xref: /freebsd/sys/netpfil/ipfw/dn_sched_fq_codel.h (revision 8aac90f18aef7c9eea906c3ff9a001ca7b94f375)
1 /*-
2  * Copyright (C) 2016 Centre for Advanced Internet Architectures,
3  *  Swinburne University of Technology, Melbourne, Australia.
4  * Portions of this code were made possible in part by a gift from
5  *  The Comcast Innovation Fund.
6  * Implemented by Rasool Al-Saadi <ralsaadi@swin.edu.au>
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /*
31  * FQ_Codel Structures and helper functions
32  */
33 
34 #ifndef _IP_DN_SCHED_FQ_CODEL_H
35 #define _IP_DN_SCHED_FQ_CODEL_H
36 
37 /* list of queues */
38 STAILQ_HEAD(fq_codel_list, fq_codel_flow);
39 
40 /* fq_codel parameters including codel */
41 struct dn_sch_fq_codel_parms {
42 	struct dn_aqm_codel_parms	ccfg;	/* CoDel Parameters */
43 	/* FQ_CODEL Parameters */
44 	uint32_t flows_cnt;	/* number of flows */
45 	uint32_t limit;	/* hard limit of fq_codel queue size*/
46 	uint32_t quantum;
47 };	/* defaults */
48 
49 /* flow (sub-queue) stats */
50 struct flow_stats {
51 	uint64_t tot_pkts;	/* statistics counters  */
52 	uint64_t tot_bytes;
53 	uint32_t length;		/* Queue length, in packets */
54 	uint32_t len_bytes;	/* Queue length, in bytes */
55 	uint32_t drops;
56 };
57 
58 /* A flow of packets (sub-queue).*/
59 struct fq_codel_flow {
60 	struct mq	mq;	/* list of packets */
61 	struct flow_stats stats;	/* statistics */
62 	int	deficit;
63 	int active;		/* 1: flow is active (in a list) */
64 	struct codel_status cst;
65 	STAILQ_ENTRY(fq_codel_flow) flowchain;
66 };
67 
68 /* extra fq_codel scheduler configurations */
69 struct fq_codel_schk {
70 	struct dn_sch_fq_codel_parms cfg;
71 };
72 
73 /* fq_codel scheduler instance */
74 struct fq_codel_si {
75 	struct dn_sch_inst _si;	/* standard scheduler instance */
76 	struct dn_queue main_q; /* main queue is after si directly */
77 
78 	struct fq_codel_flow *flows; /* array of flows (queues) */
79 	uint32_t perturbation; /* random value */
80 	struct fq_codel_list newflows;	/* list of new queues */
81 	struct fq_codel_list oldflows;		/* list of old queues */
82 };
83 
84 /* Helper function to update queue&main-queue and scheduler statistics.
85  * negative len + drop -> drop
86  * negative len -> dequeue
87  * positive len -> enqueue
88  * positive len + drop -> drop during enqueue
89  */
90 __inline static void
91 fq_update_stats(struct fq_codel_flow *q, struct fq_codel_si *si, int len,
92 	int drop)
93 {
94 	int inc = 0;
95 
96 	if (len < 0)
97 		inc = -1;
98 	else if (len > 0)
99 		inc = 1;
100 
101 	if (drop) {
102 		si->main_q.ni.drops ++;
103 		q->stats.drops ++;
104 		si->_si.ni.drops ++;
105 		V_dn_cfg.io_pkt_drop ++;
106 	}
107 
108 	if (!drop || (drop && len < 0)) {
109 		/* Update stats for the main queue */
110 		si->main_q.ni.length += inc;
111 		si->main_q.ni.len_bytes += len;
112 
113 		/*update sub-queue stats */
114 		q->stats.length += inc;
115 		q->stats.len_bytes += len;
116 
117 		/*update scheduler instance stats */
118 		si->_si.ni.length += inc;
119 		si->_si.ni.len_bytes += len;
120 	}
121 
122 	if (inc > 0) {
123 		si->main_q.ni.tot_bytes += len;
124 		si->main_q.ni.tot_pkts ++;
125 
126 		q->stats.tot_bytes +=len;
127 		q->stats.tot_pkts++;
128 
129 		si->_si.ni.tot_bytes +=len;
130 		si->_si.ni.tot_pkts ++;
131 	}
132 
133 }
134 
135 /* extract the head of fq_codel sub-queue */
136 __inline static struct mbuf *
137 fq_codel_extract_head(struct fq_codel_flow *q, aqm_time_t *pkt_ts, struct fq_codel_si *si)
138 {
139 	struct mbuf *m;
140 
141 next:	m = q->mq.head;
142 	if (m == NULL)
143 		return m;
144 	q->mq.head = m->m_nextpkt;
145 
146 	fq_update_stats(q, si, -m->m_pkthdr.len, 0);
147 
148 	if (si->main_q.ni.length == 0) /* queue is now idle */
149 			si->main_q.q_time = V_dn_cfg.curr_time;
150 
151 	/* extract packet timestamp*/
152 	struct m_tag *mtag;
153 	mtag = m_tag_locate(m, MTAG_ABI_COMPAT, DN_AQM_MTAG_TS, NULL);
154 	if (mtag == NULL){
155 		D("timestamp tag is not found!");
156 		*pkt_ts = 0;
157 	} else {
158 		*pkt_ts = *(aqm_time_t *)(mtag + 1);
159 		m_tag_delete(m,mtag);
160 	}
161 	if (m->m_pkthdr.rcvif != NULL &&
162 	    __predict_false(m_rcvif_restore(m) == NULL)) {
163 		m_freem(m);
164 		goto next;
165 	}
166 	return m;
167 }
168 
169 #endif
170