Linked list sorting

Gll * fun_s(Gll* node,comp_fun comp )
{
    if(!node || !(node -> next) ){
        printf("less than two node in the list\n");
        return node;
    }
    //int ints[] = {12,2,3,4,5,6,1,8,9,10,11,7};
    //int ints[] = {1,12,2,3,5,8,4,9,6,10,11,7};
    while ( 1 ){

        Gll *prev,*curr,*nxt ;
        int swap = 0;
        prev = curr = node ;
        nxt = curr->next;
        while( nxt ) {
            if ( (*comp)(curr->data ,nxt->data) > 0) {
                curr -> next = nxt -> next;
                nxt -> next = curr;
                if(curr == node){
                    prev = node = nxt;
                }else{
                    prev -> next = nxt;
                    prev = nxt ;
                }
                swap = 1;
            }else {
                prev = curr;
            }
            curr = prev -> next ;
            nxt = curr -> next;

        }
        if(!swap)
            break;
    }
        return node;
}