1 files changed, 40 insertions, 1 deletions

diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index 5c5e7db520dc..388750ddc57a 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -22,6 +22,7 @@
 #include <net/pkt_cls.h>
 #include <net/sch_generic.h>
 #include <net/sock.h>
+#include <net/tcp.h>
 
 static LIST_HEAD(taprio_list);
 static DEFINE_SPINLOCK(taprio_list_lock);
@@ -267,6 +268,41 @@ static bool is_valid_interval(struct sk_buff *skb, struct Qdisc *sch)
 	return entry;
 }
 
+/* This returns the tstamp value set by TCP in terms of the set clock. */
+static ktime_t get_tcp_tstamp(struct taprio_sched *q, struct sk_buff *skb)
+{
+	unsigned int offset = skb_network_offset(skb);
+	const struct ipv6hdr *ipv6h;
+	const struct iphdr *iph;
+	struct ipv6hdr _ipv6h;
+
+	ipv6h = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
+	if (!ipv6h)
+		return 0;
+
+	if (ipv6h->version == 4) {
+		iph = (struct iphdr *)ipv6h;
+		offset += iph->ihl * 4;
+
+		/* special-case 6in4 tunnelling, as that is a common way to get
+		 * v6 connectivity in the home
+		 */
+		if (iph->protocol == IPPROTO_IPV6) {
+			ipv6h = skb_header_pointer(skb, offset,
+						   sizeof(_ipv6h), &_ipv6h);
+
+			if (!ipv6h || ipv6h->nexthdr != IPPROTO_TCP)
+				return 0;
+		} else if (iph->protocol != IPPROTO_TCP) {
+			return 0;
+		}
+	} else if (ipv6h->version == 6 && ipv6h->nexthdr != IPPROTO_TCP) {
+		return 0;
+	}
+
+	return ktime_mono_to_any(skb->skb_mstamp_ns, q->tk_offset);
+}
+
 /* There are a few scenarios where we will have to modify the txtime from
  * what is read from next_txtime in sched_entry. They are:
  * 1. If txtime is in the past,
@@ -284,7 +320,7 @@ static bool is_valid_interval(struct sk_buff *skb, struct Qdisc *sch)
  */
 static long get_packet_txtime(struct sk_buff *skb, struct Qdisc *sch)
 {
-	ktime_t transmit_end_time, interval_end, interval_start;
+	ktime_t transmit_end_time, interval_end, interval_start, tcp_tstamp;
 	struct taprio_sched *q = qdisc_priv(sch);
 	struct sched_gate_list *sched, *admin;
 	ktime_t minimum_time, now, txtime;
@@ -295,6 +331,9 @@ static long get_packet_txtime(struct sk_buff *skb, struct Qdisc *sch)
 	now = taprio_get_time(q);
 	minimum_time = ktime_add_ns(now, q->txtime_delay);
 
+	tcp_tstamp = get_tcp_tstamp(q, skb);
+	minimum_time = max_t(ktime_t, minimum_time, tcp_tstamp);
+
 	rcu_read_lock();
 	admin = rcu_dereference(q->admin_sched);
 	sched = rcu_dereference(q->oper_sched);