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/*
* Copyright (c) 2009, 2010 Nicira Networks.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <config.h>
#include "rtnetlink-link.h"
#include <sys/socket.h>
#include <linux/rtnetlink.h>
#include <net/if.h>
#include "netlink.h"
#include "netlink-notifier.h"
#include "ofpbuf.h"
static struct nln *nln = NULL;
static struct rtnetlink_link_change rtn_change;
/* Parses a rtnetlink message 'buf' into 'change'. If 'buf' is unparseable,
* leaves 'change' untouched and returns false. Otherwise, populates 'change'
* and returns true. */
bool
rtnetlink_link_parse(struct ofpbuf *buf,
struct rtnetlink_link_change *change)
{
bool parsed;
/* Policy for RTNLGRP_LINK messages.
*
* There are *many* more fields in these messages, but currently we
* only care about these fields. */
static const struct nl_policy policy[] = {
[IFLA_IFNAME] = { .type = NL_A_STRING, .optional = false },
[IFLA_MASTER] = { .type = NL_A_U32, .optional = true },
};
static struct nlattr *attrs[ARRAY_SIZE(policy)];
parsed = nl_policy_parse(buf, NLMSG_HDRLEN + sizeof(struct ifinfomsg),
policy, attrs, ARRAY_SIZE(policy));
if (parsed) {
const struct nlmsghdr *nlmsg;
const struct ifinfomsg *ifinfo;
nlmsg = buf->data;
ifinfo = ((const struct ifinfomsg *)
((const char *) buf->data + NLMSG_HDRLEN));
change->nlmsg_type = nlmsg->nlmsg_type;
change->ifi_index = ifinfo->ifi_index;
change->ifname = nl_attr_get_string(attrs[IFLA_IFNAME]);
change->running = ifinfo->ifi_flags & IFF_RUNNING;
change->master_ifindex = (attrs[IFLA_MASTER]
? nl_attr_get_u32(attrs[IFLA_MASTER])
: 0);
}
return parsed;
}
static bool
rtnetlink_link_parse_cb(struct ofpbuf *buf, void *change)
{
return rtnetlink_link_parse(buf, change);
}
/* Registers 'cb' to be called with auxiliary data 'aux' with network device
* change notifications. The notifier is stored in 'notifier', which the
* caller must not modify or free.
*
* This is probably not the function that you want. You should probably be
* using dpif_port_poll() or netdev_change_seq(), which unlike this function
* are not Linux-specific.
*
* Returns an initialized nln_notifier if successful, NULL otherwise. */
struct nln_notifier *
rtnetlink_link_notifier_create(rtnetlink_link_notify_func *cb, void *aux)
{
if (!nln) {
nln = nln_create(NETLINK_ROUTE, RTNLGRP_LINK, rtnetlink_link_parse_cb,
&rtn_change);
}
return nln_notifier_create(nln, (nln_notify_func *) cb, aux);
}
/* Destroys 'notifier', which must have previously been created with
* rtnetlink_link_notifier_register(). */
void
rtnetlink_link_notifier_destroy(struct nln_notifier *notifier)
{
nln_notifier_destroy(notifier);
}
/* Calls all of the registered notifiers, passing along any as-yet-unreported
* netdev change events. */
void
rtnetlink_link_run(void)
{
if (nln) {
nln_run(nln);
}
}
/* Causes poll_block() to wake up when network device change notifications are
* ready. */
void
rtnetlink_link_wait(void)
{
if (nln) {
nln_wait(nln);
}
}
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