fopen,fprintf和fclose强制套接字连接结束

时间:2013-08-04 17:18:54

标签: c++ networking windows-8 windows-xp dll-injection

我有一个dll挂钩网络应用程序的recv功能。代码工作得很好(它使所有内容都被禁止),但是如果我将输出日志添加到文件中,连接会在一段时间后关闭(服务器端应用程序抛出错误“现有连接被远程强制关闭主办”)。

那个时间甚至不一样,有时几乎在初始化连接时关闭,有时我可以在关闭之前使用连接几秒钟。它不会给出任何错误或警告消息。如果我删除日志代码,应用程序运行正常。知道为什么会这样吗?我在Windows 8 x64中运行它

此外,即使删除日志代码,连接也会在windows xp x32中保持关闭状态。

这是recv钩子代码:

int __stdcall NewRecv(SOCKET socket, char *data, int datalen, int flags) {
    int result = 0;
    if(!IsLoginServerPacket(&socket)) {

        INT size = 0,opcode = 0,temp = 0,writer = 0,second_op = 0;
        do {
            size = 0;
            second_op = 0;
            temp = 0;
            writer = 0;

            while(temp < 2) {
                temp += recvPacket(socket,recv_gs_buffer+writer,2 - temp,flags);
                writer += temp;
            }

            size = (*(SHORT*)recv_gs_buffer) & 0xffff;

            // THIS IS THE LOG CODE
            FILE *f = fopen("debug.txt", "a");
            fprintf(f, "datalen=%d, size=%d\n", datalen, size);
            fclose(f);

            while(temp < size) {
                temp += recvPacket(socket,recv_gs_buffer+writer,size - temp,flags);
                writer += temp;
            }

            Decrypt(&gs_crypt,recv_gs_buffer+2,size-2);
            opcode = (*(recv_gs_buffer+2) & 0xff);

            if(opcode == EXTENDED_PROTOCOL) {
                second_op = *(SHORT*)(recv_gs_buffer + 3);
                second_op &= 0xffff;
                HandleGameServerPacket(second_op,recv_gs_buffer+2,size-2);
            }
        } while(second_op == 0x8a || second_op == 0x8b);

        if(opcode == 0x00) {
            SetKey(recv_gs_buffer+4,&gs_crypt);
            SetKey(recv_gs_buffer+4,&client_crypt);
        } else
            Crypt(&client_crypt,recv_gs_buffer+2,size-2);

        int i = 0;
        while(i < size) {
            data[i] = recv_gs_buffer[i];
            i++;
        }
        //memcpy(data,recv_gs_buffer,size);
        result = size;
    } else
        result = recvPacket(socket,data,datalen,flags);

    return result;
}

1 个答案:

答案 0 :(得分:0)

我刚刚发现了问题及其解决方案。

注入的应用程序正在非阻塞模式下配置套接字。任何一点延迟都使它抛出WSAEWOULDBLOCK(10035错误代码)。我必须做的就是修复它,如果我收到任何错误,请重试recv请求

INT val = 0;
while(temp < 2) {
    val = recvPacket(socket,recv_gs_buffer+writer,2 - temp,flags);
    if(val > 0) {
        temp += val;
                writer += temp;
    }
}

并且

val = 0;
while(temp < size) {
    val = recvPacket(socket,recv_gs_buffer+writer,size - temp,flags);
    if(val > 0) {
        temp += val;
                writer += temp;
    }
}