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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 /* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  * 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.
  *
  *      Definitions for the AF_INET socket handler.
  *
  * Version: @(#)sock.h  1.0.4   05/13/93
  *
  * Authors: Ross Biro
  *      Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  *      Corey Minyard <wf-rch!minyard@relay.EU.net>
  *      Florian La Roche <flla@stud.uni-sb.de>
  *
  * Fixes:
  *      Alan Cox    :   Volatiles in skbuff pointers. See
  *                  skbuff comments. May be overdone,
  *                  better to prove they can be removed
  *                  than the reverse.
  *      Alan Cox    :   Added a zapped field for tcp to note
  *                  a socket is reset and must stay shut up
  *      Alan Cox    :   New fields for options
  *  Pauline Middelink   :   identd support
  *      Alan Cox    :   Eliminate low level recv/recvfrom
  *      David S. Miller :   New socket lookup architecture.
  *              Steve Whitehouse:       Default routines for sock_ops
  *              Arnaldo C. Melo :   removed net_pinfo, tp_pinfo and made
  *                          protinfo be just a void pointer, as the
  *                          protocol specific parts were moved to
  *                          respective headers and ipv4/v6, etc now
  *                          use private slabcaches for its socks
  *              Pedro Hortas    :   New flags field for socket options
  */
 #ifndef _SOCK_H
 #define _SOCK_H
 
 #include <linux/hardirq.h>
 #include <linux/kernel.h>
 #include <linux/list.h>
 #include <linux/list_nulls.h>
 #include <linux/timer.h>
 #include <linux/cache.h>
 #include <linux/bitops.h>
 #include <linux/lockdep.h>
 #include <linux/netdevice.h>
 #include <linux/skbuff.h>   /* struct sk_buff */
 #include <linux/mm.h>
 #include <linux/security.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 #include <linux/page_counter.h>
 #include <linux/memcontrol.h>
 #include <linux/static_key.h>
 #include <linux/sched.h>
 #include <linux/wait.h>
 #include <linux/cgroup-defs.h>
 #include <linux/rbtree.h>
 #include <linux/rculist_nulls.h>
 #include <linux/poll.h>
 #include <linux/sockptr.h>
 #include <linux/indirect_call_wrapper.h>
 #include <linux/atomic.h>
 #include <linux/refcount.h>
 #include <linux/llist.h>
 #include <net/dst.h>
 #include <net/checksum.h>
 #include <net/tcp_states.h>
 #include <linux/net_tstamp.h>
 #include <net/l3mdev.h>
 #include <uapi/linux/socket.h>
 
 /*
  * This structure really needs to be cleaned up.
  * Most of it is for TCP, and not used by any of
  * the other protocols.
  */
 
 /* Define this to get the SOCK_DBG debugging facility. */
 #define SOCK_DEBUGGING
 #ifdef SOCK_DEBUGGING
 #define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
                     printk(KERN_DEBUG msg); } while (0)
 #else
 /* Validate arguments and do nothing */
 static inline __printf(2, 3)
 void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
 {
 }
 #endif
 
 /* This is the per-socket lock.  The spinlock provides a synchronization
  * between user contexts and software interrupt processing, whereas the
  * mini-semaphore synchronizes multiple users amongst themselves.
  */
 typedef struct {
     spinlock_t      slock;
     int         owned;
     wait_queue_head_t   wq;
     /*
      * We express the mutex-alike socket_lock semantics
      * to the lock validator by explicitly managing
      * the slock as a lock variant (in addition to
      * the slock itself):
      */
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
     struct lockdep_map dep_map;
 #endif
 } socket_lock_t;
 
 struct sock;
 struct proto;
 struct net;
 
 typedef __u32 __bitwise __portpair;
 typedef __u64 __bitwise __addrpair;
 
 /**
  *  struct sock_common - minimal network layer representation of sockets
  *  @skc_daddr: Foreign IPv4 addr
  *  @skc_rcv_saddr: Bound local IPv4 addr
  *  @skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr
  *  @skc_hash: hash value used with various protocol lookup tables
  *  @skc_u16hashes: two u16 hash values used by UDP lookup tables
  *  @skc_dport: placeholder for inet_dport/tw_dport
  *  @skc_num: placeholder for inet_num/tw_num
  *  @skc_portpair: __u32 union of @skc_dport & @skc_num
  *  @skc_family: network address family
  *  @skc_state: Connection state
  *  @skc_reuse: %SO_REUSEADDR setting
  *  @skc_reuseport: %SO_REUSEPORT setting
  *  @skc_ipv6only: socket is IPV6 only
  *  @skc_net_refcnt: socket is using net ref counting
  *  @skc_bound_dev_if: bound device index if != 0
  *  @skc_bind_node: bind hash linkage for various protocol lookup tables
  *  @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
  *  @skc_prot: protocol handlers inside a network family
  *  @skc_net: reference to the network namespace of this socket
  *  @skc_v6_daddr: IPV6 destination address
  *  @skc_v6_rcv_saddr: IPV6 source address
  *  @skc_cookie: socket's cookie value
  *  @skc_node: main hash linkage for various protocol lookup tables
  *  @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
  *  @skc_tx_queue_mapping: tx queue number for this connection
  *  @skc_rx_queue_mapping: rx queue number for this connection
  *  @skc_flags: place holder for sk_flags
  *      %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
  *      %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
  *  @skc_listener: connection request listener socket (aka rsk_listener)
  *      [union with @skc_flags]
  *  @skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row
  *      [union with @skc_flags]
  *  @skc_incoming_cpu: record/match cpu processing incoming packets
  *  @skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled)
  *      [union with @skc_incoming_cpu]
  *  @skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number
  *      [union with @skc_incoming_cpu]
  *  @skc_refcnt: reference count
  *
  *  This is the minimal network layer representation of sockets, the header
  *  for struct sock and struct inet_timewait_sock.
  */
 struct sock_common {
     union {
         __addrpair  skc_addrpair;
         struct {
             __be32  skc_daddr;
             __be32  skc_rcv_saddr;
         };
     };
     union  {
         unsigned int    skc_hash;
         __u16       skc_u16hashes[2];
     };
     /* skc_dport && skc_num must be grouped as well */
     union {
         __portpair  skc_portpair;
         struct {
             __be16  skc_dport;
             __u16   skc_num;
         };
     };
 
     unsigned short      skc_family;
     volatile unsigned char  skc_state;
     unsigned char       skc_reuse:4;
     unsigned char       skc_reuseport:1;
     unsigned char       skc_ipv6only:1;
     unsigned char       skc_net_refcnt:1;
     int         skc_bound_dev_if;
     union {
         struct hlist_node   skc_bind_node;
         struct hlist_node   skc_portaddr_node;
     };
     struct proto        *skc_prot;
     possible_net_t      skc_net;
 
 #if IS_ENABLED(CONFIG_IPV6)
     struct in6_addr     skc_v6_daddr;
     struct in6_addr     skc_v6_rcv_saddr;
 #endif
 
     atomic64_t      skc_cookie;
 
     /* following fields are padding to force
      * offset(struct sock, sk_refcnt) == 128 on 64bit arches
      * assuming IPV6 is enabled. We use this padding differently
      * for different kind of 'sockets'
      */
     union {
         unsigned long   skc_flags;
         struct sock *skc_listener; /* request_sock */
         struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
     };
     /*
      * fields between dontcopy_begin/dontcopy_end
      * are not copied in sock_copy()
      */
     /* private: */
     int         skc_dontcopy_begin[0];
     /* public: */
     union {
         struct hlist_node   skc_node;
         struct hlist_nulls_node skc_nulls_node;
     };
     unsigned short      skc_tx_queue_mapping;
 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
     unsigned short      skc_rx_queue_mapping;
 #endif
     union {
         int     skc_incoming_cpu;
         u32     skc_rcv_wnd;
         u32     skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
     };
 
     refcount_t      skc_refcnt;
     /* private: */
     int                     skc_dontcopy_end[0];
     union {
         u32     skc_rxhash;
         u32     skc_window_clamp;
         u32     skc_tw_snd_nxt; /* struct tcp_timewait_sock */
     };
     /* public: */
 };
 
 struct bpf_local_storage;
 struct sk_filter;
 
 /**
   * struct sock - network layer representation of sockets
   * @__sk_common: shared layout with inet_timewait_sock
   * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
   * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
   * @sk_lock:   synchronizer
   * @sk_kern_sock: True if sock is using kernel lock classes
   * @sk_rcvbuf: size of receive buffer in bytes
   * @sk_wq: sock wait queue and async head
   * @sk_rx_dst: receive input route used by early demux
   * @sk_rx_dst_ifindex: ifindex for @sk_rx_dst
   * @sk_rx_dst_cookie: cookie for @sk_rx_dst
   * @sk_dst_cache: destination cache
   * @sk_dst_pending_confirm: need to confirm neighbour
   * @sk_policy: flow policy
   * @sk_receive_queue: incoming packets
   * @sk_wmem_alloc: transmit queue bytes committed
   * @sk_tsq_flags: TCP Small Queues flags
   * @sk_write_queue: Packet sending queue
   * @sk_omem_alloc: "o" is "option" or "other"
   * @sk_wmem_queued: persistent queue size
   * @sk_forward_alloc: space allocated forward
   * @sk_reserved_mem: space reserved and non-reclaimable for the socket
   * @sk_napi_id: id of the last napi context to receive data for sk
   * @sk_ll_usec: usecs to busypoll when there is no data
   * @sk_allocation: allocation mode
   * @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
   * @sk_pacing_status: Pacing status (requested, handled by sch_fq)
   * @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
   * @sk_sndbuf: size of send buffer in bytes
   * @__sk_flags_offset: empty field used to determine location of bitfield
   * @sk_padding: unused element for alignment
   * @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
   * @sk_no_check_rx: allow zero checksum in RX packets
   * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
   * @sk_gso_disabled: if set, NETIF_F_GSO_MASK is forbidden.
   * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
   * @sk_gso_max_size: Maximum GSO segment size to build
   * @sk_gso_max_segs: Maximum number of GSO segments
   * @sk_pacing_shift: scaling factor for TCP Small Queues
   * @sk_lingertime: %SO_LINGER l_linger setting
   * @sk_backlog: always used with the per-socket spinlock held
   * @sk_callback_lock: used with the callbacks in the end of this struct
   * @sk_error_queue: rarely used
   * @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
   *           IPV6_ADDRFORM for instance)
   * @sk_err: last error
   * @sk_err_soft: errors that don't cause failure but are the cause of a
   *           persistent failure not just 'timed out'
   * @sk_drops: raw/udp drops counter
   * @sk_ack_backlog: current listen backlog
   * @sk_max_ack_backlog: listen backlog set in listen()
   * @sk_uid: user id of owner
   * @sk_prefer_busy_poll: prefer busypolling over softirq processing
   * @sk_busy_poll_budget: napi processing budget when busypolling
   * @sk_priority: %SO_PRIORITY setting
   * @sk_type: socket type (%SOCK_STREAM, etc)
   * @sk_protocol: which protocol this socket belongs in this network family
   * @sk_peer_lock: lock protecting @sk_peer_pid and @sk_peer_cred
   * @sk_peer_pid: &struct pid for this socket's peer
   * @sk_peer_cred: %SO_PEERCRED setting
   * @sk_rcvlowat: %SO_RCVLOWAT setting
   * @sk_rcvtimeo: %SO_RCVTIMEO setting
   * @sk_sndtimeo: %SO_SNDTIMEO setting
   * @sk_txhash: computed flow hash for use on transmit
   * @sk_txrehash: enable TX hash rethink
   * @sk_filter: socket filtering instructions
   * @sk_timer: sock cleanup timer
   * @sk_stamp: time stamp of last packet received
   * @sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
   * @sk_tsflags: SO_TIMESTAMPING flags
   * @sk_bind_phc: SO_TIMESTAMPING bind PHC index of PTP virtual clock
   *               for timestamping
   * @sk_tskey: counter to disambiguate concurrent tstamp requests
   * @sk_zckey: counter to order MSG_ZEROCOPY notifications
   * @sk_socket: Identd and reporting IO signals
   * @sk_user_data: RPC layer private data
   * @sk_frag: cached page frag
   * @sk_peek_off: current peek_offset value
   * @sk_send_head: front of stuff to transmit
   * @tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head]
   * @sk_security: used by security modules
   * @sk_mark: generic packet mark
   * @sk_cgrp_data: cgroup data for this cgroup
   * @sk_memcg: this socket's memory cgroup association
   * @sk_write_pending: a write to stream socket waits to start
   * @sk_state_change: callback to indicate change in the state of the sock
   * @sk_data_ready: callback to indicate there is data to be processed
   * @sk_write_space: callback to indicate there is bf sending space available
   * @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
   * @sk_backlog_rcv: callback to process the backlog
   * @sk_validate_xmit_skb: ptr to an optional validate function
   * @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
   * @sk_reuseport_cb: reuseport group container
   * @sk_bpf_storage: ptr to cache and control for bpf_sk_storage
   * @sk_rcu: used during RCU grace period
   * @sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
   * @sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
   * @sk_txtime_report_errors: set report errors mode for SO_TXTIME
   * @sk_txtime_unused: unused txtime flags
   * @ns_tracker: tracker for netns reference
   */
 struct sock {
     /*
      * Now struct inet_timewait_sock also uses sock_common, so please just
      * don't add nothing before this first member (__sk_common) --acme
      */
     struct sock_common  __sk_common;
 #define sk_node         __sk_common.skc_node
 #define sk_nulls_node       __sk_common.skc_nulls_node
 #define sk_refcnt       __sk_common.skc_refcnt
 #define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping
 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
 #define sk_rx_queue_mapping __sk_common.skc_rx_queue_mapping
 #endif
 
 #define sk_dontcopy_begin   __sk_common.skc_dontcopy_begin
 #define sk_dontcopy_end     __sk_common.skc_dontcopy_end
 #define sk_hash         __sk_common.skc_hash
 #define sk_portpair     __sk_common.skc_portpair
 #define sk_num          __sk_common.skc_num
 #define sk_dport        __sk_common.skc_dport
 #define sk_addrpair     __sk_common.skc_addrpair
 #define sk_daddr        __sk_common.skc_daddr
 #define sk_rcv_saddr        __sk_common.skc_rcv_saddr
 #define sk_family       __sk_common.skc_family
 #define sk_state        __sk_common.skc_state
 #define sk_reuse        __sk_common.skc_reuse
 #define sk_reuseport        __sk_common.skc_reuseport
 #define sk_ipv6only     __sk_common.skc_ipv6only
 #define sk_net_refcnt       __sk_common.skc_net_refcnt
 #define sk_bound_dev_if     __sk_common.skc_bound_dev_if
 #define sk_bind_node        __sk_common.skc_bind_node
 #define sk_prot         __sk_common.skc_prot
 #define sk_net          __sk_common.skc_net
 #define sk_v6_daddr     __sk_common.skc_v6_daddr
 #define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
 #define sk_cookie       __sk_common.skc_cookie
 #define sk_incoming_cpu     __sk_common.skc_incoming_cpu
 #define sk_flags        __sk_common.skc_flags
 #define sk_rxhash       __sk_common.skc_rxhash
 
     /* early demux fields */
     struct dst_entry __rcu  *sk_rx_dst;
     int         sk_rx_dst_ifindex;
     u32         sk_rx_dst_cookie;
 
     socket_lock_t       sk_lock;
     atomic_t        sk_drops;
     int         sk_rcvlowat;
     struct sk_buff_head sk_error_queue;
     struct sk_buff_head sk_receive_queue;
     /*
      * The backlog queue is special, it is always used with
      * the per-socket spinlock held and requires low latency
      * access. Therefore we special case it's implementation.
      * Note : rmem_alloc is in this structure to fill a hole
      * on 64bit arches, not because its logically part of
      * backlog.
      */
     struct {
         atomic_t    rmem_alloc;
         int     len;
         struct sk_buff  *head;
         struct sk_buff  *tail;
     } sk_backlog;
 
 #define sk_rmem_alloc sk_backlog.rmem_alloc
 
     int         sk_forward_alloc;
     u32         sk_reserved_mem;
 #ifdef CONFIG_NET_RX_BUSY_POLL
     unsigned int        sk_ll_usec;
     /* ===== mostly read cache line ===== */
     unsigned int        sk_napi_id;
 #endif
     int         sk_rcvbuf;
 
     struct sk_filter __rcu  *sk_filter;
     union {
         struct socket_wq __rcu  *sk_wq;
         /* private: */
         struct socket_wq    *sk_wq_raw;
         /* public: */
     };
 #ifdef CONFIG_XFRM
     struct xfrm_policy __rcu *sk_policy[2];
 #endif
 
     struct dst_entry __rcu  *sk_dst_cache;
     atomic_t        sk_omem_alloc;
     int         sk_sndbuf;
 
     /* ===== cache line for TX ===== */
     int         sk_wmem_queued;
     refcount_t      sk_wmem_alloc;
     unsigned long       sk_tsq_flags;
     union {
         struct sk_buff  *sk_send_head;
         struct rb_root  tcp_rtx_queue;
     };
     struct sk_buff_head sk_write_queue;
     __s32           sk_peek_off;
     int         sk_write_pending;
     __u32           sk_dst_pending_confirm;
     u32         sk_pacing_status; /* see enum sk_pacing */
     long            sk_sndtimeo;
     struct timer_list   sk_timer;
     __u32           sk_priority;
     __u32           sk_mark;
     unsigned long       sk_pacing_rate; /* bytes per second */
     unsigned long       sk_max_pacing_rate;
     struct page_frag    sk_frag;
     netdev_features_t   sk_route_caps;
     int         sk_gso_type;
     unsigned int        sk_gso_max_size;
     gfp_t           sk_allocation;
     __u32           sk_txhash;
 
     /*
      * Because of non atomicity rules, all
      * changes are protected by socket lock.
      */
     u8          sk_gso_disabled : 1,
                 sk_kern_sock : 1,
                 sk_no_check_tx : 1,
                 sk_no_check_rx : 1,
                 sk_userlocks : 4;
     u8          sk_pacing_shift;
     u16         sk_type;
     u16         sk_protocol;
     u16         sk_gso_max_segs;
     unsigned long           sk_lingertime;
     struct proto        *sk_prot_creator;
     rwlock_t        sk_callback_lock;
     int         sk_err,
                 sk_err_soft;
     u32         sk_ack_backlog;
     u32         sk_max_ack_backlog;
     kuid_t          sk_uid;
     u8          sk_txrehash;
 #ifdef CONFIG_NET_RX_BUSY_POLL
     u8          sk_prefer_busy_poll;
     u16         sk_busy_poll_budget;
 #endif
     spinlock_t      sk_peer_lock;
     int         sk_bind_phc;
     struct pid      *sk_peer_pid;
     const struct cred   *sk_peer_cred;
 
     long            sk_rcvtimeo;
     ktime_t         sk_stamp;
 #if BITS_PER_LONG==32
     seqlock_t       sk_stamp_seq;
 #endif
     u16         sk_tsflags;
     u8          sk_shutdown;
     atomic_t        sk_tskey;
     atomic_t        sk_zckey;
 
     u8          sk_clockid;
     u8          sk_txtime_deadline_mode : 1,
                 sk_txtime_report_errors : 1,
                 sk_txtime_unused : 6;
 
     struct socket       *sk_socket;
     void            *sk_user_data;
 #ifdef CONFIG_SECURITY
     void            *sk_security;
 #endif
     struct sock_cgroup_data sk_cgrp_data;
     struct mem_cgroup   *sk_memcg;
     void            (*sk_state_change)(struct sock *sk);
     void            (*sk_data_ready)(struct sock *sk);
     void            (*sk_write_space)(struct sock *sk);
     void            (*sk_error_report)(struct sock *sk);
     int         (*sk_backlog_rcv)(struct sock *sk,
                           struct sk_buff *skb);
 #ifdef CONFIG_SOCK_VALIDATE_XMIT
     struct sk_buff*     (*sk_validate_xmit_skb)(struct sock *sk,
                             struct net_device *dev,
                             struct sk_buff *skb);
 #endif
     void                    (*sk_destruct)(struct sock *sk);
     struct sock_reuseport __rcu *sk_reuseport_cb;
 #ifdef CONFIG_BPF_SYSCALL
     struct bpf_local_storage __rcu  *sk_bpf_storage;
 #endif
     struct rcu_head     sk_rcu;
     netns_tracker       ns_tracker;
 };
 
 enum sk_pacing {
     SK_PACING_NONE      = 0,
     SK_PACING_NEEDED    = 1,
     SK_PACING_FQ        = 2,
 };
 
 /* flag bits in sk_user_data
  *
  * - SK_USER_DATA_NOCOPY:      Pointer stored in sk_user_data might
  *   not be suitable for copying when cloning the socket. For instance,
  *   it can point to a reference counted object. sk_user_data bottom
  *   bit is set if pointer must not be copied.
  *
  * - SK_USER_DATA_BPF:         Mark whether sk_user_data field is
  *   managed/owned by a BPF reuseport array. This bit should be set
  *   when sk_user_data's sk is added to the bpf's reuseport_array.
  *
  * - SK_USER_DATA_PSOCK:       Mark whether pointer stored in
  *   sk_user_data points to psock type. This bit should be set
  *   when sk_user_data is assigned to a psock object.
  */
 #define SK_USER_DATA_NOCOPY 1UL
 #define SK_USER_DATA_BPF    2UL
 #define SK_USER_DATA_PSOCK  4UL
 #define SK_USER_DATA_PTRMASK    ~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF |\
                   SK_USER_DATA_PSOCK)
 
 /**
  * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
  * @sk: socket
  */
 static inline bool sk_user_data_is_nocopy(const struct sock *sk)
 {
     return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
 }
 
 #define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
 
 /**
  * __locked_read_sk_user_data_with_flags - return the pointer
  * only if argument flags all has been set in sk_user_data. Otherwise
  * return NULL
  *
  * @sk: socket
  * @flags: flag bits
  *
  * The caller must be holding sk->sk_callback_lock.
  */
 static inline void *
 __locked_read_sk_user_data_with_flags(const struct sock *sk,
                       uintptr_t flags)
 {
     uintptr_t sk_user_data =
         (uintptr_t)rcu_dereference_check(__sk_user_data(sk),
                          lockdep_is_held(&sk->sk_callback_lock));
 
     WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
 
     if ((sk_user_data & flags) == flags)
         return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
     return NULL;
 }
 
 /**
  * __rcu_dereference_sk_user_data_with_flags - return the pointer
  * only if argument flags all has been set in sk_user_data. Otherwise
  * return NULL
  *
  * @sk: socket
  * @flags: flag bits
  */
 static inline void *
 __rcu_dereference_sk_user_data_with_flags(const struct sock *sk,
                       uintptr_t flags)
 {
     uintptr_t sk_user_data = (uintptr_t)rcu_dereference(__sk_user_data(sk));
 
     WARN_ON_ONCE(flags & SK_USER_DATA_PTRMASK);
 
     if ((sk_user_data & flags) == flags)
         return (void *)(sk_user_data & SK_USER_DATA_PTRMASK);
     return NULL;
 }
 
 #define rcu_dereference_sk_user_data(sk)                \
     __rcu_dereference_sk_user_data_with_flags(sk, 0)
 #define __rcu_assign_sk_user_data_with_flags(sk, ptr, flags)        \
 ({                                  \
     uintptr_t __tmp1 = (uintptr_t)(ptr),                \
           __tmp2 = (uintptr_t)(flags);              \
     WARN_ON_ONCE(__tmp1 & ~SK_USER_DATA_PTRMASK);           \
     WARN_ON_ONCE(__tmp2 & SK_USER_DATA_PTRMASK);            \
     rcu_assign_pointer(__sk_user_data((sk)),            \
                __tmp1 | __tmp2);                \
 })
 #define rcu_assign_sk_user_data(sk, ptr)                \
     __rcu_assign_sk_user_data_with_flags(sk, ptr, 0)
 
 static inline
 struct net *sock_net(const struct sock *sk)
 {
     return read_pnet(&sk->sk_net);
 }
 
 static inline
 void sock_net_set(struct sock *sk, struct net *net)
 {
     write_pnet(&sk->sk_net, net);
 }
 
 /*
  * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
  * or not whether his port will be reused by someone else. SK_FORCE_REUSE
  * on a socket means that the socket will reuse everybody else's port
  * without looking at the other's sk_reuse value.
  */
 
 #define SK_NO_REUSE 0
 #define SK_CAN_REUSE    1
 #define SK_FORCE_REUSE  2
 
 int sk_set_peek_off(struct sock *sk, int val);
 
 static inline int sk_peek_offset(const struct sock *sk, int flags)
 {
     if (unlikely(flags & MSG_PEEK)) {
         return READ_ONCE(sk->sk_peek_off);
     }
 
     return 0;
 }
 
 static inline void sk_peek_offset_bwd(struct sock *sk, int val)
 {
     s32 off = READ_ONCE(sk->sk_peek_off);
 
     if (unlikely(off >= 0)) {
         off = max_t(s32, off - val, 0);
         WRITE_ONCE(sk->sk_peek_off, off);
     }
 }
 
 static inline void sk_peek_offset_fwd(struct sock *sk, int val)
 {
     sk_peek_offset_bwd(sk, -val);
 }
 
 /*
  * Hashed lists helper routines
  */
 static inline struct sock *sk_entry(const struct hlist_node *node)
 {
     return hlist_entry(node, struct sock, sk_node);
 }
 
 static inline struct sock *__sk_head(const struct hlist_head *head)
 {
     return hlist_entry(head->first, struct sock, sk_node);
 }
 
 static inline struct sock *sk_head(const struct hlist_head *head)
 {
     return hlist_empty(head) ? NULL : __sk_head(head);
 }
 
 static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
 {
     return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
 }
 
 static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
 {
     return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
 }
 
 static inline struct sock *sk_next(const struct sock *sk)
 {
     return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
 }
 
 static inline struct sock *sk_nulls_next(const struct sock *sk)
 {
     return (!is_a_nulls(sk->sk_nulls_node.next)) ?
         hlist_nulls_entry(sk->sk_nulls_node.next,
                   struct sock, sk_nulls_node) :
         NULL;
 }
 
 static inline bool sk_unhashed(const struct sock *sk)
 {
     return hlist_unhashed(&sk->sk_node);
 }
 
 static inline bool sk_hashed(const struct sock *sk)
 {
     return !sk_unhashed(sk);
 }
 
 static inline void sk_node_init(struct hlist_node *node)
 {
     node->pprev = NULL;
 }
 
 static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
 {
     node->pprev = NULL;
 }
 
 static inline void __sk_del_node(struct sock *sk)
 {
     __hlist_del(&sk->sk_node);
 }
 
 /* NB: equivalent to hlist_del_init_rcu */
 static inline bool __sk_del_node_init(struct sock *sk)
 {
     if (sk_hashed(sk)) {
         __sk_del_node(sk);
         sk_node_init(&sk->sk_node);
         return true;
     }
     return false;
 }
 
 /* Grab socket reference count. This operation is valid only
    when sk is ALREADY grabbed f.e. it is found in hash table
    or a list and the lookup is made under lock preventing hash table
    modifications.
  */
 
 static __always_inline void sock_hold(struct sock *sk)
 {
     refcount_inc(&sk->sk_refcnt);
 }
 
 /* Ungrab socket in the context, which assumes that socket refcnt
    cannot hit zero, f.e. it is true in context of any socketcall.
  */
 static __always_inline void __sock_put(struct sock *sk)
 {
     refcount_dec(&sk->sk_refcnt);
 }
 
 static inline bool sk_del_node_init(struct sock *sk)
 {
     bool rc = __sk_del_node_init(sk);
 
     if (rc) {
         /* paranoid for a while -acme */
         WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
         __sock_put(sk);
     }
     return rc;
 }
 #define sk_del_node_init_rcu(sk)    sk_del_node_init(sk)
 
 static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
 {
     if (sk_hashed(sk)) {
         hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
         return true;
     }
     return false;
 }
 
 static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
 {
     bool rc = __sk_nulls_del_node_init_rcu(sk);
 
     if (rc) {
         /* paranoid for a while -acme */
         WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
         __sock_put(sk);
     }
     return rc;
 }
 
 static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
 {
     hlist_add_head(&sk->sk_node, list);
 }
 
 static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
 {
     sock_hold(sk);
     __sk_add_node(sk, list);
 }
 
 static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
 {
     sock_hold(sk);
     if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
         sk->sk_family == AF_INET6)
         hlist_add_tail_rcu(&sk->sk_node, list);
     else
         hlist_add_head_rcu(&sk->sk_node, list);
 }
 
 static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
 {
     sock_hold(sk);
     hlist_add_tail_rcu(&sk->sk_node, list);
 }
 
 static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
 {
     hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
 }
 
 static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
 {
     hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
 }
 
 static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
 {
     sock_hold(sk);
     __sk_nulls_add_node_rcu(sk, list);
 }
 
 static inline void __sk_del_bind_node(struct sock *sk)
 {
     __hlist_del(&sk->sk_bind_node);
 }
 
 static inline void sk_add_bind_node(struct sock *sk,
                     struct hlist_head *list)
 {
     hlist_add_head(&sk->sk_bind_node, list);
 }
 
 #define sk_for_each(__sk, list) \
     hlist_for_each_entry(__sk, list, sk_node)
 #define sk_for_each_rcu(__sk, list) \
     hlist_for_each_entry_rcu(__sk, list, sk_node)
 #define sk_nulls_for_each(__sk, node, list) \
     hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
 #define sk_nulls_for_each_rcu(__sk, node, list) \
     hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
 #define sk_for_each_from(__sk) \
     hlist_for_each_entry_from(__sk, sk_node)
 #define sk_nulls_for_each_from(__sk, node) \
     if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
         hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
 #define sk_for_each_safe(__sk, tmp, list) \
     hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
 #define sk_for_each_bound(__sk, list) \
     hlist_for_each_entry(__sk, list, sk_bind_node)
 
 /**
  * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
  * @tpos:   the type * to use as a loop cursor.
  * @pos:    the &struct hlist_node to use as a loop cursor.
  * @head:   the head for your list.
  * @offset: offset of hlist_node within the struct.
  *
  */
 #define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)              \
     for (pos = rcu_dereference(hlist_first_rcu(head));             \
          pos != NULL &&                            \
         ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
          pos = rcu_dereference(hlist_next_rcu(pos)))
 
 static inline struct user_namespace *sk_user_ns(const struct sock *sk)
 {
     /* Careful only use this in a context where these parameters
      * can not change and must all be valid, such as recvmsg from
      * userspace.
      */
     return sk->sk_socket->file->f_cred->user_ns;
 }
 
 /* Sock flags */
 enum sock_flags {
     SOCK_DEAD,
     SOCK_DONE,
     SOCK_URGINLINE,
     SOCK_KEEPOPEN,
     SOCK_LINGER,
     SOCK_DESTROY,
     SOCK_BROADCAST,
     SOCK_TIMESTAMP,
     SOCK_ZAPPED,
     SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
     SOCK_DBG, /* %SO_DEBUG setting */
     SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
     SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
     SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
     SOCK_MEMALLOC, /* VM depends on this socket for swapping */
     SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
     SOCK_FASYNC, /* fasync() active */
     SOCK_RXQ_OVFL,
     SOCK_ZEROCOPY, /* buffers from userspace */
     SOCK_WIFI_STATUS, /* push wifi status to userspace */
     SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
              * Will use last 4 bytes of packet sent from
              * user-space instead.
              */
     SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
     SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
     SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
     SOCK_TXTIME,
     SOCK_XDP, /* XDP is attached */
     SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
     SOCK_RCVMARK, /* Receive SO_MARK  ancillary data with packet */
 };
 
 #define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
 
 static inline void sock_copy_flags(struct sock *nsk, const struct sock *osk)
 {
     nsk->sk_flags = osk->sk_flags;
 }
 
 static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
 {
     __set_bit(flag, &sk->sk_flags);
 }
 
 static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
 {
     __clear_bit(flag, &sk->sk_flags);
 }
 
 static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
                      int valbool)
 {
     if (valbool)
         sock_set_flag(sk, bit);
     else
         sock_reset_flag(sk, bit);
 }
 
 static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
 {
     return test_bit(flag, &sk->sk_flags);
 }
 
 #ifdef CONFIG_NET
 DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
 static inline int sk_memalloc_socks(void)
 {
     return static_branch_unlikely(&memalloc_socks_key);
 }
 
 void __receive_sock(struct file *file);
 #else
 
 static inline int sk_memalloc_socks(void)
 {
     return 0;
 }
 
 static inline void __receive_sock(struct file *file)
 { }
 #endif
 
 static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
 {
     return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
 }
 
 static inline void sk_acceptq_removed(struct sock *sk)
 {
     WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
 }
 
 static inline void sk_acceptq_added(struct sock *sk)
 {
     WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
 }
 
 /* Note: If you think the test should be:
  *  return READ_ONCE(sk->sk_ack_backlog) >= READ_ONCE(sk->sk_max_ack_backlog);
  * Then please take a look at commit 64a146513f8f ("[NET]: Revert incorrect accept queue backlog changes.")
  */
 static inline bool sk_acceptq_is_full(const struct sock *sk)
 {
     return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
 }
 
 /*
  * Compute minimal free write space needed to queue new packets.
  */
 static inline int sk_stream_min_wspace(const struct sock *sk)
 {
     return READ_ONCE(sk->sk_wmem_queued) >> 1;
 }
 
 static inline int sk_stream_wspace(const struct sock *sk)
 {
     return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
 }
 
 static inline void sk_wmem_queued_add(struct sock *sk, int val)
 {
     WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
 }
 
 void sk_stream_write_space(struct sock *sk);
 
 /* OOB backlog add */
 static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
 {
     /* dont let skb dst not refcounted, we are going to leave rcu lock */
     skb_dst_force(skb);
 
     if (!sk->sk_backlog.tail)
         WRITE_ONCE(sk->sk_backlog.head, skb);
     else
         sk->sk_backlog.tail->next = skb;
 
     WRITE_ONCE(sk->sk_backlog.tail, skb);
     skb->next = NULL;
 }
 
 /*
  * Take into account size of receive queue and backlog queue
  * Do not take into account this skb truesize,
  * to allow even a single big packet to come.
  */
 static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
 {
     unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
 
     return qsize > limit;
 }
 
 /* The per-socket spinlock must be held here. */
 static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
                           unsigned int limit)
 {
     if (sk_rcvqueues_full(sk, limit))
         return -ENOBUFS;
 
     /*
      * If the skb was allocated from pfmemalloc reserves, only
      * allow SOCK_MEMALLOC sockets to use it as this socket is
      * helping free memory
      */
     if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
         return -ENOMEM;
 
     __sk_add_backlog(sk, skb);
     sk->sk_backlog.len += skb->truesize;
     return 0;
 }
 
 int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 
 INDIRECT_CALLABLE_DECLARE(int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb));
 INDIRECT_CALLABLE_DECLARE(int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb));
 
 static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
 {
     if (sk_memalloc_socks() && skb_pfmemalloc(skb))
         return __sk_backlog_rcv(sk, skb);
 
     return INDIRECT_CALL_INET(sk->sk_backlog_rcv,
                   tcp_v6_do_rcv,
                   tcp_v4_do_rcv,
                   sk, skb);
 }
 
 static inline void sk_incoming_cpu_update(struct sock *sk)
 {
     int cpu = raw_smp_processor_id();
 
     if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
         WRITE_ONCE(sk->sk_incoming_cpu, cpu);
 }
 
 static inline void sock_rps_record_flow_hash(__u32 hash)
 {
 #ifdef CONFIG_RPS
     struct rps_sock_flow_table *sock_flow_table;
 
     rcu_read_lock();
     sock_flow_table = rcu_dereference(rps_sock_flow_table);
     rps_record_sock_flow(sock_flow_table, hash);
     rcu_read_unlock();
 #endif
 }
 
 static inline void sock_rps_record_flow(const struct sock *sk)
 {
 #ifdef CONFIG_RPS
     if (static_branch_unlikely(&rfs_needed)) {
         /* Reading sk->sk_rxhash might incur an expensive cache line
          * miss.
          *
          * TCP_ESTABLISHED does cover almost all states where RFS
          * might be useful, and is cheaper [1] than testing :
          *  IPv4: inet_sk(sk)->inet_daddr
          *  IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
          * OR   an additional socket flag
          * [1] : sk_state and sk_prot are in the same cache line.
          */
         if (sk->sk_state == TCP_ESTABLISHED)
             sock_rps_record_flow_hash(sk->sk_rxhash);
     }
 #endif
 }
 
 static inline void sock_rps_save_rxhash(struct sock *sk,
                     const struct sk_buff *skb)
 {
 #ifdef CONFIG_RPS
     if (unlikely(sk->sk_rxhash != skb->hash))
         sk->sk_rxhash = skb->hash;
 #endif
 }
 
 static inline void sock_rps_reset_rxhash(struct sock *sk)
 {
 #ifdef CONFIG_RPS
     sk->sk_rxhash = 0;
 #endif
 }
 
 #define sk_wait_event(__sk, __timeo, __condition, __wait)       \
     ({  int __rc;                       \
         release_sock(__sk);                 \
         __rc = __condition;                 \
         if (!__rc) {                        \
             *(__timeo) = wait_woken(__wait,         \
                         TASK_INTERRUPTIBLE, \
                         *(__timeo));        \
         }                           \
         sched_annotate_sleep();                 \
         lock_sock(__sk);                    \
         __rc = __condition;                 \
         __rc;                           \
     })
 
 int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
 int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
 void sk_stream_wait_close(struct sock *sk, long timeo_p);
 int sk_stream_error(struct sock *sk, int flags, int err);
 void sk_stream_kill_queues(struct sock *sk);
 void sk_set_memalloc(struct sock *sk);
 void sk_clear_memalloc(struct sock *sk);
 
 void __sk_flush_backlog(struct sock *sk);
 
 static inline bool sk_flush_backlog(struct sock *sk)
 {
     if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
         __sk_flush_backlog(sk);
         return true;
     }
     return false;
 }
 
 int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
 
 struct request_sock_ops;
 struct timewait_sock_ops;
 struct inet_hashinfo;
 struct raw_hashinfo;
 struct smc_hashinfo;
 struct module;
 struct sk_psock;
 
 /*
  * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
  * un-modified. Special care is taken when initializing object to zero.
  */
 static inline void sk_prot_clear_nulls(struct sock *sk, int size)
 {
     if (offsetof(struct sock, sk_node.next) != 0)
         memset(sk, 0, offsetof(struct sock, sk_node.next));
     memset(&sk->sk_node.pprev, 0,
            size - offsetof(struct sock, sk_node.pprev));
 }
 
 /* Networking protocol blocks we attach to sockets.
  * socket layer -> transport layer interface
  */
 struct proto {
     void            (*close)(struct sock *sk,
                     long timeout);
     int         (*pre_connect)(struct sock *sk,
                     struct sockaddr *uaddr,
                     int addr_len);
     int         (*connect)(struct sock *sk,
                     struct sockaddr *uaddr,
                     int addr_len);
     int         (*disconnect)(struct sock *sk, int flags);
 
     struct sock *       (*accept)(struct sock *sk, int flags, int *err,
                       bool kern);
 
     int         (*ioctl)(struct sock *sk, int cmd,
                      unsigned long arg);
     int         (*init)(struct sock *sk);
     void            (*destroy)(struct sock *sk);
     void            (*shutdown)(struct sock *sk, int how);
     int         (*setsockopt)(struct sock *sk, int level,
                     int optname, sockptr_t optval,
                     unsigned int optlen);
     int         (*getsockopt)(struct sock *sk, int level,
                     int optname, char __user *optval,
                     int __user *option);
     void            (*keepalive)(struct sock *sk, int valbool);
 #ifdef CONFIG_COMPAT
     int         (*compat_ioctl)(struct sock *sk,
                     unsigned int cmd, unsigned long arg);
 #endif
     int         (*sendmsg)(struct sock *sk, struct msghdr *msg,
                        size_t len);
     int         (*recvmsg)(struct sock *sk, struct msghdr *msg,
                        size_t len, int flags, int *addr_len);
     int         (*sendpage)(struct sock *sk, struct page *page,
                     int offset, size_t size, int flags);
     int         (*bind)(struct sock *sk,
                     struct sockaddr *addr, int addr_len);
     int         (*bind_add)(struct sock *sk,
                     struct sockaddr *addr, int addr_len);
 
     int         (*backlog_rcv) (struct sock *sk,
                         struct sk_buff *skb);
     bool            (*bpf_bypass_getsockopt)(int level,
                              int optname);
 
     void        (*release_cb)(struct sock *sk);
 
     /* Keeping track of sk's, looking them up, and port selection methods. */
     int         (*hash)(struct sock *sk);
     void            (*unhash)(struct sock *sk);
     void            (*rehash)(struct sock *sk);
     int         (*get_port)(struct sock *sk, unsigned short snum);
     void            (*put_port)(struct sock *sk);
 #ifdef CONFIG_BPF_SYSCALL
     int         (*psock_update_sk_prot)(struct sock *sk,
                             struct sk_psock *psock,
                             bool restore);
 #endif
 
     /* Keeping track of sockets in use */
 #ifdef CONFIG_PROC_FS
     unsigned int        inuse_idx;
 #endif
 
 #if IS_ENABLED(CONFIG_MPTCP)
     int         (*forward_alloc_get)(const struct sock *sk);
 #endif
 
     bool            (*stream_memory_free)(const struct sock *sk, int wake);
     bool            (*sock_is_readable)(struct sock *sk);
     /* Memory pressure */
     void            (*enter_memory_pressure)(struct sock *sk);
     void            (*leave_memory_pressure)(struct sock *sk);
     atomic_long_t       *memory_allocated;  /* Current allocated memory. */
     int  __percpu       *per_cpu_fw_alloc;
     struct percpu_counter   *sockets_allocated; /* Current number of sockets. */
 
     /*
      * Pressure flag: try to collapse.
      * Technical note: it is used by multiple contexts non atomically.
      * All the __sk_mem_schedule() is of this nature: accounting
      * is strict, actions are advisory and have some latency.
      */
     unsigned long       *memory_pressure;
     long            *sysctl_mem;
 
     int         *sysctl_wmem;
     int         *sysctl_rmem;
     u32         sysctl_wmem_offset;
     u32         sysctl_rmem_offset;
 
     int         max_header;
     bool            no_autobind;
 
     struct kmem_cache   *slab;
     unsigned int        obj_size;
     slab_flags_t        slab_flags;
     unsigned int        useroffset; /* Usercopy region offset */
     unsigned int        usersize;   /* Usercopy region size */
 
     unsigned int __percpu   *orphan_count;
 
     struct request_sock_ops *rsk_prot;
     struct timewait_sock_ops *twsk_prot;
 
     union {
         struct inet_hashinfo    *hashinfo;
         struct udp_table    *udp_table;
         struct raw_hashinfo *raw_hash;
         struct smc_hashinfo *smc_hash;
     } h;
 
     struct module       *owner;
 
     char            name[32];
 
     struct list_head    node;
 #ifdef SOCK_REFCNT_DEBUG
     atomic_t        socks;
 #endif
     int         (*diag_destroy)(struct sock *sk, int err);
 } __randomize_layout;
 
 int proto_register(struct proto *prot, int alloc_slab);
 void proto_unregister(struct proto *prot);
 int sock_load_diag_module(int family, int protocol);
 
 #ifdef SOCK_REFCNT_DEBUG
 static inline void sk_refcnt_debug_inc(struct sock *sk)
 {
     atomic_inc(&sk->sk_prot->socks);
 }
 
 static inline void sk_refcnt_debug_dec(struct sock *sk)
 {
     atomic_dec(&sk->sk_prot->socks);
     printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
            sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
 }
 
 static inline void sk_refcnt_debug_release(const struct sock *sk)
 {
     if (refcount_read(&sk->sk_refcnt) != 1)
         printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
                sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
 }
 #else /* SOCK_REFCNT_DEBUG */
 #define sk_refcnt_debug_inc(sk) do { } while (0)
 #define sk_refcnt_debug_dec(sk) do { } while (0)
 #define sk_refcnt_debug_release(sk) do { } while (0)
 #endif /* SOCK_REFCNT_DEBUG */
 
 INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
 
 static inline int sk_forward_alloc_get(const struct sock *sk)
 {
 #if IS_ENABLED(CONFIG_MPTCP)
     if (sk->sk_prot->forward_alloc_get)
         return sk->sk_prot->forward_alloc_get(sk);
 #endif
     return sk->sk_forward_alloc;
 }
 
 static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
 {
     if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
         return false;
 
     return sk->sk_prot->stream_memory_free ?
         INDIRECT_CALL_INET_1(sk->sk_prot->stream_memory_free,
                      tcp_stream_memory_free, sk, wake) : true;
 }
 
 static inline bool sk_stream_memory_free(const struct sock *sk)
 {
     return __sk_stream_memory_free(sk, 0);
 }
 
 static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
 {
     return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
            __sk_stream_memory_free(sk, wake);
 }
 
 static inline bool sk_stream_is_writeable(const struct sock *sk)
 {
     return __sk_stream_is_writeable(sk, 0);
 }
 
 static inline int sk_under_cgroup_hierarchy(struct sock *sk,
                         struct cgroup *ancestor)
 {
 #ifdef CONFIG_SOCK_CGROUP_DATA
     return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
                     ancestor);
 #else
     return -ENOTSUPP;
 #endif
 }
 
 static inline bool sk_has_memory_pressure(const struct sock *sk)
 {
     return sk->sk_prot->memory_pressure != NULL;
 }
 
 static inline bool sk_under_memory_pressure(const struct sock *sk)
 {
     if (!sk->sk_prot->memory_pressure)
         return false;
 
     if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
         mem_cgroup_under_socket_pressure(sk->sk_memcg))
         return true;
 
     return !!*sk->sk_prot->memory_pressure;
 }
 
 static inline long
 proto_memory_allocated(const struct proto *prot)
 {
     return max(0L, atomic_long_read(prot->memory_allocated));
 }
 
 static inline long
 sk_memory_allocated(const struct sock *sk)
 {
     return proto_memory_allocated(sk->sk_prot);
 }
 
 /* 1 MB per cpu, in page units */
 #define SK_MEMORY_PCPU_RESERVE (1 << (20 - PAGE_SHIFT))
 
 static inline void
 sk_memory_allocated_add(struct sock *sk, int amt)
 {
     int local_reserve;
 
     preempt_disable();
     local_reserve = __this_cpu_add_return(*sk->sk_prot->per_cpu_fw_alloc, amt);
     if (local_reserve >= SK_MEMORY_PCPU_RESERVE) {
         __this_cpu_sub(*sk->sk_prot->per_cpu_fw_alloc, local_reserve);
         atomic_long_add(local_reserve, sk->sk_prot->memory_allocated);
     }
     preempt_enable();
 }
 
 static inline void
 sk_memory_allocated_sub(struct sock *sk, int amt)
 {
     int local_reserve;
 
     preempt_disable();
     local_reserve = __this_cpu_sub_return(*sk->sk_prot->per_cpu_fw_alloc, amt);
     if (local_reserve <= -SK_MEMORY_PCPU_RESERVE) {
         __this_cpu_sub(*sk->sk_prot->per_cpu_fw_alloc, local_reserve);
         atomic_long_add(local_reserve, sk->sk_prot->memory_allocated);
     }
     preempt_enable();
 }
 
 #define SK_ALLOC_PERCPU_COUNTER_BATCH 16
 
 static inline void sk_sockets_allocated_dec(struct sock *sk)
 {
     percpu_counter_add_batch(sk->sk_prot->sockets_allocated, -1,
                  SK_ALLOC_PERCPU_COUNTER_BATCH);
 }
 
 static inline void sk_sockets_allocated_inc(struct sock *sk)
 {
     percpu_counter_add_batch(sk->sk_prot->sockets_allocated, 1,
                  SK_ALLOC_PERCPU_COUNTER_BATCH);
 }
 
 static inline u64
 sk_sockets_allocated_read_positive(struct sock *sk)
 {
     return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
 }
 
 static inline int
 proto_sockets_allocated_sum_positive(struct proto *prot)
 {
     return percpu_counter_sum_positive(prot->sockets_allocated);
 }
 
 static inline bool
 proto_memory_pressure(struct proto *prot)
 {
     if (!prot->memory_pressure)
         return false;
     return !!*prot->memory_pressure;
 }
 
 
 #ifdef CONFIG_PROC_FS
 #define PROTO_INUSE_NR  64  /* should be enough for the first time */
 struct prot_inuse {
     int all;
     int val[PROTO_INUSE_NR];
 };
 
 static inline void sock_prot_inuse_add(const struct net *net,
                        const struct proto *prot, int val)
 {
     this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
 }
 
 static inline void sock_inuse_add(const struct net *net, int val)
 {
     this_cpu_add(net->core.prot_inuse->all, val);
 }
 
 int sock_prot_inuse_get(struct net *net, struct proto *proto);
 int sock_inuse_get(struct net *net);
 #else
 static inline void sock_prot_inuse_add(const struct net *net,
                        const struct proto *prot, int val)
 {
 }
 
 static inline void sock_inuse_add(const struct net *net, int val)
 {
 }
 #endif
 
 
 /* With per-bucket locks this operation is not-atomic, so that
  * this version is not worse.
  */
 static inline int __sk_prot_rehash(struct sock *sk)
 {
     sk->sk_prot->unhash(sk);
     return sk->sk_prot->hash(sk);
 }
 
 /* About 10 seconds */
 #define SOCK_DESTROY_TIME (10*HZ)
 
 /* Sockets 0-1023 can't be bound to unless you are superuser */
 #define PROT_SOCK   1024
 
 #define SHUTDOWN_MASK   3
 #define RCV_SHUTDOWN    1
 #define SEND_SHUTDOWN   2
 
 #define SOCK_BINDADDR_LOCK  4
 #define SOCK_BINDPORT_LOCK  8
 
 struct socket_alloc {
     struct socket socket;
     struct inode vfs_inode;
 };
 
 static inline struct socket *SOCKET_I(struct inode *inode)
 {
     return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
 }
 
 static inline struct inode *SOCK_INODE(struct socket *socket)
 {
     return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
 }
 
 /*
  * Functions for memory accounting
  */
 int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
 int __sk_mem_schedule(struct sock *sk, int size, int kind);
 void __sk_mem_reduce_allocated(struct sock *sk, int amount);
 void __sk_mem_reclaim(struct sock *sk, int amount);
 
 #define SK_MEM_SEND 0
 #define SK_MEM_RECV 1
 
 /* sysctl_mem values are in pages */
 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
 {
     return READ_ONCE(sk->sk_prot->sysctl_mem[index]);
 }
 
 static inline int sk_mem_pages(int amt)
 {
     return (amt + PAGE_SIZE - 1) >> PAGE_SHIFT;
 }
 
 static inline bool sk_has_account(struct sock *sk)
 {
     /* return true if protocol supports memory accounting */
     return !!sk->sk_prot->memory_allocated;
 }
 
 static inline bool sk_wmem_schedule(struct sock *sk, int size)
 {
     int delta;
 
     if (!sk_has_account(sk))
         return true;
     delta = size - sk->sk_forward_alloc;
     return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_SEND);
 }
 
 static inline bool
 sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
 {
     int delta;
 
     if (!sk_has_account(sk))
         return true;
     delta = size - sk->sk_forward_alloc;
     return delta <= 0 || __sk_mem_schedule(sk, delta, SK_MEM_RECV) ||
         skb_pfmemalloc(skb);
 }
 
 static inline int sk_unused_reserved_mem(const struct sock *sk)
 {
     int unused_mem;
 
     if (likely(!sk->sk_reserved_mem))
         return 0;
 
     unused_mem = sk->sk_reserved_mem - sk->sk_wmem_queued -
             atomic_read(&sk->sk_rmem_alloc);
 
     return unused_mem > 0 ? unused_mem : 0;
 }
 
 static inline void sk_mem_reclaim(struct sock *sk)
 {
     int reclaimable;
 
     if (!sk_has_account(sk))
         return;
 
     reclaimable = sk->sk_forward_alloc - sk_unused_reserved_mem(sk);
 
     if (reclaimable >= (int)PAGE_SIZE)
         __sk_mem_reclaim(sk, reclaimable);
 }
 
 static inline void sk_mem_reclaim_final(struct sock *sk)
 {
     sk->sk_reserved_mem = 0;
     sk_mem_reclaim(sk);
 }
 
 static inline void sk_mem_charge(struct sock *sk, int size)
 {
     if (!sk_has_account(sk))
         return;
     sk->sk_forward_alloc -= size;
 }
 
 static inline void sk_mem_uncharge(struct sock *sk, int size)
 {
     if (!sk_has_account(sk))
         return;
     sk->sk_forward_alloc += size;
     sk_mem_reclaim(sk);
 }
 
 /*
  * Macro so as to not evaluate some arguments when
  * lockdep is not enabled.
  *
  * Mark both the sk_lock and the sk_lock.slock as a
  * per-address-family lock class.
  */
 #define sock_lock_init_class_and_name(sk, sname, skey, name, key)   \
 do {                                    \
     sk->sk_lock.owned = 0;                      \
     init_waitqueue_head(&sk->sk_lock.wq);               \
     spin_lock_init(&(sk)->sk_lock.slock);               \
     debug_check_no_locks_freed((void *)&(sk)->sk_lock,      \
             sizeof((sk)->sk_lock));             \
     lockdep_set_class_and_name(&(sk)->sk_lock.slock,        \
                 (skey), (sname));               \
     lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \
 } while (0)
 
 static inline bool lockdep_sock_is_held(const struct sock *sk)
 {
     return lockdep_is_held(&sk->sk_lock) ||
            lockdep_is_held(&sk->sk_lock.slock);
 }
 
 void lock_sock_nested(struct sock *sk, int subclass);
 
 static inline void lock_sock(struct sock *sk)
 {
     lock_sock_nested(sk, 0);
 }
 
 void __lock_sock(struct sock *sk);
 void __release_sock(struct sock *sk);
 void release_sock(struct sock *sk);
 
 /* BH context may only use the following locking interface. */
 #define bh_lock_sock(__sk)  spin_lock(&((__sk)->sk_lock.slock))
 #define bh_lock_sock_nested(__sk) \
                 spin_lock_nested(&((__sk)->sk_lock.slock), \
                 SINGLE_DEPTH_NESTING)
 #define bh_unlock_sock(__sk)    spin_unlock(&((__sk)->sk_lock.slock))
 
 bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock);
 
 /**
  * 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
  */
 static inline bool lock_sock_fast(struct sock *sk)
 {
     /* The sk_lock has mutex_lock() semantics here. */
     mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
 
     return __lock_sock_fast(sk);
 }
 
 /* fast socket lock variant for caller already holding a [different] socket lock */
 static inline bool lock_sock_fast_nested(struct sock *sk)
 {
     mutex_acquire(&sk->sk_lock.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_);
 
     return __lock_sock_fast(sk);
 }
 
 /**
  * unlock_sock_fast - complement of lock_sock_fast
  * @sk: socket
  * @slow: slow mode
  *
  * fast unlock socket for user context.
  * If slow mode is on, we call regular release_sock()
  */
 static inline void unlock_sock_fast(struct sock *sk, bool slow)
     __releases(&sk->sk_lock.slock)
 {
     if (slow) {
         release_sock(sk);
         __release(&sk->sk_lock.slock);
     } else {
         mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
         spin_unlock_bh(&sk->sk_lock.slock);
     }
 }
 
 /* Used by processes to "lock" a socket state, so that
  * interrupts and bottom half handlers won't change it
  * from under us. It essentially blocks any incoming
  * packets, so that we won't get any new data or any
  * packets that change the state of the socket.
  *
  * While locked, BH processing will add new packets to
  * the backlog queue.  This queue is processed by the
  * owner of the socket lock right before it is released.
  *
  * Since ~2.3.5 it is also exclusive sleep lock serializing
  * accesses from user process context.
  */
 
 static inline void sock_owned_by_me(const struct sock *sk)
 {
 #ifdef CONFIG_LOCKDEP
     WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
 #endif
 }
 
 static inline bool sock_owned_by_user(const struct sock *sk)
 {
     sock_owned_by_me(sk);
     return sk->sk_lock.owned;
 }
 
 static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
 {
     return sk->sk_lock.owned;
 }
 
 static inline void sock_release_ownership(struct sock *sk)
 {
     if (sock_owned_by_user_nocheck(sk)) {
         sk->sk_lock.owned = 0;
 
         /* The sk_lock has mutex_unlock() semantics: */
         mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
     }
 }
 
 /* no reclassification while locks are held */
 static inline bool sock_allow_reclassification(const struct sock *csk)
 {
     struct sock *sk = (struct sock *)csk;
 
     return !sock_owned_by_user_nocheck(sk) &&
         !spin_is_locked(&sk->sk_lock.slock);
 }
 
 struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
               struct proto *prot, int kern);
 void sk_free(struct sock *sk);
 void sk_destruct(struct sock *sk);
 struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
 void sk_free_unlock_clone(struct sock *sk);
 
 struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
                  gfp_t priority);
 void __sock_wfree(struct sk_buff *skb);
 void sock_wfree(struct sk_buff *skb);
 struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
                  gfp_t priority);
 void skb_orphan_partial(struct sk_buff *skb);
 void sock_rfree(struct sk_buff *skb);
 void sock_efree(struct sk_buff *skb);
 #ifdef CONFIG_INET
 void sock_edemux(struct sk_buff *skb);
 void sock_pfree(struct sk_buff *skb);
 #else
 #define sock_edemux sock_efree
 #endif
 
 int sock_setsockopt(struct socket *sock, int level, int op,
             sockptr_t optval, unsigned int optlen);
 
 int sock_getsockopt(struct socket *sock, int level, int op,
             char __user *optval, int __user *optlen);
 int sock_gettstamp(struct socket *sock, void __user *userstamp,
            bool timeval, bool time32);
 struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
                      unsigned long data_len, int noblock,
                      int *errcode, int max_page_order);
 
 static inline 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, 0);
 }
 
 void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
 void sock_kfree_s(struct sock *sk, void *mem, int size);
 void sock_kzfree_s(struct sock *sk, void *mem, int size);
 void sk_send_sigurg(struct sock *sk);
 
 struct sockcm_cookie {
     u64 transmit_time;
     u32 mark;
     u16 tsflags;
 };
 
 static inline void sockcm_init(struct sockcm_cookie *sockc,
                    const struct sock *sk)
 {
     *sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
 }
 
 int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
              struct sockcm_cookie *sockc);
 int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
            struct sockcm_cookie *sockc);
 
 /*
  * Functions to fill in entries in struct proto_ops when a protocol
  * does not implement a particular function.
  */
 int sock_no_bind(struct socket *, struct sockaddr *, int);
 int sock_no_connect(struct socket *, struct sockaddr *, int, int);
 int sock_no_socketpair(struct socket *, struct socket *);
 int sock_no_accept(struct socket *, struct socket *, int, bool);
 int sock_no_getname(struct socket *, struct sockaddr *, int);
 int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
 int sock_no_listen(struct socket *, int);
 int sock_no_shutdown(struct socket *, int);
 int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
 int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
 int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
 int sock_no_mmap(struct file *file, struct socket *sock,
          struct vm_area_struct *vma);
 ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
              size_t size, int flags);
 ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
                 int offset, size_t size, int flags);
 
 /*
  * Functions to fill in entries in struct proto_ops when a protocol
  * uses the inet style.
  */
 int sock_common_getsockopt(struct socket *sock, int level, int optname,
                   char __user *optval, int __user *optlen);
 int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
             int flags);
 int sock_common_setsockopt(struct socket *sock, int level, int optname,
                sockptr_t optval, unsigned int optlen);
 
 void sk_common_release(struct sock *sk);
 
 /*
  *  Default socket callbacks and setup code
  */
 
 /* Initialise core socket variables */
 void sock_init_data(struct socket *sock, struct sock *sk);
 
 /*
  * Socket reference counting postulates.
  *
  * * Each user of socket SHOULD hold a reference count.
  * * Each access point to socket (an hash table bucket, reference from a list,
  *   running timer, skb in flight MUST hold a reference count.
  * * When reference count hits 0, it means it will never increase back.
  * * When reference count hits 0, it means that no references from
  *   outside exist to this socket and current process on current CPU
  *   is last user and may/should destroy this socket.
  * * sk_free is called from any context: process, BH, IRQ. When
  *   it is called, socket has no references from outside -> sk_free
  *   may release descendant resources allocated by the socket, but
  *   to the time when it is called, socket is NOT referenced by any
  *   hash tables, lists etc.
  * * Packets, delivered from outside (from network or from another process)
  *   and enqueued on receive/error queues SHOULD NOT grab reference count,
  *   when they sit in queue. Otherwise, packets will leak to hole, when
  *   socket is looked up by one cpu and unhasing is made by another CPU.
  *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
  *   (leak to backlog). Packet socket does all the processing inside
  *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
  *   use separate SMP lock, so that they are prone too.
  */
 
 /* Ungrab socket and destroy it, if it was the last reference. */
 static inline void sock_put(struct sock *sk)
 {
     if (refcount_dec_and_test(&sk->sk_refcnt))
         sk_free(sk);
 }
 /* Generic version of sock_put(), dealing with all sockets
  * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
  */
 void sock_gen_put(struct sock *sk);
 
 int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
              unsigned int trim_cap, bool refcounted);
 static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
                  const int nested)
 {
     return __sk_receive_skb(sk, skb, nested, 1, true);
 }
 
 static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
 {
     /* sk_tx_queue_mapping accept only upto a 16-bit value */
     if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
         return;
     sk->sk_tx_queue_mapping = tx_queue;
 }
 
 #define NO_QUEUE_MAPPING    USHRT_MAX
 
 static inline void sk_tx_queue_clear(struct sock *sk)
 {
     sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
 }
 
 static inline int sk_tx_queue_get(const struct sock *sk)
 {
     if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
         return sk->sk_tx_queue_mapping;
 
     return -1;
 }
 
 static inline void __sk_rx_queue_set(struct sock *sk,
                      const struct sk_buff *skb,
                      bool force_set)
 {
 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
     if (skb_rx_queue_recorded(skb)) {
         u16 rx_queue = skb_get_rx_queue(skb);
 
         if (force_set ||
             unlikely(READ_ONCE(sk->sk_rx_queue_mapping) != rx_queue))
             WRITE_ONCE(sk->sk_rx_queue_mapping, rx_queue);
     }
 #endif
 }
 
 static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
 {
     __sk_rx_queue_set(sk, skb, true);
 }
 
 static inline void sk_rx_queue_update(struct sock *sk, const struct sk_buff *skb)
 {
     __sk_rx_queue_set(sk, skb, false);
 }
 
 static inline void sk_rx_queue_clear(struct sock *sk)
 {
 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
     WRITE_ONCE(sk->sk_rx_queue_mapping, NO_QUEUE_MAPPING);
 #endif
 }
 
 static inline int sk_rx_queue_get(const struct sock *sk)
 {
 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
     if (sk) {
         int res = READ_ONCE(sk->sk_rx_queue_mapping);
 
         if (res != NO_QUEUE_MAPPING)
             return res;
     }
 #endif
 
     return -1;
 }
 
 static inline void sk_set_socket(struct sock *sk, struct socket *sock)
 {
     sk->sk_socket = sock;
 }
 
 static inline wait_queue_head_t *sk_sleep(struct sock *sk)
 {
     BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
     return &rcu_dereference_raw(sk->sk_wq)->wait;
 }
 /* Detach socket from process context.
  * Announce socket dead, detach it from wait queue and inode.
  * Note that parent inode held reference count on this struct sock,
  * we do not release it in this function, because protocol
  * probably wants some additional cleanups or even continuing
  * to work with this socket (TCP).
  */
 static inline void sock_orphan(struct sock *sk)
 {
     write_lock_bh(&sk->sk_callback_lock);
     sock_set_flag(sk, SOCK_DEAD);
     sk_set_socket(sk, NULL);
     sk->sk_wq  = NULL;
     write_unlock_bh(&sk->sk_callback_lock);
 }
 
 static inline void sock_graft(struct sock *sk, struct socket *parent)
 {
     WARN_ON(parent->sk);
     write_lock_bh(&sk->sk_callback_lock);
     rcu_assign_pointer(sk->sk_wq, &parent->wq);
     parent->sk = sk;
     sk_set_socket(sk, parent);
     sk->sk_uid = SOCK_INODE(parent)->i_uid;
     security_sock_graft(sk, parent);
     write_unlock_bh(&sk->sk_callback_lock);
 }
 
 kuid_t sock_i_uid(struct sock *sk);
 unsigned long sock_i_ino(struct sock *sk);
 
 static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
 {
     return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
 }
 
 static inline u32 net_tx_rndhash(void)
 {
     u32 v = prandom_u32();
 
     return v ?: 1;
 }
 
 static inline void sk_set_txhash(struct sock *sk)
 {
     /* This pairs with READ_ONCE() in skb_set_hash_from_sk() */
     WRITE_ONCE(sk->sk_txhash, net_tx_rndhash());
 }
 
 static inline bool sk_rethink_txhash(struct sock *sk)
 {
     if (sk->sk_txhash && sk->sk_txrehash == SOCK_TXREHASH_ENABLED) {
         sk_set_txhash(sk);
         return true;
     }
     return false;
 }
 
 static inline struct dst_entry *
 __sk_dst_get(struct sock *sk)
 {
     return rcu_dereference_check(sk->sk_dst_cache,
                      lockdep_sock_is_held(sk));
 }
 
 static inline struct dst_entry *
 sk_dst_get(struct sock *sk)
 {
     struct dst_entry *dst;
 
     rcu_read_lock();
     dst = rcu_dereference(sk->sk_dst_cache);
     if (dst && !atomic_inc_not_zero(&dst->__refcnt))
         dst = NULL;
     rcu_read_unlock();
     return dst;
 }
 
 static inline void __dst_negative_advice(struct sock *sk)
 {
     struct dst_entry *ndst, *dst = __sk_dst_get(sk);
 
     if (dst && dst->ops->negative_advice) {
         ndst = dst->ops->negative_advice(dst);
 
         if (ndst != dst) {
             rcu_assign_pointer(sk->sk_dst_cache, ndst);
             sk_tx_queue_clear(sk);
             sk->sk_dst_pending_confirm = 0;
         }
     }
 }
 
 static inline void dst_negative_advice(struct sock *sk)
 {
     sk_rethink_txhash(sk);
     __dst_negative_advice(sk);
 }
 
 static inline void
 __sk_dst_set(struct sock *sk, struct dst_entry *dst)
 {
     struct dst_entry *old_dst;
 
     sk_tx_queue_clear(sk);
     sk->sk_dst_pending_confirm = 0;
     old_dst = rcu_dereference_protected(sk->sk_dst_cache,
                         lockdep_sock_is_held(sk));
     rcu_assign_pointer(sk->sk_dst_cache, dst);
     dst_release(old_dst);
 }
 
 static inline void
 sk_dst_set(struct sock *sk, struct dst_entry *dst)
 {
     struct dst_entry *old_dst;
 
     sk_tx_queue_clear(sk);
     sk->sk_dst_pending_confirm = 0;
     old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
     dst_release(old_dst);
 }
 
 static inline void
 __sk_dst_reset(struct sock *sk)
 {
     __sk_dst_set(sk, NULL);
 }
 
 static inline void
 sk_dst_reset(struct sock *sk)
 {
     sk_dst_set(sk, NULL);
 }
 
 struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
 
 struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
 
 static inline void sk_dst_confirm(struct sock *sk)
 {
     if (!READ_ONCE(sk->sk_dst_pending_confirm))
         WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
 }
 
 static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
 {
     if (skb_get_dst_pending_confirm(skb)) {
         struct sock *sk = skb->sk;
 
         if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
             WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
         neigh_confirm(n);
     }
 }
 
 bool sk_mc_loop(struct sock *sk);
 
 static inline bool sk_can_gso(const struct sock *sk)
 {
     return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
 }
 
 void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
 
 static inline void sk_gso_disable(struct sock *sk)
 {
     sk->sk_gso_disabled = 1;
     sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
 }
 
 static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
                        struct iov_iter *from, char *to,
                        int copy, int offset)
 {
     if (skb->ip_summed == CHECKSUM_NONE) {
         __wsum csum = 0;
         if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
             return -EFAULT;
         skb->csum = csum_block_add(skb->csum, csum, offset);
     } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
         if (!copy_from_iter_full_nocache(to, copy, from))
             return -EFAULT;
     } else if (!copy_from_iter_full(to, copy, from))
         return -EFAULT;
 
     return 0;
 }
 
 static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
                        struct iov_iter *from, int copy)
 {
     int err, offset = skb->len;
 
     err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
                        copy, offset);
     if (err)
         __skb_trim(skb, offset);
 
     return err;
 }
 
 static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
                        struct sk_buff *skb,
                        struct page *page,
                        int off, int copy)
 {
     int err;
 
     err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
                        copy, skb->len);
     if (err)
         return err;
 
     skb_len_add(skb, copy);
     sk_wmem_queued_add(sk, copy);
     sk_mem_charge(sk, copy);
     return 0;
 }
 
 /**
  * sk_wmem_alloc_get - returns write allocations
  * @sk: socket
  *
  * Return: sk_wmem_alloc minus initial offset of one
  */
 static inline int sk_wmem_alloc_get(const struct sock *sk)
 {
     return refcount_read(&sk->sk_wmem_alloc) - 1;
 }
 
 /**
  * sk_rmem_alloc_get - returns read allocations
  * @sk: socket
  *
  * Return: sk_rmem_alloc
  */
 static inline int sk_rmem_alloc_get(const struct sock *sk)
 {
     return atomic_read(&sk->sk_rmem_alloc);
 }
 
 /**
  * sk_has_allocations - check if allocations are outstanding
  * @sk: socket
  *
  * Return: true if socket has write or read allocations
  */
 static inline bool sk_has_allocations(const struct sock *sk)
 {
     return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
 }
 
 /**
  * skwq_has_sleeper - check if there are any waiting processes
  * @wq: struct socket_wq
  *
  * Return: true if socket_wq has waiting processes
  *
  * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
  * barrier call. They were added due to the race found within the tcp code.
  *
  * Consider following tcp code paths::
  *
  *   CPU1                CPU2
  *   sys_select          receive packet
  *   ...                 ...
  *   __add_wait_queue    update tp->rcv_nxt
  *   ...                 ...
  *   tp->rcv_nxt check   sock_def_readable
  *   ...                 {
  *   schedule               rcu_read_lock();
  *                          wq = rcu_dereference(sk->sk_wq);
  *                          if (wq && waitqueue_active(&wq->wait))
  *                              wake_up_interruptible(&wq->wait)
  *                          ...
  *                       }
  *
  * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
  * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
  * could then endup calling schedule and sleep forever if there are no more
  * data on the socket.
  *
  */
 static inline bool skwq_has_sleeper(struct socket_wq *wq)
 {
     return wq && wq_has_sleeper(&wq->wait);
 }
 
 /**
  * sock_poll_wait - place memory barrier behind the poll_wait call.
  * @filp:           file
  * @sock:           socket to wait on
  * @p:              poll_table
  *
  * See the comments in the wq_has_sleeper function.
  */
 static inline void sock_poll_wait(struct file *filp, struct socket *sock,
                   poll_table *p)
 {
     if (!poll_does_not_wait(p)) {
         poll_wait(filp, &sock->wq.wait, p);
         /* We need to be sure we are in sync with the
          * socket flags modification.
          *
          * This memory barrier is paired in the wq_has_sleeper.
          */
         smp_mb();
     }
 }
 
 static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
 {
     /* This pairs with WRITE_ONCE() in sk_set_txhash() */
     u32 txhash = READ_ONCE(sk->sk_txhash);
 
     if (txhash) {
         skb->l4_hash = 1;
         skb->hash = txhash;
     }
 }
 
 void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
 
 /*
  *  Queue a received datagram if it will fit. Stream and sequenced
  *  protocols can't normally use this as they need to fit buffers in
  *  and play with them.
  *
  *  Inlined as it's very short and called for pretty much every
  *  packet ever received.
  */
 static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
 {
     skb_orphan(skb);
     skb->sk = sk;
     skb->destructor = sock_rfree;
     atomic_add(skb->truesize, &sk->sk_rmem_alloc);
     sk_mem_charge(sk, skb->truesize);
 }
 
 static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
 {
     if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
         skb_orphan(skb);
         skb->destructor = sock_efree;
         skb->sk = sk;
         return true;
     }
     return false;
 }
 
 static inline void skb_prepare_for_gro(struct sk_buff *skb)
 {
     if (skb->destructor != sock_wfree) {
         skb_orphan(skb);
         return;
     }
     skb->slow_gro = 1;
 }
 
 void sk_reset_timer(struct sock *sk, struct timer_list *timer,
             unsigned long expires);
 
 void sk_stop_timer(struct sock *sk, struct timer_list *timer);
 
 void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer);
 
 int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
             struct sk_buff *skb, unsigned int flags,
             void (*destructor)(struct sock *sk,
                        struct sk_buff *skb));
 int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
 
 int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
                   enum skb_drop_reason *reason);
 
 static inline int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
 {
     return sock_queue_rcv_skb_reason(sk, skb, NULL);
 }
 
 int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
 struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
 
 /*
  *  Recover an error report and clear atomically
  */
 
 static inline int sock_error(struct sock *sk)
 {
     int err;
 
     /* Avoid an atomic operation for the common case.
      * This is racy since another cpu/thread can change sk_err under us.
      */
     if (likely(data_race(!sk->sk_err)))
         return 0;
 
     err = xchg(&sk->sk_err, 0);
     return -err;
 }
 
 void sk_error_report(struct sock *sk);
 
 static inline unsigned long sock_wspace(struct sock *sk)
 {
     int amt = 0;
 
     if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
         amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
         if (amt < 0)
             amt = 0;
     }
     return amt;
 }
 
 /* Note:
  *  We use sk->sk_wq_raw, from contexts knowing this
  *  pointer is not NULL and cannot disappear/change.
  */
 static inline void sk_set_bit(int nr, struct sock *sk)
 {
     if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
         !sock_flag(sk, SOCK_FASYNC))
         return;
 
     set_bit(nr, &sk->sk_wq_raw->flags);
 }
 
 static inline void sk_clear_bit(int nr, struct sock *sk)
 {
     if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
         !sock_flag(sk, SOCK_FASYNC))
         return;
 
     clear_bit(nr, &sk->sk_wq_raw->flags);
 }
 
 static inline void sk_wake_async(const struct sock *sk, int how, int band)
 {
     if (sock_flag(sk, SOCK_FASYNC)) {
         rcu_read_lock();
         sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
         rcu_read_unlock();
     }
 }
 
 /* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
  * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
  * Note: for send buffers, TCP works better if we can build two skbs at
  * minimum.
  */
 #define TCP_SKB_MIN_TRUESIZE    (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
 
 #define SOCK_MIN_SNDBUF     (TCP_SKB_MIN_TRUESIZE * 2)
 #define SOCK_MIN_RCVBUF      TCP_SKB_MIN_TRUESIZE
 
 static inline void sk_stream_moderate_sndbuf(struct sock *sk)
 {
     u32 val;
 
     if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
         return;
 
     val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
     val = max_t(u32, val, sk_unused_reserved_mem(sk));
 
     WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
 }
 
 /**
  * sk_page_frag - return an appropriate page_frag
  * @sk: socket
  *
  * Use the per task page_frag instead of the per socket one for
  * optimization when we know that we're in process context and own
  * everything that's associated with %current.
  *
  * Both direct reclaim and page faults can nest inside other
  * socket operations and end up recursing into sk_page_frag()
  * while it's already in use: explicitly avoid task page_frag
  * usage if the caller is potentially doing any of them.
  * This assumes that page fault handlers use the GFP_NOFS flags.
  *
  * Return: a per task page_frag if context allows that,
  * otherwise a per socket one.
  */
 static inline struct page_frag *sk_page_frag(struct sock *sk)
 {
     if ((sk->sk_allocation & (__GFP_DIRECT_RECLAIM | __GFP_MEMALLOC | __GFP_FS)) ==
         (__GFP_DIRECT_RECLAIM | __GFP_FS))
         return &current->task_frag;
 
     return &sk->sk_frag;
 }
 
 bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
 
 /*
  *  Default write policy as shown to user space via poll/select/SIGIO
  */
 static inline bool sock_writeable(const struct sock *sk)
 {
     return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
 }
 
 static inline gfp_t gfp_any(void)
 {
     return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
 }
 
 static inline gfp_t gfp_memcg_charge(void)
 {
     return in_softirq() ? GFP_NOWAIT : GFP_KERNEL;
 }
 
 static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
 {
     return noblock ? 0 : sk->sk_rcvtimeo;
 }
 
 static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
 {
     return noblock ? 0 : sk->sk_sndtimeo;
 }
 
 static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
 {
     int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
 
     return v ?: 1;
 }
 
 /* Alas, with timeout socket operations are not restartable.
  * Compare this to poll().
  */
 static inline int sock_intr_errno(long timeo)
 {
     return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
 }
 
 struct sock_skb_cb {
     u32 dropcount;
 };
 
 /* Store sock_skb_cb at the end of skb->cb[] so protocol families
  * using skb->cb[] would keep using it directly and utilize its
  * alignement guarantee.
  */
 #define SOCK_SKB_CB_OFFSET ((sizeof_field(struct sk_buff, cb) - \
                 sizeof(struct sock_skb_cb)))
 
 #define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
                 SOCK_SKB_CB_OFFSET))
 
 #define sock_skb_cb_check_size(size) \
     BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
 
 static inline void
 sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
 {
     SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
                         atomic_read(&sk->sk_drops) : 0;
 }
 
 static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
 {
     int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
 
     atomic_add(segs, &sk->sk_drops);
 }
 
 static inline ktime_t sock_read_timestamp(struct sock *sk)
 {
 #if BITS_PER_LONG==32
     unsigned int seq;
     ktime_t kt;
 
     do {
         seq = read_seqbegin(&sk->sk_stamp_seq);
         kt = sk->sk_stamp;
     } while (read_seqretry(&sk->sk_stamp_seq, seq));
 
     return kt;
 #else
     return READ_ONCE(sk->sk_stamp);
 #endif
 }
 
 static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
 {
 #if BITS_PER_LONG==32
     write_seqlock(&sk->sk_stamp_seq);
     sk->sk_stamp = kt;
     write_sequnlock(&sk->sk_stamp_seq);
 #else
     WRITE_ONCE(sk->sk_stamp, kt);
 #endif
 }
 
 void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
                struct sk_buff *skb);
 void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
                  struct sk_buff *skb);
 
 static inline void
 sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
 {
     ktime_t kt = skb->tstamp;
     struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
 
     /*
      * generate control messages if
      * - receive time stamping in software requested
      * - software time stamp available and wanted
      * - hardware time stamps available and wanted
      */
     if (sock_flag(sk, SOCK_RCVTSTAMP) ||
         (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
         (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
         (hwtstamps->hwtstamp &&
          (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
         __sock_recv_timestamp(msg, sk, skb);
     else
         sock_write_timestamp(sk, kt);
 
     if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
         __sock_recv_wifi_status(msg, sk, skb);
 }
 
 void __sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
                struct sk_buff *skb);
 
 #define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
 static inline void sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
                    struct sk_buff *skb)
 {
 #define FLAGS_RECV_CMSGS ((1UL << SOCK_RXQ_OVFL)            | \
                (1UL << SOCK_RCVTSTAMP)          | \
                (1UL << SOCK_RCVMARK))
 #define TSFLAGS_ANY   (SOF_TIMESTAMPING_SOFTWARE            | \
                SOF_TIMESTAMPING_RAW_HARDWARE)
 
     if (sk->sk_flags & FLAGS_RECV_CMSGS || sk->sk_tsflags & TSFLAGS_ANY)
         __sock_recv_cmsgs(msg, sk, skb);
     else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
         sock_write_timestamp(sk, skb->tstamp);
     else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
         sock_write_timestamp(sk, 0);
 }
 
 void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
 
 /**
  * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
  * @sk:     socket sending this packet
  * @tsflags:    timestamping flags to use
  * @tx_flags:   completed with instructions for time stamping
  * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
  *
  * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
  */
 static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
                       __u8 *tx_flags, __u32 *tskey)
 {
     if (unlikely(tsflags)) {
         __sock_tx_timestamp(tsflags, tx_flags);
         if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
             tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
             *tskey = atomic_inc_return(&sk->sk_tskey) - 1;
     }
     if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
         *tx_flags |= SKBTX_WIFI_STATUS;
 }
 
 static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
                      __u8 *tx_flags)
 {
     _sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
 }
 
 static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
 {
     _sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
                &skb_shinfo(skb)->tskey);
 }
 
 static inline bool sk_is_tcp(const struct sock *sk)
 {
     return sk->sk_type == SOCK_STREAM && sk->sk_protocol == IPPROTO_TCP;
 }
 
 /**
  * sk_eat_skb - Release a skb if it is no longer needed
  * @sk: socket to eat this skb from
  * @skb: socket buffer to eat
  *
  * This routine must be called with interrupts disabled or with the socket
  * locked so that the sk_buff queue operation is ok.
 */
 static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
 {
     __skb_unlink(skb, &sk->sk_receive_queue);
     __kfree_skb(skb);
 }
 
 static inline bool
 skb_sk_is_prefetched(struct sk_buff *skb)
 {
 #ifdef CONFIG_INET
     return skb->destructor == sock_pfree;
 #else
     return false;
 #endif /* CONFIG_INET */
 }
 
 /* This helper checks if a socket is a full socket,
  * ie _not_ a timewait or request socket.
  */
 static inline bool sk_fullsock(const struct sock *sk)
 {
     return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
 }
 
 static inline bool
 sk_is_refcounted(struct sock *sk)
 {
     /* Only full sockets have sk->sk_flags. */
     return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
 }
 
 /**
  * skb_steal_sock - steal a socket from an sk_buff
  * @skb: sk_buff to steal the socket from
  * @refcounted: is set to true if the socket is reference-counted
  */
 static inline struct sock *
 skb_steal_sock(struct sk_buff *skb, bool *refcounted)
 {
     if (skb->sk) {
         struct sock *sk = skb->sk;
 
         *refcounted = true;
         if (skb_sk_is_prefetched(skb))
             *refcounted = sk_is_refcounted(sk);
         skb->destructor = NULL;
         skb->sk = NULL;
         return sk;
     }
     *refcounted = false;
     return NULL;
 }
 
 /* Checks if this SKB belongs to an HW offloaded socket
  * and whether any SW fallbacks are required based on dev.
  * Check decrypted mark in case skb_orphan() cleared socket.
  */
 static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
                            struct net_device *dev)
 {
 #ifdef CONFIG_SOCK_VALIDATE_XMIT
     struct sock *sk = skb->sk;
 
     if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
         skb = sk->sk_validate_xmit_skb(sk, dev, skb);
 #ifdef CONFIG_TLS_DEVICE
     } else if (unlikely(skb->decrypted)) {
         pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
         kfree_skb(skb);
         skb = NULL;
 #endif
     }
 #endif
 
     return skb;
 }
 
 /* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
  * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
  */
 static inline bool sk_listener(const struct sock *sk)
 {
     return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
 }
 
 void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
 int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
                int type);
 
 bool sk_ns_capable(const struct sock *sk,
            struct user_namespace *user_ns, int cap);
 bool sk_capable(const struct sock *sk, int cap);
 bool sk_net_capable(const struct sock *sk, int cap);
 
 void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
 
 /* 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)
 
 extern __u32 sysctl_wmem_max;
 extern __u32 sysctl_rmem_max;
 
 extern int sysctl_tstamp_allow_data;
 extern int sysctl_optmem_max;
 
 extern __u32 sysctl_wmem_default;
 extern __u32 sysctl_rmem_default;
 
 #define SKB_FRAG_PAGE_ORDER get_order(32768)
 DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
 
 static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
 {
     /* Does this proto have per netns sysctl_wmem ? */
     if (proto->sysctl_wmem_offset)
         return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset));
 
     return READ_ONCE(*proto->sysctl_wmem);
 }
 
 static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
 {
     /* Does this proto have per netns sysctl_rmem ? */
     if (proto->sysctl_rmem_offset)
         return READ_ONCE(*(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset));
 
     return READ_ONCE(*proto->sysctl_rmem);
 }
 
 /* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
  * Some wifi drivers need to tweak it to get more chunks.
  * They can use this helper from their ndo_start_xmit()
  */
 static inline void sk_pacing_shift_update(struct sock *sk, int val)
 {
     if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
         return;
     WRITE_ONCE(sk->sk_pacing_shift, val);
 }
 
 /* if a socket is bound to a device, check that the given device
  * index is either the same or that the socket is bound to an L3
  * master device and the given device index is also enslaved to
  * that L3 master
  */
 static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
 {
     int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
     int mdif;
 
     if (!bound_dev_if || bound_dev_if == dif)
         return true;
 
     mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
     if (mdif && mdif == bound_dev_if)
         return true;
 
     return false;
 }
 
 void sock_def_readable(struct sock *sk);
 
 int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
 void sock_set_timestamp(struct sock *sk, int optname, bool valbool);
 int sock_set_timestamping(struct sock *sk, int optname,
               struct so_timestamping timestamping);
 
 void sock_enable_timestamps(struct sock *sk);
 void sock_no_linger(struct sock *sk);
 void sock_set_keepalive(struct sock *sk);
 void sock_set_priority(struct sock *sk, u32 priority);
 void sock_set_rcvbuf(struct sock *sk, int val);
 void sock_set_mark(struct sock *sk, u32 val);
 void sock_set_reuseaddr(struct sock *sk);
 void sock_set_reuseport(struct sock *sk);
 void sock_set_sndtimeo(struct sock *sk, s64 secs);
 
 int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
 
 int sock_get_timeout(long timeo, void *optval, bool old_timeval);
 int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
                sockptr_t optval, int optlen, bool old_timeval);
 
 static inline bool sk_is_readable(struct sock *sk)
 {
     if (sk->sk_prot->sock_is_readable)
         return sk->sk_prot->sock_is_readable(sk);
     return false;
 }
 #endif  /* _SOCK_H */