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Obtaining advanced information about installed devices
[WinPcap tutorial: a step by step guide to using WinPcap]

Lesson 1 (Obtaining the device list) demonstrated how to get basic information (i.e. device name and description) about available adapters. Actually, WinPcap provides also other advanced information. In particular, every pcap_if structure returned by pcap_findalldevs_ex() contains also a list of pcap_addr structures, with:

Additionally, pcap_findalldevs_ex() can also return remote adapters and a list of pcap files that are located in a given local folder.

The following sample provides an ifprint() function that prints the complete contents of a pcap_if structure. It is invoked by the program for every entry returned by pcap_findalldevs_ex().

/*
 * 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


// 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;
}



00001 /*
00002  * Copyright (c) 1999 - 2003
00003  * NetGroup, Politecnico di Torino (Italy)
00004  * All rights reserved.
00005  * 
00006  * Redistribution and use in source and binary forms, with or without 
00007  * modification, are permitted provided that the following conditions 
00008  * are met:
00009  * 
00010  * 1. Redistributions of source code must retain the above copyright 
00011  * notice, this list of conditions and the following disclaimer.
00012  * 2. Redistributions in binary form must reproduce the above copyright 
00013  * notice, this list of conditions and the following disclaimer in the 
00014  * documentation and/or other materials provided with the distribution. 
00015  * 3. Neither the name of the Politecnico di Torino nor the names of its 
00016  * contributors may be used to endorse or promote products derived from 
00017  * this software without specific prior written permission. 
00018  * 
00019  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
00020  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
00021  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 
00022  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
00023  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
00024  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
00025  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 
00026  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 
00027  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
00028  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
00029  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00030  * 
00031  */
00032 
00033 
00034 #include "pcap.h"
00035 
00036 #ifndef WIN32
00037     #include <sys/socket.h>
00038     #include <netinet/in.h>
00039 #else
00040     #include <winsock.h>
00041 #endif
00042 
00043 
00044 // Function prototypes
00045 void ifprint(pcap_if_t *d);
00046 char *iptos(u_long in);
00047 char* ip6tos(struct sockaddr *sockaddr, char *address, int addrlen);
00048 
00049 
00050 int main()
00051 {
00052   pcap_if_t *alldevs;
00053   pcap_if_t *d;
00054   char errbuf[PCAP_ERRBUF_SIZE+1];
00055   char source[PCAP_ERRBUF_SIZE+1];
00056 
00057   printf("Enter the device you want to list:\n"
00058             "rpcap://              ==> lists interfaces in the local machine\n"
00059             "rpcap://hostname:port ==> lists interfaces in a remote machine\n"
00060             "                          (rpcapd daemon must be up and running\n"
00061             "                           and it must accept 'null' authentication)\n"
00062             "file://foldername     ==> lists all pcap files in the give folder\n\n"
00063             "Enter your choice: ");
00064 
00065   fgets(source, PCAP_ERRBUF_SIZE, stdin);
00066   source[PCAP_ERRBUF_SIZE] = '\0';
00067 
00068   /* Retrieve the interfaces list */
00069   if (pcap_findalldevs_ex(source, NULL, &alldevs, errbuf) == -1)
00070   {
00071     fprintf(stderr,"Error in pcap_findalldevs: %s\n",errbuf);
00072     exit(1);
00073   }
00074 
00075   /* Scan the list printing every entry */
00076   for(d=alldevs;d;d=d->next)
00077   {
00078     ifprint(d);
00079   }
00080 
00081   pcap_freealldevs(alldevs);
00082 
00083   return 1;
00084 }
00085 
00086 
00087 
00088 /* Print all the available information on the given interface */
00089 void ifprint(pcap_if_t *d)
00090 {
00091   pcap_addr_t *a;
00092   char ip6str[128];
00093 
00094   /* Name */
00095   printf("%s\n",d->name);
00096 
00097   /* Description */
00098   if (d->description)
00099     printf("\tDescription: %s\n",d->description);
00100 
00101   /* Loopback Address*/
00102   printf("\tLoopback: %s\n",(d->flags & PCAP_IF_LOOPBACK)?"yes":"no");
00103 
00104   /* IP addresses */
00105   for(a=d->addresses;a;a=a->next) {
00106     printf("\tAddress Family: #%d\n",a->addr->sa_family);
00107   
00108     switch(a->addr->sa_family)
00109     {
00110       case AF_INET:
00111         printf("\tAddress Family Name: AF_INET\n");
00112         if (a->addr)
00113           printf("\tAddress: %s\n",iptos(((struct sockaddr_in *)a->addr)->sin_addr.s_addr));
00114         if (a->netmask)
00115           printf("\tNetmask: %s\n",iptos(((struct sockaddr_in *)a->netmask)->sin_addr.s_addr));
00116         if (a->broadaddr)
00117           printf("\tBroadcast Address: %s\n",iptos(((struct sockaddr_in *)a->broadaddr)->sin_addr.s_addr));
00118         if (a->dstaddr)
00119           printf("\tDestination Address: %s\n",iptos(((struct sockaddr_in *)a->dstaddr)->sin_addr.s_addr));
00120         break;
00121 
00122       case AF_INET6:
00123         printf("\tAddress Family Name: AF_INET6\n");
00124         if (a->addr)
00125           printf("\tAddress: %s\n", ip6tos(a->addr, ip6str, sizeof(ip6str)));
00126        break;
00127 
00128       default:
00129         printf("\tAddress Family Name: Unknown\n");
00130         break;
00131     }
00132   }
00133   printf("\n");
00134 }
00135 
00136 
00137 
00138 /* From tcptraceroute, convert a numeric IP address to a string */
00139 #define IPTOSBUFFERS    12
00140 char *iptos(u_long in)
00141 {
00142     static char output[IPTOSBUFFERS][3*4+3+1];
00143     static short which;
00144     u_char *p;
00145 
00146     p = (u_char *)&in;
00147     which = (which + 1 == IPTOSBUFFERS ? 0 : which + 1);
00148     sprintf(output[which], "%d.%d.%d.%d", p[0], p[1], p[2], p[3]);
00149     return output[which];
00150 }
00151 
00152 char* ip6tos(struct sockaddr *sockaddr, char *address, int addrlen)
00153 {
00154     socklen_t sockaddrlen;
00155 
00156     #ifdef WIN32
00157     sockaddrlen = sizeof(struct sockaddr_in6);
00158     #else
00159     sockaddrlen = sizeof(struct sockaddr_storage);
00160     #endif
00161 
00162 
00163     if(getnameinfo(sockaddr, 
00164         sockaddrlen, 
00165         address, 
00166         addrlen, 
00167         NULL, 
00168         0, 
00169         NI_NUMERICHOST) != 0) address = NULL;
00170 
00171     return address;
00172 }
00173 
00174

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documentation. Copyright (c) 2002-2005 Politecnico di Torino. Copyright (c) 2005 CACE technologies. All rights reserved.