int gre_encapsulate(ip_t *honeyd_ip, struct addr *src, struct addr *dst,
struct ip_hdr *iip, u_int iiplen)
{
struct ip_hdr *oip = (struct ip_hdr *) pkt;
struct gre_hdr *gre = (struct gre_hdr *) (oip + 1);
u_char *data = (u_char *) (gre + 1);
u_int iplen, sum;
iplen = sizeof(struct ip_hdr) + sizeof(struct gre_hdr) + iiplen;
if (iplen > sizeof(pkt))
{
syslog(LOG_ERR, "%s: packet too long: %d", __func__, iplen);
return (-1);
}
ip_pack_hdr(pkt, 0, iplen, rand_uint16(honeyd_rand), 0, honeyd_ttl,
IP_PROTO_GRE, src->addr_ip, dst->addr_ip);
memset(gre, 0, sizeof(struct gre_hdr));
gre->gre_flags = htons(GRE_CHECKSUM | GRE_VERSION);
gre->gre_proto = htons(GRE_IP4PROTO);
/* Copy the payload */
memcpy(data, iip, iiplen);
/* Calculate the checksum */
sum = ip_cksum_add(gre, iiplen + sizeof(struct gre_hdr), 0);
gre->gre_sum = ip_cksum_carry(sum);
ip_checksum(oip, iplen);
return (ip_send(honeyd_ip, pkt, iplen) != iplen ? -1 : 0);
}
int
main(int argc, char *argv[])
{
struct intf_entry ifent;
intf_t *intf;
int i, tests;
char *cmd;
if (argc < 3)
usage();
for (tests = 0, i = 1; i < argc - 1; i++) {
cmd = argv[i];
if (strcmp(cmd, "all") == 0)
tests = ~0;
else if (strcmp(cmd, "ping") == 0)
tests |= TEST_PING;
else if (strcmp(cmd, "ip-opt") == 0)
tests |= TEST_IP_OPT;
else if (strcmp(cmd, "ip-tracert") == 0)
tests |= TEST_IP_TRACERT;
else if (strcmp(cmd, "frag") == 0)
tests |= TEST_FRAG;
else if (strcmp(cmd, "frag-new") == 0)
tests |= TEST_FRAG_NEW;
else if (strcmp(cmd, "frag-old") == 0)
tests |= TEST_FRAG_OLD;
else if (strcmp(cmd, "frag-timeout") == 0)
tests |= TEST_FRAG_TIMEOUT;
else
usage();
}
if (addr_aton(argv[i], &ctx.dst) < 0)
err(1, "invalid host %s", argv[i]);
if ((intf = intf_open()) == NULL)
err(1, "couldn't open interface handle");
ifent.intf_len = sizeof(ifent);
if (intf_get_dst(intf, &ifent, &ctx.dst) < 0)
err(1, "couldn't find interface for %s", addr_ntoa(&ctx.dst));
memcpy(&ctx.src, &ifent.intf_addr, sizeof(ctx.src));
ctx.src.addr_bits = IP_ADDR_BITS;
intf_close(intf);
if ((ctx.ip = ip_open()) == NULL)
err(1, "couldn't open raw IP interface");
if ((ctx.pcap = pcap_open(ifent.intf_name)) == NULL)
err(1, "couldn't open %s for sniffing", ifent.intf_name);
if ((ctx.dloff = pcap_dloff(ctx.pcap)) < 0)
err(1, "couldn't determine link layer offset");
ctx.rnd = rand_open();
pkt_init(16);
TAILQ_INIT(&ctx.pktq);
ping = pkt_new();
ip_pack_hdr(ping->pkt_ip, 0, IP_HDR_LEN + 8 + 24, 666, 0,
IP_TTL_DEFAULT, IP_PROTO_ICMP, ctx.src.addr_ip, ctx.dst.addr_ip);
icmp_pack_hdr_echo(ping->pkt_icmp, ICMP_ECHO, ICMP_CODE_NONE,
666, 1, "AAAAAAAABBBBBBBBCCCCCCCC", 24);
ping->pkt_end = ping->pkt_eth_data + IP_HDR_LEN + 8 + 24;
pkt_decorate(ping);
if ((tests & TEST_PING) != 0)
test_ping();
if ((tests & TEST_IP_OPT) != 0)
test_ip_opt();
if ((tests & TEST_IP_TRACERT) != 0)
test_ip_tracert();
if ((tests & TEST_FRAG) != 0)
test_frag(NULL, 0);
if ((tests & TEST_FRAG_NEW) != 0)
test_frag("new", 0);
if ((tests & TEST_FRAG_OLD) != 0)
test_frag("old", 0);
if ((tests & TEST_FRAG_TIMEOUT) != 0)
test_frag(NULL, 1);
rand_close(ctx.rnd);
pcap_close(ctx.pcap);
ip_close(ctx.ip);
exit(0);
}