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@whistle.com> 38 * 39 * $FreeBSD$ 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 right, and data from right2left to left. 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_tee.h> 61 62 /* Per hook info */ 63 struct hookinfo { 64 hook_p hook; 65 struct ng_tee_hookstat stats; 66 }; 67 68 /* Per node info */ 69 struct privdata { 70 node_p node; 71 struct hookinfo left; 72 struct hookinfo right; 73 struct hookinfo left2right; 74 struct hookinfo right2left; 75 }; 76 typedef struct privdata *sc_p; 77 78 /* Netgraph methods */ 79 static ng_constructor_t ngt_constructor; 80 static ng_rcvmsg_t ngt_rcvmsg; 81 static ng_shutdown_t ngt_rmnode; 82 static ng_newhook_t ngt_newhook; 83 static ng_rcvdata_t ngt_rcvdata; 84 static ng_disconnect_t ngt_disconnect; 85 86 /* Netgraph type descriptor */ 87 static struct ng_type typestruct = { 88 NG_VERSION, 89 NG_TEE_NODE_TYPE, 90 NULL, 91 ngt_constructor, 92 ngt_rcvmsg, 93 ngt_rmnode, 94 ngt_newhook, 95 NULL, 96 NULL, 97 ngt_rcvdata, 98 ngt_rcvdata, 99 ngt_disconnect 100 }; 101 NETGRAPH_INIT(tee, &typestruct); 102 103 /* 104 * Node constructor 105 */ 106 static int 107 ngt_constructor(node_p *nodep) 108 { 109 sc_p privdata; 110 int error = 0; 111 112 MALLOC(privdata, sc_p, sizeof(*privdata), M_NETGRAPH, M_WAITOK); 113 if (privdata == NULL) 114 return (ENOMEM); 115 bzero(privdata, sizeof(*privdata)); 116 117 if ((error = ng_make_node_common(&typestruct, nodep))) { 118 FREE(privdata, M_NETGRAPH); 119 return (error); 120 } 121 (*nodep)->private = privdata; 122 privdata->node = *nodep; 123 return (0); 124 } 125 126 /* 127 * Add a hook 128 */ 129 static int 130 ngt_newhook(node_p node, hook_p hook, const char *name) 131 { 132 const sc_p sc = node->private; 133 134 if (strcmp(name, NG_TEE_HOOK_RIGHT) == 0) { 135 sc->right.hook = hook; 136 bzero(&sc->right.stats, sizeof(sc->right.stats)); 137 hook->private = &sc->right; 138 } else if (strcmp(name, NG_TEE_HOOK_LEFT) == 0) { 139 sc->left.hook = hook; 140 bzero(&sc->left.stats, sizeof(sc->left.stats)); 141 hook->private = &sc->left; 142 } else if (strcmp(name, NG_TEE_HOOK_RIGHT2LEFT) == 0) { 143 sc->right2left.hook = hook; 144 bzero(&sc->right2left.stats, sizeof(sc->right2left.stats)); 145 hook->private = &sc->right2left; 146 } else if (strcmp(name, NG_TEE_HOOK_LEFT2RIGHT) == 0) { 147 sc->left2right.hook = hook; 148 bzero(&sc->left2right.stats, sizeof(sc->left2right.stats)); 149 hook->private = &sc->left2right; 150 } else 151 return (EINVAL); 152 return (0); 153 } 154 155 /* 156 * Receive a control message 157 */ 158 static int 159 ngt_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr, 160 struct ng_mesg **rptr) 161 { 162 const sc_p sc = node->private; 163 struct ng_mesg *resp = NULL; 164 int error = 0; 165 166 switch (msg->header.typecookie) { 167 case NGM_TEE_COOKIE: 168 switch (msg->header.cmd) { 169 case NGM_TEE_GET_STATS: 170 { 171 struct ng_tee_stats *stats; 172 173 NG_MKRESPONSE(resp, msg, 174 sizeof(struct ng_tee_stats), M_NOWAIT); 175 if (resp == NULL) { 176 error = ENOMEM; 177 goto done; 178 } 179 stats = (struct ng_tee_stats *) resp->data; 180 bcopy(&sc->right.stats, 181 &stats->right, sizeof(stats->right)); 182 bcopy(&sc->left.stats, 183 &stats->left, sizeof(stats->left)); 184 bcopy(&sc->right2left.stats, 185 &stats->right2left, sizeof(stats->right2left)); 186 bcopy(&sc->left2right.stats, 187 &stats->left2right, sizeof(stats->left2right)); 188 break; 189 } 190 case NGM_TEE_CLR_STATS: 191 bzero(&sc->right.stats, sizeof(sc->right.stats)); 192 bzero(&sc->left.stats, sizeof(sc->left.stats)); 193 bzero(&sc->right2left.stats, 194 sizeof(sc->right2left.stats)); 195 bzero(&sc->left2right.stats, 196 sizeof(sc->left2right.stats)); 197 break; 198 default: 199 error = EINVAL; 200 break; 201 } 202 break; 203 default: 204 error = EINVAL; 205 break; 206 } 207 if (rptr) 208 *rptr = resp; 209 else if (resp) 210 FREE(resp, M_NETGRAPH); 211 212 done: 213 FREE(msg, M_NETGRAPH); 214 return (error); 215 } 216 217 /* 218 * Receive data on a hook 219 * 220 * If data comes in the right link send a copy out right2left, and then 221 * send the original onwards out through the left link. 222 * Do the opposite for data coming in from the left link. 223 * Data coming in right2left or left2right is forwarded 224 * on through the appropriate destination hook as if it had come 225 * from the other side. 226 */ 227 static int 228 ngt_rcvdata(hook_p hook, struct mbuf *m, meta_p meta) 229 { 230 const sc_p sc = hook->node->private; 231 struct hookinfo *const hinfo = (struct hookinfo *) hook->private; 232 struct hookinfo *dest; 233 struct hookinfo *dup; 234 int error = 0; 235 236 /* Which hook? */ 237 if (hinfo == &sc->left) { 238 dup = &sc->left2right; 239 dest = &sc->right; 240 } else if (hinfo == &sc->right) { 241 dup = &sc->right2left; 242 dest = &sc->left; 243 } else if (hinfo == &sc->right2left) { 244 dup = NULL; 245 dest = &sc->left; 246 } else if (hinfo == &sc->left2right) { 247 dup = NULL; 248 dest = &sc->right; 249 } else 250 panic("%s: no hook!", __FUNCTION__); 251 252 /* Update stats on incoming hook */ 253 hinfo->stats.inOctets += m->m_pkthdr.len; 254 hinfo->stats.inFrames++; 255 256 /* Duplicate packet and meta info if requried */ 257 if (dup != NULL) { 258 struct mbuf *m2; 259 meta_p meta2; 260 261 /* Copy packet */ 262 m2 = m_copypacket(m, M_NOWAIT); 263 if (m2 == NULL) { 264 NG_FREE_DATA(m, meta); 265 return (ENOBUFS); 266 } 267 268 /* Copy meta info */ 269 MALLOC(meta2, meta_p, 270 meta->used_len, M_NETGRAPH, M_NOWAIT); 271 if (meta2 == NULL) { 272 m_freem(m2); 273 NG_FREE_DATA(m, meta); 274 return (ENOMEM); 275 } 276 meta2->allocated_len = meta->used_len; 277 bcopy(meta, meta2, meta->used_len); 278 279 /* Deliver duplicate */ 280 dup->stats.outOctets += m->m_pkthdr.len; 281 dup->stats.outFrames++; 282 NG_SEND_DATA(error, dup->hook, m2, meta2); 283 } 284 285 /* Deliver frame out destination hook */ 286 dest->stats.outOctets += m->m_pkthdr.len; 287 dest->stats.outFrames++; 288 NG_SEND_DATA(error, dest->hook, m, meta); 289 return (0); 290 } 291 292 /* 293 * Shutdown processing 294 * 295 * This is tricky. If we have both a left and right hook, then we 296 * probably want to extricate ourselves and leave the two peers 297 * still linked to each other. Otherwise we should just shut down as 298 * a normal node would. 299 * 300 * To keep the scope of info correct the routine to "extract" a node 301 * from two links is in ng_base.c. 302 */ 303 static int 304 ngt_rmnode(node_p node) 305 { 306 const sc_p privdata = node->private; 307 308 node->flags |= NG_INVALID; 309 if (privdata->left.hook && privdata->right.hook) 310 ng_bypass(privdata->left.hook, privdata->right.hook); 311 ng_cutlinks(node); 312 ng_unname(node); 313 node->private = NULL; 314 ng_unref(privdata->node); 315 FREE(privdata, M_NETGRAPH); 316 return (0); 317 } 318 319 /* 320 * Hook disconnection 321 */ 322 static int 323 ngt_disconnect(hook_p hook) 324 { 325 struct hookinfo *const hinfo = (struct hookinfo *) hook->private; 326 327 KASSERT(hinfo != NULL, ("%s: null info", __FUNCTION__)); 328 hinfo->hook = NULL; 329 if (hook->node->numhooks == 0) 330 ng_rmnode(hook->node); 331 return (0); 332 } 333 334