sys/netgraph7/ng_hole.c

   1 /*
   2  * ng_hole.c
   3  */
   4
   5 /*-
   6  * Copyright (c) 1996-1999 Whistle Communications, Inc.
   7  * All rights reserved.
   8  *
   9  * Subject to the following obligations and disclaimer of warranty, use and
  10  * redistribution of this software, in source or object code forms, with or
  11  * without modifications are expressly permitted by Whistle Communications;
  12  * provided, however, that:
  13  * 1. Any and all reproductions of the source or object code must include the
  14  *    copyright notice above and the following disclaimer of warranties; and
  15  * 2. No rights are granted, in any manner or form, to use Whistle
  16  *    Communications, Inc. trademarks, including the mark "WHISTLE
  17  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
  18  *    such appears in the above copyright notice or in the software.
  19  *
  20  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
  21  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
  22  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
  23  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
  24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
  25  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
  26  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
  27  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
  28  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
  29  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
  30  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
  31  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
  32  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  35  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
  36  * OF SUCH DAMAGE.
  37  *
  38  * Author: Julian Elisher <julian@freebsd.org>
  39  *
  40  * $FreeBSD: src/sys/netgraph/ng_hole.c,v 1.15 2005/12/09 07:09:44 ru Exp $
  41  * $Whistle: ng_hole.c,v 1.10 1999/11/01 09:24:51 julian Exp $
  42  */
  43
  44 /*
  45  * This node is a 'black hole' that simply discards everything it receives
  46  */
  47
  48 #include <sys/param.h>
  49 #include <sys/systm.h>
  50 #include <sys/kernel.h>
  51 #include <sys/malloc.h>
  52 #include <sys/mbuf.h>
  53 #include <netgraph/ng_message.h>
  54 #include <netgraph/netgraph.h>
  55 #include <netgraph/ng_parse.h>
  56 #include <netgraph/ng_hole.h>
  57
  58 /* Per hook private info. */
  59 struct ng_hole_hookinfo {
  60         struct ng_hole_hookstat stats;
  61 };
  62 typedef struct ng_hole_hookinfo *hinfo_p;
  63
  64 /* Parse type for struct ng_hole_hookstat. */
  65 static const struct ng_parse_struct_field ng_hole_hookstat_type_fields[] =
  66         NG_HOLE_HOOKSTAT_TYPE_INFO;
  67 static const struct ng_parse_type ng_hole_hookstat_type = {
  68         &ng_parse_struct_type,
  69         &ng_hole_hookstat_type_fields
  70 };
  71
  72 /* List of commands and how to convert arguments to/from ASCII. */
  73 static const struct ng_cmdlist ng_hole_cmdlist[] = {
  74         {
  75           NGM_HOLE_COOKIE,
  76           NGM_HOLE_GET_STATS,
  77           "getstats",
  78           &ng_parse_hookbuf_type,
  79           &ng_hole_hookstat_type
  80         },
  81         {
  82           NGM_HOLE_COOKIE,
  83           NGM_HOLE_CLR_STATS,
  84           "clrstats",
  85           &ng_parse_hookbuf_type,
  86           NULL
  87         },
  88         {
  89           NGM_HOLE_COOKIE,
  90           NGM_HOLE_GETCLR_STATS,
  91           "getclrstats",
  92           &ng_parse_hookbuf_type,
  93           &ng_hole_hookstat_type
  94         },
  95         { 0 }
  96 };
  97
  98 /* Netgraph methods */
  99 static ng_constructor_t ngh_cons;
 100 static ng_rcvmsg_t      ngh_rcvmsg;
 101 static ng_newhook_t     ngh_newhook;
 102 static ng_rcvdata_t     ngh_rcvdata;
 103 static ng_disconnect_t  ngh_disconnect;
 104
 105 static struct ng_type typestruct = {
 106         .version =      NG_ABI_VERSION,
 107         .name =         NG_HOLE_NODE_TYPE,
 108         .constructor =  ngh_cons,
 109         .rcvmsg =       ngh_rcvmsg,
 110         .newhook =      ngh_newhook,
 111         .rcvdata =      ngh_rcvdata,
 112         .disconnect =   ngh_disconnect,
 113         .cmdlist =      ng_hole_cmdlist,
 114 };
 115 NETGRAPH_INIT(hole, &typestruct);
 116
 117 /*
 118  * Be obliging. but no work to do.
 119  */
 120 static int
 121 ngh_cons(node_p node)
 122 {
 123         return(0);
 124 }
 125
 126 /*
 127  * Add a hook.
 128  */
 129 static int
 130 ngh_newhook(node_p node, hook_p hook, const char *name)
 131 {
 132         hinfo_p hip;
 133
 134         /* Create hook private structure. */
 135         MALLOC(hip, hinfo_p, sizeof(*hip), M_NETGRAPH, M_NOWAIT | M_ZERO);
 136         if (hip == NULL)
 137                 return (ENOMEM);
 138         NG_HOOK_SET_PRIVATE(hook, hip);
 139         return (0);
 140 }
 141
 142 /*
 143  * Receive a control message.
 144  */
 145 static int
 146 ngh_rcvmsg(node_p node, item_p item, hook_p lasthook)
 147 {
 148         struct ng_mesg *msg;
 149         struct ng_mesg *resp = NULL;
 150         int error = 0;
 151         struct ng_hole_hookstat *stats;
 152         hook_p hook;
 153
 154         NGI_GET_MSG(item, msg);
 155         switch (msg->header.typecookie) {
 156         case NGM_HOLE_COOKIE:
 157                 switch (msg->header.cmd) {
 158                 case NGM_HOLE_GET_STATS:
 159                 case NGM_HOLE_CLR_STATS:
 160                 case NGM_HOLE_GETCLR_STATS:
 161                         /* Sanity check. */
 162                         if (msg->header.arglen != NG_HOOKSIZ) {
 163                                 error = EINVAL;
 164                                 break;
 165                         }
 166                         /* Find hook. */
 167                         hook = ng_findhook(node, (char *)msg->data);
 168                         if (hook == NULL) {
 169                                 error = ENOENT;
 170                                 break;
 171                         }
 172                         stats = &((hinfo_p)NG_HOOK_PRIVATE(hook))->stats;
 173                         /* Build response (if desired). */
 174                         if (msg->header.cmd != NGM_HOLE_CLR_STATS) {
 175                                 NG_MKRESPONSE(resp, msg, sizeof(*stats),
 176                                     M_NOWAIT);
 177                                 if (resp == NULL) {
 178                                         error = ENOMEM;
 179                                         break;
 180                                 }
 181                                 bcopy(stats, resp->data, sizeof(*stats));
 182                         }
 183                         /* Clear stats (if desired). */
 184                         if (msg->header.cmd != NGM_HOLE_GET_STATS)
 185                                 bzero(stats, sizeof(*stats));
 186                         break;
 187                 default:                /* Unknown command. */
 188                         error = EINVAL;
 189                         break;
 190                 }
 191                 break;
 192         default:                        /* Unknown type cookie. */
 193                 error = EINVAL;
 194                 break;
 195         }
 196         NG_RESPOND_MSG(error, node, item, resp);
 197         NG_FREE_MSG(msg);
 198         return (error);
 199 }
 200
 201 /*
 202  * Receive data
 203  */
 204 static int
 205 ngh_rcvdata(hook_p hook, item_p item)
 206 {
 207         const hinfo_p hip = NG_HOOK_PRIVATE(hook);
 208
 209         hip->stats.frames++;
 210         hip->stats.octets += NGI_M(item)->m_pkthdr.len;
 211         NG_FREE_ITEM(item);
 212         return 0;
 213 }
 214
 215 /*
 216  * Hook disconnection
 217  */
 218 static int
 219 ngh_disconnect(hook_p hook)
 220 {
 221
 222         FREE(NG_HOOK_PRIVATE(hook), M_NETGRAPH);
 223         NG_HOOK_SET_PRIVATE(hook, NULL);
 224         if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
 225                 ng_rmnode_self(NG_HOOK_NODE(hook));
 226         return (0);
 227 }