[pulseaudio-discuss] [PATCHv2 30/60] bluetooth: Implement org.bluez.MediaEndpoint1.SetConfiguration()

[João Paulo Rechi Vita]

On Sun, Aug 18, 2013 at 6:03 AM, Tanu Kaskinen
<tanu.kaskinen at linux.intel.com> wrote:
> On Tue, 2013-08-13 at 01:54 -0300, jprvita at gmail.com wrote:
>> From: João Paulo Rechi Vita <jprvita at openbossa.org>
>>
>> ---
>>  src/modules/bluetooth/bluez5-util.c | 171 +++++++++++++++++++++++++++++++++++-
>>  src/modules/bluetooth/bluez5-util.h |   5 ++
>>  2 files changed, 174 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/modules/bluetooth/bluez5-util.c b/src/modules/bluetooth/bluez5-util.c
>> index 9687997..d0428a9 100644
>> --- a/src/modules/bluetooth/bluez5-util.c
>> +++ b/src/modules/bluetooth/bluez5-util.c
>> @@ -33,6 +33,8 @@
>>  #include <pulsecore/refcnt.h>
>>  #include <pulsecore/shared.h>
>>
>> +#include "a2dp-codecs.h"
>> +
>>  #include "bluez5-util.h"
>>
>>  #define BLUEZ_SERVICE "org.bluez"
>> @@ -359,12 +361,177 @@ fail:
>>      return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
>>  }
>>
>> +const char *pa_bluetooth_profile_to_string(pa_bluetooth_profile_t profile) {
>> +    switch(profile) {
>> +        case PROFILE_A2DP_SINK:
>> +            return "a2dp_sink";
>> +        case PROFILE_A2DP_SOURCE:
>> +            return "a2dp_source";
>> +        case PROFILE_OFF:
>> +            return "off";
>> +    }
>> +
>> +    return NULL;
>> +}
>> +
>>  static DBusMessage *endpoint_set_configuration(DBusConnection *conn, DBusMessage *m, void *userdata) {
>> +    pa_bluetooth_discovery *y = userdata;
>> +    pa_bluetooth_device *d;
>> +    pa_bluetooth_transport *t;
>> +    const char *sender, *path, *endpoint_path, *dev_path = NULL, *uuid = NULL;
>> +    uint8_t *config = NULL;
>
> config should be marked as const, because it will point to memory owned
> by the DBusMessage object.
>

Ok.

>> +    int size = 0;
>> +    pa_bluetooth_profile_t p = PROFILE_OFF;
>> +    DBusMessageIter args, props;
>>      DBusMessage *r;
>>
>> -    pa_assert_se(r = dbus_message_new_error(m, BLUEZ_MEDIA_ENDPOINT_INTERFACE ".Error.NotImplemented",
>> -                                            "Method not implemented"));
>> +    if (!dbus_message_iter_init(m, &args) || !pa_streq(dbus_message_get_signature(m), "oa{sv}")) {
>> +        pa_log_error("Invalid signature for method SetConfiguration()");
>> +        goto fail2;
>> +    }
>> +
>> +    dbus_message_iter_get_basic(&args, &path);
>> +
>> +    if (pa_hashmap_get(y->transports, path)) {
>> +        pa_log_error("Endpoint SetConfiguration(): Transport %s is already configured.", path);
>> +        goto fail2;
>> +    }
>> +
>> +    pa_assert_se(dbus_message_iter_next(&args));
>> +
>> +    dbus_message_iter_recurse(&args, &props);
>> +    if (dbus_message_iter_get_arg_type(&props) != DBUS_TYPE_DICT_ENTRY)
>> +        goto fail;
>> +
>> +    /* Read transport properties */
>> +    while (dbus_message_iter_get_arg_type(&props) == DBUS_TYPE_DICT_ENTRY) {
>> +        const char *key;
>> +        DBusMessageIter value, entry;
>> +        int var;
>> +
>> +        dbus_message_iter_recurse(&props, &entry);
>> +        dbus_message_iter_get_basic(&entry, &key);
>> +
>> +        dbus_message_iter_next(&entry);
>> +        dbus_message_iter_recurse(&entry, &value);
>> +
>> +        var = dbus_message_iter_get_arg_type(&value);
>> +
>> +        if (pa_streq(key, "UUID")) {
>> +            if (var != DBUS_TYPE_STRING) {
>> +                pa_log_error("Property %s of wrong type %c", key, (char)var);
>> +                goto fail;
>> +            }
>> +
>> +            dbus_message_iter_get_basic(&value, &uuid);
>> +        } else if (pa_streq(key, "Device")) {
>> +            if (var != DBUS_TYPE_OBJECT_PATH) {
>> +                pa_log_error("Property %s of wrong type %c", key, (char)var);
>> +                goto fail;
>> +            }
>> +
>> +            dbus_message_iter_get_basic(&value, &dev_path);
>> +        } else if (pa_streq(key, "Configuration")) {
>> +            DBusMessageIter array;
>> +            a2dp_sbc_t *c;
>> +
>> +            if (var != DBUS_TYPE_ARRAY) {
>> +                pa_log_error("Property %s of wrong type %c", key, (char)var);
>> +                goto fail;
>> +            }
>> +
>> +            dbus_message_iter_recurse(&value, &array);
>> +            var = dbus_message_iter_get_arg_type(&array);
>> +            if (var != DBUS_TYPE_BYTE) {
>> +                pa_log_error("%s is an array of wrong type %c", key, (char)var);
>> +                goto fail;
>> +            }
>> +
>> +            dbus_message_iter_get_fixed_array(&array, &config, &size);
>> +            c = (a2dp_sbc_t *) config;
>
> You should check that the config size is what you expect it to be.
>
> Also, casting the byte array to an a2dp_sbc_t pointer seems hazardous
> from memory alignment point of view. I think it would be best to copy
> the config to a real a2dp_sbc_t variable before accessing the config.
>

Why it is hazardous? The BlueZ' media API documentation explicitly
states that we should the binary blob as-is. From doc/media-api.txt:
"Configuration blob, it is used as it is so the size and byte order
must match.". Additionally, the a2dp_sbc_t struct is defined ia a
BlueZ header, which is duplicated in PulseAudio's tree.

> It would better to do the config validation later, after checking that
> the UUID matches the endpoint type, because if the UUID doesn't match,
> then the config is probably not what you expect it to be either.
> Checking the config too early may result in less clear error messages
> (it's better to complain about UUID mismatch than errors in the config).
>

Ok.

-- 
João Paulo Rechi Vita
http://about.me/jprvita