tipc: add publication dump to new netlink api

Add TIPC_NL_PUBL_GET command to the new tipc netlink API.

This command supports dumping of all publications for a specific
socket.

Netlink logical layout of request message:
    -> socket
        -> reference

Netlink logical layout of response message:
    -> publication
        -> type
        -> lower
        -> upper

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>

4 files changed, 154 insertions, 0 deletions

diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index 951fabeec8b7..9bc64aaff466 100644
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -74,6 +74,7 @@ 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, },
+	[TIPC_NLA_PUBL]		= { .type = NLA_NESTED, }
 };
 
 /* Legacy ASCII API */
@@ -130,9 +131,25 @@ static const struct genl_ops tipc_genl_v2_ops[] = {
 		.cmd	= TIPC_NL_SOCK_GET,
 		.dumpit	= tipc_nl_sk_dump,
 		.policy = tipc_nl_policy,
+	},
+	{
+		.cmd	= TIPC_NL_PUBL_GET,
+		.dumpit	= tipc_nl_publ_dump,
+		.policy = tipc_nl_policy,
 	}
 };
 
+int tipc_nlmsg_parse(const struct nlmsghdr *nlh, struct nlattr ***attr)
+{
+	u32 maxattr = tipc_genl_v2_family.maxattr;
+
+	*attr = tipc_genl_v2_family.attrbuf;
+	if (!*attr)
+		return -EOPNOTSUPP;
+
+	return nlmsg_parse(nlh, GENL_HDRLEN, *attr, maxattr, tipc_nl_policy);
+}
+
 int tipc_netlink_start(void)
 {
 	int res;
diff --git a/net/tipc/netlink.h b/net/tipc/netlink.h
index e34a3fca7d3d..1425c6869de0 100644
--- a/net/tipc/netlink.h
+++ b/net/tipc/netlink.h
@@ -37,6 +37,7 @@
 #define _TIPC_NETLINK_H
 
 extern struct genl_family tipc_genl_v2_family;
+int tipc_nlmsg_parse(const struct nlmsghdr *nlh, struct nlattr ***buf);
 
 struct tipc_nl_msg {
 	struct sk_buff *skb;
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 9e95c1ea5564..e91809182c28 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -121,6 +121,14 @@ static const struct proto_ops msg_ops;
 static struct proto tipc_proto;
 static struct proto tipc_proto_kern;
 
+static const struct nla_policy tipc_nl_sock_policy[TIPC_NLA_SOCK_MAX + 1] = {
+	[TIPC_NLA_SOCK_UNSPEC]		= { .type = NLA_UNSPEC },
+	[TIPC_NLA_SOCK_ADDR]		= { .type = NLA_U32 },
+	[TIPC_NLA_SOCK_REF]		= { .type = NLA_U32 },
+	[TIPC_NLA_SOCK_CON]		= { .type = NLA_NESTED },
+	[TIPC_NLA_SOCK_HAS_PUBL]	= { .type = NLA_FLAG }
+};
+
 /*
  * Revised TIPC socket locking policy:
  *
@@ -2902,3 +2910,130 @@ int tipc_nl_sk_dump(struct sk_buff *skb, struct netlink_callback *cb)
 
 	return skb->len;
 }
+
+/* Caller should hold socket lock for the passed tipc socket. */
+int __tipc_nl_add_sk_publ(struct sk_buff *skb, struct netlink_callback *cb,
+			  struct publication *publ)
+{
+	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_PUBL_GET);
+	if (!hdr)
+		goto msg_cancel;
+
+	attrs = nla_nest_start(skb, TIPC_NLA_PUBL);
+	if (!attrs)
+		goto genlmsg_cancel;
+
+	if (nla_put_u32(skb, TIPC_NLA_PUBL_KEY, publ->key))
+		goto attr_msg_cancel;
+	if (nla_put_u32(skb, TIPC_NLA_PUBL_TYPE, publ->type))
+		goto attr_msg_cancel;
+	if (nla_put_u32(skb, TIPC_NLA_PUBL_LOWER, publ->lower))
+		goto attr_msg_cancel;
+	if (nla_put_u32(skb, TIPC_NLA_PUBL_UPPER, publ->upper))
+		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;
+}
+
+/* Caller should hold socket lock for the passed tipc socket. */
+int __tipc_nl_list_sk_publ(struct sk_buff *skb, struct netlink_callback *cb,
+			   struct tipc_sock *tsk, u32 *last_publ)
+{
+	int err;
+	struct publication *p;
+
+	if (*last_publ) {
+		list_for_each_entry(p, &tsk->publications, pport_list) {
+			if (p->key == *last_publ)
+				break;
+		}
+		if (p->key != *last_publ) {
+			/* 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;
+			*last_publ = 0;
+			return -EPIPE;
+		}
+	} else {
+		p = list_first_entry(&tsk->publications, struct publication,
+				     pport_list);
+	}
+
+	list_for_each_entry_from(p, &tsk->publications, pport_list) {
+		err = __tipc_nl_add_sk_publ(skb, cb, p);
+		if (err) {
+			*last_publ = p->key;
+			return err;
+		}
+	}
+	*last_publ = 0;
+
+	return 0;
+}
+
+int tipc_nl_publ_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int err;
+	u32 tsk_ref = cb->args[0];
+	u32 last_publ = cb->args[1];
+	u32 done = cb->args[2];
+	struct tipc_sock *tsk;
+
+	if (!tsk_ref) {
+		struct nlattr **attrs;
+		struct nlattr *sock[TIPC_NLA_SOCK_MAX + 1];
+
+		err = tipc_nlmsg_parse(cb->nlh, &attrs);
+		if (err)
+			return err;
+
+		err = nla_parse_nested(sock, TIPC_NLA_SOCK_MAX,
+				       attrs[TIPC_NLA_SOCK],
+				       tipc_nl_sock_policy);
+		if (err)
+			return err;
+
+		if (!sock[TIPC_NLA_SOCK_REF])
+			return -EINVAL;
+
+		tsk_ref = nla_get_u32(sock[TIPC_NLA_SOCK_REF]);
+	}
+
+	if (done)
+		return 0;
+
+	tsk = tipc_sk_get(tsk_ref);
+	if (!tsk)
+		return -EINVAL;
+
+	lock_sock(&tsk->sk);
+	err = __tipc_nl_list_sk_publ(skb, cb, tsk, &last_publ);
+	if (!err)
+		done = 1;
+	release_sock(&tsk->sk);
+	tipc_sk_put(tsk);
+
+	cb->args[0] = tsk_ref;
+	cb->args[1] = last_publ;
+	cb->args[2] = done;
+
+	return skb->len;
+}
diff --git a/net/tipc/socket.h b/net/tipc/socket.h
index 16dfd62983a8..d34089387006 100644
--- a/net/tipc/socket.h
+++ b/net/tipc/socket.h
@@ -49,5 +49,6 @@ 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);
+int tipc_nl_publ_dump(struct sk_buff *skb, struct netlink_callback *cb);
 
 #endif