Re: [Qemu-devel] [PATCH v7 1/3] qemu-ga: add guest-get-osinfo command

[Marc-André Lureau]

On Mon, Jul 3, 2017 at 1:40 PM Tomáš Golembiovský <address@hidden>
wrote:

> Add a new 'guest-get-osinfo' command for reporting basic information of
> the guest operating system. This includes machine architecture,
> version and release of the kernel and several fields from os-release
> file if it is present (as defined in [1]).
>
> [1] https://www.freedesktop.org/software/systemd/man/os-release.html
>
> Signed-off-by: Vinzenz Feenstra <address@hidden>
> Signed-off-by: Tomáš Golembiovský <address@hidden>
> ---
>  qga/commands-posix.c | 136 +++++++++++++++++++++++++++++++++++++
>  qga/commands-win32.c | 185
> +++++++++++++++++++++++++++++++++++++++++++++++++++
>  qga/qapi-schema.json |  65 ++++++++++++++++++
>  3 files changed, 386 insertions(+)
>
> diff --git a/qga/commands-posix.c b/qga/commands-posix.c
> index d8e412275e..7a933a5f12 100644
> --- a/qga/commands-posix.c
> +++ b/qga/commands-posix.c
> @@ -13,6 +13,7 @@
>
>  #include "qemu/osdep.h"
>  #include <sys/ioctl.h>
> +#include <sys/utsname.h>
>  #include <sys/wait.h>
>  #include <dirent.h>
>  #include <utmpx.h>
> @@ -2577,3 +2578,138 @@ GuestUserList *qmp_guest_get_users(Error **err)
>      g_hash_table_destroy(cache);
>      return head;
>  }
> +
> +/* Replace escaped special characters with theire real values. The
> replacement
> + * is done in place -- returned value is in the original string.
> + */
> +static void ga_osrelease_replace_special(gchar *value)
> +{
> +    gchar *p, *p2, quote;
> +
> +    /* Trim the string at first space or semicolon if it is not enclosed
> in
> +     * single or double quotes. */
> +    if ((value[0] != '"') || (value[0] == '\'')) {
> +        p = strchr(value, ' ');
> +        if (p != NULL) {
> +            *p = 0;
> +        }
> +        p = strchr(value, ';');
> +        if (p != NULL) {
> +            *p = 0;
> +        }
> +        return;
> +    }
> +
> +    quote = value[0];
> +    p2 = value;
> +    p = value + 1;
> +    while (*p != 0) {
> +        if (*p == '\\') {
> +            p++;
> +            switch (*p) {
> +            case '$':
> +            case '\'':
> +            case '"':
> +            case '\\':
> +            case '`':
> +                break;
> +            default:
> +                /* Keep literal backslash followed by whatever is there */
> +                p--;
> +                break;
> +            }
> +        } else if (*p == quote) {
> +            *p2 = 0;
> +            break;
> +        }
> +        *(p2++) = *(p++);
> +    }
> +}
> +
> +static GKeyFile *ga_parse_osrelease(const char *fname)
> +{
> +    gboolean ret;
> +    gchar *content = NULL;
> +    gchar *content2 = NULL;
> +    gsize len;
> +    GError *err = NULL;
> +    GKeyFile *keys = g_key_file_new();
> +    const char *group = "[os-release]\n";
> +
> +    ret = g_file_get_contents(fname, &content, &len, &err);
> +    if (ret != TRUE) {
>

I would rather have

if (!g_file_get_contents(..))

same for the calls below,


> +        slog("failed to read '%s', error: %s", fname, err->message);
> +        goto fail;
> +    }
> +
> +    ret = g_utf8_validate(content, len, NULL);
> +    if (ret != TRUE) {
> +        slog("file is not utf-8 encoded: %s", fname);
> +        goto fail;
> +    }
> +    content2 = g_strdup_printf("%s%s", group, content);
> +    len += strlen(group);
>

I wouldn't bother with len, and pass -1 to load_from_data


> +
> +    ret = g_key_file_load_from_data(keys, content2, len, G_KEY_FILE_NONE,
> +        &err);
> +    if (ret != TRUE) {
> +        slog("failed to parse file '%s', error: %s", fname, err->message);
> +        goto fail;
> +    }
> +
> +    g_free(content);
> +    g_free(content2);
> +    return keys;
> +
> +fail:
> +    g_error_free(err);
> +    g_free(content);
> +    g_free(content2);
> +    g_key_file_free(keys);
> +    return NULL;
> +}
> +
> +GuestOSInfo *qmp_guest_get_osinfo(Error **errp)
> +{
> +    GuestOSInfo *info = g_new0(GuestOSInfo, 1);
> +
> +    struct utsname kinfo = {0};
> +    if (uname(&kinfo) != 0) {
> +        error_setg_errno(errp, errno, "uname failed");
>

leaks info here

Alternatively, you could make it non-fatal and keep going with a warning
only?


> +        return NULL;
> +    }
> +
> +    info->kernel_version = g_strdup(kinfo.version);
> +    info->kernel_release = g_strdup(kinfo.release);
> +    info->machine_hardware = g_strdup(kinfo.machine);
> +
> +    GKeyFile *osrelease = ga_parse_osrelease("/etc/os-release");
> +    if (osrelease == NULL) {
> +        osrelease = ga_parse_osrelease("/usr/lib/os-release");
> +    }
> +
> +    if (osrelease != NULL) {
> +        char *value;
> +
> +#define GET_FIELD(field, osfield) do { \
> +    value = g_key_file_get_value(osrelease, "os-release", osfield, NULL);
> \
> +    if (value != NULL) { \
> +        ga_osrelease_replace_special(value); \
> +        info->has_ ## field = true; \
> +        info->field = value; \
> +    } \
> +} while (0)
> +        GET_FIELD(id, "ID");
> +        GET_FIELD(name, "NAME");
> +        GET_FIELD(pretty_name, "PRETTY_NAME");
> +        GET_FIELD(version, "VERSION");
> +        GET_FIELD(version_id, "VERSION_ID");
> +        GET_FIELD(variant, "VARIANT");
> +        GET_FIELD(variant_id, "VARIANT_ID");
> +#undef GET_FIELD
> +
> +        g_key_file_free(osrelease);
> +    }
> +
> +    return info;
> +}
> diff --git a/qga/commands-win32.c b/qga/commands-win32.c
> index 439d229225..e471f5561b 100644
> --- a/qga/commands-win32.c
> +++ b/qga/commands-win32.c
> @@ -1639,3 +1639,188 @@ GuestUserList *qmp_guest_get_users(Error **err)
>      return NULL;
>  #endif
>  }
> +
> +typedef struct _ga_matrix_lookup_t {
> +    int major;
> +    int minor;
> +    char const *version;
> +    char const *version_id;
> +} ga_matrix_lookup_t;
> +
> +static ga_matrix_lookup_t const WIN_VERSION_MATRIX[2][8] = {
> +    {
> +        /* Desktop editions */
> +        { 5, 0, "Microsoft Windows 2000",   "2000"},
> +        { 5, 1, "Microsoft Windows XP",     "xp"},
> +        { 6, 0, "Microsoft Windows Vista",  "vista"},
> +        { 6, 1, "Microsoft Windows 7"       "7"},
> +        { 6, 2, "Microsoft Windows 8",      "8"},
> +        { 6, 3, "Microsoft Windows 8.1",    "8.1"},
> +        {10, 0, "Microsoft Windows 10",     "10"},
> +        { 0, 0, 0}
> +    },{
> +        /* Server editions */
> +        { 5, 2, "Microsoft Windows Server 2003",        "2003"},
> +        { 6, 0, "Microsoft Windows Server 2008",        "2008"},
> +        { 6, 1, "Microsoft Windows Server 2008 R2",     "2008r2"},
> +        { 6, 2, "Microsoft Windows Server 2012",        "2012"},
> +        { 6, 3, "Microsoft Windows Server 2012 R2",     "2012r2"},
> +        {10, 0, "Microsoft Windows Server 2016",        "2016"},
> +        { 0, 0, 0},
> +        { 0, 0, 0}
> +    }
> +};
> +
> +static void ga_get_win_version(RTL_OSVERSIONINFOEXW *info, Error **errp)
> +{
> +    typedef NTSTATUS(WINAPI * rtl_get_version_t)(
> +        RTL_OSVERSIONINFOEXW *os_version_info_ex);
> +
> +    info->dwOSVersionInfoSize = sizeof(RTL_OSVERSIONINFOEXW);
> +
> +    HMODULE module = GetModuleHandle("ntdll");
> +    PVOID fun = GetProcAddress(module, "RtlGetVersion");
> +    if (fun == NULL) {
> +        error_setg(errp, QERR_QGA_COMMAND_FAILED,
> +            "Failed to get address of RtlGetVersion");
> +        return;
> +    }
> +
> +    rtl_get_version_t rtl_get_version = (rtl_get_version_t)fun;
> +    rtl_get_version(info);
> +    return;
> +}
> +
> +static char *ga_get_win_name(OSVERSIONINFOEXW const *os_version, bool id)
> +{
> +    DWORD major = os_version->dwMajorVersion;
> +    DWORD minor = os_version->dwMinorVersion;
> +    int tbl_idx = (os_version->wProductType != VER_NT_WORKSTATION);
> +    ga_matrix_lookup_t const *table = WIN_VERSION_MATRIX[tbl_idx];
> +    while (table->version != NULL) {
> +        if (major == table->major && minor == table->minor) {
> +            if (id) {
> +                return g_strdup(table->version_id);
> +            } else {
> +                return g_strdup(table->version);
> +            }
> +        }
> +        ++table;
> +    }
> +    slog("failed to lookup Windows version: major=%lu, minor=%lu",
> +        major, minor);
> +    return g_strdup("N/A");
> +}
> +
> +static char *ga_get_win_product_name(Error **errp)
> +{
> +    HKEY key = NULL;
> +    DWORD size = 128;
> +    char *result = g_malloc0(size);
> +    LONG err = ERROR_SUCCESS;
> +
> +    err = RegOpenKeyA(HKEY_LOCAL_MACHINE,
> +                      "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion",
> +                      &key);
> +    if (err != ERROR_SUCCESS) {
> +        error_setg_win32(errp, err, "failed to open registry key");
> +        goto fail;
> +    }
> +
> +    err = RegQueryValueExA(key, "ProductName", NULL, NULL,
> +                            (LPBYTE)result, &size);
> +    if (err == ERROR_MORE_DATA) {
> +        slog("ProductName longer than expected (%lu bytes), retrying",
> +                size);
> +        g_free(result);
> +        result = NULL;
> +        if (size > 0) {
> +            result = g_malloc0(size);
> +            err = RegQueryValueExA(key, "ProductName", NULL, NULL,
> +                                    (LPBYTE)result, &size);
> +        }
> +    }
> +    if (err != ERROR_SUCCESS) {
> +        error_setg_win32(errp, err, "failed to retrive ProductName");
> +        goto fail;
> +    }
> +
> +    return result;
> +
> +fail:
> +    g_free(result);
> +    return NULL;
> +}
> +
> +static char *ga_get_current_arch(void)
> +{
> +    SYSTEM_INFO info;
> +    GetNativeSystemInfo(&info);
> +    char *result = NULL;
> +    switch (info.wProcessorArchitecture) {
> +    case PROCESSOR_ARCHITECTURE_AMD64:
> +        result = g_strdup("x86_64");
> +        break;
> +    case PROCESSOR_ARCHITECTURE_ARM:
> +        result = g_strdup("arm");
> +        break;
> +    case PROCESSOR_ARCHITECTURE_IA64:
> +        result = g_strdup("ia64");
> +        break;
> +    case PROCESSOR_ARCHITECTURE_INTEL:
> +        result = g_strdup("x86");
> +        break;
> +    case PROCESSOR_ARCHITECTURE_UNKNOWN:
> +    default:
> +        slog("unknown processor architecture 0x%0x",
> +            info.wProcessorArchitecture);
> +        result = g_strdup("unknown");
> +        break;
> +    }
> +    return result;
> +}
> +
> +GuestOSInfo *qmp_guest_get_osinfo(Error **errp)
> +{
> +    Error *local_err = NULL;
> +    OSVERSIONINFOEXW os_version = {0};
> +
> +    ga_get_win_version(&os_version, &local_err);
> +    if (local_err) {
> +        error_propagate(errp, local_err);
> +        return NULL;
> +    }
> +
> +    bool server = os_version.wProductType != VER_NT_WORKSTATION;
> +    char *product_name = ga_get_win_product_name(&local_err);
> +    if (product_name == NULL) {
> +        error_propagate(errp, local_err);
> +        return NULL;
> +    }
> +
> +    GuestOSInfo *info = g_new0(GuestOSInfo, 1);
> +
> +    info->kernel_version = g_strdup_printf("%lu.%lu",
> +        os_version.dwMajorVersion,
> +        os_version.dwMinorVersion);
> +    info->kernel_release = g_strdup_printf("%lu",
> +        os_version.dwBuildNumber);
> +    info->machine_hardware = ga_get_current_arch();
> +
> +    info->has_id = true;
> +    info->id = g_strdup("mswindows");
> +    info->has_name = true;
> +    info->name = g_strdup("Microsoft Windows");
> +    info->has_pretty_name = true;
> +    info->pretty_name = product_name;
> +    info->has_version = true;
> +    info->version = ga_get_win_name(&os_version, false);
> +    info->has_version_id = true;
> +    info->version_id = ga_get_win_name(&os_version, true);
> +    info->has_variant = true;
> +    info->variant = g_strdup(server ? "server" : "client");
> +    info->has_variant_id = true;
> +    info->variant_id = g_strdup(server ? "server" : "client");
> +
> +    return info;
> +}
> diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
> index 03743ab905..3d9478c10b 100644
> --- a/qga/qapi-schema.json
> +++ b/qga/qapi-schema.json
> @@ -1126,3 +1126,68 @@
>  ##
>  { 'command': 'guest-get-timezone',
>    'returns': 'GuestTimezone' }
> +
> +##
> +# @GuestOSInfo:
> +#
> +# @kernel-release:
> +#     * _POSIX:_ release field returned by uname(2)
> +#     * _Windows:_ version number of the OS
>

Does _foo_ really make the result more clear, I am not convinced, * foo:
already stands out imho.

+# @kernel-version:
> +#     * _POSIX:_ version field returned by uname(2)
> +#     * _Windows:_ build number of the OS
> +# @machine-hardware:
> +#     * _POSIX:_ machine field returned by uname(2)
> +#     * _Windows:_ architecture of the hardware
> +# @id:
> +#     * _POSIX:_ as defined by os-release(5)
> +#     * _Windows:_ contains string "mswindows"
> +# @name:
> +#     * _POSIX:_ as defined by os-release(5)
> +#     * _Windows:_ contains string "Microsoft Windows"
> +# @pretty-name:
> +#     * _POSIX:_ as defined by os-release(5)
> +#     * _Windows:_ product name, e.g. "Microsoft Windows 10 Enterprise"
> +# @version:
> +#     * _POSIX:_ as defined by os-release(5)
> +#     * _Windows:_ long version string, e.g. "Microsoft Windows Server
> 2008"
> +# @version-id:
> +#     * _POSIX:_ as defined by os-release(5)
> +#     * _Windows:_ short version identifier, e.g. "7" or "20012r2"
> +# @variant:
> +#     * _POSIX:_ as defined by os-release(5)
> +#     * _Windows:_ contains string "server" or "client"
> +# @variant-id:
> +#     * _POSIX:_ as defined by os-release(5)
> +#     * _Windows:_ contains string "server" or "client"
> +#
> +# Notes:
> +#
> +# On POSIX systems the fields @id, @name, @pretty-name, @version,
> @version-id,
> +# @variant and @variant-id follow the definition specified in
> os-release(5).
> +# Refer to the manual page for exact description of the fields. Their
> values
> +# are taken from the os-release file. If the file is not present in the
> system,
> +# or the values are not present in the file, the fields are not included.
> +#
> +# On Windows the values are filled from information gathered from the
> system.
> +#
> +# Since: 2.10
> +##
> +{ 'struct': 'GuestOSInfo',
> +  'data': {
> +      'kernel-release': 'str', 'kernel-version': 'str',
> +      'machine-hardware': 'str', '*id': 'str', '*name': 'str',
> +      '*pretty-name': 'str', '*version': 'str', '*version-id': 'str',
> +      '*variant': 'str', '*variant-id': 'str' } }
> +
> +##
> +# @guest-get-osinfo:
> +#
> +# Retrieve guest operating system information
> +#
> +# Returns: @GuestOSInfo
> +#
> +# Since: 2.10
> +##
> +{ 'command': 'guest-get-osinfo',
> +  'returns': 'GuestOSInfo' }
> --
> 2.13.1
>

Looks good to me otherwise
-- 
Marc-André Lureau