我的 STUN 绑定请求哪里出了问题

Question

我向 stun.l.google.com:19305 发送了 udp 请求，但我没有从 google 眩晕服务器收到任何响应。我省略了这段代码中的所有错误检查。我的程序挂在 recvfrom.

int stun_socket = socket(AF_INET, SOCK_DGRAM, 0);

struct sockaddr_in stun_client;
memset(&stun_client, 0, sizeof(stun_client));

stun_client.sin_family = AF_INET;
stun_client.sin_port = htons(local_port);

int rc = bind(stun_socket, (struct sockaddr *)&stun_client, sizeof(stun_client));

struct sockaddr_in stun_server;
memset(&stun_server, 0, sizeof(stun_server));

stun_server.sin_family = AF_INET;
stun_server.sin_port = htons(remote_port);
inet_pton(AF_INET, server, &stun_server.sin_addr);

typedef struct stun_header_tag {
    uint16_t message_type;
    uint16_t message_length;
    unsigned char transaction_id[16];
} stun_header_t;

stun_header_t header;
header.message_type = htons(0x0001); /* Binding Request */
header.message_length = htons(0);
*(int *)(&header.transaction_id[8]) = 0xFFEEFFEE; /* transaction id in the response should keep consistent with this one */

rc = sendto(stun_socket, (void *)&header, sizeof(header), 0, (struct sockaddr *)&stun_server, sizeof(stun_server));

char response[64];
rc = recvfrom(stun_socket, response, 64, 0, NULL, 0);

Answer 1

我猜你正在做类似或等效的事情来发送数据：

sendto(sock, &header, sizeof(header), (sockaddr*)&addr, addrlen);

如果是这种情况，您可能忘记将 message_type 值转换为网络字节顺序（大端）。

试试这个：

header.message_type = htons(0x0001);

但如果您想要更好的解决方案，并且可以使用 C++，请使用 Stuntman. You can generate a binding request as follows with the C++ class, CStunMessageBuilder, declared in the stuncore/stunbuilder.h 文件中内置的客户端库。

CStunMessageBuilder builder;
StunTransactionId transId;

builder.AddBindingRequestHeader();
builder.AddRandomTransactionId(&transID);
unsigned char* msg = builder.GetStream().GetDataPointerUnsafe();
size_t len = builder.GetStream().GetSize();

sendto(sock, msg, len, (sockaddr*)&addr, addrlen);

我的 STUN 绑定请求哪里出了问题

Where is wrong with my STUN Binding request

stun