/*
* The helper functions make Andrew Brown's interface really
* shine. It makes possible to create value on the fly whether
* the sysctl value is read or written.
*
* As shown as an example in the man page, the first step is to
* create a copy of the node to have sysctl_lookup work on it.
*
* Here, we have more work to do than just a copy, since we have
* to create the string. The first step is to collect the actual
* value of the node, which is a convenient pointer to the softc
* of the interface. From there we create the string and use it
* as the value, but only for the *copy* of the node.
*
* Then we let sysctl_lookup do the magic, which consists in
* setting oldp and newp as required by the operation. When the
* value is read, that means that the string will be copied to
* the user, and when it is written, the new value will be copied
* over in the addr array.
*
* If newp is NULL, the user was reading the value, so we don't
* have anything else to do. If a new value was written, we
* have to check it.
*
* If it is incorrect, we can return an error and leave 'node' as
* it is: since it is a copy of the actual node, the change will
* be forgotten.
*
* Upon a correct input, we commit the change to the ifnet
* structure of our interface.
*/
static int
tap_sysctl_handler(SYSCTLFN_ARGS)
{
struct sysctlnode node;
struct tap_softc *sc;
struct ifnet *ifp;
int error;
size_t len;
char addr[3 * ETHER_ADDR_LEN];
uint8_t enaddr[ETHER_ADDR_LEN];
node = *rnode;
sc = node.sysctl_data;
ifp = &sc->sc_ec.ec_if;
(void)ether_snprintf(addr, sizeof(addr), CLLADDR(ifp->if_sadl));
node.sysctl_data = addr;
error = sysctl_lookup(SYSCTLFN_CALL(&node));
if (error || newp == NULL)
return (error);
len = strlen(addr);
if (len < 11 || len > 17)
return (EINVAL);
/* Commit change */
if (ether_aton_r(enaddr, sizeof(enaddr), addr) != 0)
return (EINVAL);
if_set_sadl(ifp, enaddr, ETHER_ADDR_LEN, false);
return (error);
}
void
eco_ifattach(struct ifnet *ifp, const uint8_t *lla)
{
struct ecocom *ec = (void *)ifp;
ifp->if_type = IFT_ECONET;
ifp->if_addrlen = ECO_ADDR_LEN;
ifp->if_hdrlen = ECO_HDR_LEN;
ifp->if_dlt = DLT_ECONET;
ifp->if_mtu = ECO_MTU;
ifp->if_output = eco_output;
ifp->if_input = eco_input;
ifp->if_start = eco_start;
ifp->if_ioctl = eco_ioctl;
/* ifp->if_baudrate...; */
if_set_sadl(ifp, lla, ECO_ADDR_LEN, FALSE);
ifp->if_broadcastaddr = eco_broadcastaddr;
LIST_INIT(&ec->ec_retries);
bpf_attach(ifp, ifp->if_dlt, ECO_HDR_LEN);
}
/*
* Helper function to set Ethernet address. This has been replaced by
* the generic SIOCALIFADDR ioctl on a PF_LINK socket.
*/
static int
tap_lifaddr(struct ifnet *ifp, u_long cmd, struct ifaliasreq *ifra)
{
const struct sockaddr *sa = &ifra->ifra_addr;
if (sa->sa_family != AF_LINK)
return (EINVAL);
if_set_sadl(ifp, sa->sa_data, ETHER_ADDR_LEN, false);
return (0);
}
