diff options
Diffstat (limited to 'include/net/tcp.h')
| -rw-r--r-- | include/net/tcp.h | 2771 |
1 files changed, 2063 insertions, 708 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index d1980054ec75..0deb5e9dd911 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1,3 +1,4 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * INET An implementation of the TCP/IP protocol suite for the LINUX * operating system. INET is implemented using the BSD Socket @@ -9,11 +10,6 @@ * * 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 @@ -27,55 +23,86 @@ #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 <linux/ktime.h> +#include <linux/indirect_call_wrapper.h> +#include <linux/bits.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_reuseport.h> #include <net/sock.h> #include <net/snmp.h> #include <net/ip.h> #include <net/tcp_states.h> +#include <net/tcp_ao.h> #include <net/inet_ecn.h> #include <net/dst.h> +#include <net/mptcp.h> +#include <net/xfrm.h> #include <linux/seq_file.h> #include <linux/memcontrol.h> +#include <linux/bpf-cgroup.h> +#include <linux/siphash.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); +DECLARE_PER_CPU(unsigned int, tcp_orphan_count); +int tcp_orphan_count_sum(void); + +static inline void tcp_orphan_count_inc(void) +{ + this_cpu_inc(tcp_orphan_count); +} + +static inline void tcp_orphan_count_dec(void) +{ + this_cpu_dec(tcp_orphan_count); +} + +DECLARE_PER_CPU(u32, tcp_tw_isn); + +void tcp_time_wait(struct sock *sk, int state, int timeo); -#define MAX_TCP_HEADER (128 + MAX_HEADER) +#define MAX_TCP_HEADER L1_CACHE_ALIGN(128 + MAX_HEADER) #define MAX_TCP_OPTION_SPACE 40 +#define TCP_MIN_SND_MSS 48 +#define TCP_MIN_GSO_SIZE (TCP_MIN_SND_MSS - MAX_TCP_OPTION_SPACE) -/* +/* * Never offer a window over 32767 without using window scaling. Some - * poor stacks do signed 16bit maths! + * 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 -/* The least MTU to use for probing */ -#define TCP_BASE_MSS 512 +/* The initial MTU to use for probing */ +#define TCP_BASE_MSS 1024 + +/* probing interval, default to 10 minutes as per RFC4821 */ +#define TCP_PROBE_INTERVAL 600 + +/* Specify interval when tcp mtu probing will stop */ +#define TCP_PROBE_THRESHOLD 8 /* 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 +/* Maximal number of window scale according to RFC1323 */ +#define TCP_MAX_WSCALE 14U + +/* Default sending frequency of accurate ECN option per RTT */ +#define TCP_ACCECN_OPTION_BEACON 3 + /* urg_data states */ #define TCP_URG_VALID 0x0100 #define TCP_URG_NOTYET 0x0200 @@ -119,8 +146,11 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); * to combine FIN-WAIT-2 timeout with * TIME-WAIT timer. */ +#define TCP_FIN_TIMEOUT_MAX (120 * HZ) /* max TCP_LINGER2 value (two minutes) */ #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ +static_assert((1 << ATO_BITS) > TCP_DELACK_MAX); + #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)) @@ -128,8 +158,13 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); #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_RTO_MAX_SEC 120 +#define TCP_RTO_MAX ((unsigned)(TCP_RTO_MAX_SEC * HZ)) +#define TCP_RTO_MIN ((unsigned)(HZ / 5)) +#define TCP_TIMEOUT_MIN (2U) /* Min timeout for TCP timers in jiffies */ + +#define TCP_TIMEOUT_MIN_US (2*USEC_PER_MSEC) /* Min TCP timeout in microsecs */ + #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 @@ -141,7 +176,6 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); #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) @@ -151,9 +185,12 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); #define MAX_TCP_KEEPCNT 127 #define MAX_TCP_SYNCNT 127 -#define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */ +/* Ensure that TCP PAWS checks are relaxed after ~2147 seconds + * to avoid overflows. This assumes a clock smaller than 1 Mhz. + * Default clock is 1 Khz, tcp_usec_ts uses 1 Mhz. + */ +#define TCP_PAWS_WRAP (INT_MAX / USEC_PER_SEC) -#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 @@ -167,7 +204,7 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); /* * TCP option */ - + #define TCPOPT_NOP 1 /* Padding */ #define TCPOPT_EOL 0 /* End of options */ #define TCPOPT_MSS 2 /* Segment size negotiating */ @@ -176,11 +213,17 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); #define TCPOPT_SACK 5 /* SACK Block */ #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ +#define TCPOPT_AO 29 /* Authentication Option (RFC5925) */ +#define TCPOPT_MPTCP 30 /* Multipath TCP (RFC6824) */ +#define TCPOPT_FASTOPEN 34 /* Fast open (RFC7413) */ +#define TCPOPT_ACCECN0 172 /* 0xAC: Accurate ECN Order 0 */ +#define TCPOPT_ACCECN1 174 /* 0xAE: Accurate ECN Order 1 */ #define TCPOPT_EXP 254 /* Experimental */ /* Magic number to be after the option value for sharing TCP * experimental options. See draft-ietf-tcpm-experimental-options-00.txt */ #define TCPOPT_FASTOPEN_MAGIC 0xF989 +#define TCPOPT_SMC_MAGIC 0xE2D4C3D9 /* * TCP option lengths @@ -191,11 +234,10 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); #define TCPOLEN_SACK_PERM 2 #define TCPOLEN_TIMESTAMP 10 #define TCPOLEN_MD5SIG 18 +#define TCPOLEN_FASTOPEN_BASE 2 +#define TCPOLEN_ACCECN_BASE 2 #define TCPOLEN_EXP_FASTOPEN_BASE 4 -#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) +#define TCPOLEN_EXP_SMC_BASE 6 /* But this is what stacks really send out. */ #define TCPOLEN_TSTAMP_ALIGNED 12 @@ -206,6 +248,15 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); #define TCPOLEN_SACK_PERBLOCK 8 #define TCPOLEN_MD5SIG_ALIGNED 20 #define TCPOLEN_MSS_ALIGNED 4 +#define TCPOLEN_EXP_SMC_BASE_ALIGNED 8 +#define TCPOLEN_ACCECN_PERFIELD 3 + +/* Maximum number of byte counters in AccECN option + size */ +#define TCP_ACCECN_NUMFIELDS 3 +#define TCP_ACCECN_MAXSIZE (TCPOLEN_ACCECN_BASE + \ + TCPOLEN_ACCECN_PERFIELD * \ + TCP_ACCECN_NUMFIELDS) +#define TCP_ACCECN_SAFETY_SHIFT 1 /* SAFETY_FACTOR in accecn draft */ /* Flags in tp->nonagle */ #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */ @@ -215,7 +266,7 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); /* 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 */ +/* TCP initial congestion window as per rfc6928 */ #define TCP_INIT_CWND 10 /* Bit Flags for sysctl_tcp_fastopen */ @@ -223,72 +274,40 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); #define TFO_SERVER_ENABLE 2 #define TFO_CLIENT_NO_COOKIE 4 /* Data in SYN w/o cookie option */ -/* Process SYN data but skip cookie validation */ -#define TFO_SERVER_COOKIE_NOT_CHKED 0x100 /* Accept SYN data w/o any cookie option */ #define TFO_SERVER_COOKIE_NOT_REQD 0x200 /* Force enable TFO on all listeners, i.e., not requiring the - * TCP_FASTOPEN socket option. SOCKOPT1/2 determine how to set max_qlen. + * TCP_FASTOPEN socket option. */ #define TFO_SERVER_WO_SOCKOPT1 0x400 -#define TFO_SERVER_WO_SOCKOPT2 0x800 -/* Always create TFO child sockets on a TFO listener even when - * cookie/data not present. (For testing purpose!) - */ -#define TFO_SERVER_ALWAYS 0x1000 -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_fastopen; -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_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_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_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_thin_linear_timeouts; -extern int sysctl_tcp_thin_dupack; -extern int sysctl_tcp_early_retrans; -extern int sysctl_tcp_limit_output_bytes; -extern int sysctl_tcp_challenge_ack_limit; - -extern atomic_long_t tcp_memory_allocated; +extern long sysctl_tcp_mem[3]; + +#define TCP_RACK_LOSS_DETECTION 0x1 /* Use RACK to detect losses */ +#define TCP_RACK_STATIC_REO_WND 0x2 /* Use static RACK reo wnd */ +#define TCP_RACK_NO_DUPTHRESH 0x4 /* Do not use DUPACK threshold in RACK */ + +DECLARE_PER_CPU(int, tcp_memory_per_cpu_fw_alloc); + extern struct percpu_counter tcp_sockets_allocated; -extern int tcp_memory_pressure; +extern unsigned long tcp_memory_pressure; + +/* optimized version of sk_under_memory_pressure() for TCP sockets */ +static inline bool tcp_under_memory_pressure(const struct sock *sk) +{ + if (mem_cgroup_sk_enabled(sk) && + mem_cgroup_sk_under_memory_pressure(sk)) + return true; + if (sk->sk_bypass_prot_mem) + return false; + + return READ_ONCE(tcp_memory_pressure); +} /* * The next routines deal with comparing 32 bit unsigned ints * and worry about wraparound (automatic with unsigned arithmetic). @@ -306,89 +325,73 @@ 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) +static inline void tcp_wmem_free_skb(struct sock *sk, struct sk_buff *skb) { - 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; + sk_wmem_queued_add(sk, -skb->truesize); + if (!skb_zcopy_pure(skb)) + sk_mem_uncharge(sk, skb->truesize); + else + sk_mem_uncharge(sk, SKB_TRUESIZE(skb_end_offset(skb))); + __kfree_skb(skb); } -extern bool tcp_check_oom(struct sock *sk, int shift); +void sk_forced_mem_schedule(struct sock *sk, int size); -/* 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; -} +bool tcp_check_oom(const struct sock *sk, int shift); -/* 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_INC_STATS(net, field) __SNMP_INC_STATS((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_tasklet_init(void); - -extern void tcp_v4_err(struct sk_buff *skb, u32); - -extern void tcp_shutdown (struct sock *sk, int how); - -extern void tcp_v4_early_demux(struct sk_buff *skb); -extern int tcp_v4_rcv(struct sk_buff *skb); - -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 void tcp_release_cb(struct sock *sk); -extern void tcp_wfree(struct sk_buff *skb); -extern void tcp_write_timer_handler(struct sock *sk); -extern void tcp_delack_timer_handler(struct sock *sk); -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) +void tcp_tsq_work_init(void); + +int tcp_v4_err(struct sk_buff *skb, u32); + +void tcp_shutdown(struct sock *sk, int how); + +int tcp_v4_early_demux(struct sk_buff *skb); +int tcp_v4_rcv(struct sk_buff *skb); + +void tcp_remove_empty_skb(struct sock *sk); +int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); +int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size); +int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg, int *copied, + size_t size, struct ubuf_info *uarg); +void tcp_splice_eof(struct socket *sock); +int tcp_send_mss(struct sock *sk, int *size_goal, int flags); +int tcp_wmem_schedule(struct sock *sk, int copy); +void tcp_push(struct sock *sk, int flags, int mss_now, int nonagle, + int size_goal); +void tcp_release_cb(struct sock *sk); +void tcp_wfree(struct sk_buff *skb); +void tcp_write_timer_handler(struct sock *sk); +void tcp_delack_timer_handler(struct sock *sk); +int tcp_ioctl(struct sock *sk, int cmd, int *karg); +enum skb_drop_reason tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb); +void tcp_rcv_established(struct sock *sk, struct sk_buff *skb); +void tcp_rcvbuf_grow(struct sock *sk, u32 newval); +void tcp_rcv_space_adjust(struct sock *sk); +int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); +void tcp_twsk_destructor(struct sock *sk); +void tcp_twsk_purge(struct list_head *net_exit_list); +ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags); +struct sk_buff *tcp_stream_alloc_skb(struct sock *sk, gfp_t gfp, + bool force_schedule); + +static inline void tcp_dec_quickack_mode(struct sock *sk) { struct inet_connection_sock *icsk = inet_csk(sk); if (icsk->icsk_ack.quick) { + /* How many ACKs S/ACKing new data have we sent? */ + const unsigned int pkts = inet_csk_ack_scheduled(sk) ? 1 : 0; + if (pkts >= icsk->icsk_ack.quick) { icsk->icsk_ack.quick = 0; /* Leaving quickack mode we deflate ATO. */ @@ -398,161 +401,388 @@ static inline void tcp_dec_quickack_mode(struct sock *sk, } } -#define TCP_ECN_OK 1 -#define TCP_ECN_QUEUE_CWR 2 -#define TCP_ECN_DEMAND_CWR 4 -#define TCP_ECN_SEEN 8 +#define TCP_ECN_MODE_RFC3168 BIT(0) +#define TCP_ECN_QUEUE_CWR BIT(1) +#define TCP_ECN_DEMAND_CWR BIT(2) +#define TCP_ECN_SEEN BIT(3) +#define TCP_ECN_MODE_ACCECN BIT(4) + +#define TCP_ECN_DISABLED 0 +#define TCP_ECN_MODE_PENDING (TCP_ECN_MODE_RFC3168 | TCP_ECN_MODE_ACCECN) +#define TCP_ECN_MODE_ANY (TCP_ECN_MODE_RFC3168 | TCP_ECN_MODE_ACCECN) + +static inline bool tcp_ecn_mode_any(const struct tcp_sock *tp) +{ + return tp->ecn_flags & TCP_ECN_MODE_ANY; +} + +static inline bool tcp_ecn_mode_rfc3168(const struct tcp_sock *tp) +{ + return (tp->ecn_flags & TCP_ECN_MODE_ANY) == TCP_ECN_MODE_RFC3168; +} + +static inline bool tcp_ecn_mode_accecn(const struct tcp_sock *tp) +{ + return (tp->ecn_flags & TCP_ECN_MODE_ANY) == TCP_ECN_MODE_ACCECN; +} + +static inline bool tcp_ecn_disabled(const struct tcp_sock *tp) +{ + return !tcp_ecn_mode_any(tp); +} + +static inline bool tcp_ecn_mode_pending(const struct tcp_sock *tp) +{ + return (tp->ecn_flags & TCP_ECN_MODE_PENDING) == TCP_ECN_MODE_PENDING; +} + +static inline void tcp_ecn_mode_set(struct tcp_sock *tp, u8 mode) +{ + tp->ecn_flags &= ~TCP_ECN_MODE_ANY; + tp->ecn_flags |= mode; +} enum tcp_tw_status { TCP_TW_SUCCESS = 0, TCP_TW_RST = 1, TCP_TW_ACK = 2, - TCP_TW_SYN = 3 + TCP_TW_SYN = 3, + TCP_TW_ACK_OOW = 4 }; -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, - bool fastopen); -extern int tcp_child_process(struct sock *parent, struct sock *child, - struct sk_buff *skb); -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_init_metrics(struct sock *sk); -extern void tcp_metrics_init(void); -extern bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst, bool paws_check); -extern bool tcp_remember_stamp(struct sock *sk); -extern bool tcp_tw_remember_stamp(struct inet_timewait_sock *tw); -extern void tcp_fetch_timewait_stamp(struct sock *sk, struct dst_entry *dst); -extern void tcp_disable_fack(struct tcp_sock *tp); -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, - int estab, struct tcp_fastopen_cookie *foc); -extern const u8 *tcp_parse_md5sig_option(const struct tcphdr *th); +enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, + struct sk_buff *skb, + const struct tcphdr *th, + u32 *tw_isn, + enum skb_drop_reason *drop_reason); +struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, bool fastopen, + bool *lost_race, enum skb_drop_reason *drop_reason); +enum skb_drop_reason tcp_child_process(struct sock *parent, struct sock *child, + struct sk_buff *skb); +void tcp_enter_loss(struct sock *sk); +void tcp_cwnd_reduction(struct sock *sk, int newly_acked_sacked, int newly_lost, int flag); +void tcp_clear_retrans(struct tcp_sock *tp); +void tcp_update_pacing_rate(struct sock *sk); +void tcp_set_rto(struct sock *sk); +void tcp_update_metrics(struct sock *sk); +void tcp_init_metrics(struct sock *sk); +void tcp_metrics_init(void); +bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst); +void __tcp_close(struct sock *sk, long timeout); +void tcp_close(struct sock *sk, long timeout); +void tcp_init_sock(struct sock *sk); +void tcp_init_transfer(struct sock *sk, int bpf_op, struct sk_buff *skb); +__poll_t tcp_poll(struct file *file, struct socket *sock, + struct poll_table_struct *wait); +int do_tcp_getsockopt(struct sock *sk, int level, + int optname, sockptr_t optval, sockptr_t optlen); +int tcp_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen); +bool tcp_bpf_bypass_getsockopt(int level, int optname); +int do_tcp_setsockopt(struct sock *sk, int level, int optname, + sockptr_t optval, unsigned int optlen); +int tcp_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval, + unsigned int optlen); +void tcp_reset_keepalive_timer(struct sock *sk, unsigned long timeout); +void tcp_set_keepalive(struct sock *sk, int val); +void tcp_syn_ack_timeout(const struct request_sock *req); +int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, + int flags, int *addr_len); +int tcp_set_rcvlowat(struct sock *sk, int val); +int tcp_set_window_clamp(struct sock *sk, int val); +void tcp_update_recv_tstamps(struct sk_buff *skb, + struct scm_timestamping_internal *tss); +void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk, + struct scm_timestamping_internal *tss); +void tcp_data_ready(struct sock *sk); +#ifdef CONFIG_MMU +int tcp_mmap(struct file *file, struct socket *sock, + struct vm_area_struct *vma); +#endif +void tcp_parse_options(const struct net *net, const struct sk_buff *skb, + struct tcp_options_received *opt_rx, + int estab, struct tcp_fastopen_cookie *foc); /* + * BPF SKB-less helpers + */ +u16 tcp_v4_get_syncookie(struct sock *sk, struct iphdr *iph, + struct tcphdr *th, u32 *cookie); +u16 tcp_v6_get_syncookie(struct sock *sk, struct ipv6hdr *iph, + struct tcphdr *th, u32 *cookie); +u16 tcp_parse_mss_option(const struct tcphdr *th, u16 user_mss); +u16 tcp_get_syncookie_mss(struct request_sock_ops *rsk_ops, + const struct tcp_request_sock_ops *af_ops, + struct sock *sk, 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 tcp_fastopen_cookie *foc); -extern int tcp_disconnect(struct sock *sk, int flags); +void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); +void tcp_v4_mtu_reduced(struct sock *sk); +void tcp_req_err(struct sock *sk, u32 seq, bool abort); +void tcp_ld_RTO_revert(struct sock *sk, u32 seq); +int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); +struct sock *tcp_create_openreq_child(const struct sock *sk, + struct request_sock *req, + struct sk_buff *skb); +void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst); +struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct dst_entry *dst, + struct request_sock *req_unhash, + bool *own_req); +int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); +int tcp_v4_connect(struct sock *sk, struct sockaddr_unsized *uaddr, int addr_len); +int tcp_connect(struct sock *sk); +enum tcp_synack_type { + TCP_SYNACK_NORMAL, + TCP_SYNACK_FASTOPEN, + TCP_SYNACK_COOKIE, +}; +struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, + struct request_sock *req, + struct tcp_fastopen_cookie *foc, + enum tcp_synack_type synack_type, + struct sk_buff *syn_skb); +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); void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb); /* 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); +struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct dst_entry *dst); +int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th); +struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb); +struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, + struct sock *sk, struct sk_buff *skb, + struct tcp_options_received *tcp_opt, + int mss, u32 tsoff); + +#if IS_ENABLED(CONFIG_BPF) +struct bpf_tcp_req_attrs { + u32 rcv_tsval; + u32 rcv_tsecr; + u16 mss; + u8 rcv_wscale; + u8 snd_wscale; + u8 ecn_ok; + u8 wscale_ok; + u8 sack_ok; + u8 tstamp_ok; + u8 usec_ts_ok; + u8 reserved[3]; +}; +#endif + #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) + +/* Syncookies use a monotonic timer which increments every 60 seconds. + * This counter is used both as a hash input and partially encoded into + * the cookie value. A cookie is only validated further if the delta + * between the current counter value and the encoded one is less than this, + * i.e. a sent cookie is valid only at most for 2*60 seconds (or less if + * the counter advances immediately after a cookie is generated). + */ +#define MAX_SYNCOOKIE_AGE 2 +#define TCP_SYNCOOKIE_PERIOD (60 * HZ) +#define TCP_SYNCOOKIE_VALID (MAX_SYNCOOKIE_AGE * TCP_SYNCOOKIE_PERIOD) + +/* syncookies: remember time of last synqueue overflow + * But do not dirty this field too often (once per second is enough) + * It is racy as we do not hold a lock, but race is very minor. + */ +static inline void tcp_synq_overflow(const struct sock *sk) +{ + unsigned int last_overflow; + unsigned int now = jiffies; + + if (sk->sk_reuseport) { + struct sock_reuseport *reuse; + + reuse = rcu_dereference(sk->sk_reuseport_cb); + if (likely(reuse)) { + last_overflow = READ_ONCE(reuse->synq_overflow_ts); + if (!time_between32(now, last_overflow, + last_overflow + HZ)) + WRITE_ONCE(reuse->synq_overflow_ts, now); + return; + } + } + + last_overflow = READ_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp); + if (!time_between32(now, last_overflow, last_overflow + HZ)) + WRITE_ONCE(tcp_sk_rw(sk)->rx_opt.ts_recent_stamp, now); +} + +/* syncookies: no recent synqueue overflow on this listening socket? */ +static inline bool tcp_synq_no_recent_overflow(const struct sock *sk) { - return 0; + unsigned int last_overflow; + unsigned int now = jiffies; + + if (sk->sk_reuseport) { + struct sock_reuseport *reuse; + + reuse = rcu_dereference(sk->sk_reuseport_cb); + if (likely(reuse)) { + last_overflow = READ_ONCE(reuse->synq_overflow_ts); + return !time_between32(now, last_overflow - HZ, + last_overflow + + TCP_SYNCOOKIE_VALID); + } + } + + last_overflow = READ_ONCE(tcp_sk(sk)->rx_opt.ts_recent_stamp); + + /* If last_overflow <= jiffies <= last_overflow + TCP_SYNCOOKIE_VALID, + * then we're under synflood. However, we have to use + * 'last_overflow - HZ' as lower bound. That's because a concurrent + * tcp_synq_overflow() could update .ts_recent_stamp after we read + * jiffies but before we store .ts_recent_stamp into last_overflow, + * which could lead to rejecting a valid syncookie. + */ + return !time_between32(now, last_overflow - HZ, + last_overflow + TCP_SYNCOOKIE_VALID); } -#endif -extern __u32 cookie_init_timestamp(struct request_sock *req); -extern bool cookie_check_timestamp(struct tcp_options_received *opt, - struct net *net, bool *ecn_ok); +static inline u32 tcp_cookie_time(void) +{ + u64 val = get_jiffies_64(); -/* 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); + do_div(val, TCP_SYNCOOKIE_PERIOD); + return val; +} + +/* Convert one nsec 64bit timestamp to ts (ms or usec resolution) */ +static inline u64 tcp_ns_to_ts(bool usec_ts, u64 val) +{ + if (usec_ts) + return div_u64(val, NSEC_PER_USEC); + + return div_u64(val, NSEC_PER_MSEC); +} + +u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, + u16 *mssp); +__u32 cookie_v4_init_sequence(const struct sk_buff *skb, __u16 *mss); +u64 cookie_init_timestamp(struct request_sock *req, u64 now); +bool cookie_timestamp_decode(const struct net *net, + struct tcp_options_received *opt); + +static inline bool cookie_ecn_ok(const struct net *net, const struct dst_entry *dst) +{ + return READ_ONCE(net->ipv4.sysctl_tcp_ecn) || + dst_feature(dst, RTAX_FEATURE_ECN); +} + +#if IS_ENABLED(CONFIG_BPF) +static inline bool cookie_bpf_ok(struct sk_buff *skb) +{ + return skb->sk; +} + +struct request_sock *cookie_bpf_check(struct sock *sk, struct sk_buff *skb); #else -static inline __u32 cookie_v6_init_sequence(struct sock *sk, - struct sk_buff *skb, - __u16 *mss) +static inline bool cookie_bpf_ok(struct sk_buff *skb) { - return 0; + return false; +} + +static inline struct request_sock *cookie_bpf_check(struct net *net, struct sock *sk, + struct sk_buff *skb) +{ + return NULL; } #endif + +/* From net/ipv6/syncookies.c */ +int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th); +struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); + +u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, + const struct tcphdr *th, u16 *mssp); +__u32 cookie_v6_init_sequence(const struct sk_buff *skb, __u16 *mss); +#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 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); -extern void tcp_send_loss_probe(struct sock *sk); -extern bool tcp_schedule_loss_probe(struct sock *sk); +void tcp_skb_entail(struct sock *sk, struct sk_buff *skb); +void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb); +void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, + int nonagle); +int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); +int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); +void tcp_retransmit_timer(struct sock *sk); +void tcp_xmit_retransmit_queue(struct sock *); +void tcp_simple_retransmit(struct sock *); +void tcp_enter_recovery(struct sock *sk, bool ece_ack); +int tcp_trim_head(struct sock *, struct sk_buff *, u32); +enum tcp_queue { + TCP_FRAG_IN_WRITE_QUEUE, + TCP_FRAG_IN_RTX_QUEUE, +}; +int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue, + struct sk_buff *skb, u32 len, + unsigned int mss_now, gfp_t gfp); + +void tcp_send_probe0(struct sock *); +int tcp_write_wakeup(struct sock *, int mib); +void tcp_send_fin(struct sock *sk); +void tcp_send_active_reset(struct sock *sk, gfp_t priority, + enum sk_rst_reason reason); +int tcp_send_synack(struct sock *); +void tcp_push_one(struct sock *, unsigned int mss_now); +void __tcp_send_ack(struct sock *sk, u32 rcv_nxt, u16 flags); +void tcp_send_ack(struct sock *sk); +void tcp_send_delayed_ack(struct sock *sk); +void tcp_send_loss_probe(struct sock *sk); +bool tcp_schedule_loss_probe(struct sock *sk, bool advancing_rto); +void tcp_skb_collapse_tstamp(struct sk_buff *skb, + const struct sk_buff *next_skb); /* 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); -extern void tcp_reset(struct sock *sk); +void tcp_rearm_rto(struct sock *sk); +void tcp_synack_rtt_meas(struct sock *sk, struct request_sock *req); +void tcp_done_with_error(struct sock *sk, int err); +void tcp_reset(struct sock *sk, struct sk_buff *skb); +void tcp_fin(struct sock *sk); +void tcp_check_space(struct sock *sk); +void tcp_sack_compress_send_ack(struct sock *sk); + +static inline void tcp_cleanup_skb(struct sk_buff *skb) +{ + skb_dst_drop(skb); + secpath_reset(skb); +} + +static inline void tcp_add_receive_queue(struct sock *sk, struct sk_buff *skb) +{ + DEBUG_NET_WARN_ON_ONCE(skb_dst(skb)); + DEBUG_NET_WARN_ON_ONCE(secpath_exists(skb)); + __skb_queue_tail(&sk->sk_receive_queue, skb); +} /* tcp_timer.c */ -extern void tcp_init_xmit_timers(struct sock *); +void tcp_init_xmit_timers(struct sock *); static inline void tcp_clear_xmit_timers(struct sock *sk) { + if (hrtimer_try_to_cancel(&tcp_sk(sk)->pacing_timer) == 1) + __sock_put(sk); + + if (hrtimer_try_to_cancel(&tcp_sk(sk)->compressed_ack_timer) == 1) + __sock_put(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); +unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); +unsigned int tcp_current_mss(struct sock *sk); +u32 tcp_clamp_probe0_to_user_timeout(const struct sock *sk, u32 when); /* 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) @@ -566,7 +796,7 @@ static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) * 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) + if (tp->max_window > TCP_MSS_DEFAULT) cutoff = (tp->max_window >> 1); else cutoff = tp->max_window; @@ -578,69 +808,76 @@ static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) } /* tcp.c */ -extern void tcp_get_info(const struct sock *, struct tcp_info *); +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); +int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, + sk_read_actor_t recv_actor); +int tcp_read_sock_noack(struct sock *sk, read_descriptor_t *desc, + sk_read_actor_t recv_actor, bool noack, + u32 *copied_seq); +int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor); +struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off); +void tcp_read_done(struct sock *sk, size_t len); -extern void tcp_initialize_rcv_mss(struct sock *sk); +void tcp_initialize_rcv_mss(struct sock *sk); -extern int tcp_mtu_to_mss(struct sock *sk, int pmtu); -extern int tcp_mss_to_mtu(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); -extern void tcp_init_buffer_space(struct sock *sk); +int tcp_mtu_to_mss(struct sock *sk, int pmtu); +int tcp_mss_to_mtu(struct sock *sk, int mss); +void tcp_mtup_init(struct sock *sk); -static inline void tcp_bound_rto(const struct sock *sk) +static inline unsigned int tcp_rto_max(const struct sock *sk) { - if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX) - inet_csk(sk)->icsk_rto = TCP_RTO_MAX; + return READ_ONCE(inet_csk(sk)->icsk_rto_max); } -static inline u32 __tcp_set_rto(const struct tcp_sock *tp) +static inline void tcp_bound_rto(struct sock *sk) { - return (tp->srtt >> 3) + tp->rttvar; + inet_csk(sk)->icsk_rto = min(inet_csk(sk)->icsk_rto, tcp_rto_max(sk)); } -extern void tcp_set_rto(struct sock *sk); - -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) +static inline u32 __tcp_set_rto(const struct tcp_sock *tp) { - __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale); + return usecs_to_jiffies((tp->srtt_us >> 3) + tp->rttvar_us); } -static inline void tcp_fast_path_check(struct sock *sk) +static inline unsigned long tcp_reqsk_timeout(struct request_sock *req) { - struct tcp_sock *tp = tcp_sk(sk); + u64 timeout = (u64)req->timeout << req->num_timeout; - 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); + return (unsigned long)min_t(u64, timeout, + tcp_rto_max(req->rsk_listener)); } +u32 tcp_delack_max(const struct sock *sk); + /* Compute the actual rto_min value */ -static inline u32 tcp_rto_min(struct sock *sk) +static inline u32 tcp_rto_min(const struct sock *sk) { const struct dst_entry *dst = __sk_dst_get(sk); - u32 rto_min = TCP_RTO_MIN; + u32 rto_min = READ_ONCE(inet_csk(sk)->icsk_rto_min); if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); return rto_min; } +static inline u32 tcp_rto_min_us(const struct sock *sk) +{ + return jiffies_to_usecs(tcp_rto_min(sk)); +} + +static inline bool tcp_ca_dst_locked(const struct dst_entry *dst) +{ + return dst_metric_locked(dst, RTAX_CC_ALGO); +} + +/* Minimum RTT in usec. ~0 means not available. */ +static inline u32 tcp_min_rtt(const struct tcp_sock *tp) +{ + return minmax_get(&tp->rtt_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. @@ -658,28 +895,136 @@ static inline u32 tcp_receive_window(const struct tcp_sock *tp) * 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); +u32 __tcp_select_window(struct sock *sk); void tcp_send_window_probe(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. +/* TCP uses 32bit jiffies to save some space. + * Note that this is different from tcp_time_stamp, which + * historically has been the same until linux-4.13. */ -#define tcp_time_stamp ((__u32)(jiffies)) +#define tcp_jiffies32 ((u32)jiffies) + +/* + * Deliver a 32bit value for TCP timestamp option (RFC 7323) + * It is no longer tied to jiffies, but to 1 ms clock. + * Note: double check if you want to use tcp_jiffies32 instead of this. + */ +#define TCP_TS_HZ 1000 + +static inline u64 tcp_clock_ns(void) +{ + return ktime_get_ns(); +} + +static inline u64 tcp_clock_us(void) +{ + return div_u64(tcp_clock_ns(), NSEC_PER_USEC); +} + +static inline u64 tcp_clock_ms(void) +{ + return div_u64(tcp_clock_ns(), NSEC_PER_MSEC); +} + +/* TCP Timestamp included in TS option (RFC 1323) can either use ms + * or usec resolution. Each socket carries a flag to select one or other + * resolution, as the route attribute could change anytime. + * Each flow must stick to initial resolution. + */ +static inline u32 tcp_clock_ts(bool usec_ts) +{ + return usec_ts ? tcp_clock_us() : tcp_clock_ms(); +} + +static inline u32 tcp_time_stamp_ms(const struct tcp_sock *tp) +{ + return div_u64(tp->tcp_mstamp, USEC_PER_MSEC); +} + +static inline u32 tcp_time_stamp_ts(const struct tcp_sock *tp) +{ + if (tp->tcp_usec_ts) + return tp->tcp_mstamp; + return tcp_time_stamp_ms(tp); +} + +void tcp_mstamp_refresh(struct tcp_sock *tp); + +static inline u32 tcp_stamp_us_delta(u64 t1, u64 t0) +{ + return max_t(s64, t1 - t0, 0); +} + +/* provide the departure time in us unit */ +static inline u64 tcp_skb_timestamp_us(const struct sk_buff *skb) +{ + return div_u64(skb->skb_mstamp_ns, NSEC_PER_USEC); +} + +/* Provide skb TSval in usec or ms unit */ +static inline u32 tcp_skb_timestamp_ts(bool usec_ts, const struct sk_buff *skb) +{ + if (usec_ts) + return tcp_skb_timestamp_us(skb); + + return div_u64(skb->skb_mstamp_ns, NSEC_PER_MSEC); +} + +static inline u32 tcp_tw_tsval(const struct tcp_timewait_sock *tcptw) +{ + return tcp_clock_ts(tcptw->tw_sk.tw_usec_ts) + tcptw->tw_ts_offset; +} + +static inline u32 tcp_rsk_tsval(const struct tcp_request_sock *treq) +{ + return tcp_clock_ts(treq->req_usec_ts) + treq->ts_off; +} #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 +#define TCPHDR_FIN BIT(0) +#define TCPHDR_SYN BIT(1) +#define TCPHDR_RST BIT(2) +#define TCPHDR_PSH BIT(3) +#define TCPHDR_ACK BIT(4) +#define TCPHDR_URG BIT(5) +#define TCPHDR_ECE BIT(6) +#define TCPHDR_CWR BIT(7) +#define TCPHDR_AE BIT(8) +#define TCPHDR_FLAGS_MASK (TCPHDR_FIN | TCPHDR_SYN | TCPHDR_RST | \ + TCPHDR_PSH | TCPHDR_ACK | TCPHDR_URG | \ + TCPHDR_ECE | TCPHDR_CWR | TCPHDR_AE) +#define tcp_flags_ntohs(th) (ntohs(*(__be16 *)&tcp_flag_word(th)) & \ + TCPHDR_FLAGS_MASK) + +#define TCPHDR_ACE (TCPHDR_ECE | TCPHDR_CWR | TCPHDR_AE) +#define TCPHDR_SYN_ECN (TCPHDR_SYN | TCPHDR_ECE | TCPHDR_CWR) +#define TCPHDR_SYNACK_ACCECN (TCPHDR_SYN | TCPHDR_ACK | TCPHDR_CWR) + +#define TCP_ACCECN_CEP_ACE_MASK 0x7 +#define TCP_ACCECN_ACE_MAX_DELTA 6 + +/* To avoid/detect middlebox interference, not all counters start at 0. + * See draft-ietf-tcpm-accurate-ecn for the latest values. + */ +#define TCP_ACCECN_CEP_INIT_OFFSET 5 +#define TCP_ACCECN_E1B_INIT_OFFSET 1 +#define TCP_ACCECN_E0B_INIT_OFFSET 1 +#define TCP_ACCECN_CEB_INIT_OFFSET 0 + +/* State flags for sacked in struct tcp_skb_cb */ +enum tcp_skb_cb_sacked_flags { + TCPCB_SACKED_ACKED = (1 << 0), /* SKB ACK'd by a SACK block */ + TCPCB_SACKED_RETRANS = (1 << 1), /* SKB retransmitted */ + TCPCB_LOST = (1 << 2), /* SKB is lost */ + TCPCB_TAGBITS = (TCPCB_SACKED_ACKED | TCPCB_SACKED_RETRANS | + TCPCB_LOST), /* All tag bits */ + TCPCB_REPAIRED = (1 << 4), /* SKB repaired (no skb_mstamp_ns) */ + TCPCB_EVER_RETRANS = (1 << 7), /* Ever retransmitted frame */ + TCPCB_RETRANS = (TCPCB_SACKED_RETRANS | TCPCB_EVER_RETRANS | + TCPCB_REPAIRED), +}; /* This is what the send packet queuing engine uses to pass * TCP per-packet control information to the transmission code. @@ -688,47 +1033,98 @@ void tcp_send_window_probe(struct sock *sk); * 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 */ -#define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */ -#define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS) - + union { + /* Note : + * tcp_gso_segs/size are used in write queue only, + * cf tcp_skb_pcount()/tcp_skb_mss() + */ + struct { + u16 tcp_gso_segs; + u16 tcp_gso_size; + }; + }; + __u16 tcp_flags; /* TCP header flags (tcp[12-13])*/ + + __u8 sacked; /* State flags for SACK. */ __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ - /* 1 byte hole */ +#define TSTAMP_ACK_SK 0x1 +#define TSTAMP_ACK_BPF 0x2 + __u8 txstamp_ack:2, /* Record TX timestamp for ack? */ + eor:1, /* Is skb MSG_EOR marked? */ + has_rxtstamp:1, /* SKB has a RX timestamp */ + unused:4; __u32 ack_seq; /* Sequence number ACK'd */ + union { + struct { +#define TCPCB_DELIVERED_CE_MASK ((1U<<20) - 1) + /* There is space for up to 24 bytes */ + __u32 is_app_limited:1, /* cwnd not fully used? */ + delivered_ce:20, + unused:11; + /* pkts S/ACKed so far upon tx of skb, incl retrans: */ + __u32 delivered; + /* start of send pipeline phase */ + u64 first_tx_mstamp; + /* when we reached the "delivered" count */ + u64 delivered_mstamp; + } tx; /* only used for outgoing skbs */ + union { + struct inet_skb_parm h4; +#if IS_ENABLED(CONFIG_IPV6) + struct inet6_skb_parm h6; +#endif + } header; /* For incoming skbs */ + }; }; #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) -/* RFC3168 : 6.1.1 SYN packets must not have ECT/ECN bits set - * - * If we receive a SYN packet with these bits set, it means a network is - * playing bad games with TOS bits. In order to avoid possible false congestion - * notifications, we disable TCP ECN negociation. +extern const struct inet_connection_sock_af_ops ipv4_specific; + +#if IS_ENABLED(CONFIG_IPV6) +/* This is the variant of inet6_iif() that must be used by TCP, + * as TCP moves IP6CB into a different location in skb->cb[] */ -static inline void -TCP_ECN_create_request(struct request_sock *req, const struct sk_buff *skb, - struct net *net) +static inline int tcp_v6_iif(const struct sk_buff *skb) +{ + return TCP_SKB_CB(skb)->header.h6.iif; +} + +static inline int tcp_v6_iif_l3_slave(const struct sk_buff *skb) { - const struct tcphdr *th = tcp_hdr(skb); + bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); + + return l3_slave ? skb->skb_iif : TCP_SKB_CB(skb)->header.h6.iif; +} + +/* TCP_SKB_CB reference means this can not be used from early demux */ +static inline int tcp_v6_sdif(const struct sk_buff *skb) +{ +#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) + if (skb && ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags)) + return TCP_SKB_CB(skb)->header.h6.iif; +#endif + return 0; +} + +extern const struct inet_connection_sock_af_ops ipv6_specific; + +INDIRECT_CALLABLE_DECLARE(void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)); +INDIRECT_CALLABLE_DECLARE(int tcp_v6_rcv(struct sk_buff *skb)); +void tcp_v6_early_demux(struct sk_buff *skb); + +#endif - if (net->ipv4.sysctl_tcp_ecn && th->ece && th->cwr && - INET_ECN_is_not_ect(TCP_SKB_CB(skb)->ip_dsfield)) - inet_rsk(req)->ecn_ok = 1; +/* TCP_SKB_CB reference means this can not be used from early demux */ +static inline int tcp_v4_sdif(struct sk_buff *skb) +{ +#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) + if (skb && ipv4_l3mdev_skb(TCP_SKB_CB(skb)->header.h4.flags)) + return TCP_SKB_CB(skb)->header.h4.iif; +#endif + return 0; } /* Due to TSO, an SKB can be composed of multiple actual @@ -736,13 +1132,45 @@ TCP_ECN_create_request(struct request_sock *req, const struct sk_buff *skb, */ static inline int tcp_skb_pcount(const struct sk_buff *skb) { - return skb_shinfo(skb)->gso_segs; + return TCP_SKB_CB(skb)->tcp_gso_segs; +} + +static inline void tcp_skb_pcount_set(struct sk_buff *skb, int segs) +{ + TCP_SKB_CB(skb)->tcp_gso_segs = segs; } -/* This is valid iff tcp_skb_pcount() > 1. */ +static inline void tcp_skb_pcount_add(struct sk_buff *skb, int segs) +{ + TCP_SKB_CB(skb)->tcp_gso_segs += segs; +} + +/* This is valid iff skb is in write queue and tcp_skb_pcount() > 1. */ static inline int tcp_skb_mss(const struct sk_buff *skb) { - return skb_shinfo(skb)->gso_size; + return TCP_SKB_CB(skb)->tcp_gso_size; +} + +static inline bool tcp_skb_can_collapse_to(const struct sk_buff *skb) +{ + return likely(!TCP_SKB_CB(skb)->eor); +} + +static inline bool tcp_skb_can_collapse(const struct sk_buff *to, + const struct sk_buff *from) +{ + /* skb_cmp_decrypted() not needed, use tcp_write_collapse_fence() */ + return likely(tcp_skb_can_collapse_to(to) && + mptcp_skb_can_collapse(to, from) && + skb_pure_zcopy_same(to, from) && + skb_frags_readable(to) == skb_frags_readable(from)); +} + +static inline bool tcp_skb_can_collapse_rx(const struct sk_buff *to, + const struct sk_buff *from) +{ + return likely(mptcp_skb_can_collapse(to, from) && + !skb_cmp_decrypted(to, from)); } /* Events passed to congestion control interface */ @@ -751,8 +1179,15 @@ enum tcp_ca_event { CA_EVENT_CWND_RESTART, /* congestion window restart */ CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ CA_EVENT_LOSS, /* loss timeout */ - CA_EVENT_FAST_ACK, /* in sequence ack */ - CA_EVENT_SLOW_ACK, /* other ack */ + CA_EVENT_ECN_NO_CE, /* ECT set, but not CE marked */ + CA_EVENT_ECN_IS_CE, /* received CE marked IP packet */ +}; + +/* Information about inbound ACK, passed to cong_ops->in_ack_event() */ +enum tcp_ca_ack_event_flags { + CA_ACK_SLOWPATH = (1 << 0), /* In slow path processing */ + CA_ACK_WIN_UPDATE = (1 << 1), /* ACK updated window */ + CA_ACK_ECE = (1 << 2), /* ECE bit is set on ack */ }; /* @@ -762,66 +1197,142 @@ enum tcp_ca_event { #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 +#define TCP_CA_UNSPEC 0 -struct tcp_congestion_ops { - struct list_head list; - unsigned long flags; +/* Algorithm can be set on socket without CAP_NET_ADMIN privileges */ +#define TCP_CONG_NON_RESTRICTED BIT(0) +/* Requires ECN/ECT set on all packets */ +#define TCP_CONG_NEEDS_ECN BIT(1) +#define TCP_CONG_MASK (TCP_CONG_NON_RESTRICTED | TCP_CONG_NEEDS_ECN) - /* initialize private data (optional) */ - void (*init)(struct sock *sk); - /* cleanup private data (optional) */ - void (*release)(struct sock *sk); +union tcp_cc_info; + +struct ack_sample { + u32 pkts_acked; + s32 rtt_us; + u32 in_flight; +}; + +/* A rate sample measures the number of (original/retransmitted) data + * packets delivered "delivered" over an interval of time "interval_us". + * The tcp_rate.c code fills in the rate sample, and congestion + * control modules that define a cong_control function to run at the end + * of ACK processing can optionally chose to consult this sample when + * setting cwnd and pacing rate. + * A sample is invalid if "delivered" or "interval_us" is negative. + */ +struct rate_sample { + u64 prior_mstamp; /* starting timestamp for interval */ + u32 prior_delivered; /* tp->delivered at "prior_mstamp" */ + u32 prior_delivered_ce;/* tp->delivered_ce at "prior_mstamp" */ + s32 delivered; /* number of packets delivered over interval */ + s32 delivered_ce; /* number of packets delivered w/ CE marks*/ + long interval_us; /* time for tp->delivered to incr "delivered" */ + u32 snd_interval_us; /* snd interval for delivered packets */ + u32 rcv_interval_us; /* rcv interval for delivered packets */ + long rtt_us; /* RTT of last (S)ACKed packet (or -1) */ + int losses; /* number of packets marked lost upon ACK */ + u32 acked_sacked; /* number of packets newly (S)ACKed upon ACK */ + u32 prior_in_flight; /* in flight before this ACK */ + u32 last_end_seq; /* end_seq of most recently ACKed packet */ + bool is_app_limited; /* is sample from packet with bubble in pipe? */ + bool is_retrans; /* is sample from retransmission? */ + bool is_ack_delayed; /* is this (likely) a delayed ACK? */ +}; + +struct tcp_congestion_ops { +/* fast path fields are put first to fill one cache line */ /* 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); + void (*cong_avoid)(struct sock *sk, u32 ack, u32 acked); + /* 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); + + /* call when ack arrives (optional) */ + void (*in_ack_event)(struct sock *sk, u32 flags); + /* hook for packet ack accounting (optional) */ - void (*pkts_acked)(struct sock *sk, u32 num_acked, s32 rtt_us); + void (*pkts_acked)(struct sock *sk, const struct ack_sample *sample); + + /* override sysctl_tcp_min_tso_segs */ + u32 (*min_tso_segs)(struct sock *sk); + + /* call when packets are delivered to update cwnd and pacing rate, + * after all the ca_state processing. (optional) + */ + void (*cong_control)(struct sock *sk, u32 ack, int flag, const struct rate_sample *rs); + + + /* new value of cwnd after loss (required) */ + u32 (*undo_cwnd)(struct sock *sk); + /* returns the multiplier used in tcp_sndbuf_expand (optional) */ + u32 (*sndbuf_expand)(struct sock *sk); + +/* control/slow paths put last */ /* get info for inet_diag (optional) */ - void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb); + size_t (*get_info)(struct sock *sk, u32 ext, int *attr, + union tcp_cc_info *info); - char name[TCP_CA_NAME_MAX]; - struct module *owner; -}; + char name[TCP_CA_NAME_MAX]; + struct module *owner; + struct list_head list; + u32 key; + u32 flags; -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); + /* initialize private data (optional) */ + void (*init)(struct sock *sk); + /* cleanup private data (optional) */ + void (*release)(struct sock *sk); +} ____cacheline_aligned_in_smp; + +int tcp_register_congestion_control(struct tcp_congestion_ops *type); +void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); +int tcp_update_congestion_control(struct tcp_congestion_ops *type, + struct tcp_congestion_ops *old_type); +int tcp_validate_congestion_control(struct tcp_congestion_ops *ca); + +void tcp_assign_congestion_control(struct sock *sk); +void tcp_init_congestion_control(struct sock *sk); +void tcp_cleanup_congestion_control(struct sock *sk); +int tcp_set_default_congestion_control(struct net *net, const char *name); +void tcp_get_default_congestion_control(struct net *net, char *name); +void tcp_get_available_congestion_control(char *buf, size_t len); +void tcp_get_allowed_congestion_control(char *buf, size_t len); +int tcp_set_allowed_congestion_control(char *allowed); +int tcp_set_congestion_control(struct sock *sk, const char *name, bool load, + bool cap_net_admin); +u32 tcp_slow_start(struct tcp_sock *tp, u32 acked); +void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w, u32 acked); + +u32 tcp_reno_ssthresh(struct sock *sk); +u32 tcp_reno_undo_cwnd(struct sock *sk); +void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 acked); extern struct tcp_congestion_ops tcp_reno; -static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state) +struct tcp_congestion_ops *tcp_ca_find(const char *name); +struct tcp_congestion_ops *tcp_ca_find_key(u32 key); +u32 tcp_ca_get_key_by_name(const char *name, bool *ecn_ca); +#ifdef CONFIG_INET +char *tcp_ca_get_name_by_key(u32 key, char *buffer); +#else +static inline char *tcp_ca_get_name_by_key(u32 key, char *buffer) { - struct inet_connection_sock *icsk = inet_csk(sk); + return NULL; +} +#endif - if (icsk->icsk_ca_ops->set_state) - icsk->icsk_ca_ops->set_state(sk, ca_state); - icsk->icsk_ca_state = ca_state; +static inline bool tcp_ca_needs_ecn(const struct sock *sk) +{ + const struct inet_connection_sock *icsk = inet_csk(sk); + + return icsk->icsk_ca_ops->flags & TCP_CONG_NEEDS_ECN; } static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) @@ -832,17 +1343,32 @@ static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) icsk->icsk_ca_ops->cwnd_event(sk, event); } +/* From tcp_cong.c */ +void tcp_set_ca_state(struct sock *sk, const u8 ca_state); + +/* From tcp_rate.c */ +void tcp_rate_skb_sent(struct sock *sk, struct sk_buff *skb); +void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb, + struct rate_sample *rs); +void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost, + bool is_sack_reneg, struct rate_sample *rs); +void tcp_rate_check_app_limited(struct sock *sk); + +static inline bool tcp_skb_sent_after(u64 t1, u64 t2, u32 seq1, u32 seq2) +{ + return t1 > t2 || (t1 == t2 && after(seq1, seq2)); +} + /* 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; + return likely(tp->rx_opt.sack_ok); } static inline bool tcp_is_reno(const struct tcp_sock *tp) @@ -850,31 +1376,6 @@ static inline bool tcp_is_reno(const struct tcp_sock *tp) return !tcp_is_sack(tp); } -static inline bool 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; -} - -/* TCP early-retransmit (ER) is similar to but more conservative than - * the thin-dupack feature. Enable ER only if thin-dupack is disabled. - */ -static inline void tcp_enable_early_retrans(struct tcp_sock *tp) -{ - tp->do_early_retrans = sysctl_tcp_early_retrans && - sysctl_tcp_early_retrans < 4 && !sysctl_tcp_thin_dupack && - sysctl_tcp_reordering == 3; -} - -static inline void tcp_disable_early_retrans(struct tcp_sock *tp) -{ - tp->do_early_retrans = 0; -} - static inline unsigned int tcp_left_out(const struct tcp_sock *tp) { return tp->sacked_out + tp->lost_out; @@ -901,6 +1402,22 @@ static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp) #define TCP_INFINITE_SSTHRESH 0x7fffffff +static inline u32 tcp_snd_cwnd(const struct tcp_sock *tp) +{ + return tp->snd_cwnd; +} + +static inline void tcp_snd_cwnd_set(struct tcp_sock *tp, u32 val) +{ + WARN_ON_ONCE((int)val <= 0); + tp->snd_cwnd = val; +} + +static inline bool tcp_in_slow_start(const struct tcp_sock *tp) +{ + return tcp_snd_cwnd(tp) < tp->snd_ssthresh; +} + static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) { return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; @@ -924,15 +1441,15 @@ static inline __u32 tcp_current_ssthresh(const struct sock *sk) return tp->snd_ssthresh; else return max(tp->snd_ssthresh, - ((tp->snd_cwnd >> 1) + - (tp->snd_cwnd >> 2))); + ((tcp_snd_cwnd(tp) >> 1) + + (tcp_snd_cwnd(tp) >> 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); +void tcp_enter_cwr(struct sock *sk); +__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. @@ -942,39 +1459,98 @@ 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. +/* 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; +} + +/* We follow the spirit of RFC2861 to validate cwnd but implement a more + * flexible approach. The RFC suggests cwnd should not be raised unless + * it was fully used previously. And that's exactly what we do in + * congestion avoidance mode. But in slow start we allow cwnd to grow + * as long as the application has used half the cwnd. + * Example : + * cwnd is 10 (IW10), but application sends 9 frames. + * We allow cwnd to reach 18 when all frames are ACKed. + * This check is safe because it's as aggressive as slow start which already + * risks 100% overshoot. The advantage is that we discourage application to + * either send more filler packets or data to artificially blow up the cwnd + * usage, and allow application-limited process to probe bw more aggressively. */ -static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp) +static inline bool tcp_is_cwnd_limited(const struct sock *sk) { - return tp->reordering; + const struct tcp_sock *tp = tcp_sk(sk); + + if (tp->is_cwnd_limited) + return true; + + /* If in slow start, ensure cwnd grows to twice what was ACKed. */ + if (tcp_in_slow_start(tp)) + return tcp_snd_cwnd(tp) < 2 * tp->max_packets_out; + + return false; } -/* Returns end sequence number of the receiver's advertised window */ -static inline u32 tcp_wnd_end(const struct tcp_sock *tp) +/* BBR congestion control needs pacing. + * Same remark for SO_MAX_PACING_RATE. + * sch_fq packet scheduler is efficiently handling pacing, + * but is not always installed/used. + * Return true if TCP stack should pace packets itself. + */ +static inline bool tcp_needs_internal_pacing(const struct sock *sk) { - return tp->snd_una + tp->snd_wnd; + return smp_load_acquire(&sk->sk_pacing_status) == SK_PACING_NEEDED; } -extern bool 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) +/* Estimates in how many jiffies next packet for this flow can be sent. + * Scheduling a retransmit timer too early would be silly. + */ +static inline unsigned long tcp_pacing_delay(const struct sock *sk) { - if (skb->len < mss) - tp->snd_sml = TCP_SKB_CB(skb)->end_seq; + s64 delay = tcp_sk(sk)->tcp_wstamp_ns - tcp_sk(sk)->tcp_clock_cache; + + return delay > 0 ? nsecs_to_jiffies(delay) : 0; } -static inline void tcp_check_probe_timer(struct sock *sk) +static inline void tcp_reset_xmit_timer(struct sock *sk, + const int what, + unsigned long when, + bool pace_delay) { - const struct tcp_sock *tp = tcp_sk(sk); - const struct inet_connection_sock *icsk = inet_csk(sk); + if (pace_delay) + when += tcp_pacing_delay(sk); + inet_csk_reset_xmit_timer(sk, what, when, + tcp_rto_max(sk)); +} + +/* Something is really bad, we could not queue an additional packet, + * because qdisc is full or receiver sent a 0 window, or we are paced. + * We do not want to add fuel to the fire, or abort too early, + * so make sure the timer we arm now is at least 200ms in the future, + * regardless of current icsk_rto value (as it could be ~2ms) + */ +static inline unsigned long tcp_probe0_base(const struct sock *sk) +{ + return max_t(unsigned long, inet_csk(sk)->icsk_rto, TCP_RTO_MIN); +} + +/* Variant of inet_csk_rto_backoff() used for zero window probes */ +static inline unsigned long tcp_probe0_when(const struct sock *sk, + unsigned long max_when) +{ + u8 backoff = min_t(u8, ilog2(TCP_RTO_MAX / TCP_RTO_MIN) + 1, + inet_csk(sk)->icsk_backoff); + u64 when = (u64)tcp_probe0_base(sk) << backoff; - if (!tp->packets_out && !icsk->icsk_pending) - inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0, - icsk->icsk_rto, TCP_RTO_MAX); + return (unsigned long)min_t(u64, when, max_when); +} + +static inline void tcp_check_probe_timer(struct sock *sk) +{ + if (!tcp_sk(sk)->packets_out && !inet_csk(sk)->icsk_pending) + tcp_reset_xmit_timer(sk, ICSK_TIME_PROBE0, + tcp_probe0_base(sk), true); } static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) @@ -993,144 +1569,207 @@ static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq) static inline __sum16 tcp_v4_check(int len, __be32 saddr, __be32 daddr, __wsum base) { - return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base); + return csum_tcpudp_magic(saddr, daddr, len, IPPROTO_TCP, base); } -static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb) +static inline bool tcp_checksum_complete(struct sk_buff *skb) { - return __skb_checksum_complete(skb); + return !skb_csum_unnecessary(skb) && + __skb_checksum_complete(skb); } -static inline bool tcp_checksum_complete(struct sk_buff *skb) +bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb, + enum skb_drop_reason *reason); + + +int tcp_filter(struct sock *sk, struct sk_buff *skb, enum skb_drop_reason *reason); +void tcp_set_state(struct sock *sk, int state); +void tcp_done(struct sock *sk); +int tcp_abort(struct sock *sk, int err); + +static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) { - return !skb_csum_unnecessary(skb) && - __tcp_checksum_complete(skb); + rx_opt->dsack = 0; + rx_opt->num_sacks = 0; } -/* Prequeue for VJ style copy to user, combined with checksumming. */ +void tcp_cwnd_restart(struct sock *sk, s32 delta); -static inline void tcp_prequeue_init(struct tcp_sock *tp) +static inline void tcp_slow_start_after_idle_check(struct sock *sk) { - 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 + const struct tcp_congestion_ops *ca_ops = inet_csk(sk)->icsk_ca_ops; + struct tcp_sock *tp = tcp_sk(sk); + s32 delta; + + if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_slow_start_after_idle) || + tp->packets_out || ca_ops->cong_control) + return; + delta = tcp_jiffies32 - tp->lsndtime; + if (delta > inet_csk(sk)->icsk_rto) + tcp_cwnd_restart(sk, delta); } -extern bool tcp_prequeue(struct sock *sk, struct sk_buff *skb); +/* Determine a window scaling and initial window to offer. */ +void tcp_select_initial_window(const struct sock *sk, int __space, + __u32 mss, __u32 *rcv_wnd, + __u32 *window_clamp, int wscale_ok, + __u8 *rcv_wscale, __u32 init_rcv_wnd); -#undef STATE_TRACE +static inline int __tcp_win_from_space(u8 scaling_ratio, int space) +{ + s64 scaled_space = (s64)space * scaling_ratio; -#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); + return scaled_space >> TCP_RMEM_TO_WIN_SCALE; +} -extern void tcp_done(struct sock *sk); +static inline int tcp_win_from_space(const struct sock *sk, int space) +{ + return __tcp_win_from_space(tcp_sk(sk)->scaling_ratio, space); +} -static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) +/* inverse of __tcp_win_from_space() */ +static inline int __tcp_space_from_win(u8 scaling_ratio, int win) { - rx_opt->dsack = 0; - rx_opt->num_sacks = 0; + u64 val = (u64)win << TCP_RMEM_TO_WIN_SCALE; + + do_div(val, scaling_ratio); + return val; } -extern u32 tcp_default_init_rwnd(u32 mss); +static inline int tcp_space_from_win(const struct sock *sk, int win) +{ + return __tcp_space_from_win(tcp_sk(sk)->scaling_ratio, win); +} -/* 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); +/* Assume a 50% default for skb->len/skb->truesize ratio. + * This may be adjusted later in tcp_measure_rcv_mss(). + */ +#define TCP_DEFAULT_SCALING_RATIO (1 << (TCP_RMEM_TO_WIN_SCALE - 1)) -static inline int tcp_win_from_space(int space) +static inline void tcp_scaling_ratio_init(struct sock *sk) { - return sysctl_tcp_adv_win_scale<=0 ? - (space>>(-sysctl_tcp_adv_win_scale)) : - space - (space>>sysctl_tcp_adv_win_scale); + tcp_sk(sk)->scaling_ratio = TCP_DEFAULT_SCALING_RATIO; } -/* Note: caller must be prepared to deal with negative returns */ +/* 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 - + return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf) - + READ_ONCE(sk->sk_backlog.len) - atomic_read(&sk->sk_rmem_alloc)); -} +} static inline int tcp_full_space(const struct sock *sk) { - return tcp_win_from_space(sk->sk_rcvbuf); + return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf)); } -static inline void tcp_openreq_init(struct request_sock *req, - struct tcp_options_received *rx_opt, - struct sk_buff *skb) +static inline void __tcp_adjust_rcv_ssthresh(struct sock *sk, u32 new_ssthresh) { - struct inet_request_sock *ireq = inet_rsk(req); + int unused_mem = sk_unused_reserved_mem(sk); + struct tcp_sock *tp = tcp_sk(sk); - req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */ - req->cookie_ts = 0; - tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq; - tcp_rsk(req)->rcv_nxt = TCP_SKB_CB(skb)->seq + 1; - tcp_rsk(req)->snt_synack = 0; - 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; + tp->rcv_ssthresh = min(tp->rcv_ssthresh, new_ssthresh); + if (unused_mem) + tp->rcv_ssthresh = max_t(u32, tp->rcv_ssthresh, + tcp_win_from_space(sk, unused_mem)); } -/* Compute time elapsed between SYNACK and the ACK completing 3WHS */ -static inline void tcp_synack_rtt_meas(struct sock *sk, - struct request_sock *req) +static inline void tcp_adjust_rcv_ssthresh(struct sock *sk) { - if (tcp_rsk(req)->snt_synack) - tcp_valid_rtt_meas(sk, - tcp_time_stamp - tcp_rsk(req)->snt_synack); + __tcp_adjust_rcv_ssthresh(sk, 4U * tcp_sk(sk)->advmss); } -extern void tcp_enter_memory_pressure(struct sock *sk); +void tcp_cleanup_rbuf(struct sock *sk, int copied); +void __tcp_cleanup_rbuf(struct sock *sk, int copied); + + +/* We provision sk_rcvbuf around 200% of sk_rcvlowat. + * If 87.5 % (7/8) of the space has been consumed, we want to override + * SO_RCVLOWAT constraint, since we are receiving skbs with too small + * len/truesize ratio. + */ +static inline bool tcp_rmem_pressure(const struct sock *sk) +{ + int rcvbuf, threshold; + + if (tcp_under_memory_pressure(sk)) + return true; + + rcvbuf = READ_ONCE(sk->sk_rcvbuf); + threshold = rcvbuf - (rcvbuf >> 3); + + return atomic_read(&sk->sk_rmem_alloc) > threshold; +} + +static inline bool tcp_epollin_ready(const struct sock *sk, int target) +{ + const struct tcp_sock *tp = tcp_sk(sk); + int avail = READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->copied_seq); + + if (avail <= 0) + return false; + + return (avail >= target) || tcp_rmem_pressure(sk) || + (tcp_receive_window(tp) <= inet_csk(sk)->icsk_ack.rcv_mss); +} + +extern void tcp_openreq_init_rwin(struct request_sock *req, + const struct sock *sk_listener, + const struct dst_entry *dst); + +void tcp_enter_memory_pressure(struct sock *sk); +void tcp_leave_memory_pressure(struct sock *sk); static inline int keepalive_intvl_when(const struct tcp_sock *tp) { - return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl; + struct net *net = sock_net((struct sock *)tp); + int val; + + /* Paired with WRITE_ONCE() in tcp_sock_set_keepintvl() + * and do_tcp_setsockopt(). + */ + val = READ_ONCE(tp->keepalive_intvl); + + return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_intvl); } static inline int keepalive_time_when(const struct tcp_sock *tp) { - return tp->keepalive_time ? : sysctl_tcp_keepalive_time; + struct net *net = sock_net((struct sock *)tp); + int val; + + /* Paired with WRITE_ONCE() in tcp_sock_set_keepidle_locked() */ + val = READ_ONCE(tp->keepalive_time); + + return val ? : READ_ONCE(net->ipv4.sysctl_tcp_keepalive_time); } static inline int keepalive_probes(const struct tcp_sock *tp) { - return tp->keepalive_probes ? : sysctl_tcp_keepalive_probes; + struct net *net = sock_net((struct sock *)tp); + int val; + + /* Paired with WRITE_ONCE() in tcp_sock_set_keepcnt() + * and do_tcp_setsockopt(). + */ + val = READ_ONCE(tp->keepalive_probes); + + return val ? : READ_ONCE(net->ipv4.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); + return min_t(u32, tcp_jiffies32 - icsk->icsk_ack.lrcvtime, + tcp_jiffies32 - tp->rcv_tstamp); } static inline int tcp_fin_time(const struct sock *sk) { - int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout; + int fin_timeout = tcp_sk(sk)->linger2 ? : + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_fin_timeout); const int rto = inet_csk(sk)->icsk_rto; if (fin_timeout < (rto << 2) - (rto >> 1)) @@ -1144,7 +1783,8 @@ static inline bool tcp_paws_check(const struct tcp_options_received *rx_opt, { if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) return true; - if (unlikely(get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)) + if (unlikely(!time_before32(ktime_get_seconds(), + rx_opt->ts_recent_stamp + TCP_PAWS_WRAP))) return true; /* * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0, @@ -1174,48 +1814,75 @@ static inline bool tcp_paws_reject(const struct tcp_options_received *rx_opt, However, we can relax time bounds for RST segments to MSL. */ - if (rst && get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL) + if (rst && !time_before32(ktime_get_seconds(), + rx_opt->ts_recent_stamp + TCP_PAWS_MSL)) return false; return true; } -static inline void tcp_mib_init(struct net *net) +static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) { - /* 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); + u32 ace; + + /* mptcp hooks are only on the slow path */ + if (sk_is_mptcp((struct sock *)tp)) + return; + + ace = tcp_ecn_mode_accecn(tp) ? + ((tp->delivered_ce + TCP_ACCECN_CEP_INIT_OFFSET) & + TCP_ACCECN_CEP_ACE_MASK) : 0; + + tp->pred_flags = htonl((tp->tcp_header_len << 26) | + (ace << 22) | + ntohl(TCP_FLAG_ACK) | + snd_wnd); } -/* from STCP */ -static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp) +static inline void tcp_fast_path_on(struct tcp_sock *tp) { - tp->lost_skb_hint = NULL; + __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 (RB_EMPTY_ROOT(&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); +} + +bool tcp_oow_rate_limited(struct net *net, const struct sk_buff *skb, + int mib_idx, u32 *last_oow_ack_time); + +static inline void tcp_mib_init(struct net *net) +{ + /* See RFC 2012 */ + TCP_ADD_STATS(net, TCP_MIB_RTOALGORITHM, 1); + TCP_ADD_STATS(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); + TCP_ADD_STATS(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); + TCP_ADD_STATS(net, TCP_MIB_MAXCONN, -1); +} + +/* from STCP */ 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 -}; +#define tcp_md5_addr tcp_ao_addr /* - key database */ struct tcp_md5sig_key { struct hlist_node node; u8 keylen; u8 family; /* AF_INET or AF_INET6 */ + u8 prefixlen; + u8 flags; union tcp_md5_addr addr; + int l3index; /* set if key added with L3 scope */ u8 key[TCP_MD5SIG_MAXKEYLEN]; struct rcu_head rcu; }; @@ -1242,133 +1909,235 @@ struct tcp6_pseudohdr { __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; +/* + * struct tcp_sigpool - per-CPU pool of ahash_requests + * @scratch: per-CPU temporary area, that can be used between + * tcp_sigpool_start() and tcp_sigpool_end() to perform + * crypto request + * @req: pre-allocated ahash request + */ +struct tcp_sigpool { + void *scratch; + struct ahash_request *req; }; +int tcp_sigpool_alloc_ahash(const char *alg, size_t scratch_size); +void tcp_sigpool_get(unsigned int id); +void tcp_sigpool_release(unsigned int id); +int tcp_sigpool_hash_skb_data(struct tcp_sigpool *hp, + const struct sk_buff *skb, + unsigned int header_len); + +/** + * tcp_sigpool_start - disable bh and start using tcp_sigpool_ahash + * @id: tcp_sigpool that was previously allocated by tcp_sigpool_alloc_ahash() + * @c: returned tcp_sigpool for usage (uninitialized on failure) + * + * Returns: 0 on success, error otherwise. + */ +int tcp_sigpool_start(unsigned int id, struct tcp_sigpool *c); +/** + * tcp_sigpool_end - enable bh and stop using tcp_sigpool + * @c: tcp_sigpool context that was returned by tcp_sigpool_start() + */ +void tcp_sigpool_end(struct tcp_sigpool *c); +size_t tcp_sigpool_algo(unsigned int id, char *buf, size_t buf_len); /* - 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); +void tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, + const struct sock *sk, const struct sk_buff *skb); +int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, + int family, u8 prefixlen, int l3index, u8 flags, + const u8 *newkey, u8 newkeylen); +int tcp_md5_key_copy(struct sock *sk, const union tcp_md5_addr *addr, + int family, u8 prefixlen, int l3index, + struct tcp_md5sig_key *key); + +int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, + int family, u8 prefixlen, int l3index, u8 flags); +void tcp_clear_md5_list(struct sock *sk); +struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, + const 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); +struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, + const union tcp_md5_addr *addr, + int family, bool any_l3index); +static inline struct tcp_md5sig_key * +tcp_md5_do_lookup(const struct sock *sk, int l3index, + const union tcp_md5_addr *addr, int family) +{ + if (!static_branch_unlikely(&tcp_md5_needed.key)) + return NULL; + return __tcp_md5_do_lookup(sk, l3index, addr, family, false); +} + +static inline struct tcp_md5sig_key * +tcp_md5_do_lookup_any_l3index(const struct sock *sk, + const union tcp_md5_addr *addr, int family) +{ + if (!static_branch_unlikely(&tcp_md5_needed.key)) + return NULL; + return __tcp_md5_do_lookup(sk, 0, addr, family, true); +} + #define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) +void tcp_md5_destruct_sock(struct sock *sk); #else -static inline struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk, - const union tcp_md5_addr *addr, - int family) +static inline struct tcp_md5sig_key * +tcp_md5_do_lookup(const struct sock *sk, int l3index, + const union tcp_md5_addr *addr, int family) { return NULL; } -#define tcp_twsk_md5_key(twsk) NULL -#endif -extern bool tcp_alloc_md5sig_pool(void); +static inline struct tcp_md5sig_key * +tcp_md5_do_lookup_any_l3index(const struct sock *sk, + const union tcp_md5_addr *addr, int family) +{ + return NULL; +} -extern struct tcp_md5sig_pool *tcp_get_md5sig_pool(void); -static inline void tcp_put_md5sig_pool(void) +#define tcp_twsk_md5_key(twsk) NULL +static inline void tcp_md5_destruct_sock(struct sock *sk) { - local_bh_enable(); } +#endif -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 int header_len); -extern int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, - const struct tcp_md5sig_key *key); +struct md5_ctx; +void tcp_md5_hash_skb_data(struct md5_ctx *ctx, const struct sk_buff *skb, + unsigned int header_len); +void tcp_md5_hash_key(struct md5_ctx *ctx, const struct tcp_md5sig_key *key); /* From tcp_fastopen.c */ -extern void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, - struct tcp_fastopen_cookie *cookie, - int *syn_loss, unsigned long *last_syn_loss); -extern void tcp_fastopen_cache_set(struct sock *sk, u16 mss, - struct tcp_fastopen_cookie *cookie, - bool syn_lost); +void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, + struct tcp_fastopen_cookie *cookie); +void tcp_fastopen_cache_set(struct sock *sk, u16 mss, + struct tcp_fastopen_cookie *cookie, bool syn_lost, + u16 try_exp); struct tcp_fastopen_request { /* Fast Open cookie. Size 0 means a cookie request */ struct tcp_fastopen_cookie cookie; struct msghdr *data; /* data in MSG_FASTOPEN */ - u16 copied; /* queued in tcp_connect() */ + size_t size; + int copied; /* queued in tcp_connect() */ + struct ubuf_info *uarg; }; void tcp_free_fastopen_req(struct tcp_sock *tp); - -extern struct tcp_fastopen_context __rcu *tcp_fastopen_ctx; -int tcp_fastopen_reset_cipher(void *key, unsigned int len); -void tcp_fastopen_cookie_gen(__be32 addr, struct tcp_fastopen_cookie *foc); - -#define TCP_FASTOPEN_KEY_LENGTH 16 +void tcp_fastopen_destroy_cipher(struct sock *sk); +void tcp_fastopen_ctx_destroy(struct net *net); +int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, + void *primary_key, void *backup_key); +int tcp_fastopen_get_cipher(struct net *net, struct inet_connection_sock *icsk, + u64 *key); +void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb); +struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct tcp_fastopen_cookie *foc, + const struct dst_entry *dst); +void tcp_fastopen_init_key_once(struct net *net); +bool tcp_fastopen_cookie_check(struct sock *sk, u16 *mss, + struct tcp_fastopen_cookie *cookie); +bool tcp_fastopen_defer_connect(struct sock *sk, int *err); +#define TCP_FASTOPEN_KEY_LENGTH sizeof(siphash_key_t) +#define TCP_FASTOPEN_KEY_MAX 2 +#define TCP_FASTOPEN_KEY_BUF_LENGTH \ + (TCP_FASTOPEN_KEY_LENGTH * TCP_FASTOPEN_KEY_MAX) /* Fastopen key context */ struct tcp_fastopen_context { - struct crypto_cipher *tfm; - __u8 key[TCP_FASTOPEN_KEY_LENGTH]; - struct rcu_head rcu; + siphash_key_t key[TCP_FASTOPEN_KEY_MAX]; + int num; + struct rcu_head rcu; }; -/* write queue abstraction */ -static inline void tcp_write_queue_purge(struct sock *sk) +void tcp_fastopen_active_disable(struct sock *sk); +bool tcp_fastopen_active_should_disable(struct sock *sk); +void tcp_fastopen_active_disable_ofo_check(struct sock *sk); +void tcp_fastopen_active_detect_blackhole(struct sock *sk, bool expired); + +/* Caller needs to wrap with rcu_read_(un)lock() */ +static inline +struct tcp_fastopen_context *tcp_fastopen_get_ctx(const struct sock *sk) { - struct sk_buff *skb; + struct tcp_fastopen_context *ctx; - 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)); + ctx = rcu_dereference(inet_csk(sk)->icsk_accept_queue.fastopenq.ctx); + if (!ctx) + ctx = rcu_dereference(sock_net(sk)->ipv4.tcp_fastopen_ctx); + return ctx; } -static inline struct sk_buff *tcp_write_queue_head(const struct sock *sk) +static inline +bool tcp_fastopen_cookie_match(const struct tcp_fastopen_cookie *foc, + const struct tcp_fastopen_cookie *orig) { - return skb_peek(&sk->sk_write_queue); + if (orig->len == TCP_FASTOPEN_COOKIE_SIZE && + orig->len == foc->len && + !memcmp(orig->val, foc->val, foc->len)) + return true; + return false; } -static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk) +static inline +int tcp_fastopen_context_len(const struct tcp_fastopen_context *ctx) { - return skb_peek_tail(&sk->sk_write_queue); + return ctx->num; } -static inline struct sk_buff *tcp_write_queue_next(const struct sock *sk, - const struct sk_buff *skb) +/* Latencies incurred by various limits for a sender. They are + * chronograph-like stats that are mutually exclusive. + */ +enum tcp_chrono { + TCP_CHRONO_UNSPEC, + TCP_CHRONO_BUSY, /* Actively sending data (non-empty write queue) */ + TCP_CHRONO_RWND_LIMITED, /* Stalled by insufficient receive window */ + TCP_CHRONO_SNDBUF_LIMITED, /* Stalled by insufficient send buffer */ + __TCP_CHRONO_MAX, +}; + +void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type); +void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type); + +/* This helper is needed, because skb->tcp_tsorted_anchor uses + * the same memory storage than skb->destructor/_skb_refdst + */ +static inline void tcp_skb_tsorted_anchor_cleanup(struct sk_buff *skb) { - return skb_queue_next(&sk->sk_write_queue, skb); + skb->destructor = NULL; + skb->_skb_refdst = 0UL; +} + +#define tcp_skb_tsorted_save(skb) { \ + unsigned long _save = skb->_skb_refdst; \ + skb->_skb_refdst = 0UL; + +#define tcp_skb_tsorted_restore(skb) \ + skb->_skb_refdst = _save; \ } -static inline struct sk_buff *tcp_write_queue_prev(const struct sock *sk, - const struct sk_buff *skb) +void tcp_write_queue_purge(struct sock *sk); + +static inline struct sk_buff *tcp_rtx_queue_head(const struct sock *sk) { - return skb_queue_prev(&sk->sk_write_queue, skb); + return skb_rb_first(&sk->tcp_rtx_queue); } -#define tcp_for_write_queue(skb, sk) \ - skb_queue_walk(&(sk)->sk_write_queue, skb) +static inline struct sk_buff *tcp_rtx_queue_tail(const struct sock *sk) +{ + return skb_rb_last(&sk->tcp_rtx_queue); +} -#define tcp_for_write_queue_from(skb, sk) \ - skb_queue_walk_from(&(sk)->sk_write_queue, skb) +static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk) +{ + return skb_peek_tail(&sk->sk_write_queue); +} #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; + return skb_peek(&sk->sk_write_queue); } static inline bool tcp_skb_is_last(const struct sock *sk, @@ -1377,54 +2146,37 @@ static inline bool tcp_skb_is_last(const struct sock *sk, 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) +/** + * tcp_write_queue_empty - test if any payload (or FIN) is available in write queue + * @sk: socket + * + * Since the write queue can have a temporary empty skb in it, + * we must not use "return skb_queue_empty(&sk->sk_write_queue)" + */ +static inline bool tcp_write_queue_empty(const struct sock *sk) { - if (tcp_skb_is_last(sk, skb)) - sk->sk_send_head = NULL; - else - sk->sk_send_head = tcp_write_queue_next(sk, skb); -} + const struct tcp_sock *tp = tcp_sk(sk); -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; + return tp->write_seq == tp->snd_nxt; } -static inline void tcp_init_send_head(struct sock *sk) +static inline bool tcp_rtx_queue_empty(const struct sock *sk) { - sk->sk_send_head = NULL; + return RB_EMPTY_ROOT(&sk->tcp_rtx_queue); } -static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) +static inline bool tcp_rtx_and_write_queues_empty(const struct sock *sk) { - __skb_queue_tail(&sk->sk_write_queue, skb); + return tcp_rtx_queue_empty(sk) && tcp_write_queue_empty(sk); } static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) { - __tcp_add_write_queue_tail(sk, skb); + __skb_queue_tail(&sk->sk_write_queue, 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); + if (sk->sk_write_queue.next == skb) + tcp_chrono_start(sk, TCP_CHRONO_BUSY); } /* Insert new before skb on the write queue of sk. */ @@ -1433,19 +2185,35 @@ static inline void tcp_insert_write_queue_before(struct sk_buff *new, 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) { + tcp_skb_tsorted_anchor_cleanup(skb); __skb_unlink(skb, &sk->sk_write_queue); } -static inline bool tcp_write_queue_empty(struct sock *sk) +void tcp_rbtree_insert(struct rb_root *root, struct sk_buff *skb); + +static inline void tcp_rtx_queue_unlink(struct sk_buff *skb, struct sock *sk) { - return skb_queue_empty(&sk->sk_write_queue); + tcp_skb_tsorted_anchor_cleanup(skb); + rb_erase(&skb->rbnode, &sk->tcp_rtx_queue); +} + +static inline void tcp_rtx_queue_unlink_and_free(struct sk_buff *skb, struct sock *sk) +{ + list_del(&skb->tcp_tsorted_anchor); + tcp_rtx_queue_unlink(skb, sk); + tcp_wmem_free_skb(sk, skb); +} + +static inline void tcp_write_collapse_fence(struct sock *sk) +{ + struct sk_buff *skb = tcp_write_queue_tail(sk); + + if (skb) + TCP_SKB_CB(skb)->eor = 1; } static inline void tcp_push_pending_frames(struct sock *sk) @@ -1474,8 +2242,7 @@ static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp) 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); + tcp_sk(sk)->highest_sack = skb_rb_next(skb); } static inline struct sk_buff *tcp_highest_sack(struct sock *sk) @@ -1485,18 +2252,30 @@ static inline struct sk_buff *tcp_highest_sack(struct sock *sk) static inline void tcp_highest_sack_reset(struct sock *sk) { - tcp_sk(sk)->highest_sack = tcp_write_queue_head(sk); + tcp_sk(sk)->highest_sack = tcp_rtx_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, +/* Called when old skb is about to be deleted and replaced by new skb */ +static inline void tcp_highest_sack_replace(struct sock *sk, struct sk_buff *old, struct sk_buff *new) { - if (tcp_sk(sk)->sacked_out && (old == tcp_sk(sk)->highest_sack)) + if (old == tcp_highest_sack(sk)) tcp_sk(sk)->highest_sack = new; } +/* This helper checks if socket has IP_TRANSPARENT set */ +static inline bool inet_sk_transparent(const struct sock *sk) +{ + switch (sk->sk_state) { + case TCP_TIME_WAIT: + return inet_twsk(sk)->tw_transparent; + case TCP_NEW_SYN_RECV: + return inet_rsk(inet_reqsk(sk))->no_srccheck; + } + return inet_test_bit(TRANSPARENT, sk); +} + /* Determines whether this is a thin stream (which may suffer from * increased latency). Used to trigger latency-reducing mechanisms. */ @@ -1508,83 +2287,659 @@ static inline bool tcp_stream_is_thin(struct tcp_sock *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); +void *tcp_seq_start(struct seq_file *seq, loff_t *pos); +void *tcp_seq_next(struct seq_file *seq, void *v, loff_t *pos); +void tcp_seq_stop(struct seq_file *seq, void *v); 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; - kuid_t 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); +void tcp_v4_destroy_sock(struct sock *sk); + +struct sk_buff *tcp_gso_segment(struct sk_buff *skb, + netdev_features_t features); +struct sk_buff *tcp_gro_lookup(struct list_head *head, struct tcphdr *th); +struct sk_buff *tcp_gro_receive(struct list_head *head, struct sk_buff *skb, + struct tcphdr *th); +INDIRECT_CALLABLE_DECLARE(int tcp4_gro_complete(struct sk_buff *skb, int thoff)); +INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp4_gro_receive(struct list_head *head, struct sk_buff *skb)); +INDIRECT_CALLABLE_DECLARE(int tcp6_gro_complete(struct sk_buff *skb, int thoff)); +INDIRECT_CALLABLE_DECLARE(struct sk_buff *tcp6_gro_receive(struct list_head *head, struct sk_buff *skb)); +#ifdef CONFIG_INET +void tcp_gro_complete(struct sk_buff *skb); +#else +static inline void tcp_gro_complete(struct sk_buff *skb) { } +#endif + +void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr); + +static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp) +{ + struct net *net = sock_net((struct sock *)tp); + u32 val; + + val = READ_ONCE(tp->notsent_lowat); -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 int tcp_gro_complete(struct sk_buff *skb); + return val ?: READ_ONCE(net->ipv4.sysctl_tcp_notsent_lowat); +} -extern void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, - __be32 daddr); +bool tcp_stream_memory_free(const struct sock *sk, int wake); #ifdef CONFIG_PROC_FS -extern int tcp4_proc_init(void); -extern void tcp4_proc_exit(void); +int tcp4_proc_init(void); +void tcp4_proc_exit(void); #endif +int tcp_rtx_synack(const struct sock *sk, struct request_sock *req); +int tcp_conn_request(struct request_sock_ops *rsk_ops, + const struct tcp_request_sock_ops *af_ops, + struct sock *sk, struct sk_buff *skb); + /* 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); + struct tcp_md5sig_key *(*md5_lookup) (const struct sock *sk, + const struct sock *addr_sk); + void (*calc_md5_hash)(char *location, + const struct tcp_md5sig_key *md5, + const struct sock *sk, + const struct sk_buff *skb); + int (*md5_parse)(struct sock *sk, + int optname, + sockptr_t optval, + int optlen); +#endif +#ifdef CONFIG_TCP_AO + int (*ao_parse)(struct sock *sk, int optname, sockptr_t optval, int optlen); + struct tcp_ao_key *(*ao_lookup)(const struct sock *sk, + struct sock *addr_sk, + int sndid, int rcvid); + int (*ao_calc_key_sk)(struct tcp_ao_key *mkt, u8 *key, + const struct sock *sk, + __be32 sisn, __be32 disn, bool send); + int (*calc_ao_hash)(char *location, struct tcp_ao_key *ao, + const struct sock *sk, const struct sk_buff *skb, + const u8 *tkey, int hash_offset, u32 sne); #endif }; struct tcp_request_sock_ops { + u16 mss_clamp; +#ifdef CONFIG_TCP_MD5SIG + struct tcp_md5sig_key *(*req_md5_lookup)(const struct sock *sk, + const struct sock *addr_sk); + void (*calc_md5_hash) (char *location, + const struct tcp_md5sig_key *md5, + const struct sock *sk, + const struct sk_buff *skb); +#endif +#ifdef CONFIG_TCP_AO + struct tcp_ao_key *(*ao_lookup)(const struct sock *sk, + struct request_sock *req, + int sndid, int rcvid); + int (*ao_calc_key)(struct tcp_ao_key *mkt, u8 *key, struct request_sock *sk); + int (*ao_synack_hash)(char *ao_hash, struct tcp_ao_key *mkt, + struct request_sock *req, const struct sk_buff *skb, + int hash_offset, u32 sne); +#endif +#ifdef CONFIG_SYN_COOKIES + __u32 (*cookie_init_seq)(const struct sk_buff *skb, + __u16 *mss); +#endif + struct dst_entry *(*route_req)(const struct sock *sk, + struct sk_buff *skb, + struct flowi *fl, + struct request_sock *req, + u32 tw_isn); + u32 (*init_seq)(const struct sk_buff *skb); + u32 (*init_ts_off)(const struct net *net, const struct sk_buff *skb); + int (*send_synack)(const struct sock *sk, struct dst_entry *dst, + struct flowi *fl, struct request_sock *req, + struct tcp_fastopen_cookie *foc, + enum tcp_synack_type synack_type, + struct sk_buff *syn_skb); +}; + +extern const struct tcp_request_sock_ops tcp_request_sock_ipv4_ops; +#if IS_ENABLED(CONFIG_IPV6) +extern const struct tcp_request_sock_ops tcp_request_sock_ipv6_ops; +#endif + +#ifdef CONFIG_SYN_COOKIES +static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, + const struct sock *sk, struct sk_buff *skb, + __u16 *mss) +{ + tcp_synq_overflow(sk); + __NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); + return ops->cookie_init_seq(skb, mss); +} +#else +static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, + const struct sock *sk, struct sk_buff *skb, + __u16 *mss) +{ + return 0; +} +#endif + +struct tcp_key { + union { + struct { + struct tcp_ao_key *ao_key; + char *traffic_key; + u32 sne; + u8 rcv_next; + }; + struct tcp_md5sig_key *md5_key; + }; + enum { + TCP_KEY_NONE = 0, + TCP_KEY_MD5, + TCP_KEY_AO, + } type; +}; + +static inline void tcp_get_current_key(const struct sock *sk, + struct tcp_key *out) +{ +#if defined(CONFIG_TCP_AO) || defined(CONFIG_TCP_MD5SIG) + const struct tcp_sock *tp = tcp_sk(sk); +#endif + +#ifdef CONFIG_TCP_AO + if (static_branch_unlikely(&tcp_ao_needed.key)) { + struct tcp_ao_info *ao; + + ao = rcu_dereference_protected(tp->ao_info, + lockdep_sock_is_held(sk)); + if (ao) { + out->ao_key = READ_ONCE(ao->current_key); + out->type = TCP_KEY_AO; + return; + } + } +#endif #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); + if (static_branch_unlikely(&tcp_md5_needed.key) && + rcu_access_pointer(tp->md5sig_info)) { + out->md5_key = tp->af_specific->md5_lookup(sk, sk); + if (out->md5_key) { + out->type = TCP_KEY_MD5; + return; + } + } #endif + out->type = TCP_KEY_NONE; +} + +static inline bool tcp_key_is_md5(const struct tcp_key *key) +{ + if (static_branch_tcp_md5()) + return key->type == TCP_KEY_MD5; + return false; +} + +static inline bool tcp_key_is_ao(const struct tcp_key *key) +{ + if (static_branch_tcp_ao()) + return key->type == TCP_KEY_AO; + return false; +} + +int tcpv4_offload_init(void); + +void tcp_v4_init(void); +void tcp_init(void); + +/* tcp_recovery.c */ +void tcp_mark_skb_lost(struct sock *sk, struct sk_buff *skb); +void tcp_newreno_mark_lost(struct sock *sk, bool snd_una_advanced); +extern s32 tcp_rack_skb_timeout(struct tcp_sock *tp, struct sk_buff *skb, + u32 reo_wnd); +extern bool tcp_rack_mark_lost(struct sock *sk); +extern void tcp_rack_advance(struct tcp_sock *tp, u8 sacked, u32 end_seq, + u64 xmit_time); +extern void tcp_rack_reo_timeout(struct sock *sk); +extern void tcp_rack_update_reo_wnd(struct sock *sk, struct rate_sample *rs); + +/* tcp_plb.c */ + +/* + * Scaling factor for fractions in PLB. For example, tcp_plb_update_state + * expects cong_ratio which represents fraction of traffic that experienced + * congestion over a single RTT. In order to avoid floating point operations, + * this fraction should be mapped to (1 << TCP_PLB_SCALE) and passed in. + */ +#define TCP_PLB_SCALE 8 + +/* State for PLB (Protective Load Balancing) for a single TCP connection. */ +struct tcp_plb_state { + u8 consec_cong_rounds:5, /* consecutive congested rounds */ + unused:3; + u32 pause_until; /* jiffies32 when PLB can resume rerouting */ +}; + +static inline void tcp_plb_init(const struct sock *sk, + struct tcp_plb_state *plb) +{ + plb->consec_cong_rounds = 0; + plb->pause_until = 0; +} +void tcp_plb_update_state(const struct sock *sk, struct tcp_plb_state *plb, + const int cong_ratio); +void tcp_plb_check_rehash(struct sock *sk, struct tcp_plb_state *plb); +void tcp_plb_update_state_upon_rto(struct sock *sk, struct tcp_plb_state *plb); + +static inline void tcp_warn_once(const struct sock *sk, bool cond, const char *str) +{ + WARN_ONCE(cond, + "%scwn:%u out:%u sacked:%u lost:%u retrans:%u tlp_high_seq:%u sk_state:%u ca_state:%u advmss:%u mss_cache:%u pmtu:%u\n", + str, + tcp_snd_cwnd(tcp_sk(sk)), + tcp_sk(sk)->packets_out, tcp_sk(sk)->sacked_out, + tcp_sk(sk)->lost_out, tcp_sk(sk)->retrans_out, + tcp_sk(sk)->tlp_high_seq, sk->sk_state, + inet_csk(sk)->icsk_ca_state, + tcp_sk(sk)->advmss, tcp_sk(sk)->mss_cache, + inet_csk(sk)->icsk_pmtu_cookie); +} + +/* At how many usecs into the future should the RTO fire? */ +static inline s64 tcp_rto_delta_us(const struct sock *sk) +{ + const struct sk_buff *skb = tcp_rtx_queue_head(sk); + u32 rto = inet_csk(sk)->icsk_rto; + + if (likely(skb)) { + u64 rto_time_stamp_us = tcp_skb_timestamp_us(skb) + jiffies_to_usecs(rto); + + return rto_time_stamp_us - tcp_sk(sk)->tcp_mstamp; + } else { + tcp_warn_once(sk, 1, "rtx queue empty: "); + return jiffies_to_usecs(rto); + } + +} + +/* + * Save and compile IPv4 options, return a pointer to it + */ +static inline struct ip_options_rcu *tcp_v4_save_options(struct net *net, + struct sk_buff *skb) +{ + const struct ip_options *opt = &TCP_SKB_CB(skb)->header.h4.opt; + struct ip_options_rcu *dopt = NULL; + + if (opt->optlen) { + int opt_size = sizeof(*dopt) + opt->optlen; + + dopt = kmalloc(opt_size, GFP_ATOMIC); + if (dopt && __ip_options_echo(net, &dopt->opt, skb, opt)) { + kfree(dopt); + dopt = NULL; + } + } + return dopt; +} + +/* locally generated TCP pure ACKs have skb->truesize == 2 + * (check tcp_send_ack() in net/ipv4/tcp_output.c ) + * This is much faster than dissecting the packet to find out. + * (Think of GRE encapsulations, IPv4, IPv6, ...) + */ +static inline bool skb_is_tcp_pure_ack(const struct sk_buff *skb) +{ + return skb->truesize == 2; +} + +static inline void skb_set_tcp_pure_ack(struct sk_buff *skb) +{ + skb->truesize = 2; +} + +static inline int tcp_inq(struct sock *sk) +{ + struct tcp_sock *tp = tcp_sk(sk); + int answ; + + if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { + answ = 0; + } else if (sock_flag(sk, SOCK_URGINLINE) || + !tp->urg_data || + before(tp->urg_seq, tp->copied_seq) || + !before(tp->urg_seq, tp->rcv_nxt)) { + + answ = tp->rcv_nxt - tp->copied_seq; + + /* Subtract 1, if FIN was received */ + if (answ && sock_flag(sk, SOCK_DONE)) + answ--; + } else { + answ = tp->urg_seq - tp->copied_seq; + } + + return answ; +} + +int tcp_peek_len(struct socket *sock); + +static inline void tcp_segs_in(struct tcp_sock *tp, const struct sk_buff *skb) +{ + u16 segs_in; + + segs_in = max_t(u16, 1, skb_shinfo(skb)->gso_segs); + + /* We update these fields while other threads might + * read them from tcp_get_info() + */ + WRITE_ONCE(tp->segs_in, tp->segs_in + segs_in); + if (skb->len > tcp_hdrlen(skb)) + WRITE_ONCE(tp->data_segs_in, tp->data_segs_in + segs_in); +} + +/* + * TCP listen path runs lockless. + * We forced "struct sock" to be const qualified to make sure + * we don't modify one of its field by mistake. + * Here, we increment sk_drops which is an atomic_t, so we can safely + * make sock writable again. + */ +static inline void tcp_listendrop(const struct sock *sk) +{ + sk_drops_inc((struct sock *)sk); + __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); +} + +enum hrtimer_restart tcp_pace_kick(struct hrtimer *timer); + +/* + * Interface for adding Upper Level Protocols over TCP + */ + +#define TCP_ULP_NAME_MAX 16 +#define TCP_ULP_MAX 128 +#define TCP_ULP_BUF_MAX (TCP_ULP_NAME_MAX*TCP_ULP_MAX) + +struct tcp_ulp_ops { + struct list_head list; + + /* initialize ulp */ + int (*init)(struct sock *sk); + /* update ulp */ + void (*update)(struct sock *sk, struct proto *p, + void (*write_space)(struct sock *sk)); + /* cleanup ulp */ + void (*release)(struct sock *sk); + /* diagnostic */ + int (*get_info)(struct sock *sk, struct sk_buff *skb, bool net_admin); + size_t (*get_info_size)(const struct sock *sk, bool net_admin); + /* clone ulp */ + void (*clone)(const struct request_sock *req, struct sock *newsk, + const gfp_t priority); + + char name[TCP_ULP_NAME_MAX]; + struct module *owner; }; +int tcp_register_ulp(struct tcp_ulp_ops *type); +void tcp_unregister_ulp(struct tcp_ulp_ops *type); +int tcp_set_ulp(struct sock *sk, const char *name); +void tcp_get_available_ulp(char *buf, size_t len); +void tcp_cleanup_ulp(struct sock *sk); +void tcp_update_ulp(struct sock *sk, struct proto *p, + void (*write_space)(struct sock *sk)); + +#define MODULE_ALIAS_TCP_ULP(name) \ + MODULE_INFO(alias, name); \ + MODULE_INFO(alias, "tcp-ulp-" name) + +#ifdef CONFIG_NET_SOCK_MSG +struct sk_msg; +struct sk_psock; + +#ifdef CONFIG_BPF_SYSCALL +int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore); +void tcp_bpf_clone(const struct sock *sk, struct sock *newsk); +#ifdef CONFIG_BPF_STREAM_PARSER +struct strparser; +int tcp_bpf_strp_read_sock(struct strparser *strp, read_descriptor_t *desc, + sk_read_actor_t recv_actor); +#endif /* CONFIG_BPF_STREAM_PARSER */ +#endif /* CONFIG_BPF_SYSCALL */ + +#ifdef CONFIG_INET +void tcp_eat_skb(struct sock *sk, struct sk_buff *skb); +#else +static inline void tcp_eat_skb(struct sock *sk, struct sk_buff *skb) +{ +} +#endif -extern int tcpv4_offload_init(void); +int tcp_bpf_sendmsg_redir(struct sock *sk, bool ingress, + struct sk_msg *msg, u32 bytes, int flags); +#endif /* CONFIG_NET_SOCK_MSG */ + +#if !defined(CONFIG_BPF_SYSCALL) || !defined(CONFIG_NET_SOCK_MSG) +static inline void tcp_bpf_clone(const struct sock *sk, struct sock *newsk) +{ +} +#endif + +#ifdef CONFIG_CGROUP_BPF +static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops, + struct sk_buff *skb, + unsigned int end_offset) +{ + skops->skb = skb; + skops->skb_data_end = skb->data + end_offset; +} +#else +static inline void bpf_skops_init_skb(struct bpf_sock_ops_kern *skops, + struct sk_buff *skb, + unsigned int end_offset) +{ +} +#endif + +/* Call BPF_SOCK_OPS program that returns an int. If the return value + * is < 0, then the BPF op failed (for example if the loaded BPF + * program does not support the chosen operation or there is no BPF + * program loaded). + */ +#ifdef CONFIG_BPF +static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) +{ + struct bpf_sock_ops_kern sock_ops; + int ret; + + memset(&sock_ops, 0, offsetof(struct bpf_sock_ops_kern, temp)); + if (sk_fullsock(sk)) { + sock_ops.is_fullsock = 1; + sock_ops.is_locked_tcp_sock = 1; + sock_owned_by_me(sk); + } + + sock_ops.sk = sk; + sock_ops.op = op; + if (nargs > 0) + memcpy(sock_ops.args, args, nargs * sizeof(*args)); + + ret = BPF_CGROUP_RUN_PROG_SOCK_OPS(&sock_ops); + if (ret == 0) + ret = sock_ops.reply; + else + ret = -1; + return ret; +} + +static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) +{ + u32 args[2] = {arg1, arg2}; + + return tcp_call_bpf(sk, op, 2, args); +} + +static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, + u32 arg3) +{ + u32 args[3] = {arg1, arg2, arg3}; + + return tcp_call_bpf(sk, op, 3, args); +} + +#else +static inline int tcp_call_bpf(struct sock *sk, int op, u32 nargs, u32 *args) +{ + return -EPERM; +} + +static inline int tcp_call_bpf_2arg(struct sock *sk, int op, u32 arg1, u32 arg2) +{ + return -EPERM; +} + +static inline int tcp_call_bpf_3arg(struct sock *sk, int op, u32 arg1, u32 arg2, + u32 arg3) +{ + return -EPERM; +} + +#endif + +static inline u32 tcp_timeout_init(struct sock *sk) +{ + int timeout; + + timeout = tcp_call_bpf(sk, BPF_SOCK_OPS_TIMEOUT_INIT, 0, NULL); + + if (timeout <= 0) + timeout = TCP_TIMEOUT_INIT; + return min_t(int, timeout, TCP_RTO_MAX); +} + +static inline u32 tcp_rwnd_init_bpf(struct sock *sk) +{ + int rwnd; + + rwnd = tcp_call_bpf(sk, BPF_SOCK_OPS_RWND_INIT, 0, NULL); + + if (rwnd < 0) + rwnd = 0; + return rwnd; +} + +static inline bool tcp_bpf_ca_needs_ecn(struct sock *sk) +{ + return (tcp_call_bpf(sk, BPF_SOCK_OPS_NEEDS_ECN, 0, NULL) == 1); +} + +static inline void tcp_bpf_rtt(struct sock *sk, long mrtt, u32 srtt) +{ + if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_RTT_CB_FLAG)) + tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_RTT_CB, mrtt, srtt); +} + +#if IS_ENABLED(CONFIG_SMC) +extern struct static_key_false tcp_have_smc; +#endif + +#if IS_ENABLED(CONFIG_TLS_DEVICE) +void clean_acked_data_enable(struct tcp_sock *tp, + void (*cad)(struct sock *sk, u32 ack_seq)); +void clean_acked_data_disable(struct tcp_sock *tp); +void clean_acked_data_flush(void); +#endif + +DECLARE_STATIC_KEY_FALSE(tcp_tx_delay_enabled); +static inline void tcp_add_tx_delay(struct sk_buff *skb, + const struct tcp_sock *tp) +{ + if (static_branch_unlikely(&tcp_tx_delay_enabled)) + skb->skb_mstamp_ns += (u64)tp->tcp_tx_delay * NSEC_PER_USEC; +} + +/* Compute Earliest Departure Time for some control packets + * like ACK or RST for TIME_WAIT or non ESTABLISHED sockets. + */ +static inline u64 tcp_transmit_time(const struct sock *sk) +{ + if (static_branch_unlikely(&tcp_tx_delay_enabled)) { + u32 delay = (sk->sk_state == TCP_TIME_WAIT) ? + tcp_twsk(sk)->tw_tx_delay : tcp_sk(sk)->tcp_tx_delay; + + return tcp_clock_ns() + (u64)delay * NSEC_PER_USEC; + } + return 0; +} + +static inline int tcp_parse_auth_options(const struct tcphdr *th, + const u8 **md5_hash, const struct tcp_ao_hdr **aoh) +{ + const u8 *md5_tmp, *ao_tmp; + int ret; + + ret = tcp_do_parse_auth_options(th, &md5_tmp, &ao_tmp); + if (ret) + return ret; + + if (md5_hash) + *md5_hash = md5_tmp; + + if (aoh) { + if (!ao_tmp) + *aoh = NULL; + else + *aoh = (struct tcp_ao_hdr *)(ao_tmp - 2); + } + + return 0; +} + +static inline bool tcp_ao_required(struct sock *sk, const void *saddr, + int family, int l3index, bool stat_inc) +{ +#ifdef CONFIG_TCP_AO + struct tcp_ao_info *ao_info; + struct tcp_ao_key *ao_key; + + if (!static_branch_unlikely(&tcp_ao_needed.key)) + return false; + + ao_info = rcu_dereference_check(tcp_sk(sk)->ao_info, + lockdep_sock_is_held(sk)); + if (!ao_info) + return false; + + ao_key = tcp_ao_do_lookup(sk, l3index, saddr, family, -1, -1); + if (ao_info->ao_required || ao_key) { + if (stat_inc) { + NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOREQUIRED); + atomic64_inc(&ao_info->counters.ao_required); + } + return true; + } +#endif + return false; +} -extern void tcp_v4_init(void); -extern void tcp_init(void); +enum skb_drop_reason tcp_inbound_hash(struct sock *sk, + const struct request_sock *req, const struct sk_buff *skb, + const void *saddr, const void *daddr, + int family, int dif, int sdif); #endif /* _TCP_H */ |