source: bootcd/isolinux/syslinux-6.03/gpxe/src/include/old_tcp.h

#ifndef _TCP_H
#define _TCP_H

#define TCP_INITIAL_TIMEOUT     (3*TICKS_PER_SEC)
#define TCP_MAX_TIMEOUT         (60*TICKS_PER_SEC)
#define TCP_MIN_TIMEOUT         (TICKS_PER_SEC)
#define TCP_MAX_RETRY           10
#define TCP_MAX_HEADER          ((int)sizeof(struct iphdr)+64)
#define TCP_MIN_WINDOW          (1500-TCP_MAX_HEADER)
#define TCP_MAX_WINDOW          (65535-TCP_MAX_HEADER)

#define FIN             1
#define SYN             2
#define RST             4
#define PSH             8
#define ACK             16
#define URG             32


struct tcphdr {
       uint16_t src;
       uint16_t dst;
       int32_t  seq;
       int32_t  ack;
       uint16_t ctrl;
       uint16_t window;
       uint16_t chksum;
       uint16_t urgent;
};

extern int tcp_transaction ( unsigned long destip, unsigned int destsock,
                             void *ptr,
                             int (*send)(int len, void *buf, void *ptr),
                             int (*recv)(int len, const void *buf, void *ptr));


#endif  /* _TCP_H */