| /* |
| * 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 TCP module. |
| * |
| * Version: @(#)tcp.h 1.0.5 05/23/93 |
| * |
| * Authors: Ross Biro |
| * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
| * |
| * 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 _TCP_H |
| #define _TCP_H |
| |
| #define TCP_DEBUG 1 |
| #define FASTRETRANS_DEBUG 1 |
| |
| /* Cancel timers, when they are not required. */ |
| #undef TCP_CLEAR_TIMERS |
| |
| #include <linux/config.h> |
| #include <linux/list.h> |
| #include <linux/tcp.h> |
| #include <linux/slab.h> |
| #include <linux/cache.h> |
| #include <linux/percpu.h> |
| #include <net/checksum.h> |
| #include <net/request_sock.h> |
| #include <net/sock.h> |
| #include <net/snmp.h> |
| #include <net/ip.h> |
| #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) |
| #include <linux/ipv6.h> |
| #endif |
| #include <linux/seq_file.h> |
| |
| /* This is for all connections with a full identity, no wildcards. |
| * New scheme, half the table is for TIME_WAIT, the other half is |
| * for the rest. I'll experiment with dynamic table growth later. |
| */ |
| struct tcp_ehash_bucket { |
| rwlock_t lock; |
| struct hlist_head chain; |
| } __attribute__((__aligned__(8))); |
| |
| /* This is for listening sockets, thus all sockets which possess wildcards. */ |
| #define TCP_LHTABLE_SIZE 32 /* Yes, really, this is all you need. */ |
| |
| /* There are a few simple rules, which allow for local port reuse by |
| * an application. In essence: |
| * |
| * 1) Sockets bound to different interfaces may share a local port. |
| * Failing that, goto test 2. |
| * 2) If all sockets have sk->sk_reuse set, and none of them are in |
| * TCP_LISTEN state, the port may be shared. |
| * Failing that, goto test 3. |
| * 3) If all sockets are bound to a specific inet_sk(sk)->rcv_saddr local |
| * address, and none of them are the same, the port may be |
| * shared. |
| * Failing this, the port cannot be shared. |
| * |
| * The interesting point, is test #2. This is what an FTP server does |
| * all day. To optimize this case we use a specific flag bit defined |
| * below. As we add sockets to a bind bucket list, we perform a |
| * check of: (newsk->sk_reuse && (newsk->sk_state != TCP_LISTEN)) |
| * As long as all sockets added to a bind bucket pass this test, |
| * the flag bit will be set. |
| * The resulting situation is that tcp_v[46]_verify_bind() can just check |
| * for this flag bit, if it is set and the socket trying to bind has |
| * sk->sk_reuse set, we don't even have to walk the owners list at all, |
| * we return that it is ok to bind this socket to the requested local port. |
| * |
| * Sounds like a lot of work, but it is worth it. In a more naive |
| * implementation (ie. current FreeBSD etc.) the entire list of ports |
| * must be walked for each data port opened by an ftp server. Needless |
| * to say, this does not scale at all. With a couple thousand FTP |
| * users logged onto your box, isn't it nice to know that new data |
| * ports are created in O(1) time? I thought so. ;-) -DaveM |
| */ |
| struct tcp_bind_bucket { |
| unsigned short port; |
| signed short fastreuse; |
| struct hlist_node node; |
| struct hlist_head owners; |
| }; |
| |
| #define tb_for_each(tb, node, head) hlist_for_each_entry(tb, node, head, node) |
| |
| struct tcp_bind_hashbucket { |
| spinlock_t lock; |
| struct hlist_head chain; |
| }; |
| |
| static inline struct tcp_bind_bucket *__tb_head(struct tcp_bind_hashbucket *head) |
| { |
| return hlist_entry(head->chain.first, struct tcp_bind_bucket, node); |
| } |
| |
| static inline struct tcp_bind_bucket *tb_head(struct tcp_bind_hashbucket *head) |
| { |
| return hlist_empty(&head->chain) ? NULL : __tb_head(head); |
| } |
| |
| extern struct tcp_hashinfo { |
| /* This is for sockets with full identity only. Sockets here will |
| * always be without wildcards and will have the following invariant: |
| * |
| * TCP_ESTABLISHED <= sk->sk_state < TCP_CLOSE |
| * |
| * First half of the table is for sockets not in TIME_WAIT, second half |
| * is for TIME_WAIT sockets only. |
| */ |
| struct tcp_ehash_bucket *__tcp_ehash; |
| |
| /* Ok, let's try this, I give up, we do need a local binding |
| * TCP hash as well as the others for fast bind/connect. |
| */ |
| struct tcp_bind_hashbucket *__tcp_bhash; |
| |
| int __tcp_bhash_size; |
| int __tcp_ehash_size; |
| |
| /* All sockets in TCP_LISTEN state will be in here. This is the only |
| * table where wildcard'd TCP sockets can exist. Hash function here |
| * is just local port number. |
| */ |
| struct hlist_head __tcp_listening_hash[TCP_LHTABLE_SIZE]; |
| |
| /* All the above members are written once at bootup and |
| * never written again _or_ are predominantly read-access. |
| * |
| * Now align to a new cache line as all the following members |
| * are often dirty. |
| */ |
| rwlock_t __tcp_lhash_lock ____cacheline_aligned; |
| atomic_t __tcp_lhash_users; |
| wait_queue_head_t __tcp_lhash_wait; |
| spinlock_t __tcp_portalloc_lock; |
| } tcp_hashinfo; |
| |
| #define tcp_ehash (tcp_hashinfo.__tcp_ehash) |
| #define tcp_bhash (tcp_hashinfo.__tcp_bhash) |
| #define tcp_ehash_size (tcp_hashinfo.__tcp_ehash_size) |
| #define tcp_bhash_size (tcp_hashinfo.__tcp_bhash_size) |
| #define tcp_listening_hash (tcp_hashinfo.__tcp_listening_hash) |
| #define tcp_lhash_lock (tcp_hashinfo.__tcp_lhash_lock) |
| #define tcp_lhash_users (tcp_hashinfo.__tcp_lhash_users) |
| #define tcp_lhash_wait (tcp_hashinfo.__tcp_lhash_wait) |
| #define tcp_portalloc_lock (tcp_hashinfo.__tcp_portalloc_lock) |
| |
| extern kmem_cache_t *tcp_bucket_cachep; |
| extern struct tcp_bind_bucket *tcp_bucket_create(struct tcp_bind_hashbucket *head, |
| unsigned short snum); |
| extern void tcp_bucket_destroy(struct tcp_bind_bucket *tb); |
| extern void tcp_bucket_unlock(struct sock *sk); |
| extern int tcp_port_rover; |
| |
| /* These are AF independent. */ |
| static __inline__ int tcp_bhashfn(__u16 lport) |
| { |
| return (lport & (tcp_bhash_size - 1)); |
| } |
| |
| extern void tcp_bind_hash(struct sock *sk, struct tcp_bind_bucket *tb, |
| unsigned short snum); |
| |
| #if (BITS_PER_LONG == 64) |
| #define TCP_ADDRCMP_ALIGN_BYTES 8 |
| #else |
| #define TCP_ADDRCMP_ALIGN_BYTES 4 |
| #endif |
| |
| /* This is a TIME_WAIT bucket. It works around the memory consumption |
| * problems of sockets in such a state on heavily loaded servers, but |
| * without violating the protocol specification. |
| */ |
| struct tcp_tw_bucket { |
| /* |
| * Now struct sock also uses sock_common, so please just |
| * don't add nothing before this first member (__tw_common) --acme |
| */ |
| struct sock_common __tw_common; |
| #define tw_family __tw_common.skc_family |
| #define tw_state __tw_common.skc_state |
| #define tw_reuse __tw_common.skc_reuse |
| #define tw_bound_dev_if __tw_common.skc_bound_dev_if |
| #define tw_node __tw_common.skc_node |
| #define tw_bind_node __tw_common.skc_bind_node |
| #define tw_refcnt __tw_common.skc_refcnt |
| volatile unsigned char tw_substate; |
| unsigned char tw_rcv_wscale; |
| __u16 tw_sport; |
| /* Socket demultiplex comparisons on incoming packets. */ |
| /* these five are in inet_sock */ |
| __u32 tw_daddr |
| __attribute__((aligned(TCP_ADDRCMP_ALIGN_BYTES))); |
| __u32 tw_rcv_saddr; |
| __u16 tw_dport; |
| __u16 tw_num; |
| /* And these are ours. */ |
| int tw_hashent; |
| int tw_timeout; |
| __u32 tw_rcv_nxt; |
| __u32 tw_snd_nxt; |
| __u32 tw_rcv_wnd; |
| __u32 tw_ts_recent; |
| long tw_ts_recent_stamp; |
| unsigned long tw_ttd; |
| struct tcp_bind_bucket *tw_tb; |
| struct hlist_node tw_death_node; |
| #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) |
| struct in6_addr tw_v6_daddr; |
| struct in6_addr tw_v6_rcv_saddr; |
| int tw_v6_ipv6only; |
| #endif |
| }; |
| |
| static __inline__ void tw_add_node(struct tcp_tw_bucket *tw, |
| struct hlist_head *list) |
| { |
| hlist_add_head(&tw->tw_node, list); |
| } |
| |
| static __inline__ void tw_add_bind_node(struct tcp_tw_bucket *tw, |
| struct hlist_head *list) |
| { |
| hlist_add_head(&tw->tw_bind_node, list); |
| } |
| |
| static inline int tw_dead_hashed(struct tcp_tw_bucket *tw) |
| { |
| return tw->tw_death_node.pprev != NULL; |
| } |
| |
| static __inline__ void tw_dead_node_init(struct tcp_tw_bucket *tw) |
| { |
| tw->tw_death_node.pprev = NULL; |
| } |
| |
| static __inline__ void __tw_del_dead_node(struct tcp_tw_bucket *tw) |
| { |
| __hlist_del(&tw->tw_death_node); |
| tw_dead_node_init(tw); |
| } |
| |
| static __inline__ int tw_del_dead_node(struct tcp_tw_bucket *tw) |
| { |
| if (tw_dead_hashed(tw)) { |
| __tw_del_dead_node(tw); |
| return 1; |
| } |
| return 0; |
| } |
| |
| #define tw_for_each(tw, node, head) \ |
| hlist_for_each_entry(tw, node, head, tw_node) |
| |
| #define tw_for_each_inmate(tw, node, jail) \ |
| hlist_for_each_entry(tw, node, jail, tw_death_node) |
| |
| #define tw_for_each_inmate_safe(tw, node, safe, jail) \ |
| hlist_for_each_entry_safe(tw, node, safe, jail, tw_death_node) |
| |
| #define tcptw_sk(__sk) ((struct tcp_tw_bucket *)(__sk)) |
| |
| static inline u32 tcp_v4_rcv_saddr(const struct sock *sk) |
| { |
| return likely(sk->sk_state != TCP_TIME_WAIT) ? |
| inet_sk(sk)->rcv_saddr : tcptw_sk(sk)->tw_rcv_saddr; |
| } |
| |
| #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) |
| static inline struct in6_addr *__tcp_v6_rcv_saddr(const struct sock *sk) |
| { |
| return likely(sk->sk_state != TCP_TIME_WAIT) ? |
| &inet6_sk(sk)->rcv_saddr : &tcptw_sk(sk)->tw_v6_rcv_saddr; |
| } |
| |
| static inline struct in6_addr *tcp_v6_rcv_saddr(const struct sock *sk) |
| { |
| return sk->sk_family == AF_INET6 ? __tcp_v6_rcv_saddr(sk) : NULL; |
| } |
| |
| #define tcptw_sk_ipv6only(__sk) (tcptw_sk(__sk)->tw_v6_ipv6only) |
| |
| static inline int tcp_v6_ipv6only(const struct sock *sk) |
| { |
| return likely(sk->sk_state != TCP_TIME_WAIT) ? |
| ipv6_only_sock(sk) : tcptw_sk_ipv6only(sk); |
| } |
| #else |
| # define __tcp_v6_rcv_saddr(__sk) NULL |
| # define tcp_v6_rcv_saddr(__sk) NULL |
| # define tcptw_sk_ipv6only(__sk) 0 |
| # define tcp_v6_ipv6only(__sk) 0 |
| #endif |
| |
| extern kmem_cache_t *tcp_timewait_cachep; |
| |
| static inline void tcp_tw_put(struct tcp_tw_bucket *tw) |
| { |
| if (atomic_dec_and_test(&tw->tw_refcnt)) { |
| #ifdef INET_REFCNT_DEBUG |
| printk(KERN_DEBUG "tw_bucket %p released\n", tw); |
| #endif |
| kmem_cache_free(tcp_timewait_cachep, tw); |
| } |
| } |
| |
| extern atomic_t tcp_orphan_count; |
| extern int tcp_tw_count; |
| extern void tcp_time_wait(struct sock *sk, int state, int timeo); |
| extern void tcp_tw_deschedule(struct tcp_tw_bucket *tw); |
| |
| |
| /* Socket demux engine toys. */ |
| #ifdef __BIG_ENDIAN |
| #define TCP_COMBINED_PORTS(__sport, __dport) \ |
| (((__u32)(__sport)<<16) | (__u32)(__dport)) |
| #else /* __LITTLE_ENDIAN */ |
| #define TCP_COMBINED_PORTS(__sport, __dport) \ |
| (((__u32)(__dport)<<16) | (__u32)(__sport)) |
| #endif |
| |
| #if (BITS_PER_LONG == 64) |
| #ifdef __BIG_ENDIAN |
| #define TCP_V4_ADDR_COOKIE(__name, __saddr, __daddr) \ |
| __u64 __name = (((__u64)(__saddr))<<32)|((__u64)(__daddr)); |
| #else /* __LITTLE_ENDIAN */ |
| #define TCP_V4_ADDR_COOKIE(__name, __saddr, __daddr) \ |
| __u64 __name = (((__u64)(__daddr))<<32)|((__u64)(__saddr)); |
| #endif /* __BIG_ENDIAN */ |
| #define TCP_IPV4_MATCH(__sk, __cookie, __saddr, __daddr, __ports, __dif)\ |
| (((*((__u64 *)&(inet_sk(__sk)->daddr)))== (__cookie)) && \ |
| ((*((__u32 *)&(inet_sk(__sk)->dport)))== (__ports)) && \ |
| (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif)))) |
| #define TCP_IPV4_TW_MATCH(__sk, __cookie, __saddr, __daddr, __ports, __dif)\ |
| (((*((__u64 *)&(tcptw_sk(__sk)->tw_daddr))) == (__cookie)) && \ |
| ((*((__u32 *)&(tcptw_sk(__sk)->tw_dport))) == (__ports)) && \ |
| (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif)))) |
| #else /* 32-bit arch */ |
| #define TCP_V4_ADDR_COOKIE(__name, __saddr, __daddr) |
| #define TCP_IPV4_MATCH(__sk, __cookie, __saddr, __daddr, __ports, __dif)\ |
| ((inet_sk(__sk)->daddr == (__saddr)) && \ |
| (inet_sk(__sk)->rcv_saddr == (__daddr)) && \ |
| ((*((__u32 *)&(inet_sk(__sk)->dport)))== (__ports)) && \ |
| (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif)))) |
| #define TCP_IPV4_TW_MATCH(__sk, __cookie, __saddr, __daddr, __ports, __dif)\ |
| ((tcptw_sk(__sk)->tw_daddr == (__saddr)) && \ |
| (tcptw_sk(__sk)->tw_rcv_saddr == (__daddr)) && \ |
| ((*((__u32 *)&(tcptw_sk(__sk)->tw_dport))) == (__ports)) && \ |
| (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif)))) |
| #endif /* 64-bit arch */ |
| |
| #define TCP_IPV6_MATCH(__sk, __saddr, __daddr, __ports, __dif) \ |
| (((*((__u32 *)&(inet_sk(__sk)->dport)))== (__ports)) && \ |
| ((__sk)->sk_family == AF_INET6) && \ |
| ipv6_addr_equal(&inet6_sk(__sk)->daddr, (__saddr)) && \ |
| ipv6_addr_equal(&inet6_sk(__sk)->rcv_saddr, (__daddr)) && \ |
| (!((__sk)->sk_bound_dev_if) || ((__sk)->sk_bound_dev_if == (__dif)))) |
| |
| /* These can have wildcards, don't try too hard. */ |
| static __inline__ int tcp_lhashfn(unsigned short num) |
| { |
| return num & (TCP_LHTABLE_SIZE - 1); |
| } |
| |
| static __inline__ int tcp_sk_listen_hashfn(struct sock *sk) |
| { |
| return tcp_lhashfn(inet_sk(sk)->num); |
| } |
| |
| #define MAX_TCP_HEADER (128 + MAX_HEADER) |
| |
| /* |
| * Never offer a window over 32767 without using window scaling. Some |
| * poor stacks do signed 16bit maths! |
| */ |
| #define MAX_TCP_WINDOW 32767U |
| |
| /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ |
| #define TCP_MIN_MSS 88U |
| |
| /* Minimal RCV_MSS. */ |
| #define TCP_MIN_RCVMSS 536U |
| |
| /* After receiving this amount of duplicate ACKs fast retransmit starts. */ |
| #define TCP_FASTRETRANS_THRESH 3 |
| |
| /* Maximal reordering. */ |
| #define TCP_MAX_REORDERING 127 |
| |
| /* Maximal number of ACKs sent quickly to accelerate slow-start. */ |
| #define TCP_MAX_QUICKACKS 16U |
| |
| /* urg_data states */ |
| #define TCP_URG_VALID 0x0100 |
| #define TCP_URG_NOTYET 0x0200 |
| #define TCP_URG_READ 0x0400 |
| |
| #define TCP_RETR1 3 /* |
| * This is how many retries it does before it |
| * tries to figure out if the gateway is |
| * down. Minimal RFC value is 3; it corresponds |
| * to ~3sec-8min depending on RTO. |
| */ |
| |
| #define TCP_RETR2 15 /* |
| * This should take at least |
| * 90 minutes to time out. |
| * RFC1122 says that the limit is 100 sec. |
| * 15 is ~13-30min depending on RTO. |
| */ |
| |
| #define TCP_SYN_RETRIES 5 /* number of times to retry active opening a |
| * connection: ~180sec is RFC minumum */ |
| |
| #define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a |
| * connection: ~180sec is RFC minumum */ |
| |
| |
| #define TCP_ORPHAN_RETRIES 7 /* number of times to retry on an orphaned |
| * socket. 7 is ~50sec-16min. |
| */ |
| |
| |
| #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT |
| * state, about 60 seconds */ |
| #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN |
| /* BSD style FIN_WAIT2 deadlock breaker. |
| * It used to be 3min, new value is 60sec, |
| * to combine FIN-WAIT-2 timeout with |
| * TIME-WAIT timer. |
| */ |
| |
| #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ |
| #if HZ >= 100 |
| #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */ |
| #define TCP_ATO_MIN ((unsigned)(HZ/25)) |
| #else |
| #define TCP_DELACK_MIN 4U |
| #define TCP_ATO_MIN 4U |
| #endif |
| #define TCP_RTO_MAX ((unsigned)(120*HZ)) |
| #define TCP_RTO_MIN ((unsigned)(HZ/5)) |
| #define TCP_TIMEOUT_INIT ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value */ |
| |
| #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes |
| * for local resources. |
| */ |
| |
| #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ |
| #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ |
| #define TCP_KEEPALIVE_INTVL (75*HZ) |
| |
| #define MAX_TCP_KEEPIDLE 32767 |
| #define MAX_TCP_KEEPINTVL 32767 |
| #define MAX_TCP_KEEPCNT 127 |
| #define MAX_TCP_SYNCNT 127 |
| |
| #define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */ |
| #define TCP_SYNQ_HSIZE 512 /* Size of SYNACK hash table */ |
| |
| #define TCP_PAWS_24DAYS (60 * 60 * 24 * 24) |
| #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated |
| * after this time. It should be equal |
| * (or greater than) TCP_TIMEWAIT_LEN |
| * to provide reliability equal to one |
| * provided by timewait state. |
| */ |
| #define TCP_PAWS_WINDOW 1 /* Replay window for per-host |
| * timestamps. It must be less than |
| * minimal timewait lifetime. |
| */ |
| |
| #define TCP_TW_RECYCLE_SLOTS_LOG 5 |
| #define TCP_TW_RECYCLE_SLOTS (1<<TCP_TW_RECYCLE_SLOTS_LOG) |
| |
| /* If time > 4sec, it is "slow" path, no recycling is required, |
| so that we select tick to get range about 4 seconds. |
| */ |
| |
| #if HZ <= 16 || HZ > 4096 |
| # error Unsupported: HZ <= 16 or HZ > 4096 |
| #elif HZ <= 32 |
| # define TCP_TW_RECYCLE_TICK (5+2-TCP_TW_RECYCLE_SLOTS_LOG) |
| #elif HZ <= 64 |
| # define TCP_TW_RECYCLE_TICK (6+2-TCP_TW_RECYCLE_SLOTS_LOG) |
| #elif HZ <= 128 |
| # define TCP_TW_RECYCLE_TICK (7+2-TCP_TW_RECYCLE_SLOTS_LOG) |
| #elif HZ <= 256 |
| # define TCP_TW_RECYCLE_TICK (8+2-TCP_TW_RECYCLE_SLOTS_LOG) |
| #elif HZ <= 512 |
| # define TCP_TW_RECYCLE_TICK (9+2-TCP_TW_RECYCLE_SLOTS_LOG) |
| #elif HZ <= 1024 |
| # define TCP_TW_RECYCLE_TICK (10+2-TCP_TW_RECYCLE_SLOTS_LOG) |
| #elif HZ <= 2048 |
| # define TCP_TW_RECYCLE_TICK (11+2-TCP_TW_RECYCLE_SLOTS_LOG) |
| #else |
| # define TCP_TW_RECYCLE_TICK (12+2-TCP_TW_RECYCLE_SLOTS_LOG) |
| #endif |
| /* |
| * TCP option |
| */ |
| |
| #define TCPOPT_NOP 1 /* Padding */ |
| #define TCPOPT_EOL 0 /* End of options */ |
| #define TCPOPT_MSS 2 /* Segment size negotiating */ |
| #define TCPOPT_WINDOW 3 /* Window scaling */ |
| #define TCPOPT_SACK_PERM 4 /* SACK Permitted */ |
| #define TCPOPT_SACK 5 /* SACK Block */ |
| #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ |
| |
| /* |
| * TCP option lengths |
| */ |
| |
| #define TCPOLEN_MSS 4 |
| #define TCPOLEN_WINDOW 3 |
| #define TCPOLEN_SACK_PERM 2 |
| #define TCPOLEN_TIMESTAMP 10 |
| |
| /* But this is what stacks really send out. */ |
| #define TCPOLEN_TSTAMP_ALIGNED 12 |
| #define TCPOLEN_WSCALE_ALIGNED 4 |
| #define TCPOLEN_SACKPERM_ALIGNED 4 |
| #define TCPOLEN_SACK_BASE 2 |
| #define TCPOLEN_SACK_BASE_ALIGNED 4 |
| #define TCPOLEN_SACK_PERBLOCK 8 |
| |
| #define TCP_TIME_RETRANS 1 /* Retransmit timer */ |
| #define TCP_TIME_DACK 2 /* Delayed ack timer */ |
| #define TCP_TIME_PROBE0 3 /* Zero window probe timer */ |
| #define TCP_TIME_KEEPOPEN 4 /* Keepalive timer */ |
| |
| /* Flags in tp->nonagle */ |
| #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */ |
| #define TCP_NAGLE_CORK 2 /* Socket is corked */ |
| #define TCP_NAGLE_PUSH 4 /* Cork is overriden for already queued data */ |
| |
| /* sysctl variables for tcp */ |
| extern int sysctl_tcp_timestamps; |
| extern int sysctl_tcp_window_scaling; |
| extern int sysctl_tcp_sack; |
| extern int sysctl_tcp_fin_timeout; |
| extern int sysctl_tcp_tw_recycle; |
| extern int sysctl_tcp_keepalive_time; |
| extern int sysctl_tcp_keepalive_probes; |
| extern int sysctl_tcp_keepalive_intvl; |
| extern int sysctl_tcp_syn_retries; |
| extern int sysctl_tcp_synack_retries; |
| extern int sysctl_tcp_retries1; |
| extern int sysctl_tcp_retries2; |
| extern int sysctl_tcp_orphan_retries; |
| extern int sysctl_tcp_syncookies; |
| extern int sysctl_tcp_retrans_collapse; |
| extern int sysctl_tcp_stdurg; |
| extern int sysctl_tcp_rfc1337; |
| extern int sysctl_tcp_abort_on_overflow; |
| extern int sysctl_tcp_max_orphans; |
| extern int sysctl_tcp_max_tw_buckets; |
| extern int sysctl_tcp_fack; |
| extern int sysctl_tcp_reordering; |
| extern int sysctl_tcp_ecn; |
| extern int sysctl_tcp_dsack; |
| extern int sysctl_tcp_mem[3]; |
| extern int sysctl_tcp_wmem[3]; |
| extern int sysctl_tcp_rmem[3]; |
| extern int sysctl_tcp_app_win; |
| extern int sysctl_tcp_adv_win_scale; |
| extern int sysctl_tcp_tw_reuse; |
| extern int sysctl_tcp_frto; |
| extern int sysctl_tcp_low_latency; |
| extern int sysctl_tcp_nometrics_save; |
| extern int sysctl_tcp_moderate_rcvbuf; |
| extern int sysctl_tcp_tso_win_divisor; |
| |
| extern atomic_t tcp_memory_allocated; |
| extern atomic_t tcp_sockets_allocated; |
| extern int tcp_memory_pressure; |
| |
| #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) |
| #define TCP_INET_FAMILY(fam) ((fam) == AF_INET) |
| #else |
| #define TCP_INET_FAMILY(fam) 1 |
| #endif |
| |
| /* |
| * Pointers to address related TCP functions |
| * (i.e. things that depend on the address family) |
| */ |
| |
| struct tcp_func { |
| int (*queue_xmit) (struct sk_buff *skb, |
| int ipfragok); |
| |
| void (*send_check) (struct sock *sk, |
| struct tcphdr *th, |
| int len, |
| struct sk_buff *skb); |
| |
| int (*rebuild_header) (struct sock *sk); |
| |
| int (*conn_request) (struct sock *sk, |
| struct sk_buff *skb); |
| |
| struct sock * (*syn_recv_sock) (struct sock *sk, |
| struct sk_buff *skb, |
| struct request_sock *req, |
| struct dst_entry *dst); |
| |
| int (*remember_stamp) (struct sock *sk); |
| |
| __u16 net_header_len; |
| |
| 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 *optlen); |
| |
| |
| void (*addr2sockaddr) (struct sock *sk, |
| struct sockaddr *); |
| |
| int sockaddr_len; |
| }; |
| |
| /* |
| * The next routines deal with comparing 32 bit unsigned ints |
| * and worry about wraparound (automatic with unsigned arithmetic). |
| */ |
| |
| static inline int before(__u32 seq1, __u32 seq2) |
| { |
| return (__s32)(seq1-seq2) < 0; |
| } |
| |
| static inline int after(__u32 seq1, __u32 seq2) |
| { |
| return (__s32)(seq2-seq1) < 0; |
| } |
| |
| |
| /* is s2<=s1<=s3 ? */ |
| static inline int between(__u32 seq1, __u32 seq2, __u32 seq3) |
| { |
| return seq3 - seq2 >= seq1 - seq2; |
| } |
| |
| |
| extern struct proto tcp_prot; |
| |
| DECLARE_SNMP_STAT(struct tcp_mib, tcp_statistics); |
| #define TCP_INC_STATS(field) SNMP_INC_STATS(tcp_statistics, field) |
| #define TCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(tcp_statistics, field) |
| #define TCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(tcp_statistics, field) |
| #define TCP_DEC_STATS(field) SNMP_DEC_STATS(tcp_statistics, field) |
| #define TCP_ADD_STATS_BH(field, val) SNMP_ADD_STATS_BH(tcp_statistics, field, val) |
| #define TCP_ADD_STATS_USER(field, val) SNMP_ADD_STATS_USER(tcp_statistics, field, val) |
| |
| extern void tcp_put_port(struct sock *sk); |
| extern void tcp_inherit_port(struct sock *sk, struct sock *child); |
| |
| extern void tcp_v4_err(struct sk_buff *skb, u32); |
| |
| extern void tcp_shutdown (struct sock *sk, int how); |
| |
| extern int tcp_v4_rcv(struct sk_buff *skb); |
| |
| extern int tcp_v4_remember_stamp(struct sock *sk); |
| |
| extern int tcp_v4_tw_remember_stamp(struct tcp_tw_bucket *tw); |
| |
| extern int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, |
| struct msghdr *msg, size_t size); |
| extern ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags); |
| |
| extern int tcp_ioctl(struct sock *sk, |
| int cmd, |
| unsigned long arg); |
| |
| extern int tcp_rcv_state_process(struct sock *sk, |
| struct sk_buff *skb, |
| struct tcphdr *th, |
| unsigned len); |
| |
| extern int tcp_rcv_established(struct sock *sk, |
| struct sk_buff *skb, |
| struct tcphdr *th, |
| unsigned len); |
| |
| extern void tcp_rcv_space_adjust(struct sock *sk); |
| |
| enum tcp_ack_state_t |
| { |
| TCP_ACK_SCHED = 1, |
| TCP_ACK_TIMER = 2, |
| TCP_ACK_PUSHED= 4 |
| }; |
| |
| static inline void tcp_schedule_ack(struct tcp_sock *tp) |
| { |
| tp->ack.pending |= TCP_ACK_SCHED; |
| } |
| |
| static inline int tcp_ack_scheduled(struct tcp_sock *tp) |
| { |
| return tp->ack.pending&TCP_ACK_SCHED; |
| } |
| |
| static __inline__ void tcp_dec_quickack_mode(struct tcp_sock *tp) |
| { |
| if (tp->ack.quick && --tp->ack.quick == 0) { |
| /* Leaving quickack mode we deflate ATO. */ |
| tp->ack.ato = TCP_ATO_MIN; |
| } |
| } |
| |
| extern void tcp_enter_quickack_mode(struct tcp_sock *tp); |
| |
| static __inline__ void tcp_delack_init(struct tcp_sock *tp) |
| { |
| memset(&tp->ack, 0, sizeof(tp->ack)); |
| } |
| |
| static inline void tcp_clear_options(struct tcp_options_received *rx_opt) |
| { |
| rx_opt->tstamp_ok = rx_opt->sack_ok = rx_opt->wscale_ok = rx_opt->snd_wscale = 0; |
| } |
| |
| enum tcp_tw_status |
| { |
| TCP_TW_SUCCESS = 0, |
| TCP_TW_RST = 1, |
| TCP_TW_ACK = 2, |
| TCP_TW_SYN = 3 |
| }; |
| |
| |
| extern enum tcp_tw_status tcp_timewait_state_process(struct tcp_tw_bucket *tw, |
| struct sk_buff *skb, |
| struct tcphdr *th, |
| unsigned len); |
| |
| extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb, |
| struct request_sock *req, |
| struct request_sock **prev); |
| extern int tcp_child_process(struct sock *parent, |
| struct sock *child, |
| struct sk_buff *skb); |
| extern void tcp_enter_frto(struct sock *sk); |
| extern void tcp_enter_loss(struct sock *sk, int how); |
| extern void tcp_clear_retrans(struct tcp_sock *tp); |
| extern void tcp_update_metrics(struct sock *sk); |
| |
| extern void tcp_close(struct sock *sk, |
| long timeout); |
| extern struct sock * tcp_accept(struct sock *sk, int flags, int *err); |
| extern unsigned int tcp_poll(struct file * file, struct socket *sock, struct poll_table_struct *wait); |
| |
| extern int tcp_getsockopt(struct sock *sk, int level, |
| int optname, |
| char __user *optval, |
| int __user *optlen); |
| extern int tcp_setsockopt(struct sock *sk, int level, |
| int optname, char __user *optval, |
| int optlen); |
| extern void tcp_set_keepalive(struct sock *sk, int val); |
| extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, |
| struct msghdr *msg, |
| size_t len, int nonblock, |
| int flags, int *addr_len); |
| |
| extern int tcp_listen_start(struct sock *sk); |
| |
| extern void tcp_parse_options(struct sk_buff *skb, |
| struct tcp_options_received *opt_rx, |
| int estab); |
| |
| /* |
| * TCP v4 functions exported for the inet6 API |
| */ |
| |
| extern int tcp_v4_rebuild_header(struct sock *sk); |
| |
| extern int tcp_v4_build_header(struct sock *sk, |
| struct sk_buff *skb); |
| |
| extern void tcp_v4_send_check(struct sock *sk, |
| struct tcphdr *th, int len, |
| struct sk_buff *skb); |
| |
| extern int tcp_v4_conn_request(struct sock *sk, |
| struct sk_buff *skb); |
| |
| extern struct sock * tcp_create_openreq_child(struct sock *sk, |
| struct request_sock *req, |
| struct sk_buff *skb); |
| |
| extern struct sock * tcp_v4_syn_recv_sock(struct sock *sk, |
| struct sk_buff *skb, |
| struct request_sock *req, |
| struct dst_entry *dst); |
| |
| extern int tcp_v4_do_rcv(struct sock *sk, |
| struct sk_buff *skb); |
| |
| extern int tcp_v4_connect(struct sock *sk, |
| struct sockaddr *uaddr, |
| int addr_len); |
| |
| extern int tcp_connect(struct sock *sk); |
| |
| extern struct sk_buff * tcp_make_synack(struct sock *sk, |
| struct dst_entry *dst, |
| struct request_sock *req); |
| |
| extern int tcp_disconnect(struct sock *sk, int flags); |
| |
| extern void tcp_unhash(struct sock *sk); |
| |
| extern int tcp_v4_hash_connecting(struct sock *sk); |
| |
| |
| /* From syncookies.c */ |
| extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb, |
| struct ip_options *opt); |
| extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, |
| __u16 *mss); |
| |
| /* tcp_output.c */ |
| |
| extern int tcp_write_xmit(struct sock *, int nonagle); |
| extern int tcp_retransmit_skb(struct sock *, struct sk_buff *); |
| extern void tcp_xmit_retransmit_queue(struct sock *); |
| extern void tcp_simple_retransmit(struct sock *); |
| extern int tcp_trim_head(struct sock *, struct sk_buff *, u32); |
| |
| extern void tcp_send_probe0(struct sock *); |
| extern void tcp_send_partial(struct sock *); |
| extern int tcp_write_wakeup(struct sock *); |
| extern void tcp_send_fin(struct sock *sk); |
| extern void tcp_send_active_reset(struct sock *sk, int priority); |
| extern int tcp_send_synack(struct sock *); |
| extern void tcp_push_one(struct sock *, unsigned mss_now); |
| extern void tcp_send_ack(struct sock *sk); |
| extern void tcp_send_delayed_ack(struct sock *sk); |
| |
| /* tcp_timer.c */ |
| extern void tcp_init_xmit_timers(struct sock *); |
| extern void tcp_clear_xmit_timers(struct sock *); |
| |
| extern void tcp_delete_keepalive_timer(struct sock *); |
| extern void tcp_reset_keepalive_timer(struct sock *, unsigned long); |
| extern unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); |
| extern unsigned int tcp_current_mss(struct sock *sk, int large); |
| |
| #ifdef TCP_DEBUG |
| extern const char tcp_timer_bug_msg[]; |
| #endif |
| |
| /* tcp_diag.c */ |
| extern void tcp_get_info(struct sock *, struct tcp_info *); |
| |
| /* Read 'sendfile()'-style from a TCP socket */ |
| typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *, |
| unsigned int, size_t); |
| extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, |
| sk_read_actor_t recv_actor); |
| |
| static inline void tcp_clear_xmit_timer(struct sock *sk, int what) |
| { |
| struct tcp_sock *tp = tcp_sk(sk); |
| |
| switch (what) { |
| case TCP_TIME_RETRANS: |
| case TCP_TIME_PROBE0: |
| tp->pending = 0; |
| |
| #ifdef TCP_CLEAR_TIMERS |
| sk_stop_timer(sk, &tp->retransmit_timer); |
| #endif |
| break; |
| case TCP_TIME_DACK: |
| tp->ack.blocked = 0; |
| tp->ack.pending = 0; |
| |
| #ifdef TCP_CLEAR_TIMERS |
| sk_stop_timer(sk, &tp->delack_timer); |
| #endif |
| break; |
| default: |
| #ifdef TCP_DEBUG |
| printk(tcp_timer_bug_msg); |
| #endif |
| return; |
| }; |
| |
| } |
| |
| /* |
| * Reset the retransmission timer |
| */ |
| static inline void tcp_reset_xmit_timer(struct sock *sk, int what, unsigned long when) |
| { |
| struct tcp_sock *tp = tcp_sk(sk); |
| |
| if (when > TCP_RTO_MAX) { |
| #ifdef TCP_DEBUG |
| printk(KERN_DEBUG "reset_xmit_timer sk=%p %d when=0x%lx, caller=%p\n", sk, what, when, current_text_addr()); |
| #endif |
| when = TCP_RTO_MAX; |
| } |
| |
| switch (what) { |
| case TCP_TIME_RETRANS: |
| case TCP_TIME_PROBE0: |
| tp->pending = what; |
| tp->timeout = jiffies+when; |
| sk_reset_timer(sk, &tp->retransmit_timer, tp->timeout); |
| break; |
| |
| case TCP_TIME_DACK: |
| tp->ack.pending |= TCP_ACK_TIMER; |
| tp->ack.timeout = jiffies+when; |
| sk_reset_timer(sk, &tp->delack_timer, tp->ack.timeout); |
| break; |
| |
| default: |
| #ifdef TCP_DEBUG |
| printk(tcp_timer_bug_msg); |
| #endif |
| return; |
| }; |
| } |
| |
| /* Initialize RCV_MSS value. |
| * RCV_MSS is an our guess about MSS used by the peer. |
| * We haven't any direct information about the MSS. |
| * It's better to underestimate the RCV_MSS rather than overestimate. |
| * Overestimations make us ACKing less frequently than needed. |
| * Underestimations are more easy to detect and fix by tcp_measure_rcv_mss(). |
| */ |
| |
| static inline void tcp_initialize_rcv_mss(struct sock *sk) |
| { |
| struct tcp_sock *tp = tcp_sk(sk); |
| unsigned int hint = min(tp->advmss, tp->mss_cache_std); |
| |
| hint = min(hint, tp->rcv_wnd/2); |
| hint = min(hint, TCP_MIN_RCVMSS); |
| hint = max(hint, TCP_MIN_MSS); |
| |
| tp->ack.rcv_mss = hint; |
| } |
| |
| static __inline__ void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) |
| { |
| tp->pred_flags = htonl((tp->tcp_header_len << 26) | |
| ntohl(TCP_FLAG_ACK) | |
| snd_wnd); |
| } |
| |
| static __inline__ void tcp_fast_path_on(struct tcp_sock *tp) |
| { |
| __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale); |
| } |
| |
| static inline void tcp_fast_path_check(struct sock *sk, struct tcp_sock *tp) |
| { |
| if (skb_queue_len(&tp->out_of_order_queue) == 0 && |
| tp->rcv_wnd && |
| atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf && |
| !tp->urg_data) |
| tcp_fast_path_on(tp); |
| } |
| |
| /* Compute the actual receive window we are currently advertising. |
| * Rcv_nxt can be after the window if our peer push more data |
| * than the offered window. |
| */ |
| static __inline__ u32 tcp_receive_window(const struct tcp_sock *tp) |
| { |
| s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt; |
| |
| if (win < 0) |
| win = 0; |
| return (u32) win; |
| } |
| |
| /* Choose a new window, without checks for shrinking, and without |
| * scaling applied to the result. The caller does these things |
| * if necessary. This is a "raw" window selection. |
| */ |
| extern u32 __tcp_select_window(struct sock *sk); |
| |
| /* TCP timestamps are only 32-bits, this causes a slight |
| * complication on 64-bit systems since we store a snapshot |
| * of jiffies in the buffer control blocks below. We decidely |
| * only use of the low 32-bits of jiffies and hide the ugly |
| * casts with the following macro. |
| */ |
| #define tcp_time_stamp ((__u32)(jiffies)) |
| |
| /* This is what the send packet queueing engine uses to pass |
| * TCP per-packet control information to the transmission |
| * code. We also store the host-order sequence numbers in |
| * here too. This is 36 bytes on 32-bit architectures, |
| * 40 bytes on 64-bit machines, if this grows please adjust |
| * skbuff.h:skbuff->cb[xxx] size appropriately. |
| */ |
| struct tcp_skb_cb { |
| union { |
| struct inet_skb_parm h4; |
| #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) |
| struct inet6_skb_parm h6; |
| #endif |
| } header; /* For incoming frames */ |
| __u32 seq; /* Starting sequence number */ |
| __u32 end_seq; /* SEQ + FIN + SYN + datalen */ |
| __u32 when; /* used to compute rtt's */ |
| __u8 flags; /* TCP header flags. */ |
| |
| /* NOTE: These must match up to the flags byte in a |
| * real TCP header. |
| */ |
| #define TCPCB_FLAG_FIN 0x01 |
| #define TCPCB_FLAG_SYN 0x02 |
| #define TCPCB_FLAG_RST 0x04 |
| #define TCPCB_FLAG_PSH 0x08 |
| #define TCPCB_FLAG_ACK 0x10 |
| #define TCPCB_FLAG_URG 0x20 |
| #define TCPCB_FLAG_ECE 0x40 |
| #define TCPCB_FLAG_CWR 0x80 |
| |
| __u8 sacked; /* State flags for SACK/FACK. */ |
| #define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */ |
| #define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */ |
| #define TCPCB_LOST 0x04 /* SKB is lost */ |
| #define TCPCB_TAGBITS 0x07 /* All tag bits */ |
| |
| #define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */ |
| #define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS) |
| |
| #define TCPCB_URG 0x20 /* Urgent pointer advenced here */ |
| |
| #define TCPCB_AT_TAIL (TCPCB_URG) |
| |
| __u16 urg_ptr; /* Valid w/URG flags is set. */ |
| __u32 ack_seq; /* Sequence number ACK'd */ |
| }; |
| |
| #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) |
| |
| #include <net/tcp_ecn.h> |
| |
| /* Due to TSO, an SKB can be composed of multiple actual |
| * packets. To keep these tracked properly, we use this. |
| */ |
| static inline int tcp_skb_pcount(const struct sk_buff *skb) |
| { |
| return skb_shinfo(skb)->tso_segs; |
| } |
| |
| /* This is valid iff tcp_skb_pcount() > 1. */ |
| static inline int tcp_skb_mss(const struct sk_buff *skb) |
| { |
| return skb_shinfo(skb)->tso_size; |
| } |
| |
| static inline void tcp_dec_pcount_approx(__u32 *count, |
| const struct sk_buff *skb) |
| { |
| if (*count) { |
| *count -= tcp_skb_pcount(skb); |
| if ((int)*count < 0) |
| *count = 0; |
| } |
| } |
| |
| static inline void tcp_packets_out_inc(struct sock *sk, |
| struct tcp_sock *tp, |
| const struct sk_buff *skb) |
| { |
| int orig = tp->packets_out; |
| |
| tp->packets_out += tcp_skb_pcount(skb); |
| if (!orig) |
| tcp_reset_xmit_timer(sk, TCP_TIME_RETRANS, tp->rto); |
| } |
| |
| static inline void tcp_packets_out_dec(struct tcp_sock *tp, |
| const struct sk_buff *skb) |
| { |
| tp->packets_out -= tcp_skb_pcount(skb); |
| } |
| |
| /* Events passed to congestion control interface */ |
| enum tcp_ca_event { |
| CA_EVENT_TX_START, /* first transmit when no packets in flight */ |
| CA_EVENT_CWND_RESTART, /* congestion window restart */ |
| CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ |
| CA_EVENT_FRTO, /* fast recovery timeout */ |
| CA_EVENT_LOSS, /* loss timeout */ |
| CA_EVENT_FAST_ACK, /* in sequence ack */ |
| CA_EVENT_SLOW_ACK, /* other ack */ |
| }; |
| |
| /* |
| * Interface for adding new TCP congestion control handlers |
| */ |
| #define TCP_CA_NAME_MAX 16 |
| struct tcp_congestion_ops { |
| struct list_head list; |
| |
| /* initialize private data (optional) */ |
| void (*init)(struct tcp_sock *tp); |
| /* cleanup private data (optional) */ |
| void (*release)(struct tcp_sock *tp); |
| |
| /* return slow start threshold (required) */ |
| u32 (*ssthresh)(struct tcp_sock *tp); |
| /* lower bound for congestion window (optional) */ |
| u32 (*min_cwnd)(struct tcp_sock *tp); |
| /* do new cwnd calculation (required) */ |
| void (*cong_avoid)(struct tcp_sock *tp, u32 ack, |
| u32 rtt, u32 in_flight, int good_ack); |
| /* round trip time sample per acked packet (optional) */ |
| void (*rtt_sample)(struct tcp_sock *tp, u32 usrtt); |
| /* call before changing ca_state (optional) */ |
| void (*set_state)(struct tcp_sock *tp, u8 new_state); |
| /* call when cwnd event occurs (optional) */ |
| void (*cwnd_event)(struct tcp_sock *tp, enum tcp_ca_event ev); |
| /* new value of cwnd after loss (optional) */ |
| u32 (*undo_cwnd)(struct tcp_sock *tp); |
| /* hook for packet ack accounting (optional) */ |
| void (*pkts_acked)(struct tcp_sock *tp, u32 num_acked); |
| /* get info for tcp_diag (optional) */ |
| void (*get_info)(struct tcp_sock *tp, u32 ext, struct sk_buff *skb); |
| |
| char name[TCP_CA_NAME_MAX]; |
| struct module *owner; |
| }; |
| |
| extern int tcp_register_congestion_control(struct tcp_congestion_ops *type); |
| extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); |
| |
| extern void tcp_init_congestion_control(struct tcp_sock *tp); |
| extern void tcp_cleanup_congestion_control(struct tcp_sock *tp); |
| extern int tcp_set_default_congestion_control(const char *name); |
| extern void tcp_get_default_congestion_control(char *name); |
| |
| extern struct tcp_congestion_ops tcp_reno; |
| extern u32 tcp_reno_ssthresh(struct tcp_sock *tp); |
| extern void tcp_reno_cong_avoid(struct tcp_sock *tp, u32 ack, |
| u32 rtt, u32 in_flight, int flag); |
| extern u32 tcp_reno_min_cwnd(struct tcp_sock *tp); |
| |
| static inline void tcp_set_ca_state(struct tcp_sock *tp, u8 ca_state) |
| { |
| if (tp->ca_ops->set_state) |
| tp->ca_ops->set_state(tp, ca_state); |
| tp->ca_state = ca_state; |
| } |
| |
| static inline void tcp_ca_event(struct tcp_sock *tp, enum tcp_ca_event event) |
| { |
| if (tp->ca_ops->cwnd_event) |
| tp->ca_ops->cwnd_event(tp, event); |
| } |
| |
| /* This determines how many packets are "in the network" to the best |
| * of our knowledge. In many cases it is conservative, but where |
| * detailed information is available from the receiver (via SACK |
| * blocks etc.) we can make more aggressive calculations. |
| * |
| * Use this for decisions involving congestion control, use just |
| * tp->packets_out to determine if the send queue is empty or not. |
| * |
| * Read this equation as: |
| * |
| * "Packets sent once on transmission queue" MINUS |
| * "Packets left network, but not honestly ACKed yet" PLUS |
| * "Packets fast retransmitted" |
| */ |
| static __inline__ unsigned int tcp_packets_in_flight(const struct tcp_sock *tp) |
| { |
| return (tp->packets_out - tp->left_out + tp->retrans_out); |
| } |
| |
| /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. |
| * The exception is rate halving phase, when cwnd is decreasing towards |
| * ssthresh. |
| */ |
| static inline __u32 tcp_current_ssthresh(struct tcp_sock *tp) |
| { |
| if ((1<<tp->ca_state)&(TCPF_CA_CWR|TCPF_CA_Recovery)) |
| return tp->snd_ssthresh; |
| else |
| return max(tp->snd_ssthresh, |
| ((tp->snd_cwnd >> 1) + |
| (tp->snd_cwnd >> 2))); |
| } |
| |
| static inline void tcp_sync_left_out(struct tcp_sock *tp) |
| { |
| if (tp->rx_opt.sack_ok && |
| (tp->sacked_out >= tp->packets_out - tp->lost_out)) |
| tp->sacked_out = tp->packets_out - tp->lost_out; |
| tp->left_out = tp->sacked_out + tp->lost_out; |
| } |
| |
| extern void tcp_cwnd_application_limited(struct sock *sk); |
| |
| /* Congestion window validation. (RFC2861) */ |
| |
| static inline void tcp_cwnd_validate(struct sock *sk, struct tcp_sock *tp) |
| { |
| __u32 packets_out = tp->packets_out; |
| |
| if (packets_out >= tp->snd_cwnd) { |
| /* Network is feed fully. */ |
| tp->snd_cwnd_used = 0; |
| tp->snd_cwnd_stamp = tcp_time_stamp; |
| } else { |
| /* Network starves. */ |
| if (tp->packets_out > tp->snd_cwnd_used) |
| tp->snd_cwnd_used = tp->packets_out; |
| |
| if ((s32)(tcp_time_stamp - tp->snd_cwnd_stamp) >= tp->rto) |
| tcp_cwnd_application_limited(sk); |
| } |
| } |
| |
| /* Set slow start threshould and cwnd not falling to slow start */ |
| static inline void __tcp_enter_cwr(struct tcp_sock *tp) |
| { |
| tp->undo_marker = 0; |
| tp->snd_ssthresh = tp->ca_ops->ssthresh(tp); |
| tp->snd_cwnd = min(tp->snd_cwnd, |
| tcp_packets_in_flight(tp) + 1U); |
| tp->snd_cwnd_cnt = 0; |
| tp->high_seq = tp->snd_nxt; |
| tp->snd_cwnd_stamp = tcp_time_stamp; |
| TCP_ECN_queue_cwr(tp); |
| } |
| |
| static inline void tcp_enter_cwr(struct tcp_sock *tp) |
| { |
| tp->prior_ssthresh = 0; |
| if (tp->ca_state < TCP_CA_CWR) { |
| __tcp_enter_cwr(tp); |
| tcp_set_ca_state(tp, TCP_CA_CWR); |
| } |
| } |
| |
| extern __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst); |
| |
| /* Slow start with delack produces 3 packets of burst, so that |
| * it is safe "de facto". |
| */ |
| static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp) |
| { |
| return 3; |
| } |
| |
| static __inline__ int tcp_minshall_check(const struct tcp_sock *tp) |
| { |
| return after(tp->snd_sml,tp->snd_una) && |
| !after(tp->snd_sml, tp->snd_nxt); |
| } |
| |
| static __inline__ void tcp_minshall_update(struct tcp_sock *tp, int mss, |
| const struct sk_buff *skb) |
| { |
| if (skb->len < mss) |
| tp->snd_sml = TCP_SKB_CB(skb)->end_seq; |
| } |
| |
| /* Return 0, if packet can be sent now without violation Nagle's rules: |
| 1. It is full sized. |
| 2. Or it contains FIN. |
| 3. Or TCP_NODELAY was set. |
| 4. Or TCP_CORK is not set, and all sent packets are ACKed. |
| With Minshall's modification: all sent small packets are ACKed. |
| */ |
| |
| static __inline__ int |
| tcp_nagle_check(const struct tcp_sock *tp, const struct sk_buff *skb, |
| unsigned mss_now, int nonagle) |
| { |
| return (skb->len < mss_now && |
| !(TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN) && |
| ((nonagle&TCP_NAGLE_CORK) || |
| (!nonagle && |
| tp->packets_out && |
| tcp_minshall_check(tp)))); |
| } |
| |
| extern void tcp_set_skb_tso_segs(struct sock *, struct sk_buff *); |
| |
| /* This checks if the data bearing packet SKB (usually sk->sk_send_head) |
| * should be put on the wire right now. |
| */ |
| static __inline__ int tcp_snd_test(struct sock *sk, |
| struct sk_buff *skb, |
| unsigned cur_mss, int nonagle) |
| { |
| struct tcp_sock *tp = tcp_sk(sk); |
| int pkts = tcp_skb_pcount(skb); |
| |
| if (!pkts) { |
| tcp_set_skb_tso_segs(sk, skb); |
| pkts = tcp_skb_pcount(skb); |
| } |
| |
| /* RFC 1122 - section 4.2.3.4 |
| * |
| * We must queue if |
| * |
| * a) The right edge of this frame exceeds the window |
| * b) There are packets in flight and we have a small segment |
| * [SWS avoidance and Nagle algorithm] |
| * (part of SWS is done on packetization) |
| * Minshall version sounds: there are no _small_ |
| * segments in flight. (tcp_nagle_check) |
| * c) We have too many packets 'in flight' |
| * |
| * Don't use the nagle rule for urgent data (or |
| * for the final FIN -DaveM). |
| * |
| * Also, Nagle rule does not apply to frames, which |
| * sit in the middle of queue (they have no chances |
| * to get new data) and if room at tail of skb is |
| * not enough to save something seriously (<32 for now). |
| */ |
| |
| /* Don't be strict about the congestion window for the |
| * final FIN frame. -DaveM |
| */ |
| return (((nonagle&TCP_NAGLE_PUSH) || tp->urg_mode |
| || !tcp_nagle_check(tp, skb, cur_mss, nonagle)) && |
| (((tcp_packets_in_flight(tp) + (pkts-1)) < tp->snd_cwnd) || |
| (TCP_SKB_CB(skb)->flags & TCPCB_FLAG_FIN)) && |
| !after(TCP_SKB_CB(skb)->end_seq, tp->snd_una + tp->snd_wnd)); |
| } |
| |
| static __inline__ void tcp_check_probe_timer(struct sock *sk, struct tcp_sock *tp) |
| { |
| if (!tp->packets_out && !tp->pending) |
| tcp_reset_xmit_timer(sk, TCP_TIME_PROBE0, tp->rto); |
| } |
| |
| static __inline__ int tcp_skb_is_last(const struct sock *sk, |
| const struct sk_buff *skb) |
| { |
| return skb->next == (struct sk_buff *)&sk->sk_write_queue; |
| } |
| |
| /* Push out any pending frames which were held back due to |
| * TCP_CORK or attempt at coalescing tiny packets. |
| * The socket must be locked by the caller. |
| */ |
| static __inline__ void __tcp_push_pending_frames(struct sock *sk, |
| struct tcp_sock *tp, |
| unsigned cur_mss, |
| int nonagle) |
| { |
| struct sk_buff *skb = sk->sk_send_head; |
| |
| if (skb) { |
| if (!tcp_skb_is_last(sk, skb)) |
| nonagle = TCP_NAGLE_PUSH; |
| if (!tcp_snd_test(sk, skb, cur_mss, nonagle) || |
| tcp_write_xmit(sk, nonagle)) |
| tcp_check_probe_timer(sk, tp); |
| } |
| tcp_cwnd_validate(sk, tp); |
| } |
| |
| static __inline__ void tcp_push_pending_frames(struct sock *sk, |
| struct tcp_sock *tp) |
| { |
| __tcp_push_pending_frames(sk, tp, tcp_current_mss(sk, 1), tp->nonagle); |
| } |
| |
| static __inline__ int tcp_may_send_now(struct sock *sk, struct tcp_sock *tp) |
| { |
| struct sk_buff *skb = sk->sk_send_head; |
| |
| return (skb && |
| tcp_snd_test(sk, skb, tcp_current_mss(sk, 1), |
| tcp_skb_is_last(sk, skb) ? TCP_NAGLE_PUSH : tp->nonagle)); |
| } |
| |
| static __inline__ void tcp_init_wl(struct tcp_sock *tp, u32 ack, u32 seq) |
| { |
| tp->snd_wl1 = seq; |
| } |
| |
| static __inline__ void tcp_update_wl(struct tcp_sock *tp, u32 ack, u32 seq) |
| { |
| tp->snd_wl1 = seq; |
| } |
| |
| extern void tcp_destroy_sock(struct sock *sk); |
| |
| |
| /* |
| * Calculate(/check) TCP checksum |
| */ |
| static __inline__ u16 tcp_v4_check(struct tcphdr *th, int len, |
| unsigned long saddr, unsigned long daddr, |
| unsigned long base) |
| { |
| return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base); |
| } |
| |
| static __inline__ int __tcp_checksum_complete(struct sk_buff *skb) |
| { |
| return (unsigned short)csum_fold(skb_checksum(skb, 0, skb->len, skb->csum)); |
| } |
| |
| static __inline__ int tcp_checksum_complete(struct sk_buff *skb) |
| { |
| return skb->ip_summed != CHECKSUM_UNNECESSARY && |
| __tcp_checksum_complete(skb); |
| } |
| |
| /* Prequeue for VJ style copy to user, combined with checksumming. */ |
| |
| static __inline__ void tcp_prequeue_init(struct tcp_sock *tp) |
| { |
| tp->ucopy.task = NULL; |
| tp->ucopy.len = 0; |
| tp->ucopy.memory = 0; |
| skb_queue_head_init(&tp->ucopy.prequeue); |
| } |
| |
| /* Packet is added to VJ-style prequeue for processing in process |
| * context, if a reader task is waiting. Apparently, this exciting |
| * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93) |
| * failed somewhere. Latency? Burstiness? Well, at least now we will |
| * see, why it failed. 8)8) --ANK |
| * |
| * NOTE: is this not too big to inline? |
| */ |
| static __inline__ int tcp_prequeue(struct sock *sk, struct sk_buff *skb) |
| { |
| struct tcp_sock *tp = tcp_sk(sk); |
| |
| if (!sysctl_tcp_low_latency && tp->ucopy.task) { |
| __skb_queue_tail(&tp->ucopy.prequeue, skb); |
| tp->ucopy.memory += skb->truesize; |
| if (tp->ucopy.memory > sk->sk_rcvbuf) { |
| struct sk_buff *skb1; |
| |
| BUG_ON(sock_owned_by_user(sk)); |
| |
| while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) { |
| sk->sk_backlog_rcv(sk, skb1); |
| NET_INC_STATS_BH(LINUX_MIB_TCPPREQUEUEDROPPED); |
| } |
| |
| tp->ucopy.memory = 0; |
| } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) { |
| wake_up_interruptible(sk->sk_sleep); |
| if (!tcp_ack_scheduled(tp)) |
| tcp_reset_xmit_timer(sk, TCP_TIME_DACK, (3*TCP_RTO_MIN)/4); |
| } |
| return 1; |
| } |
| return 0; |
| } |
| |
| |
| #undef STATE_TRACE |
| |
| #ifdef STATE_TRACE |
| static const char *statename[]={ |
| "Unused","Established","Syn Sent","Syn Recv", |
| "Fin Wait 1","Fin Wait 2","Time Wait", "Close", |
| "Close Wait","Last ACK","Listen","Closing" |
| }; |
| #endif |
| |
| static __inline__ void tcp_set_state(struct sock *sk, int state) |
| { |
| int oldstate = sk->sk_state; |
| |
| switch (state) { |
| case TCP_ESTABLISHED: |
| if (oldstate != TCP_ESTABLISHED) |
| TCP_INC_STATS(TCP_MIB_CURRESTAB); |
| break; |
| |
| case TCP_CLOSE: |
| if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) |
| TCP_INC_STATS(TCP_MIB_ESTABRESETS); |
| |
| sk->sk_prot->unhash(sk); |
| if (tcp_sk(sk)->bind_hash && |
| !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) |
| tcp_put_port(sk); |
| /* fall through */ |
| default: |
| if (oldstate==TCP_ESTABLISHED) |
| TCP_DEC_STATS(TCP_MIB_CURRESTAB); |
| } |
| |
| /* Change state AFTER socket is unhashed to avoid closed |
| * socket sitting in hash tables. |
| */ |
| sk->sk_state = state; |
| |
| #ifdef STATE_TRACE |
| SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n",sk, statename[oldstate],statename[state]); |
| #endif |
| } |
| |
| static __inline__ void tcp_done(struct sock *sk) |
| { |
| tcp_set_state(sk, TCP_CLOSE); |
| tcp_clear_xmit_timers(sk); |
| |
| sk->sk_shutdown = SHUTDOWN_MASK; |
| |
| if (!sock_flag(sk, SOCK_DEAD)) |
| sk->sk_state_change(sk); |
| else |
| tcp_destroy_sock(sk); |
| } |
| |
| static __inline__ void tcp_sack_reset(struct tcp_options_received *rx_opt) |
| { |
| rx_opt->dsack = 0; |
| rx_opt->eff_sacks = 0; |
| rx_opt->num_sacks = 0; |
| } |
| |
| static __inline__ void tcp_build_and_update_options(__u32 *ptr, struct tcp_sock *tp, __u32 tstamp) |
| { |
| if (tp->rx_opt.tstamp_ok) { |
| *ptr++ = __constant_htonl((TCPOPT_NOP << 24) | |
| (TCPOPT_NOP << 16) | |
| (TCPOPT_TIMESTAMP << 8) | |
| TCPOLEN_TIMESTAMP); |
| *ptr++ = htonl(tstamp); |
| *ptr++ = htonl(tp->rx_opt.ts_recent); |
| } |
| if (tp->rx_opt.eff_sacks) { |
| struct tcp_sack_block *sp = tp->rx_opt.dsack ? tp->duplicate_sack : tp->selective_acks; |
| int this_sack; |
| |
| *ptr++ = __constant_htonl((TCPOPT_NOP << 24) | |
| (TCPOPT_NOP << 16) | |
| (TCPOPT_SACK << 8) | |
| (TCPOLEN_SACK_BASE + |
| (tp->rx_opt.eff_sacks * TCPOLEN_SACK_PERBLOCK))); |
| for(this_sack = 0; this_sack < tp->rx_opt.eff_sacks; this_sack++) { |
| *ptr++ = htonl(sp[this_sack].start_seq); |
| *ptr++ = htonl(sp[this_sack].end_seq); |
| } |
| if (tp->rx_opt.dsack) { |
| tp->rx_opt.dsack = 0; |
| tp->rx_opt.eff_sacks--; |
| } |
| } |
| } |
| |
| /* Construct a tcp options header for a SYN or SYN_ACK packet. |
| * If this is every changed make sure to change the definition of |
| * MAX_SYN_SIZE to match the new maximum number of options that you |
| * can generate. |
| */ |
| static inline void tcp_syn_build_options(__u32 *ptr, int mss, int ts, int sack, |
| int offer_wscale, int wscale, __u32 tstamp, __u32 ts_recent) |
| { |
| /* We always get an MSS option. |
| * The option bytes which will be seen in normal data |
| * packets should timestamps be used, must be in the MSS |
| * advertised. But we subtract them from tp->mss_cache so |
| * that calculations in tcp_sendmsg are simpler etc. |
| * So account for this fact here if necessary. If we |
| * don't do this correctly, as a receiver we won't |
| * recognize data packets as being full sized when we |
| * should, and thus we won't abide by the delayed ACK |
| * rules correctly. |
| * SACKs don't matter, we never delay an ACK when we |
| * have any of those going out. |
| */ |
| *ptr++ = htonl((TCPOPT_MSS << 24) | (TCPOLEN_MSS << 16) | mss); |
| if (ts) { |
| if(sack) |
| *ptr++ = __constant_htonl((TCPOPT_SACK_PERM << 24) | (TCPOLEN_SACK_PERM << 16) | |
| (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP); |
| else |
| *ptr++ = __constant_htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | |
| (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP); |
| *ptr++ = htonl(tstamp); /* TSVAL */ |
| *ptr++ = htonl(ts_recent); /* TSECR */ |
| } else if(sack) |
| *ptr++ = __constant_htonl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | |
| (TCPOPT_SACK_PERM << 8) | TCPOLEN_SACK_PERM); |
| if (offer_wscale) |
| *ptr++ = htonl((TCPOPT_NOP << 24) | (TCPOPT_WINDOW << 16) | (TCPOLEN_WINDOW << 8) | (wscale)); |
| } |
| |
| /* Determine a window scaling and initial window to offer. */ |
| extern void tcp_select_initial_window(int __space, __u32 mss, |
| __u32 *rcv_wnd, __u32 *window_clamp, |
| int wscale_ok, __u8 *rcv_wscale); |
| |
| static inline int tcp_win_from_space(int space) |
| { |
| return sysctl_tcp_adv_win_scale<=0 ? |
| (space>>(-sysctl_tcp_adv_win_scale)) : |
| space - (space>>sysctl_tcp_adv_win_scale); |
| } |
| |
| /* Note: caller must be prepared to deal with negative returns */ |
| static inline int tcp_space(const struct sock *sk) |
| { |
| return tcp_win_from_space(sk->sk_rcvbuf - |
| atomic_read(&sk->sk_rmem_alloc)); |
| } |
| |
| static inline int tcp_full_space(const struct sock *sk) |
| { |
| return tcp_win_from_space(sk->sk_rcvbuf); |
| } |
| |
| static inline void tcp_acceptq_queue(struct sock *sk, struct request_sock *req, |
| struct sock *child) |
| { |
| reqsk_queue_add(&tcp_sk(sk)->accept_queue, req, sk, child); |
| } |
| |
| static inline void |
| tcp_synq_removed(struct sock *sk, struct request_sock *req) |
| { |
| if (reqsk_queue_removed(&tcp_sk(sk)->accept_queue, req) == 0) |
| tcp_delete_keepalive_timer(sk); |
| } |
| |
| static inline void tcp_synq_added(struct sock *sk) |
| { |
| if (reqsk_queue_added(&tcp_sk(sk)->accept_queue) == 0) |
| tcp_reset_keepalive_timer(sk, TCP_TIMEOUT_INIT); |
| } |
| |
| static inline int tcp_synq_len(struct sock *sk) |
| { |
| return reqsk_queue_len(&tcp_sk(sk)->accept_queue); |
| } |
| |
| static inline int tcp_synq_young(struct sock *sk) |
| { |
| return reqsk_queue_len_young(&tcp_sk(sk)->accept_queue); |
| } |
| |
| static inline int tcp_synq_is_full(struct sock *sk) |
| { |
| return reqsk_queue_is_full(&tcp_sk(sk)->accept_queue); |
| } |
| |
| static inline void tcp_synq_unlink(struct tcp_sock *tp, struct request_sock *req, |
| struct request_sock **prev) |
| { |
| reqsk_queue_unlink(&tp->accept_queue, req, prev); |
| } |
| |
| static inline void tcp_synq_drop(struct sock *sk, struct request_sock *req, |
| struct request_sock **prev) |
| { |
| tcp_synq_unlink(tcp_sk(sk), req, prev); |
| tcp_synq_removed(sk, req); |
| reqsk_free(req); |
| } |
| |
| static __inline__ void tcp_openreq_init(struct request_sock *req, |
| struct tcp_options_received *rx_opt, |
| struct sk_buff *skb) |
| { |
| struct inet_request_sock *ireq = inet_rsk(req); |
| |
| req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */ |
| tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq; |
| req->mss = rx_opt->mss_clamp; |
| req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0; |
| ireq->tstamp_ok = rx_opt->tstamp_ok; |
| ireq->sack_ok = rx_opt->sack_ok; |
| ireq->snd_wscale = rx_opt->snd_wscale; |
| ireq->wscale_ok = rx_opt->wscale_ok; |
| ireq->acked = 0; |
| ireq->ecn_ok = 0; |
| ireq->rmt_port = skb->h.th->source; |
| } |
| |
| extern void tcp_enter_memory_pressure(void); |
| |
| extern void tcp_listen_wlock(void); |
| |
| /* - We may sleep inside this lock. |
| * - If sleeping is not required (or called from BH), |
| * use plain read_(un)lock(&tcp_lhash_lock). |
| */ |
| |
| static inline void tcp_listen_lock(void) |
| { |
| /* read_lock synchronizes to candidates to writers */ |
| read_lock(&tcp_lhash_lock); |
| atomic_inc(&tcp_lhash_users); |
| read_unlock(&tcp_lhash_lock); |
| } |
| |
| static inline void tcp_listen_unlock(void) |
| { |
| if (atomic_dec_and_test(&tcp_lhash_users)) |
| wake_up(&tcp_lhash_wait); |
| } |
| |
| static inline int keepalive_intvl_when(const struct tcp_sock *tp) |
| { |
| return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl; |
| } |
| |
| static inline int keepalive_time_when(const struct tcp_sock *tp) |
| { |
| return tp->keepalive_time ? : sysctl_tcp_keepalive_time; |
| } |
| |
| static inline int tcp_fin_time(const struct tcp_sock *tp) |
| { |
| int fin_timeout = tp->linger2 ? : sysctl_tcp_fin_timeout; |
| |
| if (fin_timeout < (tp->rto<<2) - (tp->rto>>1)) |
| fin_timeout = (tp->rto<<2) - (tp->rto>>1); |
| |
| return fin_timeout; |
| } |
| |
| static inline int tcp_paws_check(const struct tcp_options_received *rx_opt, int rst) |
| { |
| if ((s32)(rx_opt->rcv_tsval - rx_opt->ts_recent) >= 0) |
| return 0; |
| if (xtime.tv_sec >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS) |
| return 0; |
| |
| /* RST segments are not recommended to carry timestamp, |
| and, if they do, it is recommended to ignore PAWS because |
| "their cleanup function should take precedence over timestamps." |
| Certainly, it is mistake. It is necessary to understand the reasons |
| of this constraint to relax it: if peer reboots, clock may go |
| out-of-sync and half-open connections will not be reset. |
| Actually, the problem would be not existing if all |
| the implementations followed draft about maintaining clock |
| via reboots. Linux-2.2 DOES NOT! |
| |
| However, we can relax time bounds for RST segments to MSL. |
| */ |
| if (rst && xtime.tv_sec >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL) |
| return 0; |
| return 1; |
| } |
| |
| static inline void tcp_v4_setup_caps(struct sock *sk, struct dst_entry *dst) |
| { |
| sk->sk_route_caps = dst->dev->features; |
| if (sk->sk_route_caps & NETIF_F_TSO) { |
| if (sock_flag(sk, SOCK_NO_LARGESEND) || dst->header_len) |
| sk->sk_route_caps &= ~NETIF_F_TSO; |
| } |
| } |
| |
| #define TCP_CHECK_TIMER(sk) do { } while (0) |
| |
| static inline int tcp_use_frto(const struct sock *sk) |
| { |
| const struct tcp_sock *tp = tcp_sk(sk); |
| |
| /* F-RTO must be activated in sysctl and there must be some |
| * unsent new data, and the advertised window should allow |
| * sending it. |
| */ |
| return (sysctl_tcp_frto && sk->sk_send_head && |
| !after(TCP_SKB_CB(sk->sk_send_head)->end_seq, |
| tp->snd_una + tp->snd_wnd)); |
| } |
| |
| static inline void tcp_mib_init(void) |
| { |
| /* See RFC 2012 */ |
| TCP_ADD_STATS_USER(TCP_MIB_RTOALGORITHM, 1); |
| TCP_ADD_STATS_USER(TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); |
| TCP_ADD_STATS_USER(TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); |
| TCP_ADD_STATS_USER(TCP_MIB_MAXCONN, -1); |
| } |
| |
| /* /proc */ |
| enum tcp_seq_states { |
| TCP_SEQ_STATE_LISTENING, |
| TCP_SEQ_STATE_OPENREQ, |
| TCP_SEQ_STATE_ESTABLISHED, |
| TCP_SEQ_STATE_TIME_WAIT, |
| }; |
| |
| struct tcp_seq_afinfo { |
| struct module *owner; |
| char *name; |
| sa_family_t family; |
| int (*seq_show) (struct seq_file *m, void *v); |
| struct file_operations *seq_fops; |
| }; |
| |
| struct tcp_iter_state { |
| sa_family_t family; |
| enum tcp_seq_states state; |
| struct sock *syn_wait_sk; |
| int bucket, sbucket, num, uid; |
| struct seq_operations seq_ops; |
| }; |
| |
| extern int tcp_proc_register(struct tcp_seq_afinfo *afinfo); |
| extern void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo); |
| |
| #endif /* _TCP_H */ |