mirror
/
openwrt
mirror of https://git.openwrt.org/openwrt/openwrt.git
1
0
Fork 0
Code Releases Activity
openwrt/target/linux/generic/pending-6.6/680-net-add-TCP-fraglist-GR...

511 lines
13 KiB
Diff
Raw Blame History

From: Felix Fietkau <nbd@nbd.name>
Date: Tue, 23 Apr 2024 11:23:03 +0200
Subject: [PATCH] net: add TCP fraglist GRO support
When forwarding TCP after GRO, software segmentation is very expensive,
especially when the checksum needs to be recalculated.
One case where that's currently unavoidable is when routing packets over
PPPoE. Performance improves significantly when using fraglist GRO
implemented in the same way as for UDP.
Here's a measurement of running 2 TCP streams through a MediaTek MT7622
device (2-core Cortex-A53), which runs NAT with flow offload enabled from
one ethernet port to PPPoE on another ethernet port + cake qdisc set to
1Gbps.
rx-gro-list off: 630 Mbit/s, CPU 35% idle
rx-gro-list on: 770 Mbit/s, CPU 40% idle
Signe-off-by: Felix Fietkau <nbd@nbd.name>
---
--- a/include/net/gro.h
+++ b/include/net/gro.h
@@ -430,6 +430,7 @@ static inline __wsum ip6_gro_compute_pse
}
int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb);
+int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb);
/* Pass the currently batched GRO_NORMAL SKBs up to the stack. */
static inline void gro_normal_list(struct napi_struct *napi)
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2082,7 +2082,10 @@ void tcp_v4_destroy_sock(struct sock *sk
struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
netdev_features_t features);
-struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb);
+struct tcphdr *tcp_gro_pull_header(struct sk_buff *skb);
+struct sk_buff *tcp_gro_lookup(struct list_head *head, struct tcphdr *th);
+struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb,
+ struct tcphdr *th);
INDIRECT_CALLABLE_DECLARE(int tcp4_gro_complete(struct sk_buff *skb, int thoff));
INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp4_gro_receive(struct list_head *head, struct sk_buff *skb));
INDIRECT_CALLABLE_DECLARE(int tcp6_gro_complete(struct sk_buff *skb, int thoff));
--- a/net/core/gro.c
+++ b/net/core/gro.c
@@ -233,6 +233,33 @@ done:
return 0;
}
+int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb)
+{
+ if (unlikely(p->len + skb->len >= 65536))
+ return -E2BIG;
+
+ if (NAPI_GRO_CB(p)->last == p)
+ skb_shinfo(p)->frag_list = skb;
+ else
+ NAPI_GRO_CB(p)->last->next = skb;
+
+ skb_pull(skb, skb_gro_offset(skb));
+
+ NAPI_GRO_CB(p)->last = skb;
+ NAPI_GRO_CB(p)->count++;
+ p->data_len += skb->len;
+
+ /* sk ownership - if any - completely transferred to the aggregated packet */
+ skb->destructor = NULL;
+ skb->sk = NULL;
+ p->truesize += skb->truesize;
+ p->len += skb->len;
+
+ NAPI_GRO_CB(skb)->same_flow = 1;
+
+ return 0;
+}
+
static void napi_gro_complete(struct napi_struct *napi, struct sk_buff *skb)
{
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -28,6 +28,68 @@ static void tcp_gso_tstamp(struct sk_buf
}
}
+static void __tcpv4_gso_segment_csum(struct sk_buff *seg,
+ __be32 *oldip, __be32 *newip,
+ __be16 *oldport, __be16 *newport)
+{
+ struct tcphdr *th;
+ struct iphdr *iph;
+
+ if (*oldip == *newip && *oldport == *newport)
+ return;
+
+ th = tcp_hdr(seg);
+ iph = ip_hdr(seg);
+
+ inet_proto_csum_replace4(&th->check, seg, *oldip, *newip, true);
+ inet_proto_csum_replace2(&th->check, seg, *oldport, *newport, false);
+ *oldport = *newport;
+
+ csum_replace4(&iph->check, *oldip, *newip);
+ *oldip = *newip;
+}
+
+static struct sk_buff *__tcpv4_gso_segment_list_csum(struct sk_buff *segs)
+{
+ struct sk_buff *seg;
+ struct tcphdr *th, *th2;
+ struct iphdr *iph, *iph2;
+
+ seg = segs;
+ th = tcp_hdr(seg);
+ iph = ip_hdr(seg);
+ th2 = tcp_hdr(seg->next);
+ iph2 = ip_hdr(seg->next);
+
+ if (!(*(u32 *)&th->source ^ *(u32 *)&th2->source) &&
+ iph->daddr == iph2->daddr && iph->saddr == iph2->saddr)
+ return segs;
+
+ while ((seg = seg->next)) {
+ th2 = tcp_hdr(seg);
+ iph2 = ip_hdr(seg);
+
+ __tcpv4_gso_segment_csum(seg,
+ &iph2->saddr, &iph->saddr,
+ &th2->source, &th->source);
+ __tcpv4_gso_segment_csum(seg,
+ &iph2->daddr, &iph->daddr,
+ &th2->dest, &th->dest);
+ }
+
+ return segs;
+}
+
+static struct sk_buff *__tcp4_gso_segment_list(struct sk_buff *skb,
+ netdev_features_t features)
+{
+ skb = skb_segment_list(skb, features, skb_mac_header_len(skb));
+ if (IS_ERR(skb))
+ return skb;
+
+ return __tcpv4_gso_segment_list_csum(skb);
+}
+
static struct sk_buff *tcp4_gso_segment(struct sk_buff *skb,
netdev_features_t features)
{
@@ -37,6 +99,9 @@ static struct sk_buff *tcp4_gso_segment(
if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
return ERR_PTR(-EINVAL);
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST)
+ return __tcp4_gso_segment_list(skb, features);
+
if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
const struct iphdr *iph = ip_hdr(skb);
struct tcphdr *th = tcp_hdr(skb);
@@ -178,61 +243,76 @@ out:
return segs;
}
-struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb)
+struct sk_buff *tcp_gro_lookup(struct list_head *head, struct tcphdr *th)
{
- struct sk_buff *pp = NULL;
+ struct tcphdr *th2;
struct sk_buff *p;
+
+ list_for_each_entry(p, head, list) {
+ if (!NAPI_GRO_CB(p)->same_flow)
+ continue;
+
+ th2 = tcp_hdr(p);
+ if (*(u32 *)&th->source ^ *(u32 *)&th2->source) {
+ NAPI_GRO_CB(p)->same_flow = 0;
+ continue;
+ }
+
+ return p;
+ }
+
+ return NULL;
+}
+
+struct tcphdr *tcp_gro_pull_header(struct sk_buff *skb)
+{
+ unsigned int thlen, hlen, off;
struct tcphdr *th;
- struct tcphdr *th2;
- unsigned int len;
- unsigned int thlen;
- __be32 flags;
- unsigned int mss = 1;
- unsigned int hlen;
- unsigned int off;
- int flush = 1;
- int i;
off = skb_gro_offset(skb);
hlen = off + sizeof(*th);
th = skb_gro_header(skb, hlen, off);
if (unlikely(!th))
- goto out;
+ return NULL;
thlen = th->doff * 4;
if (thlen < sizeof(*th))
- goto out;
+ return NULL;
hlen = off + thlen;
if (skb_gro_header_hard(skb, hlen)) {
th = skb_gro_header_slow(skb, hlen, off);
if (unlikely(!th))
- goto out;
+ return NULL;
}
skb_gro_pull(skb, thlen);
- len = skb_gro_len(skb);
- flags = tcp_flag_word(th);
-
- list_for_each_entry(p, head, list) {
- if (!NAPI_GRO_CB(p)->same_flow)
- continue;
+ return th;
+}
- th2 = tcp_hdr(p);
+struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb,
+ struct tcphdr *th)
+{
+ unsigned int thlen = th->doff * 4;
+ struct sk_buff *pp = NULL;
+ struct sk_buff *p;
+ struct tcphdr *th2;
+ unsigned int len;
+ __be32 flags;
+ unsigned int mss = 1;
+ int flush = 1;
+ int i;
- if (*(u32 *)&th->source ^ *(u32 *)&th2->source) {
- NAPI_GRO_CB(p)->same_flow = 0;
- continue;
- }
+ len = skb_gro_len(skb);
+ flags = tcp_flag_word(th);
- goto found;
- }
- p = NULL;
- goto out_check_final;
+ p = tcp_gro_lookup(head, th);
+ if (!p)
+ goto out_check_final;
-found:
/* Include the IP ID check below from the inner most IP hdr */
+ th2 = tcp_hdr(p);
flush = NAPI_GRO_CB(p)->flush;
flush |= (__force int)(flags & TCP_FLAG_CWR);
flush |= (__force int)((flags ^ tcp_flag_word(th2)) &
@@ -269,6 +349,19 @@ found:
flush |= p->decrypted ^ skb->decrypted;
#endif
+ if (NAPI_GRO_CB(p)->is_flist) {
+ flush |= (__force int)(flags ^ tcp_flag_word(th2));
+ flush |= skb->ip_summed != p->ip_summed;
+ flush |= skb->csum_level != p->csum_level;
+ flush |= !pskb_may_pull(skb, skb_gro_offset(skb));
+ flush |= NAPI_GRO_CB(p)->count >= 64;
+
+ if (flush || skb_gro_receive_list(p, skb))
+ mss = 1;
+
+ goto out_check_final;
+ }
+
if (flush || skb_gro_receive(p, skb)) {
mss = 1;
goto out_check_final;
@@ -290,7 +383,6 @@ out_check_final:
if (p && (!NAPI_GRO_CB(skb)->same_flow || flush))
pp = p;
-out:
NAPI_GRO_CB(skb)->flush |= (flush != 0);
return pp;
@@ -314,18 +406,56 @@ void tcp_gro_complete(struct sk_buff *sk
}
EXPORT_SYMBOL(tcp_gro_complete);
+static void tcp4_check_fraglist_gro(struct list_head *head, struct sk_buff *skb,
+ struct tcphdr *th)
+{
+ const struct iphdr *iph = skb_gro_network_header(skb);
+ struct net *net = dev_net(skb->dev);
+ struct sk_buff *p;
+ struct sock *sk;
+ int iif, sdif;
+
+ if (!(skb->dev->features & NETIF_F_GRO_FRAGLIST))
+ return;
+
+ p = tcp_gro_lookup(head, th);
+ if (p) {
+ NAPI_GRO_CB(skb)->is_flist = NAPI_GRO_CB(p)->is_flist;
+ return;
+ }
+
+ inet_get_iif_sdif(skb, &iif, &sdif);
+ sk = __inet_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
+ iph->saddr, th->source,
+ iph->daddr, ntohs(th->dest),
+ iif, sdif);
+ NAPI_GRO_CB(skb)->is_flist = !sk;
+ if (sk)
+ sock_put(sk);
+}
+
INDIRECT_CALLABLE_SCOPE
struct sk_buff *tcp4_gro_receive(struct list_head *head, struct sk_buff *skb)
{
+ struct tcphdr *th;
+
/* Don't bother verifying checksum if we're going to flush anyway. */
if (!NAPI_GRO_CB(skb)->flush &&
skb_gro_checksum_validate(skb, IPPROTO_TCP,
- inet_gro_compute_pseudo)) {
- NAPI_GRO_CB(skb)->flush = 1;
- return NULL;
- }
+ inet_gro_compute_pseudo))
+ goto flush;
+
+ th = tcp_gro_pull_header(skb);
+ if (!th)
+ goto flush;
- return tcp_gro_receive(head, skb);
+ tcp4_check_fraglist_gro(head, skb, th);
+
+ return tcp_gro_receive(head, skb, th);
+
+flush:
+ NAPI_GRO_CB(skb)->flush = 1;
+ return NULL;
}
INDIRECT_CALLABLE_SCOPE int tcp4_gro_complete(struct sk_buff *skb, int thoff)
@@ -333,6 +463,15 @@ INDIRECT_CALLABLE_SCOPE int tcp4_gro_com
const struct iphdr *iph = ip_hdr(skb);
struct tcphdr *th = tcp_hdr(skb);
+ if (NAPI_GRO_CB(skb)->is_flist) {
+ skb_shinfo(skb)->gso_type |= SKB_GSO_FRAGLIST | SKB_GSO_TCPV4;
+ skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
+
+ __skb_incr_checksum_unnecessary(skb);
+
+ return 0;
+ }
+
th->check = ~tcp_v4_check(skb->len - thoff, iph->saddr,
iph->daddr, 0);
skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4;
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -433,33 +433,6 @@ out:
return segs;
}
-static int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb)
-{
- if (unlikely(p->len + skb->len >= 65536))
- return -E2BIG;
-
- if (NAPI_GRO_CB(p)->last == p)
- skb_shinfo(p)->frag_list = skb;
- else
- NAPI_GRO_CB(p)->last->next = skb;
-
- skb_pull(skb, skb_gro_offset(skb));
-
- NAPI_GRO_CB(p)->last = skb;
- NAPI_GRO_CB(p)->count++;
- p->data_len += skb->len;
-
- /* sk ownership - if any - completely transferred to the aggregated packet */
- skb->destructor = NULL;
- skb->sk = NULL;
- p->truesize += skb->truesize;
- p->len += skb->len;
-
- NAPI_GRO_CB(skb)->same_flow = 1;
-
- return 0;
-}
-
#define UDP_GRO_CNT_MAX 64
static struct sk_buff *udp_gro_receive_segment(struct list_head *head,
--- a/net/ipv6/tcpv6_offload.c
+++ b/net/ipv6/tcpv6_offload.c
@@ -7,24 +7,65 @@
*/
#include <linux/indirect_call_wrapper.h>
#include <linux/skbuff.h>
+#include <net/inet6_hashtables.h>
#include <net/gro.h>
#include <net/protocol.h>
#include <net/tcp.h>
#include <net/ip6_checksum.h>
#include "ip6_offload.h"
+static void tcp6_check_fraglist_gro(struct list_head *head, struct sk_buff *skb,
+ struct tcphdr *th)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+ const struct ipv6hdr *hdr = skb_gro_network_header(skb);
+ struct net *net = dev_net(skb->dev);
+ struct sk_buff *p;
+ struct sock *sk;
+ int iif, sdif;
+
+ if (!(skb->dev->features & NETIF_F_GRO_FRAGLIST))
+ return;
+
+ p = tcp_gro_lookup(head, th);
+ if (p) {
+ NAPI_GRO_CB(skb)->is_flist = NAPI_GRO_CB(p)->is_flist;
+ return;
+ }
+
+ inet6_get_iif_sdif(skb, &iif, &sdif);
+ sk = __inet6_lookup_established(net, net->ipv4.tcp_death_row.hashinfo,
+ &hdr->saddr, th->source,
+ &hdr->daddr, ntohs(th->dest),
+ iif, sdif);
+ NAPI_GRO_CB(skb)->is_flist = !sk;
+ if (sk)
+ sock_put(sk);
+#endif /* IS_ENABLED(CONFIG_IPV6) */
+}
+
INDIRECT_CALLABLE_SCOPE
struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)
{
+ struct tcphdr *th;
+
/* Don't bother verifying checksum if we're going to flush anyway. */
if (!NAPI_GRO_CB(skb)->flush &&
skb_gro_checksum_validate(skb, IPPROTO_TCP,
- ip6_gro_compute_pseudo)) {
- NAPI_GRO_CB(skb)->flush = 1;
- return NULL;
- }
+ ip6_gro_compute_pseudo))
+ goto flush;
- return tcp_gro_receive(head, skb);
+ th = tcp_gro_pull_header(skb);
+ if (!th)
+ goto flush;
+
+ tcp6_check_fraglist_gro(head, skb, th);
+
+ return tcp_gro_receive(head, skb, th);
+
+flush:
+ NAPI_GRO_CB(skb)->flush = 1;
+ return NULL;
}
INDIRECT_CALLABLE_SCOPE int tcp6_gro_complete(struct sk_buff *skb, int thoff)
@@ -32,6 +73,15 @@ INDIRECT_CALLABLE_SCOPE int tcp6_gro_com
const struct ipv6hdr *iph = ipv6_hdr(skb);
struct tcphdr *th = tcp_hdr(skb);
+ if (NAPI_GRO_CB(skb)->is_flist) {
+ skb_shinfo(skb)->gso_type |= SKB_GSO_FRAGLIST | SKB_GSO_TCPV6;
+ skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
+
+ __skb_incr_checksum_unnecessary(skb);
+
+ return 0;
+ }
+
th->check = ~tcp_v6_check(skb->len - thoff, &iph->saddr,
&iph->daddr, 0);
skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6;
@@ -51,6 +101,9 @@ static struct sk_buff *tcp6_gso_segment(
if (!pskb_may_pull(skb, sizeof(*th)))
return ERR_PTR(-EINVAL);
+ if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST)
+ return skb_segment_list(skb, features, skb_mac_header_len(skb));
+
if (unlikely(skb->ip_summed != CHECKSUM_PARTIAL)) {
const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
struct tcphdr *th = tcp_hdr(skb);
View Git Blame Copy Permalink