[PATCH] Support for nlattr and nested_nlattr attribute search in EBPF filter
From: Kalimuthu Velappan <hidden>
Date: 2020-01-23 13:17:16
Also in:
bpf, lkml
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Added attribute search and nested attribute support in EBPF filter functionality. Signed-off-by: Kalimuthu Velappan <redacted> --- include/uapi/linux/bpf.h | 5 ++++- net/core/filter.c | 22 ++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 4 +++- 3 files changed, 29 insertions(+), 2 deletions(-)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index dbbcf0b..ac9794c 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h@@ -2938,7 +2938,10 @@ union bpf_attr { FN(probe_read_user), \ FN(probe_read_kernel), \ FN(probe_read_user_str), \ - FN(probe_read_kernel_str), + FN(probe_read_kernel_str), \ + FN(skb_get_nlattr), \ + FN(skb_get_nlattr_nest), + /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call
diff --git a/net/core/filter.c b/net/core/filter.c
index 538f6a7..56a87e1 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -2699,6 +2699,24 @@ static const struct bpf_func_proto bpf_set_hash_invalid_proto = { .arg1_type = ARG_PTR_TO_CTX, }; +static const struct bpf_func_proto bpf_skb_get_nlattr_proto = { + .func = bpf_skb_get_nlattr, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, +}; + +static const struct bpf_func_proto skb_get_nlattr_nest_proto = { + .func = bpf_skb_get_nlattr_nest, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, + .arg3_type = ARG_ANYTHING, +}; + BPF_CALL_2(bpf_set_hash, struct sk_buff *, skb, u32, hash) { /* Set user specified hash as L4(+), so that it gets returned
@@ -6091,6 +6109,10 @@ sk_filter_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_get_socket_uid_proto; case BPF_FUNC_perf_event_output: return &bpf_skb_event_output_proto; + case BPF_FUNC_skb_get_nlattr: + return &bpf_skb_get_nlattr_proto; + case BPF_FUNC_skb_get_nlattr_nest: + return &skb_get_nlattr_nest_proto; default: return bpf_base_func_proto(func_id); }
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index dbbcf0b..3bfbc0e 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h@@ -2938,7 +2938,9 @@ union bpf_attr { FN(probe_read_user), \ FN(probe_read_kernel), \ FN(probe_read_user_str), \ - FN(probe_read_kernel_str), + FN(probe_read_kernel_str), \ + FN(skb_get_nlattr), \ + FN(skb_get_nlattr_nest), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call
--
2.7.4