[PATCH bpf-next v5 09/15] bpf: add bpf_skc_to_udp6_sock() helper
From: Yonghong Song <hidden>
Date: 2020-06-23 23:08:31
Also in:
bpf
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), bpf [security & lsm] (security audit and enforcement using bpf), bpf [tracing], networking [general], the rest, tracing · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, KP Singh, Matt Bobrowski, Song Liu, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
The helper is used in tracing programs to cast a socket pointer to a udp6_sock pointer. The return value could be NULL if the casting is illegal. Cc: Eric Dumazet <edumazet@google.com> Acked-by: Martin KaFai Lau <redacted> Signed-off-by: Yonghong Song <redacted> --- include/linux/bpf.h | 1 + include/uapi/linux/bpf.h | 9 ++++++++- kernel/trace/bpf_trace.c | 2 ++ net/core/filter.c | 22 ++++++++++++++++++++++ scripts/bpf_helpers_doc.py | 2 ++ tools/include/uapi/linux/bpf.h | 9 ++++++++- 6 files changed, 43 insertions(+), 2 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index c23998cf6699..3d2ade703a35 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h@@ -1653,6 +1653,7 @@ extern const struct bpf_func_proto bpf_skc_to_tcp6_sock_proto; extern const struct bpf_func_proto bpf_skc_to_tcp_sock_proto; extern const struct bpf_func_proto bpf_skc_to_tcp_timewait_sock_proto; extern const struct bpf_func_proto bpf_skc_to_tcp_request_sock_proto; +extern const struct bpf_func_proto bpf_skc_to_udp6_sock_proto; const struct bpf_func_proto *bpf_tracing_func_proto( enum bpf_func_id func_id, const struct bpf_prog *prog);
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index e256417d94c2..3f4b12c5c563 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h@@ -3276,6 +3276,12 @@ union bpf_attr { * Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer. * Return * *sk* if casting is valid, or NULL otherwise. + * + * struct udp6_sock *bpf_skc_to_udp6_sock(void *sk) + * Description + * Dynamically cast a *sk* pointer to a *udp6_sock* pointer. + * Return + * *sk* if casting is valid, or NULL otherwise. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \
@@ -3417,7 +3423,8 @@ union bpf_attr { FN(skc_to_tcp6_sock), \ FN(skc_to_tcp_sock), \ FN(skc_to_tcp_timewait_sock), \ - FN(skc_to_tcp_request_sock), + FN(skc_to_tcp_request_sock), \ + FN(skc_to_udp6_sock), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index de5fbe66e1ca..d10ab16c4a2f 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c@@ -1523,6 +1523,8 @@ tracing_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_skc_to_tcp_timewait_sock_proto; case BPF_FUNC_skc_to_tcp_request_sock: return &bpf_skc_to_tcp_request_sock_proto; + case BPF_FUNC_skc_to_udp6_sock: + return &bpf_skc_to_udp6_sock_proto; #endif case BPF_FUNC_seq_printf: return prog->expected_attach_type == BPF_TRACE_ITER ?
diff --git a/net/core/filter.c b/net/core/filter.c
index a285a2d00edc..416c6b232b01 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -9335,3 +9335,25 @@ const struct bpf_func_proto bpf_skc_to_tcp_request_sock_proto = { .check_btf_id = check_arg_btf_id, .ret_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_TCP_REQ], }; + +BPF_CALL_1(bpf_skc_to_udp6_sock, struct sock *, sk) +{ + /* udp6_sock type is not generated in dwarf and hence btf, + * trigger an explicit type generation here. + */ + BTF_TYPE_EMIT(struct udp6_sock); + if (sk_fullsock(sk) && sk->sk_protocol == IPPROTO_UDP && + sk->sk_type == SOCK_DGRAM && sk->sk_family == AF_INET6) + return (unsigned long)sk; + + return (unsigned long)NULL; +} + +const struct bpf_func_proto bpf_skc_to_udp6_sock_proto = { + .func = bpf_skc_to_udp6_sock, + .gpl_only = false, + .ret_type = RET_PTR_TO_BTF_ID_OR_NULL, + .arg1_type = ARG_PTR_TO_BTF_ID, + .check_btf_id = check_arg_btf_id, + .ret_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_UDP6], +};
diff --git a/scripts/bpf_helpers_doc.py b/scripts/bpf_helpers_doc.py
index d886657c6aaa..6bab40ff442e 100755
--- a/scripts/bpf_helpers_doc.py
+++ b/scripts/bpf_helpers_doc.py@@ -425,6 +425,7 @@ class PrinterHelpers(Printer): 'struct tcp_sock', 'struct tcp_timewait_sock', 'struct tcp_request_sock', + 'struct udp6_sock', 'struct __sk_buff', 'struct sk_msg_md',
@@ -466,6 +467,7 @@ class PrinterHelpers(Printer): 'struct tcp_sock', 'struct tcp_timewait_sock', 'struct tcp_request_sock', + 'struct udp6_sock', } mapped_types = { 'u8': '__u8',
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index e256417d94c2..3f4b12c5c563 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h@@ -3276,6 +3276,12 @@ union bpf_attr { * Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer. * Return * *sk* if casting is valid, or NULL otherwise. + * + * struct udp6_sock *bpf_skc_to_udp6_sock(void *sk) + * Description + * Dynamically cast a *sk* pointer to a *udp6_sock* pointer. + * Return + * *sk* if casting is valid, or NULL otherwise. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \
@@ -3417,7 +3423,8 @@ union bpf_attr { FN(skc_to_tcp6_sock), \ FN(skc_to_tcp_sock), \ FN(skc_to_tcp_timewait_sock), \ - FN(skc_to_tcp_request_sock), + FN(skc_to_tcp_request_sock), \ + FN(skc_to_udp6_sock), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call
--
2.24.1