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sock.h
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sock.h
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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Definitions for the AF_INET socket handler.
*
* Version: @(#)sock.h 1.0.4 05/13/93
*
* Authors: Ross Biro
* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
* Corey Minyard <wf-rch!minyard@relay.EU.net>
* Florian La Roche <flla@stud.uni-sb.de>
*
* Fixes:
* Alan Cox : Volatiles in skbuff pointers. See
* skbuff comments. May be overdone,
* better to prove they can be removed
* than the reverse.
* Alan Cox : Added a zapped field for tcp to note
* a socket is reset and must stay shut up
* Alan Cox : New fields for options
* Pauline Middelink : identd support
* Alan Cox : Eliminate low level recv/recvfrom
* David S. Miller : New socket lookup architecture.
* Steve Whitehouse: Default routines for sock_ops
* Arnaldo C. Melo : removed net_pinfo, tp_pinfo and made
* protinfo be just a void pointer, as the
* protocol specific parts were moved to
* respective headers and ipv4/v6, etc now
* use private slabcaches for its socks
* Pedro Hortas : New flags field for socket options
*/
#ifndef _SOCK_H
#define _SOCK_H
#include <linux/hardirq.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/list_nulls.h>
#include <linux/timer.h>
#include <linux/cache.h>
#include <linux/bitops.h>
#include <linux/lockdep.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h> /* struct sk_buff */
#include <linux/mm.h>
#include <linux/security.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/page_counter.h>
#include <linux/memcontrol.h>
#include <linux/static_key.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/cgroup-defs.h>
#include <linux/rbtree.h>
#include <linux/filter.h>
#include <linux/rculist_nulls.h>
#include <linux/poll.h>
#include <linux/atomic.h>
#include <linux/refcount.h>
#include <net/dst.h>
#include <net/checksum.h>
#include <net/tcp_states.h>
#include <linux/net_tstamp.h>
#include <net/l3mdev.h>
/*
* This structure really needs to be cleaned up.
* Most of it is for TCP, and not used by any of
* the other protocols.
*/
/* Define this to get the SOCK_DBG debugging facility. */
#define SOCK_DEBUGGING
#ifdef SOCK_DEBUGGING
#define SOCK_DEBUG(sk, msg...) do { if ((sk) && sock_flag((sk), SOCK_DBG)) \
printk(KERN_DEBUG msg); } while (0)
#else
/* Validate arguments and do nothing */
static inline __printf(2, 3)
void SOCK_DEBUG(const struct sock *sk, const char *msg, ...)
{
}
#endif
/* This is the per-socket lock. The spinlock provides a synchronization
* between user contexts and software interrupt processing, whereas the
* mini-semaphore synchronizes multiple users amongst themselves.
*/
typedef struct {
spinlock_t slock;
int owned;
wait_queue_head_t wq;
/*
* We express the mutex-alike socket_lock semantics
* to the lock validator by explicitly managing
* the slock as a lock variant (in addition to
* the slock itself):
*/
#ifdef CONFIG_DEBUG_LOCK_ALLOC
struct lockdep_map dep_map;
#endif
} socket_lock_t;
struct sock;
struct proto;
struct net;
typedef __u32 __bitwise __portpair;
typedef __u64 __bitwise __addrpair;
/**
* struct sock_common - minimal network layer representation of sockets
* @skc_daddr: Foreign IPv4 addr
* @skc_rcv_saddr: Bound local IPv4 addr
* @skc_addrpair: 8-byte-aligned __u64 union of @skc_daddr & @skc_rcv_saddr
* @skc_hash: hash value used with various protocol lookup tables
* @skc_u16hashes: two u16 hash values used by UDP lookup tables
* @skc_dport: placeholder for inet_dport/tw_dport
* @skc_num: placeholder for inet_num/tw_num
* @skc_portpair: __u32 union of @skc_dport & @skc_num
* @skc_family: network address family
* @skc_state: Connection state
* @skc_reuse: %SO_REUSEADDR setting
* @skc_reuseport: %SO_REUSEPORT setting
* @skc_ipv6only: socket is IPV6 only
* @skc_net_refcnt: socket is using net ref counting
* @skc_bound_dev_if: bound device index if != 0
* @skc_bind_node: bind hash linkage for various protocol lookup tables
* @skc_portaddr_node: second hash linkage for UDP/UDP-Lite protocol
* @skc_prot: protocol handlers inside a network family
* @skc_net: reference to the network namespace of this socket
* @skc_v6_daddr: IPV6 destination address
* @skc_v6_rcv_saddr: IPV6 source address
* @skc_cookie: socket's cookie value
* @skc_node: main hash linkage for various protocol lookup tables
* @skc_nulls_node: main hash linkage for TCP/UDP/UDP-Lite protocol
* @skc_tx_queue_mapping: tx queue number for this connection
* @skc_rx_queue_mapping: rx queue number for this connection
* @skc_flags: place holder for sk_flags
* %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE,
* %SO_OOBINLINE settings, %SO_TIMESTAMPING settings
* @skc_listener: connection request listener socket (aka rsk_listener)
* [union with @skc_flags]
* @skc_tw_dr: (aka tw_dr) ptr to &struct inet_timewait_death_row
* [union with @skc_flags]
* @skc_incoming_cpu: record/match cpu processing incoming packets
* @skc_rcv_wnd: (aka rsk_rcv_wnd) TCP receive window size (possibly scaled)
* [union with @skc_incoming_cpu]
* @skc_tw_rcv_nxt: (aka tw_rcv_nxt) TCP window next expected seq number
* [union with @skc_incoming_cpu]
* @skc_refcnt: reference count
*
* This is the minimal network layer representation of sockets, the header
* for struct sock and struct inet_timewait_sock.
*/
struct sock_common {
/* skc_daddr and skc_rcv_saddr must be grouped on a 8 bytes aligned
* address on 64bit arches : cf INET_MATCH()
*/
union {
__addrpair skc_addrpair;
struct {
__be32 skc_daddr;
__be32 skc_rcv_saddr;
};
};
union {
unsigned int skc_hash;
__u16 skc_u16hashes[2];
};
/* skc_dport && skc_num must be grouped as well */
union {
__portpair skc_portpair;
struct {
__be16 skc_dport;
__u16 skc_num;
};
};
unsigned short skc_family;
volatile unsigned char skc_state;
unsigned char skc_reuse:4;
unsigned char skc_reuseport:1;
unsigned char skc_ipv6only:1;
unsigned char skc_net_refcnt:1;
int skc_bound_dev_if;
union {
struct hlist_node skc_bind_node;
struct hlist_node skc_portaddr_node;
};
struct proto *skc_prot;
possible_net_t skc_net;
#if IS_ENABLED(CONFIG_IPV6)
struct in6_addr skc_v6_daddr;
struct in6_addr skc_v6_rcv_saddr;
#endif
atomic64_t skc_cookie;
/* following fields are padding to force
* offset(struct sock, sk_refcnt) == 128 on 64bit arches
* assuming IPV6 is enabled. We use this padding differently
* for different kind of 'sockets'
*/
union {
unsigned long skc_flags;
struct sock *skc_listener; /* request_sock */
struct inet_timewait_death_row *skc_tw_dr; /* inet_timewait_sock */
};
/*
* fields between dontcopy_begin/dontcopy_end
* are not copied in sock_copy()
*/
/* private: */
int skc_dontcopy_begin[0];
/* public: */
union {
struct hlist_node skc_node;
struct hlist_nulls_node skc_nulls_node;
};
unsigned short skc_tx_queue_mapping;
#ifdef CONFIG_XPS
unsigned short skc_rx_queue_mapping;
#endif
union {
int skc_incoming_cpu;
u32 skc_rcv_wnd;
u32 skc_tw_rcv_nxt; /* struct tcp_timewait_sock */
};
refcount_t skc_refcnt;
/* private: */
int skc_dontcopy_end[0];
union {
u32 skc_rxhash;
u32 skc_window_clamp;
u32 skc_tw_snd_nxt; /* struct tcp_timewait_sock */
};
/* public: */
};
struct bpf_sk_storage;
/**
* struct sock - network layer representation of sockets
* @__sk_common: shared layout with inet_timewait_sock
* @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN
* @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings
* @sk_lock: synchronizer
* @sk_kern_sock: True if sock is using kernel lock classes
* @sk_rcvbuf: size of receive buffer in bytes
* @sk_wq: sock wait queue and async head
* @sk_rx_dst: receive input route used by early demux
* @sk_dst_cache: destination cache
* @sk_dst_pending_confirm: need to confirm neighbour
* @sk_policy: flow policy
* @sk_rx_skb_cache: cache copy of recently accessed RX skb
* @sk_receive_queue: incoming packets
* @sk_wmem_alloc: transmit queue bytes committed
* @sk_tsq_flags: TCP Small Queues flags
* @sk_write_queue: Packet sending queue
* @sk_omem_alloc: "o" is "option" or "other"
* @sk_wmem_queued: persistent queue size
* @sk_forward_alloc: space allocated forward
* @sk_napi_id: id of the last napi context to receive data for sk
* @sk_ll_usec: usecs to busypoll when there is no data
* @sk_allocation: allocation mode
* @sk_pacing_rate: Pacing rate (if supported by transport/packet scheduler)
* @sk_pacing_status: Pacing status (requested, handled by sch_fq)
* @sk_max_pacing_rate: Maximum pacing rate (%SO_MAX_PACING_RATE)
* @sk_sndbuf: size of send buffer in bytes
* @__sk_flags_offset: empty field used to determine location of bitfield
* @sk_padding: unused element for alignment
* @sk_no_check_tx: %SO_NO_CHECK setting, set checksum in TX packets
* @sk_no_check_rx: allow zero checksum in RX packets
* @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO)
* @sk_route_nocaps: forbidden route capabilities (e.g NETIF_F_GSO_MASK)
* @sk_route_forced_caps: static, forced route capabilities
* (set in tcp_init_sock())
* @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4)
* @sk_gso_max_size: Maximum GSO segment size to build
* @sk_gso_max_segs: Maximum number of GSO segments
* @sk_pacing_shift: scaling factor for TCP Small Queues
* @sk_lingertime: %SO_LINGER l_linger setting
* @sk_backlog: always used with the per-socket spinlock held
* @sk_callback_lock: used with the callbacks in the end of this struct
* @sk_error_queue: rarely used
* @sk_prot_creator: sk_prot of original sock creator (see ipv6_setsockopt,
* IPV6_ADDRFORM for instance)
* @sk_err: last error
* @sk_err_soft: errors that don't cause failure but are the cause of a
* persistent failure not just 'timed out'
* @sk_drops: raw/udp drops counter
* @sk_ack_backlog: current listen backlog
* @sk_max_ack_backlog: listen backlog set in listen()
* @sk_uid: user id of owner
* @sk_priority: %SO_PRIORITY setting
* @sk_type: socket type (%SOCK_STREAM, etc)
* @sk_protocol: which protocol this socket belongs in this network family
* @sk_peer_pid: &struct pid for this socket's peer
* @sk_peer_cred: %SO_PEERCRED setting
* @sk_rcvlowat: %SO_RCVLOWAT setting
* @sk_rcvtimeo: %SO_RCVTIMEO setting
* @sk_sndtimeo: %SO_SNDTIMEO setting
* @sk_txhash: computed flow hash for use on transmit
* @sk_filter: socket filtering instructions
* @sk_timer: sock cleanup timer
* @sk_stamp: time stamp of last packet received
* @sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
* @sk_tsflags: SO_TIMESTAMPING socket options
* @sk_tskey: counter to disambiguate concurrent tstamp requests
* @sk_zckey: counter to order MSG_ZEROCOPY notifications
* @sk_socket: Identd and reporting IO signals
* @sk_user_data: RPC layer private data
* @sk_frag: cached page frag
* @sk_peek_off: current peek_offset value
* @sk_send_head: front of stuff to transmit
* @tcp_rtx_queue: TCP re-transmit queue [union with @sk_send_head]
* @sk_tx_skb_cache: cache copy of recently accessed TX skb
* @sk_security: used by security modules
* @sk_mark: generic packet mark
* @sk_cgrp_data: cgroup data for this cgroup
* @sk_memcg: this socket's memory cgroup association
* @sk_write_pending: a write to stream socket waits to start
* @sk_state_change: callback to indicate change in the state of the sock
* @sk_data_ready: callback to indicate there is data to be processed
* @sk_write_space: callback to indicate there is bf sending space available
* @sk_error_report: callback to indicate errors (e.g. %MSG_ERRQUEUE)
* @sk_backlog_rcv: callback to process the backlog
* @sk_validate_xmit_skb: ptr to an optional validate function
* @sk_destruct: called at sock freeing time, i.e. when all refcnt == 0
* @sk_reuseport_cb: reuseport group container
* @sk_bpf_storage: ptr to cache and control for bpf_sk_storage
* @sk_rcu: used during RCU grace period
* @sk_clockid: clockid used by time-based scheduling (SO_TXTIME)
* @sk_txtime_deadline_mode: set deadline mode for SO_TXTIME
* @sk_txtime_report_errors: set report errors mode for SO_TXTIME
* @sk_txtime_unused: unused txtime flags
*/
struct sock {
/*
* Now struct inet_timewait_sock also uses sock_common, so please just
* don't add nothing before this first member (__sk_common) --acme
*/
struct sock_common __sk_common;
#define sk_node __sk_common.skc_node
#define sk_nulls_node __sk_common.skc_nulls_node
#define sk_refcnt __sk_common.skc_refcnt
#define sk_tx_queue_mapping __sk_common.skc_tx_queue_mapping
#ifdef CONFIG_XPS
#define sk_rx_queue_mapping __sk_common.skc_rx_queue_mapping
#endif
#define sk_dontcopy_begin __sk_common.skc_dontcopy_begin
#define sk_dontcopy_end __sk_common.skc_dontcopy_end
#define sk_hash __sk_common.skc_hash
#define sk_portpair __sk_common.skc_portpair
#define sk_num __sk_common.skc_num
#define sk_dport __sk_common.skc_dport
#define sk_addrpair __sk_common.skc_addrpair
#define sk_daddr __sk_common.skc_daddr
#define sk_rcv_saddr __sk_common.skc_rcv_saddr
#define sk_family __sk_common.skc_family
#define sk_state __sk_common.skc_state
#define sk_reuse __sk_common.skc_reuse
#define sk_reuseport __sk_common.skc_reuseport
#define sk_ipv6only __sk_common.skc_ipv6only
#define sk_net_refcnt __sk_common.skc_net_refcnt
#define sk_bound_dev_if __sk_common.skc_bound_dev_if
#define sk_bind_node __sk_common.skc_bind_node
#define sk_prot __sk_common.skc_prot
#define sk_net __sk_common.skc_net
#define sk_v6_daddr __sk_common.skc_v6_daddr
#define sk_v6_rcv_saddr __sk_common.skc_v6_rcv_saddr
#define sk_cookie __sk_common.skc_cookie
#define sk_incoming_cpu __sk_common.skc_incoming_cpu
#define sk_flags __sk_common.skc_flags
#define sk_rxhash __sk_common.skc_rxhash
socket_lock_t sk_lock;
atomic_t sk_drops;
int sk_rcvlowat;
struct sk_buff_head sk_error_queue;
struct sk_buff *sk_rx_skb_cache;
struct sk_buff_head sk_receive_queue;
/*
* The backlog queue is special, it is always used with
* the per-socket spinlock held and requires low latency
* access. Therefore we special case it's implementation.
* Note : rmem_alloc is in this structure to fill a hole
* on 64bit arches, not because its logically part of
* backlog.
*/
struct {
atomic_t rmem_alloc;
int len;
struct sk_buff *head;
struct sk_buff *tail;
} sk_backlog;
#define sk_rmem_alloc sk_backlog.rmem_alloc
int sk_forward_alloc;
#ifdef CONFIG_NET_RX_BUSY_POLL
unsigned int sk_ll_usec;
/* ===== mostly read cache line ===== */
unsigned int sk_napi_id;
#endif
int sk_rcvbuf;
struct sk_filter __rcu *sk_filter;
union {
struct socket_wq __rcu *sk_wq;
/* private: */
struct socket_wq *sk_wq_raw;
/* public: */
};
#ifdef CONFIG_XFRM
struct xfrm_policy __rcu *sk_policy[2];
#endif
struct dst_entry *sk_rx_dst;
struct dst_entry __rcu *sk_dst_cache;
atomic_t sk_omem_alloc;
int sk_sndbuf;
/* ===== cache line for TX ===== */
int sk_wmem_queued;
refcount_t sk_wmem_alloc;
unsigned long sk_tsq_flags;
union {
struct sk_buff *sk_send_head;
struct rb_root tcp_rtx_queue;
};
struct sk_buff *sk_tx_skb_cache;
struct sk_buff_head sk_write_queue;
__s32 sk_peek_off;
int sk_write_pending;
__u32 sk_dst_pending_confirm;
u32 sk_pacing_status; /* see enum sk_pacing */
long sk_sndtimeo;
struct timer_list sk_timer;
__u32 sk_priority;
__u32 sk_mark;
unsigned long sk_pacing_rate; /* bytes per second */
unsigned long sk_max_pacing_rate;
struct page_frag sk_frag;
netdev_features_t sk_route_caps;
netdev_features_t sk_route_nocaps;
netdev_features_t sk_route_forced_caps;
int sk_gso_type;
unsigned int sk_gso_max_size;
gfp_t sk_allocation;
__u32 sk_txhash;
/*
* Because of non atomicity rules, all
* changes are protected by socket lock.
*/
u8 sk_padding : 1,
sk_kern_sock : 1,
sk_no_check_tx : 1,
sk_no_check_rx : 1,
sk_userlocks : 4;
u8 sk_pacing_shift;
u16 sk_type;
u16 sk_protocol;
u16 sk_gso_max_segs;
unsigned long sk_lingertime;
struct proto *sk_prot_creator;
rwlock_t sk_callback_lock;
int sk_err,
sk_err_soft;
u32 sk_ack_backlog;
u32 sk_max_ack_backlog;
kuid_t sk_uid;
struct pid *sk_peer_pid;
const struct cred *sk_peer_cred;
long sk_rcvtimeo;
ktime_t sk_stamp;
#if BITS_PER_LONG==32
seqlock_t sk_stamp_seq;
#endif
u16 sk_tsflags;
u8 sk_shutdown;
u32 sk_tskey;
atomic_t sk_zckey;
u8 sk_clockid;
u8 sk_txtime_deadline_mode : 1,
sk_txtime_report_errors : 1,
sk_txtime_unused : 6;
struct socket *sk_socket;
void *sk_user_data;
#ifdef CONFIG_SECURITY
void *sk_security;
#endif
struct sock_cgroup_data sk_cgrp_data;
struct mem_cgroup *sk_memcg;
void (*sk_state_change)(struct sock *sk);
void (*sk_data_ready)(struct sock *sk);
void (*sk_write_space)(struct sock *sk);
void (*sk_error_report)(struct sock *sk);
int (*sk_backlog_rcv)(struct sock *sk,
struct sk_buff *skb);
#ifdef CONFIG_SOCK_VALIDATE_XMIT
struct sk_buff* (*sk_validate_xmit_skb)(struct sock *sk,
struct net_device *dev,
struct sk_buff *skb);
#endif
void (*sk_destruct)(struct sock *sk);
struct sock_reuseport __rcu *sk_reuseport_cb;
#ifdef CONFIG_BPF_SYSCALL
struct bpf_sk_storage __rcu *sk_bpf_storage;
#endif
struct rcu_head sk_rcu;
};
enum sk_pacing {
SK_PACING_NONE = 0,
SK_PACING_NEEDED = 1,
SK_PACING_FQ = 2,
};
/* Pointer stored in sk_user_data might not be suitable for copying
* when cloning the socket. For instance, it can point to a reference
* counted object. sk_user_data bottom bit is set if pointer must not
* be copied.
*/
#define SK_USER_DATA_NOCOPY 1UL
#define SK_USER_DATA_PTRMASK ~(SK_USER_DATA_NOCOPY)
/**
* sk_user_data_is_nocopy - Test if sk_user_data pointer must not be copied
* @sk: socket
*/
static inline bool sk_user_data_is_nocopy(const struct sock *sk)
{
return ((uintptr_t)sk->sk_user_data & SK_USER_DATA_NOCOPY);
}
#define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
#define rcu_dereference_sk_user_data(sk) \
({ \
void *__tmp = rcu_dereference(__sk_user_data((sk))); \
(void *)((uintptr_t)__tmp & SK_USER_DATA_PTRMASK); \
})
#define rcu_assign_sk_user_data(sk, ptr) \
({ \
uintptr_t __tmp = (uintptr_t)(ptr); \
WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK); \
rcu_assign_pointer(__sk_user_data((sk)), __tmp); \
})
#define rcu_assign_sk_user_data_nocopy(sk, ptr) \
({ \
uintptr_t __tmp = (uintptr_t)(ptr); \
WARN_ON_ONCE(__tmp & ~SK_USER_DATA_PTRMASK); \
rcu_assign_pointer(__sk_user_data((sk)), \
__tmp | SK_USER_DATA_NOCOPY); \
})
/*
* SK_CAN_REUSE and SK_NO_REUSE on a socket mean that the socket is OK
* or not whether his port will be reused by someone else. SK_FORCE_REUSE
* on a socket means that the socket will reuse everybody else's port
* without looking at the other's sk_reuse value.
*/
#define SK_NO_REUSE 0
#define SK_CAN_REUSE 1
#define SK_FORCE_REUSE 2
int sk_set_peek_off(struct sock *sk, int val);
static inline int sk_peek_offset(struct sock *sk, int flags)
{
if (unlikely(flags & MSG_PEEK)) {
return READ_ONCE(sk->sk_peek_off);
}
return 0;
}
static inline void sk_peek_offset_bwd(struct sock *sk, int val)
{
s32 off = READ_ONCE(sk->sk_peek_off);
if (unlikely(off >= 0)) {
off = max_t(s32, off - val, 0);
WRITE_ONCE(sk->sk_peek_off, off);
}
}
static inline void sk_peek_offset_fwd(struct sock *sk, int val)
{
sk_peek_offset_bwd(sk, -val);
}
/*
* Hashed lists helper routines
*/
static inline struct sock *sk_entry(const struct hlist_node *node)
{
return hlist_entry(node, struct sock, sk_node);
}
static inline struct sock *__sk_head(const struct hlist_head *head)
{
return hlist_entry(head->first, struct sock, sk_node);
}
static inline struct sock *sk_head(const struct hlist_head *head)
{
return hlist_empty(head) ? NULL : __sk_head(head);
}
static inline struct sock *__sk_nulls_head(const struct hlist_nulls_head *head)
{
return hlist_nulls_entry(head->first, struct sock, sk_nulls_node);
}
static inline struct sock *sk_nulls_head(const struct hlist_nulls_head *head)
{
return hlist_nulls_empty(head) ? NULL : __sk_nulls_head(head);
}
static inline struct sock *sk_next(const struct sock *sk)
{
return hlist_entry_safe(sk->sk_node.next, struct sock, sk_node);
}
static inline struct sock *sk_nulls_next(const struct sock *sk)
{
return (!is_a_nulls(sk->sk_nulls_node.next)) ?
hlist_nulls_entry(sk->sk_nulls_node.next,
struct sock, sk_nulls_node) :
NULL;
}
static inline bool sk_unhashed(const struct sock *sk)
{
return hlist_unhashed(&sk->sk_node);
}
static inline bool sk_hashed(const struct sock *sk)
{
return !sk_unhashed(sk);
}
static inline void sk_node_init(struct hlist_node *node)
{
node->pprev = NULL;
}
static inline void sk_nulls_node_init(struct hlist_nulls_node *node)
{
node->pprev = NULL;
}
static inline void __sk_del_node(struct sock *sk)
{
__hlist_del(&sk->sk_node);
}
/* NB: equivalent to hlist_del_init_rcu */
static inline bool __sk_del_node_init(struct sock *sk)
{
if (sk_hashed(sk)) {
__sk_del_node(sk);
sk_node_init(&sk->sk_node);
return true;
}
return false;
}
/* Grab socket reference count. This operation is valid only
when sk is ALREADY grabbed f.e. it is found in hash table
or a list and the lookup is made under lock preventing hash table
modifications.
*/
static __always_inline void sock_hold(struct sock *sk)
{
refcount_inc(&sk->sk_refcnt);
}
/* Ungrab socket in the context, which assumes that socket refcnt
cannot hit zero, f.e. it is true in context of any socketcall.
*/
static __always_inline void __sock_put(struct sock *sk)
{
refcount_dec(&sk->sk_refcnt);
}
static inline bool sk_del_node_init(struct sock *sk)
{
bool rc = __sk_del_node_init(sk);
if (rc) {
/* paranoid for a while -acme */
WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
__sock_put(sk);
}
return rc;
}
#define sk_del_node_init_rcu(sk) sk_del_node_init(sk)
static inline bool __sk_nulls_del_node_init_rcu(struct sock *sk)
{
if (sk_hashed(sk)) {
hlist_nulls_del_init_rcu(&sk->sk_nulls_node);
return true;
}
return false;
}
static inline bool sk_nulls_del_node_init_rcu(struct sock *sk)
{
bool rc = __sk_nulls_del_node_init_rcu(sk);
if (rc) {
/* paranoid for a while -acme */
WARN_ON(refcount_read(&sk->sk_refcnt) == 1);
__sock_put(sk);
}
return rc;
}
static inline void __sk_add_node(struct sock *sk, struct hlist_head *list)
{
hlist_add_head(&sk->sk_node, list);
}
static inline void sk_add_node(struct sock *sk, struct hlist_head *list)
{
sock_hold(sk);
__sk_add_node(sk, list);
}
static inline void sk_add_node_rcu(struct sock *sk, struct hlist_head *list)
{
sock_hold(sk);
if (IS_ENABLED(CONFIG_IPV6) && sk->sk_reuseport &&
sk->sk_family == AF_INET6)
hlist_add_tail_rcu(&sk->sk_node, list);
else
hlist_add_head_rcu(&sk->sk_node, list);
}
static inline void sk_add_node_tail_rcu(struct sock *sk, struct hlist_head *list)
{
sock_hold(sk);
hlist_add_tail_rcu(&sk->sk_node, list);
}
static inline void __sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
{
hlist_nulls_add_head_rcu(&sk->sk_nulls_node, list);
}
static inline void __sk_nulls_add_node_tail_rcu(struct sock *sk, struct hlist_nulls_head *list)
{
hlist_nulls_add_tail_rcu(&sk->sk_nulls_node, list);
}
static inline void sk_nulls_add_node_rcu(struct sock *sk, struct hlist_nulls_head *list)
{
sock_hold(sk);
__sk_nulls_add_node_rcu(sk, list);
}
static inline void __sk_del_bind_node(struct sock *sk)
{
__hlist_del(&sk->sk_bind_node);
}
static inline void sk_add_bind_node(struct sock *sk,
struct hlist_head *list)
{
hlist_add_head(&sk->sk_bind_node, list);
}
#define sk_for_each(__sk, list) \
hlist_for_each_entry(__sk, list, sk_node)
#define sk_for_each_rcu(__sk, list) \
hlist_for_each_entry_rcu(__sk, list, sk_node)
#define sk_nulls_for_each(__sk, node, list) \
hlist_nulls_for_each_entry(__sk, node, list, sk_nulls_node)
#define sk_nulls_for_each_rcu(__sk, node, list) \
hlist_nulls_for_each_entry_rcu(__sk, node, list, sk_nulls_node)
#define sk_for_each_from(__sk) \
hlist_for_each_entry_from(__sk, sk_node)
#define sk_nulls_for_each_from(__sk, node) \
if (__sk && ({ node = &(__sk)->sk_nulls_node; 1; })) \
hlist_nulls_for_each_entry_from(__sk, node, sk_nulls_node)
#define sk_for_each_safe(__sk, tmp, list) \
hlist_for_each_entry_safe(__sk, tmp, list, sk_node)
#define sk_for_each_bound(__sk, list) \
hlist_for_each_entry(__sk, list, sk_bind_node)
/**
* sk_for_each_entry_offset_rcu - iterate over a list at a given struct offset
* @tpos: the type * to use as a loop cursor.
* @pos: the &struct hlist_node to use as a loop cursor.
* @head: the head for your list.
* @offset: offset of hlist_node within the struct.
*
*/
#define sk_for_each_entry_offset_rcu(tpos, pos, head, offset) \
for (pos = rcu_dereference(hlist_first_rcu(head)); \
pos != NULL && \
({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \
pos = rcu_dereference(hlist_next_rcu(pos)))
static inline struct user_namespace *sk_user_ns(struct sock *sk)
{
/* Careful only use this in a context where these parameters
* can not change and must all be valid, such as recvmsg from
* userspace.
*/
return sk->sk_socket->file->f_cred->user_ns;
}
/* Sock flags */
enum sock_flags {
SOCK_DEAD,
SOCK_DONE,
SOCK_URGINLINE,
SOCK_KEEPOPEN,
SOCK_LINGER,
SOCK_DESTROY,
SOCK_BROADCAST,
SOCK_TIMESTAMP,
SOCK_ZAPPED,
SOCK_USE_WRITE_QUEUE, /* whether to call sk->sk_write_space in sock_wfree */
SOCK_DBG, /* %SO_DEBUG setting */
SOCK_RCVTSTAMP, /* %SO_TIMESTAMP setting */
SOCK_RCVTSTAMPNS, /* %SO_TIMESTAMPNS setting */
SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
SOCK_MEMALLOC, /* VM depends on this socket for swapping */
SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */
SOCK_FASYNC, /* fasync() active */
SOCK_RXQ_OVFL,
SOCK_ZEROCOPY, /* buffers from userspace */
SOCK_WIFI_STATUS, /* push wifi status to userspace */
SOCK_NOFCS, /* Tell NIC not to do the Ethernet FCS.
* Will use last 4 bytes of packet sent from
* user-space instead.
*/
SOCK_FILTER_LOCKED, /* Filter cannot be changed anymore */
SOCK_SELECT_ERR_QUEUE, /* Wake select on error queue */
SOCK_RCU_FREE, /* wait rcu grace period in sk_destruct() */
SOCK_TXTIME,
SOCK_XDP, /* XDP is attached */
SOCK_TSTAMP_NEW, /* Indicates 64 bit timestamps always */
};
#define SK_FLAGS_TIMESTAMP ((1UL << SOCK_TIMESTAMP) | (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE))
static inline void sock_copy_flags(struct sock *nsk, struct sock *osk)
{
nsk->sk_flags = osk->sk_flags;
}
static inline void sock_set_flag(struct sock *sk, enum sock_flags flag)
{
__set_bit(flag, &sk->sk_flags);
}
static inline void sock_reset_flag(struct sock *sk, enum sock_flags flag)
{
__clear_bit(flag, &sk->sk_flags);
}
static inline bool sock_flag(const struct sock *sk, enum sock_flags flag)
{
return test_bit(flag, &sk->sk_flags);
}
#ifdef CONFIG_NET
DECLARE_STATIC_KEY_FALSE(memalloc_socks_key);
static inline int sk_memalloc_socks(void)
{
return static_branch_unlikely(&memalloc_socks_key);
}
#else
static inline int sk_memalloc_socks(void)
{
return 0;
}
#endif
static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask)
{
return gfp_mask | (sk->sk_allocation & __GFP_MEMALLOC);
}
static inline void sk_acceptq_removed(struct sock *sk)
{
WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog - 1);
}
static inline void sk_acceptq_added(struct sock *sk)
{
WRITE_ONCE(sk->sk_ack_backlog, sk->sk_ack_backlog + 1);
}
static inline bool sk_acceptq_is_full(const struct sock *sk)
{
return READ_ONCE(sk->sk_ack_backlog) > READ_ONCE(sk->sk_max_ack_backlog);
}
/*
* Compute minimal free write space needed to queue new packets.
*/
static inline int sk_stream_min_wspace(const struct sock *sk)
{
return READ_ONCE(sk->sk_wmem_queued) >> 1;
}
static inline int sk_stream_wspace(const struct sock *sk)
{
return READ_ONCE(sk->sk_sndbuf) - READ_ONCE(sk->sk_wmem_queued);
}
static inline void sk_wmem_queued_add(struct sock *sk, int val)
{
WRITE_ONCE(sk->sk_wmem_queued, sk->sk_wmem_queued + val);
}
void sk_stream_write_space(struct sock *sk);
/* OOB backlog add */
static inline void __sk_add_backlog(struct sock *sk, struct sk_buff *skb)
{
/* dont let skb dst not refcounted, we are going to leave rcu lock */
skb_dst_force(skb);
if (!sk->sk_backlog.tail)
WRITE_ONCE(sk->sk_backlog.head, skb);
else
sk->sk_backlog.tail->next = skb;
WRITE_ONCE(sk->sk_backlog.tail, skb);
skb->next = NULL;
}
/*
* Take into account size of receive queue and backlog queue
* Do not take into account this skb truesize,
* to allow even a single big packet to come.
*/
static inline bool sk_rcvqueues_full(const struct sock *sk, unsigned int limit)
{
unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc);
return qsize > limit;
}
/* The per-socket spinlock must be held here. */
static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb,
unsigned int limit)
{
if (sk_rcvqueues_full(sk, limit))
return -ENOBUFS;
/*
* If the skb was allocated from pfmemalloc reserves, only
* allow SOCK_MEMALLOC sockets to use it as this socket is
* helping free memory
*/
if (skb_pfmemalloc(skb) && !sock_flag(sk, SOCK_MEMALLOC))
return -ENOMEM;
__sk_add_backlog(sk, skb);
sk->sk_backlog.len += skb->truesize;
return 0;
}
int __sk_backlog_rcv(struct sock *sk, struct sk_buff *skb);
static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb)
{
if (sk_memalloc_socks() && skb_pfmemalloc(skb))
return __sk_backlog_rcv(sk, skb);
return sk->sk_backlog_rcv(sk, skb);
}
static inline void sk_incoming_cpu_update(struct sock *sk)
{