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.
Acked-by: Martin KaFai Lau <ka...@fb.com>
Signed-off-by: Yonghong Song <y...@fb.com>
---
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 cc3f89827b89..3f5c6bb5e3a7 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1649,6 +1649,7 @@ 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 140fc0fdf3e1..9a98f3616273 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -9325,3 +9325,25 @@ 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_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
