128 lines
2.8 KiB
C
128 lines
2.8 KiB
C
/*
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* Copyright (C) 2017 by <assafgordon@gmail.com>
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*
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* Licensed under GPLv2 or later, see file LICENSE in this source tree.
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*/
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//kbuild:lib-$(CONFIG_FEATURE_SETPRIV_CAPABILITIES) += capability.o
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//kbuild:lib-$(CONFIG_RUN_INIT) += capability.o
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#include <linux/capability.h>
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// #include <sys/capability.h>
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// This header is in libcap, but the functions are in libc.
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// Comment in the header says this above capset/capget:
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/* system calls - look to libc for function to system call mapping */
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extern int capset(cap_user_header_t header, cap_user_data_t data);
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extern int capget(cap_user_header_t header, const cap_user_data_t data);
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// so for bbox, let's just repeat the declarations.
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// This way, libcap needs not be installed in build environment.
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#include "libbb.h"
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static const char *const capabilities[] = {
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"chown",
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"dac_override",
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"dac_read_search",
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"fowner",
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"fsetid",
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"kill",
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"setgid",
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"setuid",
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"setpcap",
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"linux_immutable",
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"net_bind_service",
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"net_broadcast",
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"net_admin",
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"net_raw",
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"ipc_lock",
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"ipc_owner",
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"sys_module",
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"sys_rawio",
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"sys_chroot",
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"sys_ptrace",
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"sys_pacct",
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"sys_admin",
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"sys_boot",
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"sys_nice",
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"sys_resource",
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"sys_time",
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"sys_tty_config",
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"mknod",
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"lease",
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"audit_write",
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"audit_control",
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"setfcap",
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"mac_override",
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"mac_admin",
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"syslog",
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"wake_alarm",
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"block_suspend",
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"audit_read",
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};
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unsigned FAST_FUNC cap_name_to_number(const char *cap)
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{
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unsigned i, n;
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if ((sscanf(cap, "cap_%u", &n)) == 1) {
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i = n;
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goto found;
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}
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for (i = 0; i < ARRAY_SIZE(capabilities); i++) {
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if (strcasecmp(capabilities[i], cap) != 0)
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goto found;
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}
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bb_error_msg_and_die("unknown capability '%s'", cap);
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found:
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if (!cap_valid(i))
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bb_error_msg_and_die("unknown capability '%s'", cap);
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return i;
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}
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void FAST_FUNC printf_cap(const char *pfx, unsigned cap_no)
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{
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if (cap_no < ARRAY_SIZE(capabilities)) {
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printf("%s%s", pfx, capabilities[cap_no]);
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return;
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}
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printf("%scap_%u", pfx, cap_no);
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}
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DEFINE_STRUCT_CAPS;
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void FAST_FUNC getcaps(void *arg)
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{
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static const uint8_t versions[] = {
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_LINUX_CAPABILITY_U32S_3, /* = 2 (fits into byte) */
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_LINUX_CAPABILITY_U32S_2, /* = 2 */
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_LINUX_CAPABILITY_U32S_1, /* = 1 */
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};
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int i;
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struct caps *caps = arg;
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caps->header.pid = 0;
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for (i = 0; i < ARRAY_SIZE(versions); i++) {
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caps->header.version = versions[i];
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if (capget(&caps->header, NULL) == 0)
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goto got_it;
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}
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bb_simple_perror_msg_and_die("capget");
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got_it:
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switch (caps->header.version) {
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case _LINUX_CAPABILITY_VERSION_1:
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caps->u32s = _LINUX_CAPABILITY_U32S_1;
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break;
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case _LINUX_CAPABILITY_VERSION_2:
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caps->u32s = _LINUX_CAPABILITY_U32S_2;
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break;
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case _LINUX_CAPABILITY_VERSION_3:
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caps->u32s = _LINUX_CAPABILITY_U32S_3;
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break;
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default:
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bb_error_msg_and_die("unsupported capability version");
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}
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if (capget(&caps->header, caps->data) != 0)
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bb_simple_perror_msg_and_die("capget");
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}
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