if_medium.c revision 330897 
1145522Sdarrenr/*-
2145522Sdarrenr * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
353642Sguido *
4255332Scy * Copyright (c) 2010-2011 Monthadar Al Jaberi, TerraNet AB
553642Sguido * All rights reserved.
680482Sdarrenr *
753642Sguido * Redistribution and use in source and binary forms, with or without
853642Sguido * modification, are permitted provided that the following conditions
957126Sguido * are met:
10172776Sdarrenr * 1. Redistributions of source code must retain the above copyright
1153642Sguido *    notice, this list of conditions and the following disclaimer,
1253642Sguido *    without modification.
1353642Sguido * 2. Redistributions in binary form must reproduce at minimum a disclaimer
1453642Sguido *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
1553642Sguido *    redistribution must be conditioned upon including a substantially
16255332Scy *    similar Disclaimer requirement for further binary redistribution.
1753642Sguido *
18255332Scy * NO WARRANTY
19145522Sdarrenr * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20255332Scy * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
22 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
23 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
24 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
27 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
29 * THE POSSIBILITY OF SUCH DAMAGES.
30 *
31 * $FreeBSD: stable/11/sys/dev/wtap/if_medium.c 330897 2018-03-14 03:19:51Z eadler $
32 */
33#include "if_wtapvar.h"
34#include "if_medium.h"
35
36void
37init_medium(struct wtap_medium *md)
38{
39
40	DWTAP_PRINTF("%s\n", __func__);
41	STAILQ_INIT(&md->md_pktbuf);
42	mtx_init(&md->md_mtx, "wtap_medium mtx", NULL, MTX_DEF | MTX_RECURSE);
43
44	/* Event handler for sending packets between wtaps */
45	struct eventhandler *eh = (struct eventhandler *)
46	    malloc(sizeof(struct eventhandler), M_WTAP, M_NOWAIT | M_ZERO);
47	eh->tq = taskqueue_create("wtap_tx_taskq",  M_NOWAIT | M_ZERO,
48	    taskqueue_thread_enqueue, &eh->tq);
49	taskqueue_start_threads(&eh->tq, 1, PI_NET, "%s taskq", "wtap_medium");
50	md->tx_handler = eh;
51	/* Mark medium closed by default */
52	md->open = 0;
53}
54
55void
56deinit_medium(struct wtap_medium *md)
57{
58
59	DWTAP_PRINTF("%s\n", __func__);
60	taskqueue_free(md->tx_handler->tq);
61	free(md->tx_handler, M_WTAP);
62}
63
64int
65medium_transmit(struct wtap_medium *md, int id, struct mbuf*m)
66{
67
68	mtx_lock(&md->md_mtx);
69	if (md->open == 0){
70		DWTAP_PRINTF("[%d] dropping m=%p\n", id, m);
71		m_free(m);
72		mtx_unlock(&md->md_mtx);
73		return 0;
74	}
75
76	DWTAP_PRINTF("[%d] transmiting m=%p\n", id, m);
77	struct packet *p = (struct packet *)malloc(sizeof(struct packet),
78	    M_WTAP_PACKET, M_ZERO | M_NOWAIT);
79	p->id = id;
80	p->m = m;
81
82	STAILQ_INSERT_TAIL(&md->md_pktbuf, p, pf_list);
83	taskqueue_enqueue(md->tx_handler->tq, &md->tx_handler->proc);
84	mtx_unlock(&md->md_mtx);
85
86      return 0;
87}
88
89struct packet *
90medium_get_next_packet(struct wtap_medium *md)
91{
92	struct packet *p;
93
94	mtx_lock(&md->md_mtx);
95	p = STAILQ_FIRST(&md->md_pktbuf);
96	if (p == NULL){
97		mtx_unlock(&md->md_mtx);
98		return NULL;
99	}
100
101	STAILQ_REMOVE_HEAD(&md->md_pktbuf, pf_list);
102	mtx_unlock(&md->md_mtx);
103	return p;
104}
105
106void
107medium_open(struct wtap_medium *md)
108{
109
110	mtx_lock(&md->md_mtx);
111	md->open = 1;
112	mtx_unlock(&md->md_mtx);
113}
114
115void
116medium_close(struct wtap_medium *md)
117{
118
119	mtx_lock(&md->md_mtx);
120	md->open = 0;
121	mtx_unlock(&md->md_mtx);
122}
123