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(-)
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>
---
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 <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, struct net_device *dev,
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_net_ops = {
.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);
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 *head, struct sk_buff *skb)
return pp;
}
+EXPORT_INDIRECT_CALLABLE(inet_gro_receive);
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);
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_receive(struct list_head *head,
return pp;
}
+EXPORT_INDIRECT_CALLABLE(ipv6_gro_receive);
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);
static int sit_gro_complete(struct sk_buff *skb, int nhoff)
{
--
2.50.1Felix Fietkau wrote:
> 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>
> ---
> 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 <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, struct net_device *dev,
> 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_net_ops = {
> .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)
> +{
I don't think this will be called for PPPoE over GRE packets,
since gre_gso_segment skips everything up to the network header.
> + 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);
> 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 *head, struct sk_buff *skb)
>
> return pp;
> }
> +EXPORT_INDIRECT_CALLABLE(inet_gro_receive);
>
> 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);
>
> 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_receive(struct list_head *head,
>
> return pp;
> }
> +EXPORT_INDIRECT_CALLABLE(ipv6_gro_receive);
>
> 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);
>
> static int sit_gro_complete(struct sk_buff *skb, int nhoff)
> {
On 14.08.25 16:30, Richard Gobert wrote:
> Felix Fietkau wrote:
>> 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>
>> ---
>> 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
>> +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)
>> +{
>
> I don't think this will be called for PPPoE over GRE packets,
> since gre_gso_segment skips everything up to the network header.
What's a good solution to this issue? Use the outer network header
instead of the inner one when the protocol is PPPoE?
- Felix
Felix Fietkau wrote:
> On 14.08.25 16:30, Richard Gobert wrote:
>> Felix Fietkau wrote:
>>> 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>
>>> ---
>>> 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
>>> +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)
>>> +{
>>
>> I don't think this will be called for PPPoE over GRE packets,
>> since gre_gso_segment skips everything up to the network header.
>
> What's a good solution to this issue? Use the outer network header instead of the inner one when the protocol is PPPoE?
>
> - Felix
I don't really have a good solution for this. You could explicitly check
if the protocol is PPPoE in gre_gso_segment, but that wouldn't be very
elegant or future-proof.
I think setting skb->inner_network_header in pppoe_gro_complete
(while not resetting it in inet_gro_complete) wouldn't work since other
functions assume that skb->inner_network_header is an IP header.
On 8/18/25 1:22 PM, Richard Gobert wrote: > Felix Fietkau wrote: >> On 14.08.25 16:30, Richard Gobert wrote: >>> I don't think this will be called for PPPoE over GRE packets, >>> since gre_gso_segment skips everything up to the network header. >> >> What's a good solution to this issue? Use the outer network header instead of the inner one when the protocol is PPPoE? >> >> - Felix > > I don't really have a good solution for this. You could explicitly check > if the protocol is PPPoE in gre_gso_segment, but that wouldn't be very > elegant or future-proof. > > I think setting skb->inner_network_header in pppoe_gro_complete > (while not resetting it in inet_gro_complete) wouldn't work since other > functions assume that skb->inner_network_header is an IP header. Is PPPoE over GRE really a thing? IOW do we need to care at the GRO level? FTR, my biased answers are "no" and "no" ;) /P
On 8/11/25 11:57 AM, Felix Fietkau wrote:
> @@ -1173,6 +1174,161 @@ static struct pernet_operations pppoe_net_ops = {
> .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));
I'm sorry for the late feedback.
I see that the pppoe rcv() code ignores the type and ver fields, but I
guess it should be better to match them here, to ensure that the
segmented packet sequence matches the pre-aggregation one.
You could cast the phdr* to u32* and compare such integer.
> +}
> +
> +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;
> + }
> +
Minor nit: unneeded empty line above
> +}
> +
> +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;
What about filtering for phdr->code == 0 (session data) to avoid useless
late processing?
Thanks,
Paolo
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