commit b2c4972529b124f95c6a9fe6fe45bb87963d2d08
parent 4ca8ddcf9fed51d399ad5f41d3b8ec3bedc619ec
Author: Daniel Barlow <dan@telent.net>
Date: Fri, 16 Sep 2022 00:30:54 +0100
switch to using PDU format
this means we can now send { } [ ] and other characters that
have multi-byte encoding in the gsm character set
Diffstat:
| M | sms.fnl | | | 119 | ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------------- |
1 file changed, 100 insertions(+), 19 deletions(-)
diff --git a/sms.fnl b/sms.fnl
@@ -26,13 +26,12 @@
(string.char i)
(.. (string.char (rshift i 8)) (string.char (band i 0xff)))))
-(fn unicode-to-gsm [s]
+(fn unicode->gsm [s]
(s:gsub "." (fn [c] (chars (. gsm-char (string.byte c))))))
;(print (escape-for-logging (unicode-to-gsm "hello")))
;(print (escape-for-logging (unicode-to-gsm "{he@llo}€")))
-
(fn expect [fd pattern fail-pattern]
(let [b (read fd 1024)]
(if (> (# b) 0)
@@ -45,6 +44,88 @@
(expect fd pattern)))
nil)))
+(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))))))
+
+(assert (= (phone-number->hex "447000123456") "440700214365"))
+(assert (= (phone-number->hex "85291234567") "5892214365F7"))
+
+(fn mask [start end]
+ (let [width (+ 1 (- end start))]
+ (lshift (rshift 0xff (- 8 width)) start)))
+
+(fn bit-range [i start end]
+ (rshift (band i (mask start end)) 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 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
+
+(assert (= (message->pdu "85291234567" "It is easy to send text messages.") "01000B915892214365F7000021493A283D0795C3F33C88FE06CDCB6E32885EC6D341EDF27C1E3E97E72E"))
+
+
(fn command [fd s]
(tx fd (.. s "\r\n"))
(expect fd "OK" "ERROR"))
@@ -62,23 +143,23 @@
(tcsetattr fd 0 termios)
(tcdrain fd)
- (doto fd
- (command "AT")
- (command "AT&F") ; revert to defaults
- (command "ATE0") ; disable command echo
- (command "AT+CMEE=1") ;print CME errors
- (command "AT+CMGF=1") ;SMS text mode (vs. PDU mode)
- (command "AT+CSCS=\"GSM\"") ; default character set
- (command "AT+CSMP=17,12,0,0") ; message valid for 12*5 minutes
- (command "AT+CSCA=\"+447958879879\",145\r\n") ;set SMSC
-
- (tx (.. "AT+CMGS=\"" number "\"\r\n"))
- (expect ">")
-
- ;; (tx (unicode-to-gsm body))
- (tx body)
- (tx "\026\r\n")
- (expect "OK"))))
+ (let [pdu (message->pdu number (unicode->gsm body))
+ payload (.. "00" pdu)]
+ (doto fd
+ (command "AT")
+ (command "AT&F") ; revert to defaults
+ (command "ATE0") ; disable command echo
+ (command "AT+CMEE=1") ;print CME errors
+ (command "AT+CSCA=\"+447958879879\",145\r\n") ;set SMSC
+ (command "AT+CMGF=0") ;SMS PDU mode
+
+ (tx (.. "AT+CMGS=" (string.format "%d" (/ (# pdu) 2)) "\r\n"))
+ (expect ">" "ERROR")
+ (tx payload)
+ (tx "\026\r\n")
+ (expect "OK")))))
+
+;(send-sms "447000123456" "It is never {easy} to [send] text messages.")
{ :send send-sms }
