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c++ - 在 Windows 上使用 Boost.Asio 的半并发 ICMP ping

转载 作者:太空狗 更新时间:2023-10-29 22:59:23 28 4
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我修改了例子http://www.boost.org/doc/libs/1_51_0/doc/html/boost_asio/example/icmp/ping.cpp 关于如何定期 ping 主机以同时 ping 多台主机。首先,创建所有主机的请求并将其发送到套接字。然后在第二阶段收集所有响应,直到计时器到期。

3个客户端的修改示例:

// Headers from ping example:
// http://www.boost.org/doc/libs/1_51_0/doc/html/boost_asio/example/icmp/
#include "icmp_header.hpp"
#include "ipv4_header.hpp"

#include <boost/asio.hpp>
#include <iostream>

using boost::asio::ip::icmp;
using boost::asio::deadline_timer;
using boost::asio::io_service;
using boost::asio::streambuf;
using boost::system::error_code;
using std::cout;
using std::endl;
namespace posix_time = boost::posix_time;

static const std::string BODY = "ping";
static const auto PROCESS = GetCurrentProcessId();

static int gSequence;
static io_service gService;
static icmp::socket gSocket(gService, icmp::v4());
static deadline_timer gTimer(gService);
static streambuf gReply;
static icmp::endpoint gReceiver;

void StartReceive()
{
gSocket.async_receive_from(gReply.prepare(65536), gReceiver,
[&](const error_code& error, size_t length)
{
gReply.commit(length);

ipv4_header ipv4Hdr;
icmp_header icmpHdr;
std::string body(BODY.size(), 0);

std::istream is(&gReply);
is >> ipv4Hdr >> icmpHdr;
is.read(&body[0], BODY.size());

auto ip = ipv4Hdr.source_address().to_string();
auto rc = gReceiver.address().to_string();
auto id = icmpHdr.identifier();
auto process = PROCESS;
auto sn = icmpHdr.sequence_number();
auto type = icmpHdr.type();

cout << " Length = " << length << endl;
cout << " Error = " << error << endl;
cout << " IP checksum = " << ipv4Hdr.header_checksum() << endl;
cout << " IP address = " << ip << endl;
cout << " Receiver address = " << rc << endl;
cout << " ICMP identification = " << id << endl;
cout << " ICMP type = " << (int)type << endl;
cout << " Process = " << process << endl;
cout << " Sequence = " << sn << endl;

if (is
&& icmpHdr.type() == icmp_header::echo_reply
&& icmpHdr.identifier() == PROCESS
&& icmpHdr.sequence_number() == gSequence
&& body == BODY)
{
cout << " > " << ip << endl;
}

cout << endl;

gReply.consume(length);

StartReceive();
});
}

int main()
{
icmp::resolver resolver(gService);

icmp_header echoRequest;
echoRequest.type(icmp_header::echo_request);
echoRequest.identifier(PROCESS);

for (gSequence = 0; gSequence < 3; ++gSequence)
{
cout << "----------------------------------------------------------" << endl;
cout << "Iteration = " << gSequence << endl;
cout << "----------------------------------------------------------" << endl;

echoRequest.sequence_number(gSequence);
compute_checksum(echoRequest, BODY.begin(), BODY.end());

streambuf request;
std::ostream os(&request);
os << echoRequest << BODY;

gService.reset();

StartReceive();

std::vector<std::string> pool
{
"10.170.110.29",
"10.170.97.39",
"10.170.7.52"
};

for (const auto & ip : pool)
{
icmp::resolver::query query(icmp::v4(), ip, "");
auto dest = *resolver.resolve(query);

gSocket.send_to(request.data(), dest);
}

gTimer.expires_from_now(posix_time::millisec(2000));
gTimer.async_wait([&](const error_code& error) { gService.stop(); });

gService.run();
gReply.commit(gReply.size());
gReply.consume(gReply.size());
}

return 0;
}

尽管收到的第一个数据包的长度始终为零,但第一次迭代 (0) 每次都按预期工作。然而,在所有后续迭代中,来自一个或多个客户端的响应不会被传递,而是来自另一个客户端的响应会被多次传递。使用 Wireshark,我可以看到示例中的所有主机都非常迅速地发送了一个对请求的响应。

这是生成的输出之一:

----------------------------------------------------------
Iteration = 0
----------------------------------------------------------
Length = 0
Error = system:10022
IP checksum = 0
IP address = 0.0.0.0
Receiver address = 0.0.0.0
ICMP identification = 0
ICMP type = 0
Process = 20464
Sequence = 0

Length = 32
Error = system:0
IP checksum = 595
IP address = 10.170.97.39
Receiver address = 10.170.97.39
ICMP identification = 20464
ICMP type = 0
Process = 20464
Sequence = 0
> 10.170.97.39

Length = 32
Error = system:0
IP checksum = 31034
IP address = 10.170.110.29
Receiver address = 10.170.110.29
ICMP identification = 20464
ICMP type = 0
Process = 20464
Sequence = 0
> 10.170.110.29

Length = 32
Error = system:0
IP checksum = 51432
IP address = 10.170.7.52
Receiver address = 10.170.7.52
ICMP identification = 20464
ICMP type = 0
Process = 20464
Sequence = 0
> 10.170.7.52

----------------------------------------------------------
Iteration = 1
----------------------------------------------------------
Length = 32
Error = system:0
IP checksum = 594
IP address = 10.170.97.39
Receiver address = 10.170.97.39
ICMP identification = 20464
ICMP type = 0
Process = 20464
Sequence = 1
> 10.170.97.39

Length = 32
Error = system:0
IP checksum = 51419
IP address = 10.170.7.52
Receiver address = 10.170.7.52
ICMP identification = 20464
ICMP type = 0
Process = 20464
Sequence = 1
> 10.170.7.52

Length = 32
Error = system:0
IP checksum = 51419
IP address = 10.170.7.52
Receiver address = 10.170.7.52
ICMP identification = 20464
ICMP type = 0
Process = 20464
Sequence = 1
> 10.170.7.52

----------------------------------------------------------
Iteration = 2
----------------------------------------------------------
Length = 32
Error = system:0
IP checksum = 593
IP address = 10.170.97.39
Receiver address = 10.170.97.39
ICMP identification = 20464
ICMP type = 0
Process = 20464
Sequence = 2
> 10.170.97.39

Length = 32
Error = system:0
IP checksum = 51407
IP address = 10.170.7.52
Receiver address = 10.170.7.52
ICMP identification = 20464
ICMP type = 0
Process = 20464
Sequence = 2
> 10.170.7.52

Length = 32
Error = system:0
IP checksum = 51407
IP address = 10.170.7.52
Receiver address = 10.170.7.52
ICMP identification = 20464
ICMP type = 0
Process = 20464
Sequence = 2
> 10.170.7.52

这是 Boost.Asio 的正确用法和行为吗?

谢谢

最佳答案

看起来不错。它似乎对我有用。

注意事项:

  • 在这里使用 streambuf 似乎过于复杂 - 我想知道 streambuf 的重用是否会导致重复发现相同的内容

  • 如果其中一个池地址解析为本地 NIC 地址(因为您将收到自己的 ICMP 数据包),这些东西可能会变得困惑

  • 您永远不会解析第一个匹配之外的任何地址,并且根本不检查解析是否有效;此外,您每次都解决(这可能是设计使然,但也可能是一个错误。DNS 请求也可能会干扰您的观察(特别是如果您有本地 DNS 缓存/网关?)。

    考虑使用 boost::asio::async_resolve 并可能将它从循环中取出,这样它就不会干扰计时。

这是一个简化的版本:

// Headers from ping example:
// http://www.boost.org/doc/libs/1_51_0/doc/html/boost_asio/example/icmp/
#include "icmp_header.hpp"
#include "ipv4_header.hpp"

#include <sys/types.h>
#include <unistd.h>
#include <boost/asio.hpp>
#include <iostream>
#include <sstream>

using boost::asio::ip::icmp;
using boost::asio::deadline_timer;
using boost::asio::io_service;
using boost::asio::streambuf;
using boost::system::error_code;
using std::cout;
using std::endl;
namespace posix_time = boost::posix_time;

static const std::string BODY = "ping";
static const auto PROCESS = getpid();

static int gSequence;
static io_service gService;
static icmp::socket gSocket(gService, icmp::v4());
static char gReply[65536];
static icmp::endpoint gReceiver;

void StartReceive() {
gSocket.async_receive_from(boost::asio::buffer(gReply), gReceiver, [&](const error_code &error, size_t length) {

ipv4_header ipv4Hdr;
icmp_header icmpHdr;
std::string body(BODY.size(), 0);

std::istringstream is(std::string(gReply, length));
is >> ipv4Hdr >> icmpHdr;
is.read(&body[0], BODY.size());

auto ip = ipv4Hdr.source_address().to_string();
auto rc = gReceiver.address().to_string();
auto id = icmpHdr.identifier();
auto process = PROCESS;
auto sn = icmpHdr.sequence_number();
auto type = icmpHdr.type();

cout << " Length=" << length <<
" Error=" << error <<
" IP checksum=" << ipv4Hdr.header_checksum() <<
" IP address=" << ip <<
" Receiver address=" << rc <<
" ICMP identification=" << id <<
" ICMP type=" << (int)type <<
" Process=" << process <<
" Sequence=" << sn << "\n";

if (is && icmpHdr.type() == icmp_header::echo_reply && icmpHdr.identifier() == PROCESS &&
icmpHdr.sequence_number() == gSequence && body == BODY) {
cout << " > " << ip << endl;
}

cout << endl;

StartReceive();
});
}

int main() {
icmp::resolver resolver(gService);

icmp_header echoRequest;
echoRequest.type(icmp_header::echo_request);
echoRequest.identifier(PROCESS);

for (gSequence = 0; gSequence < 3; ++gSequence) {
cout << "----------------------------------------------------------" << endl;
cout << "Iteration=" << gSequence << endl;
cout << "----------------------------------------------------------" << endl;

echoRequest.sequence_number(gSequence);
compute_checksum(echoRequest, BODY.begin(), BODY.end());

streambuf request;
std::ostream os(&request);
os << echoRequest << BODY;

gService.reset();

StartReceive();

for (std::string ip : { "www.msn.com", "www.google.com" }) {
icmp::resolver::query query(icmp::v4(), ip, "");
auto dest = *resolver.resolve(query);

gSocket.send_to(request.data(), dest);
std::cout << "Sent to " << dest.endpoint() << "\n";
}

deadline_timer gTimer(gService);
gTimer.expires_from_now(posix_time::millisec(2000));
gTimer.async_wait([&](error_code) { gService.stop(); });

gService.run();
}
}

打印,例如

----------------------------------------------------------
Iteration=0
----------------------------------------------------------
Sent to 204.79.197.203:0
Sent to 216.58.212.164:0
Length=32 Error=system:0 IP checksum=49241 IP address=204.79.197.203 Receiver address=204.79.197.203 ICMP identification=8041 ICMP type=0 Process=8041 Sequence=0
> 204.79.197.203

Length=32 Error=system:0 IP checksum=5449 IP address=216.58.212.164 Receiver address=216.58.212.164 ICMP identification=8041 ICMP type=0 Process=8041 Sequence=0
> 216.58.212.164

----------------------------------------------------------
Iteration=1
----------------------------------------------------------
Sent to 204.79.197.203:0
Sent to 216.58.212.164:0
Length=32 Error=system:0 IP checksum=49240 IP address=204.79.197.203 Receiver address=204.79.197.203 ICMP identification=8041 ICMP type=0 Process=8041 Sequence=1
> 204.79.197.203

Length=32 Error=system:0 IP checksum=5449 IP address=216.58.212.164 Receiver address=216.58.212.164 ICMP identification=8041 ICMP type=0 Process=8041 Sequence=1
> 216.58.212.164

----------------------------------------------------------
Iteration=2
----------------------------------------------------------
Sent to 204.79.197.203:0
Sent to 216.58.212.164:0
Length=32 Error=system:0 IP checksum=49239 IP address=204.79.197.203 Receiver address=204.79.197.203 ICMP identification=8041 ICMP type=0 Process=8041 Sequence=2
> 204.79.197.203

Length=32 Error=system:0 IP checksum=5449 IP address=216.58.212.164 Receiver address=216.58.212.164 ICMP identification=8041 ICMP type=0 Process=8041 Sequence=2
> 216.58.212.164

关于c++ - 在 Windows 上使用 Boost.Asio 的半并发 ICMP ping,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/37003947/

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