Function prison_remote_ip4

freebsd/netinet/in_jail.c:335–368

* Rewrite destination address in case we will connect to loopback address. * * Returns 0 on success, EAFNOSUPPORT if the jail doesn't allow IPv4. * Address passed in in NBO and returned in NBO. */

 * Address passed in in NBO and returned in NBO.
 */
int
prison_remote_ip4(struct ucred *cred, struct in_addr *ia)
{
	struct prison *pr;

	KASSERT(cred != NULL, ("%s: cred is NULL", __func__));
	KASSERT(ia != NULL, ("%s: ia is NULL", __func__));

	pr = cred->cr_prison;
	if (!(pr->pr_flags & PR_IP4))
		return (0);
	mtx_lock(&pr->pr_mtx);
	if (!(pr->pr_flags & PR_IP4)) {
		mtx_unlock(&pr->pr_mtx);
		return (0);
	}
	if (pr->pr_ip4 == NULL) {
		mtx_unlock(&pr->pr_mtx);
		return (EAFNOSUPPORT);
	}

	if (ntohl(ia->s_addr) == INADDR_LOOPBACK &&
	    prison_check_ip4_locked(pr, ia) == EADDRNOTAVAIL) {
		ia->s_addr = pr->pr_ip4[0].s_addr;
		mtx_unlock(&pr->pr_mtx);
		return (0);
	}

	/*
	 * Return success because nothing had to be changed.
	 */
	mtx_unlock(&pr->pr_mtx);
	return (0);
}

/*
 * Check if given address belongs to the jail referenced by cred/prison.