aboutsummaryrefslogtreecommitdiffstats
path: root/src/msgb.c
blob: 359a545bf0bd897533627b7073014a25d6f98f2a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
/* (C) 2008 by Harald Welte <laforge@gnumonks.org>
 * (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
 * All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

/*! \addtogroup msgb
 *  @{
 */

/*! \file msgb.c
 */

#include <unistd.h>
#include <string.h>
#include <stdlib.h>

#include <osmocom/core/msgb.h>
//#include <openbsc/gsm_data.h>
#include <osmocom/core/talloc.h>
//#include <openbsc/debug.h>

void *tall_msgb_ctx;

/*! \brief Allocate a new message buffer
 * \param[in] size Length in octets, including headroom
 * \param[in] name Human-readable name to be associated with msgb
 *
 * This function allocates a 'struct msgb' as well as the underlying
 * memory buffer for the actual message data (size specified by \a size)
 * using the talloc memory context previously set by \ref msgb_set_talloc_ctx
 */
struct msgb *msgb_alloc(uint16_t size, const char *name)
{
	struct msgb *msg;

	msg = _talloc_zero(tall_msgb_ctx, sizeof(*msg) + size, name);

	if (!msg) {
		//LOGP(DRSL, LOGL_FATAL, "unable to allocate msgb\n");
		return NULL;
	}

	msg->data_len = size;
	msg->len = 0;
	msg->data = msg->_data;
	msg->head = msg->_data;
	msg->tail = msg->_data;

	return msg;
}

/*! \brief Release given message buffer
 * \param[in] m Message buffer to be free'd
 */
void msgb_free(struct msgb *m)
{
	talloc_free(m);
}

/*! \brief Enqueue message buffer to tail of a queue
 * \param[in] queue linked list header of queue
 * \param[in] msg message buffer to be added to the queue
 *
 * The function will append the specified message buffer \a msg to the
 * queue implemented by \ref llist_head \a queue
 */
void msgb_enqueue(struct llist_head *queue, struct msgb *msg)
{
	llist_add_tail(&msg->list, queue);
}

/*! \brief Dequeue message buffer from head of queue
 * \param[in] queue linked list header of queue
 * \returns message buffer (if any) or NULL if queue empty
 *
 * The function will remove the first message buffer from the queue
 * implemented by \ref llist_head \a queue.
 */
struct msgb *msgb_dequeue(struct llist_head *queue)
{
	struct llist_head *lh;

	if (llist_empty(queue))
		return NULL;

	lh = queue->next;
	llist_del(lh);
	
	return llist_entry(lh, struct msgb, list);
}

/*! \brief Re-set all message buffer pointers
 *  \param[in] msg message buffer that is to be resetted
 *
 * This will re-set the various internal pointers into the underlying
 * message buffer, i.e. remvoe all headroom and treat the msgb as
 * completely empty.  It also initializes the control buffer to zero.
 */
void msgb_reset(struct msgb *msg)
{
	msg->len = 0;
	msg->data = msg->_data;
	msg->head = msg->_data;
	msg->tail = msg->_data;

	msg->trx = NULL;
	msg->lchan = NULL;
	msg->l2h = NULL;
	msg->l3h = NULL;
	msg->l4h = NULL;

	memset(&msg->cb, 0, sizeof(msg->cb));
}

/*! \brief get pointer to data section of message buffer
 *  \param[in] msg message buffer
 *  \returns pointer to data section of message buffer
 */
uint8_t *msgb_data(const struct msgb *msg)
{
	return msg->data;
}

/*! \brief get length of message buffer
 *  \param[in] msg message buffer
 *  \returns length of data section in message buffer
 */
uint16_t msgb_length(const struct msgb *msg)
{
	return msg->len;
}

/*! \brief Set the talloc context for \ref msgb_alloc
 *  \param[in] ctx talloc context to be used as root for msgb allocations
 */
void msgb_set_talloc_ctx(void *ctx)
{
	tall_msgb_ctx = ctx;
}

/*! @} */