From 0bc919d3e0b8149a60d2444c6a8e2b5974556522 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maciej=20=C5=BBenczykowski?= <maze@google.com>
Date: Wed, 16 Jun 2021 17:09:52 -0700
Subject: [PATCH] bpf: Support all gso types in bpf_skb_change_proto()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
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
net/core/lwt_bpf.c's handle_gso_type()
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Dongseok Yi <dseok.yi@samsung.com>
Cc: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/bpf/20210617000953.2787453-3-zenczykowski@gmail.com
---
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 ae92a8bada0f9..d062053994c7b 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);
--
GitLab