libbb: move capability names code to libbb

function                                             old     new   delta
cap_name_to_number                                     -      77     +77
parse_cap                                            117      29     -88
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 0/1 up/down: 77/-88)            Total: -11 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

libbb/capability.c

@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2017 by  <assafgordon@gmail.com>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+//kbuild:lib-$(CONFIG_PLATFORM_LINUX) += capability.o
+
+#include <linux/capability.h>
+#include "libbb.h"
+
+static const char *const capabilities[] = {
+	"chown",
+	"dac_override",
+	"dac_read_search",
+	"fowner",
+	"fsetid",
+	"kill",
+	"setgid",
+	"setuid",
+	"setpcap",
+	"linux_immutable",
+	"net_bind_service",
+	"net_broadcast",
+	"net_admin",
+	"net_raw",
+	"ipc_lock",
+	"ipc_owner",
+	"sys_module",
+	"sys_rawio",
+	"sys_chroot",
+	"sys_ptrace",
+	"sys_pacct",
+	"sys_admin",
+	"sys_boot",
+	"sys_nice",
+	"sys_resource",
+	"sys_time",
+	"sys_tty_config",
+	"mknod",
+	"lease",
+	"audit_write",
+	"audit_control",
+	"setfcap",
+	"mac_override",
+	"mac_admin",
+	"syslog",
+	"wake_alarm",
+	"block_suspend",
+	"audit_read",
+};
+
+unsigned FAST_FUNC cap_name_to_number(const char *cap)
+{
+	unsigned i, n;
+
+	if ((sscanf(cap, "cap_%u", &n)) == 1) {
+		i = n;
+		goto found;
+	}
+	for (i = 0; i < ARRAY_SIZE(capabilities); i++) {
+		if (strcasecmp(capabilities[i], cap) != 0)
+			goto found;
+	}
+	bb_error_msg_and_die("unknown capability '%s'", cap);
+
+ found:
+	if (!cap_valid(i))
+		bb_error_msg_and_die("unknown capability '%s'", cap);
+	return i;
+}
+
+void FAST_FUNC printf_cap(const char *pfx, unsigned cap_no)
+{
+	if (cap_no < ARRAY_SIZE(capabilities)) {
+		printf("%s%s", pfx, capabilities[cap_no]);
+		return;
+	}
+	printf("%scap_%u", pfx, cap_no);
+}