Merge branch 'tipc-next'

Erik Hugne says:

====================
tipc: add support for link state subscriptions

Low level topology information like TIPC link up/down is useful for
applications like teamd to make smarter failover decisions in a
HA cluster environment. Fetching logical link names through an ioctl
may hurt the eyes of some. Suggestions for a more elegant way of doing
this would be appreciated in that case. :)

v2:
   -Properly based on net-next
   -Off-list comments from Billie Alsup:
    -Add a string length parameter to tipc_node_get_linkname
    -Use TIPC_MAX_LINK_NAME definition instead of hardcoded
     value in tipc_sioc_ln_req linkname
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/tipc.h

@@ -38,6 +38,7 @@
 #define _LINUX_TIPC_H_
 
 #include <linux/types.h>
+#include <linux/sockios.h>
 
 /*
  * TIPC addressing primitives
@@ -87,6 +88,7 @@ static inline unsigned int tipc_node(__u32 addr)
 
 #define TIPC_CFG_SRV		0	/* configuration service name type */
 #define TIPC_TOP_SRV		1	/* topology service name type */
+#define TIPC_LINK_STATE		2	/* link state name type */
 #define TIPC_RESERVED_TYPES	64	/* lowest user-publishable name type */
 
 /*
@@ -206,4 +208,25 @@ struct sockaddr_tipc {
 #define TIPC_NODE_RECVQ_DEPTH	131	/* Default: none (read only) */
 #define TIPC_SOCK_RECVQ_DEPTH	132	/* Default: none (read only) */
 
+/*
+ * Maximum sizes of TIPC bearer-related names (including terminating NULL)
+ * The string formatting for each name element is:
+ * media: media
+ * interface: media:interface name
+ * link: Z.C.N:interface-Z.C.N:interface
+ *
+ */
+
+#define TIPC_MAX_MEDIA_NAME	16
+#define TIPC_MAX_IF_NAME	16
+#define TIPC_MAX_BEARER_NAME	32
+#define TIPC_MAX_LINK_NAME	60
+
+#define SIOCGETLINKNAME		SIOCPROTOPRIVATE
+
+struct tipc_sioc_ln_req {
+	__u32 peer;
+	__u32 bearer_id;
+	char linkname[TIPC_MAX_LINK_NAME];
+};
 #endif

include/uapi/linux/tipc_config.h

@@ -39,6 +39,7 @@
 
 #include <linux/types.h>
 #include <linux/string.h>
+#include <linux/tipc.h>
 #include <asm/byteorder.h>
 
 #ifndef __KERNEL__
@@ -154,15 +155,6 @@
 #define TIPC_TLV_NAME_TBL_QUERY	25	/* struct tipc_name_table_query */
 #define TIPC_TLV_PORT_REF	26	/* 32-bit port reference */
 
-/*
- * Maximum sizes of TIPC bearer-related names (including terminating NUL)
- */
-
-#define TIPC_MAX_MEDIA_NAME	16	/* format = media */
-#define TIPC_MAX_IF_NAME	16	/* format = interface */
-#define TIPC_MAX_BEARER_NAME	32	/* format = media:interface */
-#define TIPC_MAX_LINK_NAME	60	/* format = Z.C.N:interface-Z.C.N:interface */
-
 /*
  * Link priority limits (min, default, max, media default)
  */

net/tipc/node.c

@@ -144,9 +144,11 @@ void tipc_node_stop(void)
 void tipc_node_link_up(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 {
 	struct tipc_link **active = &n_ptr->active_links[0];
+	u32 addr = n_ptr->addr;
 
 	n_ptr->working_links++;
-
+	tipc_nametbl_publish(TIPC_LINK_STATE, addr, addr, TIPC_NODE_SCOPE,
+			     l_ptr->bearer_id, addr);
 	pr_info("Established link <%s> on network plane %c\n",
 		l_ptr->name, l_ptr->net_plane);
 
@@ -203,8 +205,10 @@ static void node_select_active_links(struct tipc_node *n_ptr)
 void tipc_node_link_down(struct tipc_node *n_ptr, struct tipc_link *l_ptr)
 {
 	struct tipc_link **active;
+	u32 addr = n_ptr->addr;
 
 	n_ptr->working_links--;
+	tipc_nametbl_withdraw(TIPC_LINK_STATE, addr, l_ptr->bearer_id, addr);
 
 	if (!tipc_link_is_active(l_ptr)) {
 		pr_info("Lost standby link <%s> on network plane %c\n",
@@ -434,3 +438,30 @@ struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space)
 	rcu_read_unlock();
 	return buf;
 }
+
+/**
+ * tipc_node_get_linkname - get the name of a link
+ *
+ * @bearer_id: id of the bearer
+ * @node: peer node address
+ * @linkname: link name output buffer
+ *
+ * Returns 0 on success
+ */
+int tipc_node_get_linkname(u32 bearer_id, u32 addr, char *linkname, size_t len)
+{
+	struct tipc_link *link;
+	struct tipc_node *node = tipc_node_find(addr);
+
+	if ((bearer_id > MAX_BEARERS) || !node)
+		return -EINVAL;
+	tipc_node_lock(node);
+	link = node->links[bearer_id];
+	if (link) {
+		strncpy(linkname, link->name, len);
+		tipc_node_unlock(node);
+		return 0;
+	}
+	tipc_node_unlock(node);
+	return -EINVAL;
+}

net/tipc/node.h

@@ -118,6 +118,7 @@ int tipc_node_active_links(struct tipc_node *n_ptr);
 int tipc_node_is_up(struct tipc_node *n_ptr);
 struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space);
 struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space);
+int tipc_node_get_linkname(u32 bearer_id, u32 node, char *linkname, size_t len);
 
 static inline void tipc_node_lock(struct tipc_node *n_ptr)
 {

net/tipc/socket.c

@@ -36,6 +36,7 @@
 
 #include "core.h"
 #include "port.h"
+#include "node.h"
 
 #include <linux/export.h>
 
@@ -1905,6 +1906,28 @@ static int tipc_getsockopt(struct socket *sock, int lvl, int opt,
 	return put_user(sizeof(value), ol);
 }
 
+int tipc_ioctl(struct socket *sk, unsigned int cmd, unsigned long arg)
+{
+	struct tipc_sioc_ln_req lnr;
+	void __user *argp = (void __user *)arg;
+
+	switch (cmd) {
+	case SIOCGETLINKNAME:
+		if (copy_from_user(&lnr, argp, sizeof(lnr)))
+			return -EFAULT;
+		if (!tipc_node_get_linkname(lnr.bearer_id, lnr.peer,
+					    lnr.linkname, TIPC_MAX_LINK_NAME)) {
+			if (copy_to_user(argp, &lnr, sizeof(lnr)))
+				return -EFAULT;
+			return 0;
+		}
+		return -EADDRNOTAVAIL;
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	}
+}
+
 /* Protocol switches for the various types of TIPC sockets */
 
 static const struct proto_ops msg_ops = {
@@ -1917,7 +1940,7 @@ static const struct proto_ops msg_ops = {
 	.accept		= sock_no_accept,
 	.getname	= tipc_getname,
 	.poll		= tipc_poll,
-	.ioctl		= sock_no_ioctl,
+	.ioctl		= tipc_ioctl,
 	.listen		= sock_no_listen,
 	.shutdown	= tipc_shutdown,
 	.setsockopt	= tipc_setsockopt,
@@ -1938,7 +1961,7 @@ static const struct proto_ops packet_ops = {
 	.accept		= tipc_accept,
 	.getname	= tipc_getname,
 	.poll		= tipc_poll,
-	.ioctl		= sock_no_ioctl,
+	.ioctl		= tipc_ioctl,
 	.listen		= tipc_listen,
 	.shutdown	= tipc_shutdown,
 	.setsockopt	= tipc_setsockopt,
@@ -1959,7 +1982,7 @@ static const struct proto_ops stream_ops = {
 	.accept		= tipc_accept,
 	.getname	= tipc_getname,
 	.poll		= tipc_poll,
-	.ioctl		= sock_no_ioctl,
+	.ioctl		= tipc_ioctl,
 	.listen		= tipc_listen,
 	.shutdown	= tipc_shutdown,
 	.setsockopt	= tipc_setsockopt,