1#if defined(__linux__)
2
3#include "hasLinuxCapability.h"
4
5#include <syscall.h>
6#include <unistd.h>
7#include <linux/capability.h>
8#include <linux/netlink.h>
9#include <Common/Exception.h>
10
11
12namespace DB
13{
14
15namespace ErrorCodes
16{
17 extern const int NETLINK_ERROR;
18}
19
20static __user_cap_data_struct getCapabilities()
21{
22 /// See man getcap.
23 __user_cap_header_struct request{};
24 request.version = _LINUX_CAPABILITY_VERSION_1; /// It's enough to check just single CAP_NET_ADMIN capability we are interested.
25 request.pid = getpid();
26
27 __user_cap_data_struct response{};
28
29 /// Avoid dependency on 'libcap'.
30 if (0 != syscall(SYS_capget, &request, &response))
31 throwFromErrno("Cannot do 'capget' syscall", ErrorCodes::NETLINK_ERROR);
32
33 return response;
34}
35
36bool hasLinuxCapability(int cap)
37{
38 static __user_cap_data_struct capabilities = getCapabilities();
39 return (1 << cap) & capabilities.effective;
40}
41
42}
43
44#endif
45