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-rw-r--r--include/net/sock.h1297
1 files changed, 1297 insertions, 0 deletions
diff --git a/include/net/sock.h b/include/net/sock.h
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--- /dev/null
+++ b/include/net/sock.h
@@ -0,0 +1,1297 @@
+/*
+ * 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, <bir7@leland.Stanford.Edu>
+ * 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/config.h>
+#include <linux/list.h>
+#include <linux/timer.h>
+#include <linux/cache.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h> /* struct sk_buff */
+#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.
+ */
+struct sock_iocb;
+typedef struct {
+ spinlock_t slock;
+ struct sock_iocb *owner;
+ wait_queue_head_t wq;
+} socket_lock_t;
+
+#define sock_lock_init(__sk) \
+do { spin_lock_init(&((__sk)->sk_lock.slock)); \
+ (__sk)->sk_lock.owner = NULL; \
+ init_waitqueue_head(&((__sk)->sk_lock.wq)); \
+} while(0)
+
+struct sock;
+
+/**
+ * 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
+ *
+ * This is the minimal network layer representation of sockets, the header
+ * for struct sock and struct tcp_tw_bucket.
+ */
+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;
+};
+
+/**
+ * struct sock - network layer representation of sockets
+ * @__sk_common - shared layout with tcp_tw_bucket
+ * @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_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_lingertime - %SO_LINGER l_linger setting
+ * @sk_hashent - hash entry in several tables (e.g. tcp_ehash)
+ * @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 - protocol handlers inside a network family
+ * @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_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_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 tcp_tw_bucket 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
+ 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;
+ 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;
+ struct sk_buff_head sk_receive_queue;
+ struct sk_buff_head sk_write_queue;
+ int sk_wmem_queued;
+ int sk_forward_alloc;
+ unsigned int sk_allocation;
+ int sk_sndbuf;
+ int sk_route_caps;
+ int sk_hashent;
+ unsigned long sk_flags;
+ unsigned long sk_lingertime;
+ /*
+ * 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;
+ struct sk_buff_head sk_error_queue;
+ struct proto *sk_prot;
+ 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 ucred sk_peercred;
+ int sk_rcvlowat;
+ long sk_rcvtimeo;
+ long sk_sndtimeo;
+ struct sk_filter *sk_filter;
+ void *sk_protinfo;
+ struct timer_list sk_timer;
+ struct timeval 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;
+ 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(struct hlist_head *head)
+{
+ return hlist_entry(head->first, struct sock, sk_node);
+}
+
+static inline struct sock *sk_head(struct hlist_head *head)
+{
+ return hlist_empty(head) ? NULL : __sk_head(head);
+}
+
+static inline struct sock *sk_next(struct sock *sk)
+{
+ return sk->sk_node.next ?
+ hlist_entry(sk->sk_node.next, struct sock, sk_node) : NULL;
+}
+
+static inline int sk_unhashed(struct sock *sk)
+{
+ return hlist_unhashed(&sk->sk_node);
+}
+
+static inline int sk_hashed(struct sock *sk)
+{
+ return sk->sk_node.pprev != NULL;
+}
+
+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_NO_LARGESEND, /* whether to sent large segments or not */
+ SOCK_LOCALROUTE, /* route locally only, %SO_DONTROUTE setting */
+ SOCK_QUEUE_SHRUNK, /* write queue has been shrunk recently */
+};
+
+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 / 2;
+}
+
+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;
+}
+
+extern void sk_stream_rfree(struct sk_buff *skb);
+
+static inline void sk_stream_set_owner_r(struct sk_buff *skb, struct sock *sk)
+{
+ skb->sk = sk;
+ skb->destructor = sk_stream_rfree;
+ atomic_add(skb->truesize, &sk->sk_rmem_alloc);
+ sk->sk_forward_alloc -= skb->truesize;
+}
+
+static inline void sk_stream_free_skb(struct sock *sk, struct sk_buff *skb)
+{
+ sock_set_flag(sk, SOCK_QUEUE_SHRUNK);
+ sk->sk_wmem_queued -= skb->truesize;
+ sk->sk_forward_alloc += skb->truesize;
+ __kfree_skb(skb);
+}
+
+/* The per-socket spinlock must be held here. */
+#define sk_add_backlog(__sk, __skb) \
+do { 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; \
+} while(0)
+
+#define sk_wait_event(__sk, __timeo, __condition) \
+({ int rc; \
+ release_sock(__sk); \
+ rc = __condition; \
+ if (!rc) { \
+ *(__timeo) = schedule_timeout(*(__timeo)); \
+ rc = __condition; \
+ } \
+ lock_sock(__sk); \
+ 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);
+
+/* 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 (*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);
+
+ /* 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_stream_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;
+
+ kmem_cache_t *slab;
+ unsigned int obj_size;
+
+ struct module *owner;
+
+ char name[32];
+
+ struct list_head node;
+
+ struct {
+ int inuse;
+ u8 __pad[SMP_CACHE_BYTES - sizeof(int)];
+ } stats[NR_CPUS];
+};
+
+extern int proto_register(struct proto *prot, int alloc_slab);
+extern void proto_unregister(struct proto *prot);
+
+/* Called with local bh disabled */
+static __inline__ void sock_prot_inc_use(struct proto *prot)
+{
+ prot->stats[smp_processor_id()].inuse++;
+}
+
+static __inline__ void sock_prot_dec_use(struct proto *prot)
+{
+ prot->stats[smp_processor_id()].inuse--;
+}
+
+/* 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 iovec async_iov;
+ 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;
+}
+
+extern void __sk_stream_mem_reclaim(struct sock *sk);
+extern int sk_stream_mem_schedule(struct sock *sk, int size, int kind);
+
+#define SK_STREAM_MEM_QUANTUM ((int)PAGE_SIZE)
+
+static inline int sk_stream_pages(int amt)
+{
+ return (amt + SK_STREAM_MEM_QUANTUM - 1) / SK_STREAM_MEM_QUANTUM;
+}
+
+static inline void sk_stream_mem_reclaim(struct sock *sk)
+{
+ if (sk->sk_forward_alloc >= SK_STREAM_MEM_QUANTUM)
+ __sk_stream_mem_reclaim(sk);
+}
+
+static inline void sk_stream_writequeue_purge(struct sock *sk)
+{
+ struct sk_buff *skb;
+
+ while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL)
+ sk_stream_free_skb(sk, skb);
+ sk_stream_mem_reclaim(sk);
+}
+
+static inline int sk_stream_rmem_schedule(struct sock *sk, struct sk_buff *skb)
+{
+ return (int)skb->truesize <= sk->sk_forward_alloc ||
+ sk_stream_mem_schedule(sk, skb->truesize, 1);
+}
+
+/* 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.owner)
+
+extern void FASTCALL(lock_sock(struct sock *sk));
+extern void FASTCALL(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_unlock_sock(__sk) spin_unlock(&((__sk)->sk_lock.slock))
+
+extern struct sock *sk_alloc(int family, int priority,
+ struct proto *prot, int zero_it);
+extern void sk_free(struct sock *sk);
+
+extern struct sk_buff *sock_wmalloc(struct sock *sk,
+ unsigned long size, int force,
+ int priority);
+extern struct sk_buff *sock_rmalloc(struct sock *sk,
+ unsigned long size, int force,
+ int 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, int 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 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 needlock)
+{
+ int err;
+
+ err = security_sock_rcv_skb(sk, skb);
+ if (err)
+ return err;
+
+ if (sk->sk_filter) {
+ struct sk_filter *filter;
+
+ if (needlock)
+ bh_lock_sock(sk);
+
+ filter = sk->sk_filter;
+ if (filter) {
+ int pkt_len = sk_run_filter(skb, filter->insns,
+ filter->len);
+ if (!pkt_len)
+ err = -EPERM;
+ else
+ skb_trim(skb, pkt_len);
+ }
+
+ if (needlock)
+ bh_unlock_sock(sk);
+ }
+ 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 sock *sk, struct sk_filter *fp)
+{
+ unsigned int size = sk_filter_len(fp);
+
+ atomic_sub(size, &sk->sk_omem_alloc);
+
+ if (atomic_dec_and_test(&fp->refcnt))
+ kfree(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);
+}
+
+/* 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;
+ 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);
+}
+
+static inline struct dst_entry *
+__sk_dst_check(struct sock *sk, u32 cookie)
+{
+ struct dst_entry *dst = sk->sk_dst_cache;
+
+ if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
+ sk->sk_dst_cache = NULL;
+ dst_release(dst);
+ return NULL;
+ }
+
+ return dst;
+}
+
+static inline struct dst_entry *
+sk_dst_check(struct sock *sk, u32 cookie)
+{
+ struct dst_entry *dst = sk_dst_get(sk);
+
+ if (dst && dst->obsolete && dst->ops->check(dst, cookie) == NULL) {
+ sk_dst_reset(sk);
+ dst_release(dst);
+ return NULL;
+ }
+
+ return dst;
+}
+
+static inline void sk_charge_skb(struct sock *sk, struct sk_buff *skb)
+{
+ sk->sk_wmem_queued += skb->truesize;
+ sk->sk_forward_alloc -= skb->truesize;
+}
+
+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;
+ unsigned int 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->sk_forward_alloc -= 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);
+}
+
+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);
+
+static inline int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+ int err = 0;
+ int skb_len;
+
+ /* 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) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ /* It would be deadlock, if sock_queue_rcv_skb is used
+ with socket lock! We assume that users of this
+ function are lock free.
+ */
+ err = sk_filter(sk, skb, 1);
+ if (err)
+ goto out;
+
+ skb->dev = NULL;
+ skb_set_owner_r(skb, sk);
+
+ /* Cache the SKB length before we tack it onto the receive
+ * queue. Once it is added it no longer belongs to us and
+ * may be freed by other threads of control pulling packets
+ * from the queue.
+ */
+ skb_len = skb->len;
+
+ skb_queue_tail(&sk->sk_receive_queue, skb);
+
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk->sk_data_ready(sk, skb_len);
+out:
+ return err;
+}
+
+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 = 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 / 2);
+ sk->sk_sndbuf = max(sk->sk_sndbuf, SOCK_MIN_SNDBUF);
+ }
+}
+
+static inline struct sk_buff *sk_stream_alloc_pskb(struct sock *sk,
+ int size, int mem, int gfp)
+{
+ struct sk_buff *skb = alloc_skb(size + sk->sk_prot->max_header, gfp);
+
+ if (skb) {
+ skb->truesize += mem;
+ if (sk->sk_forward_alloc >= (int)skb->truesize ||
+ sk_stream_mem_schedule(sk, skb->truesize, 0)) {
+ skb_reserve(skb, sk->sk_prot->max_header);
+ return skb;
+ }
+ __kfree_skb(skb);
+ } else {
+ sk->sk_prot->enter_memory_pressure();
+ sk_stream_moderate_sndbuf(sk);
+ }
+ return NULL;
+}
+
+static inline struct sk_buff *sk_stream_alloc_skb(struct sock *sk,
+ int size, int gfp)
+{
+ return sk_stream_alloc_pskb(sk, size, 0, gfp);
+}
+
+static inline struct page *sk_stream_alloc_page(struct sock *sk)
+{
+ struct page *page = NULL;
+
+ if (sk->sk_forward_alloc >= (int)PAGE_SIZE ||
+ sk_stream_mem_schedule(sk, PAGE_SIZE, 0))
+ page = alloc_pages(sk->sk_allocation, 0);
+ else {
+ sk->sk_prot->enter_memory_pressure();
+ sk_stream_moderate_sndbuf(sk);
+ }
+ return page;
+}
+
+#define sk_stream_for_retrans_queue(skb, sk) \
+ for (skb = (sk)->sk_write_queue.next; \
+ (skb != (sk)->sk_send_head) && \
+ (skb != (struct sk_buff *)&(sk)->sk_write_queue); \
+ skb = skb->next)
+
+/*
+ * 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 / 2);
+}
+
+static inline int 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;
+}
+
+static __inline__ void
+sock_recv_timestamp(struct msghdr *msg, struct sock *sk, struct sk_buff *skb)
+{
+ struct timeval *stamp = &skb->stamp;
+ if (sock_flag(sk, SOCK_RCVTSTAMP)) {
+ /* Race occurred between timestamp enabling and packet
+ receiving. Fill in the current time for now. */
+ if (stamp->tv_sec == 0)
+ do_gettimeofday(stamp);
+ put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP, sizeof(struct timeval),
+ stamp);
+ } else
+ sk->sk_stamp = *stamp;
+}
+
+/**
+ * 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);
+ __kfree_skb(skb);
+}
+
+extern void sock_enable_timestamp(struct sock *sk);
+extern int sock_get_timestamp(struct sock *, struct timeval __user *);
+
+/*
+ * Enable debug/info messages
+ */
+
+#if 0
+#define NETDEBUG(x) do { } while (0)
+#define LIMIT_NETDEBUG(x) do {} while(0)
+#else
+#define NETDEBUG(x) do { x; } while (0)
+#define LIMIT_NETDEBUG(x) do { if (net_ratelimit()) { x; } } while(0)
+#endif
+
+/*
+ * 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); \
+ }
+
+static inline void sock_valbool_flag(struct sock *sk, int bit, int valbool)
+{
+ if (valbool)
+ sock_set_flag(sk, bit);
+ else
+ sock_reset_flag(sk, bit);
+}
+
+extern __u32 sysctl_wmem_max;
+extern __u32 sysctl_rmem_max;
+
+#ifdef CONFIG_NET
+int siocdevprivate_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg);
+#else
+static inline int siocdevprivate_ioctl(unsigned int fd, unsigned int cmd, unsigned long arg)
+{
+ return -ENODEV;
+}
+#endif
+
+#endif /* _SOCK_H */