TI-RPC is a user-space library of RPC functions that replaces ONC RPC
and allows RPC to operate in the new world of IPv6.
TI-RPC combines the concept of a transport protocol (UDP and TCP)
and a protocol family (PF_INET and PF_INET6) into a single identifier
called a "netid." For example, "udp" means UDP over IPv4, and "udp6"
means UDP over IPv6.
For rpcbind, then, the RPC service tuple that is registered and
advertised is:
[RPC program, RPC version, service address and port, netid]
instead of
[RPC program, RPC version, port, protocol]
Service address is typically ANYADDR, but can be a specific address
of one of the interfaces on a multi-homed host. The third item in
the new tuple is expressed as a universal address.
The current Linux rpcbind implementation registers a netid for both
protocol families when RPCB_SET is done for just the PF_INET6 version
of the netid (ie udp6 or tcp6). So registering "udp6" causes a
registration for "udp" to appear automatically as well.
We've recently determined that this is incorrect behavior. In the
TI-RPC world, "udp6" is not meant to imply that the registered RPC
service handles requests from AF_INET as well, even if the listener
socket does address mapping. "udp" and "udp6" are entirely separate
capabilities, and must be registered separately.
The Linux kernel, unlike TI-RPC, leverages address mapping to allow a
single listener socket to handle requests for both AF_INET and AF_INET6.
This is still OK, but the kernel currently assumes registering "udp6"
will cover "udp" as well. It registers only "udp6" for it's AF_INET6
services, even though they handle both AF_INET and AF_INET6 on the same
port.
So svc_register() actually needs to register both "udp" and "udp6"
explicitly (and likewise for TCP). Until rpcbind is fixed, the
kernel can ignore the return code for the second RPCB_SET call.
Please merge this with commit 15231312:
SUNRPC: Support IPv6 when registering kernel RPC services
Signed-off-by: Chuck Lever <[email protected]>
Cc: Olaf Kirch <[email protected]>
---
net/sunrpc/svc.c | 143 ++++++++++++++++++++++++++++++++++++++----------------
1 files changed, 100 insertions(+), 43 deletions(-)
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index c023cb3..5089014 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -721,69 +721,125 @@ 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.
+ * Register an "inet" protocol family netid with the local
+ * rpcbind daemon via an rpcbind v4 SET request.
*
- * 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.
+ * No netconfig infrastructure is available in the kernel, so
+ * we map IP_ protocol numbers to netids by hand.
*
- * 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.
+ * Returns zero on success; a negative errno value is returned
+ * if any error occurs.
*/
-static int __svc_register(const u32 program, const u32 version,
- const sa_family_t family,
- const unsigned short protocol,
- const unsigned short port)
+static int __svc_rpcb_register4(const u32 program, const u32 version,
+ 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),
};
+ char *netid;
+
+ switch (protocol) {
+ case IPPROTO_UDP:
+ netid = RPCBIND_NETID_UDP;
+ break;
+ case IPPROTO_TCP:
+ netid = RPCBIND_NETID_TCP;
+ break;
+ default:
+ return -EPROTONOSUPPORT;
+ }
+
+ return rpcb_v4_register(program, version,
+ (struct sockaddr *)&sin, netid);
+}
+
+/*
+ * Register an "inet6" protocol family netid with the local
+ * rpcbind daemon via an rpcbind v4 SET request.
+ *
+ * No netconfig infrastructure is available in the kernel, so
+ * we map IP_ protocol numbers to netids by hand.
+ *
+ * Returns zero on success; a negative errno value is returned
+ * if any error occurs.
+ */
+static int __svc_rpcb_register6(const u32 program, const u32 version,
+ const unsigned short protocol,
+ const unsigned short port)
+{
struct sockaddr_in6 sin6 = {
.sin6_family = AF_INET6,
.sin6_addr = IN6ADDR_ANY_INIT,
.sin6_port = htons(port),
};
- struct sockaddr *sap;
char *netid;
- switch (family) {
- case AF_INET:
- sap = (struct sockaddr *)&sin;
- netid = RPCBIND_NETID_TCP;
- if (protocol == IPPROTO_UDP)
- netid = RPCBIND_NETID_UDP;
+ switch (protocol) {
+ case IPPROTO_UDP:
+ netid = RPCBIND_NETID_UDP6;
break;
- case AF_INET6:
- sap = (struct sockaddr *)&sin6;
+ case IPPROTO_TCP:
netid = RPCBIND_NETID_TCP6;
- if (protocol == IPPROTO_UDP)
- netid = RPCBIND_NETID_UDP6;
break;
default:
- return -EAFNOSUPPORT;
+ return -EPROTONOSUPPORT;
+ }
+
+ return rpcb_v4_register(program, version,
+ (struct sockaddr *)&sin6, netid);
+}
+
+/*
+ * Register a kernel RPC service via rpcbind version 4.
+ *
+ * Returns zero on success; a negative errno value is returned
+ * if any error occurs.
+ */
+static int __svc_register(const u32 program, const u32 version,
+ const sa_family_t family,
+ const unsigned short protocol,
+ const unsigned short port)
+{
+ int error;
+
+ switch (family) {
+ case AF_INET:
+ return __svc_rpcb_register4(program, version,
+ protocol, port);
+ case AF_INET6:
+ error = __svc_rpcb_register6(program, version,
+ protocol, port);
+ if (error < 0)
+ return error;
+
+ /*
+ * Work around bug in some versions of Linux rpcbind
+ * which don't allow registration of both inet and
+ * inet6 netids.
+ *
+ * Error return ignored for now.
+ */
+ __svc_rpcb_register4(program, version,
+ protocol, port);
+ return 0;
}
- return rpcb_v4_register(program, version, sap, netid);
+ return -EAFNOSUPPORT;
}
-#else
+
+#else /* CONFIG_SUNRPC_REGISTER_V4 */
+
+/*
+ * Register a kernel RPC service via rpcbind version 2.
+ *
+ * Returns zero on success; a negative errno value is returned
+ * if any error occurs.
+ */
static int __svc_register(const u32 program, const u32 version,
sa_family_t family,
const unsigned short protocol,
@@ -794,7 +850,8 @@ static int __svc_register(const u32 program, const u32 version,
return rpcb_register(program, version, protocol, port);
}
-#endif
+
+#endif /* CONFIG_SUNRPC_REGISTER_V4 */
/**
* svc_register - register an RPC service with the local portmapper
@@ -818,12 +875,12 @@ int svc_register(const struct svc_serv *serv, const unsigned short proto,
if (progp->pg_vers[i] == NULL)
continue;
- dprintk("svc: svc_register(%s, %u, %s, %u, %d)%s\n",
+ dprintk("svc: svc_register(%sv%d, %s, %u, %u)%s\n",
progp->pg_name,
- serv->sv_family,
+ i,
proto == IPPROTO_UDP? "udp" : "tcp",
port,
- i,
+ serv->sv_family,
progp->pg_vers[i]->vs_hidden?
" (but not telling portmap)" : "");