static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
struct msghdr *msg, size_t len,
int flags)
{
struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
struct scm_cookie scm;
struct sock *sk = sock->sk;
struct netlink_opt *nlk = nlk_sk(sk);
int noblock = flags&MSG_DONTWAIT;
size_t copied;
struct sk_buff *skb;
int err;
if (flags&MSG_OOB)
return -EOPNOTSUPP;
copied = 0;
skb = skb_recv_datagram(sk,flags,noblock,&err);
if (skb==NULL)
goto out;
msg->msg_namelen = 0;
copied = skb->len;
if (len < copied) {
msg->msg_flags |= MSG_TRUNC;
copied = len;
}
skb->h.raw = skb->data;
err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
if (msg->msg_name) {
struct sockaddr_nl *addr = (struct sockaddr_nl*)msg->msg_name;
addr->nl_family = AF_NETLINK;
addr->nl_pad = 0;
addr->nl_pid = NETLINK_CB(skb).pid;
addr->nl_groups = NETLINK_CB(skb).dst_groups;
msg->msg_namelen = sizeof(*addr);
}
if (NULL == siocb->scm) {
memset(&scm, 0, sizeof(scm));
siocb->scm = &scm;
}
siocb->scm->creds = *NETLINK_CREDS(skb);
skb_free_datagram(sk, skb);
if (nlk->cb && atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2)
netlink_dump(sk);
scm_recv(sock, msg, siocb->scm, flags);
out:
netlink_rcv_wake(sk);
return err ? : copied;
}
static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, int len,
int flags, struct scm_cookie *scm)
{
struct sock *sk = sock->sk;
int noblock = flags&MSG_DONTWAIT;
int copied;
struct sk_buff *skb;
int err;
if (flags&MSG_OOB)
return -EOPNOTSUPP;
copied = 0;
skb = skb_recv_datagram(sk,flags,noblock,&err);
if (skb==NULL)
goto out;
msg->msg_namelen = 0;
copied = skb->len;
if (len < copied) {
msg->msg_flags |= MSG_TRUNC;
copied = len;
}
skb->h.raw = skb->data;
err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
if (msg->msg_name) {
struct sockaddr_nl *addr = (struct sockaddr_nl*)msg->msg_name;
addr->nl_family = AF_NETLINK;
addr->nl_pid = NETLINK_CB(skb).pid;
addr->nl_groups = NETLINK_CB(skb).dst_groups;
msg->msg_namelen = sizeof(*addr);
}
scm->creds = *NETLINK_CREDS(skb);
skb_free_datagram(sk, skb);
if (sk->protinfo.af_netlink->cb
&& atomic_read(&sk->rmem_alloc) <= sk->rcvbuf/2)
netlink_dump(sk);
out:
if (skb_queue_len(&sk->receive_queue) <= sk->rcvbuf/2) {
if (skb_queue_len(&sk->receive_queue) == 0)
clear_bit(0, &sk->protinfo.af_netlink->state);
if (!test_bit(0, &sk->protinfo.af_netlink->state))
wake_up_interruptible(&sk->protinfo.af_netlink->wait);
}
return err ? : copied;
}
int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
struct nlmsghdr *nlh,
int (*dump)(struct sk_buff *skb, struct netlink_callback*),
int (*done)(struct netlink_callback*))
{
struct netlink_callback *cb;
struct sock *sk;
struct netlink_opt *nlk;
cb = kmalloc(sizeof(*cb), GFP_KERNEL);
if (cb == NULL)
return -ENOBUFS;
memset(cb, 0, sizeof(*cb));
cb->dump = dump;
cb->done = done;
cb->nlh = nlh;
atomic_inc(&skb->users);
cb->skb = skb;
sk = netlink_lookup(ssk->sk_protocol, NETLINK_CB(skb).pid);
if (sk == NULL) {
netlink_destroy_callback(cb);
return -ECONNREFUSED;
}
nlk = nlk_sk(sk);
/* A dump is in progress... */
spin_lock(&nlk->cb_lock);
if (nlk->cb) {
spin_unlock(&nlk->cb_lock);
netlink_destroy_callback(cb);
sock_put(sk);
return -EBUSY;
}
nlk->cb = cb;
spin_unlock(&nlk->cb_lock);
netlink_dump(sk);
return 0;
}
