by Luiz Augusto von Dentz

[permalink] [raw]

Subject: Re: [Bluez PATCH v2 08/11] plugins/admin_policy: listen for device add and remove

Hi Howard,

On Thu, Jul 22, 2021 at 12:23 AM Howard Chung <[email protected]> wrote:
>
> From: Yun-Hao Chung <[email protected]>
>
> This adds an D-BUS client to listen for DeviceAdd and DeviceRemove. It
> is necessary for implementation of "AffectedByPolicy" property since it
> needs to register an interface for each device object and unregister it
> once the device gets removed.
>
> Reviewed-by: Miao-chen Chou <[email protected]>
> ---
> The following test steps were performed:
> 1. start discovery using UI
> 2. verify device_data were added by checking system log
> 3. stop discovery
> 4. verify device_data were removed after a few seconds by checking
> system log
>
> (no changes since v1)
>
> plugins/admin_policy.c | 154 +++++++++++++++++++++++++++++++++++++++--
> 1 file changed, 150 insertions(+), 4 deletions(-)
>
> diff --git a/plugins/admin_policy.c b/plugins/admin_policy.c
> index 270d42366cd6..73d695ef976b 100644
> --- a/plugins/admin_policy.c
> +++ b/plugins/admin_policy.c
> @@ -20,6 +20,7 @@
>
> #include "src/adapter.h"
> #include "src/dbus-common.h"
> +#include "src/device.h"
> #include "src/error.h"
> #include "src/log.h"
> #include "src/plugin.h"
> @@ -29,7 +30,12 @@
> #define ADMIN_POLICY_SET_INTERFACE "org.bluez.AdminPolicySet1"
> #define ADMIN_POLICY_STATUS_INTERFACE "org.bluez.AdminPolicyStatus1"
>
> +#define DBUS_BLUEZ_SERVICE "org.bluez"
> +#define BTD_DEVICE_INTERFACE "org.bluez.Device1"
> +
> static DBusConnection *dbus_conn;
> +static GDBusClient *dbus_client;
> +static struct queue *devices; /* List of struct device_data objects */
>
> /* |policy_data| has the same life cycle as btd_adapter */
> static struct btd_admin_policy {
> @@ -38,6 +44,11 @@ static struct btd_admin_policy {
> struct queue *service_allowlist;
> } *policy_data = NULL;
>
> +struct device_data {
> + struct btd_device *device;
> + char *path;
> +};
> +
> static struct btd_admin_policy *admin_policy_new(struct btd_adapter *adapter)
> {
> struct btd_admin_policy *admin_policy = NULL;
> @@ -203,8 +214,122 @@ static const GDBusPropertyTable admin_policy_adapter_properties[] = {
> { }
> };
>
> +static bool device_data_match(const void *a, const void *b)
> +{
> + const struct device_data *data = a;
> + const struct btd_device *dev = b;
> +
> + if (!data) {
> + error("Unexpected NULL device_data");
> + return false;
> + }
> +
> + return data->device == dev;
> +}
> +
> +static bool device_data_match_by_path(const void *a, const void *b)
> +{
> + const struct device_data *data = a;
> + const char *path = b;
> +
> + if (!data) {
> + error("Unexpected NULL device_data");
> + return false;
> + }
> +
> + return strcmp(data->path, b) == 0;
> +}
> +
> +static void free_device_data(void *data)
> +{
> + struct device_data *device_data = data;
> +
> + g_free(device_data->path);
> + g_free(device_data);
> +}
> +
> +static void remove_device_data(void *data)
> +{
> + struct device_data *device_data = data;
> +
> + DBG("device_data for %s removing", device_data->path);
> +
> + queue_remove(devices, device_data);
> + free_device_data(device_data);
> +}
> +
> +static void add_device_data(struct btd_device *device)
> +{
> + struct btd_adapter *adapter = device_get_adapter(device);
> + struct device_data *data;
> +
> + if (queue_find(devices, device_data_match, device))
> + return;
> +
> + data = g_new0(struct device_data, 1);
> + if (!data) {
> + btd_error(btd_adapter_get_index(adapter),
> + "Failed to allocate memory for device_data");
> + return;
> + }
> +
> + data->device = device;
> + data->path = g_strdup(device_get_path(device));
> + queue_push_tail(devices, data);
> +
> + DBG("device_data for %s added", data->path);
> +}
> +
> +static struct btd_device *find_device_by_proxy(GDBusProxy *proxy)
> +{
> + const char *path = g_dbus_proxy_get_path(proxy);
> + const char *iface = g_dbus_proxy_get_interface(proxy);
> + struct btd_device *device;
> +
> + if (strcmp(iface, BTD_DEVICE_INTERFACE) != 0)
> + return NULL;
> +
> + device = btd_adapter_find_device_by_path(policy_data->adapter, path);
> +
> + if (!device) {
> + btd_warn(adapter_get_path(policy_data->adapter),
> + "Device path %s is not found", path);
> + }
> +
> + return device;
> +}
> +
> +static void object_added_cb(GDBusProxy *proxy, void *user_data)
> +{
> + struct btd_device *device;
> +
> + device = find_device_by_proxy(proxy);
> +
> + if (!device)
> + return;
> +
> + add_device_data(device);
> +}
> +
> +static void object_removed_cb(GDBusProxy *proxy, void *user_data)
> +{
> + const char *path = g_dbus_proxy_get_path(proxy);
> + const char *iface = g_dbus_proxy_get_interface(proxy);
> + struct device_data *data;
> +
> + if (strcmp(iface, BTD_DEVICE_INTERFACE) != 0)
> + return;
> +
> + data = queue_find(devices, device_data_match_by_path, path);
> +
> + if (data)
> + remove_device_data(data);
> +}
> +
> static int admin_policy_adapter_probe(struct btd_adapter *adapter)
> {
> + const char *adapter_path;
> +
> if (policy_data) {
> btd_warn(policy_data->adapter_id,
> "Policy data already exists");
> @@ -216,33 +341,43 @@ static int admin_policy_adapter_probe(struct btd_adapter *adapter)
> if (!policy_data)
> return -ENOMEM;
>
> - if (!g_dbus_register_interface(dbus_conn, adapter_get_path(adapter),
> + adapter_path = adapter_get_path(adapter);
> +
> + if (!g_dbus_register_interface(dbus_conn, adapter_path,
> ADMIN_POLICY_SET_INTERFACE,
> admin_policy_adapter_methods, NULL,
> NULL, policy_data, admin_policy_free)) {
> btd_error(policy_data->adapter_id,
> "Admin Policy Set interface init failed on path %s",
> - adapter_get_path(adapter));
> + adapter_path);
> return -EINVAL;
> }
>
> btd_info(policy_data->adapter_id,
> "Admin Policy Set interface registered");
>
> - if (!g_dbus_register_interface(dbus_conn, adapter_get_path(adapter),
> + if (!g_dbus_register_interface(dbus_conn, adapter_path,
> ADMIN_POLICY_STATUS_INTERFACE,
> NULL, NULL,
> admin_policy_adapter_properties,
> policy_data, admin_policy_free)) {
> btd_error(policy_data->adapter_id,
> "Admin Policy Status interface init failed on path %s",
> - adapter_get_path(adapter));
> + adapter_path);
> return -EINVAL;
> }
>
> btd_info(policy_data->adapter_id,
> "Admin Policy Status interface registered");
>
> + dbus_client = g_dbus_client_new(dbus_conn, DBUS_BLUEZ_SERVICE,
> + adapter_path);
> +
> + g_dbus_client_set_proxy_handlers(dbus_client, object_added_cb,
> + object_removed_cb, NULL, NULL);
> +
> + g_dbus_client_set_ready_watch(dbus_client, NULL, NULL);

I hope it wasn't one of my comments that led you to do this, because
it is really a bad idea to listen to our own signals like that since
it comes from the same process it just adds a round trip to the D-Bus
daemon for no reason. Perhaps we could extend the btd_adapter_driver
to have device_added/device_remove callbacks so whenever a new device
is added or removed the driver will get notified.

> +
> return 0;
> }
>
> @@ -257,6 +392,7 @@ static int admin_policy_init(void)
> DBG("");
>
> dbus_conn = btd_get_dbus_connection();
> + devices = queue_new();
>
> return btd_register_adapter_driver(&admin_policy_driver);
> }
> @@ -266,9 +402,19 @@ static void admin_policy_exit(void)
> DBG("");
>
> btd_unregister_adapter_driver(&admin_policy_driver);
> + queue_destroy(devices, free_device_data);
>
> if (policy_data)
> admin_policy_free(policy_data);
> +
> + if (dbus_client) {
> + g_dbus_client_set_disconnect_watch(dbus_client, NULL, NULL);
> + g_dbus_client_set_proxy_handlers(dbus_client, NULL, NULL, NULL,
> + NULL);
> + g_dbus_client_set_ready_watch(dbus_client, NULL, NULL);
> + g_dbus_client_unref(dbus_client);
> + dbus_client = NULL;
> + }
> }
>
> BLUETOOTH_PLUGIN_DEFINE(admin_policy, VERSION,
> --
> 2.32.0.402.g57bb445576-goog
>

--
Luiz Augusto von Dentz

2021-07-23 07:42:05

by Yun-hao Chung

[permalink] [raw]

Subject: Re: [Bluez PATCH v2 03/11] profiles: ignore incoming connection of not allowed service

Hi Bluez,

I'd like to discuss this patch. In this patch, I add
btd_adapter_is_uuid_allowed to the connected callback of bt_io_listen
in each profile. However, it introduces a dependency of src/adapter to
profiles/health/mcap, which is used in tools/mcaptests, therefore
making mcaptest unable to be built.
I wonder should we modify mcaptest in this case? I also notice that it
is the only profile that does not call btd_request_authorization in
bt_io connect_callback.

Thanks.

On Thu, Jul 22, 2021 at 3:23 PM Howard Chung <[email protected]> wrote:
>
> From: Yun-Hao Chung <[email protected]>
>
> Bluez listens for incoming connections for each profile. This patch
> ignores them if the service is not allowed by adapter.
>
> Reviewed-by: Miao-chen Chou <[email protected]>
> ---
> Hi maintainers,
>
> In previous work of service_api, it blocks incoming connections by
> adding a check in profile authorization callback. This doesn't work for
> every profile, since some profile (e.g. health) doesn't need
> authorization. This change adds check to each profile. I understand it's
> not a very clean solution. Please let me know if you have other
> thoughts. Thanks.
>
> The following test steps were performed after enabling admin_policy
> plugin:
> 1. Set ServiceAllowList to ["1234"].
> 2. Turn on a paired classic keyboard. Verify it can not be connected.
> 3. Set ServiceAllowList to
> ["1800","1801","180A","180F","1812"]
> 4. Turn off and turn on the keyboard. Verift it can be connected.
>
> (no changes since v1)
>
> Makefile.tools | 1 +
> profiles/audio/a2dp.c | 6 ++++++
> profiles/audio/avctp.c | 7 +++++++
> profiles/health/mcap.c | 10 +++++++++-
> profiles/input/server.c | 10 ++++++++++
> src/profile.c | 12 ++++++++++++
> 6 files changed, 45 insertions(+), 1 deletion(-)
>
> diff --git a/Makefile.tools b/Makefile.tools
> index c836b5984934..55684824fb91 100644
> --- a/Makefile.tools
> +++ b/Makefile.tools
> @@ -235,6 +235,7 @@ tools_btiotest_LDADD = lib/libbluetooth-internal.la $(GLIB_LIBS)
> tools_mcaptest_SOURCES = tools/mcaptest.c \
> btio/btio.h btio/btio.c \
> src/log.c src/log.h \
> + src/adapter.c src/adapter.h \
> profiles/health/mcap.h profiles/health/mcap.c
> tools_mcaptest_LDADD = lib/libbluetooth-internal.la $(GLIB_LIBS) \
> src/libshared-mainloop.la -lrt
> diff --git a/profiles/audio/a2dp.c b/profiles/audio/a2dp.c
> index 86bc02994f75..73cf210475bd 100644
> --- a/profiles/audio/a2dp.c
> +++ b/profiles/audio/a2dp.c
> @@ -2386,6 +2386,12 @@ static void confirm_cb(GIOChannel *io, gpointer data)
> return;
> }
>
> + if (!btd_adapter_is_uuid_allowed(adapter_find(&src),
> + ADVANCED_AUDIO_UUID)) {
> + info("A2DP is not allowed. Ignoring the incoming connection");
> + return;
> + }
> +
> chan = channel_new(server, device, io);
> if (!chan)
> goto drop;
> diff --git a/profiles/audio/avctp.c b/profiles/audio/avctp.c
> index 50de3361818f..044c10d213ac 100644
> --- a/profiles/audio/avctp.c
> +++ b/profiles/audio/avctp.c
> @@ -1587,6 +1587,13 @@ static void avctp_confirm_cb(GIOChannel *chan, gpointer data)
>
> DBG("AVCTP: incoming connect from %s", address);
>
> + if (!btd_adapter_is_uuid_allowed(adapter_find(&src),
> + AVRCP_REMOTE_UUID)) {
> + info("AVRCP REMOTE is not allowed. "
> + "Ignoring the incoming connection");
> + return;
> + }
> +
> device = btd_adapter_find_device(adapter_find(&src), &dst,
> BDADDR_BREDR);
> if (!device)
> diff --git a/profiles/health/mcap.c b/profiles/health/mcap.c
> index be13af37a0b8..1799d73e6648 100644
> --- a/profiles/health/mcap.c
> +++ b/profiles/health/mcap.c
> @@ -23,8 +23,10 @@
> #include <glib.h>
>
> #include "lib/bluetooth.h"
> +#include "lib/uuid.h"
> #include "bluetooth/l2cap.h"
> #include "btio/btio.h"
> +#include "src/adapter.h"
> #include "src/log.h"
> #include "src/shared/timeout.h"
>
> @@ -2010,7 +2012,7 @@ static void connect_mcl_event_cb(GIOChannel *chan, GError *gerr,
> {
> struct mcap_instance *mi = user_data;
> struct mcap_mcl *mcl;
> - bdaddr_t dst;
> + bdaddr_t src, dst;
> char address[18], srcstr[18];
> GError *err = NULL;
>
> @@ -2018,6 +2020,7 @@ static void connect_mcl_event_cb(GIOChannel *chan, GError *gerr,
> return;
>
> bt_io_get(chan, &err,
> + BT_IO_OPT_SOURCE_BDADDR, &src,
> BT_IO_OPT_DEST_BDADDR, &dst,
> BT_IO_OPT_DEST, address,
> BT_IO_OPT_INVALID);
> @@ -2027,6 +2030,11 @@ static void connect_mcl_event_cb(GIOChannel *chan, GError *gerr,
> goto drop;
> }
>
> + if (!btd_adapter_is_uuid_allowed(adapter_find(&src), HDP_UUID)) {
> + info("HID is not allowed. Ignoring the incoming connection");
> + return;
> + }
> +
> ba2str(&mi->src, srcstr);
> mcl = find_mcl(mi->mcls, &dst);
> if (mcl) {
> diff --git a/profiles/input/server.c b/profiles/input/server.c
> index 79cf08a66b38..94d06a383578 100644
> --- a/profiles/input/server.c
> +++ b/profiles/input/server.c
> @@ -156,6 +156,11 @@ static void connect_event_cb(GIOChannel *chan, GError *err, gpointer data)
> ba2str(&dst, address);
> DBG("Incoming connection from %s on PSM %d", address, psm);
>
> + if (!btd_adapter_is_uuid_allowed(adapter_find(&src), HID_UUID)) {
> + info("HID is not allowed. Ignoring the incoming connection");
> + return;
> + }
> +
> ret = input_device_set_channel(&src, &dst, psm, chan);
> if (ret == 0)
> return;
> @@ -234,6 +239,11 @@ static void confirm_event_cb(GIOChannel *chan, gpointer user_data)
> return;
> }
>
> + if (!btd_adapter_is_uuid_allowed(adapter_find(&src), HID_UUID)) {
> + info("HID is not allowed. Ignoring the incoming connection");
> + return;
> + }
> +
> ba2str(&dst, addr);
>
> if (server->confirm) {
> diff --git a/src/profile.c b/src/profile.c
> index 60d17b6ae657..58500c74746d 100644
> --- a/src/profile.c
> +++ b/src/profile.c
> @@ -1249,6 +1249,11 @@ static void ext_confirm(GIOChannel *io, gpointer user_data)
>
> DBG("incoming connect from %s", addr);
>
> + if (btd_adapter_is_uuid_allowed(adapter_find(&src), uuid)) {
> + info("UUID %s is not allowed. Igoring the connection", uuid);
> + return;
> + }
> +
> conn = create_conn(server, io, &src, &dst);
> if (conn == NULL)
> return;
> @@ -1272,6 +1277,7 @@ static void ext_direct_connect(GIOChannel *io, GError *err, gpointer user_data)
> struct ext_profile *ext = server->ext;
> GError *gerr = NULL;
> struct ext_io *conn;
> + const char *uuid = ext->service ? ext->service : ext->uuid;
> bdaddr_t src, dst;
>
> bt_io_get(io, &gerr,
> @@ -1285,6 +1291,12 @@ static void ext_direct_connect(GIOChannel *io, GError *err, gpointer user_data)
> return;
> }
>
> + if (btd_adapter_is_uuid_allowed(adapter_find(&src), ext->uuid)) {
> + info("UUID %s is not allowed. Igoring the connection",
> + ext->uuid);
> + return;
> + }
> +
> conn = create_conn(server, io, &src, &dst);
> if (conn == NULL)
> return;
> --
> 2.32.0.402.g57bb445576-goog
>