From nobody Sun Oct 5 01:49:57 2025 Received: from nbd.name (nbd.name [46.4.11.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3071C1BD035; Mon, 11 Aug 2025 10:25:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=46.4.11.11 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754907954; cv=none; b=c6Q+psRjsEkaHrdrVjVNzHYcZo3btyoZok852g4j1ismhShLFJHjnQTmGE5SAM4NVQeoBj5xxd5u5mg1Lai2fYdRV8VHrZRcE6mqXOGQRcdnp7YvF5ZpyrehLHW9AQzcMzrM3JmmzVunCn74qNs7NKpnCwTiW6Vu5qcsdKvpDLs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754907954; c=relaxed/simple; bh=WUFJaClt5A1A0E/z56Bv2phNlvk64lAEZVnpfKHjVH0=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=s3clJDCi1sU+u9hzsXK9oAqZ4HUV+UqaRVtVLuK88habv9yN7Ppg9BYFvQtuZwVxrm+1KhIqzwcA6zbmey9a67XJBiX74PnHYvr3yup/dItpS1/U7NtBmVL3mDms3h0etc1K/uM2uZrwE/NnuRGrmjGURPiOPuOmqcpHh5+FyPY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=nbd.name; spf=none smtp.mailfrom=nbd.name; dkim=pass (1024-bit key) header.d=nbd.name header.i=@nbd.name header.b=KNL4ECDi; arc=none smtp.client-ip=46.4.11.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=nbd.name Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=nbd.name Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=nbd.name header.i=@nbd.name header.b="KNL4ECDi" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=nbd.name; s=20160729; h=Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject: Cc:To:From:Sender:Reply-To:Content-Type:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=rUXBcZclaa5p7dx86NOsbKhNhMlRIII02pORjXX5jDo=; b=KNL4ECDin1/0F6RT/nrl7AgsSR OHZ3p/zt/j2QEm+GQQoITnDbnQLiefa1/2LcOO35Bdf92of6FRrto1m2jW3+apLVAG5MWweC3mAbQ 83o/RNnxWs6XbiejmtKFjpigBymQA5L008oNW0oh/toxZAeDNeqV94NiAGV2uPlJo/9o=; Received: from p5b206816.dip0.t-ipconnect.de ([91.32.104.22] helo=localhost.localdomain) by ds12 with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (Exim 4.96) (envelope-from ) id 1ulPHb-008fA3-1P; Mon, 11 Aug 2025 11:57:35 +0200 From: Felix Fietkau To: netdev@vger.kernel.org, Michal Ostrowski , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , David Ahern , Simon Horman Cc: linux-kernel@vger.kernel.org Subject: [PATCH net-next v3] net: pppoe: implement GRO/GSO support Date: Mon, 11 Aug 2025 11:57:33 +0200 Message-ID: <20250811095734.71019-1-nbd@nbd.name> X-Mailer: git-send-email 2.50.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Only handles packets where the pppoe header length field matches the exact packet length. Significantly improves rx throughput. When running NAT traffic through a MediaTek MT7621 devices from a host behind PPPoE to a host directly connected via ethernet, the TCP throughput that the device is able to handle improves from ~130 Mbit/s to ~630 Mbit/s, using fraglist GRO. Signed-off-by: Felix Fietkau --- v2: fix compile error v3: - increase priority value - implement GSO support - use INDIRECT_CALL_INET - update pppoe length field - remove unnecessary network_offsets update drivers/net/ppp/pppoe.c | 160 +++++++++++++++++++++++++++++++++++++++- net/ipv4/af_inet.c | 2 + net/ipv6/ip6_offload.c | 2 + 3 files changed, 163 insertions(+), 1 deletion(-) diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c index 410effa42ade..a8d8eb870bce 100644 --- a/drivers/net/ppp/pppoe.c +++ b/drivers/net/ppp/pppoe.c @@ -77,6 +77,7 @@ #include #include #include +#include =20 #include =20 @@ -435,7 +436,7 @@ static int pppoe_rcv(struct sk_buff *skb, struct net_de= vice *dev, if (skb->len < len) goto drop; =20 - if (pskb_trim_rcsum(skb, len)) + if (!skb_is_gso(skb) && pskb_trim_rcsum(skb, len)) goto drop; =20 ph =3D pppoe_hdr(skb); @@ -1173,6 +1174,161 @@ static struct pernet_operations pppoe_net_ops =3D { .size =3D sizeof(struct pppoe_net), }; =20 +static u16 +compare_pppoe_header(struct pppoe_hdr *phdr, struct pppoe_hdr *phdr2) +{ + return (__force __u16)((phdr->sid ^ phdr2->sid) | + (phdr->tag[0].tag_type ^ phdr2->tag[0].tag_type)); +} + +static __be16 pppoe_hdr_proto(struct pppoe_hdr *phdr) +{ + switch (phdr->tag[0].tag_type) { + case cpu_to_be16(PPP_IP): + return cpu_to_be16(ETH_P_IP); + case cpu_to_be16(PPP_IPV6): + return cpu_to_be16(ETH_P_IPV6); + default: + return 0; + } + +} + +static struct sk_buff *pppoe_gro_receive(struct list_head *head, + struct sk_buff *skb) +{ + const struct packet_offload *ptype; + unsigned int hlen, off_pppoe; + struct sk_buff *pp =3D NULL; + struct pppoe_hdr *phdr; + struct sk_buff *p; + int flush =3D 1; + __be16 type; + + off_pppoe =3D skb_gro_offset(skb); + hlen =3D off_pppoe + sizeof(*phdr); + phdr =3D skb_gro_header(skb, hlen + 2, off_pppoe); + if (unlikely(!phdr)) + goto out; + + /* ignore packets with padding or invalid length */ + if (skb_gro_len(skb) !=3D be16_to_cpu(phdr->length) + hlen) + goto out; + + type =3D pppoe_hdr_proto(phdr); + if (!type) + goto out; + + ptype =3D gro_find_receive_by_type(type); + if (!ptype) + goto out; + + flush =3D 0; + + list_for_each_entry(p, head, list) { + struct pppoe_hdr *phdr2; + + if (!NAPI_GRO_CB(p)->same_flow) + continue; + + phdr2 =3D (struct pppoe_hdr *)(p->data + off_pppoe); + if (compare_pppoe_header(phdr, phdr2)) + NAPI_GRO_CB(p)->same_flow =3D 0; + } + + skb_gro_pull(skb, sizeof(*phdr) + 2); + skb_gro_postpull_rcsum(skb, phdr, sizeof(*phdr) + 2); + + pp =3D indirect_call_gro_receive_inet(ptype->callbacks.gro_receive, + ipv6_gro_receive, inet_gro_receive, + head, skb); + +out: + skb_gro_flush_final(skb, pp, flush); + + return pp; +} + +static int pppoe_gro_complete(struct sk_buff *skb, int nhoff) +{ + struct pppoe_hdr *phdr =3D (struct pppoe_hdr *)(skb->data + nhoff); + __be16 type =3D pppoe_hdr_proto(phdr); + struct packet_offload *ptype; + int len, err; + + ptype =3D gro_find_complete_by_type(type); + if (!ptype) + return -ENOENT; + + err =3D INDIRECT_CALL_INET(ptype->callbacks.gro_complete, + ipv6_gro_complete, inet_gro_complete, + skb, nhoff + sizeof(*phdr) + 2); + if (err) + return err; + + len =3D skb->len - (nhoff + sizeof(*phdr)); + phdr->length =3D cpu_to_be16(len); + + return 0; +} + +static struct sk_buff *pppoe_gso_segment(struct sk_buff *skb, + netdev_features_t features) +{ + unsigned int pppoe_hlen =3D sizeof(struct pppoe_hdr) + 2; + struct sk_buff *segs =3D ERR_PTR(-EINVAL); + u16 mac_offset =3D skb->mac_header; + struct packet_offload *ptype; + u16 mac_len =3D skb->mac_len; + struct pppoe_hdr *phdr; + __be16 orig_type, type; + int len, nhoff; + + skb_reset_network_header(skb); + nhoff =3D skb_network_header(skb) - skb_mac_header(skb); + + if (unlikely(!pskb_may_pull(skb, pppoe_hlen))) + goto out; + + phdr =3D (struct pppoe_hdr *)skb_network_header(skb); + type =3D pppoe_hdr_proto(phdr); + ptype =3D gro_find_complete_by_type(type); + if (!ptype) + goto out; + + orig_type =3D skb->protocol; + __skb_pull(skb, pppoe_hlen); + segs =3D ptype->callbacks.gso_segment(skb, features); + if (IS_ERR_OR_NULL(segs)) { + skb_gso_error_unwind(skb, orig_type, pppoe_hlen, mac_offset, + mac_len); + goto out; + } + + skb =3D segs; + do { + phdr =3D (struct pppoe_hdr *)(skb_mac_header(skb) + nhoff); + len =3D skb->len - (nhoff + sizeof(*phdr)); + phdr->length =3D cpu_to_be16(len); + skb->network_header =3D (u8 *)phdr - skb->head; + skb->protocol =3D orig_type; + skb_reset_mac_len(skb); + } while ((skb =3D skb->next)); + +out: + return segs; +} + +static struct packet_offload pppoe_packet_offload __read_mostly =3D { + .type =3D cpu_to_be16(ETH_P_PPP_SES), + .priority =3D 20, + .callbacks =3D { + .gro_receive =3D pppoe_gro_receive, + .gro_complete =3D pppoe_gro_complete, + .gso_segment =3D pppoe_gso_segment, + }, +}; + static int __init pppoe_init(void) { int err; @@ -1189,6 +1345,7 @@ static int __init pppoe_init(void) if (err) goto out_unregister_pppoe_proto; =20 + dev_add_offload(&pppoe_packet_offload); dev_add_pack(&pppoes_ptype); dev_add_pack(&pppoed_ptype); register_netdevice_notifier(&pppoe_notifier); @@ -1208,6 +1365,7 @@ static void __exit pppoe_exit(void) unregister_netdevice_notifier(&pppoe_notifier); dev_remove_pack(&pppoed_ptype); dev_remove_pack(&pppoes_ptype); + dev_remove_offload(&pppoe_packet_offload); unregister_pppox_proto(PX_PROTO_OE); proto_unregister(&pppoe_sk_proto); unregister_pernet_device(&pppoe_net_ops); diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 76e38092cd8a..0480a6d4f203 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1533,6 +1533,7 @@ struct sk_buff *inet_gro_receive(struct list_head *he= ad, struct sk_buff *skb) =20 return pp; } +EXPORT_INDIRECT_CALLABLE(inet_gro_receive); =20 static struct sk_buff *ipip_gro_receive(struct list_head *head, struct sk_buff *skb) @@ -1618,6 +1619,7 @@ int inet_gro_complete(struct sk_buff *skb, int nhoff) out: return err; } +EXPORT_INDIRECT_CALLABLE(inet_gro_complete); =20 static int ipip_gro_complete(struct sk_buff *skb, int nhoff) { diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c index fce91183797a..9e3640b018a4 100644 --- a/net/ipv6/ip6_offload.c +++ b/net/ipv6/ip6_offload.c @@ -306,6 +306,7 @@ INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receiv= e(struct list_head *head, =20 return pp; } +EXPORT_INDIRECT_CALLABLE(ipv6_gro_receive); =20 static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head, struct sk_buff *skb) @@ -388,6 +389,7 @@ INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk= _buff *skb, int nhoff) out: return err; } +EXPORT_INDIRECT_CALLABLE(ipv6_gro_complete); =20 static int sit_gro_complete(struct sk_buff *skb, int nhoff) { --=20 2.50.1