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From:   Yun-hao Chung <howardchung@google.com>
Date:   Fri, 23 Jul 2021 15:40:08 +0800
Message-ID: <CAPHZWUfuybt=UF-60NEB2+seYJkeywtdxs_7cnafDSW6rPv6rg@mail.gmail.com>
Subject: Re: [Bluez PATCH v2 03/11] profiles: ignore incoming connection of
 not allowed service
To:     Bluez mailing list <linux-bluetooth@vger.kernel.org>,
        Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc:     Yun-Hao Chung <howardchung@chromium.org>,
        Miao-chen Chou <mcchou@chromium.org>
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Precedence: bulk

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 <howardchung@google.com> wrote:
>
> From: Yun-Hao Chung <howardchung@chromium.org>
>
> 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 <mcchou@chromium.org>
> ---
> 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
>