diff options
Diffstat (limited to '')
| -rw-r--r-- | tools/testing/selftests/bpf/cap_helpers.c | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/cap_helpers.c b/tools/testing/selftests/bpf/cap_helpers.c new file mode 100644 index 000000000..d5ac50740 --- /dev/null +++ b/tools/testing/selftests/bpf/cap_helpers.c @@ -0,0 +1,67 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "cap_helpers.h" + +/* Avoid including <sys/capability.h> from the libcap-devel package, + * so directly declare them here and use them from glibc. + */ +int capget(cap_user_header_t header, cap_user_data_t data); +int capset(cap_user_header_t header, const cap_user_data_t data); + +int cap_enable_effective(__u64 caps, __u64 *old_caps) +{ + struct __user_cap_data_struct data[_LINUX_CAPABILITY_U32S_3]; + struct __user_cap_header_struct hdr = { + .version = _LINUX_CAPABILITY_VERSION_3, + }; + __u32 cap0 = caps; + __u32 cap1 = caps >> 32; + int err; + + err = capget(&hdr, data); + if (err) + return err; + + if (old_caps) + *old_caps = (__u64)(data[1].effective) << 32 | data[0].effective; + + if ((data[0].effective & cap0) == cap0 && + (data[1].effective & cap1) == cap1) + return 0; + + data[0].effective |= cap0; + data[1].effective |= cap1; + err = capset(&hdr, data); + if (err) + return err; + + return 0; +} + +int cap_disable_effective(__u64 caps, __u64 *old_caps) +{ + struct __user_cap_data_struct data[_LINUX_CAPABILITY_U32S_3]; + struct __user_cap_header_struct hdr = { + .version = _LINUX_CAPABILITY_VERSION_3, + }; + __u32 cap0 = caps; + __u32 cap1 = caps >> 32; + int err; + + err = capget(&hdr, data); + if (err) + return err; + + if (old_caps) + *old_caps = (__u64)(data[1].effective) << 32 | data[0].effective; + + if (!(data[0].effective & cap0) && !(data[1].effective & cap1)) + return 0; + + data[0].effective &= ~cap0; + data[1].effective &= ~cap1; + err = capset(&hdr, data); + if (err) + return err; + + return 0; +} |