Let netcat support the use of service names instead of port numbers.

based on a diff from Andras Farkas <deepbluemistake@gmail.com>
ok deraadt@

2 files changed, 34 insertions, 18 deletions

diff --git a/src/usr.bin/nc/nc.1 b/src/usr.bin/nc/nc.1
index 6b14122f3d..ee57a64a6b 100644
--- a/src/usr.bin/nc/nc.1
+++ b/src/usr.bin/nc/nc.1
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: nc.1,v 1.71 2015/09/25 14:56:33 schwarze Exp $
+.\"     $OpenBSD: nc.1,v 1.72 2016/06/02 04:26:32 beck Exp $
 .\"
 .\" Copyright (c) 1996 David Sacerdote
 .\" All rights reserved.
@@ -25,7 +25,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: September 25 2015 $
+.Dd $Mdocdate: June 2 2016 $
 .Dt NC 1
 .Os
 .Sh NAME
@@ -337,8 +337,8 @@ sockets, a destination is required and is the socket path to connect to
 option is given).
 .Pp
 .Ar port
-can be a single integer or a range of ports.
-Ranges are in the form nn-mm.
+can be a specified as a numeric port number, or as a service name.
+Ports may be specified in a range of the form nn-mm.
 In general,
 a destination port must be specified,
 unless the
diff --git a/src/usr.bin/nc/netcat.c b/src/usr.bin/nc/netcat.c
index 95f276bc89..cf8a87d883 100644
--- a/src/usr.bin/nc/netcat.c
+++ b/src/usr.bin/nc/netcat.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: netcat.c,v 1.152 2016/05/28 20:14:58 beck Exp $ */
+/* $OpenBSD: netcat.c,v 1.153 2016/06/02 04:26:32 beck Exp $ */
 /*
  * Copyright (c) 2001 Eric Jackson <ericj@monkey.org>
  * Copyright (c) 2015 Bob Beck.  All rights reserved.
@@ -1283,6 +1283,27 @@ atelnet(int nfd, unsigned char *buf, unsigned int size)
         }
 }
 
+
+int
+strtoport(char *portstr, int udp)
+{
+        struct servent *entry;
+        const char *errstr;
+        char *proto;
+        int port = -1;
+
+        proto = udp ? "udp" : "tcp";
+
+        port = strtonum(portstr, 1, PORT_MAX, &errstr);
+        if (errstr == NULL)
+                return port;
+        if (errno != EINVAL)
+                errx(1, "port number %s: %s", errstr, portstr);
+        if ((entry = getservbyname(portstr, proto)) == NULL)
+                errx(1, "service \"%s\" unknown", portstr);
+        return ntohs(entry->s_port);
+}
+
 /*
  * build_ports()
  * Build an array of ports in portlist[], listing each port
@@ -1291,7 +1312,6 @@ atelnet(int nfd, unsigned char *buf, unsigned int size)
 void
 build_ports(char *p)
 {
-        const char *errstr;
         char *n;
         int hi, lo, cp;
         int x = 0;
@@ -1301,13 +1321,8 @@ build_ports(char *p)
                 n++;
 
                 /* Make sure the ports are in order: lowest->highest. */
-                hi = strtonum(n, 1, PORT_MAX, &errstr);
-                if (errstr)
-                        errx(1, "port number %s: %s", errstr, n);
-                lo = strtonum(p, 1, PORT_MAX, &errstr);
-                if (errstr)
-                        errx(1, "port number %s: %s", errstr, p);
-
+                hi = strtoport(n, uflag);
+                lo = strtoport(p, uflag);
                 if (lo > hi) {
                         cp = hi;
                         hi = lo;
@@ -1333,11 +1348,12 @@ build_ports(char *p)
                         }
                 }
         } else {
-                hi = strtonum(p, 1, PORT_MAX, &errstr);
-                if (errstr)
-                        errx(1, "port number %s: %s", errstr, p);
-                portlist[0] = strdup(p);
-                if (portlist[0] == NULL)
+                char *tmp;
+
+                hi = strtoport(p, uflag);
+                if (asprintf(&tmp, "%d", hi) != -1)
+                        portlist[0] = tmp;
+                else
                         err(1, NULL);
         }
 }