double linked list

#include<stdio.h>
struct linked_list
{
    int data;
    struct linked_list *next;
};
typedef struct linked_list *node;

node createnode()
{
    node temp;
    temp=(node)malloc(sizeof(node));
    temp->next=NULL;
    return temp;
}
node add_node(node head,int value)
{
    node temp=createnode(),p;
    temp->data=value;
    if(head==NULL)
        head=temp;
    else
    {
        p=head;
        while(p->next!=NULL)
            p=p->next;
        p->next=temp;
    }
    return head;
}
node add_node_front(node head,int value)
{
    node p=createnode();

    p->data=value;
    p->next=head;
    head=p;

    return head;
}
void print_node(node head)
{
    node a;
    if(head==NULL)
        printf("empty\n");
    else
    {
        a=head;
        while(a!=NULL)
        {
            printf("%d ",a->data);
            a=a->next;
        }
    }
    printf("\n");
}
node print_node_rev(node head)
{
    node prev,next,current;
    current=head;
    prev=NULL;
    while(current!=NULL)
    {
        next=current->next;
        current->next=prev;
        prev=current;
        current=next;
    }
    head=prev;
    return head;
}

int main()
{
    printf("enter 1 to add node at thge end\nenter 2 to add node at the front\nenter 3 to print\nenter 4 to print rev\n");
    int n;
    node head;
    head=NULL;
x:
    scanf("%d",&n);
    if(n==1)
    {
        int ndata;
        printf("new data\n");
        scanf("%d",&ndata);
        head=add_node(head,ndata);
        goto x;
    }
    else if(n==3)
    {
        print_node(head);
        goto x;
    }
    else if(n==2)
    {

        int mdata;
        printf("new data\n");
        scanf("%d",&mdata);
        head=add_node_front(head,mdata);
        goto x;
    }
    else if(n==4)
    {
        head=print_node_rev(head);
        print_node(head);
        goto x;
    }
    else if(n==0)
        return 0;
}