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