internal.h

#ifndef INTERNAL_H
#define INTERNAL_H

#define _GNU_SOURCE

#define _GNU_SOURCE         /* See feature_test_macros(7) */
      #include <sys/socket.h>

#include "Packets.h"

void us_internal_socket_context_link(struct us_socket_context_t *context, struct us_socket_t *s);
void us_internal_timer_sweep(struct us_loop_t *loop);
void us_internal_loop_link(struct us_loop_t *loop, struct us_socket_context_t *context);

struct us_socket_context_t {
    alignas(16) struct us_loop_t *loop;

    struct us_socket_t *(*on_open)(struct us_socket_t *s, int is_client, char *ip, int ip_length);
    struct us_socket_t *(*on_close)(struct us_socket_t *s);
    struct us_socket_t *(*on_data)(struct us_socket_t *s, char *data, int length);
    struct us_socket_t *(*on_writable)(struct us_socket_t *s);
    struct us_socket_t *(*on_socket_timeout)(struct us_socket_t *s);
    struct us_socket_t *(*on_end)(struct us_socket_t *s);

    /* Socket contexts form a link */
    struct us_socket_context_t *next;
    struct us_socket_context_t *prev;

    /* What are our listen_sockets */
    struct us_listen_socket_t *listen_socket;


    struct us_socket_t *head;
    struct us_socket_t *iterator;
};

struct us_listen_socket_t {
    int socket_ext_size;
    struct us_socket_context_t *context;

    /* What do we really listen to? */
    int port;
};

#include "uthash.h"

// 96 bit, 12 bytes (for now duplicated)
struct SOCKET_KEY {
    uint16_t srcPort, dstPort;
    uint32_t srcIp, dstIp;
};

struct us_socket_t {

    struct SOCKET_KEY key;

    // debug
    int packets;

    // largest seq we seen that is out of sync, or 0 if not seen
    uint32_t mostOutOfSync;

    // the initial seq, ack sent in first syn packet to us
    uint32_t initialRemoteSeq, initialHostSeq;


    //struct us_socket_t *next;

    void *userData;

    // per socket data
    uint32_t networkIp; // this is THEIR IP!
    uint16_t hostPort; // this is THEIR port

    // this is OUR IP!
    uint32_t networkDestinationIp;
    uint16_t hostDestinationPort;

    uint32_t hostAck;
    uint32_t hostSeq;


    /*enum {
        CLOSED,
        SYN_ACK_SENT,
        SYN_SENT,
        ESTABLISHED
    } state;*/

    int state;


    uint32_t originalHostAck;


    alignas(16) struct us_socket_context_t *context;

    int closed;
    int shutdown;
    int wants_writable;

    unsigned short timeout;

    struct us_socket_t *prev, *next;

    UT_hash_handle hh;
};

void us_internal_socket_context_send_packet(struct us_socket_context_t *context, uint32_t hostSeq, uint32_t hostAck, uint32_t networkDestIp, uint32_t networkSourceIp, int hostDestPort,
                 int hostSourcePort, int flagAck, int flagSyn, int flagFin, int flagRst, char *data, size_t length);

#include <stdio.h>
#include <string.h>
#include <sys/socket.h>
#include <stdlib.h>
#include <errno.h>
#include <netinet/tcp.h>
#include <netinet/ip.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>
#include <netinet/ip.h>
#include <sys/socket.h>
#include <time.h>

#include <sys/epoll.h>
#include <sys/timerfd.h>

struct us_loop_t {

    /* We only support one listen socket */
    alignas(16) struct us_listen_socket_t *listen_socket;

    /* The list of closed sockets */
    struct us_socket_t *close_list;

    // här sparar vi senaste skapade contextet
    struct us_socket_context_t *context;

    /* Post and pre callbacks */
    void (*pre_cb)(struct us_loop_t *loop);
    void (*post_cb)(struct us_loop_t *loop);

    void (*wakeup_cb)(struct us_loop_t *loop);

    // vi har

    int send_fd;

    int fd, epfd, timer;
    char *buffer[1024];
    size_t length[1024];
    struct mmsghdr msgs[1024];
    struct iovec iovecs[1024];

    struct iovec messages[1024];

    char *outBuffer[1024];
    int queuedBuffersNum;// = 0;

    // timeout and then
    struct timespec timeout;
    struct timeval then;

    // statistics
    int packets_out_of_order;
    int healed_sockets;
    int duplicated_packets;
    unsigned long long packets_received;

    // linked list of all contexts
    struct us_socket_context_t *head;
    struct us_socket_context_t *iterator;
};

// passing data from ip to tcp layer

void us_internal_socket_context_read_tcp(struct us_socket_t *s, struct us_socket_context_t *context, IpHeader *ipHeader, struct TcpHeader *tcpHeader, int length);

#endif // INTERNAL_H