static int netlink_connect(struct socket *sock, struct sockaddr *addr,
int alen, int flags)
{
int err = 0;
struct sock *sk = sock->sk;
struct sockaddr_nl *nladdr=(struct sockaddr_nl*)addr;
if (addr->sa_family == AF_UNSPEC) {
sk->protinfo.af_netlink->dst_pid = 0;
sk->protinfo.af_netlink->dst_groups = 0;
return 0;
}
if (addr->sa_family != AF_NETLINK)
return -EINVAL;
/* Only superuser is allowed to send multicasts */
if (nladdr->nl_groups && !capable(CAP_NET_ADMIN))
return -EPERM;
if (!sk->protinfo.af_netlink->pid)
err = netlink_autobind(sock);
if (err == 0) {
sk->protinfo.af_netlink->dst_pid = nladdr->nl_pid;
sk->protinfo.af_netlink->dst_groups = nladdr->nl_groups;
}
return 0;
}
static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
{
struct sock *sk = sock->sk;
int err;
struct sockaddr_nl *nladdr=(struct sockaddr_nl *)addr;
if (nladdr->nl_family != AF_NETLINK)
return -EINVAL;
/* Only superuser is allowed to listen multicasts */
if (nladdr->nl_groups && !capable(CAP_NET_ADMIN))
return -EPERM;
if (sk->protinfo.af_netlink->pid) {
if (nladdr->nl_pid != sk->protinfo.af_netlink->pid)
return -EINVAL;
sk->protinfo.af_netlink->groups = nladdr->nl_groups;
return 0;
}
if (nladdr->nl_pid == 0) {
err = netlink_autobind(sock);
if (err == 0)
sk->protinfo.af_netlink->groups = nladdr->nl_groups;
return err;
}
err = netlink_insert(sk, nladdr->nl_pid);
if (err == 0)
sk->protinfo.af_netlink->groups = nladdr->nl_groups;
return err;
}
static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
struct msghdr *msg, size_t len)
{
struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
struct sock *sk = sock->sk;
struct netlink_opt *nlk = nlk_sk(sk);
struct sockaddr_nl *addr=msg->msg_name;
u32 dst_pid;
u32 dst_groups;
struct sk_buff *skb;
int err;
struct scm_cookie scm;
if (msg->msg_flags&MSG_OOB)
return -EOPNOTSUPP;
if (NULL == siocb->scm)
siocb->scm = &scm;
err = scm_send(sock, msg, siocb->scm);
if (err < 0)
return err;
if (msg->msg_namelen) {
if (addr->nl_family != AF_NETLINK)
return -EINVAL;
dst_pid = addr->nl_pid;
dst_groups = addr->nl_groups;
if (dst_groups && !netlink_capable(sock, NL_NONROOT_SEND))
return -EPERM;
} else {
dst_pid = nlk->dst_pid;
dst_groups = nlk->dst_groups;
}
if (!nlk->pid) {
err = netlink_autobind(sock);
if (err)
goto out;
}
err = -EMSGSIZE;
if (len > sk->sk_sndbuf - 32)
goto out;
err = -ENOBUFS;
skb = alloc_skb(len, GFP_KERNEL);
if (skb==NULL)
goto out;
NETLINK_CB(skb).pid = nlk->pid;
NETLINK_CB(skb).groups = nlk->groups;
NETLINK_CB(skb).dst_pid = dst_pid;
NETLINK_CB(skb).dst_groups = dst_groups;
memcpy(NETLINK_CREDS(skb), &siocb->scm->creds, sizeof(struct ucred));
/* What can I do? Netlink is asynchronous, so that
we will have to save current capabilities to
check them, when this message will be delivered
to corresponding kernel module. --ANK (980802)
*/
err = -EFAULT;
if (memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len)) {
kfree_skb(skb);
goto out;
}
err = security_netlink_send(sk, skb);
if (err) {
kfree_skb(skb);
goto out;
}
if (dst_groups) {
atomic_inc(&skb->users);
netlink_broadcast(sk, skb, dst_pid, dst_groups, GFP_KERNEL);
}
err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
out:
return err;
}
static int netlink_release(struct socket *sock)
{
struct sock *sk = sock->sk;
struct netlink_opt *nlk;
if (!sk)
return 0;
netlink_remove(sk);
nlk = nlk_sk(sk);
spin_lock(&nlk->cb_lock);
if (nlk->cb) {
nlk->cb->done(nlk->cb);
netlink_destroy_callback(nlk->cb);
nlk->cb = NULL;
__sock_put(sk);
}
spin_unlock(&nlk->cb_lock);
/* OK. Socket is unlinked, and, therefore,
no new packets will arrive */
sock_orphan(sk);
sock->sk = NULL;
wake_up_interruptible_all(&nlk->wait);
skb_queue_purge(&sk->sk_write_queue);
if (nlk->pid && !nlk->groups) {
struct netlink_notify n = {
.protocol = sk->sk_protocol,
.pid = nlk->pid,
};
notifier_call_chain(&netlink_chain, NETLINK_URELEASE, &n);
}
sock_put(sk);
return 0;
}
static int netlink_autobind(struct socket *sock)
{
struct sock *sk = sock->sk;
struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
struct hlist_head *head;
struct sock *osk;
struct hlist_node *node;
s32 pid = current->pid;
int err;
static s32 rover = -4097;
retry:
cond_resched();
netlink_table_grab();
head = nl_pid_hashfn(hash, pid);
sk_for_each(osk, node, head) {
if (nlk_sk(osk)->pid == pid) {
/* Bind collision, search negative pid values. */
pid = rover--;
if (rover > -4097)
rover = -4097;
netlink_table_ungrab();
goto retry;
}
}
netlink_table_ungrab();
err = netlink_insert(sk, pid);
if (err == -EADDRINUSE)
goto retry;
nlk_sk(sk)->groups = 0;
return 0;
}
static inline int netlink_capable(struct socket *sock, unsigned int flag)
{
return (nl_nonroot[sock->sk->sk_protocol] & flag) ||
capable(CAP_NET_ADMIN);
}
static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
{
struct sock *sk = sock->sk;
struct netlink_opt *nlk = nlk_sk(sk);
struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
int err;
if (nladdr->nl_family != AF_NETLINK)
return -EINVAL;
/* Only superuser is allowed to listen multicasts */
if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_RECV))
return -EPERM;
if (nlk->pid) {
if (nladdr->nl_pid != nlk->pid)
return -EINVAL;
} else {
err = nladdr->nl_pid ?
netlink_insert(sk, nladdr->nl_pid) :
netlink_autobind(sock);
if (err)
return err;
}
if (!nladdr->nl_groups && !nlk->groups)
return 0;
netlink_table_grab();
if (nlk->groups && !nladdr->nl_groups)
__sk_del_bind_node(sk);
else if (!nlk->groups && nladdr->nl_groups)
sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
nlk->groups = nladdr->nl_groups;
netlink_table_ungrab();
return 0;
}
static int netlink_connect(struct socket *sock, struct sockaddr *addr,
int alen, int flags)
{
int err = 0;
struct sock *sk = sock->sk;
struct netlink_opt *nlk = nlk_sk(sk);
struct sockaddr_nl *nladdr=(struct sockaddr_nl*)addr;
if (addr->sa_family == AF_UNSPEC) {
sk->sk_state = NETLINK_UNCONNECTED;
nlk->dst_pid = 0;
nlk->dst_groups = 0;
return 0;
}
if (addr->sa_family != AF_NETLINK)
return -EINVAL;
/* Only superuser is allowed to send multicasts */
if (nladdr->nl_groups && !netlink_capable(sock, NL_NONROOT_SEND))
return -EPERM;
if (!nlk->pid)
err = netlink_autobind(sock);
if (err == 0) {
sk->sk_state = NETLINK_CONNECTED;
nlk->dst_pid = nladdr->nl_pid;
nlk->dst_groups = nladdr->nl_groups;
}
return err;
}
static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, int len,
struct scm_cookie *scm)
{
struct sock *sk = sock->sk;
struct sockaddr_nl *addr=msg->msg_name;
u32 dst_pid;
u32 dst_groups;
struct sk_buff *skb;
int err;
if (msg->msg_flags&MSG_OOB)
return -EOPNOTSUPP;
if (msg->msg_namelen) {
if (addr->nl_family != AF_NETLINK)
return -EINVAL;
dst_pid = addr->nl_pid;
dst_groups = addr->nl_groups;
if (dst_groups && !capable(CAP_NET_ADMIN))
return -EPERM;
} else {
dst_pid = sk->protinfo.af_netlink->dst_pid;
dst_groups = sk->protinfo.af_netlink->dst_groups;
}
if (!sk->protinfo.af_netlink->pid) {
err = netlink_autobind(sock);
if (err)
goto out;
}
err = -EMSGSIZE;
if ((unsigned)len > sk->sndbuf-32)
goto out;
err = -ENOBUFS;
skb = alloc_skb(len, GFP_KERNEL);
if (skb==NULL)
goto out;
NETLINK_CB(skb).pid = sk->protinfo.af_netlink->pid;
NETLINK_CB(skb).groups = sk->protinfo.af_netlink->groups;
NETLINK_CB(skb).dst_pid = dst_pid;
NETLINK_CB(skb).dst_groups = dst_groups;
memcpy(NETLINK_CREDS(skb), &scm->creds, sizeof(struct ucred));
/* What can I do? Netlink is asynchronous, so that
we will have to save current capabilities to
check them, when this message will be delivered
to corresponding kernel module. --ANK (980802)
*/
NETLINK_CB(skb).eff_cap = current->cap_effective;
err = -EFAULT;
if (memcpy_fromiovec(skb_put(skb,len), msg->msg_iov, len)) {
kfree_skb(skb);
goto out;
}
if (dst_groups) {
atomic_inc(&skb->users);
netlink_broadcast(sk, skb, dst_pid, dst_groups, GFP_KERNEL);
}
err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
out:
return err;
}
