From 0b0e6bc987da4fd88a7854ebb12bde705e92c428 Mon Sep 17 00:00:00 2001 From: Perberos Date: Thu, 1 Dec 2011 21:51:44 -0300 Subject: moving from https://github.com/perberos/mate-desktop-environment --- .../mate-display-properties-install-systemwide.c | 272 +++++++++++++++++++++ 1 file changed, 272 insertions(+) create mode 100644 capplets/display/mate-display-properties-install-systemwide.c (limited to 'capplets/display/mate-display-properties-install-systemwide.c') diff --git a/capplets/display/mate-display-properties-install-systemwide.c b/capplets/display/mate-display-properties-install-systemwide.c new file mode 100644 index 00000000..2d074eb8 --- /dev/null +++ b/capplets/display/mate-display-properties-install-systemwide.c @@ -0,0 +1,272 @@ +/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- + * + * mate-display-properties-install-systemwide - Install a RANDR profile for the whole system + * + * Copyright (C) 2010 Novell, Inc. + * + * Authors: Federico Mena Quintero + * + * Licensed under the GNU General Public License Version 2 + * + * 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 of the License, 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 + +#define SYSTEM_RANDR_PATH "/etc/mate-settings-daemon/xrandr" + +static void +usage (const char *program_name) +{ + g_print (_("Usage: %s SOURCE_FILE DEST_NAME\n" + "\n" + "This program installs a RANDR profile for multi-monitor setups into\n" + "a systemwide location. The resulting profile will get used when\n" + "the RANDR plug-in gets run in mate-settings-daemon.\n" + "\n" + "SOURCE_FILE - a full pathname, typically /home/username/.config/monitors.xml\n" + "\n" + "DEST_NAME - relative name for the installed file. This will get put in\n" + " the systemwide directory for RANDR configurations,\n" + " so the result will typically be %s/DEST_NAME\n"), + program_name, + SYSTEM_RANDR_PATH); +} + +static gboolean +is_basename (const char *filename) +{ + if (*filename == '\0') + return FALSE; /* no empty strings, please */ + + for (; *filename; filename++) + if (G_IS_DIR_SEPARATOR (*filename)) + return FALSE; + + return TRUE; +} + +static gboolean +copy_file (int source_fd, int dest_fd) +{ + char buf[1024]; + int num_read; + int num_written; + + while (TRUE) { + char *p; + + num_read = read (source_fd, buf, sizeof (buf)); + if (num_read == 0) + break; + + if (num_read == -1) { + if (errno == EINTR) + continue; + else + return FALSE; + } + + p = buf; + while (num_read > 0) { + num_written = write (dest_fd, p, num_read); + if (num_written == -1) { + if (errno == EINTR) + continue; + else + return FALSE; + } + + num_read -= num_written; + p += num_written; + } + } + + return TRUE; +} + +/* This is essentially a "please copy a file to a privileged location" program. + * We try to be paranoid in the following ways: + * + * - We copy only regular files, owned by the user who called pkexec(1), to + * avoid attacks like "copy a file that I'm not allowed to read into a + * world-readable location". + * + * - We copy only to a well-known directory. + * + * - We try to avoid race conditions. We only fstat() files that we have open + * to avoid files moving under our feet. We only create files in directories + * that we have open. + * + * - We replace the destination file atomically. + */ + +int +main (int argc, char **argv) +{ + uid_t uid, euid; + const char *source_filename; + const char *dest_name; + const char *pkexec_uid_str; + int pkexec_uid; + struct stat statbuf; + int err; + int source_fd; + int dest_fd; + char template[100]; + + setlocale (LC_ALL, ""); + bindtextdomain (GETTEXT_PACKAGE, MATELOCALEDIR); + bind_textdomain_codeset (GETTEXT_PACKAGE, "UTF-8"); + textdomain (GETTEXT_PACKAGE); + + /* We only run as root */ + uid = getuid (); + euid = geteuid (); + if (uid != 0 || euid != 0) { + /* Translators: only able to install RANDR profiles as root */ + g_print ("%s\n", _("This program can only be used by the root user")); + return EXIT_FAILURE; + } + + /* Usage: gsd-xrandr-install-systemwide SOURCE_FILE DEST_NAME */ + + if (argc != 3) { + usage (argv[0]); + return EXIT_FAILURE; + } + + source_filename = argv[1]; + dest_name = argv[2]; + + /* Absolute source filenames only, please */ + + if (!g_path_is_absolute (source_filename)) { + g_print ("%s\n", _("The source filename must be absolute")); + return EXIT_FAILURE; + } + + /* We only copy regular files */ + + source_fd = open (source_filename, O_RDONLY); + if (source_fd == -1) { + err = errno; + + /* Translators: first %s is a filename; second %s is an error message */ + g_print (_("Could not open %s: %s\n"), + source_filename, + g_strerror (err)); + return EXIT_FAILURE; + } + + if (fstat (source_fd, &statbuf) != 0) { + err = errno; + /* Translators: first %s is a filename; second %s is an error message */ + g_print (_("Could not get information for %s: %s\n"), + source_filename, + g_strerror (err)); + return EXIT_FAILURE; + } + + if (!S_ISREG (statbuf.st_mode)) { + g_print (_("%s must be a regular file\n"), + source_filename); + return EXIT_FAILURE; + } + + /* We only copy files that are really owned by the calling user */ + + pkexec_uid_str = g_getenv ("PKEXEC_UID"); + if (pkexec_uid_str == NULL) { + g_print ("%s\n", _("This program must only be run through pkexec(1)")); + return EXIT_FAILURE; + } + + if (sscanf (pkexec_uid_str, "%d", &pkexec_uid) != 1) { + g_print ("%s\n", _("PKEXEC_UID must be set to an integer value")); + return EXIT_FAILURE; + } + + if (statbuf.st_uid != pkexec_uid) { + /* Translators: we are complaining that a file must be really owned by the user who called this program */ + g_print (_("%s must be owned by you\n"), source_filename); + return EXIT_FAILURE; + } + + /* We only accept basenames for the destination */ + + if (!is_basename (dest_name)) { + /* Translators: here we are saying that a plain filename must look like "filename", not like "some_dir/filename" */ + g_print (_("%s must not have any directory components\n"), + dest_name); + return EXIT_FAILURE; + } + + /* Chdir to the destination directory to keep it open... */ + + if (chdir (SYSTEM_RANDR_PATH) != 0) { + g_print (_("%s must be a directory\n"), SYSTEM_RANDR_PATH); + return EXIT_FAILURE; + } + + /* ... and open our temporary destination file right there */ + + strcpy (template, "gsd-XXXXXX"); + dest_fd = g_mkstemp_full (template, O_WRONLY, 0644); + if (dest_fd == -1) { + err = errno; + /* Translators: the first %s/%s is a directory/filename; the last %s is an error message */ + g_print (_("Could not open %s/%s: %s\n"), + SYSTEM_RANDR_PATH, + template, + g_strerror (err)); + return EXIT_FAILURE; + } + + /* Do the copy */ + + if (!copy_file (source_fd, dest_fd)) { + /* If something went wrong, remove the destination file to avoid leaving trash around */ + unlink (template); + return EXIT_FAILURE; + } + + /* Rename to the final filename */ + + if (rename (template, dest_name) != 0) { + err = errno; + unlink (template); + g_print (_("Could not rename %s to %s: %s\n"), + template, + dest_name, + g_strerror (err)); + return EXIT_FAILURE; + } + + /* Whew! We'll leave the final closing of the files to the almighty kernel. */ + + return EXIT_SUCCESS; +} -- cgit v1.2.1