[PATCH bpf-next v3 2/8] bpf: allow helpers to return PTR_TO_SOCK_COMMON
From: Lorenz Bauer <hidden>
Date: 2019-03-22 01:54:30
Also in:
bpf
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
It's currently not possible to access timewait or request sockets from eBPF, since there is no way to return a PTR_TO_SOCK_COMMON from a helper. Introduce RET_PTR_TO_SOCK_COMMON to enable this behaviour. Signed-off-by: Lorenz Bauer <redacted> --- include/linux/bpf.h | 1 + kernel/bpf/verifier.c | 4 ++++ 2 files changed, 5 insertions(+)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index f02367faa58d..f62897198844 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h@@ -205,6 +205,7 @@ enum bpf_return_type { RET_PTR_TO_MAP_VALUE_OR_NULL, /* returns a pointer to map elem value or NULL */ RET_PTR_TO_SOCKET_OR_NULL, /* returns a pointer to a socket or NULL */ RET_PTR_TO_TCP_SOCK_OR_NULL, /* returns a pointer to a tcp_sock or NULL */ + RET_PTR_TO_SOCK_COMMON_OR_NULL, /* returns a pointer to a sock_common or NULL */ }; /* eBPF function prototype used by verifier to allow BPF_CALLs from eBPF programs
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 868a82ad5597..a476e13201d6 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c@@ -3148,6 +3148,10 @@ static int check_helper_call(struct bpf_verifier_env *env, int func_id, int insn mark_reg_known_zero(env, regs, BPF_REG_0); regs[BPF_REG_0].type = PTR_TO_SOCKET_OR_NULL; regs[BPF_REG_0].id = ++env->id_gen; + } else if (fn->ret_type == RET_PTR_TO_SOCK_COMMON_OR_NULL) { + mark_reg_known_zero(env, regs, BPF_REG_0); + regs[BPF_REG_0].type = PTR_TO_SOCK_COMMON_OR_NULL; + regs[BPF_REG_0].id = ++env->id_gen; } else if (fn->ret_type == RET_PTR_TO_TCP_SOCK_OR_NULL) { mark_reg_known_zero(env, regs, BPF_REG_0); regs[BPF_REG_0].type = PTR_TO_TCP_SOCK_OR_NULL;
--
2.19.1