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-rw-r--r--networking/pscan.c8
1 files changed, 3 insertions, 5 deletions
diff --git a/networking/pscan.c b/networking/pscan.c
index 9fa6993e8..fe146b8bd 100644
--- a/networking/pscan.c
+++ b/networking/pscan.c
@@ -35,13 +35,13 @@ int pscan_main(int argc, char **argv)
{
const char *opt_max_port = "1024"; /* -P: default max port */
const char *opt_min_port = "1"; /* -p: default min port */
- const char *opt_timeout = "5000"; /* -t: default timeout */
+ const char *opt_timeout = "5000"; /* -t: default timeout in msec */
/* We estimate rtt and wait rtt*4 before concluding that port is
* totally blocked. min rtt of 5 ms may be too low if you are
* scanning an Internet host behind saturated/traffic shaped link.
* Rule of thumb: with min_rtt of N msec, scanning 1000 ports
* will take N seconds at absolute minimum */
- const char *opt_min_rtt = "5"; /* -T: default min rtt */
+ const char *opt_min_rtt = "5"; /* -T: default min rtt in msec */
len_and_sockaddr *lsap;
int s;
unsigned port, max_port, nports;
@@ -57,10 +57,8 @@ int pscan_main(int argc, char **argv)
getopt32(argc, argv, "p:P:t:T:", &opt_min_port, &opt_max_port, &opt_timeout, &opt_min_rtt);
argv += optind;
max_port = xatou_range(opt_max_port, 1, 65535);
- port = xatou_range(opt_min_port, 1, 65535);
+ port = xatou_range(opt_min_port, 1, max_port);
nports = max_port - port + 1;
- if ((int)nports <= 0)
- bb_show_usage();
rtt_4 = timeout = xatou_range(opt_timeout, 1, INT_MAX/1000 / 4) * 1000;
min_rtt = xatou_range(opt_min_rtt, 1, INT_MAX/1000 / 4) * 1000;