1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2004-2010 University of Zagreb
5 * Copyright (c) 2007-2008 FreeBSD Foundation
6 *
7 * This software was developed by the University of Zagreb and the
8 * FreeBSD Foundation under sponsorship by the Stichting NLnet and the
9 * FreeBSD Foundation.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * $FreeBSD$
33 */
34
35/*
36 * This node permits simple traffic shaping by emulating bandwidth
37 * and delay, as well as random packet losses.
38 * The node has two hooks, upper and lower. Traffic flowing from upper to
39 * lower hook is referenced as downstream, and vice versa. Parameters for
40 * both directions can be set separately, except for delay.
41 */
42
43#include <sys/param.h>
44#include <sys/errno.h>
45#include <sys/systm.h>
46#include <sys/kernel.h>
47#include <sys/malloc.h>
48#include <sys/mbuf.h>
49#include <sys/time.h>
50
51#include <vm/uma.h>
52
53#include <net/vnet.h>
54
55#include <netinet/in.h>
56#include <netinet/in_systm.h>
57#include <netinet/ip.h>
58
59#include <netgraph/ng_message.h>
60#include <netgraph/netgraph.h>
61#include <netgraph/ng_parse.h>
62#include <netgraph/ng_pipe.h>
63
64static MALLOC_DEFINE(M_NG_PIPE, "ng_pipe", "ng_pipe");
65
66/* Packet header struct */
67struct ngp_hdr {
68	TAILQ_ENTRY(ngp_hdr)	ngp_link;	/* next pkt in queue */
69	struct timeval		when;		/* this packet's due time */
70	struct mbuf		*m;		/* ptr to the packet data */
71};
72TAILQ_HEAD(p_head, ngp_hdr);
73
74/* FIFO queue struct */
75struct ngp_fifo {
76	TAILQ_ENTRY(ngp_fifo)	fifo_le;	/* list of active queues only */
77	struct p_head		packet_head;	/* FIFO queue head */
78	u_int32_t		hash;		/* flow signature */
79	struct timeval		vtime;		/* virtual time, for WFQ */
80	u_int32_t		rr_deficit;	/* for DRR */
81	u_int32_t		packets;	/* # of packets in this queue */
82};
83
84/* Per hook info */
85struct hookinfo {
86	hook_p			hook;
87	int			noqueue;	/* bypass any processing */
88	TAILQ_HEAD(, ngp_fifo)	fifo_head;	/* FIFO queues */
89	TAILQ_HEAD(, ngp_hdr)	qout_head;	/* delay queue head */
90	struct timeval		qin_utime;
91	struct ng_pipe_hookcfg	cfg;
92	struct ng_pipe_hookrun	run;
93	struct ng_pipe_hookstat	stats;
94	uint64_t		*ber_p;		/* loss_p(BER,psize) map */
95};
96
97/* Per node info */
98struct node_priv {
99	u_int64_t		delay;
100	u_int32_t		overhead;
101	u_int32_t		header_offset;
102	struct hookinfo		lower;
103	struct hookinfo		upper;
104	struct callout		timer;
105	int			timer_scheduled;
106};
107typedef struct node_priv *priv_p;
108
109/* Macro for calculating the virtual time for packet dequeueing in WFQ */
110#define FIFO_VTIME_SORT(plen)						\
111	if (hinfo->cfg.wfq && hinfo->cfg.bandwidth) {			\
112		ngp_f->vtime.tv_usec = now->tv_usec + ((uint64_t) (plen) \
113			+ priv->overhead ) * hinfo->run.fifo_queues *	\
114			8000000 / hinfo->cfg.bandwidth;			\
115		ngp_f->vtime.tv_sec = now->tv_sec +			\
116			ngp_f->vtime.tv_usec / 1000000;			\
117		ngp_f->vtime.tv_usec = ngp_f->vtime.tv_usec % 1000000;	\
118		TAILQ_FOREACH(ngp_f1, &hinfo->fifo_head, fifo_le)	\
119			if (ngp_f1->vtime.tv_sec > ngp_f->vtime.tv_sec || \
120			    (ngp_f1->vtime.tv_sec == ngp_f->vtime.tv_sec && \
121			    ngp_f1->vtime.tv_usec > ngp_f->vtime.tv_usec)) \
122				break;					\
123		if (ngp_f1 == NULL)					\
124			TAILQ_INSERT_TAIL(&hinfo->fifo_head, ngp_f, fifo_le); \
125		else							\
126			TAILQ_INSERT_BEFORE(ngp_f1, ngp_f, fifo_le);	\
127	} else								\
128		TAILQ_INSERT_TAIL(&hinfo->fifo_head, ngp_f, fifo_le);	\
129
130static void	parse_cfg(struct ng_pipe_hookcfg *, struct ng_pipe_hookcfg *,
131			struct hookinfo *, priv_p);
132static void	pipe_dequeue(struct hookinfo *, struct timeval *);
133static void	ngp_callout(node_p, hook_p, void *, int);
134static int	ngp_modevent(module_t, int, void *);
135
136/* zone for storing ngp_hdr-s */
137static uma_zone_t ngp_zone;
138
139/* Netgraph methods */
140static ng_constructor_t	ngp_constructor;
141static ng_rcvmsg_t	ngp_rcvmsg;
142static ng_shutdown_t	ngp_shutdown;
143static ng_newhook_t	ngp_newhook;
144static ng_rcvdata_t	ngp_rcvdata;
145static ng_disconnect_t	ngp_disconnect;
146
147/* Parse type for struct ng_pipe_hookstat */
148static const struct ng_parse_struct_field
149	ng_pipe_hookstat_type_fields[] = NG_PIPE_HOOKSTAT_INFO;
150static const struct ng_parse_type ng_pipe_hookstat_type = {
151	&ng_parse_struct_type,
152	&ng_pipe_hookstat_type_fields
153};
154
155/* Parse type for struct ng_pipe_stats */
156static const struct ng_parse_struct_field ng_pipe_stats_type_fields[] =
157	NG_PIPE_STATS_INFO(&ng_pipe_hookstat_type);
158static const struct ng_parse_type ng_pipe_stats_type = {
159	&ng_parse_struct_type,
160	&ng_pipe_stats_type_fields
161};
162
163/* Parse type for struct ng_pipe_hookrun */
164static const struct ng_parse_struct_field
165	ng_pipe_hookrun_type_fields[] = NG_PIPE_HOOKRUN_INFO;
166static const struct ng_parse_type ng_pipe_hookrun_type = {
167	&ng_parse_struct_type,
168	&ng_pipe_hookrun_type_fields
169};
170
171/* Parse type for struct ng_pipe_run */
172static const struct ng_parse_struct_field
173	ng_pipe_run_type_fields[] = NG_PIPE_RUN_INFO(&ng_pipe_hookrun_type);
174static const struct ng_parse_type ng_pipe_run_type = {
175	&ng_parse_struct_type,
176	&ng_pipe_run_type_fields
177};
178
179/* Parse type for struct ng_pipe_hookcfg */
180static const struct ng_parse_struct_field
181	ng_pipe_hookcfg_type_fields[] = NG_PIPE_HOOKCFG_INFO;
182static const struct ng_parse_type ng_pipe_hookcfg_type = {
183	&ng_parse_struct_type,
184	&ng_pipe_hookcfg_type_fields
185};
186
187/* Parse type for struct ng_pipe_cfg */
188static const struct ng_parse_struct_field
189	ng_pipe_cfg_type_fields[] = NG_PIPE_CFG_INFO(&ng_pipe_hookcfg_type);
190static const struct ng_parse_type ng_pipe_cfg_type = {
191	&ng_parse_struct_type,
192	&ng_pipe_cfg_type_fields
193};
194
195/* List of commands and how to convert arguments to/from ASCII */
196static const struct ng_cmdlist ngp_cmds[] = {
197	{
198		.cookie =	NGM_PIPE_COOKIE,
199		.cmd =		NGM_PIPE_GET_STATS,
200		.name = 	"getstats",
201		.respType =	 &ng_pipe_stats_type
202	},
203	{
204		.cookie =	NGM_PIPE_COOKIE,
205		.cmd =		NGM_PIPE_CLR_STATS,
206		.name =		"clrstats"
207	},
208	{
209		.cookie =	NGM_PIPE_COOKIE,
210		.cmd =		NGM_PIPE_GETCLR_STATS,
211		.name =		"getclrstats",
212		.respType =	&ng_pipe_stats_type
213	},
214	{
215		.cookie =	NGM_PIPE_COOKIE,
216		.cmd =		NGM_PIPE_GET_RUN,
217		.name =		"getrun",
218		.respType =	&ng_pipe_run_type
219	},
220	{
221		.cookie =	NGM_PIPE_COOKIE,
222		.cmd =		NGM_PIPE_GET_CFG,
223		.name =		"getcfg",
224		.respType =	&ng_pipe_cfg_type
225	},
226	{
227		.cookie =	NGM_PIPE_COOKIE,
228		.cmd =		NGM_PIPE_SET_CFG,
229		.name =		"setcfg",
230		.mesgType =	&ng_pipe_cfg_type,
231	},
232	{ 0 }
233};
234
235/* Netgraph type descriptor */
236static struct ng_type ng_pipe_typestruct = {
237	.version =	NG_ABI_VERSION,
238	.name =		NG_PIPE_NODE_TYPE,
239	.mod_event =	ngp_modevent,
240	.constructor =	ngp_constructor,
241	.shutdown =	ngp_shutdown,
242	.rcvmsg =	ngp_rcvmsg,
243	.newhook =	ngp_newhook,
244	.rcvdata =	ngp_rcvdata,
245	.disconnect =	ngp_disconnect,
246	.cmdlist =	ngp_cmds
247};
248NETGRAPH_INIT(pipe, &ng_pipe_typestruct);
249
250/* Node constructor */
251static int
252ngp_constructor(node_p node)
253{
254	priv_p priv;
255
256	priv = malloc(sizeof(*priv), M_NG_PIPE, M_ZERO | M_WAITOK);
257	NG_NODE_SET_PRIVATE(node, priv);
258
259	/* Mark node as single-threaded */
260	NG_NODE_FORCE_WRITER(node);
261
262	ng_callout_init(&priv->timer);
263
264	return (0);
265}
266
267/* Add a hook */
268static int
269ngp_newhook(node_p node, hook_p hook, const char *name)
270{
271	const priv_p priv = NG_NODE_PRIVATE(node);
272	struct hookinfo *hinfo;
273
274	if (strcmp(name, NG_PIPE_HOOK_UPPER) == 0) {
275		bzero(&priv->upper, sizeof(priv->upper));
276		priv->upper.hook = hook;
277		NG_HOOK_SET_PRIVATE(hook, &priv->upper);
278	} else if (strcmp(name, NG_PIPE_HOOK_LOWER) == 0) {
279		bzero(&priv->lower, sizeof(priv->lower));
280		priv->lower.hook = hook;
281		NG_HOOK_SET_PRIVATE(hook, &priv->lower);
282	} else
283		return (EINVAL);
284
285	/* Load non-zero initial cfg values */
286	hinfo = NG_HOOK_PRIVATE(hook);
287	hinfo->cfg.qin_size_limit = 50;
288	hinfo->cfg.fifo = 1;
289	hinfo->cfg.droptail = 1;
290	TAILQ_INIT(&hinfo->fifo_head);
291	TAILQ_INIT(&hinfo->qout_head);
292	return (0);
293}
294
295/* Receive a control message */
296static int
297ngp_rcvmsg(node_p node, item_p item, hook_p lasthook)
298{
299	const priv_p priv = NG_NODE_PRIVATE(node);
300	struct ng_mesg *resp = NULL;
301	struct ng_mesg *msg, *flow_msg;
302	struct ng_pipe_stats *stats;
303	struct ng_pipe_run *run;
304	struct ng_pipe_cfg *cfg;
305	int error = 0;
306	int prev_down, now_down, cmd;
307
308	NGI_GET_MSG(item, msg);
309	switch (msg->header.typecookie) {
310	case NGM_PIPE_COOKIE:
311		switch (msg->header.cmd) {
312		case NGM_PIPE_GET_STATS:
313		case NGM_PIPE_CLR_STATS:
314		case NGM_PIPE_GETCLR_STATS:
315			if (msg->header.cmd != NGM_PIPE_CLR_STATS) {
316				NG_MKRESPONSE(resp, msg,
317				    sizeof(*stats), M_NOWAIT);
318				if (resp == NULL) {
319					error = ENOMEM;
320					break;
321				}
322				stats = (struct ng_pipe_stats *) resp->data;
323				bcopy(&priv->upper.stats, &stats->downstream,
324				    sizeof(stats->downstream));
325				bcopy(&priv->lower.stats, &stats->upstream,
326				    sizeof(stats->upstream));
327			}
328			if (msg->header.cmd != NGM_PIPE_GET_STATS) {
329				bzero(&priv->upper.stats,
330				    sizeof(priv->upper.stats));
331				bzero(&priv->lower.stats,
332				    sizeof(priv->lower.stats));
333			}
334			break;
335		case NGM_PIPE_GET_RUN:
336			NG_MKRESPONSE(resp, msg, sizeof(*run), M_NOWAIT);
337			if (resp == NULL) {
338				error = ENOMEM;
339				break;
340			}
341			run = (struct ng_pipe_run *) resp->data;
342			bcopy(&priv->upper.run, &run->downstream,
343				sizeof(run->downstream));
344			bcopy(&priv->lower.run, &run->upstream,
345				sizeof(run->upstream));
346			break;
347		case NGM_PIPE_GET_CFG:
348			NG_MKRESPONSE(resp, msg, sizeof(*cfg), M_NOWAIT);
349			if (resp == NULL) {
350				error = ENOMEM;
351				break;
352			}
353			cfg = (struct ng_pipe_cfg *) resp->data;
354			bcopy(&priv->upper.cfg, &cfg->downstream,
355				sizeof(cfg->downstream));
356			bcopy(&priv->lower.cfg, &cfg->upstream,
357				sizeof(cfg->upstream));
358			cfg->delay = priv->delay;
359			cfg->overhead = priv->overhead;
360			cfg->header_offset = priv->header_offset;
361			if (cfg->upstream.bandwidth ==
362			    cfg->downstream.bandwidth) {
363				cfg->bandwidth = cfg->upstream.bandwidth;
364				cfg->upstream.bandwidth = 0;
365				cfg->downstream.bandwidth = 0;
366			} else
367				cfg->bandwidth = 0;
368			break;
369		case NGM_PIPE_SET_CFG:
370			cfg = (struct ng_pipe_cfg *) msg->data;
371			if (msg->header.arglen != sizeof(*cfg)) {
372				error = EINVAL;
373				break;
374			}
375
376			if (cfg->delay == -1)
377				priv->delay = 0;
378			else if (cfg->delay > 0 && cfg->delay < 10000000)
379				priv->delay = cfg->delay;
380
381			if (cfg->bandwidth == -1) {
382				priv->upper.cfg.bandwidth = 0;
383				priv->lower.cfg.bandwidth = 0;
384				priv->overhead = 0;
385			} else if (cfg->bandwidth >= 100 &&
386			    cfg->bandwidth <= 1000000000) {
387				priv->upper.cfg.bandwidth = cfg->bandwidth;
388				priv->lower.cfg.bandwidth = cfg->bandwidth;
389				if (cfg->bandwidth >= 10000000)
390					priv->overhead = 8+4+12; /* Ethernet */
391				else
392					priv->overhead = 10; /* HDLC */
393			}
394
395			if (cfg->overhead == -1)
396				priv->overhead = 0;
397			else if (cfg->overhead > 0 &&
398			    cfg->overhead < MAX_OHSIZE)
399				priv->overhead = cfg->overhead;
400
401			if (cfg->header_offset == -1)
402				priv->header_offset = 0;
403			else if (cfg->header_offset > 0 &&
404			    cfg->header_offset < 64)
405				priv->header_offset = cfg->header_offset;
406
407			prev_down = priv->upper.cfg.ber == 1 ||
408			    priv->lower.cfg.ber == 1;
409			parse_cfg(&priv->upper.cfg, &cfg->downstream,
410			    &priv->upper, priv);
411			parse_cfg(&priv->lower.cfg, &cfg->upstream,
412			    &priv->lower, priv);
413			now_down = priv->upper.cfg.ber == 1 ||
414			    priv->lower.cfg.ber == 1;
415
416			if (prev_down != now_down) {
417				if (now_down)
418					cmd = NGM_LINK_IS_DOWN;
419				else
420					cmd = NGM_LINK_IS_UP;
421
422				if (priv->lower.hook != NULL) {
423					NG_MKMESSAGE(flow_msg, NGM_FLOW_COOKIE,
424					    cmd, 0, M_NOWAIT);
425					if (flow_msg != NULL)
426						NG_SEND_MSG_HOOK(error, node,
427						    flow_msg, priv->lower.hook,
428						    0);
429				}
430				if (priv->upper.hook != NULL) {
431					NG_MKMESSAGE(flow_msg, NGM_FLOW_COOKIE,
432					    cmd, 0, M_NOWAIT);
433					if (flow_msg != NULL)
434						NG_SEND_MSG_HOOK(error, node,
435						    flow_msg, priv->upper.hook,
436						    0);
437				}
438			}
439			break;
440		default:
441			error = EINVAL;
442			break;
443		}
444		break;
445	default:
446		error = EINVAL;
447		break;
448	}
449	NG_RESPOND_MSG(error, node, item, resp);
450	NG_FREE_MSG(msg);
451
452	return (error);
453}
454
455static void
456parse_cfg(struct ng_pipe_hookcfg *current, struct ng_pipe_hookcfg *new,
457	struct hookinfo *hinfo, priv_p priv)
458{
459
460	if (new->ber == -1) {
461		current->ber = 0;
462		if (hinfo->ber_p) {
463			free(hinfo->ber_p, M_NG_PIPE);
464			hinfo->ber_p = NULL;
465		}
466	} else if (new->ber >= 1 && new->ber <= 1000000000000) {
467		static const uint64_t one = 0x1000000000000; /* = 2^48 */
468		uint64_t p0, p;
469		uint32_t fsize, i;
470
471		if (hinfo->ber_p == NULL)
472			hinfo->ber_p =
473			    malloc((MAX_FSIZE + MAX_OHSIZE) * sizeof(uint64_t),
474			    M_NG_PIPE, M_WAITOK);
475		current->ber = new->ber;
476
477		/*
478		 * For given BER and each frame size N (in bytes) calculate
479		 * the probability P_OK that the frame is clean:
480		 *
481		 * P_OK(BER,N) = (1 - 1/BER)^(N*8)
482		 *
483		 * We use a 64-bit fixed-point format with decimal point
484		 * positioned between bits 47 and 48.
485		 */
486		p0 = one - one / new->ber;
487		p = one;
488		for (fsize = 0; fsize < MAX_FSIZE + MAX_OHSIZE; fsize++) {
489			hinfo->ber_p[fsize] = p;
490			for (i = 0; i < 8; i++)
491				p = (p * (p0 & 0xffff) >> 48) +
492				    (p * ((p0 >> 16) & 0xffff) >> 32) +
493				    (p * (p0 >> 32) >> 16);
494		}
495	}
496
497	if (new->qin_size_limit == -1)
498		current->qin_size_limit = 0;
499	else if (new->qin_size_limit >= 5)
500		current->qin_size_limit = new->qin_size_limit;
501
502	if (new->qout_size_limit == -1)
503		current->qout_size_limit = 0;
504	else if (new->qout_size_limit >= 5)
505		current->qout_size_limit = new->qout_size_limit;
506
507	if (new->duplicate == -1)
508		current->duplicate = 0;
509	else if (new->duplicate > 0 && new->duplicate <= 50)
510		current->duplicate = new->duplicate;
511
512	if (new->fifo) {
513		current->fifo = 1;
514		current->wfq = 0;
515		current->drr = 0;
516	}
517
518	if (new->wfq) {
519		current->fifo = 0;
520		current->wfq = 1;
521		current->drr = 0;
522	}
523
524	if (new->drr) {
525		current->fifo = 0;
526		current->wfq = 0;
527		/* DRR quantum */
528		if (new->drr >= 32)
529			current->drr = new->drr;
530		else
531			current->drr = 2048;		/* default quantum */
532	}
533
534	if (new->droptail) {
535		current->droptail = 1;
536		current->drophead = 0;
537	}
538
539	if (new->drophead) {
540		current->droptail = 0;
541		current->drophead = 1;
542	}
543
544	if (new->bandwidth == -1) {
545		current->bandwidth = 0;
546		current->fifo = 1;
547		current->wfq = 0;
548		current->drr = 0;
549	} else if (new->bandwidth >= 100 && new->bandwidth <= 1000000000)
550		current->bandwidth = new->bandwidth;
551
552	if (current->bandwidth | priv->delay |
553	    current->duplicate | current->ber)
554		hinfo->noqueue = 0;
555	else
556		hinfo->noqueue = 1;
557}
558
559/*
560 * Compute a hash signature for a packet. This function suffers from the
561 * NIH sindrome, so probably it would be wise to look around what other
562 * folks have found out to be a good and efficient IP hash function...
563 */
564static int
565ip_hash(struct mbuf *m, int offset)
566{
567	u_int64_t i;
568	struct ip *ip = (struct ip *)(mtod(m, u_char *) + offset);
569
570	if (m->m_len < sizeof(struct ip) + offset ||
571	    ip->ip_v != 4 || ip->ip_hl << 2 != sizeof(struct ip))
572		return 0;
573
574	i = ((u_int64_t) ip->ip_src.s_addr ^
575	    ((u_int64_t) ip->ip_src.s_addr << 13) ^
576	    ((u_int64_t) ip->ip_dst.s_addr << 7) ^
577	    ((u_int64_t) ip->ip_dst.s_addr << 19));
578	return (i ^ (i >> 32));
579}
580
581/*
582 * Receive data on a hook - both in upstream and downstream direction.
583 * We put the frame on the inbound queue, and try to initiate dequeuing
584 * sequence immediately. If inbound queue is full, discard one frame
585 * depending on dropping policy (from the head or from the tail of the
586 * queue).
587 */
588static int
589ngp_rcvdata(hook_p hook, item_p item)
590{
591	struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
592	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
593	struct timeval uuptime;
594	struct timeval *now = &uuptime;
595	struct ngp_fifo *ngp_f = NULL, *ngp_f1;
596	struct ngp_hdr *ngp_h = NULL;
597	struct mbuf *m;
598	int hash, plen;
599	int error = 0;
600
601	/*
602	 * Shortcut from inbound to outbound hook when neither of
603	 * bandwidth, delay, BER or duplication probability is
604	 * configured, nor we have queued frames to drain.
605	 */
606	if (hinfo->run.qin_frames == 0 && hinfo->run.qout_frames == 0 &&
607	    hinfo->noqueue) {
608		struct hookinfo *dest;
609		if (hinfo == &priv->lower)
610			dest = &priv->upper;
611		else
612			dest = &priv->lower;
613
614		/* Send the frame. */
615		plen = NGI_M(item)->m_pkthdr.len;
616		NG_FWD_ITEM_HOOK(error, item, dest->hook);
617
618		/* Update stats. */
619		if (error) {
620			hinfo->stats.out_disc_frames++;
621			hinfo->stats.out_disc_octets += plen;
622		} else {
623			hinfo->stats.fwd_frames++;
624			hinfo->stats.fwd_octets += plen;
625		}
626
627		return (error);
628	}
629
630	microuptime(now);
631
632	/*
633	 * If this was an empty queue, update service deadline time.
634	 */
635	if (hinfo->run.qin_frames == 0) {
636		struct timeval *when = &hinfo->qin_utime;
637		if (when->tv_sec < now->tv_sec || (when->tv_sec == now->tv_sec
638		    && when->tv_usec < now->tv_usec)) {
639			when->tv_sec = now->tv_sec;
640			when->tv_usec = now->tv_usec;
641		}
642	}
643
644	/* Populate the packet header */
645	ngp_h = uma_zalloc(ngp_zone, M_NOWAIT);
646	KASSERT((ngp_h != NULL), ("ngp_h zalloc failed (1)"));
647	NGI_GET_M(item, m);
648	KASSERT(m != NULL, ("NGI_GET_M failed"));
649	ngp_h->m = m;
650	NG_FREE_ITEM(item);
651
652	if (hinfo->cfg.fifo)
653		hash = 0;	/* all packets go into a single FIFO queue */
654	else
655		hash = ip_hash(m, priv->header_offset);
656
657	/* Find the appropriate FIFO queue for the packet and enqueue it*/
658	TAILQ_FOREACH(ngp_f, &hinfo->fifo_head, fifo_le)
659		if (hash == ngp_f->hash)
660			break;
661	if (ngp_f == NULL) {
662		ngp_f = uma_zalloc(ngp_zone, M_NOWAIT);
663		KASSERT(ngp_h != NULL, ("ngp_h zalloc failed (2)"));
664		TAILQ_INIT(&ngp_f->packet_head);
665		ngp_f->hash = hash;
666		ngp_f->packets = 1;
667		ngp_f->rr_deficit = hinfo->cfg.drr;	/* DRR quantum */
668		hinfo->run.fifo_queues++;
669		TAILQ_INSERT_TAIL(&ngp_f->packet_head, ngp_h, ngp_link);
670		FIFO_VTIME_SORT(m->m_pkthdr.len);
671	} else {
672		TAILQ_INSERT_TAIL(&ngp_f->packet_head, ngp_h, ngp_link);
673		ngp_f->packets++;
674	}
675	hinfo->run.qin_frames++;
676	hinfo->run.qin_octets += m->m_pkthdr.len;
677
678	/* Discard a frame if inbound queue limit has been reached */
679	if (hinfo->run.qin_frames > hinfo->cfg.qin_size_limit) {
680		struct mbuf *m1;
681		int longest = 0;
682
683		/* Find the longest queue */
684		TAILQ_FOREACH(ngp_f1, &hinfo->fifo_head, fifo_le)
685			if (ngp_f1->packets > longest) {
686				longest = ngp_f1->packets;
687				ngp_f = ngp_f1;
688			}
689
690		/* Drop a frame from the queue head/tail, depending on cfg */
691		if (hinfo->cfg.drophead)
692			ngp_h = TAILQ_FIRST(&ngp_f->packet_head);
693		else
694			ngp_h = TAILQ_LAST(&ngp_f->packet_head, p_head);
695		TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
696		m1 = ngp_h->m;
697		uma_zfree(ngp_zone, ngp_h);
698		hinfo->run.qin_octets -= m1->m_pkthdr.len;
699		hinfo->stats.in_disc_octets += m1->m_pkthdr.len;
700		m_freem(m1);
701		if (--(ngp_f->packets) == 0) {
702			TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
703			uma_zfree(ngp_zone, ngp_f);
704			hinfo->run.fifo_queues--;
705		}
706		hinfo->run.qin_frames--;
707		hinfo->stats.in_disc_frames++;
708	}
709
710	/*
711	 * Try to start the dequeuing process immediately.
712	 */
713	pipe_dequeue(hinfo, now);
714
715	return (0);
716}
717
718/*
719 * Dequeueing sequence - we basically do the following:
720 *  1) Try to extract the frame from the inbound (bandwidth) queue;
721 *  2) In accordance to BER specified, discard the frame randomly;
722 *  3) If the frame survives BER, prepend it with delay info and move it
723 *     to outbound (delay) queue;
724 *  4) Loop to 2) until bandwidth quota for this timeslice is reached, or
725 *     inbound queue is flushed completely;
726 *  5) Dequeue frames from the outbound queue and send them downstream until
727 *     outbound queue is flushed completely, or the next frame in the queue
728 *     is not due to be dequeued yet
729 */
730static void
731pipe_dequeue(struct hookinfo *hinfo, struct timeval *now) {
732	static uint64_t rand, oldrand;
733	const node_p node = NG_HOOK_NODE(hinfo->hook);
734	const priv_p priv = NG_NODE_PRIVATE(node);
735	struct hookinfo *dest;
736	struct ngp_fifo *ngp_f, *ngp_f1;
737	struct ngp_hdr *ngp_h;
738	struct timeval *when;
739	struct mbuf *m;
740	int plen, error = 0;
741
742	/* Which one is the destination hook? */
743	if (hinfo == &priv->lower)
744		dest = &priv->upper;
745	else
746		dest = &priv->lower;
747
748	/* Bandwidth queue processing */
749	while ((ngp_f = TAILQ_FIRST(&hinfo->fifo_head))) {
750		when = &hinfo->qin_utime;
751		if (when->tv_sec > now->tv_sec || (when->tv_sec == now->tv_sec
752		    && when->tv_usec > now->tv_usec))
753			break;
754
755		ngp_h = TAILQ_FIRST(&ngp_f->packet_head);
756		m = ngp_h->m;
757
758		/* Deficit Round Robin (DRR) processing */
759		if (hinfo->cfg.drr) {
760			if (ngp_f->rr_deficit >= m->m_pkthdr.len) {
761				ngp_f->rr_deficit -= m->m_pkthdr.len;
762			} else {
763				ngp_f->rr_deficit += hinfo->cfg.drr;
764				TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
765				TAILQ_INSERT_TAIL(&hinfo->fifo_head,
766				    ngp_f, fifo_le);
767				continue;
768			}
769		}
770
771		/*
772		 * Either create a duplicate and pass it on, or dequeue
773		 * the original packet...
774		 */
775		if (hinfo->cfg.duplicate &&
776		    random() % 100 <= hinfo->cfg.duplicate) {
777			ngp_h = uma_zalloc(ngp_zone, M_NOWAIT);
778			KASSERT(ngp_h != NULL, ("ngp_h zalloc failed (3)"));
779			m = m_dup(m, M_NOWAIT);
780			KASSERT(m != NULL, ("m_dup failed"));
781			ngp_h->m = m;
782		} else {
783			TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
784			hinfo->run.qin_frames--;
785			hinfo->run.qin_octets -= m->m_pkthdr.len;
786			ngp_f->packets--;
787		}
788
789		/* Calculate the serialization delay */
790		if (hinfo->cfg.bandwidth) {
791			hinfo->qin_utime.tv_usec +=
792			    ((uint64_t) m->m_pkthdr.len + priv->overhead ) *
793			    8000000 / hinfo->cfg.bandwidth;
794			hinfo->qin_utime.tv_sec +=
795			    hinfo->qin_utime.tv_usec / 1000000;
796			hinfo->qin_utime.tv_usec =
797			    hinfo->qin_utime.tv_usec % 1000000;
798		}
799		when = &ngp_h->when;
800		when->tv_sec = hinfo->qin_utime.tv_sec;
801		when->tv_usec = hinfo->qin_utime.tv_usec;
802
803		/* Sort / rearrange inbound queues */
804		if (ngp_f->packets) {
805			if (hinfo->cfg.wfq) {
806				TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
807				FIFO_VTIME_SORT(TAILQ_FIRST(
808				    &ngp_f->packet_head)->m->m_pkthdr.len)
809			}
810		} else {
811			TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
812			uma_zfree(ngp_zone, ngp_f);
813			hinfo->run.fifo_queues--;
814		}
815
816		/* Randomly discard the frame, according to BER setting */
817		if (hinfo->cfg.ber) {
818			oldrand = rand;
819			rand = random();
820			if (((oldrand ^ rand) << 17) >=
821			    hinfo->ber_p[priv->overhead + m->m_pkthdr.len]) {
822				hinfo->stats.out_disc_frames++;
823				hinfo->stats.out_disc_octets += m->m_pkthdr.len;
824				uma_zfree(ngp_zone, ngp_h);
825				m_freem(m);
826				continue;
827			}
828		}
829
830		/* Discard frame if outbound queue size limit exceeded */
831		if (hinfo->cfg.qout_size_limit &&
832		    hinfo->run.qout_frames>=hinfo->cfg.qout_size_limit) {
833			hinfo->stats.out_disc_frames++;
834			hinfo->stats.out_disc_octets += m->m_pkthdr.len;
835			uma_zfree(ngp_zone, ngp_h);
836			m_freem(m);
837			continue;
838		}
839
840		/* Calculate the propagation delay */
841		when->tv_usec += priv->delay;
842		when->tv_sec += when->tv_usec / 1000000;
843		when->tv_usec = when->tv_usec % 1000000;
844
845		/* Put the frame into the delay queue */
846		TAILQ_INSERT_TAIL(&hinfo->qout_head, ngp_h, ngp_link);
847		hinfo->run.qout_frames++;
848		hinfo->run.qout_octets += m->m_pkthdr.len;
849	}
850
851	/* Delay queue processing */
852	while ((ngp_h = TAILQ_FIRST(&hinfo->qout_head))) {
853		when = &ngp_h->when;
854		m = ngp_h->m;
855		if (when->tv_sec > now->tv_sec ||
856		    (when->tv_sec == now->tv_sec &&
857		    when->tv_usec > now->tv_usec))
858			break;
859
860		/* Update outbound queue stats */
861		plen = m->m_pkthdr.len;
862		hinfo->run.qout_frames--;
863		hinfo->run.qout_octets -= plen;
864
865		/* Dequeue the packet from qout */
866		TAILQ_REMOVE(&hinfo->qout_head, ngp_h, ngp_link);
867		uma_zfree(ngp_zone, ngp_h);
868
869		NG_SEND_DATA(error, dest->hook, m, meta);
870		if (error) {
871			hinfo->stats.out_disc_frames++;
872			hinfo->stats.out_disc_octets += plen;
873		} else {
874			hinfo->stats.fwd_frames++;
875			hinfo->stats.fwd_octets += plen;
876		}
877	}
878
879	if ((hinfo->run.qin_frames != 0 || hinfo->run.qout_frames != 0) &&
880	    !priv->timer_scheduled) {
881		ng_callout(&priv->timer, node, NULL, 1, ngp_callout, NULL, 0);
882		priv->timer_scheduled = 1;
883	}
884}
885
886/*
887 * This routine is called on every clock tick.  We poll connected hooks
888 * for queued frames by calling pipe_dequeue().
889 */
890static void
891ngp_callout(node_p node, hook_p hook, void *arg1, int arg2)
892{
893	const priv_p priv = NG_NODE_PRIVATE(node);
894	struct timeval now;
895
896	priv->timer_scheduled = 0;
897	microuptime(&now);
898	if (priv->upper.hook != NULL)
899		pipe_dequeue(&priv->upper, &now);
900	if (priv->lower.hook != NULL)
901		pipe_dequeue(&priv->lower, &now);
902}
903
904/*
905 * Shutdown processing
906 *
907 * This is tricky. If we have both a lower and upper hook, then we
908 * probably want to extricate ourselves and leave the two peers
909 * still linked to each other. Otherwise we should just shut down as
910 * a normal node would.
911 */
912static int
913ngp_shutdown(node_p node)
914{
915	const priv_p priv = NG_NODE_PRIVATE(node);
916
917	if (priv->timer_scheduled)
918		ng_uncallout(&priv->timer, node);
919	if (priv->lower.hook && priv->upper.hook)
920		ng_bypass(priv->lower.hook, priv->upper.hook);
921	else {
922		if (priv->upper.hook != NULL)
923			ng_rmhook_self(priv->upper.hook);
924		if (priv->lower.hook != NULL)
925			ng_rmhook_self(priv->lower.hook);
926	}
927	NG_NODE_UNREF(node);
928	free(priv, M_NG_PIPE);
929	return (0);
930}
931
932/*
933 * Hook disconnection
934 */
935static int
936ngp_disconnect(hook_p hook)
937{
938	struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
939	struct ngp_fifo *ngp_f;
940	struct ngp_hdr *ngp_h;
941
942	KASSERT(hinfo != NULL, ("%s: null info", __FUNCTION__));
943	hinfo->hook = NULL;
944
945	/* Flush all fifo queues associated with the hook */
946	while ((ngp_f = TAILQ_FIRST(&hinfo->fifo_head))) {
947		while ((ngp_h = TAILQ_FIRST(&ngp_f->packet_head))) {
948			TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
949			m_freem(ngp_h->m);
950			uma_zfree(ngp_zone, ngp_h);
951		}
952		TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
953		uma_zfree(ngp_zone, ngp_f);
954	}
955
956	/* Flush the delay queue */
957	while ((ngp_h = TAILQ_FIRST(&hinfo->qout_head))) {
958		TAILQ_REMOVE(&hinfo->qout_head, ngp_h, ngp_link);
959		m_freem(ngp_h->m);
960		uma_zfree(ngp_zone, ngp_h);
961	}
962
963	/* Release the packet loss probability table (BER) */
964	if (hinfo->ber_p)
965		free(hinfo->ber_p, M_NG_PIPE);
966
967	return (0);
968}
969
970static int
971ngp_modevent(module_t mod, int type, void *unused)
972{
973	int error = 0;
974
975	switch (type) {
976	case MOD_LOAD:
977		ngp_zone = uma_zcreate("ng_pipe", max(sizeof(struct ngp_hdr),
978		    sizeof (struct ngp_fifo)), NULL, NULL, NULL, NULL,
979		    UMA_ALIGN_PTR, 0);
980		if (ngp_zone == NULL)
981			panic("ng_pipe: couldn't allocate descriptor zone");
982		break;
983	case MOD_UNLOAD:
984		uma_zdestroy(ngp_zone);
985		break;
986	default:
987		error = EOPNOTSUPP;
988		break;
989	}
990
991	return (error);
992}
993