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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-10 20:49:52 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-10 20:49:52 +0000
commit55944e5e40b1be2afc4855d8d2baf4b73d1876b5 (patch)
tree33f869f55a1b149e9b7c2b7e201867ca5dd52992 /src/basic/virt.c
parentInitial commit. (diff)
downloadsystemd-55944e5e40b1be2afc4855d8d2baf4b73d1876b5.tar.xz
systemd-55944e5e40b1be2afc4855d8d2baf4b73d1876b5.zip
Adding upstream version 255.4.upstream/255.4
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/basic/virt.c')
-rw-r--r--src/basic/virt.c1071
1 files changed, 1071 insertions, 0 deletions
diff --git a/src/basic/virt.c b/src/basic/virt.c
new file mode 100644
index 0000000..93ccfaa
--- /dev/null
+++ b/src/basic/virt.c
@@ -0,0 +1,1071 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#if defined(__i386__) || defined(__x86_64__)
+#include <cpuid.h>
+#endif
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "cgroup-util.h"
+#include "dirent-util.h"
+#include "env-util.h"
+#include "errno-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "macro.h"
+#include "missing_threads.h"
+#include "process-util.h"
+#include "stat-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "virt.h"
+
+enum {
+ SMBIOS_VM_BIT_SET,
+ SMBIOS_VM_BIT_UNSET,
+ SMBIOS_VM_BIT_UNKNOWN,
+};
+
+static Virtualization detect_vm_cpuid(void) {
+
+ /* CPUID is an x86 specific interface. */
+#if defined(__i386__) || defined(__x86_64__)
+
+ static const struct {
+ const char sig[13];
+ Virtualization id;
+ } vm_table[] = {
+ { "XenVMMXenVMM", VIRTUALIZATION_XEN },
+ { "KVMKVMKVM", VIRTUALIZATION_KVM }, /* qemu with KVM */
+ { "Linux KVM Hv", VIRTUALIZATION_KVM }, /* qemu with KVM + HyperV Enlightenments */
+ { "TCGTCGTCGTCG", VIRTUALIZATION_QEMU }, /* qemu without KVM */
+ /* 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 },
+ /* https://projectacrn.org */
+ { "ACRNACRNACRN", VIRTUALIZATION_ACRN },
+ /* https://www.lockheedmartin.com/en-us/products/Hardened-Security-for-Intel-Processors.html */
+ { "SRESRESRESRE", VIRTUALIZATION_SRE },
+ { "Apple VZ", VIRTUALIZATION_APPLE },
+ };
+
+ 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 = {};
+
+ /* 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 (size_t i = 0; i < ELEMENTSOF(vm_table); i++)
+ if (memcmp_nn(sig.text, sizeof(sig.text),
+ vm_table[i].sig, sizeof(vm_table[i].sig)) == 0)
+ return vm_table[i].id;
+
+ log_debug("Unknown virtualization with CPUID=%s. Add to vm_table[]?", sig.text);
+ return VIRTUALIZATION_VM_OTHER;
+ }
+#endif
+ log_debug("No virtualization found in CPUID");
+
+ return VIRTUALIZATION_NONE;
+}
+
+static Virtualization detect_vm_device_tree(void) {
+#if defined(__arm__) || defined(__aarch64__) || defined(__powerpc__) || defined(__powerpc64__) || defined(__riscv)
+ _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;
+ _cleanup_free_ char *compat = NULL;
+
+ if (access("/proc/device-tree/ibm,partition-name", F_OK) == 0 &&
+ access("/proc/device-tree/hmc-managed?", F_OK) == 0 &&
+ access("/proc/device-tree/chosen/qemu,graphic-width", F_OK) != 0)
+ return VIRTUALIZATION_POWERVM;
+
+ 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(de, dir, return -errno)
+ if (strstr(de->d_name, "fw-cfg")) {
+ log_debug("Virtualization QEMU: \"fw-cfg\" present in /proc/device-tree/%s", de->d_name);
+ return VIRTUALIZATION_QEMU;
+ }
+
+ r = read_one_line_file("/proc/device-tree/compatible", &compat);
+ if (r < 0 && r != -ENOENT)
+ return r;
+ if (r >= 0 && streq(compat, "qemu,pseries")) {
+ log_debug("Virtualization %s found in /proc/device-tree/compatible", compat);
+ 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 if (strstr(hvtype, "vmware"))
+ return VIRTUALIZATION_VMWARE;
+ else
+ return VIRTUALIZATION_VM_OTHER;
+#else
+ log_debug("This platform does not support /proc/device-tree");
+ return VIRTUALIZATION_NONE;
+#endif
+}
+
+#if defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) || defined(__loongarch_lp64) || defined(__riscv)
+static Virtualization detect_vm_dmi_vendor(void) {
+ 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",
+ "/sys/class/dmi/id/product_version", /* For Hyper-V VMs test */
+ NULL
+ };
+
+ static const struct {
+ const char *vendor;
+ Virtualization id;
+ } dmi_vendor_table[] = {
+ { "KVM", VIRTUALIZATION_KVM },
+ { "OpenStack", VIRTUALIZATION_KVM }, /* Detect OpenStack instance as KVM in non x86 architecture */
+ { "KubeVirt", VIRTUALIZATION_KVM }, /* Detect KubeVirt instance as KVM in non x86 architecture */
+ { "Amazon EC2", VIRTUALIZATION_AMAZON },
+ { "QEMU", VIRTUALIZATION_QEMU },
+ { "VMware", VIRTUALIZATION_VMWARE }, /* https://kb.vmware.com/s/article/1009458 */
+ { "VMW", VIRTUALIZATION_VMWARE },
+ { "innotek GmbH", VIRTUALIZATION_ORACLE },
+ { "VirtualBox", VIRTUALIZATION_ORACLE },
+ { "Xen", VIRTUALIZATION_XEN },
+ { "Bochs", VIRTUALIZATION_BOCHS },
+ { "Parallels", VIRTUALIZATION_PARALLELS },
+ /* https://wiki.freebsd.org/bhyve */
+ { "BHYVE", VIRTUALIZATION_BHYVE },
+ { "Hyper-V", VIRTUALIZATION_MICROSOFT },
+ { "Apple Virtualization", VIRTUALIZATION_APPLE },
+ { "Google Compute Engine", VIRTUALIZATION_GOOGLE }, /* https://cloud.google.com/run/docs/container-contract#sandbox */
+ };
+ int r;
+
+ STRV_FOREACH(vendor, dmi_vendors) {
+ _cleanup_free_ char *s = NULL;
+
+ r = read_one_line_file(*vendor, &s);
+ if (r < 0) {
+ if (r == -ENOENT)
+ continue;
+
+ return r;
+ }
+
+ for (size_t i = 0; i < ELEMENTSOF(dmi_vendor_table); i++)
+ if (startswith(s, dmi_vendor_table[i].vendor)) {
+ log_debug("Virtualization %s found in DMI (%s)", s, *vendor);
+ return dmi_vendor_table[i].id;
+ }
+ }
+ log_debug("No virtualization found in DMI vendor table.");
+ return VIRTUALIZATION_NONE;
+}
+
+static int detect_vm_smbios(void) {
+ /* The SMBIOS BIOS Characteristics Extension Byte 2 (Section 2.1.2.2 of
+ * https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_3.4.0.pdf), specifies that
+ * the 4th bit being set indicates a VM. The BIOS Characteristics table is exposed via the kernel in
+ * /sys/firmware/dmi/entries/0-0. Note that in the general case, this bit being unset should not
+ * imply that the system is running on bare-metal. For example, QEMU 3.1.0 (with or without KVM)
+ * with SeaBIOS does not set this bit. */
+ _cleanup_free_ char *s = NULL;
+ size_t readsize;
+ int r;
+
+ r = read_full_virtual_file("/sys/firmware/dmi/entries/0-0/raw", &s, &readsize);
+ if (r < 0) {
+ log_debug_errno(r, "Unable to read /sys/firmware/dmi/entries/0-0/raw, "
+ "using the virtualization information found in DMI vendor table, ignoring: %m");
+ return SMBIOS_VM_BIT_UNKNOWN;
+ }
+ if (readsize < 20 || s[1] < 20) {
+ /* The spec indicates that byte 1 contains the size of the table, 0x12 + the number of
+ * extension bytes. The data we're interested in is in extension byte 2, which would be at
+ * 0x13. If we didn't read that much data, or if the BIOS indicates that we don't have that
+ * much data, we don't infer anything from the SMBIOS. */
+ log_debug("Only read %zu bytes from /sys/firmware/dmi/entries/0-0/raw (expected 20). "
+ "Using the virtualization information found in DMI vendor table.", readsize);
+ return SMBIOS_VM_BIT_UNKNOWN;
+ }
+
+ uint8_t byte = (uint8_t) s[19];
+ if (byte & (1U<<4)) {
+ log_debug("DMI BIOS Extension table indicates virtualization.");
+ return SMBIOS_VM_BIT_SET;
+ }
+ log_debug("DMI BIOS Extension table does not indicate virtualization.");
+ return SMBIOS_VM_BIT_UNSET;
+}
+#endif /* defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) || defined(__loongarch_lp64) */
+
+static Virtualization detect_vm_dmi(void) {
+#if defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) || defined(__loongarch_lp64)
+
+ int r;
+ r = detect_vm_dmi_vendor();
+
+ /* The DMI vendor tables in /sys/class/dmi/id don't help us distinguish between Amazon EC2
+ * virtual machines and bare-metal instances, so we need to look at SMBIOS. */
+ if (r == VIRTUALIZATION_AMAZON) {
+ switch (detect_vm_smbios()) {
+ case SMBIOS_VM_BIT_SET:
+ return VIRTUALIZATION_AMAZON;
+ case SMBIOS_VM_BIT_UNSET:
+ return VIRTUALIZATION_NONE;
+ case SMBIOS_VM_BIT_UNKNOWN: {
+ /* The DMI information we are after is only accessible to the root user,
+ * so we fallback to using the product name which is less restricted
+ * to distinguish metal systems from virtualized instances */
+ _cleanup_free_ char *s = NULL;
+ const char *e;
+
+ r = read_full_virtual_file("/sys/class/dmi/id/product_name", &s, NULL);
+ /* In EC2, virtualized is much more common than metal, so if for some reason
+ * we fail to read the DMI data, assume we are virtualized. */
+ if (r < 0) {
+ log_debug_errno(r, "Can't read /sys/class/dmi/id/product_name,"
+ " assuming virtualized: %m");
+ return VIRTUALIZATION_AMAZON;
+ }
+ e = strstrafter(truncate_nl(s), ".metal");
+ if (e && IN_SET(*e, 0, '-')) {
+ log_debug("DMI product name has '.metal', assuming no virtualization");
+ return VIRTUALIZATION_NONE;
+ } else
+ return VIRTUALIZATION_AMAZON;
+ }
+ default:
+ assert_not_reached();
+ }
+ }
+
+ /* If we haven't identified a VM, but the firmware indicates that there is one, indicate as much. We
+ * have no further information about what it is. */
+ if (r == VIRTUALIZATION_NONE && detect_vm_smbios() == SMBIOS_VM_BIT_SET)
+ return VIRTUALIZATION_VM_OTHER;
+ return r;
+#else
+ return VIRTUALIZATION_NONE;
+#endif
+}
+
+#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;
+ 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;
+
+ for (const char *i = domcap;;) {
+ _cleanup_free_ char *cap = NULL;
+
+ r = extract_first_word(&i, &cap, ",", 0);
+ if (r < 0)
+ return r;
+ if (r == 0) {
+ log_debug("Virtualization XEN DomU found (/proc/xen/capabilities)");
+ return 0;
+ }
+
+ if (streq(cap, "control_d")) {
+ log_debug("Virtualization XEN Dom0 ignored (/proc/xen/capabilities)");
+ return 1;
+ }
+ }
+}
+
+static Virtualization detect_vm_xen(void) {
+ /* The presence of /proc/xen indicates some form of a Xen domain
+ The check for Dom0 is handled outside this function */
+ 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;
+}
+
+static Virtualization 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 Virtualization detect_vm_uml(void) {
+ _cleanup_fclose_ FILE *f = NULL;
+ int r;
+
+ /* Detect User-Mode Linux by reading /proc/cpuinfo */
+ f = fopen("/proc/cpuinfo", "re");
+ if (!f) {
+ if (errno == ENOENT) {
+ log_debug("/proc/cpuinfo not found, assuming no UML virtualization.");
+ return VIRTUALIZATION_NONE;
+ }
+ return -errno;
+ }
+
+ for (;;) {
+ _cleanup_free_ char *line = NULL;
+ const char *t;
+
+ r = read_line(f, LONG_LINE_MAX, &line);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ break;
+
+ t = startswith(line, "vendor_id\t: ");
+ if (t) {
+ if (startswith(t, "User Mode Linux")) {
+ log_debug("UML virtualization found in /proc/cpuinfo");
+ return VIRTUALIZATION_UML;
+ }
+
+ break;
+ }
+ }
+
+ log_debug("UML virtualization not found in /proc/cpuinfo.");
+ return VIRTUALIZATION_NONE;
+}
+
+static Virtualization 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 */
+Virtualization detect_vm(void) {
+ static thread_local Virtualization cached_found = _VIRTUALIZATION_INVALID;
+ bool other = false;
+ int xen_dom0 = 0;
+ Virtualization v, dmi;
+
+ if (cached_found >= 0)
+ return cached_found;
+
+ /* We have to use the correct order here:
+ *
+ * → First, try to detect Oracle Virtualbox, Amazon EC2 Nitro, Parallels, and Google Compute Engine, even if they use KVM,
+ * as well as Xen even if it cloaks as Microsoft Hyper-V. Attempt to detect uml at this stage also
+ * since it runs as a user-process nested inside other VMs. Also check for Xen now, because Xen PV
+ * mode does not override CPUID when nested inside another hypervisor.
+ *
+ * → 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,
+ VIRTUALIZATION_AMAZON,
+ VIRTUALIZATION_PARALLELS,
+ VIRTUALIZATION_GOOGLE)) {
+ v = dmi;
+ goto finish;
+ }
+
+ /* Detect UML */
+ v = detect_vm_uml();
+ if (v < 0)
+ return v;
+ if (v != VIRTUALIZATION_NONE)
+ goto finish;
+
+ /* Detect Xen */
+ v = detect_vm_xen();
+ if (v < 0)
+ return v;
+ if (v == VIRTUALIZATION_XEN) {
+ /* If we are Dom0, then we expect to not report as a VM. However, as we might be nested
+ * inside another hypervisor which can be detected via the CPUID check, wait to report this
+ * until after the CPUID check. */
+ xen_dom0 = detect_vm_xen_dom0();
+ if (xen_dom0 < 0)
+ return xen_dom0;
+ if (xen_dom0 == 0)
+ goto finish;
+ } else if (v != VIRTUALIZATION_NONE)
+ assert_not_reached();
+
+ /* Detect from CPUID */
+ v = detect_vm_cpuid();
+ if (v < 0)
+ return v;
+ if (v == VIRTUALIZATION_VM_OTHER)
+ other = true;
+ else if (v != VIRTUALIZATION_NONE)
+ goto finish;
+
+ /* If we are in Dom0 and have not yet finished, finish with the result of detect_vm_cpuid */
+ if (xen_dom0 > 0)
+ 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) {
+ v = dmi;
+ goto finish;
+ }
+
+ /* Check high-level hypervisor sysfs file */
+ v = detect_vm_hypervisor();
+ if (v < 0)
+ return v;
+ if (v == VIRTUALIZATION_VM_OTHER)
+ other = true;
+ else if (v != VIRTUALIZATION_NONE)
+ goto finish;
+
+ v = detect_vm_device_tree();
+ if (v < 0)
+ return v;
+ if (v == VIRTUALIZATION_VM_OTHER)
+ other = true;
+ else if (v != VIRTUALIZATION_NONE)
+ goto finish;
+
+ v = detect_vm_zvm();
+ if (v < 0)
+ return v;
+
+finish:
+ if (v == VIRTUALIZATION_NONE && other)
+ v = VIRTUALIZATION_VM_OTHER;
+
+ cached_found = v;
+ log_debug("Found VM virtualization %s", virtualization_to_string(v));
+ return v;
+}
+
+static const char *const container_table[_VIRTUALIZATION_MAX] = {
+ [VIRTUALIZATION_LXC] = "lxc",
+ [VIRTUALIZATION_LXC_LIBVIRT] = "lxc-libvirt",
+ [VIRTUALIZATION_SYSTEMD_NSPAWN] = "systemd-nspawn",
+ [VIRTUALIZATION_DOCKER] = "docker",
+ [VIRTUALIZATION_PODMAN] = "podman",
+ [VIRTUALIZATION_RKT] = "rkt",
+ [VIRTUALIZATION_WSL] = "wsl",
+ [VIRTUALIZATION_PROOT] = "proot",
+ [VIRTUALIZATION_POUCH] = "pouch",
+};
+
+DEFINE_PRIVATE_STRING_TABLE_LOOKUP_FROM_STRING(container, int);
+
+static int running_in_cgroupns(void) {
+ int r;
+
+ if (!cg_ns_supported())
+ return false;
+
+ r = cg_all_unified();
+ if (r < 0)
+ return r;
+
+ if (r) {
+ /* cgroup v2 */
+
+ r = access("/sys/fs/cgroup/cgroup.events", F_OK);
+ if (r < 0) {
+ if (errno != ENOENT)
+ return -errno;
+ /* All kernel versions have cgroup.events in nested cgroups. */
+ return false;
+ }
+
+ /* There's no cgroup.type in the root cgroup, and future kernel versions
+ * are unlikely to add it since cgroup.type is something that makes no sense
+ * whatsoever in the root cgroup. */
+ r = access("/sys/fs/cgroup/cgroup.type", F_OK);
+ if (r == 0)
+ return true;
+ if (r < 0 && errno != ENOENT)
+ return -errno;
+
+ /* On older kernel versions, there's no cgroup.type */
+ r = access("/sys/kernel/cgroup/features", F_OK);
+ if (r < 0) {
+ if (errno != ENOENT)
+ return -errno;
+ /* This is an old kernel that we know for sure has cgroup.events
+ * only in nested cgroups. */
+ return true;
+ }
+
+ /* This is a recent kernel, and cgroup.type doesn't exist, so we must be
+ * in the root cgroup. */
+ return false;
+ } else {
+ /* cgroup v1 */
+
+ /* If systemd controller is not mounted, do not even bother. */
+ r = access("/sys/fs/cgroup/systemd", F_OK);
+ if (r < 0) {
+ if (errno != ENOENT)
+ return -errno;
+ return false;
+ }
+
+ /* release_agent only exists in the root cgroup. */
+ r = access("/sys/fs/cgroup/systemd/release_agent", F_OK);
+ if (r < 0) {
+ if (errno != ENOENT)
+ return -errno;
+ return true;
+ }
+
+ return false;
+ }
+}
+
+static Virtualization detect_container_files(void) {
+ static const struct {
+ const char *file_path;
+ Virtualization id;
+ } container_file_table[] = {
+ /* https://github.com/containers/podman/issues/6192 */
+ /* https://github.com/containers/podman/issues/3586#issuecomment-661918679 */
+ { "/run/.containerenv", VIRTUALIZATION_PODMAN },
+ /* https://github.com/moby/moby/issues/18355 */
+ /* Docker must be the last in this table, see below. */
+ { "/.dockerenv", VIRTUALIZATION_DOCKER },
+ };
+
+ for (size_t i = 0; i < ELEMENTSOF(container_file_table); i++) {
+ if (access(container_file_table[i].file_path, F_OK) >= 0)
+ return container_file_table[i].id;
+
+ if (errno != ENOENT)
+ log_debug_errno(errno,
+ "Checking if %s exists failed, ignoring: %m",
+ container_file_table[i].file_path);
+ }
+
+ return VIRTUALIZATION_NONE;
+}
+
+Virtualization detect_container(void) {
+ static thread_local Virtualization cached_found = _VIRTUALIZATION_INVALID;
+ _cleanup_free_ char *m = NULL, *o = NULL, *p = NULL;
+ const char *e = NULL;
+ Virtualization v;
+ 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) {
+ if (errno != ENOENT)
+ log_debug_errno(errno, "Failed to check if /proc/vz exists, ignoring: %m");
+ } else if (access("/proc/bc", F_OK) < 0) {
+ if (errno == ENOENT) {
+ v = VIRTUALIZATION_OPENVZ;
+ goto finish;
+ }
+
+ log_debug_errno(errno, "Failed to check if /proc/bc exists, ignoring: %m");
+ }
+
+ /* "Official" way of detecting WSL https://github.com/Microsoft/WSL/issues/423#issuecomment-221627364 */
+ r = read_one_line_file("/proc/sys/kernel/osrelease", &o);
+ if (r < 0)
+ log_debug_errno(r, "Failed to read /proc/sys/kernel/osrelease, ignoring: %m");
+ else if (strstr(o, "Microsoft") || strstr(o, "WSL")) {
+ v = VIRTUALIZATION_WSL;
+ goto finish;
+ }
+
+ /* proot doesn't use PID namespacing, so we can just check if we have a matching tracer for this
+ * invocation without worrying about it being elsewhere.
+ */
+ r = get_proc_field("/proc/self/status", "TracerPid", WHITESPACE, &p);
+ if (r < 0)
+ log_debug_errno(r, "Failed to read our own trace PID, ignoring: %m");
+ else if (!streq(p, "0")) {
+ pid_t ptrace_pid;
+
+ r = parse_pid(p, &ptrace_pid);
+ if (r < 0)
+ log_debug_errno(r, "Failed to parse our own tracer PID, ignoring: %m");
+ else {
+ _cleanup_free_ char *ptrace_comm = NULL;
+ const char *pf;
+
+ pf = procfs_file_alloca(ptrace_pid, "comm");
+ r = read_one_line_file(pf, &ptrace_comm);
+ if (r < 0)
+ log_debug_errno(r, "Failed to read %s, ignoring: %m", pf);
+ else if (startswith(ptrace_comm, "proot")) {
+ v = VIRTUALIZATION_PROOT;
+ goto finish;
+ }
+ }
+ }
+
+ /* The container manager might have placed this in the /run/host/ hierarchy for us, which is best
+ * because we can be consumed just like that, without special privileges. */
+ r = read_one_line_file("/run/host/container-manager", &m);
+ if (r > 0) {
+ e = m;
+ goto translate_name;
+ }
+ if (!IN_SET(r, -ENOENT, 0))
+ return log_debug_errno(r, "Failed to read /run/host/container-manager: %m");
+
+ if (getpid_cached() == 1) {
+ /* If we are PID 1 we can just check our own environment variable, and that's authoritative.
+ * We distinguish three cases:
+ * - the variable is not defined → we jump to other checks
+ * - the variable is defined to an empty value → we are not in a container
+ * - anything else → some container, either one of the known ones or "container-other"
+ */
+ e = getenv("container");
+ if (!e)
+ goto check_files;
+ if (isempty(e)) {
+ v = 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 (!IN_SET(r, -ENOENT, 0))
+ 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");
+
+check_files:
+ /* Check for existence of some well-known files. We only do this after checking
+ * for other specific container managers, otherwise we risk mistaking another
+ * container manager for Docker: the /.dockerenv file could inadvertently end up
+ * in a file system image. */
+ v = detect_container_files();
+ if (v < 0)
+ return v;
+ if (v != VIRTUALIZATION_NONE)
+ goto finish;
+
+ r = running_in_cgroupns();
+ if (r > 0) {
+ v = VIRTUALIZATION_CONTAINER_OTHER;
+ goto finish;
+ }
+ if (r < 0)
+ log_debug_errno(r, "Failed to detect cgroup namespace: %m");
+
+ /* If none of that worked, give up, assume no container manager. */
+ v = VIRTUALIZATION_NONE;
+ goto finish;
+
+translate_name:
+ if (streq(e, "oci")) {
+ /* Some images hardcode container=oci, but OCI is not a specific container manager.
+ * Try to detect one based on well-known files. */
+ v = detect_container_files();
+ if (v == VIRTUALIZATION_NONE)
+ v = VIRTUALIZATION_CONTAINER_OTHER;
+ goto finish;
+ }
+ v = container_from_string(e);
+ if (v < 0)
+ v = VIRTUALIZATION_CONTAINER_OTHER;
+
+finish:
+ log_debug("Found container virtualization %s.", virtualization_to_string(v));
+ cached_found = v;
+ return v;
+}
+
+Virtualization detect_virtualization(void) {
+ int v;
+
+ v = detect_container();
+ if (v != VIRTUALIZATION_NONE)
+ return v;
+
+ return detect_vm();
+}
+
+static int userns_has_mapping(const char *name) {
+ _cleanup_fclose_ FILE *f = NULL;
+ uid_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;
+ }
+
+ errno = 0;
+ r = fscanf(f, UID_FMT " " UID_FMT " " UID_FMT "\n", &a, &b, &c);
+ if (r == EOF) {
+ if (ferror(f))
+ return log_debug_errno(errno_or_else(EIO), "Failed to read %s: %m", name);
+
+ log_debug("%s is empty, we're in an uninitialized user namespace", name);
+ return true;
+ }
+ if (r != 3)
+ return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG), "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_virtual_file("/proc/self/setgroups", SIZE_MAX, &line, NULL);
+ if (r < 0) {
+ log_debug_errno(r, "/proc/self/setgroups: %m");
+ return r == -ENOENT ? false : r;
+ }
+
+ strstrip(line); /* remove trailing newline */
+
+ 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 we're PID1, /proc may not be mounted (and most likely we're not in a chroot). But PID1 will
+ * mount /proc, so all other programs can assume that if /proc is *not* available, we're in some
+ * chroot. */
+
+ if (getenv_bool("SYSTEMD_IGNORE_CHROOT") > 0)
+ return 0;
+
+ r = inode_same("/proc/1/root", "/", 0);
+ if (r == -ENOENT) {
+ r = proc_mounted();
+ if (r == 0) {
+ if (getpid_cached() == 1)
+ return false; /* We will mount /proc, assuming we're not in a chroot. */
+
+ log_debug("/proc is not mounted, assuming we're in a chroot.");
+ return true;
+ }
+ if (r > 0) /* If we have fake /proc/, we can't do the check properly. */
+ return -ENOSYS;
+ }
+ if (r < 0)
+ return r;
+
+ return r == 0;
+}
+
+#if defined(__i386__) || defined(__x86_64__)
+struct cpuid_table_entry {
+ uint32_t flag_bit;
+ const char *name;
+};
+
+static const struct cpuid_table_entry leaf1_edx[] = {
+ { 0, "fpu" },
+ { 1, "vme" },
+ { 2, "de" },
+ { 3, "pse" },
+ { 4, "tsc" },
+ { 5, "msr" },
+ { 6, "pae" },
+ { 7, "mce" },
+ { 8, "cx8" },
+ { 9, "apic" },
+ { 11, "sep" },
+ { 12, "mtrr" },
+ { 13, "pge" },
+ { 14, "mca" },
+ { 15, "cmov" },
+ { 16, "pat" },
+ { 17, "pse36" },
+ { 19, "clflush" },
+ { 23, "mmx" },
+ { 24, "fxsr" },
+ { 25, "sse" },
+ { 26, "sse2" },
+ { 28, "ht" },
+};
+
+static const struct cpuid_table_entry leaf1_ecx[] = {
+ { 0, "pni" },
+ { 1, "pclmul" },
+ { 3, "monitor" },
+ { 9, "ssse3" },
+ { 12, "fma3" },
+ { 13, "cx16" },
+ { 19, "sse4_1" },
+ { 20, "sse4_2" },
+ { 22, "movbe" },
+ { 23, "popcnt" },
+ { 25, "aes" },
+ { 26, "xsave" },
+ { 27, "osxsave" },
+ { 28, "avx" },
+ { 29, "f16c" },
+ { 30, "rdrand" },
+};
+
+static const struct cpuid_table_entry leaf7_ebx[] = {
+ { 3, "bmi1" },
+ { 5, "avx2" },
+ { 8, "bmi2" },
+ { 18, "rdseed" },
+ { 19, "adx" },
+ { 29, "sha_ni" },
+};
+
+static const struct cpuid_table_entry leaf81_edx[] = {
+ { 11, "syscall" },
+ { 27, "rdtscp" },
+ { 29, "lm" },
+};
+
+static const struct cpuid_table_entry leaf81_ecx[] = {
+ { 0, "lahf_lm" },
+ { 5, "abm" },
+};
+
+static const struct cpuid_table_entry leaf87_edx[] = {
+ { 8, "constant_tsc" },
+};
+
+static bool given_flag_in_set(const char *flag, const struct cpuid_table_entry *set, size_t set_size, uint32_t val) {
+ for (size_t i = 0; i < set_size; i++) {
+ if ((UINT32_C(1) << set[i].flag_bit) & val &&
+ streq(flag, set[i].name))
+ return true;
+ }
+ return false;
+}
+
+static bool real_has_cpu_with_flag(const char *flag) {
+ uint32_t eax, ebx, ecx, edx;
+
+ if (__get_cpuid(1, &eax, &ebx, &ecx, &edx)) {
+ if (given_flag_in_set(flag, leaf1_ecx, ELEMENTSOF(leaf1_ecx), ecx))
+ return true;
+
+ if (given_flag_in_set(flag, leaf1_edx, ELEMENTSOF(leaf1_edx), edx))
+ return true;
+ }
+
+ if (__get_cpuid_count(7, 0, &eax, &ebx, &ecx, &edx)) {
+ if (given_flag_in_set(flag, leaf7_ebx, ELEMENTSOF(leaf7_ebx), ebx))
+ return true;
+ }
+
+ if (__get_cpuid(0x80000001U, &eax, &ebx, &ecx, &edx)) {
+ if (given_flag_in_set(flag, leaf81_ecx, ELEMENTSOF(leaf81_ecx), ecx))
+ return true;
+
+ if (given_flag_in_set(flag, leaf81_edx, ELEMENTSOF(leaf81_edx), edx))
+ return true;
+ }
+
+ if (__get_cpuid(0x80000007U, &eax, &ebx, &ecx, &edx))
+ if (given_flag_in_set(flag, leaf87_edx, ELEMENTSOF(leaf87_edx), edx))
+ return true;
+
+ return false;
+}
+#endif
+
+bool has_cpu_with_flag(const char *flag) {
+ /* CPUID is an x86 specific interface. Assume on all others that no CPUs have those flags. */
+#if defined(__i386__) || defined(__x86_64__)
+ return real_has_cpu_with_flag(flag);
+#else
+ return false;
+#endif
+}
+
+static const char *const virtualization_table[_VIRTUALIZATION_MAX] = {
+ [VIRTUALIZATION_NONE] = "none",
+ [VIRTUALIZATION_KVM] = "kvm",
+ [VIRTUALIZATION_AMAZON] = "amazon",
+ [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_ACRN] = "acrn",
+ [VIRTUALIZATION_POWERVM] = "powervm",
+ [VIRTUALIZATION_APPLE] = "apple",
+ [VIRTUALIZATION_SRE] = "sre",
+ [VIRTUALIZATION_GOOGLE] = "google",
+ [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_PODMAN] = "podman",
+ [VIRTUALIZATION_RKT] = "rkt",
+ [VIRTUALIZATION_WSL] = "wsl",
+ [VIRTUALIZATION_PROOT] = "proot",
+ [VIRTUALIZATION_POUCH] = "pouch",
+ [VIRTUALIZATION_CONTAINER_OTHER] = "container-other",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(virtualization, Virtualization);