2 * net/tipc/name_distr.c: TIPC name distribution code
4 * Copyright (c) 2003-2005, Ericsson Research Canada
5 * Copyright (c) 2005, Wind River Systems
6 * Copyright (c) 2005-2006, Ericsson AB
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21 * Alternatively, this software may be distributed under the terms of the
22 * GNU General Public License ("GPL") version 2 as published by the Free
23 * Software Foundation.
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43 #include "name_distr.h"
46 #define DBG_OUTPUT NULL
48 #define ITEM_SIZE sizeof(struct distr_item)
51 * struct distr_item - publication info distributed to other nodes
52 * @type: name sequence type
53 * @lower: name sequence lower bound
54 * @upper: name sequence upper bound
55 * @ref: publishing port reference
56 * @key: publication key
58 * ===> All fields are stored in network byte order. <===
60 * First 3 fields identify (name or) name sequence being published.
61 * Reference field uniquely identifies port that published name sequence.
62 * Key field uniquely identifies publication, in the event a port has
63 * multiple publications of the same name sequence.
65 * Note: There is no field that identifies the publishing node because it is
66 * the same for all items contained within a publication message.
78 * List of externally visible publications by this node --
79 * that is, all publications having scope > TIPC_NODE_SCOPE.
82 static LIST_HEAD(publ_root);
83 static u32 publ_cnt = 0;
86 * publ_to_item - add publication info to a publication message
89 static void publ_to_item(struct distr_item *i, struct publication *p)
91 i->type = htonl(p->type);
92 i->lower = htonl(p->lower);
93 i->upper = htonl(p->upper);
94 i->ref = htonl(p->ref);
95 i->key = htonl(p->key);
96 dbg("publ_to_item: %u, %u, %u\n", p->type, p->lower, p->upper);
100 * named_prepare_buf - allocate & initialize a publication message
103 static struct sk_buff *named_prepare_buf(u32 type, u32 size, u32 dest)
105 struct sk_buff *buf = buf_acquire(LONG_H_SIZE + size);
106 struct tipc_msg *msg;
110 msg_init(msg, NAME_DISTRIBUTOR, type, TIPC_OK,
112 msg_set_size(msg, LONG_H_SIZE + size);
118 * named_publish - tell other nodes about a new publication by this node
121 void named_publish(struct publication *publ)
124 struct distr_item *item;
126 list_add(&publ->local_list, &publ_root);
129 buf = named_prepare_buf(PUBLICATION, ITEM_SIZE, 0);
131 warn("Memory squeeze; failed to distribute publication\n");
135 item = (struct distr_item *)msg_data(buf_msg(buf));
136 publ_to_item(item, publ);
137 dbg("named_withdraw: broadcasting publish msg\n");
138 cluster_broadcast(buf);
142 * named_withdraw - tell other nodes about a withdrawn publication by this node
145 void named_withdraw(struct publication *publ)
148 struct distr_item *item;
150 list_del(&publ->local_list);
153 buf = named_prepare_buf(WITHDRAWAL, ITEM_SIZE, 0);
155 warn("Memory squeeze; failed to distribute withdrawal\n");
159 item = (struct distr_item *)msg_data(buf_msg(buf));
160 publ_to_item(item, publ);
161 dbg("named_withdraw: broadcasting withdraw msg\n");
162 cluster_broadcast(buf);
166 * named_node_up - tell specified node about all publications by this node
169 void named_node_up(unsigned long node)
171 struct publication *publ;
172 struct distr_item *item = 0;
173 struct sk_buff *buf = 0;
178 assert(in_own_cluster(node));
179 read_lock_bh(&nametbl_lock);
180 max_item_buf = TIPC_MAX_USER_MSG_SIZE / ITEM_SIZE;
181 max_item_buf *= ITEM_SIZE;
182 rest = publ_cnt * ITEM_SIZE;
184 list_for_each_entry(publ, &publ_root, local_list) {
186 left = (rest <= max_item_buf) ? rest : max_item_buf;
188 buf = named_prepare_buf(PUBLICATION, left, node);
190 warn("Memory Squeeze; could not send publication\n");
193 item = (struct distr_item *)msg_data(buf_msg(buf));
195 publ_to_item(item, publ);
199 msg_set_link_selector(buf_msg(buf), node);
200 dbg("named_node_up: sending publish msg to "
201 "<%u.%u.%u>\n", tipc_zone(node),
202 tipc_cluster(node), tipc_node(node));
203 link_send(buf, node, node);
208 read_unlock_bh(&nametbl_lock);
212 * node_is_down - remove publication associated with a failed node
214 * Invoked for each publication issued by a newly failed node.
215 * Removes publication structure from name table & deletes it.
216 * In rare cases the link may have come back up again when this
217 * function is called, and we have two items representing the same
218 * publication. Nudge this item's key to distinguish it from the other.
219 * (Note: Publication's node subscription is already unsubscribed.)
222 static void node_is_down(struct publication *publ)
224 struct publication *p;
225 write_lock_bh(&nametbl_lock);
226 dbg("node_is_down: withdrawing %u, %u, %u\n",
227 publ->type, publ->lower, publ->upper);
228 publ->key += 1222345;
229 p = nametbl_remove_publ(publ->type, publ->lower,
230 publ->node, publ->ref, publ->key);
232 write_unlock_bh(&nametbl_lock);
238 * named_recv - process name table update message sent by another node
241 void named_recv(struct sk_buff *buf)
243 struct publication *publ;
244 struct tipc_msg *msg = buf_msg(buf);
245 struct distr_item *item = (struct distr_item *)msg_data(msg);
246 u32 count = msg_data_sz(msg) / ITEM_SIZE;
248 write_lock_bh(&nametbl_lock);
250 if (msg_type(msg) == PUBLICATION) {
251 dbg("named_recv: got publication for %u, %u, %u\n",
252 ntohl(item->type), ntohl(item->lower),
254 publ = nametbl_insert_publ(ntohl(item->type),
262 nodesub_subscribe(&publ->subscr,
265 (net_ev_handler)node_is_down);
267 } else if (msg_type(msg) == WITHDRAWAL) {
268 dbg("named_recv: got withdrawl for %u, %u, %u\n",
269 ntohl(item->type), ntohl(item->lower),
271 publ = nametbl_remove_publ(ntohl(item->type),
278 nodesub_unsubscribe(&publ->subscr);
282 warn("named_recv: unknown msg\n");
286 write_unlock_bh(&nametbl_lock);
291 * named_reinit - re-initialize local publication list
293 * This routine is called whenever TIPC networking is (re)enabled.
294 * All existing publications by this node that have "cluster" or "zone" scope
295 * are updated to reflect the node's current network address.
296 * (If the node's address is unchanged, the update loop terminates immediately.)
299 void named_reinit(void)
301 struct publication *publ;
303 write_lock_bh(&nametbl_lock);
304 list_for_each_entry(publ, &publ_root, local_list) {
305 if (publ->node == tipc_own_addr)
307 publ->node = tipc_own_addr;
309 write_unlock_bh(&nametbl_lock);