[sr-dev] git:master: modules/pv: Add 7Bit Encoding/Decoding (e.g. for 3GPP-SMS)

[Carsten Bock]

Module: sip-router
Branch: master
Commit: 9b11c8362a0b07cb3fc8779582a92cdc56c07752
URL:    http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=9b11c8362a0b07cb3fc8779582a92cdc56c07752

Author: Carsten Bock <carsten at ng-voice.com>
Committer: Carsten Bock <carsten at ng-voice.com>
Date:   Thu Oct 16 20:58:28 2014 +0200

modules/pv: Add 7Bit Encoding/Decoding (e.g. for 3GPP-SMS)

---

 modules/pv/pv_trans.c |   84 +++++++++++++++++++++++++++++++++++++++++++++++++
 modules/pv/pv_trans.h |    2 +-
 2 files changed, 85 insertions(+), 1 deletions(-)

diff --git a/modules/pv/pv_trans.c b/modules/pv/pv_trans.c
index 96516f5..5c476b3 100644
--- a/modules/pv/pv_trans.c
+++ b/modules/pv/pv_trans.c
@@ -179,6 +179,62 @@ static int urldecode_param(str *sin, str *sout) {
 	return 0;
 }
 
+/* Encode 7BIT PDU */
+static int pdu_7bit_encode(str sin) {
+	int i, j;
+	unsigned char hex;
+	unsigned char nleft;
+	unsigned char fill;
+	char HexTbl[] = {"0123456789ABCDEF"};
+
+	nleft = 1;
+	j = 0;
+	for(i = 0; i < sin.len; i++) {
+		hex = *(sin.s) >> (nleft - 1);
+		fill = *(sin.s+1) << (8-nleft);
+		hex = hex | fill;
+		_tr_buffer[j++] = HexTbl[hex >> 4];
+		_tr_buffer[j++] = HexTbl[hex & 0x0F];
+		nleft++;
+		if(nleft == 8) {
+			sin.s++;
+			i++;
+			nleft = 1;
+		}	   										 	
+		sin.s++;
+	}
+	_tr_buffer[j] = '\0';
+	return j;
+}
+
+/* Decode 7BIT PDU */
+static int pdu_7bit_decode(str sin) {
+	int i, j;
+	unsigned char nleft = 1;
+	unsigned char fill = 0;
+	unsigned char oldfill = 0;
+	j = 0;
+	for(i = 0; i < sin.len; i += 2) {
+		_tr_buffer[j] = (unsigned char)pv_from_hex(sin.s[i]) << 4;
+		_tr_buffer[j] |= (unsigned char)pv_from_hex(sin.s[i+1]);
+		fill = (unsigned char)_tr_buffer[j];
+		fill >>= (8 - nleft);
+		_tr_buffer[j] <<= (nleft -1 );
+		_tr_buffer[j] &= 0x7F;
+		_tr_buffer[j] |= oldfill;
+		oldfill = fill;
+		j++;
+		nleft++;
+		if(nleft == 8) {
+			_tr_buffer[j++] = oldfill;
+			nleft = 1;
+			oldfill = 0;
+		}
+	}
+	_tr_buffer[j] = '\0';
+	return j;	
+}
+
 /* -- transformations functions */
 
 /*!
@@ -312,6 +368,28 @@ int tr_eval_string(struct sip_msg *msg, tr_param_t *tp, int subtype,
 			val->rs.s = _tr_buffer;
 			val->rs.len = i;
 			break;
+		case TR_S_ENCODE7BIT:
+			if(!(val->flags&PV_VAL_STR))
+				val->rs.s = int2str(val->ri, &val->rs.len);
+			if(val->rs.len > (TR_BUFFER_SIZE*7/8) -1)
+				return -1;
+			i = pdu_7bit_encode(val->rs);
+			memset(val, 0, sizeof(pv_value_t));
+			val->flags = PV_VAL_STR;
+			val->rs.s = _tr_buffer;
+			val->rs.len = i;
+			break;
+		case TR_S_DECODE7BIT:
+			if(!(val->flags&PV_VAL_STR))
+				val->rs.s = int2str(val->ri, &val->rs.len);
+			if(val->rs.len>TR_BUFFER_SIZE/2-1)
+				return -1;
+			i = pdu_7bit_decode(val->rs);
+			memset(val, 0, sizeof(pv_value_t));
+			val->flags = PV_VAL_STR;
+			val->rs.s = _tr_buffer;
+			val->rs.len = i;
+			break;
 		case TR_S_ENCODEBASE64:
 			if(!(val->flags&PV_VAL_STR))
 				val->rs.s = int2str(val->ri, &val->rs.len);
@@ -1960,6 +2038,12 @@ char* tr_parse_string(str* in, trans_t *t)
 	} else if(name.len==11 && strncasecmp(name.s, "decode.hexa", 11)==0) {
 		t->subtype = TR_S_DECODEHEXA;
 		goto done;
+	} else if(name.len==11 && strncasecmp(name.s, "encode.7bit", 11)==0) {
+		t->subtype = TR_S_ENCODE7BIT;
+		goto done;
+	} else if(name.len==11 && strncasecmp(name.s, "decode.7bit", 11)==0) {
+		t->subtype = TR_S_DECODE7BIT;
+		goto done;
 	} else if(name.len==13 && strncasecmp(name.s, "encode.base64", 13)==0) {
 		t->subtype = TR_S_ENCODEBASE64;
 		goto done;
diff --git a/modules/pv/pv_trans.h b/modules/pv/pv_trans.h
index 346fd32..be3c7ac 100644
--- a/modules/pv/pv_trans.h
+++ b/modules/pv/pv_trans.h
@@ -37,7 +37,7 @@ enum _tr_type { TR_NONE=0, TR_STRING, TR_URI, TR_PARAMLIST, TR_NAMEADDR,
 enum _tr_s_subtype { 
 	TR_S_NONE=0, TR_S_LEN, TR_S_INT, TR_S_MD5, TR_S_SHA256, TR_S_SHA384,
 	TR_S_SHA512, TR_S_SUBSTR, TR_S_SELECT, TR_S_ENCODEHEXA, TR_S_DECODEHEXA,
-	TR_S_ENCODEBASE64, TR_S_DECODEBASE64,
+	TR_S_ENCODE7BIT, TR_S_DECODE7BIT, TR_S_ENCODEBASE64, TR_S_DECODEBASE64,
 	TR_S_ESCAPECOMMON, TR_S_UNESCAPECOMMON, TR_S_ESCAPEUSER, TR_S_UNESCAPEUSER,
 	TR_S_ESCAPEPARAM, TR_S_UNESCAPEPARAM, TR_S_TOLOWER, TR_S_TOUPPER,
 	TR_S_STRIP, TR_S_STRIPTAIL, TR_S_PREFIXES, TR_S_PREFIXES_QUOT, TR_S_REPLACE,