sys/netgraph/ng_tee.c

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