The commit 0813a841566f ("bpf: tcp: Allow bpf prog to write and parse TCP header option")
unnecessarily introduced bpf_skops_init_child() which limited the child
sk from inheriting all bpf_sock_ops_cb_flags of the listen sk. That
breaks existing user expectation.
This patch removes the bpf_skops_init_child() and just allows
sock_copy() to do its job to copy everything from listen sk to
the child sk.
Fixes: 0813a841566f ("bpf: tcp: Allow bpf prog to write and parse TCP header option")
Reported-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
Signed-off-by: Martin KaFai Lau <kafai@xxxxxx>
---
include/net/tcp.h | 33 ---------------------------------
net/ipv4/tcp_minisocks.c | 1 -
2 files changed, 34 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 3601dea931a6..d4ef5bf94168 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2228,34 +2228,6 @@ int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock,
#endif /* CONFIG_NET_SOCK_MSG */
#ifdef CONFIG_CGROUP_BPF
-/* Copy the listen sk's HDR_OPT_CB flags to its child.
- *
- * During 3-Way-HandShake, the synack is usually sent from
- * the listen sk with the HDR_OPT_CB flags set so that
- * bpf-prog will be called to write the BPF hdr option.
- *
- * In fastopen, the child sk is used to send synack instead
- * of the listen sk. Thus, inheriting the HDR_OPT_CB flags
- * from the listen sk gives the bpf-prog a chance to write
- * BPF hdr option in the synack pkt during fastopen.
- *
- * Both fastopen and non-fastopen child will inherit the
- * HDR_OPT_CB flags to keep the bpf-prog having a consistent
- * behavior when deciding to clear this cb flags (or not)
- * during the PASSIVE_ESTABLISHED_CB.
- *
- * In the future, other cb flags could be inherited here also.
- */
-static inline void bpf_skops_init_child(const struct sock *sk,
- struct sock *child)
-{
- tcp_sk(child)->bpf_sock_ops_cb_flags =
- tcp_sk(sk)->bpf_sock_ops_cb_flags &
- (BPF_SOCK_OPS_PARSE_ALL_HDR_OPT_CB_FLAG |
- BPF_SOCK_OPS_PARSE_UNKNOWN_HDR_OPT_CB_FLAG |
- BPF_SOCK_OPS_WRITE_HDR_OPT_CB_FLAG);
-}
-
static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops,
struct sk_buff *skb,
unsigned int end_offset)
@@ -2264,11 +2236,6 @@ static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops,
skops->skb_data_end = skb->data + end_offset;
}
#else
-static inline void bpf_skops_init_child(const struct sock *sk,
- struct sock *child)
-{
-}
-
static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops,
struct sk_buff *skb,
unsigned int end_offset)
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 56c306e3cd2f..495dda2449fe 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -548,7 +548,6 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
newtp->fastopen_req = NULL;
RCU_INIT_POINTER(newtp->fastopen_rsk, NULL);
- bpf_skops_init_child(sk, newsk);
tcp_bpf_clone(sk, newsk);
__TCP_INC_STATS(sock_net(sk), TCP_MIB_PASSIVEOPENS);
--
2.24.1
