Commit 2c9e7765 authored by Florian Westphal's avatar Florian Westphal Committed by Jakub Kicinski
Browse files

mptcp: add TCP_INQ cmsg support 

Support the TCP_INQ setsockopt.

This is a boolean that tells recvmsg path to include the remaining
in-sequence bytes in the cmsg data.

v2: do not use CB(skb)->offset, increment map_seq instead (Paolo Abeni)
v3: adjust CB(skb)->map_seq when taking skb from ofo queue (Paolo Abeni)

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/224


Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent c0e5e11a

net/mptcp/protocol.c

+35 −1
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ struct mptcp_skb_cb { 


enum {

	MPTCP_CMSG_TS = BIT(0),

	MPTCP_CMSG_INQ = BIT(1),

};



static struct percpu_counter mptcp_sockets_allocated ____cacheline_aligned_in_smp;
@@ -738,6 +739,7 @@ static bool __mptcp_ofo_queue(struct mptcp_sock *msk) 
				 MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq,

				 delta);

			MPTCP_SKB_CB(skb)->offset += delta;

			MPTCP_SKB_CB(skb)->map_seq += delta;

			__skb_queue_tail(&sk->sk_receive_queue, skb);

		}

		msk->ack_seq = end_seq;
@@ -1784,8 +1786,10 @@ static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, 
		copied += count;



		if (count < data_len) {

			if (!(flags & MSG_PEEK))

			if (!(flags & MSG_PEEK)) {

				MPTCP_SKB_CB(skb)->offset += count;

				MPTCP_SKB_CB(skb)->map_seq += count;

			}

			break;

		}
@@ -1965,6 +1969,27 @@ static bool __mptcp_move_skbs(struct mptcp_sock *msk) 
	return !skb_queue_empty(&msk->receive_queue);

}



static unsigned int mptcp_inq_hint(const struct sock *sk)

{

	const struct mptcp_sock *msk = mptcp_sk(sk);

	const struct sk_buff *skb;



	skb = skb_peek(&msk->receive_queue);

	if (skb) {

		u64 hint_val = msk->ack_seq - MPTCP_SKB_CB(skb)->map_seq;



		if (hint_val >= INT_MAX)

			return INT_MAX;



		return (unsigned int)hint_val;

	}



	if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))

		return 1;



	return 0;

}



static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,

			 int nonblock, int flags, int *addr_len)

{
@@ -1989,6 +2014,9 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 
	len = min_t(size_t, len, INT_MAX);

	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);



	if (unlikely(msk->recvmsg_inq))

		cmsg_flags = MPTCP_CMSG_INQ;



	while (copied < len) {

		int bytes_read;
@@ -2062,6 +2090,12 @@ static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 
	if (cmsg_flags && copied >= 0) {

		if (cmsg_flags & MPTCP_CMSG_TS)

			tcp_recv_timestamp(msg, sk, &tss);



		if (cmsg_flags & MPTCP_CMSG_INQ) {

			unsigned int inq = mptcp_inq_hint(sk);



			put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(inq), &inq);

		}

	}



	pr_debug("msk=%p rx queue empty=%d:%d copied=%d",

net/mptcp/protocol.h

+1 −0
Original line number Diff line number Diff line
@@ -249,6 +249,7 @@ struct mptcp_sock { 
	bool		rcv_fastclose;

	bool		use_64bit_ack; /* Set when we received a 64-bit DSN */

	bool		csum_enabled;

	u8		recvmsg_inq:1;

	spinlock_t	join_list_lock;

	struct work_struct work;

	struct sk_buff  *ooo_last_skb;

net/mptcp/sockopt.c

+37 −1
Original line number Diff line number Diff line
@@ -557,6 +557,7 @@ static bool mptcp_supported_sockopt(int level, int optname) 
		case TCP_TIMESTAMP:

		case TCP_NOTSENT_LOWAT:

		case TCP_TX_DELAY:

		case TCP_INQ:

			return true;

		}
@@ -568,7 +569,6 @@ static bool mptcp_supported_sockopt(int level, int optname) 
		/* TCP_FASTOPEN_KEY, TCP_FASTOPEN TCP_FASTOPEN_CONNECT, TCP_FASTOPEN_NO_COOKIE,

		 * are not supported fastopen is currently unsupported

		 */

		/* TCP_INQ is currently unsupported, needs some recvmsg work */

	}

	return false;

}
@@ -698,7 +698,21 @@ static int mptcp_setsockopt_v4(struct mptcp_sock *msk, int optname, 
static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname,

				    sockptr_t optval, unsigned int optlen)

{

	struct sock *sk = (void *)msk;

	int ret, val;



	switch (optname) {

	case TCP_INQ:

		ret = mptcp_get_int_option(msk, optval, optlen, &val);

		if (ret)

			return ret;

		if (val < 0 || val > 1)

			return -EINVAL;



		lock_sock(sk);

		msk->recvmsg_inq = !!val;

		release_sock(sk);

		return 0;

	case TCP_ULP:

		return -EOPNOTSUPP;

	case TCP_CONGESTION:
@@ -1032,6 +1046,26 @@ static int mptcp_getsockopt_subflow_addrs(struct mptcp_sock *msk, char __user *o 
	return 0;

}



static int mptcp_put_int_option(struct mptcp_sock *msk, char __user *optval,

				int __user *optlen, int val)

{

	int len;



	if (get_user(len, optlen))

		return -EFAULT;



	len = min_t(unsigned int, len, sizeof(int));

	if (len < 0)

		return -EINVAL;



	if (put_user(len, optlen))

		return -EFAULT;

	if (copy_to_user(optval, &val, len))

		return -EFAULT;



	return 0;

}



static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname,

				    char __user *optval, int __user *optlen)

{
@@ -1042,6 +1076,8 @@ static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname, 
	case TCP_CC_INFO:

		return mptcp_getsockopt_first_sf_only(msk, SOL_TCP, optname,

						      optval, optlen);

	case TCP_INQ:

		return mptcp_put_int_option(msk, optval, optlen, msk->recvmsg_inq);

	}

	return -EOPNOTSUPP;

}