sys/netgraph/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  * $Whistle: ng_hole.c,v 1.10 1999/11/01 09:24:51 julian Exp $
  40  */
  41
  42 /*
  43  * This node is a 'black hole' that simply discards everything it receives
  44  */
  45
  46 #include <sys/param.h>
  47 #include <sys/systm.h>
  48 #include <sys/kernel.h>
  49 #include <sys/malloc.h>
  50 #include <sys/mbuf.h>
  51 #include <netgraph/ng_message.h>
  52 #include <netgraph/netgraph.h>
  53 #include <netgraph/ng_parse.h>
  54 #include <netgraph/ng_hole.h>
  55
  56 /* Per hook private info. */
  57 struct ng_hole_hookinfo {
  58         struct ng_hole_hookstat stats;
  59 };
  60 typedef struct ng_hole_hookinfo *hinfo_p;
  61
  62 /* Parse type for struct ng_hole_hookstat. */
  63 static const struct ng_parse_struct_field ng_hole_hookstat_type_fields[] =
  64         NG_HOLE_HOOKSTAT_TYPE_INFO;
  65 static const struct ng_parse_type ng_hole_hookstat_type = {
  66         &ng_parse_struct_type,
  67         &ng_hole_hookstat_type_fields
  68 };
  69
  70 /* List of commands and how to convert arguments to/from ASCII. */
  71 static const struct ng_cmdlist ng_hole_cmdlist[] = {
  72         {
  73           NGM_HOLE_COOKIE,
  74           NGM_HOLE_GET_STATS,
  75           "getstats",
  76           &ng_parse_hookbuf_type,
  77           &ng_hole_hookstat_type
  78         },
  79         {
  80           NGM_HOLE_COOKIE,
  81           NGM_HOLE_CLR_STATS,
  82           "clrstats",
  83           &ng_parse_hookbuf_type,
  84           NULL
  85         },
  86         {
  87           NGM_HOLE_COOKIE,
  88           NGM_HOLE_GETCLR_STATS,
  89           "getclrstats",
  90           &ng_parse_hookbuf_type,
  91           &ng_hole_hookstat_type
  92         },
  93         { 0 }
  94 };
  95
  96 /* Netgraph methods */
  97 static ng_constructor_t ngh_cons;
  98 static ng_rcvmsg_t      ngh_rcvmsg;
  99 static ng_newhook_t     ngh_newhook;
 100 static ng_rcvdata_t     ngh_rcvdata;
 101 static ng_disconnect_t  ngh_disconnect;
 102
 103 static struct ng_type typestruct = {
 104         .version =      NG_ABI_VERSION,
 105         .name =         NG_HOLE_NODE_TYPE,
 106         .constructor =  ngh_cons,
 107         .rcvmsg =       ngh_rcvmsg,
 108         .newhook =      ngh_newhook,
 109         .rcvdata =      ngh_rcvdata,
 110         .disconnect =   ngh_disconnect,
 111         .cmdlist =      ng_hole_cmdlist,
 112 };
 113 NETGRAPH_INIT(hole, &typestruct);
 114
 115 /*
 116  * Be obliging. but no work to do.
 117  */
 118 static int
 119 ngh_cons(node_p node)
 120 {
 121         return(0);
 122 }
 123
 124 /*
 125  * Add a hook.
 126  */
 127 static int
 128 ngh_newhook(node_p node, hook_p hook, const char *name)
 129 {
 130         hinfo_p hip;
 131
 132         /* Create hook private structure. */
 133         hip = malloc(sizeof(*hip), M_NETGRAPH, M_NOWAIT | M_ZERO);
 134         if (hip == NULL)
 135                 return (ENOMEM);
 136         NG_HOOK_SET_PRIVATE(hook, hip);
 137         return (0);
 138 }
 139
 140 /*
 141  * Receive a control message.
 142  */
 143 static int
 144 ngh_rcvmsg(node_p node, item_p item, hook_p lasthook)
 145 {
 146         struct ng_mesg *msg;
 147         struct ng_mesg *resp = NULL;
 148         int error = 0;
 149         struct ng_hole_hookstat *stats;
 150         hook_p hook;
 151
 152         NGI_GET_MSG(item, msg);
 153         switch (msg->header.typecookie) {
 154         case NGM_HOLE_COOKIE:
 155                 switch (msg->header.cmd) {
 156                 case NGM_HOLE_GET_STATS:
 157                 case NGM_HOLE_CLR_STATS:
 158                 case NGM_HOLE_GETCLR_STATS:
 159                         /* Sanity check. */
 160                         if (msg->header.arglen != NG_HOOKSIZ) {
 161                                 error = EINVAL;
 162                                 break;
 163                         }
 164                         /* Find hook. */
 165                         hook = ng_findhook(node, (char *)msg->data);
 166                         if (hook == NULL) {
 167                                 error = ENOENT;
 168                                 break;
 169                         }
 170                         stats = &((hinfo_p)NG_HOOK_PRIVATE(hook))->stats;
 171                         /* Build response (if desired). */
 172                         if (msg->header.cmd != NGM_HOLE_CLR_STATS) {
 173                                 NG_MKRESPONSE(resp, msg, sizeof(*stats),
 174                                     M_NOWAIT);
 175                                 if (resp == NULL) {
 176                                         error = ENOMEM;
 177                                         break;
 178                                 }
 179                                 bcopy(stats, resp->data, sizeof(*stats));
 180                         }
 181                         /* Clear stats (if desired). */
 182                         if (msg->header.cmd != NGM_HOLE_GET_STATS)
 183                                 bzero(stats, sizeof(*stats));
 184                         break;
 185                 default:                /* Unknown command. */
 186                         error = EINVAL;
 187                         break;
 188                 }
 189                 break;
 190         default:                        /* Unknown type cookie. */
 191                 error = EINVAL;
 192                 break;
 193         }
 194         NG_RESPOND_MSG(error, node, item, resp);
 195         NG_FREE_MSG(msg);
 196         return (error);
 197 }
 198
 199 /*
 200  * Receive data
 201  */
 202 static int
 203 ngh_rcvdata(hook_p hook, item_p item)
 204 {
 205         const hinfo_p hip = NG_HOOK_PRIVATE(hook);
 206
 207         hip->stats.frames++;
 208         hip->stats.octets += NGI_M(item)->m_pkthdr.len;
 209         NG_FREE_ITEM(item);
 210         return 0;
 211 }
 212
 213 /*
 214  * Hook disconnection
 215  */
 216 static int
 217 ngh_disconnect(hook_p hook)
 218 {
 219
 220         free(NG_HOOK_PRIVATE(hook), M_NETGRAPH);
 221         NG_HOOK_SET_PRIVATE(hook, NULL);
 222         if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
 223                 ng_rmnode_self(NG_HOOK_NODE(hook));
 224         return (0);
 225 }