1#ifdef HAVE_CONFIG_H
2#include "config.h"
3#endif
4
5#include <stdlib.h>
6#include <sys/types.h>
7#include <sys/socket.h>
8#include <netinet/in.h>
9#include <arpa/inet.h>
10#include <netdb.h>
11
12#include <pcap.h>
13
14static void ifprint(pcap_if_t *d);
15static char *iptos(bpf_u_int32 in);
16
17int main(int argc, char **argv)
18{
19  pcap_if_t *alldevs;
20  pcap_if_t *d;
21  char *s;
22  bpf_u_int32 net, mask;
23
24  char errbuf[PCAP_ERRBUF_SIZE+1];
25  if (pcap_findalldevs(&alldevs, errbuf) == -1)
26  {
27    fprintf(stderr,"Error in pcap_findalldevs: %s\n",errbuf);
28    exit(1);
29  }
30  for(d=alldevs;d;d=d->next)
31  {
32    ifprint(d);
33  }
34
35  if ( (s = pcap_lookupdev(errbuf)) == NULL)
36  {
37    fprintf(stderr,"Error in pcap_lookupdev: %s\n",errbuf);
38  }
39  else
40  {
41    printf("Preferred device name: %s\n",s);
42  }
43
44  if (pcap_lookupnet(s, &net, &mask, errbuf) < 0)
45  {
46    fprintf(stderr,"Error in pcap_lookupnet: %s\n",errbuf);
47  }
48  else
49  {
50    printf("Preferred device is on network: %s/%s\n",iptos(net), iptos(mask));
51  }
52
53  exit(0);
54}
55
56static void ifprint(pcap_if_t *d)
57{
58  pcap_addr_t *a;
59#ifdef INET6
60  char ntop_buf[INET6_ADDRSTRLEN];
61#endif
62
63  printf("%s\n",d->name);
64  if (d->description)
65    printf("\tDescription: %s\n",d->description);
66  printf("\tLoopback: %s\n",(d->flags & PCAP_IF_LOOPBACK)?"yes":"no");
67
68  for(a=d->addresses;a;a=a->next) {
69    switch(a->addr->sa_family)
70    {
71      case AF_INET:
72        printf("\tAddress Family: AF_INET\n");
73        if (a->addr)
74          printf("\t\tAddress: %s\n",
75            inet_ntoa(((struct sockaddr_in *)(a->addr))->sin_addr));
76        if (a->netmask)
77          printf("\t\tNetmask: %s\n",
78            inet_ntoa(((struct sockaddr_in *)(a->netmask))->sin_addr));
79        if (a->broadaddr)
80          printf("\t\tBroadcast Address: %s\n",
81            inet_ntoa(((struct sockaddr_in *)(a->broadaddr))->sin_addr));
82        if (a->dstaddr)
83          printf("\t\tDestination Address: %s\n",
84            inet_ntoa(((struct sockaddr_in *)(a->dstaddr))->sin_addr));
85        break;
86#ifdef INET6
87      case AF_INET6:
88        printf("\tAddress Family: AF_INET6\n");
89        if (a->addr)
90          printf("\t\tAddress: %s\n",
91            inet_ntop(AF_INET6,
92               ((struct sockaddr_in6 *)(a->addr))->sin6_addr.s6_addr,
93               ntop_buf, sizeof ntop_buf));
94        if (a->netmask)
95          printf("\t\tNetmask: %s\n",
96            inet_ntop(AF_INET6,
97              ((struct sockaddr_in6 *)(a->netmask))->sin6_addr.s6_addr,
98               ntop_buf, sizeof ntop_buf));
99        if (a->broadaddr)
100          printf("\t\tBroadcast Address: %s\n",
101            inet_ntop(AF_INET6,
102              ((struct sockaddr_in6 *)(a->broadaddr))->sin6_addr.s6_addr,
103               ntop_buf, sizeof ntop_buf));
104        if (a->dstaddr)
105          printf("\t\tDestination Address: %s\n",
106            inet_ntop(AF_INET6,
107              ((struct sockaddr_in6 *)(a->dstaddr))->sin6_addr.s6_addr,
108               ntop_buf, sizeof ntop_buf));
109        break;
110#endif
111      default:
112        printf("\tAddress Family: Unknown (%d)\n", a->addr->sa_family);
113        break;
114    }
115  }
116  printf("\n");
117}
118
119/* From tcptraceroute */
120#define IPTOSBUFFERS	12
121static char *iptos(bpf_u_int32 in)
122{
123	static char output[IPTOSBUFFERS][3*4+3+1];
124	static short which;
125	u_char *p;
126
127	p = (u_char *)&in;
128	which = (which + 1 == IPTOSBUFFERS ? 0 : which + 1);
129	sprintf(output[which], "%d.%d.%d.%d", p[0], p[1], p[2], p[3]);
130	return output[which];
131}
132