Here is a study guide to The Curious Incident of the Dog in the Night-Time including notes by the author Mark Haddon. My year 12's liked the novel. thebestnotes.com/.../Curious_Incident_Dog_Night_Time.../Curious_Incident_Study_Guide01.html

いったいっていう感じ There are many in English: What the hell are you doing? What in God's name are you doing? What the fuck are you doing? What in fuck's name are you doing? The stronger the word, the stronger the expression.

It is an offensive term meaning "What in the world have you done to my dog?" This is what Mrs Shears screamed at Christopher. In this novel, the main character Christopher wanted to find out who killed Wellington, his neighbour Mrs Shear's dog. Mrs Shears thought that Christopher had killed it. Like many people with Aspergers Syndrome, Christopher is obsessed with details, loves puzzles and gets confused by too much information coming at him. All of these elements come together as his quest changes from finding the killer of the next door neighbor’s dog to a quest of a much more personal nature.

It's simply an expression to emphasis someone's surprise and shock at someone elses behavior. It's equivalent to "What are you doing?!" but the "F" word conveys a very strong anger.

hahahhaah it means "what are you doing" lol