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path: root/drivers/net/wan/hdlc_x25.c
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Diffstat (limited to 'drivers/net/wan/hdlc_x25.c')
-rw-r--r--drivers/net/wan/hdlc_x25.c384
1 files changed, 384 insertions, 0 deletions
diff --git a/drivers/net/wan/hdlc_x25.c b/drivers/net/wan/hdlc_x25.c
new file mode 100644
index 000000000..f72c92c24
--- /dev/null
+++ b/drivers/net/wan/hdlc_x25.c
@@ -0,0 +1,384 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Generic HDLC support routines for Linux
+ * X.25 support
+ *
+ * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
+ */
+
+#include <linux/errno.h>
+#include <linux/gfp.h>
+#include <linux/hdlc.h>
+#include <linux/if_arp.h>
+#include <linux/inetdevice.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/lapb.h>
+#include <linux/module.h>
+#include <linux/pkt_sched.h>
+#include <linux/poll.h>
+#include <linux/rtnetlink.h>
+#include <linux/skbuff.h>
+#include <net/x25device.h>
+
+struct x25_state {
+ x25_hdlc_proto settings;
+ bool up;
+ spinlock_t up_lock; /* Protects "up" */
+ struct sk_buff_head rx_queue;
+ struct tasklet_struct rx_tasklet;
+};
+
+static int x25_ioctl(struct net_device *dev, struct if_settings *ifs);
+
+static struct x25_state *state(hdlc_device *hdlc)
+{
+ return hdlc->state;
+}
+
+static void x25_rx_queue_kick(struct tasklet_struct *t)
+{
+ struct x25_state *x25st = from_tasklet(x25st, t, rx_tasklet);
+ struct sk_buff *skb = skb_dequeue(&x25st->rx_queue);
+
+ while (skb) {
+ netif_receive_skb_core(skb);
+ skb = skb_dequeue(&x25st->rx_queue);
+ }
+}
+
+/* These functions are callbacks called by LAPB layer */
+
+static void x25_connect_disconnect(struct net_device *dev, int reason, int code)
+{
+ struct x25_state *x25st = state(dev_to_hdlc(dev));
+ struct sk_buff *skb;
+ unsigned char *ptr;
+
+ skb = __dev_alloc_skb(1, GFP_ATOMIC | __GFP_NOMEMALLOC);
+ if (!skb)
+ return;
+
+ ptr = skb_put(skb, 1);
+ *ptr = code;
+
+ skb->protocol = x25_type_trans(skb, dev);
+
+ skb_queue_tail(&x25st->rx_queue, skb);
+ tasklet_schedule(&x25st->rx_tasklet);
+}
+
+static void x25_connected(struct net_device *dev, int reason)
+{
+ x25_connect_disconnect(dev, reason, X25_IFACE_CONNECT);
+}
+
+static void x25_disconnected(struct net_device *dev, int reason)
+{
+ x25_connect_disconnect(dev, reason, X25_IFACE_DISCONNECT);
+}
+
+static int x25_data_indication(struct net_device *dev, struct sk_buff *skb)
+{
+ struct x25_state *x25st = state(dev_to_hdlc(dev));
+ unsigned char *ptr;
+
+ if (skb_cow(skb, 1)) {
+ kfree_skb(skb);
+ return NET_RX_DROP;
+ }
+
+ skb_push(skb, 1);
+
+ ptr = skb->data;
+ *ptr = X25_IFACE_DATA;
+
+ skb->protocol = x25_type_trans(skb, dev);
+
+ skb_queue_tail(&x25st->rx_queue, skb);
+ tasklet_schedule(&x25st->rx_tasklet);
+ return NET_RX_SUCCESS;
+}
+
+static void x25_data_transmit(struct net_device *dev, struct sk_buff *skb)
+{
+ hdlc_device *hdlc = dev_to_hdlc(dev);
+
+ skb_reset_network_header(skb);
+ skb->protocol = hdlc_type_trans(skb, dev);
+
+ if (dev_nit_active(dev))
+ dev_queue_xmit_nit(skb, dev);
+
+ hdlc->xmit(skb, dev); /* Ignore return value :-( */
+}
+
+static netdev_tx_t x25_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ hdlc_device *hdlc = dev_to_hdlc(dev);
+ struct x25_state *x25st = state(hdlc);
+ int result;
+
+ /* There should be a pseudo header of 1 byte added by upper layers.
+ * Check to make sure it is there before reading it.
+ */
+ if (skb->len < 1) {
+ kfree_skb(skb);
+ return NETDEV_TX_OK;
+ }
+
+ spin_lock_bh(&x25st->up_lock);
+ if (!x25st->up) {
+ spin_unlock_bh(&x25st->up_lock);
+ kfree_skb(skb);
+ return NETDEV_TX_OK;
+ }
+
+ switch (skb->data[0]) {
+ case X25_IFACE_DATA: /* Data to be transmitted */
+ skb_pull(skb, 1);
+ result = lapb_data_request(dev, skb);
+ if (result != LAPB_OK)
+ dev_kfree_skb(skb);
+ spin_unlock_bh(&x25st->up_lock);
+ return NETDEV_TX_OK;
+
+ case X25_IFACE_CONNECT:
+ result = lapb_connect_request(dev);
+ if (result != LAPB_OK) {
+ if (result == LAPB_CONNECTED)
+ /* Send connect confirm. msg to level 3 */
+ x25_connected(dev, 0);
+ else
+ netdev_err(dev, "LAPB connect request failed, error code = %i\n",
+ result);
+ }
+ break;
+
+ case X25_IFACE_DISCONNECT:
+ result = lapb_disconnect_request(dev);
+ if (result != LAPB_OK) {
+ if (result == LAPB_NOTCONNECTED)
+ /* Send disconnect confirm. msg to level 3 */
+ x25_disconnected(dev, 0);
+ else
+ netdev_err(dev, "LAPB disconnect request failed, error code = %i\n",
+ result);
+ }
+ break;
+
+ default: /* to be defined */
+ break;
+ }
+
+ spin_unlock_bh(&x25st->up_lock);
+ dev_kfree_skb(skb);
+ return NETDEV_TX_OK;
+}
+
+static int x25_open(struct net_device *dev)
+{
+ static const struct lapb_register_struct cb = {
+ .connect_confirmation = x25_connected,
+ .connect_indication = x25_connected,
+ .disconnect_confirmation = x25_disconnected,
+ .disconnect_indication = x25_disconnected,
+ .data_indication = x25_data_indication,
+ .data_transmit = x25_data_transmit,
+ };
+ hdlc_device *hdlc = dev_to_hdlc(dev);
+ struct x25_state *x25st = state(hdlc);
+ struct lapb_parms_struct params;
+ int result;
+
+ result = lapb_register(dev, &cb);
+ if (result != LAPB_OK)
+ return -ENOMEM;
+
+ result = lapb_getparms(dev, &params);
+ if (result != LAPB_OK)
+ return -EINVAL;
+
+ if (state(hdlc)->settings.dce)
+ params.mode = params.mode | LAPB_DCE;
+
+ if (state(hdlc)->settings.modulo == 128)
+ params.mode = params.mode | LAPB_EXTENDED;
+
+ params.window = state(hdlc)->settings.window;
+ params.t1 = state(hdlc)->settings.t1;
+ params.t2 = state(hdlc)->settings.t2;
+ params.n2 = state(hdlc)->settings.n2;
+
+ result = lapb_setparms(dev, &params);
+ if (result != LAPB_OK)
+ return -EINVAL;
+
+ spin_lock_bh(&x25st->up_lock);
+ x25st->up = true;
+ spin_unlock_bh(&x25st->up_lock);
+
+ return 0;
+}
+
+static void x25_close(struct net_device *dev)
+{
+ hdlc_device *hdlc = dev_to_hdlc(dev);
+ struct x25_state *x25st = state(hdlc);
+
+ spin_lock_bh(&x25st->up_lock);
+ x25st->up = false;
+ spin_unlock_bh(&x25st->up_lock);
+
+ lapb_unregister(dev);
+ tasklet_kill(&x25st->rx_tasklet);
+}
+
+static int x25_rx(struct sk_buff *skb)
+{
+ struct net_device *dev = skb->dev;
+ hdlc_device *hdlc = dev_to_hdlc(dev);
+ struct x25_state *x25st = state(hdlc);
+
+ skb = skb_share_check(skb, GFP_ATOMIC);
+ if (!skb) {
+ dev->stats.rx_dropped++;
+ return NET_RX_DROP;
+ }
+
+ spin_lock_bh(&x25st->up_lock);
+ if (!x25st->up) {
+ spin_unlock_bh(&x25st->up_lock);
+ kfree_skb(skb);
+ dev->stats.rx_dropped++;
+ return NET_RX_DROP;
+ }
+
+ if (lapb_data_received(dev, skb) == LAPB_OK) {
+ spin_unlock_bh(&x25st->up_lock);
+ return NET_RX_SUCCESS;
+ }
+
+ spin_unlock_bh(&x25st->up_lock);
+ dev->stats.rx_errors++;
+ dev_kfree_skb_any(skb);
+ return NET_RX_DROP;
+}
+
+static struct hdlc_proto proto = {
+ .open = x25_open,
+ .close = x25_close,
+ .ioctl = x25_ioctl,
+ .netif_rx = x25_rx,
+ .xmit = x25_xmit,
+ .module = THIS_MODULE,
+};
+
+static int x25_ioctl(struct net_device *dev, struct if_settings *ifs)
+{
+ x25_hdlc_proto __user *x25_s = ifs->ifs_ifsu.x25;
+ const size_t size = sizeof(x25_hdlc_proto);
+ hdlc_device *hdlc = dev_to_hdlc(dev);
+ x25_hdlc_proto new_settings;
+ int result;
+
+ switch (ifs->type) {
+ case IF_GET_PROTO:
+ if (dev_to_hdlc(dev)->proto != &proto)
+ return -EINVAL;
+ ifs->type = IF_PROTO_X25;
+ if (ifs->size < size) {
+ ifs->size = size; /* data size wanted */
+ return -ENOBUFS;
+ }
+ if (copy_to_user(x25_s, &state(hdlc)->settings, size))
+ return -EFAULT;
+ return 0;
+
+ case IF_PROTO_X25:
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+
+ if (dev->flags & IFF_UP)
+ return -EBUSY;
+
+ /* backward compatibility */
+ if (ifs->size == 0) {
+ new_settings.dce = 0;
+ new_settings.modulo = 8;
+ new_settings.window = 7;
+ new_settings.t1 = 3;
+ new_settings.t2 = 1;
+ new_settings.n2 = 10;
+ } else {
+ if (copy_from_user(&new_settings, x25_s, size))
+ return -EFAULT;
+
+ if ((new_settings.dce != 0 &&
+ new_settings.dce != 1) ||
+ (new_settings.modulo != 8 &&
+ new_settings.modulo != 128) ||
+ new_settings.window < 1 ||
+ (new_settings.modulo == 8 &&
+ new_settings.window > 7) ||
+ (new_settings.modulo == 128 &&
+ new_settings.window > 127) ||
+ new_settings.t1 < 1 ||
+ new_settings.t1 > 255 ||
+ new_settings.t2 < 1 ||
+ new_settings.t2 > 255 ||
+ new_settings.n2 < 1 ||
+ new_settings.n2 > 255)
+ return -EINVAL;
+ }
+
+ result = hdlc->attach(dev, ENCODING_NRZ,
+ PARITY_CRC16_PR1_CCITT);
+ if (result)
+ return result;
+
+ result = attach_hdlc_protocol(dev, &proto,
+ sizeof(struct x25_state));
+ if (result)
+ return result;
+
+ memcpy(&state(hdlc)->settings, &new_settings, size);
+ state(hdlc)->up = false;
+ spin_lock_init(&state(hdlc)->up_lock);
+ skb_queue_head_init(&state(hdlc)->rx_queue);
+ tasklet_setup(&state(hdlc)->rx_tasklet, x25_rx_queue_kick);
+
+ /* There's no header_ops so hard_header_len should be 0. */
+ dev->hard_header_len = 0;
+ /* When transmitting data:
+ * first we'll remove a pseudo header of 1 byte,
+ * then we'll prepend an LAPB header of at most 3 bytes.
+ */
+ dev->needed_headroom = 3 - 1;
+
+ dev->type = ARPHRD_X25;
+ call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
+ netif_dormant_off(dev);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static int __init hdlc_x25_init(void)
+{
+ register_hdlc_protocol(&proto);
+ return 0;
+}
+
+static void __exit hdlc_x25_exit(void)
+{
+ unregister_hdlc_protocol(&proto);
+}
+
+module_init(hdlc_x25_init);
+module_exit(hdlc_x25_exit);
+
+MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
+MODULE_DESCRIPTION("X.25 protocol support for generic HDLC");
+MODULE_LICENSE("GPL v2");
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-01 06:00:03 +0000