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  * $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 "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_rmnode;
  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_VERSION,
 132         NG_TEE_NODE_TYPE,
 133         NULL,
 134         ngt_constructor,
 135         ngt_rcvmsg,
 136         ngt_rmnode,
 137         ngt_newhook,
 138         NULL,
 139         NULL,
 140         ngt_rcvdata,
 141         ngt_rcvdata,
 142         ngt_disconnect,
 143         ng_tee_cmds
 144 };
 145 NETGRAPH_INIT(tee, &ng_tee_typestruct);
 146
 147 /*
 148  * Node constructor
 149  */
 150 static int
 151 ngt_constructor(node_p *nodep)
 152 {
 153         sc_p privdata;
 154         int error = 0;
 155
 156         privdata = kmalloc(sizeof(*privdata), M_NETGRAPH, M_NOWAIT | M_ZERO);
 157         if (privdata == NULL)
 158                 return (ENOMEM);
 159
 160         if ((error = ng_make_node_common(&ng_tee_typestruct, nodep))) {
 161                 kfree(privdata, M_NETGRAPH);
 162                 return (error);
 163         }
 164         (*nodep)->private = privdata;
 165         privdata->node = *nodep;
 166         return (0);
 167 }
 168
 169 /*
 170  * Add a hook
 171  */
 172 static int
 173 ngt_newhook(node_p node, hook_p hook, const char *name)
 174 {
 175         const sc_p sc = node->private;
 176
 177         if (strcmp(name, NG_TEE_HOOK_RIGHT) == 0) {
 178                 sc->right.hook = hook;
 179                 bzero(&sc->right.stats, sizeof(sc->right.stats));
 180                 hook->private = &sc->right;
 181         } else if (strcmp(name, NG_TEE_HOOK_LEFT) == 0) {
 182                 sc->left.hook = hook;
 183                 bzero(&sc->left.stats, sizeof(sc->left.stats));
 184                 hook->private = &sc->left;
 185         } else if (strcmp(name, NG_TEE_HOOK_RIGHT2LEFT) == 0) {
 186                 sc->right2left.hook = hook;
 187                 bzero(&sc->right2left.stats, sizeof(sc->right2left.stats));
 188                 hook->private = &sc->right2left;
 189         } else if (strcmp(name, NG_TEE_HOOK_LEFT2RIGHT) == 0) {
 190                 sc->left2right.hook = hook;
 191                 bzero(&sc->left2right.stats, sizeof(sc->left2right.stats));
 192                 hook->private = &sc->left2right;
 193         } else
 194                 return (EINVAL);
 195         return (0);
 196 }
 197
 198 /*
 199  * Receive a control message
 200  */
 201 static int
 202 ngt_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
 203            struct ng_mesg **rptr)
 204 {
 205         const sc_p sc = node->private;
 206         struct ng_mesg *resp = NULL;
 207         int error = 0;
 208
 209         switch (msg->header.typecookie) {
 210         case NGM_TEE_COOKIE:
 211                 switch (msg->header.cmd) {
 212                 case NGM_TEE_GET_STATS:
 213                 case NGM_TEE_CLR_STATS:
 214                 case NGM_TEE_GETCLR_STATS:
 215                     {
 216                         struct ng_tee_stats *stats;
 217
 218                         if (msg->header.cmd != NGM_TEE_CLR_STATS) {
 219                                 NG_MKRESPONSE(resp, msg,
 220                                     sizeof(*stats), M_NOWAIT);
 221                                 if (resp == NULL) {
 222                                         error = ENOMEM;
 223                                         goto done;
 224                                 }
 225                                 stats = (struct ng_tee_stats *)resp->data;
 226                                 bcopy(&sc->right.stats, &stats->right,
 227                                     sizeof(stats->right));
 228                                 bcopy(&sc->left.stats, &stats->left,
 229                                     sizeof(stats->left));
 230                                 bcopy(&sc->right2left.stats, &stats->right2left,
 231                                     sizeof(stats->right2left));
 232                                 bcopy(&sc->left2right.stats, &stats->left2right,
 233                                     sizeof(stats->left2right));
 234                         }
 235                         if (msg->header.cmd != NGM_TEE_GET_STATS) {
 236                                 bzero(&sc->right.stats,
 237                                     sizeof(sc->right.stats));
 238                                 bzero(&sc->left.stats,
 239                                     sizeof(sc->left.stats));
 240                                 bzero(&sc->right2left.stats,
 241                                     sizeof(sc->right2left.stats));
 242                                 bzero(&sc->left2right.stats,
 243                                     sizeof(sc->left2right.stats));
 244                         }
 245                         break;
 246                     }
 247                 default:
 248                         error = EINVAL;
 249                         break;
 250                 }
 251                 break;
 252         default:
 253                 error = EINVAL;
 254                 break;
 255         }
 256         if (rptr)
 257                 *rptr = resp;
 258         else if (resp)
 259                 kfree(resp, M_NETGRAPH);
 260
 261 done:
 262         kfree(msg, M_NETGRAPH);
 263         return (error);
 264 }
 265
 266 /*
 267  * Receive data on a hook
 268  *
 269  * If data comes in the right link send a copy out right2left, and then
 270  * send the original onwards out through the left link.
 271  * Do the opposite for data coming in from the left link.
 272  * Data coming in right2left or left2right is forwarded
 273  * on through the appropriate destination hook as if it had come
 274  * from the other side.
 275  */
 276 static int
 277 ngt_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
 278 {
 279         const sc_p sc = hook->node->private;
 280         struct hookinfo *const hinfo = (struct hookinfo *) hook->private;
 281         struct hookinfo *dest;
 282         struct hookinfo *dup;
 283         int error = 0;
 284
 285         /* Which hook? */
 286         if (hinfo == &sc->left) {
 287                 dup = &sc->left2right;
 288                 dest = &sc->right;
 289         } else if (hinfo == &sc->right) {
 290                 dup = &sc->right2left;
 291                 dest = &sc->left;
 292         } else if (hinfo == &sc->right2left) {
 293                 dup = NULL;
 294                 dest = &sc->right;
 295         } else if (hinfo == &sc->left2right) {
 296                 dup = NULL;
 297                 dest = &sc->left;
 298         } else
 299                 panic("%s: no hook!", __func__);
 300
 301         /* Update stats on incoming hook */
 302         hinfo->stats.inOctets += m->m_pkthdr.len;
 303         hinfo->stats.inFrames++;
 304
 305         /* Duplicate packet and meta info if requried */
 306         if (dup != NULL) {
 307                 struct mbuf *m2;
 308                 meta_p meta2;
 309
 310                 /* Copy packet */
 311                 m2 = m_dup(m, M_NOWAIT);
 312                 if (m2 == NULL) {
 313                         NG_FREE_DATA(m, meta);
 314                         return (ENOBUFS);
 315                 }
 316
 317                 /* Copy meta info */
 318                 if (meta != NULL) {
 319                         meta2 = kmalloc(meta->used_len, M_NETGRAPH, M_NOWAIT);
 320                         if (meta2 == NULL) {
 321                                 m_freem(m2);
 322                                 NG_FREE_DATA(m, meta);
 323                                 return (ENOMEM);
 324                         }
 325                         bcopy(meta, meta2, meta->used_len);
 326                         meta2->allocated_len = meta->used_len;
 327                 } else
 328                         meta2 = NULL;
 329
 330                 /* Deliver duplicate */
 331                 dup->stats.outOctets += m->m_pkthdr.len;
 332                 dup->stats.outFrames++;
 333                 NG_SEND_DATA(error, dup->hook, m2, meta2);
 334         }
 335
 336         /* Deliver frame out destination hook */
 337         dest->stats.outOctets += m->m_pkthdr.len;
 338         dest->stats.outFrames++;
 339         NG_SEND_DATA(error, dest->hook, m, meta);
 340         return (error);
 341 }
 342
 343 /*
 344  * Shutdown processing
 345  *
 346  * This is tricky. If we have both a left and right hook, then we
 347  * probably want to extricate ourselves and leave the two peers
 348  * still linked to each other. Otherwise we should just shut down as
 349  * a normal node would.
 350  *
 351  * To keep the scope of info correct the routine to "extract" a node
 352  * from two links is in ng_base.c.
 353  */
 354 static int
 355 ngt_rmnode(node_p node)
 356 {
 357         const sc_p privdata = node->private;
 358
 359         node->flags |= NG_INVALID;
 360         if (privdata->left.hook && privdata->right.hook)
 361                 ng_bypass(privdata->left.hook, privdata->right.hook);
 362         ng_cutlinks(node);
 363         ng_unname(node);
 364         node->private = NULL;
 365         ng_unref(privdata->node);
 366         kfree(privdata, M_NETGRAPH);
 367         return (0);
 368 }
 369
 370 /*
 371  * Hook disconnection
 372  */
 373 static int
 374 ngt_disconnect(hook_p hook)
 375 {
 376         struct hookinfo *const hinfo = (struct hookinfo *) hook->private;
 377
 378         KASSERT(hinfo != NULL, ("%s: null info", __func__));
 379         hinfo->hook = NULL;
 380         if (hook->node->numhooks == 0)
 381                 ng_rmnode(hook->node);
 382         return (0);
 383 }
 384