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[elogind.git] / src / basic / virt.c
1 /***
2   This file is part of systemd.
3
4   Copyright 2011 Lennart Poettering
5
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.
10
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.
15
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/>.
18 ***/
19
20 #include <errno.h>
21 #include <stdint.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <unistd.h>
25
26 #include "alloc-util.h"
27 #include "dirent-util.h"
28 #include "fd-util.h"
29 #include "fileio.h"
30 #include "macro.h"
31 #include "process-util.h"
32 #include "stat-util.h"
33 #include "string-table.h"
34 #include "string-util.h"
35 #include "virt.h"
36
37 #if 0 /// UNNEEDED by elogind
38 static int detect_vm_cpuid(void) {
39
40         /* CPUID is an x86 specific interface. */
41 #if defined(__i386__) || defined(__x86_64__)
42
43         static const struct {
44                 const char *cpuid;
45                 int id;
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                 /* http://msdn.microsoft.com/en-us/library/ff542428.aspx */
52                 { "Microsoft Hv", VIRTUALIZATION_MICROSOFT },
53         };
54
55         uint32_t eax, ecx;
56         bool hypervisor;
57
58         /* http://lwn.net/Articles/301888/ */
59
60 #if defined (__i386__)
61 #define REG_a "eax"
62 #define REG_b "ebx"
63 #elif defined (__amd64__)
64 #define REG_a "rax"
65 #define REG_b "rbx"
66 #endif
67
68         /* First detect whether there is a hypervisor */
69         eax = 1;
70         __asm__ __volatile__ (
71                 /* ebx/rbx is being used for PIC! */
72                 "  push %%"REG_b"         \n\t"
73                 "  cpuid                  \n\t"
74                 "  pop %%"REG_b"          \n\t"
75
76                 : "=a" (eax), "=c" (ecx)
77                 : "0" (eax)
78         );
79
80         hypervisor = !!(ecx & 0x80000000U);
81
82         if (hypervisor) {
83                 union {
84                         uint32_t sig32[3];
85                         char text[13];
86                 } sig = {};
87                 unsigned j;
88
89                 /* There is a hypervisor, see what it is */
90                 eax = 0x40000000U;
91                 __asm__ __volatile__ (
92                         /* ebx/rbx is being used for PIC! */
93                         "  push %%"REG_b"         \n\t"
94                         "  cpuid                  \n\t"
95                         "  mov %%ebx, %1          \n\t"
96                         "  pop %%"REG_b"          \n\t"
97
98                         : "=a" (eax), "=r" (sig.sig32[0]), "=c" (sig.sig32[1]), "=d" (sig.sig32[2])
99                         : "0" (eax)
100                 );
101
102                 for (j = 0; j < ELEMENTSOF(cpuid_vendor_table); j ++)
103                         if (streq(sig.text, cpuid_vendor_table[j].cpuid))
104                                 return cpuid_vendor_table[j].id;
105
106                 return VIRTUALIZATION_VM_OTHER;
107         }
108 #endif
109
110         return VIRTUALIZATION_NONE;
111 }
112
113 static int detect_vm_device_tree(void) {
114 #if defined(__arm__) || defined(__aarch64__) || defined(__powerpc__) || defined(__powerpc64__)
115         _cleanup_free_ char *hvtype = NULL;
116         int r;
117
118         r = read_one_line_file("/proc/device-tree/hypervisor/compatible", &hvtype);
119         if (r == -ENOENT) {
120                 _cleanup_closedir_ DIR *dir = NULL;
121                 struct dirent *dent;
122
123                 dir = opendir("/proc/device-tree");
124                 if (!dir) {
125                         if (errno == ENOENT)
126                                 return VIRTUALIZATION_NONE;
127                         return -errno;
128                 }
129
130                 FOREACH_DIRENT(dent, dir, return -errno)
131                         if (strstr(dent->d_name, "fw-cfg"))
132                                 return VIRTUALIZATION_QEMU;
133
134                 return VIRTUALIZATION_NONE;
135         } else if (r < 0)
136                 return r;
137
138         if (streq(hvtype, "linux,kvm"))
139                 return VIRTUALIZATION_KVM;
140         else if (strstr(hvtype, "xen"))
141                 return VIRTUALIZATION_XEN;
142         else
143                 return VIRTUALIZATION_VM_OTHER;
144 #else
145         return VIRTUALIZATION_NONE;
146 #endif
147 }
148
149 static int detect_vm_dmi(void) {
150 #if defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__aarch64__)
151
152         static const char *const dmi_vendors[] = {
153                 "/sys/class/dmi/id/product_name", /* Test this before sys_vendor to detect KVM over QEMU */
154                 "/sys/class/dmi/id/sys_vendor",
155                 "/sys/class/dmi/id/board_vendor",
156                 "/sys/class/dmi/id/bios_vendor"
157         };
158
159         static const struct {
160                 const char *vendor;
161                 int id;
162         } dmi_vendor_table[] = {
163                 { "KVM",           VIRTUALIZATION_KVM       },
164                 { "QEMU",          VIRTUALIZATION_QEMU      },
165                 /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
166                 { "VMware",        VIRTUALIZATION_VMWARE    },
167                 { "VMW",           VIRTUALIZATION_VMWARE    },
168                 { "innotek GmbH",  VIRTUALIZATION_ORACLE    },
169                 { "Xen",           VIRTUALIZATION_XEN       },
170                 { "Bochs",         VIRTUALIZATION_BOCHS     },
171                 { "Parallels",     VIRTUALIZATION_PARALLELS },
172         };
173         unsigned i;
174         int r;
175
176         for (i = 0; i < ELEMENTSOF(dmi_vendors); i++) {
177                 _cleanup_free_ char *s = NULL;
178                 unsigned j;
179
180                 r = read_one_line_file(dmi_vendors[i], &s);
181                 if (r < 0) {
182                         if (r == -ENOENT)
183                         continue;
184
185                         return r;
186                         }
187
188                 for (j = 0; j < ELEMENTSOF(dmi_vendor_table); j++)
189                         if (startswith(s, dmi_vendor_table[j].vendor))
190                                 return dmi_vendor_table[j].id;
191         }
192 #endif
193
194         return VIRTUALIZATION_NONE;
195 }
196
197 static int detect_vm_xen(void) {
198         _cleanup_free_ char *domcap = NULL;
199         char *cap, *i;
200         int r;
201
202         r = read_one_line_file("/proc/xen/capabilities", &domcap);
203         if (r == -ENOENT)
204                 return VIRTUALIZATION_NONE;
205
206         i = domcap;
207                 while ((cap = strsep(&i, ",")))
208                         if (streq(cap, "control_d"))
209                                 break;
210
211         return cap ? VIRTUALIZATION_NONE : VIRTUALIZATION_XEN;
212                 }
213
214 static int detect_vm_hypervisor(void) {
215                 _cleanup_free_ char *hvtype = NULL;
216         int r;
217
218                 r = read_one_line_file("/sys/hypervisor/type", &hvtype);
219         if (r == -ENOENT)
220                 return VIRTUALIZATION_NONE;
221         if (r < 0)
222                 return r;
223
224         if (streq(hvtype, "xen"))
225                 return VIRTUALIZATION_XEN;
226         else
227                 return VIRTUALIZATION_VM_OTHER;
228 }
229
230 static int detect_vm_uml(void) {
231         _cleanup_free_ char *cpuinfo_contents = NULL;
232         int r;
233
234         /* Detect User-Mode Linux by reading /proc/cpuinfo */
235         r = read_full_file("/proc/cpuinfo", &cpuinfo_contents, NULL);
236         if (r < 0)
237                 return r;
238         if (strstr(cpuinfo_contents, "\nvendor_id\t: User Mode Linux\n"))
239                 return VIRTUALIZATION_UML;
240
241         return VIRTUALIZATION_NONE;
242 }
243
244 static int detect_vm_zvm(void) {
245
246 #if defined(__s390__)
247         _cleanup_free_ char *t = NULL;
248         int r;
249
250         r = get_proc_field("/proc/sysinfo", "VM00 Control Program", WHITESPACE, &t);
251         if (r == -ENOENT)
252                 return VIRTUALIZATION_NONE;
253         if (r < 0)
254                 return r;
255
256         if (streq(t, "z/VM"))
257                 return VIRTUALIZATION_ZVM;
258         else
259                 return VIRTUALIZATION_KVM;
260 #else
261         return VIRTUALIZATION_NONE;
262 #endif
263         }
264
265 /* Returns a short identifier for the various VM implementations */
266 int detect_vm(void) {
267         static thread_local int cached_found = _VIRTUALIZATION_INVALID;
268         int r;
269
270         if (cached_found >= 0)
271                 return cached_found;
272
273         /* We have to use the correct order here:
274          * Some virtualization technologies do use KVM hypervisor but are
275          * expected to be detected as something else. So detect DMI first.
276          *
277          * An example is Virtualbox since version 5.0, which uses KVM backend.
278          * Detection via DMI works corretly, the CPU ID would find KVM
279          * only. */
280         r = detect_vm_dmi();
281         if (r < 0)
282                 return r;
283         if (r != VIRTUALIZATION_NONE)
284                 goto finish;
285
286         r = detect_vm_cpuid();
287         if (r < 0)
288                 return r;
289         if (r != VIRTUALIZATION_NONE)
290                 goto finish;
291
292         /* x86 xen will most likely be detected by cpuid. If not (most likely
293          * because we're not an x86 guest), then we should try the xen capabilities
294          * file next. If that's not found, then we check for the high-level
295          * hypervisor sysfs file:
296          *
297          * https://bugs.freedesktop.org/show_bug.cgi?id=77271 */
298
299         r = detect_vm_xen();
300         if (r < 0)
301                 return r;
302         if (r != VIRTUALIZATION_NONE)
303                 goto finish;
304
305         r = detect_vm_hypervisor();
306         if (r < 0)
307                 return r;
308         if (r != VIRTUALIZATION_NONE)
309                 goto finish;
310
311         r = detect_vm_device_tree();
312         if (r < 0)
313                 return r;
314         if (r != VIRTUALIZATION_NONE)
315                 goto finish;
316
317         r = detect_vm_uml();
318         if (r < 0)
319                 return r;
320         if (r != VIRTUALIZATION_NONE)
321                         goto finish;
322
323         r = detect_vm_zvm();
324         if (r < 0)
325                 return r;
326
327 finish:
328         cached_found = r;
329         return r;
330 }
331 #endif // 0
332
333 int detect_container(void) {
334
335         static const struct {
336                 const char *value;
337                 int id;
338         } value_table[] = {
339                 { "lxc",            VIRTUALIZATION_LXC            },
340                 { "lxc-libvirt",    VIRTUALIZATION_LXC_LIBVIRT    },
341                 { "systemd-nspawn", VIRTUALIZATION_SYSTEMD_NSPAWN },
342                 { "docker",         VIRTUALIZATION_DOCKER         },
343                 { "rkt",            VIRTUALIZATION_RKT            },
344         };
345
346         static thread_local int cached_found = _VIRTUALIZATION_INVALID;
347         _cleanup_free_ char *m = NULL;
348         const char *e = NULL;
349         unsigned j;
350         int r;
351
352         if (cached_found >= 0)
353                 return cached_found;
354
355         /* /proc/vz exists in container and outside of the container,
356          * /proc/bc only outside of the container. */
357         if (access("/proc/vz", F_OK) >= 0 &&
358             access("/proc/bc", F_OK) < 0) {
359                 r = VIRTUALIZATION_OPENVZ;
360                 goto finish;
361         }
362
363         if (getpid() == 1) {
364                 /* If we are PID 1 we can just check our own
365                  * environment variable */
366
367                 e = getenv("container");
368                 if (isempty(e)) {
369                         r = VIRTUALIZATION_NONE;
370                         goto finish;
371                 }
372         } else {
373
374                 /* Otherwise, PID 1 dropped this information into a
375                  * file in /run. This is better than accessing
376                  * /proc/1/environ, since we don't need CAP_SYS_PTRACE
377                  * for that. */
378
379                 r = read_one_line_file("/run/systemd/container", &m);
380                 if (r == -ENOENT) {
381
382                         /* Fallback for cases where PID 1 was not
383                          * systemd (for example, cases where
384                          * init=/bin/sh is used. */
385
386                         r = getenv_for_pid(1, "container", &m);
387                         if (r <= 0) {
388
389                                 /* If that didn't work, give up,
390                                  * assume no container manager.
391                                  *
392                                  * Note: This means we still cannot
393                                  * detect containers if init=/bin/sh
394                                  * is passed but privileges dropped,
395                                  * as /proc/1/environ is only readable
396                                  * with privileges. */
397
398                                 r = VIRTUALIZATION_NONE;
399                                 goto finish;
400                         }
401                 }
402                 if (r < 0)
403                         return r;
404
405                 e = m;
406         }
407
408         for (j = 0; j < ELEMENTSOF(value_table); j++)
409                 if (streq(e, value_table[j].value)) {
410                         r = value_table[j].id;
411                         goto finish;
412                 }
413
414         r = VIRTUALIZATION_CONTAINER_OTHER;
415
416 finish:
417         cached_found = r;
418         return r;
419 }
420
421 #if 0 /// UNNEEDED by elogind
422 int detect_virtualization(void) {
423         int r;
424
425         r = detect_container();
426         if (r != 0)
427                 return r;
428
429         return detect_vm();
430 }
431 #endif // 0
432
433 int running_in_chroot(void) {
434         int ret;
435
436         ret = files_same("/proc/1/root", "/");
437         if (ret < 0)
438                 return ret;
439
440         return ret == 0;
441 }
442
443 #if 0 /// UNNEEDED by elogind
444 static const char *const virtualization_table[_VIRTUALIZATION_MAX] = {
445         [VIRTUALIZATION_NONE] = "none",
446         [VIRTUALIZATION_KVM] = "kvm",
447         [VIRTUALIZATION_QEMU] = "qemu",
448         [VIRTUALIZATION_BOCHS] = "bochs",
449         [VIRTUALIZATION_XEN] = "xen",
450         [VIRTUALIZATION_UML] = "uml",
451         [VIRTUALIZATION_VMWARE] = "vmware",
452         [VIRTUALIZATION_ORACLE] = "oracle",
453         [VIRTUALIZATION_MICROSOFT] = "microsoft",
454         [VIRTUALIZATION_ZVM] = "zvm",
455         [VIRTUALIZATION_PARALLELS] = "parallels",
456         [VIRTUALIZATION_VM_OTHER] = "vm-other",
457
458         [VIRTUALIZATION_SYSTEMD_NSPAWN] = "systemd-nspawn",
459         [VIRTUALIZATION_LXC_LIBVIRT] = "lxc-libvirt",
460         [VIRTUALIZATION_LXC] = "lxc",
461         [VIRTUALIZATION_OPENVZ] = "openvz",
462         [VIRTUALIZATION_DOCKER] = "docker",
463         [VIRTUALIZATION_RKT] = "rkt",
464         [VIRTUALIZATION_CONTAINER_OTHER] = "container-other",
465 };
466
467 DEFINE_STRING_TABLE_LOOKUP(virtualization, int);
468 #endif // 0