学步园

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。

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

 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