Copyright 2011 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ 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
- General Public License for more details.
+ Lesser General Public License for more details.
- You should have received a copy of the GNU General Public License
+ 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 "util.h"
#include "virt.h"
+#include "fileio.h"
-/* Returns a short identifier for the various VM implementations */
-int detect_vm(const char **id) {
-
-#if defined(__i386__) || defined(__x86_64__)
+static int detect_vm_cpuid(const char **_id) {
/* Both CPUID and DMI are x86 specific interfaces... */
-
- 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"
- "Microsoft Corporation\0" "microsoft\0"
- "innotek GmbH\0" "oracle\0"
- "Xen\0" "xen\0"
- "Bochs\0" "bochs\0";
+#if defined(__i386__) || defined(__x86_64__)
static const char cpuid_vendor_table[] =
"XenVMMXenVMM\0" "xen\0"
union {
uint32_t sig32[3];
char text[13];
- } sig;
- unsigned i;
+ } sig = {};
const char *j, *k;
bool hypervisor;
/* http://lwn.net/Articles/301888/ */
- zero(sig);
#if defined (__i386__)
#define REG_a "eax"
NULSTR_FOREACH_PAIR(j, k, cpuid_vendor_table)
if (streq(sig.text, j)) {
-
- if (id)
- *id = k;
-
+ *_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++) {
- char *s;
+ _cleanup_free_ char *s = NULL;
+ const char *j, *k;
int r;
- const char *found = NULL;
- if ((r = read_one_line_file(dmi_vendors[i], &s)) < 0) {
+ r = read_one_line_file(dmi_vendors[i], &s);
+ if (r < 0) {
if (r != -ENOENT)
return r;
}
NULSTR_FOREACH_PAIR(j, k, dmi_vendor_table)
- if (startswith(s, j))
- found = k;
- free(s);
-
- if (found) {
- if (id)
- *id = found;
-
- return 1;
- }
- }
-
- if (hypervisor) {
- if (id)
- *id = "other";
-
- return 1;
+ if (startswith(s, j)) {
+ *_id = k;
+ return 1;
+ }
}
-
#endif
+
return 0;
}
-int detect_container(const char **id) {
- FILE *f;
-
- /* Unfortunately many of these operations require root access
- * in one way or another */
-
- if (geteuid() != 0)
- return -EPERM;
+/* 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 (running_in_chroot() > 0) {
+ if (_likely_(cached_found >= 0)) {
if (id)
- *id = "chroot";
+ *id = cached_id;
- return 1;
+ 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) {
-
- if (id)
- *id = "openvz";
-
- return 1;
- }
+ /* 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;
- f = fopen("/proc/1/environ", "re");
- if (f) {
- bool done = false;
+ while ((cap = strsep(&i, ",")))
+ if (streq(cap, "control_d"))
+ break;
- do {
- char line[LINE_MAX];
- unsigned i;
+ if (!i) {
+ _id = "xen";
+ r = 1;
+ }
- for (i = 0; i < sizeof(line)-1; i++) {
- int c;
+ goto finish;
- c = getc(f);
- if (_unlikely_(c == EOF)) {
- done = true;
- break;
- } else if (c == 0)
- break;
+ } else if (r == -ENOENT) {
+ _cleanup_free_ char *hvtype = NULL;
- line[i] = c;
+ r = read_one_line_file("/sys/hypervisor/type", &hvtype);
+ if (r >= 0) {
+ if (streq(hvtype, "xen")) {
+ _id = "xen";
+ r = 1;
+ goto finish;
}
- line[i] = 0;
-
- if (streq(line, "container=lxc")) {
- fclose(f);
-
- if (id)
- *id = "lxc";
- return 1;
-
- } else if (streq(line, "container=lxc-libvirt")) {
- fclose(f);
-
- if (id)
- *id = "lxc-libvirt";
- return 1;
+ } 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;
- } else if (streq(line, "container=systemd-nspawn")) {
- fclose(f);
+ r = detect_vm_dmi(&_id);
+ if (r != 0)
+ goto finish;
- if (id)
- *id = "systemd-nspawn";
- return 1;
+ if (_id) {
+ /* "other" */
+ r = 1;
+ goto finish;
+ }
- } else if (startswith(line, "container=")) {
- fclose(f);
+ /* 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 (id)
- *id = "other";
- return 1;
- }
+ r = 0;
- } while (!done);
+finish:
+ cached_found = r;
- fclose(f);
- }
+ cached_id = _id;
+ if (id)
+ *id = _id;
- return 0;
+ return r;
}
-/* Returns a short identifier for the various VM/container implementations */
-Virtualization detect_virtualization(const char **id) {
+int detect_container(const char **id) {
- static __thread Virtualization cached_virt = _VIRTUALIZATION_INVALID;
- static __thread const char *cached_id = NULL;
+ static thread_local int cached_found = -1;
+ static thread_local const char *cached_id = NULL;
- const char *_id;
+ _cleanup_free_ char *m = NULL;
+ const char *_id = NULL, *e = NULL;
int r;
- Virtualization v;
- if (_likely_(cached_virt >= 0)) {
+ if (_likely_(cached_found >= 0)) {
- if (id && cached_virt > 0)
+ if (id)
*id = cached_id;
- return cached_virt;
+ return cached_found;
}
- r = detect_container(&_id);
- if (r < 0) {
- v = r;
- goto finish;
- } else if (r > 0) {
- v = VIRTUALIZATION_CONTAINER;
+ /* /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;
}
- r = detect_vm(&_id);
- if (r < 0) {
- v = r;
- goto finish;
- } else if (r > 0) {
- v = VIRTUALIZATION_VM;
- 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) {
+ r = 0;
+ goto finish;
+ }
+ if (r < 0)
+ return r;
+
+ e = m;
}
- v = VIRTUALIZATION_NONE;
+ /* 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
+ _id = "other";
+
+ r = 1;
finish:
- if (v > 0) {
- cached_id = _id;
+ cached_found = r;
- if (id)
- *id = _id;
- }
+ 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;
- if (v >= 0)
- cached_virt = v;
+ r = detect_vm(id);
+ if (r < 0)
+ return r;
+ if (r > 0)
+ return VIRTUALIZATION_VM;
- return v;
+ return VIRTUALIZATION_NONE;
}