tipc: narrow down exposure of struct tipc_node

In our effort to have less code and include dependencies between
entities such as node, link and bearer, we try to narrow down
the exposed interface towards the node as much as possible.

In this commit, we move the definition of struct tipc_node, along
with many of its associated function declarations, from node.h to
node.c. We also move some function definitions from link.c and
name_distr.c to node.c, since they access fields in struct tipc_node
that should not be externally visible. The moved functions are renamed
according to new location, and made static whenever possible.

There are no functional changes in this commit.

Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 444 insertions, 5 deletions

diff --git a/net/tipc/node.c b/net/tipc/node.c
index 47d5f84c90c5..e110ba67422e 100644
--- a/net/tipc/node.c
+++ b/net/tipc/node.c
@@ -42,6 +42,87 @@
 #include "bcast.h"
 #include "discover.h"
 
+/* Out-of-range value for node signature */
+#define INVALID_NODE_SIG	0x10000
+
+#define INVALID_BEARER_ID -1
+
+/* Flags used to take different actions according to flag type
+ * TIPC_NOTIFY_NODE_DOWN: notify node is down
+ * TIPC_NOTIFY_NODE_UP: notify node is up
+ * TIPC_DISTRIBUTE_NAME: publish or withdraw link state name type
+ */
+enum {
+	TIPC_NOTIFY_NODE_DOWN		= (1 << 3),
+	TIPC_NOTIFY_NODE_UP		= (1 << 4),
+	TIPC_NOTIFY_LINK_UP		= (1 << 6),
+	TIPC_NOTIFY_LINK_DOWN		= (1 << 7)
+};
+
+struct tipc_link_entry {
+	struct tipc_link *link;
+	spinlock_t lock; /* per link */
+	u32 mtu;
+	struct sk_buff_head inputq;
+	struct tipc_media_addr maddr;
+};
+
+struct tipc_bclink_entry {
+	struct tipc_link *link;
+	struct sk_buff_head inputq1;
+	struct sk_buff_head arrvq;
+	struct sk_buff_head inputq2;
+	struct sk_buff_head namedq;
+};
+
+/**
+ * struct tipc_node - TIPC node structure
+ * @addr: network address of node
+ * @ref: reference counter to node object
+ * @lock: rwlock governing access to structure
+ * @net: the applicable net namespace
+ * @hash: links to adjacent nodes in unsorted hash chain
+ * @inputq: pointer to input queue containing messages for msg event
+ * @namedq: pointer to name table input queue with name table messages
+ * @active_links: bearer ids of active links, used as index into links[] array
+ * @links: array containing references to all links to node
+ * @action_flags: bit mask of different types of node actions
+ * @state: connectivity state vs peer node
+ * @sync_point: sequence number where synch/failover is finished
+ * @list: links to adjacent nodes in sorted list of cluster's nodes
+ * @working_links: number of working links to node (both active and standby)
+ * @link_cnt: number of links to node
+ * @capabilities: bitmap, indicating peer node's functional capabilities
+ * @signature: node instance identifier
+ * @link_id: local and remote bearer ids of changing link, if any
+ * @publ_list: list of publications
+ * @rcu: rcu struct for tipc_node
+ */
+struct tipc_node {
+	u32 addr;
+	struct kref kref;
+	rwlock_t lock;
+	struct net *net;
+	struct hlist_node hash;
+	int active_links[2];
+	struct tipc_link_entry links[MAX_BEARERS];
+	struct tipc_bclink_entry bc_entry;
+	int action_flags;
+	struct list_head list;
+	int state;
+	u16 sync_point;
+	int link_cnt;
+	u16 working_links;
+	u16 capabilities;
+	u32 signature;
+	u32 link_id;
+	struct list_head publ_list;
+	struct list_head conn_sks;
+	unsigned long keepalive_intv;
+	struct timer_list timer;
+	struct rcu_head rcu;
+};
+
 /* Node FSM states and events:
  */
 enum {
@@ -75,6 +156,9 @@ static void node_lost_contact(struct tipc_node *n, struct sk_buff_head *inputq);
 static void tipc_node_delete(struct tipc_node *node);
 static void tipc_node_timeout(unsigned long data);
 static void tipc_node_fsm_evt(struct tipc_node *n, int evt);
+static struct tipc_node *tipc_node_find(struct net *net, u32 addr);
+static void tipc_node_put(struct tipc_node *node);
+static bool tipc_node_is_up(struct tipc_node *n);
 
 struct tipc_sock_conn {
 	u32 port;
@@ -83,12 +167,54 @@ struct tipc_sock_conn {
 	struct list_head list;
 };
 
+static const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
+	[TIPC_NLA_LINK_UNSPEC]		= { .type = NLA_UNSPEC },
+	[TIPC_NLA_LINK_NAME] = {
+		.type = NLA_STRING,
+		.len = TIPC_MAX_LINK_NAME
+	},
+	[TIPC_NLA_LINK_MTU]		= { .type = NLA_U32 },
+	[TIPC_NLA_LINK_BROADCAST]	= { .type = NLA_FLAG },
+	[TIPC_NLA_LINK_UP]		= { .type = NLA_FLAG },
+	[TIPC_NLA_LINK_ACTIVE]		= { .type = NLA_FLAG },
+	[TIPC_NLA_LINK_PROP]		= { .type = NLA_NESTED },
+	[TIPC_NLA_LINK_STATS]		= { .type = NLA_NESTED },
+	[TIPC_NLA_LINK_RX]		= { .type = NLA_U32 },
+	[TIPC_NLA_LINK_TX]		= { .type = NLA_U32 }
+};
+
 static const struct nla_policy tipc_nl_node_policy[TIPC_NLA_NODE_MAX + 1] = {
 	[TIPC_NLA_NODE_UNSPEC]		= { .type = NLA_UNSPEC },
 	[TIPC_NLA_NODE_ADDR]		= { .type = NLA_U32 },
 	[TIPC_NLA_NODE_UP]		= { .type = NLA_FLAG }
 };
 
+static struct tipc_link *node_active_link(struct tipc_node *n, int sel)
+{
+	int bearer_id = n->active_links[sel & 1];
+
+	if (unlikely(bearer_id == INVALID_BEARER_ID))
+		return NULL;
+
+	return n->links[bearer_id].link;
+}
+
+int tipc_node_get_mtu(struct net *net, u32 addr, u32 sel)
+{
+	struct tipc_node *n;
+	int bearer_id;
+	unsigned int mtu = MAX_MSG_SIZE;
+
+	n = tipc_node_find(net, addr);
+	if (unlikely(!n))
+		return mtu;
+
+	bearer_id = n->active_links[sel & 1];
+	if (likely(bearer_id != INVALID_BEARER_ID))
+		mtu = n->links[bearer_id].mtu;
+	tipc_node_put(n);
+	return mtu;
+}
 /*
  * A trivial power-of-two bitmask technique is used for speed, since this
  * operation is done for every incoming TIPC packet. The number of hash table
@@ -107,7 +233,7 @@ static void tipc_node_kref_release(struct kref *kref)
 	tipc_node_delete(node);
 }
 
-void tipc_node_put(struct tipc_node *node)
+static void tipc_node_put(struct tipc_node *node)
 {
 	kref_put(&node->kref, tipc_node_kref_release);
 }
@@ -120,7 +246,7 @@ static void tipc_node_get(struct tipc_node *node)
 /*
  * tipc_node_find - locate specified node object, if it exists
  */
-struct tipc_node *tipc_node_find(struct net *net, u32 addr)
+static struct tipc_node *tipc_node_find(struct net *net, u32 addr)
 {
 	struct tipc_net *tn = net_generic(net, tipc_net_id);
 	struct tipc_node *node;
@@ -141,12 +267,12 @@ struct tipc_node *tipc_node_find(struct net *net, u32 addr)
 	return NULL;
 }
 
-void tipc_node_read_lock(struct tipc_node *n)
+static void tipc_node_read_lock(struct tipc_node *n)
 {
 	read_lock_bh(&n->lock);
 }
 
-void tipc_node_read_unlock(struct tipc_node *n)
+static void tipc_node_read_unlock(struct tipc_node *n)
 {
 	read_unlock_bh(&n->lock);
 }
@@ -588,7 +714,7 @@ static void tipc_node_link_down(struct tipc_node *n, int bearer_id, bool delete)
 	tipc_sk_rcv(n->net, &le->inputq);
 }
 
-bool tipc_node_is_up(struct tipc_node *n)
+static bool tipc_node_is_up(struct tipc_node *n)
 {
 	return n->active_links[0] != INVALID_BEARER_ID;
 }
@@ -1465,3 +1591,316 @@ out:
 
 	return skb->len;
 }
+
+/* tipc_link_find_owner - locate owner node of link by link's name
+ * @net: the applicable net namespace
+ * @name: pointer to link name string
+ * @bearer_id: pointer to index in 'node->links' array where the link was found.
+ *
+ * Returns pointer to node owning the link, or 0 if no matching link is found.
+ */
+static struct tipc_node *tipc_link_find_owner(struct net *net,
+					      const char *link_name,
+					      unsigned int *bearer_id)
+{
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_link *l_ptr;
+	struct tipc_node *n_ptr;
+	struct tipc_node *found_node = NULL;
+	int i;
+
+	*bearer_id = 0;
+	rcu_read_lock();
+	list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
+		tipc_node_read_lock(n_ptr);
+		for (i = 0; i < MAX_BEARERS; i++) {
+			l_ptr = n_ptr->links[i].link;
+			if (l_ptr && !strcmp(l_ptr->name, link_name)) {
+				*bearer_id = i;
+				found_node = n_ptr;
+				break;
+			}
+		}
+		tipc_node_read_unlock(n_ptr);
+		if (found_node)
+			break;
+	}
+	rcu_read_unlock();
+
+	return found_node;
+}
+
+int tipc_nl_node_set_link(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+	int res = 0;
+	int bearer_id;
+	char *name;
+	struct tipc_link *link;
+	struct tipc_node *node;
+	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
+	struct net *net = sock_net(skb->sk);
+
+	if (!info->attrs[TIPC_NLA_LINK])
+		return -EINVAL;
+
+	err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
+			       info->attrs[TIPC_NLA_LINK],
+			       tipc_nl_link_policy);
+	if (err)
+		return err;
+
+	if (!attrs[TIPC_NLA_LINK_NAME])
+		return -EINVAL;
+
+	name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
+
+	if (strcmp(name, tipc_bclink_name) == 0)
+		return tipc_nl_bc_link_set(net, attrs);
+
+	node = tipc_link_find_owner(net, name, &bearer_id);
+	if (!node)
+		return -EINVAL;
+
+	tipc_node_read_lock(node);
+
+	link = node->links[bearer_id].link;
+	if (!link) {
+		res = -EINVAL;
+		goto out;
+	}
+
+	if (attrs[TIPC_NLA_LINK_PROP]) {
+		struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
+
+		err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
+					      props);
+		if (err) {
+			res = err;
+			goto out;
+		}
+
+		if (props[TIPC_NLA_PROP_TOL]) {
+			u32 tol;
+
+			tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
+			link->tolerance = tol;
+			tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
+		}
+		if (props[TIPC_NLA_PROP_PRIO]) {
+			u32 prio;
+
+			prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
+			link->priority = prio;
+			tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
+		}
+		if (props[TIPC_NLA_PROP_WIN]) {
+			u32 win;
+
+			win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
+			tipc_link_set_queue_limits(link, win);
+		}
+	}
+
+out:
+	tipc_node_read_unlock(node);
+
+	return res;
+}
+
+int tipc_nl_node_get_link(struct sk_buff *skb, struct genl_info *info)
+{
+	struct net *net = genl_info_net(info);
+	struct tipc_nl_msg msg;
+	char *name;
+	int err;
+
+	msg.portid = info->snd_portid;
+	msg.seq = info->snd_seq;
+
+	if (!info->attrs[TIPC_NLA_LINK_NAME])
+		return -EINVAL;
+	name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
+
+	msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!msg.skb)
+		return -ENOMEM;
+
+	if (strcmp(name, tipc_bclink_name) == 0) {
+		err = tipc_nl_add_bc_link(net, &msg);
+		if (err) {
+			nlmsg_free(msg.skb);
+			return err;
+		}
+	} else {
+		int bearer_id;
+		struct tipc_node *node;
+		struct tipc_link *link;
+
+		node = tipc_link_find_owner(net, name, &bearer_id);
+		if (!node)
+			return -EINVAL;
+
+		tipc_node_read_lock(node);
+		link = node->links[bearer_id].link;
+		if (!link) {
+			tipc_node_read_unlock(node);
+			nlmsg_free(msg.skb);
+			return -EINVAL;
+		}
+
+		err = __tipc_nl_add_link(net, &msg, link, 0);
+		tipc_node_read_unlock(node);
+		if (err) {
+			nlmsg_free(msg.skb);
+			return err;
+		}
+	}
+
+	return genlmsg_reply(msg.skb, info);
+}
+
+int tipc_nl_node_reset_link_stats(struct sk_buff *skb, struct genl_info *info)
+{
+	int err;
+	char *link_name;
+	unsigned int bearer_id;
+	struct tipc_link *link;
+	struct tipc_node *node;
+	struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
+	struct net *net = sock_net(skb->sk);
+	struct tipc_link_entry *le;
+
+	if (!info->attrs[TIPC_NLA_LINK])
+		return -EINVAL;
+
+	err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
+			       info->attrs[TIPC_NLA_LINK],
+			       tipc_nl_link_policy);
+	if (err)
+		return err;
+
+	if (!attrs[TIPC_NLA_LINK_NAME])
+		return -EINVAL;
+
+	link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
+
+	if (strcmp(link_name, tipc_bclink_name) == 0) {
+		err = tipc_bclink_reset_stats(net);
+		if (err)
+			return err;
+		return 0;
+	}
+
+	node = tipc_link_find_owner(net, link_name, &bearer_id);
+	if (!node)
+		return -EINVAL;
+
+	le = &node->links[bearer_id];
+	tipc_node_read_lock(node);
+	spin_lock_bh(&le->lock);
+	link = node->links[bearer_id].link;
+	if (!link) {
+		spin_unlock_bh(&le->lock);
+		tipc_node_read_unlock(node);
+		return -EINVAL;
+	}
+	link_reset_statistics(link);
+	spin_unlock_bh(&le->lock);
+	tipc_node_read_unlock(node);
+	return 0;
+}
+
+/* Caller should hold node lock  */
+static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
+				    struct tipc_node *node, u32 *prev_link)
+{
+	u32 i;
+	int err;
+
+	for (i = *prev_link; i < MAX_BEARERS; i++) {
+		*prev_link = i;
+
+		if (!node->links[i].link)
+			continue;
+
+		err = __tipc_nl_add_link(net, msg,
+					 node->links[i].link, NLM_F_MULTI);
+		if (err)
+			return err;
+	}
+	*prev_link = 0;
+
+	return 0;
+}
+
+int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct net *net = sock_net(skb->sk);
+	struct tipc_net *tn = net_generic(net, tipc_net_id);
+	struct tipc_node *node;
+	struct tipc_nl_msg msg;
+	u32 prev_node = cb->args[0];
+	u32 prev_link = cb->args[1];
+	int done = cb->args[2];
+	int err;
+
+	if (done)
+		return 0;
+
+	msg.skb = skb;
+	msg.portid = NETLINK_CB(cb->skb).portid;
+	msg.seq = cb->nlh->nlmsg_seq;
+
+	rcu_read_lock();
+	if (prev_node) {
+		node = tipc_node_find(net, prev_node);
+		if (!node) {
+			/* We never set seq or call nl_dump_check_consistent()
+			 * this means that setting prev_seq here will cause the
+			 * consistence check to fail in the netlink callback
+			 * handler. Resulting in the last NLMSG_DONE message
+			 * having the NLM_F_DUMP_INTR flag set.
+			 */
+			cb->prev_seq = 1;
+			goto out;
+		}
+		tipc_node_put(node);
+
+		list_for_each_entry_continue_rcu(node, &tn->node_list,
+						 list) {
+			tipc_node_read_lock(node);
+			err = __tipc_nl_add_node_links(net, &msg, node,
+						       &prev_link);
+			tipc_node_read_unlock(node);
+			if (err)
+				goto out;
+
+			prev_node = node->addr;
+		}
+	} else {
+		err = tipc_nl_add_bc_link(net, &msg);
+		if (err)
+			goto out;
+
+		list_for_each_entry_rcu(node, &tn->node_list, list) {
+			tipc_node_read_lock(node);
+			err = __tipc_nl_add_node_links(net, &msg, node,
+						       &prev_link);
+			tipc_node_read_unlock(node);
+			if (err)
+				goto out;
+
+			prev_node = node->addr;
+		}
+	}
+	done = 1;
+out:
+	rcu_read_unlock();
+
+	cb->args[0] = prev_node;
+	cb->args[1] = prev_link;
+	cb->args[2] = done;
+
+	return skb->len;
+}