sys/netgraph/tee/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: src/sys/netgraph/ng_tee.c,v 1.7.2.5 2002/07/02 23:44:03 archie Exp $
  40  * $DragonFly: src/sys/netgraph/tee/ng_tee.c,v 1.6 2008/01/05 14:02:40 swildner Exp $
  41  * $Whistle: ng_tee.c,v 1.18 1999/11/01 09:24:52 julian Exp $
  42  */
  43
  44 /*
  45  * This node is like the tee(1) command and is useful for ``snooping.''
  46  * It has 4 hooks: left, right, left2right, and right2left. Data
  47  * entering from the right is passed to the left and duplicated on
  48  * right2left, and data entering from the left is passed to the right
  49  * and duplicated on left2right. Data entering from left2right is
  50  * sent to left, and data from right2left to right.
  51  */
  52
  53 #include <sys/param.h>
  54 #include <sys/systm.h>
  55 #include <sys/errno.h>
  56 #include <sys/kernel.h>
  57 #include <sys/malloc.h>
  58 #include <sys/mbuf.h>
  59 #include <netgraph/ng_message.h>
  60 #include <netgraph/netgraph.h>
  61 #include <netgraph/ng_parse.h>
  62 #include "ng_tee.h"
  63
  64 /* Per hook info */
  65 struct hookinfo {
  66         hook_p                  hook;
  67         struct ng_tee_hookstat  stats;
  68 };
  69
  70 /* Per node info */
  71 struct privdata {
  72         node_p                  node;
  73         struct hookinfo         left;
  74         struct hookinfo         right;
  75         struct hookinfo         left2right;
  76         struct hookinfo         right2left;
  77 };
  78 typedef struct privdata *sc_p;
  79
  80 /* Netgraph methods */
  81 static ng_constructor_t ngt_constructor;
  82 static ng_rcvmsg_t      ngt_rcvmsg;
  83 static ng_shutdown_t    ngt_rmnode;
  84 static ng_newhook_t     ngt_newhook;
  85 static ng_rcvdata_t     ngt_rcvdata;
  86 static ng_disconnect_t  ngt_disconnect;
  87
  88 /* Parse type for struct ng_tee_hookstat */
  89 static const struct ng_parse_struct_field ng_tee_hookstat_type_fields[]
  90         = NG_TEE_HOOKSTAT_INFO;
  91 static const struct ng_parse_type ng_tee_hookstat_type = {
  92         &ng_parse_struct_type,
  93         &ng_tee_hookstat_type_fields
  94 };
  95
  96 /* Parse type for struct ng_tee_stats */
  97 static const struct ng_parse_struct_field ng_tee_stats_type_fields[]
  98         = NG_TEE_STATS_INFO(&ng_tee_hookstat_type);
  99 static const struct ng_parse_type ng_tee_stats_type = {
 100         &ng_parse_struct_type,
 101         &ng_tee_stats_type_fields
 102 };
 103
 104 /* List of commands and how to convert arguments to/from ASCII */
 105 static const struct ng_cmdlist ng_tee_cmds[] = {
 106         {
 107           NGM_TEE_COOKIE,
 108           NGM_TEE_GET_STATS,
 109           "getstats",
 110           NULL,
 111           &ng_tee_stats_type
 112         },
 113         {
 114           NGM_TEE_COOKIE,
 115           NGM_TEE_CLR_STATS,
 116           "clrstats",
 117           NULL,
 118           NULL
 119         },
 120         {
 121           NGM_TEE_COOKIE,
 122           NGM_TEE_GETCLR_STATS,
 123           "getclrstats",
 124           NULL,
 125           &ng_tee_stats_type
 126         },
 127         { 0 }
 128 };
 129
 130 /* Netgraph type descriptor */
 131 static struct ng_type ng_tee_typestruct = {
 132         NG_VERSION,
 133         NG_TEE_NODE_TYPE,
 134         NULL,
 135         ngt_constructor,
 136         ngt_rcvmsg,
 137         ngt_rmnode,
 138         ngt_newhook,
 139         NULL,
 140         NULL,
 141         ngt_rcvdata,
 142         ngt_rcvdata,
 143         ngt_disconnect,
 144         ng_tee_cmds
 145 };
 146 NETGRAPH_INIT(tee, &ng_tee_typestruct);
 147
 148 /*
 149  * Node constructor
 150  */
 151 static int
 152 ngt_constructor(node_p *nodep)
 153 {
 154         sc_p privdata;
 155         int error = 0;
 156
 157         MALLOC(privdata, sc_p, sizeof(*privdata), M_NETGRAPH, M_NOWAIT | M_ZERO);
 158         if (privdata == NULL)
 159                 return (ENOMEM);
 160
 161         if ((error = ng_make_node_common(&ng_tee_typestruct, nodep))) {
 162                 FREE(privdata, M_NETGRAPH);
 163                 return (error);
 164         }
 165         (*nodep)->private = privdata;
 166         privdata->node = *nodep;
 167         return (0);
 168 }
 169
 170 /*
 171  * Add a hook
 172  */
 173 static int
 174 ngt_newhook(node_p node, hook_p hook, const char *name)
 175 {
 176         const sc_p sc = node->private;
 177
 178         if (strcmp(name, NG_TEE_HOOK_RIGHT) == 0) {
 179                 sc->right.hook = hook;
 180                 bzero(&sc->right.stats, sizeof(sc->right.stats));
 181                 hook->private = &sc->right;
 182         } else if (strcmp(name, NG_TEE_HOOK_LEFT) == 0) {
 183                 sc->left.hook = hook;
 184                 bzero(&sc->left.stats, sizeof(sc->left.stats));
 185                 hook->private = &sc->left;
 186         } else if (strcmp(name, NG_TEE_HOOK_RIGHT2LEFT) == 0) {
 187                 sc->right2left.hook = hook;
 188                 bzero(&sc->right2left.stats, sizeof(sc->right2left.stats));
 189                 hook->private = &sc->right2left;
 190         } else if (strcmp(name, NG_TEE_HOOK_LEFT2RIGHT) == 0) {
 191                 sc->left2right.hook = hook;
 192                 bzero(&sc->left2right.stats, sizeof(sc->left2right.stats));
 193                 hook->private = &sc->left2right;
 194         } else
 195                 return (EINVAL);
 196         return (0);
 197 }
 198
 199 /*
 200  * Receive a control message
 201  */
 202 static int
 203 ngt_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
 204            struct ng_mesg **rptr)
 205 {
 206         const sc_p sc = node->private;
 207         struct ng_mesg *resp = NULL;
 208         int error = 0;
 209
 210         switch (msg->header.typecookie) {
 211         case NGM_TEE_COOKIE:
 212                 switch (msg->header.cmd) {
 213                 case NGM_TEE_GET_STATS:
 214                 case NGM_TEE_CLR_STATS:
 215                 case NGM_TEE_GETCLR_STATS:
 216                     {
 217                         struct ng_tee_stats *stats;
 218
 219                         if (msg->header.cmd != NGM_TEE_CLR_STATS) {
 220                                 NG_MKRESPONSE(resp, msg,
 221                                     sizeof(*stats), M_NOWAIT);
 222                                 if (resp == NULL) {
 223                                         error = ENOMEM;
 224                                         goto done;
 225                                 }
 226                                 stats = (struct ng_tee_stats *)resp->data;
 227                                 bcopy(&sc->right.stats, &stats->right,
 228                                     sizeof(stats->right));
 229                                 bcopy(&sc->left.stats, &stats->left,
 230                                     sizeof(stats->left));
 231                                 bcopy(&sc->right2left.stats, &stats->right2left,
 232                                     sizeof(stats->right2left));
 233                                 bcopy(&sc->left2right.stats, &stats->left2right,
 234                                     sizeof(stats->left2right));
 235                         }
 236                         if (msg->header.cmd != NGM_TEE_GET_STATS) {
 237                                 bzero(&sc->right.stats,
 238                                     sizeof(sc->right.stats));
 239                                 bzero(&sc->left.stats,
 240                                     sizeof(sc->left.stats));
 241                                 bzero(&sc->right2left.stats,
 242                                     sizeof(sc->right2left.stats));
 243                                 bzero(&sc->left2right.stats,
 244                                     sizeof(sc->left2right.stats));
 245                         }
 246                         break;
 247                     }
 248                 default:
 249                         error = EINVAL;
 250                         break;
 251                 }
 252                 break;
 253         default:
 254                 error = EINVAL;
 255                 break;
 256         }
 257         if (rptr)
 258                 *rptr = resp;
 259         else if (resp)
 260                 FREE(resp, M_NETGRAPH);
 261
 262 done:
 263         FREE(msg, M_NETGRAPH);
 264         return (error);
 265 }
 266
 267 /*
 268  * Receive data on a hook
 269  *
 270  * If data comes in the right link send a copy out right2left, and then
 271  * send the original onwards out through the left link.
 272  * Do the opposite for data coming in from the left link.
 273  * Data coming in right2left or left2right is forwarded
 274  * on through the appropriate destination hook as if it had come
 275  * from the other side.
 276  */
 277 static int
 278 ngt_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
 279 {
 280         const sc_p sc = hook->node->private;
 281         struct hookinfo *const hinfo = (struct hookinfo *) hook->private;
 282         struct hookinfo *dest;
 283         struct hookinfo *dup;
 284         int error = 0;
 285
 286         /* Which hook? */
 287         if (hinfo == &sc->left) {
 288                 dup = &sc->left2right;
 289                 dest = &sc->right;
 290         } else if (hinfo == &sc->right) {
 291                 dup = &sc->right2left;
 292                 dest = &sc->left;
 293         } else if (hinfo == &sc->right2left) {
 294                 dup = NULL;
 295                 dest = &sc->right;
 296         } else if (hinfo == &sc->left2right) {
 297                 dup = NULL;
 298                 dest = &sc->left;
 299         } else
 300                 panic("%s: no hook!", __func__);
 301
 302         /* Update stats on incoming hook */
 303         hinfo->stats.inOctets += m->m_pkthdr.len;
 304         hinfo->stats.inFrames++;
 305
 306         /* Duplicate packet and meta info if requried */
 307         if (dup != NULL) {
 308                 struct mbuf *m2;
 309                 meta_p meta2;
 310
 311                 /* Copy packet */
 312                 m2 = m_dup(m, M_NOWAIT);
 313                 if (m2 == NULL) {
 314                         NG_FREE_DATA(m, meta);
 315                         return (ENOBUFS);
 316                 }
 317
 318                 /* Copy meta info */
 319                 if (meta != NULL) {
 320                         MALLOC(meta2, meta_p,
 321                             meta->used_len, M_NETGRAPH, M_NOWAIT);
 322                         if (meta2 == NULL) {
 323                                 m_freem(m2);
 324                                 NG_FREE_DATA(m, meta);
 325                                 return (ENOMEM);
 326                         }
 327                         bcopy(meta, meta2, meta->used_len);
 328                         meta2->allocated_len = meta->used_len;
 329                 } else
 330                         meta2 = NULL;
 331
 332                 /* Deliver duplicate */
 333                 dup->stats.outOctets += m->m_pkthdr.len;
 334                 dup->stats.outFrames++;
 335                 NG_SEND_DATA(error, dup->hook, m2, meta2);
 336         }
 337
 338         /* Deliver frame out destination hook */
 339         dest->stats.outOctets += m->m_pkthdr.len;
 340         dest->stats.outFrames++;
 341         NG_SEND_DATA(error, dest->hook, m, meta);
 342         return (error);
 343 }
 344
 345 /*
 346  * Shutdown processing
 347  *
 348  * This is tricky. If we have both a left and right hook, then we
 349  * probably want to extricate ourselves and leave the two peers
 350  * still linked to each other. Otherwise we should just shut down as
 351  * a normal node would.
 352  *
 353  * To keep the scope of info correct the routine to "extract" a node
 354  * from two links is in ng_base.c.
 355  */
 356 static int
 357 ngt_rmnode(node_p node)
 358 {
 359         const sc_p privdata = node->private;
 360
 361         node->flags |= NG_INVALID;
 362         if (privdata->left.hook && privdata->right.hook)
 363                 ng_bypass(privdata->left.hook, privdata->right.hook);
 364         ng_cutlinks(node);
 365         ng_unname(node);
 366         node->private = NULL;
 367         ng_unref(privdata->node);
 368         FREE(privdata, M_NETGRAPH);
 369         return (0);
 370 }
 371
 372 /*
 373  * Hook disconnection
 374  */
 375 static int
 376 ngt_disconnect(hook_p hook)
 377 {
 378         struct hookinfo *const hinfo = (struct hookinfo *) hook->private;
 379
 380         KASSERT(hinfo != NULL, ("%s: null info", __func__));
 381         hinfo->hook = NULL;
 382         if (hook->node->numhooks == 0)
 383                 ng_rmnode(hook->node);
 384         return (0);
 385 }
 386