Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * INET An implementation of the TCP/IP protocol suite for the LINUX |
| 3 | * operating system. INET is implemented using the BSD Socket |
| 4 | * interface as the means of communication with the user level. |
| 5 | * |
| 6 | * Definitions for the TCP module. |
| 7 | * |
| 8 | * Version: @(#)tcp.h 1.0.5 05/23/93 |
| 9 | * |
Jesper Juhl | 02c30a8 | 2005-05-05 16:16:16 -0700 | [diff] [blame] | 10 | * Authors: Ross Biro |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> |
| 12 | * |
| 13 | * This program is free software; you can redistribute it and/or |
| 14 | * modify it under the terms of the GNU General Public License |
| 15 | * as published by the Free Software Foundation; either version |
| 16 | * 2 of the License, or (at your option) any later version. |
| 17 | */ |
| 18 | #ifndef _TCP_H |
| 19 | #define _TCP_H |
| 20 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #define FASTRETRANS_DEBUG 1 |
| 22 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | #include <linux/list.h> |
| 24 | #include <linux/tcp.h> |
Paul Gortmaker | 187f188 | 2011-11-23 20:12:59 -0500 | [diff] [blame] | 25 | #include <linux/bug.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | #include <linux/slab.h> |
| 27 | #include <linux/cache.h> |
| 28 | #include <linux/percpu.h> |
Herbert Xu | fb286bb | 2005-11-10 13:01:24 -0800 | [diff] [blame] | 29 | #include <linux/skbuff.h> |
Glenn Griffin | c6aefaf | 2008-02-07 21:49:26 -0800 | [diff] [blame] | 30 | #include <linux/cryptohash.h> |
William Allen Simpson | 435cf55 | 2009-12-02 18:17:05 +0000 | [diff] [blame] | 31 | #include <linux/kref.h> |
Eric Dumazet | 740b0f1 | 2014-02-26 14:02:48 -0800 | [diff] [blame] | 32 | #include <linux/ktime.h> |
Arnaldo Carvalho de Melo | 3f421ba | 2005-08-09 20:11:08 -0700 | [diff] [blame] | 33 | |
| 34 | #include <net/inet_connection_sock.h> |
Arnaldo Carvalho de Melo | 295ff7e | 2005-08-09 20:44:40 -0700 | [diff] [blame] | 35 | #include <net/inet_timewait_sock.h> |
Arnaldo Carvalho de Melo | 77d8bf9 | 2005-08-09 20:00:51 -0700 | [diff] [blame] | 36 | #include <net/inet_hashtables.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | #include <net/checksum.h> |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 38 | #include <net/request_sock.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | #include <net/sock.h> |
| 40 | #include <net/snmp.h> |
| 41 | #include <net/ip.h> |
Arnaldo Carvalho de Melo | c752f07 | 2005-08-09 20:08:28 -0700 | [diff] [blame] | 42 | #include <net/tcp_states.h> |
Ilpo Järvinen | bdf1ee5 | 2007-05-27 02:04:16 -0700 | [diff] [blame] | 43 | #include <net/inet_ecn.h> |
Satoru SATOH | 0c26689 | 2009-05-04 11:11:01 -0700 | [diff] [blame] | 44 | #include <net/dst.h> |
Arnaldo Carvalho de Melo | c752f07 | 2005-08-09 20:08:28 -0700 | [diff] [blame] | 45 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | #include <linux/seq_file.h> |
Glauber Costa | 180d8cd | 2011-12-11 21:47:02 +0000 | [diff] [blame] | 47 | #include <linux/memcontrol.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | |
Arnaldo Carvalho de Melo | 6e04e02 | 2005-08-09 20:07:35 -0700 | [diff] [blame] | 49 | extern struct inet_hashinfo tcp_hashinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 50 | |
Eric Dumazet | dd24c00 | 2008-11-25 21:17:14 -0800 | [diff] [blame] | 51 | extern struct percpu_counter tcp_orphan_count; |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 52 | void tcp_time_wait(struct sock *sk, int state, int timeo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | #define MAX_TCP_HEADER (128 + MAX_HEADER) |
Adam Langley | 33ad798 | 2008-07-19 00:04:31 -0700 | [diff] [blame] | 55 | #define MAX_TCP_OPTION_SPACE 40 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | |
Kenjiro Nakayama | 105970f | 2014-10-20 18:15:50 +0900 | [diff] [blame] | 57 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 58 | * Never offer a window over 32767 without using window scaling. Some |
Kenjiro Nakayama | 105970f | 2014-10-20 18:15:50 +0900 | [diff] [blame] | 59 | * poor stacks do signed 16bit maths! |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | */ |
| 61 | #define MAX_TCP_WINDOW 32767U |
| 62 | |
| 63 | /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ |
| 64 | #define TCP_MIN_MSS 88U |
| 65 | |
John Heffner | 5d424d5 | 2006-03-20 17:53:41 -0800 | [diff] [blame] | 66 | /* The least MTU to use for probing */ |
Fan Du | dcd8fb8 | 2015-03-06 11:18:22 +0800 | [diff] [blame] | 67 | #define TCP_BASE_MSS 1024 |
John Heffner | 5d424d5 | 2006-03-20 17:53:41 -0800 | [diff] [blame] | 68 | |
Fan Du | 05cbc0d | 2015-03-06 11:18:24 +0800 | [diff] [blame] | 69 | /* probing interval, default to 10 minutes as per RFC4821 */ |
| 70 | #define TCP_PROBE_INTERVAL 600 |
| 71 | |
Fan Du | 6b58e0a | 2015-03-06 11:18:23 +0800 | [diff] [blame] | 72 | /* Specify interval when tcp mtu probing will stop */ |
| 73 | #define TCP_PROBE_THRESHOLD 8 |
| 74 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | /* After receiving this amount of duplicate ACKs fast retransmit starts. */ |
| 76 | #define TCP_FASTRETRANS_THRESH 3 |
| 77 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 78 | /* Maximal number of ACKs sent quickly to accelerate slow-start. */ |
| 79 | #define TCP_MAX_QUICKACKS 16U |
| 80 | |
| 81 | /* urg_data states */ |
| 82 | #define TCP_URG_VALID 0x0100 |
| 83 | #define TCP_URG_NOTYET 0x0200 |
| 84 | #define TCP_URG_READ 0x0400 |
| 85 | |
| 86 | #define TCP_RETR1 3 /* |
| 87 | * This is how many retries it does before it |
| 88 | * tries to figure out if the gateway is |
| 89 | * down. Minimal RFC value is 3; it corresponds |
| 90 | * to ~3sec-8min depending on RTO. |
| 91 | */ |
| 92 | |
| 93 | #define TCP_RETR2 15 /* |
| 94 | * This should take at least |
| 95 | * 90 minutes to time out. |
| 96 | * RFC1122 says that the limit is 100 sec. |
| 97 | * 15 is ~13-30min depending on RTO. |
| 98 | */ |
| 99 | |
Alex Bergmann | 6c9ff97 | 2012-08-31 02:48:31 +0000 | [diff] [blame] | 100 | #define TCP_SYN_RETRIES 6 /* This is how many retries are done |
| 101 | * when active opening a connection. |
| 102 | * RFC1122 says the minimum retry MUST |
| 103 | * be at least 180secs. Nevertheless |
| 104 | * this value is corresponding to |
| 105 | * 63secs of retransmission with the |
| 106 | * current initial RTO. |
| 107 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 108 | |
Alex Bergmann | 6c9ff97 | 2012-08-31 02:48:31 +0000 | [diff] [blame] | 109 | #define TCP_SYNACK_RETRIES 5 /* This is how may retries are done |
| 110 | * when passive opening a connection. |
| 111 | * This is corresponding to 31secs of |
| 112 | * retransmission with the current |
| 113 | * initial RTO. |
| 114 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 115 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT |
| 117 | * state, about 60 seconds */ |
| 118 | #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN |
| 119 | /* BSD style FIN_WAIT2 deadlock breaker. |
| 120 | * It used to be 3min, new value is 60sec, |
| 121 | * to combine FIN-WAIT-2 timeout with |
| 122 | * TIME-WAIT timer. |
| 123 | */ |
| 124 | |
| 125 | #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ |
| 126 | #if HZ >= 100 |
| 127 | #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */ |
| 128 | #define TCP_ATO_MIN ((unsigned)(HZ/25)) |
| 129 | #else |
| 130 | #define TCP_DELACK_MIN 4U |
| 131 | #define TCP_ATO_MIN 4U |
| 132 | #endif |
| 133 | #define TCP_RTO_MAX ((unsigned)(120*HZ)) |
| 134 | #define TCP_RTO_MIN ((unsigned)(HZ/5)) |
Eric Dumazet | fd4f2ce | 2012-04-12 19:48:40 +0000 | [diff] [blame] | 135 | #define TCP_TIMEOUT_INIT ((unsigned)(1*HZ)) /* RFC6298 2.1 initial RTO value */ |
Jerry Chu | 9ad7c04 | 2011-06-08 11:08:38 +0000 | [diff] [blame] | 136 | #define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now |
| 137 | * used as a fallback RTO for the |
| 138 | * initial data transmission if no |
| 139 | * valid RTT sample has been acquired, |
| 140 | * most likely due to retrans in 3WHS. |
| 141 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | |
| 143 | #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes |
| 144 | * for local resources. |
| 145 | */ |
| 146 | |
| 147 | #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ |
| 148 | #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ |
| 149 | #define TCP_KEEPALIVE_INTVL (75*HZ) |
| 150 | |
| 151 | #define MAX_TCP_KEEPIDLE 32767 |
| 152 | #define MAX_TCP_KEEPINTVL 32767 |
| 153 | #define MAX_TCP_KEEPCNT 127 |
| 154 | #define MAX_TCP_SYNCNT 127 |
| 155 | |
| 156 | #define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | |
| 158 | #define TCP_PAWS_24DAYS (60 * 60 * 24 * 24) |
| 159 | #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated |
| 160 | * after this time. It should be equal |
| 161 | * (or greater than) TCP_TIMEWAIT_LEN |
| 162 | * to provide reliability equal to one |
| 163 | * provided by timewait state. |
| 164 | */ |
| 165 | #define TCP_PAWS_WINDOW 1 /* Replay window for per-host |
| 166 | * timestamps. It must be less than |
| 167 | * minimal timewait lifetime. |
| 168 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | /* |
| 170 | * TCP option |
| 171 | */ |
Kenjiro Nakayama | 105970f | 2014-10-20 18:15:50 +0900 | [diff] [blame] | 172 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | #define TCPOPT_NOP 1 /* Padding */ |
| 174 | #define TCPOPT_EOL 0 /* End of options */ |
| 175 | #define TCPOPT_MSS 2 /* Segment size negotiating */ |
| 176 | #define TCPOPT_WINDOW 3 /* Window scaling */ |
| 177 | #define TCPOPT_SACK_PERM 4 /* SACK Permitted */ |
| 178 | #define TCPOPT_SACK 5 /* SACK Block */ |
| 179 | #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 180 | #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ |
Daniel Lee | 7f9b838 | 2015-04-06 14:37:26 -0700 | [diff] [blame] | 181 | #define TCPOPT_FASTOPEN 34 /* Fast open (RFC7413) */ |
Yuchung Cheng | 2100c8d | 2012-07-19 06:43:05 +0000 | [diff] [blame] | 182 | #define TCPOPT_EXP 254 /* Experimental */ |
| 183 | /* Magic number to be after the option value for sharing TCP |
| 184 | * experimental options. See draft-ietf-tcpm-experimental-options-00.txt |
| 185 | */ |
| 186 | #define TCPOPT_FASTOPEN_MAGIC 0xF989 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | |
| 188 | /* |
| 189 | * TCP option lengths |
| 190 | */ |
| 191 | |
| 192 | #define TCPOLEN_MSS 4 |
| 193 | #define TCPOLEN_WINDOW 3 |
| 194 | #define TCPOLEN_SACK_PERM 2 |
| 195 | #define TCPOLEN_TIMESTAMP 10 |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 196 | #define TCPOLEN_MD5SIG 18 |
Daniel Lee | 7f9b838 | 2015-04-06 14:37:26 -0700 | [diff] [blame] | 197 | #define TCPOLEN_FASTOPEN_BASE 2 |
Yuchung Cheng | 2100c8d | 2012-07-19 06:43:05 +0000 | [diff] [blame] | 198 | #define TCPOLEN_EXP_FASTOPEN_BASE 4 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | |
| 200 | /* But this is what stacks really send out. */ |
| 201 | #define TCPOLEN_TSTAMP_ALIGNED 12 |
| 202 | #define TCPOLEN_WSCALE_ALIGNED 4 |
| 203 | #define TCPOLEN_SACKPERM_ALIGNED 4 |
| 204 | #define TCPOLEN_SACK_BASE 2 |
| 205 | #define TCPOLEN_SACK_BASE_ALIGNED 4 |
| 206 | #define TCPOLEN_SACK_PERBLOCK 8 |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 207 | #define TCPOLEN_MD5SIG_ALIGNED 20 |
Adam Langley | 33ad798 | 2008-07-19 00:04:31 -0700 | [diff] [blame] | 208 | #define TCPOLEN_MSS_ALIGNED 4 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | /* Flags in tp->nonagle */ |
| 211 | #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */ |
| 212 | #define TCP_NAGLE_CORK 2 /* Socket is corked */ |
Stephen Hemminger | caa20d9a | 2005-11-10 17:13:47 -0800 | [diff] [blame] | 213 | #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 214 | |
Andreas Petlund | 36e31b0a | 2010-02-18 02:47:01 +0000 | [diff] [blame] | 215 | /* TCP thin-stream limits */ |
| 216 | #define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */ |
| 217 | |
Jörg Thalheim | 21603fc | 2016-01-27 22:54:06 +0100 | [diff] [blame] | 218 | /* TCP initial congestion window as per rfc6928 */ |
David S. Miller | 442b963 | 2011-02-02 17:05:11 -0800 | [diff] [blame] | 219 | #define TCP_INIT_CWND 10 |
| 220 | |
Yuchung Cheng | cf60af0 | 2012-07-19 06:43:09 +0000 | [diff] [blame] | 221 | /* Bit Flags for sysctl_tcp_fastopen */ |
| 222 | #define TFO_CLIENT_ENABLE 1 |
Jerry Chu | 1046716 | 2012-08-31 12:29:11 +0000 | [diff] [blame] | 223 | #define TFO_SERVER_ENABLE 2 |
Yuchung Cheng | 67da22d | 2012-07-19 06:43:11 +0000 | [diff] [blame] | 224 | #define TFO_CLIENT_NO_COOKIE 4 /* Data in SYN w/o cookie option */ |
Yuchung Cheng | cf60af0 | 2012-07-19 06:43:09 +0000 | [diff] [blame] | 225 | |
Jerry Chu | 1046716 | 2012-08-31 12:29:11 +0000 | [diff] [blame] | 226 | /* Accept SYN data w/o any cookie option */ |
| 227 | #define TFO_SERVER_COOKIE_NOT_REQD 0x200 |
| 228 | |
| 229 | /* Force enable TFO on all listeners, i.e., not requiring the |
Yuchung Cheng | cebc5cb | 2016-08-22 17:17:54 -0700 | [diff] [blame] | 230 | * TCP_FASTOPEN socket option. |
Jerry Chu | 1046716 | 2012-08-31 12:29:11 +0000 | [diff] [blame] | 231 | */ |
| 232 | #define TFO_SERVER_WO_SOCKOPT1 0x400 |
Jerry Chu | 1046716 | 2012-08-31 12:29:11 +0000 | [diff] [blame] | 233 | |
Arnaldo Carvalho de Melo | 295ff7e | 2005-08-09 20:44:40 -0700 | [diff] [blame] | 234 | extern struct inet_timewait_death_row tcp_death_row; |
| 235 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | /* sysctl variables for tcp */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | extern int sysctl_tcp_timestamps; |
| 238 | extern int sysctl_tcp_window_scaling; |
| 239 | extern int sysctl_tcp_sack; |
Yuchung Cheng | 2100c8d | 2012-07-19 06:43:05 +0000 | [diff] [blame] | 240 | extern int sysctl_tcp_fastopen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | extern int sysctl_tcp_retrans_collapse; |
| 242 | extern int sysctl_tcp_stdurg; |
| 243 | extern int sysctl_tcp_rfc1337; |
| 244 | extern int sysctl_tcp_abort_on_overflow; |
| 245 | extern int sysctl_tcp_max_orphans; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | extern int sysctl_tcp_fack; |
| 247 | extern int sysctl_tcp_reordering; |
Eric Dumazet | dca145f | 2014-10-27 21:45:24 -0700 | [diff] [blame] | 248 | extern int sysctl_tcp_max_reordering; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | extern int sysctl_tcp_dsack; |
Eric W. Biederman | a4fe34b | 2013-10-19 16:25:36 -0700 | [diff] [blame] | 250 | extern long sysctl_tcp_mem[3]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | extern int sysctl_tcp_wmem[3]; |
| 252 | extern int sysctl_tcp_rmem[3]; |
| 253 | extern int sysctl_tcp_app_win; |
| 254 | extern int sysctl_tcp_adv_win_scale; |
| 255 | extern int sysctl_tcp_tw_reuse; |
| 256 | extern int sysctl_tcp_frto; |
| 257 | extern int sysctl_tcp_low_latency; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | extern int sysctl_tcp_nometrics_save; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | extern int sysctl_tcp_moderate_rcvbuf; |
| 260 | extern int sysctl_tcp_tso_win_divisor; |
Rick Jones | 15d99e0 | 2006-03-20 22:40:29 -0800 | [diff] [blame] | 261 | extern int sysctl_tcp_workaround_signed_windows; |
David S. Miller | 35089bb | 2006-06-13 22:33:04 -0700 | [diff] [blame] | 262 | extern int sysctl_tcp_slow_start_after_idle; |
Andreas Petlund | 36e31b0a | 2010-02-18 02:47:01 +0000 | [diff] [blame] | 263 | extern int sysctl_tcp_thin_linear_timeouts; |
Andreas Petlund | 7e38017 | 2010-02-18 04:48:19 +0000 | [diff] [blame] | 264 | extern int sysctl_tcp_thin_dupack; |
Yuchung Cheng | eed530b | 2012-05-02 13:30:03 +0000 | [diff] [blame] | 265 | extern int sysctl_tcp_early_retrans; |
Eric Dumazet | 46d3cea | 2012-07-11 05:50:31 +0000 | [diff] [blame] | 266 | extern int sysctl_tcp_limit_output_bytes; |
Eric Dumazet | 282f23c | 2012-07-17 10:13:05 +0200 | [diff] [blame] | 267 | extern int sysctl_tcp_challenge_ack_limit; |
Eric Dumazet | 95bd09e | 2013-08-27 05:46:32 -0700 | [diff] [blame] | 268 | extern int sysctl_tcp_min_tso_segs; |
Yuchung Cheng | f672258 | 2015-10-16 21:57:42 -0700 | [diff] [blame] | 269 | extern int sysctl_tcp_min_rtt_wlen; |
Eric Dumazet | f54b311 | 2013-12-05 22:36:05 -0800 | [diff] [blame] | 270 | extern int sysctl_tcp_autocorking; |
Neal Cardwell | 032ee42 | 2015-02-06 16:04:38 -0500 | [diff] [blame] | 271 | extern int sysctl_tcp_invalid_ratelimit; |
Eric Dumazet | 43e122b | 2015-08-21 17:38:02 -0700 | [diff] [blame] | 272 | extern int sysctl_tcp_pacing_ss_ratio; |
| 273 | extern int sysctl_tcp_pacing_ca_ratio; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 274 | |
Eric Dumazet | 8d987e5 | 2010-11-09 23:24:26 +0000 | [diff] [blame] | 275 | extern atomic_long_t tcp_memory_allocated; |
Eric Dumazet | 1748376 | 2008-11-25 21:16:35 -0800 | [diff] [blame] | 276 | extern struct percpu_counter tcp_sockets_allocated; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | extern int tcp_memory_pressure; |
| 278 | |
Eric Dumazet | b8da51e | 2015-05-15 12:39:27 -0700 | [diff] [blame] | 279 | /* optimized version of sk_under_memory_pressure() for TCP sockets */ |
| 280 | static inline bool tcp_under_memory_pressure(const struct sock *sk) |
| 281 | { |
Johannes Weiner | baac50b | 2016-01-14 15:21:17 -0800 | [diff] [blame] | 282 | if (mem_cgroup_sockets_enabled && sk->sk_memcg && |
| 283 | mem_cgroup_under_socket_pressure(sk->sk_memcg)) |
Johannes Weiner | e805605 | 2016-01-14 15:21:14 -0800 | [diff] [blame] | 284 | return true; |
Eric Dumazet | b8da51e | 2015-05-15 12:39:27 -0700 | [diff] [blame] | 285 | |
| 286 | return tcp_memory_pressure; |
| 287 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 288 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 289 | * The next routines deal with comparing 32 bit unsigned ints |
| 290 | * and worry about wraparound (automatic with unsigned arithmetic). |
| 291 | */ |
| 292 | |
Eric Dumazet | a2a385d | 2012-05-16 23:15:34 +0000 | [diff] [blame] | 293 | static inline bool before(__u32 seq1, __u32 seq2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 294 | { |
Gerrit Renker | 0d630cc | 2007-01-04 12:25:16 -0800 | [diff] [blame] | 295 | return (__s32)(seq1-seq2) < 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 296 | } |
Gerrit Renker | 9a036b9c | 2006-12-20 10:25:55 -0800 | [diff] [blame] | 297 | #define after(seq2, seq1) before(seq1, seq2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 298 | |
| 299 | /* is s2<=s1<=s3 ? */ |
Eric Dumazet | a2a385d | 2012-05-16 23:15:34 +0000 | [diff] [blame] | 300 | static inline bool between(__u32 seq1, __u32 seq2, __u32 seq3) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | { |
| 302 | return seq3 - seq2 >= seq1 - seq2; |
| 303 | } |
| 304 | |
Arun Sharma | efcdbf2 | 2012-01-30 14:16:06 -0800 | [diff] [blame] | 305 | static inline bool tcp_out_of_memory(struct sock *sk) |
| 306 | { |
| 307 | if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && |
| 308 | sk_memory_allocated(sk) > sk_prot_mem_limits(sk, 2)) |
| 309 | return true; |
| 310 | return false; |
| 311 | } |
| 312 | |
Eric Dumazet | a6c5ea4 | 2015-05-15 12:39:26 -0700 | [diff] [blame] | 313 | void sk_forced_mem_schedule(struct sock *sk, int size); |
| 314 | |
David S. Miller | ad1af0f | 2010-08-25 02:27:49 -0700 | [diff] [blame] | 315 | static inline bool tcp_too_many_orphans(struct sock *sk, int shift) |
Pavel Emelianov | e4fd5da | 2007-05-29 13:19:18 -0700 | [diff] [blame] | 316 | { |
David S. Miller | ad1af0f | 2010-08-25 02:27:49 -0700 | [diff] [blame] | 317 | struct percpu_counter *ocp = sk->sk_prot->orphan_count; |
| 318 | int orphans = percpu_counter_read_positive(ocp); |
| 319 | |
| 320 | if (orphans << shift > sysctl_tcp_max_orphans) { |
| 321 | orphans = percpu_counter_sum_positive(ocp); |
| 322 | if (orphans << shift > sysctl_tcp_max_orphans) |
| 323 | return true; |
| 324 | } |
David S. Miller | ad1af0f | 2010-08-25 02:27:49 -0700 | [diff] [blame] | 325 | return false; |
Pavel Emelianov | e4fd5da | 2007-05-29 13:19:18 -0700 | [diff] [blame] | 326 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 328 | bool tcp_check_oom(struct sock *sk, int shift); |
Arun Sharma | efcdbf2 | 2012-01-30 14:16:06 -0800 | [diff] [blame] | 329 | |
Florian Westphal | a0f82f6 | 2009-04-19 09:43:48 +0000 | [diff] [blame] | 330 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | extern struct proto tcp_prot; |
| 332 | |
Pavel Emelyanov | 57ef42d | 2008-07-18 04:02:08 -0700 | [diff] [blame] | 333 | #define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
Eric Dumazet | 13415e4 | 2016-04-27 16:44:43 -0700 | [diff] [blame] | 334 | #define __TCP_INC_STATS(net, field) __SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
Pavel Emelyanov | 57ef42d | 2008-07-18 04:02:08 -0700 | [diff] [blame] | 335 | #define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field) |
Tom Herbert | aa2ea05 | 2010-04-22 07:00:24 +0000 | [diff] [blame] | 336 | #define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 338 | void tcp_tasklet_init(void); |
Eric Dumazet | 46d3cea | 2012-07-11 05:50:31 +0000 | [diff] [blame] | 339 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 340 | void tcp_v4_err(struct sk_buff *skb, u32); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 342 | void tcp_shutdown(struct sock *sk, int how); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 343 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 344 | void tcp_v4_early_demux(struct sk_buff *skb); |
| 345 | int tcp_v4_rcv(struct sk_buff *skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 347 | int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw); |
Ying Xue | 1b78414 | 2015-03-02 15:37:48 +0800 | [diff] [blame] | 348 | int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 349 | int tcp_sendpage(struct sock *sk, struct page *page, int offset, size_t size, |
| 350 | int flags); |
| 351 | void tcp_release_cb(struct sock *sk); |
| 352 | void tcp_wfree(struct sk_buff *skb); |
| 353 | void tcp_write_timer_handler(struct sock *sk); |
| 354 | void tcp_delack_timer_handler(struct sock *sk); |
| 355 | int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg); |
Eric Dumazet | 72ab4a8 | 2015-09-29 07:42:41 -0700 | [diff] [blame] | 356 | int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 357 | void tcp_rcv_established(struct sock *sk, struct sk_buff *skb, |
| 358 | const struct tcphdr *th, unsigned int len); |
| 359 | void tcp_rcv_space_adjust(struct sock *sk); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 360 | int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); |
| 361 | void tcp_twsk_destructor(struct sock *sk); |
| 362 | ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, |
| 363 | struct pipe_inode_info *pipe, size_t len, |
| 364 | unsigned int flags); |
Jens Axboe | 9c55e01 | 2007-11-06 23:30:13 -0800 | [diff] [blame] | 365 | |
Eric Dumazet | 90cf17d | 2018-05-21 15:08:56 -0700 | [diff] [blame] | 366 | void tcp_enter_quickack_mode(struct sock *sk, unsigned int max_quickacks); |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 367 | static inline void tcp_dec_quickack_mode(struct sock *sk, |
| 368 | const unsigned int pkts) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | { |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 370 | struct inet_connection_sock *icsk = inet_csk(sk); |
David S. Miller | fc6415bc | 2005-07-05 15:17:45 -0700 | [diff] [blame] | 371 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 372 | if (icsk->icsk_ack.quick) { |
| 373 | if (pkts >= icsk->icsk_ack.quick) { |
| 374 | icsk->icsk_ack.quick = 0; |
David S. Miller | fc6415bc | 2005-07-05 15:17:45 -0700 | [diff] [blame] | 375 | /* Leaving quickack mode we deflate ATO. */ |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 376 | icsk->icsk_ack.ato = TCP_ATO_MIN; |
David S. Miller | fc6415bc | 2005-07-05 15:17:45 -0700 | [diff] [blame] | 377 | } else |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 378 | icsk->icsk_ack.quick -= pkts; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 379 | } |
| 380 | } |
| 381 | |
Ilpo Järvinen | bdf1ee5 | 2007-05-27 02:04:16 -0700 | [diff] [blame] | 382 | #define TCP_ECN_OK 1 |
| 383 | #define TCP_ECN_QUEUE_CWR 2 |
| 384 | #define TCP_ECN_DEMAND_CWR 4 |
Eric Dumazet | 7a269ff | 2011-09-22 20:02:19 +0000 | [diff] [blame] | 385 | #define TCP_ECN_SEEN 8 |
Ilpo Järvinen | bdf1ee5 | 2007-05-27 02:04:16 -0700 | [diff] [blame] | 386 | |
Eric Dumazet | fd2c3ef | 2009-11-03 03:26:03 +0000 | [diff] [blame] | 387 | enum tcp_tw_status { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | TCP_TW_SUCCESS = 0, |
| 389 | TCP_TW_RST = 1, |
| 390 | TCP_TW_ACK = 2, |
| 391 | TCP_TW_SYN = 3 |
| 392 | }; |
| 393 | |
| 394 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 395 | enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, |
| 396 | struct sk_buff *skb, |
| 397 | const struct tcphdr *th); |
| 398 | struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb, |
Eric Dumazet | 52452c5 | 2015-03-19 19:04:19 -0700 | [diff] [blame] | 399 | struct request_sock *req, bool fastopen); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 400 | int tcp_child_process(struct sock *parent, struct sock *child, |
| 401 | struct sk_buff *skb); |
Neal Cardwell | 5ae344c | 2014-08-04 19:12:29 -0400 | [diff] [blame] | 402 | void tcp_enter_loss(struct sock *sk); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 403 | void tcp_clear_retrans(struct tcp_sock *tp); |
| 404 | void tcp_update_metrics(struct sock *sk); |
| 405 | void tcp_init_metrics(struct sock *sk); |
| 406 | void tcp_metrics_init(void); |
| 407 | bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst, |
Hannes Frederic Sowa | a26552a | 2014-08-14 22:06:12 +0200 | [diff] [blame] | 408 | bool paws_check, bool timestamps); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 409 | bool tcp_remember_stamp(struct sock *sk); |
| 410 | bool tcp_tw_remember_stamp(struct inet_timewait_sock *tw); |
| 411 | void tcp_fetch_timewait_stamp(struct sock *sk, struct dst_entry *dst); |
| 412 | void tcp_disable_fack(struct tcp_sock *tp); |
| 413 | void tcp_close(struct sock *sk, long timeout); |
| 414 | void tcp_init_sock(struct sock *sk); |
| 415 | unsigned int tcp_poll(struct file *file, struct socket *sock, |
| 416 | struct poll_table_struct *wait); |
| 417 | int tcp_getsockopt(struct sock *sk, int level, int optname, |
| 418 | char __user *optval, int __user *optlen); |
| 419 | int tcp_setsockopt(struct sock *sk, int level, int optname, |
| 420 | char __user *optval, unsigned int optlen); |
| 421 | int compat_tcp_getsockopt(struct sock *sk, int level, int optname, |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 422 | char __user *optval, int __user *optlen); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 423 | int compat_tcp_setsockopt(struct sock *sk, int level, int optname, |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 424 | char __user *optval, unsigned int optlen); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 425 | void tcp_set_keepalive(struct sock *sk, int val); |
Eric Dumazet | 42cb80a | 2015-03-22 10:22:19 -0700 | [diff] [blame] | 426 | void tcp_syn_ack_timeout(const struct request_sock *req); |
Ying Xue | 1b78414 | 2015-03-02 15:37:48 +0800 | [diff] [blame] | 427 | int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock, |
| 428 | int flags, int *addr_len); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 429 | void tcp_parse_options(const struct sk_buff *skb, |
| 430 | struct tcp_options_received *opt_rx, |
| 431 | int estab, struct tcp_fastopen_cookie *foc); |
| 432 | const u8 *tcp_parse_md5sig_option(const struct tcphdr *th); |
YOSHIFUJI Hideaki | 7d5d552 | 2008-04-17 12:29:53 +0900 | [diff] [blame] | 433 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | /* |
| 435 | * TCP v4 functions exported for the inet6 API |
| 436 | */ |
| 437 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 438 | void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); |
Neal Cardwell | 4fab907 | 2014-08-14 12:40:05 -0400 | [diff] [blame] | 439 | void tcp_v4_mtu_reduced(struct sock *sk); |
Eric Dumazet | 9cf7490 | 2016-02-02 19:31:12 -0800 | [diff] [blame] | 440 | void tcp_req_err(struct sock *sk, u32 seq, bool abort); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 441 | int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); |
Eric Dumazet | c28c6f0 | 2015-09-29 07:42:47 -0700 | [diff] [blame] | 442 | struct sock *tcp_create_openreq_child(const struct sock *sk, |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 443 | struct request_sock *req, |
| 444 | struct sk_buff *skb); |
Daniel Borkmann | 8116441 | 2015-01-05 23:57:48 +0100 | [diff] [blame] | 445 | void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst); |
Eric Dumazet | 0c27171 | 2015-09-29 07:42:48 -0700 | [diff] [blame] | 446 | struct sock *tcp_v4_syn_recv_sock(const struct sock *sk, struct sk_buff *skb, |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 447 | struct request_sock *req, |
Eric Dumazet | 5e0724d | 2015-10-22 08:20:46 -0700 | [diff] [blame] | 448 | struct dst_entry *dst, |
| 449 | struct request_sock *req_unhash, |
| 450 | bool *own_req); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 451 | int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); |
| 452 | int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len); |
| 453 | int tcp_connect(struct sock *sk); |
Eric Dumazet | b3d0514 | 2016-04-13 22:05:39 -0700 | [diff] [blame] | 454 | enum tcp_synack_type { |
| 455 | TCP_SYNACK_NORMAL, |
| 456 | TCP_SYNACK_FASTOPEN, |
| 457 | TCP_SYNACK_COOKIE, |
| 458 | }; |
Eric Dumazet | 5d062de | 2015-09-25 07:39:19 -0700 | [diff] [blame] | 459 | struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst, |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 460 | struct request_sock *req, |
Eric Dumazet | ca6fb06 | 2015-10-02 11:43:35 -0700 | [diff] [blame] | 461 | struct tcp_fastopen_cookie *foc, |
Eric Dumazet | b3d0514 | 2016-04-13 22:05:39 -0700 | [diff] [blame] | 462 | enum tcp_synack_type synack_type); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 463 | int tcp_disconnect(struct sock *sk, int flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 464 | |
Pavel Emelyanov | 370816a | 2012-04-19 03:40:01 +0000 | [diff] [blame] | 465 | void tcp_finish_connect(struct sock *sk, struct sk_buff *skb); |
Pavel Emelyanov | 292e8d8 | 2012-05-10 01:49:41 +0000 | [diff] [blame] | 466 | int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size); |
Eric Dumazet | 63d02d1 | 2012-08-09 14:11:00 +0000 | [diff] [blame] | 467 | void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 468 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 469 | /* From syncookies.c */ |
Eric Dumazet | b80c0e7 | 2015-06-04 18:30:43 -0700 | [diff] [blame] | 470 | struct sock *tcp_get_cookie_sock(struct sock *sk, struct sk_buff *skb, |
| 471 | struct request_sock *req, |
| 472 | struct dst_entry *dst); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 473 | int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th, |
| 474 | u32 cookie); |
Cong Wang | 461b74c | 2014-10-15 14:33:22 -0700 | [diff] [blame] | 475 | struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb); |
Eric Dumazet | e05c82d | 2011-09-18 21:02:55 -0400 | [diff] [blame] | 476 | #ifdef CONFIG_SYN_COOKIES |
Florian Westphal | 8c27bd7 | 2013-09-20 22:32:55 +0200 | [diff] [blame] | 477 | |
Eric Dumazet | 6326231 | 2014-03-19 21:02:21 -0700 | [diff] [blame] | 478 | /* Syncookies use a monotonic timer which increments every 60 seconds. |
Florian Westphal | 8c27bd7 | 2013-09-20 22:32:55 +0200 | [diff] [blame] | 479 | * This counter is used both as a hash input and partially encoded into |
| 480 | * the cookie value. A cookie is only validated further if the delta |
| 481 | * between the current counter value and the encoded one is less than this, |
Eric Dumazet | 6326231 | 2014-03-19 21:02:21 -0700 | [diff] [blame] | 482 | * i.e. a sent cookie is valid only at most for 2*60 seconds (or less if |
Florian Westphal | 8c27bd7 | 2013-09-20 22:32:55 +0200 | [diff] [blame] | 483 | * the counter advances immediately after a cookie is generated). |
| 484 | */ |
Eric Dumazet | 264ea10 | 2015-05-14 14:26:56 -0700 | [diff] [blame] | 485 | #define MAX_SYNCOOKIE_AGE 2 |
| 486 | #define TCP_SYNCOOKIE_PERIOD (60 * HZ) |
| 487 | #define TCP_SYNCOOKIE_VALID (MAX_SYNCOOKIE_AGE * TCP_SYNCOOKIE_PERIOD) |
| 488 | |
| 489 | /* syncookies: remember time of last synqueue overflow |
| 490 | * But do not dirty this field too often (once per second is enough) |
Eric Dumazet | 3f684b4 | 2015-09-29 07:42:49 -0700 | [diff] [blame] | 491 | * It is racy as we do not hold a lock, but race is very minor. |
Eric Dumazet | 264ea10 | 2015-05-14 14:26:56 -0700 | [diff] [blame] | 492 | */ |
Eric Dumazet | 3f684b4 | 2015-09-29 07:42:49 -0700 | [diff] [blame] | 493 | static inline void tcp_synq_overflow(const struct sock *sk) |
Eric Dumazet | 264ea10 | 2015-05-14 14:26:56 -0700 | [diff] [blame] | 494 | { |
| 495 | unsigned long last_overflow = tcp_sk(sk)->rx_opt.ts_recent_stamp; |
| 496 | unsigned long now = jiffies; |
| 497 | |
| 498 | if (time_after(now, last_overflow + HZ)) |
| 499 | tcp_sk(sk)->rx_opt.ts_recent_stamp = now; |
| 500 | } |
| 501 | |
| 502 | /* syncookies: no recent synqueue overflow on this listening socket? */ |
| 503 | static inline bool tcp_synq_no_recent_overflow(const struct sock *sk) |
| 504 | { |
| 505 | unsigned long last_overflow = tcp_sk(sk)->rx_opt.ts_recent_stamp; |
| 506 | |
| 507 | return time_after(jiffies, last_overflow + TCP_SYNCOOKIE_VALID); |
| 508 | } |
Florian Westphal | 8c27bd7 | 2013-09-20 22:32:55 +0200 | [diff] [blame] | 509 | |
| 510 | static inline u32 tcp_cookie_time(void) |
| 511 | { |
Eric Dumazet | 6326231 | 2014-03-19 21:02:21 -0700 | [diff] [blame] | 512 | u64 val = get_jiffies_64(); |
| 513 | |
Eric Dumazet | 264ea10 | 2015-05-14 14:26:56 -0700 | [diff] [blame] | 514 | do_div(val, TCP_SYNCOOKIE_PERIOD); |
Eric Dumazet | 6326231 | 2014-03-19 21:02:21 -0700 | [diff] [blame] | 515 | return val; |
Florian Westphal | 8c27bd7 | 2013-09-20 22:32:55 +0200 | [diff] [blame] | 516 | } |
| 517 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 518 | u32 __cookie_v4_init_sequence(const struct iphdr *iph, const struct tcphdr *th, |
| 519 | u16 *mssp); |
Eric Dumazet | 3f684b4 | 2015-09-29 07:42:49 -0700 | [diff] [blame] | 520 | __u32 cookie_v4_init_sequence(const struct sk_buff *skb, __u16 *mss); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 521 | __u32 cookie_init_timestamp(struct request_sock *req); |
Florian Westphal | f167338 | 2014-11-03 17:35:02 +0100 | [diff] [blame] | 522 | bool cookie_timestamp_decode(struct tcp_options_received *opt); |
| 523 | bool cookie_ecn_ok(const struct tcp_options_received *opt, |
Florian Westphal | f7b3bec | 2014-11-03 17:35:03 +0100 | [diff] [blame] | 524 | const struct net *net, const struct dst_entry *dst); |
Florian Westphal | 4dfc281 | 2008-04-10 03:12:40 -0700 | [diff] [blame] | 525 | |
Glenn Griffin | c6aefaf | 2008-02-07 21:49:26 -0800 | [diff] [blame] | 526 | /* From net/ipv6/syncookies.c */ |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 527 | int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th, |
| 528 | u32 cookie); |
| 529 | struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); |
Florian Westphal | f167338 | 2014-11-03 17:35:02 +0100 | [diff] [blame] | 530 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 531 | u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph, |
| 532 | const struct tcphdr *th, u16 *mssp); |
Eric Dumazet | 3f684b4 | 2015-09-29 07:42:49 -0700 | [diff] [blame] | 533 | __u32 cookie_v6_init_sequence(const struct sk_buff *skb, __u16 *mss); |
Eric Dumazet | e05c82d | 2011-09-18 21:02:55 -0400 | [diff] [blame] | 534 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 535 | /* tcp_output.c */ |
| 536 | |
Neal Cardwell | 1b3878c | 2016-09-19 23:39:18 -0400 | [diff] [blame] | 537 | u32 tcp_tso_autosize(const struct sock *sk, unsigned int mss_now, |
| 538 | int min_tso_segs); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 539 | void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, |
| 540 | int nonagle); |
| 541 | bool tcp_may_send_now(struct sock *sk); |
Eric Dumazet | 10d3be5 | 2016-04-21 10:55:23 -0700 | [diff] [blame] | 542 | int __tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); |
| 543 | int tcp_retransmit_skb(struct sock *sk, struct sk_buff *skb, int segs); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 544 | void tcp_retransmit_timer(struct sock *sk); |
| 545 | void tcp_xmit_retransmit_queue(struct sock *); |
| 546 | void tcp_simple_retransmit(struct sock *); |
| 547 | int tcp_trim_head(struct sock *, struct sk_buff *, u32); |
Octavian Purdila | 6cc55e0 | 2014-06-06 17:32:37 +0300 | [diff] [blame] | 548 | int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int, gfp_t); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 549 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 550 | void tcp_send_probe0(struct sock *); |
| 551 | void tcp_send_partial(struct sock *); |
Eric Dumazet | e520af4 | 2015-05-06 14:26:25 -0700 | [diff] [blame] | 552 | int tcp_write_wakeup(struct sock *, int mib); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 553 | void tcp_send_fin(struct sock *sk); |
| 554 | void tcp_send_active_reset(struct sock *sk, gfp_t priority); |
| 555 | int tcp_send_synack(struct sock *); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 556 | void tcp_push_one(struct sock *, unsigned int mss_now); |
Yuchung Cheng | 57ec882 | 2018-07-18 13:56:35 -0700 | [diff] [blame] | 557 | void __tcp_send_ack(struct sock *sk, u32 rcv_nxt); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 558 | void tcp_send_ack(struct sock *sk); |
| 559 | void tcp_send_delayed_ack(struct sock *sk); |
| 560 | void tcp_send_loss_probe(struct sock *sk); |
| 561 | bool tcp_schedule_loss_probe(struct sock *sk); |
Martin KaFai Lau | cfea5a6 | 2016-04-19 22:39:29 -0700 | [diff] [blame] | 562 | void tcp_skb_collapse_tstamp(struct sk_buff *skb, |
| 563 | const struct sk_buff *next_skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 564 | |
David S. Miller | a762a98 | 2005-07-05 15:18:51 -0700 | [diff] [blame] | 565 | /* tcp_input.c */ |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 566 | void tcp_resume_early_retransmit(struct sock *sk); |
| 567 | void tcp_rearm_rto(struct sock *sk); |
Yuchung Cheng | 0f1c28a | 2015-09-18 11:36:14 -0700 | [diff] [blame] | 568 | void tcp_synack_rtt_meas(struct sock *sk, struct request_sock *req); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 569 | void tcp_reset(struct sock *sk); |
Yuchung Cheng | 4f41b1c | 2015-10-16 21:57:47 -0700 | [diff] [blame] | 570 | void tcp_skb_mark_lost_uncond_verify(struct tcp_sock *tp, struct sk_buff *skb); |
Eric Dumazet | e3e17b7 | 2016-02-06 11:16:28 -0800 | [diff] [blame] | 571 | void tcp_fin(struct sock *sk); |
David S. Miller | a762a98 | 2005-07-05 15:18:51 -0700 | [diff] [blame] | 572 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | /* tcp_timer.c */ |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 574 | void tcp_init_xmit_timers(struct sock *); |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 575 | static inline void tcp_clear_xmit_timers(struct sock *sk) |
| 576 | { |
| 577 | inet_csk_clear_xmit_timers(sk); |
| 578 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 579 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 580 | unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); |
| 581 | unsigned int tcp_current_mss(struct sock *sk); |
Ilpo Järvinen | 0c54b85 | 2009-03-14 14:23:05 +0000 | [diff] [blame] | 582 | |
| 583 | /* Bound MSS / TSO packet size with the half of the window */ |
| 584 | static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) |
| 585 | { |
Alexey Kuznetsov | 01f83d6 | 2010-09-15 10:27:52 -0700 | [diff] [blame] | 586 | int cutoff; |
| 587 | |
| 588 | /* When peer uses tiny windows, there is no use in packetizing |
| 589 | * to sub-MSS pieces for the sake of SWS or making sure there |
| 590 | * are enough packets in the pipe for fast recovery. |
| 591 | * |
| 592 | * On the other hand, for extremely large MSS devices, handling |
| 593 | * smaller than MSS windows in this way does make sense. |
| 594 | */ |
Seymour, Shane M | 2631b79 | 2016-06-28 23:06:48 +0000 | [diff] [blame] | 595 | if (tp->max_window > TCP_MSS_DEFAULT) |
Alexey Kuznetsov | 01f83d6 | 2010-09-15 10:27:52 -0700 | [diff] [blame] | 596 | cutoff = (tp->max_window >> 1); |
| 597 | else |
| 598 | cutoff = tp->max_window; |
| 599 | |
| 600 | if (cutoff && pktsize > cutoff) |
| 601 | return max_t(int, cutoff, 68U - tp->tcp_header_len); |
Ilpo Järvinen | 0c54b85 | 2009-03-14 14:23:05 +0000 | [diff] [blame] | 602 | else |
| 603 | return pktsize; |
| 604 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 605 | |
Arnaldo Carvalho de Melo | 17b085e | 2005-08-12 12:59:17 -0300 | [diff] [blame] | 606 | /* tcp.c */ |
Eric Dumazet | 0df48c2 | 2015-04-28 15:28:17 -0700 | [diff] [blame] | 607 | void tcp_get_info(struct sock *, struct tcp_info *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 608 | |
| 609 | /* Read 'sendfile()'-style from a TCP socket */ |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 610 | int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, |
| 611 | sk_read_actor_t recv_actor); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 612 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 613 | void tcp_initialize_rcv_mss(struct sock *sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 614 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 615 | int tcp_mtu_to_mss(struct sock *sk, int pmtu); |
| 616 | int tcp_mss_to_mtu(struct sock *sk, int mss); |
| 617 | void tcp_mtup_init(struct sock *sk); |
| 618 | void tcp_init_buffer_space(struct sock *sk); |
John Heffner | 5d424d5 | 2006-03-20 17:53:41 -0800 | [diff] [blame] | 619 | |
Damian Lukowski | f1ecd5d | 2009-08-26 00:16:31 +0000 | [diff] [blame] | 620 | static inline void tcp_bound_rto(const struct sock *sk) |
| 621 | { |
| 622 | if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX) |
| 623 | inet_csk(sk)->icsk_rto = TCP_RTO_MAX; |
| 624 | } |
| 625 | |
| 626 | static inline u32 __tcp_set_rto(const struct tcp_sock *tp) |
| 627 | { |
Eric Dumazet | 740b0f1 | 2014-02-26 14:02:48 -0800 | [diff] [blame] | 628 | return usecs_to_jiffies((tp->srtt_us >> 3) + tp->rttvar_us); |
Damian Lukowski | f1ecd5d | 2009-08-26 00:16:31 +0000 | [diff] [blame] | 629 | } |
| 630 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 631 | static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 632 | { |
| 633 | tp->pred_flags = htonl((tp->tcp_header_len << 26) | |
| 634 | ntohl(TCP_FLAG_ACK) | |
| 635 | snd_wnd); |
| 636 | } |
| 637 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 638 | static inline void tcp_fast_path_on(struct tcp_sock *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 639 | { |
| 640 | __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale); |
| 641 | } |
| 642 | |
Ilpo Järvinen | 9e412ba | 2007-04-20 22:18:02 -0700 | [diff] [blame] | 643 | static inline void tcp_fast_path_check(struct sock *sk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 644 | { |
Ilpo Järvinen | 9e412ba | 2007-04-20 22:18:02 -0700 | [diff] [blame] | 645 | struct tcp_sock *tp = tcp_sk(sk); |
| 646 | |
Yaogong Wang | 9f5afea | 2016-09-07 14:49:28 -0700 | [diff] [blame] | 647 | if (RB_EMPTY_ROOT(&tp->out_of_order_queue) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 648 | tp->rcv_wnd && |
| 649 | atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf && |
| 650 | !tp->urg_data) |
| 651 | tcp_fast_path_on(tp); |
| 652 | } |
| 653 | |
Satoru SATOH | 0c26689 | 2009-05-04 11:11:01 -0700 | [diff] [blame] | 654 | /* Compute the actual rto_min value */ |
| 655 | static inline u32 tcp_rto_min(struct sock *sk) |
| 656 | { |
Eric Dumazet | cf533ea | 2011-10-21 05:22:42 -0400 | [diff] [blame] | 657 | const struct dst_entry *dst = __sk_dst_get(sk); |
Satoru SATOH | 0c26689 | 2009-05-04 11:11:01 -0700 | [diff] [blame] | 658 | u32 rto_min = TCP_RTO_MIN; |
| 659 | |
| 660 | if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) |
| 661 | rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); |
| 662 | return rto_min; |
| 663 | } |
| 664 | |
Eric Dumazet | 740b0f1 | 2014-02-26 14:02:48 -0800 | [diff] [blame] | 665 | static inline u32 tcp_rto_min_us(struct sock *sk) |
| 666 | { |
| 667 | return jiffies_to_usecs(tcp_rto_min(sk)); |
| 668 | } |
| 669 | |
Daniel Borkmann | 8116441 | 2015-01-05 23:57:48 +0100 | [diff] [blame] | 670 | static inline bool tcp_ca_dst_locked(const struct dst_entry *dst) |
| 671 | { |
| 672 | return dst_metric_locked(dst, RTAX_CC_ALGO); |
| 673 | } |
| 674 | |
Yuchung Cheng | f672258 | 2015-10-16 21:57:42 -0700 | [diff] [blame] | 675 | /* Minimum RTT in usec. ~0 means not available. */ |
| 676 | static inline u32 tcp_min_rtt(const struct tcp_sock *tp) |
| 677 | { |
Neal Cardwell | 6403389 | 2016-09-19 23:39:10 -0400 | [diff] [blame] | 678 | return minmax_get(&tp->rtt_min); |
Yuchung Cheng | f672258 | 2015-10-16 21:57:42 -0700 | [diff] [blame] | 679 | } |
| 680 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 681 | /* Compute the actual receive window we are currently advertising. |
| 682 | * Rcv_nxt can be after the window if our peer push more data |
| 683 | * than the offered window. |
| 684 | */ |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 685 | static inline u32 tcp_receive_window(const struct tcp_sock *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 686 | { |
| 687 | s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt; |
| 688 | |
| 689 | if (win < 0) |
| 690 | win = 0; |
| 691 | return (u32) win; |
| 692 | } |
| 693 | |
| 694 | /* Choose a new window, without checks for shrinking, and without |
| 695 | * scaling applied to the result. The caller does these things |
| 696 | * if necessary. This is a "raw" window selection. |
| 697 | */ |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 698 | u32 __tcp_select_window(struct sock *sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 699 | |
Pavel Emelyanov | ee99528 | 2012-04-19 03:40:39 +0000 | [diff] [blame] | 700 | void tcp_send_window_probe(struct sock *sk); |
| 701 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 702 | /* TCP timestamps are only 32-bits, this causes a slight |
| 703 | * complication on 64-bit systems since we store a snapshot |
Stephen Hemminger | 31f3426 | 2005-11-15 15:17:10 -0800 | [diff] [blame] | 704 | * of jiffies in the buffer control blocks below. We decided |
| 705 | * to use only the low 32-bits of jiffies and hide the ugly |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 706 | * casts with the following macro. |
| 707 | */ |
| 708 | #define tcp_time_stamp ((__u32)(jiffies)) |
| 709 | |
Eric Dumazet | 7faee5c | 2014-09-05 15:33:33 -0700 | [diff] [blame] | 710 | static inline u32 tcp_skb_timestamp(const struct sk_buff *skb) |
| 711 | { |
| 712 | return skb->skb_mstamp.stamp_jiffies; |
| 713 | } |
| 714 | |
| 715 | |
Changli Gao | a3433f3 | 2010-06-12 14:01:43 +0000 | [diff] [blame] | 716 | #define tcp_flag_byte(th) (((u_int8_t *)th)[13]) |
| 717 | |
| 718 | #define TCPHDR_FIN 0x01 |
| 719 | #define TCPHDR_SYN 0x02 |
| 720 | #define TCPHDR_RST 0x04 |
| 721 | #define TCPHDR_PSH 0x08 |
| 722 | #define TCPHDR_ACK 0x10 |
| 723 | #define TCPHDR_URG 0x20 |
| 724 | #define TCPHDR_ECE 0x40 |
| 725 | #define TCPHDR_CWR 0x80 |
| 726 | |
Daniel Borkmann | 4921355 | 2015-05-19 21:04:22 +0200 | [diff] [blame] | 727 | #define TCPHDR_SYN_ECN (TCPHDR_SYN | TCPHDR_ECE | TCPHDR_CWR) |
| 728 | |
Stephen Hemminger | caa20d9a | 2005-11-10 17:13:47 -0800 | [diff] [blame] | 729 | /* This is what the send packet queuing engine uses to pass |
Eric Dumazet | f86586f | 2010-07-15 21:41:00 -0700 | [diff] [blame] | 730 | * TCP per-packet control information to the transmission code. |
| 731 | * We also store the host-order sequence numbers in here too. |
| 732 | * This is 44 bytes if IPV6 is enabled. |
| 733 | * If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 734 | */ |
| 735 | struct tcp_skb_cb { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 736 | __u32 seq; /* Starting sequence number */ |
| 737 | __u32 end_seq; /* SEQ + FIN + SYN + datalen */ |
Eric Dumazet | cd7d849 | 2014-09-24 04:11:22 -0700 | [diff] [blame] | 738 | union { |
| 739 | /* Note : tcp_tw_isn is used in input path only |
| 740 | * (isn chosen by tcp_timewait_state_process()) |
| 741 | * |
Eric Dumazet | f69ad29 | 2015-06-11 09:15:18 -0700 | [diff] [blame] | 742 | * tcp_gso_segs/size are used in write queue only, |
| 743 | * cf tcp_skb_pcount()/tcp_skb_mss() |
Eric Dumazet | cd7d849 | 2014-09-24 04:11:22 -0700 | [diff] [blame] | 744 | */ |
| 745 | __u32 tcp_tw_isn; |
Eric Dumazet | f69ad29 | 2015-06-11 09:15:18 -0700 | [diff] [blame] | 746 | struct { |
| 747 | u16 tcp_gso_segs; |
| 748 | u16 tcp_gso_size; |
| 749 | }; |
Eric Dumazet | cd7d849 | 2014-09-24 04:11:22 -0700 | [diff] [blame] | 750 | }; |
Eric Dumazet | 4de075e | 2011-09-27 13:25:05 -0400 | [diff] [blame] | 751 | __u8 tcp_flags; /* TCP header flags. (tcp[13]) */ |
Neal Cardwell | f4f9f6e | 2012-04-16 07:08:06 +0000 | [diff] [blame] | 752 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 753 | __u8 sacked; /* State flags for SACK/FACK. */ |
| 754 | #define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */ |
| 755 | #define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */ |
| 756 | #define TCPCB_LOST 0x04 /* SKB is lost */ |
| 757 | #define TCPCB_TAGBITS 0x07 /* All tag bits */ |
Andrey Vagin | 9d186ca | 2014-08-13 16:03:10 +0400 | [diff] [blame] | 758 | #define TCPCB_REPAIRED 0x10 /* SKB repaired (no skb_mstamp) */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 759 | #define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */ |
Andrey Vagin | 9d186ca | 2014-08-13 16:03:10 +0400 | [diff] [blame] | 760 | #define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS| \ |
| 761 | TCPCB_REPAIRED) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 762 | |
Neal Cardwell | f4f9f6e | 2012-04-16 07:08:06 +0000 | [diff] [blame] | 763 | __u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */ |
Soheil Hassas Yeganeh | 6b08492 | 2016-04-02 23:08:08 -0400 | [diff] [blame] | 764 | __u8 txstamp_ack:1, /* Record TX timestamp for ack? */ |
Martin KaFai Lau | c134ecb | 2016-04-25 14:44:48 -0700 | [diff] [blame] | 765 | eor:1, /* Is skb MSG_EOR marked? */ |
| 766 | unused:6; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 767 | __u32 ack_seq; /* Sequence number ACK'd */ |
Eric Dumazet | 971f10e | 2014-09-27 09:50:57 -0700 | [diff] [blame] | 768 | union { |
Lawrence Brakmo | b75803d | 2016-05-06 20:35:35 -0700 | [diff] [blame] | 769 | struct { |
Yuchung Cheng | b9f6482 | 2016-09-19 23:39:14 -0400 | [diff] [blame] | 770 | /* There is space for up to 24 bytes */ |
Soheil Hassas Yeganeh | d7722e8 | 2016-09-19 23:39:15 -0400 | [diff] [blame] | 771 | __u32 in_flight:30,/* Bytes in flight at transmit */ |
| 772 | is_app_limited:1, /* cwnd not fully used? */ |
| 773 | unused:1; |
Yuchung Cheng | b9f6482 | 2016-09-19 23:39:14 -0400 | [diff] [blame] | 774 | /* pkts S/ACKed so far upon tx of skb, incl retrans: */ |
| 775 | __u32 delivered; |
| 776 | /* start of send pipeline phase */ |
| 777 | struct skb_mstamp first_tx_mstamp; |
| 778 | /* when we reached the "delivered" count */ |
| 779 | struct skb_mstamp delivered_mstamp; |
Lawrence Brakmo | b75803d | 2016-05-06 20:35:35 -0700 | [diff] [blame] | 780 | } tx; /* only used for outgoing skbs */ |
| 781 | union { |
| 782 | struct inet_skb_parm h4; |
Eric Dumazet | 971f10e | 2014-09-27 09:50:57 -0700 | [diff] [blame] | 783 | #if IS_ENABLED(CONFIG_IPV6) |
Lawrence Brakmo | b75803d | 2016-05-06 20:35:35 -0700 | [diff] [blame] | 784 | struct inet6_skb_parm h6; |
Eric Dumazet | 971f10e | 2014-09-27 09:50:57 -0700 | [diff] [blame] | 785 | #endif |
Lawrence Brakmo | b75803d | 2016-05-06 20:35:35 -0700 | [diff] [blame] | 786 | } header; /* For incoming skbs */ |
| 787 | }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 788 | }; |
| 789 | |
| 790 | #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) |
| 791 | |
Eric Dumazet | 870c315 | 2014-10-17 09:17:20 -0700 | [diff] [blame] | 792 | |
Eric Dumazet | 815afe1 | 2014-10-18 08:34:37 -0700 | [diff] [blame] | 793 | #if IS_ENABLED(CONFIG_IPV6) |
Eric Dumazet | 870c315 | 2014-10-17 09:17:20 -0700 | [diff] [blame] | 794 | /* This is the variant of inet6_iif() that must be used by TCP, |
| 795 | * as TCP moves IP6CB into a different location in skb->cb[] |
| 796 | */ |
| 797 | static inline int tcp_v6_iif(const struct sk_buff *skb) |
| 798 | { |
David Ahern | a04a480 | 2016-10-16 20:02:52 -0700 | [diff] [blame] | 799 | bool l3_slave = ipv6_l3mdev_skb(TCP_SKB_CB(skb)->header.h6.flags); |
David Ahern | 74b2058 | 2016-05-10 11:19:50 -0700 | [diff] [blame] | 800 | |
| 801 | return l3_slave ? skb->skb_iif : TCP_SKB_CB(skb)->header.h6.iif; |
Eric Dumazet | 870c315 | 2014-10-17 09:17:20 -0700 | [diff] [blame] | 802 | } |
Eric Dumazet | 815afe1 | 2014-10-18 08:34:37 -0700 | [diff] [blame] | 803 | #endif |
Eric Dumazet | 870c315 | 2014-10-17 09:17:20 -0700 | [diff] [blame] | 804 | |
David Ahern | a04a480 | 2016-10-16 20:02:52 -0700 | [diff] [blame] | 805 | /* TCP_SKB_CB reference means this can not be used from early demux */ |
| 806 | static inline bool inet_exact_dif_match(struct net *net, struct sk_buff *skb) |
| 807 | { |
| 808 | #if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV) |
| 809 | if (!net->ipv4.sysctl_tcp_l3mdev_accept && |
David Ahern | da96786 | 2016-11-02 12:08:25 -0700 | [diff] [blame] | 810 | skb && ipv4_l3mdev_skb(TCP_SKB_CB(skb)->header.h4.flags)) |
David Ahern | a04a480 | 2016-10-16 20:02:52 -0700 | [diff] [blame] | 811 | return true; |
| 812 | #endif |
| 813 | return false; |
| 814 | } |
| 815 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 816 | /* Due to TSO, an SKB can be composed of multiple actual |
| 817 | * packets. To keep these tracked properly, we use this. |
| 818 | */ |
| 819 | static inline int tcp_skb_pcount(const struct sk_buff *skb) |
| 820 | { |
Eric Dumazet | cd7d849 | 2014-09-24 04:11:22 -0700 | [diff] [blame] | 821 | return TCP_SKB_CB(skb)->tcp_gso_segs; |
| 822 | } |
| 823 | |
| 824 | static inline void tcp_skb_pcount_set(struct sk_buff *skb, int segs) |
| 825 | { |
| 826 | TCP_SKB_CB(skb)->tcp_gso_segs = segs; |
| 827 | } |
| 828 | |
| 829 | static inline void tcp_skb_pcount_add(struct sk_buff *skb, int segs) |
| 830 | { |
| 831 | TCP_SKB_CB(skb)->tcp_gso_segs += segs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 832 | } |
| 833 | |
Eric Dumazet | f69ad29 | 2015-06-11 09:15:18 -0700 | [diff] [blame] | 834 | /* This is valid iff skb is in write queue and tcp_skb_pcount() > 1. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 835 | static inline int tcp_skb_mss(const struct sk_buff *skb) |
| 836 | { |
Eric Dumazet | f69ad29 | 2015-06-11 09:15:18 -0700 | [diff] [blame] | 837 | return TCP_SKB_CB(skb)->tcp_gso_size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 838 | } |
| 839 | |
Martin KaFai Lau | c134ecb | 2016-04-25 14:44:48 -0700 | [diff] [blame] | 840 | static inline bool tcp_skb_can_collapse_to(const struct sk_buff *skb) |
| 841 | { |
| 842 | return likely(!TCP_SKB_CB(skb)->eor); |
| 843 | } |
| 844 | |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 845 | /* Events passed to congestion control interface */ |
| 846 | enum tcp_ca_event { |
| 847 | CA_EVENT_TX_START, /* first transmit when no packets in flight */ |
| 848 | CA_EVENT_CWND_RESTART, /* congestion window restart */ |
| 849 | CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 850 | CA_EVENT_LOSS, /* loss timeout */ |
Florian Westphal | 9890092 | 2014-09-26 22:37:35 +0200 | [diff] [blame] | 851 | CA_EVENT_ECN_NO_CE, /* ECT set, but not CE marked */ |
| 852 | CA_EVENT_ECN_IS_CE, /* received CE marked IP packet */ |
| 853 | CA_EVENT_DELAYED_ACK, /* Delayed ack is sent */ |
| 854 | CA_EVENT_NON_DELAYED_ACK, |
Florian Westphal | 7354c8c | 2014-09-26 22:37:34 +0200 | [diff] [blame] | 855 | }; |
| 856 | |
Florian Westphal | 9890092 | 2014-09-26 22:37:35 +0200 | [diff] [blame] | 857 | /* Information about inbound ACK, passed to cong_ops->in_ack_event() */ |
Florian Westphal | 7354c8c | 2014-09-26 22:37:34 +0200 | [diff] [blame] | 858 | enum tcp_ca_ack_event_flags { |
Florian Westphal | 9890092 | 2014-09-26 22:37:35 +0200 | [diff] [blame] | 859 | CA_ACK_SLOWPATH = (1 << 0), /* In slow path processing */ |
| 860 | CA_ACK_WIN_UPDATE = (1 << 1), /* ACK updated window */ |
| 861 | CA_ACK_ECE = (1 << 2), /* ECE bit is set on ack */ |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 862 | }; |
| 863 | |
| 864 | /* |
| 865 | * Interface for adding new TCP congestion control handlers |
| 866 | */ |
| 867 | #define TCP_CA_NAME_MAX 16 |
Stephen Hemminger | 3ff825b | 2006-11-09 16:32:06 -0800 | [diff] [blame] | 868 | #define TCP_CA_MAX 128 |
| 869 | #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) |
| 870 | |
Daniel Borkmann | c5c6a8a | 2015-01-05 23:57:46 +0100 | [diff] [blame] | 871 | #define TCP_CA_UNSPEC 0 |
| 872 | |
Daniel Borkmann | 30e502a | 2014-09-26 22:37:33 +0200 | [diff] [blame] | 873 | /* Algorithm can be set on socket without CAP_NET_ADMIN privileges */ |
Stephen Hemminger | 164891a | 2007-04-23 22:26:16 -0700 | [diff] [blame] | 874 | #define TCP_CONG_NON_RESTRICTED 0x1 |
Daniel Borkmann | 30e502a | 2014-09-26 22:37:33 +0200 | [diff] [blame] | 875 | /* Requires ECN/ECT set on all packets */ |
| 876 | #define TCP_CONG_NEEDS_ECN 0x2 |
Stephen Hemminger | 164891a | 2007-04-23 22:26:16 -0700 | [diff] [blame] | 877 | |
Eric Dumazet | 64f40ff | 2015-04-28 16:23:48 -0700 | [diff] [blame] | 878 | union tcp_cc_info; |
| 879 | |
Lawrence Brakmo | 756ee17 | 2016-05-11 10:02:13 -0700 | [diff] [blame] | 880 | struct ack_sample { |
| 881 | u32 pkts_acked; |
| 882 | s32 rtt_us; |
Lawrence Brakmo | 6f094b9 | 2016-06-08 21:16:44 -0700 | [diff] [blame] | 883 | u32 in_flight; |
Lawrence Brakmo | 756ee17 | 2016-05-11 10:02:13 -0700 | [diff] [blame] | 884 | }; |
| 885 | |
Yuchung Cheng | b9f6482 | 2016-09-19 23:39:14 -0400 | [diff] [blame] | 886 | /* A rate sample measures the number of (original/retransmitted) data |
| 887 | * packets delivered "delivered" over an interval of time "interval_us". |
| 888 | * The tcp_rate.c code fills in the rate sample, and congestion |
| 889 | * control modules that define a cong_control function to run at the end |
| 890 | * of ACK processing can optionally chose to consult this sample when |
| 891 | * setting cwnd and pacing rate. |
| 892 | * A sample is invalid if "delivered" or "interval_us" is negative. |
| 893 | */ |
| 894 | struct rate_sample { |
| 895 | struct skb_mstamp prior_mstamp; /* starting timestamp for interval */ |
| 896 | u32 prior_delivered; /* tp->delivered at "prior_mstamp" */ |
| 897 | s32 delivered; /* number of packets delivered over interval */ |
| 898 | long interval_us; /* time for tp->delivered to incr "delivered" */ |
| 899 | long rtt_us; /* RTT of last (S)ACKed packet (or -1) */ |
| 900 | int losses; /* number of packets marked lost upon ACK */ |
| 901 | u32 acked_sacked; /* number of packets newly (S)ACKed upon ACK */ |
| 902 | u32 prior_in_flight; /* in flight before this ACK */ |
Soheil Hassas Yeganeh | d7722e8 | 2016-09-19 23:39:15 -0400 | [diff] [blame] | 903 | bool is_app_limited; /* is sample from packet with bubble in pipe? */ |
Yuchung Cheng | b9f6482 | 2016-09-19 23:39:14 -0400 | [diff] [blame] | 904 | bool is_retrans; /* is sample from retransmission? */ |
| 905 | }; |
| 906 | |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 907 | struct tcp_congestion_ops { |
| 908 | struct list_head list; |
Daniel Borkmann | c5c6a8a | 2015-01-05 23:57:46 +0100 | [diff] [blame] | 909 | u32 key; |
| 910 | u32 flags; |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 911 | |
| 912 | /* initialize private data (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 913 | void (*init)(struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 914 | /* cleanup private data (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 915 | void (*release)(struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 916 | |
| 917 | /* return slow start threshold (required) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 918 | u32 (*ssthresh)(struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 919 | /* do new cwnd calculation (required) */ |
Eric Dumazet | 2490155 | 2014-05-02 21:18:05 -0700 | [diff] [blame] | 920 | void (*cong_avoid)(struct sock *sk, u32 ack, u32 acked); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 921 | /* call before changing ca_state (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 922 | void (*set_state)(struct sock *sk, u8 new_state); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 923 | /* call when cwnd event occurs (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 924 | void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev); |
Florian Westphal | 7354c8c | 2014-09-26 22:37:34 +0200 | [diff] [blame] | 925 | /* call when ack arrives (optional) */ |
| 926 | void (*in_ack_event)(struct sock *sk, u32 flags); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 927 | /* new value of cwnd after loss (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 928 | u32 (*undo_cwnd)(struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 929 | /* hook for packet ack accounting (optional) */ |
Lawrence Brakmo | 756ee17 | 2016-05-11 10:02:13 -0700 | [diff] [blame] | 930 | void (*pkts_acked)(struct sock *sk, const struct ack_sample *sample); |
Neal Cardwell | ed6e726 | 2016-09-19 23:39:17 -0400 | [diff] [blame] | 931 | /* suggest number of segments for each skb to transmit (optional) */ |
| 932 | u32 (*tso_segs_goal)(struct sock *sk); |
Yuchung Cheng | 77bfc17 | 2016-09-19 23:39:20 -0400 | [diff] [blame] | 933 | /* returns the multiplier used in tcp_sndbuf_expand (optional) */ |
| 934 | u32 (*sndbuf_expand)(struct sock *sk); |
Yuchung Cheng | c040276 | 2016-09-19 23:39:21 -0400 | [diff] [blame] | 935 | /* call when packets are delivered to update cwnd and pacing rate, |
| 936 | * after all the ca_state processing. (optional) |
| 937 | */ |
| 938 | void (*cong_control)(struct sock *sk, const struct rate_sample *rs); |
Arnaldo Carvalho de Melo | 73c1f4a | 2005-08-12 12:51:49 -0300 | [diff] [blame] | 939 | /* get info for inet_diag (optional) */ |
Eric Dumazet | 64f40ff | 2015-04-28 16:23:48 -0700 | [diff] [blame] | 940 | size_t (*get_info)(struct sock *sk, u32 ext, int *attr, |
| 941 | union tcp_cc_info *info); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 942 | |
| 943 | char name[TCP_CA_NAME_MAX]; |
| 944 | struct module *owner; |
| 945 | }; |
| 946 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 947 | int tcp_register_congestion_control(struct tcp_congestion_ops *type); |
| 948 | void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 949 | |
Florian Westphal | 55d8694 | 2014-09-26 22:37:32 +0200 | [diff] [blame] | 950 | void tcp_assign_congestion_control(struct sock *sk); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 951 | void tcp_init_congestion_control(struct sock *sk); |
| 952 | void tcp_cleanup_congestion_control(struct sock *sk); |
| 953 | int tcp_set_default_congestion_control(const char *name); |
| 954 | void tcp_get_default_congestion_control(char *name); |
| 955 | void tcp_get_available_congestion_control(char *buf, size_t len); |
| 956 | void tcp_get_allowed_congestion_control(char *buf, size_t len); |
| 957 | int tcp_set_allowed_congestion_control(char *allowed); |
| 958 | int tcp_set_congestion_control(struct sock *sk, const char *name); |
Neal Cardwell | e73ebb0 | 2015-01-28 20:01:35 -0500 | [diff] [blame] | 959 | u32 tcp_slow_start(struct tcp_sock *tp, u32 acked); |
| 960 | void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w, u32 acked); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 961 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 962 | u32 tcp_reno_ssthresh(struct sock *sk); |
Eric Dumazet | 2490155 | 2014-05-02 21:18:05 -0700 | [diff] [blame] | 963 | void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 acked); |
David S. Miller | a8acfba | 2005-06-23 23:45:02 -0700 | [diff] [blame] | 964 | extern struct tcp_congestion_ops tcp_reno; |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 965 | |
Daniel Borkmann | c5c6a8a | 2015-01-05 23:57:46 +0100 | [diff] [blame] | 966 | struct tcp_congestion_ops *tcp_ca_find_key(u32 key); |
Daniel Borkmann | c3a8d94 | 2015-08-31 15:58:47 +0200 | [diff] [blame] | 967 | u32 tcp_ca_get_key_by_name(const char *name, bool *ecn_ca); |
Daniel Borkmann | ea69763 | 2015-01-05 23:57:47 +0100 | [diff] [blame] | 968 | #ifdef CONFIG_INET |
Daniel Borkmann | c5c6a8a | 2015-01-05 23:57:46 +0100 | [diff] [blame] | 969 | char *tcp_ca_get_name_by_key(u32 key, char *buffer); |
Daniel Borkmann | ea69763 | 2015-01-05 23:57:47 +0100 | [diff] [blame] | 970 | #else |
| 971 | static inline char *tcp_ca_get_name_by_key(u32 key, char *buffer) |
| 972 | { |
| 973 | return NULL; |
| 974 | } |
| 975 | #endif |
Daniel Borkmann | c5c6a8a | 2015-01-05 23:57:46 +0100 | [diff] [blame] | 976 | |
Daniel Borkmann | 30e502a | 2014-09-26 22:37:33 +0200 | [diff] [blame] | 977 | static inline bool tcp_ca_needs_ecn(const struct sock *sk) |
| 978 | { |
| 979 | const struct inet_connection_sock *icsk = inet_csk(sk); |
| 980 | |
| 981 | return icsk->icsk_ca_ops->flags & TCP_CONG_NEEDS_ECN; |
| 982 | } |
| 983 | |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 984 | static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state) |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 985 | { |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 986 | struct inet_connection_sock *icsk = inet_csk(sk); |
| 987 | |
| 988 | if (icsk->icsk_ca_ops->set_state) |
| 989 | icsk->icsk_ca_ops->set_state(sk, ca_state); |
| 990 | icsk->icsk_ca_state = ca_state; |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 991 | } |
| 992 | |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 993 | static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event) |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 994 | { |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 995 | const struct inet_connection_sock *icsk = inet_csk(sk); |
| 996 | |
| 997 | if (icsk->icsk_ca_ops->cwnd_event) |
| 998 | icsk->icsk_ca_ops->cwnd_event(sk, event); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 999 | } |
| 1000 | |
Yuchung Cheng | b9f6482 | 2016-09-19 23:39:14 -0400 | [diff] [blame] | 1001 | /* From tcp_rate.c */ |
| 1002 | void tcp_rate_skb_sent(struct sock *sk, struct sk_buff *skb); |
| 1003 | void tcp_rate_skb_delivered(struct sock *sk, struct sk_buff *skb, |
| 1004 | struct rate_sample *rs); |
| 1005 | void tcp_rate_gen(struct sock *sk, u32 delivered, u32 lost, |
Yousuk Seung | e74fe72 | 2017-12-07 13:41:34 -0800 | [diff] [blame] | 1006 | bool is_sack_reneg, struct skb_mstamp *now, struct rate_sample *rs); |
Soheil Hassas Yeganeh | d7722e8 | 2016-09-19 23:39:15 -0400 | [diff] [blame] | 1007 | void tcp_rate_check_app_limited(struct sock *sk); |
Yuchung Cheng | b9f6482 | 2016-09-19 23:39:14 -0400 | [diff] [blame] | 1008 | |
Ilpo Järvinen | e60402d | 2007-08-09 15:14:46 +0300 | [diff] [blame] | 1009 | /* These functions determine how the current flow behaves in respect of SACK |
| 1010 | * handling. SACK is negotiated with the peer, and therefore it can vary |
| 1011 | * between different flows. |
| 1012 | * |
| 1013 | * tcp_is_sack - SACK enabled |
| 1014 | * tcp_is_reno - No SACK |
| 1015 | * tcp_is_fack - FACK enabled, implies SACK enabled |
| 1016 | */ |
| 1017 | static inline int tcp_is_sack(const struct tcp_sock *tp) |
| 1018 | { |
| 1019 | return tp->rx_opt.sack_ok; |
| 1020 | } |
| 1021 | |
Eric Dumazet | a2a385d | 2012-05-16 23:15:34 +0000 | [diff] [blame] | 1022 | static inline bool tcp_is_reno(const struct tcp_sock *tp) |
Ilpo Järvinen | e60402d | 2007-08-09 15:14:46 +0300 | [diff] [blame] | 1023 | { |
| 1024 | return !tcp_is_sack(tp); |
| 1025 | } |
| 1026 | |
Eric Dumazet | a2a385d | 2012-05-16 23:15:34 +0000 | [diff] [blame] | 1027 | static inline bool tcp_is_fack(const struct tcp_sock *tp) |
Ilpo Järvinen | e60402d | 2007-08-09 15:14:46 +0300 | [diff] [blame] | 1028 | { |
Vijay Subramanian | ab56222 | 2011-12-20 13:23:24 +0000 | [diff] [blame] | 1029 | return tp->rx_opt.sack_ok & TCP_FACK_ENABLED; |
Ilpo Järvinen | e60402d | 2007-08-09 15:14:46 +0300 | [diff] [blame] | 1030 | } |
| 1031 | |
| 1032 | static inline void tcp_enable_fack(struct tcp_sock *tp) |
| 1033 | { |
Vijay Subramanian | ab56222 | 2011-12-20 13:23:24 +0000 | [diff] [blame] | 1034 | tp->rx_opt.sack_ok |= TCP_FACK_ENABLED; |
Ilpo Järvinen | e60402d | 2007-08-09 15:14:46 +0300 | [diff] [blame] | 1035 | } |
| 1036 | |
Yuchung Cheng | eed530b | 2012-05-02 13:30:03 +0000 | [diff] [blame] | 1037 | /* TCP early-retransmit (ER) is similar to but more conservative than |
| 1038 | * the thin-dupack feature. Enable ER only if thin-dupack is disabled. |
| 1039 | */ |
| 1040 | static inline void tcp_enable_early_retrans(struct tcp_sock *tp) |
| 1041 | { |
Nikolay Borisov | 1043e25 | 2016-02-03 09:46:52 +0200 | [diff] [blame] | 1042 | struct net *net = sock_net((struct sock *)tp); |
| 1043 | |
Yuchung Cheng | eed530b | 2012-05-02 13:30:03 +0000 | [diff] [blame] | 1044 | tp->do_early_retrans = sysctl_tcp_early_retrans && |
Nandita Dukkipati | 6ba8a3b | 2013-03-11 10:00:43 +0000 | [diff] [blame] | 1045 | sysctl_tcp_early_retrans < 4 && !sysctl_tcp_thin_dupack && |
Nikolay Borisov | 1043e25 | 2016-02-03 09:46:52 +0200 | [diff] [blame] | 1046 | net->ipv4.sysctl_tcp_reordering == 3; |
Yuchung Cheng | eed530b | 2012-05-02 13:30:03 +0000 | [diff] [blame] | 1047 | } |
| 1048 | |
| 1049 | static inline void tcp_disable_early_retrans(struct tcp_sock *tp) |
| 1050 | { |
| 1051 | tp->do_early_retrans = 0; |
| 1052 | } |
| 1053 | |
Ilpo Järvinen | 83ae408 | 2007-08-09 14:37:30 +0300 | [diff] [blame] | 1054 | static inline unsigned int tcp_left_out(const struct tcp_sock *tp) |
| 1055 | { |
| 1056 | return tp->sacked_out + tp->lost_out; |
| 1057 | } |
| 1058 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1059 | /* This determines how many packets are "in the network" to the best |
| 1060 | * of our knowledge. In many cases it is conservative, but where |
| 1061 | * detailed information is available from the receiver (via SACK |
| 1062 | * blocks etc.) we can make more aggressive calculations. |
| 1063 | * |
| 1064 | * Use this for decisions involving congestion control, use just |
| 1065 | * tp->packets_out to determine if the send queue is empty or not. |
| 1066 | * |
| 1067 | * Read this equation as: |
| 1068 | * |
| 1069 | * "Packets sent once on transmission queue" MINUS |
| 1070 | * "Packets left network, but not honestly ACKed yet" PLUS |
| 1071 | * "Packets fast retransmitted" |
| 1072 | */ |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 1073 | static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1074 | { |
Ilpo Järvinen | 83ae408 | 2007-08-09 14:37:30 +0300 | [diff] [blame] | 1075 | return tp->packets_out - tcp_left_out(tp) + tp->retrans_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1076 | } |
| 1077 | |
Ilpo Järvinen | 0b6a05c | 2009-09-15 01:30:10 -0700 | [diff] [blame] | 1078 | #define TCP_INFINITE_SSTHRESH 0x7fffffff |
| 1079 | |
Yuchung Cheng | 071d508 | 2015-07-09 13:16:29 -0700 | [diff] [blame] | 1080 | static inline bool tcp_in_slow_start(const struct tcp_sock *tp) |
| 1081 | { |
Yuchung Cheng | 7617400 | 2015-07-09 13:16:30 -0700 | [diff] [blame] | 1082 | return tp->snd_cwnd < tp->snd_ssthresh; |
Yuchung Cheng | 071d508 | 2015-07-09 13:16:29 -0700 | [diff] [blame] | 1083 | } |
| 1084 | |
Ilpo Järvinen | 0b6a05c | 2009-09-15 01:30:10 -0700 | [diff] [blame] | 1085 | static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) |
| 1086 | { |
| 1087 | return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; |
| 1088 | } |
| 1089 | |
Yuchung Cheng | 684bad1 | 2012-09-02 17:38:04 +0000 | [diff] [blame] | 1090 | static inline bool tcp_in_cwnd_reduction(const struct sock *sk) |
| 1091 | { |
| 1092 | return (TCPF_CA_CWR | TCPF_CA_Recovery) & |
| 1093 | (1 << inet_csk(sk)->icsk_ca_state); |
| 1094 | } |
| 1095 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1096 | /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. |
Yuchung Cheng | 684bad1 | 2012-09-02 17:38:04 +0000 | [diff] [blame] | 1097 | * The exception is cwnd reduction phase, when cwnd is decreasing towards |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1098 | * ssthresh. |
| 1099 | */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 1100 | static inline __u32 tcp_current_ssthresh(const struct sock *sk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1101 | { |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 1102 | const struct tcp_sock *tp = tcp_sk(sk); |
Eric Dumazet | cf533ea | 2011-10-21 05:22:42 -0400 | [diff] [blame] | 1103 | |
Yuchung Cheng | 684bad1 | 2012-09-02 17:38:04 +0000 | [diff] [blame] | 1104 | if (tcp_in_cwnd_reduction(sk)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1105 | return tp->snd_ssthresh; |
| 1106 | else |
| 1107 | return max(tp->snd_ssthresh, |
| 1108 | ((tp->snd_cwnd >> 1) + |
| 1109 | (tp->snd_cwnd >> 2))); |
| 1110 | } |
| 1111 | |
Ilpo Järvinen | b9c4595 | 2007-07-27 16:36:17 +0300 | [diff] [blame] | 1112 | /* Use define here intentionally to get WARN_ON location shown at the caller */ |
| 1113 | #define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1114 | |
Christoph Paasch | 5ee2c94 | 2014-07-14 16:58:32 +0200 | [diff] [blame] | 1115 | void tcp_enter_cwr(struct sock *sk); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1116 | __u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1117 | |
Neal Cardwell | 6b5a5c0 | 2011-11-21 17:15:14 +0000 | [diff] [blame] | 1118 | /* The maximum number of MSS of available cwnd for which TSO defers |
| 1119 | * sending if not using sysctl_tcp_tso_win_divisor. |
| 1120 | */ |
| 1121 | static inline __u32 tcp_max_tso_deferred_mss(const struct tcp_sock *tp) |
| 1122 | { |
| 1123 | return 3; |
| 1124 | } |
| 1125 | |
Ilpo Järvinen | 90840de | 2007-12-31 04:48:41 -0800 | [diff] [blame] | 1126 | /* Returns end sequence number of the receiver's advertised window */ |
| 1127 | static inline u32 tcp_wnd_end(const struct tcp_sock *tp) |
| 1128 | { |
| 1129 | return tp->snd_una + tp->snd_wnd; |
| 1130 | } |
Eric Dumazet | e114a71 | 2014-04-30 11:58:13 -0700 | [diff] [blame] | 1131 | |
| 1132 | /* We follow the spirit of RFC2861 to validate cwnd but implement a more |
| 1133 | * flexible approach. The RFC suggests cwnd should not be raised unless |
Neal Cardwell | ca8a226 | 2014-05-22 10:41:08 -0400 | [diff] [blame] | 1134 | * it was fully used previously. And that's exactly what we do in |
| 1135 | * congestion avoidance mode. But in slow start we allow cwnd to grow |
| 1136 | * as long as the application has used half the cwnd. |
Eric Dumazet | e114a71 | 2014-04-30 11:58:13 -0700 | [diff] [blame] | 1137 | * Example : |
| 1138 | * cwnd is 10 (IW10), but application sends 9 frames. |
| 1139 | * We allow cwnd to reach 18 when all frames are ACKed. |
| 1140 | * This check is safe because it's as aggressive as slow start which already |
| 1141 | * risks 100% overshoot. The advantage is that we discourage application to |
| 1142 | * either send more filler packets or data to artificially blow up the cwnd |
| 1143 | * usage, and allow application-limited process to probe bw more aggressively. |
Eric Dumazet | e114a71 | 2014-04-30 11:58:13 -0700 | [diff] [blame] | 1144 | */ |
Eric Dumazet | 2490155 | 2014-05-02 21:18:05 -0700 | [diff] [blame] | 1145 | static inline bool tcp_is_cwnd_limited(const struct sock *sk) |
Eric Dumazet | e114a71 | 2014-04-30 11:58:13 -0700 | [diff] [blame] | 1146 | { |
| 1147 | const struct tcp_sock *tp = tcp_sk(sk); |
| 1148 | |
Neal Cardwell | ca8a226 | 2014-05-22 10:41:08 -0400 | [diff] [blame] | 1149 | /* If in slow start, ensure cwnd grows to twice what was ACKed. */ |
Yuchung Cheng | 071d508 | 2015-07-09 13:16:29 -0700 | [diff] [blame] | 1150 | if (tcp_in_slow_start(tp)) |
Neal Cardwell | ca8a226 | 2014-05-22 10:41:08 -0400 | [diff] [blame] | 1151 | return tp->snd_cwnd < 2 * tp->max_packets_out; |
| 1152 | |
| 1153 | return tp->is_cwnd_limited; |
Eric Dumazet | e114a71 | 2014-04-30 11:58:13 -0700 | [diff] [blame] | 1154 | } |
Stephen Hemminger | f4805ed | 2005-11-10 16:53:30 -0800 | [diff] [blame] | 1155 | |
Eric Dumazet | 21c8fe9 | 2015-05-06 14:26:24 -0700 | [diff] [blame] | 1156 | /* Something is really bad, we could not queue an additional packet, |
| 1157 | * because qdisc is full or receiver sent a 0 window. |
| 1158 | * We do not want to add fuel to the fire, or abort too early, |
| 1159 | * so make sure the timer we arm now is at least 200ms in the future, |
| 1160 | * regardless of current icsk_rto value (as it could be ~2ms) |
| 1161 | */ |
| 1162 | static inline unsigned long tcp_probe0_base(const struct sock *sk) |
| 1163 | { |
| 1164 | return max_t(unsigned long, inet_csk(sk)->icsk_rto, TCP_RTO_MIN); |
| 1165 | } |
| 1166 | |
| 1167 | /* Variant of inet_csk_rto_backoff() used for zero window probes */ |
| 1168 | static inline unsigned long tcp_probe0_when(const struct sock *sk, |
| 1169 | unsigned long max_when) |
| 1170 | { |
| 1171 | u64 when = (u64)tcp_probe0_base(sk) << inet_csk(sk)->icsk_backoff; |
| 1172 | |
| 1173 | return (unsigned long)min_t(u64, when, max_when); |
| 1174 | } |
| 1175 | |
Ilpo Järvinen | 9e412ba | 2007-04-20 22:18:02 -0700 | [diff] [blame] | 1176 | static inline void tcp_check_probe_timer(struct sock *sk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1177 | { |
Eric Dumazet | 21c8fe9 | 2015-05-06 14:26:24 -0700 | [diff] [blame] | 1178 | if (!tcp_sk(sk)->packets_out && !inet_csk(sk)->icsk_pending) |
Arnaldo Carvalho de Melo | 3f421ba | 2005-08-09 20:11:08 -0700 | [diff] [blame] | 1179 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0, |
Eric Dumazet | 21c8fe9 | 2015-05-06 14:26:24 -0700 | [diff] [blame] | 1180 | tcp_probe0_base(sk), TCP_RTO_MAX); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1181 | } |
| 1182 | |
Hantzis Fotis | ee7537b | 2009-03-02 22:42:02 -0800 | [diff] [blame] | 1183 | static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1184 | { |
| 1185 | tp->snd_wl1 = seq; |
| 1186 | } |
| 1187 | |
Hantzis Fotis | ee7537b | 2009-03-02 22:42:02 -0800 | [diff] [blame] | 1188 | static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1189 | { |
| 1190 | tp->snd_wl1 = seq; |
| 1191 | } |
| 1192 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1193 | /* |
| 1194 | * Calculate(/check) TCP checksum |
| 1195 | */ |
Frederik Deweerdt | ba7808e | 2007-02-04 20:15:27 -0800 | [diff] [blame] | 1196 | static inline __sum16 tcp_v4_check(int len, __be32 saddr, |
| 1197 | __be32 daddr, __wsum base) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1198 | { |
| 1199 | return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base); |
| 1200 | } |
| 1201 | |
Al Viro | b51655b | 2006-11-14 21:40:42 -0800 | [diff] [blame] | 1202 | static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1203 | { |
Herbert Xu | fb286bb | 2005-11-10 13:01:24 -0800 | [diff] [blame] | 1204 | return __skb_checksum_complete(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1205 | } |
| 1206 | |
Eric Dumazet | a2a385d | 2012-05-16 23:15:34 +0000 | [diff] [blame] | 1207 | static inline bool tcp_checksum_complete(struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1208 | { |
Herbert Xu | 6047637 | 2007-04-09 11:59:39 -0700 | [diff] [blame] | 1209 | return !skb_csum_unnecessary(skb) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1210 | __tcp_checksum_complete(skb); |
| 1211 | } |
| 1212 | |
| 1213 | /* Prequeue for VJ style copy to user, combined with checksumming. */ |
| 1214 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 1215 | static inline void tcp_prequeue_init(struct tcp_sock *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1216 | { |
| 1217 | tp->ucopy.task = NULL; |
| 1218 | tp->ucopy.len = 0; |
| 1219 | tp->ucopy.memory = 0; |
| 1220 | skb_queue_head_init(&tp->ucopy.prequeue); |
| 1221 | } |
| 1222 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1223 | bool tcp_prequeue(struct sock *sk, struct sk_buff *skb); |
Eric Dumazet | c9c3321 | 2016-08-27 07:37:54 -0700 | [diff] [blame] | 1224 | bool tcp_add_backlog(struct sock *sk, struct sk_buff *skb); |
Eric Dumazet | ac6e780 | 2016-11-10 13:12:35 -0800 | [diff] [blame] | 1225 | int tcp_filter(struct sock *sk, struct sk_buff *skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1226 | |
| 1227 | #undef STATE_TRACE |
| 1228 | |
| 1229 | #ifdef STATE_TRACE |
| 1230 | static const char *statename[]={ |
| 1231 | "Unused","Established","Syn Sent","Syn Recv", |
| 1232 | "Fin Wait 1","Fin Wait 2","Time Wait", "Close", |
| 1233 | "Close Wait","Last ACK","Listen","Closing" |
| 1234 | }; |
| 1235 | #endif |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1236 | void tcp_set_state(struct sock *sk, int state); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1237 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1238 | void tcp_done(struct sock *sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1239 | |
Lorenzo Colitti | c1e64e2 | 2015-12-16 12:30:05 +0900 | [diff] [blame] | 1240 | int tcp_abort(struct sock *sk, int err); |
| 1241 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 1242 | static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1243 | { |
| 1244 | rx_opt->dsack = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1245 | rx_opt->num_sacks = 0; |
| 1246 | } |
| 1247 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1248 | u32 tcp_default_init_rwnd(u32 mss); |
Eric Dumazet | 6f021c6 | 2015-08-21 12:30:00 -0700 | [diff] [blame] | 1249 | void tcp_cwnd_restart(struct sock *sk, s32 delta); |
| 1250 | |
| 1251 | static inline void tcp_slow_start_after_idle_check(struct sock *sk) |
| 1252 | { |
| 1253 | struct tcp_sock *tp = tcp_sk(sk); |
| 1254 | s32 delta; |
| 1255 | |
| 1256 | if (!sysctl_tcp_slow_start_after_idle || tp->packets_out) |
| 1257 | return; |
| 1258 | delta = tcp_time_stamp - tp->lsndtime; |
| 1259 | if (delta > inet_csk(sk)->icsk_rto) |
| 1260 | tcp_cwnd_restart(sk, delta); |
| 1261 | } |
Yuchung Cheng | 85f1652 | 2013-06-11 15:35:32 -0700 | [diff] [blame] | 1262 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1263 | /* Determine a window scaling and initial window to offer. */ |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1264 | void tcp_select_initial_window(int __space, __u32 mss, __u32 *rcv_wnd, |
| 1265 | __u32 *window_clamp, int wscale_ok, |
| 1266 | __u8 *rcv_wscale, __u32 init_rcv_wnd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1267 | |
| 1268 | static inline int tcp_win_from_space(int space) |
| 1269 | { |
Gao Feng | 694f219 | 2017-03-24 07:05:12 +0800 | [diff] [blame] | 1270 | int tcp_adv_win_scale = sysctl_tcp_adv_win_scale; |
| 1271 | |
| 1272 | return tcp_adv_win_scale <= 0 ? |
| 1273 | (space>>(-tcp_adv_win_scale)) : |
| 1274 | space - (space>>tcp_adv_win_scale); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1275 | } |
| 1276 | |
Kenjiro Nakayama | 105970f | 2014-10-20 18:15:50 +0900 | [diff] [blame] | 1277 | /* Note: caller must be prepared to deal with negative returns */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1278 | static inline int tcp_space(const struct sock *sk) |
| 1279 | { |
| 1280 | return tcp_win_from_space(sk->sk_rcvbuf - |
| 1281 | atomic_read(&sk->sk_rmem_alloc)); |
Kenjiro Nakayama | 105970f | 2014-10-20 18:15:50 +0900 | [diff] [blame] | 1282 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1283 | |
| 1284 | static inline int tcp_full_space(const struct sock *sk) |
| 1285 | { |
Kenjiro Nakayama | 105970f | 2014-10-20 18:15:50 +0900 | [diff] [blame] | 1286 | return tcp_win_from_space(sk->sk_rcvbuf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1287 | } |
| 1288 | |
Yuchung Cheng | 843f4a5 | 2014-05-11 20:22:11 -0700 | [diff] [blame] | 1289 | extern void tcp_openreq_init_rwin(struct request_sock *req, |
Eric Dumazet | b1964b5 | 2015-09-25 07:39:09 -0700 | [diff] [blame] | 1290 | const struct sock *sk_listener, |
| 1291 | const struct dst_entry *dst); |
Yuchung Cheng | 843f4a5 | 2014-05-11 20:22:11 -0700 | [diff] [blame] | 1292 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1293 | void tcp_enter_memory_pressure(struct sock *sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1294 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1295 | static inline int keepalive_intvl_when(const struct tcp_sock *tp) |
| 1296 | { |
Nikolay Borisov | b840d15 | 2016-01-07 16:38:45 +0200 | [diff] [blame] | 1297 | struct net *net = sock_net((struct sock *)tp); |
| 1298 | |
| 1299 | return tp->keepalive_intvl ? : net->ipv4.sysctl_tcp_keepalive_intvl; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1300 | } |
| 1301 | |
| 1302 | static inline int keepalive_time_when(const struct tcp_sock *tp) |
| 1303 | { |
Nikolay Borisov | 13b287e | 2016-01-07 16:38:43 +0200 | [diff] [blame] | 1304 | struct net *net = sock_net((struct sock *)tp); |
| 1305 | |
| 1306 | return tp->keepalive_time ? : net->ipv4.sysctl_tcp_keepalive_time; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1307 | } |
| 1308 | |
Eric Dumazet | df19a62 | 2009-08-28 23:48:54 -0700 | [diff] [blame] | 1309 | static inline int keepalive_probes(const struct tcp_sock *tp) |
| 1310 | { |
Nikolay Borisov | 9bd6861 | 2016-01-07 16:38:44 +0200 | [diff] [blame] | 1311 | struct net *net = sock_net((struct sock *)tp); |
| 1312 | |
| 1313 | return tp->keepalive_probes ? : net->ipv4.sysctl_tcp_keepalive_probes; |
Eric Dumazet | df19a62 | 2009-08-28 23:48:54 -0700 | [diff] [blame] | 1314 | } |
| 1315 | |
Flavio Leitner | 6c37e5d | 2010-04-26 18:33:27 +0000 | [diff] [blame] | 1316 | static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) |
| 1317 | { |
| 1318 | const struct inet_connection_sock *icsk = &tp->inet_conn; |
| 1319 | |
| 1320 | return min_t(u32, tcp_time_stamp - icsk->icsk_ack.lrcvtime, |
| 1321 | tcp_time_stamp - tp->rcv_tstamp); |
| 1322 | } |
| 1323 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 1324 | static inline int tcp_fin_time(const struct sock *sk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1325 | { |
Nikolay Borisov | 1e579ca | 2016-02-03 09:46:56 +0200 | [diff] [blame] | 1326 | int fin_timeout = tcp_sk(sk)->linger2 ? : sock_net(sk)->ipv4.sysctl_tcp_fin_timeout; |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 1327 | const int rto = inet_csk(sk)->icsk_rto; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1328 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 1329 | if (fin_timeout < (rto << 2) - (rto >> 1)) |
| 1330 | fin_timeout = (rto << 2) - (rto >> 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1331 | |
| 1332 | return fin_timeout; |
| 1333 | } |
| 1334 | |
Eric Dumazet | a2a385d | 2012-05-16 23:15:34 +0000 | [diff] [blame] | 1335 | static inline bool tcp_paws_check(const struct tcp_options_received *rx_opt, |
| 1336 | int paws_win) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1337 | { |
Ilpo Järvinen | c887e6d | 2009-03-14 14:23:03 +0000 | [diff] [blame] | 1338 | if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) |
Eric Dumazet | a2a385d | 2012-05-16 23:15:34 +0000 | [diff] [blame] | 1339 | return true; |
Ilpo Järvinen | c887e6d | 2009-03-14 14:23:03 +0000 | [diff] [blame] | 1340 | if (unlikely(get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)) |
Eric Dumazet | a2a385d | 2012-05-16 23:15:34 +0000 | [diff] [blame] | 1341 | return true; |
Eric Dumazet | bc2ce89 | 2010-12-16 14:08:34 -0800 | [diff] [blame] | 1342 | /* |
| 1343 | * Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0, |
| 1344 | * then following tcp messages have valid values. Ignore 0 value, |
| 1345 | * or else 'negative' tsval might forbid us to accept their packets. |
| 1346 | */ |
| 1347 | if (!rx_opt->ts_recent) |
Eric Dumazet | a2a385d | 2012-05-16 23:15:34 +0000 | [diff] [blame] | 1348 | return true; |
| 1349 | return false; |
Ilpo Järvinen | c887e6d | 2009-03-14 14:23:03 +0000 | [diff] [blame] | 1350 | } |
| 1351 | |
Eric Dumazet | a2a385d | 2012-05-16 23:15:34 +0000 | [diff] [blame] | 1352 | static inline bool tcp_paws_reject(const struct tcp_options_received *rx_opt, |
| 1353 | int rst) |
Ilpo Järvinen | c887e6d | 2009-03-14 14:23:03 +0000 | [diff] [blame] | 1354 | { |
| 1355 | if (tcp_paws_check(rx_opt, 0)) |
Eric Dumazet | a2a385d | 2012-05-16 23:15:34 +0000 | [diff] [blame] | 1356 | return false; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1357 | |
| 1358 | /* RST segments are not recommended to carry timestamp, |
| 1359 | and, if they do, it is recommended to ignore PAWS because |
| 1360 | "their cleanup function should take precedence over timestamps." |
| 1361 | Certainly, it is mistake. It is necessary to understand the reasons |
| 1362 | of this constraint to relax it: if peer reboots, clock may go |
| 1363 | out-of-sync and half-open connections will not be reset. |
| 1364 | Actually, the problem would be not existing if all |
| 1365 | the implementations followed draft about maintaining clock |
| 1366 | via reboots. Linux-2.2 DOES NOT! |
| 1367 | |
| 1368 | However, we can relax time bounds for RST segments to MSL. |
| 1369 | */ |
James Morris | 9d729f7 | 2007-03-04 16:12:44 -0800 | [diff] [blame] | 1370 | if (rst && get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL) |
Eric Dumazet | a2a385d | 2012-05-16 23:15:34 +0000 | [diff] [blame] | 1371 | return false; |
| 1372 | return true; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1373 | } |
| 1374 | |
Eric Dumazet | 7970ddc | 2015-03-16 21:06:20 -0700 | [diff] [blame] | 1375 | bool tcp_oow_rate_limited(struct net *net, const struct sk_buff *skb, |
| 1376 | int mib_idx, u32 *last_oow_ack_time); |
Neal Cardwell | 032ee42 | 2015-02-06 16:04:38 -0500 | [diff] [blame] | 1377 | |
Pavel Emelyanov | a9c19329 | 2008-07-16 20:21:42 -0700 | [diff] [blame] | 1378 | static inline void tcp_mib_init(struct net *net) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1379 | { |
| 1380 | /* See RFC 2012 */ |
Eric Dumazet | 6aef70a | 2016-04-27 16:44:27 -0700 | [diff] [blame] | 1381 | TCP_ADD_STATS(net, TCP_MIB_RTOALGORITHM, 1); |
| 1382 | TCP_ADD_STATS(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); |
| 1383 | TCP_ADD_STATS(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); |
| 1384 | TCP_ADD_STATS(net, TCP_MIB_MAXCONN, -1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1385 | } |
| 1386 | |
Ilpo Järvinen | 5af4ec2 | 2007-09-20 11:30:48 -0700 | [diff] [blame] | 1387 | /* from STCP */ |
Ilpo Järvinen | ef9da47 | 2008-09-20 21:25:15 -0700 | [diff] [blame] | 1388 | static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp) |
David S. Miller | 0800f17 | 2007-09-20 11:40:37 -0700 | [diff] [blame] | 1389 | { |
Stephen Hemminger | 6a438bb | 2005-11-10 17:14:59 -0800 | [diff] [blame] | 1390 | tp->lost_skb_hint = NULL; |
Ilpo Järvinen | ef9da47 | 2008-09-20 21:25:15 -0700 | [diff] [blame] | 1391 | } |
| 1392 | |
| 1393 | static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) |
| 1394 | { |
| 1395 | tcp_clear_retrans_hints_partial(tp); |
Stephen Hemminger | 6a438bb | 2005-11-10 17:14:59 -0800 | [diff] [blame] | 1396 | tp->retransmit_skb_hint = NULL; |
Ilpo Järvinen | b768920 | 2007-09-20 11:37:19 -0700 | [diff] [blame] | 1397 | } |
| 1398 | |
Eric Dumazet | a915da9b | 2012-01-31 05:18:33 +0000 | [diff] [blame] | 1399 | union tcp_md5_addr { |
| 1400 | struct in_addr a4; |
| 1401 | #if IS_ENABLED(CONFIG_IPV6) |
| 1402 | struct in6_addr a6; |
| 1403 | #endif |
| 1404 | }; |
| 1405 | |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1406 | /* - key database */ |
| 1407 | struct tcp_md5sig_key { |
Eric Dumazet | a915da9b | 2012-01-31 05:18:33 +0000 | [diff] [blame] | 1408 | struct hlist_node node; |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1409 | u8 keylen; |
Eric Dumazet | a915da9b | 2012-01-31 05:18:33 +0000 | [diff] [blame] | 1410 | u8 family; /* AF_INET or AF_INET6 */ |
| 1411 | union tcp_md5_addr addr; |
| 1412 | u8 key[TCP_MD5SIG_MAXKEYLEN]; |
| 1413 | struct rcu_head rcu; |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1414 | }; |
| 1415 | |
| 1416 | /* - sock block */ |
| 1417 | struct tcp_md5sig_info { |
Eric Dumazet | a915da9b | 2012-01-31 05:18:33 +0000 | [diff] [blame] | 1418 | struct hlist_head head; |
Eric Dumazet | a8afca0 | 2012-01-31 18:45:40 +0000 | [diff] [blame] | 1419 | struct rcu_head rcu; |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1420 | }; |
| 1421 | |
| 1422 | /* - pseudo header */ |
| 1423 | struct tcp4_pseudohdr { |
| 1424 | __be32 saddr; |
| 1425 | __be32 daddr; |
| 1426 | __u8 pad; |
| 1427 | __u8 protocol; |
| 1428 | __be16 len; |
| 1429 | }; |
| 1430 | |
| 1431 | struct tcp6_pseudohdr { |
| 1432 | struct in6_addr saddr; |
| 1433 | struct in6_addr daddr; |
| 1434 | __be32 len; |
| 1435 | __be32 protocol; /* including padding */ |
| 1436 | }; |
| 1437 | |
| 1438 | union tcp_md5sum_block { |
| 1439 | struct tcp4_pseudohdr ip4; |
Eric Dumazet | dfd56b8 | 2011-12-10 09:48:31 +0000 | [diff] [blame] | 1440 | #if IS_ENABLED(CONFIG_IPV6) |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1441 | struct tcp6_pseudohdr ip6; |
| 1442 | #endif |
| 1443 | }; |
| 1444 | |
| 1445 | /* - pool: digest algorithm, hash description and scratch buffer */ |
| 1446 | struct tcp_md5sig_pool { |
Herbert Xu | cf80e0e | 2016-01-24 21:20:23 +0800 | [diff] [blame] | 1447 | struct ahash_request *md5_req; |
Eric Dumazet | 19689e3 | 2016-06-27 18:51:53 +0200 | [diff] [blame] | 1448 | void *scratch; |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1449 | }; |
| 1450 | |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1451 | /* - functions */ |
Eric Dumazet | 39f8e58 | 2015-03-24 15:58:55 -0700 | [diff] [blame] | 1452 | int tcp_v4_md5_hash_skb(char *md5_hash, const struct tcp_md5sig_key *key, |
| 1453 | const struct sock *sk, const struct sk_buff *skb); |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1454 | int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr, |
| 1455 | int family, const u8 *newkey, u8 newkeylen, gfp_t gfp); |
| 1456 | int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr, |
| 1457 | int family); |
Eric Dumazet | b83e3de | 2015-09-25 07:39:15 -0700 | [diff] [blame] | 1458 | struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, |
Eric Dumazet | fd3a154 | 2015-03-24 15:58:56 -0700 | [diff] [blame] | 1459 | const struct sock *addr_sk); |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1460 | |
YOSHIFUJI Hideaki | 9501f97 | 2008-04-18 12:45:16 +0900 | [diff] [blame] | 1461 | #ifdef CONFIG_TCP_MD5SIG |
Eric Dumazet | b83e3de | 2015-09-25 07:39:15 -0700 | [diff] [blame] | 1462 | struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk, |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1463 | const union tcp_md5_addr *addr, |
| 1464 | int family); |
Eric Dumazet | a915da9b | 2012-01-31 05:18:33 +0000 | [diff] [blame] | 1465 | #define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key) |
YOSHIFUJI Hideaki | 9501f97 | 2008-04-18 12:45:16 +0900 | [diff] [blame] | 1466 | #else |
Eric Dumazet | b83e3de | 2015-09-25 07:39:15 -0700 | [diff] [blame] | 1467 | static inline struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk, |
Eric Dumazet | a915da9b | 2012-01-31 05:18:33 +0000 | [diff] [blame] | 1468 | const union tcp_md5_addr *addr, |
| 1469 | int family) |
| 1470 | { |
| 1471 | return NULL; |
| 1472 | } |
YOSHIFUJI Hideaki | 9501f97 | 2008-04-18 12:45:16 +0900 | [diff] [blame] | 1473 | #define tcp_twsk_md5_key(twsk) NULL |
| 1474 | #endif |
| 1475 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1476 | bool tcp_alloc_md5sig_pool(void); |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1477 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1478 | struct tcp_md5sig_pool *tcp_get_md5sig_pool(void); |
Eric Dumazet | 71cea17 | 2013-05-20 06:52:26 +0000 | [diff] [blame] | 1479 | static inline void tcp_put_md5sig_pool(void) |
| 1480 | { |
| 1481 | local_bh_enable(); |
| 1482 | } |
Eric Dumazet | 35790c0 | 2010-05-16 00:34:04 -0700 | [diff] [blame] | 1483 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1484 | int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, const struct sk_buff *, |
| 1485 | unsigned int header_len); |
| 1486 | int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, |
| 1487 | const struct tcp_md5sig_key *key); |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1488 | |
Jerry Chu | 1046716 | 2012-08-31 12:29:11 +0000 | [diff] [blame] | 1489 | /* From tcp_fastopen.c */ |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1490 | void tcp_fastopen_cache_get(struct sock *sk, u16 *mss, |
| 1491 | struct tcp_fastopen_cookie *cookie, int *syn_loss, |
| 1492 | unsigned long *last_syn_loss); |
| 1493 | void tcp_fastopen_cache_set(struct sock *sk, u16 mss, |
Daniel Lee | 2646c83 | 2015-04-06 14:37:27 -0700 | [diff] [blame] | 1494 | struct tcp_fastopen_cookie *cookie, bool syn_lost, |
| 1495 | u16 try_exp); |
Yuchung Cheng | 783237e | 2012-07-19 06:43:07 +0000 | [diff] [blame] | 1496 | struct tcp_fastopen_request { |
| 1497 | /* Fast Open cookie. Size 0 means a cookie request */ |
| 1498 | struct tcp_fastopen_cookie cookie; |
| 1499 | struct msghdr *data; /* data in MSG_FASTOPEN */ |
Eric Dumazet | f5ddcbb | 2014-02-20 10:09:18 -0800 | [diff] [blame] | 1500 | size_t size; |
| 1501 | int copied; /* queued in tcp_connect() */ |
Yuchung Cheng | 783237e | 2012-07-19 06:43:07 +0000 | [diff] [blame] | 1502 | }; |
Yuchung Cheng | 783237e | 2012-07-19 06:43:07 +0000 | [diff] [blame] | 1503 | void tcp_free_fastopen_req(struct tcp_sock *tp); |
| 1504 | |
Jerry Chu | 1046716 | 2012-08-31 12:29:11 +0000 | [diff] [blame] | 1505 | extern struct tcp_fastopen_context __rcu *tcp_fastopen_ctx; |
| 1506 | int tcp_fastopen_reset_cipher(void *key, unsigned int len); |
Eric Dumazet | 61d2bca | 2016-02-01 21:03:07 -0800 | [diff] [blame] | 1507 | void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb); |
Eric Dumazet | 7c85af8 | 2015-09-24 17:16:05 -0700 | [diff] [blame] | 1508 | struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, |
| 1509 | struct request_sock *req, |
| 1510 | struct tcp_fastopen_cookie *foc, |
| 1511 | struct dst_entry *dst); |
Hannes Frederic Sowa | 222e83d | 2013-10-19 21:48:58 +0200 | [diff] [blame] | 1512 | void tcp_fastopen_init_key_once(bool publish); |
Jerry Chu | 1046716 | 2012-08-31 12:29:11 +0000 | [diff] [blame] | 1513 | #define TCP_FASTOPEN_KEY_LENGTH 16 |
| 1514 | |
| 1515 | /* Fastopen key context */ |
| 1516 | struct tcp_fastopen_context { |
Eric Dumazet | 7ae8639 | 2013-06-25 01:21:06 -0700 | [diff] [blame] | 1517 | struct crypto_cipher *tfm; |
| 1518 | __u8 key[TCP_FASTOPEN_KEY_LENGTH]; |
| 1519 | struct rcu_head rcu; |
Jerry Chu | 1046716 | 2012-08-31 12:29:11 +0000 | [diff] [blame] | 1520 | }; |
| 1521 | |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1522 | /* write queue abstraction */ |
| 1523 | static inline void tcp_write_queue_purge(struct sock *sk) |
| 1524 | { |
| 1525 | struct sk_buff *skb; |
| 1526 | |
| 1527 | while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) |
Hideo Aoki | 3ab224b | 2007-12-31 00:11:19 -0800 | [diff] [blame] | 1528 | sk_wmem_free_skb(sk, skb); |
| 1529 | sk_mem_reclaim(sk); |
Ilpo Järvinen | 8818a9d | 2009-12-02 22:24:02 -0800 | [diff] [blame] | 1530 | tcp_clear_all_retrans_hints(tcp_sk(sk)); |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1531 | } |
| 1532 | |
Eric Dumazet | cf533ea | 2011-10-21 05:22:42 -0400 | [diff] [blame] | 1533 | static inline struct sk_buff *tcp_write_queue_head(const struct sock *sk) |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1534 | { |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1535 | return skb_peek(&sk->sk_write_queue); |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1536 | } |
| 1537 | |
Eric Dumazet | cf533ea | 2011-10-21 05:22:42 -0400 | [diff] [blame] | 1538 | static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk) |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1539 | { |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1540 | return skb_peek_tail(&sk->sk_write_queue); |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1541 | } |
| 1542 | |
Eric Dumazet | cf533ea | 2011-10-21 05:22:42 -0400 | [diff] [blame] | 1543 | static inline struct sk_buff *tcp_write_queue_next(const struct sock *sk, |
| 1544 | const struct sk_buff *skb) |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1545 | { |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1546 | return skb_queue_next(&sk->sk_write_queue, skb); |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1547 | } |
| 1548 | |
Eric Dumazet | cf533ea | 2011-10-21 05:22:42 -0400 | [diff] [blame] | 1549 | static inline struct sk_buff *tcp_write_queue_prev(const struct sock *sk, |
| 1550 | const struct sk_buff *skb) |
Ilpo Järvinen | 832d11c | 2008-11-24 21:20:15 -0800 | [diff] [blame] | 1551 | { |
| 1552 | return skb_queue_prev(&sk->sk_write_queue, skb); |
| 1553 | } |
| 1554 | |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1555 | #define tcp_for_write_queue(skb, sk) \ |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1556 | skb_queue_walk(&(sk)->sk_write_queue, skb) |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1557 | |
| 1558 | #define tcp_for_write_queue_from(skb, sk) \ |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1559 | skb_queue_walk_from(&(sk)->sk_write_queue, skb) |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1560 | |
Ilpo Järvinen | 234b686 | 2007-12-02 00:48:02 +0200 | [diff] [blame] | 1561 | #define tcp_for_write_queue_from_safe(skb, tmp, sk) \ |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1562 | skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) |
Ilpo Järvinen | 234b686 | 2007-12-02 00:48:02 +0200 | [diff] [blame] | 1563 | |
Eric Dumazet | cf533ea | 2011-10-21 05:22:42 -0400 | [diff] [blame] | 1564 | static inline struct sk_buff *tcp_send_head(const struct sock *sk) |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1565 | { |
| 1566 | return sk->sk_send_head; |
| 1567 | } |
| 1568 | |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1569 | static inline bool tcp_skb_is_last(const struct sock *sk, |
| 1570 | const struct sk_buff *skb) |
| 1571 | { |
| 1572 | return skb_queue_is_last(&sk->sk_write_queue, skb); |
| 1573 | } |
| 1574 | |
Eric Dumazet | cf533ea | 2011-10-21 05:22:42 -0400 | [diff] [blame] | 1575 | static inline void tcp_advance_send_head(struct sock *sk, const struct sk_buff *skb) |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1576 | { |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1577 | if (tcp_skb_is_last(sk, skb)) |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1578 | sk->sk_send_head = NULL; |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1579 | else |
| 1580 | sk->sk_send_head = tcp_write_queue_next(sk, skb); |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1581 | } |
| 1582 | |
| 1583 | static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked) |
| 1584 | { |
| 1585 | if (sk->sk_send_head == skb_unlinked) |
| 1586 | sk->sk_send_head = NULL; |
Eric Dumazet | bb1fcec | 2016-08-17 05:56:26 -0700 | [diff] [blame] | 1587 | if (tcp_sk(sk)->highest_sack == skb_unlinked) |
| 1588 | tcp_sk(sk)->highest_sack = NULL; |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1589 | } |
| 1590 | |
| 1591 | static inline void tcp_init_send_head(struct sock *sk) |
| 1592 | { |
| 1593 | sk->sk_send_head = NULL; |
| 1594 | } |
| 1595 | |
| 1596 | static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) |
| 1597 | { |
| 1598 | __skb_queue_tail(&sk->sk_write_queue, skb); |
| 1599 | } |
| 1600 | |
| 1601 | static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) |
| 1602 | { |
| 1603 | __tcp_add_write_queue_tail(sk, skb); |
| 1604 | |
| 1605 | /* Queue it, remembering where we must start sending. */ |
Ilpo Järvinen | 6859d49 | 2007-12-02 00:48:06 +0200 | [diff] [blame] | 1606 | if (sk->sk_send_head == NULL) { |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1607 | sk->sk_send_head = skb; |
Ilpo Järvinen | 6859d49 | 2007-12-02 00:48:06 +0200 | [diff] [blame] | 1608 | |
| 1609 | if (tcp_sk(sk)->highest_sack == NULL) |
| 1610 | tcp_sk(sk)->highest_sack = skb; |
| 1611 | } |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1612 | } |
| 1613 | |
| 1614 | static inline void __tcp_add_write_queue_head(struct sock *sk, struct sk_buff *skb) |
| 1615 | { |
| 1616 | __skb_queue_head(&sk->sk_write_queue, skb); |
| 1617 | } |
| 1618 | |
| 1619 | /* Insert buff after skb on the write queue of sk. */ |
| 1620 | static inline void tcp_insert_write_queue_after(struct sk_buff *skb, |
| 1621 | struct sk_buff *buff, |
| 1622 | struct sock *sk) |
| 1623 | { |
Gerrit Renker | 7de6c03 | 2008-04-14 00:05:09 -0700 | [diff] [blame] | 1624 | __skb_queue_after(&sk->sk_write_queue, skb, buff); |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1625 | } |
| 1626 | |
David S. Miller | 43f59c8 | 2008-09-21 21:28:51 -0700 | [diff] [blame] | 1627 | /* Insert new before skb on the write queue of sk. */ |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1628 | static inline void tcp_insert_write_queue_before(struct sk_buff *new, |
| 1629 | struct sk_buff *skb, |
| 1630 | struct sock *sk) |
| 1631 | { |
David S. Miller | 43f59c8 | 2008-09-21 21:28:51 -0700 | [diff] [blame] | 1632 | __skb_queue_before(&sk->sk_write_queue, skb, new); |
Ilpo Järvinen | 6e42141 | 2007-11-19 23:24:09 -0800 | [diff] [blame] | 1633 | |
| 1634 | if (sk->sk_send_head == skb) |
| 1635 | sk->sk_send_head = new; |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1636 | } |
| 1637 | |
| 1638 | static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk) |
| 1639 | { |
| 1640 | __skb_unlink(skb, &sk->sk_write_queue); |
| 1641 | } |
| 1642 | |
Eric Dumazet | a2a385d | 2012-05-16 23:15:34 +0000 | [diff] [blame] | 1643 | static inline bool tcp_write_queue_empty(struct sock *sk) |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1644 | { |
| 1645 | return skb_queue_empty(&sk->sk_write_queue); |
| 1646 | } |
| 1647 | |
Krishna Kumar | 12d50c4 | 2009-12-08 22:26:13 +0000 | [diff] [blame] | 1648 | static inline void tcp_push_pending_frames(struct sock *sk) |
| 1649 | { |
| 1650 | if (tcp_send_head(sk)) { |
| 1651 | struct tcp_sock *tp = tcp_sk(sk); |
| 1652 | |
| 1653 | __tcp_push_pending_frames(sk, tcp_current_mss(sk), tp->nonagle); |
| 1654 | } |
| 1655 | } |
| 1656 | |
Neal Cardwell | ecb9719 | 2012-02-27 17:52:52 -0500 | [diff] [blame] | 1657 | /* Start sequence of the skb just after the highest skb with SACKed |
| 1658 | * bit, valid only if sacked_out > 0 or when the caller has ensured |
| 1659 | * validity by itself. |
Ilpo Järvinen | a47e5a9 | 2007-11-15 19:41:46 -0800 | [diff] [blame] | 1660 | */ |
| 1661 | static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp) |
| 1662 | { |
| 1663 | if (!tp->sacked_out) |
| 1664 | return tp->snd_una; |
Ilpo Järvinen | 6859d49 | 2007-12-02 00:48:06 +0200 | [diff] [blame] | 1665 | |
| 1666 | if (tp->highest_sack == NULL) |
| 1667 | return tp->snd_nxt; |
| 1668 | |
Ilpo Järvinen | a47e5a9 | 2007-11-15 19:41:46 -0800 | [diff] [blame] | 1669 | return TCP_SKB_CB(tp->highest_sack)->seq; |
| 1670 | } |
| 1671 | |
Ilpo Järvinen | 6859d49 | 2007-12-02 00:48:06 +0200 | [diff] [blame] | 1672 | static inline void tcp_advance_highest_sack(struct sock *sk, struct sk_buff *skb) |
| 1673 | { |
| 1674 | tcp_sk(sk)->highest_sack = tcp_skb_is_last(sk, skb) ? NULL : |
| 1675 | tcp_write_queue_next(sk, skb); |
| 1676 | } |
| 1677 | |
| 1678 | static inline struct sk_buff *tcp_highest_sack(struct sock *sk) |
| 1679 | { |
| 1680 | return tcp_sk(sk)->highest_sack; |
| 1681 | } |
| 1682 | |
| 1683 | static inline void tcp_highest_sack_reset(struct sock *sk) |
| 1684 | { |
| 1685 | tcp_sk(sk)->highest_sack = tcp_write_queue_head(sk); |
| 1686 | } |
| 1687 | |
Eric Dumazet | e12c42c | 2017-10-30 23:08:20 -0700 | [diff] [blame] | 1688 | /* Called when old skb is about to be deleted and replaced by new skb */ |
| 1689 | static inline void tcp_highest_sack_replace(struct sock *sk, |
Ilpo Järvinen | 6859d49 | 2007-12-02 00:48:06 +0200 | [diff] [blame] | 1690 | struct sk_buff *old, |
| 1691 | struct sk_buff *new) |
| 1692 | { |
Eric Dumazet | e12c42c | 2017-10-30 23:08:20 -0700 | [diff] [blame] | 1693 | if (old == tcp_highest_sack(sk)) |
Ilpo Järvinen | 6859d49 | 2007-12-02 00:48:06 +0200 | [diff] [blame] | 1694 | tcp_sk(sk)->highest_sack = new; |
| 1695 | } |
| 1696 | |
Florian Westphal | b1f0a0e | 2015-12-21 21:29:24 +0100 | [diff] [blame] | 1697 | /* This helper checks if socket has IP_TRANSPARENT set */ |
| 1698 | static inline bool inet_sk_transparent(const struct sock *sk) |
| 1699 | { |
| 1700 | switch (sk->sk_state) { |
| 1701 | case TCP_TIME_WAIT: |
| 1702 | return inet_twsk(sk)->tw_transparent; |
| 1703 | case TCP_NEW_SYN_RECV: |
| 1704 | return inet_rsk(inet_reqsk(sk))->no_srccheck; |
| 1705 | } |
| 1706 | return inet_sk(sk)->transparent; |
| 1707 | } |
| 1708 | |
Andreas Petlund | 5aa4b32 | 2010-02-18 02:45:45 +0000 | [diff] [blame] | 1709 | /* Determines whether this is a thin stream (which may suffer from |
| 1710 | * increased latency). Used to trigger latency-reducing mechanisms. |
| 1711 | */ |
Eric Dumazet | a2a385d | 2012-05-16 23:15:34 +0000 | [diff] [blame] | 1712 | static inline bool tcp_stream_is_thin(struct tcp_sock *tp) |
Andreas Petlund | 5aa4b32 | 2010-02-18 02:45:45 +0000 | [diff] [blame] | 1713 | { |
| 1714 | return tp->packets_out < 4 && !tcp_in_initial_slowstart(tp); |
| 1715 | } |
| 1716 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1717 | /* /proc */ |
| 1718 | enum tcp_seq_states { |
| 1719 | TCP_SEQ_STATE_LISTENING, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1720 | TCP_SEQ_STATE_ESTABLISHED, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1721 | }; |
| 1722 | |
Arjan van de Ven | 73cb88e | 2011-10-30 06:46:30 +0000 | [diff] [blame] | 1723 | int tcp_seq_open(struct inode *inode, struct file *file); |
| 1724 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1725 | struct tcp_seq_afinfo { |
Arjan van de Ven | 73cb88e | 2011-10-30 06:46:30 +0000 | [diff] [blame] | 1726 | char *name; |
| 1727 | sa_family_t family; |
| 1728 | const struct file_operations *seq_fops; |
| 1729 | struct seq_operations seq_ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1730 | }; |
| 1731 | |
| 1732 | struct tcp_iter_state { |
Denis V. Lunev | a4146b1 | 2008-04-13 22:11:14 -0700 | [diff] [blame] | 1733 | struct seq_net_private p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1734 | sa_family_t family; |
| 1735 | enum tcp_seq_states state; |
| 1736 | struct sock *syn_wait_sk; |
Eric W. Biederman | a7cb5a4 | 2012-05-24 01:10:10 -0600 | [diff] [blame] | 1737 | int bucket, offset, sbucket, num; |
Tom Herbert | a8b690f | 2010-06-07 00:43:42 -0700 | [diff] [blame] | 1738 | loff_t last_pos; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1739 | }; |
| 1740 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1741 | int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo); |
| 1742 | void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1743 | |
Arnaldo Carvalho de Melo | 2038073 | 2005-08-16 02:18:02 -0300 | [diff] [blame] | 1744 | extern struct request_sock_ops tcp_request_sock_ops; |
Glenn Griffin | c6aefaf | 2008-02-07 21:49:26 -0800 | [diff] [blame] | 1745 | extern struct request_sock_ops tcp6_request_sock_ops; |
Arnaldo Carvalho de Melo | 2038073 | 2005-08-16 02:18:02 -0300 | [diff] [blame] | 1746 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1747 | void tcp_v4_destroy_sock(struct sock *sk); |
Arnaldo Carvalho de Melo | 2038073 | 2005-08-16 02:18:02 -0300 | [diff] [blame] | 1748 | |
Eric Dumazet | 28be6e0 | 2013-10-18 10:36:17 -0700 | [diff] [blame] | 1749 | struct sk_buff *tcp_gso_segment(struct sk_buff *skb, |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1750 | netdev_features_t features); |
| 1751 | struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb); |
| 1752 | int tcp_gro_complete(struct sk_buff *skb); |
Daniel Borkmann | 28850dc | 2013-06-07 05:11:46 +0000 | [diff] [blame] | 1753 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1754 | void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr, __be32 daddr); |
Herbert Xu | f4c50d9 | 2006-06-22 03:02:40 -0700 | [diff] [blame] | 1755 | |
Eric Dumazet | c9bee3b7 | 2013-07-22 20:27:07 -0700 | [diff] [blame] | 1756 | static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp) |
| 1757 | { |
Nikolay Borisov | 4979f2d | 2016-02-03 09:46:57 +0200 | [diff] [blame] | 1758 | struct net *net = sock_net((struct sock *)tp); |
| 1759 | return tp->notsent_lowat ?: net->ipv4.sysctl_tcp_notsent_lowat; |
Eric Dumazet | c9bee3b7 | 2013-07-22 20:27:07 -0700 | [diff] [blame] | 1760 | } |
| 1761 | |
| 1762 | static inline bool tcp_stream_memory_free(const struct sock *sk) |
| 1763 | { |
| 1764 | const struct tcp_sock *tp = tcp_sk(sk); |
| 1765 | u32 notsent_bytes = tp->write_seq - tp->snd_nxt; |
| 1766 | |
| 1767 | return notsent_bytes < tcp_notsent_lowat(tp); |
| 1768 | } |
| 1769 | |
Arnaldo Carvalho de Melo | 2038073 | 2005-08-16 02:18:02 -0300 | [diff] [blame] | 1770 | #ifdef CONFIG_PROC_FS |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1771 | int tcp4_proc_init(void); |
| 1772 | void tcp4_proc_exit(void); |
Arnaldo Carvalho de Melo | 2038073 | 2005-08-16 02:18:02 -0300 | [diff] [blame] | 1773 | #endif |
| 1774 | |
Eric Dumazet | ea3bea3 | 2015-09-25 07:39:23 -0700 | [diff] [blame] | 1775 | int tcp_rtx_synack(const struct sock *sk, struct request_sock *req); |
Octavian Purdila | 1fb6f15 | 2014-06-25 17:10:02 +0300 | [diff] [blame] | 1776 | int tcp_conn_request(struct request_sock_ops *rsk_ops, |
| 1777 | const struct tcp_request_sock_ops *af_ops, |
| 1778 | struct sock *sk, struct sk_buff *skb); |
Octavian Purdila | 5db92c9 | 2014-06-25 17:09:59 +0300 | [diff] [blame] | 1779 | |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1780 | /* TCP af-specific functions */ |
| 1781 | struct tcp_sock_af_ops { |
| 1782 | #ifdef CONFIG_TCP_MD5SIG |
Eric Dumazet | b83e3de | 2015-09-25 07:39:15 -0700 | [diff] [blame] | 1783 | struct tcp_md5sig_key *(*md5_lookup) (const struct sock *sk, |
Eric Dumazet | fd3a154 | 2015-03-24 15:58:56 -0700 | [diff] [blame] | 1784 | const struct sock *addr_sk); |
Eric Dumazet | 39f8e58 | 2015-03-24 15:58:55 -0700 | [diff] [blame] | 1785 | int (*calc_md5_hash)(char *location, |
| 1786 | const struct tcp_md5sig_key *md5, |
| 1787 | const struct sock *sk, |
| 1788 | const struct sk_buff *skb); |
| 1789 | int (*md5_parse)(struct sock *sk, |
| 1790 | char __user *optval, |
| 1791 | int optlen); |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1792 | #endif |
| 1793 | }; |
| 1794 | |
| 1795 | struct tcp_request_sock_ops { |
Octavian Purdila | 2aec4a2 | 2014-06-25 17:10:00 +0300 | [diff] [blame] | 1796 | u16 mss_clamp; |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1797 | #ifdef CONFIG_TCP_MD5SIG |
Eric Dumazet | b83e3de | 2015-09-25 07:39:15 -0700 | [diff] [blame] | 1798 | struct tcp_md5sig_key *(*req_md5_lookup)(const struct sock *sk, |
Eric Dumazet | fd3a154 | 2015-03-24 15:58:56 -0700 | [diff] [blame] | 1799 | const struct sock *addr_sk); |
Eric Dumazet | 39f8e58 | 2015-03-24 15:58:55 -0700 | [diff] [blame] | 1800 | int (*calc_md5_hash) (char *location, |
| 1801 | const struct tcp_md5sig_key *md5, |
| 1802 | const struct sock *sk, |
| 1803 | const struct sk_buff *skb); |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1804 | #endif |
Eric Dumazet | b40cf18 | 2015-09-25 07:39:08 -0700 | [diff] [blame] | 1805 | void (*init_req)(struct request_sock *req, |
| 1806 | const struct sock *sk_listener, |
Octavian Purdila | 16bea70 | 2014-06-25 17:09:53 +0300 | [diff] [blame] | 1807 | struct sk_buff *skb); |
Octavian Purdila | fb7b37a | 2014-06-25 17:09:54 +0300 | [diff] [blame] | 1808 | #ifdef CONFIG_SYN_COOKIES |
Eric Dumazet | 3f684b4 | 2015-09-29 07:42:49 -0700 | [diff] [blame] | 1809 | __u32 (*cookie_init_seq)(const struct sk_buff *skb, |
Octavian Purdila | fb7b37a | 2014-06-25 17:09:54 +0300 | [diff] [blame] | 1810 | __u16 *mss); |
| 1811 | #endif |
Eric Dumazet | f964629 | 2015-09-29 07:42:50 -0700 | [diff] [blame] | 1812 | struct dst_entry *(*route_req)(const struct sock *sk, struct flowi *fl, |
Octavian Purdila | d94e041 | 2014-06-25 17:09:55 +0300 | [diff] [blame] | 1813 | const struct request_sock *req, |
| 1814 | bool *strict); |
Octavian Purdila | 936b8bd | 2014-06-25 17:09:57 +0300 | [diff] [blame] | 1815 | __u32 (*init_seq)(const struct sk_buff *skb); |
Eric Dumazet | 0f935dbe | 2015-09-25 07:39:21 -0700 | [diff] [blame] | 1816 | int (*send_synack)(const struct sock *sk, struct dst_entry *dst, |
Octavian Purdila | d6274bd | 2014-06-25 17:09:58 +0300 | [diff] [blame] | 1817 | struct flowi *fl, struct request_sock *req, |
Eric Dumazet | dc6ef6b | 2015-10-16 13:00:01 -0700 | [diff] [blame] | 1818 | struct tcp_fastopen_cookie *foc, |
Eric Dumazet | b3d0514 | 2016-04-13 22:05:39 -0700 | [diff] [blame] | 1819 | enum tcp_synack_type synack_type); |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1820 | }; |
| 1821 | |
Octavian Purdila | fb7b37a | 2014-06-25 17:09:54 +0300 | [diff] [blame] | 1822 | #ifdef CONFIG_SYN_COOKIES |
| 1823 | static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, |
Eric Dumazet | 3f684b4 | 2015-09-29 07:42:49 -0700 | [diff] [blame] | 1824 | const struct sock *sk, struct sk_buff *skb, |
Octavian Purdila | fb7b37a | 2014-06-25 17:09:54 +0300 | [diff] [blame] | 1825 | __u16 *mss) |
| 1826 | { |
Eric Dumazet | 3f684b4 | 2015-09-29 07:42:49 -0700 | [diff] [blame] | 1827 | tcp_synq_overflow(sk); |
Eric Dumazet | 02a1d6e | 2016-04-27 16:44:39 -0700 | [diff] [blame] | 1828 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESSENT); |
Eric Dumazet | 3f684b4 | 2015-09-29 07:42:49 -0700 | [diff] [blame] | 1829 | return ops->cookie_init_seq(skb, mss); |
Octavian Purdila | fb7b37a | 2014-06-25 17:09:54 +0300 | [diff] [blame] | 1830 | } |
| 1831 | #else |
| 1832 | static inline __u32 cookie_init_sequence(const struct tcp_request_sock_ops *ops, |
Eric Dumazet | 3f684b4 | 2015-09-29 07:42:49 -0700 | [diff] [blame] | 1833 | const struct sock *sk, struct sk_buff *skb, |
Octavian Purdila | fb7b37a | 2014-06-25 17:09:54 +0300 | [diff] [blame] | 1834 | __u16 *mss) |
| 1835 | { |
| 1836 | return 0; |
| 1837 | } |
| 1838 | #endif |
| 1839 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1840 | int tcpv4_offload_init(void); |
Daniel Borkmann | 28850dc | 2013-06-07 05:11:46 +0000 | [diff] [blame] | 1841 | |
Joe Perches | 5c9f302 | 2013-09-23 11:33:32 -0700 | [diff] [blame] | 1842 | void tcp_v4_init(void); |
| 1843 | void tcp_init(void); |
Arnaldo Carvalho de Melo | 2038073 | 2005-08-16 02:18:02 -0300 | [diff] [blame] | 1844 | |
Yuchung Cheng | 659a8ad | 2015-10-16 21:57:46 -0700 | [diff] [blame] | 1845 | /* tcp_recovery.c */ |
| 1846 | |
Yuchung Cheng | 4f41b1c | 2015-10-16 21:57:47 -0700 | [diff] [blame] | 1847 | /* Flags to enable various loss recovery features. See below */ |
| 1848 | extern int sysctl_tcp_recovery; |
| 1849 | |
| 1850 | /* Use TCP RACK to detect (some) tail and retransmit losses */ |
| 1851 | #define TCP_RACK_LOST_RETRANS 0x1 |
| 1852 | |
| 1853 | extern int tcp_rack_mark_lost(struct sock *sk); |
| 1854 | |
Yuchung Cheng | 659a8ad | 2015-10-16 21:57:46 -0700 | [diff] [blame] | 1855 | extern void tcp_rack_advance(struct tcp_sock *tp, |
| 1856 | const struct skb_mstamp *xmit_time, u8 sacked); |
| 1857 | |
Cong Wang | e25f866 | 2014-10-15 14:33:21 -0700 | [diff] [blame] | 1858 | /* |
| 1859 | * Save and compile IPv4 options, return a pointer to it |
| 1860 | */ |
| 1861 | static inline struct ip_options_rcu *tcp_v4_save_options(struct sk_buff *skb) |
| 1862 | { |
| 1863 | const struct ip_options *opt = &TCP_SKB_CB(skb)->header.h4.opt; |
| 1864 | struct ip_options_rcu *dopt = NULL; |
| 1865 | |
Cong Wang | 461b74c | 2014-10-15 14:33:22 -0700 | [diff] [blame] | 1866 | if (opt->optlen) { |
Cong Wang | e25f866 | 2014-10-15 14:33:21 -0700 | [diff] [blame] | 1867 | int opt_size = sizeof(*dopt) + opt->optlen; |
| 1868 | |
| 1869 | dopt = kmalloc(opt_size, GFP_ATOMIC); |
| 1870 | if (dopt && __ip_options_echo(&dopt->opt, skb, opt)) { |
| 1871 | kfree(dopt); |
| 1872 | dopt = NULL; |
| 1873 | } |
| 1874 | } |
| 1875 | return dopt; |
| 1876 | } |
| 1877 | |
Eric Dumazet | 9878196 | 2015-02-03 18:31:53 -0800 | [diff] [blame] | 1878 | /* locally generated TCP pure ACKs have skb->truesize == 2 |
| 1879 | * (check tcp_send_ack() in net/ipv4/tcp_output.c ) |
| 1880 | * This is much faster than dissecting the packet to find out. |
| 1881 | * (Think of GRE encapsulations, IPv4, IPv6, ...) |
| 1882 | */ |
| 1883 | static inline bool skb_is_tcp_pure_ack(const struct sk_buff *skb) |
| 1884 | { |
| 1885 | return skb->truesize == 2; |
| 1886 | } |
| 1887 | |
| 1888 | static inline void skb_set_tcp_pure_ack(struct sk_buff *skb) |
| 1889 | { |
| 1890 | skb->truesize = 2; |
| 1891 | } |
| 1892 | |
Tom Herbert | 473bd23 | 2016-03-07 14:11:05 -0800 | [diff] [blame] | 1893 | static inline int tcp_inq(struct sock *sk) |
| 1894 | { |
| 1895 | struct tcp_sock *tp = tcp_sk(sk); |
| 1896 | int answ; |
| 1897 | |
| 1898 | if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) { |
| 1899 | answ = 0; |
| 1900 | } else if (sock_flag(sk, SOCK_URGINLINE) || |
| 1901 | !tp->urg_data || |
| 1902 | before(tp->urg_seq, tp->copied_seq) || |
| 1903 | !before(tp->urg_seq, tp->rcv_nxt)) { |
| 1904 | |
| 1905 | answ = tp->rcv_nxt - tp->copied_seq; |
| 1906 | |
| 1907 | /* Subtract 1, if FIN was received */ |
| 1908 | if (answ && sock_flag(sk, SOCK_DONE)) |
| 1909 | answ--; |
| 1910 | } else { |
| 1911 | answ = tp->urg_seq - tp->copied_seq; |
| 1912 | } |
| 1913 | |
| 1914 | return answ; |
| 1915 | } |
| 1916 | |
Tom Herbert | 3203558 | 2016-08-28 14:43:18 -0700 | [diff] [blame] | 1917 | int tcp_peek_len(struct socket *sock); |
| 1918 | |
Martin KaFai Lau | a44d6ea | 2016-03-14 10:52:15 -0700 | [diff] [blame] | 1919 | static inline void tcp_segs_in(struct tcp_sock *tp, const struct sk_buff *skb) |
| 1920 | { |
| 1921 | u16 segs_in; |
| 1922 | |
| 1923 | segs_in = max_t(u16, 1, skb_shinfo(skb)->gso_segs); |
| 1924 | tp->segs_in += segs_in; |
| 1925 | if (skb->len > tcp_hdrlen(skb)) |
| 1926 | tp->data_segs_in += segs_in; |
| 1927 | } |
| 1928 | |
Eric Dumazet | 9caad86 | 2016-04-01 08:52:20 -0700 | [diff] [blame] | 1929 | /* |
| 1930 | * TCP listen path runs lockless. |
| 1931 | * We forced "struct sock" to be const qualified to make sure |
| 1932 | * we don't modify one of its field by mistake. |
| 1933 | * Here, we increment sk_drops which is an atomic_t, so we can safely |
| 1934 | * make sock writable again. |
| 1935 | */ |
| 1936 | static inline void tcp_listendrop(const struct sock *sk) |
| 1937 | { |
| 1938 | atomic_inc(&((struct sock *)sk)->sk_drops); |
Eric Dumazet | 02a1d6e | 2016-04-27 16:44:39 -0700 | [diff] [blame] | 1939 | __NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENDROPS); |
Eric Dumazet | 9caad86 | 2016-04-01 08:52:20 -0700 | [diff] [blame] | 1940 | } |
| 1941 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1942 | #endif /* _TCP_H */ |