1/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
2/*
3 * INET An implementation of the TCP/IP protocol suite for the LINUX
4 * operating system. INET is implemented using the BSD Socket
5 * interface as the means of communication with the user level.
6 *
7 * Definitions for the TCP protocol.
8 *
9 * Version: @(#)tcp.h 1.0.2 04/28/93
10 *
11 * Author: 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 _LINUX_TCP_H
19#define _LINUX_TCP_H
20
21#include <linux/types.h>
22#include <asm/byteorder.h>
23#include <linux/socket.h>
24
25struct tcphdr {
26 __be16 source;
27 __be16 dest;
28 __be32 seq;
29 __be32 ack_seq;
30#if defined(__LITTLE_ENDIAN_BITFIELD)
31 __u16 ae:1,
32 res1:3,
33 doff:4,
34 fin:1,
35 syn:1,
36 rst:1,
37 psh:1,
38 ack:1,
39 urg:1,
40 ece:1,
41 cwr:1;
42#elif defined(__BIG_ENDIAN_BITFIELD)
43 __u16 doff:4,
44 res1:3,
45 ae:1,
46 cwr:1,
47 ece:1,
48 urg:1,
49 ack:1,
50 psh:1,
51 rst:1,
52 syn:1,
53 fin:1;
54#else
55#error "Adjust your <asm/byteorder.h> defines"
56#endif
57 __be16 window;
58 __sum16 check;
59 __be16 urg_ptr;
60};
61
62/*
63 * The union cast uses a gcc extension to avoid aliasing problems
64 * (union is compatible to any of its members)
65 * This means this part of the code is -fstrict-aliasing safe now.
66 */
67union tcp_word_hdr {
68 struct tcphdr hdr;
69 __be32 words[5];
70};
71
72#define tcp_flag_word(tp) (((union tcp_word_hdr *)(tp))->words[3])
73
74enum {
75 TCP_FLAG_AE = __constant_cpu_to_be32(0x01000000),
76 TCP_FLAG_CWR = __constant_cpu_to_be32(0x00800000),
77 TCP_FLAG_ECE = __constant_cpu_to_be32(0x00400000),
78 TCP_FLAG_URG = __constant_cpu_to_be32(0x00200000),
79 TCP_FLAG_ACK = __constant_cpu_to_be32(0x00100000),
80 TCP_FLAG_PSH = __constant_cpu_to_be32(0x00080000),
81 TCP_FLAG_RST = __constant_cpu_to_be32(0x00040000),
82 TCP_FLAG_SYN = __constant_cpu_to_be32(0x00020000),
83 TCP_FLAG_FIN = __constant_cpu_to_be32(0x00010000),
84 TCP_RESERVED_BITS = __constant_cpu_to_be32(0x0E000000),
85 TCP_DATA_OFFSET = __constant_cpu_to_be32(0xF0000000)
86};
87
88/*
89 * TCP general constants
90 */
91#define TCP_MSS_DEFAULT 536U /* IPv4 (RFC1122, RFC2581) */
92#define TCP_MSS_DESIRED 1220U /* IPv6 (tunneled), EDNS0 (RFC3226) */
93
94/* TCP socket options */
95#define TCP_NODELAY 1 /* Turn off Nagle's algorithm. */
96#define TCP_MAXSEG 2 /* Limit MSS */
97#define TCP_CORK 3 /* Never send partially complete segments */
98#define TCP_KEEPIDLE 4 /* Start keeplives after this period */
99#define TCP_KEEPINTVL 5 /* Interval between keepalives */
100#define TCP_KEEPCNT 6 /* Number of keepalives before death */
101#define TCP_SYNCNT 7 /* Number of SYN retransmits */
102#define TCP_LINGER2 8 /* Life time of orphaned FIN-WAIT-2 state */
103#define TCP_DEFER_ACCEPT 9 /* Wake up listener only when data arrive */
104#define TCP_WINDOW_CLAMP 10 /* Bound advertised window */
105#define TCP_INFO 11 /* Information about this connection. */
106#define TCP_QUICKACK 12 /* Block/reenable quick acks */
107#define TCP_CONGESTION 13 /* Congestion control algorithm */
108#define TCP_MD5SIG 14 /* TCP MD5 Signature (RFC2385) */
109#define TCP_THIN_LINEAR_TIMEOUTS 16 /* Use linear timeouts for thin streams*/
110#define TCP_THIN_DUPACK 17 /* Fast retrans. after 1 dupack */
111#define TCP_USER_TIMEOUT 18 /* How long for loss retry before timeout */
112#define TCP_REPAIR 19 /* TCP sock is under repair right now */
113#define TCP_REPAIR_QUEUE 20
114#define TCP_QUEUE_SEQ 21
115#define TCP_REPAIR_OPTIONS 22
116#define TCP_FASTOPEN 23 /* Enable FastOpen on listeners */
117#define TCP_TIMESTAMP 24
118#define TCP_NOTSENT_LOWAT 25 /* limit number of unsent bytes in write queue */
119#define TCP_CC_INFO 26 /* Get Congestion Control (optional) info */
120#define TCP_SAVE_SYN 27 /* Record SYN headers for new connections */
121#define TCP_SAVED_SYN 28 /* Get SYN headers recorded for connection */
122#define TCP_REPAIR_WINDOW 29 /* Get/set window parameters */
123#define TCP_FASTOPEN_CONNECT 30 /* Attempt FastOpen with connect */
124#define TCP_ULP 31 /* Attach a ULP to a TCP connection */
125#define TCP_MD5SIG_EXT 32 /* TCP MD5 Signature with extensions */
126#define TCP_FASTOPEN_KEY 33 /* Set the key for Fast Open (cookie) */
127#define TCP_FASTOPEN_NO_COOKIE 34 /* Enable TFO without a TFO cookie */
128#define TCP_ZEROCOPY_RECEIVE 35
129#define TCP_INQ 36 /* Notify bytes available to read as a cmsg on read */
130
131#define TCP_CM_INQ TCP_INQ
132
133#define TCP_TX_DELAY 37 /* delay outgoing packets by XX usec */
134
135#define TCP_AO_ADD_KEY 38 /* Add/Set MKT */
136#define TCP_AO_DEL_KEY 39 /* Delete MKT */
137#define TCP_AO_INFO 40 /* Set/list TCP-AO per-socket options */
138#define TCP_AO_GET_KEYS 41 /* List MKT(s) */
139#define TCP_AO_REPAIR 42 /* Get/Set SNEs and ISNs */
140
141#define TCP_IS_MPTCP 43 /* Is MPTCP being used? */
142#define TCP_RTO_MAX_MS 44 /* max rto time in ms */
143#define TCP_RTO_MIN_US 45 /* min rto time in us */
144#define TCP_DELACK_MAX_US 46 /* max delayed ack time in us */
145
146#define TCP_REPAIR_ON 1
147#define TCP_REPAIR_OFF 0
148#define TCP_REPAIR_OFF_NO_WP -1 /* Turn off without window probes */
149
150struct tcp_repair_opt {
151 __u32 opt_code;
152 __u32 opt_val;
153};
154
155struct tcp_repair_window {
156 __u32 snd_wl1;
157 __u32 snd_wnd;
158 __u32 max_window;
159
160 __u32 rcv_wnd;
161 __u32 rcv_wup;
162};
163
164enum {
165 TCP_NO_QUEUE,
166 TCP_RECV_QUEUE,
167 TCP_SEND_QUEUE,
168 TCP_QUEUES_NR,
169};
170
171/* why fastopen failed from client perspective */
172enum tcp_fastopen_client_fail {
173 TFO_STATUS_UNSPEC, /* catch-all */
174 TFO_COOKIE_UNAVAILABLE, /* if not in TFO_CLIENT_NO_COOKIE mode */
175 TFO_DATA_NOT_ACKED, /* SYN-ACK did not ack SYN data */
176 TFO_SYN_RETRANSMITTED, /* SYN-ACK did not ack SYN data after timeout */
177};
178
179/* for TCP_INFO socket option */
180#define TCPI_OPT_TIMESTAMPS 1
181#define TCPI_OPT_SACK 2
182#define TCPI_OPT_WSCALE 4
183#define TCPI_OPT_ECN 8 /* ECN was negociated at TCP session init */
184#define TCPI_OPT_ECN_SEEN 16 /* we received at least one packet with ECT */
185#define TCPI_OPT_SYN_DATA 32 /* SYN-ACK acked data in SYN sent or rcvd */
186#define TCPI_OPT_USEC_TS 64 /* usec timestamps */
187#define TCPI_OPT_TFO_CHILD 128 /* child from a Fast Open option on SYN */
188
189/*
190 * Sender's congestion state indicating normal or abnormal situations
191 * in the last round of packets sent. The state is driven by the ACK
192 * information and timer events.
193 */
194enum tcp_ca_state {
195 /*
196 * Nothing bad has been observed recently.
197 * No apparent reordering, packet loss, or ECN marks.
198 */
199 TCP_CA_Open = 0,
200#define TCPF_CA_Open (1<<TCP_CA_Open)
201 /*
202 * The sender enters disordered state when it has received DUPACKs or
203 * SACKs in the last round of packets sent. This could be due to packet
204 * loss or reordering but needs further information to confirm packets
205 * have been lost.
206 */
207 TCP_CA_Disorder = 1,
208#define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
209 /*
210 * The sender enters Congestion Window Reduction (CWR) state when it
211 * has received ACKs with ECN-ECE marks, or has experienced congestion
212 * or packet discard on the sender host (e.g. qdisc).
213 */
214 TCP_CA_CWR = 2,
215#define TCPF_CA_CWR (1<<TCP_CA_CWR)
216 /*
217 * The sender is in fast recovery and retransmitting lost packets,
218 * typically triggered by ACK events.
219 */
220 TCP_CA_Recovery = 3,
221#define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
222 /*
223 * The sender is in loss recovery triggered by retransmission timeout.
224 */
225 TCP_CA_Loss = 4
226#define TCPF_CA_Loss (1<<TCP_CA_Loss)
227};
228
229/* Values for tcpi_ecn_mode after negotiation */
230#define TCPI_ECN_MODE_DISABLED 0x0
231#define TCPI_ECN_MODE_RFC3168 0x1
232#define TCPI_ECN_MODE_ACCECN 0x2
233#define TCPI_ECN_MODE_PENDING 0x3
234
235/* Values for accecn_opt_seen */
236#define TCP_ACCECN_OPT_NOT_SEEN 0x0
237#define TCP_ACCECN_OPT_EMPTY_SEEN 0x1
238#define TCP_ACCECN_OPT_COUNTER_SEEN 0x2
239#define TCP_ACCECN_OPT_FAIL_SEEN 0x3
240
241/* Values for accecn_fail_mode */
242#define TCP_ACCECN_ACE_FAIL_SEND BIT(0)
243#define TCP_ACCECN_ACE_FAIL_RECV BIT(1)
244#define TCP_ACCECN_OPT_FAIL_SEND BIT(2)
245#define TCP_ACCECN_OPT_FAIL_RECV BIT(3)
246
247struct tcp_info {
248 __u8 tcpi_state;
249 __u8 tcpi_ca_state;
250 __u8 tcpi_retransmits;
251 __u8 tcpi_probes;
252 __u8 tcpi_backoff;
253 __u8 tcpi_options;
254 __u8 tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
255 __u8 tcpi_delivery_rate_app_limited:1, tcpi_fastopen_client_fail:2;
256
257 __u32 tcpi_rto;
258 __u32 tcpi_ato;
259 __u32 tcpi_snd_mss;
260 __u32 tcpi_rcv_mss;
261
262 __u32 tcpi_unacked;
263 __u32 tcpi_sacked;
264 __u32 tcpi_lost;
265 __u32 tcpi_retrans;
266 __u32 tcpi_fackets;
267
268 /* Times. */
269 __u32 tcpi_last_data_sent;
270 __u32 tcpi_last_ack_sent; /* Not remembered, sorry. */
271 __u32 tcpi_last_data_recv;
272 __u32 tcpi_last_ack_recv;
273
274 /* Metrics. */
275 __u32 tcpi_pmtu;
276 __u32 tcpi_rcv_ssthresh;
277 __u32 tcpi_rtt;
278 __u32 tcpi_rttvar;
279 __u32 tcpi_snd_ssthresh;
280 __u32 tcpi_snd_cwnd;
281 __u32 tcpi_advmss;
282 __u32 tcpi_reordering;
283
284 __u32 tcpi_rcv_rtt;
285 __u32 tcpi_rcv_space;
286
287 __u32 tcpi_total_retrans;
288
289 __u64 tcpi_pacing_rate;
290 __u64 tcpi_max_pacing_rate;
291 __u64 tcpi_bytes_acked; /* RFC4898 tcpEStatsAppHCThruOctetsAcked */
292 __u64 tcpi_bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived */
293 __u32 tcpi_segs_out; /* RFC4898 tcpEStatsPerfSegsOut */
294 __u32 tcpi_segs_in; /* RFC4898 tcpEStatsPerfSegsIn */
295
296 __u32 tcpi_notsent_bytes;
297 __u32 tcpi_min_rtt;
298 __u32 tcpi_data_segs_in; /* RFC4898 tcpEStatsDataSegsIn */
299 __u32 tcpi_data_segs_out; /* RFC4898 tcpEStatsDataSegsOut */
300
301 __u64 tcpi_delivery_rate;
302
303 __u64 tcpi_busy_time; /* Time (usec) busy sending data */
304 __u64 tcpi_rwnd_limited; /* Time (usec) limited by receive window */
305 __u64 tcpi_sndbuf_limited; /* Time (usec) limited by send buffer */
306
307 __u32 tcpi_delivered;
308 __u32 tcpi_delivered_ce;
309
310 __u64 tcpi_bytes_sent; /* RFC4898 tcpEStatsPerfHCDataOctetsOut */
311 __u64 tcpi_bytes_retrans; /* RFC4898 tcpEStatsPerfOctetsRetrans */
312 __u32 tcpi_dsack_dups; /* RFC4898 tcpEStatsStackDSACKDups */
313 __u32 tcpi_reord_seen; /* reordering events seen */
314
315 __u32 tcpi_rcv_ooopack; /* Out-of-order packets received */
316
317 __u32 tcpi_snd_wnd; /* peer's advertised receive window after
318 * scaling (bytes)
319 */
320 __u32 tcpi_rcv_wnd; /* local advertised receive window after
321 * scaling (bytes)
322 */
323
324 __u32 tcpi_rehash; /* PLB or timeout triggered rehash attempts */
325
326 __u16 tcpi_total_rto; /* Total number of RTO timeouts, including
327 * SYN/SYN-ACK and recurring timeouts.
328 */
329 __u16 tcpi_total_rto_recoveries; /* Total number of RTO
330 * recoveries, including any
331 * unfinished recovery.
332 */
333 __u32 tcpi_total_rto_time; /* Total time spent in RTO recoveries
334 * in milliseconds, including any
335 * unfinished recovery.
336 */
337 __u32 tcpi_received_ce; /* # of CE marked segments received */
338 __u32 tcpi_delivered_e1_bytes; /* Accurate ECN byte counters */
339 __u32 tcpi_delivered_e0_bytes;
340 __u32 tcpi_delivered_ce_bytes;
341 __u32 tcpi_received_e1_bytes;
342 __u32 tcpi_received_e0_bytes;
343 __u32 tcpi_received_ce_bytes;
344 __u32 tcpi_ecn_mode:2,
345 tcpi_accecn_opt_seen:2,
346 tcpi_accecn_fail_mode:4,
347 tcpi_options2:24;
348};
349
350/* netlink attributes types for SCM_TIMESTAMPING_OPT_STATS */
351enum {
352 TCP_NLA_PAD,
353 TCP_NLA_BUSY, /* Time (usec) busy sending data */
354 TCP_NLA_RWND_LIMITED, /* Time (usec) limited by receive window */
355 TCP_NLA_SNDBUF_LIMITED, /* Time (usec) limited by send buffer */
356 TCP_NLA_DATA_SEGS_OUT, /* Data pkts sent including retransmission */
357 TCP_NLA_TOTAL_RETRANS, /* Data pkts retransmitted */
358 TCP_NLA_PACING_RATE, /* Pacing rate in bytes per second */
359 TCP_NLA_DELIVERY_RATE, /* Delivery rate in bytes per second */
360 TCP_NLA_SND_CWND, /* Sending congestion window */
361 TCP_NLA_REORDERING, /* Reordering metric */
362 TCP_NLA_MIN_RTT, /* minimum RTT */
363 TCP_NLA_RECUR_RETRANS, /* Recurring retransmits for the current pkt */
364 TCP_NLA_DELIVERY_RATE_APP_LMT, /* delivery rate application limited ? */
365 TCP_NLA_SNDQ_SIZE, /* Data (bytes) pending in send queue */
366 TCP_NLA_CA_STATE, /* ca_state of socket */
367 TCP_NLA_SND_SSTHRESH, /* Slow start size threshold */
368 TCP_NLA_DELIVERED, /* Data pkts delivered incl. out-of-order */
369 TCP_NLA_DELIVERED_CE, /* Like above but only ones w/ CE marks */
370 TCP_NLA_BYTES_SENT, /* Data bytes sent including retransmission */
371 TCP_NLA_BYTES_RETRANS, /* Data bytes retransmitted */
372 TCP_NLA_DSACK_DUPS, /* DSACK blocks received */
373 TCP_NLA_REORD_SEEN, /* reordering events seen */
374 TCP_NLA_SRTT, /* smoothed RTT in usecs */
375 TCP_NLA_TIMEOUT_REHASH, /* Timeout-triggered rehash attempts */
376 TCP_NLA_BYTES_NOTSENT, /* Bytes in write queue not yet sent */
377 TCP_NLA_EDT, /* Earliest departure time (CLOCK_MONOTONIC) */
378 TCP_NLA_TTL, /* TTL or hop limit of a packet received */
379 TCP_NLA_REHASH, /* PLB and timeout triggered rehash attempts */
380};
381
382/* for TCP_MD5SIG socket option */
383#define TCP_MD5SIG_MAXKEYLEN 80
384
385/* tcp_md5sig extension flags for TCP_MD5SIG_EXT */
386#define TCP_MD5SIG_FLAG_PREFIX 0x1 /* address prefix length */
387#define TCP_MD5SIG_FLAG_IFINDEX 0x2 /* ifindex set */
388
389struct tcp_md5sig {
390 struct __kernel_sockaddr_storage tcpm_addr; /* address associated */
391 __u8 tcpm_flags; /* extension flags */
392 __u8 tcpm_prefixlen; /* address prefix */
393 __u16 tcpm_keylen; /* key length */
394 int tcpm_ifindex; /* device index for scope */
395 __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */
396};
397
398/* INET_DIAG_MD5SIG */
399struct tcp_diag_md5sig {
400 __u8 tcpm_family;
401 __u8 tcpm_prefixlen;
402 __u16 tcpm_keylen;
403 __be32 tcpm_addr[4];
404 __u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN];
405};
406
407#define TCP_AO_MAXKEYLEN 80
408
409#define TCP_AO_KEYF_IFINDEX (1 << 0) /* L3 ifindex for VRF */
410#define TCP_AO_KEYF_EXCLUDE_OPT (1 << 1) /* "Indicates whether TCP
411 * options other than TCP-AO
412 * are included in the MAC
413 * calculation"
414 */
415
416struct tcp_ao_add { /* setsockopt(TCP_AO_ADD_KEY) */
417 struct __kernel_sockaddr_storage addr; /* peer's address for the key */
418 char alg_name[64]; /* crypto hash algorithm to use */
419 __s32 ifindex; /* L3 dev index for VRF */
420 __u32 set_current :1, /* set key as Current_key at once */
421 set_rnext :1, /* request it from peer with RNext_key */
422 reserved :30; /* must be 0 */
423 __u16 reserved2; /* padding, must be 0 */
424 __u8 prefix; /* peer's address prefix */
425 __u8 sndid; /* SendID for outgoing segments */
426 __u8 rcvid; /* RecvID to match for incoming seg */
427 __u8 maclen; /* length of authentication code (hash) */
428 __u8 keyflags; /* see TCP_AO_KEYF_ */
429 __u8 keylen; /* length of ::key */
430 __u8 key[TCP_AO_MAXKEYLEN];
431} __attribute__((aligned(8)));
432
433struct tcp_ao_del { /* setsockopt(TCP_AO_DEL_KEY) */
434 struct __kernel_sockaddr_storage addr; /* peer's address for the key */
435 __s32 ifindex; /* L3 dev index for VRF */
436 __u32 set_current :1, /* corresponding ::current_key */
437 set_rnext :1, /* corresponding ::rnext */
438 del_async :1, /* only valid for listen sockets */
439 reserved :29; /* must be 0 */
440 __u16 reserved2; /* padding, must be 0 */
441 __u8 prefix; /* peer's address prefix */
442 __u8 sndid; /* SendID for outgoing segments */
443 __u8 rcvid; /* RecvID to match for incoming seg */
444 __u8 current_key; /* KeyID to set as Current_key */
445 __u8 rnext; /* KeyID to set as Rnext_key */
446 __u8 keyflags; /* see TCP_AO_KEYF_ */
447} __attribute__((aligned(8)));
448
449struct tcp_ao_info_opt { /* setsockopt(TCP_AO_INFO), getsockopt(TCP_AO_INFO) */
450 /* Here 'in' is for setsockopt(), 'out' is for getsockopt() */
451 __u32 set_current :1, /* in/out: corresponding ::current_key */
452 set_rnext :1, /* in/out: corresponding ::rnext */
453 ao_required :1, /* in/out: don't accept non-AO connects */
454 set_counters :1, /* in: set/clear ::pkt_* counters */
455 accept_icmps :1, /* in/out: accept incoming ICMPs */
456 reserved :27; /* must be 0 */
457 __u16 reserved2; /* padding, must be 0 */
458 __u8 current_key; /* in/out: KeyID of Current_key */
459 __u8 rnext; /* in/out: keyid of RNext_key */
460 __u64 pkt_good; /* in/out: verified segments */
461 __u64 pkt_bad; /* in/out: failed verification */
462 __u64 pkt_key_not_found; /* in/out: could not find a key to verify */
463 __u64 pkt_ao_required; /* in/out: segments missing TCP-AO sign */
464 __u64 pkt_dropped_icmp; /* in/out: ICMPs that were ignored */
465} __attribute__((aligned(8)));
466
467struct tcp_ao_getsockopt { /* getsockopt(TCP_AO_GET_KEYS) */
468 struct __kernel_sockaddr_storage addr; /* in/out: dump keys for peer
469 * with this address/prefix
470 */
471 char alg_name[64]; /* out: crypto hash algorithm */
472 __u8 key[TCP_AO_MAXKEYLEN];
473 __u32 nkeys; /* in: size of the userspace buffer
474 * @optval, measured in @optlen - the
475 * sizeof(struct tcp_ao_getsockopt)
476 * out: number of keys that matched
477 */
478 __u16 is_current :1, /* in: match and dump Current_key,
479 * out: the dumped key is Current_key
480 */
481
482 is_rnext :1, /* in: match and dump RNext_key,
483 * out: the dumped key is RNext_key
484 */
485 get_all :1, /* in: dump all keys */
486 reserved :13; /* padding, must be 0 */
487 __u8 sndid; /* in/out: dump keys with SendID */
488 __u8 rcvid; /* in/out: dump keys with RecvID */
489 __u8 prefix; /* in/out: dump keys with address/prefix */
490 __u8 maclen; /* out: key's length of authentication
491 * code (hash)
492 */
493 __u8 keyflags; /* in/out: see TCP_AO_KEYF_ */
494 __u8 keylen; /* out: length of ::key */
495 __s32 ifindex; /* in/out: L3 dev index for VRF */
496 __u64 pkt_good; /* out: verified segments */
497 __u64 pkt_bad; /* out: segments that failed verification */
498} __attribute__((aligned(8)));
499
500struct tcp_ao_repair { /* {s,g}etsockopt(TCP_AO_REPAIR) */
501 __be32 snt_isn;
502 __be32 rcv_isn;
503 __u32 snd_sne;
504 __u32 rcv_sne;
505} __attribute__((aligned(8)));
506
507/* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */
508
509#define TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT 0x1
510struct tcp_zerocopy_receive {
511 __u64 address; /* in: address of mapping */
512 __u32 length; /* in/out: number of bytes to map/mapped */
513 __u32 recv_skip_hint; /* out: amount of bytes to skip */
514 __u32 inq; /* out: amount of bytes in read queue */
515 __s32 err; /* out: socket error */
516 __u64 copybuf_address; /* in: copybuf address (small reads) */
517 __s32 copybuf_len; /* in/out: copybuf bytes avail/used or error */
518 __u32 flags; /* in: flags */
519 __u64 msg_control; /* ancillary data */
520 __u64 msg_controllen;
521 __u32 msg_flags;
522 __u32 reserved; /* set to 0 for now */
523};
524#endif /* _LINUX_TCP_H */