xref: /freebsd/sys/dev/wtap/if_medium.c (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
1 /*-
2  * Copyright (c) 2010-2011 Monthadar Al Jaberi, TerraNet AB
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer,
10  *    without modification.
11  * 2. Redistributions in binary form must reproduce at minimum a disclaimer
12  *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
13  *    redistribution must be conditioned upon including a substantially
14  *    similar Disclaimer requirement for further binary redistribution.
15  *
16  * NO WARRANTY
17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19  * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
20  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21  * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
22  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
25  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
27  * THE POSSIBILITY OF SUCH DAMAGES.
28  *
29  * $FreeBSD$
30  */
31 #include "if_wtapvar.h"
32 #include "if_medium.h"
33 
34 void
35 init_medium(struct wtap_medium *md)
36 {
37 
38 	DWTAP_PRINTF("%s\n", __func__);
39 	STAILQ_INIT(&md->md_pktbuf);
40 	mtx_init(&md->md_mtx, "wtap_medium mtx", NULL, MTX_DEF | MTX_RECURSE);
41 
42 	/* Event handler for sending packets between wtaps */
43 	struct eventhandler *eh = (struct eventhandler *)
44 	    malloc(sizeof(struct eventhandler), M_WTAP, M_NOWAIT | M_ZERO);
45 	eh->tq = taskqueue_create("wtap_tx_taskq",  M_NOWAIT | M_ZERO,
46 	    taskqueue_thread_enqueue, &eh->tq);
47 	taskqueue_start_threads(&eh->tq, 1, PI_NET, "%s taskq", "wtap_medium");
48 	md->tx_handler = eh;
49 	/* Mark medium closed by default */
50 	md->open = 0;
51 }
52 
53 void
54 deinit_medium(struct wtap_medium *md)
55 {
56 
57 	DWTAP_PRINTF("%s\n", __func__);
58 	taskqueue_free(md->tx_handler->tq);
59 	free(md->tx_handler, M_WTAP);
60 }
61 
62 int
63 medium_transmit(struct wtap_medium *md, int id, struct mbuf*m)
64 {
65 
66 	mtx_lock(&md->md_mtx);
67 	if (md->open == 0){
68 		DWTAP_PRINTF("[%d] dropping m=%p\n", id, m);
69 		m_free(m);
70 		mtx_unlock(&md->md_mtx);
71 		return 0;
72 	}
73 
74 	DWTAP_PRINTF("[%d] transmiting m=%p\n", id, m);
75 	struct packet *p = (struct packet *)malloc(sizeof(struct packet),
76 	    M_WTAP_PACKET, M_ZERO | M_NOWAIT);
77 	p->id = id;
78 	p->m = m;
79 
80 	STAILQ_INSERT_TAIL(&md->md_pktbuf, p, pf_list);
81 	taskqueue_enqueue(md->tx_handler->tq, &md->tx_handler->proc);
82 	mtx_unlock(&md->md_mtx);
83 
84       return 0;
85 }
86 
87 struct packet *
88 medium_get_next_packet(struct wtap_medium *md)
89 {
90 	struct packet *p;
91 
92 	mtx_lock(&md->md_mtx);
93 	p = STAILQ_FIRST(&md->md_pktbuf);
94 	if (p == NULL){
95 		mtx_unlock(&md->md_mtx);
96 		return NULL;
97 	}
98 
99 	STAILQ_REMOVE_HEAD(&md->md_pktbuf, pf_list);
100 	mtx_unlock(&md->md_mtx);
101 	return p;
102 }
103 
104 void
105 medium_open(struct wtap_medium *md)
106 {
107 
108 	mtx_lock(&md->md_mtx);
109 	md->open = 1;
110 	mtx_unlock(&md->md_mtx);
111 }
112 
113 void
114 medium_close(struct wtap_medium *md)
115 {
116 
117 	mtx_lock(&md->md_mtx);
118 	md->open = 0;
119 	mtx_unlock(&md->md_mtx);
120 }
121