Hansjoerg Lipp | 07dc1f9 | 2006-03-26 01:38:37 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Common data handling layer for ser_gigaset and usb_gigaset |
| 3 | * |
| 4 | * Copyright (c) 2005 by Tilman Schmidt <tilman@imap.cc>, |
| 5 | * Hansjoerg Lipp <hjlipp@web.de>, |
| 6 | * Stefan Eilers <Eilers.Stefan@epost.de>. |
| 7 | * |
| 8 | * ===================================================================== |
| 9 | * This program is free software; you can redistribute it and/or |
| 10 | * modify it under the terms of the GNU General Public License as |
| 11 | * published by the Free Software Foundation; either version 2 of |
| 12 | * the License, or (at your option) any later version. |
| 13 | * ===================================================================== |
| 14 | * ToDo: ... |
| 15 | * ===================================================================== |
| 16 | * Version: $Id: asyncdata.c,v 1.2.2.7 2005/11/13 23:05:18 hjlipp Exp $ |
| 17 | * ===================================================================== |
| 18 | */ |
| 19 | |
| 20 | #include "gigaset.h" |
| 21 | #include <linux/crc-ccitt.h> |
| 22 | |
| 23 | //#define GIG_M10x_STUFF_VOICE_DATA |
| 24 | |
| 25 | /* check if byte must be stuffed/escaped |
| 26 | * I'm not sure which data should be encoded. |
| 27 | * Therefore I will go the hard way and decode every value |
| 28 | * less than 0x20, the flag sequence and the control escape char. |
| 29 | */ |
| 30 | static inline int muststuff(unsigned char c) |
| 31 | { |
| 32 | if (c < PPP_TRANS) return 1; |
| 33 | if (c == PPP_FLAG) return 1; |
| 34 | if (c == PPP_ESCAPE) return 1; |
| 35 | /* other possible candidates: */ |
| 36 | /* 0x91: XON with parity set */ |
| 37 | /* 0x93: XOFF with parity set */ |
| 38 | return 0; |
| 39 | } |
| 40 | |
| 41 | /* == data input =========================================================== */ |
| 42 | |
| 43 | /* process a block of received bytes in command mode (modem response) |
| 44 | * Return value: |
| 45 | * number of processed bytes |
| 46 | */ |
| 47 | static inline int cmd_loop(unsigned char c, unsigned char *src, int numbytes, |
| 48 | struct inbuf_t *inbuf) |
| 49 | { |
| 50 | struct cardstate *cs = inbuf->cs; |
| 51 | unsigned cbytes = cs->cbytes; |
| 52 | int inputstate = inbuf->inputstate; |
| 53 | int startbytes = numbytes; |
| 54 | |
| 55 | for (;;) { |
| 56 | cs->respdata[cbytes] = c; |
| 57 | if (c == 10 || c == 13) { |
| 58 | dbg(DEBUG_TRANSCMD, "%s: End of Command (%d Bytes)", |
| 59 | __func__, cbytes); |
| 60 | cs->cbytes = cbytes; |
| 61 | gigaset_handle_modem_response(cs); /* can change cs->dle */ |
| 62 | cbytes = 0; |
| 63 | |
| 64 | if (cs->dle && |
| 65 | !(inputstate & INS_DLE_command)) { |
| 66 | inputstate &= ~INS_command; |
| 67 | break; |
| 68 | } |
| 69 | } else { |
| 70 | /* advance in line buffer, checking for overflow */ |
| 71 | if (cbytes < MAX_RESP_SIZE - 1) |
| 72 | cbytes++; |
| 73 | else |
| 74 | warn("response too large"); |
| 75 | } |
| 76 | |
| 77 | if (!numbytes) |
| 78 | break; |
| 79 | c = *src++; |
| 80 | --numbytes; |
| 81 | if (c == DLE_FLAG && |
| 82 | (cs->dle || inputstate & INS_DLE_command)) { |
| 83 | inputstate |= INS_DLE_char; |
| 84 | break; |
| 85 | } |
| 86 | } |
| 87 | |
| 88 | cs->cbytes = cbytes; |
| 89 | inbuf->inputstate = inputstate; |
| 90 | |
| 91 | return startbytes - numbytes; |
| 92 | } |
| 93 | |
| 94 | /* process a block of received bytes in lock mode (tty i/f) |
| 95 | * Return value: |
| 96 | * number of processed bytes |
| 97 | */ |
| 98 | static inline int lock_loop(unsigned char *src, int numbytes, |
| 99 | struct inbuf_t *inbuf) |
| 100 | { |
| 101 | struct cardstate *cs = inbuf->cs; |
| 102 | |
| 103 | gigaset_dbg_buffer(DEBUG_LOCKCMD, "received response", numbytes, src, 0); |
| 104 | gigaset_if_receive(cs, src, numbytes); |
| 105 | |
| 106 | return numbytes; |
| 107 | } |
| 108 | |
| 109 | /* process a block of received bytes in HDLC data mode |
| 110 | * Collect HDLC frames, undoing byte stuffing and watching for DLE escapes. |
| 111 | * When a frame is complete, check the FCS and pass valid frames to the LL. |
| 112 | * If DLE is encountered, return immediately to let the caller handle it. |
| 113 | * Return value: |
| 114 | * number of processed bytes |
| 115 | * numbytes (all bytes processed) on error --FIXME |
| 116 | */ |
| 117 | static inline int hdlc_loop(unsigned char c, unsigned char *src, int numbytes, |
| 118 | struct inbuf_t *inbuf) |
| 119 | { |
| 120 | struct cardstate *cs = inbuf->cs; |
| 121 | struct bc_state *bcs = inbuf->bcs; |
| 122 | int inputstate; |
| 123 | __u16 fcs; |
| 124 | struct sk_buff *skb; |
| 125 | unsigned char error; |
| 126 | struct sk_buff *compskb; |
| 127 | int startbytes = numbytes; |
| 128 | int l; |
| 129 | |
| 130 | IFNULLRETVAL(bcs, numbytes); |
| 131 | inputstate = bcs->inputstate; |
| 132 | fcs = bcs->fcs; |
| 133 | skb = bcs->skb; |
| 134 | IFNULLRETVAL(skb, numbytes); |
| 135 | |
| 136 | if (unlikely(inputstate & INS_byte_stuff)) { |
| 137 | inputstate &= ~INS_byte_stuff; |
| 138 | goto byte_stuff; |
| 139 | } |
| 140 | for (;;) { |
| 141 | if (unlikely(c == PPP_ESCAPE)) { |
| 142 | if (unlikely(!numbytes)) { |
| 143 | inputstate |= INS_byte_stuff; |
| 144 | break; |
| 145 | } |
| 146 | c = *src++; |
| 147 | --numbytes; |
| 148 | if (unlikely(c == DLE_FLAG && |
| 149 | (cs->dle || |
| 150 | inbuf->inputstate & INS_DLE_command))) { |
| 151 | inbuf->inputstate |= INS_DLE_char; |
| 152 | inputstate |= INS_byte_stuff; |
| 153 | break; |
| 154 | } |
| 155 | byte_stuff: |
| 156 | c ^= PPP_TRANS; |
| 157 | #ifdef CONFIG_GIGASET_DEBUG |
| 158 | if (unlikely(!muststuff(c))) |
| 159 | dbg(DEBUG_HDLC, |
| 160 | "byte stuffed: 0x%02x", c); |
| 161 | #endif |
| 162 | } else if (unlikely(c == PPP_FLAG)) { |
| 163 | if (unlikely(inputstate & INS_skip_frame)) { |
| 164 | if (!(inputstate & INS_have_data)) { /* 7E 7E */ |
| 165 | //dbg(DEBUG_HDLC, "(7e)7e------------------------"); |
| 166 | #ifdef CONFIG_GIGASET_DEBUG |
| 167 | ++bcs->emptycount; |
| 168 | #endif |
| 169 | } else |
| 170 | dbg(DEBUG_HDLC, |
| 171 | "7e----------------------------"); |
| 172 | |
| 173 | /* end of frame */ |
| 174 | error = 1; |
| 175 | gigaset_rcv_error(NULL, cs, bcs); |
| 176 | } else if (!(inputstate & INS_have_data)) { /* 7E 7E */ |
| 177 | //dbg(DEBUG_HDLC, "(7e)7e------------------------"); |
| 178 | #ifdef CONFIG_GIGASET_DEBUG |
| 179 | ++bcs->emptycount; |
| 180 | #endif |
| 181 | break; |
| 182 | } else { |
| 183 | dbg(DEBUG_HDLC, |
| 184 | "7e----------------------------"); |
| 185 | |
| 186 | /* end of frame */ |
| 187 | error = 0; |
| 188 | |
| 189 | if (unlikely(fcs != PPP_GOODFCS)) { |
| 190 | err("Packet checksum at %lu failed, " |
| 191 | "packet is corrupted (%u bytes)!", |
| 192 | bcs->rcvbytes, skb->len); |
| 193 | compskb = NULL; |
| 194 | gigaset_rcv_error(compskb, cs, bcs); |
| 195 | error = 1; |
| 196 | } else { |
| 197 | if (likely((l = skb->len) > 2)) { |
| 198 | skb->tail -= 2; |
| 199 | skb->len -= 2; |
| 200 | } else { |
| 201 | dev_kfree_skb(skb); |
| 202 | skb = NULL; |
| 203 | inputstate |= INS_skip_frame; |
| 204 | if (l == 1) { |
| 205 | err("invalid packet size (1)!"); |
| 206 | error = 1; |
| 207 | gigaset_rcv_error(NULL, cs, bcs); |
| 208 | } |
| 209 | } |
| 210 | if (likely(!(error || |
| 211 | (inputstate & |
| 212 | INS_skip_frame)))) { |
| 213 | gigaset_rcv_skb(skb, cs, bcs); |
| 214 | } |
| 215 | } |
| 216 | } |
| 217 | |
| 218 | if (unlikely(error)) |
| 219 | if (skb) |
| 220 | dev_kfree_skb(skb); |
| 221 | |
| 222 | fcs = PPP_INITFCS; |
| 223 | inputstate &= ~(INS_have_data | INS_skip_frame); |
| 224 | if (unlikely(bcs->ignore)) { |
| 225 | inputstate |= INS_skip_frame; |
| 226 | skb = NULL; |
| 227 | } else if (likely((skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL)) { |
| 228 | skb_reserve(skb, HW_HDR_LEN); |
| 229 | } else { |
| 230 | warn("could not allocate new skb"); |
| 231 | inputstate |= INS_skip_frame; |
| 232 | } |
| 233 | |
| 234 | break; |
| 235 | #ifdef CONFIG_GIGASET_DEBUG |
| 236 | } else if (unlikely(muststuff(c))) { |
| 237 | /* Should not happen. Possible after ZDLE=1<CR><LF>. */ |
| 238 | dbg(DEBUG_HDLC, "not byte stuffed: 0x%02x", c); |
| 239 | #endif |
| 240 | } |
| 241 | |
| 242 | /* add character */ |
| 243 | |
| 244 | #ifdef CONFIG_GIGASET_DEBUG |
| 245 | if (unlikely(!(inputstate & INS_have_data))) { |
| 246 | dbg(DEBUG_HDLC, |
| 247 | "7e (%d x) ================", bcs->emptycount); |
| 248 | bcs->emptycount = 0; |
| 249 | } |
| 250 | #endif |
| 251 | |
| 252 | inputstate |= INS_have_data; |
| 253 | |
| 254 | if (likely(!(inputstate & INS_skip_frame))) { |
| 255 | if (unlikely(skb->len == SBUFSIZE)) { |
| 256 | warn("received packet too long"); |
| 257 | dev_kfree_skb_any(skb); |
| 258 | skb = NULL; |
| 259 | inputstate |= INS_skip_frame; |
| 260 | break; |
| 261 | } |
| 262 | *gigaset_skb_put_quick(skb, 1) = c; |
| 263 | /* *__skb_put (skb, 1) = c; */ |
| 264 | fcs = crc_ccitt_byte(fcs, c); |
| 265 | } |
| 266 | |
| 267 | if (unlikely(!numbytes)) |
| 268 | break; |
| 269 | c = *src++; |
| 270 | --numbytes; |
| 271 | if (unlikely(c == DLE_FLAG && |
| 272 | (cs->dle || |
| 273 | inbuf->inputstate & INS_DLE_command))) { |
| 274 | inbuf->inputstate |= INS_DLE_char; |
| 275 | break; |
| 276 | } |
| 277 | } |
| 278 | bcs->inputstate = inputstate; |
| 279 | bcs->fcs = fcs; |
| 280 | bcs->skb = skb; |
| 281 | return startbytes - numbytes; |
| 282 | } |
| 283 | |
| 284 | /* process a block of received bytes in transparent data mode |
| 285 | * Invert bytes, undoing byte stuffing and watching for DLE escapes. |
| 286 | * If DLE is encountered, return immediately to let the caller handle it. |
| 287 | * Return value: |
| 288 | * number of processed bytes |
| 289 | * numbytes (all bytes processed) on error --FIXME |
| 290 | */ |
| 291 | static inline int iraw_loop(unsigned char c, unsigned char *src, int numbytes, |
| 292 | struct inbuf_t *inbuf) |
| 293 | { |
| 294 | struct cardstate *cs = inbuf->cs; |
| 295 | struct bc_state *bcs = inbuf->bcs; |
| 296 | int inputstate; |
| 297 | struct sk_buff *skb; |
| 298 | int startbytes = numbytes; |
| 299 | |
| 300 | IFNULLRETVAL(bcs, numbytes); |
| 301 | inputstate = bcs->inputstate; |
| 302 | skb = bcs->skb; |
| 303 | IFNULLRETVAL(skb, numbytes); |
| 304 | |
| 305 | for (;;) { |
| 306 | /* add character */ |
| 307 | inputstate |= INS_have_data; |
| 308 | |
| 309 | if (likely(!(inputstate & INS_skip_frame))) { |
| 310 | if (unlikely(skb->len == SBUFSIZE)) { |
| 311 | //FIXME just pass skb up and allocate a new one |
| 312 | warn("received packet too long"); |
| 313 | dev_kfree_skb_any(skb); |
| 314 | skb = NULL; |
| 315 | inputstate |= INS_skip_frame; |
| 316 | break; |
| 317 | } |
| 318 | *gigaset_skb_put_quick(skb, 1) = gigaset_invtab[c]; |
| 319 | } |
| 320 | |
| 321 | if (unlikely(!numbytes)) |
| 322 | break; |
| 323 | c = *src++; |
| 324 | --numbytes; |
| 325 | if (unlikely(c == DLE_FLAG && |
| 326 | (cs->dle || |
| 327 | inbuf->inputstate & INS_DLE_command))) { |
| 328 | inbuf->inputstate |= INS_DLE_char; |
| 329 | break; |
| 330 | } |
| 331 | } |
| 332 | |
| 333 | /* pass data up */ |
| 334 | if (likely(inputstate & INS_have_data)) { |
| 335 | if (likely(!(inputstate & INS_skip_frame))) { |
| 336 | gigaset_rcv_skb(skb, cs, bcs); |
| 337 | } |
| 338 | inputstate &= ~(INS_have_data | INS_skip_frame); |
| 339 | if (unlikely(bcs->ignore)) { |
| 340 | inputstate |= INS_skip_frame; |
| 341 | skb = NULL; |
| 342 | } else if (likely((skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) |
| 343 | != NULL)) { |
| 344 | skb_reserve(skb, HW_HDR_LEN); |
| 345 | } else { |
| 346 | warn("could not allocate new skb"); |
| 347 | inputstate |= INS_skip_frame; |
| 348 | } |
| 349 | } |
| 350 | |
| 351 | bcs->inputstate = inputstate; |
| 352 | bcs->skb = skb; |
| 353 | return startbytes - numbytes; |
| 354 | } |
| 355 | |
| 356 | /* process a block of data received from the device |
| 357 | */ |
| 358 | void gigaset_m10x_input(struct inbuf_t *inbuf) |
| 359 | { |
| 360 | struct cardstate *cs; |
| 361 | unsigned tail, head, numbytes; |
| 362 | unsigned char *src, c; |
| 363 | int procbytes; |
| 364 | |
| 365 | head = atomic_read(&inbuf->head); |
| 366 | tail = atomic_read(&inbuf->tail); |
| 367 | dbg(DEBUG_INTR, "buffer state: %u -> %u", head, tail); |
| 368 | |
| 369 | if (head != tail) { |
| 370 | cs = inbuf->cs; |
| 371 | src = inbuf->data + head; |
| 372 | numbytes = (head > tail ? RBUFSIZE : tail) - head; |
| 373 | dbg(DEBUG_INTR, "processing %u bytes", numbytes); |
| 374 | |
| 375 | while (numbytes) { |
| 376 | if (atomic_read(&cs->mstate) == MS_LOCKED) { |
| 377 | procbytes = lock_loop(src, numbytes, inbuf); |
| 378 | src += procbytes; |
| 379 | numbytes -= procbytes; |
| 380 | } else { |
| 381 | c = *src++; |
| 382 | --numbytes; |
| 383 | if (c == DLE_FLAG && (cs->dle || |
| 384 | inbuf->inputstate & INS_DLE_command)) { |
| 385 | if (!(inbuf->inputstate & INS_DLE_char)) { |
| 386 | inbuf->inputstate |= INS_DLE_char; |
| 387 | goto nextbyte; |
| 388 | } |
| 389 | /* <DLE> <DLE> => <DLE> in data stream */ |
| 390 | inbuf->inputstate &= ~INS_DLE_char; |
| 391 | } |
| 392 | |
| 393 | if (!(inbuf->inputstate & INS_DLE_char)) { |
| 394 | |
| 395 | /* FIXME Einfach je nach Modus Funktionszeiger in cs setzen [hier+hdlc_loop]? */ |
| 396 | /* FIXME Spart folgendes "if" und ermoeglicht andere Protokolle */ |
| 397 | if (inbuf->inputstate & INS_command) |
| 398 | procbytes = cmd_loop(c, src, numbytes, inbuf); |
| 399 | else if (inbuf->bcs->proto2 == ISDN_PROTO_L2_HDLC) |
| 400 | procbytes = hdlc_loop(c, src, numbytes, inbuf); |
| 401 | else |
| 402 | procbytes = iraw_loop(c, src, numbytes, inbuf); |
| 403 | |
| 404 | src += procbytes; |
| 405 | numbytes -= procbytes; |
| 406 | } else { /* DLE-char */ |
| 407 | inbuf->inputstate &= ~INS_DLE_char; |
| 408 | switch (c) { |
| 409 | case 'X': /*begin of command*/ |
| 410 | #ifdef CONFIG_GIGASET_DEBUG |
| 411 | if (inbuf->inputstate & INS_command) |
| 412 | err("received <DLE> 'X' in command mode"); |
| 413 | #endif |
| 414 | inbuf->inputstate |= |
| 415 | INS_command | INS_DLE_command; |
| 416 | break; |
| 417 | case '.': /*end of command*/ |
| 418 | #ifdef CONFIG_GIGASET_DEBUG |
| 419 | if (!(inbuf->inputstate & INS_command)) |
| 420 | err("received <DLE> '.' in hdlc mode"); |
| 421 | #endif |
| 422 | inbuf->inputstate &= cs->dle ? |
| 423 | ~(INS_DLE_command|INS_command) |
| 424 | : ~INS_DLE_command; |
| 425 | break; |
| 426 | //case DLE_FLAG: /*DLE_FLAG in data stream*/ /* schon oben behandelt! */ |
| 427 | default: |
| 428 | err("received 0x10 0x%02x!", (int) c); |
| 429 | /* FIXME: reset driver?? */ |
| 430 | } |
| 431 | } |
| 432 | } |
| 433 | nextbyte: |
| 434 | if (!numbytes) { |
| 435 | /* end of buffer, check for wrap */ |
| 436 | if (head > tail) { |
| 437 | head = 0; |
| 438 | src = inbuf->data; |
| 439 | numbytes = tail; |
| 440 | } else { |
| 441 | head = tail; |
| 442 | break; |
| 443 | } |
| 444 | } |
| 445 | } |
| 446 | |
| 447 | dbg(DEBUG_INTR, "setting head to %u", head); |
| 448 | atomic_set(&inbuf->head, head); |
| 449 | } |
| 450 | } |
| 451 | |
| 452 | |
| 453 | /* == data output ========================================================== */ |
| 454 | |
| 455 | /* Encoding of a PPP packet into an octet stuffed HDLC frame |
| 456 | * with FCS, opening and closing flags. |
| 457 | * parameters: |
| 458 | * skb skb containing original packet (freed upon return) |
| 459 | * head number of headroom bytes to allocate in result skb |
| 460 | * tail number of tailroom bytes to allocate in result skb |
| 461 | * Return value: |
| 462 | * pointer to newly allocated skb containing the result frame |
| 463 | */ |
| 464 | static struct sk_buff *HDLC_Encode(struct sk_buff *skb, int head, int tail) |
| 465 | { |
| 466 | struct sk_buff *hdlc_skb; |
| 467 | __u16 fcs; |
| 468 | unsigned char c; |
| 469 | unsigned char *cp; |
| 470 | int len; |
| 471 | unsigned int stuf_cnt; |
| 472 | |
| 473 | stuf_cnt = 0; |
| 474 | fcs = PPP_INITFCS; |
| 475 | cp = skb->data; |
| 476 | len = skb->len; |
| 477 | while (len--) { |
| 478 | if (muststuff(*cp)) |
| 479 | stuf_cnt++; |
| 480 | fcs = crc_ccitt_byte(fcs, *cp++); |
| 481 | } |
| 482 | fcs ^= 0xffff; /* complement */ |
| 483 | |
| 484 | /* size of new buffer: original size + number of stuffing bytes |
| 485 | * + 2 bytes FCS + 2 stuffing bytes for FCS (if needed) + 2 flag bytes |
| 486 | */ |
| 487 | hdlc_skb = dev_alloc_skb(skb->len + stuf_cnt + 6 + tail + head); |
| 488 | if (!hdlc_skb) { |
| 489 | err("unable to allocate memory for HDLC encoding!"); |
| 490 | dev_kfree_skb(skb); |
| 491 | return NULL; |
| 492 | } |
| 493 | skb_reserve(hdlc_skb, head); |
| 494 | |
| 495 | /* Copy acknowledge request into new skb */ |
| 496 | memcpy(hdlc_skb->head, skb->head, 2); |
| 497 | |
| 498 | /* Add flag sequence in front of everything.. */ |
| 499 | *(skb_put(hdlc_skb, 1)) = PPP_FLAG; |
| 500 | |
| 501 | /* Perform byte stuffing while copying data. */ |
| 502 | while (skb->len--) { |
| 503 | if (muststuff(*skb->data)) { |
| 504 | *(skb_put(hdlc_skb, 1)) = PPP_ESCAPE; |
| 505 | *(skb_put(hdlc_skb, 1)) = (*skb->data++) ^ PPP_TRANS; |
| 506 | } else |
| 507 | *(skb_put(hdlc_skb, 1)) = *skb->data++; |
| 508 | } |
| 509 | |
| 510 | /* Finally add FCS (byte stuffed) and flag sequence */ |
| 511 | c = (fcs & 0x00ff); /* least significant byte first */ |
| 512 | if (muststuff(c)) { |
| 513 | *(skb_put(hdlc_skb, 1)) = PPP_ESCAPE; |
| 514 | c ^= PPP_TRANS; |
| 515 | } |
| 516 | *(skb_put(hdlc_skb, 1)) = c; |
| 517 | |
| 518 | c = ((fcs >> 8) & 0x00ff); |
| 519 | if (muststuff(c)) { |
| 520 | *(skb_put(hdlc_skb, 1)) = PPP_ESCAPE; |
| 521 | c ^= PPP_TRANS; |
| 522 | } |
| 523 | *(skb_put(hdlc_skb, 1)) = c; |
| 524 | |
| 525 | *(skb_put(hdlc_skb, 1)) = PPP_FLAG; |
| 526 | |
| 527 | dev_kfree_skb(skb); |
| 528 | return hdlc_skb; |
| 529 | } |
| 530 | |
| 531 | /* Encoding of a raw packet into an octet stuffed bit inverted frame |
| 532 | * parameters: |
| 533 | * skb skb containing original packet (freed upon return) |
| 534 | * head number of headroom bytes to allocate in result skb |
| 535 | * tail number of tailroom bytes to allocate in result skb |
| 536 | * Return value: |
| 537 | * pointer to newly allocated skb containing the result frame |
| 538 | */ |
| 539 | static struct sk_buff *iraw_encode(struct sk_buff *skb, int head, int tail) |
| 540 | { |
| 541 | struct sk_buff *iraw_skb; |
| 542 | unsigned char c; |
| 543 | unsigned char *cp; |
| 544 | int len; |
| 545 | |
| 546 | /* worst case: every byte must be stuffed */ |
| 547 | iraw_skb = dev_alloc_skb(2*skb->len + tail + head); |
| 548 | if (!iraw_skb) { |
| 549 | err("unable to allocate memory for HDLC encoding!"); |
| 550 | dev_kfree_skb(skb); |
| 551 | return NULL; |
| 552 | } |
| 553 | skb_reserve(iraw_skb, head); |
| 554 | |
| 555 | cp = skb->data; |
| 556 | len = skb->len; |
| 557 | while (len--) { |
| 558 | c = gigaset_invtab[*cp++]; |
| 559 | if (c == DLE_FLAG) |
| 560 | *(skb_put(iraw_skb, 1)) = c; |
| 561 | *(skb_put(iraw_skb, 1)) = c; |
| 562 | } |
| 563 | dev_kfree_skb(skb); |
| 564 | return iraw_skb; |
| 565 | } |
| 566 | |
| 567 | /* gigaset_send_skb |
| 568 | * called by common.c to queue an skb for sending |
| 569 | * and start transmission if necessary |
| 570 | * parameters: |
| 571 | * B Channel control structure |
| 572 | * skb |
| 573 | * Return value: |
| 574 | * number of bytes accepted for sending |
| 575 | * (skb->len if ok, 0 if out of buffer space) |
| 576 | * or error code (< 0, eg. -EINVAL) |
| 577 | */ |
| 578 | int gigaset_m10x_send_skb(struct bc_state *bcs, struct sk_buff *skb) |
| 579 | { |
| 580 | unsigned len; |
| 581 | |
| 582 | IFNULLRETVAL(bcs, -EFAULT); |
| 583 | IFNULLRETVAL(skb, -EFAULT); |
| 584 | len = skb->len; |
| 585 | |
| 586 | if (bcs->proto2 == ISDN_PROTO_L2_HDLC) |
| 587 | skb = HDLC_Encode(skb, HW_HDR_LEN, 0); |
| 588 | else |
| 589 | skb = iraw_encode(skb, HW_HDR_LEN, 0); |
| 590 | if (!skb) |
| 591 | return -ENOMEM; |
| 592 | |
| 593 | skb_queue_tail(&bcs->squeue, skb); |
| 594 | tasklet_schedule(&bcs->cs->write_tasklet); |
| 595 | |
| 596 | return len; /* ok so far */ |
| 597 | } |