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| | From: Aron Xu <aron@debian.org>
Date: Mon, 13 Feb 2012 19:06:52 +0800
Subject: broadcast support
---
nc.1 | 4 +++-
netcat.c | 22 ++++++++++++++++++++--
2 files changed, 23 insertions(+), 3 deletions(-)
--- a/nc.1
+++ b/nc.1
@@ -33,7 +33,7 @@
.Nd arbitrary TCP and UDP connections and listens
.Sh SYNOPSIS
.Nm nc
-.Op Fl 46CDdFhklNnrStUuvZz
+.Op Fl 46bCDdFhklNnrStUuvZz
.Op Fl I Ar length
.Op Fl i Ar interval
.Op Fl M Ar ttl
@@ -93,6 +93,8 @@ The options are as follows:
Use IPv4 addresses only.
.It Fl 6
Use IPv6 addresses only.
+.It Fl b
+Allow broadcast.
.It Fl C
Send CRLF as line-ending. Each line feed (LF) character from the input
data is translated into CR+LF before being written to the socket. Line
--- a/netcat.c
+++ b/netcat.c
@@ -132,6 +132,7 @@
#define UDP_SCAN_TIMEOUT 3 /* Seconds */
/* Command Line Options */
+int bflag; /* Allow Broadcast */
int dflag; /* detached, no stdin */
int Fflag; /* fdpass sock to stdout */
unsigned int iflag; /* Interval Flag */
@@ -263,9 +264,9 @@ main(int argc, char *argv[])
while ((ch = getopt(argc, argv,
# if defined(TLS)
- "46C:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:q:R:rSs:T:tUuV:vW:w:X:x:Z:z"))
+ "46bC:cDde:FH:hI:i:K:klM:m:NnO:o:P:p:q:R:rSs:T:tUuV:vW:w:X:x:Z:z"))
# else
- "46CDdFhI:i:klM:m:NnO:P:p:q:rSs:T:tUuV:vW:w:X:x:Zz"))
+ "46bCDdFhI:i:klM:m:NnO:P:p:q:rSs:T:tUuV:vW:w:X:x:Zz"))
# endif
!= -1) {
switch (ch) {
@@ -275,6 +276,13 @@ main(int argc, char *argv[])
case '6':
family = AF_INET6;
break;
+ case 'b':
+# if defined(SO_BROADCAST)
+ bflag = 1;
+# else
+ errx(1, "no broadcast frame support available");
+# endif
+ break;
case 'U':
family = AF_UNIX;
break;
@@ -1852,6 +1860,15 @@ set_common_sockopts(int s, int af)
{
int x = 1;
+# if defined(SO_BROADCAST)
+ if (bflag) {
+ /* allow datagram sockets to send packets to a broadcast address
+ * (this option has no effect on stream-oriented sockets) */
+ if (setsockopt(s, SOL_SOCKET, SO_BROADCAST,
+ &x, sizeof(x)) == -1)
+ err(1, NULL);
+ }
+# endif
# if defined(TCP_MD5SIG)
if (Sflag) {
if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG,
@@ -2127,6 +2144,7 @@ help(void)
fprintf(stderr, "\tCommand Summary:\n\
\t-4 Use IPv4\n\
\t-6 Use IPv6\n\
+ \t-b Allow broadcast\n\
\t-C Send CRLF as line-ending\n\
\t-D Enable the debug socket option\n\
\t-d Detach from stdin\n\
|