1#ifndef LLC_PDU_H 2#define LLC_PDU_H 3/* 4 * Copyright (c) 1997 by Procom Technology,Inc. 5 * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br> 6 * 7 * This program can be redistributed or modified under the terms of the 8 * GNU General Public License as published by the Free Software Foundation. 9 * This program is distributed without any warranty or implied warranty 10 * of merchantability or fitness for a particular purpose. 11 * 12 * See the GNU General Public License for more details. 13 */ 14 15#include <linux/if_ether.h> 16#include <linux/if_tr.h> 17 18/* Lengths of frame formats */ 19#define LLC_PDU_LEN_I 4 /* header and 2 control bytes */ 20#define LLC_PDU_LEN_S 4 21#define LLC_PDU_LEN_U 3 /* header and 1 control byte */ 22/* Known SAP addresses */ 23#define LLC_GLOBAL_SAP 0xFF 24#define LLC_NULL_SAP 0x00 /* not network-layer visible */ 25#define LLC_MGMT_INDIV 0x02 /* station LLC mgmt indiv addr */ 26#define LLC_MGMT_GRP 0x03 /* station LLC mgmt group addr */ 27#define LLC_RDE_SAP 0xA6 /* route ... */ 28 29/* SAP field bit masks */ 30#define LLC_ISO_RESERVED_SAP 0x02 31#define LLC_SAP_GROUP_DSAP 0x01 32#define LLC_SAP_RESP_SSAP 0x01 33 34/* Group/individual DSAP indicator is DSAP field */ 35#define LLC_PDU_GROUP_DSAP_MASK 0x01 36#define LLC_PDU_IS_GROUP_DSAP(pdu) \ 37 ((pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1) 38#define LLC_PDU_IS_INDIV_DSAP(pdu) \ 39 (!(pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1) 40 41/* Command/response PDU indicator in SSAP field */ 42#define LLC_PDU_CMD_RSP_MASK 0x01 43#define LLC_PDU_CMD 0 44#define LLC_PDU_RSP 1 45#define LLC_PDU_IS_CMD(pdu) ((pdu->ssap & LLC_PDU_RSP) ? 0 : 1) 46#define LLC_PDU_IS_RSP(pdu) ((pdu->ssap & LLC_PDU_RSP) ? 1 : 0) 47 48/* Get PDU type from 2 lowest-order bits of control field first byte */ 49#define LLC_PDU_TYPE_I_MASK 0x01 /* 16-bit control field */ 50#define LLC_PDU_TYPE_S_MASK 0x03 51#define LLC_PDU_TYPE_U_MASK 0x03 /* 8-bit control field */ 52#define LLC_PDU_TYPE_MASK 0x03 53 54#define LLC_PDU_TYPE_I 0 /* first bit */ 55#define LLC_PDU_TYPE_S 1 /* first two bits */ 56#define LLC_PDU_TYPE_U 3 /* first two bits */ 57 58#define LLC_PDU_TYPE_IS_I(pdu) \ 59 ((!(pdu->ctrl_1 & LLC_PDU_TYPE_I_MASK)) ? 1 : 0) 60 61#define LLC_PDU_TYPE_IS_U(pdu) \ 62 (((pdu->ctrl_1 & LLC_PDU_TYPE_U_MASK) == LLC_PDU_TYPE_U) ? 1 : 0) 63 64#define LLC_PDU_TYPE_IS_S(pdu) \ 65 (((pdu->ctrl_1 & LLC_PDU_TYPE_S_MASK) == LLC_PDU_TYPE_S) ? 1 : 0) 66 67/* U-format PDU control field masks */ 68#define LLC_U_PF_BIT_MASK 0x10 /* P/F bit mask */ 69#define LLC_U_PF_IS_1(pdu) ((pdu->ctrl_1 & LLC_U_PF_BIT_MASK) ? 1 : 0) 70#define LLC_U_PF_IS_0(pdu) ((!(pdu->ctrl_1 & LLC_U_PF_BIT_MASK)) ? 1 : 0) 71 72#define LLC_U_PDU_CMD_MASK 0xEC /* cmd/rsp mask */ 73#define LLC_U_PDU_CMD(pdu) (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK) 74#define LLC_U_PDU_RSP(pdu) (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK) 75 76#define LLC_1_PDU_CMD_UI 0x00 /* Type 1 cmds/rsps */ 77#define LLC_1_PDU_CMD_XID 0xAC 78#define LLC_1_PDU_CMD_TEST 0xE0 79 80#define LLC_2_PDU_CMD_SABME 0x6C /* Type 2 cmds/rsps */ 81#define LLC_2_PDU_CMD_DISC 0x40 82#define LLC_2_PDU_RSP_UA 0x60 83#define LLC_2_PDU_RSP_DM 0x0C 84#define LLC_2_PDU_RSP_FRMR 0x84 85 86/* Type 1 operations */ 87 88/* XID information field bit masks */ 89 90/* LLC format identifier (byte 1) */ 91#define LLC_XID_FMT_ID 0x81 /* first byte must be this */ 92 93/* LLC types/classes identifier (byte 2) */ 94#define LLC_XID_CLASS_ZEROS_MASK 0xE0 /* these must be zeros */ 95#define LLC_XID_CLASS_MASK 0x1F /* AND with byte to get below */ 96 97#define LLC_XID_NULL_CLASS_1 0x01 /* if NULL LSAP...use these */ 98#define LLC_XID_NULL_CLASS_2 0x03 99#define LLC_XID_NULL_CLASS_3 0x05 100#define LLC_XID_NULL_CLASS_4 0x07 101 102#define LLC_XID_NNULL_TYPE_1 0x01 /* if non-NULL LSAP...use these */ 103#define LLC_XID_NNULL_TYPE_2 0x02 104#define LLC_XID_NNULL_TYPE_3 0x04 105#define LLC_XID_NNULL_TYPE_1_2 0x03 106#define LLC_XID_NNULL_TYPE_1_3 0x05 107#define LLC_XID_NNULL_TYPE_2_3 0x06 108#define LLC_XID_NNULL_ALL 0x07 109 110/* Sender Receive Window (byte 3) */ 111#define LLC_XID_RW_MASK 0xFE /* AND with value to get below */ 112 113#define LLC_XID_MIN_RW 0x02 /* lowest-order bit always zero */ 114 115/* Type 2 operations */ 116 117#define LLC_2_SEQ_NBR_MODULO ((u8) 128) 118 119/* I-PDU masks ('ctrl' is I-PDU control word) */ 120#define LLC_I_GET_NS(pdu) (u8)((pdu->ctrl_1 & 0xFE) >> 1) 121#define LLC_I_GET_NR(pdu) (u8)((pdu->ctrl_2 & 0xFE) >> 1) 122 123#define LLC_I_PF_BIT_MASK 0x01 124 125#define LLC_I_PF_IS_0(pdu) ((!(pdu->ctrl_2 & LLC_I_PF_BIT_MASK)) ? 1 : 0) 126#define LLC_I_PF_IS_1(pdu) ((pdu->ctrl_2 & LLC_I_PF_BIT_MASK) ? 1 : 0) 127 128/* S-PDU supervisory commands and responses */ 129 130#define LLC_S_PDU_CMD_MASK 0x0C 131#define LLC_S_PDU_CMD(pdu) (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK) 132#define LLC_S_PDU_RSP(pdu) (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK) 133 134#define LLC_2_PDU_CMD_RR 0x00 /* rx ready cmd */ 135#define LLC_2_PDU_RSP_RR 0x00 /* rx ready rsp */ 136#define LLC_2_PDU_CMD_REJ 0x08 /* reject PDU cmd */ 137#define LLC_2_PDU_RSP_REJ 0x08 /* reject PDU rsp */ 138#define LLC_2_PDU_CMD_RNR 0x04 /* rx not ready cmd */ 139#define LLC_2_PDU_RSP_RNR 0x04 /* rx not ready rsp */ 140 141#define LLC_S_PF_BIT_MASK 0x01 142#define LLC_S_PF_IS_0(pdu) ((!(pdu->ctrl_2 & LLC_S_PF_BIT_MASK)) ? 1 : 0) 143#define LLC_S_PF_IS_1(pdu) ((pdu->ctrl_2 & LLC_S_PF_BIT_MASK) ? 1 : 0) 144 145#define PDU_SUPV_GET_Nr(pdu) ((pdu->ctrl_2 & 0xFE) >> 1) 146#define PDU_GET_NEXT_Vr(sn) (++sn & ~LLC_2_SEQ_NBR_MODULO) 147 148/* FRMR information field macros */ 149 150#define FRMR_INFO_LENGTH 5 /* 5 bytes of information */ 151 152/* 153 * info is pointer to FRMR info field structure; 'rej_ctrl' is byte pointer 154 * (if U-PDU) or word pointer to rejected PDU control field 155 */ 156#define FRMR_INFO_SET_REJ_CNTRL(info,rej_ctrl) \ 157 info->rej_pdu_ctrl = ((*((u8 *) rej_ctrl) & \ 158 LLC_PDU_TYPE_U) != LLC_PDU_TYPE_U ? \ 159 (u16)*((u16 *) rej_ctrl) : \ 160 (((u16) *((u8 *) rej_ctrl)) & 0x00FF)) 161 162/* 163 * Info is pointer to FRMR info field structure; 'vs' is a byte containing 164 * send state variable value in low-order 7 bits (insure the lowest-order 165 * bit remains zero (0)) 166 */ 167#define FRMR_INFO_SET_Vs(info,vs) (info->curr_ssv = (((u8) vs) << 1)) 168#define FRMR_INFO_SET_Vr(info,vr) (info->curr_rsv = (((u8) vr) << 1)) 169 170/* 171 * Info is pointer to FRMR info field structure; 'cr' is a byte containing 172 * the C/R bit value in the low-order bit 173 */ 174#define FRMR_INFO_SET_C_R_BIT(info, cr) (info->curr_rsv |= (((u8) cr) & 0x01)) 175 176/* 177 * In the remaining five macros, 'info' is pointer to FRMR info field 178 * structure; 'ind' is a byte containing the bit value to set in the 179 * lowest-order bit) 180 */ 181#define FRMR_INFO_SET_INVALID_PDU_CTRL_IND(info, ind) \ 182 (info->ind_bits = ((info->ind_bits & 0xFE) | (((u8) ind) & 0x01))) 183 184#define FRMR_INFO_SET_INVALID_PDU_INFO_IND(info, ind) \ 185 (info->ind_bits = ( (info->ind_bits & 0xFD) | (((u8) ind) & 0x02))) 186 187#define FRMR_INFO_SET_PDU_INFO_2LONG_IND(info, ind) \ 188 (info->ind_bits = ( (info->ind_bits & 0xFB) | (((u8) ind) & 0x04))) 189 190#define FRMR_INFO_SET_PDU_INVALID_Nr_IND(info, ind) \ 191 (info->ind_bits = ( (info->ind_bits & 0xF7) | (((u8) ind) & 0x08))) 192 193#define FRMR_INFO_SET_PDU_INVALID_Ns_IND(info, ind) \ 194 (info->ind_bits = ( (info->ind_bits & 0xEF) | (((u8) ind) & 0x10))) 195 196/* Sequence-numbered PDU format (4 bytes in length) */ 197struct llc_pdu_sn { 198 u8 dsap; 199 u8 ssap; 200 u8 ctrl_1; 201 u8 ctrl_2; 202}; 203 204static inline struct llc_pdu_sn *llc_pdu_sn_hdr(struct sk_buff *skb) 205{ 206 return (struct llc_pdu_sn *)skb_network_header(skb); 207} 208 209/* Un-numbered PDU format (3 bytes in length) */ 210struct llc_pdu_un { 211 u8 dsap; 212 u8 ssap; 213 u8 ctrl_1; 214}; 215 216static inline struct llc_pdu_un *llc_pdu_un_hdr(struct sk_buff *skb) 217{ 218 return (struct llc_pdu_un *)skb_network_header(skb); 219} 220 221/** 222 * llc_pdu_header_init - initializes pdu header 223 * @skb: input skb that header must be set into it. 224 * @type: type of PDU (U, I or S). 225 * @ssap: source sap. 226 * @dsap: destination sap. 227 * @cr: command/response bit (0 or 1). 228 * 229 * This function sets DSAP, SSAP and command/Response bit in LLC header. 230 */ 231static inline void llc_pdu_header_init(struct sk_buff *skb, u8 type, 232 u8 ssap, u8 dsap, u8 cr) 233{ 234 const int hlen = type == LLC_PDU_TYPE_U ? 3 : 4; 235 struct llc_pdu_un *pdu; 236 237 skb_push(skb, hlen); 238 skb_reset_network_header(skb); 239 pdu = llc_pdu_un_hdr(skb); 240 pdu->dsap = dsap; 241 pdu->ssap = ssap; 242 pdu->ssap |= cr; 243} 244 245/** 246 * llc_pdu_decode_sa - extracs source address (MAC) of input frame 247 * @skb: input skb that source address must be extracted from it. 248 * @sa: pointer to source address (6 byte array). 249 * 250 * This function extracts source address(MAC) of input frame. 251 */ 252static inline void llc_pdu_decode_sa(struct sk_buff *skb, u8 *sa) 253{ 254 if (skb->protocol == htons(ETH_P_802_2)) 255 memcpy(sa, eth_hdr(skb)->h_source, ETH_ALEN); 256 else if (skb->protocol == htons(ETH_P_TR_802_2)) { 257 memcpy(sa, tr_hdr(skb)->saddr, ETH_ALEN); 258 *sa &= 0x7F; 259 } 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 * @sa: 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 if (skb->protocol == htons(ETH_P_802_2)) 272 memcpy(da, eth_hdr(skb)->h_dest, ETH_ALEN); 273 else if (skb->protocol == htons(ETH_P_TR_802_2)) 274 memcpy(da, tr_hdr(skb)->daddr, ETH_ALEN); 275} 276 277/** 278 * llc_pdu_decode_ssap - extracts source SAP of input frame 279 * @skb: input skb that source SAP must be extracted from it. 280 * @ssap: source SAP (output argument). 281 * 282 * This function extracts source SAP of input frame. Right bit of SSAP is 283 * command/response bit. 284 */ 285static inline void llc_pdu_decode_ssap(struct sk_buff *skb, u8 *ssap) 286{ 287 *ssap = llc_pdu_un_hdr(skb)->ssap & 0xFE; 288} 289 290/** 291 * llc_pdu_decode_dsap - extracts dest SAP of input frame 292 * @skb: input skb that destination SAP must be extracted from it. 293 * @dsap: destination SAP (output argument). 294 * 295 * This function extracts destination SAP of input frame. right bit of 296 * DSAP designates individual/group SAP. 297 */ 298static inline void llc_pdu_decode_dsap(struct sk_buff *skb, u8 *dsap) 299{ 300 *dsap = llc_pdu_un_hdr(skb)->dsap & 0xFE; 301} 302 303/** 304 * llc_pdu_init_as_ui_cmd - sets LLC header as UI PDU 305 * @skb: input skb that header must be set into it. 306 * 307 * This function sets third byte of LLC header as a UI PDU. 308 */ 309static inline void llc_pdu_init_as_ui_cmd(struct sk_buff *skb) 310{ 311 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); 312 313 pdu->ctrl_1 = LLC_PDU_TYPE_U; 314 pdu->ctrl_1 |= LLC_1_PDU_CMD_UI; 315} 316 317/** 318 * llc_pdu_init_as_test_cmd - sets PDU as TEST 319 * @skb - Address of the skb to build 320 * 321 * Sets a PDU as TEST 322 */ 323static inline void llc_pdu_init_as_test_cmd(struct sk_buff *skb) 324{ 325 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); 326 327 pdu->ctrl_1 = LLC_PDU_TYPE_U; 328 pdu->ctrl_1 |= LLC_1_PDU_CMD_TEST; 329 pdu->ctrl_1 |= LLC_U_PF_BIT_MASK; 330} 331 332/** 333 * llc_pdu_init_as_test_rsp - build TEST response PDU 334 * @skb: Address of the skb to build 335 * @ev_skb: The received TEST command PDU frame 336 * 337 * Builds a pdu frame as a TEST response. 338 */ 339static inline void llc_pdu_init_as_test_rsp(struct sk_buff *skb, 340 struct sk_buff *ev_skb) 341{ 342 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); 343 344 pdu->ctrl_1 = LLC_PDU_TYPE_U; 345 pdu->ctrl_1 |= LLC_1_PDU_CMD_TEST; 346 pdu->ctrl_1 |= LLC_U_PF_BIT_MASK; 347 if (ev_skb->protocol == htons(ETH_P_802_2)) { 348 struct llc_pdu_un *ev_pdu = llc_pdu_un_hdr(ev_skb); 349 int dsize; 350 351 dsize = ntohs(eth_hdr(ev_skb)->h_proto) - 3; 352 memcpy(((u8 *)pdu) + 3, ((u8 *)ev_pdu) + 3, dsize); 353 skb_put(skb, dsize); 354 } 355} 356 357/* LLC Type 1 XID command/response information fields format */ 358struct llc_xid_info { 359 u8 fmt_id; /* always 0x81 for LLC */ 360 u8 type; /* different if NULL/non-NULL LSAP */ 361 u8 rw; /* sender receive window */ 362}; 363 364/** 365 * llc_pdu_init_as_xid_cmd - sets bytes 3, 4 & 5 of LLC header as XID 366 * @skb: input skb that header must be set into it. 367 * 368 * This function sets third,fourth,fifth and sixth bytes of LLC header as 369 * a XID PDU. 370 */ 371static inline void llc_pdu_init_as_xid_cmd(struct sk_buff *skb, 372 u8 svcs_supported, u8 rx_window) 373{ 374 struct llc_xid_info *xid_info; 375 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); 376 377 pdu->ctrl_1 = LLC_PDU_TYPE_U; 378 pdu->ctrl_1 |= LLC_1_PDU_CMD_XID; 379 pdu->ctrl_1 |= LLC_U_PF_BIT_MASK; 380 xid_info = (struct llc_xid_info *)(((u8 *)&pdu->ctrl_1) + 1); 381 xid_info->fmt_id = LLC_XID_FMT_ID; /* 0x81 */ 382 xid_info->type = svcs_supported; 383 xid_info->rw = rx_window << 1; /* size of receive window */ 384 skb_put(skb, 3); 385} 386 387/** 388 * llc_pdu_init_as_xid_rsp - builds XID response PDU 389 * @skb: Address of the skb to build 390 * @svcs_supported: The class of the LLC (I or II) 391 * @rx_window: The size of the receive window of the LLC 392 * 393 * Builds a pdu frame as an XID response. 394 */ 395static inline void llc_pdu_init_as_xid_rsp(struct sk_buff *skb, 396 u8 svcs_supported, u8 rx_window) 397{ 398 struct llc_xid_info *xid_info; 399 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); 400 401 pdu->ctrl_1 = LLC_PDU_TYPE_U; 402 pdu->ctrl_1 |= LLC_1_PDU_CMD_XID; 403 pdu->ctrl_1 |= LLC_U_PF_BIT_MASK; 404 405 xid_info = (struct llc_xid_info *)(((u8 *)&pdu->ctrl_1) + 1); 406 xid_info->fmt_id = LLC_XID_FMT_ID; 407 xid_info->type = svcs_supported; 408 xid_info->rw = rx_window << 1; 409 skb_put(skb, 3); 410} 411 412/* LLC Type 2 FRMR response information field format */ 413struct llc_frmr_info { 414 u16 rej_pdu_ctrl; /* bits 1-8 if U-PDU */ 415 u8 curr_ssv; /* current send state variable val */ 416 u8 curr_rsv; /* current receive state variable */ 417 u8 ind_bits; /* indicator bits set with macro */ 418}; 419 420extern void llc_pdu_set_cmd_rsp(struct sk_buff *skb, u8 type); 421extern void llc_pdu_set_pf_bit(struct sk_buff *skb, u8 bit_value); 422extern void llc_pdu_decode_pf_bit(struct sk_buff *skb, u8 *pf_bit); 423extern void llc_pdu_init_as_disc_cmd(struct sk_buff *skb, u8 p_bit); 424extern void llc_pdu_init_as_i_cmd(struct sk_buff *skb, u8 p_bit, u8 ns, u8 nr); 425extern void llc_pdu_init_as_rej_cmd(struct sk_buff *skb, u8 p_bit, u8 nr); 426extern void llc_pdu_init_as_rnr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr); 427extern void llc_pdu_init_as_rr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr); 428extern void llc_pdu_init_as_sabme_cmd(struct sk_buff *skb, u8 p_bit); 429extern void llc_pdu_init_as_dm_rsp(struct sk_buff *skb, u8 f_bit); 430extern void llc_pdu_init_as_frmr_rsp(struct sk_buff *skb, 431 struct llc_pdu_sn *prev_pdu, 432 u8 f_bit, u8 vs, u8 vr, u8 vzyxw); 433extern void llc_pdu_init_as_rr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr); 434extern void llc_pdu_init_as_rej_rsp(struct sk_buff *skb, u8 f_bit, u8 nr); 435extern void llc_pdu_init_as_rnr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr); 436extern void llc_pdu_init_as_ua_rsp(struct sk_buff *skb, u8 f_bit); 437#endif /* LLC_PDU_H */ 438