Add a "fork" of musl as //fusl.

fusl/include/netinet/tcp.h

Index: fusl/include/netinet/tcp.h
diff --git a/fusl/include/netinet/tcp.h b/fusl/include/netinet/tcp.h
new file mode 100644
index 0000000000000000000000000000000000000000..52358c75bc359f7f556116a67ebbc907a89e1d4a
--- /dev/null
+++ b/fusl/include/netinet/tcp.h
@@ -0,0 +1,182 @@
+#ifndef _NETINET_TCP_H
+#define _NETINET_TCP_H
+
+#include <features.h>
+
+#define TCP_NODELAY 1
+#define TCP_MAXSEG	 2
+#define TCP_CORK	 3
+#define TCP_KEEPIDLE	 4
+#define TCP_KEEPINTVL	 5
+#define TCP_KEEPCNT	 6
+#define TCP_SYNCNT	 7
+#define TCP_LINGER2	 8
+#define TCP_DEFER_ACCEPT 9
+#define TCP_WINDOW_CLAMP 10
+#define TCP_INFO	 11
+#define	TCP_QUICKACK	 12
+#define TCP_CONGESTION	 13
+#define TCP_MD5SIG	 14
+#define TCP_THIN_LINEAR_TIMEOUTS 16
+#define TCP_THIN_DUPACK  17
+#define TCP_USER_TIMEOUT 18
+#define TCP_REPAIR       19
+#define TCP_REPAIR_QUEUE 20
+#define TCP_QUEUE_SEQ    21
+#define TCP_REPAIR_OPTIONS 22
+#define TCP_FASTOPEN     23
+#define TCP_TIMESTAMP    24
+#define TCP_NOTSENT_LOWAT 25
+
+#define TCP_ESTABLISHED  1
+#define TCP_SYN_SENT     2
+#define TCP_SYN_RECV     3
+#define TCP_FIN_WAIT1    4
+#define TCP_FIN_WAIT2    5
+#define TCP_TIME_WAIT    6
+#define TCP_CLOSE        7
+#define TCP_CLOSE_WAIT   8
+#define TCP_LAST_ACK     9
+#define TCP_LISTEN       10
+#define TCP_CLOSING      11
+
+#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+#define SOL_TCP 6
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <stdint.h>
+#include <endian.h>
+
+typedef uint32_t tcp_seq;
+
+#define TH_FIN 0x01
+#define TH_SYN 0x02
+#define TH_RST 0x04
+#define TH_PUSH 0x08
+#define TH_ACK 0x10
+#define TH_URG 0x20
+
+struct tcphdr {
+#ifdef _GNU_SOURCE
+#ifdef __GNUC__
+	__extension__
+#endif
+	union { struct {
+
+	uint16_t source;
+	uint16_t dest;
+	uint32_t seq;
+	uint32_t ack_seq;
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+	uint16_t res1:4;
+	uint16_t doff:4;
+	uint16_t fin:1;
+	uint16_t syn:1;
+	uint16_t rst:1;
+	uint16_t psh:1;
+	uint16_t ack:1;
+	uint16_t urg:1;
+	uint16_t res2:2;
+#else
+	uint16_t doff:4;
+	uint16_t res1:4;
+	uint16_t res2:2;
+	uint16_t urg:1;
+	uint16_t ack:1;
+	uint16_t psh:1;
+	uint16_t rst:1;
+	uint16_t syn:1;
+	uint16_t fin:1;
+#endif
+	uint16_t window;
+	uint16_t check;
+	uint16_t urg_ptr;
+
+	}; struct {
+#endif
+
+	uint16_t th_sport;
+	uint16_t th_dport;
+	uint32_t th_seq;
+	uint32_t th_ack;
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+	uint8_t th_x2:4;
+	uint8_t th_off:4;
+#else
+	uint8_t th_off:4;
+	uint8_t th_x2:4;
+#endif
+	uint8_t th_flags;
+	uint16_t th_win;
+	uint16_t th_sum;
+	uint16_t th_urp;
+
+#ifdef _GNU_SOURCE
+	}; };
+#endif
+};
+#endif
+
+#ifdef _GNU_SOURCE
+#define TCPI_OPT_TIMESTAMPS	1
+#define TCPI_OPT_SACK		2
+#define TCPI_OPT_WSCALE		4
+#define TCPI_OPT_ECN		8
+
+#define TCP_CA_Open		0
+#define TCP_CA_Disorder		1
+#define TCP_CA_CWR		2
+#define TCP_CA_Recovery		3
+#define TCP_CA_Loss		4
+
+struct tcp_info
+{
+	uint8_t tcpi_state;
+	uint8_t tcpi_ca_state;
+	uint8_t tcpi_retransmits;
+	uint8_t tcpi_probes;
+	uint8_t tcpi_backoff;
+	uint8_t tcpi_options;
+	uint8_t tcpi_snd_wscale : 4, tcpi_rcv_wscale : 4;
+	uint32_t tcpi_rto;
+	uint32_t tcpi_ato;
+	uint32_t tcpi_snd_mss;
+	uint32_t tcpi_rcv_mss;
+	uint32_t tcpi_unacked;
+	uint32_t tcpi_sacked;
+	uint32_t tcpi_lost;
+	uint32_t tcpi_retrans;
+	uint32_t tcpi_fackets;
+	uint32_t tcpi_last_data_sent;
+	uint32_t tcpi_last_ack_sent;
+	uint32_t tcpi_last_data_recv;
+	uint32_t tcpi_last_ack_recv;
+	uint32_t tcpi_pmtu;
+	uint32_t tcpi_rcv_ssthresh;
+	uint32_t tcpi_rtt;
+	uint32_t tcpi_rttvar;
+	uint32_t tcpi_snd_ssthresh;
+	uint32_t tcpi_snd_cwnd;
+	uint32_t tcpi_advmss;
+	uint32_t tcpi_reordering;
+	uint32_t tcpi_rcv_rtt;
+	uint32_t tcpi_rcv_space;
+	uint32_t tcpi_total_retrans;
+	uint64_t tcpi_pacing_rate;
+	uint64_t tcpi_max_pacing_rate;
+};
+
+#define TCP_MD5SIG_MAXKEYLEN    80
+
+struct tcp_md5sig
+{
+	struct sockaddr_storage tcpm_addr;
+	uint16_t __tcpm_pad1;
+	uint16_t tcpm_keylen;
+	uint32_t __tcpm_pad2;
+	uint8_t tcpm_key[TCP_MD5SIG_MAXKEYLEN];
+};
+
+#endif
+
+#endif