llc_pdu.h 14 KB

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  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. #include <linux/if_ether.h>
  15. #include <linux/if_tr.h>
  16. /* Lengths of frame formats */
  17. #define LLC_PDU_LEN_I 4 /* header and 2 control bytes */
  18. #define LLC_PDU_LEN_S 4
  19. #define LLC_PDU_LEN_U 3 /* header and 1 control byte */
  20. /* Known SAP addresses */
  21. #define LLC_GLOBAL_SAP 0xFF
  22. #define LLC_NULL_SAP 0x00 /* not network-layer visible */
  23. #define LLC_MGMT_INDIV 0x02 /* station LLC mgmt indiv addr */
  24. #define LLC_MGMT_GRP 0x03 /* station LLC mgmt group addr */
  25. #define LLC_RDE_SAP 0xA6 /* route ... */
  26. /* SAP field bit masks */
  27. #define LLC_ISO_RESERVED_SAP 0x02
  28. #define LLC_SAP_GROUP_DSAP 0x01
  29. #define LLC_SAP_RESP_SSAP 0x01
  30. /* Group/individual DSAP indicator is DSAP field */
  31. #define LLC_PDU_GROUP_DSAP_MASK 0x01
  32. #define LLC_PDU_IS_GROUP_DSAP(pdu) \
  33. ((pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1)
  34. #define LLC_PDU_IS_INDIV_DSAP(pdu) \
  35. (!(pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1)
  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. /* Get PDU type from 2 lowest-order bits of control field first byte */
  43. #define LLC_PDU_TYPE_I_MASK 0x01 /* 16-bit control field */
  44. #define LLC_PDU_TYPE_S_MASK 0x03
  45. #define LLC_PDU_TYPE_U_MASK 0x03 /* 8-bit control field */
  46. #define LLC_PDU_TYPE_MASK 0x03
  47. #define LLC_PDU_TYPE_I 0 /* first bit */
  48. #define LLC_PDU_TYPE_S 1 /* first two bits */
  49. #define LLC_PDU_TYPE_U 3 /* first two bits */
  50. #define LLC_PDU_TYPE_IS_I(pdu) \
  51. ((!(pdu->ctrl_1 & LLC_PDU_TYPE_I_MASK)) ? 1 : 0)
  52. #define LLC_PDU_TYPE_IS_U(pdu) \
  53. (((pdu->ctrl_1 & LLC_PDU_TYPE_U_MASK) == LLC_PDU_TYPE_U) ? 1 : 0)
  54. #define LLC_PDU_TYPE_IS_S(pdu) \
  55. (((pdu->ctrl_1 & LLC_PDU_TYPE_S_MASK) == LLC_PDU_TYPE_S) ? 1 : 0)
  56. /* U-format PDU control field masks */
  57. #define LLC_U_PF_BIT_MASK 0x10 /* P/F bit mask */
  58. #define LLC_U_PF_IS_1(pdu) ((pdu->ctrl_1 & LLC_U_PF_BIT_MASK) ? 1 : 0)
  59. #define LLC_U_PF_IS_0(pdu) ((!(pdu->ctrl_1 & LLC_U_PF_BIT_MASK)) ? 1 : 0)
  60. #define LLC_U_PDU_CMD_MASK 0xEC /* cmd/rsp mask */
  61. #define LLC_U_PDU_CMD(pdu) (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK)
  62. #define LLC_U_PDU_RSP(pdu) (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK)
  63. #define LLC_1_PDU_CMD_UI 0x00 /* Type 1 cmds/rsps */
  64. #define LLC_1_PDU_CMD_XID 0xAC
  65. #define LLC_1_PDU_CMD_TEST 0xE0
  66. #define LLC_2_PDU_CMD_SABME 0x6C /* Type 2 cmds/rsps */
  67. #define LLC_2_PDU_CMD_DISC 0x40
  68. #define LLC_2_PDU_RSP_UA 0x60
  69. #define LLC_2_PDU_RSP_DM 0x0C
  70. #define LLC_2_PDU_RSP_FRMR 0x84
  71. /* Type 1 operations */
  72. /* XID information field bit masks */
  73. /* LLC format identifier (byte 1) */
  74. #define LLC_XID_FMT_ID 0x81 /* first byte must be this */
  75. /* LLC types/classes identifier (byte 2) */
  76. #define LLC_XID_CLASS_ZEROS_MASK 0xE0 /* these must be zeros */
  77. #define LLC_XID_CLASS_MASK 0x1F /* AND with byte to get below */
  78. #define LLC_XID_NULL_CLASS_1 0x01 /* if NULL LSAP...use these */
  79. #define LLC_XID_NULL_CLASS_2 0x03
  80. #define LLC_XID_NULL_CLASS_3 0x05
  81. #define LLC_XID_NULL_CLASS_4 0x07
  82. #define LLC_XID_NNULL_TYPE_1 0x01 /* if non-NULL LSAP...use these */
  83. #define LLC_XID_NNULL_TYPE_2 0x02
  84. #define LLC_XID_NNULL_TYPE_3 0x04
  85. #define LLC_XID_NNULL_TYPE_1_2 0x03
  86. #define LLC_XID_NNULL_TYPE_1_3 0x05
  87. #define LLC_XID_NNULL_TYPE_2_3 0x06
  88. #define LLC_XID_NNULL_ALL 0x07
  89. /* Sender Receive Window (byte 3) */
  90. #define LLC_XID_RW_MASK 0xFE /* AND with value to get below */
  91. #define LLC_XID_MIN_RW 0x02 /* lowest-order bit always zero */
  92. /* Type 2 operations */
  93. #define LLC_2_SEQ_NBR_MODULO ((u8) 128)
  94. /* I-PDU masks ('ctrl' is I-PDU control word) */
  95. #define LLC_I_GET_NS(pdu) (u8)((pdu->ctrl_1 & 0xFE) >> 1)
  96. #define LLC_I_GET_NR(pdu) (u8)((pdu->ctrl_2 & 0xFE) >> 1)
  97. #define LLC_I_PF_BIT_MASK 0x01
  98. #define LLC_I_PF_IS_0(pdu) ((!(pdu->ctrl_2 & LLC_I_PF_BIT_MASK)) ? 1 : 0)
  99. #define LLC_I_PF_IS_1(pdu) ((pdu->ctrl_2 & LLC_I_PF_BIT_MASK) ? 1 : 0)
  100. /* S-PDU supervisory commands and responses */
  101. #define LLC_S_PDU_CMD_MASK 0x0C
  102. #define LLC_S_PDU_CMD(pdu) (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK)
  103. #define LLC_S_PDU_RSP(pdu) (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK)
  104. #define LLC_2_PDU_CMD_RR 0x00 /* rx ready cmd */
  105. #define LLC_2_PDU_RSP_RR 0x00 /* rx ready rsp */
  106. #define LLC_2_PDU_CMD_REJ 0x08 /* reject PDU cmd */
  107. #define LLC_2_PDU_RSP_REJ 0x08 /* reject PDU rsp */
  108. #define LLC_2_PDU_CMD_RNR 0x04 /* rx not ready cmd */
  109. #define LLC_2_PDU_RSP_RNR 0x04 /* rx not ready rsp */
  110. #define LLC_S_PF_BIT_MASK 0x01
  111. #define LLC_S_PF_IS_0(pdu) ((!(pdu->ctrl_2 & LLC_S_PF_BIT_MASK)) ? 1 : 0)
  112. #define LLC_S_PF_IS_1(pdu) ((pdu->ctrl_2 & LLC_S_PF_BIT_MASK) ? 1 : 0)
  113. #define PDU_SUPV_GET_Nr(pdu) ((pdu->ctrl_2 & 0xFE) >> 1)
  114. #define PDU_GET_NEXT_Vr(sn) (++sn & ~LLC_2_SEQ_NBR_MODULO)
  115. /* FRMR information field macros */
  116. #define FRMR_INFO_LENGTH 5 /* 5 bytes of information */
  117. /*
  118. * info is pointer to FRMR info field structure; 'rej_ctrl' is byte pointer
  119. * (if U-PDU) or word pointer to rejected PDU control field
  120. */
  121. #define FRMR_INFO_SET_REJ_CNTRL(info,rej_ctrl) \
  122. info->rej_pdu_ctrl = ((*((u8 *) rej_ctrl) & \
  123. LLC_PDU_TYPE_U) != LLC_PDU_TYPE_U ? \
  124. (u16)*((u16 *) rej_ctrl) : \
  125. (((u16) *((u8 *) rej_ctrl)) & 0x00FF))
  126. /*
  127. * Info is pointer to FRMR info field structure; 'vs' is a byte containing
  128. * send state variable value in low-order 7 bits (insure the lowest-order
  129. * bit remains zero (0))
  130. */
  131. #define FRMR_INFO_SET_Vs(info,vs) (info->curr_ssv = (((u8) vs) << 1))
  132. #define FRMR_INFO_SET_Vr(info,vr) (info->curr_rsv = (((u8) vr) << 1))
  133. /*
  134. * Info is pointer to FRMR info field structure; 'cr' is a byte containing
  135. * the C/R bit value in the low-order bit
  136. */
  137. #define FRMR_INFO_SET_C_R_BIT(info, cr) (info->curr_rsv |= (((u8) cr) & 0x01))
  138. /*
  139. * In the remaining five macros, 'info' is pointer to FRMR info field
  140. * structure; 'ind' is a byte containing the bit value to set in the
  141. * lowest-order bit)
  142. */
  143. #define FRMR_INFO_SET_INVALID_PDU_CTRL_IND(info, ind) \
  144. (info->ind_bits = ((info->ind_bits & 0xFE) | (((u8) ind) & 0x01)))
  145. #define FRMR_INFO_SET_INVALID_PDU_INFO_IND(info, ind) \
  146. (info->ind_bits = ( (info->ind_bits & 0xFD) | (((u8) ind) & 0x02)))
  147. #define FRMR_INFO_SET_PDU_INFO_2LONG_IND(info, ind) \
  148. (info->ind_bits = ( (info->ind_bits & 0xFB) | (((u8) ind) & 0x04)))
  149. #define FRMR_INFO_SET_PDU_INVALID_Nr_IND(info, ind) \
  150. (info->ind_bits = ( (info->ind_bits & 0xF7) | (((u8) ind) & 0x08)))
  151. #define FRMR_INFO_SET_PDU_INVALID_Ns_IND(info, ind) \
  152. (info->ind_bits = ( (info->ind_bits & 0xEF) | (((u8) ind) & 0x10)))
  153. /* Sequence-numbered PDU format (4 bytes in length) */
  154. struct llc_pdu_sn {
  155. u8 dsap;
  156. u8 ssap;
  157. u8 ctrl_1;
  158. u8 ctrl_2;
  159. };
  160. static inline struct llc_pdu_sn *llc_pdu_sn_hdr(struct sk_buff *skb)
  161. {
  162. return (struct llc_pdu_sn *)skb->nh.raw;
  163. }
  164. /* Un-numbered PDU format (3 bytes in length) */
  165. struct llc_pdu_un {
  166. u8 dsap;
  167. u8 ssap;
  168. u8 ctrl_1;
  169. };
  170. static inline struct llc_pdu_un *llc_pdu_un_hdr(struct sk_buff *skb)
  171. {
  172. return (struct llc_pdu_un *)skb->nh.raw;
  173. }
  174. static inline void *llc_set_pdu_hdr(struct sk_buff *skb, void *ptr)
  175. {
  176. return skb->nh.raw = ptr;
  177. }
  178. /**
  179. * llc_pdu_header_init - initializes pdu header
  180. * @skb: input skb that header must be set into it.
  181. * @type: type of PDU (U, I or S).
  182. * @ssap: source sap.
  183. * @dsap: destination sap.
  184. * @cr: command/response bit (0 or 1).
  185. *
  186. * This function sets DSAP, SSAP and command/Response bit in LLC header.
  187. */
  188. static inline void llc_pdu_header_init(struct sk_buff *skb, u8 type,
  189. u8 ssap, u8 dsap, u8 cr)
  190. {
  191. const int hlen = type == LLC_PDU_TYPE_U ? 3 : 4;
  192. struct llc_pdu_un *pdu = llc_set_pdu_hdr(skb, skb_push(skb, hlen));
  193. pdu->dsap = dsap;
  194. pdu->ssap = ssap;
  195. pdu->ssap |= cr;
  196. }
  197. /**
  198. * llc_pdu_decode_sa - extracs source address (MAC) of input frame
  199. * @skb: input skb that source address must be extracted from it.
  200. * @sa: pointer to source address (6 byte array).
  201. *
  202. * This function extracts source address(MAC) of input frame.
  203. */
  204. static inline void llc_pdu_decode_sa(struct sk_buff *skb, u8 *sa)
  205. {
  206. if (skb->protocol == htons(ETH_P_802_2))
  207. memcpy(sa, eth_hdr(skb)->h_source, ETH_ALEN);
  208. else if (skb->protocol == htons(ETH_P_TR_802_2)) {
  209. memcpy(sa, tr_hdr(skb)->saddr, ETH_ALEN);
  210. *sa &= 0x7F;
  211. }
  212. }
  213. /**
  214. * llc_pdu_decode_da - extracts dest address of input frame
  215. * @skb: input skb that destination address must be extracted from it
  216. * @sa: pointer to destination address (6 byte array).
  217. *
  218. * This function extracts destination address(MAC) of input frame.
  219. */
  220. static inline void llc_pdu_decode_da(struct sk_buff *skb, u8 *da)
  221. {
  222. if (skb->protocol == htons(ETH_P_802_2))
  223. memcpy(da, eth_hdr(skb)->h_dest, ETH_ALEN);
  224. else if (skb->protocol == htons(ETH_P_TR_802_2))
  225. memcpy(da, tr_hdr(skb)->daddr, ETH_ALEN);
  226. }
  227. /**
  228. * llc_pdu_decode_ssap - extracts source SAP of input frame
  229. * @skb: input skb that source SAP must be extracted from it.
  230. * @ssap: source SAP (output argument).
  231. *
  232. * This function extracts source SAP of input frame. Right bit of SSAP is
  233. * command/response bit.
  234. */
  235. static inline void llc_pdu_decode_ssap(struct sk_buff *skb, u8 *ssap)
  236. {
  237. *ssap = llc_pdu_un_hdr(skb)->ssap & 0xFE;
  238. }
  239. /**
  240. * llc_pdu_decode_dsap - extracts dest SAP of input frame
  241. * @skb: input skb that destination SAP must be extracted from it.
  242. * @dsap: destination SAP (output argument).
  243. *
  244. * This function extracts destination SAP of input frame. right bit of
  245. * DSAP designates individual/group SAP.
  246. */
  247. static inline void llc_pdu_decode_dsap(struct sk_buff *skb, u8 *dsap)
  248. {
  249. *dsap = llc_pdu_un_hdr(skb)->dsap & 0xFE;
  250. }
  251. /**
  252. * llc_pdu_init_as_ui_cmd - sets LLC header as UI PDU
  253. * @skb: input skb that header must be set into it.
  254. *
  255. * This function sets third byte of LLC header as a UI PDU.
  256. */
  257. static inline void llc_pdu_init_as_ui_cmd(struct sk_buff *skb)
  258. {
  259. struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
  260. pdu->ctrl_1 = LLC_PDU_TYPE_U;
  261. pdu->ctrl_1 |= LLC_1_PDU_CMD_UI;
  262. }
  263. /**
  264. * llc_pdu_init_as_test_cmd - sets PDU as TEST
  265. * @skb - Address of the skb to build
  266. *
  267. * Sets a PDU as TEST
  268. */
  269. static inline void llc_pdu_init_as_test_cmd(struct sk_buff *skb)
  270. {
  271. struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
  272. pdu->ctrl_1 = LLC_PDU_TYPE_U;
  273. pdu->ctrl_1 |= LLC_1_PDU_CMD_TEST;
  274. pdu->ctrl_1 |= LLC_U_PF_BIT_MASK;
  275. }
  276. /**
  277. * llc_pdu_init_as_test_rsp - build TEST response PDU
  278. * @skb: Address of the skb to build
  279. * @ev_skb: The received TEST command PDU frame
  280. *
  281. * Builds a pdu frame as a TEST response.
  282. */
  283. static inline void llc_pdu_init_as_test_rsp(struct sk_buff *skb,
  284. struct sk_buff *ev_skb)
  285. {
  286. struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
  287. pdu->ctrl_1 = LLC_PDU_TYPE_U;
  288. pdu->ctrl_1 |= LLC_1_PDU_CMD_TEST;
  289. pdu->ctrl_1 |= LLC_U_PF_BIT_MASK;
  290. if (ev_skb->protocol == htons(ETH_P_802_2)) {
  291. struct llc_pdu_un *ev_pdu = llc_pdu_un_hdr(ev_skb);
  292. int dsize;
  293. dsize = ntohs(eth_hdr(ev_skb)->h_proto) - 3;
  294. memcpy(((u8 *)pdu) + 3, ((u8 *)ev_pdu) + 3, dsize);
  295. skb_put(skb, dsize);
  296. }
  297. }
  298. /* LLC Type 1 XID command/response information fields format */
  299. struct llc_xid_info {
  300. u8 fmt_id; /* always 0x81 for LLC */
  301. u8 type; /* different if NULL/non-NULL LSAP */
  302. u8 rw; /* sender receive window */
  303. };
  304. /**
  305. * llc_pdu_init_as_xid_cmd - sets bytes 3, 4 & 5 of LLC header as XID
  306. * @skb: input skb that header must be set into it.
  307. *
  308. * This function sets third,fourth,fifth and sixth bytes of LLC header as
  309. * a XID PDU.
  310. */
  311. static inline void llc_pdu_init_as_xid_cmd(struct sk_buff *skb,
  312. u8 svcs_supported, u8 rx_window)
  313. {
  314. struct llc_xid_info *xid_info;
  315. struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
  316. pdu->ctrl_1 = LLC_PDU_TYPE_U;
  317. pdu->ctrl_1 |= LLC_1_PDU_CMD_XID;
  318. pdu->ctrl_1 |= LLC_U_PF_BIT_MASK;
  319. xid_info = (struct llc_xid_info *)(((u8 *)&pdu->ctrl_1) + 1);
  320. xid_info->fmt_id = LLC_XID_FMT_ID; /* 0x81 */
  321. xid_info->type = svcs_supported;
  322. xid_info->rw = rx_window << 1; /* size of receive window */
  323. skb_put(skb, 3);
  324. }
  325. /**
  326. * llc_pdu_init_as_xid_rsp - builds XID response PDU
  327. * @skb: Address of the skb to build
  328. * @svcs_supported: The class of the LLC (I or II)
  329. * @rx_window: The size of the receive window of the LLC
  330. *
  331. * Builds a pdu frame as an XID response.
  332. */
  333. static inline void llc_pdu_init_as_xid_rsp(struct sk_buff *skb,
  334. u8 svcs_supported, u8 rx_window)
  335. {
  336. struct llc_xid_info *xid_info;
  337. struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
  338. pdu->ctrl_1 = LLC_PDU_TYPE_U;
  339. pdu->ctrl_1 |= LLC_1_PDU_CMD_XID;
  340. pdu->ctrl_1 |= LLC_U_PF_BIT_MASK;
  341. xid_info = (struct llc_xid_info *)(((u8 *)&pdu->ctrl_1) + 1);
  342. xid_info->fmt_id = LLC_XID_FMT_ID;
  343. xid_info->type = svcs_supported;
  344. xid_info->rw = rx_window << 1;
  345. skb_put(skb, 3);
  346. }
  347. /* LLC Type 2 FRMR response information field format */
  348. struct llc_frmr_info {
  349. u16 rej_pdu_ctrl; /* bits 1-8 if U-PDU */
  350. u8 curr_ssv; /* current send state variable val */
  351. u8 curr_rsv; /* current receive state variable */
  352. u8 ind_bits; /* indicator bits set with macro */
  353. };
  354. extern void llc_pdu_set_cmd_rsp(struct sk_buff *skb, u8 type);
  355. extern void llc_pdu_set_pf_bit(struct sk_buff *skb, u8 bit_value);
  356. extern void llc_pdu_decode_pf_bit(struct sk_buff *skb, u8 *pf_bit);
  357. extern void llc_pdu_init_as_disc_cmd(struct sk_buff *skb, u8 p_bit);
  358. extern void llc_pdu_init_as_i_cmd(struct sk_buff *skb, u8 p_bit, u8 ns, u8 nr);
  359. extern void llc_pdu_init_as_rej_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
  360. extern void llc_pdu_init_as_rnr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
  361. extern void llc_pdu_init_as_rr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
  362. extern void llc_pdu_init_as_sabme_cmd(struct sk_buff *skb, u8 p_bit);
  363. extern void llc_pdu_init_as_dm_rsp(struct sk_buff *skb, u8 f_bit);
  364. extern void llc_pdu_init_as_frmr_rsp(struct sk_buff *skb,
  365. struct llc_pdu_sn *prev_pdu,
  366. u8 f_bit, u8 vs, u8 vr, u8 vzyxw);
  367. extern void llc_pdu_init_as_rr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
  368. extern void llc_pdu_init_as_rej_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
  369. extern void llc_pdu_init_as_rnr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
  370. extern void llc_pdu_init_as_ua_rsp(struct sk_buff *skb, u8 f_bit);
  371. #endif /* LLC_PDU_H */