diff options
Diffstat (limited to 'libbb')
| -rw-r--r-- | libbb/capability.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/libbb/capability.c b/libbb/capability.c index 692024f..f60062b 100644 --- a/libbb/capability.c +++ b/libbb/capability.c @@ -6,6 +6,14 @@ //kbuild:lib-$(CONFIG_PLATFORM_LINUX) += capability.o #include <linux/capability.h> +// #include <sys/capability.h> +// This header is in libcap, but the functions are in libc. +// Comment in the header says this above capset/capget: +/* system calls - look to libc for function to system call mapping */ +extern int capset(cap_user_header_t header, cap_user_data_t data); +extern int capget(cap_user_header_t header, const cap_user_data_t data); +// so for bbox, let's just repeat the declarations. +// This way, libcap needs not be installed in build environment. #include "libbb.h" static const char *const capabilities[] = { @@ -77,3 +85,42 @@ void FAST_FUNC printf_cap(const char *pfx, unsigned cap_no) } printf("%scap_%u", pfx, cap_no); } + +DEFINE_STRUCT_CAPS; + +void FAST_FUNC getcaps(void *arg) +{ + static const uint8_t versions[] = { + _LINUX_CAPABILITY_U32S_3, /* = 2 (fits into byte) */ + _LINUX_CAPABILITY_U32S_2, /* = 2 */ + _LINUX_CAPABILITY_U32S_1, /* = 1 */ + }; + int i; + struct caps *caps = arg; + + caps->header.pid = 0; + for (i = 0; i < ARRAY_SIZE(versions); i++) { + caps->header.version = versions[i]; + if (capget(&caps->header, NULL) == 0) + goto got_it; + } + bb_simple_perror_msg_and_die("capget"); + got_it: + + switch (caps->header.version) { + case _LINUX_CAPABILITY_VERSION_1: + caps->u32s = _LINUX_CAPABILITY_U32S_1; + break; + case _LINUX_CAPABILITY_VERSION_2: + caps->u32s = _LINUX_CAPABILITY_U32S_2; + break; + case _LINUX_CAPABILITY_VERSION_3: + caps->u32s = _LINUX_CAPABILITY_U32S_3; + break; + default: + bb_error_msg_and_die("unsupported capability version"); + } + + if (capget(&caps->header, caps->data) != 0) + bb_simple_perror_msg_and_die("capget"); +} |