patch-2.3.47 linux/net/bridge/br_stp_bpdu.c

• Lines: 192
• Date: Sun Feb 20 10:41:18 2000
• Orig file: v2.3.46/linux/net/bridge/br_stp_bpdu.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.46/linux/net/bridge/br_stp_bpdu.c linux/net/bridge/br_stp_bpdu.c
@@ -0,0 +1,191 @@
+/*
+ *	Spanning tree protocol; BPDU handling
+ *	Linux ethernet bridge
+ *
+ *	Authors:
+ *	Lennert Buytenhek		<buytenh@gnu.org>
+ *
+ *	$Id: br_stp_bpdu.c,v 1.1 2000/02/18 16:47:13 davem Exp $
+ *
+ *	This program 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/if_bridge.h>
+#include "br_private.h"
+#include "br_private_stp.h"
+
+#define JIFFIES_TO_TICKS(j) (((j) << 8) / HZ)
+#define TICKS_TO_JIFFIES(j) (((j) * HZ) >> 8)
+
+static void br_send_bpdu(struct net_bridge_port *p, unsigned char *data, int length)
+{
+	struct net_device *dev;
+	struct sk_buff *skb;
+	int size;
+
+	if (!p->br->stp_enabled)
+		return;
+
+	size = length + 2*ETH_ALEN + 2;
+	if (size < 60)
+		size = 60;
+
+	dev = p->dev;
+
+	if ((skb = dev_alloc_skb(size)) == NULL) {
+		printk(KERN_INFO "br: memory squeeze!\n");
+		return;
+	}
+
+	skb->dev = dev;
+	skb->mac.raw = skb_put(skb, size);
+	memcpy(skb->mac.raw, bridge_ula, ETH_ALEN);
+	memcpy(skb->mac.raw+ETH_ALEN, dev->dev_addr, ETH_ALEN);
+	skb->mac.raw[2*ETH_ALEN] = 0;
+	skb->mac.raw[2*ETH_ALEN+1] = length;
+	skb->nh.raw = skb->mac.raw + 2*ETH_ALEN + 2;
+	memcpy(skb->nh.raw, data, length);
+	memset(skb->nh.raw + length, 0xa5, size - length - 2*ETH_ALEN - 2);
+
+	dev_queue_xmit(skb);
+}
+
+static __inline__ void br_set_ticks(unsigned char *dest, int jiff)
+{
+	__u16 ticks;
+
+	ticks = JIFFIES_TO_TICKS(jiff);
+	dest[0] = (ticks >> 8) & 0xFF;
+	dest[1] = ticks & 0xFF;
+}
+
+static __inline__ int br_get_ticks(unsigned char *dest)
+{
+	return TICKS_TO_JIFFIES((dest[0] << 8) | dest[1]);
+}
+
+/* called under bridge lock */
+void br_send_config_bpdu(struct net_bridge_port *p, struct br_config_bpdu *bpdu)
+{
+	unsigned char buf[38];
+
+	buf[0] = 0x42;
+	buf[1] = 0x42;
+	buf[2] = 0x03;
+	buf[3] = 0;
+	buf[4] = 0;
+	buf[5] = 0;
+	buf[6] = BPDU_TYPE_CONFIG;
+	buf[7] = (bpdu->topology_change ? 0x01 : 0) |
+		(bpdu->topology_change_ack ? 0x80 : 0);
+	buf[8] = bpdu->root.prio[0];
+	buf[9] = bpdu->root.prio[1];
+	buf[10] = bpdu->root.addr[0];
+	buf[11] = bpdu->root.addr[1];
+	buf[12] = bpdu->root.addr[2];
+	buf[13] = bpdu->root.addr[3];
+	buf[14] = bpdu->root.addr[4];
+	buf[15] = bpdu->root.addr[5];
+	buf[16] = (bpdu->root_path_cost >> 24) & 0xFF;
+	buf[17] = (bpdu->root_path_cost >> 16) & 0xFF;
+	buf[18] = (bpdu->root_path_cost >> 8) & 0xFF;
+	buf[19] = bpdu->root_path_cost & 0xFF;
+	buf[20] = bpdu->bridge_id.prio[0];
+	buf[21] = bpdu->bridge_id.prio[1];
+	buf[22] = bpdu->bridge_id.addr[0];
+	buf[23] = bpdu->bridge_id.addr[1];
+	buf[24] = bpdu->bridge_id.addr[2];
+	buf[25] = bpdu->bridge_id.addr[3];
+	buf[26] = bpdu->bridge_id.addr[4];
+	buf[27] = bpdu->bridge_id.addr[5];
+	buf[28] = (bpdu->port_id >> 8) & 0xFF;
+	buf[29] = bpdu->port_id & 0xFF;
+
+	br_set_ticks(buf+30, bpdu->message_age);
+	br_set_ticks(buf+32, bpdu->max_age);
+	br_set_ticks(buf+34, bpdu->hello_time);
+	br_set_ticks(buf+36, bpdu->forward_delay);
+
+	br_send_bpdu(p, buf, 38);
+}
+
+/* called under bridge lock */
+void br_send_tcn_bpdu(struct net_bridge_port *p)
+{
+	unsigned char buf[7];
+
+	buf[0] = 0x42;
+	buf[1] = 0x42;
+	buf[2] = 0x03;
+	buf[3] = 0;
+	buf[4] = 0;
+	buf[5] = 0;
+	buf[6] = BPDU_TYPE_TCN;
+	br_send_bpdu(p, buf, 7);
+}
+
+static unsigned char header[6] = {0x42, 0x42, 0x03, 0x00, 0x00, 0x00};
+
+/* called under bridge lock */
+void br_stp_handle_bpdu(struct sk_buff *skb)
+{
+	unsigned char *buf;
+	struct net_bridge_port *p;
+
+	buf = skb->mac.raw + 14;
+	p = skb->dev->br_port;
+	if (!p->br->stp_enabled || memcmp(buf, header, 6)) {
+		kfree_skb(skb);
+		return;
+	}
+
+	if (buf[6] == BPDU_TYPE_CONFIG) {
+		struct br_config_bpdu bpdu;
+
+		bpdu.topology_change = (buf[7] & 0x01) ? 1 : 0;
+		bpdu.topology_change_ack = (buf[7] & 0x80) ? 1 : 0;
+		bpdu.root.prio[0] = buf[8];
+		bpdu.root.prio[1] = buf[9];
+		bpdu.root.addr[0] = buf[10];
+		bpdu.root.addr[1] = buf[11];
+		bpdu.root.addr[2] = buf[12];
+		bpdu.root.addr[3] = buf[13];
+		bpdu.root.addr[4] = buf[14];
+		bpdu.root.addr[5] = buf[15];
+		bpdu.root_path_cost =
+			(buf[16] << 24) |
+			(buf[17] << 16) |
+			(buf[18] << 8) |
+			buf[19];
+		bpdu.bridge_id.prio[0] = buf[20];
+		bpdu.bridge_id.prio[1] = buf[21];
+		bpdu.bridge_id.addr[0] = buf[22];
+		bpdu.bridge_id.addr[1] = buf[23];
+		bpdu.bridge_id.addr[2] = buf[24];
+		bpdu.bridge_id.addr[3] = buf[25];
+		bpdu.bridge_id.addr[4] = buf[26];
+		bpdu.bridge_id.addr[5] = buf[27];
+		bpdu.port_id = (buf[28] << 8) | buf[29];
+
+		bpdu.message_age = br_get_ticks(buf+30);
+		bpdu.max_age = br_get_ticks(buf+32);
+		bpdu.hello_time = br_get_ticks(buf+34);
+		bpdu.forward_delay = br_get_ticks(buf+36);
+
+		kfree_skb(skb);
+		br_received_config_bpdu(p, &bpdu);
+		return;
+	}
+
+	if (buf[6] == BPDU_TYPE_TCN) {
+		br_received_tcn_bpdu(p);
+		kfree_skb(skb);
+		return;
+	}
+
+	kfree_skb(skb);
+}