udev-acl: move from udev-extras

The build of extras with larger external dependencies is wrapped in:
      --enable-extras

1 files changed, 334 insertions, 0 deletions

diff --git a/extras/udev-acl/udev-acl.c b/extras/udev-acl/udev-acl.c
new file mode 100644
index 0000000000..ec95025eb3
--- /dev/null
+++ b/extras/udev-acl/udev-acl.c
@@ -0,0 +1,334 @@
+/*
+ * Copyright (C) 2009 Kay Sievers <kay.sievers@vrfy.org>
+ *
+ * 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:
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <inttypes.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <getopt.h>
+#include <sys/stat.h>
+#include <glib.h>
+#include <acl/libacl.h>
+#include <libudev.h>
+
+static int debug;
+
+static int set_facl(const char* filename, uid_t uid, int add)
+{
+	int get;
+	acl_t acl;
+	acl_entry_t entry = NULL;
+	acl_entry_t e;
+	acl_permset_t permset;
+	int ret;
+
+	/* read current record */
+	acl = acl_get_file(filename, ACL_TYPE_ACCESS);
+	if (!acl)
+		return -1;
+
+	/* locate ACL_USER entry for uid */
+	get = acl_get_entry(acl, ACL_FIRST_ENTRY, &e);
+	while (get == 1) {
+		acl_tag_t t;
+
+		acl_get_tag_type(e, &t);
+		if (t == ACL_USER) {
+			uid_t *u;
+
+			u = (uid_t*)acl_get_qualifier(e);
+			if (u == NULL) {
+				ret = -1;
+				goto out;
+			}
+			if (*u == uid) {
+				entry = e;
+				acl_free(u);
+				break;
+			}
+			acl_free(u);
+		}
+
+		get = acl_get_entry(acl, ACL_NEXT_ENTRY, &e);
+	}
+
+	/* remove ACL_USER entry for uid */
+	if (!add) {
+		if (entry == NULL) {
+			ret = 0;
+			goto out;
+		}
+		acl_delete_entry(acl, entry);
+		goto update;
+	}
+
+	/* create ACL_USER entry for uid */
+	if (entry == NULL) {
+		ret = acl_create_entry(&acl, &entry);
+		if (ret != 0)
+			goto out;
+		acl_set_tag_type(entry, ACL_USER);
+		acl_set_qualifier(entry, &uid);
+	}
+
+	/* add permissions for uid */
+	acl_get_permset(entry, &permset);
+	acl_add_perm(permset, ACL_READ|ACL_WRITE);
+update:
+	/* update record */
+	if (debug)
+		printf("%c%u %s\n", add ? '+' : '-', uid, filename);
+	acl_calc_mask(&acl);
+	ret = acl_set_file(filename, ACL_TYPE_ACCESS, acl);
+	if (ret != 0)
+		goto out;
+out:
+	acl_free(acl);
+	return ret;
+}
+
+/* check if a given uid is listed */
+static int uid_in_list(GSList *list, uid_t uid)
+{
+	GSList *l;
+
+	for (l = list; l != NULL; l = g_slist_next(l))
+		if (uid == GPOINTER_TO_UINT(l->data))
+			return 1;
+	return 0;
+}
+
+/* return list of current uids of local active sessions */
+static GSList *uids_with_local_active_session(const char *own_id)
+{
+	GSList *list = NULL;
+	GKeyFile *keyfile;
+
+	keyfile = g_key_file_new();
+	if (g_key_file_load_from_file(keyfile, "/var/run/ConsoleKit/database", 0, NULL)) {
+		gchar **groups;
+
+		groups = g_key_file_get_groups(keyfile, NULL);
+		if (groups != NULL) {
+			int i;
+
+			for (i = 0; groups[i] != NULL; i++) {
+				uid_t u;
+
+				if (!g_str_has_prefix(groups[i], "Session "))
+					continue;
+				if (own_id != NULL &&g_str_has_suffix(groups[i], own_id))
+					continue;
+				if (!g_key_file_get_boolean(keyfile, groups[i], "is_local", NULL))
+					continue;
+				if (!g_key_file_get_boolean(keyfile, groups[i], "is_active", NULL))
+					continue;
+				u = g_key_file_get_integer(keyfile, groups[i], "uid", NULL);
+				if (u > 0 && !uid_in_list(list, u))
+					list = g_slist_prepend(list, GUINT_TO_POINTER(u));
+			}
+			g_strfreev(groups);
+		}
+	}
+	g_key_file_free(keyfile);
+
+	return list;
+}
+
+/* ConsoleKit calls us with special variables */
+static int consolekit_called(const char *action, uid_t *uid, const char **own_session, int *add)
+{
+	int a;
+	uid_t u;
+	const char *s;
+	const char *session;
+
+	if (strcmp(action, "session_active_changed") != 0)
+		return -1;
+
+	s = getenv("CK_SESSION_IS_LOCAL");
+	if (s == NULL)
+		return -1;
+	if (strcmp(s, "true") != 0)
+		return 0;
+
+	s = getenv("CK_SESSION_IS_ACTIVE");
+	if (s == NULL)
+		return -1;
+	if (strcmp(s, "true") == 0)
+		a = 1;
+	else
+		a = 0;
+
+	session = getenv("CK_SESSION_ID");
+	if (session == NULL)
+		return -1;
+
+	s = getenv("CK_SESSION_USER_UID");
+	if (s == NULL)
+		return -1;
+	u = strtoul(s, NULL, 10);
+	if (u == 0)
+		return 0;
+
+	*own_session = session;
+	*uid = u;
+	*add = a;
+	return 0;
+}
+
+/* add or remove a ACL for a given uid from all matching devices */
+static void apply_acl_to_devices(uid_t uid, int add)
+{
+	struct udev *udev;
+	struct udev_enumerate *enumerate;
+	struct udev_list_entry *list_entry;
+
+	/* iterate over all devices tagged with ACL_SET */
+	udev = udev_new();
+	enumerate = udev_enumerate_new(udev);
+	udev_enumerate_add_match_property(enumerate, "ACL_MANAGE", "*");
+	udev_enumerate_scan_devices(enumerate);
+	udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(enumerate)) {
+		struct udev_device *device;
+		const char *node;
+
+		device = udev_device_new_from_syspath(udev_enumerate_get_udev(enumerate),
+						      udev_list_entry_get_name(list_entry));
+		if (device == NULL)
+			continue;
+		node = udev_device_get_devnode(device);
+		if (node == NULL)
+			continue;
+		set_facl(node, uid, add);
+		udev_device_unref(device);
+	}
+	udev_enumerate_unref(enumerate);
+	udev_unref(udev);
+}
+
+int main (int argc, char* argv[])
+{
+	static const struct option options[] = {
+		{ "action", required_argument, NULL, 'a' },
+		{ "device", required_argument, NULL, 'D' },
+		{ "user", required_argument, NULL, 'u' },
+		{ "debug", no_argument, NULL, 'd' },
+		{ "help", no_argument, NULL, 'h' },
+		{}
+	};
+	int add = -1;
+	const char *device = NULL;
+	uid_t uid = 0;
+	const char* own_session = NULL;
+	int rc = 0;
+
+	/* valgrind is more important to us than a slice allocator */
+	g_slice_set_config (G_SLICE_CONFIG_ALWAYS_MALLOC, 1);
+
+	while (1) {
+		int option;
+
+		option = getopt_long(argc, argv, "+a:D:u:dh", options, NULL);
+		if (option == -1)
+			break;
+
+		switch (option) {
+		case 'a':
+			if (strcmp(optarg, "add") == 0 || strcmp(optarg, "change") == 0)
+				add = 1;
+			else if (strcmp(optarg, "remove") == 0)
+				add = 0;
+			else
+				goto out;
+			break;
+		case 'D':
+			device = optarg;
+			break;
+		case 'u':
+			uid = strtoul(optarg, NULL, 10);
+			break;
+		case 'd':
+			debug = 1;
+			break;
+		case 'h':
+			printf("Usage: udev-acl --action=ACTION [--device=DEVICEFILE] [--user=UID]\n\n");
+		default:
+			goto out;
+		}
+	}
+
+	if (add < 0 && device == NULL && uid == 0)
+		consolekit_called(argv[optind], &uid, &own_session, &add);
+
+	if (add < 0) {
+		fprintf(stderr, "missing action\n\n");
+		rc = 2;
+		goto out;
+	}
+
+	if (device != NULL && uid != 0) {
+		fprintf(stderr, "only one option, --device=DEVICEFILE or --user=UID expected\n\n");
+		rc = 3;
+		goto out;
+	}
+
+	if (uid != 0) {
+		if (add) {
+			/* Add ACL for given uid to all matching devices. */
+			apply_acl_to_devices(uid, 1);
+		} else {
+			/*
+			 * Remove ACL for given uid from all matching devices
+			 * when there is currently no local active session.
+			 */
+			GSList *list;
+
+			list = uids_with_local_active_session(own_session);
+			if (!uid_in_list(list, uid))
+				apply_acl_to_devices(uid, 0);
+			g_slist_free(list);
+		}
+	} else if (device != NULL) {
+		/*
+		 * Add ACLs for all current session uids to a given device.
+		 *
+		 * Or remove ACLs for uids which do not have any current local
+		 * active session. Remove is not really interesting, because in
+		 * most cases the device node is removed anyway.
+		 */
+		GSList *list;
+		GSList *l;
+
+		list = uids_with_local_active_session(NULL);
+		for (l = list; l != NULL; l = g_slist_next(l)) {
+			uid_t u;
+
+			u = GPOINTER_TO_UINT(l->data);
+			if (add || !uid_in_list(list, u))
+				set_facl(device, u, add);
+		}
+		g_slist_free(list);
+	} else {
+		fprintf(stderr, "--device=DEVICEFILE or --user=UID expected\n\n");
+		rc = 3;
+	}
+out:
+	return rc;
+}