ng_sample.c revision 70159
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 70159 2000-12-18 20:03:32Z 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_rmnode; 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_rmnode, 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 and the generic node 135 * and link them together. 136 * 137 * ng_make_node_common() returns with a generic node struct 138 * with a single reference for us.. we transfer it to the 139 * private structure.. when we free the private struct we must 140 * unref the node so it gets freed too. 141 * 142 * If this were a device node than this work would be done in the attach() 143 * routine and the constructor would return EINVAL as you should not be able 144 * to creatednodes that depend on hardware (unless you can add the hardware :) 145 */ 146static int 147ng_xxx_constructor(node_p *nodep) 148{ 149 xxx_p privdata; 150 int i, error; 151 152 /* Initialize private descriptor */ 153 MALLOC(privdata, xxx_p, sizeof(*privdata), M_NETGRAPH, 154 M_NOWAIT | M_ZERO); 155 if (privdata == NULL) 156 return (ENOMEM); 157 for (i = 0; i < XXX_NUM_DLCIS; i++) { 158 privdata->channel[i].dlci = -2; 159 privdata->channel[i].channel = i; 160 } 161 162 /* Call the 'generic' (ie, superclass) node constructor */ 163 if ((error = ng_make_node_common(&typestruct, nodep))) { 164 FREE(privdata, M_NETGRAPH); 165 return (error); 166 } 167 168 /* Link structs together; this counts as our one reference to *nodep */ 169 (*nodep)->private = privdata; 170 privdata->node = *nodep; 171 return (0); 172} 173 174/* 175 * Give our ok for a hook to be added... 176 * If we are not running this might kick a device into life. 177 * Possibly decode information out of the hook name. 178 * Add the hook's private info to the hook structure. 179 * (if we had some). In this example, we assume that there is a 180 * an array of structs, called 'channel' in the private info, 181 * one for each active channel. The private 182 * pointer of each hook points to the appropriate XXX_hookinfo struct 183 * so that the source of an input packet is easily identified. 184 * (a dlci is a frame relay channel) 185 */ 186static int 187ng_xxx_newhook(node_p node, hook_p hook, const char *name) 188{ 189 const xxx_p xxxp = node->private; 190 const char *cp; 191 int dlci = 0; 192 int chan; 193 194#if 0 195 /* Possibly start up the device if it's not already going */ 196 if ((xxxp->flags & SCF_RUNNING) == 0) { 197 ng_xxx_start_hardware(xxxp); 198 } 199#endif 200 201 /* Example of how one might use hooks with embedded numbers: All 202 * hooks start with 'dlci' and have a decimal trailing channel 203 * number up to 4 digits Use the leadin defined int he associated .h 204 * file. */ 205 if (strncmp(name, 206 NG_XXX_HOOK_DLCI_LEADIN, strlen(NG_XXX_HOOK_DLCI_LEADIN)) == 0) { 207 char *eptr; 208 209 cp = name + sizeof(NG_XXX_HOOK_DLCI_LEADIN); 210 if (!isdigit(*cp) || (cp[0] == '0' && cp[1] != '\0')) 211 return (EINVAL); 212 dlci = (int)strtoul(cp, &eptr, 10); 213 if (*eptr != '\0' || dlci < 0 || dlci > 1023) 214 return (EINVAL); 215 216 /* We have a dlci, now either find it, or allocate it */ 217 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 218 if (xxxp->channel[chan].dlci == dlci) 219 break; 220 if (chan == XXX_NUM_DLCIS) { 221 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 222 if (xxxp->channel[chan].dlci != -2) 223 continue; 224 if (chan == XXX_NUM_DLCIS) 225 return (ENOBUFS); 226 } 227 if (xxxp->channel[chan].hook != NULL) 228 return (EADDRINUSE); 229 hook->private = xxxp->channel + chan; 230 xxxp->channel[chan].hook = hook; 231 return (0); 232 } else if (strcmp(name, NG_XXX_HOOK_DOWNSTREAM) == 0) { 233 /* Example of simple predefined hooks. */ 234 /* do something specific to the downstream connection */ 235 xxxp->downstream_hook.hook = hook; 236 hook->private = &xxxp->downstream_hook; 237 } else if (strcmp(name, NG_XXX_HOOK_DEBUG) == 0) { 238 /* do something specific to a debug connection */ 239 xxxp->debughook = hook; 240 hook->private = NULL; 241 } else 242 return (EINVAL); /* not a hook we know about */ 243 return(0); 244} 245 246/* 247 * Get a netgraph control message. 248 * Check it is one we understand. If needed, send a response. 249 * We could save the address for an async action later, but don't here. 250 * Always free the message. 251 * The response should be in a malloc'd region that the caller can 'free'. 252 * A response is not required. 253 * Theoretically you could respond defferently to old message types if 254 * the cookie in the header didn't match what we consider to be current 255 * (so that old userland programs could continue to work). 256 */ 257static int 258ng_xxx_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr, 259 struct ng_mesg **rptr, hook_p lasthook) 260{ 261 const xxx_p xxxp = node->private; 262 struct ng_mesg *resp = NULL; 263 int error = 0; 264 265 /* Deal with message according to cookie and command */ 266 switch (msg->header.typecookie) { 267 case NGM_XXX_COOKIE: 268 switch (msg->header.cmd) { 269 case NGM_XXX_GET_STATUS: 270 { 271 struct ngxxxstat *stats; 272 273 NG_MKRESPONSE(resp, msg, sizeof(*stats), M_NOWAIT); 274 if (!resp) { 275 error = ENOMEM; 276 break; 277 } 278 stats = (struct ngxxxstat *) resp->data; 279 stats->packets_in = xxxp->packets_in; 280 stats->packets_out = xxxp->packets_out; 281 break; 282 } 283 case NGM_XXX_SET_FLAG: 284 if (msg->header.arglen != sizeof(u_int32_t)) { 285 error = EINVAL; 286 break; 287 } 288 xxxp->flags = *((u_int32_t *) msg->data); 289 break; 290 default: 291 error = EINVAL; /* unknown command */ 292 break; 293 } 294 break; 295 default: 296 error = EINVAL; /* unknown cookie type */ 297 break; 298 } 299 300 /* Take care of synchronous response, if any */ 301 if (rptr) 302 *rptr = resp; 303 else if (resp) 304 FREE(resp, M_NETGRAPH); 305 306 /* Free the message and return */ 307 FREE(msg, M_NETGRAPH); 308 return(error); 309} 310 311/* 312 * Receive data, and do something with it. 313 * Possibly send it out on another link after processing. 314 * Possibly do something different if it comes from different 315 * hooks. the caller will never free m or meta, so 316 * if we use up this data or abort we must free BOTH of these. 317 * 318 * If we want, we may decide to force this data to be queued and reprocessed 319 * at the netgraph NETISR time. 320 * We would do that by setting the HK_QUEUE flag on our hook. We would do that 321 * in the connect() method. 322 */ 323static int 324ng_xxx_rcvdata(hook_p hook, struct mbuf *m, meta_p meta, 325 struct mbuf **ret_m, meta_p *ret_meta, struct ng_mesg **resp) 326{ 327 const xxx_p xxxp = hook->node->private; 328 int chan = -2; 329 int dlci = -2; 330 int error; 331 332 if (hook->private) { 333 dlci = ((struct XXX_hookinfo *) hook->private)->dlci; 334 chan = ((struct XXX_hookinfo *) hook->private)->channel; 335 if (dlci != -1) { 336 /* If received on a DLCI hook process for this 337 * channel and pass it to the downstream module. 338 * Normally one would add a multiplexing header at 339 * the front here */ 340 /* M_PREPEND(....) ; */ 341 /* mtod(m, xxxxxx)->dlci = dlci; */ 342 NG_SEND_DATA(error, xxxp->downstream_hook.hook, 343 m, meta); 344 xxxp->packets_out++; 345 } else { 346 /* data came from the multiplexed link */ 347 dlci = 1; /* get dlci from header */ 348 /* madjust(....) *//* chop off header */ 349 for (chan = 0; chan < XXX_NUM_DLCIS; chan++) 350 if (xxxp->channel[chan].dlci == dlci) 351 break; 352 if (chan == XXX_NUM_DLCIS) { 353 NG_FREE_DATA(m, meta); 354 return (ENETUNREACH); 355 } 356 /* If we were called at splnet, use the following: 357 * NG_SEND_DATA(error, otherhook, m, meta); if this 358 * node is running at some SPL other than SPLNET 359 * then you should use instead: error = 360 * ng_queueit(otherhook, m, meta); m = NULL: meta = 361 * NULL; this queues the data using the standard 362 * NETISR system and schedules the data to be picked 363 * up again once the system has moved to SPLNET and 364 * the processing of the data can continue. after 365 * these are run 'm' and 'meta' should be considered 366 * as invalid and NG_SEND_DATA actually zaps them. */ 367 NG_SEND_DATA(error, xxxp->channel[chan].hook, m, meta); 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_DATA(m, meta); 374 } 375 return 0; 376} 377 378#if 0 379/* 380 * If this were a device node, the data may have been received in response 381 * to some interrupt. 382 * in which case it would probably look as follows: 383 */ 384devintr() 385{ 386 int error; 387 * here */ 388 389 /* get packet from device and send on */ 390 m = MGET(blah blah) 391 392 NG_SEND_DATA_ONLY(error, xxxp->upstream_hook.hook, m); 393 /* see note above in xxx_rcvdata() */ 394 /* and ng_xxx_connect() */ 395} 396 397#endif /* 0 */ 398 399/* 400 * Do local shutdown processing.. 401 * If we are a persistant device, we might refuse to go away, and 402 * we'd only remove our links and reset ourself. 403 */ 404static int 405ng_xxx_rmnode(node_p node) 406{ 407 const xxx_p privdata = node->private; 408 409 node->flags |= NG_INVALID; 410 ng_cutlinks(node); 411#ifndef PERSISTANT_NODE 412 ng_unname(node); 413 node->private = NULL; 414 ng_unref(privdata->node); 415 FREE(privdata, M_NETGRAPH); 416#else 417 privdata->packets_in = 0; /* reset stats */ 418 privdata->packets_out = 0; 419 node->flags &= ~NG_INVALID; /* reset invalid flag */ 420#endif /* PERSISTANT_NODE */ 421 return (0); 422} 423 424/* 425 * This is called once we've already connected a new hook to the other node. 426 * It gives us a chance to balk at the last minute. 427 */ 428static int 429ng_xxx_connect(hook_p hook) 430{ 431#if 0 432 /* 433 * If we were a driver running at other than splnet then 434 * we should set the QUEUE bit on the edge so that we 435 * will deliver by queing. 436 */ 437 if /*it is the upstream hook */ 438 hook->peer->flags |= HK_QUEUE; 439#endif 440#if 0 441 /* 442 * If for some reason we want incoming date to be queued 443 * by the NETISR system and delivered later we can set the same bit on 444 * OUR hook. (maybe to allow unwinding of the stack) 445 */ 446 447 if (hook->private) { 448 int dlci; 449 /* 450 * If it's dlci 1023, requeue it so that it's handled 451 * at a lower priority. This is how a node decides to 452 * defer a data message. 453 */ 454 dlci = ((struct XXX_hookinfo *) hook->private)->dlci; 455 if (dlci == 1023) { 456 hook->flags |= HK_QUEUE; 457 } 458#endif 459 /* otherwise be really amiable and just say "YUP that's OK by me! " */ 460 return (0); 461} 462 463/* 464 * Dook disconnection 465 * 466 * For this type, removal of the last link destroys the node 467 */ 468static int 469ng_xxx_disconnect(hook_p hook) 470{ 471 if (hook->private) 472 ((struct XXX_hookinfo *) (hook->private))->hook = NULL; 473 if (hook->node->numhooks == 0) 474 ng_rmnode(hook->node); 475 return (0); 476} 477 478