From: Yonghong Song <yhs@fb.com>
Date: Tue, 23 Jun 2020 16:08:11 -0700
Subject: bpf: Add bpf_skc_to_{tcp, tcp_timewait, tcp_request}_sock() helpers
Patch-mainline: v5.9-rc1
Git-commit: 478cfbdf5f13dfe09cfd0b1cbac821f5e27f6108
References: bsc#1177028
Three more helpers are added to cast a sock_common pointer to
an tcp_sock, tcp_timewait_sock or a tcp_request_sock for
tracing programs.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20200623230811.3988277-1-yhs@fb.com
Acked-by: Gary Lin <glin@suse.com>
---
include/linux/bpf.h | 3 +
include/uapi/linux/bpf.h | 23 ++++++++++++++-
kernel/trace/bpf_trace.c | 6 +++
net/core/filter.c | 62 +++++++++++++++++++++++++++++++++++++++++
scripts/bpf_helpers_doc.py | 6 +++
tools/include/uapi/linux/bpf.h | 23 ++++++++++++++-
6 files changed, 121 insertions(+), 2 deletions(-)
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -1659,6 +1659,9 @@ extern const struct bpf_func_proto bpf_r
extern const struct bpf_func_proto bpf_ringbuf_discard_proto;
extern const struct bpf_func_proto bpf_ringbuf_query_proto;
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;
const struct bpf_func_proto *bpf_tracing_func_proto(
enum bpf_func_id func_id, const struct bpf_prog *prog);
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -3259,6 +3259,24 @@ union bpf_attr {
* Dynamically cast a *sk* pointer to a *tcp6_sock* pointer.
* Return
* *sk* if casting is valid, or NULL otherwise.
+ *
+ * struct tcp_sock *bpf_skc_to_tcp_sock(void *sk)
+ * Description
+ * Dynamically cast a *sk* pointer to a *tcp_sock* pointer.
+ * Return
+ * *sk* if casting is valid, or NULL otherwise.
+ *
+ * struct tcp_timewait_sock *bpf_skc_to_tcp_timewait_sock(void *sk)
+ * Description
+ * Dynamically cast a *sk* pointer to a *tcp_timewait_sock* pointer.
+ * Return
+ * *sk* if casting is valid, or NULL otherwise.
+ *
+ * struct tcp_request_sock *bpf_skc_to_tcp_request_sock(void *sk)
+ * Description
+ * Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer.
+ * Return
+ * *sk* if casting is valid, or NULL otherwise.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -3397,7 +3415,10 @@ union bpf_attr {
FN(ringbuf_discard), \
FN(ringbuf_query), \
FN(csum_level), \
- FN(skc_to_tcp6_sock),
+ FN(skc_to_tcp6_sock), \
+ FN(skc_to_tcp_sock), \
+ FN(skc_to_tcp_timewait_sock), \
+ FN(skc_to_tcp_request_sock),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1478,6 +1478,12 @@ tracing_prog_func_proto(enum bpf_func_id
return &bpf_xdp_output_proto;
case BPF_FUNC_skc_to_tcp6_sock:
return &bpf_skc_to_tcp6_sock_proto;
+ case BPF_FUNC_skc_to_tcp_sock:
+ return &bpf_skc_to_tcp_sock_proto;
+ case BPF_FUNC_skc_to_tcp_timewait_sock:
+ return &bpf_skc_to_tcp_timewait_sock_proto;
+ case BPF_FUNC_skc_to_tcp_request_sock:
+ return &bpf_skc_to_tcp_request_sock_proto;
#endif
case BPF_FUNC_seq_printf:
return prog->expected_attach_type == BPF_TRACE_ITER ?
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -74,6 +74,7 @@
#include <net/lwtunnel.h>
#include <net/ipv6_stubs.h>
#include <net/bpf_sk_storage.h>
+#include <net/transp_v6.h>
/**
* sk_filter_trim_cap - run a packet through a socket filter
@@ -9291,3 +9292,64 @@ const struct bpf_func_proto bpf_skc_to_t
.check_btf_id = check_arg_btf_id,
.ret_btf_id = &btf_sock_ids[BTF_SOCK_TYPE_TCP6],
};
+
+BPF_CALL_1(bpf_skc_to_tcp_sock, struct sock *, sk)
+{
+ if (sk_fullsock(sk) && sk->sk_protocol == IPPROTO_TCP)
+ return (unsigned long)sk;
+
+ return (unsigned long)NULL;
+}
+
+const struct bpf_func_proto bpf_skc_to_tcp_sock_proto = {
+ .func = bpf_skc_to_tcp_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_TCP],
+};
+
+BPF_CALL_1(bpf_skc_to_tcp_timewait_sock, struct sock *, sk)
+{
+ if (sk->sk_prot == &tcp_prot && sk->sk_state == TCP_TIME_WAIT)
+ return (unsigned long)sk;
+
+#if IS_BUILTIN(CONFIG_IPV6)
+ if (sk->sk_prot == &tcpv6_prot && sk->sk_state == TCP_TIME_WAIT)
+ return (unsigned long)sk;
+#endif
+
+ return (unsigned long)NULL;
+}
+
+const struct bpf_func_proto bpf_skc_to_tcp_timewait_sock_proto = {
+ .func = bpf_skc_to_tcp_timewait_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_TCP_TW],
+};
+
+BPF_CALL_1(bpf_skc_to_tcp_request_sock, struct sock *, sk)
+{
+ if (sk->sk_prot == &tcp_prot && sk->sk_state == TCP_NEW_SYN_RECV)
+ return (unsigned long)sk;
+
+#if IS_BUILTIN(CONFIG_IPV6)
+ if (sk->sk_prot == &tcpv6_prot && sk->sk_state == TCP_NEW_SYN_RECV)
+ return (unsigned long)sk;
+#endif
+
+ return (unsigned long)NULL;
+}
+
+const struct bpf_func_proto bpf_skc_to_tcp_request_sock_proto = {
+ .func = bpf_skc_to_tcp_request_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_TCP_REQ],
+};
--- a/scripts/bpf_helpers_doc.py
+++ b/scripts/bpf_helpers_doc.py
@@ -422,6 +422,9 @@ class PrinterHelpers(Printer):
'struct tcphdr',
'struct seq_file',
'struct tcp6_sock',
+ 'struct tcp_sock',
+ 'struct tcp_timewait_sock',
+ 'struct tcp_request_sock',
'struct __sk_buff',
'struct sk_msg_md',
@@ -460,6 +463,9 @@ class PrinterHelpers(Printer):
'struct tcphdr',
'struct seq_file',
'struct tcp6_sock',
+ 'struct tcp_sock',
+ 'struct tcp_timewait_sock',
+ 'struct tcp_request_sock',
}
mapped_types = {
'u8': '__u8',
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -3259,6 +3259,24 @@ union bpf_attr {
* Dynamically cast a *sk* pointer to a *tcp6_sock* pointer.
* Return
* *sk* if casting is valid, or NULL otherwise.
+ *
+ * struct tcp_sock *bpf_skc_to_tcp_sock(void *sk)
+ * Description
+ * Dynamically cast a *sk* pointer to a *tcp_sock* pointer.
+ * Return
+ * *sk* if casting is valid, or NULL otherwise.
+ *
+ * struct tcp_timewait_sock *bpf_skc_to_tcp_timewait_sock(void *sk)
+ * Description
+ * Dynamically cast a *sk* pointer to a *tcp_timewait_sock* pointer.
+ * Return
+ * *sk* if casting is valid, or NULL otherwise.
+ *
+ * struct tcp_request_sock *bpf_skc_to_tcp_request_sock(void *sk)
+ * Description
+ * Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer.
+ * Return
+ * *sk* if casting is valid, or NULL otherwise.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -3397,7 +3415,10 @@ union bpf_attr {
FN(ringbuf_discard), \
FN(ringbuf_query), \
FN(csum_level), \
- FN(skc_to_tcp6_sock),
+ FN(skc_to_tcp6_sock), \
+ FN(skc_to_tcp_sock), \
+ FN(skc_to_tcp_timewait_sock), \
+ FN(skc_to_tcp_request_sock),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call