/* * 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/timer.h> #include <linux/cache.h> #include <linux/module.h> #include <linux/lockdep.h> #include <linux/netdevice.h> #include <linux/pcounter.h> #include <linux/skbuff.h> /* struct sk_buff */ #include <linux/mm.h> #include <linux/security.h> #include <linux/filter.h> #include <asm/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 #define SOCK_DEBUG(sk, msg...) do { } while (0) #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_family: network address family * @skc_state: Connection state * @skc_reuse: %SO_REUSEADDR setting * @skc_bound_dev_if: bound device index if != 0 * @skc_node: main hash linkage for various protocol lookup tables * @skc_bind_node: bind hash linkage for various protocol lookup tables * @skc_refcnt: reference count * @skc_hash: hash value used with various protocol lookup tables * @skc_prot: protocol handlers inside a network family * @skc_net: reference to the network namespace of this socket * * This is the minimal network layer representation of sockets, the header * for struct sock and struct inet_timewait_sock. */ struct sock_common { unsigned short skc_family; volatile unsigned char skc_state; unsigned char skc_reuse; int skc_bound_dev_if; struct hlist_node skc_node; struct hlist_node skc_bind_node; atomic_t skc_refcnt; unsigned int skc_hash; struct proto *skc_prot; struct net *skc_net; }; /** * 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_sleep: sock wait queue * @sk_dst_cache: destination cache * @sk_dst_lock: destination cache lock * @sk_policy: flow policy * @sk_rmem_alloc: receive queue bytes committed * @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 * @sk_no_check: %SO_NO_CHECK setting, wether or not checkup packets * @sk_route_caps: route capabilities (e.g. %NETIF_F_TSO) * @sk_gso_type: GSO type (e.g. %SKB_GSO_TCPV4) * @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 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_peercred: %SO_PEERCRED setting * @sk_rcvlowat: %SO_RCVLOWAT setting * @sk_rcvtimeo: %SO_RCVTIMEO setting * @sk_sndtimeo: %SO_SNDTIMEO setting * @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_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_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_node __sk_common.skc_node #define sk_bind_node __sk_common.skc_bind_node #define sk_refcnt __sk_common.skc_refcnt #define sk_hash __sk_common.skc_hash #define sk_prot __sk_common.skc_prot #define sk_net __sk_common.skc_net unsigned char sk_shutdown : 2, sk_no_check : 2, sk_userlocks : 4; unsigned char sk_protocol; unsigned short sk_type; int sk_rcvbuf; socket_lock_t sk_lock; /* * 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. */ struct { struct sk_buff *head; struct sk_buff *tail; } sk_backlog; wait_queue_head_t *sk_sleep; struct dst_entry *sk_dst_cache; struct xfrm_policy *sk_policy[2]; rwlock_t sk_dst_lock; atomic_t sk_rmem_alloc; atomic_t sk_wmem_alloc; atomic_t sk_omem_alloc; int sk_sndbuf; struct sk_buff_head sk_receive_queue; struct sk_buff_head sk_write_queue; struct sk_buff_head sk_async_wait_queue; int sk_wmem_queued; int sk_forward_alloc; gfp_t sk_allocation; int sk_route_caps; int sk_gso_type; int sk_rcvlowat; unsigned long sk_flags; 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; atomic_t sk_drops; unsigned short sk_ack_backlog; unsigned short sk_max_ack_backlog; __u32 sk_priority; struct ucred sk_peercred; long sk_rcvtimeo; long sk_sndtimeo; struct sk_filter *sk_filter; 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; void *sk_security; __u32 sk_mark; /* XXX 4 bytes hole on 64 bit */ 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_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_next(const struct sock *sk) { return sk->sk_node.next ? hlist_entry(sk->sk_node.next, struct sock, sk_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_del_node(struct sock *sk) { __hlist_del(&sk->sk_node); } 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; } 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_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_from(__sk, node) \ if (__sk && ({ node = &(__sk)->sk_node; 1; })) \ hlist_for_each_entry_from(__sk, node, sk_node) #define sk_for_each_continue(__sk, node) \ if (__sk && ({ node = &(__sk)->sk_node; 1; })) \ hlist_for_each_entry_continue(__sk, node, sk_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 */ }; 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; } /* The per-socket spinlock must be held here. */ static inline void sk_add_backlog(struct sock *sk, struct sk_buff *skb) { if (!sk->sk_backlog.tail) { sk->sk_backlog.head = sk->sk_backlog.tail = skb; } else { sk->sk_backlog.tail->next = skb; sk->sk_backlog.tail = skb; } skb->next = NULL; } #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; /* 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); int (*destroy)(struct sock *sk); void (*shutdown)(struct sock *sk, int how); int (*setsockopt)(struct sock *sk, int level, int optname, char __user *optval, int optlen); int (*getsockopt)(struct sock *sk, int level, int optname, char __user *optval, int __user *option); int (*compat_setsockopt)(struct sock *sk, int level, int optname, char __user *optval, int optlen); int (*compat_getsockopt)(struct sock *sk, int level, int optname, char __user *optval, int __user *option); 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); int (*get_port)(struct sock *sk, unsigned short snum); /* Keeping track of sockets in use */ #ifdef CONFIG_PROC_FS struct pcounter inuse; #endif /* Memory pressure */ void (*enter_memory_pressure)(void); atomic_t *memory_allocated; /* Current allocated memory. */ atomic_t *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; int *sysctl_mem; int *sysctl_wmem; int *sysctl_rmem; int max_header; struct kmem_cache *slab; unsigned int obj_size; atomic_t *orphan_count; struct request_sock_ops *rsk_prot; struct timewait_sock_ops *twsk_prot; struct inet_hashinfo *hashinfo; 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 # define DEFINE_PROTO_INUSE(NAME) DEFINE_PCOUNTER(NAME) # define REF_PROTO_INUSE(NAME) PCOUNTER_MEMBER_INITIALIZER(NAME, .inuse) /* Called with local bh disabled */ static inline void sock_prot_inuse_add(struct proto *prot, int inc) { pcounter_add(&prot->inuse, inc); } static inline int sock_prot_inuse_init(struct proto *proto) { return pcounter_alloc(&proto->inuse); } static inline int sock_prot_inuse_get(struct proto *proto) { return pcounter_getval(&proto->inuse); } static inline void sock_prot_inuse_free(struct proto *proto) { pcounter_free(&proto->inuse); } #else # define DEFINE_PROTO_INUSE(NAME) # define REF_PROTO_INUSE(NAME) static void inline sock_prot_inuse_add(struct proto *prot, int inc) { } static int inline sock_prot_inuse_init(struct proto *proto) { return 0; } static void inline sock_prot_inuse_free(struct proto *proto) { } #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); } /* 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) { skb_truesize_check(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 struct sock *sk_alloc(struct net *net, int family, gfp_t priority, struct proto *prot); extern void sk_free(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, 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 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); /* * 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 *, 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, 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, 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); /** * sk_filter - run a packet through a socket filter * @sk: sock associated with &sk_buff * @skb: buffer to filter * @needlock: set to 1 if the sock is not locked by caller. * * Run the filter code and then cut skb->data to correct size returned by * sk_run_filter. If pkt_len is 0 we toss packet. If skb->len is smaller * than pkt_len we keep whole skb->data. This is the socket level * wrapper to sk_run_filter. It returns 0 if the packet should * be accepted or -EPERM if the packet should be tossed. * */ static inline int sk_filter(struct sock *sk, struct sk_buff *skb) { int err; struct sk_filter *filter; err = security_sock_rcv_skb(sk, skb); if (err) return err; rcu_read_lock_bh(); filter = rcu_dereference(sk->sk_filter); if (filter) { unsigned int pkt_len = sk_run_filter(skb, filter->insns, filter->len); err = pkt_len ? pskb_trim(skb, pkt_len) : -EPERM; } rcu_read_unlock_bh(); return err; } /** * sk_filter_release: Release a socket filter * @sk: socket * @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)) kfree(fp); } 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); /* 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->sk_socket = NULL; sk->sk_sleep = 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_sleep = &parent->wait; parent->sk = sk; sk->sk_socket = 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 sk->sk_dst_cache; } static inline struct dst_entry * sk_dst_get(struct sock *sk) { struct dst_entry *dst; read_lock(&sk->sk_dst_lock); dst = sk->sk_dst_cache; if (dst) dst_hold(dst); read_unlock(&sk->sk_dst_lock); return dst; } static inline void __sk_dst_set(struct sock *sk, struct dst_entry *dst) { struct dst_entry *old_dst; old_dst = sk->sk_dst_cache; sk->sk_dst_cache = dst; dst_release(old_dst); } static inline void sk_dst_set(struct sock *sk, struct dst_entry *dst) { write_lock(&sk->sk_dst_lock); __sk_dst_set(sk, dst); write_unlock(&sk->sk_dst_lock); } static inline void __sk_dst_reset(struct sock *sk) { struct dst_entry *old_dst; old_dst = sk->sk_dst_cache; sk->sk_dst_cache = NULL; dst_release(old_dst); } static inline void sk_dst_reset(struct sock *sk) { write_lock(&sk->sk_dst_lock); __sk_dst_reset(sk); write_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 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; } /* * 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) { sock_hold(sk); skb->sk = sk; skb->destructor = sock_wfree; atomic_add(skb->truesize, &sk->sk_wmem_alloc); } static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk) { 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); static inline int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb) { /* Cast skb->rcvbuf to unsigned... It's pointless, but reduces number of warnings when compiling with -W --ANK */ if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >= (unsigned)sk->sk_rcvbuf) return -ENOMEM; skb_set_owner_r(skb, sk); skb_queue_tail(&sk->sk_error_queue, skb); if (!sock_flag(sk, SOCK_DEAD)) sk->sk_data_ready(sk, skb->len); return 0; } /* * 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 (sk->sk_socket && sk->sk_socket->fasync_list) sock_wake_async(sk->sk_socket, how, band); } #define SOCK_MIN_SNDBUF 2048 #define SOCK_MIN_RCVBUF 256 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_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_atomic() ? 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; if (sock_flag(sk, SOCK_RCVTSTAMP)) __sock_recv_timestamp(msg, sk, skb); else sk->sk_stamp = kt; } /** * 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 extern void sock_enable_timestamp(struct sock *sk); 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) /* * Macros for sleeping on a socket. Use them like this: * * SOCK_SLEEP_PRE(sk) * if (condition) * schedule(); * SOCK_SLEEP_POST(sk) * * N.B. These are now obsolete and were, afaik, only ever used in DECnet * and when the last use of them in DECnet has gone, I'm intending to * remove them. */ #define SOCK_SLEEP_PRE(sk) { struct task_struct *tsk = current; \ DECLARE_WAITQUEUE(wait, tsk); \ tsk->state = TASK_INTERRUPTIBLE; \ add_wait_queue((sk)->sk_sleep, &wait); \ release_sock(sk); #define SOCK_SLEEP_POST(sk) tsk->state = TASK_RUNNING; \ remove_wait_queue((sk)->sk_sleep, &wait); \ lock_sock(sk); \ } 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 */