xref: /freebsd/sys/netgraph/ng_source.c (revision a0409676120c1e558d0ade943019934e0f15118d)
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 mbufq			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 	mbufq_init(&sc->snd_queue, 2048);
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 = mbufq_len(&sc->snd_queue);
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 if the queue isn't full. */
571 	error = mbufq_enqueue(&sc->snd_queue, m);
572 	if (error) {
573 		NG_FREE_M(m);
574 		return (error);
575 	}
576 	sc->queueOctets += m->m_pkthdr.len;
577 	sc->last_packet = m;
578 
579 	return (0);
580 }
581 
582 /*
583  * Shutdown processing
584  */
585 static int
586 ng_source_rmnode(node_p node)
587 {
588 	sc_p sc = NG_NODE_PRIVATE(node);
589 
590 	ng_source_stop(sc);
591 	ng_source_clr_data(sc);
592 	NG_NODE_SET_PRIVATE(node, NULL);
593 	NG_NODE_UNREF(node);
594 	free(sc, M_NETGRAPH);
595 
596 	return (0);
597 }
598 
599 /*
600  * Hook disconnection
601  */
602 static int
603 ng_source_disconnect(hook_p hook)
604 {
605 	sc_p sc;
606 
607 	sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
608 	KASSERT(sc != NULL, ("%s: null node private", __func__));
609 	if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0 || hook == sc->output)
610 		ng_rmnode_self(NG_HOOK_NODE(hook));
611 	return (0);
612 }
613 
614 /*
615  * Set sc->output_ifp to point to the struct ifnet of the interface
616  * reached via our output hook.
617  */
618 static int
619 ng_source_store_output_ifp(sc_p sc, char *ifname)
620 {
621 	struct ifnet *ifp;
622 
623 	ifp = ifunit(ifname);
624 
625 	if (ifp == NULL) {
626 		printf("%s: can't find interface %s\n", __func__, ifname);
627 		return (EINVAL);
628 	}
629 	sc->output_ifp = ifp;
630 
631 #if 1
632 	/* XXX mucking with a drivers ifqueue size is ugly but we need it
633 	 * to queue a lot of packets to get close to line rate on a gigabit
634 	 * interface with small packets.
635 	 * XXX we should restore the original value at stop or disconnect
636 	 */
637 	if (ifp->if_snd.ifq_maxlen < NG_SOURCE_DRIVER_IFQ_MAXLEN) {
638 		printf("ng_source: changing ifq_maxlen from %d to %d\n",
639 		    ifp->if_snd.ifq_maxlen, NG_SOURCE_DRIVER_IFQ_MAXLEN);
640 		ifp->if_snd.ifq_maxlen = NG_SOURCE_DRIVER_IFQ_MAXLEN;
641 	}
642 #endif
643 	return (0);
644 }
645 
646 /*
647  * Set the attached ethernet node's ethernet source address override flag.
648  */
649 static int
650 ng_source_set_autosrc(sc_p sc, uint32_t flag)
651 {
652 	struct ng_mesg *msg;
653 	int error = 0;
654 
655 	NG_MKMESSAGE(msg, NGM_ETHER_COOKIE, NGM_ETHER_SET_AUTOSRC,
656 	    sizeof (uint32_t), M_NOWAIT);
657 	if (msg == NULL)
658 		return(ENOBUFS);
659 
660 	*(uint32_t *)msg->data = flag;
661 	NG_SEND_MSG_HOOK(error, sc->node, msg, sc->output, 0);
662 	return (error);
663 }
664 
665 /*
666  * Clear out the data we've queued
667  */
668 static void
669 ng_source_clr_data (sc_p sc)
670 {
671 	struct mbuf *m;
672 
673 	for (;;) {
674 		m =  mbufq_dequeue(&sc->snd_queue);
675 		if (m == NULL)
676 			break;
677 		NG_FREE_M(m);
678 	}
679 	sc->queueOctets = 0;
680 	sc->last_packet = NULL;
681 }
682 
683 /*
684  * Start sending queued data out the output hook
685  */
686 static int
687 ng_source_start(sc_p sc, uint64_t packets)
688 {
689 	if (sc->output_ifp == NULL && sc->stats.maxPps == 0) {
690 		printf("ng_source: start without iface or pps configured\n");
691 		return (ENXIO);
692 	}
693 
694 	if (sc->node->nd_flags & NG_SOURCE_ACTIVE)
695 		return (EBUSY);
696 
697 	sc->node->nd_flags |= NG_SOURCE_ACTIVE;
698 
699 	sc->packets = packets;
700 	timevalclear(&sc->stats.elapsedTime);
701 	timevalclear(&sc->stats.endTime);
702 	getmicrotime(&sc->stats.startTime);
703 	getmicrotime(&sc->stats.lastTime);
704 	ng_callout(&sc->intr_ch, sc->node, NULL, 0,
705 	    ng_source_intr, sc, 0);
706 
707 	return (0);
708 }
709 
710 /*
711  * Stop sending queued data out the output hook
712  */
713 static void
714 ng_source_stop(sc_p sc)
715 {
716 	ng_uncallout(&sc->intr_ch, sc->node);
717 	sc->node->nd_flags &= ~NG_SOURCE_ACTIVE;
718 	getmicrotime(&sc->stats.endTime);
719 	sc->stats.elapsedTime = sc->stats.endTime;
720 	timevalsub(&sc->stats.elapsedTime, &sc->stats.startTime);
721 }
722 
723 /*
724  * While active called every NG_SOURCE_INTR_TICKS ticks.
725  * Sends as many packets as the interface connected to our
726  * output hook is able to enqueue.
727  */
728 static void
729 ng_source_intr(node_p node, hook_p hook, void *arg1, int arg2)
730 {
731 	sc_p sc = (sc_p)arg1;
732 	struct ifqueue *ifq;
733 	int packets;
734 
735 	KASSERT(sc != NULL, ("%s: null node private", __func__));
736 
737 	if (sc->packets == 0 || sc->output == NULL
738 	    || (sc->node->nd_flags & NG_SOURCE_ACTIVE) == 0) {
739 		ng_source_stop(sc);
740 		return;
741 	}
742 
743 	if (sc->output_ifp != NULL) {
744 		ifq = (struct ifqueue *)&sc->output_ifp->if_snd;
745 		packets = ifq->ifq_maxlen - ifq->ifq_len;
746 	} else
747 		packets = mbufq_len(&sc->snd_queue);
748 
749 	if (sc->stats.maxPps != 0) {
750 		struct timeval	now, elapsed;
751 		uint64_t	usec;
752 		int		maxpkt;
753 
754 		getmicrotime(&now);
755 		elapsed = now;
756 		timevalsub(&elapsed, &sc->stats.lastTime);
757 		usec = elapsed.tv_sec * 1000000 + elapsed.tv_usec;
758 		maxpkt = (uint64_t)sc->stats.maxPps * usec / 1000000;
759 		sc->stats.lastTime = now;
760 		if (packets > maxpkt)
761 			packets = maxpkt;
762 	}
763 
764 	ng_source_send(sc, packets, NULL);
765 	if (sc->packets == 0)
766 		ng_source_stop(sc);
767 	else
768 		ng_callout(&sc->intr_ch, node, NULL, NG_SOURCE_INTR_TICKS,
769 		    ng_source_intr, sc, 0);
770 }
771 
772 /*
773  * Send packets out our output hook.
774  */
775 static int
776 ng_source_send(sc_p sc, int tosend, int *sent_p)
777 {
778 	struct mbuf *m, *m2;
779 	int sent;
780 	int error = 0;
781 
782 	KASSERT(tosend >= 0, ("%s: negative tosend param", __func__));
783 	KASSERT(sc->node->nd_flags & NG_SOURCE_ACTIVE,
784 	    ("%s: inactive node", __func__));
785 
786 	if ((uint64_t)tosend > sc->packets)
787 		tosend = sc->packets;
788 
789 	/* Go through the queue sending packets one by one. */
790 	for (sent = 0; error == 0 && sent < tosend; ++sent) {
791 		m = mbufq_dequeue(&sc->snd_queue);
792 		if (m == NULL)
793 			break;
794 
795 		/* Duplicate and modify the packet. */
796 		error = ng_source_dup_mod(sc, m, &m2);
797 		if (error) {
798 			if (error == ENOBUFS)
799 				mbufq_prepend(&sc->snd_queue, m);
800 			else
801 				(void)mbufq_enqueue(&sc->snd_queue, m);
802 			break;
803 		}
804 
805 		/*
806 		 * Re-enqueue the original packet for us.  The queue
807 		 * has a free slot, because we dequeued the packet
808 		 * above and this callout function runs under WRITER
809 		 * lock.
810 		 */
811 		error = mbufq_enqueue(&sc->snd_queue, m);
812 		KASSERT(error == 0, ("%s: re-enqueue packet failed", __func__));
813 
814 		sc->stats.outFrames++;
815 		sc->stats.outOctets += m2->m_pkthdr.len;
816 		NG_SEND_DATA_ONLY(error, sc->output, m2);
817 		if (error)
818 			break;
819 	}
820 
821 	sc->packets -= sent;
822 	if (sent_p != NULL)
823 		*sent_p = sent;
824 	return (error);
825 }
826 
827 /*
828  * Modify packet in 'm' by changing 'len' bytes starting at 'offset'
829  * to data in 'cp'.
830  *
831  * The packet data in 'm' must be in a contiguous buffer in a single mbuf.
832  */
833 static void
834 ng_source_packet_mod(sc_p sc, struct mbuf *m, int offset, int len, caddr_t cp,
835     int flags)
836 {
837 	if (len == 0)
838 		return;
839 
840 	/* Can't modify beyond end of packet. */
841 	/* TODO: Pad packet for this case. */
842 	if (offset + len > m->m_len)
843 		return;
844 
845 	bcopy(cp, mtod_off(m, offset, caddr_t), len);
846 }
847 
848 static void
849 ng_source_mod_counter(sc_p sc, struct ng_source_embed_cnt_info *cnt,
850     struct mbuf *m, int increment)
851 {
852 	caddr_t cp;
853 	uint32_t val;
854 
855 	val = htonl(cnt->next_val);
856 	cp = (caddr_t)&val + sizeof(val) - cnt->width;
857 	ng_source_packet_mod(sc, m, cnt->offset, cnt->width, cp, cnt->flags);
858 
859 	if (increment) {
860 		cnt->next_val += increment;
861 
862 		if (increment > 0 && cnt->next_val > cnt->max_val) {
863 			cnt->next_val = cnt->min_val - 1 +
864 			    (cnt->next_val - cnt->max_val);
865 			if (cnt->next_val > cnt->max_val)
866 				cnt->next_val = cnt->max_val;
867 		} else if (increment < 0 && cnt->next_val < cnt->min_val) {
868 			cnt->next_val = cnt->max_val + 1 +
869 			    (cnt->next_val - cnt->min_val);
870 			if (cnt->next_val < cnt->min_val)
871 				cnt->next_val = cnt->max_val;
872 		}
873 	}
874 }
875 
876 static int
877 ng_source_dup_mod(sc_p sc, struct mbuf *m0, struct mbuf **m_ptr)
878 {
879 	struct mbuf *m;
880 	struct ng_source_embed_cnt_info *cnt;
881 	struct ng_source_embed_info *ts;
882 	int modify;
883 	int error = 0;
884 	int i, increment;
885 
886 	/* Are we going to modify packets? */
887 	modify = sc->embed_timestamp.flags & NGM_SOURCE_EMBED_ENABLE;
888 	for (i = 0; !modify && i < NG_SOURCE_COUNTERS; ++i)
889 		modify = sc->embed_counter[i].flags & NGM_SOURCE_EMBED_ENABLE;
890 
891 	/* Duplicate the packet. */
892 	if (modify)
893 		m = m_dup(m0, M_NOWAIT);
894 	else
895 		m = m_copypacket(m0, M_NOWAIT);
896 	if (m == NULL) {
897 		error = ENOBUFS;
898 		goto done;
899 	}
900 	*m_ptr = m;
901 
902 	if (!modify)
903 		goto done;
904 
905 	/* Modify the copied packet for sending. */
906 	KASSERT(M_WRITABLE(m), ("%s: packet not writable", __func__));
907 
908 	for (i = 0; i < NG_SOURCE_COUNTERS; ++i) {
909 		cnt = &sc->embed_counter[i];
910 		if (cnt->flags & NGM_SOURCE_EMBED_ENABLE) {
911 			if ((cnt->flags & NGM_SOURCE_INC_CNT_PER_LIST) == 0 ||
912 			    sc->last_packet == m0)
913 				increment = cnt->increment;
914 			else
915 				increment = 0;
916 			ng_source_mod_counter(sc, cnt, m, increment);
917 		}
918 	}
919 
920 	ts = &sc->embed_timestamp;
921 	if (ts->flags & NGM_SOURCE_EMBED_ENABLE) {
922 		struct timeval now;
923 		getmicrotime(&now);
924 		now.tv_sec = htonl(now.tv_sec);
925 		now.tv_usec = htonl(now.tv_usec);
926 		ng_source_packet_mod(sc, m, ts->offset, sizeof (now),
927 		    (caddr_t)&now, ts->flags);
928 	}
929 
930 done:
931 	return(error);
932 }
933