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781070551c
linux/include/net/sock.h
Martin KaFai Lau 6ac99e8f23 bpf: Introduce bpf sk local storage 
After allowing a bpf prog to
- directly read the skb->sk ptr
- get the fullsock bpf_sock by "bpf_sk_fullsock()"
- get the bpf_tcp_sock by "bpf_tcp_sock()"
- get the listener sock by "bpf_get_listener_sock()"
- avoid duplicating the fields of "(bpf_)sock" and "(bpf_)tcp_sock"
  into different bpf running context.

this patch is another effort to make bpf's network programming
more intuitive to do (together with memory and performance benefit).

When bpf prog needs to store data for a sk, the current practice is to
define a map with the usual 4-tuples (src/dst ip/port) as the key.
If multiple bpf progs require to store different sk data, multiple maps
have to be defined.  Hence, wasting memory to store the duplicated
keys (i.e. 4 tuples here) in each of the bpf map.
[ The smallest key could be the sk pointer itself which requires
  some enhancement in the verifier and it is a separate topic. ]

Also, the bpf prog needs to clean up the elem when sk is freed.
Otherwise, the bpf map will become full and un-usable quickly.
The sk-free tracking currently could be done during sk state
transition (e.g. BPF_SOCK_OPS_STATE_CB).

The size of the map needs to be predefined which then usually ended-up
with an over-provisioned map in production.  Even the map was re-sizable,
while the sk naturally come and go away already, this potential re-size
operation is arguably redundant if the data can be directly connected
to the sk itself instead of proxy-ing through a bpf map.

This patch introduces sk->sk_bpf_storage to provide local storage space
at sk for bpf prog to use.  The space will be allocated when the first bpf
prog has created data for this particular sk.

The design optimizes the bpf prog's lookup (and then optionally followed by
an inline update).  bpf_spin_lock should be used if the inline update needs
to be protected.

BPF_MAP_TYPE_SK_STORAGE:
-----------------------
To define a bpf "sk-local-storage", a BPF_MAP_TYPE_SK_STORAGE map (new in
this patch) needs to be created.  Multiple BPF_MAP_TYPE_SK_STORAGE maps can
be created to fit different bpf progs' needs.  The map enforces
BTF to allow printing the sk-local-storage during a system-wise
sk dump (e.g. "ss -ta") in the future.

The purpose of a BPF_MAP_TYPE_SK_STORAGE map is not for lookup/update/delete
a "sk-local-storage" data from a particular sk.
Think of the map as a meta-data (or "type") of a "sk-local-storage".  This
particular "type" of "sk-local-storage" data can then be stored in any sk.

The main purposes of this map are mostly:
1. Define the size of a "sk-local-storage" type.
2. Provide a similar syscall userspace API as the map (e.g. lookup/update,
   map-id, map-btf...etc.)
3. Keep track of all sk's storages of this "type" and clean them up
   when the map is freed.

sk->sk_bpf_storage:
------------------
The main lookup/update/delete is done on sk->sk_bpf_storage (which
is a "struct bpf_sk_storage").  When doing a lookup,
the "map" pointer is now used as the "key" to search on the
sk_storage->list.  The "map" pointer is actually serving
as the "type" of the "sk-local-storage" that is being
requested.

To allow very fast lookup, it should be as fast as looking up an
array at a stable-offset.  At the same time, it is not ideal to
set a hard limit on the number of sk-local-storage "type" that the
system can have.  Hence, this patch takes a cache approach.
The last search result from sk_storage->list is cached in
sk_storage->cache[] which is a stable sized array.  Each
"sk-local-storage" type has a stable offset to the cache[] array.
In the future, a map's flag could be introduced to do cache
opt-out/enforcement if it became necessary.

The cache size is 16 (i.e. 16 types of "sk-local-storage").
Programs can share map.  On the program side, having a few bpf_progs
running in the networking hotpath is already a lot.  The bpf_prog
should have already consolidated the existing sock-key-ed map usage
to minimize the map lookup penalty.  16 has enough runway to grow.

All sk-local-storage data will be removed from sk->sk_bpf_storage
during sk destruction.

bpf_sk_storage_get() and bpf_sk_storage_delete():
------------------------------------------------
Instead of using bpf_map_(lookup|update|delete)_elem(),
the bpf prog needs to use the new helper bpf_sk_storage_get() and
bpf_sk_storage_delete().  The verifier can then enforce the
ARG_PTR_TO_SOCKET argument.  The bpf_sk_storage_get() also allows to
"create" new elem if one does not exist in the sk.  It is done by
the new BPF_SK_STORAGE_GET_F_CREATE flag.  An optional value can also be
provided as the initial value during BPF_SK_STORAGE_GET_F_CREATE.
The BPF_MAP_TYPE_SK_STORAGE also supports bpf_spin_lock.  Together,
it has eliminated the potential use cases for an equivalent
bpf_map_update_elem() API (for bpf_prog) in this patch.

Misc notes:
----------
1. map_get_next_key is not supported.  From the userspace syscall
   perspective,  the map has the socket fd as the key while the map
   can be shared by pinned-file or map-id.

   Since btf is enforced, the existing "ss" could be enhanced to pretty
   print the local-storage.

   Supporting a kernel defined btf with 4 tuples as the return key could
   be explored later also.

2. The sk->sk_lock cannot be acquired.  Atomic operations is used instead.
   e.g. cmpxchg is done on the sk->sk_bpf_storage ptr.
   Please refer to the source code comments for the details in
   synchronization cases and considerations.

3. The mem is charged to the sk->sk_omem_alloc as the sk filter does.

Benchmark:
---------
Here is the benchmark data collected by turning on
the "kernel.bpf_stats_enabled" sysctl.
Two bpf progs are tested:

One bpf prog with the usual bpf hashmap (max_entries = 8192) with the
sk ptr as the key. (verifier is modified to support sk ptr as the key
That should have shortened the key lookup time.)

Another bpf prog is with the new BPF_MAP_TYPE_SK_STORAGE.

Both are storing a "u32 cnt", do a lookup on "egress_skb/cgroup" for
each egress skb and then bump the cnt.  netperf is used to drive
data with 4096 connected UDP sockets.

BPF_MAP_TYPE_HASH with a modifier verifier (152ns per bpf run)
27: cgroup_skb  name egress_sk_map  tag 74f56e832918070b run_time_ns 58280107540 run_cnt 381347633
    loaded_at 2019-04-15T13:46:39-0700  uid 0
    xlated 344B  jited 258B  memlock 4096B  map_ids 16
    btf_id 5

BPF_MAP_TYPE_SK_STORAGE in this patch (66ns per bpf run)
30: cgroup_skb  name egress_sk_stora  tag d4aa70984cc7bbf6 run_time_ns 25617093319 run_cnt 390989739
    loaded_at 2019-04-15T13:47:54-0700  uid 0
    xlated 168B  jited 156B  memlock 4096B  map_ids 17
    btf_id 6

Here is a high-level picture on how are the objects organized:

       sk
    ┌──────┐
    │      │
    │      │
    │      │
    │*sk_bpf_storage─────▶ bpf_sk_storage
    └──────┘                 ┌───────┐
                 ┌───────────┤ list  │
                 │           │       │
                 │           │       │
                 │           │       │
                 │           └───────┘
                 │
                 │     elem
                 │  ┌────────┐
                 ├─▶│ snode  │
                 │  ├────────┤
                 │  │  data  │          bpf_map
                 │  ├────────┤        ┌─────────┐
                 │  │map_node│◀─┬─────┤  list   │
                 │  └────────┘  │     │         │
                 │              │     │         │
                 │     elem     │     │         │
                 │  ┌────────┐  │     └─────────┘
                 └─▶│ snode  │  │
                    ├────────┤  │
   bpf_map          │  data  │  │
 ┌─────────┐        ├────────┤  │
 │  list   ├───────▶│map_node│  │
 │         │        └────────┘  │
 │         │                    │
 │         │           elem     │
 └─────────┘        ┌────────┐  │
                 ┌─▶│ snode  │  │
                 │  ├────────┤  │
                 │  │  data  │  │
                 │  ├────────┤  │
                 │  │map_node│◀─┘
                 │  └────────┘
                 │
                 │
                 │          ┌───────┐
     sk          └──────────│ list  │
  ┌──────┐                  │       │
  │      │                  │       │
  │      │                  │       │
  │      │                  └───────┘
  │*sk_bpf_storage───────▶bpf_sk_storage
  └──────┘

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-27 09:07:04 -07:00

2591 lines
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/*
* 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
*
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#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/smc.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_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_family: network address family
* @skc_state: Connection state
* @skc_reuse: %SO_REUSEADDR setting
* @skc_reuseport: %SO_REUSEPORT setting
* @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_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_incoming_cpu: record/match cpu processing incoming packets
* @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_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_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
* @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_destruct: called at sock freeing time, i.e. when all refcnt == 0
* @sk_reuseport_cb: reuseport group container
* @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_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;
struct socket_wq *sk_wq_raw;
};
#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.
*/
unsigned int __sk_flags_offset[0];
#ifdef __BIG_ENDIAN_BITFIELD
#define SK_FL_PROTO_SHIFT 16
#define SK_FL_PROTO_MASK 0x00ff0000
#define SK_FL_TYPE_SHIFT 0
#define SK_FL_TYPE_MASK 0x0000ffff
#else
#define SK_FL_PROTO_SHIFT 8
#define SK_FL_PROTO_MASK 0x0000ff00
#define SK_FL_TYPE_SHIFT 16
#define SK_FL_TYPE_MASK 0xffff0000
#endif
unsigned int sk_padding : 1,
sk_kern_sock : 1,
sk_no_check_tx : 1,
sk_no_check_rx : 1,
sk_userlocks : 4,
sk_protocol : 8,
sk_type : 16;
#define SK_PROTOCOL_MAX U8_MAX
u16 sk_gso_max_segs;
u8 sk_pacing_shift;
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,
};
#define __sk_user_data(sk) ((*((void __rcu **)&(sk)->sk_user_data)))
#define rcu_dereference_sk_user_data(sk) rcu_dereference(__sk_user_data((sk)))
#define rcu_assign_sk_user_data(sk, ptr) rcu_assign_pointer(__sk_user_data((sk)), ptr)
/*
* 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_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)
{
sk->sk_ack_backlog--;
}
static inline void sk_acceptq_added(struct sock *sk)
{
sk->sk_ack_backlog++;
}
static inline bool sk_acceptq_is_full(const struct sock *sk)
{
return sk->sk_ack_backlog > 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 sk->sk_wmem_queued >> 1;
}
static inline int sk_stream_wspace(const struct sock *sk)
{
return sk->sk_sndbuf - sk->sk_wmem_queued;
}
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)
sk->sk_backlog.head = skb;
else
sk->sk_backlog.tail->next = skb;
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)
{
int cpu = raw_smp_processor_id();
if (unlikely(sk->sk_incoming_cpu != cpu))
sk->sk_incoming_cpu = cpu;
}
static inline void sock_rps_record_flow_hash(__u32 hash)
{
#ifdef CONFIG_RPS
struct rps_sock_flow_table *sock_flow_table;
rcu_read_lock();
sock_flow_table = rcu_dereference(rps_sock_flow_table);
rps_record_sock_flow(sock_flow_table, hash);
rcu_read_unlock();
#endif
}
static inline void sock_rps_record_flow(const struct sock *sk)
{
#ifdef CONFIG_RPS
if (static_branch_unlikely(&rfs_needed)) {
/* Reading sk->sk_rxhash might incur an expensive cache line
* miss.
*
* TCP_ESTABLISHED does cover almost all states where RFS
* might be useful, and is cheaper [1] than testing :
* IPv4: inet_sk(sk)->inet_daddr
* IPv6: ipv6_addr_any(&sk->sk_v6_daddr)
* OR an additional socket flag
* [1] : sk_state and sk_prot are in the same cache line.
*/
if (sk->sk_state == TCP_ESTABLISHED)
sock_rps_record_flow_hash(sk->sk_rxhash);
}
#endif
}
static inline void sock_rps_save_rxhash(struct sock *sk,
const struct sk_buff *skb)
{
#ifdef CONFIG_RPS
if (unlikely(sk->sk_rxhash != skb->hash))
sk->sk_rxhash = skb->hash;
#endif
}
static inline void sock_rps_reset_rxhash(struct sock *sk)
{
#ifdef CONFIG_RPS
sk->sk_rxhash = 0;
#endif
}
#define sk_wait_event(__sk, __timeo, __condition, __wait) \
({ int __rc; \
release_sock(__sk); \
__rc = __condition; \
if (!__rc) { \
*(__timeo) = wait_woken(__wait, \
TASK_INTERRUPTIBLE, \
*(__timeo)); \
} \
sched_annotate_sleep(); \
lock_sock(__sk); \
__rc = __condition; \
__rc; \
})
int sk_stream_wait_connect(struct sock *sk, long *timeo_p);
int sk_stream_wait_memory(struct sock *sk, long *timeo_p);
void sk_stream_wait_close(struct sock *sk, long timeo_p);
int sk_stream_error(struct sock *sk, int flags, int err);
void sk_stream_kill_queues(struct sock *sk);
void sk_set_memalloc(struct sock *sk);
void sk_clear_memalloc(struct sock *sk);
void __sk_flush_backlog(struct sock *sk);
static inline bool sk_flush_backlog(struct sock *sk)
{
if (unlikely(READ_ONCE(sk->sk_backlog.tail))) {
__sk_flush_backlog(sk);
return true;
}
return false;
}
int sk_wait_data(struct sock *sk, long *timeo, const struct sk_buff *skb);
struct request_sock_ops;
struct timewait_sock_ops;
struct inet_hashinfo;
struct raw_hashinfo;
struct smc_hashinfo;
struct module;
/*
* caches using SLAB_TYPESAFE_BY_RCU should let .next pointer from nulls nodes
* un-modified. Special care is taken when initializing object to zero.
*/
static inline void sk_prot_clear_nulls(struct sock *sk, int size)
{
if (offsetof(struct sock, sk_node.next) != 0)
memset(sk, 0, offsetof(struct sock, sk_node.next));
memset(&sk->sk_node.pprev, 0,
size - offsetof(struct sock, sk_node.pprev));
}
/* Networking protocol blocks we attach to sockets.
* socket layer -> transport layer interface
*/
struct proto {
void (*close)(struct sock *sk,
long timeout);
int (*pre_connect)(struct sock *sk,
struct sockaddr *uaddr,
int addr_len);
int (*connect)(struct sock *sk,
struct sockaddr *uaddr,
int addr_len);
int (*disconnect)(struct sock *sk, int flags);
struct sock * (*accept)(struct sock *sk, int flags, int *err,
bool kern);
int (*ioctl)(struct sock *sk, int cmd,
unsigned long arg);
int (*init)(struct sock *sk);
void (*destroy)(struct sock *sk);
void (*shutdown)(struct sock *sk, int how);
int (*setsockopt)(struct sock *sk, int level,
int optname, char __user *optval,
unsigned int optlen);
int (*getsockopt)(struct sock *sk, int level,
int optname, char __user *optval,
int __user *option);
void (*keepalive)(struct sock *sk, int valbool);
#ifdef CONFIG_COMPAT
int (*compat_setsockopt)(struct sock *sk,
int level,
int optname, char __user *optval,
unsigned int optlen);
int (*compat_getsockopt)(struct sock *sk,
int level,
int optname, char __user *optval,
int __user *option);
int (*compat_ioctl)(struct sock *sk,
unsigned int cmd, unsigned long arg);
#endif
int (*sendmsg)(struct sock *sk, struct msghdr *msg,
size_t len);
int (*recvmsg)(struct sock *sk, struct msghdr *msg,
size_t len, int noblock, int flags,
int *addr_len);
int (*sendpage)(struct sock *sk, struct page *page,
int offset, size_t size, int flags);
int (*bind)(struct sock *sk,
struct sockaddr *uaddr, int addr_len);
int (*backlog_rcv) (struct sock *sk,
struct sk_buff *skb);
void (*release_cb)(struct sock *sk);
/* Keeping track of sk's, looking them up, and port selection methods. */
int (*hash)(struct sock *sk);
void (*unhash)(struct sock *sk);
void (*rehash)(struct sock *sk);
int (*get_port)(struct sock *sk, unsigned short snum);
/* Keeping track of sockets in use */
#ifdef CONFIG_PROC_FS
unsigned int inuse_idx;
#endif
bool (*stream_memory_free)(const struct sock *sk, int wake);
bool (*stream_memory_read)(const struct sock *sk);
/* Memory pressure */
void (*enter_memory_pressure)(struct sock *sk);
void (*leave_memory_pressure)(struct sock *sk);
atomic_long_t *memory_allocated; /* Current allocated memory. */
struct percpu_counter *sockets_allocated; /* Current number of sockets. */
/*
* Pressure flag: try to collapse.
* Technical note: it is used by multiple contexts non atomically.
* All the __sk_mem_schedule() is of this nature: accounting
* is strict, actions are advisory and have some latency.
*/
unsigned long *memory_pressure;
long *sysctl_mem;
int *sysctl_wmem;
int *sysctl_rmem;
u32 sysctl_wmem_offset;
u32 sysctl_rmem_offset;
int max_header;
bool no_autobind;
struct kmem_cache *slab;
unsigned int obj_size;
slab_flags_t slab_flags;
unsigned int useroffset; /* Usercopy region offset */
unsigned int usersize; /* Usercopy region size */
struct percpu_counter *orphan_count;
struct request_sock_ops *rsk_prot;
struct timewait_sock_ops *twsk_prot;
union {
struct inet_hashinfo *hashinfo;
struct udp_table *udp_table;
struct raw_hashinfo *raw_hash;
struct smc_hashinfo *smc_hash;
} h;
struct module *owner;
char name[32];
struct list_head node;
#ifdef SOCK_REFCNT_DEBUG
atomic_t socks;
#endif
int (*diag_destroy)(struct sock *sk, int err);
} __randomize_layout;
int proto_register(struct proto *prot, int alloc_slab);
void proto_unregister(struct proto *prot);
int sock_load_diag_module(int family, int protocol);
#ifdef SOCK_REFCNT_DEBUG
static inline void sk_refcnt_debug_inc(struct sock *sk)
{
atomic_inc(&sk->sk_prot->socks);
}
static inline void sk_refcnt_debug_dec(struct sock *sk)
{
atomic_dec(&sk->sk_prot->socks);
printk(KERN_DEBUG "%s socket %p released, %d are still alive\n",
sk->sk_prot->name, sk, atomic_read(&sk->sk_prot->socks));
}
static inline void sk_refcnt_debug_release(const struct sock *sk)
{
if (refcount_read(&sk->sk_refcnt) != 1)
printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n",
sk->sk_prot->name, sk, refcount_read(&sk->sk_refcnt));
}
#else /* SOCK_REFCNT_DEBUG */
#define sk_refcnt_debug_inc(sk) do { } while (0)
#define sk_refcnt_debug_dec(sk) do { } while (0)
#define sk_refcnt_debug_release(sk) do { } while (0)
#endif /* SOCK_REFCNT_DEBUG */
static inline bool __sk_stream_memory_free(const struct sock *sk, int wake)
{
if (sk->sk_wmem_queued >= sk->sk_sndbuf)
return false;
return sk->sk_prot->stream_memory_free ?
sk->sk_prot->stream_memory_free(sk, wake) : true;
}
static inline bool sk_stream_memory_free(const struct sock *sk)
{
return __sk_stream_memory_free(sk, 0);
}
static inline bool __sk_stream_is_writeable(const struct sock *sk, int wake)
{
return sk_stream_wspace(sk) >= sk_stream_min_wspace(sk) &&
__sk_stream_memory_free(sk, wake);
}
static inline bool sk_stream_is_writeable(const struct sock *sk)
{
return __sk_stream_is_writeable(sk, 0);
}
static inline int sk_under_cgroup_hierarchy(struct sock *sk,
struct cgroup *ancestor)
{
#ifdef CONFIG_SOCK_CGROUP_DATA
return cgroup_is_descendant(sock_cgroup_ptr(&sk->sk_cgrp_data),
ancestor);
#else
return -ENOTSUPP;
#endif
}
static inline bool sk_has_memory_pressure(const struct sock *sk)
{
return sk->sk_prot->memory_pressure != NULL;
}
static inline bool sk_under_memory_pressure(const struct sock *sk)
{
if (!sk->sk_prot->memory_pressure)
return false;
if (mem_cgroup_sockets_enabled && sk->sk_memcg &&
mem_cgroup_under_socket_pressure(sk->sk_memcg))
return true;
return !!*sk->sk_prot->memory_pressure;
}
static inline long
sk_memory_allocated(const struct sock *sk)
{
return atomic_long_read(sk->sk_prot->memory_allocated);
}
static inline long
sk_memory_allocated_add(struct sock *sk, int amt)
{
return atomic_long_add_return(amt, sk->sk_prot->memory_allocated);
}
static inline void
sk_memory_allocated_sub(struct sock *sk, int amt)
{
atomic_long_sub(amt, sk->sk_prot->memory_allocated);
}
static inline void sk_sockets_allocated_dec(struct sock *sk)
{
percpu_counter_dec(sk->sk_prot->sockets_allocated);
}
static inline void sk_sockets_allocated_inc(struct sock *sk)
{
percpu_counter_inc(sk->sk_prot->sockets_allocated);
}
static inline u64
sk_sockets_allocated_read_positive(struct sock *sk)
{
return percpu_counter_read_positive(sk->sk_prot->sockets_allocated);
}
static inline int
proto_sockets_allocated_sum_positive(struct proto *prot)
{
return percpu_counter_sum_positive(prot->sockets_allocated);
}
static inline long
proto_memory_allocated(struct proto *prot)
{
return atomic_long_read(prot->memory_allocated);
}
static inline bool
proto_memory_pressure(struct proto *prot)
{
if (!prot->memory_pressure)
return false;
return !!*prot->memory_pressure;
}
#ifdef CONFIG_PROC_FS
/* Called with local bh disabled */
void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc);
int sock_prot_inuse_get(struct net *net, struct proto *proto);
int sock_inuse_get(struct net *net);
#else
static inline void sock_prot_inuse_add(struct net *net, struct proto *prot,
int inc)
{
}
#endif
/* With per-bucket locks this operation is not-atomic, so that
* this version is not worse.
*/
static inline int __sk_prot_rehash(struct sock *sk)
{
sk->sk_prot->unhash(sk);
return sk->sk_prot->hash(sk);
}
/* About 10 seconds */
#define SOCK_DESTROY_TIME (10*HZ)
/* Sockets 0-1023 can't be bound to unless you are superuser */
#define PROT_SOCK 1024
#define SHUTDOWN_MASK 3
#define RCV_SHUTDOWN 1
#define SEND_SHUTDOWN 2
#define SOCK_SNDBUF_LOCK 1
#define SOCK_RCVBUF_LOCK 2
#define SOCK_BINDADDR_LOCK 4
#define SOCK_BINDPORT_LOCK 8
struct socket_alloc {
struct socket socket;
struct inode vfs_inode;
};
static inline struct socket *SOCKET_I(struct inode *inode)
{
return &container_of(inode, struct socket_alloc, vfs_inode)->socket;
}
static inline struct inode *SOCK_INODE(struct socket *socket)
{
return &container_of(socket, struct socket_alloc, socket)->vfs_inode;
}
/*
* Functions for memory accounting
*/
int __sk_mem_raise_allocated(struct sock *sk, int size, int amt, int kind);
int __sk_mem_schedule(struct sock *sk, int size, int kind);
void __sk_mem_reduce_allocated(struct sock *sk, int amount);
void __sk_mem_reclaim(struct sock *sk, int amount);
/* We used to have PAGE_SIZE here, but systems with 64KB pages
* do not necessarily have 16x time more memory than 4KB ones.
*/
#define SK_MEM_QUANTUM 4096
#define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM)
#define SK_MEM_SEND 0
#define SK_MEM_RECV 1
/* sysctl_mem values are in pages, we convert them in SK_MEM_QUANTUM units */
static inline long sk_prot_mem_limits(const struct sock *sk, int index)
{
long val = sk->sk_prot->sysctl_mem[index];
#if PAGE_SIZE > SK_MEM_QUANTUM
val <<= PAGE_SHIFT - SK_MEM_QUANTUM_SHIFT;
#elif PAGE_SIZE < SK_MEM_QUANTUM
val >>= SK_MEM_QUANTUM_SHIFT - PAGE_SHIFT;
#endif
return val;
}
static inline int sk_mem_pages(int amt)
{
return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT;
}
static inline bool sk_has_account(struct sock *sk)
{
/* return true if protocol supports memory accounting */
return !!sk->sk_prot->memory_allocated;
}
static inline bool sk_wmem_schedule(struct sock *sk, int size)
{
if (!sk_has_account(sk))
return true;
return size <= sk->sk_forward_alloc ||
__sk_mem_schedule(sk, size, SK_MEM_SEND);
}
static inline bool
sk_rmem_schedule(struct sock *sk, struct sk_buff *skb, int size)
{
if (!sk_has_account(sk))
return true;
return size<= sk->sk_forward_alloc ||
__sk_mem_schedule(sk, size, SK_MEM_RECV) ||
skb_pfmemalloc(skb);
}
static inline void sk_mem_reclaim(struct sock *sk)
{
if (!sk_has_account(sk))
return;
if (sk->sk_forward_alloc >= SK_MEM_QUANTUM)
__sk_mem_reclaim(sk, sk->sk_forward_alloc);
}
static inline void sk_mem_reclaim_partial(struct sock *sk)
{
if (!sk_has_account(sk))
return;
if (sk->sk_forward_alloc > SK_MEM_QUANTUM)
__sk_mem_reclaim(sk, sk->sk_forward_alloc - 1);
}
static inline void sk_mem_charge(struct sock *sk, int size)
{
if (!sk_has_account(sk))
return;
sk->sk_forward_alloc -= size;
}
static inline void sk_mem_uncharge(struct sock *sk, int size)
{
if (!sk_has_account(sk))
return;
sk->sk_forward_alloc += size;
/* Avoid a possible overflow.
* TCP send queues can make this happen, if sk_mem_reclaim()
* is not called and more than 2 GBytes are released at once.
*
* If we reach 2 MBytes, reclaim 1 MBytes right now, there is
* no need to hold that much forward allocation anyway.
*/
if (unlikely(sk->sk_forward_alloc >= 1 << 21))
__sk_mem_reclaim(sk, 1 << 20);
}
static inline void sk_wmem_free_skb(struct sock *sk, struct sk_buff *skb)
{
sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
sk->sk_wmem_queued -= skb->truesize;
sk_mem_uncharge(sk, skb->truesize);
if (!sk->sk_tx_skb_cache) {
skb_zcopy_clear(skb, true);
sk->sk_tx_skb_cache = skb;
return;
}
__kfree_skb(skb);
}
static inline void sock_release_ownership(struct sock *sk)
{
if (sk->sk_lock.owned) {
sk->sk_lock.owned = 0;
/* The sk_lock has mutex_unlock() semantics: */
mutex_release(&sk->sk_lock.dep_map, 1, _RET_IP_);
}
}
/*
* Macro so as to not evaluate some arguments when
* lockdep is not enabled.
*
* Mark both the sk_lock and the sk_lock.slock as a
* per-address-family lock class.
*/
#define sock_lock_init_class_and_name(sk, sname, skey, name, key) \
do { \
sk->sk_lock.owned = 0; \
init_waitqueue_head(&sk->sk_lock.wq); \
spin_lock_init(&(sk)->sk_lock.slock); \
debug_check_no_locks_freed((void *)&(sk)->sk_lock, \
sizeof((sk)->sk_lock)); \
lockdep_set_class_and_name(&(sk)->sk_lock.slock, \
(skey), (sname)); \
lockdep_init_map(&(sk)->sk_lock.dep_map, (name), (key), 0); \
} while (0)
#ifdef CONFIG_LOCKDEP
static inline bool lockdep_sock_is_held(const struct sock *sk)
{
return lockdep_is_held(&sk->sk_lock) ||
lockdep_is_held(&sk->sk_lock.slock);
}
#endif
void lock_sock_nested(struct sock *sk, int subclass);
static inline void lock_sock(struct sock *sk)
{
lock_sock_nested(sk, 0);
}
void __release_sock(struct sock *sk);
void release_sock(struct sock *sk);
/* BH context may only use the following locking interface. */
#define bh_lock_sock(__sk) spin_lock(&((__sk)->sk_lock.slock))
#define bh_lock_sock_nested(__sk) \
spin_lock_nested(&((__sk)->sk_lock.slock), \
SINGLE_DEPTH_NESTING)
#define bh_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
bool lock_sock_fast(struct sock *sk);
/**
* unlock_sock_fast - complement of lock_sock_fast
* @sk: socket
* @slow: slow mode
*
* fast unlock socket for user context.
* If slow mode is on, we call regular release_sock()
*/
static inline void unlock_sock_fast(struct sock *sk, bool slow)
{
if (slow)
release_sock(sk);
else
spin_unlock_bh(&sk->sk_lock.slock);
}
/* Used by processes to "lock" a socket state, so that
* interrupts and bottom half handlers won't change it
* from under us. It essentially blocks any incoming
* packets, so that we won't get any new data or any
* packets that change the state of the socket.
*
* While locked, BH processing will add new packets to
* the backlog queue. This queue is processed by the
* owner of the socket lock right before it is released.
*
* Since ~2.3.5 it is also exclusive sleep lock serializing
* accesses from user process context.
*/
static inline void sock_owned_by_me(const struct sock *sk)
{
#ifdef CONFIG_LOCKDEP
WARN_ON_ONCE(!lockdep_sock_is_held(sk) && debug_locks);
#endif
}
static inline bool sock_owned_by_user(const struct sock *sk)
{
sock_owned_by_me(sk);
return sk->sk_lock.owned;
}
static inline bool sock_owned_by_user_nocheck(const struct sock *sk)
{
return sk->sk_lock.owned;
}
/* no reclassification while locks are held */
static inline bool sock_allow_reclassification(const struct sock *csk)
{
struct sock *sk = (struct sock *)csk;
return !sk->sk_lock.owned && !spin_is_locked(&sk->sk_lock.slock);
}
struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
struct proto *prot, int kern);
void sk_free(struct sock *sk);
void sk_destruct(struct sock *sk);
struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority);
void sk_free_unlock_clone(struct sock *sk);
struct sk_buff *sock_wmalloc(struct sock *sk, unsigned long size, int force,
gfp_t priority);
void __sock_wfree(struct sk_buff *skb);
void sock_wfree(struct sk_buff *skb);
struct sk_buff *sock_omalloc(struct sock *sk, unsigned long size,
gfp_t priority);
void skb_orphan_partial(struct sk_buff *skb);
void sock_rfree(struct sk_buff *skb);
void sock_efree(struct sk_buff *skb);
#ifdef CONFIG_INET
void sock_edemux(struct sk_buff *skb);
#else
#define sock_edemux sock_efree
#endif
int sock_setsockopt(struct socket *sock, int level, int op,
char __user *optval, unsigned int optlen);
int sock_getsockopt(struct socket *sock, int level, int op,
char __user *optval, int __user *optlen);
int sock_gettstamp(struct socket *sock, void __user *userstamp,
bool timeval, bool time32);
struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size,
int noblock, int *errcode);
struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len,
unsigned long data_len, int noblock,
int *errcode, int max_page_order);
void *sock_kmalloc(struct sock *sk, int size, gfp_t priority);
void sock_kfree_s(struct sock *sk, void *mem, int size);
void sock_kzfree_s(struct sock *sk, void *mem, int size);
void sk_send_sigurg(struct sock *sk);
struct sockcm_cookie {
u64 transmit_time;
u32 mark;
u16 tsflags;
};
static inline void sockcm_init(struct sockcm_cookie *sockc,
const struct sock *sk)
{
*sockc = (struct sockcm_cookie) { .tsflags = sk->sk_tsflags };
}
int __sock_cmsg_send(struct sock *sk, struct msghdr *msg, struct cmsghdr *cmsg,
struct sockcm_cookie *sockc);
int sock_cmsg_send(struct sock *sk, struct msghdr *msg,
struct sockcm_cookie *sockc);
/*
* Functions to fill in entries in struct proto_ops when a protocol
* does not implement a particular function.
*/
int sock_no_bind(struct socket *, struct sockaddr *, int);
int sock_no_connect(struct socket *, struct sockaddr *, int, int);
int sock_no_socketpair(struct socket *, struct socket *);
int sock_no_accept(struct socket *, struct socket *, int, bool);
int sock_no_getname(struct socket *, struct sockaddr *, int);
int sock_no_ioctl(struct socket *, unsigned int, unsigned long);
int sock_no_listen(struct socket *, int);
int sock_no_shutdown(struct socket *, int);
int sock_no_getsockopt(struct socket *, int , int, char __user *, int __user *);
int sock_no_setsockopt(struct socket *, int, int, char __user *, unsigned int);
int sock_no_sendmsg(struct socket *, struct msghdr *, size_t);
int sock_no_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t len);
int sock_no_recvmsg(struct socket *, struct msghdr *, size_t, int);
int sock_no_mmap(struct file *file, struct socket *sock,
struct vm_area_struct *vma);
ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset,
size_t size, int flags);
ssize_t sock_no_sendpage_locked(struct sock *sk, struct page *page,
int offset, size_t size, int flags);
/*
* Functions to fill in entries in struct proto_ops when a protocol
* uses the inet style.
*/
int sock_common_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen);
int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
int flags);
int sock_common_setsockopt(struct socket *sock, int level, int optname,
char __user *optval, unsigned int optlen);
int compat_sock_common_getsockopt(struct socket *sock, int level,
int optname, char __user *optval, int __user *optlen);
int compat_sock_common_setsockopt(struct socket *sock, int level,
int optname, char __user *optval, unsigned int optlen);
void sk_common_release(struct sock *sk);
/*
* Default socket callbacks and setup code
*/
/* Initialise core socket variables */
void sock_init_data(struct socket *sock, struct sock *sk);
/*
* Socket reference counting postulates.
*
* * Each user of socket SHOULD hold a reference count.
* * Each access point to socket (an hash table bucket, reference from a list,
* running timer, skb in flight MUST hold a reference count.
* * When reference count hits 0, it means it will never increase back.
* * When reference count hits 0, it means that no references from
* outside exist to this socket and current process on current CPU
* is last user and may/should destroy this socket.
* * sk_free is called from any context: process, BH, IRQ. When
* it is called, socket has no references from outside -> sk_free
* may release descendant resources allocated by the socket, but
* to the time when it is called, socket is NOT referenced by any
* hash tables, lists etc.
* * Packets, delivered from outside (from network or from another process)
* and enqueued on receive/error queues SHOULD NOT grab reference count,
* when they sit in queue. Otherwise, packets will leak to hole, when
* socket is looked up by one cpu and unhasing is made by another CPU.
* It is true for udp/raw, netlink (leak to receive and error queues), tcp
* (leak to backlog). Packet socket does all the processing inside
* BR_NETPROTO_LOCK, so that it has not this race condition. UNIX sockets
* use separate SMP lock, so that they are prone too.
*/
/* Ungrab socket and destroy it, if it was the last reference. */
static inline void sock_put(struct sock *sk)
{
if (refcount_dec_and_test(&sk->sk_refcnt))
sk_free(sk);
}
/* Generic version of sock_put(), dealing with all sockets
* (TCP_TIMEWAIT, TCP_NEW_SYN_RECV, ESTABLISHED...)
*/
void sock_gen_put(struct sock *sk);
int __sk_receive_skb(struct sock *sk, struct sk_buff *skb, const int nested,
unsigned int trim_cap, bool refcounted);
static inline int sk_receive_skb(struct sock *sk, struct sk_buff *skb,
const int nested)
{
return __sk_receive_skb(sk, skb, nested, 1, true);
}
static inline void sk_tx_queue_set(struct sock *sk, int tx_queue)
{
/* sk_tx_queue_mapping accept only upto a 16-bit value */
if (WARN_ON_ONCE((unsigned short)tx_queue >= USHRT_MAX))
return;
sk->sk_tx_queue_mapping = tx_queue;
}
#define NO_QUEUE_MAPPING USHRT_MAX
static inline void sk_tx_queue_clear(struct sock *sk)
{
sk->sk_tx_queue_mapping = NO_QUEUE_MAPPING;
}
static inline int sk_tx_queue_get(const struct sock *sk)
{
if (sk && sk->sk_tx_queue_mapping != NO_QUEUE_MAPPING)
return sk->sk_tx_queue_mapping;
return -1;
}
static inline void sk_rx_queue_set(struct sock *sk, const struct sk_buff *skb)
{
#ifdef CONFIG_XPS
if (skb_rx_queue_recorded(skb)) {
u16 rx_queue = skb_get_rx_queue(skb);
if (WARN_ON_ONCE(rx_queue == NO_QUEUE_MAPPING))
return;
sk->sk_rx_queue_mapping = rx_queue;
}
#endif
}
static inline void sk_rx_queue_clear(struct sock *sk)
{
#ifdef CONFIG_XPS
sk->sk_rx_queue_mapping = NO_QUEUE_MAPPING;
#endif
}
#ifdef CONFIG_XPS
static inline int sk_rx_queue_get(const struct sock *sk)
{
if (sk && sk->sk_rx_queue_mapping != NO_QUEUE_MAPPING)
return sk->sk_rx_queue_mapping;
return -1;
}
#endif
static inline void sk_set_socket(struct sock *sk, struct socket *sock)
{
sk_tx_queue_clear(sk);
sk->sk_socket = sock;
}
static inline wait_queue_head_t *sk_sleep(struct sock *sk)
{
BUILD_BUG_ON(offsetof(struct socket_wq, wait) != 0);
return &rcu_dereference_raw(sk->sk_wq)->wait;
}
/* Detach socket from process context.
* Announce socket dead, detach it from wait queue and inode.
* Note that parent inode held reference count on this struct sock,
* we do not release it in this function, because protocol
* probably wants some additional cleanups or even continuing
* to work with this socket (TCP).
*/
static inline void sock_orphan(struct sock *sk)
{
write_lock_bh(&sk->sk_callback_lock);
sock_set_flag(sk, SOCK_DEAD);
sk_set_socket(sk, NULL);
sk->sk_wq = NULL;
write_unlock_bh(&sk->sk_callback_lock);
}
static inline void sock_graft(struct sock *sk, struct socket *parent)
{
WARN_ON(parent->sk);
write_lock_bh(&sk->sk_callback_lock);
rcu_assign_pointer(sk->sk_wq, parent->wq);
parent->sk = sk;
sk_set_socket(sk, parent);
sk->sk_uid = SOCK_INODE(parent)->i_uid;
security_sock_graft(sk, parent);
write_unlock_bh(&sk->sk_callback_lock);
}
kuid_t sock_i_uid(struct sock *sk);
unsigned long sock_i_ino(struct sock *sk);
static inline kuid_t sock_net_uid(const struct net *net, const struct sock *sk)
{
return sk ? sk->sk_uid : make_kuid(net->user_ns, 0);
}
static inline u32 net_tx_rndhash(void)
{
u32 v = prandom_u32();
return v ?: 1;
}
static inline void sk_set_txhash(struct sock *sk)
{
sk->sk_txhash = net_tx_rndhash();
}
static inline void sk_rethink_txhash(struct sock *sk)
{
if (sk->sk_txhash)
sk_set_txhash(sk);
}
static inline struct dst_entry *
__sk_dst_get(struct sock *sk)
{
return rcu_dereference_check(sk->sk_dst_cache,
lockdep_sock_is_held(sk));
}
static inline struct dst_entry *
sk_dst_get(struct sock *sk)
{
struct dst_entry *dst;
rcu_read_lock();
dst = rcu_dereference(sk->sk_dst_cache);
if (dst && !atomic_inc_not_zero(&dst->__refcnt))
dst = NULL;
rcu_read_unlock();
return dst;
}
static inline void dst_negative_advice(struct sock *sk)
{
struct dst_entry *ndst, *dst = __sk_dst_get(sk);
sk_rethink_txhash(sk);
if (dst && dst->ops->negative_advice) {
ndst = dst->ops->negative_advice(dst);
if (ndst != dst) {
rcu_assign_pointer(sk->sk_dst_cache, ndst);
sk_tx_queue_clear(sk);
sk->sk_dst_pending_confirm = 0;
}
}
}
static inline void
__sk_dst_set(struct sock *sk, struct dst_entry *dst)
{
struct dst_entry *old_dst;
sk_tx_queue_clear(sk);
sk->sk_dst_pending_confirm = 0;
old_dst = rcu_dereference_protected(sk->sk_dst_cache,
lockdep_sock_is_held(sk));
rcu_assign_pointer(sk->sk_dst_cache, dst);
dst_release(old_dst);
}
static inline void
sk_dst_set(struct sock *sk, struct dst_entry *dst)
{
struct dst_entry *old_dst;
sk_tx_queue_clear(sk);
sk->sk_dst_pending_confirm = 0;
old_dst = xchg((__force struct dst_entry **)&sk->sk_dst_cache, dst);
dst_release(old_dst);
}
static inline void
__sk_dst_reset(struct sock *sk)
{
__sk_dst_set(sk, NULL);
}
static inline void
sk_dst_reset(struct sock *sk)
{
sk_dst_set(sk, NULL);
}
struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie);
struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie);
static inline void sk_dst_confirm(struct sock *sk)
{
if (!sk->sk_dst_pending_confirm)
sk->sk_dst_pending_confirm = 1;
}
static inline void sock_confirm_neigh(struct sk_buff *skb, struct neighbour *n)
{
if (skb_get_dst_pending_confirm(skb)) {
struct sock *sk = skb->sk;
unsigned long now = jiffies;
/* avoid dirtying neighbour */
if (n->confirmed != now)
n->confirmed = now;
if (sk && sk->sk_dst_pending_confirm)
sk->sk_dst_pending_confirm = 0;
}
}
bool sk_mc_loop(struct sock *sk);
static inline bool sk_can_gso(const struct sock *sk)
{
return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type);
}
void sk_setup_caps(struct sock *sk, struct dst_entry *dst);
static inline void sk_nocaps_add(struct sock *sk, netdev_features_t flags)
{
sk->sk_route_nocaps |= flags;
sk->sk_route_caps &= ~flags;
}
static inline int skb_do_copy_data_nocache(struct sock *sk, struct sk_buff *skb,
struct iov_iter *from, char *to,
int copy, int offset)
{
if (skb->ip_summed == CHECKSUM_NONE) {
__wsum csum = 0;
if (!csum_and_copy_from_iter_full(to, copy, &csum, from))
return -EFAULT;
skb->csum = csum_block_add(skb->csum, csum, offset);
} else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) {
if (!copy_from_iter_full_nocache(to, copy, from))
return -EFAULT;
} else if (!copy_from_iter_full(to, copy, from))
return -EFAULT;
return 0;
}
static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb,
struct iov_iter *from, int copy)
{
int err, offset = skb->len;
err = skb_do_copy_data_nocache(sk, skb, from, skb_put(skb, copy),
copy, offset);
if (err)
__skb_trim(skb, offset);
return err;
}
static inline int skb_copy_to_page_nocache(struct sock *sk, struct iov_iter *from,
struct sk_buff *skb,
struct page *page,
int off, int copy)
{
int err;
err = skb_do_copy_data_nocache(sk, skb, from, page_address(page) + off,
copy, skb->len);
if (err)
return err;
skb->len += copy;
skb->data_len += copy;
skb->truesize += copy;
sk->sk_wmem_queued += copy;
sk_mem_charge(sk, copy);
return 0;
}
/**
* sk_wmem_alloc_get - returns write allocations
* @sk: socket
*
* Returns sk_wmem_alloc minus initial offset of one
*/
static inline int sk_wmem_alloc_get(const struct sock *sk)
{
return refcount_read(&sk->sk_wmem_alloc) - 1;
}
/**
* sk_rmem_alloc_get - returns read allocations
* @sk: socket
*
* Returns sk_rmem_alloc
*/
static inline int sk_rmem_alloc_get(const struct sock *sk)
{
return atomic_read(&sk->sk_rmem_alloc);
}
/**
* sk_has_allocations - check if allocations are outstanding
* @sk: socket
*
* Returns true if socket has write or read allocations
*/
static inline bool sk_has_allocations(const struct sock *sk)
{
return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk);
}
/**
* skwq_has_sleeper - check if there are any waiting processes
* @wq: struct socket_wq
*
* Returns true if socket_wq has waiting processes
*
* The purpose of the skwq_has_sleeper and sock_poll_wait is to wrap the memory
* barrier call. They were added due to the race found within the tcp code.
*
* Consider following tcp code paths::
*
* CPU1 CPU2
* sys_select receive packet
* ... ...
* __add_wait_queue update tp->rcv_nxt
* ... ...
* tp->rcv_nxt check sock_def_readable
* ... {
* schedule rcu_read_lock();
* wq = rcu_dereference(sk->sk_wq);
* if (wq && waitqueue_active(&wq->wait))
* wake_up_interruptible(&wq->wait)
* ...
* }
*
* The race for tcp fires when the __add_wait_queue changes done by CPU1 stay
* in its cache, and so does the tp->rcv_nxt update on CPU2 side. The CPU1
* could then endup calling schedule and sleep forever if there are no more
* data on the socket.
*
*/
static inline bool skwq_has_sleeper(struct socket_wq *wq)
{
return wq && wq_has_sleeper(&wq->wait);
}
/**
* sock_poll_wait - place memory barrier behind the poll_wait call.
* @filp: file
* @sock: socket to wait on
* @p: poll_table
*
* See the comments in the wq_has_sleeper function.
*/
static inline void sock_poll_wait(struct file *filp, struct socket *sock,
poll_table *p)
{
if (!poll_does_not_wait(p)) {
poll_wait(filp, &sock->wq->wait, p);
/* We need to be sure we are in sync with the
* socket flags modification.
*
* This memory barrier is paired in the wq_has_sleeper.
*/
smp_mb();
}
}
static inline void skb_set_hash_from_sk(struct sk_buff *skb, struct sock *sk)
{
if (sk->sk_txhash) {
skb->l4_hash = 1;
skb->hash = sk->sk_txhash;
}
}
void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
/*
* Queue a received datagram if it will fit. Stream and sequenced
* protocols can't normally use this as they need to fit buffers in
* and play with them.
*
* Inlined as it's very short and called for pretty much every
* packet ever received.
*/
static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
{
skb_orphan(skb);
skb->sk = sk;
skb->destructor = sock_rfree;
atomic_add(skb->truesize, &sk->sk_rmem_alloc);
sk_mem_charge(sk, skb->truesize);
}
void sk_reset_timer(struct sock *sk, struct timer_list *timer,
unsigned long expires);
void sk_stop_timer(struct sock *sk, struct timer_list *timer);
int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
struct sk_buff *skb, unsigned int flags,
void (*destructor)(struct sock *sk,
struct sk_buff *skb));
int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
/*
* Recover an error report and clear atomically
*/
static inline int sock_error(struct sock *sk)
{
int err;
if (likely(!sk->sk_err))
return 0;
err = xchg(&sk->sk_err, 0);
return -err;
}
static inline unsigned long sock_wspace(struct sock *sk)
{
int amt = 0;
if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
amt = sk->sk_sndbuf - refcount_read(&sk->sk_wmem_alloc);
if (amt < 0)
amt = 0;
}
return amt;
}
/* Note:
* We use sk->sk_wq_raw, from contexts knowing this
* pointer is not NULL and cannot disappear/change.
*/
static inline void sk_set_bit(int nr, struct sock *sk)
{
if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
!sock_flag(sk, SOCK_FASYNC))
return;
set_bit(nr, &sk->sk_wq_raw->flags);
}
static inline void sk_clear_bit(int nr, struct sock *sk)
{
if ((nr == SOCKWQ_ASYNC_NOSPACE || nr == SOCKWQ_ASYNC_WAITDATA) &&
!sock_flag(sk, SOCK_FASYNC))
return;
clear_bit(nr, &sk->sk_wq_raw->flags);
}
static inline void sk_wake_async(const struct sock *sk, int how, int band)
{
if (sock_flag(sk, SOCK_FASYNC)) {
rcu_read_lock();
sock_wake_async(rcu_dereference(sk->sk_wq), how, band);
rcu_read_unlock();
}
}
/* Since sk_{r,w}mem_alloc sums skb->truesize, even a small frame might
* need sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak.
* Note: for send buffers, TCP works better if we can build two skbs at
* minimum.
*/
#define TCP_SKB_MIN_TRUESIZE (2048 + SKB_DATA_ALIGN(sizeof(struct sk_buff)))
#define SOCK_MIN_SNDBUF (TCP_SKB_MIN_TRUESIZE * 2)
#define SOCK_MIN_RCVBUF TCP_SKB_MIN_TRUESIZE
static inline void sk_stream_moderate_sndbuf(struct sock *sk)
{
if (!(sk->sk_userlocks & SOCK_SNDBUF_LOCK)) {
sk->sk_sndbuf = min(sk->sk_sndbuf, sk->sk_wmem_queued >> 1);
sk->sk_sndbuf = max_t(u32, sk->sk_sndbuf, SOCK_MIN_SNDBUF);
}
}
struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
bool force_schedule);
/**
* sk_page_frag - return an appropriate page_frag
* @sk: socket
*
* If socket allocation mode allows current thread to sleep, it means its
* safe to use the per task page_frag instead of the per socket one.
*/
static inline struct page_frag *sk_page_frag(struct sock *sk)
{
if (gfpflags_allow_blocking(sk->sk_allocation))
return &current->task_frag;
return &sk->sk_frag;
}
bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag);
/*
* Default write policy as shown to user space via poll/select/SIGIO
*/
static inline bool sock_writeable(const struct sock *sk)
{
return refcount_read(&sk->sk_wmem_alloc) < (sk->sk_sndbuf >> 1);
}
static inline gfp_t gfp_any(void)
{
return in_softirq() ? GFP_ATOMIC : GFP_KERNEL;
}
static inline long sock_rcvtimeo(const struct sock *sk, bool noblock)
{
return noblock ? 0 : sk->sk_rcvtimeo;
}
static inline long sock_sndtimeo(const struct sock *sk, bool noblock)
{
return noblock ? 0 : sk->sk_sndtimeo;
}
static inline int sock_rcvlowat(const struct sock *sk, int waitall, int len)
{
return (waitall ? len : min_t(int, sk->sk_rcvlowat, len)) ? : 1;
}
/* Alas, with timeout socket operations are not restartable.
* Compare this to poll().
*/
static inline int sock_intr_errno(long timeo)
{
return timeo == MAX_SCHEDULE_TIMEOUT ? -ERESTARTSYS : -EINTR;
}
struct sock_skb_cb {
u32 dropcount;
};
/* Store sock_skb_cb at the end of skb->cb[] so protocol families
* using skb->cb[] would keep using it directly and utilize its
* alignement guarantee.
*/
#define SOCK_SKB_CB_OFFSET ((FIELD_SIZEOF(struct sk_buff, cb) - \
sizeof(struct sock_skb_cb)))
#define SOCK_SKB_CB(__skb) ((struct sock_skb_cb *)((__skb)->cb + \
SOCK_SKB_CB_OFFSET))
#define sock_skb_cb_check_size(size) \
BUILD_BUG_ON((size) > SOCK_SKB_CB_OFFSET)
static inline void
sock_skb_set_dropcount(const struct sock *sk, struct sk_buff *skb)
{
SOCK_SKB_CB(skb)->dropcount = sock_flag(sk, SOCK_RXQ_OVFL) ?
atomic_read(&sk->sk_drops) : 0;
}
static inline void sk_drops_add(struct sock *sk, const struct sk_buff *skb)
{
int segs = max_t(u16, 1, skb_shinfo(skb)->gso_segs);
atomic_add(segs, &sk->sk_drops);
}
static inline ktime_t sock_read_timestamp(struct sock *sk)
{
#if BITS_PER_LONG==32
unsigned int seq;
ktime_t kt;
do {
seq = read_seqbegin(&sk->sk_stamp_seq);
kt = sk->sk_stamp;
} while (read_seqretry(&sk->sk_stamp_seq, seq));
return kt;
#else
return sk->sk_stamp;
#endif
}
static inline void sock_write_timestamp(struct sock *sk, ktime_t kt)
{
#if BITS_PER_LONG==32
write_seqlock(&sk->sk_stamp_seq);
sk->sk_stamp = kt;
write_sequnlock(&sk->sk_stamp_seq);
#else
sk->sk_stamp = kt;
#endif
}
void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
struct sk_buff *skb);
void __sock_recv_wifi_status(struct msghdr *msg, struct sock *sk,
struct sk_buff *skb);
static inline void
sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
{
ktime_t kt = skb->tstamp;
struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
/*
* generate control messages if
* - receive time stamping in software requested
* - software time stamp available and wanted
* - hardware time stamps available and wanted
*/
if (sock_flag(sk, SOCK_RCVTSTAMP) ||
(sk->sk_tsflags & SOF_TIMESTAMPING_RX_SOFTWARE) ||
(kt && sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE) ||
(hwtstamps->hwtstamp &&
(sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)))
__sock_recv_timestamp(msg, sk, skb);
else
sock_write_timestamp(sk, kt);
if (sock_flag(sk, SOCK_WIFI_STATUS) && skb->wifi_acked_valid)
__sock_recv_wifi_status(msg, sk, skb);
}
void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
struct sk_buff *skb);
#define SK_DEFAULT_STAMP (-1L * NSEC_PER_SEC)
static inline void sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk,
struct sk_buff *skb)
{
#define FLAGS_TS_OR_DROPS ((1UL << SOCK_RXQ_OVFL) | \
(1UL << SOCK_RCVTSTAMP))
#define TSFLAGS_ANY (SOF_TIMESTAMPING_SOFTWARE | \
SOF_TIMESTAMPING_RAW_HARDWARE)
if (sk->sk_flags & FLAGS_TS_OR_DROPS || sk->sk_tsflags & TSFLAGS_ANY)
__sock_recv_ts_and_drops(msg, sk, skb);
else if (unlikely(sock_flag(sk, SOCK_TIMESTAMP)))
sock_write_timestamp(sk, skb->tstamp);
else if (unlikely(sk->sk_stamp == SK_DEFAULT_STAMP))
sock_write_timestamp(sk, 0);
}
void __sock_tx_timestamp(__u16 tsflags, __u8 *tx_flags);
/**
* _sock_tx_timestamp - checks whether the outgoing packet is to be time stamped
* @sk: socket sending this packet
* @tsflags: timestamping flags to use
* @tx_flags: completed with instructions for time stamping
* @tskey: filled in with next sk_tskey (not for TCP, which uses seqno)
*
* Note: callers should take care of initial ``*tx_flags`` value (usually 0)
*/
static inline void _sock_tx_timestamp(struct sock *sk, __u16 tsflags,
__u8 *tx_flags, __u32 *tskey)
{
if (unlikely(tsflags)) {
__sock_tx_timestamp(tsflags, tx_flags);
if (tsflags & SOF_TIMESTAMPING_OPT_ID && tskey &&
tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
*tskey = sk->sk_tskey++;
}
if (unlikely(sock_flag(sk, SOCK_WIFI_STATUS)))
*tx_flags |= SKBTX_WIFI_STATUS;
}
static inline void sock_tx_timestamp(struct sock *sk, __u16 tsflags,
__u8 *tx_flags)
{
_sock_tx_timestamp(sk, tsflags, tx_flags, NULL);
}
static inline void skb_setup_tx_timestamp(struct sk_buff *skb, __u16 tsflags)
{
_sock_tx_timestamp(skb->sk, tsflags, &skb_shinfo(skb)->tx_flags,
&skb_shinfo(skb)->tskey);
}
/**
* sk_eat_skb - Release a skb if it is no longer needed
* @sk: socket to eat this skb from
* @skb: socket buffer to eat
*
* This routine must be called with interrupts disabled or with the socket
* locked so that the sk_buff queue operation is ok.
*/
static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb)
{
__skb_unlink(skb, &sk->sk_receive_queue);
if (
#ifdef CONFIG_RPS
!static_branch_unlikely(&rps_needed) &&
#endif
!sk->sk_rx_skb_cache) {
sk->sk_rx_skb_cache = skb;
skb_orphan(skb);
return;
}
__kfree_skb(skb);
}
static inline
struct net *sock_net(const struct sock *sk)
{
return read_pnet(&sk->sk_net);
}
static inline
void sock_net_set(struct sock *sk, struct net *net)
{
write_pnet(&sk->sk_net, net);
}
static inline struct sock *skb_steal_sock(struct sk_buff *skb)
{
if (skb->sk) {
struct sock *sk = skb->sk;
skb->destructor = NULL;
skb->sk = NULL;
return sk;
}
return NULL;
}
/* This helper checks if a socket is a full socket,
* ie _not_ a timewait or request socket.
*/
static inline bool sk_fullsock(const struct sock *sk)
{
return (1 << sk->sk_state) & ~(TCPF_TIME_WAIT | TCPF_NEW_SYN_RECV);
}
/* Checks if this SKB belongs to an HW offloaded socket
* and whether any SW fallbacks are required based on dev.
*/
static inline struct sk_buff *sk_validate_xmit_skb(struct sk_buff *skb,
struct net_device *dev)
{
#ifdef CONFIG_SOCK_VALIDATE_XMIT
struct sock *sk = skb->sk;
if (sk && sk_fullsock(sk) && sk->sk_validate_xmit_skb)
skb = sk->sk_validate_xmit_skb(sk, dev, skb);
#endif
return skb;
}
/* This helper checks if a socket is a LISTEN or NEW_SYN_RECV
* SYNACK messages can be attached to either ones (depending on SYNCOOKIE)
*/
static inline bool sk_listener(const struct sock *sk)
{
return (1 << sk->sk_state) & (TCPF_LISTEN | TCPF_NEW_SYN_RECV);
}
void sock_enable_timestamp(struct sock *sk, int flag);
int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len, int level,
int type);
bool sk_ns_capable(const struct sock *sk,
struct user_namespace *user_ns, int cap);
bool sk_capable(const struct sock *sk, int cap);
bool sk_net_capable(const struct sock *sk, int cap);
void sk_get_meminfo(const struct sock *sk, u32 *meminfo);
/* Take into consideration the size of the struct sk_buff overhead in the
* determination of these values, since that is non-constant across
* platforms. This makes socket queueing behavior and performance
* not depend upon such differences.
*/
#define _SK_MEM_PACKETS 256
#define _SK_MEM_OVERHEAD SKB_TRUESIZE(256)
#define SK_WMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
#define SK_RMEM_MAX (_SK_MEM_OVERHEAD * _SK_MEM_PACKETS)
extern __u32 sysctl_wmem_max;
extern __u32 sysctl_rmem_max;
extern int sysctl_tstamp_allow_data;
extern int sysctl_optmem_max;
extern __u32 sysctl_wmem_default;
extern __u32 sysctl_rmem_default;
static inline int sk_get_wmem0(const struct sock *sk, const struct proto *proto)
{
/* Does this proto have per netns sysctl_wmem ? */
if (proto->sysctl_wmem_offset)
return *(int *)((void *)sock_net(sk) + proto->sysctl_wmem_offset);
return *proto->sysctl_wmem;
}
static inline int sk_get_rmem0(const struct sock *sk, const struct proto *proto)
{
/* Does this proto have per netns sysctl_rmem ? */
if (proto->sysctl_rmem_offset)
return *(int *)((void *)sock_net(sk) + proto->sysctl_rmem_offset);
return *proto->sysctl_rmem;
}
/* Default TCP Small queue budget is ~1 ms of data (1sec >> 10)
* Some wifi drivers need to tweak it to get more chunks.
* They can use this helper from their ndo_start_xmit()
*/
static inline void sk_pacing_shift_update(struct sock *sk, int val)
{
if (!sk || !sk_fullsock(sk) || sk->sk_pacing_shift == val)
return;
sk->sk_pacing_shift = val;
}
/* if a socket is bound to a device, check that the given device
* index is either the same or that the socket is bound to an L3
* master device and the given device index is also enslaved to
* that L3 master
*/
static inline bool sk_dev_equal_l3scope(struct sock *sk, int dif)
{
int mdif;
if (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif)
return true;
mdif = l3mdev_master_ifindex_by_index(sock_net(sk), dif);
if (mdif && mdif == sk->sk_bound_dev_if)
return true;
return false;
}
#endif /* _SOCK_H */
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