sys/netgraph/ng_tee.c

   1
   2 /*
   3  * ng_tee.c
   4  *
   5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
   6  * All rights reserved.
   7  *
   8  * Subject to the following obligations and disclaimer of warranty, use and
   9  * redistribution of this software, in source or object code forms, with or
  10  * without modifications are expressly permitted by Whistle Communications;
  11  * provided, however, that:
  12  * 1. Any and all reproductions of the source or object code must include the
  13  *    copyright notice above and the following disclaimer of warranties; and
  14  * 2. No rights are granted, in any manner or form, to use Whistle
  15  *    Communications, Inc. trademarks, including the mark "WHISTLE
  16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
  17  *    such appears in the above copyright notice or in the software.
  18  *
  19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
  20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
  21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
  22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
  23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
  24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
  25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
  26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
  27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
  28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
  29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
  30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
  31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
  32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
  35  * OF SUCH DAMAGE.
  36  *
  37  * Author: Julian Elischer <julian@freebsd.org>
  38  *
  39  * $FreeBSD$
  40  * $Whistle: ng_tee.c,v 1.18 1999/11/01 09:24:52 julian Exp $
  41  */
  42
  43 /*
  44  * This node is like the tee(1) command and is useful for ``snooping.''
  45  * It has 4 hooks: left, right, left2right, and right2left. Data
  46  * entering from the right is passed to the left and duplicated on
  47  * right2left, and data entering from the left is passed to the right
  48  * and duplicated on left2right. Data entering from left2right is
  49  * sent to left, and data from right2left to right.
  50  */
  51
  52 #include <sys/param.h>
  53 #include <sys/systm.h>
  54 #include <sys/errno.h>
  55 #include <sys/kernel.h>
  56 #include <sys/malloc.h>
  57 #include <sys/mbuf.h>
  58 #include <netgraph/ng_message.h>
  59 #include <netgraph/netgraph.h>
  60 #include <netgraph/ng_parse.h>
  61 #include <netgraph/ng_tee.h>
  62
  63 /* Per hook info */
  64 struct hookinfo {
  65         hook_p                  hook;
  66         struct ng_tee_hookstat  stats;
  67 };
  68
  69 /* Per node info */
  70 struct privdata {
  71         node_p                  node;
  72         struct hookinfo         left;
  73         struct hookinfo         right;
  74         struct hookinfo         left2right;
  75         struct hookinfo         right2left;
  76 };
  77 typedef struct privdata *sc_p;
  78
  79 /* Netgraph methods */
  80 static ng_constructor_t ngt_constructor;
  81 static ng_rcvmsg_t      ngt_rcvmsg;
  82 static ng_shutdown_t    ngt_shutdown;
  83 static ng_newhook_t     ngt_newhook;
  84 static ng_rcvdata_t     ngt_rcvdata;
  85 static ng_disconnect_t  ngt_disconnect;
  86
  87 /* Parse type for struct ng_tee_hookstat */
  88 static const struct ng_parse_struct_field ng_tee_hookstat_type_fields[]
  89         = NG_TEE_HOOKSTAT_INFO;
  90 static const struct ng_parse_type ng_tee_hookstat_type = {
  91         &ng_parse_struct_type,
  92         &ng_tee_hookstat_type_fields
  93 };
  94
  95 /* Parse type for struct ng_tee_stats */
  96 static const struct ng_parse_struct_field ng_tee_stats_type_fields[]
  97         = NG_TEE_STATS_INFO(&ng_tee_hookstat_type);
  98 static const struct ng_parse_type ng_tee_stats_type = {
  99         &ng_parse_struct_type,
 100         &ng_tee_stats_type_fields
 101 };
 102
 103 /* List of commands and how to convert arguments to/from ASCII */
 104 static const struct ng_cmdlist ng_tee_cmds[] = {
 105         {
 106           NGM_TEE_COOKIE,
 107           NGM_TEE_GET_STATS,
 108           "getstats",
 109           NULL,
 110           &ng_tee_stats_type
 111         },
 112         {
 113           NGM_TEE_COOKIE,
 114           NGM_TEE_CLR_STATS,
 115           "clrstats",
 116           NULL,
 117           NULL
 118         },
 119         {
 120           NGM_TEE_COOKIE,
 121           NGM_TEE_GETCLR_STATS,
 122           "getclrstats",
 123           NULL,
 124           &ng_tee_stats_type
 125         },
 126         { 0 }
 127 };
 128
 129 /* Netgraph type descriptor */
 130 static struct ng_type ng_tee_typestruct = {
 131         NG_ABI_VERSION,
 132         NG_TEE_NODE_TYPE,
 133         NULL,
 134         ngt_constructor,
 135         ngt_rcvmsg,
 136         ngt_shutdown,
 137         ngt_newhook,
 138         NULL,
 139         NULL,
 140         ngt_rcvdata,
 141         ngt_disconnect,
 142         ng_tee_cmds
 143 };
 144 NETGRAPH_INIT(tee, &ng_tee_typestruct);
 145
 146 /*
 147  * Node constructor
 148  */
 149 static int
 150 ngt_constructor(node_p node)
 151 {
 152         sc_p privdata;
 153
 154         MALLOC(privdata, sc_p, sizeof(*privdata), M_NETGRAPH, M_NOWAIT|M_ZERO);
 155         if (privdata == NULL)
 156                 return (ENOMEM);
 157
 158         NG_NODE_SET_PRIVATE(node, privdata);
 159         privdata->node = node;
 160         return (0);
 161 }
 162
 163 /*
 164  * Add a hook
 165  */
 166 static int
 167 ngt_newhook(node_p node, hook_p hook, const char *name)
 168 {
 169         const sc_p sc = NG_NODE_PRIVATE(node);
 170
 171         if (strcmp(name, NG_TEE_HOOK_RIGHT) == 0) {
 172                 sc->right.hook = hook;
 173                 bzero(&sc->right.stats, sizeof(sc->right.stats));
 174                 NG_HOOK_SET_PRIVATE(hook, &sc->right);
 175         } else if (strcmp(name, NG_TEE_HOOK_LEFT) == 0) {
 176                 sc->left.hook = hook;
 177                 bzero(&sc->left.stats, sizeof(sc->left.stats));
 178                 NG_HOOK_SET_PRIVATE(hook, &sc->left);
 179         } else if (strcmp(name, NG_TEE_HOOK_RIGHT2LEFT) == 0) {
 180                 sc->right2left.hook = hook;
 181                 bzero(&sc->right2left.stats, sizeof(sc->right2left.stats));
 182                 NG_HOOK_SET_PRIVATE(hook, &sc->right2left);
 183         } else if (strcmp(name, NG_TEE_HOOK_LEFT2RIGHT) == 0) {
 184                 sc->left2right.hook = hook;
 185                 bzero(&sc->left2right.stats, sizeof(sc->left2right.stats));
 186                 NG_HOOK_SET_PRIVATE(hook, &sc->left2right);
 187         } else
 188                 return (EINVAL);
 189         return (0);
 190 }
 191
 192 /*
 193  * Receive a control message
 194  */
 195 static int
 196 ngt_rcvmsg(node_p node, item_p item, hook_p lasthook)
 197 {
 198         const sc_p sc = NG_NODE_PRIVATE(node);
 199         struct ng_mesg *resp = NULL;
 200         int error = 0;
 201         struct ng_mesg *msg;
 202
 203         NGI_GET_MSG(item, msg);
 204         switch (msg->header.typecookie) {
 205         case NGM_TEE_COOKIE:
 206                 switch (msg->header.cmd) {
 207                 case NGM_TEE_GET_STATS:
 208                 case NGM_TEE_CLR_STATS:
 209                 case NGM_TEE_GETCLR_STATS:
 210                     {
 211                         struct ng_tee_stats *stats;
 212
 213                         if (msg->header.cmd != NGM_TEE_CLR_STATS) {
 214                                 NG_MKRESPONSE(resp, msg,
 215                                     sizeof(*stats), M_NOWAIT);
 216                                 if (resp == NULL) {
 217                                         error = ENOMEM;
 218                                         goto done;
 219                                 }
 220                                 stats = (struct ng_tee_stats *)resp->data;
 221                                 bcopy(&sc->right.stats, &stats->right,
 222                                     sizeof(stats->right));
 223                                 bcopy(&sc->left.stats, &stats->left,
 224                                     sizeof(stats->left));
 225                                 bcopy(&sc->right2left.stats, &stats->right2left,
 226                                     sizeof(stats->right2left));
 227                                 bcopy(&sc->left2right.stats, &stats->left2right,
 228                                     sizeof(stats->left2right));
 229                         }
 230                         if (msg->header.cmd != NGM_TEE_GET_STATS) {
 231                                 bzero(&sc->right.stats,
 232                                     sizeof(sc->right.stats));
 233                                 bzero(&sc->left.stats,
 234                                     sizeof(sc->left.stats));
 235                                 bzero(&sc->right2left.stats,
 236                                     sizeof(sc->right2left.stats));
 237                                 bzero(&sc->left2right.stats,
 238                                     sizeof(sc->left2right.stats));
 239                         }
 240                         break;
 241                     }
 242                 default:
 243                         error = EINVAL;
 244                         break;
 245                 }
 246                 break;
 247         case NGM_FLOW_COOKIE:
 248                 if (lasthook)  {
 249                         if (lasthook == sc->left.hook) {
 250                                 if (sc->right.hook) {
 251                                         NGI_MSG(item) = msg;
 252                                         NG_FWD_ITEM_HOOK(error, item,
 253                                                         sc->right.hook);
 254                                         return (error);
 255                                 }
 256                         } else {
 257                                 if (sc->left.hook) {
 258                                         NGI_MSG(item) = msg;
 259                                         NG_FWD_ITEM_HOOK(error, item,
 260                                                         sc->left.hook);
 261                                         return (error);
 262                                 }
 263                         }
 264                 }
 265                 break;
 266         default:
 267                 error = EINVAL;
 268                 break;
 269         }
 270 done:
 271         NG_RESPOND_MSG(error, node, item, resp);
 272         NG_FREE_MSG(msg);
 273         return (error);
 274 }
 275
 276 /*
 277  * Receive data on a hook
 278  *
 279  * If data comes in the right link send a copy out right2left, and then
 280  * send the original onwards out through the left link.
 281  * Do the opposite for data coming in from the left link.
 282  * Data coming in right2left or left2right is forwarded
 283  * on through the appropriate destination hook as if it had come
 284  * from the other side.
 285  */
 286 static int
 287 ngt_rcvdata(hook_p hook, item_p item)
 288 {
 289         const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 290         struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
 291         struct hookinfo *dest;
 292         struct hookinfo *dup;
 293         int error = 0;
 294         struct mbuf *m;
 295         meta_p meta;
 296
 297         m = NGI_M(item);
 298         meta = NGI_META(item); /* leave these owned by the item */
 299         /* Which hook? */
 300         if (hinfo == &sc->left) {
 301                 dup = &sc->left2right;
 302                 dest = &sc->right;
 303         } else if (hinfo == &sc->right) {
 304                 dup = &sc->right2left;
 305                 dest = &sc->left;
 306         } else if (hinfo == &sc->right2left) {
 307                 dup = NULL;
 308                 dest = &sc->right;
 309         } else if (hinfo == &sc->left2right) {
 310                 dup = NULL;
 311                 dest = &sc->left;
 312         } else {
 313                 panic("%s: no hook!", __func__);
 314 #ifdef  RESTARTABLE_PANICS
 315                 return(EINVAL);
 316 #endif
 317         }
 318
 319         /* Update stats on incoming hook */
 320         hinfo->stats.inOctets += m->m_pkthdr.len;
 321         hinfo->stats.inFrames++;
 322
 323         /*
 324          * Don't make a copy if only the dup hook exists.
 325          */
 326         if ((dup && dup->hook) && (dest->hook == NULL)) {
 327                 dest = dup;
 328                 dup = NULL;
 329         }
 330
 331         /* Duplicate packet and meta info if requried */
 332         if (dup != NULL) {
 333                 struct mbuf *m2;
 334                 meta_p meta2;
 335
 336                 /* Copy packet (failure will not stop the original)*/
 337                 m2 = m_dup(m, M_DONTWAIT);
 338                 if (m2) {
 339
 340                         /* Copy meta info */
 341                         /* If we can't get a copy, tough.. */
 342                         if (meta != NULL) {
 343                                 meta2 = ng_copy_meta(meta);
 344                         } else
 345                                 meta2 = NULL;
 346
 347                         /* Deliver duplicate */
 348                         dup->stats.outOctets += m->m_pkthdr.len;
 349                         dup->stats.outFrames++;
 350                         NG_SEND_DATA(error, dup->hook, m2, meta2);
 351                 }
 352         }
 353         /* Deliver frame out destination hook */
 354         dest->stats.outOctets += m->m_pkthdr.len;
 355         dest->stats.outFrames++;
 356         if (dest->hook)
 357                 NG_FWD_ITEM_HOOK(error, item, dest->hook);
 358         else
 359                 NG_FREE_ITEM(item);
 360         return (error);
 361 }
 362
 363 /*
 364  * Shutdown processing
 365  *
 366  * This is tricky. If we have both a left and right hook, then we
 367  * probably want to extricate ourselves and leave the two peers
 368  * still linked to each other. Otherwise we should just shut down as
 369  * a normal node would.
 370  *
 371  * To keep the scope of info correct the routine to "extract" a node
 372  * from two links is in ng_base.c.
 373  */
 374 static int
 375 ngt_shutdown(node_p node)
 376 {
 377         const sc_p privdata = NG_NODE_PRIVATE(node);
 378
 379 #if 0 /* can never happen as cutlinks is already called */
 380         if (privdata->left.hook && privdata->right.hook)
 381                 ng_bypass(privdata->left.hook, privdata->right.hook);
 382 #endif
 383         NG_NODE_SET_PRIVATE(node, NULL);
 384         NG_NODE_UNREF(privdata->node);
 385         FREE(privdata, M_NETGRAPH);
 386         return (0);
 387 }
 388
 389 /*
 390  * Hook disconnection
 391  */
 392 static int
 393 ngt_disconnect(hook_p hook)
 394 {
 395         struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
 396
 397         KASSERT(hinfo != NULL, ("%s: null info", __func__));
 398         hinfo->hook = NULL;
 399         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
 400         && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
 401                 ng_rmnode_self(NG_HOOK_NODE(hook));
 402         return (0);
 403 }
 404