1 files changed, 133 insertions, 0 deletions
diff --git a/net/rose/rose_loopback.c b/net/rose/rose_loopback.c
new file mode 100644
index 000000000..036d92c0a
--- /dev/null
+++ b/net/rose/rose_loopback.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *
+ * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
+ */
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/socket.h>
+#include <linux/timer.h>
+#include <net/ax25.h>
+#include <linux/skbuff.h>
+#include <net/rose.h>
+#include <linux/init.h>
+
+static struct sk_buff_head loopback_queue;
+#define ROSE_LOOPBACK_LIMIT 1000
+static struct timer_list loopback_timer;
+
+static void rose_set_loopback_timer(void);
+static void rose_loopback_timer(struct timer_list *unused);
+
+void rose_loopback_init(void)
+{
+	skb_queue_head_init(&loopback_queue);
+
+	timer_setup(&loopback_timer, rose_loopback_timer, 0);
+}
+
+static int rose_loopback_running(void)
+{
+	return timer_pending(&loopback_timer);
+}
+
+int rose_loopback_queue(struct sk_buff *skb, struct rose_neigh *neigh)
+{
+	struct sk_buff *skbn = NULL;
+
+	if (skb_queue_len(&loopback_queue) < ROSE_LOOPBACK_LIMIT)
+		skbn = skb_clone(skb, GFP_ATOMIC);
+
+	if (skbn) {
+		consume_skb(skb);
+		skb_queue_tail(&loopback_queue, skbn);
+
+		if (!rose_loopback_running())
+			rose_set_loopback_timer();
+	} else {
+		kfree_skb(skb);
+	}
+
+	return 1;
+}
+
+static void rose_set_loopback_timer(void)
+{
+	mod_timer(&loopback_timer, jiffies + 10);
+}
+
+static void rose_loopback_timer(struct timer_list *unused)
+{
+	struct sk_buff *skb;
+	struct net_device *dev;
+	rose_address *dest;
+	struct sock *sk;
+	unsigned short frametype;
+	unsigned int lci_i, lci_o;
+	int count;
+
+	for (count = 0; count < ROSE_LOOPBACK_LIMIT; count++) {
+		skb = skb_dequeue(&loopback_queue);
+		if (!skb)
+			return;
+		if (skb->len < ROSE_MIN_LEN) {
+			kfree_skb(skb);
+			continue;
+		}
+		lci_i     = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
+		frametype = skb->data[2];
+		if (frametype == ROSE_CALL_REQUEST &&
+		    (skb->len <= ROSE_CALL_REQ_FACILITIES_OFF ||
+		     skb->data[ROSE_CALL_REQ_ADDR_LEN_OFF] !=
+		     ROSE_CALL_REQ_ADDR_LEN_VAL)) {
+			kfree_skb(skb);
+			continue;
+		}
+		dest      = (rose_address *)(skb->data + ROSE_CALL_REQ_DEST_ADDR_OFF);
+		lci_o     = ROSE_DEFAULT_MAXVC + 1 - lci_i;
+
+		skb_reset_transport_header(skb);
+
+		sk = rose_find_socket(lci_o, rose_loopback_neigh);
+		if (sk) {
+			if (rose_process_rx_frame(sk, skb) == 0)
+				kfree_skb(skb);
+			continue;
+		}
+
+		if (frametype == ROSE_CALL_REQUEST) {
+			if (!rose_loopback_neigh->dev &&
+			    !rose_loopback_neigh->loopback) {
+				kfree_skb(skb);
+				continue;
+			}
+
+			dev = rose_dev_get(dest);
+			if (!dev) {
+				kfree_skb(skb);
+				continue;
+			}
+
+			if (rose_rx_call_request(skb, dev, rose_loopback_neigh, lci_o) == 0) {
+				dev_put(dev);
+				kfree_skb(skb);
+			}
+		} else {
+			kfree_skb(skb);
+		}
+	}
+	if (!skb_queue_empty(&loopback_queue))
+		mod_timer(&loopback_timer, jiffies + 1);
+}
+
+void __exit rose_loopback_clear(void)
+{
+	struct sk_buff *skb;
+
+	del_timer(&loopback_timer);
+
+	while ((skb = skb_dequeue(&loopback_queue)) != NULL) {
+		skb->sk = NULL;
+		kfree_skb(skb);
+	}
+}