diff mbox series

[mptcp-next,v6,2/5] mptcp: pm nl: support IPv4 mapped in v6 addresses

Message ID 20210114172926.2563610-3-matthieu.baerts@tessares.net
State Accepted, archived
Commit eabdb734a318dfb9d0e836d22274a2df851eccc2
Delegated to: Matthieu Baerts
Headers show
Series add IPv4-mapped address support | expand

Commit Message

Matthieu Baerts Jan. 14, 2021, 5:29 p.m. UTC 
On one side, we can allow the creation of subflows between v4 mapped in
v6 and v4 addresses. For that we look for v4mapped addresses between the
local address we want to select and the remote one.

On the other side, we also properly deal with received v4mapped
addresses, either announced ones or set via Netlink.

Fixes: 01cacb00b35c ("mptcp: add netlink-based PM")
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/122
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Co-developed-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
---

Notes:
    v4 -> v5:
    - select_local_address(): extract info from sk again instead of using
      remote
    - also add explicit braces in select_local_address to avoid confusions
    - move the declaration of 'remote' to reduce the scope and to do it only
      when needed.
    - add missing Mat' suggesting-by tag (sorry, I forgot that earlier)
    
    v5 -> v6:
    - move the declaration of 'remote' in a dedicated commit, see next patch
      (Geliang)

 net/mptcp/pm_netlink.c | 33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 9b1f6298bbdb..f0afff6ba015 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -60,15 +60,20 @@  static bool addresses_equal(const struct mptcp_addr_info *a,
 {
 	bool addr_equals = false;
 
-	if (a->family != b->family)
-		return false;
-
-	if (a->family == AF_INET)
-		addr_equals = a->addr.s_addr == b->addr.s_addr;
+	if (a->family == b->family) {
+		if (a->family == AF_INET)
+			addr_equals = a->addr.s_addr == b->addr.s_addr;
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
-	else
-		addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
+		else
+			addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
+	} else if (a->family == AF_INET) {
+		if (ipv6_addr_v4mapped(&b->addr6))
+			addr_equals = a->addr.s_addr == b->addr6.s6_addr32[3];
+	} else if (b->family == AF_INET) {
+		if (ipv6_addr_v4mapped(&a->addr6))
+			addr_equals = a->addr6.s6_addr32[3] == b->addr.s_addr;
 #endif
+	}
 
 	if (!addr_equals)
 		return false;
@@ -137,6 +142,7 @@  select_local_address(const struct pm_nl_pernet *pernet,
 		     struct mptcp_sock *msk)
 {
 	struct mptcp_pm_addr_entry *entry, *ret = NULL;
+	struct sock *sk = (struct sock *)msk;
 
 	rcu_read_lock();
 	__mptcp_flush_join_list(msk);
@@ -144,11 +150,20 @@  select_local_address(const struct pm_nl_pernet *pernet,
 		if (!(entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
 			continue;
 
+		if (entry->addr.family != sk->sk_family) {
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+			if ((entry->addr.family == AF_INET &&
+			     !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) ||
+			    (sk->sk_family == AF_INET &&
+			     !ipv6_addr_v4mapped(&entry->addr.addr6)))
+#endif
+				continue;
+		}
+
 		/* avoid any address already in use by subflows and
 		 * pending join
 		 */
-		if (entry->addr.family == ((struct sock *)msk)->sk_family &&
-		    !lookup_subflow_by_saddr(&msk->conn_list, &entry->addr)) {
+		if (!lookup_subflow_by_saddr(&msk->conn_list, &entry->addr)) {
 			ret = entry;
 			break;
 		}