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authorPeter Krystad <peter.krystad@linux.intel.com>2020-01-21 16:56:19 -0800
committerDavid S. Miller <davem@davemloft.net>2020-01-24 13:44:07 +0100
commitcf7da0d66cc1a2a19fc5930bb746ffbb2d4cd1be (patch)
tree2dfa99e276763d94d9e28c54e663343ab6f1388a /net/mptcp
parentcec37a6e41aae7bf3df9a3da783380a4d9325fd8 (diff)
mptcp: Create SUBFLOW socket for incoming connections
Add subflow_request_sock type that extends tcp_request_sock and add an is_mptcp flag to tcp_request_sock distinguish them. Override the listen() and accept() methods of the MPTCP socket proto_ops so they may act on the subflow socket. Override the conn_request() and syn_recv_sock() handlers in the inet_connection_sock to handle incoming MPTCP SYNs and the ACK to the response SYN. Add handling in tcp_output.c to add MP_CAPABLE to an outgoing SYN-ACK response for a subflow_request_sock. Co-developed-by: Davide Caratti <dcaratti@redhat.com> Signed-off-by: Davide Caratti <dcaratti@redhat.com> Co-developed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Florian Westphal <fw@strlen.de> Co-developed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Co-developed-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Peter Krystad <peter.krystad@linux.intel.com> Signed-off-by: Christoph Paasch <cpaasch@apple.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp')
-rw-r--r--net/mptcp/protocol.c236
1 files changed, 231 insertions, 5 deletions
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index bdd58da1e4f6..e08a25eabcd5 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -14,6 +14,9 @@
#include <net/inet_hashtables.h>
#include <net/protocol.h>
#include <net/tcp.h>
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+#include <net/transp_v6.h>
+#endif
#include <net/mptcp.h>
#include "protocol.h"
@@ -212,6 +215,90 @@ static void mptcp_close(struct sock *sk, long timeout)
sk_common_release(sk);
}
+static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk)
+{
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+ const struct ipv6_pinfo *ssk6 = inet6_sk(ssk);
+ struct ipv6_pinfo *msk6 = inet6_sk(msk);
+
+ msk->sk_v6_daddr = ssk->sk_v6_daddr;
+ msk->sk_v6_rcv_saddr = ssk->sk_v6_rcv_saddr;
+
+ if (msk6 && ssk6) {
+ msk6->saddr = ssk6->saddr;
+ msk6->flow_label = ssk6->flow_label;
+ }
+#endif
+
+ inet_sk(msk)->inet_num = inet_sk(ssk)->inet_num;
+ inet_sk(msk)->inet_dport = inet_sk(ssk)->inet_dport;
+ inet_sk(msk)->inet_sport = inet_sk(ssk)->inet_sport;
+ inet_sk(msk)->inet_daddr = inet_sk(ssk)->inet_daddr;
+ inet_sk(msk)->inet_saddr = inet_sk(ssk)->inet_saddr;
+ inet_sk(msk)->inet_rcv_saddr = inet_sk(ssk)->inet_rcv_saddr;
+}
+
+static struct sock *mptcp_accept(struct sock *sk, int flags, int *err,
+ bool kern)
+{
+ struct mptcp_sock *msk = mptcp_sk(sk);
+ struct socket *listener;
+ struct sock *newsk;
+
+ listener = __mptcp_nmpc_socket(msk);
+ if (WARN_ON_ONCE(!listener)) {
+ *err = -EINVAL;
+ return NULL;
+ }
+
+ pr_debug("msk=%p, listener=%p", msk, mptcp_subflow_ctx(listener->sk));
+ newsk = inet_csk_accept(listener->sk, flags, err, kern);
+ if (!newsk)
+ return NULL;
+
+ pr_debug("msk=%p, subflow is mptcp=%d", msk, sk_is_mptcp(newsk));
+
+ if (sk_is_mptcp(newsk)) {
+ struct mptcp_subflow_context *subflow;
+ struct sock *new_mptcp_sock;
+ struct sock *ssk = newsk;
+
+ subflow = mptcp_subflow_ctx(newsk);
+ lock_sock(sk);
+
+ local_bh_disable();
+ new_mptcp_sock = sk_clone_lock(sk, GFP_ATOMIC);
+ if (!new_mptcp_sock) {
+ *err = -ENOBUFS;
+ local_bh_enable();
+ release_sock(sk);
+ tcp_close(newsk, 0);
+ return NULL;
+ }
+
+ mptcp_init_sock(new_mptcp_sock);
+
+ msk = mptcp_sk(new_mptcp_sock);
+ msk->remote_key = subflow->remote_key;
+ msk->local_key = subflow->local_key;
+ msk->subflow = NULL;
+
+ newsk = new_mptcp_sock;
+ mptcp_copy_inaddrs(newsk, ssk);
+ list_add(&subflow->node, &msk->conn_list);
+
+ /* will be fully established at mptcp_stream_accept()
+ * completion.
+ */
+ inet_sk_state_store(new_mptcp_sock, TCP_SYN_RECV);
+ bh_unlock_sock(new_mptcp_sock);
+ local_bh_enable();
+ release_sock(sk);
+ }
+
+ return newsk;
+}
+
static int mptcp_get_port(struct sock *sk, unsigned short snum)
{
struct mptcp_sock *msk = mptcp_sk(sk);
@@ -246,12 +333,21 @@ void mptcp_finish_connect(struct sock *ssk)
WRITE_ONCE(msk->local_key, subflow->local_key);
}
+static void mptcp_sock_graft(struct sock *sk, struct socket *parent)
+{
+ write_lock_bh(&sk->sk_callback_lock);
+ rcu_assign_pointer(sk->sk_wq, &parent->wq);
+ sk_set_socket(sk, parent);
+ sk->sk_uid = SOCK_INODE(parent)->i_uid;
+ write_unlock_bh(&sk->sk_callback_lock);
+}
+
static struct proto mptcp_prot = {
.name = "MPTCP",
.owner = THIS_MODULE,
.init = mptcp_init_sock,
.close = mptcp_close,
- .accept = inet_csk_accept,
+ .accept = mptcp_accept,
.shutdown = tcp_shutdown,
.sendmsg = mptcp_sendmsg,
.recvmsg = mptcp_recvmsg,
@@ -266,10 +362,7 @@ static int mptcp_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
struct mptcp_sock *msk = mptcp_sk(sock->sk);
struct socket *ssock;
- int err = -ENOTSUPP;
-
- if (uaddr->sa_family != AF_INET) // @@ allow only IPv4 for now
- return err;
+ int err;
lock_sock(sock->sk);
ssock = __mptcp_socket_create(msk, MPTCP_SAME_STATE);
@@ -279,6 +372,8 @@ static int mptcp_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
}
err = ssock->ops->bind(ssock, uaddr, addr_len);
+ if (!err)
+ mptcp_copy_inaddrs(sock->sk, ssock->sk);
unlock:
release_sock(sock->sk);
@@ -299,14 +394,139 @@ static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr,
goto unlock;
}
+#ifdef CONFIG_TCP_MD5SIG
+ /* no MPTCP if MD5SIG is enabled on this socket or we may run out of
+ * TCP option space.
+ */
+ if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info))
+ mptcp_subflow_ctx(ssock->sk)->request_mptcp = 0;
+#endif
+
err = ssock->ops->connect(ssock, uaddr, addr_len, flags);
inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk));
+ mptcp_copy_inaddrs(sock->sk, ssock->sk);
unlock:
release_sock(sock->sk);
return err;
}
+static int mptcp_v4_getname(struct socket *sock, struct sockaddr *uaddr,
+ int peer)
+{
+ if (sock->sk->sk_prot == &tcp_prot) {
+ /* we are being invoked from __sys_accept4, after
+ * mptcp_accept() has just accepted a non-mp-capable
+ * flow: sk is a tcp_sk, not an mptcp one.
+ *
+ * Hand the socket over to tcp so all further socket ops
+ * bypass mptcp.
+ */
+ sock->ops = &inet_stream_ops;
+ }
+
+ return inet_getname(sock, uaddr, peer);
+}
+
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+static int mptcp_v6_getname(struct socket *sock, struct sockaddr *uaddr,
+ int peer)
+{
+ if (sock->sk->sk_prot == &tcpv6_prot) {
+ /* we are being invoked from __sys_accept4 after
+ * mptcp_accept() has accepted a non-mp-capable
+ * subflow: sk is a tcp_sk, not mptcp.
+ *
+ * Hand the socket over to tcp so all further
+ * socket ops bypass mptcp.
+ */
+ sock->ops = &inet6_stream_ops;
+ }
+
+ return inet6_getname(sock, uaddr, peer);
+}
+#endif
+
+static int mptcp_listen(struct socket *sock, int backlog)
+{
+ struct mptcp_sock *msk = mptcp_sk(sock->sk);
+ struct socket *ssock;
+ int err;
+
+ pr_debug("msk=%p", msk);
+
+ lock_sock(sock->sk);
+ ssock = __mptcp_socket_create(msk, TCP_LISTEN);
+ if (IS_ERR(ssock)) {
+ err = PTR_ERR(ssock);
+ goto unlock;
+ }
+
+ err = ssock->ops->listen(ssock, backlog);
+ inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk));
+ if (!err)
+ mptcp_copy_inaddrs(sock->sk, ssock->sk);
+
+unlock:
+ release_sock(sock->sk);
+ return err;
+}
+
+static bool is_tcp_proto(const struct proto *p)
+{
+#if IS_ENABLED(CONFIG_MPTCP_IPV6)
+ return p == &tcp_prot || p == &tcpv6_prot;
+#else
+ return p == &tcp_prot;
+#endif
+}
+
+static int mptcp_stream_accept(struct socket *sock, struct socket *newsock,
+ int flags, bool kern)
+{
+ struct mptcp_sock *msk = mptcp_sk(sock->sk);
+ struct socket *ssock;
+ int err;
+
+ pr_debug("msk=%p", msk);
+
+ lock_sock(sock->sk);
+ if (sock->sk->sk_state != TCP_LISTEN)
+ goto unlock_fail;
+
+ ssock = __mptcp_nmpc_socket(msk);
+ if (!ssock)
+ goto unlock_fail;
+
+ sock_hold(ssock->sk);
+ release_sock(sock->sk);
+
+ err = ssock->ops->accept(sock, newsock, flags, kern);
+ if (err == 0 && !is_tcp_proto(newsock->sk->sk_prot)) {
+ struct mptcp_sock *msk = mptcp_sk(newsock->sk);
+ struct mptcp_subflow_context *subflow;
+
+ /* set ssk->sk_socket of accept()ed flows to mptcp socket.
+ * This is needed so NOSPACE flag can be set from tcp stack.
+ */
+ list_for_each_entry(subflow, &msk->conn_list, node) {
+ struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
+
+ if (!ssk->sk_socket)
+ mptcp_sock_graft(ssk, newsock);
+ }
+
+ inet_sk_state_store(newsock->sk, TCP_ESTABLISHED);
+ }
+
+ sock_put(ssock->sk);
+ return err;
+
+unlock_fail:
+ release_sock(sock->sk);
+ return -EINVAL;
+}
+
static __poll_t mptcp_poll(struct file *file, struct socket *sock,
struct poll_table_struct *wait)
{
@@ -332,6 +552,9 @@ void __init mptcp_init(void)
mptcp_stream_ops.bind = mptcp_bind;
mptcp_stream_ops.connect = mptcp_stream_connect;
mptcp_stream_ops.poll = mptcp_poll;
+ mptcp_stream_ops.accept = mptcp_stream_accept;
+ mptcp_stream_ops.getname = mptcp_v4_getname;
+ mptcp_stream_ops.listen = mptcp_listen;
mptcp_subflow_init();
@@ -371,6 +594,9 @@ int mptcpv6_init(void)
mptcp_v6_stream_ops.bind = mptcp_bind;
mptcp_v6_stream_ops.connect = mptcp_stream_connect;
mptcp_v6_stream_ops.poll = mptcp_poll;
+ mptcp_v6_stream_ops.accept = mptcp_stream_accept;
+ mptcp_v6_stream_ops.getname = mptcp_v6_getname;
+ mptcp_v6_stream_ops.listen = mptcp_listen;
err = inet6_register_protosw(&mptcp_v6_protosw);
if (err)