ndhc/netlink.h

// Copyright 2011-2018 Nicholas J. Kain <njkain at gmail dot com>
// SPDX-License-Identifier: MIT
#ifndef NK_NETLINK_H_
#define NK_NETLINK_H_

#include <stdbool.h>
#include <linux/rtnetlink.h>
#include "state.h"

enum {
    IFS_NONE = 0,
    IFS_UP,
    IFS_DOWN,
    IFS_SHUT,
    IFS_REMOVED
};

bool nl_event_carrier_wentup(int state);
int nl_event_get(struct client_state_t *cs);
int nl_getifdata(void);

#endif
Relicense as MIT. It's a lot more common than BSD 2-clause it is both compatible and nearly identical in effect. 2022-02-07 06:35:29 +05:30			`// Copyright 2011-2018 Nicholas J. Kain <njkain at gmail dot com>`
			`// SPDX-License-Identifier: MIT`
Rewrite the netlink handling code to use libmnl. The size cost is very small, and it is hard to do netlink completely correctly as it is poorly documented. 2011-07-02 11:04:50 +05:30			`#ifndef NK_NETLINK_H_`
			`#define NK_NETLINK_H_`

Remove ifsPrevState and set non-infinite timeout on a send error. We instead check carrier status as needed. This approach is more robust. For a simple example, imagine link state changes that happen while the machine is suspended. 2017-01-12 16:35:00 +05:30			`#include <stdbool.h>`
Make sure that the netlink socket will never block after program initialization. Fetching if/address/index/mac mappings is done only once at program init, so it is done synchronously as an exception to this rule. Rewrite the netlink handling. Now uses NIH code that should be safe, small, and correct. No external deps FTW. 2011-07-04 03:00:55 +05:30			`#include <linux/rtnetlink.h>`
Rewrite the netlink handling code to use libmnl. The size cost is very small, and it is hard to do netlink completely correctly as it is poorly documented. 2011-07-02 11:04:50 +05:30			`#include "state.h"`

Only bring down the interface at startup time if it is not already up and running. ndhc does its job entirely with raw sockets before a lease is established, so it will work just fine, and this change allows for the dhcp client to be re-run without causing downtime on an interface. 2011-07-02 14:28:58 +05:30			`enum {`
			`IFS_NONE = 0,`
			`IFS_UP,`
			`IFS_DOWN,`
			`IFS_SHUT,`
			`IFS_REMOVED`
			`};`

Remove ifsPrevState and set non-infinite timeout on a send error. We instead check carrier status as needed. This approach is more robust. For a simple example, imagine link state changes that happen while the machine is suspended. 2017-01-12 16:35:00 +05:30			`bool nl_event_carrier_wentup(int state);`
Replace mostly obsolete -[static 1] with reliable old *-. This notation originally had the sole advantage of implying that the pointer was non-NULL, but it has seen little use and now clang presents warnings about it in certain contexts. 2022-01-12 09:05:19 +05:30			`int nl_event_get(struct client_state_t *cs);`
Functions don't need explicit extern linkage in headers in C99, as it is the default. Standardize on leaving out the extern keyword as it is less clutter. 2014-03-18 07:40:58 +05:30			`int nl_getifdata(void);`
Rewrite the netlink handling code to use libmnl. The size cost is very small, and it is hard to do netlink completely correctly as it is poorly documented. 2011-07-02 11:04:50 +05:30
Relicense as MIT. It's a lot more common than BSD 2-clause it is both compatible and nearly identical in effect. 2022-02-07 06:35:29 +05:30			`#endif`