xref: /freebsd/sys/netgraph/ng_source.c (revision 8ef24a0d4b28fe230e20637f56869cc4148cd2ca)
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 	{ "tv_sec",		&ng_parse_int32_type	},
129 	{ "tv_usec",		&ng_parse_int32_type	},
130 	{ NULL }
131 };
132 const struct ng_parse_type ng_source_timeval_type = {
133 	&ng_parse_struct_type,
134 	&ng_source_timeval_type_fields
135 };
136 
137 /* Parse type for struct ng_source_stats */
138 static const struct ng_parse_struct_field ng_source_stats_type_fields[]
139 	= NG_SOURCE_STATS_TYPE_INFO;
140 static const struct ng_parse_type ng_source_stats_type = {
141 	&ng_parse_struct_type,
142 	&ng_source_stats_type_fields
143 };
144 
145 /* Parse type for struct ng_source_embed_info */
146 static const struct ng_parse_struct_field ng_source_embed_type_fields[] =
147 	NG_SOURCE_EMBED_TYPE_INFO;
148 static const struct ng_parse_type ng_source_embed_type = {
149 	&ng_parse_struct_type,
150 	&ng_source_embed_type_fields
151 };
152 
153 /* Parse type for struct ng_source_embed_cnt_info */
154 static const struct ng_parse_struct_field ng_source_embed_cnt_type_fields[] =
155 	NG_SOURCE_EMBED_CNT_TYPE_INFO;
156 static const struct ng_parse_type ng_source_embed_cnt_type = {
157 	&ng_parse_struct_type,
158 	&ng_source_embed_cnt_type_fields
159 };
160 
161 /* List of commands and how to convert arguments to/from ASCII */
162 static const struct ng_cmdlist ng_source_cmds[] = {
163 	{
164 	  NGM_SOURCE_COOKIE,
165 	  NGM_SOURCE_GET_STATS,
166 	  "getstats",
167 	  NULL,
168 	  &ng_source_stats_type
169 	},
170 	{
171 	  NGM_SOURCE_COOKIE,
172 	  NGM_SOURCE_CLR_STATS,
173 	  "clrstats",
174 	  NULL,
175 	  NULL
176 	},
177 	{
178 	  NGM_SOURCE_COOKIE,
179 	  NGM_SOURCE_GETCLR_STATS,
180 	  "getclrstats",
181 	  NULL,
182 	  &ng_source_stats_type
183 	},
184 	{
185 	  NGM_SOURCE_COOKIE,
186 	  NGM_SOURCE_START,
187 	  "start",
188 	  &ng_parse_uint64_type,
189 	  NULL
190 	},
191 	{
192 	  NGM_SOURCE_COOKIE,
193 	  NGM_SOURCE_STOP,
194 	  "stop",
195 	  NULL,
196 	  NULL
197 	},
198 	{
199 	  NGM_SOURCE_COOKIE,
200 	  NGM_SOURCE_CLR_DATA,
201 	  "clrdata",
202 	  NULL,
203 	  NULL
204 	},
205 	{
206 	  NGM_SOURCE_COOKIE,
207 	  NGM_SOURCE_SETIFACE,
208 	  "setiface",
209 	  &ng_parse_string_type,
210 	  NULL
211 	},
212 	{
213 	  NGM_SOURCE_COOKIE,
214 	  NGM_SOURCE_SETPPS,
215 	  "setpps",
216 	  &ng_parse_uint32_type,
217 	  NULL
218 	},
219 	{
220 	  NGM_SOURCE_COOKIE,
221 	  NGM_SOURCE_SET_TIMESTAMP,
222 	  "settimestamp",
223 	  &ng_source_embed_type,
224 	  NULL
225 	},
226 	{
227 	  NGM_SOURCE_COOKIE,
228 	  NGM_SOURCE_GET_TIMESTAMP,
229 	  "gettimestamp",
230 	  NULL,
231 	  &ng_source_embed_type
232 	},
233 	{
234 	  NGM_SOURCE_COOKIE,
235 	  NGM_SOURCE_SET_COUNTER,
236 	  "setcounter",
237 	  &ng_source_embed_cnt_type,
238 	  NULL
239 	},
240 	{
241 	  NGM_SOURCE_COOKIE,
242 	  NGM_SOURCE_GET_COUNTER,
243 	  "getcounter",
244 	  &ng_parse_uint8_type,
245 	  &ng_source_embed_cnt_type
246 	},
247 	{ 0 }
248 };
249 
250 /* Netgraph type descriptor */
251 static struct ng_type ng_source_typestruct = {
252 	.version =	NG_ABI_VERSION,
253 	.name =		NG_SOURCE_NODE_TYPE,
254 	.constructor =	ng_source_constructor,
255 	.rcvmsg =	ng_source_rcvmsg,
256 	.shutdown =	ng_source_rmnode,
257 	.newhook =	ng_source_newhook,
258 	.connect =	ng_source_connect,
259 	.rcvdata =	ng_source_rcvdata,
260 	.disconnect =	ng_source_disconnect,
261 	.cmdlist =	ng_source_cmds,
262 };
263 NETGRAPH_INIT(source, &ng_source_typestruct);
264 
265 static int ng_source_set_autosrc(sc_p, uint32_t);
266 
267 /*
268  * Node constructor
269  */
270 static int
271 ng_source_constructor(node_p node)
272 {
273 	sc_p sc;
274 
275 	sc = malloc(sizeof(*sc), M_NETGRAPH, M_WAITOK | M_ZERO);
276 
277 	NG_NODE_SET_PRIVATE(node, sc);
278 	sc->node = node;
279 	sc->snd_queue.ifq_maxlen = 2048;	/* XXX not checked */
280 	ng_callout_init(&sc->intr_ch);
281 
282 	return (0);
283 }
284 
285 /*
286  * Add a hook
287  */
288 static int
289 ng_source_newhook(node_p node, hook_p hook, const char *name)
290 {
291 	sc_p sc = NG_NODE_PRIVATE(node);
292 
293 	if (strcmp(name, NG_SOURCE_HOOK_INPUT) == 0) {
294 		sc->input = hook;
295 	} else if (strcmp(name, NG_SOURCE_HOOK_OUTPUT) == 0) {
296 		sc->output = hook;
297 		sc->output_ifp = NULL;
298 		bzero(&sc->stats, sizeof(sc->stats));
299 	} else
300 		return (EINVAL);
301 
302 	return (0);
303 }
304 
305 /*
306  * Hook has been added
307  */
308 static int
309 ng_source_connect(hook_p hook)
310 {
311 	sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
312 	struct ng_mesg *msg;
313 	int dummy_error = 0;
314 
315 	/*
316 	 * If this is "output" hook, then request information
317 	 * from our downstream.
318 	 */
319 	if (hook == sc->output) {
320 		NG_MKMESSAGE(msg, NGM_ETHER_COOKIE, NGM_ETHER_GET_IFNAME,
321 		    0, M_NOWAIT);
322 		if (msg == NULL)
323 			return (ENOBUFS);
324 
325 		/*
326 		 * Our hook and peer hook have HK_INVALID flag set,
327 		 * so we can't use NG_SEND_MSG_HOOK() macro here.
328 		 */
329 		NG_SEND_MSG_ID(dummy_error, sc->node, msg,
330 		    NG_NODE_ID(NG_PEER_NODE(sc->output)), NG_NODE_ID(sc->node));
331 	}
332 
333 	return (0);
334 }
335 
336 /*
337  * Receive a control message
338  */
339 static int
340 ng_source_rcvmsg(node_p node, item_p item, hook_p lasthook)
341 {
342 	sc_p sc = NG_NODE_PRIVATE(node);
343 	struct ng_mesg *msg, *resp = NULL;
344 	int error = 0;
345 
346 	NGI_GET_MSG(item, msg);
347 
348 	switch (msg->header.typecookie) {
349 	case NGM_SOURCE_COOKIE:
350 		if (msg->header.flags & NGF_RESP) {
351 			error = EINVAL;
352 			break;
353 		}
354 		switch (msg->header.cmd) {
355 		case NGM_SOURCE_GET_STATS:
356 		case NGM_SOURCE_CLR_STATS:
357 		case NGM_SOURCE_GETCLR_STATS:
358                     {
359 			struct ng_source_stats *stats;
360 
361                         if (msg->header.cmd != NGM_SOURCE_CLR_STATS) {
362                                 NG_MKRESPONSE(resp, msg,
363                                     sizeof(*stats), M_NOWAIT);
364 				if (resp == NULL) {
365 					error = ENOMEM;
366 					goto done;
367 				}
368 				sc->stats.queueOctets = sc->queueOctets;
369 				sc->stats.queueFrames = sc->snd_queue.ifq_len;
370 				if ((sc->node->nd_flags & NG_SOURCE_ACTIVE)
371 				    && !timevalisset(&sc->stats.endTime)) {
372 					getmicrotime(&sc->stats.elapsedTime);
373 					timevalsub(&sc->stats.elapsedTime,
374 					    &sc->stats.startTime);
375 				}
376 				stats = (struct ng_source_stats *)resp->data;
377 				bcopy(&sc->stats, stats, sizeof(* stats));
378                         }
379                         if (msg->header.cmd != NGM_SOURCE_GET_STATS)
380 				bzero(&sc->stats, sizeof(sc->stats));
381 		    }
382 		    break;
383 		case NGM_SOURCE_START:
384 		    {
385 			uint64_t packets;
386 
387 			if (msg->header.arglen != sizeof(uint64_t)) {
388 				error = EINVAL;
389 				break;
390 			}
391 
392 			packets = *(uint64_t *)msg->data;
393 
394 			error = ng_source_start(sc, packets);
395 
396 		    	break;
397 		    }
398 		case NGM_SOURCE_STOP:
399 			ng_source_stop(sc);
400 			break;
401 		case NGM_SOURCE_CLR_DATA:
402 			ng_source_clr_data(sc);
403 			break;
404 		case NGM_SOURCE_SETIFACE:
405 		    {
406 			char *ifname = (char *)msg->data;
407 
408 			if (msg->header.arglen < 2) {
409 				error = EINVAL;
410 				break;
411 			}
412 
413 			ng_source_store_output_ifp(sc, ifname);
414 			break;
415 		    }
416 		case NGM_SOURCE_SETPPS:
417 		    {
418 			uint32_t pps;
419 
420 			if (msg->header.arglen != sizeof(uint32_t)) {
421 				error = EINVAL;
422 				break;
423 			}
424 
425 			pps = *(uint32_t *)msg->data;
426 
427 			sc->stats.maxPps = pps;
428 
429 			break;
430 		    }
431 		case NGM_SOURCE_SET_TIMESTAMP:
432 		    {
433 			struct ng_source_embed_info *embed;
434 
435 			if (msg->header.arglen != sizeof(*embed)) {
436 				error = EINVAL;
437 				goto done;
438 			}
439 			embed = (struct ng_source_embed_info *)msg->data;
440 			bcopy(embed, &sc->embed_timestamp, sizeof(*embed));
441 
442 			break;
443 		    }
444 		case NGM_SOURCE_GET_TIMESTAMP:
445 		    {
446 			struct ng_source_embed_info *embed;
447 
448 			NG_MKRESPONSE(resp, msg, sizeof(*embed), M_NOWAIT);
449 			if (resp == NULL) {
450 				error = ENOMEM;
451 				goto done;
452 			}
453 			embed = (struct ng_source_embed_info *)resp->data;
454 			bcopy(&sc->embed_timestamp, embed, sizeof(*embed));
455 
456 			break;
457 		    }
458 		case NGM_SOURCE_SET_COUNTER:
459 		    {
460 			struct ng_source_embed_cnt_info *embed;
461 
462 			if (msg->header.arglen != sizeof(*embed)) {
463 				error = EINVAL;
464 				goto done;
465 			}
466 			embed = (struct ng_source_embed_cnt_info *)msg->data;
467 			if (embed->index >= NG_SOURCE_COUNTERS ||
468 			    !(embed->width == 1 || embed->width == 2 ||
469 			    embed->width == 4)) {
470 				error = EINVAL;
471 				goto done;
472 			}
473 			bcopy(embed, &sc->embed_counter[embed->index],
474 			    sizeof(*embed));
475 
476 			break;
477 		    }
478 		case NGM_SOURCE_GET_COUNTER:
479 		    {
480 			uint8_t index = *(uint8_t *)msg->data;
481 			struct ng_source_embed_cnt_info *embed;
482 
483 			if (index >= NG_SOURCE_COUNTERS) {
484 				error = EINVAL;
485 				goto done;
486 			}
487 			NG_MKRESPONSE(resp, msg, sizeof(*embed), M_NOWAIT);
488 			if (resp == NULL) {
489 				error = ENOMEM;
490 				goto done;
491 			}
492 			embed = (struct ng_source_embed_cnt_info *)resp->data;
493 			bcopy(&sc->embed_counter[index], embed, sizeof(*embed));
494 
495 			break;
496 		    }
497 		default:
498 			error = EINVAL;
499 			break;
500 		}
501 		break;
502 	case NGM_ETHER_COOKIE:
503 		if (!(msg->header.flags & NGF_RESP)) {
504 			error = EINVAL;
505 			break;
506 		}
507 		switch (msg->header.cmd) {
508 		case NGM_ETHER_GET_IFNAME:
509 		    {
510 			char *ifname = (char *)msg->data;
511 
512 			if (msg->header.arglen < 2) {
513 				error = EINVAL;
514 				break;
515 			}
516 
517 			if (ng_source_store_output_ifp(sc, ifname) == 0)
518 				ng_source_set_autosrc(sc, 0);
519 			break;
520 		    }
521 		default:
522 			error = EINVAL;
523 		}
524 		break;
525 	default:
526 		error = EINVAL;
527 		break;
528 	}
529 
530 done:
531 	/* Take care of synchronous response, if any. */
532 	NG_RESPOND_MSG(error, node, item, resp);
533 	/* Free the message and return. */
534 	NG_FREE_MSG(msg);
535 	return (error);
536 }
537 
538 /*
539  * Receive data on a hook
540  *
541  * If data comes in the input hook, enqueue it on the send queue.
542  * If data comes in the output hook, discard it.
543  */
544 static int
545 ng_source_rcvdata(hook_p hook, item_p item)
546 {
547 	sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
548 	struct mbuf *m;
549 	int error = 0;
550 
551 	NGI_GET_M(item, m);
552 	NG_FREE_ITEM(item);
553 
554 	/* Which hook? */
555 	if (hook == sc->output) {
556 		/* discard */
557 		NG_FREE_M(m);
558 		return (error);
559 	}
560 	KASSERT(hook == sc->input, ("%s: no hook!", __func__));
561 
562 	/* Enqueue packet. */
563 	/* XXX should we check IF_QFULL() ? */
564 	_IF_ENQUEUE(&sc->snd_queue, m);
565 	sc->queueOctets += m->m_pkthdr.len;
566 	sc->last_packet = m;
567 
568 	return (0);
569 }
570 
571 /*
572  * Shutdown processing
573  */
574 static int
575 ng_source_rmnode(node_p node)
576 {
577 	sc_p sc = NG_NODE_PRIVATE(node);
578 
579 	ng_source_stop(sc);
580 	ng_source_clr_data(sc);
581 	NG_NODE_SET_PRIVATE(node, NULL);
582 	NG_NODE_UNREF(node);
583 	free(sc, M_NETGRAPH);
584 
585 	return (0);
586 }
587 
588 /*
589  * Hook disconnection
590  */
591 static int
592 ng_source_disconnect(hook_p hook)
593 {
594 	sc_p sc;
595 
596 	sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
597 	KASSERT(sc != NULL, ("%s: null node private", __func__));
598 	if (NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0 || hook == sc->output)
599 		ng_rmnode_self(NG_HOOK_NODE(hook));
600 	return (0);
601 }
602 
603 /*
604  * Set sc->output_ifp to point to the struct ifnet of the interface
605  * reached via our output hook.
606  */
607 static int
608 ng_source_store_output_ifp(sc_p sc, char *ifname)
609 {
610 	struct ifnet *ifp;
611 
612 	ifp = ifunit(ifname);
613 
614 	if (ifp == NULL) {
615 		printf("%s: can't find interface %s\n", __func__, ifname);
616 		return (EINVAL);
617 	}
618 	sc->output_ifp = ifp;
619 
620 #if 1
621 	/* XXX mucking with a drivers ifqueue size is ugly but we need it
622 	 * to queue a lot of packets to get close to line rate on a gigabit
623 	 * interface with small packets.
624 	 * XXX we should restore the original value at stop or disconnect
625 	 */
626 	if (ifp->if_snd.ifq_maxlen < NG_SOURCE_DRIVER_IFQ_MAXLEN) {
627 		printf("ng_source: changing ifq_maxlen from %d to %d\n",
628 		    ifp->if_snd.ifq_maxlen, NG_SOURCE_DRIVER_IFQ_MAXLEN);
629 		ifp->if_snd.ifq_maxlen = NG_SOURCE_DRIVER_IFQ_MAXLEN;
630 	}
631 #endif
632 	return (0);
633 }
634 
635 /*
636  * Set the attached ethernet node's ethernet source address override flag.
637  */
638 static int
639 ng_source_set_autosrc(sc_p sc, uint32_t flag)
640 {
641 	struct ng_mesg *msg;
642 	int error = 0;
643 
644 	NG_MKMESSAGE(msg, NGM_ETHER_COOKIE, NGM_ETHER_SET_AUTOSRC,
645 	    sizeof (uint32_t), M_NOWAIT);
646 	if (msg == NULL)
647 		return(ENOBUFS);
648 
649 	*(uint32_t *)msg->data = flag;
650 	NG_SEND_MSG_HOOK(error, sc->node, msg, sc->output, 0);
651 	return (error);
652 }
653 
654 /*
655  * Clear out the data we've queued
656  */
657 static void
658 ng_source_clr_data (sc_p sc)
659 {
660 	struct mbuf *m;
661 
662 	for (;;) {
663 		_IF_DEQUEUE(&sc->snd_queue, m);
664 		if (m == NULL)
665 			break;
666 		NG_FREE_M(m);
667 	}
668 	sc->queueOctets = 0;
669 	sc->last_packet = NULL;
670 }
671 
672 /*
673  * Start sending queued data out the output hook
674  */
675 static int
676 ng_source_start(sc_p sc, uint64_t packets)
677 {
678 	if (sc->output_ifp == NULL) {
679 		printf("ng_source: start without iface configured\n");
680 		return (ENXIO);
681 	}
682 
683 	if (sc->node->nd_flags & NG_SOURCE_ACTIVE)
684 		return (EBUSY);
685 
686 	sc->node->nd_flags |= NG_SOURCE_ACTIVE;
687 
688 	sc->packets = packets;
689 	timevalclear(&sc->stats.elapsedTime);
690 	timevalclear(&sc->stats.endTime);
691 	getmicrotime(&sc->stats.startTime);
692 	getmicrotime(&sc->stats.lastTime);
693 	ng_callout(&sc->intr_ch, sc->node, NULL, 0,
694 	    ng_source_intr, sc, 0);
695 
696 	return (0);
697 }
698 
699 /*
700  * Stop sending queued data out the output hook
701  */
702 static void
703 ng_source_stop(sc_p sc)
704 {
705 	ng_uncallout(&sc->intr_ch, sc->node);
706 	sc->node->nd_flags &= ~NG_SOURCE_ACTIVE;
707 	getmicrotime(&sc->stats.endTime);
708 	sc->stats.elapsedTime = sc->stats.endTime;
709 	timevalsub(&sc->stats.elapsedTime, &sc->stats.startTime);
710 }
711 
712 /*
713  * While active called every NG_SOURCE_INTR_TICKS ticks.
714  * Sends as many packets as the interface connected to our
715  * output hook is able to enqueue.
716  */
717 static void
718 ng_source_intr(node_p node, hook_p hook, void *arg1, int arg2)
719 {
720 	sc_p sc = (sc_p)arg1;
721 	struct ifqueue *ifq;
722 	int packets;
723 
724 	KASSERT(sc != NULL, ("%s: null node private", __func__));
725 
726 	if (sc->packets == 0 || sc->output == NULL
727 	    || (sc->node->nd_flags & NG_SOURCE_ACTIVE) == 0) {
728 		ng_source_stop(sc);
729 		return;
730 	}
731 
732 	if (sc->output_ifp != NULL) {
733 		ifq = (struct ifqueue *)&sc->output_ifp->if_snd;
734 		packets = ifq->ifq_maxlen - ifq->ifq_len;
735 	} else
736 		packets = sc->snd_queue.ifq_len;
737 
738 	if (sc->stats.maxPps != 0) {
739 		struct timeval	now, elapsed;
740 		uint64_t	usec;
741 		int		maxpkt;
742 
743 		getmicrotime(&now);
744 		elapsed = now;
745 		timevalsub(&elapsed, &sc->stats.lastTime);
746 		usec = elapsed.tv_sec * 1000000 + elapsed.tv_usec;
747 		maxpkt = (uint64_t)sc->stats.maxPps * usec / 1000000;
748 		sc->stats.lastTime = now;
749 		if (packets > maxpkt)
750 			packets = maxpkt;
751 	}
752 
753 	ng_source_send(sc, packets, NULL);
754 	if (sc->packets == 0)
755 		ng_source_stop(sc);
756 	else
757 		ng_callout(&sc->intr_ch, node, NULL, NG_SOURCE_INTR_TICKS,
758 		    ng_source_intr, sc, 0);
759 }
760 
761 /*
762  * Send packets out our output hook.
763  */
764 static int
765 ng_source_send(sc_p sc, int tosend, int *sent_p)
766 {
767 	struct mbuf *m, *m2;
768 	int sent;
769 	int error = 0;
770 
771 	KASSERT(tosend >= 0, ("%s: negative tosend param", __func__));
772 	KASSERT(sc->node->nd_flags & NG_SOURCE_ACTIVE,
773 	    ("%s: inactive node", __func__));
774 
775 	if ((uint64_t)tosend > sc->packets)
776 		tosend = sc->packets;
777 
778 	/* Go through the queue sending packets one by one. */
779 	for (sent = 0; error == 0 && sent < tosend; ++sent) {
780 		_IF_DEQUEUE(&sc->snd_queue, m);
781 		if (m == NULL)
782 			break;
783 
784 		/* Duplicate and modify the packet. */
785 		error = ng_source_dup_mod(sc, m, &m2);
786 		if (error) {
787 			if (error == ENOBUFS)
788 				_IF_PREPEND(&sc->snd_queue, m);
789 			else
790 				_IF_ENQUEUE(&sc->snd_queue, m);
791 			break;
792 		}
793 
794 		/* Re-enqueue the original packet for us. */
795 		_IF_ENQUEUE(&sc->snd_queue, m);
796 
797 		sc->stats.outFrames++;
798 		sc->stats.outOctets += m2->m_pkthdr.len;
799 		NG_SEND_DATA_ONLY(error, sc->output, m2);
800 		if (error)
801 			break;
802 	}
803 
804 	sc->packets -= sent;
805 	if (sent_p != NULL)
806 		*sent_p = sent;
807 	return (error);
808 }
809 
810 /*
811  * Modify packet in 'm' by changing 'len' bytes starting at 'offset'
812  * to data in 'cp'.
813  *
814  * The packet data in 'm' must be in a contiguous buffer in a single mbuf.
815  */
816 static void
817 ng_source_packet_mod(sc_p sc, struct mbuf *m, int offset, int len, caddr_t cp,
818     int flags)
819 {
820 	if (len == 0)
821 		return;
822 
823 	/* Can't modify beyond end of packet. */
824 	/* TODO: Pad packet for this case. */
825 	if (offset + len > m->m_len)
826 		return;
827 
828 	bcopy(cp, mtod_off(m, offset, caddr_t), len);
829 }
830 
831 static void
832 ng_source_mod_counter(sc_p sc, struct ng_source_embed_cnt_info *cnt,
833     struct mbuf *m, int increment)
834 {
835 	caddr_t cp;
836 	uint32_t val;
837 
838 	val = htonl(cnt->next_val);
839 	cp = (caddr_t)&val + sizeof(val) - cnt->width;
840 	ng_source_packet_mod(sc, m, cnt->offset, cnt->width, cp, cnt->flags);
841 
842 	if (increment) {
843 		cnt->next_val += increment;
844 
845 		if (increment > 0 && cnt->next_val > cnt->max_val) {
846 			cnt->next_val = cnt->min_val - 1 +
847 			    (cnt->next_val - cnt->max_val);
848 			if (cnt->next_val > cnt->max_val)
849 				cnt->next_val = cnt->max_val;
850 		} else if (increment < 0 && cnt->next_val < cnt->min_val) {
851 			cnt->next_val = cnt->max_val + 1 +
852 			    (cnt->next_val - cnt->min_val);
853 			if (cnt->next_val < cnt->min_val)
854 				cnt->next_val = cnt->max_val;
855 		}
856 	}
857 }
858 
859 static int
860 ng_source_dup_mod(sc_p sc, struct mbuf *m0, struct mbuf **m_ptr)
861 {
862 	struct mbuf *m;
863 	struct ng_source_embed_cnt_info *cnt;
864 	struct ng_source_embed_info *ts;
865 	int modify;
866 	int error = 0;
867 	int i, increment;
868 
869 	/* Are we going to modify packets? */
870 	modify = sc->embed_timestamp.flags & NGM_SOURCE_EMBED_ENABLE;
871 	for (i = 0; !modify && i < NG_SOURCE_COUNTERS; ++i)
872 		modify = sc->embed_counter[i].flags & NGM_SOURCE_EMBED_ENABLE;
873 
874 	/* Duplicate the packet. */
875 	if (modify)
876 		m = m_dup(m0, M_NOWAIT);
877 	else
878 		m = m_copypacket(m0, M_NOWAIT);
879 	if (m == NULL) {
880 		error = ENOBUFS;
881 		goto done;
882 	}
883 	*m_ptr = m;
884 
885 	if (!modify)
886 		goto done;
887 
888 	/* Modify the copied packet for sending. */
889 	KASSERT(M_WRITABLE(m), ("%s: packet not writable", __func__));
890 
891 	for (i = 0; i < NG_SOURCE_COUNTERS; ++i) {
892 		cnt = &sc->embed_counter[i];
893 		if (cnt->flags & NGM_SOURCE_EMBED_ENABLE) {
894 			if ((cnt->flags & NGM_SOURCE_INC_CNT_PER_LIST) == 0 ||
895 			    sc->last_packet == m0)
896 				increment = cnt->increment;
897 			else
898 				increment = 0;
899 			ng_source_mod_counter(sc, cnt, m, increment);
900 		}
901 	}
902 
903 	ts = &sc->embed_timestamp;
904 	if (ts->flags & NGM_SOURCE_EMBED_ENABLE) {
905 		struct timeval now;
906 		getmicrotime(&now);
907 		now.tv_sec = htonl(now.tv_sec);
908 		now.tv_usec = htonl(now.tv_usec);
909 		ng_source_packet_mod(sc, m, ts->offset, sizeof (now),
910 		    (caddr_t)&now, ts->flags);
911 	}
912 
913 done:
914 	return(error);
915 }
916