/* * 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/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_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_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_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; struct proto *sk_prot_creator; rwlock_t sk_callback_lock; int sk_err, sk_err_soft; unsigned short sk_ack_backlog; unsigned short sk_max_ack_backlog; __u32 sk_priority; struct 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); struct request_sock_ops; /* 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 request_sock_ops *rsk_prot; 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 */