mptcp: netlink: Add MPTCP_PM_CMD_REMOVE

This change adds a MPTCP netlink command for issuing a
REMOVE_ADDR signal for an address over the chosen MPTCP
connection from a userspace path manager.

The command requires the following parameters: {token, loc_id}.

Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 62 insertions, 0 deletions

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index 347184a9157b..3a42c9e66126 100644
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -180,3 +180,65 @@ int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info)
 	sock_put((struct sock *)msk);
 	return err;
 }
+
+int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)
+{
+	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
+	struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
+	struct mptcp_pm_addr_entry *match = NULL;
+	struct mptcp_pm_addr_entry *entry;
+	struct mptcp_sock *msk;
+	LIST_HEAD(free_list);
+	int err = -EINVAL;
+	u32 token_val;
+	u8 id_val;
+
+	if (!id || !token) {
+		GENL_SET_ERR_MSG(info, "missing required inputs");
+		return err;
+	}
+
+	id_val = nla_get_u8(id);
+	token_val = nla_get_u32(token);
+
+	msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
+	if (!msk) {
+		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
+		return err;
+	}
+
+	if (!mptcp_pm_is_userspace(msk)) {
+		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
+		goto remove_err;
+	}
+
+	lock_sock((struct sock *)msk);
+
+	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
+		if (entry->addr.id == id_val) {
+			match = entry;
+			break;
+		}
+	}
+
+	if (!match) {
+		GENL_SET_ERR_MSG(info, "address with specified id not found");
+		release_sock((struct sock *)msk);
+		goto remove_err;
+	}
+
+	list_move(&match->list, &free_list);
+
+	mptcp_pm_remove_addrs_and_subflows(msk, &free_list);
+
+	release_sock((struct sock *)msk);
+
+	list_for_each_entry_safe(match, entry, &free_list, list) {
+		sock_kfree_s((struct sock *)msk, match, sizeof(*match));
+	}
+
+	err = 0;
+ remove_err:
+	sock_put((struct sock *)msk);
+	return err;
+}