1 files changed, 246 insertions, 86 deletions

diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index caf11920a878..bb3576ac0ad7 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -38,8 +38,10 @@
 #define pr_fmt(fmt) "TCP: " fmt
 
 #include <net/tcp.h>
+#include <net/tcp_ecn.h>
 #include <net/mptcp.h>
 #include <net/proto_memory.h>
+#include <net/psp.h>
 
 #include <linux/compiler.h>
 #include <linux/gfp.h>
@@ -319,60 +321,6 @@ static u16 tcp_select_window(struct sock *sk)
 	return new_win;
 }
 
-/* Packet ECN state for a SYN-ACK */
-static void tcp_ecn_send_synack(struct sock *sk, struct sk_buff *skb)
-{
-	const struct tcp_sock *tp = tcp_sk(sk);
-
-	TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_CWR;
-	if (tcp_ecn_disabled(tp))
-		TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_ECE;
-	else if (tcp_ca_needs_ecn(sk) ||
-		 tcp_bpf_ca_needs_ecn(sk))
-		INET_ECN_xmit(sk);
-}
-
-/* Packet ECN state for a SYN.  */
-static void tcp_ecn_send_syn(struct sock *sk, struct sk_buff *skb)
-{
-	struct tcp_sock *tp = tcp_sk(sk);
-	bool bpf_needs_ecn = tcp_bpf_ca_needs_ecn(sk);
-	bool use_ecn = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_ecn) == 1 ||
-		tcp_ca_needs_ecn(sk) || bpf_needs_ecn;
-
-	if (!use_ecn) {
-		const struct dst_entry *dst = __sk_dst_get(sk);
-
-		if (dst && dst_feature(dst, RTAX_FEATURE_ECN))
-			use_ecn = true;
-	}
-
-	tp->ecn_flags = 0;
-
-	if (use_ecn) {
-		TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_ECE | TCPHDR_CWR;
-		tcp_ecn_mode_set(tp, TCP_ECN_MODE_RFC3168);
-		if (tcp_ca_needs_ecn(sk) || bpf_needs_ecn)
-			INET_ECN_xmit(sk);
-	}
-}
-
-static void tcp_ecn_clear_syn(struct sock *sk, struct sk_buff *skb)
-{
-	if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_ecn_fallback))
-		/* tp->ecn_flags are cleared at a later point in time when
-		 * SYN ACK is ultimatively being received.
-		 */
-		TCP_SKB_CB(skb)->tcp_flags &= ~(TCPHDR_ECE | TCPHDR_CWR);
-}
-
-static void
-tcp_ecn_make_synack(const struct request_sock *req, struct tcphdr *th)
-{
-	if (inet_rsk(req)->ecn_ok)
-		th->ece = 1;
-}
-
 /* Set up ECN state for a packet on a ESTABLISHED socket that is about to
  * be sent.
  */
@@ -381,7 +329,15 @@ static void tcp_ecn_send(struct sock *sk, struct sk_buff *skb,
 {
 	struct tcp_sock *tp = tcp_sk(sk);
 
-	if (tcp_ecn_mode_rfc3168(tp)) {
+	if (!tcp_ecn_mode_any(tp))
+		return;
+
+	if (tcp_ecn_mode_accecn(tp)) {
+		if (!tcp_accecn_ace_fail_recv(tp))
+			INET_ECN_xmit(sk);
+		tcp_accecn_set_ace(tp, skb, th);
+		skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ACCECN;
+	} else {
 		/* Not-retransmitted data segment: set ECT and inject CWR. */
 		if (skb->len != tcp_header_len &&
 		    !before(TCP_SKB_CB(skb)->seq, tp->snd_nxt)) {
@@ -403,13 +359,15 @@ static void tcp_ecn_send(struct sock *sk, struct sk_buff *skb,
 /* Constructs common control bits of non-data skb. If SYN/FIN is present,
  * auto increment end seqno.
  */
-static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u16 flags)
+static void tcp_init_nondata_skb(struct sk_buff *skb, struct sock *sk,
+				 u32 seq, u16 flags)
 {
 	skb->ip_summed = CHECKSUM_PARTIAL;
 
 	TCP_SKB_CB(skb)->tcp_flags = flags;
 
 	tcp_skb_pcount_set(skb, 1);
+	psp_enqueue_set_decrypted(sk, skb);
 
 	TCP_SKB_CB(skb)->seq = seq;
 	if (flags & (TCPHDR_SYN | TCPHDR_FIN))
@@ -430,6 +388,7 @@ static inline bool tcp_urg_mode(const struct tcp_sock *tp)
 #define OPTION_SMC		BIT(9)
 #define OPTION_MPTCP		BIT(10)
 #define OPTION_AO		BIT(11)
+#define OPTION_ACCECN		BIT(12)
 
 static void smc_options_write(__be32 *ptr, u16 *options)
 {
@@ -451,6 +410,8 @@ struct tcp_out_options {
 	u16 mss;		/* 0 to disable */
 	u8 ws;			/* window scale, 0 to disable */
 	u8 num_sack_blocks;	/* number of SACK blocks to include */
+	u8 num_accecn_fields:7,	/* number of AccECN fields needed */
+	   use_synack_ecn_bytes:1; /* Use synack_ecn_bytes or not */
 	u8 hash_size;		/* bytes in hash_location */
 	u8 bpf_opt_len;		/* length of BPF hdr option */
 	__u8 *hash_location;	/* temporary pointer, overloaded */
@@ -648,6 +609,11 @@ static __be32 *process_tcp_ao_options(struct tcp_sock *tp,
 	return ptr;
 }
 
+/* Initial values for AccECN option, ordered is based on ECN field bits
+ * similar to received_ecn_bytes. Used for SYN/ACK AccECN option.
+ */
+static const u32 synack_ecn_bytes[3] = { 0, 0, 0 };
+
 /* Write previously computed TCP options to the packet.
  *
  * Beware: Something in the Internet is very sensitive to the ordering of
@@ -666,6 +632,8 @@ static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
 			      struct tcp_out_options *opts,
 			      struct tcp_key *key)
 {
+	u8 leftover_highbyte = TCPOPT_NOP; /* replace 1st NOP if avail */
+	u8 leftover_lowbyte = TCPOPT_NOP;  /* replace 2nd NOP in succession */
 	__be32 *ptr = (__be32 *)(th + 1);
 	u16 options = opts->options;	/* mungable copy */
 
@@ -701,15 +669,75 @@ static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
 		*ptr++ = htonl(opts->tsecr);
 	}
 
+	if (OPTION_ACCECN & options) {
+		const u32 *ecn_bytes = opts->use_synack_ecn_bytes ?
+				       synack_ecn_bytes :
+				       tp->received_ecn_bytes;
+		const u8 ect0_idx = INET_ECN_ECT_0 - 1;
+		const u8 ect1_idx = INET_ECN_ECT_1 - 1;
+		const u8 ce_idx = INET_ECN_CE - 1;
+		u32 e0b;
+		u32 e1b;
+		u32 ceb;
+		u8 len;
+
+		e0b = ecn_bytes[ect0_idx] + TCP_ACCECN_E0B_INIT_OFFSET;
+		e1b = ecn_bytes[ect1_idx] + TCP_ACCECN_E1B_INIT_OFFSET;
+		ceb = ecn_bytes[ce_idx] + TCP_ACCECN_CEB_INIT_OFFSET;
+		len = TCPOLEN_ACCECN_BASE +
+		      opts->num_accecn_fields * TCPOLEN_ACCECN_PERFIELD;
+
+		if (opts->num_accecn_fields == 2) {
+			*ptr++ = htonl((TCPOPT_ACCECN1 << 24) | (len << 16) |
+				       ((e1b >> 8) & 0xffff));
+			*ptr++ = htonl(((e1b & 0xff) << 24) |
+				       (ceb & 0xffffff));
+		} else if (opts->num_accecn_fields == 1) {
+			*ptr++ = htonl((TCPOPT_ACCECN1 << 24) | (len << 16) |
+				       ((e1b >> 8) & 0xffff));
+			leftover_highbyte = e1b & 0xff;
+			leftover_lowbyte = TCPOPT_NOP;
+		} else if (opts->num_accecn_fields == 0) {
+			leftover_highbyte = TCPOPT_ACCECN1;
+			leftover_lowbyte = len;
+		} else if (opts->num_accecn_fields == 3) {
+			*ptr++ = htonl((TCPOPT_ACCECN1 << 24) | (len << 16) |
+				       ((e1b >> 8) & 0xffff));
+			*ptr++ = htonl(((e1b & 0xff) << 24) |
+				       (ceb & 0xffffff));
+			*ptr++ = htonl(((e0b & 0xffffff) << 8) |
+				       TCPOPT_NOP);
+		}
+		if (tp) {
+			tp->accecn_minlen = 0;
+			tp->accecn_opt_tstamp = tp->tcp_mstamp;
+			if (tp->accecn_opt_demand)
+				tp->accecn_opt_demand--;
+		}
+	}
+
 	if (unlikely(OPTION_SACK_ADVERTISE & options)) {
-		*ptr++ = htonl((TCPOPT_NOP << 24) |
-			       (TCPOPT_NOP << 16) |
+		*ptr++ = htonl((leftover_highbyte << 24) |
+			       (leftover_lowbyte << 16) |
 			       (TCPOPT_SACK_PERM << 8) |
 			       TCPOLEN_SACK_PERM);
+		leftover_highbyte = TCPOPT_NOP;
+		leftover_lowbyte = TCPOPT_NOP;
 	}
 
 	if (unlikely(OPTION_WSCALE & options)) {
-		*ptr++ = htonl((TCPOPT_NOP << 24) |
+		u8 highbyte = TCPOPT_NOP;
+
+		/* Do not split the leftover 2-byte to fit into a single
+		 * NOP, i.e., replace this NOP only when 1 byte is leftover
+		 * within leftover_highbyte.
+		 */
+		if (unlikely(leftover_highbyte != TCPOPT_NOP &&
+			     leftover_lowbyte == TCPOPT_NOP)) {
+			highbyte = leftover_highbyte;
+			leftover_highbyte = TCPOPT_NOP;
+		}
+		*ptr++ = htonl((highbyte << 24) |
 			       (TCPOPT_WINDOW << 16) |
 			       (TCPOLEN_WINDOW << 8) |
 			       opts->ws);
@@ -720,11 +748,13 @@ static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
 			tp->duplicate_sack : tp->selective_acks;
 		int this_sack;
 
-		*ptr++ = htonl((TCPOPT_NOP  << 24) |
-			       (TCPOPT_NOP  << 16) |
+		*ptr++ = htonl((leftover_highbyte << 24) |
+			       (leftover_lowbyte << 16) |
 			       (TCPOPT_SACK <<  8) |
 			       (TCPOLEN_SACK_BASE + (opts->num_sack_blocks *
 						     TCPOLEN_SACK_PERBLOCK)));
+		leftover_highbyte = TCPOPT_NOP;
+		leftover_lowbyte = TCPOPT_NOP;
 
 		for (this_sack = 0; this_sack < opts->num_sack_blocks;
 		     ++this_sack) {
@@ -733,6 +763,14 @@ static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp,
 		}
 
 		tp->rx_opt.dsack = 0;
+	} else if (unlikely(leftover_highbyte != TCPOPT_NOP ||
+			    leftover_lowbyte != TCPOPT_NOP)) {
+		*ptr++ = htonl((leftover_highbyte << 24) |
+			       (leftover_lowbyte << 16) |
+			       (TCPOPT_NOP << 8) |
+			       TCPOPT_NOP);
+		leftover_highbyte = TCPOPT_NOP;
+		leftover_lowbyte = TCPOPT_NOP;
 	}
 
 	if (unlikely(OPTION_FAST_OPEN_COOKIE & options)) {
@@ -813,6 +851,80 @@ static void mptcp_set_option_cond(const struct request_sock *req,
 	}
 }
 
+static u32 tcp_synack_options_combine_saving(struct tcp_out_options *opts)
+{
+	/* How much there's room for combining with the alignment padding? */
+	if ((opts->options & (OPTION_SACK_ADVERTISE | OPTION_TS)) ==
+	    OPTION_SACK_ADVERTISE)
+		return 2;
+	else if (opts->options & OPTION_WSCALE)
+		return 1;
+	return 0;
+}
+
+/* Calculates how long AccECN option will fit to @remaining option space.
+ *
+ * AccECN option can sometimes replace NOPs used for alignment of other
+ * TCP options (up to @max_combine_saving available).
+ *
+ * Only solutions with at least @required AccECN fields are accepted.
+ *
+ * Returns: The size of the AccECN option excluding space repurposed from
+ * the alignment of the other options.
+ */
+static int tcp_options_fit_accecn(struct tcp_out_options *opts, int required,
+				  int remaining)
+{
+	int size = TCP_ACCECN_MAXSIZE;
+	int sack_blocks_reduce = 0;
+	int max_combine_saving;
+	int rem = remaining;
+	int align_size;
+
+	if (opts->use_synack_ecn_bytes)
+		max_combine_saving = tcp_synack_options_combine_saving(opts);
+	else
+		max_combine_saving = opts->num_sack_blocks > 0 ? 2 : 0;
+	opts->num_accecn_fields = TCP_ACCECN_NUMFIELDS;
+	while (opts->num_accecn_fields >= required) {
+		/* Pad to dword if cannot combine */
+		if ((size & 0x3) > max_combine_saving)
+			align_size = ALIGN(size, 4);
+		else
+			align_size = ALIGN_DOWN(size, 4);
+
+		if (rem >= align_size) {
+			size = align_size;
+			break;
+		} else if (opts->num_accecn_fields == required &&
+			   opts->num_sack_blocks > 2 &&
+			   required > 0) {
+			/* Try to fit the option by removing one SACK block */
+			opts->num_sack_blocks--;
+			sack_blocks_reduce++;
+			rem = rem + TCPOLEN_SACK_PERBLOCK;
+
+			opts->num_accecn_fields = TCP_ACCECN_NUMFIELDS;
+			size = TCP_ACCECN_MAXSIZE;
+			continue;
+		}
+
+		opts->num_accecn_fields--;
+		size -= TCPOLEN_ACCECN_PERFIELD;
+	}
+	if (sack_blocks_reduce > 0) {
+		if (opts->num_accecn_fields >= required)
+			size -= sack_blocks_reduce * TCPOLEN_SACK_PERBLOCK;
+		else
+			opts->num_sack_blocks += sack_blocks_reduce;
+	}
+	if (opts->num_accecn_fields < required)
+		return 0;
+
+	opts->options |= OPTION_ACCECN;
+	return size;
+}
+
 /* Compute TCP options for SYN packets. This is not the final
  * network wire format yet.
  */
@@ -895,6 +1007,20 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb,
 		}
 	}
 
+	/* Simultaneous open SYN/ACK needs AccECN option but not SYN.
+	 * It is attempted to negotiate the use of AccECN also on the first
+	 * retransmitted SYN, as mentioned in "3.1.4.1. Retransmitted SYNs"
+	 * of AccECN draft.
+	 */
+	if (unlikely((TCP_SKB_CB(skb)->tcp_flags & TCPHDR_ACK) &&
+		     tcp_ecn_mode_accecn(tp) &&
+		     inet_csk(sk)->icsk_retransmits < 2 &&
+		     READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_ecn_option) &&
+		     remaining >= TCPOLEN_ACCECN_BASE)) {
+		opts->use_synack_ecn_bytes = 1;
+		remaining -= tcp_options_fit_accecn(opts, 0, remaining);
+	}
+
 	bpf_skops_hdr_opt_len(sk, skb, NULL, NULL, 0, opts, &remaining);
 
 	return MAX_TCP_OPTION_SPACE - remaining;
@@ -912,6 +1038,7 @@ static unsigned int tcp_synack_options(const struct sock *sk,
 {
 	struct inet_request_sock *ireq = inet_rsk(req);
 	unsigned int remaining = MAX_TCP_OPTION_SPACE;
+	struct tcp_request_sock *treq = tcp_rsk(req);
 
 	if (tcp_key_is_md5(key)) {
 		opts->options |= OPTION_MD5;
@@ -974,6 +1101,13 @@ static unsigned int tcp_synack_options(const struct sock *sk,
 
 	smc_set_option_cond(tcp_sk(sk), ireq, opts, &remaining);
 
+	if (treq->accecn_ok &&
+	    READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_ecn_option) &&
+	    req->num_timeout < 1 && remaining >= TCPOLEN_ACCECN_BASE) {
+		opts->use_synack_ecn_bytes = 1;
+		remaining -= tcp_options_fit_accecn(opts, 0, remaining);
+	}
+
 	bpf_skops_hdr_opt_len((struct sock *)sk, skb, req, syn_skb,
 			      synack_type, opts, &remaining);
 
@@ -1030,17 +1164,32 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb
 	eff_sacks = tp->rx_opt.num_sacks + tp->rx_opt.dsack;
 	if (unlikely(eff_sacks)) {
 		const unsigned int remaining = MAX_TCP_OPTION_SPACE - size;
-		if (unlikely(remaining < TCPOLEN_SACK_BASE_ALIGNED +
-					 TCPOLEN_SACK_PERBLOCK))
-			return size;
+		if (likely(remaining >= TCPOLEN_SACK_BASE_ALIGNED +
+					TCPOLEN_SACK_PERBLOCK)) {
+			opts->num_sack_blocks =
+				min_t(unsigned int, eff_sacks,
+				      (remaining - TCPOLEN_SACK_BASE_ALIGNED) /
+				      TCPOLEN_SACK_PERBLOCK);
+
+			size += TCPOLEN_SACK_BASE_ALIGNED +
+				opts->num_sack_blocks * TCPOLEN_SACK_PERBLOCK;
+		} else {
+			opts->num_sack_blocks = 0;
+		}
+	} else {
+		opts->num_sack_blocks = 0;
+	}
 
-		opts->num_sack_blocks =
-			min_t(unsigned int, eff_sacks,
-			      (remaining - TCPOLEN_SACK_BASE_ALIGNED) /
-			      TCPOLEN_SACK_PERBLOCK);
+	if (tcp_ecn_mode_accecn(tp)) {
+		int ecn_opt = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_ecn_option);
 
-		size += TCPOLEN_SACK_BASE_ALIGNED +
-			opts->num_sack_blocks * TCPOLEN_SACK_PERBLOCK;
+		if (ecn_opt && tp->saw_accecn_opt && !tcp_accecn_opt_fail_send(tp) &&
+		    (ecn_opt >= TCP_ACCECN_OPTION_FULL || tp->accecn_opt_demand ||
+		     tcp_accecn_option_beacon_check(sk))) {
+			opts->use_synack_ecn_bytes = 0;
+			size += tcp_options_fit_accecn(opts, tp->accecn_minlen,
+						       MAX_TCP_OPTION_SPACE - size);
+		}
 	}
 
 	if (unlikely(BPF_SOCK_OPS_TEST_FLAG(tp,
@@ -1437,7 +1586,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb,
 		err = tcp_ao_transmit_skb(sk, skb, key.ao_key, th,
 					  opts.hash_location);
 		if (err) {
-			kfree_skb_reason(skb, SKB_DROP_REASON_NOT_SPECIFIED);
+			sk_skb_reason_drop(sk, skb, SKB_DROP_REASON_NOT_SPECIFIED);
 			return -ENOMEM;
 		}
 	}
@@ -1510,6 +1659,7 @@ static void tcp_queue_skb(struct sock *sk, struct sk_buff *skb)
 	/* Advance write_seq and place onto the write_queue. */
 	WRITE_ONCE(tp->write_seq, TCP_SKB_CB(skb)->end_seq);
 	__skb_header_release(skb);
+	psp_enqueue_set_decrypted(sk, skb);
 	tcp_add_write_queue_tail(sk, skb);
 	sk_wmem_queued_add(sk, skb->truesize);
 	sk_mem_charge(sk, skb->truesize);
@@ -2750,6 +2900,11 @@ static bool tcp_write_xmit(struct sock *sk, unsigned int mss_now, int nonagle,
 	sent_pkts = 0;
 
 	tcp_mstamp_refresh(tp);
+
+	/* AccECN option beacon depends on mstamp, it may change mss */
+	if (tcp_ecn_mode_accecn(tp) && tcp_accecn_option_beacon_check(sk))
+		mss_now = tcp_current_mss(sk);
+
 	if (!push_one) {
 		/* Do MTU probing. */
 		result = tcp_mtu_probe(sk);
@@ -3402,7 +3557,10 @@ start:
 			tcp_retrans_try_collapse(sk, skb, avail_wnd);
 	}
 
-	/* RFC3168, section 6.1.1.1. ECN fallback */
+	/* RFC3168, section 6.1.1.1. ECN fallback
+	 * As AccECN uses the same SYN flags (+ AE), this check covers both
+	 * cases.
+	 */
 	if ((TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN_ECN) == TCPHDR_SYN_ECN)
 		tcp_ecn_clear_syn(sk, skb);
 
@@ -3578,9 +3736,8 @@ void sk_forced_mem_schedule(struct sock *sk, int size)
 	sk_forward_alloc_add(sk, amt << PAGE_SHIFT);
 	sk_memory_allocated_add(sk, amt);
 
-	if (mem_cgroup_sockets_enabled && sk->sk_memcg)
-		mem_cgroup_charge_skmem(sk->sk_memcg, amt,
-					gfp_memcg_charge() | __GFP_NOFAIL);
+	if (mem_cgroup_sk_enabled(sk))
+		mem_cgroup_sk_charge(sk, amt, gfp_memcg_charge() | __GFP_NOFAIL);
 }
 
 /* Send a FIN. The caller locks the socket for us.
@@ -3625,7 +3782,7 @@ void tcp_send_fin(struct sock *sk)
 		skb_reserve(skb, MAX_TCP_HEADER);
 		sk_forced_mem_schedule(sk, skb->truesize);
 		/* FIN eats a sequence byte, write_seq advanced by tcp_queue_skb(). */
-		tcp_init_nondata_skb(skb, tp->write_seq,
+		tcp_init_nondata_skb(skb, sk, tp->write_seq,
 				     TCPHDR_ACK | TCPHDR_FIN);
 		tcp_queue_skb(sk, skb);
 	}
@@ -3653,7 +3810,7 @@ void tcp_send_active_reset(struct sock *sk, gfp_t priority,
 
 	/* Reserve space for headers and prepare control bits. */
 	skb_reserve(skb, MAX_TCP_HEADER);
-	tcp_init_nondata_skb(skb, tcp_acceptable_seq(sk),
+	tcp_init_nondata_skb(skb, sk, tcp_acceptable_seq(sk),
 			     TCPHDR_ACK | TCPHDR_RST);
 	tcp_mstamp_refresh(tcp_sk(sk));
 	/* Send it off. */
@@ -3891,6 +4048,7 @@ 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.
@@ -3903,8 +4061,9 @@ 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));
@@ -3955,7 +4114,7 @@ static void tcp_connect_init(struct sock *sk)
 	WRITE_ONCE(tp->copied_seq, tp->rcv_nxt);
 
 	inet_csk(sk)->icsk_rto = tcp_timeout_init(sk);
-	inet_csk(sk)->icsk_retransmits = 0;
+	WRITE_ONCE(inet_csk(sk)->icsk_retransmits, 0);
 	tcp_clear_retrans(tp);
 }
 
@@ -4148,7 +4307,7 @@ int tcp_connect(struct sock *sk)
 	/* SYN eats a sequence byte, write_seq updated by
 	 * tcp_connect_queue_skb().
 	 */
-	tcp_init_nondata_skb(buff, tp->write_seq, TCPHDR_SYN);
+	tcp_init_nondata_skb(buff, sk, tp->write_seq, TCPHDR_SYN);
 	tcp_mstamp_refresh(tp);
 	tp->retrans_stamp = tcp_time_stamp_ts(tp);
 	tcp_connect_queue_skb(sk, buff);
@@ -4273,7 +4432,8 @@ void __tcp_send_ack(struct sock *sk, u32 rcv_nxt, u16 flags)
 
 	/* Reserve space for headers and prepare control bits. */
 	skb_reserve(buff, MAX_TCP_HEADER);
-	tcp_init_nondata_skb(buff, tcp_acceptable_seq(sk), TCPHDR_ACK | flags);
+	tcp_init_nondata_skb(buff, sk,
+			     tcp_acceptable_seq(sk), TCPHDR_ACK | flags);
 
 	/* We do not want pure acks influencing TCP Small Queues or fq/pacing
 	 * too much.
@@ -4319,7 +4479,7 @@ static int tcp_xmit_probe_skb(struct sock *sk, int urgent, int mib)
 	 * end to send an ack.  Don't queue or clone SKB, just
 	 * send it.
 	 */
-	tcp_init_nondata_skb(skb, tp->snd_una - !urgent, TCPHDR_ACK);
+	tcp_init_nondata_skb(skb, sk, tp->snd_una - !urgent, TCPHDR_ACK);
 	NET_INC_STATS(sock_net(sk), mib);
 	return tcp_transmit_skb(sk, skb, 0, (__force gfp_t)0);
 }
@@ -4393,13 +4553,13 @@ void tcp_send_probe0(struct sock *sk)
 
 	if (tp->packets_out || tcp_write_queue_empty(sk)) {
 		/* Cancel probe timer, if it is not required. */
-		icsk->icsk_probes_out = 0;
+		WRITE_ONCE(icsk->icsk_probes_out, 0);
 		icsk->icsk_backoff = 0;
 		icsk->icsk_probes_tstamp = 0;
 		return;
 	}
 
-	icsk->icsk_probes_out++;
+	WRITE_ONCE(icsk->icsk_probes_out, icsk->icsk_probes_out + 1);
 	if (err <= 0) {
 		if (icsk->icsk_backoff < READ_ONCE(net->ipv4.sysctl_tcp_retries2))
 			icsk->icsk_backoff++;
@@ -4437,7 +4597,7 @@ int tcp_rtx_synack(const struct sock *sk, struct request_sock *req)
 			tcp_sk_rw(sk)->total_retrans++;
 		}
 		trace_tcp_retransmit_synack(sk, req);
-		req->num_retrans++;
+		WRITE_ONCE(req->num_retrans, req->num_retrans + 1);
 	}
 	return res;
 }