projects/linux·blob master · refs

438 lines · 14.2 KiB

1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef LLC_PDU_H
3#define LLC_PDU_H
4/*
5 * Copyright (c) 1997 by Procom Technology,Inc.
6 * 2001-2003 by Arnaldo Carvalho de Melo <[email protected]>
7 */
8
9#include <linux/if_ether.h>
10
11/* Lengths of frame formats */
12#define LLC_PDU_LEN_I 4 /* header and 2 control bytes */
13#define LLC_PDU_LEN_S 4
14#define LLC_PDU_LEN_U 3 /* header and 1 control byte */
15/* header and 1 control byte and XID info */
16#define LLC_PDU_LEN_U_XID (LLC_PDU_LEN_U + sizeof(struct llc_xid_info))
17/* Known SAP addresses */
18#define LLC_GLOBAL_SAP 0xFF
19#define LLC_NULL_SAP 0x00 /* not network-layer visible */
20#define LLC_MGMT_INDIV 0x02 /* station LLC mgmt indiv addr */
21#define LLC_MGMT_GRP 0x03 /* station LLC mgmt group addr */
22#define LLC_RDE_SAP 0xA6 /* route ... */
23
24/* SAP field bit masks */
25#define LLC_ISO_RESERVED_SAP 0x02
26#define LLC_SAP_GROUP_DSAP 0x01
27#define LLC_SAP_RESP_SSAP 0x01
28
29/* Group/individual DSAP indicator is DSAP field */
30#define LLC_PDU_GROUP_DSAP_MASK 0x01
31#define LLC_PDU_IS_GROUP_DSAP(pdu) \
32 ((pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1)
33#define LLC_PDU_IS_INDIV_DSAP(pdu) \
34 (!(pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1)
35
36/* Command/response PDU indicator in SSAP field */
37#define LLC_PDU_CMD_RSP_MASK 0x01
38#define LLC_PDU_CMD 0
39#define LLC_PDU_RSP 1
40#define LLC_PDU_IS_CMD(pdu) ((pdu->ssap & LLC_PDU_RSP) ? 0 : 1)
41#define LLC_PDU_IS_RSP(pdu) ((pdu->ssap & LLC_PDU_RSP) ? 1 : 0)
42
43/* Get PDU type from 2 lowest-order bits of control field first byte */
44#define LLC_PDU_TYPE_I_MASK 0x01 /* 16-bit control field */
45#define LLC_PDU_TYPE_S_MASK 0x03
46#define LLC_PDU_TYPE_U_MASK 0x03 /* 8-bit control field */
47#define LLC_PDU_TYPE_MASK 0x03
48
49#define LLC_PDU_TYPE_I 0 /* first bit */
50#define LLC_PDU_TYPE_S 1 /* first two bits */
51#define LLC_PDU_TYPE_U 3 /* first two bits */
52#define LLC_PDU_TYPE_U_XID 4 /* private type for detecting XID commands */
53
54#define LLC_PDU_TYPE_IS_I(pdu) \
55 ((!(pdu->ctrl_1 & LLC_PDU_TYPE_I_MASK)) ? 1 : 0)
56
57#define LLC_PDU_TYPE_IS_U(pdu) \
58 (((pdu->ctrl_1 & LLC_PDU_TYPE_U_MASK) == LLC_PDU_TYPE_U) ? 1 : 0)
59
60#define LLC_PDU_TYPE_IS_S(pdu) \
61 (((pdu->ctrl_1 & LLC_PDU_TYPE_S_MASK) == LLC_PDU_TYPE_S) ? 1 : 0)
62
63/* U-format PDU control field masks */
64#define LLC_U_PF_BIT_MASK 0x10 /* P/F bit mask */
65#define LLC_U_PF_IS_1(pdu) ((pdu->ctrl_1 & LLC_U_PF_BIT_MASK) ? 1 : 0)
66#define LLC_U_PF_IS_0(pdu) ((!(pdu->ctrl_1 & LLC_U_PF_BIT_MASK)) ? 1 : 0)
67
68#define LLC_U_PDU_CMD_MASK 0xEC /* cmd/rsp mask */
69#define LLC_U_PDU_CMD(pdu) (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK)
70#define LLC_U_PDU_RSP(pdu) (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK)
71
72#define LLC_1_PDU_CMD_UI 0x00 /* Type 1 cmds/rsps */
73#define LLC_1_PDU_CMD_XID 0xAC
74#define LLC_1_PDU_CMD_TEST 0xE0
75
76#define LLC_2_PDU_CMD_SABME 0x6C /* Type 2 cmds/rsps */
77#define LLC_2_PDU_CMD_DISC 0x40
78#define LLC_2_PDU_RSP_UA 0x60
79#define LLC_2_PDU_RSP_DM 0x0C
80#define LLC_2_PDU_RSP_FRMR 0x84
81
82/* Type 1 operations */
83
84/* XID information field bit masks */
85
86/* LLC format identifier (byte 1) */
87#define LLC_XID_FMT_ID 0x81 /* first byte must be this */
88
89/* LLC types/classes identifier (byte 2) */
90#define LLC_XID_CLASS_ZEROS_MASK 0xE0 /* these must be zeros */
91#define LLC_XID_CLASS_MASK 0x1F /* AND with byte to get below */
92
93#define LLC_XID_NULL_CLASS_1 0x01 /* if NULL LSAP...use these */
94#define LLC_XID_NULL_CLASS_2 0x03
95#define LLC_XID_NULL_CLASS_3 0x05
96#define LLC_XID_NULL_CLASS_4 0x07
97
98#define LLC_XID_NNULL_TYPE_1 0x01 /* if non-NULL LSAP...use these */
99#define LLC_XID_NNULL_TYPE_2 0x02
100#define LLC_XID_NNULL_TYPE_3 0x04
101#define LLC_XID_NNULL_TYPE_1_2 0x03
102#define LLC_XID_NNULL_TYPE_1_3 0x05
103#define LLC_XID_NNULL_TYPE_2_3 0x06
104#define LLC_XID_NNULL_ALL 0x07
105
106/* Sender Receive Window (byte 3) */
107#define LLC_XID_RW_MASK 0xFE /* AND with value to get below */
108
109#define LLC_XID_MIN_RW 0x02 /* lowest-order bit always zero */
110
111/* Type 2 operations */
112
113#define LLC_2_SEQ_NBR_MODULO ((u8) 128)
114
115/* I-PDU masks ('ctrl' is I-PDU control word) */
116#define LLC_I_GET_NS(pdu) (u8)((pdu->ctrl_1 & 0xFE) >> 1)
117#define LLC_I_GET_NR(pdu) (u8)((pdu->ctrl_2 & 0xFE) >> 1)
118
119#define LLC_I_PF_BIT_MASK 0x01
120
121#define LLC_I_PF_IS_0(pdu) ((!(pdu->ctrl_2 & LLC_I_PF_BIT_MASK)) ? 1 : 0)
122#define LLC_I_PF_IS_1(pdu) ((pdu->ctrl_2 & LLC_I_PF_BIT_MASK) ? 1 : 0)
123
124/* S-PDU supervisory commands and responses */
125
126#define LLC_S_PDU_CMD_MASK 0x0C
127#define LLC_S_PDU_CMD(pdu) (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK)
128#define LLC_S_PDU_RSP(pdu) (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK)
129
130#define LLC_2_PDU_CMD_RR 0x00 /* rx ready cmd */
131#define LLC_2_PDU_RSP_RR 0x00 /* rx ready rsp */
132#define LLC_2_PDU_CMD_REJ 0x08 /* reject PDU cmd */
133#define LLC_2_PDU_RSP_REJ 0x08 /* reject PDU rsp */
134#define LLC_2_PDU_CMD_RNR 0x04 /* rx not ready cmd */
135#define LLC_2_PDU_RSP_RNR 0x04 /* rx not ready rsp */
136
137#define LLC_S_PF_BIT_MASK 0x01
138#define LLC_S_PF_IS_0(pdu) ((!(pdu->ctrl_2 & LLC_S_PF_BIT_MASK)) ? 1 : 0)
139#define LLC_S_PF_IS_1(pdu) ((pdu->ctrl_2 & LLC_S_PF_BIT_MASK) ? 1 : 0)
140
141#define PDU_SUPV_GET_Nr(pdu) ((pdu->ctrl_2 & 0xFE) >> 1)
142#define PDU_GET_NEXT_Vr(sn) (((sn) + 1) & ~LLC_2_SEQ_NBR_MODULO)
143
144/* FRMR information field macros */
145
146#define FRMR_INFO_LENGTH 5 /* 5 bytes of information */
147
148/*
149 * info is pointer to FRMR info field structure; 'rej_ctrl' is byte pointer
150 * (if U-PDU) or word pointer to rejected PDU control field
151 */
152#define FRMR_INFO_SET_REJ_CNTRL(info,rej_ctrl) \
153 info->rej_pdu_ctrl = ((*((u8 *) rej_ctrl) & \
154 LLC_PDU_TYPE_U) != LLC_PDU_TYPE_U ? \
155 (u16)*((u16 *) rej_ctrl) : \
156 (((u16) *((u8 *) rej_ctrl)) & 0x00FF))
157
158/*
159 * Info is pointer to FRMR info field structure; 'vs' is a byte containing
160 * send state variable value in low-order 7 bits (insure the lowest-order
161 * bit remains zero (0))
162 */
163#define FRMR_INFO_SET_Vs(info,vs) (info->curr_ssv = (((u8) vs) << 1))
164#define FRMR_INFO_SET_Vr(info,vr) (info->curr_rsv = (((u8) vr) << 1))
165
166/*
167 * Info is pointer to FRMR info field structure; 'cr' is a byte containing
168 * the C/R bit value in the low-order bit
169 */
170#define FRMR_INFO_SET_C_R_BIT(info, cr) (info->curr_rsv |= (((u8) cr) & 0x01))
171
172/*
173 * In the remaining five macros, 'info' is pointer to FRMR info field
174 * structure; 'ind' is a byte containing the bit value to set in the
175 * lowest-order bit)
176 */
177#define FRMR_INFO_SET_INVALID_PDU_CTRL_IND(info, ind) \
178 (info->ind_bits = ((info->ind_bits & 0xFE) | (((u8) ind) & 0x01)))
179
180#define FRMR_INFO_SET_INVALID_PDU_INFO_IND(info, ind) \
181 (info->ind_bits = ( (info->ind_bits & 0xFD) | (((u8) ind) & 0x02)))
182
183#define FRMR_INFO_SET_PDU_INFO_2LONG_IND(info, ind) \
184 (info->ind_bits = ( (info->ind_bits & 0xFB) | (((u8) ind) & 0x04)))
185
186#define FRMR_INFO_SET_PDU_INVALID_Nr_IND(info, ind) \
187 (info->ind_bits = ( (info->ind_bits & 0xF7) | (((u8) ind) & 0x08)))
188
189#define FRMR_INFO_SET_PDU_INVALID_Ns_IND(info, ind) \
190 (info->ind_bits = ( (info->ind_bits & 0xEF) | (((u8) ind) & 0x10)))
191
192/* Sequence-numbered PDU format (4 bytes in length) */
193struct llc_pdu_sn {
194 u8 dsap;
195 u8 ssap;
196 u8 ctrl_1;
197 u8 ctrl_2;
198} __packed;
199
200static inline struct llc_pdu_sn *llc_pdu_sn_hdr(struct sk_buff *skb)
201{
202 return (struct llc_pdu_sn *)skb_network_header(skb);
203}
204
205/* Un-numbered PDU format (3 bytes in length) */
206struct llc_pdu_un {
207 u8 dsap;
208 u8 ssap;
209 u8 ctrl_1;
210} __packed;
211
212static inline struct llc_pdu_un *llc_pdu_un_hdr(struct sk_buff *skb)
213{
214 return (struct llc_pdu_un *)skb_network_header(skb);
215}
216
217/**
218 * llc_pdu_header_init - initializes pdu header
219 * @skb: input skb that header must be set into it.
220 * @type: type of PDU (U, I or S).
221 * @ssap: source sap.
222 * @dsap: destination sap.
223 * @cr: command/response bit (0 or 1).
224 *
225 * This function sets DSAP, SSAP and command/Response bit in LLC header.
226 */
227static inline void llc_pdu_header_init(struct sk_buff *skb, u8 type,
228 u8 ssap, u8 dsap, u8 cr)
229{
230 int hlen = 4; /* default value for I and S types */
231 struct llc_pdu_un *pdu;
232
233 switch (type) {
234 case LLC_PDU_TYPE_U:
235 hlen = 3;
236 break;
237 case LLC_PDU_TYPE_U_XID:
238 hlen = 6;
239 break;
240 }
241
242 skb_push(skb, hlen);
243 skb_reset_network_header(skb);
244 pdu = llc_pdu_un_hdr(skb);
245 pdu->dsap = dsap;
246 pdu->ssap = ssap;
247 pdu->ssap |= cr;
248}
249
250/**
251 * llc_pdu_decode_sa - extracts, source address (MAC) of input frame
252 * @skb: input skb that source address must be extracted from it.
253 * @sa: pointer to source address (6 byte array).
254 *
255 * This function extracts source address(MAC) of input frame.
256 */
257static inline void llc_pdu_decode_sa(struct sk_buff *skb, u8 *sa)
258{
259 memcpy(sa, eth_hdr(skb)->h_source, ETH_ALEN);
260}
261
262/**
263 * llc_pdu_decode_da - extracts dest address of input frame
264 * @skb: input skb that destination address must be extracted from it
265 * @da: pointer to destination address (6 byte array).
266 *
267 * This function extracts destination address(MAC) of input frame.
268 */
269static inline void llc_pdu_decode_da(struct sk_buff *skb, u8 *da)
270{
271 memcpy(da, eth_hdr(skb)->h_dest, ETH_ALEN);
272}
273
274/**
275 * llc_pdu_decode_ssap - extracts source SAP of input frame
276 * @skb: input skb that source SAP must be extracted from it.
277 * @ssap: source SAP (output argument).
278 *
279 * This function extracts source SAP of input frame. Right bit of SSAP is
280 * command/response bit.
281 */
282static inline void llc_pdu_decode_ssap(struct sk_buff *skb, u8 *ssap)
283{
284 *ssap = llc_pdu_un_hdr(skb)->ssap & 0xFE;
285}
286
287/**
288 * llc_pdu_decode_dsap - extracts dest SAP of input frame
289 * @skb: input skb that destination SAP must be extracted from it.
290 * @dsap: destination SAP (output argument).
291 *
292 * This function extracts destination SAP of input frame. right bit of
293 * DSAP designates individual/group SAP.
294 */
295static inline void llc_pdu_decode_dsap(struct sk_buff *skb, u8 *dsap)
296{
297 *dsap = llc_pdu_un_hdr(skb)->dsap & 0xFE;
298}
299
300/**
301 * llc_pdu_init_as_ui_cmd - sets LLC header as UI PDU
302 * @skb: input skb that header must be set into it.
303 *
304 * This function sets third byte of LLC header as a UI PDU.
305 */
306static inline void llc_pdu_init_as_ui_cmd(struct sk_buff *skb)
307{
308 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
309
310 pdu->ctrl_1 = LLC_PDU_TYPE_U;
311 pdu->ctrl_1 |= LLC_1_PDU_CMD_UI;
312}
313
314/**
315 * llc_pdu_init_as_test_cmd - sets PDU as TEST
316 * @skb: Address of the skb to build
317 *
318 * Sets a PDU as TEST
319 */
320static inline void llc_pdu_init_as_test_cmd(struct sk_buff *skb)
321{
322 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
323
324 pdu->ctrl_1 = LLC_PDU_TYPE_U;
325 pdu->ctrl_1 |= LLC_1_PDU_CMD_TEST;
326 pdu->ctrl_1 |= LLC_U_PF_BIT_MASK;
327}
328
329/**
330 * llc_pdu_init_as_test_rsp - build TEST response PDU
331 * @skb: Address of the skb to build
332 * @ev_skb: The received TEST command PDU frame
333 *
334 * Builds a pdu frame as a TEST response.
335 */
336static inline void llc_pdu_init_as_test_rsp(struct sk_buff *skb,
337 struct sk_buff *ev_skb)
338{
339 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
340
341 pdu->ctrl_1 = LLC_PDU_TYPE_U;
342 pdu->ctrl_1 |= LLC_1_PDU_CMD_TEST;
343 pdu->ctrl_1 |= LLC_U_PF_BIT_MASK;
344 if (ev_skb->protocol == htons(ETH_P_802_2)) {
345 struct llc_pdu_un *ev_pdu = llc_pdu_un_hdr(ev_skb);
346 int dsize;
347
348 dsize = ntohs(eth_hdr(ev_skb)->h_proto) - 3;
349 memcpy(((u8 *)pdu) + 3, ((u8 *)ev_pdu) + 3, dsize);
350 skb_put(skb, dsize);
351 }
352}
353
354/* LLC Type 1 XID command/response information fields format */
355struct llc_xid_info {
356 u8 fmt_id; /* always 0x81 for LLC */
357 u8 type; /* different if NULL/non-NULL LSAP */
358 u8 rw; /* sender receive window */
359} __packed;
360
361/**
362 * llc_pdu_init_as_xid_cmd - sets bytes 3, 4 & 5 of LLC header as XID
363 * @skb: input skb that header must be set into it.
364 * @svcs_supported: The class of the LLC (I or II)
365 * @rx_window: The size of the receive window of the LLC
366 *
367 * This function sets third,fourth,fifth and sixth bytes of LLC header as
368 * a XID PDU.
369 */
370static inline void llc_pdu_init_as_xid_cmd(struct sk_buff *skb,
371 u8 svcs_supported, u8 rx_window)
372{
373 struct llc_xid_info *xid_info;
374 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
375
376 pdu->ctrl_1 = LLC_PDU_TYPE_U;
377 pdu->ctrl_1 |= LLC_1_PDU_CMD_XID;
378 pdu->ctrl_1 |= LLC_U_PF_BIT_MASK;
379 xid_info = (struct llc_xid_info *)(((u8 *)&pdu->ctrl_1) + 1);
380 xid_info->fmt_id = LLC_XID_FMT_ID; /* 0x81 */
381 xid_info->type = svcs_supported;
382 xid_info->rw = rx_window << 1; /* size of receive window */
383
384 /* no need to push/put since llc_pdu_header_init() has already
385 * pushed 3 + 3 bytes
386 */
387}
388
389/**
390 * llc_pdu_init_as_xid_rsp - builds XID response PDU
391 * @skb: Address of the skb to build
392 * @svcs_supported: The class of the LLC (I or II)
393 * @rx_window: The size of the receive window of the LLC
394 *
395 * Builds a pdu frame as an XID response.
396 */
397static inline void llc_pdu_init_as_xid_rsp(struct sk_buff *skb,
398 u8 svcs_supported, u8 rx_window)
399{
400 struct llc_xid_info *xid_info;
401 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
402
403 pdu->ctrl_1 = LLC_PDU_TYPE_U;
404 pdu->ctrl_1 |= LLC_1_PDU_CMD_XID;
405 pdu->ctrl_1 |= LLC_U_PF_BIT_MASK;
406
407 xid_info = (struct llc_xid_info *)(((u8 *)&pdu->ctrl_1) + 1);
408 xid_info->fmt_id = LLC_XID_FMT_ID;
409 xid_info->type = svcs_supported;
410 xid_info->rw = rx_window << 1;
411 skb_put(skb, sizeof(struct llc_xid_info));
412}
413
414/* LLC Type 2 FRMR response information field format */
415struct llc_frmr_info {
416 u16 rej_pdu_ctrl; /* bits 1-8 if U-PDU */
417 u8 curr_ssv; /* current send state variable val */
418 u8 curr_rsv; /* current receive state variable */
419 u8 ind_bits; /* indicator bits set with macro */
420} __packed;
421
422void llc_pdu_set_cmd_rsp(struct sk_buff *skb, u8 type);
423void llc_pdu_set_pf_bit(struct sk_buff *skb, u8 bit_value);
424void llc_pdu_decode_pf_bit(struct sk_buff *skb, u8 *pf_bit);
425void llc_pdu_init_as_disc_cmd(struct sk_buff *skb, u8 p_bit);
426void llc_pdu_init_as_i_cmd(struct sk_buff *skb, u8 p_bit, u8 ns, u8 nr);
427void llc_pdu_init_as_rej_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
428void llc_pdu_init_as_rnr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
429void llc_pdu_init_as_rr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
430void llc_pdu_init_as_sabme_cmd(struct sk_buff *skb, u8 p_bit);
431void llc_pdu_init_as_dm_rsp(struct sk_buff *skb, u8 f_bit);
432void llc_pdu_init_as_frmr_rsp(struct sk_buff *skb, struct llc_pdu_sn *prev_pdu,
433 u8 f_bit, u8 vs, u8 vr, u8 vzyxw);
434void llc_pdu_init_as_rr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
435void llc_pdu_init_as_rej_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
436void llc_pdu_init_as_rnr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
437void llc_pdu_init_as_ua_rsp(struct sk_buff *skb, u8 f_bit);
438#endif /* LLC_PDU_H */