From 82f45c6c4a70622cc0585e3f4372e192a6491d26 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Thu, 1 Oct 2020 18:34:48 -0700 Subject: bpf: tcp: Do not limit cb_flags when creating child sk from listen sk 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 Signed-off-by: Martin KaFai Lau Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20201002013448.2542025-1-kafai@fb.com --- include/net/tcp.h | 33 --------------------------------- 1 file changed, 33 deletions(-) (limited to 'include/net') 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) -- cgit v1.2.3