- c - 在位数组中找到第一个零
- linux - Unix 显示有关匹配两种模式之一的文件的信息
- 正则表达式替换多个文件
- linux - 隐藏来自 xtrace 的命令
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/
#include using namespace std; class C{ private: int value; public: C(){ value = 0;
这个问题已经有答案了: What is the difference between char a[] = ?string?; and char *p = ?string?;? (8 个回答) 已关闭
关闭。此题需要details or clarity 。目前不接受答案。 想要改进这个问题吗?通过 editing this post 添加详细信息并澄清问题. 已关闭 7 年前。 此帖子已于 8 个月
除了调试之外,是否有任何针对 c、c++ 或 c# 的测试工具,其工作原理类似于将独立函数复制粘贴到某个文本框,然后在其他文本框中输入参数? 最佳答案 也许您会考虑单元测试。我推荐你谷歌测试和谷歌模拟
我想在第二台显示器中移动一个窗口 (HWND)。问题是我尝试了很多方法,例如将分辨率加倍或输入负值,但它永远无法将窗口放在我的第二台显示器上。 关于如何在 C/C++/c# 中执行此操作的任何线索 最
我正在寻找 C/C++/C## 中不同类型 DES 的现有实现。我的运行平台是Windows XP/Vista/7。 我正在尝试编写一个 C# 程序,它将使用 DES 算法进行加密和解密。我需要一些实
很难说出这里要问什么。这个问题模棱两可、含糊不清、不完整、过于宽泛或夸夸其谈,无法以目前的形式得到合理的回答。如需帮助澄清此问题以便重新打开,visit the help center . 关闭 1
有没有办法强制将另一个 窗口置于顶部? 不是应用程序的窗口,而是另一个已经在系统上运行的窗口。 (Windows, C/C++/C#) 最佳答案 SetWindowPos(that_window_ha
假设您可以在 C/C++ 或 Csharp 之间做出选择,并且您打算在 Windows 和 Linux 服务器上运行同一服务器的多个实例,那么构建套接字服务器应用程序的最明智选择是什么? 最佳答案 如
你们能告诉我它们之间的区别吗? 顺便问一下,有什么叫C++库或C库的吗? 最佳答案 C++ 标准库 和 C 标准库 是 C++ 和 C 标准定义的库,提供给 C++ 和 C 程序使用。那是那些词的共同
下面的测试代码,我将输出信息放在注释中。我使用的是 gcc 4.8.5 和 Centos 7.2。 #include #include class C { public:
很难说出这里问的是什么。这个问题是含糊的、模糊的、不完整的、过于宽泛的或修辞性的,无法以目前的形式得到合理的回答。如需帮助澄清此问题以便重新打开它,visit the help center 。 已关
我的客户将使用名为 annoucement 的结构/类与客户通信。我想我会用 C++ 编写服务器。会有很多不同的类继承annoucement。我的问题是通过网络将这些类发送给客户端 我想也许我应该使用
我在 C# 中有以下函数: public Matrix ConcatDescriptors(IList> descriptors) { int cols = descriptors[0].Co
我有一个项目要编写一个函数来对某些数据执行某些操作。我可以用 C/C++ 编写代码,但我不想与雇主共享该函数的代码。相反,我只想让他有权在他自己的代码中调用该函数。是否可以?我想到了这两种方法 - 在
我使用的是编写糟糕的第 3 方 (C/C++) Api。我从托管代码(C++/CLI)中使用它。有时会出现“访问冲突错误”。这使整个应用程序崩溃。我知道我无法处理这些错误[如果指针访问非法内存位置等,
关闭。这个问题不符合Stack Overflow guidelines .它目前不接受答案。 我们不允许提问寻求书籍、工具、软件库等的推荐。您可以编辑问题,以便用事实和引用来回答。 关闭 7 年前。
已关闭。此问题不符合Stack Overflow guidelines 。目前不接受答案。 要求我们推荐或查找工具、库或最喜欢的场外资源的问题对于 Stack Overflow 来说是偏离主题的,因为
我有一些 C 代码,将使用 P/Invoke 从 C# 调用。我正在尝试为这个 C 函数定义一个 C# 等效项。 SomeData* DoSomething(); struct SomeData {
这个问题已经有答案了: Why are these constructs using pre and post-increment undefined behavior? (14 个回答) 已关闭 6
我是一名优秀的程序员,十分优秀!