xref: /linux-6.15/include/linux/hdlc.h (revision 87c2ce3b)
1 /*
2  * Generic HDLC support routines for Linux
3  *
4  * Copyright (C) 1999-2005 Krzysztof Halasa <[email protected]>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of version 2 of the GNU General Public License
8  * as published by the Free Software Foundation.
9  */
10 
11 #ifndef __HDLC_H
12 #define __HDLC_H
13 
14 #define GENERIC_HDLC_VERSION 4	/* For synchronization with sethdlc utility */
15 
16 #define CLOCK_DEFAULT   0	/* Default setting */
17 #define CLOCK_EXT	1	/* External TX and RX clock - DTE */
18 #define CLOCK_INT	2	/* Internal TX and RX clock - DCE */
19 #define CLOCK_TXINT	3	/* Internal TX and external RX clock */
20 #define CLOCK_TXFROMRX	4	/* TX clock derived from external RX clock */
21 
22 
23 #define ENCODING_DEFAULT	0 /* Default setting */
24 #define ENCODING_NRZ		1
25 #define ENCODING_NRZI		2
26 #define ENCODING_FM_MARK	3
27 #define ENCODING_FM_SPACE	4
28 #define ENCODING_MANCHESTER	5
29 
30 
31 #define PARITY_DEFAULT		0 /* Default setting */
32 #define PARITY_NONE		1 /* No parity */
33 #define PARITY_CRC16_PR0	2 /* CRC16, initial value 0x0000 */
34 #define PARITY_CRC16_PR1	3 /* CRC16, initial value 0xFFFF */
35 #define PARITY_CRC16_PR0_CCITT	4 /* CRC16, initial 0x0000, ITU-T version */
36 #define PARITY_CRC16_PR1_CCITT	5 /* CRC16, initial 0xFFFF, ITU-T version */
37 #define PARITY_CRC32_PR0_CCITT	6 /* CRC32, initial value 0x00000000 */
38 #define PARITY_CRC32_PR1_CCITT	7 /* CRC32, initial value 0xFFFFFFFF */
39 
40 #define LMI_DEFAULT		0 /* Default setting */
41 #define LMI_NONE		1 /* No LMI, all PVCs are static */
42 #define LMI_ANSI		2 /* ANSI Annex D */
43 #define LMI_CCITT		3 /* ITU-T Annex A */
44 #define LMI_CISCO		4 /* The "original" LMI, aka Gang of Four */
45 
46 #define HDLC_MAX_MTU 1500	/* Ethernet 1500 bytes */
47 #define HDLC_MAX_MRU (HDLC_MAX_MTU + 10 + 14 + 4) /* for ETH+VLAN over FR */
48 
49 
50 #ifdef __KERNEL__
51 
52 #include <linux/skbuff.h>
53 #include <linux/netdevice.h>
54 #include <net/syncppp.h>
55 #include <linux/hdlc/ioctl.h>
56 
57 
58 typedef struct {		/* Used in Cisco and PPP mode */
59 	u8 address;
60 	u8 control;
61 	u16 protocol;
62 }__attribute__ ((packed)) hdlc_header;
63 
64 
65 
66 typedef struct {
67 	u32 type;		/* code */
68 	u32 par1;
69 	u32 par2;
70 	u16 rel;		/* reliability */
71 	u32 time;
72 }__attribute__ ((packed)) cisco_packet;
73 #define	CISCO_PACKET_LEN	18
74 #define	CISCO_BIG_PACKET_LEN	20
75 
76 
77 
78 typedef struct pvc_device_struct {
79 	struct net_device *master;
80 	struct net_device *main;
81 	struct net_device *ether; /* bridged Ethernet interface */
82 	struct pvc_device_struct *next;	/* Sorted in ascending DLCI order */
83 	int dlci;
84 	int open_count;
85 
86 	struct {
87 		unsigned int new: 1;
88 		unsigned int active: 1;
89 		unsigned int exist: 1;
90 		unsigned int deleted: 1;
91 		unsigned int fecn: 1;
92 		unsigned int becn: 1;
93 		unsigned int bandwidth;	/* Cisco LMI reporting only */
94 	}state;
95 }pvc_device;
96 
97 
98 
99 typedef struct hdlc_device_struct {
100 	/* To be initialized by hardware driver */
101 	struct net_device_stats stats;
102 
103 	/* used by HDLC layer to take control over HDLC device from hw driver*/
104 	int (*attach)(struct net_device *dev,
105 		      unsigned short encoding, unsigned short parity);
106 
107 	/* hardware driver must handle this instead of dev->hard_start_xmit */
108 	int (*xmit)(struct sk_buff *skb, struct net_device *dev);
109 
110 
111 	/* Things below are for HDLC layer internal use only */
112 	struct {
113 		int (*open)(struct net_device *dev);
114 		void (*close)(struct net_device *dev);
115 
116 		/* if open & DCD */
117 		void (*start)(struct net_device *dev);
118 		/* if open & !DCD */
119 		void (*stop)(struct net_device *dev);
120 
121 		void (*detach)(struct hdlc_device_struct *hdlc);
122 		int (*netif_rx)(struct sk_buff *skb);
123 		unsigned short (*type_trans)(struct sk_buff *skb,
124 					     struct net_device *dev);
125 		int id;		/* IF_PROTO_HDLC/CISCO/FR/etc. */
126 	}proto;
127 
128 	int carrier;
129 	int open;
130 	spinlock_t state_lock;
131 
132 	union {
133 		struct {
134 			fr_proto settings;
135 			pvc_device *first_pvc;
136 			int dce_pvc_count;
137 
138 			struct timer_list timer;
139 			unsigned long last_poll;
140 			int reliable;
141 			int dce_changed;
142 			int request;
143 			int fullrep_sent;
144 			u32 last_errors; /* last errors bit list */
145 			u8 n391cnt;
146 			u8 txseq; /* TX sequence number */
147 			u8 rxseq; /* RX sequence number */
148 		}fr;
149 
150 		struct {
151 			cisco_proto settings;
152 
153 			struct timer_list timer;
154 			unsigned long last_poll;
155 			int up;
156 			int request_sent;
157 			u32 txseq; /* TX sequence number */
158 			u32 rxseq; /* RX sequence number */
159 		}cisco;
160 
161 		struct {
162 			raw_hdlc_proto settings;
163 		}raw_hdlc;
164 
165 		struct {
166 			struct ppp_device pppdev;
167 			struct ppp_device *syncppp_ptr;
168 			int (*old_change_mtu)(struct net_device *dev,
169 					      int new_mtu);
170 		}ppp;
171 	}state;
172 	void *priv;
173 }hdlc_device;
174 
175 
176 
177 int hdlc_raw_ioctl(struct net_device *dev, struct ifreq *ifr);
178 int hdlc_raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr);
179 int hdlc_cisco_ioctl(struct net_device *dev, struct ifreq *ifr);
180 int hdlc_ppp_ioctl(struct net_device *dev, struct ifreq *ifr);
181 int hdlc_fr_ioctl(struct net_device *dev, struct ifreq *ifr);
182 int hdlc_x25_ioctl(struct net_device *dev, struct ifreq *ifr);
183 
184 
185 /* Exported from hdlc.o */
186 
187 /* Called by hardware driver when a user requests HDLC service */
188 int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
189 
190 /* Must be used by hardware driver on module startup/exit */
191 int register_hdlc_device(struct net_device *dev);
192 void unregister_hdlc_device(struct net_device *dev);
193 
194 struct net_device *alloc_hdlcdev(void *priv);
195 
196 static __inline__ hdlc_device* dev_to_hdlc(struct net_device *dev)
197 {
198 	return netdev_priv(dev);
199 }
200 
201 
202 static __inline__ pvc_device* dev_to_pvc(struct net_device *dev)
203 {
204 	return (pvc_device*)dev->priv;
205 }
206 
207 
208 static __inline__ void debug_frame(const struct sk_buff *skb)
209 {
210 	int i;
211 
212 	for (i=0; i < skb->len; i++) {
213 		if (i == 100) {
214 			printk("...\n");
215 			return;
216 		}
217 		printk(" %02X", skb->data[i]);
218 	}
219 	printk("\n");
220 }
221 
222 
223 /* Must be called by hardware driver when HDLC device is being opened */
224 int hdlc_open(struct net_device *dev);
225 /* Must be called by hardware driver when HDLC device is being closed */
226 void hdlc_close(struct net_device *dev);
227 /* Called by hardware driver when DCD line level changes */
228 void hdlc_set_carrier(int on, struct net_device *dev);
229 
230 /* May be used by hardware driver to gain control over HDLC device */
231 static __inline__ void hdlc_proto_detach(hdlc_device *hdlc)
232 {
233 	if (hdlc->proto.detach)
234 		hdlc->proto.detach(hdlc);
235 	hdlc->proto.detach = NULL;
236 }
237 
238 
239 static __inline__ struct net_device_stats *hdlc_stats(struct net_device *dev)
240 {
241 	return &dev_to_hdlc(dev)->stats;
242 }
243 
244 
245 static __inline__ __be16 hdlc_type_trans(struct sk_buff *skb,
246 					 struct net_device *dev)
247 {
248 	hdlc_device *hdlc = dev_to_hdlc(dev);
249 
250 	skb->mac.raw  = skb->data;
251 	skb->dev      = dev;
252 
253 	if (hdlc->proto.type_trans)
254 		return hdlc->proto.type_trans(skb, dev);
255 	else
256 		return htons(ETH_P_HDLC);
257 }
258 
259 #endif /* __KERNEL */
260 #endif /* __HDLC_H */
261