Log-shipping : Broken Chain
If you are saying your actual backup file is corrupted (the .trn file) but that the backup was successful from SQL Server's perspective, and the source DB is still online, I would take a full backup as soon as possible so you don't lose any data. 

You will have to rebuild your log shipping if you've got a corrupt .trn, but your main concern should be having the ability to restore your source data at all if you've got a bad .trn in your chain.