/*	$NetBSD: natm.c,v 1.5 1996/11/09 03:26:26 chuck Exp $	*/
/*-
 *
 * Copyright (c) 1996 Charles D. Cranor and Washington University.
 * Copyright (c) 2005-2006 Robert N. M. Watson
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Charles D. Cranor and
 *      Washington University.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * natm.c: Native mode ATM access (both aal0 and aal5).
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/sys/netnatm/natm.c,v 1.47 2006/04/23 16:33:56 rwatson Exp $");

#include <sys/param.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sockio.h>
#include <sys/sx.h>
#include <sys/systm.h>
#include <sys/sysctl.h>

#include <net/if.h>
#include <net/if_atm.h>
#include <net/netisr.h>

#include <netinet/in.h>

#include <netnatm/natm.h>

static const u_long	natm5_sendspace = 16*1024;
static const u_long	natm5_recvspace = 16*1024;

static const u_long	natm0_sendspace = 16*1024;
static const u_long	natm0_recvspace = 16*1024;

/*
 * netnatm global subsystem lock, protects all global data structures in
 * netnatm.
 */
struct mtx	natm_mtx;

/*
 * User socket requests.
 */
static int	natm_usr_attach(struct socket *, int, d_thread_t *);
static void	natm_usr_detach(struct socket *);
static int	natm_usr_connect(struct socket *, struct sockaddr *,
		    d_thread_t *);
static int	natm_usr_disconnect(struct socket *);
static int	natm_usr_shutdown(struct socket *);
static int	natm_usr_send(struct socket *, int, struct mbuf *,
		    struct sockaddr *, struct mbuf *, d_thread_t *);
static int	natm_usr_peeraddr(struct socket *, struct sockaddr **);
static int	natm_usr_control(struct socket *, u_long, caddr_t,
		    struct ifnet *, d_thread_t *);
static void	natm_usr_abort(struct socket *);
static int	natm_usr_bind(struct socket *, struct sockaddr *,
		    d_thread_t *);
static int	natm_usr_sockaddr(struct socket *, struct sockaddr **);

static int
natm_usr_attach(struct socket *so, int proto, d_thread_t *p)
{
	struct natmpcb *npcb;
	int error = 0;

	npcb = (struct natmpcb *)so->so_pcb;
	KASSERT(npcb == NULL, ("natm_usr_attach: so_pcb != NULL"));

	if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
		if (proto == PROTO_NATMAAL5) 
			error = soreserve(so, natm5_sendspace,
			    natm5_recvspace);
		else
			error = soreserve(so, natm0_sendspace,
			    natm0_recvspace);
		if (error)
			return (error);
	}
	so->so_pcb = npcb = npcb_alloc(M_WAITOK);
	npcb->npcb_socket = so;
	return (error);
}

static void
natm_usr_detach(struct socket *so)
{
	struct natmpcb *npcb;

	npcb = (struct natmpcb *)so->so_pcb;
	KASSERT(npcb != NULL, ("natm_usr_detach: npcb == NULL"));

	NATM_LOCK();
	npcb_free(npcb, NPCB_DESTROY);	/* drain */
	so->so_pcb = NULL;
	NATM_UNLOCK();
}

static int
natm_usr_connect(struct socket *so, struct sockaddr *nam, d_thread_t *p)
{
	struct natmpcb *npcb;
	struct sockaddr_natm *snatm;
	struct atmio_openvcc op;
	struct ifnet *ifp;
	int error = 0;
	int proto = so->so_proto->pr_protocol;

	npcb = (struct natmpcb *)so->so_pcb;
	KASSERT(npcb != NULL, ("natm_usr_connect: npcb == NULL"));

	/*
	 * Validate nam and npcb.
	 */
	NATM_LOCK();
	snatm = (struct sockaddr_natm *)nam;
	if (snatm->snatm_len != sizeof(*snatm) ||
		(npcb->npcb_flags & NPCB_FREE) == 0) {
		NATM_UNLOCK();
		return (EINVAL);
	}
	if (snatm->snatm_family != AF_NATM) {
		NATM_UNLOCK();
		return (EAFNOSUPPORT);
	}

	snatm->snatm_if[IFNAMSIZ - 1] = '\0';	/* XXX ensure null termination
						   since ifunit() uses strcmp */

	/*
	 * Convert interface string to ifp, validate.
	 */
	ifp = ifunit(snatm->snatm_if);
	if (ifp == NULL || (ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
		NATM_UNLOCK();
		return (ENXIO);
	}
	if (ifp->if_output != atm_output) {
		NATM_UNLOCK();
		return (EAFNOSUPPORT);
	}

	/*
	 * Register us with the NATM PCB layer.
	 */
	if (npcb_add(npcb, ifp, snatm->snatm_vci, snatm->snatm_vpi) != npcb) {
		NATM_UNLOCK();
		return (EADDRINUSE);
	}

	/*
	 * Open the channel.
	 *
	 * XXXRW: Eventually desirable to hold mutex over ioctl?
	 */
	bzero(&op, sizeof(op));
	op.rxhand = npcb;
	op.param.flags = ATMIO_FLAG_PVC;
	op.param.vpi = npcb->npcb_vpi;
	op.param.vci = npcb->npcb_vci;
	op.param.rmtu = op.param.tmtu = ifp->if_mtu;
	op.param.aal = (proto == PROTO_NATMAAL5) ? ATMIO_AAL_5 : ATMIO_AAL_0;
	op.param.traffic = ATMIO_TRAFFIC_UBR;
	NATM_UNLOCK();

	IFF_LOCKGIANT(ifp);
	if (ifp->if_ioctl == NULL || 
	    ifp->if_ioctl(ifp, SIOCATMOPENVCC, (caddr_t)&op) != 0) {
		IFF_UNLOCKGIANT(ifp);
		return (EIO);
	}
	IFF_UNLOCKGIANT(ifp);
	soisconnected(so);
	return (error);
}

static int
natm_usr_disconnect(struct socket *so)
{
	struct natmpcb *npcb;
	struct atmio_closevcc cl;
	struct ifnet *ifp;
	int error = 0;

	npcb = (struct natmpcb *)so->so_pcb;
	KASSERT(npcb != NULL, ("natm_usr_disconnect: npcb == NULL"));

	NATM_LOCK();
	if ((npcb->npcb_flags & NPCB_CONNECTED) == 0) {
		NATM_UNLOCK();
		printf("natm: disconnected check\n");
		return (EIO);
	}
	ifp = npcb->npcb_ifp;

	/*
	 * Disable rx.
	 *
	 * XXXRW: Eventually desirable to hold mutex over ioctl?
	 */
	cl.vpi = npcb->npcb_vpi;
	cl.vci = npcb->npcb_vci;
	NATM_UNLOCK();
	if (ifp->if_ioctl != NULL) {
		IFF_LOCKGIANT(ifp);
		ifp->if_ioctl(ifp, SIOCATMCLOSEVCC, (caddr_t)&cl);
		IFF_UNLOCKGIANT(ifp);
	}
	soisdisconnected(so);
	return (error);
}

static int
natm_usr_shutdown(struct socket *so)
{

	socantsendmore(so);
	return (0);
}

static int
natm_usr_send(struct socket *so, int flags, struct mbuf *m, 
	struct sockaddr *nam, struct mbuf *control, d_thread_t *p)
{
	struct natmpcb *npcb;
	struct atm_pseudohdr *aph;
	int error = 0;
	int proto = so->so_proto->pr_protocol;

	npcb = (struct natmpcb *)so->so_pcb;
	KASSERT(npcb != NULL, ("natm_usr_send: npcb == NULL"));

	NATM_LOCK();
	if (control && control->m_len) {
		NATM_UNLOCK();
		m_freem(control);
		m_freem(m);
		return (EINVAL);
	}

	/*
	 * Send the data.  We must put an atm_pseudohdr on first.
	 */
	M_PREPEND(m, sizeof(*aph), M_DONTWAIT);
	if (m == NULL) {
		NATM_UNLOCK();
		m_freem(control);
		return (ENOBUFS);
	}
	aph = mtod(m, struct atm_pseudohdr *);
	ATM_PH_VPI(aph) = npcb->npcb_vpi;
	ATM_PH_SETVCI(aph, npcb->npcb_vci);
	ATM_PH_FLAGS(aph) = (proto == PROTO_NATMAAL5) ? ATM_PH_AAL5 : 0;
	error = atm_output(npcb->npcb_ifp, m, NULL, NULL);
	NATM_UNLOCK();
	return (error);
}

static int
natm_usr_peeraddr(struct socket *so, struct sockaddr **nam)
{
	struct natmpcb *npcb;
	struct sockaddr_natm *snatm, ssnatm;

	npcb = (struct natmpcb *)so->so_pcb;
	KASSERT(npcb != NULL, ("natm_usr_peeraddr: npcb == NULL"));

	NATM_LOCK();
	snatm = &ssnatm;
	bzero(snatm, sizeof(*snatm));
	snatm->snatm_len = sizeof(*snatm);
	snatm->snatm_family = AF_NATM;
	strlcpy(snatm->snatm_if, npcb->npcb_ifp->if_xname,
	    sizeof(snatm->snatm_if));
	snatm->snatm_vci = npcb->npcb_vci;
	snatm->snatm_vpi = npcb->npcb_vpi;
	NATM_UNLOCK();
	*nam = sodupsockaddr((struct sockaddr *)snatm, M_WAITOK);
	return (0);
}

static int
natm_usr_control(struct socket *so, u_long cmd, caddr_t arg,
	struct ifnet *ifp, d_thread_t *p)
{
	struct natmpcb *npcb;
	int error;

	npcb = (struct natmpcb *)so->so_pcb;
	KASSERT(npcb != NULL, ("natm_usr_control: npcb == NULL"));

	if (ifp == NULL || ifp->if_ioctl == NULL)
		return (EOPNOTSUPP);
	IFF_LOCKGIANT(ifp);
	error = ((*ifp->if_ioctl)(ifp, cmd, arg));
	IFF_UNLOCKGIANT(ifp);
	return (error);
}

static void
natm_usr_abort(struct socket *so)
{

	natm_usr_detach(so);
}

static int
natm_usr_bind(struct socket *so, struct sockaddr *nam, d_thread_t *p)
{

	return (EOPNOTSUPP);
}

static int
natm_usr_sockaddr(struct socket *so, struct sockaddr **nam)
{

	return (EOPNOTSUPP);
}

/* xxx - should be const */
struct pr_usrreqs natm_usrreqs = {
	.pru_abort =		natm_usr_abort,
	.pru_attach =		natm_usr_attach,
	.pru_bind =		natm_usr_bind,
	.pru_connect =		natm_usr_connect,
	.pru_control =		natm_usr_control,
	.pru_detach =		natm_usr_detach,
	.pru_disconnect =	natm_usr_disconnect,
	.pru_peeraddr =		natm_usr_peeraddr,
	.pru_send =		natm_usr_send,
	.pru_shutdown =		natm_usr_shutdown,
	.pru_sockaddr =		natm_usr_sockaddr,
};

/*
 * natmintr: interrupt
 *
 * Note: we expect a socket pointer in rcvif rather than an interface
 * pointer.  We can get the interface pointer from the so's PCB if we really
 * need it.
 */
void
natmintr(struct mbuf *m)
{
	struct socket *so;
	struct natmpcb *npcb;

#ifdef DIAGNOSTIC
	M_ASSERTPKTHDR(m);
#endif

	NATM_LOCK();
	npcb = (struct natmpcb *)m->m_pkthdr.rcvif;	/* XXX: overloaded */
	so = npcb->npcb_socket;

	npcb->npcb_inq--;

	if (npcb->npcb_flags & NPCB_DRAIN) {
		if (npcb->npcb_inq == 0)
			FREE(npcb, M_PCB);			/* done! */
		NATM_UNLOCK();
		m_freem(m);
		return;
	}

	if (npcb->npcb_flags & NPCB_FREE) {
		NATM_UNLOCK();
		m_freem(m);					/* drop */
		return;
	}

#ifdef NEED_TO_RESTORE_IFP
	m->m_pkthdr.rcvif = npcb->npcb_ifp;
#else
#ifdef DIAGNOSTIC
	m->m_pkthdr.rcvif = NULL;	/* null it out to be safe */
#endif
#endif

	if (sbspace(&so->so_rcv) > m->m_pkthdr.len) {
#ifdef NATM_STAT
		natm_sookcnt++;
		natm_sookbytes += m->m_pkthdr.len;
#endif
		sbappendrecord(&so->so_rcv, m);
		sorwakeup(so);
		NATM_UNLOCK();
	} else {
#ifdef NATM_STAT
		natm_sodropcnt++;
		natm_sodropbytes += m->m_pkthdr.len;
#endif
		NATM_UNLOCK();
		m_freem(m);
	}
}

/* 
 * natm0_sysctl: not used, but here in case we want to add something
 * later...
 */
int
natm0_sysctl(SYSCTL_HANDLER_ARGS)
{

	/* All sysctl names at this level are terminal. */
	return (ENOENT);
}

/* 
 * natm5_sysctl: not used, but here in case we want to add something
 * later...
 */
int
natm5_sysctl(SYSCTL_HANDLER_ARGS)
{

	/* All sysctl names at this level are terminal. */
	return (ENOENT);
}
