591 lines
15 KiB
C
591 lines
15 KiB
C
/*
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* Common data handling layer for ser_gigaset and usb_gigaset
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*
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* Copyright (c) 2005 by Tilman Schmidt <tilman@imap.cc>,
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* Hansjoerg Lipp <hjlipp@web.de>,
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* Stefan Eilers.
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*
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* =====================================================================
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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* =====================================================================
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*/
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#include "gigaset.h"
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#include <linux/crc-ccitt.h>
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#include <linux/bitrev.h>
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//#define GIG_M10x_STUFF_VOICE_DATA
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/* check if byte must be stuffed/escaped
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* I'm not sure which data should be encoded.
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* Therefore I will go the hard way and decode every value
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* less than 0x20, the flag sequence and the control escape char.
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*/
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static inline int muststuff(unsigned char c)
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{
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if (c < PPP_TRANS) return 1;
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if (c == PPP_FLAG) return 1;
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if (c == PPP_ESCAPE) return 1;
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/* other possible candidates: */
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/* 0x91: XON with parity set */
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/* 0x93: XOFF with parity set */
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return 0;
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}
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/* == data input =========================================================== */
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/* process a block of received bytes in command mode (modem response)
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* Return value:
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* number of processed bytes
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*/
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static inline int cmd_loop(unsigned char c, unsigned char *src, int numbytes,
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struct inbuf_t *inbuf)
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{
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struct cardstate *cs = inbuf->cs;
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unsigned cbytes = cs->cbytes;
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int inputstate = inbuf->inputstate;
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int startbytes = numbytes;
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for (;;) {
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cs->respdata[cbytes] = c;
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if (c == 10 || c == 13) {
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gig_dbg(DEBUG_TRANSCMD, "%s: End of Command (%d Bytes)",
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__func__, cbytes);
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cs->cbytes = cbytes;
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gigaset_handle_modem_response(cs); /* can change
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cs->dle */
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cbytes = 0;
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if (cs->dle &&
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!(inputstate & INS_DLE_command)) {
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inputstate &= ~INS_command;
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break;
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}
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} else {
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/* advance in line buffer, checking for overflow */
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if (cbytes < MAX_RESP_SIZE - 1)
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cbytes++;
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else
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dev_warn(cs->dev, "response too large\n");
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}
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if (!numbytes)
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break;
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c = *src++;
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--numbytes;
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if (c == DLE_FLAG &&
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(cs->dle || inputstate & INS_DLE_command)) {
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inputstate |= INS_DLE_char;
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break;
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}
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}
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cs->cbytes = cbytes;
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inbuf->inputstate = inputstate;
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return startbytes - numbytes;
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}
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/* process a block of received bytes in lock mode (tty i/f)
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* Return value:
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* number of processed bytes
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*/
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static inline int lock_loop(unsigned char *src, int numbytes,
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struct inbuf_t *inbuf)
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{
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struct cardstate *cs = inbuf->cs;
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gigaset_dbg_buffer(DEBUG_LOCKCMD, "received response",
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numbytes, src);
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gigaset_if_receive(cs, src, numbytes);
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return numbytes;
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}
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/* process a block of received bytes in HDLC data mode
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* Collect HDLC frames, undoing byte stuffing and watching for DLE escapes.
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* When a frame is complete, check the FCS and pass valid frames to the LL.
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* If DLE is encountered, return immediately to let the caller handle it.
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* Return value:
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* number of processed bytes
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* numbytes (all bytes processed) on error --FIXME
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*/
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static inline int hdlc_loop(unsigned char c, unsigned char *src, int numbytes,
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struct inbuf_t *inbuf)
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{
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struct cardstate *cs = inbuf->cs;
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struct bc_state *bcs = inbuf->bcs;
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int inputstate = bcs->inputstate;
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__u16 fcs = bcs->fcs;
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struct sk_buff *skb = bcs->skb;
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unsigned char error;
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struct sk_buff *compskb;
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int startbytes = numbytes;
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int l;
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if (unlikely(inputstate & INS_byte_stuff)) {
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inputstate &= ~INS_byte_stuff;
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goto byte_stuff;
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}
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for (;;) {
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if (unlikely(c == PPP_ESCAPE)) {
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if (unlikely(!numbytes)) {
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inputstate |= INS_byte_stuff;
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break;
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}
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c = *src++;
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--numbytes;
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if (unlikely(c == DLE_FLAG &&
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(cs->dle ||
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inbuf->inputstate & INS_DLE_command))) {
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inbuf->inputstate |= INS_DLE_char;
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inputstate |= INS_byte_stuff;
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break;
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}
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byte_stuff:
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c ^= PPP_TRANS;
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#ifdef CONFIG_GIGASET_DEBUG
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if (unlikely(!muststuff(c)))
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gig_dbg(DEBUG_HDLC, "byte stuffed: 0x%02x", c);
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#endif
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} else if (unlikely(c == PPP_FLAG)) {
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if (unlikely(inputstate & INS_skip_frame)) {
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if (!(inputstate & INS_have_data)) { /* 7E 7E */
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#ifdef CONFIG_GIGASET_DEBUG
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++bcs->emptycount;
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#endif
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} else
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gig_dbg(DEBUG_HDLC,
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"7e----------------------------");
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/* end of frame */
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error = 1;
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gigaset_rcv_error(NULL, cs, bcs);
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} else if (!(inputstate & INS_have_data)) { /* 7E 7E */
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#ifdef CONFIG_GIGASET_DEBUG
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++bcs->emptycount;
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#endif
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break;
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} else {
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gig_dbg(DEBUG_HDLC,
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"7e----------------------------");
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/* end of frame */
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error = 0;
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if (unlikely(fcs != PPP_GOODFCS)) {
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dev_err(cs->dev,
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"Packet checksum at %lu failed, "
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"packet is corrupted (%u bytes)!\n",
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bcs->rcvbytes, skb->len);
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compskb = NULL;
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gigaset_rcv_error(compskb, cs, bcs);
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error = 1;
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} else {
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if (likely((l = skb->len) > 2)) {
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skb->tail -= 2;
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skb->len -= 2;
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} else {
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dev_kfree_skb(skb);
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skb = NULL;
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inputstate |= INS_skip_frame;
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if (l == 1) {
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dev_err(cs->dev,
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"invalid packet size (1)!\n");
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error = 1;
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gigaset_rcv_error(NULL,
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cs, bcs);
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}
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}
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if (likely(!(error ||
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(inputstate &
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INS_skip_frame)))) {
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gigaset_rcv_skb(skb, cs, bcs);
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}
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}
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}
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if (unlikely(error))
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if (skb)
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dev_kfree_skb(skb);
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fcs = PPP_INITFCS;
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inputstate &= ~(INS_have_data | INS_skip_frame);
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if (unlikely(bcs->ignore)) {
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inputstate |= INS_skip_frame;
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skb = NULL;
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} else if (likely((skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN)) != NULL)) {
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skb_reserve(skb, HW_HDR_LEN);
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} else {
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dev_warn(cs->dev,
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"could not allocate new skb\n");
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inputstate |= INS_skip_frame;
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}
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break;
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#ifdef CONFIG_GIGASET_DEBUG
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} else if (unlikely(muststuff(c))) {
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/* Should not happen. Possible after ZDLE=1<CR><LF>. */
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gig_dbg(DEBUG_HDLC, "not byte stuffed: 0x%02x", c);
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#endif
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}
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/* add character */
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#ifdef CONFIG_GIGASET_DEBUG
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if (unlikely(!(inputstate & INS_have_data))) {
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gig_dbg(DEBUG_HDLC, "7e (%d x) ================",
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bcs->emptycount);
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bcs->emptycount = 0;
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}
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#endif
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inputstate |= INS_have_data;
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if (likely(!(inputstate & INS_skip_frame))) {
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if (unlikely(skb->len == SBUFSIZE)) {
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dev_warn(cs->dev, "received packet too long\n");
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dev_kfree_skb_any(skb);
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skb = NULL;
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inputstate |= INS_skip_frame;
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break;
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}
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*__skb_put(skb, 1) = c;
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fcs = crc_ccitt_byte(fcs, c);
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}
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if (unlikely(!numbytes))
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break;
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c = *src++;
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--numbytes;
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if (unlikely(c == DLE_FLAG &&
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(cs->dle ||
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inbuf->inputstate & INS_DLE_command))) {
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inbuf->inputstate |= INS_DLE_char;
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break;
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}
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}
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bcs->inputstate = inputstate;
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bcs->fcs = fcs;
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bcs->skb = skb;
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return startbytes - numbytes;
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}
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/* process a block of received bytes in transparent data mode
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* Invert bytes, undoing byte stuffing and watching for DLE escapes.
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* If DLE is encountered, return immediately to let the caller handle it.
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* Return value:
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* number of processed bytes
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* numbytes (all bytes processed) on error --FIXME
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*/
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static inline int iraw_loop(unsigned char c, unsigned char *src, int numbytes,
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struct inbuf_t *inbuf)
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{
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struct cardstate *cs = inbuf->cs;
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struct bc_state *bcs = inbuf->bcs;
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int inputstate = bcs->inputstate;
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struct sk_buff *skb = bcs->skb;
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int startbytes = numbytes;
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for (;;) {
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/* add character */
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inputstate |= INS_have_data;
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if (likely(!(inputstate & INS_skip_frame))) {
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if (unlikely(skb->len == SBUFSIZE)) {
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//FIXME just pass skb up and allocate a new one
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dev_warn(cs->dev, "received packet too long\n");
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dev_kfree_skb_any(skb);
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skb = NULL;
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inputstate |= INS_skip_frame;
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break;
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}
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*__skb_put(skb, 1) = bitrev8(c);
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}
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if (unlikely(!numbytes))
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break;
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c = *src++;
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--numbytes;
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if (unlikely(c == DLE_FLAG &&
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(cs->dle ||
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inbuf->inputstate & INS_DLE_command))) {
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inbuf->inputstate |= INS_DLE_char;
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break;
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}
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}
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/* pass data up */
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if (likely(inputstate & INS_have_data)) {
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if (likely(!(inputstate & INS_skip_frame))) {
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gigaset_rcv_skb(skb, cs, bcs);
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}
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inputstate &= ~(INS_have_data | INS_skip_frame);
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if (unlikely(bcs->ignore)) {
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inputstate |= INS_skip_frame;
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skb = NULL;
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} else if (likely((skb = dev_alloc_skb(SBUFSIZE + HW_HDR_LEN))
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!= NULL)) {
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skb_reserve(skb, HW_HDR_LEN);
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} else {
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dev_warn(cs->dev, "could not allocate new skb\n");
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inputstate |= INS_skip_frame;
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}
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}
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bcs->inputstate = inputstate;
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bcs->skb = skb;
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return startbytes - numbytes;
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}
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/* process a block of data received from the device
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*/
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void gigaset_m10x_input(struct inbuf_t *inbuf)
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{
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struct cardstate *cs;
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unsigned tail, head, numbytes;
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unsigned char *src, c;
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int procbytes;
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head = atomic_read(&inbuf->head);
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tail = atomic_read(&inbuf->tail);
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gig_dbg(DEBUG_INTR, "buffer state: %u -> %u", head, tail);
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if (head != tail) {
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cs = inbuf->cs;
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src = inbuf->data + head;
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numbytes = (head > tail ? RBUFSIZE : tail) - head;
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gig_dbg(DEBUG_INTR, "processing %u bytes", numbytes);
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while (numbytes) {
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if (atomic_read(&cs->mstate) == MS_LOCKED) {
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procbytes = lock_loop(src, numbytes, inbuf);
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src += procbytes;
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numbytes -= procbytes;
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} else {
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c = *src++;
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--numbytes;
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if (c == DLE_FLAG && (cs->dle ||
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inbuf->inputstate & INS_DLE_command)) {
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if (!(inbuf->inputstate & INS_DLE_char)) {
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inbuf->inputstate |= INS_DLE_char;
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goto nextbyte;
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}
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/* <DLE> <DLE> => <DLE> in data stream */
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inbuf->inputstate &= ~INS_DLE_char;
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}
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if (!(inbuf->inputstate & INS_DLE_char)) {
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/* FIXME use function pointers? */
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if (inbuf->inputstate & INS_command)
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procbytes = cmd_loop(c, src, numbytes, inbuf);
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else if (inbuf->bcs->proto2 == ISDN_PROTO_L2_HDLC)
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procbytes = hdlc_loop(c, src, numbytes, inbuf);
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else
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procbytes = iraw_loop(c, src, numbytes, inbuf);
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src += procbytes;
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numbytes -= procbytes;
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} else { /* DLE char */
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inbuf->inputstate &= ~INS_DLE_char;
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switch (c) {
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case 'X': /*begin of command*/
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#ifdef CONFIG_GIGASET_DEBUG
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if (inbuf->inputstate & INS_command)
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dev_err(cs->dev,
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"received <DLE> 'X' in command mode\n");
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#endif
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inbuf->inputstate |=
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INS_command | INS_DLE_command;
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break;
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case '.': /*end of command*/
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#ifdef CONFIG_GIGASET_DEBUG
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if (!(inbuf->inputstate & INS_command))
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dev_err(cs->dev,
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"received <DLE> '.' in hdlc mode\n");
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#endif
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inbuf->inputstate &= cs->dle ?
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~(INS_DLE_command|INS_command)
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: ~INS_DLE_command;
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break;
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//case DLE_FLAG: /*DLE_FLAG in data stream*/ /* schon oben behandelt! */
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default:
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dev_err(cs->dev,
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"received 0x10 0x%02x!\n",
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(int) c);
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/* FIXME: reset driver?? */
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}
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}
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}
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nextbyte:
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if (!numbytes) {
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/* end of buffer, check for wrap */
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if (head > tail) {
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head = 0;
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src = inbuf->data;
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numbytes = tail;
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} else {
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head = tail;
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break;
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}
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}
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}
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gig_dbg(DEBUG_INTR, "setting head to %u", head);
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atomic_set(&inbuf->head, head);
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}
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}
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EXPORT_SYMBOL_GPL(gigaset_m10x_input);
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/* == data output ========================================================== */
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/* Encoding of a PPP packet into an octet stuffed HDLC frame
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* with FCS, opening and closing flags.
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* parameters:
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* skb skb containing original packet (freed upon return)
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* head number of headroom bytes to allocate in result skb
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* tail number of tailroom bytes to allocate in result skb
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* Return value:
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* pointer to newly allocated skb containing the result frame
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*/
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static struct sk_buff *HDLC_Encode(struct sk_buff *skb, int head, int tail)
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{
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struct sk_buff *hdlc_skb;
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__u16 fcs;
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unsigned char c;
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unsigned char *cp;
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int len;
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unsigned int stuf_cnt;
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stuf_cnt = 0;
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fcs = PPP_INITFCS;
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cp = skb->data;
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len = skb->len;
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while (len--) {
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if (muststuff(*cp))
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stuf_cnt++;
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fcs = crc_ccitt_byte(fcs, *cp++);
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}
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fcs ^= 0xffff; /* complement */
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/* size of new buffer: original size + number of stuffing bytes
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* + 2 bytes FCS + 2 stuffing bytes for FCS (if needed) + 2 flag bytes
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*/
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hdlc_skb = dev_alloc_skb(skb->len + stuf_cnt + 6 + tail + head);
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if (!hdlc_skb) {
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dev_kfree_skb(skb);
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return NULL;
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}
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skb_reserve(hdlc_skb, head);
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/* Copy acknowledge request into new skb */
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memcpy(hdlc_skb->head, skb->head, 2);
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/* Add flag sequence in front of everything.. */
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*(skb_put(hdlc_skb, 1)) = PPP_FLAG;
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/* Perform byte stuffing while copying data. */
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while (skb->len--) {
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if (muststuff(*skb->data)) {
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*(skb_put(hdlc_skb, 1)) = PPP_ESCAPE;
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*(skb_put(hdlc_skb, 1)) = (*skb->data++) ^ PPP_TRANS;
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} else
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*(skb_put(hdlc_skb, 1)) = *skb->data++;
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}
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/* Finally add FCS (byte stuffed) and flag sequence */
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c = (fcs & 0x00ff); /* least significant byte first */
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if (muststuff(c)) {
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*(skb_put(hdlc_skb, 1)) = PPP_ESCAPE;
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c ^= PPP_TRANS;
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}
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*(skb_put(hdlc_skb, 1)) = c;
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c = ((fcs >> 8) & 0x00ff);
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if (muststuff(c)) {
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*(skb_put(hdlc_skb, 1)) = PPP_ESCAPE;
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c ^= PPP_TRANS;
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}
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*(skb_put(hdlc_skb, 1)) = c;
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*(skb_put(hdlc_skb, 1)) = PPP_FLAG;
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dev_kfree_skb(skb);
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return hdlc_skb;
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}
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/* Encoding of a raw packet into an octet stuffed bit inverted frame
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* parameters:
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* skb skb containing original packet (freed upon return)
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* head number of headroom bytes to allocate in result skb
|
|
* tail number of tailroom bytes to allocate in result skb
|
|
* Return value:
|
|
* pointer to newly allocated skb containing the result frame
|
|
*/
|
|
static struct sk_buff *iraw_encode(struct sk_buff *skb, int head, int tail)
|
|
{
|
|
struct sk_buff *iraw_skb;
|
|
unsigned char c;
|
|
unsigned char *cp;
|
|
int len;
|
|
|
|
/* worst case: every byte must be stuffed */
|
|
iraw_skb = dev_alloc_skb(2*skb->len + tail + head);
|
|
if (!iraw_skb) {
|
|
dev_kfree_skb(skb);
|
|
return NULL;
|
|
}
|
|
skb_reserve(iraw_skb, head);
|
|
|
|
cp = skb->data;
|
|
len = skb->len;
|
|
while (len--) {
|
|
c = bitrev8(*cp++);
|
|
if (c == DLE_FLAG)
|
|
*(skb_put(iraw_skb, 1)) = c;
|
|
*(skb_put(iraw_skb, 1)) = c;
|
|
}
|
|
dev_kfree_skb(skb);
|
|
return iraw_skb;
|
|
}
|
|
|
|
/* gigaset_send_skb
|
|
* called by common.c to queue an skb for sending
|
|
* and start transmission if necessary
|
|
* parameters:
|
|
* B Channel control structure
|
|
* skb
|
|
* Return value:
|
|
* number of bytes accepted for sending
|
|
* (skb->len if ok, 0 if out of buffer space)
|
|
* or error code (< 0, eg. -EINVAL)
|
|
*/
|
|
int gigaset_m10x_send_skb(struct bc_state *bcs, struct sk_buff *skb)
|
|
{
|
|
unsigned len = skb->len;
|
|
unsigned long flags;
|
|
|
|
if (bcs->proto2 == ISDN_PROTO_L2_HDLC)
|
|
skb = HDLC_Encode(skb, HW_HDR_LEN, 0);
|
|
else
|
|
skb = iraw_encode(skb, HW_HDR_LEN, 0);
|
|
if (!skb) {
|
|
err("unable to allocate memory for encoding!\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
skb_queue_tail(&bcs->squeue, skb);
|
|
spin_lock_irqsave(&bcs->cs->lock, flags);
|
|
if (bcs->cs->connected)
|
|
tasklet_schedule(&bcs->cs->write_tasklet);
|
|
spin_unlock_irqrestore(&bcs->cs->lock, flags);
|
|
|
|
return len; /* ok so far */
|
|
}
|
|
EXPORT_SYMBOL_GPL(gigaset_m10x_send_skb);
|