Files
openwrt-R7800-nss/target/linux/generic/pending-6.12/650-net-pppoe-implement-GRO-support.patch
Felix Fietkau 991dd403d3 kernel: improve pppoe performance
- drop tx qdisc
- implement rx GRO support

Signed-off-by: Felix Fietkau <nbd@nbd.name>
2025-08-03 06:22:59 +02:00

249 lines
6.3 KiB
Diff

From: Felix Fietkau <nbd@nbd.name>
Date: Tue, 15 Jul 2025 12:37:45 +0200
Subject: [PATCH] net: pppoe: implement GRO support
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 <nbd@nbd.name>
---
--- a/drivers/net/ppp/pppoe.c
+++ b/drivers/net/ppp/pppoe.c
@@ -77,6 +77,7 @@
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/sock.h>
+#include <net/gro.h>
#include <linux/uaccess.h>
@@ -435,7 +436,7 @@ static int pppoe_rcv(struct sk_buff *skb
if (skb->len < len)
goto drop;
- if (pskb_trim_rcsum(skb, len))
+ if (!skb_is_gso(skb) && pskb_trim_rcsum(skb, len))
goto drop;
ph = pppoe_hdr(skb);
@@ -1173,6 +1174,161 @@ static struct pernet_operations pppoe_ne
.size = sizeof(struct pppoe_net),
};
+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 = NULL;
+ struct pppoe_hdr *phdr;
+ struct sk_buff *p;
+ int flush = 1;
+ __be16 type;
+
+ off_pppoe = skb_gro_offset(skb);
+ hlen = off_pppoe + sizeof(*phdr);
+ phdr = 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) != be16_to_cpu(phdr->length) + hlen)
+ goto out;
+
+ type = pppoe_hdr_proto(phdr);
+ if (!type)
+ goto out;
+
+ ptype = gro_find_receive_by_type(type);
+ if (!ptype)
+ goto out;
+
+ flush = 0;
+
+ list_for_each_entry(p, head, list) {
+ struct pppoe_hdr *phdr2;
+
+ if (!NAPI_GRO_CB(p)->same_flow)
+ continue;
+
+ phdr2 = (struct pppoe_hdr *)(p->data + off_pppoe);
+ if (compare_pppoe_header(phdr, phdr2))
+ NAPI_GRO_CB(p)->same_flow = 0;
+ }
+
+ skb_gro_pull(skb, sizeof(*phdr) + 2);
+ skb_gro_postpull_rcsum(skb, phdr, sizeof(*phdr) + 2);
+
+ pp = 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 = (struct pppoe_hdr *)(skb->data + nhoff);
+ __be16 type = pppoe_hdr_proto(phdr);
+ struct packet_offload *ptype;
+ int len, err;
+
+ ptype = gro_find_complete_by_type(type);
+ if (!ptype)
+ return -ENOENT;
+
+ err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete,
+ ipv6_gro_complete, inet_gro_complete,
+ skb, nhoff + sizeof(*phdr) + 2);
+ if (err)
+ return err;
+
+ len = skb->len - (nhoff + sizeof(*phdr));
+ phdr->length = 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 = sizeof(struct pppoe_hdr) + 2;
+ struct sk_buff *segs = ERR_PTR(-EINVAL);
+ u16 mac_offset = skb->mac_header;
+ struct packet_offload *ptype;
+ u16 mac_len = skb->mac_len;
+ struct pppoe_hdr *phdr;
+ __be16 orig_type, type;
+ int len, nhoff;
+
+ skb_reset_network_header(skb);
+ nhoff = skb_network_header(skb) - skb_mac_header(skb);
+
+ if (unlikely(!pskb_may_pull(skb, pppoe_hlen)))
+ goto out;
+
+ phdr = (struct pppoe_hdr *)skb_network_header(skb);
+ type = pppoe_hdr_proto(phdr);
+ ptype = gro_find_complete_by_type(type);
+ if (!ptype)
+ goto out;
+
+ orig_type = skb->protocol;
+ __skb_pull(skb, pppoe_hlen);
+ segs = 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 = segs;
+ do {
+ phdr = (struct pppoe_hdr *)(skb_mac_header(skb) + nhoff);
+ len = skb->len - (nhoff + sizeof(*phdr));
+ phdr->length = cpu_to_be16(len);
+ skb->network_header = (u8 *)phdr - skb->head;
+ skb->protocol = orig_type;
+ skb_reset_mac_len(skb);
+ } while ((skb = skb->next));
+
+out:
+ return segs;
+}
+
+static struct packet_offload pppoe_packet_offload __read_mostly = {
+ .type = cpu_to_be16(ETH_P_PPP_SES),
+ .priority = 20,
+ .callbacks = {
+ .gro_receive = pppoe_gro_receive,
+ .gro_complete = pppoe_gro_complete,
+ .gso_segment = 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;
+ 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);
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1546,6 +1546,7 @@ out:
return pp;
}
+EXPORT_INDIRECT_CALLABLE(inet_gro_receive);
static struct sk_buff *ipip_gro_receive(struct list_head *head,
struct sk_buff *skb)
@@ -1631,6 +1632,7 @@ int inet_gro_complete(struct sk_buff *sk
out:
return err;
}
+EXPORT_INDIRECT_CALLABLE(inet_gro_complete);
static int ipip_gro_complete(struct sk_buff *skb, int nhoff)
{
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -304,6 +304,7 @@ out:
return pp;
}
+EXPORT_INDIRECT_CALLABLE(ipv6_gro_receive);
static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head,
struct sk_buff *skb)
@@ -386,6 +387,7 @@ INDIRECT_CALLABLE_SCOPE int ipv6_gro_com
out:
return err;
}
+EXPORT_INDIRECT_CALLABLE(ipv6_gro_complete);
static int sit_gro_complete(struct sk_buff *skb, int nhoff)
{