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> |
Arnaldo Carvalho de Melo | 3f421ba | 2005-08-09 20:11:08 -0700 | [diff] [blame] | 31 | |
| 32 | #include <net/inet_connection_sock.h> |
Arnaldo Carvalho de Melo | 295ff7e | 2005-08-09 20:44:40 -0700 | [diff] [blame] | 33 | #include <net/inet_timewait_sock.h> |
Arnaldo Carvalho de Melo | 77d8bf9 | 2005-08-09 20:00:51 -0700 | [diff] [blame] | 34 | #include <net/inet_hashtables.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | #include <net/checksum.h> |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 36 | #include <net/request_sock.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | #include <net/sock.h> |
| 38 | #include <net/snmp.h> |
| 39 | #include <net/ip.h> |
Arnaldo Carvalho de Melo | c752f07 | 2005-08-09 20:08:28 -0700 | [diff] [blame] | 40 | #include <net/tcp_states.h> |
| 41 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | #include <linux/seq_file.h> |
| 43 | |
Arnaldo Carvalho de Melo | 6e04e02 | 2005-08-09 20:07:35 -0700 | [diff] [blame] | 44 | extern struct inet_hashinfo tcp_hashinfo; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 46 | extern atomic_t tcp_orphan_count; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | extern void tcp_time_wait(struct sock *sk, int state, int timeo); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | #define MAX_TCP_HEADER (128 + MAX_HEADER) |
| 50 | |
| 51 | /* |
| 52 | * Never offer a window over 32767 without using window scaling. Some |
| 53 | * poor stacks do signed 16bit maths! |
| 54 | */ |
| 55 | #define MAX_TCP_WINDOW 32767U |
| 56 | |
| 57 | /* Minimal accepted MSS. It is (60+60+8) - (20+20). */ |
| 58 | #define TCP_MIN_MSS 88U |
| 59 | |
| 60 | /* Minimal RCV_MSS. */ |
| 61 | #define TCP_MIN_RCVMSS 536U |
| 62 | |
John Heffner | 5d424d5 | 2006-03-20 17:53:41 -0800 | [diff] [blame] | 63 | /* The least MTU to use for probing */ |
| 64 | #define TCP_BASE_MSS 512 |
| 65 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | /* After receiving this amount of duplicate ACKs fast retransmit starts. */ |
| 67 | #define TCP_FASTRETRANS_THRESH 3 |
| 68 | |
| 69 | /* Maximal reordering. */ |
| 70 | #define TCP_MAX_REORDERING 127 |
| 71 | |
| 72 | /* Maximal number of ACKs sent quickly to accelerate slow-start. */ |
| 73 | #define TCP_MAX_QUICKACKS 16U |
| 74 | |
| 75 | /* urg_data states */ |
| 76 | #define TCP_URG_VALID 0x0100 |
| 77 | #define TCP_URG_NOTYET 0x0200 |
| 78 | #define TCP_URG_READ 0x0400 |
| 79 | |
| 80 | #define TCP_RETR1 3 /* |
| 81 | * This is how many retries it does before it |
| 82 | * tries to figure out if the gateway is |
| 83 | * down. Minimal RFC value is 3; it corresponds |
| 84 | * to ~3sec-8min depending on RTO. |
| 85 | */ |
| 86 | |
| 87 | #define TCP_RETR2 15 /* |
| 88 | * This should take at least |
| 89 | * 90 minutes to time out. |
| 90 | * RFC1122 says that the limit is 100 sec. |
| 91 | * 15 is ~13-30min depending on RTO. |
| 92 | */ |
| 93 | |
| 94 | #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] | 95 | * connection: ~180sec is RFC minimum */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | |
| 97 | #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] | 98 | * connection: ~180sec is RFC minimum */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | |
| 100 | |
| 101 | #define TCP_ORPHAN_RETRIES 7 /* number of times to retry on an orphaned |
| 102 | * socket. 7 is ~50sec-16min. |
| 103 | */ |
| 104 | |
| 105 | |
| 106 | #define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT |
| 107 | * state, about 60 seconds */ |
| 108 | #define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN |
| 109 | /* BSD style FIN_WAIT2 deadlock breaker. |
| 110 | * It used to be 3min, new value is 60sec, |
| 111 | * to combine FIN-WAIT-2 timeout with |
| 112 | * TIME-WAIT timer. |
| 113 | */ |
| 114 | |
| 115 | #define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */ |
| 116 | #if HZ >= 100 |
| 117 | #define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */ |
| 118 | #define TCP_ATO_MIN ((unsigned)(HZ/25)) |
| 119 | #else |
| 120 | #define TCP_DELACK_MIN 4U |
| 121 | #define TCP_ATO_MIN 4U |
| 122 | #endif |
| 123 | #define TCP_RTO_MAX ((unsigned)(120*HZ)) |
| 124 | #define TCP_RTO_MIN ((unsigned)(HZ/5)) |
| 125 | #define TCP_TIMEOUT_INIT ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value */ |
| 126 | |
| 127 | #define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes |
| 128 | * for local resources. |
| 129 | */ |
| 130 | |
| 131 | #define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */ |
| 132 | #define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */ |
| 133 | #define TCP_KEEPALIVE_INTVL (75*HZ) |
| 134 | |
| 135 | #define MAX_TCP_KEEPIDLE 32767 |
| 136 | #define MAX_TCP_KEEPINTVL 32767 |
| 137 | #define MAX_TCP_KEEPCNT 127 |
| 138 | #define MAX_TCP_SYNCNT 127 |
| 139 | |
| 140 | #define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */ |
| 141 | #define TCP_SYNQ_HSIZE 512 /* Size of SYNACK hash table */ |
| 142 | |
| 143 | #define TCP_PAWS_24DAYS (60 * 60 * 24 * 24) |
| 144 | #define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated |
| 145 | * after this time. It should be equal |
| 146 | * (or greater than) TCP_TIMEWAIT_LEN |
| 147 | * to provide reliability equal to one |
| 148 | * provided by timewait state. |
| 149 | */ |
| 150 | #define TCP_PAWS_WINDOW 1 /* Replay window for per-host |
| 151 | * timestamps. It must be less than |
| 152 | * minimal timewait lifetime. |
| 153 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 154 | /* |
| 155 | * TCP option |
| 156 | */ |
| 157 | |
| 158 | #define TCPOPT_NOP 1 /* Padding */ |
| 159 | #define TCPOPT_EOL 0 /* End of options */ |
| 160 | #define TCPOPT_MSS 2 /* Segment size negotiating */ |
| 161 | #define TCPOPT_WINDOW 3 /* Window scaling */ |
| 162 | #define TCPOPT_SACK_PERM 4 /* SACK Permitted */ |
| 163 | #define TCPOPT_SACK 5 /* SACK Block */ |
| 164 | #define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */ |
| 165 | |
| 166 | /* |
| 167 | * TCP option lengths |
| 168 | */ |
| 169 | |
| 170 | #define TCPOLEN_MSS 4 |
| 171 | #define TCPOLEN_WINDOW 3 |
| 172 | #define TCPOLEN_SACK_PERM 2 |
| 173 | #define TCPOLEN_TIMESTAMP 10 |
| 174 | |
| 175 | /* But this is what stacks really send out. */ |
| 176 | #define TCPOLEN_TSTAMP_ALIGNED 12 |
| 177 | #define TCPOLEN_WSCALE_ALIGNED 4 |
| 178 | #define TCPOLEN_SACKPERM_ALIGNED 4 |
| 179 | #define TCPOLEN_SACK_BASE 2 |
| 180 | #define TCPOLEN_SACK_BASE_ALIGNED 4 |
| 181 | #define TCPOLEN_SACK_PERBLOCK 8 |
| 182 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | /* Flags in tp->nonagle */ |
| 184 | #define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */ |
| 185 | #define TCP_NAGLE_CORK 2 /* Socket is corked */ |
Stephen Hemminger | caa20d9a | 2005-11-10 17:13:47 -0800 | [diff] [blame] | 186 | #define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 187 | |
Arnaldo Carvalho de Melo | 295ff7e | 2005-08-09 20:44:40 -0700 | [diff] [blame] | 188 | extern struct inet_timewait_death_row tcp_death_row; |
| 189 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 190 | /* sysctl variables for tcp */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | extern int sysctl_tcp_timestamps; |
| 192 | extern int sysctl_tcp_window_scaling; |
| 193 | extern int sysctl_tcp_sack; |
| 194 | extern int sysctl_tcp_fin_timeout; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | extern int sysctl_tcp_keepalive_time; |
| 196 | extern int sysctl_tcp_keepalive_probes; |
| 197 | extern int sysctl_tcp_keepalive_intvl; |
| 198 | extern int sysctl_tcp_syn_retries; |
| 199 | extern int sysctl_tcp_synack_retries; |
| 200 | extern int sysctl_tcp_retries1; |
| 201 | extern int sysctl_tcp_retries2; |
| 202 | extern int sysctl_tcp_orphan_retries; |
| 203 | extern int sysctl_tcp_syncookies; |
| 204 | extern int sysctl_tcp_retrans_collapse; |
| 205 | extern int sysctl_tcp_stdurg; |
| 206 | extern int sysctl_tcp_rfc1337; |
| 207 | extern int sysctl_tcp_abort_on_overflow; |
| 208 | extern int sysctl_tcp_max_orphans; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 209 | extern int sysctl_tcp_fack; |
| 210 | extern int sysctl_tcp_reordering; |
| 211 | extern int sysctl_tcp_ecn; |
| 212 | extern int sysctl_tcp_dsack; |
| 213 | extern int sysctl_tcp_mem[3]; |
| 214 | extern int sysctl_tcp_wmem[3]; |
| 215 | extern int sysctl_tcp_rmem[3]; |
| 216 | extern int sysctl_tcp_app_win; |
| 217 | extern int sysctl_tcp_adv_win_scale; |
| 218 | extern int sysctl_tcp_tw_reuse; |
| 219 | extern int sysctl_tcp_frto; |
| 220 | extern int sysctl_tcp_low_latency; |
Chris Leech | 9593782 | 2006-05-23 18:02:55 -0700 | [diff] [blame] | 221 | extern int sysctl_tcp_dma_copybreak; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 222 | extern int sysctl_tcp_nometrics_save; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 223 | extern int sysctl_tcp_moderate_rcvbuf; |
| 224 | extern int sysctl_tcp_tso_win_divisor; |
Stephen Hemminger | 9772efb | 2005-11-10 17:09:53 -0800 | [diff] [blame] | 225 | extern int sysctl_tcp_abc; |
John Heffner | 5d424d5 | 2006-03-20 17:53:41 -0800 | [diff] [blame] | 226 | extern int sysctl_tcp_mtu_probing; |
| 227 | extern int sysctl_tcp_base_mss; |
Rick Jones | 15d99e0 | 2006-03-20 22:40:29 -0800 | [diff] [blame] | 228 | extern int sysctl_tcp_workaround_signed_windows; |
David S. Miller | 35089bb | 2006-06-13 22:33:04 -0700 | [diff] [blame] | 229 | extern int sysctl_tcp_slow_start_after_idle; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | |
| 231 | extern atomic_t tcp_memory_allocated; |
| 232 | extern atomic_t tcp_sockets_allocated; |
| 233 | extern int tcp_memory_pressure; |
| 234 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | * The next routines deal with comparing 32 bit unsigned ints |
| 237 | * and worry about wraparound (automatic with unsigned arithmetic). |
| 238 | */ |
| 239 | |
| 240 | static inline int before(__u32 seq1, __u32 seq2) |
| 241 | { |
| 242 | return (__s32)(seq1-seq2) < 0; |
| 243 | } |
| 244 | |
| 245 | static inline int after(__u32 seq1, __u32 seq2) |
| 246 | { |
| 247 | return (__s32)(seq2-seq1) < 0; |
| 248 | } |
| 249 | |
| 250 | |
| 251 | /* is s2<=s1<=s3 ? */ |
| 252 | static inline int between(__u32 seq1, __u32 seq2, __u32 seq3) |
| 253 | { |
| 254 | return seq3 - seq2 >= seq1 - seq2; |
| 255 | } |
| 256 | |
| 257 | |
| 258 | extern struct proto tcp_prot; |
| 259 | |
| 260 | DECLARE_SNMP_STAT(struct tcp_mib, tcp_statistics); |
| 261 | #define TCP_INC_STATS(field) SNMP_INC_STATS(tcp_statistics, field) |
| 262 | #define TCP_INC_STATS_BH(field) SNMP_INC_STATS_BH(tcp_statistics, field) |
| 263 | #define TCP_INC_STATS_USER(field) SNMP_INC_STATS_USER(tcp_statistics, field) |
| 264 | #define TCP_DEC_STATS(field) SNMP_DEC_STATS(tcp_statistics, field) |
| 265 | #define TCP_ADD_STATS_BH(field, val) SNMP_ADD_STATS_BH(tcp_statistics, field, val) |
| 266 | #define TCP_ADD_STATS_USER(field, val) SNMP_ADD_STATS_USER(tcp_statistics, field, val) |
| 267 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | extern void tcp_v4_err(struct sk_buff *skb, u32); |
| 269 | |
| 270 | extern void tcp_shutdown (struct sock *sk, int how); |
| 271 | |
| 272 | extern int tcp_v4_rcv(struct sk_buff *skb); |
| 273 | |
| 274 | extern int tcp_v4_remember_stamp(struct sock *sk); |
| 275 | |
Arnaldo Carvalho de Melo | 8feaf0c | 2005-08-09 20:09:30 -0700 | [diff] [blame] | 276 | extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | |
| 278 | extern int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, |
| 279 | struct msghdr *msg, size_t size); |
| 280 | extern ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags); |
| 281 | |
| 282 | extern int tcp_ioctl(struct sock *sk, |
| 283 | int cmd, |
| 284 | unsigned long arg); |
| 285 | |
| 286 | extern int tcp_rcv_state_process(struct sock *sk, |
| 287 | struct sk_buff *skb, |
| 288 | struct tcphdr *th, |
| 289 | unsigned len); |
| 290 | |
| 291 | extern int tcp_rcv_established(struct sock *sk, |
| 292 | struct sk_buff *skb, |
| 293 | struct tcphdr *th, |
| 294 | unsigned len); |
| 295 | |
| 296 | extern void tcp_rcv_space_adjust(struct sock *sk); |
| 297 | |
Chris Leech | 0e4b499 | 2006-05-23 18:00:16 -0700 | [diff] [blame] | 298 | extern void tcp_cleanup_rbuf(struct sock *sk, int copied); |
| 299 | |
Arnaldo Carvalho de Melo | 6d6ee43 | 2005-12-13 23:25:19 -0800 | [diff] [blame] | 300 | extern int tcp_twsk_unique(struct sock *sk, |
| 301 | struct sock *sktw, void *twp); |
| 302 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 303 | static inline void tcp_dec_quickack_mode(struct sock *sk, |
| 304 | const unsigned int pkts) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 305 | { |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 306 | struct inet_connection_sock *icsk = inet_csk(sk); |
David S. Miller | fc6415b | 2005-07-05 15:17:45 -0700 | [diff] [blame] | 307 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 308 | if (icsk->icsk_ack.quick) { |
| 309 | if (pkts >= icsk->icsk_ack.quick) { |
| 310 | icsk->icsk_ack.quick = 0; |
David S. Miller | fc6415b | 2005-07-05 15:17:45 -0700 | [diff] [blame] | 311 | /* Leaving quickack mode we deflate ATO. */ |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 312 | icsk->icsk_ack.ato = TCP_ATO_MIN; |
David S. Miller | fc6415b | 2005-07-05 15:17:45 -0700 | [diff] [blame] | 313 | } else |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 314 | icsk->icsk_ack.quick -= pkts; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 315 | } |
| 316 | } |
| 317 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 318 | extern void tcp_enter_quickack_mode(struct sock *sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 319 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 320 | static inline void tcp_clear_options(struct tcp_options_received *rx_opt) |
| 321 | { |
| 322 | rx_opt->tstamp_ok = rx_opt->sack_ok = rx_opt->wscale_ok = rx_opt->snd_wscale = 0; |
| 323 | } |
| 324 | |
| 325 | enum tcp_tw_status |
| 326 | { |
| 327 | TCP_TW_SUCCESS = 0, |
| 328 | TCP_TW_RST = 1, |
| 329 | TCP_TW_ACK = 2, |
| 330 | TCP_TW_SYN = 3 |
| 331 | }; |
| 332 | |
| 333 | |
Arnaldo Carvalho de Melo | 8feaf0c | 2005-08-09 20:09:30 -0700 | [diff] [blame] | 334 | extern enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | struct sk_buff *skb, |
Arnaldo Carvalho de Melo | 8feaf0c | 2005-08-09 20:09:30 -0700 | [diff] [blame] | 336 | const struct tcphdr *th); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | |
| 338 | extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb, |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 339 | struct request_sock *req, |
| 340 | struct request_sock **prev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 341 | extern int tcp_child_process(struct sock *parent, |
| 342 | struct sock *child, |
| 343 | struct sk_buff *skb); |
| 344 | extern void tcp_enter_frto(struct sock *sk); |
| 345 | extern void tcp_enter_loss(struct sock *sk, int how); |
| 346 | extern void tcp_clear_retrans(struct tcp_sock *tp); |
| 347 | extern void tcp_update_metrics(struct sock *sk); |
| 348 | |
| 349 | extern void tcp_close(struct sock *sk, |
| 350 | long timeout); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 351 | extern unsigned int tcp_poll(struct file * file, struct socket *sock, struct poll_table_struct *wait); |
| 352 | |
| 353 | extern int tcp_getsockopt(struct sock *sk, int level, |
| 354 | int optname, |
| 355 | char __user *optval, |
| 356 | int __user *optlen); |
| 357 | extern int tcp_setsockopt(struct sock *sk, int level, |
| 358 | int optname, char __user *optval, |
| 359 | int optlen); |
Dmitry Mishin | 3fdadf7 | 2006-03-20 22:45:21 -0800 | [diff] [blame] | 360 | extern int compat_tcp_getsockopt(struct sock *sk, |
| 361 | int level, int optname, |
| 362 | char __user *optval, int __user *optlen); |
| 363 | extern int compat_tcp_setsockopt(struct sock *sk, |
| 364 | int level, int optname, |
| 365 | char __user *optval, int optlen); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | extern void tcp_set_keepalive(struct sock *sk, int val); |
| 367 | extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, |
| 368 | struct msghdr *msg, |
| 369 | size_t len, int nonblock, |
| 370 | int flags, int *addr_len); |
| 371 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 372 | extern void tcp_parse_options(struct sk_buff *skb, |
| 373 | struct tcp_options_received *opt_rx, |
| 374 | int estab); |
| 375 | |
| 376 | /* |
| 377 | * TCP v4 functions exported for the inet6 API |
| 378 | */ |
| 379 | |
Arnaldo Carvalho de Melo | 8292a17 | 2005-12-13 23:15:52 -0800 | [diff] [blame] | 380 | extern void tcp_v4_send_check(struct sock *sk, int len, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 381 | struct sk_buff *skb); |
| 382 | |
| 383 | extern int tcp_v4_conn_request(struct sock *sk, |
| 384 | struct sk_buff *skb); |
| 385 | |
| 386 | extern struct sock * tcp_create_openreq_child(struct sock *sk, |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 387 | struct request_sock *req, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | struct sk_buff *skb); |
| 389 | |
| 390 | extern struct sock * tcp_v4_syn_recv_sock(struct sock *sk, |
| 391 | struct sk_buff *skb, |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 392 | struct request_sock *req, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 393 | struct dst_entry *dst); |
| 394 | |
| 395 | extern int tcp_v4_do_rcv(struct sock *sk, |
| 396 | struct sk_buff *skb); |
| 397 | |
| 398 | extern int tcp_v4_connect(struct sock *sk, |
| 399 | struct sockaddr *uaddr, |
| 400 | int addr_len); |
| 401 | |
| 402 | extern int tcp_connect(struct sock *sk); |
| 403 | |
| 404 | extern struct sk_buff * tcp_make_synack(struct sock *sk, |
| 405 | struct dst_entry *dst, |
Arnaldo Carvalho de Melo | 60236fd | 2005-06-18 22:47:21 -0700 | [diff] [blame] | 406 | struct request_sock *req); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 407 | |
| 408 | extern int tcp_disconnect(struct sock *sk, int flags); |
| 409 | |
| 410 | extern void tcp_unhash(struct sock *sk); |
| 411 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 412 | /* From syncookies.c */ |
| 413 | extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb, |
| 414 | struct ip_options *opt); |
| 415 | extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb, |
| 416 | __u16 *mss); |
| 417 | |
| 418 | /* tcp_output.c */ |
| 419 | |
David S. Miller | f6302d1 | 2005-07-05 15:18:03 -0700 | [diff] [blame] | 420 | extern void __tcp_push_pending_frames(struct sock *sk, struct tcp_sock *tp, |
David S. Miller | a2e2a59 | 2005-07-05 15:19:23 -0700 | [diff] [blame] | 421 | unsigned int cur_mss, int nonagle); |
David S. Miller | f6302d1 | 2005-07-05 15:18:03 -0700 | [diff] [blame] | 422 | extern int tcp_may_send_now(struct sock *sk, struct tcp_sock *tp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | extern int tcp_retransmit_skb(struct sock *, struct sk_buff *); |
| 424 | extern void tcp_xmit_retransmit_queue(struct sock *); |
| 425 | extern void tcp_simple_retransmit(struct sock *); |
| 426 | extern int tcp_trim_head(struct sock *, struct sk_buff *, u32); |
David S. Miller | 6475be1 | 2005-09-01 22:47:01 -0700 | [diff] [blame] | 427 | extern int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | |
| 429 | extern void tcp_send_probe0(struct sock *); |
| 430 | extern void tcp_send_partial(struct sock *); |
| 431 | extern int tcp_write_wakeup(struct sock *); |
| 432 | extern void tcp_send_fin(struct sock *sk); |
Al Viro | dd0fc66 | 2005-10-07 07:46:04 +0100 | [diff] [blame] | 433 | extern void tcp_send_active_reset(struct sock *sk, gfp_t priority); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | extern int tcp_send_synack(struct sock *); |
David S. Miller | c1b4a7e | 2005-07-05 15:24:38 -0700 | [diff] [blame] | 435 | extern void tcp_push_one(struct sock *, unsigned int mss_now); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | extern void tcp_send_ack(struct sock *sk); |
| 437 | extern void tcp_send_delayed_ack(struct sock *sk); |
| 438 | |
David S. Miller | a762a98 | 2005-07-05 15:18:51 -0700 | [diff] [blame] | 439 | /* tcp_input.c */ |
| 440 | extern void tcp_cwnd_application_limited(struct sock *sk); |
| 441 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | /* tcp_timer.c */ |
| 443 | extern void tcp_init_xmit_timers(struct sock *); |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 444 | static inline void tcp_clear_xmit_timers(struct sock *sk) |
| 445 | { |
| 446 | inet_csk_clear_xmit_timers(sk); |
| 447 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | extern unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu); |
| 450 | extern unsigned int tcp_current_mss(struct sock *sk, int large); |
| 451 | |
Arnaldo Carvalho de Melo | 17b085e | 2005-08-12 12:59:17 -0300 | [diff] [blame] | 452 | /* tcp.c */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | extern void tcp_get_info(struct sock *, struct tcp_info *); |
| 454 | |
| 455 | /* Read 'sendfile()'-style from a TCP socket */ |
| 456 | typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *, |
| 457 | unsigned int, size_t); |
| 458 | extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, |
| 459 | sk_read_actor_t recv_actor); |
| 460 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 461 | extern void tcp_initialize_rcv_mss(struct sock *sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | |
John Heffner | 5d424d5 | 2006-03-20 17:53:41 -0800 | [diff] [blame] | 463 | extern int tcp_mtu_to_mss(struct sock *sk, int pmtu); |
| 464 | extern int tcp_mss_to_mtu(struct sock *sk, int mss); |
| 465 | extern void tcp_mtup_init(struct sock *sk); |
| 466 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 467 | 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] | 468 | { |
| 469 | tp->pred_flags = htonl((tp->tcp_header_len << 26) | |
| 470 | ntohl(TCP_FLAG_ACK) | |
| 471 | snd_wnd); |
| 472 | } |
| 473 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 474 | static inline void tcp_fast_path_on(struct tcp_sock *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 475 | { |
| 476 | __tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale); |
| 477 | } |
| 478 | |
| 479 | static inline void tcp_fast_path_check(struct sock *sk, struct tcp_sock *tp) |
| 480 | { |
David S. Miller | b03efcf | 2005-07-08 14:57:23 -0700 | [diff] [blame] | 481 | if (skb_queue_empty(&tp->out_of_order_queue) && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | tp->rcv_wnd && |
| 483 | atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf && |
| 484 | !tp->urg_data) |
| 485 | tcp_fast_path_on(tp); |
| 486 | } |
| 487 | |
| 488 | /* Compute the actual receive window we are currently advertising. |
| 489 | * Rcv_nxt can be after the window if our peer push more data |
| 490 | * than the offered window. |
| 491 | */ |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 492 | static inline u32 tcp_receive_window(const struct tcp_sock *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 493 | { |
| 494 | s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt; |
| 495 | |
| 496 | if (win < 0) |
| 497 | win = 0; |
| 498 | return (u32) win; |
| 499 | } |
| 500 | |
| 501 | /* Choose a new window, without checks for shrinking, and without |
| 502 | * scaling applied to the result. The caller does these things |
| 503 | * if necessary. This is a "raw" window selection. |
| 504 | */ |
| 505 | extern u32 __tcp_select_window(struct sock *sk); |
| 506 | |
| 507 | /* TCP timestamps are only 32-bits, this causes a slight |
| 508 | * complication on 64-bit systems since we store a snapshot |
Stephen Hemminger | 31f3426 | 2005-11-15 15:17:10 -0800 | [diff] [blame] | 509 | * of jiffies in the buffer control blocks below. We decided |
| 510 | * 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] | 511 | * casts with the following macro. |
| 512 | */ |
| 513 | #define tcp_time_stamp ((__u32)(jiffies)) |
| 514 | |
Stephen Hemminger | caa20d9a | 2005-11-10 17:13:47 -0800 | [diff] [blame] | 515 | /* This is what the send packet queuing engine uses to pass |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 516 | * TCP per-packet control information to the transmission |
| 517 | * code. We also store the host-order sequence numbers in |
| 518 | * here too. This is 36 bytes on 32-bit architectures, |
| 519 | * 40 bytes on 64-bit machines, if this grows please adjust |
| 520 | * skbuff.h:skbuff->cb[xxx] size appropriately. |
| 521 | */ |
| 522 | struct tcp_skb_cb { |
| 523 | union { |
| 524 | struct inet_skb_parm h4; |
| 525 | #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) |
| 526 | struct inet6_skb_parm h6; |
| 527 | #endif |
| 528 | } header; /* For incoming frames */ |
| 529 | __u32 seq; /* Starting sequence number */ |
| 530 | __u32 end_seq; /* SEQ + FIN + SYN + datalen */ |
| 531 | __u32 when; /* used to compute rtt's */ |
| 532 | __u8 flags; /* TCP header flags. */ |
| 533 | |
| 534 | /* NOTE: These must match up to the flags byte in a |
| 535 | * real TCP header. |
| 536 | */ |
| 537 | #define TCPCB_FLAG_FIN 0x01 |
| 538 | #define TCPCB_FLAG_SYN 0x02 |
| 539 | #define TCPCB_FLAG_RST 0x04 |
| 540 | #define TCPCB_FLAG_PSH 0x08 |
| 541 | #define TCPCB_FLAG_ACK 0x10 |
| 542 | #define TCPCB_FLAG_URG 0x20 |
| 543 | #define TCPCB_FLAG_ECE 0x40 |
| 544 | #define TCPCB_FLAG_CWR 0x80 |
| 545 | |
| 546 | __u8 sacked; /* State flags for SACK/FACK. */ |
| 547 | #define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */ |
| 548 | #define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */ |
| 549 | #define TCPCB_LOST 0x04 /* SKB is lost */ |
| 550 | #define TCPCB_TAGBITS 0x07 /* All tag bits */ |
| 551 | |
| 552 | #define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */ |
| 553 | #define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS) |
| 554 | |
Stephen Hemminger | caa20d9a | 2005-11-10 17:13:47 -0800 | [diff] [blame] | 555 | #define TCPCB_URG 0x20 /* Urgent pointer advanced here */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 556 | |
| 557 | #define TCPCB_AT_TAIL (TCPCB_URG) |
| 558 | |
| 559 | __u16 urg_ptr; /* Valid w/URG flags is set. */ |
| 560 | __u32 ack_seq; /* Sequence number ACK'd */ |
| 561 | }; |
| 562 | |
| 563 | #define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0])) |
| 564 | |
| 565 | #include <net/tcp_ecn.h> |
| 566 | |
| 567 | /* Due to TSO, an SKB can be composed of multiple actual |
| 568 | * packets. To keep these tracked properly, we use this. |
| 569 | */ |
| 570 | static inline int tcp_skb_pcount(const struct sk_buff *skb) |
| 571 | { |
Herbert Xu | 7967168 | 2006-06-22 02:40:14 -0700 | [diff] [blame] | 572 | return skb_shinfo(skb)->gso_segs; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 573 | } |
| 574 | |
| 575 | /* This is valid iff tcp_skb_pcount() > 1. */ |
| 576 | static inline int tcp_skb_mss(const struct sk_buff *skb) |
| 577 | { |
Herbert Xu | 7967168 | 2006-06-22 02:40:14 -0700 | [diff] [blame] | 578 | return skb_shinfo(skb)->gso_size; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 579 | } |
| 580 | |
| 581 | static inline void tcp_dec_pcount_approx(__u32 *count, |
| 582 | const struct sk_buff *skb) |
| 583 | { |
| 584 | if (*count) { |
| 585 | *count -= tcp_skb_pcount(skb); |
| 586 | if ((int)*count < 0) |
| 587 | *count = 0; |
| 588 | } |
| 589 | } |
| 590 | |
| 591 | static inline void tcp_packets_out_inc(struct sock *sk, |
| 592 | struct tcp_sock *tp, |
| 593 | const struct sk_buff *skb) |
| 594 | { |
| 595 | int orig = tp->packets_out; |
| 596 | |
| 597 | tp->packets_out += tcp_skb_pcount(skb); |
| 598 | if (!orig) |
Arnaldo Carvalho de Melo | 3f421ba | 2005-08-09 20:11:08 -0700 | [diff] [blame] | 599 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, |
| 600 | inet_csk(sk)->icsk_rto, TCP_RTO_MAX); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 601 | } |
| 602 | |
| 603 | static inline void tcp_packets_out_dec(struct tcp_sock *tp, |
| 604 | const struct sk_buff *skb) |
| 605 | { |
| 606 | tp->packets_out -= tcp_skb_pcount(skb); |
| 607 | } |
| 608 | |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 609 | /* Events passed to congestion control interface */ |
| 610 | enum tcp_ca_event { |
| 611 | CA_EVENT_TX_START, /* first transmit when no packets in flight */ |
| 612 | CA_EVENT_CWND_RESTART, /* congestion window restart */ |
| 613 | CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */ |
| 614 | CA_EVENT_FRTO, /* fast recovery timeout */ |
| 615 | CA_EVENT_LOSS, /* loss timeout */ |
| 616 | CA_EVENT_FAST_ACK, /* in sequence ack */ |
| 617 | CA_EVENT_SLOW_ACK, /* other ack */ |
| 618 | }; |
| 619 | |
| 620 | /* |
| 621 | * Interface for adding new TCP congestion control handlers |
| 622 | */ |
| 623 | #define TCP_CA_NAME_MAX 16 |
| 624 | struct tcp_congestion_ops { |
| 625 | struct list_head list; |
| 626 | |
| 627 | /* initialize private data (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 628 | void (*init)(struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 629 | /* cleanup private data (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 630 | void (*release)(struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 631 | |
| 632 | /* return slow start threshold (required) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 633 | u32 (*ssthresh)(struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 634 | /* lower bound for congestion window (optional) */ |
Stephen Hemminger | 72dc5b9 | 2006-06-05 17:30:08 -0700 | [diff] [blame] | 635 | u32 (*min_cwnd)(const struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 636 | /* do new cwnd calculation (required) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 637 | void (*cong_avoid)(struct sock *sk, u32 ack, |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 638 | u32 rtt, u32 in_flight, int good_ack); |
| 639 | /* round trip time sample per acked packet (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 640 | void (*rtt_sample)(struct sock *sk, u32 usrtt); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 641 | /* call before changing ca_state (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 642 | void (*set_state)(struct sock *sk, u8 new_state); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 643 | /* call when cwnd event occurs (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 644 | void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 645 | /* new value of cwnd after loss (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 646 | u32 (*undo_cwnd)(struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 647 | /* hook for packet ack accounting (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 648 | void (*pkts_acked)(struct sock *sk, u32 num_acked); |
Arnaldo Carvalho de Melo | 73c1f4a | 2005-08-12 12:51:49 -0300 | [diff] [blame] | 649 | /* get info for inet_diag (optional) */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 650 | void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 651 | |
| 652 | char name[TCP_CA_NAME_MAX]; |
| 653 | struct module *owner; |
| 654 | }; |
| 655 | |
| 656 | extern int tcp_register_congestion_control(struct tcp_congestion_ops *type); |
| 657 | extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type); |
| 658 | |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 659 | extern void tcp_init_congestion_control(struct sock *sk); |
| 660 | extern void tcp_cleanup_congestion_control(struct sock *sk); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 661 | extern int tcp_set_default_congestion_control(const char *name); |
| 662 | extern void tcp_get_default_congestion_control(char *name); |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 663 | extern int tcp_set_congestion_control(struct sock *sk, const char *name); |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 664 | extern void tcp_slow_start(struct tcp_sock *tp); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 665 | |
Stephen Hemminger | 5f8ef48 | 2005-06-23 20:37:36 -0700 | [diff] [blame] | 666 | extern struct tcp_congestion_ops tcp_init_congestion_ops; |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 667 | extern u32 tcp_reno_ssthresh(struct sock *sk); |
| 668 | extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack, |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 669 | u32 rtt, u32 in_flight, int flag); |
Stephen Hemminger | 72dc5b9 | 2006-06-05 17:30:08 -0700 | [diff] [blame] | 670 | extern u32 tcp_reno_min_cwnd(const struct sock *sk); |
David S. Miller | a8acfba | 2005-06-23 23:45:02 -0700 | [diff] [blame] | 671 | extern struct tcp_congestion_ops tcp_reno; |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 672 | |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 673 | 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] | 674 | { |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 675 | struct inet_connection_sock *icsk = inet_csk(sk); |
| 676 | |
| 677 | if (icsk->icsk_ca_ops->set_state) |
| 678 | icsk->icsk_ca_ops->set_state(sk, ca_state); |
| 679 | icsk->icsk_ca_state = ca_state; |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 680 | } |
| 681 | |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 682 | 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] | 683 | { |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 684 | const struct inet_connection_sock *icsk = inet_csk(sk); |
| 685 | |
| 686 | if (icsk->icsk_ca_ops->cwnd_event) |
| 687 | icsk->icsk_ca_ops->cwnd_event(sk, event); |
Stephen Hemminger | 317a76f | 2005-06-23 12:19:55 -0700 | [diff] [blame] | 688 | } |
| 689 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 690 | /* This determines how many packets are "in the network" to the best |
| 691 | * of our knowledge. In many cases it is conservative, but where |
| 692 | * detailed information is available from the receiver (via SACK |
| 693 | * blocks etc.) we can make more aggressive calculations. |
| 694 | * |
| 695 | * Use this for decisions involving congestion control, use just |
| 696 | * tp->packets_out to determine if the send queue is empty or not. |
| 697 | * |
| 698 | * Read this equation as: |
| 699 | * |
| 700 | * "Packets sent once on transmission queue" MINUS |
| 701 | * "Packets left network, but not honestly ACKed yet" PLUS |
| 702 | * "Packets fast retransmitted" |
| 703 | */ |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 704 | 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] | 705 | { |
| 706 | return (tp->packets_out - tp->left_out + tp->retrans_out); |
| 707 | } |
| 708 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 709 | /* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd. |
| 710 | * The exception is rate halving phase, when cwnd is decreasing towards |
| 711 | * ssthresh. |
| 712 | */ |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 713 | static inline __u32 tcp_current_ssthresh(const struct sock *sk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 714 | { |
Arnaldo Carvalho de Melo | 6687e98 | 2005-08-10 04:03:31 -0300 | [diff] [blame] | 715 | const struct tcp_sock *tp = tcp_sk(sk); |
| 716 | 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] | 717 | return tp->snd_ssthresh; |
| 718 | else |
| 719 | return max(tp->snd_ssthresh, |
| 720 | ((tp->snd_cwnd >> 1) + |
| 721 | (tp->snd_cwnd >> 2))); |
| 722 | } |
| 723 | |
| 724 | static inline void tcp_sync_left_out(struct tcp_sock *tp) |
| 725 | { |
| 726 | if (tp->rx_opt.sack_ok && |
| 727 | (tp->sacked_out >= tp->packets_out - tp->lost_out)) |
| 728 | tp->sacked_out = tp->packets_out - tp->lost_out; |
| 729 | tp->left_out = tp->sacked_out + tp->lost_out; |
| 730 | } |
| 731 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 732 | extern void tcp_enter_cwr(struct sock *sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 733 | extern __u32 tcp_init_cwnd(struct tcp_sock *tp, struct dst_entry *dst); |
| 734 | |
| 735 | /* Slow start with delack produces 3 packets of burst, so that |
| 736 | * it is safe "de facto". |
| 737 | */ |
| 738 | static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp) |
| 739 | { |
| 740 | return 3; |
| 741 | } |
| 742 | |
Stephen Hemminger | f4805ed | 2005-11-10 16:53:30 -0800 | [diff] [blame] | 743 | /* RFC2861 Check whether we are limited by application or congestion window |
| 744 | * This is the inverse of cwnd check in tcp_tso_should_defer |
| 745 | */ |
| 746 | static inline int tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight) |
| 747 | { |
| 748 | const struct tcp_sock *tp = tcp_sk(sk); |
| 749 | u32 left; |
| 750 | |
| 751 | if (in_flight >= tp->snd_cwnd) |
| 752 | return 1; |
| 753 | |
Herbert Xu | bcd7611 | 2006-06-30 13:36:35 -0700 | [diff] [blame] | 754 | if (!sk_can_gso(sk)) |
Stephen Hemminger | f4805ed | 2005-11-10 16:53:30 -0800 | [diff] [blame] | 755 | return 0; |
| 756 | |
| 757 | left = tp->snd_cwnd - in_flight; |
| 758 | if (sysctl_tcp_tso_win_divisor) |
| 759 | return left * sysctl_tcp_tso_win_divisor < tp->snd_cwnd; |
| 760 | else |
| 761 | return left <= tcp_max_burst(tp); |
| 762 | } |
| 763 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 764 | static inline void tcp_minshall_update(struct tcp_sock *tp, int mss, |
| 765 | const struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 766 | { |
| 767 | if (skb->len < mss) |
| 768 | tp->snd_sml = TCP_SKB_CB(skb)->end_seq; |
| 769 | } |
| 770 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 771 | static inline void tcp_check_probe_timer(struct sock *sk, struct tcp_sock *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 772 | { |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 773 | const struct inet_connection_sock *icsk = inet_csk(sk); |
| 774 | if (!tp->packets_out && !icsk->icsk_pending) |
Arnaldo Carvalho de Melo | 3f421ba | 2005-08-09 20:11:08 -0700 | [diff] [blame] | 775 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0, |
| 776 | icsk->icsk_rto, TCP_RTO_MAX); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 777 | } |
| 778 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 779 | static inline void tcp_push_pending_frames(struct sock *sk, |
| 780 | struct tcp_sock *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 781 | { |
| 782 | __tcp_push_pending_frames(sk, tp, tcp_current_mss(sk, 1), tp->nonagle); |
| 783 | } |
| 784 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 785 | static inline void tcp_init_wl(struct tcp_sock *tp, u32 ack, u32 seq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 786 | { |
| 787 | tp->snd_wl1 = seq; |
| 788 | } |
| 789 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 790 | static inline void tcp_update_wl(struct tcp_sock *tp, u32 ack, u32 seq) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 791 | { |
| 792 | tp->snd_wl1 = seq; |
| 793 | } |
| 794 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 795 | /* |
| 796 | * Calculate(/check) TCP checksum |
| 797 | */ |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 798 | static inline u16 tcp_v4_check(struct tcphdr *th, int len, |
| 799 | unsigned long saddr, unsigned long daddr, |
| 800 | unsigned long base) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 801 | { |
| 802 | return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base); |
| 803 | } |
| 804 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 805 | static inline int __tcp_checksum_complete(struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 806 | { |
Herbert Xu | fb286bb | 2005-11-10 13:01:24 -0800 | [diff] [blame] | 807 | return __skb_checksum_complete(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 808 | } |
| 809 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 810 | static inline int tcp_checksum_complete(struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 811 | { |
| 812 | return skb->ip_summed != CHECKSUM_UNNECESSARY && |
| 813 | __tcp_checksum_complete(skb); |
| 814 | } |
| 815 | |
| 816 | /* Prequeue for VJ style copy to user, combined with checksumming. */ |
| 817 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 818 | static inline void tcp_prequeue_init(struct tcp_sock *tp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 819 | { |
| 820 | tp->ucopy.task = NULL; |
| 821 | tp->ucopy.len = 0; |
| 822 | tp->ucopy.memory = 0; |
| 823 | skb_queue_head_init(&tp->ucopy.prequeue); |
Chris Leech | 97fc2f0 | 2006-05-23 17:55:33 -0700 | [diff] [blame] | 824 | #ifdef CONFIG_NET_DMA |
| 825 | tp->ucopy.dma_chan = NULL; |
| 826 | tp->ucopy.wakeup = 0; |
| 827 | tp->ucopy.pinned_list = NULL; |
| 828 | tp->ucopy.dma_cookie = 0; |
| 829 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | } |
| 831 | |
| 832 | /* Packet is added to VJ-style prequeue for processing in process |
| 833 | * context, if a reader task is waiting. Apparently, this exciting |
| 834 | * idea (VJ's mail "Re: query about TCP header on tcp-ip" of 07 Sep 93) |
| 835 | * failed somewhere. Latency? Burstiness? Well, at least now we will |
| 836 | * see, why it failed. 8)8) --ANK |
| 837 | * |
| 838 | * NOTE: is this not too big to inline? |
| 839 | */ |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 840 | static inline int tcp_prequeue(struct sock *sk, struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 841 | { |
| 842 | struct tcp_sock *tp = tcp_sk(sk); |
| 843 | |
| 844 | if (!sysctl_tcp_low_latency && tp->ucopy.task) { |
| 845 | __skb_queue_tail(&tp->ucopy.prequeue, skb); |
| 846 | tp->ucopy.memory += skb->truesize; |
| 847 | if (tp->ucopy.memory > sk->sk_rcvbuf) { |
| 848 | struct sk_buff *skb1; |
| 849 | |
| 850 | BUG_ON(sock_owned_by_user(sk)); |
| 851 | |
| 852 | while ((skb1 = __skb_dequeue(&tp->ucopy.prequeue)) != NULL) { |
| 853 | sk->sk_backlog_rcv(sk, skb1); |
| 854 | NET_INC_STATS_BH(LINUX_MIB_TCPPREQUEUEDROPPED); |
| 855 | } |
| 856 | |
| 857 | tp->ucopy.memory = 0; |
| 858 | } else if (skb_queue_len(&tp->ucopy.prequeue) == 1) { |
| 859 | wake_up_interruptible(sk->sk_sleep); |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 860 | if (!inet_csk_ack_scheduled(sk)) |
| 861 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
Arnaldo Carvalho de Melo | 3f421ba | 2005-08-09 20:11:08 -0700 | [diff] [blame] | 862 | (3 * TCP_RTO_MIN) / 4, |
| 863 | TCP_RTO_MAX); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 864 | } |
| 865 | return 1; |
| 866 | } |
| 867 | return 0; |
| 868 | } |
| 869 | |
| 870 | |
| 871 | #undef STATE_TRACE |
| 872 | |
| 873 | #ifdef STATE_TRACE |
| 874 | static const char *statename[]={ |
| 875 | "Unused","Established","Syn Sent","Syn Recv", |
| 876 | "Fin Wait 1","Fin Wait 2","Time Wait", "Close", |
| 877 | "Close Wait","Last ACK","Listen","Closing" |
| 878 | }; |
| 879 | #endif |
| 880 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 881 | static inline void tcp_set_state(struct sock *sk, int state) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 882 | { |
| 883 | int oldstate = sk->sk_state; |
| 884 | |
| 885 | switch (state) { |
| 886 | case TCP_ESTABLISHED: |
| 887 | if (oldstate != TCP_ESTABLISHED) |
| 888 | TCP_INC_STATS(TCP_MIB_CURRESTAB); |
| 889 | break; |
| 890 | |
| 891 | case TCP_CLOSE: |
| 892 | if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED) |
| 893 | TCP_INC_STATS(TCP_MIB_ESTABRESETS); |
| 894 | |
| 895 | sk->sk_prot->unhash(sk); |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 896 | if (inet_csk(sk)->icsk_bind_hash && |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 897 | !(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) |
Arnaldo Carvalho de Melo | 2d8c4ce | 2005-08-09 20:07:13 -0700 | [diff] [blame] | 898 | inet_put_port(&tcp_hashinfo, sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 899 | /* fall through */ |
| 900 | default: |
| 901 | if (oldstate==TCP_ESTABLISHED) |
| 902 | TCP_DEC_STATS(TCP_MIB_CURRESTAB); |
| 903 | } |
| 904 | |
| 905 | /* Change state AFTER socket is unhashed to avoid closed |
| 906 | * socket sitting in hash tables. |
| 907 | */ |
| 908 | sk->sk_state = state; |
| 909 | |
| 910 | #ifdef STATE_TRACE |
| 911 | SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n",sk, statename[oldstate],statename[state]); |
| 912 | #endif |
| 913 | } |
| 914 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 915 | static inline void tcp_done(struct sock *sk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 916 | { |
Wei Yongjun | 3687b1d | 2006-07-30 20:35:54 -0700 | [diff] [blame] | 917 | if(sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV) |
| 918 | TCP_INC_STATS_BH(TCP_MIB_ATTEMPTFAILS); |
| 919 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 920 | tcp_set_state(sk, TCP_CLOSE); |
| 921 | tcp_clear_xmit_timers(sk); |
| 922 | |
| 923 | sk->sk_shutdown = SHUTDOWN_MASK; |
| 924 | |
| 925 | if (!sock_flag(sk, SOCK_DEAD)) |
| 926 | sk->sk_state_change(sk); |
| 927 | else |
Arnaldo Carvalho de Melo | 0a5578c | 2005-08-09 20:11:41 -0700 | [diff] [blame] | 928 | inet_csk_destroy_sock(sk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 929 | } |
| 930 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 931 | static inline void tcp_sack_reset(struct tcp_options_received *rx_opt) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 932 | { |
| 933 | rx_opt->dsack = 0; |
| 934 | rx_opt->eff_sacks = 0; |
| 935 | rx_opt->num_sacks = 0; |
| 936 | } |
| 937 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 938 | /* Determine a window scaling and initial window to offer. */ |
| 939 | extern void tcp_select_initial_window(int __space, __u32 mss, |
| 940 | __u32 *rcv_wnd, __u32 *window_clamp, |
| 941 | int wscale_ok, __u8 *rcv_wscale); |
| 942 | |
| 943 | static inline int tcp_win_from_space(int space) |
| 944 | { |
| 945 | return sysctl_tcp_adv_win_scale<=0 ? |
| 946 | (space>>(-sysctl_tcp_adv_win_scale)) : |
| 947 | space - (space>>sysctl_tcp_adv_win_scale); |
| 948 | } |
| 949 | |
| 950 | /* Note: caller must be prepared to deal with negative returns */ |
| 951 | static inline int tcp_space(const struct sock *sk) |
| 952 | { |
| 953 | return tcp_win_from_space(sk->sk_rcvbuf - |
| 954 | atomic_read(&sk->sk_rmem_alloc)); |
| 955 | } |
| 956 | |
| 957 | static inline int tcp_full_space(const struct sock *sk) |
| 958 | { |
| 959 | return tcp_win_from_space(sk->sk_rcvbuf); |
| 960 | } |
| 961 | |
Stephen Hemminger | 40efc6f | 2006-01-03 16:03:49 -0800 | [diff] [blame] | 962 | static inline void tcp_openreq_init(struct request_sock *req, |
| 963 | struct tcp_options_received *rx_opt, |
| 964 | struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 965 | { |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 966 | struct inet_request_sock *ireq = inet_rsk(req); |
| 967 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 968 | req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */ |
Arnaldo Carvalho de Melo | 2e6599c | 2005-06-18 22:46:52 -0700 | [diff] [blame] | 969 | tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 970 | req->mss = rx_opt->mss_clamp; |
| 971 | 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] | 972 | ireq->tstamp_ok = rx_opt->tstamp_ok; |
| 973 | ireq->sack_ok = rx_opt->sack_ok; |
| 974 | ireq->snd_wscale = rx_opt->snd_wscale; |
| 975 | ireq->wscale_ok = rx_opt->wscale_ok; |
| 976 | ireq->acked = 0; |
| 977 | ireq->ecn_ok = 0; |
| 978 | ireq->rmt_port = skb->h.th->source; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 979 | } |
| 980 | |
| 981 | extern void tcp_enter_memory_pressure(void); |
| 982 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 983 | static inline int keepalive_intvl_when(const struct tcp_sock *tp) |
| 984 | { |
| 985 | return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl; |
| 986 | } |
| 987 | |
| 988 | static inline int keepalive_time_when(const struct tcp_sock *tp) |
| 989 | { |
| 990 | return tp->keepalive_time ? : sysctl_tcp_keepalive_time; |
| 991 | } |
| 992 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 993 | static inline int tcp_fin_time(const struct sock *sk) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 994 | { |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 995 | int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout; |
| 996 | const int rto = inet_csk(sk)->icsk_rto; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 997 | |
Arnaldo Carvalho de Melo | 463c84b | 2005-08-09 20:10:42 -0700 | [diff] [blame] | 998 | if (fin_timeout < (rto << 2) - (rto >> 1)) |
| 999 | fin_timeout = (rto << 2) - (rto >> 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1000 | |
| 1001 | return fin_timeout; |
| 1002 | } |
| 1003 | |
| 1004 | static inline int tcp_paws_check(const struct tcp_options_received *rx_opt, int rst) |
| 1005 | { |
| 1006 | if ((s32)(rx_opt->rcv_tsval - rx_opt->ts_recent) >= 0) |
| 1007 | return 0; |
| 1008 | if (xtime.tv_sec >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS) |
| 1009 | return 0; |
| 1010 | |
| 1011 | /* RST segments are not recommended to carry timestamp, |
| 1012 | and, if they do, it is recommended to ignore PAWS because |
| 1013 | "their cleanup function should take precedence over timestamps." |
| 1014 | Certainly, it is mistake. It is necessary to understand the reasons |
| 1015 | of this constraint to relax it: if peer reboots, clock may go |
| 1016 | out-of-sync and half-open connections will not be reset. |
| 1017 | Actually, the problem would be not existing if all |
| 1018 | the implementations followed draft about maintaining clock |
| 1019 | via reboots. Linux-2.2 DOES NOT! |
| 1020 | |
| 1021 | However, we can relax time bounds for RST segments to MSL. |
| 1022 | */ |
| 1023 | if (rst && xtime.tv_sec >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL) |
| 1024 | return 0; |
| 1025 | return 1; |
| 1026 | } |
| 1027 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1028 | #define TCP_CHECK_TIMER(sk) do { } while (0) |
| 1029 | |
| 1030 | static inline int tcp_use_frto(const struct sock *sk) |
| 1031 | { |
| 1032 | const struct tcp_sock *tp = tcp_sk(sk); |
| 1033 | |
| 1034 | /* F-RTO must be activated in sysctl and there must be some |
| 1035 | * unsent new data, and the advertised window should allow |
| 1036 | * sending it. |
| 1037 | */ |
| 1038 | return (sysctl_tcp_frto && sk->sk_send_head && |
| 1039 | !after(TCP_SKB_CB(sk->sk_send_head)->end_seq, |
| 1040 | tp->snd_una + tp->snd_wnd)); |
| 1041 | } |
| 1042 | |
| 1043 | static inline void tcp_mib_init(void) |
| 1044 | { |
| 1045 | /* See RFC 2012 */ |
| 1046 | TCP_ADD_STATS_USER(TCP_MIB_RTOALGORITHM, 1); |
| 1047 | TCP_ADD_STATS_USER(TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ); |
| 1048 | TCP_ADD_STATS_USER(TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ); |
| 1049 | TCP_ADD_STATS_USER(TCP_MIB_MAXCONN, -1); |
| 1050 | } |
| 1051 | |
Stephen Hemminger | 6a438bb | 2005-11-10 17:14:59 -0800 | [diff] [blame] | 1052 | /*from STCP */ |
| 1053 | static inline void clear_all_retrans_hints(struct tcp_sock *tp){ |
| 1054 | tp->lost_skb_hint = NULL; |
| 1055 | tp->scoreboard_skb_hint = NULL; |
| 1056 | tp->retransmit_skb_hint = NULL; |
| 1057 | tp->forward_skb_hint = NULL; |
| 1058 | tp->fastpath_skb_hint = NULL; |
| 1059 | } |
| 1060 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1061 | /* /proc */ |
| 1062 | enum tcp_seq_states { |
| 1063 | TCP_SEQ_STATE_LISTENING, |
| 1064 | TCP_SEQ_STATE_OPENREQ, |
| 1065 | TCP_SEQ_STATE_ESTABLISHED, |
| 1066 | TCP_SEQ_STATE_TIME_WAIT, |
| 1067 | }; |
| 1068 | |
| 1069 | struct tcp_seq_afinfo { |
| 1070 | struct module *owner; |
| 1071 | char *name; |
| 1072 | sa_family_t family; |
| 1073 | int (*seq_show) (struct seq_file *m, void *v); |
| 1074 | struct file_operations *seq_fops; |
| 1075 | }; |
| 1076 | |
| 1077 | struct tcp_iter_state { |
| 1078 | sa_family_t family; |
| 1079 | enum tcp_seq_states state; |
| 1080 | struct sock *syn_wait_sk; |
| 1081 | int bucket, sbucket, num, uid; |
| 1082 | struct seq_operations seq_ops; |
| 1083 | }; |
| 1084 | |
| 1085 | extern int tcp_proc_register(struct tcp_seq_afinfo *afinfo); |
| 1086 | extern void tcp_proc_unregister(struct tcp_seq_afinfo *afinfo); |
| 1087 | |
Arnaldo Carvalho de Melo | 2038073 | 2005-08-16 02:18:02 -0300 | [diff] [blame] | 1088 | extern struct request_sock_ops tcp_request_sock_ops; |
| 1089 | |
| 1090 | extern int tcp_v4_destroy_sock(struct sock *sk); |
| 1091 | |
Herbert Xu | a430a43 | 2006-07-08 13:34:56 -0700 | [diff] [blame] | 1092 | extern int tcp_v4_gso_send_check(struct sk_buff *skb); |
Herbert Xu | 576a30e | 2006-06-27 13:22:38 -0700 | [diff] [blame] | 1093 | extern struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features); |
Herbert Xu | f4c50d9 | 2006-06-22 03:02:40 -0700 | [diff] [blame] | 1094 | |
Arnaldo Carvalho de Melo | 2038073 | 2005-08-16 02:18:02 -0300 | [diff] [blame] | 1095 | #ifdef CONFIG_PROC_FS |
| 1096 | extern int tcp4_proc_init(void); |
| 1097 | extern void tcp4_proc_exit(void); |
| 1098 | #endif |
| 1099 | |
| 1100 | extern void tcp_v4_init(struct net_proto_family *ops); |
| 1101 | extern void tcp_init(void); |
| 1102 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1103 | #endif /* _TCP_H */ |