v4.19.13 snapshot.
diff --git a/net/netlink/Kconfig b/net/netlink/Kconfig
new file mode 100644
index 0000000..5d6e8c0
--- /dev/null
+++ b/net/netlink/Kconfig
@@ -0,0 +1,10 @@
+#
+# Netlink Sockets
+#
+
+config NETLINK_DIAG
+ tristate "NETLINK: socket monitoring interface"
+ default n
+ ---help---
+ Support for NETLINK socket monitoring interface used by the ss tool.
+ If unsure, say Y.
diff --git a/net/netlink/Makefile b/net/netlink/Makefile
new file mode 100644
index 0000000..e837917
--- /dev/null
+++ b/net/netlink/Makefile
@@ -0,0 +1,8 @@
+#
+# Makefile for the netlink driver.
+#
+
+obj-y := af_netlink.o genetlink.o
+
+obj-$(CONFIG_NETLINK_DIAG) += netlink_diag.o
+netlink_diag-y := diag.o
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
new file mode 100644
index 0000000..930d17f
--- /dev/null
+++ b/net/netlink/af_netlink.c
@@ -0,0 +1,2781 @@
+/*
+ * NETLINK Kernel-user communication protocol.
+ *
+ * Authors: Alan Cox <alan@lxorguk.ukuu.org.uk>
+ * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
+ * Patrick McHardy <kaber@trash.net>
+ *
+ * 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 <linux/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 <linux/vmalloc.h>
+#include <linux/if_arp.h>
+#include <linux/rhashtable.h>
+#include <asm/cacheflush.h>
+#include <linux/hash.h>
+#include <linux/genetlink.h>
+#include <linux/net_namespace.h>
+#include <linux/nospec.h>
+
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/sock.h>
+#include <net/scm.h>
+#include <net/netlink.h>
+
+#include "af_netlink.h"
+
+struct listeners {
+ struct rcu_head rcu;
+ unsigned long masks[0];
+};
+
+/* state bits */
+#define NETLINK_S_CONGESTED 0x0
+
+static inline int netlink_is_kernel(struct sock *sk)
+{
+ return nlk_sk(sk)->flags & NETLINK_F_KERNEL_SOCKET;
+}
+
+struct netlink_table *nl_table __read_mostly;
+EXPORT_SYMBOL_GPL(nl_table);
+
+static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
+
+static struct lock_class_key nlk_cb_mutex_keys[MAX_LINKS];
+
+static const char *const nlk_cb_mutex_key_strings[MAX_LINKS + 1] = {
+ "nlk_cb_mutex-ROUTE",
+ "nlk_cb_mutex-1",
+ "nlk_cb_mutex-USERSOCK",
+ "nlk_cb_mutex-FIREWALL",
+ "nlk_cb_mutex-SOCK_DIAG",
+ "nlk_cb_mutex-NFLOG",
+ "nlk_cb_mutex-XFRM",
+ "nlk_cb_mutex-SELINUX",
+ "nlk_cb_mutex-ISCSI",
+ "nlk_cb_mutex-AUDIT",
+ "nlk_cb_mutex-FIB_LOOKUP",
+ "nlk_cb_mutex-CONNECTOR",
+ "nlk_cb_mutex-NETFILTER",
+ "nlk_cb_mutex-IP6_FW",
+ "nlk_cb_mutex-DNRTMSG",
+ "nlk_cb_mutex-KOBJECT_UEVENT",
+ "nlk_cb_mutex-GENERIC",
+ "nlk_cb_mutex-17",
+ "nlk_cb_mutex-SCSITRANSPORT",
+ "nlk_cb_mutex-ECRYPTFS",
+ "nlk_cb_mutex-RDMA",
+ "nlk_cb_mutex-CRYPTO",
+ "nlk_cb_mutex-SMC",
+ "nlk_cb_mutex-23",
+ "nlk_cb_mutex-24",
+ "nlk_cb_mutex-25",
+ "nlk_cb_mutex-26",
+ "nlk_cb_mutex-27",
+ "nlk_cb_mutex-28",
+ "nlk_cb_mutex-29",
+ "nlk_cb_mutex-30",
+ "nlk_cb_mutex-31",
+ "nlk_cb_mutex-MAX_LINKS"
+};
+
+static int netlink_dump(struct sock *sk);
+
+/* nl_table locking explained:
+ * Lookup and traversal are protected with an RCU read-side lock. Insertion
+ * and removal are protected with per bucket lock while using RCU list
+ * modification primitives and may run in parallel to RCU protected lookups.
+ * Destruction of the Netlink socket may only occur *after* nl_table_lock has
+ * been acquired * either during or after the socket has been removed from
+ * the list and after an RCU grace period.
+ */
+DEFINE_RWLOCK(nl_table_lock);
+EXPORT_SYMBOL_GPL(nl_table_lock);
+static atomic_t nl_table_users = ATOMIC_INIT(0);
+
+#define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock));
+
+static BLOCKING_NOTIFIER_HEAD(netlink_chain);
+
+
+static const struct rhashtable_params netlink_rhashtable_params;
+
+static inline u32 netlink_group_mask(u32 group)
+{
+ return group ? 1 << (group - 1) : 0;
+}
+
+static struct sk_buff *netlink_to_full_skb(const struct sk_buff *skb,
+ gfp_t gfp_mask)
+{
+ unsigned int len = skb_end_offset(skb);
+ struct sk_buff *new;
+
+ new = alloc_skb(len, gfp_mask);
+ if (new == NULL)
+ return NULL;
+
+ NETLINK_CB(new).portid = NETLINK_CB(skb).portid;
+ NETLINK_CB(new).dst_group = NETLINK_CB(skb).dst_group;
+ NETLINK_CB(new).creds = NETLINK_CB(skb).creds;
+
+ skb_put_data(new, skb->data, len);
+ return new;
+}
+
+static unsigned int netlink_tap_net_id;
+
+struct netlink_tap_net {
+ struct list_head netlink_tap_all;
+ struct mutex netlink_tap_lock;
+};
+
+int netlink_add_tap(struct netlink_tap *nt)
+{
+ struct net *net = dev_net(nt->dev);
+ struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
+
+ if (unlikely(nt->dev->type != ARPHRD_NETLINK))
+ return -EINVAL;
+
+ mutex_lock(&nn->netlink_tap_lock);
+ list_add_rcu(&nt->list, &nn->netlink_tap_all);
+ mutex_unlock(&nn->netlink_tap_lock);
+
+ __module_get(nt->module);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(netlink_add_tap);
+
+static int __netlink_remove_tap(struct netlink_tap *nt)
+{
+ struct net *net = dev_net(nt->dev);
+ struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
+ bool found = false;
+ struct netlink_tap *tmp;
+
+ mutex_lock(&nn->netlink_tap_lock);
+
+ list_for_each_entry(tmp, &nn->netlink_tap_all, list) {
+ if (nt == tmp) {
+ list_del_rcu(&nt->list);
+ found = true;
+ goto out;
+ }
+ }
+
+ pr_warn("__netlink_remove_tap: %p not found\n", nt);
+out:
+ mutex_unlock(&nn->netlink_tap_lock);
+
+ if (found)
+ module_put(nt->module);
+
+ return found ? 0 : -ENODEV;
+}
+
+int netlink_remove_tap(struct netlink_tap *nt)
+{
+ int ret;
+
+ ret = __netlink_remove_tap(nt);
+ synchronize_net();
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(netlink_remove_tap);
+
+static __net_init int netlink_tap_init_net(struct net *net)
+{
+ struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
+
+ INIT_LIST_HEAD(&nn->netlink_tap_all);
+ mutex_init(&nn->netlink_tap_lock);
+ return 0;
+}
+
+static void __net_exit netlink_tap_exit_net(struct net *net)
+{
+}
+
+static struct pernet_operations netlink_tap_net_ops = {
+ .init = netlink_tap_init_net,
+ .exit = netlink_tap_exit_net,
+ .id = &netlink_tap_net_id,
+ .size = sizeof(struct netlink_tap_net),
+};
+
+static bool netlink_filter_tap(const struct sk_buff *skb)
+{
+ struct sock *sk = skb->sk;
+
+ /* We take the more conservative approach and
+ * whitelist socket protocols that may pass.
+ */
+ switch (sk->sk_protocol) {
+ case NETLINK_ROUTE:
+ case NETLINK_USERSOCK:
+ case NETLINK_SOCK_DIAG:
+ case NETLINK_NFLOG:
+ case NETLINK_XFRM:
+ case NETLINK_FIB_LOOKUP:
+ case NETLINK_NETFILTER:
+ case NETLINK_GENERIC:
+ return true;
+ }
+
+ return false;
+}
+
+static int __netlink_deliver_tap_skb(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ struct sk_buff *nskb;
+ struct sock *sk = skb->sk;
+ int ret = -ENOMEM;
+
+ if (!net_eq(dev_net(dev), sock_net(sk)))
+ return 0;
+
+ dev_hold(dev);
+
+ if (is_vmalloc_addr(skb->head))
+ nskb = netlink_to_full_skb(skb, GFP_ATOMIC);
+ else
+ nskb = skb_clone(skb, GFP_ATOMIC);
+ if (nskb) {
+ nskb->dev = dev;
+ nskb->protocol = htons((u16) sk->sk_protocol);
+ nskb->pkt_type = netlink_is_kernel(sk) ?
+ PACKET_KERNEL : PACKET_USER;
+ skb_reset_network_header(nskb);
+ ret = dev_queue_xmit(nskb);
+ if (unlikely(ret > 0))
+ ret = net_xmit_errno(ret);
+ }
+
+ dev_put(dev);
+ return ret;
+}
+
+static void __netlink_deliver_tap(struct sk_buff *skb, struct netlink_tap_net *nn)
+{
+ int ret;
+ struct netlink_tap *tmp;
+
+ if (!netlink_filter_tap(skb))
+ return;
+
+ list_for_each_entry_rcu(tmp, &nn->netlink_tap_all, list) {
+ ret = __netlink_deliver_tap_skb(skb, tmp->dev);
+ if (unlikely(ret))
+ break;
+ }
+}
+
+static void netlink_deliver_tap(struct net *net, struct sk_buff *skb)
+{
+ struct netlink_tap_net *nn = net_generic(net, netlink_tap_net_id);
+
+ rcu_read_lock();
+
+ if (unlikely(!list_empty(&nn->netlink_tap_all)))
+ __netlink_deliver_tap(skb, nn);
+
+ rcu_read_unlock();
+}
+
+static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src,
+ struct sk_buff *skb)
+{
+ if (!(netlink_is_kernel(dst) && netlink_is_kernel(src)))
+ netlink_deliver_tap(sock_net(dst), skb);
+}
+
+static void netlink_overrun(struct sock *sk)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ if (!(nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)) {
+ if (!test_and_set_bit(NETLINK_S_CONGESTED,
+ &nlk_sk(sk)->state)) {
+ sk->sk_err = ENOBUFS;
+ sk->sk_error_report(sk);
+ }
+ }
+ atomic_inc(&sk->sk_drops);
+}
+
+static void netlink_rcv_wake(struct sock *sk)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ if (skb_queue_empty(&sk->sk_receive_queue))
+ clear_bit(NETLINK_S_CONGESTED, &nlk->state);
+ if (!test_bit(NETLINK_S_CONGESTED, &nlk->state))
+ wake_up_interruptible(&nlk->wait);
+}
+
+static void netlink_skb_destructor(struct sk_buff *skb)
+{
+ if (is_vmalloc_addr(skb->head)) {
+ if (!skb->cloned ||
+ !atomic_dec_return(&(skb_shinfo(skb)->dataref)))
+ vfree(skb->head);
+
+ skb->head = NULL;
+ }
+ if (skb->sk != NULL)
+ sock_rfree(skb);
+}
+
+static void netlink_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
+{
+ WARN_ON(skb->sk != NULL);
+ skb->sk = sk;
+ skb->destructor = netlink_skb_destructor;
+ atomic_add(skb->truesize, &sk->sk_rmem_alloc);
+ sk_mem_charge(sk, skb->truesize);
+}
+
+static void netlink_sock_destruct(struct sock *sk)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ if (nlk->cb_running) {
+ if (nlk->cb.done)
+ nlk->cb.done(&nlk->cb);
+ module_put(nlk->cb.module);
+ kfree_skb(nlk->cb.skb);
+ }
+
+ 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(refcount_read(&sk->sk_wmem_alloc));
+ WARN_ON(nlk_sk(sk)->groups);
+}
+
+static void netlink_sock_destruct_work(struct work_struct *work)
+{
+ struct netlink_sock *nlk = container_of(work, struct netlink_sock,
+ work);
+
+ sk_free(&nlk->sk);
+}
+
+/* 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.
+ */
+
+void netlink_table_grab(void)
+ __acquires(nl_table_lock)
+{
+ might_sleep();
+
+ 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);
+ }
+}
+
+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);
+}
+
+struct netlink_compare_arg
+{
+ possible_net_t pnet;
+ u32 portid;
+};
+
+/* Doing sizeof directly may yield 4 extra bytes on 64-bit. */
+#define netlink_compare_arg_len \
+ (offsetof(struct netlink_compare_arg, portid) + sizeof(u32))
+
+static inline int netlink_compare(struct rhashtable_compare_arg *arg,
+ const void *ptr)
+{
+ const struct netlink_compare_arg *x = arg->key;
+ const struct netlink_sock *nlk = ptr;
+
+ return nlk->portid != x->portid ||
+ !net_eq(sock_net(&nlk->sk), read_pnet(&x->pnet));
+}
+
+static void netlink_compare_arg_init(struct netlink_compare_arg *arg,
+ struct net *net, u32 portid)
+{
+ memset(arg, 0, sizeof(*arg));
+ write_pnet(&arg->pnet, net);
+ arg->portid = portid;
+}
+
+static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid,
+ struct net *net)
+{
+ struct netlink_compare_arg arg;
+
+ netlink_compare_arg_init(&arg, net, portid);
+ return rhashtable_lookup_fast(&table->hash, &arg,
+ netlink_rhashtable_params);
+}
+
+static int __netlink_insert(struct netlink_table *table, struct sock *sk)
+{
+ struct netlink_compare_arg arg;
+
+ netlink_compare_arg_init(&arg, sock_net(sk), nlk_sk(sk)->portid);
+ return rhashtable_lookup_insert_key(&table->hash, &arg,
+ &nlk_sk(sk)->node,
+ netlink_rhashtable_params);
+}
+
+static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid)
+{
+ struct netlink_table *table = &nl_table[protocol];
+ struct sock *sk;
+
+ rcu_read_lock();
+ sk = __netlink_lookup(table, portid, net);
+ if (sk)
+ sock_hold(sk);
+ rcu_read_unlock();
+
+ return sk;
+}
+
+static const struct proto_ops netlink_ops;
+
+static void
+netlink_update_listeners(struct sock *sk)
+{
+ struct netlink_table *tbl = &nl_table[sk->sk_protocol];
+ unsigned long mask;
+ unsigned int i;
+ struct listeners *listeners;
+
+ listeners = nl_deref_protected(tbl->listeners);
+ if (!listeners)
+ return;
+
+ for (i = 0; i < NLGRPLONGS(tbl->groups); i++) {
+ mask = 0;
+ sk_for_each_bound(sk, &tbl->mc_list) {
+ if (i < NLGRPLONGS(nlk_sk(sk)->ngroups))
+ mask |= nlk_sk(sk)->groups[i];
+ }
+ listeners->masks[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, u32 portid)
+{
+ struct netlink_table *table = &nl_table[sk->sk_protocol];
+ int err;
+
+ lock_sock(sk);
+
+ err = nlk_sk(sk)->portid == portid ? 0 : -EBUSY;
+ if (nlk_sk(sk)->bound)
+ goto err;
+
+ err = -ENOMEM;
+ if (BITS_PER_LONG > 32 &&
+ unlikely(atomic_read(&table->hash.nelems) >= UINT_MAX))
+ goto err;
+
+ nlk_sk(sk)->portid = portid;
+ sock_hold(sk);
+
+ err = __netlink_insert(table, sk);
+ if (err) {
+ /* In case the hashtable backend returns with -EBUSY
+ * from here, it must not escape to the caller.
+ */
+ if (unlikely(err == -EBUSY))
+ err = -EOVERFLOW;
+ if (err == -EEXIST)
+ err = -EADDRINUSE;
+ sock_put(sk);
+ goto err;
+ }
+
+ /* We need to ensure that the socket is hashed and visible. */
+ smp_wmb();
+ nlk_sk(sk)->bound = portid;
+
+err:
+ release_sock(sk);
+ return err;
+}
+
+static void netlink_remove(struct sock *sk)
+{
+ struct netlink_table *table;
+
+ table = &nl_table[sk->sk_protocol];
+ if (!rhashtable_remove_fast(&table->hash, &nlk_sk(sk)->node,
+ netlink_rhashtable_params)) {
+ WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
+ __sock_put(sk);
+ }
+
+ netlink_table_grab();
+ if (nlk_sk(sk)->subscriptions) {
+ __sk_del_bind_node(sk);
+ netlink_update_listeners(sk);
+ }
+ if (sk->sk_protocol == NETLINK_GENERIC)
+ atomic_inc(&genl_sk_destructing_cnt);
+ 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,
+ int kern)
+{
+ struct sock *sk;
+ struct netlink_sock *nlk;
+
+ sock->ops = &netlink_ops;
+
+ sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto, kern);
+ 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);
+ lockdep_set_class_and_name(nlk->cb_mutex,
+ nlk_cb_mutex_keys + protocol,
+ nlk_cb_mutex_key_strings[protocol]);
+ }
+ 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,
+ int kern)
+{
+ struct module *module = NULL;
+ struct mutex *cb_mutex;
+ struct netlink_sock *nlk;
+ int (*bind)(struct net *net, int group);
+ void (*unbind)(struct net *net, int group);
+ 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;
+ protocol = array_index_nospec(protocol, MAX_LINKS);
+
+ 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;
+ else
+ err = -EPROTONOSUPPORT;
+ cb_mutex = nl_table[protocol].cb_mutex;
+ bind = nl_table[protocol].bind;
+ unbind = nl_table[protocol].unbind;
+ netlink_unlock_table();
+
+ if (err < 0)
+ goto out;
+
+ err = __netlink_create(net, sock, cb_mutex, protocol, kern);
+ if (err < 0)
+ goto out_module;
+
+ local_bh_disable();
+ sock_prot_inuse_add(net, &netlink_proto, 1);
+ local_bh_enable();
+
+ nlk = nlk_sk(sock->sk);
+ nlk->module = module;
+ nlk->netlink_bind = bind;
+ nlk->netlink_unbind = unbind;
+out:
+ return err;
+
+out_module:
+ module_put(module);
+ goto out;
+}
+
+static void deferred_put_nlk_sk(struct rcu_head *head)
+{
+ struct netlink_sock *nlk = container_of(head, struct netlink_sock, rcu);
+ struct sock *sk = &nlk->sk;
+
+ kfree(nlk->groups);
+ nlk->groups = NULL;
+
+ if (!refcount_dec_and_test(&sk->sk_refcnt))
+ return;
+
+ if (nlk->cb_running && nlk->cb.done) {
+ INIT_WORK(&nlk->work, netlink_sock_destruct_work);
+ schedule_work(&nlk->work);
+ return;
+ }
+
+ sk_free(sk);
+}
+
+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.
+ */
+
+ /* must not acquire netlink_table_lock in any way again before unbind
+ * and notifying genetlink is done as otherwise it might deadlock
+ */
+ if (nlk->netlink_unbind) {
+ int i;
+
+ for (i = 0; i < nlk->ngroups; i++)
+ if (test_bit(i, nlk->groups))
+ nlk->netlink_unbind(sock_net(sk), i + 1);
+ }
+ if (sk->sk_protocol == NETLINK_GENERIC &&
+ atomic_dec_return(&genl_sk_destructing_cnt) == 0)
+ wake_up(&genl_sk_destructing_waitq);
+
+ sock->sk = NULL;
+ wake_up_interruptible_all(&nlk->wait);
+
+ skb_queue_purge(&sk->sk_write_queue);
+
+ if (nlk->portid && nlk->bound) {
+ struct netlink_notify n = {
+ .net = sock_net(sk),
+ .protocol = sk->sk_protocol,
+ .portid = nlk->portid,
+ };
+ blocking_notifier_call_chain(&netlink_chain,
+ NETLINK_URELEASE, &n);
+ }
+
+ module_put(nlk->module);
+
+ if (netlink_is_kernel(sk)) {
+ netlink_table_grab();
+ BUG_ON(nl_table[sk->sk_protocol].registered == 0);
+ if (--nl_table[sk->sk_protocol].registered == 0) {
+ struct listeners *old;
+
+ old = nl_deref_protected(nl_table[sk->sk_protocol].listeners);
+ RCU_INIT_POINTER(nl_table[sk->sk_protocol].listeners, NULL);
+ kfree_rcu(old, rcu);
+ nl_table[sk->sk_protocol].module = NULL;
+ nl_table[sk->sk_protocol].bind = NULL;
+ nl_table[sk->sk_protocol].unbind = NULL;
+ nl_table[sk->sk_protocol].flags = 0;
+ nl_table[sk->sk_protocol].registered = 0;
+ }
+ netlink_table_ungrab();
+ }
+
+ local_bh_disable();
+ sock_prot_inuse_add(sock_net(sk), &netlink_proto, -1);
+ local_bh_enable();
+ call_rcu(&nlk->rcu, deferred_put_nlk_sk);
+ return 0;
+}
+
+static int netlink_autobind(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+ struct net *net = sock_net(sk);
+ struct netlink_table *table = &nl_table[sk->sk_protocol];
+ s32 portid = task_tgid_vnr(current);
+ int err;
+ s32 rover = -4096;
+ bool ok;
+
+retry:
+ cond_resched();
+ rcu_read_lock();
+ ok = !__netlink_lookup(table, portid, net);
+ rcu_read_unlock();
+ if (!ok) {
+ /* Bind collision, search negative portid values. */
+ if (rover == -4096)
+ /* rover will be in range [S32_MIN, -4097] */
+ rover = S32_MIN + prandom_u32_max(-4096 - S32_MIN);
+ else if (rover >= -4096)
+ rover = -4097;
+ portid = rover--;
+ goto retry;
+ }
+
+ err = netlink_insert(sk, portid);
+ if (err == -EADDRINUSE)
+ goto retry;
+
+ /* If 2 threads race to autobind, that is fine. */
+ if (err == -EBUSY)
+ err = 0;
+
+ return err;
+}
+
+/**
+ * __netlink_ns_capable - General netlink message capability test
+ * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace.
+ * @user_ns: The user namespace of the capability to use
+ * @cap: The capability to use
+ *
+ * Test to see if the opener of the socket we received the message
+ * from had when the netlink socket was created and the sender of the
+ * message has has the capability @cap in the user namespace @user_ns.
+ */
+bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
+ struct user_namespace *user_ns, int cap)
+{
+ return ((nsp->flags & NETLINK_SKB_DST) ||
+ file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) &&
+ ns_capable(user_ns, cap);
+}
+EXPORT_SYMBOL(__netlink_ns_capable);
+
+/**
+ * netlink_ns_capable - General netlink message capability test
+ * @skb: socket buffer holding a netlink command from userspace
+ * @user_ns: The user namespace of the capability to use
+ * @cap: The capability to use
+ *
+ * Test to see if the opener of the socket we received the message
+ * from had when the netlink socket was created and the sender of the
+ * message has has the capability @cap in the user namespace @user_ns.
+ */
+bool netlink_ns_capable(const struct sk_buff *skb,
+ struct user_namespace *user_ns, int cap)
+{
+ return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap);
+}
+EXPORT_SYMBOL(netlink_ns_capable);
+
+/**
+ * netlink_capable - Netlink global message capability test
+ * @skb: socket buffer holding a netlink command from userspace
+ * @cap: The capability to use
+ *
+ * Test to see if the opener of the socket we received the message
+ * from had when the netlink socket was created and the sender of the
+ * message has has the capability @cap in all user namespaces.
+ */
+bool netlink_capable(const struct sk_buff *skb, int cap)
+{
+ return netlink_ns_capable(skb, &init_user_ns, cap);
+}
+EXPORT_SYMBOL(netlink_capable);
+
+/**
+ * netlink_net_capable - Netlink network namespace message capability test
+ * @skb: socket buffer holding a netlink command from userspace
+ * @cap: The capability to use
+ *
+ * Test to see if the opener of the socket we received the message
+ * from had when the netlink socket was created and the sender of the
+ * message has has the capability @cap over the network namespace of
+ * the socket we received the message from.
+ */
+bool netlink_net_capable(const struct sk_buff *skb, int cap)
+{
+ return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap);
+}
+EXPORT_SYMBOL(netlink_net_capable);
+
+static inline int netlink_allowed(const struct socket *sock, unsigned int flag)
+{
+ return (nl_table[sock->sk->sk_protocol].flags & flag) ||
+ ns_capable(sock_net(sock->sk)->user_ns, 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 void netlink_undo_bind(int group, long unsigned int groups,
+ struct sock *sk)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+ int undo;
+
+ if (!nlk->netlink_unbind)
+ return;
+
+ for (undo = 0; undo < group; undo++)
+ if (test_bit(undo, &groups))
+ nlk->netlink_unbind(sock_net(sk), undo + 1);
+}
+
+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 = 0;
+ long unsigned int groups = nladdr->nl_groups;
+ bool bound;
+
+ if (addr_len < sizeof(struct sockaddr_nl))
+ return -EINVAL;
+
+ if (nladdr->nl_family != AF_NETLINK)
+ return -EINVAL;
+
+ /* Only superuser is allowed to listen multicasts */
+ if (groups) {
+ if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
+ return -EPERM;
+ err = netlink_realloc_groups(sk);
+ if (err)
+ return err;
+ }
+
+ if (nlk->ngroups == 0)
+ groups = 0;
+ else if (nlk->ngroups < 8*sizeof(groups))
+ groups &= (1UL << nlk->ngroups) - 1;
+
+ bound = nlk->bound;
+ if (bound) {
+ /* Ensure nlk->portid is up-to-date. */
+ smp_rmb();
+
+ if (nladdr->nl_pid != nlk->portid)
+ return -EINVAL;
+ }
+
+ netlink_lock_table();
+ if (nlk->netlink_bind && groups) {
+ int group;
+
+ for (group = 0; group < nlk->ngroups; group++) {
+ if (!test_bit(group, &groups))
+ continue;
+ err = nlk->netlink_bind(net, group + 1);
+ if (!err)
+ continue;
+ netlink_undo_bind(group, groups, sk);
+ goto unlock;
+ }
+ }
+
+ /* No need for barriers here as we return to user-space without
+ * using any of the bound attributes.
+ */
+ if (!bound) {
+ err = nladdr->nl_pid ?
+ netlink_insert(sk, nladdr->nl_pid) :
+ netlink_autobind(sock);
+ if (err) {
+ netlink_undo_bind(nlk->ngroups, groups, sk);
+ goto unlock;
+ }
+ }
+
+ if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
+ goto unlock;
+ netlink_unlock_table();
+
+ netlink_table_grab();
+ netlink_update_subscriptions(sk, nlk->subscriptions +
+ hweight32(groups) -
+ hweight32(nlk->groups[0]));
+ nlk->groups[0] = (nlk->groups[0] & ~0xffffffffUL) | groups;
+ netlink_update_listeners(sk);
+ netlink_table_ungrab();
+
+ return 0;
+
+unlock:
+ netlink_unlock_table();
+ return err;
+}
+
+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 (alen < sizeof(addr->sa_family))
+ return -EINVAL;
+
+ if (addr->sa_family == AF_UNSPEC) {
+ sk->sk_state = NETLINK_UNCONNECTED;
+ nlk->dst_portid = 0;
+ nlk->dst_group = 0;
+ return 0;
+ }
+ if (addr->sa_family != AF_NETLINK)
+ return -EINVAL;
+
+ if (alen < sizeof(struct sockaddr_nl))
+ return -EINVAL;
+
+ if ((nladdr->nl_groups || nladdr->nl_pid) &&
+ !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
+ return -EPERM;
+
+ /* No need for barriers here as we return to user-space without
+ * using any of the bound attributes.
+ */
+ if (!nlk->bound)
+ err = netlink_autobind(sock);
+
+ if (err == 0) {
+ sk->sk_state = NETLINK_CONNECTED;
+ nlk->dst_portid = nladdr->nl_pid;
+ nlk->dst_group = ffs(nladdr->nl_groups);
+ }
+
+ return err;
+}
+
+static int netlink_getname(struct socket *sock, struct sockaddr *addr,
+ int peer)
+{
+ struct sock *sk = sock->sk;
+ struct netlink_sock *nlk = nlk_sk(sk);
+ DECLARE_SOCKADDR(struct sockaddr_nl *, nladdr, addr);
+
+ nladdr->nl_family = AF_NETLINK;
+ nladdr->nl_pad = 0;
+
+ if (peer) {
+ nladdr->nl_pid = nlk->dst_portid;
+ nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
+ } else {
+ nladdr->nl_pid = nlk->portid;
+ netlink_lock_table();
+ nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
+ netlink_unlock_table();
+ }
+ return sizeof(*nladdr);
+}
+
+static int netlink_ioctl(struct socket *sock, unsigned int cmd,
+ unsigned long arg)
+{
+ /* try to hand this ioctl down to the NIC drivers.
+ */
+ return -ENOIOCTLCMD;
+}
+
+static struct sock *netlink_getsockbyportid(struct sock *ssk, u32 portid)
+{
+ struct sock *sock;
+ struct netlink_sock *nlk;
+
+ sock = netlink_lookup(sock_net(ssk), ssk->sk_protocol, portid);
+ 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_portid != nlk_sk(ssk)->portid) {
+ sock_put(sock);
+ return ERR_PTR(-ECONNREFUSED);
+ }
+ return sock;
+}
+
+struct sock *netlink_getsockbyfilp(struct file *filp)
+{
+ struct inode *inode = file_inode(filp);
+ 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;
+}
+
+static struct sk_buff *netlink_alloc_large_skb(unsigned int size,
+ int broadcast)
+{
+ struct sk_buff *skb;
+ void *data;
+
+ if (size <= NLMSG_GOODSIZE || broadcast)
+ return alloc_skb(size, GFP_KERNEL);
+
+ size = SKB_DATA_ALIGN(size) +
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+
+ data = vmalloc(size);
+ if (data == NULL)
+ return NULL;
+
+ skb = __build_skb(data, size);
+ if (skb == NULL)
+ vfree(data);
+ else
+ skb->destructor = netlink_skb_destructor;
+
+ return skb;
+}
+
+/*
+ * 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(NETLINK_S_CONGESTED, &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(NETLINK_S_CONGESTED, &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;
+ }
+ netlink_skb_set_owner_r(skb, sk);
+ return 0;
+}
+
+static int __netlink_sendskb(struct sock *sk, struct sk_buff *skb)
+{
+ int len = skb->len;
+
+ netlink_deliver_tap(sock_net(sk), skb);
+
+ skb_queue_tail(&sk->sk_receive_queue, skb);
+ sk->sk_data_ready(sk);
+ return len;
+}
+
+int netlink_sendskb(struct sock *sk, struct sk_buff *skb)
+{
+ int len = __netlink_sendskb(sk, skb);
+
+ sock_put(sk);
+ return len;
+}
+
+void netlink_detachskb(struct sock *sk, struct sk_buff *skb)
+{
+ kfree_skb(skb);
+ sock_put(sk);
+}
+
+static struct sk_buff *netlink_trim(struct sk_buff *skb, gfp_t allocation)
+{
+ int delta;
+
+ WARN_ON(skb->sk != NULL);
+ delta = skb->end - skb->tail;
+ if (is_vmalloc_addr(skb->head) || delta * 2 < skb->truesize)
+ return skb;
+
+ if (skb_shared(skb)) {
+ struct sk_buff *nskb = skb_clone(skb, allocation);
+ if (!nskb)
+ return skb;
+ consume_skb(skb);
+ skb = nskb;
+ }
+
+ pskb_expand_head(skb, 0, -delta,
+ (allocation & ~__GFP_DIRECT_RECLAIM) |
+ __GFP_NOWARN | __GFP_NORETRY);
+ return skb;
+}
+
+static int netlink_unicast_kernel(struct sock *sk, struct sk_buff *skb,
+ struct sock *ssk)
+{
+ int ret;
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ ret = -ECONNREFUSED;
+ if (nlk->netlink_rcv != NULL) {
+ ret = skb->len;
+ netlink_skb_set_owner_r(skb, sk);
+ NETLINK_CB(skb).sk = ssk;
+ netlink_deliver_tap_kernel(sk, ssk, skb);
+ nlk->netlink_rcv(skb);
+ consume_skb(skb);
+ } else {
+ kfree_skb(skb);
+ }
+ sock_put(sk);
+ return ret;
+}
+
+int netlink_unicast(struct sock *ssk, struct sk_buff *skb,
+ u32 portid, int nonblock)
+{
+ struct sock *sk;
+ int err;
+ long timeo;
+
+ skb = netlink_trim(skb, gfp_any());
+
+ timeo = sock_sndtimeo(ssk, nonblock);
+retry:
+ sk = netlink_getsockbyportid(ssk, portid);
+ if (IS_ERR(sk)) {
+ kfree_skb(skb);
+ return PTR_ERR(sk);
+ }
+ if (netlink_is_kernel(sk))
+ return netlink_unicast_kernel(sk, skb, ssk);
+
+ 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;
+ struct listeners *listeners;
+
+ BUG_ON(!netlink_is_kernel(sk));
+
+ rcu_read_lock();
+ listeners = rcu_dereference(nl_table[sk->sk_protocol].listeners);
+
+ if (listeners && group - 1 < nl_table[sk->sk_protocol].groups)
+ res = test_bit(group - 1, listeners->masks);
+
+ rcu_read_unlock();
+
+ return res;
+}
+EXPORT_SYMBOL_GPL(netlink_has_listeners);
+
+static 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(NETLINK_S_CONGESTED, &nlk->state)) {
+ netlink_skb_set_owner_r(skb, sk);
+ __netlink_sendskb(sk, skb);
+ return atomic_read(&sk->sk_rmem_alloc) > (sk->sk_rcvbuf >> 1);
+ }
+ return -1;
+}
+
+struct netlink_broadcast_data {
+ struct sock *exclude_sk;
+ struct net *net;
+ u32 portid;
+ u32 group;
+ int failure;
+ int delivery_failure;
+ int congested;
+ int delivered;
+ gfp_t allocation;
+ struct sk_buff *skb, *skb2;
+ int (*tx_filter)(struct sock *dsk, struct sk_buff *skb, void *data);
+ void *tx_data;
+};
+
+static void 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)
+ return;
+
+ if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups ||
+ !test_bit(p->group - 1, nlk->groups))
+ return;
+
+ if (!net_eq(sock_net(sk), p->net)) {
+ if (!(nlk->flags & NETLINK_F_LISTEN_ALL_NSID))
+ return;
+
+ if (!peernet_has_id(sock_net(sk), p->net))
+ return;
+
+ if (!file_ns_capable(sk->sk_socket->file, p->net->user_ns,
+ CAP_NET_BROADCAST))
+ return;
+ }
+
+ if (p->failure) {
+ netlink_overrun(sk);
+ return;
+ }
+
+ 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;
+ if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR)
+ p->delivery_failure = 1;
+ goto out;
+ }
+ if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) {
+ kfree_skb(p->skb2);
+ p->skb2 = NULL;
+ goto out;
+ }
+ if (sk_filter(sk, p->skb2)) {
+ kfree_skb(p->skb2);
+ p->skb2 = NULL;
+ goto out;
+ }
+ NETLINK_CB(p->skb2).nsid = peernet2id(sock_net(sk), p->net);
+ if (NETLINK_CB(p->skb2).nsid != NETNSA_NSID_NOT_ASSIGNED)
+ NETLINK_CB(p->skb2).nsid_is_set = true;
+ val = netlink_broadcast_deliver(sk, p->skb2);
+ if (val < 0) {
+ netlink_overrun(sk);
+ if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR)
+ p->delivery_failure = 1;
+ } else {
+ p->congested |= val;
+ p->delivered = 1;
+ p->skb2 = NULL;
+ }
+out:
+ sock_put(sk);
+}
+
+int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb, u32 portid,
+ u32 group, gfp_t allocation,
+ int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
+ void *filter_data)
+{
+ struct net *net = sock_net(ssk);
+ struct netlink_broadcast_data info;
+ struct sock *sk;
+
+ skb = netlink_trim(skb, allocation);
+
+ info.exclude_sk = ssk;
+ info.net = net;
+ info.portid = portid;
+ info.group = group;
+ info.failure = 0;
+ info.delivery_failure = 0;
+ info.congested = 0;
+ info.delivered = 0;
+ info.allocation = allocation;
+ info.skb = skb;
+ info.skb2 = NULL;
+ info.tx_filter = filter;
+ info.tx_data = filter_data;
+
+ /* While we sleep in clone, do not allow to change socket list */
+
+ netlink_lock_table();
+
+ sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list)
+ do_one_broadcast(sk, &info);
+
+ consume_skb(skb);
+
+ netlink_unlock_table();
+
+ if (info.delivery_failure) {
+ kfree_skb(info.skb2);
+ return -ENOBUFS;
+ }
+ consume_skb(info.skb2);
+
+ if (info.delivered) {
+ if (info.congested && gfpflags_allow_blocking(allocation))
+ yield();
+ return 0;
+ }
+ return -ESRCH;
+}
+EXPORT_SYMBOL(netlink_broadcast_filtered);
+
+int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 portid,
+ u32 group, gfp_t allocation)
+{
+ return netlink_broadcast_filtered(ssk, skb, portid, group, allocation,
+ NULL, NULL);
+}
+EXPORT_SYMBOL(netlink_broadcast);
+
+struct netlink_set_err_data {
+ struct sock *exclude_sk;
+ u32 portid;
+ u32 group;
+ int code;
+};
+
+static int do_one_set_err(struct sock *sk, struct netlink_set_err_data *p)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+ int ret = 0;
+
+ if (sk == p->exclude_sk)
+ goto out;
+
+ if (!net_eq(sock_net(sk), sock_net(p->exclude_sk)))
+ goto out;
+
+ if (nlk->portid == p->portid || p->group - 1 >= nlk->ngroups ||
+ !test_bit(p->group - 1, nlk->groups))
+ goto out;
+
+ if (p->code == ENOBUFS && nlk->flags & NETLINK_F_RECV_NO_ENOBUFS) {
+ ret = 1;
+ goto out;
+ }
+
+ sk->sk_err = p->code;
+ sk->sk_error_report(sk);
+out:
+ return ret;
+}
+
+/**
+ * netlink_set_err - report error to broadcast listeners
+ * @ssk: the kernel netlink socket, as returned by netlink_kernel_create()
+ * @portid: the PORTID of a process that we want to skip (if any)
+ * @group: the broadcast group that will notice the error
+ * @code: error code, must be negative (as usual in kernelspace)
+ *
+ * This function returns the number of broadcast listeners that have set the
+ * NETLINK_NO_ENOBUFS socket option.
+ */
+int netlink_set_err(struct sock *ssk, u32 portid, u32 group, int code)
+{
+ struct netlink_set_err_data info;
+ struct sock *sk;
+ int ret = 0;
+
+ info.exclude_sk = ssk;
+ info.portid = portid;
+ info.group = group;
+ /* sk->sk_err wants a positive error value */
+ info.code = -code;
+
+ read_lock(&nl_table_lock);
+
+ sk_for_each_bound(sk, &nl_table[ssk->sk_protocol].mc_list)
+ ret += do_one_set_err(sk, &info);
+
+ read_unlock(&nl_table_lock);
+ return ret;
+}
+EXPORT_SYMBOL(netlink_set_err);
+
+/* 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, unsigned 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_F_RECV_PKTINFO;
+ else
+ nlk->flags &= ~NETLINK_F_RECV_PKTINFO;
+ err = 0;
+ break;
+ case NETLINK_ADD_MEMBERSHIP:
+ case NETLINK_DROP_MEMBERSHIP: {
+ if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
+ return -EPERM;
+ err = netlink_realloc_groups(sk);
+ if (err)
+ return err;
+ if (!val || val - 1 >= nlk->ngroups)
+ return -EINVAL;
+ if (optname == NETLINK_ADD_MEMBERSHIP && nlk->netlink_bind) {
+ err = nlk->netlink_bind(sock_net(sk), val);
+ if (err)
+ return err;
+ }
+ netlink_table_grab();
+ netlink_update_socket_mc(nlk, val,
+ optname == NETLINK_ADD_MEMBERSHIP);
+ netlink_table_ungrab();
+ if (optname == NETLINK_DROP_MEMBERSHIP && nlk->netlink_unbind)
+ nlk->netlink_unbind(sock_net(sk), val);
+
+ err = 0;
+ break;
+ }
+ case NETLINK_BROADCAST_ERROR:
+ if (val)
+ nlk->flags |= NETLINK_F_BROADCAST_SEND_ERROR;
+ else
+ nlk->flags &= ~NETLINK_F_BROADCAST_SEND_ERROR;
+ err = 0;
+ break;
+ case NETLINK_NO_ENOBUFS:
+ if (val) {
+ nlk->flags |= NETLINK_F_RECV_NO_ENOBUFS;
+ clear_bit(NETLINK_S_CONGESTED, &nlk->state);
+ wake_up_interruptible(&nlk->wait);
+ } else {
+ nlk->flags &= ~NETLINK_F_RECV_NO_ENOBUFS;
+ }
+ err = 0;
+ break;
+ case NETLINK_LISTEN_ALL_NSID:
+ if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_BROADCAST))
+ return -EPERM;
+
+ if (val)
+ nlk->flags |= NETLINK_F_LISTEN_ALL_NSID;
+ else
+ nlk->flags &= ~NETLINK_F_LISTEN_ALL_NSID;
+ err = 0;
+ break;
+ case NETLINK_CAP_ACK:
+ if (val)
+ nlk->flags |= NETLINK_F_CAP_ACK;
+ else
+ nlk->flags &= ~NETLINK_F_CAP_ACK;
+ err = 0;
+ break;
+ case NETLINK_EXT_ACK:
+ if (val)
+ nlk->flags |= NETLINK_F_EXT_ACK;
+ else
+ nlk->flags &= ~NETLINK_F_EXT_ACK;
+ 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_F_RECV_PKTINFO ? 1 : 0;
+ if (put_user(len, optlen) ||
+ put_user(val, optval))
+ return -EFAULT;
+ err = 0;
+ break;
+ case NETLINK_BROADCAST_ERROR:
+ if (len < sizeof(int))
+ return -EINVAL;
+ len = sizeof(int);
+ val = nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR ? 1 : 0;
+ if (put_user(len, optlen) ||
+ put_user(val, optval))
+ return -EFAULT;
+ err = 0;
+ break;
+ case NETLINK_NO_ENOBUFS:
+ if (len < sizeof(int))
+ return -EINVAL;
+ len = sizeof(int);
+ val = nlk->flags & NETLINK_F_RECV_NO_ENOBUFS ? 1 : 0;
+ if (put_user(len, optlen) ||
+ put_user(val, optval))
+ return -EFAULT;
+ err = 0;
+ break;
+ case NETLINK_LIST_MEMBERSHIPS: {
+ int pos, idx, shift;
+
+ err = 0;
+ netlink_lock_table();
+ for (pos = 0; pos * 8 < nlk->ngroups; pos += sizeof(u32)) {
+ if (len - pos < sizeof(u32))
+ break;
+
+ idx = pos / sizeof(unsigned long);
+ shift = (pos % sizeof(unsigned long)) * 8;
+ if (put_user((u32)(nlk->groups[idx] >> shift),
+ (u32 __user *)(optval + pos))) {
+ err = -EFAULT;
+ break;
+ }
+ }
+ if (put_user(ALIGN(nlk->ngroups / 8, sizeof(u32)), optlen))
+ err = -EFAULT;
+ netlink_unlock_table();
+ break;
+ }
+ case NETLINK_CAP_ACK:
+ if (len < sizeof(int))
+ return -EINVAL;
+ len = sizeof(int);
+ val = nlk->flags & NETLINK_F_CAP_ACK ? 1 : 0;
+ if (put_user(len, optlen) ||
+ put_user(val, optval))
+ return -EFAULT;
+ err = 0;
+ break;
+ case NETLINK_EXT_ACK:
+ if (len < sizeof(int))
+ return -EINVAL;
+ len = sizeof(int);
+ val = nlk->flags & NETLINK_F_EXT_ACK ? 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 void netlink_cmsg_listen_all_nsid(struct sock *sk, struct msghdr *msg,
+ struct sk_buff *skb)
+{
+ if (!NETLINK_CB(skb).nsid_is_set)
+ return;
+
+ put_cmsg(msg, SOL_NETLINK, NETLINK_LISTEN_ALL_NSID, sizeof(int),
+ &NETLINK_CB(skb).nsid);
+}
+
+static int netlink_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
+{
+ struct sock *sk = sock->sk;
+ struct netlink_sock *nlk = nlk_sk(sk);
+ DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
+ u32 dst_portid;
+ u32 dst_group;
+ struct sk_buff *skb;
+ int err;
+ struct scm_cookie scm;
+ u32 netlink_skb_flags = 0;
+
+ if (msg->msg_flags&MSG_OOB)
+ return -EOPNOTSUPP;
+
+ err = scm_send(sock, msg, &scm, true);
+ if (err < 0)
+ return err;
+
+ if (msg->msg_namelen) {
+ err = -EINVAL;
+ if (msg->msg_namelen < sizeof(struct sockaddr_nl))
+ goto out;
+ if (addr->nl_family != AF_NETLINK)
+ goto out;
+ dst_portid = addr->nl_pid;
+ dst_group = ffs(addr->nl_groups);
+ err = -EPERM;
+ if ((dst_group || dst_portid) &&
+ !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
+ goto out;
+ netlink_skb_flags |= NETLINK_SKB_DST;
+ } else {
+ dst_portid = nlk->dst_portid;
+ dst_group = nlk->dst_group;
+ }
+
+ if (!nlk->bound) {
+ err = netlink_autobind(sock);
+ if (err)
+ goto out;
+ } else {
+ /* Ensure nlk is hashed and visible. */
+ smp_rmb();
+ }
+
+ err = -EMSGSIZE;
+ if (len > sk->sk_sndbuf - 32)
+ goto out;
+ err = -ENOBUFS;
+ skb = netlink_alloc_large_skb(len, dst_group);
+ if (skb == NULL)
+ goto out;
+
+ NETLINK_CB(skb).portid = nlk->portid;
+ NETLINK_CB(skb).dst_group = dst_group;
+ NETLINK_CB(skb).creds = scm.creds;
+ NETLINK_CB(skb).flags = netlink_skb_flags;
+
+ err = -EFAULT;
+ if (memcpy_from_msg(skb_put(skb, len), msg, len)) {
+ kfree_skb(skb);
+ goto out;
+ }
+
+ err = security_netlink_send(sk, skb);
+ if (err) {
+ kfree_skb(skb);
+ goto out;
+ }
+
+ if (dst_group) {
+ refcount_inc(&skb->users);
+ netlink_broadcast(sk, skb, dst_portid, dst_group, GFP_KERNEL);
+ }
+ err = netlink_unicast(sk, skb, dst_portid, msg->msg_flags&MSG_DONTWAIT);
+
+out:
+ scm_destroy(&scm);
+ return err;
+}
+
+static int netlink_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
+ int flags)
+{
+ 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, *data_skb;
+ int err, ret;
+
+ if (flags&MSG_OOB)
+ return -EOPNOTSUPP;
+
+ copied = 0;
+
+ skb = skb_recv_datagram(sk, flags, noblock, &err);
+ if (skb == NULL)
+ goto out;
+
+ data_skb = skb;
+
+#ifdef CONFIG_COMPAT_NETLINK_MESSAGES
+ if (unlikely(skb_shinfo(skb)->frag_list)) {
+ /*
+ * If this skb has a frag_list, then here that means that we
+ * will have to use the frag_list skb's data for compat tasks
+ * and the regular skb's data for normal (non-compat) tasks.
+ *
+ * If we need to send the compat skb, assign it to the
+ * 'data_skb' variable so that it will be used below for data
+ * copying. We keep 'skb' for everything else, including
+ * freeing both later.
+ */
+ if (flags & MSG_CMSG_COMPAT)
+ data_skb = skb_shinfo(skb)->frag_list;
+ }
+#endif
+
+ /* Record the max length of recvmsg() calls for future allocations */
+ nlk->max_recvmsg_len = max(nlk->max_recvmsg_len, len);
+ nlk->max_recvmsg_len = min_t(size_t, nlk->max_recvmsg_len,
+ SKB_WITH_OVERHEAD(32768));
+
+ copied = data_skb->len;
+ if (len < copied) {
+ msg->msg_flags |= MSG_TRUNC;
+ copied = len;
+ }
+
+ skb_reset_transport_header(data_skb);
+ err = skb_copy_datagram_msg(data_skb, 0, msg, copied);
+
+ if (msg->msg_name) {
+ DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
+ addr->nl_family = AF_NETLINK;
+ addr->nl_pad = 0;
+ addr->nl_pid = NETLINK_CB(skb).portid;
+ addr->nl_groups = netlink_group_mask(NETLINK_CB(skb).dst_group);
+ msg->msg_namelen = sizeof(*addr);
+ }
+
+ if (nlk->flags & NETLINK_F_RECV_PKTINFO)
+ netlink_cmsg_recv_pktinfo(msg, skb);
+ if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID)
+ netlink_cmsg_listen_all_nsid(sk, msg, skb);
+
+ memset(&scm, 0, sizeof(scm));
+ scm.creds = *NETLINK_CREDS(skb);
+ if (flags & MSG_TRUNC)
+ copied = data_skb->len;
+
+ skb_free_datagram(sk, skb);
+
+ if (nlk->cb_running &&
+ atomic_read(&sk->sk_rmem_alloc) <= sk->sk_rcvbuf / 2) {
+ ret = netlink_dump(sk);
+ if (ret) {
+ sk->sk_err = -ret;
+ sk->sk_error_report(sk);
+ }
+ }
+
+ scm_recv(sock, msg, &scm, flags);
+out:
+ netlink_rcv_wake(sk);
+ return err ? : copied;
+}
+
+static void netlink_data_ready(struct sock *sk)
+{
+ 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, struct module *module,
+ struct netlink_kernel_cfg *cfg)
+{
+ struct socket *sock;
+ struct sock *sk;
+ struct netlink_sock *nlk;
+ struct listeners *listeners = NULL;
+ struct mutex *cb_mutex = cfg ? cfg->cb_mutex : NULL;
+ unsigned int groups;
+
+ BUG_ON(!nl_table);
+
+ if (unit < 0 || unit >= MAX_LINKS)
+ return NULL;
+
+ if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
+ return NULL;
+
+ if (__netlink_create(net, sock, cb_mutex, unit, 1) < 0)
+ goto out_sock_release_nosk;
+
+ sk = sock->sk;
+
+ if (!cfg || cfg->groups < 32)
+ groups = 32;
+ else
+ groups = cfg->groups;
+
+ listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
+ if (!listeners)
+ goto out_sock_release;
+
+ sk->sk_data_ready = netlink_data_ready;
+ if (cfg && cfg->input)
+ nlk_sk(sk)->netlink_rcv = cfg->input;
+
+ if (netlink_insert(sk, 0))
+ goto out_sock_release;
+
+ nlk = nlk_sk(sk);
+ nlk->flags |= NETLINK_F_KERNEL_SOCKET;
+
+ netlink_table_grab();
+ if (!nl_table[unit].registered) {
+ nl_table[unit].groups = groups;
+ rcu_assign_pointer(nl_table[unit].listeners, listeners);
+ nl_table[unit].cb_mutex = cb_mutex;
+ nl_table[unit].module = module;
+ if (cfg) {
+ nl_table[unit].bind = cfg->bind;
+ nl_table[unit].unbind = cfg->unbind;
+ nl_table[unit].flags = cfg->flags;
+ if (cfg->compare)
+ nl_table[unit].compare = cfg->compare;
+ }
+ 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)
+{
+ if (sk == NULL || sk->sk_socket == NULL)
+ return;
+
+ sock_release(sk->sk_socket);
+}
+EXPORT_SYMBOL(netlink_kernel_release);
+
+int __netlink_change_ngroups(struct sock *sk, unsigned int groups)
+{
+ struct listeners *new, *old;
+ struct netlink_table *tbl = &nl_table[sk->sk_protocol];
+
+ if (groups < 32)
+ groups = 32;
+
+ if (NLGRPSZ(tbl->groups) < NLGRPSZ(groups)) {
+ new = kzalloc(sizeof(*new) + NLGRPSZ(groups), GFP_ATOMIC);
+ if (!new)
+ return -ENOMEM;
+ old = nl_deref_protected(tbl->listeners);
+ memcpy(new->masks, old->masks, NLGRPSZ(tbl->groups));
+ rcu_assign_pointer(tbl->listeners, new);
+
+ kfree_rcu(old, rcu);
+ }
+ tbl->groups = groups;
+
+ return 0;
+}
+
+/**
+ * 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)
+{
+ int err;
+
+ netlink_table_grab();
+ err = __netlink_change_ngroups(sk, groups);
+ netlink_table_ungrab();
+
+ return err;
+}
+
+void __netlink_clear_multicast_users(struct sock *ksk, unsigned int group)
+{
+ struct sock *sk;
+ struct netlink_table *tbl = &nl_table[ksk->sk_protocol];
+
+ sk_for_each_bound(sk, &tbl->mc_list)
+ netlink_update_socket_mc(nlk_sk(sk), group, 0);
+}
+
+struct nlmsghdr *
+__nlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, int type, int len, int flags)
+{
+ struct nlmsghdr *nlh;
+ int size = nlmsg_msg_size(len);
+
+ nlh = skb_put(skb, NLMSG_ALIGN(size));
+ nlh->nlmsg_type = type;
+ nlh->nlmsg_len = size;
+ nlh->nlmsg_flags = flags;
+ nlh->nlmsg_pid = portid;
+ nlh->nlmsg_seq = seq;
+ if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0)
+ memset(nlmsg_data(nlh) + len, 0, NLMSG_ALIGN(size) - size);
+ return nlh;
+}
+EXPORT_SYMBOL(__nlmsg_put);
+
+/*
+ * 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 = NULL;
+ struct nlmsghdr *nlh;
+ struct module *module;
+ int err = -ENOBUFS;
+ int alloc_min_size;
+ int alloc_size;
+
+ mutex_lock(nlk->cb_mutex);
+ if (!nlk->cb_running) {
+ err = -EINVAL;
+ goto errout_skb;
+ }
+
+ if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf)
+ goto errout_skb;
+
+ /* NLMSG_GOODSIZE is small to avoid high order allocations being
+ * required, but it makes sense to _attempt_ a 16K bytes allocation
+ * to reduce number of system calls on dump operations, if user
+ * ever provided a big enough buffer.
+ */
+ cb = &nlk->cb;
+ alloc_min_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
+
+ if (alloc_min_size < nlk->max_recvmsg_len) {
+ alloc_size = nlk->max_recvmsg_len;
+ skb = alloc_skb(alloc_size,
+ (GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) |
+ __GFP_NOWARN | __GFP_NORETRY);
+ }
+ if (!skb) {
+ alloc_size = alloc_min_size;
+ skb = alloc_skb(alloc_size, GFP_KERNEL);
+ }
+ if (!skb)
+ goto errout_skb;
+
+ /* Trim skb to allocated size. User is expected to provide buffer as
+ * large as max(min_dump_alloc, 16KiB (mac_recvmsg_len capped at
+ * netlink_recvmsg())). dump will pack as many smaller messages as
+ * could fit within the allocated skb. skb is typically allocated
+ * with larger space than required (could be as much as near 2x the
+ * requested size with align to next power of 2 approach). Allowing
+ * dump to use the excess space makes it difficult for a user to have a
+ * reasonable static buffer based on the expected largest dump of a
+ * single netdev. The outcome is MSG_TRUNC error.
+ */
+ skb_reserve(skb, skb_tailroom(skb) - alloc_size);
+ netlink_skb_set_owner_r(skb, sk);
+
+ if (nlk->dump_done_errno > 0)
+ nlk->dump_done_errno = cb->dump(skb, cb);
+
+ if (nlk->dump_done_errno > 0 ||
+ skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) {
+ mutex_unlock(nlk->cb_mutex);
+
+ if (sk_filter(sk, skb))
+ kfree_skb(skb);
+ else
+ __netlink_sendskb(sk, skb);
+ return 0;
+ }
+
+ nlh = nlmsg_put_answer(skb, cb, NLMSG_DONE,
+ sizeof(nlk->dump_done_errno), NLM_F_MULTI);
+ if (WARN_ON(!nlh))
+ goto errout_skb;
+
+ nl_dump_check_consistent(cb, nlh);
+
+ memcpy(nlmsg_data(nlh), &nlk->dump_done_errno,
+ sizeof(nlk->dump_done_errno));
+
+ if (sk_filter(sk, skb))
+ kfree_skb(skb);
+ else
+ __netlink_sendskb(sk, skb);
+
+ if (cb->done)
+ cb->done(cb);
+
+ nlk->cb_running = false;
+ module = cb->module;
+ skb = cb->skb;
+ mutex_unlock(nlk->cb_mutex);
+ module_put(module);
+ consume_skb(skb);
+ return 0;
+
+errout_skb:
+ mutex_unlock(nlk->cb_mutex);
+ kfree_skb(skb);
+ return err;
+}
+
+int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb,
+ const struct nlmsghdr *nlh,
+ struct netlink_dump_control *control)
+{
+ struct netlink_callback *cb;
+ struct sock *sk;
+ struct netlink_sock *nlk;
+ int ret;
+
+ refcount_inc(&skb->users);
+
+ sk = netlink_lookup(sock_net(ssk), ssk->sk_protocol, NETLINK_CB(skb).portid);
+ if (sk == NULL) {
+ ret = -ECONNREFUSED;
+ goto error_free;
+ }
+
+ nlk = nlk_sk(sk);
+ mutex_lock(nlk->cb_mutex);
+ /* A dump is in progress... */
+ if (nlk->cb_running) {
+ ret = -EBUSY;
+ goto error_unlock;
+ }
+ /* add reference of module which cb->dump belongs to */
+ if (!try_module_get(control->module)) {
+ ret = -EPROTONOSUPPORT;
+ goto error_unlock;
+ }
+
+ cb = &nlk->cb;
+ memset(cb, 0, sizeof(*cb));
+ cb->dump = control->dump;
+ cb->done = control->done;
+ cb->nlh = nlh;
+ cb->data = control->data;
+ cb->module = control->module;
+ cb->min_dump_alloc = control->min_dump_alloc;
+ cb->skb = skb;
+
+ if (control->start) {
+ ret = control->start(cb);
+ if (ret)
+ goto error_put;
+ }
+
+ nlk->cb_running = true;
+ nlk->dump_done_errno = INT_MAX;
+
+ mutex_unlock(nlk->cb_mutex);
+
+ ret = netlink_dump(sk);
+
+ sock_put(sk);
+
+ if (ret)
+ return ret;
+
+ /* We successfully started a dump, by returning -EINTR we
+ * signal not to send ACK even if it was requested.
+ */
+ return -EINTR;
+
+error_put:
+ module_put(control->module);
+error_unlock:
+ sock_put(sk);
+ mutex_unlock(nlk->cb_mutex);
+error_free:
+ kfree_skb(skb);
+ return ret;
+}
+EXPORT_SYMBOL(__netlink_dump_start);
+
+void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err,
+ const struct netlink_ext_ack *extack)
+{
+ struct sk_buff *skb;
+ struct nlmsghdr *rep;
+ struct nlmsgerr *errmsg;
+ size_t payload = sizeof(*errmsg);
+ size_t tlvlen = 0;
+ struct netlink_sock *nlk = nlk_sk(NETLINK_CB(in_skb).sk);
+ unsigned int flags = 0;
+ bool nlk_has_extack = nlk->flags & NETLINK_F_EXT_ACK;
+
+ /* Error messages get the original request appened, unless the user
+ * requests to cap the error message, and get extra error data if
+ * requested.
+ */
+ if (nlk_has_extack && extack && extack->_msg)
+ tlvlen += nla_total_size(strlen(extack->_msg) + 1);
+
+ if (err) {
+ if (!(nlk->flags & NETLINK_F_CAP_ACK))
+ payload += nlmsg_len(nlh);
+ else
+ flags |= NLM_F_CAPPED;
+ if (nlk_has_extack && extack && extack->bad_attr)
+ tlvlen += nla_total_size(sizeof(u32));
+ } else {
+ flags |= NLM_F_CAPPED;
+
+ if (nlk_has_extack && extack && extack->cookie_len)
+ tlvlen += nla_total_size(extack->cookie_len);
+ }
+
+ if (tlvlen)
+ flags |= NLM_F_ACK_TLVS;
+
+ skb = nlmsg_new(payload + tlvlen, GFP_KERNEL);
+ if (!skb) {
+ NETLINK_CB(in_skb).sk->sk_err = ENOBUFS;
+ NETLINK_CB(in_skb).sk->sk_error_report(NETLINK_CB(in_skb).sk);
+ return;
+ }
+
+ rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
+ NLMSG_ERROR, payload, flags);
+ errmsg = nlmsg_data(rep);
+ errmsg->error = err;
+ memcpy(&errmsg->msg, nlh, payload > sizeof(*errmsg) ? nlh->nlmsg_len : sizeof(*nlh));
+
+ if (nlk_has_extack && extack) {
+ if (extack->_msg) {
+ WARN_ON(nla_put_string(skb, NLMSGERR_ATTR_MSG,
+ extack->_msg));
+ }
+ if (err) {
+ if (extack->bad_attr &&
+ !WARN_ON((u8 *)extack->bad_attr < in_skb->data ||
+ (u8 *)extack->bad_attr >= in_skb->data +
+ in_skb->len))
+ WARN_ON(nla_put_u32(skb, NLMSGERR_ATTR_OFFS,
+ (u8 *)extack->bad_attr -
+ in_skb->data));
+ } else {
+ if (extack->cookie_len)
+ WARN_ON(nla_put(skb, NLMSGERR_ATTR_COOKIE,
+ extack->cookie_len,
+ extack->cookie));
+ }
+ }
+
+ nlmsg_end(skb, rep);
+
+ netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT);
+}
+EXPORT_SYMBOL(netlink_ack);
+
+int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
+ struct nlmsghdr *,
+ struct netlink_ext_ack *))
+{
+ struct netlink_ext_ack extack;
+ struct nlmsghdr *nlh;
+ int err;
+
+ while (skb->len >= nlmsg_total_size(0)) {
+ int msglen;
+
+ memset(&extack, 0, sizeof(extack));
+ 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, &extack);
+ if (err == -EINTR)
+ goto skip;
+
+ack:
+ if (nlh->nlmsg_flags & NLM_F_ACK || err)
+ netlink_ack(skb, nlh, err, &extack);
+
+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
+ * @portid: destination netlink portid 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 portid,
+ unsigned int group, int report, gfp_t flags)
+{
+ int err = 0;
+
+ if (group) {
+ int exclude_portid = 0;
+
+ if (report) {
+ refcount_inc(&skb->users);
+ exclude_portid = portid;
+ }
+
+ /* errors reported via destination sk->sk_err, but propagate
+ * delivery errors if NETLINK_BROADCAST_ERROR flag is set */
+ err = nlmsg_multicast(sk, skb, exclude_portid, group, flags);
+ }
+
+ if (report) {
+ int err2;
+
+ err2 = nlmsg_unicast(sk, skb, portid);
+ if (!err || err == -ESRCH)
+ err = err2;
+ }
+
+ return err;
+}
+EXPORT_SYMBOL(nlmsg_notify);
+
+#ifdef CONFIG_PROC_FS
+struct nl_seq_iter {
+ struct seq_net_private p;
+ struct rhashtable_iter hti;
+ int link;
+};
+
+static int netlink_walk_start(struct nl_seq_iter *iter)
+{
+ int err;
+
+ err = rhashtable_walk_init(&nl_table[iter->link].hash, &iter->hti,
+ GFP_KERNEL);
+ if (err) {
+ iter->link = MAX_LINKS;
+ return err;
+ }
+
+ rhashtable_walk_start(&iter->hti);
+
+ return 0;
+}
+
+static void netlink_walk_stop(struct nl_seq_iter *iter)
+{
+ rhashtable_walk_stop(&iter->hti);
+ rhashtable_walk_exit(&iter->hti);
+}
+
+static void *__netlink_seq_next(struct seq_file *seq)
+{
+ struct nl_seq_iter *iter = seq->private;
+ struct netlink_sock *nlk;
+
+ do {
+ for (;;) {
+ int err;
+
+ nlk = rhashtable_walk_next(&iter->hti);
+
+ if (IS_ERR(nlk)) {
+ if (PTR_ERR(nlk) == -EAGAIN)
+ continue;
+
+ return nlk;
+ }
+
+ if (nlk)
+ break;
+
+ netlink_walk_stop(iter);
+ if (++iter->link >= MAX_LINKS)
+ return NULL;
+
+ err = netlink_walk_start(iter);
+ if (err)
+ return ERR_PTR(err);
+ }
+ } while (sock_net(&nlk->sk) != seq_file_net(seq));
+
+ return nlk;
+}
+
+static void *netlink_seq_start(struct seq_file *seq, loff_t *posp)
+{
+ struct nl_seq_iter *iter = seq->private;
+ void *obj = SEQ_START_TOKEN;
+ loff_t pos;
+ int err;
+
+ iter->link = 0;
+
+ err = netlink_walk_start(iter);
+ if (err)
+ return ERR_PTR(err);
+
+ for (pos = *posp; pos && obj && !IS_ERR(obj); pos--)
+ obj = __netlink_seq_next(seq);
+
+ return obj;
+}
+
+static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ ++*pos;
+ return __netlink_seq_next(seq);
+}
+
+static void netlink_seq_stop(struct seq_file *seq, void *v)
+{
+ struct nl_seq_iter *iter = seq->private;
+
+ if (iter->link >= MAX_LINKS)
+ return;
+
+ netlink_walk_stop(iter);
+}
+
+
+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 Drops Inode\n");
+ } else {
+ struct sock *s = v;
+ struct netlink_sock *nlk = nlk_sk(s);
+
+ seq_printf(seq, "%pK %-3d %-10u %08x %-8d %-8d %-5d %-8d %-8d %-8lu\n",
+ s,
+ s->sk_protocol,
+ nlk->portid,
+ nlk->groups ? (u32)nlk->groups[0] : 0,
+ sk_rmem_alloc_get(s),
+ sk_wmem_alloc_get(s),
+ nlk->cb_running,
+ refcount_read(&s->sk_refcnt),
+ atomic_read(&s->sk_drops),
+ sock_i_ino(s)
+ );
+
+ }
+ 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,
+};
+#endif
+
+int netlink_register_notifier(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_register(&netlink_chain, nb);
+}
+EXPORT_SYMBOL(netlink_register_notifier);
+
+int netlink_unregister_notifier(struct notifier_block *nb)
+{
+ return blocking_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 = netlink_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 const 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_create_net("netlink", 0, net->proc_net, &netlink_seq_ops,
+ sizeof(struct nl_seq_iter)))
+ return -ENOMEM;
+#endif
+ return 0;
+}
+
+static void __net_exit netlink_net_exit(struct net *net)
+{
+#ifdef CONFIG_PROC_FS
+ remove_proc_entry("netlink", net->proc_net);
+#endif
+}
+
+static void __init netlink_add_usersock_entry(void)
+{
+ struct listeners *listeners;
+ int groups = 32;
+
+ listeners = kzalloc(sizeof(*listeners) + NLGRPSZ(groups), GFP_KERNEL);
+ if (!listeners)
+ panic("netlink_add_usersock_entry: Cannot allocate listeners\n");
+
+ netlink_table_grab();
+
+ nl_table[NETLINK_USERSOCK].groups = groups;
+ rcu_assign_pointer(nl_table[NETLINK_USERSOCK].listeners, listeners);
+ nl_table[NETLINK_USERSOCK].module = THIS_MODULE;
+ nl_table[NETLINK_USERSOCK].registered = 1;
+ nl_table[NETLINK_USERSOCK].flags = NL_CFG_F_NONROOT_SEND;
+
+ netlink_table_ungrab();
+}
+
+static struct pernet_operations __net_initdata netlink_net_ops = {
+ .init = netlink_net_init,
+ .exit = netlink_net_exit,
+};
+
+static inline u32 netlink_hash(const void *data, u32 len, u32 seed)
+{
+ const struct netlink_sock *nlk = data;
+ struct netlink_compare_arg arg;
+
+ netlink_compare_arg_init(&arg, sock_net(&nlk->sk), nlk->portid);
+ return jhash2((u32 *)&arg, netlink_compare_arg_len / sizeof(u32), seed);
+}
+
+static const struct rhashtable_params netlink_rhashtable_params = {
+ .head_offset = offsetof(struct netlink_sock, node),
+ .key_len = netlink_compare_arg_len,
+ .obj_hashfn = netlink_hash,
+ .obj_cmpfn = netlink_compare,
+ .automatic_shrinking = true,
+};
+
+static int __init netlink_proto_init(void)
+{
+ int i;
+ int err = proto_register(&netlink_proto, 0);
+
+ if (err != 0)
+ goto out;
+
+ BUILD_BUG_ON(sizeof(struct netlink_skb_parms) > FIELD_SIZEOF(struct sk_buff, cb));
+
+ nl_table = kcalloc(MAX_LINKS, sizeof(*nl_table), GFP_KERNEL);
+ if (!nl_table)
+ goto panic;
+
+ for (i = 0; i < MAX_LINKS; i++) {
+ if (rhashtable_init(&nl_table[i].hash,
+ &netlink_rhashtable_params) < 0) {
+ while (--i > 0)
+ rhashtable_destroy(&nl_table[i].hash);
+ kfree(nl_table);
+ goto panic;
+ }
+ }
+
+ netlink_add_usersock_entry();
+
+ sock_register(&netlink_family_ops);
+ register_pernet_subsys(&netlink_net_ops);
+ register_pernet_subsys(&netlink_tap_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/af_netlink.h b/net/netlink/af_netlink.h
new file mode 100644
index 0000000..962de7b
--- /dev/null
+++ b/net/netlink/af_netlink.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _AF_NETLINK_H
+#define _AF_NETLINK_H
+
+#include <linux/rhashtable.h>
+#include <linux/atomic.h>
+#include <linux/workqueue.h>
+#include <net/sock.h>
+
+/* flags */
+#define NETLINK_F_KERNEL_SOCKET 0x1
+#define NETLINK_F_RECV_PKTINFO 0x2
+#define NETLINK_F_BROADCAST_SEND_ERROR 0x4
+#define NETLINK_F_RECV_NO_ENOBUFS 0x8
+#define NETLINK_F_LISTEN_ALL_NSID 0x10
+#define NETLINK_F_CAP_ACK 0x20
+#define NETLINK_F_EXT_ACK 0x40
+
+#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 portid;
+ u32 dst_portid;
+ u32 dst_group;
+ u32 flags;
+ u32 subscriptions;
+ u32 ngroups;
+ unsigned long *groups;
+ unsigned long state;
+ size_t max_recvmsg_len;
+ wait_queue_head_t wait;
+ bool bound;
+ bool cb_running;
+ int dump_done_errno;
+ struct netlink_callback cb;
+ struct mutex *cb_mutex;
+ struct mutex cb_def_mutex;
+ void (*netlink_rcv)(struct sk_buff *skb);
+ int (*netlink_bind)(struct net *net, int group);
+ void (*netlink_unbind)(struct net *net, int group);
+ struct module *module;
+
+ struct rhash_head node;
+ struct rcu_head rcu;
+ struct work_struct work;
+};
+
+static inline struct netlink_sock *nlk_sk(struct sock *sk)
+{
+ return container_of(sk, struct netlink_sock, sk);
+}
+
+struct netlink_table {
+ struct rhashtable hash;
+ struct hlist_head mc_list;
+ struct listeners __rcu *listeners;
+ unsigned int flags;
+ unsigned int groups;
+ struct mutex *cb_mutex;
+ struct module *module;
+ int (*bind)(struct net *net, int group);
+ void (*unbind)(struct net *net, int group);
+ bool (*compare)(struct net *net, struct sock *sock);
+ int registered;
+};
+
+extern struct netlink_table *nl_table;
+extern rwlock_t nl_table_lock;
+
+#endif
diff --git a/net/netlink/diag.c b/net/netlink/diag.c
new file mode 100644
index 0000000..7dda33b
--- /dev/null
+++ b/net/netlink/diag.c
@@ -0,0 +1,259 @@
+#include <linux/module.h>
+
+#include <net/sock.h>
+#include <linux/netlink.h>
+#include <linux/sock_diag.h>
+#include <linux/netlink_diag.h>
+#include <linux/rhashtable.h>
+
+#include "af_netlink.h"
+
+static int sk_diag_dump_groups(struct sock *sk, struct sk_buff *nlskb)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ if (nlk->groups == NULL)
+ return 0;
+
+ return nla_put(nlskb, NETLINK_DIAG_GROUPS, NLGRPSZ(nlk->ngroups),
+ nlk->groups);
+}
+
+static int sk_diag_put_flags(struct sock *sk, struct sk_buff *skb)
+{
+ struct netlink_sock *nlk = nlk_sk(sk);
+ u32 flags = 0;
+
+ if (nlk->cb_running)
+ flags |= NDIAG_FLAG_CB_RUNNING;
+ if (nlk->flags & NETLINK_F_RECV_PKTINFO)
+ flags |= NDIAG_FLAG_PKTINFO;
+ if (nlk->flags & NETLINK_F_BROADCAST_SEND_ERROR)
+ flags |= NDIAG_FLAG_BROADCAST_ERROR;
+ if (nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)
+ flags |= NDIAG_FLAG_NO_ENOBUFS;
+ if (nlk->flags & NETLINK_F_LISTEN_ALL_NSID)
+ flags |= NDIAG_FLAG_LISTEN_ALL_NSID;
+ if (nlk->flags & NETLINK_F_CAP_ACK)
+ flags |= NDIAG_FLAG_CAP_ACK;
+
+ return nla_put_u32(skb, NETLINK_DIAG_FLAGS, flags);
+}
+
+static int sk_diag_fill(struct sock *sk, struct sk_buff *skb,
+ struct netlink_diag_req *req,
+ u32 portid, u32 seq, u32 flags, int sk_ino)
+{
+ struct nlmsghdr *nlh;
+ struct netlink_diag_msg *rep;
+ struct netlink_sock *nlk = nlk_sk(sk);
+
+ nlh = nlmsg_put(skb, portid, seq, SOCK_DIAG_BY_FAMILY, sizeof(*rep),
+ flags);
+ if (!nlh)
+ return -EMSGSIZE;
+
+ rep = nlmsg_data(nlh);
+ rep->ndiag_family = AF_NETLINK;
+ rep->ndiag_type = sk->sk_type;
+ rep->ndiag_protocol = sk->sk_protocol;
+ rep->ndiag_state = sk->sk_state;
+
+ rep->ndiag_ino = sk_ino;
+ rep->ndiag_portid = nlk->portid;
+ rep->ndiag_dst_portid = nlk->dst_portid;
+ rep->ndiag_dst_group = nlk->dst_group;
+ sock_diag_save_cookie(sk, rep->ndiag_cookie);
+
+ if ((req->ndiag_show & NDIAG_SHOW_GROUPS) &&
+ sk_diag_dump_groups(sk, skb))
+ goto out_nlmsg_trim;
+
+ if ((req->ndiag_show & NDIAG_SHOW_MEMINFO) &&
+ sock_diag_put_meminfo(sk, skb, NETLINK_DIAG_MEMINFO))
+ goto out_nlmsg_trim;
+
+ if ((req->ndiag_show & NDIAG_SHOW_FLAGS) &&
+ sk_diag_put_flags(sk, skb))
+ goto out_nlmsg_trim;
+
+ nlmsg_end(skb, nlh);
+ return 0;
+
+out_nlmsg_trim:
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
+}
+
+static int __netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
+ int protocol, int s_num)
+{
+ struct rhashtable_iter *hti = (void *)cb->args[2];
+ struct netlink_table *tbl = &nl_table[protocol];
+ struct net *net = sock_net(skb->sk);
+ struct netlink_diag_req *req;
+ struct netlink_sock *nlsk;
+ struct sock *sk;
+ int num = 2;
+ int ret = 0;
+
+ req = nlmsg_data(cb->nlh);
+
+ if (s_num > 1)
+ goto mc_list;
+
+ num--;
+
+ if (!hti) {
+ hti = kmalloc(sizeof(*hti), GFP_KERNEL);
+ if (!hti)
+ return -ENOMEM;
+
+ cb->args[2] = (long)hti;
+ }
+
+ if (!s_num)
+ rhashtable_walk_enter(&tbl->hash, hti);
+
+ rhashtable_walk_start(hti);
+
+ while ((nlsk = rhashtable_walk_next(hti))) {
+ if (IS_ERR(nlsk)) {
+ ret = PTR_ERR(nlsk);
+ if (ret == -EAGAIN) {
+ ret = 0;
+ continue;
+ }
+ break;
+ }
+
+ sk = (struct sock *)nlsk;
+
+ if (!net_eq(sock_net(sk), net))
+ continue;
+
+ if (sk_diag_fill(sk, skb, req,
+ NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq,
+ NLM_F_MULTI,
+ sock_i_ino(sk)) < 0) {
+ ret = 1;
+ break;
+ }
+ }
+
+ rhashtable_walk_stop(hti);
+
+ if (ret)
+ goto done;
+
+ rhashtable_walk_exit(hti);
+ num++;
+
+mc_list:
+ read_lock(&nl_table_lock);
+ sk_for_each_bound(sk, &tbl->mc_list) {
+ if (sk_hashed(sk))
+ continue;
+ if (!net_eq(sock_net(sk), net))
+ continue;
+ if (num < s_num) {
+ num++;
+ continue;
+ }
+
+ if (sk_diag_fill(sk, skb, req,
+ NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq,
+ NLM_F_MULTI,
+ sock_i_ino(sk)) < 0) {
+ ret = 1;
+ break;
+ }
+ num++;
+ }
+ read_unlock(&nl_table_lock);
+
+done:
+ cb->args[0] = num;
+
+ return ret;
+}
+
+static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct netlink_diag_req *req;
+ int s_num = cb->args[0];
+ int err = 0;
+
+ req = nlmsg_data(cb->nlh);
+
+ if (req->sdiag_protocol == NDIAG_PROTO_ALL) {
+ int i;
+
+ for (i = cb->args[1]; i < MAX_LINKS; i++) {
+ err = __netlink_diag_dump(skb, cb, i, s_num);
+ if (err)
+ break;
+ s_num = 0;
+ }
+ cb->args[1] = i;
+ } else {
+ if (req->sdiag_protocol >= MAX_LINKS)
+ return -ENOENT;
+
+ err = __netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num);
+ }
+
+ return err < 0 ? err : skb->len;
+}
+
+static int netlink_diag_dump_done(struct netlink_callback *cb)
+{
+ struct rhashtable_iter *hti = (void *)cb->args[2];
+
+ if (cb->args[0] == 1)
+ rhashtable_walk_exit(hti);
+
+ kfree(hti);
+
+ return 0;
+}
+
+static int netlink_diag_handler_dump(struct sk_buff *skb, struct nlmsghdr *h)
+{
+ int hdrlen = sizeof(struct netlink_diag_req);
+ struct net *net = sock_net(skb->sk);
+
+ if (nlmsg_len(h) < hdrlen)
+ return -EINVAL;
+
+ if (h->nlmsg_flags & NLM_F_DUMP) {
+ struct netlink_dump_control c = {
+ .dump = netlink_diag_dump,
+ .done = netlink_diag_dump_done,
+ };
+ return netlink_dump_start(net->diag_nlsk, skb, h, &c);
+ } else
+ return -EOPNOTSUPP;
+}
+
+static const struct sock_diag_handler netlink_diag_handler = {
+ .family = AF_NETLINK,
+ .dump = netlink_diag_handler_dump,
+};
+
+static int __init netlink_diag_init(void)
+{
+ return sock_diag_register(&netlink_diag_handler);
+}
+
+static void __exit netlink_diag_exit(void)
+{
+ sock_diag_unregister(&netlink_diag_handler);
+}
+
+module_init(netlink_diag_init);
+module_exit(netlink_diag_exit);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_SOCK_DIAG, 16 /* AF_NETLINK */);
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
new file mode 100644
index 0000000..25eeb6d
--- /dev/null
+++ b/net/netlink/genetlink.c
@@ -0,0 +1,1144 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 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/slab.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 <linux/rwsem.h>
+#include <linux/idr.h>
+#include <net/sock.h>
+#include <net/genetlink.h>
+
+static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
+static DECLARE_RWSEM(cb_lock);
+
+atomic_t genl_sk_destructing_cnt = ATOMIC_INIT(0);
+DECLARE_WAIT_QUEUE_HEAD(genl_sk_destructing_waitq);
+
+void genl_lock(void)
+{
+ mutex_lock(&genl_mutex);
+}
+EXPORT_SYMBOL(genl_lock);
+
+void genl_unlock(void)
+{
+ mutex_unlock(&genl_mutex);
+}
+EXPORT_SYMBOL(genl_unlock);
+
+#ifdef CONFIG_LOCKDEP
+bool lockdep_genl_is_held(void)
+{
+ return lockdep_is_held(&genl_mutex);
+}
+EXPORT_SYMBOL(lockdep_genl_is_held);
+#endif
+
+static void genl_lock_all(void)
+{
+ down_write(&cb_lock);
+ genl_lock();
+}
+
+static void genl_unlock_all(void)
+{
+ genl_unlock();
+ up_write(&cb_lock);
+}
+
+static DEFINE_IDR(genl_fam_idr);
+
+/*
+ * 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.
+ * Bit 1 is marked as already used since the drop-monitor code
+ * abuses the API and thinks it can statically use group 1.
+ * That group will typically conflict with other groups that
+ * any proper users use.
+ * Bit 16 is marked as used since it's used for generic netlink
+ * and the code no longer marks pre-reserved IDs as used.
+ * Bit 17 is marked as already used since the VFS quota code
+ * also abused this API and relied on family == group ID, we
+ * cater to that by giving it a static family and group ID.
+ * Bit 18 is marked as already used since the PMCRAID driver
+ * did the same thing as the VFS quota code (maybe copied?)
+ */
+static unsigned long mc_group_start = 0x3 | BIT(GENL_ID_CTRL) |
+ BIT(GENL_ID_VFS_DQUOT) |
+ BIT(GENL_ID_PMCRAID);
+static unsigned long *mc_groups = &mc_group_start;
+static unsigned long mc_groups_longs = 1;
+
+static int genl_ctrl_event(int event, const struct genl_family *family,
+ const struct genl_multicast_group *grp,
+ int grp_id);
+
+static const struct genl_family *genl_family_find_byid(unsigned int id)
+{
+ return idr_find(&genl_fam_idr, id);
+}
+
+static const struct genl_family *genl_family_find_byname(char *name)
+{
+ const struct genl_family *family;
+ unsigned int id;
+
+ idr_for_each_entry(&genl_fam_idr, family, id)
+ if (strcmp(family->name, name) == 0)
+ return family;
+
+ return NULL;
+}
+
+static const struct genl_ops *genl_get_cmd(u8 cmd,
+ const struct genl_family *family)
+{
+ int i;
+
+ for (i = 0; i < family->n_ops; i++)
+ if (family->ops[i].cmd == cmd)
+ return &family->ops[i];
+
+ return NULL;
+}
+
+static int genl_allocate_reserve_groups(int n_groups, int *first_id)
+{
+ unsigned long *new_groups;
+ int start = 0;
+ int i;
+ int id;
+ bool fits;
+
+ do {
+ if (start == 0)
+ id = find_first_zero_bit(mc_groups,
+ mc_groups_longs *
+ BITS_PER_LONG);
+ else
+ id = find_next_zero_bit(mc_groups,
+ mc_groups_longs * BITS_PER_LONG,
+ start);
+
+ fits = true;
+ for (i = id;
+ i < min_t(int, id + n_groups,
+ mc_groups_longs * BITS_PER_LONG);
+ i++) {
+ if (test_bit(i, mc_groups)) {
+ start = i;
+ fits = false;
+ break;
+ }
+ }
+
+ if (id + n_groups > mc_groups_longs * BITS_PER_LONG) {
+ unsigned long new_longs = mc_groups_longs +
+ BITS_TO_LONGS(n_groups);
+ size_t nlen = new_longs * sizeof(unsigned long);
+
+ if (mc_groups == &mc_group_start) {
+ new_groups = kzalloc(nlen, GFP_KERNEL);
+ if (!new_groups)
+ return -ENOMEM;
+ mc_groups = new_groups;
+ *mc_groups = mc_group_start;
+ } else {
+ new_groups = krealloc(mc_groups, nlen,
+ GFP_KERNEL);
+ if (!new_groups)
+ return -ENOMEM;
+ mc_groups = new_groups;
+ for (i = 0; i < BITS_TO_LONGS(n_groups); i++)
+ mc_groups[mc_groups_longs + i] = 0;
+ }
+ mc_groups_longs = new_longs;
+ }
+ } while (!fits);
+
+ for (i = id; i < id + n_groups; i++)
+ set_bit(i, mc_groups);
+ *first_id = id;
+ return 0;
+}
+
+static struct genl_family genl_ctrl;
+
+static int genl_validate_assign_mc_groups(struct genl_family *family)
+{
+ int first_id;
+ int n_groups = family->n_mcgrps;
+ int err = 0, i;
+ bool groups_allocated = false;
+
+ if (!n_groups)
+ return 0;
+
+ for (i = 0; i < n_groups; i++) {
+ const struct genl_multicast_group *grp = &family->mcgrps[i];
+
+ if (WARN_ON(grp->name[0] == '\0'))
+ return -EINVAL;
+ if (WARN_ON(memchr(grp->name, '\0', GENL_NAMSIZ) == NULL))
+ return -EINVAL;
+ }
+
+ /* special-case our own group and hacks */
+ if (family == &genl_ctrl) {
+ first_id = GENL_ID_CTRL;
+ BUG_ON(n_groups != 1);
+ } else if (strcmp(family->name, "NET_DM") == 0) {
+ first_id = 1;
+ BUG_ON(n_groups != 1);
+ } else if (family->id == GENL_ID_VFS_DQUOT) {
+ first_id = GENL_ID_VFS_DQUOT;
+ BUG_ON(n_groups != 1);
+ } else if (family->id == GENL_ID_PMCRAID) {
+ first_id = GENL_ID_PMCRAID;
+ BUG_ON(n_groups != 1);
+ } else {
+ groups_allocated = true;
+ err = genl_allocate_reserve_groups(n_groups, &first_id);
+ if (err)
+ return err;
+ }
+
+ family->mcgrp_offset = first_id;
+
+ /* if still initializing, can't and don't need to to realloc bitmaps */
+ if (!init_net.genl_sock)
+ return 0;
+
+ if (family->netnsok) {
+ struct net *net;
+
+ netlink_table_grab();
+ rcu_read_lock();
+ for_each_net_rcu(net) {
+ err = __netlink_change_ngroups(net->genl_sock,
+ mc_groups_longs * BITS_PER_LONG);
+ if (err) {
+ /*
+ * No need to roll back, can only fail if
+ * memory allocation fails and then the
+ * number of _possible_ groups has been
+ * increased on some sockets which is ok.
+ */
+ break;
+ }
+ }
+ rcu_read_unlock();
+ netlink_table_ungrab();
+ } else {
+ err = netlink_change_ngroups(init_net.genl_sock,
+ mc_groups_longs * BITS_PER_LONG);
+ }
+
+ if (groups_allocated && err) {
+ for (i = 0; i < family->n_mcgrps; i++)
+ clear_bit(family->mcgrp_offset + i, mc_groups);
+ }
+
+ return err;
+}
+
+static void genl_unregister_mc_groups(const struct genl_family *family)
+{
+ struct net *net;
+ int i;
+
+ netlink_table_grab();
+ rcu_read_lock();
+ for_each_net_rcu(net) {
+ for (i = 0; i < family->n_mcgrps; i++)
+ __netlink_clear_multicast_users(
+ net->genl_sock, family->mcgrp_offset + i);
+ }
+ rcu_read_unlock();
+ netlink_table_ungrab();
+
+ for (i = 0; i < family->n_mcgrps; i++) {
+ int grp_id = family->mcgrp_offset + i;
+
+ if (grp_id != 1)
+ clear_bit(grp_id, mc_groups);
+ genl_ctrl_event(CTRL_CMD_DELMCAST_GRP, family,
+ &family->mcgrps[i], grp_id);
+ }
+}
+
+static int genl_validate_ops(const struct genl_family *family)
+{
+ const struct genl_ops *ops = family->ops;
+ unsigned int n_ops = family->n_ops;
+ int i, j;
+
+ if (WARN_ON(n_ops && !ops))
+ return -EINVAL;
+
+ if (!n_ops)
+ return 0;
+
+ for (i = 0; i < n_ops; i++) {
+ if (ops[i].dumpit == NULL && ops[i].doit == NULL)
+ return -EINVAL;
+ for (j = i + 1; j < n_ops; j++)
+ if (ops[i].cmd == ops[j].cmd)
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * 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's ops, multicast groups and module pointer must already
+ * be assigned.
+ *
+ * Return 0 on success or a negative error code.
+ */
+int genl_register_family(struct genl_family *family)
+{
+ int err, i;
+ int start = GENL_START_ALLOC, end = GENL_MAX_ID;
+
+ err = genl_validate_ops(family);
+ if (err)
+ return err;
+
+ genl_lock_all();
+
+ if (genl_family_find_byname(family->name)) {
+ err = -EEXIST;
+ goto errout_locked;
+ }
+
+ /*
+ * Sadly, a few cases need to be special-cased
+ * due to them having previously abused the API
+ * and having used their family ID also as their
+ * multicast group ID, so we use reserved IDs
+ * for both to be sure we can do that mapping.
+ */
+ if (family == &genl_ctrl) {
+ /* and this needs to be special for initial family lookups */
+ start = end = GENL_ID_CTRL;
+ } else if (strcmp(family->name, "pmcraid") == 0) {
+ start = end = GENL_ID_PMCRAID;
+ } else if (strcmp(family->name, "VFS_DQUOT") == 0) {
+ start = end = GENL_ID_VFS_DQUOT;
+ }
+
+ if (family->maxattr && !family->parallel_ops) {
+ family->attrbuf = kmalloc_array(family->maxattr + 1,
+ sizeof(struct nlattr *),
+ GFP_KERNEL);
+ if (family->attrbuf == NULL) {
+ err = -ENOMEM;
+ goto errout_locked;
+ }
+ } else
+ family->attrbuf = NULL;
+
+ family->id = idr_alloc(&genl_fam_idr, family,
+ start, end + 1, GFP_KERNEL);
+ if (family->id < 0) {
+ err = family->id;
+ goto errout_locked;
+ }
+
+ err = genl_validate_assign_mc_groups(family);
+ if (err)
+ goto errout_remove;
+
+ genl_unlock_all();
+
+ /* send all events */
+ genl_ctrl_event(CTRL_CMD_NEWFAMILY, family, NULL, 0);
+ for (i = 0; i < family->n_mcgrps; i++)
+ genl_ctrl_event(CTRL_CMD_NEWMCAST_GRP, family,
+ &family->mcgrps[i], family->mcgrp_offset + i);
+
+ return 0;
+
+errout_remove:
+ idr_remove(&genl_fam_idr, family->id);
+ kfree(family->attrbuf);
+errout_locked:
+ genl_unlock_all();
+ return err;
+}
+EXPORT_SYMBOL(genl_register_family);
+
+/**
+ * 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(const struct genl_family *family)
+{
+ genl_lock_all();
+
+ if (!genl_family_find_byid(family->id)) {
+ genl_unlock_all();
+ return -ENOENT;
+ }
+
+ genl_unregister_mc_groups(family);
+
+ idr_remove(&genl_fam_idr, family->id);
+
+ up_write(&cb_lock);
+ wait_event(genl_sk_destructing_waitq,
+ atomic_read(&genl_sk_destructing_cnt) == 0);
+ genl_unlock();
+
+ kfree(family->attrbuf);
+
+ genl_ctrl_event(CTRL_CMD_DELFAMILY, family, NULL, 0);
+
+ return 0;
+}
+EXPORT_SYMBOL(genl_unregister_family);
+
+/**
+ * genlmsg_put - Add generic netlink header to netlink message
+ * @skb: socket buffer holding the message
+ * @portid: netlink portid the message is addressed to
+ * @seq: sequence number (usually the one of the sender)
+ * @family: generic netlink family
+ * @flags: netlink message flags
+ * @cmd: generic netlink command
+ *
+ * Returns pointer to user specific header
+ */
+void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
+ const struct genl_family *family, int flags, u8 cmd)
+{
+ struct nlmsghdr *nlh;
+ struct genlmsghdr *hdr;
+
+ nlh = nlmsg_put(skb, portid, seq, family->id, GENL_HDRLEN +
+ family->hdrsize, flags);
+ if (nlh == NULL)
+ return NULL;
+
+ hdr = nlmsg_data(nlh);
+ hdr->cmd = cmd;
+ hdr->version = family->version;
+ hdr->reserved = 0;
+
+ return (char *) hdr + GENL_HDRLEN;
+}
+EXPORT_SYMBOL(genlmsg_put);
+
+static int genl_lock_start(struct netlink_callback *cb)
+{
+ /* our ops are always const - netlink API doesn't propagate that */
+ const struct genl_ops *ops = cb->data;
+ int rc = 0;
+
+ if (ops->start) {
+ genl_lock();
+ rc = ops->start(cb);
+ genl_unlock();
+ }
+ return rc;
+}
+
+static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ /* our ops are always const - netlink API doesn't propagate that */
+ const struct genl_ops *ops = cb->data;
+ int rc;
+
+ genl_lock();
+ rc = ops->dumpit(skb, cb);
+ genl_unlock();
+ return rc;
+}
+
+static int genl_lock_done(struct netlink_callback *cb)
+{
+ /* our ops are always const - netlink API doesn't propagate that */
+ const struct genl_ops *ops = cb->data;
+ int rc = 0;
+
+ if (ops->done) {
+ genl_lock();
+ rc = ops->done(cb);
+ genl_unlock();
+ }
+ return rc;
+}
+
+static int genl_family_rcv_msg(const struct genl_family *family,
+ struct sk_buff *skb,
+ struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
+{
+ const struct genl_ops *ops;
+ struct net *net = sock_net(skb->sk);
+ struct genl_info info;
+ struct genlmsghdr *hdr = nlmsg_data(nlh);
+ struct nlattr **attrbuf;
+ int hdrlen, err;
+
+ /* this family doesn't exist in this netns */
+ if (!family->netnsok && !net_eq(net, &init_net))
+ 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) &&
+ !netlink_capable(skb, CAP_NET_ADMIN))
+ return -EPERM;
+
+ if ((ops->flags & GENL_UNS_ADMIN_PERM) &&
+ !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
+ return -EPERM;
+
+ if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {
+ int rc;
+
+ if (ops->dumpit == NULL)
+ return -EOPNOTSUPP;
+
+ if (!family->parallel_ops) {
+ struct netlink_dump_control c = {
+ .module = family->module,
+ /* we have const, but the netlink API doesn't */
+ .data = (void *)ops,
+ .start = genl_lock_start,
+ .dump = genl_lock_dumpit,
+ .done = genl_lock_done,
+ };
+
+ genl_unlock();
+ rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
+ genl_lock();
+
+ } else {
+ struct netlink_dump_control c = {
+ .module = family->module,
+ .start = ops->start,
+ .dump = ops->dumpit,
+ .done = ops->done,
+ };
+
+ rc = __netlink_dump_start(net->genl_sock, skb, nlh, &c);
+ }
+
+ return rc;
+ }
+
+ if (ops->doit == NULL)
+ return -EOPNOTSUPP;
+
+ if (family->maxattr && family->parallel_ops) {
+ attrbuf = kmalloc_array(family->maxattr + 1,
+ sizeof(struct nlattr *),
+ GFP_KERNEL);
+ if (attrbuf == NULL)
+ return -ENOMEM;
+ } else
+ attrbuf = family->attrbuf;
+
+ if (attrbuf) {
+ err = nlmsg_parse(nlh, hdrlen, attrbuf, family->maxattr,
+ ops->policy, extack);
+ if (err < 0)
+ goto out;
+ }
+
+ info.snd_seq = nlh->nlmsg_seq;
+ info.snd_portid = NETLINK_CB(skb).portid;
+ info.nlhdr = nlh;
+ info.genlhdr = nlmsg_data(nlh);
+ info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
+ info.attrs = attrbuf;
+ info.extack = extack;
+ genl_info_net_set(&info, net);
+ memset(&info.user_ptr, 0, sizeof(info.user_ptr));
+
+ if (family->pre_doit) {
+ err = family->pre_doit(ops, skb, &info);
+ if (err)
+ goto out;
+ }
+
+ err = ops->doit(skb, &info);
+
+ if (family->post_doit)
+ family->post_doit(ops, skb, &info);
+
+out:
+ if (family->parallel_ops)
+ kfree(attrbuf);
+
+ return err;
+}
+
+static int genl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
+{
+ const struct genl_family *family;
+ int err;
+
+ family = genl_family_find_byid(nlh->nlmsg_type);
+ if (family == NULL)
+ return -ENOENT;
+
+ if (!family->parallel_ops)
+ genl_lock();
+
+ err = genl_family_rcv_msg(family, skb, nlh, extack);
+
+ if (!family->parallel_ops)
+ genl_unlock();
+
+ return err;
+}
+
+static void genl_rcv(struct sk_buff *skb)
+{
+ down_read(&cb_lock);
+ netlink_rcv_skb(skb, &genl_rcv_msg);
+ up_read(&cb_lock);
+}
+
+/**************************************************************************
+ * Controller
+ **************************************************************************/
+
+static struct genl_family genl_ctrl;
+
+static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq,
+ u32 flags, struct sk_buff *skb, u8 cmd)
+{
+ void *hdr;
+
+ hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
+ if (hdr == NULL)
+ return -1;
+
+ if (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))
+ goto nla_put_failure;
+
+ if (family->n_ops) {
+ struct nlattr *nla_ops;
+ int i;
+
+ nla_ops = nla_nest_start(skb, CTRL_ATTR_OPS);
+ if (nla_ops == NULL)
+ goto nla_put_failure;
+
+ for (i = 0; i < family->n_ops; i++) {
+ struct nlattr *nest;
+ const struct genl_ops *ops = &family->ops[i];
+ u32 op_flags = ops->flags;
+
+ if (ops->dumpit)
+ op_flags |= GENL_CMD_CAP_DUMP;
+ if (ops->doit)
+ op_flags |= GENL_CMD_CAP_DO;
+ if (ops->policy)
+ op_flags |= GENL_CMD_CAP_HASPOL;
+
+ nest = nla_nest_start(skb, i + 1);
+ if (nest == NULL)
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, CTRL_ATTR_OP_ID, ops->cmd) ||
+ nla_put_u32(skb, CTRL_ATTR_OP_FLAGS, op_flags))
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest);
+ }
+
+ nla_nest_end(skb, nla_ops);
+ }
+
+ if (family->n_mcgrps) {
+ struct nlattr *nla_grps;
+ int i;
+
+ nla_grps = nla_nest_start(skb, CTRL_ATTR_MCAST_GROUPS);
+ if (nla_grps == NULL)
+ goto nla_put_failure;
+
+ for (i = 0; i < family->n_mcgrps; i++) {
+ struct nlattr *nest;
+ const struct genl_multicast_group *grp;
+
+ grp = &family->mcgrps[i];
+
+ nest = nla_nest_start(skb, i + 1);
+ if (nest == NULL)
+ goto nla_put_failure;
+
+ if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID,
+ family->mcgrp_offset + i) ||
+ nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
+ grp->name))
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest);
+ }
+ nla_nest_end(skb, nla_grps);
+ }
+
+ genlmsg_end(skb, hdr);
+ return 0;
+
+nla_put_failure:
+ genlmsg_cancel(skb, hdr);
+ return -EMSGSIZE;
+}
+
+static int ctrl_fill_mcgrp_info(const struct genl_family *family,
+ const struct genl_multicast_group *grp,
+ int grp_id, u32 portid, u32 seq, u32 flags,
+ struct sk_buff *skb, u8 cmd)
+{
+ void *hdr;
+ struct nlattr *nla_grps;
+ struct nlattr *nest;
+
+ hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd);
+ if (hdr == NULL)
+ return -1;
+
+ if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) ||
+ nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id))
+ goto nla_put_failure;
+
+ 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;
+
+ if (nla_put_u32(skb, CTRL_ATTR_MCAST_GRP_ID, grp_id) ||
+ nla_put_string(skb, CTRL_ATTR_MCAST_GRP_NAME,
+ grp->name))
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest);
+ nla_nest_end(skb, nla_grps);
+
+ genlmsg_end(skb, hdr);
+ return 0;
+
+nla_put_failure:
+ genlmsg_cancel(skb, hdr);
+ return -EMSGSIZE;
+}
+
+static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ int n = 0;
+ struct genl_family *rt;
+ struct net *net = sock_net(skb->sk);
+ int fams_to_skip = cb->args[0];
+ unsigned int id;
+
+ idr_for_each_entry(&genl_fam_idr, rt, id) {
+ if (!rt->netnsok && !net_eq(net, &init_net))
+ continue;
+
+ if (n++ < fams_to_skip)
+ continue;
+
+ if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq, NLM_F_MULTI,
+ skb, CTRL_CMD_NEWFAMILY) < 0) {
+ n--;
+ break;
+ }
+ }
+
+ cb->args[0] = n;
+ return skb->len;
+}
+
+static struct sk_buff *ctrl_build_family_msg(const struct genl_family *family,
+ u32 portid, 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, portid, seq, 0, skb, cmd);
+ if (err < 0) {
+ nlmsg_free(skb);
+ return ERR_PTR(err);
+ }
+
+ return skb;
+}
+
+static struct sk_buff *
+ctrl_build_mcgrp_msg(const struct genl_family *family,
+ const struct genl_multicast_group *grp,
+ int grp_id, u32 portid, 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(family, grp, grp_id, portid,
+ 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;
+ const 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);
+ err = -ENOENT;
+ }
+
+ if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
+ char *name;
+
+ name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
+ res = genl_family_find_byname(name);
+#ifdef CONFIG_MODULES
+ if (res == NULL) {
+ genl_unlock();
+ up_read(&cb_lock);
+ request_module("net-pf-%d-proto-%d-family-%s",
+ PF_NETLINK, NETLINK_GENERIC, name);
+ down_read(&cb_lock);
+ genl_lock();
+ res = genl_family_find_byname(name);
+ }
+#endif
+ err = -ENOENT;
+ }
+
+ if (res == NULL)
+ return err;
+
+ if (!res->netnsok && !net_eq(genl_info_net(info), &init_net)) {
+ /* family doesn't exist here */
+ return -ENOENT;
+ }
+
+ msg = ctrl_build_family_msg(res, info->snd_portid, info->snd_seq,
+ CTRL_CMD_NEWFAMILY);
+ if (IS_ERR(msg))
+ return PTR_ERR(msg);
+
+ return genlmsg_reply(msg, info);
+}
+
+static int genl_ctrl_event(int event, const struct genl_family *family,
+ const struct genl_multicast_group *grp,
+ int grp_id)
+{
+ struct sk_buff *msg;
+
+ /* genl is still initialising */
+ if (!init_net.genl_sock)
+ return 0;
+
+ switch (event) {
+ case CTRL_CMD_NEWFAMILY:
+ case CTRL_CMD_DELFAMILY:
+ WARN_ON(grp);
+ msg = ctrl_build_family_msg(family, 0, 0, event);
+ break;
+ case CTRL_CMD_NEWMCAST_GRP:
+ case CTRL_CMD_DELMCAST_GRP:
+ BUG_ON(!grp);
+ msg = ctrl_build_mcgrp_msg(family, grp, grp_id, 0, 0, event);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (IS_ERR(msg))
+ return PTR_ERR(msg);
+
+ if (!family->netnsok) {
+ genlmsg_multicast_netns(&genl_ctrl, &init_net, msg, 0,
+ 0, GFP_KERNEL);
+ } else {
+ rcu_read_lock();
+ genlmsg_multicast_allns(&genl_ctrl, msg, 0,
+ 0, GFP_ATOMIC);
+ rcu_read_unlock();
+ }
+
+ return 0;
+}
+
+static const struct genl_ops genl_ctrl_ops[] = {
+ {
+ .cmd = CTRL_CMD_GETFAMILY,
+ .doit = ctrl_getfamily,
+ .dumpit = ctrl_dumpfamily,
+ .policy = ctrl_policy,
+ },
+};
+
+static const struct genl_multicast_group genl_ctrl_groups[] = {
+ { .name = "notify", },
+};
+
+static struct genl_family genl_ctrl __ro_after_init = {
+ .module = THIS_MODULE,
+ .ops = genl_ctrl_ops,
+ .n_ops = ARRAY_SIZE(genl_ctrl_ops),
+ .mcgrps = genl_ctrl_groups,
+ .n_mcgrps = ARRAY_SIZE(genl_ctrl_groups),
+ .id = GENL_ID_CTRL,
+ .name = "nlctrl",
+ .version = 0x2,
+ .maxattr = CTRL_ATTR_MAX,
+ .netnsok = true,
+};
+
+static int genl_bind(struct net *net, int group)
+{
+ struct genl_family *f;
+ int err = -ENOENT;
+ unsigned int id;
+
+ down_read(&cb_lock);
+
+ idr_for_each_entry(&genl_fam_idr, f, id) {
+ if (group >= f->mcgrp_offset &&
+ group < f->mcgrp_offset + f->n_mcgrps) {
+ int fam_grp = group - f->mcgrp_offset;
+
+ if (!f->netnsok && net != &init_net)
+ err = -ENOENT;
+ else if (f->mcast_bind)
+ err = f->mcast_bind(net, fam_grp);
+ else
+ err = 0;
+ break;
+ }
+ }
+ up_read(&cb_lock);
+
+ return err;
+}
+
+static void genl_unbind(struct net *net, int group)
+{
+ struct genl_family *f;
+ unsigned int id;
+
+ down_read(&cb_lock);
+
+ idr_for_each_entry(&genl_fam_idr, f, id) {
+ if (group >= f->mcgrp_offset &&
+ group < f->mcgrp_offset + f->n_mcgrps) {
+ int fam_grp = group - f->mcgrp_offset;
+
+ if (f->mcast_unbind)
+ f->mcast_unbind(net, fam_grp);
+ break;
+ }
+ }
+ up_read(&cb_lock);
+}
+
+static int __net_init genl_pernet_init(struct net *net)
+{
+ struct netlink_kernel_cfg cfg = {
+ .input = genl_rcv,
+ .flags = NL_CFG_F_NONROOT_RECV,
+ .bind = genl_bind,
+ .unbind = genl_unbind,
+ };
+
+ /* we'll bump the group number right afterwards */
+ net->genl_sock = netlink_kernel_create(net, NETLINK_GENERIC, &cfg);
+
+ if (!net->genl_sock && net_eq(net, &init_net))
+ panic("GENL: Cannot initialize generic netlink\n");
+
+ if (!net->genl_sock)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void __net_exit genl_pernet_exit(struct net *net)
+{
+ netlink_kernel_release(net->genl_sock);
+ net->genl_sock = NULL;
+}
+
+static struct pernet_operations genl_pernet_ops = {
+ .init = genl_pernet_init,
+ .exit = genl_pernet_exit,
+};
+
+static int __init genl_init(void)
+{
+ int err;
+
+ err = genl_register_family(&genl_ctrl);
+ if (err < 0)
+ goto problem;
+
+ err = register_pernet_subsys(&genl_pernet_ops);
+ if (err)
+ goto problem;
+
+ return 0;
+
+problem:
+ panic("GENL: Cannot register controller: %d\n", err);
+}
+
+subsys_initcall(genl_init);
+
+/**
+ * genl_family_attrbuf - return family's attrbuf
+ * @family: the family
+ *
+ * Return the family's attrbuf, while validating that it's
+ * actually valid to access it.
+ *
+ * You cannot use this function with a family that has parallel_ops
+ * and you can only use it within (pre/post) doit/dumpit callbacks.
+ */
+struct nlattr **genl_family_attrbuf(const struct genl_family *family)
+{
+ if (!WARN_ON(family->parallel_ops))
+ lockdep_assert_held(&genl_mutex);
+
+ return family->attrbuf;
+}
+EXPORT_SYMBOL(genl_family_attrbuf);
+
+static int genlmsg_mcast(struct sk_buff *skb, u32 portid, unsigned long group,
+ gfp_t flags)
+{
+ struct sk_buff *tmp;
+ struct net *net, *prev = NULL;
+ bool delivered = false;
+ int err;
+
+ for_each_net_rcu(net) {
+ if (prev) {
+ tmp = skb_clone(skb, flags);
+ if (!tmp) {
+ err = -ENOMEM;
+ goto error;
+ }
+ err = nlmsg_multicast(prev->genl_sock, tmp,
+ portid, group, flags);
+ if (!err)
+ delivered = true;
+ else if (err != -ESRCH)
+ goto error;
+ }
+
+ prev = net;
+ }
+
+ err = nlmsg_multicast(prev->genl_sock, skb, portid, group, flags);
+ if (!err)
+ delivered = true;
+ else if (err != -ESRCH)
+ return err;
+ return delivered ? 0 : -ESRCH;
+ error:
+ kfree_skb(skb);
+ return err;
+}
+
+int genlmsg_multicast_allns(const struct genl_family *family,
+ struct sk_buff *skb, u32 portid,
+ unsigned int group, gfp_t flags)
+{
+ if (WARN_ON_ONCE(group >= family->n_mcgrps))
+ return -EINVAL;
+ group = family->mcgrp_offset + group;
+ return genlmsg_mcast(skb, portid, group, flags);
+}
+EXPORT_SYMBOL(genlmsg_multicast_allns);
+
+void genl_notify(const struct genl_family *family, struct sk_buff *skb,
+ struct genl_info *info, u32 group, gfp_t flags)
+{
+ struct net *net = genl_info_net(info);
+ struct sock *sk = net->genl_sock;
+ int report = 0;
+
+ if (info->nlhdr)
+ report = nlmsg_report(info->nlhdr);
+
+ if (WARN_ON_ONCE(group >= family->n_mcgrps))
+ return;
+ group = family->mcgrp_offset + group;
+ nlmsg_notify(sk, skb, info->snd_portid, group, report, flags);
+}
+EXPORT_SYMBOL(genl_notify);