From: Daniel Mack <daniel@xxxxxxxxxx>
This patch adds the name registry implementation.
Each bus instantiates a name registry to resolve well-known names
into unique connection IDs for message delivery. The registry will
be queried when a message is sent with kdbus_msg.dst_id set to
KDBUS_DST_ID_NAME, or when a registry dump is requested.
It's important to have this registry implemented in the kernel to
implement lookups and take-overs in a race-free way.
Signed-off-by: Daniel Mack <daniel@xxxxxxxxxx>
Signed-off-by: David Herrmann <dh.herrmann@xxxxxxxxx>
Signed-off-by: Djalal Harouni <tixxdz@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
ipc/kdbus/names.c | 772 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
ipc/kdbus/names.h | 74 ++++++
2 files changed, 846 insertions(+)
create mode 100644 ipc/kdbus/names.c
create mode 100644 ipc/kdbus/names.h
diff --git a/ipc/kdbus/names.c b/ipc/kdbus/names.c
new file mode 100644
index 000000000000..657008e1bb37
--- /dev/null
+++ b/ipc/kdbus/names.c
@@ -0,0 +1,772 @@
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@xxxxxxxxxx>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@xxxxxxxxx>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@xxxxxxxxxx>
+ *
+ * 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/ctype.h>
+#include <linux/fs.h>
+#include <linux/hash.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/rwsem.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/uio.h>
+
+#include "bus.h"
+#include "connection.h"
+#include "endpoint.h"
+#include "handle.h"
+#include "item.h"
+#include "names.h"
+#include "notify.h"
+#include "policy.h"
+
+struct kdbus_name_pending {
+ u64 flags;
+ struct kdbus_conn *conn;
+ struct kdbus_name_entry *name;
+ struct list_head conn_entry;
+ struct list_head name_entry;
+};
+
+static int kdbus_name_pending_new(struct kdbus_name_entry *e,
+ struct kdbus_conn *conn, u64 flags)
+{
+ struct kdbus_name_pending *p;
+
+ kdbus_conn_assert_active(conn);
+
+ p = kmalloc(sizeof(*p), GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+
+ p->flags = flags;
+ p->conn = conn;
+ p->name = e;
+ list_add_tail(&p->conn_entry, &conn->names_queue_list);
+ list_add_tail(&p->name_entry, &e->queue);
+
+ return 0;
+}
+
+static void kdbus_name_pending_free(struct kdbus_name_pending *p)
+{
+ if (!p)
+ return;
+
+ list_del(&p->name_entry);
+ list_del(&p->conn_entry);
+ kfree(p);
+}
+
+static struct kdbus_name_entry *
+kdbus_name_entry_new(struct kdbus_name_registry *r, u32 hash, const char *name)
+{
+ struct kdbus_name_entry *e;
+ size_t namelen;
+
+ namelen = strlen(name);
+
+ e = kmalloc(sizeof(*e) + namelen + 1, GFP_KERNEL);
+ if (!e)
+ return ERR_PTR(-ENOMEM);
+
+ e->name_id = ++r->name_seq_last;
+ e->flags = 0;
+ e->conn = NULL;
+ e->activator = NULL;
+ INIT_LIST_HEAD(&e->queue);
+ INIT_LIST_HEAD(&e->conn_entry);
+ hash_add(r->entries_hash, &e->hentry, hash);
+ memcpy(e->name, name, namelen + 1);
+
+ return e;
+}
+
+static void kdbus_name_entry_free(struct kdbus_name_entry *e)
+{
+ if (!e)
+ return;
+
+ WARN_ON(!list_empty(&e->conn_entry));
+ WARN_ON(!list_empty(&e->queue));
+ WARN_ON(e->activator);
+ WARN_ON(e->conn);
+
+ hash_del(&e->hentry);
+ kfree(e);
+}
+
+static void kdbus_name_entry_set_owner(struct kdbus_name_entry *e,
+ struct kdbus_conn *conn, u64 flags)
+{
+ WARN_ON(e->conn);
+
+ e->conn = kdbus_conn_ref(conn);
+ e->flags = flags;
+ atomic_inc(&conn->name_count);
+ list_add_tail(&e->conn_entry, &e->conn->names_list);
+}
+
+static void kdbus_name_entry_remove_owner(struct kdbus_name_entry *e)
+{
+ WARN_ON(!e->conn);
+
+ list_del_init(&e->conn_entry);
+ atomic_dec(&e->conn->name_count);
+ e->flags = 0;
+ e->conn = kdbus_conn_unref(e->conn);
+}
+
+static void kdbus_name_entry_replace_owner(struct kdbus_name_entry *e,
+ struct kdbus_conn *conn, u64 flags)
+{
+ if (WARN_ON(!e->conn) || WARN_ON(conn == e->conn))
+ return;
+
+ kdbus_notify_name_change(conn->ep->bus, KDBUS_ITEM_NAME_CHANGE,
+ e->conn->id, conn->id,
+ e->flags, flags, e->name);
+ kdbus_name_entry_remove_owner(e);
+ kdbus_name_entry_set_owner(e, conn, flags);
+}
+
+/**
+ * kdbus_name_is_valid() - check if a name is valid
+ * @p: The name to check
+ * @allow_wildcard: Whether or not to allow a wildcard name
+ *
+ * A name is valid if all of the following criterias are met:
+ *
+ * - The name has two or more elements separated by a period ('.') character.
+ * - All elements must contain at least one character.
+ * - Each element must only contain the ASCII characters "[A-Z][a-z][0-9]_-"
+ * and must not begin with a digit.
+ * - The name must not exceed KDBUS_NAME_MAX_LEN.
+ * - If @allow_wildcard is true, the name may end on '.*'
+ */
+bool kdbus_name_is_valid(const char *p, bool allow_wildcard)
+{
+ bool dot, found_dot = false;
+ const char *q;
+
+ for (dot = true, q = p; *q; q++) {
+ if (*q == '.') {
+ if (dot)
+ return false;
+
+ found_dot = true;
+ dot = true;
+ } else {
+ bool good;
+
+ good = isalpha(*q) || (!dot && isdigit(*q)) ||
+ *q == '_' || *q == '-' ||
+ (allow_wildcard && dot &&
+ *q == '*' && *(q + 1) == '\0');
+
+ if (!good)
+ return false;
+
+ dot = false;
+ }
+ }
+
+ if (q - p > KDBUS_NAME_MAX_LEN)
+ return false;
+
+ if (dot)
+ return false;
+
+ if (!found_dot)
+ return false;
+
+ return true;
+}
+
+/**
+ * kdbus_name_registry_new() - create a new name registry
+ *
+ * Return: a new kdbus_name_registry on success, ERR_PTR on failure.
+ */
+struct kdbus_name_registry *kdbus_name_registry_new(void)
+{
+ struct kdbus_name_registry *r;
+
+ r = kmalloc(sizeof(*r), GFP_KERNEL);
+ if (!r)
+ return ERR_PTR(-ENOMEM);
+
+ hash_init(r->entries_hash);
+ init_rwsem(&r->rwlock);
+ r->name_seq_last = 0;
+
+ return r;
+}
+
+/**
+ * kdbus_name_registry_free() - drop a name reg's reference
+ * @reg: The name registry, may be %NULL
+ *
+ * Cleanup the name registry's internal structures.
+ */
+void kdbus_name_registry_free(struct kdbus_name_registry *reg)
+{
+ if (!reg)
+ return;
+
+ WARN_ON(!hash_empty(reg->entries_hash));
+ kfree(reg);
+}
+
+static struct kdbus_name_entry *
+kdbus_name_find(struct kdbus_name_registry *reg, u32 hash, const char *name)
+{
+ struct kdbus_name_entry *e;
+
+ lockdep_assert_held(®->rwlock);
+
+ hash_for_each_possible(reg->entries_hash, e, hentry, hash)
+ if (strcmp(e->name, name) == 0)
+ return e;
+
+ return NULL;
+}
+
+/**
+ * kdbus_name_lookup_unlocked() - lookup name in registry
+ * @reg: name registry
+ * @name: name to lookup
+ *
+ * This looks up @name in the given name-registry and returns the
+ * kdbus_name_entry object. The caller must hold the registry-lock and must not
+ * access the returned object after releasing the lock.
+ *
+ * Return: Pointer to name-entry, or NULL if not found.
+ */
+struct kdbus_name_entry *
+kdbus_name_lookup_unlocked(struct kdbus_name_registry *reg, const char *name)
+{
+ return kdbus_name_find(reg, kdbus_strhash(name), name);
+}
+
+/**
+ * kdbus_name_acquire() - acquire a name
+ * @reg: The name registry
+ * @conn: The connection to pin this entry to
+ * @name: The name to acquire
+ * @flags: Acquisition flags (KDBUS_NAME_*)
+ * @return_flags: Pointer to return flags for the acquired name
+ * (KDBUS_NAME_*), may be %NULL
+ *
+ * Callers must ensure that @conn is either a privileged bus user or has
+ * sufficient privileges in the policy-db to own the well-known name @name.
+ *
+ * Return: 0 success, negative error number on failure.
+ */
+int kdbus_name_acquire(struct kdbus_name_registry *reg,
+ struct kdbus_conn *conn, const char *name,
+ u64 flags, u64 *return_flags)
+{
+ struct kdbus_name_entry *e;
+ u64 rflags = 0;
+ int ret = 0;
+ u32 hash;
+
+ kdbus_conn_assert_active(conn);
+
+ down_write(®->rwlock);
+
+ if (!kdbus_conn_policy_own_name(conn, current_cred(), name)) {
+ ret = -EPERM;
+ goto exit_unlock;
+ }
+
+ hash = kdbus_strhash(name);
+ e = kdbus_name_find(reg, hash, name);
+ if (!e) {
+ /* claim new name */
+
+ if (conn->activator_of) {
+ ret = -EINVAL;
+ goto exit_unlock;
+ }
+
+ e = kdbus_name_entry_new(reg, hash, name);
+ if (IS_ERR(e)) {
+ ret = PTR_ERR(e);
+ goto exit_unlock;
+ }
+
+ if (kdbus_conn_is_activator(conn)) {
+ e->activator = kdbus_conn_ref(conn);
+ conn->activator_of = e;
+ }
+
+ kdbus_name_entry_set_owner(e, conn, flags);
+ kdbus_notify_name_change(e->conn->ep->bus, KDBUS_ITEM_NAME_ADD,
+ 0, e->conn->id, 0, e->flags, e->name);
+ } else if (e->conn == conn || e == conn->activator_of) {
+ /* connection already owns that name */
+ ret = -EALREADY;
+ } else if (kdbus_conn_is_activator(conn)) {
+ /* activator claims existing name */
+
+ if (conn->activator_of) {
+ ret = -EINVAL; /* multiple names not allowed */
+ } else if (e->activator) {
+ ret = -EEXIST; /* only one activator per name */
+ } else {
+ e->activator = kdbus_conn_ref(conn);
+ conn->activator_of = e;
+ }
+ } else if (e->flags & KDBUS_NAME_ACTIVATOR) {
+ /* claim name of an activator */
+
+ kdbus_conn_move_messages(conn, e->activator, 0);
+ kdbus_name_entry_replace_owner(e, conn, flags);
+ } else if ((flags & KDBUS_NAME_REPLACE_EXISTING) &&
+ (e->flags & KDBUS_NAME_ALLOW_REPLACEMENT)) {
+ /* claim name of a previous owner */
+
+ if (e->flags & KDBUS_NAME_QUEUE) {
+ /* move owner back to queue if they asked for it */
+ ret = kdbus_name_pending_new(e, e->conn, e->flags);
+ if (ret < 0)
+ goto exit_unlock;
+ }
+
+ kdbus_name_entry_replace_owner(e, conn, flags);
+ } else if (flags & KDBUS_NAME_QUEUE) {
+ /* add to waiting-queue of the name */
+
+ ret = kdbus_name_pending_new(e, conn, flags);
+ if (ret >= 0)
+ /* tell the caller that we queued it */
+ rflags |= KDBUS_NAME_IN_QUEUE;
+ } else {
+ /* the name is busy, return a failure */
+ ret = -EEXIST;
+ }
+
+ if (ret == 0 && return_flags)
+ *return_flags = rflags;
+
+exit_unlock:
+ up_write(®->rwlock);
+ kdbus_notify_flush(conn->ep->bus);
+ return ret;
+}
+
+static void kdbus_name_release_unlocked(struct kdbus_name_registry *reg,
+ struct kdbus_name_entry *e)
+{
+ struct kdbus_name_pending *p;
+
+ lockdep_assert_held(®->rwlock);
+
+ p = list_first_entry_or_null(&e->queue, struct kdbus_name_pending,
+ name_entry);
+
+ if (p) {
+ /* give it to first active waiter in the queue */
+ kdbus_name_entry_replace_owner(e, p->conn, p->flags);
+ kdbus_name_pending_free(p);
+ } else if (e->activator && e->activator != e->conn) {
+ /* hand it back to an active activator connection */
+ kdbus_conn_move_messages(e->activator, e->conn, e->name_id);
+ kdbus_name_entry_replace_owner(e, e->activator,
+ KDBUS_NAME_ACTIVATOR);
+ } else {
+ /* release the name */
+ kdbus_notify_name_change(e->conn->ep->bus,
+ KDBUS_ITEM_NAME_REMOVE,
+ e->conn->id, 0, e->flags, 0, e->name);
+ kdbus_name_entry_remove_owner(e);
+ kdbus_name_entry_free(e);
+ }
+}
+
+static int kdbus_name_release(struct kdbus_name_registry *reg,
+ struct kdbus_conn *conn,
+ const char *name)
+{
+ struct kdbus_name_pending *p;
+ struct kdbus_name_entry *e;
+ int ret = 0;
+
+ down_write(®->rwlock);
+ e = kdbus_name_find(reg, kdbus_strhash(name), name);
+ if (!e) {
+ ret = -ESRCH;
+ } else if (e->conn == conn) {
+ kdbus_name_release_unlocked(reg, e);
+ } else {
+ ret = -EADDRINUSE;
+ list_for_each_entry(p, &e->queue, name_entry) {
+ if (p->conn == conn) {
+ kdbus_name_pending_free(p);
+ ret = 0;
+ break;
+ }
+ }
+ }
+ up_write(®->rwlock);
+
+ kdbus_notify_flush(conn->ep->bus);
+ return ret;
+}
+
+/**
+ * kdbus_name_release_all() - remove all name entries of a given connection
+ * @reg: name registry
+ * @conn: connection
+ */
+void kdbus_name_release_all(struct kdbus_name_registry *reg,
+ struct kdbus_conn *conn)
+{
+ struct kdbus_name_pending *p;
+ struct kdbus_conn *activator = NULL;
+ struct kdbus_name_entry *e;
+
+ down_write(®->rwlock);
+
+ if (kdbus_conn_is_activator(conn)) {
+ activator = conn->activator_of->activator;
+ conn->activator_of->activator = NULL;
+ }
+
+ while ((p = list_first_entry_or_null(&conn->names_queue_list,
+ struct kdbus_name_pending,
+ conn_entry)))
+ kdbus_name_pending_free(p);
+ while ((e = list_first_entry_or_null(&conn->names_list,
+ struct kdbus_name_entry,
+ conn_entry)))
+ kdbus_name_release_unlocked(reg, e);
+
+ up_write(®->rwlock);
+
+ kdbus_conn_unref(activator);
+ kdbus_notify_flush(conn->ep->bus);
+}
+
+/**
+ * kdbus_cmd_name_acquire() - handle KDBUS_CMD_NAME_ACQUIRE
+ * @conn: connection to operate on
+ * @argp: command payload
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kdbus_cmd_name_acquire(struct kdbus_conn *conn, void __user *argp)
+{
+ const char *item_name;
+ struct kdbus_cmd *cmd;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ { .type = KDBUS_ITEM_NAME, .mandatory = true },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE |
+ KDBUS_NAME_REPLACE_EXISTING |
+ KDBUS_NAME_ALLOW_REPLACEMENT |
+ KDBUS_NAME_QUEUE,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ if (!kdbus_conn_is_ordinary(conn))
+ return -EOPNOTSUPP;
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ item_name = argv[1].item->str;
+ if (!kdbus_name_is_valid(item_name, false)) {
+ ret = -EINVAL;
+ goto exit;
+ }
+
+ /*
+ * Do atomic_inc_return here to reserve our slot, then decrement
+ * it before returning.
+ */
+ if (atomic_inc_return(&conn->name_count) > KDBUS_CONN_MAX_NAMES) {
+ ret = -E2BIG;
+ goto exit_dec;
+ }
+
+ ret = kdbus_name_acquire(conn->ep->bus->name_registry, conn, item_name,
+ cmd->flags, &cmd->return_flags);
+ if (ret < 0)
+ goto exit_dec;
+
+exit_dec:
+ atomic_dec(&conn->name_count);
+exit:
+ return kdbus_args_clear(&args, ret);
+}
+
+/**
+ * kdbus_cmd_name_release() - handle KDBUS_CMD_NAME_RELEASE
+ * @conn: connection to operate on
+ * @argp: command payload
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kdbus_cmd_name_release(struct kdbus_conn *conn, void __user *argp)
+{
+ struct kdbus_cmd *cmd;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ { .type = KDBUS_ITEM_NAME, .mandatory = true },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ if (!kdbus_conn_is_ordinary(conn))
+ return -EOPNOTSUPP;
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ ret = kdbus_name_release(conn->ep->bus->name_registry, conn,
+ argv[1].item->str);
+ return kdbus_args_clear(&args, ret);
+}
+
+static int kdbus_list_write(struct kdbus_conn *conn,
+ struct kdbus_conn *c,
+ struct kdbus_pool_slice *slice,
+ size_t *pos,
+ struct kdbus_name_entry *e,
+ bool write)
+{
+ struct kvec kvec[4];
+ size_t cnt = 0;
+ int ret;
+
+ /* info header */
+ struct kdbus_info info = {
+ .size = 0,
+ .id = c->id,
+ .flags = c->flags,
+ };
+
+ /* fake the header of a kdbus_name item */
+ struct {
+ u64 size;
+ u64 type;
+ u64 flags;
+ } h = {};
+
+ if (e && !kdbus_conn_policy_see_name_unlocked(conn, current_cred(),
+ e->name))
+ return 0;
+
+ kdbus_kvec_set(&kvec[cnt++], &info, sizeof(info), &info.size);
+
+ /* append name */
+ if (e) {
+ size_t slen = strlen(e->name) + 1;
+
+ h.size = offsetof(struct kdbus_item, name.name) + slen;
+ h.type = KDBUS_ITEM_OWNED_NAME;
+ h.flags = e->flags;
+
+ kdbus_kvec_set(&kvec[cnt++], &h, sizeof(h), &info.size);
+ kdbus_kvec_set(&kvec[cnt++], e->name, slen, &info.size);
+ cnt += !!kdbus_kvec_pad(&kvec[cnt], &info.size);
+ }
+
+ if (write) {
+ ret = kdbus_pool_slice_copy_kvec(slice, *pos, kvec,
+ cnt, info.size);
+ if (ret < 0)
+ return ret;
+ }
+
+ *pos += info.size;
+ return 0;
+}
+
+static int kdbus_list_all(struct kdbus_conn *conn, u64 flags,
+ struct kdbus_pool_slice *slice,
+ size_t *pos, bool write)
+{
+ struct kdbus_conn *c;
+ size_t p = *pos;
+ int ret, i;
+
+ hash_for_each(conn->ep->bus->conn_hash, i, c, hentry) {
+ bool added = false;
+
+ /* skip monitors */
+ if (kdbus_conn_is_monitor(c))
+ continue;
+
+ /* skip activators */
+ if (!(flags & KDBUS_LIST_ACTIVATORS) &&
+ kdbus_conn_is_activator(c))
+ continue;
+
+ /* all names the connection owns */
+ if (flags & (KDBUS_LIST_NAMES | KDBUS_LIST_ACTIVATORS)) {
+ struct kdbus_name_entry *e;
+
+ list_for_each_entry(e, &c->names_list, conn_entry) {
+ struct kdbus_conn *a = e->activator;
+
+ if ((flags & KDBUS_LIST_ACTIVATORS) &&
+ a && a != c) {
+ ret = kdbus_list_write(conn, a, slice,
+ &p, e, write);
+ if (ret < 0) {
+ mutex_unlock(&c->lock);
+ return ret;
+ }
+
+ added = true;
+ }
+
+ if (flags & KDBUS_LIST_NAMES ||
+ kdbus_conn_is_activator(c)) {
+ ret = kdbus_list_write(conn, c, slice,
+ &p, e, write);
+ if (ret < 0) {
+ mutex_unlock(&c->lock);
+ return ret;
+ }
+
+ added = true;
+ }
+ }
+ }
+
+ /* queue of names the connection is currently waiting for */
+ if (flags & KDBUS_LIST_QUEUED) {
+ struct kdbus_name_pending *q;
+
+ list_for_each_entry(q, &c->names_queue_list,
+ conn_entry) {
+ ret = kdbus_list_write(conn, c, slice, &p,
+ q->name, write);
+ if (ret < 0) {
+ mutex_unlock(&c->lock);
+ return ret;
+ }
+
+ added = true;
+ }
+ }
+
+ /* nothing added so far, just add the unique ID */
+ if (!added && flags & KDBUS_LIST_UNIQUE) {
+ ret = kdbus_list_write(conn, c, slice, &p, NULL, write);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
+ *pos = p;
+ return 0;
+}
+
+/**
+ * kdbus_cmd_list() - handle KDBUS_CMD_LIST
+ * @conn: connection to operate on
+ * @argp: command payload
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kdbus_cmd_list(struct kdbus_conn *conn, void __user *argp)
+{
+ struct kdbus_name_registry *reg = conn->ep->bus->name_registry;
+ struct kdbus_pool_slice *slice = NULL;
+ struct kdbus_cmd_list *cmd;
+ size_t pos, size;
+ int ret;
+
+ struct kdbus_arg argv[] = {
+ { .type = KDBUS_ITEM_NEGOTIATE },
+ };
+ struct kdbus_args args = {
+ .allowed_flags = KDBUS_FLAG_NEGOTIATE |
+ KDBUS_LIST_UNIQUE |
+ KDBUS_LIST_NAMES |
+ KDBUS_LIST_ACTIVATORS |
+ KDBUS_LIST_QUEUED,
+ .argv = argv,
+ .argc = ARRAY_SIZE(argv),
+ };
+
+ ret = kdbus_args_parse(&args, argp, &cmd);
+ if (ret != 0)
+ return ret;
+
+ /* lock order: domain -> bus -> ep -> names -> conn */
+ down_read(®->rwlock);
+ down_read(&conn->ep->bus->conn_rwlock);
+ down_read(&conn->ep->policy_db.entries_rwlock);
+
+ /* size of records */
+ size = 0;
+ ret = kdbus_list_all(conn, cmd->flags, NULL, &size, false);
+ if (ret < 0)
+ goto exit_unlock;
+
+ if (size == 0) {
+ kdbus_pool_publish_empty(conn->pool, &cmd->offset,
+ &cmd->list_size);
+ } else {
+ slice = kdbus_pool_slice_alloc(conn->pool, size, false);
+ if (IS_ERR(slice)) {
+ ret = PTR_ERR(slice);
+ slice = NULL;
+ goto exit_unlock;
+ }
+
+ /* copy the records */
+ pos = 0;
+ ret = kdbus_list_all(conn, cmd->flags, slice, &pos, true);
+ if (ret < 0)
+ goto exit_unlock;
+
+ WARN_ON(pos != size);
+ kdbus_pool_slice_publish(slice, &cmd->offset, &cmd->list_size);
+ }
+
+ if (kdbus_member_set_user(&cmd->offset, argp, typeof(*cmd), offset) ||
+ kdbus_member_set_user(&cmd->list_size, argp,
+ typeof(*cmd), list_size))
+ ret = -EFAULT;
+
+exit_unlock:
+ up_read(&conn->ep->policy_db.entries_rwlock);
+ up_read(&conn->ep->bus->conn_rwlock);
+ up_read(®->rwlock);
+ kdbus_pool_slice_release(slice);
+ return kdbus_args_clear(&args, ret);
+}
diff --git a/ipc/kdbus/names.h b/ipc/kdbus/names.h
new file mode 100644
index 000000000000..3dd2589293e0
--- /dev/null
+++ b/ipc/kdbus/names.h
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 2013-2015 Kay Sievers
+ * Copyright (C) 2013-2015 Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
+ * Copyright (C) 2013-2015 Daniel Mack <daniel@xxxxxxxxxx>
+ * Copyright (C) 2013-2015 David Herrmann <dh.herrmann@xxxxxxxxx>
+ * Copyright (C) 2013-2015 Linux Foundation
+ * Copyright (C) 2014-2015 Djalal Harouni <tixxdz@xxxxxxxxxx>
+ *
+ * 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.
+ */
+
+#ifndef __KDBUS_NAMES_H
+#define __KDBUS_NAMES_H
+
+#include <linux/hashtable.h>
+#include <linux/rwsem.h>
+
+/**
+ * struct kdbus_name_registry - names registered for a bus
+ * @entries_hash: Map of entries
+ * @lock: Registry data lock
+ * @name_seq_last: Last used sequence number to assign to a name entry
+ */
+struct kdbus_name_registry {
+ DECLARE_HASHTABLE(entries_hash, 8);
+ struct rw_semaphore rwlock;
+ u64 name_seq_last;
+};
+
+/**
+ * struct kdbus_name_entry - well-know name entry
+ * @name_id: Sequence number of name entry to be able to uniquely
+ * identify a name over its registration lifetime
+ * @flags: KDBUS_NAME_* flags
+ * @conn: Connection owning the name
+ * @activator: Connection of the activator queuing incoming messages
+ * @queue: List of queued connections
+ * @conn_entry: Entry in connection
+ * @hentry: Entry in registry map
+ * @name: The well-known name
+ */
+struct kdbus_name_entry {
+ u64 name_id;
+ u64 flags;
+ struct kdbus_conn *conn;
+ struct kdbus_conn *activator;
+ struct list_head queue;
+ struct list_head conn_entry;
+ struct hlist_node hentry;
+ char name[];
+};
+
+bool kdbus_name_is_valid(const char *p, bool allow_wildcard);
+
+struct kdbus_name_registry *kdbus_name_registry_new(void);
+void kdbus_name_registry_free(struct kdbus_name_registry *reg);
+
+struct kdbus_name_entry *
+kdbus_name_lookup_unlocked(struct kdbus_name_registry *reg, const char *name);
+
+int kdbus_name_acquire(struct kdbus_name_registry *reg,
+ struct kdbus_conn *conn, const char *name,
+ u64 flags, u64 *return_flags);
+void kdbus_name_release_all(struct kdbus_name_registry *reg,
+ struct kdbus_conn *conn);
+
+int kdbus_cmd_name_acquire(struct kdbus_conn *conn, void __user *argp);
+int kdbus_cmd_name_release(struct kdbus_conn *conn, void __user *argp);
+int kdbus_cmd_list(struct kdbus_conn *conn, void __user *argp);
+
+#endif
--
2.3.1
--
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