From ea08eeccae9297f7aabd2ef7f0c2517ac4549acc Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:18:26 +0000
Subject: [PATCH] write in 30M
---
kernel/net/ipv4/udp_offload.c | 287 +++++++++++++++++++++++++++++++++++++++++++++++++-------
1 files changed, 248 insertions(+), 39 deletions(-)
diff --git a/kernel/net/ipv4/udp_offload.c b/kernel/net/ipv4/udp_offload.c
index 2d22d39..f4b8e56 100644
--- a/kernel/net/ipv4/udp_offload.c
+++ b/kernel/net/ipv4/udp_offload.c
@@ -1,11 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
* IPV4 GSO/GRO offload support
* Linux INET implementation
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
*
* UDPv4 GSO support
*/
@@ -13,6 +9,7 @@
#include <linux/skbuff.h>
#include <net/udp.h>
#include <net/protocol.h>
+#include <net/inet_common.h>
static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
netdev_features_t features,
@@ -187,8 +184,81 @@
}
EXPORT_SYMBOL(skb_udp_tunnel_segment);
+static void __udpv4_gso_segment_csum(struct sk_buff *seg,
+ __be32 *oldip, __be32 *newip,
+ __be16 *oldport, __be16 *newport)
+{
+ struct udphdr *uh;
+ struct iphdr *iph;
+
+ if (*oldip == *newip && *oldport == *newport)
+ return;
+
+ uh = udp_hdr(seg);
+ iph = ip_hdr(seg);
+
+ if (uh->check) {
+ inet_proto_csum_replace4(&uh->check, seg, *oldip, *newip,
+ true);
+ inet_proto_csum_replace2(&uh->check, seg, *oldport, *newport,
+ false);
+ if (!uh->check)
+ uh->check = CSUM_MANGLED_0;
+ }
+ *oldport = *newport;
+
+ csum_replace4(&iph->check, *oldip, *newip);
+ *oldip = *newip;
+}
+
+static struct sk_buff *__udpv4_gso_segment_list_csum(struct sk_buff *segs)
+{
+ struct sk_buff *seg;
+ struct udphdr *uh, *uh2;
+ struct iphdr *iph, *iph2;
+
+ seg = segs;
+ uh = udp_hdr(seg);
+ iph = ip_hdr(seg);
+
+ if ((udp_hdr(seg)->dest == udp_hdr(seg->next)->dest) &&
+ (udp_hdr(seg)->source == udp_hdr(seg->next)->source) &&
+ (ip_hdr(seg)->daddr == ip_hdr(seg->next)->daddr) &&
+ (ip_hdr(seg)->saddr == ip_hdr(seg->next)->saddr))
+ return segs;
+
+ while ((seg = seg->next)) {
+ uh2 = udp_hdr(seg);
+ iph2 = ip_hdr(seg);
+
+ __udpv4_gso_segment_csum(seg,
+ &iph2->saddr, &iph->saddr,
+ &uh2->source, &uh->source);
+ __udpv4_gso_segment_csum(seg,
+ &iph2->daddr, &iph->daddr,
+ &uh2->dest, &uh->dest);
+ }
+
+ return segs;
+}
+
+static struct sk_buff *__udp_gso_segment_list(struct sk_buff *skb,
+ netdev_features_t features,
+ bool is_ipv6)
+{
+ unsigned int mss = skb_shinfo(skb)->gso_size;
+
+ skb = skb_segment_list(skb, features, skb_mac_header_len(skb));
+ if (IS_ERR(skb))
+ return skb;
+
+ udp_hdr(skb)->len = htons(sizeof(struct udphdr) + mss);
+
+ return is_ipv6 ? skb : __udpv4_gso_segment_list_csum(skb);
+}
+
struct sk_buff *__udp_gso_segment(struct sk_buff *gso_skb,
- netdev_features_t features)
+ netdev_features_t features, bool is_ipv6)
{
struct sock *sk = gso_skb->sk;
unsigned int sum_truesize = 0;
@@ -198,6 +268,9 @@
bool copy_dtor;
__sum16 check;
__be16 newlen;
+
+ if (skb_shinfo(gso_skb)->gso_type & SKB_GSO_FRAGLIST)
+ return __udp_gso_segment_list(gso_skb, features, is_ipv6);
mss = skb_shinfo(gso_skb)->gso_size;
if (gso_skb->len <= sizeof(*uh) + mss)
@@ -211,7 +284,7 @@
gso_skb->destructor = NULL;
segs = skb_segment(gso_skb, features);
- if (unlikely(IS_ERR_OR_NULL(segs))) {
+ if (IS_ERR_OR_NULL(segs)) {
if (copy_dtor)
gso_skb->destructor = sock_wfree;
return segs;
@@ -311,7 +384,7 @@
goto out;
if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4)
- return __udp_gso_segment(skb, features);
+ return __udp_gso_segment(skb, features, false);
mss = skb_shinfo(skb)->gso_size;
if (unlikely(skb->len <= mss))
@@ -348,33 +421,116 @@
return segs;
}
+#define UDP_GRO_CNT_MAX 64
+static struct sk_buff *udp_gro_receive_segment(struct list_head *head,
+ struct sk_buff *skb)
+{
+ struct udphdr *uh = udp_gro_udphdr(skb);
+ struct sk_buff *pp = NULL;
+ struct udphdr *uh2;
+ struct sk_buff *p;
+ unsigned int ulen;
+ int ret = 0;
+
+ /* requires non zero csum, for symmetry with GSO */
+ if (!uh->check) {
+ NAPI_GRO_CB(skb)->flush = 1;
+ return NULL;
+ }
+
+ /* Do not deal with padded or malicious packets, sorry ! */
+ ulen = ntohs(uh->len);
+ if (ulen <= sizeof(*uh) || ulen != skb_gro_len(skb)) {
+ NAPI_GRO_CB(skb)->flush = 1;
+ return NULL;
+ }
+ /* pull encapsulating udp header */
+ skb_gro_pull(skb, sizeof(struct udphdr));
+
+ list_for_each_entry(p, head, list) {
+ if (!NAPI_GRO_CB(p)->same_flow)
+ continue;
+
+ uh2 = udp_hdr(p);
+
+ /* Match ports only, as csum is always non zero */
+ if ((*(u32 *)&uh->source != *(u32 *)&uh2->source)) {
+ NAPI_GRO_CB(p)->same_flow = 0;
+ continue;
+ }
+
+ if (NAPI_GRO_CB(skb)->is_flist != NAPI_GRO_CB(p)->is_flist) {
+ NAPI_GRO_CB(skb)->flush = 1;
+ return p;
+ }
+
+ /* Terminate the flow on len mismatch or if it grow "too much".
+ * Under small packet flood GRO count could elsewhere grow a lot
+ * leading to excessive truesize values.
+ * On len mismatch merge the first packet shorter than gso_size,
+ * otherwise complete the GRO packet.
+ */
+ if (ulen > ntohs(uh2->len)) {
+ pp = p;
+ } else {
+ if (NAPI_GRO_CB(skb)->is_flist) {
+ if (!pskb_may_pull(skb, skb_gro_offset(skb))) {
+ NAPI_GRO_CB(skb)->flush = 1;
+ return NULL;
+ }
+ if ((skb->ip_summed != p->ip_summed) ||
+ (skb->csum_level != p->csum_level)) {
+ NAPI_GRO_CB(skb)->flush = 1;
+ return NULL;
+ }
+ ret = skb_gro_receive_list(p, skb);
+ } else {
+ skb_gro_postpull_rcsum(skb, uh,
+ sizeof(struct udphdr));
+
+ ret = skb_gro_receive(p, skb);
+ }
+ }
+
+ if (ret || ulen != ntohs(uh2->len) ||
+ NAPI_GRO_CB(p)->count >= UDP_GRO_CNT_MAX)
+ pp = p;
+
+ return pp;
+ }
+
+ /* mismatch, but we never need to flush */
+ return NULL;
+}
+
struct sk_buff *udp_gro_receive(struct list_head *head, struct sk_buff *skb,
- struct udphdr *uh, udp_lookup_t lookup)
+ struct udphdr *uh, struct sock *sk)
{
struct sk_buff *pp = NULL;
struct sk_buff *p;
struct udphdr *uh2;
unsigned int off = skb_gro_offset(skb);
int flush = 1;
- struct sock *sk;
- if (NAPI_GRO_CB(skb)->encap_mark ||
+ NAPI_GRO_CB(skb)->is_flist = 0;
+ if (skb->dev->features & NETIF_F_GRO_FRAGLIST)
+ NAPI_GRO_CB(skb)->is_flist = sk ? !udp_sk(sk)->gro_enabled: 1;
+
+ if ((sk && udp_sk(sk)->gro_enabled) || NAPI_GRO_CB(skb)->is_flist) {
+ pp = call_gro_receive(udp_gro_receive_segment, head, skb);
+ return pp;
+ }
+
+ if (!sk || NAPI_GRO_CB(skb)->encap_mark ||
(uh->check && skb->ip_summed != CHECKSUM_PARTIAL &&
NAPI_GRO_CB(skb)->csum_cnt == 0 &&
- !NAPI_GRO_CB(skb)->csum_valid))
+ !NAPI_GRO_CB(skb)->csum_valid) ||
+ !udp_sk(sk)->gro_receive)
goto out;
/* mark that this skb passed once through the tunnel gro layer */
NAPI_GRO_CB(skb)->encap_mark = 1;
- rcu_read_lock();
- sk = (*lookup)(skb, uh->source, uh->dest);
-
- if (sk && udp_sk(sk)->gro_receive)
- goto unflush;
- goto out_unlock;
-
-unflush:
flush = 0;
list_for_each_entry(p, head, list) {
@@ -397,18 +553,28 @@
skb_gro_postpull_rcsum(skb, uh, sizeof(struct udphdr));
pp = call_gro_receive_sk(udp_sk(sk)->gro_receive, sk, head, skb);
-out_unlock:
- rcu_read_unlock();
out:
skb_gro_flush_final(skb, pp, flush);
return pp;
}
EXPORT_SYMBOL(udp_gro_receive);
-static struct sk_buff *udp4_gro_receive(struct list_head *head,
- struct sk_buff *skb)
+static struct sock *udp4_gro_lookup_skb(struct sk_buff *skb, __be16 sport,
+ __be16 dport)
+{
+ const struct iphdr *iph = skb_gro_network_header(skb);
+
+ return __udp4_lib_lookup(dev_net(skb->dev), iph->saddr, sport,
+ iph->daddr, dport, inet_iif(skb),
+ inet_sdif(skb), &udp_table, NULL);
+}
+
+INDIRECT_CALLABLE_SCOPE
+struct sk_buff *udp4_gro_receive(struct list_head *head, struct sk_buff *skb)
{
struct udphdr *uh = udp_gro_udphdr(skb);
+ struct sock *sk = NULL;
+ struct sk_buff *pp;
if (unlikely(!uh))
goto flush;
@@ -421,15 +587,39 @@
inet_gro_compute_pseudo))
goto flush;
else if (uh->check)
- skb_gro_checksum_try_convert(skb, IPPROTO_UDP, uh->check,
+ skb_gro_checksum_try_convert(skb, IPPROTO_UDP,
inet_gro_compute_pseudo);
skip:
NAPI_GRO_CB(skb)->is_ipv6 = 0;
- return udp_gro_receive(head, skb, uh, udp4_lib_lookup_skb);
+ rcu_read_lock();
+
+ if (static_branch_unlikely(&udp_encap_needed_key))
+ sk = udp4_gro_lookup_skb(skb, uh->source, uh->dest);
+
+ pp = udp_gro_receive(head, skb, uh, sk);
+ rcu_read_unlock();
+ return pp;
flush:
NAPI_GRO_CB(skb)->flush = 1;
return NULL;
+}
+
+static int udp_gro_complete_segment(struct sk_buff *skb)
+{
+ struct udphdr *uh = udp_hdr(skb);
+
+ skb->csum_start = (unsigned char *)uh - skb->head;
+ skb->csum_offset = offsetof(struct udphdr, check);
+ skb->ip_summed = CHECKSUM_PARTIAL;
+
+ skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
+ skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_L4;
+
+ if (skb->encapsulation)
+ skb->inner_transport_header = skb->transport_header;
+
+ return 0;
}
int udp_gro_complete(struct sk_buff *skb, int nhoff,
@@ -442,16 +632,22 @@
uh->len = newlen;
- /* Set encapsulation before calling into inner gro_complete() functions
- * to make them set up the inner offsets.
- */
- skb->encapsulation = 1;
-
rcu_read_lock();
- sk = (*lookup)(skb, uh->source, uh->dest);
- if (sk && udp_sk(sk)->gro_complete)
+ sk = INDIRECT_CALL_INET(lookup, udp6_lib_lookup_skb,
+ udp4_lib_lookup_skb, skb, uh->source, uh->dest);
+ if (sk && udp_sk(sk)->gro_complete) {
+ skb_shinfo(skb)->gso_type = uh->check ? SKB_GSO_UDP_TUNNEL_CSUM
+ : SKB_GSO_UDP_TUNNEL;
+
+ /* Set encapsulation before calling into inner gro_complete()
+ * functions to make them set up the inner offsets.
+ */
+ skb->encapsulation = 1;
err = udp_sk(sk)->gro_complete(sk, skb,
nhoff + sizeof(struct udphdr));
+ } else {
+ err = udp_gro_complete_segment(skb);
+ }
rcu_read_unlock();
if (skb->remcsum_offload)
@@ -461,18 +657,31 @@
}
EXPORT_SYMBOL(udp_gro_complete);
-static int udp4_gro_complete(struct sk_buff *skb, int nhoff)
+INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff)
{
const struct iphdr *iph = ip_hdr(skb);
struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
- if (uh->check) {
- skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
+ if (NAPI_GRO_CB(skb)->is_flist) {
+ uh->len = htons(skb->len - nhoff);
+
+ skb_shinfo(skb)->gso_type |= (SKB_GSO_FRAGLIST|SKB_GSO_UDP_L4);
+ skb_shinfo(skb)->gso_segs = NAPI_GRO_CB(skb)->count;
+
+ if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
+ if (skb->csum_level < SKB_MAX_CSUM_LEVEL)
+ skb->csum_level++;
+ } else {
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ skb->csum_level = 0;
+ }
+
+ return 0;
+ }
+
+ if (uh->check)
uh->check = ~udp_v4_check(skb->len - nhoff, iph->saddr,
iph->daddr, 0);
- } else {
- skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL;
- }
return udp_gro_complete(skb, nhoff, udp4_lib_lookup_skb);
}
--
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