FreeBSD/Linux Kernel Cross Reference
sys/netgraph/ng_gif.c

     /*
      * ng_gif.c
      *
      * Copyright 2001 The Aerospace Corporation.  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. The name of The Aerospace Corporation may not be used to endorse or
     *    promote products derived from this software.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AEROSPACE CORPORATION ``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 AEROSPACE CORPORATION 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.
     *
     *
     * Copyright (c) 1996-2000 Whistle Communications, Inc.
     * All rights reserved.
     * 
     * Subject to the following obligations and disclaimer of warranty, use and
     * redistribution of this software, in source or object code forms, with or
     * without modifications are expressly permitted by Whistle Communications;
     * provided, however, that:
     * 1. Any and all reproductions of the source or object code must include the
     *    copyright notice above and the following disclaimer of warranties; and
     * 2. No rights are granted, in any manner or form, to use Whistle
     *    Communications, Inc. trademarks, including the mark "WHISTLE
     *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
     *    such appears in the above copyright notice or in the software.
     * 
     * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
     * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
     * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
     * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
     * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
     * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
     * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
     * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
     * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
     * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
     * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
     * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
     * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER 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 WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
     * OF SUCH DAMAGE.
     *
     * $FreeBSD: releng/5.3/sys/netgraph/ng_gif.c 136588 2004-10-16 08:43:07Z cvs2svn $
     */
    
    /*
     * ng_gif(4) netgraph node type
     */
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/kernel.h>
    #include <sys/malloc.h>
    #include <sys/mbuf.h>
    #include <sys/errno.h>
    #include <sys/syslog.h>
    #include <sys/socket.h>
    
    #include <net/if.h>
    #include <net/route.h>
    #include <net/if_types.h>
    #include <net/if_var.h>
    #include <net/if_gif.h>
    
    #include <netgraph/ng_message.h>
    #include <netgraph/netgraph.h>
    #include <netgraph/ng_parse.h>
    #include <netgraph/ng_gif.h>
    
    #define IFP2NG(ifp)  ((struct ng_node *)((struct gif_softc *)(ifp))->gif_netgraph)
    #define IFP2NG_SET(ifp, val)  (((struct gif_softc *)(ifp))->gif_netgraph = (val))
    
    /* Per-node private data */
    struct private {
            struct ifnet    *ifp;           /* associated interface */
            hook_p          lower;          /* lower OR orphan hook connection */
            u_char          lowerOrphan;    /* whether lower is lower or orphan */
    };
    typedef struct private *priv_p;
   
   /* Functional hooks called from if_gif.c */
   static void     ng_gif_input(struct ifnet *ifp, struct mbuf **mp, int af);
   static void     ng_gif_input_orphan(struct ifnet *ifp, struct mbuf *m, int af);
   static void     ng_gif_attach(struct ifnet *ifp);
   static void     ng_gif_detach(struct ifnet *ifp); 
   
   /* Other functions */
   static void     ng_gif_input2(node_p node, struct mbuf **mp, int af);
   static int      ng_gif_glue_af(struct mbuf **mp, int af);
   static int      ng_gif_rcv_lower(node_p node, struct mbuf *m);
   
   /* Netgraph node methods */
   static ng_constructor_t ng_gif_constructor;
   static ng_rcvmsg_t      ng_gif_rcvmsg;
   static ng_shutdown_t    ng_gif_shutdown;
   static ng_newhook_t     ng_gif_newhook;
   static ng_connect_t     ng_gif_connect;
   static ng_rcvdata_t     ng_gif_rcvdata;
   static ng_disconnect_t  ng_gif_disconnect;
   static int              ng_gif_mod_event(module_t mod, int event, void *data);
   
   /* List of commands and how to convert arguments to/from ASCII */
   static const struct ng_cmdlist ng_gif_cmdlist[] = {
           {
             NGM_GIF_COOKIE,
             NGM_GIF_GET_IFNAME,
             "getifname",
             NULL,
             &ng_parse_string_type
           },
           {
             NGM_GIF_COOKIE,
             NGM_GIF_GET_IFINDEX,
             "getifindex",
             NULL,
             &ng_parse_int32_type
           },
           { 0 }
   };
   
   static struct ng_type ng_gif_typestruct = {
           .version =      NG_ABI_VERSION,
           .name =         NG_GIF_NODE_TYPE,
           .mod_event =    ng_gif_mod_event,
           .constructor =  ng_gif_constructor,
           .rcvmsg =       ng_gif_rcvmsg,
           .shutdown =     ng_gif_shutdown,
           .newhook =      ng_gif_newhook,
           .connect =      ng_gif_connect,
           .rcvdata =      ng_gif_rcvdata,
           .disconnect =   ng_gif_disconnect,
           .cmdlist =      ng_gif_cmdlist,
   };
   MODULE_VERSION(ng_gif, 1);
   MODULE_DEPEND(ng_gif, if_gif, 1,1,1);
   NETGRAPH_INIT(gif, &ng_gif_typestruct);
   
   /******************************************************************
                          GIF FUNCTION HOOKS
   ******************************************************************/
   
   /*
    * Handle a packet that has come in on an interface. We get to
    * look at it here before any upper layer protocols do.
    *
    * NOTE: this function will get called at splimp()
    */
   static void
   ng_gif_input(struct ifnet *ifp, struct mbuf **mp, int af)
   {
           const node_p node = IFP2NG(ifp);
           const priv_p priv = NG_NODE_PRIVATE(node);
   
           /* If "lower" hook not connected, let packet continue */
           if (priv->lower == NULL || priv->lowerOrphan)
                   return;
           ng_gif_input2(node, mp, af);
   }
   
   /*
    * Handle a packet that has come in on an interface, and which
    * does not match any of our known protocols (an ``orphan'').
    *
    * NOTE: this function will get called at splimp()
    */
   static void
   ng_gif_input_orphan(struct ifnet *ifp, struct mbuf *m, int af)
   {
           const node_p node = IFP2NG(ifp);
           const priv_p priv = NG_NODE_PRIVATE(node);
   
           /* If "orphan" hook not connected, let packet continue */
           if (priv->lower == NULL || !priv->lowerOrphan) {
                   m_freem(m);
                   return;
           }
           ng_gif_input2(node, &m, af);
           if (m != NULL)
                   m_freem(m);
   }
   
   /*
    * Handle a packet that has come in on a gif interface.
    * Attach the address family to the mbuf for later use.
    *
    * NOTE: this function will get called at splimp()
    */
   static void
   ng_gif_input2(node_p node, struct mbuf **mp, int af)
   {
           const priv_p priv = NG_NODE_PRIVATE(node);
           int error;
   
           /* Glue address family on */
           if ((error = ng_gif_glue_af(mp, af)) != 0)
                   return;
   
           /* Send out lower/orphan hook */
           NG_SEND_DATA_ONLY(error, priv->lower, *mp);
           *mp = NULL;
   }
   
   /*
    * A new gif interface has been attached.
    * Create a new node for it, etc.
    */
   static void
   ng_gif_attach(struct ifnet *ifp)
   {
           priv_p priv;
           node_p node;
   
           /* Create node */
           KASSERT(!IFP2NG(ifp), ("%s: node already exists?", __func__));
           if (ng_make_node_common(&ng_gif_typestruct, &node) != 0) {
                   log(LOG_ERR, "%s: can't %s for %s\n",
                       __func__, "create node", ifp->if_xname);
                   return;
           }
   
           /* Allocate private data */
           MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
           if (priv == NULL) {
                   log(LOG_ERR, "%s: can't %s for %s\n",
                       __func__, "allocate memory", ifp->if_xname);
                   NG_NODE_UNREF(node);
                   return;
           }
           NG_NODE_SET_PRIVATE(node, priv);
           priv->ifp = ifp;
           IFP2NG_SET(ifp, node);
   
           /* Try to give the node the same name as the interface */
           if (ng_name_node(node, ifp->if_xname) != 0) {
                   log(LOG_WARNING, "%s: can't name node %s\n",
                       __func__, ifp->if_xname);
           }
   }
   
   /*
    * An interface is being detached.
    * REALLY Destroy its node.
    */
   static void
   ng_gif_detach(struct ifnet *ifp)
   {
           const node_p node = IFP2NG(ifp);
           priv_p priv;
   
           if (node == NULL)               /* no node (why not?), ignore */
                   return;
           priv = NG_NODE_PRIVATE(node);
           NG_NODE_REALLY_DIE(node);       /* Force real removal of node */
           /*
            * We can't assume the ifnet is still around when we run shutdown
            * So zap it now. XXX We HOPE that anything running at this time
            * handles it (as it should in the non netgraph case).
            */
           IFP2NG_SET(ifp, NULL);
           priv->ifp = NULL;       /* XXX race if interrupted an output packet */
           ng_rmnode_self(node);           /* remove all netgraph parts */
   }
   
   /*
    * Optimization for gluing the address family onto
    * the front of an incoming packet.
    */
   static int
   ng_gif_glue_af(struct mbuf **mp, int af)
   {
           struct mbuf *m = *mp;
           int error = 0;
           sa_family_t tmp_af;
   
           tmp_af = (sa_family_t) af;
   
           /*
            * XXX: should try to bring back some of the optimizations from
            * ng_ether.c
            */
   
           /*
            * Doing anything more is likely to get more
            * expensive than it's worth..
            * it's probable that everything else is in one
            * big lump. The next node will do an m_pullup()
            * for exactly the amount of data it needs and
            * hopefully everything after that will not
            * need one. So let's just use M_PREPEND.
            */
           M_PREPEND(m, sizeof (tmp_af), M_DONTWAIT);
           if (m == NULL) {
                   error = ENOBUFS;
                   goto done;
           }
   
   #if 0
   copy:
   #endif
           /* Copy header and return (possibly new) mbuf */
           *mtod(m, sa_family_t *) = tmp_af;
   #if 0
           bcopy((caddr_t)&tmp_af, mtod(m, sa_family_t *), sizeof(tmp_af));
   #endif
   done:
           *mp = m;
           return error;
   }
   
   /******************************************************************
                       NETGRAPH NODE METHODS
   ******************************************************************/
   
   /*
    * It is not possible or allowable to create a node of this type.
    * Nodes get created when the interface is attached (or, when
    * this node type's KLD is loaded).
    */
   static int
   ng_gif_constructor(node_p node)
   {
           return (EINVAL);
   }
   
   /*
    * Check for attaching a new hook.
    */
   static  int
   ng_gif_newhook(node_p node, hook_p hook, const char *name)
   {
           const priv_p priv = NG_NODE_PRIVATE(node);
           u_char orphan = priv->lowerOrphan;
           hook_p *hookptr;
   
           /* Divert hook is an alias for lower */
           if (strcmp(name, NG_GIF_HOOK_DIVERT) == 0)
                   name = NG_GIF_HOOK_LOWER;
   
           /* Which hook? */
           if (strcmp(name, NG_GIF_HOOK_LOWER) == 0) {
                   hookptr = &priv->lower;
                   orphan = 0;
           } else if (strcmp(name, NG_GIF_HOOK_ORPHAN) == 0) {
                   hookptr = &priv->lower;
                   orphan = 1;
           } else
                   return (EINVAL);
   
           /* Check if already connected (shouldn't be, but doesn't hurt) */
           if (*hookptr != NULL)
                   return (EISCONN);
   
           /* OK */
           *hookptr = hook;
           priv->lowerOrphan = orphan;
           return (0);
   }
   
   /*
    * Hooks are attached, adjust to force queueing.
    * We don't really care which hook it is.
    * they should all be queuing for outgoing data.
    */
   static  int
   ng_gif_connect(hook_p hook)
   {
           NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook));
           return (0);
   }
   
   /*
    * Receive an incoming control message.
    */
   static int
   ng_gif_rcvmsg(node_p node, item_p item, hook_p lasthook)
   {
           const priv_p priv = NG_NODE_PRIVATE(node);
           struct ng_mesg *resp = NULL;
           int error = 0;
           struct ng_mesg *msg;
   
           NGI_GET_MSG(item, msg);
           switch (msg->header.typecookie) {
           case NGM_GIF_COOKIE:
                   switch (msg->header.cmd) {
                   case NGM_GIF_GET_IFNAME:
                           NG_MKRESPONSE(resp, msg, IFNAMSIZ + 1, M_NOWAIT);
                           if (resp == NULL) {
                                   error = ENOMEM;
                                   break;
                           }
                           strlcpy(resp->data, priv->ifp->if_xname, IFNAMSIZ + 1);
                           break;
                   case NGM_GIF_GET_IFINDEX:
                           NG_MKRESPONSE(resp, msg, sizeof(u_int32_t), M_NOWAIT);
                           if (resp == NULL) {
                                   error = ENOMEM;
                                   break;
                           }
                           *((u_int32_t *)resp->data) = priv->ifp->if_index;
                           break;
                   default:
                           error = EINVAL;
                           break;
                   }
                   break;
           default:
                   error = EINVAL;
                   break;
           }
           NG_RESPOND_MSG(error, node, item, resp);
           NG_FREE_MSG(msg);
           return (error);
   }
   
   /*
    * Receive data on a hook.
    */
   static int
   ng_gif_rcvdata(hook_p hook, item_p item)
   {
           const node_p node = NG_HOOK_NODE(hook);
           const priv_p priv = NG_NODE_PRIVATE(node);
           struct mbuf *m;
   
           NGI_GET_M(item, m);
           NG_FREE_ITEM(item);
   
           if (hook == priv->lower)
                   return ng_gif_rcv_lower(node, m);
           panic("%s: weird hook", __func__);
   }
   
   /*
    * Handle an mbuf received on the "lower" hook.
    */
   static int
   ng_gif_rcv_lower(node_p node, struct mbuf *m)
   {
           struct sockaddr dst;
           const priv_p priv = NG_NODE_PRIVATE(node);
   
           bzero(&dst, sizeof(dst));
   
           /* Make sure header is fully pulled up */
           if (m->m_pkthdr.len < sizeof(sa_family_t)) {
                   NG_FREE_M(m);
                   return (EINVAL);
           }
           if (m->m_len < sizeof(sa_family_t)
               && (m = m_pullup(m, sizeof(sa_family_t))) == NULL) {
                   return (ENOBUFS);
           }
   
           dst.sa_family = *mtod(m, sa_family_t *);
           m_adj(m, sizeof(sa_family_t));
   
           /* Send it on its way */
           /*
            * XXX: gif_output only uses dst for the family and passes the
            * fourth argument (rt) to in{,6}_gif_output which ignore it.
            * If this changes ng_gif will probably break.
            */
           return gif_output(priv->ifp, m, &dst, NULL);
   }
   
   /*
    * Shutdown node. This resets the node but does not remove it
    * unless the REALLY_DIE flag is set.
    */
   static int
   ng_gif_shutdown(node_p node)
   {
           const priv_p priv = NG_NODE_PRIVATE(node);
   
           if (node->nd_flags & NGF_REALLY_DIE) {
                   /*
                    * WE came here because the gif interface is being destroyed,
                    * so stop being persistant.
                    * Actually undo all the things we did on creation.
                    * Assume the ifp has already been freed.
                    */
                   NG_NODE_SET_PRIVATE(node, NULL);
                   FREE(priv, M_NETGRAPH);         
                   NG_NODE_UNREF(node);    /* free node itself */
                   return (0);
           }
           NG_NODE_REVIVE(node);           /* Signal ng_rmnode we are persisant */
           return (0);
   }
   
   /*
    * Hook disconnection.
    */
   static int
   ng_gif_disconnect(hook_p hook)
   {
           const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
   
           if (hook == priv->lower) {
                   priv->lower = NULL;
                   priv->lowerOrphan = 0;
           } else 
                   panic("%s: weird hook", __func__);
           if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
               && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
                   ng_rmnode_self(NG_HOOK_NODE(hook));     /* reset node */
   
           return (0);
   }
   
   /******************************************************************
                           INITIALIZATION
   ******************************************************************/
   
   /*
    * Handle loading and unloading for this node type.
    */
   static int
   ng_gif_mod_event(module_t mod, int event, void *data)
   {
           struct ifnet *ifp;
           int error = 0;
           int s;
   
           s = splnet();
           switch (event) {
           case MOD_LOAD:
   
                   /* Register function hooks */
                   if (ng_gif_attach_p != NULL) {
                           error = EEXIST;
                           break;
                   }
                   ng_gif_attach_p = ng_gif_attach;
                   ng_gif_detach_p = ng_gif_detach;
                   ng_gif_input_p = ng_gif_input;
                   ng_gif_input_orphan_p = ng_gif_input_orphan;
   
                   /* Create nodes for any already-existing gif interfaces */
                   IFNET_RLOCK();
                   TAILQ_FOREACH(ifp, &ifnet, if_link) {
                           if (ifp->if_type == IFT_GIF)
                                   ng_gif_attach(ifp);
                   }
                   IFNET_RUNLOCK();
                   break;
   
           case MOD_UNLOAD:
   
                   /*
                    * Note that the base code won't try to unload us until
                    * all nodes have been removed, and that can't happen
                    * until all gif interfaces are destroyed. In any
                    * case, we know there are no nodes left if the action
                    * is MOD_UNLOAD, so there's no need to detach any nodes.
                    *
                    * XXX: what about manual unloads?!?
                    */
   
                   /* Unregister function hooks */
                   ng_gif_attach_p = NULL;
                   ng_gif_detach_p = NULL;
                   ng_gif_input_p = NULL;
                   ng_gif_input_orphan_p = NULL;
                   break;
   
           default:
                   error = EOPNOTSUPP;
                   break;
           }
           splx(s);
           return (error);
   }
   

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