diff options
Diffstat (limited to 'include/net/sock.h')
| -rw-r--r-- | include/net/sock.h | 1851 |
1 files changed, 1851 insertions, 0 deletions
diff --git a/include/net/sock.h b/include/net/sock.h new file mode 100644 index 00000000..c0b938cb --- /dev/null +++ b/include/net/sock.h @@ -0,0 +1,1851 @@ +/* + * 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/kernel.h> +#include <linux/list.h> +#include <linux/list_nulls.h> +#include <linux/timer.h> +#include <linux/cache.h> +#include <linux/module.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/filter.h> +#include <linux/rculist_nulls.h> +#include <linux/poll.h> + +#include <linux/atomic.h> +#include <net/dst.h> +#include <net/checksum.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 void __attribute__ ((format (printf, 2, 3))) +SOCK_DEBUG(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; + +/** + * 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_family: network address family + * @skc_state: Connection state + * @skc_reuse: %SO_REUSEADDR 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_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 : + * cf INET_MATCH() and INET_TW_MATCH() + */ + __be32 skc_daddr; + __be32 skc_rcv_saddr; + + union { + unsigned int skc_hash; + __u16 skc_u16hashes[2]; + }; + unsigned short skc_family; + volatile unsigned char skc_state; + unsigned char skc_reuse; + int skc_bound_dev_if; + union { + struct hlist_node skc_bind_node; + struct hlist_nulls_node skc_portaddr_node; + }; + struct proto *skc_prot; +#ifdef CONFIG_NET_NS + struct net *skc_net; +#endif + /* + * 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; + }; + int skc_tx_queue_mapping; + atomic_t skc_refcnt; + /* private: */ + int skc_dontcopy_end[0]; + /* public: */ +}; + +/** + * 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_rcvbuf: size of receive buffer in bytes + * @sk_wq: sock wait queue and async head + * @sk_dst_cache: destination cache + * @sk_dst_lock: destination cache lock + * @sk_policy: flow policy + * @sk_receive_queue: incoming packets + * @sk_wmem_alloc: transmit queue bytes committed + * @sk_write_queue: Packet sending queue + * @sk_async_wait_queue: DMA copied packets + * @sk_omem_alloc: "o" is "option" or "other" + * @sk_wmem_queued: persistent queue size + * @sk_forward_alloc: space allocated forward + * @sk_allocation: allocation mode + * @sk_sndbuf: size of send buffer in bytes + * @sk_flags: %SO_LINGER (l_onoff), %SO_BROADCAST, %SO_KEEPALIVE, + * %SO_OOBINLINE settings, %SO_TIMESTAMPING settings + * @sk_no_check: %SO_NO_CHECK setting, wether or not checkup 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_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_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_rxhash: flow hash received from netif layer + * @sk_filter: socket filtering instructions + * @sk_protinfo: private area, net family specific, when not using slab + * @sk_timer: sock cleanup timer + * @sk_stamp: time stamp of last packet received + * @sk_socket: Identd and reporting IO signals + * @sk_user_data: RPC layer private data + * @sk_sndmsg_page: cached page for sendmsg + * @sk_sndmsg_off: cached offset for sendmsg + * @sk_send_head: front of stuff to transmit + * @sk_security: used by security modules + * @sk_mark: generic packet mark + * @sk_classid: this socket's cgroup classid + * @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 + */ +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 + +#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_family __sk_common.skc_family +#define sk_state __sk_common.skc_state +#define sk_reuse __sk_common.skc_reuse +#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 + socket_lock_t sk_lock; + 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_RPS + __u32 sk_rxhash; +#endif + atomic_t sk_drops; + int sk_rcvbuf; + + struct sk_filter __rcu *sk_filter; + struct socket_wq __rcu *sk_wq; + +#ifdef CONFIG_NET_DMA + struct sk_buff_head sk_async_wait_queue; +#endif + +#ifdef CONFIG_XFRM + struct xfrm_policy *sk_policy[2]; +#endif + unsigned long sk_flags; + struct dst_entry *sk_dst_cache; + spinlock_t sk_dst_lock; + atomic_t sk_wmem_alloc; + atomic_t sk_omem_alloc; + int sk_sndbuf; + struct sk_buff_head sk_write_queue; + kmemcheck_bitfield_begin(flags); + unsigned int sk_shutdown : 2, + sk_no_check : 2, + sk_userlocks : 4, + sk_protocol : 8, + sk_type : 16; + kmemcheck_bitfield_end(flags); + int sk_wmem_queued; + gfp_t sk_allocation; + int sk_route_caps; + int sk_route_nocaps; + int sk_gso_type; + unsigned int sk_gso_max_size; + int sk_rcvlowat; + unsigned long sk_lingertime; + struct sk_buff_head sk_error_queue; + struct proto *sk_prot_creator; + rwlock_t sk_callback_lock; + int sk_err, + sk_err_soft; + unsigned short sk_ack_backlog; + unsigned short sk_max_ack_backlog; + __u32 sk_priority; + struct pid *sk_peer_pid; + const struct cred *sk_peer_cred; + long sk_rcvtimeo; + long sk_sndtimeo; + void *sk_protinfo; + struct timer_list sk_timer; + ktime_t sk_stamp; + struct socket *sk_socket; + void *sk_user_data; + struct page *sk_sndmsg_page; + struct sk_buff *sk_send_head; + __u32 sk_sndmsg_off; + int sk_write_pending; +#ifdef CONFIG_SECURITY + void *sk_security; +#endif + __u32 sk_mark; + u32 sk_classid; + void (*sk_state_change)(struct sock *sk); + void (*sk_data_ready)(struct sock *sk, int bytes); + 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); + void (*sk_destruct)(struct sock *sk); +}; + +/* + * 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 sk->sk_node.next ? + hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL; +} + +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 int sk_unhashed(const struct sock *sk) +{ + return hlist_unhashed(&sk->sk_node); +} + +static inline int 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__ int __sk_del_node_init(struct sock *sk) +{ + if (sk_hashed(sk)) { + __sk_del_node(sk); + sk_node_init(&sk->sk_node); + return 1; + } + return 0; +} + +/* 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 inline void sock_hold(struct sock *sk) +{ + atomic_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 inline void __sock_put(struct sock *sk) +{ + atomic_dec(&sk->sk_refcnt); +} + +static __inline__ int sk_del_node_init(struct sock *sk) +{ + int rc = __sk_del_node_init(sk); + + if (rc) { + /* paranoid for a while -acme */ + WARN_ON(atomic_read(&sk->sk_refcnt) == 1); + __sock_put(sk); + } + return rc; +} +#define sk_del_node_init_rcu(sk) sk_del_node_init(sk) + +static __inline__ int __sk_nulls_del_node_init_rcu(struct sock *sk) +{ + if (sk_hashed(sk)) { + hlist_nulls_del_init_rcu(&sk->sk_nulls_node); + return 1; + } + return 0; +} + +static __inline__ int sk_nulls_del_node_init_rcu(struct sock *sk) +{ + int rc = __sk_nulls_del_node_init_rcu(sk); + + if (rc) { + /* paranoid for a while -acme */ + WARN_ON(atomic_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); + hlist_add_head_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, node, list) \ + hlist_for_each_entry(__sk, node, list, sk_node) +#define sk_for_each_rcu(__sk, node, list) \ + hlist_for_each_entry_rcu(__sk, node, 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, node) \ + if (__sk && ({ node = &(__sk)->sk_node; 1; })) \ + hlist_for_each_entry_from(__sk, node, 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, node, tmp, list) \ + hlist_for_each_entry_safe(__sk, node, tmp, list, sk_node) +#define sk_for_each_bound(__sk, node, list) \ + hlist_for_each_entry(__sk, node, list, sk_bind_node) + +/* 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_TIMESTAMPING_TX_HARDWARE, /* %SOF_TIMESTAMPING_TX_HARDWARE */ + SOCK_TIMESTAMPING_TX_SOFTWARE, /* %SOF_TIMESTAMPING_TX_SOFTWARE */ + SOCK_TIMESTAMPING_RX_HARDWARE, /* %SOF_TIMESTAMPING_RX_HARDWARE */ + SOCK_TIMESTAMPING_RX_SOFTWARE, /* %SOF_TIMESTAMPING_RX_SOFTWARE */ + SOCK_TIMESTAMPING_SOFTWARE, /* %SOF_TIMESTAMPING_SOFTWARE */ + SOCK_TIMESTAMPING_RAW_HARDWARE, /* %SOF_TIMESTAMPING_RAW_HARDWARE */ + SOCK_TIMESTAMPING_SYS_HARDWARE, /* %SOF_TIMESTAMPING_SYS_HARDWARE */ + SOCK_FASYNC, /* fasync() active */ + SOCK_RXQ_OVFL, +}; + +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 int sock_flag(struct sock *sk, enum sock_flags flag) +{ + return test_bit(flag, &sk->sk_flags); +} + +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 int sk_acceptq_is_full(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(struct sock *sk) +{ + return sk->sk_wmem_queued >> 1; +} + +static inline int sk_stream_wspace(struct sock *sk) +{ + return sk->sk_sndbuf - sk->sk_wmem_queued; +} + +extern void sk_stream_write_space(struct sock *sk); + +static inline int sk_stream_memory_free(struct sock *sk) +{ + return sk->sk_wmem_queued < sk->sk_sndbuf; +} + +/* 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 + */ +static inline bool sk_rcvqueues_full(const struct sock *sk, const struct sk_buff *skb) +{ + unsigned int qsize = sk->sk_backlog.len + atomic_read(&sk->sk_rmem_alloc); + + return qsize + skb->truesize > sk->sk_rcvbuf; +} + +/* The per-socket spinlock must be held here. */ +static inline __must_check int sk_add_backlog(struct sock *sk, struct sk_buff *skb) +{ + if (sk_rcvqueues_full(sk, skb)) + return -ENOBUFS; + + __sk_add_backlog(sk, skb); + sk->sk_backlog.len += skb->truesize; + return 0; +} + +static inline int sk_backlog_rcv(struct sock *sk, struct sk_buff *skb) +{ + return sk->sk_backlog_rcv(sk, skb); +} + +static inline void sock_rps_record_flow(const struct sock *sk) +{ +#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, sk->sk_rxhash); + rcu_read_unlock(); +#endif +} + +static inline void sock_rps_reset_flow(const struct sock *sk) +{ +#ifdef CONFIG_RPS + struct rps_sock_flow_table *sock_flow_table; + + rcu_read_lock(); + sock_flow_table = rcu_dereference(rps_sock_flow_table); + rps_reset_sock_flow(sock_flow_table, sk->sk_rxhash); + rcu_read_unlock(); +#endif +} + +static inline void sock_rps_save_rxhash(struct sock *sk, u32 rxhash) +{ +#ifdef CONFIG_RPS + if (unlikely(sk->sk_rxhash != rxhash)) { + sock_rps_reset_flow(sk); + sk->sk_rxhash = rxhash; + } +#endif +} + +#define sk_wait_event(__sk, __timeo, __condition) \ + ({ int __rc; \ + release_sock(__sk); \ + __rc = __condition; \ + if (!__rc) { \ + *(__timeo) = schedule_timeout(*(__timeo)); \ + } \ + lock_sock(__sk); \ + __rc = __condition; \ + __rc; \ + }) + +extern int sk_stream_wait_connect(struct sock *sk, long *timeo_p); +extern int sk_stream_wait_memory(struct sock *sk, long *timeo_p); +extern void sk_stream_wait_close(struct sock *sk, long timeo_p); +extern int sk_stream_error(struct sock *sk, int flags, int err); +extern void sk_stream_kill_queues(struct sock *sk); + +extern int sk_wait_data(struct sock *sk, long *timeo); + +struct request_sock_ops; +struct timewait_sock_ops; +struct inet_hashinfo; +struct raw_hashinfo; + +/* Networking protocol blocks we attach to sockets. + * socket layer -> transport layer interface + * transport -> network interface is defined by struct inet_proto + */ +struct proto { + void (*close)(struct sock *sk, + long timeout); + 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); + + 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); +#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 kiocb *iocb, struct sock *sk, + struct msghdr *msg, size_t len); + int (*recvmsg)(struct kiocb *iocb, 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); + + /* Keeping track of sk's, looking them up, and port selection methods. */ + void (*hash)(struct sock *sk); + void (*unhash)(struct sock *sk); + void (*rehash)(struct sock *sk); + int (*get_port)(struct sock *sk, unsigned short snum); + void (*clear_sk)(struct sock *sk, int size); + + /* Keeping track of sockets in use */ +#ifdef CONFIG_PROC_FS + unsigned int inuse_idx; +#endif + + /* Memory pressure */ + void (*enter_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. + */ + int *memory_pressure; + long *sysctl_mem; + int *sysctl_wmem; + int *sysctl_rmem; + int max_header; + bool no_autobind; + + struct kmem_cache *slab; + unsigned int obj_size; + int slab_flags; + + 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; + } h; + + struct module *owner; + + char name[32]; + + struct list_head node; +#ifdef SOCK_REFCNT_DEBUG + atomic_t socks; +#endif +}; + +extern int proto_register(struct proto *prot, int alloc_slab); +extern void proto_unregister(struct proto *prot); + +#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 (atomic_read(&sk->sk_refcnt) != 1) + printk(KERN_DEBUG "Destruction of the %s socket %p delayed, refcnt=%d\n", + sk->sk_prot->name, sk, atomic_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 */ + + +#ifdef CONFIG_PROC_FS +/* Called with local bh disabled */ +extern void sock_prot_inuse_add(struct net *net, struct proto *prot, int inc); +extern int sock_prot_inuse_get(struct net *net, struct proto *proto); +#else +static void inline 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 void __sk_prot_rehash(struct sock *sk) +{ + sk->sk_prot->unhash(sk); + sk->sk_prot->hash(sk); +} + +void sk_prot_clear_portaddr_nulls(struct sock *sk, int size); + +/* 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 + +/* sock_iocb: used to kick off async processing of socket ios */ +struct sock_iocb { + struct list_head list; + + int flags; + int size; + struct socket *sock; + struct sock *sk; + struct scm_cookie *scm; + struct msghdr *msg, async_msg; + struct kiocb *kiocb; +}; + +static inline struct sock_iocb *kiocb_to_siocb(struct kiocb *iocb) +{ + return (struct sock_iocb *)iocb->private; +} + +static inline struct kiocb *siocb_to_kiocb(struct sock_iocb *si) +{ + return si->kiocb; +} + +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 + */ +extern int __sk_mem_schedule(struct sock *sk, int size, int kind); +extern void __sk_mem_reclaim(struct sock *sk); + +#define SK_MEM_QUANTUM ((int)PAGE_SIZE) +#define SK_MEM_QUANTUM_SHIFT ilog2(SK_MEM_QUANTUM) +#define SK_MEM_SEND 0 +#define SK_MEM_RECV 1 + +static inline int sk_mem_pages(int amt) +{ + return (amt + SK_MEM_QUANTUM - 1) >> SK_MEM_QUANTUM_SHIFT; +} + +static inline int sk_has_account(struct sock *sk) +{ + /* return true if protocol supports memory accounting */ + return !!sk->sk_prot->memory_allocated; +} + +static inline int sk_wmem_schedule(struct sock *sk, int size) +{ + if (!sk_has_account(sk)) + return 1; + return size <= sk->sk_forward_alloc || + __sk_mem_schedule(sk, size, SK_MEM_SEND); +} + +static inline int sk_rmem_schedule(struct sock *sk, int size) +{ + if (!sk_has_account(sk)) + return 1; + return size <= sk->sk_forward_alloc || + __sk_mem_schedule(sk, size, SK_MEM_RECV); +} + +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); +} + +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); +} + +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; +} + +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); + __kfree_skb(skb); +} + +/* 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. + */ +#define sock_owned_by_user(sk) ((sk)->sk_lock.owned) + +/* + * 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) + +extern void lock_sock_nested(struct sock *sk, int subclass); + +static inline void lock_sock(struct sock *sk) +{ + lock_sock_nested(sk, 0); +} + +extern 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)) + +extern 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); +} + + +extern struct sock *sk_alloc(struct net *net, int family, + gfp_t priority, + struct proto *prot); +extern void sk_free(struct sock *sk); +extern void sk_release_kernel(struct sock *sk); +extern struct sock *sk_clone(const struct sock *sk, + const gfp_t priority); + +extern struct sk_buff *sock_wmalloc(struct sock *sk, + unsigned long size, int force, + gfp_t priority); +extern struct sk_buff *sock_rmalloc(struct sock *sk, + unsigned long size, int force, + gfp_t priority); +extern void sock_wfree(struct sk_buff *skb); +extern void sock_rfree(struct sk_buff *skb); + +extern int sock_setsockopt(struct socket *sock, int level, + int op, char __user *optval, + unsigned int optlen); + +extern int sock_getsockopt(struct socket *sock, int level, + int op, char __user *optval, + int __user *optlen); +extern struct sk_buff *sock_alloc_send_skb(struct sock *sk, + unsigned long size, + int noblock, + int *errcode); +extern struct sk_buff *sock_alloc_send_pskb(struct sock *sk, + unsigned long header_len, + unsigned long data_len, + int noblock, + int *errcode); +extern void *sock_kmalloc(struct sock *sk, int size, + gfp_t priority); +extern void sock_kfree_s(struct sock *sk, void *mem, int size); +extern void sk_send_sigurg(struct sock *sk); + +#ifdef CONFIG_CGROUPS +extern void sock_update_classid(struct sock *sk); +#else +static inline void sock_update_classid(struct sock *sk) +{ +} +#endif + +/* + * Functions to fill in entries in struct proto_ops when a protocol + * does not implement a particular function. + */ +extern int sock_no_bind(struct socket *, + struct sockaddr *, int); +extern int sock_no_connect(struct socket *, + struct sockaddr *, int, int); +extern int sock_no_socketpair(struct socket *, + struct socket *); +extern int sock_no_accept(struct socket *, + struct socket *, int); +extern int sock_no_getname(struct socket *, + struct sockaddr *, int *, int); +extern unsigned int sock_no_poll(struct file *, struct socket *, + struct poll_table_struct *); +extern int sock_no_ioctl(struct socket *, unsigned int, + unsigned long); +extern int sock_no_listen(struct socket *, int); +extern int sock_no_shutdown(struct socket *, int); +extern int sock_no_getsockopt(struct socket *, int , int, + char __user *, int __user *); +extern int sock_no_setsockopt(struct socket *, int, int, + char __user *, unsigned int); +extern int sock_no_sendmsg(struct kiocb *, struct socket *, + struct msghdr *, size_t); +extern int sock_no_recvmsg(struct kiocb *, struct socket *, + struct msghdr *, size_t, int); +extern int sock_no_mmap(struct file *file, + struct socket *sock, + struct vm_area_struct *vma); +extern ssize_t sock_no_sendpage(struct socket *sock, + 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. + */ +extern int sock_common_getsockopt(struct socket *sock, int level, int optname, + char __user *optval, int __user *optlen); +extern int sock_common_recvmsg(struct kiocb *iocb, struct socket *sock, + struct msghdr *msg, size_t size, int flags); +extern int sock_common_setsockopt(struct socket *sock, int level, int optname, + char __user *optval, unsigned int optlen); +extern int compat_sock_common_getsockopt(struct socket *sock, int level, + int optname, char __user *optval, int __user *optlen); +extern int compat_sock_common_setsockopt(struct socket *sock, int level, + int optname, char __user *optval, unsigned int optlen); + +extern void sk_common_release(struct sock *sk); + +/* + * Default socket callbacks and setup code + */ + +/* Initialise core socket variables */ +extern void sock_init_data(struct socket *sock, struct sock *sk); + +extern void sk_filter_release_rcu(struct rcu_head *rcu); + +/** + * sk_filter_release - release a socket filter + * @fp: filter to remove + * + * Remove a filter from a socket and release its resources. + */ + +static inline void sk_filter_release(struct sk_filter *fp) +{ + if (atomic_dec_and_test(&fp->refcnt)) + call_rcu(&fp->rcu, sk_filter_release_rcu); +} + +static inline void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp) +{ + unsigned int size = sk_filter_len(fp); + + atomic_sub(size, &sk->sk_omem_alloc); + sk_filter_release(fp); +} + +static inline void sk_filter_charge(struct sock *sk, struct sk_filter *fp) +{ + atomic_inc(&fp->refcnt); + atomic_add(sk_filter_len(fp), &sk->sk_omem_alloc); +} + +/* + * 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 (atomic_dec_and_test(&sk->sk_refcnt)) + sk_free(sk); +} + +extern int sk_receive_skb(struct sock *sk, struct sk_buff *skb, + const int nested); + +static inline void sk_tx_queue_set(struct sock *sk, int tx_queue) +{ + sk->sk_tx_queue_mapping = tx_queue; +} + +static inline void sk_tx_queue_clear(struct sock *sk) +{ + sk->sk_tx_queue_mapping = -1; +} + +static inline int sk_tx_queue_get(const struct sock *sk) +{ + return sk ? sk->sk_tx_queue_mapping : -1; +} + +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) +{ + write_lock_bh(&sk->sk_callback_lock); + sk->sk_wq = parent->wq; + parent->sk = sk; + sk_set_socket(sk, parent); + security_sock_graft(sk, parent); + write_unlock_bh(&sk->sk_callback_lock); +} + +extern int sock_i_uid(struct sock *sk); +extern unsigned long sock_i_ino(struct sock *sk); + +static inline struct dst_entry * +__sk_dst_get(struct sock *sk) +{ + return rcu_dereference_check(sk->sk_dst_cache, rcu_read_lock_held() || + sock_owned_by_user(sk) || + lockdep_is_held(&sk->sk_lock.slock)); +} + +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) + dst_hold(dst); + rcu_read_unlock(); + return dst; +} + +extern void sk_reset_txq(struct sock *sk); + +static inline void dst_negative_advice(struct sock *sk) +{ + struct dst_entry *ndst, *dst = __sk_dst_get(sk); + + if (dst && dst->ops->negative_advice) { + ndst = dst->ops->negative_advice(dst); + + if (ndst != dst) { + rcu_assign_pointer(sk->sk_dst_cache, ndst); + sk_reset_txq(sk); + } + } +} + +static inline void +__sk_dst_set(struct sock *sk, struct dst_entry *dst) +{ + struct dst_entry *old_dst; + + sk_tx_queue_clear(sk); + /* + * This can be called while sk is owned by the caller only, + * with no state that can be checked in a rcu_dereference_check() cond + */ + old_dst = rcu_dereference_raw(sk->sk_dst_cache); + 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) +{ + spin_lock(&sk->sk_dst_lock); + __sk_dst_set(sk, dst); + spin_unlock(&sk->sk_dst_lock); +} + +static inline void +__sk_dst_reset(struct sock *sk) +{ + __sk_dst_set(sk, NULL); +} + +static inline void +sk_dst_reset(struct sock *sk) +{ + spin_lock(&sk->sk_dst_lock); + __sk_dst_reset(sk); + spin_unlock(&sk->sk_dst_lock); +} + +extern struct dst_entry *__sk_dst_check(struct sock *sk, u32 cookie); + +extern struct dst_entry *sk_dst_check(struct sock *sk, u32 cookie); + +static inline int sk_can_gso(const struct sock *sk) +{ + return net_gso_ok(sk->sk_route_caps, sk->sk_gso_type); +} + +extern void sk_setup_caps(struct sock *sk, struct dst_entry *dst); + +static inline void sk_nocaps_add(struct sock *sk, int 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, + char __user *from, char *to, + int copy, int offset) +{ + if (skb->ip_summed == CHECKSUM_NONE) { + int err = 0; + __wsum csum = csum_and_copy_from_user(from, to, copy, 0, &err); + if (err) + return err; + skb->csum = csum_block_add(skb->csum, csum, offset); + } else if (sk->sk_route_caps & NETIF_F_NOCACHE_COPY) { + if (!access_ok(VERIFY_READ, from, copy) || + __copy_from_user_nocache(to, from, copy)) + return -EFAULT; + } else if (copy_from_user(to, from, copy)) + return -EFAULT; + + return 0; +} + +static inline int skb_add_data_nocache(struct sock *sk, struct sk_buff *skb, + char __user *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, char __user *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; +} + +static inline int skb_copy_to_page(struct sock *sk, char __user *from, + struct sk_buff *skb, struct page *page, + int off, int copy) +{ + if (skb->ip_summed == CHECKSUM_NONE) { + int err = 0; + __wsum csum = csum_and_copy_from_user(from, + page_address(page) + off, + copy, 0, &err); + if (err) + return err; + skb->csum = csum_block_add(skb->csum, csum, skb->len); + } else if (copy_from_user(page_address(page) + off, from, copy)) + return -EFAULT; + + 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 atomic_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 int sk_has_allocations(const struct sock *sk) +{ + return sk_wmem_alloc_get(sk) || sk_rmem_alloc_get(sk); +} + +/** + * wq_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 wq_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 wq_has_sleeper(struct socket_wq *wq) +{ + + /* + * We need to be sure we are in sync with the + * add_wait_queue modifications to the wait queue. + * + * This memory barrier is paired in the sock_poll_wait. + */ + smp_mb(); + return wq && waitqueue_active(&wq->wait); +} + +/** + * sock_poll_wait - place memory barrier behind the poll_wait call. + * @filp: file + * @wait_address: socket wait queue + * @p: poll_table + * + * See the comments in the wq_has_sleeper function. + */ +static inline void sock_poll_wait(struct file *filp, + wait_queue_head_t *wait_address, poll_table *p) +{ + if (p && wait_address) { + poll_wait(filp, wait_address, 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(); + } +} + +/* + * 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_w(struct sk_buff *skb, struct sock *sk) +{ + skb_orphan(skb); + skb->sk = sk; + skb->destructor = sock_wfree; + /* + * We used to take a refcount on sk, but following operation + * is enough to guarantee sk_free() wont free this sock until + * all in-flight packets are completed + */ + atomic_add(skb->truesize, &sk->sk_wmem_alloc); +} + +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); +} + +extern void sk_reset_timer(struct sock *sk, struct timer_list* timer, + unsigned long expires); + +extern void sk_stop_timer(struct sock *sk, struct timer_list* timer); + +extern int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); + +extern int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb); + +/* + * 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 - atomic_read(&sk->sk_wmem_alloc); + if (amt < 0) + amt = 0; + } + return amt; +} + +static inline void sk_wake_async(struct sock *sk, int how, int band) +{ + if (sock_flag(sk, SOCK_FASYNC)) + sock_wake_async(sk->sk_socket, how, band); +} + +#define SOCK_MIN_SNDBUF 2048 +/* + * Since sk_rmem_alloc sums skb->truesize, even a small frame might need + * sizeof(sk_buff) + MTU + padding, unless net driver perform copybreak + */ +#define SOCK_MIN_RCVBUF (2048 + sizeof(struct sk_buff)) + +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(sk->sk_sndbuf, SOCK_MIN_SNDBUF); + } +} + +struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp); + +static inline struct page *sk_stream_alloc_page(struct sock *sk) +{ + struct page *page = NULL; + + page = alloc_pages(sk->sk_allocation, 0); + if (!page) { + sk->sk_prot->enter_memory_pressure(sk); + sk_stream_moderate_sndbuf(sk); + } + return page; +} + +/* + * Default write policy as shown to user space via poll/select/SIGIO + */ +static inline int sock_writeable(const struct sock *sk) +{ + return atomic_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, int noblock) +{ + return noblock ? 0 : sk->sk_rcvtimeo; +} + +static inline long sock_sndtimeo(const struct sock *sk, int 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; +} + +extern void __sock_recv_timestamp(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 (SOCK_RCVTSTAMP + * or SOCK_TIMESTAMPING_RX_SOFTWARE) + * - software time stamp available and wanted + * (SOCK_TIMESTAMPING_SOFTWARE) + * - hardware time stamps available and wanted + * (SOCK_TIMESTAMPING_SYS_HARDWARE or + * SOCK_TIMESTAMPING_RAW_HARDWARE) + */ + if (sock_flag(sk, SOCK_RCVTSTAMP) || + sock_flag(sk, SOCK_TIMESTAMPING_RX_SOFTWARE) || + (kt.tv64 && sock_flag(sk, SOCK_TIMESTAMPING_SOFTWARE)) || + (hwtstamps->hwtstamp.tv64 && + sock_flag(sk, SOCK_TIMESTAMPING_RAW_HARDWARE)) || + (hwtstamps->syststamp.tv64 && + sock_flag(sk, SOCK_TIMESTAMPING_SYS_HARDWARE))) + __sock_recv_timestamp(msg, sk, skb); + else + sk->sk_stamp = kt; +} + +extern void __sock_recv_ts_and_drops(struct msghdr *msg, struct sock *sk, + struct sk_buff *skb); + +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) | \ + (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \ + (1UL << SOCK_TIMESTAMPING_SOFTWARE) | \ + (1UL << SOCK_TIMESTAMPING_RAW_HARDWARE) | \ + (1UL << SOCK_TIMESTAMPING_SYS_HARDWARE)) + + if (sk->sk_flags & FLAGS_TS_OR_DROPS) + __sock_recv_ts_and_drops(msg, sk, skb); + else + sk->sk_stamp = skb->tstamp; +} + +/** + * sock_tx_timestamp - checks whether the outgoing packet is to be time stamped + * @sk: socket sending this packet + * @tx_flags: filled with instructions for time stamping + * + * Currently only depends on SOCK_TIMESTAMPING* flags. Returns error code if + * parameters are invalid. + */ +extern int sock_tx_timestamp(struct sock *sk, __u8 *tx_flags); + +/** + * sk_eat_skb - Release a skb if it is no longer needed + * @sk: socket to eat this skb from + * @skb: socket buffer to eat + * @copied_early: flag indicating whether DMA operations copied this data early + * + * This routine must be called with interrupts disabled or with the socket + * locked so that the sk_buff queue operation is ok. +*/ +#ifdef CONFIG_NET_DMA +static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early) +{ + __skb_unlink(skb, &sk->sk_receive_queue); + if (!copied_early) + __kfree_skb(skb); + else + __skb_queue_tail(&sk->sk_async_wait_queue, skb); +} +#else +static inline void sk_eat_skb(struct sock *sk, struct sk_buff *skb, int copied_early) +{ + __skb_unlink(skb, &sk->sk_receive_queue); + __kfree_skb(skb); +} +#endif + +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); +} + +/* + * Kernel sockets, f.e. rtnl or icmp_socket, are a part of a namespace. + * They should not hold a reference to a namespace in order to allow + * to stop it. + * Sockets after sk_change_net should be released using sk_release_kernel + */ +static inline void sk_change_net(struct sock *sk, struct net *net) +{ + put_net(sock_net(sk)); + sock_net_set(sk, hold_net(net)); +} + +static inline struct sock *skb_steal_sock(struct sk_buff *skb) +{ + if (unlikely(skb->sk)) { + struct sock *sk = skb->sk; + + skb->destructor = NULL; + skb->sk = NULL; + return sk; + } + return NULL; +} + +extern void sock_enable_timestamp(struct sock *sk, int flag); +extern int sock_get_timestamp(struct sock *, struct timeval __user *); +extern int sock_get_timestampns(struct sock *, struct timespec __user *); + +/* + * Enable debug/info messages + */ +extern int net_msg_warn; +#define NETDEBUG(fmt, args...) \ + do { if (net_msg_warn) printk(fmt,##args); } while (0) + +#define LIMIT_NETDEBUG(fmt, args...) \ + do { if (net_msg_warn && net_ratelimit()) printk(fmt,##args); } while(0) + +extern __u32 sysctl_wmem_max; +extern __u32 sysctl_rmem_max; + +extern void sk_init(void); + +extern int sysctl_optmem_max; + +extern __u32 sysctl_wmem_default; +extern __u32 sysctl_rmem_default; + +#endif /* _SOCK_H */ |