Bug 876489 - Signaling fix ccprovider::getDigits r=jesup

media/webrtc/signaling/src/sipcc/core/ccapp/ccprovider.c

@@ -581,9 +581,9 @@ static void updateVideoPref( unsigned int event, line_t line_id, callid_t call_i
  *    digits - memory to return the first param
  *  Returns:
  */
-void getDigits(string_t data, char *digits) {
+static void getDigits(string_t data, char *digits, unsigned int buffer_length) {
    char *endptr;
-   int len=0;
+   unsigned int len=0;
 
    digits[0]=0;
 
@@ -595,6 +595,11 @@ void getDigits(string_t data, char *digits) {
            len = strlen(data);
        }
 
+       /* prevent len from writing past buffer size */
+       if (len >= buffer_length) {
+        len = buffer_length - 1;
+       }
+
        if ( len) {
            memcpy(digits, data, len);
            digits[len] = 0;
@@ -692,7 +697,7 @@ processSessionEvent (line_t line_id, callid_t call_id, unsigned int event, sdp_d
            break;
          case CC_FEATURE_DIALSTR:
              if (CheckAndGetAvailableLine(&line_id, &call_id) == TRUE) {
-                 getDigits(data, digits);
+                 getDigits(data, digits, sizeof(digits));
                  if (strlen(digits) == 0) {
                     //if dial string is empty then go offhook
                     cc_offhook(CC_SRC_UI, call_id, line_id);
@@ -779,7 +784,7 @@ processSessionEvent (line_t line_id, callid_t call_id, unsigned int event, sdp_d
                  break;
              }
 
-             getDigits(data,digits);
+             getDigits(data, digits, sizeof(digits));
 
              dp_int_init_dialing_data(line_id, call_id);
              dp_int_dial_immediate(line_id, call_id, TRUE,
@@ -890,7 +895,7 @@ processSessionEvent (line_t line_id, callid_t call_id, unsigned int event, sdp_d
 		     }// DON'T ADD BREAK HERE. EVENT IS PASSED BELOW
 	 case CC_FEATURE_B2BCONF:
 	 case CC_FEATURE_XFER:
-		     getDigits(data,digits);
+		     getDigits(data, digits, sizeof(digits));
 		     if ( strlen(digits)) {
 			cc_feature_data_t ftr_data;
 			CCAPP_DEBUG(DEB_F_PREFIX"conf: sid=%s.", DEB_F_PREFIX_ARGS(SIP_CC_PROV, fname),data);