Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 332 insertions, 0 deletions

diff --git a/drivers/isdn/i4l/isdn_x25iface.c b/drivers/isdn/i4l/isdn_x25iface.c
new file mode 100644
index 000000000..48bfbcb4a
--- /dev/null
+++ b/drivers/isdn/i4l/isdn_x25iface.c
@@ -0,0 +1,332 @@
+/* $Id: isdn_x25iface.c,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $
+ *
+ * Linux ISDN subsystem, X.25 related functions
+ *
+ * This software may be used and distributed according to the terms
+ * of the GNU General Public License, incorporated herein by reference.
+ *
+ * stuff needed to support the Linux X.25 PLP code on top of devices that
+ * can provide a lab_b service using the concap_proto mechanism.
+ * This module supports a network interface which provides lapb_sematics
+ * -- as defined in Documentation/networking/x25-iface.txt -- to
+ * the upper layer and assumes that the lower layer provides a reliable
+ * data link service by means of the concap_device_ops callbacks.
+ *
+ * Only protocol specific stuff goes here. Device specific stuff
+ * goes to another -- device related -- concap_proto support source file.
+ *
+ */
+
+/* #include <linux/isdn.h> */
+#include <linux/netdevice.h>
+#include <linux/concap.h>
+#include <linux/slab.h>
+#include <linux/wanrouter.h>
+#include <net/x25device.h>
+#include "isdn_x25iface.h"
+
+/* for debugging messages not to cause an oops when device pointer is NULL*/
+#define MY_DEVNAME(dev)  ((dev) ? (dev)->name : "DEVICE UNSPECIFIED")
+
+
+typedef struct isdn_x25iface_proto_data {
+	int magic;
+	enum wan_states state;
+	/* Private stuff, not to be accessed via proto_data. We provide the
+	   other storage for the concap_proto instance here as well,
+	   enabling us to allocate both with just one kmalloc(): */
+	struct concap_proto priv;
+} ix25_pdata_t;
+
+
+
+/* is now in header file (extern): struct concap_proto * isdn_x25iface_proto_new(void); */
+static void isdn_x25iface_proto_del(struct concap_proto *);
+static int isdn_x25iface_proto_close(struct concap_proto *);
+static int isdn_x25iface_proto_restart(struct concap_proto *,
+				       struct net_device *,
+				       struct concap_device_ops *);
+static int isdn_x25iface_xmit(struct concap_proto *, struct sk_buff *);
+static int isdn_x25iface_receive(struct concap_proto *, struct sk_buff *);
+static int isdn_x25iface_connect_ind(struct concap_proto *);
+static int isdn_x25iface_disconn_ind(struct concap_proto *);
+
+
+static struct concap_proto_ops ix25_pops = {
+	.proto_new = &isdn_x25iface_proto_new,
+	.proto_del = &isdn_x25iface_proto_del,
+	.restart = &isdn_x25iface_proto_restart,
+	.close = &isdn_x25iface_proto_close,
+	.encap_and_xmit = &isdn_x25iface_xmit,
+	.data_ind = &isdn_x25iface_receive,
+	.connect_ind = &isdn_x25iface_connect_ind,
+	.disconn_ind = &isdn_x25iface_disconn_ind
+};
+
+/* error message helper function */
+static void illegal_state_warn(unsigned state, unsigned char firstbyte)
+{
+	printk(KERN_WARNING "isdn_x25iface: firstbyte %x illegal in"
+	       "current state %d\n", firstbyte, state);
+}
+
+/* check protocol data field for consistency */
+static int pdata_is_bad(ix25_pdata_t *pda) {
+
+	if (pda  &&  pda->magic == ISDN_X25IFACE_MAGIC) return 0;
+	printk(KERN_WARNING
+	       "isdn_x25iface_xxx: illegal pointer to proto data\n");
+	return 1;
+}
+
+/* create a new x25 interface protocol instance
+ */
+struct concap_proto *isdn_x25iface_proto_new(void)
+{
+	ix25_pdata_t *tmp = kmalloc(sizeof(ix25_pdata_t), GFP_KERNEL);
+	IX25DEBUG("isdn_x25iface_proto_new\n");
+	if (tmp) {
+		tmp->magic = ISDN_X25IFACE_MAGIC;
+		tmp->state = WAN_UNCONFIGURED;
+		/* private data space used to hold the concap_proto data.
+		   Only to be accessed via the returned pointer */
+		spin_lock_init(&tmp->priv.lock);
+		tmp->priv.dops       = NULL;
+		tmp->priv.net_dev    = NULL;
+		tmp->priv.pops       = &ix25_pops;
+		tmp->priv.flags      = 0;
+		tmp->priv.proto_data = tmp;
+		return (&(tmp->priv));
+	}
+	return NULL;
+};
+
+/* close the x25iface encapsulation protocol
+ */
+static int isdn_x25iface_proto_close(struct concap_proto *cprot) {
+
+	ix25_pdata_t *tmp;
+	int ret = 0;
+	ulong flags;
+
+	if (!cprot) {
+		printk(KERN_ERR "isdn_x25iface_proto_close: "
+		       "invalid concap_proto pointer\n");
+		return -1;
+	}
+	IX25DEBUG("isdn_x25iface_proto_close %s \n", MY_DEVNAME(cprot->net_dev));
+	spin_lock_irqsave(&cprot->lock, flags);
+	cprot->dops    = NULL;
+	cprot->net_dev = NULL;
+	tmp = cprot->proto_data;
+	if (pdata_is_bad(tmp)) {
+		ret = -1;
+	} else {
+		tmp->state = WAN_UNCONFIGURED;
+	}
+	spin_unlock_irqrestore(&cprot->lock, flags);
+	return ret;
+}
+
+/* Delete the x25iface encapsulation protocol instance
+ */
+static void isdn_x25iface_proto_del(struct concap_proto *cprot) {
+
+	ix25_pdata_t *tmp;
+
+	IX25DEBUG("isdn_x25iface_proto_del \n");
+	if (!cprot) {
+		printk(KERN_ERR "isdn_x25iface_proto_del: "
+		       "concap_proto pointer is NULL\n");
+		return;
+	}
+	tmp = cprot->proto_data;
+	if (tmp == NULL) {
+		printk(KERN_ERR "isdn_x25iface_proto_del: inconsistent "
+		       "proto_data pointer (maybe already deleted?)\n");
+		return;
+	}
+	/* close if the protocol is still open */
+	if (cprot->dops) isdn_x25iface_proto_close(cprot);
+	/* freeing the storage should be sufficient now. But some additional
+	   settings might help to catch wild pointer bugs */
+	tmp->magic = 0;
+	cprot->proto_data = NULL;
+
+	kfree(tmp);
+	return;
+}
+
+/* (re-)initialize the data structures for x25iface encapsulation
+ */
+static int isdn_x25iface_proto_restart(struct concap_proto *cprot,
+				       struct net_device *ndev,
+				       struct concap_device_ops *dops)
+{
+	ix25_pdata_t *pda = cprot->proto_data;
+	ulong flags;
+
+	IX25DEBUG("isdn_x25iface_proto_restart %s \n", MY_DEVNAME(ndev));
+
+	if (pdata_is_bad(pda)) return -1;
+
+	if (!(dops && dops->data_req && dops->connect_req
+	      && dops->disconn_req)) {
+		printk(KERN_WARNING "isdn_x25iface_restart: required dops"
+		       " missing\n");
+		isdn_x25iface_proto_close(cprot);
+		return -1;
+	}
+	spin_lock_irqsave(&cprot->lock, flags);
+	cprot->net_dev = ndev;
+	cprot->pops = &ix25_pops;
+	cprot->dops = dops;
+	pda->state = WAN_DISCONNECTED;
+	spin_unlock_irqrestore(&cprot->lock, flags);
+	return 0;
+}
+
+/* deliver a dl_data frame received from i4l HL driver to the network layer
+ */
+static int isdn_x25iface_receive(struct concap_proto *cprot, struct sk_buff *skb)
+{
+	IX25DEBUG("isdn_x25iface_receive %s \n", MY_DEVNAME(cprot->net_dev));
+	if (((ix25_pdata_t *)(cprot->proto_data))
+	    ->state == WAN_CONNECTED) {
+		if (skb_push(skb, 1)) {
+			skb->data[0] = X25_IFACE_DATA;
+			skb->protocol = x25_type_trans(skb, cprot->net_dev);
+			netif_rx(skb);
+			return 0;
+		}
+	}
+	printk(KERN_WARNING "isdn_x25iface_receive %s: not connected, skb dropped\n", MY_DEVNAME(cprot->net_dev));
+	dev_kfree_skb(skb);
+	return -1;
+}
+
+/* a connection set up is indicated by lower layer
+ */
+static int isdn_x25iface_connect_ind(struct concap_proto *cprot)
+{
+	struct sk_buff *skb;
+	enum wan_states *state_p
+		= &(((ix25_pdata_t *)(cprot->proto_data))->state);
+	IX25DEBUG("isdn_x25iface_connect_ind %s \n"
+		  , MY_DEVNAME(cprot->net_dev));
+	if (*state_p == WAN_UNCONFIGURED) {
+		printk(KERN_WARNING
+		       "isdn_x25iface_connect_ind while unconfigured %s\n"
+		       , MY_DEVNAME(cprot->net_dev));
+		return -1;
+	}
+	*state_p = WAN_CONNECTED;
+
+	skb = dev_alloc_skb(1);
+	if (skb) {
+		skb_put_u8(skb, X25_IFACE_CONNECT);
+		skb->protocol = x25_type_trans(skb, cprot->net_dev);
+		netif_rx(skb);
+		return 0;
+	} else {
+		printk(KERN_WARNING "isdn_x25iface_connect_ind: "
+		       " out of memory -- disconnecting\n");
+		cprot->dops->disconn_req(cprot);
+		return -1;
+	}
+}
+
+/* a disconnect is indicated by lower layer
+ */
+static int isdn_x25iface_disconn_ind(struct concap_proto *cprot)
+{
+	struct sk_buff *skb;
+	enum wan_states *state_p
+		= &(((ix25_pdata_t *)(cprot->proto_data))->state);
+	IX25DEBUG("isdn_x25iface_disconn_ind %s \n", MY_DEVNAME(cprot->net_dev));
+	if (*state_p == WAN_UNCONFIGURED) {
+		printk(KERN_WARNING
+		       "isdn_x25iface_disconn_ind while unconfigured\n");
+		return -1;
+	}
+	if (!cprot->net_dev) return -1;
+	*state_p = WAN_DISCONNECTED;
+	skb = dev_alloc_skb(1);
+	if (skb) {
+		skb_put_u8(skb, X25_IFACE_DISCONNECT);
+		skb->protocol = x25_type_trans(skb, cprot->net_dev);
+		netif_rx(skb);
+		return 0;
+	} else {
+		printk(KERN_WARNING "isdn_x25iface_disconn_ind:"
+		       " out of memory\n");
+		return -1;
+	}
+}
+
+/* process a frame handed over to us from linux network layer. First byte
+   semantics as defined in Documentation/networking/x25-iface.txt
+*/
+static int isdn_x25iface_xmit(struct concap_proto *cprot, struct sk_buff *skb)
+{
+	unsigned char firstbyte = skb->data[0];
+	enum wan_states *state = &((ix25_pdata_t *)cprot->proto_data)->state;
+	int ret = 0;
+	IX25DEBUG("isdn_x25iface_xmit: %s first=%x state=%d\n",
+		  MY_DEVNAME(cprot->net_dev), firstbyte, *state);
+	switch (firstbyte) {
+	case X25_IFACE_DATA:
+		if (*state == WAN_CONNECTED) {
+			skb_pull(skb, 1);
+			netif_trans_update(cprot->net_dev);
+			ret = (cprot->dops->data_req(cprot, skb));
+			/* prepare for future retransmissions */
+			if (ret) skb_push(skb, 1);
+			return ret;
+		}
+		illegal_state_warn(*state, firstbyte);
+		break;
+	case X25_IFACE_CONNECT:
+		if (*state == WAN_DISCONNECTED) {
+			*state = WAN_CONNECTING;
+			ret = cprot->dops->connect_req(cprot);
+			if (ret) {
+				/* reset state and notify upper layer about
+				 * immidiatly failed attempts */
+				isdn_x25iface_disconn_ind(cprot);
+			}
+		} else {
+			illegal_state_warn(*state, firstbyte);
+		}
+		break;
+	case X25_IFACE_DISCONNECT:
+		switch (*state) {
+		case WAN_DISCONNECTED:
+			/* Should not happen. However, give upper layer a
+			   chance to recover from inconstistency  but don't
+			   trust the lower layer sending the disconn_confirm
+			   when already disconnected */
+			printk(KERN_WARNING "isdn_x25iface_xmit: disconnect "
+			       " requested while disconnected\n");
+			isdn_x25iface_disconn_ind(cprot);
+			break; /* prevent infinite loops */
+		case WAN_CONNECTING:
+		case WAN_CONNECTED:
+			*state = WAN_DISCONNECTED;
+			cprot->dops->disconn_req(cprot);
+			break;
+		default:
+			illegal_state_warn(*state, firstbyte);
+		}
+		break;
+	case X25_IFACE_PARAMS:
+		printk(KERN_WARNING "isdn_x25iface_xmit: setting of lapb"
+		       " options not yet supported\n");
+		break;
+	default:
+		printk(KERN_WARNING "isdn_x25iface_xmit: frame with illegal"
+		       " first byte %x ignored:\n", firstbyte);
+	}
+	dev_kfree_skb(skb);
+	return 0;
+}