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[karo-tx-linux.git] / net / tipc / node.c
1 /*
2  * net/tipc/node.c: TIPC node management routines
3  *
4  * Copyright (c) 2000-2006, 2012-2014, Ericsson AB
5  * Copyright (c) 2005-2006, 2010-2014, Wind River Systems
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the names of the copyright holders nor the names of its
17  *    contributors may be used to endorse or promote products derived from
18  *    this software without specific prior written permission.
19  *
20  * Alternatively, this software may be distributed under the terms of the
21  * GNU General Public License ("GPL") version 2 as published by the Free
22  * Software Foundation.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34  * POSSIBILITY OF SUCH DAMAGE.
35  */
36
37 #include "core.h"
38 #include "config.h"
39 #include "node.h"
40 #include "name_distr.h"
41 #include "socket.h"
42
43 #define NODE_HTABLE_SIZE 512
44
45 static void node_lost_contact(struct tipc_node *n_ptr);
46 static void node_established_contact(struct tipc_node *n_ptr);
47
48 static struct hlist_head node_htable[NODE_HTABLE_SIZE];
49 LIST_HEAD(tipc_node_list);
50 static u32 tipc_num_nodes;
51 static u32 tipc_num_links;
52 static DEFINE_SPINLOCK(node_list_lock);
53
54 struct tipc_sock_conn {
55         u32 port;
56         u32 peer_port;
57         u32 peer_node;
58         struct list_head list;
59 };
60
61 /*
62  * A trivial power-of-two bitmask technique is used for speed, since this
63  * operation is done for every incoming TIPC packet. The number of hash table
64  * entries has been chosen so that no hash chain exceeds 8 nodes and will
65  * usually be much smaller (typically only a single node).
66  */
67 static unsigned int tipc_hashfn(u32 addr)
68 {
69         return addr & (NODE_HTABLE_SIZE - 1);
70 }
71
72 /*
73  * tipc_node_find - locate specified node object, if it exists
74  */
75 struct tipc_node *tipc_node_find(u32 addr)
76 {
77         struct tipc_node *node;
78
79         if (unlikely(!in_own_cluster_exact(addr)))
80                 return NULL;
81
82         rcu_read_lock();
83         hlist_for_each_entry_rcu(node, &node_htable[tipc_hashfn(addr)], hash) {
84                 if (node->addr == addr) {
85                         rcu_read_unlock();
86                         return node;
87                 }
88         }
89         rcu_read_unlock();
90         return NULL;
91 }
92
93 struct tipc_node *tipc_node_create(u32 addr)
94 {
95         struct tipc_node *n_ptr, *temp_node;
96
97         spin_lock_bh(&node_list_lock);
98
99         n_ptr = kzalloc(sizeof(*n_ptr), GFP_ATOMIC);
100         if (!n_ptr) {
101                 spin_unlock_bh(&node_list_lock);
102                 pr_warn("Node creation failed, no memory\n");
103                 return NULL;
104         }
105
106         n_ptr->addr = addr;
107         spin_lock_init(&n_ptr->lock);
108         INIT_HLIST_NODE(&n_ptr->hash);
109         INIT_LIST_HEAD(&n_ptr->list);
110         INIT_LIST_HEAD(&n_ptr->nsub);
111         INIT_LIST_HEAD(&n_ptr->conn_sks);
112         __skb_queue_head_init(&n_ptr->waiting_sks);
113
114         hlist_add_head_rcu(&n_ptr->hash, &node_htable[tipc_hashfn(addr)]);
115
116         list_for_each_entry_rcu(temp_node, &tipc_node_list, list) {
117                 if (n_ptr->addr < temp_node->addr)
118                         break;
119         }
120         list_add_tail_rcu(&n_ptr->list, &temp_node->list);
121         n_ptr->action_flags = TIPC_WAIT_PEER_LINKS_DOWN;
122         n_ptr->signature = INVALID_NODE_SIG;
123
124         tipc_num_nodes++;
125
126         spin_unlock_bh(&node_list_lock);
127         return n_ptr;
128 }
129
130 static void tipc_node_delete(struct tipc_node *n_ptr)
131 {
132         list_del_rcu(&n_ptr->list);
133         hlist_del_rcu(&n_ptr->hash);
134         kfree_rcu(n_ptr, rcu);
135
136         tipc_num_nodes--;
137 }
138
139 void tipc_node_stop(void)
140 {
141         struct tipc_node *node, *t_node;
142
143         spin_lock_bh(&node_list_lock);
144         list_for_each_entry_safe(node, t_node, &tipc_node_list, list)
145                 tipc_node_delete(node);
146         spin_unlock_bh(&node_list_lock);
147 }
148
149 int tipc_node_add_conn(u32 dnode, u32 port, u32 peer_port)
150 {
151         struct tipc_node *node;
152         struct tipc_sock_conn *conn;
153
154         if (in_own_node(dnode))
155                 return 0;
156
157         node = tipc_node_find(dnode);
158         if (!node) {
159                 pr_warn("Connecting sock to node 0x%x failed\n", dnode);
160                 return -EHOSTUNREACH;
161         }
162         conn = kmalloc(sizeof(*conn), GFP_ATOMIC);
163         if (!conn)
164                 return -EHOSTUNREACH;
165         conn->peer_node = dnode;
166         conn->port = port;
167         conn->peer_port = peer_port;
168
169         tipc_node_lock(node);
170         list_add_tail(&conn->list, &node->conn_sks);
171         tipc_node_unlock(node);
172         return 0;
173 }
174
175 void tipc_node_remove_conn(u32 dnode, u32 port)
176 {
177         struct tipc_node *node;
178         struct tipc_sock_conn *conn, *safe;
179
180         if (in_own_node(dnode))
181                 return;
182
183         node = tipc_node_find(dnode);
184         if (!node)
185                 return;
186
187         tipc_node_lock(node);
188         list_for_each_entry_safe(conn, safe, &node->conn_sks, list) {
189                 if (port != conn->port)
190                         continue;
191                 list_del(&conn->list);
192                 kfree(conn);
193         }
194         tipc_node_unlock(node);
195 }
196
197 void tipc_node_abort_sock_conns(struct list_head *conns)
198 {
199         struct tipc_sock_conn *conn, *safe;
200         struct sk_buff *buf;
201
202         list_for_each_entry_safe(conn, safe, conns, list) {
203                 buf = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG,
204                                       SHORT_H_SIZE, 0, tipc_own_addr,
205                                       conn->peer_node, conn->port,
206                                       conn->peer_port, TIPC_ERR_NO_NODE);
207                 if (likely(buf))
208                         tipc_sk_rcv(buf);
209                 list_del(&conn->list);
210                 kfree(conn);
211         }
212 }
213
214 /**
215  * tipc_node_link_up - handle addition of link
216  *
217  * Link becomes active (alone or shared) or standby, depending on its priority.
218  */
219 void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
220 {
221         struct tipc_link **active = &n_ptr->active_links[0];
222
223         n_ptr->working_links++;
224         n_ptr->action_flags |= TIPC_NOTIFY_LINK_UP;
225         n_ptr->link_id = l_ptr->peer_bearer_id << 16 | l_ptr->bearer_id;
226
227         pr_info("Established link <%s> on network plane %c\n",
228                 l_ptr->name, l_ptr->net_plane);
229
230         if (!active[0]) {
231                 active[0] = active[1] = l_ptr;
232                 node_established_contact(n_ptr);
233                 goto exit;
234         }
235         if (l_ptr->priority < active[0]->priority) {
236                 pr_info("New link <%s> becomes standby\n", l_ptr->name);
237                 goto exit;
238         }
239         tipc_link_dup_queue_xmit(active[0], l_ptr);
240         if (l_ptr->priority == active[0]->priority) {
241                 active[0] = l_ptr;
242                 goto exit;
243         }
244         pr_info("Old link <%s> becomes standby\n", active[0]->name);
245         if (active[1] != active[0])
246                 pr_info("Old link <%s> becomes standby\n", active[1]->name);
247         active[0] = active[1] = l_ptr;
248 exit:
249         /* Leave room for changeover header when returning 'mtu' to users: */
250         n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE;
251         n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE;
252 }
253
254 /**
255  * node_select_active_links - select active link
256  */
257 static void node_select_active_links(struct tipc_node *n_ptr)
258 {
259         struct tipc_link **active = &n_ptr->active_links[0];
260         u32 i;
261         u32 highest_prio = 0;
262
263         active[0] = active[1] = NULL;
264
265         for (i = 0; i < MAX_BEARERS; i++) {
266                 struct tipc_link *l_ptr = n_ptr->links[i];
267
268                 if (!l_ptr || !tipc_link_is_up(l_ptr) ||
269                     (l_ptr->priority < highest_prio))
270                         continue;
271
272                 if (l_ptr->priority > highest_prio) {
273                         highest_prio = l_ptr->priority;
274                         active[0] = active[1] = l_ptr;
275                 } else {
276                         active[1] = l_ptr;
277                 }
278         }
279 }
280
281 /**
282  * tipc_node_link_down - handle loss of link
283  */
284 void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
285 {
286         struct tipc_link **active;
287
288         n_ptr->working_links--;
289         n_ptr->action_flags |= TIPC_NOTIFY_LINK_DOWN;
290         n_ptr->link_id = l_ptr->peer_bearer_id << 16 | l_ptr->bearer_id;
291
292         if (!tipc_link_is_active(l_ptr)) {
293                 pr_info("Lost standby link <%s> on network plane %c\n",
294                         l_ptr->name, l_ptr->net_plane);
295                 return;
296         }
297         pr_info("Lost link <%s> on network plane %c\n",
298                 l_ptr->name, l_ptr->net_plane);
299
300         active = &n_ptr->active_links[0];
301         if (active[0] == l_ptr)
302                 active[0] = active[1];
303         if (active[1] == l_ptr)
304                 active[1] = active[0];
305         if (active[0] == l_ptr)
306                 node_select_active_links(n_ptr);
307         if (tipc_node_is_up(n_ptr))
308                 tipc_link_failover_send_queue(l_ptr);
309         else
310                 node_lost_contact(n_ptr);
311
312         /* Leave room for changeover header when returning 'mtu' to users: */
313         if (active[0]) {
314                 n_ptr->act_mtus[0] = active[0]->max_pkt - INT_H_SIZE;
315                 n_ptr->act_mtus[1] = active[1]->max_pkt - INT_H_SIZE;
316                 return;
317         }
318
319         /* Loopback link went down? No fragmentation needed from now on. */
320         if (n_ptr->addr == tipc_own_addr) {
321                 n_ptr->act_mtus[0] = MAX_MSG_SIZE;
322                 n_ptr->act_mtus[1] = MAX_MSG_SIZE;
323         }
324 }
325
326 int tipc_node_active_links(struct tipc_node *n_ptr)
327 {
328         return n_ptr->active_links[0] != NULL;
329 }
330
331 int tipc_node_is_up(struct tipc_node *n_ptr)
332 {
333         return tipc_node_active_links(n_ptr);
334 }
335
336 void tipc_node_attach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
337 {
338         n_ptr->links[l_ptr->bearer_id] = l_ptr;
339         spin_lock_bh(&node_list_lock);
340         tipc_num_links++;
341         spin_unlock_bh(&node_list_lock);
342         n_ptr->link_cnt++;
343 }
344
345 void tipc_node_detach_link(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
346 {
347         int i;
348
349         for (i = 0; i < MAX_BEARERS; i++) {
350                 if (l_ptr != n_ptr->links[i])
351                         continue;
352                 n_ptr->links[i] = NULL;
353                 spin_lock_bh(&node_list_lock);
354                 tipc_num_links--;
355                 spin_unlock_bh(&node_list_lock);
356                 n_ptr->link_cnt--;
357         }
358 }
359
360 static void node_established_contact(struct tipc_node *n_ptr)
361 {
362         n_ptr->action_flags |= TIPC_NOTIFY_NODE_UP;
363         n_ptr->bclink.oos_state = 0;
364         n_ptr->bclink.acked = tipc_bclink_get_last_sent();
365         tipc_bclink_add_node(n_ptr->addr);
366 }
367
368 static void node_lost_contact(struct tipc_node *n_ptr)
369 {
370         char addr_string[16];
371         u32 i;
372
373         pr_info("Lost contact with %s\n",
374                 tipc_addr_string_fill(addr_string, n_ptr->addr));
375
376         /* Flush broadcast link info associated with lost node */
377         if (n_ptr->bclink.recv_permitted) {
378                 kfree_skb_list(n_ptr->bclink.deferred_head);
379                 n_ptr->bclink.deferred_size = 0;
380
381                 if (n_ptr->bclink.reasm_buf) {
382                         kfree_skb(n_ptr->bclink.reasm_buf);
383                         n_ptr->bclink.reasm_buf = NULL;
384                 }
385
386                 tipc_bclink_remove_node(n_ptr->addr);
387                 tipc_bclink_acknowledge(n_ptr, INVALID_LINK_SEQ);
388
389                 n_ptr->bclink.recv_permitted = false;
390         }
391
392         /* Abort link changeover */
393         for (i = 0; i < MAX_BEARERS; i++) {
394                 struct tipc_link *l_ptr = n_ptr->links[i];
395                 if (!l_ptr)
396                         continue;
397                 l_ptr->reset_checkpoint = l_ptr->next_in_no;
398                 l_ptr->exp_msg_count = 0;
399                 tipc_link_reset_fragments(l_ptr);
400         }
401
402         n_ptr->action_flags &= ~TIPC_WAIT_OWN_LINKS_DOWN;
403
404         /* Notify subscribers and prevent re-contact with node until
405          * cleanup is done.
406          */
407         n_ptr->action_flags |= TIPC_WAIT_PEER_LINKS_DOWN |
408                                TIPC_NOTIFY_NODE_DOWN;
409 }
410
411 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space)
412 {
413         u32 domain;
414         struct sk_buff *buf;
415         struct tipc_node *n_ptr;
416         struct tipc_node_info node_info;
417         u32 payload_size;
418
419         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
420                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
421
422         domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
423         if (!tipc_addr_domain_valid(domain))
424                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
425                                                    " (network address)");
426
427         spin_lock_bh(&node_list_lock);
428         if (!tipc_num_nodes) {
429                 spin_unlock_bh(&node_list_lock);
430                 return tipc_cfg_reply_none();
431         }
432
433         /* For now, get space for all other nodes */
434         payload_size = TLV_SPACE(sizeof(node_info)) * tipc_num_nodes;
435         if (payload_size > 32768u) {
436                 spin_unlock_bh(&node_list_lock);
437                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
438                                                    " (too many nodes)");
439         }
440         spin_unlock_bh(&node_list_lock);
441
442         buf = tipc_cfg_reply_alloc(payload_size);
443         if (!buf)
444                 return NULL;
445
446         /* Add TLVs for all nodes in scope */
447         rcu_read_lock();
448         list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
449                 if (!tipc_in_scope(domain, n_ptr->addr))
450                         continue;
451                 node_info.addr = htonl(n_ptr->addr);
452                 node_info.up = htonl(tipc_node_is_up(n_ptr));
453                 tipc_cfg_append_tlv(buf, TIPC_TLV_NODE_INFO,
454                                     &node_info, sizeof(node_info));
455         }
456         rcu_read_unlock();
457         return buf;
458 }
459
460 struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
461 {
462         u32 domain;
463         struct sk_buff *buf;
464         struct tipc_node *n_ptr;
465         struct tipc_link_info link_info;
466         u32 payload_size;
467
468         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
469                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
470
471         domain = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
472         if (!tipc_addr_domain_valid(domain))
473                 return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
474                                                    " (network address)");
475
476         if (!tipc_own_addr)
477                 return tipc_cfg_reply_none();
478
479         spin_lock_bh(&node_list_lock);
480         /* Get space for all unicast links + broadcast link */
481         payload_size = TLV_SPACE((sizeof(link_info)) * (tipc_num_links + 1));
482         if (payload_size > 32768u) {
483                 spin_unlock_bh(&node_list_lock);
484                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
485                                                    " (too many links)");
486         }
487         spin_unlock_bh(&node_list_lock);
488
489         buf = tipc_cfg_reply_alloc(payload_size);
490         if (!buf)
491                 return NULL;
492
493         /* Add TLV for broadcast link */
494         link_info.dest = htonl(tipc_cluster_mask(tipc_own_addr));
495         link_info.up = htonl(1);
496         strlcpy(link_info.str, tipc_bclink_name, TIPC_MAX_LINK_NAME);
497         tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO, &link_info, sizeof(link_info));
498
499         /* Add TLVs for any other links in scope */
500         rcu_read_lock();
501         list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
502                 u32 i;
503
504                 if (!tipc_in_scope(domain, n_ptr->addr))
505                         continue;
506                 tipc_node_lock(n_ptr);
507                 for (i = 0; i < MAX_BEARERS; i++) {
508                         if (!n_ptr->links[i])
509                                 continue;
510                         link_info.dest = htonl(n_ptr->addr);
511                         link_info.up = htonl(tipc_link_is_up(n_ptr->links[i]));
512                         strcpy(link_info.str, n_ptr->links[i]->name);
513                         tipc_cfg_append_tlv(buf, TIPC_TLV_LINK_INFO,
514                                             &link_info, sizeof(link_info));
515                 }
516                 tipc_node_unlock(n_ptr);
517         }
518         rcu_read_unlock();
519         return buf;
520 }
521
522 /**
523  * tipc_node_get_linkname - get the name of a link
524  *
525  * @bearer_id: id of the bearer
526  * @node: peer node address
527  * @linkname: link name output buffer
528  *
529  * Returns 0 on success
530  */
531 int tipc_node_get_linkname(u32 bearer_id, u32 addr, char *linkname, size_t len)
532 {
533         struct tipc_link *link;
534         struct tipc_node *node = tipc_node_find(addr);
535
536         if ((bearer_id >= MAX_BEARERS) || !node)
537                 return -EINVAL;
538         tipc_node_lock(node);
539         link = node->links[bearer_id];
540         if (link) {
541                 strncpy(linkname, link->name, len);
542                 tipc_node_unlock(node);
543                 return 0;
544         }
545         tipc_node_unlock(node);
546         return -EINVAL;
547 }
548
549 void tipc_node_unlock(struct tipc_node *node)
550 {
551         LIST_HEAD(nsub_list);
552         LIST_HEAD(conn_sks);
553         struct sk_buff_head waiting_sks;
554         u32 addr = 0;
555         int flags = node->action_flags;
556         u32 link_id = 0;
557
558         if (likely(!flags)) {
559                 spin_unlock_bh(&node->lock);
560                 return;
561         }
562
563         addr = node->addr;
564         link_id = node->link_id;
565         __skb_queue_head_init(&waiting_sks);
566
567         if (flags & TIPC_WAKEUP_USERS)
568                 skb_queue_splice_init(&node->waiting_sks, &waiting_sks);
569
570         if (flags & TIPC_NOTIFY_NODE_DOWN) {
571                 list_replace_init(&node->nsub, &nsub_list);
572                 list_replace_init(&node->conn_sks, &conn_sks);
573         }
574         node->action_flags &= ~(TIPC_WAKEUP_USERS | TIPC_NOTIFY_NODE_DOWN |
575                                 TIPC_NOTIFY_NODE_UP | TIPC_NOTIFY_LINK_UP |
576                                 TIPC_NOTIFY_LINK_DOWN |
577                                 TIPC_WAKEUP_BCAST_USERS);
578
579         spin_unlock_bh(&node->lock);
580
581         while (!skb_queue_empty(&waiting_sks))
582                 tipc_sk_rcv(__skb_dequeue(&waiting_sks));
583
584         if (!list_empty(&conn_sks))
585                 tipc_node_abort_sock_conns(&conn_sks);
586
587         if (!list_empty(&nsub_list))
588                 tipc_nodesub_notify(&nsub_list);
589
590         if (flags & TIPC_WAKEUP_BCAST_USERS)
591                 tipc_bclink_wakeup_users();
592
593         if (flags & TIPC_NOTIFY_NODE_UP)
594                 tipc_named_node_up(addr);
595
596         if (flags & TIPC_NOTIFY_LINK_UP)
597                 tipc_nametbl_publish(TIPC_LINK_STATE, addr, addr,
598                                      TIPC_NODE_SCOPE, link_id, addr);
599
600         if (flags & TIPC_NOTIFY_LINK_DOWN)
601                 tipc_nametbl_withdraw(TIPC_LINK_STATE, addr,
602                                       link_id, addr);
603 }