diff options
Diffstat (limited to 'include/net/tcp.h')
| -rw-r--r-- | include/net/tcp.h | 1108 |
1 files changed, 590 insertions, 518 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index 34f5cc24d90..7286db80e8b 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -18,11 +18,11 @@ #ifndef _TCP_H #define _TCP_H -#define TCP_DEBUG 1 #define FASTRETRANS_DEBUG 1 #include <linux/list.h> #include <linux/tcp.h> +#include <linux/bug.h> #include <linux/slab.h> #include <linux/cache.h> #include <linux/percpu.h> @@ -31,6 +31,7 @@ #include <linux/crypto.h> #include <linux/cryptohash.h> #include <linux/kref.h> +#include <linux/ktime.h> #include <net/inet_connection_sock.h> #include <net/inet_timewait_sock.h> @@ -45,11 +46,12 @@ #include <net/dst.h> #include <linux/seq_file.h> +#include <linux/memcontrol.h> extern struct inet_hashinfo tcp_hashinfo; extern struct percpu_counter tcp_orphan_count; -extern void tcp_time_wait(struct sock *sk, int state, int timeo); +void tcp_time_wait(struct sock *sk, int state, int timeo); #define MAX_TCP_HEADER (128 + MAX_HEADER) #define MAX_TCP_OPTION_SPACE 40 @@ -94,17 +96,21 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); * 15 is ~13-30min depending on RTO. */ -#define TCP_SYN_RETRIES 5 /* number of times to retry active opening a - * connection: ~180sec is RFC minimum */ - -#define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a - * connection: ~180sec is RFC minimum */ - - -#define TCP_ORPHAN_RETRIES 7 /* number of times to retry on an orphaned - * socket. 7 is ~50sec-16min. +#define TCP_SYN_RETRIES 6 /* This is how many retries are done + * when active opening a connection. + * RFC1122 says the minimum retry MUST + * be at least 180secs. Nevertheless + * this value is corresponding to + * 63secs of retransmission with the + * current initial RTO. */ +#define TCP_SYNACK_RETRIES 5 /* This is how may retries are done + * when passive opening a connection. + * This is corresponding to 31secs of + * retransmission with the current + * initial RTO. + */ #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT * state, about 60 seconds */ @@ -125,7 +131,13 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); #endif #define TCP_RTO_MAX ((unsigned)(120*HZ)) #define TCP_RTO_MIN ((unsigned)(HZ/5)) -#define TCP_TIMEOUT_INIT ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value */ +#define TCP_TIMEOUT_INIT ((unsigned)(1*HZ)) /* RFC6298 2.1 initial RTO value */ +#define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now + * used as a fallback RTO for the + * initial data transmission if no + * valid RTT sample has been acquired, + * most likely due to retrans in 3WHS. + */ #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes * for local resources. @@ -165,7 +177,11 @@ 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_COOKIE 253 /* Cookie extension (experimental) */ +#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 /* * TCP option lengths @@ -176,10 +192,7 @@ 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_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_FASTOPEN_BASE 4 /* But this is what stacks really send out. */ #define TCPOLEN_TSTAMP_ALIGNED 12 @@ -196,6 +209,26 @@ extern void tcp_time_wait(struct sock *sk, int state, int timeo); #define TCP_NAGLE_CORK 2 /* Socket is corked */ #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */ +/* TCP thin-stream limits */ +#define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */ + +/* TCP initial congestion window as per draft-hkchu-tcpm-initcwnd-01 */ +#define TCP_INIT_CWND 10 + +/* Bit Flags for sysctl_tcp_fastopen */ +#define TFO_CLIENT_ENABLE 1 +#define TFO_SERVER_ENABLE 2 +#define TFO_CLIENT_NO_COOKIE 4 /* Data in SYN w/o cookie option */ + +/* 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. + */ +#define TFO_SERVER_WO_SOCKOPT1 0x400 +#define TFO_SERVER_WO_SOCKOPT2 0x800 + extern struct inet_timewait_death_row tcp_death_row; /* sysctl variables for tcp */ @@ -212,6 +245,7 @@ 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; @@ -219,30 +253,33 @@ extern int sysctl_tcp_abort_on_overflow; extern int sysctl_tcp_max_orphans; extern int sysctl_tcp_fack; extern int sysctl_tcp_reordering; -extern int sysctl_tcp_ecn; extern int sysctl_tcp_dsack; -extern int sysctl_tcp_mem[3]; +extern long sysctl_tcp_mem[3]; extern int sysctl_tcp_wmem[3]; extern int sysctl_tcp_rmem[3]; extern int sysctl_tcp_app_win; extern int sysctl_tcp_adv_win_scale; extern int sysctl_tcp_tw_reuse; extern int sysctl_tcp_frto; -extern int sysctl_tcp_frto_response; extern int sysctl_tcp_low_latency; extern int sysctl_tcp_dma_copybreak; extern int sysctl_tcp_nometrics_save; extern int sysctl_tcp_moderate_rcvbuf; extern int sysctl_tcp_tso_win_divisor; -extern int sysctl_tcp_abc; extern int sysctl_tcp_mtu_probing; extern int sysctl_tcp_base_mss; extern int sysctl_tcp_workaround_signed_windows; extern int sysctl_tcp_slow_start_after_idle; -extern int sysctl_tcp_max_ssthresh; -extern int sysctl_tcp_cookie_size; - -extern atomic_t tcp_memory_allocated; +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 unsigned int sysctl_tcp_notsent_lowat; +extern int sysctl_tcp_min_tso_segs; +extern int sysctl_tcp_autocorking; + +extern atomic_long_t tcp_memory_allocated; extern struct percpu_counter tcp_sockets_allocated; extern int tcp_memory_pressure; @@ -251,25 +288,41 @@ extern int tcp_memory_pressure; * and worry about wraparound (automatic with unsigned arithmetic). */ -static inline int before(__u32 seq1, __u32 seq2) +static inline bool before(__u32 seq1, __u32 seq2) { return (__s32)(seq1-seq2) < 0; } #define after(seq2, seq1) before(seq1, seq2) /* is s2<=s1<=s3 ? */ -static inline int between(__u32 seq1, __u32 seq2, __u32 seq3) +static inline bool between(__u32 seq1, __u32 seq2, __u32 seq3) { return seq3 - seq2 >= seq1 - seq2; } -static inline int tcp_too_many_orphans(struct sock *sk, int num) +static inline bool tcp_out_of_memory(struct sock *sk) { - return (num > sysctl_tcp_max_orphans) || - (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && - atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2]); + if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && + sk_memory_allocated(sk) > sk_prot_mem_limits(sk, 2)) + return true; + return false; } +static inline bool tcp_too_many_orphans(struct sock *sk, int shift) +{ + struct percpu_counter *ocp = sk->sk_prot->orphan_count; + int orphans = percpu_counter_read_positive(ocp); + + if (orphans << shift > sysctl_tcp_max_orphans) { + orphans = percpu_counter_sum_positive(ocp); + if (orphans << shift > sysctl_tcp_max_orphans) + return true; + } + return false; +} + +bool tcp_check_oom(struct sock *sk, int shift); + /* syncookies: remember time of last synqueue overflow */ static inline void tcp_synq_overflow(struct sock *sk) { @@ -277,10 +330,10 @@ static inline void tcp_synq_overflow(struct sock *sk) } /* syncookies: no recent synqueue overflow on this listening socket? */ -static inline int tcp_synq_no_recent_overflow(const struct sock *sk) +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_INIT); + return time_after(jiffies, last_overflow + TCP_TIMEOUT_FALLBACK); } extern struct proto tcp_prot; @@ -289,46 +342,38 @@ extern struct proto tcp_prot; #define TCP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.tcp_statistics, field) #define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field) #define TCP_ADD_STATS_USER(net, field, val) SNMP_ADD_STATS_USER((net)->mib.tcp_statistics, field, val) - -extern void tcp_v4_err(struct sk_buff *skb, u32); - -extern void tcp_shutdown (struct sock *sk, int how); - -extern int tcp_v4_rcv(struct sk_buff *skb); - -extern int tcp_v4_remember_stamp(struct sock *sk); - -extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw); - -extern int tcp_sendmsg(struct kiocb *iocb, struct socket *sock, - struct msghdr *msg, size_t size); -extern ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags); - -extern int tcp_ioctl(struct sock *sk, - int cmd, - unsigned long arg); - -extern int tcp_rcv_state_process(struct sock *sk, - struct sk_buff *skb, - struct tcphdr *th, - unsigned len); - -extern int tcp_rcv_established(struct sock *sk, - struct sk_buff *skb, - struct tcphdr *th, - unsigned len); - -extern void tcp_rcv_space_adjust(struct sock *sk); - -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); +#define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val) + +void tcp_tasklet_init(void); + +void tcp_v4_err(struct sk_buff *skb, u32); + +void tcp_shutdown(struct sock *sk, int how); + +void tcp_v4_early_demux(struct sk_buff *skb); +int tcp_v4_rcv(struct sk_buff *skb); + +int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw); +int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, + size_t size); +int tcp_sendpage(struct sock *sk, struct page *page, int offset, size_t size, + int flags); +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, unsigned long arg); +int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb, + const struct tcphdr *th, unsigned int len); +void tcp_rcv_established(struct sock *sk, struct sk_buff *skb, + const struct tcphdr *th, unsigned int len); +void tcp_rcv_space_adjust(struct sock *sk); +void tcp_cleanup_rbuf(struct sock *sk, int copied); +int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); +void tcp_twsk_destructor(struct sock *sk); +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) @@ -345,18 +390,10 @@ static inline void tcp_dec_quickack_mode(struct sock *sk, } } -extern void tcp_enter_quickack_mode(struct sock *sk); - #define TCP_ECN_OK 1 #define TCP_ECN_QUEUE_CWR 2 #define TCP_ECN_DEMAND_CWR 4 - -static __inline__ void -TCP_ECN_create_request(struct request_sock *req, struct tcphdr *th) -{ - if (sysctl_tcp_ecn && th->ece && th->cwr) - inet_rsk(req)->ecn_ok = 1; -} +#define TCP_ECN_SEEN 8 enum tcp_tw_status { TCP_TW_SUCCESS = 0, @@ -366,161 +403,207 @@ enum tcp_tw_status { }; -extern enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, - struct sk_buff *skb, - const struct tcphdr *th); - -extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb, - struct request_sock *req, - struct request_sock **prev); -extern int tcp_child_process(struct sock *parent, - struct sock *child, - struct sk_buff *skb); -extern int tcp_use_frto(struct sock *sk); -extern void tcp_enter_frto(struct sock *sk); -extern void tcp_enter_loss(struct sock *sk, int how); -extern void tcp_clear_retrans(struct tcp_sock *tp); -extern void tcp_update_metrics(struct sock *sk); - -extern void tcp_close(struct sock *sk, - long timeout); -extern unsigned int tcp_poll(struct file * file, struct socket *sock, struct poll_table_struct *wait); - -extern int tcp_getsockopt(struct sock *sk, int level, - int optname, - char __user *optval, - int __user *optlen); -extern int tcp_setsockopt(struct sock *sk, int level, - int optname, char __user *optval, - unsigned int optlen); -extern int compat_tcp_getsockopt(struct sock *sk, - int level, int optname, - char __user *optval, int __user *optlen); -extern int compat_tcp_setsockopt(struct sock *sk, - int level, int optname, - char __user *optval, unsigned int optlen); -extern void tcp_set_keepalive(struct sock *sk, int val); -extern 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(struct sk_buff *skb, - struct tcp_options_received *opt_rx, - u8 **hvpp, - int estab); - -extern u8 *tcp_parse_md5sig_option(struct tcphdr *th); +enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, + struct sk_buff *skb, + const struct tcphdr *th); +struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, struct request_sock **prev, + bool fastopen); +int tcp_child_process(struct sock *parent, struct sock *child, + struct sk_buff *skb); +void tcp_enter_loss(struct sock *sk, int how); +void tcp_clear_retrans(struct tcp_sock *tp); +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, + bool paws_check); +bool tcp_remember_stamp(struct sock *sk); +bool tcp_tw_remember_stamp(struct inet_timewait_sock *tw); +void tcp_fetch_timewait_stamp(struct sock *sk, struct dst_entry *dst); +void tcp_disable_fack(struct tcp_sock *tp); +void tcp_close(struct sock *sk, long timeout); +void tcp_init_sock(struct sock *sk); +unsigned int tcp_poll(struct file *file, struct socket *sock, + struct poll_table_struct *wait); +int tcp_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen); +int tcp_setsockopt(struct sock *sk, int level, int optname, + char __user *optval, unsigned int optlen); +int compat_tcp_getsockopt(struct sock *sk, int level, int optname, + char __user *optval, int __user *optlen); +int compat_tcp_setsockopt(struct sock *sk, int level, int optname, + char __user *optval, unsigned int optlen); +void tcp_set_keepalive(struct sock *sk, int val); +void tcp_syn_ack_timeout(struct sock *sk, struct request_sock *req); +int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, + size_t len, int nonblock, int flags, int *addr_len); +void tcp_parse_options(const struct sk_buff *skb, + struct tcp_options_received *opt_rx, + int estab, struct tcp_fastopen_cookie *foc); +const u8 *tcp_parse_md5sig_option(const struct tcphdr *th); /* * TCP v4 functions exported for the inet6 API */ -extern void tcp_v4_send_check(struct sock *sk, int len, - struct sk_buff *skb); - -extern int tcp_v4_conn_request(struct sock *sk, - struct sk_buff *skb); - -extern struct sock * tcp_create_openreq_child(struct sock *sk, - struct request_sock *req, - struct sk_buff *skb); - -extern struct sock * tcp_v4_syn_recv_sock(struct sock *sk, - struct sk_buff *skb, - struct request_sock *req, - struct dst_entry *dst); - -extern int tcp_v4_do_rcv(struct sock *sk, - struct sk_buff *skb); - -extern int tcp_v4_connect(struct sock *sk, - struct sockaddr *uaddr, - int addr_len); +void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); +int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); +struct sock *tcp_create_openreq_child(struct sock *sk, + struct request_sock *req, + struct sk_buff *skb); +struct sock *tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct dst_entry *dst); +int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); +int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); +int tcp_connect(struct sock *sk); +struct sk_buff *tcp_make_synack(struct sock *sk, struct dst_entry *dst, + struct request_sock *req, + struct tcp_fastopen_cookie *foc); +int tcp_disconnect(struct sock *sk, int flags); + +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); -extern int tcp_connect(struct sock *sk); - -extern struct sk_buff * tcp_make_synack(struct sock *sk, - struct dst_entry *dst, - struct request_sock *req, - struct request_values *rvp); +/* From syncookies.c */ +int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th, + u32 cookie); +struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb, + struct ip_options *opt); +#ifdef CONFIG_SYN_COOKIES + +/* 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 -extern int tcp_disconnect(struct sock *sk, int flags); +static inline u32 tcp_cookie_time(void) +{ + u64 val = get_jiffies_64(); + do_div(val, 60 * HZ); + return val; +} -/* 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); -extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, - __u16 *mss); +u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, + u16 *mssp); +__u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, __u16 *mss); +#else +static inline __u32 cookie_v4_init_sequence(struct sock *sk, + struct sk_buff *skb, + __u16 *mss) +{ + return 0; +} +#endif -extern __u32 cookie_init_timestamp(struct request_sock *req); -extern void cookie_check_timestamp(struct tcp_options_received *tcp_opt); +__u32 cookie_init_timestamp(struct request_sock *req); +bool cookie_check_timestamp(struct tcp_options_received *opt, struct net *net, + bool *ecn_ok); /* From net/ipv6/syncookies.c */ -extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); -extern __u32 cookie_v6_init_sequence(struct sock *sk, struct sk_buff *skb, - __u16 *mss); - +int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th, + u32 cookie); +struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); +#ifdef CONFIG_SYN_COOKIES +u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, + const struct tcphdr *th, u16 *mssp); +__u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb, + __u16 *mss); +#else +static inline __u32 cookie_v6_init_sequence(struct sock *sk, + struct sk_buff *skb, + __u16 *mss) +{ + return 0; +} +#endif /* tcp_output.c */ -extern void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, - int nonagle); -extern int tcp_may_send_now(struct sock *sk); -extern int tcp_retransmit_skb(struct sock *, struct sk_buff *); -extern void tcp_retransmit_timer(struct sock *sk); -extern void tcp_xmit_retransmit_queue(struct sock *); -extern void tcp_simple_retransmit(struct sock *); -extern int tcp_trim_head(struct sock *, struct sk_buff *, u32); -extern int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int); - -extern void tcp_send_probe0(struct sock *); -extern void tcp_send_partial(struct sock *); -extern int tcp_write_wakeup(struct sock *); -extern void tcp_send_fin(struct sock *sk); -extern void tcp_send_active_reset(struct sock *sk, gfp_t priority); -extern int tcp_send_synack(struct sock *); -extern 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); +void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, + int nonagle); +bool tcp_may_send_now(struct sock *sk); +int __tcp_retransmit_skb(struct sock *, struct sk_buff *); +int tcp_retransmit_skb(struct sock *, struct sk_buff *); +void tcp_retransmit_timer(struct sock *sk); +void tcp_xmit_retransmit_queue(struct sock *); +void tcp_simple_retransmit(struct sock *); +int tcp_trim_head(struct sock *, struct sk_buff *, u32); +int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int, gfp_t); + +void tcp_send_probe0(struct sock *); +void tcp_send_partial(struct sock *); +int tcp_write_wakeup(struct sock *); +void tcp_send_fin(struct sock *sk); +void tcp_send_active_reset(struct sock *sk, gfp_t priority); +int tcp_send_synack(struct sock *); +bool tcp_syn_flood_action(struct sock *sk, const struct sk_buff *skb, + const char *proto); +void tcp_push_one(struct sock *, unsigned int mss_now); +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); /* tcp_input.c */ -extern void tcp_cwnd_application_limited(struct sock *sk); +void tcp_resume_early_retransmit(struct sock *sk); +void tcp_rearm_rto(struct sock *sk); +void tcp_reset(struct sock *sk); /* 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) { 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); /* 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) { - if (tp->max_window && pktsize > (tp->max_window >> 1)) - return max(tp->max_window >> 1, 68U - tp->tcp_header_len); + int cutoff; + + /* When peer uses tiny windows, there is no use in packetizing + * to sub-MSS pieces for the sake of SWS or making sure there + * are enough packets in the pipe for fast recovery. + * + * On the other hand, for extremely large MSS devices, handling + * smaller than MSS windows in this way does make sense. + */ + if (tp->max_window >= 512) + cutoff = (tp->max_window >> 1); + else + cutoff = tp->max_window; + + if (cutoff && pktsize > cutoff) + return max_t(int, cutoff, 68U - tp->tcp_header_len); else return pktsize; } /* tcp.c */ -extern void tcp_get_info(struct sock *, struct tcp_info *); +void tcp_get_info(const struct sock *, struct tcp_info *); /* Read 'sendfile()'-style from a TCP socket */ typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *, unsigned int, size_t); -extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, - sk_read_actor_t recv_actor); +int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, + sk_read_actor_t recv_actor); -extern void tcp_initialize_rcv_mss(struct sock *sk); +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); +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); +void tcp_init_buffer_space(struct sock *sk); static inline void tcp_bound_rto(const struct sock *sk) { @@ -530,7 +613,7 @@ static inline void tcp_bound_rto(const struct sock *sk) static inline u32 __tcp_set_rto(const struct tcp_sock *tp) { - return (tp->srtt >> 3) + tp->rttvar; + return usecs_to_jiffies((tp->srtt_us >> 3) + tp->rttvar_us); } static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) @@ -559,7 +642,7 @@ static inline void tcp_fast_path_check(struct sock *sk) /* Compute the actual rto_min value */ static inline u32 tcp_rto_min(struct sock *sk) { - struct dst_entry *dst = __sk_dst_get(sk); + const struct dst_entry *dst = __sk_dst_get(sk); u32 rto_min = TCP_RTO_MIN; if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) @@ -567,6 +650,11 @@ static inline u32 tcp_rto_min(struct sock *sk) return rto_min; } +static inline u32 tcp_rto_min_us(struct sock *sk) +{ + return jiffies_to_usecs(tcp_rto_min(sk)); +} + /* 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. @@ -584,7 +672,9 @@ 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 @@ -594,51 +684,67 @@ extern u32 __tcp_select_window(struct sock *sk); */ #define tcp_time_stamp ((__u32)(jiffies)) +#define tcp_flag_byte(th) (((u_int8_t *)th)[13]) + +#define TCPHDR_FIN 0x01 +#define TCPHDR_SYN 0x02 +#define TCPHDR_RST 0x04 +#define TCPHDR_PSH 0x08 +#define TCPHDR_ACK 0x10 +#define TCPHDR_URG 0x20 +#define TCPHDR_ECE 0x40 +#define TCPHDR_CWR 0x80 + /* This is what the send packet queuing engine uses to pass - * TCP per-packet control information to the transmission - * code. We also store the host-order sequence numbers in - * here too. This is 36 bytes on 32-bit architectures, - * 40 bytes on 64-bit machines, if this grows please adjust - * skbuff.h:skbuff->cb[xxx] size appropriately. + * TCP per-packet control information to the transmission code. + * We also store the host-order sequence numbers in here too. + * This is 44 bytes if IPV6 is enabled. + * If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately. */ struct tcp_skb_cb { union { struct inet_skb_parm h4; -#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) +#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 flags; /* TCP header flags. */ - - /* NOTE: These must match up to the flags byte in a - * real TCP header. - */ -#define TCPCB_FLAG_FIN 0x01 -#define TCPCB_FLAG_SYN 0x02 -#define TCPCB_FLAG_RST 0x04 -#define TCPCB_FLAG_PSH 0x08 -#define TCPCB_FLAG_ACK 0x10 -#define TCPCB_FLAG_URG 0x20 -#define TCPCB_FLAG_ECE 0x40 -#define TCPCB_FLAG_CWR 0x80 + __u8 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) + __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ + /* 1 byte hole */ __u32 ack_seq; /* Sequence number ACK'd */ }; #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. + */ +static inline void +TCP_ECN_create_request(struct request_sock *req, const struct sk_buff *skb, + struct net *net) +{ + const struct tcphdr *th = tcp_hdr(skb); + + 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; +} + /* Due to TSO, an SKB can be composed of multiple actual * packets. To keep these tracked properly, we use this. */ @@ -658,7 +764,6 @@ enum tcp_ca_event { CA_EVENT_TX_START, /* first transmit when no packets in flight */ CA_EVENT_CWND_RESTART, /* congestion window restart */ CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ - CA_EVENT_FRTO, /* fast recovery timeout */ CA_EVENT_LOSS, /* loss timeout */ CA_EVENT_FAST_ACK, /* in sequence ack */ CA_EVENT_SLOW_ACK, /* other ack */ @@ -672,7 +777,6 @@ enum tcp_ca_event { #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) #define TCP_CONG_NON_RESTRICTED 0x1 -#define TCP_CONG_RTT_STAMP 0x2 struct tcp_congestion_ops { struct list_head list; @@ -685,10 +789,8 @@ struct tcp_congestion_ops { /* 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) */ @@ -704,24 +806,23 @@ struct tcp_congestion_ops { struct module *owner; }; -extern int tcp_register_congestion_control(struct tcp_congestion_ops *type); -extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); +int tcp_register_congestion_control(struct tcp_congestion_ops *type); +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); +void tcp_init_congestion_control(struct sock *sk); +void tcp_cleanup_congestion_control(struct sock *sk); +int tcp_set_default_congestion_control(const char *name); +void tcp_get_default_congestion_control(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); +int tcp_slow_start(struct tcp_sock *tp, u32 acked); +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); +u32 tcp_reno_ssthresh(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) @@ -754,19 +855,34 @@ static inline int tcp_is_sack(const struct tcp_sock *tp) return tp->rx_opt.sack_ok; } -static inline int tcp_is_reno(const struct tcp_sock *tp) +static inline bool tcp_is_reno(const struct tcp_sock *tp) { return !tcp_is_sack(tp); } -static inline int tcp_is_fack(const struct tcp_sock *tp) +static inline bool tcp_is_fack(const struct tcp_sock *tp) { - return tp->rx_opt.sack_ok & 2; + return tp->rx_opt.sack_ok & TCP_FACK_ENABLED; } static inline void tcp_enable_fack(struct tcp_sock *tp) { - tp->rx_opt.sack_ok |= 2; + 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) @@ -800,14 +916,21 @@ static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; } +static inline bool tcp_in_cwnd_reduction(const struct sock *sk) +{ + return (TCPF_CA_CWR | TCPF_CA_Recovery) & + (1 << inet_csk(sk)->icsk_ca_state); +} + /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. - * The exception is rate halving phase, when cwnd is decreasing towards + * The exception is cwnd reduction phase, when cwnd is decreasing towards * ssthresh. */ static inline __u32 tcp_current_ssthresh(const struct sock *sk) { const struct tcp_sock *tp = tcp_sk(sk); - if ((1 << inet_csk(sk)->icsk_ca_state) & (TCPF_CA_CWR | TCPF_CA_Recovery)) + + if (tcp_in_cwnd_reduction(sk)) return tp->snd_ssthresh; else return max(tp->snd_ssthresh, @@ -818,8 +941,16 @@ static inline __u32 tcp_current_ssthresh(const struct sock *sk) /* 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(struct tcp_sock *tp, struct dst_entry *dst); +void tcp_enter_cwr(struct sock *sk, const int set_ssthresh); +__u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst); + +/* The maximum number of MSS of available cwnd for which TSO defers + * sending if not using sysctl_tcp_tso_win_divisor. + */ +static inline __u32 tcp_max_tso_deferred_mss(const struct tcp_sock *tp) +{ + return 3; +} /* Slow start with delack produces 3 packets of burst, so that * it is safe "de facto". This will be the default - same as @@ -837,18 +968,34 @@ static inline u32 tcp_wnd_end(const struct tcp_sock *tp) { return tp->snd_una + tp->snd_wnd; } -extern int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight); -static inline void tcp_minshall_update(struct tcp_sock *tp, unsigned int mss, - const struct sk_buff *skb) +/* 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 bool tcp_is_cwnd_limited(const struct sock *sk) { - if (skb->len < mss) - tp->snd_sml = TCP_SKB_CB(skb)->end_seq; + const struct tcp_sock *tp = tcp_sk(sk); + + /* If in slow start, ensure cwnd grows to twice what was ACKed. */ + if (tp->snd_cwnd <= tp->snd_ssthresh) + return tp->snd_cwnd < 2 * tp->max_packets_out; + + return tp->is_cwnd_limited; } static inline void tcp_check_probe_timer(struct sock *sk) { - struct tcp_sock *tp = tcp_sk(sk); + const struct tcp_sock *tp = tcp_sk(sk); const struct inet_connection_sock *icsk = inet_csk(sk); if (!tp->packets_out && !icsk->icsk_pending) @@ -856,13 +1003,6 @@ static inline void tcp_check_probe_timer(struct sock *sk) icsk->icsk_rto, TCP_RTO_MAX); } -static inline void tcp_push_pending_frames(struct sock *sk) -{ - struct tcp_sock *tp = tcp_sk(sk); - - __tcp_push_pending_frames(sk, tcp_current_mss(sk), tp->nonagle); -} - static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) { tp->snd_wl1 = seq; @@ -887,7 +1027,7 @@ static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb) return __skb_checksum_complete(skb); } -static inline int tcp_checksum_complete(struct sk_buff *skb) +static inline bool tcp_checksum_complete(struct sk_buff *skb) { return !skb_csum_unnecessary(skb) && __tcp_checksum_complete(skb); @@ -909,46 +1049,7 @@ static inline void tcp_prequeue_init(struct tcp_sock *tp) #endif } -/* Packet is added to VJ-style prequeue for processing in process - * context, if a reader task is waiting. Apparently, this exciting - * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93) - * failed somewhere. Latency? Burstiness? Well, at least now we will - * see, why it failed. 8)8) --ANK - * - * NOTE: is this not too big to inline? - */ -static inline int tcp_prequeue(struct sock *sk, struct sk_buff *skb) -{ - struct tcp_sock *tp = tcp_sk(sk); - - if (sysctl_tcp_low_latency || !tp->ucopy.task) - return 0; - - __skb_queue_tail(&tp->ucopy.prequeue, skb); - tp->ucopy.memory += skb->truesize; - if (tp->ucopy.memory > sk->sk_rcvbuf) { - struct sk_buff *skb1; - - BUG_ON(sock_owned_by_user(sk)); - - while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) { - sk_backlog_rcv(sk, skb1); - NET_INC_STATS_BH(sock_net(sk), - LINUX_MIB_TCPPREQUEUEDROPPED); - } - - tp->ucopy.memory = 0; - } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) { - wake_up_interruptible_poll(sk->sk_sleep, - POLLIN | POLLRDNORM | POLLRDBAND); - if (!inet_csk_ack_scheduled(sk)) - inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, - (3 * tcp_rto_min(sk)) / 4, - TCP_RTO_MAX); - } - return 1; -} - +bool tcp_prequeue(struct sock *sk, struct sk_buff *skb); #undef STATE_TRACE @@ -959,9 +1060,9 @@ static const char *statename[]={ "Close Wait","Last ACK","Listen","Closing" }; #endif -extern void tcp_set_state(struct sock *sk, int state); +void tcp_set_state(struct sock *sk, int state); -extern void tcp_done(struct sock *sk); +void tcp_done(struct sock *sk); static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) { @@ -969,10 +1070,12 @@ static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) rx_opt->num_sacks = 0; } +u32 tcp_default_init_rwnd(u32 mss); + /* 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); +void tcp_select_initial_window(int __space, __u32 mss, __u32 *rcv_wnd, + __u32 *window_clamp, int wscale_ok, + __u8 *rcv_wscale, __u32 init_rcv_wnd); static inline int tcp_win_from_space(int space) { @@ -1002,6 +1105,8 @@ static inline void tcp_openreq_init(struct request_sock *req, req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */ req->cookie_ts = 0; tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq; + 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; @@ -1010,11 +1115,14 @@ static inline void tcp_openreq_init(struct request_sock *req, 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; + ireq->ir_rmt_port = tcp_hdr(skb)->source; + ireq->ir_num = ntohs(tcp_hdr(skb)->dest); } -extern void tcp_enter_memory_pressure(struct sock *sk); +extern void tcp_openreq_init_rwin(struct request_sock *req, + struct sock *sk, struct dst_entry *dst); + +void tcp_enter_memory_pressure(struct sock *sk); static inline int keepalive_intvl_when(const struct tcp_sock *tp) { @@ -1031,6 +1139,14 @@ static inline int keepalive_probes(const struct tcp_sock *tp) return tp->keepalive_probes ? : sysctl_tcp_keepalive_probes; } +static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) +{ + const struct inet_connection_sock *icsk = &tp->inet_conn; + + return min_t(u32, tcp_time_stamp - icsk->icsk_ack.lrcvtime, + tcp_time_stamp - tp->rcv_tstamp); +} + static inline int tcp_fin_time(const struct sock *sk) { int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout; @@ -1042,22 +1158,28 @@ static inline int tcp_fin_time(const struct sock *sk) return fin_timeout; } -static inline int tcp_paws_check(const struct tcp_options_received *rx_opt, - int paws_win) +static inline bool tcp_paws_check(const struct tcp_options_received *rx_opt, + int paws_win) { if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) - return 1; + return true; if (unlikely(get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)) - return 1; - - return 0; + return true; + /* + * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0, + * then following tcp messages have valid values. Ignore 0 value, + * or else 'negative' tsval might forbid us to accept their packets. + */ + if (!rx_opt->ts_recent) + return true; + return false; } -static inline int tcp_paws_reject(const struct tcp_options_received *rx_opt, - int rst) +static inline bool tcp_paws_reject(const struct tcp_options_received *rx_opt, + int rst) { if (tcp_paws_check(rx_opt, 0)) - return 0; + return false; /* RST segments are not recommended to carry timestamp, and, if they do, it is recommended to ignore PAWS because @@ -1072,12 +1194,10 @@ static inline int 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) - return 0; - return 1; + return false; + return true; } -#define TCP_CHECK_TIMER(sk) do { } while (0) - static inline void tcp_mib_init(struct net *net) { /* See RFC 2012 */ @@ -1091,7 +1211,6 @@ static inline void tcp_mib_init(struct net *net) static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp) { tp->lost_skb_hint = NULL; - tp->scoreboard_skb_hint = NULL; } static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) @@ -1103,35 +1222,27 @@ static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) /* MD5 Signature */ struct crypto_hash; +union tcp_md5_addr { + struct in_addr a4; +#if IS_ENABLED(CONFIG_IPV6) + struct in6_addr a6; +#endif +}; + /* - key database */ struct tcp_md5sig_key { - u8 *key; + struct hlist_node node; u8 keylen; -}; - -struct tcp4_md5sig_key { - struct tcp_md5sig_key base; - __be32 addr; -}; - -struct tcp6_md5sig_key { - struct tcp_md5sig_key base; -#if 0 - u32 scope_id; /* XXX */ -#endif - struct in6_addr addr; + u8 family; /* AF_INET or AF_INET6 */ + union tcp_md5_addr addr; + u8 key[TCP_MD5SIG_MAXKEYLEN]; + struct rcu_head rcu; }; /* - sock block */ struct tcp_md5sig_info { - struct tcp4_md5sig_key *keys4; -#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) - struct tcp6_md5sig_key *keys6; - u32 entries6; - u32 alloced6; -#endif - u32 entries4; - u32 alloced4; + struct hlist_head head; + struct rcu_head rcu; }; /* - pseudo header */ @@ -1152,7 +1263,7 @@ struct tcp6_pseudohdr { union tcp_md5sum_block { struct tcp4_pseudohdr ip4; -#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) +#if IS_ENABLED(CONFIG_IPV6) struct tcp6_pseudohdr ip6; #endif }; @@ -1163,62 +1274,76 @@ struct tcp_md5sig_pool { union tcp_md5sum_block md5_blk; }; -#define TCP_MD5SIG_MAXKEYS (~(u32)0) /* really?! */ - /* - functions */ -extern int tcp_v4_md5_hash_skb(char *md5_hash, - struct tcp_md5sig_key *key, - struct sock *sk, - struct request_sock *req, - struct sk_buff *skb); - -extern struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk, - struct sock *addr_sk); - -extern int tcp_v4_md5_do_add(struct sock *sk, - __be32 addr, - u8 *newkey, - u8 newkeylen); - -extern int tcp_v4_md5_do_del(struct sock *sk, - __be32 addr); +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); +int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, + int family, const u8 *newkey, u8 newkeylen, gfp_t gfp); +int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, + int family); +struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk, + struct sock *addr_sk); #ifdef CONFIG_TCP_MD5SIG -#define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_keylen ? \ - &(struct tcp_md5sig_key) { \ - .key = (twsk)->tw_md5_key, \ - .keylen = (twsk)->tw_md5_keylen, \ - } : NULL) +struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk, + const union tcp_md5_addr *addr, + int family); +#define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) #else +static inline struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk, + const union tcp_md5_addr *addr, + int family) +{ + return NULL; +} #define tcp_twsk_md5_key(twsk) NULL #endif -extern struct tcp_md5sig_pool **tcp_alloc_md5sig_pool(struct sock *); -extern void tcp_free_md5sig_pool(void); - -extern struct tcp_md5sig_pool *__tcp_get_md5sig_pool(int cpu); -extern void __tcp_put_md5sig_pool(void); -extern int tcp_md5_hash_header(struct tcp_md5sig_pool *, struct tcphdr *); -extern int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, struct sk_buff *, - unsigned header_len); -extern int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, - struct tcp_md5sig_key *key); +bool tcp_alloc_md5sig_pool(void); -static inline -struct tcp_md5sig_pool *tcp_get_md5sig_pool(void) +struct tcp_md5sig_pool *tcp_get_md5sig_pool(void); +static inline void tcp_put_md5sig_pool(void) { - int cpu = get_cpu(); - struct tcp_md5sig_pool *ret = __tcp_get_md5sig_pool(cpu); - if (!ret) - put_cpu(); - return ret; + local_bh_enable(); } -static inline void tcp_put_md5sig_pool(void) -{ - __tcp_put_md5sig_pool(); - put_cpu(); -} +int tcp_md5_hash_header(struct tcp_md5sig_pool *, const struct tcphdr *); +int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, const struct sk_buff *, + unsigned int header_len); +int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, + const struct tcp_md5sig_key *key); + +/* From tcp_fastopen.c */ +void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, + struct tcp_fastopen_cookie *cookie, int *syn_loss, + unsigned long *last_syn_loss); +void tcp_fastopen_cache_set(struct sock *sk, u16 mss, + struct tcp_fastopen_cookie *cookie, bool syn_lost); +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 */ + size_t size; + int copied; /* queued in tcp_connect() */ +}; +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); +bool tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, + struct request_sock *req, + struct tcp_fastopen_cookie *foc, + struct dst_entry *dst); +void tcp_fastopen_init_key_once(bool publish); +#define TCP_FASTOPEN_KEY_LENGTH 16 + +/* Fastopen key context */ +struct tcp_fastopen_context { + struct crypto_cipher *tfm; + __u8 key[TCP_FASTOPEN_KEY_LENGTH]; + struct rcu_head rcu; +}; /* write queue abstraction */ static inline void tcp_write_queue_purge(struct sock *sk) @@ -1231,22 +1356,24 @@ static inline void tcp_write_queue_purge(struct sock *sk) tcp_clear_all_retrans_hints(tcp_sk(sk)); } -static inline struct sk_buff *tcp_write_queue_head(struct sock *sk) +static inline struct sk_buff *tcp_write_queue_head(const struct sock *sk) { return skb_peek(&sk->sk_write_queue); } -static inline struct sk_buff *tcp_write_queue_tail(struct sock *sk) +static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk) { return skb_peek_tail(&sk->sk_write_queue); } -static inline struct sk_buff *tcp_write_queue_next(struct sock *sk, struct sk_buff *skb) +static inline struct sk_buff *tcp_write_queue_next(const struct sock *sk, + const struct sk_buff *skb) { return skb_queue_next(&sk->sk_write_queue, skb); } -static inline struct sk_buff *tcp_write_queue_prev(struct sock *sk, struct sk_buff *skb) +static inline struct sk_buff *tcp_write_queue_prev(const struct sock *sk, + const struct sk_buff *skb) { return skb_queue_prev(&sk->sk_write_queue, skb); } @@ -1260,7 +1387,7 @@ static inline struct sk_buff *tcp_write_queue_prev(struct sock *sk, struct sk_bu #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(struct sock *sk) +static inline struct sk_buff *tcp_send_head(const struct sock *sk) { return sk->sk_send_head; } @@ -1271,7 +1398,7 @@ 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, struct sk_buff *skb) +static inline void tcp_advance_send_head(struct sock *sk, const struct sk_buff *skb) { if (tcp_skb_is_last(sk, skb)) sk->sk_send_head = NULL; @@ -1337,13 +1464,23 @@ static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk) __skb_unlink(skb, &sk->sk_write_queue); } -static inline int tcp_write_queue_empty(struct sock *sk) +static inline bool tcp_write_queue_empty(struct sock *sk) { return skb_queue_empty(&sk->sk_write_queue); } -/* Start sequence of the highest skb with SACKed bit, valid only if - * sacked > 0 or when the caller has ensured validity by itself. +static inline void tcp_push_pending_frames(struct sock *sk) +{ + if (tcp_send_head(sk)) { + struct tcp_sock *tp = tcp_sk(sk); + + __tcp_push_pending_frames(sk, tcp_current_mss(sk), tp->nonagle); + } +} + +/* Start sequence of the skb just after the highest skb with SACKed + * bit, valid only if sacked_out > 0 or when the caller has ensured + * validity by itself. */ static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp) { @@ -1381,19 +1518,28 @@ static inline void tcp_highest_sack_combine(struct sock *sk, tcp_sk(sk)->highest_sack = new; } +/* Determines whether this is a thin stream (which may suffer from + * increased latency). Used to trigger latency-reducing mechanisms. + */ +static inline bool tcp_stream_is_thin(struct tcp_sock *tp) +{ + return tp->packets_out < 4 && !tcp_in_initial_slowstart(tp); +} + /* /proc */ enum tcp_seq_states { TCP_SEQ_STATE_LISTENING, TCP_SEQ_STATE_OPENREQ, TCP_SEQ_STATE_ESTABLISHED, - TCP_SEQ_STATE_TIME_WAIT, }; +int tcp_seq_open(struct inode *inode, struct file *file); + struct tcp_seq_afinfo { - char *name; - sa_family_t family; - struct file_operations seq_fops; - struct seq_operations seq_ops; + char *name; + sa_family_t family; + const struct file_operations *seq_fops; + struct seq_operations seq_ops; }; struct tcp_iter_state { @@ -1401,29 +1547,42 @@ struct tcp_iter_state { sa_family_t family; enum tcp_seq_states state; struct sock *syn_wait_sk; - int bucket, sbucket, num, uid; + 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); +int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo); +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_receive(struct sk_buff **head, struct sk_buff *skb); +int tcp_gro_complete(struct sk_buff *skb); + +void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr); + +static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp) +{ + return tp->notsent_lowat ?: sysctl_tcp_notsent_lowat; +} + +static inline bool tcp_stream_memory_free(const struct sock *sk) +{ + const struct tcp_sock *tp = tcp_sk(sk); + u32 notsent_bytes = tp->write_seq - tp->snd_nxt; -extern int tcp_v4_gso_send_check(struct sk_buff *skb); -extern struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features); -extern struct sk_buff **tcp_gro_receive(struct sk_buff **head, - struct sk_buff *skb); -extern struct sk_buff **tcp4_gro_receive(struct sk_buff **head, - struct sk_buff *skb); -extern int tcp_gro_complete(struct sk_buff *skb); -extern int tcp4_gro_complete(struct sk_buff *skb); + return notsent_bytes < tcp_notsent_lowat(tp); +} #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 /* TCP af-specific functions */ @@ -1433,13 +1592,9 @@ struct tcp_sock_af_ops { struct sock *addr_sk); int (*calc_md5_hash) (char *location, struct tcp_md5sig_key *md5, - struct sock *sk, - struct request_sock *req, - struct sk_buff *skb); - int (*md5_add) (struct sock *sk, - struct sock *addr_sk, - u8 *newkey, - u8 len); + 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); @@ -1452,98 +1607,15 @@ struct tcp_request_sock_ops { struct request_sock *req); int (*calc_md5_hash) (char *location, struct tcp_md5sig_key *md5, - struct sock *sk, - struct request_sock *req, - struct sk_buff *skb); + const struct sock *sk, + const struct request_sock *req, + const struct sk_buff *skb); #endif }; -/* Using SHA1 for now, define some constants. - */ -#define COOKIE_DIGEST_WORDS (SHA_DIGEST_WORDS) -#define COOKIE_MESSAGE_WORDS (SHA_MESSAGE_BYTES / 4) -#define COOKIE_WORKSPACE_WORDS (COOKIE_DIGEST_WORDS + COOKIE_MESSAGE_WORDS) - -extern int tcp_cookie_generator(u32 *bakery); - -/** - * struct tcp_cookie_values - each socket needs extra space for the - * cookies, together with (optional) space for any SYN data. - * - * A tcp_sock contains a pointer to the current value, and this is - * cloned to the tcp_timewait_sock. - * - * @cookie_pair: variable data from the option exchange. - * - * @cookie_desired: user specified tcpct_cookie_desired. Zero - * indicates default (sysctl_tcp_cookie_size). - * After cookie sent, remembers size of cookie. - * Range 0, TCP_COOKIE_MIN to TCP_COOKIE_MAX. - * - * @s_data_desired: user specified tcpct_s_data_desired. When the - * constant payload is specified (@s_data_constant), - * holds its length instead. - * Range 0 to TCP_MSS_DESIRED. - * - * @s_data_payload: constant data that is to be included in the - * payload of SYN or SYNACK segments when the - * cookie option is present. - */ -struct tcp_cookie_values { - struct kref kref; - u8 cookie_pair[TCP_COOKIE_PAIR_SIZE]; - u8 cookie_pair_size; - u8 cookie_desired; - u16 s_data_desired:11, - s_data_constant:1, - s_data_in:1, - s_data_out:1, - s_data_unused:2; - u8 s_data_payload[0]; -}; - -static inline void tcp_cookie_values_release(struct kref *kref) -{ - kfree(container_of(kref, struct tcp_cookie_values, kref)); -} - -/* The length of constant payload data. Note that s_data_desired is - * overloaded, depending on s_data_constant: either the length of constant - * data (returned here) or the limit on variable data. - */ -static inline int tcp_s_data_size(const struct tcp_sock *tp) -{ - return (tp->cookie_values != NULL && tp->cookie_values->s_data_constant) - ? tp->cookie_values->s_data_desired - : 0; -} - -/** - * struct tcp_extend_values - tcp_ipv?.c to tcp_output.c workspace. - * - * As tcp_request_sock has already been extended in other places, the - * only remaining method is to pass stack values along as function - * parameters. These parameters are not needed after sending SYNACK. - * - * @cookie_bakery: cryptographic secret and message workspace. - * - * @cookie_plus: bytes in authenticator/cookie option, copied from - * struct tcp_options_received (above). - */ -struct tcp_extend_values { - struct request_values rv; - u32 cookie_bakery[COOKIE_WORKSPACE_WORDS]; - u8 cookie_plus:6, - cookie_out_never:1, - cookie_in_always:1; -}; - -static inline struct tcp_extend_values *tcp_xv(struct request_values *rvp) -{ - return (struct tcp_extend_values *)rvp; -} +int tcpv4_offload_init(void); -extern void tcp_v4_init(void); -extern void tcp_init(void); +void tcp_v4_init(void); +void tcp_init(void); #endif /* _TCP_H */ |