![Stephen Hemminger](/assets/img/avatar_default.png)
After looking harder, Steve noticed that the netpoll beast leaked a little every time it shutdown for a nap. Not a big leak, but a nuisance kind of thing. He took out his refcount duct tape and patched the leak. It was overkill since there was already other locking in that area, but it looked clean and wouldn't attract fleas. Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
96 lines
2.2 KiB
C
96 lines
2.2 KiB
C
/*
|
|
* Common code for low-level network console, dump, and debugger code
|
|
*
|
|
* Derived from netconsole, kgdb-over-ethernet, and netdump patches
|
|
*/
|
|
|
|
#ifndef _LINUX_NETPOLL_H
|
|
#define _LINUX_NETPOLL_H
|
|
|
|
#include <linux/netdevice.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/rcupdate.h>
|
|
#include <linux/list.h>
|
|
|
|
struct netpoll;
|
|
|
|
struct netpoll {
|
|
struct net_device *dev;
|
|
char dev_name[16], *name;
|
|
void (*rx_hook)(struct netpoll *, int, char *, int);
|
|
void (*drop)(struct sk_buff *skb);
|
|
u32 local_ip, remote_ip;
|
|
u16 local_port, remote_port;
|
|
unsigned char local_mac[6], remote_mac[6];
|
|
};
|
|
|
|
struct netpoll_info {
|
|
atomic_t refcnt;
|
|
spinlock_t poll_lock;
|
|
int poll_owner;
|
|
int tries;
|
|
int rx_flags;
|
|
spinlock_t rx_lock;
|
|
struct netpoll *rx_np; /* netpoll that registered an rx_hook */
|
|
struct sk_buff_head arp_tx; /* list of arp requests to reply to */
|
|
};
|
|
|
|
void netpoll_poll(struct netpoll *np);
|
|
void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
|
|
int netpoll_parse_options(struct netpoll *np, char *opt);
|
|
int netpoll_setup(struct netpoll *np);
|
|
int netpoll_trap(void);
|
|
void netpoll_set_trap(int trap);
|
|
void netpoll_cleanup(struct netpoll *np);
|
|
int __netpoll_rx(struct sk_buff *skb);
|
|
void netpoll_queue(struct sk_buff *skb);
|
|
|
|
#ifdef CONFIG_NETPOLL
|
|
static inline int netpoll_rx(struct sk_buff *skb)
|
|
{
|
|
struct netpoll_info *npinfo = skb->dev->npinfo;
|
|
unsigned long flags;
|
|
int ret = 0;
|
|
|
|
if (!npinfo || (!npinfo->rx_np && !npinfo->rx_flags))
|
|
return 0;
|
|
|
|
spin_lock_irqsave(&npinfo->rx_lock, flags);
|
|
/* check rx_flags again with the lock held */
|
|
if (npinfo->rx_flags && __netpoll_rx(skb))
|
|
ret = 1;
|
|
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static inline void *netpoll_poll_lock(struct net_device *dev)
|
|
{
|
|
rcu_read_lock(); /* deal with race on ->npinfo */
|
|
if (dev->npinfo) {
|
|
spin_lock(&dev->npinfo->poll_lock);
|
|
dev->npinfo->poll_owner = smp_processor_id();
|
|
return dev->npinfo;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static inline void netpoll_poll_unlock(void *have)
|
|
{
|
|
struct netpoll_info *npi = have;
|
|
|
|
if (npi) {
|
|
npi->poll_owner = -1;
|
|
spin_unlock(&npi->poll_lock);
|
|
}
|
|
rcu_read_unlock();
|
|
}
|
|
|
|
#else
|
|
#define netpoll_rx(a) 0
|
|
#define netpoll_poll_lock(a) NULL
|
|
#define netpoll_poll_unlock(a)
|
|
#endif
|
|
|
|
#endif
|