void send_icmp_timestamp(void)
{
char *packet;
struct myicmphdr *icmp;
struct icmp_tstamp_data *tstamp_data;
packet = malloc(ICMPHDR_SIZE + sizeof(struct icmp_tstamp_data));
if (packet == NULL) {
perror("[send_icmp] malloc");
return;
}
memset(packet, 0, ICMPHDR_SIZE + sizeof(struct icmp_tstamp_data));
icmp = (struct myicmphdr*) packet;
tstamp_data = (struct icmp_tstamp_data*) (packet + ICMPHDR_SIZE);
/* fill icmp hdr */
icmp->type = opt_icmptype; /* echo replay or echo request */
icmp->code = 0;
icmp->checksum = 0;
icmp->un.echo.id = getpid() & 0xffff;
icmp->un.echo.sequence = _icmp_seq;
tstamp_data->orig = htonl(get_midnight_ut_ms());
tstamp_data->recv = tstamp_data->tran = 0;
/* icmp checksum */
if (icmp_cksum == -1)
icmp->checksum = cksum((u_short*)packet, ICMPHDR_SIZE +
sizeof(struct icmp_tstamp_data));
else
icmp->checksum = icmp_cksum;
/* adds this pkt in delaytable */
if (opt_icmptype == ICMP_TIMESTAMP)
delaytable_add(_icmp_seq, 0, time(NULL), get_usec(), S_SENT);
/* send packet */
send_ip_handler(packet, ICMPHDR_SIZE + sizeof(struct icmp_tstamp_data));
free (packet);
_icmp_seq++;
}
/* -------------------------------- input ---------------------------------- */
static void receiver(struct portinfo *pi, int childpid)
{
struct myiphdr ip;
char packet[IP_MAX_SIZE+linkhdr_size];
while(1)
{
int len, iplen;
len = read_packet(packet, IP_MAX_SIZE+linkhdr_size);
if (len == -1) {
perror("read_packet");
continue;
}
/* minimal sanity checks */
if (len < linkhdr_size)
continue;
iplen = len - linkhdr_size;
if (iplen < sizeof(struct myiphdr))
continue;
/* copy the ip header in an access-safe place */
memcpy(&ip, packet+linkhdr_size, sizeof(ip));
/* check if the dest IP matches */
if (memcmp(&ip.daddr, &local.sin_addr, sizeof(ip.daddr)))
continue;
/* check if the source IP matches */
if (ip.protocol != IPPROTO_ICMP &&
memcmp(&ip.saddr, &remote.sin_addr, sizeof(ip.saddr)))
continue;
if (ip.protocol == IPPROTO_TCP) {
struct mytcphdr tcp;
int iphdrlen = ip.ihl << 2;
char flags[16];
time_t rttms;
int sport;
/* more sanity checks */
if ((iplen - iphdrlen) < sizeof(tcp))
continue;
/* time to copy the TCP header in a safe place */
memcpy(&tcp, packet+linkhdr_size+iphdrlen, sizeof(tcp));
/* check if the TCP dest port matches */
#if 0
printf("SRC: %d DST: %d\n",
ntohs(tcp.th_sport),
ntohs(tcp.th_dport));
#endif
if (ntohs(tcp.th_dport) != initsport)
continue;
sport = htons(tcp.th_sport);
if (pi[sport].active == 0)
continue;
/* Note that we don't care about a wrote RTT
* result due to resend on the same port. */
rttms = get_midnight_ut_ms() - pi[sport].sentms;
avrgcount++;
avrgms = (avrgms*(avrgcount-1)/avrgcount)+(rttms/avrgcount);
/* The avrg RTT is shared using shared memory,
* no locking... */
pi[MAXPORT+1].active = (int) avrgms;
tcp_strflags(flags, tcp.th_flags);
#if 0
printf("%5d: %s %3d %5d %5d %10ld (%2d)\n",
sport,
flags,
ip.ttl,
ip.id,
ntohs(tcp.th_win),
(long) rttms,
opt_scan_probes-(pi[sport].retry));
#endif
if ((tcp.th_flags & TH_SYN) || opt_verbose) {
printf("%5d %-11.11s: %s %3d %5d %5d %5d\n",
sport,
port_to_name(sport),
flags,
ip.ttl,
ip.id,
ntohs(tcp.th_win),
iplen);
fflush(stdout);
}
pi[sport].active = 0;
} else if (ip.protocol == IPPROTO_ICMP) {
struct myicmphdr icmp;
struct myiphdr subip;
struct mytcphdr subtcp;
int iphdrlen = ip.ihl << 2;
unsigned char *p;
int port;
struct in_addr gwaddr;
/* more sanity checks, we are only interested
* in ICMP quoting the original packet. */
if ((iplen - iphdrlen) < sizeof(icmp)+sizeof(subip)+sizeof(subtcp))
continue;
/* time to copy headers in a safe place */
p = (unsigned char *) packet+linkhdr_size+iphdrlen;
//memcpy(&icmp, p, sizeof(subtcp)); //FIXME memcpy will always overflow destination buffer
memmove(&icmp, p, sizeof(&icmp));
p += sizeof(icmp);
memcpy(&subip, p, sizeof(ip));
p += sizeof(ip);
memcpy(&subtcp, p, sizeof(subtcp));
/* Check if the ICMP quoted packet matches */
/* check if the source IP matches */
if (memcmp(&subip.saddr, &local.sin_addr, sizeof(subip.saddr)))
continue;
/* check if the destination IP matches */
if (memcmp(&subip.daddr, &remote.sin_addr, sizeof(subip.daddr)))
continue;
/* check if the quoted TCP packet port matches */
if (ntohs(subtcp.th_sport) != initsport)
continue;
port = htons(subtcp.th_dport);
if (pi[port].active == 0)
continue;
pi[port].active = 0;
memcpy(&gwaddr.s_addr, &ip.saddr, 4);
printf("%5d: %3d %5d %5d (ICMP %3d %3d from %s)\n",
port,
ip.ttl,
iplen,
ntohs(ip.id),
icmp.type,
icmp.code,
inet_ntoa(gwaddr));
}
}
}
/* -------------------------------- output ---------------------------------- */
static void sender(struct portinfo *pi)
{
int i, retry = 0;
time_t start_time;
start_time = get_midnight_ut_ms();
while(1) {
int active = 0;
int recvd = 0;
retry ++;
for (i = 0; i < MAXPORT; i++) {
if (pi[i].active && pi[i].retry) {
active++;
pi[i].retry--;
sequence = -1;
dst_port = i;
pi[i].sentms = get_midnight_ut_ms();
send_tcp();
if (opt_waitinusec) {
if (usec_delay.it_interval.tv_usec)
usleep(usec_delay.it_interval.tv_usec);
} else {
sleep(sending_wait);
}
}
}
avrgms = (float) pi[MAXPORT+1].active;
if (retry >= 3) {
if (opt_debug)
printf("AVRGMS %f\n", avrgms);
if (avrgms)
usleep((int) (avrgms*1000));
else
sleep(1);
}
for (i = 0; i < MAXPORT; i++) {
if (!pi[i].active && pi[i].retry)
recvd++;
}
/* More to scan? */
if (!active) {
if (!recvd)
sleep(1);
fprintf(stderr, "All replies received. Done.\n");
printf("Not responding ports: ");
for (i = 0; i < MAXPORT; i++) {
if (pi[i].active && !pi[i].retry)
printf("(%d %.11s) ", i, port_to_name(i));
}
printf("\n");
exit(0);
}
/* Are we sending too fast? */
if ((!recvd && opt_waitinusec &&
usec_delay.it_interval.tv_usec == 0 &&
(get_midnight_ut_ms() - start_time) > 500) ||
(opt_scan_probes-retry) <= 2)
{
if (opt_debug)
printf("SLOWING DONW\n");
usec_delay.it_interval.tv_usec *= 10;
usec_delay.it_interval.tv_usec ++;
}
}
}
