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-rw-r--r--net/netlink/Makefile5
-rw-r--r--net/netlink/af_netlink.c1994
-rw-r--r--net/netlink/attr.c467
-rw-r--r--net/netlink/genetlink.c792
4 files changed, 3258 insertions, 0 deletions
diff --git a/net/netlink/Makefile b/net/netlink/Makefile
new file mode 100644
index 0000000..e3589c2
--- /dev/null
+++ b/net/netlink/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for the netlink driver.
+#
+
+obj-y := af_netlink.o attr.o genetlink.o
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
new file mode 100644
index 0000000..480184a
--- /dev/null
+++ b/net/netlink/af_netlink.c
@@ -0,0 +1,1994 @@
+/*
+ * NETLINK Kernel-user communication protocol.
+ *
+ * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk>
+ * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ * Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith
+ * added netlink_proto_exit
+ * Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br>
+ * use nlk_sk, as sk->protinfo is on a diet 8)
+ * Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org>
+ * - inc module use count of module that owns
+ * the kernel socket in case userspace opens
+ * socket of same protocol
+ * - remove all module support, since netlink is
+ * mandatory if CONFIG_NET=y these days
+ */
+
+#include <linux/module.h>
+
+#include <linux/capability.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/stat.h>
+#include <linux/socket.h>
+#include <linux/un.h>
+#include <linux/fcntl.h>
+#include <linux/termios.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <asm/uaccess.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/notifier.h>
+#include <linux/security.h>
+#include <linux/jhash.h>
+#include <linux/jiffies.h>
+#include <linux/random.h>
+#include <linux/bitops.h>
+#include <linux/mm.h>
+#include <linux/types.h>
+#include <linux/audit.h>
+#include <linux/mutex.h>
+
+#include <net/net_namespace.h>
+#include <net/sock.h>
+#include <net/scm.h>
+#include <net/netlink.h>
+
+#define NLGRPSZ(x) (ALIGN(x, sizeof(unsigned long) * 8) / 8)
+#define NLGRPLONGS(x) (NLGRPSZ(x)/sizeof(unsigned long))
+
+struct netlink_sock {
+ /* struct sock has to be the first member of netlink_sock */
+ struct sock sk;
+ u32 pid;
+ u32 dst_pid;
+ u32 dst_group;
+ u32 flags;
+ u32 subscriptions;
+ u32 ngroups;
+ unsigned long *groups;
+ unsigned long state;
+ wait_queue_head_t wait;
+ struct netlink_callback *cb;
+ struct mutex *cb_mutex;
+ struct mutex cb_def_mutex;
+ void (*netlink_rcv)(struct sk_buff *skb);
+ struct module *module;
+};
+
+#define NETLINK_KERNEL_SOCKET 0x1
+#define NETLINK_RECV_PKTINFO 0x2
+
+static inline struct netlink_sock *nlk_sk(struct sock *sk)
+{
+ return container_of(sk, struct netlink_sock, sk);
+}
+
+static inline int netlink_is_kernel(struct sock *sk)
+{
+ return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET;
+}
+
+struct nl_pid_hash {
+ struct hlist_head *table;
+ unsigned long rehash_time;
+
+ unsigned int mask;
+ unsigned int shift;
+
+ unsigned int entries;
+ unsigned int max_shift;
+
+ u32 rnd;
+};
+
+struct netlink_table {
+ struct nl_pid_hash hash;
+ struct hlist_head mc_list;
+ unsigned long *listeners;
+ unsigned int nl_nonroot;
+ unsigned int groups;
+ struct mutex *cb_mutex;
+ struct module *module;
+ int registered;
+};
+
+static struct netlink_table *nl_table;
+
+static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
+
+static int netlink_dump(struct sock *sk);
+static void netlink_destroy_callback(struct netlink_callback *cb);
+
+static DEFINE_RWLOCK(nl_table_lock);
+static atomic_t nl_table_users = ATOMIC_INIT(0);
+
+static ATOMIC_NOTIFIER_HEAD(netlink_chain);
+
+static u32 netlink_group_mask(u32 group)
+{
+ return group ? 1 << (group - 1) : 0;
+}
+
+static struct hlist_head *nl_pid_hashfn(struct nl_pid_hash *hash, u32 pid)
+{
+ return &hash->table[jhash_1word(pid, hash->rnd) & hash->mask];
+}
+
+static void netlink_sock_destruct(struct sock *sk)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ if (nlk->cb) {
+ if (nlk->cb->done)
+ nlk->cb->done(nlk->cb);
+ netlink_destroy_callback(nlk->cb);
+ }
+
+ skb_queue_purge(&sk->sk_receive_queue);
+
+ if (!sock_flag(sk, SOCK_DEAD)) {
+ printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
+ return;
+ }
+
+ WARN_ON(atomic_read(&sk->sk_rmem_alloc));
+ WARN_ON(atomic_read(&sk->sk_wmem_alloc));
+ WARN_ON(nlk_sk(sk)->groups);
+}
+
+/* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
+ * SMP. Look, when several writers sleep and reader wakes them up, all but one
+ * immediately hit write lock and grab all the cpus. Exclusive sleep solves
+ * this, _but_ remember, it adds useless work on UP machines.
+ */
+
+static void netlink_table_grab(void)
+ __acquires(nl_table_lock)
+{
+ write_lock_irq(&nl_table_lock);
+
+ if (atomic_read(&nl_table_users)) {
+ DECLARE_WAITQUEUE(wait, current);
+
+ add_wait_queue_exclusive(&nl_table_wait, &wait);
+ for (;;) {
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ if (atomic_read(&nl_table_users) == 0)
+ break;
+ write_unlock_irq(&nl_table_lock);
+ schedule();
+ write_lock_irq(&nl_table_lock);
+ }
+
+ __set_current_state(TASK_RUNNING);
+ remove_wait_queue(&nl_table_wait, &wait);
+ }
+}
+
+static void netlink_table_ungrab(void)
+ __releases(nl_table_lock)
+{
+ write_unlock_irq(&nl_table_lock);
+ wake_up(&nl_table_wait);
+}
+
+static inline void
+netlink_lock_table(void)
+{
+ /* read_lock() synchronizes us to netlink_table_grab */
+
+ read_lock(&nl_table_lock);
+ atomic_inc(&nl_table_users);
+ read_unlock(&nl_table_lock);
+}
+
+static inline void
+netlink_unlock_table(void)
+{
+ if (atomic_dec_and_test(&nl_table_users))
+ wake_up(&nl_table_wait);
+}
+
+static inline struct sock *netlink_lookup(struct net *net, int protocol,
+ u32 pid)
+{
+ struct nl_pid_hash *hash = &nl_table[protocol].hash;
+ struct hlist_head *head;
+ struct sock *sk;
+ struct hlist_node *node;
+
+ read_lock(&nl_table_lock);
+ head = nl_pid_hashfn(hash, pid);
+ sk_for_each(sk, node, head) {
+ if (net_eq(sock_net(sk), net) && (nlk_sk(sk)->pid == pid)) {
+ sock_hold(sk);
+ goto found;
+ }
+ }
+ sk = NULL;
+found:
+ read_unlock(&nl_table_lock);
+ return sk;
+}
+
+static inline struct hlist_head *nl_pid_hash_zalloc(size_t size)
+{
+ if (size <= PAGE_SIZE)
+ return kzalloc(size, GFP_ATOMIC);
+ else
+ return (struct hlist_head *)
+ __get_free_pages(GFP_ATOMIC | __GFP_ZERO,
+ get_order(size));
+}
+
+static inline void nl_pid_hash_free(struct hlist_head *table, size_t size)
+{
+ if (size <= PAGE_SIZE)
+ kfree(table);
+ else
+ free_pages((unsigned long)table, get_order(size));
+}
+
+static int nl_pid_hash_rehash(struct nl_pid_hash *hash, int grow)
+{
+ unsigned int omask, mask, shift;
+ size_t osize, size;
+ struct hlist_head *otable, *table;
+ int i;
+
+ omask = mask = hash->mask;
+ osize = size = (mask + 1) * sizeof(*table);
+ shift = hash->shift;
+
+ if (grow) {
+ if (++shift > hash->max_shift)
+ return 0;
+ mask = mask * 2 + 1;
+ size *= 2;
+ }
+
+ table = nl_pid_hash_zalloc(size);
+ if (!table)
+ return 0;
+
+ otable = hash->table;
+ hash->table = table;
+ hash->mask = mask;
+ hash->shift = shift;
+ get_random_bytes(&hash->rnd, sizeof(hash->rnd));
+
+ for (i = 0; i <= omask; i++) {
+ struct sock *sk;
+ struct hlist_node *node, *tmp;
+
+ sk_for_each_safe(sk, node, tmp, &otable[i])
+ __sk_add_node(sk, nl_pid_hashfn(hash, nlk_sk(sk)->pid));
+ }
+
+ nl_pid_hash_free(otable, osize);
+ hash->rehash_time = jiffies + 10 * 60 * HZ;
+ return 1;
+}
+
+static inline int nl_pid_hash_dilute(struct nl_pid_hash *hash, int len)
+{
+ int avg = hash->entries >> hash->shift;
+
+ if (unlikely(avg > 1) && nl_pid_hash_rehash(hash, 1))
+ return 1;
+
+ if (unlikely(len > avg) && time_after(jiffies, hash->rehash_time)) {
+ nl_pid_hash_rehash(hash, 0);
+ return 1;
+ }
+
+ return 0;
+}
+
+static const struct proto_ops netlink_ops;
+
+static void
+netlink_update_listeners(struct sock *sk)
+{
+ struct netlink_table *tbl = &nl_table[sk->sk_protocol];
+ struct hlist_node *node;
+ unsigned long mask;
+ unsigned int i;
+
+ for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
+ mask = 0;
+ sk_for_each_bound(sk, node, &tbl->mc_list) {
+ if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
+ mask |= nlk_sk(sk)->groups[i];
+ }
+ tbl->listeners[i] = mask;
+ }
+ /* this function is only called with the netlink table "grabbed", which
+ * makes sure updates are visible before bind or setsockopt return. */
+}
+
+static int netlink_insert(struct sock *sk, struct net *net, u32 pid)
+{
+ struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
+ struct hlist_head *head;
+ int err = -EADDRINUSE;
+ struct sock *osk;
+ struct hlist_node *node;
+ int len;
+
+ netlink_table_grab();
+ head = nl_pid_hashfn(hash, pid);
+ len = 0;
+ sk_for_each(osk, node, head) {
+ if (net_eq(sock_net(osk), net) && (nlk_sk(osk)->pid == pid))
+ break;
+ len++;
+ }
+ if (node)
+ goto err;
+
+ err = -EBUSY;
+ if (nlk_sk(sk)->pid)
+ goto err;
+
+ err = -ENOMEM;
+ if (BITS_PER_LONG > 32 && unlikely(hash->entries >= UINT_MAX))
+ goto err;
+
+ if (len && nl_pid_hash_dilute(hash, len))
+ head = nl_pid_hashfn(hash, pid);
+ hash->entries++;
+ nlk_sk(sk)->pid = pid;
+ sk_add_node(sk, head);
+ err = 0;
+
+err:
+ netlink_table_ungrab();
+ return err;
+}
+
+static void netlink_remove(struct sock *sk)
+{
+ netlink_table_grab();
+ if (sk_del_node_init(sk))
+ nl_table[sk->sk_protocol].hash.entries--;
+ if (nlk_sk(sk)->subscriptions)
+ __sk_del_bind_node(sk);
+ netlink_table_ungrab();
+}
+
+static struct proto netlink_proto = {
+ .name = "NETLINK",
+ .owner = THIS_MODULE,
+ .obj_size = sizeof(struct netlink_sock),
+};
+
+static int __netlink_create(struct net *net, struct socket *sock,
+ struct mutex *cb_mutex, int protocol)
+{
+ struct sock *sk;
+ struct netlink_sock *nlk;
+
+ sock->ops = &netlink_ops;
+
+ sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto);
+ if (!sk)
+ return -ENOMEM;
+
+ sock_init_data(sock, sk);
+
+ nlk = nlk_sk(sk);
+ if (cb_mutex)
+ nlk->cb_mutex = cb_mutex;
+ else {
+ nlk->cb_mutex = &nlk->cb_def_mutex;
+ mutex_init(nlk->cb_mutex);
+ }
+ init_waitqueue_head(&nlk->wait);
+
+ sk->sk_destruct = netlink_sock_destruct;
+ sk->sk_protocol = protocol;
+ return 0;
+}
+
+static int netlink_create(struct net *net, struct socket *sock, int protocol)
+{
+ struct module *module = NULL;
+ struct mutex *cb_mutex;
+ struct netlink_sock *nlk;
+ int err = 0;
+
+ sock->state = SS_UNCONNECTED;
+
+ if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
+ return -ESOCKTNOSUPPORT;
+
+ if (protocol < 0 || protocol >= MAX_LINKS)
+ return -EPROTONOSUPPORT;
+
+ netlink_lock_table();
+#ifdef CONFIG_MODULES
+ if (!nl_table[protocol].registered) {
+ netlink_unlock_table();
+ request_module("net-pf-%d-proto-%d", PF_NETLINK, protocol);
+ netlink_lock_table();
+ }
+#endif
+ if (nl_table[protocol].registered &&
+ try_module_get(nl_table[protocol].module))
+ module = nl_table[protocol].module;
+ cb_mutex = nl_table[protocol].cb_mutex;
+ netlink_unlock_table();
+
+ err = __netlink_create(net, sock, cb_mutex, protocol);
+ if (err < 0)
+ goto out_module;
+
+ nlk = nlk_sk(sock->sk);
+ nlk->module = module;
+out:
+ return err;
+
+out_module:
+ module_put(module);
+ goto out;
+}
+
+static int netlink_release(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct netlink_sock *nlk;
+
+ if (!sk)
+ return 0;
+
+ netlink_remove(sk);
+ sock_orphan(sk);
+ nlk = nlk_sk(sk);
+
+ /*
+ * OK. Socket is unlinked, any packets that arrive now
+ * will be purged.
+ */
+
+ sock->sk = NULL;
+ wake_up_interruptible_all(&nlk->wait);
+
+ skb_queue_purge(&sk->sk_write_queue);
+
+ if (nlk->pid && !nlk->subscriptions) {
+ struct netlink_notify n = {
+ .net = sock_net(sk),
+ .protocol = sk->sk_protocol,
+ .pid = nlk->pid,
+ };
+ atomic_notifier_call_chain(&netlink_chain,
+ NETLINK_URELEASE, &n);
+ }
+
+ module_put(nlk->module);
+
+ netlink_table_grab();
+ if (netlink_is_kernel(sk)) {
+ BUG_ON(nl_table[sk->sk_protocol].registered == 0);
+ if (--nl_table[sk->sk_protocol].registered == 0) {
+ kfree(nl_table[sk->sk_protocol].listeners);
+ nl_table[sk->sk_protocol].module = NULL;
+ nl_table[sk->sk_protocol].registered = 0;
+ }
+ } else if (nlk->subscriptions)
+ netlink_update_listeners(sk);
+ netlink_table_ungrab();
+
+ kfree(nlk->groups);
+ nlk->groups = NULL;
+
+ sock_put(sk);
+ return 0;
+}
+
+static int netlink_autobind(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct net *net = sock_net(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->tgid;
+ 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 (!net_eq(sock_net(osk), net))
+ continue;
+ 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, net, pid);
+ if (err == -EADDRINUSE)
+ goto retry;
+
+ /* If 2 threads race to autobind, that is fine. */
+ if (err == -EBUSY)
+ err = 0;
+
+ return err;
+}
+
+static inline int netlink_capable(struct socket *sock, unsigned int flag)
+{
+ return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) ||
+ capable(CAP_NET_ADMIN);
+}
+
+static void
+netlink_update_subscriptions(struct sock *sk, unsigned int subscriptions)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ if (nlk->subscriptions && !subscriptions)
+ __sk_del_bind_node(sk);
+ else if (!nlk->subscriptions && subscriptions)
+ sk_add_bind_node(sk, &nl_table[sk->sk_protocol].mc_list);
+ nlk->subscriptions = subscriptions;
+}
+
+static int netlink_realloc_groups(struct sock *sk)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+ unsigned int groups;
+ unsigned long *new_groups;
+ int err = 0;
+
+ netlink_table_grab();
+
+ groups = nl_table[sk->sk_protocol].groups;
+ if (!nl_table[sk->sk_protocol].registered) {
+ err = -ENOENT;
+ goto out_unlock;
+ }
+
+ if (nlk->ngroups >= groups)
+ goto out_unlock;
+
+ new_groups = krealloc(nlk->groups, NLGRPSZ(groups), GFP_ATOMIC);
+ if (new_groups == NULL) {
+ err = -ENOMEM;
+ goto out_unlock;
+ }
+ memset((char *)new_groups + NLGRPSZ(nlk->ngroups), 0,
+ NLGRPSZ(groups) - NLGRPSZ(nlk->ngroups));
+
+ nlk->groups = new_groups;
+ nlk->ngroups = groups;
+ out_unlock:
+ netlink_table_ungrab();
+ return err;
+}
+
+static int netlink_bind(struct socket *sock, struct sockaddr *addr,
+ int addr_len)
+{
+ struct sock *sk = sock->sk;
+ struct net *net = sock_net(sk);
+ struct netlink_sock *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) {
+ if (!netlink_capable(sock, NL_NONROOT_RECV))
+ return -EPERM;
+ err = netlink_realloc_groups(sk);
+ if (err)
+ return err;
+ }
+
+ if (nlk->pid) {
+ if (nladdr->nl_pid != nlk->pid)
+ return -EINVAL;
+ } else {
+ err = nladdr->nl_pid ?
+ netlink_insert(sk, net, nladdr->nl_pid) :
+ netlink_autobind(sock);
+ if (err)
+ return err;
+ }
+
+ if (!nladdr->nl_groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
+ return 0;
+
+ netlink_table_grab();
+ netlink_update_subscriptions(sk, nlk->subscriptions +
+ hweight32(nladdr->nl_groups) -
+ hweight32(nlk->groups[0]));
+ nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | nladdr->nl_groups;
+ netlink_update_listeners(sk);
+ 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_sock *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_group = 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_group = ffs(nladdr->nl_groups);
+ }
+
+ return err;
+}
+
+static int netlink_getname(struct socket *sock, struct sockaddr *addr,
+ int *addr_len, int peer)
+{
+ struct sock *sk = sock->sk;
+ struct netlink_sock *nlk = nlk_sk(sk);
+ struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
+
+ nladdr->nl_family = AF_NETLINK;
+ nladdr->nl_pad = 0;
+ *addr_len = sizeof(*nladdr);
+
+ if (peer) {
+ nladdr->nl_pid = nlk->dst_pid;
+ nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
+ } else {
+ nladdr->nl_pid = nlk->pid;
+ nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
+ }
+ return 0;
+}
+
+static void netlink_overrun(struct sock *sk)
+{
+ if (!test_and_set_bit(0, &nlk_sk(sk)->state)) {
+ sk->sk_err = ENOBUFS;
+ sk->sk_error_report(sk);
+ }
+}
+
+static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid)
+{
+ struct sock *sock;
+ struct netlink_sock *nlk;
+
+ sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, pid);
+ if (!sock)
+ return ERR_PTR(-ECONNREFUSED);
+
+ /* Don't bother queuing skb if kernel socket has no input function */
+ nlk = nlk_sk(sock);
+ if (sock->sk_state == NETLINK_CONNECTED &&
+ nlk->dst_pid != nlk_sk(ssk)->pid) {
+ sock_put(sock);
+ return ERR_PTR(-ECONNREFUSED);
+ }
+ return sock;
+}
+
+struct sock *netlink_getsockbyfilp(struct file *filp)
+{
+ struct inode *inode = filp->f_path.dentry->d_inode;
+ struct sock *sock;
+
+ if (!S_ISSOCK(inode->i_mode))
+ return ERR_PTR(-ENOTSOCK);
+
+ sock = SOCKET_I(inode)->sk;
+ if (sock->sk_family != AF_NETLINK)
+ return ERR_PTR(-EINVAL);
+
+ sock_hold(sock);
+ return sock;
+}
+
+/*
+ * Attach a skb to a netlink socket.
+ * The caller must hold a reference to the destination socket. On error, the
+ * reference is dropped. The skb is not send to the destination, just all
+ * all error checks are performed and memory in the queue is reserved.
+ * Return values:
+ * < 0: error. skb freed, reference to sock dropped.
+ * 0: continue
+ * 1: repeat lookup - reference dropped while waiting for socket memory.
+ */
+int netlink_attachskb(struct sock *sk, struct sk_buff *skb,
+ long *timeo, struct sock *ssk)
+{
+ struct netlink_sock *nlk;
+
+ nlk = nlk_sk(sk);
+
+ if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
+ test_bit(0, &nlk->state)) {
+ DECLARE_WAITQUEUE(wait, current);
+ if (!*timeo) {
+ if (!ssk || netlink_is_kernel(ssk))
+ netlink_overrun(sk);
+ sock_put(sk);
+ kfree_skb(skb);
+ return -EAGAIN;
+ }
+
+ __set_current_state(TASK_INTERRUPTIBLE);
+ add_wait_queue(&nlk->wait, &wait);
+
+ if ((atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf ||
+ test_bit(0, &nlk->state)) &&
+ !sock_flag(sk, SOCK_DEAD))
+ *timeo = schedule_timeout(*timeo);
+
+ __set_current_state(TASK_RUNNING);
+ remove_wait_queue(&nlk->wait, &wait);
+ sock_put(sk);
+
+ if (signal_pending(current)) {
+ kfree_skb(skb);
+ return sock_intr_errno(*timeo);
+ }
+ return 1;
+ }
+ skb_set_owner_r(skb, sk);
+ return 0;
+}
+
+int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
+{
+ int len = skb->len;
+
+ skb_queue_tail(&sk->sk_receive_queue, skb);
+ sk->sk_data_ready(sk, len);
+ sock_put(sk);
+ return len;
+}
+
+void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
+{
+ kfree_skb(skb);
+ sock_put(sk);
+}
+
+static inline struct sk_buff *netlink_trim(struct sk_buff *skb,
+ gfp_t allocation)
+{
+ int delta;
+
+ skb_orphan(skb);
+
+ delta = skb->end - skb->tail;
+ if (delta * 2 < skb->truesize)
+ return skb;
+
+ if (skb_shared(skb)) {
+ struct sk_buff *nskb = skb_clone(skb, allocation);
+ if (!nskb)
+ return skb;
+ kfree_skb(skb);
+ skb = nskb;
+ }
+
+ if (!pskb_expand_head(skb, 0, -delta, allocation))
+ skb->truesize -= delta;
+
+ return skb;
+}
+
+static inline void netlink_rcv_wake(struct sock *sk)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ if (skb_queue_empty(&sk->sk_receive_queue))
+ clear_bit(0, &nlk->state);
+ if (!test_bit(0, &nlk->state))
+ wake_up_interruptible(&nlk->wait);
+}
+
+static inline int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb)
+{
+ int ret;
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ ret = -ECONNREFUSED;
+ if (nlk->netlink_rcv != NULL) {
+ ret = skb->len;
+ skb_set_owner_r(skb, sk);
+ nlk->netlink_rcv(skb);
+ }
+ kfree_skb(skb);
+ sock_put(sk);
+ return ret;
+}
+
+int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
+ u32 pid, int nonblock)
+{
+ struct sock *sk;
+ int err;
+ long timeo;
+
+ skb = netlink_trim(skb, gfp_any());
+
+ timeo = sock_sndtimeo(ssk, nonblock);
+retry:
+ sk = netlink_getsockbypid(ssk, pid);
+ if (IS_ERR(sk)) {
+ kfree_skb(skb);
+ return PTR_ERR(sk);
+ }
+ if (netlink_is_kernel(sk))
+ return netlink_unicast_kernel(sk, skb);
+
+ if (sk_filter(sk, skb)) {
+ err = skb->len;
+ kfree_skb(skb);
+ sock_put(sk);
+ return err;
+ }
+
+ err = netlink_attachskb(sk, skb, &timeo, ssk);
+ if (err == 1)
+ goto retry;
+ if (err)
+ return err;
+
+ return netlink_sendskb(sk, skb);
+}
+EXPORT_SYMBOL(netlink_unicast);
+
+int netlink_has_listeners(struct sock *sk, unsigned int group)
+{
+ int res = 0;
+ unsigned long *listeners;
+
+ BUG_ON(!netlink_is_kernel(sk));
+
+ rcu_read_lock();
+ listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
+
+ if (group - 1 < nl_table[sk->sk_protocol].groups)
+ res = test_bit(group - 1, listeners);
+
+ rcu_read_unlock();
+
+ return res;
+}
+EXPORT_SYMBOL_GPL(netlink_has_listeners);
+
+static inline int netlink_broadcast_deliver(struct sock *sk,
+ struct sk_buff *skb)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ if (atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf &&
+ !test_bit(0, &nlk->state)) {
+ skb_set_owner_r(skb, sk);
+ skb_queue_tail(&sk->sk_receive_queue, skb);
+ sk->sk_data_ready(sk, skb->len);
+ return atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf;
+ }
+ return -1;
+}
+
+struct netlink_broadcast_data {
+ struct sock *exclude_sk;
+ struct net *net;
+ u32 pid;
+ u32 group;
+ int failure;
+ int congested;
+ int delivered;
+ gfp_t allocation;
+ struct sk_buff *skb, *skb2;
+};
+
+static inline int do_one_broadcast(struct sock *sk,
+ struct netlink_broadcast_data *p)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+ int val;
+
+ if (p->exclude_sk == sk)
+ goto out;
+
+ if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
+ !test_bit(p->group - 1, nlk->groups))
+ goto out;
+
+ if (!net_eq(sock_net(sk), p->net))
+ goto out;
+
+ if (p->failure) {
+ netlink_overrun(sk);
+ goto out;
+ }
+
+ sock_hold(sk);
+ if (p->skb2 == NULL) {
+ if (skb_shared(p->skb)) {
+ p->skb2 = skb_clone(p->skb, p->allocation);
+ } else {
+ p->skb2 = skb_get(p->skb);
+ /*
+ * skb ownership may have been set when
+ * delivered to a previous socket.
+ */
+ skb_orphan(p->skb2);
+ }
+ }
+ if (p->skb2 == NULL) {
+ netlink_overrun(sk);
+ /* Clone failed. Notify ALL listeners. */
+ p->failure = 1;
+ } else if (sk_filter(sk, p->skb2)) {
+ kfree_skb(p->skb2);
+ p->skb2 = NULL;
+ } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
+ netlink_overrun(sk);
+ } else {
+ p->congested |= val;
+ p->delivered = 1;
+ p->skb2 = NULL;
+ }
+ sock_put(sk);
+
+out:
+ return 0;
+}
+
+int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
+ u32 group, gfp_t allocation)
+{
+ struct net *net = sock_net(ssk);
+ struct netlink_broadcast_data info;
+ struct hlist_node *node;
+ struct sock *sk;
+
+ skb = netlink_trim(skb, allocation);
+
+ info.exclude_sk = ssk;
+ info.net = net;
+ info.pid = pid;
+ info.group = group;
+ info.failure = 0;
+ info.congested = 0;
+ info.delivered = 0;
+ info.allocation = allocation;
+ info.skb = skb;
+ info.skb2 = NULL;
+
+ /* While we sleep in clone, do not allow to change socket list */
+
+ netlink_lock_table();
+
+ sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
+ do_one_broadcast(sk, &info);
+
+ kfree_skb(skb);
+
+ netlink_unlock_table();
+
+ if (info.skb2)
+ kfree_skb(info.skb2);
+
+ if (info.delivered) {
+ if (info.congested && (allocation & __GFP_WAIT))
+ yield();
+ return 0;
+ }
+ if (info.failure)
+ return -ENOBUFS;
+ return -ESRCH;
+}
+EXPORT_SYMBOL(netlink_broadcast);
+
+struct netlink_set_err_data {
+ struct sock *exclude_sk;
+ u32 pid;
+ u32 group;
+ int code;
+};
+
+static inline int do_one_set_err(struct sock *sk,
+ struct netlink_set_err_data *p)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ if (sk == p->exclude_sk)
+ goto out;
+
+ if (sock_net(sk) != sock_net(p->exclude_sk))
+ goto out;
+
+ if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
+ !test_bit(p->group - 1, nlk->groups))
+ goto out;
+
+ sk->sk_err = p->code;
+ sk->sk_error_report(sk);
+out:
+ return 0;
+}
+
+void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)
+{
+ struct netlink_set_err_data info;
+ struct hlist_node *node;
+ struct sock *sk;
+
+ info.exclude_sk = ssk;
+ info.pid = pid;
+ info.group = group;
+ info.code = code;
+
+ read_lock(&nl_table_lock);
+
+ sk_for_each_bound(sk, node, &nl_table[ssk->sk_protocol].mc_list)
+ do_one_set_err(sk, &info);
+
+ read_unlock(&nl_table_lock);
+}
+
+/* must be called with netlink table grabbed */
+static void netlink_update_socket_mc(struct netlink_sock *nlk,
+ unsigned int group,
+ int is_new)
+{
+ int old, new = !!is_new, subscriptions;
+
+ old = test_bit(group - 1, nlk->groups);
+ subscriptions = nlk->subscriptions - old + new;
+ if (new)
+ __set_bit(group - 1, nlk->groups);
+ else
+ __clear_bit(group - 1, nlk->groups);
+ netlink_update_subscriptions(&nlk->sk, subscriptions);
+ netlink_update_listeners(&nlk->sk);
+}
+
+static int netlink_setsockopt(struct socket *sock, int level, int optname,
+ char __user *optval, int optlen)
+{
+ struct sock *sk = sock->sk;
+ struct netlink_sock *nlk = nlk_sk(sk);
+ unsigned int val = 0;
+ int err;
+
+ if (level != SOL_NETLINK)
+ return -ENOPROTOOPT;
+
+ if (optlen >= sizeof(int) &&
+ get_user(val, (unsigned int __user *)optval))
+ return -EFAULT;
+
+ switch (optname) {
+ case NETLINK_PKTINFO:
+ if (val)
+ nlk->flags |= NETLINK_RECV_PKTINFO;
+ else
+ nlk->flags &= ~NETLINK_RECV_PKTINFO;
+ err = 0;
+ break;
+ case NETLINK_ADD_MEMBERSHIP:
+ case NETLINK_DROP_MEMBERSHIP: {
+ if (!netlink_capable(sock, NL_NONROOT_RECV))
+ return -EPERM;
+ err = netlink_realloc_groups(sk);
+ if (err)
+ return err;
+ if (!val || val - 1 >= nlk->ngroups)
+ return -EINVAL;
+ netlink_table_grab();
+ netlink_update_socket_mc(nlk, val,
+ optname == NETLINK_ADD_MEMBERSHIP);
+ netlink_table_ungrab();
+ err = 0;
+ break;
+ }
+ default:
+ err = -ENOPROTOOPT;
+ }
+ return err;
+}
+
+static int netlink_getsockopt(struct socket *sock, int level, int optname,
+ char __user *optval, int __user *optlen)
+{
+ struct sock *sk = sock->sk;
+ struct netlink_sock *nlk = nlk_sk(sk);
+ int len, val, err;
+
+ if (level != SOL_NETLINK)
+ return -ENOPROTOOPT;
+
+ if (get_user(len, optlen))
+ return -EFAULT;
+ if (len < 0)
+ return -EINVAL;
+
+ switch (optname) {
+ case NETLINK_PKTINFO:
+ if (len < sizeof(int))
+ return -EINVAL;
+ len = sizeof(int);
+ val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
+ if (put_user(len, optlen) ||
+ put_user(val, optval))
+ return -EFAULT;
+ err = 0;
+ break;
+ default:
+ err = -ENOPROTOOPT;
+ }
+ return err;
+}
+
+static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
+{
+ struct nl_pktinfo info;
+
+ info.group = NETLINK_CB(skb).dst_group;
+ put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
+}
+
+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_sock *nlk = nlk_sk(sk);
+ struct sockaddr_nl *addr = msg->msg_name;
+ u32 dst_pid;
+ u32 dst_group;
+ 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_group = ffs(addr->nl_groups);
+ if (dst_group && !netlink_capable(sock, NL_NONROOT_SEND))
+ return -EPERM;
+ } else {
+ dst_pid = nlk->dst_pid;
+ dst_group = nlk->dst_group;
+ }
+
+ 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).dst_group = dst_group;
+ NETLINK_CB(skb).loginuid = audit_get_loginuid(current);
+ NETLINK_CB(skb).sessionid = audit_get_sessionid(current);
+ security_task_getsecid(current, &(NETLINK_CB(skb).sid));
+ 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_group) {
+ atomic_inc(&skb->users);
+ netlink_broadcast(sk, skb, dst_pid, dst_group, GFP_KERNEL);
+ }
+ err = netlink_unicast(sk, skb, dst_pid, msg->msg_flags&MSG_DONTWAIT);
+
+out:
+ return err;
+}
+
+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_sock *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_reset_transport_header(skb);
+ 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_group_mask(NETLINK_CB(skb).dst_group);
+ msg->msg_namelen = sizeof(*addr);
+ }
+
+ if (nlk->flags & NETLINK_RECV_PKTINFO)
+ netlink_cmsg_recv_pktinfo(msg, skb);
+
+ if (NULL == siocb->scm) {
+ memset(&scm, 0, sizeof(scm));
+ siocb->scm = &scm;
+ }
+ siocb->scm->creds = *NETLINK_CREDS(skb);
+ if (flags & MSG_TRUNC)
+ copied = skb->len;
+ 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 void netlink_data_ready(struct sock *sk, int len)
+{
+ BUG();
+}
+
+/*
+ * We export these functions to other modules. They provide a
+ * complete set of kernel non-blocking support for message
+ * queueing.
+ */
+
+struct sock *
+netlink_kernel_create(struct net *net, int unit, unsigned int groups,
+ void (*input)(struct sk_buff *skb),
+ struct mutex *cb_mutex, struct module *module)
+{
+ struct socket *sock;
+ struct sock *sk;
+ struct netlink_sock *nlk;
+ unsigned long *listeners = NULL;
+
+ BUG_ON(!nl_table);
+
+ if (unit < 0 || unit >= MAX_LINKS)
+ return NULL;
+
+ if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
+ return NULL;
+
+ /*
+ * We have to just have a reference on the net from sk, but don't
+ * get_net it. Besides, we cannot get and then put the net here.
+ * So we create one inside init_net and the move it to net.
+ */
+
+ if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0)
+ goto out_sock_release_nosk;
+
+ sk = sock->sk;
+ sk_change_net(sk, net);
+
+ if (groups < 32)
+ groups = 32;
+
+ listeners = kzalloc(NLGRPSZ(groups), GFP_KERNEL);
+ if (!listeners)
+ goto out_sock_release;
+
+ sk->sk_data_ready = netlink_data_ready;
+ if (input)
+ nlk_sk(sk)->netlink_rcv = input;
+
+ if (netlink_insert(sk, net, 0))
+ goto out_sock_release;
+
+ nlk = nlk_sk(sk);
+ nlk->flags |= NETLINK_KERNEL_SOCKET;
+
+ netlink_table_grab();
+ if (!nl_table[unit].registered) {
+ nl_table[unit].groups = groups;
+ nl_table[unit].listeners = listeners;
+ nl_table[unit].cb_mutex = cb_mutex;
+ nl_table[unit].module = module;
+ nl_table[unit].registered = 1;
+ } else {
+ kfree(listeners);
+ nl_table[unit].registered++;
+ }
+ netlink_table_ungrab();
+ return sk;
+
+out_sock_release:
+ kfree(listeners);
+ netlink_kernel_release(sk);
+ return NULL;
+
+out_sock_release_nosk:
+ sock_release(sock);
+ return NULL;
+}
+EXPORT_SYMBOL(netlink_kernel_create);
+
+
+void
+netlink_kernel_release(struct sock *sk)
+{
+ sk_release_kernel(sk);
+}
+EXPORT_SYMBOL(netlink_kernel_release);
+
+
+/**
+ * netlink_change_ngroups - change number of multicast groups
+ *
+ * This changes the number of multicast groups that are available
+ * on a certain netlink family. Note that it is not possible to
+ * change the number of groups to below 32. Also note that it does
+ * not implicitly call netlink_clear_multicast_users() when the
+ * number of groups is reduced.
+ *
+ * @sk: The kernel netlink socket, as returned by netlink_kernel_create().
+ * @groups: The new number of groups.
+ */
+int netlink_change_ngroups(struct sock *sk, unsigned int groups)
+{
+ unsigned long *listeners, *old = NULL;
+ struct netlink_table *tbl = &nl_table[sk->sk_protocol];
+ int err = 0;
+
+ if (groups < 32)
+ groups = 32;
+
+ netlink_table_grab();
+ if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
+ listeners = kzalloc(NLGRPSZ(groups), GFP_ATOMIC);
+ if (!listeners) {
+ err = -ENOMEM;
+ goto out_ungrab;
+ }
+ old = tbl->listeners;
+ memcpy(listeners, old, NLGRPSZ(tbl->groups));
+ rcu_assign_pointer(tbl->listeners, listeners);
+ }
+ tbl->groups = groups;
+
+ out_ungrab:
+ netlink_table_ungrab();
+ synchronize_rcu();
+ kfree(old);
+ return err;
+}
+EXPORT_SYMBOL(netlink_change_ngroups);
+
+/**
+ * netlink_clear_multicast_users - kick off multicast listeners
+ *
+ * This function removes all listeners from the given group.
+ * @ksk: The kernel netlink socket, as returned by
+ * netlink_kernel_create().
+ * @group: The multicast group to clear.
+ */
+void netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
+{
+ struct sock *sk;
+ struct hlist_node *node;
+ struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
+
+ netlink_table_grab();
+
+ sk_for_each_bound(sk, node, &tbl->mc_list)
+ netlink_update_socket_mc(nlk_sk(sk), group, 0);
+
+ netlink_table_ungrab();
+}
+EXPORT_SYMBOL(netlink_clear_multicast_users);
+
+void netlink_set_nonroot(int protocol, unsigned int flags)
+{
+ if ((unsigned int)protocol < MAX_LINKS)
+ nl_table[protocol].nl_nonroot = flags;
+}
+EXPORT_SYMBOL(netlink_set_nonroot);
+
+static void netlink_destroy_callback(struct netlink_callback *cb)
+{
+ if (cb->skb)
+ kfree_skb(cb->skb);
+ kfree(cb);
+}
+
+/*
+ * It looks a bit ugly.
+ * It would be better to create kernel thread.
+ */
+
+static int netlink_dump(struct sock *sk)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+ struct netlink_callback *cb;
+ struct sk_buff *skb;
+ struct nlmsghdr *nlh;
+ int len, err = -ENOBUFS;
+
+ skb = sock_rmalloc(sk, NLMSG_GOODSIZE, 0, GFP_KERNEL);
+ if (!skb)
+ goto errout;
+
+ mutex_lock(nlk->cb_mutex);
+
+ cb = nlk->cb;
+ if (cb == NULL) {
+ err = -EINVAL;
+ goto errout_skb;
+ }
+
+ len = cb->dump(skb, cb);
+
+ if (len > 0) {
+ mutex_unlock(nlk->cb_mutex);
+
+ if (sk_filter(sk, skb))
+ kfree_skb(skb);
+ else {
+ skb_queue_tail(&sk->sk_receive_queue, skb);
+ sk->sk_data_ready(sk, skb->len);
+ }
+ return 0;
+ }
+
+ nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE, sizeof(len), NLM_F_MULTI);
+ if (!nlh)
+ goto errout_skb;
+
+ memcpy(nlmsg_data(nlh), &len, sizeof(len));
+
+ if (sk_filter(sk, skb))
+ kfree_skb(skb);
+ else {
+ skb_queue_tail(&sk->sk_receive_queue, skb);
+ sk->sk_data_ready(sk, skb->len);
+ }
+
+ if (cb->done)
+ cb->done(cb);
+ nlk->cb = NULL;
+ mutex_unlock(nlk->cb_mutex);
+
+ netlink_destroy_callback(cb);
+ return 0;
+
+errout_skb:
+ mutex_unlock(nlk->cb_mutex);
+ kfree_skb(skb);
+errout:
+ return err;
+}
+
+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_sock *nlk;
+
+ cb = kzalloc(sizeof(*cb), GFP_KERNEL);
+ if (cb == NULL)
+ return -ENOBUFS;
+
+ cb->dump = dump;
+ cb->done = done;
+ cb->nlh = nlh;
+ atomic_inc(&skb->users);
+ cb->skb = skb;
+
+ sk = netlink_lookup(sock_net(ssk), 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... */
+ mutex_lock(nlk->cb_mutex);
+ if (nlk->cb) {
+ mutex_unlock(nlk->cb_mutex);
+ netlink_destroy_callback(cb);
+ sock_put(sk);
+ return -EBUSY;
+ }
+ nlk->cb = cb;
+ mutex_unlock(nlk->cb_mutex);
+
+ netlink_dump(sk);
+ sock_put(sk);
+
+ /* We successfully started a dump, by returning -EINTR we
+ * signal not to send ACK even if it was requested.
+ */
+ return -EINTR;
+}
+EXPORT_SYMBOL(netlink_dump_start);
+
+void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err)
+{
+ struct sk_buff *skb;
+ struct nlmsghdr *rep;
+ struct nlmsgerr *errmsg;
+ size_t payload = sizeof(*errmsg);
+
+ /* error messages get the original request appened */
+ if (err)
+ payload += nlmsg_len(nlh);
+
+ skb = nlmsg_new(payload, GFP_KERNEL);
+ if (!skb) {
+ struct sock *sk;
+
+ sk = netlink_lookup(sock_net(in_skb->sk),
+ in_skb->sk->sk_protocol,
+ NETLINK_CB(in_skb).pid);
+ if (sk) {
+ sk->sk_err = ENOBUFS;
+ sk->sk_error_report(sk);
+ sock_put(sk);
+ }
+ return;
+ }
+
+ rep = __nlmsg_put(skb, NETLINK_CB(in_skb).pid, nlh->nlmsg_seq,
+ NLMSG_ERROR, sizeof(struct nlmsgerr), 0);
+ errmsg = nlmsg_data(rep);
+ errmsg->error = err;
+ memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh));
+ netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).pid, MSG_DONTWAIT);
+}
+EXPORT_SYMBOL(netlink_ack);
+
+int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
+ struct nlmsghdr *))
+{
+ struct nlmsghdr *nlh;
+ int err;
+
+ while (skb->len >= nlmsg_total_size(0)) {
+ int msglen;
+
+ nlh = nlmsg_hdr(skb);
+ err = 0;
+
+ if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
+ return 0;
+
+ /* Only requests are handled by the kernel */
+ if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
+ goto ack;
+
+ /* Skip control messages */
+ if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
+ goto ack;
+
+ err = cb(skb, nlh);
+ if (err == -EINTR)
+ goto skip;
+
+ack:
+ if (nlh->nlmsg_flags & NLM_F_ACK || err)
+ netlink_ack(skb, nlh, err);
+
+skip:
+ msglen = NLMSG_ALIGN(nlh->nlmsg_len);
+ if (msglen > skb->len)
+ msglen = skb->len;
+ skb_pull(skb, msglen);
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(netlink_rcv_skb);
+
+/**
+ * nlmsg_notify - send a notification netlink message
+ * @sk: netlink socket to use
+ * @skb: notification message
+ * @pid: destination netlink pid for reports or 0
+ * @group: destination multicast group or 0
+ * @report: 1 to report back, 0 to disable
+ * @flags: allocation flags
+ */
+int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid,
+ unsigned int group, int report, gfp_t flags)
+{
+ int err = 0;
+
+ if (group) {
+ int exclude_pid = 0;
+
+ if (report) {
+ atomic_inc(&skb->users);
+ exclude_pid = pid;
+ }
+
+ /* errors reported via destination sk->sk_err */
+ nlmsg_multicast(sk, skb, exclude_pid, group, flags);
+ }
+
+ if (report)
+ err = nlmsg_unicast(sk, skb, pid);
+
+ return err;
+}
+EXPORT_SYMBOL(nlmsg_notify);
+
+#ifdef CONFIG_PROC_FS
+struct nl_seq_iter {
+ struct seq_net_private p;
+ int link;
+ int hash_idx;
+};
+
+static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
+{
+ struct nl_seq_iter *iter = seq->private;
+ int i, j;
+ struct sock *s;
+ struct hlist_node *node;
+ loff_t off = 0;
+
+ for (i = 0; i < MAX_LINKS; i++) {
+ struct nl_pid_hash *hash = &nl_table[i].hash;
+
+ for (j = 0; j <= hash->mask; j++) {
+ sk_for_each(s, node, &hash->table[j]) {
+ if (sock_net(s) != seq_file_net(seq))
+ continue;
+ if (off == pos) {
+ iter->link = i;
+ iter->hash_idx = j;
+ return s;
+ }
+ ++off;
+ }
+ }
+ }
+ return NULL;
+}
+
+static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
+ __acquires(nl_table_lock)
+{
+ read_lock(&nl_table_lock);
+ return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+}
+
+static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct sock *s;
+ struct nl_seq_iter *iter;
+ int i, j;
+
+ ++*pos;
+
+ if (v == SEQ_START_TOKEN)
+ return netlink_seq_socket_idx(seq, 0);
+
+ iter = seq->private;
+ s = v;
+ do {
+ s = sk_next(s);
+ } while (s && sock_net(s) != seq_file_net(seq));
+ if (s)
+ return s;
+
+ i = iter->link;
+ j = iter->hash_idx + 1;
+
+ do {
+ struct nl_pid_hash *hash = &nl_table[i].hash;
+
+ for (; j <= hash->mask; j++) {
+ s = sk_head(&hash->table[j]);
+ while (s && sock_net(s) != seq_file_net(seq))
+ s = sk_next(s);
+ if (s) {
+ iter->link = i;
+ iter->hash_idx = j;
+ return s;
+ }
+ }
+
+ j = 0;
+ } while (++i < MAX_LINKS);
+
+ return NULL;
+}
+
+static void netlink_seq_stop(struct seq_file *seq, void *v)
+ __releases(nl_table_lock)
+{
+ read_unlock(&nl_table_lock);
+}
+
+
+static int netlink_seq_show(struct seq_file *seq, void *v)
+{
+ if (v == SEQ_START_TOKEN)
+ seq_puts(seq,
+ "sk Eth Pid Groups "
+ "Rmem Wmem Dump Locks\n");
+ else {
+ struct sock *s = v;
+ struct netlink_sock *nlk = nlk_sk(s);
+
+ seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %d\n",
+ s,
+ s->sk_protocol,
+ nlk->pid,
+ nlk->groups ? (u32)nlk->groups[0] : 0,
+ atomic_read(&s->sk_rmem_alloc),
+ atomic_read(&s->sk_wmem_alloc),
+ nlk->cb,
+ atomic_read(&s->sk_refcnt)
+ );
+
+ }
+ return 0;
+}
+
+static const struct seq_operations netlink_seq_ops = {
+ .start = netlink_seq_start,
+ .next = netlink_seq_next,
+ .stop = netlink_seq_stop,
+ .show = netlink_seq_show,
+};
+
+
+static int netlink_seq_open(struct inode *inode, struct file *file)
+{
+ return seq_open_net(inode, file, &netlink_seq_ops,
+ sizeof(struct nl_seq_iter));
+}
+
+static const struct file_operations netlink_seq_fops = {
+ .owner = THIS_MODULE,
+ .open = netlink_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release_net,
+};
+
+#endif
+
+int netlink_register_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_register(&netlink_chain, nb);
+}
+EXPORT_SYMBOL(netlink_register_notifier);
+
+int netlink_unregister_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_unregister(&netlink_chain, nb);
+}
+EXPORT_SYMBOL(netlink_unregister_notifier);
+
+static const struct proto_ops netlink_ops = {
+ .family = PF_NETLINK,
+ .owner = THIS_MODULE,
+ .release = netlink_release,
+ .bind = netlink_bind,
+ .connect = netlink_connect,
+ .socketpair = sock_no_socketpair,
+ .accept = sock_no_accept,
+ .getname = netlink_getname,
+ .poll = datagram_poll,
+ .ioctl = sock_no_ioctl,
+ .listen = sock_no_listen,
+ .shutdown = sock_no_shutdown,
+ .setsockopt = netlink_setsockopt,
+ .getsockopt = netlink_getsockopt,
+ .sendmsg = netlink_sendmsg,
+ .recvmsg = netlink_recvmsg,
+ .mmap = sock_no_mmap,
+ .sendpage = sock_no_sendpage,
+};
+
+static struct net_proto_family netlink_family_ops = {
+ .family = PF_NETLINK,
+ .create = netlink_create,
+ .owner = THIS_MODULE, /* for consistency 8) */
+};
+
+static int __net_init netlink_net_init(struct net *net)
+{
+#ifdef CONFIG_PROC_FS
+ if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops))
+ return -ENOMEM;
+#endif
+ return 0;
+}
+
+static void __net_exit netlink_net_exit(struct net *net)
+{
+#ifdef CONFIG_PROC_FS
+ proc_net_remove(net, "netlink");
+#endif
+}
+
+static struct pernet_operations __net_initdata netlink_net_ops = {
+ .init = netlink_net_init,
+ .exit = netlink_net_exit,
+};
+
+static int __init netlink_proto_init(void)
+{
+ struct sk_buff *dummy_skb;
+ int i;
+ unsigned long limit;
+ unsigned int order;
+ int err = proto_register(&netlink_proto, 0);
+
+ if (err != 0)
+ goto out;
+
+ BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > sizeof(dummy_skb->cb));
+
+ nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
+ if (!nl_table)
+ goto panic;
+
+ if (num_physpages >= (128 * 1024))
+ limit = num_physpages >> (21 - PAGE_SHIFT);
+ else
+ limit = num_physpages >> (23 - PAGE_SHIFT);
+
+ order = get_bitmask_order(limit) - 1 + PAGE_SHIFT;
+ limit = (1UL << order) / sizeof(struct hlist_head);
+ order = get_bitmask_order(min(limit, (unsigned long)UINT_MAX)) - 1;
+
+ for (i = 0; i < MAX_LINKS; i++) {
+ struct nl_pid_hash *hash = &nl_table[i].hash;
+
+ hash->table = nl_pid_hash_zalloc(1 * sizeof(*hash->table));
+ if (!hash->table) {
+ while (i-- > 0)
+ nl_pid_hash_free(nl_table[i].hash.table,
+ 1 * sizeof(*hash->table));
+ kfree(nl_table);
+ goto panic;
+ }
+ hash->max_shift = order;
+ hash->shift = 0;
+ hash->mask = 0;
+ hash->rehash_time = jiffies;
+ }
+
+ sock_register(&netlink_family_ops);
+ register_pernet_subsys(&netlink_net_ops);
+ /* The netlink device handler may be needed early. */
+ rtnetlink_init();
+out:
+ return err;
+panic:
+ panic("netlink_init: Cannot allocate nl_table\n");
+}
+
+core_initcall(netlink_proto_init);
diff --git a/net/netlink/attr.c b/net/netlink/attr.c
new file mode 100644
index 0000000..2d106cf
--- /dev/null
+++ b/net/netlink/attr.c
@@ -0,0 +1,467 @@
+/*
+ * NETLINK Netlink attributes
+ *
+ * Authors: Thomas Graf <tgraf@suug.ch>
+ * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/jiffies.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <net/netlink.h>
+
+static u16 nla_attr_minlen[NLA_TYPE_MAX+1] __read_mostly = {
+ [NLA_U8] = sizeof(u8),
+ [NLA_U16] = sizeof(u16),
+ [NLA_U32] = sizeof(u32),
+ [NLA_U64] = sizeof(u64),
+ [NLA_NESTED] = NLA_HDRLEN,
+};
+
+static int validate_nla(struct nlattr *nla, int maxtype,
+ const struct nla_policy *policy)
+{
+ const struct nla_policy *pt;
+ int minlen = 0, attrlen = nla_len(nla), type = nla_type(nla);
+
+ if (type <= 0 || type > maxtype)
+ return 0;
+
+ pt = &policy[type];
+
+ BUG_ON(pt->type > NLA_TYPE_MAX);
+
+ switch (pt->type) {
+ case NLA_FLAG:
+ if (attrlen > 0)
+ return -ERANGE;
+ break;
+
+ case NLA_NUL_STRING:
+ if (pt->len)
+ minlen = min_t(int, attrlen, pt->len + 1);
+ else
+ minlen = attrlen;
+
+ if (!minlen || memchr(nla_data(nla), '\0', minlen) == NULL)
+ return -EINVAL;
+ /* fall through */
+
+ case NLA_STRING:
+ if (attrlen < 1)
+ return -ERANGE;
+
+ if (pt->len) {
+ char *buf = nla_data(nla);
+
+ if (buf[attrlen - 1] == '\0')
+ attrlen--;
+
+ if (attrlen > pt->len)
+ return -ERANGE;
+ }
+ break;
+
+ case NLA_BINARY:
+ if (pt->len && attrlen > pt->len)
+ return -ERANGE;
+ break;
+
+ case NLA_NESTED_COMPAT:
+ if (attrlen < pt->len)
+ return -ERANGE;
+ if (attrlen < NLA_ALIGN(pt->len))
+ break;
+ if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN)
+ return -ERANGE;
+ nla = nla_data(nla) + NLA_ALIGN(pt->len);
+ if (attrlen < NLA_ALIGN(pt->len) + NLA_HDRLEN + nla_len(nla))
+ return -ERANGE;
+ break;
+ default:
+ if (pt->len)
+ minlen = pt->len;
+ else if (pt->type != NLA_UNSPEC)
+ minlen = nla_attr_minlen[pt->type];
+
+ if (attrlen < minlen)
+ return -ERANGE;
+ }
+
+ return 0;
+}
+
+/**
+ * nla_validate - Validate a stream of attributes
+ * @head: head of attribute stream
+ * @len: length of attribute stream
+ * @maxtype: maximum attribute type to be expected
+ * @policy: validation policy
+ *
+ * Validates all attributes in the specified attribute stream against the
+ * specified policy. Attributes with a type exceeding maxtype will be
+ * ignored. See documenation of struct nla_policy for more details.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int nla_validate(struct nlattr *head, int len, int maxtype,
+ const struct nla_policy *policy)
+{
+ struct nlattr *nla;
+ int rem, err;
+
+ nla_for_each_attr(nla, head, len, rem) {
+ err = validate_nla(nla, maxtype, policy);
+ if (err < 0)
+ goto errout;
+ }
+
+ err = 0;
+errout:
+ return err;
+}
+
+/**
+ * nla_parse - Parse a stream of attributes into a tb buffer
+ * @tb: destination array with maxtype+1 elements
+ * @maxtype: maximum attribute type to be expected
+ * @head: head of attribute stream
+ * @len: length of attribute stream
+ * @policy: validation policy
+ *
+ * Parses a stream of attributes and stores a pointer to each attribute in
+ * the tb array accessable via the attribute type. Attributes with a type
+ * exceeding maxtype will be silently ignored for backwards compatibility
+ * reasons. policy may be set to NULL if no validation is required.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int nla_parse(struct nlattr *tb[], int maxtype, struct nlattr *head, int len,
+ const struct nla_policy *policy)
+{
+ struct nlattr *nla;
+ int rem, err;
+
+ memset(tb, 0, sizeof(struct nlattr *) * (maxtype + 1));
+
+ nla_for_each_attr(nla, head, len, rem) {
+ u16 type = nla_type(nla);
+
+ if (type > 0 && type <= maxtype) {
+ if (policy) {
+ err = validate_nla(nla, maxtype, policy);
+ if (err < 0)
+ goto errout;
+ }
+
+ tb[type] = nla;
+ }
+ }
+
+ if (unlikely(rem > 0))
+ printk(KERN_WARNING "netlink: %d bytes leftover after parsing "
+ "attributes.\n", rem);
+
+ err = 0;
+errout:
+ return err;
+}
+
+/**
+ * nla_find - Find a specific attribute in a stream of attributes
+ * @head: head of attribute stream
+ * @len: length of attribute stream
+ * @attrtype: type of attribute to look for
+ *
+ * Returns the first attribute in the stream matching the specified type.
+ */
+struct nlattr *nla_find(struct nlattr *head, int len, int attrtype)
+{
+ struct nlattr *nla;
+ int rem;
+
+ nla_for_each_attr(nla, head, len, rem)
+ if (nla_type(nla) == attrtype)
+ return nla;
+
+ return NULL;
+}
+
+/**
+ * nla_strlcpy - Copy string attribute payload into a sized buffer
+ * @dst: where to copy the string to
+ * @nla: attribute to copy the string from
+ * @dstsize: size of destination buffer
+ *
+ * Copies at most dstsize - 1 bytes into the destination buffer.
+ * The result is always a valid NUL-terminated string. Unlike
+ * strlcpy the destination buffer is always padded out.
+ *
+ * Returns the length of the source buffer.
+ */
+size_t nla_strlcpy(char *dst, const struct nlattr *nla, size_t dstsize)
+{
+ size_t srclen = nla_len(nla);
+ char *src = nla_data(nla);
+
+ if (srclen > 0 && src[srclen - 1] == '\0')
+ srclen--;
+
+ if (dstsize > 0) {
+ size_t len = (srclen >= dstsize) ? dstsize - 1 : srclen;
+
+ memset(dst, 0, dstsize);
+ memcpy(dst, src, len);
+ }
+
+ return srclen;
+}
+
+/**
+ * nla_memcpy - Copy a netlink attribute into another memory area
+ * @dest: where to copy to memcpy
+ * @src: netlink attribute to copy from
+ * @count: size of the destination area
+ *
+ * Note: The number of bytes copied is limited by the length of
+ * attribute's payload. memcpy
+ *
+ * Returns the number of bytes copied.
+ */
+int nla_memcpy(void *dest, struct nlattr *src, int count)
+{
+ int minlen = min_t(int, count, nla_len(src));
+
+ memcpy(dest, nla_data(src), minlen);
+
+ return minlen;
+}
+
+/**
+ * nla_memcmp - Compare an attribute with sized memory area
+ * @nla: netlink attribute
+ * @data: memory area
+ * @size: size of memory area
+ */
+int nla_memcmp(const struct nlattr *nla, const void *data,
+ size_t size)
+{
+ int d = nla_len(nla) - size;
+
+ if (d == 0)
+ d = memcmp(nla_data(nla), data, size);
+
+ return d;
+}
+
+/**
+ * nla_strcmp - Compare a string attribute against a string
+ * @nla: netlink string attribute
+ * @str: another string
+ */
+int nla_strcmp(const struct nlattr *nla, const char *str)
+{
+ int len = strlen(str) + 1;
+ int d = nla_len(nla) - len;
+
+ if (d == 0)
+ d = memcmp(nla_data(nla), str, len);
+
+ return d;
+}
+
+/**
+ * __nla_reserve - reserve room for attribute on the skb
+ * @skb: socket buffer to reserve room on
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ *
+ * Adds a netlink attribute header to a socket buffer and reserves
+ * room for the payload but does not copy it.
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the attribute header and payload.
+ */
+struct nlattr *__nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
+{
+ struct nlattr *nla;
+
+ nla = (struct nlattr *) skb_put(skb, nla_total_size(attrlen));
+ nla->nla_type = attrtype;
+ nla->nla_len = nla_attr_size(attrlen);
+
+ memset((unsigned char *) nla + nla->nla_len, 0, nla_padlen(attrlen));
+
+ return nla;
+}
+
+/**
+ * __nla_reserve_nohdr - reserve room for attribute without header
+ * @skb: socket buffer to reserve room on
+ * @attrlen: length of attribute payload
+ *
+ * Reserves room for attribute payload without a header.
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the payload.
+ */
+void *__nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
+{
+ void *start;
+
+ start = skb_put(skb, NLA_ALIGN(attrlen));
+ memset(start, 0, NLA_ALIGN(attrlen));
+
+ return start;
+}
+
+/**
+ * nla_reserve - reserve room for attribute on the skb
+ * @skb: socket buffer to reserve room on
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ *
+ * Adds a netlink attribute header to a socket buffer and reserves
+ * room for the payload but does not copy it.
+ *
+ * Returns NULL if the tailroom of the skb is insufficient to store
+ * the attribute header and payload.
+ */
+struct nlattr *nla_reserve(struct sk_buff *skb, int attrtype, int attrlen)
+{
+ if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
+ return NULL;
+
+ return __nla_reserve(skb, attrtype, attrlen);
+}
+
+/**
+ * nla_reserve_nohdr - reserve room for attribute without header
+ * @skb: socket buffer to reserve room on
+ * @attrlen: length of attribute payload
+ *
+ * Reserves room for attribute payload without a header.
+ *
+ * Returns NULL if the tailroom of the skb is insufficient to store
+ * the attribute payload.
+ */
+void *nla_reserve_nohdr(struct sk_buff *skb, int attrlen)
+{
+ if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
+ return NULL;
+
+ return __nla_reserve_nohdr(skb, attrlen);
+}
+
+/**
+ * __nla_put - Add a netlink attribute to a socket buffer
+ * @skb: socket buffer to add attribute to
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the attribute header and payload.
+ */
+void __nla_put(struct sk_buff *skb, int attrtype, int attrlen,
+ const void *data)
+{
+ struct nlattr *nla;
+
+ nla = __nla_reserve(skb, attrtype, attrlen);
+ memcpy(nla_data(nla), data, attrlen);
+}
+
+/**
+ * __nla_put_nohdr - Add a netlink attribute without header
+ * @skb: socket buffer to add attribute to
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * The caller is responsible to ensure that the skb provides enough
+ * tailroom for the attribute payload.
+ */
+void __nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
+{
+ void *start;
+
+ start = __nla_reserve_nohdr(skb, attrlen);
+ memcpy(start, data, attrlen);
+}
+
+/**
+ * nla_put - Add a netlink attribute to a socket buffer
+ * @skb: socket buffer to add attribute to
+ * @attrtype: attribute type
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
+ * the attribute header and payload.
+ */
+int nla_put(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
+{
+ if (unlikely(skb_tailroom(skb) < nla_total_size(attrlen)))
+ return -EMSGSIZE;
+
+ __nla_put(skb, attrtype, attrlen, data);
+ return 0;
+}
+
+/**
+ * nla_put_nohdr - Add a netlink attribute without header
+ * @skb: socket buffer to add attribute to
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
+ * the attribute payload.
+ */
+int nla_put_nohdr(struct sk_buff *skb, int attrlen, const void *data)
+{
+ if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
+ return -EMSGSIZE;
+
+ __nla_put_nohdr(skb, attrlen, data);
+ return 0;
+}
+
+/**
+ * nla_append - Add a netlink attribute without header or padding
+ * @skb: socket buffer to add attribute to
+ * @attrlen: length of attribute payload
+ * @data: head of attribute payload
+ *
+ * Returns -EMSGSIZE if the tailroom of the skb is insufficient to store
+ * the attribute payload.
+ */
+int nla_append(struct sk_buff *skb, int attrlen, const void *data)
+{
+ if (unlikely(skb_tailroom(skb) < NLA_ALIGN(attrlen)))
+ return -EMSGSIZE;
+
+ memcpy(skb_put(skb, attrlen), data, attrlen);
+ return 0;
+}
+
+EXPORT_SYMBOL(nla_validate);
+EXPORT_SYMBOL(nla_parse);
+EXPORT_SYMBOL(nla_find);
+EXPORT_SYMBOL(nla_strlcpy);
+EXPORT_SYMBOL(__nla_reserve);
+EXPORT_SYMBOL(__nla_reserve_nohdr);
+EXPORT_SYMBOL(nla_reserve);
+EXPORT_SYMBOL(nla_reserve_nohdr);
+EXPORT_SYMBOL(__nla_put);
+EXPORT_SYMBOL(__nla_put_nohdr);
+EXPORT_SYMBOL(nla_put);
+EXPORT_SYMBOL(nla_put_nohdr);
+EXPORT_SYMBOL(nla_memcpy);
+EXPORT_SYMBOL(nla_memcmp);
+EXPORT_SYMBOL(nla_strcmp);
+EXPORT_SYMBOL(nla_append);
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
new file mode 100644
index 0000000..3e1191c
--- /dev/null
+++ b/net/netlink/genetlink.c
@@ -0,0 +1,792 @@
+/*
+ * NETLINK Generic Netlink Family
+ *
+ * Authors: Jamal Hadi Salim
+ * Thomas Graf <tgraf@suug.ch>
+ * Johannes Berg <johannes@sipsolutions.net>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/string.h>
+#include <linux/skbuff.h>
+#include <linux/mutex.h>
+#include <linux/bitmap.h>
+#include <net/sock.h>
+#include <net/genetlink.h>
+
+struct sock *genl_sock = NULL;
+
+static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
+
+static inline void genl_lock(void)
+{
+ mutex_lock(&genl_mutex);
+}
+
+static inline void genl_unlock(void)
+{
+ mutex_unlock(&genl_mutex);
+}
+
+#define GENL_FAM_TAB_SIZE 16
+#define GENL_FAM_TAB_MASK (GENL_FAM_TAB_SIZE - 1)
+
+static struct list_head family_ht[GENL_FAM_TAB_SIZE];
+/*
+ * Bitmap of multicast groups that are currently in use.
+ *
+ * To avoid an allocation at boot of just one unsigned long,
+ * declare it global instead.
+ * Bit 0 is marked as already used since group 0 is invalid.
+ */
+static unsigned long mc_group_start = 0x1;
+static unsigned long *mc_groups = &mc_group_start;
+static unsigned long mc_groups_longs = 1;
+
+static int genl_ctrl_event(int event, void *data);
+
+static inline unsigned int genl_family_hash(unsigned int id)
+{
+ return id & GENL_FAM_TAB_MASK;
+}
+
+static inline struct list_head *genl_family_chain(unsigned int id)
+{
+ return &family_ht[genl_family_hash(id)];
+}
+
+static struct genl_family *genl_family_find_byid(unsigned int id)
+{
+ struct genl_family *f;
+
+ list_for_each_entry(f, genl_family_chain(id), family_list)
+ if (f->id == id)
+ return f;
+
+ return NULL;
+}
+
+static struct genl_family *genl_family_find_byname(char *name)
+{
+ struct genl_family *f;
+ int i;
+
+ for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
+ list_for_each_entry(f, genl_family_chain(i), family_list)
+ if (strcmp(f->name, name) == 0)
+ return f;
+
+ return NULL;
+}
+
+static struct genl_ops *genl_get_cmd(u8 cmd, struct genl_family *family)
+{
+ struct genl_ops *ops;
+
+ list_for_each_entry(ops, &family->ops_list, ops_list)
+ if (ops->cmd == cmd)
+ return ops;
+
+ return NULL;
+}
+
+/* Of course we are going to have problems once we hit
+ * 2^16 alive types, but that can only happen by year 2K
+*/
+static inline u16 genl_generate_id(void)
+{
+ static u16 id_gen_idx;
+ int overflowed = 0;
+
+ do {
+ if (id_gen_idx == 0)
+ id_gen_idx = GENL_MIN_ID;
+
+ if (++id_gen_idx > GENL_MAX_ID) {
+ if (!overflowed) {
+ overflowed = 1;
+ id_gen_idx = 0;
+ continue;
+ } else
+ return 0;
+ }
+
+ } while (genl_family_find_byid(id_gen_idx));
+
+ return id_gen_idx;
+}
+
+static struct genl_multicast_group notify_grp;
+
+/**
+ * genl_register_mc_group - register a multicast group
+ *
+ * Registers the specified multicast group and notifies userspace
+ * about the new group.
+ *
+ * Returns 0 on success or a negative error code.
+ *
+ * @family: The generic netlink family the group shall be registered for.
+ * @grp: The group to register, must have a name.
+ */
+int genl_register_mc_group(struct genl_family *family,
+ struct genl_multicast_group *grp)
+{
+ int id;
+ unsigned long *new_groups;
+ int err;
+
+ BUG_ON(grp->name[0] == '\0');
+
+ genl_lock();
+
+ /* special-case our own group */
+ if (grp == &notify_grp)
+ id = GENL_ID_CTRL;
+ else
+ id = find_first_zero_bit(mc_groups,
+ mc_groups_longs * BITS_PER_LONG);
+
+
+ if (id >= mc_groups_longs * BITS_PER_LONG) {
+ size_t nlen = (mc_groups_longs + 1) * sizeof(unsigned long);
+
+ if (mc_groups == &mc_group_start) {
+ new_groups = kzalloc(nlen, GFP_KERNEL);
+ if (!new_groups) {
+ err = -ENOMEM;
+ goto out;
+ }
+ mc_groups = new_groups;
+ *mc_groups = mc_group_start;
+ } else {
+ new_groups = krealloc(mc_groups, nlen, GFP_KERNEL);
+ if (!new_groups) {
+ err = -ENOMEM;
+ goto out;
+ }
+ mc_groups = new_groups;
+ mc_groups[mc_groups_longs] = 0;
+ }
+ mc_groups_longs++;
+ }
+
+ err = netlink_change_ngroups(genl_sock,
+ mc_groups_longs * BITS_PER_LONG);
+ if (err)
+ goto out;
+
+ grp->id = id;
+ set_bit(id, mc_groups);
+ list_add_tail(&grp->list, &family->mcast_groups);
+ grp->family = family;
+
+ genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, grp);
+ out:
+ genl_unlock();
+ return err;
+}
+EXPORT_SYMBOL(genl_register_mc_group);
+
+static void __genl_unregister_mc_group(struct genl_family *family,
+ struct genl_multicast_group *grp)
+{
+ BUG_ON(grp->family != family);
+ netlink_clear_multicast_users(genl_sock, grp->id);
+ clear_bit(grp->id, mc_groups);
+ list_del(&grp->list);
+ genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, grp);
+ grp->id = 0;
+ grp->family = NULL;
+}
+
+/**
+ * genl_unregister_mc_group - unregister a multicast group
+ *
+ * Unregisters the specified multicast group and notifies userspace
+ * about it. All current listeners on the group are removed.
+ *
+ * Note: It is not necessary to unregister all multicast groups before
+ * unregistering the family, unregistering the family will cause
+ * all assigned multicast groups to be unregistered automatically.
+ *
+ * @family: Generic netlink family the group belongs to.
+ * @grp: The group to unregister, must have been registered successfully
+ * previously.
+ */
+void genl_unregister_mc_group(struct genl_family *family,
+ struct genl_multicast_group *grp)
+{
+ genl_lock();
+ __genl_unregister_mc_group(family, grp);
+ genl_unlock();
+}
+
+static void genl_unregister_mc_groups(struct genl_family *family)
+{
+ struct genl_multicast_group *grp, *tmp;
+
+ list_for_each_entry_safe(grp, tmp, &family->mcast_groups, list)
+ __genl_unregister_mc_group(family, grp);
+}
+
+/**
+ * genl_register_ops - register generic netlink operations
+ * @family: generic netlink family
+ * @ops: operations to be registered
+ *
+ * Registers the specified operations and assigns them to the specified
+ * family. Either a doit or dumpit callback must be specified or the
+ * operation will fail. Only one operation structure per command
+ * identifier may be registered.
+ *
+ * See include/net/genetlink.h for more documenation on the operations
+ * structure.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int genl_register_ops(struct genl_family *family, struct genl_ops *ops)
+{
+ int err = -EINVAL;
+
+ if (ops->dumpit == NULL && ops->doit == NULL)
+ goto errout;
+
+ if (genl_get_cmd(ops->cmd, family)) {
+ err = -EEXIST;
+ goto errout;
+ }
+
+ if (ops->dumpit)
+ ops->flags |= GENL_CMD_CAP_DUMP;
+ if (ops->doit)
+ ops->flags |= GENL_CMD_CAP_DO;
+ if (ops->policy)
+ ops->flags |= GENL_CMD_CAP_HASPOL;
+
+ genl_lock();
+ list_add_tail(&ops->ops_list, &family->ops_list);
+ genl_unlock();
+
+ genl_ctrl_event(CTRL_CMD_NEWOPS, ops);
+ err = 0;
+errout:
+ return err;
+}
+
+/**
+ * genl_unregister_ops - unregister generic netlink operations
+ * @family: generic netlink family
+ * @ops: operations to be unregistered
+ *
+ * Unregisters the specified operations and unassigns them from the
+ * specified family. The operation blocks until the current message
+ * processing has finished and doesn't start again until the
+ * unregister process has finished.
+ *
+ * Note: It is not necessary to unregister all operations before
+ * unregistering the family, unregistering the family will cause
+ * all assigned operations to be unregistered automatically.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int genl_unregister_ops(struct genl_family *family, struct genl_ops *ops)
+{
+ struct genl_ops *rc;
+
+ genl_lock();
+ list_for_each_entry(rc, &family->ops_list, ops_list) {
+ if (rc == ops) {
+ list_del(&ops->ops_list);
+ genl_unlock();
+ genl_ctrl_event(CTRL_CMD_DELOPS, ops);
+ return 0;
+ }
+ }
+ genl_unlock();
+
+ return -ENOENT;
+}
+
+/**
+ * genl_register_family - register a generic netlink family
+ * @family: generic netlink family
+ *
+ * Registers the specified family after validating it first. Only one
+ * family may be registered with the same family name or identifier.
+ * The family id may equal GENL_ID_GENERATE causing an unique id to
+ * be automatically generated and assigned.
+ *
+ * Return 0 on success or a negative error code.
+ */
+int genl_register_family(struct genl_family *family)
+{
+ int err = -EINVAL;
+
+ if (family->id && family->id < GENL_MIN_ID)
+ goto errout;
+
+ if (family->id > GENL_MAX_ID)
+ goto errout;
+
+ INIT_LIST_HEAD(&family->ops_list);
+ INIT_LIST_HEAD(&family->mcast_groups);
+
+ genl_lock();
+
+ if (genl_family_find_byname(family->name)) {
+ err = -EEXIST;
+ goto errout_locked;
+ }
+
+ if (genl_family_find_byid(family->id)) {
+ err = -EEXIST;
+ goto errout_locked;
+ }
+
+ if (family->id == GENL_ID_GENERATE) {
+ u16 newid = genl_generate_id();
+
+ if (!newid) {
+ err = -ENOMEM;
+ goto errout_locked;
+ }
+
+ family->id = newid;
+ }
+
+ if (family->maxattr) {
+ family->attrbuf = kmalloc((family->maxattr+1) *
+ sizeof(struct nlattr *), GFP_KERNEL);
+ if (family->attrbuf == NULL) {
+ err = -ENOMEM;
+ goto errout_locked;
+ }
+ } else
+ family->attrbuf = NULL;
+
+ list_add_tail(&family->family_list, genl_family_chain(family->id));
+ genl_unlock();
+
+ genl_ctrl_event(CTRL_CMD_NEWFAMILY, family);
+
+ return 0;
+
+errout_locked:
+ genl_unlock();
+errout:
+ return err;
+}
+
+/**
+ * genl_unregister_family - unregister generic netlink family
+ * @family: generic netlink family
+ *
+ * Unregisters the specified family.
+ *
+ * Returns 0 on success or a negative error code.
+ */
+int genl_unregister_family(struct genl_family *family)
+{
+ struct genl_family *rc;
+
+ genl_lock();
+
+ genl_unregister_mc_groups(family);
+
+ list_for_each_entry(rc, genl_family_chain(family->id), family_list) {
+ if (family->id != rc->id || strcmp(rc->name, family->name))
+ continue;
+
+ list_del(&rc->family_list);
+ INIT_LIST_HEAD(&family->ops_list);
+ genl_unlock();
+
+ kfree(family->attrbuf);
+ genl_ctrl_event(CTRL_CMD_DELFAMILY, family);
+ return 0;
+ }
+
+ genl_unlock();
+
+ return -ENOENT;
+}
+
+static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+ struct genl_ops *ops;
+ struct genl_family *family;
+ struct genl_info info;
+ struct genlmsghdr *hdr = nlmsg_data(nlh);
+ int hdrlen, err;
+
+ family = genl_family_find_byid(nlh->nlmsg_type);
+ if (family == NULL)
+ return -ENOENT;
+
+ hdrlen = GENL_HDRLEN + family->hdrsize;
+ if (nlh->nlmsg_len < nlmsg_msg_size(hdrlen))
+ return -EINVAL;
+
+ ops = genl_get_cmd(hdr->cmd, family);
+ if (ops == NULL)
+ return -EOPNOTSUPP;
+
+ if ((ops->flags & GENL_ADMIN_PERM) &&
+ security_netlink_recv(skb, CAP_NET_ADMIN))
+ return -EPERM;
+
+ if (nlh->nlmsg_flags & NLM_F_DUMP) {
+ if (ops->dumpit == NULL)
+ return -EOPNOTSUPP;
+
+ genl_unlock();
+ err = netlink_dump_start(genl_sock, skb, nlh,
+ ops->dumpit, ops->done);
+ genl_lock();
+ return err;
+ }
+
+ if (ops->doit == NULL)
+ return -EOPNOTSUPP;
+
+ if (family->attrbuf) {
+ err = nlmsg_parse(nlh, hdrlen, family->attrbuf, family->maxattr,
+ ops->policy);
+ if (err < 0)
+ return err;
+ }
+
+ info.snd_seq = nlh->nlmsg_seq;
+ info.snd_pid = NETLINK_CB(skb).pid;
+ info.nlhdr = nlh;
+ info.genlhdr = nlmsg_data(nlh);
+ info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
+ info.attrs = family->attrbuf;
+
+ return ops->doit(skb, &info);
+}
+
+static void genl_rcv(struct sk_buff *skb)
+{
+ genl_lock();
+ netlink_rcv_skb(skb, &genl_rcv_msg);
+ genl_unlock();
+}
+
+/**************************************************************************
+ * Controller
+ **************************************************************************/
+
+static struct genl_family genl_ctrl = {
+ .id = GENL_ID_CTRL,
+ .name = "nlctrl",
+ .version = 0x2,
+ .maxattr = CTRL_ATTR_MAX,
+};
+
+static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq,
+ u32 flags, struct sk_buff *skb, u8 cmd)
+{
+ void *hdr;
+
+ hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
+ if (hdr == NULL)
+ return -1;
+
+ NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, family->name);
+ NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, family->id);
+ NLA_PUT_U32(skb, CTRL_ATTR_VERSION, family->version);
+ NLA_PUT_U32(skb, CTRL_ATTR_HDRSIZE, family->hdrsize);
+ NLA_PUT_U32(skb, CTRL_ATTR_MAXATTR, family->maxattr);
+
+ if (!list_empty(&family->ops_list)) {
+ struct nlattr *nla_ops;
+ struct genl_ops *ops;
+ int idx = 1;
+
+ nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
+ if (nla_ops == NULL)
+ goto nla_put_failure;
+
+ list_for_each_entry(ops, &family->ops_list, ops_list) {
+ struct nlattr *nest;
+
+ nest = nla_nest_start(skb, idx++);
+ if (nest == NULL)
+ goto nla_put_failure;
+
+ NLA_PUT_U32(skb, CTRL_ATTR_OP_ID, ops->cmd);
+ NLA_PUT_U32(skb, CTRL_ATTR_OP_FLAGS, ops->flags);
+
+ nla_nest_end(skb, nest);
+ }
+
+ nla_nest_end(skb, nla_ops);
+ }
+
+ if (!list_empty(&family->mcast_groups)) {
+ struct genl_multicast_group *grp;
+ struct nlattr *nla_grps;
+ int idx = 1;
+
+ nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
+ if (nla_grps == NULL)
+ goto nla_put_failure;
+
+ list_for_each_entry(grp, &family->mcast_groups, list) {
+ struct nlattr *nest;
+
+ nest = nla_nest_start(skb, idx++);
+ if (nest == NULL)
+ goto nla_put_failure;
+
+ NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id);
+ NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME,
+ grp->name);
+
+ nla_nest_end(skb, nest);
+ }
+ nla_nest_end(skb, nla_grps);
+ }
+
+ return genlmsg_end(skb, hdr);
+
+nla_put_failure:
+ genlmsg_cancel(skb, hdr);
+ return -EMSGSIZE;
+}
+
+static int ctrl_fill_mcgrp_info(struct genl_multicast_group *grp, u32 pid,
+ u32 seq, u32 flags, struct sk_buff *skb,
+ u8 cmd)
+{
+ void *hdr;
+ struct nlattr *nla_grps;
+ struct nlattr *nest;
+
+ hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
+ if (hdr == NULL)
+ return -1;
+
+ NLA_PUT_STRING(skb, CTRL_ATTR_FAMILY_NAME, grp->family->name);
+ NLA_PUT_U16(skb, CTRL_ATTR_FAMILY_ID, grp->family->id);
+
+ nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
+ if (nla_grps == NULL)
+ goto nla_put_failure;
+
+ nest = nla_nest_start(skb, 1);
+ if (nest == NULL)
+ goto nla_put_failure;
+
+ NLA_PUT_U32(skb, CTRL_ATTR_MCAST_GRP_ID, grp->id);
+ NLA_PUT_STRING(skb, CTRL_ATTR_MCAST_GRP_NAME,
+ grp->name);
+
+ nla_nest_end(skb, nest);
+ nla_nest_end(skb, nla_grps);
+
+ return genlmsg_end(skb, hdr);
+
+nla_put_failure:
+ genlmsg_cancel(skb, hdr);
+ return -EMSGSIZE;
+}
+
+static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
+{
+
+ int i, n = 0;
+ struct genl_family *rt;
+ int chains_to_skip = cb->args[0];
+ int fams_to_skip = cb->args[1];
+
+ for (i = 0; i < GENL_FAM_TAB_SIZE; i++) {
+ if (i < chains_to_skip)
+ continue;
+ n = 0;
+ list_for_each_entry(rt, genl_family_chain(i), family_list) {
+ if (++n < fams_to_skip)
+ continue;
+ if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).pid,
+ cb->nlh->nlmsg_seq, NLM_F_MULTI,
+ skb, CTRL_CMD_NEWFAMILY) < 0)
+ goto errout;
+ }
+
+ fams_to_skip = 0;
+ }
+
+errout:
+ cb->args[0] = i;
+ cb->args[1] = n;
+
+ return skb->len;
+}
+
+static struct sk_buff *ctrl_build_family_msg(struct genl_family *family,
+ u32 pid, int seq, u8 cmd)
+{
+ struct sk_buff *skb;
+ int err;
+
+ skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (skb == NULL)
+ return ERR_PTR(-ENOBUFS);
+
+ err = ctrl_fill_info(family, pid, seq, 0, skb, cmd);
+ if (err < 0) {
+ nlmsg_free(skb);
+ return ERR_PTR(err);
+ }
+
+ return skb;
+}
+
+static struct sk_buff *ctrl_build_mcgrp_msg(struct genl_multicast_group *grp,
+ u32 pid, int seq, u8 cmd)
+{
+ struct sk_buff *skb;
+ int err;
+
+ skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (skb == NULL)
+ return ERR_PTR(-ENOBUFS);
+
+ err = ctrl_fill_mcgrp_info(grp, pid, seq, 0, skb, cmd);
+ if (err < 0) {
+ nlmsg_free(skb);
+ return ERR_PTR(err);
+ }
+
+ return skb;
+}
+
+static const struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] = {
+ [CTRL_ATTR_FAMILY_ID] = { .type = NLA_U16 },
+ [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
+ .len = GENL_NAMSIZ - 1 },
+};
+
+static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
+{
+ struct sk_buff *msg;
+ struct genl_family *res = NULL;
+ int err = -EINVAL;
+
+ if (info->attrs[CTRL_ATTR_FAMILY_ID]) {
+ u16 id = nla_get_u16(info->attrs[CTRL_ATTR_FAMILY_ID]);
+ res = genl_family_find_byid(id);
+ }
+
+ if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
+ char *name;
+
+ name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
+ res = genl_family_find_byname(name);
+ }
+
+ if (res == NULL) {
+ err = -ENOENT;
+ goto errout;
+ }
+
+ msg = ctrl_build_family_msg(res, info->snd_pid, info->snd_seq,
+ CTRL_CMD_NEWFAMILY);
+ if (IS_ERR(msg)) {
+ err = PTR_ERR(msg);
+ goto errout;
+ }
+
+ err = genlmsg_reply(msg, info);
+errout:
+ return err;
+}
+
+static int genl_ctrl_event(int event, void *data)
+{
+ struct sk_buff *msg;
+
+ if (genl_sock == NULL)
+ return 0;
+
+ switch (event) {
+ case CTRL_CMD_NEWFAMILY:
+ case CTRL_CMD_DELFAMILY:
+ msg = ctrl_build_family_msg(data, 0, 0, event);
+ if (IS_ERR(msg))
+ return PTR_ERR(msg);
+
+ genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL);
+ break;
+ case CTRL_CMD_NEWMCAST_GRP:
+ case CTRL_CMD_DELMCAST_GRP:
+ msg = ctrl_build_mcgrp_msg(data, 0, 0, event);
+ if (IS_ERR(msg))
+ return PTR_ERR(msg);
+
+ genlmsg_multicast(msg, 0, GENL_ID_CTRL, GFP_KERNEL);
+ break;
+ }
+
+ return 0;
+}
+
+static struct genl_ops genl_ctrl_ops = {
+ .cmd = CTRL_CMD_GETFAMILY,
+ .doit = ctrl_getfamily,
+ .dumpit = ctrl_dumpfamily,
+ .policy = ctrl_policy,
+};
+
+static struct genl_multicast_group notify_grp = {
+ .name = "notify",
+};
+
+static int __init genl_init(void)
+{
+ int i, err;
+
+ for (i = 0; i < GENL_FAM_TAB_SIZE; i++)
+ INIT_LIST_HEAD(&family_ht[i]);
+
+ err = genl_register_family(&genl_ctrl);
+ if (err < 0)
+ goto errout;
+
+ err = genl_register_ops(&genl_ctrl, &genl_ctrl_ops);
+ if (err < 0)
+ goto errout_register;
+
+ netlink_set_nonroot(NETLINK_GENERIC, NL_NONROOT_RECV);
+
+ /* we'll bump the group number right afterwards */
+ genl_sock = netlink_kernel_create(&init_net, NETLINK_GENERIC, 0,
+ genl_rcv, &genl_mutex, THIS_MODULE);
+ if (genl_sock == NULL)
+ panic("GENL: Cannot initialize generic netlink\n");
+
+ err = genl_register_mc_group(&genl_ctrl, &notify_grp);
+ if (err < 0)
+ goto errout_register;
+
+ return 0;
+
+errout_register:
+ genl_unregister_family(&genl_ctrl);
+errout:
+ panic("GENL: Cannot register controller: %d\n", err);
+}
+
+subsys_initcall(genl_init);
+
+EXPORT_SYMBOL(genl_sock);
+EXPORT_SYMBOL(genl_register_ops);
+EXPORT_SYMBOL(genl_unregister_ops);
+EXPORT_SYMBOL(genl_register_family);
+EXPORT_SYMBOL(genl_unregister_family);
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