sys/net/ifq.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-3-Clause
   3  *
   4  * Copyright (c) 1982, 1986, 1989, 1993
   5  *      The Regents of the University of California.  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  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/param.h>
  33 #include <sys/socket.h>
  34
  35 #ifndef ALTQ
  36 #define ALTQ    /* Needed for ifq.h prototypes only. */
  37 #endif
  38
  39 #include <net/if.h>
  40 #include <net/if_var.h>
  41 #include <net/if_private.h>
  42 #include <net/ifq.h>
  43
  44 int
  45 drbr_enqueue(struct ifnet *ifp, struct buf_ring *br, struct mbuf *m)
  46 {
  47         int error = 0;
  48
  49         if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
  50                 IFQ_ENQUEUE(&ifp->if_snd, m, error);
  51                 if (error)
  52                         if_inc_counter((ifp), IFCOUNTER_OQDROPS, 1);
  53                 return (error);
  54         }
  55         error = buf_ring_enqueue(br, m);
  56         if (error)
  57                 m_freem(m);
  58
  59         return (error);
  60 }
  61
  62 void
  63 drbr_putback(struct ifnet *ifp, struct buf_ring *br, struct mbuf *m_new)
  64 {
  65         /*
  66          * The top of the list needs to be swapped
  67          * for this one.
  68          */
  69         if (ifp != NULL && ALTQ_IS_ENABLED(&ifp->if_snd)) {
  70                 /*
  71                  * Peek in altq case dequeued it
  72                  * so put it back.
  73                  */
  74                 IFQ_DRV_PREPEND(&ifp->if_snd, m_new);
  75                 return;
  76         }
  77         buf_ring_putback_sc(br, m_new);
  78 }
  79
  80 struct mbuf *
  81 drbr_peek(struct ifnet *ifp, struct buf_ring *br)
  82 {
  83         struct mbuf *m;
  84         if (ifp != NULL && ALTQ_IS_ENABLED(&ifp->if_snd)) {
  85                 /*
  86                  * Pull it off like a dequeue
  87                  * since drbr_advance() does nothing
  88                  * for altq and drbr_putback() will
  89                  * use the old prepend function.
  90                  */
  91                 IFQ_DEQUEUE(&ifp->if_snd, m);
  92                 return (m);
  93         }
  94         return ((struct mbuf *)buf_ring_peek_clear_sc(br));
  95 }
  96
  97 void
  98 drbr_flush(struct ifnet *ifp, struct buf_ring *br)
  99 {
 100         struct mbuf *m;
 101
 102         if (ifp != NULL && ALTQ_IS_ENABLED(&ifp->if_snd))
 103                 IFQ_PURGE(&ifp->if_snd);
 104         while ((m = (struct mbuf *)buf_ring_dequeue_sc(br)) != NULL)
 105                 m_freem(m);
 106 }
 107
 108 struct mbuf *
 109 drbr_dequeue(struct ifnet *ifp, struct buf_ring *br)
 110 {
 111         struct mbuf *m;
 112
 113         if (ifp != NULL && ALTQ_IS_ENABLED(&ifp->if_snd)) {
 114                 IFQ_DEQUEUE(&ifp->if_snd, m);
 115                 return (m);
 116         }
 117         return ((struct mbuf *)buf_ring_dequeue_sc(br));
 118 }
 119
 120 void
 121 drbr_advance(struct ifnet *ifp, struct buf_ring *br)
 122 {
 123         /* Nothing to do here since peek dequeues in altq case */
 124         if (ifp != NULL && ALTQ_IS_ENABLED(&ifp->if_snd))
 125                 return;
 126         return (buf_ring_advance_sc(br));
 127 }
 128
 129 struct mbuf *
 130 drbr_dequeue_cond(struct ifnet *ifp, struct buf_ring *br,
 131     int (*func) (struct mbuf *, void *), void *arg)
 132 {
 133         struct mbuf *m;
 134         if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
 135                 IFQ_LOCK(&ifp->if_snd);
 136                 IFQ_POLL_NOLOCK(&ifp->if_snd, m);
 137                 if (m != NULL && func(m, arg) == 0) {
 138                         IFQ_UNLOCK(&ifp->if_snd);
 139                         return (NULL);
 140                 }
 141                 IFQ_DEQUEUE_NOLOCK(&ifp->if_snd, m);
 142                 IFQ_UNLOCK(&ifp->if_snd);
 143                 return (m);
 144         }
 145         m = (struct mbuf *)buf_ring_peek(br);
 146         if (m == NULL || func(m, arg) == 0)
 147                 return (NULL);
 148
 149         return ((struct mbuf *)buf_ring_dequeue_sc(br));
 150 }
 151
 152 int
 153 drbr_empty(struct ifnet *ifp, struct buf_ring *br)
 154 {
 155         if (ALTQ_IS_ENABLED(&ifp->if_snd))
 156                 return (IFQ_IS_EMPTY(&ifp->if_snd));
 157         return (buf_ring_empty(br));
 158 }
 159
 160 int
 161 drbr_needs_enqueue(struct ifnet *ifp, struct buf_ring *br)
 162 {
 163         if (ALTQ_IS_ENABLED(&ifp->if_snd))
 164                 return (1);
 165         return (!buf_ring_empty(br));
 166 }
 167
 168 int
 169 drbr_inuse(struct ifnet *ifp, struct buf_ring *br)
 170 {
 171         if (ALTQ_IS_ENABLED(&ifp->if_snd))
 172                 return (ifp->if_snd.ifq_len);
 173         return (buf_ring_count(br));
 174 }
 175