[PATCH 3/3] nfs-utils: add IPv6 support to nfsd

[Jeff Layton <jlayton@redhat.com>]

Add 2 new options to rpc.nfsd -- -4 and -6. -4 makes it an IPv4-only
server, and -6 makes it IPv6-only. Restructure the -H option so that
if the address appears to be or resolves to an IPv4 address, that
IPv6 is disabled. Ditto if it resolves to an IPv6 address.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
---
 utils/nfsd/nfsd.c |  137 +++++++++++++++++++++++++++++++++++++++++-----------
 1 files changed, 108 insertions(+), 29 deletions(-)

diff --git a/utils/nfsd/nfsd.c b/utils/nfsd/nfsd.c
index 25babe1..0022e65 100644
--- a/utils/nfsd/nfsd.c
+++ b/utils/nfsd/nfsd.c
@@ -41,7 +41,6 @@ static struct option longopts[] =
 };
 unsigned int protobits = NFSCTL_ALLBITS;
 unsigned int versbits = NFSCTL_ALLBITS;
-char *haddr = NULL;
 
 int
 main(int argc, char **argv)
@@ -49,7 +48,15 @@ main(int argc, char **argv)
 	int	count = 1, c, error, port, fd, found_one;
 	struct servent *ent;
 	struct hostent *hp;
-	struct sockaddr_in sin;
+	struct sockaddr_in sin = { };
+	struct sockaddr_in6 sin6 = { };
+	char	*haddr = NULL;
+	int	ipv4 = 1;
+#ifdef IPV6_SUPPORTED
+	int	ipv6 = 1;
+#else  /* IPV6_SUPPORTED */
+	int	ipv6 = 0;
+#endif /* IPV6_SUPPORTED */
 
 	ent = getservbyname ("nfs", "udp");
 	if (ent != NULL)
@@ -57,18 +64,12 @@ main(int argc, char **argv)
 	else
 		port = 2049;
 
-	while ((c = getopt_long(argc, argv, "H:hN:p:P:TU", longopts, NULL)) != EOF) {
+	while ((c = getopt_long(argc, argv, "H:hN:p:P:TU46", longopts, NULL)) != EOF) {
 		switch(c) {
 		case 'H':
-			if (inet_addr(optarg) != INADDR_NONE) {
-				haddr = strdup(optarg);
-			} else if ((hp = gethostbyname(optarg)) != NULL) {
-				haddr = inet_ntoa((*(struct in_addr*)(hp->h_addr_list[0])));
-			} else {
-				fprintf(stderr, "%s: Unknown hostname: %s\n",
-					argv[0], optarg);
-				usage(argv [0]);
-			}
+			/* we only deal with one host addr at the moment */
+			free(haddr);
+			haddr = strdup(optarg);
 			break;
 		case 'P':	/* XXX for nfs-server compatibility */
 		case 'p':
@@ -92,24 +93,76 @@ main(int argc, char **argv)
 			}
 			break;
 		case 'T':
-				NFSCTL_TCPUNSET(protobits);
-				break;
+			NFSCTL_TCPUNSET(protobits);
+			break;
 		case 'U':
-				NFSCTL_UDPUNSET(protobits);
-				break;
+			NFSCTL_UDPUNSET(protobits);
+			break;
+		case '4':
+			ipv6 = 0;
+			break;
+		case '6':
+			ipv4 = 0;
+			break;
 		default:
 			fprintf(stderr, "Invalid argument: '%c'\n", c);
 		case 'h':
 			usage(argv[0]);
 		}
 	}
-	/*
-	 * Do some sanity checking, if the ctlbits are set
-	 */
+
+	/* sanity checks */
+
+	/* if an address was specified, check it first */
+	if (haddr) {
+		/* does it look like an addr of some sort? */
+		if (inet_pton(AF_INET, haddr, &sin.sin_addr)) {
+			ipv6 = 0;
+			goto family_check;
+		} else if (inet_pton(AF_INET6, haddr, &sin6.sin6_addr)) {
+			ipv4 = 0;
+			goto family_check;
+		}
+
+		/* see if it's a hostname */
+		hp = gethostbyname(haddr);
+		if (!hp) {
+			fprintf(stderr, "%s: gethostbyname on %s failed: %d\n",
+					argv[0], haddr, h_errno);
+			error = h_errno;
+			usage(argv[0]);
+		}
+
+		if (hp->h_addrtype == AF_INET) {
+			ipv6 = 0;
+			memcpy(&sin.sin_addr, hp->h_addr_list[0],
+			       hp->h_length);
+			if (sin.sin_addr == INADDR_NONE) {
+				fprintf(stderr, "%s: Bad hostaddr %s\n",
+						argv[0], haddr);
+				usage(argv[0]);
+			}
+		} else if (hp->h_addrtype == AF_INET6) {
+			ipv4 = 0;
+			memcpy(&sin6.sin6_addr, hp->h_addr_list[0],
+			       hp->h_length);
+		}
+	}
+
+family_check:
+	/* make sure at least one address family is enabled */
+	if (!ipv4 && !ipv6) {
+		fprintf(stderr, "no address families enabled\n");
+		exit(1);
+	}
+
+	/* make sure at least one protocol type is enabled */
 	if (!NFSCTL_UDPISSET(protobits) && !NFSCTL_TCPISSET(protobits)) {
 		fprintf(stderr, "invalid protocol specified\n");
 		exit(1);
 	}
+
+	/* make sure that at least one version is enabled */
 	found_one = 0;
 	for (c = NFSD_MINVERS; c <= NFSD_MAXVERS; c++) {
 		if (NFSCTL_VERISSET(versbits, c))
@@ -120,14 +173,11 @@ main(int argc, char **argv)
 		exit(1);
 	}			
 
+	/* must have TCP for NFSv4 */
 	if (NFSCTL_VERISSET(versbits, 4) && !NFSCTL_TCPISSET(protobits)) {
 		fprintf(stderr, "version 4 requires the TCP protocol\n");
 		exit(1);
 	}
-	if (haddr == NULL) {
-		struct in_addr in = {INADDR_ANY}; 
-		haddr = strdup(inet_ntoa(in));
-	}
 
 	if (chdir(NFS_STATEDIR)) {
 		fprintf(stderr, "%s: chdir(%s) failed: %s\n",
@@ -142,6 +192,12 @@ main(int argc, char **argv)
 				"%s: invalid server count (%d), using 1\n",
 				argv[0], count);
 			count = 1;
+		} else if (count == 0) {
+			/*
+			 * don't bother setting anything else if the threads
+			 * are coming down anyway.
+			 */
+			goto set_threads;
 		}
 	}
 	/* KLUDGE ALERT:
@@ -157,28 +213,51 @@ main(int argc, char **argv)
 		(void) dup2(fd, 2);
 	}
 	closeall(3);
+	openlog("nfsd", LOG_PID, LOG_DAEMON);
 
-	sin.sin_family = AF_INET;
-	sin.sin_port = htons(port);
-	sin.sin_addr.s_addr = inet_addr(haddr);
+	/*
+	 * skip everything but setting of number of threads if sockets are
+	 * already open and in use.
+	 */
+	if (nfssvc_inuse())
+		goto set_threads;
 
 	/*
 	 * must set versions before the fd's so that the right versions get
 	 * registered with rpcbind. Note that on older kernels w/o the right
 	 * interfaces, these are a no-op.
 	 */
-	if (!nfssvc_inuse()) {
-		nfssvc_setvers(versbits);
+	nfssvc_setvers(versbits);
+
+	if (ipv4) {
+		sin.sin_family = AF_INET;
+		sin.sin_port = htons(port);
+		if (!haddr)
+			sin.sin_addr.s_addr = INADDR_ANY;
+
 		nfssvc_setfds(protobits, (struct sockaddr *) &sin, sizeof(sin));
 	}
 
-	openlog("nfsd", LOG_PID, LOG_DAEMON);
+	if (ipv6) {
+		sin6.sin6_family = AF_INET6;
+		sin6.sin6_port = htons(port);
+		if (!haddr)
+			sin6.sin6_addr = in6addr_any;
+
+		nfssvc_setfds(protobits, (struct sockaddr *) &sin6,
+				sizeof(sin6));
+	}
+
+set_threads:
 	if ((error = nfssvc_threads(port, count)) < 0) {
 		int e = errno;
 		syslog(LOG_ERR, "nfssvc: %s", strerror(e));
 		closelog();
 	}
 
+out:
+	free(haddr);
+	closelog();
 	return (error != 0);
 }
 
-- 
1.6.0.6