/*-*- 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; }