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+/*-*- 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 "process-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_devicetree(const char **_id) {
+#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 >= 0) {
+ if (streq(hvtype, "linux,kvm")) {
+ *_id = "kvm";
+ return 1;
+ } else if (strstr(hvtype, "xen")) {
+ *_id = "xen";
+ return 1;
+ }
+ } else if (r == -ENOENT) {
+ _cleanup_closedir_ DIR *dir = NULL;
+ struct dirent *dent;
+
+ dir = opendir("/proc/device-tree");
+ if (!dir) {
+ if (errno == ENOENT)
+ return 0;
+ return -errno;
+ }
+
+ FOREACH_DIRENT(dent, dir, return -errno) {
+ if (strstr(dent->d_name, "fw-cfg")) {
+ *_id = "qemu";
+ return 1;
+ }
+ }
+ }
+#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;
+
+ r = detect_vm_devicetree(&_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;
+}
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