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Date:   Sat, 11 Jan 2020 07:34:25 +0100
From:   =?utf-8?Q?Micha=C5=82?= Lowas-Rzechonek 
        <michal.lowas-rzechonek@silvair.com>
To:     Brian Gix <brian.gix@intel.com>
Cc:     linux-bluetooth@vger.kernel.org, inga.stotland@intel.com
Subject: Re: [PATCH BlueZ v3 1/1] mesh: Implement provisioning loop-back
Message-ID: <20200111063425.5sn6mvrlu3rkx3ka@kynes>
Mail-Followup-To: Brian Gix <brian.gix@intel.com>,
        linux-bluetooth@vger.kernel.org, inga.stotland@intel.com
References: <20200111013856.32675-1-brian.gix@intel.com>
 <20200111013856.32675-2-brian.gix@intel.com>
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Hi Brian,

On 01/10, Brian Gix wrote:
> This allows one App using the mesh daemon to provision another.
> ---
>  mesh/pb-adv.c | 163 ++++++++++++++++++++++++++++++++++++++++----------
>  1 file changed, 130 insertions(+), 33 deletions(-)
> 
> diff --git a/mesh/pb-adv.c b/mesh/pb-adv.c
> index c9a2a6574..4767908f3 100644
> --- a/mesh/pb-adv.c
> +++ b/mesh/pb-adv.c
> @@ -39,6 +39,7 @@ struct pb_adv_session {
>  	mesh_prov_receive_func_t rx_cb;
>  	mesh_prov_ack_func_t ack_cb;
>  	struct l_timeout *tx_timeout;
> +	struct pb_adv_session *loop;
>  	uint32_t link_id;
>  	uint16_t exp_len;
>  	uint8_t exp_fcs;
> @@ -93,10 +94,43 @@ struct pb_close_ind {
>  	uint8_t reason;
>  } __packed;

By the way, why is this struct packed?

>  
> -static struct pb_adv_session *pb_session = NULL;
> +struct idle_rx {
> +	struct pb_adv_session *session;
> +	uint16_t len;
> +	uint8_t data[PB_ADV_MTU + 6];
> +};
> +
> +static struct l_queue *pb_sessions = NULL;
>  
>  static const uint8_t filter[1] = { MESH_AD_TYPE_PROVISION };
>  
> +static void pb_adv_packet(void *user_data, const uint8_t *pkt, uint16_t len);
> +
> +static void idle_rx_adv(void *user_data)
> +{
> +	struct idle_rx *rx = user_data;
> +
> +	pb_adv_packet(rx->session, rx->data, rx->len);
> +	l_free(rx);
> +}
> +
> +static void pb_adv_send(struct pb_adv_session *session,
> +					uint8_t count, uint16_t interval,
> +					void *data, uint16_t len)
> +{
> +	struct idle_rx *rx = l_new(struct idle_rx, 1);

This leaks memory.

> +
> +	if (session->loop) {
> +		rx = l_new(struct idle_rx, 1);
> +		rx->session = session->loop;
> +		rx->len = len;
> +		memcpy(rx->data, data, len);
> +
> +		l_idle_oneshot(idle_rx_adv, rx, NULL);
> +	} else
> +		mesh_send_pkt(count, interval, data, len);
> +}
> +
>  static void send_adv_segs(struct pb_adv_session *session, const uint8_t *data,
>  							uint16_t size)
>  {
> @@ -135,7 +169,9 @@ static void send_adv_segs(struct pb_adv_session *session, const uint8_t *data,
>  	l_debug("max_seg: %2.2x", max_seg);
>  	l_debug("size: %2.2x, CRC: %2.2x", size, buf[9]);
>  	/* print_packet("PB-TX", buf + 1, init_size + 9); */
> -	mesh_send_pkt(MESH_IO_TX_COUNT_UNLIMITED, 200, buf, init_size + 10);
> +
> +	pb_adv_send(session, MESH_IO_TX_COUNT_UNLIMITED, 200,
> +							buf, init_size + 10);
>  
>  	consumed = init_size;
>  
> @@ -152,19 +188,39 @@ static void send_adv_segs(struct pb_adv_session *session, const uint8_t *data,
>  
>  		/* print_packet("PB-TX", buf + 1, seg_size + 6); */
>  
> -		mesh_send_pkt(MESH_IO_TX_COUNT_UNLIMITED, 200,
> +		pb_adv_send(session, MESH_IO_TX_COUNT_UNLIMITED, 200,
>  							buf, seg_size + 7);
>  
>  		consumed += seg_size;
>  	}
>  }
>  
> +static bool session_match (const void *a, const void *b)
> +{
> +	return a == b;
> +}
> +
> +static bool uuid_match (const void *a, const void *b)
> +{
> +	const struct pb_adv_session *session = a;
> +	const uint8_t *uuid = b;
> +
> +	return !memcmp(session->uuid, uuid, sizeof(session->uuid));
> +}
> +
> +static bool user_match (const void *a, const void *b)
> +{
> +	const struct pb_adv_session *session = a;
> +
> +	return session->user_data == b;
> +}
> +
>  static void tx_timeout(struct l_timeout *timeout, void *user_data)
>  {
>  	struct pb_adv_session *session = user_data;
>  	mesh_prov_close_func_t cb;
>  
> -	if (!session || pb_session != session)
> +	if (!l_queue_find(pb_sessions, session_match, session))
>  		return;
>  
>  	l_timeout_remove(session->tx_timeout);
> @@ -173,8 +229,8 @@ static void tx_timeout(struct l_timeout *timeout, void *user_data)
>  	mesh_send_cancel(filter, sizeof(filter));
>  
>  	l_info("TX timeout");
> -	cb = pb_session->close_cb;
> -	user_data = pb_session->user_data;
> +	cb = session->close_cb;
> +	user_data = session->user_data;
>  	cb(user_data, 1);
>  }
>  
> @@ -182,7 +238,7 @@ static void pb_adv_tx(void *user_data, void *data, uint16_t len)
>  {
>  	struct pb_adv_session *session = user_data;
>  
> -	if (!session || pb_session != session)
> +	if (!l_queue_find(pb_sessions, session_match, session))
>  		return;
>  
>  	l_timeout_remove(session->tx_timeout);
> @@ -201,7 +257,8 @@ static void send_open_req(struct pb_adv_session *session)
>  	memcpy(open_req.uuid, session->uuid, 16);
>  
>  	mesh_send_cancel(filter, sizeof(filter));
> -	mesh_send_pkt(MESH_IO_TX_COUNT_UNLIMITED, 500, &open_req,
> +
> +	pb_adv_send(session, MESH_IO_TX_COUNT_UNLIMITED, 500, &open_req,
>  							sizeof(open_req));
>  }
>  
> @@ -214,7 +271,8 @@ static void send_open_cfm(struct pb_adv_session *session)
>  	open_cfm.opcode = PB_ADV_OPEN_CFM;
>  
>  	mesh_send_cancel(filter, sizeof(filter));
> -	mesh_send_pkt(MESH_IO_TX_COUNT_UNLIMITED, 500, &open_cfm,
> +
> +	pb_adv_send(session, MESH_IO_TX_COUNT_UNLIMITED, 500, &open_cfm,
>  							sizeof(open_cfm));
>  }
>  
> @@ -222,18 +280,21 @@ static void send_ack(struct pb_adv_session *session, uint8_t trans_num)
>  {
>  	struct pb_ack ack = { MESH_AD_TYPE_PROVISION };
>  
> +	if (!l_queue_find(pb_sessions, session_match, session))
> +		return;
> +
>  	l_put_be32(session->link_id, &ack.link_id);
>  	ack.trans_num = trans_num;
>  	ack.opcode = PB_ADV_ACK;
>  
> -	mesh_send_pkt(1, 100, &ack, sizeof(ack));
> +	pb_adv_send(session, 1, 100, &ack, sizeof(ack));
>  }
>  
>  static void send_close_ind(struct pb_adv_session *session, uint8_t reason)
>  {
>  	struct pb_close_ind close_ind = { MESH_AD_TYPE_PROVISION };
>  
> -	if (!pb_session || pb_session != session)
> +	if (!l_queue_find(pb_sessions, session_match, session))
>  		return;
>  
>  	l_put_be32(session->link_id, &close_ind.link_id);
> @@ -242,7 +303,8 @@ static void send_close_ind(struct pb_adv_session *session, uint8_t reason)
>  	close_ind.reason = reason;
>  
>  	mesh_send_cancel(filter, sizeof(filter));
> -	mesh_send_pkt(10, 100, &close_ind, sizeof(close_ind));
> +
> +	pb_adv_send(session, 10, 100, &close_ind, sizeof(close_ind));
>  }
>  
>  static void pb_adv_packet(void *user_data, const uint8_t *pkt, uint16_t len)
> @@ -254,7 +316,7 @@ static void pb_adv_packet(void *user_data, const uint8_t *pkt, uint16_t len)
>  	uint8_t type;
>  	bool first;
>  
> -	if (!pb_session || pb_session != session)
> +	if (!l_queue_find(pb_sessions, session_match, session))
>  		return;
>  
>  	link_id = l_get_be32(pkt + 1);
> @@ -337,8 +399,8 @@ static void pb_adv_packet(void *user_data, const uint8_t *pkt, uint16_t len)
>  			mesh_prov_close_func_t cb = session->close_cb;
>  			void *user_data = session->user_data;
>  
> +			l_queue_remove(pb_sessions, session);
>  			l_free(session);
> -			pb_session = NULL;
>  			cb(user_data, pkt[0]);
>  		}
>  		break;
> @@ -442,37 +504,72 @@ bool pb_adv_reg(bool initiator, mesh_prov_open_func_t open_cb,
>  		mesh_prov_receive_func_t rx_cb, mesh_prov_ack_func_t ack_cb,
>  		uint8_t uuid[16], void *user_data)
>  {
> -	if (pb_session)
> +	struct pb_adv_session *session, *old_session;
> +
> +	if (!pb_sessions)
> +		pb_sessions = l_queue_new();
> +
> +	old_session = l_queue_find(pb_sessions, uuid_match, uuid);
> +
> +	/* Reject 2nd session if not looping back */
> +	if (l_queue_length(pb_sessions) && !old_session)
> +		return false;
> +
> +	/* Reject looping to more than one session or with same role*/
> +	if (old_session && (old_session->loop ||
> +					old_session->initiator == initiator))
>  		return false;
>  
> -	pb_session = l_new(struct pb_adv_session, 1);
> -	pb_session->open_cb = open_cb;
> -	pb_session->close_cb = close_cb;
> -	pb_session->rx_cb = rx_cb;
> -	pb_session->ack_cb = ack_cb;
> -	pb_session->user_data = user_data;
> -	pb_session->initiator = initiator;
> -	memcpy(pb_session->uuid, uuid, 16);
> +	session = l_new(struct pb_adv_session, 1);
> +	session->open_cb = open_cb;
> +	session->close_cb = close_cb;
> +	session->rx_cb = rx_cb;
> +	session->ack_cb = ack_cb;
> +	session->user_data = user_data;
> +	session->initiator = initiator;
> +	memcpy(session->uuid, uuid, 16);
>  
> -	mesh_reg_prov_rx(pb_adv_packet, pb_session);
> +	l_queue_push_head(pb_sessions, session);
>  
>  	if (initiator) {
> -		l_getrandom(&pb_session->link_id, sizeof(pb_session->link_id));
> -		pb_session->tx_timeout = l_timeout_create(60, tx_timeout,
> -							pb_session, NULL);
> -		send_open_req(pb_session);
> +		l_getrandom(&session->link_id, sizeof(session->link_id));
> +		session->tx_timeout = l_timeout_create(60, tx_timeout,
> +							session, NULL);
> +	}
> +
> +	/* Setup Loop-back if complementary session with same UUID */
> +	if (old_session) {
> +		session->loop = old_session;
> +		old_session->loop = session;
> +		mesh_unreg_prov_rx(pb_adv_packet);
> +
> +		if (initiator)
> +			send_open_req(session);
> +		else
> +			send_open_req(old_session);
> +
> +		return true;
>  	}
>  
> +	mesh_reg_prov_rx(pb_adv_packet, session);
> +
> +	if (initiator)
> +		send_open_req(session);
> +
>  	return true;
>  }
>  
>  void pb_adv_unreg(void *user_data)
>  {
> -	if (!pb_session || pb_session->user_data != user_data)
> +	struct pb_adv_session *session = l_queue_find(pb_sessions,
> +						user_match, user_data);
> +
> +	if (!session)
>  		return;
>  
> -	l_timeout_remove(pb_session->tx_timeout);
> -	send_close_ind(pb_session, 0);
> -	l_free(pb_session);
> -	pb_session = NULL;
> +	l_timeout_remove(session->tx_timeout);
> +	session->tx_timeout = NULL;
> +	send_close_ind(session, 0);
> +	l_queue_remove(pb_sessions, session);
> +	l_free(session);
>  }
> -- 
> 2.21.1
> 

-- 
Michał Lowas-Rzechonek <michal.lowas-rzechonek@silvair.com>
Silvair http://silvair.com
Jasnogórska 44, 31-358 Krakow, POLAND