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 union inet_addr {
  16         __u32           all[4];
  17         __be32          ip;
  18         __be32          ip6[4];
  19         struct in_addr  in;
  20         struct in6_addr in6;
  21 };
  22
  23 struct netpoll {
  24         struct net_device *dev;
  25         char dev_name[IFNAMSIZ];
  26         const char *name;
  27         void (*rx_hook)(struct netpoll *, int, char *, int);
  28
  29         union inet_addr local_ip, remote_ip;
  30         bool ipv6;
  31         u16 local_port, remote_port;
  32         u8 remote_mac[ETH_ALEN];
  33
  34         struct list_head rx; /* rx_np list element */
  35         struct work_struct cleanup_work;
  36 };
  37
  38 struct netpoll_info {
  39         atomic_t refcnt;
  40
  41         unsigned long rx_flags;
  42         spinlock_t rx_lock;
  43         struct semaphore dev_lock;
  44         struct list_head rx_np; /* netpolls that registered an rx_hook */
  45
  46         struct sk_buff_head neigh_tx; /* list of neigh requests to reply to */
  47         struct sk_buff_head txq;
  48
  49         struct delayed_work tx_work;
  50
  51         struct netpoll *netpoll;
  52         struct rcu_head rcu;
  53 };
  54
  55 #ifdef CONFIG_NETPOLL
  56 extern int netpoll_rx_disable(struct net_device *dev);
  57 extern void netpoll_rx_enable(struct net_device *dev);
  58 #else
  59 static inline int netpoll_rx_disable(struct net_device *dev) { return 0; }
  60 static inline void netpoll_rx_enable(struct net_device *dev) { return; }
  61 #endif
  62
  63 void netpoll_send_udp(struct netpoll *np, const char *msg, int len);
  64 void netpoll_print_options(struct netpoll *np);
  65 int netpoll_parse_options(struct netpoll *np, char *opt);
  66 int __netpoll_setup(struct netpoll *np, struct net_device *ndev, gfp_t gfp);
  67 int netpoll_setup(struct netpoll *np);
  68 int netpoll_trap(void);
  69 void netpoll_set_trap(int trap);
  70 void __netpoll_cleanup(struct netpoll *np);
  71 void __netpoll_free_async(struct netpoll *np);
  72 void netpoll_cleanup(struct netpoll *np);
  73 int __netpoll_rx(struct sk_buff *skb, struct netpoll_info *npinfo);
  74 void netpoll_send_skb_on_dev(struct netpoll *np, struct sk_buff *skb,
  75                              struct net_device *dev);
  76 static inline void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
  77 {
  78         unsigned long flags;
  79         local_irq_save(flags);
  80         netpoll_send_skb_on_dev(np, skb, np->dev);
  81         local_irq_restore(flags);
  82 }
  83
  84
  85
  86 #ifdef CONFIG_NETPOLL
  87 static inline bool netpoll_rx_on(struct sk_buff *skb)
  88 {
  89         struct netpoll_info *npinfo = rcu_dereference_bh(skb->dev->npinfo);
  90
  91         return npinfo && (!list_empty(&npinfo->rx_np) || npinfo->rx_flags);
  92 }
  93
  94 static inline bool netpoll_rx(struct sk_buff *skb)
  95 {
  96         struct netpoll_info *npinfo;
  97         unsigned long flags;
  98         bool ret = false;
  99
 100         local_irq_save(flags);
 101
 102         if (!netpoll_rx_on(skb))
 103                 goto out;
 104
 105         npinfo = rcu_dereference_bh(skb->dev->npinfo);
 106         spin_lock(&npinfo->rx_lock);
 107         /* check rx_flags again with the lock held */
 108         if (npinfo->rx_flags && __netpoll_rx(skb, npinfo))
 109                 ret = true;
 110         spin_unlock(&npinfo->rx_lock);
 111
 112 out:
 113         local_irq_restore(flags);
 114         return ret;
 115 }
 116
 117 static inline int netpoll_receive_skb(struct sk_buff *skb)
 118 {
 119         if (!list_empty(&skb->dev->napi_list))
 120                 return netpoll_rx(skb);
 121         return 0;
 122 }
 123
 124 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 125 {
 126         struct net_device *dev = napi->dev;
 127
 128         if (dev && dev->npinfo) {
 129                 spin_lock(&napi->poll_lock);
 130                 napi->poll_owner = smp_processor_id();
 131                 return napi;
 132         }
 133         return NULL;
 134 }
 135
 136 static inline void netpoll_poll_unlock(void *have)
 137 {
 138         struct napi_struct *napi = have;
 139
 140         if (napi) {
 141                 napi->poll_owner = -1;
 142                 spin_unlock(&napi->poll_lock);
 143         }
 144 }
 145
 146 static inline bool netpoll_tx_running(struct net_device *dev)
 147 {
 148         return irqs_disabled();
 149 }
 150
 151 #else
 152 static inline bool netpoll_rx(struct sk_buff *skb)
 153 {
 154         return false;
 155 }
 156 static inline bool netpoll_rx_on(struct sk_buff *skb)
 157 {
 158         return false;
 159 }
 160 static inline int netpoll_receive_skb(struct sk_buff *skb)
 161 {
 162         return 0;
 163 }
 164 static inline void *netpoll_poll_lock(struct napi_struct *napi)
 165 {
 166         return NULL;
 167 }
 168 static inline void netpoll_poll_unlock(void *have)
 169 {
 170 }
 171 static inline void netpoll_netdev_init(struct net_device *dev)
 172 {
 173 }
 174 static inline bool netpoll_tx_running(struct net_device *dev)
 175 {
 176         return false;
 177 }
 178 #endif
 179
 180 #endif