/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2010 Riccardo Panicucci, Universita` di Pisa * Copyright (c) 2000-2002 Luigi Rizzo, Universita` di Pisa * All rights reserved * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* */ #ifdef _KERNEL #include <sys/malloc.h> #include <sys/socket.h> #include <sys/socketvar.h> #include <sys/kernel.h> #include <sys/lock.h> #include <sys/mbuf.h> #include <sys/module.h> #include <sys/rwlock.h> #include <net/if.h> /* IFNAMSIZ */ #include <netinet/in.h> #include <netinet/ip_var.h> /* ipfw_rule_ref */ #include <netinet/ip_fw.h> /* flow_id */ #include <netinet/ip_dummynet.h> #include <netpfil/ipfw/ip_fw_private.h> #include <netpfil/ipfw/dn_heap.h> #include <netpfil/ipfw/ip_dn_private.h> #ifdef NEW_AQM #include <netpfil/ipfw/dn_aqm.h> #endif #include <netpfil/ipfw/dn_sched.h> #else #include <dn_test.h> #endif #ifndef MAX64 #define MAX64(x,y) (( (int64_t) ( (y)-(x) )) > 0 ) ? (y) : (x) #endif /* * timestamps are computed on 64 bit using fixed point arithmetic. * LMAX_BITS, WMAX_BITS are the max number of bits for the packet len * and sum of weights, respectively. FRAC_BITS is the number of * fractional bits. We want FRAC_BITS >> WMAX_BITS to avoid too large * errors when computing the inverse, FRAC_BITS < 32 so we can do 1/w * using an unsigned 32-bit division, and to avoid wraparounds we need * LMAX_BITS + WMAX_BITS + FRAC_BITS << 64 * As an example * FRAC_BITS = 26, LMAX_BITS=14, WMAX_BITS = 19 */ #ifndef FRAC_BITS #define FRAC_BITS 28 /* shift for fixed point arithmetic */ #define ONE_FP (1UL << FRAC_BITS) #endif /* * Private information for the scheduler instance: * sch_heap (key is Finish time) returns the next queue to serve * ne_heap (key is Start time) stores not-eligible queues * idle_heap (key=start/finish time) stores idle flows. It must * support extract-from-middle. * A flow is only in 1 of the three heaps. * XXX todo: use a more efficient data structure, e.g. a tree sorted * by F with min_subtree(S) in each node */ struct wf2qp_si { struct dn_heap sch_heap; /* top extract - key Finish time */ struct dn_heap ne_heap; /* top extract - key Start time */ struct dn_heap idle_heap; /* random extract - key Start=Finish time */ uint64_t V; /* virtual time */ uint32_t inv_wsum; /* inverse of sum of weights */ uint32_t wsum; /* sum of weights */ }; struct wf2qp_queue { struct dn_queue _q; uint64_t S, F; /* start time, finish time */ uint32_t inv_w; /* ONE_FP / weight */ int32_t heap_pos; /* position (index) of struct in heap */ }; /* * This file implements a WF2Q+ scheduler as it has been in dummynet * since 2000. * The scheduler supports per-flow queues and has O(log N) complexity. * * WF2Q+ needs to drain entries from the idle heap so that we * can keep the sum of weights up to date. We can do it whenever * we get a chance, or periodically, or following some other * strategy. The function idle_check() drains at most N elements * from the idle heap. */ static void idle_check(struct wf2qp_si *si, int n, int force) { struct dn_heap *h = &si->idle_heap; while (n-- > 0 && h->elements > 0 && (force || DN_KEY_LT(HEAP_TOP(h)->key, si->V))) { struct dn_queue *q = HEAP_TOP(h)->object; struct wf2qp_queue *alg_fq = (struct wf2qp_queue *)q; heap_extract(h, NULL); /* XXX to let the flowset delete the queue we should * mark it as 'unused' by the scheduler. */ alg_fq->S = alg_fq->F + 1; /* Mark timestamp as invalid. */ si->wsum -= q->fs->fs.par[0]; /* adjust sum of weights */ if (si->wsum > 0) si->inv_wsum = ONE_FP/si->wsum; } } static int wf2qp_enqueue(struct dn_sch_inst *_si, struct dn_queue *q, struct mbuf *m) { struct dn_fsk *fs = q->fs; struct wf2qp_si *si = (struct wf2qp_si *)(_si + 1); struct wf2qp_queue *alg_fq; uint64_t len = m->m_pkthdr.len; if (m != q->mq.head) { if (dn_enqueue(q, m, 0)) /* packet was dropped */ return 1; if (m != q->mq.head) /* queue was already busy */ return 0; } /* If reach this point, queue q was idle */ alg_fq = (struct wf2qp_queue *)q; if (DN_KEY_LT(alg_fq->F, alg_fq->S)) { /* F<S means timestamps are invalid ->brand new queue. */ alg_fq->S = si->V; /* init start time */ si->wsum += fs->fs.par[0]; /* add weight of new queue. */ si->inv_wsum = ONE_FP/si->wsum; } else { /* if it was idle then it was in the idle heap */ if (! heap_extract(&si->idle_heap, q)) return 1; alg_fq->S = MAX64(alg_fq->F, si->V); /* compute new S */ } alg_fq->F = alg_fq->S + len * alg_fq->inv_w; /* if nothing is backlogged, make sure this flow is eligible */ if (si->ne_heap.elements == 0 && si->sch_heap.elements == 0) si->V = MAX64(alg_fq->S, si->V); /* * Look at eligibility. A flow is not eligibile if S>V (when * this happens, it means that there is some other flow already * scheduled for the same pipe, so the sch_heap cannot be * empty). If the flow is not eligible we just store it in the * ne_heap. Otherwise, we store in the sch_heap. * Note that for all flows in sch_heap (SCH), S_i <= V, * and for all flows in ne_heap (NEH), S_i > V. * So when we need to compute max(V, min(S_i)) forall i in * SCH+NEH, we only need to look into NEH. */ if (DN_KEY_LT(si->V, alg_fq->S)) { /* S>V means flow Not eligible. */ if (si->sch_heap.elements == 0) D("++ ouch! not eligible but empty scheduler!"); heap_insert(&si->ne_heap, alg_fq->S, q); } else { heap_insert(&si->sch_heap, alg_fq->F, q); } return 0; } /* XXX invariant: sch > 0 || V >= min(S in neh) */ static struct mbuf * wf2qp_dequeue(struct dn_sch_inst *_si) { /* Access scheduler instance private data */ struct wf2qp_si *si = (struct wf2qp_si *)(_si + 1); struct mbuf *m; struct dn_queue *q; struct dn_heap *sch = &si->sch_heap; struct dn_heap *neh = &si->ne_heap; struct wf2qp_queue *alg_fq; if (sch->elements == 0 && neh->elements == 0) { /* we have nothing to do. We could kill the idle heap * altogether and reset V */ idle_check(si, 0x7fffffff, 1); si->V = 0; si->wsum = 0; /* should be set already */ return NULL; /* quick return if nothing to do */ } idle_check(si, 1, 0); /* drain something from the idle heap */ /* make sure at least one element is eligible, bumping V * and moving entries that have become eligible. * We need to repeat the first part twice, before and * after extracting the candidate, or enqueue() will * find the data structure in a wrong state. */ m = NULL; for(;;) { /* * Compute V = max(V, min(S_i)). Remember that all elements * in sch have by definition S_i <= V so if sch is not empty, * V is surely the max and we must not update it. Conversely, * if sch is empty we only need to look at neh. * We don't need to move the queues, as it will be done at the * next enqueue */ if (sch->elements == 0 && neh->elements > 0) { si->V = MAX64(si->V, HEAP_TOP(neh)->key); } while (neh->elements > 0 && DN_KEY_LEQ(HEAP_TOP(neh)->key, si->V)) { q = HEAP_TOP(neh)->object; alg_fq = (struct wf2qp_queue *)q; heap_extract(neh, NULL); heap_insert(sch, alg_fq->F, q); } if (m) /* pkt found in previous iteration */ break; /* ok we have at least one eligible pkt */ q = HEAP_TOP(sch)->object; alg_fq = (struct wf2qp_queue *)q; m = dn_dequeue(q); if (m == NULL) return NULL; heap_extract(sch, NULL); /* Remove queue from heap. */ si->V += (uint64_t)(m->m_pkthdr.len) * si->inv_wsum; alg_fq->S = alg_fq->F; /* Update start time. */ if (q->mq.head == 0) { /* not backlogged any more. */ heap_insert(&si->idle_heap, alg_fq->F, q); } else { /* Still backlogged. */ /* Update F, store in neh or sch */ uint64_t len = q->mq.head->m_pkthdr.len; alg_fq->F += len * alg_fq->inv_w; if (DN_KEY_LEQ(alg_fq->S, si->V)) { heap_insert(sch, alg_fq->F, q); } else { heap_insert(neh, alg_fq->S, q); } } } return m; } static int wf2qp_new_sched(struct dn_sch_inst *_si) { struct wf2qp_si *si = (struct wf2qp_si *)(_si + 1); int ofs = offsetof(struct wf2qp_queue, heap_pos); /* all heaps support extract from middle */ if (heap_init(&si->idle_heap, 16, ofs) || heap_init(&si->sch_heap, 16, ofs) || heap_init(&si->ne_heap, 16, ofs)) { heap_free(&si->ne_heap); heap_free(&si->sch_heap); heap_free(&si->idle_heap); return ENOMEM; } return 0; } static int wf2qp_free_sched(struct dn_sch_inst *_si) { struct wf2qp_si *si = (struct wf2qp_si *)(_si + 1); heap_free(&si->sch_heap); heap_free(&si->ne_heap); heap_free(&si->idle_heap); return 0; } static int wf2qp_new_fsk(struct dn_fsk *fs) { ipdn_bound_var(&fs->fs.par[0], 1, 1, 100, "WF2Q+ weight"); return 0; } static int wf2qp_new_queue(struct dn_queue *_q) { struct wf2qp_queue *q = (struct wf2qp_queue *)_q; _q->ni.oid.subtype = DN_SCHED_WF2QP; q->F = 0; /* not strictly necessary */ q->S = q->F + 1; /* mark timestamp as invalid. */ q->inv_w = ONE_FP / _q->fs->fs.par[0]; if (_q->mq.head != NULL) { wf2qp_enqueue(_q->_si, _q, _q->mq.head); } return 0; } /* * Called when the infrastructure removes a queue (e.g. flowset * is reconfigured). Nothing to do if we did not 'own' the queue, * otherwise remove it from the right heap and adjust the sum * of weights. */ static int wf2qp_free_queue(struct dn_queue *q) { struct wf2qp_queue *alg_fq = (struct wf2qp_queue *)q; struct wf2qp_si *si = (struct wf2qp_si *)(q->_si + 1); if (alg_fq->S >= alg_fq->F + 1) return 0; /* nothing to do, not in any heap */ si->wsum -= q->fs->fs.par[0]; if (si->wsum > 0) si->inv_wsum = ONE_FP/si->wsum; /* extract from the heap. XXX TODO we may need to adjust V * to make sure the invariants hold. */ heap_extract(&si->idle_heap, q); heap_extract(&si->ne_heap, q); heap_extract(&si->sch_heap, q); return 0; } /* * WF2Q+ scheduler descriptor * contains the type of the scheduler, the name, the size of the * structures and function pointers. */ static struct dn_alg wf2qp_desc = { _SI( .type = ) DN_SCHED_WF2QP, _SI( .name = ) "WF2Q+", _SI( .flags = ) DN_MULTIQUEUE, /* we need extra space in the si and the queue */ _SI( .schk_datalen = ) 0, _SI( .si_datalen = ) sizeof(struct wf2qp_si), _SI( .q_datalen = ) sizeof(struct wf2qp_queue) - sizeof(struct dn_queue), _SI( .enqueue = ) wf2qp_enqueue, _SI( .dequeue = ) wf2qp_dequeue, _SI( .config = ) NULL, _SI( .destroy = ) NULL, _SI( .new_sched = ) wf2qp_new_sched, _SI( .free_sched = ) wf2qp_free_sched, _SI( .new_fsk = ) wf2qp_new_fsk, _SI( .free_fsk = ) NULL, _SI( .new_queue = ) wf2qp_new_queue, _SI( .free_queue = ) wf2qp_free_queue, #ifdef NEW_AQM _SI( .getconfig = ) NULL, #endif }; DECLARE_DNSCHED_MODULE(dn_wf2qp, &wf2qp_desc);
