On 28. 02. 23, 7:29, D. Starke wrote:
From: Daniel Starke <daniel.starke@xxxxxxxxxxx>
Parameter negotiation has been introduced with
commit 92f1f0c3290d ("tty: n_gsm: add parameter negotiation support")
However, means to set individual parameters per DLCI are not yet
implemented. Furthermore, it is currently not possible to keep a DLCI half
open until the user application sets the right parameters for it. This is
required to allow a user application to set its specific parameters before
the underlying link is established. Otherwise, the link is opened and
re-established right afterwards if the user application sets incompatible
parameters. This may be an unexpected behavior for the peer.
Add parameter 'wait_config' to 'gsm_config' to support setups where the
DLCI specific user application sets its specific parameters after open()
and before the link gets fully established. Setting this to zero disables
the user application specific DLCI configuration option.
Add the ioctls 'GSMIOC_GETCONF_DLCI' and 'GSMIOC_SETCONF_DLCI' for the
ldisc and virtual ttys. This gets/sets the DLCI specific parameters and may
trigger a reconnect of the DLCI if incompatible values have been set. Only
the parameters for the DLCI associated with the virtual tty can be set or
retrieved if called on these.
Add remark within the documentation to introduce the new ioctls.
Signed-off-by: Daniel Starke <daniel.starke@xxxxxxxxxxx>
...
@@ -2453,6 +2476,128 @@ static void gsm_kick_timer(struct timer_list *t)
pr_info("%s TX queue stalled\n", __func__);
}
+/**
+ * gsm_dlci_copy_config_values - copy DLCI configuration
+ * @dlci: source DLCI
+ * @dc: configuration structure to fill
+ */
+static void gsm_dlci_copy_config_values(struct gsm_dlci *dlci, struct gsm_dlci_config *dc)
+{
+ memset(dc, 0, sizeof(*dc));
+ dc->channel = (u32)dlci->addr;
+ dc->adaption = (u32)dlci->adaption;
+ dc->mtu = (u32)dlci->mtu;
+ dc->priority = (u32)dlci->prio;
+ if (dlci->ftype == UIH)
+ dc->i = 1;
+ else
+ dc->i = 2;
+ dc->k = (u32)dlci->k;
Why all those casts?
+}
+
+/**
+ * gsm_dlci_config - configure DLCI from configuration
+ * @dlci: DLCI to configure
+ * @dc: DLCI configuration
+ * @open: open DLCI after configuration?
+ */
+static int gsm_dlci_config(struct gsm_dlci *dlci, struct gsm_dlci_config *dc, int open)
+{
+ struct gsm_mux *gsm;
+ bool need_restart = false;
+ bool need_open = false;
+ unsigned int i;
+
+ /*
+ * Check that userspace doesn't put stuff in here to prevent breakages
+ * in the future.
+ */
+ for (i = 0; i < ARRAY_SIZE(dc->reserved); i++)
+ if (dc->reserved[i])
+ return -EINVAL;
+
+ if (!dlci)
+ return -EINVAL;
+ gsm = dlci->gsm;
+
+ /* Stuff we don't support yet - I frame transport */
+ if (dc->adaption != 1 && dc->adaption != 2)
+ return -EOPNOTSUPP;
+ if (dc->mtu > MAX_MTU || dc->mtu < MIN_MTU || (unsigned int)dc->mtu > gsm->mru)
+ return -EINVAL;
+ if (dc->priority >= 64)
+ return -EINVAL;
+ if (dc->i == 0 || dc->i > 2) /* UIH and UI only */
+ return -EINVAL;
+ if (dc->k > 7)
+ return -EINVAL;
+
+ /*
+ * See what is needed for reconfiguration
+ */
+ /* Framing fields */
+ if ((int)dc->adaption != dlci->adaption)
+ need_restart = true;
+ if ((unsigned int)dc->mtu != dlci->mtu)
+ need_restart = true;
+ if ((u8)dc->i != dlci->ftype)
+ need_restart = true;
+ /* Requires care */
+ if ((u8)dc->priority != (u32)dlci->prio)
+ need_restart = true;
And here.
+
+ if ((open && gsm->wait_config) || need_restart)
+ need_open = true;
+ if (dlci->state == DLCI_WAITING_CONFIG) {
+ need_restart = false;
+ need_open = true;
+ }
+
+ /*
+ * Close down what is needed, restart and initiate the new
+ * configuration.
+ */
+ if (need_restart) {
+ gsm_dlci_begin_close(dlci);
+ wait_event_interruptible(gsm->event, dlci->state == DLCI_CLOSED);
+ if (signal_pending(current))
+ return -EINTR;
+ }
+ /*
+ * Setup the new configuration values
+ */
+ dlci->adaption = (int)dc->adaption;
+
+ if (dlci->mtu)
dc->mtu?
+ dlci->mtu = (unsigned int)dc->mtu;
+ else
+ dlci->mtu = gsm->mtu;
+
+ if (dc->priority)
+ dlci->prio = (u8)dc->priority;
+ else
+ dlci->prio = roundup(dlci->addr + 1, 8) - 1;
+
+ if (dc->i == 1)
+ dlci->ftype = UIH;
+ else if (dc->i == 2)
+ dlci->ftype = UI;
+
+ if (dc->k)
+ dlci->k = (u8)dc->k;
+ else
+ dlci->k = gsm->k;
+
+ if (need_open) {
+ if (gsm->initiator)
+ gsm_dlci_begin_open(dlci);
+ else
+ gsm_dlci_set_opening(dlci);
+ }
+
+ return 0;
+}
+
/*
* Allocate/Free DLCI channels
*/
--
js
suse labs
