C++ C++;WinSock2:connect()调用上的WSA\u无效\u句柄
你好 我是一个在高级语言方面有一定经验的程序员,但这是我第一次深入研究低级语言的套接字代码,所以请耐心听我说 我似乎在调用C++ C++;WinSock2:connect()调用上的WSA\u无效\u句柄,c++,windows,sockets,winsock,winsock2,C++,Windows,Sockets,Winsock,Winsock2,你好 我是一个在高级语言方面有一定经验的程序员,但这是我第一次深入研究低级语言的套接字代码,所以请耐心听我说 我似乎在调用connect()时出错。在我的主函数中,WSAGetLastError()打印这是错误号6,根据MSDN,它是WSA\u无效\u句柄。这似乎很奇怪,因为没有关于特定错误代码的详细信息(除非我是瞎子),而且我的谷歌搜索结果都是不确定的 我正在使用一个定制的socket\t结构,因为我的代码设计成(最终)跨平台的。从主代码页调用socket\u connect()函数 sock
connect()
时出错。在我的主函数中,WSAGetLastError()
打印这是错误号6,根据MSDN,它是WSA\u无效\u句柄
。这似乎很奇怪,因为没有关于特定错误代码的详细信息(除非我是瞎子),而且我的谷歌搜索结果都是不确定的
我正在使用一个定制的socket\t结构,因为我的代码设计成(最终)跨平台的。从主代码页调用socket\u connect()
函数
socket\t
定义:
typedef struct
{
//windows-specific
SOCKADDR_IN *addr_in;
u_long mode;
SOCKET socket;//acutal SOCKET structure
// General
bool listening;//set to true if actively listening
bool thread_terminate;//when boolean is set to true, listening thread terminates
void (*error_callback) (int);
http_response_t * response;
} socket_t;
socket\u connect()
函数:
//see socket_t definition in socket.h
//returns 0 on success, SOCKET_ERROR on WinSock failure, positive error code on ANSI DNS failure
int socket_connect(socket_t * sock, char * addr, int port)
{
//bear in mind sock is the custom socket_t structure. sock->socket is the actual SOCKET structure.
//pardon the nomenclature. rookie code.
//DNS lookup structures
struct addrinfo * res = NULL;// Result of the getaddrinfo() call
struct sockaddr_in * sockaddr_v4 = NULL;// IPv4 sockaddr structure
// So-called "hints" structure detailed in the getaddrinfo() MSDN page.
// I guess it contains information for the DNS lookup.
struct addrinfo hints;
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
//Perform DNS lookup
DWORD getaddrinfo_res = getaddrinfo(addr, "80\0", &hints, &res);//hard-code Port number for now...
if(getaddrinfo_res != 0) return getaddrinfo_res;//positive DNS error code
//debug information
std::cout << "DNS lookup responses:" << std::endl;
//for each
int i = 0;//counter
for(struct addrinfo * ptr = res; ptr != NULL; ptr = ptr->ai_next)
{
std::cout << "Response number " << i + 1 << std::endl;
std::cout << "Flags: " << ptr->ai_flags << std::endl;
std::cout << "Family: ";
switch(ptr->ai_family)
{
case AF_INET:
sockaddr_v4 = (struct sockaddr_in *) ptr->ai_addr;//set current address
sock->addr_in = sockaddr_v4;//set socket address
std::cout << "AF_INET (IPv4)" << std::endl;
std::cout << "Addr: " << inet_ntoa(sockaddr_v4->sin_addr) << std::endl;
break;
case AF_UNSPEC:
std::cout << "UNSPECIFIED" << std::endl;
break;
default:
std::cout << "UNKNOWN\t(" << ptr->ai_family << ")" << std::endl;
break;
}
i++;
}
//initialize actual SOCKET
sock->socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);// TCP/IP, stream-oriented, and TCP rather than UDP; respectively
if(sock->socket == INVALID_SOCKET) return SOCKET_ERROR;
//actual connection
std::cout << WSAGetLastError() << std::endl;
int connect_res = connect(sock->socket, (SOCKADDR *) sockaddr_v4, sizeof(sockaddr_v4));///have to convert SOCKADDR_IN to a SOCKADDR pointer here. Not sure why.
if(connect_res == SOCKET_ERROR) return SOCKET_ERROR;
//make nonblocking
/*
sock->mode = 1;
int ioctl = ioctlsocket(sock->socket, FIONBIO, &(sock->mode));//I/O Control Socket. Not sure what FIONBIO means. pointer to sock->mode = 1 ensures nonblockingness.
if(ioctl == SOCKET_ERROR) return SOCKET_ERROR;
*/// (include this?)
return 0;
}
谢谢你抽出时间!
-Jake您在呼叫connect时为自己传递了错误的大小 更改此项:
int connect_res = connect(sock->socket, (SOCKADDR *) sockaddr_v4, sizeof(sockaddr_v4));
// wrong size ^^^^^^^^^^^
为此:
int connect_res = connect(sock->socket, (SOCKADDR *) sockaddr_v4, sizeof(*sockaddr_v4));
// right size ^^^^^^^^^^^
除此之外,您的程序还有一个不同的bug,即
getaddrinfo()
返回的指针在sock
结构中的持久性。应按值将其复制到sock
拥有的内存中。它将适用于此示例,因为它是如此孤立,但它应该被更改。首先是一些琐碎的问题。你用@WhozCraig正确初始化WinSock了吗?@WhozCraig是的,我相信是的。啊,现在完全有道理了。非常感谢。
int connect_res = connect(sock->socket, (SOCKADDR *) sockaddr_v4, sizeof(*sockaddr_v4));
// right size ^^^^^^^^^^^