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 17/* Lengths of frame formats */ 18#define LLC_PDU_LEN_I 4 /* header and 2 control bytes */ 19#define LLC_PDU_LEN_S 4 20#define LLC_PDU_LEN_U 3 /* header and 1 control byte */ 21/* header and 1 control byte and XID info */ 22#define LLC_PDU_LEN_U_XID (LLC_PDU_LEN_U + sizeof(struct llc_xid_info)) 23/* Known SAP addresses */ 24#define LLC_GLOBAL_SAP 0xFF 25#define LLC_NULL_SAP 0x00 /* not network-layer visible */ 26#define LLC_MGMT_INDIV 0x02 /* station LLC mgmt indiv addr */ 27#define LLC_MGMT_GRP 0x03 /* station LLC mgmt group addr */ 28#define LLC_RDE_SAP 0xA6 /* route ... */ 29 30/* SAP field bit masks */ 31#define LLC_ISO_RESERVED_SAP 0x02 32#define LLC_SAP_GROUP_DSAP 0x01 33#define LLC_SAP_RESP_SSAP 0x01 34 35/* Group/individual DSAP indicator is DSAP field */ 36#define LLC_PDU_GROUP_DSAP_MASK 0x01 37#define LLC_PDU_IS_GROUP_DSAP(pdu) \ 38 ((pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1) 39#define LLC_PDU_IS_INDIV_DSAP(pdu) \ 40 (!(pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1) 41 42/* Command/response PDU indicator in SSAP field */ 43#define LLC_PDU_CMD_RSP_MASK 0x01 44#define LLC_PDU_CMD 0 45#define LLC_PDU_RSP 1 46#define LLC_PDU_IS_CMD(pdu) ((pdu->ssap & LLC_PDU_RSP) ? 0 : 1) 47#define LLC_PDU_IS_RSP(pdu) ((pdu->ssap & LLC_PDU_RSP) ? 1 : 0) 48 49/* Get PDU type from 2 lowest-order bits of control field first byte */ 50#define LLC_PDU_TYPE_I_MASK 0x01 /* 16-bit control field */ 51#define LLC_PDU_TYPE_S_MASK 0x03 52#define LLC_PDU_TYPE_U_MASK 0x03 /* 8-bit control field */ 53#define LLC_PDU_TYPE_MASK 0x03 54 55#define LLC_PDU_TYPE_I 0 /* first bit */ 56#define LLC_PDU_TYPE_S 1 /* first two bits */ 57#define LLC_PDU_TYPE_U 3 /* first two bits */ 58#define LLC_PDU_TYPE_U_XID 4 /* private type for detecting XID commands */ 59 60#define LLC_PDU_TYPE_IS_I(pdu) \ 61 ((!(pdu->ctrl_1 & LLC_PDU_TYPE_I_MASK)) ? 1 : 0) 62 63#define LLC_PDU_TYPE_IS_U(pdu) \ 64 (((pdu->ctrl_1 & LLC_PDU_TYPE_U_MASK) == LLC_PDU_TYPE_U) ? 1 : 0) 65 66#define LLC_PDU_TYPE_IS_S(pdu) \ 67 (((pdu->ctrl_1 & LLC_PDU_TYPE_S_MASK) == LLC_PDU_TYPE_S) ? 1 : 0) 68 69/* U-format PDU control field masks */ 70#define LLC_U_PF_BIT_MASK 0x10 /* P/F bit mask */ 71#define LLC_U_PF_IS_1(pdu) ((pdu->ctrl_1 & LLC_U_PF_BIT_MASK) ? 1 : 0) 72#define LLC_U_PF_IS_0(pdu) ((!(pdu->ctrl_1 & LLC_U_PF_BIT_MASK)) ? 1 : 0) 73 74#define LLC_U_PDU_CMD_MASK 0xEC /* cmd/rsp mask */ 75#define LLC_U_PDU_CMD(pdu) (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK) 76#define LLC_U_PDU_RSP(pdu) (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK) 77 78#define LLC_1_PDU_CMD_UI 0x00 /* Type 1 cmds/rsps */ 79#define LLC_1_PDU_CMD_XID 0xAC 80#define LLC_1_PDU_CMD_TEST 0xE0 81 82#define LLC_2_PDU_CMD_SABME 0x6C /* Type 2 cmds/rsps */ 83#define LLC_2_PDU_CMD_DISC 0x40 84#define LLC_2_PDU_RSP_UA 0x60 85#define LLC_2_PDU_RSP_DM 0x0C 86#define LLC_2_PDU_RSP_FRMR 0x84 87 88/* Type 1 operations */ 89 90/* XID information field bit masks */ 91 92/* LLC format identifier (byte 1) */ 93#define LLC_XID_FMT_ID 0x81 /* first byte must be this */ 94 95/* LLC types/classes identifier (byte 2) */ 96#define LLC_XID_CLASS_ZEROS_MASK 0xE0 /* these must be zeros */ 97#define LLC_XID_CLASS_MASK 0x1F /* AND with byte to get below */ 98 99#define LLC_XID_NULL_CLASS_1 0x01 /* if NULL LSAP...use these */ 100#define LLC_XID_NULL_CLASS_2 0x03 101#define LLC_XID_NULL_CLASS_3 0x05 102#define LLC_XID_NULL_CLASS_4 0x07 103 104#define LLC_XID_NNULL_TYPE_1 0x01 /* if non-NULL LSAP...use these */ 105#define LLC_XID_NNULL_TYPE_2 0x02 106#define LLC_XID_NNULL_TYPE_3 0x04 107#define LLC_XID_NNULL_TYPE_1_2 0x03 108#define LLC_XID_NNULL_TYPE_1_3 0x05 109#define LLC_XID_NNULL_TYPE_2_3 0x06 110#define LLC_XID_NNULL_ALL 0x07 111 112/* Sender Receive Window (byte 3) */ 113#define LLC_XID_RW_MASK 0xFE /* AND with value to get below */ 114 115#define LLC_XID_MIN_RW 0x02 /* lowest-order bit always zero */ 116 117/* Type 2 operations */ 118 119#define LLC_2_SEQ_NBR_MODULO ((u8) 128) 120 121/* I-PDU masks ('ctrl' is I-PDU control word) */ 122#define LLC_I_GET_NS(pdu) (u8)((pdu->ctrl_1 & 0xFE) >> 1) 123#define LLC_I_GET_NR(pdu) (u8)((pdu->ctrl_2 & 0xFE) >> 1) 124 125#define LLC_I_PF_BIT_MASK 0x01 126 127#define LLC_I_PF_IS_0(pdu) ((!(pdu->ctrl_2 & LLC_I_PF_BIT_MASK)) ? 1 : 0) 128#define LLC_I_PF_IS_1(pdu) ((pdu->ctrl_2 & LLC_I_PF_BIT_MASK) ? 1 : 0) 129 130/* S-PDU supervisory commands and responses */ 131 132#define LLC_S_PDU_CMD_MASK 0x0C 133#define LLC_S_PDU_CMD(pdu) (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK) 134#define LLC_S_PDU_RSP(pdu) (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK) 135 136#define LLC_2_PDU_CMD_RR 0x00 /* rx ready cmd */ 137#define LLC_2_PDU_RSP_RR 0x00 /* rx ready rsp */ 138#define LLC_2_PDU_CMD_REJ 0x08 /* reject PDU cmd */ 139#define LLC_2_PDU_RSP_REJ 0x08 /* reject PDU rsp */ 140#define LLC_2_PDU_CMD_RNR 0x04 /* rx not ready cmd */ 141#define LLC_2_PDU_RSP_RNR 0x04 /* rx not ready rsp */ 142 143#define LLC_S_PF_BIT_MASK 0x01 144#define LLC_S_PF_IS_0(pdu) ((!(pdu->ctrl_2 & LLC_S_PF_BIT_MASK)) ? 1 : 0) 145#define LLC_S_PF_IS_1(pdu) ((pdu->ctrl_2 & LLC_S_PF_BIT_MASK) ? 1 : 0) 146 147#define PDU_SUPV_GET_Nr(pdu) ((pdu->ctrl_2 & 0xFE) >> 1) 148#define PDU_GET_NEXT_Vr(sn) (((sn) + 1) & ~LLC_2_SEQ_NBR_MODULO) 149 150/* FRMR information field macros */ 151 152#define FRMR_INFO_LENGTH 5 /* 5 bytes of information */ 153 154/* 155 * info is pointer to FRMR info field structure; 'rej_ctrl' is byte pointer 156 * (if U-PDU) or word pointer to rejected PDU control field 157 */ 158#define FRMR_INFO_SET_REJ_CNTRL(info,rej_ctrl) \ 159 info->rej_pdu_ctrl = ((*((u8 *) rej_ctrl) & \ 160 LLC_PDU_TYPE_U) != LLC_PDU_TYPE_U ? \ 161 (u16)*((u16 *) rej_ctrl) : \ 162 (((u16) *((u8 *) rej_ctrl)) & 0x00FF)) 163 164/* 165 * Info is pointer to FRMR info field structure; 'vs' is a byte containing 166 * send state variable value in low-order 7 bits (insure the lowest-order 167 * bit remains zero (0)) 168 */ 169#define FRMR_INFO_SET_Vs(info,vs) (info->curr_ssv = (((u8) vs) << 1)) 170#define FRMR_INFO_SET_Vr(info,vr) (info->curr_rsv = (((u8) vr) << 1)) 171 172/* 173 * Info is pointer to FRMR info field structure; 'cr' is a byte containing 174 * the C/R bit value in the low-order bit 175 */ 176#define FRMR_INFO_SET_C_R_BIT(info, cr) (info->curr_rsv |= (((u8) cr) & 0x01)) 177 178/* 179 * In the remaining five macros, 'info' is pointer to FRMR info field 180 * structure; 'ind' is a byte containing the bit value to set in the 181 * lowest-order bit) 182 */ 183#define FRMR_INFO_SET_INVALID_PDU_CTRL_IND(info, ind) \ 184 (info->ind_bits = ((info->ind_bits & 0xFE) | (((u8) ind) & 0x01))) 185 186#define FRMR_INFO_SET_INVALID_PDU_INFO_IND(info, ind) \ 187 (info->ind_bits = ( (info->ind_bits & 0xFD) | (((u8) ind) & 0x02))) 188 189#define FRMR_INFO_SET_PDU_INFO_2LONG_IND(info, ind) \ 190 (info->ind_bits = ( (info->ind_bits & 0xFB) | (((u8) ind) & 0x04))) 191 192#define FRMR_INFO_SET_PDU_INVALID_Nr_IND(info, ind) \ 193 (info->ind_bits = ( (info->ind_bits & 0xF7) | (((u8) ind) & 0x08))) 194 195#define FRMR_INFO_SET_PDU_INVALID_Ns_IND(info, ind) \ 196 (info->ind_bits = ( (info->ind_bits & 0xEF) | (((u8) ind) & 0x10))) 197 198/* Sequence-numbered PDU format (4 bytes in length) */ 199struct llc_pdu_sn { 200 u8 dsap; 201 u8 ssap; 202 u8 ctrl_1; 203 u8 ctrl_2; 204} __packed; 205 206static inline struct llc_pdu_sn *llc_pdu_sn_hdr(struct sk_buff *skb) 207{ 208 return (struct llc_pdu_sn *)skb_network_header(skb); 209} 210 211/* Un-numbered PDU format (3 bytes in length) */ 212struct llc_pdu_un { 213 u8 dsap; 214 u8 ssap; 215 u8 ctrl_1; 216} __packed; 217 218static inline struct llc_pdu_un *llc_pdu_un_hdr(struct sk_buff *skb) 219{ 220 return (struct llc_pdu_un *)skb_network_header(skb); 221} 222 223/** 224 * llc_pdu_header_init - initializes pdu header 225 * @skb: input skb that header must be set into it. 226 * @type: type of PDU (U, I or S). 227 * @ssap: source sap. 228 * @dsap: destination sap. 229 * @cr: command/response bit (0 or 1). 230 * 231 * This function sets DSAP, SSAP and command/Response bit in LLC header. 232 */ 233static inline void llc_pdu_header_init(struct sk_buff *skb, u8 type, 234 u8 ssap, u8 dsap, u8 cr) 235{ 236 int hlen = 4; /* default value for I and S types */ 237 struct llc_pdu_un *pdu; 238 239 switch (type) { 240 case LLC_PDU_TYPE_U: 241 hlen = 3; 242 break; 243 case LLC_PDU_TYPE_U_XID: 244 hlen = 6; 245 break; 246 } 247 248 skb_push(skb, hlen); 249 skb_reset_network_header(skb); 250 pdu = llc_pdu_un_hdr(skb); 251 pdu->dsap = dsap; 252 pdu->ssap = ssap; 253 pdu->ssap |= cr; 254} 255 256/** 257 * llc_pdu_decode_sa - extracs source address (MAC) of input frame 258 * @skb: input skb that source address must be extracted from it. 259 * @sa: pointer to source address (6 byte array). 260 * 261 * This function extracts source address(MAC) of input frame. 262 */ 263static inline void llc_pdu_decode_sa(struct sk_buff *skb, u8 *sa) 264{ 265 memcpy(sa, eth_hdr(skb)->h_source, ETH_ALEN); 266} 267 268/** 269 * llc_pdu_decode_da - extracts dest address of input frame 270 * @skb: input skb that destination address must be extracted from it 271 * @da: pointer to destination address (6 byte array). 272 * 273 * This function extracts destination address(MAC) of input frame. 274 */ 275static inline void llc_pdu_decode_da(struct sk_buff *skb, u8 *da) 276{ 277 memcpy(da, eth_hdr(skb)->h_dest, ETH_ALEN); 278} 279 280/** 281 * llc_pdu_decode_ssap - extracts source SAP of input frame 282 * @skb: input skb that source SAP must be extracted from it. 283 * @ssap: source SAP (output argument). 284 * 285 * This function extracts source SAP of input frame. Right bit of SSAP is 286 * command/response bit. 287 */ 288static inline void llc_pdu_decode_ssap(struct sk_buff *skb, u8 *ssap) 289{ 290 *ssap = llc_pdu_un_hdr(skb)->ssap & 0xFE; 291} 292 293/** 294 * llc_pdu_decode_dsap - extracts dest SAP of input frame 295 * @skb: input skb that destination SAP must be extracted from it. 296 * @dsap: destination SAP (output argument). 297 * 298 * This function extracts destination SAP of input frame. right bit of 299 * DSAP designates individual/group SAP. 300 */ 301static inline void llc_pdu_decode_dsap(struct sk_buff *skb, u8 *dsap) 302{ 303 *dsap = llc_pdu_un_hdr(skb)->dsap & 0xFE; 304} 305 306/** 307 * llc_pdu_init_as_ui_cmd - sets LLC header as UI PDU 308 * @skb: input skb that header must be set into it. 309 * 310 * This function sets third byte of LLC header as a UI PDU. 311 */ 312static inline void llc_pdu_init_as_ui_cmd(struct sk_buff *skb) 313{ 314 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); 315 316 pdu->ctrl_1 = LLC_PDU_TYPE_U; 317 pdu->ctrl_1 |= LLC_1_PDU_CMD_UI; 318} 319 320/** 321 * llc_pdu_init_as_test_cmd - sets PDU as TEST 322 * @skb: Address of the skb to build 323 * 324 * Sets a PDU as TEST 325 */ 326static inline void llc_pdu_init_as_test_cmd(struct sk_buff *skb) 327{ 328 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); 329 330 pdu->ctrl_1 = LLC_PDU_TYPE_U; 331 pdu->ctrl_1 |= LLC_1_PDU_CMD_TEST; 332 pdu->ctrl_1 |= LLC_U_PF_BIT_MASK; 333} 334 335/** 336 * llc_pdu_init_as_test_rsp - build TEST response PDU 337 * @skb: Address of the skb to build 338 * @ev_skb: The received TEST command PDU frame 339 * 340 * Builds a pdu frame as a TEST response. 341 */ 342static inline void llc_pdu_init_as_test_rsp(struct sk_buff *skb, 343 struct sk_buff *ev_skb) 344{ 345 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); 346 347 pdu->ctrl_1 = LLC_PDU_TYPE_U; 348 pdu->ctrl_1 |= LLC_1_PDU_CMD_TEST; 349 pdu->ctrl_1 |= LLC_U_PF_BIT_MASK; 350 if (ev_skb->protocol == htons(ETH_P_802_2)) { 351 struct llc_pdu_un *ev_pdu = llc_pdu_un_hdr(ev_skb); 352 int dsize; 353 354 dsize = ntohs(eth_hdr(ev_skb)->h_proto) - 3; 355 memcpy(((u8 *)pdu) + 3, ((u8 *)ev_pdu) + 3, dsize); 356 skb_put(skb, dsize); 357 } 358} 359 360/* LLC Type 1 XID command/response information fields format */ 361struct llc_xid_info { 362 u8 fmt_id; /* always 0x81 for LLC */ 363 u8 type; /* different if NULL/non-NULL LSAP */ 364 u8 rw; /* sender receive window */ 365} __packed; 366 367/** 368 * llc_pdu_init_as_xid_cmd - sets bytes 3, 4 & 5 of LLC header as XID 369 * @skb: input skb that header must be set into it. 370 * @svcs_supported: The class of the LLC (I or II) 371 * @rx_window: The size of the receive window of the LLC 372 * 373 * This function sets third,fourth,fifth and sixth bytes of LLC header as 374 * a XID PDU. 375 */ 376static inline void llc_pdu_init_as_xid_cmd(struct sk_buff *skb, 377 u8 svcs_supported, u8 rx_window) 378{ 379 struct llc_xid_info *xid_info; 380 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); 381 382 pdu->ctrl_1 = LLC_PDU_TYPE_U; 383 pdu->ctrl_1 |= LLC_1_PDU_CMD_XID; 384 pdu->ctrl_1 |= LLC_U_PF_BIT_MASK; 385 xid_info = (struct llc_xid_info *)(((u8 *)&pdu->ctrl_1) + 1); 386 xid_info->fmt_id = LLC_XID_FMT_ID; /* 0x81 */ 387 xid_info->type = svcs_supported; 388 xid_info->rw = rx_window << 1; /* size of receive window */ 389 390 /* no need to push/put since llc_pdu_header_init() has already 391 * pushed 3 + 3 bytes 392 */ 393} 394 395/** 396 * llc_pdu_init_as_xid_rsp - builds XID response PDU 397 * @skb: Address of the skb to build 398 * @svcs_supported: The class of the LLC (I or II) 399 * @rx_window: The size of the receive window of the LLC 400 * 401 * Builds a pdu frame as an XID response. 402 */ 403static inline void llc_pdu_init_as_xid_rsp(struct sk_buff *skb, 404 u8 svcs_supported, u8 rx_window) 405{ 406 struct llc_xid_info *xid_info; 407 struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb); 408 409 pdu->ctrl_1 = LLC_PDU_TYPE_U; 410 pdu->ctrl_1 |= LLC_1_PDU_CMD_XID; 411 pdu->ctrl_1 |= LLC_U_PF_BIT_MASK; 412 413 xid_info = (struct llc_xid_info *)(((u8 *)&pdu->ctrl_1) + 1); 414 xid_info->fmt_id = LLC_XID_FMT_ID; 415 xid_info->type = svcs_supported; 416 xid_info->rw = rx_window << 1; 417 skb_put(skb, sizeof(struct llc_xid_info)); 418} 419 420/* LLC Type 2 FRMR response information field format */ 421struct llc_frmr_info { 422 u16 rej_pdu_ctrl; /* bits 1-8 if U-PDU */ 423 u8 curr_ssv; /* current send state variable val */ 424 u8 curr_rsv; /* current receive state variable */ 425 u8 ind_bits; /* indicator bits set with macro */ 426} __packed; 427 428void llc_pdu_set_cmd_rsp(struct sk_buff *skb, u8 type); 429void llc_pdu_set_pf_bit(struct sk_buff *skb, u8 bit_value); 430void llc_pdu_decode_pf_bit(struct sk_buff *skb, u8 *pf_bit); 431void llc_pdu_init_as_disc_cmd(struct sk_buff *skb, u8 p_bit); 432void llc_pdu_init_as_i_cmd(struct sk_buff *skb, u8 p_bit, u8 ns, u8 nr); 433void llc_pdu_init_as_rej_cmd(struct sk_buff *skb, u8 p_bit, u8 nr); 434void llc_pdu_init_as_rnr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr); 435void llc_pdu_init_as_rr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr); 436void llc_pdu_init_as_sabme_cmd(struct sk_buff *skb, u8 p_bit); 437void llc_pdu_init_as_dm_rsp(struct sk_buff *skb, u8 f_bit); 438void llc_pdu_init_as_frmr_rsp(struct sk_buff *skb, struct llc_pdu_sn *prev_pdu, 439 u8 f_bit, u8 vs, u8 vr, u8 vzyxw); 440void llc_pdu_init_as_rr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr); 441void llc_pdu_init_as_rej_rsp(struct sk_buff *skb, u8 f_bit, u8 nr); 442void llc_pdu_init_as_rnr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr); 443void llc_pdu_init_as_ua_rsp(struct sk_buff *skb, u8 f_bit); 444#endif /* LLC_PDU_H */ 445