struct sock *
netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len))
{
struct socket *sock;
struct sock *sk;
if (!nl_table)
return NULL;
if (unit<0 || unit>=MAX_LINKS)
return NULL;
if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
return NULL;
if (netlink_create(sock, unit) < 0) {
sock_release(sock);
return NULL;
}
sk = sock->sk;
sk->sk_data_ready = netlink_data_ready;
if (input)
nlk_sk(sk)->data_ready = input;
if (netlink_insert(sk, 0)) {
sock_release(sock);
return NULL;
}
return sk;
}
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;
}
struct sock *
netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len))
{
struct socket *sock;
struct sock *sk;
if (unit<0 || unit>=MAX_LINKS)
return NULL;
if (!(sock = sock_alloc()))
return NULL;
sock->type = SOCK_RAW;
if (netlink_create(sock, unit) < 0) {
sock_release(sock);
return NULL;
}
sk = sock->sk;
sk->data_ready = netlink_data_ready;
if (input)
sk->protinfo.af_netlink->data_ready = input;
netlink_insert(sk, 0);
return sk;
}
static int netlink_autobind(struct socket *sock)
{
struct sock *sk = sock->sk;
struct sock *osk;
s32 pid = current->pid;
int err;
retry:
netlink_table_grab();
for (osk=nl_table[sk->protocol]; osk; osk=osk->next) {
if (osk->protinfo.af_netlink->pid == pid) {
/* Bind collision, search negative pid values. */
if (pid > 0)
pid = -4096;
pid--;
netlink_table_ungrab();
goto retry;
}
}
netlink_table_ungrab();
err = netlink_insert(sk, pid);
if (err == -EADDRINUSE)
goto retry;
sk->protinfo.af_netlink->groups = 0;
return 0;
}
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;
}
