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 | |
| 21 | #define TCP_DEBUG 1 |
| 22 | #define FASTRETRANS_DEBUG 1 |
| 23 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include <linux/list.h> |
| 25 | #include <linux/tcp.h> |
| 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> |
Chris Leech | 97fc2f0 | 2006-05-23 17:55:33 -0700 | [diff] [blame] | 30 | #include <linux/dmaengine.h> |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 31 | #include <linux/crypto.h> |
Glenn Griffin | c6aefaf | 2008-02-07 21:49:26 -0800 | [diff] [blame] | 32 | #include <linux/cryptohash.h> |
William Allen Simpson | 435cf55 | 2009-12-02 18:17:05 +0000 | [diff] [blame] | 33 | #include <linux/kref.h> |
Arnaldo Carvalho de Melo | 3f421ba | 2005-08-09 20:11:08 -0700 | [diff] [blame] | 34 | |
| 35 | #include <net/inet_connection_sock.h> |
Arnaldo Carvalho de Melo | 295ff7e | 2005-08-09 20:44:40 -0700 | [diff] [blame] | 36 | #include <net/inet_timewait_sock.h> |
Arnaldo Carvalho de Melo | 77d8bf9 | 2005-08-09 20:00:51 -0700 | [diff] [blame] | 37 | #include <net/inet_hashtables.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | #include <net/checksum.h> |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 39 | #include <net/request_sock.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | #include <net/sock.h> |
| 41 | #include <net/snmp.h> |
| 42 | #include <net/ip.h> |
Arnaldo Carvalho de Melo | c752f07 | 2005-08-09 20:08:28 -0700 | [diff] [blame] | 43 | #include <net/tcp_states.h> |
Ilpo Järvinen | bdf1ee5 | 2007-05-27 02:04:16 -0700 | [diff] [blame] | 44 | #include <net/inet_ecn.h> |
Satoru SATOH | 0c26689 | 2009-05-04 11:11:01 -0700 | [diff] [blame] | 45 | #include <net/dst.h> |
Arnaldo Carvalho de Melo | c752f07 | 2005-08-09 20:08:28 -0700 | [diff] [blame] | 46 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | #include <linux/seq_file.h> |
| 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; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | extern 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 | |
| 57 | /* |
| 58 | * Never offer a window over 32767 without using window scaling. Some |
| 59 | * poor stacks do signed 16bit maths! |
| 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 */ |
| 67 | #define TCP_BASE_MSS 512 |
| 68 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | /* After receiving this amount of duplicate ACKs fast retransmit starts. */ |
| 70 | #define TCP_FASTRETRANS_THRESH 3 |
| 71 | |
| 72 | /* Maximal reordering. */ |
| 73 | #define TCP_MAX_REORDERING 127 |
| 74 | |
| 75 | /* Maximal number of ACKs sent quickly to accelerate slow-start. */ |
| 76 | #define TCP_MAX_QUICKACKS 16U |
| 77 | |
| 78 | /* urg_data states */ |
| 79 | #define TCP_URG_VALID 0x0100 |
| 80 | #define TCP_URG_NOTYET 0x0200 |
| 81 | #define TCP_URG_READ 0x0400 |
| 82 | |
| 83 | #define TCP_RETR1 3 /* |
| 84 | * This is how many retries it does before it |
| 85 | * tries to figure out if the gateway is |
| 86 | * down. Minimal RFC value is 3; it corresponds |
| 87 | * to ~3sec-8min depending on RTO. |
| 88 | */ |
| 89 | |
| 90 | #define TCP_RETR2 15 /* |
| 91 | * This should take at least |
| 92 | * 90 minutes to time out. |
| 93 | * RFC1122 says that the limit is 100 sec. |
| 94 | * 15 is ~13-30min depending on RTO. |
| 95 | */ |
| 96 | |
| 97 | #define TCP_SYN_RETRIES 5 /* number of times to retry active opening a |
Stephen Hemminger | caa20d9a | 2005-11-10 17:13:47 -0800 | [diff] [blame] | 98 | * connection: ~180sec is RFC minimum */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | |
| 100 | #define TCP_SYNACK_RETRIES 5 /* number of times to retry passive opening a |
Stephen Hemminger | caa20d9a | 2005-11-10 17:13:47 -0800 | [diff] [blame] | 101 | * connection: ~180sec is RFC minimum */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | |
| 103 | |
| 104 | #define TCP_ORPHAN_RETRIES 7 /* number of times to retry on an orphaned |
| 105 | * socket. 7 is ~50sec-16min. |
| 106 | */ |
| 107 | |
| 108 | |
| 109 | #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT |
| 110 | * state, about 60 seconds */ |
| 111 | #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN |
| 112 | /* BSD style FIN_WAIT2 deadlock breaker. |
| 113 | * It used to be 3min, new value is 60sec, |
| 114 | * to combine FIN-WAIT-2 timeout with |
| 115 | * TIME-WAIT timer. |
| 116 | */ |
| 117 | |
| 118 | #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ |
| 119 | #if HZ >= 100 |
| 120 | #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */ |
| 121 | #define TCP_ATO_MIN ((unsigned)(HZ/25)) |
| 122 | #else |
| 123 | #define TCP_DELACK_MIN 4U |
| 124 | #define TCP_ATO_MIN 4U |
| 125 | #endif |
| 126 | #define TCP_RTO_MAX ((unsigned)(120*HZ)) |
| 127 | #define TCP_RTO_MIN ((unsigned)(HZ/5)) |
| 128 | #define TCP_TIMEOUT_INIT ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value */ |
| 129 | |
| 130 | #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes |
| 131 | * for local resources. |
| 132 | */ |
| 133 | |
| 134 | #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ |
| 135 | #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ |
| 136 | #define TCP_KEEPALIVE_INTVL (75*HZ) |
| 137 | |
| 138 | #define MAX_TCP_KEEPIDLE 32767 |
| 139 | #define MAX_TCP_KEEPINTVL 32767 |
| 140 | #define MAX_TCP_KEEPCNT 127 |
| 141 | #define MAX_TCP_SYNCNT 127 |
| 142 | |
| 143 | #define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | |
| 145 | #define TCP_PAWS_24DAYS (60 * 60 * 24 * 24) |
| 146 | #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated |
| 147 | * after this time. It should be equal |
| 148 | * (or greater than) TCP_TIMEWAIT_LEN |
| 149 | * to provide reliability equal to one |
| 150 | * provided by timewait state. |
| 151 | */ |
| 152 | #define TCP_PAWS_WINDOW 1 /* Replay window for per-host |
| 153 | * timestamps. It must be less than |
| 154 | * minimal timewait lifetime. |
| 155 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | /* |
| 157 | * TCP option |
| 158 | */ |
| 159 | |
| 160 | #define TCPOPT_NOP 1 /* Padding */ |
| 161 | #define TCPOPT_EOL 0 /* End of options */ |
| 162 | #define TCPOPT_MSS 2 /* Segment size negotiating */ |
| 163 | #define TCPOPT_WINDOW 3 /* Window scaling */ |
| 164 | #define TCPOPT_SACK_PERM 4 /* SACK Permitted */ |
| 165 | #define TCPOPT_SACK 5 /* SACK Block */ |
| 166 | #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 167 | #define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */ |
William Allen Simpson | 435cf55 | 2009-12-02 18:17:05 +0000 | [diff] [blame] | 168 | #define TCPOPT_COOKIE 253 /* Cookie extension (experimental) */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 169 | |
| 170 | /* |
| 171 | * TCP option lengths |
| 172 | */ |
| 173 | |
| 174 | #define TCPOLEN_MSS 4 |
| 175 | #define TCPOLEN_WINDOW 3 |
| 176 | #define TCPOLEN_SACK_PERM 2 |
| 177 | #define TCPOLEN_TIMESTAMP 10 |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 178 | #define TCPOLEN_MD5SIG 18 |
William Allen Simpson | 435cf55 | 2009-12-02 18:17:05 +0000 | [diff] [blame] | 179 | #define TCPOLEN_COOKIE_BASE 2 /* Cookie-less header extension */ |
| 180 | #define TCPOLEN_COOKIE_PAIR 3 /* Cookie pair header extension */ |
| 181 | #define TCPOLEN_COOKIE_MIN (TCPOLEN_COOKIE_BASE+TCP_COOKIE_MIN) |
| 182 | #define TCPOLEN_COOKIE_MAX (TCPOLEN_COOKIE_BASE+TCP_COOKIE_MAX) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | |
| 184 | /* But this is what stacks really send out. */ |
| 185 | #define TCPOLEN_TSTAMP_ALIGNED 12 |
| 186 | #define TCPOLEN_WSCALE_ALIGNED 4 |
| 187 | #define TCPOLEN_SACKPERM_ALIGNED 4 |
| 188 | #define TCPOLEN_SACK_BASE 2 |
| 189 | #define TCPOLEN_SACK_BASE_ALIGNED 4 |
| 190 | #define TCPOLEN_SACK_PERBLOCK 8 |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 191 | #define TCPOLEN_MD5SIG_ALIGNED 20 |
Adam Langley | 33ad798 | 2008-07-19 00:04:31 -0700 | [diff] [blame] | 192 | #define TCPOLEN_MSS_ALIGNED 4 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 193 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 194 | /* Flags in tp->nonagle */ |
| 195 | #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */ |
| 196 | #define TCP_NAGLE_CORK 2 /* Socket is corked */ |
Stephen Hemminger | caa20d9a | 2005-11-10 17:13:47 -0800 | [diff] [blame] | 197 | #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | |
Andreas Petlund | 36e31b0a | 2010-02-18 02:47:01 +0000 | [diff] [blame] | 199 | /* TCP thin-stream limits */ |
| 200 | #define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */ |
| 201 | |
Arnaldo Carvalho de Melo | 295ff7e | 2005-08-09 20:44:40 -0700 | [diff] [blame] | 202 | extern struct inet_timewait_death_row tcp_death_row; |
| 203 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | /* sysctl variables for tcp */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 205 | extern int sysctl_tcp_timestamps; |
| 206 | extern int sysctl_tcp_window_scaling; |
| 207 | extern int sysctl_tcp_sack; |
| 208 | extern int sysctl_tcp_fin_timeout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | extern int sysctl_tcp_keepalive_time; |
| 210 | extern int sysctl_tcp_keepalive_probes; |
| 211 | extern int sysctl_tcp_keepalive_intvl; |
| 212 | extern int sysctl_tcp_syn_retries; |
| 213 | extern int sysctl_tcp_synack_retries; |
| 214 | extern int sysctl_tcp_retries1; |
| 215 | extern int sysctl_tcp_retries2; |
| 216 | extern int sysctl_tcp_orphan_retries; |
| 217 | extern int sysctl_tcp_syncookies; |
| 218 | extern int sysctl_tcp_retrans_collapse; |
| 219 | extern int sysctl_tcp_stdurg; |
| 220 | extern int sysctl_tcp_rfc1337; |
| 221 | extern int sysctl_tcp_abort_on_overflow; |
| 222 | extern int sysctl_tcp_max_orphans; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | extern int sysctl_tcp_fack; |
| 224 | extern int sysctl_tcp_reordering; |
| 225 | extern int sysctl_tcp_ecn; |
| 226 | extern int sysctl_tcp_dsack; |
| 227 | extern int sysctl_tcp_mem[3]; |
| 228 | extern int sysctl_tcp_wmem[3]; |
| 229 | extern int sysctl_tcp_rmem[3]; |
| 230 | extern int sysctl_tcp_app_win; |
| 231 | extern int sysctl_tcp_adv_win_scale; |
| 232 | extern int sysctl_tcp_tw_reuse; |
| 233 | extern int sysctl_tcp_frto; |
Ilpo Järvinen | 3cfe3ba | 2007-02-27 10:09:49 -0800 | [diff] [blame] | 234 | extern int sysctl_tcp_frto_response; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | extern int sysctl_tcp_low_latency; |
Chris Leech | 9593782 | 2006-05-23 18:02:55 -0700 | [diff] [blame] | 236 | extern int sysctl_tcp_dma_copybreak; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | extern int sysctl_tcp_nometrics_save; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 238 | extern int sysctl_tcp_moderate_rcvbuf; |
| 239 | extern int sysctl_tcp_tso_win_divisor; |
Stephen Hemminger | 9772efb | 2005-11-10 17:09:53 -0800 | [diff] [blame] | 240 | extern int sysctl_tcp_abc; |
John Heffner | 5d424d5 | 2006-03-20 17:53:41 -0800 | [diff] [blame] | 241 | extern int sysctl_tcp_mtu_probing; |
| 242 | extern int sysctl_tcp_base_mss; |
Rick Jones | 15d99e0 | 2006-03-20 22:40:29 -0800 | [diff] [blame] | 243 | extern int sysctl_tcp_workaround_signed_windows; |
David S. Miller | 35089bb | 2006-06-13 22:33:04 -0700 | [diff] [blame] | 244 | extern int sysctl_tcp_slow_start_after_idle; |
John Heffner | 886236c | 2007-03-25 19:21:45 -0700 | [diff] [blame] | 245 | extern int sysctl_tcp_max_ssthresh; |
William Allen Simpson | 519855c | 2009-12-02 18:14:19 +0000 | [diff] [blame] | 246 | extern int sysctl_tcp_cookie_size; |
Andreas Petlund | 36e31b0a | 2010-02-18 02:47:01 +0000 | [diff] [blame] | 247 | extern int sysctl_tcp_thin_linear_timeouts; |
Andreas Petlund | 7e38017 | 2010-02-18 04:48:19 +0000 | [diff] [blame] | 248 | extern int sysctl_tcp_thin_dupack; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | |
| 250 | extern atomic_t tcp_memory_allocated; |
Eric Dumazet | 1748376 | 2008-11-25 21:16:35 -0800 | [diff] [blame] | 251 | extern struct percpu_counter tcp_sockets_allocated; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 252 | extern int tcp_memory_pressure; |
| 253 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 255 | * The next routines deal with comparing 32 bit unsigned ints |
| 256 | * and worry about wraparound (automatic with unsigned arithmetic). |
| 257 | */ |
| 258 | |
| 259 | static inline int before(__u32 seq1, __u32 seq2) |
| 260 | { |
Gerrit Renker | 0d630cc | 2007-01-04 12:25:16 -0800 | [diff] [blame] | 261 | return (__s32)(seq1-seq2) < 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 262 | } |
Gerrit Renker | 9a036b9c | 2006-12-20 10:25:55 -0800 | [diff] [blame] | 263 | #define after(seq2, seq1) before(seq1, seq2) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | |
| 265 | /* is s2<=s1<=s3 ? */ |
| 266 | static inline int between(__u32 seq1, __u32 seq2, __u32 seq3) |
| 267 | { |
| 268 | return seq3 - seq2 >= seq1 - seq2; |
| 269 | } |
| 270 | |
David S. Miller | ad1af0f | 2010-08-25 02:27:49 -0700 | [diff] [blame] | 271 | static inline bool tcp_too_many_orphans(struct sock *sk, int shift) |
Pavel Emelianov | e4fd5da | 2007-05-29 13:19:18 -0700 | [diff] [blame] | 272 | { |
David S. Miller | ad1af0f | 2010-08-25 02:27:49 -0700 | [diff] [blame] | 273 | struct percpu_counter *ocp = sk->sk_prot->orphan_count; |
| 274 | int orphans = percpu_counter_read_positive(ocp); |
| 275 | |
| 276 | if (orphans << shift > sysctl_tcp_max_orphans) { |
| 277 | orphans = percpu_counter_sum_positive(ocp); |
| 278 | if (orphans << shift > sysctl_tcp_max_orphans) |
| 279 | return true; |
| 280 | } |
| 281 | |
| 282 | if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF && |
| 283 | atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2]) |
| 284 | return true; |
| 285 | return false; |
Pavel Emelianov | e4fd5da | 2007-05-29 13:19:18 -0700 | [diff] [blame] | 286 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 287 | |
Florian Westphal | a0f82f6 | 2009-04-19 09:43:48 +0000 | [diff] [blame] | 288 | /* syncookies: remember time of last synqueue overflow */ |
| 289 | static inline void tcp_synq_overflow(struct sock *sk) |
| 290 | { |
| 291 | tcp_sk(sk)->rx_opt.ts_recent_stamp = jiffies; |
| 292 | } |
| 293 | |
| 294 | /* syncookies: no recent synqueue overflow on this listening socket? */ |
| 295 | static inline int tcp_synq_no_recent_overflow(const struct sock *sk) |
| 296 | { |
| 297 | unsigned long last_overflow = tcp_sk(sk)->rx_opt.ts_recent_stamp; |
| 298 | return time_after(jiffies, last_overflow + TCP_TIMEOUT_INIT); |
| 299 | } |
| 300 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | extern struct proto tcp_prot; |
| 302 | |
Pavel Emelyanov | 57ef42d | 2008-07-18 04:02:08 -0700 | [diff] [blame] | 303 | #define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field) |
| 304 | #define TCP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.tcp_statistics, field) |
| 305 | #define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field) |
| 306 | #define TCP_ADD_STATS_USER(net, field, val) SNMP_ADD_STATS_USER((net)->mib.tcp_statistics, field, val) |
Tom Herbert | aa2ea05 | 2010-04-22 07:00:24 +0000 | [diff] [blame] | 307 | #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] | 308 | |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 309 | extern void tcp_v4_err(struct sk_buff *skb, u32); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 311 | extern void tcp_shutdown (struct sock *sk, int how); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 312 | |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 313 | extern int tcp_v4_rcv(struct sk_buff *skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 314 | |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 315 | extern int tcp_v4_remember_stamp(struct sock *sk); |
| 316 | extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw); |
Changli Gao | 7ba4291 | 2010-07-10 20:41:55 +0000 | [diff] [blame] | 317 | extern int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, |
| 318 | size_t size); |
| 319 | extern int tcp_sendpage(struct sock *sk, struct page *page, int offset, |
| 320 | size_t size, int flags); |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 321 | extern int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg); |
| 322 | extern int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb, |
| 323 | struct tcphdr *th, unsigned len); |
| 324 | extern int tcp_rcv_established(struct sock *sk, struct sk_buff *skb, |
| 325 | struct tcphdr *th, unsigned len); |
| 326 | extern void tcp_rcv_space_adjust(struct sock *sk); |
| 327 | extern void tcp_cleanup_rbuf(struct sock *sk, int copied); |
| 328 | extern int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp); |
| 329 | extern void tcp_twsk_destructor(struct sock *sk); |
| 330 | extern ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos, |
| 331 | struct pipe_inode_info *pipe, size_t len, |
| 332 | unsigned int flags); |
Jens Axboe | 9c55e01 | 2007-11-06 23:30:13 -0800 | [diff] [blame] | 333 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 334 | static inline void tcp_dec_quickack_mode(struct sock *sk, |
| 335 | const unsigned int pkts) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 336 | { |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 337 | struct inet_connection_sock *icsk = inet_csk(sk); |
David S. Miller | fc6415bc | 2005-07-05 15:17:45 -0700 | [diff] [blame] | 338 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 339 | if (icsk->icsk_ack.quick) { |
| 340 | if (pkts >= icsk->icsk_ack.quick) { |
| 341 | icsk->icsk_ack.quick = 0; |
David S. Miller | fc6415bc | 2005-07-05 15:17:45 -0700 | [diff] [blame] | 342 | /* Leaving quickack mode we deflate ATO. */ |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 343 | icsk->icsk_ack.ato = TCP_ATO_MIN; |
David S. Miller | fc6415bc | 2005-07-05 15:17:45 -0700 | [diff] [blame] | 344 | } else |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 345 | icsk->icsk_ack.quick -= pkts; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 346 | } |
| 347 | } |
| 348 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 349 | extern void tcp_enter_quickack_mode(struct sock *sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | |
Ilpo Järvinen | bdf1ee5 | 2007-05-27 02:04:16 -0700 | [diff] [blame] | 351 | #define TCP_ECN_OK 1 |
| 352 | #define TCP_ECN_QUEUE_CWR 2 |
| 353 | #define TCP_ECN_DEMAND_CWR 4 |
| 354 | |
| 355 | static __inline__ void |
| 356 | TCP_ECN_create_request(struct request_sock *req, struct tcphdr *th) |
| 357 | { |
| 358 | if (sysctl_tcp_ecn && th->ece && th->cwr) |
| 359 | inet_rsk(req)->ecn_ok = 1; |
| 360 | } |
| 361 | |
Eric Dumazet | fd2c3ef | 2009-11-03 03:26:03 +0000 | [diff] [blame] | 362 | enum tcp_tw_status { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 363 | TCP_TW_SUCCESS = 0, |
| 364 | TCP_TW_RST = 1, |
| 365 | TCP_TW_ACK = 2, |
| 366 | TCP_TW_SYN = 3 |
| 367 | }; |
| 368 | |
| 369 | |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 370 | extern enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, |
| 371 | struct sk_buff *skb, |
| 372 | const struct tcphdr *th); |
| 373 | extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb, |
| 374 | struct request_sock *req, |
| 375 | struct request_sock **prev); |
| 376 | extern int tcp_child_process(struct sock *parent, struct sock *child, |
| 377 | struct sk_buff *skb); |
| 378 | extern int tcp_use_frto(struct sock *sk); |
| 379 | extern void tcp_enter_frto(struct sock *sk); |
| 380 | extern void tcp_enter_loss(struct sock *sk, int how); |
| 381 | extern void tcp_clear_retrans(struct tcp_sock *tp); |
| 382 | extern void tcp_update_metrics(struct sock *sk); |
| 383 | extern void tcp_close(struct sock *sk, long timeout); |
| 384 | extern unsigned int tcp_poll(struct file * file, struct socket *sock, |
| 385 | struct poll_table_struct *wait); |
| 386 | extern int tcp_getsockopt(struct sock *sk, int level, int optname, |
| 387 | char __user *optval, int __user *optlen); |
| 388 | extern int tcp_setsockopt(struct sock *sk, int level, int optname, |
| 389 | char __user *optval, unsigned int optlen); |
| 390 | extern int compat_tcp_getsockopt(struct sock *sk, int level, int optname, |
| 391 | char __user *optval, int __user *optlen); |
| 392 | extern int compat_tcp_setsockopt(struct sock *sk, int level, int optname, |
| 393 | char __user *optval, unsigned int optlen); |
| 394 | extern void tcp_set_keepalive(struct sock *sk, int val); |
| 395 | extern void tcp_syn_ack_timeout(struct sock *sk, struct request_sock *req); |
| 396 | extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, |
| 397 | size_t len, int nonblock, int flags, int *addr_len); |
| 398 | extern void tcp_parse_options(struct sk_buff *skb, |
| 399 | struct tcp_options_received *opt_rx, u8 **hvpp, |
| 400 | int estab); |
| 401 | extern u8 *tcp_parse_md5sig_option(struct tcphdr *th); |
YOSHIFUJI Hideaki | 7d5d552 | 2008-04-17 12:29:53 +0900 | [diff] [blame] | 402 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 403 | /* |
| 404 | * TCP v4 functions exported for the inet6 API |
| 405 | */ |
| 406 | |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 407 | extern void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb); |
| 408 | extern int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb); |
| 409 | extern struct sock * tcp_create_openreq_child(struct sock *sk, |
| 410 | struct request_sock *req, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | struct sk_buff *skb); |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 412 | extern struct sock * tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb, |
| 413 | struct request_sock *req, |
| 414 | struct dst_entry *dst); |
| 415 | extern int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb); |
| 416 | extern int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, |
| 417 | int addr_len); |
| 418 | extern int tcp_connect(struct sock *sk); |
| 419 | extern struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst, |
| 420 | struct request_sock *req, |
| 421 | struct request_values *rvp); |
| 422 | extern int tcp_disconnect(struct sock *sk, int flags); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 424 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 425 | /* From syncookies.c */ |
Florian Westphal | 2051f11 | 2008-03-23 22:21:28 -0700 | [diff] [blame] | 426 | extern __u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb, |
| 428 | struct ip_options *opt); |
| 429 | extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, |
| 430 | __u16 *mss); |
| 431 | |
Florian Westphal | 4dfc281 | 2008-04-10 03:12:40 -0700 | [diff] [blame] | 432 | extern __u32 cookie_init_timestamp(struct request_sock *req); |
Florian Westphal | 172d69e | 2010-06-21 11:48:45 +0000 | [diff] [blame] | 433 | extern bool cookie_check_timestamp(struct tcp_options_received *opt, bool *); |
Florian Westphal | 4dfc281 | 2008-04-10 03:12:40 -0700 | [diff] [blame] | 434 | |
Glenn Griffin | c6aefaf | 2008-02-07 21:49:26 -0800 | [diff] [blame] | 435 | /* From net/ipv6/syncookies.c */ |
| 436 | extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb); |
| 437 | extern __u32 cookie_v6_init_sequence(struct sock *sk, struct sk_buff *skb, |
| 438 | __u16 *mss); |
| 439 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 440 | /* tcp_output.c */ |
| 441 | |
Ilpo Järvinen | 9e412ba | 2007-04-20 22:18:02 -0700 | [diff] [blame] | 442 | extern void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss, |
| 443 | int nonagle); |
| 444 | extern int tcp_may_send_now(struct sock *sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | extern int tcp_retransmit_skb(struct sock *, struct sk_buff *); |
Damian Lukowski | f1ecd5d | 2009-08-26 00:16:31 +0000 | [diff] [blame] | 446 | extern void tcp_retransmit_timer(struct sock *sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 447 | extern void tcp_xmit_retransmit_queue(struct sock *); |
| 448 | extern void tcp_simple_retransmit(struct sock *); |
| 449 | extern int tcp_trim_head(struct sock *, struct sk_buff *, u32); |
David S. Miller | 6475be1 | 2005-09-01 22:47:01 -0700 | [diff] [blame] | 450 | extern int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | |
| 452 | extern void tcp_send_probe0(struct sock *); |
| 453 | extern void tcp_send_partial(struct sock *); |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 454 | extern int tcp_write_wakeup(struct sock *); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | extern void tcp_send_fin(struct sock *sk); |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 456 | extern void tcp_send_active_reset(struct sock *sk, gfp_t priority); |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 457 | extern int tcp_send_synack(struct sock *); |
David S. Miller | c1b4a7e | 2005-07-05 15:24:38 -0700 | [diff] [blame] | 458 | extern void tcp_push_one(struct sock *, unsigned int mss_now); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 459 | extern void tcp_send_ack(struct sock *sk); |
| 460 | extern void tcp_send_delayed_ack(struct sock *sk); |
| 461 | |
David S. Miller | a762a98 | 2005-07-05 15:18:51 -0700 | [diff] [blame] | 462 | /* tcp_input.c */ |
| 463 | extern void tcp_cwnd_application_limited(struct sock *sk); |
| 464 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | /* tcp_timer.c */ |
| 466 | extern void tcp_init_xmit_timers(struct sock *); |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 467 | static inline void tcp_clear_xmit_timers(struct sock *sk) |
| 468 | { |
| 469 | inet_csk_clear_xmit_timers(sk); |
| 470 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 471 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 472 | extern unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); |
Ilpo Järvinen | 0c54b85 | 2009-03-14 14:23:05 +0000 | [diff] [blame] | 473 | extern unsigned int tcp_current_mss(struct sock *sk); |
| 474 | |
| 475 | /* Bound MSS / TSO packet size with the half of the window */ |
| 476 | static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize) |
| 477 | { |
Alexey Kuznetsov | 01f83d6 | 2010-09-15 10:27:52 -0700 | [diff] [blame] | 478 | int cutoff; |
| 479 | |
| 480 | /* When peer uses tiny windows, there is no use in packetizing |
| 481 | * to sub-MSS pieces for the sake of SWS or making sure there |
| 482 | * are enough packets in the pipe for fast recovery. |
| 483 | * |
| 484 | * On the other hand, for extremely large MSS devices, handling |
| 485 | * smaller than MSS windows in this way does make sense. |
| 486 | */ |
| 487 | if (tp->max_window >= 512) |
| 488 | cutoff = (tp->max_window >> 1); |
| 489 | else |
| 490 | cutoff = tp->max_window; |
| 491 | |
| 492 | if (cutoff && pktsize > cutoff) |
| 493 | return max_t(int, cutoff, 68U - tp->tcp_header_len); |
Ilpo Järvinen | 0c54b85 | 2009-03-14 14:23:05 +0000 | [diff] [blame] | 494 | else |
| 495 | return pktsize; |
| 496 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 497 | |
Arnaldo Carvalho de Melo | 17b085e | 2005-08-12 12:59:17 -0300 | [diff] [blame] | 498 | /* tcp.c */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 499 | extern void tcp_get_info(struct sock *, struct tcp_info *); |
| 500 | |
| 501 | /* Read 'sendfile()'-style from a TCP socket */ |
| 502 | typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *, |
| 503 | unsigned int, size_t); |
| 504 | extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, |
| 505 | sk_read_actor_t recv_actor); |
| 506 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 507 | extern void tcp_initialize_rcv_mss(struct sock *sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | |
John Heffner | 5d424d5 | 2006-03-20 17:53:41 -0800 | [diff] [blame] | 509 | extern int tcp_mtu_to_mss(struct sock *sk, int pmtu); |
| 510 | extern int tcp_mss_to_mtu(struct sock *sk, int mss); |
| 511 | extern void tcp_mtup_init(struct sock *sk); |
| 512 | |
Damian Lukowski | f1ecd5d | 2009-08-26 00:16:31 +0000 | [diff] [blame] | 513 | static inline void tcp_bound_rto(const struct sock *sk) |
| 514 | { |
| 515 | if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX) |
| 516 | inet_csk(sk)->icsk_rto = TCP_RTO_MAX; |
| 517 | } |
| 518 | |
| 519 | static inline u32 __tcp_set_rto(const struct tcp_sock *tp) |
| 520 | { |
| 521 | return (tp->srtt >> 3) + tp->rttvar; |
| 522 | } |
| 523 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 524 | 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] | 525 | { |
| 526 | tp->pred_flags = htonl((tp->tcp_header_len << 26) | |
| 527 | ntohl(TCP_FLAG_ACK) | |
| 528 | snd_wnd); |
| 529 | } |
| 530 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 531 | static inline void tcp_fast_path_on(struct tcp_sock *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | { |
| 533 | __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale); |
| 534 | } |
| 535 | |
Ilpo Järvinen | 9e412ba | 2007-04-20 22:18:02 -0700 | [diff] [blame] | 536 | static inline void tcp_fast_path_check(struct sock *sk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 537 | { |
Ilpo Järvinen | 9e412ba | 2007-04-20 22:18:02 -0700 | [diff] [blame] | 538 | struct tcp_sock *tp = tcp_sk(sk); |
| 539 | |
David S. Miller | b03efcf | 2005-07-08 14:57:23 -0700 | [diff] [blame] | 540 | if (skb_queue_empty(&tp->out_of_order_queue) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | tp->rcv_wnd && |
| 542 | atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf && |
| 543 | !tp->urg_data) |
| 544 | tcp_fast_path_on(tp); |
| 545 | } |
| 546 | |
Satoru SATOH | 0c26689 | 2009-05-04 11:11:01 -0700 | [diff] [blame] | 547 | /* Compute the actual rto_min value */ |
| 548 | static inline u32 tcp_rto_min(struct sock *sk) |
| 549 | { |
| 550 | struct dst_entry *dst = __sk_dst_get(sk); |
| 551 | u32 rto_min = TCP_RTO_MIN; |
| 552 | |
| 553 | if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) |
| 554 | rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN); |
| 555 | return rto_min; |
| 556 | } |
| 557 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 558 | /* Compute the actual receive window we are currently advertising. |
| 559 | * Rcv_nxt can be after the window if our peer push more data |
| 560 | * than the offered window. |
| 561 | */ |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 562 | static inline u32 tcp_receive_window(const struct tcp_sock *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 563 | { |
| 564 | s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt; |
| 565 | |
| 566 | if (win < 0) |
| 567 | win = 0; |
| 568 | return (u32) win; |
| 569 | } |
| 570 | |
| 571 | /* Choose a new window, without checks for shrinking, and without |
| 572 | * scaling applied to the result. The caller does these things |
| 573 | * if necessary. This is a "raw" window selection. |
| 574 | */ |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 575 | extern u32 __tcp_select_window(struct sock *sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | |
| 577 | /* TCP timestamps are only 32-bits, this causes a slight |
| 578 | * complication on 64-bit systems since we store a snapshot |
Stephen Hemminger | 31f3426 | 2005-11-15 15:17:10 -0800 | [diff] [blame] | 579 | * of jiffies in the buffer control blocks below. We decided |
| 580 | * 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] | 581 | * casts with the following macro. |
| 582 | */ |
| 583 | #define tcp_time_stamp ((__u32)(jiffies)) |
| 584 | |
Changli Gao | a3433f3 | 2010-06-12 14:01:43 +0000 | [diff] [blame] | 585 | #define tcp_flag_byte(th) (((u_int8_t *)th)[13]) |
| 586 | |
| 587 | #define TCPHDR_FIN 0x01 |
| 588 | #define TCPHDR_SYN 0x02 |
| 589 | #define TCPHDR_RST 0x04 |
| 590 | #define TCPHDR_PSH 0x08 |
| 591 | #define TCPHDR_ACK 0x10 |
| 592 | #define TCPHDR_URG 0x20 |
| 593 | #define TCPHDR_ECE 0x40 |
| 594 | #define TCPHDR_CWR 0x80 |
| 595 | |
Stephen Hemminger | caa20d9a | 2005-11-10 17:13:47 -0800 | [diff] [blame] | 596 | /* This is what the send packet queuing engine uses to pass |
Eric Dumazet | f86586f | 2010-07-15 21:41:00 -0700 | [diff] [blame] | 597 | * TCP per-packet control information to the transmission code. |
| 598 | * We also store the host-order sequence numbers in here too. |
| 599 | * This is 44 bytes if IPV6 is enabled. |
| 600 | * If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | */ |
| 602 | struct tcp_skb_cb { |
| 603 | union { |
| 604 | struct inet_skb_parm h4; |
| 605 | #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) |
| 606 | struct inet6_skb_parm h6; |
| 607 | #endif |
| 608 | } header; /* For incoming frames */ |
| 609 | __u32 seq; /* Starting sequence number */ |
| 610 | __u32 end_seq; /* SEQ + FIN + SYN + datalen */ |
| 611 | __u32 when; /* used to compute rtt's */ |
| 612 | __u8 flags; /* TCP header flags. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | __u8 sacked; /* State flags for SACK/FACK. */ |
| 614 | #define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */ |
| 615 | #define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */ |
| 616 | #define TCPCB_LOST 0x04 /* SKB is lost */ |
| 617 | #define TCPCB_TAGBITS 0x07 /* All tag bits */ |
| 618 | |
| 619 | #define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */ |
| 620 | #define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS) |
| 621 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 622 | __u32 ack_seq; /* Sequence number ACK'd */ |
| 623 | }; |
| 624 | |
| 625 | #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) |
| 626 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 627 | /* Due to TSO, an SKB can be composed of multiple actual |
| 628 | * packets. To keep these tracked properly, we use this. |
| 629 | */ |
| 630 | static inline int tcp_skb_pcount(const struct sk_buff *skb) |
| 631 | { |
Herbert Xu | 7967168 | 2006-06-22 02:40:14 -0700 | [diff] [blame] | 632 | return skb_shinfo(skb)->gso_segs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 633 | } |
| 634 | |
| 635 | /* This is valid iff tcp_skb_pcount() > 1. */ |
| 636 | static inline int tcp_skb_mss(const struct sk_buff *skb) |
| 637 | { |
Herbert Xu | 7967168 | 2006-06-22 02:40:14 -0700 | [diff] [blame] | 638 | return skb_shinfo(skb)->gso_size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 639 | } |
| 640 | |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 641 | /* Events passed to congestion control interface */ |
| 642 | enum tcp_ca_event { |
| 643 | CA_EVENT_TX_START, /* first transmit when no packets in flight */ |
| 644 | CA_EVENT_CWND_RESTART, /* congestion window restart */ |
| 645 | CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ |
| 646 | CA_EVENT_FRTO, /* fast recovery timeout */ |
| 647 | CA_EVENT_LOSS, /* loss timeout */ |
| 648 | CA_EVENT_FAST_ACK, /* in sequence ack */ |
| 649 | CA_EVENT_SLOW_ACK, /* other ack */ |
| 650 | }; |
| 651 | |
| 652 | /* |
| 653 | * Interface for adding new TCP congestion control handlers |
| 654 | */ |
| 655 | #define TCP_CA_NAME_MAX 16 |
Stephen Hemminger | 3ff825b | 2006-11-09 16:32:06 -0800 | [diff] [blame] | 656 | #define TCP_CA_MAX 128 |
| 657 | #define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX) |
| 658 | |
Stephen Hemminger | 164891a | 2007-04-23 22:26:16 -0700 | [diff] [blame] | 659 | #define TCP_CONG_NON_RESTRICTED 0x1 |
| 660 | #define TCP_CONG_RTT_STAMP 0x2 |
| 661 | |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 662 | struct tcp_congestion_ops { |
| 663 | struct list_head list; |
Stephen Hemminger | 164891a | 2007-04-23 22:26:16 -0700 | [diff] [blame] | 664 | unsigned long flags; |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 665 | |
| 666 | /* initialize private data (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 667 | void (*init)(struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 668 | /* cleanup private data (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 669 | void (*release)(struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 670 | |
| 671 | /* return slow start threshold (required) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 672 | u32 (*ssthresh)(struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 673 | /* lower bound for congestion window (optional) */ |
Stephen Hemminger | 72dc5b9 | 2006-06-05 17:30:08 -0700 | [diff] [blame] | 674 | u32 (*min_cwnd)(const struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 675 | /* do new cwnd calculation (required) */ |
Ilpo Järvinen | c3a05c6 | 2007-12-02 00:47:59 +0200 | [diff] [blame] | 676 | void (*cong_avoid)(struct sock *sk, u32 ack, u32 in_flight); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 677 | /* call before changing ca_state (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 678 | void (*set_state)(struct sock *sk, u8 new_state); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 679 | /* call when cwnd event occurs (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 680 | void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 681 | /* new value of cwnd after loss (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 682 | u32 (*undo_cwnd)(struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 683 | /* hook for packet ack accounting (optional) */ |
Stephen Hemminger | 30cfd0b | 2007-07-25 23:49:34 -0700 | [diff] [blame] | 684 | void (*pkts_acked)(struct sock *sk, u32 num_acked, s32 rtt_us); |
Arnaldo Carvalho de Melo | 73c1f4a | 2005-08-12 12:51:49 -0300 | [diff] [blame] | 685 | /* get info for inet_diag (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 686 | void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 687 | |
| 688 | char name[TCP_CA_NAME_MAX]; |
| 689 | struct module *owner; |
| 690 | }; |
| 691 | |
| 692 | extern int tcp_register_congestion_control(struct tcp_congestion_ops *type); |
| 693 | extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); |
| 694 | |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 695 | extern void tcp_init_congestion_control(struct sock *sk); |
| 696 | extern void tcp_cleanup_congestion_control(struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 697 | extern int tcp_set_default_congestion_control(const char *name); |
| 698 | extern void tcp_get_default_congestion_control(char *name); |
Stephen Hemminger | 3ff825b | 2006-11-09 16:32:06 -0800 | [diff] [blame] | 699 | extern void tcp_get_available_congestion_control(char *buf, size_t len); |
Stephen Hemminger | ce7bc3b | 2006-11-09 16:35:15 -0800 | [diff] [blame] | 700 | extern void tcp_get_allowed_congestion_control(char *buf, size_t len); |
| 701 | extern int tcp_set_allowed_congestion_control(char *allowed); |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 702 | extern int tcp_set_congestion_control(struct sock *sk, const char *name); |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 703 | extern void tcp_slow_start(struct tcp_sock *tp); |
Ilpo Järvinen | 758ce5c | 2009-02-28 04:44:37 +0000 | [diff] [blame] | 704 | extern void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 705 | |
Stephen Hemminger | 5f8ef48 | 2005-06-23 20:37:36 -0700 | [diff] [blame] | 706 | extern struct tcp_congestion_ops tcp_init_congestion_ops; |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 707 | extern u32 tcp_reno_ssthresh(struct sock *sk); |
Ilpo Järvinen | c3a05c6 | 2007-12-02 00:47:59 +0200 | [diff] [blame] | 708 | extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight); |
Stephen Hemminger | 72dc5b9 | 2006-06-05 17:30:08 -0700 | [diff] [blame] | 709 | extern u32 tcp_reno_min_cwnd(const struct sock *sk); |
David S. Miller | a8acfba | 2005-06-23 23:45:02 -0700 | [diff] [blame] | 710 | extern struct tcp_congestion_ops tcp_reno; |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 711 | |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 712 | 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] | 713 | { |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 714 | struct inet_connection_sock *icsk = inet_csk(sk); |
| 715 | |
| 716 | if (icsk->icsk_ca_ops->set_state) |
| 717 | icsk->icsk_ca_ops->set_state(sk, ca_state); |
| 718 | icsk->icsk_ca_state = ca_state; |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 719 | } |
| 720 | |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 721 | 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] | 722 | { |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 723 | const struct inet_connection_sock *icsk = inet_csk(sk); |
| 724 | |
| 725 | if (icsk->icsk_ca_ops->cwnd_event) |
| 726 | icsk->icsk_ca_ops->cwnd_event(sk, event); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 727 | } |
| 728 | |
Ilpo Järvinen | e60402d | 2007-08-09 15:14:46 +0300 | [diff] [blame] | 729 | /* These functions determine how the current flow behaves in respect of SACK |
| 730 | * handling. SACK is negotiated with the peer, and therefore it can vary |
| 731 | * between different flows. |
| 732 | * |
| 733 | * tcp_is_sack - SACK enabled |
| 734 | * tcp_is_reno - No SACK |
| 735 | * tcp_is_fack - FACK enabled, implies SACK enabled |
| 736 | */ |
| 737 | static inline int tcp_is_sack(const struct tcp_sock *tp) |
| 738 | { |
| 739 | return tp->rx_opt.sack_ok; |
| 740 | } |
| 741 | |
| 742 | static inline int tcp_is_reno(const struct tcp_sock *tp) |
| 743 | { |
| 744 | return !tcp_is_sack(tp); |
| 745 | } |
| 746 | |
| 747 | static inline int tcp_is_fack(const struct tcp_sock *tp) |
| 748 | { |
| 749 | return tp->rx_opt.sack_ok & 2; |
| 750 | } |
| 751 | |
| 752 | static inline void tcp_enable_fack(struct tcp_sock *tp) |
| 753 | { |
| 754 | tp->rx_opt.sack_ok |= 2; |
| 755 | } |
| 756 | |
Ilpo Järvinen | 83ae408 | 2007-08-09 14:37:30 +0300 | [diff] [blame] | 757 | static inline unsigned int tcp_left_out(const struct tcp_sock *tp) |
| 758 | { |
| 759 | return tp->sacked_out + tp->lost_out; |
| 760 | } |
| 761 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 762 | /* This determines how many packets are "in the network" to the best |
| 763 | * of our knowledge. In many cases it is conservative, but where |
| 764 | * detailed information is available from the receiver (via SACK |
| 765 | * blocks etc.) we can make more aggressive calculations. |
| 766 | * |
| 767 | * Use this for decisions involving congestion control, use just |
| 768 | * tp->packets_out to determine if the send queue is empty or not. |
| 769 | * |
| 770 | * Read this equation as: |
| 771 | * |
| 772 | * "Packets sent once on transmission queue" MINUS |
| 773 | * "Packets left network, but not honestly ACKed yet" PLUS |
| 774 | * "Packets fast retransmitted" |
| 775 | */ |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 776 | 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] | 777 | { |
Ilpo Järvinen | 83ae408 | 2007-08-09 14:37:30 +0300 | [diff] [blame] | 778 | return tp->packets_out - tcp_left_out(tp) + tp->retrans_out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 779 | } |
| 780 | |
Ilpo Järvinen | 0b6a05c | 2009-09-15 01:30:10 -0700 | [diff] [blame] | 781 | #define TCP_INFINITE_SSTHRESH 0x7fffffff |
| 782 | |
| 783 | static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp) |
| 784 | { |
| 785 | return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH; |
| 786 | } |
| 787 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 788 | /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. |
| 789 | * The exception is rate halving phase, when cwnd is decreasing towards |
| 790 | * ssthresh. |
| 791 | */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 792 | static inline __u32 tcp_current_ssthresh(const struct sock *sk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 793 | { |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 794 | const struct tcp_sock *tp = tcp_sk(sk); |
| 795 | if ((1 << inet_csk(sk)->icsk_ca_state) & (TCPF_CA_CWR | TCPF_CA_Recovery)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 796 | return tp->snd_ssthresh; |
| 797 | else |
| 798 | return max(tp->snd_ssthresh, |
| 799 | ((tp->snd_cwnd >> 1) + |
| 800 | (tp->snd_cwnd >> 2))); |
| 801 | } |
| 802 | |
Ilpo Järvinen | b9c4595 | 2007-07-27 16:36:17 +0300 | [diff] [blame] | 803 | /* Use define here intentionally to get WARN_ON location shown at the caller */ |
| 804 | #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] | 805 | |
Ilpo Järvinen | 3cfe3ba | 2007-02-27 10:09:49 -0800 | [diff] [blame] | 806 | extern void tcp_enter_cwr(struct sock *sk, const int set_ssthresh); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 807 | extern __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst); |
| 808 | |
| 809 | /* Slow start with delack produces 3 packets of burst, so that |
John Heffner | dd9e0dd | 2008-04-15 15:26:39 -0700 | [diff] [blame] | 810 | * it is safe "de facto". This will be the default - same as |
| 811 | * the default reordering threshold - but if reordering increases, |
| 812 | * we must be able to allow cwnd to burst at least this much in order |
| 813 | * to not pull it back when holes are filled. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 814 | */ |
| 815 | static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp) |
| 816 | { |
John Heffner | dd9e0dd | 2008-04-15 15:26:39 -0700 | [diff] [blame] | 817 | return tp->reordering; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 818 | } |
| 819 | |
Ilpo Järvinen | 90840de | 2007-12-31 04:48:41 -0800 | [diff] [blame] | 820 | /* Returns end sequence number of the receiver's advertised window */ |
| 821 | static inline u32 tcp_wnd_end(const struct tcp_sock *tp) |
| 822 | { |
| 823 | return tp->snd_una + tp->snd_wnd; |
| 824 | } |
Ilpo Järvinen | cea14e0 | 2008-01-12 03:19:12 -0800 | [diff] [blame] | 825 | extern int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight); |
Stephen Hemminger | f4805ed | 2005-11-10 16:53:30 -0800 | [diff] [blame] | 826 | |
Chuck Lever | c1bd24b | 2007-10-23 21:08:54 -0700 | [diff] [blame] | 827 | static inline void tcp_minshall_update(struct tcp_sock *tp, unsigned int mss, |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 828 | const struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | { |
| 830 | if (skb->len < mss) |
| 831 | tp->snd_sml = TCP_SKB_CB(skb)->end_seq; |
| 832 | } |
| 833 | |
Ilpo Järvinen | 9e412ba | 2007-04-20 22:18:02 -0700 | [diff] [blame] | 834 | static inline void tcp_check_probe_timer(struct sock *sk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 835 | { |
Ilpo Järvinen | 9e412ba | 2007-04-20 22:18:02 -0700 | [diff] [blame] | 836 | struct tcp_sock *tp = tcp_sk(sk); |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 837 | const struct inet_connection_sock *icsk = inet_csk(sk); |
Ilpo Järvinen | 9e412ba | 2007-04-20 22:18:02 -0700 | [diff] [blame] | 838 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 839 | if (!tp->packets_out && !icsk->icsk_pending) |
Arnaldo Carvalho de Melo | 3f421ba | 2005-08-09 20:11:08 -0700 | [diff] [blame] | 840 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0, |
| 841 | icsk->icsk_rto, TCP_RTO_MAX); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 842 | } |
| 843 | |
Hantzis Fotis | ee7537b | 2009-03-02 22:42:02 -0800 | [diff] [blame] | 844 | static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 845 | { |
| 846 | tp->snd_wl1 = seq; |
| 847 | } |
| 848 | |
Hantzis Fotis | ee7537b | 2009-03-02 22:42:02 -0800 | [diff] [blame] | 849 | static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 850 | { |
| 851 | tp->snd_wl1 = seq; |
| 852 | } |
| 853 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 854 | /* |
| 855 | * Calculate(/check) TCP checksum |
| 856 | */ |
Frederik Deweerdt | ba7808e | 2007-02-04 20:15:27 -0800 | [diff] [blame] | 857 | static inline __sum16 tcp_v4_check(int len, __be32 saddr, |
| 858 | __be32 daddr, __wsum base) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 859 | { |
| 860 | return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base); |
| 861 | } |
| 862 | |
Al Viro | b51655b | 2006-11-14 21:40:42 -0800 | [diff] [blame] | 863 | static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 864 | { |
Herbert Xu | fb286bb | 2005-11-10 13:01:24 -0800 | [diff] [blame] | 865 | return __skb_checksum_complete(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 866 | } |
| 867 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 868 | static inline int tcp_checksum_complete(struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 869 | { |
Herbert Xu | 6047637 | 2007-04-09 11:59:39 -0700 | [diff] [blame] | 870 | return !skb_csum_unnecessary(skb) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 871 | __tcp_checksum_complete(skb); |
| 872 | } |
| 873 | |
| 874 | /* Prequeue for VJ style copy to user, combined with checksumming. */ |
| 875 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 876 | static inline void tcp_prequeue_init(struct tcp_sock *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 877 | { |
| 878 | tp->ucopy.task = NULL; |
| 879 | tp->ucopy.len = 0; |
| 880 | tp->ucopy.memory = 0; |
| 881 | skb_queue_head_init(&tp->ucopy.prequeue); |
Chris Leech | 97fc2f0 | 2006-05-23 17:55:33 -0700 | [diff] [blame] | 882 | #ifdef CONFIG_NET_DMA |
| 883 | tp->ucopy.dma_chan = NULL; |
| 884 | tp->ucopy.wakeup = 0; |
| 885 | tp->ucopy.pinned_list = NULL; |
| 886 | tp->ucopy.dma_cookie = 0; |
| 887 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 888 | } |
| 889 | |
| 890 | /* Packet is added to VJ-style prequeue for processing in process |
| 891 | * context, if a reader task is waiting. Apparently, this exciting |
| 892 | * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93) |
| 893 | * failed somewhere. Latency? Burstiness? Well, at least now we will |
| 894 | * see, why it failed. 8)8) --ANK |
| 895 | * |
| 896 | * NOTE: is this not too big to inline? |
| 897 | */ |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 898 | static inline int tcp_prequeue(struct sock *sk, struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 899 | { |
| 900 | struct tcp_sock *tp = tcp_sk(sk); |
| 901 | |
Eric Dumazet | f5f8d86 | 2009-05-07 07:08:38 +0000 | [diff] [blame] | 902 | if (sysctl_tcp_low_latency || !tp->ucopy.task) |
| 903 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 904 | |
Eric Dumazet | f5f8d86 | 2009-05-07 07:08:38 +0000 | [diff] [blame] | 905 | __skb_queue_tail(&tp->ucopy.prequeue, skb); |
| 906 | tp->ucopy.memory += skb->truesize; |
| 907 | if (tp->ucopy.memory > sk->sk_rcvbuf) { |
| 908 | struct sk_buff *skb1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 909 | |
Eric Dumazet | f5f8d86 | 2009-05-07 07:08:38 +0000 | [diff] [blame] | 910 | BUG_ON(sock_owned_by_user(sk)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 911 | |
Eric Dumazet | f5f8d86 | 2009-05-07 07:08:38 +0000 | [diff] [blame] | 912 | while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) { |
| 913 | sk_backlog_rcv(sk, skb1); |
| 914 | NET_INC_STATS_BH(sock_net(sk), |
| 915 | LINUX_MIB_TCPPREQUEUEDROPPED); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 916 | } |
Eric Dumazet | f5f8d86 | 2009-05-07 07:08:38 +0000 | [diff] [blame] | 917 | |
| 918 | tp->ucopy.memory = 0; |
| 919 | } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) { |
Eric Dumazet | aa39514 | 2010-04-20 13:03:51 +0000 | [diff] [blame] | 920 | wake_up_interruptible_sync_poll(sk_sleep(sk), |
Eric Dumazet | 7aedec2 | 2009-05-07 07:20:39 +0000 | [diff] [blame] | 921 | POLLIN | POLLRDNORM | POLLRDBAND); |
Eric Dumazet | f5f8d86 | 2009-05-07 07:08:38 +0000 | [diff] [blame] | 922 | if (!inet_csk_ack_scheduled(sk)) |
| 923 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
David S. Miller | 22f6dac | 2009-05-08 02:48:30 -0700 | [diff] [blame] | 924 | (3 * tcp_rto_min(sk)) / 4, |
Eric Dumazet | f5f8d86 | 2009-05-07 07:08:38 +0000 | [diff] [blame] | 925 | TCP_RTO_MAX); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 926 | } |
Eric Dumazet | f5f8d86 | 2009-05-07 07:08:38 +0000 | [diff] [blame] | 927 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 928 | } |
| 929 | |
| 930 | |
| 931 | #undef STATE_TRACE |
| 932 | |
| 933 | #ifdef STATE_TRACE |
| 934 | static const char *statename[]={ |
| 935 | "Unused","Established","Syn Sent","Syn Recv", |
| 936 | "Fin Wait 1","Fin Wait 2","Time Wait", "Close", |
| 937 | "Close Wait","Last ACK","Listen","Closing" |
| 938 | }; |
| 939 | #endif |
Ilpo Järvinen | 490d504 | 2008-01-12 03:17:20 -0800 | [diff] [blame] | 940 | extern void tcp_set_state(struct sock *sk, int state); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 941 | |
Andi Kleen | 4ac02ba | 2007-04-20 17:11:46 -0700 | [diff] [blame] | 942 | extern void tcp_done(struct sock *sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 943 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 944 | static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 945 | { |
| 946 | rx_opt->dsack = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 947 | rx_opt->num_sacks = 0; |
| 948 | } |
| 949 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 950 | /* Determine a window scaling and initial window to offer. */ |
| 951 | extern void tcp_select_initial_window(int __space, __u32 mss, |
| 952 | __u32 *rcv_wnd, __u32 *window_clamp, |
laurent chavey | 31d1292 | 2009-12-15 11:15:28 +0000 | [diff] [blame] | 953 | int wscale_ok, __u8 *rcv_wscale, |
| 954 | __u32 init_rcv_wnd); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 955 | |
| 956 | static inline int tcp_win_from_space(int space) |
| 957 | { |
| 958 | return sysctl_tcp_adv_win_scale<=0 ? |
| 959 | (space>>(-sysctl_tcp_adv_win_scale)) : |
| 960 | space - (space>>sysctl_tcp_adv_win_scale); |
| 961 | } |
| 962 | |
| 963 | /* Note: caller must be prepared to deal with negative returns */ |
| 964 | static inline int tcp_space(const struct sock *sk) |
| 965 | { |
| 966 | return tcp_win_from_space(sk->sk_rcvbuf - |
| 967 | atomic_read(&sk->sk_rmem_alloc)); |
| 968 | } |
| 969 | |
| 970 | static inline int tcp_full_space(const struct sock *sk) |
| 971 | { |
| 972 | return tcp_win_from_space(sk->sk_rcvbuf); |
| 973 | } |
| 974 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 975 | static inline void tcp_openreq_init(struct request_sock *req, |
| 976 | struct tcp_options_received *rx_opt, |
| 977 | struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 978 | { |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 979 | struct inet_request_sock *ireq = inet_rsk(req); |
| 980 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 981 | req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */ |
Florian Westphal | 4dfc281 | 2008-04-10 03:12:40 -0700 | [diff] [blame] | 982 | req->cookie_ts = 0; |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 983 | tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 984 | req->mss = rx_opt->mss_clamp; |
| 985 | req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0; |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 986 | ireq->tstamp_ok = rx_opt->tstamp_ok; |
| 987 | ireq->sack_ok = rx_opt->sack_ok; |
| 988 | ireq->snd_wscale = rx_opt->snd_wscale; |
| 989 | ireq->wscale_ok = rx_opt->wscale_ok; |
| 990 | ireq->acked = 0; |
| 991 | ireq->ecn_ok = 0; |
Arnaldo Carvalho de Melo | aa8223c | 2007-04-10 21:04:22 -0700 | [diff] [blame] | 992 | ireq->rmt_port = tcp_hdr(skb)->source; |
KOVACS Krisztian | a3116ac5 | 2008-10-01 07:46:49 -0700 | [diff] [blame] | 993 | ireq->loc_port = tcp_hdr(skb)->dest; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 994 | } |
| 995 | |
Pavel Emelyanov | 5c52ba1 | 2008-07-16 20:28:10 -0700 | [diff] [blame] | 996 | extern void tcp_enter_memory_pressure(struct sock *sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 997 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 998 | static inline int keepalive_intvl_when(const struct tcp_sock *tp) |
| 999 | { |
| 1000 | return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl; |
| 1001 | } |
| 1002 | |
| 1003 | static inline int keepalive_time_when(const struct tcp_sock *tp) |
| 1004 | { |
| 1005 | return tp->keepalive_time ? : sysctl_tcp_keepalive_time; |
| 1006 | } |
| 1007 | |
Eric Dumazet | df19a62 | 2009-08-28 23:48:54 -0700 | [diff] [blame] | 1008 | static inline int keepalive_probes(const struct tcp_sock *tp) |
| 1009 | { |
| 1010 | return tp->keepalive_probes ? : sysctl_tcp_keepalive_probes; |
| 1011 | } |
| 1012 | |
Flavio Leitner | 6c37e5d | 2010-04-26 18:33:27 +0000 | [diff] [blame] | 1013 | static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp) |
| 1014 | { |
| 1015 | const struct inet_connection_sock *icsk = &tp->inet_conn; |
| 1016 | |
| 1017 | return min_t(u32, tcp_time_stamp - icsk->icsk_ack.lrcvtime, |
| 1018 | tcp_time_stamp - tp->rcv_tstamp); |
| 1019 | } |
| 1020 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 1021 | static inline int tcp_fin_time(const struct sock *sk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1022 | { |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 1023 | int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout; |
| 1024 | const int rto = inet_csk(sk)->icsk_rto; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1025 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 1026 | if (fin_timeout < (rto << 2) - (rto >> 1)) |
| 1027 | fin_timeout = (rto << 2) - (rto >> 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1028 | |
| 1029 | return fin_timeout; |
| 1030 | } |
| 1031 | |
Ilpo Järvinen | c887e6d | 2009-03-14 14:23:03 +0000 | [diff] [blame] | 1032 | static inline int tcp_paws_check(const struct tcp_options_received *rx_opt, |
| 1033 | int paws_win) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1034 | { |
Ilpo Järvinen | c887e6d | 2009-03-14 14:23:03 +0000 | [diff] [blame] | 1035 | if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win) |
| 1036 | return 1; |
| 1037 | if (unlikely(get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS)) |
| 1038 | return 1; |
| 1039 | |
| 1040 | return 0; |
| 1041 | } |
| 1042 | |
| 1043 | static inline int tcp_paws_reject(const struct tcp_options_received *rx_opt, |
| 1044 | int rst) |
| 1045 | { |
| 1046 | if (tcp_paws_check(rx_opt, 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1047 | return 0; |
| 1048 | |
| 1049 | /* RST segments are not recommended to carry timestamp, |
| 1050 | and, if they do, it is recommended to ignore PAWS because |
| 1051 | "their cleanup function should take precedence over timestamps." |
| 1052 | Certainly, it is mistake. It is necessary to understand the reasons |
| 1053 | of this constraint to relax it: if peer reboots, clock may go |
| 1054 | out-of-sync and half-open connections will not be reset. |
| 1055 | Actually, the problem would be not existing if all |
| 1056 | the implementations followed draft about maintaining clock |
| 1057 | via reboots. Linux-2.2 DOES NOT! |
| 1058 | |
| 1059 | However, we can relax time bounds for RST segments to MSL. |
| 1060 | */ |
James Morris | 9d729f7 | 2007-03-04 16:12:44 -0800 | [diff] [blame] | 1061 | if (rst && get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1062 | return 0; |
| 1063 | return 1; |
| 1064 | } |
| 1065 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1066 | #define TCP_CHECK_TIMER(sk) do { } while (0) |
| 1067 | |
Pavel Emelyanov | a9c19329 | 2008-07-16 20:21:42 -0700 | [diff] [blame] | 1068 | static inline void tcp_mib_init(struct net *net) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1069 | { |
| 1070 | /* See RFC 2012 */ |
Pavel Emelyanov | cf1100a | 2008-07-16 20:27:38 -0700 | [diff] [blame] | 1071 | TCP_ADD_STATS_USER(net, TCP_MIB_RTOALGORITHM, 1); |
| 1072 | TCP_ADD_STATS_USER(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); |
| 1073 | TCP_ADD_STATS_USER(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); |
| 1074 | TCP_ADD_STATS_USER(net, TCP_MIB_MAXCONN, -1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1075 | } |
| 1076 | |
Ilpo Järvinen | 5af4ec2 | 2007-09-20 11:30:48 -0700 | [diff] [blame] | 1077 | /* from STCP */ |
Ilpo Järvinen | ef9da47 | 2008-09-20 21:25:15 -0700 | [diff] [blame] | 1078 | 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] | 1079 | { |
Stephen Hemminger | 6a438bb | 2005-11-10 17:14:59 -0800 | [diff] [blame] | 1080 | tp->lost_skb_hint = NULL; |
| 1081 | tp->scoreboard_skb_hint = NULL; |
Ilpo Järvinen | ef9da47 | 2008-09-20 21:25:15 -0700 | [diff] [blame] | 1082 | } |
| 1083 | |
| 1084 | static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp) |
| 1085 | { |
| 1086 | tcp_clear_retrans_hints_partial(tp); |
Stephen Hemminger | 6a438bb | 2005-11-10 17:14:59 -0800 | [diff] [blame] | 1087 | tp->retransmit_skb_hint = NULL; |
Ilpo Järvinen | b768920 | 2007-09-20 11:37:19 -0700 | [diff] [blame] | 1088 | } |
| 1089 | |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1090 | /* MD5 Signature */ |
| 1091 | struct crypto_hash; |
| 1092 | |
| 1093 | /* - key database */ |
| 1094 | struct tcp_md5sig_key { |
| 1095 | u8 *key; |
| 1096 | u8 keylen; |
| 1097 | }; |
| 1098 | |
| 1099 | struct tcp4_md5sig_key { |
David S. Miller | f8ab18d | 2007-09-28 15:18:35 -0700 | [diff] [blame] | 1100 | struct tcp_md5sig_key base; |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1101 | __be32 addr; |
| 1102 | }; |
| 1103 | |
| 1104 | struct tcp6_md5sig_key { |
David S. Miller | f8ab18d | 2007-09-28 15:18:35 -0700 | [diff] [blame] | 1105 | struct tcp_md5sig_key base; |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1106 | #if 0 |
| 1107 | u32 scope_id; /* XXX */ |
| 1108 | #endif |
| 1109 | struct in6_addr addr; |
| 1110 | }; |
| 1111 | |
| 1112 | /* - sock block */ |
| 1113 | struct tcp_md5sig_info { |
| 1114 | struct tcp4_md5sig_key *keys4; |
| 1115 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) |
| 1116 | struct tcp6_md5sig_key *keys6; |
| 1117 | u32 entries6; |
| 1118 | u32 alloced6; |
| 1119 | #endif |
| 1120 | u32 entries4; |
| 1121 | u32 alloced4; |
| 1122 | }; |
| 1123 | |
| 1124 | /* - pseudo header */ |
| 1125 | struct tcp4_pseudohdr { |
| 1126 | __be32 saddr; |
| 1127 | __be32 daddr; |
| 1128 | __u8 pad; |
| 1129 | __u8 protocol; |
| 1130 | __be16 len; |
| 1131 | }; |
| 1132 | |
| 1133 | struct tcp6_pseudohdr { |
| 1134 | struct in6_addr saddr; |
| 1135 | struct in6_addr daddr; |
| 1136 | __be32 len; |
| 1137 | __be32 protocol; /* including padding */ |
| 1138 | }; |
| 1139 | |
| 1140 | union tcp_md5sum_block { |
| 1141 | struct tcp4_pseudohdr ip4; |
| 1142 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) |
| 1143 | struct tcp6_pseudohdr ip6; |
| 1144 | #endif |
| 1145 | }; |
| 1146 | |
| 1147 | /* - pool: digest algorithm, hash description and scratch buffer */ |
| 1148 | struct tcp_md5sig_pool { |
| 1149 | struct hash_desc md5_desc; |
| 1150 | union tcp_md5sum_block md5_blk; |
| 1151 | }; |
| 1152 | |
| 1153 | #define TCP_MD5SIG_MAXKEYS (~(u32)0) /* really?! */ |
| 1154 | |
| 1155 | /* - functions */ |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 1156 | extern int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key, |
| 1157 | struct sock *sk, struct request_sock *req, |
| 1158 | struct sk_buff *skb); |
| 1159 | extern struct tcp_md5sig_key * tcp_v4_md5_lookup(struct sock *sk, |
| 1160 | struct sock *addr_sk); |
| 1161 | extern int tcp_v4_md5_do_add(struct sock *sk, __be32 addr, u8 *newkey, |
| 1162 | u8 newkeylen); |
| 1163 | extern int tcp_v4_md5_do_del(struct sock *sk, __be32 addr); |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1164 | |
YOSHIFUJI Hideaki | 9501f97 | 2008-04-18 12:45:16 +0900 | [diff] [blame] | 1165 | #ifdef CONFIG_TCP_MD5SIG |
| 1166 | #define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_keylen ? \ |
| 1167 | &(struct tcp_md5sig_key) { \ |
| 1168 | .key = (twsk)->tw_md5_key, \ |
| 1169 | .keylen = (twsk)->tw_md5_keylen, \ |
| 1170 | } : NULL) |
| 1171 | #else |
| 1172 | #define tcp_twsk_md5_key(twsk) NULL |
| 1173 | #endif |
| 1174 | |
Tejun Heo | 7d720c3 | 2010-02-16 15:20:26 +0000 | [diff] [blame] | 1175 | extern struct tcp_md5sig_pool * __percpu *tcp_alloc_md5sig_pool(struct sock *); |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 1176 | extern void tcp_free_md5sig_pool(void); |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1177 | |
Eric Dumazet | 35790c0 | 2010-05-16 00:34:04 -0700 | [diff] [blame] | 1178 | extern struct tcp_md5sig_pool *tcp_get_md5sig_pool(void); |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 1179 | extern void tcp_put_md5sig_pool(void); |
Eric Dumazet | 35790c0 | 2010-05-16 00:34:04 -0700 | [diff] [blame] | 1180 | |
Adam Langley | 49a72df | 2008-07-19 00:01:42 -0700 | [diff] [blame] | 1181 | extern int tcp_md5_hash_header(struct tcp_md5sig_pool *, struct tcphdr *); |
| 1182 | extern int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, struct sk_buff *, |
| 1183 | unsigned header_len); |
| 1184 | extern int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, |
| 1185 | struct tcp_md5sig_key *key); |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1186 | |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1187 | /* write queue abstraction */ |
| 1188 | static inline void tcp_write_queue_purge(struct sock *sk) |
| 1189 | { |
| 1190 | struct sk_buff *skb; |
| 1191 | |
| 1192 | while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) |
Hideo Aoki | 3ab224b | 2007-12-31 00:11:19 -0800 | [diff] [blame] | 1193 | sk_wmem_free_skb(sk, skb); |
| 1194 | sk_mem_reclaim(sk); |
Ilpo Järvinen | 8818a9d | 2009-12-02 22:24:02 -0800 | [diff] [blame] | 1195 | tcp_clear_all_retrans_hints(tcp_sk(sk)); |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1196 | } |
| 1197 | |
| 1198 | static inline struct sk_buff *tcp_write_queue_head(struct sock *sk) |
| 1199 | { |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1200 | return skb_peek(&sk->sk_write_queue); |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1201 | } |
| 1202 | |
| 1203 | static inline struct sk_buff *tcp_write_queue_tail(struct sock *sk) |
| 1204 | { |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1205 | return skb_peek_tail(&sk->sk_write_queue); |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1206 | } |
| 1207 | |
| 1208 | static inline struct sk_buff *tcp_write_queue_next(struct sock *sk, struct sk_buff *skb) |
| 1209 | { |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1210 | return skb_queue_next(&sk->sk_write_queue, skb); |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1211 | } |
| 1212 | |
Ilpo Järvinen | 832d11c | 2008-11-24 21:20:15 -0800 | [diff] [blame] | 1213 | static inline struct sk_buff *tcp_write_queue_prev(struct sock *sk, struct sk_buff *skb) |
| 1214 | { |
| 1215 | return skb_queue_prev(&sk->sk_write_queue, skb); |
| 1216 | } |
| 1217 | |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1218 | #define tcp_for_write_queue(skb, sk) \ |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1219 | skb_queue_walk(&(sk)->sk_write_queue, skb) |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1220 | |
| 1221 | #define tcp_for_write_queue_from(skb, sk) \ |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1222 | skb_queue_walk_from(&(sk)->sk_write_queue, skb) |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1223 | |
Ilpo Järvinen | 234b686 | 2007-12-02 00:48:02 +0200 | [diff] [blame] | 1224 | #define tcp_for_write_queue_from_safe(skb, tmp, sk) \ |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1225 | skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp) |
Ilpo Järvinen | 234b686 | 2007-12-02 00:48:02 +0200 | [diff] [blame] | 1226 | |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1227 | static inline struct sk_buff *tcp_send_head(struct sock *sk) |
| 1228 | { |
| 1229 | return sk->sk_send_head; |
| 1230 | } |
| 1231 | |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1232 | static inline bool tcp_skb_is_last(const struct sock *sk, |
| 1233 | const struct sk_buff *skb) |
| 1234 | { |
| 1235 | return skb_queue_is_last(&sk->sk_write_queue, skb); |
| 1236 | } |
| 1237 | |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1238 | static inline void tcp_advance_send_head(struct sock *sk, struct sk_buff *skb) |
| 1239 | { |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1240 | if (tcp_skb_is_last(sk, skb)) |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1241 | sk->sk_send_head = NULL; |
David S. Miller | cd07a8e | 2008-09-23 00:50:13 -0700 | [diff] [blame] | 1242 | else |
| 1243 | sk->sk_send_head = tcp_write_queue_next(sk, skb); |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1244 | } |
| 1245 | |
| 1246 | static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked) |
| 1247 | { |
| 1248 | if (sk->sk_send_head == skb_unlinked) |
| 1249 | sk->sk_send_head = NULL; |
| 1250 | } |
| 1251 | |
| 1252 | static inline void tcp_init_send_head(struct sock *sk) |
| 1253 | { |
| 1254 | sk->sk_send_head = NULL; |
| 1255 | } |
| 1256 | |
| 1257 | static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) |
| 1258 | { |
| 1259 | __skb_queue_tail(&sk->sk_write_queue, skb); |
| 1260 | } |
| 1261 | |
| 1262 | static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb) |
| 1263 | { |
| 1264 | __tcp_add_write_queue_tail(sk, skb); |
| 1265 | |
| 1266 | /* Queue it, remembering where we must start sending. */ |
Ilpo Järvinen | 6859d49 | 2007-12-02 00:48:06 +0200 | [diff] [blame] | 1267 | if (sk->sk_send_head == NULL) { |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1268 | sk->sk_send_head = skb; |
Ilpo Järvinen | 6859d49 | 2007-12-02 00:48:06 +0200 | [diff] [blame] | 1269 | |
| 1270 | if (tcp_sk(sk)->highest_sack == NULL) |
| 1271 | tcp_sk(sk)->highest_sack = skb; |
| 1272 | } |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1273 | } |
| 1274 | |
| 1275 | static inline void __tcp_add_write_queue_head(struct sock *sk, struct sk_buff *skb) |
| 1276 | { |
| 1277 | __skb_queue_head(&sk->sk_write_queue, skb); |
| 1278 | } |
| 1279 | |
| 1280 | /* Insert buff after skb on the write queue of sk. */ |
| 1281 | static inline void tcp_insert_write_queue_after(struct sk_buff *skb, |
| 1282 | struct sk_buff *buff, |
| 1283 | struct sock *sk) |
| 1284 | { |
Gerrit Renker | 7de6c03 | 2008-04-14 00:05:09 -0700 | [diff] [blame] | 1285 | __skb_queue_after(&sk->sk_write_queue, skb, buff); |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1286 | } |
| 1287 | |
David S. Miller | 43f59c8 | 2008-09-21 21:28:51 -0700 | [diff] [blame] | 1288 | /* Insert new before skb on the write queue of sk. */ |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1289 | static inline void tcp_insert_write_queue_before(struct sk_buff *new, |
| 1290 | struct sk_buff *skb, |
| 1291 | struct sock *sk) |
| 1292 | { |
David S. Miller | 43f59c8 | 2008-09-21 21:28:51 -0700 | [diff] [blame] | 1293 | __skb_queue_before(&sk->sk_write_queue, skb, new); |
Ilpo Järvinen | 6e42141 | 2007-11-19 23:24:09 -0800 | [diff] [blame] | 1294 | |
| 1295 | if (sk->sk_send_head == skb) |
| 1296 | sk->sk_send_head = new; |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1297 | } |
| 1298 | |
| 1299 | static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk) |
| 1300 | { |
| 1301 | __skb_unlink(skb, &sk->sk_write_queue); |
| 1302 | } |
| 1303 | |
David S. Miller | fe067e8 | 2007-03-07 12:12:44 -0800 | [diff] [blame] | 1304 | static inline int tcp_write_queue_empty(struct sock *sk) |
| 1305 | { |
| 1306 | return skb_queue_empty(&sk->sk_write_queue); |
| 1307 | } |
| 1308 | |
Krishna Kumar | 12d50c4 | 2009-12-08 22:26:13 +0000 | [diff] [blame] | 1309 | static inline void tcp_push_pending_frames(struct sock *sk) |
| 1310 | { |
| 1311 | if (tcp_send_head(sk)) { |
| 1312 | struct tcp_sock *tp = tcp_sk(sk); |
| 1313 | |
| 1314 | __tcp_push_pending_frames(sk, tcp_current_mss(sk), tp->nonagle); |
| 1315 | } |
| 1316 | } |
| 1317 | |
Ilpo Järvinen | a47e5a9 | 2007-11-15 19:41:46 -0800 | [diff] [blame] | 1318 | /* Start sequence of the highest skb with SACKed bit, valid only if |
| 1319 | * sacked > 0 or when the caller has ensured validity by itself. |
| 1320 | */ |
| 1321 | static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp) |
| 1322 | { |
| 1323 | if (!tp->sacked_out) |
| 1324 | return tp->snd_una; |
Ilpo Järvinen | 6859d49 | 2007-12-02 00:48:06 +0200 | [diff] [blame] | 1325 | |
| 1326 | if (tp->highest_sack == NULL) |
| 1327 | return tp->snd_nxt; |
| 1328 | |
Ilpo Järvinen | a47e5a9 | 2007-11-15 19:41:46 -0800 | [diff] [blame] | 1329 | return TCP_SKB_CB(tp->highest_sack)->seq; |
| 1330 | } |
| 1331 | |
Ilpo Järvinen | 6859d49 | 2007-12-02 00:48:06 +0200 | [diff] [blame] | 1332 | static inline void tcp_advance_highest_sack(struct sock *sk, struct sk_buff *skb) |
| 1333 | { |
| 1334 | tcp_sk(sk)->highest_sack = tcp_skb_is_last(sk, skb) ? NULL : |
| 1335 | tcp_write_queue_next(sk, skb); |
| 1336 | } |
| 1337 | |
| 1338 | static inline struct sk_buff *tcp_highest_sack(struct sock *sk) |
| 1339 | { |
| 1340 | return tcp_sk(sk)->highest_sack; |
| 1341 | } |
| 1342 | |
| 1343 | static inline void tcp_highest_sack_reset(struct sock *sk) |
| 1344 | { |
| 1345 | tcp_sk(sk)->highest_sack = tcp_write_queue_head(sk); |
| 1346 | } |
| 1347 | |
| 1348 | /* Called when old skb is about to be deleted (to be combined with new skb) */ |
| 1349 | static inline void tcp_highest_sack_combine(struct sock *sk, |
| 1350 | struct sk_buff *old, |
| 1351 | struct sk_buff *new) |
| 1352 | { |
| 1353 | if (tcp_sk(sk)->sacked_out && (old == tcp_sk(sk)->highest_sack)) |
| 1354 | tcp_sk(sk)->highest_sack = new; |
| 1355 | } |
| 1356 | |
Andreas Petlund | 5aa4b32 | 2010-02-18 02:45:45 +0000 | [diff] [blame] | 1357 | /* Determines whether this is a thin stream (which may suffer from |
| 1358 | * increased latency). Used to trigger latency-reducing mechanisms. |
| 1359 | */ |
| 1360 | static inline unsigned int tcp_stream_is_thin(struct tcp_sock *tp) |
| 1361 | { |
| 1362 | return tp->packets_out < 4 && !tcp_in_initial_slowstart(tp); |
| 1363 | } |
| 1364 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1365 | /* /proc */ |
| 1366 | enum tcp_seq_states { |
| 1367 | TCP_SEQ_STATE_LISTENING, |
| 1368 | TCP_SEQ_STATE_OPENREQ, |
| 1369 | TCP_SEQ_STATE_ESTABLISHED, |
| 1370 | TCP_SEQ_STATE_TIME_WAIT, |
| 1371 | }; |
| 1372 | |
| 1373 | struct tcp_seq_afinfo { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1374 | char *name; |
| 1375 | sa_family_t family; |
Denis V. Lunev | 68fcadd | 2008-04-13 22:13:30 -0700 | [diff] [blame] | 1376 | struct file_operations seq_fops; |
Denis V. Lunev | 9427c4b | 2008-04-13 22:12:13 -0700 | [diff] [blame] | 1377 | struct seq_operations seq_ops; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1378 | }; |
| 1379 | |
| 1380 | struct tcp_iter_state { |
Denis V. Lunev | a4146b1 | 2008-04-13 22:11:14 -0700 | [diff] [blame] | 1381 | struct seq_net_private p; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1382 | sa_family_t family; |
| 1383 | enum tcp_seq_states state; |
| 1384 | struct sock *syn_wait_sk; |
Tom Herbert | a8b690f | 2010-06-07 00:43:42 -0700 | [diff] [blame] | 1385 | int bucket, offset, sbucket, num, uid; |
| 1386 | loff_t last_pos; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1387 | }; |
| 1388 | |
Daniel Lezcano | 6f8b13b | 2008-03-21 04:14:45 -0700 | [diff] [blame] | 1389 | extern int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo); |
| 1390 | extern void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1391 | |
Arnaldo Carvalho de Melo | 2038073 | 2005-08-16 02:18:02 -0300 | [diff] [blame] | 1392 | extern struct request_sock_ops tcp_request_sock_ops; |
Glenn Griffin | c6aefaf | 2008-02-07 21:49:26 -0800 | [diff] [blame] | 1393 | extern struct request_sock_ops tcp6_request_sock_ops; |
Arnaldo Carvalho de Melo | 2038073 | 2005-08-16 02:18:02 -0300 | [diff] [blame] | 1394 | |
Brian Haley | 7d06b2e | 2008-06-14 17:04:49 -0700 | [diff] [blame] | 1395 | extern void tcp_v4_destroy_sock(struct sock *sk); |
Arnaldo Carvalho de Melo | 2038073 | 2005-08-16 02:18:02 -0300 | [diff] [blame] | 1396 | |
Herbert Xu | a430a43 | 2006-07-08 13:34:56 -0700 | [diff] [blame] | 1397 | extern int tcp_v4_gso_send_check(struct sk_buff *skb); |
Herbert Xu | 576a30e | 2006-06-27 13:22:38 -0700 | [diff] [blame] | 1398 | extern struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features); |
Herbert Xu | bf296b1 | 2008-12-15 23:43:36 -0800 | [diff] [blame] | 1399 | extern struct sk_buff **tcp_gro_receive(struct sk_buff **head, |
| 1400 | struct sk_buff *skb); |
| 1401 | extern struct sk_buff **tcp4_gro_receive(struct sk_buff **head, |
| 1402 | struct sk_buff *skb); |
| 1403 | extern int tcp_gro_complete(struct sk_buff *skb); |
| 1404 | extern int tcp4_gro_complete(struct sk_buff *skb); |
Herbert Xu | f4c50d9 | 2006-06-22 03:02:40 -0700 | [diff] [blame] | 1405 | |
Arnaldo Carvalho de Melo | 2038073 | 2005-08-16 02:18:02 -0300 | [diff] [blame] | 1406 | #ifdef CONFIG_PROC_FS |
Changli Gao | 53d3176 | 2010-07-10 20:41:06 +0000 | [diff] [blame] | 1407 | extern int tcp4_proc_init(void); |
Arnaldo Carvalho de Melo | 2038073 | 2005-08-16 02:18:02 -0300 | [diff] [blame] | 1408 | extern void tcp4_proc_exit(void); |
| 1409 | #endif |
| 1410 | |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1411 | /* TCP af-specific functions */ |
| 1412 | struct tcp_sock_af_ops { |
| 1413 | #ifdef CONFIG_TCP_MD5SIG |
| 1414 | struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk, |
| 1415 | struct sock *addr_sk); |
| 1416 | int (*calc_md5_hash) (char *location, |
| 1417 | struct tcp_md5sig_key *md5, |
| 1418 | struct sock *sk, |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1419 | struct request_sock *req, |
Adam Langley | 49a72df | 2008-07-19 00:01:42 -0700 | [diff] [blame] | 1420 | struct sk_buff *skb); |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1421 | int (*md5_add) (struct sock *sk, |
| 1422 | struct sock *addr_sk, |
| 1423 | u8 *newkey, |
| 1424 | u8 len); |
| 1425 | int (*md5_parse) (struct sock *sk, |
| 1426 | char __user *optval, |
| 1427 | int optlen); |
| 1428 | #endif |
| 1429 | }; |
| 1430 | |
| 1431 | struct tcp_request_sock_ops { |
| 1432 | #ifdef CONFIG_TCP_MD5SIG |
| 1433 | struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk, |
| 1434 | struct request_sock *req); |
John Dykstra | e3afe7b | 2009-07-16 05:04:51 +0000 | [diff] [blame] | 1435 | int (*calc_md5_hash) (char *location, |
| 1436 | struct tcp_md5sig_key *md5, |
| 1437 | struct sock *sk, |
| 1438 | struct request_sock *req, |
| 1439 | struct sk_buff *skb); |
YOSHIFUJI Hideaki | cfb6eeb | 2006-11-14 19:07:45 -0800 | [diff] [blame] | 1440 | #endif |
| 1441 | }; |
| 1442 | |
William Allen Simpson | da5c78c | 2009-12-02 18:12:09 +0000 | [diff] [blame] | 1443 | /* Using SHA1 for now, define some constants. |
| 1444 | */ |
| 1445 | #define COOKIE_DIGEST_WORDS (SHA_DIGEST_WORDS) |
| 1446 | #define COOKIE_MESSAGE_WORDS (SHA_MESSAGE_BYTES / 4) |
| 1447 | #define COOKIE_WORKSPACE_WORDS (COOKIE_DIGEST_WORDS + COOKIE_MESSAGE_WORDS) |
| 1448 | |
| 1449 | extern int tcp_cookie_generator(u32 *bakery); |
| 1450 | |
William Allen Simpson | 435cf55 | 2009-12-02 18:17:05 +0000 | [diff] [blame] | 1451 | /** |
| 1452 | * struct tcp_cookie_values - each socket needs extra space for the |
| 1453 | * cookies, together with (optional) space for any SYN data. |
| 1454 | * |
| 1455 | * A tcp_sock contains a pointer to the current value, and this is |
| 1456 | * cloned to the tcp_timewait_sock. |
| 1457 | * |
| 1458 | * @cookie_pair: variable data from the option exchange. |
| 1459 | * |
| 1460 | * @cookie_desired: user specified tcpct_cookie_desired. Zero |
| 1461 | * indicates default (sysctl_tcp_cookie_size). |
| 1462 | * After cookie sent, remembers size of cookie. |
| 1463 | * Range 0, TCP_COOKIE_MIN to TCP_COOKIE_MAX. |
| 1464 | * |
| 1465 | * @s_data_desired: user specified tcpct_s_data_desired. When the |
| 1466 | * constant payload is specified (@s_data_constant), |
| 1467 | * holds its length instead. |
| 1468 | * Range 0 to TCP_MSS_DESIRED. |
| 1469 | * |
| 1470 | * @s_data_payload: constant data that is to be included in the |
| 1471 | * payload of SYN or SYNACK segments when the |
| 1472 | * cookie option is present. |
| 1473 | */ |
| 1474 | struct tcp_cookie_values { |
| 1475 | struct kref kref; |
| 1476 | u8 cookie_pair[TCP_COOKIE_PAIR_SIZE]; |
| 1477 | u8 cookie_pair_size; |
| 1478 | u8 cookie_desired; |
| 1479 | u16 s_data_desired:11, |
| 1480 | s_data_constant:1, |
| 1481 | s_data_in:1, |
| 1482 | s_data_out:1, |
| 1483 | s_data_unused:2; |
| 1484 | u8 s_data_payload[0]; |
| 1485 | }; |
| 1486 | |
| 1487 | static inline void tcp_cookie_values_release(struct kref *kref) |
| 1488 | { |
| 1489 | kfree(container_of(kref, struct tcp_cookie_values, kref)); |
| 1490 | } |
| 1491 | |
| 1492 | /* The length of constant payload data. Note that s_data_desired is |
| 1493 | * overloaded, depending on s_data_constant: either the length of constant |
| 1494 | * data (returned here) or the limit on variable data. |
| 1495 | */ |
| 1496 | static inline int tcp_s_data_size(const struct tcp_sock *tp) |
| 1497 | { |
| 1498 | return (tp->cookie_values != NULL && tp->cookie_values->s_data_constant) |
| 1499 | ? tp->cookie_values->s_data_desired |
| 1500 | : 0; |
| 1501 | } |
| 1502 | |
| 1503 | /** |
| 1504 | * struct tcp_extend_values - tcp_ipv?.c to tcp_output.c workspace. |
| 1505 | * |
| 1506 | * As tcp_request_sock has already been extended in other places, the |
| 1507 | * only remaining method is to pass stack values along as function |
| 1508 | * parameters. These parameters are not needed after sending SYNACK. |
| 1509 | * |
| 1510 | * @cookie_bakery: cryptographic secret and message workspace. |
| 1511 | * |
| 1512 | * @cookie_plus: bytes in authenticator/cookie option, copied from |
| 1513 | * struct tcp_options_received (above). |
| 1514 | */ |
| 1515 | struct tcp_extend_values { |
| 1516 | struct request_values rv; |
| 1517 | u32 cookie_bakery[COOKIE_WORKSPACE_WORDS]; |
| 1518 | u8 cookie_plus:6, |
| 1519 | cookie_out_never:1, |
| 1520 | cookie_in_always:1; |
| 1521 | }; |
| 1522 | |
| 1523 | static inline struct tcp_extend_values *tcp_xv(struct request_values *rvp) |
| 1524 | { |
| 1525 | return (struct tcp_extend_values *)rvp; |
| 1526 | } |
| 1527 | |
Denis V. Lunev | 9b0f976 | 2008-02-29 11:13:15 -0800 | [diff] [blame] | 1528 | extern void tcp_v4_init(void); |
Arnaldo Carvalho de Melo | 2038073 | 2005-08-16 02:18:02 -0300 | [diff] [blame] | 1529 | extern void tcp_init(void); |
| 1530 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1531 | #endif /* _TCP_H */ |