Commit 7e40dbf8 authored by Stephen Hemminger's avatar Stephen Hemminger

[BRIDGE]: Read forwarding table chunk at a time.

Change how the read of forwarding table works.  Instead of copying
entries to user one at a time, use an intermediate kernel buffer and
do up to a page at a chunk.

This gets rid of some awkward code dealing with entries getting deleted
during the copy.  And allows same function to be used by later sysfs
hook.
parent 367c89b5
...@@ -16,11 +16,10 @@ ...@@ -16,11 +16,10 @@
#include <linux/kernel.h> #include <linux/kernel.h>
#include <linux/init.h> #include <linux/init.h>
#include <linux/spinlock.h> #include <linux/spinlock.h>
#include <linux/if_bridge.h>
#include <linux/times.h> #include <linux/times.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h> #include <linux/etherdevice.h>
#include <asm/atomic.h> #include <asm/atomic.h>
#include <asm/uaccess.h>
#include "br_private.h" #include "br_private.h"
static kmem_cache_t *br_fdb_cache; static kmem_cache_t *br_fdb_cache;
...@@ -54,17 +53,6 @@ static __inline__ int has_expired(const struct net_bridge *br, ...@@ -54,17 +53,6 @@ static __inline__ int has_expired(const struct net_bridge *br,
&& time_before_eq(fdb->ageing_timer + hold_time(br), jiffies); && time_before_eq(fdb->ageing_timer + hold_time(br), jiffies);
} }
static inline void copy_fdb(struct __fdb_entry *ent,
const struct net_bridge_fdb_entry *f)
{
memset(ent, 0, sizeof(struct __fdb_entry));
memcpy(ent->mac_addr, f->addr.addr, ETH_ALEN);
ent->port_no = f->dst?f->dst->port_no:0;
ent->is_local = f->is_local;
ent->ageing_timer_value = f->is_static ? 0
: jiffies_to_clock_t(jiffies - f->ageing_timer);
}
static __inline__ int br_mac_hash(const unsigned char *mac) static __inline__ int br_mac_hash(const unsigned char *mac)
{ {
unsigned long x; unsigned long x;
...@@ -214,68 +202,48 @@ void br_fdb_put(struct net_bridge_fdb_entry *ent) ...@@ -214,68 +202,48 @@ void br_fdb_put(struct net_bridge_fdb_entry *ent)
kmem_cache_free(br_fdb_cache, ent); kmem_cache_free(br_fdb_cache, ent);
} }
int br_fdb_get_entries(struct net_bridge *br, /*
unsigned char *_buf, * Fill buffer with forwarding table records in
int maxnum, * the API format.
int offset) */
int br_fdb_fillbuf(struct net_bridge *br, void *buf,
unsigned long maxnum, unsigned long skip)
{ {
int i; struct __fdb_entry *fe = buf;
int num; int i, num = 0;
struct __fdb_entry *walk; struct hlist_node *h;
struct net_bridge_fdb_entry *f;
num = 0; memset(buf, 0, maxnum*sizeof(struct __fdb_entry));
walk = (struct __fdb_entry *)_buf;
read_lock_bh(&br->hash_lock); read_lock_bh(&br->hash_lock);
for (i=0;i<BR_HASH_SIZE;i++) { for (i = 0; i < BR_HASH_SIZE; i++) {
struct hlist_node *h; hlist_for_each_entry(f, h, &br->hash[i], hlist) {
hlist_for_each(h, &br->hash[i]) {
struct net_bridge_fdb_entry *f
= hlist_entry(h, struct net_bridge_fdb_entry, hlist);
struct __fdb_entry ent;
if (num >= maxnum) if (num >= maxnum)
goto out; goto out;
if (has_expired(br, f)) if (has_expired(br, f))
continue; continue;
if (offset) { if (skip) {
offset--; --skip;
continue; continue;
} }
copy_fdb(&ent, f); /* convert from internal format to API */
memcpy(fe->mac_addr, f->addr.addr, ETH_ALEN);
atomic_inc(&f->use_count); fe->port_no = f->dst->port_no;
read_unlock_bh(&br->hash_lock); fe->is_local = f->is_local;
if (!f->is_static)
if (copy_to_user(walk, &ent, sizeof(struct __fdb_entry))) fe->ageing_timer_value = jiffies_to_clock_t(jiffies - f->ageing_timer);
return -EFAULT; ++fe;
++num;
read_lock_bh(&br->hash_lock);
/* entry was deleted during copy_to_user */
if (atomic_dec_and_test(&f->use_count)) {
kmem_cache_free(br_fdb_cache, f);
num = -EAGAIN;
goto out;
}
/* entry changed address hash while copying */
if (br_mac_hash(f->addr.addr) != i) {
num = -EAGAIN;
goto out;
}
num++;
walk++;
} }
} }
out: out:
read_unlock_bh(&br->hash_lock); read_unlock_bh(&br->hash_lock);
return num; return num;
} }
......
...@@ -52,6 +52,39 @@ static void get_port_ifindices(struct net_bridge *br, int *ifindices, int num) ...@@ -52,6 +52,39 @@ static void get_port_ifindices(struct net_bridge *br, int *ifindices, int num)
} }
} }
/*
* Format up to a page worth of forwarding table entries
* userbuf -- where to copy result
* maxnum -- maximum number of entries desired
* (limited to a page for sanity)
* offset -- number of records to skip
*/
static int get_fdb_entries(struct net_bridge *br, void __user *userbuf,
unsigned long maxnum, unsigned long offset)
{
int num;
void *buf;
size_t size = maxnum * sizeof(struct __fdb_entry);
if (size > PAGE_SIZE) {
size = PAGE_SIZE;
maxnum = PAGE_SIZE/sizeof(struct __fdb_entry);
}
buf = kmalloc(size, GFP_USER);
if (!buf)
return -ENOMEM;
num = br_fdb_fillbuf(br, buf, maxnum, offset);
if (num > 0) {
if (copy_to_user(userbuf, buf, num*sizeof(struct __fdb_entry)))
num = -EFAULT;
}
kfree(buf);
return num;
}
int br_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd) int br_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
{ {
struct net_bridge *br = netdev_priv(dev); struct net_bridge *br = netdev_priv(dev);
...@@ -270,7 +303,8 @@ int br_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd) ...@@ -270,7 +303,8 @@ int br_dev_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
} }
case BRCTL_GET_FDB_ENTRIES: case BRCTL_GET_FDB_ENTRIES:
return br_fdb_get_entries(br, (void *)args[1], args[2], args[3]); return get_fdb_entries(br, (void __user *)args[1],
args[2], args[3]);
} }
return -EOPNOTSUPP; return -EOPNOTSUPP;
......
...@@ -137,10 +137,8 @@ extern void br_fdb_delete_by_port(struct net_bridge *br, ...@@ -137,10 +137,8 @@ extern void br_fdb_delete_by_port(struct net_bridge *br,
extern struct net_bridge_fdb_entry *br_fdb_get(struct net_bridge *br, extern struct net_bridge_fdb_entry *br_fdb_get(struct net_bridge *br,
unsigned char *addr); unsigned char *addr);
extern void br_fdb_put(struct net_bridge_fdb_entry *ent); extern void br_fdb_put(struct net_bridge_fdb_entry *ent);
extern int br_fdb_get_entries(struct net_bridge *br, extern int br_fdb_fillbuf(struct net_bridge *br, void *buf,
unsigned char *_buf, unsigned long count, unsigned long off);
int maxnum,
int offset);
extern int br_fdb_insert(struct net_bridge *br, extern int br_fdb_insert(struct net_bridge *br,
struct net_bridge_port *source, struct net_bridge_port *source,
const unsigned char *addr, const unsigned char *addr,
......
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