2 This file is part of systemd.
4 Copyright 2011 Lennart Poettering
6 systemd is free software; you can redistribute it and/or modify it
7 under the terms of the GNU Lesser General Public License as published by
8 the Free Software Foundation; either version 2.1 of the License, or
9 (at your option) any later version.
11 systemd is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public License
17 along with systemd; If not, see <http://www.gnu.org/licenses/>.
26 #include "alloc-util.h"
27 #include "dirent-util.h"
31 #include "process-util.h"
32 #include "stat-util.h"
33 #include "string-table.h"
34 #include "string-util.h"
37 #if 0 /// UNNEEDED by elogind
38 static int detect_vm_cpuid(void) {
40 /* CPUID is an x86 specific interface. */
41 #if defined(__i386__) || defined(__x86_64__)
46 } cpuid_vendor_table[] = {
47 { "XenVMMXenVMM", VIRTUALIZATION_XEN },
48 { "KVMKVMKVM", VIRTUALIZATION_KVM },
49 /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
50 { "VMwareVMware", VIRTUALIZATION_VMWARE },
51 /* https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs */
52 { "Microsoft Hv", VIRTUALIZATION_MICROSOFT },
53 /* https://wiki.freebsd.org/bhyve */
54 { "bhyve bhyve ", VIRTUALIZATION_BHYVE },
60 /* http://lwn.net/Articles/301888/ */
62 #if defined (__i386__)
65 #elif defined (__amd64__)
70 /* First detect whether there is a hypervisor */
72 __asm__ __volatile__ (
73 /* ebx/rbx is being used for PIC! */
74 " push %%"REG_b" \n\t"
78 : "=a" (eax), "=c" (ecx)
82 hypervisor = !!(ecx & 0x80000000U);
91 /* There is a hypervisor, see what it is */
93 __asm__ __volatile__ (
94 /* ebx/rbx is being used for PIC! */
95 " push %%"REG_b" \n\t"
100 : "=a" (eax), "=r" (sig.sig32[0]), "=c" (sig.sig32[1]), "=d" (sig.sig32[2])
104 log_debug("Virtualization found, CPUID=%s", sig.text);
106 for (j = 0; j < ELEMENTSOF(cpuid_vendor_table); j ++)
107 if (streq(sig.text, cpuid_vendor_table[j].cpuid))
108 return cpuid_vendor_table[j].id;
110 return VIRTUALIZATION_VM_OTHER;
113 log_debug("No virtualization found in CPUID");
115 return VIRTUALIZATION_NONE;
118 static int detect_vm_device_tree(void) {
119 #if defined(__arm__) || defined(__aarch64__) || defined(__powerpc__) || defined(__powerpc64__)
120 _cleanup_free_ char *hvtype = NULL;
123 r = read_one_line_file("/proc/device-tree/hypervisor/compatible", &hvtype);
125 _cleanup_closedir_ DIR *dir = NULL;
128 dir = opendir("/proc/device-tree");
130 if (errno == ENOENT) {
131 log_debug_errno(errno, "/proc/device-tree: %m");
132 return VIRTUALIZATION_NONE;
137 FOREACH_DIRENT(dent, dir, return -errno)
138 if (strstr(dent->d_name, "fw-cfg")) {
139 log_debug("Virtualization QEMU: \"fw-cfg\" present in /proc/device-tree/%s", dent->d_name);
140 return VIRTUALIZATION_QEMU;
143 log_debug("No virtualization found in /proc/device-tree/*");
144 return VIRTUALIZATION_NONE;
148 log_debug("Virtualization %s found in /proc/device-tree/hypervisor/compatible", hvtype);
149 if (streq(hvtype, "linux,kvm"))
150 return VIRTUALIZATION_KVM;
151 else if (strstr(hvtype, "xen"))
152 return VIRTUALIZATION_XEN;
154 return VIRTUALIZATION_VM_OTHER;
156 log_debug("This platform does not support /proc/device-tree");
157 return VIRTUALIZATION_NONE;
161 static int detect_vm_dmi(void) {
162 #if defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__aarch64__)
164 static const char *const dmi_vendors[] = {
165 "/sys/class/dmi/id/product_name", /* Test this before sys_vendor to detect KVM over QEMU */
166 "/sys/class/dmi/id/sys_vendor",
167 "/sys/class/dmi/id/board_vendor",
168 "/sys/class/dmi/id/bios_vendor"
171 static const struct {
174 } dmi_vendor_table[] = {
175 { "KVM", VIRTUALIZATION_KVM },
176 { "QEMU", VIRTUALIZATION_QEMU },
177 /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
178 { "VMware", VIRTUALIZATION_VMWARE },
179 { "VMW", VIRTUALIZATION_VMWARE },
180 { "innotek GmbH", VIRTUALIZATION_ORACLE },
181 { "Xen", VIRTUALIZATION_XEN },
182 { "Bochs", VIRTUALIZATION_BOCHS },
183 { "Parallels", VIRTUALIZATION_PARALLELS },
184 /* https://wiki.freebsd.org/bhyve */
185 { "BHYVE", VIRTUALIZATION_BHYVE },
190 for (i = 0; i < ELEMENTSOF(dmi_vendors); i++) {
191 _cleanup_free_ char *s = NULL;
194 r = read_one_line_file(dmi_vendors[i], &s);
204 for (j = 0; j < ELEMENTSOF(dmi_vendor_table); j++)
205 if (startswith(s, dmi_vendor_table[j].vendor)) {
206 log_debug("Virtualization %s found in DMI (%s)", s, dmi_vendors[i]);
207 return dmi_vendor_table[j].id;
212 log_debug("No virtualization found in DMI");
214 return VIRTUALIZATION_NONE;
217 static int detect_vm_xen(void) {
218 /* Check for Dom0 will be executed later in detect_vm_xen_dom0
219 Thats why we dont check the content of /proc/xen/capabilities here. */
220 if (access("/proc/xen/capabilities", F_OK) < 0) {
221 log_debug("Virtualization XEN not found, /proc/xen/capabilities does not exist");
222 return VIRTUALIZATION_NONE;
225 log_debug("Virtualization XEN found (/proc/xen/capabilities exists)");
226 return VIRTUALIZATION_XEN;
230 static bool detect_vm_xen_dom0(void) {
231 _cleanup_free_ char *domcap = NULL;
235 r = read_one_line_file("/proc/xen/capabilities", &domcap);
237 log_debug("Virtualization XEN not found, /proc/xen/capabilities does not exist");
244 while ((cap = strsep(&i, ",")))
245 if (streq(cap, "control_d"))
248 log_debug("Virtualization XEN DomU found (/proc/xen/capabilites)");
252 log_debug("Virtualization XEN Dom0 ignored (/proc/xen/capabilities)");
256 static int detect_vm_hypervisor(void) {
257 _cleanup_free_ char *hvtype = NULL;
260 r = read_one_line_file("/sys/hypervisor/type", &hvtype);
262 return VIRTUALIZATION_NONE;
266 log_debug("Virtualization %s found in /sys/hypervisor/type", hvtype);
268 if (streq(hvtype, "xen"))
269 return VIRTUALIZATION_XEN;
271 return VIRTUALIZATION_VM_OTHER;
274 static int detect_vm_uml(void) {
275 _cleanup_free_ char *cpuinfo_contents = NULL;
278 /* Detect User-Mode Linux by reading /proc/cpuinfo */
279 r = read_full_file("/proc/cpuinfo", &cpuinfo_contents, NULL);
283 if (strstr(cpuinfo_contents, "\nvendor_id\t: User Mode Linux\n")) {
284 log_debug("UML virtualization found in /proc/cpuinfo");
285 return VIRTUALIZATION_UML;
288 log_debug("No virtualization found in /proc/cpuinfo.");
289 return VIRTUALIZATION_NONE;
292 static int detect_vm_zvm(void) {
294 #if defined(__s390__)
295 _cleanup_free_ char *t = NULL;
298 r = get_proc_field("/proc/sysinfo", "VM00 Control Program", WHITESPACE, &t);
300 return VIRTUALIZATION_NONE;
304 log_debug("Virtualization %s found in /proc/sysinfo", t);
305 if (streq(t, "z/VM"))
306 return VIRTUALIZATION_ZVM;
308 return VIRTUALIZATION_KVM;
310 log_debug("This platform does not support /proc/sysinfo");
311 return VIRTUALIZATION_NONE;
315 /* Returns a short identifier for the various VM implementations */
316 int detect_vm(void) {
317 static thread_local int cached_found = _VIRTUALIZATION_INVALID;
320 if (cached_found >= 0)
323 /* We have to use the correct order here:
324 * Some virtualization technologies do use KVM hypervisor but are
325 * expected to be detected as something else. So detect DMI first.
327 * An example is Virtualbox since version 5.0, which uses KVM backend.
328 * Detection via DMI works corretly, the CPU ID would find KVM
333 if (r != VIRTUALIZATION_NONE)
336 r = detect_vm_cpuid();
339 if (r != VIRTUALIZATION_NONE)
342 /* x86 xen will most likely be detected by cpuid. If not (most likely
343 * because we're not an x86 guest), then we should try the xen capabilities
344 * file next. If that's not found, then we check for the high-level
345 * hypervisor sysfs file:
347 * https://bugs.freedesktop.org/show_bug.cgi?id=77271 */
352 if (r != VIRTUALIZATION_NONE)
355 r = detect_vm_hypervisor();
358 if (r != VIRTUALIZATION_NONE)
361 r = detect_vm_device_tree();
364 if (r != VIRTUALIZATION_NONE)
370 if (r != VIRTUALIZATION_NONE)
378 /* x86 xen Dom0 is detected as XEN in hypervisor and maybe others.
379 * In order to detect the Dom0 as not virtualization we need to
381 if (r == VIRTUALIZATION_XEN && detect_vm_xen_dom0())
382 r = VIRTUALIZATION_NONE;
385 log_debug("Found VM virtualization %s", virtualization_to_string(r));
390 int detect_container(void) {
392 static const struct {
396 { "lxc", VIRTUALIZATION_LXC },
397 { "lxc-libvirt", VIRTUALIZATION_LXC_LIBVIRT },
398 { "systemd-nspawn", VIRTUALIZATION_SYSTEMD_NSPAWN },
399 { "docker", VIRTUALIZATION_DOCKER },
400 { "rkt", VIRTUALIZATION_RKT },
403 static thread_local int cached_found = _VIRTUALIZATION_INVALID;
404 _cleanup_free_ char *m = NULL;
405 const char *e = NULL;
409 if (cached_found >= 0)
412 /* /proc/vz exists in container and outside of the container, /proc/bc only outside of the container. */
413 if (access("/proc/vz", F_OK) >= 0 &&
414 access("/proc/bc", F_OK) < 0) {
415 r = VIRTUALIZATION_OPENVZ;
420 /* If we are PID 1 we can just check our own environment variable, and that's authoritative. */
422 e = getenv("container");
424 r = VIRTUALIZATION_NONE;
431 /* Otherwise, PID 1 might have dropped this information into a file in /run. This is better than accessing
432 * /proc/1/environ, since we don't need CAP_SYS_PTRACE for that. */
433 r = read_one_line_file("/run/systemd/container", &m);
439 return log_debug_errno(r, "Failed to read /run/systemd/container: %m");
441 /* Fallback for cases where PID 1 was not systemd (for example, cases where init=/bin/sh is used. */
442 r = getenv_for_pid(1, "container", &m);
447 if (r < 0) /* This only works if we have CAP_SYS_PTRACE, hence let's better ignore failures here */
448 log_debug_errno(r, "Failed to read $container of PID 1, ignoring: %m");
450 /* Interestingly /proc/1/sched actually shows the host's PID for what we see as PID 1. Hence, if the PID shown
451 * there is not 1, we know we are in a PID namespace. and hence a container. */
452 r = read_one_line_file("/proc/1/sched", &m);
460 if (!startswith(t, "(1,")) {
461 r = VIRTUALIZATION_CONTAINER_OTHER;
464 } else if (r != -ENOENT)
467 /* If that didn't work, give up, assume no container manager. */
468 r = VIRTUALIZATION_NONE;
472 for (j = 0; j < ELEMENTSOF(value_table); j++)
473 if (streq(e, value_table[j].value)) {
474 r = value_table[j].id;
478 r = VIRTUALIZATION_CONTAINER_OTHER;
481 log_debug("Found container virtualization %s.", virtualization_to_string(r));
486 #if 0 /// UNNEEDED by elogind
487 int detect_virtualization(void) {
490 r = detect_container();
497 static int userns_has_mapping(const char *name) {
498 _cleanup_fclose_ FILE *f = NULL;
499 _cleanup_free_ char *buf = NULL;
500 size_t n_allocated = 0;
505 f = fopen(name, "re");
507 log_debug_errno(errno, "Failed to open %s: %m", name);
508 return errno == ENOENT ? false : -errno;
511 n = getline(&buf, &n_allocated, f);
514 log_debug("%s is empty, we're in an uninitialized user namespace", name);
518 return log_debug_errno(errno, "Failed to read %s: %m", name);
521 r = sscanf(buf, "%"PRIu32" %"PRIu32" %"PRIu32, &a, &b, &c);
523 return log_debug_errno(errno, "Failed to parse %s: %m", name);
525 if (a == 0 && b == 0 && c == UINT32_MAX) {
526 /* The kernel calls mappings_overlap() and does not allow overlaps */
527 log_debug("%s has a full 1:1 mapping", name);
531 /* Anything else implies that we are in a user namespace */
532 log_debug("Mapping found in %s, we're in a user namespace", name);
536 int running_in_userns(void) {
537 _cleanup_free_ char *line = NULL;
540 r = userns_has_mapping("/proc/self/uid_map");
544 r = userns_has_mapping("/proc/self/gid_map");
548 /* "setgroups" file was added in kernel v3.18-rc6-15-g9cc46516dd. It is also
549 * possible to compile a kernel without CONFIG_USER_NS, in which case "setgroups"
550 * also does not exist. We cannot distinguish those two cases, so assume that
551 * we're running on a stripped-down recent kernel, rather than on an old one,
552 * and if the file is not found, return false.
554 r = read_one_line_file("/proc/self/setgroups", &line);
556 log_debug_errno(r, "/proc/self/setgroups: %m");
557 return r == -ENOENT ? false : r;
561 r = streq(line, "deny");
562 /* See user_namespaces(7) for a description of this "setgroups" contents. */
563 log_debug("/proc/self/setgroups contains \"%s\", %s user namespace", line, r ? "in" : "not in");
568 int running_in_chroot(void) {
569 _cleanup_free_ char *self_mnt = NULL, *pid1_mnt = NULL;
572 /* Try to detect whether we are running in a chroot() environment. Specifically, check whether we have a
573 * different root directory than PID 1, even though we live in the same mount namespace as it. */
575 #if 0 /// elogind does not allow to ignore chroots, we are never init!
576 if (getenv_bool("SYSTEMD_IGNORE_CHROOT") > 0)
580 r = files_same("/proc/1/root", "/");
586 r = readlink_malloc("/proc/self/ns/mnt", &self_mnt);
590 r = readlink_malloc("/proc/1/ns/mnt", &pid1_mnt);
594 return streq(self_mnt, pid1_mnt); /* Only if we live in the same namespace! */
597 static const char *const virtualization_table[_VIRTUALIZATION_MAX] = {
598 [VIRTUALIZATION_NONE] = "none",
599 [VIRTUALIZATION_KVM] = "kvm",
600 [VIRTUALIZATION_QEMU] = "qemu",
601 [VIRTUALIZATION_BOCHS] = "bochs",
602 [VIRTUALIZATION_XEN] = "xen",
603 [VIRTUALIZATION_UML] = "uml",
604 [VIRTUALIZATION_VMWARE] = "vmware",
605 [VIRTUALIZATION_ORACLE] = "oracle",
606 [VIRTUALIZATION_MICROSOFT] = "microsoft",
607 [VIRTUALIZATION_ZVM] = "zvm",
608 [VIRTUALIZATION_PARALLELS] = "parallels",
609 [VIRTUALIZATION_BHYVE] = "bhyve",
610 [VIRTUALIZATION_VM_OTHER] = "vm-other",
612 [VIRTUALIZATION_SYSTEMD_NSPAWN] = "systemd-nspawn",
613 [VIRTUALIZATION_LXC_LIBVIRT] = "lxc-libvirt",
614 [VIRTUALIZATION_LXC] = "lxc",
615 [VIRTUALIZATION_OPENVZ] = "openvz",
616 [VIRTUALIZATION_DOCKER] = "docker",
617 [VIRTUALIZATION_RKT] = "rkt",
618 [VIRTUALIZATION_CONTAINER_OTHER] = "container-other",
621 DEFINE_STRING_TABLE_LOOKUP(virtualization, int);