rusted cast iron

Hi:
Due to my return to university, my time and money have gone towards study. I haven't gone camping this year and it doesn't look likely that I will be able to go next year. I left my trailer packed in case I actually had time and money to go somewhere, but it never happened.
Anyhow, this weekend, I was cleaning up the camper and preparing it for winter and when I pulled out the cast iron frying pan, most of the sides on the inside and some of the surface where the cooking is done is all rusty. It's just surface rust; only iron, something our bodies need anyhow but it is disconcerting.
I would assume that some of the seasoning has dissolved or was never done correctly in the first place. Is this pan a write-off. Are there ways of bringing it back.
Anyhow, thanks for your help.
Due to my return to university, my time and money have gone towards study. I haven't gone camping this year and it doesn't look likely that I will be able to go next year. I left my trailer packed in case I actually had time and money to go somewhere, but it never happened.
Anyhow, this weekend, I was cleaning up the camper and preparing it for winter and when I pulled out the cast iron frying pan, most of the sides on the inside and some of the surface where the cooking is done is all rusty. It's just surface rust; only iron, something our bodies need anyhow but it is disconcerting.
I would assume that some of the seasoning has dissolved or was never done correctly in the first place. Is this pan a write-off. Are there ways of bringing it back.
Anyhow, thanks for your help.