57 lines
1.2 KiB
Diff
57 lines
1.2 KiB
Diff
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From: Aron Xu <aron@debian.org>
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Date: Mon, 13 Feb 2012 15:29:37 +0800
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Subject: udp scan timeout
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---
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netcat.c | 23 +++++++++++++++--------
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1 file changed, 15 insertions(+), 8 deletions(-)
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--- a/netcat.c
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+++ b/netcat.c
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@@ -129,6 +129,8 @@
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#define CONNECTION_FAILED 1
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#define CONNECTION_TIMEOUT 2
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+#define UDP_SCAN_TIMEOUT 3 /* Seconds */
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+
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/* Command Line Options */
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int dflag; /* detached, no stdin */
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int Fflag; /* fdpass sock to stdout */
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@@ -822,7 +824,7 @@ main(int argc, char *argv[])
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continue;
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ret = 0;
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- if (vflag || zflag) {
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+ if (vflag) {
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/* For UDP, make sure we are connected. */
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if (uflag) {
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if (udptest(s) == -1) {
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@@ -1767,15 +1769,20 @@ build_ports(char *p)
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int
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udptest(int s)
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{
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- int i, ret;
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+ int i, t;
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- for (i = 0; i <= 3; i++) {
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- if (write(s, "X", 1) == 1)
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- ret = 1;
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- else
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- ret = -1;
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+ if ((write(s, "X", 1) != 1) ||
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+ ((write(s, "X", 1) != 1) && (errno == ECONNREFUSED)))
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+ return -1;
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+
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+ /* Give the remote host some time to reply. */
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+ for (i = 0, t = (timeout == -1) ? UDP_SCAN_TIMEOUT : (timeout / 1000);
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+ i < t; i++) {
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+ sleep(1);
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+ if ((write(s, "X", 1) != 1) && (errno == ECONNREFUSED))
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+ return -1;
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}
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- return ret;
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+ return 1;
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}
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void
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