text: /*
   * INET		An implementation of the TCP/IP protocol suite for the LINUX
   *		operating system.  INET is implemented using the  BSD Socket
   *		interface as the means of communication with the user level.
   *
   *		Generic socket support routines. Memory allocators, socket lock/release
   *		handler for protocols to use and generic option handler.
   *
   *
   * Authors:	Ross Biro
   *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
   *		Florian La Roche, <flla@stud.uni-sb.de>
   *		Alan Cox, <A.Cox@swansea.ac.uk>
   *
   * Fixes:
   *		Alan Cox	: 	Numerous verify_area() problems
   *		Alan Cox	:	Connecting on a connecting socket
   *					now returns an error for tcp.
   *		Alan Cox	:	sock->protocol is set correctly.
   *					and is not sometimes left as 0.
   *		Alan Cox	:	connect handles icmp errors on a
   *					connect properly. Unfortunately there
   *					is a restart syscall nasty there. I
   *					can't match BSD without hacking the C
   *					library. Ideas urgently sought!
   *		Alan Cox	:	Disallow bind() to addresses that are
   *					not ours - especially broadcast ones!!
   *		Alan Cox	:	Socket 1024 _IS_ ok for users. (fencepost)
   *		Alan Cox	:	sock_wfree/sock_rfree don't destroy sockets,
   *					instead they leave that for the DESTROY timer.
   *		Alan Cox	:	Clean up error flag in accept
   *		Alan Cox	:	TCP ack handling is buggy, the DESTROY timer
   *					was buggy. Put a remove_sock() in the handler
   *					for memory when we hit 0. Also altered the timer
   *					code. The ACK stuff can wait and needs major
   *					TCP layer surgery.
   *		Alan Cox	:	Fixed TCP ack bug, removed remove sock
   *					and fixed timer/inet_bh race.
   *		Alan Cox	:	Added zapped flag for TCP
   *		Alan Cox	:	Move kfree_skb into skbuff.c and tidied up surplus code
   *		Alan Cox	:	for new sk_buff allocations wmalloc/rmalloc now call alloc_skb
   *		Alan Cox	:	kfree_s calls now are kfree_skbmem so we can track skb resources
   *		Alan Cox	:	Supports socket option broadcast now as does udp. Packet and raw need fixing.
   *		Alan Cox	:	Added RCVBUF,SNDBUF size setting. It suddenly occurred to me how easy it was so...
   *		Rick Sladkey	:	Relaxed UDP rules for matching packets.
   *		C.E.Hawkins	:	IFF_PROMISC/SIOCGHWADDR support
   *	Pauline Middelink	:	identd support
   *		Alan Cox	:	Fixed connect() taking signals I think.
   *		Alan Cox	:	SO_LINGER supported
   *		Alan Cox	:	Error reporting fixes
   *		Anonymous	:	inet_create tidied up (sk->reuse setting)
   *		Alan Cox	:	inet sockets don't set sk->type!
   *		Alan Cox	:	Split socket option code
   *		Alan Cox	:	Callbacks
   *		Alan Cox	:	Nagle flag for Charles & Johannes stuff
   *		Alex		:	Removed restriction on inet fioctl
   *		Alan Cox	:	Splitting INET from NET core
   *		Alan Cox	:	Fixed bogus SO_TYPE handling in getsockopt()
   *		Adam Caldwell	:	Missing return in SO_DONTROUTE/SO_DEBUG code
   *		Alan Cox	:	Split IP from generic code
   *		Alan Cox	:	New kfree_skbmem()
   *		Alan Cox	:	Make SO_DEBUG superuser only.
   *		Alan Cox	:	Allow anyone to clear SO_DEBUG
   *					(compatibility fix)
   *		Alan Cox	:	Added optimistic memory grabbing for AF_UNIX throughput.
   *		Alan Cox	:	Allocator for a socket is settable.
   *		Alan Cox	:	SO_ERROR includes soft errors.
   *		Alan Cox	:	Allow NULL arguments on some SO_ opts
   *		Alan Cox	: 	Generic socket allocation to make hooks
   *					easier (suggested by Craig Metz).
   *		Michael Pall	:	SO_ERROR returns positive errno again
   *              Steve Whitehouse:       Added default destructor to free
   *                                      protocol private data.
   *              Steve Whitehouse:       Added various other default routines
   *                                      common to several socket families.
   *              Chris Evans     :       Call suser() check last on F_SETOWN
   *		Jay Schulist	:	Added SO_ATTACH_FILTER and SO_DETACH_FILTER.
   *		Andi Kleen	:	Add sock_kmalloc()/sock_kfree_s()
   *		Andi Kleen	:	Fix write_space callback
   *		Chris Evans	:	Security fixes - signedness again
   *		Arnaldo C. Melo :       cleanups, use skb_queue_purge
   *
   * To Fix:
   *
   *
   *		This program is free software; you can redistribute it and/or
   *		modify it under the terms of the GNU General Public License
   *		as published by the Free Software Foundation; either version
   *		2 of the License, or (at your option) any later version.
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/capability.h>
  #include <linux/errno.h>
  #include <linux/types.h>
  #include <linux/socket.h>
  #include <linux/in.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/proc_fs.h>
  #include <linux/seq_file.h>
  #include <linux/sched.h>
  #include <linux/timer.h>
  #include <linux/string.h>
  #include <linux/sockios.h>
  #include <linux/net.h>
  #include <linux/mm.h>
  #include <linux/slab.h>
  #include <linux/interrupt.h>
  #include <linux/poll.h>
  #include <linux/tcp.h>
  #include <linux/init.h>
  #include <linux/highmem.h>
  #include <linux/user_namespace.h>
  #include <linux/static_key.h>
  #include <linux/memcontrol.h>
  #include <linux/prefetch.h>
  
  #include <asm/uaccess.h>
  
  #include <linux/netdevice.h>
  #include <net/protocol.h>
  #include <linux/skbuff.h>
  #include <net/net_namespace.h>
  #include <net/request_sock.h>
  #include <net/sock.h>
  #include <linux/net_tstamp.h>
  #include <net/xfrm.h>
  #include <linux/ipsec.h>
  #include <net/cls_cgroup.h>
  #include <net/netprio_cgroup.h>
  
  #include <linux/filter.h>
  
  #include <trace/events/sock.h>
  
  #include <net/af_unix.h>
  
  
  #ifdef CONFIG_INET
  #include <net/tcp.h>
  #endif
  #include <linux/xlog.h>
  
  static DEFINE_MUTEX(proto_list_mutex);
  static LIST_HEAD(proto_list);
  
  /**
   * sk_ns_capable - General socket capability test
   * @sk: Socket to use a capability on or through
   * @user_ns: The user namespace of the capability to use
   * @cap: The capability to use
   *
   * Test to see if the opener of the socket had when the socket was
   * created and the current process has the capability @cap in the user
   * namespace @user_ns.
   */
  bool sk_ns_capable(const struct sock *sk,
  		   struct user_namespace *user_ns, int cap)
  {
  	return file_ns_capable(sk->sk_socket->file, user_ns, cap) &&
  		ns_capable(user_ns, cap);
  }
  EXPORT_SYMBOL(sk_ns_capable);
  
  /**
   * sk_capable - Socket global capability test
   * @sk: Socket to use a capability on or through
   * @cap: The global capbility to use
   *
   * Test to see if the opener of the socket had when the socket was
   * created and the current process has the capability @cap in all user
   * namespaces.
   */
  bool sk_capable(const struct sock *sk, int cap)
  {
  	return sk_ns_capable(sk, &init_user_ns, cap);
  }
  EXPORT_SYMBOL(sk_capable);
  
  /**
   * sk_net_capable - Network namespace socket capability test
   * @sk: Socket to use a capability on or through
   * @cap: The capability to use
   *
   * Test to see if the opener of the socket had when the socke was created
   * and the current process has the capability @cap over the network namespace
   * the socket is a member of.
   */
  bool sk_net_capable(const struct sock *sk, int cap)
  {
  	return sk_ns_capable(sk, sock_net(sk)->user_ns, cap);
  }
  EXPORT_SYMBOL(sk_net_capable);
  
  
  #ifdef CONFIG_MEMCG_KMEM
  int mem_cgroup_sockets_init(struct mem_cgroup *memcg, struct cgroup_subsys *ss)
  {
  	struct proto *proto;
  	int ret = 0;
  
  	mutex_lock(&proto_list_mutex);
  	list_for_each_entry(proto, &proto_list, node) {
  		if (proto->init_cgroup) {
  			ret = proto->init_cgroup(memcg, ss);
  			if (ret)
  				goto out;
  		}
  	}
  
  	mutex_unlock(&proto_list_mutex);
  	return ret;
  out:
  	list_for_each_entry_continue_reverse(proto, &proto_list, node)
  		if (proto->destroy_cgroup)
  			proto->destroy_cgroup(memcg);
  	mutex_unlock(&proto_list_mutex);
  	return ret;
  }
  
  void mem_cgroup_sockets_destroy(struct mem_cgroup *memcg)
  {
  	struct proto *proto;
  
  	mutex_lock(&proto_list_mutex);
  	list_for_each_entry_reverse(proto, &proto_list, node)
  		if (proto->destroy_cgroup)
  			proto->destroy_cgroup(memcg);
  	mutex_unlock(&proto_list_mutex);
  }
  #endif
  
  /*
   * Each address family might have different locking rules, so we have
   * one slock key per address family:
   */
  static struct lock_class_key af_family_keys[AF_MAX];
  static struct lock_class_key af_family_slock_keys[AF_MAX];
  
  #if defined(CONFIG_MEMCG_KMEM)
  struct static_key memcg_socket_limit_enabled;
  EXPORT_SYMBOL(memcg_socket_limit_enabled);
  #endif
  
  /*
   * Make lock validator output more readable. (we pre-construct these
   * strings build-time, so that runtime initialization of socket
   * locks is fast):
   */
  static const char *const af_family_key_strings[AF_MAX+1] = {
    "sk_lock-AF_UNSPEC", "sk_lock-AF_UNIX"     , "sk_lock-AF_INET"     ,
    "sk_lock-AF_AX25"  , "sk_lock-AF_IPX"      , "sk_lock-AF_APPLETALK",
    "sk_lock-AF_NETROM", "sk_lock-AF_BRIDGE"   , "sk_lock-AF_ATMPVC"   ,
    "sk_lock-AF_X25"   , "sk_lock-AF_INET6"    , "sk_lock-AF_ROSE"     ,
    "sk_lock-AF_DECnet", "sk_lock-AF_NETBEUI"  , "sk_lock-AF_SECURITY" ,
    "sk_lock-AF_KEY"   , "sk_lock-AF_NETLINK"  , "sk_lock-AF_PACKET"   ,
    "sk_lock-AF_ASH"   , "sk_lock-AF_ECONET"   , "sk_lock-AF_ATMSVC"   ,
    "sk_lock-AF_RDS"   , "sk_lock-AF_SNA"      , "sk_lock-AF_IRDA"     ,
    "sk_lock-AF_PPPOX" , "sk_lock-AF_WANPIPE"  , "sk_lock-AF_LLC"      ,
    "sk_lock-27"       , "sk_lock-28"          , "sk_lock-AF_CAN"      ,
    "sk_lock-AF_TIPC"  , "sk_lock-AF_BLUETOOTH", "sk_lock-IUCV"        ,
    "sk_lock-AF_RXRPC" , "sk_lock-AF_ISDN"     , "sk_lock-AF_PHONET"   ,
    "sk_lock-AF_IEEE802154", "sk_lock-AF_CAIF" , "sk_lock-AF_ALG"      ,
    "sk_lock-AF_NFC"   , "sk_lock-AF_VSOCK"    , "sk_lock-AF_MAX"
  };
  static const char *const af_family_slock_key_strings[AF_MAX+1] = {
    "slock-AF_UNSPEC", "slock-AF_UNIX"     , "slock-AF_INET"     ,
    "slock-AF_AX25"  , "slock-AF_IPX"      , "slock-AF_APPLETALK",
    "slock-AF_NETROM", "slock-AF_BRIDGE"   , "slock-AF_ATMPVC"   ,
    "slock-AF_X25"   , "slock-AF_INET6"    , "slock-AF_ROSE"     ,
    "slock-AF_DECnet", "slock-AF_NETBEUI"  , "slock-AF_SECURITY" ,
    "slock-AF_KEY"   , "slock-AF_NETLINK"  , "slock-AF_PACKET"   ,
    "slock-AF_ASH"   , "slock-AF_ECONET"   , "slock-AF_ATMSVC"   ,
    "slock-AF_RDS"   , "slock-AF_SNA"      , "slock-AF_IRDA"     ,
    "slock-AF_PPPOX" , "slock-AF_WANPIPE"  , "slock-AF_LLC"      ,
    "slock-27"       , "slock-28"          , "slock-AF_CAN"      ,
    "slock-AF_TIPC"  , "slock-AF_BLUETOOTH", "slock-AF_IUCV"     ,
    "slock-AF_RXRPC" , "slock-AF_ISDN"     , "slock-AF_PHONET"   ,
    "slock-AF_IEEE802154", "slock-AF_CAIF" , "slock-AF_ALG"      ,
    "slock-AF_NFC"   , "slock-AF_VSOCK"    ,"slock-AF_MAX"
  };
  static const char *const af_family_clock_key_strings[AF_MAX+1] = {
    "clock-AF_UNSPEC", "clock-AF_UNIX"     , "clock-AF_INET"     ,
    "clock-AF_AX25"  , "clock-AF_IPX"      , "clock-AF_APPLETALK",
    "clock-AF_NETROM", "clock-AF_BRIDGE"   , "clock-AF_ATMPVC"   ,
    "clock-AF_X25"   , "clock-AF_INET6"    , "clock-AF_ROSE"     ,
    "clock-AF_DECnet", "clock-AF_NETBEUI"  , "clock-AF_SECURITY" ,
    "clock-AF_KEY"   , "clock-AF_NETLINK"  , "clock-AF_PACKET"   ,
    "clock-AF_ASH"   , "clock-AF_ECONET"   , "clock-AF_ATMSVC"   ,
    "clock-AF_RDS"   , "clock-AF_SNA"      , "clock-AF_IRDA"     ,
    "clock-AF_PPPOX" , "clock-AF_WANPIPE"  , "clock-AF_LLC"      ,
    "clock-27"       , "clock-28"          , "clock-AF_CAN"      ,
    "clock-AF_TIPC"  , "clock-AF_BLUETOOTH", "clock-AF_IUCV"     ,
    "clock-AF_RXRPC" , "clock-AF_ISDN"     , "clock-AF_PHONET"   ,
    "clock-AF_IEEE802154", "clock-AF_CAIF" , "clock-AF_ALG"      ,
    "clock-AF_NFC"   , "clock-AF_VSOCK"    , "clock-AF_MAX"
  };
  
  /*
   * sk_callback_lock locking rules are per-address-family,
   * so split the lock classes by using a per-AF key:
   */
  static struct lock_class_key af_callback_keys[AF_MAX];
  
  /* Take into consideration the size of the struct sk_buff overhead in the
   * determination of these values, since that is non-constant across
   * platforms.  This makes socket queueing behavior and performance
   * not depend upon such differences.
   */
  #define _SK_MEM_PACKETS		256
  #define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
  #define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
  #define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
  
  /* Run time adjustable parameters. */
  __u32 sysctl_wmem_max __read_mostly = SK_WMEM_MAX;
  EXPORT_SYMBOL(sysctl_wmem_max);
  __u32 sysctl_rmem_max __read_mostly = (SK_RMEM_MAX*8);
  EXPORT_SYMBOL(sysctl_rmem_max);
  __u32 sysctl_wmem_default __read_mostly = SK_WMEM_MAX;
  __u32 sysctl_rmem_default __read_mostly = SK_RMEM_MAX;
  
  /* Maximal space eaten by iovec or ancillary data plus some space */
  int sysctl_optmem_max __read_mostly = sizeof(unsigned long)*(2*UIO_MAXIOV+512);
  EXPORT_SYMBOL(sysctl_optmem_max);
  
  struct static_key memalloc_socks = STATIC_KEY_INIT_FALSE;
  EXPORT_SYMBOL_GPL(memalloc_socks);
  
  /**
   * sk_set_memalloc - sets %SOCK_MEMALLOC
   * @sk: socket to set it on
   *
   * Set %SOCK_MEMALLOC on a socket for access to emergency reserves.
   * It's the responsibility of the admin to adjust min_free_kbytes
   * to meet the requirements
   */
  void sk_set_memalloc(struct sock *sk)
  {
  	sock_set_flag(sk, SOCK_MEMALLOC);
  	sk->sk_allocation |= __GFP_MEMALLOC;
  	static_key_slow_inc(&memalloc_socks);
  }
  EXPORT_SYMBOL_GPL(sk_set_memalloc);
  
  void sk_clear_memalloc(struct sock *sk)
  {
  	sock_reset_flag(sk, SOCK_MEMALLOC);
  	sk->sk_allocation &= ~__GFP_MEMALLOC;
  	static_key_slow_dec(&memalloc_socks);
  
  	/*
  	 * SOCK_MEMALLOC is allowed to ignore rmem limits to ensure forward
  	 * progress of swapping. However, if SOCK_MEMALLOC is cleared while
  	 * it has rmem allocations there is a risk that the user of the
  	 * socket cannot make forward progress due to exceeding the rmem
  	 * limits. By rights, sk_clear_memalloc() should only be called
  	 * on sockets being torn down but warn and reset the accounting if
  	 * that assumption breaks.
  	 */
  	if (WARN_ON(sk->sk_forward_alloc))
  		sk_mem_reclaim(sk);
  }
  EXPORT_SYMBOL_GPL(sk_clear_memalloc);
  
  int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
  {
  	int ret;
  	unsigned long pflags = current->flags;
  
  	/* these should have been dropped before queueing */
  	BUG_ON(!sock_flag(sk, SOCK_MEMALLOC));
  
  	current->flags |= PF_MEMALLOC;
  	ret = sk->sk_backlog_rcv(sk, skb);
  	tsk_restore_flags(current, pflags, PF_MEMALLOC);
  
  	return ret;
  }
  EXPORT_SYMBOL(__sk_backlog_rcv);
  
  static int sock_set_timeout(long *timeo_p, char __user *optval, int optlen)
  {
  	struct timeval tv;
  
  	if (optlen < sizeof(tv))
  		return -EINVAL;
  	if (copy_from_user(&tv, optval, sizeof(tv)))
  		return -EFAULT;
  	if (tv.tv_usec < 0 || tv.tv_usec >= USEC_PER_SEC)
  		return -EDOM;
  
  	if (tv.tv_sec < 0) {
  		static int warned __read_mostly;
  
  		*timeo_p = 0;
  		if (warned < 10 && net_ratelimit()) {
  			warned++;
  			pr_info("%s: `%s' (pid %d) tries to set negative timeout\n",
  				__func__, current->comm, task_pid_nr(current));
  		}
  		return 0;
  	}
  	*timeo_p = MAX_SCHEDULE_TIMEOUT;
  	if (tv.tv_sec == 0 && tv.tv_usec == 0)
  		return 0;
  	if (tv.tv_sec < (MAX_SCHEDULE_TIMEOUT/HZ - 1))
  		*timeo_p = tv.tv_sec*HZ + (tv.tv_usec+(1000000/HZ-1))/(1000000/HZ);
  	return 0;
  }
  
  static void sock_warn_obsolete_bsdism(const char *name)
  {
  	static int warned;
  	static char warncomm[TASK_COMM_LEN];
  	if (strcmp(warncomm, current->comm) && warned < 5) {
  		strcpy(warncomm,  current->comm);
  		pr_warn("process `%s' is using obsolete %s SO_BSDCOMPAT\n",
  			warncomm, name);
  		warned++;
  	}
  }
  
  #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
  
  static void sock_disable_timestamp(struct sock *sk, unsigned long flags)
  {
  	if (sk->sk_flags & flags) {
  		sk->sk_flags &= ~flags;
  		if (!(sk->sk_flags & SK_FLAGS_TIMESTAMP))
  			net_disable_timestamp();
  	}
  }
  
  
  int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
  {
  	int err;
  	int skb_len;
  	unsigned long flags;
  	struct sk_buff_head *list = &sk->sk_receive_queue;
  
  	if (atomic_read(&sk->sk_rmem_alloc) >= sk->sk_rcvbuf) {
  		atomic_inc(&sk->sk_drops);
  		trace_sock_rcvqueue_full(sk, skb);
  		return -ENOMEM;
  	}
  
  	err = sk_filter(sk, skb);
  	if (err)
  		return err;
  
  	if (!sk_rmem_schedule(sk, skb, skb->truesize)) {
  		atomic_inc(&sk->sk_drops);
  		return -ENOBUFS;
  	}
  
  	skb->dev = NULL;
  	skb_set_owner_r(skb, sk);
  
  	/* Cache the SKB length before we tack it onto the receive
  	 * queue.  Once it is added it no longer belongs to us and
  	 * may be freed by other threads of control pulling packets
  	 * from the queue.
  	 */
  	skb_len = skb->len;
  
  	/* we escape from rcu protected region, make sure we dont leak
  	 * a norefcounted dst
  	 */
  	skb_dst_force(skb);
  
  	spin_lock_irqsave(&list->lock, flags);
  	skb->dropcount = atomic_read(&sk->sk_drops);
  	__skb_queue_tail(list, skb);
  	spin_unlock_irqrestore(&list->lock, flags);
  
  	if (!sock_flag(sk, SOCK_DEAD))
  		sk->sk_data_ready(sk, skb_len);
  	return 0;
  }
  EXPORT_SYMBOL(sock_queue_rcv_skb);
  
  int sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested)
  {
  	int rc = NET_RX_SUCCESS;
  
  	if (sk_filter(sk, skb))
  		goto discard_and_relse;
  
  	skb->dev = NULL;
  
  	if (sk_rcvqueues_full(sk, skb, sk->sk_rcvbuf)) {
  		atomic_inc(&sk->sk_drops);
  		goto discard_and_relse;
  	}
  	if (nested)
  		bh_lock_sock_nested(sk);
  	else
  		bh_lock_sock(sk);
  	if (!sock_owned_by_user(sk)) {
  		/*
  		 * trylock + unlock semantics:
  		 */
  		mutex_acquire(&sk->sk_lock.dep_map, 0, 1, _RET_IP_);
  
  		rc = sk_backlog_rcv(sk, skb);
  
  		mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
  	} else if (sk_add_backlog(sk, skb, sk->sk_rcvbuf)) {
  		bh_unlock_sock(sk);
  		atomic_inc(&sk->sk_drops);
  		goto discard_and_relse;
  	}
  
  	bh_unlock_sock(sk);
  out:
  	sock_put(sk);
  	return rc;
  discard_and_relse:
  	kfree_skb(skb);
  	goto out;
  }
  EXPORT_SYMBOL(sk_receive_skb);
  
  void sk_reset_txq(struct sock *sk)
  {
  	sk_tx_queue_clear(sk);
  }
  EXPORT_SYMBOL(sk_reset_txq);
  
  struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie)
  {
  	struct dst_entry *dst = __sk_dst_get(sk);
  
  	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
  		sk_tx_queue_clear(sk);
  		RCU_INIT_POINTER(sk->sk_dst_cache, NULL);
  		dst_release(dst);
  		return NULL;
  	}
  
  	return dst;
  }
  EXPORT_SYMBOL(__sk_dst_check);
  
  struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie)
  {
  	struct dst_entry *dst = sk_dst_get(sk);
  
  	if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
  		sk_dst_reset(sk);
  		dst_release(dst);
  		return NULL;
  	}
  
  	return dst;
  }
  EXPORT_SYMBOL(sk_dst_check);
  
  static int sock_setbindtodevice(struct sock *sk, char __user *optval,
  				int optlen)
  {
  	int ret = -ENOPROTOOPT;
  #ifdef CONFIG_NETDEVICES
  	struct net *net = sock_net(sk);
  	char devname[IFNAMSIZ];
  	int index;
  
  	/* Sorry... */
  	ret = -EPERM;
  	if (!ns_capable(net->user_ns, CAP_NET_RAW))
  		goto out;
  
  	ret = -EINVAL;
  	if (optlen < 0)
  		goto out;
  
  	/* Bind this socket to a particular device like "eth0",
  	 * as specified in the passed interface name. If the
  	 * name is "" or the option length is zero the socket
  	 * is not bound.
  	 */
  	if (optlen > IFNAMSIZ - 1)
  		optlen = IFNAMSIZ - 1;
  	memset(devname, 0, sizeof(devname));
  
  	ret = -EFAULT;
  	if (copy_from_user(devname, optval, optlen))
  		goto out;
  
  	index = 0;
  	if (devname[0] != '\0') {
  		struct net_device *dev;
  
  		rcu_read_lock();
  		dev = dev_get_by_name_rcu(net, devname);
  		if (dev)
  			index = dev->ifindex;
  		rcu_read_unlock();
  		ret = -ENODEV;
  		if (!dev)
  			goto out;
  	}
  
  	lock_sock(sk);
  	sk->sk_bound_dev_if = index;
  	sk_dst_reset(sk);
  	release_sock(sk);
  
  	ret = 0;
  
  out:
  #endif
  
  	return ret;
  }
  
  static int sock_getbindtodevice(struct sock *sk, char __user *optval,
  				int __user *optlen, int len)
  {
  	int ret = -ENOPROTOOPT;
  #ifdef CONFIG_NETDEVICES
  	struct net *net = sock_net(sk);
  	char devname[IFNAMSIZ];
  
  	if (sk->sk_bound_dev_if == 0) {
  		len = 0;
  		goto zero;
  	}
  
  	ret = -EINVAL;
  	if (len < IFNAMSIZ)
  		goto out;
  
  	ret = netdev_get_name(net, devname, sk->sk_bound_dev_if);
  	if (ret)
  		goto out;
  
  	len = strlen(devname) + 1;
  
  	ret = -EFAULT;
  	if (copy_to_user(optval, devname, len))
  		goto out;
  
  zero:
  	ret = -EFAULT;
  	if (put_user(len, optlen))
  		goto out;
  
  	ret = 0;
  
  out:
  #endif
  
  	return ret;
  }
  
  static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
  {
  	if (valbool)
  		sock_set_flag(sk, bit);
  	else
  		sock_reset_flag(sk, bit);
  }
  
  /*
   *	This is meant for all protocols to use and covers goings on
   *	at the socket level. Everything here is generic.
   */
  
  int sock_setsockopt(struct socket *sock, int level, int optname,
  		    char __user *optval, unsigned int optlen)
  {
  	struct sock *sk = sock->sk;
  	int val;
  	int valbool;
  	struct linger ling;
  	int ret = 0;
  
  	/*
  	 *	Options without arguments
  	 */
  
  	if (optname == SO_BINDTODEVICE)
  		return sock_setbindtodevice(sk, optval, optlen);
  
  	if (optlen < sizeof(int))
  		return -EINVAL;
  
  	if (get_user(val, (int __user *)optval))
  		return -EFAULT;
  
  	valbool = val ? 1 : 0;
  
  	lock_sock(sk);
  
  	switch (optname) {
  	case SO_DEBUG:
  		if (val && !capable(CAP_NET_ADMIN))
  			ret = -EACCES;
  		else
  			sock_valbool_flag(sk, SOCK_DBG, valbool);
  		break;
  	case SO_REUSEADDR:
  		sk->sk_reuse = (valbool ? SK_CAN_REUSE : SK_NO_REUSE);
  		break;
  	case SO_REUSEPORT:
  		sk->sk_reuseport = valbool;
  		break;
  	case SO_TYPE:
  	case SO_PROTOCOL:
  	case SO_DOMAIN:
  	case SO_ERROR:
  		ret = -ENOPROTOOPT;
  		break;
  	case SO_DONTROUTE:
  		sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
  		break;
  	case SO_BROADCAST:
  		sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
  		break;
  	case SO_SNDBUF:
  		/* Don't error on this BSD doesn't and if you think
  		 * about it this is right. Otherwise apps have to
  		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
  		 * are treated in BSD as hints
  		 */
  		val = min_t(u32, val, sysctl_wmem_max);
  set_sndbuf:
  		sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
  		sk->sk_sndbuf = max_t(u32, val * 2, SOCK_MIN_SNDBUF);
  		/* Wake up sending tasks if we upped the value. */
  		sk->sk_write_space(sk);
  		break;
  
  	case SO_SNDBUFFORCE:
  		if (!capable(CAP_NET_ADMIN)) {
  			ret = -EPERM;
  			break;
  		}
  		goto set_sndbuf;
  
  	case SO_RCVBUF:
  		/* Don't error on this BSD doesn't and if you think
  		 * about it this is right. Otherwise apps have to
  		 * play 'guess the biggest size' games. RCVBUF/SNDBUF
  		 * are treated in BSD as hints
  		 */
  		val = min_t(u32, val, sysctl_rmem_max);
  set_rcvbuf:
  		sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
  		/*
  		 * We double it on the way in to account for
  		 * "struct sk_buff" etc. overhead.   Applications
  		 * assume that the SO_RCVBUF setting they make will
  		 * allow that much actual data to be received on that
  		 * socket.
  		 *
  		 * Applications are unaware that "struct sk_buff" and
  		 * other overheads allocate from the receive buffer
  		 * during socket buffer allocation.
  		 *
  		 * And after considering the possible alternatives,
  		 * returning the value we actually used in getsockopt
  		 * is the most desirable behavior.
  		 */
  		sk->sk_rcvbuf = max_t(u32, val * 2, SOCK_MIN_RCVBUF);
  		break;
  
  	case SO_RCVBUFFORCE:
  		if (!capable(CAP_NET_ADMIN)) {
  			ret = -EPERM;
  			break;
  		}
  		goto set_rcvbuf;
  
  	case SO_KEEPALIVE:
  #ifdef CONFIG_INET
  		if (sk->sk_protocol == IPPROTO_TCP &&
  		    sk->sk_type == SOCK_STREAM)
  			tcp_set_keepalive(sk, valbool);
  #endif
  		sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
  		break;
  
  	case SO_OOBINLINE:
  		sock_valbool_flag(sk, SOCK_URGINLINE, valbool);
  		break;
  
  	case SO_NO_CHECK:
  		sk->sk_no_check = valbool;
  		break;
  
  	case SO_PRIORITY:
  		if ((val >= 0 && val <= 6) ||
  		    ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
  			sk->sk_priority = val;
  		else
  			ret = -EPERM;
  		break;
  
  	case SO_LINGER:
  		if (optlen < sizeof(ling)) {
  			ret = -EINVAL;	/* 1003.1g */
  			break;
  		}
  		if (copy_from_user(&ling, optval, sizeof(ling))) {
  			ret = -EFAULT;
  			break;
  		}
  		if (!ling.l_onoff)
  			sock_reset_flag(sk, SOCK_LINGER);
  		else {
  #if (BITS_PER_LONG == 32)
  			if ((unsigned int)ling.l_linger >= MAX_SCHEDULE_TIMEOUT/HZ)
  				sk->sk_lingertime = MAX_SCHEDULE_TIMEOUT;
  			else
  #endif
  				sk->sk_lingertime = (unsigned int)ling.l_linger * HZ;
  			sock_set_flag(sk, SOCK_LINGER);
  		}
  		break;
  
  	case SO_BSDCOMPAT:
  		sock_warn_obsolete_bsdism("setsockopt");
  		break;
  
  	case SO_PASSCRED:
  		if (valbool)
  			set_bit(SOCK_PASSCRED, &sock->flags);
  		else
  			clear_bit(SOCK_PASSCRED, &sock->flags);
  		break;
  
  	case SO_TIMESTAMP:
  	case SO_TIMESTAMPNS:
  		if (valbool)  {
  			if (optname == SO_TIMESTAMP)
  				sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
  			else
  				sock_set_flag(sk, SOCK_RCVTSTAMPNS);
  			sock_set_flag(sk, SOCK_RCVTSTAMP);
  			sock_enable_timestamp(sk, SOCK_TIMESTAMP);
  		} else {
  			sock_reset_flag(sk, SOCK_RCVTSTAMP);
  			sock_reset_flag(sk, SOCK_RCVTSTAMPNS);
  		}
  		break;
  
  	case SO_TIMESTAMPING:
  		if (val & ~SOF_TIMESTAMPING_MASK) {
  			ret = -EINVAL;
  			break;
  		}
  		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE,
  				  val & SOF_TIMESTAMPING_TX_HARDWARE);
  		sock_valbool_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE,
  				  val & SOF_TIMESTAMPING_TX_SOFTWARE);
  		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE,
  				  val & SOF_TIMESTAMPING_RX_HARDWARE);
  		if (val & SOF_TIMESTAMPING_RX_SOFTWARE)
  			sock_enable_timestamp(sk,
  					      SOCK_TIMESTAMPING_RX_SOFTWARE);
  		else
  			sock_disable_timestamp(sk,
  					       (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE));
  		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SOFTWARE,
  				  val & SOF_TIMESTAMPING_SOFTWARE);
  		sock_valbool_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE,
  				  val & SOF_TIMESTAMPING_SYS_HARDWARE);
  		sock_valbool_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE,
  				  val & SOF_TIMESTAMPING_RAW_HARDWARE);
  		break;
  
  	case SO_RCVLOWAT:
  		if (val < 0)
  			val = INT_MAX;
  		sk->sk_rcvlowat = val ? : 1;
  		break;
  
  	case SO_RCVTIMEO:
  		ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
  		break;
  
  	case SO_SNDTIMEO:
  		ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
  		break;
  
  	case SO_ATTACH_FILTER:
  		ret = -EINVAL;
  		if (optlen == sizeof(struct sock_fprog)) {
  			struct sock_fprog fprog;
  
  			ret = -EFAULT;
  			if (copy_from_user(&fprog, optval, sizeof(fprog)))
  				break;
  
  			ret = sk_attach_filter(&fprog, sk);
  		}
  		break;
  
  	case SO_DETACH_FILTER:
  		ret = sk_detach_filter(sk);
  		break;
  
  	case SO_LOCK_FILTER:
  		if (sock_flag(sk, SOCK_FILTER_LOCKED) && !valbool)
  			ret = -EPERM;
  		else
  			sock_valbool_flag(sk, SOCK_FILTER_LOCKED, valbool);
  		break;
  
  	case SO_PASSSEC:
  		if (valbool)
  			set_bit(SOCK_PASSSEC, &sock->flags);
  		else
  			clear_bit(SOCK_PASSSEC, &sock->flags);
  		break;
  	case SO_MARK:
  		if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN))
  			ret = -EPERM;
  		else
  			sk->sk_mark = val;
  		break;
  
  		/* We implement the SO_SNDLOWAT etc to
  		   not be settable (1003.1g 5.3) */
  	case SO_RXQ_OVFL:
  		sock_valbool_flag(sk, SOCK_RXQ_OVFL, valbool);
  		break;
  
  	case SO_WIFI_STATUS:
  		sock_valbool_flag(sk, SOCK_WIFI_STATUS, valbool);
  		break;
  
  	case SO_PEEK_OFF:
  		if (sock->ops->set_peek_off)
  			ret = sock->ops->set_peek_off(sk, val);
  		else
  			ret = -EOPNOTSUPP;
  		break;
  
  	case SO_NOFCS:
  		sock_valbool_flag(sk, SOCK_NOFCS, valbool);
  		break;
  
  	case SO_SELECT_ERR_QUEUE:
  		sock_valbool_flag(sk, SOCK_SELECT_ERR_QUEUE, valbool);
  		break;
  
  	default:
  		ret = -ENOPROTOOPT;
  		break;
  	}
  	release_sock(sk);
  	return ret;
  }
  EXPORT_SYMBOL(sock_setsockopt);
  
  
  void cred_to_ucred(struct pid *pid, const struct cred *cred,
  		   struct ucred *ucred)
  {
  	ucred->pid = pid_vnr(pid);
  	ucred->uid = ucred->gid = -1;
  	if (cred) {
  		struct user_namespace *current_ns = current_user_ns();
  
  		ucred->uid = from_kuid_munged(current_ns, cred->euid);
  		ucred->gid = from_kgid_munged(current_ns, cred->egid);
  	}
  }
  EXPORT_SYMBOL_GPL(cred_to_ucred);
  
  int sock_getsockopt(struct socket *sock, int level, int optname,
  		    char __user *optval, int __user *optlen)
  {
  	struct sock *sk = sock->sk;
  
  	union {
  		int val;
  		struct linger ling;
  		struct timeval tm;
  	} v;
  
  	int lv = sizeof(int);
  	int len;
  
  	if (get_user(len, optlen))
  		return -EFAULT;
  	if (len < 0)
  		return -EINVAL;
  
  	memset(&v, 0, sizeof(v));
  
  	switch (optname) {
  	case SO_DEBUG:
  		v.val = sock_flag(sk, SOCK_DBG);
  		break;
  
  	case SO_DONTROUTE:
  		v.val = sock_flag(sk, SOCK_LOCALROUTE);
  		break;
  
  	case SO_BROADCAST:
  		v.val = sock_flag(sk, SOCK_BROADCAST);
  		break;
  
  	case SO_SNDBUF:
  		v.val = sk->sk_sndbuf;
  		break;
  
  	case SO_RCVBUF:
  		v.val = sk->sk_rcvbuf;
  		break;
  
  	case SO_REUSEADDR:
  		v.val = sk->sk_reuse;
  		break;
  
  	case SO_REUSEPORT:
  		v.val = sk->sk_reuseport;
  		break;
  
  	case SO_KEEPALIVE:
  		v.val = sock_flag(sk, SOCK_KEEPOPEN);
  		break;
  
  	case SO_TYPE:
  		v.val = sk->sk_type;
  		break;
  
  	case SO_PROTOCOL:
  		v.val = sk->sk_protocol;
  		break;
  
  	case SO_DOMAIN:
  		v.val = sk->sk_family;
  		break;
  
  	case SO_ERROR:
  		v.val = -sock_error(sk);
  		if (v.val == 0)
  			v.val = xchg(&sk->sk_err_soft, 0);
  		break;
  
  	case SO_OOBINLINE:
  		v.val = sock_flag(sk, SOCK_URGINLINE);
  		break;
  
  	case SO_NO_CHECK:
  		v.val = sk->sk_no_check;
  		break;
  
  	case SO_PRIORITY:
  		v.val = sk->sk_priority;
  		break;
  
  	case SO_LINGER:
  		lv		= sizeof(v.ling);
  		v.ling.l_onoff	= sock_flag(sk, SOCK_LINGER);
  		v.ling.l_linger	= sk->sk_lingertime / HZ;
  		break;
  
  	case SO_BSDCOMPAT:
  		sock_warn_obsolete_bsdism("getsockopt");
  		break;
  
  	case SO_TIMESTAMP:
  		v.val = sock_flag(sk, SOCK_RCVTSTAMP) &&
  				!sock_flag(sk, SOCK_RCVTSTAMPNS);
  		break;
  
  	case SO_TIMESTAMPNS:
  		v.val = sock_flag(sk, SOCK_RCVTSTAMPNS);
  		break;
  
  	case SO_TIMESTAMPING:
  		v.val = 0;
  		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_HARDWARE))
  			v.val |= SOF_TIMESTAMPING_TX_HARDWARE;
  		if (sock_flag(sk, SOCK_TIMESTAMPING_TX_SOFTWARE))
  			v.val |= SOF_TIMESTAMPING_TX_SOFTWARE;
  		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_HARDWARE))
  			v.val |= SOF_TIMESTAMPING_RX_HARDWARE;
  		if (sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE))
  			v.val |= SOF_TIMESTAMPING_RX_SOFTWARE;
  		if (sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE))
  			v.val |= SOF_TIMESTAMPING_SOFTWARE;
  		if (sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))
  			v.val |= SOF_TIMESTAMPING_SYS_HARDWARE;
  		if (sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE))
  			v.val |= SOF_TIMESTAMPING_RAW_HARDWARE;
  		break;
  
  	case SO_RCVTIMEO:
  		lv = sizeof(struct timeval);
  		if (sk->sk_rcvtimeo == MAX_SCHEDULE_TIMEOUT) {
  			v.tm.tv_sec = 0;
  			v.tm.tv_usec = 0;
  		} else {
  			v.tm.tv_sec = sk->sk_rcvtimeo / HZ;
  			v.tm.tv_usec = ((sk->sk_rcvtimeo % HZ) * 1000000) / HZ;
  		}
  		break;
  
  	case SO_SNDTIMEO:
  		lv = sizeof(struct timeval);
  		if (sk->sk_sndtimeo == MAX_SCHEDULE_TIMEOUT) {
  			v.tm.tv_sec = 0;
  			v.tm.tv_usec = 0;
  		} else {
  			v.tm.tv_sec = sk->sk_sndtimeo / HZ;
  			v.tm.tv_usec = ((sk->sk_sndtimeo % HZ) * 1000000) / HZ;
  		}
  		break;
  
  	case SO_RCVLOWAT:
  		v.val = sk->sk_rcvlowat;
  		break;
  
  	case SO_SNDLOWAT:
  		v.val = 1;
  		break;
  
  	case SO_PASSCRED:
  		v.val = !!test_bit(SOCK_PASSCRED, &sock->flags);
  		break;
  
  	case SO_PEERCRED:
  	{
  		struct ucred peercred;
  		if (len > sizeof(peercred))
  			len = sizeof(peercred);
  		cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
  		if (copy_to_user(optval, &peercred, len))
  			return -EFAULT;
  		goto lenout;
  	}
  
  	case SO_PEERNAME:
  	{
  		char address[128];
  
  		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
  			return -ENOTCONN;
  		if (lv < len)
  			return -EINVAL;
  		if (copy_to_user(optval, address, len))
  			return -EFAULT;
  		goto lenout;
  	}
  
  	/* Dubious BSD thing... Probably nobody even uses it, but
  	 * the UNIX standard wants it for whatever reason... -DaveM
  	 */
  	case SO_ACCEPTCONN:
  		v.val = sk->sk_state == TCP_LISTEN;
  		break;
  
  	case SO_PASSSEC:
  		v.val = !!test_bit(SOCK_PASSSEC, &sock->flags);
  		break;
  
  	case SO_PEERSEC:
  		return security_socket_getpeersec_stream(sock, optval, optlen, len);
  
  	case SO_MARK:
  		v.val = sk->sk_mark;
  		break;
  
  	case SO_RXQ_OVFL:
  		v.val = sock_flag(sk, SOCK_RXQ_OVFL);
  		break;
  
  	case SO_WIFI_STATUS:
  		v.val = sock_flag(sk, SOCK_WIFI_STATUS);
  		break;
  
  	case SO_PEEK_OFF:
  		if (!sock->ops->set_peek_off)
  			return -EOPNOTSUPP;
  
  		v.val = sk->sk_peek_off;
  		break;
  	case SO_NOFCS:
  		v.val = sock_flag(sk, SOCK_NOFCS);
  		break;
  
  	case SO_BINDTODEVICE:
  		return sock_getbindtodevice(sk, optval, optlen, len);
  
  	case SO_GET_FILTER:
  		len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
  		if (len < 0)
  			return len;
  
  		goto lenout;
  
  	case SO_LOCK_FILTER:
  		v.val = sock_flag(sk, SOCK_FILTER_LOCKED);
  		break;
  
  	case SO_SELECT_ERR_QUEUE:
  		v.val = sock_flag(sk, SOCK_SELECT_ERR_QUEUE);
  		break;
  
  	default:
  		return -ENOPROTOOPT;
  	}
  
  	if (len > lv)
  		len = lv;
  	if (copy_to_user(optval, &v, len))
  		return -EFAULT;
  lenout:
  	if (put_user(len, optlen))
  		return -EFAULT;
  	return 0;
  }
  
  /*
   * Initialize an sk_lock.
   *
   * (We also register the sk_lock with the lock validator.)
   */
  static inline void sock_lock_init(struct sock *sk)
  {
  	sock_lock_init_class_and_name(sk,
  			af_family_slock_key_strings[sk->sk_family],
  			af_family_slock_keys + sk->sk_family,
  			af_family_key_strings[sk->sk_family],
  			af_family_keys + sk->sk_family);
  }
  
  /*
   * Copy all fields from osk to nsk but nsk->sk_refcnt must not change yet,
   * even temporarly, because of RCU lookups. sk_node should also be left as is.
   * We must not copy fields between sk_dontcopy_begin and sk_dontcopy_end
   */
  static void sock_copy(struct sock *nsk, const struct sock *osk)
  {
  #ifdef CONFIG_SECURITY_NETWORK
  	void *sptr = nsk->sk_security;
  #endif
  	memcpy(nsk, osk, offsetof(struct sock, sk_dontcopy_begin));
  
  	memcpy(&nsk->sk_dontcopy_end, &osk->sk_dontcopy_end,
  	       osk->sk_prot->obj_size - offsetof(struct sock, sk_dontcopy_end));
  
  #ifdef CONFIG_SECURITY_NETWORK
  	nsk->sk_security = sptr;
  	security_sk_clone(osk, nsk);
  #endif
  }
  
  void sk_prot_clear_portaddr_nulls(struct sock *sk, int size)
  {
  	unsigned long nulls1, nulls2;
  
  	nulls1 = offsetof(struct sock, __sk_common.skc_node.next);
  	nulls2 = offsetof(struct sock, __sk_common.skc_portaddr_node.next);
  	if (nulls1 > nulls2)
  		swap(nulls1, nulls2);
  
  	if (nulls1 != 0)
  		memset((char *)sk, 0, nulls1);
  	memset((char *)sk + nulls1 + sizeof(void *), 0,
  	       nulls2 - nulls1 - sizeof(void *));
  	memset((char *)sk + nulls2 + sizeof(void *), 0,
  	       size - nulls2 - sizeof(void *));
  }
  EXPORT_SYMBOL(sk_prot_clear_portaddr_nulls);
  
  static struct sock *sk_prot_alloc(struct proto *prot, gfp_t priority,
  		int family)
  {
  	struct sock *sk;
  	struct kmem_cache *slab;
  
  	slab = prot->slab;
  	if (slab != NULL) {
  		sk = kmem_cache_alloc(slab, priority & ~__GFP_ZERO);
  		if (!sk)
  			return sk;
  		if (priority & __GFP_ZERO) {
  			if (prot->clear_sk)
  				prot->clear_sk(sk, prot->obj_size);
  			else
  				sk_prot_clear_nulls(sk, prot->obj_size);
  		}
  	} else
  		sk = kmalloc(prot->obj_size, priority);
  
  	if (sk != NULL) {
  		kmemcheck_annotate_bitfield(sk, flags);
  
  		if (security_sk_alloc(sk, family, priority))
  			goto out_free;
  
  		if (!try_module_get(prot->owner))
  			goto out_free_sec;
  		sk_tx_queue_clear(sk);
  	}
  
  	return sk;
  
  out_free_sec:
  	security_sk_free(sk);
  out_free:
  	if (slab != NULL)
  		kmem_cache_free(slab, sk);
  	else
  		kfree(sk);
  	return NULL;
  }
  
  static void sk_prot_free(struct proto *prot, struct sock *sk)
  {
  	struct kmem_cache *slab;
  	struct module *owner;
  
  	owner = prot->owner;
  	slab = prot->slab;
  
  	security_sk_free(sk);
  	if (slab != NULL)
  		kmem_cache_free(slab, sk);
  	else
  		kfree(sk);
  	module_put(owner);
  }
  
  #if IS_ENABLED(CONFIG_NET_CLS_CGROUP)
  void sock_update_classid(struct sock *sk)
  {
  	u32 classid;
  
  	classid = task_cls_classid(current);
  	if (classid != sk->sk_classid)
  		sk->sk_classid = classid;
  }
  EXPORT_SYMBOL(sock_update_classid);
  #endif
  
  #if IS_ENABLED(CONFIG_NETPRIO_CGROUP)
  void sock_update_netprioidx(struct sock *sk)
  {
  	if (in_interrupt())
  		return;
  
  	sk->sk_cgrp_prioidx = task_netprioidx(current);
  }
  EXPORT_SYMBOL_GPL(sock_update_netprioidx);
  #endif
  
  /**
   *	sk_alloc - All socket objects are allocated here
   *	@net: the applicable net namespace
   *	@family: protocol family
   *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
   *	@prot: struct proto associated with this new sock instance
   */
  struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
  		      struct proto *prot)
  {
  	struct sock *sk;
  
  	sk = sk_prot_alloc(prot, priority | __GFP_ZERO, family);
  	if (sk) {
  		sk->sk_family = family;
  		/*
  		 * See comment in struct sock definition to understand
  		 * why we need sk_prot_creator -acme
  		 */
  		sk->sk_prot = sk->sk_prot_creator = prot;
  		sock_lock_init(sk);
  		sock_net_set(sk, get_net(net));
  		atomic_set(&sk->sk_wmem_alloc, 1);
  
  		sock_update_classid(sk);
  		sock_update_netprioidx(sk);
  	}
  
  	return sk;
  }
  EXPORT_SYMBOL(sk_alloc);
  
  static void __sk_free(struct sock *sk)
  {
  	struct sk_filter *filter;
  
  	if (sk->sk_destruct)
  		sk->sk_destruct(sk);
  
  	filter = rcu_dereference_check(sk->sk_filter,
  				       atomic_read(&sk->sk_wmem_alloc) == 0);
  	if (filter) {
  		sk_filter_uncharge(sk, filter);
  		RCU_INIT_POINTER(sk->sk_filter, NULL);
  	}
  
  	sock_disable_timestamp(sk, SK_FLAGS_TIMESTAMP);
  
  	if (atomic_read(&sk->sk_omem_alloc))
  		pr_debug("%s: optmem leakage (%d bytes) detected\n",
  			 __func__, atomic_read(&sk->sk_omem_alloc));
  
  	if (sk->sk_peer_cred)
  		put_cred(sk->sk_peer_cred);
  	put_pid(sk->sk_peer_pid);
  	put_net(sock_net(sk));
  	sk_prot_free(sk->sk_prot_creator, sk);
  }
  
  void sk_free(struct sock *sk)
  {
  	/*
  	 * We subtract one from sk_wmem_alloc and can know if
  	 * some packets are still in some tx queue.
  	 * If not null, sock_wfree() will call __sk_free(sk) later
  	 */
  	if (atomic_dec_and_test(&sk->sk_wmem_alloc))
  		__sk_free(sk);
  }
  EXPORT_SYMBOL(sk_free);
  
  /*
   * Last sock_put should drop reference to sk->sk_net. It has already
   * been dropped in sk_change_net. Taking reference to stopping namespace
   * is not an option.
   * Take reference to a socket to remove it from hash _alive_ and after that
   * destroy it in the context of init_net.
   */
  void sk_release_kernel(struct sock *sk)
  {
  	if (sk == NULL || sk->sk_socket == NULL)
  		return;
  
  	sock_hold(sk);
  	sock_release(sk->sk_socket);
  	release_net(sock_net(sk));
  	sock_net_set(sk, get_net(&init_net));
  	sock_put(sk);
  }
  EXPORT_SYMBOL(sk_release_kernel);
  
  static void sk_update_clone(const struct sock *sk, struct sock *newsk)
  {
  	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
  		sock_update_memcg(newsk);
  }
  
  /**
   *	sk_clone_lock - clone a socket, and lock its clone
   *	@sk: the socket to clone
   *	@priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
   *
   *	Caller must unlock socket even in error path (bh_unlock_sock(newsk))
   */
  struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority)
  {
  	struct sock *newsk;
  
  	newsk = sk_prot_alloc(sk->sk_prot, priority, sk->sk_family);
  	if (newsk != NULL) {
  		struct sk_filter *filter;
  
  		sock_copy(newsk, sk);
  
  		/* SANITY */
  		get_net(sock_net(newsk));
  		sk_node_init(&newsk->sk_node);
  		sock_lock_init(newsk);
  		bh_lock_sock(newsk);
  		newsk->sk_backlog.head	= newsk->sk_backlog.tail = NULL;
  		newsk->sk_backlog.len = 0;
  
  		atomic_set(&newsk->sk_rmem_alloc, 0);
  		/*
  		 * sk_wmem_alloc set to one (see sk_free() and sock_wfree())
  		 */
  		atomic_set(&newsk->sk_wmem_alloc, 1);
  		atomic_set(&newsk->sk_omem_alloc, 0);
  		skb_queue_head_init(&newsk->sk_receive_queue);
  		skb_queue_head_init(&newsk->sk_write_queue);
  #ifdef CONFIG_NET_DMA
  		skb_queue_head_init(&newsk->sk_async_wait_queue);
  #endif
  
  		spin_lock_init(&newsk->sk_dst_lock);
  		rwlock_init(&newsk->sk_callback_lock);
  		lockdep_set_class_and_name(&newsk->sk_callback_lock,
  				af_callback_keys + newsk->sk_family,
  				af_family_clock_key_strings[newsk->sk_family]);
  
  		newsk->sk_dst_cache	= NULL;
  		newsk->sk_wmem_queued	= 0;
  		newsk->sk_forward_alloc = 0;
  		newsk->sk_send_head	= NULL;
  		newsk->sk_userlocks	= sk->sk_userlocks & ~SOCK_BINDPORT_LOCK;
  
  		sock_reset_flag(newsk, SOCK_DONE);
  		skb_queue_head_init(&newsk->sk_error_queue);
  
  		filter = rcu_dereference_protected(newsk->sk_filter, 1);
  		if (filter != NULL)
  			sk_filter_charge(newsk, filter);
  
  		if (unlikely(xfrm_sk_clone_policy(newsk))) {
  			/* It is still raw copy of parent, so invalidate
  			 * destructor and make plain sk_free() */
  			newsk->sk_destruct = NULL;
  			bh_unlock_sock(newsk);
  			sk_free(newsk);
  			newsk = NULL;
  			goto out;
  		}
  
  		newsk->sk_err	   = 0;
  		newsk->sk_priority = 0;
  		/*
  		 * Before updating sk_refcnt, we must commit prior changes to memory
  		 * (Documentation/RCU/rculist_nulls.txt for details)
  		 */
  		smp_wmb();
  		atomic_set(&newsk->sk_refcnt, 2);
  
  		/*
  		 * Increment the counter in the same struct proto as the master
  		 * sock (sk_refcnt_debug_inc uses newsk->sk_prot->socks, that
  		 * is the same as sk->sk_prot->socks, as this field was copied
  		 * with memcpy).
  		 *
  		 * This _changes_ the previous behaviour, where
  		 * tcp_create_openreq_child always was incrementing the
  		 * equivalent to tcp_prot->socks (inet_sock_nr), so this have
  		 * to be taken into account in all callers. -acme
  		 */
  		sk_refcnt_debug_inc(newsk);
  		sk_set_socket(newsk, NULL);
  		newsk->sk_wq = NULL;
  
  		sk_update_clone(sk, newsk);
  
  		if (newsk->sk_prot->sockets_allocated)
  			sk_sockets_allocated_inc(newsk);
  
  		if (newsk->sk_flags & SK_FLAGS_TIMESTAMP)
  			net_enable_timestamp();
  	}
  out:
  	return newsk;
  }
  EXPORT_SYMBOL_GPL(sk_clone_lock);
  
  void sk_setup_caps(struct sock *sk, struct dst_entry *dst)
  {
  	__sk_dst_set(sk, dst);
  	sk->sk_route_caps = dst->dev->features;
  	if (sk->sk_route_caps & NETIF_F_GSO)
  		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
  	sk->sk_route_caps &= ~sk->sk_route_nocaps;
  	if (sk_can_gso(sk)) {
  		if (dst->header_len) {
  			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
  		} else {
  			sk->sk_route_caps |= NETIF_F_SG | NETIF_F_HW_CSUM;
  			sk->sk_gso_max_size = dst->dev->gso_max_size;
  			sk->sk_gso_max_segs = dst->dev->gso_max_segs;
  		}
  	}
  }
  EXPORT_SYMBOL_GPL(sk_setup_caps);
  
  /*
   *	Simple resource managers for sockets.
   */
  
  
  /*
   * Write buffer destructor automatically called from kfree_skb.
   */
  void sock_wfree(struct sk_buff *skb)
  {
  	struct sock *sk = skb->sk;
  	unsigned int len = skb->truesize;
  
  	if (!sock_flag(sk, SOCK_USE_WRITE_QUEUE)) {
  		/*
  		 * Keep a reference on sk_wmem_alloc, this will be released
  		 * after sk_write_space() call
  		 */
  		atomic_sub(len - 1, &sk->sk_wmem_alloc);
  		sk->sk_write_space(sk);
  		len = 1;
  	}
  	/*
  	 * if sk_wmem_alloc reaches 0, we must finish what sk_free()
  	 * could not do because of in-flight packets
  	 */
  	if (atomic_sub_and_test(len, &sk->sk_wmem_alloc))
  		__sk_free(sk);
  }
  EXPORT_SYMBOL(sock_wfree);
  
  /*
   * Read buffer destructor automatically called from kfree_skb.
   */
  void sock_rfree(struct sk_buff *skb)
  {
  	struct sock *sk = skb->sk;
  	unsigned int len = skb->truesize;
  
  	atomic_sub(len, &sk->sk_rmem_alloc);
  	sk_mem_uncharge(sk, len);
  }
  EXPORT_SYMBOL(sock_rfree);
  
  void sock_edemux(struct sk_buff *skb)
  {
  	struct sock *sk = skb->sk;
  
  #ifdef CONFIG_INET
  	if (sk->sk_state == TCP_TIME_WAIT)
  		inet_twsk_put(inet_twsk(sk));
  	else
  #endif
  		sock_put(sk);
  }
  EXPORT_SYMBOL(sock_edemux);
  
  kuid_t sock_i_uid(struct sock *sk)
  {
  	kuid_t uid;
  	
  	/*mtk_net: fix kernel bug*/
  	if (!sk) {
  		pr_info("sk == NULL for sock_i_uid\n");
  		return GLOBAL_ROOT_UID;
  	}
  	
  	read_lock_bh(&sk->sk_callback_lock);
  	uid = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_uid : GLOBAL_ROOT_UID;
  	read_unlock_bh(&sk->sk_callback_lock);
  	return uid;
  }
  EXPORT_SYMBOL(sock_i_uid);
  
  unsigned long sock_i_ino(struct sock *sk)
  {
  	unsigned long ino;
  
  	read_lock_bh(&sk->sk_callback_lock);
  	ino = sk->sk_socket ? SOCK_INODE(sk->sk_socket)->i_ino : 0;
  	read_unlock_bh(&sk->sk_callback_lock);
  	return ino;
  }
  EXPORT_SYMBOL(sock_i_ino);
  
  /*
   * Allocate a skb from the socket's send buffer.
   */
  struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
  			     gfp_t priority)
  {
  	if (force || atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
  		struct sk_buff *skb = alloc_skb(size, priority);
  		if (skb) {
  			skb_set_owner_w(skb, sk);
  			return skb;
  		}
  	}
  	return NULL;
  }
  EXPORT_SYMBOL(sock_wmalloc);
  
  /*
   * Allocate a skb from the socket's receive buffer.
   */
  struct sk_buff *sock_rmalloc(struct sock *sk, unsigned long size, int force,
  			     gfp_t priority)
  {
  	if (force || atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf) {
  		struct sk_buff *skb = alloc_skb(size, priority);
  		if (skb) {
  			skb_set_owner_r(skb, sk);
  			return skb;
  		}
  	}
  	return NULL;
  }
  
  /*
   * Allocate a memory block from the socket's option memory buffer.
   */
  void *sock_kmalloc(struct sock *sk, int size, gfp_t priority)
  {
  	if ((unsigned int)size <= sysctl_optmem_max &&
  	    atomic_read(&sk->sk_omem_alloc) + size < sysctl_optmem_max) {
  		void *mem;
  		/* First do the add, to avoid the race if kmalloc
  		 * might sleep.
  		 */
  		atomic_add(size, &sk->sk_omem_alloc);
  		mem = kmalloc(size, priority);
  		if (mem)
  			return mem;
  		atomic_sub(size, &sk->sk_omem_alloc);
  	}
  	return NULL;
  }
  EXPORT_SYMBOL(sock_kmalloc);
  
  /*
   * Free an option memory block.
   */
  void sock_kfree_s(struct sock *sk, void *mem, int size)
  {
  	kfree(mem);
  	atomic_sub(size, &sk->sk_omem_alloc);
  }
  EXPORT_SYMBOL(sock_kfree_s);
  
  /* It is almost wait_for_tcp_memory minus release_sock/lock_sock.
     I think, these locks should be removed for datagram sockets.
   */
  static long sock_wait_for_wmem(struct sock *sk, long timeo)
  {
  	DEFINE_WAIT(wait);
  
  	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
  	for (;;) {
  		if (!timeo)
  			break;
  		if (signal_pending(current))
  			break;
  		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
  		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
  		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf)
  			break;
  		if (sk->sk_shutdown & SEND_SHUTDOWN)
  			break;
  		if (sk->sk_err)
  			break;
  		timeo = schedule_timeout(timeo);
  	}
  	finish_wait(sk_sleep(sk), &wait);
  	return timeo;
  }
  
  
  //debug funcion
  
  static int sock_dump_info(struct sock *sk)
  {
      //dump receiver queue 128 bytes
      //struct sk_buff *skb;
      //char skbmsg[128];
      //dump receiver queue 128 bytes end
  
  		if(sk->sk_family == AF_UNIX)
  		{
  		  struct unix_sock *u = unix_sk(sk);
  		  struct sock *other = NULL;
  		  if( (u->path.dentry !=NULL)&&(u->path.dentry->d_iname!=NULL))
                    //if( (u->dentry !=NULL)&&(u->dentry->d_iname!=NULL))
  		  {
  		  	  #ifdef CONFIG_MTK_NET_LOGGING  
  		      printk(KERN_INFO "[mtk_net][sock]sockdbg: socket-Name:%s \n",u->path.dentry->d_iname);
  		      #endif
  		  }
  		   else
  		  {
  		  	   #ifdef CONFIG_MTK_NET_LOGGING  
                 printk(KERN_INFO "[mtk_net][sock]sockdbg:socket Name (NULL)\n" );
                 #endif
  		   }
  		   
  		   if(sk->sk_socket && SOCK_INODE(sk->sk_socket))
  		  {
  		   	  	#ifdef CONFIG_MTK_NET_LOGGING  
  		        printk(KERN_INFO "[mtk_net][sock]sockdbg:socket Inode[%lu]\n" ,SOCK_INODE(sk->sk_socket)->i_ino);
  		        #endif
  		   }		 
  
  		    other = unix_sk(sk)->peer ;
  			if (!other)
  			{
  				#ifdef CONFIG_MTK_NET_LOGGING  
  		        printk(KERN_INFO "[mtk_net][sock]sockdbg:peer is (NULL) \n");
  		        #endif
  			 } else{
  			 
  				if ((((struct unix_sock *)other)->path.dentry != NULL)&&(((struct unix_sock *)other)->path.dentry->d_iname != NULL))
                                  //if ((((struct unix_sock *)other)->dentry != NULL)&&(((struct unix_sock *)other)->dentry->d_iname != NULL))
  				{
  					#ifdef CONFIG_MTK_NET_LOGGING  
  		            printk(KERN_INFO "[mtk_net][sock]sockdbg: Peer Name:%s \n",((struct unix_sock *)other)->path.dentry->d_iname);
  		            #endif
  				 }				
  				else
  				{
  					#ifdef CONFIG_MTK_NET_LOGGING  
                      printk(KERN_INFO "[mtk_net][sock]sockdbg: Peer Name (NULL) \n");
                      #endif
  				}
  
  				if(other->sk_socket && SOCK_INODE(other->sk_socket))
  				   {
  					#ifdef CONFIG_MTK_NET_LOGGING  
  		            printk(KERN_INFO "[mtk_net][sock]sockdbg: Peer Inode [%lu] \n", SOCK_INODE(other->sk_socket)->i_ino);
  		            #endif
  				    }
  	            #ifdef CONFIG_MTK_NET_LOGGING  
  				printk(KERN_INFO "[mtk_net][sock]sockdbg: Peer Recieve Queue len:%d \n",other->sk_receive_queue.qlen);
                  #endif
  				 //dump receiver queue 128 bytes
  						/* if ((skb = skb_peek_tail(&other->sk_receive_queue)) == NULL) {
  		                        
  		                    printk(KERN_INFO "sockdbg: Peer Recieve Queue is null (warning) \n");
  						 }else{
  						       int i =0 ,len=0;
  		                      if((skb->len !=0) && (skb->data != NULL)){
  
  		                        if(skb->len >= 127){
  									len = 127 ;                          
  								 }else
  								 {
  		                           len = skb->len ;
  								 }
  		                        for (i=0;i<len;i++)
  								  sprintf(skbmsg+i, "%x", skb->data[i]);
  
  								skbmsg[len]= '\0' ;
  								
  		                        printk(KERN_INFO "sockdbg: Peer Recieve Queue dump(%d bytes):%s\n", len, skbmsg);
  												
  		                        
  							  }else{                
  		                        printk(KERN_INFO "sockdbg: Peer Recieve skb error \n");
  							  }*/
                       //dump receiver queue 128 bytes end      
  
  				 //}
  				//dump receiver queue 128 bytes end				 
  
  			 }
  		}
  
  		return 0 ;	  
  
  	
  }
  
  
  
  /*
   *	Generic send/receive buffer handlers
   */
  
  struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
  				     unsigned long data_len, int noblock,
  				     int *errcode)
  {
  	struct sk_buff *skb;
  	gfp_t gfp_mask;
  	long timeo;
  	int err;
  	int npages = (data_len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
  
  	err = -EMSGSIZE;
  	if (npages > MAX_SKB_FRAGS)
  		goto failure;
  
  	gfp_mask = sk->sk_allocation;
  	if (gfp_mask & __GFP_WAIT)
  		gfp_mask |= __GFP_REPEAT;
  
  	timeo = sock_sndtimeo(sk, noblock);
  	while (1) {
  		err = sock_error(sk);
  		if (err != 0)
  			goto failure;
  
  		err = -EPIPE;
  		if (sk->sk_shutdown & SEND_SHUTDOWN)
  			goto failure;
  
  		if (atomic_read(&sk->sk_wmem_alloc) < sk->sk_sndbuf) {
  			skb = alloc_skb(header_len, gfp_mask);
  			if (skb) {
  				int i;
  
  				/* No pages, we're done... */
  				if (!data_len)
  					break;
  
  				skb->truesize += data_len;
  				skb_shinfo(skb)->nr_frags = npages;
  				for (i = 0; i < npages; i++) {
  					struct page *page;
  
  					page = alloc_pages(sk->sk_allocation, 0);
  					if (!page) {
  						err = -ENOBUFS;
  						skb_shinfo(skb)->nr_frags = i;
  						kfree_skb(skb);
  						goto failure;
  					}
  
  					__skb_fill_page_desc(skb, i,
  							page, 0,
  							(data_len >= PAGE_SIZE ?
  							 PAGE_SIZE :
  							 data_len));
  					data_len -= PAGE_SIZE;
  				}
  
  				/* Full success... */
  				break;
  			}
  			err = -ENOBUFS;
  			goto failure;
  		}
  		set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
  		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
  		err = -EAGAIN;
  		if (!timeo)
  			goto failure;
  		if (signal_pending(current))
  			goto interrupted;
  
          sock_dump_info(sk);
          #ifdef CONFIG_MTK_NET_LOGGING  
  		printk(KERN_INFO "[mtk_net][sock]sockdbg: wait_for_wmem, timeo =%ld, wmem =%d, snd buf =%d \n",
  			 timeo, atomic_read(&sk->sk_wmem_alloc), sk->sk_sndbuf); 
          #endif
  		timeo = sock_wait_for_wmem(sk, timeo);
  		#ifdef CONFIG_MTK_NET_LOGGING  
  		printk(KERN_INFO "[mtk_net][sock]sockdbg: wait_for_wmem done, header_len=0x%lx, data_len=0x%lx,timeo =%ld \n",
  			 header_len, data_len ,timeo);
  	    #endif
  	}
  
  	skb_set_owner_w(skb, sk);
  	return skb;
  
  interrupted:
  	err = sock_intr_errno(timeo);
  failure:
  	*errcode = err;
  	return NULL;
  }
  EXPORT_SYMBOL(sock_alloc_send_pskb);
  
  struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
  				    int noblock, int *errcode)
  {
  	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode);
  }
  EXPORT_SYMBOL(sock_alloc_send_skb);
  
  /* On 32bit arches, an skb frag is limited to 2^15 */
  #define SKB_FRAG_PAGE_ORDER	get_order(32768)
  
  bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag)
  {
  	int order;
  
  	if (pfrag->page) {
  		if (atomic_read(&pfrag->page->_count) == 1) {
  			pfrag->offset = 0;
  			return true;
  		}
  		if (pfrag->offset < pfrag->size)
  			return true;
  		put_page(pfrag->page);
  	}
  
  	/* We restrict high order allocations to users that can afford to wait */
  	order = (sk->sk_allocation & __GFP_WAIT) ? SKB_FRAG_PAGE_ORDER : 0;
  
  	do {
  		gfp_t gfp = sk->sk_allocation;
  
  		if (order)
  			gfp |= __GFP_COMP | __GFP_NOWARN | __GFP_NORETRY;
  		pfrag->page = alloc_pages(gfp, order);
  		if (likely(pfrag->page)) {
  			pfrag->offset = 0;
  			pfrag->size = PAGE_SIZE << order;
  			return true;
  		}
  	} while (--order >= 0);
  
  	sk_enter_memory_pressure(sk);
  	sk_stream_moderate_sndbuf(sk);
  	return false;
  }
  EXPORT_SYMBOL(sk_page_frag_refill);
  
  static void __lock_sock(struct sock *sk)
  	__releases(&sk->sk_lock.slock)
  	__acquires(&sk->sk_lock.slock)
  {
  	DEFINE_WAIT(wait);
  
  	for (;;) {
  		prepare_to_wait_exclusive(&sk->sk_lock.wq, &wait,
  					TASK_UNINTERRUPTIBLE);
  		spin_unlock_bh(&sk->sk_lock.slock);
  		schedule();
  		spin_lock_bh(&sk->sk_lock.slock);
  		if (!sock_owned_by_user(sk))
  			break;
  	}
  	finish_wait(&sk->sk_lock.wq, &wait);
  }
  
  static void __release_sock(struct sock *sk)
  	__releases(&sk->sk_lock.slock)
  	__acquires(&sk->sk_lock.slock)
  {
  	struct sk_buff *skb = sk->sk_backlog.head;
  
  	do {
  		sk->sk_backlog.head = sk->sk_backlog.tail = NULL;
  		bh_unlock_sock(sk);
  
  		do {
  			struct sk_buff *next = skb->next;
  
  			prefetch(next);
  			WARN_ON_ONCE(skb_dst_is_noref(skb));
  			skb->next = NULL;
  			sk_backlog_rcv(sk, skb);
  
  			/*
  			 * We are in process context here with softirqs
  			 * disabled, use cond_resched_softirq() to preempt.
  			 * This is safe to do because we've taken the backlog
  			 * queue private:
  			 */
  			cond_resched_softirq();
  
  			skb = next;
  		} while (skb != NULL);
  
  		bh_lock_sock(sk);
  	} while ((skb = sk->sk_backlog.head) != NULL);
  
  	/*
  	 * Doing the zeroing here guarantee we can not loop forever
  	 * while a wild producer attempts to flood us.
  	 */
  	sk->sk_backlog.len = 0;
  }
  
  /**
   * sk_wait_data - wait for data to arrive at sk_receive_queue
   * @sk:    sock to wait on
   * @timeo: for how long
   *
   * Now socket state including sk->sk_err is changed only under lock,
   * hence we may omit checks after joining wait queue.
   * We check receive queue before schedule() only as optimization;
   * it is very likely that release_sock() added new data.
   */
  int sk_wait_data(struct sock *sk, long *timeo)
  {
  	int rc;
  	DEFINE_WAIT(wait);
  
  	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
  	set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
  	rc = sk_wait_event(sk, timeo, !skb_queue_empty(&sk->sk_receive_queue));
  	clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
  	finish_wait(sk_sleep(sk), &wait);
  	return rc;
  }
  EXPORT_SYMBOL(sk_wait_data);
  
  /**
   *	__sk_mem_schedule - increase sk_forward_alloc and memory_allocated
   *	@sk: socket
   *	@size: memory size to allocate
   *	@kind: allocation type
   *
   *	If kind is SK_MEM_SEND, it means wmem allocation. Otherwise it means
   *	rmem allocation. This function assumes that protocols which have
   *	memory_pressure use sk_wmem_queued as write buffer accounting.
   */
  int __sk_mem_schedule(struct sock *sk, int size, int kind)
  {
  	struct proto *prot = sk->sk_prot;
  	int amt = sk_mem_pages(size);
  	long allocated;
  	int parent_status = UNDER_LIMIT;
  
  	sk->sk_forward_alloc += amt * SK_MEM_QUANTUM;
  
  	allocated = sk_memory_allocated_add(sk, amt, &parent_status);
  
  	/* Under limit. */
  	if (parent_status == UNDER_LIMIT &&
  			allocated <= sk_prot_mem_limits(sk, 0)) {
  		sk_leave_memory_pressure(sk);
  		return 1;
  	}
  
  	/* Under pressure. (we or our parents) */
  	if ((parent_status > SOFT_LIMIT) ||
  			allocated > sk_prot_mem_limits(sk, 1))
  		sk_enter_memory_pressure(sk);
  
  	/* Over hard limit (we or our parents) */
  	if ((parent_status == OVER_LIMIT) ||
  			(allocated > sk_prot_mem_limits(sk, 2)))
  		goto suppress_allocation;
  
  	/* guarantee minimum buffer size under pressure */
  	if (kind == SK_MEM_RECV) {
  		if (atomic_read(&sk->sk_rmem_alloc) < prot->sysctl_rmem[0])
  			return 1;
  
  	} else { /* SK_MEM_SEND */
  		if (sk->sk_type == SOCK_STREAM) {
  			if (sk->sk_wmem_queued < prot->sysctl_wmem[0])
  				return 1;
  		} else if (atomic_read(&sk->sk_wmem_alloc) <
  			   prot->sysctl_wmem[0])
  				return 1;
  	}
  
  	if (sk_has_memory_pressure(sk)) {
  		int alloc;
  
  		if (!sk_under_memory_pressure(sk))
  			return 1;
  		alloc = sk_sockets_allocated_read_positive(sk);
  		if (sk_prot_mem_limits(sk, 2) > alloc *
  		    sk_mem_pages(sk->sk_wmem_queued +
  				 atomic_read(&sk->sk_rmem_alloc) +
  				 sk->sk_forward_alloc))
  			return 1;
  	}
  
  suppress_allocation:
  
  	if (kind == SK_MEM_SEND && sk->sk_type == SOCK_STREAM) {
  		sk_stream_moderate_sndbuf(sk);
  
  		/* Fail only if socket is _under_ its sndbuf.
  		 * In this case we cannot block, so that we have to fail.
  		 */
  		if (sk->sk_wmem_queued + size >= sk->sk_sndbuf)
  			return 1;
  	}
  
  	trace_sock_exceed_buf_limit(sk, prot, allocated);
  
  	/* Alas. Undo changes. */
  	sk->sk_forward_alloc -= amt * SK_MEM_QUANTUM;
  
  	sk_memory_allocated_sub(sk, amt);
  
  	return 0;
  }
  EXPORT_SYMBOL(__sk_mem_schedule);
  
  /**
   *	__sk_reclaim - reclaim memory_allocated
   *	@sk: socket
   */
  void __sk_mem_reclaim(struct sock *sk)
  {
  	sk_memory_allocated_sub(sk,
  				sk->sk_forward_alloc >> SK_MEM_QUANTUM_SHIFT);
  	sk->sk_forward_alloc &= SK_MEM_QUANTUM - 1;
  
  	if (sk_under_memory_pressure(sk) &&
  	    (sk_memory_allocated(sk) < sk_prot_mem_limits(sk, 0)))
  		sk_leave_memory_pressure(sk);
  }
  EXPORT_SYMBOL(__sk_mem_reclaim);
  
  
  /*
   * Set of default routines for initialising struct proto_ops when
   * the protocol does not support a particular function. In certain
   * cases where it makes no sense for a protocol to have a "do nothing"
   * function, some default processing is provided.
   */
  
  int sock_no_bind(struct socket *sock, struct sockaddr *saddr, int len)
  {
  	return -EOPNOTSUPP;
  }
  EXPORT_SYMBOL(sock_no_bind);
  
  int sock_no_connect(struct socket *sock, struct sockaddr *saddr,
  		    int len, int flags)
  {
  	return -EOPNOTSUPP;
  }
  EXPORT_SYMBOL(sock_no_connect);
  
  int sock_no_socketpair(struct socket *sock1, struct socket *sock2)
  {
  	return -EOPNOTSUPP;
  }
  EXPORT_SYMBOL(sock_no_socketpair);
  
  int sock_no_accept(struct socket *sock, struct socket *newsock, int flags)
  {
  	return -EOPNOTSUPP;
  }
  EXPORT_SYMBOL(sock_no_accept);
  
  int sock_no_getname(struct socket *sock, struct sockaddr *saddr,
  		    int *len, int peer)
  {
  	return -EOPNOTSUPP;
  }
  EXPORT_SYMBOL(sock_no_getname);
  
  unsigned int sock_no_poll(struct file *file, struct socket *sock, poll_table *pt)
  {
  	return 0;
  }
  EXPORT_SYMBOL(sock_no_poll);
  
  int sock_no_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
  {
  	return -EOPNOTSUPP;
  }
  EXPORT_SYMBOL(sock_no_ioctl);
  
  int sock_no_listen(struct socket *sock, int backlog)
  {
  	return -EOPNOTSUPP;
  }
  EXPORT_SYMBOL(sock_no_listen);
  
  int sock_no_shutdown(struct socket *sock, int how)
  {
  	return -EOPNOTSUPP;
  }
  EXPORT_SYMBOL(sock_no_shutdown);
  
  int sock_no_setsockopt(struct socket *sock, int level, int optname,
  		    char __user *optval, unsigned int optlen)
  {
  	return -EOPNOTSUPP;
  }
  EXPORT_SYMBOL(sock_no_setsockopt);
  
  int sock_no_getsockopt(struct socket *sock, int level, int optname,
  		    char __user *optval, int __user *optlen)
  {
  	return -EOPNOTSUPP;
  }
  EXPORT_SYMBOL(sock_no_getsockopt);
  
  int sock_no_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
  		    size_t len)
  {
  	return -EOPNOTSUPP;
  }
  EXPORT_SYMBOL(sock_no_sendmsg);
  
  int sock_no_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m,
  		    size_t len, int flags)
  {
  	return -EOPNOTSUPP;
  }
  EXPORT_SYMBOL(sock_no_recvmsg);
  
  int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct *vma)
  {
  	/* Mirror missing mmap method error code */
  	return -ENODEV;
  }
  EXPORT_SYMBOL(sock_no_mmap);
  
  ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags)
  {
  	ssize_t res;
  	struct msghdr msg = {.msg_flags = flags};
  	struct kvec iov;
  	char *kaddr = kmap(page);
  	iov.iov_base = kaddr + offset;
  	iov.iov_len = size;
  	res = kernel_sendmsg(sock, &msg, &iov, 1, size);
  	kunmap(page);
  	return res;
  }
  EXPORT_SYMBOL(sock_no_sendpage);
  
  /*
   *	Default Socket Callbacks
   */
  
  static void sock_def_wakeup(struct sock *sk)
  {
  	struct socket_wq *wq;
  
  	rcu_read_lock();
  	wq = rcu_dereference(sk->sk_wq);
  	if (wq_has_sleeper(wq))
  		wake_up_interruptible_all(&wq->wait);
  	rcu_read_unlock();
  }
  
  static void sock_def_error_report(struct sock *sk)
  {
  	struct socket_wq *wq;
  
  	rcu_read_lock();
  	wq = rcu_dereference(sk->sk_wq);
  	if (wq_has_sleeper(wq))
  		wake_up_interruptible_poll(&wq->wait, POLLERR);
  	sk_wake_async(sk, SOCK_WAKE_IO, POLL_ERR);
  	rcu_read_unlock();
  }
  
  static void sock_def_readable(struct sock *sk, int len)
  {
  	struct socket_wq *wq;
  
  	rcu_read_lock();
  	wq = rcu_dereference(sk->sk_wq);
  	if (wq_has_sleeper(wq))
  		wake_up_interruptible_sync_poll(&wq->wait, POLLIN | POLLPRI |
  						POLLRDNORM | POLLRDBAND);
  	sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN);
  	rcu_read_unlock();
  }
  
  static void sock_def_write_space(struct sock *sk)
  {
  	struct socket_wq *wq;
  
  	rcu_read_lock();
  
  	/* Do not wake up a writer until he can make "significant"
  	 * progress.  --DaveM
  	 */
  	if ((atomic_read(&sk->sk_wmem_alloc) << 1) <= sk->sk_sndbuf) {
  		wq = rcu_dereference(sk->sk_wq);
  		if (wq_has_sleeper(wq))
  			wake_up_interruptible_sync_poll(&wq->wait, POLLOUT |
  						POLLWRNORM | POLLWRBAND);
  
  		/* Should agree with poll, otherwise some programs break */
  		if (sock_writeable(sk))
  			sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT);
  	}
  
  	rcu_read_unlock();
  }
  
  static void sock_def_destruct(struct sock *sk)
  {
  	kfree(sk->sk_protinfo);
  }
  
  void sk_send_sigurg(struct sock *sk)
  {
  	if (sk->sk_socket && sk->sk_socket->file)
  		if (send_sigurg(&sk->sk_socket->file->f_owner))
  			sk_wake_async(sk, SOCK_WAKE_URG, POLL_PRI);
  }
  EXPORT_SYMBOL(sk_send_sigurg);
  
  void sk_reset_timer(struct sock *sk, struct timer_list* timer,
  		    unsigned long expires)
  {
  	if (!mod_timer(timer, expires))
  		sock_hold(sk);
  }
  EXPORT_SYMBOL(sk_reset_timer);
  
  void sk_stop_timer(struct sock *sk, struct timer_list* timer)
  {
  	if (del_timer(timer))
  		__sock_put(sk);
  }
  EXPORT_SYMBOL(sk_stop_timer);
  
  void sock_init_data(struct socket *sock, struct sock *sk)
  {
  	skb_queue_head_init(&sk->sk_receive_queue);
  	skb_queue_head_init(&sk->sk_write_queue);
  	skb_queue_head_init(&sk->sk_error_queue);
  #ifdef CONFIG_NET_DMA
  	skb_queue_head_init(&sk->sk_async_wait_queue);
  #endif
  
  	sk->sk_send_head	=	NULL;
  
  	init_timer(&sk->sk_timer);
  
  	sk->sk_allocation	=	GFP_KERNEL;
  	sk->sk_rcvbuf		=	sysctl_rmem_default;
  	sk->sk_sndbuf		=	sysctl_wmem_default;
  	sk->sk_state		=	TCP_CLOSE;
  	sk_set_socket(sk, sock);
  
  	sock_set_flag(sk, SOCK_ZAPPED);
  
  	if (sock) {
  		sk->sk_type	=	sock->type;
  		sk->sk_wq	=	sock->wq;
  		sock->sk	=	sk;
  	} else
  		sk->sk_wq	=	NULL;
  
  	spin_lock_init(&sk->sk_dst_lock);
  	rwlock_init(&sk->sk_callback_lock);
  	lockdep_set_class_and_name(&sk->sk_callback_lock,
  			af_callback_keys + sk->sk_family,
  			af_family_clock_key_strings[sk->sk_family]);
  
  	sk->sk_state_change	=	sock_def_wakeup;
  	sk->sk_data_ready	=	sock_def_readable;
  	sk->sk_write_space	=	sock_def_write_space;
  	sk->sk_error_report	=	sock_def_error_report;
  	sk->sk_destruct		=	sock_def_destruct;
  
  	sk->sk_frag.page	=	NULL;
  	sk->sk_frag.offset	=	0;
  	sk->sk_peek_off		=	-1;
  
  	sk->sk_peer_pid 	=	NULL;
  	sk->sk_peer_cred	=	NULL;
  	sk->sk_write_pending	=	0;
  	sk->sk_rcvlowat		=	1;
  	sk->sk_rcvtimeo		=	MAX_SCHEDULE_TIMEOUT;
  	sk->sk_sndtimeo		=	MAX_SCHEDULE_TIMEOUT;
  
  	sk->sk_stamp = ktime_set(-1L, 0);
  
  	sk->sk_pacing_rate = ~0U;
  	/*
  	 * Before updating sk_refcnt, we must commit prior changes to memory
  	 * (Documentation/RCU/rculist_nulls.txt for details)
  	 */
  	smp_wmb();
  	atomic_set(&sk->sk_refcnt, 1);
  	atomic_set(&sk->sk_drops, 0);
  }
  EXPORT_SYMBOL(sock_init_data);
  
  void lock_sock_nested(struct sock *sk, int subclass)
  {
  	might_sleep();
  	spin_lock_bh(&sk->sk_lock.slock);
  	if (sk->sk_lock.owned)
  		__lock_sock(sk);
  	sk->sk_lock.owned = 1;
  	spin_unlock(&sk->sk_lock.slock);
  	/*
  	 * The sk_lock has mutex_lock() semantics here:
  	 */
  	mutex_acquire(&sk->sk_lock.dep_map, subclass, 0, _RET_IP_);
  	local_bh_enable();
  }
  EXPORT_SYMBOL(lock_sock_nested);
  
  void release_sock(struct sock *sk)
  {
  	/*
  	 * The sk_lock has mutex_unlock() semantics:
  	 */
  	mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
  
  	spin_lock_bh(&sk->sk_lock.slock);
  	if (sk->sk_backlog.tail)
  		__release_sock(sk);
  
  	/* Warning : release_cb() might need to release sk ownership,
  	 * ie call sock_release_ownership(sk) before us.
  	 */
  	if (sk->sk_prot->release_cb)
  		sk->sk_prot->release_cb(sk);
  
  	sock_release_ownership(sk);
  	if (waitqueue_active(&sk->sk_lock.wq))
  		wake_up(&sk->sk_lock.wq);
  	spin_unlock_bh(&sk->sk_lock.slock);
  }
  EXPORT_SYMBOL(release_sock);
  
  /**
   * lock_sock_fast - fast version of lock_sock
   * @sk: socket
   *
   * This version should be used for very small section, where process wont block
   * return false if fast path is taken
   *   sk_lock.slock locked, owned = 0, BH disabled
   * return true if slow path is taken
   *   sk_lock.slock unlocked, owned = 1, BH enabled
   */
  bool lock_sock_fast(struct sock *sk)
  {
  	might_sleep();
  	spin_lock_bh(&sk->sk_lock.slock);
  
  	if (!sk->sk_lock.owned)
  		/*
  		 * Note : We must disable BH
  		 */
  		return false;
  
  	__lock_sock(sk);
  	sk->sk_lock.owned = 1;
  	spin_unlock(&sk->sk_lock.slock);
  	/*
  	 * The sk_lock has mutex_lock() semantics here:
  	 */
  	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
  	local_bh_enable();
  	return true;
  }
  EXPORT_SYMBOL(lock_sock_fast);
  
  int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
  {
  	struct timeval tv;
  	if (!sock_flag(sk, SOCK_TIMESTAMP))
  		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
  	tv = ktime_to_timeval(sk->sk_stamp);
  	if (tv.tv_sec == -1)
  		return -ENOENT;
  	if (tv.tv_sec == 0) {
  		sk->sk_stamp = ktime_get_real();
  		tv = ktime_to_timeval(sk->sk_stamp);
  	}
  	return copy_to_user(userstamp, &tv, sizeof(tv)) ? -EFAULT : 0;
  }
  EXPORT_SYMBOL(sock_get_timestamp);
  
  int sock_get_timestampns(struct sock *sk, struct timespec __user *userstamp)
  {
  	struct timespec ts;
  	if (!sock_flag(sk, SOCK_TIMESTAMP))
  		sock_enable_timestamp(sk, SOCK_TIMESTAMP);
  	ts = ktime_to_timespec(sk->sk_stamp);
  	if (ts.tv_sec == -1)
  		return -ENOENT;
  	if (ts.tv_sec == 0) {
  		sk->sk_stamp = ktime_get_real();
  		ts = ktime_to_timespec(sk->sk_stamp);
  	}
  	return copy_to_user(userstamp, &ts, sizeof(ts)) ? -EFAULT : 0;
  }
  EXPORT_SYMBOL(sock_get_timestampns);
  
  void sock_enable_timestamp(struct sock *sk, int flag)
  {
  	if (!sock_flag(sk, flag)) {
  		unsigned long previous_flags = sk->sk_flags;
  
  		sock_set_flag(sk, flag);
  		/*
  		 * we just set one of the two flags which require net
  		 * time stamping, but time stamping might have been on
  		 * already because of the other one
  		 */
  		if (!(previous_flags & SK_FLAGS_TIMESTAMP))
  			net_enable_timestamp();
  	}
  }
  
  /*
   *	Get a socket option on an socket.
   *
   *	FIX: POSIX 1003.1g is very ambiguous here. It states that
   *	asynchronous errors should be reported by getsockopt. We assume
   *	this means if you specify SO_ERROR (otherwise whats the point of it).
   */
  int sock_common_getsockopt(struct socket *sock, int level, int optname,
  			   char __user *optval, int __user *optlen)
  {
  	struct sock *sk = sock->sk;
  
  	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
  }
  EXPORT_SYMBOL(sock_common_getsockopt);
  
  #ifdef CONFIG_COMPAT
  int compat_sock_common_getsockopt(struct socket *sock, int level, int optname,
  				  char __user *optval, int __user *optlen)
  {
  	struct sock *sk = sock->sk;
  
  	if (sk->sk_prot->compat_getsockopt != NULL)
  		return sk->sk_prot->compat_getsockopt(sk, level, optname,
  						      optval, optlen);
  	return sk->sk_prot->getsockopt(sk, level, optname, optval, optlen);
  }
  EXPORT_SYMBOL(compat_sock_common_getsockopt);
  #endif
  
  int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock,
  			struct msghdr *msg, size_t size, int flags)
  {
  	struct sock *sk = sock->sk;
  	int addr_len = 0;
  	int err;
  
  	err = sk->sk_prot->recvmsg(iocb, sk, msg, size, flags & MSG_DONTWAIT,
  				   flags & ~MSG_DONTWAIT, &addr_len);
  	if (err >= 0)
  		msg->msg_namelen = addr_len;
  	return err;
  }
  EXPORT_SYMBOL(sock_common_recvmsg);
  
  /*
   *	Set socket options on an inet socket.
   */
  int sock_common_setsockopt(struct socket *sock, int level, int optname,
  			   char __user *optval, unsigned int optlen)
  {
  	struct sock *sk = sock->sk;
  
  	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
  }
  EXPORT_SYMBOL(sock_common_setsockopt);
  
  #ifdef CONFIG_COMPAT
  int compat_sock_common_setsockopt(struct socket *sock, int level, int optname,
  				  char __user *optval, unsigned int optlen)
  {
  	struct sock *sk = sock->sk;
  
  	if (sk->sk_prot->compat_setsockopt != NULL)
  		return sk->sk_prot->compat_setsockopt(sk, level, optname,
  						      optval, optlen);
  	return sk->sk_prot->setsockopt(sk, level, optname, optval, optlen);
  }
  EXPORT_SYMBOL(compat_sock_common_setsockopt);
  #endif
  
  void sk_common_release(struct sock *sk)
  {
  	if (sk->sk_prot->destroy)
  		sk->sk_prot->destroy(sk);
  
  	/*
  	 * Observation: when sock_common_release is called, processes have
  	 * no access to socket. But net still has.
  	 * Step one, detach it from networking:
  	 *
  	 * A. Remove from hash tables.
  	 */
  
  	sk->sk_prot->unhash(sk);
  
  	/*
  	 * In this point socket cannot receive new packets, but it is possible
  	 * that some packets are in flight because some CPU runs receiver and
  	 * did hash table lookup before we unhashed socket. They will achieve
  	 * receive queue and will be purged by socket destructor.
  	 *
  	 * Also we still have packets pending on receive queue and probably,
  	 * our own packets waiting in device queues. sock_destroy will drain
  	 * receive queue, but transmitted packets will delay socket destruction
  	 * until the last reference will be released.
  	 */
  
  	sock_orphan(sk);
  
  	xfrm_sk_free_policy(sk);
  
  	sk_refcnt_debug_release(sk);
  
  	if (sk->sk_frag.page) {
  		put_page(sk->sk_frag.page);
  		sk->sk_frag.page = NULL;
  	}
  
  	sock_put(sk);
  }
  EXPORT_SYMBOL(sk_common_release);
  
  #ifdef CONFIG_PROC_FS
  #define PROTO_INUSE_NR	64	/* should be enough for the first time */
  struct prot_inuse {
  	int val[PROTO_INUSE_NR];
  };
  
  static DECLARE_BITMAP(proto_inuse_idx, PROTO_INUSE_NR);
  
  #ifdef CONFIG_NET_NS
  void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
  {
  	__this_cpu_add(net->core.inuse->val[prot->inuse_idx], val);
  }
  EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
  
  int sock_prot_inuse_get(struct net *net, struct proto *prot)
  {
  	int cpu, idx = prot->inuse_idx;
  	int res = 0;
  
  	for_each_possible_cpu(cpu)
  		res += per_cpu_ptr(net->core.inuse, cpu)->val[idx];
  
  	return res >= 0 ? res : 0;
  }
  EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
  
  static int __net_init sock_inuse_init_net(struct net *net)
  {
  	net->core.inuse = alloc_percpu(struct prot_inuse);
  	return net->core.inuse ? 0 : -ENOMEM;
  }
  
  static void __net_exit sock_inuse_exit_net(struct net *net)
  {
  	free_percpu(net->core.inuse);
  }
  
  static struct pernet_operations net_inuse_ops = {
  	.init = sock_inuse_init_net,
  	.exit = sock_inuse_exit_net,
  };
  
  static __init int net_inuse_init(void)
  {
  	if (register_pernet_subsys(&net_inuse_ops))
  		panic("Cannot initialize net inuse counters");
  
  	return 0;
  }
  
  core_initcall(net_inuse_init);
  #else
  static DEFINE_PER_CPU(struct prot_inuse, prot_inuse);
  
  void sock_prot_inuse_add(struct net *net, struct proto *prot, int val)
  {
  	__this_cpu_add(prot_inuse.val[prot->inuse_idx], val);
  }
  EXPORT_SYMBOL_GPL(sock_prot_inuse_add);
  
  int sock_prot_inuse_get(struct net *net, struct proto *prot)
  {
  	int cpu, idx = prot->inuse_idx;
  	int res = 0;
  
  	for_each_possible_cpu(cpu)
  		res += per_cpu(prot_inuse, cpu).val[idx];
  
  	return res >= 0 ? res : 0;
  }
  EXPORT_SYMBOL_GPL(sock_prot_inuse_get);
  #endif
  
  static void assign_proto_idx(struct proto *prot)
  {
  	prot->inuse_idx = find_first_zero_bit(proto_inuse_idx, PROTO_INUSE_NR);
  
  	if (unlikely(prot->inuse_idx == PROTO_INUSE_NR - 1)) {
  		pr_err("PROTO_INUSE_NR exhausted\n");
  		return;
  	}
  
  	set_bit(prot->inuse_idx, proto_inuse_idx);
  }
  
  static void release_proto_idx(struct proto *prot)
  {
  	if (prot->inuse_idx != PROTO_INUSE_NR - 1)
  		clear_bit(prot->inuse_idx, proto_inuse_idx);
  }
  #else
  static inline void assign_proto_idx(struct proto *prot)
  {
  }
  
  static inline void release_proto_idx(struct proto *prot)
  {
  }
  #endif
  
  int proto_register(struct proto *prot, int alloc_slab)
  {
  	if (alloc_slab) {
  		prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0,
  					SLAB_HWCACHE_ALIGN | prot->slab_flags,
  					NULL);
  
  		if (prot->slab == NULL) {
  			pr_crit("%s: Can't create sock SLAB cache!\n",
  				prot->name);
  			goto out;
  		}
  
  		if (prot->rsk_prot != NULL) {
  			prot->rsk_prot->slab_name = kasprintf(GFP_KERNEL, "request_sock_%s", prot->name);
  			if (prot->rsk_prot->slab_name == NULL)
  				goto out_free_sock_slab;
  
  			prot->rsk_prot->slab = kmem_cache_create(prot->rsk_prot->slab_name,
  								 prot->rsk_prot->obj_size, 0,
  								 SLAB_HWCACHE_ALIGN, NULL);
  
  			if (prot->rsk_prot->slab == NULL) {
  				pr_crit("%s: Can't create request sock SLAB cache!\n",
  					prot->name);
  				goto out_free_request_sock_slab_name;
  			}
  		}
  
  		if (prot->twsk_prot != NULL) {
  			prot->twsk_prot->twsk_slab_name = kasprintf(GFP_KERNEL, "tw_sock_%s", prot->name);
  
  			if (prot->twsk_prot->twsk_slab_name == NULL)
  				goto out_free_request_sock_slab;
  
  			prot->twsk_prot->twsk_slab =
  				kmem_cache_create(prot->twsk_prot->twsk_slab_name,
  						  prot->twsk_prot->twsk_obj_size,
  						  0,
  						  SLAB_HWCACHE_ALIGN |
  							prot->slab_flags,
  						  NULL);
  			if (prot->twsk_prot->twsk_slab == NULL)
  				goto out_free_timewait_sock_slab_name;
  		}
  	}
  
  	mutex_lock(&proto_list_mutex);
  	list_add(&prot->node, &proto_list);
  	assign_proto_idx(prot);
  	mutex_unlock(&proto_list_mutex);
  	return 0;
  
  out_free_timewait_sock_slab_name:
  	kfree(prot->twsk_prot->twsk_slab_name);
  out_free_request_sock_slab:
  	if (prot->rsk_prot && prot->rsk_prot->slab) {
  		kmem_cache_destroy(prot->rsk_prot->slab);
  		prot->rsk_prot->slab = NULL;
  	}
  out_free_request_sock_slab_name:
  	if (prot->rsk_prot)
  		kfree(prot->rsk_prot->slab_name);
  out_free_sock_slab:
  	kmem_cache_destroy(prot->slab);
  	prot->slab = NULL;
  out:
  	return -ENOBUFS;
  }
  EXPORT_SYMBOL(proto_register);
  
  void proto_unregister(struct proto *prot)
  {
  	mutex_lock(&proto_list_mutex);
  	release_proto_idx(prot);
  	list_del(&prot->node);
  	mutex_unlock(&proto_list_mutex);
  
  	if (prot->slab != NULL) {
  		kmem_cache_destroy(prot->slab);
  		prot->slab = NULL;
  	}
  
  	if (prot->rsk_prot != NULL && prot->rsk_prot->slab != NULL) {
  		kmem_cache_destroy(prot->rsk_prot->slab);
  		kfree(prot->rsk_prot->slab_name);
  		prot->rsk_prot->slab = NULL;
  	}
  
  	if (prot->twsk_prot != NULL && prot->twsk_prot->twsk_slab != NULL) {
  		kmem_cache_destroy(prot->twsk_prot->twsk_slab);
  		kfree(prot->twsk_prot->twsk_slab_name);
  		prot->twsk_prot->twsk_slab = NULL;
  	}
  }
  EXPORT_SYMBOL(proto_unregister);
  
  #ifdef CONFIG_PROC_FS
  static void *proto_seq_start(struct seq_file *seq, loff_t *pos)
  	__acquires(proto_list_mutex)
  {
  	mutex_lock(&proto_list_mutex);
  	return seq_list_start_head(&proto_list, *pos);
  }
  
  static void *proto_seq_next(struct seq_file *seq, void *v, loff_t *pos)
  {
  	return seq_list_next(v, &proto_list, pos);
  }
  
  static void proto_seq_stop(struct seq_file *seq, void *v)
  	__releases(proto_list_mutex)
  {
  	mutex_unlock(&proto_list_mutex);
  }
  
  static char proto_method_implemented(const void *method)
  {
  	return method == NULL ? 'n' : 'y';
  }
  static long sock_prot_memory_allocated(struct proto *proto)
  {
  	return proto->memory_allocated != NULL ? proto_memory_allocated(proto) : -1L;
  }
  
  static char *sock_prot_memory_pressure(struct proto *proto)
  {
  	return proto->memory_pressure != NULL ?
  	proto_memory_pressure(proto) ? "yes" : "no" : "NI";
  }
  
  static void proto_seq_printf(struct seq_file *seq, struct proto *proto)
  {
  
  	seq_printf(seq, "%-9s %4u %6d  %6ld   %-3s %6u   %-3s  %-10s "
  			"%2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c %2c\n",
  		   proto->name,
  		   proto->obj_size,
  		   sock_prot_inuse_get(seq_file_net(seq), proto),
  		   sock_prot_memory_allocated(proto),
  		   sock_prot_memory_pressure(proto),
  		   proto->max_header,
  		   proto->slab == NULL ? "no" : "yes",
  		   module_name(proto->owner),
  		   proto_method_implemented(proto->close),
  		   proto_method_implemented(proto->connect),
  		   proto_method_implemented(proto->disconnect),
  		   proto_method_implemented(proto->accept),
  		   proto_method_implemented(proto->ioctl),
  		   proto_method_implemented(proto->init),
  		   proto_method_implemented(proto->destroy),
  		   proto_method_implemented(proto->shutdown),
  		   proto_method_implemented(proto->setsockopt),
  		   proto_method_implemented(proto->getsockopt),
  		   proto_method_implemented(proto->sendmsg),
  		   proto_method_implemented(proto->recvmsg),
  		   proto_method_implemented(proto->sendpage),
  		   proto_method_implemented(proto->bind),
  		   proto_method_implemented(proto->backlog_rcv),
  		   proto_method_implemented(proto->hash),
  		   proto_method_implemented(proto->unhash),
  		   proto_method_implemented(proto->get_port),
  		   proto_method_implemented(proto->enter_memory_pressure));
  }
  
  static int proto_seq_show(struct seq_file *seq, void *v)
  {
  	if (v == &proto_list)
  		seq_printf(seq, "%-9s %-4s %-8s %-6s %-5s %-7s %-4s %-10s %s",
  			   "protocol",
  			   "size",
  			   "sockets",
  			   "memory",
  			   "press",
  			   "maxhdr",
  			   "slab",
  			   "module",
  			   "cl co di ac io in de sh ss gs se re sp bi br ha uh gp em\n");
  	else
  		proto_seq_printf(seq, list_entry(v, struct proto, node));
  	return 0;
  }
  
  static const struct seq_operations proto_seq_ops = {
  	.start  = proto_seq_start,
  	.next   = proto_seq_next,
  	.stop   = proto_seq_stop,
  	.show   = proto_seq_show,
  };
  
  static int proto_seq_open(struct inode *inode, struct file *file)
  {
  	return seq_open_net(inode, file, &proto_seq_ops,
  			    sizeof(struct seq_net_private));
  }
  
  static const struct file_operations proto_seq_fops = {
  	.owner		= THIS_MODULE,
  	.open		= proto_seq_open,
  	.read		= seq_read,
  	.llseek		= seq_lseek,
  	.release	= seq_release_net,
  };
  
  static __net_init int proto_init_net(struct net *net)
  {
  	if (!proc_create("protocols", S_IRUGO, net->proc_net, &proto_seq_fops))
  		return -ENOMEM;
  
  	return 0;
  }
  
  static __net_exit void proto_exit_net(struct net *net)
  {
  	remove_proc_entry("protocols", net->proc_net);
  }
  
  
  static __net_initdata struct pernet_operations proto_net_ops = {
  	.init = proto_init_net,
  	.exit = proto_exit_net,
  };
  
  static int __init proto_init(void)
  {
  	return register_pernet_subsys(&proto_net_ops);
  }
  
  subsys_initcall(proto_init);
  
  #endif /* PROC_FS */
  