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  * $DragonFly: src/sys/netgraph7/ng_tee.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
  43  * $Whistle: ng_tee.c,v 1.18 1999/11/01 09:24:52 julian Exp $
  44  */
  45
  46 /*
  47  * This node is like the tee(1) command and is useful for ``snooping.''
  48  * It has 4 hooks: left, right, left2right, and right2left. Data
  49  * entering from the right is passed to the left and duplicated on
  50  * right2left, and data entering from the left is passed to the right
  51  * and duplicated on left2right. Data entering from left2right is
  52  * sent to left, and data from right2left to right.
  53  */
  54
  55 #include <sys/param.h>
  56 #include <sys/systm.h>
  57 #include <sys/errno.h>
  58 #include <sys/kernel.h>
  59 #include <sys/malloc.h>
  60 #include <sys/mbuf.h>
  61 #include "ng_message.h"
  62 #include "netgraph.h"
  63 #include "ng_parse.h"
  64 #include "ng_tee.h"
  65
  66 /* Per hook info */
  67 struct hookinfo {
  68         hook_p                  hook;
  69         struct hookinfo         *dest, *dup;
  70         struct ng_tee_hookstat  stats;
  71 };
  72 typedef struct hookinfo *hi_p;
  73
  74 /* Per node info */
  75 struct privdata {
  76         struct hookinfo         left;
  77         struct hookinfo         right;
  78         struct hookinfo         left2right;
  79         struct hookinfo         right2left;
  80 };
  81 typedef struct privdata *sc_p;
  82
  83 /* Netgraph methods */
  84 static ng_constructor_t ng_tee_constructor;
  85 static ng_rcvmsg_t      ng_tee_rcvmsg;
  86 static ng_close_t       ng_tee_close;
  87 static ng_shutdown_t    ng_tee_shutdown;
  88 static ng_newhook_t     ng_tee_newhook;
  89 static ng_rcvdata_t     ng_tee_rcvdata;
  90 static ng_disconnect_t  ng_tee_disconnect;
  91
  92 /* Parse type for struct ng_tee_hookstat */
  93 static const struct ng_parse_struct_field ng_tee_hookstat_type_fields[]
  94         = NG_TEE_HOOKSTAT_INFO;
  95 static const struct ng_parse_type ng_tee_hookstat_type = {
  96         &ng_parse_struct_type,
  97         &ng_tee_hookstat_type_fields
  98 };
  99
 100 /* Parse type for struct ng_tee_stats */
 101 static const struct ng_parse_struct_field ng_tee_stats_type_fields[]
 102         = NG_TEE_STATS_INFO(&ng_tee_hookstat_type);
 103 static const struct ng_parse_type ng_tee_stats_type = {
 104         &ng_parse_struct_type,
 105         &ng_tee_stats_type_fields
 106 };
 107
 108 /* List of commands and how to convert arguments to/from ASCII */
 109 static const struct ng_cmdlist ng_tee_cmds[] = {
 110         {
 111           NGM_TEE_COOKIE,
 112           NGM_TEE_GET_STATS,
 113           "getstats",
 114           NULL,
 115           &ng_tee_stats_type
 116         },
 117         {
 118           NGM_TEE_COOKIE,
 119           NGM_TEE_CLR_STATS,
 120           "clrstats",
 121           NULL,
 122           NULL
 123         },
 124         {
 125           NGM_TEE_COOKIE,
 126           NGM_TEE_GETCLR_STATS,
 127           "getclrstats",
 128           NULL,
 129           &ng_tee_stats_type
 130         },
 131         { 0 }
 132 };
 133
 134 /* Netgraph type descriptor */
 135 static struct ng_type ng_tee_typestruct = {
 136         .version =      NG_ABI_VERSION,
 137         .name =         NG_TEE_NODE_TYPE,
 138         .constructor =  ng_tee_constructor,
 139         .rcvmsg =       ng_tee_rcvmsg,
 140         .close =        ng_tee_close,
 141         .shutdown =     ng_tee_shutdown,
 142         .newhook =      ng_tee_newhook,
 143         .rcvdata =      ng_tee_rcvdata,
 144         .disconnect =   ng_tee_disconnect,
 145         .cmdlist =      ng_tee_cmds,
 146 };
 147 NETGRAPH_INIT(tee, &ng_tee_typestruct);
 148
 149 /*
 150  * Node constructor
 151  */
 152 static int
 153 ng_tee_constructor(node_p node)
 154 {
 155         sc_p privdata;
 156
 157         MALLOC(privdata, sc_p, sizeof(*privdata), M_NETGRAPH, M_WAITOK | M_NULLOK | M_ZERO);
 158         if (privdata == NULL)
 159                 return (ENOMEM);
 160
 161         NG_NODE_SET_PRIVATE(node, privdata);
 162         return (0);
 163 }
 164
 165 /*
 166  * Add a hook
 167  */
 168 static int
 169 ng_tee_newhook(node_p node, hook_p hook, const char *name)
 170 {
 171         sc_p    privdata = NG_NODE_PRIVATE(node);
 172         hi_p    hinfo;
 173
 174         /* Precalculate internal pathes. */
 175         if (strcmp(name, NG_TEE_HOOK_RIGHT) == 0) {
 176                 hinfo = &privdata->right;
 177                 if (privdata->left.dest)
 178                         privdata->left.dup = privdata->left.dest;
 179                 privdata->left.dest = hinfo;
 180                 privdata->right2left.dest = hinfo;
 181         } else if (strcmp(name, NG_TEE_HOOK_LEFT) == 0) {
 182                 hinfo = &privdata->left;
 183                 if (privdata->right.dest)
 184                         privdata->right.dup = privdata->right.dest;
 185                 privdata->right.dest = hinfo;
 186                 privdata->left2right.dest = hinfo;
 187         } else if (strcmp(name, NG_TEE_HOOK_RIGHT2LEFT) == 0) {
 188                 hinfo = &privdata->right2left;
 189                 if (privdata->right.dest)
 190                         privdata->right.dup = hinfo;
 191                 else
 192                         privdata->right.dest = hinfo;
 193         } else if (strcmp(name, NG_TEE_HOOK_LEFT2RIGHT) == 0) {
 194                 hinfo = &privdata->left2right;
 195                 if (privdata->left.dest)
 196                         privdata->left.dup = hinfo;
 197                 else
 198                         privdata->left.dest = hinfo;
 199         } else
 200                 return (EINVAL);
 201         hinfo->hook = hook;
 202         bzero(&hinfo->stats, sizeof(hinfo->stats));
 203         NG_HOOK_SET_PRIVATE(hook, hinfo);
 204         return (0);
 205 }
 206
 207 /*
 208  * Receive a control message
 209  */
 210 static int
 211 ng_tee_rcvmsg(node_p node, item_p item, hook_p lasthook)
 212 {
 213         const sc_p sc = NG_NODE_PRIVATE(node);
 214         struct ng_mesg *resp = NULL;
 215         int error = 0;
 216         struct ng_mesg *msg;
 217
 218         NGI_GET_MSG(item, msg);
 219         switch (msg->header.typecookie) {
 220         case NGM_TEE_COOKIE:
 221                 switch (msg->header.cmd) {
 222                 case NGM_TEE_GET_STATS:
 223                 case NGM_TEE_CLR_STATS:
 224                 case NGM_TEE_GETCLR_STATS:
 225                     {
 226                         struct ng_tee_stats *stats;
 227
 228                         if (msg->header.cmd != NGM_TEE_CLR_STATS) {
 229                                 NG_MKRESPONSE(resp, msg,
 230                                     sizeof(*stats), M_WAITOK | M_NULLOK);
 231                                 if (resp == NULL) {
 232                                         error = ENOMEM;
 233                                         goto done;
 234                                 }
 235                                 stats = (struct ng_tee_stats *)resp->data;
 236                                 bcopy(&sc->right.stats, &stats->right,
 237                                     sizeof(stats->right));
 238                                 bcopy(&sc->left.stats, &stats->left,
 239                                     sizeof(stats->left));
 240                                 bcopy(&sc->right2left.stats, &stats->right2left,
 241                                     sizeof(stats->right2left));
 242                                 bcopy(&sc->left2right.stats, &stats->left2right,
 243                                     sizeof(stats->left2right));
 244                         }
 245                         if (msg->header.cmd != NGM_TEE_GET_STATS) {
 246                                 bzero(&sc->right.stats,
 247                                     sizeof(sc->right.stats));
 248                                 bzero(&sc->left.stats,
 249                                     sizeof(sc->left.stats));
 250                                 bzero(&sc->right2left.stats,
 251                                     sizeof(sc->right2left.stats));
 252                                 bzero(&sc->left2right.stats,
 253                                     sizeof(sc->left2right.stats));
 254                         }
 255                         break;
 256                     }
 257                 default:
 258                         error = EINVAL;
 259                         break;
 260                 }
 261                 break;
 262         case NGM_FLOW_COOKIE:
 263                 if (lasthook == sc->left.hook || lasthook == sc->right.hook)  {
 264                         hi_p const hinfo = NG_HOOK_PRIVATE(lasthook);
 265                         if (hinfo && hinfo->dest) {
 266                                 NGI_MSG(item) = msg;
 267                                 NG_FWD_ITEM_HOOK(error, item, hinfo->dest->hook);
 268                                 return (error);
 269                         }
 270                 }
 271                 break;
 272         default:
 273                 error = EINVAL;
 274                 break;
 275         }
 276 done:
 277         NG_RESPOND_MSG(error, node, item, resp);
 278         NG_FREE_MSG(msg);
 279         return (error);
 280 }
 281
 282 /*
 283  * Receive data on a hook
 284  *
 285  * If data comes in the right link send a copy out right2left, and then
 286  * send the original onwards out through the left link.
 287  * Do the opposite for data coming in from the left link.
 288  * Data coming in right2left or left2right is forwarded
 289  * on through the appropriate destination hook as if it had come
 290  * from the other side.
 291  */
 292 static int
 293 ng_tee_rcvdata(hook_p hook, item_p item)
 294 {
 295         const hi_p hinfo = NG_HOOK_PRIVATE(hook);
 296         hi_p    h;
 297         int     error = 0;
 298         struct mbuf *m;
 299
 300         m = NGI_M(item);
 301
 302         /* Update stats on incoming hook */
 303         hinfo->stats.inOctets += m->m_pkthdr.len;
 304         hinfo->stats.inFrames++;
 305
 306         /* Duplicate packet if requried */
 307         if (hinfo->dup) {
 308                 struct mbuf *m2;
 309
 310                 /* Copy packet (failure will not stop the original)*/
 311                 m2 = m_dup(m, MB_DONTWAIT);
 312                 if (m2) {
 313                         /* Deliver duplicate */
 314                         h = hinfo->dup;
 315                         NG_SEND_DATA_ONLY(error, h->hook, m2);
 316                         if (error == 0) {
 317                                 h->stats.outOctets += m->m_pkthdr.len;
 318                                 h->stats.outFrames++;
 319                         }
 320                 }
 321         }
 322         /* Deliver frame out destination hook */
 323         if (hinfo->dest) {
 324                 h = hinfo->dest;
 325                 h->stats.outOctets += m->m_pkthdr.len;
 326                 h->stats.outFrames++;
 327                 NG_FWD_ITEM_HOOK(error, item, h->hook);
 328         } else
 329                 NG_FREE_ITEM(item);
 330         return (error);
 331 }
 332
 333 /*
 334  * We are going to be shut down soon
 335  *
 336  * If we have both a left and right hook, then we probably want to extricate
 337  * ourselves and leave the two peers still linked to each other. Otherwise we
 338  * should just shut down as a normal node would.
 339  */
 340 static int
 341 ng_tee_close(node_p node)
 342 {
 343         const sc_p privdata = NG_NODE_PRIVATE(node);
 344
 345         if (privdata->left.hook && privdata->right.hook)
 346                 ng_bypass(privdata->left.hook, privdata->right.hook);
 347
 348         return (0);
 349 }
 350
 351 /*
 352  * Shutdown processing
 353  */
 354 static int
 355 ng_tee_shutdown(node_p node)
 356 {
 357         const sc_p privdata = NG_NODE_PRIVATE(node);
 358
 359         NG_NODE_SET_PRIVATE(node, NULL);
 360         FREE(privdata, M_NETGRAPH);
 361         NG_NODE_UNREF(node);
 362         return (0);
 363 }
 364
 365 /*
 366  * Hook disconnection
 367  */
 368 static int
 369 ng_tee_disconnect(hook_p hook)
 370 {
 371         sc_p    sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 372         hi_p const hinfo = NG_HOOK_PRIVATE(hook);
 373
 374         KASSERT(hinfo != NULL, ("%s: null info", __func__));
 375         hinfo->hook = NULL;
 376
 377         /* Recalculate internal pathes. */
 378         if (sc->left.dest == hinfo) {
 379                 sc->left.dest = sc->left.dup;
 380                 sc->left.dup = NULL;
 381         } else if (sc->left.dup == hinfo)
 382                 sc->left.dup = NULL;
 383         if (sc->right.dest == hinfo) {
 384                 sc->right.dest = sc->right.dup;
 385                 sc->right.dup = NULL;
 386         } else if (sc->right.dup == hinfo)
 387                 sc->right.dup = NULL;
 388         if (sc->left2right.dest == hinfo)
 389                 sc->left2right.dest = NULL;
 390         if (sc->right2left.dest == hinfo)
 391                 sc->right2left.dest = NULL;
 392
 393         /* Die when last hook disconnected. */
 394         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) &&
 395             NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))
 396                 ng_rmnode_self(NG_HOOK_NODE(hook));
 397         return (0);
 398 }