xref: /freebsd/sys/net/ifq.c (revision 29363fb446372cb3f10bc98664e9767c53fbb457)
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
drbr_enqueue(struct ifnet * ifp,struct buf_ring * br,struct mbuf * m)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
drbr_putback(struct ifnet * ifp,struct buf_ring * br,struct mbuf * m_new)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 *
drbr_peek(struct ifnet * ifp,struct buf_ring * br)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
drbr_flush(struct ifnet * ifp,struct buf_ring * br)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 *
drbr_dequeue(struct ifnet * ifp,struct buf_ring * br)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
drbr_advance(struct ifnet * ifp,struct buf_ring * br)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 *
drbr_dequeue_cond(struct ifnet * ifp,struct buf_ring * br,int (* func)(struct mbuf *,void *),void * arg)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
drbr_empty(struct ifnet * ifp,struct buf_ring * br)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
drbr_needs_enqueue(struct ifnet * ifp,struct buf_ring * br)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
drbr_inuse(struct ifnet * ifp,struct buf_ring * br)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 
176