/* * 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 FASTRETRANS_DEBUG 1 #include <linux/list.h>#include <linux/tcp.h>#include <linux/bug.h>#include <linux/slab.h>#include <linux/cache.h>#include <linux/percpu.h>#include <linux/skbuff.h>#include <linux/dmaengine.h>#include <linux/crypto.h>#include <linux/cryptohash.h>#include <linux/kref.h> #include <net/inet_connection_sock.h>#include <net/inet_timewait_sock.h>#include <net/inet_hashtables.h>#include <net/checksum.h>#include <net/request_sock.h>#include <net/sock.h>#include <net/snmp.h>#include <net/ip.h>#include <net/tcp_states.h>#include <net/inet_ecn.h>#include <net/dst.h> #include <linux/seq_file.h>#include <linux/memcontrol.h> extern struct inet_hashinfo tcp_hashinfo; extern struct percpu_counter tcp_orphan_count;extern void tcp_time_wait(struct sock *sk, int state, int timeo); #define MAX_TCP_HEADER (128 + MAX_HEADER)#define MAX_TCP_OPTION_SPACE 40 /* * Never offer a window over 32767 without using window scaling. Some * poor stacks do signed 16bit maths! */#define MAX_TCP_WINDOW 32767U /* Offer an initial receive window of 10 mss. */#define TCP_DEFAULT_INIT_RCVWND 10 /* Minimal accepted MSS. It is (60+60+8) - (20+20). */#define TCP_MIN_MSS 88U /* The least MTU to use for probing */#define TCP_BASE_MSS 512 /* 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 minimum */ #define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a * connection: ~180sec is RFC minimum */ #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)(1*HZ)) /* RFC6298 2.1 initial RTO value */#define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now * used as a fallback RTO for the * initial data transmission if no * valid RTT sample has been acquired, * most likely due to retrans in 3WHS. */ #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_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. *//* * 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 */#define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */#define TCPOPT_COOKIE 253 /* Cookie extension (experimental) */ /* * TCP option lengths */ #define TCPOLEN_MSS 4#define TCPOLEN_WINDOW 3#define TCPOLEN_SACK_PERM 2#define TCPOLEN_TIMESTAMP 10#define TCPOLEN_MD5SIG 18#define TCPOLEN_COOKIE_BASE 2 /* Cookie-less header extension */#define TCPOLEN_COOKIE_PAIR 3 /* Cookie pair header extension */#define TCPOLEN_COOKIE_MIN (TCPOLEN_COOKIE_BASE+TCP_COOKIE_MIN)#define TCPOLEN_COOKIE_MAX (TCPOLEN_COOKIE_BASE+TCP_COOKIE_MAX) /* 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 TCPOLEN_MD5SIG_ALIGNED 20#define TCPOLEN_MSS_ALIGNED 4 /* 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 overridden for already queued data */ /* TCP thin-stream limits */#define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */ /* TCP initial congestion window as per draft-hkchu-tcpm-initcwnd-01 */#define TCP_INIT_CWND 10 extern struct inet_timewait_death_row tcp_death_row; /* 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_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_fack;extern int sysctl_tcp_reordering;extern int sysctl_tcp_ecn;extern int sysctl_tcp_dsack;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_frto_response;extern int sysctl_tcp_low_latency;extern int sysctl_tcp_dma_copybreak;extern int sysctl_tcp_nometrics_save;extern int sysctl_tcp_moderate_rcvbuf;extern int sysctl_tcp_tso_win_divisor;extern int sysctl_tcp_abc;extern int sysctl_tcp_mtu_probing;extern int sysctl_tcp_base_mss;extern int sysctl_tcp_workaround_signed_windows;extern int sysctl_tcp_slow_start_after_idle;extern int sysctl_tcp_max_ssthresh;extern int sysctl_tcp_cookie_size;extern int sysctl_tcp_thin_linear_timeouts;extern int sysctl_tcp_thin_dupack;extern int sysctl_tcp_early_retrans; extern atomic_long_t tcp_memory_allocated;extern struct percpu_counter tcp_sockets_allocated;extern int tcp_memory_pressure; /* * The next routines deal with comparing 32 bit unsigned ints * and worry about wraparound (automatic with unsigned arithmetic). */ static inline bool before(__u32 seq1, __u32 seq2){ return (__s32)(seq1-seq2) < 0;}#define after(seq2, seq1) before(seq1, seq2) /* is s2<=s1<=s3 ? */static inline bool between(__u32 seq1, __u32 seq2, __u32 seq3){ return seq3 - seq2 >= seq1 - seq2;} static inline bool tcp_out_of_memory(struct sock *sk){ if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && sk_memory_allocated(sk) > sk_prot_mem_limits(sk, 2)) return true; return false;} static inline bool tcp_too_many_orphans(struct sock *sk, int shift){ struct percpu_counter *ocp = sk->sk_prot->orphan_count; int orphans = percpu_counter_read_positive(ocp); if (orphans << shift > sysctl_tcp_max_orphans) { orphans = percpu_counter_sum_positive(ocp); if (orphans << shift > sysctl_tcp_max_orphans) return true; } return false;} extern bool tcp_check_oom(struct sock *sk, int shift); /* syncookies: remember time of last synqueue overflow */static inline void tcp_synq_overflow(struct sock *sk){ tcp_sk(sk)->rx_opt.ts_recent_stamp = jiffies;} /* syncookies: no recent synqueue overflow on this listening socket? */static inline bool tcp_synq_no_recent_overflow(const struct sock *sk){ unsigned long last_overflow = tcp_sk(sk)->rx_opt.ts_recent_stamp; return time_after(jiffies, last_overflow + TCP_TIMEOUT_FALLBACK);} extern struct proto tcp_prot; #define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field)#define TCP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.tcp_statistics, field)#define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field)#define TCP_ADD_STATS_USER(net, field, val) SNMP_ADD_STATS_USER((net)->mib.tcp_statistics, field, val)#define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val) extern void tcp_init_mem(struct net *net); 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 struct inet_peer *tcp_v4_get_peer(struct sock *sk, bool *release_it);extern void *tcp_v4_tw_get_peer(struct sock *sk);extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw);extern int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t size);extern int tcp_sendpage(struct sock *sk, 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, const struct tcphdr *th, unsigned int len);extern int tcp_rcv_established(struct sock *sk, struct sk_buff *skb, const struct tcphdr *th, unsigned int len);extern void tcp_rcv_space_adjust(struct sock *sk);extern void tcp_cleanup_rbuf(struct sock *sk, int copied);extern int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp);extern void tcp_twsk_destructor(struct sock *sk);extern ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags); static inline void tcp_dec_quickack_mode(struct sock *sk, const unsigned int pkts){ struct inet_connection_sock *icsk = inet_csk(sk); if (icsk->icsk_ack.quick) { if (pkts >= icsk->icsk_ack.quick) { icsk->icsk_ack.quick = 0; /* Leaving quickack mode we deflate ATO. */ icsk->icsk_ack.ato = TCP_ATO_MIN; } else icsk->icsk_ack.quick -= pkts; }} #define TCP_ECN_OK 1#define TCP_ECN_QUEUE_CWR 2#define TCP_ECN_DEMAND_CWR 4#define TCP_ECN_SEEN 8 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 inet_timewait_sock *tw, struct sk_buff *skb, const struct tcphdr *th);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 bool tcp_use_frto(struct sock *sk);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 void tcp_init_sock(struct sock *sk);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, unsigned int optlen);extern int compat_tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen);extern int compat_tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen);extern void tcp_set_keepalive(struct sock *sk, int val);extern void tcp_syn_ack_timeout(struct sock *sk, struct request_sock *req);extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t len, int nonblock, int flags, int *addr_len);extern void tcp_parse_options(const struct sk_buff *skb, struct tcp_options_received *opt_rx, const u8 **hvpp, int estab);extern const u8 *tcp_parse_md5sig_option(const struct tcphdr *th); /* * TCP v4 functions exported for the inet6 API */ extern void tcp_v4_send_check(struct sock *sk, 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, struct request_values *rvp);extern int tcp_disconnect(struct sock *sk, int flags); void tcp_connect_init(struct sock *sk);void tcp_finish_connect(struct sock *sk, struct sk_buff *skb);int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size); /* From syncookies.c */extern __u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS];extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb, struct ip_options *opt);#ifdef CONFIG_SYN_COOKIESextern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mss);#elsestatic inline __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mss){ return 0;}#endif extern __u32 cookie_init_timestamp(struct request_sock *req);extern bool cookie_check_timestamp(struct tcp_options_received *opt, bool *); /* From net/ipv6/syncookies.c */extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb);#ifdef CONFIG_SYN_COOKIESextern __u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb, __u16 *mss);#elsestatic inline __u32 cookie_v6_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mss){ return 0;}#endif/* tcp_output.c */ extern void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, int nonagle);extern bool tcp_may_send_now(struct sock *sk);extern int tcp_retransmit_skb(struct sock *, struct sk_buff *);extern void tcp_retransmit_timer(struct sock *sk);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 int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int); 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, gfp_t priority);extern int tcp_send_synack(struct sock *);extern bool tcp_syn_flood_action(struct sock *sk, const struct sk_buff *skb, const char *proto);extern void tcp_push_one(struct sock *, unsigned int mss_now);extern void tcp_send_ack(struct sock *sk);extern void tcp_send_delayed_ack(struct sock *sk); /* tcp_input.c */extern void tcp_cwnd_application_limited(struct sock *sk);extern void tcp_resume_early_retransmit(struct sock *sk);extern void tcp_rearm_rto(struct sock *sk); /* tcp_timer.c */extern void tcp_init_xmit_timers(struct sock *);Lines 1–500 of 1613. 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/* * 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 FASTRETRANS_DEBUG 1 #include <linux/list.h> #include <linux/tcp.h> #include <linux/bug.h> #include <linux/slab.h> #include <linux/cache.h> #include <linux/percpu.h> #include <linux/skbuff.h> #include <linux/dmaengine.h> #include <linux/crypto.h> #include <linux/cryptohash.h> #include <linux/kref.h> #include <net/inet_connection_sock.h> #include <net/inet_timewait_sock.h> #include <net/inet_hashtables.h> #include <net/checksum.h> #include <net/request_sock.h> #include <net/sock.h> #include <net/snmp.h> #include <net/ip.h> #include <net/tcp_states.h> #include <net/inet_ecn.h> #include <net/dst.h> #include <linux/seq_file.h> #include <linux/memcontrol.h> extern struct inet_hashinfo tcp_hashinfo; extern struct percpu_counter tcp_orphan_count; extern void tcp_time_wait(struct sock *sk, int state, int timeo); #define MAX_TCP_HEADER (128 + MAX_HEADER) #define MAX_TCP_OPTION_SPACE 40 /* * Never offer a window over 32767 without using window scaling. Some * poor stacks do signed 16bit maths! */ #define MAX_TCP_WINDOW 32767U /* Offer an initial receive window of 10 mss. */ #define TCP_DEFAULT_INIT_RCVWND 10 /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ #define TCP_MIN_MSS 88U /* The least MTU to use for probing */ #define TCP_BASE_MSS 512 /* 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 minimum */ #define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a * connection: ~180sec is RFC minimum */ #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)(1*HZ)) /* RFC6298 2.1 initial RTO value */ #define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now * used as a fallback RTO for the * initial data transmission if no * valid RTT sample has been acquired, * most likely due to retrans in 3WHS. */ #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_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. */ /* * 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 */ #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ #define TCPOPT_COOKIE 253 /* Cookie extension (experimental) */ /* * TCP option lengths */ #define TCPOLEN_MSS 4 #define TCPOLEN_WINDOW 3 #define TCPOLEN_SACK_PERM 2 #define TCPOLEN_TIMESTAMP 10 #define TCPOLEN_MD5SIG 18 #define TCPOLEN_COOKIE_BASE 2 /* Cookie-less header extension */ #define TCPOLEN_COOKIE_PAIR 3 /* Cookie pair header extension */ #define TCPOLEN_COOKIE_MIN (TCPOLEN_COOKIE_BASE+TCP_COOKIE_MIN) #define TCPOLEN_COOKIE_MAX (TCPOLEN_COOKIE_BASE+TCP_COOKIE_MAX) /* 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 TCPOLEN_MD5SIG_ALIGNED 20 #define TCPOLEN_MSS_ALIGNED 4 /* 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 overridden for already queued data */ /* TCP thin-stream limits */ #define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */ /* TCP initial congestion window as per draft-hkchu-tcpm-initcwnd-01 */ #define TCP_INIT_CWND 10 extern struct inet_timewait_death_row tcp_death_row; /* 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_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_fack; extern int sysctl_tcp_reordering; extern int sysctl_tcp_ecn; extern int sysctl_tcp_dsack; 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_frto_response; extern int sysctl_tcp_low_latency; extern int sysctl_tcp_dma_copybreak; extern int sysctl_tcp_nometrics_save; extern int sysctl_tcp_moderate_rcvbuf; extern int sysctl_tcp_tso_win_divisor; extern int sysctl_tcp_abc; extern int sysctl_tcp_mtu_probing; extern int sysctl_tcp_base_mss; extern int sysctl_tcp_workaround_signed_windows; extern int sysctl_tcp_slow_start_after_idle; extern int sysctl_tcp_max_ssthresh; extern int sysctl_tcp_cookie_size; extern int sysctl_tcp_thin_linear_timeouts; extern int sysctl_tcp_thin_dupack; extern int sysctl_tcp_early_retrans; extern atomic_long_t tcp_memory_allocated; extern struct percpu_counter tcp_sockets_allocated; extern int tcp_memory_pressure; /* * The next routines deal with comparing 32 bit unsigned ints * and worry about wraparound (automatic with unsigned arithmetic). */ static inline bool before(__u32 seq1, __u32 seq2) { return (__s32)(seq1-seq2) < 0; } #define after(seq2, seq1) before(seq1, seq2) /* is s2<=s1<=s3 ? */ static inline bool between(__u32 seq1, __u32 seq2, __u32 seq3) { return seq3 - seq2 >= seq1 - seq2; } static inline bool tcp_out_of_memory(struct sock *sk) { if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && sk_memory_allocated(sk) > sk_prot_mem_limits(sk, 2)) return true; return false; } static inline bool tcp_too_many_orphans(struct sock *sk, int shift) { struct percpu_counter *ocp = sk->sk_prot->orphan_count; int orphans = percpu_counter_read_positive(ocp); if (orphans << shift > sysctl_tcp_max_orphans) { orphans = percpu_counter_sum_positive(ocp); if (orphans << shift > sysctl_tcp_max_orphans) return true; } return false; } extern bool tcp_check_oom(struct sock *sk, int shift); /* syncookies: remember time of last synqueue overflow */ static inline void tcp_synq_overflow(struct sock *sk) { tcp_sk(sk)->rx_opt.ts_recent_stamp = jiffies; } /* syncookies: no recent synqueue overflow on this listening socket? */ static inline bool tcp_synq_no_recent_overflow(const struct sock *sk) { unsigned long last_overflow = tcp_sk(sk)->rx_opt.ts_recent_stamp; return time_after(jiffies, last_overflow + TCP_TIMEOUT_FALLBACK); } extern struct proto tcp_prot; #define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field) #define TCP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.tcp_statistics, field) #define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field) #define TCP_ADD_STATS_USER(net, field, val) SNMP_ADD_STATS_USER((net)->mib.tcp_statistics, field, val) #define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val) extern void tcp_init_mem(struct net *net); 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 struct inet_peer *tcp_v4_get_peer(struct sock *sk, bool *release_it); extern void *tcp_v4_tw_get_peer(struct sock *sk); extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw); extern int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t size); extern int tcp_sendpage(struct sock *sk, 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, const struct tcphdr *th, unsigned int len); extern int tcp_rcv_established(struct sock *sk, struct sk_buff *skb, const struct tcphdr *th, unsigned int len); extern void tcp_rcv_space_adjust(struct sock *sk); extern void tcp_cleanup_rbuf(struct sock *sk, int copied); extern int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); extern void tcp_twsk_destructor(struct sock *sk); extern ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags); static inline void tcp_dec_quickack_mode(struct sock *sk, const unsigned int pkts) { struct inet_connection_sock *icsk = inet_csk(sk); if (icsk->icsk_ack.quick) { if (pkts >= icsk->icsk_ack.quick) { icsk->icsk_ack.quick = 0; /* Leaving quickack mode we deflate ATO. */ icsk->icsk_ack.ato = TCP_ATO_MIN; } else icsk->icsk_ack.quick -= pkts; } } #define TCP_ECN_OK 1 #define TCP_ECN_QUEUE_CWR 2 #define TCP_ECN_DEMAND_CWR 4 #define TCP_ECN_SEEN 8 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 inet_timewait_sock *tw, struct sk_buff *skb, const struct tcphdr *th); 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 bool tcp_use_frto(struct sock *sk); 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 void tcp_init_sock(struct sock *sk); 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, unsigned int optlen); extern int compat_tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval, int __user *optlen); extern int compat_tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval, unsigned int optlen); extern void tcp_set_keepalive(struct sock *sk, int val); extern void tcp_syn_ack_timeout(struct sock *sk, struct request_sock *req); extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t len, int nonblock, int flags, int *addr_len); extern void tcp_parse_options(const struct sk_buff *skb, struct tcp_options_received *opt_rx, const u8 **hvpp, int estab); extern const u8 *tcp_parse_md5sig_option(const struct tcphdr *th); /* * TCP v4 functions exported for the inet6 API */ extern void tcp_v4_send_check(struct sock *sk, 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, struct request_values *rvp); extern int tcp_disconnect(struct sock *sk, int flags); void tcp_connect_init(struct sock *sk); void tcp_finish_connect(struct sock *sk, struct sk_buff *skb); int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size); /* From syncookies.c */ extern __u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS]; extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb, struct ip_options *opt); #ifdef CONFIG_SYN_COOKIES extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mss); #else static inline __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mss) { return 0; } #endif extern __u32 cookie_init_timestamp(struct request_sock *req); extern bool cookie_check_timestamp(struct tcp_options_received *opt, bool *); /* From net/ipv6/syncookies.c */ extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); #ifdef CONFIG_SYN_COOKIES extern __u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb, __u16 *mss); #else static inline __u32 cookie_v6_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mss) { return 0; } #endif /* tcp_output.c */ extern void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, int nonagle); extern bool tcp_may_send_now(struct sock *sk); extern int tcp_retransmit_skb(struct sock *, struct sk_buff *); extern void tcp_retransmit_timer(struct sock *sk); 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 int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int); 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, gfp_t priority); extern int tcp_send_synack(struct sock *); extern bool tcp_syn_flood_action(struct sock *sk, const struct sk_buff *skb, const char *proto); extern void tcp_push_one(struct sock *, unsigned int mss_now); extern void tcp_send_ack(struct sock *sk); extern void tcp_send_delayed_ack(struct sock *sk); /* tcp_input.c */ extern void tcp_cwnd_application_limited(struct sock *sk); extern void tcp_resume_early_retransmit(struct sock *sk); extern void tcp_rearm_rto(struct sock *sk); /* tcp_timer.c */ extern void tcp_init_xmit_timers(struct sock *);