pv: add s.escape.csv transformation

escapes a string to use as a CSV field, as specified in RFC4180:
- enclose sting in double quotes
- escape double quotes with a second double quote

lib/kcore/strcommon.c

@@ -373,3 +373,32 @@ int escape_param(str *sin, str *sout)
     return 0;
 }
 
+/*! \brief
+ * escapes a string to use as a CSV field, as specified in RFC4180:
+ * - enclose sting in double quotes
+ * - escape double quotes with a second double quote
+ */
+int escape_csv(str *sin, str *sout)
+{
+    char *at, *p;
+
+    if (sin==NULL || sout==NULL || sin->s==NULL || sout->s==NULL ||
+        sin->len<0 || sout->len < 2*sin->len+3)
+        return -1;
+
+    at = sout->s;
+    p  = sin->s;
+    *at++ = '"';
+    while (p < sin->s+sin->len) {
+		if(*p == '"') {
+			*at++ = '"';
+		}
+        *at++ = *p++;
+    }
+    *at++ = '"';
+    *at = 0;
+    sout->len = at - sout->s;
+    LM_DBG("escaped string is <%s>\n", sout->s);
+
+    return 0;
+}

lib/kcore/strcommon.h

@@ -46,5 +46,7 @@ int escape_param(str *sin, str *sout);
 
 int unescape_param(str *sin, str *sout);
 
+int escape_csv(str *sin, str *sout);
+
 #endif
 

modules/pv/pv_trans.c

@@ -514,6 +514,17 @@ int tr_eval_string(struct sip_msg *msg, tr_param_t *tp, int subtype,
 			val->flags = PV_VAL_STR;
 			val->rs = st;
 			break;
+		case TR_S_ESCAPECSV:
+			if(!(val->flags&PV_VAL_STR))
+				val->rs.s = int2str(val->ri, &val->rs.len);
+			st.s = _tr_buffer;
+			st.len = TR_BUFFER_SIZE;
+			if (escape_csv(&val->rs, &st))
+				return -1;
+			memset(val, 0, sizeof(pv_value_t));
+			val->flags = PV_VAL_STR;
+			val->rs = st;
+			break;
 		case TR_S_SUBSTR:
 			if(tp==NULL || tp->next==NULL)
 			{
@@ -2093,6 +2104,9 @@ char* tr_parse_string(str* in, trans_t *t)
 	} else if(name.len==14 && strncasecmp(name.s, "unescape.param", 14)==0) {
 		t->subtype = TR_S_UNESCAPEPARAM;
 		goto done;
+	} else if(name.len==10 && strncasecmp(name.s, "escape.csv", 10)==0) {
+		t->subtype = TR_S_ESCAPECSV;
+		goto done;
 	} else if(name.len==8 && strncasecmp(name.s, "prefixes", 8)==0) {
 		t->subtype = TR_S_PREFIXES;
 		if(*p!=TR_PARAM_MARKER)

modules/pv/pv_trans.h

@@ -40,7 +40,7 @@ enum _tr_s_subtype {
 	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,
 	TR_S_TIMEFORMAT, TR_S_TRIM, TR_S_RTRIM, TR_S_LTRIM, TR_S_RM, TR_S_STRIPTO,
-	TR_S_URLENCODEPARAM, TR_S_URLDECODEPARAM, TR_S_NUMERIC
+	TR_S_URLENCODEPARAM, TR_S_URLDECODEPARAM, TR_S_NUMERIC, TR_S_ESCAPECSV
 };
 enum _tr_uri_subtype {
 	TR_URI_NONE=0, TR_URI_USER, TR_URI_HOST, TR_URI_PASSWD, TR_URI_PORT,