lib.c

/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-3-Clause) */
/*
 * lib.c - library for command line tools
 *
 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Volkswagen nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * Alternatively, provided that this notice is retained in full, this
 * software may be distributed under the terms of the GNU General
 * Public License ("GPL") version 2, in which case the provisions of the
 * GPL apply INSTEAD OF those given above.
 *
 * The provided data structures and external interfaces from this code
 * are not restricted to be used by modules with a GPL compatible license.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * Send feedback to <linux-can@vger.kernel.org>
 *
 */

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <time.h>

#include <linux/can.h>
#include <linux/can/error.h>
#include <sys/socket.h> /* for sa_family_t */

#include "lib.h"

#define CANID_DELIM '#'
#define CC_DLC_DELIM '_'
#define XL_HDR_DELIM ':'
#define DATA_SEPERATOR '.'

const char hex_asc_upper[] = "0123456789ABCDEF";

#define hex_asc_upper_lo(x) hex_asc_upper[((x)&0x0F)]
#define hex_asc_upper_hi(x) hex_asc_upper[((x)&0xF0) >> 4]

static inline void put_hex_byte(char *buf, __u8 byte)
{
	buf[0] = hex_asc_upper_hi(byte);
	buf[1] = hex_asc_upper_lo(byte);
}

static inline void _put_id(char *buf, int end_offset, canid_t id)
{
	/* build 3 (SFF) or 8 (EFF) digit CAN identifier */
	while (end_offset >= 0) {
		buf[end_offset--] = hex_asc_upper_lo(id);
		id >>= 4;
	}
}

#define put_sff_id(buf, id) _put_id(buf, 2, id)
#define put_eff_id(buf, id) _put_id(buf, 7, id)

/* CAN DLC to real data length conversion helpers */

static const unsigned char dlc2len[] = {0, 1, 2, 3, 4, 5, 6, 7,
					8, 12, 16, 20, 24, 32, 48, 64};

/* get data length from raw data length code (DLC) */
unsigned char can_fd_dlc2len(unsigned char dlc)
{
	return dlc2len[dlc & 0x0F];
}

static const unsigned char len2dlc[] = {0, 1, 2, 3, 4, 5, 6, 7, 8,		/* 0 - 8 */
					9, 9, 9, 9,				/* 9 - 12 */
					10, 10, 10, 10,				/* 13 - 16 */
					11, 11, 11, 11,				/* 17 - 20 */
					12, 12, 12, 12,				/* 21 - 24 */
					13, 13, 13, 13, 13, 13, 13, 13,		/* 25 - 32 */
					14, 14, 14, 14, 14, 14, 14, 14,		/* 33 - 40 */
					14, 14, 14, 14, 14, 14, 14, 14,		/* 41 - 48 */
					15, 15, 15, 15, 15, 15, 15, 15,		/* 49 - 56 */
					15, 15, 15, 15, 15, 15, 15, 15};	/* 57 - 64 */

/* map the sanitized data length to an appropriate data length code */
unsigned char can_fd_len2dlc(unsigned char len)
{
	if (len > 64)
		return 0xF;

	return len2dlc[len];
}

unsigned char asc2nibble(char c)
{
	if ((c >= '0') && (c <= '9'))
		return c - '0';

	if ((c >= 'A') && (c <= 'F'))
		return c - 'A' + 10;

	if ((c >= 'a') && (c <= 'f'))
		return c - 'a' + 10;

	return 16; /* error */
}

int hexstring2data(char *arg, unsigned char *data, int maxdlen)
{
	int len = strlen(arg);
	int i;
	unsigned char tmp;

	if (!len || len % 2 || len > maxdlen * 2)
		return 1;

	memset(data, 0, maxdlen);

	for (i = 0; i < len / 2; i++) {
		tmp = asc2nibble(*(arg + (2 * i)));
		if (tmp > 0x0F)
			return 1;

		data[i] = (tmp << 4);

		tmp = asc2nibble(*(arg + (2 * i) + 1));
		if (tmp > 0x0F)
			return 1;

		data[i] |= tmp;
	}

	return 0;
}

int parse_canframe(char *cs, cu_t *cu)
{
	/* documentation see lib.h */

	int i, idx, dlen, len;
	int maxdlen = CAN_MAX_DLEN;
	int mtu = CAN_MTU;
	__u8 *data = cu->fd.data; /* fill CAN CC/FD data by default */
	canid_t tmp;

	len = strlen(cs);
	//printf("'%s' len %d\n", cs, len);

	memset(cu, 0, sizeof(*cu)); /* init CAN CC/FD/XL frame, e.g. LEN = 0 */

	if (len < 4)
		return 0;

	if (cs[3] == CANID_DELIM) { /* 3 digits SFF */

		idx = 4;
		for (i = 0; i < 3; i++) {
			if ((tmp = asc2nibble(cs[i])) > 0x0F)
				return 0;
			cu->cc.can_id |= tmp << (2 - i) * 4;
		}

	} else if (cs[5] == CANID_DELIM) { /* 5 digits CAN XL VCID/PRIO*/

		idx = 6;
		for (i = 0; i < 5; i++) {
			if ((tmp = asc2nibble(cs[i])) > 0x0F)
				return 0;
			cu->xl.prio |= tmp << (4 - i) * 4;
		}

		/* the VCID starts at bit position 16 */
		tmp = (cu->xl.prio << 4) & CANXL_VCID_MASK;
		cu->xl.prio &= CANXL_PRIO_MASK;
		cu->xl.prio |= tmp;

	} else if (cs[8] == CANID_DELIM) { /* 8 digits EFF */

		idx = 9;
		for (i = 0; i < 8; i++) {
			if ((tmp = asc2nibble(cs[i])) > 0x0F)
				return 0;
			cu->cc.can_id |= tmp << (7 - i) * 4;
		}
		if (!(cu->cc.can_id & CAN_ERR_FLAG)) /* 8 digits but no errorframe?  */
			cu->cc.can_id |= CAN_EFF_FLAG;   /* then it is an extended frame */

	} else
		return 0;

	if ((cs[idx] == 'R') || (cs[idx] == 'r')) { /* RTR frame */
		cu->cc.can_id |= CAN_RTR_FLAG;

		/* check for optional DLC value for CAN 2.0B frames */
		if (cs[++idx] && (tmp = asc2nibble(cs[idx++])) <= CAN_MAX_DLEN) {
			cu->cc.len = tmp;

			/* check for optional raw DLC value for CAN 2.0B frames */
			if ((tmp == CAN_MAX_DLEN) && (cs[idx++] == CC_DLC_DELIM)) {
				tmp = asc2nibble(cs[idx]);
				if ((tmp > CAN_MAX_DLEN) && (tmp <= CAN_MAX_RAW_DLC))
					cu->cc.len8_dlc = tmp;
			}
		}
		return mtu;
	}

	if (cs[idx] == CANID_DELIM) { /* CAN FD frame escape char '##' */
		maxdlen = CANFD_MAX_DLEN;
		mtu = CANFD_MTU;

		/* CAN FD frame <canid>##<flags><data>* */
		if ((tmp = asc2nibble(cs[idx + 1])) > 0x0F)
			return 0;

		cu->fd.flags = tmp;
		cu->fd.flags |= CANFD_FDF; /* dual-use */
		idx += 2;

	} else if (cs[idx + 14] == CANID_DELIM) { /* CAN XL frame '#80:00:11223344#' */
		maxdlen = CANXL_MAX_DLEN;
		mtu = CANXL_MTU;
		data = cu->xl.data; /* fill CAN XL data */

		if ((cs[idx + 2] != XL_HDR_DELIM) || (cs[idx + 5] != XL_HDR_DELIM))
			return 0;

		if ((tmp = asc2nibble(cs[idx++])) > 0x0F)
			return 0;
		cu->xl.flags = tmp << 4;
		if ((tmp = asc2nibble(cs[idx++])) > 0x0F)
			return 0;
		cu->xl.flags |= tmp;

		/* force CAN XL flag if it was missing in the ASCII string */
		cu->xl.flags |= CANXL_XLF;

		idx++; /* skip XL_HDR_DELIM */

		if ((tmp = asc2nibble(cs[idx++])) > 0x0F)
			return 0;
		cu->xl.sdt = tmp << 4;
		if ((tmp = asc2nibble(cs[idx++])) > 0x0F)
			return 0;
		cu->xl.sdt |= tmp;

		idx++; /* skip XL_HDR_DELIM */

		for (i = 0; i < 8; i++) {
			if ((tmp = asc2nibble(cs[idx++])) > 0x0F)
				return 0;
			cu->xl.af |= tmp << (7 - i) * 4;
		}

		idx++; /* skip CANID_DELIM */
	}

	for (i = 0, dlen = 0; i < maxdlen; i++) {
		if (cs[idx] == DATA_SEPERATOR) /* skip (optional) separator */
			idx++;

		if (idx >= len) /* end of string => end of data */
			break;

		if ((tmp = asc2nibble(cs[idx++])) > 0x0F)
			return 0;
		data[i] = tmp << 4;
		if ((tmp = asc2nibble(cs[idx++])) > 0x0F)
			return 0;
		data[i] |= tmp;
		dlen++;
	}

	if (mtu == CANXL_MTU)
		cu->xl.len = dlen;
	else
		cu->fd.len = dlen;

	/* check for extra DLC when having a Classic CAN with 8 bytes payload */
	if ((maxdlen == CAN_MAX_DLEN) && (dlen == CAN_MAX_DLEN) && (cs[idx++] == CC_DLC_DELIM)) {
		unsigned char dlc = asc2nibble(cs[idx]);

		if ((dlc > CAN_MAX_DLEN) && (dlc <= CAN_MAX_RAW_DLC))
			cu->cc.len8_dlc = dlc;
	}

	return mtu;
}

int snprintf_canframe(char *buf, size_t size, cu_t *cu, int sep)
{
	/* documentation see lib.h */

	unsigned char is_canfd = cu->fd.flags;
	int i, offset;
	int len;

	/* ensure space for string termination */
	if (size < 1)
		return size;

	/* handle CAN XL frames */
	if (cu->xl.flags & CANXL_XLF) {
		len = cu->xl.len;

		/* check if the CAN frame fits into the provided buffer */
		if (sizeof("00123#11:22:12345678#") + 2 * len + (sep ? len : 0) > size - 1) {
			/* mark buffer overflow in output */
			memset(buf, '-', size - 1);
			buf[size - 1] = 0;
			return size;
		}

		/* print prio and CAN XL header content */
		offset = sprintf(buf, "%02X%03X#%02X:%02X:%08X#",
				 (canid_t)(cu->xl.prio & CANXL_VCID_MASK) >> CANXL_VCID_OFFSET,
				 (canid_t)(cu->xl.prio & CANXL_PRIO_MASK),
				 cu->xl.flags, cu->xl.sdt, cu->xl.af);

		/* data */
		for (i = 0; i < len; i++) {
			put_hex_byte(buf + offset, cu->xl.data[i]);
			offset += 2;
			if (sep && (i + 1 < len))
				buf[offset++] = '.';
		}

		buf[offset] = 0;

		return offset;
	}

	/* handle CAN CC/FD frames - ensure max length values */
	if (is_canfd)
		len = (cu->fd.len > CANFD_MAX_DLEN) ? CANFD_MAX_DLEN : cu->fd.len;
	else
		len = (cu->fd.len > CAN_MAX_DLEN) ? CAN_MAX_DLEN : cu->fd.len;

	/* check if the CAN frame fits into the provided buffer */
	if (sizeof("12345678#_F") + 2 * len + (sep ? len : 0) +	\
	    (cu->fd.can_id & CAN_RTR_FLAG ? 2 : 0) > size - 1) {
		/* mark buffer overflow in output */
		memset(buf, '-', size - 1);
		buf[size - 1] = 0;
		return size;
	}

	if (cu->fd.can_id & CAN_ERR_FLAG) {
		put_eff_id(buf, cu->fd.can_id & (CAN_ERR_MASK | CAN_ERR_FLAG));
		buf[8] = '#';
		offset = 9;
	} else if (cu->fd.can_id & CAN_EFF_FLAG) {
		put_eff_id(buf, cu->fd.can_id & CAN_EFF_MASK);
		buf[8] = '#';
		offset = 9;
	} else {
		put_sff_id(buf, cu->fd.can_id & CAN_SFF_MASK);
		buf[3] = '#';
		offset = 4;
	}

	/* CAN CC frames may have RTR enabled. There are no ERR frames with RTR */
	if (!is_canfd && cu->fd.can_id & CAN_RTR_FLAG) {
		buf[offset++] = 'R';
		/* print a given CAN 2.0B DLC if it's not zero */
		if (len && len <= CAN_MAX_DLEN) {
			buf[offset++] = hex_asc_upper_lo(cu->fd.len);

			/* check for optional raw DLC value for CAN 2.0B frames */
			if (len == CAN_MAX_DLEN) {
				if ((cu->cc.len8_dlc > CAN_MAX_DLEN) && (cu->cc.len8_dlc <= CAN_MAX_RAW_DLC)) {
					buf[offset++] = CC_DLC_DELIM;
					buf[offset++] = hex_asc_upper_lo(cu->cc.len8_dlc);
				}
			}
		}

		buf[offset] = 0;
		return offset;
	}

	/* any CAN FD flags */
	if (is_canfd) {
		/* add CAN FD specific escape char and flags */
		buf[offset++] = '#';
		buf[offset++] = hex_asc_upper_lo(cu->fd.flags);
		if (sep && len)
			buf[offset++] = '.';
	}

	/* data */
	for (i = 0; i < len; i++) {
		put_hex_byte(buf + offset, cu->fd.data[i]);
		offset += 2;
		if (sep && (i + 1 < len))
			buf[offset++] = '.';
	}

	/* check for extra DLC when having a Classic CAN with 8 bytes payload */
	if (!is_canfd && (len == CAN_MAX_DLEN)) {
		unsigned char dlc = cu->cc.len8_dlc;

		if ((dlc > CAN_MAX_DLEN) && (dlc <= CAN_MAX_RAW_DLC)) {
			buf[offset++] = CC_DLC_DELIM;
			buf[offset++] = hex_asc_upper_lo(dlc);
		}
	}

	buf[offset] = 0;

	return offset;
}

int snprintf_long_canframe(char *buf, size_t size, cu_t *cu, int view)
{
	/* documentation see lib.h */

	unsigned char is_canfd = cu->fd.flags;
	int i, j, dlen, offset;
	size_t maxsize;
	int len;

	/* ensure space for string termination */
	if (size < 1)
		return size;

	/* handle CAN XL frames */
	if (cu->xl.flags & CANXL_XLF) {
		len = cu->xl.len;

		/* crop to CANFD_MAX_DLEN */
		if (len > CANFD_MAX_DLEN)
			dlen = CANFD_MAX_DLEN;
		else
			dlen = len;

		/* check if the CAN frame fits into the provided buffer */
		if (sizeof(".....123 [2048] (00|11:22:12345678)  ...") + 3 * dlen > size - 1) {
			/* mark buffer overflow in output */
			memset(buf, '-', size - 1);
			buf[size - 1] = 0;
			return size;
		}

		if (view & CANLIB_VIEW_INDENT_SFF) {
			memset(buf, ' ', 5);
			put_sff_id(buf + 5, cu->xl.prio & CANXL_PRIO_MASK);
			offset = 8;
		} else {
			put_sff_id(buf, cu->xl.prio & CANXL_PRIO_MASK);
			offset = 3;
		}

		/* print prio and CAN XL header content */
		offset += sprintf(buf + offset, " [%04d] (%02X|%02X:%02X:%08X) ",
				  len,
				  (canid_t)(cu->xl.prio & CANXL_VCID_MASK) >> CANXL_VCID_OFFSET,
				  cu->xl.flags, cu->xl.sdt, cu->xl.af);

		for (i = 0; i < dlen; i++) {
			put_hex_byte(buf + offset, cu->xl.data[i]);
			offset += 2;
			if (i + 1 < dlen)
				buf[offset++] = ' ';
		}

		/* indicate cropped output */
		if (cu->xl.len > dlen)
			offset += sprintf(buf + offset, " ...");

		buf[offset] = 0;

		return offset;
	}

	/* ensure max length values */
	if (is_canfd)
		len = (cu->fd.len > CANFD_MAX_DLEN) ? CANFD_MAX_DLEN : cu->fd.len;
	else
		len = (cu->fd.len > CAN_MAX_DLEN) ? CAN_MAX_DLEN : cu->fd.len;

	/* check if the CAN frame fits into the provided buffer */
	maxsize = sizeof("12345678  [12]  ");
	if (view & CANLIB_VIEW_BINARY)
		dlen = 9; /* _10101010 */
	else
		dlen = 3; /* _AA */

	if (cu->fd.can_id & CAN_RTR_FLAG) {
		maxsize += sizeof("    remote request");
	} else {
		maxsize += len * dlen;

		if (len <= CAN_MAX_DLEN) {
			if (cu->fd.can_id & CAN_ERR_FLAG) {
				maxsize += sizeof("    ERRORFRAME");
				maxsize += (8 - len) * dlen;
			} else if (view & CANLIB_VIEW_ASCII) {
				maxsize += sizeof("    'a.b.CDEF'");
				maxsize += (8 - len) * dlen;
			}
		}
	}

	if (maxsize > size - 1) {
		/* mark buffer overflow in output */
		memset(buf, '-', size - 1);
		buf[size - 1] = 0;
		return size;
	}

	/* initialize space for CAN-ID and length information */
	memset(buf, ' ', 15);

	if (cu->cc.can_id & CAN_ERR_FLAG) {
		put_eff_id(buf, cu->cc.can_id & (CAN_ERR_MASK | CAN_ERR_FLAG));
		offset = 10;
	} else if (cu->fd.can_id & CAN_EFF_FLAG) {
		put_eff_id(buf, cu->fd.can_id & CAN_EFF_MASK);
		offset = 10;
	} else {
		if (view & CANLIB_VIEW_INDENT_SFF) {
			put_sff_id(buf + 5, cu->fd.can_id & CAN_SFF_MASK);
			offset = 10;
		} else {
			put_sff_id(buf, cu->fd.can_id & CAN_SFF_MASK);
			offset = 5;
		}
	}

	/* The len value is sanitized (see above) */
	if (!is_canfd) {
		if (view & CANLIB_VIEW_LEN8_DLC) {
			unsigned char dlc = cu->cc.len8_dlc;

			/* fall back to len if we don't have a valid DLC > 8 */
			if (!((len == CAN_MAX_DLEN) && (dlc > CAN_MAX_DLEN) &&
			      (dlc <= CAN_MAX_RAW_DLC)))
				dlc = len;

			buf[offset + 1] = '{';
			buf[offset + 2] = hex_asc_upper[dlc];
			buf[offset + 3] = '}';
		} else {
			buf[offset + 1] = '[';
			buf[offset + 2] = len + '0';
			buf[offset + 3] = ']';
		}

		/* standard CAN frames may have RTR enabled */
		if (cu->fd.can_id & CAN_RTR_FLAG) {
			offset += sprintf(buf + offset + 5, " remote request");
			return offset + 5;
		}
	} else {
		buf[offset] = '[';
		buf[offset + 1] = (len / 10) + '0';
		buf[offset + 2] = (len % 10) + '0';
		buf[offset + 3] = ']';
	}
	offset += 5;

	if (view & CANLIB_VIEW_BINARY) {
		/* _10101010 - dlen = 9, see above */
		if (view & CANLIB_VIEW_SWAP) {
			for (i = len - 1; i >= 0; i--) {
				buf[offset++] = (i == len - 1) ? ' ' : SWAP_DELIMITER;
				for (j = 7; j >= 0; j--)
					buf[offset++] = (1 << j & cu->fd.data[i]) ? '1' : '0';
			}
		} else {
			for (i = 0; i < len; i++) {
				buf[offset++] = ' ';
				for (j = 7; j >= 0; j--)
					buf[offset++] = (1 << j & cu->fd.data[i]) ? '1' : '0';
			}
		}
	} else {
		/* _AA - dlen = 3, see above */
		if (view & CANLIB_VIEW_SWAP) {
			for (i = len - 1; i >= 0; i--) {
				if (i == len - 1)
					buf[offset++] = ' ';
				else
					buf[offset++] = SWAP_DELIMITER;

				put_hex_byte(buf + offset, cu->fd.data[i]);
				offset += 2;
			}
		} else {
			for (i = 0; i < len; i++) {
				buf[offset++] = ' ';
				put_hex_byte(buf + offset, cu->fd.data[i]);
				offset += 2;
			}
		}
	}

	buf[offset] = 0; /* terminate string */

	/*
	 * The ASCII & ERRORFRAME output is put at a fixed len behind the data.
	 * For now we support ASCII output only for payload length up to 8 bytes.
	 * Does it make sense to write 64 ASCII byte behind 64 ASCII HEX data on the console?
	 */
	if (len > CAN_MAX_DLEN)
		return offset;

	if (cu->fd.can_id & CAN_ERR_FLAG)
		offset += sprintf(buf + offset, "%*s", dlen * (8 - len) + 13, "ERRORFRAME");
	else if (view & CANLIB_VIEW_ASCII) {
		j = dlen * (8 - len) + 4;
		if (view & CANLIB_VIEW_SWAP) {
			sprintf(buf + offset, "%*s", j, "`");
			offset += j;
			for (i = len - 1; i >= 0; i--)
				if ((cu->fd.data[i] > 0x1F) && (cu->fd.data[i] < 0x7F))
					buf[offset++] = cu->fd.data[i];
				else
					buf[offset++] = '.';

			offset += sprintf(buf + offset, "`");
		} else {
			sprintf(buf + offset, "%*s", j, "'");
			offset += j;
			for (i = 0; i < len; i++)
				if ((cu->fd.data[i] > 0x1F) && (cu->fd.data[i] < 0x7F))
					buf[offset++] = cu->fd.data[i];
				else
					buf[offset++] = '.';

			offset += sprintf(buf + offset, "'");
		}
	}

	return offset;
}

static const char *error_classes[] = {
	"tx-timeout",
	"lost-arbitration",
	"controller-problem",
	"protocol-violation",
	"transceiver-status",
	"no-acknowledgement-on-tx",
	"bus-off",
	"bus-error",
	"restarted-after-bus-off",
	"error-counter-tx-rx",
};

static const char *controller_problems[] = {
	"rx-overflow",
	"tx-overflow",
	"rx-error-warning",
	"tx-error-warning",
	"rx-error-passive",
	"tx-error-passive",
	"back-to-error-active",
};

static const char *protocol_violation_types[] = {
	"single-bit-error",
	"frame-format-error",
	"bit-stuffing-error",
	"tx-dominant-bit-error",
	"tx-recessive-bit-error",
	"bus-overload",
	"active-error",
	"error-on-tx",
};

static const char *protocol_violation_locations[] = {
	"unspecified",
	"unspecified",
	"id.28-to-id.21",
	"start-of-frame",
	"bit-srtr",
	"bit-ide",
	"id.20-to-id.18",
	"id.17-to-id.13",
	"crc-sequence",
	"reserved-bit-0",
	"data-field",
	"data-length-code",
	"bit-rtr",
	"reserved-bit-1",
	"id.4-to-id.0",
	"id.12-to-id.5",
	"unspecified",
	"active-error-flag",
	"intermission",
	"tolerate-dominant-bits",
	"unspecified",
	"unspecified",
	"passive-error-flag",
	"error-delimiter",
	"crc-delimiter",
	"acknowledge-slot",
	"end-of-frame",
	"acknowledge-delimiter",
	"overload-flag",
	"unspecified",
	"unspecified",
	"unspecified",
};

#ifndef ARRAY_SIZE
#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
#endif

static int snprintf_error_data(char *buf, size_t len, uint8_t err,
			       const char **arr, int arr_len)
{
	int i, n = 0, count = 0;

	if (!err || len <= 0)
		return 0;

	for (i = 0; i < arr_len; i++) {
		if (err & (1 << i)) {
			int tmp_n = 0;
			if (count) {
				/* Fix for potential buffer overflow https://lgtm.com/rules/1505913226124/ */
				tmp_n = snprintf(buf + n, len - n, ",");
				if (tmp_n < 0 || (size_t)tmp_n >= len - n) {
					return n;
				}
				n += tmp_n;
			}
			tmp_n = snprintf(buf + n, len - n, "%s", arr[i]);
			if (tmp_n < 0 || (size_t)tmp_n >= len - n) {
				return n;
			}
			n += tmp_n;
			count++;
		}
	}

	return n;
}

static int snprintf_error_lostarb(char *buf, size_t len, const struct canfd_frame *cf)
{
	if (len <= 0)
		return 0;
	return snprintf(buf, len, "{at bit %d}", cf->data[0]);
}

static int snprintf_error_ctrl(char *buf, size_t len, const struct canfd_frame *cf)
{
	int n = 0;

	if (len <= 0)
		return 0;

	n += snprintf(buf + n, len - n, "{");
	n += snprintf_error_data(buf + n, len - n, cf->data[1],
				controller_problems,
				ARRAY_SIZE(controller_problems));
	n += snprintf(buf + n, len - n, "}");

	return n;
}

static int snprintf_error_prot(char *buf, size_t len, const struct canfd_frame *cf)
{
	int n = 0;

	if (len <= 0)
		return 0;

	n += snprintf(buf + n, len - n, "{{");
	n += snprintf_error_data(buf + n, len - n, cf->data[2],
				protocol_violation_types,
				ARRAY_SIZE(protocol_violation_types));
	n += snprintf(buf + n, len - n, "}{");
	if (cf->data[3] > 0 &&
	    cf->data[3] < ARRAY_SIZE(protocol_violation_locations))
		n += snprintf(buf + n, len - n, "%s",
			      protocol_violation_locations[cf->data[3]]);
	n += snprintf(buf + n, len - n, "}}");

	return n;
}

static int snprintf_error_cnt(char *buf, size_t len, const struct canfd_frame *cf)
{
	int n = 0;

	if (len <= 0)
		return 0;

	n += snprintf(buf + n, len - n, "{{%d}{%d}}",
		      cf->data[6], cf->data[7]);

	return n;
}

int snprintf_can_error_frame(char *buf, size_t len, const struct canfd_frame *cf,
                  const char* sep)
{
	canid_t class, mask;
	int i, n = 0, classes = 0;
	char *defsep = ",";

	if (!(cf->can_id & CAN_ERR_FLAG))
		return 0;

	class = cf->can_id & CAN_EFF_MASK;
	if (class > (1 << ARRAY_SIZE(error_classes))) {
		fprintf(stderr, "Error class %#x is invalid\n", class);
		return 0;
	}

	if (!sep)
		sep = defsep;

	for (i = 0; i < (int)ARRAY_SIZE(error_classes); i++) {
		mask = 1 << i;
		if (class & mask) {
			int tmp_n = 0;
			if (classes) {
				/* Fix for potential buffer overflow https://lgtm.com/rules/1505913226124/ */
				tmp_n = snprintf(buf + n, len - n, "%s", sep);
				if (tmp_n < 0 || (size_t)tmp_n >= len - n) {
					buf[0] = 0; /* empty terminated string */
					return 0;
				}
				n += tmp_n;
			}
			tmp_n = snprintf(buf + n, len - n, "%s", error_classes[i]);
			if (tmp_n < 0 || (size_t)tmp_n >= len - n) {
				buf[0] = 0; /* empty terminated string */
				return 0;
			}
			n += tmp_n;
			if (mask == CAN_ERR_LOSTARB)
				n += snprintf_error_lostarb(buf + n, len - n,
							   cf);
			if (mask == CAN_ERR_CRTL)
				n += snprintf_error_ctrl(buf + n, len - n, cf);
			if (mask == CAN_ERR_PROT)
				n += snprintf_error_prot(buf + n, len - n, cf);
			if (mask == CAN_ERR_CNT)
				n += snprintf_error_cnt(buf + n, len - n, cf);
			classes++;
		}
	}

	if (!(cf->can_id & CAN_ERR_CNT) && (cf->data[6] || cf->data[7])) {
		n += snprintf(buf + n, len - n, "%serror-counter-tx-rx", sep);
		n += snprintf_error_cnt(buf + n, len - n, cf);
	}

	return n;
}

int64_t timespec_diff_ms(struct timespec *ts1,
					  struct timespec *ts2)
{
	int64_t diff = (ts1->tv_sec - ts2->tv_sec) * 1000;

	diff += (ts1->tv_nsec - ts2->tv_nsec) / 1000000;

	return diff;
}

void timespec_add_ms(struct timespec *ts, uint64_t milliseconds)
{
	uint64_t total_ns = ts->tv_nsec + (milliseconds * 1000000);

	ts->tv_sec += total_ns / 1000000000;
	ts->tv_nsec = total_ns % 1000000000;
}