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From: Guilhem Moulin <guilhem@debian.org>
Date: Mon, 22 Oct 2018 04:50:54 +0200
Subject: use -s/-p flags to specify listen address
---
nc.1 | 18 ++++++++++++++----
netcat.c | 49 +++++++++++++++++++++++++++++--------------------
2 files changed, 43 insertions(+), 24 deletions(-)
--- a/nc.1
+++ b/nc.1
@@ -143,8 +143,20 @@ multiple hosts.
.It Fl l
Listen for an incoming connection rather than initiating a
connection to a remote host.
-Cannot be used together with any of the options
-.Fl psxz .
+The
+.Ar destination
+and
+.Ar port
+to listen on can be specified either as non-optional arguments, or with
+options
+.Fl s
+and
+.Fl p
+respectively.
+Cannot be used together with
+.Fl x
+or
+.Fl z .
Additionally, any timeouts specified with the
.Fl w
option are ignored.
@@ -194,8 +206,6 @@ For
datagram sockets, specifies the local temporary socket file
to create and use so that datagrams can be received.
Cannot be used together with
-.Fl l
-or
.Fl x .
.It Fl T Ar keyword
Change the IPv4 TOS/IPv6 traffic class value.
--- a/netcat.c
+++ b/netcat.c
@@ -508,31 +508,40 @@ main(int argc, char *argv[])
# endif
/* Cruft to make sure options are clean, and used properly. */
- if (argv[0] && !argv[1] && family == AF_UNIX) {
-# if defined(IPPROTO_DCCP) && defined(SOCK_DCCP)
- if (dccpflag)
- errx(1, "cannot use -Z and -U");
-# endif
- host = argv[0];
- uport = NULL;
- } else if (!argv[0] && lflag) {
- if (sflag)
- errx(1, "cannot use -s and -l");
- if (pflag)
- errx(1, "cannot use -p and -l");
- if (zflag)
- errx(1, "cannot use -z and -l");
- } else if (argv[0] && !argv[1]) {
- if (!lflag)
- usage(1);
- uport = &argv[0];
- host = NULL;
- } else if (argv[0] && argv[1]) {
+ if (argc == 0 && lflag) {
+ uport = &pflag;
+ host = sflag;
+ } else if (argc == 1 && !pflag && !sflag) {
+ if (family == AF_UNIX) {
+ host = argv[0];
+ uport = NULL;
+ } else if (lflag) {
+ host = NULL;
+ uport = argv;
+ }
+ } else if (argc >= 2) {
+ if (lflag && (pflag || sflag || argc > 2))
+ usage(1); /* conflict */
host = argv[0];
uport = &argv[1];
} else
usage(1);
+ if (family == AF_UNIX) {
+# if defined(IPPROTO_DCCP) && defined(SOCK_DCCP)
+ if (dccpflag)
+ errx(1, "cannot use -Z and -U");
+# endif
+ if (uport && *uport)
+ errx(1, "cannot use port with -U");
+ if (!host)
+ errx(1, "missing socket pathname");
+ } else if (!uport || !*uport)
+ errx(1, "missing port number");
+
+ if (lflag && zflag)
+ errx(1, "cannot use -z and -l");
+
# if defined(TLS)
if (usetls) {
if (Cflag && unveil(Cflag, "r") == -1)
|
