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Diffstat (limited to 'net/x25/x25_dev.c')
-rw-r--r--net/x25/x25_dev.c232
1 files changed, 232 insertions, 0 deletions
diff --git a/net/x25/x25_dev.c b/net/x25/x25_dev.c
new file mode 100644
index 000000000..39231237e
--- /dev/null
+++ b/net/x25/x25_dev.c
@@ -0,0 +1,232 @@
+/*
+ * X.25 Packet Layer release 002
+ *
+ * This is ALPHA test software. This code may break your machine, randomly fail to work with new
+ * releases, misbehave and/or generally screw up. It might even work.
+ *
+ * This code REQUIRES 2.1.15 or higher
+ *
+ * This module:
+ * This module is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * History
+ * X.25 001 Jonathan Naylor Started coding.
+ * 2000-09-04 Henner Eisen Prevent freeing a dangling skb.
+ */
+
+#define pr_fmt(fmt) "X25: " fmt
+
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <linux/if_arp.h>
+#include <net/x25.h>
+#include <net/x25device.h>
+
+static int x25_receive_data(struct sk_buff *skb, struct x25_neigh *nb)
+{
+ struct sock *sk;
+ unsigned short frametype;
+ unsigned int lci;
+
+ if (!pskb_may_pull(skb, X25_STD_MIN_LEN))
+ return 0;
+
+ frametype = skb->data[2];
+ lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
+
+ /*
+ * LCI of zero is always for us, and its always a link control
+ * frame.
+ */
+ if (lci == 0) {
+ x25_link_control(skb, nb, frametype);
+ return 0;
+ }
+
+ /*
+ * Find an existing socket.
+ */
+ if ((sk = x25_find_socket(lci, nb)) != NULL) {
+ int queued = 1;
+
+ skb_reset_transport_header(skb);
+ bh_lock_sock(sk);
+ if (!sock_owned_by_user(sk)) {
+ queued = x25_process_rx_frame(sk, skb);
+ } else {
+ queued = !sk_add_backlog(sk, skb, sk->sk_rcvbuf);
+ }
+ bh_unlock_sock(sk);
+ sock_put(sk);
+ return queued;
+ }
+
+ /*
+ * Is is a Call Request ? if so process it.
+ */
+ if (frametype == X25_CALL_REQUEST)
+ return x25_rx_call_request(skb, nb, lci);
+
+ /*
+ * Its not a Call Request, nor is it a control frame.
+ * Can we forward it?
+ */
+
+ if (x25_forward_data(lci, nb, skb)) {
+ if (frametype == X25_CLEAR_CONFIRMATION) {
+ x25_clear_forward_by_lci(lci);
+ }
+ kfree_skb(skb);
+ return 1;
+ }
+
+/*
+ x25_transmit_clear_request(nb, lci, 0x0D);
+*/
+
+ if (frametype != X25_CLEAR_CONFIRMATION)
+ pr_debug("x25_receive_data(): unknown frame type %2x\n",frametype);
+
+ return 0;
+}
+
+int x25_lapb_receive_frame(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *ptype, struct net_device *orig_dev)
+{
+ struct sk_buff *nskb;
+ struct x25_neigh *nb;
+
+ if (!net_eq(dev_net(dev), &init_net))
+ goto drop;
+
+ nskb = skb_copy(skb, GFP_ATOMIC);
+ if (!nskb)
+ goto drop;
+ kfree_skb(skb);
+ skb = nskb;
+
+ /*
+ * Packet received from unrecognised device, throw it away.
+ */
+ nb = x25_get_neigh(dev);
+ if (!nb) {
+ pr_debug("unknown neighbour - %s\n", dev->name);
+ goto drop;
+ }
+
+ if (!pskb_may_pull(skb, 1))
+ return 0;
+
+ switch (skb->data[0]) {
+
+ case X25_IFACE_DATA:
+ skb_pull(skb, 1);
+ if (x25_receive_data(skb, nb)) {
+ x25_neigh_put(nb);
+ goto out;
+ }
+ break;
+
+ case X25_IFACE_CONNECT:
+ x25_link_established(nb);
+ break;
+
+ case X25_IFACE_DISCONNECT:
+ x25_link_terminated(nb);
+ break;
+ }
+ x25_neigh_put(nb);
+drop:
+ kfree_skb(skb);
+out:
+ return 0;
+}
+
+void x25_establish_link(struct x25_neigh *nb)
+{
+ struct sk_buff *skb;
+ unsigned char *ptr;
+
+ switch (nb->dev->type) {
+ case ARPHRD_X25:
+ if ((skb = alloc_skb(1, GFP_ATOMIC)) == NULL) {
+ pr_err("x25_dev: out of memory\n");
+ return;
+ }
+ ptr = skb_put(skb, 1);
+ *ptr = X25_IFACE_CONNECT;
+ break;
+
+#if IS_ENABLED(CONFIG_LLC)
+ case ARPHRD_ETHER:
+ return;
+#endif
+ default:
+ return;
+ }
+
+ skb->protocol = htons(ETH_P_X25);
+ skb->dev = nb->dev;
+
+ dev_queue_xmit(skb);
+}
+
+void x25_terminate_link(struct x25_neigh *nb)
+{
+ struct sk_buff *skb;
+ unsigned char *ptr;
+
+#if IS_ENABLED(CONFIG_LLC)
+ if (nb->dev->type == ARPHRD_ETHER)
+ return;
+#endif
+ if (nb->dev->type != ARPHRD_X25)
+ return;
+
+ skb = alloc_skb(1, GFP_ATOMIC);
+ if (!skb) {
+ pr_err("x25_dev: out of memory\n");
+ return;
+ }
+
+ ptr = skb_put(skb, 1);
+ *ptr = X25_IFACE_DISCONNECT;
+
+ skb->protocol = htons(ETH_P_X25);
+ skb->dev = nb->dev;
+ dev_queue_xmit(skb);
+}
+
+void x25_send_frame(struct sk_buff *skb, struct x25_neigh *nb)
+{
+ unsigned char *dptr;
+
+ skb_reset_network_header(skb);
+
+ switch (nb->dev->type) {
+ case ARPHRD_X25:
+ dptr = skb_push(skb, 1);
+ *dptr = X25_IFACE_DATA;
+ break;
+
+#if IS_ENABLED(CONFIG_LLC)
+ case ARPHRD_ETHER:
+ kfree_skb(skb);
+ return;
+#endif
+ default:
+ kfree_skb(skb);
+ return;
+ }
+
+ skb->protocol = htons(ETH_P_X25);
+ skb->dev = nb->dev;
+
+ dev_queue_xmit(skb);
+}