[RELENG_4] Re: [PATCH] Force mountd(8) to a specified port.

[Bruce M Simpson]

On Tue, Mar 02, 2004 at 09:10:30PM +0000, Bruce M Simpson wrote:
> As you are aware, RPC applications can be forced to listen on a known port
> through the sin/sa argument to bindresvport[_sa](). Why several Linux
> distributions have this feature yet none of the BSDs do is beyond me...

Here's a similar patch for RELENG_4. Please give me feedback.

Regards,
BMS
-------------- next part --------------
? .mountd.c.rej.swp
Index: mountd.8
===================================================================
RCS file: /home/ncvs/src/sbin/mountd/Attic/mountd.8,v
retrieving revision 1.16.2.2
diff -u -r1.16.2.2 mountd.8
--- mountd.8	8 Dec 2000 14:04:02 -0000	1.16.2.2
+++ mountd.8	2 Mar 2004 21:56:11 -0000
@@ -43,6 +43,7 @@
 .Sh SYNOPSIS
 .Nm
 .Op Fl 2dlnr
+.Op Fl p Ar port
 .Op Ar exportsfile
 .Sh DESCRIPTION
 .Nm Mountd
@@ -76,6 +77,18 @@
 that require it.
 It will automatically clear the vfs.nfs.nfs_privport sysctl flag, which
 controls if the kernel will accept NFS requests from reserved ports only.
+.It Fl p Ar port
+Force
+.Nm
+to bind to the specified port, for both
+.Vt AF_INET
+and
+.Vt AF_INET6
+address families.
+If
+.Nm
+cannot bind to this port, an appropriate error will be recorded in
+the system log, and the daemon will then exit.
 .It Fl r
 Allow mount RPCs requests for regular files to be served.
 Although this seems to violate the mount protocol specification,
Index: mountd.c
===================================================================
RCS file: /home/ncvs/src/sbin/mountd/Attic/mountd.c,v
retrieving revision 1.39.2.5
diff -u -r1.39.2.5 mountd.c
--- mountd.c	13 Sep 2002 15:57:43 -0000	1.39.2.5
+++ mountd.c	2 Mar 2004 21:56:11 -0000
@@ -238,8 +238,12 @@
 	int argc;
 	char **argv;
 {
+	struct sockaddr_in sin;
 	SVCXPRT *udptransp, *tcptransp;
+	char *endptr;
 	int c, error, mib[3];
+	int tcpsock, udpsock;
+	in_port_t svcport;
 	struct vfsconf vfc;
 
 	error = getvfsbyname("nfs", &vfc);
@@ -252,7 +256,7 @@
 	if (error)
 		errx(1, "NFS support is not available in the running kernel");
 
-	while ((c = getopt(argc, argv, "2dlnr")) != -1)
+	while ((c = getopt(argc, argv, "2dlnp:r")) != -1)
 		switch (c) {
 		case '2':
 			force_v2 = 1;
@@ -269,6 +273,14 @@
 		case 'l':
 			log = 1;
 			break;
+		case 'p':
+			endptr = NULL;
+			svcport = (in_port_t)strtoul(optarg, &endptr, 10);
+			if (endptr == NULL || *endptr != '\0' ||
+			    svcport < IPPORT_RESERVEDSTART ||
+			    svcport >= 65535)
+				usage();
+			break;
 		default:
 			usage();
 		};
@@ -313,8 +325,24 @@
 			exit(1);
 		}
 	}
-	if ((udptransp = svcudp_create(RPC_ANYSOCK)) == NULL ||
-	    (tcptransp = svctcp_create(RPC_ANYSOCK, 0, 0)) == NULL) {
+	if ((udpsock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1 ||
+	    (tcpsock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) {
+		syslog(LOG_ERR, "can't create socket");
+		exit(1);
+	}
+	if (svcport != 0) {
+		bzero(&sin, sizeof(struct sockaddr_in));
+		sin.sin_len = sizeof(struct sockaddr_in);
+		sin.sin_family = AF_INET;
+		sin.sin_port = htons(svcport);
+		if (bind(udpsock, (struct sockaddr *)&sin, sizeof(sin)) == -1 ||
+		    bind(tcpsock, (struct sockaddr *)&sin, sizeof(sin)) == -1) {
+			syslog(LOG_ERR, "can't bind socket");
+			exit(1);
+		}
+	}
+	if ((udptransp = svcudp_create(udpsock)) == NULL ||
+	    (tcptransp = svctcp_create(tcpsock, 0, 0)) == NULL) {
 		syslog(LOG_ERR, "can't create socket");
 		exit(1);
 	}
@@ -340,7 +368,8 @@
 usage()
 {
 	fprintf(stderr,
-		"usage: mountd [-2] [-d] [-l] [-n] [-r] [export_file]\n");
+		"usage: mountd [-2] [-d] [-l] [-n] [-p <port>] [-r] "
+		"[export_file]\n");
 	exit(1);
 }