name_table.c

linux 内核源代码

	seq_head = &table.types[hash(type)];
	hlist_for_each_entry(ns, seq_node, seq_head, ns_list) {
		if (ns->type == type) {
			dbg("found %p\n", ns);
			return ns;
		}
	}

	return NULL;
};

struct publication *tipc_nametbl_insert_publ(u32 type, u32 lower, u32 upper,
					     u32 scope, u32 node, u32 port, u32 key)
{
	struct name_seq *seq = nametbl_find_seq(type);

	dbg("tipc_nametbl_insert_publ: {%u,%u,%u} found %p\n", type, lower, upper, seq);
	if (lower > upper) {
		warn("Failed to publish illegal {%u,%u,%u}\n",
		     type, lower, upper);
		return NULL;
	}

	dbg("Publishing {%u,%u,%u} from 0x%x\n", type, lower, upper, node);
	if (!seq) {
		seq = tipc_nameseq_create(type, &table.types[hash(type)]);
		dbg("tipc_nametbl_insert_publ: created %p\n", seq);
	}
	if (!seq)
		return NULL;

	return tipc_nameseq_insert_publ(seq, type, lower, upper,
					scope, node, port, key);
}

struct publication *tipc_nametbl_remove_publ(u32 type, u32 lower,
					     u32 node, u32 ref, u32 key)
{
	struct publication *publ;
	struct name_seq *seq = nametbl_find_seq(type);

	if (!seq)
		return NULL;

	dbg("Withdrawing {%u,%u} from 0x%x\n", type, lower, node);
	publ = tipc_nameseq_remove_publ(seq, lower, node, ref, key);

	if (!seq->first_free && list_empty(&seq->subscriptions)) {
		hlist_del_init(&seq->ns_list);
		kfree(seq->sseqs);
		kfree(seq);
	}
	return publ;
}

/*
 * tipc_nametbl_translate(): Translate tipc_name -> tipc_portid.
 *                      Very time-critical.
 *
 * Note: on entry 'destnode' is the search domain used during translation;
 *       on exit it passes back the node address of the matching port (if any)
 */

u32 tipc_nametbl_translate(u32 type, u32 instance, u32 *destnode)
{
	struct sub_seq *sseq;
	struct publication *publ = NULL;
	struct name_seq *seq;
	u32 ref;

	if (!in_scope(*destnode, tipc_own_addr))
		return 0;

	read_lock_bh(&tipc_nametbl_lock);
	seq = nametbl_find_seq(type);
	if (unlikely(!seq))
		goto not_found;
	sseq = nameseq_find_subseq(seq, instance);
	if (unlikely(!sseq))
		goto not_found;
	spin_lock_bh(&seq->lock);

	/* Closest-First Algorithm: */
	if (likely(!*destnode)) {
		publ = sseq->node_list;
		if (publ) {
			sseq->node_list = publ->node_list_next;
found:
			ref = publ->ref;
			*destnode = publ->node;
			spin_unlock_bh(&seq->lock);
			read_unlock_bh(&tipc_nametbl_lock);
			return ref;
		}
		publ = sseq->cluster_list;
		if (publ) {
			sseq->cluster_list = publ->cluster_list_next;
			goto found;
		}
		publ = sseq->zone_list;
		if (publ) {
			sseq->zone_list = publ->zone_list_next;
			goto found;
		}
	}

	/* Round-Robin Algorithm: */
	else if (*destnode == tipc_own_addr) {
		publ = sseq->node_list;
		if (publ) {
			sseq->node_list = publ->node_list_next;
			goto found;
		}
	} else if (in_own_cluster(*destnode)) {
		publ = sseq->cluster_list;
		if (publ) {
			sseq->cluster_list = publ->cluster_list_next;
			goto found;
		}
	} else {
		publ = sseq->zone_list;
		if (publ) {
			sseq->zone_list = publ->zone_list_next;
			goto found;
		}
	}
	spin_unlock_bh(&seq->lock);
not_found:
	*destnode = 0;
	read_unlock_bh(&tipc_nametbl_lock);
	return 0;
}

/**
 * tipc_nametbl_mc_translate - find multicast destinations
 *
 * Creates list of all local ports that overlap the given multicast address;
 * also determines if any off-node ports overlap.
 *
 * Note: Publications with a scope narrower than 'limit' are ignored.
 * (i.e. local node-scope publications mustn't receive messages arriving
 * from another node, even if the multcast link brought it here)
 *
 * Returns non-zero if any off-node ports overlap
 */

int tipc_nametbl_mc_translate(u32 type, u32 lower, u32 upper, u32 limit,
			      struct port_list *dports)
{
	struct name_seq *seq;
	struct sub_seq *sseq;
	struct sub_seq *sseq_stop;
	int res = 0;

	read_lock_bh(&tipc_nametbl_lock);
	seq = nametbl_find_seq(type);
	if (!seq)
		goto exit;

	spin_lock_bh(&seq->lock);

	sseq = seq->sseqs + nameseq_locate_subseq(seq, lower);
	sseq_stop = seq->sseqs + seq->first_free;
	for (; sseq != sseq_stop; sseq++) {
		struct publication *publ;

		if (sseq->lower > upper)
			break;
		publ = sseq->cluster_list;
		if (publ && (publ->scope <= limit))
			do {
				if (publ->node == tipc_own_addr)
					tipc_port_list_add(dports, publ->ref);
				else
					res = 1;
				publ = publ->cluster_list_next;
			} while (publ != sseq->cluster_list);
	}

	spin_unlock_bh(&seq->lock);
exit:
	read_unlock_bh(&tipc_nametbl_lock);
	return res;
}

/**
 * tipc_nametbl_publish_rsv - publish port name using a reserved name type
 */

int tipc_nametbl_publish_rsv(u32 ref, unsigned int scope,
			struct tipc_name_seq const *seq)
{
	int res;

	atomic_inc(&rsv_publ_ok);
	res = tipc_publish(ref, scope, seq);
	atomic_dec(&rsv_publ_ok);
	return res;
}

/**
 * tipc_nametbl_publish - add name publication to network name tables
 */

struct publication *tipc_nametbl_publish(u32 type, u32 lower, u32 upper,
				    u32 scope, u32 port_ref, u32 key)
{
	struct publication *publ;

	if (table.local_publ_count >= tipc_max_publications) {
		warn("Publication failed, local publication limit reached (%u)\n",
		     tipc_max_publications);
		return NULL;
	}
	if ((type < TIPC_RESERVED_TYPES) && !atomic_read(&rsv_publ_ok)) {
		warn("Publication failed, reserved name {%u,%u,%u}\n",
		     type, lower, upper);
		return NULL;
	}

	write_lock_bh(&tipc_nametbl_lock);
	table.local_publ_count++;
	publ = tipc_nametbl_insert_publ(type, lower, upper, scope,
				   tipc_own_addr, port_ref, key);
	if (publ && (scope != TIPC_NODE_SCOPE)) {
		tipc_named_publish(publ);
	}
	write_unlock_bh(&tipc_nametbl_lock);
	return publ;
}

/**
 * tipc_nametbl_withdraw - withdraw name publication from network name tables
 */

int tipc_nametbl_withdraw(u32 type, u32 lower, u32 ref, u32 key)
{
	struct publication *publ;

	dbg("tipc_nametbl_withdraw: {%u,%u}, key=%u\n", type, lower, key);
	write_lock_bh(&tipc_nametbl_lock);
	publ = tipc_nametbl_remove_publ(type, lower, tipc_own_addr, ref, key);
	if (likely(publ)) {
		table.local_publ_count--;
		if (publ->scope != TIPC_NODE_SCOPE)
			tipc_named_withdraw(publ);
		write_unlock_bh(&tipc_nametbl_lock);
		list_del_init(&publ->pport_list);
		kfree(publ);
		return 1;
	}
	write_unlock_bh(&tipc_nametbl_lock);
	err("Unable to remove local publication\n"
	    "(type=%u, lower=%u, ref=%u, key=%u)\n",
	    type, lower, ref, key);
	return 0;
}

/**
 * tipc_nametbl_subscribe - add a subscription object to the name table
 */

void tipc_nametbl_subscribe(struct subscription *s)
{
	u32 type = s->seq.type;
	struct name_seq *seq;

	write_lock_bh(&tipc_nametbl_lock);
	seq = nametbl_find_seq(type);
	if (!seq) {
		seq = tipc_nameseq_create(type, &table.types[hash(type)]);
	}
	if (seq){
		spin_lock_bh(&seq->lock);
		dbg("tipc_nametbl_subscribe:found %p for {%u,%u,%u}\n",
		    seq, type, s->seq.lower, s->seq.upper);
		tipc_nameseq_subscribe(seq, s);
		spin_unlock_bh(&seq->lock);
	} else {
		warn("Failed to create subscription for {%u,%u,%u}\n",
		     s->seq.type, s->seq.lower, s->seq.upper);
	}
	write_unlock_bh(&tipc_nametbl_lock);
}

/**
 * tipc_nametbl_unsubscribe - remove a subscription object from name table
 */

void tipc_nametbl_unsubscribe(struct subscription *s)
{
	struct name_seq *seq;

	write_lock_bh(&tipc_nametbl_lock);
	seq = nametbl_find_seq(s->seq.type);
	if (seq != NULL){
		spin_lock_bh(&seq->lock);
		list_del_init(&s->nameseq_list);
		spin_unlock_bh(&seq->lock);
		if ((seq->first_free == 0) && list_empty(&seq->subscriptions)) {
			hlist_del_init(&seq->ns_list);
			kfree(seq->sseqs);
			kfree(seq);
		}
	}
	write_unlock_bh(&tipc_nametbl_lock);
}


/**
 * subseq_list: print specified sub-sequence contents into the given buffer
 */

static void subseq_list(struct sub_seq *sseq, struct print_buf *buf, u32 depth,
			u32 index)
{
	char portIdStr[27];
	char *scopeStr;
	struct publication *publ = sseq->zone_list;

	tipc_printf(buf, "%-10u %-10u ", sseq->lower, sseq->upper);

	if (depth == 2 || !publ) {
		tipc_printf(buf, "\n");
		return;
	}

	do {
		sprintf (portIdStr, "<%u.%u.%u:%u>",
			 tipc_zone(publ->node), tipc_cluster(publ->node),
			 tipc_node(publ->node), publ->ref);
		tipc_printf(buf, "%-26s ", portIdStr);
		if (depth > 3) {
			if (publ->node != tipc_own_addr)
				scopeStr = "";
			else if (publ->scope == TIPC_NODE_SCOPE)
				scopeStr = "node";
			else if (publ->scope == TIPC_CLUSTER_SCOPE)
				scopeStr = "cluster";
			else
				scopeStr = "zone";
			tipc_printf(buf, "%-10u %s", publ->key, scopeStr);
		}

		publ = publ->zone_list_next;
		if (publ == sseq->zone_list)
			break;

		tipc_printf(buf, "\n%33s", " ");
	} while (1);

	tipc_printf(buf, "\n");
}

/**
 * nameseq_list: print specified name sequence contents into the given buffer
 */

static void nameseq_list(struct name_seq *seq, struct print_buf *buf, u32 depth,
			 u32 type, u32 lowbound, u32 upbound, u32 index)
{
	struct sub_seq *sseq;
	char typearea[11];

	sprintf(typearea, "%-10u", seq->type);

	if (depth == 1) {
		tipc_printf(buf, "%s\n", typearea);
		return;
	}

	for (sseq = seq->sseqs; sseq != &seq->sseqs[seq->first_free]; sseq++) {
		if ((lowbound <= sseq->upper) && (upbound >= sseq->lower)) {
			tipc_printf(buf, "%s ", typearea);
			subseq_list(sseq, buf, depth, index);
			sprintf(typearea, "%10s", " ");
		}
	}
}

/**
 * nametbl_header - print name table header into the given buffer
 */

static void nametbl_header(struct print_buf *buf, u32 depth)
{
	tipc_printf(buf, "Type       ");

	if (depth > 1)
		tipc_printf(buf, "Lower      Upper      ");
	if (depth > 2)
		tipc_printf(buf, "Port Identity              ");
	if (depth > 3)
		tipc_printf(buf, "Publication");

	tipc_printf(buf, "\n-----------");

	if (depth > 1)
		tipc_printf(buf, "--------------------- ");
	if (depth > 2)
		tipc_printf(buf, "-------------------------- ");
	if (depth > 3)
		tipc_printf(buf, "------------------");

	tipc_printf(buf, "\n");
}

/**
 * nametbl_list - print specified name table contents into the given buffer
 */

static void nametbl_list(struct print_buf *buf, u32 depth_info,
			 u32 type, u32 lowbound, u32 upbound)
{
	struct hlist_head *seq_head;
	struct hlist_node *seq_node;
	struct name_seq *seq;
	int all_types;
	u32 depth;
	u32 i;

	all_types = (depth_info & TIPC_NTQ_ALLTYPES);
	depth = (depth_info & ~TIPC_NTQ_ALLTYPES);

	if (depth == 0)
		return;

	if (all_types) {
		/* display all entries in name table to specified depth */
		nametbl_header(buf, depth);
		lowbound = 0;
		upbound = ~0;
		for (i = 0; i < tipc_nametbl_size; i++) {
			seq_head = &table.types[i];
			hlist_for_each_entry(seq, seq_node, seq_head, ns_list) {
				nameseq_list(seq, buf, depth, seq->type,
					     lowbound, upbound, i);
			}
		}
	} else {
		/* display only the sequence that matches the specified type */
		if (upbound < lowbound) {
			tipc_printf(buf, "invalid name sequence specified\n");
			return;
		}
		nametbl_header(buf, depth);
		i = hash(type);
		seq_head = &table.types[i];
		hlist_for_each_entry(seq, seq_node, seq_head, ns_list) {
			if (seq->type == type) {
				nameseq_list(seq, buf, depth, type,
					     lowbound, upbound, i);
				break;
			}
		}
	}
}

#if 0
void tipc_nametbl_print(struct print_buf *buf, const char *str)
{
	tipc_printf(buf, str);
	read_lock_bh(&tipc_nametbl_lock);
	nametbl_list(buf, 0, 0, 0, 0);
	read_unlock_bh(&tipc_nametbl_lock);
}
#endif

#define MAX_NAME_TBL_QUERY 32768

struct sk_buff *tipc_nametbl_get(const void *req_tlv_area, int req_tlv_space)
{
	struct sk_buff *buf;
	struct tipc_name_table_query *argv;
	struct tlv_desc *rep_tlv;
	struct print_buf b;
	int str_len;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NAME_TBL_QUERY))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

	buf = tipc_cfg_reply_alloc(TLV_SPACE(MAX_NAME_TBL_QUERY));
	if (!buf)
		return NULL;

	rep_tlv = (struct tlv_desc *)buf->data;
	tipc_printbuf_init(&b, TLV_DATA(rep_tlv), MAX_NAME_TBL_QUERY);
	argv = (struct tipc_name_table_query *)TLV_DATA(req_tlv_area);
	read_lock_bh(&tipc_nametbl_lock);
	nametbl_list(&b, ntohl(argv->depth), ntohl(argv->type),
		     ntohl(argv->lowbound), ntohl(argv->upbound));
	read_unlock_bh(&tipc_nametbl_lock);
	str_len = tipc_printbuf_validate(&b);

	skb_put(buf, TLV_SPACE(str_len));
	TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);

	return buf;
}

#if 0
void tipc_nametbl_dump(void)
{
	nametbl_list(TIPC_CONS, 0, 0, 0, 0);
}
#endif

int tipc_nametbl_init(void)
{
	int array_size = sizeof(struct hlist_head) * tipc_nametbl_size;

	table.types = kzalloc(array_size, GFP_ATOMIC);
	if (!table.types)
		return -ENOMEM;

	write_lock_bh(&tipc_nametbl_lock);
	table.local_publ_count = 0;
	write_unlock_bh(&tipc_nametbl_lock);
	return 0;
}

void tipc_nametbl_stop(void)
{
	u32 i;

	if (!table.types)
		return;

	/* Verify name table is empty, then release it */

	write_lock_bh(&tipc_nametbl_lock);
	for (i = 0; i < tipc_nametbl_size; i++) {
		if (!hlist_empty(&table.types[i]))
			err("tipc_nametbl_stop(): hash chain %u is non-null\n", i);
	}
	kfree(table.types);
	table.types = NULL;
	write_unlock_bh(&tipc_nametbl_lock);
}