cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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sock.h (83572B)


      1/* SPDX-License-Identifier: GPL-2.0-or-later */
      2/*
      3 * INET		An implementation of the TCP/IP protocol suite for the LINUX
      4 *		operating system.  INET is implemented using the  BSD Socket
      5 *		interface as the means of communication with the user level.
      6 *
      7 *		Definitions for the AF_INET socket handler.
      8 *
      9 * Version:	@(#)sock.h	1.0.4	05/13/93
     10 *
     11 * Authors:	Ross Biro
     12 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
     13 *		Corey Minyard <wf-rch!minyard@relay.EU.net>
     14 *		Florian La Roche <flla@stud.uni-sb.de>
     15 *
     16 * Fixes:
     17 *		Alan Cox	:	Volatiles in skbuff pointers. See
     18 *					skbuff comments. May be overdone,
     19 *					better to prove they can be removed
     20 *					than the reverse.
     21 *		Alan Cox	:	Added a zapped field for tcp to note
     22 *					a socket is reset and must stay shut up
     23 *		Alan Cox	:	New fields for options
     24 *	Pauline Middelink	:	identd support
     25 *		Alan Cox	:	Eliminate low level recv/recvfrom
     26 *		David S. Miller	:	New socket lookup architecture.
     27 *              Steve Whitehouse:       Default routines for sock_ops
     28 *              Arnaldo C. Melo :	removed net_pinfo, tp_pinfo and made
     29 *              			protinfo be just a void pointer, as the
     30 *              			protocol specific parts were moved to
     31 *              			respective headers and ipv4/v6, etc now
     32 *              			use private slabcaches for its socks
     33 *              Pedro Hortas	:	New flags field for socket options
     34 */
     35#ifndef _SOCK_H
     36#define _SOCK_H
     37
     38#include <linux/hardirq.h>
     39#include <linux/kernel.h>
     40#include <linux/list.h>
     41#include <linux/list_nulls.h>
     42#include <linux/timer.h>
     43#include <linux/cache.h>
     44#include <linux/bitops.h>
     45#include <linux/lockdep.h>
     46#include <linux/netdevice.h>
     47#include <linux/skbuff.h>	/* struct sk_buff */
     48#include <linux/mm.h>
     49#include <linux/security.h>
     50#include <linux/slab.h>
     51#include <linux/uaccess.h>
     52#include <linux/page_counter.h>
     53#include <linux/memcontrol.h>
     54#include <linux/static_key.h>
     55#include <linux/sched.h>
     56#include <linux/wait.h>
     57#include <linux/cgroup-defs.h>
     58#include <linux/rbtree.h>
     59#include <linux/rculist_nulls.h>
     60#include <linux/poll.h>
     61#include <linux/sockptr.h>
     62#include <linux/indirect_call_wrapper.h>
     63#include <linux/atomic.h>
     64#include <linux/refcount.h>
     65#include <linux/llist.h>
     66#include <net/dst.h>
     67#include <net/checksum.h>
     68#include <net/tcp_states.h>
     69#include <linux/net_tstamp.h>
     70#include <net/l3mdev.h>
     71#include <uapi/linux/socket.h>
     72
     73/*
     74 * This structure really needs to be cleaned up.
     75 * Most of it is for TCP, and not used by any of
     76 * the other protocols.
     77 */
     78
     79/* Define this to get the SOCK_DBG debugging facility. */
     80#define SOCK_DEBUGGING
     81#ifdef SOCK_DEBUGGING
     82#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
     83					printk(KERN_DEBUG msg); } while (0)
     84#else
     85/* Validate arguments and do nothing */
     86static inline __printf(2, 3)
     87void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
     88{
     89}
     90#endif
     91
     92/* This is the per-socket lock.  The spinlock provides a synchronization
     93 * between user contexts and software interrupt processing, whereas the
     94 * mini-semaphore synchronizes multiple users amongst themselves.
     95 */
     96typedef struct {
     97	spinlock_t		slock;
     98	int			owned;
     99	wait_queue_head_t	wq;
    100	/*
    101	 * We express the mutex-alike socket_lock semantics
    102	 * to the lock validator by explicitly managing
    103	 * the slock as a lock variant (in addition to
    104	 * the slock itself):
    105	 */
    106#ifdef CONFIG_DEBUG_LOCK_ALLOC
    107	struct lockdep_map dep_map;
    108#endif
    109} socket_lock_t;
    110
    111struct sock;
    112struct proto;
    113struct net;
    114
    115typedef __u32 __bitwise __portpair;
    116typedef __u64 __bitwise __addrpair;
    117
    118/**
    119 *	struct sock_common - minimal network layer representation of sockets
    120 *	@skc_daddr: Foreign IPv4 addr
    121 *	@skc_rcv_saddr: Bound local IPv4 addr
    122 *	@skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr
    123 *	@skc_hash: hash value used with various protocol lookup tables
    124 *	@skc_u16hashes: two u16 hash values used by UDP lookup tables
    125 *	@skc_dport: placeholder for inet_dport/tw_dport
    126 *	@skc_num: placeholder for inet_num/tw_num
    127 *	@skc_portpair: __u32 union of @skc_dport & @skc_num
    128 *	@skc_family: network address family
    129 *	@skc_state: Connection state
    130 *	@skc_reuse: %SO_REUSEADDR setting
    131 *	@skc_reuseport: %SO_REUSEPORT setting
    132 *	@skc_ipv6only: socket is IPV6 only
    133 *	@skc_net_refcnt: socket is using net ref counting
    134 *	@skc_bound_dev_if: bound device index if != 0
    135 *	@skc_bind_node: bind hash linkage for various protocol lookup tables
    136 *	@skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
    137 *	@skc_prot: protocol handlers inside a network family
    138 *	@skc_net: reference to the network namespace of this socket
    139 *	@skc_v6_daddr: IPV6 destination address
    140 *	@skc_v6_rcv_saddr: IPV6 source address
    141 *	@skc_cookie: socket's cookie value
    142 *	@skc_node: main hash linkage for various protocol lookup tables
    143 *	@skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
    144 *	@skc_tx_queue_mapping: tx queue number for this connection
    145 *	@skc_rx_queue_mapping: rx queue number for this connection
    146 *	@skc_flags: place holder for sk_flags
    147 *		%SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
    148 *		%SO_OOBINLINE settings, %SO_TIMESTAMPING settings
    149 *	@skc_listener: connection request listener socket (aka rsk_listener)
    150 *		[union with @skc_flags]
    151 *	@skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row
    152 *		[union with @skc_flags]
    153 *	@skc_incoming_cpu: record/match cpu processing incoming packets
    154 *	@skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled)
    155 *		[union with @skc_incoming_cpu]
    156 *	@skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number
    157 *		[union with @skc_incoming_cpu]
    158 *	@skc_refcnt: reference count
    159 *
    160 *	This is the minimal network layer representation of sockets, the header
    161 *	for struct sock and struct inet_timewait_sock.
    162 */
    163struct sock_common {
    164	union {
    165		__addrpair	skc_addrpair;
    166		struct {
    167			__be32	skc_daddr;
    168			__be32	skc_rcv_saddr;
    169		};
    170	};
    171	union  {
    172		unsigned int	skc_hash;
    173		__u16		skc_u16hashes[2];
    174	};
    175	/* skc_dport && skc_num must be grouped as well */
    176	union {
    177		__portpair	skc_portpair;
    178		struct {
    179			__be16	skc_dport;
    180			__u16	skc_num;
    181		};
    182	};
    183
    184	unsigned short		skc_family;
    185	volatile unsigned char	skc_state;
    186	unsigned char		skc_reuse:4;
    187	unsigned char		skc_reuseport:1;
    188	unsigned char		skc_ipv6only:1;
    189	unsigned char		skc_net_refcnt:1;
    190	int			skc_bound_dev_if;
    191	union {
    192		struct hlist_node	skc_bind_node;
    193		struct hlist_node	skc_portaddr_node;
    194	};
    195	struct proto		*skc_prot;
    196	possible_net_t		skc_net;
    197
    198#if IS_ENABLED(CONFIG_IPV6)
    199	struct in6_addr		skc_v6_daddr;
    200	struct in6_addr		skc_v6_rcv_saddr;
    201#endif
    202
    203	atomic64_t		skc_cookie;
    204
    205	/* following fields are padding to force
    206	 * offset(struct sock, sk_refcnt) == 128 on 64bit arches
    207	 * assuming IPV6 is enabled. We use this padding differently
    208	 * for different kind of 'sockets'
    209	 */
    210	union {
    211		unsigned long	skc_flags;
    212		struct sock	*skc_listener; /* request_sock */
    213		struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
    214	};
    215	/*
    216	 * fields between dontcopy_begin/dontcopy_end
    217	 * are not copied in sock_copy()
    218	 */
    219	/* private: */
    220	int			skc_dontcopy_begin[0];
    221	/* public: */
    222	union {
    223		struct hlist_node	skc_node;
    224		struct hlist_nulls_node skc_nulls_node;
    225	};
    226	unsigned short		skc_tx_queue_mapping;
    227#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
    228	unsigned short		skc_rx_queue_mapping;
    229#endif
    230	union {
    231		int		skc_incoming_cpu;
    232		u32		skc_rcv_wnd;
    233		u32		skc_tw_rcv_nxt; /* struct tcp_timewait_sock  */
    234	};
    235
    236	refcount_t		skc_refcnt;
    237	/* private: */
    238	int                     skc_dontcopy_end[0];
    239	union {
    240		u32		skc_rxhash;
    241		u32		skc_window_clamp;
    242		u32		skc_tw_snd_nxt; /* struct tcp_timewait_sock */
    243	};
    244	/* public: */
    245};
    246
    247struct bpf_local_storage;
    248struct sk_filter;
    249
    250/**
    251  *	struct sock - network layer representation of sockets
    252  *	@__sk_common: shared layout with inet_timewait_sock
    253  *	@sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
    254  *	@sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
    255  *	@sk_lock:	synchronizer
    256  *	@sk_kern_sock: True if sock is using kernel lock classes
    257  *	@sk_rcvbuf: size of receive buffer in bytes
    258  *	@sk_wq: sock wait queue and async head
    259  *	@sk_rx_dst: receive input route used by early demux
    260  *	@sk_rx_dst_ifindex: ifindex for @sk_rx_dst
    261  *	@sk_rx_dst_cookie: cookie for @sk_rx_dst
    262  *	@sk_dst_cache: destination cache
    263  *	@sk_dst_pending_confirm: need to confirm neighbour
    264  *	@sk_policy: flow policy
    265  *	@sk_receive_queue: incoming packets
    266  *	@sk_wmem_alloc: transmit queue bytes committed
    267  *	@sk_tsq_flags: TCP Small Queues flags
    268  *	@sk_write_queue: Packet sending queue
    269  *	@sk_omem_alloc: "o" is "option" or "other"
    270  *	@sk_wmem_queued: persistent queue size
    271  *	@sk_forward_alloc: space allocated forward
    272  *	@sk_reserved_mem: space reserved and non-reclaimable for the socket
    273  *	@sk_napi_id: id of the last napi context to receive data for sk
    274  *	@sk_ll_usec: usecs to busypoll when there is no data
    275  *	@sk_allocation: allocation mode
    276  *	@sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
    277  *	@sk_pacing_status: Pacing status (requested, handled by sch_fq)
    278  *	@sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
    279  *	@sk_sndbuf: size of send buffer in bytes
    280  *	@__sk_flags_offset: empty field used to determine location of bitfield
    281  *	@sk_padding: unused element for alignment
    282  *	@sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
    283  *	@sk_no_check_rx: allow zero checksum in RX packets
    284  *	@sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
    285  *	@sk_gso_disabled: if set, NETIF_F_GSO_MASK is forbidden.
    286  *	@sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
    287  *	@sk_gso_max_size: Maximum GSO segment size to build
    288  *	@sk_gso_max_segs: Maximum number of GSO segments
    289  *	@sk_pacing_shift: scaling factor for TCP Small Queues
    290  *	@sk_lingertime: %SO_LINGER l_linger setting
    291  *	@sk_backlog: always used with the per-socket spinlock held
    292  *	@sk_callback_lock: used with the callbacks in the end of this struct
    293  *	@sk_error_queue: rarely used
    294  *	@sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
    295  *			  IPV6_ADDRFORM for instance)
    296  *	@sk_err: last error
    297  *	@sk_err_soft: errors that don't cause failure but are the cause of a
    298  *		      persistent failure not just 'timed out'
    299  *	@sk_drops: raw/udp drops counter
    300  *	@sk_ack_backlog: current listen backlog
    301  *	@sk_max_ack_backlog: listen backlog set in listen()
    302  *	@sk_uid: user id of owner
    303  *	@sk_prefer_busy_poll: prefer busypolling over softirq processing
    304  *	@sk_busy_poll_budget: napi processing budget when busypolling
    305  *	@sk_priority: %SO_PRIORITY setting
    306  *	@sk_type: socket type (%SOCK_STREAM, etc)
    307  *	@sk_protocol: which protocol this socket belongs in this network family
    308  *	@sk_peer_lock: lock protecting @sk_peer_pid and @sk_peer_cred
    309  *	@sk_peer_pid: &struct pid for this socket's peer
    310  *	@sk_peer_cred: %SO_PEERCRED setting
    311  *	@sk_rcvlowat: %SO_RCVLOWAT setting
    312  *	@sk_rcvtimeo: %SO_RCVTIMEO setting
    313  *	@sk_sndtimeo: %SO_SNDTIMEO setting
    314  *	@sk_txhash: computed flow hash for use on transmit
    315  *	@sk_txrehash: enable TX hash rethink
    316  *	@sk_filter: socket filtering instructions
    317  *	@sk_timer: sock cleanup timer
    318  *	@sk_stamp: time stamp of last packet received
    319  *	@sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
    320  *	@sk_tsflags: SO_TIMESTAMPING flags
    321  *	@sk_bind_phc: SO_TIMESTAMPING bind PHC index of PTP virtual clock
    322  *	              for timestamping
    323  *	@sk_tskey: counter to disambiguate concurrent tstamp requests
    324  *	@sk_zckey: counter to order MSG_ZEROCOPY notifications
    325  *	@sk_socket: Identd and reporting IO signals
    326  *	@sk_user_data: RPC layer private data
    327  *	@sk_frag: cached page frag
    328  *	@sk_peek_off: current peek_offset value
    329  *	@sk_send_head: front of stuff to transmit
    330  *	@tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head]
    331  *	@sk_security: used by security modules
    332  *	@sk_mark: generic packet mark
    333  *	@sk_cgrp_data: cgroup data for this cgroup
    334  *	@sk_memcg: this socket's memory cgroup association
    335  *	@sk_write_pending: a write to stream socket waits to start
    336  *	@sk_state_change: callback to indicate change in the state of the sock
    337  *	@sk_data_ready: callback to indicate there is data to be processed
    338  *	@sk_write_space: callback to indicate there is bf sending space available
    339  *	@sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
    340  *	@sk_backlog_rcv: callback to process the backlog
    341  *	@sk_validate_xmit_skb: ptr to an optional validate function
    342  *	@sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
    343  *	@sk_reuseport_cb: reuseport group container
    344  *	@sk_bpf_storage: ptr to cache and control for bpf_sk_storage
    345  *	@sk_rcu: used during RCU grace period
    346  *	@sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
    347  *	@sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
    348  *	@sk_txtime_report_errors: set report errors mode for SO_TXTIME
    349  *	@sk_txtime_unused: unused txtime flags
    350  *	@ns_tracker: tracker for netns reference
    351  */
    352struct sock {
    353	/*
    354	 * Now struct inet_timewait_sock also uses sock_common, so please just
    355	 * don't add nothing before this first member (__sk_common) --acme
    356	 */
    357	struct sock_common	__sk_common;
    358#define sk_node			__sk_common.skc_node
    359#define sk_nulls_node		__sk_common.skc_nulls_node
    360#define sk_refcnt		__sk_common.skc_refcnt
    361#define sk_tx_queue_mapping	__sk_common.skc_tx_queue_mapping
    362#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
    363#define sk_rx_queue_mapping	__sk_common.skc_rx_queue_mapping
    364#endif
    365
    366#define sk_dontcopy_begin	__sk_common.skc_dontcopy_begin
    367#define sk_dontcopy_end		__sk_common.skc_dontcopy_end
    368#define sk_hash			__sk_common.skc_hash
    369#define sk_portpair		__sk_common.skc_portpair
    370#define sk_num			__sk_common.skc_num
    371#define sk_dport		__sk_common.skc_dport
    372#define sk_addrpair		__sk_common.skc_addrpair
    373#define sk_daddr		__sk_common.skc_daddr
    374#define sk_rcv_saddr		__sk_common.skc_rcv_saddr
    375#define sk_family		__sk_common.skc_family
    376#define sk_state		__sk_common.skc_state
    377#define sk_reuse		__sk_common.skc_reuse
    378#define sk_reuseport		__sk_common.skc_reuseport
    379#define sk_ipv6only		__sk_common.skc_ipv6only
    380#define sk_net_refcnt		__sk_common.skc_net_refcnt
    381#define sk_bound_dev_if		__sk_common.skc_bound_dev_if
    382#define sk_bind_node		__sk_common.skc_bind_node
    383#define sk_prot			__sk_common.skc_prot
    384#define sk_net			__sk_common.skc_net
    385#define sk_v6_daddr		__sk_common.skc_v6_daddr
    386#define sk_v6_rcv_saddr	__sk_common.skc_v6_rcv_saddr
    387#define sk_cookie		__sk_common.skc_cookie
    388#define sk_incoming_cpu		__sk_common.skc_incoming_cpu
    389#define sk_flags		__sk_common.skc_flags
    390#define sk_rxhash		__sk_common.skc_rxhash
    391
    392	/* early demux fields */
    393	struct dst_entry __rcu	*sk_rx_dst;
    394	int			sk_rx_dst_ifindex;
    395	u32			sk_rx_dst_cookie;
    396
    397	socket_lock_t		sk_lock;
    398	atomic_t		sk_drops;
    399	int			sk_rcvlowat;
    400	struct sk_buff_head	sk_error_queue;
    401	struct sk_buff_head	sk_receive_queue;
    402	/*
    403	 * The backlog queue is special, it is always used with
    404	 * the per-socket spinlock held and requires low latency
    405	 * access. Therefore we special case it's implementation.
    406	 * Note : rmem_alloc is in this structure to fill a hole
    407	 * on 64bit arches, not because its logically part of
    408	 * backlog.
    409	 */
    410	struct {
    411		atomic_t	rmem_alloc;
    412		int		len;
    413		struct sk_buff	*head;
    414		struct sk_buff	*tail;
    415	} sk_backlog;
    416
    417#define sk_rmem_alloc sk_backlog.rmem_alloc
    418
    419	int			sk_forward_alloc;
    420	u32			sk_reserved_mem;
    421#ifdef CONFIG_NET_RX_BUSY_POLL
    422	unsigned int		sk_ll_usec;
    423	/* ===== mostly read cache line ===== */
    424	unsigned int		sk_napi_id;
    425#endif
    426	int			sk_rcvbuf;
    427
    428	struct sk_filter __rcu	*sk_filter;
    429	union {
    430		struct socket_wq __rcu	*sk_wq;
    431		/* private: */
    432		struct socket_wq	*sk_wq_raw;
    433		/* public: */
    434	};
    435#ifdef CONFIG_XFRM
    436	struct xfrm_policy __rcu *sk_policy[2];
    437#endif
    438
    439	struct dst_entry __rcu	*sk_dst_cache;
    440	atomic_t		sk_omem_alloc;
    441	int			sk_sndbuf;
    442
    443	/* ===== cache line for TX ===== */
    444	int			sk_wmem_queued;
    445	refcount_t		sk_wmem_alloc;
    446	unsigned long		sk_tsq_flags;
    447	union {
    448		struct sk_buff	*sk_send_head;
    449		struct rb_root	tcp_rtx_queue;
    450	};
    451	struct sk_buff_head	sk_write_queue;
    452	__s32			sk_peek_off;
    453	int			sk_write_pending;
    454	__u32			sk_dst_pending_confirm;
    455	u32			sk_pacing_status; /* see enum sk_pacing */
    456	long			sk_sndtimeo;
    457	struct timer_list	sk_timer;
    458	__u32			sk_priority;
    459	__u32			sk_mark;
    460	unsigned long		sk_pacing_rate; /* bytes per second */
    461	unsigned long		sk_max_pacing_rate;
    462	struct page_frag	sk_frag;
    463	netdev_features_t	sk_route_caps;
    464	int			sk_gso_type;
    465	unsigned int		sk_gso_max_size;
    466	gfp_t			sk_allocation;
    467	__u32			sk_txhash;
    468
    469	/*
    470	 * Because of non atomicity rules, all
    471	 * changes are protected by socket lock.
    472	 */
    473	u8			sk_gso_disabled : 1,
    474				sk_kern_sock : 1,
    475				sk_no_check_tx : 1,
    476				sk_no_check_rx : 1,
    477				sk_userlocks : 4;
    478	u8			sk_pacing_shift;
    479	u16			sk_type;
    480	u16			sk_protocol;
    481	u16			sk_gso_max_segs;
    482	unsigned long	        sk_lingertime;
    483	struct proto		*sk_prot_creator;
    484	rwlock_t		sk_callback_lock;
    485	int			sk_err,
    486				sk_err_soft;
    487	u32			sk_ack_backlog;
    488	u32			sk_max_ack_backlog;
    489	kuid_t			sk_uid;
    490	u8			sk_txrehash;
    491#ifdef CONFIG_NET_RX_BUSY_POLL
    492	u8			sk_prefer_busy_poll;
    493	u16			sk_busy_poll_budget;
    494#endif
    495	spinlock_t		sk_peer_lock;
    496	int			sk_bind_phc;
    497	struct pid		*sk_peer_pid;
    498	const struct cred	*sk_peer_cred;
    499
    500	long			sk_rcvtimeo;
    501	ktime_t			sk_stamp;
    502#if BITS_PER_LONG==32
    503	seqlock_t		sk_stamp_seq;
    504#endif
    505	u16			sk_tsflags;
    506	u8			sk_shutdown;
    507	atomic_t		sk_tskey;
    508	atomic_t		sk_zckey;
    509
    510	u8			sk_clockid;
    511	u8			sk_txtime_deadline_mode : 1,
    512				sk_txtime_report_errors : 1,
    513				sk_txtime_unused : 6;
    514
    515	struct socket		*sk_socket;
    516	void			*sk_user_data;
    517#ifdef CONFIG_SECURITY
    518	void			*sk_security;
    519#endif
    520	struct sock_cgroup_data	sk_cgrp_data;
    521	struct mem_cgroup	*sk_memcg;
    522	void			(*sk_state_change)(struct sock *sk);
    523	void			(*sk_data_ready)(struct sock *sk);
    524	void			(*sk_write_space)(struct sock *sk);
    525	void			(*sk_error_report)(struct sock *sk);
    526	int			(*sk_backlog_rcv)(struct sock *sk,
    527						  struct sk_buff *skb);
    528#ifdef CONFIG_SOCK_VALIDATE_XMIT
    529	struct sk_buff*		(*sk_validate_xmit_skb)(struct sock *sk,
    530							struct net_device *dev,
    531							struct sk_buff *skb);
    532#endif
    533	void                    (*sk_destruct)(struct sock *sk);
    534	struct sock_reuseport __rcu	*sk_reuseport_cb;
    535#ifdef CONFIG_BPF_SYSCALL
    536	struct bpf_local_storage __rcu	*sk_bpf_storage;
    537#endif
    538	struct rcu_head		sk_rcu;
    539	netns_tracker		ns_tracker;
    540};
    541
    542enum sk_pacing {
    543	SK_PACING_NONE		= 0,
    544	SK_PACING_NEEDED	= 1,
    545	SK_PACING_FQ		= 2,
    546};
    547
    548/* Pointer stored in sk_user_data might not be suitable for copying
    549 * when cloning the socket. For instance, it can point to a reference
    550 * counted object. sk_user_data bottom bit is set if pointer must not
    551 * be copied.
    552 */
    553#define SK_USER_DATA_NOCOPY	1UL
    554#define SK_USER_DATA_BPF	2UL	/* Managed by BPF */
    555#define SK_USER_DATA_PTRMASK	~(SK_USER_DATA_NOCOPY | SK_USER_DATA_BPF)
    556
    557/**
    558 * sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
    559 * @sk: socket
    560 */
    561static inline bool sk_user_data_is_nocopy(const struct sock *sk)
    562{
    563	return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
    564}
    565
    566#define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
    567
    568#define rcu_dereference_sk_user_data(sk)				\
    569({									\
    570	void *__tmp = rcu_dereference(__sk_user_data((sk)));		\
    571	(void *)((uintptr_t)__tmp & SK_USER_DATA_PTRMASK);		\
    572})
    573#define rcu_assign_sk_user_data(sk, ptr)				\
    574({									\
    575	uintptr_t __tmp = (uintptr_t)(ptr);				\
    576	WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK);			\
    577	rcu_assign_pointer(__sk_user_data((sk)), __tmp);		\
    578})
    579#define rcu_assign_sk_user_data_nocopy(sk, ptr)				\
    580({									\
    581	uintptr_t __tmp = (uintptr_t)(ptr);				\
    582	WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK);			\
    583	rcu_assign_pointer(__sk_user_data((sk)),			\
    584			   __tmp | SK_USER_DATA_NOCOPY);		\
    585})
    586
    587static inline
    588struct net *sock_net(const struct sock *sk)
    589{
    590	return read_pnet(&sk->sk_net);
    591}
    592
    593static inline
    594void sock_net_set(struct sock *sk, struct net *net)
    595{
    596	write_pnet(&sk->sk_net, net);
    597}
    598
    599/*
    600 * SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
    601 * or not whether his port will be reused by someone else. SK_FORCE_REUSE
    602 * on a socket means that the socket will reuse everybody else's port
    603 * without looking at the other's sk_reuse value.
    604 */
    605
    606#define SK_NO_REUSE	0
    607#define SK_CAN_REUSE	1
    608#define SK_FORCE_REUSE	2
    609
    610int sk_set_peek_off(struct sock *sk, int val);
    611
    612static inline int sk_peek_offset(struct sock *sk, int flags)
    613{
    614	if (unlikely(flags & MSG_PEEK)) {
    615		return READ_ONCE(sk->sk_peek_off);
    616	}
    617
    618	return 0;
    619}
    620
    621static inline void sk_peek_offset_bwd(struct sock *sk, int val)
    622{
    623	s32 off = READ_ONCE(sk->sk_peek_off);
    624
    625	if (unlikely(off >= 0)) {
    626		off = max_t(s32, off - val, 0);
    627		WRITE_ONCE(sk->sk_peek_off, off);
    628	}
    629}
    630
    631static inline void sk_peek_offset_fwd(struct sock *sk, int val)
    632{
    633	sk_peek_offset_bwd(sk, -val);
    634}
    635
    636/*
    637 * Hashed lists helper routines
    638 */
    639static inline struct sock *sk_entry(const struct hlist_node *node)
    640{
    641	return hlist_entry(node, struct sock, sk_node);
    642}
    643
    644static inline struct sock *__sk_head(const struct hlist_head *head)
    645{
    646	return hlist_entry(head->first, struct sock, sk_node);
    647}
    648
    649static inline struct sock *sk_head(const struct hlist_head *head)
    650{
    651	return hlist_empty(head) ? NULL : __sk_head(head);
    652}
    653
    654static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
    655{
    656	return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
    657}
    658
    659static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
    660{
    661	return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
    662}
    663
    664static inline struct sock *sk_next(const struct sock *sk)
    665{
    666	return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
    667}
    668
    669static inline struct sock *sk_nulls_next(const struct sock *sk)
    670{
    671	return (!is_a_nulls(sk->sk_nulls_node.next)) ?
    672		hlist_nulls_entry(sk->sk_nulls_node.next,
    673				  struct sock, sk_nulls_node) :
    674		NULL;
    675}
    676
    677static inline bool sk_unhashed(const struct sock *sk)
    678{
    679	return hlist_unhashed(&sk->sk_node);
    680}
    681
    682static inline bool sk_hashed(const struct sock *sk)
    683{
    684	return !sk_unhashed(sk);
    685}
    686
    687static inline void sk_node_init(struct hlist_node *node)
    688{
    689	node->pprev = NULL;
    690}
    691
    692static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
    693{
    694	node->pprev = NULL;
    695}
    696
    697static inline void __sk_del_node(struct sock *sk)
    698{
    699	__hlist_del(&sk->sk_node);
    700}
    701
    702/* NB: equivalent to hlist_del_init_rcu */
    703static inline bool __sk_del_node_init(struct sock *sk)
    704{
    705	if (sk_hashed(sk)) {
    706		__sk_del_node(sk);
    707		sk_node_init(&sk->sk_node);
    708		return true;
    709	}
    710	return false;
    711}
    712
    713/* Grab socket reference count. This operation is valid only
    714   when sk is ALREADY grabbed f.e. it is found in hash table
    715   or a list and the lookup is made under lock preventing hash table
    716   modifications.
    717 */
    718
    719static __always_inline void sock_hold(struct sock *sk)
    720{
    721	refcount_inc(&sk->sk_refcnt);
    722}
    723
    724/* Ungrab socket in the context, which assumes that socket refcnt
    725   cannot hit zero, f.e. it is true in context of any socketcall.
    726 */
    727static __always_inline void __sock_put(struct sock *sk)
    728{
    729	refcount_dec(&sk->sk_refcnt);
    730}
    731
    732static inline bool sk_del_node_init(struct sock *sk)
    733{
    734	bool rc = __sk_del_node_init(sk);
    735
    736	if (rc) {
    737		/* paranoid for a while -acme */
    738		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
    739		__sock_put(sk);
    740	}
    741	return rc;
    742}
    743#define sk_del_node_init_rcu(sk)	sk_del_node_init(sk)
    744
    745static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
    746{
    747	if (sk_hashed(sk)) {
    748		hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
    749		return true;
    750	}
    751	return false;
    752}
    753
    754static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
    755{
    756	bool rc = __sk_nulls_del_node_init_rcu(sk);
    757
    758	if (rc) {
    759		/* paranoid for a while -acme */
    760		WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
    761		__sock_put(sk);
    762	}
    763	return rc;
    764}
    765
    766static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
    767{
    768	hlist_add_head(&sk->sk_node, list);
    769}
    770
    771static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
    772{
    773	sock_hold(sk);
    774	__sk_add_node(sk, list);
    775}
    776
    777static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
    778{
    779	sock_hold(sk);
    780	if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
    781	    sk->sk_family == AF_INET6)
    782		hlist_add_tail_rcu(&sk->sk_node, list);
    783	else
    784		hlist_add_head_rcu(&sk->sk_node, list);
    785}
    786
    787static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
    788{
    789	sock_hold(sk);
    790	hlist_add_tail_rcu(&sk->sk_node, list);
    791}
    792
    793static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
    794{
    795	hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
    796}
    797
    798static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
    799{
    800	hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
    801}
    802
    803static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
    804{
    805	sock_hold(sk);
    806	__sk_nulls_add_node_rcu(sk, list);
    807}
    808
    809static inline void __sk_del_bind_node(struct sock *sk)
    810{
    811	__hlist_del(&sk->sk_bind_node);
    812}
    813
    814static inline void sk_add_bind_node(struct sock *sk,
    815					struct hlist_head *list)
    816{
    817	hlist_add_head(&sk->sk_bind_node, list);
    818}
    819
    820#define sk_for_each(__sk, list) \
    821	hlist_for_each_entry(__sk, list, sk_node)
    822#define sk_for_each_rcu(__sk, list) \
    823	hlist_for_each_entry_rcu(__sk, list, sk_node)
    824#define sk_nulls_for_each(__sk, node, list) \
    825	hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
    826#define sk_nulls_for_each_rcu(__sk, node, list) \
    827	hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
    828#define sk_for_each_from(__sk) \
    829	hlist_for_each_entry_from(__sk, sk_node)
    830#define sk_nulls_for_each_from(__sk, node) \
    831	if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
    832		hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
    833#define sk_for_each_safe(__sk, tmp, list) \
    834	hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
    835#define sk_for_each_bound(__sk, list) \
    836	hlist_for_each_entry(__sk, list, sk_bind_node)
    837
    838/**
    839 * sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
    840 * @tpos:	the type * to use as a loop cursor.
    841 * @pos:	the &struct hlist_node to use as a loop cursor.
    842 * @head:	the head for your list.
    843 * @offset:	offset of hlist_node within the struct.
    844 *
    845 */
    846#define sk_for_each_entry_offset_rcu(tpos, pos, head, offset)		       \
    847	for (pos = rcu_dereference(hlist_first_rcu(head));		       \
    848	     pos != NULL &&						       \
    849		({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;});       \
    850	     pos = rcu_dereference(hlist_next_rcu(pos)))
    851
    852static inline struct user_namespace *sk_user_ns(struct sock *sk)
    853{
    854	/* Careful only use this in a context where these parameters
    855	 * can not change and must all be valid, such as recvmsg from
    856	 * userspace.
    857	 */
    858	return sk->sk_socket->file->f_cred->user_ns;
    859}
    860
    861/* Sock flags */
    862enum sock_flags {
    863	SOCK_DEAD,
    864	SOCK_DONE,
    865	SOCK_URGINLINE,
    866	SOCK_KEEPOPEN,
    867	SOCK_LINGER,
    868	SOCK_DESTROY,
    869	SOCK_BROADCAST,
    870	SOCK_TIMESTAMP,
    871	SOCK_ZAPPED,
    872	SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
    873	SOCK_DBG, /* %SO_DEBUG setting */
    874	SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
    875	SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
    876	SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
    877	SOCK_MEMALLOC, /* VM depends on this socket for swapping */
    878	SOCK_TIMESTAMPING_RX_SOFTWARE,  /* %SOF_TIMESTAMPING_RX_SOFTWARE */
    879	SOCK_FASYNC, /* fasync() active */
    880	SOCK_RXQ_OVFL,
    881	SOCK_ZEROCOPY, /* buffers from userspace */
    882	SOCK_WIFI_STATUS, /* push wifi status to userspace */
    883	SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
    884		     * Will use last 4 bytes of packet sent from
    885		     * user-space instead.
    886		     */
    887	SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
    888	SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
    889	SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
    890	SOCK_TXTIME,
    891	SOCK_XDP, /* XDP is attached */
    892	SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
    893	SOCK_RCVMARK, /* Receive SO_MARK  ancillary data with packet */
    894};
    895
    896#define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
    897
    898static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
    899{
    900	nsk->sk_flags = osk->sk_flags;
    901}
    902
    903static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
    904{
    905	__set_bit(flag, &sk->sk_flags);
    906}
    907
    908static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
    909{
    910	__clear_bit(flag, &sk->sk_flags);
    911}
    912
    913static inline void sock_valbool_flag(struct sock *sk, enum sock_flags bit,
    914				     int valbool)
    915{
    916	if (valbool)
    917		sock_set_flag(sk, bit);
    918	else
    919		sock_reset_flag(sk, bit);
    920}
    921
    922static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
    923{
    924	return test_bit(flag, &sk->sk_flags);
    925}
    926
    927#ifdef CONFIG_NET
    928DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
    929static inline int sk_memalloc_socks(void)
    930{
    931	return static_branch_unlikely(&memalloc_socks_key);
    932}
    933
    934void __receive_sock(struct file *file);
    935#else
    936
    937static inline int sk_memalloc_socks(void)
    938{
    939	return 0;
    940}
    941
    942static inline void __receive_sock(struct file *file)
    943{ }
    944#endif
    945
    946static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
    947{
    948	return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
    949}
    950
    951static inline void sk_acceptq_removed(struct sock *sk)
    952{
    953	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
    954}
    955
    956static inline void sk_acceptq_added(struct sock *sk)
    957{
    958	WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
    959}
    960
    961/* Note: If you think the test should be:
    962 *	return READ_ONCE(sk->sk_ack_backlog) >= READ_ONCE(sk->sk_max_ack_backlog);
    963 * Then please take a look at commit 64a146513f8f ("[NET]: Revert incorrect accept queue backlog changes.")
    964 */
    965static inline bool sk_acceptq_is_full(const struct sock *sk)
    966{
    967	return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
    968}
    969
    970/*
    971 * Compute minimal free write space needed to queue new packets.
    972 */
    973static inline int sk_stream_min_wspace(const struct sock *sk)
    974{
    975	return READ_ONCE(sk->sk_wmem_queued) >> 1;
    976}
    977
    978static inline int sk_stream_wspace(const struct sock *sk)
    979{
    980	return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
    981}
    982
    983static inline void sk_wmem_queued_add(struct sock *sk, int val)
    984{
    985	WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
    986}
    987
    988void sk_stream_write_space(struct sock *sk);
    989
    990/* OOB backlog add */
    991static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
    992{
    993	/* dont let skb dst not refcounted, we are going to leave rcu lock */
    994	skb_dst_force(skb);
    995
    996	if (!sk->sk_backlog.tail)
    997		WRITE_ONCE(sk->sk_backlog.head, skb);
    998	else
    999		sk->sk_backlog.tail->next = skb;
   1000
   1001	WRITE_ONCE(sk->sk_backlog.tail, skb);
   1002	skb->next = NULL;
   1003}
   1004
   1005/*
   1006 * Take into account size of receive queue and backlog queue
   1007 * Do not take into account this skb truesize,
   1008 * to allow even a single big packet to come.
   1009 */
   1010static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
   1011{
   1012	unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
   1013
   1014	return qsize > limit;
   1015}
   1016
   1017/* The per-socket spinlock must be held here. */
   1018static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
   1019					      unsigned int limit)
   1020{
   1021	if (sk_rcvqueues_full(sk, limit))
   1022		return -ENOBUFS;
   1023
   1024	/*
   1025	 * If the skb was allocated from pfmemalloc reserves, only
   1026	 * allow SOCK_MEMALLOC sockets to use it as this socket is
   1027	 * helping free memory
   1028	 */
   1029	if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
   1030		return -ENOMEM;
   1031
   1032	__sk_add_backlog(sk, skb);
   1033	sk->sk_backlog.len += skb->truesize;
   1034	return 0;
   1035}
   1036
   1037int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
   1038
   1039INDIRECT_CALLABLE_DECLARE(int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb));
   1040INDIRECT_CALLABLE_DECLARE(int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb));
   1041
   1042static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
   1043{
   1044	if (sk_memalloc_socks() && skb_pfmemalloc(skb))
   1045		return __sk_backlog_rcv(sk, skb);
   1046
   1047	return INDIRECT_CALL_INET(sk->sk_backlog_rcv,
   1048				  tcp_v6_do_rcv,
   1049				  tcp_v4_do_rcv,
   1050				  sk, skb);
   1051}
   1052
   1053static inline void sk_incoming_cpu_update(struct sock *sk)
   1054{
   1055	int cpu = raw_smp_processor_id();
   1056
   1057	if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu))
   1058		WRITE_ONCE(sk->sk_incoming_cpu, cpu);
   1059}
   1060
   1061static inline void sock_rps_record_flow_hash(__u32 hash)
   1062{
   1063#ifdef CONFIG_RPS
   1064	struct rps_sock_flow_table *sock_flow_table;
   1065
   1066	rcu_read_lock();
   1067	sock_flow_table = rcu_dereference(rps_sock_flow_table);
   1068	rps_record_sock_flow(sock_flow_table, hash);
   1069	rcu_read_unlock();
   1070#endif
   1071}
   1072
   1073static inline void sock_rps_record_flow(const struct sock *sk)
   1074{
   1075#ifdef CONFIG_RPS
   1076	if (static_branch_unlikely(&rfs_needed)) {
   1077		/* Reading sk->sk_rxhash might incur an expensive cache line
   1078		 * miss.
   1079		 *
   1080		 * TCP_ESTABLISHED does cover almost all states where RFS
   1081		 * might be useful, and is cheaper [1] than testing :
   1082		 *	IPv4: inet_sk(sk)->inet_daddr
   1083		 * 	IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
   1084		 * OR	an additional socket flag
   1085		 * [1] : sk_state and sk_prot are in the same cache line.
   1086		 */
   1087		if (sk->sk_state == TCP_ESTABLISHED)
   1088			sock_rps_record_flow_hash(sk->sk_rxhash);
   1089	}
   1090#endif
   1091}
   1092
   1093static inline void sock_rps_save_rxhash(struct sock *sk,
   1094					const struct sk_buff *skb)
   1095{
   1096#ifdef CONFIG_RPS
   1097	if (unlikely(sk->sk_rxhash != skb->hash))
   1098		sk->sk_rxhash = skb->hash;
   1099#endif
   1100}
   1101
   1102static inline void sock_rps_reset_rxhash(struct sock *sk)
   1103{
   1104#ifdef CONFIG_RPS
   1105	sk->sk_rxhash = 0;
   1106#endif
   1107}
   1108
   1109#define sk_wait_event(__sk, __timeo, __condition, __wait)		\
   1110	({	int __rc;						\
   1111		release_sock(__sk);					\
   1112		__rc = __condition;					\
   1113		if (!__rc) {						\
   1114			*(__timeo) = wait_woken(__wait,			\
   1115						TASK_INTERRUPTIBLE,	\
   1116						*(__timeo));		\
   1117		}							\
   1118		sched_annotate_sleep();					\
   1119		lock_sock(__sk);					\
   1120		__rc = __condition;					\
   1121		__rc;							\
   1122	})
   1123
   1124int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
   1125int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
   1126void sk_stream_wait_close(struct sock *sk, long timeo_p);
   1127int sk_stream_error(struct sock *sk, int flags, int err);
   1128void sk_stream_kill_queues(struct sock *sk);
   1129void sk_set_memalloc(struct sock *sk);
   1130void sk_clear_memalloc(struct sock *sk);
   1131
   1132void __sk_flush_backlog(struct sock *sk);
   1133
   1134static inline bool sk_flush_backlog(struct sock *sk)
   1135{
   1136	if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
   1137		__sk_flush_backlog(sk);
   1138		return true;
   1139	}
   1140	return false;
   1141}
   1142
   1143int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
   1144
   1145struct request_sock_ops;
   1146struct timewait_sock_ops;
   1147struct inet_hashinfo;
   1148struct raw_hashinfo;
   1149struct smc_hashinfo;
   1150struct module;
   1151struct sk_psock;
   1152
   1153/*
   1154 * caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
   1155 * un-modified. Special care is taken when initializing object to zero.
   1156 */
   1157static inline void sk_prot_clear_nulls(struct sock *sk, int size)
   1158{
   1159	if (offsetof(struct sock, sk_node.next) != 0)
   1160		memset(sk, 0, offsetof(struct sock, sk_node.next));
   1161	memset(&sk->sk_node.pprev, 0,
   1162	       size - offsetof(struct sock, sk_node.pprev));
   1163}
   1164
   1165/* Networking protocol blocks we attach to sockets.
   1166 * socket layer -> transport layer interface
   1167 */
   1168struct proto {
   1169	void			(*close)(struct sock *sk,
   1170					long timeout);
   1171	int			(*pre_connect)(struct sock *sk,
   1172					struct sockaddr *uaddr,
   1173					int addr_len);
   1174	int			(*connect)(struct sock *sk,
   1175					struct sockaddr *uaddr,
   1176					int addr_len);
   1177	int			(*disconnect)(struct sock *sk, int flags);
   1178
   1179	struct sock *		(*accept)(struct sock *sk, int flags, int *err,
   1180					  bool kern);
   1181
   1182	int			(*ioctl)(struct sock *sk, int cmd,
   1183					 unsigned long arg);
   1184	int			(*init)(struct sock *sk);
   1185	void			(*destroy)(struct sock *sk);
   1186	void			(*shutdown)(struct sock *sk, int how);
   1187	int			(*setsockopt)(struct sock *sk, int level,
   1188					int optname, sockptr_t optval,
   1189					unsigned int optlen);
   1190	int			(*getsockopt)(struct sock *sk, int level,
   1191					int optname, char __user *optval,
   1192					int __user *option);
   1193	void			(*keepalive)(struct sock *sk, int valbool);
   1194#ifdef CONFIG_COMPAT
   1195	int			(*compat_ioctl)(struct sock *sk,
   1196					unsigned int cmd, unsigned long arg);
   1197#endif
   1198	int			(*sendmsg)(struct sock *sk, struct msghdr *msg,
   1199					   size_t len);
   1200	int			(*recvmsg)(struct sock *sk, struct msghdr *msg,
   1201					   size_t len, int flags, int *addr_len);
   1202	int			(*sendpage)(struct sock *sk, struct page *page,
   1203					int offset, size_t size, int flags);
   1204	int			(*bind)(struct sock *sk,
   1205					struct sockaddr *addr, int addr_len);
   1206	int			(*bind_add)(struct sock *sk,
   1207					struct sockaddr *addr, int addr_len);
   1208
   1209	int			(*backlog_rcv) (struct sock *sk,
   1210						struct sk_buff *skb);
   1211	bool			(*bpf_bypass_getsockopt)(int level,
   1212							 int optname);
   1213
   1214	void		(*release_cb)(struct sock *sk);
   1215
   1216	/* Keeping track of sk's, looking them up, and port selection methods. */
   1217	int			(*hash)(struct sock *sk);
   1218	void			(*unhash)(struct sock *sk);
   1219	void			(*rehash)(struct sock *sk);
   1220	int			(*get_port)(struct sock *sk, unsigned short snum);
   1221	void			(*put_port)(struct sock *sk);
   1222#ifdef CONFIG_BPF_SYSCALL
   1223	int			(*psock_update_sk_prot)(struct sock *sk,
   1224							struct sk_psock *psock,
   1225							bool restore);
   1226#endif
   1227
   1228	/* Keeping track of sockets in use */
   1229#ifdef CONFIG_PROC_FS
   1230	unsigned int		inuse_idx;
   1231#endif
   1232
   1233#if IS_ENABLED(CONFIG_MPTCP)
   1234	int			(*forward_alloc_get)(const struct sock *sk);
   1235#endif
   1236
   1237	bool			(*stream_memory_free)(const struct sock *sk, int wake);
   1238	bool			(*sock_is_readable)(struct sock *sk);
   1239	/* Memory pressure */
   1240	void			(*enter_memory_pressure)(struct sock *sk);
   1241	void			(*leave_memory_pressure)(struct sock *sk);
   1242	atomic_long_t		*memory_allocated;	/* Current allocated memory. */
   1243	struct percpu_counter	*sockets_allocated;	/* Current number of sockets. */
   1244
   1245	/*
   1246	 * Pressure flag: try to collapse.
   1247	 * Technical note: it is used by multiple contexts non atomically.
   1248	 * All the __sk_mem_schedule() is of this nature: accounting
   1249	 * is strict, actions are advisory and have some latency.
   1250	 */
   1251	unsigned long		*memory_pressure;
   1252	long			*sysctl_mem;
   1253
   1254	int			*sysctl_wmem;
   1255	int			*sysctl_rmem;
   1256	u32			sysctl_wmem_offset;
   1257	u32			sysctl_rmem_offset;
   1258
   1259	int			max_header;
   1260	bool			no_autobind;
   1261
   1262	struct kmem_cache	*slab;
   1263	unsigned int		obj_size;
   1264	slab_flags_t		slab_flags;
   1265	unsigned int		useroffset;	/* Usercopy region offset */
   1266	unsigned int		usersize;	/* Usercopy region size */
   1267
   1268	unsigned int __percpu	*orphan_count;
   1269
   1270	struct request_sock_ops	*rsk_prot;
   1271	struct timewait_sock_ops *twsk_prot;
   1272
   1273	union {
   1274		struct inet_hashinfo	*hashinfo;
   1275		struct udp_table	*udp_table;
   1276		struct raw_hashinfo	*raw_hash;
   1277		struct smc_hashinfo	*smc_hash;
   1278	} h;
   1279
   1280	struct module		*owner;
   1281
   1282	char			name[32];
   1283
   1284	struct list_head	node;
   1285#ifdef SOCK_REFCNT_DEBUG
   1286	atomic_t		socks;
   1287#endif
   1288	int			(*diag_destroy)(struct sock *sk, int err);
   1289} __randomize_layout;
   1290
   1291int proto_register(struct proto *prot, int alloc_slab);
   1292void proto_unregister(struct proto *prot);
   1293int sock_load_diag_module(int family, int protocol);
   1294
   1295#ifdef SOCK_REFCNT_DEBUG
   1296static inline void sk_refcnt_debug_inc(struct sock *sk)
   1297{
   1298	atomic_inc(&sk->sk_prot->socks);
   1299}
   1300
   1301static inline void sk_refcnt_debug_dec(struct sock *sk)
   1302{
   1303	atomic_dec(&sk->sk_prot->socks);
   1304	printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
   1305	       sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
   1306}
   1307
   1308static inline void sk_refcnt_debug_release(const struct sock *sk)
   1309{
   1310	if (refcount_read(&sk->sk_refcnt) != 1)
   1311		printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
   1312		       sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
   1313}
   1314#else /* SOCK_REFCNT_DEBUG */
   1315#define sk_refcnt_debug_inc(sk) do { } while (0)
   1316#define sk_refcnt_debug_dec(sk) do { } while (0)
   1317#define sk_refcnt_debug_release(sk) do { } while (0)
   1318#endif /* SOCK_REFCNT_DEBUG */
   1319
   1320INDIRECT_CALLABLE_DECLARE(bool tcp_stream_memory_free(const struct sock *sk, int wake));
   1321
   1322static inline int sk_forward_alloc_get(const struct sock *sk)
   1323{
   1324#if IS_ENABLED(CONFIG_MPTCP)
   1325	if (sk->sk_prot->forward_alloc_get)
   1326		return sk->sk_prot->forward_alloc_get(sk);
   1327#endif
   1328	return sk->sk_forward_alloc;
   1329}
   1330
   1331static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
   1332{
   1333	if (READ_ONCE(sk->sk_wmem_queued) >= READ_ONCE(sk->sk_sndbuf))
   1334		return false;
   1335
   1336	return sk->sk_prot->stream_memory_free ?
   1337		INDIRECT_CALL_INET_1(sk->sk_prot->stream_memory_free,
   1338				     tcp_stream_memory_free, sk, wake) : true;
   1339}
   1340
   1341static inline bool sk_stream_memory_free(const struct sock *sk)
   1342{
   1343	return __sk_stream_memory_free(sk, 0);
   1344}
   1345
   1346static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
   1347{
   1348	return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
   1349	       __sk_stream_memory_free(sk, wake);
   1350}
   1351
   1352static inline bool sk_stream_is_writeable(const struct sock *sk)
   1353{
   1354	return __sk_stream_is_writeable(sk, 0);
   1355}
   1356
   1357static inline int sk_under_cgroup_hierarchy(struct sock *sk,
   1358					    struct cgroup *ancestor)
   1359{
   1360#ifdef CONFIG_SOCK_CGROUP_DATA
   1361	return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
   1362				    ancestor);
   1363#else
   1364	return -ENOTSUPP;
   1365#endif
   1366}
   1367
   1368static inline bool sk_has_memory_pressure(const struct sock *sk)
   1369{
   1370	return sk->sk_prot->memory_pressure != NULL;
   1371}
   1372
   1373static inline bool sk_under_memory_pressure(const struct sock *sk)
   1374{
   1375	if (!sk->sk_prot->memory_pressure)
   1376		return false;
   1377
   1378	if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
   1379	    mem_cgroup_under_socket_pressure(sk->sk_memcg))
   1380		return true;
   1381
   1382	return !!*sk->sk_prot->memory_pressure;
   1383}
   1384
   1385static inline long
   1386sk_memory_allocated(const struct sock *sk)
   1387{
   1388	return atomic_long_read(sk->sk_prot->memory_allocated);
   1389}
   1390
   1391static inline long
   1392sk_memory_allocated_add(struct sock *sk, int amt)
   1393{
   1394	return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
   1395}
   1396
   1397static inline void
   1398sk_memory_allocated_sub(struct sock *sk, int amt)
   1399{
   1400	atomic_long_sub(amt, sk->sk_prot->memory_allocated);
   1401}
   1402
   1403#define SK_ALLOC_PERCPU_COUNTER_BATCH 16
   1404
   1405static inline void sk_sockets_allocated_dec(struct sock *sk)
   1406{
   1407	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, -1,
   1408				 SK_ALLOC_PERCPU_COUNTER_BATCH);
   1409}
   1410
   1411static inline void sk_sockets_allocated_inc(struct sock *sk)
   1412{
   1413	percpu_counter_add_batch(sk->sk_prot->sockets_allocated, 1,
   1414				 SK_ALLOC_PERCPU_COUNTER_BATCH);
   1415}
   1416
   1417static inline u64
   1418sk_sockets_allocated_read_positive(struct sock *sk)
   1419{
   1420	return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
   1421}
   1422
   1423static inline int
   1424proto_sockets_allocated_sum_positive(struct proto *prot)
   1425{
   1426	return percpu_counter_sum_positive(prot->sockets_allocated);
   1427}
   1428
   1429static inline long
   1430proto_memory_allocated(struct proto *prot)
   1431{
   1432	return atomic_long_read(prot->memory_allocated);
   1433}
   1434
   1435static inline bool
   1436proto_memory_pressure(struct proto *prot)
   1437{
   1438	if (!prot->memory_pressure)
   1439		return false;
   1440	return !!*prot->memory_pressure;
   1441}
   1442
   1443
   1444#ifdef CONFIG_PROC_FS
   1445#define PROTO_INUSE_NR	64	/* should be enough for the first time */
   1446struct prot_inuse {
   1447	int all;
   1448	int val[PROTO_INUSE_NR];
   1449};
   1450
   1451static inline void sock_prot_inuse_add(const struct net *net,
   1452				       const struct proto *prot, int val)
   1453{
   1454	this_cpu_add(net->core.prot_inuse->val[prot->inuse_idx], val);
   1455}
   1456
   1457static inline void sock_inuse_add(const struct net *net, int val)
   1458{
   1459	this_cpu_add(net->core.prot_inuse->all, val);
   1460}
   1461
   1462int sock_prot_inuse_get(struct net *net, struct proto *proto);
   1463int sock_inuse_get(struct net *net);
   1464#else
   1465static inline void sock_prot_inuse_add(const struct net *net,
   1466				       const struct proto *prot, int val)
   1467{
   1468}
   1469
   1470static inline void sock_inuse_add(const struct net *net, int val)
   1471{
   1472}
   1473#endif
   1474
   1475
   1476/* With per-bucket locks this operation is not-atomic, so that
   1477 * this version is not worse.
   1478 */
   1479static inline int __sk_prot_rehash(struct sock *sk)
   1480{
   1481	sk->sk_prot->unhash(sk);
   1482	return sk->sk_prot->hash(sk);
   1483}
   1484
   1485/* About 10 seconds */
   1486#define SOCK_DESTROY_TIME (10*HZ)
   1487
   1488/* Sockets 0-1023 can't be bound to unless you are superuser */
   1489#define PROT_SOCK	1024
   1490
   1491#define SHUTDOWN_MASK	3
   1492#define RCV_SHUTDOWN	1
   1493#define SEND_SHUTDOWN	2
   1494
   1495#define SOCK_BINDADDR_LOCK	4
   1496#define SOCK_BINDPORT_LOCK	8
   1497
   1498struct socket_alloc {
   1499	struct socket socket;
   1500	struct inode vfs_inode;
   1501};
   1502
   1503static inline struct socket *SOCKET_I(struct inode *inode)
   1504{
   1505	return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
   1506}
   1507
   1508static inline struct inode *SOCK_INODE(struct socket *socket)
   1509{
   1510	return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
   1511}
   1512
   1513/*
   1514 * Functions for memory accounting
   1515 */
   1516int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
   1517int __sk_mem_schedule(struct sock *sk, int size, int kind);
   1518void __sk_mem_reduce_allocated(struct sock *sk, int amount);
   1519void __sk_mem_reclaim(struct sock *sk, int amount);
   1520
   1521/* We used to have PAGE_SIZE here, but systems with 64KB pages
   1522 * do not necessarily have 16x time more memory than 4KB ones.
   1523 */
   1524#define SK_MEM_QUANTUM 4096
   1525#define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
   1526#define SK_MEM_SEND	0
   1527#define SK_MEM_RECV	1
   1528
   1529/* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
   1530static inline long sk_prot_mem_limits(const struct sock *sk, int index)
   1531{
   1532	long val = sk->sk_prot->sysctl_mem[index];
   1533
   1534#if PAGE_SIZE > SK_MEM_QUANTUM
   1535	val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;
   1536#elif PAGE_SIZE < SK_MEM_QUANTUM
   1537	val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT;
   1538#endif
   1539	return val;
   1540}
   1541
   1542static inline int sk_mem_pages(int amt)
   1543{
   1544	return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
   1545}
   1546
   1547static inline bool sk_has_account(struct sock *sk)
   1548{
   1549	/* return true if protocol supports memory accounting */
   1550	return !!sk->sk_prot->memory_allocated;
   1551}
   1552
   1553static inline bool sk_wmem_schedule(struct sock *sk, int size)
   1554{
   1555	if (!sk_has_account(sk))
   1556		return true;
   1557	return size <= sk->sk_forward_alloc ||
   1558		__sk_mem_schedule(sk, size, SK_MEM_SEND);
   1559}
   1560
   1561static inline bool
   1562sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
   1563{
   1564	if (!sk_has_account(sk))
   1565		return true;
   1566	return size <= sk->sk_forward_alloc ||
   1567		__sk_mem_schedule(sk, size, SK_MEM_RECV) ||
   1568		skb_pfmemalloc(skb);
   1569}
   1570
   1571static inline int sk_unused_reserved_mem(const struct sock *sk)
   1572{
   1573	int unused_mem;
   1574
   1575	if (likely(!sk->sk_reserved_mem))
   1576		return 0;
   1577
   1578	unused_mem = sk->sk_reserved_mem - sk->sk_wmem_queued -
   1579			atomic_read(&sk->sk_rmem_alloc);
   1580
   1581	return unused_mem > 0 ? unused_mem : 0;
   1582}
   1583
   1584static inline void sk_mem_reclaim(struct sock *sk)
   1585{
   1586	int reclaimable;
   1587
   1588	if (!sk_has_account(sk))
   1589		return;
   1590
   1591	reclaimable = sk->sk_forward_alloc - sk_unused_reserved_mem(sk);
   1592
   1593	if (reclaimable >= SK_MEM_QUANTUM)
   1594		__sk_mem_reclaim(sk, reclaimable);
   1595}
   1596
   1597static inline void sk_mem_reclaim_final(struct sock *sk)
   1598{
   1599	sk->sk_reserved_mem = 0;
   1600	sk_mem_reclaim(sk);
   1601}
   1602
   1603static inline void sk_mem_reclaim_partial(struct sock *sk)
   1604{
   1605	int reclaimable;
   1606
   1607	if (!sk_has_account(sk))
   1608		return;
   1609
   1610	reclaimable = sk->sk_forward_alloc - sk_unused_reserved_mem(sk);
   1611
   1612	if (reclaimable > SK_MEM_QUANTUM)
   1613		__sk_mem_reclaim(sk, reclaimable - 1);
   1614}
   1615
   1616static inline void sk_mem_charge(struct sock *sk, int size)
   1617{
   1618	if (!sk_has_account(sk))
   1619		return;
   1620	sk->sk_forward_alloc -= size;
   1621}
   1622
   1623/* the following macros control memory reclaiming in sk_mem_uncharge()
   1624 */
   1625#define SK_RECLAIM_THRESHOLD	(1 << 21)
   1626#define SK_RECLAIM_CHUNK	(1 << 20)
   1627
   1628static inline void sk_mem_uncharge(struct sock *sk, int size)
   1629{
   1630	int reclaimable;
   1631
   1632	if (!sk_has_account(sk))
   1633		return;
   1634	sk->sk_forward_alloc += size;
   1635	reclaimable = sk->sk_forward_alloc - sk_unused_reserved_mem(sk);
   1636
   1637	/* Avoid a possible overflow.
   1638	 * TCP send queues can make this happen, if sk_mem_reclaim()
   1639	 * is not called and more than 2 GBytes are released at once.
   1640	 *
   1641	 * If we reach 2 MBytes, reclaim 1 MBytes right now, there is
   1642	 * no need to hold that much forward allocation anyway.
   1643	 */
   1644	if (unlikely(reclaimable >= SK_RECLAIM_THRESHOLD))
   1645		__sk_mem_reclaim(sk, SK_RECLAIM_CHUNK);
   1646}
   1647
   1648/*
   1649 * Macro so as to not evaluate some arguments when
   1650 * lockdep is not enabled.
   1651 *
   1652 * Mark both the sk_lock and the sk_lock.slock as a
   1653 * per-address-family lock class.
   1654 */
   1655#define sock_lock_init_class_and_name(sk, sname, skey, name, key)	\
   1656do {									\
   1657	sk->sk_lock.owned = 0;						\
   1658	init_waitqueue_head(&sk->sk_lock.wq);				\
   1659	spin_lock_init(&(sk)->sk_lock.slock);				\
   1660	debug_check_no_locks_freed((void *)&(sk)->sk_lock,		\
   1661			sizeof((sk)->sk_lock));				\
   1662	lockdep_set_class_and_name(&(sk)->sk_lock.slock,		\
   1663				(skey), (sname));				\
   1664	lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0);	\
   1665} while (0)
   1666
   1667static inline bool lockdep_sock_is_held(const struct sock *sk)
   1668{
   1669	return lockdep_is_held(&sk->sk_lock) ||
   1670	       lockdep_is_held(&sk->sk_lock.slock);
   1671}
   1672
   1673void lock_sock_nested(struct sock *sk, int subclass);
   1674
   1675static inline void lock_sock(struct sock *sk)
   1676{
   1677	lock_sock_nested(sk, 0);
   1678}
   1679
   1680void __lock_sock(struct sock *sk);
   1681void __release_sock(struct sock *sk);
   1682void release_sock(struct sock *sk);
   1683
   1684/* BH context may only use the following locking interface. */
   1685#define bh_lock_sock(__sk)	spin_lock(&((__sk)->sk_lock.slock))
   1686#define bh_lock_sock_nested(__sk) \
   1687				spin_lock_nested(&((__sk)->sk_lock.slock), \
   1688				SINGLE_DEPTH_NESTING)
   1689#define bh_unlock_sock(__sk)	spin_unlock(&((__sk)->sk_lock.slock))
   1690
   1691bool __lock_sock_fast(struct sock *sk) __acquires(&sk->sk_lock.slock);
   1692
   1693/**
   1694 * lock_sock_fast - fast version of lock_sock
   1695 * @sk: socket
   1696 *
   1697 * This version should be used for very small section, where process wont block
   1698 * return false if fast path is taken:
   1699 *
   1700 *   sk_lock.slock locked, owned = 0, BH disabled
   1701 *
   1702 * return true if slow path is taken:
   1703 *
   1704 *   sk_lock.slock unlocked, owned = 1, BH enabled
   1705 */
   1706static inline bool lock_sock_fast(struct sock *sk)
   1707{
   1708	/* The sk_lock has mutex_lock() semantics here. */
   1709	mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
   1710
   1711	return __lock_sock_fast(sk);
   1712}
   1713
   1714/* fast socket lock variant for caller already holding a [different] socket lock */
   1715static inline bool lock_sock_fast_nested(struct sock *sk)
   1716{
   1717	mutex_acquire(&sk->sk_lock.dep_map, SINGLE_DEPTH_NESTING, 0, _RET_IP_);
   1718
   1719	return __lock_sock_fast(sk);
   1720}
   1721
   1722/**
   1723 * unlock_sock_fast - complement of lock_sock_fast
   1724 * @sk: socket
   1725 * @slow: slow mode
   1726 *
   1727 * fast unlock socket for user context.
   1728 * If slow mode is on, we call regular release_sock()
   1729 */
   1730static inline void unlock_sock_fast(struct sock *sk, bool slow)
   1731	__releases(&sk->sk_lock.slock)
   1732{
   1733	if (slow) {
   1734		release_sock(sk);
   1735		__release(&sk->sk_lock.slock);
   1736	} else {
   1737		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
   1738		spin_unlock_bh(&sk->sk_lock.slock);
   1739	}
   1740}
   1741
   1742/* Used by processes to "lock" a socket state, so that
   1743 * interrupts and bottom half handlers won't change it
   1744 * from under us. It essentially blocks any incoming
   1745 * packets, so that we won't get any new data or any
   1746 * packets that change the state of the socket.
   1747 *
   1748 * While locked, BH processing will add new packets to
   1749 * the backlog queue.  This queue is processed by the
   1750 * owner of the socket lock right before it is released.
   1751 *
   1752 * Since ~2.3.5 it is also exclusive sleep lock serializing
   1753 * accesses from user process context.
   1754 */
   1755
   1756static inline void sock_owned_by_me(const struct sock *sk)
   1757{
   1758#ifdef CONFIG_LOCKDEP
   1759	WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
   1760#endif
   1761}
   1762
   1763static inline bool sock_owned_by_user(const struct sock *sk)
   1764{
   1765	sock_owned_by_me(sk);
   1766	return sk->sk_lock.owned;
   1767}
   1768
   1769static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
   1770{
   1771	return sk->sk_lock.owned;
   1772}
   1773
   1774static inline void sock_release_ownership(struct sock *sk)
   1775{
   1776	if (sock_owned_by_user_nocheck(sk)) {
   1777		sk->sk_lock.owned = 0;
   1778
   1779		/* The sk_lock has mutex_unlock() semantics: */
   1780		mutex_release(&sk->sk_lock.dep_map, _RET_IP_);
   1781	}
   1782}
   1783
   1784/* no reclassification while locks are held */
   1785static inline bool sock_allow_reclassification(const struct sock *csk)
   1786{
   1787	struct sock *sk = (struct sock *)csk;
   1788
   1789	return !sock_owned_by_user_nocheck(sk) &&
   1790		!spin_is_locked(&sk->sk_lock.slock);
   1791}
   1792
   1793struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
   1794		      struct proto *prot, int kern);
   1795void sk_free(struct sock *sk);
   1796void sk_destruct(struct sock *sk);
   1797struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
   1798void sk_free_unlock_clone(struct sock *sk);
   1799
   1800struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
   1801			     gfp_t priority);
   1802void __sock_wfree(struct sk_buff *skb);
   1803void sock_wfree(struct sk_buff *skb);
   1804struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
   1805			     gfp_t priority);
   1806void skb_orphan_partial(struct sk_buff *skb);
   1807void sock_rfree(struct sk_buff *skb);
   1808void sock_efree(struct sk_buff *skb);
   1809#ifdef CONFIG_INET
   1810void sock_edemux(struct sk_buff *skb);
   1811void sock_pfree(struct sk_buff *skb);
   1812#else
   1813#define sock_edemux sock_efree
   1814#endif
   1815
   1816int sock_setsockopt(struct socket *sock, int level, int op,
   1817		    sockptr_t optval, unsigned int optlen);
   1818
   1819int sock_getsockopt(struct socket *sock, int level, int op,
   1820		    char __user *optval, int __user *optlen);
   1821int sock_gettstamp(struct socket *sock, void __user *userstamp,
   1822		   bool timeval, bool time32);
   1823struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
   1824				     unsigned long data_len, int noblock,
   1825				     int *errcode, int max_page_order);
   1826
   1827static inline struct sk_buff *sock_alloc_send_skb(struct sock *sk,
   1828						  unsigned long size,
   1829						  int noblock, int *errcode)
   1830{
   1831	return sock_alloc_send_pskb(sk, size, 0, noblock, errcode, 0);
   1832}
   1833
   1834void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
   1835void sock_kfree_s(struct sock *sk, void *mem, int size);
   1836void sock_kzfree_s(struct sock *sk, void *mem, int size);
   1837void sk_send_sigurg(struct sock *sk);
   1838
   1839struct sockcm_cookie {
   1840	u64 transmit_time;
   1841	u32 mark;
   1842	u16 tsflags;
   1843};
   1844
   1845static inline void sockcm_init(struct sockcm_cookie *sockc,
   1846			       const struct sock *sk)
   1847{
   1848	*sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
   1849}
   1850
   1851int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
   1852		     struct sockcm_cookie *sockc);
   1853int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
   1854		   struct sockcm_cookie *sockc);
   1855
   1856/*
   1857 * Functions to fill in entries in struct proto_ops when a protocol
   1858 * does not implement a particular function.
   1859 */
   1860int sock_no_bind(struct socket *, struct sockaddr *, int);
   1861int sock_no_connect(struct socket *, struct sockaddr *, int, int);
   1862int sock_no_socketpair(struct socket *, struct socket *);
   1863int sock_no_accept(struct socket *, struct socket *, int, bool);
   1864int sock_no_getname(struct socket *, struct sockaddr *, int);
   1865int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
   1866int sock_no_listen(struct socket *, int);
   1867int sock_no_shutdown(struct socket *, int);
   1868int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
   1869int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
   1870int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
   1871int sock_no_mmap(struct file *file, struct socket *sock,
   1872		 struct vm_area_struct *vma);
   1873ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
   1874			 size_t size, int flags);
   1875ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
   1876				int offset, size_t size, int flags);
   1877
   1878/*
   1879 * Functions to fill in entries in struct proto_ops when a protocol
   1880 * uses the inet style.
   1881 */
   1882int sock_common_getsockopt(struct socket *sock, int level, int optname,
   1883				  char __user *optval, int __user *optlen);
   1884int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
   1885			int flags);
   1886int sock_common_setsockopt(struct socket *sock, int level, int optname,
   1887			   sockptr_t optval, unsigned int optlen);
   1888
   1889void sk_common_release(struct sock *sk);
   1890
   1891/*
   1892 *	Default socket callbacks and setup code
   1893 */
   1894
   1895/* Initialise core socket variables */
   1896void sock_init_data(struct socket *sock, struct sock *sk);
   1897
   1898/*
   1899 * Socket reference counting postulates.
   1900 *
   1901 * * Each user of socket SHOULD hold a reference count.
   1902 * * Each access point to socket (an hash table bucket, reference from a list,
   1903 *   running timer, skb in flight MUST hold a reference count.
   1904 * * When reference count hits 0, it means it will never increase back.
   1905 * * When reference count hits 0, it means that no references from
   1906 *   outside exist to this socket and current process on current CPU
   1907 *   is last user and may/should destroy this socket.
   1908 * * sk_free is called from any context: process, BH, IRQ. When
   1909 *   it is called, socket has no references from outside -> sk_free
   1910 *   may release descendant resources allocated by the socket, but
   1911 *   to the time when it is called, socket is NOT referenced by any
   1912 *   hash tables, lists etc.
   1913 * * Packets, delivered from outside (from network or from another process)
   1914 *   and enqueued on receive/error queues SHOULD NOT grab reference count,
   1915 *   when they sit in queue. Otherwise, packets will leak to hole, when
   1916 *   socket is looked up by one cpu and unhasing is made by another CPU.
   1917 *   It is true for udp/raw, netlink (leak to receive and error queues), tcp
   1918 *   (leak to backlog). Packet socket does all the processing inside
   1919 *   BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
   1920 *   use separate SMP lock, so that they are prone too.
   1921 */
   1922
   1923/* Ungrab socket and destroy it, if it was the last reference. */
   1924static inline void sock_put(struct sock *sk)
   1925{
   1926	if (refcount_dec_and_test(&sk->sk_refcnt))
   1927		sk_free(sk);
   1928}
   1929/* Generic version of sock_put(), dealing with all sockets
   1930 * (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
   1931 */
   1932void sock_gen_put(struct sock *sk);
   1933
   1934int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
   1935		     unsigned int trim_cap, bool refcounted);
   1936static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
   1937				 const int nested)
   1938{
   1939	return __sk_receive_skb(sk, skb, nested, 1, true);
   1940}
   1941
   1942static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
   1943{
   1944	/* sk_tx_queue_mapping accept only upto a 16-bit value */
   1945	if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
   1946		return;
   1947	sk->sk_tx_queue_mapping = tx_queue;
   1948}
   1949
   1950#define NO_QUEUE_MAPPING	USHRT_MAX
   1951
   1952static inline void sk_tx_queue_clear(struct sock *sk)
   1953{
   1954	sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
   1955}
   1956
   1957static inline int sk_tx_queue_get(const struct sock *sk)
   1958{
   1959	if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
   1960		return sk->sk_tx_queue_mapping;
   1961
   1962	return -1;
   1963}
   1964
   1965static inline void __sk_rx_queue_set(struct sock *sk,
   1966				     const struct sk_buff *skb,
   1967				     bool force_set)
   1968{
   1969#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
   1970	if (skb_rx_queue_recorded(skb)) {
   1971		u16 rx_queue = skb_get_rx_queue(skb);
   1972
   1973		if (force_set ||
   1974		    unlikely(READ_ONCE(sk->sk_rx_queue_mapping) != rx_queue))
   1975			WRITE_ONCE(sk->sk_rx_queue_mapping, rx_queue);
   1976	}
   1977#endif
   1978}
   1979
   1980static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
   1981{
   1982	__sk_rx_queue_set(sk, skb, true);
   1983}
   1984
   1985static inline void sk_rx_queue_update(struct sock *sk, const struct sk_buff *skb)
   1986{
   1987	__sk_rx_queue_set(sk, skb, false);
   1988}
   1989
   1990static inline void sk_rx_queue_clear(struct sock *sk)
   1991{
   1992#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
   1993	WRITE_ONCE(sk->sk_rx_queue_mapping, NO_QUEUE_MAPPING);
   1994#endif
   1995}
   1996
   1997static inline int sk_rx_queue_get(const struct sock *sk)
   1998{
   1999#ifdef CONFIG_SOCK_RX_QUEUE_MAPPING
   2000	if (sk) {
   2001		int res = READ_ONCE(sk->sk_rx_queue_mapping);
   2002
   2003		if (res != NO_QUEUE_MAPPING)
   2004			return res;
   2005	}
   2006#endif
   2007
   2008	return -1;
   2009}
   2010
   2011static inline void sk_set_socket(struct sock *sk, struct socket *sock)
   2012{
   2013	sk->sk_socket = sock;
   2014}
   2015
   2016static inline wait_queue_head_t *sk_sleep(struct sock *sk)
   2017{
   2018	BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
   2019	return &rcu_dereference_raw(sk->sk_wq)->wait;
   2020}
   2021/* Detach socket from process context.
   2022 * Announce socket dead, detach it from wait queue and inode.
   2023 * Note that parent inode held reference count on this struct sock,
   2024 * we do not release it in this function, because protocol
   2025 * probably wants some additional cleanups or even continuing
   2026 * to work with this socket (TCP).
   2027 */
   2028static inline void sock_orphan(struct sock *sk)
   2029{
   2030	write_lock_bh(&sk->sk_callback_lock);
   2031	sock_set_flag(sk, SOCK_DEAD);
   2032	sk_set_socket(sk, NULL);
   2033	sk->sk_wq  = NULL;
   2034	write_unlock_bh(&sk->sk_callback_lock);
   2035}
   2036
   2037static inline void sock_graft(struct sock *sk, struct socket *parent)
   2038{
   2039	WARN_ON(parent->sk);
   2040	write_lock_bh(&sk->sk_callback_lock);
   2041	rcu_assign_pointer(sk->sk_wq, &parent->wq);
   2042	parent->sk = sk;
   2043	sk_set_socket(sk, parent);
   2044	sk->sk_uid = SOCK_INODE(parent)->i_uid;
   2045	security_sock_graft(sk, parent);
   2046	write_unlock_bh(&sk->sk_callback_lock);
   2047}
   2048
   2049kuid_t sock_i_uid(struct sock *sk);
   2050unsigned long sock_i_ino(struct sock *sk);
   2051
   2052static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
   2053{
   2054	return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
   2055}
   2056
   2057static inline u32 net_tx_rndhash(void)
   2058{
   2059	u32 v = prandom_u32();
   2060
   2061	return v ?: 1;
   2062}
   2063
   2064static inline void sk_set_txhash(struct sock *sk)
   2065{
   2066	/* This pairs with READ_ONCE() in skb_set_hash_from_sk() */
   2067	WRITE_ONCE(sk->sk_txhash, net_tx_rndhash());
   2068}
   2069
   2070static inline bool sk_rethink_txhash(struct sock *sk)
   2071{
   2072	if (sk->sk_txhash && sk->sk_txrehash == SOCK_TXREHASH_ENABLED) {
   2073		sk_set_txhash(sk);
   2074		return true;
   2075	}
   2076	return false;
   2077}
   2078
   2079static inline struct dst_entry *
   2080__sk_dst_get(struct sock *sk)
   2081{
   2082	return rcu_dereference_check(sk->sk_dst_cache,
   2083				     lockdep_sock_is_held(sk));
   2084}
   2085
   2086static inline struct dst_entry *
   2087sk_dst_get(struct sock *sk)
   2088{
   2089	struct dst_entry *dst;
   2090
   2091	rcu_read_lock();
   2092	dst = rcu_dereference(sk->sk_dst_cache);
   2093	if (dst && !atomic_inc_not_zero(&dst->__refcnt))
   2094		dst = NULL;
   2095	rcu_read_unlock();
   2096	return dst;
   2097}
   2098
   2099static inline void __dst_negative_advice(struct sock *sk)
   2100{
   2101	struct dst_entry *ndst, *dst = __sk_dst_get(sk);
   2102
   2103	if (dst && dst->ops->negative_advice) {
   2104		ndst = dst->ops->negative_advice(dst);
   2105
   2106		if (ndst != dst) {
   2107			rcu_assign_pointer(sk->sk_dst_cache, ndst);
   2108			sk_tx_queue_clear(sk);
   2109			sk->sk_dst_pending_confirm = 0;
   2110		}
   2111	}
   2112}
   2113
   2114static inline void dst_negative_advice(struct sock *sk)
   2115{
   2116	sk_rethink_txhash(sk);
   2117	__dst_negative_advice(sk);
   2118}
   2119
   2120static inline void
   2121__sk_dst_set(struct sock *sk, struct dst_entry *dst)
   2122{
   2123	struct dst_entry *old_dst;
   2124
   2125	sk_tx_queue_clear(sk);
   2126	sk->sk_dst_pending_confirm = 0;
   2127	old_dst = rcu_dereference_protected(sk->sk_dst_cache,
   2128					    lockdep_sock_is_held(sk));
   2129	rcu_assign_pointer(sk->sk_dst_cache, dst);
   2130	dst_release(old_dst);
   2131}
   2132
   2133static inline void
   2134sk_dst_set(struct sock *sk, struct dst_entry *dst)
   2135{
   2136	struct dst_entry *old_dst;
   2137
   2138	sk_tx_queue_clear(sk);
   2139	sk->sk_dst_pending_confirm = 0;
   2140	old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
   2141	dst_release(old_dst);
   2142}
   2143
   2144static inline void
   2145__sk_dst_reset(struct sock *sk)
   2146{
   2147	__sk_dst_set(sk, NULL);
   2148}
   2149
   2150static inline void
   2151sk_dst_reset(struct sock *sk)
   2152{
   2153	sk_dst_set(sk, NULL);
   2154}
   2155
   2156struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
   2157
   2158struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
   2159
   2160static inline void sk_dst_confirm(struct sock *sk)
   2161{
   2162	if (!READ_ONCE(sk->sk_dst_pending_confirm))
   2163		WRITE_ONCE(sk->sk_dst_pending_confirm, 1);
   2164}
   2165
   2166static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
   2167{
   2168	if (skb_get_dst_pending_confirm(skb)) {
   2169		struct sock *sk = skb->sk;
   2170
   2171		if (sk && READ_ONCE(sk->sk_dst_pending_confirm))
   2172			WRITE_ONCE(sk->sk_dst_pending_confirm, 0);
   2173		neigh_confirm(n);
   2174	}
   2175}
   2176
   2177bool sk_mc_loop(struct sock *sk);
   2178
   2179static inline bool sk_can_gso(const struct sock *sk)
   2180{
   2181	return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
   2182}
   2183
   2184void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
   2185
   2186static inline void sk_gso_disable(struct sock *sk)
   2187{
   2188	sk->sk_gso_disabled = 1;
   2189	sk->sk_route_caps &= ~NETIF_F_GSO_MASK;
   2190}
   2191
   2192static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
   2193					   struct iov_iter *from, char *to,
   2194					   int copy, int offset)
   2195{
   2196	if (skb->ip_summed == CHECKSUM_NONE) {
   2197		__wsum csum = 0;
   2198		if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
   2199			return -EFAULT;
   2200		skb->csum = csum_block_add(skb->csum, csum, offset);
   2201	} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
   2202		if (!copy_from_iter_full_nocache(to, copy, from))
   2203			return -EFAULT;
   2204	} else if (!copy_from_iter_full(to, copy, from))
   2205		return -EFAULT;
   2206
   2207	return 0;
   2208}
   2209
   2210static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
   2211				       struct iov_iter *from, int copy)
   2212{
   2213	int err, offset = skb->len;
   2214
   2215	err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
   2216				       copy, offset);
   2217	if (err)
   2218		__skb_trim(skb, offset);
   2219
   2220	return err;
   2221}
   2222
   2223static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
   2224					   struct sk_buff *skb,
   2225					   struct page *page,
   2226					   int off, int copy)
   2227{
   2228	int err;
   2229
   2230	err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
   2231				       copy, skb->len);
   2232	if (err)
   2233		return err;
   2234
   2235	skb->len	     += copy;
   2236	skb->data_len	     += copy;
   2237	skb->truesize	     += copy;
   2238	sk_wmem_queued_add(sk, copy);
   2239	sk_mem_charge(sk, copy);
   2240	return 0;
   2241}
   2242
   2243/**
   2244 * sk_wmem_alloc_get - returns write allocations
   2245 * @sk: socket
   2246 *
   2247 * Return: sk_wmem_alloc minus initial offset of one
   2248 */
   2249static inline int sk_wmem_alloc_get(const struct sock *sk)
   2250{
   2251	return refcount_read(&sk->sk_wmem_alloc) - 1;
   2252}
   2253
   2254/**
   2255 * sk_rmem_alloc_get - returns read allocations
   2256 * @sk: socket
   2257 *
   2258 * Return: sk_rmem_alloc
   2259 */
   2260static inline int sk_rmem_alloc_get(const struct sock *sk)
   2261{
   2262	return atomic_read(&sk->sk_rmem_alloc);
   2263}
   2264
   2265/**
   2266 * sk_has_allocations - check if allocations are outstanding
   2267 * @sk: socket
   2268 *
   2269 * Return: true if socket has write or read allocations
   2270 */
   2271static inline bool sk_has_allocations(const struct sock *sk)
   2272{
   2273	return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
   2274}
   2275
   2276/**
   2277 * skwq_has_sleeper - check if there are any waiting processes
   2278 * @wq: struct socket_wq
   2279 *
   2280 * Return: true if socket_wq has waiting processes
   2281 *
   2282 * The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
   2283 * barrier call. They were added due to the race found within the tcp code.
   2284 *
   2285 * Consider following tcp code paths::
   2286 *
   2287 *   CPU1                CPU2
   2288 *   sys_select          receive packet
   2289 *   ...                 ...
   2290 *   __add_wait_queue    update tp->rcv_nxt
   2291 *   ...                 ...
   2292 *   tp->rcv_nxt check   sock_def_readable
   2293 *   ...                 {
   2294 *   schedule               rcu_read_lock();
   2295 *                          wq = rcu_dereference(sk->sk_wq);
   2296 *                          if (wq && waitqueue_active(&wq->wait))
   2297 *                              wake_up_interruptible(&wq->wait)
   2298 *                          ...
   2299 *                       }
   2300 *
   2301 * The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
   2302 * in its cache, and so does the tp->rcv_nxt update on CPU2 side.  The CPU1
   2303 * could then endup calling schedule and sleep forever if there are no more
   2304 * data on the socket.
   2305 *
   2306 */
   2307static inline bool skwq_has_sleeper(struct socket_wq *wq)
   2308{
   2309	return wq && wq_has_sleeper(&wq->wait);
   2310}
   2311
   2312/**
   2313 * sock_poll_wait - place memory barrier behind the poll_wait call.
   2314 * @filp:           file
   2315 * @sock:           socket to wait on
   2316 * @p:              poll_table
   2317 *
   2318 * See the comments in the wq_has_sleeper function.
   2319 */
   2320static inline void sock_poll_wait(struct file *filp, struct socket *sock,
   2321				  poll_table *p)
   2322{
   2323	if (!poll_does_not_wait(p)) {
   2324		poll_wait(filp, &sock->wq.wait, p);
   2325		/* We need to be sure we are in sync with the
   2326		 * socket flags modification.
   2327		 *
   2328		 * This memory barrier is paired in the wq_has_sleeper.
   2329		 */
   2330		smp_mb();
   2331	}
   2332}
   2333
   2334static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
   2335{
   2336	/* This pairs with WRITE_ONCE() in sk_set_txhash() */
   2337	u32 txhash = READ_ONCE(sk->sk_txhash);
   2338
   2339	if (txhash) {
   2340		skb->l4_hash = 1;
   2341		skb->hash = txhash;
   2342	}
   2343}
   2344
   2345void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
   2346
   2347/*
   2348 *	Queue a received datagram if it will fit. Stream and sequenced
   2349 *	protocols can't normally use this as they need to fit buffers in
   2350 *	and play with them.
   2351 *
   2352 *	Inlined as it's very short and called for pretty much every
   2353 *	packet ever received.
   2354 */
   2355static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
   2356{
   2357	skb_orphan(skb);
   2358	skb->sk = sk;
   2359	skb->destructor = sock_rfree;
   2360	atomic_add(skb->truesize, &sk->sk_rmem_alloc);
   2361	sk_mem_charge(sk, skb->truesize);
   2362}
   2363
   2364static inline __must_check bool skb_set_owner_sk_safe(struct sk_buff *skb, struct sock *sk)
   2365{
   2366	if (sk && refcount_inc_not_zero(&sk->sk_refcnt)) {
   2367		skb_orphan(skb);
   2368		skb->destructor = sock_efree;
   2369		skb->sk = sk;
   2370		return true;
   2371	}
   2372	return false;
   2373}
   2374
   2375static inline void skb_prepare_for_gro(struct sk_buff *skb)
   2376{
   2377	if (skb->destructor != sock_wfree) {
   2378		skb_orphan(skb);
   2379		return;
   2380	}
   2381	skb->slow_gro = 1;
   2382}
   2383
   2384void sk_reset_timer(struct sock *sk, struct timer_list *timer,
   2385		    unsigned long expires);
   2386
   2387void sk_stop_timer(struct sock *sk, struct timer_list *timer);
   2388
   2389void sk_stop_timer_sync(struct sock *sk, struct timer_list *timer);
   2390
   2391int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
   2392			struct sk_buff *skb, unsigned int flags,
   2393			void (*destructor)(struct sock *sk,
   2394					   struct sk_buff *skb));
   2395int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
   2396
   2397int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
   2398			      enum skb_drop_reason *reason);
   2399
   2400static inline int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
   2401{
   2402	return sock_queue_rcv_skb_reason(sk, skb, NULL);
   2403}
   2404
   2405int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
   2406struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
   2407
   2408/*
   2409 *	Recover an error report and clear atomically
   2410 */
   2411
   2412static inline int sock_error(struct sock *sk)
   2413{
   2414	int err;
   2415
   2416	/* Avoid an atomic operation for the common case.
   2417	 * This is racy since another cpu/thread can change sk_err under us.
   2418	 */
   2419	if (likely(data_race(!sk->sk_err)))
   2420		return 0;
   2421
   2422	err = xchg(&sk->sk_err, 0);
   2423	return -err;
   2424}
   2425
   2426void sk_error_report(struct sock *sk);
   2427
   2428static inline unsigned long sock_wspace(struct sock *sk)
   2429{
   2430	int amt = 0;
   2431
   2432	if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
   2433		amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
   2434		if (amt < 0)
   2435			amt = 0;
   2436	}
   2437	return amt;
   2438}
   2439
   2440/* Note:
   2441 *  We use sk->sk_wq_raw, from contexts knowing this
   2442 *  pointer is not NULL and cannot disappear/change.
   2443 */
   2444static inline void sk_set_bit(int nr, struct sock *sk)
   2445{
   2446	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
   2447	    !sock_flag(sk, SOCK_FASYNC))
   2448		return;
   2449
   2450	set_bit(nr, &sk->sk_wq_raw->flags);
   2451}
   2452
   2453static inline void sk_clear_bit(int nr, struct sock *sk)
   2454{
   2455	if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
   2456	    !sock_flag(sk, SOCK_FASYNC))
   2457		return;
   2458
   2459	clear_bit(nr, &sk->sk_wq_raw->flags);
   2460}
   2461
   2462static inline void sk_wake_async(const struct sock *sk, int how, int band)
   2463{
   2464	if (sock_flag(sk, SOCK_FASYNC)) {
   2465		rcu_read_lock();
   2466		sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
   2467		rcu_read_unlock();
   2468	}
   2469}
   2470
   2471/* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
   2472 * need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
   2473 * Note: for send buffers, TCP works better if we can build two skbs at
   2474 * minimum.
   2475 */
   2476#define TCP_SKB_MIN_TRUESIZE	(2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
   2477
   2478#define SOCK_MIN_SNDBUF		(TCP_SKB_MIN_TRUESIZE * 2)
   2479#define SOCK_MIN_RCVBUF		 TCP_SKB_MIN_TRUESIZE
   2480
   2481static inline void sk_stream_moderate_sndbuf(struct sock *sk)
   2482{
   2483	u32 val;
   2484
   2485	if (sk->sk_userlocks & SOCK_SNDBUF_LOCK)
   2486		return;
   2487
   2488	val = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
   2489	val = max_t(u32, val, sk_unused_reserved_mem(sk));
   2490
   2491	WRITE_ONCE(sk->sk_sndbuf, max_t(u32, val, SOCK_MIN_SNDBUF));
   2492}
   2493
   2494/**
   2495 * sk_page_frag - return an appropriate page_frag
   2496 * @sk: socket
   2497 *
   2498 * Use the per task page_frag instead of the per socket one for
   2499 * optimization when we know that we're in process context and own
   2500 * everything that's associated with %current.
   2501 *
   2502 * Both direct reclaim and page faults can nest inside other
   2503 * socket operations and end up recursing into sk_page_frag()
   2504 * while it's already in use: explicitly avoid task page_frag
   2505 * usage if the caller is potentially doing any of them.
   2506 * This assumes that page fault handlers use the GFP_NOFS flags.
   2507 *
   2508 * Return: a per task page_frag if context allows that,
   2509 * otherwise a per socket one.
   2510 */
   2511static inline struct page_frag *sk_page_frag(struct sock *sk)
   2512{
   2513	if ((sk->sk_allocation & (__GFP_DIRECT_RECLAIM | __GFP_MEMALLOC | __GFP_FS)) ==
   2514	    (__GFP_DIRECT_RECLAIM | __GFP_FS))
   2515		return &current->task_frag;
   2516
   2517	return &sk->sk_frag;
   2518}
   2519
   2520bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
   2521
   2522/*
   2523 *	Default write policy as shown to user space via poll/select/SIGIO
   2524 */
   2525static inline bool sock_writeable(const struct sock *sk)
   2526{
   2527	return refcount_read(&sk->sk_wmem_alloc) < (READ_ONCE(sk->sk_sndbuf) >> 1);
   2528}
   2529
   2530static inline gfp_t gfp_any(void)
   2531{
   2532	return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
   2533}
   2534
   2535static inline gfp_t gfp_memcg_charge(void)
   2536{
   2537	return in_softirq() ? GFP_NOWAIT : GFP_KERNEL;
   2538}
   2539
   2540static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
   2541{
   2542	return noblock ? 0 : sk->sk_rcvtimeo;
   2543}
   2544
   2545static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
   2546{
   2547	return noblock ? 0 : sk->sk_sndtimeo;
   2548}
   2549
   2550static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
   2551{
   2552	int v = waitall ? len : min_t(int, READ_ONCE(sk->sk_rcvlowat), len);
   2553
   2554	return v ?: 1;
   2555}
   2556
   2557/* Alas, with timeout socket operations are not restartable.
   2558 * Compare this to poll().
   2559 */
   2560static inline int sock_intr_errno(long timeo)
   2561{
   2562	return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
   2563}
   2564
   2565struct sock_skb_cb {
   2566	u32 dropcount;
   2567};
   2568
   2569/* Store sock_skb_cb at the end of skb->cb[] so protocol families
   2570 * using skb->cb[] would keep using it directly and utilize its
   2571 * alignement guarantee.
   2572 */
   2573#define SOCK_SKB_CB_OFFSET ((sizeof_field(struct sk_buff, cb) - \
   2574			    sizeof(struct sock_skb_cb)))
   2575
   2576#define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
   2577			    SOCK_SKB_CB_OFFSET))
   2578
   2579#define sock_skb_cb_check_size(size) \
   2580	BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
   2581
   2582static inline void
   2583sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
   2584{
   2585	SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
   2586						atomic_read(&sk->sk_drops) : 0;
   2587}
   2588
   2589static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
   2590{
   2591	int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
   2592
   2593	atomic_add(segs, &sk->sk_drops);
   2594}
   2595
   2596static inline ktime_t sock_read_timestamp(struct sock *sk)
   2597{
   2598#if BITS_PER_LONG==32
   2599	unsigned int seq;
   2600	ktime_t kt;
   2601
   2602	do {
   2603		seq = read_seqbegin(&sk->sk_stamp_seq);
   2604		kt = sk->sk_stamp;
   2605	} while (read_seqretry(&sk->sk_stamp_seq, seq));
   2606
   2607	return kt;
   2608#else
   2609	return READ_ONCE(sk->sk_stamp);
   2610#endif
   2611}
   2612
   2613static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
   2614{
   2615#if BITS_PER_LONG==32
   2616	write_seqlock(&sk->sk_stamp_seq);
   2617	sk->sk_stamp = kt;
   2618	write_sequnlock(&sk->sk_stamp_seq);
   2619#else
   2620	WRITE_ONCE(sk->sk_stamp, kt);
   2621#endif
   2622}
   2623
   2624void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
   2625			   struct sk_buff *skb);
   2626void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
   2627			     struct sk_buff *skb);
   2628
   2629static inline void
   2630sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
   2631{
   2632	ktime_t kt = skb->tstamp;
   2633	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
   2634
   2635	/*
   2636	 * generate control messages if
   2637	 * - receive time stamping in software requested
   2638	 * - software time stamp available and wanted
   2639	 * - hardware time stamps available and wanted
   2640	 */
   2641	if (sock_flag(sk, SOCK_RCVTSTAMP) ||
   2642	    (sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
   2643	    (kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
   2644	    (hwtstamps->hwtstamp &&
   2645	     (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
   2646		__sock_recv_timestamp(msg, sk, skb);
   2647	else
   2648		sock_write_timestamp(sk, kt);
   2649
   2650	if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
   2651		__sock_recv_wifi_status(msg, sk, skb);
   2652}
   2653
   2654void __sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
   2655		       struct sk_buff *skb);
   2656
   2657#define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
   2658static inline void sock_recv_cmsgs(struct msghdr *msg, struct sock *sk,
   2659				   struct sk_buff *skb)
   2660{
   2661#define FLAGS_RECV_CMSGS ((1UL << SOCK_RXQ_OVFL)			| \
   2662			   (1UL << SOCK_RCVTSTAMP)			| \
   2663			   (1UL << SOCK_RCVMARK))
   2664#define TSFLAGS_ANY	  (SOF_TIMESTAMPING_SOFTWARE			| \
   2665			   SOF_TIMESTAMPING_RAW_HARDWARE)
   2666
   2667	if (sk->sk_flags & FLAGS_RECV_CMSGS || sk->sk_tsflags & TSFLAGS_ANY)
   2668		__sock_recv_cmsgs(msg, sk, skb);
   2669	else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
   2670		sock_write_timestamp(sk, skb->tstamp);
   2671	else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
   2672		sock_write_timestamp(sk, 0);
   2673}
   2674
   2675void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
   2676
   2677/**
   2678 * _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
   2679 * @sk:		socket sending this packet
   2680 * @tsflags:	timestamping flags to use
   2681 * @tx_flags:	completed with instructions for time stamping
   2682 * @tskey:      filled in with next sk_tskey (not for TCP, which uses seqno)
   2683 *
   2684 * Note: callers should take care of initial ``*tx_flags`` value (usually 0)
   2685 */
   2686static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
   2687				      __u8 *tx_flags, __u32 *tskey)
   2688{
   2689	if (unlikely(tsflags)) {
   2690		__sock_tx_timestamp(tsflags, tx_flags);
   2691		if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
   2692		    tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
   2693			*tskey = atomic_inc_return(&sk->sk_tskey) - 1;
   2694	}
   2695	if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
   2696		*tx_flags |= SKBTX_WIFI_STATUS;
   2697}
   2698
   2699static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
   2700				     __u8 *tx_flags)
   2701{
   2702	_sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
   2703}
   2704
   2705static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
   2706{
   2707	_sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
   2708			   &skb_shinfo(skb)->tskey);
   2709}
   2710
   2711static inline bool sk_is_tcp(const struct sock *sk)
   2712{
   2713	return sk->sk_type == SOCK_STREAM && sk->sk_protocol == IPPROTO_TCP;
   2714}
   2715
   2716/**
   2717 * sk_eat_skb - Release a skb if it is no longer needed
   2718 * @sk: socket to eat this skb from
   2719 * @skb: socket buffer to eat
   2720 *
   2721 * This routine must be called with interrupts disabled or with the socket
   2722 * locked so that the sk_buff queue operation is ok.
   2723*/
   2724static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
   2725{
   2726	__skb_unlink(skb, &sk->sk_receive_queue);
   2727	__kfree_skb(skb);
   2728}
   2729
   2730static inline bool
   2731skb_sk_is_prefetched(struct sk_buff *skb)
   2732{
   2733#ifdef CONFIG_INET
   2734	return skb->destructor == sock_pfree;
   2735#else
   2736	return false;
   2737#endif /* CONFIG_INET */
   2738}
   2739
   2740/* This helper checks if a socket is a full socket,
   2741 * ie _not_ a timewait or request socket.
   2742 */
   2743static inline bool sk_fullsock(const struct sock *sk)
   2744{
   2745	return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
   2746}
   2747
   2748static inline bool
   2749sk_is_refcounted(struct sock *sk)
   2750{
   2751	/* Only full sockets have sk->sk_flags. */
   2752	return !sk_fullsock(sk) || !sock_flag(sk, SOCK_RCU_FREE);
   2753}
   2754
   2755/**
   2756 * skb_steal_sock - steal a socket from an sk_buff
   2757 * @skb: sk_buff to steal the socket from
   2758 * @refcounted: is set to true if the socket is reference-counted
   2759 */
   2760static inline struct sock *
   2761skb_steal_sock(struct sk_buff *skb, bool *refcounted)
   2762{
   2763	if (skb->sk) {
   2764		struct sock *sk = skb->sk;
   2765
   2766		*refcounted = true;
   2767		if (skb_sk_is_prefetched(skb))
   2768			*refcounted = sk_is_refcounted(sk);
   2769		skb->destructor = NULL;
   2770		skb->sk = NULL;
   2771		return sk;
   2772	}
   2773	*refcounted = false;
   2774	return NULL;
   2775}
   2776
   2777/* Checks if this SKB belongs to an HW offloaded socket
   2778 * and whether any SW fallbacks are required based on dev.
   2779 * Check decrypted mark in case skb_orphan() cleared socket.
   2780 */
   2781static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
   2782						   struct net_device *dev)
   2783{
   2784#ifdef CONFIG_SOCK_VALIDATE_XMIT
   2785	struct sock *sk = skb->sk;
   2786
   2787	if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb) {
   2788		skb = sk->sk_validate_xmit_skb(sk, dev, skb);
   2789#ifdef CONFIG_TLS_DEVICE
   2790	} else if (unlikely(skb->decrypted)) {
   2791		pr_warn_ratelimited("unencrypted skb with no associated socket - dropping\n");
   2792		kfree_skb(skb);
   2793		skb = NULL;
   2794#endif
   2795	}
   2796#endif
   2797
   2798	return skb;
   2799}
   2800
   2801/* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
   2802 * SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
   2803 */
   2804static inline bool sk_listener(const struct sock *sk)
   2805{
   2806	return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
   2807}
   2808
   2809void sock_enable_timestamp(struct sock *sk, enum sock_flags flag);
   2810int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
   2811		       int type);
   2812
   2813bool sk_ns_capable(const struct sock *sk,
   2814		   struct user_namespace *user_ns, int cap);
   2815bool sk_capable(const struct sock *sk, int cap);
   2816bool sk_net_capable(const struct sock *sk, int cap);
   2817
   2818void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
   2819
   2820/* Take into consideration the size of the struct sk_buff overhead in the
   2821 * determination of these values, since that is non-constant across
   2822 * platforms.  This makes socket queueing behavior and performance
   2823 * not depend upon such differences.
   2824 */
   2825#define _SK_MEM_PACKETS		256
   2826#define _SK_MEM_OVERHEAD	SKB_TRUESIZE(256)
   2827#define SK_WMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
   2828#define SK_RMEM_MAX		(_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
   2829
   2830extern __u32 sysctl_wmem_max;
   2831extern __u32 sysctl_rmem_max;
   2832
   2833extern int sysctl_tstamp_allow_data;
   2834extern int sysctl_optmem_max;
   2835
   2836extern __u32 sysctl_wmem_default;
   2837extern __u32 sysctl_rmem_default;
   2838
   2839#define SKB_FRAG_PAGE_ORDER	get_order(32768)
   2840DECLARE_STATIC_KEY_FALSE(net_high_order_alloc_disable_key);
   2841
   2842static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
   2843{
   2844	/* Does this proto have per netns sysctl_wmem ? */
   2845	if (proto->sysctl_wmem_offset)
   2846		return *(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset);
   2847
   2848	return *proto->sysctl_wmem;
   2849}
   2850
   2851static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
   2852{
   2853	/* Does this proto have per netns sysctl_rmem ? */
   2854	if (proto->sysctl_rmem_offset)
   2855		return *(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset);
   2856
   2857	return *proto->sysctl_rmem;
   2858}
   2859
   2860/* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
   2861 * Some wifi drivers need to tweak it to get more chunks.
   2862 * They can use this helper from their ndo_start_xmit()
   2863 */
   2864static inline void sk_pacing_shift_update(struct sock *sk, int val)
   2865{
   2866	if (!sk || !sk_fullsock(sk) || READ_ONCE(sk->sk_pacing_shift) == val)
   2867		return;
   2868	WRITE_ONCE(sk->sk_pacing_shift, val);
   2869}
   2870
   2871/* if a socket is bound to a device, check that the given device
   2872 * index is either the same or that the socket is bound to an L3
   2873 * master device and the given device index is also enslaved to
   2874 * that L3 master
   2875 */
   2876static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
   2877{
   2878	int bound_dev_if = READ_ONCE(sk->sk_bound_dev_if);
   2879	int mdif;
   2880
   2881	if (!bound_dev_if || bound_dev_if == dif)
   2882		return true;
   2883
   2884	mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
   2885	if (mdif && mdif == bound_dev_if)
   2886		return true;
   2887
   2888	return false;
   2889}
   2890
   2891void sock_def_readable(struct sock *sk);
   2892
   2893int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
   2894void sock_set_timestamp(struct sock *sk, int optname, bool valbool);
   2895int sock_set_timestamping(struct sock *sk, int optname,
   2896			  struct so_timestamping timestamping);
   2897
   2898void sock_enable_timestamps(struct sock *sk);
   2899void sock_no_linger(struct sock *sk);
   2900void sock_set_keepalive(struct sock *sk);
   2901void sock_set_priority(struct sock *sk, u32 priority);
   2902void sock_set_rcvbuf(struct sock *sk, int val);
   2903void sock_set_mark(struct sock *sk, u32 val);
   2904void sock_set_reuseaddr(struct sock *sk);
   2905void sock_set_reuseport(struct sock *sk);
   2906void sock_set_sndtimeo(struct sock *sk, s64 secs);
   2907
   2908int sock_bind_add(struct sock *sk, struct sockaddr *addr, int addr_len);
   2909
   2910int sock_get_timeout(long timeo, void *optval, bool old_timeval);
   2911int sock_copy_user_timeval(struct __kernel_sock_timeval *tv,
   2912			   sockptr_t optval, int optlen, bool old_timeval);
   2913
   2914static inline bool sk_is_readable(struct sock *sk)
   2915{
   2916	if (sk->sk_prot->sock_is_readable)
   2917		return sk->sk_prot->sock_is_readable(sk);
   2918	return false;
   2919}
   2920#endif	/* _SOCK_H */