nsw(struct o2net_node *nn,
 348			       struct o2net_status_wait *nsw,
 349			       u64 id, enum o2net_system_error sys_status,
 350			       s32 status)
 351{
 352	spin_lock(&nn->nn_lock);
 353	if (nsw == NULL) {
 354		if (id > INT_MAX)
 355			goto out;
 356
 357		nsw = idr_find(&nn->nn_status_idr, id);
 358		if (nsw == NULL)
 359			goto out;
 360	}
 361
 362	o2net_complete_nsw_locked(nn, nsw, sys_status, status);
 363
 364out:
 365	spin_unlock(&nn->nn_lock);
 366	return;
 367}
 368
 369static void o2net_complete_nodes_nsw(struct o2net_node *nn)
 370{
 371	struct o2net_status_wait *nsw, *tmp;
 372	unsigned int num_kills = 0;
 373
 374	assert_spin_locked(&nn->nn_lock);
 375
 376	list_for_each_entry_safe(nsw, tmp, &nn->nn_status_list, ns_node_item) {
 377		o2net_complete_nsw_locked(nn, nsw, O2NET_ERR_DIED, 0);
 378		num_kills++;
 379	}
 380
 381	mlog(0, "completed %d messages for node %u\n", num_kills,
 382	     o2net_num_from_nn(nn));
 383}
 384
 385static int o2net_nsw_completed(struct o2net_node *nn,
 386			       struct o2net_status_wait *nsw)
 387{
 388	int completed;
 389	spin_lock(&nn->nn_lock);
 390	completed = list_empty(&nsw->ns_node_item);
 391	spin_unlock(&nn->nn_lock);
 392	return completed;
 393}
 394
 395/* ------------------------------------------------------------ */
 396
 397static void sc_kref_release(struct kref *kref)
 398{
 399	struct o2net_sock_container *sc = container_of(kref,
 400					struct o2net_sock_container, sc_kref);
 401	BUG_ON(timer_pending(&sc->sc_idle_timeout));
 402
 403	sclog(sc, "releasing\n");
 404
 405	if (sc->sc_sock) {
 406		sock_release(sc->sc_sock);
 407		sc->sc_sock = NULL;
 408	}
 409
 410	o2nm_undepend_item(&sc->sc_node->nd_item);
 411	o2nm_node_put(sc->sc_node);
 412	sc->sc_node = NULL;
 413
 414	o2net_debug_del_sc(sc);
 415	kfree(sc);
 416}
 417
 418static void sc_put(struct o2net_sock_container *sc)
 419{
 420	sclog(sc, "put\n");
 421	kref_put(&sc->sc_kref, sc_kref_release);
 422}
 423static void sc_get(struct o2net_sock_container *sc)
 424{
 425	sclog(sc, "get\n");
 426	kref_get(&sc->sc_kref);
 427}
 428static struct o2net_sock_container *sc_alloc(struct o2nm_node *node)
 429{
 430	struct o2net_sock_container *sc, *ret = NULL;
 431	struct page *page = NULL;
 432	int status = 0;
 433
 434	page = alloc_page(GFP_NOFS);
 435	sc = kzalloc(sizeof(*sc), GFP_NOFS);
 436	if (sc == NULL || page == NULL)
 437		goto out;
 438
 439	kref_init(&sc->sc_kref);
 440	o2nm_node_get(node);
 441	sc->sc_node = node;
 442
 443	/* pin the node item of the remote node */
 444	status = o2nm_depend_item(&node->nd_item);
 445	if (status) {
 446		mlog_errno(status);
 447		o2nm_node_put(node);
 448		goto out;
 449	}
 450	INIT_WORK(&sc->sc_connect_work, o2net_sc_connect_completed);
 451	INIT_WORK(&sc->sc_rx_work, o2net_rx_until_empty);
 452	INIT_WORK(&sc->sc_shutdown_work, o2net_shutdown_sc);
 453	INIT_DELAYED_WORK(&sc->sc_keepalive_work, o2net_sc_send_keep_req);
 454
 455	init_timer(&sc->sc_idle_timeout);
 456	sc->sc_idle_timeout.function = o2net_idle_timer;
 457	sc->sc_idle_timeout.data = (unsigned long)sc;
 458
 459	sclog(sc, "alloced\n");
 460
 461	ret = sc;
 462	sc->sc_page = page;
 463	o2net_debug_add_sc(sc);
 464	sc = NULL;
 465	page = NULL;
 466
 467out:
 468	if (page)
 469		__free_page(page);
 470	kfree(sc);
 471
 472	return ret;
 473}
 474
 475/* ------------------------------------------------------------ */
 476
 477static void o2net_sc_queue_work(struct o2net_sock_container *sc,
 478				struct work_struct *work)
 479{
 480	sc_get(sc);
 481	if (!queue_work(o2net_wq, work))
 482		sc_put(sc);
 483}
 484static void o2net_sc_queue_delayed_work(struct o2net_sock_container *sc,
 485					struct delayed_work *work,
 486					int delay)
 487{
 488	sc_get(sc);
 489	if (!queue_delayed_work(o2net_wq, work, delay))
 490		sc_put(sc);
 491}
 492static void o2net_sc_cancel_delayed_work(struct o2net_sock_container *sc,
 493					 struct delayed_work *work)
 494{
 495	if (cancel_delayed_work(work))
 496		sc_put(sc);
 497}
 498
 499static atomic_t o2net_connected_peers = ATOMIC_INIT(0);
 500
 501int o2net_num_connected_peers(void)
 502{
 503	return atomic_read(&o2net_connected_peers);
 504}
 505
 506static void o2net_set_nn_state(struct o2net_node *nn,
 507			       struct o2net_sock_container *sc,
 508			       unsigned valid, int err)
 509{
 510	int was_valid = nn->nn_sc_valid;
 511	int was_err = nn->nn_persistent_error;
 512	struct o2net_sock_container *old_sc = nn->nn_sc;
 513
 514	assert_spin_locked(&nn->nn_lock);
 515
 516	if (old_sc && !sc)
 517		atomic_dec(&o2net_connected_peers);
 518	else if (!old_sc && sc)
 519		atomic_inc(&o2net_connected_peers);
 520
 521	/* the node num comparison and single connect/accept path should stop
 522	 * an non-null sc from being overwritten with another */
 523	BUG_ON(sc && nn->nn_sc && nn->nn_sc != sc);
 524	mlog_bug_on_msg(err && valid, "err %d valid %u\n", err, valid);
 525	mlog_bug_on_msg(valid && !sc, "valid %u sc %p\n", valid, sc);
 526
 527	if (was_valid && !valid && err == 0)
 528		err = -ENOTCONN;
 529
 530	mlog(ML_CONN, "node %u sc: %p -> %p, valid %u -> %u, err %d -> %d\n",
 531	     o2net_num_from_nn(nn), nn->nn_sc, sc, nn->nn_sc_valid, valid,
 532	     nn->nn_persistent_error, err);
 533
 534	nn->nn_sc = sc;
 535	nn->nn_sc_valid = valid ? 1 : 0;
 536	nn->nn_persistent_error = err;
 537
 538	/* mirrors o2net_tx_can_proceed() */
 539	if (nn->nn_persistent_error || nn->nn_sc_valid)
 540		wake_up(&nn->nn_sc_wq);
 541
 542	if (!was_err && nn->nn_persistent_error) {
 543		o2quo_conn_err(o2net_num_from_nn(nn));
 544		queue_delayed_work(o2net_wq, &nn->nn_still_up,
 545				   msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
 546	}
 547
 548	if (was_valid && !valid) {
 549		printk(KERN_NOTICE "o2net: No longer connected to "
 550		       SC_NODEF_FMT "\n", SC_NODEF_ARGS(old_sc));
 551		o2net_complete_nodes_nsw(nn);
 552	}
 553
 554	if (!was_valid && valid) {
 555		o2quo_conn_up(o2net_num_from_nn(nn));
 556		cancel_delayed_work(&nn->nn_connect_expired);
 557		printk(KERN_NOTICE "o2net: %s " SC_NODEF_FMT "\n",
 558		       o2nm_this_node() > sc->sc_node->nd_num ?
 559		       "Connected to" : "Accepted connection from",
 560		       SC_NODEF_ARGS(sc));
 561	}
 562
 563	/* trigger the connecting worker func as long as we're not valid,
 564	 * it will back off if it shouldn't connect.  This can be called
 565	 * from node config teardown and so needs to be careful about
 566	 * the work queue actually being up. */
 567	if (!valid && o2net_wq) {
 568		unsigned long delay;
 569		/* delay if we're within a RECONNECT_DELAY of the
 570		 * last attempt */
 571		delay = (nn->nn_last_connect_attempt +
 572			 msecs_to_jiffies(o2net_reconnect_delay()))
 573			- jiffies;
 574		if (delay > msecs_to_jiffies(o2net_reconnect_delay()))
 575			delay = 0;
 576		mlog(ML_CONN, "queueing conn attempt in %lu jiffies\n", delay);
 577		queue_delayed_work(o2net_wq, &nn->nn_connect_work, delay);
 578
 579		/*
 580		 * Delay the expired work after idle timeout.
 581		 *
 582		 * We might have lots of failed connection attempts that run
 583		 * through here but we only cancel the connect_expired work when
 584		 * a connection attempt succeeds.  So only the first enqueue of
 585		 * the connect_expired work will do anything.  The rest will see
 586		 * that it's already queued and do nothing.
 587		 */
 588		delay += msecs_to_jiffies(o2net_idle_timeout());
 589		queue_delayed_work(o2net_wq, &nn->nn_connect_expired, delay);
 590	}
 591
 592	/* keep track of the nn's sc ref for the caller */
 593	if ((old_sc == NULL) && sc)
 594		sc_get(sc);
 595	if (old_sc && (old_sc != sc)) {
 596		o2net_sc_queue_work(old_sc, &old_sc->sc_shutdown_work);
 597		sc_put(old_sc);
 598	}
 599}
 600
 601/* see o2net_register_callbacks() */
 602static void o2net_data_ready(struct sock *sk, int bytes)
 603{
 604	void (*ready)(struct sock *sk, int bytes);
 605
 606	read_lock(&sk->sk_callback_lock);
 607	if (sk->sk_user_data) {
 608		struct o2net_sock_container *sc = sk->sk_user_data;
 609		sclog(sc, "data_ready hit\n");
 610		o2net_set_data_ready_time(sc);
 611		o2net_sc_queue_work(sc, &sc->sc_rx_work);
 612		ready = sc->sc_data_ready;
 613	} else {
 614		ready = sk->sk_data_ready;
 615	}
 616	read_unlock(&sk->sk_callback_lock);
 617
 618	ready(sk, bytes);
 619}
 620
 621/* see o2net_register_callbacks() */
 622static void o2net_state_change(struct sock *sk)
 623{
 624	void (*state_change)(struct sock *sk);
 625	struct o2net_sock_container *sc;
 626
 627	read_lock(&sk->sk_callback_lock);
 628	sc = sk->sk_user_data;
 629	if (sc == NULL) {
 630		state_change = sk->sk_state_change;
 631		goto out;
 632	}
 633
 634	sclog(sc, "state_change to %d\n", sk->sk_state);
 635
 636	state_change = sc->sc_state_change;
 637
 638	switch(sk->sk_state) {
 639		/* ignore connecting sockets as they make progress */
 640		case TCP_SYN_SENT:
 641		case TCP_SYN_RECV:
 642			break;
 643		case TCP_ESTABLISHED:
 644			o2net_sc_queue_work(sc, &sc->sc_connect_work);
 645			break;
 646		default:
 647			printk(KERN_INFO "o2net: Connection to " SC_NODEF_FMT
 648			      " shutdown, state %d\n",
 649			      SC_NODEF_ARGS(sc), sk->sk_state);
 650			o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
 651			break;
 652	}
 653out:
 654	read_unlock(&sk->sk_callback_lock);
 655	state_change(sk);
 656}
 657
 658/*
 659 * we register callbacks so we can queue work on events before calling
 660 * the original callbacks.  our callbacks our careful to test user_data
 661 * to discover when they've reaced with o2net_unregister_callbacks().
 662 */
 663static void o2net_register_callbacks(struct sock *sk,
 664				     struct o2net_sock_container *sc)
 665{
 666	write_lock_bh(&sk->sk_callback_lock);
 667
 668	/* accepted sockets inherit the old listen socket data ready */
 669	if (sk->sk_data_ready == o2net_listen_data_ready) {
 670		sk->sk_data_ready = sk->sk_user_data;
 671		sk->sk_user_data = NULL;
 672	}
 673
 674	BUG_ON(sk->sk_user_data != NULL);
 675	sk->sk_user_data = sc;
 676	sc_get(sc);
 677
 678	sc->sc_data_ready = sk->sk_data_ready;
 679	sc->sc_state_change = sk->sk_state_change;
 680	sk->sk_data_ready = o2net_data_ready;
 681	sk->sk_state_change = o2net_state_change;
 682
 683	mutex_init(&sc->sc_send_lock);
 684
 685	write_unlock_bh(&sk->sk_callback_lock);
 686}
 687
 688static int o2net_unregister_callbacks(struct sock *sk,
 689			           struct o2net_sock_container *sc)
 690{
 691	int ret = 0;
 692
 693	write_lock_bh(&sk->sk_callback_lock);
 694	if (sk->sk_user_data == sc) {
 695		ret = 1;
 696		sk->sk_user_data = NULL;
 697		sk->sk_data_ready = sc->sc_data_ready;
 698		sk->sk_state_change = sc->sc_state_change;
 699	}
 700	write_unlock_bh(&sk->sk_callback_lock);
 701
 702	return ret;
 703}
 704
 705/*
 706 * this is a little helper that is called by callers who have seen a problem
 707 * with an sc and want to detach it from the nn if someone already hasn't beat
 708 * them to it.  if an error is given then the shutdown will be persistent
 709 * and pending transmits will be canceled.
 710 */
 711static void o2net_ensure_shutdown(struct o2net_node *nn,
 712			           struct o2net_sock_container *sc,
 713				   int err)
 714{
 715	spin_lock(&nn->nn_lock);
 716	if (nn->nn_sc == sc)
 717		o2net_set_nn_state(nn, NULL, 0, err);
 718	spin_unlock(&nn->nn_lock);
 719}
 720
 721/*
 722 * This work queue function performs the blocking parts of socket shutdown.  A
 723 * few paths lead here.  set_nn_state will trigger this callback if it sees an
 724 * sc detached from the nn.  state_change will also trigger this callback
 725 * directly when it sees errors.  In that case we need to call set_nn_state
 726 * ourselves as state_change couldn't get the nn_lock and call set_nn_state
 727 * itself.
 728 */
 729static void o2net_shutdown_sc(struct work_struct *work)
 730{
 731	struct o2net_sock_container *sc =
 732		container_of(work, struct o2net_sock_container,
 733			     sc_shutdown_work);
 734	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
 735
 736	sclog(sc, "shutting down\n");
 737
 738	/* drop the callbacks ref and call shutdown only once */
 739	if (o2net_unregister_callbacks(sc->sc_sock->sk, sc)) {
 740		/* we shouldn't flush as we're in the thread, the
 741		 * races with pending sc work structs are harmless */
 742		del_timer_sync(&sc->sc_idle_timeout);
 743		o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
 744		sc_put(sc);
 745		kernel_sock_shutdown(sc->sc_sock, SHUT_RDWR);
 746	}
 747
 748	/* not fatal so failed connects before the other guy has our
 749	 * heartbeat can be retried */
 750	o2net_ensure_shutdown(nn, sc, 0);
 751	sc_put(sc);
 752}
 753
 754/* ------------------------------------------------------------ */
 755
 756static int o2net_handler_cmp(struct o2net_msg_handler *nmh, u32 msg_type,
 757			     u32 key)
 758{
 759	int ret = memcmp(&nmh->nh_key, &key, sizeof(key));
 760
 761	if (ret == 0)
 762		ret = memcmp(&nmh->nh_msg_type, &msg_type, sizeof(msg_type));
 763
 764	return ret;
 765}
 766
 767static struct o2net_msg_handler *
 768o2net_handler_tree_lookup(u32 msg_type, u32 key, struct rb_node ***ret_p,
 769			  struct rb_node **ret_parent)
 770{
 771        struct rb_node **p = &o2net_handler_tree.rb_node;
 772        struct rb_node *parent = NULL;
 773	struct o2net_msg_handler *nmh, *ret = NULL;
 774	int cmp;
 775
 776        while (*p) {
 777                parent = *p;
 778                nmh = rb_entry(parent, struct o2net_msg_handler, nh_node);
 779		cmp = o2net_handler_cmp(nmh, msg_type, key);
 780
 781                if (cmp < 0)
 782                        p = &(*p)->rb_left;
 783                else if (cmp > 0)
 784                        p = &(*p)->rb_right;
 785                else {
 786			ret = nmh;
 787                        break;
 788		}
 789        }
 790
 791        if (ret_p != NULL)
 792                *ret_p = p;
 793        if (ret_parent != NULL)
 794                *ret_parent = parent;
 795
 796        return ret;
 797}
 798
 799static void o2net_handler_kref_release(struct kref *kref)
 800{
 801	struct o2net_msg_handler *nmh;
 802	nmh = container_of(kref, struct o2net_msg_handler, nh_kref);
 803
 804	kfree(nmh);
 805}
 806
 807static void o2net_handler_put(struct o2net_msg_handler *nmh)
 808{
 809	kref_put(&nmh->nh_kref, o2net_handler_kref_release);
 810}
 811
 812/* max_len is protection for the handler func.  incoming messages won't
 813 * be given to the handler if their payload is longer than the max. */
 814int o2net_register_handler(u32 msg_type, u32 key, u32 max_len,
 815			   o2net_msg_handler_func *func, void *data,
 816			   o2net_post_msg_handler_func *post_func,
 817			   struct list_head *unreg_list)
 818{
 819	struct o2net_msg_handler *nmh = NULL;
 820	struct rb_node **p, *parent;
 821	int ret = 0;
 822
 823	if (max_len > O2NET_MAX_PAYLOAD_BYTES) {
 824		mlog(0, "max_len for message handler out of range: %u\n",
 825			max_len);
 826		ret = -EINVAL;
 827		goto out;
 828	}
 829
 830	if (!msg_type) {
 831		mlog(0, "no message type provided: %u, %p\n", msg_type, func);
 832		ret = -EINVAL;
 833		goto out;
 834
 835	}
 836	if (!func) {
 837		mlog(0, "no message handler provided: %u, %p\n",
 838		       msg_type, func);
 839		ret = -EINVAL;
 840		goto out;
 841	}
 842
 843       	nmh = kzalloc(sizeof(struct o2net_msg_handler), GFP_NOFS);
 844	if (nmh == NULL) {
 845		ret = -ENOMEM;
 846		goto out;
 847	}
 848
 849	nmh->nh_func = func;
 850	nmh->nh_func_data = data;
 851	nmh->nh_post_func = post_func;
 852	nmh->nh_msg_type = msg_type;
 853	nmh->nh_max_len = max_len;
 854	nmh->nh_key = key;
 855	/* the tree and list get this ref.. they're both removed in
 856	 * unregister when this ref is dropped */
 857	kref_init(&nmh->nh_kref);
 858	INIT_LIST_HEAD(&nmh->nh_unregister_item);
 859
 860	write_lock(&o2net_handler_lock);
 861	if (o2net_handler_tree_lookup(msg_type, key, &p, &parent))
 862		ret = -EEXIST;
 863	else {
 864	        rb_link_node(&nmh->nh_node, parent, p);
 865		rb_insert_color(&nmh->nh_node, &o2net_handler_tree);
 866		list_add_tail(&nmh->nh_unregister_item, unreg_list);
 867
 868		mlog(ML_TCP, "registered handler func %p type %u key %08x\n",
 869		     func, msg_type, key);
 870		/* we've had some trouble with handlers seemingly vanishing. */
 871		mlog_bug_on_msg(o2net_handler_tree_lookup(msg_type, key, &p,
 872							  &parent) == NULL,
 873			        "couldn't find handler we *just* registerd "
 874				"for type %u key %08x\n", msg_type, key);
 875	}
 876	write_unlock(&o2net_handler_lock);
 877	if (ret)
 878		goto out;
 879
 880out:
 881	if (ret)
 882		kfree(nmh);
 883
 884	return ret;
 885}
 886EXPORT_SYMBOL_GPL(o2net_register_handler);
 887
 888void o2net_unregister_handler_list(struct list_head *list)
 889{
 890	struct o2net_msg_handler *nmh, *n;
 891
 892	write_lock(&o2net_handler_lock);
 893	list_for_each_entry_safe(nmh, n, list, nh_unregister_item) {
 894		mlog(ML_TCP, "unregistering handler func %p type %u key %08x\n",
 895		     nmh->nh_func, nmh->nh_msg_type, nmh->nh_key);
 896		rb_erase(&nmh->nh_node, &o2net_handler_tree);
 897		list_del_init(&nmh->nh_unregister_item);
 898		kref_put(&nmh->nh_kref, o2net_handler_kref_release);
 899	}
 900	write_unlock(&o2net_handler_lock);
 901}
 902EXPORT_SYMBOL_GPL(o2net_unregister_handler_list);
 903
 904static struct o2net_msg_handler *o2net_handler_get(u32 msg_type, u32 key)
 905{
 906	struct o2net_msg_handler *nmh;
 907
 908	read_lock(&o2net_handler_lock);
 909	nmh = o2net_handler_tree_lookup(msg_type, key, NULL, NULL);
 910	if (nmh)
 911		kref_get(&nmh->nh_kref);
 912	read_unlock(&o2net_handler_lock);
 913
 914	return nmh;
 915}
 916
 917/* ------------------------------------------------------------ */
 918
 919static int o2net_recv_tcp_msg(struct socket *sock, void *data, size_t len)
 920{
 921	int ret;
 922	mm_segment_t oldfs;
 923	struct kvec vec = {
 924		.iov_len = len,
 925		.iov_base = data,
 926	};
 927	struct msghdr msg = {
 928		.msg_iovlen = 1,
 929		.msg_iov = (struct iovec *)&vec,
 930       		.msg_flags = MSG_DONTWAIT,
 931	};
 932
 933	oldfs = get_fs();
 934	set_fs(get_ds());
 935	ret = sock_recvmsg(sock, &msg, len, msg.msg_flags);
 936	set_fs(oldfs);
 937
 938	return ret;
 939}
 940
 941static int o2net_send_tcp_msg(struct socket *sock, struct kvec *vec,
 942			      size_t veclen, size_t total)
 943{
 944	int ret;
 945	mm_segment_t oldfs;
 946	struct msghdr msg = {
 947		.msg_iov = (struct iovec *)vec,
 948		.msg_iovlen = veclen,
 949	};
 950
 951	if (sock == NULL) {
 952		ret = -EINVAL;
 953		goto out;
 954	}
 955
 956	oldfs = get_fs();
 957	set_fs(get_ds());
 958	ret = sock_sendmsg(sock, &msg, total);
 959	set_fs(oldfs);
 960	if (ret != total) {
 961		mlog(ML_ERROR, "sendmsg returned %d instead of %zu\n", ret,
 962		     total);
 963		if (ret >= 0)
 964			ret = -EPIPE; /* should be smarter, I bet */
 965		goto out;
 966	}
 967
 968	ret = 0;
 969out:
 970	if (ret < 0)
 971		mlog(0, "returning error: %d\n", ret);
 972	return ret;
 973}
 974
 975static void o2net_sendpage(struct o2net_sock_container *sc,
 976			   void *kmalloced_virt,
 977			   size_t size)
 978{
 979	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
 980	ssize_t ret;
 981
 982	while (1) {
 983		mutex_lock(&sc->sc_send_lock);
 984		ret = sc->sc_sock->ops->sendpage(sc->sc_sock,
 985						 virt_to_page(kmalloced_virt),
 986						 (long)kmalloced_virt & ~PAGE_MASK,
 987						 size, MSG_DONTWAIT);
 988		mutex_unlock(&sc->sc_send_lock);
 989		if (ret == size)
 990			break;
 991		if (ret == (ssize_t)-EAGAIN) {
 992			mlog(0, "sendpage of size %zu to " SC_NODEF_FMT
 993			     " returned EAGAIN\n", size, SC_NODEF_ARGS(sc));
 994			cond_resched();
 995			continue;
 996		}
 997		mlog(ML_ERROR, "sendpage of size %zu to " SC_NODEF_FMT
 998		     " failed with %zd\n", size, SC_NODEF_ARGS(sc), ret);
 999		o2net_ensure_shutdown(nn, sc, 0);
1000		break;
1001	}
1002}
1003
1004static void o2net_init_msg(struct o2net_msg *msg, u16 data_len, u16 msg_type, u32 key)
1005{
1006	memset(msg, 0, sizeof(struct o2net_msg));
1007	msg->magic = cpu_to_be16(O2NET_MSG_MAGIC);
1008	msg->data_len = cpu_to_be16(data_len);
1009	msg->msg_type = cpu_to_be16(msg_type);
1010	msg->sys_status = cpu_to_be32(O2NET_ERR_NONE);
1011	msg->status = 0;
1012	msg->key = cpu_to_be32(key);
1013}
1014
1015static int o2net_tx_can_proceed(struct o2net_node *nn,
1016			        struct o2net_sock_container **sc_ret,
1017				int *error)
1018{
1019	int ret = 0;
1020
1021	spin_lock(&nn->nn_lock);
1022	if (nn->nn_persistent_error) {
1023		ret = 1;
1024		*sc_ret = NULL;
1025		*error = nn->nn_persistent_error;
1026	} else if (nn->nn_sc_valid) {
1027		kref_get(&nn->nn_sc->sc_kref);
1028
1029		ret = 1;
1030		*sc_ret = nn->nn_sc;
1031		*error = 0;
1032	}
1033	spin_unlock(&nn->nn_lock);
1034
1035	return ret;
1036}
1037
1038/* Get a map of all nodes to which this node is currently connected to */
1039void o2net_fill_node_map(unsigned long *map, unsigned bytes)
1040{
1041	struct o2net_sock_container *sc;
1042	int node, ret;
1043
1044	BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long)));
1045
1046	memset(map, 0, bytes);
1047	for (node = 0; node < O2NM_MAX_NODES; ++node) {
1048		o2net_tx_can_proceed(o2net_nn_from_num(node), &sc, &ret);
1049		if (!ret) {
1050			set_bit(node, map);
1051			sc_put(sc);
1052		}
1053	}
1054}
1055EXPORT_SYMBOL_GPL(o2net_fill_node_map);
1056
1057int o2net_send_message_vec(u32 msg_type, u32 key, struct kvec *caller_vec,
1058			   size_t caller_veclen, u8 target_node, int *status)
1059{
1060	int ret = 0;
1061	struct o2net_msg *msg = NULL;
1062	size_t veclen, caller_bytes = 0;
1063	struct kvec *vec = NULL;
1064	struct o2net_sock_container *sc = NULL;
1065	struct o2net_node *nn = o2net_nn_from_num(target_node);
1066	struct o2net_status_wait nsw = {
1067		.ns_node_item = LIST_HEAD_INIT(nsw.ns_node_item),
1068	};
1069	struct o2net_send_tracking nst;
1070
1071	o2net_init_nst(&nst, msg_type, key, current, target_node);
1072
1073	if (o2net_wq == NULL) {
1074		mlog(0, "attempt to tx without o2netd running\n");
1075		ret = -ESRCH;
1076		goto out;
1077	}
1078
1079	if (caller_veclen == 0) {
1080		mlog(0, "bad kvec array length\n");
1081		ret = -EINVAL;
1082		goto out;
1083	}
1084
1085	caller_bytes = iov_length((struct iovec *)caller_vec, caller_veclen);
1086	if (caller_bytes > O2NET_MAX_PAYLOAD_BYTES) {
1087		mlog(0, "total payload len %zu too large\n", caller_bytes);
1088		ret = -EINVAL;
1089		goto out;
1090	}
1091
1092	if (target_node == o2nm_this_node()) {
1093		ret = -ELOOP;
1094		goto out;
1095	}
1096
1097	o2net_debug_add_nst(&nst);
1098
1099	o2net_set_nst_sock_time(&nst);
1100
1101	wait_event(nn->nn_sc_wq, o2net_tx_can_proceed(nn, &sc, &ret));
1102	if (ret)
1103		goto out;
1104
1105	o2net_set_nst_sock_container(&nst, sc);
1106
1107	veclen = caller_veclen + 1;
1108	vec = kmalloc(sizeof(struct kvec) * veclen, GFP_ATOMIC);
1109	if (vec == NULL) {
1110		mlog(0, "failed to %zu element kvec!\n", veclen);
1111		ret = -ENOMEM;
1112		goto out;
1113	}
1114
1115	msg = kmalloc(sizeof(struct o2net_msg), GFP_ATOMIC);
1116	if (!msg) {
1117		mlog(0, "failed to allocate a o2net_msg!\n");
1118		ret = -ENOMEM;
1119		goto out;
1120	}
1121
1122	o2net_init_msg(msg, caller_bytes, msg_type, key);
1123
1124	vec[0].iov_len = sizeof(struct o2net_msg);
1125	vec[0].iov_base = msg;
1126	memcpy(&vec[1], caller_vec, caller_veclen * sizeof(struct kvec));
1127
1128	ret = o2net_prep_nsw(nn, &nsw);
1129	if (ret)
1130		goto out;
1131
1132	msg->msg_num = cpu_to_be32(nsw.ns_id);
1133	o2net_set_nst_msg_id(&nst, nsw.ns_id);
1134
1135	o2net_set_nst_send_time(&nst);
1136
1137	/* finally, convert the message header to network byte-order
1138	 * and send */
1139	mutex_lock(&sc->sc_send_lock);
1140	ret = o2net_send_tcp_msg(sc->sc_sock, vec, veclen,
1141				 sizeof(struct o2net_msg) + caller_bytes);
1142	mutex_unlock(&sc->sc_send_lock);
1143	msglog(msg, "sending returned %d\n", ret);
1144	if (ret < 0) {
1145		mlog(0, "error returned from o2net_send_tcp_msg=%d\n", ret);
1146		goto out;
1147	}
1148
1149	/* wait on other node's handler */
1150	o2net_set_nst_status_time(&nst);
1151	wait_event(nsw.ns_wq, o2net_nsw_completed(nn, &nsw));
1152
1153	o2net_update_send_stats(&nst, sc);
1154
1155	/* Note that we avoid overwriting the callers status return
1156	 * variable if a system error was reported on the other
1157	 * side. Callers beware. */
1158	ret = o2net_sys_err_to_errno(nsw.ns_sys_status);
1159	if (status && !ret)
1160		*status = nsw.ns_status;
1161
1162	mlog(0, "woken, returning system status %d, user status %d\n",
1163	     ret, nsw.ns_status);
1164out:
1165	o2net_debug_del_nst(&nst); /* must be before dropping sc and node */
1166	if (sc)
1167		sc_put(sc);
1168	if (vec)
1169		kfree(vec);
1170	if (msg)
1171		kfree(msg);
1172	o2net_complete_nsw(nn, &nsw, 0, 0, 0);
1173	return ret;
1174}
1175EXPORT_SYMBOL_GPL(o2net_send_message_vec);
1176
1177int o2net_send_message(u32 msg_type, u32 key, void *data, u32 len,
1178		       u8 target_node, int *status)
1179{
1180	struct kvec vec = {
1181		.iov_base = data,
1182		.iov_len = len,
1183	};
1184	return o2net_send_message_vec(msg_type, key, &vec, 1,
1185				      target_node, status);
1186}
1187EXPORT_SYMBOL_GPL(o2net_send_message);
1188
1189static int o2net_send_status_magic(struct socket *sock, struct o2net_msg *hdr,
1190				   enum o2net_system_error syserr, int err)
1191{
1192	struct kvec vec = {
1193		.iov_base = hdr,
1194		.iov_len = sizeof(struct o2net_msg),
1195	};
1196
1197	BUG_ON(syserr >= O2NET_ERR_MAX);
1198
1199	/* leave other fields intact from the incoming message, msg_num
1200	 * in particular */
1201	hdr->sys_status = cpu_to_be32(syserr);
1202	hdr->status = cpu_to_be32(err);
1203	hdr->magic = cpu_to_be16(O2NET_MSG_STATUS_MAGIC);  // twiddle the magic
1204	hdr->data_len = 0;
1205
1206	msglog(hdr, "about to send status magic %d\n", err);
1207	/* hdr has been in host byteorder this whole time */
1208	return o2net_send_tcp_msg(sock, &vec, 1, sizeof(struct o2net_msg));
1209}
1210
1211/* this returns -errno if the header was unknown or too large, etc.
1212 * after this is called the buffer us reused for the next message */
1213static int o2net_process_message(struct o2net_sock_container *sc,
1214				 struct o2net_msg *hdr)
1215{
1216	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1217	int ret = 0, handler_status;
1218	enum  o2net_system_error syserr;
1219	struct o2net_msg_handler *nmh = NULL;
1220	void *ret_data = NULL;
1221
1222	msglog(hdr, "processing message\n");
1223
1224	o2net_sc_postpone_idle(sc);
1225
1226	switch(be16_to_cpu(hdr->magic)) {
1227		case O2NET_MSG_STATUS_MAGIC:
1228			/* special type for returning message status */
1229			o2net_complete_nsw(nn, NULL,
1230					   be32_to_cpu(hdr->msg_num),
1231					   be32_to_cpu(hdr->sys_status),
1232					   be32_to_cpu(hdr->status));
1233			goto out;
1234		case O2NET_MSG_KEEP_REQ_MAGIC:
1235			o2net_sendpage(sc, o2net_keep_resp,
1236				       sizeof(*o2net_keep_resp));
1237			goto out;
1238		case O2NET_MSG_KEEP_RESP_MAGIC:
1239			goto out;
1240		case O2NET_MSG_MAGIC:
1241			break;
1242		default:
1243			msglog(hdr, "bad magic\n");
1244			ret = -EINVAL;
1245			goto out;
1246			break;
1247	}
1248
1249	/* find a handler for it */
1250	handler_status = 0;
1251	nmh = o2net_handler_get(be16_to_cpu(hdr->msg_type),
1252				be32_to_cpu(hdr->key));
1253	if (!nmh) {
1254		mlog(ML_TCP, "couldn't find handler for type %u key %08x\n",
1255		     be16_to_cpu(hdr->msg_type), be32_to_cpu(hdr->key));
1256		syserr = O2NET_ERR_NO_HNDLR;
1257		goto out_respond;
1258	}
1259
1260	syserr = O2NET_ERR_NONE;
1261
1262	if (be16_to_cpu(hdr->data_len) > nmh->nh_max_len)
1263		syserr = O2NET_ERR_OVERFLOW;
1264
1265	if (syserr != O2NET_ERR_NONE)
1266		goto out_respond;
1267
1268	o2net_set_func_start_time(sc);
1269	sc->sc_msg_key = be32_to_cpu(hdr->key);
1270	sc->sc_msg_type = be16_to_cpu(hdr->msg_type);
1271	handler_status = (nmh->nh_func)(hdr, sizeof(struct o2net_msg) +
1272					     be16_to_cpu(hdr->data_len),
1273					nmh->nh_func_data, &ret_data);
1274	o2net_set_func_stop_time(sc);
1275
1276	o2net_update_recv_stats(sc);
1277
1278out_respond:
1279	/* this destroys the hdr, so don't use it after this */
1280	mutex_lock(&sc->sc_send_lock);
1281	ret = o2net_send_status_magic(sc->sc_sock, hdr, syserr,
1282				      handler_status);
1283	mutex_unlock(&sc->sc_send_lock);
1284	hdr = NULL;
1285	mlog(0, "sending handler status %d, syserr %d returned %d\n",
1286	     handler_status, syserr, ret);
1287
1288	if (nmh) {
1289		BUG_ON(ret_data != NULL && nmh->nh_post_func == NULL);
1290		if (nmh->nh_post_func)
1291			(nmh->nh_post_func)(handler_status, nmh->nh_func_data,
1292					    ret_data);
1293	}
1294
1295out:
1296	if (nmh)
1297		o2net_handler_put(nmh);
1298	return ret;
1299}
1300
1301static int o2net_check_handshake(struct o2net_sock_container *sc)
1302{
1303	struct o2net_handshake *hand = page_address(sc->sc_page);
1304	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1305
1306	if (hand->protocol_version != cpu_to_be64(O2NET_PROTOCOL_VERSION)) {
1307		printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " Advertised net "
1308		       "protocol version %llu but %llu is required. "
1309		       "Disconnecting.\n", SC_NODEF_ARGS(sc),
1310		       (unsigned long long)be64_to_cpu(hand->protocol_version),
1311		       O2NET_PROTOCOL_VERSION);
1312
1313		/* don't bother reconnecting if its the wrong version. */
1314		o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1315		return -1;
1316	}
1317
1318	/*
1319	 * Ensure timeouts are consistent with other nodes, otherwise
1320	 * we can end up with one node thinking that the other must be down,
1321	 * but isn't. This can ultimately cause corruption.
1322	 */
1323	if (be32_to_cpu(hand->o2net_idle_timeout_ms) !=
1324				o2net_idle_timeout()) {
1325		printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a network "
1326		       "idle timeout of %u ms, but we use %u ms locally. "
1327		       "Disconnecting.\n", SC_NODEF_ARGS(sc),
1328		       be32_to_cpu(hand->o2net_idle_timeout_ms),
1329		       o2net_idle_timeout());
1330		o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1331		return -1;
1332	}
1333
1334	if (be32_to_cpu(hand->o2net_keepalive_delay_ms) !=
1335			o2net_keepalive_delay()) {
1336		printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a keepalive "
1337		       "delay of %u ms, but we use %u ms locally. "
1338		       "Disconnecting.\n", SC_NODEF_ARGS(sc),
1339		       be32_to_cpu(hand->o2net_keepalive_delay_ms),
1340		       o2net_keepalive_delay());
1341		o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1342		return -1;
1343	}
1344
1345	if (be32_to_cpu(hand->o2hb_heartbeat_timeout_ms) !=
1346			O2HB_MAX_WRITE_TIMEOUT_MS) {
1347		printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a heartbeat "
1348		       "timeout of %u ms, but we use %u ms locally. "
1349		       "Disconnecting.\n", SC_NODEF_ARGS(sc),
1350		       be32_to_cpu(hand->o2hb_heartbeat_timeout_ms),
1351		       O2HB_MAX_WRITE_TIMEOUT_MS);
1352		o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1353		return -1;
1354	}
1355
1356	sc->sc_handshake_ok = 1;
1357
1358	spin_lock(&nn->nn_lock);
1359	/* set valid and queue the idle timers only if it hasn't been
1360	 * shut down already */
1361	if (nn->nn_sc == sc) {
1362		o2net_sc_reset_idle_timer(sc);
1363		atomic_set(&nn->nn_timeout, 0);
1364		o2net_set_nn_state(nn, sc, 1, 0);
1365	}
1366	spin_unlock(&nn->nn_lock);
1367
1368	/* shift everything up as though it wasn't there */
1369	sc->sc_page_off -= sizeof(struct o2net_handshake);
1370	if (sc->sc_page_off)
1371		memmove(hand, hand + 1, sc->sc_page_off);
1372
1373	return 0;
1374}
1375
1376/* this demuxes the queued rx bytes into header or payload bits and calls
1377 * handlers as each full message is read off the socket.  it returns -error,
1378 * == 0 eof, or > 0 for progress made.*/
1379static int o2net_advance_rx(struct o2net_sock_container *sc)
1380{
1381	struct o2net_msg *hdr;
1382	int ret = 0;
1383	void *data;
1384	size_t datalen;
1385
1386	sclog(sc, "receiving\n");
1387	o2net_set_advance_start_time(sc);
1388
1389	if (unlikely(sc->sc_handshake_ok == 0)) {
1390		if(sc->sc_page_off < sizeof(struct o2net_handshake)) {
1391			data = page_address(sc->sc_page) + sc->sc_page_off;
1392			datalen = sizeof(struct o2net_handshake) - sc->sc_page_off;
1393			ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1394			if (ret > 0)
1395				sc->sc_page_off += ret;
1396		}
1397
1398		if (sc->sc_page_off == sizeof(struct o2net_handshake)) {
1399			o2net_check_handshake(sc);
1400			if (unlikely(sc->sc_handshake_ok == 0))
1401				ret = -EPROTO;
1402		}
1403		goto out;
1404	}
1405
1406	/* do we need more header? */
1407	if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1408		data = page_address(sc->sc_page) + sc->sc_page_off;
1409		datalen = sizeof(struct o2net_msg) - sc->sc_page_off;
1410		ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1411		if (ret > 0) {
1412			sc->sc_page_off += ret;
1413			/* only swab incoming here.. we can
1414			 * only get here once as we cross from
1415			 * being under to over */
1416			if (sc->sc_page_off == sizeof(struct o2net_msg)) {
1417				hdr = page_address(sc->sc_page);
1418				if (be16_to_cpu(hdr->data_len) >
1419				    O2NET_MAX_PAYLOAD_BYTES)
1420					ret = -EOVERFLOW;
1421			}
1422		}
1423		if (ret <= 0)
1424			goto out;
1425	}
1426
1427	if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1428		/* oof, still don't have a header */
1429		goto out;
1430	}
1431
1432	/* this was swabbed above when we first read it */
1433	hdr = page_address(sc->sc_page);
1434
1435	msglog(hdr, "at page_off %zu\n", sc->sc_page_off);
1436
1437	/* do we need more payload? */
1438	if (sc->sc_page_off - sizeof(struct o2net_msg) < be16_to_cpu(hdr->data_len)) {
1439		/* need more payload */
1440		data = page_address(sc->sc_page) + sc->sc_page_off;
1441		datalen = (sizeof(struct o2net_msg) + be16_to_cpu(hdr->data_len)) -
1442			  sc->sc_page_off;
1443		ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1444		if (ret > 0)
1445			sc->sc_page_off += ret;
1446		if (ret <= 0)
1447			goto out;
1448	}
1449
1450	if (sc->sc_page_off - sizeof(struct o2net_msg) == be16_to_cpu(hdr->data_len)) {
1451		/* we can only get here once, the first time we read
1452		 * the payload.. so set ret to progress if the handler
1453		 * works out. after calling this the message is toast */
1454		ret = o2net_process_message(sc, hdr);
1455		if (ret == 0)
1456			ret = 1;
1457		sc->sc_page_off = 0;
1458	}
1459
1460out:
1461	sclog(sc, "ret = %d\n", ret);
1462	o2net_set_advance_stop_time(sc);
1463	return ret;
1464}
1465
1466/* this work func is triggerd by data ready.  it reads until it can read no
1467 * more.  it interprets 0, eof, as fatal.  if data_ready hits while we're doing
1468 * our work the work struct will be marked and we'll be called again. */
1469static void o2net_rx_until_empty(struct work_struct *work)
1470{
1471	struct o2net_sock_container *sc =
1472		container_of(work, struct o2net_sock_container, sc_rx_work);
1473	int ret;
1474
1475	do {
1476		ret = o2net_advance_rx(sc);
1477	} while (ret > 0);
1478
1479	if (ret <= 0 && ret != -EAGAIN) {
1480		struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1481		sclog(sc, "saw error %d, closing\n", ret);
1482		/* not permanent so read failed handshake can retry */
1483		o2net_ensure_shutdown(nn, sc, 0);
1484	}
1485
1486	sc_put(sc);
1487}
1488
1489static int o2net_set_nodelay(struct socket *sock)
1490{
1491	int ret, val = 1;
1492	mm_segment_t oldfs;
1493
1494	oldfs = get_fs();
1495	set_fs(KERNEL_DS);
1496
1497	/*
1498	 * Dear unsuspecting programmer,
1499	 *
1500	 * Don't use sock_setsockopt() for SOL_TCP.  It doesn't check its level
1501	 * argument and assumes SOL_SOCKET so, say, your TCP_NODELAY will
1502	 * silently turn into SO_DEBUG.
1503	 *
1504	 * Yours,
1505	 * Keeper of hilariously fragile interfaces.
1506	 */
1507	ret = sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY,
1508				    (char __user *)&val, sizeof(val));
1509
1510	set_fs(oldfs);
1511	return ret;
1512}
1513
1514static void o2net_initialize_handshake(void)
1515{
1516	o2net_hand->o2hb_heartbeat_timeout_ms = cpu_to_be32(
1517		O2HB_MAX_WRITE_TIMEOUT_MS);
1518	o2net_hand->o2net_idle_timeout_ms = cpu_to_be32(o2net_idle_timeout());
1519	o2net_hand->o2net_keepalive_delay_ms = cpu_to_be32(
1520		o2net_keepalive_delay());
1521	o2net_hand->o2net_reconnect_delay_ms = cpu_to_be32(
1522		o2net_reconnect_delay());
1523}
1524
1525/* ------------------------------------------------------------ */
1526
1527/* called when a connect completes and after a sock is accepted.  the
1528 * rx path will see the response and mark the sc valid */
1529static void o2net_sc_connect_completed(struct work_struct *work)
1530{
1531	struct o2net_sock_container *sc =
1532		container_of(work, struct o2net_sock_container,
1533			     sc_connect_work);
1534
1535	mlog(ML_MSG, "sc sending handshake with ver %llu id %llx\n",
1536              (unsigned long long)O2NET_PROTOCOL_VERSION,
1537	      (unsigned long long)be64_to_cpu(o2net_hand->connector_id));
1538
1539	o2net_initialize_handshake();
1540	o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1541	sc_put(sc);
1542}
1543
1544/* this is called as a work_struct func. */
1545static void o2net_sc_send_keep_req(struct work_struct *work)
1546{
1547	struct o2net_sock_container *sc =
1548		container_of(work, struct o2net_sock_container,
1549			     sc_keepalive_work.work);
1550
1551	o2net_sendpage(sc, o2net_keep_req, sizeof(*o2net_keep_req));
1552	sc_put(sc);
1553}
1554
1555/* socket shutdown does a del_timer_sync against this as it tears down.
1556 * we can't start this timer until we've got to the point in sc buildup
1557 * where shutdown is going to be involved */
1558static void o2net_idle_timer(unsigned long data)
1559{
1560	struct o2net_sock_container *sc = (struct o2net_sock_container *)data;
1561	struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
 
1562#ifdef CONFIG_DEBUG_FS
1563	unsigned long msecs = ktime_to_ms(ktime_get()) -
1564		ktime_to_ms(sc->sc_tv_timer);
1565#else
1566	unsigned long msecs = o2net_idle_timeout();
1567#endif
1568
1569	printk(KERN_NOTICE "o2net: Connection to " SC_NODEF_FMT " has been "
1570	       "idle for %lu.%lu secs, shutting it down.\n", SC_NODEF_ARGS(sc),
1571	       msecs / 1000, msecs % 1000);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1572
1573	/*
1574	 * Initialize the nn_timeout so that the next connection attempt
1575	 * will continue in o2net_start_connect.
1576	 */
1577	atomic_set(&nn->nn_timeout, 1);
1578
1579	o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
1580}
1581
1582static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc)
1583{
1584	o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
1585	o2net_sc_queue_delayed_work(sc, &sc->sc_keepalive_work,
1586		      msecs_to_jiffies(o2net_keepalive_delay()));
1587	o2net_set_sock_timer(sc);
1588	mod_timer(&sc->sc_idle_timeout,
1589	       jiffies + msecs_to_jiffies(o2net_idle_timeout()));
1590}
1591
1592static void o2net_sc_postpone_idle(struct o2net_sock_container *sc)
1593{
1594	/* Only push out an existing timer */
1595	if (timer_pending(&sc->sc_idle_timeout))
1596		o2net_sc_reset_idle_timer(sc);
1597}
1598
1599/* this work func is kicked whenever a path sets the nn state which doesn't
1600 * have valid set.  This includes seeing hb come up, losing a connection,
1601 * having a connect attempt fail, etc. This centralizes the logic which decides
1602 * if a connect attempt should be made or if we should give up and all future
1603 * transmit attempts should fail */
1604static void o2net_start_connect(struct work_struct *work)
1605{
1606	struct o2net_node *nn =
1607		container_of(work, struct o2net_node, nn_connect_work.work);
1608	struct o2net_sock_container *sc = NULL;
1609	struct o2nm_node *node = NULL, *mynode = NULL;
1610	struct socket *sock = NULL;
1611	struct sockaddr_in myaddr = {0, }, remoteaddr = {0, };
1612	int ret = 0, stop;
1613	unsigned int timeout;
1614
1615	/* if we're greater we initiate tx, otherwise we accept */
1616	if (o2nm_this_node() <= o2net_num_from_nn(nn))
1617		goto out;
1618
1619	/* watch for racing with tearing a node down */
1620	node = o2nm_get_node_by_num(o2net_num_from_nn(nn));
1621	if (node == NULL) {
1622		ret = 0;
1623		goto out;
1624	}
1625
1626	mynode = o2nm_get_node_by_num(o2nm_this_node());
1627	if (mynode == NULL) {
1628		ret = 0;
1629		goto out;
1630	}
1631
1632	spin_lock(&nn->nn_lock);
1633	/*
1634	 * see if we already have one pending or have given up.
1635	 * For nn_timeout, it is set when we close the connection
1636	 * because of the idle time out. So it means that we have
1637	 * at least connected to that node successfully once,
1638	 * now try to connect to it again.
1639	 */
1640	timeout = atomic_read(&nn->nn_timeout);
1641	stop = (nn->nn_sc ||
1642		(nn->nn_persistent_error &&
1643		(nn->nn_persistent_error != -ENOTCONN || timeout == 0)));
1644	spin_unlock(&nn->nn_lock);
1645	if (stop)
1646		goto out;
1647
1648	nn->nn_last_connect_attempt = jiffies;
1649
1650	sc = sc_alloc(node);
1651	if (sc == NULL) {
1652		mlog(0, "couldn't allocate sc\n");
1653		ret = -ENOMEM;
1654		goto out;
1655	}
1656
1657	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1658	if (ret < 0) {
1659		mlog(0, "can't create socket: %d\n", ret);
1660		goto out;
1661	}
1662	sc->sc_sock = sock; /* freed by sc_kref_release */
1663
1664	sock->sk->sk_allocation = GFP_ATOMIC;
1665
1666	myaddr.sin_family = AF_INET;
1667	myaddr.sin_addr.s_addr = mynode->nd_ipv4_address;
1668	myaddr.sin_port = htons(0); /* any port */
1669
1670	ret = sock->ops->bind(sock, (struct sockaddr *)&myaddr,
1671			      sizeof(myaddr));
1672	if (ret) {
1673		mlog(ML_ERROR, "bind failed with %d at address %pI4\n",
1674		     ret, &mynode->nd_ipv4_address);
1675		goto out;
1676	}
1677
1678	ret = o2net_set_nodelay(sc->sc_sock);
1679	if (ret) {
1680		mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
1681		goto out;
1682	}
1683
1684	o2net_register_callbacks(sc->sc_sock->sk, sc);
1685
1686	spin_lock(&nn->nn_lock);
1687	/* handshake completion will set nn->nn_sc_valid */
1688	o2net_set_nn_state(nn, sc, 0, 0);
1689	spin_unlock(&nn->nn_lock);
1690
1691	remoteaddr.sin_family = AF_INET;
1692	remoteaddr.sin_addr.s_addr = node->nd_ipv4_address;
1693	remoteaddr.sin_port = node->nd_ipv4_port;
1694
1695	ret = sc->sc_sock->ops->connect(sc->sc_sock,
1696					(struct sockaddr *)&remoteaddr,
1697					sizeof(remoteaddr),
1698					O_NONBLOCK);
1699	if (ret == -EINPROGRESS)
1700		ret = 0;
1701
1702out:
1703	if (ret) {
1704		printk(KERN_NOTICE "o2net: Connect attempt to " SC_NODEF_FMT
1705		       " failed with errno %d\n", SC_NODEF_ARGS(sc), ret);
1706		/* 0 err so that another will be queued and attempted
1707		 * from set_nn_state */
1708		if (sc)
1709			o2net_ensure_shutdown(nn, sc, 0);
1710	}
1711	if (sc)
1712		sc_put(sc);
1713	if (node)
1714		o2nm_node_put(node);
1715	if (mynode)
1716		o2nm_node_put(mynode);
1717
1718	return;
1719}
1720
1721static void o2net_connect_expired(struct work_struct *work)
1722{
1723	struct o2net_node *nn =
1724		container_of(work, struct o2net_node, nn_connect_expired.work);
1725
1726	spin_lock(&nn->nn_lock);
1727	if (!nn->nn_sc_valid) {
1728		printk(KERN_NOTICE "o2net: No connection established with "
1729		       "node %u after %u.%u seconds, giving up.\n",
1730		     o2net_num_from_nn(nn),
1731		     o2net_idle_timeout() / 1000,
1732		     o2net_idle_timeout() % 1000);
1733
1734		o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
1735	}
1736	spin_unlock(&nn->nn_lock);
1737}
1738
1739static void o2net_still_up(struct work_struct *work)
1740{
1741	struct o2net_node *nn =
1742		container_of(work, struct o2net_node, nn_still_up.work);
1743
1744	o2quo_hb_still_up(o2net_num_from_nn(nn));
1745}
1746
1747/* ------------------------------------------------------------ */
1748
1749void o2net_disconnect_node(struct o2nm_node *node)
1750{
1751	struct o2net_node *nn = o2net_nn_from_num(node->nd_num);
1752
1753	/* don't reconnect until it's heartbeating again */
1754	spin_lock(&nn->nn_lock);
1755	atomic_set(&nn->nn_timeout, 0);
1756	o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
1757	spin_unlock(&nn->nn_lock);
1758
1759	if (o2net_wq) {
1760		cancel_delayed_work(&nn->nn_connect_expired);
1761		cancel_delayed_work(&nn->nn_connect_work);
1762		cancel_delayed_work(&nn->nn_still_up);
1763		flush_workqueue(o2net_wq);
1764	}
1765}
1766
1767static void o2net_hb_node_down_cb(struct o2nm_node *node, int node_num,
1768				  void *data)
1769{
1770	o2quo_hb_down(node_num);
1771
1772	if (!node)
1773		return;
1774
1775	if (node_num != o2nm_this_node())
1776		o2net_disconnect_node(node);
1777
1778	BUG_ON(atomic_read(&o2net_connected_peers) < 0);
1779}
1780
1781static void o2net_hb_node_up_cb(struct o2nm_node *node, int node_num,
1782				void *data)
1783{
1784	struct o2net_node *nn = o2net_nn_from_num(node_num);
1785
1786	o2quo_hb_up(node_num);
1787
1788	BUG_ON(!node);
1789
1790	/* ensure an immediate connect attempt */
1791	nn->nn_last_connect_attempt = jiffies -
1792		(msecs_to_jiffies(o2net_reconnect_delay()) + 1);
1793
1794	if (node_num != o2nm_this_node()) {
1795		/* believe it or not, accept and node hearbeating testing
1796		 * can succeed for this node before we got here.. so
1797		 * only use set_nn_state to clear the persistent error
1798		 * if that hasn't already happened */
1799		spin_lock(&nn->nn_lock);
1800		atomic_set(&nn->nn_timeout, 0);
1801		if (nn->nn_persistent_error)
1802			o2net_set_nn_state(nn, NULL, 0, 0);
1803		spin_unlock(&nn->nn_lock);
1804	}
1805}
1806
1807void o2net_unregister_hb_callbacks(void)
1808{
1809	o2hb_unregister_callback(NULL, &o2net_hb_up);
1810	o2hb_unregister_callback(NULL, &o2net_hb_down);
1811}
1812
1813int o2net_register_hb_callbacks(void)
1814{
1815	int ret;
1816
1817	o2hb_setup_callback(&o2net_hb_down, O2HB_NODE_DOWN_CB,
1818			    o2net_hb_node_down_cb, NULL, O2NET_HB_PRI);
1819	o2hb_setup_callback(&o2net_hb_up, O2HB_NODE_UP_CB,
1820			    o2net_hb_node_up_cb, NULL, O2NET_HB_PRI);
1821
1822	ret = o2hb_register_callback(NULL, &o2net_hb_up);
1823	if (ret == 0)
1824		ret = o2hb_register_callback(NULL, &o2net_hb_down);
1825
1826	if (ret)
1827		o2net_unregister_hb_callbacks();
1828
1829	return ret;
1830}
1831
1832/* ------------------------------------------------------------ */
1833
1834static int o2net_accept_one(struct socket *sock)
1835{
1836	int ret, slen;
1837	struct sockaddr_in sin;
1838	struct socket *new_sock = NULL;
1839	struct o2nm_node *node = NULL;
1840	struct o2nm_node *local_node = NULL;
1841	struct o2net_sock_container *sc = NULL;
1842	struct o2net_node *nn;
1843
1844	BUG_ON(sock == NULL);
1845	ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
1846			       sock->sk->sk_protocol, &new_sock);
1847	if (ret)
1848		goto out;
1849
1850	new_sock->type = sock->type;
1851	new_sock->ops = sock->ops;
1852	ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
1853	if (ret < 0)
1854		goto out;
1855
1856	new_sock->sk->sk_allocation = GFP_ATOMIC;
1857
1858	ret = o2net_set_nodelay(new_sock);
1859	if (ret) {
1860		mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
1861		goto out;
1862	}
1863
1864	slen = sizeof(sin);
1865	ret = new_sock->ops->getname(new_sock, (struct sockaddr *) &sin,
1866				       &slen, 1);
1867	if (ret < 0)
1868		goto out;
1869
1870	node = o2nm_get_node_by_ip(sin.sin_addr.s_addr);
1871	if (node == NULL) {
1872		printk(KERN_NOTICE "o2net: Attempt to connect from unknown "
1873		       "node at %pI4:%d\n", &sin.sin_addr.s_addr,
1874		       ntohs(sin.sin_port));
1875		ret = -EINVAL;
1876		goto out;
1877	}
1878
1879	if (o2nm_this_node() >= node->nd_num) {
1880		local_node = o2nm_get_node_by_num(o2nm_this_node());
1881		printk(KERN_NOTICE "o2net: Unexpected connect attempt seen "
1882		       "at node '%s' (%u, %pI4:%d) from node '%s' (%u, "
1883		       "%pI4:%d)\n", local_node->nd_name, local_node->nd_num,
1884		       &(local_node->nd_ipv4_address),
1885		       ntohs(local_node->nd_ipv4_port), node->nd_name,
1886		       node->nd_num, &sin.sin_addr.s_addr, ntohs(sin.sin_port));
 
1887		ret = -EINVAL;
1888		goto out;
1889	}
1890
1891	/* this happens all the time when the other node sees our heartbeat
1892	 * and tries to connect before we see their heartbeat */
1893	if (!o2hb_check_node_heartbeating_from_callback(node->nd_num)) {
1894		mlog(ML_CONN, "attempt to connect from node '%s' at "
1895		     "%pI4:%d but it isn't heartbeating\n",
1896		     node->nd_name, &sin.sin_addr.s_addr,
1897		     ntohs(sin.sin_port));
1898		ret = -EINVAL;
1899		goto out;
1900	}
1901
1902	nn = o2net_nn_from_num(node->nd_num);
1903
1904	spin_lock(&nn->nn_lock);
1905	if (nn->nn_sc)
1906		ret = -EBUSY;
1907	else
1908		ret = 0;
1909	spin_unlock(&nn->nn_lock);
1910	if (ret) {
1911		printk(KERN_NOTICE "o2net: Attempt to connect from node '%s' "
1912		       "at %pI4:%d but it already has an open connection\n",
1913		       node->nd_name, &sin.sin_addr.s_addr,
1914		       ntohs(sin.sin_port));
1915		goto out;
1916	}
1917
1918	sc = sc_alloc(node);
1919	if (sc == NULL) {
1920		ret = -ENOMEM;
1921		goto out;
1922	}
1923
1924	sc->sc_sock = new_sock;
1925	new_sock = NULL;
1926
1927	spin_lock(&nn->nn_lock);
1928	atomic_set(&nn->nn_timeout, 0);
1929	o2net_set_nn_state(nn, sc, 0, 0);
1930	spin_unlock(&nn->nn_lock);
1931
1932	o2net_register_callbacks(sc->sc_sock->sk, sc);
1933	o2net_sc_queue_work(sc, &sc->sc_rx_work);
1934
1935	o2net_initialize_handshake();
1936	o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1937
1938out:
1939	if (new_sock)
1940		sock_release(new_sock);
1941	if (node)
1942		o2nm_node_put(node);
1943	if (local_node)
1944		o2nm_node_put(local_node);
1945	if (sc)
1946		sc_put(sc);
1947	return ret;
1948}
1949
1950static void o2net_accept_many(struct work_struct *work)
1951{
1952	struct socket *sock = o2net_listen_sock;
1953	while (o2net_accept_one(sock) == 0)
1954		cond_resched();
1955}
1956
1957static void o2net_listen_data_ready(struct sock *sk, int bytes)
1958{
1959	void (*ready)(struct sock *sk, int bytes);
1960
1961	read_lock(&sk->sk_callback_lock);
1962	ready = sk->sk_user_data;
1963	if (ready == NULL) { /* check for teardown race */
1964		ready = sk->sk_data_ready;
1965		goto out;
1966	}
1967
1968	/* ->sk_data_ready is also called for a newly established child socket
1969	 * before it has been accepted and the acceptor has set up their
1970	 * data_ready.. we only want to queue listen work for our listening
1971	 * socket */
1972	if (sk->sk_state == TCP_LISTEN) {
1973		mlog(ML_TCP, "bytes: %d\n", bytes);
1974		queue_work(o2net_wq, &o2net_listen_work);
1975	}
1976
1977out:
1978	read_unlock(&sk->sk_callback_lock);
1979	ready(sk, bytes);
1980}
1981
1982static int o2net_open_listening_sock(__be32 addr, __be16 port)
1983{
1984	struct socket *sock = NULL;
1985	int ret;
1986	struct sockaddr_in sin = {
1987		.sin_family = PF_INET,
1988		.sin_addr = { .s_addr = addr },
1989		.sin_port = port,
1990	};
1991
1992	ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1993	if (ret < 0) {
1994		printk(KERN_ERR "o2net: Error %d while creating socket\n", ret);
1995		goto out;
1996	}
1997
1998	sock->sk->sk_allocation = GFP_ATOMIC;
1999
2000	write_lock_bh(&sock->sk->sk_callback_lock);
2001	sock->sk->sk_user_data = sock->sk->sk_data_ready;
2002	sock->sk->sk_data_ready = o2net_listen_data_ready;
2003	write_unlock_bh(&sock->sk->sk_callback_lock);
2004
2005	o2net_listen_sock = sock;
2006	INIT_WORK(&o2net_listen_work, o2net_accept_many);
2007
2008	sock->sk->sk_reuse = SK_CAN_REUSE;
2009	ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
2010	if (ret < 0) {
2011		printk(KERN_ERR "o2net: Error %d while binding socket at "
2012		       "%pI4:%u\n", ret, &addr, ntohs(port)); 
2013		goto out;
2014	}
2015
2016	ret = sock->ops->listen(sock, 64);
2017	if (ret < 0)
2018		printk(KERN_ERR "o2net: Error %d while listening on %pI4:%u\n",
2019		       ret, &addr, ntohs(port));
 
2020
2021out:
2022	if (ret) {
2023		o2net_listen_sock = NULL;
2024		if (sock)
2025			sock_release(sock);
2026	}
2027	return ret;
2028}
2029
2030/*
2031 * called from node manager when we should bring up our network listening
2032 * socket.  node manager handles all the serialization to only call this
2033 * once and to match it with o2net_stop_listening().  note,
2034 * o2nm_this_node() doesn't work yet as we're being called while it
2035 * is being set up.
2036 */
2037int o2net_start_listening(struct o2nm_node *node)
2038{
2039	int ret = 0;
2040
2041	BUG_ON(o2net_wq != NULL);
2042	BUG_ON(o2net_listen_sock != NULL);
2043
2044	mlog(ML_KTHREAD, "starting o2net thread...\n");
2045	o2net_wq = create_singlethread_workqueue("o2net");
2046	if (o2net_wq == NULL) {
2047		mlog(ML_ERROR, "unable to launch o2net thread\n");
2048		return -ENOMEM; /* ? */
2049	}
2050
2051	ret = o2net_open_listening_sock(node->nd_ipv4_address,
2052					node->nd_ipv4_port);
2053	if (ret) {
2054		destroy_workqueue(o2net_wq);
2055		o2net_wq = NULL;
2056	} else
2057		o2quo_conn_up(node->nd_num);
2058
2059	return ret;
2060}
2061
2062/* again, o2nm_this_node() doesn't work here as we're involved in
2063 * tearing it down */
2064void o2net_stop_listening(struct o2nm_node *node)
2065{
2066	struct socket *sock = o2net_listen_sock;
2067	size_t i;
2068
2069	BUG_ON(o2net_wq == NULL);
2070	BUG_ON(o2net_listen_sock == NULL);
2071
2072	/* stop the listening socket from generating work */
2073	write_lock_bh(&sock->sk->sk_callback_lock);
2074	sock->sk->sk_data_ready = sock->sk->sk_user_data;
2075	sock->sk->sk_user_data = NULL;
2076	write_unlock_bh(&sock->sk->sk_callback_lock);
2077
2078	for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
2079		struct o2nm_node *node = o2nm_get_node_by_num(i);
2080		if (node) {
2081			o2net_disconnect_node(node);
2082			o2nm_node_put(node);
2083		}
2084	}
2085
2086	/* finish all work and tear down the work queue */
2087	mlog(ML_KTHREAD, "waiting for o2net thread to exit....\n");
2088	destroy_workqueue(o2net_wq);
2089	o2net_wq = NULL;
2090
2091	sock_release(o2net_listen_sock);
2092	o2net_listen_sock = NULL;
2093
2094	o2quo_conn_err(node->nd_num);
2095}
2096
2097/* ------------------------------------------------------------ */
2098
2099int o2net_init(void)
2100{
2101	unsigned long i;
2102
2103	o2quo_init();
2104
2105	if (o2net_debugfs_init())
2106		return -ENOMEM;
2107
2108	o2net_hand = kzalloc(sizeof(struct o2net_handshake), GFP_KERNEL);
2109	o2net_keep_req = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
2110	o2net_keep_resp = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
2111	if (!o2net_hand || !o2net_keep_req || !o2net_keep_resp) {
2112		kfree(o2net_hand);
2113		kfree(o2net_keep_req);
2114		kfree(o2net_keep_resp);
2115		return -ENOMEM;
2116	}
2117
2118	o2net_hand->protocol_version = cpu_to_be64(O2NET_PROTOCOL_VERSION);
2119	o2net_hand->connector_id = cpu_to_be64(1);
2120
2121	o2net_keep_req->magic = cpu_to_be16(O2NET_MSG_KEEP_REQ_MAGIC);
2122	o2net_keep_resp->magic = cpu_to_be16(O2NET_MSG_KEEP_RESP_MAGIC);
2123
2124	for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
2125		struct o2net_node *nn = o2net_nn_from_num(i);
2126
2127		atomic_set(&nn->nn_timeout, 0);
2128		spin_lock_init(&nn->nn_lock);
2129		INIT_DELAYED_WORK(&nn->nn_connect_work, o2net_start_connect);
2130		INIT_DELAYED_WORK(&nn->nn_connect_expired,
2131				  o2net_connect_expired);
2132		INIT_DELAYED_WORK(&nn->nn_still_up, o2net_still_up);
2133		/* until we see hb from a node we'll return einval */
2134		nn->nn_persistent_error = -ENOTCONN;
2135		init_waitqueue_head(&nn->nn_sc_wq);
2136		idr_init(&nn->nn_status_idr);
2137		INIT_LIST_HEAD(&nn->nn_status_list);
2138	}
2139
2140	return 0;
2141}
2142
2143void o2net_exit(void)
2144{
2145	o2quo_exit();
2146	kfree(o2net_hand);
2147	kfree(o2net_keep_req);
2148	kfree(o2net_keep_resp);
2149	o2net_debugfs_exit();
2150}