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/*
* lib/handlers.c default netlink message handlers
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation version 2.1
* of the License.
*
* Copyright (c) 2003-2008 Thomas Graf <tgraf@suug.ch>
*/
/**
* @ingroup core
* @defgroup cb Callbacks/Customization
*
* @details
* @par 1) Setting up a callback set
* @code
* // Allocate a callback set and initialize it to the verbose default set
* struct nl_cb *cb = nl_cb_alloc(NL_CB_VERBOSE);
*
* // Modify the set to call my_func() for all valid messages
* nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, my_func, NULL);
*
* // Set the error message handler to the verbose default implementation
* // and direct it to print all errors to the given file descriptor.
* FILE *file = fopen(...);
* nl_cb_err(cb, NL_CB_VERBOSE, NULL, file);
* @endcode
* @{
*/
#include <netlink-local.h>
#include <netlink/netlink.h>
#include <netlink/utils.h>
#include <netlink/msg.h>
#include <netlink/handlers.h>
/**
* @name Callback Handle Management
* @{
*/
/**
* Allocate a new callback handle
* @arg kind callback kind to be used for initialization
* @return Newly allocated callback handle or NULL
*/
struct nl_cb *nl_cb_alloc(enum nl_cb_kind kind)
{
int i;
struct nl_cb *cb;
if (kind < 0 || kind > NL_CB_KIND_MAX)
return NULL;
cb = calloc(1, sizeof(*cb));
if (!cb)
return NULL;
cb->cb_refcnt = 1;
for (i = 0; i <= NL_CB_TYPE_MAX; i++)
nl_cb_set(cb, i, kind, NULL, NULL);
nl_cb_err(cb, kind, NULL, NULL);
return cb;
}
/**
* Clone an existing callback handle
* @arg orig original callback handle
* @return Newly allocated callback handle being a duplicate of
* orig or NULL
*/
struct nl_cb *nl_cb_clone(struct nl_cb *orig)
{
struct nl_cb *cb;
cb = nl_cb_alloc(NL_CB_DEFAULT);
if (!cb)
return NULL;
memcpy(cb, orig, sizeof(*orig));
cb->cb_refcnt = 1;
return cb;
}
void nl_cb_put(struct nl_cb *cb)
{
if (!cb)
return;
cb->cb_refcnt--;
if (cb->cb_refcnt < 0)
BUG();
if (cb->cb_refcnt <= 0)
free(cb);
}
/** @} */
/**
* @name Callback Setup
* @{
*/
/**
* Set up a callback
* @arg cb callback set
* @arg type callback to modify
* @arg kind kind of implementation
* @arg func callback function (NL_CB_CUSTOM)
* @arg arg argument passed to callback
*
* @return 0 on success or a negative error code
*/
int nl_cb_set(struct nl_cb *cb, enum nl_cb_type type, enum nl_cb_kind kind,
nl_recvmsg_msg_cb_t func, void *arg)
{
if (type < 0 || type > NL_CB_TYPE_MAX)
return -NLE_RANGE;
if (kind < 0 || kind > NL_CB_KIND_MAX)
return -NLE_RANGE;
if (kind == NL_CB_CUSTOM) {
cb->cb_set[type] = func;
cb->cb_args[type] = arg;
}
return 0;
}
/**
* Set up an error callback
* @arg cb callback set
* @arg kind kind of callback
* @arg func callback function
* @arg arg argument to be passed to callback function
*/
int nl_cb_err(struct nl_cb *cb, enum nl_cb_kind kind,
nl_recvmsg_err_cb_t func, void *arg)
{
if (kind < 0 || kind > NL_CB_KIND_MAX)
return -NLE_RANGE;
if (kind == NL_CB_CUSTOM) {
cb->cb_err = func;
cb->cb_err_arg = arg;
}
return 0;
}
/** @} */
/** @} */
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