summaryrefslogtreecommitdiff
path: root/net
diff options
context:
space:
mode:
authorPaolo Abeni <pabeni@redhat.com>2023-01-12 18:42:51 +0100
committerJakub Kicinski <kuba@kernel.org>2023-01-13 21:55:45 -0800
commit6bc1fe7dd748ba5e76e7917d110837cafe7b931c (patch)
tree5e6542f7cde71b7a0f6e3af4159e57b93076ea2b /net
parent925f3deb45df73173a33e1e81db77575f4ffde39 (diff)
mptcp: explicitly specify sock family at subflow creation time
Let the caller specify the to-be-created subflow family. For a given MPTCP socket created with the AF_INET6 family, the current userspace PM can already ask the kernel to create subflows in v4 and v6. If "plain" IPv4 addresses are passed to the kernel, they are automatically mapped in v6 addresses "by accident". This can be problematic because the userspace will need to pass different addresses, now the v4-mapped-v6 addresses to destroy this new subflow. On the other hand, if the MPTCP socket has been created with the AF_INET family, the command to create a subflow in v6 will be accepted but the result will not be the one as expected as new subflow will be created in IPv4 using part of the v6 addresses passed to the kernel: not creating the expected subflow then. No functional change intended for the in-kernel PM where an explicit enforcement is currently in place. This arbitrary enforcement will be leveraged by other patches in a future version. Fixes: 702c2f646d42 ("mptcp: netlink: allow userspace-driven subflow establishment") Cc: stable@vger.kernel.org Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
-rw-r--r--net/mptcp/protocol.c2
-rw-r--r--net/mptcp/protocol.h3
-rw-r--r--net/mptcp/subflow.c9
3 files changed, 8 insertions, 6 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index b7ad030dfe89..8cd6cc67c2c5 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -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;
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index a0d1658ce59e..a9e0355744b6 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -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);
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index bd387d4b5a38..ec54413fb31f 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -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;