![David S. Miller](/assets/img/avatar_default.png)
Conflicts: drivers/net/ethernet/rocker/rocker.c The rocker commit was two overlapping changes, one to rename the ->vport member to ->pport, and another making the bitmask expression use '1ULL' instead of plain '1'. Signed-off-by: David S. Miller <davem@davemloft.net>
3162 lines
73 KiB
C
3162 lines
73 KiB
C
/*
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* NETLINK Kernel-user communication protocol.
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*
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* Authors: Alan Cox <alan@lxorguk.ukuu.org.uk>
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* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
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* Patrick McHardy <kaber@trash.net>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Tue Jun 26 14:36:48 MEST 2001 Herbert "herp" Rosmanith
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* added netlink_proto_exit
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* Tue Jan 22 18:32:44 BRST 2002 Arnaldo C. de Melo <acme@conectiva.com.br>
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* use nlk_sk, as sk->protinfo is on a diet 8)
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* Fri Jul 22 19:51:12 MEST 2005 Harald Welte <laforge@gnumonks.org>
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* - inc module use count of module that owns
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* the kernel socket in case userspace opens
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* socket of same protocol
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* - remove all module support, since netlink is
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* mandatory if CONFIG_NET=y these days
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*/
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#include <linux/module.h>
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#include <linux/capability.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/errno.h>
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#include <linux/string.h>
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#include <linux/stat.h>
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#include <linux/socket.h>
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#include <linux/un.h>
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#include <linux/fcntl.h>
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#include <linux/termios.h>
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#include <linux/sockios.h>
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#include <linux/net.h>
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#include <linux/fs.h>
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#include <linux/slab.h>
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#include <asm/uaccess.h>
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#include <linux/skbuff.h>
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#include <linux/netdevice.h>
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#include <linux/rtnetlink.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/notifier.h>
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#include <linux/security.h>
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#include <linux/jhash.h>
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#include <linux/jiffies.h>
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#include <linux/random.h>
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#include <linux/bitops.h>
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#include <linux/mm.h>
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#include <linux/types.h>
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#include <linux/audit.h>
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#include <linux/mutex.h>
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#include <linux/vmalloc.h>
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#include <linux/if_arp.h>
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#include <linux/rhashtable.h>
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#include <asm/cacheflush.h>
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#include <linux/hash.h>
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#include <linux/genetlink.h>
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#include <net/net_namespace.h>
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#include <net/sock.h>
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#include <net/scm.h>
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#include <net/netlink.h>
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#include "af_netlink.h"
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struct listeners {
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struct rcu_head rcu;
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unsigned long masks[0];
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};
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/* state bits */
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#define NETLINK_CONGESTED 0x0
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/* flags */
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#define NETLINK_KERNEL_SOCKET 0x1
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#define NETLINK_RECV_PKTINFO 0x2
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#define NETLINK_BROADCAST_SEND_ERROR 0x4
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#define NETLINK_RECV_NO_ENOBUFS 0x8
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static inline int netlink_is_kernel(struct sock *sk)
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{
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return nlk_sk(sk)->flags & NETLINK_KERNEL_SOCKET;
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}
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struct netlink_table *nl_table;
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EXPORT_SYMBOL_GPL(nl_table);
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static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
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static int netlink_dump(struct sock *sk);
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static void netlink_skb_destructor(struct sk_buff *skb);
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/* nl_table locking explained:
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* Lookup and traversal are protected with an RCU read-side lock. Insertion
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* and removal are protected with per bucket lock while using RCU list
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* modification primitives and may run in parallel to RCU protected lookups.
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* Destruction of the Netlink socket may only occur *after* nl_table_lock has
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* been acquired * either during or after the socket has been removed from
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* the list and after an RCU grace period.
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*/
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DEFINE_RWLOCK(nl_table_lock);
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EXPORT_SYMBOL_GPL(nl_table_lock);
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static atomic_t nl_table_users = ATOMIC_INIT(0);
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#define nl_deref_protected(X) rcu_dereference_protected(X, lockdep_is_held(&nl_table_lock));
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static ATOMIC_NOTIFIER_HEAD(netlink_chain);
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static DEFINE_SPINLOCK(netlink_tap_lock);
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static struct list_head netlink_tap_all __read_mostly;
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static inline u32 netlink_group_mask(u32 group)
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{
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return group ? 1 << (group - 1) : 0;
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}
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int netlink_add_tap(struct netlink_tap *nt)
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{
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if (unlikely(nt->dev->type != ARPHRD_NETLINK))
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return -EINVAL;
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spin_lock(&netlink_tap_lock);
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list_add_rcu(&nt->list, &netlink_tap_all);
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spin_unlock(&netlink_tap_lock);
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__module_get(nt->module);
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return 0;
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}
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EXPORT_SYMBOL_GPL(netlink_add_tap);
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static int __netlink_remove_tap(struct netlink_tap *nt)
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{
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bool found = false;
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struct netlink_tap *tmp;
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spin_lock(&netlink_tap_lock);
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list_for_each_entry(tmp, &netlink_tap_all, list) {
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if (nt == tmp) {
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list_del_rcu(&nt->list);
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found = true;
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goto out;
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}
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}
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pr_warn("__netlink_remove_tap: %p not found\n", nt);
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out:
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spin_unlock(&netlink_tap_lock);
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if (found && nt->module)
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module_put(nt->module);
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return found ? 0 : -ENODEV;
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}
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int netlink_remove_tap(struct netlink_tap *nt)
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{
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int ret;
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ret = __netlink_remove_tap(nt);
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synchronize_net();
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return ret;
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}
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EXPORT_SYMBOL_GPL(netlink_remove_tap);
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static bool netlink_filter_tap(const struct sk_buff *skb)
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{
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struct sock *sk = skb->sk;
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/* We take the more conservative approach and
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* whitelist socket protocols that may pass.
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*/
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switch (sk->sk_protocol) {
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case NETLINK_ROUTE:
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case NETLINK_USERSOCK:
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case NETLINK_SOCK_DIAG:
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case NETLINK_NFLOG:
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case NETLINK_XFRM:
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case NETLINK_FIB_LOOKUP:
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case NETLINK_NETFILTER:
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case NETLINK_GENERIC:
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return true;
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}
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return false;
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}
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static int __netlink_deliver_tap_skb(struct sk_buff *skb,
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struct net_device *dev)
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{
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struct sk_buff *nskb;
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struct sock *sk = skb->sk;
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int ret = -ENOMEM;
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dev_hold(dev);
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nskb = skb_clone(skb, GFP_ATOMIC);
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if (nskb) {
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nskb->dev = dev;
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nskb->protocol = htons((u16) sk->sk_protocol);
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nskb->pkt_type = netlink_is_kernel(sk) ?
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PACKET_KERNEL : PACKET_USER;
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skb_reset_network_header(nskb);
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ret = dev_queue_xmit(nskb);
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if (unlikely(ret > 0))
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ret = net_xmit_errno(ret);
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}
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dev_put(dev);
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return ret;
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}
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static void __netlink_deliver_tap(struct sk_buff *skb)
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{
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int ret;
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struct netlink_tap *tmp;
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if (!netlink_filter_tap(skb))
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return;
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list_for_each_entry_rcu(tmp, &netlink_tap_all, list) {
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ret = __netlink_deliver_tap_skb(skb, tmp->dev);
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if (unlikely(ret))
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break;
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}
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}
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static void netlink_deliver_tap(struct sk_buff *skb)
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{
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rcu_read_lock();
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if (unlikely(!list_empty(&netlink_tap_all)))
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__netlink_deliver_tap(skb);
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rcu_read_unlock();
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}
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static void netlink_deliver_tap_kernel(struct sock *dst, struct sock *src,
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struct sk_buff *skb)
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{
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if (!(netlink_is_kernel(dst) && netlink_is_kernel(src)))
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netlink_deliver_tap(skb);
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}
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static void netlink_overrun(struct sock *sk)
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{
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struct netlink_sock *nlk = nlk_sk(sk);
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if (!(nlk->flags & NETLINK_RECV_NO_ENOBUFS)) {
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if (!test_and_set_bit(NETLINK_CONGESTED, &nlk_sk(sk)->state)) {
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sk->sk_err = ENOBUFS;
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sk->sk_error_report(sk);
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}
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}
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atomic_inc(&sk->sk_drops);
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}
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static void netlink_rcv_wake(struct sock *sk)
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{
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struct netlink_sock *nlk = nlk_sk(sk);
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if (skb_queue_empty(&sk->sk_receive_queue))
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clear_bit(NETLINK_CONGESTED, &nlk->state);
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if (!test_bit(NETLINK_CONGESTED, &nlk->state))
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wake_up_interruptible(&nlk->wait);
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}
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#ifdef CONFIG_NETLINK_MMAP
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static bool netlink_skb_is_mmaped(const struct sk_buff *skb)
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{
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return NETLINK_CB(skb).flags & NETLINK_SKB_MMAPED;
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}
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static bool netlink_rx_is_mmaped(struct sock *sk)
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{
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return nlk_sk(sk)->rx_ring.pg_vec != NULL;
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}
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static bool netlink_tx_is_mmaped(struct sock *sk)
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{
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return nlk_sk(sk)->tx_ring.pg_vec != NULL;
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}
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static __pure struct page *pgvec_to_page(const void *addr)
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{
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if (is_vmalloc_addr(addr))
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return vmalloc_to_page(addr);
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else
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return virt_to_page(addr);
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}
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static void free_pg_vec(void **pg_vec, unsigned int order, unsigned int len)
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{
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unsigned int i;
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for (i = 0; i < len; i++) {
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if (pg_vec[i] != NULL) {
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if (is_vmalloc_addr(pg_vec[i]))
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vfree(pg_vec[i]);
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else
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free_pages((unsigned long)pg_vec[i], order);
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}
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}
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kfree(pg_vec);
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}
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static void *alloc_one_pg_vec_page(unsigned long order)
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{
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void *buffer;
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gfp_t gfp_flags = GFP_KERNEL | __GFP_COMP | __GFP_ZERO |
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__GFP_NOWARN | __GFP_NORETRY;
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buffer = (void *)__get_free_pages(gfp_flags, order);
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if (buffer != NULL)
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return buffer;
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buffer = vzalloc((1 << order) * PAGE_SIZE);
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if (buffer != NULL)
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return buffer;
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gfp_flags &= ~__GFP_NORETRY;
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return (void *)__get_free_pages(gfp_flags, order);
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}
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static void **alloc_pg_vec(struct netlink_sock *nlk,
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struct nl_mmap_req *req, unsigned int order)
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{
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unsigned int block_nr = req->nm_block_nr;
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unsigned int i;
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void **pg_vec;
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pg_vec = kcalloc(block_nr, sizeof(void *), GFP_KERNEL);
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if (pg_vec == NULL)
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return NULL;
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for (i = 0; i < block_nr; i++) {
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pg_vec[i] = alloc_one_pg_vec_page(order);
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if (pg_vec[i] == NULL)
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goto err1;
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}
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return pg_vec;
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err1:
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free_pg_vec(pg_vec, order, block_nr);
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return NULL;
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}
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static int netlink_set_ring(struct sock *sk, struct nl_mmap_req *req,
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bool closing, bool tx_ring)
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{
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struct netlink_sock *nlk = nlk_sk(sk);
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struct netlink_ring *ring;
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struct sk_buff_head *queue;
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void **pg_vec = NULL;
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unsigned int order = 0;
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int err;
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ring = tx_ring ? &nlk->tx_ring : &nlk->rx_ring;
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queue = tx_ring ? &sk->sk_write_queue : &sk->sk_receive_queue;
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if (!closing) {
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if (atomic_read(&nlk->mapped))
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return -EBUSY;
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if (atomic_read(&ring->pending))
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return -EBUSY;
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}
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if (req->nm_block_nr) {
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if (ring->pg_vec != NULL)
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return -EBUSY;
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if ((int)req->nm_block_size <= 0)
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return -EINVAL;
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if (!PAGE_ALIGNED(req->nm_block_size))
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return -EINVAL;
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if (req->nm_frame_size < NL_MMAP_HDRLEN)
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return -EINVAL;
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if (!IS_ALIGNED(req->nm_frame_size, NL_MMAP_MSG_ALIGNMENT))
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return -EINVAL;
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ring->frames_per_block = req->nm_block_size /
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req->nm_frame_size;
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if (ring->frames_per_block == 0)
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return -EINVAL;
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if (ring->frames_per_block * req->nm_block_nr !=
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req->nm_frame_nr)
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return -EINVAL;
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order = get_order(req->nm_block_size);
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pg_vec = alloc_pg_vec(nlk, req, order);
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if (pg_vec == NULL)
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return -ENOMEM;
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} else {
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if (req->nm_frame_nr)
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return -EINVAL;
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}
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err = -EBUSY;
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mutex_lock(&nlk->pg_vec_lock);
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if (closing || atomic_read(&nlk->mapped) == 0) {
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err = 0;
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spin_lock_bh(&queue->lock);
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ring->frame_max = req->nm_frame_nr - 1;
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ring->head = 0;
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ring->frame_size = req->nm_frame_size;
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ring->pg_vec_pages = req->nm_block_size / PAGE_SIZE;
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swap(ring->pg_vec_len, req->nm_block_nr);
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swap(ring->pg_vec_order, order);
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swap(ring->pg_vec, pg_vec);
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__skb_queue_purge(queue);
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spin_unlock_bh(&queue->lock);
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WARN_ON(atomic_read(&nlk->mapped));
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}
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mutex_unlock(&nlk->pg_vec_lock);
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if (pg_vec)
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free_pg_vec(pg_vec, order, req->nm_block_nr);
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return err;
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}
|
|
|
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static void netlink_mm_open(struct vm_area_struct *vma)
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{
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struct file *file = vma->vm_file;
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struct socket *sock = file->private_data;
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struct sock *sk = sock->sk;
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if (sk)
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atomic_inc(&nlk_sk(sk)->mapped);
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}
|
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|
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static void netlink_mm_close(struct vm_area_struct *vma)
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{
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struct file *file = vma->vm_file;
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struct socket *sock = file->private_data;
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struct sock *sk = sock->sk;
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if (sk)
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atomic_dec(&nlk_sk(sk)->mapped);
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}
|
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|
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static const struct vm_operations_struct netlink_mmap_ops = {
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.open = netlink_mm_open,
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.close = netlink_mm_close,
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};
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|
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static int netlink_mmap(struct file *file, struct socket *sock,
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struct vm_area_struct *vma)
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{
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struct sock *sk = sock->sk;
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struct netlink_sock *nlk = nlk_sk(sk);
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struct netlink_ring *ring;
|
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unsigned long start, size, expected;
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unsigned int i;
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int err = -EINVAL;
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|
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if (vma->vm_pgoff)
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return -EINVAL;
|
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|
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mutex_lock(&nlk->pg_vec_lock);
|
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|
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expected = 0;
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for (ring = &nlk->rx_ring; ring <= &nlk->tx_ring; ring++) {
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if (ring->pg_vec == NULL)
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continue;
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expected += ring->pg_vec_len * ring->pg_vec_pages * PAGE_SIZE;
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}
|
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|
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if (expected == 0)
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goto out;
|
|
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size = vma->vm_end - vma->vm_start;
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if (size != expected)
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goto out;
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start = vma->vm_start;
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for (ring = &nlk->rx_ring; ring <= &nlk->tx_ring; ring++) {
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if (ring->pg_vec == NULL)
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continue;
|
|
|
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for (i = 0; i < ring->pg_vec_len; i++) {
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struct page *page;
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void *kaddr = ring->pg_vec[i];
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unsigned int pg_num;
|
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|
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for (pg_num = 0; pg_num < ring->pg_vec_pages; pg_num++) {
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page = pgvec_to_page(kaddr);
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err = vm_insert_page(vma, start, page);
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if (err < 0)
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goto out;
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start += PAGE_SIZE;
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kaddr += PAGE_SIZE;
|
|
}
|
|
}
|
|
}
|
|
|
|
atomic_inc(&nlk->mapped);
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vma->vm_ops = &netlink_mmap_ops;
|
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err = 0;
|
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out:
|
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mutex_unlock(&nlk->pg_vec_lock);
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return err;
|
|
}
|
|
|
|
static void netlink_frame_flush_dcache(const struct nl_mmap_hdr *hdr, unsigned int nm_len)
|
|
{
|
|
#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 1
|
|
struct page *p_start, *p_end;
|
|
|
|
/* First page is flushed through netlink_{get,set}_status */
|
|
p_start = pgvec_to_page(hdr + PAGE_SIZE);
|
|
p_end = pgvec_to_page((void *)hdr + NL_MMAP_HDRLEN + nm_len - 1);
|
|
while (p_start <= p_end) {
|
|
flush_dcache_page(p_start);
|
|
p_start++;
|
|
}
|
|
#endif
|
|
}
|
|
|
|
static enum nl_mmap_status netlink_get_status(const struct nl_mmap_hdr *hdr)
|
|
{
|
|
smp_rmb();
|
|
flush_dcache_page(pgvec_to_page(hdr));
|
|
return hdr->nm_status;
|
|
}
|
|
|
|
static void netlink_set_status(struct nl_mmap_hdr *hdr,
|
|
enum nl_mmap_status status)
|
|
{
|
|
smp_mb();
|
|
hdr->nm_status = status;
|
|
flush_dcache_page(pgvec_to_page(hdr));
|
|
}
|
|
|
|
static struct nl_mmap_hdr *
|
|
__netlink_lookup_frame(const struct netlink_ring *ring, unsigned int pos)
|
|
{
|
|
unsigned int pg_vec_pos, frame_off;
|
|
|
|
pg_vec_pos = pos / ring->frames_per_block;
|
|
frame_off = pos % ring->frames_per_block;
|
|
|
|
return ring->pg_vec[pg_vec_pos] + (frame_off * ring->frame_size);
|
|
}
|
|
|
|
static struct nl_mmap_hdr *
|
|
netlink_lookup_frame(const struct netlink_ring *ring, unsigned int pos,
|
|
enum nl_mmap_status status)
|
|
{
|
|
struct nl_mmap_hdr *hdr;
|
|
|
|
hdr = __netlink_lookup_frame(ring, pos);
|
|
if (netlink_get_status(hdr) != status)
|
|
return NULL;
|
|
|
|
return hdr;
|
|
}
|
|
|
|
static struct nl_mmap_hdr *
|
|
netlink_current_frame(const struct netlink_ring *ring,
|
|
enum nl_mmap_status status)
|
|
{
|
|
return netlink_lookup_frame(ring, ring->head, status);
|
|
}
|
|
|
|
static struct nl_mmap_hdr *
|
|
netlink_previous_frame(const struct netlink_ring *ring,
|
|
enum nl_mmap_status status)
|
|
{
|
|
unsigned int prev;
|
|
|
|
prev = ring->head ? ring->head - 1 : ring->frame_max;
|
|
return netlink_lookup_frame(ring, prev, status);
|
|
}
|
|
|
|
static void netlink_increment_head(struct netlink_ring *ring)
|
|
{
|
|
ring->head = ring->head != ring->frame_max ? ring->head + 1 : 0;
|
|
}
|
|
|
|
static void netlink_forward_ring(struct netlink_ring *ring)
|
|
{
|
|
unsigned int head = ring->head, pos = head;
|
|
const struct nl_mmap_hdr *hdr;
|
|
|
|
do {
|
|
hdr = __netlink_lookup_frame(ring, pos);
|
|
if (hdr->nm_status == NL_MMAP_STATUS_UNUSED)
|
|
break;
|
|
if (hdr->nm_status != NL_MMAP_STATUS_SKIP)
|
|
break;
|
|
netlink_increment_head(ring);
|
|
} while (ring->head != head);
|
|
}
|
|
|
|
static bool netlink_dump_space(struct netlink_sock *nlk)
|
|
{
|
|
struct netlink_ring *ring = &nlk->rx_ring;
|
|
struct nl_mmap_hdr *hdr;
|
|
unsigned int n;
|
|
|
|
hdr = netlink_current_frame(ring, NL_MMAP_STATUS_UNUSED);
|
|
if (hdr == NULL)
|
|
return false;
|
|
|
|
n = ring->head + ring->frame_max / 2;
|
|
if (n > ring->frame_max)
|
|
n -= ring->frame_max;
|
|
|
|
hdr = __netlink_lookup_frame(ring, n);
|
|
|
|
return hdr->nm_status == NL_MMAP_STATUS_UNUSED;
|
|
}
|
|
|
|
static unsigned int netlink_poll(struct file *file, struct socket *sock,
|
|
poll_table *wait)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
unsigned int mask;
|
|
int err;
|
|
|
|
if (nlk->rx_ring.pg_vec != NULL) {
|
|
/* Memory mapped sockets don't call recvmsg(), so flow control
|
|
* for dumps is performed here. A dump is allowed to continue
|
|
* if at least half the ring is unused.
|
|
*/
|
|
while (nlk->cb_running && netlink_dump_space(nlk)) {
|
|
err = netlink_dump(sk);
|
|
if (err < 0) {
|
|
sk->sk_err = -err;
|
|
sk->sk_error_report(sk);
|
|
break;
|
|
}
|
|
}
|
|
netlink_rcv_wake(sk);
|
|
}
|
|
|
|
mask = datagram_poll(file, sock, wait);
|
|
|
|
spin_lock_bh(&sk->sk_receive_queue.lock);
|
|
if (nlk->rx_ring.pg_vec) {
|
|
netlink_forward_ring(&nlk->rx_ring);
|
|
if (!netlink_previous_frame(&nlk->rx_ring, NL_MMAP_STATUS_UNUSED))
|
|
mask |= POLLIN | POLLRDNORM;
|
|
}
|
|
spin_unlock_bh(&sk->sk_receive_queue.lock);
|
|
|
|
spin_lock_bh(&sk->sk_write_queue.lock);
|
|
if (nlk->tx_ring.pg_vec) {
|
|
if (netlink_current_frame(&nlk->tx_ring, NL_MMAP_STATUS_UNUSED))
|
|
mask |= POLLOUT | POLLWRNORM;
|
|
}
|
|
spin_unlock_bh(&sk->sk_write_queue.lock);
|
|
|
|
return mask;
|
|
}
|
|
|
|
static struct nl_mmap_hdr *netlink_mmap_hdr(struct sk_buff *skb)
|
|
{
|
|
return (struct nl_mmap_hdr *)(skb->head - NL_MMAP_HDRLEN);
|
|
}
|
|
|
|
static void netlink_ring_setup_skb(struct sk_buff *skb, struct sock *sk,
|
|
struct netlink_ring *ring,
|
|
struct nl_mmap_hdr *hdr)
|
|
{
|
|
unsigned int size;
|
|
void *data;
|
|
|
|
size = ring->frame_size - NL_MMAP_HDRLEN;
|
|
data = (void *)hdr + NL_MMAP_HDRLEN;
|
|
|
|
skb->head = data;
|
|
skb->data = data;
|
|
skb_reset_tail_pointer(skb);
|
|
skb->end = skb->tail + size;
|
|
skb->len = 0;
|
|
|
|
skb->destructor = netlink_skb_destructor;
|
|
NETLINK_CB(skb).flags |= NETLINK_SKB_MMAPED;
|
|
NETLINK_CB(skb).sk = sk;
|
|
}
|
|
|
|
static int netlink_mmap_sendmsg(struct sock *sk, struct msghdr *msg,
|
|
u32 dst_portid, u32 dst_group,
|
|
struct scm_cookie *scm)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
struct netlink_ring *ring;
|
|
struct nl_mmap_hdr *hdr;
|
|
struct sk_buff *skb;
|
|
unsigned int maxlen;
|
|
int err = 0, len = 0;
|
|
|
|
mutex_lock(&nlk->pg_vec_lock);
|
|
|
|
ring = &nlk->tx_ring;
|
|
maxlen = ring->frame_size - NL_MMAP_HDRLEN;
|
|
|
|
do {
|
|
unsigned int nm_len;
|
|
|
|
hdr = netlink_current_frame(ring, NL_MMAP_STATUS_VALID);
|
|
if (hdr == NULL) {
|
|
if (!(msg->msg_flags & MSG_DONTWAIT) &&
|
|
atomic_read(&nlk->tx_ring.pending))
|
|
schedule();
|
|
continue;
|
|
}
|
|
|
|
nm_len = ACCESS_ONCE(hdr->nm_len);
|
|
if (nm_len > maxlen) {
|
|
err = -EINVAL;
|
|
goto out;
|
|
}
|
|
|
|
netlink_frame_flush_dcache(hdr, nm_len);
|
|
|
|
skb = alloc_skb(nm_len, GFP_KERNEL);
|
|
if (skb == NULL) {
|
|
err = -ENOBUFS;
|
|
goto out;
|
|
}
|
|
__skb_put(skb, nm_len);
|
|
memcpy(skb->data, (void *)hdr + NL_MMAP_HDRLEN, nm_len);
|
|
netlink_set_status(hdr, NL_MMAP_STATUS_UNUSED);
|
|
|
|
netlink_increment_head(ring);
|
|
|
|
NETLINK_CB(skb).portid = nlk->portid;
|
|
NETLINK_CB(skb).dst_group = dst_group;
|
|
NETLINK_CB(skb).creds = scm->creds;
|
|
|
|
err = security_netlink_send(sk, skb);
|
|
if (err) {
|
|
kfree_skb(skb);
|
|
goto out;
|
|
}
|
|
|
|
if (unlikely(dst_group)) {
|
|
atomic_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);
|
|
if (err < 0)
|
|
goto out;
|
|
len += err;
|
|
|
|
} while (hdr != NULL ||
|
|
(!(msg->msg_flags & MSG_DONTWAIT) &&
|
|
atomic_read(&nlk->tx_ring.pending)));
|
|
|
|
if (len > 0)
|
|
err = len;
|
|
out:
|
|
mutex_unlock(&nlk->pg_vec_lock);
|
|
return err;
|
|
}
|
|
|
|
static void netlink_queue_mmaped_skb(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct nl_mmap_hdr *hdr;
|
|
|
|
hdr = netlink_mmap_hdr(skb);
|
|
hdr->nm_len = skb->len;
|
|
hdr->nm_group = NETLINK_CB(skb).dst_group;
|
|
hdr->nm_pid = NETLINK_CB(skb).creds.pid;
|
|
hdr->nm_uid = from_kuid(sk_user_ns(sk), NETLINK_CB(skb).creds.uid);
|
|
hdr->nm_gid = from_kgid(sk_user_ns(sk), NETLINK_CB(skb).creds.gid);
|
|
netlink_frame_flush_dcache(hdr, hdr->nm_len);
|
|
netlink_set_status(hdr, NL_MMAP_STATUS_VALID);
|
|
|
|
NETLINK_CB(skb).flags |= NETLINK_SKB_DELIVERED;
|
|
kfree_skb(skb);
|
|
}
|
|
|
|
static void netlink_ring_set_copied(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
struct netlink_ring *ring = &nlk->rx_ring;
|
|
struct nl_mmap_hdr *hdr;
|
|
|
|
spin_lock_bh(&sk->sk_receive_queue.lock);
|
|
hdr = netlink_current_frame(ring, NL_MMAP_STATUS_UNUSED);
|
|
if (hdr == NULL) {
|
|
spin_unlock_bh(&sk->sk_receive_queue.lock);
|
|
kfree_skb(skb);
|
|
netlink_overrun(sk);
|
|
return;
|
|
}
|
|
netlink_increment_head(ring);
|
|
__skb_queue_tail(&sk->sk_receive_queue, skb);
|
|
spin_unlock_bh(&sk->sk_receive_queue.lock);
|
|
|
|
hdr->nm_len = skb->len;
|
|
hdr->nm_group = NETLINK_CB(skb).dst_group;
|
|
hdr->nm_pid = NETLINK_CB(skb).creds.pid;
|
|
hdr->nm_uid = from_kuid(sk_user_ns(sk), NETLINK_CB(skb).creds.uid);
|
|
hdr->nm_gid = from_kgid(sk_user_ns(sk), NETLINK_CB(skb).creds.gid);
|
|
netlink_set_status(hdr, NL_MMAP_STATUS_COPY);
|
|
}
|
|
|
|
#else /* CONFIG_NETLINK_MMAP */
|
|
#define netlink_skb_is_mmaped(skb) false
|
|
#define netlink_rx_is_mmaped(sk) false
|
|
#define netlink_tx_is_mmaped(sk) false
|
|
#define netlink_mmap sock_no_mmap
|
|
#define netlink_poll datagram_poll
|
|
#define netlink_mmap_sendmsg(sk, msg, dst_portid, dst_group, scm) 0
|
|
#endif /* CONFIG_NETLINK_MMAP */
|
|
|
|
static void netlink_skb_destructor(struct sk_buff *skb)
|
|
{
|
|
#ifdef CONFIG_NETLINK_MMAP
|
|
struct nl_mmap_hdr *hdr;
|
|
struct netlink_ring *ring;
|
|
struct sock *sk;
|
|
|
|
/* If a packet from the kernel to userspace was freed because of an
|
|
* error without being delivered to userspace, the kernel must reset
|
|
* the status. In the direction userspace to kernel, the status is
|
|
* always reset here after the packet was processed and freed.
|
|
*/
|
|
if (netlink_skb_is_mmaped(skb)) {
|
|
hdr = netlink_mmap_hdr(skb);
|
|
sk = NETLINK_CB(skb).sk;
|
|
|
|
if (NETLINK_CB(skb).flags & NETLINK_SKB_TX) {
|
|
netlink_set_status(hdr, NL_MMAP_STATUS_UNUSED);
|
|
ring = &nlk_sk(sk)->tx_ring;
|
|
} else {
|
|
if (!(NETLINK_CB(skb).flags & NETLINK_SKB_DELIVERED)) {
|
|
hdr->nm_len = 0;
|
|
netlink_set_status(hdr, NL_MMAP_STATUS_VALID);
|
|
}
|
|
ring = &nlk_sk(sk)->rx_ring;
|
|
}
|
|
|
|
WARN_ON(atomic_read(&ring->pending) == 0);
|
|
atomic_dec(&ring->pending);
|
|
sock_put(sk);
|
|
|
|
skb->head = NULL;
|
|
}
|
|
#endif
|
|
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);
|
|
#ifdef CONFIG_NETLINK_MMAP
|
|
if (1) {
|
|
struct nl_mmap_req req;
|
|
|
|
memset(&req, 0, sizeof(req));
|
|
if (nlk->rx_ring.pg_vec)
|
|
netlink_set_ring(sk, &req, true, false);
|
|
memset(&req, 0, sizeof(req));
|
|
if (nlk->tx_ring.pg_vec)
|
|
netlink_set_ring(sk, &req, true, true);
|
|
}
|
|
#endif /* CONFIG_NETLINK_MMAP */
|
|
|
|
if (!sock_flag(sk, SOCK_DEAD)) {
|
|
printk(KERN_ERR "Freeing alive netlink socket %p\n", sk);
|
|
return;
|
|
}
|
|
|
|
WARN_ON(atomic_read(&sk->sk_rmem_alloc));
|
|
WARN_ON(atomic_read(&sk->sk_wmem_alloc));
|
|
WARN_ON(nlk_sk(sk)->groups);
|
|
}
|
|
|
|
/* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it is _very_ bad on
|
|
* SMP. Look, when several writers sleep and reader wakes them up, all but one
|
|
* immediately hit write lock and grab all the cpus. Exclusive sleep solves
|
|
* this, _but_ remember, it adds useless work on UP machines.
|
|
*/
|
|
|
|
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
|
|
{
|
|
struct net *net;
|
|
u32 portid;
|
|
};
|
|
|
|
static bool netlink_compare(void *ptr, void *arg)
|
|
{
|
|
struct netlink_compare_arg *x = arg;
|
|
struct sock *sk = ptr;
|
|
|
|
return nlk_sk(sk)->portid == x->portid &&
|
|
net_eq(sock_net(sk), x->net);
|
|
}
|
|
|
|
static struct sock *__netlink_lookup(struct netlink_table *table, u32 portid,
|
|
struct net *net)
|
|
{
|
|
struct netlink_compare_arg arg = {
|
|
.net = net,
|
|
.portid = portid,
|
|
};
|
|
|
|
return rhashtable_lookup_compare(&table->hash, &portid,
|
|
&netlink_compare, &arg);
|
|
}
|
|
|
|
static bool __netlink_insert(struct netlink_table *table, struct sock *sk)
|
|
{
|
|
struct netlink_compare_arg arg = {
|
|
.net = sock_net(sk),
|
|
.portid = nlk_sk(sk)->portid,
|
|
};
|
|
|
|
return rhashtable_lookup_compare_insert(&table->hash,
|
|
&nlk_sk(sk)->node,
|
|
&netlink_compare, &arg);
|
|
}
|
|
|
|
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 = -EBUSY;
|
|
if (nlk_sk(sk)->portid)
|
|
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 = 0;
|
|
if (!__netlink_insert(table, sk)) {
|
|
err = -EADDRINUSE;
|
|
sock_put(sk);
|
|
}
|
|
|
|
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(&table->hash, &nlk_sk(sk)->node)) {
|
|
WARN_ON(atomic_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)
|
|
{
|
|
struct sock *sk;
|
|
struct netlink_sock *nlk;
|
|
|
|
sock->ops = &netlink_ops;
|
|
|
|
sk = sk_alloc(net, PF_NETLINK, GFP_KERNEL, &netlink_proto);
|
|
if (!sk)
|
|
return -ENOMEM;
|
|
|
|
sock_init_data(sock, sk);
|
|
|
|
nlk = nlk_sk(sk);
|
|
if (cb_mutex) {
|
|
nlk->cb_mutex = cb_mutex;
|
|
} else {
|
|
nlk->cb_mutex = &nlk->cb_def_mutex;
|
|
mutex_init(nlk->cb_mutex);
|
|
}
|
|
init_waitqueue_head(&nlk->wait);
|
|
#ifdef CONFIG_NETLINK_MMAP
|
|
mutex_init(&nlk->pg_vec_lock);
|
|
#endif
|
|
|
|
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;
|
|
|
|
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);
|
|
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);
|
|
|
|
sock_put(&nlk->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) {
|
|
struct netlink_notify n = {
|
|
.net = sock_net(sk),
|
|
.protocol = sk->sk_protocol,
|
|
.portid = nlk->portid,
|
|
};
|
|
atomic_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();
|
|
}
|
|
|
|
kfree(nlk->groups);
|
|
nlk->groups = NULL;
|
|
|
|
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;
|
|
static s32 rover = -4097;
|
|
|
|
retry:
|
|
cond_resched();
|
|
rcu_read_lock();
|
|
if (__netlink_lookup(table, portid, net)) {
|
|
/* Bind collision, search negative portid values. */
|
|
portid = rover--;
|
|
if (rover > -4097)
|
|
rover = -4097;
|
|
rcu_read_unlock();
|
|
goto retry;
|
|
}
|
|
rcu_read_unlock();
|
|
|
|
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;
|
|
long unsigned int groups = nladdr->nl_groups;
|
|
|
|
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->portid)
|
|
if (nladdr->nl_pid != nlk->portid)
|
|
return -EINVAL;
|
|
|
|
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);
|
|
return err;
|
|
}
|
|
}
|
|
|
|
if (!nlk->portid) {
|
|
err = nladdr->nl_pid ?
|
|
netlink_insert(sk, nladdr->nl_pid) :
|
|
netlink_autobind(sock);
|
|
if (err) {
|
|
netlink_undo_bind(nlk->ngroups, groups, sk);
|
|
return err;
|
|
}
|
|
}
|
|
|
|
if (!groups && (nlk->groups == NULL || !(u32)nlk->groups[0]))
|
|
return 0;
|
|
|
|
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;
|
|
}
|
|
|
|
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 ((nladdr->nl_groups || nladdr->nl_pid) &&
|
|
!netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
|
|
return -EPERM;
|
|
|
|
if (!nlk->portid)
|
|
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 *addr_len, 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;
|
|
*addr_len = sizeof(*nladdr);
|
|
|
|
if (peer) {
|
|
nladdr->nl_pid = nlk->dst_portid;
|
|
nladdr->nl_groups = netlink_group_mask(nlk->dst_group);
|
|
} else {
|
|
nladdr->nl_pid = nlk->portid;
|
|
nladdr->nl_groups = nlk->groups ? nlk->groups[0] : 0;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
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->head_frag = 0;
|
|
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_CONGESTED, &nlk->state)) &&
|
|
!netlink_skb_is_mmaped(skb)) {
|
|
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_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(skb);
|
|
|
|
#ifdef CONFIG_NETLINK_MMAP
|
|
if (netlink_skb_is_mmaped(skb))
|
|
netlink_queue_mmaped_skb(sk, skb);
|
|
else if (netlink_rx_is_mmaped(sk))
|
|
netlink_ring_set_copied(sk, skb);
|
|
else
|
|
#endif /* CONFIG_NETLINK_MMAP */
|
|
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);
|
|
if (netlink_skb_is_mmaped(skb))
|
|
return skb;
|
|
|
|
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;
|
|
}
|
|
|
|
if (!pskb_expand_head(skb, 0, -delta, allocation))
|
|
skb->truesize -= delta;
|
|
|
|
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);
|
|
|
|
struct sk_buff *netlink_alloc_skb(struct sock *ssk, unsigned int size,
|
|
u32 dst_portid, gfp_t gfp_mask)
|
|
{
|
|
#ifdef CONFIG_NETLINK_MMAP
|
|
struct sock *sk = NULL;
|
|
struct sk_buff *skb;
|
|
struct netlink_ring *ring;
|
|
struct nl_mmap_hdr *hdr;
|
|
unsigned int maxlen;
|
|
|
|
sk = netlink_getsockbyportid(ssk, dst_portid);
|
|
if (IS_ERR(sk))
|
|
goto out;
|
|
|
|
ring = &nlk_sk(sk)->rx_ring;
|
|
/* fast-path without atomic ops for common case: non-mmaped receiver */
|
|
if (ring->pg_vec == NULL)
|
|
goto out_put;
|
|
|
|
if (ring->frame_size - NL_MMAP_HDRLEN < size)
|
|
goto out_put;
|
|
|
|
skb = alloc_skb_head(gfp_mask);
|
|
if (skb == NULL)
|
|
goto err1;
|
|
|
|
spin_lock_bh(&sk->sk_receive_queue.lock);
|
|
/* check again under lock */
|
|
if (ring->pg_vec == NULL)
|
|
goto out_free;
|
|
|
|
/* check again under lock */
|
|
maxlen = ring->frame_size - NL_MMAP_HDRLEN;
|
|
if (maxlen < size)
|
|
goto out_free;
|
|
|
|
netlink_forward_ring(ring);
|
|
hdr = netlink_current_frame(ring, NL_MMAP_STATUS_UNUSED);
|
|
if (hdr == NULL)
|
|
goto err2;
|
|
netlink_ring_setup_skb(skb, sk, ring, hdr);
|
|
netlink_set_status(hdr, NL_MMAP_STATUS_RESERVED);
|
|
atomic_inc(&ring->pending);
|
|
netlink_increment_head(ring);
|
|
|
|
spin_unlock_bh(&sk->sk_receive_queue.lock);
|
|
return skb;
|
|
|
|
err2:
|
|
kfree_skb(skb);
|
|
spin_unlock_bh(&sk->sk_receive_queue.lock);
|
|
netlink_overrun(sk);
|
|
err1:
|
|
sock_put(sk);
|
|
return NULL;
|
|
|
|
out_free:
|
|
kfree_skb(skb);
|
|
spin_unlock_bh(&sk->sk_receive_queue.lock);
|
|
out_put:
|
|
sock_put(sk);
|
|
out:
|
|
#endif
|
|
return alloc_skb(size, gfp_mask);
|
|
}
|
|
EXPORT_SYMBOL_GPL(netlink_alloc_skb);
|
|
|
|
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_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))
|
|
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_BROADCAST_SEND_ERROR)
|
|
p->delivery_failure = 1;
|
|
} else if (p->tx_filter && p->tx_filter(sk, p->skb2, p->tx_data)) {
|
|
kfree_skb(p->skb2);
|
|
p->skb2 = NULL;
|
|
} else if (sk_filter(sk, p->skb2)) {
|
|
kfree_skb(p->skb2);
|
|
p->skb2 = NULL;
|
|
} else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) {
|
|
netlink_overrun(sk);
|
|
if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR)
|
|
p->delivery_failure = 1;
|
|
} else {
|
|
p->congested |= val;
|
|
p->delivered = 1;
|
|
p->skb2 = NULL;
|
|
}
|
|
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 && (allocation & __GFP_WAIT))
|
|
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_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_RECV_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 (optname != NETLINK_RX_RING && optname != NETLINK_TX_RING &&
|
|
optlen >= sizeof(int) &&
|
|
get_user(val, (unsigned int __user *)optval))
|
|
return -EFAULT;
|
|
|
|
switch (optname) {
|
|
case NETLINK_PKTINFO:
|
|
if (val)
|
|
nlk->flags |= NETLINK_RECV_PKTINFO;
|
|
else
|
|
nlk->flags &= ~NETLINK_RECV_PKTINFO;
|
|
err = 0;
|
|
break;
|
|
case NETLINK_ADD_MEMBERSHIP:
|
|
case NETLINK_DROP_MEMBERSHIP: {
|
|
if (!netlink_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_BROADCAST_SEND_ERROR;
|
|
else
|
|
nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR;
|
|
err = 0;
|
|
break;
|
|
case NETLINK_NO_ENOBUFS:
|
|
if (val) {
|
|
nlk->flags |= NETLINK_RECV_NO_ENOBUFS;
|
|
clear_bit(NETLINK_CONGESTED, &nlk->state);
|
|
wake_up_interruptible(&nlk->wait);
|
|
} else {
|
|
nlk->flags &= ~NETLINK_RECV_NO_ENOBUFS;
|
|
}
|
|
err = 0;
|
|
break;
|
|
#ifdef CONFIG_NETLINK_MMAP
|
|
case NETLINK_RX_RING:
|
|
case NETLINK_TX_RING: {
|
|
struct nl_mmap_req req;
|
|
|
|
/* Rings might consume more memory than queue limits, require
|
|
* CAP_NET_ADMIN.
|
|
*/
|
|
if (!capable(CAP_NET_ADMIN))
|
|
return -EPERM;
|
|
if (optlen < sizeof(req))
|
|
return -EINVAL;
|
|
if (copy_from_user(&req, optval, sizeof(req)))
|
|
return -EFAULT;
|
|
err = netlink_set_ring(sk, &req, false,
|
|
optname == NETLINK_TX_RING);
|
|
break;
|
|
}
|
|
#endif /* CONFIG_NETLINK_MMAP */
|
|
default:
|
|
err = -ENOPROTOOPT;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static int netlink_getsockopt(struct socket *sock, int level, int optname,
|
|
char __user *optval, int __user *optlen)
|
|
{
|
|
struct sock *sk = sock->sk;
|
|
struct netlink_sock *nlk = nlk_sk(sk);
|
|
int len, val, err;
|
|
|
|
if (level != SOL_NETLINK)
|
|
return -ENOPROTOOPT;
|
|
|
|
if (get_user(len, optlen))
|
|
return -EFAULT;
|
|
if (len < 0)
|
|
return -EINVAL;
|
|
|
|
switch (optname) {
|
|
case NETLINK_PKTINFO:
|
|
if (len < sizeof(int))
|
|
return -EINVAL;
|
|
len = sizeof(int);
|
|
val = nlk->flags & NETLINK_RECV_PKTINFO ? 1 : 0;
|
|
if (put_user(len, optlen) ||
|
|
put_user(val, optval))
|
|
return -EFAULT;
|
|
err = 0;
|
|
break;
|
|
case NETLINK_BROADCAST_ERROR:
|
|
if (len < sizeof(int))
|
|
return -EINVAL;
|
|
len = sizeof(int);
|
|
val = nlk->flags & NETLINK_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_RECV_NO_ENOBUFS ? 1 : 0;
|
|
if (put_user(len, optlen) ||
|
|
put_user(val, optval))
|
|
return -EFAULT;
|
|
err = 0;
|
|
break;
|
|
default:
|
|
err = -ENOPROTOOPT;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
static void netlink_cmsg_recv_pktinfo(struct msghdr *msg, struct sk_buff *skb)
|
|
{
|
|
struct nl_pktinfo info;
|
|
|
|
info.group = NETLINK_CB(skb).dst_group;
|
|
put_cmsg(msg, SOL_NETLINK, NETLINK_PKTINFO, sizeof(info), &info);
|
|
}
|
|
|
|
static int netlink_sendmsg(struct 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 (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->portid) {
|
|
err = netlink_autobind(sock);
|
|
if (err)
|
|
goto out;
|
|
}
|
|
|
|
/* It's a really convoluted way for userland to ask for mmaped
|
|
* sendmsg(), but that's what we've got...
|
|
*/
|
|
if (netlink_tx_is_mmaped(sk) &&
|
|
msg->msg_iter.type == ITER_IOVEC &&
|
|
msg->msg_iter.nr_segs == 1 &&
|
|
msg->msg_iter.iov->iov_base == NULL) {
|
|
err = netlink_mmap_sendmsg(sk, msg, dst_portid, dst_group,
|
|
&scm);
|
|
goto out;
|
|
}
|
|
|
|
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) {
|
|
atomic_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,
|
|
16384);
|
|
|
|
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_RECV_PKTINFO)
|
|
netlink_cmsg_recv_pktinfo(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;
|
|
|
|
/*
|
|
* We have to just have a reference on the net from sk, but don't
|
|
* get_net it. Besides, we cannot get and then put the net here.
|
|
* So we create one inside init_net and the move it to net.
|
|
*/
|
|
|
|
if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0)
|
|
goto out_sock_release_nosk;
|
|
|
|
sk = sock->sk;
|
|
sk_change_net(sk, net);
|
|
|
|
if (!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_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)
|
|
{
|
|
sk_release_kernel(sk);
|
|
}
|
|
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 = (struct nlmsghdr *)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;
|
|
int len, err = -ENOBUFS;
|
|
int alloc_size;
|
|
|
|
mutex_lock(nlk->cb_mutex);
|
|
if (!nlk->cb_running) {
|
|
err = -EINVAL;
|
|
goto errout_skb;
|
|
}
|
|
|
|
cb = &nlk->cb;
|
|
alloc_size = max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE);
|
|
|
|
if (!netlink_rx_is_mmaped(sk) &&
|
|
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.
|
|
*/
|
|
if (alloc_size < nlk->max_recvmsg_len) {
|
|
skb = netlink_alloc_skb(sk,
|
|
nlk->max_recvmsg_len,
|
|
nlk->portid,
|
|
GFP_KERNEL |
|
|
__GFP_NOWARN |
|
|
__GFP_NORETRY);
|
|
/* available room should be exact amount to avoid MSG_TRUNC */
|
|
if (skb)
|
|
skb_reserve(skb, skb_tailroom(skb) -
|
|
nlk->max_recvmsg_len);
|
|
}
|
|
if (!skb)
|
|
skb = netlink_alloc_skb(sk, alloc_size, nlk->portid,
|
|
GFP_KERNEL);
|
|
if (!skb)
|
|
goto errout_skb;
|
|
netlink_skb_set_owner_r(skb, sk);
|
|
|
|
len = cb->dump(skb, cb);
|
|
|
|
if (len > 0) {
|
|
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(len), NLM_F_MULTI);
|
|
if (!nlh)
|
|
goto errout_skb;
|
|
|
|
nl_dump_check_consistent(cb, nlh);
|
|
|
|
memcpy(nlmsg_data(nlh), &len, sizeof(len));
|
|
|
|
if (sk_filter(sk, skb))
|
|
kfree_skb(skb);
|
|
else
|
|
__netlink_sendskb(sk, skb);
|
|
|
|
if (cb->done)
|
|
cb->done(cb);
|
|
|
|
nlk->cb_running = false;
|
|
mutex_unlock(nlk->cb_mutex);
|
|
module_put(cb->module);
|
|
consume_skb(cb->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;
|
|
|
|
/* Memory mapped dump requests need to be copied to avoid looping
|
|
* on the pending state in netlink_mmap_sendmsg() while the CB hold
|
|
* a reference to the skb.
|
|
*/
|
|
if (netlink_skb_is_mmaped(skb)) {
|
|
skb = skb_copy(skb, GFP_KERNEL);
|
|
if (skb == NULL)
|
|
return -ENOBUFS;
|
|
} else
|
|
atomic_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;
|
|
|
|
nlk->cb_running = true;
|
|
|
|
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_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)
|
|
{
|
|
struct sk_buff *skb;
|
|
struct nlmsghdr *rep;
|
|
struct nlmsgerr *errmsg;
|
|
size_t payload = sizeof(*errmsg);
|
|
|
|
/* error messages get the original request appened */
|
|
if (err)
|
|
payload += nlmsg_len(nlh);
|
|
|
|
skb = netlink_alloc_skb(in_skb->sk, nlmsg_total_size(payload),
|
|
NETLINK_CB(in_skb).portid, GFP_KERNEL);
|
|
if (!skb) {
|
|
struct sock *sk;
|
|
|
|
sk = netlink_lookup(sock_net(in_skb->sk),
|
|
in_skb->sk->sk_protocol,
|
|
NETLINK_CB(in_skb).portid);
|
|
if (sk) {
|
|
sk->sk_err = ENOBUFS;
|
|
sk->sk_error_report(sk);
|
|
sock_put(sk);
|
|
}
|
|
return;
|
|
}
|
|
|
|
rep = __nlmsg_put(skb, NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
|
|
NLMSG_ERROR, payload, 0);
|
|
errmsg = nlmsg_data(rep);
|
|
errmsg->error = err;
|
|
memcpy(&errmsg->msg, nlh, err ? nlh->nlmsg_len : sizeof(*nlh));
|
|
netlink_unicast(in_skb->sk, skb, NETLINK_CB(in_skb).portid, MSG_DONTWAIT);
|
|
}
|
|
EXPORT_SYMBOL(netlink_ack);
|
|
|
|
int netlink_rcv_skb(struct sk_buff *skb, int (*cb)(struct sk_buff *,
|
|
struct nlmsghdr *))
|
|
{
|
|
struct nlmsghdr *nlh;
|
|
int err;
|
|
|
|
while (skb->len >= nlmsg_total_size(0)) {
|
|
int msglen;
|
|
|
|
nlh = nlmsg_hdr(skb);
|
|
err = 0;
|
|
|
|
if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len)
|
|
return 0;
|
|
|
|
/* Only requests are handled by the kernel */
|
|
if (!(nlh->nlmsg_flags & NLM_F_REQUEST))
|
|
goto ack;
|
|
|
|
/* Skip control messages */
|
|
if (nlh->nlmsg_type < NLMSG_MIN_TYPE)
|
|
goto ack;
|
|
|
|
err = cb(skb, nlh);
|
|
if (err == -EINTR)
|
|
goto skip;
|
|
|
|
ack:
|
|
if (nlh->nlmsg_flags & NLM_F_ACK || err)
|
|
netlink_ack(skb, nlh, err);
|
|
|
|
skip:
|
|
msglen = NLMSG_ALIGN(nlh->nlmsg_len);
|
|
if (msglen > skb->len)
|
|
msglen = skb->len;
|
|
skb_pull(skb, msglen);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(netlink_rcv_skb);
|
|
|
|
/**
|
|
* nlmsg_notify - send a notification netlink message
|
|
* @sk: netlink socket to use
|
|
* @skb: notification message
|
|
* @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) {
|
|
atomic_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);
|
|
if (err) {
|
|
iter->link = MAX_LINKS;
|
|
return err;
|
|
}
|
|
|
|
err = rhashtable_walk_start(&iter->hti);
|
|
return err == -EAGAIN ? 0 : err;
|
|
}
|
|
|
|
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 %-6u %08x %-8d %-8d %d %-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,
|
|
atomic_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,
|
|
};
|
|
|
|
|
|
static int netlink_seq_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open_net(inode, file, &netlink_seq_ops,
|
|
sizeof(struct nl_seq_iter));
|
|
}
|
|
|
|
static const struct file_operations netlink_seq_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = netlink_seq_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release_net,
|
|
};
|
|
|
|
#endif
|
|
|
|
int netlink_register_notifier(struct notifier_block *nb)
|
|
{
|
|
return atomic_notifier_chain_register(&netlink_chain, nb);
|
|
}
|
|
EXPORT_SYMBOL(netlink_register_notifier);
|
|
|
|
int netlink_unregister_notifier(struct notifier_block *nb)
|
|
{
|
|
return atomic_notifier_chain_unregister(&netlink_chain, nb);
|
|
}
|
|
EXPORT_SYMBOL(netlink_unregister_notifier);
|
|
|
|
static const struct proto_ops netlink_ops = {
|
|
.family = PF_NETLINK,
|
|
.owner = THIS_MODULE,
|
|
.release = netlink_release,
|
|
.bind = netlink_bind,
|
|
.connect = netlink_connect,
|
|
.socketpair = sock_no_socketpair,
|
|
.accept = sock_no_accept,
|
|
.getname = netlink_getname,
|
|
.poll = netlink_poll,
|
|
.ioctl = sock_no_ioctl,
|
|
.listen = sock_no_listen,
|
|
.shutdown = sock_no_shutdown,
|
|
.setsockopt = netlink_setsockopt,
|
|
.getsockopt = netlink_getsockopt,
|
|
.sendmsg = netlink_sendmsg,
|
|
.recvmsg = netlink_recvmsg,
|
|
.mmap = netlink_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("netlink", 0, net->proc_net, &netlink_seq_fops))
|
|
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 int __init netlink_proto_init(void)
|
|
{
|
|
int i;
|
|
int err = proto_register(&netlink_proto, 0);
|
|
struct rhashtable_params ht_params = {
|
|
.head_offset = offsetof(struct netlink_sock, node),
|
|
.key_offset = offsetof(struct netlink_sock, portid),
|
|
.key_len = sizeof(u32), /* portid */
|
|
.hashfn = jhash,
|
|
.max_shift = 16, /* 64K */
|
|
};
|
|
|
|
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, &ht_params) < 0) {
|
|
while (--i > 0)
|
|
rhashtable_destroy(&nl_table[i].hash);
|
|
kfree(nl_table);
|
|
goto panic;
|
|
}
|
|
}
|
|
|
|
INIT_LIST_HEAD(&netlink_tap_all);
|
|
|
|
netlink_add_usersock_entry();
|
|
|
|
sock_register(&netlink_family_ops);
|
|
register_pernet_subsys(&netlink_net_ops);
|
|
/* The netlink device handler may be needed early. */
|
|
rtnetlink_init();
|
|
out:
|
|
return err;
|
|
panic:
|
|
panic("netlink_init: Cannot allocate nl_table\n");
|
|
}
|
|
|
|
core_initcall(netlink_proto_init);
|