FreeBSD/Linux Kernel Cross Reference
sys/kern/uipc_domain.c

     /*-
      * SPDX-License-Identifier: BSD-3-Clause
      *
      * 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.
     * 3. 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/epoch.h>
    #include <sys/mbuf.h>
    #include <sys/kernel.h>
    #include <sys/lock.h>
    #include <sys/mutex.h>
    #include <sys/rmlock.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 *);
    
    static struct rmlock pftimo_lock;
    RM_SYSINIT(pftimo_lock, &pftimo_lock, "pftimo");
    
    static LIST_HEAD(, protosw) pffast_list =
        LIST_HEAD_INITIALIZER(pffast_list);
    static LIST_HEAD(, protosw) pfslow_list =
        LIST_HEAD_INITIALIZER(pfslow_list);
    
    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);
   
                   /*
                    * Note that with VIMAGE enabled, domain_init() will be
                    * re-invoked for each new vnet that's created.  The below lists
                    * are intended to be system-wide, so avoid altering global
                    * state for non-default vnets.
                    */
                   if (IS_DEFAULT_VNET(curvnet)) {
                           rm_wlock(&pftimo_lock);
                           if (pr->pr_fasttimo != NULL)
                                   LIST_INSERT_HEAD(&pffast_list, pr,
                                       pr_fasttimos);
                           if (pr->pr_slowtimo != NULL)
                                   LIST_INSERT_HEAD(&pfslow_list, pr,
                                       pr_slowtimos);
                           rm_wunlock(&pftimo_lock);
                   }
           }
   
           /*
            * 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);
   }
   
   void
   domain_remove(void *data)
   {
           struct domain *dp = (struct domain *)data;
   
           if (dp->dom_family != PF_NETLINK)
                   return;
   
           mtx_lock(&dom_mtx);
           if (domains == dp) {
                   domains = dp->dom_next;
           } else {
                   struct domain *curr;
                   for (curr = domains; curr != NULL; curr = curr->dom_next) {
                           if (curr->dom_next == dp) {
                                   curr->dom_next = dp->dom_next;
                                   break;
                           }
                   }
           }
           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));
   
           rm_wlock(&pftimo_lock);
           if (fpr->pr_fasttimo != NULL)
                   LIST_INSERT_HEAD(&pffast_list, fpr, pr_fasttimos);
           if (fpr->pr_slowtimo != NULL)
                   LIST_INSERT_HEAD(&pfslow_list, fpr, pr_slowtimos);
           rm_wunlock(&pftimo_lock);
   
           /* 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);
           }
   
           rm_wlock(&pftimo_lock);
           if (dpr->pr_fasttimo != NULL)
                   LIST_REMOVE(dpr, pr_fasttimos);
           if (dpr->pr_slowtimo != NULL)
                   LIST_REMOVE(dpr, pr_slowtimos);
           rm_wunlock(&pftimo_lock);
   
           /* 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;
   
           NET_EPOCH_ASSERT();
   
           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);
   }
   
   static void
   pfslowtimo(void *arg)
   {
           struct rm_priotracker tracker;
           struct epoch_tracker et;
           struct protosw *pr;
   
           rm_rlock(&pftimo_lock, &tracker);
           NET_EPOCH_ENTER(et);
           LIST_FOREACH(pr, &pfslow_list, pr_slowtimos) {
                   (*pr->pr_slowtimo)();
           }
           NET_EPOCH_EXIT(et);
           rm_runlock(&pftimo_lock, &tracker);
           callout_reset(&pfslow_callout, hz / PR_SLOWHZ, pfslowtimo, NULL);
   }
   
   static void
   pffasttimo(void *arg)
   {
           struct rm_priotracker tracker;
           struct epoch_tracker et;
           struct protosw *pr;
   
           rm_rlock(&pftimo_lock, &tracker);
           NET_EPOCH_ENTER(et);
           LIST_FOREACH(pr, &pffast_list, pr_fasttimos) {
                   (*pr->pr_fasttimo)();
           }
           NET_EPOCH_EXIT(et);
           rm_runlock(&pftimo_lock, &tracker);
           callout_reset(&pffast_callout, hz / PR_FASTHZ, pffasttimo, NULL);
   }

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