Sockets 使用NASM和TCP套接字

我试图通过一些Unix系统调用自学一些NASM x86汇编。我正在尝试创建一个简单的TCP服务器，在执行send（）命令之前，我一直在编写代码。我可以通过telnet连接，但一旦我的代码到达试图向客户端发送响应的点，我就会收到SEGFULT

这是产生segfault的代码段：

; push on to stack for send
push    dword   0
push    dword   [start_len]
push    dword   [start]
push    dword   [socket]

; send something back
; THIS IS WHERE THE SEGFAULT OCCURS
mov eax,102
mov ebx,9 ; send is 9
mov ecx,esp
int 80h

如果有人想看的话，这里有完整的源代码。任何帮助都将不胜感激

; constants go here
section .data
    start: db 'Starting Socket...',0
    start_len: equ $-start

; variables go here
section .bss
    socket: resd   1 ; store the fd for the socket
    socket_address: resd    2 ; socket address

; starttttt
section .text
    global _start

open_socket:

    ; print we are starting
    mov eax,4
    mov ebx,1
    mov ecx,start
    mov edx,start_len
    int 80h

    ; push values to stack to make call
    ; values go in in opposite order, so when they are popped
    ; it is the correct order
    ; below is for a tcp socket
    push    dword   6
    push    dword   1
    push    dword   2

    ; make call to open socket
    mov eax,102 ; 102 is the call to open socket
    mov ebx,1 ; sub call, socket()
    mov ecx,esp
    int 80h

    ; store the file descriptor for the socket
    mov dword[socket],eax

    ; this is the socket address to bind to
    push    dword   0x00000000 ; localhost (127.0.0.1)
    push    dword   0x2823 ; port 9000
    push    word    2 ; AF_INET (IPv4)
    mov [socket_address],esp ; move to our socket address variable

    ; setup parameters for bind call bind(socket, socket_address, 16)
    push    dword  16
    push    dword   [socket_address]
    push    dword   [socket]

    ; call subcall for socket to bind
    mov eax,102; sys_socket 
    mov ebx,2 ; subcall 2 = bind()
    mov ecx,esp ; push vars from stack to params
    int 80h

    ; setup parameters for listen()
    push    byte    20
    push    dword   [socket]

    ; call listen()
    mov eax,102 ; socket call
    mov ebx,4 ; subcall listen()
    mov ecx,esp ; move stack as variables
    int 80h

    ; now we have to accept incoming connections...
    ; setup the call
    push    0
    push    0
    push    dword   [socket]

    ; call accept()
    mov eax,102
    mov ebx,5
    mov ecx,esp
    int 80h

    ; push on to stack for send
    push    dword   0
    push    dword   [start_len]
    push    dword   [start]
    push    dword   [socket]

    ; send something back
    ; THIS IS WHERE THE SEGFAULT OCCURS
    mov eax,102
    mov ebx,9 ; send is 9
    mov ecx,esp
    int 80h

; function to exit the program
exit:
    mov eax,1
    mov ebx,0
    int 80h

; main function to be called
_start:

    ; open it
    call open_socket

---

使用

int 80h

而不是从套接字库中调用

send

和

recv

有什么原因吗？

[start]

是内存的内容（'Star'）。同样地

[start\u len]

。我想你想在这两个地方都丢失“[]”。@FrankKotler这会删除segfault，但在我远程登录时不会返回任何内容。你是对的，因为它在寻找指针char*而不是值。@greatwolf我不太清楚你的意思。这是从系统调用中调用send命令（102子调用9）。@Eric您的“端口”只希望是“word”（big-endian，如您所知）。我不认为你的“环回”地址是对的-我把它定为7F000001h，但是big endian，那么10007Fh？