1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
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
33/*
34 * This node permits simple traffic shaping by emulating bandwidth
35 * and delay, as well as random packet losses.
36 * The node has two hooks, upper and lower. Traffic flowing from upper to
37 * lower hook is referenced as downstream, and vice versa. Parameters for
38 * both directions can be set separately, except for delay.
39 */
40
41#include <sys/param.h>
42#include <sys/errno.h>
43#include <sys/systm.h>
44#include <sys/kernel.h>
45#include <sys/malloc.h>
46#include <sys/mbuf.h>
47#include <sys/prng.h>
48#include <sys/time.h>
49
50#include <vm/uma.h>
51
52#include <net/vnet.h>
53
54#include <netinet/in.h>
55#include <netinet/in_systm.h>
56#include <netinet/ip.h>
57
58#include <netgraph/ng_message.h>
59#include <netgraph/netgraph.h>
60#include <netgraph/ng_parse.h>
61#include <netgraph/ng_pipe.h>
62
63static MALLOC_DEFINE(M_NG_PIPE, "ng_pipe", "ng_pipe");
64
65/* Packet header struct */
66struct ngp_hdr {
67	TAILQ_ENTRY(ngp_hdr)	ngp_link;	/* next pkt in queue */
68	struct timeval		when;		/* this packet's due time */
69	struct mbuf		*m;		/* ptr to the packet data */
70};
71TAILQ_HEAD(p_head, ngp_hdr);
72
73/* FIFO queue struct */
74struct ngp_fifo {
75	TAILQ_ENTRY(ngp_fifo)	fifo_le;	/* list of active queues only */
76	struct p_head		packet_head;	/* FIFO queue head */
77	u_int32_t		hash;		/* flow signature */
78	struct timeval		vtime;		/* virtual time, for WFQ */
79	u_int32_t		rr_deficit;	/* for DRR */
80	u_int32_t		packets;	/* # of packets in this queue */
81};
82
83/* Per hook info */
84struct hookinfo {
85	hook_p			hook;
86	int			noqueue;	/* bypass any processing */
87	TAILQ_HEAD(, ngp_fifo)	fifo_head;	/* FIFO queues */
88	TAILQ_HEAD(, ngp_hdr)	qout_head;	/* delay queue head */
89	struct timeval		qin_utime;
90	struct ng_pipe_hookcfg	cfg;
91	struct ng_pipe_hookrun	run;
92	struct ng_pipe_hookstat	stats;
93	uint64_t		*ber_p;		/* loss_p(BER,psize) map */
94};
95
96/* Per node info */
97struct node_priv {
98	u_int64_t		delay;
99	u_int32_t		overhead;
100	u_int32_t		header_offset;
101	struct hookinfo		lower;
102	struct hookinfo		upper;
103	struct callout		timer;
104	int			timer_scheduled;
105};
106typedef struct node_priv *priv_p;
107
108/* Macro for calculating the virtual time for packet dequeueing in WFQ */
109#define FIFO_VTIME_SORT(plen)						\
110	if (hinfo->cfg.wfq && hinfo->cfg.bandwidth) {			\
111		ngp_f->vtime.tv_usec = now->tv_usec + ((uint64_t) (plen) \
112			+ priv->overhead ) * hinfo->run.fifo_queues *	\
113			8000000 / hinfo->cfg.bandwidth;			\
114		ngp_f->vtime.tv_sec = now->tv_sec +			\
115			ngp_f->vtime.tv_usec / 1000000;			\
116		ngp_f->vtime.tv_usec = ngp_f->vtime.tv_usec % 1000000;	\
117		TAILQ_FOREACH(ngp_f1, &hinfo->fifo_head, fifo_le)	\
118			if (ngp_f1->vtime.tv_sec > ngp_f->vtime.tv_sec || \
119			    (ngp_f1->vtime.tv_sec == ngp_f->vtime.tv_sec && \
120			    ngp_f1->vtime.tv_usec > ngp_f->vtime.tv_usec)) \
121				break;					\
122		if (ngp_f1 == NULL)					\
123			TAILQ_INSERT_TAIL(&hinfo->fifo_head, ngp_f, fifo_le); \
124		else							\
125			TAILQ_INSERT_BEFORE(ngp_f1, ngp_f, fifo_le);	\
126	} else								\
127		TAILQ_INSERT_TAIL(&hinfo->fifo_head, ngp_f, fifo_le);	\
128
129static void	parse_cfg(struct ng_pipe_hookcfg *, struct ng_pipe_hookcfg *,
130			struct hookinfo *, priv_p);
131static void	pipe_dequeue(struct hookinfo *, struct timeval *);
132static void	ngp_callout(node_p, hook_p, void *, int);
133static int	ngp_modevent(module_t, int, void *);
134
135/* zone for storing ngp_hdr-s */
136static uma_zone_t ngp_zone;
137
138/* Netgraph methods */
139static ng_constructor_t	ngp_constructor;
140static ng_rcvmsg_t	ngp_rcvmsg;
141static ng_shutdown_t	ngp_shutdown;
142static ng_newhook_t	ngp_newhook;
143static ng_rcvdata_t	ngp_rcvdata;
144static ng_disconnect_t	ngp_disconnect;
145
146/* Parse type for struct ng_pipe_hookstat */
147static const struct ng_parse_struct_field
148	ng_pipe_hookstat_type_fields[] = NG_PIPE_HOOKSTAT_INFO;
149static const struct ng_parse_type ng_pipe_hookstat_type = {
150	&ng_parse_struct_type,
151	&ng_pipe_hookstat_type_fields
152};
153
154/* Parse type for struct ng_pipe_stats */
155static const struct ng_parse_struct_field ng_pipe_stats_type_fields[] =
156	NG_PIPE_STATS_INFO(&ng_pipe_hookstat_type);
157static const struct ng_parse_type ng_pipe_stats_type = {
158	&ng_parse_struct_type,
159	&ng_pipe_stats_type_fields
160};
161
162/* Parse type for struct ng_pipe_hookrun */
163static const struct ng_parse_struct_field
164	ng_pipe_hookrun_type_fields[] = NG_PIPE_HOOKRUN_INFO;
165static const struct ng_parse_type ng_pipe_hookrun_type = {
166	&ng_parse_struct_type,
167	&ng_pipe_hookrun_type_fields
168};
169
170/* Parse type for struct ng_pipe_run */
171static const struct ng_parse_struct_field
172	ng_pipe_run_type_fields[] = NG_PIPE_RUN_INFO(&ng_pipe_hookrun_type);
173static const struct ng_parse_type ng_pipe_run_type = {
174	&ng_parse_struct_type,
175	&ng_pipe_run_type_fields
176};
177
178/* Parse type for struct ng_pipe_hookcfg */
179static const struct ng_parse_struct_field
180	ng_pipe_hookcfg_type_fields[] = NG_PIPE_HOOKCFG_INFO;
181static const struct ng_parse_type ng_pipe_hookcfg_type = {
182	&ng_parse_struct_type,
183	&ng_pipe_hookcfg_type_fields
184};
185
186/* Parse type for struct ng_pipe_cfg */
187static const struct ng_parse_struct_field
188	ng_pipe_cfg_type_fields[] = NG_PIPE_CFG_INFO(&ng_pipe_hookcfg_type);
189static const struct ng_parse_type ng_pipe_cfg_type = {
190	&ng_parse_struct_type,
191	&ng_pipe_cfg_type_fields
192};
193
194/* List of commands and how to convert arguments to/from ASCII */
195static const struct ng_cmdlist ngp_cmds[] = {
196	{
197		.cookie =	NGM_PIPE_COOKIE,
198		.cmd =		NGM_PIPE_GET_STATS,
199		.name =		"getstats",
200		.respType =	&ng_pipe_stats_type
201	},
202	{
203		.cookie =	NGM_PIPE_COOKIE,
204		.cmd =		NGM_PIPE_CLR_STATS,
205		.name =		"clrstats"
206	},
207	{
208		.cookie =	NGM_PIPE_COOKIE,
209		.cmd =		NGM_PIPE_GETCLR_STATS,
210		.name =		"getclrstats",
211		.respType =	&ng_pipe_stats_type
212	},
213	{
214		.cookie =	NGM_PIPE_COOKIE,
215		.cmd =		NGM_PIPE_GET_RUN,
216		.name =		"getrun",
217		.respType =	&ng_pipe_run_type
218	},
219	{
220		.cookie =	NGM_PIPE_COOKIE,
221		.cmd =		NGM_PIPE_GET_CFG,
222		.name =		"getcfg",
223		.respType =	&ng_pipe_cfg_type
224	},
225	{
226		.cookie =	NGM_PIPE_COOKIE,
227		.cmd =		NGM_PIPE_SET_CFG,
228		.name =		"setcfg",
229		.mesgType =	&ng_pipe_cfg_type,
230	},
231	{ 0 }
232};
233
234/* Netgraph type descriptor */
235static struct ng_type ng_pipe_typestruct = {
236	.version =	NG_ABI_VERSION,
237	.name =		NG_PIPE_NODE_TYPE,
238	.mod_event =	ngp_modevent,
239	.constructor =	ngp_constructor,
240	.shutdown =	ngp_shutdown,
241	.rcvmsg =	ngp_rcvmsg,
242	.newhook =	ngp_newhook,
243	.rcvdata =	ngp_rcvdata,
244	.disconnect =	ngp_disconnect,
245	.cmdlist =	ngp_cmds
246};
247NETGRAPH_INIT(pipe, &ng_pipe_typestruct);
248
249/* Node constructor */
250static int
251ngp_constructor(node_p node)
252{
253	priv_p priv;
254
255	priv = malloc(sizeof(*priv), M_NG_PIPE, M_ZERO | M_WAITOK);
256	NG_NODE_SET_PRIVATE(node, priv);
257
258	/* Mark node as single-threaded */
259	NG_NODE_FORCE_WRITER(node);
260
261	ng_callout_init(&priv->timer);
262
263	return (0);
264}
265
266/* Add a hook */
267static int
268ngp_newhook(node_p node, hook_p hook, const char *name)
269{
270	const priv_p priv = NG_NODE_PRIVATE(node);
271	struct hookinfo *hinfo;
272
273	if (strcmp(name, NG_PIPE_HOOK_UPPER) == 0) {
274		bzero(&priv->upper, sizeof(priv->upper));
275		priv->upper.hook = hook;
276		NG_HOOK_SET_PRIVATE(hook, &priv->upper);
277	} else if (strcmp(name, NG_PIPE_HOOK_LOWER) == 0) {
278		bzero(&priv->lower, sizeof(priv->lower));
279		priv->lower.hook = hook;
280		NG_HOOK_SET_PRIVATE(hook, &priv->lower);
281	} else
282		return (EINVAL);
283
284	/* Load non-zero initial cfg values */
285	hinfo = NG_HOOK_PRIVATE(hook);
286	hinfo->cfg.qin_size_limit = 50;
287	hinfo->cfg.fifo = 1;
288	hinfo->cfg.droptail = 1;
289	TAILQ_INIT(&hinfo->fifo_head);
290	TAILQ_INIT(&hinfo->qout_head);
291	return (0);
292}
293
294/* Receive a control message */
295static int
296ngp_rcvmsg(node_p node, item_p item, hook_p lasthook)
297{
298	const priv_p priv = NG_NODE_PRIVATE(node);
299	struct ng_mesg *resp = NULL;
300	struct ng_mesg *msg, *flow_msg;
301	struct ng_pipe_stats *stats;
302	struct ng_pipe_run *run;
303	struct ng_pipe_cfg *cfg;
304	int error = 0;
305	int prev_down, now_down, cmd;
306
307	NGI_GET_MSG(item, msg);
308	switch (msg->header.typecookie) {
309	case NGM_PIPE_COOKIE:
310		switch (msg->header.cmd) {
311		case NGM_PIPE_GET_STATS:
312		case NGM_PIPE_CLR_STATS:
313		case NGM_PIPE_GETCLR_STATS:
314			if (msg->header.cmd != NGM_PIPE_CLR_STATS) {
315				NG_MKRESPONSE(resp, msg,
316				    sizeof(*stats), M_NOWAIT);
317				if (resp == NULL) {
318					error = ENOMEM;
319					break;
320				}
321				stats = (struct ng_pipe_stats *) resp->data;
322				bcopy(&priv->upper.stats, &stats->downstream,
323				    sizeof(stats->downstream));
324				bcopy(&priv->lower.stats, &stats->upstream,
325				    sizeof(stats->upstream));
326			}
327			if (msg->header.cmd != NGM_PIPE_GET_STATS) {
328				bzero(&priv->upper.stats,
329				    sizeof(priv->upper.stats));
330				bzero(&priv->lower.stats,
331				    sizeof(priv->lower.stats));
332			}
333			break;
334		case NGM_PIPE_GET_RUN:
335			NG_MKRESPONSE(resp, msg, sizeof(*run), M_NOWAIT);
336			if (resp == NULL) {
337				error = ENOMEM;
338				break;
339			}
340			run = (struct ng_pipe_run *) resp->data;
341			bcopy(&priv->upper.run, &run->downstream,
342				sizeof(run->downstream));
343			bcopy(&priv->lower.run, &run->upstream,
344				sizeof(run->upstream));
345			break;
346		case NGM_PIPE_GET_CFG:
347			NG_MKRESPONSE(resp, msg, sizeof(*cfg), M_NOWAIT);
348			if (resp == NULL) {
349				error = ENOMEM;
350				break;
351			}
352			cfg = (struct ng_pipe_cfg *) resp->data;
353			bcopy(&priv->upper.cfg, &cfg->downstream,
354				sizeof(cfg->downstream));
355			bcopy(&priv->lower.cfg, &cfg->upstream,
356				sizeof(cfg->upstream));
357			cfg->delay = priv->delay;
358			cfg->overhead = priv->overhead;
359			cfg->header_offset = priv->header_offset;
360			if (cfg->upstream.bandwidth ==
361			    cfg->downstream.bandwidth) {
362				cfg->bandwidth = cfg->upstream.bandwidth;
363				cfg->upstream.bandwidth = 0;
364				cfg->downstream.bandwidth = 0;
365			} else
366				cfg->bandwidth = 0;
367			break;
368		case NGM_PIPE_SET_CFG:
369			cfg = (struct ng_pipe_cfg *) msg->data;
370			if (msg->header.arglen != sizeof(*cfg)) {
371				error = EINVAL;
372				break;
373			}
374
375			if (cfg->delay == -1)
376				priv->delay = 0;
377			else if (cfg->delay > 0 && cfg->delay < 10000000)
378				priv->delay = cfg->delay;
379
380			if (cfg->bandwidth == -1) {
381				priv->upper.cfg.bandwidth = 0;
382				priv->lower.cfg.bandwidth = 0;
383				priv->overhead = 0;
384			} else if (cfg->bandwidth >= 100 &&
385			    cfg->bandwidth <= 1000000000) {
386				priv->upper.cfg.bandwidth = cfg->bandwidth;
387				priv->lower.cfg.bandwidth = cfg->bandwidth;
388				if (cfg->bandwidth >= 10000000)
389					priv->overhead = 8+4+12; /* Ethernet */
390				else
391					priv->overhead = 10; /* HDLC */
392			}
393
394			if (cfg->overhead == -1)
395				priv->overhead = 0;
396			else if (cfg->overhead > 0 &&
397			    cfg->overhead < MAX_OHSIZE)
398				priv->overhead = cfg->overhead;
399
400			if (cfg->header_offset == -1)
401				priv->header_offset = 0;
402			else if (cfg->header_offset > 0 &&
403			    cfg->header_offset < 64)
404				priv->header_offset = cfg->header_offset;
405
406			prev_down = priv->upper.cfg.ber == 1 ||
407			    priv->lower.cfg.ber == 1;
408			parse_cfg(&priv->upper.cfg, &cfg->downstream,
409			    &priv->upper, priv);
410			parse_cfg(&priv->lower.cfg, &cfg->upstream,
411			    &priv->lower, priv);
412			now_down = priv->upper.cfg.ber == 1 ||
413			    priv->lower.cfg.ber == 1;
414
415			if (prev_down != now_down) {
416				if (now_down)
417					cmd = NGM_LINK_IS_DOWN;
418				else
419					cmd = NGM_LINK_IS_UP;
420
421				if (priv->lower.hook != NULL) {
422					NG_MKMESSAGE(flow_msg, NGM_FLOW_COOKIE,
423					    cmd, 0, M_NOWAIT);
424					if (flow_msg != NULL)
425						NG_SEND_MSG_HOOK(error, node,
426						    flow_msg, priv->lower.hook,
427						    0);
428				}
429				if (priv->upper.hook != NULL) {
430					NG_MKMESSAGE(flow_msg, NGM_FLOW_COOKIE,
431					    cmd, 0, M_NOWAIT);
432					if (flow_msg != NULL)
433						NG_SEND_MSG_HOOK(error, node,
434						    flow_msg, priv->upper.hook,
435						    0);
436				}
437			}
438			break;
439		default:
440			error = EINVAL;
441			break;
442		}
443		break;
444	default:
445		error = EINVAL;
446		break;
447	}
448	NG_RESPOND_MSG(error, node, item, resp);
449	NG_FREE_MSG(msg);
450
451	return (error);
452}
453
454static void
455parse_cfg(struct ng_pipe_hookcfg *current, struct ng_pipe_hookcfg *new,
456	struct hookinfo *hinfo, priv_p priv)
457{
458
459	if (new->ber == -1) {
460		current->ber = 0;
461		if (hinfo->ber_p) {
462			free(hinfo->ber_p, M_NG_PIPE);
463			hinfo->ber_p = NULL;
464		}
465	} else if (new->ber >= 1 && new->ber <= 1000000000000) {
466		static const uint64_t one = 0x1000000000000; /* = 2^48 */
467		uint64_t p0, p;
468		uint32_t fsize, i;
469
470		if (hinfo->ber_p == NULL)
471			hinfo->ber_p =
472			    malloc((MAX_FSIZE + MAX_OHSIZE) * sizeof(uint64_t),
473			    M_NG_PIPE, M_WAITOK);
474		current->ber = new->ber;
475
476		/*
477		 * For given BER and each frame size N (in bytes) calculate
478		 * the probability P_OK that the frame is clean:
479		 *
480		 * P_OK(BER,N) = (1 - 1/BER)^(N*8)
481		 *
482		 * We use a 64-bit fixed-point format with decimal point
483		 * positioned between bits 47 and 48.
484		 */
485		p0 = one - one / new->ber;
486		p = one;
487		for (fsize = 0; fsize < MAX_FSIZE + MAX_OHSIZE; fsize++) {
488			hinfo->ber_p[fsize] = p;
489			for (i = 0; i < 8; i++)
490				p = (p * (p0 & 0xffff) >> 48) +
491				    (p * ((p0 >> 16) & 0xffff) >> 32) +
492				    (p * (p0 >> 32) >> 16);
493		}
494	}
495
496	if (new->qin_size_limit == -1)
497		current->qin_size_limit = 0;
498	else if (new->qin_size_limit >= 5)
499		current->qin_size_limit = new->qin_size_limit;
500
501	if (new->qout_size_limit == -1)
502		current->qout_size_limit = 0;
503	else if (new->qout_size_limit >= 5)
504		current->qout_size_limit = new->qout_size_limit;
505
506	if (new->duplicate == -1)
507		current->duplicate = 0;
508	else if (new->duplicate > 0 && new->duplicate <= 50)
509		current->duplicate = new->duplicate;
510
511	if (new->fifo) {
512		current->fifo = 1;
513		current->wfq = 0;
514		current->drr = 0;
515	}
516
517	if (new->wfq) {
518		current->fifo = 0;
519		current->wfq = 1;
520		current->drr = 0;
521	}
522
523	if (new->drr) {
524		current->fifo = 0;
525		current->wfq = 0;
526		/* DRR quantum */
527		if (new->drr >= 32)
528			current->drr = new->drr;
529		else
530			current->drr = 2048;		/* default quantum */
531	}
532
533	if (new->droptail) {
534		current->droptail = 1;
535		current->drophead = 0;
536	}
537
538	if (new->drophead) {
539		current->droptail = 0;
540		current->drophead = 1;
541	}
542
543	if (new->bandwidth == -1) {
544		current->bandwidth = 0;
545		current->fifo = 1;
546		current->wfq = 0;
547		current->drr = 0;
548	} else if (new->bandwidth >= 100 && new->bandwidth <= 1000000000)
549		current->bandwidth = new->bandwidth;
550
551	if (current->bandwidth | priv->delay |
552	    current->duplicate | current->ber)
553		hinfo->noqueue = 0;
554	else
555		hinfo->noqueue = 1;
556}
557
558/*
559 * Compute a hash signature for a packet. This function suffers from the
560 * NIH sindrome, so probably it would be wise to look around what other
561 * folks have found out to be a good and efficient IP hash function...
562 */
563static int
564ip_hash(struct mbuf *m, int offset)
565{
566	u_int64_t i;
567	struct ip *ip = (struct ip *)(mtod(m, u_char *) + offset);
568
569	if (m->m_len < sizeof(struct ip) + offset ||
570	    ip->ip_v != 4 || ip->ip_hl << 2 != sizeof(struct ip))
571		return 0;
572
573	i = ((u_int64_t) ip->ip_src.s_addr ^
574	    ((u_int64_t) ip->ip_src.s_addr << 13) ^
575	    ((u_int64_t) ip->ip_dst.s_addr << 7) ^
576	    ((u_int64_t) ip->ip_dst.s_addr << 19));
577	return (i ^ (i >> 32));
578}
579
580/*
581 * Receive data on a hook - both in upstream and downstream direction.
582 * We put the frame on the inbound queue, and try to initiate dequeuing
583 * sequence immediately. If inbound queue is full, discard one frame
584 * depending on dropping policy (from the head or from the tail of the
585 * queue).
586 */
587static int
588ngp_rcvdata(hook_p hook, item_p item)
589{
590	struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
591	const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
592	struct timeval uuptime;
593	struct timeval *now = &uuptime;
594	struct ngp_fifo *ngp_f = NULL, *ngp_f1;
595	struct ngp_hdr *ngp_h = NULL;
596	struct mbuf *m;
597	int hash, plen;
598	int error = 0;
599
600	/*
601	 * Shortcut from inbound to outbound hook when neither of
602	 * bandwidth, delay, BER or duplication probability is
603	 * configured, nor we have queued frames to drain.
604	 */
605	if (hinfo->run.qin_frames == 0 && hinfo->run.qout_frames == 0 &&
606	    hinfo->noqueue) {
607		struct hookinfo *dest;
608		if (hinfo == &priv->lower)
609			dest = &priv->upper;
610		else
611			dest = &priv->lower;
612
613		/* Send the frame. */
614		plen = NGI_M(item)->m_pkthdr.len;
615		NG_FWD_ITEM_HOOK(error, item, dest->hook);
616
617		/* Update stats. */
618		if (error) {
619			hinfo->stats.out_disc_frames++;
620			hinfo->stats.out_disc_octets += plen;
621		} else {
622			hinfo->stats.fwd_frames++;
623			hinfo->stats.fwd_octets += plen;
624		}
625
626		return (error);
627	}
628
629	microuptime(now);
630
631	/*
632	 * If this was an empty queue, update service deadline time.
633	 */
634	if (hinfo->run.qin_frames == 0) {
635		struct timeval *when = &hinfo->qin_utime;
636		if (when->tv_sec < now->tv_sec || (when->tv_sec == now->tv_sec
637		    && when->tv_usec < now->tv_usec)) {
638			when->tv_sec = now->tv_sec;
639			when->tv_usec = now->tv_usec;
640		}
641	}
642
643	/* Populate the packet header */
644	NGI_GET_M(item, m);
645	NG_FREE_ITEM(item);
646	ngp_h = uma_zalloc(ngp_zone, M_NOWAIT);
647	if (ngp_h == NULL) {
648		NG_FREE_M(m);
649		return (ENOMEM);
650	}
651	ngp_h->m = m;
652
653	if (hinfo->cfg.fifo)
654		hash = 0;	/* all packets go into a single FIFO queue */
655	else
656		hash = ip_hash(m, priv->header_offset);
657
658	/* Find the appropriate FIFO queue for the packet and enqueue it*/
659	TAILQ_FOREACH(ngp_f, &hinfo->fifo_head, fifo_le)
660		if (hash == ngp_f->hash)
661			break;
662	if (ngp_f == NULL) {
663		ngp_f = uma_zalloc(ngp_zone, M_NOWAIT);
664		if (ngp_f == NULL) {
665			NG_FREE_M(ngp_h->m);
666			uma_zfree(ngp_zone, ngp_h);
667			return (ENOMEM);
668		}
669		TAILQ_INIT(&ngp_f->packet_head);
670		ngp_f->hash = hash;
671		ngp_f->packets = 1;
672		ngp_f->rr_deficit = hinfo->cfg.drr;	/* DRR quantum */
673		hinfo->run.fifo_queues++;
674		TAILQ_INSERT_TAIL(&ngp_f->packet_head, ngp_h, ngp_link);
675		FIFO_VTIME_SORT(m->m_pkthdr.len);
676	} else {
677		TAILQ_INSERT_TAIL(&ngp_f->packet_head, ngp_h, ngp_link);
678		ngp_f->packets++;
679	}
680	hinfo->run.qin_frames++;
681	hinfo->run.qin_octets += m->m_pkthdr.len;
682
683	/* Discard a frame if inbound queue limit has been reached */
684	if (hinfo->run.qin_frames > hinfo->cfg.qin_size_limit) {
685		struct mbuf *m1;
686		int longest = 0;
687
688		/* Find the longest queue */
689		TAILQ_FOREACH(ngp_f1, &hinfo->fifo_head, fifo_le)
690			if (ngp_f1->packets > longest) {
691				longest = ngp_f1->packets;
692				ngp_f = ngp_f1;
693			}
694
695		/* Drop a frame from the queue head/tail, depending on cfg */
696		if (hinfo->cfg.drophead)
697			ngp_h = TAILQ_FIRST(&ngp_f->packet_head);
698		else
699			ngp_h = TAILQ_LAST(&ngp_f->packet_head, p_head);
700		TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
701		m1 = ngp_h->m;
702		uma_zfree(ngp_zone, ngp_h);
703		hinfo->run.qin_octets -= m1->m_pkthdr.len;
704		hinfo->stats.in_disc_octets += m1->m_pkthdr.len;
705		m_freem(m1);
706		if (--(ngp_f->packets) == 0) {
707			TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
708			uma_zfree(ngp_zone, ngp_f);
709			hinfo->run.fifo_queues--;
710		}
711		hinfo->run.qin_frames--;
712		hinfo->stats.in_disc_frames++;
713	}
714
715	/*
716	 * Try to start the dequeuing process immediately.
717	 */
718	pipe_dequeue(hinfo, now);
719
720	return (0);
721}
722
723/*
724 * Dequeueing sequence - we basically do the following:
725 *  1) Try to extract the frame from the inbound (bandwidth) queue;
726 *  2) In accordance to BER specified, discard the frame randomly;
727 *  3) If the frame survives BER, prepend it with delay info and move it
728 *     to outbound (delay) queue;
729 *  4) Loop to 2) until bandwidth quota for this timeslice is reached, or
730 *     inbound queue is flushed completely;
731 *  5) Dequeue frames from the outbound queue and send them downstream until
732 *     outbound queue is flushed completely, or the next frame in the queue
733 *     is not due to be dequeued yet
734 */
735static void
736pipe_dequeue(struct hookinfo *hinfo, struct timeval *now) {
737	static uint64_t rand, oldrand;
738	const node_p node = NG_HOOK_NODE(hinfo->hook);
739	const priv_p priv = NG_NODE_PRIVATE(node);
740	struct hookinfo *dest;
741	struct ngp_fifo *ngp_f, *ngp_f1;
742	struct ngp_hdr *ngp_h, *ngp_dup;
743	struct timeval *when;
744	struct mbuf *m;
745	int plen, error = 0;
746
747	/* Which one is the destination hook? */
748	if (hinfo == &priv->lower)
749		dest = &priv->upper;
750	else
751		dest = &priv->lower;
752
753	/* Bandwidth queue processing */
754	while ((ngp_f = TAILQ_FIRST(&hinfo->fifo_head))) {
755		when = &hinfo->qin_utime;
756		if (when->tv_sec > now->tv_sec || (when->tv_sec == now->tv_sec
757		    && when->tv_usec > now->tv_usec))
758			break;
759
760		ngp_h = TAILQ_FIRST(&ngp_f->packet_head);
761		m = ngp_h->m;
762
763		/* Deficit Round Robin (DRR) processing */
764		if (hinfo->cfg.drr) {
765			if (ngp_f->rr_deficit >= m->m_pkthdr.len) {
766				ngp_f->rr_deficit -= m->m_pkthdr.len;
767			} else {
768				ngp_f->rr_deficit += hinfo->cfg.drr;
769				TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
770				TAILQ_INSERT_TAIL(&hinfo->fifo_head,
771				    ngp_f, fifo_le);
772				continue;
773			}
774		}
775
776		/*
777		 * Either create a duplicate and pass it on, or
778		 * dequeue the original packet.  When any of the
779		 * memory allocations for the duplicate package fail,
780		 * simply do not duplicate it at all.
781		 */
782		ngp_dup = NULL;
783		if (hinfo->cfg.duplicate &&
784		    prng32_bounded(100) <= hinfo->cfg.duplicate) {
785			ngp_dup = uma_zalloc(ngp_zone, M_NOWAIT);
786			if (ngp_dup != NULL) {
787				ngp_dup->m = m_dup(m, M_NOWAIT);
788				if (ngp_dup->m == NULL) {
789					uma_zfree(ngp_zone, ngp_dup);
790					ngp_dup = NULL;
791				}
792			}
793		}
794
795		if (ngp_dup != NULL) {
796			ngp_h = ngp_dup;
797			m = ngp_h->m;
798		} else {
799			TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
800			hinfo->run.qin_frames--;
801			hinfo->run.qin_octets -= m->m_pkthdr.len;
802			ngp_f->packets--;
803		}
804
805		/* Calculate the serialization delay */
806		if (hinfo->cfg.bandwidth) {
807			hinfo->qin_utime.tv_usec +=
808			    ((uint64_t) m->m_pkthdr.len + priv->overhead ) *
809			    8000000 / hinfo->cfg.bandwidth;
810			hinfo->qin_utime.tv_sec +=
811			    hinfo->qin_utime.tv_usec / 1000000;
812			hinfo->qin_utime.tv_usec =
813			    hinfo->qin_utime.tv_usec % 1000000;
814		}
815		when = &ngp_h->when;
816		when->tv_sec = hinfo->qin_utime.tv_sec;
817		when->tv_usec = hinfo->qin_utime.tv_usec;
818
819		/* Sort / rearrange inbound queues */
820		if (ngp_f->packets) {
821			if (hinfo->cfg.wfq) {
822				TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
823				FIFO_VTIME_SORT(TAILQ_FIRST(
824				    &ngp_f->packet_head)->m->m_pkthdr.len)
825			}
826		} else {
827			TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
828			uma_zfree(ngp_zone, ngp_f);
829			hinfo->run.fifo_queues--;
830		}
831
832		/* Randomly discard the frame, according to BER setting */
833		if (hinfo->cfg.ber) {
834			oldrand = rand;
835			rand = prng32_bounded(1U << 31);
836			if (((oldrand ^ rand) << 17) >=
837			    hinfo->ber_p[priv->overhead + m->m_pkthdr.len]) {
838				hinfo->stats.out_disc_frames++;
839				hinfo->stats.out_disc_octets += m->m_pkthdr.len;
840				uma_zfree(ngp_zone, ngp_h);
841				m_freem(m);
842				continue;
843			}
844		}
845
846		/* Discard frame if outbound queue size limit exceeded */
847		if (hinfo->cfg.qout_size_limit &&
848		    hinfo->run.qout_frames>=hinfo->cfg.qout_size_limit) {
849			hinfo->stats.out_disc_frames++;
850			hinfo->stats.out_disc_octets += m->m_pkthdr.len;
851			uma_zfree(ngp_zone, ngp_h);
852			m_freem(m);
853			continue;
854		}
855
856		/* Calculate the propagation delay */
857		when->tv_usec += priv->delay;
858		when->tv_sec += when->tv_usec / 1000000;
859		when->tv_usec = when->tv_usec % 1000000;
860
861		/* Put the frame into the delay queue */
862		TAILQ_INSERT_TAIL(&hinfo->qout_head, ngp_h, ngp_link);
863		hinfo->run.qout_frames++;
864		hinfo->run.qout_octets += m->m_pkthdr.len;
865	}
866
867	/* Delay queue processing */
868	while ((ngp_h = TAILQ_FIRST(&hinfo->qout_head))) {
869		when = &ngp_h->when;
870		m = ngp_h->m;
871		if (when->tv_sec > now->tv_sec ||
872		    (when->tv_sec == now->tv_sec &&
873		    when->tv_usec > now->tv_usec))
874			break;
875
876		/* Update outbound queue stats */
877		plen = m->m_pkthdr.len;
878		hinfo->run.qout_frames--;
879		hinfo->run.qout_octets -= plen;
880
881		/* Dequeue the packet from qout */
882		TAILQ_REMOVE(&hinfo->qout_head, ngp_h, ngp_link);
883		uma_zfree(ngp_zone, ngp_h);
884
885		NG_SEND_DATA(error, dest->hook, m, meta);
886		if (error) {
887			hinfo->stats.out_disc_frames++;
888			hinfo->stats.out_disc_octets += plen;
889		} else {
890			hinfo->stats.fwd_frames++;
891			hinfo->stats.fwd_octets += plen;
892		}
893	}
894
895	if ((hinfo->run.qin_frames != 0 || hinfo->run.qout_frames != 0) &&
896	    !priv->timer_scheduled) {
897		ng_callout(&priv->timer, node, NULL, 1, ngp_callout, NULL, 0);
898		priv->timer_scheduled = 1;
899	}
900}
901
902/*
903 * This routine is called on every clock tick.  We poll connected hooks
904 * for queued frames by calling pipe_dequeue().
905 */
906static void
907ngp_callout(node_p node, hook_p hook, void *arg1, int arg2)
908{
909	const priv_p priv = NG_NODE_PRIVATE(node);
910	struct timeval now;
911
912	priv->timer_scheduled = 0;
913	microuptime(&now);
914	if (priv->upper.hook != NULL)
915		pipe_dequeue(&priv->upper, &now);
916	if (priv->lower.hook != NULL)
917		pipe_dequeue(&priv->lower, &now);
918}
919
920/*
921 * Shutdown processing
922 *
923 * This is tricky. If we have both a lower and upper hook, then we
924 * probably want to extricate ourselves and leave the two peers
925 * still linked to each other. Otherwise we should just shut down as
926 * a normal node would.
927 */
928static int
929ngp_shutdown(node_p node)
930{
931	const priv_p priv = NG_NODE_PRIVATE(node);
932
933	if (priv->timer_scheduled)
934		ng_uncallout(&priv->timer, node);
935	if (priv->lower.hook && priv->upper.hook)
936		ng_bypass(priv->lower.hook, priv->upper.hook);
937	else {
938		if (priv->upper.hook != NULL)
939			ng_rmhook_self(priv->upper.hook);
940		if (priv->lower.hook != NULL)
941			ng_rmhook_self(priv->lower.hook);
942	}
943	NG_NODE_UNREF(node);
944	free(priv, M_NG_PIPE);
945	return (0);
946}
947
948/*
949 * Hook disconnection
950 */
951static int
952ngp_disconnect(hook_p hook)
953{
954	struct hookinfo *const hinfo = NG_HOOK_PRIVATE(hook);
955	struct ngp_fifo *ngp_f;
956	struct ngp_hdr *ngp_h;
957	priv_p priv;
958
959	KASSERT(hinfo != NULL, ("%s: null info", __FUNCTION__));
960	hinfo->hook = NULL;
961
962	/* Flush all fifo queues associated with the hook */
963	while ((ngp_f = TAILQ_FIRST(&hinfo->fifo_head))) {
964		while ((ngp_h = TAILQ_FIRST(&ngp_f->packet_head))) {
965			TAILQ_REMOVE(&ngp_f->packet_head, ngp_h, ngp_link);
966			m_freem(ngp_h->m);
967			uma_zfree(ngp_zone, ngp_h);
968		}
969		TAILQ_REMOVE(&hinfo->fifo_head, ngp_f, fifo_le);
970		uma_zfree(ngp_zone, ngp_f);
971	}
972
973	/* Flush the delay queue */
974	while ((ngp_h = TAILQ_FIRST(&hinfo->qout_head))) {
975		TAILQ_REMOVE(&hinfo->qout_head, ngp_h, ngp_link);
976		m_freem(ngp_h->m);
977		uma_zfree(ngp_zone, ngp_h);
978	}
979
980	/* Release the packet loss probability table (BER) */
981	if (hinfo->ber_p)
982		free(hinfo->ber_p, M_NG_PIPE);
983
984	/* Destroy the node if all hooks are disconnected */
985	priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
986
987	if (priv->upper.hook == NULL && priv->lower.hook == NULL)
988		ng_rmnode_self(NG_HOOK_NODE(hook));
989
990	return (0);
991}
992
993static int
994ngp_modevent(module_t mod, int type, void *unused)
995{
996	int error = 0;
997
998	switch (type) {
999	case MOD_LOAD:
1000		ngp_zone = uma_zcreate("ng_pipe", max(sizeof(struct ngp_hdr),
1001		    sizeof (struct ngp_fifo)), NULL, NULL, NULL, NULL,
1002		    UMA_ALIGN_PTR, 0);
1003		break;
1004	case MOD_UNLOAD:
1005		uma_zdestroy(ngp_zone);
1006		break;
1007	default:
1008		error = EOPNOTSUPP;
1009		break;
1010	}
1011
1012	return (error);
1013}
1014