text: /*-
   * Copyright (c) 1982, 1986, 1993
   *	The Regents of the University of California.  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.
   * 4. Neither the name of the University nor the names of its contributors
   *    may be used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS 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.
   *
   *	@(#)uipc_domain.c	8.2 (Berkeley) 10/18/93
   */
  
  #include <sys/cdefs.h>
  __FBSDID("$FreeBSD$");
  
  #include <sys/param.h>
  #include <sys/socket.h>
  #include <sys/protosw.h>
  #include <sys/domain.h>
  #include <sys/eventhandler.h>
  #include <sys/mbuf.h>
  #include <sys/kernel.h>
  #include <sys/lock.h>
  #include <sys/mutex.h>
  #include <sys/socketvar.h>
  #include <sys/systm.h>
  
  #include <net/vnet.h>
  
  /*
   * System initialization
   *
   * Note: domain initialization takes place on a per domain basis
   * as a result of traversing a SYSINIT linker set.  Most likely,
   * each domain would want to call DOMAIN_SET(9) itself, which
   * would cause the domain to be added just after domaininit()
   * is called during startup.
   *
   * See DOMAIN_SET(9) for details on its use.
   */
  
  static void domaininit(void *);
  SYSINIT(domain, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY, domaininit, NULL);
  
  static void domainfinalize(void *);
  SYSINIT(domainfin, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_FIRST, domainfinalize,
      NULL);
  
  static struct callout pffast_callout;
  static struct callout pfslow_callout;
  
  static void	pffasttimo(void *);
  static void	pfslowtimo(void *);
  
  struct domain *domains;		/* registered protocol domains */
  int domain_init_status = 0;
  static struct mtx dom_mtx;		/* domain list lock */
  MTX_SYSINIT(domain, &dom_mtx, "domain list", MTX_DEF);
  
  /*
   * Dummy protocol specific user requests function pointer array.
   * All functions return EOPNOTSUPP.
   */
  struct pr_usrreqs nousrreqs = {
  	.pru_accept =		pru_accept_notsupp,
  	.pru_attach =		pru_attach_notsupp,
  	.pru_bind =		pru_bind_notsupp,
  	.pru_connect =		pru_connect_notsupp,
  	.pru_connect2 =		pru_connect2_notsupp,
  	.pru_control =		pru_control_notsupp,
  	.pru_disconnect	=	pru_disconnect_notsupp,
  	.pru_listen =		pru_listen_notsupp,
  	.pru_peeraddr =		pru_peeraddr_notsupp,
  	.pru_rcvd =		pru_rcvd_notsupp,
  	.pru_rcvoob =		pru_rcvoob_notsupp,
  	.pru_send =		pru_send_notsupp,
  	.pru_sense =		pru_sense_null,
  	.pru_shutdown =		pru_shutdown_notsupp,
  	.pru_sockaddr =		pru_sockaddr_notsupp,
  	.pru_sosend =		pru_sosend_notsupp,
  	.pru_soreceive =	pru_soreceive_notsupp,
  	.pru_sopoll =		pru_sopoll_notsupp,
  };
  
  static void
  protosw_init(struct protosw *pr)
  {
  	struct pr_usrreqs *pu;
  
  	pu = pr->pr_usrreqs;
  	KASSERT(pu != NULL, ("protosw_init: %ssw[%d] has no usrreqs!",
  	    pr->pr_domain->dom_name,
  	    (int)(pr - pr->pr_domain->dom_protosw)));
  
  	/*
  	 * Protocol switch methods fall into three categories: mandatory,
  	 * mandatory but protosw_init() provides a default, and optional.
  	 *
  	 * For true protocols (i.e., pru_attach != NULL), KASSERT truly
  	 * mandatory methods with no defaults, and initialize defaults for
  	 * other mandatory methods if the protocol hasn't defined an
  	 * implementation (NULL function pointer).
  	 */
  #if 0
  	if (pu->pru_attach != NULL) {
  		KASSERT(pu->pru_abort != NULL,
  		    ("protosw_init: %ssw[%d] pru_abort NULL",
  		    pr->pr_domain->dom_name,
  		    (int)(pr - pr->pr_domain->dom_protosw)));
  		KASSERT(pu->pru_send != NULL,
  		    ("protosw_init: %ssw[%d] pru_send NULL",
  		    pr->pr_domain->dom_name,
  		    (int)(pr - pr->pr_domain->dom_protosw)));
  	}
  #endif
  
  #define DEFAULT(foo, bar)	if ((foo) == NULL)  (foo) = (bar)
  	DEFAULT(pu->pru_accept, pru_accept_notsupp);
  	DEFAULT(pu->pru_aio_queue, pru_aio_queue_notsupp);
  	DEFAULT(pu->pru_bind, pru_bind_notsupp);
  	DEFAULT(pu->pru_bindat, pru_bindat_notsupp);
  	DEFAULT(pu->pru_connect, pru_connect_notsupp);
  	DEFAULT(pu->pru_connect2, pru_connect2_notsupp);
  	DEFAULT(pu->pru_connectat, pru_connectat_notsupp);
  	DEFAULT(pu->pru_control, pru_control_notsupp);
  	DEFAULT(pu->pru_disconnect, pru_disconnect_notsupp);
  	DEFAULT(pu->pru_listen, pru_listen_notsupp);
  	DEFAULT(pu->pru_peeraddr, pru_peeraddr_notsupp);
  	DEFAULT(pu->pru_rcvd, pru_rcvd_notsupp);
  	DEFAULT(pu->pru_rcvoob, pru_rcvoob_notsupp);
  	DEFAULT(pu->pru_sense, pru_sense_null);
  	DEFAULT(pu->pru_shutdown, pru_shutdown_notsupp);
  	DEFAULT(pu->pru_sockaddr, pru_sockaddr_notsupp);
  	DEFAULT(pu->pru_sosend, sosend_generic);
  	DEFAULT(pu->pru_soreceive, soreceive_generic);
  	DEFAULT(pu->pru_sopoll, sopoll_generic);
  	DEFAULT(pu->pru_ready, pru_ready_notsupp);
  #undef DEFAULT
  	if (pr->pr_init)
  		(*pr->pr_init)();
  }
  
  /*
   * Add a new protocol domain to the list of supported domains
   * Note: you cant unload it again because a socket may be using it.
   * XXX can't fail at this time.
   */
  void
  domain_init(void *arg)
  {
  	struct domain *dp = arg;
  	struct protosw *pr;
  
  	if (dp->dom_init)
  		(*dp->dom_init)();
  	for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
  		protosw_init(pr);
  	/*
  	 * update global information about maximums
  	 */
  	max_hdr = max_linkhdr + max_protohdr;
  	max_datalen = MHLEN - max_hdr;
  	if (max_datalen < 1)
  		panic("%s: max_datalen < 1", __func__);
  }
  
  #ifdef VIMAGE
  void
  vnet_domain_init(void *arg)
  {
  
  	/* Virtualized case is no different -- call init functions. */
  	domain_init(arg);
  }
  
  void
  vnet_domain_uninit(void *arg)
  {
  	struct domain *dp = arg;
  
  	if (dp->dom_destroy)
  		(*dp->dom_destroy)();
  }
  #endif
  
  /*
   * Add a new protocol domain to the list of supported domains
   * Note: you cant unload it again because a socket may be using it.
   * XXX can't fail at this time.
   */
  void
  domain_add(void *data)
  {
  	struct domain *dp;
  
  	dp = (struct domain *)data;
  	mtx_lock(&dom_mtx);
  	dp->dom_next = domains;
  	domains = dp;
  
  	KASSERT(domain_init_status >= 1,
  	    ("attempt to domain_add(%s) before domaininit()",
  	    dp->dom_name));
  #ifndef INVARIANTS
  	if (domain_init_status < 1)
  		printf("WARNING: attempt to domain_add(%s) before "
  		    "domaininit()\n", dp->dom_name);
  #endif
  #ifdef notyet
  	KASSERT(domain_init_status < 2,
  	    ("attempt to domain_add(%s) after domainfinalize()",
  	    dp->dom_name));
  #else
  	if (domain_init_status >= 2)
  		printf("WARNING: attempt to domain_add(%s) after "
  		    "domainfinalize()\n", dp->dom_name);
  #endif
  	mtx_unlock(&dom_mtx);
  }
  
  /* ARGSUSED*/
  static void
  domaininit(void *dummy)
  {
  
  	if (max_linkhdr < 16)		/* XXX */
  		max_linkhdr = 16;
  
  	callout_init(&pffast_callout, 1);
  	callout_init(&pfslow_callout, 1);
  
  	mtx_lock(&dom_mtx);
  	KASSERT(domain_init_status == 0, ("domaininit called too late!"));
  	domain_init_status = 1;
  	mtx_unlock(&dom_mtx);
  }
  
  /* ARGSUSED*/
  static void
  domainfinalize(void *dummy)
  {
  
  	mtx_lock(&dom_mtx);
  	KASSERT(domain_init_status == 1, ("domainfinalize called too late!"));
  	domain_init_status = 2;
  	mtx_unlock(&dom_mtx);	
  
  	callout_reset(&pffast_callout, 1, pffasttimo, NULL);
  	callout_reset(&pfslow_callout, 1, pfslowtimo, NULL);
  }
  
  struct domain *
  pffinddomain(int family)
  {
  	struct domain *dp;
  
  	for (dp = domains; dp != NULL; dp = dp->dom_next)
  		if (dp->dom_family == family)
  			return (dp);
  	return (NULL);
  }
  
  struct protosw *
  pffindtype(int family, int type)
  {
  	struct domain *dp;
  	struct protosw *pr;
  
  	dp = pffinddomain(family);
  	if (dp == NULL)
  		return (NULL);
  
  	for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
  		if (pr->pr_type && pr->pr_type == type)
  			return (pr);
  	return (NULL);
  }
  
  struct protosw *
  pffindproto(int family, int protocol, int type)
  {
  	struct domain *dp;
  	struct protosw *pr;
  	struct protosw *maybe;
  
  	maybe = NULL;
  	if (family == 0)
  		return (NULL);
  
  	dp = pffinddomain(family);
  	if (dp == NULL)
  		return (NULL);
  
  	for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) {
  		if ((pr->pr_protocol == protocol) && (pr->pr_type == type))
  			return (pr);
  
  		if (type == SOCK_RAW && pr->pr_type == SOCK_RAW &&
  		    pr->pr_protocol == 0 && maybe == NULL)
  			maybe = pr;
  	}
  	return (maybe);
  }
  
  /*
   * The caller must make sure that the new protocol is fully set up and ready to
   * accept requests before it is registered.
   */
  int
  pf_proto_register(int family, struct protosw *npr)
  {
  	VNET_ITERATOR_DECL(vnet_iter);
  	struct domain *dp;
  	struct protosw *pr, *fpr;
  
  	/* Sanity checks. */
  	if (family == 0)
  		return (EPFNOSUPPORT);
  	if (npr->pr_type == 0)
  		return (EPROTOTYPE);
  	if (npr->pr_protocol == 0)
  		return (EPROTONOSUPPORT);
  	if (npr->pr_usrreqs == NULL)
  		return (ENXIO);
  
  	/* Try to find the specified domain based on the family. */
  	dp = pffinddomain(family);
  	if (dp == NULL)
  		return (EPFNOSUPPORT);
  
  	/* Initialize backpointer to struct domain. */
  	npr->pr_domain = dp;
  	fpr = NULL;
  
  	/*
  	 * Protect us against races when two protocol registrations for
  	 * the same protocol happen at the same time.
  	 */
  	mtx_lock(&dom_mtx);
  
  	/* The new protocol must not yet exist. */
  	for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) {
  		if ((pr->pr_type == npr->pr_type) &&
  		    (pr->pr_protocol == npr->pr_protocol)) {
  			mtx_unlock(&dom_mtx);
  			return (EEXIST);	/* XXX: Check only protocol? */
  		}
  		/* While here, remember the first free spacer. */
  		if ((fpr == NULL) && (pr->pr_protocol == PROTO_SPACER))
  			fpr = pr;
  	}
  
  	/* If no free spacer is found we can't add the new protocol. */
  	if (fpr == NULL) {
  		mtx_unlock(&dom_mtx);
  		return (ENOMEM);
  	}
  
  	/* Copy the new struct protosw over the spacer. */
  	bcopy(npr, fpr, sizeof(*fpr));
  
  	/* Job is done, no more protection required. */
  	mtx_unlock(&dom_mtx);
  
  	/* Initialize and activate the protocol. */
  	VNET_LIST_RLOCK();
  	VNET_FOREACH(vnet_iter) {
  		CURVNET_SET_QUIET(vnet_iter);
  		protosw_init(fpr);
  		CURVNET_RESTORE();
  	}
  	VNET_LIST_RUNLOCK();
  
  	return (0);
  }
  
  /*
   * The caller must make sure the protocol and its functions correctly shut down
   * all sockets and release all locks and memory references.
   */
  int
  pf_proto_unregister(int family, int protocol, int type)
  {
  	struct domain *dp;
  	struct protosw *pr, *dpr;
  
  	/* Sanity checks. */
  	if (family == 0)
  		return (EPFNOSUPPORT);
  	if (protocol == 0)
  		return (EPROTONOSUPPORT);
  	if (type == 0)
  		return (EPROTOTYPE);
  
  	/* Try to find the specified domain based on the family type. */
  	dp = pffinddomain(family);
  	if (dp == NULL)
  		return (EPFNOSUPPORT);
  
  	dpr = NULL;
  
  	/* Lock out everyone else while we are manipulating the protosw. */
  	mtx_lock(&dom_mtx);
  
  	/* The protocol must exist and only once. */
  	for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++) {
  		if ((pr->pr_type == type) && (pr->pr_protocol == protocol)) {
  			if (dpr != NULL) {
  				mtx_unlock(&dom_mtx);
  				return (EMLINK);   /* Should not happen! */
  			} else
  				dpr = pr;
  		}
  	}
  
  	/* Protocol does not exist. */
  	if (dpr == NULL) {
  		mtx_unlock(&dom_mtx);
  		return (EPROTONOSUPPORT);
  	}
  
  	/* De-orbit the protocol and make the slot available again. */
  	dpr->pr_type = 0;
  	dpr->pr_domain = dp;
  	dpr->pr_protocol = PROTO_SPACER;
  	dpr->pr_flags = 0;
  	dpr->pr_input = NULL;
  	dpr->pr_output = NULL;
  	dpr->pr_ctlinput = NULL;
  	dpr->pr_ctloutput = NULL;
  	dpr->pr_init = NULL;
  	dpr->pr_fasttimo = NULL;
  	dpr->pr_slowtimo = NULL;
  	dpr->pr_drain = NULL;
  	dpr->pr_usrreqs = &nousrreqs;
  
  	/* Job is done, not more protection required. */
  	mtx_unlock(&dom_mtx);
  
  	return (0);
  }
  
  void
  pfctlinput(int cmd, struct sockaddr *sa)
  {
  	struct domain *dp;
  	struct protosw *pr;
  
  	for (dp = domains; dp; dp = dp->dom_next)
  		for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
  			if (pr->pr_ctlinput)
  				(*pr->pr_ctlinput)(cmd, sa, (void *)0);
  }
  
  void
  pfctlinput2(int cmd, struct sockaddr *sa, void *ctlparam)
  {
  	struct domain *dp;
  	struct protosw *pr;
  
  	if (!sa)
  		return;
  	for (dp = domains; dp; dp = dp->dom_next) {
  		/*
  		 * the check must be made by xx_ctlinput() anyways, to
  		 * make sure we use data item pointed to by ctlparam in
  		 * correct way.  the following check is made just for safety.
  		 */
  		if (dp->dom_family != sa->sa_family)
  			continue;
  
  		for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
  			if (pr->pr_ctlinput)
  				(*pr->pr_ctlinput)(cmd, sa, ctlparam);
  	}
  }
  
  static void
  pfslowtimo(void *arg)
  {
  	struct domain *dp;
  	struct protosw *pr;
  
  	for (dp = domains; dp; dp = dp->dom_next)
  		for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
  			if (pr->pr_slowtimo)
  				(*pr->pr_slowtimo)();
  	callout_reset(&pfslow_callout, hz/2, pfslowtimo, NULL);
  }
  
  static void
  pffasttimo(void *arg)
  {
  	struct domain *dp;
  	struct protosw *pr;
  
  	for (dp = domains; dp; dp = dp->dom_next)
  		for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
  			if (pr->pr_fasttimo)
  				(*pr->pr_fasttimo)();
  	callout_reset(&pffast_callout, hz/5, pffasttimo, NULL);
  }
  