ng_sample.c revision 70784
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: head/sys/netgraph/ng_sample.c 70784 2001-01-08 05:34:06Z julian $ 40 * $Whistle: ng_sample.c,v 1.13 1999/11/01 09:24:52 julian Exp $ 41 */ 42 43#include <sys/param.h> 44#include <sys/systm.h> 45#include <sys/kernel.h> 46#include <sys/mbuf.h> 47#include <sys/malloc.h> 48#include <sys/ctype.h> 49#include <sys/errno.h> 50#include <sys/syslog.h> 51 52#include <netgraph/ng_message.h> 53#include <netgraph/ng_parse.h> 54#include <netgraph/ng_sample.h> 55#include <netgraph/netgraph.h> 56 57/* 58 * This section contains the netgraph method declarations for the 59 * sample node. These methods define the netgraph 'type'. 60 */ 61 62static ng_constructor_t ng_xxx_constructor; 63static ng_rcvmsg_t ng_xxx_rcvmsg; 64static ng_shutdown_t ng_xxx_shutdown; 65static ng_newhook_t ng_xxx_newhook; 66static ng_connect_t ng_xxx_connect; 67static ng_rcvdata_t ng_xxx_rcvdata; /* note these are both ng_rcvdata_t */ 68static ng_disconnect_t ng_xxx_disconnect; 69 70/* Parse type for struct ngxxxstat */ 71static const struct ng_parse_struct_info 72 ng_xxx_stat_type_info = NG_XXX_STATS_TYPE_INFO; 73static const struct ng_parse_type ng_xxx_stat_type = { 74 &ng_parse_struct_type, 75 &ng_xxx_stat_type_info 76}; 77 78/* List of commands and how to convert arguments to/from ASCII */ 79static const struct ng_cmdlist ng_xxx_cmdlist[] = { 80 { 81 NGM_XXX_COOKIE, 82 NGM_XXX_GET_STATUS, 83 "getstatus", 84 NULL, 85 &ng_xxx_stat_type, 86 }, 87 { 88 NGM_XXX_COOKIE, 89 NGM_XXX_SET_FLAG, 90 "setflag", 91 &ng_parse_int32_type, 92 NULL 93 }, 94 { 0 } 95}; 96 97/* Netgraph node type descriptor */ 98static struct ng_type typestruct = { 99 NG_ABI_VERSION, 100 NG_XXX_NODE_TYPE, 101 NULL, 102 ng_xxx_constructor, 103 ng_xxx_rcvmsg, 104 ng_xxx_shutdown, 105 ng_xxx_newhook, 106 NULL, 107 ng_xxx_connect, 108 ng_xxx_rcvdata, 109 ng_xxx_disconnect, 110 ng_xxx_cmdlist 111}; 112NETGRAPH_INIT(xxx, &typestruct); 113 114/* Information we store for each hook on each node */ 115struct XXX_hookinfo { 116 int dlci; /* The DLCI it represents, -1 == downstream */ 117 int channel; /* The channel representing this DLCI */ 118 hook_p hook; 119}; 120 121/* Information we store for each node */ 122struct XXX { 123 struct XXX_hookinfo channel[XXX_NUM_DLCIS]; 124 struct XXX_hookinfo downstream_hook; 125 node_p node; /* back pointer to node */ 126 hook_p debughook; 127 u_int packets_in; /* packets in from downstream */ 128 u_int packets_out; /* packets out towards downstream */ 129 u_int32_t flags; 130}; 131typedef struct XXX *xxx_p; 132 133/* 134 * Allocate the private data structure. The generic node has already 135 * been created. Link them together. We arrive with a reference to the node 136 * i.e. the reference count is incremented for us already. 137 * 138 * If this were a device node than this work would be done in the attach() 139 * routine and the constructor would return EINVAL as you should not be able 140 * to creatednodes that depend on hardware (unless you can add the hardware :) 141 */ 142static int 143ng_xxx_constructor(node_p node) 144{ 145 xxx_p privdata; 146 int i, error; 147 148 /* Initialize private descriptor */ 149 MALLOC(privdata, xxx_p, sizeof(*privdata), M_NETGRAPH, 150 M_NOWAIT | M_ZERO); 151 if (privdata == NULL) 152 return (ENOMEM); 153 for (i = 0; i < XXX_NUM_DLCIS; i++) { 154 privdata->channel[i].dlci = -2; 155 privdata->channel[i].channel = i; 156 } 157 158 /* Link structs together; this counts as our one reference to *nodep */ 159 NG_NODE_PRIVATE(node) = privdata; 160 privdata->node = node; 161 return (0); 162} 163 164/* 165 * Give our ok for a hook to be added... 166 * If we are not running this might kick a device into life. 167 * Possibly decode information out of the hook name. 168 * Add the hook's private info to the hook structure. 169 * (if we had some). In this example, we assume that there is a 170 * an array of structs, called 'channel' in the private info, 171 * one for each active channel. The private 172 * pointer of each hook points to the appropriate XXX_hookinfo struct 173 * so that the source of an input packet is easily identified. 174 * (a dlci is a frame relay channel) 175 */ 176static int 177ng_xxx_newhook(node_p node, hook_p hook, const char *name) 178{ 179 const xxx_p xxxp = NG_NODE_PRIVATE(node); 180 const char *cp; 181 int dlci = 0; 182 int chan; 183 184#if 0 185 /* Possibly start up the device if it's not already going */ 186 if ((xxxp->flags & SCF_RUNNING) == 0) { 187 ng_xxx_start_hardware(xxxp); 188 } 189#endif 190 191 /* Example of how one might use hooks with embedded numbers: All 192 * hooks start with 'dlci' and have a decimal trailing channel 193 * number up to 4 digits Use the leadin defined int he associated .h 194 * file. */ 195 if (strncmp(name, 196 NG_XXX_HOOK_DLCI_LEADIN, strlen(NG_XXX_HOOK_DLCI_LEADIN)) == 0) { 197 char *eptr; 198 199 cp = name + sizeof(NG_XXX_HOOK_DLCI_LEADIN); 200 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) 201 return (EINVAL); 202 dlci = (int)strtoul(cp, &eptr, 10); 203 if (*eptr != '\0' || dlci < 0 || dlci > 1023) 204 return (EINVAL); 205 206 /* We have a dlci, now either find it, or allocate it */ 207 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 208 if (xxxp->channel[chan].dlci == dlci) 209 break; 210 if (chan == XXX_NUM_DLCIS) { 211 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 212 if (xxxp->channel[chan].dlci != -2) 213 continue; 214 if (chan == XXX_NUM_DLCIS) 215 return (ENOBUFS); 216 } 217 if (xxxp->channel[chan].hook != NULL) 218 return (EADDRINUSE); 219 NG_HOOK_SET_PRIVATE(hook, xxxp->channel + chan); 220 xxxp->channel[chan].hook = hook; 221 return (0); 222 } else if (strcmp(name, NG_XXX_HOOK_DOWNSTREAM) == 0) { 223 /* Example of simple predefined hooks. */ 224 /* do something specific to the downstream connection */ 225 xxxp->downstream_hook.hook = hook; 226 NG_HOOK_SET_PRIVATE(hook, &xxxp->downstream_hook); 227 } else if (strcmp(name, NG_XXX_HOOK_DEBUG) == 0) { 228 /* do something specific to a debug connection */ 229 xxxp->debughook = hook; 230 NG_HOOK_SET_PRIVATE(hook, NULL); 231 } else 232 return (EINVAL); /* not a hook we know about */ 233 return(0); 234} 235 236/* 237 * Get a netgraph control message. 238 * We actually recieve a queue item that has a pointer to the message. 239 * If we free the item, the message will be freed too, unless we remove 240 * it from the item using NGI_GET_MSG(); 241 * The return address is also stored in the item, as an ng_ID_t, 242 * accessible as NGI_RETADDR(item); 243 * Check it is one we understand. If needed, send a response. 244 * We could save the address for an async action later, but don't here. 245 * Always free the message. 246 * The response should be in a malloc'd region that the caller can 'free'. 247 * A response is not required. 248 * Theoretically you could respond defferently to old message types if 249 * the cookie in the header didn't match what we consider to be current 250 * (so that old userland programs could continue to work). 251 */ 252static int 253ng_xxx_rcvmsg(node_p node, item_p item, hook_p lasthook) 254{ 255 const xxx_p xxxp = NG_NODE_PRIVATE(node); 256 struct ng_mesg *resp = NULL; 257 int error = 0; 258 struct ng_mesg *msg; 259 260 NGI_GET_MSG(item, msg); 261 /* Deal with message according to cookie and command */ 262 switch (msg->header.typecookie) { 263 case NGM_XXX_COOKIE: 264 switch (msg->header.cmd) { 265 case NGM_XXX_GET_STATUS: 266 { 267 struct ngxxxstat *stats; 268 269 NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT); 270 if (!resp) { 271 error = ENOMEM; 272 break; 273 } 274 stats = (struct ngxxxstat *) resp->data; 275 stats->packets_in = xxxp->packets_in; 276 stats->packets_out = xxxp->packets_out; 277 break; 278 } 279 case NGM_XXX_SET_FLAG: 280 if (msg->header.arglen != sizeof(u_int32_t)) { 281 error = EINVAL; 282 break; 283 } 284 xxxp->flags = *((u_int32_t *) msg->data); 285 break; 286 default: 287 error = EINVAL; /* unknown command */ 288 break; 289 } 290 break; 291 default: 292 error = EINVAL; /* unknown cookie type */ 293 break; 294 } 295 296 /* Take care of synchronous response, if any */ 297 NG_RESPOND_MSG(error, node, item, resp); 298 /* Free the message and return */ 299 NG_FREE_MSG(msg); 300 return(error); 301} 302 303/* 304 * Receive data, and do something with it. 305 * Actually we receive a queue item which holds the data. 306 * If we free the item it wil also froo the data and metadata unless 307 * we have previously disassociated them using the NGI_GET_xxx() macros. 308 * Possibly send it out on another link after processing. 309 * Possibly do something different if it comes from different 310 * hooks. the caller will never free m or meta, so 311 * if we use up this data or abort we must free BOTH of these. 312 * 313 * If we want, we may decide to force this data to be queued and reprocessed 314 * at the netgraph NETISR time. 315 * We would do that by setting the HK_QUEUE flag on our hook. We would do that 316 * in the connect() method. 317 */ 318static int 319ng_xxx_rcvdata(hook_p hook, item_p item ) 320{ 321 const xxx_p xxxp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 322 int chan = -2; 323 int dlci = -2; 324 int error; 325 struct mbuf *m; 326 meta_p meta; 327 328 329 NGI_GET_M(item, m); 330 if (NG_HOOK_PRIVATE(hook)) { 331 dlci = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->dlci; 332 chan = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->channel; 333 if (dlci != -1) { 334 /* If received on a DLCI hook process for this 335 * channel and pass it to the downstream module. 336 * Normally one would add a multiplexing header at 337 * the front here */ 338 /* M_PREPEND(....) ; */ 339 /* mtod(m, xxxxxx)->dlci = dlci; */ 340 NG_FWD_NEW_DATA(error, item, 341 xxxp->downstream_hook.hook, m); 342 xxxp->packets_out++; 343 } else { 344 /* data came from the multiplexed link */ 345 dlci = 1; /* get dlci from header */ 346 /* madjust(....) *//* chop off header */ 347 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 348 if (xxxp->channel[chan].dlci == dlci) 349 break; 350 if (chan == XXX_NUM_DLCIS) { 351 NG_FREE_ITEM(item); 352 NG_FREE_M(m); 353 return (ENETUNREACH); 354 } 355 /* If we were called at splnet, use the following: 356 * NG_SEND_DATA(error, otherhook, m, meta); if this 357 * node is running at some SPL other than SPLNET 358 * then you should use instead: error = 359 * ng_queueit(otherhook, m, meta); m = NULL: meta = 360 * NULL; this queues the data using the standard 361 * NETISR system and schedules the data to be picked 362 * up again once the system has moved to SPLNET and 363 * the processing of the data can continue. after 364 * these are run 'm' and 'meta' should be considered 365 * as invalid and NG_SEND_DATA actually zaps them. */ 366 NG_FWD_NEW_DATA(error, item, 367 xxxp->channel[chan].hook, m); 368 xxxp->packets_in++; 369 } 370 } else { 371 /* It's the debug hook, throw it away.. */ 372 if (hook == xxxp->downstream_hook.hook) 373 NG_FREE_ITEM(item); 374 NG_FREE_M(m); 375 } 376 return 0; 377} 378 379#if 0 380/* 381 * If this were a device node, the data may have been received in response 382 * to some interrupt. 383 * in which case it would probably look as follows: 384 */ 385devintr() 386{ 387 int error; 388 * here */ 389 390 /* get packet from device and send on */ 391 m = MGET(blah blah) 392 393 NG_SEND_DATA_ONLY(error, xxxp->upstream_hook.hook, m); 394 /* see note above in xxx_rcvdata() */ 395 /* and ng_xxx_connect() */ 396} 397 398#endif /* 0 */ 399 400/* 401 * Do local shutdown processing.. 402 * All our links and the name have already been removed. 403 * If we are a persistant device, we might refuse to go away, and 404 * we'd create a new node immediatly. 405 */ 406static int 407ng_xxx_shutdown(node_p node) 408{ 409 const xxx_p privdata = NG_NODE_PRIVATE(node); 410 int error; 411 412 NG_NODE_SET_PRIVATE(node, NULL); 413 NG_NODE_UNREF(privdata->node); 414#ifndef PERSISTANT_NODE 415 FREE(privdata, M_NETGRAPH); 416#else 417 /* 418 * Create a new node. This is basically what a device 419 * driver would do in the attach routine. 420 */ 421 error = ng_make_node_common(&typestruct, &node); 422 if (node == NULL) { 423 printf ("node recreation failed:"); 424 return (error); 425 } 426 if ( ng_name_node(node, "name")) { /* whatever name is needed */ 427 printf("something informative"); 428 NG_NODE_UNREF(node); /* drop it again */ 429 return (0); 430 } 431 privdata->packets_in = 0; /* reset stats */ 432 privdata->packets_out = 0; 433 for (i = 0; i < XXX_NUM_DLCIS; i++) { 434 privdata->channel[i].dlci = -2; 435 privdata->channel[i].channel = i; 436 } 437 438 /* Link structs together; this counts as our one reference to node */ 439 privdata->node = node; 440 NG_NODE_SET_PRIVATE(node, privdata); 441 node->nd_flags &= ~NG_INVALID; /* reset invalid flag */ 442#endif /* PERSISTANT_NODE */ 443 return (0); 444} 445 446/* 447 * This is called once we've already connected a new hook to the other node. 448 * It gives us a chance to balk at the last minute. 449 */ 450static int 451ng_xxx_connect(hook_p hook) 452{ 453#if 0 454 /* 455 * If we were a driver running at other than splnet then 456 * we should set the QUEUE bit on the edge so that we 457 * will deliver by queing. 458 */ 459 if /*it is the upstream hook */ 460 NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook)); 461#endif 462#if 0 463 /* 464 * If for some reason we want incoming date to be queued 465 * by the NETISR system and delivered later we can set the same bit on 466 * OUR hook. (maybe to allow unwinding of the stack) 467 */ 468 469 if (NG_HOOK_PRIVATE(hook)) { 470 int dlci; 471 /* 472 * If it's dlci 1023, requeue it so that it's handled 473 * at a lower priority. This is how a node decides to 474 * defer a data message. 475 */ 476 dlci = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->dlci; 477 if (dlci == 1023) { 478 NG_HOOK_FORCE_QUEUE(hook); 479 } 480#endif 481 /* otherwise be really amiable and just say "YUP that's OK by me! " */ 482 return (0); 483} 484 485/* 486 * Dook disconnection 487 * 488 * For this type, removal of the last link destroys the node 489 */ 490static int 491ng_xxx_disconnect(hook_p hook) 492{ 493 if (NG_HOOK_PRIVATE(hook)) 494 ((struct XXX_hookinfo *) (NG_HOOK_PRIVATE(hook)))->hook = NULL; 495 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 496 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) /* already shutting down? */ 497 ng_rmnode_self(NG_HOOK_NODE(hook)); 498 return (0); 499} 500 501