Hi Marcel,
On Wed, Mar 18, 2020 at 4:13 AM Marcel Holtmann <marcel@xxxxxxxxxxxx> wrote:
>
> Hi Luiz,
>
> > This uses the DEFER_SETUP flag to group channels with
> > L2CAP_CREDIT_BASED_CONNECTION_REQ.
> >
> > Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
> > ---
> > include/net/bluetooth/l2cap.h | 5 ++
> > net/bluetooth/l2cap_core.c | 130 +++++++++++++++++++++++++++++++---
> > net/bluetooth/l2cap_sock.c | 13 ++--
> > 3 files changed, 133 insertions(+), 15 deletions(-)
> >
> > diff --git a/include/net/bluetooth/l2cap.h b/include/net/bluetooth/l2cap.h
> > index 537aaead259f..dada14d0622c 100644
> > --- a/include/net/bluetooth/l2cap.h
> > +++ b/include/net/bluetooth/l2cap.h
> > @@ -47,6 +47,7 @@
> > #define L2CAP_DEFAULT_ACC_LAT 0xFFFFFFFF
> > #define L2CAP_BREDR_MAX_PAYLOAD 1019 /* 3-DH5 packet */
> > #define L2CAP_LE_MIN_MTU 23
> > +#define L2CAP_ECRED_CONN_SCID_MAX 5
> >
> > #define L2CAP_DISC_TIMEOUT msecs_to_jiffies(100)
> > #define L2CAP_DISC_REJ_TIMEOUT msecs_to_jiffies(5000)
> > @@ -660,6 +661,7 @@ struct l2cap_ops {
> > void (*suspend) (struct l2cap_chan *chan);
> > void (*set_shutdown) (struct l2cap_chan *chan);
> > long (*get_sndtimeo) (struct l2cap_chan *chan);
> > + struct pid *(*get_peer_pid) (struct l2cap_chan *chan);
>
> I would move this support into a separate patch. I think that can be applied independently.
Will do.
> > struct sk_buff *(*alloc_skb) (struct l2cap_chan *chan,
> > unsigned long hdr_len,
> > unsigned long len, int nb);
> > @@ -983,6 +985,9 @@ void l2cap_chan_set_defaults(struct l2cap_chan *chan);
> > int l2cap_ertm_init(struct l2cap_chan *chan);
> > void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan);
> > void __l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan);
> > +typedef void (*l2cap_chan_func_t)(struct l2cap_chan *chan, void *data);
> > +void l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func,
> > + void *data);
> > void l2cap_chan_del(struct l2cap_chan *chan, int err);
> > void l2cap_send_conn_req(struct l2cap_chan *chan);
> > void l2cap_move_start(struct l2cap_chan *chan);
> > diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
> > index 5e6e35ab44dd..20c1d5f9c238 100644
> > --- a/net/bluetooth/l2cap_core.c
> > +++ b/net/bluetooth/l2cap_core.c
> > @@ -678,6 +678,29 @@ void l2cap_chan_del(struct l2cap_chan *chan, int err)
> > }
> > EXPORT_SYMBOL_GPL(l2cap_chan_del);
> >
> > +static void __l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func,
> > + void *data)
> > +{
> > + struct l2cap_chan *chan;
> > +
> > + list_for_each_entry(chan, &conn->chan_l, list) {
> > + func(chan, data);
> > + }
> > +}
> > +
> > +void l2cap_chan_list(struct l2cap_conn *conn, l2cap_chan_func_t func,
> > + void *data)
> > +{
> > + if (!conn)
> > + return;
> > +
> > + mutex_lock(&conn->chan_lock);
> > + __l2cap_chan_list(conn, func, data);
> > + mutex_unlock(&conn->chan_lock);
> > +}
> > +
> > +EXPORT_SYMBOL_GPL(l2cap_chan_list);
> > +
> > static void l2cap_conn_update_id_addr(struct work_struct *work)
> > {
> > struct l2cap_conn *conn = container_of(work, struct l2cap_conn,
> > @@ -1356,29 +1379,77 @@ static void l2cap_le_connect(struct l2cap_chan *chan)
> > sizeof(req), &req);
> > }
> >
> > -static void l2cap_ecred_connect(struct l2cap_chan *chan)
> > -{
> > - struct l2cap_conn *conn = chan->conn;
> > +struct l2cap_ecred_conn_data {
> > struct {
> > struct l2cap_ecred_conn_req req;
> > - __le16 scid;
> > + __le16 scid[5];
> > } __packed pdu;
> > + struct l2cap_chan *chan;
> > + struct pid *pid;
> > + int count;
> > +};
> > +
> > +static void l2cap_ecred_defer_connect(struct l2cap_chan *chan, void *data)
> > +{
> > + struct l2cap_ecred_conn_data *conn = data;
> > + struct pid *pid;
> > +
> > + if (chan == conn->chan)
> > + return;
> > +
> > + if (!test_and_clear_bit(FLAG_DEFER_SETUP, &chan->flags))
> > + return;
> > +
> > + pid = chan->ops->get_peer_pid(chan);
> > +
> > + /* Only add deferred channels with the same PID/PSM */
> > + if (conn->pid != pid || chan->psm != conn->chan->psm || chan->ident ||
> > + chan->mode != L2CAP_MODE_EXT_FLOWCTL || chan->state != BT_CONNECT)
> > + return;
> > +
> > + if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
> > + return;
> > +
> > + /* Set the same ident so we can match on the rsp */
> > + chan->ident = conn->chan->ident;
> > +
> > + /* Include all channels deferred */
> > + conn->pdu.scid[conn->count] = cpu_to_le16(chan->scid);
> > +
> > + conn->count++;
> > +}
> > +
> > +static void l2cap_ecred_connect(struct l2cap_chan *chan)
> > +{
> > + struct l2cap_conn *conn = chan->conn;
> > + struct l2cap_ecred_conn_data data;
> > +
> > + if (test_bit(FLAG_DEFER_SETUP, &chan->flags))
> > + return;
> >
> > if (test_and_set_bit(FLAG_ECRED_CONN_REQ_SENT, &chan->flags))
> > return;
> >
> > l2cap_ecred_init(chan, 0);
> >
> > - pdu.req.psm = chan->psm;
> > - pdu.req.mtu = cpu_to_le16(chan->imtu);
> > - pdu.req.mps = cpu_to_le16(chan->mps);
> > - pdu.req.credits = cpu_to_le16(chan->rx_credits);
> > - pdu.scid = cpu_to_le16(chan->scid);
> > + data.pdu.req.psm = chan->psm;
> > + data.pdu.req.mtu = cpu_to_le16(chan->imtu);
> > + data.pdu.req.mps = cpu_to_le16(chan->mps);
> > + data.pdu.req.credits = cpu_to_le16(chan->rx_credits);
> > + data.pdu.scid[0] = cpu_to_le16(chan->scid);
> >
> > chan->ident = l2cap_get_ident(conn);
> > + data.pid = chan->ops->get_peer_pid(chan);
> > +
> > + data.count = 1;
> > + data.chan = chan;
> > + data.pid = chan->ops->get_peer_pid(chan);
> > +
> > + __l2cap_chan_list(conn, l2cap_ecred_defer_connect, &data);
> >
> > l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_CONN_REQ,
> > - sizeof(pdu), &pdu);
> > + sizeof(data.pdu.req) + data.count * sizeof(__le16),
> > + &data.pdu);
> > }
> >
> > static void l2cap_le_start(struct l2cap_chan *chan)
> > @@ -7694,6 +7765,29 @@ static bool is_valid_psm(u16 psm, u8 dst_type) {
> > return ((psm & 0x0101) == 0x0001);
> > }
> >
> > +struct l2cap_chan_data {
> > + struct l2cap_chan *chan;
> > + struct pid *pid;
> > + int count;
> > +};
> > +
> > +static void l2cap_chan_by_pid(struct l2cap_chan *chan, void *data)
> > +{
> > + struct l2cap_chan_data *d = data;
> > +
> > + if (chan == d->chan)
> > + return;
> > +
> > + /* Only count deferred channels with the same PID/PSM */
> > + if (d->pid != chan->ops->get_peer_pid(chan) ||
> > + !test_bit(FLAG_DEFER_SETUP, &chan->flags) ||
> > + chan->psm != d->chan->psm || chan->ident ||
> > + chan->state != BT_CONNECT)
> > + return;
> > +
> > + d->count++;
> > +}
> > +
> > int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid,
> > bdaddr_t *dst, u8 dst_type)
> > {
> > @@ -7813,6 +7907,22 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid,
> > goto done;
> > }
> >
> > + if (chan->mode == L2CAP_MODE_EXT_FLOWCTL) {
> > + struct l2cap_chan_data data;
> > +
> > + data.chan = chan;
> > + data.pid = chan->ops->get_peer_pid(chan);
> > + data.count = 0;
> > +
> > + l2cap_chan_list(conn, l2cap_chan_by_pid, &data);
> > + /* Check if there isn't too many channels being connected */
> > + if (!(data.count < L2CAP_ECRED_CONN_SCID_MAX - 1)) {
> > + hci_conn_drop(hcon);
> > + err = -EPROTO;
> > + goto done;
> > + }
> > + }
> > +
> > mutex_lock(&conn->chan_lock);
> > l2cap_chan_lock(chan);
> >
> > diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
> > index 40fb10b591bd..e43a90e05972 100644
> > --- a/net/bluetooth/l2cap_sock.c
> > +++ b/net/bluetooth/l2cap_sock.c
> > @@ -549,11 +549,6 @@ static int l2cap_sock_getsockopt(struct socket *sock, int level, int optname,
> > break;
> >
> > case BT_DEFER_SETUP:
> > - if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
> > - err = -EINVAL;
> > - break;
> > - }
> > -
>
> I removing this really a good idea. I think it is not really so bad to force at least BT_BOUND so that a local controller has been at least somehow selected. Just doing setsockopt(DEFER_SETUP) and then connect() seems weird. Let us force the application to at least bind the local controller for this specific usage. They can still bind with BDADDR_ANY, but that gives us a bit cleaner state handling.
Right, for some odd reason I remember this check being specific for
listen only but in fact it should work with l2cap-tester as it does
bind before doing BT_DEFER_SETUP.
>
> > if (put_user(test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags),
> > (u32 __user *) optval))
> > err = -EFAULT;
> > @@ -1504,6 +1499,13 @@ static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan)
> > return sk->sk_sndtimeo;
> > }
> >
> > +static struct pid *l2cap_sock_get_peer_pid_cb(struct l2cap_chan *chan)
> > +{
> > + struct sock *sk = chan->data;
> > +
> > + return sk->sk_peer_pid;
> > +}
> > +
> > static void l2cap_sock_suspend_cb(struct l2cap_chan *chan)
> > {
> > struct sock *sk = chan->data;
> > @@ -1525,6 +1527,7 @@ static const struct l2cap_ops l2cap_chan_ops = {
> > .suspend = l2cap_sock_suspend_cb,
> > .set_shutdown = l2cap_sock_set_shutdown_cb,
> > .get_sndtimeo = l2cap_sock_get_sndtimeo_cb,
> > + .get_peer_pid = l2cap_sock_get_peer_pid_cb,
> > .alloc_skb = l2cap_sock_alloc_skb_cb,
> > };
>
> Regards
>
> Marcel
>
--
Luiz Augusto von Dentz
