Localhost-only TCP connection checker

Challenge

Implement int check_local(const char *host, int port) that:

• Returns -2 if host is not exactly the string "127.0.0.1" (refuses non-localhost).
• Returns 1 if a TCP connection to 127.0.0.1:port succeeds.
• Returns 0 if the connection is refused or fails.

This is the canonical defensive shape of a local-only tool: the policy check is the first line of code.

Starter code

#include <sys/socket.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <string.h>

int check_local(const char *host, int port) {
    /* TODO */
    return -1;
}