1 #include <u.h>
2 #include <sys/socket.h>
3 #include <net/if.h>
4 #include <netpacket/packet.h>
5 #include <net/ethernet.h>
6 #include <netinet/in.h>
7 #include <sys/ioctl.h>
8 #include <libc.h>
9 #include <ip.h>
10 #include <bio.h>
11 #include <fcall.h>
12 #include <libsec.h>
13 #include "dat.h"
14 #include "protos.h"
15 #include "y.tab.h"
16 
17 int
18 opendevice(char *dev, int promisc)
19 {
20 	int fd;
21 	struct ifreq ifr;
22 	struct sockaddr_ll sa;
23 
24 	if((fd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL))) < 0)
25 		return -1;
26 
27 	if(dev){
28 		memset(&ifr, 0, sizeof ifr);
29 		strncpy(ifr.ifr_name, dev, sizeof ifr.ifr_name);
30 		if(ioctl(fd, SIOCGIFINDEX, &ifr) < 0){
31 			close(fd);
32 			return -1;
33 		}
34 		memset(&sa, 0, sizeof sa);
35 		sa.sll_family = AF_PACKET;
36 		sa.sll_protocol = htons(ETH_P_ALL);
37 		sa.sll_ifindex = ifr.ifr_ifindex;
38 		if(bind(fd, (struct sockaddr*)&sa, sizeof sa) < 0){
39 			close(fd);
40 			return -1;
41 		}
42 	}
43 
44 	if(promisc){
45 		memset(&ifr, 0, sizeof ifr);
46 		strncpy(ifr.ifr_name, dev, sizeof ifr.ifr_name);
47 		if(ioctl(fd, SIOCGIFFLAGS, &ifr) < 0){
48 			close(fd);
49 			return -1;
50 		}
51 		ifr.ifr_flags |= IFF_PROMISC;
52 		if(ioctl(fd, SIOCSIFFLAGS, &ifr) < 0){
53 			close(fd);
54 			return -1;
55 		}
56 	}
57 	return fd;
58 }