libosmocore/src/msgb.c

157 lines
4.0 KiB
C

/* (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] msgb 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] m 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;
}
/*! }@ */