xref: /freebsd/sys/netgraph/ng_source.c (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
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 <net/if_private.h>
72 #include <netgraph/ng_message.h>
73 #include <netgraph/netgraph.h>
74 #include <netgraph/ng_parse.h>
75 #include <netgraph/ng_ether.h>
76 #include <netgraph/ng_source.h>
77 
78 #define NG_SOURCE_INTR_TICKS		1
79 #define NG_SOURCE_DRIVER_IFQ_MAXLEN	(4*1024)
80 
81 #define	mtod_off(m,off,t)	((t)(mtod((m),caddr_t)+(off)))
82 
83 /* Per node info */
84 struct privdata {
85 	node_p				node;
86 	hook_p				input;
87 	hook_p				output;
88 	struct ng_source_stats		stats;
89 	struct mbufq			snd_queue;	/* packets to send */
90 	struct mbuf			*last_packet;	/* last pkt in queue */
91 	struct ifnet			*output_ifp;
92 	struct callout			intr_ch;
93 	uint64_t			packets;	/* packets to send */
94 	uint32_t			queueOctets;
95 	struct ng_source_embed_info	embed_timestamp;
96 	struct ng_source_embed_cnt_info	embed_counter[NG_SOURCE_COUNTERS];
97 };
98 typedef struct privdata *sc_p;
99 
100 /* Node flags */
101 #define NG_SOURCE_ACTIVE	(NGF_TYPE1)
102 
103 /* Netgraph methods */
104 static ng_constructor_t	ng_source_constructor;
105 static ng_rcvmsg_t	ng_source_rcvmsg;
106 static ng_shutdown_t	ng_source_rmnode;
107 static ng_newhook_t	ng_source_newhook;
108 static ng_connect_t	ng_source_connect;
109 static ng_rcvdata_t	ng_source_rcvdata;
110 static ng_disconnect_t	ng_source_disconnect;
111 
112 /* Other functions */
113 static void		ng_source_intr(node_p, hook_p, void *, int);
114 static void		ng_source_clr_data (sc_p);
115 static int		ng_source_start (sc_p, uint64_t);
116 static void		ng_source_stop (sc_p);
117 static int		ng_source_send (sc_p, int, int *);
118 static int		ng_source_store_output_ifp(sc_p, char *);
119 static void		ng_source_packet_mod(sc_p, struct mbuf *,
120 			    int, int, caddr_t, int);
121 static void		ng_source_mod_counter(sc_p sc,
122 			    struct ng_source_embed_cnt_info *cnt,
123 			    struct mbuf *m, int increment);
124 static int		ng_source_dup_mod(sc_p, struct mbuf *,
125 			    struct mbuf **);
126 
127 /* Parse type for timeval */
128 static const struct ng_parse_struct_field ng_source_timeval_type_fields[] = {
129 #ifdef __i386__
130 	{ "tv_sec",		&ng_parse_int32_type	},
131 #else
132 	{ "tv_sec",		&ng_parse_int64_type	},
133 #endif
134 #ifdef __LP64__
135 	{ "tv_usec",		&ng_parse_int64_type	},
136 #else
137 	{ "tv_usec",		&ng_parse_int32_type	},
138 #endif
139 	{ NULL }
140 };
141 const struct ng_parse_type ng_source_timeval_type = {
142 	&ng_parse_struct_type,
143 	&ng_source_timeval_type_fields
144 };
145 
146 /* Parse type for struct ng_source_stats */
147 static const struct ng_parse_struct_field ng_source_stats_type_fields[]
148 	= NG_SOURCE_STATS_TYPE_INFO;
149 static const struct ng_parse_type ng_source_stats_type = {
150 	&ng_parse_struct_type,
151 	&ng_source_stats_type_fields
152 };
153 
154 /* Parse type for struct ng_source_embed_info */
155 static const struct ng_parse_struct_field ng_source_embed_type_fields[] =
156 	NG_SOURCE_EMBED_TYPE_INFO;
157 static const struct ng_parse_type ng_source_embed_type = {
158 	&ng_parse_struct_type,
159 	&ng_source_embed_type_fields
160 };
161 
162 /* Parse type for struct ng_source_embed_cnt_info */
163 static const struct ng_parse_struct_field ng_source_embed_cnt_type_fields[] =
164 	NG_SOURCE_EMBED_CNT_TYPE_INFO;
165 static const struct ng_parse_type ng_source_embed_cnt_type = {
166 	&ng_parse_struct_type,
167 	&ng_source_embed_cnt_type_fields
168 };
169 
170 /* List of commands and how to convert arguments to/from ASCII */
171 static const struct ng_cmdlist ng_source_cmds[] = {
172 	{
173 	  NGM_SOURCE_COOKIE,
174 	  NGM_SOURCE_GET_STATS,
175 	  "getstats",
176 	  NULL,
177 	  &ng_source_stats_type
178 	},
179 	{
180 	  NGM_SOURCE_COOKIE,
181 	  NGM_SOURCE_CLR_STATS,
182 	  "clrstats",
183 	  NULL,
184 	  NULL
185 	},
186 	{
187 	  NGM_SOURCE_COOKIE,
188 	  NGM_SOURCE_GETCLR_STATS,
189 	  "getclrstats",
190 	  NULL,
191 	  &ng_source_stats_type
192 	},
193 	{
194 	  NGM_SOURCE_COOKIE,
195 	  NGM_SOURCE_START,
196 	  "start",
197 	  &ng_parse_uint64_type,
198 	  NULL
199 	},
200 	{
201 	  NGM_SOURCE_COOKIE,
202 	  NGM_SOURCE_STOP,
203 	  "stop",
204 	  NULL,
205 	  NULL
206 	},
207 	{
208 	  NGM_SOURCE_COOKIE,
209 	  NGM_SOURCE_CLR_DATA,
210 	  "clrdata",
211 	  NULL,
212 	  NULL
213 	},
214 	{
215 	  NGM_SOURCE_COOKIE,
216 	  NGM_SOURCE_SETIFACE,
217 	  "setiface",
218 	  &ng_parse_string_type,
219 	  NULL
220 	},
221 	{
222 	  NGM_SOURCE_COOKIE,
223 	  NGM_SOURCE_SETPPS,
224 	  "setpps",
225 	  &ng_parse_uint32_type,
226 	  NULL
227 	},
228 	{
229 	  NGM_SOURCE_COOKIE,
230 	  NGM_SOURCE_SET_TIMESTAMP,
231 	  "settimestamp",
232 	  &ng_source_embed_type,
233 	  NULL
234 	},
235 	{
236 	  NGM_SOURCE_COOKIE,
237 	  NGM_SOURCE_GET_TIMESTAMP,
238 	  "gettimestamp",
239 	  NULL,
240 	  &ng_source_embed_type
241 	},
242 	{
243 	  NGM_SOURCE_COOKIE,
244 	  NGM_SOURCE_SET_COUNTER,
245 	  "setcounter",
246 	  &ng_source_embed_cnt_type,
247 	  NULL
248 	},
249 	{
250 	  NGM_SOURCE_COOKIE,
251 	  NGM_SOURCE_GET_COUNTER,
252 	  "getcounter",
253 	  &ng_parse_uint8_type,
254 	  &ng_source_embed_cnt_type
255 	},
256 	{ 0 }
257 };
258 
259 /* Netgraph type descriptor */
260 static struct ng_type ng_source_typestruct = {
261 	.version =	NG_ABI_VERSION,
262 	.name =		NG_SOURCE_NODE_TYPE,
263 	.constructor =	ng_source_constructor,
264 	.rcvmsg =	ng_source_rcvmsg,
265 	.shutdown =	ng_source_rmnode,
266 	.newhook =	ng_source_newhook,
267 	.connect =	ng_source_connect,
268 	.rcvdata =	ng_source_rcvdata,
269 	.disconnect =	ng_source_disconnect,
270 	.cmdlist =	ng_source_cmds,
271 };
272 NETGRAPH_INIT(source, &ng_source_typestruct);
273 
274 static int ng_source_set_autosrc(sc_p, uint32_t);
275 
276 /*
277  * Node constructor
278  */
279 static int
280 ng_source_constructor(node_p node)
281 {
282 	sc_p sc;
283 
284 	sc = malloc(sizeof(*sc), M_NETGRAPH, M_WAITOK | M_ZERO);
285 
286 	NG_NODE_SET_PRIVATE(node, sc);
287 	sc->node = node;
288 	mbufq_init(&sc->snd_queue, 2048);
289 	ng_callout_init(&sc->intr_ch);
290 
291 	return (0);
292 }
293 
294 /*
295  * Add a hook
296  */
297 static int
298 ng_source_newhook(node_p node, hook_p hook, const char *name)
299 {
300 	sc_p sc = NG_NODE_PRIVATE(node);
301 
302 	if (strcmp(name, NG_SOURCE_HOOK_INPUT) == 0) {
303 		sc->input = hook;
304 	} else if (strcmp(name, NG_SOURCE_HOOK_OUTPUT) == 0) {
305 		sc->output = hook;
306 		sc->output_ifp = NULL;
307 		bzero(&sc->stats, sizeof(sc->stats));
308 	} else
309 		return (EINVAL);
310 
311 	return (0);
312 }
313 
314 /*
315  * Hook has been added
316  */
317 static int
318 ng_source_connect(hook_p hook)
319 {
320 	sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
321 	struct ng_mesg *msg;
322 	int dummy_error = 0;
323 
324 	/*
325 	 * If this is "output" hook, then request information
326 	 * from our downstream.
327 	 */
328 	if (hook == sc->output) {
329 		NG_MKMESSAGE(msg, NGM_ETHER_COOKIE, NGM_ETHER_GET_IFNAME,
330 		    0, M_NOWAIT);
331 		if (msg == NULL)
332 			return (ENOBUFS);
333 
334 		/*
335 		 * Our hook and peer hook have HK_INVALID flag set,
336 		 * so we can't use NG_SEND_MSG_HOOK() macro here.
337 		 */
338 		NG_SEND_MSG_ID(dummy_error, sc->node, msg,
339 		    NG_NODE_ID(NG_PEER_NODE(sc->output)), NG_NODE_ID(sc->node));
340 	}
341 
342 	return (0);
343 }
344 
345 /*
346  * Receive a control message
347  */
348 static int
349 ng_source_rcvmsg(node_p node, item_p item, hook_p lasthook)
350 {
351 	sc_p sc = NG_NODE_PRIVATE(node);
352 	struct ng_mesg *msg, *resp = NULL;
353 	int error = 0;
354 
355 	NGI_GET_MSG(item, msg);
356 
357 	switch (msg->header.typecookie) {
358 	case NGM_SOURCE_COOKIE:
359 		if (msg->header.flags & NGF_RESP) {
360 			error = EINVAL;
361 			break;
362 		}
363 		switch (msg->header.cmd) {
364 		case NGM_SOURCE_GET_STATS:
365 		case NGM_SOURCE_CLR_STATS:
366 		case NGM_SOURCE_GETCLR_STATS:
367                     {
368 			struct ng_source_stats *stats;
369 
370                         if (msg->header.cmd != NGM_SOURCE_CLR_STATS) {
371                                 NG_MKRESPONSE(resp, msg,
372                                     sizeof(*stats), M_NOWAIT);
373 				if (resp == NULL) {
374 					error = ENOMEM;
375 					goto done;
376 				}
377 				sc->stats.queueOctets = sc->queueOctets;
378 				sc->stats.queueFrames = mbufq_len(&sc->snd_queue);
379 				if ((sc->node->nd_flags & NG_SOURCE_ACTIVE)
380 				    && !timevalisset(&sc->stats.endTime)) {
381 					getmicrotime(&sc->stats.elapsedTime);
382 					timevalsub(&sc->stats.elapsedTime,
383 					    &sc->stats.startTime);
384 				}
385 				stats = (struct ng_source_stats *)resp->data;
386 				bcopy(&sc->stats, stats, sizeof(* stats));
387                         }
388                         if (msg->header.cmd != NGM_SOURCE_GET_STATS)
389 				bzero(&sc->stats, sizeof(sc->stats));
390 		    }
391 		    break;
392 		case NGM_SOURCE_START:
393 		    {
394 			uint64_t packets;
395 
396 			if (msg->header.arglen != sizeof(uint64_t)) {
397 				error = EINVAL;
398 				break;
399 			}
400 
401 			packets = *(uint64_t *)msg->data;
402 
403 			error = ng_source_start(sc, packets);
404 
405 		    	break;
406 		    }
407 		case NGM_SOURCE_STOP:
408 			ng_source_stop(sc);
409 			break;
410 		case NGM_SOURCE_CLR_DATA:
411 			ng_source_clr_data(sc);
412 			break;
413 		case NGM_SOURCE_SETIFACE:
414 		    {
415 			char *ifname = (char *)msg->data;
416 
417 			if (msg->header.arglen < 2) {
418 				error = EINVAL;
419 				break;
420 			}
421 
422 			ng_source_store_output_ifp(sc, ifname);
423 			break;
424 		    }
425 		case NGM_SOURCE_SETPPS:
426 		    {
427 			uint32_t pps;
428 
429 			if (msg->header.arglen != sizeof(uint32_t)) {
430 				error = EINVAL;
431 				break;
432 			}
433 
434 			pps = *(uint32_t *)msg->data;
435 
436 			sc->stats.maxPps = pps;
437 
438 			break;
439 		    }
440 		case NGM_SOURCE_SET_TIMESTAMP:
441 		    {
442 			struct ng_source_embed_info *embed;
443 
444 			if (msg->header.arglen != sizeof(*embed)) {
445 				error = EINVAL;
446 				goto done;
447 			}
448 			embed = (struct ng_source_embed_info *)msg->data;
449 			bcopy(embed, &sc->embed_timestamp, sizeof(*embed));
450 
451 			break;
452 		    }
453 		case NGM_SOURCE_GET_TIMESTAMP:
454 		    {
455 			struct ng_source_embed_info *embed;
456 
457 			NG_MKRESPONSE(resp, msg, sizeof(*embed), M_NOWAIT);
458 			if (resp == NULL) {
459 				error = ENOMEM;
460 				goto done;
461 			}
462 			embed = (struct ng_source_embed_info *)resp->data;
463 			bcopy(&sc->embed_timestamp, embed, sizeof(*embed));
464 
465 			break;
466 		    }
467 		case NGM_SOURCE_SET_COUNTER:
468 		    {
469 			struct ng_source_embed_cnt_info *embed;
470 
471 			if (msg->header.arglen != sizeof(*embed)) {
472 				error = EINVAL;
473 				goto done;
474 			}
475 			embed = (struct ng_source_embed_cnt_info *)msg->data;
476 			if (embed->index >= NG_SOURCE_COUNTERS ||
477 			    !(embed->width == 1 || embed->width == 2 ||
478 			    embed->width == 4)) {
479 				error = EINVAL;
480 				goto done;
481 			}
482 			bcopy(embed, &sc->embed_counter[embed->index],
483 			    sizeof(*embed));
484 
485 			break;
486 		    }
487 		case NGM_SOURCE_GET_COUNTER:
488 		    {
489 			uint8_t index = *(uint8_t *)msg->data;
490 			struct ng_source_embed_cnt_info *embed;
491 
492 			if (index >= NG_SOURCE_COUNTERS) {
493 				error = EINVAL;
494 				goto done;
495 			}
496 			NG_MKRESPONSE(resp, msg, sizeof(*embed), M_NOWAIT);
497 			if (resp == NULL) {
498 				error = ENOMEM;
499 				goto done;
500 			}
501 			embed = (struct ng_source_embed_cnt_info *)resp->data;
502 			bcopy(&sc->embed_counter[index], embed, sizeof(*embed));
503 
504 			break;
505 		    }
506 		default:
507 			error = EINVAL;
508 			break;
509 		}
510 		break;
511 	case NGM_ETHER_COOKIE:
512 		if (!(msg->header.flags & NGF_RESP)) {
513 			error = EINVAL;
514 			break;
515 		}
516 		switch (msg->header.cmd) {
517 		case NGM_ETHER_GET_IFNAME:
518 		    {
519 			char *ifname = (char *)msg->data;
520 
521 			if (msg->header.arglen < 2) {
522 				error = EINVAL;
523 				break;
524 			}
525 
526 			if (ng_source_store_output_ifp(sc, ifname) == 0)
527 				ng_source_set_autosrc(sc, 0);
528 			break;
529 		    }
530 		default:
531 			error = EINVAL;
532 		}
533 		break;
534 	default:
535 		error = EINVAL;
536 		break;
537 	}
538 
539 done:
540 	/* Take care of synchronous response, if any. */
541 	NG_RESPOND_MSG(error, node, item, resp);
542 	/* Free the message and return. */
543 	NG_FREE_MSG(msg);
544 	return (error);
545 }
546 
547 /*
548  * Receive data on a hook
549  *
550  * If data comes in the input hook, enqueue it on the send queue.
551  * If data comes in the output hook, discard it.
552  */
553 static int
554 ng_source_rcvdata(hook_p hook, item_p item)
555 {
556 	sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
557 	struct mbuf *m;
558 	int error = 0;
559 
560 	NGI_GET_M(item, m);
561 	NG_FREE_ITEM(item);
562 
563 	/* Which hook? */
564 	if (hook == sc->output) {
565 		/* discard */
566 		NG_FREE_M(m);
567 		return (error);
568 	}
569 	KASSERT(hook == sc->input, ("%s: no hook!", __func__));
570 
571 	/* Enqueue packet if the queue isn't full. */
572 	error = mbufq_enqueue(&sc->snd_queue, m);
573 	if (error) {
574 		NG_FREE_M(m);
575 		return (error);
576 	}
577 	sc->queueOctets += m->m_pkthdr.len;
578 	sc->last_packet = m;
579 
580 	return (0);
581 }
582 
583 /*
584  * Shutdown processing
585  */
586 static int
587 ng_source_rmnode(node_p node)
588 {
589 	sc_p sc = NG_NODE_PRIVATE(node);
590 
591 	ng_source_stop(sc);
592 	ng_source_clr_data(sc);
593 	NG_NODE_SET_PRIVATE(node, NULL);
594 	NG_NODE_UNREF(node);
595 	free(sc, M_NETGRAPH);
596 
597 	return (0);
598 }
599 
600 /*
601  * Hook disconnection
602  */
603 static int
604 ng_source_disconnect(hook_p hook)
605 {
606 	sc_p sc;
607 
608 	sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
609 	KASSERT(sc != NULL, ("%s: null node private", __func__));
610 	if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0 || hook == sc->output)
611 		ng_rmnode_self(NG_HOOK_NODE(hook));
612 	return (0);
613 }
614 
615 /*
616  * Set sc->output_ifp to point to the struct ifnet of the interface
617  * reached via our output hook.
618  */
619 static int
620 ng_source_store_output_ifp(sc_p sc, char *ifname)
621 {
622 	struct ifnet *ifp;
623 
624 	ifp = ifunit(ifname);
625 
626 	if (ifp == NULL) {
627 		printf("%s: can't find interface %s\n", __func__, ifname);
628 		return (EINVAL);
629 	}
630 	sc->output_ifp = ifp;
631 
632 #if 1
633 	/* XXX mucking with a drivers ifqueue size is ugly but we need it
634 	 * to queue a lot of packets to get close to line rate on a gigabit
635 	 * interface with small packets.
636 	 * XXX we should restore the original value at stop or disconnect
637 	 */
638 	if (ifp->if_snd.ifq_maxlen < NG_SOURCE_DRIVER_IFQ_MAXLEN) {
639 		printf("ng_source: changing ifq_maxlen from %d to %d\n",
640 		    ifp->if_snd.ifq_maxlen, NG_SOURCE_DRIVER_IFQ_MAXLEN);
641 		ifp->if_snd.ifq_maxlen = NG_SOURCE_DRIVER_IFQ_MAXLEN;
642 	}
643 #endif
644 	return (0);
645 }
646 
647 /*
648  * Set the attached ethernet node's ethernet source address override flag.
649  */
650 static int
651 ng_source_set_autosrc(sc_p sc, uint32_t flag)
652 {
653 	struct ng_mesg *msg;
654 	int error = 0;
655 
656 	NG_MKMESSAGE(msg, NGM_ETHER_COOKIE, NGM_ETHER_SET_AUTOSRC,
657 	    sizeof (uint32_t), M_NOWAIT);
658 	if (msg == NULL)
659 		return(ENOBUFS);
660 
661 	*(uint32_t *)msg->data = flag;
662 	NG_SEND_MSG_HOOK(error, sc->node, msg, sc->output, 0);
663 	return (error);
664 }
665 
666 /*
667  * Clear out the data we've queued
668  */
669 static void
670 ng_source_clr_data (sc_p sc)
671 {
672 	struct mbuf *m;
673 
674 	for (;;) {
675 		m =  mbufq_dequeue(&sc->snd_queue);
676 		if (m == NULL)
677 			break;
678 		NG_FREE_M(m);
679 	}
680 	sc->queueOctets = 0;
681 	sc->last_packet = NULL;
682 }
683 
684 /*
685  * Start sending queued data out the output hook
686  */
687 static int
688 ng_source_start(sc_p sc, uint64_t packets)
689 {
690 	if (sc->output_ifp == NULL && sc->stats.maxPps == 0) {
691 		printf("ng_source: start without iface or pps configured\n");
692 		return (ENXIO);
693 	}
694 
695 	if (sc->node->nd_flags & NG_SOURCE_ACTIVE)
696 		return (EBUSY);
697 
698 	sc->node->nd_flags |= NG_SOURCE_ACTIVE;
699 
700 	sc->packets = packets;
701 	timevalclear(&sc->stats.elapsedTime);
702 	timevalclear(&sc->stats.endTime);
703 	getmicrotime(&sc->stats.startTime);
704 	getmicrotime(&sc->stats.lastTime);
705 	ng_callout(&sc->intr_ch, sc->node, NULL, 0,
706 	    ng_source_intr, sc, 0);
707 
708 	return (0);
709 }
710 
711 /*
712  * Stop sending queued data out the output hook
713  */
714 static void
715 ng_source_stop(sc_p sc)
716 {
717 	ng_uncallout(&sc->intr_ch, sc->node);
718 	sc->node->nd_flags &= ~NG_SOURCE_ACTIVE;
719 	getmicrotime(&sc->stats.endTime);
720 	sc->stats.elapsedTime = sc->stats.endTime;
721 	timevalsub(&sc->stats.elapsedTime, &sc->stats.startTime);
722 }
723 
724 /*
725  * While active called every NG_SOURCE_INTR_TICKS ticks.
726  * Sends as many packets as the interface connected to our
727  * output hook is able to enqueue.
728  */
729 static void
730 ng_source_intr(node_p node, hook_p hook, void *arg1, int arg2)
731 {
732 	sc_p sc = (sc_p)arg1;
733 	struct ifqueue *ifq;
734 	int packets;
735 
736 	KASSERT(sc != NULL, ("%s: null node private", __func__));
737 
738 	if (sc->packets == 0 || sc->output == NULL
739 	    || (sc->node->nd_flags & NG_SOURCE_ACTIVE) == 0) {
740 		ng_source_stop(sc);
741 		return;
742 	}
743 
744 	if (sc->output_ifp != NULL) {
745 		ifq = (struct ifqueue *)&sc->output_ifp->if_snd;
746 		packets = ifq->ifq_maxlen - ifq->ifq_len;
747 	} else
748 		packets = mbufq_len(&sc->snd_queue);
749 
750 	if (sc->stats.maxPps != 0) {
751 		struct timeval	now, elapsed;
752 		uint64_t	usec;
753 		int		maxpkt;
754 
755 		getmicrotime(&now);
756 		elapsed = now;
757 		timevalsub(&elapsed, &sc->stats.lastTime);
758 		usec = elapsed.tv_sec * 1000000 + elapsed.tv_usec;
759 		maxpkt = (uint64_t)sc->stats.maxPps * usec / 1000000;
760 		sc->stats.lastTime = now;
761 		if (packets > maxpkt)
762 			packets = maxpkt;
763 	}
764 
765 	ng_source_send(sc, packets, NULL);
766 	if (sc->packets == 0)
767 		ng_source_stop(sc);
768 	else
769 		ng_callout(&sc->intr_ch, node, NULL, NG_SOURCE_INTR_TICKS,
770 		    ng_source_intr, sc, 0);
771 }
772 
773 /*
774  * Send packets out our output hook.
775  */
776 static int
777 ng_source_send(sc_p sc, int tosend, int *sent_p)
778 {
779 	struct mbuf *m, *m2;
780 	int sent;
781 	int error = 0;
782 
783 	KASSERT(tosend >= 0, ("%s: negative tosend param", __func__));
784 	KASSERT(sc->node->nd_flags & NG_SOURCE_ACTIVE,
785 	    ("%s: inactive node", __func__));
786 
787 	if ((uint64_t)tosend > sc->packets)
788 		tosend = sc->packets;
789 
790 	/* Go through the queue sending packets one by one. */
791 	for (sent = 0; error == 0 && sent < tosend; ++sent) {
792 		m = mbufq_dequeue(&sc->snd_queue);
793 		if (m == NULL)
794 			break;
795 
796 		/* Duplicate and modify the packet. */
797 		error = ng_source_dup_mod(sc, m, &m2);
798 		if (error) {
799 			if (error == ENOBUFS)
800 				mbufq_prepend(&sc->snd_queue, m);
801 			else
802 				(void)mbufq_enqueue(&sc->snd_queue, m);
803 			break;
804 		}
805 
806 		/*
807 		 * Re-enqueue the original packet for us.  The queue
808 		 * has a free slot, because we dequeued the packet
809 		 * above and this callout function runs under WRITER
810 		 * lock.
811 		 */
812 		error = mbufq_enqueue(&sc->snd_queue, m);
813 		KASSERT(error == 0, ("%s: re-enqueue packet failed", __func__));
814 
815 		sc->stats.outFrames++;
816 		sc->stats.outOctets += m2->m_pkthdr.len;
817 		NG_SEND_DATA_ONLY(error, sc->output, m2);
818 		if (error)
819 			break;
820 	}
821 
822 	sc->packets -= sent;
823 	if (sent_p != NULL)
824 		*sent_p = sent;
825 	return (error);
826 }
827 
828 /*
829  * Modify packet in 'm' by changing 'len' bytes starting at 'offset'
830  * to data in 'cp'.
831  *
832  * The packet data in 'm' must be in a contiguous buffer in a single mbuf.
833  */
834 static void
835 ng_source_packet_mod(sc_p sc, struct mbuf *m, int offset, int len, caddr_t cp,
836     int flags)
837 {
838 	if (len == 0)
839 		return;
840 
841 	/* Can't modify beyond end of packet. */
842 	/* TODO: Pad packet for this case. */
843 	if (offset + len > m->m_len)
844 		return;
845 
846 	bcopy(cp, mtod_off(m, offset, caddr_t), len);
847 }
848 
849 static void
850 ng_source_mod_counter(sc_p sc, struct ng_source_embed_cnt_info *cnt,
851     struct mbuf *m, int increment)
852 {
853 	caddr_t cp;
854 	uint32_t val;
855 
856 	val = htonl(cnt->next_val);
857 	cp = (caddr_t)&val + sizeof(val) - cnt->width;
858 	ng_source_packet_mod(sc, m, cnt->offset, cnt->width, cp, cnt->flags);
859 
860 	if (increment) {
861 		cnt->next_val += increment;
862 
863 		if (increment > 0 && cnt->next_val > cnt->max_val) {
864 			cnt->next_val = cnt->min_val - 1 +
865 			    (cnt->next_val - cnt->max_val);
866 			if (cnt->next_val > cnt->max_val)
867 				cnt->next_val = cnt->max_val;
868 		} else if (increment < 0 && cnt->next_val < cnt->min_val) {
869 			cnt->next_val = cnt->max_val + 1 +
870 			    (cnt->next_val - cnt->min_val);
871 			if (cnt->next_val < cnt->min_val)
872 				cnt->next_val = cnt->max_val;
873 		}
874 	}
875 }
876 
877 static int
878 ng_source_dup_mod(sc_p sc, struct mbuf *m0, struct mbuf **m_ptr)
879 {
880 	struct mbuf *m;
881 	struct ng_source_embed_cnt_info *cnt;
882 	struct ng_source_embed_info *ts;
883 	int modify;
884 	int error = 0;
885 	int i, increment;
886 
887 	/* Are we going to modify packets? */
888 	modify = sc->embed_timestamp.flags & NGM_SOURCE_EMBED_ENABLE;
889 	for (i = 0; !modify && i < NG_SOURCE_COUNTERS; ++i)
890 		modify = sc->embed_counter[i].flags & NGM_SOURCE_EMBED_ENABLE;
891 
892 	/* Duplicate the packet. */
893 	if (modify)
894 		m = m_dup(m0, M_NOWAIT);
895 	else
896 		m = m_copypacket(m0, M_NOWAIT);
897 	if (m == NULL) {
898 		error = ENOBUFS;
899 		goto done;
900 	}
901 	*m_ptr = m;
902 
903 	if (!modify)
904 		goto done;
905 
906 	/* Modify the copied packet for sending. */
907 	KASSERT(M_WRITABLE(m), ("%s: packet not writable", __func__));
908 
909 	for (i = 0; i < NG_SOURCE_COUNTERS; ++i) {
910 		cnt = &sc->embed_counter[i];
911 		if (cnt->flags & NGM_SOURCE_EMBED_ENABLE) {
912 			if ((cnt->flags & NGM_SOURCE_INC_CNT_PER_LIST) == 0 ||
913 			    sc->last_packet == m0)
914 				increment = cnt->increment;
915 			else
916 				increment = 0;
917 			ng_source_mod_counter(sc, cnt, m, increment);
918 		}
919 	}
920 
921 	ts = &sc->embed_timestamp;
922 	if (ts->flags & NGM_SOURCE_EMBED_ENABLE) {
923 		struct timeval now;
924 		getmicrotime(&now);
925 		now.tv_sec = htonl(now.tv_sec);
926 		now.tv_usec = htonl(now.tv_usec);
927 		ng_source_packet_mod(sc, m, ts->offset, sizeof (now),
928 		    (caddr_t)&now, ts->flags);
929 	}
930 
931 done:
932 	return(error);
933 }
934