1 /*
2 * ng_base.c
3 *
4 * Copyright (c) 1996-1999 Whistle Communications, Inc.
5 * All rights reserved.
6 *
7 * Subject to the following obligations and disclaimer of warranty, use and
8 * redistribution of this software, in source or object code forms, with or
9 * without modifications are expressly permitted by Whistle Communications;
10 * provided, however, that:
11 * 1. Any and all reproductions of the source or object code must include the
12 * copyright notice above and the following disclaimer of warranties; and
13 * 2. No rights are granted, in any manner or form, to use Whistle
14 * Communications, Inc. trademarks, including the mark "WHISTLE
15 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as
16 * such appears in the above copyright notice or in the software.
17 *
18 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
19 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
20 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
21 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
22 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
23 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
24 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
25 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
26 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
27 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
28 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
29 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
30 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
31 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
32 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
33 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
34 * OF SUCH DAMAGE.
35 *
36 * Authors: Julian Elischer <julian@freebsd.org>
37 * Archie Cobbs <archie@freebsd.org>
38 *
39 * $FreeBSD: releng/5.1/sys/netgraph/ng_base.c 114216 2003-04-29 13:36:06Z kan $
40 * $Whistle: ng_base.c,v 1.39 1999/01/28 23:54:53 julian Exp $
41 */
42
43 /*
44 * This file implements the base netgraph code.
45 */
46
47 #include <sys/param.h>
48 #include <sys/systm.h>
49 #include <sys/errno.h>
50 #include <sys/kernel.h>
51 #include <sys/limits.h>
52 #include <sys/malloc.h>
53 #include <sys/syslog.h>
54 #include <sys/sysctl.h>
55 #include <sys/linker.h>
56 #include <sys/queue.h>
57 #include <sys/mbuf.h>
58 #include <sys/ctype.h>
59 #include <sys/sysctl.h>
60
61 #include <net/netisr.h>
62
63 #include <netgraph/ng_message.h>
64 #include <netgraph/netgraph.h>
65 #include <netgraph/ng_parse.h>
66
67 MODULE_VERSION(netgraph, NG_ABI_VERSION);
68
69 /* List of all active nodes */
70 static LIST_HEAD(, ng_node) ng_nodelist;
71 static struct mtx ng_nodelist_mtx;
72
73 #ifdef NETGRAPH_DEBUG
74
75 static SLIST_HEAD(, ng_node) ng_allnodes;
76 static LIST_HEAD(, ng_node) ng_freenodes; /* in debug, we never free() them */
77 static SLIST_HEAD(, ng_hook) ng_allhooks;
78 static LIST_HEAD(, ng_hook) ng_freehooks; /* in debug, we never free() them */
79
80 static void ng_dumpitems(void);
81 static void ng_dumpnodes(void);
82 static void ng_dumphooks(void);
83
84 #endif /* NETGRAPH_DEBUG */
85 /*
86 * DEAD versions of the structures.
87 * In order to avoid races, it is sometimes neccesary to point
88 * at SOMETHING even though theoretically, the current entity is
89 * INVALID. Use these to avoid these races.
90 */
91 struct ng_type ng_deadtype = {
92 NG_ABI_VERSION,
93 "dead",
94 NULL, /* modevent */
95 NULL, /* constructor */
96 NULL, /* rcvmsg */
97 NULL, /* shutdown */
98 NULL, /* newhook */
99 NULL, /* findhook */
100 NULL, /* connect */
101 NULL, /* rcvdata */
102 NULL, /* disconnect */
103 NULL, /* cmdlist */
104 };
105
106 struct ng_node ng_deadnode = {
107 "dead",
108 &ng_deadtype,
109 NG_INVALID,
110 1, /* refs */
111 0, /* numhooks */
112 NULL, /* private */
113 0, /* ID */
114 LIST_HEAD_INITIALIZER(ng_deadnode.hooks),
115 {}, /* all_nodes list entry */
116 {}, /* id hashtable list entry */
117 {}, /* workqueue entry */
118 { 0,
119 {}, /* should never use! (should hang) */
120 NULL,
121 &ng_deadnode.nd_input_queue.queue,
122 &ng_deadnode
123 },
124 #ifdef NETGRAPH_DEBUG
125 ND_MAGIC,
126 __FILE__,
127 __LINE__,
128 {NULL}
129 #endif /* NETGRAPH_DEBUG */
130 };
131
132 struct ng_hook ng_deadhook = {
133 "dead",
134 NULL, /* private */
135 HK_INVALID | HK_DEAD,
136 1, /* refs always >= 1 */
137 &ng_deadhook, /* Peer is self */
138 &ng_deadnode, /* attached to deadnode */
139 {}, /* hooks list */
140 NULL, /* override rcvmsg() */
141 NULL, /* override rcvdata() */
142 #ifdef NETGRAPH_DEBUG
143 HK_MAGIC,
144 __FILE__,
145 __LINE__,
146 {NULL}
147 #endif /* NETGRAPH_DEBUG */
148 };
149
150 /*
151 * END DEAD STRUCTURES
152 */
153 /* List nodes with unallocated work */
154 static TAILQ_HEAD(, ng_node) ng_worklist = TAILQ_HEAD_INITIALIZER(ng_worklist);
155 static struct mtx ng_worklist_mtx; /* MUST LOCK NODE FIRST */
156
157 /* List of installed types */
158 static LIST_HEAD(, ng_type) ng_typelist;
159 static struct mtx ng_typelist_mtx;
160
161 /* Hash related definitions */
162 /* XXX Don't need to initialise them because it's a LIST */
163 #define NG_ID_HASH_SIZE 32 /* most systems wont need even this many */
164 static LIST_HEAD(, ng_node) ng_ID_hash[NG_ID_HASH_SIZE];
165 static struct mtx ng_idhash_mtx;
166 /* Method to find a node.. used twice so do it here */
167 #define NG_IDHASH_FN(ID) ((ID) % (NG_ID_HASH_SIZE))
168 #define NG_IDHASH_FIND(ID, node) \
169 do { \
170 LIST_FOREACH(node, &ng_ID_hash[NG_IDHASH_FN(ID)], \
171 nd_idnodes) { \
172 if (NG_NODE_IS_VALID(node) \
173 && (NG_NODE_ID(node) == ID)) { \
174 break; \
175 } \
176 } \
177 } while (0)
178
179 /* Mutex that protects the free queue item list */
180 static volatile item_p ngqfree; /* free ones */
181 static struct mtx ngq_mtx;
182
183 /* Internal functions */
184 static int ng_add_hook(node_p node, const char *name, hook_p * hookp);
185 static int ng_generic_msg(node_p here, item_p item, hook_p lasthook);
186 static ng_ID_t ng_decodeidname(const char *name);
187 static int ngb_mod_event(module_t mod, int event, void *data);
188 static void ng_worklist_remove(node_p node);
189 static void ngintr(void);
190 static int ng_apply_item(node_p node, item_p item);
191 static void ng_flush_input_queue(struct ng_queue * ngq);
192 static void ng_setisr(node_p node);
193 static node_p ng_ID2noderef(ng_ID_t ID);
194 static int ng_con_nodes(node_p node, const char *name, node_p node2,
195 const char *name2);
196 static void ng_con_part2(node_p node, hook_p hook, void *arg1, int arg2);
197 static void ng_con_part3(node_p node, hook_p hook, void *arg1, int arg2);
198 static int ng_mkpeer(node_p node, const char *name,
199 const char *name2, char *type);
200
201 /* imported , these used to be externally visible, some may go back */
202 int ng_bypass(hook_p hook1, hook_p hook2);
203 void ng_destroy_hook(hook_p hook);
204 node_p ng_name2noderef(node_p node, const char *name);
205 int ng_path2noderef(node_p here, const char *path,
206 node_p *dest, hook_p *lasthook);
207 struct ng_type *ng_findtype(const char *type);
208 int ng_make_node(const char *type, node_p *nodepp);
209 int ng_path_parse(char *addr, char **node, char **path, char **hook);
210 void ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3);
211 void ng_unname(node_p node);
212
213
214 /* Our own netgraph malloc type */
215 MALLOC_DEFINE(M_NETGRAPH, "netgraph", "netgraph structures and ctrl messages");
216 MALLOC_DEFINE(M_NETGRAPH_HOOK, "netgraph_hook", "netgraph hook structures");
217 MALLOC_DEFINE(M_NETGRAPH_NODE, "netgraph_node", "netgraph node structures");
218 MALLOC_DEFINE(M_NETGRAPH_ITEM, "netgraph_item", "netgraph item structures");
219 MALLOC_DEFINE(M_NETGRAPH_META, "netgraph_meta", "netgraph name storage");
220 MALLOC_DEFINE(M_NETGRAPH_MSG, "netgraph_msg", "netgraph name storage");
221
222 /* Should not be visible outside this file */
223
224 #define _NG_ALLOC_HOOK(hook) \
225 MALLOC(hook, hook_p, sizeof(*hook), M_NETGRAPH_HOOK, M_NOWAIT | M_ZERO)
226 #define _NG_ALLOC_NODE(node) \
227 MALLOC(node, node_p, sizeof(*node), M_NETGRAPH_NODE, M_NOWAIT | M_ZERO)
228
229 #ifdef NETGRAPH_DEBUG /*----------------------------------------------*/
230 /*
231 * In debug mode:
232 * In an attempt to help track reference count screwups
233 * we do not free objects back to the malloc system, but keep them
234 * in a local cache where we can examine them and keep information safely
235 * after they have been freed.
236 * We use this scheme for nodes and hooks, and to some extent for items.
237 */
238 static __inline hook_p
239 ng_alloc_hook(void)
240 {
241 hook_p hook;
242 SLIST_ENTRY(ng_hook) temp;
243 mtx_lock(&ng_nodelist_mtx);
244 hook = LIST_FIRST(&ng_freehooks);
245 if (hook) {
246 LIST_REMOVE(hook, hk_hooks);
247 bcopy(&hook->hk_all, &temp, sizeof(temp));
248 bzero(hook, sizeof(struct ng_hook));
249 bcopy(&temp, &hook->hk_all, sizeof(temp));
250 mtx_unlock(&ng_nodelist_mtx);
251 hook->hk_magic = HK_MAGIC;
252 } else {
253 mtx_unlock(&ng_nodelist_mtx);
254 _NG_ALLOC_HOOK(hook);
255 if (hook) {
256 hook->hk_magic = HK_MAGIC;
257 mtx_lock(&ng_nodelist_mtx);
258 SLIST_INSERT_HEAD(&ng_allhooks, hook, hk_all);
259 mtx_unlock(&ng_nodelist_mtx);
260 }
261 }
262 return (hook);
263 }
264
265 static __inline node_p
266 ng_alloc_node(void)
267 {
268 node_p node;
269 SLIST_ENTRY(ng_node) temp;
270 mtx_lock(&ng_nodelist_mtx);
271 node = LIST_FIRST(&ng_freenodes);
272 if (node) {
273 LIST_REMOVE(node, nd_nodes);
274 bcopy(&node->nd_all, &temp, sizeof(temp));
275 bzero(node, sizeof(struct ng_node));
276 bcopy(&temp, &node->nd_all, sizeof(temp));
277 mtx_unlock(&ng_nodelist_mtx);
278 node->nd_magic = ND_MAGIC;
279 } else {
280 mtx_unlock(&ng_nodelist_mtx);
281 _NG_ALLOC_NODE(node);
282 if (node) {
283 node->nd_magic = ND_MAGIC;
284 mtx_lock(&ng_nodelist_mtx);
285 SLIST_INSERT_HEAD(&ng_allnodes, node, nd_all);
286 mtx_unlock(&ng_nodelist_mtx);
287 }
288 }
289 return (node);
290 }
291
292 #define NG_ALLOC_HOOK(hook) do { (hook) = ng_alloc_hook(); } while (0)
293 #define NG_ALLOC_NODE(node) do { (node) = ng_alloc_node(); } while (0)
294
295
296 #define NG_FREE_HOOK(hook) \
297 do { \
298 mtx_lock(&ng_nodelist_mtx); \
299 LIST_INSERT_HEAD(&ng_freehooks, hook, hk_hooks); \
300 hook->hk_magic = 0; \
301 mtx_unlock(&ng_nodelist_mtx); \
302 } while (0)
303
304 #define NG_FREE_NODE(node) \
305 do { \
306 mtx_lock(&ng_nodelist_mtx); \
307 LIST_INSERT_HEAD(&ng_freenodes, node, nd_nodes); \
308 node->nd_magic = 0; \
309 mtx_unlock(&ng_nodelist_mtx); \
310 } while (0)
311
312 #else /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
313
314 #define NG_ALLOC_HOOK(hook) _NG_ALLOC_HOOK(hook)
315 #define NG_ALLOC_NODE(node) _NG_ALLOC_NODE(node)
316
317 #define NG_FREE_HOOK(hook) do { FREE((hook), M_NETGRAPH_HOOK); } while (0)
318 #define NG_FREE_NODE(node) do { FREE((node), M_NETGRAPH_NODE); } while (0)
319
320 #endif /* NETGRAPH_DEBUG */ /*----------------------------------------------*/
321
322 /* Warning: Generally use NG_FREE_ITEM() instead */
323 #define NG_FREE_ITEM_REAL(item) do { FREE((item), M_NETGRAPH_ITEM); } while (0)
324
325
326 /* Set this to Debugger("X") to catch all errors as they occur */
327 #ifndef TRAP_ERROR
328 #define TRAP_ERROR()
329 #endif
330
331 static ng_ID_t nextID = 1;
332
333 #ifdef INVARIANTS
334 #define CHECK_DATA_MBUF(m) do { \
335 struct mbuf *n; \
336 int total; \
337 \
338 M_ASSERTPKTHDR(m); \
339 for (total = 0, n = (m); n != NULL; n = n->m_next) \
340 total += n->m_len; \
341 if ((m)->m_pkthdr.len != total) { \
342 panic("%s: %d != %d", \
343 __func__, (m)->m_pkthdr.len, total); \
344 } \
345 } while (0)
346 #else
347 #define CHECK_DATA_MBUF(m)
348 #endif
349
350
351 /************************************************************************
352 Parse type definitions for generic messages
353 ************************************************************************/
354
355 /* Handy structure parse type defining macro */
356 #define DEFINE_PARSE_STRUCT_TYPE(lo, up, args) \
357 static const struct ng_parse_struct_field \
358 ng_ ## lo ## _type_fields[] = NG_GENERIC_ ## up ## _INFO args; \
359 static const struct ng_parse_type ng_generic_ ## lo ## _type = { \
360 &ng_parse_struct_type, \
361 &ng_ ## lo ## _type_fields \
362 }
363
364 DEFINE_PARSE_STRUCT_TYPE(mkpeer, MKPEER, ());
365 DEFINE_PARSE_STRUCT_TYPE(connect, CONNECT, ());
366 DEFINE_PARSE_STRUCT_TYPE(name, NAME, ());
367 DEFINE_PARSE_STRUCT_TYPE(rmhook, RMHOOK, ());
368 DEFINE_PARSE_STRUCT_TYPE(nodeinfo, NODEINFO, ());
369 DEFINE_PARSE_STRUCT_TYPE(typeinfo, TYPEINFO, ());
370 DEFINE_PARSE_STRUCT_TYPE(linkinfo, LINKINFO, (&ng_generic_nodeinfo_type));
371
372 /* Get length of an array when the length is stored as a 32 bit
373 value immediately preceding the array -- as with struct namelist
374 and struct typelist. */
375 static int
376 ng_generic_list_getLength(const struct ng_parse_type *type,
377 const u_char *start, const u_char *buf)
378 {
379 return *((const u_int32_t *)(buf - 4));
380 }
381
382 /* Get length of the array of struct linkinfo inside a struct hooklist */
383 static int
384 ng_generic_linkinfo_getLength(const struct ng_parse_type *type,
385 const u_char *start, const u_char *buf)
386 {
387 const struct hooklist *hl = (const struct hooklist *)start;
388
389 return hl->nodeinfo.hooks;
390 }
391
392 /* Array type for a variable length array of struct namelist */
393 static const struct ng_parse_array_info ng_nodeinfoarray_type_info = {
394 &ng_generic_nodeinfo_type,
395 &ng_generic_list_getLength
396 };
397 static const struct ng_parse_type ng_generic_nodeinfoarray_type = {
398 &ng_parse_array_type,
399 &ng_nodeinfoarray_type_info
400 };
401
402 /* Array type for a variable length array of struct typelist */
403 static const struct ng_parse_array_info ng_typeinfoarray_type_info = {
404 &ng_generic_typeinfo_type,
405 &ng_generic_list_getLength
406 };
407 static const struct ng_parse_type ng_generic_typeinfoarray_type = {
408 &ng_parse_array_type,
409 &ng_typeinfoarray_type_info
410 };
411
412 /* Array type for array of struct linkinfo in struct hooklist */
413 static const struct ng_parse_array_info ng_generic_linkinfo_array_type_info = {
414 &ng_generic_linkinfo_type,
415 &ng_generic_linkinfo_getLength
416 };
417 static const struct ng_parse_type ng_generic_linkinfo_array_type = {
418 &ng_parse_array_type,
419 &ng_generic_linkinfo_array_type_info
420 };
421
422 DEFINE_PARSE_STRUCT_TYPE(typelist, TYPELIST, (&ng_generic_nodeinfoarray_type));
423 DEFINE_PARSE_STRUCT_TYPE(hooklist, HOOKLIST,
424 (&ng_generic_nodeinfo_type, &ng_generic_linkinfo_array_type));
425 DEFINE_PARSE_STRUCT_TYPE(listnodes, LISTNODES,
426 (&ng_generic_nodeinfoarray_type));
427
428 /* List of commands and how to convert arguments to/from ASCII */
429 static const struct ng_cmdlist ng_generic_cmds[] = {
430 {
431 NGM_GENERIC_COOKIE,
432 NGM_SHUTDOWN,
433 "shutdown",
434 NULL,
435 NULL
436 },
437 {
438 NGM_GENERIC_COOKIE,
439 NGM_MKPEER,
440 "mkpeer",
441 &ng_generic_mkpeer_type,
442 NULL
443 },
444 {
445 NGM_GENERIC_COOKIE,
446 NGM_CONNECT,
447 "connect",
448 &ng_generic_connect_type,
449 NULL
450 },
451 {
452 NGM_GENERIC_COOKIE,
453 NGM_NAME,
454 "name",
455 &ng_generic_name_type,
456 NULL
457 },
458 {
459 NGM_GENERIC_COOKIE,
460 NGM_RMHOOK,
461 "rmhook",
462 &ng_generic_rmhook_type,
463 NULL
464 },
465 {
466 NGM_GENERIC_COOKIE,
467 NGM_NODEINFO,
468 "nodeinfo",
469 NULL,
470 &ng_generic_nodeinfo_type
471 },
472 {
473 NGM_GENERIC_COOKIE,
474 NGM_LISTHOOKS,
475 "listhooks",
476 NULL,
477 &ng_generic_hooklist_type
478 },
479 {
480 NGM_GENERIC_COOKIE,
481 NGM_LISTNAMES,
482 "listnames",
483 NULL,
484 &ng_generic_listnodes_type /* same as NGM_LISTNODES */
485 },
486 {
487 NGM_GENERIC_COOKIE,
488 NGM_LISTNODES,
489 "listnodes",
490 NULL,
491 &ng_generic_listnodes_type
492 },
493 {
494 NGM_GENERIC_COOKIE,
495 NGM_LISTTYPES,
496 "listtypes",
497 NULL,
498 &ng_generic_typeinfo_type
499 },
500 {
501 NGM_GENERIC_COOKIE,
502 NGM_TEXT_CONFIG,
503 "textconfig",
504 NULL,
505 &ng_parse_string_type
506 },
507 {
508 NGM_GENERIC_COOKIE,
509 NGM_TEXT_STATUS,
510 "textstatus",
511 NULL,
512 &ng_parse_string_type
513 },
514 {
515 NGM_GENERIC_COOKIE,
516 NGM_ASCII2BINARY,
517 "ascii2binary",
518 &ng_parse_ng_mesg_type,
519 &ng_parse_ng_mesg_type
520 },
521 {
522 NGM_GENERIC_COOKIE,
523 NGM_BINARY2ASCII,
524 "binary2ascii",
525 &ng_parse_ng_mesg_type,
526 &ng_parse_ng_mesg_type
527 },
528 { 0 }
529 };
530
531 /************************************************************************
532 Node routines
533 ************************************************************************/
534
535 /*
536 * Instantiate a node of the requested type
537 */
538 int
539 ng_make_node(const char *typename, node_p *nodepp)
540 {
541 struct ng_type *type;
542 int error;
543
544 /* Check that the type makes sense */
545 if (typename == NULL) {
546 TRAP_ERROR();
547 return (EINVAL);
548 }
549
550 /* Locate the node type */
551 if ((type = ng_findtype(typename)) == NULL) {
552 char filename[NG_TYPELEN + 4];
553 linker_file_t lf;
554 int error;
555
556 /* Not found, try to load it as a loadable module */
557 snprintf(filename, sizeof(filename), "ng_%s", typename);
558 error = linker_load_module(NULL, filename, NULL, NULL, &lf);
559 if (error != 0)
560 return (error);
561 lf->userrefs++; /* pretend loaded by the syscall */
562
563 /* Try again, as now the type should have linked itself in */
564 if ((type = ng_findtype(typename)) == NULL)
565 return (ENXIO);
566 }
567
568 /*
569 * If we have a constructor, then make the node and
570 * call the constructor to do type specific initialisation.
571 */
572 if (type->constructor != NULL) {
573 if ((error = ng_make_node_common(type, nodepp)) == 0) {
574 if ((error = ((*type->constructor)(*nodepp)) != 0)) {
575 NG_NODE_UNREF(*nodepp);
576 }
577 }
578 } else {
579 /*
580 * Node has no constructor. We cannot ask for one
581 * to be made. It must be brought into existance by
582 * some external agency. The external agency should
583 * call ng_make_node_common() directly to get the
584 * netgraph part initialised.
585 */
586 TRAP_ERROR();
587 error = EINVAL;
588 }
589 return (error);
590 }
591
592 /*
593 * Generic node creation. Called by node initialisation for externally
594 * instantiated nodes (e.g. hardware, sockets, etc ).
595 * The returned node has a reference count of 1.
596 */
597 int
598 ng_make_node_common(struct ng_type *type, node_p *nodepp)
599 {
600 node_p node;
601
602 /* Require the node type to have been already installed */
603 if (ng_findtype(type->name) == NULL) {
604 TRAP_ERROR();
605 return (EINVAL);
606 }
607
608 /* Make a node and try attach it to the type */
609 NG_ALLOC_NODE(node);
610 if (node == NULL) {
611 TRAP_ERROR();
612 return (ENOMEM);
613 }
614 node->nd_type = type;
615 NG_NODE_REF(node); /* note reference */
616 type->refs++;
617
618 mtx_init(&node->nd_input_queue.q_mtx, "ng_node", NULL, MTX_SPIN);
619 node->nd_input_queue.queue = NULL;
620 node->nd_input_queue.last = &node->nd_input_queue.queue;
621 node->nd_input_queue.q_flags = 0;
622 node->nd_input_queue.q_node = node;
623
624 /* Initialize hook list for new node */
625 LIST_INIT(&node->nd_hooks);
626
627 /* Link us into the node linked list */
628 mtx_lock(&ng_nodelist_mtx);
629 LIST_INSERT_HEAD(&ng_nodelist, node, nd_nodes);
630 mtx_unlock(&ng_nodelist_mtx);
631
632
633 /* get an ID and put us in the hash chain */
634 mtx_lock(&ng_idhash_mtx);
635 for (;;) { /* wrap protection, even if silly */
636 node_p node2 = NULL;
637 node->nd_ID = nextID++; /* 137/second for 1 year before wrap */
638
639 /* Is there a problem with the new number? */
640 NG_IDHASH_FIND(node->nd_ID, node2); /* already taken? */
641 if ((node->nd_ID != 0) && (node2 == NULL)) {
642 break;
643 }
644 }
645 LIST_INSERT_HEAD(&ng_ID_hash[NG_IDHASH_FN(node->nd_ID)],
646 node, nd_idnodes);
647 mtx_unlock(&ng_idhash_mtx);
648
649 /* Done */
650 *nodepp = node;
651 return (0);
652 }
653
654 /*
655 * Forceably start the shutdown process on a node. Either call
656 * it's shutdown method, or do the default shutdown if there is
657 * no type-specific method.
658 *
659 * We can only be called form a shutdown message, so we know we have
660 * a writer lock, and therefore exclusive access. It also means
661 * that we should not be on the work queue, but we check anyhow.
662 *
663 * Persistent node types must have a type-specific method which
664 * Allocates a new node in which case, this one is irretrievably going away,
665 * or cleans up anything it needs, and just makes the node valid again,
666 * in which case we allow the node to survive.
667 *
668 * XXX We need to think of how to tell a persistant node that we
669 * REALLY need to go away because the hardware has gone or we
670 * are rebooting.... etc.
671 */
672 void
673 ng_rmnode(node_p node, hook_p dummy1, void *dummy2, int dummy3)
674 {
675 hook_p hook;
676
677 /* Check if it's already shutting down */
678 if ((node->nd_flags & NG_CLOSING) != 0)
679 return;
680
681 if (node == &ng_deadnode) {
682 printf ("shutdown called on deadnode\n");
683 return;
684 }
685
686 /* Add an extra reference so it doesn't go away during this */
687 NG_NODE_REF(node);
688
689 /*
690 * Mark it invalid so any newcomers know not to try use it
691 * Also add our own mark so we can't recurse
692 * note that NG_INVALID does not do this as it's also set during
693 * creation
694 */
695 node->nd_flags |= NG_INVALID|NG_CLOSING;
696
697 /* Notify all remaining connected nodes to disconnect */
698 while ((hook = LIST_FIRST(&node->nd_hooks)) != NULL)
699 ng_destroy_hook(hook);
700
701 /*
702 * Drain the input queue forceably.
703 * it has no hooks so what's it going to do, bleed on someone?
704 * Theoretically we came here from a queue entry that was added
705 * Just before the queue was closed, so it should be empty anyway.
706 * Also removes us from worklist if needed.
707 */
708 ng_flush_input_queue(&node->nd_input_queue);
709
710 /* Ask the type if it has anything to do in this case */
711 if (node->nd_type && node->nd_type->shutdown) {
712 (*node->nd_type->shutdown)(node);
713 if (NG_NODE_IS_VALID(node)) {
714 /*
715 * Well, blow me down if the node code hasn't declared
716 * that it doesn't want to die.
717 * Presumably it is a persistant node.
718 * If we REALLY want it to go away,
719 * e.g. hardware going away,
720 * Our caller should set NG_REALLY_DIE in nd_flags.
721 */
722 node->nd_flags &= ~(NG_INVALID|NG_CLOSING);
723 NG_NODE_UNREF(node); /* Assume they still have theirs */
724 return;
725 }
726 } else { /* do the default thing */
727 NG_NODE_UNREF(node);
728 }
729
730 ng_unname(node); /* basically a NOP these days */
731
732 /*
733 * Remove extra reference, possibly the last
734 * Possible other holders of references may include
735 * timeout callouts, but theoretically the node's supposed to
736 * have cancelled them. Possibly hardware dependencies may
737 * force a driver to 'linger' with a reference.
738 */
739 NG_NODE_UNREF(node);
740 }
741
742 #ifdef NETGRAPH_DEBUG
743 void
744 ng_ref_node(node_p node)
745 {
746 _NG_NODE_REF(node);
747 }
748 #endif
749
750 /*
751 * Remove a reference to the node, possibly the last.
752 * deadnode always acts as it it were the last.
753 */
754 int
755 ng_unref_node(node_p node)
756 {
757 int v;
758
759 if (node == &ng_deadnode) {
760 return (0);
761 }
762
763 do {
764 v = node->nd_refs - 1;
765 } while (! atomic_cmpset_int(&node->nd_refs, v + 1, v));
766
767 if (v == 0) { /* we were the last */
768
769 mtx_lock(&ng_nodelist_mtx);
770 node->nd_type->refs--; /* XXX maybe should get types lock? */
771 LIST_REMOVE(node, nd_nodes);
772 mtx_unlock(&ng_nodelist_mtx);
773
774 mtx_lock(&ng_idhash_mtx);
775 LIST_REMOVE(node, nd_idnodes);
776 mtx_unlock(&ng_idhash_mtx);
777
778 mtx_destroy(&node->nd_input_queue.q_mtx);
779 NG_FREE_NODE(node);
780 }
781 return (v);
782 }
783
784 /************************************************************************
785 Node ID handling
786 ************************************************************************/
787 static node_p
788 ng_ID2noderef(ng_ID_t ID)
789 {
790 node_p node;
791 mtx_lock(&ng_idhash_mtx);
792 NG_IDHASH_FIND(ID, node);
793 if(node)
794 NG_NODE_REF(node);
795 mtx_unlock(&ng_idhash_mtx);
796 return(node);
797 }
798
799 ng_ID_t
800 ng_node2ID(node_p node)
801 {
802 return (node ? NG_NODE_ID(node) : 0);
803 }
804
805 /************************************************************************
806 Node name handling
807 ************************************************************************/
808
809 /*
810 * Assign a node a name. Once assigned, the name cannot be changed.
811 */
812 int
813 ng_name_node(node_p node, const char *name)
814 {
815 int i;
816 node_p node2;
817
818 /* Check the name is valid */
819 for (i = 0; i < NG_NODELEN + 1; i++) {
820 if (name[i] == '\0' || name[i] == '.' || name[i] == ':')
821 break;
822 }
823 if (i == 0 || name[i] != '\0') {
824 TRAP_ERROR();
825 return (EINVAL);
826 }
827 if (ng_decodeidname(name) != 0) { /* valid IDs not allowed here */
828 TRAP_ERROR();
829 return (EINVAL);
830 }
831
832 /* Check the name isn't already being used */
833 if ((node2 = ng_name2noderef(node, name)) != NULL) {
834 NG_NODE_UNREF(node2);
835 TRAP_ERROR();
836 return (EADDRINUSE);
837 }
838
839 /* copy it */
840 strncpy(NG_NODE_NAME(node), name, NG_NODELEN);
841
842 return (0);
843 }
844
845 /*
846 * Find a node by absolute name. The name should NOT end with ':'
847 * The name "." means "this node" and "[xxx]" means "the node
848 * with ID (ie, at address) xxx".
849 *
850 * Returns the node if found, else NULL.
851 * Eventually should add something faster than a sequential search.
852 * Note it aquires a reference on the node so you can be sure it's still there.
853 */
854 node_p
855 ng_name2noderef(node_p here, const char *name)
856 {
857 node_p node;
858 ng_ID_t temp;
859
860 /* "." means "this node" */
861 if (strcmp(name, ".") == 0) {
862 NG_NODE_REF(here);
863 return(here);
864 }
865
866 /* Check for name-by-ID */
867 if ((temp = ng_decodeidname(name)) != 0) {
868 return (ng_ID2noderef(temp));
869 }
870
871 /* Find node by name */
872 mtx_lock(&ng_nodelist_mtx);
873 LIST_FOREACH(node, &ng_nodelist, nd_nodes) {
874 if (NG_NODE_IS_VALID(node)
875 && NG_NODE_HAS_NAME(node)
876 && (strcmp(NG_NODE_NAME(node), name) == 0)) {
877 break;
878 }
879 }
880 if (node)
881 NG_NODE_REF(node);
882 mtx_unlock(&ng_nodelist_mtx);
883 return (node);
884 }
885
886 /*
887 * Decode an ID name, eg. "[f03034de]". Returns 0 if the
888 * string is not valid, otherwise returns the value.
889 */
890 static ng_ID_t
891 ng_decodeidname(const char *name)
892 {
893 const int len = strlen(name);
894 char *eptr;
895 u_long val;
896
897 /* Check for proper length, brackets, no leading junk */
898 if ((len < 3)
899 || (name[0] != '[')
900 || (name[len - 1] != ']')
901 || (!isxdigit(name[1]))) {
902 return ((ng_ID_t)0);
903 }
904
905 /* Decode number */
906 val = strtoul(name + 1, &eptr, 16);
907 if ((eptr - name != len - 1)
908 || (val == ULONG_MAX)
909 || (val == 0)) {
910 return ((ng_ID_t)0);
911 }
912 return (ng_ID_t)val;
913 }
914
915 /*
916 * Remove a name from a node. This should only be called
917 * when shutting down and removing the node.
918 * IF we allow name changing this may be more resurected.
919 */
920 void
921 ng_unname(node_p node)
922 {
923 }
924
925 /************************************************************************
926 Hook routines
927 Names are not optional. Hooks are always connected, except for a
928 brief moment within these routines. On invalidation or during creation
929 they are connected to the 'dead' hook.
930 ************************************************************************/
931
932 /*
933 * Remove a hook reference
934 */
935 void
936 ng_unref_hook(hook_p hook)
937 {
938 int v;
939
940 if (hook == &ng_deadhook) {
941 return;
942 }
943 do {
944 v = hook->hk_refs;
945 } while (! atomic_cmpset_int(&hook->hk_refs, v, v - 1));
946
947 if (v == 1) { /* we were the last */
948 if (_NG_HOOK_NODE(hook)) { /* it'll probably be ng_deadnode */
949 _NG_NODE_UNREF((_NG_HOOK_NODE(hook)));
950 hook->hk_node = NULL;
951 }
952 NG_FREE_HOOK(hook);
953 }
954 }
955
956 /*
957 * Add an unconnected hook to a node. Only used internally.
958 * Assumes node is locked. (XXX not yet true )
959 */
960 static int
961 ng_add_hook(node_p node, const char *name, hook_p *hookp)
962 {
963 hook_p hook;
964 int error = 0;
965
966 /* Check that the given name is good */
967 if (name == NULL) {
968 TRAP_ERROR();
969 return (EINVAL);
970 }
971 if (ng_findhook(node, name) != NULL) {
972 TRAP_ERROR();
973 return (EEXIST);
974 }
975
976 /* Allocate the hook and link it up */
977 NG_ALLOC_HOOK(hook);
978 if (hook == NULL) {
979 TRAP_ERROR();
980 return (ENOMEM);
981 }
982 hook->hk_refs = 1; /* add a reference for us to return */
983 hook->hk_flags = HK_INVALID;
984 hook->hk_peer = &ng_deadhook; /* start off this way */
985 hook->hk_node = node;
986 NG_NODE_REF(node); /* each hook counts as a reference */
987
988 /* Set hook name */
989 strncpy(NG_HOOK_NAME(hook), name, NG_HOOKLEN);
990
991 /*
992 * Check if the node type code has something to say about it
993 * If it fails, the unref of the hook will also unref the node.
994 */
995 if (node->nd_type->newhook != NULL) {
996 if ((error = (*node->nd_type->newhook)(node, hook, name))) {
997 NG_HOOK_UNREF(hook); /* this frees the hook */
998 return (error);
999 }
1000 }
1001 /*
1002 * The 'type' agrees so far, so go ahead and link it in.
1003 * We'll ask again later when we actually connect the hooks.
1004 */
1005 LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
1006 node->nd_numhooks++;
1007 NG_HOOK_REF(hook); /* one for the node */
1008
1009 if (hookp)
1010 *hookp = hook;
1011 return (0);
1012 }
1013
1014 /*
1015 * Find a hook
1016 *
1017 * Node types may supply their own optimized routines for finding
1018 * hooks. If none is supplied, we just do a linear search.
1019 * XXX Possibly we should add a reference to the hook?
1020 */
1021 hook_p
1022 ng_findhook(node_p node, const char *name)
1023 {
1024 hook_p hook;
1025
1026 if (node->nd_type->findhook != NULL)
1027 return (*node->nd_type->findhook)(node, name);
1028 LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
1029 if (NG_HOOK_IS_VALID(hook)
1030 && (strcmp(NG_HOOK_NAME(hook), name) == 0))
1031 return (hook);
1032 }
1033 return (NULL);
1034 }
1035
1036 /*
1037 * Destroy a hook
1038 *
1039 * As hooks are always attached, this really destroys two hooks.
1040 * The one given, and the one attached to it. Disconnect the hooks
1041 * from each other first. We reconnect the peer hook to the 'dead'
1042 * hook so that it can still exist after we depart. We then
1043 * send the peer its own destroy message. This ensures that we only
1044 * interact with the peer's structures when it is locked processing that
1045 * message. We hold a reference to the peer hook so we are guaranteed that
1046 * the peer hook and node are still going to exist until
1047 * we are finished there as the hook holds a ref on the node.
1048 * We run this same code again on the peer hook, but that time it is already
1049 * attached to the 'dead' hook.
1050 *
1051 * This routine is called at all stages of hook creation
1052 * on error detection and must be able to handle any such stage.
1053 */
1054 void
1055 ng_destroy_hook(hook_p hook)
1056 {
1057 hook_p peer = NG_HOOK_PEER(hook);
1058 node_p node = NG_HOOK_NODE(hook);
1059
1060 if (hook == &ng_deadhook) { /* better safe than sorry */
1061 printf("ng_destroy_hook called on deadhook\n");
1062 return;
1063 }
1064 hook->hk_flags |= HK_INVALID; /* as soon as possible */
1065 if (peer && (peer != &ng_deadhook)) {
1066 /*
1067 * Set the peer to point to ng_deadhook
1068 * from this moment on we are effectively independent it.
1069 * send it an rmhook message of it's own.
1070 */
1071 peer->hk_peer = &ng_deadhook; /* They no longer know us */
1072 hook->hk_peer = &ng_deadhook; /* Nor us, them */
1073 if (NG_HOOK_NODE(peer) == &ng_deadnode) {
1074 /*
1075 * If it's already divorced from a node,
1076 * just free it.
1077 */
1078 /* nothing */
1079 } else {
1080 ng_rmhook_self(peer); /* Send it a surprise */
1081 }
1082 NG_HOOK_UNREF(peer); /* account for peer link */
1083 NG_HOOK_UNREF(hook); /* account for peer link */
1084 }
1085
1086 /*
1087 * Remove the hook from the node's list to avoid possible recursion
1088 * in case the disconnection results in node shutdown.
1089 */
1090 if (node == &ng_deadnode) { /* happens if called from ng_con_nodes() */
1091 return;
1092 }
1093 LIST_REMOVE(hook, hk_hooks);
1094 node->nd_numhooks--;
1095 if (node->nd_type->disconnect) {
1096 /*
1097 * The type handler may elect to destroy the node so don't
1098 * trust its existance after this point. (except
1099 * that we still hold a reference on it. (which we
1100 * inherrited from the hook we are destroying)
1101 */
1102 (*node->nd_type->disconnect) (hook);
1103 }
1104
1105 /*
1106 * Note that because we will point to ng_deadnode, the original node
1107 * is not decremented automatically so we do that manually.
1108 */
1109 _NG_HOOK_NODE(hook) = &ng_deadnode;
1110 NG_NODE_UNREF(node); /* We no longer point to it so adjust count */
1111 NG_HOOK_UNREF(hook); /* Account for linkage (in list) to node */
1112 }
1113
1114 /*
1115 * Take two hooks on a node and merge the connection so that the given node
1116 * is effectively bypassed.
1117 */
1118 int
1119 ng_bypass(hook_p hook1, hook_p hook2)
1120 {
1121 if (hook1->hk_node != hook2->hk_node) {
1122 TRAP_ERROR();
1123 return (EINVAL);
1124 }
1125 hook1->hk_peer->hk_peer = hook2->hk_peer;
1126 hook2->hk_peer->hk_peer = hook1->hk_peer;
1127
1128 hook1->hk_peer = &ng_deadhook;
1129 hook2->hk_peer = &ng_deadhook;
1130
1131 /* XXX If we ever cache methods on hooks update them as well */
1132 ng_destroy_hook(hook1);
1133 ng_destroy_hook(hook2);
1134 return (0);
1135 }
1136
1137 /*
1138 * Install a new netgraph type
1139 */
1140 int
1141 ng_newtype(struct ng_type *tp)
1142 {
1143 const size_t namelen = strlen(tp->name);
1144
1145 /* Check version and type name fields */
1146 if ((tp->version != NG_ABI_VERSION)
1147 || (namelen == 0)
1148 || (namelen > NG_TYPELEN)) {
1149 TRAP_ERROR();
1150 return (EINVAL);
1151 }
1152
1153 /* Check for name collision */
1154 if (ng_findtype(tp->name) != NULL) {
1155 TRAP_ERROR();
1156 return (EEXIST);
1157 }
1158
1159
1160 /* Link in new type */
1161 mtx_lock(&ng_typelist_mtx);
1162 LIST_INSERT_HEAD(&ng_typelist, tp, types);
1163 tp->refs = 1; /* first ref is linked list */
1164 mtx_unlock(&ng_typelist_mtx);
1165 return (0);
1166 }
1167
1168 /*
1169 * unlink a netgraph type
1170 * If no examples exist
1171 */
1172 int
1173 ng_rmtype(struct ng_type *tp)
1174 {
1175 /* Check for name collision */
1176 if (tp->refs != 1) {
1177 TRAP_ERROR();
1178 return (EBUSY);
1179 }
1180
1181 /* Unlink type */
1182 mtx_lock(&ng_typelist_mtx);
1183 LIST_REMOVE(tp, types);
1184 mtx_unlock(&ng_typelist_mtx);
1185 return (0);
1186 }
1187
1188 /*
1189 * Look for a type of the name given
1190 */
1191 struct ng_type *
1192 ng_findtype(const char *typename)
1193 {
1194 struct ng_type *type;
1195
1196 mtx_lock(&ng_typelist_mtx);
1197 LIST_FOREACH(type, &ng_typelist, types) {
1198 if (strcmp(type->name, typename) == 0)
1199 break;
1200 }
1201 mtx_unlock(&ng_typelist_mtx);
1202 return (type);
1203 }
1204
1205 /************************************************************************
1206 Composite routines
1207 ************************************************************************/
1208 /*
1209 * Connect two nodes using the specified hooks, using queued functions.
1210 */
1211 static void
1212 ng_con_part3(node_p node, hook_p hook, void *arg1, int arg2)
1213 {
1214
1215 /*
1216 * When we run, we know that the node 'node' is locked for us.
1217 * Our caller has a reference on the hook.
1218 * Our caller has a reference on the node.
1219 * (In this case our caller is ng_apply_item() ).
1220 * The peer hook has a reference on the hook.
1221 * We are all set up except for the final call to the node, and
1222 * the clearing of the INVALID flag.
1223 */
1224 if (NG_HOOK_NODE(hook) == &ng_deadnode) {
1225 /*
1226 * The node must have been freed again since we last visited
1227 * here. ng_destry_hook() has this effect but nothing else does.
1228 * We should just release our references and
1229 * free anything we can think of.
1230 * Since we know it's been destroyed, and it's our caller
1231 * that holds the references, just return.
1232 */
1233 return ;
1234 }
1235 if (hook->hk_node->nd_type->connect) {
1236 if ((*hook->hk_node->nd_type->connect) (hook)) {
1237 ng_destroy_hook(hook); /* also zaps peer */
1238 printf("failed in ng_con_part3()\n");
1239 return ;
1240 }
1241 }
1242 /*
1243 * XXX this is wrong for SMP. Possibly we need
1244 * to separate out 'create' and 'invalid' flags.
1245 * should only set flags on hooks we have locked under our node.
1246 */
1247 hook->hk_flags &= ~HK_INVALID;
1248 return ;
1249 }
1250
1251 static void
1252 ng_con_part2(node_p node, hook_p hook, void *arg1, int arg2)
1253 {
1254
1255 /*
1256 * When we run, we know that the node 'node' is locked for us.
1257 * Our caller has a reference on the hook.
1258 * Our caller has a reference on the node.
1259 * (In this case our caller is ng_apply_item() ).
1260 * The peer hook has a reference on the hook.
1261 * our node pointer points to the 'dead' node.
1262 * First check the hook name is unique.
1263 * Should not happen because we checked before queueing this.
1264 */
1265 if (ng_findhook(node, NG_HOOK_NAME(hook)) != NULL) {
1266 TRAP_ERROR();
1267 ng_destroy_hook(hook); /* should destroy peer too */
1268 printf("failed in ng_con_part2()\n");
1269 return ;
1270 }
1271 /*
1272 * Check if the node type code has something to say about it
1273 * If it fails, the unref of the hook will also unref the attached node,
1274 * however since that node is 'ng_deadnode' this will do nothing.
1275 * The peer hook will also be destroyed.
1276 */
1277 if (node->nd_type->newhook != NULL) {
1278 if ((*node->nd_type->newhook)(node, hook, hook->hk_name)) {
1279 ng_destroy_hook(hook); /* should destroy peer too */
1280 printf("failed in ng_con_part2()\n");
1281 return ;
1282 }
1283 }
1284
1285 /*
1286 * The 'type' agrees so far, so go ahead and link it in.
1287 * We'll ask again later when we actually connect the hooks.
1288 */
1289 hook->hk_node = node; /* just overwrite ng_deadnode */
1290 NG_NODE_REF(node); /* each hook counts as a reference */
1291 LIST_INSERT_HEAD(&node->nd_hooks, hook, hk_hooks);
1292 node->nd_numhooks++;
1293 NG_HOOK_REF(hook); /* one for the node */
1294
1295 /*
1296 * We now have a symetrical situation, where both hooks have been
1297 * linked to their nodes, the newhook methods have been called
1298 * And the references are all correct. The hooks are still marked
1299 * as invalid, as we have not called the 'connect' methods
1300 * yet.
1301 * We can call the local one immediatly as we have the
1302 * node locked, but we need to queue the remote one.
1303 */
1304 if (hook->hk_node->nd_type->connect) {
1305 if ((*hook->hk_node->nd_type->connect) (hook)) {
1306 ng_destroy_hook(hook); /* also zaps peer */
1307 printf("failed in ng_con_part2(A)\n");
1308 return ;
1309 }
1310 }
1311 if (ng_send_fn(hook->hk_peer->hk_node, hook->hk_peer,
1312 &ng_con_part3, arg1, arg2)) {
1313 printf("failed in ng_con_part2(B)");
1314 ng_destroy_hook(hook); /* also zaps peer */
1315 return ;
1316 }
1317 hook->hk_flags &= ~HK_INVALID; /* need both to be able to work */
1318 return ;
1319 }
1320
1321 /*
1322 * Connect this node with another node. We assume that this node is
1323 * currently locked, as we are only called from an NGM_CONNECT message.
1324 */
1325 static int
1326 ng_con_nodes(node_p node, const char *name, node_p node2, const char *name2)
1327 {
1328 int error;
1329 hook_p hook;
1330 hook_p hook2;
1331
1332 if (ng_findhook(node2, name2) != NULL) {
1333 return(EEXIST);
1334 }
1335 if ((error = ng_add_hook(node, name, &hook))) /* gives us a ref */
1336 return (error);
1337 /* Allocate the other hook and link it up */
1338 NG_ALLOC_HOOK(hook2);
1339 if (hook == NULL) {
1340 TRAP_ERROR();
1341 ng_destroy_hook(hook); /* XXX check ref counts so far */
1342 NG_HOOK_UNREF(hook); /* including our ref */
1343 return (ENOMEM);
1344 }
1345 hook2->hk_refs = 1; /* start with a reference for us. */
1346 hook2->hk_flags = HK_INVALID;
1347 hook2->hk_peer = hook; /* Link the two together */
1348 hook->hk_peer = hook2;
1349 NG_HOOK_REF(hook); /* Add a ref for the peer to each*/
1350 NG_HOOK_REF(hook2);
1351 hook2->hk_node = &ng_deadnode;
1352 strncpy(NG_HOOK_NAME(hook2), name2, NG_HOOKLEN);
1353
1354 /*
1355 * Queue the function above.
1356 * Procesing continues in that function in the lock context of
1357 * the other node.
1358 */
1359 ng_send_fn(node2, hook2, &ng_con_part2, NULL, 0);
1360
1361 NG_HOOK_UNREF(hook); /* Let each hook go if it wants to */
1362 NG_HOOK_UNREF(hook2);
1363 return (0);
1364 }
1365
1366 /*
1367 * Make a peer and connect.
1368 * We assume that the local node is locked.
1369 * The new node probably doesn't need a lock until
1370 * it has a hook, because it cannot really have any work until then,
1371 * but we should think about it a bit more.
1372 *
1373 * The problem may come if the other node also fires up
1374 * some hardware or a timer or some other source of activation,
1375 * also it may already get a command msg via it's ID.
1376 *
1377 * We could use the same method as ng_con_nodes() but we'd have
1378 * to add ability to remove the node when failing. (Not hard, just
1379 * make arg1 point to the node to remove).
1380 * Unless of course we just ignore failure to connect and leave
1381 * an unconnected node?
1382 */
1383 static int
1384 ng_mkpeer(node_p node, const char *name, const char *name2, char *type)
1385 {
1386 node_p node2;
1387 hook_p hook1;
1388 hook_p hook2;
1389 int error;
1390
1391 if ((error = ng_make_node(type, &node2))) {
1392 return (error);
1393 }
1394
1395 if ((error = ng_add_hook(node, name, &hook1))) { /* gives us a ref */
1396 ng_rmnode(node2, NULL, NULL, 0);
1397 return (error);
1398 }
1399
1400 if ((error = ng_add_hook(node2, name2, &hook2))) {
1401 ng_rmnode(node2, NULL, NULL, 0);
1402 ng_destroy_hook(hook1);
1403 NG_HOOK_UNREF(hook1);
1404 return (error);
1405 }
1406
1407 /*
1408 * Actually link the two hooks together.
1409 */
1410 hook1->hk_peer = hook2;
1411 hook2->hk_peer = hook1;
1412
1413 /* Each hook is referenced by the other */
1414 NG_HOOK_REF(hook1);
1415 NG_HOOK_REF(hook2);
1416
1417 /* Give each node the opportunity to veto the pending connection */
1418 if (hook1->hk_node->nd_type->connect) {
1419 error = (*hook1->hk_node->nd_type->connect) (hook1);
1420 }
1421
1422 if ((error == 0) && hook2->hk_node->nd_type->connect) {
1423 error = (*hook2->hk_node->nd_type->connect) (hook2);
1424
1425 }
1426
1427 /*
1428 * drop the references we were holding on the two hooks.
1429 */
1430 if (error) {
1431 ng_destroy_hook(hook2); /* also zaps hook1 */
1432 ng_rmnode(node2, NULL, NULL, 0);
1433 } else {
1434 /* As a last act, allow the hooks to be used */
1435 hook1->hk_flags &= ~HK_INVALID;
1436 hook2->hk_flags &= ~HK_INVALID;
1437 }
1438 NG_HOOK_UNREF(hook1);
1439 NG_HOOK_UNREF(hook2);
1440 return (error);
1441 }
1442
1443 /************************************************************************
1444 Utility routines to send self messages
1445 ************************************************************************/
1446
1447 /* Shut this node down as soon as everyone is clear of it */
1448 /* Should add arg "immediatly" to jump the queue */
1449 int
1450 ng_rmnode_self(node_p node)
1451 {
1452 int error;
1453
1454 if (node == &ng_deadnode)
1455 return (0);
1456 node->nd_flags |= NG_INVALID;
1457 if (node->nd_flags & NG_CLOSING)
1458 return (0);
1459
1460 error = ng_send_fn(node, NULL, &ng_rmnode, NULL, 0);
1461 return (error);
1462 }
1463
1464 static void
1465 ng_rmhook_part2(node_p node, hook_p hook, void *arg1, int arg2)
1466 {
1467 ng_destroy_hook(hook);
1468 return ;
1469 }
1470
1471 int
1472 ng_rmhook_self(hook_p hook)
1473 {
1474 int error;
1475 node_p node = NG_HOOK_NODE(hook);
1476
1477 if (node == &ng_deadnode)
1478 return (0);
1479
1480 error = ng_send_fn(node, hook, &ng_rmhook_part2, NULL, 0);
1481 return (error);
1482 }
1483
1484 /***********************************************************************
1485 * Parse and verify a string of the form: <NODE:><PATH>
1486 *
1487 * Such a string can refer to a specific node or a specific hook
1488 * on a specific node, depending on how you look at it. In the
1489 * latter case, the PATH component must not end in a dot.
1490 *
1491 * Both <NODE:> and <PATH> are optional. The <PATH> is a string
1492 * of hook names separated by dots. This breaks out the original
1493 * string, setting *nodep to "NODE" (or NULL if none) and *pathp
1494 * to "PATH" (or NULL if degenerate). Also, *hookp will point to
1495 * the final hook component of <PATH>, if any, otherwise NULL.
1496 *
1497 * This returns -1 if the path is malformed. The char ** are optional.
1498 ***********************************************************************/
1499 int
1500 ng_path_parse(char *addr, char **nodep, char **pathp, char **hookp)
1501 {
1502 char *node, *path, *hook;
1503 int k;
1504
1505 /*
1506 * Extract absolute NODE, if any
1507 */
1508 for (path = addr; *path && *path != ':'; path++);
1509 if (*path) {
1510 node = addr; /* Here's the NODE */
1511 *path++ = '\0'; /* Here's the PATH */
1512
1513 /* Node name must not be empty */
1514 if (!*node)
1515 return -1;
1516
1517 /* A name of "." is OK; otherwise '.' not allowed */
1518 if (strcmp(node, ".") != 0) {
1519 for (k = 0; node[k]; k++)
1520 if (node[k] == '.')
1521 return -1;
1522 }
1523 } else {
1524 node = NULL; /* No absolute NODE */
1525 path = addr; /* Here's the PATH */
1526 }
1527
1528 /* Snoop for illegal characters in PATH */
1529 for (k = 0; path[k]; k++)
1530 if (path[k] == ':')
1531 return -1;
1532
1533 /* Check for no repeated dots in PATH */
1534 for (k = 0; path[k]; k++)
1535 if (path[k] == '.' && path[k + 1] == '.')
1536 return -1;
1537
1538 /* Remove extra (degenerate) dots from beginning or end of PATH */
1539 if (path[0] == '.')
1540 path++;
1541 if (*path && path[strlen(path) - 1] == '.')
1542 path[strlen(path) - 1] = 0;
1543
1544 /* If PATH has a dot, then we're not talking about a hook */
1545 if (*path) {
1546 for (hook = path, k = 0; path[k]; k++)
1547 if (path[k] == '.') {
1548 hook = NULL;
1549 break;
1550 }
1551 } else
1552 path = hook = NULL;
1553
1554 /* Done */
1555 if (nodep)
1556 *nodep = node;
1557 if (pathp)
1558 *pathp = path;
1559 if (hookp)
1560 *hookp = hook;
1561 return (0);
1562 }
1563
1564 /*
1565 * Given a path, which may be absolute or relative, and a starting node,
1566 * return the destination node.
1567 */
1568 int
1569 ng_path2noderef(node_p here, const char *address,
1570 node_p *destp, hook_p *lasthook)
1571 {
1572 char fullpath[NG_PATHLEN + 1];
1573 char *nodename, *path, pbuf[2];
1574 node_p node, oldnode;
1575 char *cp;
1576 hook_p hook = NULL;
1577
1578 /* Initialize */
1579 if (destp == NULL) {
1580 TRAP_ERROR();
1581 return EINVAL;
1582 }
1583 *destp = NULL;
1584
1585 /* Make a writable copy of address for ng_path_parse() */
1586 strncpy(fullpath, address, sizeof(fullpath) - 1);
1587 fullpath[sizeof(fullpath) - 1] = '\0';
1588
1589 /* Parse out node and sequence of hooks */
1590 if (ng_path_parse(fullpath, &nodename, &path, NULL) < 0) {
1591 TRAP_ERROR();
1592 return EINVAL;
1593 }
1594 if (path == NULL) {
1595 pbuf[0] = '.'; /* Needs to be writable */
1596 pbuf[1] = '\0';
1597 path = pbuf;
1598 }
1599
1600 /*
1601 * For an absolute address, jump to the starting node.
1602 * Note that this holds a reference on the node for us.
1603 * Don't forget to drop the reference if we don't need it.
1604 */
1605 if (nodename) {
1606 node = ng_name2noderef(here, nodename);
1607 if (node == NULL) {
1608 TRAP_ERROR();
1609 return (ENOENT);
1610 }
1611 } else {
1612 if (here == NULL) {
1613 TRAP_ERROR();
1614 return (EINVAL);
1615 }
1616 node = here;
1617 NG_NODE_REF(node);
1618 }
1619
1620 /*
1621 * Now follow the sequence of hooks
1622 * XXX
1623 * We actually cannot guarantee that the sequence
1624 * is not being demolished as we crawl along it
1625 * without extra-ordinary locking etc.
1626 * So this is a bit dodgy to say the least.
1627 * We can probably hold up some things by holding
1628 * the nodelist mutex for the time of this
1629 * crawl if we wanted.. At least that way we wouldn't have to
1630 * worry about the nodes dissappearing, but the hooks would still
1631 * be a problem.
1632 */
1633 for (cp = path; node != NULL && *cp != '\0'; ) {
1634 char *segment;
1635
1636 /*
1637 * Break out the next path segment. Replace the dot we just
1638 * found with a NUL; "cp" points to the next segment (or the
1639 * NUL at the end).
1640 */
1641 for (segment = cp; *cp != '\0'; cp++) {
1642 if (*cp == '.') {
1643 *cp++ = '\0';
1644 break;
1645 }
1646 }
1647
1648 /* Empty segment */
1649 if (*segment == '\0')
1650 continue;
1651
1652 /* We have a segment, so look for a hook by that name */
1653 hook = ng_findhook(node, segment);
1654
1655 /* Can't get there from here... */
1656 if (hook == NULL
1657 || NG_HOOK_PEER(hook) == NULL
1658 || NG_HOOK_NOT_VALID(hook)
1659 || NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook))) {
1660 TRAP_ERROR();
1661 NG_NODE_UNREF(node);
1662 #if 0
1663 printf("hooknotvalid %s %s %d %d %d %d ",
1664 path,
1665 segment,
1666 hook == NULL,
1667 NG_HOOK_PEER(hook) == NULL,
1668 NG_HOOK_NOT_VALID(hook),
1669 NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook)));
1670 #endif
1671 return (ENOENT);
1672 }
1673
1674 /*
1675 * Hop on over to the next node
1676 * XXX
1677 * Big race conditions here as hooks and nodes go away
1678 * *** Idea.. store an ng_ID_t in each hook and use that
1679 * instead of the direct hook in this crawl?
1680 */
1681 oldnode = node;
1682 if ((node = NG_PEER_NODE(hook)))
1683 NG_NODE_REF(node); /* XXX RACE */
1684 NG_NODE_UNREF(oldnode); /* XXX another race */
1685 if (NG_NODE_NOT_VALID(node)) {
1686 NG_NODE_UNREF(node); /* XXX more races */
1687 node = NULL;
1688 }
1689 }
1690
1691 /* If node somehow missing, fail here (probably this is not needed) */
1692 if (node == NULL) {
1693 TRAP_ERROR();
1694 return (ENXIO);
1695 }
1696
1697 /* Done */
1698 *destp = node;
1699 if (lasthook != NULL)
1700 *lasthook = (hook ? NG_HOOK_PEER(hook) : NULL);
1701 return (0);
1702 }
1703
1704 /***************************************************************\
1705 * Input queue handling.
1706 * All activities are submitted to the node via the input queue
1707 * which implements a multiple-reader/single-writer gate.
1708 * Items which cannot be handled immeditly are queued.
1709 *
1710 * read-write queue locking inline functions *
1711 \***************************************************************/
1712
1713 static __inline item_p ng_dequeue(struct ng_queue * ngq);
1714 static __inline item_p ng_acquire_read(struct ng_queue * ngq,
1715 item_p item);
1716 static __inline item_p ng_acquire_write(struct ng_queue * ngq,
1717 item_p item);
1718 static __inline void ng_leave_read(struct ng_queue * ngq);
1719 static __inline void ng_leave_write(struct ng_queue * ngq);
1720 static __inline void ng_queue_rw(struct ng_queue * ngq,
1721 item_p item, int rw);
1722
1723 /*
1724 * Definition of the bits fields in the ng_queue flag word.
1725 * Defined here rather than in netgraph.h because no-one should fiddle
1726 * with them.
1727 *
1728 * The ordering here may be important! don't shuffle these.
1729 */
1730 /*-
1731 Safety Barrier--------+ (adjustable to suit taste) (not used yet)
1732 |
1733 V
1734 +-------+-------+-------+-------+-------+-------+-------+-------+
1735 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
1736 | |A|c|t|i|v|e| |R|e|a|d|e|r| |C|o|u|n|t| | | | | | | | | |R|A|W|
1737 | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |P|W|P|
1738 +-------+-------+-------+-------+-------+-------+-------+-------+
1739 \___________________________ ____________________________/ | | |
1740 V | | |
1741 [active reader count] | | |
1742 | | |
1743 Read Pending ------------------------------------+ | |
1744 | |
1745 Active Writer -------------------------------------+ |
1746 |
1747 Write Pending ---------------------------------------+
1748
1749
1750 */
1751 #define WRITE_PENDING 0x00000001
1752 #define WRITER_ACTIVE 0x00000002
1753 #define READ_PENDING 0x00000004
1754 #define READER_INCREMENT 0x00000008
1755 #define READER_MASK 0xfffffff0 /* Not valid if WRITER_ACTIVE is set */
1756 #define SAFETY_BARRIER 0x00100000 /* 64K items queued should be enough */
1757
1758 /* Defines of more elaborate states on the queue */
1759 /* Mask of bits a read cares about */
1760 #define NGQ_RMASK (WRITE_PENDING|WRITER_ACTIVE|READ_PENDING)
1761
1762 /* Mask of bits a write cares about */
1763 #define NGQ_WMASK (NGQ_RMASK|READER_MASK)
1764
1765 /* tests to decide if we could get a read or write off the queue */
1766 #define CAN_GET_READ(flag) ((flag & NGQ_RMASK) == READ_PENDING)
1767 #define CAN_GET_WRITE(flag) ((flag & NGQ_WMASK) == WRITE_PENDING)
1768
1769 /* Is there a chance of getting ANY work off the queue? */
1770 #define CAN_GET_WORK(flag) (CAN_GET_READ(flag) || CAN_GET_WRITE(flag))
1771
1772 /*
1773 * Taking into account the current state of the queue and node, possibly take
1774 * the next entry off the queue and return it. Return NULL if there was
1775 * nothing we could return, either because there really was nothing there, or
1776 * because the node was in a state where it cannot yet process the next item
1777 * on the queue.
1778 *
1779 * This MUST MUST MUST be called with the mutex held.
1780 */
1781 static __inline item_p
1782 ng_dequeue(struct ng_queue *ngq)
1783 {
1784 item_p item;
1785 u_int add_arg;
1786
1787 if (CAN_GET_READ(ngq->q_flags)) {
1788 /*
1789 * Head of queue is a reader and we have no write active.
1790 * We don't care how many readers are already active.
1791 * Adjust the flags for the item we are about to dequeue.
1792 * Add the correct increment for the reader count as well.
1793 */
1794 add_arg = (READER_INCREMENT - READ_PENDING);
1795 } else if (CAN_GET_WRITE(ngq->q_flags)) {
1796 /*
1797 * There is a pending write, no readers and no active writer.
1798 * This means we can go ahead with the pending writer. Note
1799 * the fact that we now have a writer, ready for when we take
1800 * it off the queue.
1801 *
1802 * We don't need to worry about a possible collision with the
1803 * fasttrack reader.
1804 *
1805 * The fasttrack thread may take a long time to discover that we
1806 * are running so we would have an inconsistent state in the
1807 * flags for a while. Since we ignore the reader count
1808 * entirely when the WRITER_ACTIVE flag is set, this should
1809 * not matter (in fact it is defined that way). If it tests
1810 * the flag before this operation, the WRITE_PENDING flag
1811 * will make it fail, and if it tests it later, the
1812 * WRITER_ACTIVE flag will do the same. If it is SO slow that
1813 * we have actually completed the operation, and neither flag
1814 * is set (nor the READ_PENDING) by the time that it tests
1815 * the flags, then it is actually ok for it to continue. If
1816 * it completes and we've finished and the read pending is
1817 * set it still fails.
1818 *
1819 * So we can just ignore it, as long as we can ensure that the
1820 * transition from WRITE_PENDING state to the WRITER_ACTIVE
1821 * state is atomic.
1822 *
1823 * After failing, first it will be held back by the mutex, then
1824 * when it can proceed, it will queue its request, then it
1825 * would arrive at this function. Usually it will have to
1826 * leave empty handed because the ACTIVE WRITER bit will be
1827 * set.
1828 *
1829 * Adjust the flags for the item we are about to dequeue
1830 * and for the new active writer.
1831 */
1832 add_arg = (WRITER_ACTIVE - WRITE_PENDING);
1833 /*
1834 * We want to write "active writer, no readers " Now go make
1835 * it true. In fact there may be a number in the readers
1836 * count but we know it is not true and will be fixed soon.
1837 * We will fix the flags for the next pending entry in a
1838 * moment.
1839 */
1840 } else {
1841 /*
1842 * We can't dequeue anything.. return and say so. Probably we
1843 * have a write pending and the readers count is non zero. If
1844 * we got here because a reader hit us just at the wrong
1845 * moment with the fasttrack code, and put us in a strange
1846 * state, then it will be through in just a moment, (as soon
1847 * as we release the mutex) and keep things moving.
1848 * Make sure we remove ourselves from the work queue.
1849 */
1850 ng_worklist_remove(ngq->q_node);
1851 return (0);
1852 }
1853
1854 /*
1855 * Now we dequeue the request (whatever it may be) and correct the
1856 * pending flags and the next and last pointers.
1857 */
1858 item = ngq->queue;
1859 ngq->queue = item->el_next;
1860 if (ngq->last == &(item->el_next)) {
1861 /*
1862 * that was the last entry in the queue so set the 'last
1863 * pointer up correctly and make sure the pending flags are
1864 * clear.
1865 */
1866 ngq->last = &(ngq->queue);
1867 /*
1868 * Whatever flag was set will be cleared and
1869 * the new acive field will be set by the add as well,
1870 * so we don't need to change add_arg.
1871 * But we know we don't need to be on the work list.
1872 */
1873 atomic_add_long(&ngq->q_flags, add_arg);
1874 ng_worklist_remove(ngq->q_node);
1875 } else {
1876 /*
1877 * Since there is something on the queue, note what it is
1878 * in the flags word.
1879 */
1880 if ((ngq->queue->el_flags & NGQF_RW) == NGQF_READER) {
1881 add_arg += READ_PENDING;
1882 } else {
1883 add_arg += WRITE_PENDING;
1884 }
1885 atomic_add_long(&ngq->q_flags, add_arg);
1886 /*
1887 * If we see more doable work, make sure we are
1888 * on the work queue.
1889 */
1890 if (CAN_GET_WORK(ngq->q_flags)) {
1891 ng_setisr(ngq->q_node);
1892 }
1893 }
1894 /*
1895 * We have successfully cleared the old pending flag, set the new one
1896 * if it is needed, and incremented the appropriate active field.
1897 * (all in one atomic addition.. )
1898 */
1899 return (item);
1900 }
1901
1902 /*
1903 * Queue a packet to be picked up by someone else.
1904 * We really don't care who, but we can't or don't want to hang around
1905 * to process it ourselves. We are probably an interrupt routine..
1906 * 1 = writer, 0 = reader
1907 */
1908 #define NGQRW_R 0
1909 #define NGQRW_W 1
1910 static __inline void
1911 ng_queue_rw(struct ng_queue * ngq, item_p item, int rw)
1912 {
1913 item->el_next = NULL; /* maybe not needed */
1914 *ngq->last = item;
1915 /*
1916 * If it was the first item in the queue then we need to
1917 * set the last pointer and the type flags.
1918 */
1919 if (ngq->last == &(ngq->queue)) {
1920 /*
1921 * When called with constants for rw, the optimiser will
1922 * remove the unneeded branch below.
1923 */
1924 if (rw == NGQRW_W) {
1925 atomic_add_long(&ngq->q_flags, WRITE_PENDING);
1926 } else {
1927 atomic_add_long(&ngq->q_flags, READ_PENDING);
1928 }
1929 }
1930 ngq->last = &(item->el_next);
1931 }
1932
1933
1934 /*
1935 * This function 'cheats' in that it first tries to 'grab' the use of the
1936 * node, without going through the mutex. We can do this becasue of the
1937 * semantics of the lock. The semantics include a clause that says that the
1938 * value of the readers count is invalid if the WRITER_ACTIVE flag is set. It
1939 * also says that the WRITER_ACTIVE flag cannot be set if the readers count
1940 * is not zero. Note that this talks about what is valid to SET the
1941 * WRITER_ACTIVE flag, because from the moment it is set, the value if the
1942 * reader count is immaterial, and not valid. The two 'pending' flags have a
1943 * similar effect, in that If they are orthogonal to the two active fields in
1944 * how they are set, but if either is set, the attempted 'grab' need to be
1945 * backed out because there is earlier work, and we maintain ordering in the
1946 * queue. The result of this is that the reader request can try obtain use of
1947 * the node with only a single atomic addition, and without any of the mutex
1948 * overhead. If this fails the operation degenerates to the same as for other
1949 * cases.
1950 *
1951 */
1952 static __inline item_p
1953 ng_acquire_read(struct ng_queue *ngq, item_p item)
1954 {
1955
1956 /* ######### Hack alert ######### */
1957 atomic_add_long(&ngq->q_flags, READER_INCREMENT);
1958 if ((ngq->q_flags & NGQ_RMASK) == 0) {
1959 /* Successfully grabbed node */
1960 return (item);
1961 }
1962 /* undo the damage if we didn't succeed */
1963 atomic_subtract_long(&ngq->q_flags, READER_INCREMENT);
1964
1965 /* ######### End Hack alert ######### */
1966 mtx_lock_spin((&ngq->q_mtx));
1967 /*
1968 * Try again. Another processor (or interrupt for that matter) may
1969 * have removed the last queued item that was stopping us from
1970 * running, between the previous test, and the moment that we took
1971 * the mutex. (Or maybe a writer completed.)
1972 */
1973 if ((ngq->q_flags & NGQ_RMASK) == 0) {
1974 atomic_add_long(&ngq->q_flags, READER_INCREMENT);
1975 mtx_unlock_spin((&ngq->q_mtx));
1976 return (item);
1977 }
1978
1979 /*
1980 * and queue the request for later.
1981 */
1982 item->el_flags |= NGQF_READER;
1983 ng_queue_rw(ngq, item, NGQRW_R);
1984
1985 /*
1986 * Ok, so that's the item successfully queued for later. So now we
1987 * see if we can dequeue something to run instead.
1988 */
1989 item = ng_dequeue(ngq);
1990 mtx_unlock_spin(&(ngq->q_mtx));
1991 return (item);
1992 }
1993
1994 static __inline item_p
1995 ng_acquire_write(struct ng_queue *ngq, item_p item)
1996 {
1997 restart:
1998 mtx_lock_spin(&(ngq->q_mtx));
1999 /*
2000 * If there are no readers, no writer, and no pending packets, then
2001 * we can just go ahead. In all other situations we need to queue the
2002 * request
2003 */
2004 if ((ngq->q_flags & NGQ_WMASK) == 0) {
2005 atomic_add_long(&ngq->q_flags, WRITER_ACTIVE);
2006 mtx_unlock_spin((&ngq->q_mtx));
2007 if (ngq->q_flags & READER_MASK) {
2008 /* Collision with fast-track reader */
2009 atomic_subtract_long(&ngq->q_flags, WRITER_ACTIVE);
2010 goto restart;
2011 }
2012 return (item);
2013 }
2014
2015 /*
2016 * and queue the request for later.
2017 */
2018 item->el_flags &= ~NGQF_RW;
2019 ng_queue_rw(ngq, item, NGQRW_W);
2020
2021 /*
2022 * Ok, so that's the item successfully queued for later. So now we
2023 * see if we can dequeue something to run instead.
2024 */
2025 item = ng_dequeue(ngq);
2026 mtx_unlock_spin(&(ngq->q_mtx));
2027 return (item);
2028 }
2029
2030 static __inline void
2031 ng_leave_read(struct ng_queue *ngq)
2032 {
2033 atomic_subtract_long(&ngq->q_flags, READER_INCREMENT);
2034 }
2035
2036 static __inline void
2037 ng_leave_write(struct ng_queue *ngq)
2038 {
2039 atomic_subtract_long(&ngq->q_flags, WRITER_ACTIVE);
2040 }
2041
2042 static void
2043 ng_flush_input_queue(struct ng_queue * ngq)
2044 {
2045 item_p item;
2046 u_int add_arg;
2047 mtx_lock_spin(&ngq->q_mtx);
2048 for (;;) {
2049 /* Now take a look at what's on the queue */
2050 if (ngq->q_flags & READ_PENDING) {
2051 add_arg = -READ_PENDING;
2052 } else if (ngq->q_flags & WRITE_PENDING) {
2053 add_arg = -WRITE_PENDING;
2054 } else {
2055 break;
2056 }
2057
2058 item = ngq->queue;
2059 ngq->queue = item->el_next;
2060 if (ngq->last == &(item->el_next)) {
2061 ngq->last = &(ngq->queue);
2062 } else {
2063 if ((ngq->queue->el_flags & NGQF_RW) == NGQF_READER) {
2064 add_arg += READ_PENDING;
2065 } else {
2066 add_arg += WRITE_PENDING;
2067 }
2068 }
2069 atomic_add_long(&ngq->q_flags, add_arg);
2070
2071 mtx_lock_spin(&ngq->q_mtx);
2072 NG_FREE_ITEM(item);
2073 mtx_unlock_spin(&ngq->q_mtx);
2074 }
2075 /*
2076 * Take us off the work queue if we are there.
2077 * We definatly have no work to be done.
2078 */
2079 ng_worklist_remove(ngq->q_node);
2080 mtx_unlock_spin(&ngq->q_mtx);
2081 }
2082
2083 /***********************************************************************
2084 * Externally visible method for sending or queueing messages or data.
2085 ***********************************************************************/
2086
2087 /*
2088 * The module code should have filled out the item correctly by this stage:
2089 * Common:
2090 * reference to destination node.
2091 * Reference to destination rcv hook if relevant.
2092 * Data:
2093 * pointer to mbuf
2094 * pointer to metadata
2095 * Control_Message:
2096 * pointer to msg.
2097 * ID of original sender node. (return address)
2098 * Function:
2099 * Function pointer
2100 * void * argument
2101 * integer argument
2102 *
2103 * The nodes have several routines and macros to help with this task:
2104 */
2105
2106 int
2107 ng_snd_item(item_p item, int queue)
2108 {
2109 hook_p hook = NGI_HOOK(item);
2110 node_p node = NGI_NODE(item);
2111 int rw;
2112 int error = 0, ierror;
2113 item_p oitem;
2114 struct ng_queue * ngq = &node->nd_input_queue;
2115
2116 #ifdef NETGRAPH_DEBUG
2117 _ngi_check(item, __FILE__, __LINE__);
2118 #endif
2119
2120 if (item == NULL) {
2121 TRAP_ERROR();
2122 return (EINVAL); /* failed to get queue element */
2123 }
2124 if (node == NULL) {
2125 NG_FREE_ITEM(item);
2126 TRAP_ERROR();
2127 return (EINVAL); /* No address */
2128 }
2129 switch(item->el_flags & NGQF_TYPE) {
2130 case NGQF_DATA:
2131 /*
2132 * DATA MESSAGE
2133 * Delivered to a node via a non-optional hook.
2134 * Both should be present in the item even though
2135 * the node is derivable from the hook.
2136 * References are held on both by the item.
2137 */
2138 CHECK_DATA_MBUF(NGI_M(item));
2139 if (hook == NULL) {
2140 NG_FREE_ITEM(item);
2141 TRAP_ERROR();
2142 return(EINVAL);
2143 }
2144 if ((NG_HOOK_NOT_VALID(hook))
2145 || (NG_NODE_NOT_VALID(NG_HOOK_NODE(hook)))) {
2146 NG_FREE_ITEM(item);
2147 return (ENOTCONN);
2148 }
2149 if ((hook->hk_flags & HK_QUEUE)) {
2150 queue = 1;
2151 }
2152 /* By default data is a reader in the locking scheme */
2153 item->el_flags |= NGQF_READER;
2154 rw = NGQRW_R;
2155 break;
2156 case NGQF_MESG:
2157 /*
2158 * CONTROL MESSAGE
2159 * Delivered to a node.
2160 * Hook is optional.
2161 * References are held by the item on the node and
2162 * the hook if it is present.
2163 */
2164 if (hook && (hook->hk_flags & HK_QUEUE)) {
2165 queue = 1;
2166 }
2167 /* Data messages count as writers unles explicitly exempted */
2168 if (NGI_MSG(item)->header.cmd & NGM_READONLY) {
2169 item->el_flags |= NGQF_READER;
2170 rw = NGQRW_R;
2171 } else {
2172 item->el_flags &= ~NGQF_RW;
2173 rw = NGQRW_W;
2174 }
2175 break;
2176 case NGQF_FN:
2177 item->el_flags &= ~NGQF_RW;
2178 rw = NGQRW_W;
2179 break;
2180 default:
2181 NG_FREE_ITEM(item);
2182 TRAP_ERROR();
2183 return (EINVAL);
2184 }
2185 /*
2186 * If the node specifies single threading, force writer semantics
2187 * Similarly the node may say one hook always produces writers.
2188 * These are over-rides.
2189 */
2190 if ((node->nd_flags & NG_FORCE_WRITER)
2191 || (hook && (hook->hk_flags & HK_FORCE_WRITER))) {
2192 rw = NGQRW_W;
2193 item->el_flags &= ~NGQF_READER;
2194 }
2195 if (queue) {
2196 /* Put it on the queue for that node*/
2197 #ifdef NETGRAPH_DEBUG
2198 _ngi_check(item, __FILE__, __LINE__);
2199 #endif
2200 mtx_lock_spin(&(ngq->q_mtx));
2201 ng_queue_rw(ngq, item, rw);
2202 /*
2203 * If there are active elements then we can rely on
2204 * them. if not we should not rely on another packet
2205 * coming here by another path,
2206 * so it is best to put us in the netisr list.
2207 * We can take the worklist lock with the node locked
2208 * BUT NOT THE REVERSE!
2209 */
2210 if (CAN_GET_WORK(ngq->q_flags)) {
2211 ng_setisr(node);
2212 }
2213 mtx_unlock_spin(&(ngq->q_mtx));
2214 return (0);
2215 }
2216 /*
2217 * Take a queue item and a node and see if we can apply the item to
2218 * the node. We may end up getting a different item to apply instead.
2219 * Will allow for a piggyback reply only in the case where
2220 * there is no queueing.
2221 */
2222
2223 oitem = item;
2224 /*
2225 * We already decided how we will be queueud or treated.
2226 * Try get the appropriate operating permission.
2227 */
2228 if (rw == NGQRW_R) {
2229 item = ng_acquire_read(ngq, item);
2230 } else {
2231 item = ng_acquire_write(ngq, item);
2232 }
2233
2234 /*
2235 * May have come back with a different item.
2236 * or maybe none at all. The one we started with will
2237 * have been queued in thises cases.
2238 */
2239 if (item == NULL) {
2240 return (0);
2241 }
2242
2243 #ifdef NETGRAPH_DEBUG
2244 _ngi_check(item, __FILE__, __LINE__);
2245 #endif
2246 /*
2247 * Take over the reference frm the item.
2248 * Hold it until the called function returns.
2249 */
2250 NGI_GET_NODE(item, node); /* zaps stored node */
2251
2252 ierror = ng_apply_item(node, item); /* drops r/w lock when done */
2253
2254 /* only return an error if it was our initial item.. (compat hack) */
2255 if (oitem == item) {
2256 error = ierror;
2257 }
2258
2259 /*
2260 * If the node goes away when we remove the reference,
2261 * whatever we just did caused it.. whatever we do, DO NOT
2262 * access the node again!
2263 */
2264 if (NG_NODE_UNREF(node) == 0) {
2265 return (error);
2266 }
2267
2268 /*
2269 * Now we've handled the packet we brought, (or a friend of it) let's
2270 * look for any other packets that may have been queued up. We hold
2271 * no locks, so if someone puts something in the queue after
2272 * we check that it is empty, it is their problem
2273 * to ensure it is processed. If we have the netisr thread cme in here
2274 * while we still say we have stuff to do, we may get a boost
2275 * in SMP systems. :-)
2276 */
2277 for (;;) {
2278 /*
2279 * dequeue acquires and adjusts the input_queue as it dequeues
2280 * packets. It acquires the rw lock as needed.
2281 */
2282 mtx_lock_spin(&ngq->q_mtx);
2283 item = ng_dequeue(ngq); /* fixes worklist too*/
2284 if (!item) {
2285 mtx_unlock_spin(&ngq->q_mtx);
2286 return (error);
2287 }
2288 mtx_unlock_spin(&ngq->q_mtx);
2289
2290 /*
2291 * Take over the reference frm the item.
2292 * Hold it until the called function returns.
2293 */
2294
2295 NGI_GET_NODE(item, node); /* zaps stored node */
2296
2297 /*
2298 * We have the appropriate lock, so run the item.
2299 * When finished it will drop the lock accordingly
2300 */
2301 ierror = ng_apply_item(node, item);
2302
2303 /*
2304 * only return an error if it was our initial
2305 * item.. (compat hack)
2306 */
2307 if (oitem == item) {
2308 error = ierror;
2309 }
2310
2311 /*
2312 * If the node goes away when we remove the reference,
2313 * whatever we just did caused it.. whatever we do, DO NOT
2314 * access the node again!
2315 */
2316 if (NG_NODE_UNREF(node) == 0) {
2317 break;
2318 }
2319 }
2320 return (error);
2321 }
2322
2323 /*
2324 * We have an item that was possibly queued somewhere.
2325 * It should contain all the information needed
2326 * to run it on the appropriate node/hook.
2327 */
2328 static int
2329 ng_apply_item(node_p node, item_p item)
2330 {
2331 hook_p hook;
2332 int was_reader = ((item->el_flags & NGQF_RW));
2333 int error = 0;
2334 ng_rcvdata_t *rcvdata;
2335 ng_rcvmsg_t *rcvmsg;
2336
2337 NGI_GET_HOOK(item, hook); /* clears stored hook */
2338 #ifdef NETGRAPH_DEBUG
2339 _ngi_check(item, __FILE__, __LINE__);
2340 #endif
2341 switch (item->el_flags & NGQF_TYPE) {
2342 case NGQF_DATA:
2343 /*
2344 * Check things are still ok as when we were queued.
2345 */
2346 if ((hook == NULL)
2347 || NG_HOOK_NOT_VALID(hook)
2348 || NG_NODE_NOT_VALID(node) ) {
2349 error = EIO;
2350 NG_FREE_ITEM(item);
2351 break;
2352 }
2353 /*
2354 * If no receive method, just silently drop it.
2355 * Give preference to the hook over-ride method
2356 */
2357 if ((!(rcvdata = hook->hk_rcvdata))
2358 && (!(rcvdata = NG_HOOK_NODE(hook)->nd_type->rcvdata))) {
2359 error = 0;
2360 NG_FREE_ITEM(item);
2361 break;
2362 }
2363 error = (*rcvdata)(hook, item);
2364 break;
2365 case NGQF_MESG:
2366 if (hook) {
2367 if (NG_HOOK_NOT_VALID(hook)) {
2368 /*
2369 * The hook has been zapped then we can't
2370 * use it. Immediatly drop its reference.
2371 * The message may not need it.
2372 */
2373 NG_HOOK_UNREF(hook);
2374 hook = NULL;
2375 }
2376 }
2377 /*
2378 * Similarly, if the node is a zombie there is
2379 * nothing we can do with it, drop everything.
2380 */
2381 if (NG_NODE_NOT_VALID(node)) {
2382 TRAP_ERROR();
2383 error = EINVAL;
2384 NG_FREE_ITEM(item);
2385 } else {
2386 /*
2387 * Call the appropriate message handler for the object.
2388 * It is up to the message handler to free the message.
2389 * If it's a generic message, handle it generically,
2390 * otherwise call the type's message handler
2391 * (if it exists)
2392 * XXX (race). Remember that a queued message may
2393 * reference a node or hook that has just been
2394 * invalidated. It will exist as the queue code
2395 * is holding a reference, but..
2396 */
2397
2398 struct ng_mesg *msg = NGI_MSG(item);
2399
2400 /*
2401 * check if the generic handler owns it.
2402 */
2403 if ((msg->header.typecookie == NGM_GENERIC_COOKIE)
2404 && ((msg->header.flags & NGF_RESP) == 0)) {
2405 error = ng_generic_msg(node, item, hook);
2406 break;
2407 }
2408 /*
2409 * Now see if there is a handler (hook or node specific)
2410 * in the target node. If none, silently discard.
2411 */
2412 if (((!hook) || (!(rcvmsg = hook->hk_rcvmsg)))
2413 && (!(rcvmsg = node->nd_type->rcvmsg))) {
2414 TRAP_ERROR();
2415 error = 0;
2416 NG_FREE_ITEM(item);
2417 break;
2418 }
2419 error = (*rcvmsg)(node, item, hook);
2420 }
2421 break;
2422 case NGQF_FN:
2423 /*
2424 * We have to implicitly trust the hook,
2425 * as some of these are used for system purposes
2426 * where the hook is invalid. In the case of
2427 * the shutdown message we allow it to hit
2428 * even if the node is invalid.
2429 */
2430 if ((NG_NODE_NOT_VALID(node))
2431 && (NGI_FN(item) != &ng_rmnode)) {
2432 TRAP_ERROR();
2433 error = EINVAL;
2434 break;
2435 }
2436 (*NGI_FN(item))(node, hook, NGI_ARG1(item), NGI_ARG2(item));
2437 NG_FREE_ITEM(item);
2438 break;
2439
2440 }
2441 /*
2442 * We held references on some of the resources
2443 * that we took from the item. Now that we have
2444 * finished doing everything, drop those references.
2445 */
2446 if (hook) {
2447 NG_HOOK_UNREF(hook);
2448 }
2449
2450 if (was_reader) {
2451 ng_leave_read(&node->nd_input_queue);
2452 } else {
2453 ng_leave_write(&node->nd_input_queue);
2454 }
2455 return (error);
2456 }
2457
2458 /***********************************************************************
2459 * Implement the 'generic' control messages
2460 ***********************************************************************/
2461 static int
2462 ng_generic_msg(node_p here, item_p item, hook_p lasthook)
2463 {
2464 int error = 0;
2465 struct ng_mesg *msg;
2466 struct ng_mesg *resp = NULL;
2467
2468 NGI_GET_MSG(item, msg);
2469 if (msg->header.typecookie != NGM_GENERIC_COOKIE) {
2470 TRAP_ERROR();
2471 error = EINVAL;
2472 goto out;
2473 }
2474 switch (msg->header.cmd) {
2475 case NGM_SHUTDOWN:
2476 ng_rmnode(here, NULL, NULL, 0);
2477 break;
2478 case NGM_MKPEER:
2479 {
2480 struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
2481
2482 if (msg->header.arglen != sizeof(*mkp)) {
2483 TRAP_ERROR();
2484 error = EINVAL;
2485 break;
2486 }
2487 mkp->type[sizeof(mkp->type) - 1] = '\0';
2488 mkp->ourhook[sizeof(mkp->ourhook) - 1] = '\0';
2489 mkp->peerhook[sizeof(mkp->peerhook) - 1] = '\0';
2490 error = ng_mkpeer(here, mkp->ourhook, mkp->peerhook, mkp->type);
2491 break;
2492 }
2493 case NGM_CONNECT:
2494 {
2495 struct ngm_connect *const con =
2496 (struct ngm_connect *) msg->data;
2497 node_p node2;
2498
2499 if (msg->header.arglen != sizeof(*con)) {
2500 TRAP_ERROR();
2501 error = EINVAL;
2502 break;
2503 }
2504 con->path[sizeof(con->path) - 1] = '\0';
2505 con->ourhook[sizeof(con->ourhook) - 1] = '\0';
2506 con->peerhook[sizeof(con->peerhook) - 1] = '\0';
2507 /* Don't forget we get a reference.. */
2508 error = ng_path2noderef(here, con->path, &node2, NULL);
2509 if (error)
2510 break;
2511 error = ng_con_nodes(here, con->ourhook, node2, con->peerhook);
2512 NG_NODE_UNREF(node2);
2513 break;
2514 }
2515 case NGM_NAME:
2516 {
2517 struct ngm_name *const nam = (struct ngm_name *) msg->data;
2518
2519 if (msg->header.arglen != sizeof(*nam)) {
2520 TRAP_ERROR();
2521 error = EINVAL;
2522 break;
2523 }
2524 nam->name[sizeof(nam->name) - 1] = '\0';
2525 error = ng_name_node(here, nam->name);
2526 break;
2527 }
2528 case NGM_RMHOOK:
2529 {
2530 struct ngm_rmhook *const rmh = (struct ngm_rmhook *) msg->data;
2531 hook_p hook;
2532
2533 if (msg->header.arglen != sizeof(*rmh)) {
2534 TRAP_ERROR();
2535 error = EINVAL;
2536 break;
2537 }
2538 rmh->ourhook[sizeof(rmh->ourhook) - 1] = '\0';
2539 if ((hook = ng_findhook(here, rmh->ourhook)) != NULL)
2540 ng_destroy_hook(hook);
2541 break;
2542 }
2543 case NGM_NODEINFO:
2544 {
2545 struct nodeinfo *ni;
2546
2547 NG_MKRESPONSE(resp, msg, sizeof(*ni), M_NOWAIT);
2548 if (resp == NULL) {
2549 error = ENOMEM;
2550 break;
2551 }
2552
2553 /* Fill in node info */
2554 ni = (struct nodeinfo *) resp->data;
2555 if (NG_NODE_HAS_NAME(here))
2556 strncpy(ni->name, NG_NODE_NAME(here), NG_NODELEN);
2557 strncpy(ni->type, here->nd_type->name, NG_TYPELEN);
2558 ni->id = ng_node2ID(here);
2559 ni->hooks = here->nd_numhooks;
2560 break;
2561 }
2562 case NGM_LISTHOOKS:
2563 {
2564 const int nhooks = here->nd_numhooks;
2565 struct hooklist *hl;
2566 struct nodeinfo *ni;
2567 hook_p hook;
2568
2569 /* Get response struct */
2570 NG_MKRESPONSE(resp, msg, sizeof(*hl)
2571 + (nhooks * sizeof(struct linkinfo)), M_NOWAIT);
2572 if (resp == NULL) {
2573 error = ENOMEM;
2574 break;
2575 }
2576 hl = (struct hooklist *) resp->data;
2577 ni = &hl->nodeinfo;
2578
2579 /* Fill in node info */
2580 if (NG_NODE_HAS_NAME(here))
2581 strncpy(ni->name, NG_NODE_NAME(here), NG_NODELEN);
2582 strncpy(ni->type, here->nd_type->name, NG_TYPELEN);
2583 ni->id = ng_node2ID(here);
2584
2585 /* Cycle through the linked list of hooks */
2586 ni->hooks = 0;
2587 LIST_FOREACH(hook, &here->nd_hooks, hk_hooks) {
2588 struct linkinfo *const link = &hl->link[ni->hooks];
2589
2590 if (ni->hooks >= nhooks) {
2591 log(LOG_ERR, "%s: number of %s changed\n",
2592 __func__, "hooks");
2593 break;
2594 }
2595 if (NG_HOOK_NOT_VALID(hook))
2596 continue;
2597 strncpy(link->ourhook, NG_HOOK_NAME(hook), NG_HOOKLEN);
2598 strncpy(link->peerhook,
2599 NG_PEER_HOOK_NAME(hook), NG_HOOKLEN);
2600 if (NG_PEER_NODE_NAME(hook)[0] != '\0')
2601 strncpy(link->nodeinfo.name,
2602 NG_PEER_NODE_NAME(hook), NG_NODELEN);
2603 strncpy(link->nodeinfo.type,
2604 NG_PEER_NODE(hook)->nd_type->name, NG_TYPELEN);
2605 link->nodeinfo.id = ng_node2ID(NG_PEER_NODE(hook));
2606 link->nodeinfo.hooks = NG_PEER_NODE(hook)->nd_numhooks;
2607 ni->hooks++;
2608 }
2609 break;
2610 }
2611
2612 case NGM_LISTNAMES:
2613 case NGM_LISTNODES:
2614 {
2615 const int unnamed = (msg->header.cmd == NGM_LISTNODES);
2616 struct namelist *nl;
2617 node_p node;
2618 int num = 0;
2619
2620 mtx_lock(&ng_nodelist_mtx);
2621 /* Count number of nodes */
2622 LIST_FOREACH(node, &ng_nodelist, nd_nodes) {
2623 if (NG_NODE_IS_VALID(node)
2624 && (unnamed || NG_NODE_HAS_NAME(node))) {
2625 num++;
2626 }
2627 }
2628 mtx_unlock(&ng_nodelist_mtx);
2629
2630 /* Get response struct */
2631 NG_MKRESPONSE(resp, msg, sizeof(*nl)
2632 + (num * sizeof(struct nodeinfo)), M_NOWAIT);
2633 if (resp == NULL) {
2634 error = ENOMEM;
2635 break;
2636 }
2637 nl = (struct namelist *) resp->data;
2638
2639 /* Cycle through the linked list of nodes */
2640 nl->numnames = 0;
2641 mtx_lock(&ng_nodelist_mtx);
2642 LIST_FOREACH(node, &ng_nodelist, nd_nodes) {
2643 struct nodeinfo *const np = &nl->nodeinfo[nl->numnames];
2644
2645 if (nl->numnames >= num) {
2646 log(LOG_ERR, "%s: number of %s changed\n",
2647 __func__, "nodes");
2648 break;
2649 }
2650 if (NG_NODE_NOT_VALID(node))
2651 continue;
2652 if (!unnamed && (! NG_NODE_HAS_NAME(node)))
2653 continue;
2654 if (NG_NODE_HAS_NAME(node))
2655 strncpy(np->name, NG_NODE_NAME(node), NG_NODELEN);
2656 strncpy(np->type, node->nd_type->name, NG_TYPELEN);
2657 np->id = ng_node2ID(node);
2658 np->hooks = node->nd_numhooks;
2659 nl->numnames++;
2660 }
2661 mtx_unlock(&ng_nodelist_mtx);
2662 break;
2663 }
2664
2665 case NGM_LISTTYPES:
2666 {
2667 struct typelist *tl;
2668 struct ng_type *type;
2669 int num = 0;
2670
2671 mtx_lock(&ng_typelist_mtx);
2672 /* Count number of types */
2673 LIST_FOREACH(type, &ng_typelist, types) {
2674 num++;
2675 }
2676 mtx_unlock(&ng_typelist_mtx);
2677
2678 /* Get response struct */
2679 NG_MKRESPONSE(resp, msg, sizeof(*tl)
2680 + (num * sizeof(struct typeinfo)), M_NOWAIT);
2681 if (resp == NULL) {
2682 error = ENOMEM;
2683 break;
2684 }
2685 tl = (struct typelist *) resp->data;
2686
2687 /* Cycle through the linked list of types */
2688 tl->numtypes = 0;
2689 mtx_lock(&ng_typelist_mtx);
2690 LIST_FOREACH(type, &ng_typelist, types) {
2691 struct typeinfo *const tp = &tl->typeinfo[tl->numtypes];
2692
2693 if (tl->numtypes >= num) {
2694 log(LOG_ERR, "%s: number of %s changed\n",
2695 __func__, "types");
2696 break;
2697 }
2698 strncpy(tp->type_name, type->name, NG_TYPELEN);
2699 tp->numnodes = type->refs - 1; /* don't count list */
2700 tl->numtypes++;
2701 }
2702 mtx_unlock(&ng_typelist_mtx);
2703 break;
2704 }
2705
2706 case NGM_BINARY2ASCII:
2707 {
2708 int bufSize = 20 * 1024; /* XXX hard coded constant */
2709 const struct ng_parse_type *argstype;
2710 const struct ng_cmdlist *c;
2711 struct ng_mesg *binary, *ascii;
2712
2713 /* Data area must contain a valid netgraph message */
2714 binary = (struct ng_mesg *)msg->data;
2715 if (msg->header.arglen < sizeof(struct ng_mesg)
2716 || (msg->header.arglen - sizeof(struct ng_mesg)
2717 < binary->header.arglen)) {
2718 TRAP_ERROR();
2719 error = EINVAL;
2720 break;
2721 }
2722
2723 /* Get a response message with lots of room */
2724 NG_MKRESPONSE(resp, msg, sizeof(*ascii) + bufSize, M_NOWAIT);
2725 if (resp == NULL) {
2726 error = ENOMEM;
2727 break;
2728 }
2729 ascii = (struct ng_mesg *)resp->data;
2730
2731 /* Copy binary message header to response message payload */
2732 bcopy(binary, ascii, sizeof(*binary));
2733
2734 /* Find command by matching typecookie and command number */
2735 for (c = here->nd_type->cmdlist;
2736 c != NULL && c->name != NULL; c++) {
2737 if (binary->header.typecookie == c->cookie
2738 && binary->header.cmd == c->cmd)
2739 break;
2740 }
2741 if (c == NULL || c->name == NULL) {
2742 for (c = ng_generic_cmds; c->name != NULL; c++) {
2743 if (binary->header.typecookie == c->cookie
2744 && binary->header.cmd == c->cmd)
2745 break;
2746 }
2747 if (c->name == NULL) {
2748 NG_FREE_MSG(resp);
2749 error = ENOSYS;
2750 break;
2751 }
2752 }
2753
2754 /* Convert command name to ASCII */
2755 snprintf(ascii->header.cmdstr, sizeof(ascii->header.cmdstr),
2756 "%s", c->name);
2757
2758 /* Convert command arguments to ASCII */
2759 argstype = (binary->header.flags & NGF_RESP) ?
2760 c->respType : c->mesgType;
2761 if (argstype == NULL) {
2762 *ascii->data = '\0';
2763 } else {
2764 if ((error = ng_unparse(argstype,
2765 (u_char *)binary->data,
2766 ascii->data, bufSize)) != 0) {
2767 NG_FREE_MSG(resp);
2768 break;
2769 }
2770 }
2771
2772 /* Return the result as struct ng_mesg plus ASCII string */
2773 bufSize = strlen(ascii->data) + 1;
2774 ascii->header.arglen = bufSize;
2775 resp->header.arglen = sizeof(*ascii) + bufSize;
2776 break;
2777 }
2778
2779 case NGM_ASCII2BINARY:
2780 {
2781 int bufSize = 2000; /* XXX hard coded constant */
2782 const struct ng_cmdlist *c;
2783 const struct ng_parse_type *argstype;
2784 struct ng_mesg *ascii, *binary;
2785 int off = 0;
2786
2787 /* Data area must contain at least a struct ng_mesg + '\0' */
2788 ascii = (struct ng_mesg *)msg->data;
2789 if ((msg->header.arglen < sizeof(*ascii) + 1)
2790 || (ascii->header.arglen < 1)
2791 || (msg->header.arglen
2792 < sizeof(*ascii) + ascii->header.arglen)) {
2793 TRAP_ERROR();
2794 error = EINVAL;
2795 break;
2796 }
2797 ascii->data[ascii->header.arglen - 1] = '\0';
2798
2799 /* Get a response message with lots of room */
2800 NG_MKRESPONSE(resp, msg, sizeof(*binary) + bufSize, M_NOWAIT);
2801 if (resp == NULL) {
2802 error = ENOMEM;
2803 break;
2804 }
2805 binary = (struct ng_mesg *)resp->data;
2806
2807 /* Copy ASCII message header to response message payload */
2808 bcopy(ascii, binary, sizeof(*ascii));
2809
2810 /* Find command by matching ASCII command string */
2811 for (c = here->nd_type->cmdlist;
2812 c != NULL && c->name != NULL; c++) {
2813 if (strcmp(ascii->header.cmdstr, c->name) == 0)
2814 break;
2815 }
2816 if (c == NULL || c->name == NULL) {
2817 for (c = ng_generic_cmds; c->name != NULL; c++) {
2818 if (strcmp(ascii->header.cmdstr, c->name) == 0)
2819 break;
2820 }
2821 if (c->name == NULL) {
2822 NG_FREE_MSG(resp);
2823 error = ENOSYS;
2824 break;
2825 }
2826 }
2827
2828 /* Convert command name to binary */
2829 binary->header.cmd = c->cmd;
2830 binary->header.typecookie = c->cookie;
2831
2832 /* Convert command arguments to binary */
2833 argstype = (binary->header.flags & NGF_RESP) ?
2834 c->respType : c->mesgType;
2835 if (argstype == NULL) {
2836 bufSize = 0;
2837 } else {
2838 if ((error = ng_parse(argstype, ascii->data,
2839 &off, (u_char *)binary->data, &bufSize)) != 0) {
2840 NG_FREE_MSG(resp);
2841 break;
2842 }
2843 }
2844
2845 /* Return the result */
2846 binary->header.arglen = bufSize;
2847 resp->header.arglen = sizeof(*binary) + bufSize;
2848 break;
2849 }
2850
2851 case NGM_TEXT_CONFIG:
2852 case NGM_TEXT_STATUS:
2853 /*
2854 * This one is tricky as it passes the command down to the
2855 * actual node, even though it is a generic type command.
2856 * This means we must assume that the item/msg is already freed
2857 * when control passes back to us.
2858 */
2859 if (here->nd_type->rcvmsg != NULL) {
2860 NGI_MSG(item) = msg; /* put it back as we found it */
2861 return((*here->nd_type->rcvmsg)(here, item, lasthook));
2862 }
2863 /* Fall through if rcvmsg not supported */
2864 default:
2865 TRAP_ERROR();
2866 error = EINVAL;
2867 }
2868 /*
2869 * Sometimes a generic message may be statically allocated
2870 * to avoid problems with allocating when in tight memeory situations.
2871 * Don't free it if it is so.
2872 * I break them appart here, because erros may cause a free if the item
2873 * in which case we'd be doing it twice.
2874 * they are kept together above, to simplify freeing.
2875 */
2876 out:
2877 NG_RESPOND_MSG(error, here, item, resp);
2878 if (msg)
2879 NG_FREE_MSG(msg);
2880 return (error);
2881 }
2882
2883 /*
2884 * Copy a 'meta'.
2885 *
2886 * Returns new meta, or NULL if original meta is NULL or ENOMEM.
2887 */
2888 meta_p
2889 ng_copy_meta(meta_p meta)
2890 {
2891 meta_p meta2;
2892
2893 if (meta == NULL)
2894 return (NULL);
2895 MALLOC(meta2, meta_p, meta->used_len, M_NETGRAPH_META, M_NOWAIT);
2896 if (meta2 == NULL)
2897 return (NULL);
2898 meta2->allocated_len = meta->used_len;
2899 bcopy(meta, meta2, meta->used_len);
2900 return (meta2);
2901 }
2902
2903 /************************************************************************
2904 Module routines
2905 ************************************************************************/
2906
2907 /*
2908 * Handle the loading/unloading of a netgraph node type module
2909 */
2910 int
2911 ng_mod_event(module_t mod, int event, void *data)
2912 {
2913 struct ng_type *const type = data;
2914 int s, error = 0;
2915
2916 switch (event) {
2917 case MOD_LOAD:
2918
2919 /* Register new netgraph node type */
2920 s = splnet();
2921 if ((error = ng_newtype(type)) != 0) {
2922 splx(s);
2923 break;
2924 }
2925
2926 /* Call type specific code */
2927 if (type->mod_event != NULL)
2928 if ((error = (*type->mod_event)(mod, event, data))) {
2929 mtx_lock(&ng_typelist_mtx);
2930 type->refs--; /* undo it */
2931 LIST_REMOVE(type, types);
2932 mtx_unlock(&ng_typelist_mtx);
2933 }
2934 splx(s);
2935 break;
2936
2937 case MOD_UNLOAD:
2938 s = splnet();
2939 if (type->refs > 1) { /* make sure no nodes exist! */
2940 error = EBUSY;
2941 } else {
2942 if (type->refs == 0) {
2943 /* failed load, nothing to undo */
2944 splx(s);
2945 break;
2946 }
2947 if (type->mod_event != NULL) { /* check with type */
2948 error = (*type->mod_event)(mod, event, data);
2949 if (error != 0) { /* type refuses.. */
2950 splx(s);
2951 break;
2952 }
2953 }
2954 mtx_lock(&ng_typelist_mtx);
2955 LIST_REMOVE(type, types);
2956 mtx_unlock(&ng_typelist_mtx);
2957 }
2958 splx(s);
2959 break;
2960
2961 default:
2962 if (type->mod_event != NULL)
2963 error = (*type->mod_event)(mod, event, data);
2964 else
2965 error = 0; /* XXX ? */
2966 break;
2967 }
2968 return (error);
2969 }
2970
2971 /*
2972 * Handle loading and unloading for this code.
2973 * The only thing we need to link into is the NETISR strucure.
2974 */
2975 static int
2976 ngb_mod_event(module_t mod, int event, void *data)
2977 {
2978 int s, error = 0;
2979
2980 switch (event) {
2981 case MOD_LOAD:
2982 /* Register line discipline */
2983 mtx_init(&ng_worklist_mtx, "ng_worklist", NULL, MTX_SPIN);
2984 mtx_init(&ng_typelist_mtx, "netgraph types mutex", NULL, 0);
2985 mtx_init(&ng_nodelist_mtx, "netgraph nodelist mutex", NULL, 0);
2986 mtx_init(&ng_idhash_mtx, "netgraph idhash mutex", NULL, 0);
2987 mtx_init(&ngq_mtx, "netgraph netisr mutex", NULL, 0);
2988 s = splimp();
2989 netisr_register(NETISR_NETGRAPH, (netisr_t *)ngintr, NULL);
2990 splx(s);
2991 break;
2992 case MOD_UNLOAD:
2993 /* You cant unload it because an interface may be using it. */
2994 error = EBUSY;
2995 break;
2996 default:
2997 error = EOPNOTSUPP;
2998 break;
2999 }
3000 return (error);
3001 }
3002
3003 static moduledata_t netgraph_mod = {
3004 "netgraph",
3005 ngb_mod_event,
3006 (NULL)
3007 };
3008 DECLARE_MODULE(netgraph, netgraph_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
3009 SYSCTL_NODE(_net, OID_AUTO, graph, CTLFLAG_RW, 0, "netgraph Family");
3010 SYSCTL_INT(_net_graph, OID_AUTO, abi_version, CTLFLAG_RD, 0, NG_ABI_VERSION,"");
3011 SYSCTL_INT(_net_graph, OID_AUTO, msg_version, CTLFLAG_RD, 0, NG_VERSION, "");
3012
3013 /************************************************************************
3014 Queue element get/free routines
3015 ************************************************************************/
3016
3017
3018 static int allocated; /* number of items malloc'd */
3019
3020 static int maxalloc = 128; /* limit the damage of a leak */
3021 static int ngqfreemax = 64;/* cache at most this many */
3022
3023 TUNABLE_INT("net.graph.maxalloc", &maxalloc);
3024 SYSCTL_INT(_net_graph, OID_AUTO, maxalloc, CTLFLAG_RD, &maxalloc,
3025 0, "Maximum number of queue items to allocate");
3026
3027 TUNABLE_INT("net.graph.ngqfreemax", &ngqfreemax);
3028 SYSCTL_INT(_net_graph, OID_AUTO, ngqfreemax, CTLFLAG_RD, &ngqfreemax,
3029 0, "Maximum number of free queue items to cache");
3030
3031 static const int ngqfreelow = 4; /* try malloc if free < this */
3032 static volatile int ngqfreesize; /* number of cached entries */
3033 #ifdef NETGRAPH_DEBUG
3034 static TAILQ_HEAD(, ng_item) ng_itemlist = TAILQ_HEAD_INITIALIZER(ng_itemlist);
3035 #endif
3036 /*
3037 * Get a queue entry
3038 * This is usually called when a packet first enters netgraph.
3039 * By definition, this is usually from an interrupt, or from a user.
3040 * Users are not so important, but try be quick for the times that it's
3041 * an interrupt. Use atomic operations to cope with collisions
3042 * with interrupts and other processors. Assumes MALLOC is SMP safe.
3043 * XXX If reserve is low, we should try to get 2 from malloc as this
3044 * would indicate it often fails.
3045 */
3046 static item_p
3047 ng_getqblk(void)
3048 {
3049 item_p item = NULL;
3050
3051 /*
3052 * Try get a cached queue block, or else allocate a new one
3053 * If we are less than our reserve, try malloc. If malloc
3054 * fails, then that's what the reserve is for...
3055 * Don't completely trust ngqfreesize, as it is subject
3056 * to races.. (it'll eventually catch up but may be out by one or two
3057 * for brief moments(under SMP or interrupts).
3058 * ngqfree is the final arbiter. We have our little reserve
3059 * because we use M_NOWAIT for malloc. This just helps us
3060 * avoid dropping packets while not increasing the time
3061 * we take to service the interrupt (on average) (I hope).
3062 */
3063 for (;;) {
3064 if ((ngqfreesize < ngqfreelow) || (ngqfree == NULL)) {
3065 if (allocated < maxalloc) { /* don't leak forever */
3066 MALLOC(item, item_p ,
3067 sizeof(*item), M_NETGRAPH_ITEM,
3068 (M_NOWAIT | M_ZERO));
3069 if (item) {
3070 #ifdef NETGRAPH_DEBUG
3071 TAILQ_INSERT_TAIL(&ng_itemlist,
3072 item, all);
3073 #endif /* NETGRAPH_DEBUG */
3074 atomic_add_int(&allocated, 1);
3075 break;
3076 }
3077 }
3078 }
3079
3080 /*
3081 * We didn't or couldn't malloc.
3082 * try get one from our cache.
3083 * item must be NULL to get here.
3084 */
3085 if ((item = ngqfree) != NULL) {
3086 /*
3087 * Atomically try grab the first item
3088 * and put it's successor in its place.
3089 * If we fail, just try again.. someone else
3090 * beat us to this one or freed one.
3091 * Don't worry about races with ngqfreesize.
3092 * Close enough is good enough..
3093 */
3094 if (atomic_cmpset_ptr(&ngqfree, item, item->el_next)) {
3095 atomic_subtract_int(&ngqfreesize, 1);
3096 item->el_flags &= ~NGQF_FREE;
3097 break;
3098 }
3099 /*
3100 * something got there before we did.. try again
3101 * (go around the loop again)
3102 */
3103 item = NULL;
3104 } else {
3105 /* We really ran out */
3106 break;
3107 }
3108 }
3109 return (item);
3110 }
3111
3112 /*
3113 * Release a queue entry
3114 */
3115 void
3116 ng_free_item(item_p item)
3117 {
3118
3119 /*
3120 * The item may hold resources on it's own. We need to free
3121 * these before we can free the item. What they are depends upon
3122 * what kind of item it is. it is important that nodes zero
3123 * out pointers to resources that they remove from the item
3124 * or we release them again here.
3125 */
3126 if (item->el_flags & NGQF_FREE) {
3127 panic(" Freeing free queue item");
3128 }
3129 switch (item->el_flags & NGQF_TYPE) {
3130 case NGQF_DATA:
3131 /* If we have an mbuf and metadata still attached.. */
3132 NG_FREE_M(_NGI_M(item));
3133 NG_FREE_META(_NGI_META(item));
3134 break;
3135 case NGQF_MESG:
3136 _NGI_RETADDR(item) = 0;
3137 NG_FREE_MSG(_NGI_MSG(item));
3138 break;
3139 case NGQF_FN:
3140 /* nothing to free really, */
3141 _NGI_FN(item) = NULL;
3142 _NGI_ARG1(item) = NULL;
3143 _NGI_ARG2(item) = 0;
3144 case NGQF_UNDEF:
3145 break;
3146 }
3147 /* If we still have a node or hook referenced... */
3148 _NGI_CLR_NODE(item);
3149 _NGI_CLR_HOOK(item);
3150 item->el_flags |= NGQF_FREE;
3151
3152 /*
3153 * We have freed any resources held by the item.
3154 * now we can free the item itself.
3155 */
3156 if (ngqfreesize < ngqfreemax) { /* don't worry about races */
3157 for (;;) {
3158 item->el_next = ngqfree;
3159 if (atomic_cmpset_ptr(&ngqfree, item->el_next, item)) {
3160 break;
3161 }
3162 }
3163 atomic_add_int(&ngqfreesize, 1);
3164 } else {
3165 /* This is the only place that should use this Macro */
3166 #ifdef NETGRAPH_DEBUG
3167 TAILQ_REMOVE(&ng_itemlist, item, all);
3168 #endif /* NETGRAPH_DEBUG */
3169 NG_FREE_ITEM_REAL(item);
3170 atomic_subtract_int(&allocated, 1);
3171 }
3172 }
3173
3174 #ifdef NETGRAPH_DEBUG
3175 void
3176 dumphook (hook_p hook, char *file, int line)
3177 {
3178 printf("hook: name %s, %d refs, Last touched:\n",
3179 _NG_HOOK_NAME(hook), hook->hk_refs);
3180 printf(" Last active @ %s, line %d\n",
3181 hook->lastfile, hook->lastline);
3182 if (line) {
3183 printf(" problem discovered at file %s, line %d\n", file, line);
3184 }
3185 }
3186
3187 void
3188 dumpnode(node_p node, char *file, int line)
3189 {
3190 printf("node: ID [%x]: type '%s', %d hooks, flags 0x%x, %d refs, %s:\n",
3191 _NG_NODE_ID(node), node->nd_type->name,
3192 node->nd_numhooks, node->nd_flags,
3193 node->nd_refs, node->nd_name);
3194 printf(" Last active @ %s, line %d\n",
3195 node->lastfile, node->lastline);
3196 if (line) {
3197 printf(" problem discovered at file %s, line %d\n", file, line);
3198 }
3199 }
3200
3201 void
3202 dumpitem(item_p item, char *file, int line)
3203 {
3204 if (item->el_flags & NGQF_FREE) {
3205 printf(" Free item, freed at %s, line %d\n",
3206 item->lastfile, item->lastline);
3207 } else {
3208 printf(" ACTIVE item, last used at %s, line %d",
3209 item->lastfile, item->lastline);
3210 switch(item->el_flags & NGQF_TYPE) {
3211 case NGQF_DATA:
3212 printf(" - [data]\n");
3213 break;
3214 case NGQF_MESG:
3215 printf(" - retaddr[%d]:\n", _NGI_RETADDR(item));
3216 break;
3217 case NGQF_FN:
3218 printf(" - fn@%p (%p, %p, %p, %d (%x))\n",
3219 item->body.fn.fn_fn,
3220 NGI_NODE(item),
3221 NGI_HOOK(item),
3222 item->body.fn.fn_arg1,
3223 item->body.fn.fn_arg2,
3224 item->body.fn.fn_arg2);
3225 break;
3226 case NGQF_UNDEF:
3227 printf(" - UNDEFINED!\n");
3228 }
3229 }
3230 if (line) {
3231 printf(" problem discovered at file %s, line %d\n", file, line);
3232 if (NGI_NODE(item)) {
3233 printf("node %p ([%x])\n",
3234 NGI_NODE(item), ng_node2ID(NGI_NODE(item)));
3235 }
3236 }
3237 }
3238
3239 static void
3240 ng_dumpitems(void)
3241 {
3242 item_p item;
3243 int i = 1;
3244 TAILQ_FOREACH(item, &ng_itemlist, all) {
3245 printf("[%d] ", i++);
3246 dumpitem(item, NULL, 0);
3247 }
3248 }
3249
3250 static void
3251 ng_dumpnodes(void)
3252 {
3253 node_p node;
3254 int i = 1;
3255 SLIST_FOREACH(node, &ng_allnodes, nd_all) {
3256 printf("[%d] ", i++);
3257 dumpnode(node, NULL, 0);
3258 }
3259 }
3260
3261 static void
3262 ng_dumphooks(void)
3263 {
3264 hook_p hook;
3265 int i = 1;
3266 SLIST_FOREACH(hook, &ng_allhooks, hk_all) {
3267 printf("[%d] ", i++);
3268 dumphook(hook, NULL, 0);
3269 }
3270 }
3271
3272 static int
3273 sysctl_debug_ng_dump_items(SYSCTL_HANDLER_ARGS)
3274 {
3275 int error;
3276 int val;
3277 int i;
3278
3279 val = allocated;
3280 i = 1;
3281 error = sysctl_handle_int(oidp, &val, sizeof(int), req);
3282 if (error != 0 || req->newptr == NULL)
3283 return (error);
3284 if (val == 42) {
3285 ng_dumpitems();
3286 ng_dumpnodes();
3287 ng_dumphooks();
3288 }
3289 return (0);
3290 }
3291
3292 SYSCTL_PROC(_debug, OID_AUTO, ng_dump_items, CTLTYPE_INT | CTLFLAG_RW,
3293 0, sizeof(int), sysctl_debug_ng_dump_items, "I", "Number of allocated items");
3294 #endif /* NETGRAPH_DEBUG */
3295
3296
3297 /***********************************************************************
3298 * Worklist routines
3299 **********************************************************************/
3300 /* NETISR thread enters here */
3301 /*
3302 * Pick a node off the list of nodes with work,
3303 * try get an item to process off it.
3304 * If there are no more, remove the node from the list.
3305 */
3306 static void
3307 ngintr(void)
3308 {
3309 item_p item;
3310 node_p node = NULL;
3311
3312 for (;;) {
3313 mtx_lock_spin(&ng_worklist_mtx);
3314 node = TAILQ_FIRST(&ng_worklist);
3315 if (!node) {
3316 mtx_unlock_spin(&ng_worklist_mtx);
3317 break;
3318 }
3319 node->nd_flags &= ~NG_WORKQ;
3320 TAILQ_REMOVE(&ng_worklist, node, nd_work);
3321 mtx_unlock_spin(&ng_worklist_mtx);
3322 /*
3323 * We have the node. We also take over the reference
3324 * that the list had on it.
3325 * Now process as much as you can, until it won't
3326 * let you have another item off the queue.
3327 * All this time, keep the reference
3328 * that lets us be sure that the node still exists.
3329 * Let the reference go at the last minute.
3330 * ng_dequeue will put us back on the worklist
3331 * if there is more too do. This may be of use if there
3332 * are Multiple Processors and multiple Net threads in the
3333 * future.
3334 */
3335 for (;;) {
3336 mtx_lock_spin(&node->nd_input_queue.q_mtx);
3337 item = ng_dequeue(&node->nd_input_queue);
3338 if (item == NULL) {
3339 mtx_unlock_spin(&node->nd_input_queue.q_mtx);
3340 break; /* go look for another node */
3341 } else {
3342 mtx_unlock_spin(&node->nd_input_queue.q_mtx);
3343 NGI_GET_NODE(item, node); /* zaps stored node */
3344 ng_apply_item(node, item);
3345 NG_NODE_UNREF(node);
3346 }
3347 }
3348 NG_NODE_UNREF(node);
3349 }
3350 }
3351
3352 static void
3353 ng_worklist_remove(node_p node)
3354 {
3355 mtx_lock_spin(&ng_worklist_mtx);
3356 if (node->nd_flags & NG_WORKQ) {
3357 node->nd_flags &= ~NG_WORKQ;
3358 TAILQ_REMOVE(&ng_worklist, node, nd_work);
3359 mtx_unlock_spin(&ng_worklist_mtx);
3360 NG_NODE_UNREF(node);
3361 } else {
3362 mtx_unlock_spin(&ng_worklist_mtx);
3363 }
3364 }
3365
3366 /*
3367 * XXX
3368 * It's posible that a debugging NG_NODE_REF may need
3369 * to be outside the mutex zone
3370 */
3371 static void
3372 ng_setisr(node_p node)
3373 {
3374 mtx_lock_spin(&ng_worklist_mtx);
3375 if ((node->nd_flags & NG_WORKQ) == 0) {
3376 /*
3377 * If we are not already on the work queue,
3378 * then put us on.
3379 */
3380 node->nd_flags |= NG_WORKQ;
3381 TAILQ_INSERT_TAIL(&ng_worklist, node, nd_work);
3382 NG_NODE_REF(node); /* XXX fafe in mutex? */
3383 }
3384 mtx_unlock_spin(&ng_worklist_mtx);
3385 schednetisr(NETISR_NETGRAPH);
3386 }
3387
3388
3389 /***********************************************************************
3390 * Externally useable functions to set up a queue item ready for sending
3391 ***********************************************************************/
3392
3393 #ifdef NETGRAPH_DEBUG
3394 #define ITEM_DEBUG_CHECKS \
3395 do { \
3396 if (NGI_NODE(item) ) { \
3397 printf("item already has node"); \
3398 Debugger("has node"); \
3399 NGI_CLR_NODE(item); \
3400 } \
3401 if (NGI_HOOK(item) ) { \
3402 printf("item already has hook"); \
3403 Debugger("has hook"); \
3404 NGI_CLR_HOOK(item); \
3405 } \
3406 } while (0)
3407 #else
3408 #define ITEM_DEBUG_CHECKS
3409 #endif
3410
3411 /*
3412 * Put elements into the item.
3413 * Hook and node references will be removed when the item is dequeued.
3414 * (or equivalent)
3415 * (XXX) Unsafe because no reference held by peer on remote node.
3416 * remote node might go away in this timescale.
3417 * We know the hooks can't go away because that would require getting
3418 * a writer item on both nodes and we must have at least a reader
3419 * here to eb able to do this.
3420 * Note that the hook loaded is the REMOTE hook.
3421 *
3422 * This is possibly in the critical path for new data.
3423 */
3424 item_p
3425 ng_package_data(struct mbuf *m, meta_p meta)
3426 {
3427 item_p item;
3428
3429 if ((item = ng_getqblk()) == NULL) {
3430 NG_FREE_M(m);
3431 NG_FREE_META(meta);
3432 return (NULL);
3433 }
3434 ITEM_DEBUG_CHECKS;
3435 item->el_flags = NGQF_DATA;
3436 item->el_next = NULL;
3437 NGI_M(item) = m;
3438 NGI_META(item) = meta;
3439 return (item);
3440 }
3441
3442 /*
3443 * Allocate a queue item and put items into it..
3444 * Evaluate the address as this will be needed to queue it and
3445 * to work out what some of the fields should be.
3446 * Hook and node references will be removed when the item is dequeued.
3447 * (or equivalent)
3448 */
3449 item_p
3450 ng_package_msg(struct ng_mesg *msg)
3451 {
3452 item_p item;
3453
3454 if ((item = ng_getqblk()) == NULL) {
3455 NG_FREE_MSG(msg);
3456 return (NULL);
3457 }
3458 ITEM_DEBUG_CHECKS;
3459 item->el_flags = NGQF_MESG;
3460 item->el_next = NULL;
3461 /*
3462 * Set the current lasthook into the queue item
3463 */
3464 NGI_MSG(item) = msg;
3465 NGI_RETADDR(item) = 0;
3466 return (item);
3467 }
3468
3469
3470
3471 #define SET_RETADDR(item, here, retaddr) \
3472 do { /* Data or fn items don't have retaddrs */ \
3473 if ((item->el_flags & NGQF_TYPE) == NGQF_MESG) { \
3474 if (retaddr) { \
3475 NGI_RETADDR(item) = retaddr; \
3476 } else { \
3477 /* \
3478 * The old return address should be ok. \
3479 * If there isn't one, use the address \
3480 * here. \
3481 */ \
3482 if (NGI_RETADDR(item) == 0) { \
3483 NGI_RETADDR(item) \
3484 = ng_node2ID(here); \
3485 } \
3486 } \
3487 } \
3488 } while (0)
3489
3490 int
3491 ng_address_hook(node_p here, item_p item, hook_p hook, ng_ID_t retaddr)
3492 {
3493 hook_p peer;
3494 node_p peernode;
3495 ITEM_DEBUG_CHECKS;
3496 /*
3497 * Quick sanity check..
3498 * Since a hook holds a reference on it's node, once we know
3499 * that the peer is still connected (even if invalid,) we know
3500 * that the peer node is present, though maybe invalid.
3501 */
3502 if ((hook == NULL)
3503 || NG_HOOK_NOT_VALID(hook)
3504 || (NG_HOOK_PEER(hook) == NULL)
3505 || NG_HOOK_NOT_VALID(NG_HOOK_PEER(hook))
3506 || NG_NODE_NOT_VALID(NG_PEER_NODE(hook))) {
3507 NG_FREE_ITEM(item);
3508 TRAP_ERROR();
3509 return (ENETDOWN);
3510 }
3511
3512 /*
3513 * Transfer our interest to the other (peer) end.
3514 */
3515 peer = NG_HOOK_PEER(hook);
3516 NG_HOOK_REF(peer);
3517 NGI_SET_HOOK(item, peer);
3518 peernode = NG_PEER_NODE(hook);
3519 NG_NODE_REF(peernode);
3520 NGI_SET_NODE(item, peernode);
3521 SET_RETADDR(item, here, retaddr);
3522 return (0);
3523 }
3524
3525 int
3526 ng_address_path(node_p here, item_p item, char *address, ng_ID_t retaddr)
3527 {
3528 node_p dest = NULL;
3529 hook_p hook = NULL;
3530 int error;
3531
3532 ITEM_DEBUG_CHECKS;
3533 /*
3534 * Note that ng_path2noderef increments the reference count
3535 * on the node for us if it finds one. So we don't have to.
3536 */
3537 error = ng_path2noderef(here, address, &dest, &hook);
3538 if (error) {
3539 NG_FREE_ITEM(item);
3540 return (error);
3541 }
3542 NGI_SET_NODE(item, dest);
3543 if ( hook) {
3544 NG_HOOK_REF(hook); /* don't let it go while on the queue */
3545 NGI_SET_HOOK(item, hook);
3546 }
3547 SET_RETADDR(item, here, retaddr);
3548 return (0);
3549 }
3550
3551 int
3552 ng_address_ID(node_p here, item_p item, ng_ID_t ID, ng_ID_t retaddr)
3553 {
3554 node_p dest;
3555
3556 ITEM_DEBUG_CHECKS;
3557 /*
3558 * Find the target node.
3559 */
3560 dest = ng_ID2noderef(ID); /* GETS REFERENCE! */
3561 if (dest == NULL) {
3562 NG_FREE_ITEM(item);
3563 TRAP_ERROR();
3564 return(EINVAL);
3565 }
3566 /* Fill out the contents */
3567 item->el_flags = NGQF_MESG;
3568 item->el_next = NULL;
3569 NGI_SET_NODE(item, dest);
3570 NGI_CLR_HOOK(item);
3571 SET_RETADDR(item, here, retaddr);
3572 return (0);
3573 }
3574
3575 /*
3576 * special case to send a message to self (e.g. destroy node)
3577 * Possibly indicate an arrival hook too.
3578 * Useful for removing that hook :-)
3579 */
3580 item_p
3581 ng_package_msg_self(node_p here, hook_p hook, struct ng_mesg *msg)
3582 {
3583 item_p item;
3584
3585 /*
3586 * Find the target node.
3587 * If there is a HOOK argument, then use that in preference
3588 * to the address.
3589 */
3590 if ((item = ng_getqblk()) == NULL) {
3591 NG_FREE_MSG(msg);
3592 return (NULL);
3593 }
3594
3595 /* Fill out the contents */
3596 item->el_flags = NGQF_MESG;
3597 item->el_next = NULL;
3598 NG_NODE_REF(here);
3599 NGI_SET_NODE(item, here);
3600 if (hook) {
3601 NG_HOOK_REF(hook);
3602 NGI_SET_HOOK(item, hook);
3603 }
3604 NGI_MSG(item) = msg;
3605 NGI_RETADDR(item) = ng_node2ID(here);
3606 return (item);
3607 }
3608
3609 int
3610 ng_send_fn(node_p node, hook_p hook, ng_item_fn *fn, void * arg1, int arg2)
3611 {
3612 item_p item;
3613
3614 if ((item = ng_getqblk()) == NULL) {
3615 return (ENOMEM);
3616 }
3617 item->el_flags = NGQF_FN | NGQF_WRITER;
3618 NG_NODE_REF(node); /* and one for the item */
3619 NGI_SET_NODE(item, node);
3620 if (hook) {
3621 NG_HOOK_REF(hook);
3622 NGI_SET_HOOK(item, hook);
3623 }
3624 NGI_FN(item) = fn;
3625 NGI_ARG1(item) = arg1;
3626 NGI_ARG2(item) = arg2;
3627 return(ng_snd_item(item, 0));
3628 }
3629
3630 /*
3631 * Official timeout routines for Netgraph nodes.
3632 */
3633 static void
3634 ng_timeout_trapoline(void *arg)
3635 {
3636 item_p item = arg;
3637
3638 ng_snd_item(item, 0);
3639 }
3640
3641
3642 struct callout_handle
3643 ng_timeout(node_p node, hook_p hook, int ticks,
3644 ng_item_fn *fn, void * arg1, int arg2)
3645 {
3646 item_p item;
3647
3648 if ((item = ng_getqblk()) == NULL) {
3649 struct callout_handle handle;
3650 handle.callout = NULL;
3651 return (handle);
3652 }
3653 item->el_flags = NGQF_FN | NGQF_WRITER;
3654 NG_NODE_REF(node); /* and one for the item */
3655 NGI_SET_NODE(item, node);
3656 if (hook) {
3657 NG_HOOK_REF(hook);
3658 NGI_SET_HOOK(item, hook);
3659 }
3660 NGI_FN(item) = fn;
3661 NGI_ARG1(item) = arg1;
3662 NGI_ARG2(item) = arg2;
3663 return (timeout(&ng_timeout_trapoline, item, ticks));
3664 }
3665
3666 /* A special modified version of untimeout() */
3667 int
3668 ng_untimeout(struct callout_handle handle, node_p node)
3669 {
3670 item_p item;
3671
3672 if (handle.callout == NULL)
3673 return (0);
3674 mtx_lock_spin(&callout_lock);
3675 item = handle.callout->c_arg; /* should be an official way to do this */
3676 if ((handle.callout->c_func == &ng_timeout_trapoline) &&
3677 (NGI_NODE(item) == node) &&
3678 (callout_stop(handle.callout))) {
3679 /*
3680 * We successfully removed it from the queue before it ran
3681 * So now we need to unreference everything that was
3682 * given extra references. (NG_FREE_ITEM does this).
3683 */
3684 mtx_unlock_spin(&callout_lock);
3685 NG_FREE_ITEM(item);
3686 return (1);
3687 }
3688 mtx_unlock_spin(&callout_lock);
3689 return (0);
3690 }
3691
3692 /*
3693 * Set the address, if none given, give the node here.
3694 */
3695 void
3696 ng_replace_retaddr(node_p here, item_p item, ng_ID_t retaddr)
3697 {
3698 if (retaddr) {
3699 NGI_RETADDR(item) = retaddr;
3700 } else {
3701 /*
3702 * The old return address should be ok.
3703 * If there isn't one, use the address here.
3704 */
3705 NGI_RETADDR(item) = ng_node2ID(here);
3706 }
3707 }
3708
3709 #define TESTING
3710 #ifdef TESTING
3711 /* just test all the macros */
3712 void
3713 ng_macro_test(item_p item);
3714 void
3715 ng_macro_test(item_p item)
3716 {
3717 node_p node = NULL;
3718 hook_p hook = NULL;
3719 struct mbuf *m;
3720 meta_p meta;
3721 struct ng_mesg *msg;
3722 ng_ID_t retaddr;
3723 int error;
3724
3725 NGI_GET_M(item, m);
3726 NGI_GET_META(item, meta);
3727 NGI_GET_MSG(item, msg);
3728 retaddr = NGI_RETADDR(item);
3729 NG_SEND_DATA(error, hook, m, meta);
3730 NG_SEND_DATA_ONLY(error, hook, m);
3731 NG_FWD_NEW_DATA(error, item, hook, m);
3732 NG_FWD_ITEM_HOOK(error, item, hook);
3733 NG_SEND_MSG_HOOK(error, node, msg, hook, retaddr);
3734 NG_SEND_MSG_ID(error, node, msg, retaddr, retaddr);
3735 NG_SEND_MSG_PATH(error, node, msg, ".:", retaddr);
3736 NG_FWD_MSG_HOOK(error, node, item, hook, retaddr);
3737 }
3738 #endif /* TESTING */
3739
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