Changed: change SCID via env variable

Cann now read and change SCID via env variable LSQUIC_CID. Format is a string of up to 20 space separated numbers which are then parsed. Relies on atoi, so be careful with invalid values for the numbers

src/liblsquic/lsquic_conn.c

@@ -21,6 +21,9 @@
 
 #include "lsquic_logger.h"
 
+
+#include <stdio.h>
+#include <stdlib.h>
 int lsquic_random_cid = 0;
 
 const lsquic_cid_t *
@@ -259,9 +262,29 @@ lsquic_generate_cid (lsquic_cid_t *cid, size_t len) {
 //           cid->len = 8;
 //       }
     } else {
-        if (!len) {
+        const char* s = getenv("LSQUIC_CID");
+        if (s!=NULL) {
+            char  tmpStrings[20][20];
+            int wordctr, i, j = 0;
+            for (i=0; s[i] != '\0' && wordctr < 20; i++) {
+                if (s[i] == ' ' || s[i] == '\0') {
+                    tmpStrings[wordctr][j] = '\0';
+                    wordctr++;
+                    j=0;
+                } else {
+                    tmpStrings[wordctr][j] = s[i];
+                    j++;
+                }
+            }
+            for(i = 0; i <= wordctr; i++) {
+                cid->idbuf[i] = (uint8_t)atoi(tmpStrings[i]);
+            }
+            cid->len= wordctr < 8?8:wordctr;
+            
+        }
+        else if (!len) {
             /* If not set, generate ID for Destination and set len to 8 */
-            *cid->idbuf = 2;
+            *cid->idbuf=2;
             cid->len = 8;
         } else {
             /* generate ID for Source */