/* SPDX-License-Identifier: LGPL-2.1+ */
#if defined(__i386__) || defined(__x86_64__)
#include <cpuid.h>
#endif
#include <errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "alloc-util.h"
#include "dirent-util.h"
#include "env-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "macro.h"
#include "process-util.h"
#include "stat-util.h"
#include "string-table.h"
#include "string-util.h"
#include "virt.h"
static int detect_vm_cpuid(void) {
/* CPUID is an x86 specific interface. */
#if defined(__i386__) || defined(__x86_64__)
static const struct {
const char *cpuid;
int id;
} cpuid_vendor_table[] = {
{ "XenVMMXenVMM", VIRTUALIZATION_XEN },
{ "KVMKVMKVM", VIRTUALIZATION_KVM },
{ "TCGTCGTCGTCG", VIRTUALIZATION_QEMU },
/* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
{ "VMwareVMware", VIRTUALIZATION_VMWARE },
/* https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs */
{ "Microsoft Hv", VIRTUALIZATION_MICROSOFT },
/* https://wiki.freebsd.org/bhyve */
{ "bhyve bhyve ", VIRTUALIZATION_BHYVE },
{ "QNXQVMBSQG", VIRTUALIZATION_QNX },
};
uint32_t eax, ebx, ecx, edx;
bool hypervisor;
/* http://lwn.net/Articles/301888/ */
/* First detect whether there is a hypervisor */
if (__get_cpuid(1, &eax, &ebx, &ecx, &edx) == 0)
return VIRTUALIZATION_NONE;
hypervisor = ecx & 0x80000000U;
if (hypervisor) {
union {
uint32_t sig32[3];
char text[13];
} sig = {};
unsigned j;
/* There is a hypervisor, see what it is */
__cpuid(0x40000000U, eax, ebx, ecx, edx);
sig.sig32[0] = ebx;
sig.sig32[1] = ecx;
sig.sig32[2] = edx;
log_debug("Virtualization found, CPUID=%s", sig.text);
for (j = 0; j < ELEMENTSOF(cpuid_vendor_table); j ++)
if (streq(sig.text, cpuid_vendor_table[j].cpuid))
return cpuid_vendor_table[j].id;
return VIRTUALIZATION_VM_OTHER;
}
#endif
log_debug("No virtualization found in CPUID");
return VIRTUALIZATION_NONE;
}
static int detect_vm_device_tree(void) {
#if defined(__arm__) || defined(__aarch64__) || defined(__powerpc__) || defined(__powerpc64__)
_cleanup_free_ char *hvtype = NULL;
int r;
r = read_one_line_file("/proc/device-tree/hypervisor/compatible", &hvtype);
if (r == -ENOENT) {
_cleanup_closedir_ DIR *dir = NULL;
struct dirent *dent;
dir = opendir("/proc/device-tree");
if (!dir) {
if (errno == ENOENT) {
log_debug_errno(errno, "/proc/device-tree: %m");
return VIRTUALIZATION_NONE;
}
return -errno;
}
FOREACH_DIRENT(dent, dir, return -errno)
if (strstr(dent->d_name, "fw-cfg")) {
log_debug("Virtualization QEMU: \"fw-cfg\" present in /proc/device-tree/%s", dent->d_name);
return VIRTUALIZATION_QEMU;
}
log_debug("No virtualization found in /proc/device-tree/*");
return VIRTUALIZATION_NONE;
} else if (r < 0)
return r;
log_debug("Virtualization %s found in /proc/device-tree/hypervisor/compatible", hvtype);
if (streq(hvtype, "linux,kvm"))
return VIRTUALIZATION_KVM;
else if (strstr(hvtype, "xen"))
return VIRTUALIZATION_XEN;
else
return VIRTUALIZATION_VM_OTHER;
#else
log_debug("This platform does not support /proc/device-tree");
return VIRTUALIZATION_NONE;
#endif
}
static int detect_vm_dmi(void) {
#if defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__aarch64__)
static const char *const dmi_vendors[] = {
"/sys/class/dmi/id/product_name", /* Test this before sys_vendor to detect KVM over QEMU */
"/sys/class/dmi/id/sys_vendor",
"/sys/class/dmi/id/board_vendor",
"/sys/class/dmi/id/bios_vendor"
};
static const struct {
const char *vendor;
int id;
} dmi_vendor_table[] = {
{ "KVM", VIRTUALIZATION_KVM },
{ "QEMU", VIRTUALIZATION_QEMU },
/* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
{ "VMware", VIRTUALIZATION_VMWARE },
{ "VMW", VIRTUALIZATION_VMWARE },
{ "innotek GmbH", VIRTUALIZATION_ORACLE },
{ "Xen", VIRTUALIZATION_XEN },
{ "Bochs", VIRTUALIZATION_BOCHS },
{ "Parallels", VIRTUALIZATION_PARALLELS },
/* https://wiki.freebsd.org/bhyve */
{ "BHYVE", VIRTUALIZATION_BHYVE },
};
unsigned i;
int r;
for (i = 0; i < ELEMENTSOF(dmi_vendors); i++) {
_cleanup_free_ char *s = NULL;
unsigned j;
r = read_one_line_file(dmi_vendors[i], &s);
if (r < 0) {
if (r == -ENOENT)
continue;
return r;
}
for (j = 0; j < ELEMENTSOF(dmi_vendor_table); j++)
if (startswith(s, dmi_vendor_table[j].vendor)) {
log_debug("Virtualization %s found in DMI (%s)", s, dmi_vendors[i]);
return dmi_vendor_table[j].id;
}
}
#endif
log_debug("No virtualization found in DMI");
return VIRTUALIZATION_NONE;
}
static int detect_vm_xen(void) {
/* Check for Dom0 will be executed later in detect_vm_xen_dom0
The presence of /proc/xen indicates some form of a Xen domain */
if (access("/proc/xen", F_OK) < 0) {
log_debug("Virtualization XEN not found, /proc/xen does not exist");
return VIRTUALIZATION_NONE;
}
log_debug("Virtualization XEN found (/proc/xen exists)");
return VIRTUALIZATION_XEN;
}
#define XENFEAT_dom0 11 /* xen/include/public/features.h */
#define PATH_FEATURES "/sys/hypervisor/properties/features"
/* Returns -errno, or 0 for domU, or 1 for dom0 */
static int detect_vm_xen_dom0(void) {
_cleanup_free_ char *domcap = NULL;
char *cap, *i;
int r;
r = read_one_line_file(PATH_FEATURES, &domcap);
if (r < 0 && r != -ENOENT)
return r;
if (r == 0) {
unsigned long features;
/* Here, we need to use sscanf() instead of safe_atoul()
* as the string lacks the leading "0x". */
r = sscanf(domcap, "%lx", &features);
if (r == 1) {
r = !!(features & (1U << XENFEAT_dom0));
log_debug("Virtualization XEN, found %s with value %08lx, "
"XENFEAT_dom0 (indicating the 'hardware domain') is%s set.",
PATH_FEATURES, features, r ? "" : " not");
return r;
}
log_debug("Virtualization XEN, found %s, unhandled content '%s'",
PATH_FEATURES, domcap);
}
r = read_one_line_file("/proc/xen/capabilities", &domcap);
if (r == -ENOENT) {
log_debug("Virtualization XEN because /proc/xen/capabilities does not exist");
return 0;
}
if (r < 0)
return r;
i = domcap;
while ((cap = strsep(&i, ",")))
if (streq(cap, "control_d"))
break;
if (!cap) {
log_debug("Virtualization XEN DomU found (/proc/xen/capabilites)");
return 0;
}
log_debug("Virtualization XEN Dom0 ignored (/proc/xen/capabilities)");
return 1;
}
static int detect_vm_hypervisor(void) {
_cleanup_free_ char *hvtype = NULL;
int r;
r = read_one_line_file("/sys/hypervisor/type", &hvtype);
if (r == -ENOENT)
return VIRTUALIZATION_NONE;
if (r < 0)
return r;
log_debug("Virtualization %s found in /sys/hypervisor/type", hvtype);
if (streq(hvtype, "xen"))
return VIRTUALIZATION_XEN;
else
return VIRTUALIZATION_VM_OTHER;
}
static int detect_vm_uml(void) {
_cleanup_free_ char *cpuinfo_contents = NULL;
int r;
/* Detect User-Mode Linux by reading /proc/cpuinfo */
r = read_full_file("/proc/cpuinfo", &cpuinfo_contents, NULL);
if (r == -ENOENT) {
log_debug("/proc/cpuinfo not found, assuming no UML virtualization.");
return VIRTUALIZATION_NONE;
}
if (r < 0)
return r;
if (strstr(cpuinfo_contents, "\nvendor_id\t: User Mode Linux\n")) {
log_debug("UML virtualization found in /proc/cpuinfo");
return VIRTUALIZATION_UML;
}
log_debug("UML virtualization not found in /proc/cpuinfo.");
return VIRTUALIZATION_NONE;
}
static int detect_vm_zvm(void) {
#if defined(__s390__)
_cleanup_free_ char *t = NULL;
int r;
r = get_proc_field("/proc/sysinfo", "VM00 Control Program", WHITESPACE, &t);
if (r == -ENOENT)
return VIRTUALIZATION_NONE;
if (r < 0)
return r;
log_debug("Virtualization %s found in /proc/sysinfo", t);
if (streq(t, "z/VM"))
return VIRTUALIZATION_ZVM;
else
return VIRTUALIZATION_KVM;
#else
log_debug("This platform does not support /proc/sysinfo");
return VIRTUALIZATION_NONE;
#endif
}
/* Returns a short identifier for the various VM implementations */
int detect_vm(void) {
static thread_local int cached_found = _VIRTUALIZATION_INVALID;
bool other = false;
int r, dmi;
if (cached_found >= 0)
return cached_found;
/* We have to use the correct order here:
*
* → First, try to detect Oracle Virtualbox, even if it uses KVM, as well as Xen even if it cloaks as Microsoft
* Hyper-V.
*
* → Second, try to detect from CPUID, this will report KVM for whatever software is used even if info in DMI is
* overwritten.
*
* → Third, try to detect from DMI. */
dmi = detect_vm_dmi();
if (IN_SET(dmi, VIRTUALIZATION_ORACLE, VIRTUALIZATION_XEN)) {
r = dmi;
goto finish;
}
r = detect_vm_cpuid();
if (r < 0)
return r;
if (r == VIRTUALIZATION_VM_OTHER)
other = true;
else if (r != VIRTUALIZATION_NONE)
goto finish;
/* Now, let's get back to DMI */
if (dmi < 0)
return dmi;
if (dmi == VIRTUALIZATION_VM_OTHER)
other = true;
else if (dmi != VIRTUALIZATION_NONE) {
r = dmi;
goto finish;
}
/* x86 xen will most likely be detected by cpuid. If not (most likely
* because we're not an x86 guest), then we should try the /proc/xen
* directory next. If that's not found, then we check for the high-level
* hypervisor sysfs file.
*/
r = detect_vm_xen();
if (r < 0)
return r;
if (r == VIRTUALIZATION_VM_OTHER)
other = true;
else if (r != VIRTUALIZATION_NONE)
goto finish;
r = detect_vm_hypervisor();
if (r < 0)
return r;
if (r == VIRTUALIZATION_VM_OTHER)
other = true;
else if (r != VIRTUALIZATION_NONE)
goto finish;
r = detect_vm_device_tree();
if (r < 0)
return r;
if (r == VIRTUALIZATION_VM_OTHER)
other = true;
else if (r != VIRTUALIZATION_NONE)
goto finish;
r = detect_vm_uml();
if (r < 0)
return r;
if (r == VIRTUALIZATION_VM_OTHER)
other = true;
else if (r != VIRTUALIZATION_NONE)
goto finish;
r = detect_vm_zvm();
if (r < 0)
return r;
finish:
/* x86 xen Dom0 is detected as XEN in hypervisor and maybe others.
* In order to detect the Dom0 as not virtualization we need to
* double-check it */
if (r == VIRTUALIZATION_XEN) {
int dom0;
dom0 = detect_vm_xen_dom0();
if (dom0 < 0)
return dom0;
if (dom0 > 0)
r = VIRTUALIZATION_NONE;
} else if (r == VIRTUALIZATION_NONE && other)
r = VIRTUALIZATION_VM_OTHER;
cached_found = r;
log_debug("Found VM virtualization %s", virtualization_to_string(r));
return r;
}
int detect_container(void) {
static const struct {
const char *value;
int id;
} value_table[] = {
{ "lxc", VIRTUALIZATION_LXC },
{ "lxc-libvirt", VIRTUALIZATION_LXC_LIBVIRT },
{ "systemd-nspawn", VIRTUALIZATION_SYSTEMD_NSPAWN },
{ "docker", VIRTUALIZATION_DOCKER },
{ "rkt", VIRTUALIZATION_RKT },
};
static thread_local int cached_found = _VIRTUALIZATION_INVALID;
_cleanup_free_ char *m = NULL;
const char *e = NULL;
unsigned j;
int r;
if (cached_found >= 0)
return cached_found;
/* /proc/vz exists in container and outside of the container, /proc/bc only outside of the container. */
if (access("/proc/vz", F_OK) >= 0 &&
access("/proc/bc", F_OK) < 0) {
r = VIRTUALIZATION_OPENVZ;
goto finish;
}
if (getpid_cached() == 1) {
/* If we are PID 1 we can just check our own environment variable, and that's authoritative. */
e = getenv("container");
if (isempty(e)) {
r = VIRTUALIZATION_NONE;
goto finish;
}
goto translate_name;
}
/* Otherwise, PID 1 might have dropped this information into a file in /run. This is better than accessing
* /proc/1/environ, since we don't need CAP_SYS_PTRACE for that. */
r = read_one_line_file("/run/systemd/container", &m);
if (r >= 0) {
e = m;
goto translate_name;
}
if (r != -ENOENT)
return log_debug_errno(r, "Failed to read /run/systemd/container: %m");
/* Fallback for cases where PID 1 was not systemd (for example, cases where init=/bin/sh is used. */
r = getenv_for_pid(1, "container", &m);
if (r > 0) {
e = m;
goto translate_name;
}
if (r < 0) /* This only works if we have CAP_SYS_PTRACE, hence let's better ignore failures here */
log_debug_errno(r, "Failed to read $container of PID 1, ignoring: %m");
/* Interestingly /proc/1/sched actually shows the host's PID for what we see as PID 1. Hence, if the PID shown
* there is not 1, we know we are in a PID namespace. and hence a container. */
r = read_one_line_file("/proc/1/sched", &m);
if (r >= 0) {
const char *t;
t = strrchr(m, '(');
if (!t)
return -EIO;
if (!startswith(t, "(1,")) {
r = VIRTUALIZATION_CONTAINER_OTHER;
goto finish;
}
} else if (r != -ENOENT)
return r;
/* If that didn't work, give up, assume no container manager. */
r = VIRTUALIZATION_NONE;
goto finish;
translate_name:
for (j = 0; j < ELEMENTSOF(value_table); j++)
if (streq(e, value_table[j].value)) {
r = value_table[j].id;
goto finish;
}
r = VIRTUALIZATION_CONTAINER_OTHER;
finish:
log_debug("Found container virtualization %s.", virtualization_to_string(r));
cached_found = r;
return r;
}
int detect_virtualization(void) {
int r;
r = detect_container();
if (r == 0)
r = detect_vm();
return r;
}
static int userns_has_mapping(const char *name) {
_cleanup_fclose_ FILE *f = NULL;
_cleanup_free_ char *buf = NULL;
size_t n_allocated = 0;
ssize_t n;
uint32_t a, b, c;
int r;
f = fopen(name, "re");
if (!f) {
log_debug_errno(errno, "Failed to open %s: %m", name);
return errno == ENOENT ? false : -errno;
}
n = getline(&buf, &n_allocated, f);
if (n < 0) {
if (feof(f)) {
log_debug("%s is empty, we're in an uninitialized user namespace", name);
return true;
}
return log_debug_errno(errno, "Failed to read %s: %m", name);
}
r = sscanf(buf, "%"PRIu32" %"PRIu32" %"PRIu32, &a, &b, &c);
if (r < 3)
return log_debug_errno(errno, "Failed to parse %s: %m", name);
if (a == 0 && b == 0 && c == UINT32_MAX) {
/* The kernel calls mappings_overlap() and does not allow overlaps */
log_debug("%s has a full 1:1 mapping", name);
return false;
}
/* Anything else implies that we are in a user namespace */
log_debug("Mapping found in %s, we're in a user namespace", name);
return true;
}
int running_in_userns(void) {
_cleanup_free_ char *line = NULL;
int r;
r = userns_has_mapping("/proc/self/uid_map");
if (r != 0)
return r;
r = userns_has_mapping("/proc/self/gid_map");
if (r != 0)
return r;
/* "setgroups" file was added in kernel v3.18-rc6-15-g9cc46516dd. It is also
* possible to compile a kernel without CONFIG_USER_NS, in which case "setgroups"
* also does not exist. We cannot distinguish those two cases, so assume that
* we're running on a stripped-down recent kernel, rather than on an old one,
* and if the file is not found, return false.
*/
r = read_one_line_file("/proc/self/setgroups", &line);
if (r < 0) {
log_debug_errno(r, "/proc/self/setgroups: %m");
return r == -ENOENT ? false : r;
}
truncate_nl(line);
r = streq(line, "deny");
/* See user_namespaces(7) for a description of this "setgroups" contents. */
log_debug("/proc/self/setgroups contains \"%s\", %s user namespace", line, r ? "in" : "not in");
return r;
}
int running_in_chroot(void) {
int r;
if (getenv_bool("SYSTEMD_IGNORE_CHROOT") > 0)
return 0;
r = files_same("/proc/1/root", "/", 0);
if (r < 0)
return r;
return r == 0;
}
static const char *const virtualization_table[_VIRTUALIZATION_MAX] = {
[VIRTUALIZATION_NONE] = "none",
[VIRTUALIZATION_KVM] = "kvm",
[VIRTUALIZATION_QEMU] = "qemu",
[VIRTUALIZATION_BOCHS] = "bochs",
[VIRTUALIZATION_XEN] = "xen",
[VIRTUALIZATION_UML] = "uml",
[VIRTUALIZATION_VMWARE] = "vmware",
[VIRTUALIZATION_ORACLE] = "oracle",
[VIRTUALIZATION_MICROSOFT] = "microsoft",
[VIRTUALIZATION_ZVM] = "zvm",
[VIRTUALIZATION_PARALLELS] = "parallels",
[VIRTUALIZATION_BHYVE] = "bhyve",
[VIRTUALIZATION_QNX] = "qnx",
[VIRTUALIZATION_VM_OTHER] = "vm-other",
[VIRTUALIZATION_SYSTEMD_NSPAWN] = "systemd-nspawn",
[VIRTUALIZATION_LXC_LIBVIRT] = "lxc-libvirt",
[VIRTUALIZATION_LXC] = "lxc",
[VIRTUALIZATION_OPENVZ] = "openvz",
[VIRTUALIZATION_DOCKER] = "docker",
[VIRTUALIZATION_RKT] = "rkt",
[VIRTUALIZATION_CONTAINER_OTHER] = "container-other",
};
DEFINE_STRING_TABLE_LOOKUP(virtualization, int);