[PATCH net-next v2 00/11] BIG TCP without HBH in IPv6

[PATCH net-next v2 00/11] BIG TCP without HBH in IPv6

[Alice Mikityanska]

From: Alice Mikityanska <alice@isovalent.com>

This series is part 1 of v2 of "BIG TCP for UDP tunnels". Due to the
number of patches, I'm splitting it into two logical parts:

* Remove hop-by-hop header for BIG TCP IPv6 to align with BIG TCP IPv4.
* Fix up things that prevent BIG TCP from working with UDP tunnels.

The current BIG TCP IPv6 code inserts a hop-by-hop extension header with
32-bit length of the packet. When the packet is encapsulated, and either
the outer or the inner protocol is IPv6, or both are IPv6, there will be
1 or 2 HBH headers that need to be dealt with. The issues that arise:

1. The drivers don't strip it, and they'd all need to know the structure
of each tunnel protocol in order to strip it correctly, also taking into
account all combinations of IPv4/IPv6 inner/outer protocols.

2. Even if (1) is implemented, it would be an additional performance
penalty per aggregated packet.

3. The skb_gso_validate_network_len check is skipped in
ip6_finish_output_gso when IP6SKB_FAKEJUMBO is set, but it seems that it
would make sense to do the actual validation, just taking into account
the length of the HBH header. When the support for tunnels is added, it
becomes trickier, because there may be one or two HBH headers, depending
on whether it's IPv6 in IPv6 or not.

At the same time, having an HBH header to store the 32-bit length is not
strictly necessary, as BIG TCP IPv4 doesn't do anything like this and
just restores the length from skb->len. The same thing can be done for
BIG TCP IPv6. Removing HBH from BIG TCP would allow to simplify the
implementation significantly, and align it with BIG TCP IPv4, which has
been a long-standing goal.

v1: https://lore.kernel.org/netdev/20250923134742.1399800-1-maxtram95@gmail.com/

v2 changes:

Split the series into two parts. Address the review comments in part 2
(details follow with part 2).

P.S. Author had her name changed since v1; it's the same person.

Alice Mikityanska (11):
  net/ipv6: Introduce payload_len helpers
  net/ipv6: Drop HBH for BIG TCP on TX side
  net/ipv6: Drop HBH for BIG TCP on RX side
  net/ipv6: Remove jumbo_remove step from TX path
  net/mlx5e: Remove jumbo_remove step from TX path
  net/mlx4: Remove jumbo_remove step from TX path
  ice: Remove jumbo_remove step from TX path
  bnxt_en: Remove jumbo_remove step from TX path
  gve: Remove jumbo_remove step from TX path
  net: mana: Remove jumbo_remove step from TX path
  net/ipv6: Remove HBH helpers

 drivers/net/ethernet/broadcom/bnxt/bnxt.c     | 21 -----
 drivers/net/ethernet/google/gve/gve_tx_dqo.c  |  3 -
 drivers/net/ethernet/intel/ice/ice_txrx.c     |  3 -
 drivers/net/ethernet/mellanox/mlx4/en_tx.c    | 42 ++--------
 .../net/ethernet/mellanox/mlx5/core/en_tx.c   | 75 +++---------------
 drivers/net/ethernet/microsoft/mana/mana_en.c |  3 -
 include/linux/ipv6.h                          | 21 ++++-
 include/net/ipv6.h                            | 79 -------------------
 include/net/netfilter/nf_tables_ipv6.h        |  4 +-
 net/bridge/br_netfilter_ipv6.c                |  2 +-
 net/bridge/netfilter/nf_conntrack_bridge.c    |  4 +-
 net/core/dev.c                                |  6 +-
 net/core/gro.c                                |  2 -
 net/ipv6/ip6_input.c                          |  2 +-
 net/ipv6/ip6_offload.c                        | 36 +--------
 net/ipv6/ip6_output.c                         | 20 +----
 net/ipv6/output_core.c                        |  7 +-
 net/netfilter/ipvs/ip_vs_xmit.c               |  2 +-
 net/netfilter/nf_conntrack_ovs.c              |  2 +-
 net/netfilter/nf_log_syslog.c                 |  2 +-
 net/sched/sch_cake.c                          |  2 +-
 21 files changed, 59 insertions(+), 279 deletions(-)

-- 
2.52.0

[PATCH net-next v2 01/11] net/ipv6: Introduce payload_len helpers

[Alice Mikityanska]

From: Alice Mikityanska <alice@isovalent.com>

The next commits will transition away from using the hop-by-hop
extension header to encode packet length for BIG TCP. Add wrappers
around ip6->payload_len that return the actual value if it's non-zero,
and calculate it from skb->len if payload_len is set to zero (and a
symmetrical setter).

The new helpers are used wherever the surrounding code supports the
hop-by-hop jumbo header for BIG TCP IPv6, or the corresponding IPv4 code
uses skb_ip_totlen (e.g., in include/net/netfilter/nf_tables_ipv6.h).

No behavioral change in this commit.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
---
 include/linux/ipv6.h                       | 20 ++++++++++++++++++++
 include/net/ipv6.h                         |  2 --
 include/net/netfilter/nf_tables_ipv6.h     |  4 ++--
 net/bridge/br_netfilter_ipv6.c             |  2 +-
 net/bridge/netfilter/nf_conntrack_bridge.c |  4 ++--
 net/ipv6/ip6_input.c                       |  2 +-
 net/ipv6/ip6_offload.c                     |  7 +++----
 net/ipv6/output_core.c                     |  7 +------
 net/netfilter/ipvs/ip_vs_xmit.c            |  2 +-
 net/netfilter/nf_conntrack_ovs.c           |  2 +-
 net/netfilter/nf_log_syslog.c              |  2 +-
 net/sched/sch_cake.c                       |  2 +-
 12 files changed, 34 insertions(+), 22 deletions(-)

diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 7294e4e89b79..9dd05743de36 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -126,6 +126,26 @@ static inline unsigned int ipv6_transport_len(const struct sk_buff *skb)
 	       skb_network_header_len(skb);
 }
 
+static inline unsigned int ipv6_payload_len(const struct sk_buff *skb, const struct ipv6hdr *ip6)
+{
+	u32 len = ntohs(ip6->payload_len);
+
+	return (len || !skb_is_gso(skb) || !skb_is_gso_tcp(skb)) ?
+	       len : skb->len - skb_network_offset(skb) - sizeof(struct ipv6hdr);
+}
+
+static inline unsigned int skb_ipv6_payload_len(const struct sk_buff *skb)
+{
+	return ipv6_payload_len(skb, ipv6_hdr(skb));
+}
+
+#define IPV6_MAXPLEN		65535
+
+static inline void ipv6_set_payload_len(struct ipv6hdr *ip6, unsigned int len)
+{
+	ip6->payload_len = len <= IPV6_MAXPLEN ? htons(len) : 0;
+}
+
 /* 
    This structure contains results of exthdrs parsing
    as offsets from skb->nh.
diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index 74fbf1ad8065..f65bcef57d80 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -25,8 +25,6 @@ struct ip_tunnel_info;
 
 #define SIN6_LEN_RFC2133	24
 
-#define IPV6_MAXPLEN		65535
-
 /*
  *	NextHeader field of IPv6 header
  */
diff --git a/include/net/netfilter/nf_tables_ipv6.h b/include/net/netfilter/nf_tables_ipv6.h
index a0633eeaec97..c53ac00bb974 100644
--- a/include/net/netfilter/nf_tables_ipv6.h
+++ b/include/net/netfilter/nf_tables_ipv6.h
@@ -42,7 +42,7 @@ static inline int __nft_set_pktinfo_ipv6_validate(struct nft_pktinfo *pkt)
 	if (ip6h->version != 6)
 		return -1;
 
-	pkt_len = ntohs(ip6h->payload_len);
+	pkt_len = ipv6_payload_len(pkt->skb, ip6h);
 	skb_len = pkt->skb->len - skb_network_offset(pkt->skb);
 	if (pkt_len + sizeof(*ip6h) > skb_len)
 		return -1;
@@ -86,7 +86,7 @@ static inline int nft_set_pktinfo_ipv6_ingress(struct nft_pktinfo *pkt)
 	if (ip6h->version != 6)
 		goto inhdr_error;
 
-	pkt_len = ntohs(ip6h->payload_len);
+	pkt_len = ipv6_payload_len(pkt->skb, ip6h);
 	if (pkt_len + sizeof(*ip6h) > pkt->skb->len) {
 		idev = __in6_dev_get(nft_in(pkt));
 		__IP6_INC_STATS(nft_net(pkt), idev, IPSTATS_MIB_INTRUNCATEDPKTS);
diff --git a/net/bridge/br_netfilter_ipv6.c b/net/bridge/br_netfilter_ipv6.c
index e0421eaa3abc..76ce70b4e7f3 100644
--- a/net/bridge/br_netfilter_ipv6.c
+++ b/net/bridge/br_netfilter_ipv6.c
@@ -58,7 +58,7 @@ int br_validate_ipv6(struct net *net, struct sk_buff *skb)
 	if (hdr->version != 6)
 		goto inhdr_error;
 
-	pkt_len = ntohs(hdr->payload_len);
+	pkt_len = ipv6_payload_len(skb, hdr);
 	if (hdr->nexthdr == NEXTHDR_HOP && nf_ip6_check_hbh_len(skb, &pkt_len))
 		goto drop;
 
diff --git a/net/bridge/netfilter/nf_conntrack_bridge.c b/net/bridge/netfilter/nf_conntrack_bridge.c
index 6482de4d8750..e3fd414906a0 100644
--- a/net/bridge/netfilter/nf_conntrack_bridge.c
+++ b/net/bridge/netfilter/nf_conntrack_bridge.c
@@ -230,7 +230,7 @@ static int nf_ct_br_ipv6_check(const struct sk_buff *skb)
 	if (hdr->version != 6)
 		return -1;
 
-	len = ntohs(hdr->payload_len) + sizeof(struct ipv6hdr) + nhoff;
+	len = ipv6_payload_len(skb, hdr) + sizeof(struct ipv6hdr) + nhoff;
 	if (skb->len < len)
 		return -1;
 
@@ -270,7 +270,7 @@ static unsigned int nf_ct_bridge_pre(void *priv, struct sk_buff *skb,
 		if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 			return NF_ACCEPT;
 
-		len = sizeof(struct ipv6hdr) + ntohs(ipv6_hdr(skb)->payload_len);
+		len = sizeof(struct ipv6hdr) + skb_ipv6_payload_len(skb);
 		if (pskb_trim_rcsum(skb, len))
 			return NF_ACCEPT;
 
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 168ec07e31cc..2bcb981c91aa 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c
@@ -262,7 +262,7 @@ static struct sk_buff *ip6_rcv_core(struct sk_buff *skb, struct net_device *dev,
 	skb->transport_header = skb->network_header + sizeof(*hdr);
 	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
 
-	pkt_len = ntohs(hdr->payload_len);
+	pkt_len = ipv6_payload_len(skb, hdr);
 
 	/* pkt_len may be zero if Jumbo payload option is present */
 	if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index fce91183797a..6762ce7909c8 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -372,12 +372,11 @@ INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
 		hop_jumbo->jumbo_payload_len = htonl(payload_len + hoplen);
 
 		iph->nexthdr = NEXTHDR_HOP;
-		iph->payload_len = 0;
-	} else {
-		iph = (struct ipv6hdr *)(skb->data + nhoff);
-		iph->payload_len = htons(payload_len);
 	}
 
+	iph = (struct ipv6hdr *)(skb->data + nhoff);
+	ipv6_set_payload_len(iph, payload_len);
+
 	nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops);
 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
 		goto out;
diff --git a/net/ipv6/output_core.c b/net/ipv6/output_core.c
index 1c9b283a4132..cba1684a3f30 100644
--- a/net/ipv6/output_core.c
+++ b/net/ipv6/output_core.c
@@ -125,12 +125,7 @@ EXPORT_SYMBOL(ip6_dst_hoplimit);
 
 int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb)
 {
-	int len;
-
-	len = skb->len - sizeof(struct ipv6hdr);
-	if (len > IPV6_MAXPLEN)
-		len = 0;
-	ipv6_hdr(skb)->payload_len = htons(len);
+	ipv6_set_payload_len(ipv6_hdr(skb), skb->len - sizeof(struct ipv6hdr));
 	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
 
 	/* if egress device is enslaved to an L3 master device pass the
diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index 64c697212578..f861d116cc33 100644
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -949,7 +949,7 @@ ip_vs_prepare_tunneled_skb(struct sk_buff *skb, int skb_af,
 		*next_protocol = IPPROTO_IPV6;
 		if (payload_len)
 			*payload_len =
-				ntohs(old_ipv6h->payload_len) +
+				ipv6_payload_len(skb, old_ipv6h) +
 				sizeof(*old_ipv6h);
 		old_dsfield = ipv6_get_dsfield(old_ipv6h);
 		*ttl = old_ipv6h->hop_limit;
diff --git a/net/netfilter/nf_conntrack_ovs.c b/net/netfilter/nf_conntrack_ovs.c
index 068e9489e1c2..a6988eeb1579 100644
--- a/net/netfilter/nf_conntrack_ovs.c
+++ b/net/netfilter/nf_conntrack_ovs.c
@@ -121,7 +121,7 @@ int nf_ct_skb_network_trim(struct sk_buff *skb, int family)
 		len = skb_ip_totlen(skb);
 		break;
 	case NFPROTO_IPV6:
-		len = ntohs(ipv6_hdr(skb)->payload_len);
+		len = skb_ipv6_payload_len(skb);
 		if (ipv6_hdr(skb)->nexthdr == NEXTHDR_HOP) {
 			int err = nf_ip6_check_hbh_len(skb, &len);
 
diff --git a/net/netfilter/nf_log_syslog.c b/net/netfilter/nf_log_syslog.c
index 86d5fc5d28e3..41503847d9d7 100644
--- a/net/netfilter/nf_log_syslog.c
+++ b/net/netfilter/nf_log_syslog.c
@@ -561,7 +561,7 @@ dump_ipv6_packet(struct net *net, struct nf_log_buf *m,
 
 	/* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */
 	nf_log_buf_add(m, "LEN=%zu TC=%u HOPLIMIT=%u FLOWLBL=%u ",
-		       ntohs(ih->payload_len) + sizeof(struct ipv6hdr),
+		       ipv6_payload_len(skb, ih) + sizeof(struct ipv6hdr),
 		       (ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20,
 		       ih->hop_limit,
 		       (ntohl(*(__be32 *)ih) & 0x000fffff));
diff --git a/net/sched/sch_cake.c b/net/sched/sch_cake.c
index e30ef7f8ee68..8e3135eb2ea9 100644
--- a/net/sched/sch_cake.c
+++ b/net/sched/sch_cake.c
@@ -1278,7 +1278,7 @@ static struct sk_buff *cake_ack_filter(struct cake_sched_data *q,
 			    ipv6_addr_cmp(&ipv6h_check->daddr, &ipv6h->daddr))
 				continue;
 
-			seglen = ntohs(ipv6h_check->payload_len);
+			seglen = ipv6_payload_len(skb, ipv6h_check);
 		} else {
 			WARN_ON(1);  /* shouldn't happen */
 			continue;
-- 
2.52.0

[PATCH net-next v2 02/11] net/ipv6: Drop HBH for BIG TCP on TX side

[Alice Mikityanska]

From: Alice Mikityanska <alice@isovalent.com>

BIG TCP IPv6 inserts a hop-by-hop extension header to indicate the real
IPv6 payload length when it doesn't fit into the 16-bit field in the
IPv6 header itself. While it helps tools parse the packet, it also
requires every driver that supports TSO and BIG TCP to remove this
8-byte extension header. It might not sound that bad until we try to
apply it to tunneled traffic. Currently, the drivers don't attempt to
strip HBH if skb->encapsulation = 1. Moreover, trying to do so would
require dissecting different tunnel protocols and making corresponding
adjustments on case-by-case basis, which would slow down the fastpath
(potentially also requiring adjusting checksums in outer headers).

At the same time, BIG TCP IPv4 doesn't insert any extra headers and just
calculates the payload length from skb->len, significantly simplifying
implementing BIG TCP for tunnels.

Stop inserting HBH when building BIG TCP GSO SKBs.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
---
 include/linux/ipv6.h  |  1 -
 net/ipv6/ip6_output.c | 20 +++-----------------
 2 files changed, 3 insertions(+), 18 deletions(-)

diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 9dd05743de36..e9c7127aaef3 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -175,7 +175,6 @@ struct inet6_skb_parm {
 #define IP6SKB_L3SLAVE         64
 #define IP6SKB_JUMBOGRAM      128
 #define IP6SKB_SEG6	      256
-#define IP6SKB_FAKEJUMBO      512
 #define IP6SKB_MULTIPATH      1024
 #define IP6SKB_MCROUTE        2048
 };
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index f904739e99b9..ed1b8e62ef61 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -179,8 +179,7 @@ ip6_finish_output_gso_slowpath_drop(struct net *net, struct sock *sk,
 static int ip6_finish_output_gso(struct net *net, struct sock *sk,
 				 struct sk_buff *skb, unsigned int mtu)
 {
-	if (!(IP6CB(skb)->flags & IP6SKB_FAKEJUMBO) &&
-	    !skb_gso_validate_network_len(skb, mtu))
+	if (!skb_gso_validate_network_len(skb, mtu))
 		return ip6_finish_output_gso_slowpath_drop(net, sk, skb, mtu);
 
 	return ip6_finish_output2(net, sk, skb);
@@ -273,8 +272,6 @@ int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 	struct in6_addr *first_hop = &fl6->daddr;
 	struct dst_entry *dst = skb_dst(skb);
 	struct inet6_dev *idev = ip6_dst_idev(dst);
-	struct hop_jumbo_hdr *hop_jumbo;
-	int hoplen = sizeof(*hop_jumbo);
 	struct net *net = sock_net(sk);
 	unsigned int head_room;
 	struct net_device *dev;
@@ -287,7 +284,7 @@ int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 	rcu_read_lock();
 
 	dev = dst_dev_rcu(dst);
-	head_room = sizeof(struct ipv6hdr) + hoplen + LL_RESERVED_SPACE(dev);
+	head_room = sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dev);
 	if (opt)
 		head_room += opt->opt_nflen + opt->opt_flen;
 
@@ -312,19 +309,8 @@ int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 					     &fl6->saddr);
 	}
 
-	if (unlikely(seg_len > IPV6_MAXPLEN)) {
-		hop_jumbo = skb_push(skb, hoplen);
-
-		hop_jumbo->nexthdr = proto;
-		hop_jumbo->hdrlen = 0;
-		hop_jumbo->tlv_type = IPV6_TLV_JUMBO;
-		hop_jumbo->tlv_len = 4;
-		hop_jumbo->jumbo_payload_len = htonl(seg_len + hoplen);
-
-		proto = IPPROTO_HOPOPTS;
+	if (unlikely(seg_len > IPV6_MAXPLEN))
 		seg_len = 0;
-		IP6CB(skb)->flags |= IP6SKB_FAKEJUMBO;
-	}
 
 	skb_push(skb, sizeof(struct ipv6hdr));
 	skb_reset_network_header(skb);
-- 
2.52.0

[PATCH net-next v2 03/11] net/ipv6: Drop HBH for BIG TCP on RX side

[Alice Mikityanska]

From: Alice Mikityanska <alice@isovalent.com>

Complementary to the previous commit, stop inserting HBH when building
BIG TCP GRO SKBs.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
---
 net/core/gro.c         |  2 --
 net/ipv6/ip6_offload.c | 28 +---------------------------
 2 files changed, 1 insertion(+), 29 deletions(-)

diff --git a/net/core/gro.c b/net/core/gro.c
index 76f9c3712422..b95df1d85946 100644
--- a/net/core/gro.c
+++ b/net/core/gro.c
@@ -115,8 +115,6 @@ int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb)
 
 	if (unlikely(p->len + len >= GRO_LEGACY_MAX_SIZE)) {
 		if (NAPI_GRO_CB(skb)->proto != IPPROTO_TCP ||
-		    (p->protocol == htons(ETH_P_IPV6) &&
-		     skb_headroom(p) < sizeof(struct hop_jumbo_hdr)) ||
 		    p->encapsulation)
 			return -E2BIG;
 	}
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index 6762ce7909c8..e5861089cc80 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -342,40 +342,14 @@ INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff)
 	const struct net_offload *ops;
 	struct ipv6hdr *iph;
 	int err = -ENOSYS;
-	u32 payload_len;
 
 	if (skb->encapsulation) {
 		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6));
 		skb_set_inner_network_header(skb, nhoff);
 	}
 
-	payload_len = skb->len - nhoff - sizeof(*iph);
-	if (unlikely(payload_len > IPV6_MAXPLEN)) {
-		struct hop_jumbo_hdr *hop_jumbo;
-		int hoplen = sizeof(*hop_jumbo);
-
-		/* Move network header left */
-		memmove(skb_mac_header(skb) - hoplen, skb_mac_header(skb),
-			skb->transport_header - skb->mac_header);
-		skb->data -= hoplen;
-		skb->len += hoplen;
-		skb->mac_header -= hoplen;
-		skb->network_header -= hoplen;
-		iph = (struct ipv6hdr *)(skb->data + nhoff);
-		hop_jumbo = (struct hop_jumbo_hdr *)(iph + 1);
-
-		/* Build hop-by-hop options */
-		hop_jumbo->nexthdr = iph->nexthdr;
-		hop_jumbo->hdrlen = 0;
-		hop_jumbo->tlv_type = IPV6_TLV_JUMBO;
-		hop_jumbo->tlv_len = 4;
-		hop_jumbo->jumbo_payload_len = htonl(payload_len + hoplen);
-
-		iph->nexthdr = NEXTHDR_HOP;
-	}
-
 	iph = (struct ipv6hdr *)(skb->data + nhoff);
-	ipv6_set_payload_len(iph, payload_len);
+	ipv6_set_payload_len(iph, skb->len - nhoff - sizeof(*iph));
 
 	nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops);
 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))
-- 
2.52.0

[PATCH net-next v2 04/11] net/ipv6: Remove jumbo_remove step from TX path

[Alice Mikityanska]

From: Alice Mikityanska <alice@isovalent.com>

Now that the kernel doesn't insert HBH for BIG TCP IPv6 packets, remove
unnecessary steps from the GSO TX path, that used to check and remove
HBH.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
---
 net/core/dev.c         | 6 ++----
 net/ipv6/ip6_offload.c | 5 +----
 2 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index c711da335510..fb142613ce1a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3800,8 +3800,7 @@ static netdev_features_t gso_features_check(const struct sk_buff *skb,
 	     (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 &&
 	      vlan_get_protocol(skb) == htons(ETH_P_IPV6))) &&
 	    skb_transport_header_was_set(skb) &&
-	    skb_network_header_len(skb) != sizeof(struct ipv6hdr) &&
-	    !ipv6_has_hopopt_jumbo(skb))
+	    skb_network_header_len(skb) != sizeof(struct ipv6hdr))
 		features &= ~(NETIF_F_IPV6_CSUM | NETIF_F_TSO6 | NETIF_F_GSO_UDP_L4);
 
 	return features;
@@ -3904,8 +3903,7 @@ int skb_csum_hwoffload_help(struct sk_buff *skb,
 
 	if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) {
 		if (vlan_get_protocol(skb) == htons(ETH_P_IPV6) &&
-		    skb_network_header_len(skb) != sizeof(struct ipv6hdr) &&
-		    !ipv6_has_hopopt_jumbo(skb))
+		    skb_network_header_len(skb) != sizeof(struct ipv6hdr))
 			goto sw_checksum;
 
 		switch (skb->csum_offset) {
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index e5861089cc80..3252a9c2ad58 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -110,7 +110,7 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
 	struct sk_buff *segs = ERR_PTR(-EINVAL);
 	struct ipv6hdr *ipv6h;
 	const struct net_offload *ops;
-	int proto, err;
+	int proto;
 	struct frag_hdr *fptr;
 	unsigned int payload_len;
 	u8 *prevhdr;
@@ -120,9 +120,6 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,
 	bool gso_partial;
 
 	skb_reset_network_header(skb);
-	err = ipv6_hopopt_jumbo_remove(skb);
-	if (err)
-		return ERR_PTR(err);
 	nhoff = skb_network_header(skb) - skb_mac_header(skb);
 	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
 		goto out;
-- 
2.52.0

[PATCH net-next v2 05/11] net/mlx5e: Remove jumbo_remove step from TX path

[Alice Mikityanska]

From: Alice Mikityanska <alice@isovalent.com>

Now that the kernel doesn't insert HBH for BIG TCP IPv6 packets, remove
unnecessary steps from the mlx5e and mlx5i TX path, that used to check
and remove HBH.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
---
 .../net/ethernet/mellanox/mlx5/core/en_tx.c   | 75 +++----------------
 1 file changed, 12 insertions(+), 63 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
index a01ee656a1e7..9f0272649fa1 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tx.c
@@ -152,12 +152,11 @@ mlx5e_txwqe_build_eseg_csum(struct mlx5e_txqsq *sq, struct sk_buff *skb,
  * to inline later in the transmit descriptor
  */
 static inline u16
-mlx5e_tx_get_gso_ihs(struct mlx5e_txqsq *sq, struct sk_buff *skb, int *hopbyhop)
+mlx5e_tx_get_gso_ihs(struct mlx5e_txqsq *sq, struct sk_buff *skb)
 {
 	struct mlx5e_sq_stats *stats = sq->stats;
 	u16 ihs;
 
-	*hopbyhop = 0;
 	if (skb->encapsulation) {
 		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
 			ihs = skb_inner_transport_offset(skb) +
@@ -167,17 +166,12 @@ mlx5e_tx_get_gso_ihs(struct mlx5e_txqsq *sq, struct sk_buff *skb, int *hopbyhop)
 		stats->tso_inner_packets++;
 		stats->tso_inner_bytes += skb->len - ihs;
 	} else {
-		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
+		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
 			ihs = skb_transport_offset(skb) + sizeof(struct udphdr);
-		} else {
+		else
 			ihs = skb_tcp_all_headers(skb);
-			if (ipv6_has_hopopt_jumbo(skb)) {
-				*hopbyhop = sizeof(struct hop_jumbo_hdr);
-				ihs -= sizeof(struct hop_jumbo_hdr);
-			}
-		}
 		stats->tso_packets++;
-		stats->tso_bytes += skb->len - ihs - *hopbyhop;
+		stats->tso_bytes += skb->len - ihs;
 	}
 
 	return ihs;
@@ -239,7 +233,6 @@ struct mlx5e_tx_attr {
 	__be16 mss;
 	u16 insz;
 	u8 opcode;
-	u8 hopbyhop;
 };
 
 struct mlx5e_tx_wqe_attr {
@@ -275,16 +268,14 @@ static void mlx5e_sq_xmit_prepare(struct mlx5e_txqsq *sq, struct sk_buff *skb,
 	struct mlx5e_sq_stats *stats = sq->stats;
 
 	if (skb_is_gso(skb)) {
-		int hopbyhop;
-		u16 ihs = mlx5e_tx_get_gso_ihs(sq, skb, &hopbyhop);
+		u16 ihs = mlx5e_tx_get_gso_ihs(sq, skb);
 
 		*attr = (struct mlx5e_tx_attr) {
 			.opcode    = MLX5_OPCODE_LSO,
 			.mss       = cpu_to_be16(skb_shinfo(skb)->gso_size),
 			.ihs       = ihs,
 			.num_bytes = skb->len + (skb_shinfo(skb)->gso_segs - 1) * ihs,
-			.headlen   = skb_headlen(skb) - ihs - hopbyhop,
-			.hopbyhop  = hopbyhop,
+			.headlen   = skb_headlen(skb) - ihs,
 		};
 
 		stats->packets += skb_shinfo(skb)->gso_segs;
@@ -439,7 +430,6 @@ mlx5e_sq_xmit_wqe(struct mlx5e_txqsq *sq, struct sk_buff *skb,
 	struct mlx5_wqe_data_seg *dseg;
 	struct mlx5e_tx_wqe_info *wi;
 	u16 ihs = attr->ihs;
-	struct ipv6hdr *h6;
 	struct mlx5e_sq_stats *stats = sq->stats;
 	int num_dma;
 
@@ -456,28 +446,7 @@ mlx5e_sq_xmit_wqe(struct mlx5e_txqsq *sq, struct sk_buff *skb,
 	if (ihs) {
 		u8 *start = eseg->inline_hdr.start;
 
-		if (unlikely(attr->hopbyhop)) {
-			/* remove the HBH header.
-			 * Layout: [Ethernet header][IPv6 header][HBH][TCP header]
-			 */
-			if (skb_vlan_tag_present(skb)) {
-				mlx5e_insert_vlan(start, skb, ETH_HLEN + sizeof(*h6));
-				ihs += VLAN_HLEN;
-				h6 = (struct ipv6hdr *)(start + sizeof(struct vlan_ethhdr));
-			} else {
-				unsafe_memcpy(start, skb->data,
-					      ETH_HLEN + sizeof(*h6),
-					      MLX5_UNSAFE_MEMCPY_DISCLAIMER);
-				h6 = (struct ipv6hdr *)(start + ETH_HLEN);
-			}
-			h6->nexthdr = IPPROTO_TCP;
-			/* Copy the TCP header after the IPv6 one */
-			memcpy(h6 + 1,
-			       skb->data + ETH_HLEN + sizeof(*h6) +
-					sizeof(struct hop_jumbo_hdr),
-			       tcp_hdrlen(skb));
-			/* Leave ipv6 payload_len set to 0, as LSO v2 specs request. */
-		} else if (skb_vlan_tag_present(skb)) {
+		if (skb_vlan_tag_present(skb)) {
 			mlx5e_insert_vlan(start, skb, ihs);
 			ihs += VLAN_HLEN;
 			stats->added_vlan_packets++;
@@ -491,7 +460,7 @@ mlx5e_sq_xmit_wqe(struct mlx5e_txqsq *sq, struct sk_buff *skb,
 	}
 
 	dseg += wqe_attr->ds_cnt_ids;
-	num_dma = mlx5e_txwqe_build_dsegs(sq, skb, skb->data + attr->ihs + attr->hopbyhop,
+	num_dma = mlx5e_txwqe_build_dsegs(sq, skb, skb->data + attr->ihs,
 					  attr->headlen, dseg);
 	if (unlikely(num_dma < 0))
 		goto err_drop;
@@ -1019,34 +988,14 @@ void mlx5i_sq_xmit(struct mlx5e_txqsq *sq, struct sk_buff *skb,
 	eseg->mss = attr.mss;
 
 	if (attr.ihs) {
-		if (unlikely(attr.hopbyhop)) {
-			struct ipv6hdr *h6;
-
-			/* remove the HBH header.
-			 * Layout: [Ethernet header][IPv6 header][HBH][TCP header]
-			 */
-			unsafe_memcpy(eseg->inline_hdr.start, skb->data,
-				      ETH_HLEN + sizeof(*h6),
-				      MLX5_UNSAFE_MEMCPY_DISCLAIMER);
-			h6 = (struct ipv6hdr *)((char *)eseg->inline_hdr.start + ETH_HLEN);
-			h6->nexthdr = IPPROTO_TCP;
-			/* Copy the TCP header after the IPv6 one */
-			unsafe_memcpy(h6 + 1,
-				      skb->data + ETH_HLEN + sizeof(*h6) +
-						  sizeof(struct hop_jumbo_hdr),
-				      tcp_hdrlen(skb),
-				      MLX5_UNSAFE_MEMCPY_DISCLAIMER);
-			/* Leave ipv6 payload_len set to 0, as LSO v2 specs request. */
-		} else {
-			unsafe_memcpy(eseg->inline_hdr.start, skb->data,
-				      attr.ihs,
-				      MLX5_UNSAFE_MEMCPY_DISCLAIMER);
-		}
+		unsafe_memcpy(eseg->inline_hdr.start, skb->data,
+			      attr.ihs,
+			      MLX5_UNSAFE_MEMCPY_DISCLAIMER);
 		eseg->inline_hdr.sz = cpu_to_be16(attr.ihs);
 		dseg += wqe_attr.ds_cnt_inl;
 	}
 
-	num_dma = mlx5e_txwqe_build_dsegs(sq, skb, skb->data + attr.ihs + attr.hopbyhop,
+	num_dma = mlx5e_txwqe_build_dsegs(sq, skb, skb->data + attr.ihs,
 					  attr.headlen, dseg);
 	if (unlikely(num_dma < 0))
 		goto err_drop;
-- 
2.52.0

[PATCH net-next v2 06/11] net/mlx4: Remove jumbo_remove step from TX path

[Alice Mikityanska]

From: Alice Mikityanska <alice@isovalent.com>

Now that the kernel doesn't insert HBH for BIG TCP IPv6 packets, remove
unnecessary steps from the mlx4 TX path, that used to check and remove
HBH.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
---
 drivers/net/ethernet/mellanox/mlx4/en_tx.c | 42 +++++-----------------
 1 file changed, 8 insertions(+), 34 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlx4/en_tx.c b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
index 87f35bcbeff8..c5d564e5a581 100644
--- a/drivers/net/ethernet/mellanox/mlx4/en_tx.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_tx.c
@@ -636,28 +636,20 @@ static int get_real_size(const struct sk_buff *skb,
 			 struct net_device *dev,
 			 int *lso_header_size,
 			 bool *inline_ok,
-			 void **pfrag,
-			 int *hopbyhop)
+			 void **pfrag)
 {
 	struct mlx4_en_priv *priv = netdev_priv(dev);
 	int real_size;
 
 	if (shinfo->gso_size) {
 		*inline_ok = false;
-		*hopbyhop = 0;
 		if (skb->encapsulation) {
 			*lso_header_size = skb_inner_tcp_all_headers(skb);
 		} else {
-			/* Detects large IPV6 TCP packets and prepares for removal of
-			 * HBH header that has been pushed by ip6_xmit(),
-			 * mainly so that tcpdump can dissect them.
-			 */
-			if (ipv6_has_hopopt_jumbo(skb))
-				*hopbyhop = sizeof(struct hop_jumbo_hdr);
 			*lso_header_size = skb_tcp_all_headers(skb);
 		}
 		real_size = CTRL_SIZE + shinfo->nr_frags * DS_SIZE +
-			ALIGN(*lso_header_size - *hopbyhop + 4, DS_SIZE);
+			ALIGN(*lso_header_size + 4, DS_SIZE);
 		if (unlikely(*lso_header_size != skb_headlen(skb))) {
 			/* We add a segment for the skb linear buffer only if
 			 * it contains data */
@@ -884,7 +876,6 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
 	int desc_size;
 	int real_size;
 	u32 index, bf_index;
-	struct ipv6hdr *h6;
 	__be32 op_own;
 	int lso_header_size;
 	void *fragptr = NULL;
@@ -893,7 +884,6 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
 	bool stop_queue;
 	bool inline_ok;
 	u8 data_offset;
-	int hopbyhop;
 	bool bf_ok;
 
 	tx_ind = skb_get_queue_mapping(skb);
@@ -903,7 +893,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
 		goto tx_drop;
 
 	real_size = get_real_size(skb, shinfo, dev, &lso_header_size,
-				  &inline_ok, &fragptr, &hopbyhop);
+				  &inline_ok, &fragptr);
 	if (unlikely(!real_size))
 		goto tx_drop_count;
 
@@ -956,7 +946,7 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
 		data = &tx_desc->data;
 		data_offset = offsetof(struct mlx4_en_tx_desc, data);
 	} else {
-		int lso_align = ALIGN(lso_header_size - hopbyhop + 4, DS_SIZE);
+		int lso_align = ALIGN(lso_header_size + 4, DS_SIZE);
 
 		data = (void *)&tx_desc->lso + lso_align;
 		data_offset = offsetof(struct mlx4_en_tx_desc, lso) + lso_align;
@@ -1021,31 +1011,15 @@ netdev_tx_t mlx4_en_xmit(struct sk_buff *skb, struct net_device *dev)
 			((ring->prod & ring->size) ?
 				cpu_to_be32(MLX4_EN_BIT_DESC_OWN) : 0);
 
-		lso_header_size -= hopbyhop;
 		/* Fill in the LSO prefix */
 		tx_desc->lso.mss_hdr_size = cpu_to_be32(
 			shinfo->gso_size << 16 | lso_header_size);
 
+		/* Copy headers;
+		 * note that we already verified that it is linear
+		 */
+		memcpy(tx_desc->lso.header, skb->data, lso_header_size);
 
-		if (unlikely(hopbyhop)) {
-			/* remove the HBH header.
-			 * Layout: [Ethernet header][IPv6 header][HBH][TCP header]
-			 */
-			memcpy(tx_desc->lso.header, skb->data, ETH_HLEN + sizeof(*h6));
-			h6 = (struct ipv6hdr *)((char *)tx_desc->lso.header + ETH_HLEN);
-			h6->nexthdr = IPPROTO_TCP;
-			/* Copy the TCP header after the IPv6 one */
-			memcpy(h6 + 1,
-			       skb->data + ETH_HLEN + sizeof(*h6) +
-					sizeof(struct hop_jumbo_hdr),
-			       tcp_hdrlen(skb));
-			/* Leave ipv6 payload_len set to 0, as LSO v2 specs request. */
-		} else {
-			/* Copy headers;
-			 * note that we already verified that it is linear
-			 */
-			memcpy(tx_desc->lso.header, skb->data, lso_header_size);
-		}
 		ring->tso_packets++;
 
 		i = shinfo->gso_segs;
-- 
2.52.0

[PATCH net-next v2 07/11] ice: Remove jumbo_remove step from TX path

[Alice Mikityanska]

From: Alice Mikityanska <alice@isovalent.com>

Now that the kernel doesn't insert HBH for BIG TCP IPv6 packets, remove
unnecessary steps from the ice TX path, that used to check and remove
HBH.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
---
 drivers/net/ethernet/intel/ice/ice_txrx.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c
index ad76768a4232..97576eab63ab 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
@@ -2156,9 +2156,6 @@ ice_xmit_frame_ring(struct sk_buff *skb, struct ice_tx_ring *tx_ring)
 
 	ice_trace(xmit_frame_ring, tx_ring, skb);
 
-	if (unlikely(ipv6_hopopt_jumbo_remove(skb)))
-		goto out_drop;
-
 	count = ice_xmit_desc_count(skb);
 	if (ice_chk_linearize(skb, count)) {
 		if (__skb_linearize(skb))
-- 
2.52.0

[PATCH net-next v2 08/11] bnxt_en: Remove jumbo_remove step from TX path

[Alice Mikityanska]

From: Alice Mikityanska <alice@isovalent.com>

Now that the kernel doesn't insert HBH for BIG TCP IPv6 packets, remove
unnecessary steps from the bnxt_en TX path, that used to check and
remove HBH.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 21 ---------------------
 1 file changed, 21 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index cb78614d4108..6a143dc6cb09 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -517,9 +517,6 @@ static netdev_tx_t bnxt_start_xmit(struct sk_buff *skb, struct net_device *dev)
 			return NETDEV_TX_BUSY;
 	}
 
-	if (unlikely(ipv6_hopopt_jumbo_remove(skb)))
-		goto tx_free;
-
 	length = skb->len;
 	len = skb_headlen(skb);
 	last_frag = skb_shinfo(skb)->nr_frags;
@@ -13852,7 +13849,6 @@ static bool bnxt_exthdr_check(struct bnxt *bp, struct sk_buff *skb, int nw_off,
 			      u8 **nextp)
 {
 	struct ipv6hdr *ip6h = (struct ipv6hdr *)(skb->data + nw_off);
-	struct hop_jumbo_hdr *jhdr;
 	int hdr_count = 0;
 	u8 *nexthdr;
 	int start;
@@ -13881,24 +13877,7 @@ static bool bnxt_exthdr_check(struct bnxt *bp, struct sk_buff *skb, int nw_off,
 		if (hdrlen > 64)
 			return false;
 
-		/* The ext header may be a hop-by-hop header inserted for
-		 * big TCP purposes. This will be removed before sending
-		 * from NIC, so do not count it.
-		 */
-		if (*nexthdr == NEXTHDR_HOP) {
-			if (likely(skb->len <= GRO_LEGACY_MAX_SIZE))
-				goto increment_hdr;
-
-			jhdr = (struct hop_jumbo_hdr *)hp;
-			if (jhdr->tlv_type != IPV6_TLV_JUMBO || jhdr->hdrlen != 0 ||
-			    jhdr->nexthdr != IPPROTO_TCP)
-				goto increment_hdr;
-
-			goto next_hdr;
-		}
-increment_hdr:
 		hdr_count++;
-next_hdr:
 		nexthdr = &hp->nexthdr;
 		start += hdrlen;
 	}
-- 
2.52.0

[PATCH net-next v2 09/11] gve: Remove jumbo_remove step from TX path

[Alice Mikityanska]

From: Alice Mikityanska <alice@isovalent.com>

Now that the kernel doesn't insert HBH for BIG TCP IPv6 packets, remove
unnecessary steps from the gve TX path, that used to check and remove
HBH.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
---
 drivers/net/ethernet/google/gve/gve_tx_dqo.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/ethernet/google/gve/gve_tx_dqo.c b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
index 40b89b3e5a31..28e85730f785 100644
--- a/drivers/net/ethernet/google/gve/gve_tx_dqo.c
+++ b/drivers/net/ethernet/google/gve/gve_tx_dqo.c
@@ -963,9 +963,6 @@ static int gve_try_tx_skb(struct gve_priv *priv, struct gve_tx_ring *tx,
 	int num_buffer_descs;
 	int total_num_descs;
 
-	if (skb_is_gso(skb) && unlikely(ipv6_hopopt_jumbo_remove(skb)))
-		goto drop;
-
 	if (tx->dqo.qpl) {
 		/* We do not need to verify the number of buffers used per
 		 * packet or per segment in case of TSO as with 2K size buffers
-- 
2.52.0

[PATCH net-next v2 10/11] net: mana: Remove jumbo_remove step from TX path

[Alice Mikityanska]

From: Alice Mikityanska <alice@isovalent.com>

Now that the kernel doesn't insert HBH for BIG TCP IPv6 packets, remove
unnecessary steps from the mana TX path, that used to check and remove
HBH.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
---
 drivers/net/ethernet/microsoft/mana/mana_en.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 1ad154f9db1a..443beac73a06 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -322,9 +322,6 @@ netdev_tx_t mana_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	if (skb_cow_head(skb, MANA_HEADROOM))
 		goto tx_drop_count;
 
-	if (unlikely(ipv6_hopopt_jumbo_remove(skb)))
-		goto tx_drop_count;
-
 	txq = &apc->tx_qp[txq_idx].txq;
 	gdma_sq = txq->gdma_sq;
 	cq = &apc->tx_qp[txq_idx].tx_cq;
-- 
2.52.0

[PATCH net-next v2 11/11] net/ipv6: Remove HBH helpers

[Alice Mikityanska]

From: Alice Mikityanska <alice@isovalent.com>

Now that the HBH jumbo helpers are not used by any driver or GSO, remove
them altogether.

Signed-off-by: Alice Mikityanska <alice@isovalent.com>
---
 include/net/ipv6.h | 77 ----------------------------------------------
 1 file changed, 77 deletions(-)

diff --git a/include/net/ipv6.h b/include/net/ipv6.h
index f65bcef57d80..e697e5fd5fc1 100644
--- a/include/net/ipv6.h
+++ b/include/net/ipv6.h
@@ -149,17 +149,6 @@ struct frag_hdr {
 	__be32	identification;
 };
 
-/*
- * Jumbo payload option, as described in RFC 2675 2.
- */
-struct hop_jumbo_hdr {
-	u8	nexthdr;
-	u8	hdrlen;
-	u8	tlv_type;	/* IPV6_TLV_JUMBO, 0xC2 */
-	u8	tlv_len;	/* 4 */
-	__be32	jumbo_payload_len;
-};
-
 #define	IP6_MF		0x0001
 #define	IP6_OFFSET	0xFFF8
 
@@ -462,72 +451,6 @@ bool ipv6_opt_accepted(const struct sock *sk, const struct sk_buff *skb,
 struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
 					   struct ipv6_txoptions *opt);
 
-/* This helper is specialized for BIG TCP needs.
- * It assumes the hop_jumbo_hdr will immediately follow the IPV6 header.
- * It assumes headers are already in skb->head.
- * Returns: 0, or IPPROTO_TCP if a BIG TCP packet is there.
- */
-static inline int ipv6_has_hopopt_jumbo(const struct sk_buff *skb)
-{
-	const struct hop_jumbo_hdr *jhdr;
-	const struct ipv6hdr *nhdr;
-
-	if (likely(skb->len <= GRO_LEGACY_MAX_SIZE))
-		return 0;
-
-	if (skb->protocol != htons(ETH_P_IPV6))
-		return 0;
-
-	if (skb_network_offset(skb) +
-	    sizeof(struct ipv6hdr) +
-	    sizeof(struct hop_jumbo_hdr) > skb_headlen(skb))
-		return 0;
-
-	nhdr = ipv6_hdr(skb);
-
-	if (nhdr->nexthdr != NEXTHDR_HOP)
-		return 0;
-
-	jhdr = (const struct hop_jumbo_hdr *) (nhdr + 1);
-	if (jhdr->tlv_type != IPV6_TLV_JUMBO || jhdr->hdrlen != 0 ||
-	    jhdr->nexthdr != IPPROTO_TCP)
-		return 0;
-	return jhdr->nexthdr;
-}
-
-/* Return 0 if HBH header is successfully removed
- * Or if HBH removal is unnecessary (packet is not big TCP)
- * Return error to indicate dropping the packet
- */
-static inline int ipv6_hopopt_jumbo_remove(struct sk_buff *skb)
-{
-	const int hophdr_len = sizeof(struct hop_jumbo_hdr);
-	int nexthdr = ipv6_has_hopopt_jumbo(skb);
-	struct ipv6hdr *h6;
-
-	if (!nexthdr)
-		return 0;
-
-	if (skb_cow_head(skb, 0))
-		return -1;
-
-	/* Remove the HBH header.
-	 * Layout: [Ethernet header][IPv6 header][HBH][L4 Header]
-	 */
-	memmove(skb_mac_header(skb) + hophdr_len, skb_mac_header(skb),
-		skb_network_header(skb) - skb_mac_header(skb) +
-		sizeof(struct ipv6hdr));
-
-	__skb_pull(skb, hophdr_len);
-	skb->network_header += hophdr_len;
-	skb->mac_header += hophdr_len;
-
-	h6 = ipv6_hdr(skb);
-	h6->nexthdr = nexthdr;
-
-	return 0;
-}
-
 static inline bool ipv6_accept_ra(const struct inet6_dev *idev)
 {
 	s32 accept_ra = READ_ONCE(idev->cnf.accept_ra);
-- 
2.52.0

Re: [PATCH net-next v2 00/11] BIG TCP without HBH in IPv6

[Paolo Abeni]

On 1/13/26 10:26 PM, Alice Mikityanska wrote:
> From: Alice Mikityanska <alice@isovalent.com>
> 
> This series is part 1 of v2 of "BIG TCP for UDP tunnels". Due to the
> number of patches, I'm splitting it into two logical parts:
> 
> * Remove hop-by-hop header for BIG TCP IPv6 to align with BIG TCP IPv4.
> * Fix up things that prevent BIG TCP from working with UDP tunnels.
> 
> The current BIG TCP IPv6 code inserts a hop-by-hop extension header with
> 32-bit length of the packet. When the packet is encapsulated, and either
> the outer or the inner protocol is IPv6, or both are IPv6, there will be
> 1 or 2 HBH headers that need to be dealt with. The issues that arise:
> 
> 1. The drivers don't strip it, and they'd all need to know the structure
> of each tunnel protocol in order to strip it correctly, also taking into
> account all combinations of IPv4/IPv6 inner/outer protocols.
> 
> 2. Even if (1) is implemented, it would be an additional performance
> penalty per aggregated packet.
> 
> 3. The skb_gso_validate_network_len check is skipped in
> ip6_finish_output_gso when IP6SKB_FAKEJUMBO is set, but it seems that it
> would make sense to do the actual validation, just taking into account
> the length of the HBH header. When the support for tunnels is added, it
> becomes trickier, because there may be one or two HBH headers, depending
> on whether it's IPv6 in IPv6 or not.
> 
> At the same time, having an HBH header to store the 32-bit length is not
> strictly necessary, as BIG TCP IPv4 doesn't do anything like this and
> just restores the length from skb->len. The same thing can be done for
> BIG TCP IPv6. Removing HBH from BIG TCP would allow to simplify the
> implementation significantly, and align it with BIG TCP IPv4, which has
> been a long-standing goal.
> 
> v1: https://lore.kernel.org/netdev/20250923134742.1399800-1-maxtram95@gmail.com/
> 
> v2 changes:
> 
> Split the series into two parts. Address the review comments in part 2
> (details follow with part 2).
> 
> P.S. Author had her name changed since v1; it's the same person.

I went through the series as careful as I could and it looks good to me
- actually it cleans up the GRO/GSO nicely.

Acked-by: Paolo Abeni <pabeni@redhat.com>

Still I think we need the tcpdump part being available before merging
the code; AFAICS the related PR has moved forward a bit since v1 here:

https://github.com/the-tcpdump-group/tcpdump/pull/1329
https://github.com/the-tcpdump-group/tcpdump/pull/1396

But it's not ready yet.

/P