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