include/linux/netpoll.h

   1 /*
   2  * Common code for low-level network console, dump, and debugger code
   3  *
   4  * Derived from netconsole, kgdb-over-ethernet, and netdump patches
   5  */
   6
   7 #ifndef _LINUX_NETPOLL_H
   8 #define _LINUX_NETPOLL_H
   9
  10 #include <linux/netdevice.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/rcupdate.h>
  13 #include <linux/list.h>
  14
  15 struct netpoll;
  16
  17 struct netpoll {
  18         struct net_device *dev;
  19         char dev_name[16], *name;
  20         void (*rx_hook)(struct netpoll *, int, char *, int);
  21         void (*drop)(struct sk_buff *skb);
  22         u32 local_ip, remote_ip;
  23         u16 local_port, remote_port;
  24         unsigned char local_mac[6], remote_mac[6];
  25 };
  26
  27 struct netpoll_info {
  28         spinlock_t poll_lock;
  29         int poll_owner;
  30         int tries;
  31         int rx_flags;
  32         spinlock_t rx_lock;
  33         struct netpoll *rx_np; /* netpoll that registered an rx_hook */
  34         struct sk_buff_head arp_tx; /* list of arp requests to reply to */
  35 };
  36
  37 void netpoll_poll(struct netpoll *np);
  38 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
  39 int netpoll_parse_options(struct netpoll *np, char *opt);
  40 int netpoll_setup(struct netpoll *np);
  41 int netpoll_trap(void);
  42 void netpoll_set_trap(int trap);
  43 void netpoll_cleanup(struct netpoll *np);
  44 int __netpoll_rx(struct sk_buff *skb);
  45 void netpoll_queue(struct sk_buff *skb);
  46
  47 #ifdef CONFIG_NETPOLL
  48 static inline int netpoll_rx(struct sk_buff *skb)
  49 {
  50         struct netpoll_info *npinfo = skb->dev->npinfo;
  51         unsigned long flags;
  52         int ret = 0;
  53
  54         if (!npinfo || (!npinfo->rx_np && !npinfo->rx_flags))
  55                 return 0;
  56
  57         spin_lock_irqsave(&npinfo->rx_lock, flags);
  58         /* check rx_flags again with the lock held */
  59         if (npinfo->rx_flags && __netpoll_rx(skb))
  60                 ret = 1;
  61         spin_unlock_irqrestore(&npinfo->rx_lock, flags);
  62
  63         return ret;
  64 }
  65
  66 static inline void *netpoll_poll_lock(struct net_device *dev)
  67 {
  68         rcu_read_lock(); /* deal with race on ->npinfo */
  69         if (dev->npinfo) {
  70                 spin_lock(&dev->npinfo->poll_lock);
  71                 dev->npinfo->poll_owner = smp_processor_id();
  72                 return dev->npinfo;
  73         }
  74         return NULL;
  75 }
  76
  77 static inline void netpoll_poll_unlock(void *have)
  78 {
  79         struct netpoll_info *npi = have;
  80
  81         if (npi) {
  82                 npi->poll_owner = -1;
  83                 spin_unlock(&npi->poll_lock);
  84         }
  85         rcu_read_unlock();
  86 }
  87
  88 #else
  89 #define netpoll_rx(a) 0
  90 #define netpoll_poll_lock(a) NULL
  91 #define netpoll_poll_unlock(a)
  92 #endif
  93
  94 #endif