summaryrefslogtreecommitdiff
path: root/src/basic/virt.c
blob: 9ea18e63f466a1251eb647f4cdc1bc32e4c85274 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
/***
  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 <errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "alloc-util.h"
#include "dirent-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "macro.h"
#include "process-util.h"
#include "stat-util.h"
#include "string-table.h"
#include "string-util.h"
#include "virt.h"

#if 0 /// UNNEEDED by elogind
static int detect_vm_cpuid(void) {

        /* CPUID is an x86 specific interface. */
#if defined(__i386__) || defined(__x86_64__)

        static const struct {
                const char *cpuid;
                int id;
        } cpuid_vendor_table[] = {
                { "XenVMMXenVMM", VIRTUALIZATION_XEN       },
                { "KVMKVMKVM",    VIRTUALIZATION_KVM       },
                /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
                { "VMwareVMware", VIRTUALIZATION_VMWARE    },
                /* https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/reference/tlfs */
                { "Microsoft Hv", VIRTUALIZATION_MICROSOFT },
                /* https://wiki.freebsd.org/bhyve */
                { "bhyve bhyve ", VIRTUALIZATION_BHYVE     },
        };

        uint32_t eax, ecx;
        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) {
                union {
                        uint32_t sig32[3];
                        char text[13];
                } sig = {};
                unsigned j;

                /* 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)
                );

                log_debug("Virtualization found, CPUID=%s", sig.text);

                for (j = 0; j < ELEMENTSOF(cpuid_vendor_table); j ++)
                        if (streq(sig.text, cpuid_vendor_table[j].cpuid))
                                return cpuid_vendor_table[j].id;

                return VIRTUALIZATION_VM_OTHER;
        }
#endif
        log_debug("No virtualization found in CPUID");

        return VIRTUALIZATION_NONE;
}

static int detect_vm_device_tree(void) {
#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 == -ENOENT) {
                _cleanup_closedir_ DIR *dir = NULL;
                struct dirent *dent;

                dir = opendir("/proc/device-tree");
                if (!dir) {
                        if (errno == ENOENT) {
                                log_debug_errno(errno, "/proc/device-tree: %m");
                                return VIRTUALIZATION_NONE;
                        }
                        return -errno;
                }

                FOREACH_DIRENT(dent, dir, return -errno)
                        if (strstr(dent->d_name, "fw-cfg")) {
                                log_debug("Virtualization QEMU: \"fw-cfg\" present in /proc/device-tree/%s", dent->d_name);
                                return VIRTUALIZATION_QEMU;
                        }

                log_debug("No virtualization found in /proc/device-tree/*");
                return VIRTUALIZATION_NONE;
        } else if (r < 0)
                return r;

        log_debug("Virtualization %s found in /proc/device-tree/hypervisor/compatible", hvtype);
        if (streq(hvtype, "linux,kvm"))
                return VIRTUALIZATION_KVM;
        else if (strstr(hvtype, "xen"))
                return VIRTUALIZATION_XEN;
        else
                return VIRTUALIZATION_VM_OTHER;
#else
        log_debug("This platform does not support /proc/device-tree");
        return VIRTUALIZATION_NONE;
#endif
}

static int detect_vm_dmi(void) {
#if defined(__i386__) || defined(__x86_64__) || defined(__arm__) || defined(__aarch64__)

        static const char *const dmi_vendors[] = {
                "/sys/class/dmi/id/product_name", /* Test this before sys_vendor to detect KVM over QEMU */
                "/sys/class/dmi/id/sys_vendor",
                "/sys/class/dmi/id/board_vendor",
                "/sys/class/dmi/id/bios_vendor"
        };

        static const struct {
                const char *vendor;
                int id;
        } dmi_vendor_table[] = {
                { "KVM",           VIRTUALIZATION_KVM       },
                { "QEMU",          VIRTUALIZATION_QEMU      },
                /* http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1009458 */
                { "VMware",        VIRTUALIZATION_VMWARE    },
                { "VMW",           VIRTUALIZATION_VMWARE    },
                { "innotek GmbH",  VIRTUALIZATION_ORACLE    },
                { "Xen",           VIRTUALIZATION_XEN       },
                { "Bochs",         VIRTUALIZATION_BOCHS     },
                { "Parallels",     VIRTUALIZATION_PARALLELS },
                /* https://wiki.freebsd.org/bhyve */
                { "BHYVE",         VIRTUALIZATION_BHYVE     },
        };
        unsigned i;
        int r;

        for (i = 0; i < ELEMENTSOF(dmi_vendors); i++) {
                _cleanup_free_ char *s = NULL;
                unsigned j;

                r = read_one_line_file(dmi_vendors[i], &s);
                if (r < 0) {
                        if (r == -ENOENT)
                                continue;

                        return r;
                }



                for (j = 0; j < ELEMENTSOF(dmi_vendor_table); j++)
                        if (startswith(s, dmi_vendor_table[j].vendor)) {
                                log_debug("Virtualization %s found in DMI (%s)", s, dmi_vendors[i]);
                                return dmi_vendor_table[j].id;
                        }
        }
#endif

        log_debug("No virtualization found in DMI");

        return VIRTUALIZATION_NONE;
}

static int detect_vm_xen(void) {
        /* Check for Dom0 will be executed later in detect_vm_xen_dom0
           Thats why we dont check the content of /proc/xen/capabilities here. */
        if (access("/proc/xen/capabilities", F_OK) < 0) {
                log_debug("Virtualization XEN not found, /proc/xen/capabilities does not exist");
                return VIRTUALIZATION_NONE;
        }

        log_debug("Virtualization XEN found (/proc/xen/capabilities exists)");
        return  VIRTUALIZATION_XEN;

}

static bool detect_vm_xen_dom0(void) {
        _cleanup_free_ char *domcap = NULL;
        char *cap, *i;
        int r;

        r = read_one_line_file("/proc/xen/capabilities", &domcap);
        if (r == -ENOENT) {
                log_debug("Virtualization XEN not found, /proc/xen/capabilities does not exist");
                return false;
        }
        if (r < 0)
                return r;

        i = domcap;
        while ((cap = strsep(&i, ",")))
                if (streq(cap, "control_d"))
                        break;
        if (!cap) {
                log_debug("Virtualization XEN DomU found (/proc/xen/capabilites)");
                return false;
        }

        log_debug("Virtualization XEN Dom0 ignored (/proc/xen/capabilities)");
        return true;
}

static int detect_vm_hypervisor(void) {
        _cleanup_free_ char *hvtype = NULL;
        int r;

        r = read_one_line_file("/sys/hypervisor/type", &hvtype);
        if (r == -ENOENT)
                return VIRTUALIZATION_NONE;
        if (r < 0)
                return r;

        log_debug("Virtualization %s found in /sys/hypervisor/type", hvtype);

        if (streq(hvtype, "xen"))
                return VIRTUALIZATION_XEN;
        else
                return VIRTUALIZATION_VM_OTHER;
}

static int detect_vm_uml(void) {
        _cleanup_free_ char *cpuinfo_contents = NULL;
        int r;

        /* 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")) {
                log_debug("UML virtualization found in /proc/cpuinfo");
                return VIRTUALIZATION_UML;
        }

        log_debug("No virtualization found in /proc/cpuinfo.");
        return VIRTUALIZATION_NONE;
}

static int detect_vm_zvm(void) {

#if defined(__s390__)
        _cleanup_free_ char *t = NULL;
        int r;

        r = get_proc_field("/proc/sysinfo", "VM00 Control Program", WHITESPACE, &t);
        if (r == -ENOENT)
                return VIRTUALIZATION_NONE;
        if (r < 0)
                return r;

        log_debug("Virtualization %s found in /proc/sysinfo", t);
        if (streq(t, "z/VM"))
                return VIRTUALIZATION_ZVM;
        else
                return VIRTUALIZATION_KVM;
#else
        log_debug("This platform does not support /proc/sysinfo");
        return VIRTUALIZATION_NONE;
#endif
}

/* Returns a short identifier for the various VM implementations */
int detect_vm(void) {
        static thread_local int cached_found = _VIRTUALIZATION_INVALID;
        int r, dmi;

        if (cached_found >= 0)
                return cached_found;

        /* We have to use the correct order here:
         *
         * -> First try to detect Oracle Virtualbox, even if it uses KVM.
         * -> Second try to detect from cpuid, this will report KVM for
         *    whatever software is used even if info in dmi is overwritten.
         * -> Third try to detect from dmi. */

        dmi = detect_vm_dmi();
        if (dmi == VIRTUALIZATION_ORACLE) {
                r = dmi;
                goto finish;
        }

        r = detect_vm_cpuid();
        if (r < 0)
                return r;
        if (r != VIRTUALIZATION_NONE)
                goto finish;

        r = dmi;
        if (r < 0)
                return r;
        if (r != VIRTUALIZATION_NONE)
                goto finish;

        /* x86 xen will most likely be detected by cpuid. If not (most likely
         * because we're not an x86 guest), then we should try the xen capabilities
         * file next. If that's not found, then we check for the high-level
         * hypervisor sysfs file:
         *
         * https://bugs.freedesktop.org/show_bug.cgi?id=77271 */

        r = detect_vm_xen();
        if (r < 0)
                return r;
        if (r != VIRTUALIZATION_NONE)
                goto finish;

        r = detect_vm_hypervisor();
        if (r < 0)
                return r;
        if (r != VIRTUALIZATION_NONE)
                goto finish;

        r = detect_vm_device_tree();
        if (r < 0)
                return r;
        if (r != VIRTUALIZATION_NONE)
                goto finish;

        r = detect_vm_uml();
        if (r < 0)
                return r;
        if (r != VIRTUALIZATION_NONE)
                goto finish;

        r = detect_vm_zvm();
        if (r < 0)
                return r;

finish:
        /* x86 xen Dom0 is detected as XEN in hypervisor and maybe others.
         * In order to detect the Dom0 as not virtualization we need to
         * double-check it */
        if (r == VIRTUALIZATION_XEN && detect_vm_xen_dom0())
                r = VIRTUALIZATION_NONE;

        cached_found = r;
        log_debug("Found VM virtualization %s", virtualization_to_string(r));
        return r;
}
#endif // 0

int detect_container(void) {

        static const struct {
                const char *value;
                int id;
        } value_table[] = {
                { "lxc",            VIRTUALIZATION_LXC            },
                { "lxc-libvirt",    VIRTUALIZATION_LXC_LIBVIRT    },
                { "systemd-nspawn", VIRTUALIZATION_SYSTEMD_NSPAWN },
                { "docker",         VIRTUALIZATION_DOCKER         },
                { "rkt",            VIRTUALIZATION_RKT            },
        };

        static thread_local int cached_found = _VIRTUALIZATION_INVALID;
        _cleanup_free_ char *m = NULL;
        const char *e = NULL;
        unsigned j;
        int r;

        if (cached_found >= 0)
                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) {
                r = VIRTUALIZATION_OPENVZ;
                goto finish;
        }

        if (getpid() == 1) {
                /* If we are PID 1 we can just check our own environment variable, and that's authoritative. */

                e = getenv("container");
                if (isempty(e)) {
                        r = VIRTUALIZATION_NONE;
                        goto finish;
                }

                goto translate_name;
        }

        /* Otherwise, PID 1 might have 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 >= 0) {
                e = m;
                goto translate_name;
        }
        if (r != -ENOENT)
                return log_debug_errno(r, "Failed to read /run/systemd/container: %m");

        /* 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) {
                e = m;
                goto translate_name;
        }
        if (r < 0) /* This only works if we have CAP_SYS_PTRACE, hence let's better ignore failures here */
                log_debug_errno(r, "Failed to read $container of PID 1, ignoring: %m");

        /* Interestingly /proc/1/sched actually shows the host's PID for what we see as PID 1. Hence, if the PID shown
         * there is not 1, we know we are in a PID namespace. and hence a container. */
        r = read_one_line_file("/proc/1/sched", &m);
        if (r >= 0) {
                const char *t;

                t = strrchr(m, '(');
                if (!t)
                        return -EIO;

                if (!startswith(t, "(1,")) {
                        r = VIRTUALIZATION_CONTAINER_OTHER;
                        goto finish;
                }
        } else if (r != -ENOENT)
                return r;

        /* If that didn't work, give up, assume no container manager. */
        r = VIRTUALIZATION_NONE;
        goto finish;

translate_name:
        for (j = 0; j < ELEMENTSOF(value_table); j++)
                if (streq(e, value_table[j].value)) {
                        r = value_table[j].id;
                        goto finish;
                }

        r = VIRTUALIZATION_CONTAINER_OTHER;

finish:
        log_debug("Found container virtualization %s.", virtualization_to_string(r));
        cached_found = r;
        return r;
}

#if 0 /// UNNEEDED by elogind
int detect_virtualization(void) {
        int r;

        r = detect_container();
        if (r == 0)
                r = detect_vm();

        return r;
}

static int userns_has_mapping(const char *name) {
        _cleanup_fclose_ FILE *f = NULL;
        _cleanup_free_ char *buf = NULL;
        size_t n_allocated = 0;
        ssize_t n;
        uint32_t a, b, c;
        int r;

        f = fopen(name, "re");
        if (!f) {
                log_debug_errno(errno, "Failed to open %s: %m", name);
                return errno == ENOENT ? false : -errno;
        }

        n = getline(&buf, &n_allocated, f);
        if (n < 0) {
                if (feof(f)) {
                        log_debug("%s is empty, we're in an uninitialized user namespace", name);
                        return true;
                }

                return log_debug_errno(errno, "Failed to read %s: %m", name);
        }

        r = sscanf(buf, "%"PRIu32" %"PRIu32" %"PRIu32, &a, &b, &c);
        if (r < 3)
                return log_debug_errno(errno, "Failed to parse %s: %m", name);

        if (a == 0 && b == 0 && c == UINT32_MAX) {
                /* The kernel calls mappings_overlap() and does not allow overlaps */
                log_debug("%s has a full 1:1 mapping", name);
                return false;
        }

        /* Anything else implies that we are in a user namespace */
        log_debug("Mapping found in %s, we're in a user namespace", name);
        return true;
}

int running_in_userns(void) {
        _cleanup_free_ char *line = NULL;
        int r;

        r = userns_has_mapping("/proc/self/uid_map");
        if (r != 0)
                return r;

        r = userns_has_mapping("/proc/self/gid_map");
        if (r != 0)
                return r;

        /* "setgroups" file was added in kernel v3.18-rc6-15-g9cc46516dd. It is also
         * possible to compile a kernel without CONFIG_USER_NS, in which case "setgroups"
         * also does not exist. We cannot distinguish those two cases, so assume that
         * we're running on a stripped-down recent kernel, rather than on an old one,
         * and if the file is not found, return false.
         */
        r = read_one_line_file("/proc/self/setgroups", &line);
        if (r < 0) {
                log_debug_errno(r, "/proc/self/setgroups: %m");
                return r == -ENOENT ? false : r;
        }

        truncate_nl(line);
        r = streq(line, "deny");
        /* See user_namespaces(7) for a description of this "setgroups" contents. */
        log_debug("/proc/self/setgroups contains \"%s\", %s user namespace", line, r ? "in" : "not in");
        return r;
}
#endif // 0

int running_in_chroot(void) {
        int ret;

#if 0 /// elogind does not allow to ignore chroots, we are never init!
        if (getenv_bool("SYSTEMD_IGNORE_CHROOT") > 0)
                return 0;
#endif // 0

        ret = files_same("/proc/1/root", "/");
        if (ret < 0)
                return ret;

        return ret == 0;
}

static const char *const virtualization_table[_VIRTUALIZATION_MAX] = {
        [VIRTUALIZATION_NONE] = "none",
        [VIRTUALIZATION_KVM] = "kvm",
        [VIRTUALIZATION_QEMU] = "qemu",
        [VIRTUALIZATION_BOCHS] = "bochs",
        [VIRTUALIZATION_XEN] = "xen",
        [VIRTUALIZATION_UML] = "uml",
        [VIRTUALIZATION_VMWARE] = "vmware",
        [VIRTUALIZATION_ORACLE] = "oracle",
        [VIRTUALIZATION_MICROSOFT] = "microsoft",
        [VIRTUALIZATION_ZVM] = "zvm",
        [VIRTUALIZATION_PARALLELS] = "parallels",
        [VIRTUALIZATION_BHYVE] = "bhyve",
        [VIRTUALIZATION_VM_OTHER] = "vm-other",

        [VIRTUALIZATION_SYSTEMD_NSPAWN] = "systemd-nspawn",
        [VIRTUALIZATION_LXC_LIBVIRT] = "lxc-libvirt",
        [VIRTUALIZATION_LXC] = "lxc",
        [VIRTUALIZATION_OPENVZ] = "openvz",
        [VIRTUALIZATION_DOCKER] = "docker",
        [VIRTUALIZATION_RKT] = "rkt",
        [VIRTUALIZATION_CONTAINER_OTHER] = "container-other",
};

DEFINE_STRING_TABLE_LOOKUP(virtualization, int);