Commit da263fcb authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'mptcp-userspace-pm-create-sockets-for-the-right-family' 

Matthieu Baerts says:

====================
mptcp: userspace pm: create sockets for the right family

Before these patches, the Userspace Path Manager would allow the
creation of subflows with wrong families: taking the one of the MPTCP
socket instead of the provided ones and resulting in the creation of
subflows with likely not the right source and/or destination IPs. It
would also allow the creation of subflows between different families or
not respecting v4/v6-only socket attributes.

Patch 1 lets the userspace PM select the proper family to avoid creating
subflows with the wrong source and/or destination addresses because the
family is not the expected one.

Patch 2 makes sure the userspace PM doesn't allow the userspace to
create subflows for a family that is not allowed.

Patch 3 validates scenarios with a mix of v4 and v6 subflows for the
same MPTCP connection.

These patches fix issues introduced in v5.19 when the userspace path
manager has been introduced.
====================

Link: https://lore.kernel.org/r/20230112-upstream-net-20230112-netlink-v4-v6-v1-0-6a8363a221d2@tessares.net


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 925f3deb 4656d72c

net/mptcp/pm.c

+25 −0
Original line number Diff line number Diff line
@@ -420,6 +420,31 @@ void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk) 
	}

}



/* if sk is ipv4 or ipv6_only allows only same-family local and remote addresses,

 * otherwise allow any matching local/remote pair

 */

bool mptcp_pm_addr_families_match(const struct sock *sk,

				  const struct mptcp_addr_info *loc,

				  const struct mptcp_addr_info *rem)

{

	bool mptcp_is_v4 = sk->sk_family == AF_INET;



#if IS_ENABLED(CONFIG_MPTCP_IPV6)

	bool loc_is_v4 = loc->family == AF_INET || ipv6_addr_v4mapped(&loc->addr6);

	bool rem_is_v4 = rem->family == AF_INET || ipv6_addr_v4mapped(&rem->addr6);



	if (mptcp_is_v4)

		return loc_is_v4 && rem_is_v4;



	if (ipv6_only_sock(sk))

		return !loc_is_v4 && !rem_is_v4;



	return loc_is_v4 == rem_is_v4;

#else

	return mptcp_is_v4 && loc->family == AF_INET && rem->family == AF_INET;

#endif

}



void mptcp_pm_data_reset(struct mptcp_sock *msk)

{

	u8 pm_type = mptcp_get_pm_type(sock_net((struct sock *)msk));

net/mptcp/pm_userspace.c

+7 −0
Original line number Diff line number Diff line
@@ -294,6 +294,13 @@ int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info) 
	}



	sk = (struct sock *)msk;



	if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {

		GENL_SET_ERR_MSG(info, "families mismatch");

		err = -EINVAL;

		goto create_err;

	}



	lock_sock(sk);



	err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);

net/mptcp/protocol.c

+1 −1
Original line number Diff line number Diff line
@@ -98,7 +98,7 @@ static int __mptcp_socket_create(struct mptcp_sock *msk) 
	struct socket *ssock;

	int err;



	err = mptcp_subflow_create_socket(sk, &ssock);

	err = mptcp_subflow_create_socket(sk, sk->sk_family, &ssock);

	if (err)

		return err;

net/mptcp/protocol.h

+5 −1
Original line number Diff line number Diff line
@@ -641,7 +641,8 @@ bool mptcp_addresses_equal(const struct mptcp_addr_info *a, 
/* called with sk socket lock held */

int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc,

			    const struct mptcp_addr_info *remote);

int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock);

int mptcp_subflow_create_socket(struct sock *sk, unsigned short family,

				struct socket **new_sock);

void mptcp_info2sockaddr(const struct mptcp_addr_info *info,

			 struct sockaddr_storage *addr,

			 unsigned short family);
@@ -776,6 +777,9 @@ int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info, 
int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,

			 bool require_family,

			 struct mptcp_pm_addr_entry *entry);

bool mptcp_pm_addr_families_match(const struct sock *sk,

				  const struct mptcp_addr_info *loc,

				  const struct mptcp_addr_info *rem);

void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);

void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk);

void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side);

net/mptcp/subflow.c

+5 −4
Original line number Diff line number Diff line
@@ -1547,7 +1547,7 @@ int __mptcp_subflow_connect(struct sock *sk, const struct mptcp_addr_info *loc, 
	if (!mptcp_is_fully_established(sk))

		goto err_out;



	err = mptcp_subflow_create_socket(sk, &sf);

	err = mptcp_subflow_create_socket(sk, loc->family, &sf);

	if (err)

		goto err_out;
@@ -1660,7 +1660,9 @@ static void mptcp_subflow_ops_undo_override(struct sock *ssk) 
#endif

		ssk->sk_prot = &tcp_prot;

}

int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock)



int mptcp_subflow_create_socket(struct sock *sk, unsigned short family,

				struct socket **new_sock)

{

	struct mptcp_subflow_context *subflow;

	struct net *net = sock_net(sk);
@@ -1673,8 +1675,7 @@ int mptcp_subflow_create_socket(struct sock *sk, struct socket **new_sock) 
	if (unlikely(!sk->sk_socket))

		return -EINVAL;



	err = sock_create_kern(net, sk->sk_family, SOCK_STREAM, IPPROTO_TCP,

			       &sf);

	err = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP, &sf);

	if (err)

		return err;