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// SPDX-License-Identifier: GPL-2.0
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include <errno.h>
#include <linux/capability.h>
struct kernel_cap_struct {
__u32 cap[_LINUX_CAPABILITY_U32S_3];
} __attribute__((preserve_access_index));
struct cred {
struct kernel_cap_struct cap_effective;
} __attribute__((preserve_access_index));
char _license[] SEC("license") = "GPL";
SEC("lsm.s/userns_create")
int BPF_PROG(test_userns_create, const struct cred *cred, int ret)
{
struct kernel_cap_struct caps = cred->cap_effective;
int cap_index = CAP_TO_INDEX(CAP_SYS_ADMIN);
__u32 cap_mask = CAP_TO_MASK(CAP_SYS_ADMIN);
if (ret)
return 0;
ret = -EPERM;
if (caps.cap[cap_index] & cap_mask)
return 0;
return -EPERM;
}
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