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-rw-r--r--ipc/kdbus/domain.c296
1 files changed, 296 insertions, 0 deletions
diff --git a/ipc/kdbus/domain.c b/ipc/kdbus/domain.c
new file mode 100644
index 000000000..ac9f760c1
--- /dev/null
+++ b/ipc/kdbus/domain.c
@@ -0,0 +1,296 @@
+/*
+ * 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 "bus.h"
+#include "domain.h"
+#include "handle.h"
+#include "item.h"
+#include "limits.h"
+#include "util.h"
+
+static void kdbus_domain_control_free(struct kdbus_node *node)
+{
+ kfree(node);
+}
+
+static struct kdbus_node *kdbus_domain_control_new(struct kdbus_domain *domain,
+ unsigned int access)
+{
+ struct kdbus_node *node;
+ int ret;
+
+ node = kzalloc(sizeof(*node), GFP_KERNEL);
+ if (!node)
+ return ERR_PTR(-ENOMEM);
+
+ kdbus_node_init(node, KDBUS_NODE_CONTROL);
+
+ node->free_cb = kdbus_domain_control_free;
+ node->mode = domain->node.mode;
+ node->mode = S_IRUSR | S_IWUSR;
+ if (access & (KDBUS_MAKE_ACCESS_GROUP | KDBUS_MAKE_ACCESS_WORLD))
+ node->mode |= S_IRGRP | S_IWGRP;
+ if (access & KDBUS_MAKE_ACCESS_WORLD)
+ node->mode |= S_IROTH | S_IWOTH;
+
+ ret = kdbus_node_link(node, &domain->node, "control");
+ if (ret < 0)
+ goto exit_free;
+
+ return node;
+
+exit_free:
+ kdbus_node_deactivate(node);
+ kdbus_node_unref(node);
+ return ERR_PTR(ret);
+}
+
+static void kdbus_domain_free(struct kdbus_node *node)
+{
+ struct kdbus_domain *domain =
+ container_of(node, struct kdbus_domain, node);
+
+ put_user_ns(domain->user_namespace);
+ ida_destroy(&domain->user_ida);
+ idr_destroy(&domain->user_idr);
+ kfree(domain);
+}
+
+/**
+ * kdbus_domain_new() - create a new domain
+ * @access: The access mode for this node (KDBUS_MAKE_ACCESS_*)
+ *
+ * Return: a new kdbus_domain on success, ERR_PTR on failure
+ */
+struct kdbus_domain *kdbus_domain_new(unsigned int access)
+{
+ struct kdbus_domain *d;
+ int ret;
+
+ d = kzalloc(sizeof(*d), GFP_KERNEL);
+ if (!d)
+ return ERR_PTR(-ENOMEM);
+
+ kdbus_node_init(&d->node, KDBUS_NODE_DOMAIN);
+
+ d->node.free_cb = kdbus_domain_free;
+ d->node.mode = S_IRUSR | S_IXUSR;
+ if (access & (KDBUS_MAKE_ACCESS_GROUP | KDBUS_MAKE_ACCESS_WORLD))
+ d->node.mode |= S_IRGRP | S_IXGRP;
+ if (access & KDBUS_MAKE_ACCESS_WORLD)
+ d->node.mode |= S_IROTH | S_IXOTH;
+
+ mutex_init(&d->lock);
+ idr_init(&d->user_idr);
+ ida_init(&d->user_ida);
+
+ /* Pin user namespace so we can guarantee domain-unique bus * names. */
+ d->user_namespace = get_user_ns(current_user_ns());
+
+ ret = kdbus_node_link(&d->node, NULL, NULL);
+ if (ret < 0)
+ goto exit_unref;
+
+ return d;
+
+exit_unref:
+ kdbus_node_deactivate(&d->node);
+ kdbus_node_unref(&d->node);
+ return ERR_PTR(ret);
+}
+
+/**
+ * kdbus_domain_ref() - take a domain reference
+ * @domain: Domain
+ *
+ * Return: the domain itself
+ */
+struct kdbus_domain *kdbus_domain_ref(struct kdbus_domain *domain)
+{
+ if (domain)
+ kdbus_node_ref(&domain->node);
+ return domain;
+}
+
+/**
+ * kdbus_domain_unref() - drop a domain reference
+ * @domain: Domain
+ *
+ * When the last reference is dropped, the domain internal structure
+ * is freed.
+ *
+ * Return: NULL
+ */
+struct kdbus_domain *kdbus_domain_unref(struct kdbus_domain *domain)
+{
+ if (domain)
+ kdbus_node_unref(&domain->node);
+ return NULL;
+}
+
+/**
+ * kdbus_domain_populate() - populate static domain nodes
+ * @domain: domain to populate
+ * @access: KDBUS_MAKE_ACCESS_* access restrictions for new nodes
+ *
+ * Allocate and activate static sub-nodes of the given domain. This will fail if
+ * you call it on a non-active node or if the domain was already populated.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kdbus_domain_populate(struct kdbus_domain *domain, unsigned int access)
+{
+ struct kdbus_node *control;
+
+ /*
+ * Create a control-node for this domain. We drop our own reference
+ * immediately, effectively causing the node to be deactivated and
+ * released when the parent domain is.
+ */
+ control = kdbus_domain_control_new(domain, access);
+ if (IS_ERR(control))
+ return PTR_ERR(control);
+
+ kdbus_node_activate(control);
+ kdbus_node_unref(control);
+ return 0;
+}
+
+/**
+ * kdbus_user_lookup() - lookup a kdbus_user object
+ * @domain: domain of the user
+ * @uid: uid of the user; INVALID_UID for an anon user
+ *
+ * Lookup the kdbus user accounting object for the given domain. If INVALID_UID
+ * is passed, a new anonymous user is created which is private to the caller.
+ *
+ * Return: The user object is returned, ERR_PTR on failure.
+ */
+struct kdbus_user *kdbus_user_lookup(struct kdbus_domain *domain, kuid_t uid)
+{
+ struct kdbus_user *u = NULL, *old = NULL;
+ int ret;
+
+ mutex_lock(&domain->lock);
+
+ if (uid_valid(uid)) {
+ old = idr_find(&domain->user_idr, __kuid_val(uid));
+ /*
+ * If the object is about to be destroyed, ignore it and
+ * replace the slot in the IDR later on.
+ */
+ if (old && kref_get_unless_zero(&old->kref)) {
+ mutex_unlock(&domain->lock);
+ return old;
+ }
+ }
+
+ u = kzalloc(sizeof(*u), GFP_KERNEL);
+ if (!u) {
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ kref_init(&u->kref);
+ u->domain = kdbus_domain_ref(domain);
+ u->uid = uid;
+ atomic_set(&u->buses, 0);
+ atomic_set(&u->connections, 0);
+
+ if (uid_valid(uid)) {
+ if (old) {
+ idr_replace(&domain->user_idr, u, __kuid_val(uid));
+ old->uid = INVALID_UID; /* mark old as removed */
+ } else {
+ ret = idr_alloc(&domain->user_idr, u, __kuid_val(uid),
+ __kuid_val(uid) + 1, GFP_KERNEL);
+ if (ret < 0)
+ goto exit;
+ }
+ }
+
+ /*
+ * Allocate the smallest possible index for this user; used
+ * in arrays for accounting user quota in receiver queues.
+ */
+ ret = ida_simple_get(&domain->user_ida, 1, 0, GFP_KERNEL);
+ if (ret < 0)
+ goto exit;
+
+ u->id = ret;
+ mutex_unlock(&domain->lock);
+ return u;
+
+exit:
+ if (u) {
+ if (uid_valid(u->uid))
+ idr_remove(&domain->user_idr, __kuid_val(u->uid));
+ kdbus_domain_unref(u->domain);
+ kfree(u);
+ }
+ mutex_unlock(&domain->lock);
+ return ERR_PTR(ret);
+}
+
+static void __kdbus_user_free(struct kref *kref)
+{
+ struct kdbus_user *user = container_of(kref, struct kdbus_user, kref);
+
+ WARN_ON(atomic_read(&user->buses) > 0);
+ WARN_ON(atomic_read(&user->connections) > 0);
+
+ mutex_lock(&user->domain->lock);
+ ida_simple_remove(&user->domain->user_ida, user->id);
+ if (uid_valid(user->uid))
+ idr_remove(&user->domain->user_idr, __kuid_val(user->uid));
+ mutex_unlock(&user->domain->lock);
+
+ kdbus_domain_unref(user->domain);
+ kfree(user);
+}
+
+/**
+ * kdbus_user_ref() - take a user reference
+ * @u: User
+ *
+ * Return: @u is returned
+ */
+struct kdbus_user *kdbus_user_ref(struct kdbus_user *u)
+{
+ if (u)
+ kref_get(&u->kref);
+ return u;
+}
+
+/**
+ * kdbus_user_unref() - drop a user reference
+ * @u: User
+ *
+ * Return: NULL
+ */
+struct kdbus_user *kdbus_user_unref(struct kdbus_user *u)
+{
+ if (u)
+ kref_put(&u->kref, __kdbus_user_free);
+ return NULL;
+}