帮助劲犇同步更新pcap的例子

README

@@ -47,6 +47,10 @@ omp_threadpool
 	C++与OMP配合的最简线程池
 	https://goldenhawking.blog.csdn.net/article/details/51824243
 
+pcapio
+	UDP丢包替代：用PCAP实现C/C++以太网SDR吞吐
+	https://goldenhawking.blog.csdn.net/article/details/126292692
+
 primer_calc
 	C++ OpenMP有限资源快速连续素数求取
 	https://goldenhawking.blog.csdn.net/article/details/109043815

pcapio/main.cpp

 #include <iostream>
+#include <vector>
 #include "pcapio.h"
 #include <pcap.h>
 using namespace std;
 
 int main()
 {
-	std::map<std::string,std::string > devmap;
-	std::string errstring = PCAPIO::pcapio_interfaces(devmap);
-	for (auto & p : devmap)
-	{
-		cout <<p.second;
-		cout <<"\n";
-	}
+    std::map<std::string,std::string > devmap;
+    std::vector<std::string> names;
+    std::string errstring = PCAPIO::pcapio_interfaces(devmap);
+    if (errstring.size())
+    {
+        cout <<"Error:\n"<<errstring<<"\n";
+        return 0;
+    }
+    for (auto & p : devmap)
+    {
+        names.push_back(p.first);
+        cout <<"==========\n";
+        cout << "Device " << names.size() <<":\n";
+        cout <<p.second;
+    }
 
-	cout <<"Input device name:";
+    cout <<"Input src device id 1~"<<names.size()<<":";
+    unsigned int nID = 0;
+    cin >> nID;
+    if (!nID || nID > devmap.size())
+    {
+        cout <<"Invalid ID out of range\n";
+        return 0;
+    }
+    std::string strDev = names[nID-1];
 
-	std::string strDev;
-	cin >> strDev;
+    pcap_t *handle = NULL;
+    char errbuf[PCAP_ERRBUF_SIZE];
+    handle = pcap_open_live(strDev.c_str(), 65535, 1, 10, errbuf);
+    if(handle == NULL)
+    {
+        printf("pcap_open_live return err,errbuf:%s...\n", errbuf);
+        return -1;
+    }
+    struct bpf_program filter;
+    char filter_app[] = "ip";
+    bpf_u_int32 net = 0;
+    int ret32 = pcap_compile(handle, &filter, filter_app, 0, net);
+    if(ret32 < 0)
+    {
+        printf("pcap_compile return %d, errbuf:%s\n", ret32, errbuf);
+        return -1;
+    }
+    ret32 = pcap_setfilter(handle, &filter);
+    if(ret32 < 0)
+    {
+        printf("pcap_setfilter return %d, errbuf:%s\n", ret32, errbuf);
+        return -1;
+    }
 
-	pcap_t *handle = NULL;
-	char errbuf[PCAP_ERRBUF_SIZE];
-	handle = pcap_open_live(strDev.c_str(), 65535, 1, 10, errbuf);
-	if(handle == NULL)
-	{
-		printf("pcap_open_live return err,errbuf:%s...\n", errbuf);
-		return -1;
-	}
-	struct bpf_program filter;
-	char filter_app[] = "ip";
-	bpf_u_int32 net = 0;
-	int ret32 = pcap_compile(handle, &filter, filter_app, 0, net);
-	if(ret32 < 0)
-	{
-		printf("pcap_compile return %d, errbuf:%s\n", ret32, errbuf);
-		return -1;
-	}
-	ret32 = pcap_setfilter(handle, &filter);
-	if(ret32 < 0)
-	{
-		printf("pcap_setfilter return %d, errbuf:%s\n", ret32, errbuf);
-		return -1;
-	}
+    const u_char *packet;
+    struct pcap_pkthdr header;
+    //注意，要设置较大的缓存
+    pcap_set_buffer_size(handle,256*1024*1024);
 
-	const u_char *packet;
-	struct pcap_pkthdr header;
 
-	pcap_set_buffer_size(handle,128*1024*1024);
-
-
-	while (1)
-	{
-		packet = pcap_next(handle, &header);
-		if(packet)
-		{
-			printf("LEN=%d:", header.len);
-			for (int i=0;i<header.len;++i)
-			{
-				if ((i>=14 && i<32) || i+4 >= header.len)
-					printf ("%02X",packet[i]);
-				else if (i==32)
-					printf ("...");
-			}
-			printf ("\n");
-		}
-	}
-	pcap_close(handle);
-	return 0;
+    while (1)
+    {
+        packet = pcap_next(handle, &header);
+        if(packet)
+        {
+            printf("LEN=%d:", header.len);
+            for (unsigned int i=0;i<header.len;++i)
+            {
+                if ((i>=14 && i<32) || i+4 >= header.len)
+                    printf ("%02X",packet[i]);
+                else if (i==32)
+                    printf ("...");
+            }
+            printf ("\n");
+            //如果需要转发，则要打开另一个handle。
+            //pcap_sendpacket(handle_dst,packet,header.len);
+        }
+    }
+    pcap_close(handle);
+    return 0;
 }

pcapio/pcapio.cpp

@@ -2,102 +2,105 @@
 #include <pcap.h>
 #include <string.h>
 namespace PCAPIO{
-	std::string ifaddresses(pcap_if_t *d);
+    std::string ifaddresses(pcap_if_t *d);
 
-	std::string pcapio_interfaces(std::map<std::string,std::string> & devmap)
-	{
-		std::string res;
-		pcap_if_t *alldevs;
-		int count = 0;
-		char errbuf[PCAP_ERRBUF_SIZE];
-		if(pcap_findalldevs(&alldevs, errbuf) == -1){
-			res = errbuf;
-			return res;
-		}
-		for(auto d = alldevs; d != NULL; d = d->next){
-			std::string d_name = d->name;
-			std::string d_des = ifaddresses(d);
-			devmap[d_name] = d_des;
-		}
+    std::string pcapio_interfaces(std::map<std::string,std::string> & devmap)
+    {
+        std::string res;
+        pcap_if_t *alldevs;
+        char errbuf[PCAP_ERRBUF_SIZE];
+        if(pcap_findalldevs(&alldevs, errbuf) == -1){
+            res = errbuf;
+            return res;
+        }
+        for(auto d = alldevs; d != NULL; d = d->next){
+            std::string d_name = d->name;
+            std::string d_des = ifaddresses(d);
+            devmap[d_name] = d_des;
+        }
 
-		pcap_freealldevs(alldevs);
-		return res;
-	}
-	std::string address_print(unsigned char * v)
-	{
-		std::string res;
-		char buf[1024];
-		int lbegin = 0, rbegin = 13;
-		while (!v[lbegin] )
-		{
-			++lbegin;
-			if (lbegin >=rbegin)
-				break;
-		}
-		while (!v[rbegin] )
-		{
-			--rbegin;
-			if (lbegin >=rbegin)
-				break;
-		}
-		res += "HEX(";
-		for (int i =lbegin; i<=rbegin;++i)
-		{
-			snprintf(buf,1024,"%02X", (unsigned int)v[i]);
-			res += buf;
-		}
-		res += ")";
-		res += "DEC(";
-		for (int i =lbegin; i<=rbegin;++i)
-		{
-			if (i>lbegin)
-				res += ".";
-			snprintf(buf,1024,"%u", (unsigned int)v[i] );
-			res += buf;
-		}
-		res += ")";
+        pcap_freealldevs(alldevs);
+        return res;
+    }
+    std::string address_print(unsigned char * v)
+    {
+        std::string res;
+        char buf[1024];
+        int lbegin = 0, rbegin = 13;
+        while (!v[lbegin] )
+        {
+            ++lbegin;
+            if (lbegin >=rbegin)
+                break;
+        }
+        while (!v[rbegin] )
+        {
+            --rbegin;
+            if (lbegin >=rbegin)
+                break;
+        }
+        res += "HEX(";
+        for (int i =lbegin; i<=rbegin;++i)
+        {
+            if (i>lbegin)
+                res += ":";
+            snprintf(buf,1024,"%02X", (unsigned int)v[i]);
+            res += buf;
+        }
+        res += ")";
+        res += "DEC(";
+        for (int i =lbegin; i<=rbegin;++i)
+        {
+            if (i>lbegin)
+                res += ".";
+            snprintf(buf,1024,"%u", (unsigned int)v[i] );
+            res += buf;
+        }
+        res += ")";
 
-		return res;
-	}
-	/* Print all the available information on the given interface */
-	std::string ifaddresses(pcap_if_t *d)
-	{
-		char buf[1024];
-		pcap_addr_t *a;
-		std::string res = d->name;
-		res += "\n";
-		if(d->description)
-		{
-			res += d->description;
-			res += "\n";
-		}
+        return res;
+    }
+    /* Print all the available information on the given interface */
+    std::string ifaddresses(pcap_if_t *d)
+    {
+        char buf[1024];
+        pcap_addr_t *a;
+        std::string res = "NAME=";
+        res+=d->name;
+        res += "\n";
+        if(d->description)
+        {
+            res += "Description=";
+            res += d->description;
+            res += "\n";
+        }
 
-		for(a=d->addresses;a;a=a->next) {
-			snprintf(buf,1024,"\tAF_0x%02X:",(unsigned int)a->addr->sa_family);
-			res += buf;
-			if (a->addr)
-			{
-				snprintf(buf,1024,"\n\t\tAddr:%s ",address_print((unsigned char *)a->addr->sa_data).c_str());
-				res += buf;
-			}
-			if (a->netmask)
-			{
-				snprintf(buf,1024,"\n\t\tMask:%s ",address_print((unsigned char *)a->addr->sa_data).c_str());
-				res += buf;
-			}
-			if (a->broadaddr)
-			{
-				snprintf(buf,1024,"\n\t\tCast:%s ",address_print((unsigned char *)a->addr->sa_data).c_str());
-				res += buf;
-			}
-			if (a->dstaddr)
-			{
-				snprintf(buf,1024,"\n\t\tDest:%s ",address_print((unsigned char *)a->addr->sa_data).c_str());
-				res += buf;
-			}
-			res += "\n";
-		}
-		return res;
-	}
+        for(a=d->addresses;a;a=a->next) {
+            snprintf(buf,1024,"  AF_0x%02X:",(unsigned int)a->addr->sa_family);
+            res += buf;
+            if (a->addr)
+            {
+                snprintf(buf,1024,"\n    Addr:%s ",address_print((unsigned char *)a->addr->sa_data).c_str());
+                res += buf;
+            }
+            if (a->netmask)
+            {
+                snprintf(buf,1024,"\n    Mask:%s ",address_print((unsigned char *)a->addr->sa_data).c_str());
+                res += buf;
+            }
+            if (a->broadaddr)
+            {
+                snprintf(buf,1024,"\n    Cast:%s ",address_print((unsigned char *)a->addr->sa_data).c_str());
+                res += buf;
+            }
+            if (a->dstaddr)
+            {
+                snprintf(buf,1024,"\n    Dest:%s ",address_print((unsigned char *)a->addr->sa_data).c_str());
+                res += buf;
+            }
+            res += "\n";
+        }
+        return res;
+    }
 }