bpf: Remove extra lock_sock for TCP_ZEROCOPY_RECEIVE

[ Upstream commit 9cacf81f8161111db25f98e78a7a0e32ae142b3f ]

Add custom implementation of getsockopt hook for TCP_ZEROCOPY_RECEIVE.
We skip generic hooks for TCP_ZEROCOPY_RECEIVE and have a custom
call in do_tcp_getsockopt using the on-stack data. This removes
3% overhead for locking/unlocking the socket.

Without this patch:
     3.38%     0.07%  tcp_mmap  [kernel.kallsyms]  [k] __cgroup_bpf_run_filter_getsockopt
            |
             --3.30%--__cgroup_bpf_run_filter_getsockopt
                       |
                        --0.81%--__kmalloc

With the patch applied:
     0.52%     0.12%  tcp_mmap  [kernel.kallsyms]  [k] __cgroup_bpf_run_filter_getsockopt_kern

Note, exporting uapi/tcp.h requires removing netinet/tcp.h
from test_progs.h because those headers have confliciting
definitions.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210115163501.805133-2-sdf@google.com
Stable-dep-of: 2598619e012c ("sctp: add bpf_bypass_getsockopt proto callback")
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/net/socket.c b/net/socket.c
index 8422341..f2172b7 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2137,6 +2137,9 @@ SYSCALL_DEFINE5(setsockopt, int, fd, int, level, int, optname,
 	return __sys_setsockopt(fd, level, optname, optval, optlen);
 }
 
+INDIRECT_CALLABLE_DECLARE(bool tcp_bpf_bypass_getsockopt(int level,
+							 int optname));
+
 /*
  *	Get a socket option. Because we don't know the option lengths we have
  *	to pass a user mode parameter for the protocols to sort out.