ARM 嵌入式 系统 设计与实例开发 实验教材 二源码

				/*				 *	X.25 Packet Layer release 002				 *				 *	This is ALPHA test software. This code may break your machine, randomly fail to work with new 				 *	releases, misbehave and/or generally screw up. It might even work. 				 *				 *	This code REQUIRES 2.1.15 or higher				 *				 *	This module:				 *		This module is free software; you can redistribute it and/or				 *		modify it under the terms of the GNU General Public License				 *		as published by the Free Software Foundation; either version				 *		2 of the License, or (at your option) any later version.				 *				 *	History				 *	X.25 001	Jonathan Naylor	Started coding.				 */								#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 				#include 	/* For TIOCINQ/OUTQ */				#include 				#include 				#include 				#include 				#include 								static struct x25_route *x25_route_list /* = NULL initially */;								/*				 *	Add a new route.				 */				static int x25_add_route(x25_address *address, unsigned int sigdigits, struct net_device *dev)				{					struct x25_route *x25_route;					unsigned long flags;									for (x25_route = x25_route_list; x25_route != NULL; x25_route = x25_route->next)						if (memcmp(&x25_route->address, address, sigdigits) == 0 && x25_route->sigdigits == sigdigits)							return -EINVAL;									if ((x25_route = kmalloc(sizeof(*x25_route), GFP_ATOMIC)) == NULL)						return -ENOMEM;									strcpy(x25_route->address.x25_addr, "000000000000000");					memcpy(x25_route->address.x25_addr, address->x25_addr, sigdigits);									x25_route->sigdigits = sigdigits;					x25_route->dev       = dev;									save_flags(flags); cli();					x25_route->next = x25_route_list;					x25_route_list  = x25_route;					restore_flags(flags);									return 0;				}								static void x25_remove_route(struct x25_route *x25_route)				{					struct x25_route *s;					unsigned long flags;									save_flags(flags);					cli();									if ((s = x25_route_list) == x25_route) {						x25_route_list = x25_route->next;						restore_flags(flags);						kfree(x25_route);						return;					}									while (s != NULL && s->next != NULL) {						if (s->next == x25_route) {							s->next = x25_route->next;							restore_flags(flags);							kfree(x25_route);							return;						}										s = s->next;					}									restore_flags(flags);				}								static int x25_del_route(x25_address *address, unsigned int sigdigits, struct net_device *dev)				{					struct x25_route *x25_route;									for (x25_route = x25_route_list; x25_route != NULL; x25_route = x25_route->next) {						if (memcmp(&x25_route->address, address, sigdigits) == 0 && x25_route->sigdigits == sigdigits && x25_route->dev == dev) {							x25_remove_route(x25_route);							return 0;						}					}									return -EINVAL;				}								/*				 *	A device has been removed, remove its routes.				 */				void x25_route_device_down(struct net_device *dev)				{					struct x25_route *route, *x25_route = x25_route_list;									while (x25_route != NULL) {						route     = x25_route;						x25_route = x25_route->next;										if (route->dev == dev)							x25_remove_route(route);					}				}								/*				 *	Check that the device given is a valid X.25 interface that is "up".				 */				struct net_device *x25_dev_get(char *devname)				{					struct net_device *dev;									if ((dev = dev_get_by_name(devname)) == NULL)						return NULL;									if ((dev->flags & IFF_UP) && (dev->type == ARPHRD_X25				#if defined(CONFIG_LLC) || defined(CONFIG_LLC_MODULE)					   || dev->type == ARPHRD_ETHER				#endif					   ))						return dev;									dev_put(dev);									return NULL;				}								/*				 *	Find a device given an X.25 address.				 */				struct net_device *x25_get_route(x25_address *addr)				{					struct x25_route *route, *use = NULL;									for (route = x25_route_list; route != NULL; route = route->next) {						if (memcmp(&route->address, addr, route->sigdigits) == 0) {							if (use == NULL) {								use = route;							} else {								if (route->sigdigits > use->sigdigits)									use = route;							}						}					}									return (use != NULL) ? use->dev : NULL;				}								/*				 *	Handle the ioctls that control the routing functions.				 */				int x25_route_ioctl(unsigned int cmd, void *arg)				{					struct x25_route_struct x25_route;					struct net_device *dev;					int err;									switch (cmd) {										case SIOCADDRT:							if (copy_from_user(&x25_route, arg, sizeof(struct x25_route_struct)))								return -EFAULT;							if (x25_route.sigdigits < 0 || x25_route.sigdigits > 15)								return -EINVAL;							if ((dev = x25_dev_get(x25_route.device)) == NULL)								return -EINVAL;							err = x25_add_route(&x25_route.address, x25_route.sigdigits, dev);							dev_put(dev);							return err;										case SIOCDELRT:							if (copy_from_user(&x25_route, arg, sizeof(struct x25_route_struct)))								return -EFAULT;							if (x25_route.sigdigits < 0 || x25_route.sigdigits > 15)								return -EINVAL;							if ((dev = x25_dev_get(x25_route.device)) == NULL)								return -EINVAL;							err = x25_del_route(&x25_route.address, x25_route.sigdigits, dev);							dev_put(dev);							return err;										default:							return -EINVAL;					}									return 0;				}								int x25_routes_get_info(char *buffer, char **start, off_t offset, int length)				{					struct x25_route *x25_route;					int len     = 0;					off_t pos   = 0;					off_t begin = 0;									cli();									len += sprintf(buffer, "address          digits  device\n");									for (x25_route = x25_route_list; x25_route != NULL; x25_route = x25_route->next) {						len += sprintf(buffer + len, "%-15s  %-6d  %-5s\n",							x25_route->address.x25_addr,							x25_route->sigdigits,							(x25_route->dev != NULL) ? x25_route->dev->name : "???");										pos = begin + len;										if (pos < offset) {							len   = 0;							begin = pos;						}										if (pos > offset + length)							break;					}									sti();									*start = buffer + (offset - begin);					len   -= (offset - begin);									if (len > length) len = length;									return len;				} 								/*				 *	Release all memory associated with X.25 routing structures.				 */				void __exit x25_route_free(void)				{					struct x25_route *route, *x25_route = x25_route_list;									while (x25_route != NULL) {						route     = x25_route;						x25_route = x25_route->next;										x25_remove_route(route);					}				}