Commit 718d6e86 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

Merge branch 'tcp-user_mss-and-tcp_maxseg-series' 

Eric Dumazet says:

====================
tcp: user_mss and TCP_MAXSEG series

Annotate data-races around tp->rx_opt.user_mss and make
TCP_MAXSEG lockless.
====================

Link: https://patch.msgid.link/20250821141901.18839-1-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parents 02614eee 9217146f

drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.c

+4 −2
Original line number Diff line number Diff line
@@ -951,6 +951,7 @@ static unsigned int chtls_select_mss(const struct chtls_sock *csk, 
	struct tcp_sock *tp;

	unsigned int mss;

	struct sock *sk;

	u16 user_mss;



	mss = ntohs(req->tcpopt.mss);

	sk = csk->sk;
@@ -969,8 +970,9 @@ static unsigned int chtls_select_mss(const struct chtls_sock *csk, 
		tcpoptsz += round_up(TCPOLEN_TIMESTAMP, 4);



	tp->advmss = dst_metric_advmss(dst);

	if (USER_MSS(tp) && tp->advmss > USER_MSS(tp))

		tp->advmss = USER_MSS(tp);

	user_mss = USER_MSS(tp);

	if (user_mss && tp->advmss > user_mss)

		tp->advmss = user_mss;

	if (tp->advmss > pmtu - iphdrsz)

		tp->advmss = pmtu - iphdrsz;

	if (mss && tp->advmss > mss)

drivers/net/ethernet/chelsio/inline_crypto/chtls/chtls_cm.h

+1 −1
Original line number Diff line number Diff line
@@ -90,7 +90,7 @@ struct deferred_skb_cb { 


#define SND_WSCALE(tp) ((tp)->rx_opt.snd_wscale)

#define RCV_WSCALE(tp) ((tp)->rx_opt.rcv_wscale)

#define USER_MSS(tp) ((tp)->rx_opt.user_mss)

#define USER_MSS(tp) (READ_ONCE((tp)->rx_opt.user_mss))

#define TS_RECENT_STAMP(tp) ((tp)->rx_opt.ts_recent_stamp)

#define WSCALE_OK(tp) ((tp)->rx_opt.wscale_ok)

#define TSTAMP_OK(tp) ((tp)->rx_opt.tstamp_ok)

net/ipv4/tcp.c

+7 −7
Original line number Diff line number Diff line
@@ -3760,7 +3760,7 @@ int tcp_sock_set_maxseg(struct sock *sk, int val) 
	if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW))

		return -EINVAL;



	tcp_sk(sk)->rx_opt.user_mss = val;

	WRITE_ONCE(tcp_sk(sk)->rx_opt.user_mss, val);

	return 0;

}
@@ -3890,15 +3890,13 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname, 
		WRITE_ONCE(inet_csk(sk)->icsk_delack_max, delack_max);

		return 0;

	}

	case TCP_MAXSEG:

		return tcp_sock_set_maxseg(sk, val);

	}



	sockopt_lock_sock(sk);



	switch (optname) {

	case TCP_MAXSEG:

		err = tcp_sock_set_maxseg(sk, val);

		break;



	case TCP_NODELAY:

		__tcp_sock_set_nodelay(sk, val);

		break;
@@ -4383,6 +4381,7 @@ int do_tcp_getsockopt(struct sock *sk, int level, 
	struct inet_connection_sock *icsk = inet_csk(sk);

	struct tcp_sock *tp = tcp_sk(sk);

	struct net *net = sock_net(sk);

	int user_mss;

	int val, len;



	if (copy_from_sockptr(&len, optlen, sizeof(int)))
@@ -4396,9 +4395,10 @@ int do_tcp_getsockopt(struct sock *sk, int level, 
	switch (optname) {

	case TCP_MAXSEG:

		val = tp->mss_cache;

		if (tp->rx_opt.user_mss &&

		user_mss = READ_ONCE(tp->rx_opt.user_mss);

		if (user_mss &&

		    ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))

			val = tp->rx_opt.user_mss;

			val = user_mss;

		if (tp->repair)

			val = tp->rx_opt.mss_clamp;

		break;

net/ipv4/tcp_input.c

+4 −4
Original line number Diff line number Diff line
@@ -6297,7 +6297,7 @@ static bool tcp_rcv_fastopen_synack(struct sock *sk, struct sk_buff *synack, 
	u16 mss = tp->rx_opt.mss_clamp, try_exp = 0;

	bool syn_drop = false;



	if (mss == tp->rx_opt.user_mss) {

	if (mss == READ_ONCE(tp->rx_opt.user_mss)) {

		struct tcp_options_received opt;



		/* Get original SYNACK MSS value if user MSS sets mss_clamp */
@@ -7117,7 +7117,7 @@ u16 tcp_get_syncookie_mss(struct request_sock_ops *rsk_ops, 
		return 0;

	}



	mss = tcp_parse_mss_option(th, tp->rx_opt.user_mss);

	mss = tcp_parse_mss_option(th, READ_ONCE(tp->rx_opt.user_mss));

	if (!mss)

		mss = af_ops->mss_clamp;
@@ -7131,7 +7131,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, 
{

	struct tcp_fastopen_cookie foc = { .len = -1 };

	struct tcp_options_received tmp_opt;

	struct tcp_sock *tp = tcp_sk(sk);

	const struct tcp_sock *tp = tcp_sk(sk);

	struct net *net = sock_net(sk);

	struct sock *fastopen_sk = NULL;

	struct request_sock *req;
@@ -7182,7 +7182,7 @@ int tcp_conn_request(struct request_sock_ops *rsk_ops, 


	tcp_clear_options(&tmp_opt);

	tmp_opt.mss_clamp = af_ops->mss_clamp;

	tmp_opt.user_mss  = tp->rx_opt.user_mss;

	tmp_opt.user_mss  = READ_ONCE(tp->rx_opt.user_mss);

	tcp_parse_options(sock_net(sk), skb, &tmp_opt, 0,

			  want_cookie ? NULL : &foc);

net/ipv4/tcp_output.c

+4 −2
Original line number Diff line number Diff line
@@ -3890,6 +3890,7 @@ static void tcp_connect_init(struct sock *sk) 
	const struct dst_entry *dst = __sk_dst_get(sk);

	struct tcp_sock *tp = tcp_sk(sk);

	__u8 rcv_wscale;

	u16 user_mss;

	u32 rcv_wnd;



	/* We'll fix this up when we get a response from the other end.
@@ -3902,8 +3903,9 @@ static void tcp_connect_init(struct sock *sk) 
	tcp_ao_connect_init(sk);



	/* If user gave his TCP_MAXSEG, record it to clamp */

	if (tp->rx_opt.user_mss)

		tp->rx_opt.mss_clamp = tp->rx_opt.user_mss;

	user_mss = READ_ONCE(tp->rx_opt.user_mss);

	if (user_mss)

		tp->rx_opt.mss_clamp = user_mss;

	tp->max_window = 0;

	tcp_mtup_init(sk);

	tcp_sync_mss(sk, dst_mtu(dst));