WinPcap基础知识（第二课：获得已安装设备的高级信息）

第一课 (Obtaining the device list ) 展示了如何获得有用适配器的基本信息（如设备名称和描述）。事实上，WinPcap也提供另外的高级信息。特别的，每个pcap_findalldevs() 返回的 pcap_if 结构也包含了一个pcap_addr结构的列表：

 

• 该接口的地址列表a list of addresses for that interface.

   

• 网络掩码的列表a list of netmasks (each of which corresponds to an entry in the addresses list).

   

• 广播地址的列表a list of broadcast addresses (each of which corresponds to an entry in the addresses list).

   

• 目标地址的列表a list of destination addresses (each of which corresponds to an entry in the addresses list).

   

如下的例子提供一个ifpriont（）函数，来打印pcap_if结构的完整内容。它被pcap_findalldevs()返回的每个条目调用。

 

  /* * Copyright (c) 1999 - 2003 * NetGroup, Politecnico di Torino (Italy) * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the Politecnico di Torino nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * */ #include <pcap.h> #ifndef WIN32 #include <sys/socket.h> #include <netinet/in.h> #else #include <winsock.h> #endif #pragma comment(lib,"ws2_32.lib") // Function prototypes void ifprint(pcap_if_t *d); char *iptos(u_long in); char* ip6tos(struct sockaddr *sockaddr, char *address, int addrlen); int main() { pcap_if_t *alldevs; pcap_if_t *d; char errbuf[PCAP_ERRBUF_SIZE+1]; char source[PCAP_ERRBUF_SIZE+1]; printf("Enter the device you want to list:/n" "rpcap:// ==> lists interfaces in the local machine/n" "rpcap://hostname:port ==> lists interfaces in a remote machine/n" " (rpcapd daemon must be up and running/n" " and it must accept 'null' authentication)/n" "file://foldername ==> lists all pcap files in the give folder/n/n" "Enter your choice: "); fgets(source, PCAP_ERRBUF_SIZE, stdin); source[PCAP_ERRBUF_SIZE] = '/0'; /* Retrieve the interfaces list */ if (pcap_findalldevs_ex(source, NULL, &alldevs, errbuf) == -1) { fprintf(stderr,"Error in pcap_findalldevs: %s/n",errbuf); exit(1); } /* Scan the list printing every entry */ for(d=alldevs;d;d=d->next) { ifprint(d); } pcap_freealldevs(alldevs); return 1; } /* Print all the available information on the given interface */ void ifprint(pcap_if_t *d) { pcap_addr_t *a; char ip6str[128]; /* Name */ printf("%s/n",d->name); /* Description */ if (d->description) printf("/tDescription: %s/n",d->description); /* Loopback Address*/ printf("/tLoopback: %s/n",(d->flags & PCAP_IF_LOOPBACK)?"yes":"no"); /* IP addresses */ for(a=d->addresses;a;a=a->next) { printf("/tAddress Family: #%d/n",a->addr->sa_family); switch(a->addr->sa_family) { case AF_INET: printf("/tAddress Family Name: AF_INET/n"); if (a->addr) printf("/tAddress: %s/n",iptos(((struct sockaddr_in *)a->addr)->sin_addr.s_addr)); if (a->netmask) printf("/tNetmask: %s/n",iptos(((struct sockaddr_in *)a->netmask)->sin_addr.s_addr)); if (a->broadaddr) printf("/tBroadcast Address: %s/n",iptos(((struct sockaddr_in *)a->broadaddr)->sin_addr.s_addr)); if (a->dstaddr) printf("/tDestination Address: %s/n",iptos(((struct sockaddr_in *)a->dstaddr)->sin_addr.s_addr)); break; case AF_INET6: printf("/tAddress Family Name: AF_INET6/n"); if (a->addr) printf("/tAddress: %s/n", ip6tos(a->addr, ip6str, sizeof(ip6str))); break; default: printf("/tAddress Family Name: Unknown/n"); break; } } printf("/n"); } /* From tcptraceroute, convert a numeric IP address to a string */ #define IPTOSBUFFERS 12 char *iptos(u_long in) { static char output[IPTOSBUFFERS][3*4+3+1]; static short which; u_char *p; p = (u_char *)&in; which = (which + 1 == IPTOSBUFFERS ? 0 : which + 1); sprintf(output[which], "%d.%d.%d.%d", p[0], p[1], p[2], p[3]); return output[which]; } char* ip6tos(struct sockaddr *sockaddr, char *address, int addrlen) { socklen_t sockaddrlen; #ifdef WIN32 sockaddrlen = sizeof(struct sockaddr_in6); #else sockaddrlen = sizeof(struct sockaddr_storage); #endif if(getnameinfo(sockaddr, sockaddrlen, address, addrlen, NULL, 0, NI_NUMERICHOST) != 0) address = NULL; return address; }

 

 说明：该成员用到getnameinfo()和里面的NI_NUMERICHOST 宏，这些在"WS2tcpip.h" 头文件里面有定义，所以要包含这个头文件（官方网站上面下载的文档里面的pack里面是没有包含这个头文件的，那样编译会出错（vs6）。但是在vs7里面编译没有任何问题。估计是在其它文件里面已经把该头文件包含进去了。

 

此程序的缺点很明显：显示本机没有问题，但是显示远程主机就一般都不行，它要求双方都要装winpcap包并且对方在后台要运行rpcap，并且接收参数NULL授权参数。笔者试了一下，几乎不能获得远程主机的接口列表。

 

转自：http://wotseb.bokee.com/1419033.html