/* LWIP service - lnksock.c - link sockets */

/*

* This module contains absolutely minimal support for AF_LINK type sockets,

* because for now we need them only to support a specific set of IOCTLs, as

* required by for example ifconfig(8).

*/

#include "lwip.h"

/* The number of link sockets. */

#define NR_LNKSOCK 4

static struct lnksock {

struct sock lnk_sock; /* socket object, MUST be first */

SIMPLEQ_ENTRY(lnksock) lnk_next; /* next in free list */

} lnk_array[NR_LNKSOCK];

static SIMPLEQ_HEAD(, lnksock) lnk_freelist; /* list of free link sockets */

static const struct sockevent_ops lnksock_ops;

/*

* Initialize the link sockets module.

*/

void

lnksock_init(void)

{

unsigned int slot;

/* Initialize the list of free link sockets. */

SIMPLEQ_INIT(&lnk_freelist);

for (slot = 0; slot < __arraycount(lnk_array); slot++)

SIMPLEQ_INSERT_TAIL(&lnk_freelist, &lnk_array[slot], lnk_next);

}

/*

* Create a link socket.

*/

sockid_t

lnksock_socket(int type, int protocol, struct sock ** sockp,

const struct sockevent_ops ** ops)

{

struct lnksock *lnk;

if (type != SOCK_DGRAM)

return EPROTOTYPE;

if (protocol != 0)

return EPROTONOSUPPORT;

if (SIMPLEQ_EMPTY(&lnk_freelist))

return ENOBUFS;

lnk = SIMPLEQ_FIRST(&lnk_freelist);

SIMPLEQ_REMOVE_HEAD(&lnk_freelist, lnk_next);

*sockp = &lnk->lnk_sock;

*ops = &lnksock_ops;

return SOCKID_LNK | (sockid_t)(lnk - lnk_array);

}

/*

* Free up a closed link socket.

*/

static void

lnksock_free(struct sock * sock)

{

struct lnksock *lnk = (struct lnksock *)sock;

SIMPLEQ_INSERT_HEAD(&lnk_freelist, lnk, lnk_next);

}

static const struct sockevent_ops lnksock_ops = {

.sop_ioctl = ifconf_ioctl,

.sop_free = lnksock_free

};