*
* Copyright 2007 Tito Ragusa <farmatito@tiscali.it>
*
- * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
+//config:config PSCAN
+//config: bool "pscan (6 kb)"
+//config: default y
+//config: help
+//config: Simple network port scanner.
+
+//applet:IF_PSCAN(APPLET(pscan, BB_DIR_USR_BIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_PSCAN) += pscan.o
+
+//usage:#define pscan_trivial_usage
+//usage: "[-cb] [-p MIN_PORT] [-P MAX_PORT] [-t TIMEOUT] [-T MIN_RTT] HOST"
+//usage:#define pscan_full_usage "\n\n"
+//usage: "Scan a host, print all open ports\n"
+//usage: "\n -c Show closed ports too"
+//usage: "\n -b Show blocked ports too"
+//usage: "\n -p Scan from this port (default 1)"
+//usage: "\n -P Scan up to this port (default 1024)"
+//usage: "\n -t Timeout (default 5000 ms)"
+//usage: "\n -T Minimum rtt (default 5 ms, increase for congested hosts)"
#include "libbb.h"
#define MONOTONIC_US() ((unsigned)monotonic_us())
int pscan_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int pscan_main(int argc, char **argv)
+int pscan_main(int argc UNUSED_PARAM, char **argv)
{
const char *opt_max_port = "1024"; /* -P: default max port */
const char *opt_min_port = "1"; /* -p: default min port */
* 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 in msec */
+ const char *result_str;
len_and_sockaddr *lsap;
int s;
+ unsigned opt;
unsigned port, max_port, nports;
unsigned closed_ports = 0;
unsigned open_ports = 0;
unsigned timeout;
unsigned min_rtt;
unsigned rtt_4;
- unsigned start;
+ unsigned start, diff;
- opt_complementary = "=1"; /* exactly one non-option */
- getopt32(argv, "p:P:t:T:", &opt_min_port, &opt_max_port, &opt_timeout, &opt_min_rtt);
+ opt = getopt32(argv, "^"
+ "cbp:P:t:T:"
+ "\0" "=1", /* exactly one non-option */
+ &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, max_port);
nports = max_port - port + 1;
- 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;
+ timeout = xatou_range(opt_timeout, 1, INT_MAX/1000 / 4) * 1000;
+ /* Initial rtt is BIG: */
+ rtt_4 = timeout;
DMSG("min_rtt %u timeout %u", min_rtt, timeout);
DMSG("rtt %u", rtt_4);
/* The SOCK_STREAM socket type is implemented on the TCP/IP protocol. */
- set_nport(lsap, htons(port));
+ set_nport(&lsap->u.sa, htons(port));
s = xsocket(lsap->u.sa.sa_family, SOCK_STREAM, 0);
-
/* We need unblocking socket so we don't need to wait for ETIMEOUT. */
/* Nonblocking connect typically "fails" with errno == EINPROGRESS */
ndelay_on(s);
+
DMSG("connect to port %u", port);
+ result_str = NULL;
start = MONOTONIC_US();
if (connect(s, &lsap->u.sa, lsap->len) == 0) {
/* Unlikely, for me even localhost fails :) */
bb_perror_nomsg_and_die();
}
+ diff = 0;
while (1) {
if (errno == ECONNREFUSED) {
- DMSG("port %u: ECONNREFUSED", port);
+ if (opt & 1) /* -c: show closed too */
+ result_str = "closed";
closed_ports++;
break;
}
- DERR("port %u errno %d @%u", port, errno, MONOTONIC_US() - start);
- if ((MONOTONIC_US() - start) > rtt_4)
+ DERR("port %u errno %d @%u", port, errno, diff);
+
+ if (diff > rtt_4) {
+ if (opt & 2) /* -b: show blocked too */
+ result_str = "blocked";
break;
+ }
/* Can sleep (much) longer than specified delay.
* We check rtt BEFORE we usleep, otherwise
- * on localhost we'll do zero writes done (!)
+ * on localhost we'll have no writes done (!)
* before we exceed (rather small) rtt */
usleep(rtt_4/8);
- DMSG("write to port %u @%u", port, MONOTONIC_US() - start);
- if (write(s, " ", 1) >= 0) { /* We were able to write to the socket */
open:
+ diff = MONOTONIC_US() - start;
+ DMSG("write to port %u @%u", port, diff - start);
+ if (write(s, " ", 1) >= 0) { /* We were able to write to the socket */
open_ports++;
- printf("%5u\ttcp\topen\t%s\n", port, port_name(port));
+ result_str = "open";
break;
}
}
- DMSG("out of loop @%u", MONOTONIC_US() - start);
+ DMSG("out of loop @%u", diff);
+ if (result_str)
+ printf("%5u" "\t" "tcp" "\t" "%s" "\t" "%s" "\n",
+ port, result_str, port_name(port));
/* Estimate new rtt - we don't want to wait entire timeout
* for each port. *4 allows for rise in net delay.
- * We increase rtt quickly (*4), decrease slowly (4/8 == 1/2)
+ * We increase rtt quickly (rtt_4*4), decrease slowly
+ * (diff is at least rtt_4/8, *4 == rtt_4/2)
* because we don't want to accidentally miss ports. */
- rtt_4 = (MONOTONIC_US() - start) * 4;
+ rtt_4 = diff * 4;
if (rtt_4 < min_rtt)
rtt_4 = min_rtt;
if (rtt_4 > timeout)
}
if (ENABLE_FEATURE_CLEAN_UP) free(lsap);
- printf("%d closed, %d open, %d timed out ports\n",
+ printf("%u closed, %u open, %u timed out (or blocked) ports\n",
closed_ports,
open_ports,
nports - (closed_ports + open_ports));
projects / oweals / busybox.git / blobdiff