1 /* 2 * ng_sample.c 3 */ 4 5 /*- 6 * Copyright (c) 1996-1999 Whistle Communications, Inc. 7 * All rights reserved. 8 * 9 * Subject to the following obligations and disclaimer of warranty, use and 10 * redistribution of this software, in source or object code forms, with or 11 * without modifications are expressly permitted by Whistle Communications; 12 * provided, however, that: 13 * 1. Any and all reproductions of the source or object code must include the 14 * copyright notice above and the following disclaimer of warranties; and 15 * 2. No rights are granted, in any manner or form, to use Whistle 16 * Communications, Inc. trademarks, including the mark "WHISTLE 17 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as 18 * such appears in the above copyright notice or in the software. 19 * 20 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 21 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 22 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 23 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 25 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 26 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 27 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 28 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 29 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 30 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 31 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 32 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 36 * OF SUCH DAMAGE. 37 * 38 * Author: Julian Elischer <julian@freebsd.org> 39 * 40 * $FreeBSD$ 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 /* If you do complicated mallocs you may want to do this */ 59 /* and use it for your mallocs */ 60 #ifdef NG_SEPARATE_MALLOC 61 static MALLOC_DEFINE(M_NETGRAPH_XXX, "netgraph_xxx", "netgraph xxx node"); 62 #else 63 #define M_NETGRAPH_XXX M_NETGRAPH 64 #endif 65 66 /* 67 * This section contains the netgraph method declarations for the 68 * sample node. These methods define the netgraph 'type'. 69 */ 70 71 static ng_constructor_t ng_xxx_constructor; 72 static ng_rcvmsg_t ng_xxx_rcvmsg; 73 static ng_shutdown_t ng_xxx_shutdown; 74 static ng_newhook_t ng_xxx_newhook; 75 static ng_connect_t ng_xxx_connect; 76 static ng_rcvdata_t ng_xxx_rcvdata; 77 static ng_disconnect_t ng_xxx_disconnect; 78 79 /* Parse type for struct ngxxxstat */ 80 static const struct ng_parse_struct_field ng_xxx_stat_type_fields[] 81 = NG_XXX_STATS_TYPE_INFO; 82 static const struct ng_parse_type ng_xxx_stat_type = { 83 &ng_parse_struct_type, 84 &ng_xxx_stat_type_fields 85 }; 86 87 /* List of commands and how to convert arguments to/from ASCII */ 88 static const struct ng_cmdlist ng_xxx_cmdlist[] = { 89 { 90 NGM_XXX_COOKIE, 91 NGM_XXX_GET_STATUS, 92 "getstatus", 93 NULL, 94 &ng_xxx_stat_type, 95 }, 96 { 97 NGM_XXX_COOKIE, 98 NGM_XXX_SET_FLAG, 99 "setflag", 100 &ng_parse_int32_type, 101 NULL 102 }, 103 { 0 } 104 }; 105 106 /* Netgraph node type descriptor */ 107 static struct ng_type typestruct = { 108 .version = NG_ABI_VERSION, 109 .name = NG_XXX_NODE_TYPE, 110 .constructor = ng_xxx_constructor, 111 .rcvmsg = ng_xxx_rcvmsg, 112 .shutdown = ng_xxx_shutdown, 113 .newhook = ng_xxx_newhook, 114 /* .findhook = ng_xxx_findhook, */ 115 .connect = ng_xxx_connect, 116 .rcvdata = ng_xxx_rcvdata, 117 .disconnect = ng_xxx_disconnect, 118 .cmdlist = ng_xxx_cmdlist, 119 }; 120 NETGRAPH_INIT(xxx, &typestruct); 121 122 /* Information we store for each hook on each node */ 123 struct XXX_hookinfo { 124 int dlci; /* The DLCI it represents, -1 == downstream */ 125 int channel; /* The channel representing this DLCI */ 126 hook_p hook; 127 }; 128 129 /* Information we store for each node */ 130 struct XXX { 131 struct XXX_hookinfo channel[XXX_NUM_DLCIS]; 132 struct XXX_hookinfo downstream_hook; 133 node_p node; /* back pointer to node */ 134 hook_p debughook; 135 u_int packets_in; /* packets in from downstream */ 136 u_int packets_out; /* packets out towards downstream */ 137 u_int32_t flags; 138 }; 139 typedef struct XXX *xxx_p; 140 141 /* 142 * Allocate the private data structure. The generic node has already 143 * been created. Link them together. We arrive with a reference to the node 144 * i.e. the reference count is incremented for us already. 145 * 146 * If this were a device node than this work would be done in the attach() 147 * routine and the constructor would return EINVAL as you should not be able 148 * to creatednodes that depend on hardware (unless you can add the hardware :) 149 */ 150 static int 151 ng_xxx_constructor(node_p node) 152 { 153 xxx_p privdata; 154 int i; 155 156 /* Initialize private descriptor */ 157 privdata = malloc(sizeof(*privdata), M_NETGRAPH, M_WAITOK | M_ZERO); 158 for (i = 0; i < XXX_NUM_DLCIS; i++) { 159 privdata->channel[i].dlci = -2; 160 privdata->channel[i].channel = i; 161 } 162 163 /* Link structs together; this counts as our one reference to *nodep */ 164 NG_NODE_SET_PRIVATE(node, privdata); 165 privdata->node = node; 166 return (0); 167 } 168 169 /* 170 * Give our ok for a hook to be added... 171 * If we are not running this might kick a device into life. 172 * Possibly decode information out of the hook name. 173 * Add the hook's private info to the hook structure. 174 * (if we had some). In this example, we assume that there is a 175 * an array of structs, called 'channel' in the private info, 176 * one for each active channel. The private 177 * pointer of each hook points to the appropriate XXX_hookinfo struct 178 * so that the source of an input packet is easily identified. 179 * (a dlci is a frame relay channel) 180 */ 181 static int 182 ng_xxx_newhook(node_p node, hook_p hook, const char *name) 183 { 184 const xxx_p xxxp = NG_NODE_PRIVATE(node); 185 const char *cp; 186 int dlci = 0; 187 int chan; 188 189 #if 0 190 /* Possibly start up the device if it's not already going */ 191 if ((xxxp->flags & SCF_RUNNING) == 0) { 192 ng_xxx_start_hardware(xxxp); 193 } 194 #endif 195 196 /* Example of how one might use hooks with embedded numbers: All 197 * hooks start with 'dlci' and have a decimal trailing channel 198 * number up to 4 digits Use the leadin defined int he associated .h 199 * file. */ 200 if (strncmp(name, 201 NG_XXX_HOOK_DLCI_LEADIN, strlen(NG_XXX_HOOK_DLCI_LEADIN)) == 0) { 202 char *eptr; 203 204 cp = name + strlen(NG_XXX_HOOK_DLCI_LEADIN); 205 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) 206 return (EINVAL); 207 dlci = (int)strtoul(cp, &eptr, 10); 208 if (*eptr != '\0' || dlci < 0 || dlci > 1023) 209 return (EINVAL); 210 211 /* We have a dlci, now either find it, or allocate it */ 212 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 213 if (xxxp->channel[chan].dlci == dlci) 214 break; 215 if (chan == XXX_NUM_DLCIS) { 216 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 217 if (xxxp->channel[chan].dlci == -2) 218 break; 219 if (chan == XXX_NUM_DLCIS) 220 return (ENOBUFS); 221 xxxp->channel[chan].dlci = dlci; 222 } 223 if (xxxp->channel[chan].hook != NULL) 224 return (EADDRINUSE); 225 NG_HOOK_SET_PRIVATE(hook, xxxp->channel + chan); 226 xxxp->channel[chan].hook = hook; 227 return (0); 228 } else if (strcmp(name, NG_XXX_HOOK_DOWNSTREAM) == 0) { 229 /* Example of simple predefined hooks. */ 230 /* do something specific to the downstream connection */ 231 xxxp->downstream_hook.hook = hook; 232 NG_HOOK_SET_PRIVATE(hook, &xxxp->downstream_hook); 233 } else if (strcmp(name, NG_XXX_HOOK_DEBUG) == 0) { 234 /* do something specific to a debug connection */ 235 xxxp->debughook = hook; 236 NG_HOOK_SET_PRIVATE(hook, NULL); 237 } else 238 return (EINVAL); /* not a hook we know about */ 239 return(0); 240 } 241 242 /* 243 * Get a netgraph control message. 244 * We actually receive a queue item that has a pointer to the message. 245 * If we free the item, the message will be freed too, unless we remove 246 * it from the item using NGI_GET_MSG(); 247 * The return address is also stored in the item, as an ng_ID_t, 248 * accessible as NGI_RETADDR(item); 249 * Check it is one we understand. If needed, send a response. 250 * We could save the address for an async action later, but don't here. 251 * Always free the message. 252 * The response should be in a malloc'd region that the caller can 'free'. 253 * A response is not required. 254 * Theoretically you could respond defferently to old message types if 255 * the cookie in the header didn't match what we consider to be current 256 * (so that old userland programs could continue to work). 257 */ 258 static int 259 ng_xxx_rcvmsg(node_p node, item_p item, hook_p lasthook) 260 { 261 const xxx_p xxxp = NG_NODE_PRIVATE(node); 262 struct ng_mesg *resp = NULL; 263 int error = 0; 264 struct ng_mesg *msg; 265 266 NGI_GET_MSG(item, msg); 267 /* Deal with message according to cookie and command */ 268 switch (msg->header.typecookie) { 269 case NGM_XXX_COOKIE: 270 switch (msg->header.cmd) { 271 case NGM_XXX_GET_STATUS: 272 { 273 struct ngxxxstat *stats; 274 275 NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT); 276 if (!resp) { 277 error = ENOMEM; 278 break; 279 } 280 stats = (struct ngxxxstat *) resp->data; 281 stats->packets_in = xxxp->packets_in; 282 stats->packets_out = xxxp->packets_out; 283 break; 284 } 285 case NGM_XXX_SET_FLAG: 286 if (msg->header.arglen != sizeof(u_int32_t)) { 287 error = EINVAL; 288 break; 289 } 290 xxxp->flags = *((u_int32_t *) msg->data); 291 break; 292 default: 293 error = EINVAL; /* unknown command */ 294 break; 295 } 296 break; 297 default: 298 error = EINVAL; /* unknown cookie type */ 299 break; 300 } 301 302 /* Take care of synchronous response, if any */ 303 NG_RESPOND_MSG(error, node, item, resp); 304 /* Free the message and return */ 305 NG_FREE_MSG(msg); 306 return(error); 307 } 308 309 /* 310 * Receive data, and do something with it. 311 * Actually we receive a queue item which holds the data. 312 * If we free the item it will also free the data unless we have 313 * previously disassociated it using the NGI_GET_M() macro. 314 * Possibly send it out on another link after processing. 315 * Possibly do something different if it comes from different 316 * hooks. The caller will never free m, so if we use up this data or 317 * abort we must free it. 318 * 319 * If we want, we may decide to force this data to be queued and reprocessed 320 * at the netgraph NETISR time. 321 * We would do that by setting the HK_QUEUE flag on our hook. We would do that 322 * in the connect() method. 323 */ 324 static int 325 ng_xxx_rcvdata(hook_p hook, item_p item ) 326 { 327 const xxx_p xxxp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 328 int chan = -2; 329 int dlci = -2; 330 int error; 331 struct mbuf *m; 332 333 NGI_GET_M(item, m); 334 if (NG_HOOK_PRIVATE(hook)) { 335 dlci = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->dlci; 336 chan = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->channel; 337 if (dlci != -1) { 338 /* If received on a DLCI hook process for this 339 * channel and pass it to the downstream module. 340 * Normally one would add a multiplexing header at 341 * the front here */ 342 /* M_PREPEND(....) ; */ 343 /* mtod(m, xxxxxx)->dlci = dlci; */ 344 NG_FWD_NEW_DATA(error, item, 345 xxxp->downstream_hook.hook, m); 346 xxxp->packets_out++; 347 } else { 348 /* data came from the multiplexed link */ 349 dlci = 1; /* get dlci from header */ 350 /* madjust(....) *//* chop off header */ 351 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 352 if (xxxp->channel[chan].dlci == dlci) 353 break; 354 if (chan == XXX_NUM_DLCIS) { 355 NG_FREE_ITEM(item); 356 NG_FREE_M(m); 357 return (ENETUNREACH); 358 } 359 /* If we were called at splnet, use the following: 360 * NG_SEND_DATA_ONLY(error, otherhook, m); if this 361 * node is running at some SPL other than SPLNET 362 * then you should use instead: error = 363 * ng_queueit(otherhook, m, NULL); m = NULL; 364 * This queues the data using the standard NETISR 365 * system and schedules the data to be picked 366 * up again once the system has moved to SPLNET and 367 * the processing of the data can continue. After 368 * these are run 'm' should be considered 369 * as invalid and NG_SEND_DATA actually zaps them. */ 370 NG_FWD_NEW_DATA(error, item, 371 xxxp->channel[chan].hook, m); 372 xxxp->packets_in++; 373 } 374 } else { 375 /* It's the debug hook, throw it away.. */ 376 if (hook == xxxp->downstream_hook.hook) { 377 NG_FREE_ITEM(item); 378 NG_FREE_M(m); 379 } 380 } 381 return 0; 382 } 383 384 #if 0 385 /* 386 * If this were a device node, the data may have been received in response 387 * to some interrupt. 388 * in which case it would probably look as follows: 389 */ 390 devintr() 391 { 392 int error; 393 394 /* get packet from device and send on */ 395 m = MGET(blah blah) 396 397 NG_SEND_DATA_ONLY(error, xxxp->upstream_hook.hook, m); 398 /* see note above in xxx_rcvdata() */ 399 /* and ng_xxx_connect() */ 400 } 401 402 #endif /* 0 */ 403 404 /* 405 * Do local shutdown processing.. 406 * All our links and the name have already been removed. 407 * If we are a persistent device, we might refuse to go away. 408 * In the case of a persistent node we signal the framework that we 409 * are still in business by clearing the NGF_INVALID bit. However 410 * If we find the NGF_REALLY_DIE bit set, this means that 411 * we REALLY need to die (e.g. hardware removed). 412 * This would have been set using the NG_NODE_REALLY_DIE(node) 413 * macro in some device dependent function (not shown here) before 414 * calling ng_rmnode_self(). 415 */ 416 static int 417 ng_xxx_shutdown(node_p node) 418 { 419 const xxx_p privdata = NG_NODE_PRIVATE(node); 420 421 #ifndef PERSISTANT_NODE 422 NG_NODE_SET_PRIVATE(node, NULL); 423 NG_NODE_UNREF(node); 424 free(privdata, M_NETGRAPH); 425 #else 426 if (node->nd_flags & NGF_REALLY_DIE) { 427 /* 428 * WE came here because the widget card is being unloaded, 429 * so stop being persistent. 430 * Actually undo all the things we did on creation. 431 */ 432 NG_NODE_SET_PRIVATE(node, NULL); 433 NG_NODE_UNREF(privdata->node); 434 free(privdata, M_NETGRAPH); 435 return (0); 436 } 437 NG_NODE_REVIVE(node); /* tell ng_rmnode() we will persist */ 438 #endif /* PERSISTANT_NODE */ 439 return (0); 440 } 441 442 /* 443 * This is called once we've already connected a new hook to the other node. 444 * It gives us a chance to balk at the last minute. 445 */ 446 static int 447 ng_xxx_connect(hook_p hook) 448 { 449 #if 0 450 /* 451 * If we were a driver running at other than splnet then 452 * we should set the QUEUE bit on the edge so that we 453 * will deliver by queing. 454 */ 455 if /*it is the upstream hook */ 456 NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook)); 457 #endif 458 #if 0 459 /* 460 * If for some reason we want incoming date to be queued 461 * by the NETISR system and delivered later we can set the same bit on 462 * OUR hook. (maybe to allow unwinding of the stack) 463 */ 464 465 if (NG_HOOK_PRIVATE(hook)) { 466 int dlci; 467 /* 468 * If it's dlci 1023, requeue it so that it's handled 469 * at a lower priority. This is how a node decides to 470 * defer a data message. 471 */ 472 dlci = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->dlci; 473 if (dlci == 1023) { 474 NG_HOOK_FORCE_QUEUE(hook); 475 } 476 #endif 477 /* otherwise be really amiable and just say "YUP that's OK by me! " */ 478 return (0); 479 } 480 481 /* 482 * Hook disconnection 483 * 484 * For this type, removal of the last link destroys the node 485 */ 486 static int 487 ng_xxx_disconnect(hook_p hook) 488 { 489 if (NG_HOOK_PRIVATE(hook)) 490 ((struct XXX_hookinfo *) (NG_HOOK_PRIVATE(hook)))->hook = NULL; 491 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 492 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) /* already shutting down? */ 493 ng_rmnode_self(NG_HOOK_NODE(hook)); 494 return (0); 495 } 496