1 /* 2 * Routines to manage notifier chains for passing status changes to any 3 * interested routines. We need this instead of hard coded call lists so 4 * that modules can poke their nose into the innards. The network devices 5 * needed them so here they are for the rest of you. 6 * 7 * Alan Cox <Alan.Cox@linux.org> 8 */ 9 10 #ifndef _LINUX_NOTIFIER_H 11 #define _LINUX_NOTIFIER_H 12 #include <linux/errno.h> 13 14 struct notifier_block 15 { 16 int (*notifier_call)(struct notifier_block *self, unsigned long, void *); 17 struct notifier_block *next; 18 int priority; 19 }; 20 21 22 #ifdef __KERNEL__ 23 24 extern int notifier_chain_register(struct notifier_block **list, struct notifier_block *n); 25 extern int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n); 26 extern int notifier_call_chain(struct notifier_block **n, unsigned long val, void *v); 27 28 #define NOTIFY_DONE 0x0000 /* Don't care */ 29 #define NOTIFY_OK 0x0001 /* Suits me */ 30 #define NOTIFY_STOP_MASK 0x8000 /* Don't call further */ 31 #define NOTIFY_BAD (NOTIFY_STOP_MASK|0x0002) /* Bad/Veto action */ 32 33 /* 34 * Declared notifiers so far. I can imagine quite a few more chains 35 * over time (eg laptop power reset chains, reboot chain (to clean 36 * device units up), device [un]mount chain, module load/unload chain, 37 * low memory chain, screenblank chain (for plug in modular screenblankers) 38 * VC switch chains (for loadable kernel svgalib VC switch helpers) etc... 39 */ 40 41 /* netdevice notifier chain */ 42 #define NETDEV_UP 0x0001 /* For now you can't veto a device up/down */ 43 #define NETDEV_DOWN 0x0002 44 #define NETDEV_REBOOT 0x0003 /* Tell a protocol stack a network interface 45 detected a hardware crash and restarted 46 - we can use this eg to kick tcp sessions 47 once done */ 48 #define NETDEV_CHANGE 0x0004 /* Notify device state change */ 49 #define NETDEV_REGISTER 0x0005 50 #define NETDEV_UNREGISTER 0x0006 51 #define NETDEV_CHANGEMTU 0x0007 52 #define NETDEV_CHANGEADDR 0x0008 53 #define NETDEV_GOING_DOWN 0x0009 54 #define NETDEV_CHANGENAME 0x000A 55 56 #define SYS_DOWN 0x0001 /* Notify of system down */ 57 #define SYS_RESTART SYS_DOWN 58 #define SYS_HALT 0x0002 /* Notify of system halt */ 59 #define SYS_POWER_OFF 0x0003 /* Notify of system power off */ 60 61 #define NETLINK_URELEASE 0x0001 /* Unicast netlink socket released */ 62 63 #endif /* __KERNEL__ */ 64 #endif /* _LINUX_NOTIFIER_H */ 65