diff options
Diffstat (limited to 'ANDROID_3.4.5/include/net/tcp.h')
| -rw-r--r-- | ANDROID_3.4.5/include/net/tcp.h | 1581 |
1 files changed, 0 insertions, 1581 deletions
diff --git a/ANDROID_3.4.5/include/net/tcp.h b/ANDROID_3.4.5/include/net/tcp.h deleted file mode 100644 index 50660b3e..00000000 --- a/ANDROID_3.4.5/include/net/tcp.h +++ /dev/null @@ -1,1581 +0,0 @@ -/* - * 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)) /* RFC2988bis 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 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 int before(__u32 seq1, __u32 seq2) -{ - return (__s32)(seq1-seq2) < 0; -} -#define after(seq2, seq1) before(seq1, seq2) - -/* is s2<=s1<=s3 ? */ -static inline int 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 int 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 - -static __inline__ void -TCP_ECN_create_request(struct request_sock *req, struct tcphdr *th) -{ - if (sysctl_tcp_ecn && th->ece && th->cwr) - inet_rsk(req)->ecn_ok = 1; -} - -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 int 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 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); - - -/* 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 int 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 int 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); - -/* tcp_timer.c */ -extern void tcp_init_xmit_timers(struct sock *); -static inline void tcp_clear_xmit_timers(struct sock *sk) -{ - inet_csk_clear_xmit_timers(sk); -} - -extern unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); -extern unsigned int tcp_current_mss(struct sock *sk); - -/* Bound MSS / TSO packet size with the half of the window */ -static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) -{ - int cutoff; - - /* When peer uses tiny windows, there is no use in packetizing - * to sub-MSS pieces for the sake of SWS or making sure there - * are enough packets in the pipe for fast recovery. - * - * On the other hand, for extremely large MSS devices, handling - * smaller than MSS windows in this way does make sense. - */ - if (tp->max_window >= 512) - cutoff = (tp->max_window >> 1); - else - cutoff = tp->max_window; - - if (cutoff && pktsize > cutoff) - return max_t(int, cutoff, 68U - tp->tcp_header_len); - else - return pktsize; -} - -/* tcp.c */ -extern void tcp_get_info(const 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); - -extern void tcp_initialize_rcv_mss(struct sock *sk); - -extern int tcp_mtu_to_mss(const struct sock *sk, int pmtu); -extern int tcp_mss_to_mtu(const struct sock *sk, int mss); -extern void tcp_mtup_init(struct sock *sk); -extern void tcp_valid_rtt_meas(struct sock *sk, u32 seq_rtt); - -static inline void tcp_bound_rto(const struct sock *sk) -{ - if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX) - inet_csk(sk)->icsk_rto = TCP_RTO_MAX; -} - -static inline u32 __tcp_set_rto(const struct tcp_sock *tp) -{ - return (tp->srtt >> 3) + tp->rttvar; -} - -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 = tcp_sk(sk); - - if (skb_queue_empty(&tp->out_of_order_queue) && - tp->rcv_wnd && - atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf && - !tp->urg_data) - tcp_fast_path_on(tp); -} - -/* Compute the actual rto_min value */ -static inline u32 tcp_rto_min(struct sock *sk) -{ - const struct dst_entry *dst = __sk_dst_get(sk); - u32 rto_min = TCP_RTO_MIN; - - if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) - rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); - return rto_min; -} - -/* 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 decided - * to use only the low 32-bits of jiffies and hide the ugly - * casts with the following macro. - */ -#define tcp_time_stamp ((__u32)(jiffies)) - -#define tcp_flag_byte(th) (((u_int8_t *)th)[13]) - -#define TCPHDR_FIN 0x01 -#define TCPHDR_SYN 0x02 -#define TCPHDR_RST 0x04 -#define TCPHDR_PSH 0x08 -#define TCPHDR_ACK 0x10 -#define TCPHDR_URG 0x20 -#define TCPHDR_ECE 0x40 -#define TCPHDR_CWR 0x80 - -/* This is what the send packet queuing 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 44 bytes if IPV6 is enabled. - * If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately. - */ -struct tcp_skb_cb { - union { - struct inet_skb_parm h4; -#if IS_ENABLED(CONFIG_IPV6) - 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 tcp_flags; /* TCP header flags. (tcp[13]) */ - __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 */ - __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ - /* 1 byte hole */ -#define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */ -#define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS) - - __u32 ack_seq; /* Sequence number ACK'd */ -}; - -#define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) - -/* 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)->gso_segs; -} - -/* This is valid iff tcp_skb_pcount() > 1. */ -static inline int tcp_skb_mss(const struct sk_buff *skb) -{ - return skb_shinfo(skb)->gso_size; -} - -/* 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 -#define TCP_CA_MAX 128 -#define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) - -#define TCP_CONG_NON_RESTRICTED 0x1 -#define TCP_CONG_RTT_STAMP 0x2 - -struct tcp_congestion_ops { - struct list_head list; - unsigned long flags; - - /* initialize private data (optional) */ - void (*init)(struct sock *sk); - /* cleanup private data (optional) */ - void (*release)(struct sock *sk); - - /* return slow start threshold (required) */ - u32 (*ssthresh)(struct sock *sk); - /* lower bound for congestion window (optional) */ - u32 (*min_cwnd)(const struct sock *sk); - /* do new cwnd calculation (required) */ - void (*cong_avoid)(struct sock *sk, u32 ack, u32 in_flight); - /* call before changing ca_state (optional) */ - void (*set_state)(struct sock *sk, u8 new_state); - /* call when cwnd event occurs (optional) */ - void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev); - /* new value of cwnd after loss (optional) */ - u32 (*undo_cwnd)(struct sock *sk); - /* hook for packet ack accounting (optional) */ - void (*pkts_acked)(struct sock *sk, u32 num_acked, s32 rtt_us); - /* get info for inet_diag (optional) */ - void (*get_info)(struct sock *sk, 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 sock *sk); -extern void tcp_cleanup_congestion_control(struct sock *sk); -extern int tcp_set_default_congestion_control(const char *name); -extern void tcp_get_default_congestion_control(char *name); -extern void tcp_get_available_congestion_control(char *buf, size_t len); -extern void tcp_get_allowed_congestion_control(char *buf, size_t len); -extern int tcp_set_allowed_congestion_control(char *allowed); -extern int tcp_set_congestion_control(struct sock *sk, const char *name); -extern void tcp_slow_start(struct tcp_sock *tp); -extern void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w); - -extern struct tcp_congestion_ops tcp_init_congestion_ops; -extern u32 tcp_reno_ssthresh(struct sock *sk); -extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight); -extern u32 tcp_reno_min_cwnd(const struct sock *sk); -extern struct tcp_congestion_ops tcp_reno; - -static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state) -{ - struct inet_connection_sock *icsk = inet_csk(sk); - - if (icsk->icsk_ca_ops->set_state) - icsk->icsk_ca_ops->set_state(sk, ca_state); - icsk->icsk_ca_state = ca_state; -} - -static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) -{ - const struct inet_connection_sock *icsk = inet_csk(sk); - - if (icsk->icsk_ca_ops->cwnd_event) - icsk->icsk_ca_ops->cwnd_event(sk, event); -} - -/* These functions determine how the current flow behaves in respect of SACK - * handling. SACK is negotiated with the peer, and therefore it can vary - * between different flows. - * - * tcp_is_sack - SACK enabled - * tcp_is_reno - No SACK - * tcp_is_fack - FACK enabled, implies SACK enabled - */ -static inline int tcp_is_sack(const struct tcp_sock *tp) -{ - return tp->rx_opt.sack_ok; -} - -static inline int tcp_is_reno(const struct tcp_sock *tp) -{ - return !tcp_is_sack(tp); -} - -static inline int tcp_is_fack(const struct tcp_sock *tp) -{ - return tp->rx_opt.sack_ok & TCP_FACK_ENABLED; -} - -static inline void tcp_enable_fack(struct tcp_sock *tp) -{ - tp->rx_opt.sack_ok |= TCP_FACK_ENABLED; -} - -static inline unsigned int tcp_left_out(const struct tcp_sock *tp) -{ - return tp->sacked_out + tp->lost_out; -} - -/* 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 - tcp_left_out(tp) + tp->retrans_out; -} - -#define TCP_INFINITE_SSTHRESH 0x7fffffff - -static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) -{ - return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; -} - -/* 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(const struct sock *sk) -{ - const struct tcp_sock *tp = tcp_sk(sk); - - if ((1 << inet_csk(sk)->icsk_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))); -} - -/* Use define here intentionally to get WARN_ON location shown at the caller */ -#define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out) - -extern void tcp_enter_cwr(struct sock *sk, const int set_ssthresh); -extern __u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst); - -/* The maximum number of MSS of available cwnd for which TSO defers - * sending if not using sysctl_tcp_tso_win_divisor. - */ -static inline __u32 tcp_max_tso_deferred_mss(const struct tcp_sock *tp) -{ - return 3; -} - -/* Slow start with delack produces 3 packets of burst, so that - * it is safe "de facto". This will be the default - same as - * the default reordering threshold - but if reordering increases, - * we must be able to allow cwnd to burst at least this much in order - * to not pull it back when holes are filled. - */ -static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp) -{ - return tp->reordering; -} - -/* Returns end sequence number of the receiver's advertised window */ -static inline u32 tcp_wnd_end(const struct tcp_sock *tp) -{ - return tp->snd_una + tp->snd_wnd; -} -extern int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight); - -static inline void tcp_minshall_update(struct tcp_sock *tp, unsigned int mss, - const struct sk_buff *skb) -{ - if (skb->len < mss) - tp->snd_sml = TCP_SKB_CB(skb)->end_seq; -} - -static inline void tcp_check_probe_timer(struct sock *sk) -{ - const struct tcp_sock *tp = tcp_sk(sk); - const struct inet_connection_sock *icsk = inet_csk(sk); - - if (!tp->packets_out && !icsk->icsk_pending) - inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0, - icsk->icsk_rto, TCP_RTO_MAX); -} - -static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) -{ - tp->snd_wl1 = seq; -} - -static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq) -{ - tp->snd_wl1 = seq; -} - -/* - * Calculate(/check) TCP checksum - */ -static inline __sum16 tcp_v4_check(int len, __be32 saddr, - __be32 daddr, __wsum base) -{ - return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base); -} - -static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb) -{ - return __skb_checksum_complete(skb); -} - -static inline int tcp_checksum_complete(struct sk_buff *skb) -{ - return !skb_csum_unnecessary(skb) && - __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); -#ifdef CONFIG_NET_DMA - tp->ucopy.dma_chan = NULL; - tp->ucopy.wakeup = 0; - tp->ucopy.pinned_list = NULL; - tp->ucopy.dma_cookie = 0; -#endif -} - -/* 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) - return 0; - - __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_backlog_rcv(sk, skb1); - NET_INC_STATS_BH(sock_net(sk), - LINUX_MIB_TCPPREQUEUEDROPPED); - } - - tp->ucopy.memory = 0; - } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) { - wake_up_interruptible_sync_poll(sk_sleep(sk), - POLLIN | POLLRDNORM | POLLRDBAND); - if (!inet_csk_ack_scheduled(sk)) - inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, - (3 * tcp_rto_min(sk)) / 4, - TCP_RTO_MAX); - } - return 1; -} - - -#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 -extern void tcp_set_state(struct sock *sk, int state); - -extern void tcp_done(struct sock *sk); - -static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) -{ - rx_opt->dsack = 0; - rx_opt->num_sacks = 0; -} - -/* 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, - __u32 init_rcv_wnd); - -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_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! */ - req->cookie_ts = 0; - 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 = tcp_hdr(skb)->source; - ireq->loc_port = tcp_hdr(skb)->dest; -} - -extern void tcp_enter_memory_pressure(struct sock *sk); - -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 keepalive_probes(const struct tcp_sock *tp) -{ - return tp->keepalive_probes ? : sysctl_tcp_keepalive_probes; -} - -static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) -{ - const struct inet_connection_sock *icsk = &tp->inet_conn; - - return min_t(u32, tcp_time_stamp - icsk->icsk_ack.lrcvtime, - tcp_time_stamp - tp->rcv_tstamp); -} - -static inline int tcp_fin_time(const struct sock *sk) -{ - int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout; - const int rto = inet_csk(sk)->icsk_rto; - - if (fin_timeout < (rto << 2) - (rto >> 1)) - fin_timeout = (rto << 2) - (rto >> 1); - - return fin_timeout; -} - -static inline int tcp_paws_check(const struct tcp_options_received *rx_opt, - int paws_win) -{ - if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) - return 1; - if (unlikely(get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)) - return 1; - /* - * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0, - * then following tcp messages have valid values. Ignore 0 value, - * or else 'negative' tsval might forbid us to accept their packets. - */ - if (!rx_opt->ts_recent) - return 1; - return 0; -} - -static inline int tcp_paws_reject(const struct tcp_options_received *rx_opt, - int rst) -{ - if (tcp_paws_check(rx_opt, 0)) - 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 && get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL) - return 0; - return 1; -} - -static inline void tcp_mib_init(struct net *net) -{ - /* See RFC 2012 */ - TCP_ADD_STATS_USER(net, TCP_MIB_RTOALGORITHM, 1); - TCP_ADD_STATS_USER(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); - TCP_ADD_STATS_USER(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); - TCP_ADD_STATS_USER(net, TCP_MIB_MAXCONN, -1); -} - -/* from STCP */ -static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp) -{ - tp->lost_skb_hint = NULL; - tp->scoreboard_skb_hint = NULL; -} - -static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) -{ - tcp_clear_retrans_hints_partial(tp); - tp->retransmit_skb_hint = NULL; -} - -/* MD5 Signature */ -struct crypto_hash; - -union tcp_md5_addr { - struct in_addr a4; -#if IS_ENABLED(CONFIG_IPV6) - struct in6_addr a6; -#endif -}; - -/* - key database */ -struct tcp_md5sig_key { - struct hlist_node node; - u8 keylen; - u8 family; /* AF_INET or AF_INET6 */ - union tcp_md5_addr addr; - u8 key[TCP_MD5SIG_MAXKEYLEN]; - struct rcu_head rcu; -}; - -/* - sock block */ -struct tcp_md5sig_info { - struct hlist_head head; - struct rcu_head rcu; -}; - -/* - pseudo header */ -struct tcp4_pseudohdr { - __be32 saddr; - __be32 daddr; - __u8 pad; - __u8 protocol; - __be16 len; -}; - -struct tcp6_pseudohdr { - struct in6_addr saddr; - struct in6_addr daddr; - __be32 len; - __be32 protocol; /* including padding */ -}; - -union tcp_md5sum_block { - struct tcp4_pseudohdr ip4; -#if IS_ENABLED(CONFIG_IPV6) - struct tcp6_pseudohdr ip6; -#endif -}; - -/* - pool: digest algorithm, hash description and scratch buffer */ -struct tcp_md5sig_pool { - struct hash_desc md5_desc; - union tcp_md5sum_block md5_blk; -}; - -/* - functions */ -extern int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key, - const struct sock *sk, - const struct request_sock *req, - const struct sk_buff *skb); -extern int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, - int family, const u8 *newkey, - u8 newkeylen, gfp_t gfp); -extern int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, - int family); -extern struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk, - struct sock *addr_sk); - -#ifdef CONFIG_TCP_MD5SIG -extern struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk, - const union tcp_md5_addr *addr, int family); -#define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) -#else -static inline struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk, - const union tcp_md5_addr *addr, - int family) -{ - return NULL; -} -#define tcp_twsk_md5_key(twsk) NULL -#endif - -extern struct tcp_md5sig_pool __percpu *tcp_alloc_md5sig_pool(struct sock *); -extern void tcp_free_md5sig_pool(void); - -extern struct tcp_md5sig_pool *tcp_get_md5sig_pool(void); -extern void tcp_put_md5sig_pool(void); - -extern int tcp_md5_hash_header(struct tcp_md5sig_pool *, const struct tcphdr *); -extern int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, const struct sk_buff *, - unsigned header_len); -extern int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, - const struct tcp_md5sig_key *key); - -/* write queue abstraction */ -static inline void tcp_write_queue_purge(struct sock *sk) -{ - struct sk_buff *skb; - - while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) - sk_wmem_free_skb(sk, skb); - sk_mem_reclaim(sk); - tcp_clear_all_retrans_hints(tcp_sk(sk)); -} - -static inline struct sk_buff *tcp_write_queue_head(const struct sock *sk) -{ - return skb_peek(&sk->sk_write_queue); -} - -static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk) -{ - return skb_peek_tail(&sk->sk_write_queue); -} - -static inline struct sk_buff *tcp_write_queue_next(const struct sock *sk, - const struct sk_buff *skb) -{ - return skb_queue_next(&sk->sk_write_queue, skb); -} - -static inline struct sk_buff *tcp_write_queue_prev(const struct sock *sk, - const struct sk_buff *skb) -{ - return skb_queue_prev(&sk->sk_write_queue, skb); -} - -#define tcp_for_write_queue(skb, sk) \ - skb_queue_walk(&(sk)->sk_write_queue, skb) - -#define tcp_for_write_queue_from(skb, sk) \ - skb_queue_walk_from(&(sk)->sk_write_queue, skb) - -#define tcp_for_write_queue_from_safe(skb, tmp, sk) \ - skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) - -static inline struct sk_buff *tcp_send_head(const struct sock *sk) -{ - return sk->sk_send_head; -} - -static inline bool tcp_skb_is_last(const struct sock *sk, - const struct sk_buff *skb) -{ - return skb_queue_is_last(&sk->sk_write_queue, skb); -} - -static inline void tcp_advance_send_head(struct sock *sk, const struct sk_buff *skb) -{ - if (tcp_skb_is_last(sk, skb)) - sk->sk_send_head = NULL; - else - sk->sk_send_head = tcp_write_queue_next(sk, skb); -} - -static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked) -{ - if (sk->sk_send_head == skb_unlinked) - sk->sk_send_head = NULL; -} - -static inline void tcp_init_send_head(struct sock *sk) -{ - sk->sk_send_head = NULL; -} - -static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) -{ - __skb_queue_tail(&sk->sk_write_queue, skb); -} - -static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) -{ - __tcp_add_write_queue_tail(sk, skb); - - /* Queue it, remembering where we must start sending. */ - if (sk->sk_send_head == NULL) { - sk->sk_send_head = skb; - - if (tcp_sk(sk)->highest_sack == NULL) - tcp_sk(sk)->highest_sack = skb; - } -} - -static inline void __tcp_add_write_queue_head(struct sock *sk, struct sk_buff *skb) -{ - __skb_queue_head(&sk->sk_write_queue, skb); -} - -/* Insert buff after skb on the write queue of sk. */ -static inline void tcp_insert_write_queue_after(struct sk_buff *skb, - struct sk_buff *buff, - struct sock *sk) -{ - __skb_queue_after(&sk->sk_write_queue, skb, buff); -} - -/* Insert new before skb on the write queue of sk. */ -static inline void tcp_insert_write_queue_before(struct sk_buff *new, - struct sk_buff *skb, - struct sock *sk) -{ - __skb_queue_before(&sk->sk_write_queue, skb, new); - - if (sk->sk_send_head == skb) - sk->sk_send_head = new; -} - -static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk) -{ - __skb_unlink(skb, &sk->sk_write_queue); -} - -static inline int tcp_write_queue_empty(struct sock *sk) -{ - return skb_queue_empty(&sk->sk_write_queue); -} - -static inline void tcp_push_pending_frames(struct sock *sk) -{ - if (tcp_send_head(sk)) { - struct tcp_sock *tp = tcp_sk(sk); - - __tcp_push_pending_frames(sk, tcp_current_mss(sk), tp->nonagle); - } -} - -/* Start sequence of the skb just after the highest skb with SACKed - * bit, valid only if sacked_out > 0 or when the caller has ensured - * validity by itself. - */ -static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp) -{ - if (!tp->sacked_out) - return tp->snd_una; - - if (tp->highest_sack == NULL) - return tp->snd_nxt; - - return TCP_SKB_CB(tp->highest_sack)->seq; -} - -static inline void tcp_advance_highest_sack(struct sock *sk, struct sk_buff *skb) -{ - tcp_sk(sk)->highest_sack = tcp_skb_is_last(sk, skb) ? NULL : - tcp_write_queue_next(sk, skb); -} - -static inline struct sk_buff *tcp_highest_sack(struct sock *sk) -{ - return tcp_sk(sk)->highest_sack; -} - -static inline void tcp_highest_sack_reset(struct sock *sk) -{ - tcp_sk(sk)->highest_sack = tcp_write_queue_head(sk); -} - -/* Called when old skb is about to be deleted (to be combined with new skb) */ -static inline void tcp_highest_sack_combine(struct sock *sk, - struct sk_buff *old, - struct sk_buff *new) -{ - if (tcp_sk(sk)->sacked_out && (old == tcp_sk(sk)->highest_sack)) - tcp_sk(sk)->highest_sack = new; -} - -/* Determines whether this is a thin stream (which may suffer from - * increased latency). Used to trigger latency-reducing mechanisms. - */ -static inline unsigned int tcp_stream_is_thin(struct tcp_sock *tp) -{ - return tp->packets_out < 4 && !tcp_in_initial_slowstart(tp); -} - -/* /proc */ -enum tcp_seq_states { - TCP_SEQ_STATE_LISTENING, - TCP_SEQ_STATE_OPENREQ, - TCP_SEQ_STATE_ESTABLISHED, - TCP_SEQ_STATE_TIME_WAIT, -}; - -int tcp_seq_open(struct inode *inode, struct file *file); - -struct tcp_seq_afinfo { - char *name; - sa_family_t family; - const struct file_operations *seq_fops; - struct seq_operations seq_ops; -}; - -struct tcp_iter_state { - struct seq_net_private p; - sa_family_t family; - enum tcp_seq_states state; - struct sock *syn_wait_sk; - int bucket, offset, sbucket, num, uid; - loff_t last_pos; -}; - -extern int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo); -extern void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo); - -extern struct request_sock_ops tcp_request_sock_ops; -extern struct request_sock_ops tcp6_request_sock_ops; - -extern void tcp_v4_destroy_sock(struct sock *sk); - -extern int tcp_v4_gso_send_check(struct sk_buff *skb); -extern struct sk_buff *tcp_tso_segment(struct sk_buff *skb, - netdev_features_t features); -extern struct sk_buff **tcp_gro_receive(struct sk_buff **head, - struct sk_buff *skb); -extern struct sk_buff **tcp4_gro_receive(struct sk_buff **head, - struct sk_buff *skb); -extern int tcp_gro_complete(struct sk_buff *skb); -extern int tcp4_gro_complete(struct sk_buff *skb); - -extern int tcp_nuke_addr(struct net *net, struct sockaddr *addr); - -#ifdef CONFIG_PROC_FS -extern int tcp4_proc_init(void); -extern void tcp4_proc_exit(void); -#endif - -/* TCP af-specific functions */ -struct tcp_sock_af_ops { -#ifdef CONFIG_TCP_MD5SIG - struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk, - struct sock *addr_sk); - int (*calc_md5_hash) (char *location, - struct tcp_md5sig_key *md5, - const struct sock *sk, - const struct request_sock *req, - const struct sk_buff *skb); - int (*md5_parse) (struct sock *sk, - char __user *optval, - int optlen); -#endif -}; - -struct tcp_request_sock_ops { -#ifdef CONFIG_TCP_MD5SIG - struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk, - struct request_sock *req); - int (*calc_md5_hash) (char *location, - struct tcp_md5sig_key *md5, - const struct sock *sk, - const struct request_sock *req, - const struct sk_buff *skb); -#endif -}; - -/* Using SHA1 for now, define some constants. - */ -#define COOKIE_DIGEST_WORDS (SHA_DIGEST_WORDS) -#define COOKIE_MESSAGE_WORDS (SHA_MESSAGE_BYTES / 4) -#define COOKIE_WORKSPACE_WORDS (COOKIE_DIGEST_WORDS + COOKIE_MESSAGE_WORDS) - -extern int tcp_cookie_generator(u32 *bakery); - -/** - * struct tcp_cookie_values - each socket needs extra space for the - * cookies, together with (optional) space for any SYN data. - * - * A tcp_sock contains a pointer to the current value, and this is - * cloned to the tcp_timewait_sock. - * - * @cookie_pair: variable data from the option exchange. - * - * @cookie_desired: user specified tcpct_cookie_desired. Zero - * indicates default (sysctl_tcp_cookie_size). - * After cookie sent, remembers size of cookie. - * Range 0, TCP_COOKIE_MIN to TCP_COOKIE_MAX. - * - * @s_data_desired: user specified tcpct_s_data_desired. When the - * constant payload is specified (@s_data_constant), - * holds its length instead. - * Range 0 to TCP_MSS_DESIRED. - * - * @s_data_payload: constant data that is to be included in the - * payload of SYN or SYNACK segments when the - * cookie option is present. - */ -struct tcp_cookie_values { - struct kref kref; - u8 cookie_pair[TCP_COOKIE_PAIR_SIZE]; - u8 cookie_pair_size; - u8 cookie_desired; - u16 s_data_desired:11, - s_data_constant:1, - s_data_in:1, - s_data_out:1, - s_data_unused:2; - u8 s_data_payload[0]; -}; - -static inline void tcp_cookie_values_release(struct kref *kref) -{ - kfree(container_of(kref, struct tcp_cookie_values, kref)); -} - -/* The length of constant payload data. Note that s_data_desired is - * overloaded, depending on s_data_constant: either the length of constant - * data (returned here) or the limit on variable data. - */ -static inline int tcp_s_data_size(const struct tcp_sock *tp) -{ - return (tp->cookie_values != NULL && tp->cookie_values->s_data_constant) - ? tp->cookie_values->s_data_desired - : 0; -} - -/** - * struct tcp_extend_values - tcp_ipv?.c to tcp_output.c workspace. - * - * As tcp_request_sock has already been extended in other places, the - * only remaining method is to pass stack values along as function - * parameters. These parameters are not needed after sending SYNACK. - * - * @cookie_bakery: cryptographic secret and message workspace. - * - * @cookie_plus: bytes in authenticator/cookie option, copied from - * struct tcp_options_received (above). - */ -struct tcp_extend_values { - struct request_values rv; - u32 cookie_bakery[COOKIE_WORKSPACE_WORDS]; - u8 cookie_plus:6, - cookie_out_never:1, - cookie_in_always:1; -}; - -static inline struct tcp_extend_values *tcp_xv(struct request_values *rvp) -{ - return (struct tcp_extend_values *)rvp; -} - -extern void tcp_v4_init(void); -extern void tcp_init(void); - -#endif /* _TCP_H */ |