From fd9c663b9ad67dedfc9a3fd3429ddd3e83782b4d Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 21 Apr 2023 19:02:55 +0200 Subject: bpf: minimal support for programs hooked into netfilter framework This adds minimal support for BPF_PROG_TYPE_NETFILTER bpf programs that will be invoked via the NF_HOOK() points in the ip stack. Invocation incurs an indirect call. This is not a necessity: Its possible to add 'DEFINE_BPF_DISPATCHER(nf_progs)' and handle the program invocation with the same method already done for xdp progs. This isn't done here to keep the size of this chunk down. Verifier restricts verdicts to either DROP or ACCEPT. Signed-off-by: Florian Westphal Link: https://lore.kernel.org/r/20230421170300.24115-3-fw@strlen.de Signed-off-by: Alexei Starovoitov --- kernel/bpf/btf.c | 6 ++++++ kernel/bpf/verifier.c | 3 +++ 2 files changed, 9 insertions(+) (limited to 'kernel') diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 7db4ec125fbd..6b682b8e4b50 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -25,6 +25,9 @@ #include #include #include + +#include + #include #include "../tools/lib/bpf/relo_core.h" @@ -212,6 +215,7 @@ enum btf_kfunc_hook { BTF_KFUNC_HOOK_SK_SKB, BTF_KFUNC_HOOK_SOCKET_FILTER, BTF_KFUNC_HOOK_LWT, + BTF_KFUNC_HOOK_NETFILTER, BTF_KFUNC_HOOK_MAX, }; @@ -7802,6 +7806,8 @@ static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type) case BPF_PROG_TYPE_LWT_XMIT: case BPF_PROG_TYPE_LWT_SEG6LOCAL: return BTF_KFUNC_HOOK_LWT; + case BPF_PROG_TYPE_NETFILTER: + return BTF_KFUNC_HOOK_NETFILTER; default: return BTF_KFUNC_HOOK_MAX; } diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 1e05355facdc..fc7281d39e46 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -13816,6 +13816,9 @@ static int check_return_code(struct bpf_verifier_env *env) } break; + case BPF_PROG_TYPE_NETFILTER: + range = tnum_range(NF_DROP, NF_ACCEPT); + break; case BPF_PROG_TYPE_EXT: /* freplace program can return anything as its return value * depends on the to-be-replaced kernel func or bpf program. -- cgit v1.3