--- /dev/null
+/* $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 = {
+ &isdn_x25iface_proto_new,
+ &isdn_x25iface_proto_del,
+ &isdn_x25iface_proto_restart,
+ &isdn_x25iface_proto_close,
+ &isdn_x25iface_xmit,
+ &isdn_x25iface_receive,
+ &isdn_x25iface_connect_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(skb, 1)) = 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(skb, 1)) = 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);
+ cprot->net_dev->trans_start = jiffies;
+ 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;
+}
Code Review / kvmfornfv.git / blobdiff