src/shared: import many code cleanups from upstream

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>

1 files changed, 328 insertions, 0 deletions

diff --git a/src/shared/virt.c b/src/shared/virt.c
new file mode 100644
index 0000000000..2144341e83
--- /dev/null
+++ b/src/shared/virt.c
@@ -0,0 +1,328 @@
+/*-*- 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"
+
+#if 0
+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;
+}
+#endif
+
+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) {
+                        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
+                _id = "other";
+
+        r = 1;
+
+finish:
+        cached_found = r;
+
+        cached_id = _id;
+        if (id)
+                *id = _id;
+
+        return r;
+}