tcp.h 11 KB

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  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 protocol.
  7. *
  8. * Version: @(#)tcp.h 1.0.2 04/28/93
  9. *
  10. * Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  11. *
  12. * This program is free software; you can redistribute it and/or
  13. * modify it under the terms of the GNU General Public License
  14. * as published by the Free Software Foundation; either version
  15. * 2 of the License, or (at your option) any later version.
  16. */
  17. #ifndef _LINUX_TCP_H
  18. #define _LINUX_TCP_H
  19. #include <linux/types.h>
  20. #include <asm/byteorder.h>
  21. #include <linux/socket.h>
  22. struct tcphdr {
  23. __be16 source;
  24. __be16 dest;
  25. __be32 seq;
  26. __be32 ack_seq;
  27. #if defined(__LITTLE_ENDIAN_BITFIELD)
  28. __u16 res1:4,
  29. doff:4,
  30. fin:1,
  31. syn:1,
  32. rst:1,
  33. psh:1,
  34. ack:1,
  35. urg:1,
  36. ece:1,
  37. cwr:1;
  38. #elif defined(__BIG_ENDIAN_BITFIELD)
  39. __u16 doff:4,
  40. res1:4,
  41. cwr:1,
  42. ece:1,
  43. urg:1,
  44. ack:1,
  45. psh:1,
  46. rst:1,
  47. syn:1,
  48. fin:1;
  49. #else
  50. #error "Adjust your <asm/byteorder.h> defines"
  51. #endif
  52. __be16 window;
  53. __sum16 check;
  54. __be16 urg_ptr;
  55. };
  56. /*
  57. * The union cast uses a gcc extension to avoid aliasing problems
  58. * (union is compatible to any of its members)
  59. * This means this part of the code is -fstrict-aliasing safe now.
  60. */
  61. union tcp_word_hdr {
  62. struct tcphdr hdr;
  63. __be32 words[5];
  64. };
  65. #define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3])
  66. enum {
  67. TCP_FLAG_CWR = __constant_htonl(0x00800000),
  68. TCP_FLAG_ECE = __constant_htonl(0x00400000),
  69. TCP_FLAG_URG = __constant_htonl(0x00200000),
  70. TCP_FLAG_ACK = __constant_htonl(0x00100000),
  71. TCP_FLAG_PSH = __constant_htonl(0x00080000),
  72. TCP_FLAG_RST = __constant_htonl(0x00040000),
  73. TCP_FLAG_SYN = __constant_htonl(0x00020000),
  74. TCP_FLAG_FIN = __constant_htonl(0x00010000),
  75. TCP_RESERVED_BITS = __constant_htonl(0x0F000000),
  76. TCP_DATA_OFFSET = __constant_htonl(0xF0000000)
  77. };
  78. /* TCP socket options */
  79. #define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */
  80. #define TCP_MAXSEG 2 /* Limit MSS */
  81. #define TCP_CORK 3 /* Never send partially complete segments */
  82. #define TCP_KEEPIDLE 4 /* Start keeplives after this period */
  83. #define TCP_KEEPINTVL 5 /* Interval between keepalives */
  84. #define TCP_KEEPCNT 6 /* Number of keepalives before death */
  85. #define TCP_SYNCNT 7 /* Number of SYN retransmits */
  86. #define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */
  87. #define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */
  88. #define TCP_WINDOW_CLAMP 10 /* Bound advertised window */
  89. #define TCP_INFO 11 /* Information about this connection. */
  90. #define TCP_QUICKACK 12 /* Block/reenable quick acks */
  91. #define TCP_CONGESTION 13 /* Congestion control algorithm */
  92. #define TCP_MD5SIG 14 /* TCP MD5 Signature (RFC2385) */
  93. #define TCPI_OPT_TIMESTAMPS 1
  94. #define TCPI_OPT_SACK 2
  95. #define TCPI_OPT_WSCALE 4
  96. #define TCPI_OPT_ECN 8
  97. enum tcp_ca_state
  98. {
  99. TCP_CA_Open = 0,
  100. #define TCPF_CA_Open (1<<TCP_CA_Open)
  101. TCP_CA_Disorder = 1,
  102. #define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
  103. TCP_CA_CWR = 2,
  104. #define TCPF_CA_CWR (1<<TCP_CA_CWR)
  105. TCP_CA_Recovery = 3,
  106. #define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
  107. TCP_CA_Loss = 4
  108. #define TCPF_CA_Loss (1<<TCP_CA_Loss)
  109. };
  110. struct tcp_info
  111. {
  112. __u8 tcpi_state;
  113. __u8 tcpi_ca_state;
  114. __u8 tcpi_retransmits;
  115. __u8 tcpi_probes;
  116. __u8 tcpi_backoff;
  117. __u8 tcpi_options;
  118. __u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
  119. __u32 tcpi_rto;
  120. __u32 tcpi_ato;
  121. __u32 tcpi_snd_mss;
  122. __u32 tcpi_rcv_mss;
  123. __u32 tcpi_unacked;
  124. __u32 tcpi_sacked;
  125. __u32 tcpi_lost;
  126. __u32 tcpi_retrans;
  127. __u32 tcpi_fackets;
  128. /* Times. */
  129. __u32 tcpi_last_data_sent;
  130. __u32 tcpi_last_ack_sent; /* Not remembered, sorry. */
  131. __u32 tcpi_last_data_recv;
  132. __u32 tcpi_last_ack_recv;
  133. /* Metrics. */
  134. __u32 tcpi_pmtu;
  135. __u32 tcpi_rcv_ssthresh;
  136. __u32 tcpi_rtt;
  137. __u32 tcpi_rttvar;
  138. __u32 tcpi_snd_ssthresh;
  139. __u32 tcpi_snd_cwnd;
  140. __u32 tcpi_advmss;
  141. __u32 tcpi_reordering;
  142. __u32 tcpi_rcv_rtt;
  143. __u32 tcpi_rcv_space;
  144. __u32 tcpi_total_retrans;
  145. };
  146. /* for TCP_MD5SIG socket option */
  147. #define TCP_MD5SIG_MAXKEYLEN 80
  148. struct tcp_md5sig {
  149. struct __kernel_sockaddr_storage tcpm_addr; /* address associated */
  150. __u16 __tcpm_pad1; /* zero */
  151. __u16 tcpm_keylen; /* key length */
  152. __u32 __tcpm_pad2; /* zero */
  153. __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */
  154. };
  155. #ifdef __KERNEL__
  156. #include <linux/skbuff.h>
  157. #include <linux/dmaengine.h>
  158. #include <net/sock.h>
  159. #include <net/inet_connection_sock.h>
  160. #include <net/inet_timewait_sock.h>
  161. /* This defines a selective acknowledgement block. */
  162. struct tcp_sack_block_wire {
  163. __be32 start_seq;
  164. __be32 end_seq;
  165. };
  166. struct tcp_sack_block {
  167. u32 start_seq;
  168. u32 end_seq;
  169. };
  170. struct tcp_options_received {
  171. /* PAWS/RTTM data */
  172. long ts_recent_stamp;/* Time we stored ts_recent (for aging) */
  173. u32 ts_recent; /* Time stamp to echo next */
  174. u32 rcv_tsval; /* Time stamp value */
  175. u32 rcv_tsecr; /* Time stamp echo reply */
  176. u16 saw_tstamp : 1, /* Saw TIMESTAMP on last packet */
  177. tstamp_ok : 1, /* TIMESTAMP seen on SYN packet */
  178. dsack : 1, /* D-SACK is scheduled */
  179. wscale_ok : 1, /* Wscale seen on SYN packet */
  180. sack_ok : 4, /* SACK seen on SYN packet */
  181. snd_wscale : 4, /* Window scaling received from sender */
  182. rcv_wscale : 4; /* Window scaling to send to receiver */
  183. /* SACKs data */
  184. u8 eff_sacks; /* Size of SACK array to send with next packet */
  185. u8 num_sacks; /* Number of SACK blocks */
  186. u16 user_mss; /* mss requested by user in ioctl */
  187. u16 mss_clamp; /* Maximal mss, negotiated at connection setup */
  188. };
  189. struct tcp_request_sock {
  190. struct inet_request_sock req;
  191. #ifdef CONFIG_TCP_MD5SIG
  192. /* Only used by TCP MD5 Signature so far. */
  193. struct tcp_request_sock_ops *af_specific;
  194. #endif
  195. u32 rcv_isn;
  196. u32 snt_isn;
  197. };
  198. static inline struct tcp_request_sock *tcp_rsk(const struct request_sock *req)
  199. {
  200. return (struct tcp_request_sock *)req;
  201. }
  202. struct tcp_sock {
  203. /* inet_connection_sock has to be the first member of tcp_sock */
  204. struct inet_connection_sock inet_conn;
  205. u16 tcp_header_len; /* Bytes of tcp header to send */
  206. u16 xmit_size_goal; /* Goal for segmenting output packets */
  207. /*
  208. * Header prediction flags
  209. * 0x5?10 << 16 + snd_wnd in net byte order
  210. */
  211. __be32 pred_flags;
  212. /*
  213. * RFC793 variables by their proper names. This means you can
  214. * read the code and the spec side by side (and laugh ...)
  215. * See RFC793 and RFC1122. The RFC writes these in capitals.
  216. */
  217. u32 rcv_nxt; /* What we want to receive next */
  218. u32 snd_nxt; /* Next sequence we send */
  219. u32 snd_una; /* First byte we want an ack for */
  220. u32 snd_sml; /* Last byte of the most recently transmitted small packet */
  221. u32 rcv_tstamp; /* timestamp of last received ACK (for keepalives) */
  222. u32 lsndtime; /* timestamp of last sent data packet (for restart window) */
  223. /* Data for direct copy to user */
  224. struct {
  225. struct sk_buff_head prequeue;
  226. struct task_struct *task;
  227. struct iovec *iov;
  228. int memory;
  229. int len;
  230. #ifdef CONFIG_NET_DMA
  231. /* members for async copy */
  232. struct dma_chan *dma_chan;
  233. int wakeup;
  234. struct dma_pinned_list *pinned_list;
  235. dma_cookie_t dma_cookie;
  236. #endif
  237. } ucopy;
  238. u32 snd_wl1; /* Sequence for window update */
  239. u32 snd_wnd; /* The window we expect to receive */
  240. u32 max_window; /* Maximal window ever seen from peer */
  241. u32 mss_cache; /* Cached effective mss, not including SACKS */
  242. u32 window_clamp; /* Maximal window to advertise */
  243. u32 rcv_ssthresh; /* Current window clamp */
  244. u32 frto_highmark; /* snd_nxt when RTO occurred */
  245. u8 reordering; /* Packet reordering metric. */
  246. u8 frto_counter; /* Number of new acks after RTO */
  247. u8 nonagle; /* Disable Nagle algorithm? */
  248. u8 keepalive_probes; /* num of allowed keep alive probes */
  249. /* RTT measurement */
  250. u32 srtt; /* smoothed round trip time << 3 */
  251. u32 mdev; /* medium deviation */
  252. u32 mdev_max; /* maximal mdev for the last rtt period */
  253. u32 rttvar; /* smoothed mdev_max */
  254. u32 rtt_seq; /* sequence number to update rttvar */
  255. u32 packets_out; /* Packets which are "in flight" */
  256. u32 left_out; /* Packets which leaved network */
  257. u32 retrans_out; /* Retransmitted packets out */
  258. /*
  259. * Options received (usually on last packet, some only on SYN packets).
  260. */
  261. struct tcp_options_received rx_opt;
  262. /*
  263. * Slow start and congestion control (see also Nagle, and Karn & Partridge)
  264. */
  265. u32 snd_ssthresh; /* Slow start size threshold */
  266. u32 snd_cwnd; /* Sending congestion window */
  267. u16 snd_cwnd_cnt; /* Linear increase counter */
  268. u16 snd_cwnd_clamp; /* Do not allow snd_cwnd to grow above this */
  269. u32 snd_cwnd_used;
  270. u32 snd_cwnd_stamp;
  271. struct sk_buff_head out_of_order_queue; /* Out of order segments go here */
  272. u32 rcv_wnd; /* Current receiver window */
  273. u32 rcv_wup; /* rcv_nxt on last window update sent */
  274. u32 write_seq; /* Tail(+1) of data held in tcp send buffer */
  275. u32 pushed_seq; /* Last pushed seq, required to talk to windows */
  276. u32 copied_seq; /* Head of yet unread data */
  277. /* SACKs data */
  278. struct tcp_sack_block duplicate_sack[1]; /* D-SACK block */
  279. struct tcp_sack_block selective_acks[4]; /* The SACKS themselves*/
  280. struct tcp_sack_block_wire recv_sack_cache[4];
  281. /* from STCP, retrans queue hinting */
  282. struct sk_buff* lost_skb_hint;
  283. struct sk_buff *scoreboard_skb_hint;
  284. struct sk_buff *retransmit_skb_hint;
  285. struct sk_buff *forward_skb_hint;
  286. struct sk_buff *fastpath_skb_hint;
  287. int fastpath_cnt_hint;
  288. int lost_cnt_hint;
  289. int retransmit_cnt_hint;
  290. int forward_cnt_hint;
  291. u16 advmss; /* Advertised MSS */
  292. u16 prior_ssthresh; /* ssthresh saved at recovery start */
  293. u32 lost_out; /* Lost packets */
  294. u32 sacked_out; /* SACK'd packets */
  295. u32 fackets_out; /* FACK'd packets */
  296. u32 high_seq; /* snd_nxt at onset of congestion */
  297. u32 retrans_stamp; /* Timestamp of the last retransmit,
  298. * also used in SYN-SENT to remember stamp of
  299. * the first SYN. */
  300. u32 undo_marker; /* tracking retrans started here. */
  301. int undo_retrans; /* number of undoable retransmissions. */
  302. u32 urg_seq; /* Seq of received urgent pointer */
  303. u16 urg_data; /* Saved octet of OOB data and control flags */
  304. u8 urg_mode; /* In urgent mode */
  305. u8 ecn_flags; /* ECN status bits. */
  306. u32 snd_up; /* Urgent pointer */
  307. u32 total_retrans; /* Total retransmits for entire connection */
  308. u32 bytes_acked; /* Appropriate Byte Counting - RFC3465 */
  309. unsigned int keepalive_time; /* time before keep alive takes place */
  310. unsigned int keepalive_intvl; /* time interval between keep alive probes */
  311. int linger2;
  312. unsigned long last_synq_overflow;
  313. u32 tso_deferred;
  314. /* Receiver side RTT estimation */
  315. struct {
  316. u32 rtt;
  317. u32 seq;
  318. u32 time;
  319. } rcv_rtt_est;
  320. /* Receiver queue space */
  321. struct {
  322. int space;
  323. u32 seq;
  324. u32 time;
  325. } rcvq_space;
  326. /* TCP-specific MTU probe information. */
  327. struct {
  328. u32 probe_seq_start;
  329. u32 probe_seq_end;
  330. } mtu_probe;
  331. #ifdef CONFIG_TCP_MD5SIG
  332. /* TCP AF-Specific parts; only used by MD5 Signature support so far */
  333. struct tcp_sock_af_ops *af_specific;
  334. /* TCP MD5 Signagure Option information */
  335. struct tcp_md5sig_info *md5sig_info;
  336. #endif
  337. };
  338. static inline struct tcp_sock *tcp_sk(const struct sock *sk)
  339. {
  340. return (struct tcp_sock *)sk;
  341. }
  342. struct tcp_timewait_sock {
  343. struct inet_timewait_sock tw_sk;
  344. u32 tw_rcv_nxt;
  345. u32 tw_snd_nxt;
  346. u32 tw_rcv_wnd;
  347. u32 tw_ts_recent;
  348. long tw_ts_recent_stamp;
  349. #ifdef CONFIG_TCP_MD5SIG
  350. u16 tw_md5_keylen;
  351. u8 tw_md5_key[TCP_MD5SIG_MAXKEYLEN];
  352. #endif
  353. };
  354. static inline struct tcp_timewait_sock *tcp_twsk(const struct sock *sk)
  355. {
  356. return (struct tcp_timewait_sock *)sk;
  357. }
  358. #endif
  359. #endif /* _LINUX_TCP_H */