ng_sample.c revision 71849
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 71849 2001-01-30 20:51:52Z 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/* If you do complicated mallocs you may want to do this */ 58/* and use it for your mallocs */ 59#ifdef NG_SEPARATE_MALLOC 60MALLOC_DEFINE(M_NETGRAPH_XXX, "netgraph_xxx", "netgraph xxx node "); 61#else 62#define M_NETGRAPH_XXX M_NETGRAPH 63#endif 64 65/* 66 * This section contains the netgraph method declarations for the 67 * sample node. These methods define the netgraph 'type'. 68 */ 69 70static ng_constructor_t ng_xxx_constructor; 71static ng_rcvmsg_t ng_xxx_rcvmsg; 72static ng_shutdown_t ng_xxx_shutdown; 73static ng_newhook_t ng_xxx_newhook; 74static ng_connect_t ng_xxx_connect; 75static ng_rcvdata_t ng_xxx_rcvdata; /* note these are both ng_rcvdata_t */ 76static ng_disconnect_t ng_xxx_disconnect; 77 78/* Parse type for struct ngxxxstat */ 79static const struct ng_parse_struct_info 80 ng_xxx_stat_type_info = NG_XXX_STATS_TYPE_INFO; 81static const struct ng_parse_type ng_xxx_stat_type = { 82 &ng_parse_struct_type, 83 &ng_xxx_stat_type_info 84}; 85 86/* List of commands and how to convert arguments to/from ASCII */ 87static const struct ng_cmdlist ng_xxx_cmdlist[] = { 88 { 89 NGM_XXX_COOKIE, 90 NGM_XXX_GET_STATUS, 91 "getstatus", 92 NULL, 93 &ng_xxx_stat_type, 94 }, 95 { 96 NGM_XXX_COOKIE, 97 NGM_XXX_SET_FLAG, 98 "setflag", 99 &ng_parse_int32_type, 100 NULL 101 }, 102 { 0 } 103}; 104 105/* Netgraph node type descriptor */ 106static struct ng_type typestruct = { 107 NG_ABI_VERSION, 108 NG_XXX_NODE_TYPE, 109 NULL, 110 ng_xxx_constructor, 111 ng_xxx_rcvmsg, 112 ng_xxx_shutdown, 113 ng_xxx_newhook, 114 NULL, 115 ng_xxx_connect, 116 ng_xxx_rcvdata, 117 ng_xxx_disconnect, 118 ng_xxx_cmdlist 119}; 120NETGRAPH_INIT(xxx, &typestruct); 121 122/* Information we store for each hook on each node */ 123struct 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 */ 130struct 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}; 139typedef 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 */ 150static int 151ng_xxx_constructor(node_p node) 152{ 153 xxx_p privdata; 154 int i, error; 155 156 /* Initialize private descriptor */ 157 MALLOC(privdata, xxx_p, sizeof(*privdata), M_NETGRAPH, 158 M_NOWAIT | M_ZERO); 159 if (privdata == NULL) 160 return (ENOMEM); 161 for (i = 0; i < XXX_NUM_DLCIS; i++) { 162 privdata->channel[i].dlci = -2; 163 privdata->channel[i].channel = i; 164 } 165 166 /* Link structs together; this counts as our one reference to *nodep */ 167 NG_NODE_PRIVATE(node) = privdata; 168 privdata->node = node; 169 return (0); 170} 171 172/* 173 * Give our ok for a hook to be added... 174 * If we are not running this might kick a device into life. 175 * Possibly decode information out of the hook name. 176 * Add the hook's private info to the hook structure. 177 * (if we had some). In this example, we assume that there is a 178 * an array of structs, called 'channel' in the private info, 179 * one for each active channel. The private 180 * pointer of each hook points to the appropriate XXX_hookinfo struct 181 * so that the source of an input packet is easily identified. 182 * (a dlci is a frame relay channel) 183 */ 184static int 185ng_xxx_newhook(node_p node, hook_p hook, const char *name) 186{ 187 const xxx_p xxxp = NG_NODE_PRIVATE(node); 188 const char *cp; 189 int dlci = 0; 190 int chan; 191 192#if 0 193 /* Possibly start up the device if it's not already going */ 194 if ((xxxp->flags & SCF_RUNNING) == 0) { 195 ng_xxx_start_hardware(xxxp); 196 } 197#endif 198 199 /* Example of how one might use hooks with embedded numbers: All 200 * hooks start with 'dlci' and have a decimal trailing channel 201 * number up to 4 digits Use the leadin defined int he associated .h 202 * file. */ 203 if (strncmp(name, 204 NG_XXX_HOOK_DLCI_LEADIN, strlen(NG_XXX_HOOK_DLCI_LEADIN)) == 0) { 205 char *eptr; 206 207 cp = name + sizeof(NG_XXX_HOOK_DLCI_LEADIN); 208 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) 209 return (EINVAL); 210 dlci = (int)strtoul(cp, &eptr, 10); 211 if (*eptr != '\0' || dlci < 0 || dlci > 1023) 212 return (EINVAL); 213 214 /* We have a dlci, now either find it, or allocate it */ 215 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 216 if (xxxp->channel[chan].dlci == dlci) 217 break; 218 if (chan == XXX_NUM_DLCIS) { 219 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 220 if (xxxp->channel[chan].dlci != -2) 221 continue; 222 if (chan == XXX_NUM_DLCIS) 223 return (ENOBUFS); 224 } 225 if (xxxp->channel[chan].hook != NULL) 226 return (EADDRINUSE); 227 NG_HOOK_SET_PRIVATE(hook, xxxp->channel + chan); 228 xxxp->channel[chan].hook = hook; 229 return (0); 230 } else if (strcmp(name, NG_XXX_HOOK_DOWNSTREAM) == 0) { 231 /* Example of simple predefined hooks. */ 232 /* do something specific to the downstream connection */ 233 xxxp->downstream_hook.hook = hook; 234 NG_HOOK_SET_PRIVATE(hook, &xxxp->downstream_hook); 235 } else if (strcmp(name, NG_XXX_HOOK_DEBUG) == 0) { 236 /* do something specific to a debug connection */ 237 xxxp->debughook = hook; 238 NG_HOOK_SET_PRIVATE(hook, NULL); 239 } else 240 return (EINVAL); /* not a hook we know about */ 241 return(0); 242} 243 244/* 245 * Get a netgraph control message. 246 * We actually recieve a queue item that has a pointer to the message. 247 * If we free the item, the message will be freed too, unless we remove 248 * it from the item using NGI_GET_MSG(); 249 * The return address is also stored in the item, as an ng_ID_t, 250 * accessible as NGI_RETADDR(item); 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 */ 260static int 261ng_xxx_rcvmsg(node_p node, item_p item, hook_p lasthook) 262{ 263 const xxx_p xxxp = NG_NODE_PRIVATE(node); 264 struct ng_mesg *resp = NULL; 265 int error = 0; 266 struct ng_mesg *msg; 267 268 NGI_GET_MSG(item, msg); 269 /* Deal with message according to cookie and command */ 270 switch (msg->header.typecookie) { 271 case NGM_XXX_COOKIE: 272 switch (msg->header.cmd) { 273 case NGM_XXX_GET_STATUS: 274 { 275 struct ngxxxstat *stats; 276 277 NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT); 278 if (!resp) { 279 error = ENOMEM; 280 break; 281 } 282 stats = (struct ngxxxstat *) resp->data; 283 stats->packets_in = xxxp->packets_in; 284 stats->packets_out = xxxp->packets_out; 285 break; 286 } 287 case NGM_XXX_SET_FLAG: 288 if (msg->header.arglen != sizeof(u_int32_t)) { 289 error = EINVAL; 290 break; 291 } 292 xxxp->flags = *((u_int32_t *) msg->data); 293 break; 294 default: 295 error = EINVAL; /* unknown command */ 296 break; 297 } 298 break; 299 default: 300 error = EINVAL; /* unknown cookie type */ 301 break; 302 } 303 304 /* Take care of synchronous response, if any */ 305 NG_RESPOND_MSG(error, node, item, resp); 306 /* Free the message and return */ 307 NG_FREE_MSG(msg); 308 return(error); 309} 310 311/* 312 * Receive data, and do something with it. 313 * Actually we receive a queue item which holds the data. 314 * If we free the item it wil also froo the data and metadata unless 315 * we have previously disassociated them using the NGI_GET_xxx() macros. 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. 323 * We would do that by setting the HK_QUEUE flag on our hook. We would do that 324 * in the connect() method. 325 */ 326static int 327ng_xxx_rcvdata(hook_p hook, item_p item ) 328{ 329 const xxx_p xxxp = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 330 int chan = -2; 331 int dlci = -2; 332 int error; 333 struct mbuf *m; 334 meta_p meta; 335 336 337 NGI_GET_M(item, m); 338 if (NG_HOOK_PRIVATE(hook)) { 339 dlci = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->dlci; 340 chan = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->channel; 341 if (dlci != -1) { 342 /* If received on a DLCI hook process for this 343 * channel and pass it to the downstream module. 344 * Normally one would add a multiplexing header at 345 * the front here */ 346 /* M_PREPEND(....) ; */ 347 /* mtod(m, xxxxxx)->dlci = dlci; */ 348 NG_FWD_NEW_DATA(error, item, 349 xxxp->downstream_hook.hook, m); 350 xxxp->packets_out++; 351 } else { 352 /* data came from the multiplexed link */ 353 dlci = 1; /* get dlci from header */ 354 /* madjust(....) *//* chop off header */ 355 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 356 if (xxxp->channel[chan].dlci == dlci) 357 break; 358 if (chan == XXX_NUM_DLCIS) { 359 NG_FREE_ITEM(item); 360 NG_FREE_M(m); 361 return (ENETUNREACH); 362 } 363 /* If we were called at splnet, use the following: 364 * NG_SEND_DATA(error, otherhook, m, meta); if this 365 * node is running at some SPL other than SPLNET 366 * then you should use instead: error = 367 * ng_queueit(otherhook, m, meta); m = NULL: meta = 368 * NULL; this queues the data using the standard 369 * NETISR system and schedules the data to be picked 370 * up again once the system has moved to SPLNET and 371 * the processing of the data can continue. after 372 * these are run 'm' and 'meta' should be considered 373 * as invalid and NG_SEND_DATA actually zaps them. */ 374 NG_FWD_NEW_DATA(error, item, 375 xxxp->channel[chan].hook, m); 376 xxxp->packets_in++; 377 } 378 } else { 379 /* It's the debug hook, throw it away.. */ 380 if (hook == xxxp->downstream_hook.hook) { 381 NG_FREE_ITEM(item); 382 NG_FREE_M(m); 383 } 384 } 385 return 0; 386} 387 388#if 0 389/* 390 * If this were a device node, the data may have been received in response 391 * to some interrupt. 392 * in which case it would probably look as follows: 393 */ 394devintr() 395{ 396 int error; 397 * here */ 398 399 /* get packet from device and send on */ 400 m = MGET(blah blah) 401 402 NG_SEND_DATA_ONLY(error, xxxp->upstream_hook.hook, m); 403 /* see note above in xxx_rcvdata() */ 404 /* and ng_xxx_connect() */ 405} 406 407#endif /* 0 */ 408 409/* 410 * Do local shutdown processing.. 411 * All our links and the name have already been removed. 412 * If we are a persistant device, we might refuse to go away. 413 * In the case of a persistant node we signal the framework that we 414 * are still in business by clearing the NG_INVALID bit. However 415 * If we find the NG_REALLY_DIE bit set, this means that 416 * we REALLY need to die (e.g. hardware removed). 417 * This would have been set using the NG_NODE_REALLY_DIE(node) 418 * macro in some device dependent function (not shown here) before 419 * calling ng_rmnode_self(). 420 */ 421static int 422ng_xxx_shutdown(node_p node) 423{ 424 const xxx_p privdata = NG_NODE_PRIVATE(node); 425 int error; 426 427#ifndef PERSISTANT_NODE 428 NG_NODE_SET_PRIVATE(node, NULL); 429 NG_NODE_UNREF(privdata->node); 430 FREE(privdata, M_NETGRAPH); 431#else 432 if (node->nd_flags & NG_REALLY_DIE) { 433 /* 434 * WE came here because the widget card is being unloaded, 435 * so stop being persistant. 436 * Actually undo all the things we did on creation. 437 */ 438 NG_NODE_SET_PRIVATE(node, NULL); 439 NG_NODE_UNREF(privdata->node); 440 FREE(privdata, M_NETGRAPH); 441 return (0); 442 } 443 node->nd_flags &= ~NG_INVALID; /* reset invalid flag */ 444#endif /* PERSISTANT_NODE */ 445 return (0); 446} 447 448/* 449 * This is called once we've already connected a new hook to the other node. 450 * It gives us a chance to balk at the last minute. 451 */ 452static int 453ng_xxx_connect(hook_p hook) 454{ 455#if 0 456 /* 457 * If we were a driver running at other than splnet then 458 * we should set the QUEUE bit on the edge so that we 459 * will deliver by queing. 460 */ 461 if /*it is the upstream hook */ 462 NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook)); 463#endif 464#if 0 465 /* 466 * If for some reason we want incoming date to be queued 467 * by the NETISR system and delivered later we can set the same bit on 468 * OUR hook. (maybe to allow unwinding of the stack) 469 */ 470 471 if (NG_HOOK_PRIVATE(hook)) { 472 int dlci; 473 /* 474 * If it's dlci 1023, requeue it so that it's handled 475 * at a lower priority. This is how a node decides to 476 * defer a data message. 477 */ 478 dlci = ((struct XXX_hookinfo *) NG_HOOK_PRIVATE(hook))->dlci; 479 if (dlci == 1023) { 480 NG_HOOK_FORCE_QUEUE(hook); 481 } 482#endif 483 /* otherwise be really amiable and just say "YUP that's OK by me! " */ 484 return (0); 485} 486 487/* 488 * Dook disconnection 489 * 490 * For this type, removal of the last link destroys the node 491 */ 492static int 493ng_xxx_disconnect(hook_p hook) 494{ 495 if (NG_HOOK_PRIVATE(hook)) 496 ((struct XXX_hookinfo *) (NG_HOOK_PRIVATE(hook)))->hook = NULL; 497 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0) 498 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook)))) /* already shutting down? */ 499 ng_rmnode_self(NG_HOOK_NODE(hook)); 500 return (0); 501} 502 503