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authorRichard Gobert <richardbgobert@gmail.com>2024-04-30 16:35:54 +0200
committerPaolo Abeni <pabeni@redhat.com>2024-05-02 11:02:48 +0200
commit5ef31ea5d053a8f493a772ebad3f3ce82c35d845 (patch)
tree2e7507c67ac9ef73245773b0ef620d4c242f7c17
parentfc1092f51567277509563800a3c56732070b6aa4 (diff)
net: gro: fix udp bad offset in socket lookup by adding {inner_}network_offset to napi_gro_cb
Commits a602456 ("udp: Add GRO functions to UDP socket") and 57c67ff ("udp: additional GRO support") introduce incorrect usage of {ip,ipv6}_hdr in the complete phase of gro. The functions always return skb->network_header, which in the case of encapsulated packets at the gro complete phase, is always set to the innermost L3 of the packet. That means that calling {ip,ipv6}_hdr for skbs which completed the GRO receive phase (both in gro_list and *_gro_complete) when parsing an encapsulated packet's _outer_ L3/L4 may return an unexpected value. This incorrect usage leads to a bug in GRO's UDP socket lookup. udp{4,6}_lib_lookup_skb functions use ip_hdr/ipv6_hdr respectively. These *_hdr functions return network_header which will point to the innermost L3, resulting in the wrong offset being used in __udp{4,6}_lib_lookup with encapsulated packets. This patch adds network_offset and inner_network_offset to napi_gro_cb, and makes sure both are set correctly. To fix the issue, network_offsets union is used inside napi_gro_cb, in which both the outer and the inner network offsets are saved. Reproduction example: Endpoint configuration example (fou + local address bind) # ip fou add port 6666 ipproto 4 # ip link add name tun1 type ipip remote 2.2.2.1 local 2.2.2.2 encap fou encap-dport 5555 encap-sport 6666 mode ipip # ip link set tun1 up # ip a add 1.1.1.2/24 dev tun1 Netperf TCP_STREAM result on net-next before patch is applied: net-next main, GRO enabled: $ netperf -H 1.1.1.2 -t TCP_STREAM -l 5 Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 131072 16384 16384 5.28 2.37 net-next main, GRO disabled: $ netperf -H 1.1.1.2 -t TCP_STREAM -l 5 Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 131072 16384 16384 5.01 2745.06 patch applied, GRO enabled: $ netperf -H 1.1.1.2 -t TCP_STREAM -l 5 Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 131072 16384 16384 5.01 2877.38 Fixes: a6024562ffd7 ("udp: Add GRO functions to UDP socket") Signed-off-by: Richard Gobert <richardbgobert@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
-rw-r--r--include/net/gro.h9
-rw-r--r--net/8021q/vlan_core.c2
-rw-r--r--net/core/gro.c1
-rw-r--r--net/ipv4/af_inet.c1
-rw-r--r--net/ipv4/udp.c3
-rw-r--r--net/ipv4/udp_offload.c3
-rw-r--r--net/ipv6/ip6_offload.c1
-rw-r--r--net/ipv6/udp.c3
-rw-r--r--net/ipv6/udp_offload.c3
9 files changed, 22 insertions, 4 deletions
diff --git a/include/net/gro.h b/include/net/gro.h
index 50f1e403dbbb..c1d4ca0463a1 100644
--- a/include/net/gro.h
+++ b/include/net/gro.h
@@ -87,6 +87,15 @@ struct napi_gro_cb {
/* used to support CHECKSUM_COMPLETE for tunneling protocols */
__wsum csum;
+
+ /* L3 offsets */
+ union {
+ struct {
+ u16 network_offset;
+ u16 inner_network_offset;
+ };
+ u16 network_offsets[2];
+ };
};
#define NAPI_GRO_CB(skb) ((struct napi_gro_cb *)(skb)->cb)
diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c
index f00158234505..9404dd551dfd 100644
--- a/net/8021q/vlan_core.c
+++ b/net/8021q/vlan_core.c
@@ -478,6 +478,8 @@ static struct sk_buff *vlan_gro_receive(struct list_head *head,
if (unlikely(!vhdr))
goto out;
+ NAPI_GRO_CB(skb)->network_offsets[NAPI_GRO_CB(skb)->encap_mark] = hlen;
+
type = vhdr->h_vlan_encapsulated_proto;
ptype = gro_find_receive_by_type(type);
diff --git a/net/core/gro.c b/net/core/gro.c
index 83f35d99a682..c7901253a1a8 100644
--- a/net/core/gro.c
+++ b/net/core/gro.c
@@ -371,6 +371,7 @@ static inline void skb_gro_reset_offset(struct sk_buff *skb, u32 nhoff)
const skb_frag_t *frag0;
unsigned int headlen;
+ NAPI_GRO_CB(skb)->network_offset = 0;
NAPI_GRO_CB(skb)->data_offset = 0;
headlen = skb_headlen(skb);
NAPI_GRO_CB(skb)->frag0 = skb->data;
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 55bd72997b31..fafb123f798b 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1572,6 +1572,7 @@ struct sk_buff *inet_gro_receive(struct list_head *head, struct sk_buff *skb)
/* The above will be needed by the transport layer if there is one
* immediately following this IP hdr.
*/
+ NAPI_GRO_CB(skb)->inner_network_offset = off;
/* Note : No need to call skb_gro_postpull_rcsum() here,
* as we already checked checksum over ipv4 header was 0
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 420905be5f30..b32cf2eeeb41 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -532,7 +532,8 @@ static inline struct sock *__udp4_lib_lookup_skb(struct sk_buff *skb,
struct sock *udp4_lib_lookup_skb(const struct sk_buff *skb,
__be16 sport, __be16 dport)
{
- const struct iphdr *iph = ip_hdr(skb);
+ const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
+ const struct iphdr *iph = (struct iphdr *)(skb->data + offset);
struct net *net = dev_net(skb->dev);
int iif, sdif;
diff --git a/net/ipv4/udp_offload.c b/net/ipv4/udp_offload.c
index 3498dd1d0694..fd29d21d579c 100644
--- a/net/ipv4/udp_offload.c
+++ b/net/ipv4/udp_offload.c
@@ -718,7 +718,8 @@ EXPORT_SYMBOL(udp_gro_complete);
INDIRECT_CALLABLE_SCOPE int udp4_gro_complete(struct sk_buff *skb, int nhoff)
{
- const struct iphdr *iph = ip_hdr(skb);
+ const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
+ const struct iphdr *iph = (struct iphdr *)(skb->data + offset);
struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
/* do fraglist only if there is no outer UDP encap (or we already processed it) */
diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c
index b41e35af69ea..c8b909a9904f 100644
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -237,6 +237,7 @@ INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,
goto out;
skb_set_network_header(skb, off);
+ NAPI_GRO_CB(skb)->inner_network_offset = off;
flush += ntohs(iph->payload_len) != skb->len - hlen;
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 1a4cccdd40c9..8f7aa8bac1e7 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -272,7 +272,8 @@ static struct sock *__udp6_lib_lookup_skb(struct sk_buff *skb,
struct sock *udp6_lib_lookup_skb(const struct sk_buff *skb,
__be16 sport, __be16 dport)
{
- const struct ipv6hdr *iph = ipv6_hdr(skb);
+ const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
+ const struct ipv6hdr *iph = (struct ipv6hdr *)(skb->data + offset);
struct net *net = dev_net(skb->dev);
int iif, sdif;
diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index bbd347de00b4..b41152dd4246 100644
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -164,7 +164,8 @@ flush:
INDIRECT_CALLABLE_SCOPE int udp6_gro_complete(struct sk_buff *skb, int nhoff)
{
- const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
+ const u16 offset = NAPI_GRO_CB(skb)->network_offsets[skb->encapsulation];
+ const struct ipv6hdr *ipv6h = (struct ipv6hdr *)(skb->data + offset);
struct udphdr *uh = (struct udphdr *)(skb->data + nhoff);
/* do fraglist only if there is no outer UDP encap (or we already processed it) */