From f38bddc70a6ec7c1ab26d9a8b06eed25d618ae22 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 16:30:14 +0200 Subject: Adding upstream version 3.38.2.1. Signed-off-by: Daniel Baumann --- daemon/gdm-display-access-file.c | 606 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 606 insertions(+) create mode 100644 daemon/gdm-display-access-file.c (limited to 'daemon/gdm-display-access-file.c') diff --git a/daemon/gdm-display-access-file.c b/daemon/gdm-display-access-file.c new file mode 100644 index 0000000..87e523e --- /dev/null +++ b/daemon/gdm-display-access-file.c @@ -0,0 +1,606 @@ +/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*- + * + * gdm-display-access-file.c - Abstraction around xauth cookies + * + * Copyright (C) 2007 Ray Strode + * + * This program 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, or (at your option) + * any later version. + * + * This program 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 this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +#include "config.h" + +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include + +#include "gdm-display-access-file.h" +#include "gdm-common.h" + +struct _GdmDisplayAccessFile +{ + GObject parent; + + char *username; + FILE *fp; + char *path; +}; + +#ifndef GDM_DISPLAY_ACCESS_COOKIE_SIZE +#define GDM_DISPLAY_ACCESS_COOKIE_SIZE 16 +#endif + +#ifndef O_BINARY +#define O_BINARY 0 +#endif + +static void gdm_display_access_file_finalize (GObject * object); + +enum +{ + PROP_0 = 0, + PROP_USERNAME, + PROP_PATH +}; + +G_DEFINE_TYPE (GdmDisplayAccessFile, gdm_display_access_file, G_TYPE_OBJECT) + +static void +gdm_display_access_file_get_property (GObject *object, + guint prop_id, + GValue *value, + GParamSpec *pspec) +{ + GdmDisplayAccessFile *access_file; + + access_file = GDM_DISPLAY_ACCESS_FILE (object); + + switch (prop_id) { + case PROP_USERNAME: + g_value_set_string (value, access_file->username); + break; + + case PROP_PATH: + g_value_set_string (value, access_file->path); + break; + + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + } +} + +static void +gdm_display_access_file_set_property (GObject *object, + guint prop_id, + const GValue *value, + GParamSpec *pspec) +{ + GdmDisplayAccessFile *access_file; + + access_file = GDM_DISPLAY_ACCESS_FILE (object); + + switch (prop_id) { + case PROP_USERNAME: + g_assert (access_file->username == NULL); + access_file->username = g_value_dup_string (value); + break; + + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + } +} + +static void +gdm_display_access_file_class_init (GdmDisplayAccessFileClass *access_file_class) +{ + GObjectClass *object_class; + GParamSpec *param_spec; + + object_class = G_OBJECT_CLASS (access_file_class); + + object_class->finalize = gdm_display_access_file_finalize; + object_class->get_property = gdm_display_access_file_get_property; + object_class->set_property = gdm_display_access_file_set_property; + + param_spec = g_param_spec_string ("username", + "Username", + "Owner of Xauthority file", + NULL, + G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY); + g_object_class_install_property (object_class, PROP_USERNAME, param_spec); + param_spec = g_param_spec_string ("path", + "Path", + "Path to Xauthority file", + NULL, + G_PARAM_READABLE); + g_object_class_install_property (object_class, PROP_PATH, param_spec); +} + +static void +gdm_display_access_file_init (GdmDisplayAccessFile *access_file) +{ +} + +static void +gdm_display_access_file_finalize (GObject *object) +{ + GdmDisplayAccessFile *file; + GObjectClass *parent_class; + + file = GDM_DISPLAY_ACCESS_FILE (object); + parent_class = G_OBJECT_CLASS (gdm_display_access_file_parent_class); + + if (file->fp != NULL) { + gdm_display_access_file_close (file); + } + g_assert (file->path == NULL); + + if (file->username != NULL) { + g_free (file->username); + file->username = NULL; + g_object_notify (object, "username"); + } + + if (parent_class->finalize != NULL) { + parent_class->finalize (object); + } +} + +GQuark +gdm_display_access_file_error_quark (void) +{ + static GQuark error_quark = 0; + + if (error_quark == 0) { + error_quark = g_quark_from_static_string ("gdm-display-access-file"); + } + + return error_quark; +} + +GdmDisplayAccessFile * +gdm_display_access_file_new (const char *username) +{ + GdmDisplayAccessFile *access_file; + g_return_val_if_fail (username != NULL, NULL); + + access_file = g_object_new (GDM_TYPE_DISPLAY_ACCESS_FILE, + "username", username, + NULL); + + return access_file; +} + +static gboolean +_get_uid_and_gid_for_user (const char *username, + uid_t *uid, + gid_t *gid) +{ + struct passwd *passwd_entry; + + g_assert (username != NULL); + g_assert (uid != NULL); + g_assert (gid != NULL); + + errno = 0; + gdm_get_pwent_for_name (username, &passwd_entry); + + if (passwd_entry == NULL) { + return FALSE; + } + + *uid = passwd_entry->pw_uid; + *gid = passwd_entry->pw_gid; + + return TRUE; +} + +static void +clean_up_stale_auth_subdirs (void) +{ + GDir *dir; + const char *filename; + + dir = g_dir_open (GDM_XAUTH_DIR, 0, NULL); + + if (dir == NULL) { + return; + } + + while ((filename = g_dir_read_name (dir)) != NULL) { + char *path; + + path = g_build_filename (GDM_XAUTH_DIR, filename, NULL); + + /* Will only succeed if the directory is empty + */ + g_rmdir (path); + g_free (path); + } + g_dir_close (dir); +} + +static FILE * +_create_xauth_file_for_user (const char *username, + char **filename, + GError **error) +{ + char *template; + const char *dir_name; + char *auth_filename; + int fd; + FILE *fp; + uid_t uid; + gid_t gid; + + g_assert (filename != NULL); + + *filename = NULL; + + template = NULL; + auth_filename = NULL; + fp = NULL; + fd = -1; + + /* Create directory if not exist, then set permission 0711 and ownership root:gdm */ + if (g_file_test (GDM_XAUTH_DIR, G_FILE_TEST_IS_DIR) == FALSE) { + g_remove (GDM_XAUTH_DIR); + if (g_mkdir (GDM_XAUTH_DIR, 0711) != 0) { + g_set_error (error, + G_FILE_ERROR, + g_file_error_from_errno (errno), + "%s", g_strerror (errno)); + goto out; + } + + g_chmod (GDM_XAUTH_DIR, 0711); + _get_uid_and_gid_for_user (GDM_USERNAME, &uid, &gid); + if (chown (GDM_XAUTH_DIR, 0, gid) != 0) { + g_warning ("Unable to change owner of '%s'", + GDM_XAUTH_DIR); + } + } else { + /* if it does exist make sure it has correct mode 0711 */ + g_chmod (GDM_XAUTH_DIR, 0711); + + /* and clean up any stale auth subdirs */ + clean_up_stale_auth_subdirs (); + } + + if (!_get_uid_and_gid_for_user (username, &uid, &gid)) { + g_set_error (error, + GDM_DISPLAY_ERROR, + GDM_DISPLAY_ERROR_GETTING_USER_INFO, + _("could not find user “%s” on system"), + username); + goto out; + + } + + template = g_strdup_printf (GDM_XAUTH_DIR + "/auth-for-%s-XXXXXX", + username); + + g_debug ("GdmDisplayAccessFile: creating xauth directory %s", template); + /* Initially create with mode 01700 then later chmod after we create database */ + errno = 0; + dir_name = g_mkdtemp (template); + if (dir_name == NULL) { + g_set_error (error, + G_FILE_ERROR, + g_file_error_from_errno (errno), + "Unable to create temp dir from tempalte '%s': %s", + template, + g_strerror (errno)); + goto out; + } + + g_debug ("GdmDisplayAccessFile: chowning %s to %u:%u", + dir_name, (guint)uid, (guint)gid); + errno = 0; + if (chown (dir_name, uid, gid) < 0) { + g_set_error (error, + G_FILE_ERROR, + g_file_error_from_errno (errno), + "Unable to change permission of '%s': %s", + dir_name, + g_strerror (errno)); + goto out; + } + + auth_filename = g_build_filename (dir_name, "database", NULL); + + g_debug ("GdmDisplayAccessFile: creating %s", auth_filename); + /* mode 00600 */ + errno = 0; + fd = g_open (auth_filename, + O_RDWR | O_CREAT | O_EXCL | O_BINARY, + S_IRUSR | S_IWUSR); + + if (fd < 0) { + g_set_error (error, + G_FILE_ERROR, + g_file_error_from_errno (errno), + "Unable to open '%s': %s", + auth_filename, + g_strerror (errno)); + goto out; + } + + g_debug ("GdmDisplayAccessFile: chowning %s to %u:%u", auth_filename, (guint)uid, (guint)gid); + errno = 0; + if (fchown (fd, uid, gid) < 0) { + g_set_error (error, + G_FILE_ERROR, + g_file_error_from_errno (errno), + "Unable to change owner for '%s': %s", + auth_filename, + g_strerror (errno)); + close (fd); + fd = -1; + goto out; + } + + /* now open up permissions on per-session directory */ + g_debug ("GdmDisplayAccessFile: chmoding %s to 0711", dir_name); + g_chmod (dir_name, 0711); + + errno = 0; + fp = fdopen (fd, "w"); + if (fp == NULL) { + g_set_error (error, + G_FILE_ERROR, + g_file_error_from_errno (errno), + "%s", g_strerror (errno)); + close (fd); + fd = -1; + goto out; + } + + *filename = auth_filename; + auth_filename = NULL; + + /* don't close it */ + fd = -1; +out: + g_free (template); + g_free (auth_filename); + if (fd != -1) { + close (fd); + } + + return fp; +} + +gboolean +gdm_display_access_file_open (GdmDisplayAccessFile *file, + GError **error) +{ + GError *create_error; + + g_return_val_if_fail (file != NULL, FALSE); + g_return_val_if_fail (file->fp == NULL, FALSE); + g_return_val_if_fail (file->path == NULL, FALSE); + + create_error = NULL; + file->fp = _create_xauth_file_for_user (file->username, + &file->path, + &create_error); + + if (file->fp == NULL) { + g_propagate_error (error, create_error); + return FALSE; + } + + return TRUE; +} + +static void +_get_auth_info_for_display (GdmDisplayAccessFile *file, + GdmDisplay *display, + unsigned short *family, + unsigned short *address_length, + char **address, + unsigned short *number_length, + char **number, + unsigned short *name_length, + char **name) +{ + int display_number; + gboolean is_local; + + gdm_display_is_local (display, &is_local, NULL); + + if (is_local) { + /* We could just use FamilyWild here except xauth + * (and by extension su and ssh) doesn't support it yet + * + * https://bugs.freedesktop.org/show_bug.cgi?id=43425 + */ + char localhost[HOST_NAME_MAX + 1] = ""; + *family = FamilyLocal; + if (gethostname (localhost, HOST_NAME_MAX) == 0) { + *address = g_strdup (localhost); + } else { + *address = g_strdup ("localhost"); + } + } else { + *family = FamilyWild; + gdm_display_get_remote_hostname (display, address, NULL); + } + *address_length = strlen (*address); + + gdm_display_get_x11_display_number (display, &display_number, NULL); + *number = g_strdup_printf ("%d", display_number); + *number_length = strlen (*number); + + *name = g_strdup ("MIT-MAGIC-COOKIE-1"); + *name_length = strlen (*name); +} + +gboolean +gdm_display_access_file_add_display (GdmDisplayAccessFile *file, + GdmDisplay *display, + char **cookie, + gsize *cookie_size, + GError **error) +{ + GError *add_error; + gboolean display_added; + + g_return_val_if_fail (file != NULL, FALSE); + g_return_val_if_fail (file->path != NULL, FALSE); + g_return_val_if_fail (cookie != NULL, FALSE); + + add_error = NULL; + *cookie = gdm_generate_random_bytes (GDM_DISPLAY_ACCESS_COOKIE_SIZE, + &add_error); + + if (*cookie == NULL) { + g_propagate_error (error, add_error); + return FALSE; + } + + *cookie_size = GDM_DISPLAY_ACCESS_COOKIE_SIZE; + + display_added = gdm_display_access_file_add_display_with_cookie (file, display, + *cookie, + *cookie_size, + &add_error); + if (!display_added) { + g_free (*cookie); + *cookie = NULL; + g_propagate_error (error, add_error); + return FALSE; + } + + return TRUE; +} + +gboolean +gdm_display_access_file_add_display_with_cookie (GdmDisplayAccessFile *file, + GdmDisplay *display, + const char *cookie, + gsize cookie_size, + GError **error) +{ + Xauth auth_entry; + gboolean display_added; + + g_return_val_if_fail (file != NULL, FALSE); + g_return_val_if_fail (file->path != NULL, FALSE); + g_return_val_if_fail (cookie != NULL, FALSE); + + _get_auth_info_for_display (file, display, + &auth_entry.family, + &auth_entry.address_length, + &auth_entry.address, + &auth_entry.number_length, + &auth_entry.number, + &auth_entry.name_length, + &auth_entry.name); + + auth_entry.data = (char *) cookie; + auth_entry.data_length = cookie_size; + + /* FIXME: We should lock the file in case the X server is + * trying to use it, too. + */ + if (!XauWriteAuth (file->fp, &auth_entry) + || fflush (file->fp) == EOF) { + g_set_error (error, + G_FILE_ERROR, + g_file_error_from_errno (errno), + "%s", g_strerror (errno)); + display_added = FALSE; + } else { + display_added = TRUE; + } + + /* If we wrote a FamilyLocal entry, we still want a FamilyWild + * entry, because it's more resiliant against hostname changes + * + */ + if (auth_entry.family == FamilyLocal) { + auth_entry.family = FamilyWild; + + if (XauWriteAuth (file->fp, &auth_entry) + && fflush (file->fp) != EOF) { + display_added = TRUE; + } + } + + g_free (auth_entry.address); + g_free (auth_entry.number); + g_free (auth_entry.name); + + return display_added; +} + +void +gdm_display_access_file_close (GdmDisplayAccessFile *file) +{ + char *auth_dir; + + g_return_if_fail (file != NULL); + g_return_if_fail (file->fp != NULL); + g_return_if_fail (file->path != NULL); + + errno = 0; + if (g_unlink (file->path) != 0) { + g_warning ("GdmDisplayAccessFile: Unable to remove X11 authority database '%s': %s", + file->path, + g_strerror (errno)); + } + + /* still try to remove dir even if file remove failed, + may have already been removed by someone else */ + /* we own the parent directory too */ + auth_dir = g_path_get_dirname (file->path); + if (auth_dir != NULL) { + errno = 0; + if (g_rmdir (auth_dir) != 0) { + g_warning ("GdmDisplayAccessFile: Unable to remove X11 authority directory '%s': %s", + auth_dir, + g_strerror (errno)); + } + g_free (auth_dir); + } + + g_free (file->path); + file->path = NULL; + g_object_notify (G_OBJECT (file), "path"); + + fclose (file->fp); + file->fp = NULL; +} + +char * +gdm_display_access_file_get_path (GdmDisplayAccessFile *access_file) +{ + return g_strdup (access_file->path); +} -- cgit v1.2.3