/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2011 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include "util.h"
#include "virt.h"
#include "fileio.h"
static int detect_vm_cpuid(const char **_id) {
/* Both CPUID and DMI are x86 specific interfaces... */
#if defined(__i386__) || defined(__x86_64__)
static const char cpuid_vendor_table[] =
"XenVMMXenVMM\0" "xen\0"
"KVMKVMKVM\0" "kvm\0"
/* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
"VMwareVMware\0" "vmware\0"
/* http://msdn.microsoft.com/en-us/library/ff542428.aspx */
"Microsoft Hv\0" "microsoft\0";
uint32_t eax, ecx;
union {
uint32_t sig32[3];
char text[13];
} sig = {};
const char *j, *k;
bool hypervisor;
/* http://lwn.net/Articles/301888/ */
#if defined (__i386__)
#define REG_a "eax"
#define REG_b "ebx"
#elif defined (__amd64__)
#define REG_a "rax"
#define REG_b "rbx"
#endif
/* First detect whether there is a hypervisor */
eax = 1;
__asm__ __volatile__ (
/* ebx/rbx is being used for PIC! */
" push %%"REG_b" \n\t"
" cpuid \n\t"
" pop %%"REG_b" \n\t"
: "=a" (eax), "=c" (ecx)
: "0" (eax)
);
hypervisor = !!(ecx & 0x80000000U);
if (hypervisor) {
/* There is a hypervisor, see what it is */
eax = 0x40000000U;
__asm__ __volatile__ (
/* ebx/rbx is being used for PIC! */
" push %%"REG_b" \n\t"
" cpuid \n\t"
" mov %%ebx, %1 \n\t"
" pop %%"REG_b" \n\t"
: "=a" (eax), "=r" (sig.sig32[0]), "=c" (sig.sig32[1]), "=d" (sig.sig32[2])
: "0" (eax)
);
NULSTR_FOREACH_PAIR(j, k, cpuid_vendor_table)
if (streq(sig.text, j)) {
*_id = k;
return 1;
}
*_id = "other";
return 0;
}
#endif
return 0;
}
static int detect_vm_dmi(const char **_id) {
/* Both CPUID and DMI are x86 specific interfaces... */
#if defined(__i386__) || defined(__x86_64__)
static const char *const dmi_vendors[] = {
"/sys/class/dmi/id/sys_vendor",
"/sys/class/dmi/id/board_vendor",
"/sys/class/dmi/id/bios_vendor"
};
static const char dmi_vendor_table[] =
"QEMU\0" "qemu\0"
/* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
"VMware\0" "vmware\0"
"VMW\0" "vmware\0"
"innotek GmbH\0" "oracle\0"
"Xen\0" "xen\0"
"Bochs\0" "bochs\0";
unsigned i;
for (i = 0; i < ELEMENTSOF(dmi_vendors); i++) {
_cleanup_free_ char *s = NULL;
const char *j, *k;
int r;
r = read_one_line_file(dmi_vendors[i], &s);
if (r < 0) {
if (r != -ENOENT)
return r;
continue;
}
NULSTR_FOREACH_PAIR(j, k, dmi_vendor_table)
if (startswith(s, j)) {
*_id = k;
return 1;
}
}
#endif
return 0;
}
/* Returns a short identifier for the various VM implementations */
int detect_vm(const char **id) {
_cleanup_free_ char *domcap = NULL, *cpuinfo_contents = NULL;
static thread_local int cached_found = -1;
static thread_local const char *cached_id = NULL;
const char *_id = NULL;
int r;
if (_likely_(cached_found >= 0)) {
if (id)
*id = cached_id;
return cached_found;
}
/* Try xen capabilities file first, if not found try high-level hypervisor sysfs file:
*
* https://bugs.freedesktop.org/show_bug.cgi?id=77271 */
r = read_one_line_file("/proc/xen/capabilities", &domcap);
if (r >= 0) {
char *cap, *i = domcap;
while ((cap = strsep(&i, ",")))
if (streq(cap, "control_d"))
break;
if (!cap) {
_id = "xen";
r = 1;
}
goto finish;
} else if (r == -ENOENT) {
_cleanup_free_ char *hvtype = NULL;
r = read_one_line_file("/sys/hypervisor/type", &hvtype);
if (r >= 0) {
if (streq(hvtype, "xen")) {
_id = "xen";
r = 1;
goto finish;
}
} else if (r != -ENOENT)
return r;
} else
return r;
/* this will set _id to "other" and return 0 for unknown hypervisors */
r = detect_vm_cpuid(&_id);
if (r != 0)
goto finish;
r = detect_vm_dmi(&_id);
if (r != 0)
goto finish;
if (_id) {
/* "other" */
r = 1;
goto finish;
}
/* Detect User-Mode Linux by reading /proc/cpuinfo */
r = read_full_file("/proc/cpuinfo", &cpuinfo_contents, NULL);
if (r < 0)
return r;
if (strstr(cpuinfo_contents, "\nvendor_id\t: User Mode Linux\n")) {
_id = "uml";
r = 1;
goto finish;
}
#if defined(__s390__)
{
_cleanup_free_ char *t = NULL;
r = get_status_field("/proc/sysinfo", "VM00 Control Program:", &t);
if (r >= 0) {
if (streq(t, "z/VM"))
_id = "zvm";
else
_id = "kvm";
r = 1;
goto finish;
}
}
#endif
r = 0;
finish:
cached_found = r;
cached_id = _id;
if (id)
*id = _id;
return r;
}
int detect_container(const char **id) {
static thread_local int cached_found = -1;
static thread_local const char *cached_id = NULL;
_cleanup_free_ char *m = NULL;
const char *_id = NULL, *e = NULL;
int r;
if (_likely_(cached_found >= 0)) {
if (id)
*id = cached_id;
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) {
_id = "openvz";
r = 1;
goto finish;
}
if (getpid() == 1) {
/* If we are PID 1 we can just check our own
* environment variable */
e = getenv("container");
if (isempty(e)) {
r = 0;
goto finish;
}
} else {
/* Otherwise, PID 1 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 == -ENOENT) {
/* 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) {
/* If that didn't work, give up,
* assume no container manager.
*
* Note: This means we still cannot
* detect containers if init=/bin/sh
* is passed but privileges dropped,
* as /proc/1/environ is only readable
* with privileges. */
r = 0;
goto finish;
}
}
if (r < 0)
return r;
e = m;
}
/* We only recognize a selected few here, since we want to
* enforce a redacted namespace */
if (streq(e, "lxc"))
_id ="lxc";
else if (streq(e, "lxc-libvirt"))
_id = "lxc-libvirt";
else if (streq(e, "systemd-nspawn"))
_id = "systemd-nspawn";
else if (streq(e, "docker"))
_id = "docker";
else
_id = "other";
r = 1;
finish:
cached_found = r;
cached_id = _id;
if (id)
*id = _id;
return r;
}
/* Returns a short identifier for the various VM/container implementations */
int detect_virtualization(const char **id) {
int r;
r = detect_container(id);
if (r < 0)
return r;
if (r > 0)
return VIRTUALIZATION_CONTAINER;
r = detect_vm(id);
if (r < 0)
return r;
if (r > 0)
return VIRTUALIZATION_VM;
return VIRTUALIZATION_NONE;
}