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Diffstat (limited to 'include/net/sock.h')
| -rw-r--r-- | include/net/sock.h | 1297 |
1 files changed, 1297 insertions, 0 deletions
diff --git a/include/net/sock.h b/include/net/sock.h new file mode 100644 index 0000000..be81cab --- /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 */ |
