LXR linux/tools/testing/selftests/bpf/cap

   1// SPDX-License-Identifier: GPL-2.0
   2#include "cap_helpers.h"
   3
   4/* Avoid including <sys/capability.h> from the libcap-devel package,
   5 * so directly declare them here and use them from glibc.
   6 */
   7int capget(cap_user_header_t header, cap_user_data_t data);
   8int capset(cap_user_header_t header, const cap_user_data_t data);
   9
  10int cap_enable_effective(__u64 caps, __u64 *old_caps)
  11{
  12        struct __user_cap_data_struct data[_LINUX_CAPABILITY_U32S_3];
  13        struct __user_cap_header_struct hdr = {
  14                .version = _LINUX_CAPABILITY_VERSION_3,
  15        };
  16        __u32 cap0 = caps;
  17        __u32 cap1 = caps >> 32;
  18        int err;
  19
  20        err = capget(&hdr, data);
  21        if (err)
  22                return err;
  23
  24        if (old_caps)
  25                *old_caps = (__u64)(data[1].effective) << 32 | data[0].effective;
  26
  27        if ((data[0].effective & cap0) == cap0 &&
  28            (data[1].effective & cap1) == cap1)
  29                return 0;
  30
  31        data[0].effective |= cap0;
  32        data[1].effective |= cap1;
  33        err = capset(&hdr, data);
  34        if (err)
  35                return err;
  36
  37        return 0;
  38}
  39
  40int cap_disable_effective(__u64 caps, __u64 *old_caps)
  41{
  42        struct __user_cap_data_struct data[_LINUX_CAPABILITY_U32S_3];
  43        struct __user_cap_header_struct hdr = {
  44                .version = _LINUX_CAPABILITY_VERSION_3,
  45        };
  46        __u32 cap0 = caps;
  47        __u32 cap1 = caps >> 32;
  48        int err;
  49
  50        err = capget(&hdr, data);
  51        if (err)
  52                return err;
  53
  54        if (old_caps)
  55                *old_caps = (__u64)(data[1].effective) << 32 | data[0].effective;
  56
  57        if (!(data[0].effective & cap0) && !(data[1].effective & cap1))
  58                return 0;
  59
  60        data[0].effective &= ~cap0;
  61        data[1].effective &= ~cap1;
  62        err = capset(&hdr, data);
  63        if (err)
  64                return err;
  65
  66        return 0;
  67}
  68