util: move virtualization detection into its own files, and extend return codes

1 files changed, 314 insertions, 0 deletions

diff --git a/src/virt.c b/src/virt.c
new file mode 100644
index 0000000000..380fabded2
--- /dev/null
+++ b/src/virt.c
@@ -0,0 +1,314 @@
+/*-*- 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 General Public License as published by
+  the Free Software Foundation; either version 2 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.
+
+  You should have received a copy of the GNU 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"
+
+/* Returns a short identifier for the various VM implementations */
+int detect_vm(const char **id) {
+
+#if defined(__i386__) || defined(__x86_64__)
+
+        /* 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";
+
+        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;
+        unsigned i;
+        const char *j, *k;
+        bool hypervisor;
+
+        /* http://lwn.net/Articles/301888/ */
+        zero(sig);
+
+#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)) {
+
+                                if (id)
+                                        *id = k;
+
+                                return 1;
+                        }
+        }
+
+        for (i = 0; i < ELEMENTSOF(dmi_vendors); i++) {
+                char *s;
+                int r;
+                const char *found = NULL;
+
+                if ((r = read_one_line_file(dmi_vendors[i], &s)) < 0) {
+                        if (r != -ENOENT)
+                                return r;
+
+                        continue;
+                }
+
+                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;
+        }
+
+#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;
+
+        if (running_in_chroot() > 0) {
+
+                if (id)
+                        *id = "chroot";
+
+                return 1;
+        }
+
+        /* /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;
+        }
+
+        f = fopen("/proc/1/environ", "re");
+        if (f) {
+                bool done = false;
+
+                do {
+                        char line[LINE_MAX];
+                        unsigned i;
+
+                        for (i = 0; i < sizeof(line)-1; i++) {
+                                int c;
+
+                                c = getc(f);
+                                if (_unlikely_(c == EOF)) {
+                                        done = true;
+                                        break;
+                                } else if (c == 0)
+                                        break;
+
+                                line[i] = c;
+                        }
+                        line[i] = 0;
+
+                        if (streq(line, "container=lxc")) {
+                                fclose(f);
+
+                                if (id)
+                                        *id = "lxc";
+                                return 1;
+
+                        } else if (streq(line, "container=systemd-nspawn")) {
+                                fclose(f);
+
+                                if (id)
+                                        *id = "systemd-nspawn";
+                                return 1;
+
+                        } else if (startswith(line, "container=")) {
+                                fclose(f);
+
+                                if (id)
+                                        *id = "other";
+                                return 1;
+                        }
+
+                } while (!done);
+
+                fclose(f);
+        }
+
+        f = fopen("/proc/self/cgroup", "re");
+        if (f) {
+
+                for (;;) {
+                        char line[LINE_MAX], *p;
+
+                        if (!fgets(line, sizeof(line), f))
+                                break;
+
+                        p = strchr(strstrip(line), ':');
+                        if (!p)
+                                continue;
+
+                        if (strncmp(p, ":ns:", 4))
+                                continue;
+
+                        if (!streq(p, ":ns:/")) {
+                                fclose(f);
+
+                                if (id)
+                                        *id = "pidns";
+
+                                return 1;
+                        }
+                }
+
+                fclose(f);
+        }
+
+        return 0;
+}
+
+/* Returns a short identifier for the various VM/container implementations */
+Virtualization detect_virtualization(const char **id) {
+
+        static __thread Virtualization cached_virt = _VIRTUALIZATION_INVALID;
+        static __thread const char *cached_id = NULL;
+
+        const char *_id;
+        int r;
+        Virtualization v;
+
+        if (_likely_(cached_virt >= 0)) {
+
+                if (id && cached_virt > 0)
+                        *id = cached_id;
+
+                return cached_virt;
+        }
+
+        r = detect_container(&_id);
+        if (r < 0) {
+                v = r;
+                goto finish;
+        } else if (r > 0) {
+                v = VIRTUALIZATION_CONTAINER;
+                goto finish;
+        }
+
+        r = detect_vm(&_id);
+        if (r < 0) {
+                v = r;
+                goto finish;
+        } else if (r > 0) {
+                v = VIRTUALIZATION_VM;
+                goto finish;
+        }
+
+        v = VIRTUALIZATION_NONE;
+
+finish:
+        if (v > 0) {
+                cached_id = _id;
+
+                if (id)
+                        *id = _id;
+        }
+
+        if (v >= 0)
+                cached_virt = v;
+
+        return v;
+}