Support >256 ports on a bridge. Use the suggestion of reducing
the number of bits of priority and increasing the number of bits
for port number.
Easy to increase to even larger if necessary.
diff -Nru a/net/bridge/br_if.c b/net/bridge/br_if.c
--- a/net/bridge/br_if.c Tue Apr 13 13:16:56 2004
+++ b/net/bridge/br_if.c Tue Apr 13 13:16:56 2004
@@ -24,9 +24,6 @@
#include "br_private.h"
-/* Limited to 256 ports because of STP protocol pdu */
-#define BR_MAX_PORTS 256
-
/*
* Determine initial path cost based on speed.
* using recommendations from 802.1d standard
@@ -166,23 +163,27 @@
return br;
}
-static int free_port(struct net_bridge *br)
+/* find an available port number */
+static int find_portno(struct net_bridge *br)
{
int index;
struct net_bridge_port *p;
- long inuse[BR_MAX_PORTS/(sizeof(long)*8)];
+ unsigned long *inuse;
+
+ inuse = kmalloc(BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long),
+ GFP_ATOMIC);
+ if (!inuse)
+ return -ENOMEM;
- /* find free port number */
- memset(inuse, 0, sizeof(inuse));
+ CLEAR_BITMAP(inuse, BR_MAX_PORTS);
+ set_bit(0, inuse); /* zero is reserved */
list_for_each_entry(p, &br->port_list, list) {
set_bit(p->port_no, inuse);
}
-
index = find_first_zero_bit(inuse, BR_MAX_PORTS);
- if (index >= BR_MAX_PORTS)
- return -EXFULL;
+ kfree(inuse);
- return index;
+ return (index >= BR_MAX_PORTS) ? -EXFULL : index;
}
/* called under bridge lock */
@@ -193,7 +194,7 @@
int index;
struct net_bridge_port *p;
- index = free_port(br);
+ index = find_portno(br);
if (index < 0)
return ERR_PTR(index);
@@ -206,7 +207,7 @@
dev_hold(dev);
p->dev = dev;
p->path_cost = cost;
- p->priority = 0x80;
+ p->priority = 0x8000 >> BR_PORT_BITS;
dev->br_port = p;
p->port_no = index;
br_init_port(p);
diff -Nru a/net/bridge/br_ioctl.c b/net/bridge/br_ioctl.c
--- a/net/bridge/br_ioctl.c Tue Apr 13 13:16:56 2004
+++ b/net/bridge/br_ioctl.c Tue Apr 13 13:16:56 2004
@@ -91,9 +91,15 @@
case BRCTL_GET_PORT_LIST:
{
- int num = arg1 ? arg1 : 256; /* compatiablity */
- int ret = 0;
- int *indices;
+ int num, *indices;
+
+ num = arg1;
+ if (num < 0)
+ return -EINVAL;
+ if (num == 0)
+ num = 256;
+ if (num > BR_MAX_PORTS)
+ num = BR_MAX_PORTS;
indices = kmalloc(num*sizeof(int), GFP_KERNEL);
if (indices == NULL)
@@ -103,9 +109,9 @@
br_get_port_ifindices(br, indices, num);
if (copy_to_user((void *)arg0, indices, num*sizeof(int)))
- ret = -EFAULT;
+ num = -EFAULT;
kfree(indices);
- return ret;
+ return num;
}
case BRCTL_SET_BRIDGE_FORWARD_DELAY:
@@ -204,6 +210,9 @@
if (!capable(CAP_NET_ADMIN))
return -EPERM;
+
+ if (arg1 >= (1<<(16-BR_PORT_BITS)))
+ return -ERANGE;
spin_lock_bh(&br->lock);
if ((p = br_get_port(br, arg0)) == NULL)
diff -Nru a/net/bridge/br_private.h b/net/bridge/br_private.h
--- a/net/bridge/br_private.h Tue Apr 13 13:16:56 2004
+++ b/net/bridge/br_private.h Tue Apr 13 13:16:56 2004
@@ -24,6 +24,9 @@
#define BR_HOLD_TIME (1*HZ)
+#define BR_PORT_BITS 10
+#define BR_MAX_PORTS (1<<BR_PORT_BITS)
+
typedef struct bridge_id bridge_id;
typedef struct mac_addr mac_addr;
typedef __u16 port_id;
diff -Nru a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
--- a/net/bridge/br_stp_if.c Tue Apr 13 13:16:56 2004
+++ b/net/bridge/br_stp_if.c Tue Apr 13 13:16:56 2004
@@ -19,15 +19,21 @@
#include "br_private.h"
#include "br_private_stp.h"
-static inline __u16 br_make_port_id(const struct net_bridge_port *p)
+
+/* Port id is composed of priority and port number.
+ * NB: least significant 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 (p->priority << 8) | p->port_no;
+ return ((u16)priority << BR_PORT_BITS)
+ | (port_no & ((1<<BR_PORT_BITS)-1));
}
/* called under bridge lock */
void br_init_port(struct net_bridge_port *p)
{
- p->port_id = br_make_port_id(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;
@@ -185,15 +191,13 @@
/* called under bridge lock */
void br_stp_set_port_priority(struct net_bridge_port *p, u8 newprio)
{
- __u16 new_port_id;
-
- p->priority = newprio & 0xFF;
- new_port_id = br_make_port_id(p);
+ port_id 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);
