Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2021-02-16

The following pull-request contains BPF updates for your *net-next* tree.

There's a small merge conflict between 7eeba1706eba ("tcp: Add receive timestamp
support for receive zerocopy.") from net-next tree and 9cacf81f8161 ("bpf: Remove
extra lock_sock for TCP_ZEROCOPY_RECEIVE") from bpf-next tree. Resolve as follows:

  [...]
                lock_sock(sk);
                err = tcp_zerocopy_receive(sk, &zc, &tss);
                err = BPF_CGROUP_RUN_PROG_GETSOCKOPT_KERN(sk, level, optname,
                                                          &zc, &len, err);
                release_sock(sk);
  [...]

We've added 116 non-merge commits during the last 27 day(s) which contain
a total of 156 files changed, 5662 insertions(+), 1489 deletions(-).

The main changes are:

1) Adds support of pointers to types with known size among global function
   args to overcome the limit on max # of allowed args, from Dmitrii Banshchikov.

2) Add bpf_iter for task_vma which can be used to generate information similar
   to /proc/pid/maps, from Song Liu.

3) Enable bpf_{g,s}etsockopt() from all sock_addr related program hooks. Allow
   rewriting bind user ports from BPF side below the ip_unprivileged_port_start
   range, both from Stanislav Fomichev.

4) Prevent recursion on fentry/fexit & sleepable programs and allow map-in-map
   as well as per-cpu maps for the latter, from Alexei Starovoitov.

5) Add selftest script to run BPF CI locally. Also enable BPF ringbuffer
   for sleepable programs, both from KP Singh.

6) Extend verifier to enable variable offset read/write access to the BPF
   program stack, from Andrei Matei.

7) Improve tc & XDP MTU handling and add a new bpf_check_mtu() helper to
   query device MTU from programs, from Jesper Dangaard Brouer.

8) Allow bpf_get_socket_cookie() helper also be called from [sleepable] BPF
   tracing programs, from Florent Revest.

9) Extend x86 JIT to pad JMPs with NOPs for helping image to converge when
   otherwise too many passes are required, from Gary Lin.

10) Verifier fixes on atomics with BPF_FETCH as well as function-by-function
    verification both related to zero-extension handling, from Ilya Leoshkevich.

11) Better kernel build integration of resolve_btfids tool, from Jiri Olsa.

12) Batch of AF_XDP selftest cleanups and small performance improvement
    for libbpf's xsk map redirect for newer kernels, from Björn Töpel.

13) Follow-up BPF doc and verifier improvements around atomics with
    BPF_FETCH, from Brendan Jackman.

14) Permit zero-sized data sections e.g. if ELF .rodata section contains
    read-only data from local variables, from Yonghong Song.

15) veth driver skb bulk-allocation for ndo_xdp_xmit, from Lorenzo Bianconi.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 458 insertions, 6 deletions

diff --git a/tools/include/linux/types.h b/tools/include/linux/types.h
index 154eb4e3ca7c..e9c5a215837d 100644
--- a/tools/include/linux/types.h
+++ b/tools/include/linux/types.h
@@ -6,7 +6,10 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#ifndef __SANE_USERSPACE_TYPES__
 #define __SANE_USERSPACE_TYPES__	/* For PPC64, to get LL64 types */
+#endif
+
 #include <asm/types.h>
 #include <asm/posix_types.h>
 
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index c001766adcbc..4c24daa43bac 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1656,22 +1656,30 @@ union bpf_attr {
  * 		networking traffic statistics as it provides a global socket
  * 		identifier that can be assumed unique.
  * 	Return
- * 		A 8-byte long non-decreasing number on success, or 0 if the
- * 		socket field is missing inside *skb*.
+ * 		A 8-byte long unique number on success, or 0 if the socket
+ * 		field is missing inside *skb*.
  *
  * u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx)
  * 	Description
  * 		Equivalent to bpf_get_socket_cookie() helper that accepts
  * 		*skb*, but gets socket from **struct bpf_sock_addr** context.
  * 	Return
- * 		A 8-byte long non-decreasing number.
+ * 		A 8-byte long unique number.
  *
  * u64 bpf_get_socket_cookie(struct bpf_sock_ops *ctx)
  * 	Description
  * 		Equivalent to **bpf_get_socket_cookie**\ () helper that accepts
  * 		*skb*, but gets socket from **struct bpf_sock_ops** context.
  * 	Return
- * 		A 8-byte long non-decreasing number.
+ * 		A 8-byte long unique number.
+ *
+ * u64 bpf_get_socket_cookie(struct sock *sk)
+ * 	Description
+ * 		Equivalent to **bpf_get_socket_cookie**\ () helper that accepts
+ * 		*sk*, but gets socket from a BTF **struct sock**. This helper
+ * 		also works for sleepable programs.
+ * 	Return
+ * 		A 8-byte long unique number or 0 if *sk* is NULL.
  *
  * u32 bpf_get_socket_uid(struct sk_buff *skb)
  * 	Return
@@ -2231,6 +2239,9 @@ union bpf_attr {
  *		* > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the
  *		  packet is not forwarded or needs assist from full stack
  *
+ *		If lookup fails with BPF_FIB_LKUP_RET_FRAG_NEEDED, then the MTU
+ *		was exceeded and output params->mtu_result contains the MTU.
+ *
  * long bpf_sock_hash_update(struct bpf_sock_ops *skops, struct bpf_map *map, void *key, u64 flags)
  *	Description
  *		Add an entry to, or update a sockhash *map* referencing sockets.
@@ -3836,6 +3847,69 @@ union bpf_attr {
  *	Return
  *		A pointer to a struct socket on success or NULL if the file is
  *		not a socket.
+ *
+ * long bpf_check_mtu(void *ctx, u32 ifindex, u32 *mtu_len, s32 len_diff, u64 flags)
+ *	Description
+
+ *		Check ctx packet size against exceeding MTU of net device (based
+ *		on *ifindex*).  This helper will likely be used in combination
+ *		with helpers that adjust/change the packet size.
+ *
+ *		The argument *len_diff* can be used for querying with a planned
+ *		size change. This allows to check MTU prior to changing packet
+ *		ctx. Providing an *len_diff* adjustment that is larger than the
+ *		actual packet size (resulting in negative packet size) will in
+ *		principle not exceed the MTU, why it is not considered a
+ *		failure.  Other BPF-helpers are needed for performing the
+ *		planned size change, why the responsability for catch a negative
+ *		packet size belong in those helpers.
+ *
+ *		Specifying *ifindex* zero means the MTU check is performed
+ *		against the current net device.  This is practical if this isn't
+ *		used prior to redirect.
+ *
+ *		The Linux kernel route table can configure MTUs on a more
+ *		specific per route level, which is not provided by this helper.
+ *		For route level MTU checks use the **bpf_fib_lookup**\ ()
+ *		helper.
+ *
+ *		*ctx* is either **struct xdp_md** for XDP programs or
+ *		**struct sk_buff** for tc cls_act programs.
+ *
+ *		The *flags* argument can be a combination of one or more of the
+ *		following values:
+ *
+ *		**BPF_MTU_CHK_SEGS**
+ *			This flag will only works for *ctx* **struct sk_buff**.
+ *			If packet context contains extra packet segment buffers
+ *			(often knows as GSO skb), then MTU check is harder to
+ *			check at this point, because in transmit path it is
+ *			possible for the skb packet to get re-segmented
+ *			(depending on net device features).  This could still be
+ *			a MTU violation, so this flag enables performing MTU
+ *			check against segments, with a different violation
+ *			return code to tell it apart. Check cannot use len_diff.
+ *
+ *		On return *mtu_len* pointer contains the MTU value of the net
+ *		device.  Remember the net device configured MTU is the L3 size,
+ *		which is returned here and XDP and TX length operate at L2.
+ *		Helper take this into account for you, but remember when using
+ *		MTU value in your BPF-code.  On input *mtu_len* must be a valid
+ *		pointer and be initialized (to zero), else verifier will reject
+ *		BPF program.
+ *
+ *	Return
+ *		* 0 on success, and populate MTU value in *mtu_len* pointer.
+ *
+ *		* < 0 if any input argument is invalid (*mtu_len* not updated)
+ *
+ *		MTU violations return positive values, but also populate MTU
+ *		value in *mtu_len* pointer, as this can be needed for
+ *		implementing PMTU handing:
+ *
+ *		* **BPF_MTU_CHK_RET_FRAG_NEEDED**
+ *		* **BPF_MTU_CHK_RET_SEGS_TOOBIG**
+ *
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -4001,6 +4075,7 @@ union bpf_attr {
 	FN(ktime_get_coarse_ns),	\
 	FN(ima_inode_hash),		\
 	FN(sock_from_file),		\
+	FN(check_mtu),			\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
@@ -4501,6 +4576,7 @@ struct bpf_prog_info {
 	__aligned_u64 prog_tags;
 	__u64 run_time_ns;
 	__u64 run_cnt;
+	__u64 recursion_misses;
 } __attribute__((aligned(8)));
 
 struct bpf_map_info {
@@ -4981,9 +5057,13 @@ struct bpf_fib_lookup {
 	__be16	sport;
 	__be16	dport;
 
-	/* total length of packet from network header - used for MTU check */
-	__u16	tot_len;
+	union {	/* used for MTU check */
+		/* input to lookup */
+		__u16	tot_len; /* L3 length from network hdr (iph->tot_len) */
 
+		/* output: MTU value */
+		__u16	mtu_result;
+	};
 	/* input: L3 device index for lookup
 	 * output: device index from FIB lookup
 	 */
@@ -5029,6 +5109,17 @@ struct bpf_redir_neigh {
 	};
 };
 
+/* bpf_check_mtu flags*/
+enum  bpf_check_mtu_flags {
+	BPF_MTU_CHK_SEGS  = (1U << 0),
+};
+
+enum bpf_check_mtu_ret {
+	BPF_MTU_CHK_RET_SUCCESS,      /* check and lookup successful */
+	BPF_MTU_CHK_RET_FRAG_NEEDED,  /* fragmentation required to fwd */
+	BPF_MTU_CHK_RET_SEGS_TOOBIG,  /* GSO re-segmentation needed to fwd */
+};
+
 enum bpf_task_fd_type {
 	BPF_FD_TYPE_RAW_TRACEPOINT,	/* tp name */
 	BPF_FD_TYPE_TRACEPOINT,		/* tp name */
diff --git a/tools/include/uapi/linux/bpf_perf_event.h b/tools/include/uapi/linux/bpf_perf_event.h
index 8f95303f9d80..eb1b9d21250c 100644
--- a/tools/include/uapi/linux/bpf_perf_event.h
+++ b/tools/include/uapi/linux/bpf_perf_event.h
@@ -13,6 +13,7 @@
 struct bpf_perf_event_data {
 	bpf_user_pt_regs_t regs;
 	__u64 sample_period;
+	__u64 addr;
 };
 
 #endif /* _UAPI__LINUX_BPF_PERF_EVENT_H__ */
diff --git a/tools/include/uapi/linux/tcp.h b/tools/include/uapi/linux/tcp.h
new file mode 100644
index 000000000000..13ceeb395eb8
--- /dev/null
+++ b/tools/include/uapi/linux/tcp.h
@@ -0,0 +1,357 @@
+/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Definitions for the TCP protocol.
+ *
+ * Version:	@(#)tcp.h	1.0.2	04/28/93
+ *
+ * Author:	Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ */
+#ifndef _UAPI_LINUX_TCP_H
+#define _UAPI_LINUX_TCP_H
+
+#include <linux/types.h>
+#include <asm/byteorder.h>
+#include <linux/socket.h>
+
+struct tcphdr {
+	__be16	source;
+	__be16	dest;
+	__be32	seq;
+	__be32	ack_seq;
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+	__u16	res1:4,
+		doff:4,
+		fin:1,
+		syn:1,
+		rst:1,
+		psh:1,
+		ack:1,
+		urg:1,
+		ece:1,
+		cwr:1;
+#elif defined(__BIG_ENDIAN_BITFIELD)
+	__u16	doff:4,
+		res1:4,
+		cwr:1,
+		ece:1,
+		urg:1,
+		ack:1,
+		psh:1,
+		rst:1,
+		syn:1,
+		fin:1;
+#else
+#error	"Adjust your <asm/byteorder.h> defines"
+#endif	
+	__be16	window;
+	__sum16	check;
+	__be16	urg_ptr;
+};
+
+/*
+ *	The union cast uses a gcc extension to avoid aliasing problems
+ *  (union is compatible to any of its members)
+ *  This means this part of the code is -fstrict-aliasing safe now.
+ */
+union tcp_word_hdr { 
+	struct tcphdr hdr;
+	__be32 		  words[5];
+}; 
+
+#define tcp_flag_word(tp) ( ((union tcp_word_hdr *)(tp))->words [3]) 
+
+enum { 
+	TCP_FLAG_CWR = __constant_cpu_to_be32(0x00800000),
+	TCP_FLAG_ECE = __constant_cpu_to_be32(0x00400000),
+	TCP_FLAG_URG = __constant_cpu_to_be32(0x00200000),
+	TCP_FLAG_ACK = __constant_cpu_to_be32(0x00100000),
+	TCP_FLAG_PSH = __constant_cpu_to_be32(0x00080000),
+	TCP_FLAG_RST = __constant_cpu_to_be32(0x00040000),
+	TCP_FLAG_SYN = __constant_cpu_to_be32(0x00020000),
+	TCP_FLAG_FIN = __constant_cpu_to_be32(0x00010000),
+	TCP_RESERVED_BITS = __constant_cpu_to_be32(0x0F000000),
+	TCP_DATA_OFFSET = __constant_cpu_to_be32(0xF0000000)
+}; 
+
+/*
+ * TCP general constants
+ */
+#define TCP_MSS_DEFAULT		 536U	/* IPv4 (RFC1122, RFC2581) */
+#define TCP_MSS_DESIRED		1220U	/* IPv6 (tunneled), EDNS0 (RFC3226) */
+
+/* TCP socket options */
+#define TCP_NODELAY		1	/* Turn off Nagle's algorithm. */
+#define TCP_MAXSEG		2	/* Limit MSS */
+#define TCP_CORK		3	/* Never send partially complete segments */
+#define TCP_KEEPIDLE		4	/* Start keeplives after this period */
+#define TCP_KEEPINTVL		5	/* Interval between keepalives */
+#define TCP_KEEPCNT		6	/* Number of keepalives before death */
+#define TCP_SYNCNT		7	/* Number of SYN retransmits */
+#define TCP_LINGER2		8	/* Life time of orphaned FIN-WAIT-2 state */
+#define TCP_DEFER_ACCEPT	9	/* Wake up listener only when data arrive */
+#define TCP_WINDOW_CLAMP	10	/* Bound advertised window */
+#define TCP_INFO		11	/* Information about this connection. */
+#define TCP_QUICKACK		12	/* Block/reenable quick acks */
+#define TCP_CONGESTION		13	/* Congestion control algorithm */
+#define TCP_MD5SIG		14	/* TCP MD5 Signature (RFC2385) */
+#define TCP_THIN_LINEAR_TIMEOUTS 16      /* Use linear timeouts for thin streams*/
+#define TCP_THIN_DUPACK         17      /* Fast retrans. after 1 dupack */
+#define TCP_USER_TIMEOUT	18	/* How long for loss retry before timeout */
+#define TCP_REPAIR		19	/* TCP sock is under repair right now */
+#define TCP_REPAIR_QUEUE	20
+#define TCP_QUEUE_SEQ		21
+#define TCP_REPAIR_OPTIONS	22
+#define TCP_FASTOPEN		23	/* Enable FastOpen on listeners */
+#define TCP_TIMESTAMP		24
+#define TCP_NOTSENT_LOWAT	25	/* limit number of unsent bytes in write queue */
+#define TCP_CC_INFO		26	/* Get Congestion Control (optional) info */
+#define TCP_SAVE_SYN		27	/* Record SYN headers for new connections */
+#define TCP_SAVED_SYN		28	/* Get SYN headers recorded for connection */
+#define TCP_REPAIR_WINDOW	29	/* Get/set window parameters */
+#define TCP_FASTOPEN_CONNECT	30	/* Attempt FastOpen with connect */
+#define TCP_ULP			31	/* Attach a ULP to a TCP connection */
+#define TCP_MD5SIG_EXT		32	/* TCP MD5 Signature with extensions */
+#define TCP_FASTOPEN_KEY	33	/* Set the key for Fast Open (cookie) */
+#define TCP_FASTOPEN_NO_COOKIE	34	/* Enable TFO without a TFO cookie */
+#define TCP_ZEROCOPY_RECEIVE	35
+#define TCP_INQ			36	/* Notify bytes available to read as a cmsg on read */
+
+#define TCP_CM_INQ		TCP_INQ
+
+#define TCP_TX_DELAY		37	/* delay outgoing packets by XX usec */
+
+
+#define TCP_REPAIR_ON		1
+#define TCP_REPAIR_OFF		0
+#define TCP_REPAIR_OFF_NO_WP	-1	/* Turn off without window probes */
+
+struct tcp_repair_opt {
+	__u32	opt_code;
+	__u32	opt_val;
+};
+
+struct tcp_repair_window {
+	__u32	snd_wl1;
+	__u32	snd_wnd;
+	__u32	max_window;
+
+	__u32	rcv_wnd;
+	__u32	rcv_wup;
+};
+
+enum {
+	TCP_NO_QUEUE,
+	TCP_RECV_QUEUE,
+	TCP_SEND_QUEUE,
+	TCP_QUEUES_NR,
+};
+
+/* why fastopen failed from client perspective */
+enum tcp_fastopen_client_fail {
+	TFO_STATUS_UNSPEC, /* catch-all */
+	TFO_COOKIE_UNAVAILABLE, /* if not in TFO_CLIENT_NO_COOKIE mode */
+	TFO_DATA_NOT_ACKED, /* SYN-ACK did not ack SYN data */
+	TFO_SYN_RETRANSMITTED, /* SYN-ACK did not ack SYN data after timeout */
+};
+
+/* for TCP_INFO socket option */
+#define TCPI_OPT_TIMESTAMPS	1
+#define TCPI_OPT_SACK		2
+#define TCPI_OPT_WSCALE		4
+#define TCPI_OPT_ECN		8 /* ECN was negociated at TCP session init */
+#define TCPI_OPT_ECN_SEEN	16 /* we received at least one packet with ECT */
+#define TCPI_OPT_SYN_DATA	32 /* SYN-ACK acked data in SYN sent or rcvd */
+
+/*
+ * Sender's congestion state indicating normal or abnormal situations
+ * in the last round of packets sent. The state is driven by the ACK
+ * information and timer events.
+ */
+enum tcp_ca_state {
+	/*
+	 * Nothing bad has been observed recently.
+	 * No apparent reordering, packet loss, or ECN marks.
+	 */
+	TCP_CA_Open = 0,
+#define TCPF_CA_Open	(1<<TCP_CA_Open)
+	/*
+	 * The sender enters disordered state when it has received DUPACKs or
+	 * SACKs in the last round of packets sent. This could be due to packet
+	 * loss or reordering but needs further information to confirm packets
+	 * have been lost.
+	 */
+	TCP_CA_Disorder = 1,
+#define TCPF_CA_Disorder (1<<TCP_CA_Disorder)
+	/*
+	 * The sender enters Congestion Window Reduction (CWR) state when it
+	 * has received ACKs with ECN-ECE marks, or has experienced congestion
+	 * or packet discard on the sender host (e.g. qdisc).
+	 */
+	TCP_CA_CWR = 2,
+#define TCPF_CA_CWR	(1<<TCP_CA_CWR)
+	/*
+	 * The sender is in fast recovery and retransmitting lost packets,
+	 * typically triggered by ACK events.
+	 */
+	TCP_CA_Recovery = 3,
+#define TCPF_CA_Recovery (1<<TCP_CA_Recovery)
+	/*
+	 * The sender is in loss recovery triggered by retransmission timeout.
+	 */
+	TCP_CA_Loss = 4
+#define TCPF_CA_Loss	(1<<TCP_CA_Loss)
+};
+
+struct tcp_info {
+	__u8	tcpi_state;
+	__u8	tcpi_ca_state;
+	__u8	tcpi_retransmits;
+	__u8	tcpi_probes;
+	__u8	tcpi_backoff;
+	__u8	tcpi_options;
+	__u8	tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
+	__u8	tcpi_delivery_rate_app_limited:1, tcpi_fastopen_client_fail:2;
+
+	__u32	tcpi_rto;
+	__u32	tcpi_ato;
+	__u32	tcpi_snd_mss;
+	__u32	tcpi_rcv_mss;
+
+	__u32	tcpi_unacked;
+	__u32	tcpi_sacked;
+	__u32	tcpi_lost;
+	__u32	tcpi_retrans;
+	__u32	tcpi_fackets;
+
+	/* Times. */
+	__u32	tcpi_last_data_sent;
+	__u32	tcpi_last_ack_sent;     /* Not remembered, sorry. */
+	__u32	tcpi_last_data_recv;
+	__u32	tcpi_last_ack_recv;
+
+	/* Metrics. */
+	__u32	tcpi_pmtu;
+	__u32	tcpi_rcv_ssthresh;
+	__u32	tcpi_rtt;
+	__u32	tcpi_rttvar;
+	__u32	tcpi_snd_ssthresh;
+	__u32	tcpi_snd_cwnd;
+	__u32	tcpi_advmss;
+	__u32	tcpi_reordering;
+
+	__u32	tcpi_rcv_rtt;
+	__u32	tcpi_rcv_space;
+
+	__u32	tcpi_total_retrans;
+
+	__u64	tcpi_pacing_rate;
+	__u64	tcpi_max_pacing_rate;
+	__u64	tcpi_bytes_acked;    /* RFC4898 tcpEStatsAppHCThruOctetsAcked */
+	__u64	tcpi_bytes_received; /* RFC4898 tcpEStatsAppHCThruOctetsReceived */
+	__u32	tcpi_segs_out;	     /* RFC4898 tcpEStatsPerfSegsOut */
+	__u32	tcpi_segs_in;	     /* RFC4898 tcpEStatsPerfSegsIn */
+
+	__u32	tcpi_notsent_bytes;
+	__u32	tcpi_min_rtt;
+	__u32	tcpi_data_segs_in;	/* RFC4898 tcpEStatsDataSegsIn */
+	__u32	tcpi_data_segs_out;	/* RFC4898 tcpEStatsDataSegsOut */
+
+	__u64   tcpi_delivery_rate;
+
+	__u64	tcpi_busy_time;      /* Time (usec) busy sending data */
+	__u64	tcpi_rwnd_limited;   /* Time (usec) limited by receive window */
+	__u64	tcpi_sndbuf_limited; /* Time (usec) limited by send buffer */
+
+	__u32	tcpi_delivered;
+	__u32	tcpi_delivered_ce;
+
+	__u64	tcpi_bytes_sent;     /* RFC4898 tcpEStatsPerfHCDataOctetsOut */
+	__u64	tcpi_bytes_retrans;  /* RFC4898 tcpEStatsPerfOctetsRetrans */
+	__u32	tcpi_dsack_dups;     /* RFC4898 tcpEStatsStackDSACKDups */
+	__u32	tcpi_reord_seen;     /* reordering events seen */
+
+	__u32	tcpi_rcv_ooopack;    /* Out-of-order packets received */
+
+	__u32	tcpi_snd_wnd;	     /* peer's advertised receive window after
+				      * scaling (bytes)
+				      */
+};
+
+/* netlink attributes types for SCM_TIMESTAMPING_OPT_STATS */
+enum {
+	TCP_NLA_PAD,
+	TCP_NLA_BUSY,		/* Time (usec) busy sending data */
+	TCP_NLA_RWND_LIMITED,	/* Time (usec) limited by receive window */
+	TCP_NLA_SNDBUF_LIMITED,	/* Time (usec) limited by send buffer */
+	TCP_NLA_DATA_SEGS_OUT,	/* Data pkts sent including retransmission */
+	TCP_NLA_TOTAL_RETRANS,	/* Data pkts retransmitted */
+	TCP_NLA_PACING_RATE,    /* Pacing rate in bytes per second */
+	TCP_NLA_DELIVERY_RATE,  /* Delivery rate in bytes per second */
+	TCP_NLA_SND_CWND,       /* Sending congestion window */
+	TCP_NLA_REORDERING,     /* Reordering metric */
+	TCP_NLA_MIN_RTT,        /* minimum RTT */
+	TCP_NLA_RECUR_RETRANS,  /* Recurring retransmits for the current pkt */
+	TCP_NLA_DELIVERY_RATE_APP_LMT, /* delivery rate application limited ? */
+	TCP_NLA_SNDQ_SIZE,	/* Data (bytes) pending in send queue */
+	TCP_NLA_CA_STATE,	/* ca_state of socket */
+	TCP_NLA_SND_SSTHRESH,	/* Slow start size threshold */
+	TCP_NLA_DELIVERED,	/* Data pkts delivered incl. out-of-order */
+	TCP_NLA_DELIVERED_CE,	/* Like above but only ones w/ CE marks */
+	TCP_NLA_BYTES_SENT,	/* Data bytes sent including retransmission */
+	TCP_NLA_BYTES_RETRANS,	/* Data bytes retransmitted */
+	TCP_NLA_DSACK_DUPS,	/* DSACK blocks received */
+	TCP_NLA_REORD_SEEN,	/* reordering events seen */
+	TCP_NLA_SRTT,		/* smoothed RTT in usecs */
+	TCP_NLA_TIMEOUT_REHASH, /* Timeout-triggered rehash attempts */
+	TCP_NLA_BYTES_NOTSENT,	/* Bytes in write queue not yet sent */
+	TCP_NLA_EDT,		/* Earliest departure time (CLOCK_MONOTONIC) */
+};
+
+/* for TCP_MD5SIG socket option */
+#define TCP_MD5SIG_MAXKEYLEN	80
+
+/* tcp_md5sig extension flags for TCP_MD5SIG_EXT */
+#define TCP_MD5SIG_FLAG_PREFIX		0x1	/* address prefix length */
+#define TCP_MD5SIG_FLAG_IFINDEX		0x2	/* ifindex set */
+
+struct tcp_md5sig {
+	struct __kernel_sockaddr_storage tcpm_addr;	/* address associated */
+	__u8	tcpm_flags;				/* extension flags */
+	__u8	tcpm_prefixlen;				/* address prefix */
+	__u16	tcpm_keylen;				/* key length */
+	int	tcpm_ifindex;				/* device index for scope */
+	__u8	tcpm_key[TCP_MD5SIG_MAXKEYLEN];		/* key (binary) */
+};
+
+/* INET_DIAG_MD5SIG */
+struct tcp_diag_md5sig {
+	__u8	tcpm_family;
+	__u8	tcpm_prefixlen;
+	__u16	tcpm_keylen;
+	__be32	tcpm_addr[4];
+	__u8	tcpm_key[TCP_MD5SIG_MAXKEYLEN];
+};
+
+/* setsockopt(fd, IPPROTO_TCP, TCP_ZEROCOPY_RECEIVE, ...) */
+
+#define TCP_RECEIVE_ZEROCOPY_FLAG_TLB_CLEAN_HINT 0x1
+struct tcp_zerocopy_receive {
+	__u64 address;		/* in: address of mapping */
+	__u32 length;		/* in/out: number of bytes to map/mapped */
+	__u32 recv_skip_hint;	/* out: amount of bytes to skip */
+	__u32 inq; /* out: amount of bytes in read queue */
+	__s32 err; /* out: socket error */
+	__u64 copybuf_address;	/* in: copybuf address (small reads) */
+	__s32 copybuf_len; /* in/out: copybuf bytes avail/used or error */
+	__u32 flags; /* in: flags */
+};
+#endif /* _UAPI_LINUX_TCP_H */