1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2010 Riccardo Panicucci, Luigi Rizzo, Universita` di Pisa 5 * All rights reserved 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 /* 30 * The API to write a packet scheduling algorithm for dummynet. 31 * 32 * $FreeBSD$ 33 */ 34 35 #ifndef _DN_SCHED_H 36 #define _DN_SCHED_H 37 38 #define DN_MULTIQUEUE 0x01 39 /* 40 * Descriptor for a scheduling algorithm. 41 * Contains all function pointers for a given scheduler 42 * This is typically created when a module is loaded, and stored 43 * in a global list of schedulers. 44 */ 45 struct dn_alg { 46 uint32_t type; /* the scheduler type */ 47 const char *name; /* scheduler name */ 48 uint32_t flags; /* DN_MULTIQUEUE if supports multiple queues */ 49 50 /* 51 * The following define the size of 3 optional data structures 52 * that may need to be allocated at runtime, and are appended 53 * to each of the base data structures: scheduler, sched.inst, 54 * and queue. We don't have a per-flowset structure. 55 */ 56 /* + parameters attached to the template, e.g. 57 * default queue sizes, weights, quantum size, and so on; 58 */ 59 size_t schk_datalen; 60 61 /* + per-instance parameters, such as timestamps, 62 * containers for queues, etc; 63 */ 64 size_t si_datalen; 65 66 size_t q_datalen; /* per-queue parameters (e.g. S,F) */ 67 68 /* 69 * Methods implemented by the scheduler: 70 * enqueue enqueue packet 'm' on scheduler 's', queue 'q'. 71 * q is NULL for !MULTIQUEUE. 72 * Return 0 on success, 1 on drop (packet consumed anyways). 73 * Note that q should be interpreted only as a hint 74 * on the flow that the mbuf belongs to: while a 75 * scheduler will normally enqueue m into q, it is ok 76 * to leave q alone and put the mbuf elsewhere. 77 * This function is called in two cases: 78 * - when a new packet arrives to the scheduler; 79 * - when a scheduler is reconfigured. In this case the 80 * call is issued by the new_queue callback, with a 81 * non empty queue (q) and m pointing to the first 82 * mbuf in the queue. For this reason, the function 83 * should internally check for (m != q->mq.head) 84 * before calling dn_enqueue(). 85 * 86 * dequeue Called when scheduler instance 's' can 87 * dequeue a packet. Return NULL if none are available. 88 * XXX what about non work-conserving ? 89 * 90 * config called on 'sched X config ...', normally writes 91 * in the area of size sch_arg 92 * 93 * destroy called on 'sched delete', frees everything 94 * in sch_arg (other parts are handled by more specific 95 * functions) 96 * 97 * new_sched called when a new instance is created, e.g. 98 * to create the local queue for !MULTIQUEUE, set V or 99 * copy parameters for WFQ, and so on. 100 * 101 * free_sched called when deleting an instance, cleans 102 * extra data in the per-instance area. 103 * 104 * new_fsk called when a flowset is linked to a scheduler, 105 * e.g. to validate parameters such as weights etc. 106 * free_fsk when a flowset is unlinked from a scheduler. 107 * (probably unnecessary) 108 * 109 * new_queue called to set the per-queue parameters, 110 * e.g. S and F, adjust sum of weights in the parent, etc. 111 * 112 * The new_queue callback is normally called from when 113 * creating a new queue. In some cases (such as a 114 * scheduler change or reconfiguration) it can be called 115 * with a non empty queue. In this case, the queue 116 * In case of non empty queue, the new_queue callback could 117 * need to call the enqueue function. In this case, 118 * the callback should eventually call enqueue() passing 119 * as m the first element in the queue. 120 * 121 * free_queue actions related to a queue removal, e.g. undo 122 * all the above. If the queue has data in it, also remove 123 * from the scheduler. This can e.g. happen during a reconfigure. 124 */ 125 int (*enqueue)(struct dn_sch_inst *, struct dn_queue *, 126 struct mbuf *); 127 struct mbuf * (*dequeue)(struct dn_sch_inst *); 128 129 int (*config)(struct dn_schk *); 130 int (*destroy)(struct dn_schk*); 131 int (*new_sched)(struct dn_sch_inst *); 132 int (*free_sched)(struct dn_sch_inst *); 133 int (*new_fsk)(struct dn_fsk *f); 134 int (*free_fsk)(struct dn_fsk *f); 135 int (*new_queue)(struct dn_queue *q); 136 int (*free_queue)(struct dn_queue *q); 137 #ifdef NEW_AQM 138 /* Getting scheduler extra parameters */ 139 int (*getconfig)(struct dn_schk *, struct dn_extra_parms *); 140 #endif 141 142 /* run-time fields */ 143 int ref_count; /* XXX number of instances in the system */ 144 SLIST_ENTRY(dn_alg) next; /* Next scheduler in the list */ 145 }; 146 147 /* MSVC does not support initializers so we need this ugly macro */ 148 #ifdef _WIN32 149 #define _SI(fld) 150 #else 151 #define _SI(fld) fld 152 #endif 153 154 /* 155 * Additionally, dummynet exports some functions and macros 156 * to be used by schedulers: 157 */ 158 159 void dn_free_pkts(struct mbuf *mnext); 160 int dn_enqueue(struct dn_queue *q, struct mbuf* m, int drop); 161 /* bound a variable between min and max */ 162 int ipdn_bound_var(int *v, int dflt, int lo, int hi, const char *msg); 163 164 /* 165 * Extract the head of a queue, update stats. Must be the very last 166 * thing done on a dequeue as the queue itself may go away. 167 */ 168 static __inline struct mbuf* 169 dn_dequeue(struct dn_queue *q) 170 { 171 struct mbuf *m = q->mq.head; 172 if (m == NULL) 173 return NULL; 174 #ifdef NEW_AQM 175 /* Call AQM dequeue function */ 176 if (q->fs->aqmfp && q->fs->aqmfp->dequeue ) 177 return q->fs->aqmfp->dequeue(q); 178 #endif 179 q->mq.head = m->m_nextpkt; 180 q->mq.count--; 181 182 /* Update stats for the queue */ 183 q->ni.length--; 184 q->ni.len_bytes -= m->m_pkthdr.len; 185 if (q->_si) { 186 q->_si->ni.length--; 187 q->_si->ni.len_bytes -= m->m_pkthdr.len; 188 } 189 if (q->ni.length == 0) /* queue is now idle */ 190 q->q_time = dn_cfg.curr_time; 191 return m; 192 } 193 194 int dn_sched_modevent(module_t mod, int cmd, void *arg); 195 196 #define DECLARE_DNSCHED_MODULE(name, dnsched) \ 197 static moduledata_t name##_mod = { \ 198 #name, dn_sched_modevent, dnsched \ 199 }; \ 200 DECLARE_MODULE(name, name##_mod, \ 201 SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY); \ 202 MODULE_DEPEND(name, dummynet, 3, 3, 3) 203 #endif /* _DN_SCHED_H */ 204