sys/netgraph7/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: src/sys/netgraph/ng_tee.c,v 1.35 2008/02/24 10:13:32 mav Exp $
  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         MALLOC(privdata, sc_p, sizeof(*privdata), M_NETGRAPH, M_NOWAIT|M_ZERO);
 157         if (privdata == NULL)
 158                 return (ENOMEM);
 159
 160         NG_NODE_SET_PRIVATE(node, privdata);
 161         return (0);
 162 }
 163
 164 /*
 165  * Add a hook
 166  */
 167 static int
 168 ng_tee_newhook(node_p node, hook_p hook, const char *name)
 169 {
 170         sc_p    privdata = NG_NODE_PRIVATE(node);
 171         hi_p    hinfo;
 172
 173         /* Precalculate internal pathes. */
 174         if (strcmp(name, NG_TEE_HOOK_RIGHT) == 0) {
 175                 hinfo = &privdata->right;
 176                 if (privdata->left.dest)
 177                         privdata->left.dup = privdata->left.dest;
 178                 privdata->left.dest = hinfo;
 179                 privdata->right2left.dest = hinfo;
 180         } else if (strcmp(name, NG_TEE_HOOK_LEFT) == 0) {
 181                 hinfo = &privdata->left;
 182                 if (privdata->right.dest)
 183                         privdata->right.dup = privdata->right.dest;
 184                 privdata->right.dest = hinfo;
 185                 privdata->left2right.dest = hinfo;
 186         } else if (strcmp(name, NG_TEE_HOOK_RIGHT2LEFT) == 0) {
 187                 hinfo = &privdata->right2left;
 188                 if (privdata->right.dest)
 189                         privdata->right.dup = hinfo;
 190                 else
 191                         privdata->right.dest = hinfo;
 192         } else if (strcmp(name, NG_TEE_HOOK_LEFT2RIGHT) == 0) {
 193                 hinfo = &privdata->left2right;
 194                 if (privdata->left.dest)
 195                         privdata->left.dup = hinfo;
 196                 else
 197                         privdata->left.dest = hinfo;
 198         } else
 199                 return (EINVAL);
 200         hinfo->hook = hook;
 201         bzero(&hinfo->stats, sizeof(hinfo->stats));
 202         NG_HOOK_SET_PRIVATE(hook, hinfo);
 203         return (0);
 204 }
 205
 206 /*
 207  * Receive a control message
 208  */
 209 static int
 210 ng_tee_rcvmsg(node_p node, item_p item, hook_p lasthook)
 211 {
 212         const sc_p sc = NG_NODE_PRIVATE(node);
 213         struct ng_mesg *resp = NULL;
 214         int error = 0;
 215         struct ng_mesg *msg;
 216
 217         NGI_GET_MSG(item, msg);
 218         switch (msg->header.typecookie) {
 219         case NGM_TEE_COOKIE:
 220                 switch (msg->header.cmd) {
 221                 case NGM_TEE_GET_STATS:
 222                 case NGM_TEE_CLR_STATS:
 223                 case NGM_TEE_GETCLR_STATS:
 224                     {
 225                         struct ng_tee_stats *stats;
 226
 227                         if (msg->header.cmd != NGM_TEE_CLR_STATS) {
 228                                 NG_MKRESPONSE(resp, msg,
 229                                     sizeof(*stats), M_NOWAIT);
 230                                 if (resp == NULL) {
 231                                         error = ENOMEM;
 232                                         goto done;
 233                                 }
 234                                 stats = (struct ng_tee_stats *)resp->data;
 235                                 bcopy(&sc->right.stats, &stats->right,
 236                                     sizeof(stats->right));
 237                                 bcopy(&sc->left.stats, &stats->left,
 238                                     sizeof(stats->left));
 239                                 bcopy(&sc->right2left.stats, &stats->right2left,
 240                                     sizeof(stats->right2left));
 241                                 bcopy(&sc->left2right.stats, &stats->left2right,
 242                                     sizeof(stats->left2right));
 243                         }
 244                         if (msg->header.cmd != NGM_TEE_GET_STATS) {
 245                                 bzero(&sc->right.stats,
 246                                     sizeof(sc->right.stats));
 247                                 bzero(&sc->left.stats,
 248                                     sizeof(sc->left.stats));
 249                                 bzero(&sc->right2left.stats,
 250                                     sizeof(sc->right2left.stats));
 251                                 bzero(&sc->left2right.stats,
 252                                     sizeof(sc->left2right.stats));
 253                         }
 254                         break;
 255                     }
 256                 default:
 257                         error = EINVAL;
 258                         break;
 259                 }
 260                 break;
 261         case NGM_FLOW_COOKIE:
 262                 if (lasthook == sc->left.hook || lasthook == sc->right.hook)  {
 263                         hi_p const hinfo = NG_HOOK_PRIVATE(lasthook);
 264                         if (hinfo && hinfo->dest) {
 265                                 NGI_MSG(item) = msg;
 266                                 NG_FWD_ITEM_HOOK(error, item, hinfo->dest->hook);
 267                                 return (error);
 268                         }
 269                 }
 270                 break;
 271         default:
 272                 error = EINVAL;
 273                 break;
 274         }
 275 done:
 276         NG_RESPOND_MSG(error, node, item, resp);
 277         NG_FREE_MSG(msg);
 278         return (error);
 279 }
 280
 281 /*
 282  * Receive data on a hook
 283  *
 284  * If data comes in the right link send a copy out right2left, and then
 285  * send the original onwards out through the left link.
 286  * Do the opposite for data coming in from the left link.
 287  * Data coming in right2left or left2right is forwarded
 288  * on through the appropriate destination hook as if it had come
 289  * from the other side.
 290  */
 291 static int
 292 ng_tee_rcvdata(hook_p hook, item_p item)
 293 {
 294         const hi_p hinfo = NG_HOOK_PRIVATE(hook);
 295         hi_p    h;
 296         int     error = 0;
 297         struct mbuf *m;
 298
 299         m = NGI_M(item);
 300
 301         /* Update stats on incoming hook */
 302         hinfo->stats.inOctets += m->m_pkthdr.len;
 303         hinfo->stats.inFrames++;
 304
 305         /* Duplicate packet if requried */
 306         if (hinfo->dup) {
 307                 struct mbuf *m2;
 308
 309                 /* Copy packet (failure will not stop the original)*/
 310                 m2 = m_dup(m, M_DONTWAIT);
 311                 if (m2) {
 312                         /* Deliver duplicate */
 313                         h = hinfo->dup;
 314                         NG_SEND_DATA_ONLY(error, h->hook, m2);
 315                         if (error == 0) {
 316                                 h->stats.outOctets += m->m_pkthdr.len;
 317                                 h->stats.outFrames++;
 318                         }
 319                 }
 320         }
 321         /* Deliver frame out destination hook */
 322         if (hinfo->dest) {
 323                 h = hinfo->dest;
 324                 h->stats.outOctets += m->m_pkthdr.len;
 325                 h->stats.outFrames++;
 326                 NG_FWD_ITEM_HOOK(error, item, h->hook);
 327         } else
 328                 NG_FREE_ITEM(item);
 329         return (error);
 330 }
 331
 332 /*
 333  * We are going to be shut down soon
 334  *
 335  * If we have both a left and right hook, then we probably want to extricate
 336  * ourselves and leave the two peers still linked to each other. Otherwise we
 337  * should just shut down as a normal node would.
 338  */
 339 static int
 340 ng_tee_close(node_p node)
 341 {
 342         const sc_p privdata = NG_NODE_PRIVATE(node);
 343
 344         if (privdata->left.hook && privdata->right.hook)
 345                 ng_bypass(privdata->left.hook, privdata->right.hook);
 346
 347         return (0);
 348 }
 349
 350 /*
 351  * Shutdown processing
 352  */
 353 static int
 354 ng_tee_shutdown(node_p node)
 355 {
 356         const sc_p privdata = NG_NODE_PRIVATE(node);
 357
 358         NG_NODE_SET_PRIVATE(node, NULL);
 359         FREE(privdata, M_NETGRAPH);
 360         NG_NODE_UNREF(node);
 361         return (0);
 362 }
 363
 364 /*
 365  * Hook disconnection
 366  */
 367 static int
 368 ng_tee_disconnect(hook_p hook)
 369 {
 370         sc_p    sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 371         hi_p const hinfo = NG_HOOK_PRIVATE(hook);
 372
 373         KASSERT(hinfo != NULL, ("%s: null info", __func__));
 374         hinfo->hook = NULL;
 375
 376         /* Recalculate internal pathes. */
 377         if (sc->left.dest == hinfo) {
 378                 sc->left.dest = sc->left.dup;
 379                 sc->left.dup = NULL;
 380         } else if (sc->left.dup == hinfo)
 381                 sc->left.dup = NULL;
 382         if (sc->right.dest == hinfo) {
 383                 sc->right.dest = sc->right.dup;
 384                 sc->right.dup = NULL;
 385         } else if (sc->right.dup == hinfo)
 386                 sc->right.dup = NULL;
 387         if (sc->left2right.dest == hinfo)
 388                 sc->left2right.dest = NULL;
 389         if (sc->right2left.dest == hinfo)
 390                 sc->right2left.dest = NULL;
 391
 392         /* Die when last hook disconnected. */
 393         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) &&
 394             NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
 395                 ng_rmnode_self(NG_HOOK_NODE(hook));
 396         return (0);
 397 }