In order to advertise NFS-related services on IPv6 interfaces via
rpcbind, the kernel RPC server implementation must use
rpcb_v4_register() instead of rpcb_register().
Legacy support (register using portmapper/rpcbindv2) is still available.
The new rpcbind version is not used unless enabled via a CONFIG option.
Signed-off-by: Chuck Lever <[email protected]>
---
net/sunrpc/svc.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 73 insertions(+), 0 deletions(-)
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index aa334c2..e22ef0d 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -720,6 +720,74 @@ svc_exit_thread(struct svc_rqst *rqstp)
}
EXPORT_SYMBOL(svc_exit_thread);
+#ifdef CONFIG_SUNRPC_REGISTER_V4
+/*
+ * Registering kernel RPC services with rpcbind version 2 will work
+ * over either IPv4 or IPv6, since the Linux kernel always registers
+ * services for the "any" address.
+ *
+ * However, the local rpcbind daemon listens on either only AF_INET
+ * or AF_INET6 (never both). When it listens on AF_INET6, an rpcbind
+ * version 2 registration will result in registering the service at
+ * IN6ADDR_ANY, even if the RPC service being registered is not
+ * IPv6-enabled.
+ *
+ * Rpcbind version 4 allows us to be a little more specific. Kernel
+ * RPC services that don't yet support AF_INET6 can register
+ * themselves as IPv4-only with the local rpcbind daemon, even if the
+ * daemon is listening only on AF_INET6.
+ *
+ * And, registering IPv6-enabled kernel RPC services via AF_INET6
+ * verifies that the local user space rpcbind daemon is properly
+ * configured to support remote AF_INET6 rpcbind requests.
+ *
+ * An AF_INET6 registration request will fail if the local rpcbind
+ * daemon is not set up to listen on AF_INET6. Likewise, we fail
+ * AF_INET6 registration requests if svc_register() is configured to
+ * support only rpcbind version 2.
+ */
+static int __svc_register(const u32 program, const u32 version,
+ const sa_family_t family,
+ const unsigned short protocol,
+ const unsigned short port)
+{
+ struct sockaddr_in sin = {
+ .sin_family = AF_INET,
+ .sin_addr.s_addr = htonl(INADDR_ANY),
+ .sin_port = htons(port),
+ };
+ struct sockaddr_in6 sin6 = {
+ .sin6_family = AF_INET6,
+ .sin6_addr = IN6ADDR_ANY_INIT,
+ .sin6_port = htons(port),
+ };
+ struct sockaddr *sap;
+ char *netid;
+ int error, result;
+
+ switch (family) {
+ case AF_INET:
+ sap = (struct sockaddr *)&sin;
+ netid = RPCBIND_NETID_TCP;
+ if (protocol == IPPROTO_UDP)
+ netid = RPCBIND_NETID_UDP;
+ break;
+ case AF_INET6:
+ sap = (struct sockaddr *)&sin6;
+ netid = RPCBIND_NETID_TCP6;
+ if (protocol == IPPROTO_UDP)
+ netid = RPCBIND_NETID_UDP6;
+ break;
+ default:
+ return -EAFNOSUPPORT;
+ }
+
+ error = rpcb_v4_register(program, version, sap, netid, &result);
+ if (!result)
+ error = -EACCES;
+ return error;
+}
+#else
static int __svc_register(const u32 program, const u32 version,
sa_family_t family,
const unsigned short protocol,
@@ -727,11 +795,15 @@ static int __svc_register(const u32 program, const u32 version,
{
int error, result;
+ if (family != AF_INET)
+ return -EAFNOSUPPORT;
+
error = rpcb_register(program, version, protocol, port, &result);
if (!result)
error = -EACCES;
return error;
}
+#endif
/**
* svc_register - register an RPC service with the local portmapper
@@ -739,6 +811,7 @@ static int __svc_register(const u32 program, const u32 version,
* @proto: transport protocol number to advertise
* @port: port to advertise
*
+ * Service is registered for any address in serv's address family
*/
int svc_register(const struct svc_serv *serv, const unsigned short proto,
const unsigned short port)