/*
* Linux NET3 Bridge Support
*
* Originally by John Hayes (Network Plumbing).
* Minor hacks to get it to run with 1.3.x by Alan Cox <Alan.Cox@linux.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.
*
* Fixes:
*
* Todo:
* Don't bring up devices automatically. Start ports disabled
* and use a netlink notifier so a daemon can maintain the bridge
* port group (could we also do multiple groups ????).
* A nice /proc file interface.
* Put the path costs in the port info and devices.
* Put the bridge port number in the device structure for speed.
* Bridge SNMP stats.
*
*/
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/net.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/string.h>
#include <linux/skbuff.h>
#include <linux/if_arp.h>
#include <asm/segment.h>
#include <asm/system.h>
#include <net/br.h>
static int br_device_event(struct notifier_block *dnot, unsigned long event, void *ptr);
static void br_tick(unsigned long arg);
int br_forward(struct sk_buff *skb, int port); /* 3.7 */
int br_port_cost(struct device *dev); /* 4.10.2 */
void br_bpdu(struct sk_buff *skb); /* consumes skb */
int br_tx_frame(struct sk_buff *skb);
int br_cmp(unsigned int *a, unsigned int *b);
unsigned char bridge_ula[ETH_ALEN] = { 0x01, 0x80, 0xc2, 0x00, 0x00, 0x00 };
Bridge_data bridge_info; /* (4.5.3) */
Port_data port_info[All_ports]; /* (4.5.5) */
Config_bpdu config_bpdu[All_ports];
Tcn_bpdu tcn_bpdu[All_ports];
Timer hello_timer; /* (4.5.4.1) */
Timer tcn_timer; /* (4.5.4.2) */
Timer topology_change_timer; /* (4.5.4.3) */
Timer message_age_timer[All_ports]; /* (4.5.6.1) */
Timer forward_delay_timer[All_ports]; /* (4.5.6.2) */
Timer hold_timer[All_ports]; /* (4.5.6.3) */
/* entries timeout after this many seconds */
unsigned int fdb_aging_time = FDB_TIMEOUT;
struct br_stat br_stats;
static struct timer_list tl; /* for 1 second timer... */
/*
* the following structure is required so that we receive
* event notifications when network devices are enabled and
* disabled (ifconfig up and down).
*/
static struct notifier_block br_dev_notifier={
br_device_event,
NULL,
0
};
/** Elements of Procedure (4.6) **/
/*
* this section of code was graciously borrowed from the IEEE 802.1d
* specification section 4.9.1 starting on pg 69. It has been
* modified somewhat to fit within out framework and structure. It
* implements the spanning tree algorithm that is the heart of the
* 802.1d bridging protocol.
*/
void transmit_config(int port_no) /* (4.6.1) */
{
if (hold_timer[port_no].active) { /* (4.6.1.3.1) */
port_info[port_no].config_pending = TRUE; /* (4.6.1.3.1) */
} else { /* (4.6.1.3.2) */
config_bpdu[port_no].type = BPDU_TYPE_CONFIG;
config_bpdu[port_no].root_id = bridge_info.designated_root;
/* (4.6.1.3.2(1)) */
config_bpdu[port_no].root_path_cost = bridge_info.root_path_cost;
/* (4.6.1.3.2(2)) */
config_bpdu[port_no].bridge_id = bridge_info.bridge_id;
/* (4.6.1.3.2(3)) */
config_bpdu[port_no].port_id = port_info[port_no].port_id;
/*
* (4.6.1.3.2(4))
*/
if (root_bridge()) {
config_bpdu[port_no].message_age = Zero; /* (4.6.1.3.2(5)) */
} else {
config_bpdu[port_no].message_age
= message_age_timer[bridge_info.root_port].value
+ Message_age_increment; /* (4.6.1.3.2(6)) */
}
config_bpdu[port_no].max_age = bridge_info.max_age; /* (4.6.1.3.2(7)) */
config_bpdu[port_no].hello_time = bridge_info.hello_time;
config_bpdu[port_no].forward_delay = bridge_info.forward_delay;
config_bpdu[port_no].flags = 0;
config_bpdu[port_no].flags |=
port_info[port_no].top_change_ack ? TOPOLOGY_CHANGE_ACK : 0;
/* (4.6.1.3.2(8)) */
port_info[port_no].top_change_ack = 0;
/* (4.6.1.3.2(8)) */
config_bpdu[port_no].flags |=
bridge_info.top_change ? TOPOLOGY_CHANGE : 0;
/* (4.6.1.3.2(9)) */
send_config_bpdu(port_no, &config_bpdu[port_no]);
port_info[port_no].config_pending = FALSE; /* (4.6.1.3.2(10)) */
start_hold_timer(port_no); /* (4.6.1.3.2(11)) */
}
}
int root_bridge(void)
{
return (br_cmp(bridge_info.designated_root.BRIDGE_ID,
bridge_info.bridge_id.BRIDGE_ID)?FALSE:TRUE);
}
int supersedes_port_info(int port_no, Config_bpdu *config) /* (4.6.2.2) */
{
return (
(br_cmp(config->root_id.BRIDGE_ID,
port_info[port_no].designated_root.BRIDGE_ID) < 0) /* (4.6.2.2.1) */
||
((br_cmp(config->root_id.BRIDGE_ID,
port_info[port_no].designated_root.BRIDGE_ID) == 0
)
&&
((config->root_path_cost
< port_info[port_no].designated_cost /* (4.6.2.2.2) */
)
||
((config->root_path_cost
== port_info[port_no].designated_cost
)
&&
((br_cmp(config->bridge_id.BRIDGE_ID,
port_info[port_no].designated_bridge.BRIDGE_ID) < 0 /* (4.6.2.2.3) */
)
||
((br_cmp(config->bridge_id.BRIDGE_ID,
port_info[port_no].designated_bridge.BRIDGE_ID) == 0
) /* (4.6.2.2.4) */
&&
((br_cmp(config->bridge_id.BRIDGE_ID,
bridge_info.bridge_id.BRIDGE_ID) != 0
) /* (4.6.2.2.4(1)) */
||
(config->port_id <=
port_info[port_no].designated_port
) /* (4.6.2.2.4(2)) */
))))))
);
}
void record_config_information(int port_no, Config_bpdu *config) /* (4.6.2) */
{
port_info[port_no].designated_root = config->root_id; /* (4.6.2.3.1) */
port_info[port_no].designated_cost = config->root_path_cost;
port_info[port_no].designated_bridge = config->bridge_id;
port_info[port_no].designated_port = config->port_id;
start_message_age_timer(port_no, config->message_age); /* (4.6.2.3.2) */
}
void record_config_timeout_values(Config_bpdu *config) /* (4.6.3) */
{
bridge_info.max_age = config->max_age; /* (4.6.3.3) */
bridge_info.hello_time = config->hello_time;
bridge_info.forward_delay = config->forward_delay;
if (config->flags & TOPOLOGY_CHANGE)
bridge_info.top_change = 1;
}
void config_bpdu_generation(void)
{ /* (4.6.4) */
int port_no;
for (port_no = One; port_no <= No_of_ports; port_no++) { /* (4.6.4.3) */
if (designated_port(port_no) /* (4.6.4.3) */
&&
(port_info[port_no].state != Disabled)
) {
transmit_config(port_no); /* (4.6.4.3) */
} /* (4.6.1.2) */
}
}
int designated_port(int port_no)
{
return ((br_cmp(port_info[port_no].designated_bridge.BRIDGE_ID,
bridge_info.bridge_id.BRIDGE_ID) == 0
)
&&
(port_info[port_no].designated_port
== port_info[port_no].port_id
)
);
}
void reply(int port_no) /* (4.6.5) */
{
transmit_config(port_no); /* (4.6.5.3) */
}
void transmit_tcn(void)
{ /* (4.6.6) */
int port_no;
port_no = bridge_info.root_port;
tcn_bpdu[port_no].type = BPDU_TYPE_TOPO_CHANGE;
send_tcn_bpdu(port_no, &tcn_bpdu[bridge_info.root_port]); /* (4.6.6.3) */
}
void configuration_update(void) /* (4.6.7) */
{
root_selection(); /* (4.6.7.3.1) */
/* (4.6.8.2) */
designated_port_selection(); /* (4.6.7.3.2) */
/* (4.6.9.2) */
}
void root_selection(void)
{ /* (4.6.8) */
int root_port;
int port_no;
root_port = No_port;
for (port_no = One; port_no <= No_of_ports; port_no++) { /* (4.6.8.3.1) */
if (((!designated_port(port_no))
&&
(port_info[port_no].state != Disabled)
&&
(br_cmp(port_info[port_no].designated_root.BRIDGE_ID,
bridge_info.bridge_id.BRIDGE_ID) < 0)
)
&&
((root_port == No_port)
||
(br_cmp(port_info[port_no].designated_root.BRIDGE_ID,
port_info[root_port].designated_root.BRIDGE_ID) < 0
)
||
((br_cmp(port_info[port_no].designated_root.BRIDGE_ID,
port_info[root_port].designated_root.BRIDGE_ID) == 0
)
&&
(((port_info[port_no].designated_cost
+ port_info[port_no].path_cost
)
<
(port_info[root_port].designated_cost
+ port_info[root_port].path_cost
) /* (4.6.8.3.1(2)) */
)
||
(((port_info[port_no].designated_cost
+ port_info[port_no].path_cost
)
==
(port_info[root_port].designated_cost
+ port_info[root_port].path_cost
)
)
&&
((br_cmp(port_info[port_no].designated_bridge.BRIDGE_ID,
port_info[root_port].designated_bridge.BRIDGE_ID) < 0
) /* (4.6.8.3.1(3)) */
||
((br_cmp(port_info[port_no].designated_bridge.BRIDGE_ID,
port_info[root_port].designated_bridge.BRIDGE_ID) == 0
)
&&
((port_info[port_no].designated_port
< port_info[root_port].designated_port
) /* (4.6.8.3.1(4)) */
||
((port_info[port_no].designated_port
= port_info[root_port].designated_port
)
&&
(port_info[port_no].port_id
< port_info[root_port].port_id
) /* (4.6.8.3.1(5)) */
))))))))) {
root_port = port_no;
}
}
bridge_info.root_port = root_port; /* (4.6.8.3.1) */
if (root_port == No_port) { /* (4.6.8.3.2) */
bridge_info.designated_root = bridge_info.bridge_id;
/* (4.6.8.3.2(1)) */
bridge_info.root_path_cost = Zero;/* (4.6.8.3.2(2)) */
} else { /* (4.6.8.3.3) */
bridge_info.designated_root = port_info[root_port].designated_root;
/* (4.6.8.3.3(1)) */
bridge_info.root_path_cost = (port_info[root_port].designated_cost
+ port_info[root_port].path_cost
); /* (4.6.8.3.3(2)) */
}
}
void designated_port_selection(void)
{ /* (4.6.9) */
int port_no;
for (port_no = One; port_no <= No_of_ports; port_no++) { /* (4.6.9.3) */
if (designated_port(port_no) /* (4.6.9.3.1) */
||
(
br_cmp(port_info[port_no].designated_root.BRIDGE_ID,
bridge_info.designated_root.BRIDGE_ID) != 0
)
||
(bridge_info.root_path_cost
< port_info[port_no].designated_cost
) /* (4.6.9.3.3) */
||
((bridge_info.root_path_cost
== port_info[port_no].designated_cost
)
&&
((br_cmp(bridge_info.bridge_id.BRIDGE_ID,
port_info[port_no].designated_bridge.BRIDGE_ID) < 0
) /* (4.6.9.3.4) */
||
((br_cmp(bridge_info.bridge_id.BRIDGE_ID,
port_info[port_no].designated_bridge.BRIDGE_ID) == 0
)
&&
(port_info[port_no].port_id
<= port_info[port_no].designated_port
) /* (4.6.9.3.5) */
)))) {
become_designated_port(port_no); /* (4.6.10.3.2.2) */
}
}
}
void become_designated_port(int port_no)
{ /* (4.6.10) */
/* (4.6.10.3.1) */
port_info[port_no].designated_root = bridge_info.designated_root;
/* (4.6.10.3.2) */
port_info[port_no].designated_cost = bridge_info.root_path_cost;
/* (4.6.10.3.3) */
port_info[port_no].designated_bridge = bridge_info.bridge_id;
/* (4.6.10.3.4) */
port_info[port_no].designated_port = port_info[port_no].port_id;
}
void port_state_selection(void)
{ /* (4.6.11) */
int port_no;
for (port_no = One; port_no <= No_of_ports; port_no++) {
if (port_no == bridge_info.root_port) { /* (4.6.11.3.1) */
port_info[port_no].config_pending = FALSE; /* (4.6.11.3~1(1)) */
port_info[port_no].top_change_ack = 0;
make_forwarding(port_no); /* (4.6.11.3.1(2)) */
} else if (designated_port(port_no)) { /* (4.6.11.3.2) */
stop_message_age_timer(port_no); /* (4.6.11.3.2(1)) */
make_forwarding(port_no); /* (4.6.11.3.2(2)) */
} else { /* (4.6.11.3.3) */
port_info[port_no].config_pending = FALSE; /* (4.6.11.3.3(1)) */
port_info[port_no].top_change_ack = 0;
make_blocking(port_no); /* (4.6.11.3.3(2)) */
}
}
}
void make_forwarding(int port_no)
{ /* (4.6.12) */
if (port_info[port_no].state == Blocking) { /* (4.6.12.3) */
set_port_state(port_no, Listening); /* (4.6.12.3.1) */
start_forward_delay_timer(port_no); /* (4.6.12.3.2) */
}
}
void topology_change_detection(void)
{ /* (4.6.14) */
if (root_bridge()) { /* (4.6.14.3.1) */
bridge_info.top_change = 1;
start_topology_change_timer(); /* (4.6.14.3.1(2)) */
} else if (!(bridge_info.top_change_detected)) {
transmit_tcn(); /* (4.6.14.3.2(1)) */
start_tcn_timer(); /* (4.6.14.3.2(2)) */
}
bridge_info.top_change = 1;
}
void topology_change_acknowledged(void)
{ /* (4.6.15) */
bridge_info.top_change_detected = 0;
stop_tcn_timer(); /* (4.6.15.3.2) */
}
void acknowledge_topology_change(int port_no)
{ /* (4.6.16) */
port_info[port_no].top_change_ack = 1;
transmit_config(port_no); /* (4.6.16.3.2) */
}
void make_blocking(int port_no) /* (4.6.13) */
{
if ((port_info[port_no].state != Disabled)
&&
(port_info[port_no].state != Blocking)
/* (4.6.13.3) */
) {
if ((port_info[port_no].state == Forwarding)
||
(port_info[port_no].state == Learning)
) {
topology_change_detection(); /* (4.6.13.3.1) */
/* (4.6.14.2.3) */
}
set_port_state(port_no, Blocking);/* (4.6.13.3.2) */
stop_forward_delay_timer(port_no);/* (4.6.13.3.3) */
}
}
void set_port_state(int port_no, int state)
{
port_info[port_no].state = state;
}
void received_config_bpdu(int port_no, Config_bpdu *config) /* (4.7.1) */
{
int root;
root = root_bridge();
if (port_info[port_no].state != Disabled) {
if (supersedes_port_info(port_no, config)) { /* (4.7.1.1) *//* (4.
* 6.2.2) */
record_config_information(port_no, config); /* (4.7.1.1.1) */
/* (4.6.2.2) */
configuration_update(); /* (4.7.1.1.2) */
/* (4.6.7.2.1) */
port_state_selection(); /* (4.7.1.1.3) */
/* (4.6.11.2.1) */
if ((!root_bridge()) && root) { /* (4.7.1.1.4) */
stop_hello_timer();
if (bridge_info.top_change_detected) { /* (4.7.1.1.5~ */
stop_topology_change_timer();
transmit_tcn(); /* (4.6.6.1) */
start_tcn_timer();
}
}
if (port_no == bridge_info.root_port) {
record_config_timeout_values(config); /* (4.7.1.1.6) */
/* (4.6.3.2) */
config_bpdu_generation(); /* (4.6.4.2.1) */
if (config->flags & TOPOLOGY_CHANGE_ACK) { /* (4.7.1.1.7) */
topology_change_acknowledged(); /* (4.6.15.2) */
}
}
} else if (designated_port(port_no)) { /* (4.7.1.2) */
reply(port_no); /* (4.7.1.2.1) */
/* (4.6.5.2) */
}
}
}
void received_tcn_bpdu(int port_no, Tcn_bpdu *tcn) /* (4.7.2) */
{
if (port_info[port_no].state != Disabled) {
if (designated_port(port_no)) {
topology_change_detection(); /* (4.7.2.1) */
/* (4.6.14.2.1) */
acknowledge_topology_change(port_no); /* (4.7.2.2) */
} /* (4.6.16.2) */
}
}
void hello_timer_expiry(void)
{ /* (4.7.3) */
config_bpdu_generation(); /* (4.6.4.2.2) */
start_hello_timer();
}
void message_age_timer_expiry(int port_no) /* (4.7.4) */
{
int root;
root = root_bridge();
become_designated_port(port_no); /* (4.7.4.1) */
/* (4.6.10.2.1) */
configuration_update(); /* (4.7.4.2) */
/* (4.6.7.2.2) */
port_state_selection(); /* (4.7.4.3) */
/* (4.6.11.2.2) */
if ((root_bridge()) && (!root)) { /* (4.7.4.4) */
bridge_info.max_age = bridge_info.bridge_max_age; /* (4.7.4.4.1) */
bridge_info.hello_time = bridge_info.bridge_hello_time;
bridge_info.forward_delay = bridge_info.bridge_forward_delay;
topology_change_detection(); /* (4.7.4.4.2) */
/* (4.6.14.2.4) */
stop_tcn_timer(); /* (4.7.4.4.3) */
config_bpdu_generation(); /* (4.7.4.4.4) */
/* (4.6.4.4.3) */
start_hello_timer();
}
}
void forward_delay_timer_expiry(int port_no) /* (4.7.5) */
{
if (port_info[port_no].state == Listening) { /* (4.7.5.1) */
set_port_state(port_no, Learning); /* (4.7.5.1.1) */
start_forward_delay_timer(port_no); /* (4.7.5.1.2) */
} else if (port_info[port_no].state == Learning) { /* (4.7.5.2) */
set_port_state(port_no, Forwarding); /* (4.7.5.2.1) */
if (designated_for_some_port()) { /* (4.7.5.2.2) */
topology_change_detection(); /* (4.6.14.2.2) */
}
}
}
int designated_for_some_port(void)
{
int port_no;
for (port_no = One; port_no <= No_of_ports; port_no++) {
if ((br_cmp(port_info[port_no].designated_bridge.BRIDGE_ID,
bridge_info.bridge_id.BRIDGE_ID) == 0)
) {
return (TRUE);
}
}
return (FALSE);
}
void tcn_timer_expiry(void)
{ /* (4.7.6) */
transmit_tcn(); /* (4.7.6.1) */
start_tcn_timer(); /* (4.7.6.2) */
}
void topology_change_timer_expiry(void)
{ /* (4.7.7) */
bridge_info.top_change_detected = 0;
bridge_info.top_change = 0;
/* (4.7.7.2) */
}
void hold_timer_expiry(int port_no) /* (4.7.8) */
{
if (port_info[port_no].config_pending) {
transmit_config(port_no); /* (4.7.8.1) */
} /* (4.6.1.2.3) */
}
void br_init(void)
{ /* (4.8.1) */
int port_no;
printk(KERN_INFO "Ethernet Bridge 002 for NET3.035 (Linux 2.0)\n");
bridge_info.designated_root = bridge_info.bridge_id; /* (4.8.1.1) */
bridge_info.root_path_cost = Zero;
bridge_info.root_port = No_port;
bridge_info.bridge_max_age = BRIDGE_MAX_AGE;
bridge_info.bridge_hello_time = BRIDGE_HELLO_TIME;
bridge_info.bridge_forward_delay = BRIDGE_FORWARD_DELAY;
bridge_info.hold_time = HOLD_TIME;
bridge_info.max_age = bridge_info.bridge_max_age; /* (4.8.1.2) */
bridge_info.hello_time = bridge_info.bridge_hello_time;
bridge_info.forward_delay = bridge_info.bridge_forward_delay;
bridge_info.top_change_detected = 0;
bridge_info.top_change = 0;
stop_tcn_timer();
stop_topology_change_timer();
for (port_no = One; port_no <= No_of_ports; port_no++) { /* (4.8.1.4) */
br_init_port(port_no);
disable_port(port_no);
}
port_state_selection(); /* (4.8.1.5) */
config_bpdu_generation(); /* (4.8.1.6) */
/* initialize system timer */
tl.expires = jiffies+HZ; /* 1 second */
tl.function = br_tick;
add_timer(&tl);
register_netdevice_notifier(&br_dev_notifier);
br_stats.flags = 0; /*BR_UP | BR_DEBUG*/; /* enable bridge */
/*start_hello_timer();*/
}
void br_init_port(int port_no)
{
become_designated_port(port_no); /* (4.8.1.4.1) */
set_port_state(port_no, Blocking); /* (4.8.1.4.2) */
port_info[port_no].top_change_ack = 0;
port_info[port_no].config_pending = FALSE;/* (4.8.1.4.4) */
stop_message_age_timer(port_no); /* (4.8.1.4.5) */
stop_forward_delay_timer(port_no); /* (4.8.1.4.6) */
stop_hold_timer(port_no); /* (4.8.1.4.7) */
}
void enable_port(int port_no) /* (4.8.2) */
{
br_init_port(port_no);
port_state_selection(); /* (4.8.2.7) */
} /* */
void disable_port(int port_no) /* (4.8.3) */
{
int root;
root = root_bridge();
become_designated_port(port_no); /* (4.8.3.1) */
set_port_state(port_no, Disabled); /* (4.8.3.2) */
port_info[port_no].top_change_ack = 0;
port_info[port_no].config_pending = FALSE;/* (4.8.3.4) */
stop_message_age_timer(port_no); /* (4.8.3.5) */
stop_forward_delay_timer(port_no); /* (4.8.3.6) */
configuration_update();
port_state_selection(); /* (4.8.3.7) */
if ((root_bridge()) && (!root)) { /* (4.8.3.8) */
bridge_info.max_age = bridge_info.bridge_max_age; /* (4.8.3.8.1) */
bridge_info.hello_time = bridge_info.bridge_hello_time;
bridge_info.forward_delay = bridge_info.bridge_forward_delay;
topology_change_detection(); /* (4.8.3.8.2) */
stop_tcn_timer(); /* (4.8.3.8.3) */
config_bpdu_generation(); /* (4.8.3.8.4) */
start_hello_timer();
}
}
void set_bridge_priority(bridge_id_t *new_bridge_id) /* (4.8.4) */
{
int root;
int port_no;
root = root_bridge();
for (port_no = One; port_no <= No_of_ports; port_no++) { /* (4.8.4.2) */
if (designated_port(port_no)) {
port_info[port_no].designated_bridge = *new_bridge_id;
}
}
bridge_info.bridge_id = *new_bridge_id; /* (4.8.4.3) */
configuration_update(); /* (4.8.4.4) */
port_state_selection(); /* (4.8.4.5) */
if ((root_bridge()) && (!root)) { /* (4.8.4.6) */
bridge_info.max_age = bridge_info.bridge_max_age; /* (4.8.4.6.1) */
bridge_info.hello_time = bridge_info.bridge_hello_time;
bridge_info.forward_delay = bridge_info.bridge_forward_delay;
topology_change_detection(); /* (4.8.4.6.2) */
stop_tcn_timer(); /* (4.8.4.6.3) */
config_bpdu_generation(), /* (4.8.4.6.4) */
start_hello_timer();
}
}
void set_port_priority(int port_no, unsigned short new_port_id) /* (4.8.5) */
{
if (designated_port(port_no)) { /* (4.8.5.2) */
port_info[port_no].designated_port = new_port_id;
}
port_info[port_no].port_id = new_port_id; /* (4.8.5.3) */
if ((br_cmp(bridge_info.bridge_id.BRIDGE_ID,
port_info[port_no].designated_bridge.BRIDGE_ID) == 0
)
&&
(port_info[port_no].port_id
< port_info[port_no].designated_port
)
) {
become_designated_port(port_no); /* (4.8.5.4.1) */
port_state_selection(); /* (4.8.5.4.2) */
}
}
void set_path_cost(int port_no, unsigned short path_cost) /* (4.8.6) */
{
port_info[port_no].path_cost = path_cost; /* (4.8.6.1) */
configuration_update(); /* (4.8.6.2) */
port_state_selection(); /* (4.8.6.3) */
}
static void br_tick(unsigned long arg)
{
int port_no;
if (hello_timer_expired()) {
hello_timer_expiry();
}
if (tcn_timer_expired()) {
tcn_timer_expiry();
}
if (topology_change_timer_expired()) {
topology_change_timer_expiry();
}
for (port_no = One; port_no <= No_of_ports; port_no++) {
if (forward_delay_timer_expired(port_no)) {
forward_delay_timer_expiry(port_no);
}
if (message_age_timer_expired(port_no)) {
message_age_timer_expiry(port_no);
}
if (hold_timer_expired(port_no)) {
hold_timer_expiry(port_no);
}
}
/* call me again sometime... */
tl.expires = jiffies+HZ; /* 1 second */
tl.function = br_tick;
add_timer(&tl);
}
void start_hello_timer(void)
{
hello_timer.value = 0;
hello_timer.active = TRUE;
}
void stop_hello_timer(void)
{
hello_timer.active = FALSE;
}
int hello_timer_expired(void)
{
if (hello_timer.active && (++hello_timer.value >= bridge_info.hello_time)) {
hello_timer.active = FALSE;
return (TRUE);
}
return (FALSE);
}
void start_tcn_timer(void)
{
tcn_timer.value = 0;
tcn_timer.active = TRUE;
}
void stop_tcn_timer(void)
{
tcn_timer.active = FALSE;
}
int tcn_timer_expired(void)
{
if (tcn_timer.active && (++tcn_timer.value >=
bridge_info.bridge_hello_time)) {
tcn_timer.active = FALSE;
return (TRUE);
}
return (FALSE);
}
void start_topology_change_timer(void)
{
topology_change_timer.value = 0;
topology_change_timer.active = TRUE;
}
void stop_topology_change_timer(void)
{
topology_change_timer.active = FALSE;
}
int topology_change_timer_expired(void)
{
if (topology_change_timer.active
&& (++topology_change_timer.value
>= bridge_info.topology_change_time
)) {
topology_change_timer.active = FALSE;
return (TRUE);
}
return (FALSE);
}
void start_message_age_timer(int port_no, unsigned short message_age)
{
message_age_timer[port_no].value = message_age;
message_age_timer[port_no].active = TRUE;
}
void stop_message_age_timer(int port_no)
{
message_age_timer[port_no].active = FALSE;
}
int message_age_timer_expired(int port_no)
{
if (message_age_timer[port_no].active &&
(++message_age_timer[port_no].value >= bridge_info.max_age)) {
message_age_timer[port_no].active = FALSE;
return (TRUE);
}
return (FALSE);
}
void start_forward_delay_timer(int port_no)
{
forward_delay_timer[port_no].value = 0;
forward_delay_timer[port_no].active = TRUE;
}
void stop_forward_delay_timer(int port_no)
{
forward_delay_timer[port_no].active = FALSE;
}
int forward_delay_timer_expired(int port_no)
{
if (forward_delay_timer[port_no].active &&
(++forward_delay_timer[port_no].value >= bridge_info.forward_delay)) {
forward_delay_timer[port_no].active = FALSE;
return (TRUE);
}
return (FALSE);
}
void start_hold_timer(int port_no)
{
hold_timer[port_no].value = 0;
hold_timer[port_no].active = TRUE;
}
void stop_hold_timer(int port_no)
{
hold_timer[port_no].active = FALSE;
}
int hold_timer_expired(int port_no)
{
if (hold_timer[port_no].active &&
(++hold_timer[port_no].value >= bridge_info.hold_time)) {
hold_timer[port_no].active = FALSE;
return (TRUE);
}
return (FALSE);
}
int send_config_bpdu(int port_no, Config_bpdu *config_bpdu)
{
struct sk_buff *skb;
struct device *dev = port_info[port_no].dev;
int size;
unsigned long flags;
if (port_info[port_no].state == Disabled) {
printk(KERN_DEBUG "send_config_bpdu: port %i not valid\n",port_no);
return(-1);
}
if (br_stats.flags & BR_DEBUG)
printk("send_config_bpdu: ");
/*
* create and send the message
*/
size = sizeof(Config_bpdu) + dev->hard_header_len;
skb = alloc_skb(size, GFP_ATOMIC);
if (skb == NULL) {
printk(KERN_DEBUG "send_config_bpdu: no skb available\n");
return(-1);
}
skb->dev = dev;
skb->free = 1;
skb->h.eth = (struct ethhdr *)skb_put(skb, size);
memcpy(skb->h.eth->h_dest, bridge_ula, ETH_ALEN);
memcpy(skb->h.eth->h_source, dev->dev_addr, ETH_ALEN);
if (br_stats.flags & BR_DEBUG)
printk("port %i src %02x:%02x:%02x:%02x:%02x:%02x\
dest %02x:%02x:%02x:%02x:%02x:%02x\n",
port_no,
skb->h.eth->h_source[0],
skb->h.eth->h_source[1],
skb->h.eth->h_source[2],
skb->h.eth->h_source[3],
skb->h.eth->h_source[4],
skb->h.eth->h_source[5],
skb->h.eth->h_dest[0],
skb->h.eth->h_dest[1],
skb->h.eth->h_dest[2],
skb->h.eth->h_dest[3],
skb->h.eth->h_dest[4],
skb->h.eth->h_dest[5]);
skb->h.eth->h_proto = htonl(0x8038); /* XXX verify */
skb->h.raw += skb->dev->hard_header_len;
memcpy(skb->h.raw, config_bpdu, sizeof(Config_bpdu));
/* won't get bridged again... */
skb->pkt_bridged = IS_BRIDGED;
skb->arp = 1; /* do not resolve... */
skb->h.raw = skb->data + ETH_HLEN;
save_flags(flags);
cli();
skb_queue_tail(dev->buffs, skb);
restore_flags(flags);
return(0);
}
int send_tcn_bpdu(int port_no, Tcn_bpdu *bpdu)
{
struct sk_buff *skb;
struct device *dev = port_info[port_no].dev;
int size;
unsigned long flags;
if (port_info[port_no].state == Disabled) {
printk(KERN_DEBUG "send_tcn_bpdu: port %i not valid\n",port_no);
return(-1);
}
if (br_stats.flags & BR_DEBUG)
printk("send_tcn_bpdu: ");
size = sizeof(Tcn_bpdu) + dev->hard_header_len;
skb = alloc_skb(size, GFP_ATOMIC);
if (skb == NULL) {
printk(KERN_DEBUG "send_tcn_bpdu: no skb available\n");
return(-1);
}
skb->dev = dev;
skb->free = 1;
skb->h.eth = (struct ethhdr *)skb_put(skb,size);
memcpy(skb->h.eth->h_dest, bridge_ula, ETH_ALEN);
memcpy(skb->h.eth->h_source, dev->dev_addr, ETH_ALEN);
if (br_stats.flags & BR_DEBUG)
printk("port %i src %02x:%02x:%02x:%02x:%02x:%02x\
dest %02x:%02x:%02x:%02x:%02x:%02x\n",
port_no,
skb->h.eth->h_source[0],
skb->h.eth->h_source[1],
skb->h.eth->h_source[2],
skb->h.eth->h_source[3],
skb->h.eth->h_source[4],
skb->h.eth->h_source[5],
skb->h.eth->h_dest[0],
skb->h.eth->h_dest[1],
skb->h.eth->h_dest[2],
skb->h.eth->h_dest[3],
skb->h.eth->h_dest[4],
skb->h.eth->h_dest[5]);
skb->h.eth->h_proto = 0x8038; /* XXX verify */
skb->h.raw += skb->dev->hard_header_len;
memcpy(skb->h.raw, bpdu, sizeof(Tcn_bpdu));
/* mark that's we've been here... */
skb->pkt_bridged = IS_BRIDGED;
skb->arp = 1; /* do not resolve... */
skb->h.raw = skb->data + ETH_HLEN;
save_flags(flags);
cli();
skb_queue_tail(dev->buffs, skb);
restore_flags(flags);
return(0);
}
static int br_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
{
struct device *dev = ptr;
int i;
/* check for loopback devices */
if (dev->flags & IFF_LOOPBACK)
return(NOTIFY_DONE);
switch (event) {
case NETDEV_DOWN:
if (br_stats.flags & BR_DEBUG)
printk("br_device_event: NETDEV_DOWN...\n");
/* find our device and mark it down */
for (i = One; i <= No_of_ports; i++) {
if (port_info[i].dev == dev) {
disable_port(i);
return NOTIFY_DONE;
break;
}
}
break;
case NETDEV_UP:
if (br_stats.flags & BR_DEBUG)
printk("br_device_event: NETDEV_UP...\n");
/* Only handle ethernet ports */
if(dev->type!=ARPHRD_ETHER && dev->type!=ARPHRD_LOOPBACK)
return NOTIFY_DONE;
/* look up an unused device and enable it */
for (i = One; i <= No_of_ports; i++) {
if ((port_info[i].dev == (struct device *)0) ||
(port_info[i].dev == dev)) {
port_info[i].dev = dev;
enable_port(i);
set_path_cost(i, br_port_cost(dev));
set_port_priority(i, 128);
port_info[i].port_id = i;
/* set bridge addr from 1st device addr */
if ((bridge_info.bridge_id.BRIDGE_ID[0] == 0) &&
(bridge_info.bridge_id.BRIDGE_ID[1] == 0)) {
memcpy(bridge_info.bridge_id.BRIDGE_ID_ULA, dev->dev_addr, 6);
bridge_info.bridge_id.BRIDGE_PRIORITY = port_info[i].port_id;
set_bridge_priority(&bridge_info.bridge_id);
}
make_forwarding(i);
return NOTIFY_DONE;
break;
}
}
break;
#if 0
default:
printk("br_device_event: unknown event [%x]\n",
(unsigned int)event);
#endif
}
return NOTIFY_DONE;
}
/*
* following routine is called when a frame is received
* from an interface, it returns 1 when it consumes the
* frame, 0 when it does not
*/
int br_receive_frame(struct sk_buff *skb) /* 3.5 */
{
int port;
int i;
if (br_stats.flags & BR_DEBUG)
printk("br_receive_frame: ");
/* sanity */
if (!skb) {
printk(KERN_CRIT "br_receive_frame: no skb!\n");
return(1);
}
skb->pkt_bridged = IS_BRIDGED;
/* check for loopback */
if (skb->dev->flags & IFF_LOOPBACK)
return(0);
port = find_port(skb->dev);
skb->arp = 1; /* Received frame so it is resolved */
skb->h.raw = skb->mac.raw;
if (br_stats.flags & BR_DEBUG)
printk("port %i src %02x:%02x:%02x:%02x:%02x:%02x\
dest %02x:%02x:%02x:%02x:%02x:%02x\n",
port,
skb->h.eth->h_source[0],
skb->h.eth->h_source[1],
skb->h.eth->h_source[2],
skb->h.eth->h_source[3],
skb->h.eth->h_source[4],
skb->h.eth->h_source[5],
skb->h.eth->h_dest[0],
skb->h.eth->h_dest[1],
skb->h.eth->h_dest[2],
skb->h.eth->h_dest[3],
skb->h.eth->h_dest[4],
skb->h.eth->h_dest[5]);
if (!port) {
if(br_stats.flags&BR_DEBUG)
printk("\nbr_receive_frame: no port!\n");
return(0);
}
switch (port_info[port].state)
{
case Learning:
(void) br_learn(skb, port); /* 3.8 */
/* fall through */
case Listening:
/* process BPDUs */
if (memcmp(skb->h.eth->h_dest, bridge_ula, 6) == 0) {
br_bpdu(skb);
return(1); /* br_bpdu consumes skb */
}
/* fall through */
case Blocking:
/* fall through */
case Disabled:
/* should drop frames, but for now, we let
* them get passed up to the next higher layer
return(br_drop(skb));
*/
return(0); /* pass frame up stack */
break;
case Forwarding:
(void) br_learn(skb, port); /* 3.8 */
/* process BPDUs */
if (memcmp(skb->h.eth->h_dest, bridge_ula,
ETH_ALEN) == 0)
{
/*printk("frame bpdu processor for me!!!\n");*/
br_bpdu(skb);
return(1); /* br_bpdu consumes skb */
}
/* is frame for me? */
if (memcmp(skb->h.eth->h_dest,
port_info[port].dev->dev_addr,
ETH_ALEN) == 0)
{
/* Packet is for us */
skb->pkt_type = PACKET_HOST;
return(0); /* pass frame up our stack (this will */
/* happen in net_bh() in dev.c) */
}
/* ok, forward this frame... */
return(br_forward(skb, port));
default:
printk(KERN_DEBUG "br_receive_frame: port [%i] unknown state [%i]\n",
port, port_info[port].state);
return(0); /* pass frame up stack? */
}
}
/*
* the following routine is called to transmit frames from the host
* stack. it returns 1 when it consumes the frame and
* 0 when it does not.
*/
int br_tx_frame(struct sk_buff *skb) /* 3.5 */
{
int port;
/* sanity */
if (!skb)
{
printk(KERN_CRIT "br_tx_frame: no skb!\n");
return(0);
}
if (!skb->dev)
{
printk(KERN_CRIT "br_tx_frame: no dev!\n");
return(0);
}
/* check for loopback */
if (skb->dev->flags & IFF_LOOPBACK)
return(0);
skb->h.raw = skb->data;
port = 0; /* an impossible port */
if (br_stats.flags & BR_DEBUG)
printk("br_tx_fr : port %i src %02x:%02x:%02x:%02x:%02x:%02x\
dest %02x:%02x:%02x:%02x:%02x:%02x\n",
port,
skb->h.eth->h_source[0],
skb->h.eth->h_source[1],
skb->h.eth->h_source[2],
skb->h.eth->h_source[3],
skb->h.eth->h_source[4],
skb->h.eth->h_source[5],
skb->h.eth->h_dest[0],
skb->h.eth->h_dest[1],
skb->h.eth->h_dest[2],
skb->h.eth->h_dest[3],
skb->h.eth->h_dest[4],
skb->h.eth->h_dest[5]);
return(br_forward(skb, port));
}
/*
* this routine returns 0 when it learns (or updates) from the
* frame, and -1 if the frame is simply discarded due to port
* state or lack of resources...
*/
int br_learn(struct sk_buff *skb, int port) /* 3.8 */
{
struct fdb *f;
switch (port_info[port].state) {
case Listening:
case Blocking:
case Disabled:
default:
return(-1);
/* break; */
case Learning:
case Forwarding:
/* don't keep group addresses in the tree */
if (skb->h.eth->h_source[0] & 0x01)
return(-1);
f = (struct fdb *)kmalloc(sizeof(struct fdb),
GFP_ATOMIC);
if (!f) {
printk(KERN_DEBUG "br_learn: unable to malloc fdb\n");
return(-1);
}
f->port = port; /* source port */
memcpy(f->ula, skb->h.eth->h_source, 6);
f->timer = CURRENT_TIME;
f->flags = FDB_ENT_VALID;
/*
* add entity to AVL tree. If entity already
* exists in the tree, update the fields with
* what we have here.
*/
if (br_avl_insert(f) == 0) { /* update */
kfree(f);
return(0);
}
/* add to head of port chain */
f->fdb_next = port_info[port].fdb;
port_info[port].fdb = f;
return(0);
/* break */
}
}
/*
* this routine always consumes the frame
*/
int br_drop(struct sk_buff *skb)
{
kfree_skb(skb, 0);
return(1);
}
/*
* this routine always consumes the frame
*/
int br_dev_drop(struct sk_buff *skb)
{
dev_kfree_skb(skb, 0);
return(1);
}
/*
* this routine returns 1 if it consumes the frame, 0
* if not...
*/
int br_forward(struct sk_buff *skb, int port) /* 3.7 */
{
struct fdb *f;
/*
* flood all ports with frames destined for a group
* address. If frame came from above, drop it,
* otherwise it will be handled in br_receive_frame()
* Multicast frames will also need to be seen
* by our upper layers.
*/
if (skb->h.eth->h_dest[0] & 0x01)
{
/* group address */
br_flood(skb, port);
/*
* External groups are fed out via the normal source
* This probably should be dropped since the flood will
* have sent it anyway.
*/
if (port == 0) /* locally generated */
return(br_dev_drop(skb));
return(0);
} else {
/* locate port to forward to */
f = br_avl_find_addr(skb->h.eth->h_dest);
/*
* Send flood and drop.
*/
if (!f || !(f->flags & FDB_ENT_VALID)) {
/* not found; flood all ports */
br_flood(skb, port);
return(br_dev_drop(skb));
}
/*
* Sending
*/
if (f->port!=port && port_info[f->port].state == Forwarding) {
/* has entry expired? */
if (f->timer + fdb_aging_time < CURRENT_TIME) {
/* timer expired, invalidate entry */
f->flags &= ~FDB_ENT_VALID;
if (br_stats.flags & BR_DEBUG)
printk("fdb entry expired...\n");
/*
* Send flood and drop original
*/
br_flood(skb, port);
return(br_dev_drop(skb));
}
/* mark that's we've been here... */
skb->pkt_bridged = IS_BRIDGED;
/* reset the skb->ip pointer */
skb->h.raw = skb->data + ETH_HLEN;
/*
* Send the buffer out.
*/
skb->dev=port_info[f->port].dev;
/*
* We send this still locked
*/
dev_queue_xmit(skb, skb->dev,1);
return(1); /* skb has been consumed */
} else {
/*
* Arrived on the right port, we discard
*/
return(br_dev_drop(skb));
}
}
}
/*
* this routine sends a copy of the frame to all forwarding ports
* with the exception of the port given. This routine never
* consumes the original frame.
*/
int br_flood(struct sk_buff *skb, int port)
{
int i;
struct sk_buff *nskb;
for (i = One; i <= No_of_ports; i++)
{
if (i == port)
continue;
if (port_info[i].state == Forwarding)
{
nskb = skb_clone(skb, GFP_ATOMIC);
if(nskb==NULL)
continue;
/* mark that's we've been here... */
nskb->pkt_bridged = IS_BRIDGED;
/* Send to each port in turn */
nskb->dev= port_info[i].dev;
/* To get here we must have done ARP already,
or have a received valid MAC header */
nskb->arp = 1;
/* printk("Flood to port %d\n",i);*/
nskb->h.raw = nskb->data + ETH_HLEN;
dev_queue_xmit(nskb,nskb->dev,1);
}
}
return(0);
}
int find_port(struct device *dev)
{
int i;
for (i = One; i <= No_of_ports; i++)
if ((port_info[i].dev == dev) &&
(port_info[i].state != Disabled))
return(i);
return(0);
}
int br_port_cost(struct device *dev) /* 4.10.2 */
{
if (strncmp(dev->name, "eth", 3) == 0) /* ethernet */
return(100);
if (strncmp(dev->name, "wic", 3) == 0) /* wic */
return(1600);
if (strncmp(dev->name, "plip",4) == 0) /* plip */
return (1600);
return(100); /* default */
}
/*
* this routine always consumes the skb
*/
void br_bpdu(struct sk_buff *skb) /* consumes skb */
{
Tcn_bpdu *bpdu;
int port;
port = find_port(skb->dev);
if (port == 0) { /* unknown port */
br_drop(skb);
return;
}
bpdu = (Tcn_bpdu *) (skb->data + ETH_HLEN);
switch (bpdu->type) {
case BPDU_TYPE_CONFIG:
received_config_bpdu(port, (Config_bpdu *)bpdu);
break;
case BPDU_TYPE_TOPO_CHANGE:
received_tcn_bpdu(port, bpdu);
break;
default:
printk(KERN_DEBUG "br_bpdu: received unknown bpdu, type = %i\n",
bpdu->type);
/* break; */
}
br_drop(skb);
}
int br_ioctl(unsigned int cmd, void *arg)
{
int err;
struct br_cf bcf;
switch(cmd)
{
case SIOCGIFBR: /* get bridging control blocks */
err = verify_area(VERIFY_WRITE, arg,
sizeof(struct br_stat));
if(err)
return err;
memcpy(&br_stats.bridge_data, &bridge_info, sizeof(Bridge_data));
memcpy(&br_stats.port_data, &port_info, sizeof(Port_data)*No_of_ports);
memcpy_tofs(arg, &br_stats, sizeof(struct br_stat));
return(0);
case SIOCSIFBR:
if (!suser())
return -EPERM;
err = verify_area(VERIFY_READ, arg,
sizeof(struct br_cf));
if(err)
return err;
memcpy_fromfs(&bcf, arg, sizeof(struct br_cf));
switch (bcf.cmd) {
case BRCMD_BRIDGE_ENABLE:
if (br_stats.flags & BR_UP)
return(-EALREADY);
printk(KERN_DEBUG "br: enabling bridging function\n");
br_stats.flags |= BR_UP; /* enable bridge */
start_hello_timer();
break;
case BRCMD_BRIDGE_DISABLE:
if (!(br_stats.flags & BR_UP))
return(-EALREADY);
printk(KERN_DEBUG "br: disabling bridging function\n");
br_stats.flags &= ~BR_UP; /* disable bridge */
stop_hello_timer();
#if 0
for (i = One; i <= No_of_ports; i++)
if (port_info[i].state != Disabled)
disable_port(i);
#endif
break;
case BRCMD_PORT_ENABLE:
if (port_info[bcf.arg1].dev == 0)
return(-EINVAL);
if (port_info[bcf.arg1].state != Disabled)
return(-EALREADY);
printk(KERN_DEBUG "br: enabling port %i\n",bcf.arg1);
enable_port(bcf.arg1);
break;
case BRCMD_PORT_DISABLE:
if (port_info[bcf.arg1].dev == 0)
return(-EINVAL);
if (port_info[bcf.arg1].state == Disabled)
return(-EALREADY);
printk(KERN_DEBUG "br: disabling port %i\n",bcf.arg1);
disable_port(bcf.arg1);
break;
case BRCMD_SET_BRIDGE_PRIORITY:
set_bridge_priority((bridge_id_t *)&bcf.arg1);
break;
case BRCMD_SET_PORT_PRIORITY:
if (port_info[bcf.arg1].dev == 0)
return(-EINVAL);
set_port_priority(bcf.arg1, bcf.arg2);
break;
case BRCMD_SET_PATH_COST:
if (port_info[bcf.arg1].dev == 0)
return(-EINVAL);
set_path_cost(bcf.arg1, bcf.arg2);
break;
case BRCMD_ENABLE_DEBUG:
br_stats.flags |= BR_DEBUG;
break;
case BRCMD_DISABLE_DEBUG:
br_stats.flags &= ~BR_DEBUG;
break;
default:
return -EINVAL;
}
return(0);
default:
return -EINVAL;
}
/*NOTREACHED*/
return 0;
}
int br_cmp(unsigned int *a, unsigned int *b)
{
int i;
for (i=0; i<2; i++)
{
if (a[i] == b[i])
continue;
if (a[i] < b[i])
return(1);
if (a[i] > b[i])
return(-1);
}
return(0);
}
