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-rw-r--r--src/basic/virt.c642
1 files changed, 642 insertions, 0 deletions
diff --git a/src/basic/virt.c b/src/basic/virt.c
new file mode 100644
index 0000000..f63f15f
--- /dev/null
+++ b/src/basic/virt.c
@@ -0,0 +1,642 @@
+/* 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_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 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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-17 10:23:35 +0000