forgot svn add...
diff --git a/networking/pscan.c b/networking/pscan.c
new file mode 100644
index 0000000..10bf3b6
--- /dev/null
+++ b/networking/pscan.c
@@ -0,0 +1,150 @@
+/*
+ * Pscan is a mini port scanner implementation for busybox
+ *
+ * Copyright 2007 Tito Ragusa <farmatito@tiscali.it>
+ *
+ * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
+ */
+
+#include "libbb.h"
+
+/* debugging */
+#ifdef DEBUG_PSCAN
+#define DMSG(...) bb_error_msg(__VA_ARGS__)
+#define DERR(...) bb_perror_msg(__VA_ARGS__)
+#else
+#define DMSG(...) ((void)0)
+#define DERR(...) ((void)0)
+#endif
+
+/* return time in usec */
+// TODO: move to libbb and use in traceroute, zcip, arping etc
+// (maybe also use absolute monotonic clock - no time warps
+// due to admin resetting date/time?)
+static unsigned gettimeofday_us(void)
+{
+ struct timeval now;
+
+ if (gettimeofday(&now, NULL))
+ return 0;
+ return (now.tv_sec * 1000000 + now.tv_usec);
+}
+
+static const char *port_name(unsigned port)
+{
+ struct servent *server;
+
+ server = getservbyport(htons(port), NULL);
+ if (server)
+ return server->s_name;
+ return "unknown";
+}
+
+int pscan_main(int argc, char **argv);
+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 */
+ /* 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 */
+ len_and_sockaddr *lsap;
+ int s;
+ unsigned port, max_port, nports;
+ unsigned closed_ports = 0;
+ unsigned open_ports = 0;
+ /* all in usec */
+ unsigned timeout;
+ unsigned min_rtt;
+ unsigned rtt_4;
+ unsigned start;
+
+ opt_complementary = "=1"; /* exactly one non-option */
+ 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);
+ 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;
+
+ DMSG("min_rtt %u timeout %u", min_rtt, timeout);
+
+ lsap = xhost2sockaddr(*argv, port);
+ printf("Scanning %s ports %u to %u\n Port\tProto\tState\tService\n",
+ *argv, port, max_port);
+
+ for (; port <= max_port; port++) {
+ DMSG("rtt %u", rtt_4);
+
+ /* The SOCK_STREAM socket type is implemented on the TCP/IP protocol. */
+ set_nport(lsap, htons(port));
+ s = xsocket(lsap->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);
+ start = gettimeofday_us();
+ if (connect(s, &lsap->sa, lsap->len) == 0) {
+ /* Unlikely, for me even localhost fails :) */
+ DMSG("connect succeeded");
+ goto open;
+ }
+ /* Check for untypical errors... */
+ if (errno != EAGAIN && errno != EINPROGRESS
+ && errno != ECONNREFUSED
+ ) {
+ bb_perror_nomsg_and_die();
+ }
+
+ while (1) {
+ if (errno == ECONNREFUSED) {
+ DMSG("port %u: ECONNREFUSED", port);
+ closed_ports++;
+ break;
+ }
+ DERR("port %u errno %d @%u", port, errno, gettimeofday_us() - start);
+ if ((gettimeofday_us() - start) > rtt_4)
+ break;
+ /* Can sleep (much) longer than specified delay.
+ * We check rtt BEFORE we usleep, otherwise
+ * on localhost we'll do zero writes done (!)
+ * before we exceed (rather small) rtt */
+ usleep(rtt_4/8);
+ DMSG("write to port %u @%u", port, gettimeofday_us() - start);
+ if (write(s, " ", 1) >= 0) { /* We were able to write to the socket */
+ open:
+ open_ports++;
+ printf("%5u\ttcp\topen\t%s\n", port, port_name(port));
+ break;
+ }
+ }
+ DMSG("out of loop @%u", gettimeofday_us() - start);
+
+ /* 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)
+ * because we don't want to accidentally miss ports. */
+ rtt_4 = (gettimeofday_us() - start) * 4;
+ if (rtt_4 < min_rtt)
+ rtt_4 = min_rtt;
+ if (rtt_4 > timeout)
+ rtt_4 = timeout;
+ /* Clean up */
+ close(s);
+ }
+ if (ENABLE_FEATURE_CLEAN_UP) free(lsap);
+
+ printf("%d closed, %d open, %d timed out ports\n",
+ closed_ports,
+ open_ports,
+ nports - (closed_ports + open_ports));
+ return EXIT_SUCCESS;
+}