[PATCH bpf-next v2 3/4] bpf: support all gso types in bpf_skb_change_proto()
From: Maciej Żenczykowski <hidden>
Date: 2021-06-17 00:10:20
Also in:
bpf, lkml
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Maciej Żenczykowski <redacted>
Since we no longer modify gso_size, it is now theoretically
safe to not set SKB_GSO_DODGY and reset gso_segs to zero.
This also means the skb_is_gso_tcp() check should no
longer be necessary.
Unfortunately we cannot remove the skb_{decrease,increase}_gso_size()
helpers, as they are still used elsewhere:
bpf_skb_net_grow() without BPF_F_ADJ_ROOM_FIXED_GSO
bpf_skb_net_shrink() without BPF_F_ADJ_ROOM_FIXED_GSO
and
net/core/lwt_bpf.c's handle_gso_type()
Cc: Dongseok Yi <redacted>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: Maciej Żenczykowski <redacted>
---
net/core/filter.c | 22 ++--------------------
1 file changed, 2 insertions(+), 20 deletions(-)
diff --git a/net/core/filter.c b/net/core/filter.c
index 6541358a770b..8f05498f497e 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -3241,9 +3241,6 @@ 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(skb) && !skb_is_gso_tcp(skb)) - return -ENOTSUPP; - ret = skb_cow(skb, len_diff); if (unlikely(ret < 0)) return ret;
@@ -3255,17 +3252,11 @@ static int bpf_skb_proto_4_to_6(struct sk_buff *skb) if (skb_is_gso(skb)) { struct skb_shared_info *shinfo = skb_shinfo(skb); - /* SKB_GSO_TCPV4 needs to be changed into - * SKB_GSO_TCPV6. - */ + /* SKB_GSO_TCPV4 needs to be changed into SKB_GSO_TCPV6. */ if (shinfo->gso_type & SKB_GSO_TCPV4) { shinfo->gso_type &= ~SKB_GSO_TCPV4; shinfo->gso_type |= SKB_GSO_TCPV6; } - - /* Header must be checked, and gso_segs recomputed. */ - shinfo->gso_type |= SKB_GSO_DODGY; - shinfo->gso_segs = 0; } skb->protocol = htons(ETH_P_IPV6);
@@ -3280,9 +3271,6 @@ 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(skb) && !skb_is_gso_tcp(skb)) - return -ENOTSUPP; - ret = skb_unclone(skb, GFP_ATOMIC); if (unlikely(ret < 0)) return ret;
@@ -3294,17 +3282,11 @@ static int bpf_skb_proto_6_to_4(struct sk_buff *skb) if (skb_is_gso(skb)) { struct skb_shared_info *shinfo = skb_shinfo(skb); - /* SKB_GSO_TCPV6 needs to be changed into - * SKB_GSO_TCPV4. - */ + /* SKB_GSO_TCPV6 needs to be changed into SKB_GSO_TCPV4. */ if (shinfo->gso_type & SKB_GSO_TCPV6) { shinfo->gso_type &= ~SKB_GSO_TCPV6; shinfo->gso_type |= SKB_GSO_TCPV4; } - - /* Header must be checked, and gso_segs recomputed. */ - shinfo->gso_type |= SKB_GSO_DODGY; - shinfo->gso_segs = 0; } skb->protocol = htons(ETH_P_IP);
--
2.32.0.272.g935e593368-goog