On Fri, Jul 31, 2020 at 09:12:10AM -0700, Eric Dumazet wrote: > On Thu, Jul 30, 2020 at 1:58 PM Martin KaFai Lau <kafai@xxxxxx> wrote: > > > > In the latter patch, the bpf prog only wants to be called to handle > > a header option if that particular header option cannot be handled by > > the kernel. This unknown option could be written by the peer's bpf-prog. > > It could also be a new standard option that the running kernel does not > > support it while a bpf-prog can handle it. > > > > In a latter patch, the bpf prog will be called from tcp_validate_incoming() > > if there is unknown option and a flag is set in tp->bpf_sock_ops_cb_flags. > > > > Instead of using skb->cb[] in an earlier attempt, this patch > > adds an optional arg "bool *unknown_opt" to tcp_parse_options(). > > The bool will be set to true if it has encountered an option > > that the kernel does not recognize. > > > > Signed-off-by: Martin KaFai Lau <kafai@xxxxxx> > > --- > > drivers/infiniband/hw/cxgb4/cm.c | 2 +- > > include/net/tcp.h | 3 ++- > > net/ipv4/syncookies.c | 2 +- > > net/ipv4/tcp_input.c | 40 +++++++++++++++++++++----------- > > net/ipv4/tcp_minisocks.c | 4 ++-- > > net/ipv6/syncookies.c | 2 +- > > 6 files changed, 34 insertions(+), 19 deletions(-) > > > > diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c > > index 30e08bcc9afb..dedca6576bb9 100644 > > --- a/drivers/infiniband/hw/cxgb4/cm.c > > +++ b/drivers/infiniband/hw/cxgb4/cm.c > > @@ -3949,7 +3949,7 @@ static void build_cpl_pass_accept_req(struct sk_buff *skb, int stid , u8 tos) > > */ > > memset(&tmp_opt, 0, sizeof(tmp_opt)); > > tcp_clear_options(&tmp_opt); > > - tcp_parse_options(&init_net, skb, &tmp_opt, 0, NULL); > > + tcp_parse_options(&init_net, skb, &tmp_opt, 0, NULL, NULL); > > > > req = __skb_push(skb, sizeof(*req)); > > memset(req, 0, sizeof(*req)); > > diff --git a/include/net/tcp.h b/include/net/tcp.h > > index 895e7aabf136..d49d8f1c961a 100644 > > --- a/include/net/tcp.h > > +++ b/include/net/tcp.h > > @@ -413,7 +413,8 @@ int tcp_mmap(struct file *file, struct socket *sock, > > #endif > > void tcp_parse_options(const struct net *net, const struct sk_buff *skb, > > struct tcp_options_received *opt_rx, > > - int estab, struct tcp_fastopen_cookie *foc); > > + int estab, struct tcp_fastopen_cookie *foc, > > + bool *unknown_opt); > > const u8 *tcp_parse_md5sig_option(const struct tcphdr *th); > > > > Instead of changing signatures of many functions (and make future > stable backports challenging) > how about adding a field into 'struct tcp_options_received' ? Sounds good. There is a one byte hole in 'struct tcp_options_received', so it won't matter much even there is "rx_opt" in "struct tcp_sock".
