/**
* llc_ui_autobind - Bind a socket to a specific address.
* @sk: Socket to bind an address to.
* @addr: Address the user wants the socket bound to.
*
* Bind a socket to a specific address. For llc a user is able to bind to
* a specific sap only or mac + sap. If the user only specifies a sap and
* a null dmac (all zeros) the user is attempting to bind to an entire
* sap. This will stop anyone else on the local system from using that
* sap. If someone else has a mac + sap open the bind to null + sap will
* fail.
* If the user desires to bind to a specific mac + sap, it is possible to
* have multiple sap connections via multiple macs.
* Bind and autobind for that matter must enforce the correct sap usage
* otherwise all hell will break loose.
* Returns: 0 upon success, negative otherwise.
*/
static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
{
struct sock *sk = sock->sk;
struct llc_sock *llc = llc_sk(sk);
struct llc_sap *sap;
int rc = -EINVAL;
if (!sock_flag(sk, SOCK_ZAPPED))
goto out;
rc = -ENODEV;
llc->dev = dev_getfirstbyhwtype(addr->sllc_arphrd);
if (!llc->dev)
goto out;
rc = -EUSERS;
llc->laddr.lsap = llc_ui_autoport();
if (!llc->laddr.lsap)
goto out;
rc = -EBUSY; /* some other network layer is using the sap */
sap = llc_sap_open(llc->laddr.lsap, NULL);
if (!sap)
goto out;
memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
memcpy(&llc->addr, addr, sizeof(llc->addr));
/* assign new connection to its SAP */
llc_sap_add_socket(sap, sk);
sock_reset_flag(sk, SOCK_ZAPPED);
rc = 0;
out:
return rc;
}
static int dgram_sendmsg(struct kiocb *iocb, struct sock *sk,
struct msghdr *msg, size_t size)
{
struct net_device *dev;
unsigned int mtu;
struct sk_buff *skb;
struct ieee802154_mac_cb *cb;
struct dgram_sock *ro = dgram_sk(sk);
struct ieee802154_addr dst_addr;
int hlen, tlen;
int err;
if (msg->msg_flags & MSG_OOB) {
pr_debug("msg->msg_flags = 0x%x\n", msg->msg_flags);
return -EOPNOTSUPP;
}
if (!ro->connected && !msg->msg_name)
return -EDESTADDRREQ;
else if (ro->connected && msg->msg_name)
return -EISCONN;
if (!ro->bound)
dev = dev_getfirstbyhwtype(sock_net(sk), ARPHRD_IEEE802154);
else
dev = ieee802154_get_dev(sock_net(sk), &ro->src_addr);
if (!dev) {
pr_debug("no dev\n");
err = -ENXIO;
goto out;
}
mtu = dev->mtu;
pr_debug("name = %s, mtu = %u\n", dev->name, mtu);
if (size > mtu) {
pr_debug("size = %Zu, mtu = %u\n", size, mtu);
err = -EMSGSIZE;
goto out_dev;
}
hlen = LL_RESERVED_SPACE(dev);
tlen = dev->needed_tailroom;
skb = sock_alloc_send_skb(sk, hlen + tlen + size,
msg->msg_flags & MSG_DONTWAIT,
&err);
if (!skb)
goto out_dev;
skb_reserve(skb, hlen);
skb_reset_network_header(skb);
cb = mac_cb_init(skb);
cb->type = IEEE802154_FC_TYPE_DATA;
cb->ackreq = ro->want_ack;
if (msg->msg_name) {
DECLARE_SOCKADDR(struct sockaddr_ieee802154*,
daddr, msg->msg_name);
ieee802154_addr_from_sa(&dst_addr, &daddr->addr);
} else {
