fix link parsing

This fixes an issue with how the bbslink sync process was handling incoming posts. It was not removing the @fromNode from the end of the body, which was causing it to get appended again during the push process. This would compound with more nodes involved in the sync process

alt to https://github.com/SpudGunMan/meshing-around/pull/296

Co-Authored-By: Amy Nagle <1270500+kabili207@users.noreply.github.com>

modules/bbstools.py

@@ -255,7 +255,19 @@ def bbs_sync_posts(input, peerNode, RxNode):
             #store the message
             subject = input.split("$")[1].split("#")[0]
             body = input.split("#")[1]
-            fromNodeHex = input.split("@")[1]
+            fromNodeHex = body.split("@")[1]
+            #validate the fromNodeHex is a valid hex number
+            try:
+                int(fromNodeHex, 16)
+            except ValueError:
+                logger.error(f"System: Invalid fromNodeHex in bbslink from node {peerNode}: {input}")
+                fromNodeHex = hex(peerNode)
+            #validate the subject and body are not empty
+            if subject.strip() == "" or body.strip() == "":
+                logger.error(f"System: Empty subject or body in bbslink from node {peerNode}: {input}")
+                return "System: Invalid bbslink format."
+            
+            #store the message in the bbsdb
             try:
                 bbs_post_message(subject, body, int(fromNodeHex, 16))
             except: