From 84e67ffa88e4d07b2e5848d666296a3e41750da6 Mon Sep 17 00:00:00 2001
From: cinap_lenrek <cinap_lenrek@felloff.net>
Date: Sun, 14 Jan 2018 19:32:13 +0100
Subject: [PATCH] listen(8): add -a option to restrict announce address,
 document tcp17019 and tcp17020

---
 sys/man/8/listen         | 23 ++++++++++++++++++-----
 sys/src/cmd/aux/listen.c | 29 +++++++++++++++++------------
 2 files changed, 35 insertions(+), 17 deletions(-)

diff --git a/sys/man/8/listen b/sys/man/8/listen
index cb1283d9c..617aac870 100644
--- a/sys/man/8/listen
+++ b/sys/man/8/listen
@@ -1,6 +1,6 @@
 .TH LISTEN 8
 .SH NAME
-listen, listen1, tcp7, tcp9, tcp19, tcp21, tcp23, tcp25, tcp53, tcp110, tcp113, tcp143, tcp445, tcp513, tcp515, tcp564, tcp565, tcp566, tcp567, tcp993, tcp995, tcp1723, tcp17007, tcp17008, tcp17009, tcp17010, tcp17013 \- listen for calls on a network device
+listen, listen1, tcp7, tcp9, tcp19, tcp21, tcp23, tcp25, tcp53, tcp110, tcp113, tcp143, tcp445, tcp513, tcp515, tcp564, tcp565, tcp566, tcp567, tcp993, tcp995, tcp1723, tcp17007, tcp17008, tcp17009, tcp17010, tcp17013, tcp17019, tcp17020 \- listen for calls on a network device
 .SH SYNOPSIS
 .B aux/listen
 .RB [ -iq ]
@@ -12,7 +12,9 @@ listen, listen1, tcp7, tcp9, tcp19, tcp21, tcp23, tcp25, tcp53, tcp110, tcp113,
 .IR namespace ]
 .RB [ -p
 .IR maxprocs ]
-.RI [ net ]
+.RB [ -a
+.IR addr ]
+.RI [ proto ]
 .PP
 .B aux/listen1
 [
@@ -28,11 +30,18 @@ listen, listen1, tcp7, tcp9, tcp19, tcp21, tcp23, tcp25, tcp53, tcp110, tcp113,
 .I args...
 ]
 .SH DESCRIPTION
-.I listen
+.I Listen
 listens on a network for inbound calls to local services.
-.I Net
+.I Proto
 is the network protocol on which to listen, by default
-.BR /net/tcp .
+.BR tcp .
+Incoming calls to any address
+.B *
+are accepted unless
+.I addr
+is specified with the
+.B -a
+option. 
 The services available are executable, non-empty files in
 .I srvdir
 or
@@ -145,6 +154,10 @@ and
 .IR cpu (1)
 using TLS for encryption. 
 .TP
+.B tcp17020
+TLS encrypted 9P fileserver (t9fs) for
+.IR srvtls (4)
+.TP
 .B tcp7
 echo any bytes received (bit mirror)
 .TP
diff --git a/sys/src/cmd/aux/listen.c b/sys/src/cmd/aux/listen.c
index 5c5b51fcd..0114f949d 100644
--- a/sys/src/cmd/aux/listen.c
+++ b/sys/src/cmd/aux/listen.c
@@ -28,9 +28,9 @@ void	newcall(int, char*, char*, Service*);
 int 	findserv(char*, char*, Service*, char*);
 int	getserv(char*, char*, Service*);
 void	error(char*);
-void	scandir(char*, char*, char*);
+void	scandir(char*, char*, char*, char*);
 void	becomenone(void);
-void	listendir(char*, char*, int);
+void	listendir(char*, char*, char*, int);
 
 char	listenlog[] = "listen";
 
@@ -40,6 +40,7 @@ int	quiet;
 int	immutable;
 char	*cpu;
 char	*proto;
+char	*addr;
 Announce *announcements;
 #define SEC 1000
 
@@ -48,8 +49,8 @@ char *namespace;
 void
 usage(void)
 {
-	error("usage: aux/listen [-q] [-n namespace] [-d servdir] [-t trustdir] [-p maxprocs]"
-		" [proto]");
+	error("usage: aux/listen [-iq] [-d srvdir] [-t trustsrvdir] [-n namespace] [-p maxprocs]"
+		" [-a addr] [proto]");
 }
 
 /*
@@ -85,6 +86,7 @@ main(int argc, char *argv[])
 	char *trustdir;
 	char *servdir;
 
+	addr = "*";
 	servdir = 0;
 	trustdir = 0;
 	proto = "tcp";
@@ -97,6 +99,9 @@ main(int argc, char *argv[])
 		error("can't get cputype");
 
 	ARGBEGIN{
+	case 'a':
+		addr = EARGF(usage());
+		break;
 	case 'd':
 		servdir = EARGF(usage());
 		break;
@@ -149,8 +154,8 @@ main(int argc, char *argv[])
 		proto = protodir;
 	else
 		proto++;
-	listendir(protodir, servdir, 0);
-	listendir(protodir, trustdir, 1);
+	listendir(protodir, addr, servdir, 0);
+	listendir(protodir, addr, trustdir, 1);
 
 	/* command returns */
 	exits(0);
@@ -165,7 +170,7 @@ dingdong(void*, char *msg)
 }
 
 void
-listendir(char *protodir, char *srvdir, int trusted)
+listendir(char *protodir, char *addr, char *srvdir, int trusted)
 {
 	int ctl, pid, start;
 	char dir[40], err[128], ds[128];
@@ -191,14 +196,14 @@ listendir(char *protodir, char *srvdir, int trusted)
 		return;
 	}
 
-	procsetname("%s %s %s", protodir, srvdir, namespace);
+	procsetname("%s %s %s %s", protodir, addr, srvdir, namespace);
 	if (!trusted)
 		becomenone();
 
 	notify(dingdong);
 
 	pid = getpid();
-	scandir(proto, protodir, srvdir);
+	scandir(proto, protodir, addr, srvdir);
 	for(;;){
 		/*
 		 * loop through announcements and process trusted services in
@@ -273,7 +278,7 @@ listendir(char *protodir, char *srvdir, int trusted)
 		}
 		if(!immutable){
 			alarm(0);
-			scandir(proto, protodir, srvdir);
+			scandir(proto, protodir, addr, srvdir);
 		}
 		start = 60 - (time(0)-start);
 		if(start > 0)
@@ -309,7 +314,7 @@ addannounce(char *str)
 }
 
 void
-scandir(char *proto, char *protodir, char *dname)
+scandir(char *proto, char *protodir, char *addr, char *dname)
 {
 	Announce *a, **l;
 	int fd, i, n, nlen;
@@ -334,7 +339,7 @@ scandir(char *proto, char *protodir, char *dname)
 				continue;
 			if(strncmp(nm, proto, nlen) != 0)
 				continue;
-			snprint(ds, sizeof ds, "%s!*!%s", protodir, nm + nlen);
+			snprint(ds, sizeof ds, "%s!%s!%s", protodir, addr, nm + nlen);
 			addannounce(ds);
 		}
 		free(db);