tipc: add sock dump to new netlink api

Add TIPC_NL_SOCK_GET command to the new tipc netlink API.

This command supports dumping of all available sockets with their
associated connection or publication(s). It could be extended to reply
with a single socket if the NLM_F_DUMP isn't set.

The information about a socket includes reference, address, connection
information / publication information.

Netlink logical layout of response message:
-> socket
    -> reference
    -> address
    [
    -> connection
        -> node
        -> socket
        [
        -> connected flag
        -> type
        -> instance
        ]
    ]
    [
    -> publication flag
    ]
Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/tipc_netlink.h

@@ -45,6 +45,7 @@ enum {
 	TIPC_NL_BEARER_ENABLE,
 	TIPC_NL_BEARER_GET,
 	TIPC_NL_BEARER_SET,
+	TIPC_NL_SOCK_GET,
 
 	__TIPC_NL_CMD_MAX,
 	TIPC_NL_CMD_MAX = __TIPC_NL_CMD_MAX - 1
@@ -54,6 +55,7 @@ enum {
 enum {
 	TIPC_NLA_UNSPEC,
 	TIPC_NLA_BEARER,		/* nest */
+	TIPC_NLA_SOCK,			/* nest */
 
 	__TIPC_NLA_MAX,
 	TIPC_NLA_MAX = __TIPC_NLA_MAX - 1
@@ -70,6 +72,32 @@ enum {
 	TIPC_NLA_BEARER_MAX = __TIPC_NLA_BEARER_MAX - 1
 };
 
+/* Socket info */
+enum {
+	TIPC_NLA_SOCK_UNSPEC,
+	TIPC_NLA_SOCK_ADDR,		/* u32 */
+	TIPC_NLA_SOCK_REF,		/* u32 */
+	TIPC_NLA_SOCK_CON,		/* nest */
+	TIPC_NLA_SOCK_HAS_PUBL,		/* flag */
+
+	__TIPC_NLA_SOCK_MAX,
+	TIPC_NLA_SOCK_MAX = __TIPC_NLA_SOCK_MAX - 1
+};
+
+/* Nest, connection info */
+enum {
+	TIPC_NLA_CON_UNSPEC,
+
+	TIPC_NLA_CON_FLAG,		/* flag */
+	TIPC_NLA_CON_NODE,		/* u32 */
+	TIPC_NLA_CON_SOCK,		/* u32 */
+	TIPC_NLA_CON_TYPE,		/* u32 */
+	TIPC_NLA_CON_INST,		/* u32 */
+
+	__TIPC_NLA_CON_MAX,
+	TIPC_NLA_CON_MAX = __TIPC_NLA_CON_MAX - 1
+};
+
 /* Nest, link propreties. Valid for link, media and bearer */
 enum {
 	TIPC_NLA_PROP_UNSPEC,

net/tipc/netlink.c

@@ -36,6 +36,7 @@
 
 #include "core.h"
 #include "config.h"
+#include "socket.h"
 #include "bearer.h"
 #include <net/genetlink.h>
 
@@ -72,6 +73,7 @@ static int handle_cmd(struct sk_buff *skb, struct genl_info *info)
 static const struct nla_policy tipc_nl_policy[TIPC_NLA_MAX + 1] = {
 	[TIPC_NLA_UNSPEC]	= { .type = NLA_UNSPEC, },
 	[TIPC_NLA_BEARER]	= { .type = NLA_NESTED, },
+	[TIPC_NLA_SOCK]		= { .type = NLA_NESTED, },
 };
 
 /* Legacy ASCII API */
@@ -123,6 +125,11 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
 		.cmd	= TIPC_NL_BEARER_SET,
 		.doit	= tipc_nl_bearer_set,
 		.policy = tipc_nl_policy,
+	},
+	{
+		.cmd	= TIPC_NL_SOCK_GET,
+		.dumpit	= tipc_nl_sk_dump,
+		.policy = tipc_nl_policy,
 	}
 };
 

net/tipc/socket.c

@@ -2801,3 +2801,104 @@ void tipc_socket_stop(void)
 	sock_unregister(tipc_family_ops.family);
 	proto_unregister(&tipc_proto);
 }
+
+/* Caller should hold socket lock for the passed tipc socket. */
+int __tipc_nl_add_sk_con(struct sk_buff *skb, struct tipc_sock *tsk)
+{
+	u32 peer_node;
+	u32 peer_port;
+	struct nlattr *nest;
+
+	peer_node = tsk_peer_node(tsk);
+	peer_port = tsk_peer_port(tsk);
+
+	nest = nla_nest_start(skb, TIPC_NLA_SOCK_CON);
+
+	if (nla_put_u32(skb, TIPC_NLA_CON_NODE, peer_node))
+		goto msg_full;
+	if (nla_put_u32(skb, TIPC_NLA_CON_SOCK, peer_port))
+		goto msg_full;
+
+	if (tsk->conn_type != 0) {
+		if (nla_put_flag(skb, TIPC_NLA_CON_FLAG))
+			goto msg_full;
+		if (nla_put_u32(skb, TIPC_NLA_CON_TYPE, tsk->conn_type))
+			goto msg_full;
+		if (nla_put_u32(skb, TIPC_NLA_CON_INST, tsk->conn_instance))
+			goto msg_full;
+	}
+	nla_nest_end(skb, nest);
+
+	return 0;
+
+msg_full:
+	nla_nest_cancel(skb, nest);
+
+	return -EMSGSIZE;
+}
+
+/* Caller should hold socket lock for the passed tipc socket. */
+int __tipc_nl_add_sk(struct sk_buff *skb, struct netlink_callback *cb,
+		     struct tipc_sock *tsk)
+{
+	int err;
+	void *hdr;
+	struct nlattr *attrs;
+
+	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+			  &tipc_genl_v2_family, NLM_F_MULTI, TIPC_NL_SOCK_GET);
+	if (!hdr)
+		goto msg_cancel;
+
+	attrs = nla_nest_start(skb, TIPC_NLA_SOCK);
+	if (!attrs)
+		goto genlmsg_cancel;
+	if (nla_put_u32(skb, TIPC_NLA_SOCK_REF, tsk->ref))
+		goto attr_msg_cancel;
+	if (nla_put_u32(skb, TIPC_NLA_SOCK_ADDR, tipc_own_addr))
+		goto attr_msg_cancel;
+
+	if (tsk->connected) {
+		err = __tipc_nl_add_sk_con(skb, tsk);
+		if (err)
+			goto attr_msg_cancel;
+	} else if (!list_empty(&tsk->publications)) {
+		if (nla_put_flag(skb, TIPC_NLA_SOCK_HAS_PUBL))
+			goto attr_msg_cancel;
+	}
+	nla_nest_end(skb, attrs);
+	genlmsg_end(skb, hdr);
+
+	return 0;
+
+attr_msg_cancel:
+	nla_nest_cancel(skb, attrs);
+genlmsg_cancel:
+	genlmsg_cancel(skb, hdr);
+msg_cancel:
+	return -EMSGSIZE;
+}
+
+int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int err;
+	struct tipc_sock *tsk;
+	u32 prev_ref = cb->args[0];
+	u32 ref = prev_ref;
+
+	tsk = tipc_sk_get_next(&ref);
+	for (; tsk; tsk = tipc_sk_get_next(&ref)) {
+		lock_sock(&tsk->sk);
+		err = __tipc_nl_add_sk(skb, cb, tsk);
+		release_sock(&tsk->sk);
+		tipc_sk_put(tsk);
+		if (err)
+			break;
+
+		prev_ref = ref;
+	}
+
+	cb->args[0] = prev_ref;
+
+	return skb->len;
+}

net/tipc/socket.h

@@ -36,6 +36,7 @@
 #define _TIPC_SOCK_H
 
 #include <net/sock.h>
+#include <net/genetlink.h>
 
 #define TIPC_CONNACK_INTV         256
 #define TIPC_FLOWCTRL_WIN        (TIPC_CONNACK_INTV * 2)
@@ -47,5 +48,6 @@ void tipc_sk_mcast_rcv(struct sk_buff *buf);
 void tipc_sk_reinit(void);
 int tipc_sk_ref_table_init(u32 requested_size, u32 start);
 void tipc_sk_ref_table_stop(void);
+int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb);
 
 #endif