1 files changed, 275 insertions, 0 deletions
diff --git a/ipc/kdbus/endpoint.c b/ipc/kdbus/endpoint.c
new file mode 100644
index 00000000000..174d274b113
--- /dev/null
+++ b/ipc/kdbus/endpoint.c
@@ -0,0 +1,275 @@
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@zonque.org>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@gmail.com>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@opendz.org>
+ *
+ * kdbus 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.
+ */
+
+#include <linux/fs.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/uio.h>
+
+#include "bus.h"
+#include "connection.h"
+#include "domain.h"
+#include "endpoint.h"
+#include "handle.h"
+#include "item.h"
+#include "message.h"
+#include "policy.h"
+
+static void kdbus_ep_free(struct kdbus_node *node)
+{
+	struct kdbus_ep *ep = container_of(node, struct kdbus_ep, node);
+
+	WARN_ON(!list_empty(&ep->conn_list));
+
+	kdbus_policy_db_clear(&ep->policy_db);
+	kdbus_bus_unref(ep->bus);
+	kdbus_user_unref(ep->user);
+	kfree(ep);
+}
+
+static void kdbus_ep_release(struct kdbus_node *node, bool was_active)
+{
+	struct kdbus_ep *ep = container_of(node, struct kdbus_ep, node);
+
+	/* disconnect all connections to this endpoint */
+	for (;;) {
+		struct kdbus_conn *conn;
+
+		mutex_lock(&ep->lock);
+		conn = list_first_entry_or_null(&ep->conn_list,
+						struct kdbus_conn,
+						ep_entry);
+		if (!conn) {
+			mutex_unlock(&ep->lock);
+			break;
+		}
+
+		/* take reference, release lock, disconnect without lock */
+		kdbus_conn_ref(conn);
+		mutex_unlock(&ep->lock);
+
+		kdbus_conn_disconnect(conn, false);
+		kdbus_conn_unref(conn);
+	}
+}
+
+/**
+ * kdbus_ep_new() - create a new endpoint
+ * @bus:		The bus this endpoint will be created for
+ * @name:		The name of the endpoint
+ * @access:		The access flags for this node (KDBUS_MAKE_ACCESS_*)
+ * @uid:		The uid of the node
+ * @gid:		The gid of the node
+ * @is_custom:		Whether this is a custom endpoint
+ *
+ * This function will create a new enpoint with the given
+ * name and properties for a given bus.
+ *
+ * Return: a new kdbus_ep on success, ERR_PTR on failure.
+ */
+struct kdbus_ep *kdbus_ep_new(struct kdbus_bus *bus, const char *name,
+			      unsigned int access, kuid_t uid, kgid_t gid,
+			      bool is_custom)
+{
+	struct kdbus_ep *e;
+	int ret;
+
+	/*
+	 * Validate only custom endpoints names, default endpoints
+	 * with a "bus" name are created when the bus is created
+	 */
+	if (is_custom) {
+		ret = kdbus_verify_uid_prefix(name, bus->domain->user_namespace,
+					      uid);
+		if (ret < 0)
+			return ERR_PTR(ret);
+	}
+
+	e = kzalloc(sizeof(*e), GFP_KERNEL);
+	if (!e)
+		return ERR_PTR(-ENOMEM);
+
+	kdbus_node_init(&e->node, KDBUS_NODE_ENDPOINT);
+
+	e->node.free_cb = kdbus_ep_free;
+	e->node.release_cb = kdbus_ep_release;
+	e->node.uid = uid;
+	e->node.gid = gid;
+	e->node.mode = S_IRUSR | S_IWUSR;
+	if (access & (KDBUS_MAKE_ACCESS_GROUP | KDBUS_MAKE_ACCESS_WORLD))
+		e->node.mode |= S_IRGRP | S_IWGRP;
+	if (access & KDBUS_MAKE_ACCESS_WORLD)
+		e->node.mode |= S_IROTH | S_IWOTH;
+
+	mutex_init(&e->lock);
+	INIT_LIST_HEAD(&e->conn_list);
+	kdbus_policy_db_init(&e->policy_db);
+	e->bus = kdbus_bus_ref(bus);
+
+	ret = kdbus_node_link(&e->node, &bus->node, name);
+	if (ret < 0)
+		goto exit_unref;
+
+	/*
+	 * Transactions on custom endpoints are never accounted on the global
+	 * user limits. Instead, for each custom endpoint, we create a custom,
+	 * unique user, which all transactions are accounted on. Regardless of
+	 * the user using that endpoint, it is always accounted on the same
+	 * user-object. This budget is not shared with ordinary users on
+	 * non-custom endpoints.
+	 */
+	if (is_custom) {
+		e->user = kdbus_user_lookup(bus->domain, INVALID_UID);
+		if (IS_ERR(e->user)) {
+			ret = PTR_ERR(e->user);
+			e->user = NULL;
+			goto exit_unref;
+		}
+	}
+
+	return e;
+
+exit_unref:
+	kdbus_node_deactivate(&e->node);
+	kdbus_node_unref(&e->node);
+	return ERR_PTR(ret);
+}
+
+/**
+ * kdbus_ep_ref() - increase the reference counter of a kdbus_ep
+ * @ep:			The endpoint to reference
+ *
+ * Every user of an endpoint, except for its creator, must add a reference to
+ * the kdbus_ep instance using this function.
+ *
+ * Return: the ep itself
+ */
+struct kdbus_ep *kdbus_ep_ref(struct kdbus_ep *ep)
+{
+	if (ep)
+		kdbus_node_ref(&ep->node);
+	return ep;
+}
+
+/**
+ * kdbus_ep_unref() - decrease the reference counter of a kdbus_ep
+ * @ep:		The ep to unref
+ *
+ * Release a reference. If the reference count drops to 0, the ep will be
+ * freed.
+ *
+ * Return: NULL
+ */
+struct kdbus_ep *kdbus_ep_unref(struct kdbus_ep *ep)
+{
+	if (ep)
+		kdbus_node_unref(&ep->node);
+	return NULL;
+}
+
+/**
+ * kdbus_cmd_ep_make() - handle KDBUS_CMD_ENDPOINT_MAKE
+ * @bus:		bus to operate on
+ * @argp:		command payload
+ *
+ * Return: Newly created endpoint on success, ERR_PTR on failure.
+ */
+struct kdbus_ep *kdbus_cmd_ep_make(struct kdbus_bus *bus, void __user *argp)
+{
+	const char *item_make_name;
+	struct kdbus_ep *ep = NULL;
+	struct kdbus_cmd *cmd;
+	int ret;
+
+	struct kdbus_arg argv[] = {
+		{ .type = KDBUS_ITEM_NEGOTIATE },
+		{ .type = KDBUS_ITEM_MAKE_NAME, .mandatory = true },
+	};
+	struct kdbus_args args = {
+		.allowed_flags = KDBUS_FLAG_NEGOTIATE |
+				 KDBUS_MAKE_ACCESS_GROUP |
+				 KDBUS_MAKE_ACCESS_WORLD,
+		.argv = argv,
+		.argc = ARRAY_SIZE(argv),
+	};
+
+	ret = kdbus_args_parse(&args, argp, &cmd);
+	if (ret < 0)
+		return ERR_PTR(ret);
+	if (ret > 0)
+		return NULL;
+
+	item_make_name = argv[1].item->str;
+
+	ep = kdbus_ep_new(bus, item_make_name, cmd->flags,
+			  current_euid(), current_egid(), true);
+	if (IS_ERR(ep)) {
+		ret = PTR_ERR(ep);
+		ep = NULL;
+		goto exit;
+	}
+
+	if (!kdbus_node_activate(&ep->node)) {
+		ret = -ESHUTDOWN;
+		goto exit;
+	}
+
+exit:
+	ret = kdbus_args_clear(&args, ret);
+	if (ret < 0) {
+		if (ep) {
+			kdbus_node_deactivate(&ep->node);
+			kdbus_ep_unref(ep);
+		}
+		return ERR_PTR(ret);
+	}
+	return ep;
+}
+
+/**
+ * kdbus_cmd_ep_update() - handle KDBUS_CMD_ENDPOINT_UPDATE
+ * @ep:			endpoint to operate on
+ * @argp:		command payload
+ *
+ * Return: Newly created endpoint on success, ERR_PTR on failure.
+ */
+int kdbus_cmd_ep_update(struct kdbus_ep *ep, void __user *argp)
+{
+	struct kdbus_cmd *cmd;
+	int ret;
+
+	struct kdbus_arg argv[] = {
+		{ .type = KDBUS_ITEM_NEGOTIATE },
+		{ .type = KDBUS_ITEM_NAME, .multiple = true },
+		{ .type = KDBUS_ITEM_POLICY_ACCESS, .multiple = true },
+	};
+	struct kdbus_args args = {
+		.allowed_flags = KDBUS_FLAG_NEGOTIATE,
+		.argv = argv,
+		.argc = ARRAY_SIZE(argv),
+	};
+
+	ret = kdbus_args_parse(&args, argp, &cmd);
+	if (ret != 0)
+		return ret;
+
+	ret = kdbus_policy_set(&ep->policy_db, args.items, args.items_size,
+			       0, true, ep);
+	return kdbus_args_clear(&args, ret);
+}