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 14struct 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 24extern int notifier_chain_register(struct notifier_block **list, struct notifier_block *n); 25extern int notifier_chain_unregister(struct notifier_block **nl, struct notifier_block *n); 26extern 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