xref: /freebsd/sys/netgraph/ng_source.c (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
1 /*
2  * ng_source.c
3  */
4 
5 /*-
6  * Copyright (c) 2005 Gleb Smirnoff <glebius@FreeBSD.org>
7  * Copyright 2002 Sandvine Inc.
8  * All rights reserved.
9  *
10  * Subject to the following obligations and disclaimer of warranty, use and
11  * redistribution of this software, in source or object code forms, with or
12  * without modifications are expressly permitted by Sandvine Inc.; provided,
13  * however, that:
14  * 1. Any and all reproductions of the source or object code must include the
15  *    copyright notice above and the following disclaimer of warranties; and
16  * 2. No rights are granted, in any manner or form, to use Sandvine Inc.
17  *    trademarks, including the mark "SANDVINE" on advertising, endorsements,
18  *    or otherwise except as such appears in the above copyright notice or in
19  *    the software.
20  *
21  * THIS SOFTWARE IS BEING PROVIDED BY SANDVINE "AS IS", AND TO THE MAXIMUM
22  * EXTENT PERMITTED BY LAW, SANDVINE MAKES NO REPRESENTATIONS OR WARRANTIES,
23  * EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, INCLUDING WITHOUT LIMITATION,
24  * ANY AND ALL IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
25  * PURPOSE, OR NON-INFRINGEMENT.  SANDVINE DOES NOT WARRANT, GUARANTEE, OR
26  * MAKE ANY REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE
27  * USE OF THIS SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY
28  * OR OTHERWISE.  IN NO EVENT SHALL SANDVINE 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 SANDVINE IS ADVISED OF THE POSSIBILITY OF SUCH
36  * DAMAGE.
37  *
38  * Author: Dave Chapeskie
39  */
40 
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 /*
45  * This node is used for high speed packet geneneration.  It queues
46  * all data received on its 'input' hook and when told to start via
47  * a control message it sends the packets out its 'output' hook.  In
48  * this way this node can be preloaded with a packet stream which it
49  * can then send continuously as fast as possible.
50  *
51  * Currently it just copies the mbufs as required.  It could do various
52  * tricks to try and avoid this.  Probably the best performance would
53  * be achieved by modifying the appropriate drivers to be told to
54  * self-re-enqueue packets (e.g. the if_bge driver could reuse the same
55  * transmit descriptors) under control of this node; perhaps via some
56  * flag in the mbuf or some such.  The node could peek at an appropriate
57  * ifnet flag to see if such support is available for the connected
58  * interface.
59  */
60 
61 #include <sys/param.h>
62 #include <sys/systm.h>
63 #include <sys/errno.h>
64 #include <sys/kernel.h>
65 #include <sys/malloc.h>
66 #include <sys/mbuf.h>
67 #include <sys/socket.h>
68 #include <sys/syslog.h>
69 #include <net/if.h>
70 #include <net/if_var.h>
71 #include <netgraph/ng_message.h>
72 #include <netgraph/netgraph.h>
73 #include <netgraph/ng_parse.h>
74 #include <netgraph/ng_ether.h>
75 #include <netgraph/ng_source.h>
76 
77 #define NG_SOURCE_INTR_TICKS		1
78 #define NG_SOURCE_DRIVER_IFQ_MAXLEN	(4*1024)
79 
80 #define	mtod_off(m,off,t)	((t)(mtod((m),caddr_t)+(off)))
81 
82 /* Per node info */
83 struct privdata {
84 	node_p				node;
85 	hook_p				input;
86 	hook_p				output;
87 	struct ng_source_stats		stats;
88 	struct ifqueue			snd_queue;	/* packets to send */
89 	struct mbuf			*last_packet;	/* last pkt in queue */
90 	struct ifnet			*output_ifp;
91 	struct callout			intr_ch;
92 	uint64_t			packets;	/* packets to send */
93 	uint32_t			queueOctets;
94 	struct ng_source_embed_info	embed_timestamp;
95 	struct ng_source_embed_cnt_info	embed_counter[NG_SOURCE_COUNTERS];
96 };
97 typedef struct privdata *sc_p;
98 
99 /* Node flags */
100 #define NG_SOURCE_ACTIVE	(NGF_TYPE1)
101 
102 /* Netgraph methods */
103 static ng_constructor_t	ng_source_constructor;
104 static ng_rcvmsg_t	ng_source_rcvmsg;
105 static ng_shutdown_t	ng_source_rmnode;
106 static ng_newhook_t	ng_source_newhook;
107 static ng_connect_t	ng_source_connect;
108 static ng_rcvdata_t	ng_source_rcvdata;
109 static ng_disconnect_t	ng_source_disconnect;
110 
111 /* Other functions */
112 static void		ng_source_intr(node_p, hook_p, void *, int);
113 static void		ng_source_clr_data (sc_p);
114 static int		ng_source_start (sc_p, uint64_t);
115 static void		ng_source_stop (sc_p);
116 static int		ng_source_send (sc_p, int, int *);
117 static int		ng_source_store_output_ifp(sc_p, char *);
118 static void		ng_source_packet_mod(sc_p, struct mbuf *,
119 			    int, int, caddr_t, int);
120 static void		ng_source_mod_counter(sc_p sc,
121 			    struct ng_source_embed_cnt_info *cnt,
122 			    struct mbuf *m, int increment);
123 static int		ng_source_dup_mod(sc_p, struct mbuf *,
124 			    struct mbuf **);
125 
126 /* Parse type for timeval */
127 static const struct ng_parse_struct_field ng_source_timeval_type_fields[] = {
128 #ifdef __i386__
129 	{ "tv_sec",		&ng_parse_int32_type	},
130 #else
131 	{ "tv_sec",		&ng_parse_int64_type	},
132 #endif
133 #ifdef __LP64__
134 	{ "tv_usec",		&ng_parse_int64_type	},
135 #else
136 	{ "tv_usec",		&ng_parse_int32_type	},
137 #endif
138 	{ NULL }
139 };
140 const struct ng_parse_type ng_source_timeval_type = {
141 	&ng_parse_struct_type,
142 	&ng_source_timeval_type_fields
143 };
144 
145 /* Parse type for struct ng_source_stats */
146 static const struct ng_parse_struct_field ng_source_stats_type_fields[]
147 	= NG_SOURCE_STATS_TYPE_INFO;
148 static const struct ng_parse_type ng_source_stats_type = {
149 	&ng_parse_struct_type,
150 	&ng_source_stats_type_fields
151 };
152 
153 /* Parse type for struct ng_source_embed_info */
154 static const struct ng_parse_struct_field ng_source_embed_type_fields[] =
155 	NG_SOURCE_EMBED_TYPE_INFO;
156 static const struct ng_parse_type ng_source_embed_type = {
157 	&ng_parse_struct_type,
158 	&ng_source_embed_type_fields
159 };
160 
161 /* Parse type for struct ng_source_embed_cnt_info */
162 static const struct ng_parse_struct_field ng_source_embed_cnt_type_fields[] =
163 	NG_SOURCE_EMBED_CNT_TYPE_INFO;
164 static const struct ng_parse_type ng_source_embed_cnt_type = {
165 	&ng_parse_struct_type,
166 	&ng_source_embed_cnt_type_fields
167 };
168 
169 /* List of commands and how to convert arguments to/from ASCII */
170 static const struct ng_cmdlist ng_source_cmds[] = {
171 	{
172 	  NGM_SOURCE_COOKIE,
173 	  NGM_SOURCE_GET_STATS,
174 	  "getstats",
175 	  NULL,
176 	  &ng_source_stats_type
177 	},
178 	{
179 	  NGM_SOURCE_COOKIE,
180 	  NGM_SOURCE_CLR_STATS,
181 	  "clrstats",
182 	  NULL,
183 	  NULL
184 	},
185 	{
186 	  NGM_SOURCE_COOKIE,
187 	  NGM_SOURCE_GETCLR_STATS,
188 	  "getclrstats",
189 	  NULL,
190 	  &ng_source_stats_type
191 	},
192 	{
193 	  NGM_SOURCE_COOKIE,
194 	  NGM_SOURCE_START,
195 	  "start",
196 	  &ng_parse_uint64_type,
197 	  NULL
198 	},
199 	{
200 	  NGM_SOURCE_COOKIE,
201 	  NGM_SOURCE_STOP,
202 	  "stop",
203 	  NULL,
204 	  NULL
205 	},
206 	{
207 	  NGM_SOURCE_COOKIE,
208 	  NGM_SOURCE_CLR_DATA,
209 	  "clrdata",
210 	  NULL,
211 	  NULL
212 	},
213 	{
214 	  NGM_SOURCE_COOKIE,
215 	  NGM_SOURCE_SETIFACE,
216 	  "setiface",
217 	  &ng_parse_string_type,
218 	  NULL
219 	},
220 	{
221 	  NGM_SOURCE_COOKIE,
222 	  NGM_SOURCE_SETPPS,
223 	  "setpps",
224 	  &ng_parse_uint32_type,
225 	  NULL
226 	},
227 	{
228 	  NGM_SOURCE_COOKIE,
229 	  NGM_SOURCE_SET_TIMESTAMP,
230 	  "settimestamp",
231 	  &ng_source_embed_type,
232 	  NULL
233 	},
234 	{
235 	  NGM_SOURCE_COOKIE,
236 	  NGM_SOURCE_GET_TIMESTAMP,
237 	  "gettimestamp",
238 	  NULL,
239 	  &ng_source_embed_type
240 	},
241 	{
242 	  NGM_SOURCE_COOKIE,
243 	  NGM_SOURCE_SET_COUNTER,
244 	  "setcounter",
245 	  &ng_source_embed_cnt_type,
246 	  NULL
247 	},
248 	{
249 	  NGM_SOURCE_COOKIE,
250 	  NGM_SOURCE_GET_COUNTER,
251 	  "getcounter",
252 	  &ng_parse_uint8_type,
253 	  &ng_source_embed_cnt_type
254 	},
255 	{ 0 }
256 };
257 
258 /* Netgraph type descriptor */
259 static struct ng_type ng_source_typestruct = {
260 	.version =	NG_ABI_VERSION,
261 	.name =		NG_SOURCE_NODE_TYPE,
262 	.constructor =	ng_source_constructor,
263 	.rcvmsg =	ng_source_rcvmsg,
264 	.shutdown =	ng_source_rmnode,
265 	.newhook =	ng_source_newhook,
266 	.connect =	ng_source_connect,
267 	.rcvdata =	ng_source_rcvdata,
268 	.disconnect =	ng_source_disconnect,
269 	.cmdlist =	ng_source_cmds,
270 };
271 NETGRAPH_INIT(source, &ng_source_typestruct);
272 
273 static int ng_source_set_autosrc(sc_p, uint32_t);
274 
275 /*
276  * Node constructor
277  */
278 static int
279 ng_source_constructor(node_p node)
280 {
281 	sc_p sc;
282 
283 	sc = malloc(sizeof(*sc), M_NETGRAPH, M_WAITOK | M_ZERO);
284 
285 	NG_NODE_SET_PRIVATE(node, sc);
286 	sc->node = node;
287 	sc->snd_queue.ifq_maxlen = 2048;	/* XXX not checked */
288 	ng_callout_init(&sc->intr_ch);
289 
290 	return (0);
291 }
292 
293 /*
294  * Add a hook
295  */
296 static int
297 ng_source_newhook(node_p node, hook_p hook, const char *name)
298 {
299 	sc_p sc = NG_NODE_PRIVATE(node);
300 
301 	if (strcmp(name, NG_SOURCE_HOOK_INPUT) == 0) {
302 		sc->input = hook;
303 	} else if (strcmp(name, NG_SOURCE_HOOK_OUTPUT) == 0) {
304 		sc->output = hook;
305 		sc->output_ifp = NULL;
306 		bzero(&sc->stats, sizeof(sc->stats));
307 	} else
308 		return (EINVAL);
309 
310 	return (0);
311 }
312 
313 /*
314  * Hook has been added
315  */
316 static int
317 ng_source_connect(hook_p hook)
318 {
319 	sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
320 	struct ng_mesg *msg;
321 	int dummy_error = 0;
322 
323 	/*
324 	 * If this is "output" hook, then request information
325 	 * from our downstream.
326 	 */
327 	if (hook == sc->output) {
328 		NG_MKMESSAGE(msg, NGM_ETHER_COOKIE, NGM_ETHER_GET_IFNAME,
329 		    0, M_NOWAIT);
330 		if (msg == NULL)
331 			return (ENOBUFS);
332 
333 		/*
334 		 * Our hook and peer hook have HK_INVALID flag set,
335 		 * so we can't use NG_SEND_MSG_HOOK() macro here.
336 		 */
337 		NG_SEND_MSG_ID(dummy_error, sc->node, msg,
338 		    NG_NODE_ID(NG_PEER_NODE(sc->output)), NG_NODE_ID(sc->node));
339 	}
340 
341 	return (0);
342 }
343 
344 /*
345  * Receive a control message
346  */
347 static int
348 ng_source_rcvmsg(node_p node, item_p item, hook_p lasthook)
349 {
350 	sc_p sc = NG_NODE_PRIVATE(node);
351 	struct ng_mesg *msg, *resp = NULL;
352 	int error = 0;
353 
354 	NGI_GET_MSG(item, msg);
355 
356 	switch (msg->header.typecookie) {
357 	case NGM_SOURCE_COOKIE:
358 		if (msg->header.flags & NGF_RESP) {
359 			error = EINVAL;
360 			break;
361 		}
362 		switch (msg->header.cmd) {
363 		case NGM_SOURCE_GET_STATS:
364 		case NGM_SOURCE_CLR_STATS:
365 		case NGM_SOURCE_GETCLR_STATS:
366                     {
367 			struct ng_source_stats *stats;
368 
369                         if (msg->header.cmd != NGM_SOURCE_CLR_STATS) {
370                                 NG_MKRESPONSE(resp, msg,
371                                     sizeof(*stats), M_NOWAIT);
372 				if (resp == NULL) {
373 					error = ENOMEM;
374 					goto done;
375 				}
376 				sc->stats.queueOctets = sc->queueOctets;
377 				sc->stats.queueFrames = sc->snd_queue.ifq_len;
378 				if ((sc->node->nd_flags & NG_SOURCE_ACTIVE)
379 				    && !timevalisset(&sc->stats.endTime)) {
380 					getmicrotime(&sc->stats.elapsedTime);
381 					timevalsub(&sc->stats.elapsedTime,
382 					    &sc->stats.startTime);
383 				}
384 				stats = (struct ng_source_stats *)resp->data;
385 				bcopy(&sc->stats, stats, sizeof(* stats));
386                         }
387                         if (msg->header.cmd != NGM_SOURCE_GET_STATS)
388 				bzero(&sc->stats, sizeof(sc->stats));
389 		    }
390 		    break;
391 		case NGM_SOURCE_START:
392 		    {
393 			uint64_t packets;
394 
395 			if (msg->header.arglen != sizeof(uint64_t)) {
396 				error = EINVAL;
397 				break;
398 			}
399 
400 			packets = *(uint64_t *)msg->data;
401 
402 			error = ng_source_start(sc, packets);
403 
404 		    	break;
405 		    }
406 		case NGM_SOURCE_STOP:
407 			ng_source_stop(sc);
408 			break;
409 		case NGM_SOURCE_CLR_DATA:
410 			ng_source_clr_data(sc);
411 			break;
412 		case NGM_SOURCE_SETIFACE:
413 		    {
414 			char *ifname = (char *)msg->data;
415 
416 			if (msg->header.arglen < 2) {
417 				error = EINVAL;
418 				break;
419 			}
420 
421 			ng_source_store_output_ifp(sc, ifname);
422 			break;
423 		    }
424 		case NGM_SOURCE_SETPPS:
425 		    {
426 			uint32_t pps;
427 
428 			if (msg->header.arglen != sizeof(uint32_t)) {
429 				error = EINVAL;
430 				break;
431 			}
432 
433 			pps = *(uint32_t *)msg->data;
434 
435 			sc->stats.maxPps = pps;
436 
437 			break;
438 		    }
439 		case NGM_SOURCE_SET_TIMESTAMP:
440 		    {
441 			struct ng_source_embed_info *embed;
442 
443 			if (msg->header.arglen != sizeof(*embed)) {
444 				error = EINVAL;
445 				goto done;
446 			}
447 			embed = (struct ng_source_embed_info *)msg->data;
448 			bcopy(embed, &sc->embed_timestamp, sizeof(*embed));
449 
450 			break;
451 		    }
452 		case NGM_SOURCE_GET_TIMESTAMP:
453 		    {
454 			struct ng_source_embed_info *embed;
455 
456 			NG_MKRESPONSE(resp, msg, sizeof(*embed), M_NOWAIT);
457 			if (resp == NULL) {
458 				error = ENOMEM;
459 				goto done;
460 			}
461 			embed = (struct ng_source_embed_info *)resp->data;
462 			bcopy(&sc->embed_timestamp, embed, sizeof(*embed));
463 
464 			break;
465 		    }
466 		case NGM_SOURCE_SET_COUNTER:
467 		    {
468 			struct ng_source_embed_cnt_info *embed;
469 
470 			if (msg->header.arglen != sizeof(*embed)) {
471 				error = EINVAL;
472 				goto done;
473 			}
474 			embed = (struct ng_source_embed_cnt_info *)msg->data;
475 			if (embed->index >= NG_SOURCE_COUNTERS ||
476 			    !(embed->width == 1 || embed->width == 2 ||
477 			    embed->width == 4)) {
478 				error = EINVAL;
479 				goto done;
480 			}
481 			bcopy(embed, &sc->embed_counter[embed->index],
482 			    sizeof(*embed));
483 
484 			break;
485 		    }
486 		case NGM_SOURCE_GET_COUNTER:
487 		    {
488 			uint8_t index = *(uint8_t *)msg->data;
489 			struct ng_source_embed_cnt_info *embed;
490 
491 			if (index >= NG_SOURCE_COUNTERS) {
492 				error = EINVAL;
493 				goto done;
494 			}
495 			NG_MKRESPONSE(resp, msg, sizeof(*embed), M_NOWAIT);
496 			if (resp == NULL) {
497 				error = ENOMEM;
498 				goto done;
499 			}
500 			embed = (struct ng_source_embed_cnt_info *)resp->data;
501 			bcopy(&sc->embed_counter[index], embed, sizeof(*embed));
502 
503 			break;
504 		    }
505 		default:
506 			error = EINVAL;
507 			break;
508 		}
509 		break;
510 	case NGM_ETHER_COOKIE:
511 		if (!(msg->header.flags & NGF_RESP)) {
512 			error = EINVAL;
513 			break;
514 		}
515 		switch (msg->header.cmd) {
516 		case NGM_ETHER_GET_IFNAME:
517 		    {
518 			char *ifname = (char *)msg->data;
519 
520 			if (msg->header.arglen < 2) {
521 				error = EINVAL;
522 				break;
523 			}
524 
525 			if (ng_source_store_output_ifp(sc, ifname) == 0)
526 				ng_source_set_autosrc(sc, 0);
527 			break;
528 		    }
529 		default:
530 			error = EINVAL;
531 		}
532 		break;
533 	default:
534 		error = EINVAL;
535 		break;
536 	}
537 
538 done:
539 	/* Take care of synchronous response, if any. */
540 	NG_RESPOND_MSG(error, node, item, resp);
541 	/* Free the message and return. */
542 	NG_FREE_MSG(msg);
543 	return (error);
544 }
545 
546 /*
547  * Receive data on a hook
548  *
549  * If data comes in the input hook, enqueue it on the send queue.
550  * If data comes in the output hook, discard it.
551  */
552 static int
553 ng_source_rcvdata(hook_p hook, item_p item)
554 {
555 	sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
556 	struct mbuf *m;
557 	int error = 0;
558 
559 	NGI_GET_M(item, m);
560 	NG_FREE_ITEM(item);
561 
562 	/* Which hook? */
563 	if (hook == sc->output) {
564 		/* discard */
565 		NG_FREE_M(m);
566 		return (error);
567 	}
568 	KASSERT(hook == sc->input, ("%s: no hook!", __func__));
569 
570 	/* Enqueue packet. */
571 	/* XXX should we check IF_QFULL() ? */
572 	_IF_ENQUEUE(&sc->snd_queue, m);
573 	sc->queueOctets += m->m_pkthdr.len;
574 	sc->last_packet = m;
575 
576 	return (0);
577 }
578 
579 /*
580  * Shutdown processing
581  */
582 static int
583 ng_source_rmnode(node_p node)
584 {
585 	sc_p sc = NG_NODE_PRIVATE(node);
586 
587 	ng_source_stop(sc);
588 	ng_source_clr_data(sc);
589 	NG_NODE_SET_PRIVATE(node, NULL);
590 	NG_NODE_UNREF(node);
591 	free(sc, M_NETGRAPH);
592 
593 	return (0);
594 }
595 
596 /*
597  * Hook disconnection
598  */
599 static int
600 ng_source_disconnect(hook_p hook)
601 {
602 	sc_p sc;
603 
604 	sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
605 	KASSERT(sc != NULL, ("%s: null node private", __func__));
606 	if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0 || hook == sc->output)
607 		ng_rmnode_self(NG_HOOK_NODE(hook));
608 	return (0);
609 }
610 
611 /*
612  * Set sc->output_ifp to point to the struct ifnet of the interface
613  * reached via our output hook.
614  */
615 static int
616 ng_source_store_output_ifp(sc_p sc, char *ifname)
617 {
618 	struct ifnet *ifp;
619 
620 	ifp = ifunit(ifname);
621 
622 	if (ifp == NULL) {
623 		printf("%s: can't find interface %s\n", __func__, ifname);
624 		return (EINVAL);
625 	}
626 	sc->output_ifp = ifp;
627 
628 #if 1
629 	/* XXX mucking with a drivers ifqueue size is ugly but we need it
630 	 * to queue a lot of packets to get close to line rate on a gigabit
631 	 * interface with small packets.
632 	 * XXX we should restore the original value at stop or disconnect
633 	 */
634 	if (ifp->if_snd.ifq_maxlen < NG_SOURCE_DRIVER_IFQ_MAXLEN) {
635 		printf("ng_source: changing ifq_maxlen from %d to %d\n",
636 		    ifp->if_snd.ifq_maxlen, NG_SOURCE_DRIVER_IFQ_MAXLEN);
637 		ifp->if_snd.ifq_maxlen = NG_SOURCE_DRIVER_IFQ_MAXLEN;
638 	}
639 #endif
640 	return (0);
641 }
642 
643 /*
644  * Set the attached ethernet node's ethernet source address override flag.
645  */
646 static int
647 ng_source_set_autosrc(sc_p sc, uint32_t flag)
648 {
649 	struct ng_mesg *msg;
650 	int error = 0;
651 
652 	NG_MKMESSAGE(msg, NGM_ETHER_COOKIE, NGM_ETHER_SET_AUTOSRC,
653 	    sizeof (uint32_t), M_NOWAIT);
654 	if (msg == NULL)
655 		return(ENOBUFS);
656 
657 	*(uint32_t *)msg->data = flag;
658 	NG_SEND_MSG_HOOK(error, sc->node, msg, sc->output, 0);
659 	return (error);
660 }
661 
662 /*
663  * Clear out the data we've queued
664  */
665 static void
666 ng_source_clr_data (sc_p sc)
667 {
668 	struct mbuf *m;
669 
670 	for (;;) {
671 		_IF_DEQUEUE(&sc->snd_queue, m);
672 		if (m == NULL)
673 			break;
674 		NG_FREE_M(m);
675 	}
676 	sc->queueOctets = 0;
677 	sc->last_packet = NULL;
678 }
679 
680 /*
681  * Start sending queued data out the output hook
682  */
683 static int
684 ng_source_start(sc_p sc, uint64_t packets)
685 {
686 	if (sc->output_ifp == NULL) {
687 		printf("ng_source: start without iface configured\n");
688 		return (ENXIO);
689 	}
690 
691 	if (sc->node->nd_flags & NG_SOURCE_ACTIVE)
692 		return (EBUSY);
693 
694 	sc->node->nd_flags |= NG_SOURCE_ACTIVE;
695 
696 	sc->packets = packets;
697 	timevalclear(&sc->stats.elapsedTime);
698 	timevalclear(&sc->stats.endTime);
699 	getmicrotime(&sc->stats.startTime);
700 	getmicrotime(&sc->stats.lastTime);
701 	ng_callout(&sc->intr_ch, sc->node, NULL, 0,
702 	    ng_source_intr, sc, 0);
703 
704 	return (0);
705 }
706 
707 /*
708  * Stop sending queued data out the output hook
709  */
710 static void
711 ng_source_stop(sc_p sc)
712 {
713 	ng_uncallout(&sc->intr_ch, sc->node);
714 	sc->node->nd_flags &= ~NG_SOURCE_ACTIVE;
715 	getmicrotime(&sc->stats.endTime);
716 	sc->stats.elapsedTime = sc->stats.endTime;
717 	timevalsub(&sc->stats.elapsedTime, &sc->stats.startTime);
718 }
719 
720 /*
721  * While active called every NG_SOURCE_INTR_TICKS ticks.
722  * Sends as many packets as the interface connected to our
723  * output hook is able to enqueue.
724  */
725 static void
726 ng_source_intr(node_p node, hook_p hook, void *arg1, int arg2)
727 {
728 	sc_p sc = (sc_p)arg1;
729 	struct ifqueue *ifq;
730 	int packets;
731 
732 	KASSERT(sc != NULL, ("%s: null node private", __func__));
733 
734 	if (sc->packets == 0 || sc->output == NULL
735 	    || (sc->node->nd_flags & NG_SOURCE_ACTIVE) == 0) {
736 		ng_source_stop(sc);
737 		return;
738 	}
739 
740 	if (sc->output_ifp != NULL) {
741 		ifq = (struct ifqueue *)&sc->output_ifp->if_snd;
742 		packets = ifq->ifq_maxlen - ifq->ifq_len;
743 	} else
744 		packets = sc->snd_queue.ifq_len;
745 
746 	if (sc->stats.maxPps != 0) {
747 		struct timeval	now, elapsed;
748 		uint64_t	usec;
749 		int		maxpkt;
750 
751 		getmicrotime(&now);
752 		elapsed = now;
753 		timevalsub(&elapsed, &sc->stats.lastTime);
754 		usec = elapsed.tv_sec * 1000000 + elapsed.tv_usec;
755 		maxpkt = (uint64_t)sc->stats.maxPps * usec / 1000000;
756 		sc->stats.lastTime = now;
757 		if (packets > maxpkt)
758 			packets = maxpkt;
759 	}
760 
761 	ng_source_send(sc, packets, NULL);
762 	if (sc->packets == 0)
763 		ng_source_stop(sc);
764 	else
765 		ng_callout(&sc->intr_ch, node, NULL, NG_SOURCE_INTR_TICKS,
766 		    ng_source_intr, sc, 0);
767 }
768 
769 /*
770  * Send packets out our output hook.
771  */
772 static int
773 ng_source_send(sc_p sc, int tosend, int *sent_p)
774 {
775 	struct mbuf *m, *m2;
776 	int sent;
777 	int error = 0;
778 
779 	KASSERT(tosend >= 0, ("%s: negative tosend param", __func__));
780 	KASSERT(sc->node->nd_flags & NG_SOURCE_ACTIVE,
781 	    ("%s: inactive node", __func__));
782 
783 	if ((uint64_t)tosend > sc->packets)
784 		tosend = sc->packets;
785 
786 	/* Go through the queue sending packets one by one. */
787 	for (sent = 0; error == 0 && sent < tosend; ++sent) {
788 		_IF_DEQUEUE(&sc->snd_queue, m);
789 		if (m == NULL)
790 			break;
791 
792 		/* Duplicate and modify the packet. */
793 		error = ng_source_dup_mod(sc, m, &m2);
794 		if (error) {
795 			if (error == ENOBUFS)
796 				_IF_PREPEND(&sc->snd_queue, m);
797 			else
798 				_IF_ENQUEUE(&sc->snd_queue, m);
799 			break;
800 		}
801 
802 		/* Re-enqueue the original packet for us. */
803 		_IF_ENQUEUE(&sc->snd_queue, m);
804 
805 		sc->stats.outFrames++;
806 		sc->stats.outOctets += m2->m_pkthdr.len;
807 		NG_SEND_DATA_ONLY(error, sc->output, m2);
808 		if (error)
809 			break;
810 	}
811 
812 	sc->packets -= sent;
813 	if (sent_p != NULL)
814 		*sent_p = sent;
815 	return (error);
816 }
817 
818 /*
819  * Modify packet in 'm' by changing 'len' bytes starting at 'offset'
820  * to data in 'cp'.
821  *
822  * The packet data in 'm' must be in a contiguous buffer in a single mbuf.
823  */
824 static void
825 ng_source_packet_mod(sc_p sc, struct mbuf *m, int offset, int len, caddr_t cp,
826     int flags)
827 {
828 	if (len == 0)
829 		return;
830 
831 	/* Can't modify beyond end of packet. */
832 	/* TODO: Pad packet for this case. */
833 	if (offset + len > m->m_len)
834 		return;
835 
836 	bcopy(cp, mtod_off(m, offset, caddr_t), len);
837 }
838 
839 static void
840 ng_source_mod_counter(sc_p sc, struct ng_source_embed_cnt_info *cnt,
841     struct mbuf *m, int increment)
842 {
843 	caddr_t cp;
844 	uint32_t val;
845 
846 	val = htonl(cnt->next_val);
847 	cp = (caddr_t)&val + sizeof(val) - cnt->width;
848 	ng_source_packet_mod(sc, m, cnt->offset, cnt->width, cp, cnt->flags);
849 
850 	if (increment) {
851 		cnt->next_val += increment;
852 
853 		if (increment > 0 && cnt->next_val > cnt->max_val) {
854 			cnt->next_val = cnt->min_val - 1 +
855 			    (cnt->next_val - cnt->max_val);
856 			if (cnt->next_val > cnt->max_val)
857 				cnt->next_val = cnt->max_val;
858 		} else if (increment < 0 && cnt->next_val < cnt->min_val) {
859 			cnt->next_val = cnt->max_val + 1 +
860 			    (cnt->next_val - cnt->min_val);
861 			if (cnt->next_val < cnt->min_val)
862 				cnt->next_val = cnt->max_val;
863 		}
864 	}
865 }
866 
867 static int
868 ng_source_dup_mod(sc_p sc, struct mbuf *m0, struct mbuf **m_ptr)
869 {
870 	struct mbuf *m;
871 	struct ng_source_embed_cnt_info *cnt;
872 	struct ng_source_embed_info *ts;
873 	int modify;
874 	int error = 0;
875 	int i, increment;
876 
877 	/* Are we going to modify packets? */
878 	modify = sc->embed_timestamp.flags & NGM_SOURCE_EMBED_ENABLE;
879 	for (i = 0; !modify && i < NG_SOURCE_COUNTERS; ++i)
880 		modify = sc->embed_counter[i].flags & NGM_SOURCE_EMBED_ENABLE;
881 
882 	/* Duplicate the packet. */
883 	if (modify)
884 		m = m_dup(m0, M_NOWAIT);
885 	else
886 		m = m_copypacket(m0, M_NOWAIT);
887 	if (m == NULL) {
888 		error = ENOBUFS;
889 		goto done;
890 	}
891 	*m_ptr = m;
892 
893 	if (!modify)
894 		goto done;
895 
896 	/* Modify the copied packet for sending. */
897 	KASSERT(M_WRITABLE(m), ("%s: packet not writable", __func__));
898 
899 	for (i = 0; i < NG_SOURCE_COUNTERS; ++i) {
900 		cnt = &sc->embed_counter[i];
901 		if (cnt->flags & NGM_SOURCE_EMBED_ENABLE) {
902 			if ((cnt->flags & NGM_SOURCE_INC_CNT_PER_LIST) == 0 ||
903 			    sc->last_packet == m0)
904 				increment = cnt->increment;
905 			else
906 				increment = 0;
907 			ng_source_mod_counter(sc, cnt, m, increment);
908 		}
909 	}
910 
911 	ts = &sc->embed_timestamp;
912 	if (ts->flags & NGM_SOURCE_EMBED_ENABLE) {
913 		struct timeval now;
914 		getmicrotime(&now);
915 		now.tv_sec = htonl(now.tv_sec);
916 		now.tv_usec = htonl(now.tv_usec);
917 		ng_source_packet_mod(sc, m, ts->offset, sizeof (now),
918 		    (caddr_t)&now, ts->flags);
919 	}
920 
921 done:
922 	return(error);
923 }
924