1 2 /* 3 * ng_sample.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_sample.c,v 1.7.2.3 2002/07/02 23:44:03 archie Exp $ 40 * $DragonFly: src/sys/netgraph/ng_sample.c,v 1.3 2006/01/14 11:10:47 swildner Exp $ 41 * $Whistle: ng_sample.c,v 1.13 1999/11/01 09:24:52 julian Exp $ 42 */ 43 44 #include <sys/param.h> 45 #include <sys/systm.h> 46 #include <sys/kernel.h> 47 #include <sys/mbuf.h> 48 #include <sys/malloc.h> 49 #include <sys/ctype.h> 50 #include <sys/errno.h> 51 #include <sys/syslog.h> 52 53 #include <netgraph/ng_message.h> 54 #include <netgraph/ng_parse.h> 55 #include <netgraph/ng_sample.h> 56 #include <netgraph/netgraph.h> 57 58 /* 59 * This section contains the netgraph method declarations for the 60 * sample node. These methods define the netgraph 'type'. 61 */ 62 63 static ng_constructor_t ng_xxx_constructor; 64 static ng_rcvmsg_t ng_xxx_rcvmsg; 65 static ng_shutdown_t ng_xxx_rmnode; 66 static ng_newhook_t ng_xxx_newhook; 67 static ng_connect_t ng_xxx_connect; 68 static ng_rcvdata_t ng_xxx_rcvdata; /* note these are both ng_rcvdata_t */ 69 static ng_rcvdata_t ng_xxx_rcvdataq; /* note these are both ng_rcvdata_t */ 70 static ng_disconnect_t ng_xxx_disconnect; 71 72 /* Parse type for struct ngxxxstat */ 73 static const struct ng_parse_struct_field ng_xxx_stat_type_fields[] 74 = NG_XXX_STATS_TYPE_INFO; 75 static const struct ng_parse_type ng_xxx_stat_type = { 76 &ng_parse_struct_type, 77 &ng_xxx_stat_type_fields 78 }; 79 80 /* List of commands and how to convert arguments to/from ASCII */ 81 static const struct ng_cmdlist ng_xxx_cmdlist[] = { 82 { 83 NGM_XXX_COOKIE, 84 NGM_XXX_GET_STATUS, 85 "getstatus", 86 NULL, 87 &ng_xxx_stat_type, 88 }, 89 { 90 NGM_XXX_COOKIE, 91 NGM_XXX_SET_FLAG, 92 "setflag", 93 &ng_parse_int32_type, 94 NULL 95 }, 96 { 0 } 97 }; 98 99 /* Netgraph node type descriptor */ 100 static struct ng_type typestruct = { 101 NG_VERSION, 102 NG_XXX_NODE_TYPE, 103 NULL, 104 ng_xxx_constructor, 105 ng_xxx_rcvmsg, 106 ng_xxx_rmnode, 107 ng_xxx_newhook, 108 NULL, 109 ng_xxx_connect, 110 ng_xxx_rcvdata, 111 ng_xxx_rcvdataq, 112 ng_xxx_disconnect, 113 ng_xxx_cmdlist 114 }; 115 NETGRAPH_INIT(xxx, &typestruct); 116 117 /* Information we store for each hook on each node */ 118 struct XXX_hookinfo { 119 int dlci; /* The DLCI it represents, -1 == downstream */ 120 int channel; /* The channel representing this DLCI */ 121 hook_p hook; 122 }; 123 124 /* Information we store for each node */ 125 struct XXX { 126 struct XXX_hookinfo channel[XXX_NUM_DLCIS]; 127 struct XXX_hookinfo downstream_hook; 128 node_p node; /* back pointer to node */ 129 hook_p debughook; 130 u_int packets_in; /* packets in from downstream */ 131 u_int packets_out; /* packets out towards downstream */ 132 u_int32_t flags; 133 }; 134 typedef struct XXX *xxx_p; 135 136 /* 137 * Allocate the private data structure and the generic node 138 * and link them together. 139 * 140 * ng_make_node_common() returns with a generic node struct 141 * with a single reference for us.. we transfer it to the 142 * private structure.. when we free the private struct we must 143 * unref the node so it gets freed too. 144 * 145 * If this were a device node than this work would be done in the attach() 146 * routine and the constructor would return EINVAL as you should not be able 147 * to creatednodes that depend on hardware (unless you can add the hardware :) 148 */ 149 static int 150 ng_xxx_constructor(node_p *nodep) 151 { 152 xxx_p privdata; 153 int i, error; 154 155 /* Initialize private descriptor */ 156 MALLOC(privdata, xxx_p, sizeof(*privdata), M_NETGRAPH, M_NOWAIT); 157 if (privdata == NULL) 158 return (ENOMEM); 159 bzero(privdata, sizeof(struct XXX)); 160 for (i = 0; i < XXX_NUM_DLCIS; i++) { 161 privdata->channel[i].dlci = -2; 162 privdata->channel[i].channel = i; 163 } 164 165 /* Call the 'generic' (ie, superclass) node constructor */ 166 if ((error = ng_make_node_common(&typestruct, nodep))) { 167 FREE(privdata, M_NETGRAPH); 168 return (error); 169 } 170 171 /* Link structs together; this counts as our one reference to *nodep */ 172 (*nodep)->private = privdata; 173 privdata->node = *nodep; 174 return (0); 175 } 176 177 /* 178 * Give our ok for a hook to be added... 179 * If we are not running this might kick a device into life. 180 * Possibly decode information out of the hook name. 181 * Add the hook's private info to the hook structure. 182 * (if we had some). In this example, we assume that there is a 183 * an array of structs, called 'channel' in the private info, 184 * one for each active channel. The private 185 * pointer of each hook points to the appropriate XXX_hookinfo struct 186 * so that the source of an input packet is easily identified. 187 * (a dlci is a frame relay channel) 188 */ 189 static int 190 ng_xxx_newhook(node_p node, hook_p hook, const char *name) 191 { 192 const xxx_p xxxp = node->private; 193 const char *cp; 194 int dlci = 0; 195 int chan; 196 197 #if 0 198 /* Possibly start up the device if it's not already going */ 199 if ((xxxp->flags & SCF_RUNNING) == 0) { 200 ng_xxx_start_hardware(xxxp); 201 } 202 #endif 203 204 /* Example of how one might use hooks with embedded numbers: All 205 * hooks start with 'dlci' and have a decimal trailing channel 206 * number up to 4 digits Use the leadin defined int he associated .h 207 * file. */ 208 if (strncmp(name, 209 NG_XXX_HOOK_DLCI_LEADIN, strlen(NG_XXX_HOOK_DLCI_LEADIN)) == 0) { 210 char *eptr; 211 212 cp = name + sizeof(NG_XXX_HOOK_DLCI_LEADIN); 213 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) 214 return (EINVAL); 215 dlci = (int)strtoul(cp, &eptr, 10); 216 if (*eptr != '\0' || dlci < 0 || dlci > 1023) 217 return (EINVAL); 218 219 /* We have a dlci, now either find it, or allocate it */ 220 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 221 if (xxxp->channel[chan].dlci == dlci) 222 break; 223 if (chan == XXX_NUM_DLCIS) { 224 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 225 if (xxxp->channel[chan].dlci != -2) 226 continue; 227 if (chan == XXX_NUM_DLCIS) 228 return (ENOBUFS); 229 } 230 if (xxxp->channel[chan].hook != NULL) 231 return (EADDRINUSE); 232 hook->private = xxxp->channel + chan; 233 xxxp->channel[chan].hook = hook; 234 return (0); 235 } else if (strcmp(name, NG_XXX_HOOK_DOWNSTREAM) == 0) { 236 /* Example of simple predefined hooks. */ 237 /* do something specific to the downstream connection */ 238 xxxp->downstream_hook.hook = hook; 239 hook->private = &xxxp->downstream_hook; 240 } else if (strcmp(name, NG_XXX_HOOK_DEBUG) == 0) { 241 /* do something specific to a debug connection */ 242 xxxp->debughook = hook; 243 hook->private = NULL; 244 } else 245 return (EINVAL); /* not a hook we know about */ 246 return(0); 247 } 248 249 /* 250 * Get a netgraph control message. 251 * Check it is one we understand. If needed, send a response. 252 * We could save the address for an async action later, but don't here. 253 * Always free the message. 254 * The response should be in a malloc'd region that the caller can 'free'. 255 * A response is not required. 256 * Theoretically you could respond defferently to old message types if 257 * the cookie in the header didn't match what we consider to be current 258 * (so that old userland programs could continue to work). 259 */ 260 static int 261 ng_xxx_rcvmsg(node_p node, 262 struct ng_mesg *msg, const char *retaddr, struct ng_mesg **rptr) 263 { 264 const xxx_p xxxp = node->private; 265 struct ng_mesg *resp = NULL; 266 int error = 0; 267 268 /* Deal with message according to cookie and command */ 269 switch (msg->header.typecookie) { 270 case NGM_XXX_COOKIE: 271 switch (msg->header.cmd) { 272 case NGM_XXX_GET_STATUS: 273 { 274 struct ngxxxstat *stats; 275 276 NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT); 277 if (!resp) { 278 error = ENOMEM; 279 break; 280 } 281 stats = (struct ngxxxstat *) resp->data; 282 stats->packets_in = xxxp->packets_in; 283 stats->packets_out = xxxp->packets_out; 284 break; 285 } 286 case NGM_XXX_SET_FLAG: 287 if (msg->header.arglen != sizeof(u_int32_t)) { 288 error = EINVAL; 289 break; 290 } 291 xxxp->flags = *((u_int32_t *) msg->data); 292 break; 293 default: 294 error = EINVAL; /* unknown command */ 295 break; 296 } 297 break; 298 default: 299 error = EINVAL; /* unknown cookie type */ 300 break; 301 } 302 303 /* Take care of synchronous response, if any */ 304 if (rptr) 305 *rptr = resp; 306 else if (resp) 307 FREE(resp, M_NETGRAPH); 308 309 /* Free the message and return */ 310 FREE(msg, M_NETGRAPH); 311 return(error); 312 } 313 314 /* 315 * Receive data, and do something with it. 316 * Possibly send it out on another link after processing. 317 * Possibly do something different if it comes from different 318 * hooks. the caller will never free m or meta, so 319 * if we use up this data or abort we must free BOTH of these. 320 * 321 * If we want, we may decide to force this data to be queued and reprocessed 322 * at the netgraph NETISR time. (at which time it will be entered using ng_xxx_rcvdataq(). 323 */ 324 static int 325 ng_xxx_rcvdata(hook_p hook, struct mbuf *m, meta_p meta) 326 { 327 int dlci = -2; 328 329 if (hook->private) { 330 /* 331 * If it's dlci 1023, requeue it so that it's handled 332 * at a lower priority. This is how a node decides to 333 * defer a data message. 334 */ 335 dlci = ((struct XXX_hookinfo *) hook->private)->dlci; 336 if (dlci == 1023) { 337 return(ng_queue_data(hook->peer, m, meta)); 338 } 339 } 340 return(ng_xxx_rcvdataq(hook, m, meta)); 341 } 342 343 /* 344 * Always accept the data. This version of rcvdata is called from the dequeueing routine. 345 */ 346 static int 347 ng_xxx_rcvdataq(hook_p hook, struct mbuf *m, meta_p meta) 348 { 349 const xxx_p xxxp = hook->node->private; 350 int chan = -2; 351 int dlci = -2; 352 int error; 353 354 if (hook->private) { 355 dlci = ((struct XXX_hookinfo *) hook->private)->dlci; 356 chan = ((struct XXX_hookinfo *) hook->private)->channel; 357 if (dlci != -1) { 358 /* If received on a DLCI hook process for this 359 * channel and pass it to the downstream module. 360 * Normally one would add a multiplexing header at 361 * the front here */ 362 /* M_PREPEND(....) ; */ 363 /* mtod(m, xxxxxx)->dlci = dlci; */ 364 error = ng_send_data(xxxp->downstream_hook.hook, 365 m, meta); 366 xxxp->packets_out++; 367 } else { 368 /* data came from the multiplexed link */ 369 dlci = 1; /* get dlci from header */ 370 /* madjust(....) *//* chop off header */ 371 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 372 if (xxxp->channel[chan].dlci == dlci) 373 break; 374 if (chan == XXX_NUM_DLCIS) { 375 NG_FREE_DATA(m, meta); 376 return (ENETUNREACH); 377 } 378 /* If we were called at splnet, use the following: 379 * NG_SEND_DATA(error, otherhook, m, meta); if this 380 * node is running at some SPL other than SPLNET 381 * then you should use instead: error = 382 * ng_queueit(otherhook, m, meta); m = NULL: meta = 383 * NULL; this queues the data using the standard 384 * NETISR system and schedules the data to be picked 385 * up again once the system has moved to SPLNET and 386 * the processing of the data can continue. after 387 * these are run 'm' and 'meta' should be considered 388 * as invalid and NG_SEND_DATA actually zaps them. */ 389 NG_SEND_DATA(error, xxxp->channel[chan].hook, m, meta); 390 xxxp->packets_in++; 391 } 392 } else { 393 /* It's the debug hook, throw it away.. */ 394 if (hook == xxxp->downstream_hook.hook) 395 NG_FREE_DATA(m, meta); 396 } 397 return 0; 398 } 399 400 #if 0 401 /* 402 * If this were a device node, the data may have been received in response 403 * to some interrupt. 404 * in which case it would probably look as follows: 405 */ 406 void 407 devintr(void) 408 { 409 meta_p meta = NULL; /* whatever metadata we might imagine goes 410 * here */ 411 412 /* get packet from device and send on */ 413 m = MGET(blah blah) 414 error = ng_queueit(upstream, m, meta); /* see note above in 415 * xxx_rcvdata() */ 416 } 417 418 #endif /* 0 */ 419 420 /* 421 * Do local shutdown processing.. 422 * If we are a persistant device, we might refuse to go away, and 423 * we'd only remove our links and reset ourself. 424 */ 425 static int 426 ng_xxx_rmnode(node_p node) 427 { 428 const xxx_p privdata = node->private; 429 430 node->flags |= NG_INVALID; 431 ng_cutlinks(node); 432 #ifndef PERSISTANT_NODE 433 ng_unname(node); 434 node->private = NULL; 435 ng_unref(privdata->node); 436 FREE(privdata, M_NETGRAPH); 437 #else 438 privdata->packets_in = 0; /* reset stats */ 439 privdata->packets_out = 0; 440 node->flags &= ~NG_INVALID; /* reset invalid flag */ 441 #endif /* PERSISTANT_NODE */ 442 return (0); 443 } 444 445 /* 446 * This is called once we've already connected a new hook to the other node. 447 * It gives us a chance to balk at the last minute. 448 */ 449 static int 450 ng_xxx_connect(hook_p hook) 451 { 452 /* be really amiable and just say "YUP that's OK by me! " */ 453 return (0); 454 } 455 456 /* 457 * Dook disconnection 458 * 459 * For this type, removal of the last link destroys the node 460 */ 461 static int 462 ng_xxx_disconnect(hook_p hook) 463 { 464 if (hook->private) 465 ((struct XXX_hookinfo *) (hook->private))->hook = NULL; 466 if (hook->node->numhooks == 0) 467 ng_rmnode(hook->node); 468 return (0); 469 } 470 471