1 /*
2 * ng_socket.c
3 */
4
5 /*-
6 * Copyright (c) 1996-1999 Whistle Communications, Inc.
7 * All rights reserved.
8 *
9 * Subject to the following obligations and disclaimer of warranty, use and
10 * redistribution of this software, in source or object code forms, with or
11 * without modifications are expressly permitted by Whistle Communications;
12 * provided, however, that:
13 * 1. Any and all reproductions of the source or object code must include the
14 * copyright notice above and the following disclaimer of warranties; and
15 * 2. No rights are granted, in any manner or form, to use Whistle
16 * Communications, Inc. trademarks, including the mark "WHISTLE
17 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as
18 * such appears in the above copyright notice or in the software.
19 *
20 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
21 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
22 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
23 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
25 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
26 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
27 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
28 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
29 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
30 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
31 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
32 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
36 * OF SUCH DAMAGE.
37 *
38 * Author: Julian Elischer <julian@freebsd.org>
39 * $Whistle: ng_socket.c,v 1.28 1999/11/01 09:24:52 julian Exp $
40 */
41
42 /*
43 * Netgraph socket nodes
44 *
45 * There are two types of netgraph sockets, control and data.
46 * Control sockets have a netgraph node, but data sockets are
47 * parasitic on control sockets, and have no node of their own.
48 */
49
50 #include <sys/param.h>
51 #include <sys/domain.h>
52 #include <sys/hash.h>
53 #include <sys/kernel.h>
54 #include <sys/linker.h>
55 #include <sys/lock.h>
56 #include <sys/malloc.h>
57 #include <sys/mbuf.h>
58 #include <sys/mutex.h>
59 #include <sys/proc.h>
60 #include <sys/epoch.h>
61 #include <sys/priv.h>
62 #include <sys/protosw.h>
63 #include <sys/queue.h>
64 #include <sys/socket.h>
65 #include <sys/socketvar.h>
66 #include <sys/syscallsubr.h>
67 #include <sys/sysctl.h>
68
69 #include <net/vnet.h>
70
71 #include <netgraph/ng_message.h>
72 #include <netgraph/netgraph.h>
73 #include <netgraph/ng_socketvar.h>
74 #include <netgraph/ng_socket.h>
75
76 #ifdef NG_SEPARATE_MALLOC
77 static MALLOC_DEFINE(M_NETGRAPH_PATH, "netgraph_path", "netgraph path info");
78 static MALLOC_DEFINE(M_NETGRAPH_SOCK, "netgraph_sock", "netgraph socket info");
79 #else
80 #define M_NETGRAPH_PATH M_NETGRAPH
81 #define M_NETGRAPH_SOCK M_NETGRAPH
82 #endif
83
84 /*
85 * It's Ascii-art time!
86 * +-------------+ +-------------+
87 * |socket (ctl)| |socket (data)|
88 * +-------------+ +-------------+
89 * ^ ^
90 * | |
91 * v v
92 * +-----------+ +-----------+
93 * |pcb (ctl)| |pcb (data)|
94 * +-----------+ +-----------+
95 * ^ ^
96 * | |
97 * v v
98 * +--------------------------+
99 * | Socket type private |
100 * | data |
101 * +--------------------------+
102 * ^
103 * |
104 * v
105 * +----------------+
106 * | struct ng_node |
107 * +----------------+
108 */
109
110 /* Netgraph node methods */
111 static ng_constructor_t ngs_constructor;
112 static ng_rcvmsg_t ngs_rcvmsg;
113 static ng_shutdown_t ngs_shutdown;
114 static ng_newhook_t ngs_newhook;
115 static ng_connect_t ngs_connect;
116 static ng_findhook_t ngs_findhook;
117 static ng_rcvdata_t ngs_rcvdata;
118 static ng_disconnect_t ngs_disconnect;
119
120 /* Internal methods */
121 static int ng_attach_common(struct socket *, int, struct thread *);
122 static void ng_detach_common(struct socket *);
123 static void ng_socket_free_priv(struct ngsock *priv);
124 static int ngs_mod_event(module_t mod, int event, void *data);
125 static void ng_socket_item_applied(void *context, int error);
126
127 /* Netgraph type descriptor */
128 static struct ng_type typestruct = {
129 .version = NG_ABI_VERSION,
130 .name = NG_SOCKET_NODE_TYPE,
131 .mod_event = ngs_mod_event,
132 .constructor = ngs_constructor,
133 .rcvmsg = ngs_rcvmsg,
134 .shutdown = ngs_shutdown,
135 .newhook = ngs_newhook,
136 .connect = ngs_connect,
137 .findhook = ngs_findhook,
138 .rcvdata = ngs_rcvdata,
139 .disconnect = ngs_disconnect,
140 };
141 NETGRAPH_INIT_ORDERED(socket, &typestruct, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
142
143 /* Buffer space */
144 static u_long ngpdg_sendspace = 20 * 1024; /* really max datagram size */
145 SYSCTL_ULONG(_net_graph, OID_AUTO, maxdgram, CTLFLAG_RW,
146 &ngpdg_sendspace , 0, "Maximum outgoing Netgraph datagram size");
147 static u_long ngpdg_recvspace = 20 * 1024;
148 SYSCTL_ULONG(_net_graph, OID_AUTO, recvspace, CTLFLAG_RW,
149 &ngpdg_recvspace , 0, "Maximum space for incoming Netgraph datagrams");
150
151 /* List of all sockets (for netstat -f netgraph) */
152 static LIST_HEAD(, ngpcb) ngsocklist;
153
154 static struct mtx ngsocketlist_mtx;
155
156 /* If getting unexplained errors returned, set this to "kdb_enter("X"); */
157 #ifndef TRAP_ERROR
158 #define TRAP_ERROR
159 #endif
160
161 struct hookpriv {
162 LIST_ENTRY(hookpriv) next;
163 hook_p hook;
164 };
165 LIST_HEAD(ngshash, hookpriv);
166
167 /* Per-node private data */
168 struct ngsock {
169 struct ng_node *node; /* the associated netgraph node */
170 struct ngpcb *datasock; /* optional data socket */
171 struct ngpcb *ctlsock; /* optional control socket */
172 struct ngshash *hash; /* hash for hook names */
173 u_long hmask; /* hash mask */
174 int flags;
175 int refs;
176 struct mtx mtx; /* mtx to wait on */
177 int error; /* place to store error */
178 };
179
180 #define NGS_FLAG_NOLINGER 1 /* close with last hook */
181
182 /***************************************************************
183 Control sockets
184 ***************************************************************/
185
186 static int
ngc_send(struct socket * so,int flags,struct mbuf * m,struct sockaddr * addr,struct mbuf * control,struct thread * td)187 ngc_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
188 struct mbuf *control, struct thread *td)
189 {
190 struct ngpcb *const pcbp = so->so_pcb;
191 struct ngsock *const priv = NG_NODE_PRIVATE(pcbp->sockdata->node);
192 struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
193 struct ng_mesg *msg;
194 struct mbuf *m0;
195 item_p item;
196 char *path = NULL;
197 int len, error = 0;
198 struct ng_apply_info apply;
199
200 if (control) {
201 error = EINVAL;
202 goto release;
203 }
204
205 /* Require destination as there may be >= 1 hooks on this node. */
206 if (addr == NULL) {
207 error = EDESTADDRREQ;
208 goto release;
209 }
210
211 if (sap->sg_len > NG_NODESIZ + offsetof(struct sockaddr_ng, sg_data)) {
212 error = EINVAL;
213 goto release;
214 }
215
216 /*
217 * Allocate an expendable buffer for the path, chop off
218 * the sockaddr header, and make sure it's NUL terminated.
219 */
220 len = sap->sg_len - offsetof(struct sockaddr_ng, sg_data);
221 path = malloc(len + 1, M_NETGRAPH_PATH, M_WAITOK);
222 bcopy(sap->sg_data, path, len);
223 path[len] = '\0';
224
225 /*
226 * Move the actual message out of mbufs into a linear buffer.
227 * Start by adding up the size of the data. (could use mh_len?)
228 */
229 for (len = 0, m0 = m; m0 != NULL; m0 = m0->m_next)
230 len += m0->m_len;
231
232 /*
233 * Move the data into a linear buffer as well.
234 * Messages are not delivered in mbufs.
235 */
236 msg = malloc(len + 1, M_NETGRAPH_MSG, M_WAITOK);
237 m_copydata(m, 0, len, (char *)msg);
238
239 if (msg->header.version != NG_VERSION) {
240 free(msg, M_NETGRAPH_MSG);
241 error = EINVAL;
242 goto release;
243 }
244
245 /*
246 * Hack alert!
247 * We look into the message and if it mkpeers a node of unknown type, we
248 * try to load it. We need to do this now, in syscall thread, because if
249 * message gets queued and applied later we will get panic.
250 */
251 if (msg->header.typecookie == NGM_GENERIC_COOKIE &&
252 msg->header.cmd == NGM_MKPEER) {
253 struct ngm_mkpeer *const mkp = (struct ngm_mkpeer *) msg->data;
254
255 if (ng_findtype(mkp->type) == NULL) {
256 char filename[NG_TYPESIZ + 3];
257 int fileid;
258 bool loaded;
259
260 /* Not found, try to load it as a loadable module. */
261 snprintf(filename, sizeof(filename), "ng_%s",
262 mkp->type);
263 error = kern_kldload(curthread, filename, &fileid);
264 loaded = (error == 0);
265 if (error == EEXIST)
266 error = 0;
267 if (error != 0) {
268 free(msg, M_NETGRAPH_MSG);
269 goto release;
270 }
271
272 /* See if type has been loaded successfully. */
273 if (ng_findtype(mkp->type) == NULL) {
274 free(msg, M_NETGRAPH_MSG);
275 if (loaded)
276 (void)kern_kldunload(curthread, fileid,
277 LINKER_UNLOAD_NORMAL);
278 error = ENXIO;
279 goto release;
280 }
281 }
282 }
283
284 item = ng_package_msg(msg, NG_WAITOK);
285 if ((error = ng_address_path((pcbp->sockdata->node), item, path, 0))
286 != 0) {
287 #ifdef TRACE_MESSAGES
288 printf("ng_address_path: errx=%d\n", error);
289 #endif
290 goto release;
291 }
292
293 #ifdef TRACE_MESSAGES
294 printf("[%x]:<---------[socket]: c=<%d>cmd=%x(%s) f=%x #%d (%s)\n",
295 item->el_dest->nd_ID,
296 msg->header.typecookie,
297 msg->header.cmd,
298 msg->header.cmdstr,
299 msg->header.flags,
300 msg->header.token,
301 item->el_dest->nd_type->name);
302 #endif
303 SAVE_LINE(item);
304 /*
305 * We do not want to return from syscall until the item
306 * is processed by destination node. We register callback
307 * on the item, which will update priv->error when item
308 * was applied.
309 * If ng_snd_item() has queued item, we sleep until
310 * callback wakes us up.
311 */
312 bzero(&apply, sizeof(apply));
313 apply.apply = ng_socket_item_applied;
314 apply.context = priv;
315 item->apply = &apply;
316 priv->error = -1;
317
318 error = ng_snd_item(item, 0);
319
320 mtx_lock(&priv->mtx);
321 if (priv->error == -1)
322 msleep(priv, &priv->mtx, 0, "ngsock", 0);
323 mtx_unlock(&priv->mtx);
324 KASSERT(priv->error != -1,
325 ("ng_socket: priv->error wasn't updated"));
326 error = priv->error;
327
328 release:
329 if (path != NULL)
330 free(path, M_NETGRAPH_PATH);
331 if (control != NULL)
332 m_freem(control);
333 if (m != NULL)
334 m_freem(m);
335 return (error);
336 }
337
338 /***************************************************************
339 Data sockets
340 ***************************************************************/
341
342 static int
ngd_send(struct socket * so,int flags,struct mbuf * m,struct sockaddr * addr,struct mbuf * control,struct thread * td)343 ngd_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
344 struct mbuf *control, struct thread *td)
345 {
346 struct epoch_tracker et;
347 struct ngpcb *const pcbp = so->so_pcb;
348 struct sockaddr_ng *const sap = (struct sockaddr_ng *) addr;
349 int len, error;
350 hook_p hook = NULL;
351 item_p item;
352 char hookname[NG_HOOKSIZ];
353
354 if ((pcbp == NULL) || (control != NULL)) {
355 error = EINVAL;
356 goto release;
357 }
358 if (pcbp->sockdata == NULL) {
359 error = ENOTCONN;
360 goto release;
361 }
362
363 if (sap == NULL) {
364 len = 0; /* Make compiler happy. */
365 } else {
366 if (sap->sg_len > NG_NODESIZ +
367 offsetof(struct sockaddr_ng, sg_data)) {
368 error = EINVAL;
369 goto release;
370 }
371 len = sap->sg_len - offsetof(struct sockaddr_ng, sg_data);
372 }
373
374 /*
375 * If the user used any of these ways to not specify an address
376 * then handle specially.
377 */
378 if ((sap == NULL) || (len <= 0) || (*sap->sg_data == '\0')) {
379 if (NG_NODE_NUMHOOKS(pcbp->sockdata->node) != 1) {
380 error = EDESTADDRREQ;
381 goto release;
382 }
383 /*
384 * If exactly one hook exists, just use it.
385 * Special case to allow write(2) to work on an ng_socket.
386 */
387 hook = LIST_FIRST(&pcbp->sockdata->node->nd_hooks);
388 } else {
389 if (len >= NG_HOOKSIZ) {
390 error = EINVAL;
391 goto release;
392 }
393
394 /*
395 * chop off the sockaddr header, and make sure it's NUL
396 * terminated
397 */
398 bcopy(sap->sg_data, hookname, len);
399 hookname[len] = '\0';
400
401 /* Find the correct hook from 'hookname' */
402 hook = ng_findhook(pcbp->sockdata->node, hookname);
403 if (hook == NULL) {
404 error = EHOSTUNREACH;
405 goto release;
406 }
407 }
408
409 /* Send data. */
410 item = ng_package_data(m, NG_WAITOK);
411 m = NULL;
412 NET_EPOCH_ENTER(et);
413 NG_FWD_ITEM_HOOK(error, item, hook);
414 NET_EPOCH_EXIT(et);
415
416 release:
417 if (control != NULL)
418 m_freem(control);
419 if (m != NULL)
420 m_freem(m);
421 return (error);
422 }
423
424 /*
425 * Used for both data and control sockets
426 */
427 static int
ng_getsockaddr(struct socket * so,struct sockaddr * sa)428 ng_getsockaddr(struct socket *so, struct sockaddr *sa)
429 {
430 struct sockaddr_ng *sg = (struct sockaddr_ng *)sa;
431 struct ngpcb *pcbp = so->so_pcb;
432 int error = 0;
433
434 if (pcbp->sockdata == NULL)
435 /* XXXGL: can this still happen? */
436 return (EINVAL);
437
438 *sg = (struct sockaddr_ng ){
439 .sg_len = sizeof(struct sockaddr_ng),
440 .sg_family = AF_NETGRAPH,
441 };
442
443 mtx_lock(&pcbp->sockdata->mtx);
444 if (pcbp->sockdata->node != NULL) {
445 node_p node = pcbp->sockdata->node;
446
447 if (NG_NODE_HAS_NAME(node))
448 bcopy(NG_NODE_NAME(node), sg->sg_data,
449 strlen(NG_NODE_NAME(node)));
450 else
451 snprintf(sg->sg_data, sizeof(sg->sg_data), "[%x]",
452 ng_node2ID(node));
453 } else
454 error = EINVAL;
455 mtx_unlock(&pcbp->sockdata->mtx);
456
457 return (error);
458 }
459
460 /*
461 * Attach a socket to it's protocol specific partner.
462 * For a control socket, actually create a netgraph node and attach
463 * to it as well.
464 */
465
466 static int
ngc_attach(struct socket * so,int type,struct thread * td)467 ngc_attach(struct socket *so, int type, struct thread *td)
468 {
469 struct ngsock *priv;
470 struct ngpcb *pcbp;
471 node_p node;
472 int error;
473
474 if ((error = priv_check(td, PRIV_NETGRAPH_CONTROL)) != 0)
475 return (error);
476
477 /* Setup protocol control block */
478 if ((error = ng_attach_common(so, type, td)) != 0)
479 return (error);
480 pcbp = so->so_pcb;
481
482 /* Make the generic node components */
483 if ((error = ng_make_node_common(&typestruct, &node)) != 0) {
484 ng_detach_common(so);
485 return (error);
486 }
487
488 /*
489 * Allocate node private info and hash. We start
490 * with 16 hash entries, however we may grow later
491 * in ngs_newhook(). We can't predict how much hooks
492 * does this node plan to have.
493 */
494 priv = malloc(sizeof(*priv), M_NETGRAPH_SOCK, M_WAITOK | M_ZERO);
495 priv->hash = hashinit(16, M_NETGRAPH_SOCK, &priv->hmask);
496
497 /* Initialize mutex. */
498 mtx_init(&priv->mtx, "ng_socket", NULL, MTX_DEF);
499
500 /* Link the pcb the private data. */
501 priv->ctlsock = pcbp;
502 pcbp->sockdata = priv;
503 priv->refs++;
504 priv->node = node;
505 pcbp->node_id = node->nd_ID; /* hint for netstat(1) */
506
507 /* Link the node and the private data. */
508 NG_NODE_SET_PRIVATE(priv->node, priv);
509 priv->refs++;
510
511 return (0);
512 }
513
514 /*
515 * Set up a socket protocol control block.
516 * This code is shared between control and data sockets.
517 */
518 static int
ng_attach_common(struct socket * so,int type,struct thread * td)519 ng_attach_common(struct socket *so, int type, struct thread *td)
520 {
521 struct ngpcb *pcbp;
522 int error;
523
524 /* Standard socket setup stuff. */
525 error = soreserve(so, ngpdg_sendspace, ngpdg_recvspace);
526 if (error)
527 return (error);
528
529 /* Allocate the pcb. */
530 pcbp = malloc(sizeof(struct ngpcb), M_PCB, M_WAITOK | M_ZERO);
531 pcbp->type = type;
532
533 /* Link the pcb and the socket. */
534 so->so_pcb = (caddr_t)pcbp;
535 pcbp->ng_socket = so;
536
537 /* Add the socket to linked list */
538 mtx_lock(&ngsocketlist_mtx);
539 LIST_INSERT_HEAD(&ngsocklist, pcbp, socks);
540 mtx_unlock(&ngsocketlist_mtx);
541 return (0);
542 }
543
544 /*
545 * Disassociate the socket from it's protocol specific
546 * partner. If it's attached to a node's private data structure,
547 * then unlink from that too. If we were the last socket attached to it,
548 * then shut down the entire node. Shared code for control and data sockets.
549 */
550 static void
ng_detach_common(struct socket * so)551 ng_detach_common(struct socket *so)
552 {
553 struct ngpcb *pcbp = so->so_pcb;
554 struct ngsock *priv = pcbp->sockdata;
555
556 if (priv != NULL) {
557 mtx_lock(&priv->mtx);
558
559 switch (pcbp->type) {
560 case NG_CONTROL:
561 priv->ctlsock = NULL;
562 break;
563 case NG_DATA:
564 priv->datasock = NULL;
565 break;
566 default:
567 panic("%s", __func__);
568 }
569 pcbp->sockdata = NULL;
570 pcbp->node_id = 0;
571
572 ng_socket_free_priv(priv);
573 }
574
575 pcbp->ng_socket->so_pcb = NULL;
576 mtx_lock(&ngsocketlist_mtx);
577 LIST_REMOVE(pcbp, socks);
578 mtx_unlock(&ngsocketlist_mtx);
579 free(pcbp, M_PCB);
580 }
581
582 /*
583 * Remove a reference from node private data.
584 */
585 static void
ng_socket_free_priv(struct ngsock * priv)586 ng_socket_free_priv(struct ngsock *priv)
587 {
588 mtx_assert(&priv->mtx, MA_OWNED);
589
590 priv->refs--;
591
592 if (priv->refs == 0) {
593 mtx_destroy(&priv->mtx);
594 hashdestroy(priv->hash, M_NETGRAPH_SOCK, priv->hmask);
595 free(priv, M_NETGRAPH_SOCK);
596 return;
597 }
598
599 if ((priv->refs == 1) && (priv->node != NULL)) {
600 node_p node = priv->node;
601
602 priv->node = NULL;
603 mtx_unlock(&priv->mtx);
604 ng_rmnode_self(node);
605 } else
606 mtx_unlock(&priv->mtx);
607 }
608
609 /*
610 * Connect the data socket to a named control socket node.
611 */
612 static int
ngd_connect(struct socket * so,struct sockaddr * nam,struct thread * td)613 ngd_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
614 {
615 struct ngpcb *const pcbp = so->so_pcb;
616 struct sockaddr_ng *sap;
617 node_p farnode;
618 struct ngsock *priv;
619 int error;
620 item_p item;
621
622 /* If we are already connected, don't do it again. */
623 if (pcbp->sockdata != NULL)
624 return (EISCONN);
625
626 /*
627 * Find the target (victim) and check it doesn't already have
628 * a data socket. Also check it is a 'socket' type node.
629 * Use ng_package_data() and ng_address_path() to do this.
630 */
631
632 sap = (struct sockaddr_ng *) nam;
633 /* The item will hold the node reference. */
634 item = ng_package_data(NULL, NG_WAITOK);
635
636 if ((error = ng_address_path(NULL, item, sap->sg_data, 0)))
637 return (error); /* item is freed on failure */
638
639 /*
640 * Extract node from item and free item. Remember we now have
641 * a reference on the node. The item holds it for us.
642 * when we free the item we release the reference.
643 */
644 farnode = item->el_dest; /* shortcut */
645 if (strcmp(farnode->nd_type->name, NG_SOCKET_NODE_TYPE) != 0) {
646 NG_FREE_ITEM(item); /* drop the reference to the node */
647 return (EINVAL);
648 }
649 priv = NG_NODE_PRIVATE(farnode);
650 if (priv->datasock != NULL) {
651 NG_FREE_ITEM(item); /* drop the reference to the node */
652 return (EADDRINUSE);
653 }
654
655 /*
656 * Link the PCB and the private data struct. and note the extra
657 * reference. Drop the extra reference on the node.
658 */
659 mtx_lock(&priv->mtx);
660 priv->datasock = pcbp;
661 pcbp->sockdata = priv;
662 pcbp->node_id = priv->node->nd_ID; /* hint for netstat(1) */
663 priv->refs++;
664 mtx_unlock(&priv->mtx);
665 NG_FREE_ITEM(item); /* drop the reference to the node */
666 return (0);
667 }
668
669 /*
670 * Binding a socket means giving the corresponding node a name
671 */
672 static int
ngc_bind(struct socket * so,struct sockaddr * nam,struct thread * td)673 ngc_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
674 {
675 struct ngpcb *const pcbp = so->so_pcb;
676 struct ngsock *const priv = pcbp->sockdata;
677 struct sockaddr_ng *const sap = (struct sockaddr_ng *) nam;
678
679 if (priv == NULL) {
680 TRAP_ERROR;
681 return (EINVAL);
682 }
683 if ((sap->sg_len < 4) || (sap->sg_len > (NG_NODESIZ + 2)) ||
684 (sap->sg_data[0] == '\0') ||
685 (sap->sg_data[sap->sg_len - 3] != '\0')) {
686 TRAP_ERROR;
687 return (EINVAL);
688 }
689 return (ng_name_node(priv->node, sap->sg_data));
690 }
691
692 /***************************************************************
693 Netgraph node
694 ***************************************************************/
695
696 /*
697 * You can only create new nodes from the socket end of things.
698 */
699 static int
ngs_constructor(node_p nodep)700 ngs_constructor(node_p nodep)
701 {
702 return (EINVAL);
703 }
704
705 static void
ngs_rehash(node_p node)706 ngs_rehash(node_p node)
707 {
708 struct ngsock *priv = NG_NODE_PRIVATE(node);
709 struct ngshash *new;
710 struct hookpriv *hp;
711 hook_p hook;
712 uint32_t h;
713 u_long hmask;
714
715 new = hashinit_flags((priv->hmask + 1) * 2, M_NETGRAPH_SOCK, &hmask,
716 HASH_NOWAIT);
717 if (new == NULL)
718 return;
719
720 LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
721 hp = NG_HOOK_PRIVATE(hook);
722 #ifdef INVARIANTS
723 LIST_REMOVE(hp, next);
724 #endif
725 h = hash32_str(NG_HOOK_NAME(hook), HASHINIT) & hmask;
726 LIST_INSERT_HEAD(&new[h], hp, next);
727 }
728
729 hashdestroy(priv->hash, M_NETGRAPH_SOCK, priv->hmask);
730 priv->hash = new;
731 priv->hmask = hmask;
732 }
733
734 /*
735 * We allow any hook to be connected to the node.
736 * There is no per-hook private information though.
737 */
738 static int
ngs_newhook(node_p node,hook_p hook,const char * name)739 ngs_newhook(node_p node, hook_p hook, const char *name)
740 {
741 struct ngsock *const priv = NG_NODE_PRIVATE(node);
742 struct hookpriv *hp;
743 uint32_t h;
744
745 hp = malloc(sizeof(*hp), M_NETGRAPH_SOCK, M_NOWAIT);
746 if (hp == NULL)
747 return (ENOMEM);
748 if (node->nd_numhooks * 2 > priv->hmask)
749 ngs_rehash(node);
750 hp->hook = hook;
751 h = hash32_str(name, HASHINIT) & priv->hmask;
752 LIST_INSERT_HEAD(&priv->hash[h], hp, next);
753 NG_HOOK_SET_PRIVATE(hook, hp);
754
755 return (0);
756 }
757
758 /*
759 * If only one hook, allow read(2) and write(2) to work.
760 */
761 static int
ngs_connect(hook_p hook)762 ngs_connect(hook_p hook)
763 {
764 node_p node = NG_HOOK_NODE(hook);
765 struct ngsock *priv = NG_NODE_PRIVATE(node);
766
767 if ((priv->datasock) && (priv->datasock->ng_socket)) {
768 if (NG_NODE_NUMHOOKS(node) == 1)
769 priv->datasock->ng_socket->so_state |= SS_ISCONNECTED;
770 else
771 priv->datasock->ng_socket->so_state &= ~SS_ISCONNECTED;
772 }
773 return (0);
774 }
775
776 /* Look up hook by name */
777 static hook_p
ngs_findhook(node_p node,const char * name)778 ngs_findhook(node_p node, const char *name)
779 {
780 struct ngsock *priv = NG_NODE_PRIVATE(node);
781 struct hookpriv *hp;
782 uint32_t h;
783
784 /*
785 * Microoptimisation for an ng_socket with
786 * a single hook, which is a common case.
787 */
788 if (node->nd_numhooks == 1) {
789 hook_p hook;
790
791 hook = LIST_FIRST(&node->nd_hooks);
792
793 if (strcmp(NG_HOOK_NAME(hook), name) == 0)
794 return (hook);
795 else
796 return (NULL);
797 }
798
799 h = hash32_str(name, HASHINIT) & priv->hmask;
800
801 LIST_FOREACH(hp, &priv->hash[h], next)
802 if (strcmp(NG_HOOK_NAME(hp->hook), name) == 0)
803 return (hp->hook);
804
805 return (NULL);
806 }
807
808 /*
809 * Incoming messages get passed up to the control socket.
810 * Unless they are for us specifically (socket_type)
811 */
812 static int
ngs_rcvmsg(node_p node,item_p item,hook_p lasthook)813 ngs_rcvmsg(node_p node, item_p item, hook_p lasthook)
814 {
815 struct ngsock *const priv = NG_NODE_PRIVATE(node);
816 struct ngpcb *pcbp;
817 struct socket *so;
818 struct sockaddr_ng addr;
819 struct ng_mesg *msg;
820 struct mbuf *m;
821 ng_ID_t retaddr = NGI_RETADDR(item);
822 int addrlen;
823 int error = 0;
824
825 NGI_GET_MSG(item, msg);
826 NG_FREE_ITEM(item);
827
828 /*
829 * Grab priv->mtx here to prevent destroying of control socket
830 * after checking that priv->ctlsock is not NULL.
831 */
832 mtx_lock(&priv->mtx);
833 pcbp = priv->ctlsock;
834
835 /*
836 * Only allow mesgs to be passed if we have the control socket.
837 * Data sockets can only support the generic messages.
838 */
839 if (pcbp == NULL) {
840 mtx_unlock(&priv->mtx);
841 TRAP_ERROR;
842 NG_FREE_MSG(msg);
843 return (EINVAL);
844 }
845 so = pcbp->ng_socket;
846 SOCKBUF_LOCK(&so->so_rcv);
847
848 /* As long as the race is handled, priv->mtx may be unlocked now. */
849 mtx_unlock(&priv->mtx);
850
851 #ifdef TRACE_MESSAGES
852 printf("[%x]:---------->[socket]: c=<%d>cmd=%x(%s) f=%x #%d\n",
853 retaddr,
854 msg->header.typecookie,
855 msg->header.cmd,
856 msg->header.cmdstr,
857 msg->header.flags,
858 msg->header.token);
859 #endif
860
861 if (msg->header.typecookie == NGM_SOCKET_COOKIE) {
862 switch (msg->header.cmd) {
863 case NGM_SOCK_CMD_NOLINGER:
864 priv->flags |= NGS_FLAG_NOLINGER;
865 break;
866 case NGM_SOCK_CMD_LINGER:
867 priv->flags &= ~NGS_FLAG_NOLINGER;
868 break;
869 default:
870 error = EINVAL; /* unknown command */
871 }
872 SOCKBUF_UNLOCK(&so->so_rcv);
873
874 /* Free the message and return. */
875 NG_FREE_MSG(msg);
876 return (error);
877 }
878
879 /* Get the return address into a sockaddr. */
880 bzero(&addr, sizeof(addr));
881 addr.sg_len = sizeof(addr);
882 addr.sg_family = AF_NETGRAPH;
883 addrlen = snprintf((char *)&addr.sg_data, sizeof(addr.sg_data),
884 "[%x]:", retaddr);
885 if (addrlen < 0 || addrlen > sizeof(addr.sg_data)) {
886 SOCKBUF_UNLOCK(&so->so_rcv);
887 printf("%s: snprintf([%x]) failed - %d\n", __func__, retaddr,
888 addrlen);
889 NG_FREE_MSG(msg);
890 return (EINVAL);
891 }
892
893 /* Copy the message itself into an mbuf chain. */
894 m = m_devget((caddr_t)msg, sizeof(struct ng_mesg) + msg->header.arglen,
895 0, NULL, NULL);
896
897 /*
898 * Here we free the message. We need to do that
899 * regardless of whether we got mbufs.
900 */
901 NG_FREE_MSG(msg);
902
903 if (m == NULL) {
904 SOCKBUF_UNLOCK(&so->so_rcv);
905 TRAP_ERROR;
906 return (ENOBUFS);
907 }
908
909 /* Send it up to the socket. */
910 if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)&addr, m,
911 NULL) == 0) {
912 soroverflow_locked(so);
913 TRAP_ERROR;
914 m_freem(m);
915 return (ENOBUFS);
916 }
917
918 /* sorwakeup_locked () releases the lock internally. */
919 sorwakeup_locked(so);
920
921 return (error);
922 }
923
924 /*
925 * Receive data on a hook
926 */
927 static int
ngs_rcvdata(hook_p hook,item_p item)928 ngs_rcvdata(hook_p hook, item_p item)
929 {
930 struct ngsock *const priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
931 struct ngpcb *const pcbp = priv->datasock;
932 struct socket *so;
933 struct sockaddr_ng *addr;
934 char *addrbuf[NG_HOOKSIZ + 4];
935 int addrlen;
936 struct mbuf *m;
937
938 NGI_GET_M(item, m);
939 NG_FREE_ITEM(item);
940
941 /* If there is no data socket, black-hole it. */
942 if (pcbp == NULL) {
943 NG_FREE_M(m);
944 return (0);
945 }
946 so = pcbp->ng_socket;
947
948 /* Get the return address into a sockaddr. */
949 addrlen = strlen(NG_HOOK_NAME(hook)); /* <= NG_HOOKSIZ - 1 */
950 addr = (struct sockaddr_ng *) addrbuf;
951 addr->sg_len = addrlen + 3;
952 addr->sg_family = AF_NETGRAPH;
953 bcopy(NG_HOOK_NAME(hook), addr->sg_data, addrlen);
954 addr->sg_data[addrlen] = '\0';
955
956 /* Try to tell the socket which hook it came in on. */
957 SOCKBUF_LOCK(&so->so_rcv);
958 if (sbappendaddr_locked(&so->so_rcv, (struct sockaddr *)addr, m,
959 NULL) == 0) {
960 SOCKBUF_UNLOCK(&so->so_rcv);
961 m_freem(m);
962 TRAP_ERROR;
963 return (ENOBUFS);
964 }
965
966 /* sorwakeup_locked () releases the lock internally. */
967 sorwakeup_locked(so);
968 return (0);
969 }
970
971 /*
972 * Hook disconnection
973 *
974 * For this type, removal of the last link destroys the node
975 * if the NOLINGER flag is set.
976 */
977 static int
ngs_disconnect(hook_p hook)978 ngs_disconnect(hook_p hook)
979 {
980 node_p node = NG_HOOK_NODE(hook);
981 struct ngsock *const priv = NG_NODE_PRIVATE(node);
982 struct hookpriv *hp = NG_HOOK_PRIVATE(hook);
983
984 LIST_REMOVE(hp, next);
985 free(hp, M_NETGRAPH_SOCK);
986
987 if ((priv->datasock) && (priv->datasock->ng_socket)) {
988 if (NG_NODE_NUMHOOKS(node) == 1)
989 priv->datasock->ng_socket->so_state |= SS_ISCONNECTED;
990 else
991 priv->datasock->ng_socket->so_state &= ~SS_ISCONNECTED;
992 }
993
994 if ((priv->flags & NGS_FLAG_NOLINGER) &&
995 (NG_NODE_NUMHOOKS(node) == 0) && (NG_NODE_IS_VALID(node)))
996 ng_rmnode_self(node);
997
998 return (0);
999 }
1000
1001 /*
1002 * Do local shutdown processing.
1003 * In this case, that involves making sure the socket
1004 * knows we should be shutting down.
1005 */
1006 static int
ngs_shutdown(node_p node)1007 ngs_shutdown(node_p node)
1008 {
1009 struct ngsock *const priv = NG_NODE_PRIVATE(node);
1010 struct ngpcb *dpcbp, *pcbp;
1011
1012 mtx_lock(&priv->mtx);
1013 dpcbp = priv->datasock;
1014 pcbp = priv->ctlsock;
1015
1016 if (dpcbp != NULL)
1017 soisdisconnected(dpcbp->ng_socket);
1018
1019 if (pcbp != NULL)
1020 soisdisconnected(pcbp->ng_socket);
1021
1022 priv->node = NULL;
1023 NG_NODE_SET_PRIVATE(node, NULL);
1024 ng_socket_free_priv(priv);
1025
1026 NG_NODE_UNREF(node);
1027 return (0);
1028 }
1029
1030 static void
ng_socket_item_applied(void * context,int error)1031 ng_socket_item_applied(void *context, int error)
1032 {
1033 struct ngsock *const priv = (struct ngsock *)context;
1034
1035 mtx_lock(&priv->mtx);
1036 priv->error = error;
1037 wakeup(priv);
1038 mtx_unlock(&priv->mtx);
1039
1040 }
1041
1042 static int
dummy_disconnect(struct socket * so)1043 dummy_disconnect(struct socket *so)
1044 {
1045 return (0);
1046 }
1047
1048 /*
1049 * Definitions of protocols supported in the NETGRAPH domain.
1050 * Control and data socket type descriptors
1051 *
1052 * XXXRW: Perhaps _close should do something?
1053 */
1054 static struct protosw ngcontrol_protosw = {
1055 .pr_type = SOCK_DGRAM,
1056 .pr_protocol = NG_CONTROL,
1057 .pr_flags = PR_ATOMIC | PR_ADDR /* | PR_RIGHTS */,
1058 .pr_attach = ngc_attach,
1059 .pr_bind = ngc_bind,
1060 .pr_detach = ng_detach_common,
1061 .pr_disconnect = dummy_disconnect,
1062 .pr_send = ngc_send,
1063 .pr_sockaddr = ng_getsockaddr,
1064 };
1065 static struct protosw ngdata_protosw = {
1066 .pr_type = SOCK_DGRAM,
1067 .pr_protocol = NG_DATA,
1068 .pr_flags = PR_ATOMIC | PR_ADDR,
1069 .pr_attach = ng_attach_common,
1070 .pr_connect = ngd_connect,
1071 .pr_detach = ng_detach_common,
1072 .pr_disconnect = dummy_disconnect,
1073 .pr_send = ngd_send,
1074 .pr_sockaddr = ng_getsockaddr,
1075 };
1076
1077 static struct domain ngdomain = {
1078 .dom_family = AF_NETGRAPH,
1079 .dom_name = "netgraph",
1080 .dom_nprotosw = 2,
1081 .dom_protosw = { &ngcontrol_protosw, &ngdata_protosw },
1082 };
1083
1084 /*
1085 * Handle loading and unloading for this node type.
1086 * This is to handle auxiliary linkages (e.g protocol domain addition).
1087 */
1088 static int
ngs_mod_event(module_t mod,int event,void * data)1089 ngs_mod_event(module_t mod, int event, void *data)
1090 {
1091 int error = 0;
1092
1093 switch (event) {
1094 case MOD_LOAD:
1095 mtx_init(&ngsocketlist_mtx, "ng_socketlist", NULL, MTX_DEF);
1096 break;
1097 case MOD_UNLOAD:
1098 /* Ensure there are no open netgraph sockets. */
1099 if (!LIST_EMPTY(&ngsocklist)) {
1100 error = EBUSY;
1101 break;
1102 }
1103 #ifdef NOTYET
1104 /* Unregister protocol domain XXX can't do this yet.. */
1105 #endif
1106 error = EBUSY;
1107 break;
1108 default:
1109 error = EOPNOTSUPP;
1110 break;
1111 }
1112 return (error);
1113 }
1114
1115 DOMAIN_SET(ng);
1116
1117 SYSCTL_INT(_net_graph, OID_AUTO, family, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, AF_NETGRAPH, "");
1118 static SYSCTL_NODE(_net_graph, OID_AUTO, data, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1119 "DATA");
1120 SYSCTL_INT(_net_graph_data, OID_AUTO, proto, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, NG_DATA, "");
1121 static SYSCTL_NODE(_net_graph, OID_AUTO, control, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
1122 "CONTROL");
1123 SYSCTL_INT(_net_graph_control, OID_AUTO, proto, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, NG_CONTROL, "");
1124