FreeBSD/Linux Kernel Cross Reference
sys/netpfil/ipfw/dn_sched_prio.c

     /*
      * Copyright (c) 2010 Riccardo Panicucci, 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.
     */
    
    /*
     * $FreeBSD: releng/10.1/sys/netpfil/ipfw/dn_sched_prio.c 240494 2012-09-14 11:51:49Z glebius $
     */
    #ifdef _KERNEL
    #include <sys/malloc.h>
    #include <sys/socket.h>
    #include <sys/socketvar.h>
    #include <sys/kernel.h>
    #include <sys/mbuf.h>
    #include <sys/module.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/dn_heap.h>
    #include <netpfil/ipfw/ip_dn_private.h>
    #include <netpfil/ipfw/dn_sched.h>
    #else
    #include <dn_test.h>
    #endif
    
    #define DN_SCHED_PRIO   5 //XXX
    
    #if !defined(_KERNEL) || !defined(__linux__)
    #define test_bit(ix, pData)     ((*pData) & (1<<(ix)))
    #define __set_bit(ix, pData)    (*pData) |= (1<<(ix))
    #define __clear_bit(ix, pData)  (*pData) &= ~(1<<(ix))
    #endif
    
    #ifdef __MIPSEL__
    #define __clear_bit(ix, pData)  (*pData) &= ~(1<<(ix))
    #endif
    
    /* Size of the array of queues pointers. */
    #define BITMAP_T        unsigned long
    #define MAXPRIO         (sizeof(BITMAP_T) * 8)
    
    /*
     * The scheduler instance contains an array of pointers to queues,
     * one for each priority, and a bitmap listing backlogged queues.
     */
    struct prio_si {
            BITMAP_T bitmap;                        /* array bitmap */
            struct dn_queue *q_array[MAXPRIO];      /* Array of queues pointers */
    };
    
    /*
     * If a queue with the same priority is already backlogged, use
     * that one instead of the queue passed as argument.
     */
    static int 
    prio_enqueue(struct dn_sch_inst *_si, struct dn_queue *q, struct mbuf *m)
    {
            struct prio_si *si = (struct prio_si *)(_si + 1);
            int prio = q->fs->fs.par[0];
    
            if (test_bit(prio, &si->bitmap) == 0) {
                    /* No queue with this priority, insert */
                    __set_bit(prio, &si->bitmap);
                    si->q_array[prio] = q;
            } else { /* use the existing queue */
                    q = si->q_array[prio];
            }
            if (dn_enqueue(q, m, 0))
                    return 1;
            return 0;
    }
    
    /*
     * Packets are dequeued only from the highest priority queue.
     * The function ffs() return the lowest bit in the bitmap that rapresent
     * the array index (-1) which contains the pointer to the highest priority
    * queue.
    * After the dequeue, if this queue become empty, it is index is removed
    * from the bitmap.
    * Scheduler is idle if the bitmap is empty
    *
    * NOTE: highest priority is 0, lowest is sched->max_prio_q
    */
   static struct mbuf *
   prio_dequeue(struct dn_sch_inst *_si)
   {
           struct prio_si *si = (struct prio_si *)(_si + 1);
           struct mbuf *m;
           struct dn_queue *q;
           int prio;
   
           if (si->bitmap == 0) /* scheduler idle */
                   return NULL;
   
           prio = ffs(si->bitmap) - 1;
   
           /* Take the highest priority queue in the scheduler */
           q = si->q_array[prio];
           // assert(q)
   
           m = dn_dequeue(q);
           if (q->mq.head == NULL) {
                   /* Queue is now empty, remove from scheduler
                    * and mark it
                    */
                   si->q_array[prio] = NULL;
                   __clear_bit(prio, &si->bitmap);
           }
           return m;
   }
   
   static int
   prio_new_sched(struct dn_sch_inst *_si)
   {
           struct prio_si *si = (struct prio_si *)(_si + 1);
   
           bzero(si->q_array, sizeof(si->q_array));
           si->bitmap = 0;
   
           return 0;
   }
   
   static int
   prio_new_fsk(struct dn_fsk *fs)
   {
           /* Check if the prioritiy is between 0 and MAXPRIO-1 */
           ipdn_bound_var(&fs->fs.par[0], 0, 0, MAXPRIO - 1, "PRIO priority");
           return 0;
   }
   
   static int
   prio_new_queue(struct dn_queue *q)
   {
           struct prio_si *si = (struct prio_si *)(q->_si + 1);
           int prio = q->fs->fs.par[0];
           struct dn_queue *oldq;
   
           q->ni.oid.subtype = DN_SCHED_PRIO;
   
           if (q->mq.head == NULL)
                   return 0;
   
           /* Queue already full, must insert in the scheduler or append
            * mbufs to existing queue. This partly duplicates prio_enqueue
            */
           if (test_bit(prio, &si->bitmap) == 0) {
                   /* No queue with this priority, insert */
                   __set_bit(prio, &si->bitmap);
                   si->q_array[prio] = q;
           } else if ( (oldq = si->q_array[prio]) != q) {
                   /* must append to the existing queue.
                    * can simply append q->mq.head to q2->...
                    * and add the counters to those of q2
                    */
                   oldq->mq.tail->m_nextpkt = q->mq.head;
                   oldq->mq.tail = q->mq.tail;
                   oldq->ni.length += q->ni.length;
                   q->ni.length = 0;
                   oldq->ni.len_bytes += q->ni.len_bytes;
                   q->ni.len_bytes = 0;
                   q->mq.tail = q->mq.head = NULL;
           }
           return 0;
   }
   
   static int
   prio_free_queue(struct dn_queue *q)
   {
           int prio = q->fs->fs.par[0];
           struct prio_si *si = (struct prio_si *)(q->_si + 1);
   
           if (si->q_array[prio] == q) {
                   si->q_array[prio] = NULL;
                   __clear_bit(prio, &si->bitmap);
           }
           return 0;
   }
   
   
   static struct dn_alg prio_desc = {
           _SI( .type = ) DN_SCHED_PRIO,
           _SI( .name = ) "PRIO",
           _SI( .flags = ) DN_MULTIQUEUE,
   
           /* we need extra space in the si and the queue */
           _SI( .schk_datalen = ) 0,
           _SI( .si_datalen = ) sizeof(struct prio_si),
           _SI( .q_datalen = ) 0,
   
           _SI( .enqueue = ) prio_enqueue,
           _SI( .dequeue = ) prio_dequeue,
   
           _SI( .config = )  NULL,
           _SI( .destroy = )  NULL,
           _SI( .new_sched = ) prio_new_sched,
           _SI( .free_sched = ) NULL,
   
           _SI( .new_fsk = ) prio_new_fsk,
           _SI( .free_fsk = )  NULL,
   
           _SI( .new_queue = ) prio_new_queue,
           _SI( .free_queue = ) prio_free_queue,
   };
   
   
   DECLARE_DNSCHED_MODULE(dn_prio, &prio_desc);

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