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--- ./dnsspoof.c.orig 2001-03-15 09:33:03.000000000 +0100
+++ ./dnsspoof.c 2014-07-22 13:20:14.000000000 +0200
@@ -38,7 +38,7 @@
pcap_t *pcap_pd = NULL;
int pcap_off = -1;
-int lnet_sock = -1;
+libnet_t *l;
u_long lnet_ip = -1;
static void
@@ -90,19 +90,18 @@
dns_init(char *dev, char *filename)
{
FILE *f;
- struct libnet_link_int *llif;
+ libnet_t *l;
+ char libnet_ebuf[LIBNET_ERRBUF_SIZE];
struct dnsent *de;
char *ip, *name, buf[1024];
- if ((llif = libnet_open_link_interface(dev, buf)) == NULL)
- errx(1, "%s", buf);
+ if ((l = libnet_init(LIBNET_LINK, dev, libnet_ebuf)) == NULL)
+ errx(1, "%s", libnet_ebuf);
- if ((lnet_ip = libnet_get_ipaddr(llif, dev, buf)) == -1)
- errx(1, "%s", buf);
+ if ((lnet_ip = libnet_get_ipaddr4(l)) == -1)
+ errx(1, "%s", libnet_geterror(l));
- lnet_ip = htonl(lnet_ip);
-
- libnet_close_link_interface(llif);
+ libnet_destroy(l);
SLIST_INIT(&dns_entries);
@@ -180,7 +179,7 @@
static void
dns_spoof(u_char *u, const struct pcap_pkthdr *pkthdr, const u_char *pkt)
{
- struct libnet_ip_hdr *ip;
+ struct libnet_ipv4_hdr *ip;
struct libnet_udp_hdr *udp;
HEADER *dns;
char name[MAXHOSTNAMELEN];
@@ -189,7 +188,7 @@
in_addr_t dst;
u_short type, class;
- ip = (struct libnet_ip_hdr *)(pkt + pcap_off);
+ ip = (struct libnet_ipv4_hdr *)(pkt + pcap_off);
udp = (struct libnet_udp_hdr *)(pkt + pcap_off + (ip->ip_hl * 4));
dns = (HEADER *)(udp + 1);
p = (u_char *)(dns + 1);
@@ -212,7 +211,7 @@
if (class != C_IN)
return;
- p = buf + IP_H + UDP_H + dnslen;
+ p = buf + dnslen;
if (type == T_A) {
if ((dst = dns_lookup_a(name)) == -1)
@@ -234,38 +233,38 @@
anslen += 12;
}
else return;
-
- libnet_build_ip(UDP_H + dnslen + anslen, 0, libnet_get_prand(PRu16),
- 0, 64, IPPROTO_UDP, ip->ip_dst.s_addr,
- ip->ip_src.s_addr, NULL, 0, buf);
-
- libnet_build_udp(ntohs(udp->uh_dport), ntohs(udp->uh_sport),
- NULL, dnslen + anslen, buf + IP_H);
- memcpy(buf + IP_H + UDP_H, (u_char *)dns, dnslen);
+ memcpy(buf, (u_char *)dns, dnslen);
- dns = (HEADER *)(buf + IP_H + UDP_H);
+ dns = (HEADER *)buf;
dns->qr = dns->ra = 1;
if (type == T_PTR) dns->aa = 1;
dns->ancount = htons(1);
dnslen += anslen;
+
+ libnet_clear_packet(l);
+ libnet_build_udp(ntohs(udp->uh_dport), ntohs(udp->uh_sport),
+ LIBNET_UDP_H + dnslen, 0,
+ (u_int8_t *)buf, dnslen, l, 0);
+
+ libnet_build_ipv4(LIBNET_IPV4_H + LIBNET_UDP_H + dnslen, 0,
+ libnet_get_prand(LIBNET_PRu16), 0, 64, IPPROTO_UDP, 0,
+ ip->ip_dst.s_addr, ip->ip_src.s_addr, NULL, 0, l, 0);
- libnet_do_checksum(buf, IPPROTO_UDP, UDP_H + dnslen);
-
- if (libnet_write_ip(lnet_sock, buf, IP_H + UDP_H + dnslen) < 0)
+ if (libnet_write(l) < 0)
warn("write");
fprintf(stderr, "%s.%d > %s.%d: %d+ %s? %s\n",
- libnet_host_lookup(ip->ip_src.s_addr, 0), ntohs(udp->uh_sport),
- libnet_host_lookup(ip->ip_dst.s_addr, 0), ntohs(udp->uh_dport),
+ libnet_addr2name4(ip->ip_src.s_addr, 0), ntohs(udp->uh_sport),
+ libnet_addr2name4(ip->ip_dst.s_addr, 0), ntohs(udp->uh_dport),
ntohs(dns->id), type == T_A ? "A" : "PTR", name);
}
static void
cleanup(int sig)
{
- libnet_close_raw_sock(lnet_sock);
+ libnet_destroy(l);
pcap_close(pcap_pd);
exit(0);
}
@@ -276,6 +275,7 @@
extern char *optarg;
extern int optind;
char *p, *dev, *hosts, buf[1024];
+ char ebuf[LIBNET_ERRBUF_SIZE];
int i;
dev = hosts = NULL;
@@ -306,7 +306,7 @@
strlcpy(buf, p, sizeof(buf));
}
else snprintf(buf, sizeof(buf), "udp dst port 53 and not src %s",
- libnet_host_lookup(lnet_ip, 0));
+ libnet_addr2name4(lnet_ip, LIBNET_DONT_RESOLVE));
if ((pcap_pd = pcap_init(dev, buf, 128)) == NULL)
errx(1, "couldn't initialize sniffing");
@@ -314,10 +314,10 @@
if ((pcap_off = pcap_dloff(pcap_pd)) < 0)
errx(1, "couldn't determine link layer offset");
- if ((lnet_sock = libnet_open_raw_sock(IPPROTO_RAW)) == -1)
+ if ((l = libnet_init(LIBNET_RAW4, dev, ebuf)) == NULL)
errx(1, "couldn't initialize sending");
- libnet_seed_prand();
+ libnet_seed_prand(l);
signal(SIGHUP, cleanup);
signal(SIGINT, cleanup);
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