On 9/15/22 9:11 AM, KP Singh wrote:
On Fri, Sep 9, 2022 at 1:10 PM Roberto Sassu
<roberto.sassu@xxxxxxxxxxxxxxx> wrote:
From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
[...]
+}
diff --git a/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c b/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c
new file mode 100644
index 000000000000..4ceab545d99a
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_verify_pkcs7_sig.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright (C) 2022 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
+ */
+
+#include "vmlinux.h"
+#include <errno.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#define MAX_DATA_SIZE (1024 * 1024)
+#define MAX_SIG_SIZE 1024
+
+typedef __u8 u8;
+typedef __u16 u16;
+typedef __u32 u32;
+typedef __u64 u64;
I think you can avoid this and just use u32 and u64 directly.
For consistency of typical bpf programs and bpf.h, using __u{8,16,32,64}
should be okay.
+
+struct bpf_dynptr {
+ __u64 :64;
+ __u64 :64;
+} __attribute__((aligned(8)));
+
I think you are doing this because including the uapi headers causes
type conflicts.
This does happen quite often. What do other folks think about doing
something like
#define DYNPTR(x) ((void *)x)
It seems like this will be an issue anytime we use the helpers with
vmlinux.h and users
will always have to define this type in their tests.
We can use BTF_TYPE_EMIT macro to emit bpf_dynptr type to vmlinux dwarf
and then to vmlinux BTF and vmlinux.h. For example, with below change,
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 41aeaf3862ec..bbdc53fec625 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -1400,6 +1400,7 @@ static const struct bpf_func_proto
bpf_kptr_xchg_proto = {
static bool bpf_dynptr_is_rdonly(struct bpf_dynptr_kern *ptr)
{
+ BTF_TYPE_EMIT(struct bpf_dynptr);
return ptr->size & DYNPTR_RDONLY_BIT;
}
in vmlinux.h, we will have
struct bpf_dynptr {
long: 64;
long: 64;};
- KP
+extern struct bpf_key *bpf_lookup_user_key(__u32 serial, __u64 flags) __ksym;
+extern struct bpf_key *bpf_lookup_system_key(__u64 id) __ksym;
+extern void bpf_key_put(struct bpf_key *key) __ksym;
+extern int bpf_verify_pkcs7_signature(struct bpf_dynptr *data_ptr,
+ struct bpf_dynptr *sig_ptr,
+ struct bpf_key *trusted_keyring) __ksym;
+
+u32 monitored_pid;
+u32 user_keyring_serial;
+u64 system_keyring_id;
+
+struct data {
+ u8 data[MAX_DATA_SIZE];
+ u32 data_len;
+ u8 sig[MAX_SIG_SIZE];
+ u32 sig_len;
+};
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY);
+ __uint(max_entries, 1);
+ __type(key, __u32);
+ __type(value, struct data);
+} data_input SEC(".maps");
+
+char _license[] SEC("license") = "GPL";
+
+SEC("lsm.s/bpf")
+int BPF_PROG(bpf, int cmd, union bpf_attr *attr, unsigned int size)
+{
+ struct bpf_dynptr data_ptr, sig_ptr;
+ struct data *data_val;
+ struct bpf_key *trusted_keyring;
+ u32 pid;
+ u64 value;
+ int ret, zero = 0;
+
+ pid = bpf_get_current_pid_tgid() >> 32;
+ if (pid != monitored_pid)
+ return 0;
+
+ data_val = bpf_map_lookup_elem(&data_input, &zero);
+ if (!data_val)
+ return 0;
+
+ bpf_probe_read(&value, sizeof(value), &attr->value);
+
+ bpf_copy_from_user(data_val, sizeof(struct data),
[...]
--
2.25.1
