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Diffstat (limited to 'ebus-racket/ebus/layer7.rkt')
| -rw-r--r-- | ebus-racket/ebus/layer7.rkt | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/ebus-racket/ebus/layer7.rkt b/ebus-racket/ebus/layer7.rkt new file mode 100644 index 0000000..3bcad01 --- /dev/null +++ b/ebus-racket/ebus/layer7.rkt @@ -0,0 +1,166 @@ +#lang racket/base +(require racket/list + (planet lizorkin/sxml:2:1/sxml) + (planet lizorkin/ssax:2:0/ssax) + "layer2.rkt") + +(define logger (make-logger 'ebus-layer7 (current-logger))) + +(define definition + (ssax:xml->sxml (open-input-file "../ebus-xml/ebus.xml") + '[(#f . "http://xapek.org/ebus/0.1")])) + +(define (paket ebus-paket) + (define primaryCommand (layer2-ebus-paket-primaryCommand ebus-paket)) + (define secondaryCommand (layer2-ebus-paket-secondaryCommand ebus-paket)) + ((sxpath (string-append "//packet[@primary=" (number->string primaryCommand) + " and @secondary=" (number->string secondaryCommand) "]")) + definition)) + +;; returns the full device-definition +(define (device address) + ((sxpath (string-append "//devices/device[@address=" (number->string address) "]")) + definition)) + +;; returns device-name in a list or empty-list +(define (device-name address) + (first ((sxpath "@name/text()") (device address)))) + + +(define (paket-fields ebus-paket) + (define paket-definition (paket ebus-paket)) + (cond ((> (length paket-definition) 0) + (let* + ([paket-name (string-append + (device-name (layer2-ebus-paket-source ebus-paket)) + "." + (first ((sxpath "@name/text()") paket-definition)))] + [fields ((sxpath "fields/*") paket-definition)] + [values + (for/list ([field fields]) (paket-fields-dispatch-decoder ebus-paket field paket-name))]) + ;; filter invalid values + (for/list ([value values] #:when (not (void? value))) + value))) + (else (void (log-message logger 'warning (format "Unknown Paket: ~s" ebus-paket) #t))))) + +(define (paket-fields-dispatch-decoder ebus-paket field paket-name) + (define datatype ((sxpath "name()") field)) + (define name (string-append paket-name "." (first ((sxpath "@name/text()") field)))) + (define offset (string->number (first ((sxpath "@offset/text()") field)))) + (define payload (layer2-ebus-paket-payload ebus-paket)) + (cond ((string=? "bit" datatype) + (list name datatype offset + (field-decoder-bit (list-ref payload offset)))) + ((string=? "bcd" datatype) + (list name datatype offset + (field-decoder-bcd (list-ref payload offset)))) + ((string=? "data1b" datatype) + (list name datatype offset + (field-decoder-data1b (list-ref payload offset)))) + ((string=? "data1c" datatype) + (list name datatype offset + (field-decoder-data1c (list-ref (layer2-ebus-paket-payload ebus-paket) offset)))) + ((string=? "byte" datatype) + (list name datatype offset (list-ref payload offset))) + ((string=? "data2b" datatype) + (list name datatype offset + (field-decoder-data2b (list-ref payload offset) + (list-ref payload (+ offset 1))))) + ((string=? "data2c" datatype) + (list name datatype offset + (field-decoder-data2c (list-ref payload offset) + (list-ref payload (+ offset 1))))) + ((string=? "word" datatype) + (list name datatype offset + (field-decoder-word (list-ref payload offset) + (list-ref payload (+ offset 1))))) + ((string=? "byteEnum" datatype) + (list name datatype offset + (field-decoder-byteEnum (list-ref payload offset) field))) + (else (void (log-message logger 'error (format "unknown datatype: ~a" datatype) #t))))) + +;; type bit +(define (field-decoder-bit value) + (cond ((= value 1) 1) + (else 0))) + +;; type data1b +(define (field-decoder-data1b value) + value) + +;; type data1c +(define (field-decoder-data1c value) + (/ value 2.0)) + +;; type data2b +(define (field-decoder-data2b lowByte highByte) + (if (= (bitwise-and highByte 128) 128) + (* -1 + (+ (+ 256 (bitwise-not highByte)) + (/ (+ 256 (bitwise-not (+ lowByte 1))) 256.0))) + (+ highByte (/ lowByte 256.0)))) + + ;; type data2c + ;; Beispiel für die Berechnung: + ;; if ((x & 8000h) == 8000h) // y negativ + ;; y = - [dez(High_Byte(!x)) 16 + dez(High_Nibble (Low_Byte (!x))) + ;; + (dez(Low_Nibble (Low_Byte (!x))) +1 ) / 16] + ;; else // y positiv + ;; y = dez(High_Byte(x)) 16 + dez(High_ Nibble (Low Byte (x))) + ;; + dez(Low_ Nibble (Low Byte (x))) / 16 +(define (field-decoder-data2c lowByte highByte) + (define (lowNibble v) + (bitwise-and v #x0f)) + (define (highNibble v) + (arithmetic-shift v -4)) + (define (u-not v) + (+ 256 (bitwise-not v))) + (if (= (bitwise-and highByte 128) 128) + (* -1 + (+ (arithmetic-shift (u-not highByte) 4) + (highNibble (u-not lowByte)) + (/ (+ (lowNibble (u-not lowByte)) 1) + 16.0))) + (+ (arithmetic-shift highByte 4) + (highNibble lowByte) + (/ + (lowNibble lowByte) + 16)))) + +;; type byteEnum +(define (field-decoder-byteEnum value field-definition) + (define (pred l) + (= value (list-ref l 0))) + (define all-options (for/list ([option ((sxpath "option") field-definition)]) + (list (string->number (first ((sxpath "@value/text()") option))) ;; value, name + (first ((sxpath "@name/text()") option))))) + (define options (filter pred all-options)) + (cond ((= (length options) 1) + (list-ref (first options) 1)) + (else "<undefined>"))) + +;; type word +(define (field-decoder-word lowByte highByte) + (+ lowByte + (arithmetic-shift highByte 8))) + +;; type bcd +(define (field-decoder-bcd value) + (+ (bitwise-and value #x0f) + (arithmetic-shift value -4))) + +;; read one ebus-paket or eof from input-port +;; or return #<eof> +(define (read-ebus input-port) + (define paket (layer2-read-ebus input-port)) + (cond ((layer2-ebus-paket? paket) + (paket-fields paket)) + (else paket))) + +(provide (prefix-out layer7- paket) + (prefix-out layer7- paket-fields) + (prefix-out layer7- device) + (prefix-out layer7- device-name) + ;; read ebus from port an return fields from next paket + (prefix-out layer7- read-ebus) + (prefix-out layer7- logger)) |