diff --git a/Makefile.am b/Makefile.am index ee10095b..dee4dc77 100644 --- a/Makefile.am +++ b/Makefile.am @@ -50,6 +50,7 @@ gatchat_sources = gatchat/gatchat.h gatchat/gatchat.c \ gatchat/gatresult.h gatchat/gatresult.c \ gatchat/gatsyntax.h gatchat/gatsyntax.c \ gatchat/ringbuffer.h gatchat/ringbuffer.c \ + gatchat/crc-ccitt.h gatchat/crc-ccitt.c \ gatchat/gatmux.h gatchat/gatmux.c \ gatchat/gsm0710.h gatchat/gsm0710.c \ gatchat/gattty.h gatchat/gattty.c \ diff --git a/gatchat/crc-ccitt.c b/gatchat/crc-ccitt.c new file mode 100644 index 00000000..3275572e --- /dev/null +++ b/gatchat/crc-ccitt.c @@ -0,0 +1,61 @@ +/* + * + * AT chat library with GLib integration + * + * Copyright (C) 2008-2010 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + */ + +#ifdef HAVE_CONFIG_H +#include +#endif + +#include "crc-ccitt.h" + +const guint16 crc_ccitt_table[256] = { + 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf, + 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7, + 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e, + 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876, + 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd, + 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5, + 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c, + 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974, + 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb, + 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3, + 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a, + 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72, + 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9, + 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1, + 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738, + 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70, + 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7, + 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff, + 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036, + 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e, + 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5, + 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd, + 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134, + 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c, + 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3, + 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb, + 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232, + 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a, + 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1, + 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9, + 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330, + 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78 +}; diff --git a/gatchat/crc-ccitt.h b/gatchat/crc-ccitt.h new file mode 100644 index 00000000..60d20729 --- /dev/null +++ b/gatchat/crc-ccitt.h @@ -0,0 +1,33 @@ +/* + * + * AT chat library with GLib integration + * + * Copyright (C) 2008-2010 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + */ + +#ifdef HAVE_CONFIG_H +#include +#endif + +#include + +extern guint16 const crc_ccitt_table[256]; + +static inline guint16 crc_ccitt_byte(guint16 crc, const guint8 c) +{ + return (crc >> 8) ^ crc_ccitt_table[(crc ^ c) & 0xff]; +} diff --git a/gatchat/gatppp.c b/gatchat/gatppp.c index cac0f1aa..b98ab14d 100644 --- a/gatchat/gatppp.c +++ b/gatchat/gatppp.c @@ -36,6 +36,7 @@ #include "gatutil.h" #include "gatppp.h" +#include "crc-ccitt.h" #include "ppp.h" #define DEFAULT_MRU 1500 @@ -111,62 +112,6 @@ struct frame_buffer { guint8 bytes[0]; }; -/* - * FCS lookup table copied from rfc1662. - */ -static guint16 fcstab[256] = { - 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf, - 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7, - 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e, - 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876, - 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd, - 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5, - 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c, - 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974, - 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb, - 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3, - 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a, - 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72, - 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9, - 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1, - 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738, - 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70, - 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7, - 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff, - 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036, - 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e, - 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5, - 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd, - 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134, - 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c, - 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3, - 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb, - 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232, - 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a, - 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1, - 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9, - 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330, - 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78 -}; - -/* - * Calculate a new fcs given the current fcs and the new data. - * copied from rfc1662 - * - * The FCS field is calculated over all bits of the Address, Control, - * Protocol, Information and Padding fields, not including any start - * and stop bits (asynchronous) nor any bits (synchronous) or octets - * (asynchronous or synchronous) inserted for transparency. This - * also does not include the Flag Sequences nor the FCS field itself. - */ -static guint16 ppp_fcs(guint16 fcs, guint8 c) -{ - guint16 new_fcs; - - new_fcs = (fcs >> 8) ^ fcstab[(fcs ^ c) & 0xff]; - return new_fcs; -} - /* * escape any chars less than 0x20, and check the transmit accm table to * see if this character should be escaped. @@ -212,9 +157,9 @@ static struct frame_buffer *ppp_encode(GAtPPP *ppp, guint8 *data, int len) frame[pos++] = PPP_FLAG_SEQ; /* from here till end flag, calculate FCS over each character */ - fcs = ppp_fcs(fcs, PPP_ADDR_FIELD); + fcs = crc_ccitt_byte(fcs, PPP_ADDR_FIELD); ppp_put(ppp, frame, &pos, PPP_ADDR_FIELD, lcp); - fcs = ppp_fcs(fcs, PPP_CTRL); + fcs = crc_ccitt_byte(fcs, PPP_CTRL); ppp_put(ppp, frame, &pos, PPP_CTRL, lcp); /* @@ -222,7 +167,7 @@ static struct frame_buffer *ppp_encode(GAtPPP *ppp, guint8 *data, int len) * neccessary */ while (len--) { - fcs = ppp_fcs(fcs, data[i]); + fcs = crc_ccitt_byte(fcs, data[i]); ppp_put(ppp, frame, &pos, data[i++], lcp); } @@ -303,7 +248,7 @@ static struct frame_buffer *ppp_decode(GAtPPP *ppp, guint8 *frame) } else data[i] = frame[pos]; - fcs = ppp_fcs(fcs, data[i]); + fcs = crc_ccitt_byte(fcs, data[i]); i++; pos++; }