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Diffstat (limited to 'libwmc/src/utils.c')
| -rw-r--r-- | libwmc/src/utils.c | 459 |
1 files changed, 0 insertions, 459 deletions
diff --git a/libwmc/src/utils.c b/libwmc/src/utils.c deleted file mode 100644 index 5539edaf..00000000 --- a/libwmc/src/utils.c +++ /dev/null @@ -1,459 +0,0 @@ -/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ -/* - * Copyright (C) 2010 Red Hat, Inc. - * - * This program is free software: you can redistribute it and/or - * modify it under the terms of version 2 of the GNU General Public - * License 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, see <http://www.gnu.org/licenses/>. - */ - -#include <stdio.h> -#include <sys/types.h> -#include <unistd.h> -#include <malloc.h> -#include <fcntl.h> -#include <string.h> - -#include "utils.h" -#include "errors.h" - -/* QCDM protocol frames are pseudo Async HDLC frames which end with a 3-byte - * trailer. This trailer consists of the 16-bit CRC of the frame plus an ending - * "async control character" whose value is 0x7E. The frame *and* the CRC are - * escaped before adding the trailing control character so that the control - * character (0x7E) and the escape marker (0x7D) are never seen in the frame. - */ - -/* Table of CRCs for each possible byte, with a generator polynomial of 0x8408 */ -static const uint16_t crc_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 -}; - -/* Calculate the CRC for a buffer using a seed of 0xffff */ -uint16_t -wmc_crc16 (const char *buffer, size_t len, uint16_t seed) -{ - uint16_t crc = seed ? seed : 0xFFFF; - - while (len--) - crc = crc_table[(crc ^ *buffer++) & 0xff] ^ (crc >> 8); - return ~crc; -} - -#define DIAG_ESC_CHAR 0x7D /* Escape sequence 1st character value */ -#define DIAG_ESC_MASK 0x20 /* Escape sequence complement value */ - -/* Performs DM escaping on inbuf putting the result into outbuf, and returns - * the final length of the buffer. - */ -size_t -hdlc_escape (const char *inbuf, - size_t inbuf_len, - wmcbool escape_all_ctrl, - char *outbuf, - size_t outbuf_len) -{ - const char *src = inbuf; - char *dst = outbuf; - size_t i = inbuf_len; - - wmc_return_val_if_fail (inbuf != NULL, 0); - wmc_return_val_if_fail (inbuf_len > 0, 0); - wmc_return_val_if_fail (outbuf != NULL, 0); - wmc_return_val_if_fail (outbuf_len > inbuf_len, 0); - - /* Since escaping potentially doubles the # of bytes, short-circuit the - * length check if destination buffer is clearly large enough. Note the - * - */ - if (outbuf_len <= inbuf_len << 1) { - size_t outbuf_required = inbuf_len + 1; /* +1 for the trailing control char */ - - /* Each escaped character takes up two bytes in the output buffer */ - while (i--) { - if ( *src == DIAG_CONTROL_CHAR - || *src == DIAG_ESC_CHAR - || (escape_all_ctrl && *src <= 0x20)) - outbuf_required++; - src++; - } - - if (outbuf_len < outbuf_required) - return 0; - } - - /* Do the actual escaping. Replace both the control character and - * the escape character in the source buffer with the following sequence: - * - * <escape_char> <src_byte ^ escape_mask> - */ - src = inbuf; - i = inbuf_len; - while (i--) { - uint8_t byte = (uint8_t) *src++; - - if ( byte == DIAG_CONTROL_CHAR - || byte == DIAG_ESC_CHAR - || (escape_all_ctrl && byte <= 0x20)) { - *dst++ = DIAG_ESC_CHAR; - *dst++ = byte ^ DIAG_ESC_MASK; - } else - *dst++ = byte; - } - - return (dst - outbuf); -} - -size_t -hdlc_unescape (const char *inbuf, - size_t inbuf_len, - char *outbuf, - size_t outbuf_len, - wmcbool *escaping) -{ - size_t i, outsize; - - wmc_return_val_if_fail (inbuf_len > 0, 0); - wmc_return_val_if_fail (outbuf_len >= inbuf_len, 0); - wmc_return_val_if_fail (escaping != NULL, 0); - - for (i = 0, outsize = 0; i < inbuf_len; i++) { - if (*escaping) { - outbuf[outsize++] = inbuf[i] ^ DIAG_ESC_MASK; - *escaping = FALSE; - } else if (inbuf[i] == DIAG_ESC_CHAR) - *escaping = TRUE; - else - outbuf[outsize++] = inbuf[i]; - - /* About to overrun output buffer size */ - if (outsize >= outbuf_len) - return 0; - } - - return outsize; -} - -/** - * hdlc_encapsulate_buffer: - * @inbuf: data buffer to encapsulate - * @cmd_len: size of the data contained in @inbuf - * @inbuf_len: total size of @inbuf itself (not just the data) - * @crc_seed: if non-zero, CRC-16 seed to use; if 0, uses standard 0xFFFF - * @add_trailer: if %TRUE, adds trailing 0x7E - * @escape_all_ctrl: if %TRUE, escapes all control characters instead of only - * special HDLC escape characters 0x7D and 0x7E - * @outbuf: buffer in which to put the encapsulated data - * @outbuf_len: total size of @outbuf - * - * Escapes and CRCs given data using HDLC-style mechanisms, and optionally adds - * the trailing control character that denotes the end of the HDLC frame. - * - * Returns: size of the encapsulated data writted to @outbuf. - **/ -size_t -hdlc_encapsulate_buffer (char *inbuf, - size_t cmd_len, - size_t inbuf_len, - uint16_t crc_seed, - wmcbool add_trailer, - wmcbool escape_all_ctrl, - char *outbuf, - size_t outbuf_len) -{ - uint16_t crc; - size_t escaped_len; - - wmc_return_val_if_fail (inbuf != NULL, 0); - wmc_return_val_if_fail (cmd_len >= 1, 0); - wmc_return_val_if_fail (inbuf_len >= cmd_len + 2, 0); /* space for CRC */ - wmc_return_val_if_fail (outbuf != NULL, 0); - - /* Add the CRC */ - crc = wmc_crc16 (inbuf, cmd_len, crc_seed ? crc_seed : 0xFFFF); - inbuf[cmd_len++] = crc & 0xFF; - inbuf[cmd_len++] = (crc >> 8) & 0xFF; - - escaped_len = hdlc_escape (inbuf, cmd_len, escape_all_ctrl, outbuf, outbuf_len); - wmc_return_val_if_fail (outbuf_len > escaped_len, 0); - - if (add_trailer) - outbuf[escaped_len++] = DIAG_CONTROL_CHAR; - - return escaped_len; -} - -#define AT_WMC_PREFIX "AT*WMC=" - -/** - * uml290_wmc_encapsulate: - * @inbuf: data buffer to encapsulate - * @cmd_len: size of the data contained in @inbuf - * @inbuf_len: total size of @inbuf itself (not just the data) - * @outbuf: buffer in which to put the encapsulated data - * @outbuf_len: total size of @outbuf - * - * Escapes and CRCs given data using HDLC-style mechanisms with UML290 specific - * quirks. - * - * Returns: size of the encapsulated data writted to @outbuf. - */ -static size_t -uml290_wmc_encapsulate (char *inbuf, - size_t cmd_len, - size_t inbuf_len, - char *outbuf, - size_t outbuf_len) -{ - size_t encap_len; - size_t estimated_out_len; - - wmc_return_val_if_fail (inbuf != NULL, 0); - wmc_return_val_if_fail (cmd_len >= 1, 0); - wmc_return_val_if_fail (inbuf_len >= cmd_len + 2, 0); /* space for CRC */ - wmc_return_val_if_fail (outbuf != NULL, 0); - - estimated_out_len = cmd_len + strlen (AT_WMC_PREFIX); - estimated_out_len += 3; /* CRC + trailer */ - estimated_out_len += cmd_len * 2; /* escaping */ - wmc_return_val_if_fail (outbuf_len > estimated_out_len, 0); - - memcpy (outbuf, AT_WMC_PREFIX, strlen (AT_WMC_PREFIX)); - - encap_len = hdlc_encapsulate_buffer (inbuf, cmd_len, inbuf_len, 0xAAFE, - FALSE, TRUE, - outbuf + strlen (AT_WMC_PREFIX), - outbuf_len); - if (encap_len > 0) { - encap_len += strlen (AT_WMC_PREFIX); - outbuf[encap_len++] = 0x0D; /* trailer */ - } - - return encap_len; -} - -/** - * wmc_encapsulate: - * @inbuf: data buffer to encapsulate - * @cmd_len: size of the data contained in @inbuf - * @inbuf_len: total size of @inbuf itself (not just the data) - * @outbuf: buffer in which to put the encapsulated data - * @outbuf_len: total size of @outbuf - * @uml290: if %TRUE return buffer suitable for sending to UML290 devices - * - * Escapes and CRCs given data using HDLC-style mechanisms. - * - * Returns: size of the encapsulated data writted to @outbuf. - */ -size_t -wmc_encapsulate (char *inbuf, - size_t cmd_len, - size_t inbuf_len, - char *outbuf, - size_t outbuf_len, - wmcbool uml290) -{ - wmc_return_val_if_fail (inbuf != NULL, 0); - wmc_return_val_if_fail (cmd_len >= 1, 0); - wmc_return_val_if_fail (inbuf_len >= cmd_len + 3, 0); /* space for CRC + trailer */ - wmc_return_val_if_fail (outbuf != NULL, 0); - - if (uml290) - return uml290_wmc_encapsulate (inbuf, cmd_len, inbuf_len, outbuf, outbuf_len); - - /* Otherwise do normal WMC */ - return hdlc_encapsulate_buffer (inbuf, cmd_len, inbuf_len, - 0, TRUE, FALSE, outbuf, outbuf_len); -} - -/** - * hdlc_decapsulate_buffer: - * @inbuf: buffer in which to look for an HDLC frame - * @inbuf_len: length of valid data in @inbuf - * @check_known_crc: if %TRUE, validate the CRC using @known_crc if the normal - * CRC check fails - * @known_crc: if @check_known_crc is %TRUE, compare the frame's CRC against - * @known_crc if the normal CRC check fails. @known_crc must be in Little - * Endian (LE) byte order. - * @outbuf: buffer in which to put decapsulated data from the HDLC frame - * @outbuf_len: max size of @outbuf - * @out_decap_len: on success, size of the decapsulated data - * @out_used: on either success or failure, amount of data used; caller should - * discard this much data from @inbuf before the next call to this function - * @out_need_more: when TRUE, indicates that more data is required before - * a determination about a valid HDLC frame can be made; caller should add - * more data to @inbuf before calling this function again. - * - * Attempts to retrieve, unescape, and CRC-check an HDLC frame from the given - * buffer. - * - * Returns: FALSE on error (packet was invalid or malformed, or the CRC check - * failed, etc) and places number of bytes to discard from @inbuf in @out_used. - * When TRUE, either more data is required (in which case @out_need_more will - * be TRUE), or a data packet was successfully retrieved from @inbuf and the - * decapsulated packet of length @out_decap_len was placed into @outbuf. In - * all cases the caller should advance the buffer by the number of bytes - * returned in @out_used before calling this function again. - **/ -wmcbool -hdlc_decapsulate_buffer (const char *inbuf, - size_t inbuf_len, - wmcbool check_known_crc, - uint16_t known_crc, - char *outbuf, - size_t outbuf_len, - size_t *out_decap_len, - size_t *out_used, - wmcbool *out_need_more) -{ - wmcbool escaping = FALSE; - size_t i, pkt_len = 0, unesc_len; - uint16_t crc, pkt_crc; - - wmc_return_val_if_fail (inbuf != NULL, FALSE); - wmc_return_val_if_fail (outbuf != NULL, FALSE); - wmc_return_val_if_fail (outbuf_len > 0, FALSE); - wmc_return_val_if_fail (out_decap_len != NULL, FALSE); - wmc_return_val_if_fail (out_used != NULL, FALSE); - wmc_return_val_if_fail (out_need_more != NULL, FALSE); - - *out_decap_len = 0; - *out_used = 0; - *out_need_more = FALSE; - - if (inbuf_len < 4) { - *out_need_more = TRUE; - return TRUE; - } - - /* Find the async control character */ - for (i = 0; i < inbuf_len; i++) { - if (inbuf[i] == DIAG_CONTROL_CHAR) { - /* If the control character shows up in a position before a valid - * QCDM packet length (4), the packet is malformed. - */ - if (i < 3) { - /* Tell the caller to advance the buffer past the control char */ - *out_used = i + 1; - return FALSE; - } - - pkt_len = i; - break; - } - } - - /* No control char yet, need more data */ - if (!pkt_len) { - *out_need_more = TRUE; - return TRUE; - } - - /* Unescape first; note that pkt_len */ - unesc_len = hdlc_unescape (inbuf, pkt_len, outbuf, outbuf_len, &escaping); - if (!unesc_len) { - /* Tell the caller to advance the buffer past the control char */ - *out_used = pkt_len + 1; - return FALSE; - } - - if (escaping) { - *out_need_more = TRUE; - return TRUE; - } - - /* Check the CRC of the packet's data */ - crc = wmc_crc16 (outbuf, unesc_len - 2, 0); - pkt_crc = outbuf[unesc_len - 2] & 0xFF; - pkt_crc |= (outbuf[unesc_len - 1] & 0xFF) << 8; - if (crc != pkt_crc) { - if (!check_known_crc || (pkt_crc != known_crc)) { - *out_used = pkt_len + 1; /* packet + CRC + 0x7E */ - return FALSE; - } - } - - *out_used = pkt_len + 1; /* packet + CRC + 0x7E */ - *out_decap_len = unesc_len - 2; /* decap_len should not include the CRC */ - return TRUE; -} - -/** - * wmc_decapsulate: - * @inbuf: buffer in which to look for an HDLC frame - * @inbuf_len: length of valid data in @inbuf - * @outbuf: buffer in which to put decapsulated data from the HDLC frame - * @outbuf_len: max size of @outbuf - * @out_decap_len: on success, size of the decapsulated data - * @out_used: on either success or failure, amount of data used; caller should - * discard this much data from @inbuf before the next call to this function - * @out_need_more: when TRUE, indicates that more data is required before - * a determination about a valid HDLC frame can be made; caller should add - * more data to @inbuf before calling this function again. - * @uml290: if %TRUE decapsulate response from UML290 devices - * - * Attempts to retrieve, unescape, and CRC-check an HDLC frame from the given - * buffer. - * - * Returns: FALSE on error (packet was invalid or malformed, or the CRC check - * failed, etc) and places number of bytes to discard from @inbuf in @out_used. - * When TRUE, either more data is required (in which case @out_need_more will - * be TRUE), or a data packet was successfully retrieved from @inbuf and the - * decapsulated packet of length @out_decap_len was placed into @outbuf. In - * all cases the caller should advance the buffer by the number of bytes - * returned in @out_used before calling this function again. - **/ -wmcbool -wmc_decapsulate (const char *inbuf, - size_t inbuf_len, - char *outbuf, - size_t outbuf_len, - size_t *out_decap_len, - size_t *out_used, - wmcbool *out_need_more, - wmcbool uml290) -{ - return hdlc_decapsulate_buffer (inbuf, inbuf_len, - uml290, uml290 ? 0x3030 : 0, - outbuf, outbuf_len, - out_decap_len, out_used, out_need_more); -} |