1 files changed, 304 insertions, 0 deletions

diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
new file mode 100644
index 00000000..f4944963
--- /dev/null
+++ b/net/bridge/br_stp_if.c
@@ -0,0 +1,304 @@
+/*
+ *	Spanning tree protocol; interface code
+ *	Linux ethernet bridge
+ *
+ *	Authors:
+ *	Lennert Buytenhek		<buytenh@gnu.org>
+ *
+ *	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/kmod.h>
+#include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
+
+#include "br_private.h"
+#include "br_private_stp.h"
+
+
+/* Port id is composed of priority and port number.
+ * NB: some bits of priority are dropped to
+ *     make room for more ports.
+ */
+static inline port_id br_make_port_id(__u8 priority, __u16 port_no)
+{
+	return ((u16)priority << BR_PORT_BITS)
+		| (port_no & ((1<<BR_PORT_BITS)-1));
+}
+
+#define BR_MAX_PORT_PRIORITY ((u16)~0 >> BR_PORT_BITS)
+
+/* called under bridge lock */
+void br_init_port(struct net_bridge_port *p)
+{
+	p->port_id = br_make_port_id(p->priority, p->port_no);
+	br_become_designated_port(p);
+	p->state = BR_STATE_BLOCKING;
+	p->topology_change_ack = 0;
+	p->config_pending = 0;
+}
+
+/* called under bridge lock */
+void br_stp_enable_bridge(struct net_bridge *br)
+{
+	struct net_bridge_port *p;
+
+	spin_lock_bh(&br->lock);
+	mod_timer(&br->hello_timer, jiffies + br->hello_time);
+	mod_timer(&br->gc_timer, jiffies + HZ/10);
+
+	br_config_bpdu_generation(br);
+
+	list_for_each_entry(p, &br->port_list, list) {
+		if ((p->dev->flags & IFF_UP) && netif_carrier_ok(p->dev))
+			br_stp_enable_port(p);
+
+	}
+	spin_unlock_bh(&br->lock);
+}
+
+/* NO locks held */
+void br_stp_disable_bridge(struct net_bridge *br)
+{
+	struct net_bridge_port *p;
+
+	spin_lock_bh(&br->lock);
+	list_for_each_entry(p, &br->port_list, list) {
+		if (p->state != BR_STATE_DISABLED)
+			br_stp_disable_port(p);
+
+	}
+
+	br->topology_change = 0;
+	br->topology_change_detected = 0;
+	spin_unlock_bh(&br->lock);
+
+	del_timer_sync(&br->hello_timer);
+	del_timer_sync(&br->topology_change_timer);
+	del_timer_sync(&br->tcn_timer);
+	del_timer_sync(&br->gc_timer);
+}
+
+/* called under bridge lock */
+void br_stp_enable_port(struct net_bridge_port *p)
+{
+	br_init_port(p);
+	br_port_state_selection(p->br);
+	br_log_state(p);
+	br_ifinfo_notify(RTM_NEWLINK, p);
+}
+
+/* called under bridge lock */
+void br_stp_disable_port(struct net_bridge_port *p)
+{
+	struct net_bridge *br = p->br;
+	int wasroot;
+
+	wasroot = br_is_root_bridge(br);
+	br_become_designated_port(p);
+	p->state = BR_STATE_DISABLED;
+	p->topology_change_ack = 0;
+	p->config_pending = 0;
+
+	br_log_state(p);
+	br_ifinfo_notify(RTM_NEWLINK, p);
+
+	del_timer(&p->message_age_timer);
+	del_timer(&p->forward_delay_timer);
+	del_timer(&p->hold_timer);
+
+	br_fdb_delete_by_port(br, p, 0);
+	br_multicast_disable_port(p);
+
+	br_configuration_update(br);
+
+	br_port_state_selection(br);
+
+	if (br_is_root_bridge(br) && !wasroot)
+		br_become_root_bridge(br);
+}
+
+static void br_stp_start(struct net_bridge *br)
+{
+	int r;
+	char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
+	char *envp[] = { NULL };
+
+	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
+	if (r == 0) {
+		br->stp_enabled = BR_USER_STP;
+		br_debug(br, "userspace STP started\n");
+	} else {
+		br->stp_enabled = BR_KERNEL_STP;
+		br_debug(br, "using kernel STP\n");
+
+		/* To start timers on any ports left in blocking */
+		spin_lock_bh(&br->lock);
+		br_port_state_selection(br);
+		spin_unlock_bh(&br->lock);
+	}
+}
+
+static void br_stp_stop(struct net_bridge *br)
+{
+	int r;
+	char *argv[] = { BR_STP_PROG, br->dev->name, "stop", NULL };
+	char *envp[] = { NULL };
+
+	if (br->stp_enabled == BR_USER_STP) {
+		r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
+		br_info(br, "userspace STP stopped, return code %d\n", r);
+
+		/* To start timers on any ports left in blocking */
+		spin_lock_bh(&br->lock);
+		br_port_state_selection(br);
+		spin_unlock_bh(&br->lock);
+	}
+
+	br->stp_enabled = BR_NO_STP;
+}
+
+void br_stp_set_enabled(struct net_bridge *br, unsigned long val)
+{
+	ASSERT_RTNL();
+
+	if (val) {
+		if (br->stp_enabled == BR_NO_STP)
+			br_stp_start(br);
+	} else {
+		if (br->stp_enabled != BR_NO_STP)
+			br_stp_stop(br);
+	}
+}
+
+/* called under bridge lock */
+void br_stp_change_bridge_id(struct net_bridge *br, const unsigned char *addr)
+{
+	/* should be aligned on 2 bytes for compare_ether_addr() */
+	unsigned short oldaddr_aligned[ETH_ALEN >> 1];
+	unsigned char *oldaddr = (unsigned char *)oldaddr_aligned;
+	struct net_bridge_port *p;
+	int wasroot;
+
+	wasroot = br_is_root_bridge(br);
+
+	memcpy(oldaddr, br->bridge_id.addr, ETH_ALEN);
+	memcpy(br->bridge_id.addr, addr, ETH_ALEN);
+	memcpy(br->dev->dev_addr, addr, ETH_ALEN);
+
+	list_for_each_entry(p, &br->port_list, list) {
+		if (!compare_ether_addr(p->designated_bridge.addr, oldaddr))
+			memcpy(p->designated_bridge.addr, addr, ETH_ALEN);
+
+		if (!compare_ether_addr(p->designated_root.addr, oldaddr))
+			memcpy(p->designated_root.addr, addr, ETH_ALEN);
+
+	}
+
+	br_configuration_update(br);
+	br_port_state_selection(br);
+	if (br_is_root_bridge(br) && !wasroot)
+		br_become_root_bridge(br);
+}
+
+/* should be aligned on 2 bytes for compare_ether_addr() */
+static const unsigned short br_mac_zero_aligned[ETH_ALEN >> 1];
+
+/* called under bridge lock */
+bool br_stp_recalculate_bridge_id(struct net_bridge *br)
+{
+	const unsigned char *br_mac_zero =
+			(const unsigned char *)br_mac_zero_aligned;
+	const unsigned char *addr = br_mac_zero;
+	struct net_bridge_port *p;
+
+	/* user has chosen a value so keep it */
+	if (br->flags & BR_SET_MAC_ADDR)
+		return false;
+
+	list_for_each_entry(p, &br->port_list, list) {
+		if (addr == br_mac_zero ||
+		    memcmp(p->dev->dev_addr, addr, ETH_ALEN) < 0)
+			addr = p->dev->dev_addr;
+
+	}
+
+	if (compare_ether_addr(br->bridge_id.addr, addr) == 0)
+		return false;	/* no change */
+
+	br_stp_change_bridge_id(br, addr);
+	return true;
+}
+
+/* called under bridge lock */
+void br_stp_set_bridge_priority(struct net_bridge *br, u16 newprio)
+{
+	struct net_bridge_port *p;
+	int wasroot;
+
+	wasroot = br_is_root_bridge(br);
+
+	list_for_each_entry(p, &br->port_list, list) {
+		if (p->state != BR_STATE_DISABLED &&
+		    br_is_designated_port(p)) {
+			p->designated_bridge.prio[0] = (newprio >> 8) & 0xFF;
+			p->designated_bridge.prio[1] = newprio & 0xFF;
+		}
+
+	}
+
+	br->bridge_id.prio[0] = (newprio >> 8) & 0xFF;
+	br->bridge_id.prio[1] = newprio & 0xFF;
+	br_configuration_update(br);
+	br_port_state_selection(br);
+	if (br_is_root_bridge(br) && !wasroot)
+		br_become_root_bridge(br);
+}
+
+/* called under bridge lock */
+int br_stp_set_port_priority(struct net_bridge_port *p, unsigned long newprio)
+{
+	port_id new_port_id;
+
+	if (newprio > BR_MAX_PORT_PRIORITY)
+		return -ERANGE;
+
+	new_port_id = br_make_port_id(newprio, p->port_no);
+	if (br_is_designated_port(p))
+		p->designated_port = new_port_id;
+
+	p->port_id = new_port_id;
+	p->priority = newprio;
+	if (!memcmp(&p->br->bridge_id, &p->designated_bridge, 8) &&
+	    p->port_id < p->designated_port) {
+		br_become_designated_port(p);
+		br_port_state_selection(p->br);
+	}
+
+	return 0;
+}
+
+/* called under bridge lock */
+int br_stp_set_path_cost(struct net_bridge_port *p, unsigned long path_cost)
+{
+	if (path_cost < BR_MIN_PATH_COST ||
+	    path_cost > BR_MAX_PATH_COST)
+		return -ERANGE;
+
+	p->path_cost = path_cost;
+	br_configuration_update(p->br);
+	br_port_state_selection(p->br);
+	return 0;
+}
+
+ssize_t br_show_bridge_id(char *buf, const struct bridge_id *id)
+{
+	return sprintf(buf, "%.2x%.2x.%.2x%.2x%.2x%.2x%.2x%.2x\n",
+	       id->prio[0], id->prio[1],
+	       id->addr[0], id->addr[1], id->addr[2],
+	       id->addr[3], id->addr[4], id->addr[5]);
+}