afs: Allow IPv6 address specification of VL servers

Allow VL server specifications to be given IPv6 addresses as well as IPv4
addresses, for example as:

	echo add foo.org 1111:2222:3333:0:4444:5555:6666:7777 >/proc/fs/afs/cells

Note that ':' is the expected separator for separating IPv4 addresses, but
if a ',' is detected or no '.' is detected in the string, the delimiter is
switched to ','.

This also works with DNS AFSDB or SRV record strings fetched by upcall from
userspace.

Signed-off-by: David Howells <dhowells@redhat.com>

fs/afs/cell.c

@@ -15,6 +15,7 @@
 #include <linux/ctype.h>
 #include <linux/dns_resolver.h>
 #include <linux/sched.h>
+#include <linux/inet.h>
 #include <keys/rxrpc-type.h>
 #include "internal.h"
 
@@ -86,28 +87,38 @@ static struct afs_cell *afs_cell_alloc(struct afs_net *net,
 		delimiter = ',';
 
 	} else {
+		if (strchr(vllist, ',') || !strchr(vllist, '.'))
+			delimiter = ',';
 		_vllist = vllist;
 	}
 
 	/* fill in the VL server list from the rest of the string */
 	do {
 		struct sockaddr_rxrpc *srx = &cell->vl_addrs[cell->vl_naddrs];
-		unsigned a, b, c, d;
+		const char *end;
 
 		next = strchr(_vllist, delimiter);
 		if (next)
 			*next++ = 0;
 
-		if (sscanf(_vllist, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
-			goto bad_address;
-
-		if (a > 255 || b > 255 || c > 255 || d > 255)
+		if (in4_pton(_vllist, -1, (u8 *)&srx->transport.sin6.sin6_addr.s6_addr32[3],
+			     -1, &end)) {
+			srx->transport_len		= sizeof(struct sockaddr_in6);
+			srx->transport.sin6.sin6_family	= AF_INET6;
+			srx->transport.sin6.sin6_flowinfo = 0;
+			srx->transport.sin6.sin6_scope_id = 0;
+			srx->transport.sin6.sin6_addr.s6_addr32[0] = 0;
+			srx->transport.sin6.sin6_addr.s6_addr32[1] = 0;
+			srx->transport.sin6.sin6_addr.s6_addr32[2] = htonl(0xffff);
+		} else if (in6_pton(_vllist, -1, srx->transport.sin6.sin6_addr.s6_addr,
+				    -1, &end)) {
+			srx->transport_len		= sizeof(struct sockaddr_in6);
+			srx->transport.sin6.sin6_family	= AF_INET6;
+			srx->transport.sin6.sin6_flowinfo = 0;
+			srx->transport.sin6.sin6_scope_id = 0;
+		} else {
 			goto bad_address;
-
-		srx->transport_len		= sizeof(struct sockaddr_in);
-		srx->transport.sin.sin_family	= AF_INET;
-		srx->transport.sin.sin_addr.s_addr =
-			htonl((a << 24) | (b << 16) | (c << 8) | d);
+		}
 
 	} while (cell->vl_naddrs++,
 		 cell->vl_naddrs < AFS_CELL_MAX_ADDRS && (_vllist = next));

fs/afs/proc.c

@@ -662,7 +662,7 @@ static int afs_proc_cell_servers_show(struct seq_file *m, void *v)
 
 	/* display one cell per line on subsequent lines */
 	sprintf(ipaddr, "%pISp", &server->addr.transport);
-	seq_printf(m, "%3d %-15.15s %5d\n",
+	seq_printf(m, "%3d %-15s %5d\n",
 		   atomic_read(&server->usage), ipaddr, server->fs_state);
 
 	return 0;

fs/afs/rxrpc.c

@@ -46,21 +46,20 @@ int afs_open_socket(struct afs_net *net)
 
 	_enter("");
 
-	ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET, &socket);
+	ret = sock_create_kern(&init_net, AF_RXRPC, SOCK_DGRAM, PF_INET6, &socket);
 	if (ret < 0)
 		goto error_1;
 
 	socket->sk->sk_allocation = GFP_NOFS;
 
 	/* bind the callback manager's address to make this a server socket */
+	memset(&srx, 0, sizeof(srx));
 	srx.srx_family			= AF_RXRPC;
 	srx.srx_service			= CM_SERVICE;
 	srx.transport_type		= SOCK_DGRAM;
-	srx.transport_len		= sizeof(srx.transport.sin);
-	srx.transport.sin.sin_family	= AF_INET;
-	srx.transport.sin.sin_port	= htons(AFS_CM_PORT);
-	memset(&srx.transport.sin.sin_addr, 0,
-	       sizeof(srx.transport.sin.sin_addr));
+	srx.transport_len		= sizeof(srx.transport.sin6);
+	srx.transport.sin6.sin6_family	= AF_INET6;
+	srx.transport.sin6.sin6_port	= htons(AFS_CM_PORT);
 
 	ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx));
 	if (ret < 0)

fs/afs/server.c

@@ -200,11 +200,6 @@ struct afs_server *afs_find_server(struct afs_net *net,
 
 	_enter("{%d,%pIS}", srx->transport.family, &srx->transport);
 
-	if (srx->transport.family != AF_INET) {
-		WARN(true, "AFS does not yes support non-IPv4 addresses\n");
-		return NULL;
-	}
-
 	read_lock(&net->servers_lock);
 
 	p = net->servers.rb_node;

fs/afs/vlclient.c

@@ -88,10 +88,15 @@ static int afs_deliver_vl_get_entry_by_xxx(struct afs_call *call)
 		entry->servers[loop].srx_family = AF_RXRPC;
 		entry->servers[loop].srx_service = FS_SERVICE;
 		entry->servers[loop].transport_type = SOCK_DGRAM;
-		entry->servers[loop].transport_len = sizeof(entry->servers[loop].transport.sin);
-		entry->servers[loop].transport.sin.sin_family = AF_INET;
-		entry->servers[loop].transport.sin.sin_port = htons(AFS_FS_PORT);
-		entry->servers[loop].transport.sin.sin_addr.s_addr = *bp++;
+		entry->servers[loop].transport_len = sizeof(entry->servers[loop].transport.sin6);
+		entry->servers[loop].transport.sin6.sin6_family = AF_INET6;
+		entry->servers[loop].transport.sin6.sin6_port = htons(AFS_FS_PORT);
+		entry->servers[loop].transport.sin6.sin6_flowinfo = 0;
+		entry->servers[loop].transport.sin6.sin6_scope_id = 0;
+		entry->servers[loop].transport.sin6.sin6_addr.s6_addr32[0] = 0;
+		entry->servers[loop].transport.sin6.sin6_addr.s6_addr32[1] = 0;
+		entry->servers[loop].transport.sin6.sin6_addr.s6_addr32[2] = htonl(0xffff);
+		entry->servers[loop].transport.sin6.sin6_addr.s6_addr32[3] = *bp++;
 	}
 
 	bp += 8; /* partition IDs */