From: Willem de Bruijn <will...@google.com>
BPF can adjust gso only for tcp bytestreams. Fail on other gso types.
But only on gso packets. It does not touch this field if !gso_size.
Fixes: b90efd225874 ("bpf: only adjust gso_size on bytestream protocols")
Signed-off-by: Willem de Bruijn <will...@google.com>
---
Stupid bug on my part. Found only when adding tests for the feature.
Will try to upstream those once bpf-next opens.
On a related note, also working on a flag BPF_F_ADJ_ROOM_FIXED_GSO
that will allow reenabling this field for UDP (and possibly avoiding
the expensive skb_cow for the TCP common case).
---
include/linux/skbuff.h | 4 ++--
net/core/filter.c | 8 ++++----
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 27beb549ffbe1..f32f32407dc43 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -4232,10 +4232,10 @@ static inline bool skb_is_gso_sctp(const struct sk_buff
*skb)
return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP;
}
+/* Note: Should be called only if skb_is_gso(skb) is true */
static inline bool skb_is_gso_tcp(const struct sk_buff *skb)
{
- return skb_is_gso(skb) &&
- skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6);
+ return skb_shinfo(skb)->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6);
}
static inline void skb_gso_reset(struct sk_buff *skb)
diff --git a/net/core/filter.c b/net/core/filter.c
index 5ceba98069d46..f274620945ff0 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2804,7 +2804,7 @@ static int bpf_skb_proto_4_to_6(struct sk_buff *skb)
u32 off = skb_mac_header_len(skb);
int ret;
- if (!skb_is_gso_tcp(skb))
+ if (skb_is_gso(skb) && !skb_is_gso_tcp(skb))
return -ENOTSUPP;
ret = skb_cow(skb, len_diff);
@@ -2845,7 +2845,7 @@ static int bpf_skb_proto_6_to_4(struct sk_buff *skb)
u32 off = skb_mac_header_len(skb);
int ret;
- if (!skb_is_gso_tcp(skb))
+ if (skb_is_gso(skb) && !skb_is_gso_tcp(skb))
return -ENOTSUPP;
ret = skb_unclone(skb, GFP_ATOMIC);
@@ -2970,7 +2970,7 @@ static int bpf_skb_net_grow(struct sk_buff *skb, u32
len_diff)
u32 off = skb_mac_header_len(skb) + bpf_skb_net_base_len(skb);
int ret;
- if (!skb_is_gso_tcp(skb))
+ if (skb_is_gso(skb) && !skb_is_gso_tcp(skb))
return -ENOTSUPP;
ret = skb_cow(skb, len_diff);
@@ -2999,7 +2999,7 @@ static int bpf_skb_net_shrink(struct sk_buff *skb, u32
len_diff)
u32 off = skb_mac_header_len(skb) + bpf_skb_net_base_len(skb);
int ret;
- if (!skb_is_gso_tcp(skb))
+ if (skb_is_gso(skb) && !skb_is_gso_tcp(skb))
return -ENOTSUPP;
ret = skb_unclone(skb, GFP_ATOMIC);
--
2.21.0.352.gf09ad66450-goog
