(local fcntl (require "posix.fcntl")) (local posix (require "posix")) (local { : read : write } (require "posix.unistd")) (local {: tcgetattr : tcsetattr : tcdrain : CLOCAL : CREAD : ICANON : ECHO : ECHOE : ISIG : OPOST } (require "posix.termio")) (local { : nanosleep } (require "posix.time")) (local { : view } (require "fennel")) (local gsm-char (require :unicode-to-gsm)) (macro test= [expr expected] `(let [a# ,expr e# ,expected] (if (not (= a# e#)) (assert false (.. "expected " ,(view expr) " = " e# ", actual " a#))))) (fn escape-readably [s] (s:gsub "%c" (fn [x] (string.format "\\u{%.3x}" (string.byte x))))) (fn log-xfer [direction message] (when _G.modem-spew (_G.modem-spew:write direction " " (escape-readably message) "\n")) message) (fn tx [fd s] (write fd s) (log-xfer :>>> s) (nanosleep {:tv_sec 0 :tv_nsec (* 10 1000 1000)})) (fn chars [i] (if (not i) "" (< i 256) (string.char i) (.. (string.char (rshift i 8)) (string.char (band i 0xff))))) (fn unicode->gsm [s] (s:gsub "." (fn [c] (chars (. gsm-char (string.byte c)))))) (test= (unicode->gsm "abc123") "abc123") (test= (unicode->gsm "abc{123}") "abc\x1b(123\x1b)") (fn expect [fd pattern fail-pattern] (let [b (read fd 1024)] (if (> (# b) 0) (if (string.find (log-xfer :<<< b) pattern) (log-xfer :!!! pattern) (and fail-pattern (string.find b fail-pattern)) (error (.. "Expected " pattern ", got " (escape-readably b))) (expect fd pattern fail-pattern)) nil))) (fn command [fd s] (tx fd (.. s "\r\n")) (expect fd "OK" "ERROR")) (fn even? [x] (= (% x 2) 0)) (fn phone-number->hex [number] (let [n (if (even? (# number)) number (.. number "F"))] (n:gsub ".." (fn [s] (.. (s:sub 2 2) (s:sub 1 1)))))) (test= (phone-number->hex "85291234567") "5892214365F7") (test= (phone-number->hex "447785016005") "447758100650") (fn bit-range [i start end] (let [width (+ 1 (- end start)) mask (lshift (rshift 0xff (- 8 width)) start)] (rshift (band i mask) start))) (fn septets->hex [body] ;; 0 body0[0-6] | body1[0] << 7 ;; 1 body1[1-6] | body2[0-1] << 6 ;; 2 body2[2-6] | body3[0-2] << 5 ;; 3 body3[3-6] | body4[0-3] << 4 ;; 4 body4[4-6] | body5[0-4] << 3 ;; 5 body5[5-6] | body6[0-5] << 2 ;; 6 body6[6] | body7[0-6] << 1 ;; 7 body8[0-6] | body9[0] << 7 ;; 8 body9[1-6] | body10[0-1] << 6 ;; 14 body16[0-6] | body17[0] << 7 ;; for n<7, ;; nth byte is bits n..6 of nth septet, ;; and bits 0..n of(n+1)th septet ;; for all n including n>=7, ;; bits n%7..6 of floor(n+ (n/7))th septet ;; and 0..(n%7) of the next one (let [bytes (math.floor (/ (* 7 (# body)) 8)) padded (.. body "\0")] (var out "") (for [index 0 bytes] (let [n (% index 7) in-index (math.floor (+ index (/ index 7))) one (bit-range (string.byte padded (+ 1 in-index)) n 6) two (bit-range (string.byte padded (+ 2 in-index)) 0 n)] (set out (string.format "%s%.2X" out (bor one (lshift two (- 7 n) ) ))))) out)) (fn message->pdu [destination-number body] ;; expects destination-number to be international but no leading + ;; body is in gsm 7 bit alphabet (let [fields [ ;; sms-submit, allow dups, no vaidity period, no rpely path, no udh, ;; no reply=path "01" ;; ME can choose message reference number "00" (string.format "%.2X" (# destination-number)) ;; destination-number is international (ITU E.164/E.163) without leading + "91" (phone-number->hex destination-number) ;; protocol identifier "00" ;; data coding scheme (GSM 7 bit default alphabet) "00" (string.format "%.2X" (# body)) (septets->hex body) ]] (table.concat fields))) ;; per worked example at https://www.developershome.com/sms/cmgsCommand4.asp (test= (message->pdu "85291234567" "It is easy to send text messages.") "01000B915892214365F7000021493A283D0795C3F33C88FE06CDCB6E32885EC6D341EDF27C1E3E97E72E") (fn send-message [{: fd} number body] (let [pdu (message->pdu number (unicode->gsm body)) payload (.. "00" pdu)] (doto fd (tx (.. "AT+CMGS=" (string.format "%d" (/ (# pdu) 2)) "\r\n")) (expect ">" "ERROR") (tx payload) (tx "\026") (expect "OK")))) (fn new-sender [{: device : smsc : verbose}] (let [fd (fcntl.open device posix.O_RDWR) termios (tcgetattr fd)] (tset termios :cflag (bor termios.cflag CLOCAL CREAD)) (tset termios :lflag (band termios.lflag (bnot ICANON) (bnot ECHO) (bnot ECHOE) (bnot ISIG))) (tset termios :oflag (band termios.oflag ( bnot OPOST))) (doto fd (tcsetattr 0 termios) (tcdrain) (command "AT") ; hello ? (command "AT&F") ; revert to defaults (command "ATE0") ; disable command echo (command "AT+CMEE=1") ; print CME errors (command (.. "AT+CSCA=\"" smsc "\",145")) ; set SMSC (command "AT+CMGF=0")) ; expect SMS data in PDU mode {:send send-message :device device :smsc smsc :fd fd})) { :new new-sender :verbose false }