/*####COPYRIGHTBEGIN#### ------------------------------------------- Copyright (C) 2004 Steve Karg This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. 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. 59 Temple Place - Suite 330 Boston, MA 02111-1307, USA. As a special exception, if other files instantiate templates or use macros or inline functions from this file, or you compile this file and link it with other works to produce a work based on this file, this file does not by itself cause the resulting work to be covered by the GNU General Public License. However the source code for this file must still be made available in accordance with section (3) of the GNU General Public License. This exception does not invalidate any other reasons why a work based on this file might be covered by the GNU General Public License. ------------------------------------------- ####COPYRIGHTEND####*/ #include #include "bacdef.h" #include "bacdcode.h" #include "bacenum.h" #include "bits.h" #include "bigend.h" // NOTE: byte order plays a role in decoding multibyte values // http://www.unixpapa.com/incnote/byteorder.html /* max-segments-accepted B'000' Unspecified number of segments accepted. B'001' 2 segments accepted. B'010' 4 segments accepted. B'011' 8 segments accepted. B'100' 16 segments accepted. B'101' 32 segments accepted. B'110' 64 segments accepted. B'111' Greater than 64 segments accepted. */ /* max-APDU-length-accepted B'0000' Up to MinimumMessageSize (50 octets) B'0001' Up to 128 octets B'0010' Up to 206 octets (fits in a LonTalk frame) B'0011' Up to 480 octets (fits in an ARCNET frame) B'0100' Up to 1024 octets B'0101' Up to 1476 octets (fits in an ISO 8802-3 frame) B'0110' reserved by ASHRAE B'0111' reserved by ASHRAE B'1000' reserved by ASHRAE B'1001' reserved by ASHRAE B'1010' reserved by ASHRAE B'1011' reserved by ASHRAE B'1100' reserved by ASHRAE B'1101' reserved by ASHRAE B'1110' reserved by ASHRAE B'1111' reserved by ASHRAE */ // from clause 20.1.2.4 max-segments-accepted // and clause 20.1.2.5 max-APDU-length-accepted // returns the encoded octet uint8_t encode_max_segs_max_apdu(int max_segs, int max_apdu) { uint8_t octet = 0; if (max_segs < 2) octet = 0; else if (max_segs < 4) octet = 0x10; else if (max_segs < 8) octet = 0x20; else if (max_segs < 16) octet = 0x30; else if (max_segs < 32) octet = 0x40; else if (max_segs < 64) octet = 0x50; else if (max_segs == 64) octet = 0x60; else octet = 0x70; // max_apdu must be 50 octets minimum if (max_apdu <= 50) octet |= 0x00; else if (max_apdu <= 128) octet |= 0x01; //fits in a LonTalk frame else if (max_apdu <= 206) octet |= 0x02; //fits in an ARCNET or MS/TP frame else if (max_apdu <= 480) octet |= 0x03; else if (max_apdu <= 1024) octet |= 0x04; // fits in an ISO 8802-3 frame else if (max_apdu <= 1476) octet |= 0x05; return octet; } // from clause 20.1.2.4 max-segments-accepted // and clause 20.1.2.5 max-APDU-length-accepted // returns the encoded octet int decode_max_segs(uint8_t octet) { int max_segs = 0; switch (octet & 0xF0) { case 0: max_segs = 0; break; case 0x10: max_segs = 2; break; case 0x20: max_segs = 4; break; case 0x30: max_segs = 8; break; case 0x40: max_segs = 16; break; case 0x50: max_segs = 32; break; case 0x60: max_segs = 64; break; case 0x70: max_segs = 65; break; default: break; } return max_segs; } int decode_max_apdu(uint8_t octet) { int max_apdu = 0; switch (octet & 0x0F) { case 0: max_apdu = 50; break; case 1: max_apdu = 128; break; case 2: max_apdu = 206; break; case 3: max_apdu = 480; break; case 4: max_apdu = 1024; break; case 5: max_apdu = 1476; break; default: break; } return max_apdu; } int encode_unsigned16(uint8_t * apdu, uint16_t value) { union { uint8_t byte[2]; uint16_t value; } short_data = {{0}}; short_data.value = value; if (big_endian()) { apdu[0] = short_data.byte[0]; apdu[1] = short_data.byte[1]; } else { apdu[0] = short_data.byte[1]; apdu[1] = short_data.byte[0]; } return 2; } int decode_unsigned16(uint8_t * apdu, uint16_t *value) { union { uint8_t byte[2]; uint16_t value; } short_data = {{0}}; if (big_endian()) { short_data.byte[0] = apdu[0]; short_data.byte[1] = apdu[1]; } else { short_data.byte[1] = apdu[0]; short_data.byte[0] = apdu[1]; } if (value) *value = short_data.value; return 2; } int encode_unsigned32(uint8_t * apdu, uint32_t value) { union { uint8_t byte[4]; uint32_t value; } long_data = {{0}}; long_data.value = value; if (big_endian()) { apdu[0] = long_data.byte[0]; apdu[1] = long_data.byte[1]; apdu[2] = long_data.byte[2]; apdu[3] = long_data.byte[3]; } else { apdu[0] = long_data.byte[3]; apdu[1] = long_data.byte[2]; apdu[2] = long_data.byte[1]; apdu[3] = long_data.byte[0]; } return 4; } int decode_unsigned32(uint8_t * apdu, uint32_t *value) { union { uint8_t byte[4]; uint32_t value; } long_data = {{0}}; if (big_endian()) { long_data.byte[0] = apdu[0]; long_data.byte[1] = apdu[1]; long_data.byte[2] = apdu[2]; long_data.byte[3] = apdu[3]; } else { long_data.byte[3] = apdu[0]; long_data.byte[2] = apdu[1]; long_data.byte[1] = apdu[2]; long_data.byte[0] = apdu[3]; } if (value) *value = long_data.value; return 4; } void bitstring_init(BACNET_BIT_STRING *bit_string) { int i; bit_string->bits_used = 0; for (i = 0; i < MAX_BITSTRING_BYTES; i++) { bit_string->value[i] = 0; } } void bitstring_set_bit(BACNET_BIT_STRING *bit_string, uint8_t bit, bool value) { uint8_t byte_number = bit/8; uint8_t bit_mask = 1; if (byte_number < MAX_BITSTRING_BYTES) { // set max bits used if (bit_string->bits_used < (bit + 1)) bit_string->bits_used = bit + 1; bit_mask = bit_mask << (bit - (byte_number * 8)); if (value) bit_string->value[byte_number] |= bit_mask; else bit_string->value[byte_number] &= (~(bit_mask)); } } bool bitstring_bit(BACNET_BIT_STRING *bit_string, uint8_t bit) { bool value = false; uint8_t byte_number = bit/8; uint8_t bit_mask = 1; if (bit < (MAX_BITSTRING_BYTES * 8)) { bit_mask = bit_mask << (bit - (byte_number * 8)); if (bit_string->value[byte_number] & bit_mask) value = true; } return value; } uint8_t bitstring_bits_used(BACNET_BIT_STRING *bit_string) { return bit_string->bits_used; } // from clause 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_tag(uint8_t * apdu, uint8_t tag_number, bool context_specific, uint32_t len_value_type) { int len = 1; // return value apdu[0] = 0; if (context_specific) apdu[0] = BIT3; // additional tag byte after this byte // for extended tag byte if (tag_number <= 14) apdu[0] |= (tag_number << 4); else { apdu[0] |= 0xF0; apdu[1] = tag_number; len++; } // NOTE: additional len byte(s) after extended tag byte // if larger than 4 if (len_value_type <= 4) apdu[0] |= len_value_type; else { apdu[0] |= 5; if (len_value_type <= 253) { apdu[len++] = len_value_type; } else if (len_value_type <= 65535) { apdu[len++] = 254; len += encode_unsigned16(&apdu[len], len_value_type); } else { apdu[len++] = 255; len += encode_unsigned32(&apdu[len], len_value_type); } } return len; } // from clause 20.2.1.3.2 Constructed Data // returns the number of apdu bytes consumed int encode_opening_tag(uint8_t * apdu, uint8_t tag_number) { int len = 1; apdu[0] = BIT3; // additional tag byte after this byte for extended tag byte if (tag_number <= 14) apdu[0] |= (tag_number << 4); else { apdu[0] |= 0xF0; apdu[1] = tag_number; len++; } // type indicates opening tag apdu[0] |= 6; return len; } // from clause 20.2.1.3.2 Constructed Data // returns the number of apdu bytes consumed int encode_closing_tag(uint8_t * apdu, uint8_t tag_number) { int len = 1; apdu[0] = BIT3; // additional tag byte after this byte for extended tag byte if (tag_number <= 14) apdu[0] |= (tag_number << 4); else { apdu[0] |= 0xF0; apdu[1] = tag_number; len++; } // type indicates closing tag apdu[0] |= 7; return len; } // from clause 20.2.1.3.2 Constructed Data // returns true if extended tag numbering is used static bool decode_is_extended_tag_number(uint8_t * apdu) { return ((apdu[0] & 0xF0) == 0xF0); } // from clause 20.2.1.3.2 Constructed Data // returns true if the extended value is used static bool decode_is_extended_value(uint8_t * apdu) { return ((apdu[0] & 0x07) == 5); } // from clause 20.2.1.3.2 Constructed Data // returns true if the tag is context specific bool decode_is_context_specific(uint8_t * apdu) { return ((apdu[0] & BIT3) == BIT3); } int decode_tag_number(uint8_t * apdu, uint8_t * tag_number) { int len = 1; // return value // decode the tag number first if (decode_is_extended_tag_number(&apdu[0])) { // extended tag if (tag_number) *tag_number = apdu[1]; len++; } else { if (tag_number) *tag_number = (apdu[0] >> 4); } return len; } static bool decode_is_opening_tag(uint8_t * apdu) { return ((apdu[0] & 0x07) == 6); } // from clause 20.2.1.3.2 Constructed Data // returns the number of apdu bytes consumed static bool decode_is_closing_tag(uint8_t * apdu) { return ((apdu[0] & 0x07) == 7); } // from clause 20.2.1.3.2 Constructed Data // returns the number of apdu bytes consumed // from clause 20.2.1.3.2 Constructed Data // returns the number of apdu bytes consumed int decode_tag_number_and_value(uint8_t * apdu, uint8_t * tag_number, uint32_t * value) { int len = 1; uint16_t value16; uint32_t value32; len = decode_tag_number(&apdu[0], tag_number); // decode the value if (decode_is_extended_value(&apdu[0])) { // tagged as uint32_t if (apdu[len] == 255) { len++; len += decode_unsigned32(&apdu[len], &value32); if (value) *value = value32; } // tagged as uint16_t else if (apdu[len] == 254) { len++; len += decode_unsigned16(&apdu[len], &value16); if (value) *value = value16; } // no tag - must be uint8_t else { if (value) *value = apdu[len]; len++; } } else if (decode_is_opening_tag(&apdu[0]) && value) *value = 0; // closing tag else if (decode_is_closing_tag(&apdu[0]) && value) *value = 0; // small value else if (value) *value = apdu[0] & 0x07; return len; } // from clause 20.2.1.3.2 Constructed Data // returns true if the tag is context specific and matches bool decode_is_context_tag(uint8_t * apdu, uint8_t tag_number) { uint8_t my_tag_number = 0; bool context_specific = false; context_specific = decode_is_context_specific(apdu); decode_tag_number(apdu, &my_tag_number); return (context_specific && (my_tag_number == tag_number)); } // from clause 20.2.1.3.2 Constructed Data // returns the number of apdu bytes consumed bool decode_is_opening_tag_number(uint8_t * apdu, uint8_t tag_number) { uint8_t my_tag_number = 0; bool opening_tag = false; opening_tag = ((apdu[0] & 0x07) == 6); decode_tag_number(apdu, &my_tag_number); return (opening_tag && (my_tag_number == tag_number)); } // from clause 20.2.1.3.2 Constructed Data // returns the number of apdu bytes consumed bool decode_is_closing_tag_number(uint8_t * apdu, uint8_t tag_number) { uint8_t my_tag_number = 0; bool closing_tag = false; closing_tag = ((apdu[0] & 0x07) == 7); decode_tag_number(apdu, &my_tag_number); return (closing_tag && (my_tag_number == tag_number)); } // from clause 20.2.3 Encoding of a Boolean Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_tagged_boolean(uint8_t * apdu, bool boolean_value) { int len = 0; uint32_t len_value = 0; if (boolean_value) len_value = 1; len = encode_tag(&apdu[0], BACNET_APPLICATION_TAG_BOOLEAN, false, len_value); return len; } // context tagged is encoded differently int encode_context_boolean(uint8_t * apdu, bool boolean_value) { apdu[0] = boolean_value ? 1 : 0; return 1; } bool decode_context_boolean(uint8_t * apdu) { bool boolean_value = false; if (apdu[0]) boolean_value = true; return boolean_value; } // from clause 20.2.3 Encoding of a Boolean Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed bool decode_boolean(uint32_t len_value) { bool boolean_value = false; if (len_value) boolean_value = true; return boolean_value; } // from clause 20.2.2 Encoding of a Null Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_tagged_null(uint8_t * apdu) { return encode_tag(&apdu[0], BACNET_APPLICATION_TAG_NULL, false, 0); } static uint8_t byte_reverse_bits(uint8_t in_byte) { uint8_t out_byte = 0; if (in_byte & BIT0) out_byte |= BIT7; if (in_byte & BIT1) out_byte |= BIT6; if (in_byte & BIT2) out_byte |= BIT5; if (in_byte & BIT3) out_byte |= BIT4; if (in_byte & BIT4) out_byte |= BIT3; if (in_byte & BIT5) out_byte |= BIT2; if (in_byte & BIT6) out_byte |= BIT1; if (in_byte & BIT7) out_byte |= BIT0; return out_byte; } // from clause 20.2.10 Encoding of a Bit String Value // returns the number of apdu bytes consumed int decode_bitstring(uint8_t * apdu, uint32_t len_value, BACNET_BIT_STRING *bit_string) { int len = 0; uint8_t unused_bits = 0; uint32_t i = 0; uint32_t bytes_used = 0; bitstring_init(bit_string); if (len_value) { // the first octet contains the unused bits bytes_used = len_value - 1; if (bytes_used <= MAX_BITSTRING_BYTES) { len = 1; for (i = 0; i < bytes_used; i++) { bit_string->value[i] = byte_reverse_bits(apdu[len++]); } unused_bits = apdu[0] & 0x07; bit_string->bits_used = bytes_used * 8; bit_string->bits_used -= unused_bits; } } return len; } // returns the number of bytes that a bit string is using static int bitstring_bytes_used(BACNET_BIT_STRING *bit_string) { int len = 0; // return value uint8_t used_bytes = 0; uint8_t last_bit = 0; if (bit_string->bits_used) { last_bit = bit_string->bits_used - 1; used_bytes = last_bit / 8; // add one for the first byte used_bytes++; len = used_bytes; } return len; } // from clause 20.2.10 Encoding of a Bit String Value // returns the number of apdu bytes consumed int encode_bitstring(uint8_t * apdu, BACNET_BIT_STRING *bit_string) { int len = 0; uint8_t remaining_used_bits = 0; uint8_t used_bytes = 0; uint8_t i = 0; // if the bit string is empty, then the first octet shall be zero if (bit_string->bits_used == 0) apdu[len++] = 0; else { used_bytes = bitstring_bytes_used(bit_string); remaining_used_bits = bit_string->bits_used - ((used_bytes - 1) * 8); // number of unused bits in the subsequent final octet apdu[len++] = 8 - remaining_used_bits; for (i = 0; i < used_bytes; i++) { apdu[len++] = byte_reverse_bits(bit_string->value[i]); } } return len; } int encode_tagged_bitstring(uint8_t * apdu, BACNET_BIT_STRING *bit_string) { int len = 0; int bit_string_encoded_length = 1;// 1 for the bits remaining octet // bit string may use more than 1 octet for the tag, so find out how many bit_string_encoded_length += bitstring_bytes_used(bit_string); len = encode_tag(&apdu[0], BACNET_APPLICATION_TAG_BIT_STRING, false, bit_string_encoded_length); len += encode_bitstring(&apdu[len], bit_string); return len; } // from clause 20.2.6 Encoding of a Real Number Value // returns the number of apdu bytes consumed int decode_real(uint8_t * apdu, float *real_value) { union { uint8_t byte[4]; float real_value; } my_data; if (big_endian()) { my_data.byte[0] = apdu[0]; my_data.byte[1] = apdu[1]; my_data.byte[2] = apdu[2]; my_data.byte[3] = apdu[3]; } else { my_data.byte[0] = apdu[3]; my_data.byte[1] = apdu[2]; my_data.byte[2] = apdu[1]; my_data.byte[3] = apdu[0]; } *real_value = my_data.real_value; return 4; } // from clause 20.2.6 Encoding of a Real Number Value // returns the number of apdu bytes consumed int encode_bacnet_real(float value, uint8_t * apdu) { union { uint8_t byte[4]; float real_value; } my_data; my_data.real_value = value; if (big_endian()) { apdu[0] = my_data.byte[0]; apdu[1] = my_data.byte[1]; apdu[2] = my_data.byte[2]; apdu[3] = my_data.byte[3]; } else { apdu[0] = my_data.byte[3]; apdu[1] = my_data.byte[2]; apdu[2] = my_data.byte[1]; apdu[3] = my_data.byte[0]; } return 4; } // from clause 20.2.6 Encoding of a Real Number Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_tagged_real(uint8_t * apdu, float value) { int len = 0; // assumes that the tag only consumes 1 octet len = encode_bacnet_real(value, &apdu[1]); len += encode_tag(&apdu[0], BACNET_APPLICATION_TAG_REAL, false, len); return len; } // from clause 20.2.14 Encoding of an Object Identifier Value // returns the number of apdu bytes consumed int decode_object_id( uint8_t *apdu, int *object_type, uint32_t *instance) { uint32_t value = 0; int len = 0; len = decode_unsigned32(apdu,&value); *object_type = ((value >> BACNET_INSTANCE_BITS) & BACNET_MAX_OBJECT); *instance = (value & BACNET_MAX_INSTANCE); return len; } // from clause 20.2.14 Encoding of an Object Identifier Value // returns the number of apdu bytes consumed int encode_bacnet_object_id( uint8_t * apdu, int object_type, uint32_t instance) { uint32_t value = 0; uint32_t type = 0; int len = 0; type = object_type; value = ((type & BACNET_MAX_OBJECT) << BACNET_INSTANCE_BITS) | (instance & BACNET_MAX_INSTANCE); len = encode_unsigned32(apdu,value); return len; } // from clause 20.2.14 Encoding of an Object Identifier Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_context_object_id( uint8_t * apdu, int tag_number, int object_type, uint32_t instance) { int len = 0; // assumes that the tag only consumes 1 octet len = encode_bacnet_object_id(&apdu[1], object_type, instance); len += encode_tag(&apdu[0], tag_number, true, len); return len; } // from clause 20.2.14 Encoding of an Object Identifier Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_tagged_object_id( uint8_t * apdu, int object_type, uint32_t instance) { int len = 0; // assumes that the tag only consumes 1 octet len = encode_bacnet_object_id(&apdu[1], object_type, instance); len += encode_tag(&apdu[0], BACNET_APPLICATION_TAG_OBJECT_ID, false, len); return len; } // from clause 20.2.9 Encoding of a Character String Value // returns the number of apdu bytes consumed int encode_bacnet_string(uint8_t * apdu, const char *char_string, int len) { int i; // limit - 6 octets is the most our tag and type could be if (len > (MAX_APDU - 6)) len = MAX_APDU - 6; for (i = 0; i < len; i++) { apdu[1 + i] = char_string[i]; } apdu[0] = CHARACTER_ANSI; len++; return len; } // from clause 20.2.9 Encoding of a Character String Value // returns the number of apdu bytes consumed int encode_bacnet_character_string(uint8_t * apdu, const char *char_string) { int len; len = strlen(char_string); len = encode_bacnet_string(&apdu[0], char_string, len); return len; } // from clause 20.2.9 Encoding of a Character String Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_tagged_character_string(uint8_t * apdu, const char *char_string) { int len = 0; int string_len = 0; // find the size of the apdu first - not necessarily effecient // but reuses existing functions string_len = encode_bacnet_character_string(&apdu[1], char_string); len = encode_tag(&apdu[0], BACNET_APPLICATION_TAG_CHARACTER_STRING, false, string_len); if ((len + string_len) < MAX_APDU) len += encode_bacnet_character_string(&apdu[len], char_string); else len = 0; return len; } // from clause 20.2.9 Encoding of a Character String Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int decode_character_string(uint8_t * apdu, uint32_t len_value, char *char_string, size_t string_len) { int len = 0; // return value uint32_t i = 0; // counter // FIXME: issue warning? if (len_value > string_len) len_value = string_len; if (len_value) { // decode ANSI X3.4 if (apdu[len] == 0) { len++; len_value--; for (i = 0; i < len_value; i++) { char_string[i] = apdu[len + i]; } // terminate the c string char_string[i] = 0; len += len_value; } } return len; } // from clause 20.2.4 Encoding of an Unsigned Integer Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed // FIXME: What about endian? int encode_bacnet_unsigned(uint8_t * apdu, unsigned int value) { int len = 0; // return value if (value < 0x100) { apdu[0] = value; len = 1; } else if (value < 0x10000) { apdu[0] = value / 0x100; apdu[1] = value - (apdu[0] * 0x100); len = 2; } else if (value < 0x1000000) { apdu[0] = value / 0x10000; apdu[1] = (value - apdu[0] * 0x10000) / 0x100; apdu[2] = value - (apdu[0] * 0x10000) - (apdu[1] * 0x100); len = 3; } else { apdu[0] = value / 0x1000000; apdu[1] = (value - (apdu[0] * 0x1000000)) / 0x10000; apdu[2] = (value - (apdu[0] * 0x1000000) - (apdu[1] * 0x10000)) / 0x100; apdu[3] = value - (apdu[0] * 0x1000000) - (apdu[1] * 0x10000) - (apdu[2] * 0x100); len = 4; } return len; } // from clause 20.2.4 Encoding of an Unsigned Integer Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_context_unsigned(uint8_t * apdu, int tag_number, int value) { int len = 0; len = encode_bacnet_unsigned(&apdu[1], value); len += encode_tag(&apdu[0], tag_number, true, len); return len; } // from clause 20.2.4 Encoding of an Unsigned Integer Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_tagged_unsigned(uint8_t * apdu, unsigned int value) { int len = 0; len = encode_bacnet_unsigned(&apdu[1], value); len += encode_tag(&apdu[0], BACNET_APPLICATION_TAG_UNSIGNED_INT, false, len); return len; } // from clause 20.2.4 Encoding of an Unsigned Integer Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed // FIXME: What about endian? int decode_unsigned(uint8_t * apdu, uint32_t len_value, unsigned int *value) { int len = 0; // return value if (value) { switch (len_value) { case 1: *value = apdu[len]; break; case 2: *value = (apdu[len] * 0x100) + apdu[len + 1]; break; case 3: *value = (apdu[len] * 0x10000) + (apdu[len + 1] * 0x100) + apdu[len + 2]; break; case 4: *value = (apdu[len] * 0x1000000) + (apdu[len + 1] * 0x10000) + (apdu[len + 2] * 0x100) + apdu[len + 3]; break; default: *value = 0; break; } } len += len_value; return len; } // from clause 20.2.11 Encoding of an Enumerated Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int decode_enumerated(uint8_t * apdu, uint32_t len_value, int *value) { unsigned unsigned_value = 0; int len; len = decode_unsigned(apdu, len_value, &unsigned_value); if (value) *value = unsigned_value; return len; } // from clause 20.2.11 Encoding of an Enumerated Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_bacnet_enumerated(uint8_t * apdu, int value) { return encode_bacnet_unsigned(apdu, value); } // from clause 20.2.11 Encoding of an Enumerated Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_tagged_enumerated(uint8_t * apdu, int value) { int len = 0; // return value // assumes that the tag only consumes 1 octet len = encode_bacnet_enumerated(&apdu[1], value); len += encode_tag(&apdu[0], BACNET_APPLICATION_TAG_ENUMERATED, false, len); return len; } // from clause 20.2.11 Encoding of an Enumerated Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_context_enumerated(uint8_t * apdu, int tag_number, int value) { int len = 0; // return value // assumes that the tag only consumes 1 octet len = encode_bacnet_enumerated(&apdu[1], value); len += encode_tag(&apdu[0], tag_number, true, len); return len; } // from clause 20.2.5 Encoding of a Signed Integer Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int decode_signed(uint8_t * apdu, uint32_t len_value, int *value) { int len = 0; // return value if (value) { switch (len_value) { case 1: *value = apdu[len]; break; case 2: *value = (apdu[len] * 0x100) + apdu[len + 1]; break; case 3: *value = (apdu[len] * 0x10000) + (apdu[len + 1] * 0x100) + apdu[len + 2]; break; case 4: *value = (apdu[len] * 0x1000000) + (apdu[len + 1] * 0x10000) + (apdu[len + 2] * 0x100) + apdu[len + 3]; break; default: *value = 0; break; } } len += len_value; return len; } // from clause 20.2.5 Encoding of a Signed Integer Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_bacnet_signed(uint8_t * apdu, int value) { return encode_bacnet_unsigned(apdu, value); } // from clause 20.2.5 Encoding of a Signed Integer Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_tagged_signed(uint8_t * apdu, int value) { int len = 0; // return value // assumes that the tag only consumes 1 octet len = encode_bacnet_signed(&apdu[1], value); len += encode_tag(&apdu[0], BACNET_APPLICATION_TAG_SIGNED_INT, false, len); return len; } // from clause 20.2.5 Encoding of a Signed Integer Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_context_signed(uint8_t * apdu, int tag_number, int value) { int len = 0; // return value // assumes that the tag only consumes 1 octet len = encode_bacnet_signed(&apdu[1], value); len += encode_tag(&apdu[0], tag_number, true, len); return len; } // from clause 20.2.13 Encoding of a Time Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_bacnet_time(uint8_t * apdu, int hour, int min, int sec, int hundredths) { apdu[0] = hour; apdu[1] = min; apdu[2] = sec; apdu[3] = hundredths; return 4; } // from clause 20.2.13 Encoding of a Time Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_tagged_time(uint8_t * apdu, int hour, int min, int sec, int hundredths) { int len = 0; // assumes that the tag only consumes 1 octet len = encode_bacnet_time(&apdu[1], hour, min, sec, hundredths); len += encode_tag(&apdu[0], BACNET_APPLICATION_TAG_TIME, false, len); return len; } // from clause 20.2.13 Encoding of a Time Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int decode_bacnet_time(uint8_t * apdu, int *hour, int *min, int *sec, int *hundredths) { *hour = apdu[0]; *min = apdu[1]; *sec = apdu[2]; *hundredths = apdu[3]; return 4; } // BACnet Date // year = years since 1900 // month 1=Jan // day = day of month // wday 1=Monday...7=Sunday // from clause 20.2.12 Encoding of a Date Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_bacnet_date(uint8_t * apdu, int year, int month, int day, int wday) { apdu[0] = year; apdu[1] = month; apdu[2] = day; apdu[3] = wday; return 4; } // from clause 20.2.12 Encoding of a Date Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int encode_tagged_date(uint8_t * apdu, int year, int month, int day, int wday) { int len = 0; // assumes that the tag only consumes 1 octet len = encode_bacnet_date(&apdu[1], year, month, day, wday); len += encode_tag(&apdu[0], BACNET_APPLICATION_TAG_DATE, false, len); return len; } // from clause 20.2.12 Encoding of a Date Value // and 20.2.1 General Rules for Encoding BACnet Tags // returns the number of apdu bytes consumed int decode_date(uint8_t * apdu, int *year, int *month, int *day, int *wday) { *year = apdu[0]; *month = apdu[1]; *day = apdu[2]; *wday = apdu[3]; return 4; } // returns the number of apdu bytes consumed int encode_simple_ack(uint8_t * apdu, uint8_t invoke_id, uint8_t service_choice) { apdu[0] = PDU_TYPE_SIMPLE_ACK; apdu[1] = invoke_id; apdu[2] = service_choice; return 3; } /* end of decoding_encoding.c */ #ifdef TEST #include #include #include "ctest.h" static int get_apdu_len(bool extended_tag, uint32_t value) { int test_len = 1; if (extended_tag) test_len++; if (value <= 4) test_len += 0; // do nothing... else if (value <= 253) test_len += 1; else if (value <= 65535) test_len += 3; else test_len += 5; return test_len; } void testBACDCodeTags(Test * pTest) { uint8_t apdu[MAX_APDU] = { 0 }; uint8_t tag_number = 0, test_tag_number = 0; int len = 0, test_len = 0; uint32_t value = 0, test_value = 0; for (tag_number = 0;; tag_number++) { len = encode_opening_tag(&apdu[0], tag_number); test_len = get_apdu_len(decode_is_extended_tag_number(&apdu[0]), 0); ct_test(pTest, len == test_len); len = decode_tag_number_and_value(&apdu[0], &test_tag_number, &value); ct_test(pTest, value == 0); ct_test(pTest, len == test_len); ct_test(pTest, tag_number == test_tag_number); ct_test(pTest, decode_is_opening_tag(&apdu[0]) == true); ct_test(pTest, decode_is_closing_tag(&apdu[0]) == false); len = encode_closing_tag(&apdu[0], tag_number); ct_test(pTest, len == test_len); len = decode_tag_number_and_value(&apdu[0], &test_tag_number, &value); ct_test(pTest, len == test_len); ct_test(pTest, value == 0); ct_test(pTest, tag_number == test_tag_number); ct_test(pTest, decode_is_opening_tag(&apdu[0]) == false); ct_test(pTest, decode_is_closing_tag(&apdu[0]) == true); // test the len-value-type portion for (value = 1;; value = value << 1) { len = encode_tag(&apdu[0], tag_number, false, value); len = decode_tag_number_and_value(&apdu[0], &test_tag_number, &test_value); ct_test(pTest, tag_number == test_tag_number); ct_test(pTest, value == test_value); test_len = get_apdu_len(decode_is_extended_tag_number(&apdu[0]), value); ct_test(pTest, len == test_len); // stop at the the last value if (value & BIT31) break; } // stop after the last tag number if (tag_number == 255) break; } return; } void testBACDCodeReal(Test * pTest) { uint8_t real_array[4] = { 0 }; uint8_t encoded_array[4] = { 0 }; float value = 42.123; float decoded_value = 0; uint8_t apdu[MAX_APDU] = { 0 }; int len = 0, apdu_len = 0; uint8_t tag_number = 0; uint32_t long_value = 0; encode_bacnet_real(value, &real_array[0]); decode_real(&real_array[0], &decoded_value); ct_test(pTest, decoded_value == value); encode_bacnet_real(value, &encoded_array[0]); ct_test(pTest, memcmp(&real_array, &encoded_array, sizeof(real_array)) == 0); // a real will take up 4 octects plus a one octet tag apdu_len = encode_tagged_real(&apdu[0], value); ct_test(pTest, apdu_len == 5); // len tells us how many octets were used for encoding the value len = decode_tag_number_and_value(&apdu[0], &tag_number, &long_value); ct_test(pTest, tag_number == BACNET_APPLICATION_TAG_REAL); ct_test(pTest, decode_is_context_specific(&apdu[0]) == false); ct_test(pTest, len == 1); ct_test(pTest, long_value == 4); decode_real(&apdu[len], &decoded_value); ct_test(pTest, decoded_value == value); return; } void testBACDCodeEnumerated(Test * pTest) { uint8_t array[5] = { 0 }; uint8_t encoded_array[5] = { 0 }; int value = 1; int decoded_value = 0; int i = 0, apdu_len = 0; int len = 0; uint8_t apdu[MAX_APDU] = { 0 }; uint8_t tag_number = 0; uint32_t len_value = 0; for (i = 0; i < 8; i++) { apdu_len = encode_tagged_enumerated(&array[0], value); len = decode_tag_number_and_value(&array[0], &tag_number, &len_value); len += decode_enumerated(&array[len],len_value, &decoded_value); ct_test(pTest, decoded_value == value); ct_test(pTest, tag_number == BACNET_APPLICATION_TAG_ENUMERATED); ct_test(pTest, len == apdu_len); // encode back the value encode_tagged_enumerated(&encoded_array[0], decoded_value); ct_test(pTest, memcmp(&array[0], &encoded_array[0], sizeof(array)) == 0); // an enumerated will take up to 4 octects // plus a one octet for the tag apdu_len = encode_tagged_enumerated(&apdu[0], value); len = decode_tag_number_and_value(&apdu[0], &tag_number, NULL); ct_test(pTest, len == 1); ct_test(pTest, tag_number == BACNET_APPLICATION_TAG_ENUMERATED); ct_test(pTest, decode_is_context_specific(&apdu[0]) == false); // context specific encoding apdu_len = encode_context_enumerated(&apdu[0], 3, value); ct_test(pTest, decode_is_context_specific(&apdu[0]) == true); len = decode_tag_number_and_value(&apdu[0], &tag_number, NULL); ct_test(pTest, len == 1); ct_test(pTest, tag_number == 3); // test the interesting values value = value << 1; } return; } void testBACDCodeUnsigned(Test * pTest) { uint8_t array[5] = { 0 }; uint8_t encoded_array[5] = { 0 }; unsigned int value = 1; unsigned int decoded_value = 0; int i, len, apdu_len; uint8_t apdu[MAX_APDU] = { 0 }; uint8_t tag_number = 0; uint32_t len_value = 0; for (i = 0; i < 8; i++) { len_value = encode_tagged_unsigned(&array[0], value); len = decode_tag_number_and_value(&array[0], &tag_number, &len_value); len = decode_unsigned(&array[len], len_value, &decoded_value); ct_test(pTest, decoded_value == value); encode_tagged_unsigned(&encoded_array[0], decoded_value); ct_test(pTest, memcmp(&array[0], &encoded_array[0], sizeof(array)) == 0); // an unsigned will take up to 4 octects // plus a one octet for the tag apdu_len = encode_tagged_unsigned(&apdu[0], value); // apdu_len varies... //ct_test(pTest, apdu_len == 5); len = decode_tag_number_and_value(&apdu[0], &tag_number, NULL); ct_test(pTest, len == 1); ct_test(pTest, tag_number == BACNET_APPLICATION_TAG_UNSIGNED_INT); ct_test(pTest, decode_is_context_specific(&apdu[0]) == false); value = value << 1; } return; } void testBACDCodeSigned(Test * pTest) { uint8_t array[5] = { 0 }; uint8_t encoded_array[5] = { 0 }; int value = 1; int decoded_value = 0; int i = 0, len = 0, apdu_len = 0; uint8_t apdu[MAX_APDU] = { 0 }; uint8_t tag_number = 0; uint32_t len_value = 0; for (i = 0; i < 8; i++) { len = encode_tagged_signed(&array[0], value); len = decode_tag_number_and_value(&array[0], &tag_number, &len_value); len = decode_signed(&array[len], len_value, &decoded_value); ct_test(pTest, tag_number == BACNET_APPLICATION_TAG_SIGNED_INT); ct_test(pTest, decoded_value == value); encode_tagged_signed(&encoded_array[0], decoded_value); ct_test(pTest, memcmp(&array[0], &encoded_array[0], sizeof(array)) == 0); // a signed int will take up to 4 octects // plus a one octet for the tag apdu_len = encode_tagged_signed(&apdu[0], value); len = decode_tag_number_and_value(&apdu[0], &tag_number, NULL); ct_test(pTest, tag_number == BACNET_APPLICATION_TAG_SIGNED_INT); ct_test(pTest, decode_is_context_specific(&apdu[0]) == false); value = value << 1; } value = -1; apdu_len = encode_tagged_signed(&array[0], value); len = decode_tag_number_and_value(&array[0], &tag_number, &len_value); len += decode_signed(&array[len], len_value, &decoded_value); ct_test(pTest, len == apdu_len); ct_test(pTest, decoded_value == value); encode_tagged_signed(&encoded_array[0], decoded_value); ct_test(pTest, memcmp(&array[0], &encoded_array[0], sizeof(array)) == 0); // a signed int will take up to 4 octects // plus a one octet for the tag apdu_len = encode_tagged_signed(&apdu[0], value); len = decode_tag_number_and_value(&apdu[0], &tag_number, NULL); ct_test(pTest, len == 1); ct_test(pTest, tag_number == BACNET_APPLICATION_TAG_SIGNED_INT); ct_test(pTest, decode_is_context_specific(&apdu[0]) == false); return; } void testBACDCodeString(Test * pTest) { uint8_t array[MAX_APDU] = { 0 }; uint8_t encoded_array[MAX_APDU] = { 0 }; char test_string[MAX_APDU] = { "" }; char decoded_string[MAX_APDU] = { "" }; int i; // for loop counter int apdu_len; int len; char *test_string0 = ""; uint8_t tag_number = 0; uint32_t len_value = 0; apdu_len = encode_tagged_character_string(&array[0], &test_string0[0]); len = decode_tag_number_and_value(&array[0], &tag_number, &len_value); len += decode_character_string(&array[len], len_value, &decoded_string[0], sizeof(decoded_string)); ct_test(pTest, apdu_len == len); ct_test(pTest, strcmp(&test_string0[0], &decoded_string[0]) == 0); for (i = 0; i < (MAX_APDU - 6); i++) { test_string[i] = 'S'; test_string[i + 1] = '\0'; apdu_len = encode_tagged_character_string(&encoded_array[0], &test_string[0]); len = decode_tag_number_and_value(&encoded_array[0], &tag_number, &len_value); len += decode_character_string(&encoded_array[len], len_value, &decoded_string[0], sizeof(decoded_string)); if (apdu_len != len) { printf("test string=#%d\n", i); } ct_test(pTest, apdu_len == len); if (strcmp(&test_string[0], &decoded_string[0]) != 0) { printf("test string=#%d\n", i); } ct_test(pTest, strcmp(&test_string[0], &decoded_string[0]) == 0); } return; } void testBACDCodeObject(Test * pTest) { uint8_t object_array[4] = { 0 }; uint8_t encoded_array[4] = { 0 }; BACNET_OBJECT_TYPE type = OBJECT_BINARY_INPUT; BACNET_OBJECT_TYPE decoded_type = OBJECT_ANALOG_OUTPUT; int instance = 123; uint32_t decoded_instance = 0; encode_bacnet_object_id(&encoded_array[0], type, instance); decode_object_id(&encoded_array[0], (int *) &decoded_type, &decoded_instance); ct_test(pTest, decoded_type == type); ct_test(pTest, decoded_instance == instance); encode_bacnet_object_id(&object_array[0], type, instance); ct_test(pTest, memcmp(&object_array[0], &encoded_array[0], sizeof(object_array)) == 0); for (type = 0; type < 1024; type++) { for (instance = 0; instance <= BACNET_MAX_INSTANCE; instance += 1024) { encode_bacnet_object_id(&encoded_array[0], type, instance); decode_object_id(&encoded_array[0], (int *) &decoded_type, &decoded_instance); ct_test(pTest, decoded_type == type); ct_test(pTest, decoded_instance == instance); encode_bacnet_object_id(&object_array[0], type, instance); ct_test(pTest, memcmp(&object_array[0], &encoded_array[0], sizeof(object_array)) == 0); } } return; } void testBACDCodeMaxSegsApdu(Test * pTest) { int max_segs[8] = {0,2,4,8,16,32,64,65}; int max_apdu[6] = {50,128,206,480,1024,1476}; int i = 0; int j = 0; uint8_t octet = 0; // test for (i = 0; i < 8; i++) { for (j = 0; j < 6; j++) { octet = encode_max_segs_max_apdu(max_segs[i], max_apdu[j]); ct_test(pTest, max_segs[i] == decode_max_segs(octet)); ct_test(pTest, max_apdu[j] == decode_max_apdu(octet)); } } } void testBACDCodeBitString(Test * pTest) { uint8_t bit = 0; BACNET_BIT_STRING bit_string; BACNET_BIT_STRING decoded_bit_string; uint8_t apdu[MAX_APDU] = { 0 }; uint32_t len_value = 0; uint8_t tag_number = 0; int len = 0; bitstring_init(&bit_string); // verify initialization ct_test(pTest, bitstring_bits_used(&bit_string) == 0); for (bit = 0; bit < (MAX_BITSTRING_BYTES*8); bit++) { ct_test(pTest, bitstring_bit(&bit_string, bit) == false); } // test encode/decode -- true for (bit = 0; bit < (MAX_BITSTRING_BYTES*8); bit++) { bitstring_set_bit(&bit_string, bit, true); ct_test(pTest, bitstring_bits_used(&bit_string) == (bit + 1)); ct_test(pTest, bitstring_bit(&bit_string, bit) == true); // encode len = encode_tagged_bitstring(&apdu[0], &bit_string); // decode len = decode_tag_number_and_value(&apdu[0], &tag_number, &len_value); ct_test(pTest, tag_number == BACNET_APPLICATION_TAG_BIT_STRING); len += decode_bitstring(&apdu[len], len_value,&decoded_bit_string); ct_test(pTest, bitstring_bits_used(&decoded_bit_string) == (bit + 1)); ct_test(pTest, bitstring_bit(&decoded_bit_string, bit) == true); } // test encode/decode -- false bitstring_init(&bit_string); for (bit = 0; bit < (MAX_BITSTRING_BYTES*8); bit++) { bitstring_set_bit(&bit_string, bit, false); ct_test(pTest, bitstring_bits_used(&bit_string) == (bit + 1)); ct_test(pTest, bitstring_bit(&bit_string, bit) == false); // encode len = encode_tagged_bitstring(&apdu[0], &bit_string); // decode len = decode_tag_number_and_value(&apdu[0], &tag_number, &len_value); ct_test(pTest, tag_number == BACNET_APPLICATION_TAG_BIT_STRING); len += decode_bitstring(&apdu[len], len_value,&decoded_bit_string); ct_test(pTest, bitstring_bits_used(&decoded_bit_string) == (bit + 1)); ct_test(pTest, bitstring_bit(&decoded_bit_string, bit) == false); } } #ifdef TEST_DECODE int main(void) { Test *pTest; bool rc; pTest = ct_create("BACDCode", NULL); /* individual tests */ rc = ct_addTestFunction(pTest, testBACDCodeTags); assert(rc); rc = ct_addTestFunction(pTest, testBACDCodeReal); assert(rc); rc = ct_addTestFunction(pTest, testBACDCodeUnsigned); assert(rc); rc = ct_addTestFunction(pTest, testBACDCodeSigned); assert(rc); rc = ct_addTestFunction(pTest, testBACDCodeEnumerated); assert(rc); rc = ct_addTestFunction(pTest, testBACDCodeString); assert(rc); rc = ct_addTestFunction(pTest, testBACDCodeObject); assert(rc); rc = ct_addTestFunction(pTest, testBACDCodeMaxSegsApdu); assert(rc); rc = ct_addTestFunction(pTest, testBACDCodeBitString); assert(rc); // configure output ct_setStream(pTest, stdout); ct_run(pTest); (void) ct_report(pTest); ct_destroy(pTest); return 0; } #endif /* TEST_DECODE */ #endif /* TEST */