Add a very simplistic PF_INET/SOCK_DGRAM domain/proto implementation,
which delegates the work to host kernel sockets.  This does not
run the entire kernel TCP/IP stack in userspace and therefore does
not require the ability to send or receive raw packets.  This
implies that root priviledges are not required.  As already said
above, only supports UDPv4 for now.  Extending should be easy.


(pooka)

#	$NetBSD: Makefile,v 1.1 2008/10/02 21:59:19 pooka Exp $
#

SUBDIR=	lib

.include <bsd.subdir.mk>

#	$NetBSD
#

RUMPNETLIST=	sockin

.for var in ${RUMPNETLIST}
RUMPNETLIBS+=lib${var}
RUMPNETLDADD+=-lrumpnet_${var}
.endfor

#	$NetBSD: Makefile,v 1.1 2008/10/02 21:59:19 pooka Exp $
#

.include "${.CURDIR}/../Makefile.rumpnet"

SUBDIR+=	${RUMPNETLIBS}

.include <bsd.subdir.mk>

#	$NetBSD: Makefile.inc,v 1.1 2008/10/02 21:59:19 pooka Exp $
#

RUMPTOP=	${.CURDIR}/../../..

.include "${RUMPTOP}/Makefile.rump"

#	$NetBSD: Makefile,v 1.1 2008/10/02 21:59:20 pooka Exp $
#

LIB=	rumpnet_sockin

SRCS=	sockin.c

.include <bsd.lib.mk>
.include <bsd.klinks.mk>

#	$NetBSD: shlib_version,v 1.1 2008/10/02 21:59:20 pooka Exp $
#
major=0
minor=0

/*	$NetBSD: sockin.c,v 1.1 2008/10/02 21:59:20 pooka Exp $	*/

/*
 * Copyright (c) 2008 Antti Kantee.  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.
 *
 * 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 OR CONTRIBUTORS 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.
 */

#include <sys/param.h>
#include <sys/condvar.h>
#include <sys/domain.h>
#include <sys/kmem.h>
#include <sys/kthread.h>
#include <sys/mbuf.h>
#include <sys/mutex.h>
#include <sys/poll.h>
#include <sys/protosw.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/time.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>

#include <rump/rumpuser.h>

/*
 * An inet communication domain which uses the socket interface.
 * Currently supports only IPv4 UDP, but could easily be extended to
 * support IPv6 and TCP by adding more stuff to the protosw.
 */

DOMAIN_DEFINE(sockindomain);

static void	sockin_init(void);
static int	sockin_usrreq(struct socket *, int, struct mbuf *,
			      struct mbuf *, struct mbuf *, struct lwp *);

const struct protosw sockinsw[] = {
{	.pr_type = SOCK_DGRAM,
	.pr_domain = &sockindomain,
	.pr_protocol = IPPROTO_UDP,
	.pr_flags = PR_ATOMIC|PR_ADDR,
	.pr_usrreq = sockin_usrreq,
	.pr_init = sockin_init,
}};

struct domain sockindomain = {
	.dom_family = PF_INET,
	.dom_name = "socket_inet",
	.dom_init = NULL,
	.dom_externalize = NULL,
	.dom_dispose = NULL,
	.dom_protosw = sockinsw,
	.dom_protoswNPROTOSW = &sockinsw[__arraycount(&sockinsw)], 
	.dom_rtattach = NULL,
	.dom_rtoffset = 0,
	.dom_maxrtkey = 0,
	.dom_ifattach = NULL,
	.dom_ifdetach = NULL,
	.dom_ifqueues = { NULL },
	.dom_link = { NULL },
	.dom_mowner = MOWNER_INIT("",""),
	.dom_rtcache = { NULL },
	.dom_sockaddr_cmp = NULL
};

/* only for testing */
#if 0
#define SOCKIN_NOTHREAD
#endif

#define SO2S(so) ((int)(so->so_internal))

static void
sockin_process(struct socket *so)
{
	struct sockaddr_in from;
	struct iovec io;
	struct msghdr rmsg;
	struct mbuf *m;
	ssize_t n;
	size_t plen;
	int error;

	plen = IP_MAXPACKET;
	m = m_gethdr(M_WAIT, MT_DATA);
	MEXTMALLOC(m, plen, M_WAIT);

	memset(&rmsg, 0, sizeof(rmsg));
	io.iov_base = mtod(m, void *);
	io.iov_len = plen;
	rmsg.msg_iov = &io;
	rmsg.msg_iovlen = 1;
	rmsg.msg_name = (struct sockaddr *)&from;
	rmsg.msg_namelen = sizeof(from);

	n = rumpuser_net_recvmsg(SO2S(so), &rmsg, 0, &error);
	if (n <= 0) {
		m_freem(m);
		return;
	}
	m->m_len = m->m_pkthdr.len = n;

	if (!sbappendaddr(&so->so_rcv, rmsg.msg_name, m, NULL)) {
		m_freem(m);
	}
	sorwakeup(so);
}

struct sockin_unit {
	struct socket *su_so;

	LIST_ENTRY(sockin_unit) su_entries;
};
static LIST_HEAD(, sockin_unit) su_ent = LIST_HEAD_INITIALIZER(su_ent);
static kmutex_t su_mtx;
static bool rebuild;
static int nsock;

#ifndef SOCKIN_NOTHREAD
#define POLLTIMEOUT 100	/* check for new entries every 100ms */

/* XXX: doesn't handle socket (kernel) locking properly? */
static void
sockinworker(void *arg)
{
	struct pollfd *pfds = NULL, *npfds;
	struct sockin_unit *su_iter;
	int cursock = 0, i, rv, error;

	/*
	 * Loop reading requests.  Check for new sockets periodically
	 * (could be smarter, but I'm lazy).
	 */
	for (;;) {
		if (rebuild) {
			npfds = NULL;
			mutex_enter(&su_mtx);
			if (nsock)
				npfds = kmem_alloc(nsock * sizeof(*npfds),
				    KM_NOSLEEP);
			if (npfds || nsock == 0) {
				if (pfds)
					kmem_free(pfds, cursock*sizeof(*pfds));
				pfds = npfds;
				cursock = nsock;
				rebuild = false;

				i = 0;
				LIST_FOREACH(su_iter, &su_ent, su_entries) {
					pfds[i].fd = SO2S(su_iter->su_so);
					pfds[i].events = POLLIN;
					pfds[i].revents = 0;
					i++;
				}
				KASSERT(i == nsock);
			}
			mutex_exit(&su_mtx);
		}

		/* find affected sockets & process */
		rv = rumpuser_poll(pfds, cursock, POLLTIMEOUT, &error);
		for (i = 0; i < cursock && rv > 0; i++) {
			if (pfds[i].revents & POLLIN) {
				mutex_enter(&su_mtx);
				LIST_FOREACH(su_iter, &su_ent, su_entries) {
					if (SO2S(su_iter->su_so)==pfds[i].fd) {
						mutex_enter(softnet_lock);
						sockin_process(su_iter->su_so);
						mutex_exit(softnet_lock);
						break;
					}
				}
				/* if we can't find it, just wing it */
				KASSERT(rebuild || su_iter);
				mutex_exit(&su_mtx);
				pfds[i].revents = 0;
				rv--;
				i = -1;
				continue;
			}

			/* something else?  ignore */
			if (pfds[i].revents) {
				pfds[i].revents = 0;
				rv--;
			}
		}
		KASSERT(rv <= 0);
	}
	
}
#endif /* SOCKIN_NOTHREAD */

static void
sockin_init()
{
#ifndef SOCKIN_NOTHREAD
	int rv;

	if ((rv = kthread_create(PRI_NONE, 0, NULL, sockinworker,
	    NULL, NULL, "sockwork")) != 0)
		panic("sockin_init: could not create worker thread\n");
#endif
	mutex_init(&su_mtx, MUTEX_DEFAULT, IPL_NONE);
}

static int
sockin_usrreq(struct socket *so, int req, struct mbuf *m, struct mbuf *nam,
	struct mbuf *control, struct lwp *l)
{
	int error = 0;

	switch (req) {
	case PRU_ATTACH:
	{
		struct sockin_unit *su;
		int news;

		sosetlock(so);

		su = kmem_alloc(sizeof(*su), KM_NOSLEEP);
		if (!su) {
			error = ENOMEM;
			break;
		}

		news = rumpuser_net_socket(PF_INET, SOCK_DGRAM, 0, &error);
		if (news == -1) {
			kmem_free(su, sizeof(*su));
			break;
		}
		so->so_internal = (void *)news;
		su->su_so = so;

		mutex_enter(&su_mtx);
		LIST_INSERT_HEAD(&su_ent, su, su_entries);
		nsock++;
		rebuild = true;
		mutex_exit(&su_mtx);
		break;
	}

	case PRU_CONNECT:
		/* sorry dear, not today */
		break;

	case PRU_SEND:
	{
		struct sockaddr *saddr;
		struct msghdr mhdr;
		struct iovec iov[16];
		struct mbuf *m2;
		size_t tot;
		int i, s;

		memset(&mhdr, 0, sizeof(mhdr));

		tot = 0;
		for (i = 0, m2 = m; m2; m2 = m2->m_next, i++) {
			if (i > 16)
				panic("lazy bum");
			iov[i].iov_base = m2->m_data;
			iov[i].iov_len = m2->m_len;
			tot += m2->m_len;

		}
		saddr = mtod(nam, struct sockaddr *);
		mhdr.msg_name = saddr;
		mhdr.msg_namelen = saddr->sa_len;
		mhdr.msg_iov = iov;
		mhdr.msg_iovlen = i;

		s = (int)so->so_internal;
		rumpuser_net_sendmsg(s, &mhdr, 0, &error);
		m_freem(m);
		m_freem(control);
#ifdef SOCKIN_NOTHREAD
		/* this assumes too many things to list.. buthey, testing */
		sockin_process(so);
#endif
	}
		break;

	case PRU_SHUTDOWN:
	{
		struct sockin_unit *su_iter;

		mutex_enter(&su_mtx);
		LIST_FOREACH(su_iter, &su_ent, su_entries) {
			if (su_iter->su_so == so)
				break;
		}
		if (!su_iter)
			panic("no such socket");

		LIST_REMOVE(su_iter, su_entries);
		nsock--;
		rebuild = true;
		mutex_exit(&su_mtx);

		rumpuser_close(SO2S(su_iter->su_so), &error);
		kmem_free(su_iter, sizeof(*su_iter));
	}
		break;

	default:
		panic("sockin_usrreq: IMPLEMENT ME, req %d not supported", req);
	}

	return error;
}